WorldWideScience

Sample records for radiative control structures

  1. Active control of noise radiation from vibrating structures

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    developed, based on the theory of radiation filters for estimating the sound radiation from multimodal vibrations. This model has then been used in simulations of optimal feedback control, with special emphasis of the stability margins of the optimal control scheme. Two different methods of designing...... optimal and robust discrete-time feedback controllers for active vibration control of multimodal structures have been compared. They have been showed to yield controllers with identical frequency response characteristics, even though they employ completely different methods of numerical solutions...... and result in different representations of the controllers. The Internal Model Control structure combined with optimal filtering is suggested as an alternative to state space optimal control techniques for designing robust optimal controllers for audio frequency vibration control of resonant structures....

  2. Compact Radiative Control Structures for Millimeter Astronomy

    Science.gov (United States)

    Brown, Ari D.; Chuss, David T.; Chervenak, James A.; Henry, Ross M.; Moseley, s. Harvey; Wollack, Edward J.

    2010-01-01

    We have designed, fabricated, and tested compact radiative control structures, including antireflection coatings and resonant absorbers, for millimeter through submillimeter wave astronomy. The antireflection coatings consist of micromachined single crystal silicon dielectric sub-wavelength honeycombs. The effective dielectric constant of the structures is set by the honeycomb cell geometry. The resonant absorbers consist of pieces of solid single crystal silicon substrate and thin phosphorus implanted regions whose sheet resistance is tailored to maximize absorption by the structure. We present an implantation model that can be used to predict the ion energy and dose required for obtaining a target implant layer sheet resistance. A neutral density filter, a hybrid of a silicon dielectric honeycomb with an implanted region, has also been fabricated with this basic approach. These radiative control structures are scalable and compatible for use large focal plane detector arrays.

  3. Active structural acoustic control for reduction of radiated sound from structure

    International Nuclear Information System (INIS)

    Hong, Jin Seok; Oh, Jae Eung

    2001-01-01

    Active control of sound radiation from a vibrating rectangular plate by a steady-state harmonic point force disturbance is experimentally studied. Structural excitation is achieved by two piezoceramic actuators mounted on the panel. Two accelerometers are implemented as error sensors. Estimated radiated sound signals using vibro-acoustic path transfer function are used as error signals. The vibro-acoustic path transfer function represents system between accelerometers and microphones. The approach is based on a multi-channel filtered-x LMS algorithm. The results shows that attenuation of sound levels of 11dB, 10dB is achieved

  4. Flight controller design of unmanned airplane for radiation monitoring system via structured robust controller design using multiple model approach. Radiation monitoring flight in Namie-machi in Fukushima prefecture

    International Nuclear Information System (INIS)

    Sato, Masayuki; Muraoka, Koji; Hozumi, Koki; Sanada, Yukihisa; Yamada, Tsutomu; Torii, Tatsuo

    2015-01-01

    Due to the tragic accident of radioactive contaminant spread from Fukushima Dai-ichi nuclear power plant, the necessity of unmanned systems for radiation monitoring has been increasing. This paper concerns the flight controller design of an unmanned airplane which has been developed for radiation monitoring around the power plant. The flight controller consists of conventional control elements, i.e. Stability/Control Augmentation System (S/CAS) with PI controllers and guidance loops with PID controllers. The gains in these controllers are designed by minimizing appropriately defined cost functions for several possible models and disturbances to produce structured robust flight controllers. (This method is called as 'multiple model approach'.) Control performance of our flight controller was evaluated through flight tests and a primitive flight of radiation monitoring in Namie-machi in Fukushima prefecture was conducted in Jan. 2014. Flight results are included in this paper. (author)

  5. Frequency-independent radiation modes of interior sound radiation: Experimental study and global active control

    Science.gov (United States)

    Hesse, C.; Papantoni, V.; Algermissen, S.; Monner, H. P.

    2017-08-01

    Active control of structural sound radiation is a promising technique to overcome the poor passive acoustic isolation performance of lightweight structures in the low-frequency region. Active structural acoustic control commonly aims at the suppression of the far-field radiated sound power. This paper is concerned with the active control of sound radiation into acoustic enclosures. Experimental results of a coupled rectangular plate-fluid system under stochastic excitation are presented. The amplitudes of the frequency-independent interior radiation modes are determined in real-time using a set of structural vibration sensors, for the purpose of estimating their contribution to the acoustic potential energy in the enclosure. This approach is validated by acoustic measurements inside the cavity. Utilizing a feedback control approach, a broadband reduction of the global acoustic response inside the enclosure is achieved.

  6. Spectral radiative property control method based on filling solution

    International Nuclear Information System (INIS)

    Jiao, Y.; Liu, L.H.; Hsu, P.-F.

    2014-01-01

    Controlling thermal radiation by tailoring spectral properties of microstructure is a promising method, can be applied in many industrial systems and have been widely researched recently. Among various property tailoring schemes, geometry design of microstructures is a commonly used method. However, the existing radiation property tailoring is limited by adjustability of processed microstructures. In other words, the spectral radiative properties of microscale structures are not possible to change after the gratings are fabricated. In this paper, we propose a method that adjusts the grating spectral properties by means of injecting filling solution, which could modify the thermal radiation in a fabricated microstructure. Therefore, this method overcomes the limitation mentioned above. Both mercury and water are adopted as the filling solution in this study. Aluminum and silver are selected as the grating materials to investigate the generality and limitation of this control method. The rigorous coupled-wave analysis is used to investigate the spectral radiative properties of these filling solution grating structures. A magnetic polaritons mechanism identification method is proposed based on LC circuit model principle. It is found that this control method could be used by different grating materials. Different filling solutions would enable the high absorption peak to move to longer or shorter wavelength band. The results show that the filling solution grating structures are promising for active control of spectral radiative properties. -- Highlights: • A filling solution grating structure is designed to adjust spectral radiative properties. • The mechanism of radiative property control is studied for engineering utilization. • Different grating materials are studied to find multi-functions for grating

  7. Radiation effect of gate controlled lateral PNP BJTs

    International Nuclear Information System (INIS)

    Xi Shanbin; Zhou Dong; Lu Wu; Ren Diyuan; Wen Lin; Sun Jing; Wang Zhikuan

    2012-01-01

    Design and fabricate a new test structure of bipolar device: the gate controlled later PNP bipolar transistor (GCLPNP BJT), then sealed it together with the normal lateral PNP bipolar transistor which is made under the same manufacture process. Then 60 Co-γ radiation effects and annealing behaviors of these two structures are investigated. The results show that the response about base current, collector current, access base current and normalized current gain of GCLPNP bipolar transistor are almost identical to the normal one. Radiation induced defects in the GCLPNP bipolar transistor is separated quantitatively. Studying on the quantitative change of radiation induced defects in the domestic gate controlled bipolar transistor should be a useful way to research the change of radiation induced charges of normal PNP bipolar transistor. (authors)

  8. Radiation control system

    International Nuclear Information System (INIS)

    Murao, Mitsuo.

    1985-01-01

    Purpose: To rapidly and suitably performing planning and designation by radiation-working control systems in the radiation controlled area of nuclear power plant. Method: Various informations regarding radiation exposure are arranged and actual exposure data are statistically stored, to thereby perform forecasting calculation for the radiation exposure upon workings in the plurality of working regions in the radiation controlled area. Based on the forecast values and the registered workers' exposure dose in the past workings are alocated successively such that the total exposure does upon conducting the workings is less than the limited value, to prepare working plans in the areas. Further, procedures for preparing a series of documents regarding the workings in the radiation area are automated to rapidly and properly provide the informations serving to the planning and designation for the radiation workings. As a result, the radiation managers' burnden can be mitigated and an efficient working management system can be provided, in view of the exposure management and personal management. (Kamimura, M.)

  9. Synchrotron radiation: a new perspectives for structure examinations

    International Nuclear Information System (INIS)

    Kadyrzhanov, K.K.; Kozhakhmetov, S.K.; Turkebaev, T.Eh.

    2001-01-01

    An important task of radiation material testing is manufacture of multifunctional, stable and cheap materials with designed properties. A materials successful operation in an extemal conditions (high temperatures and pressures, high radiation fluences and charged particles, and etc.) imply an joint decision of physical, chemical, mechanical and other problems. The decision of these problems includes at least examination for structural, phase content, oxidation stability, thermal stability, mechanical strength, thin-film-coverings controlled synthesis (both the passivating and the catalytic) compatible with main matrix, and etc. Synchrotron radiation sources application for these problems are highly perspective. Solution of a set of problems on structural examinations for a materials exposed to high radiation fluences and operating in extemal condition is planning with use of the DELSY third generation synchrotron radiation source constructing at the Joint Institute for Nuclear Research (Dubna). In the paper the principal parameters of the DELSY synchrotron radiation source are given

  10. Control of Polymer Nanostructure and Functionality via Radiation Grafting

    International Nuclear Information System (INIS)

    Palmese, G.R.

    2006-01-01

    Radiation grafting provides a useful means for controlling polymer structure and performance. Particularly, it is appropriate for combining materials with distinct thermodynamic characteristics chemically at interfaces. Therefore polymeric materials that generally will not mix - i.e hydrophilic and hydrophobic polymers - can be combined efficiently using radiation based methods. This is of particular importance when attempting to form polymer-polymer nanocomposites where the thermodynamic penalty associated with high specific interfacial surface area is very large. Generally, the combination at small scales of such distinct materials is appropriate when specific functionality is desired while maintaining structural performance characteristics. In such cases the hydrophilic polymer lends functional characteristics such as ionic conductivity, self-healing, and actuation, while the hydrophobic polymer component provides structural stability. In this communication a summary of our recent work concerning the use of radiation grafting for the synthesis of nanostructured functional materials is given. Examples to be discussed include toughing of polymeric systems, the synthesis polymeric and inorganic nanotubes, and the design of permeation selective membranes. These examples will be used to demonstrate the effectiveness of radiation grafting techniques for controlling polymer properties and small-scale structure

  11. Active structural acoustic control of noise transmission through double panel systems

    Science.gov (United States)

    Carneal, James P.; Fuller, Chris R.

    1995-04-01

    A preliminary parametric study of active control of sound transmission through double panel systems has been experimentally performed. The technique used is the active structural acoustic control (ASAC) approach where control inputs, in the form of piezoelectric actuators, were applied to the structure while the radiated pressure field was minimized. Results indicate the application of control inputs to the radiating panel resulted in greater transmission loss due to its direct effect on the nature of the structural-acoustic coupling between the radiating panel and the receiving chamber. Increased control performance was seen in a double panel system consisting of a stiffer radiating panel with a lower modal density. As expected, more effective control of a radiating panel excited on-resonance is achieved over one excited off-resonance. In general, the results validate the ASAC approach for double panel systems and demonstrate that it is possible to take advantage of double panel behavior to enhance control performance, although it is clear that further research must be done to understand the physics involved.

  12. Radiation damage of structural materials

    International Nuclear Information System (INIS)

    Koutsky, J.; Kocik, J.

    1994-01-01

    Maintaining the integrity of nuclear power plants (NPP) is critical in the prevention or control of severe accidents. This monograph deals with both basic groups of structural materials used in the design of light-water nuclear reactors, making the primary safety barriers of NPPs. Emphasis is placed on materials used in VVER-type nuclear reactors: Cr-Mo-V and Cr-Ni-Mo-V steel for reactor pressure vessels (RPV) and Zr-Nb alloys for fuel element cladding. The book is divided into seven main chapters, with the exception of the opening one and the chapter providing phenomenological background for the subject of radiation damage. Chapters 3-6 are devoted to RPV steels and chapters 7-9 to zirconium alloys, analyzing their radiation damage structure, changes of mechanical properties due to neutron irradiation as well as factors influencing the degree of their performance degradation. The recovery of damaged materials is also discussed. Considerable attention is paid to a comparison of VVER-type and western-type light-water materials

  13. Control measures in industrial and medical applications of radiation

    International Nuclear Information System (INIS)

    Akinloye, M. K.

    1999-01-01

    Radiation and radioactive substances are natural and permanent features of the environment; additionally the use of human made radiation is widespread. Sources of radiation are essential to modern health care, disposable medical supplies sterilized by intense radiation have been central to combating disease, radiology is a vital diagnostic tool and radiotherapy is commonly part of the treatment of malignancies. Nuclear techniques are in growing use in industry, agriculture, medicine and many fields of research, benefiting hundreds of millions of people and giving employment to millions of people in the related occupations, Irradiation is used around the world to preserve and reduce wastage and sterilization techniques have been used to eradicate disease carrying insects and pests. Industrial radiography is in routine use, for example to examine welds and detect cracks and help prevent the failure of engineered structures. It is also known that exposure to ionizing radiation can result to injuries that manifest themselves in the individual and his descendants. It is therefore imperative that the use of radiation sources be accompanied with the methods necessary for the prevention of the harmful effects of the radiation. These methods are referred to as control measures. Control measures that have been applied in establishments can be classified into physical control measures and administrative control measures. Physical control measures involve the technical aspects while administrative control measures augment physical measures. The guidelines and recommendations for the safe use of radiation and radioactive materials are provided through legislative and regulatory controls

  14. Radiation control standards and procedures

    Energy Technology Data Exchange (ETDEWEB)

    1956-12-14

    This manual contains the Radiation Control Standards'' and Radiation Control Procedures'' at Hanford Operations which have been established to provide the necessary control radiation exposures within Irradiation Processing Department. Provision is also made for including, in the form of Bulletins'', other radiological information of general interest to IPD personnel. The purpose of the standards is to establish firm radiological limits within which the Irradiation Processing Department will operate, and to outline our radiation control program in sufficient detail to insure uniform and consistent application throughout all IPD facilities. Radiation Control Procedures are intended to prescribe the best method of accomplishing an objective within the limitations of the Radiation Control Standards. A procedure may be changed at any time provided the suggested changes is generally agreeable to management involved, and is consistent with department policies and the Radiation Control Standards.

  15. Development of methods to control radiation field and corrosion in PHWRS

    International Nuclear Information System (INIS)

    Velmurugan, S.

    2015-01-01

    Pressurized Heavy Water Reactors (PHWRs) is the mainstay of Indian Nuclear Power Program. There are 18 PHWRs (220 MWe and 540 MWe) in operation and 4 X 700 MWe PHWRs are under construction. In these reactors, as far as radiation field is concerned, the philosophy of ALARA (As Low As Reasonably Achievable) is followed. The primary coolant system chemistry control is given due consideration during operation so that corrosion of structural material is minimized which in turn controls the radiation field. Development and application of full system Dilute Chemical Decontamination (DCD) process helped to reduce the radiation field in MAPS-1 and 2, RAPS-1 and 2, NAPS-1 and 2 and KAPS-1. PHWR being a tube type reactor, it enables application of full system decontamination to its heavy water primary coolant system. Significant reduction in radiation field and consequent savings in MANREM could be achieved. Attempts are being made to understand the problem created by the release of antimony activities ( 122 Sb and 124 Sb) during chemical decontamination and during planned shutdown. Passivation as a method to control the radiation field and corrosion is being studied. Magnesium ion as a passivator to the ferrite filmed structural materials of PHWRs is being investigated. In addition, as PHWRs uses carbon steel as structural material, the use of passivation as a method to control flow accelerated corrosion (FAC) is also being studied. Magnesium ion gets incorporated in the ferrite film formed over carbon steel structural material and is expected to reduce the solubility of magnetite film thereby the FAC of feeders in PHWRs. (author)

  16. ALL-OPTICAL CONTROL OF THZ RADIATION IN PARALLEL PLATE WAVEGUIDES

    DEFF Research Database (Denmark)

    2010-01-01

    The invention relates to control of THz radiation in parallel plate waveguides (PPWG) by forming components in the waveguide by use of optical radiation pulses. Patterns of excited regions induced in the PPWG by an optical excitation pulses changes the electromagnetic properties of the waveguide...... medium in the THz regime, thereby forming transient passive and active components for controlling THz radiation signals. The excitation can be generation of free charge carriers in a semiconductor material in the PPWG, to create metallic regions that form mirrors, lenses or photonic crystal structures......-on-a-chip applications. The optical and THz radiation can be ultrashort pulses with picosecond or femtosecond pulse durations. L...

  17. Radiation hazard control report

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko; Hisanaga, Saemi; Miki, Ryota; Kawai, Hiroshi; Aoki, Yutaka; Sone, Koji; Okada, Hirokazu

    1990-01-01

    The report describes the radiation hazard control activities performed at the Atomic Energy Research Institute of Kinki University, Japan, during the one-year period from April 1989 to March 1990. Personal radiation hazard control is outlined first focusing on results of physical examination and data of personal exposure dose equivalent. Radiation control in laboratory is then described. Dose equivalent at various places is discussed on the basis of monthly total dose equivalent measured on film badges, measurements made by TLD, and observations made through a continuous radiations monitoring system. The concentration of radiations in air and water is discussed focusing on their measured concentrations in air at the air outlets of tracer/accelerator facilities, and radioactivity in waste water sampled in the reactor facilities and tracer/accelerator facilities. Another discussion is made on the surface contamination density over the floors, draft systems, sink surface, etc. Concerning outdoor radiation hazard control, furthermore, TLD measurements of environmental gamma-rays, data on total gamma-ray radioactivity in environmental samples, and analysis of gamma-ray emitting nuclides in environmental samples are described and discussed. (N.K.)

  18. The Influence of PZT Actuators Positioning in Active Structural Acoustic Control

    Directory of Open Access Journals (Sweden)

    P. Švec

    2007-01-01

    Full Text Available This paper deals with the effect of secondary actuator positioning in an active structural acoustics control (ASAC experiment. The ASAC approach is based on minimizing the sound radiation from structures to the far field by controlling the structural vibrations. In this article a rectangular steel plate structure was assumed with one secondary actuator attached to it. As a secondary actuator, a specially designed piezoelectric stripe actuator was used. We studied the effect of the position of the actuator on the pattern and on the radiated sound field of the structural vibration, with and without active control. The total radiated power was also measured. The experimental data was confronted with the results obtained by a numerical solution of the mathematical model used. For the solution, the finite element method in the ANSYS software package was used. 

  19. Radiation shielding structure for concrete structure

    International Nuclear Information System (INIS)

    Oya, Hiroshi

    1998-01-01

    Crack inducing members for inducing cracks in a predetermined manner are buried in a concrete structure. Namely, a crack-inducing member comprises integrally a shielding plate and extended plates situated at the center of a wall and inducing plates vertically disposed to the boundary portion between them with the inducing plates being disposed each in a direction perforating the wall. There are disposed integrally a pair of the inducing plate spaced at a predetermined horizontal distance on both sides of the shielding plate so as to form a substantially crank-shaped cross section and extended plates formed in the extending direction of the shielding plate, and the inducing plates are disposed each in a direction perforating the wall. Then, cracks generated when stresses are exerted can be controlled, and generation of cracks passing through the concrete structure can be prevented reliably. The reliability of a radiation shielding effect can be enhanced remarkably. (N.H.)

  20. Radiation Hazard control report

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko; Inagaki, Masayo; Miki, Ryota; Aoki, Yutaka; Takiguchi, Chizuko; Hutai, Yasuhiro; Sakamoto, Norihiko; Okazaki, Koji

    1992-01-01

    The results of radiation control for one year from April, 1991 to March, 1992 in the Atomic Energy Research Institute of Kinki University are reported. As for the persons engaging in radiation-related works as of April, 1991, 57 teachers in the Atomic Energy Research Institute and the Faculties of Science and Engineering, Pharmacology and Agriculture, 17 students of Department of Science and Engineering who utilize the reactor facility for graduation research, and 55 students of Department of Science and Engineering and others as the persons engaging in radiation-related works regarding the law on injury prevention, 129 persons in total became the object of radiation control. The state of operation of the nuclear reactor in fiscal year 1991 was the highest thermal output 1 W, the cumulative thermal output 362.62 Wh, and the total time of operation was 563.27 h. The operation of the neutron generator was carried out for 1.17 h because of the periodic inspection and the trial operation. In personal control, the abnormality due to radiation exposure was not found. The radiation control in laboratories and in fields are reported. (K.I.)

  1. Regulation on the organizatjon of radiation safety control bodies

    International Nuclear Information System (INIS)

    1975-01-01

    This is a basic document on matters of structure, organization, objectives, rights, and responsibilities of agencies enforcing compliance with radiation safety standards set up in Bulgaria. Under Public Health Law and Ministerial Council Decree No. 117, the organization and management of radiation safety in Bulgaria is entrusted to the Ministry of Public Health (MPH). Within its agency, the State Sanitary Control, authorities specialized in the area of radiation safety are as follows: the Radiation Hygiene Division (RHD) of the MPH Hygiene-and Epidemiology Bureau (HEB); the Specialized Radiation Safety Inspectorate of the Research Institute of Radiobiology and Radiation Hygiene (RIRRH); the Radiation Hygiene Sections of country HEBs; and State sanitary Inspectors assigned to large establishments in the country. (G.G.)

  2. Computerized radiation control system in the Chernobyl 30-km zone

    International Nuclear Information System (INIS)

    Vasil'chenko, D.L.; Pis'mak, A.D.; Livertovskij, G.P.; Chikhladze, V.S.

    1992-01-01

    Computerized radiation control system is intended for monitoring radiation in the zone of radiation-hazardous objects for providing nuclear power station services with current information on radiactive situation in the zone of observation and the doses of radiation taken by the personnel. Described are tasks and functions of the system, as well as its structure. It is noted that unique conditions of the Chernobyl' 30-km zone open up opportunities for experiments and testing new models of equipment. 2 figs

  3. Radiation Effects on Spacecraft Structural Materials

    International Nuclear Information System (INIS)

    Wang, Jy-An J.; Ellis, Ronald J.; Hunter, Hamilton T.; Singleterry, Robert C. Jr.

    2002-01-01

    Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

  4. Investigation of efficient termination structure for improved breakdown properties of semiconductor radiation detectors

    International Nuclear Information System (INIS)

    Krizaj, D.; Resnik, D.; Vrtacnik, D.; Amon, S.

    1998-01-01

    Efficiency of a new junction termination structure for improvement of breakdown properties of semiconductor radiation detectors is investigated. The structure consists of a diffused resistor winding around the active junction in a spiral fashion. The current flow through the spiral enables controlled potential distribution along the spiral turns and thus controlled depletion spreading from the main junction, efficiently preventing premature avalanche breakdown. Both multiple guard-ring structures and spiral junction termination structures have shown good breakdown properties typically three to five times higher than breakdown voltages of diodes without junction termination. The breakdown voltages of spiral junction termination structures are only weakly influenced by changes in substrate doping concentration caused by neutron irradiation. They can thus be considered for termination of future semiconductor radiation detectors

  5. Electromagnetic Radiation of Electrons in Periodic Structures

    CERN Document Server

    Potylitsyn, Alexander Petrovich

    2011-01-01

    Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...

  6. Radiation damage of structural materials

    CERN Document Server

    Koutsky, Jaroslav

    1994-01-01

    Maintaining the integrity of nuclear power plants is critical in the prevention or control of severe accidents. This monograph deals with both basic groups of structural materials used in the design of light-water nuclear reactors, making the primary safety barriers of NPPs. Emphasis is placed on materials used in VVER-type nuclear reactors: Cr-Mo-V and Cr-Ni-Mo-V steel for RPV and Zr-Nb alloys for fuel element cladding. The book is divided into 7 main chapters, with the exception of the opening one and the chapter providing a phenomenological background for the subject of radiation damage. Ch

  7. Radiation-resistant control system

    International Nuclear Information System (INIS)

    Cable, T.C.; Jones, S.

    1995-01-01

    REMOTEC has developed a open-quotes radiation resistanceclose quotes control system under a U.S. Department of Energy Small Business Innovative Research (SBIR) contract with assistance from the University of Florida. The SBIR goal was to develop a radiation resistant mobile robot from the ANDROS family of hazardous duty mobile robots that REMOTEC manufactures. See Refs. 1 and 2 for additional SBIR results. The control system, as well as the entire ANDROS robot, was redesigned, where necessary, to withstand radiation doses in excess of 10 6 rad. Those components of the robot that could not be purchased as open-quotes radiation hardenedclose quotes were tested under standard operating conditions for determination of their open-quotes radiation resistance.close quotes The entire ANDROS robot was then assembled with these new components and tested to > 10 6 rad

  8. Biofabricated Structures Reconstruct Functional Urinary Bladders in Radiation-injured Rat Bladders.

    Science.gov (United States)

    Imamura, Tetsuya; Shimamura, Mitsuru; Ogawa, Teruyuki; Minagawa, Tomonori; Nagai, Takashi; Silwal Gautam, Sudha; Ishizuka, Osamu

    2018-05-08

    The ability to repair damaged urinary bladders through the application of bone marrow-derived cells is in the earliest stages of development. We investigated the application of bone marrow-derived cells to repair radiation-injured bladders. We used a three-dimensional (3D) bioprinting robot system to biofabricate bone marrow-derived cell structures. We then determined if the biofabricated structures could restore the tissues and functions of radiation-injured bladders. The bladders of female 10-week-old Sprague-Dawley (SD) rats were irradiated with 2-Gy once a week for 5 weeks. Adherent and proliferating bone marrow-derived cells harvested from the femurs of male 17-week-old green fluorescence protein-transfected Tg-SD rats were cultured in collagen-coated flasks. Bone marrow-derived cell spheroids were formed in 96-well plates. Three layers of spheroids were assembled by the bioprinter onto a 9x9 microneedle array. The assembled spheroids were perfusion cultured for 7 days, and then the microneedle array was removed. Two weeks after the last radiation treatment, the biofabricated structures were transplanted into an incision on the anterior wall of the bladders (n=10). Control rats received the same surgery but without the biofabricated structures (sham-structure, n=12). At 2 and 4 weeks after surgery, the sham-structure control bladder tissues exhibited disorganized smooth muscle layers, decreased nerve cells, and significant fibrosis with increased presence of fibrosis-marker P4HB-positive cells and hypoxia-marker HIF1α-positive cells. The transplanted structures survived within the recipient tissues, and blood vessels extended within them from the recipient tissues. The bone marrow-derived cells in the structures differentiated into smooth muscle cells and formed smooth muscle clusters. The recipient tissues near the transplanted structures had distinct smooth muscle layers and reconstructed nerve cells, and only minimal fibrosis with decreased presence of P4

  9. Electromagnetic radiation of electrons in periodic structures

    International Nuclear Information System (INIS)

    Potylitsyn, Alexander Petrovich

    2011-01-01

    Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation and the Smith-Purcell effect. Characteristics of such radiation sources and perspectives of their usage are discussed. The recent experimental results as well as their interpretation are presented. (orig.)

  10. Magnetic tunnel structures: Transport properties controlled by bias, magnetic field, and microwave and optical radiation

    International Nuclear Information System (INIS)

    Volkov, N.V.; Eremin, E.V.; Tarasov, A.S.; Rautskii, M.V.; Varnakov, S.N.; Ovchinnikov, S.G.; Patrin, G.S.

    2012-01-01

    Different phenomena that give rise to a spin-polarized current in some systems with magnetic tunnel junctions are considered. In a manganite-based magnetic tunnel structure in CIP geometry, the effect of current-channel switching was observed, which causes bias-driven magnetoresistance, rf rectification, and the photoelectric effect. The second system under study, ferromagnetic/insulator/semiconductor, exhibits the features of the transport properties in CIP geometry that are also related to the current-channel switching effect. The described properties can be controlled by a bias, a magnetic field, and optical radiation. At last, the third system under consideration is a cooperative assembly of magnetic tunnel junctions. This system exhibits tunnel magnetoresistance and the magnetic-field-driven microwave detection effect.

  11. 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.

  12. Radiation shielding wall structure

    International Nuclear Information System (INIS)

    Nishimura, Yoshitaka; Oka, Shinji; Kan, Toshihiko; Misato, Takeshi.

    1990-01-01

    A space between a pair of vertical steel plates laterally disposed in parallel at an optional distance has a structure of a plurality of vertically extending tranks partitioned laterally by vertically placed steel plates. Then, cements are grouted to the tranks. Strip-like steel plates each having a thickness greater than the gap between the each of the vertically placed steel plates and the cement are bonded each at the surface for each of the vertically placed steel plates opposing to the cements. A protrusion of a strip width having radiation shielding performance substantially identical with that by the thickness of the cement is disposed in the strip-like steel plates. With such a constitution, a safety radiation shielding wall structure with no worry of radiation intrusion to gaps, if formed, between the steel plates and the grouted cements due to shrinkage of the cements. (I.N.)

  13. Radiation control in the nondestructive inspection

    International Nuclear Information System (INIS)

    Kariya, Yukihiro

    1982-01-01

    In the early days of radiation nondestructive inspection about ten years ago, the loss of radiation sources and careless radiation exposure gave the impression of radiography inspection being immediately slipshod management. In this problem, the peculiar nature of the business in this field is involved. In Nondestructive Inspection Co., Ltd., besides the safety management of radioisotopes, the radiation exposure control of personnel in the regular inspection of nuclear power plants has become increasingly important. The following matters are described: radiation utilization in nondestructive inspection (X- and #betta#-ray radiography, #betta#-ray leak test on shield), radiation control problems in nondestructive inspection business (the peculiar aspects of the business, the analysis of the incidents related with nondestructive inspection), and the practice of radiation control in nondestructive inspection in Nondestructive Inspection Co., Ltd. (Mori, K.)

  14. Controlled platform for the radiation dose data measured in Radiation controlled area of KOMAC

    International Nuclear Information System (INIS)

    Park, Sung Kyun; Min, Yi Sub; Park, Jeong Min; Cho, Yong Sub

    2016-01-01

    Korea multi-purpose accelerator complex (KOMAC), the branch institute of Korea atomic energy research institute (KAERI), is a multi-user facility to provide a high-intensity proton beam with the energy from 20 MeV to the 100 MeV. This proton beam is accelerated via the proton linear accelerator that is comprised of a 50-keV injector, 3-MeV radio frequency quadrupole (RFQ), and 100-MeV drift tube linac (DTL). The KOMAC site is classified into General public area and Radiation controlled area, according to the dose rate of 0.25 μSv/h. The system for the data made in Radiation controlled area should have the database to save and the data in the database could be expressed on the monitor in the any form which user wants. The control platform to satisfy these conditions will be made on the basis of the Qt program and MYSQL program. The place with the maximum average values about the alpha and beta detected is the entrance of Radiation controlled area. However, their values are very small in comparison to the criteria to decide the contamination area in KOMAC. That is, KOMAC is safe from the radioactive contamination. The reason why the radiation dose value is twice the background value in Klystron gallery is the klystron to generate the radiation. However, actually the klystron gallery is controlled by the control room when the proton beam is accelerated

  15. Controlled platform for the radiation dose data measured in Radiation controlled area of KOMAC

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Kyun; Min, Yi Sub; Park, Jeong Min; Cho, Yong Sub [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Korea multi-purpose accelerator complex (KOMAC), the branch institute of Korea atomic energy research institute (KAERI), is a multi-user facility to provide a high-intensity proton beam with the energy from 20 MeV to the 100 MeV. This proton beam is accelerated via the proton linear accelerator that is comprised of a 50-keV injector, 3-MeV radio frequency quadrupole (RFQ), and 100-MeV drift tube linac (DTL). The KOMAC site is classified into General public area and Radiation controlled area, according to the dose rate of 0.25 μSv/h. The system for the data made in Radiation controlled area should have the database to save and the data in the database could be expressed on the monitor in the any form which user wants. The control platform to satisfy these conditions will be made on the basis of the Qt program and MYSQL program. The place with the maximum average values about the alpha and beta detected is the entrance of Radiation controlled area. However, their values are very small in comparison to the criteria to decide the contamination area in KOMAC. That is, KOMAC is safe from the radioactive contamination. The reason why the radiation dose value is twice the background value in Klystron gallery is the klystron to generate the radiation. However, actually the klystron gallery is controlled by the control room when the proton beam is accelerated.

  16. Radiation control on the CERN sites

    International Nuclear Information System (INIS)

    Tuyn, J.W.N.; Alberto, D.; Lamberet, C.; Roubaud, G.; Wolf, J.

    1998-01-01

    The Site Section of the Radiation Protection Group is in charge of general radiation protection activities related to the two CERN sites. During 1997 these activities were: - stray radiation monitoring, - radioactive waste management, - storage of radioactive items, - radioactive source control, - radioactive transport, - control of non-ionizing radiation, - thermoluminescence dosimetry, - radioactivity measurements. A summary of these activities is presented in this part

  17. Radiation control on the CERN sites

    International Nuclear Information System (INIS)

    Hoefert, M.; Lamberet, C.; Otto, T.; Roubaud, G.; Wolf, J.

    1999-01-01

    The Site Section of the Radiation Protection Group is in charge of general radiation protection activities related to the two CERN sites. During 1998 these activities were: - stray radiation monitoring, - radioactive waste management, - storage of radioactive items, - radioactive source control, - radioactive transport, - control of non-ionizing radiation, - thermoluminescence dosimetry, - radioactivity measurements. A summary of the activities during 1998 is presented in this part

  18. Radiation Control Regulation 1993

    International Nuclear Information System (INIS)

    1993-01-01

    This Regulation (No. 434-1993) was made in pursuance of the Radiation Control Act 1990 and replaces the Active Substances Regulations 1959 repealed by the Act. It entered into force on 1 September 1993. The Regulation specifies that the technical radiation protection definitions have the same meaning as in the 1990 recommendations. The Regulation provides for the licensing of persons to use radioactive substances and radiation apparatus. It prescribes activities which may only be carried out by an accredited radiation expert and regulates the use of radiation apparatus and radioactive substances as well as the disposal and transport of radiation apparatus and radioactive substances. (NEA)

  19. State Radiation Protection Supervision and Control

    International Nuclear Information System (INIS)

    2003-01-01

    Radiation Protection Centre is carrying state supervision and control of radiation protection. The main objective of state supervision and control of radiation protection is assessing how licensees comply with requirements of the appropriate legislation and enforcement. Summary of inspections conducted in 2002 is presented

  20. State Radiation Protection Supervision and Control

    CERN Document Server

    2002-01-01

    Radiation Protection Centre is carrying state supervision and control of radiation protection. The main objective of state supervision and control of radiation protection is assessing how licensees comply with requirements of the appropriate legislation and enforcement. Summary of inspections conducted in 2002 is presented.

  1. Boiling water reactor radiation shielded Control Rod Drive Housing Supports

    Energy Technology Data Exchange (ETDEWEB)

    Baversten, B.; Linden, M.J. [ABB Combustion Engineering Nuclear Operations, Windsor, CT (United States)

    1995-03-01

    The Control Rod Drive (CRD) mechanisms are located in the area below the reactor vessel in a Boiling Water Reactor (BWR). Specifically, these CRDs are located between the bottom of the reactor vessel and above an interlocking structure of steel bars and rods, herein identified as CRD Housing Supports. The CRD Housing Supports are designed to limit the travel of a Control Rod and Control Rod Drive in the event that the CRD vessel attachement went to fail, allowing the CRD to be ejected from the vessel. By limiting the travel of the ejected CRD, the supports prevent a nuclear overpower excursion that could occur as a result of the ejected CRD. The Housing Support structure must be disassembled in order to remove CRDs for replacement or maintenance. The disassembly task can require a significant amount of outage time and personnel radiation exposure dependent on the number and location of the CRDs to be changed out. This paper presents a way to minimize personal radiation exposure through the re-design of the Housing Support structure. The following paragraphs also delineate a method of avoiding the awkward, manual, handling of the structure under the reactor vessel during a CRD change out.

  2. Analytical investigation of adaptive control of radiated inlet noise from turbofan engines

    Science.gov (United States)

    Risi, John D.; Burdisso, Ricardo A.

    1994-01-01

    An analytical model has been developed to predict the resulting far field radiation from a turbofan engine inlet. A feedforward control algorithm was simulated to predict the controlled far field radiation from the destructive combination of fan noise and secondary control sources. Numerical results were developed for two system configurations, with the resulting controlled far field radiation patterns showing varying degrees of attenuation and spillover. With one axial station of twelve control sources and error sensors with equal relative angular positions, nearly global attenuation is achieved. Shifting the angular position of one error sensor resulted in an increase of spillover to the extreme sidelines. The complex control inputs for each configuration was investigated to identify the structure of the wave pattern created by the control sources, giving an indication of performance of the system configuration. It is deduced that the locations of the error sensors and the control source configuration are equally critical to the operation of the active noise control system.

  3. Radiation measurements and quality control

    International Nuclear Information System (INIS)

    McLaughlin, W.L.

    1977-01-01

    Accurate measurements are essential to research leading to a successful radiation process and to the commissioning of the process and the facility. On the other hand, once the process is in production, the importance to quality control of measuring radiation quantities (i.e., absorbed dose, dose rate, dose distribution) rather than various other parameters of the process (i.e. conveyor speed, dwell time, radiation field characteristics, product dimensions) is not clearly established. When the safety of the product is determined by the magnitude of the administered dose, as in radiation sterilization, waste control, or food preservation, accuracy and precision of the measurement of the effective dose are vital. Since physical dose measurements are usually simpler, more reliable and reproducible than biological testing of the product, there is a trend toward using standardized dosimetry for quality control of some processes. In many industrial products, however, such as vulcanized rubber, textiles, plastics, coatings, films, wire and cable, the effective dose can be controlled satisfactorily by controlling process variables or by product testing itself. In the measurement of radiation dose profiles by dosimetry, it is necessary to have suitable dose meter calibrations, to account for sources of error and imprecision, and to use correct statistical procedures in specifying dwell times or conveyor speeds and source and product parameters to achieve minimum and maximum doses within specifications. (author)

  4. Networked solutions of radiation control of state borders and urban areas

    International Nuclear Information System (INIS)

    Kulik, Victor; Gordeev, Alexander; Mamedov, Arif

    2008-01-01

    Full text: Prevention of illicit trafficking in radioactive and nuclear materials through state borders as well as the disperse of radioactive materials in urban area is a challenging task of national security departments in many countries. To solve this task, appropriate actions of personnel on-site equipped by radiation detectors such as fixed radiation portal monitors or mobile personal radiation detectors are required. However, users of radiation equipment such as Customs, Border Guard and Police Services often perform radiation control as additional responsibility to their main duties. Furthermore, these users have no sufficient expertise in radiation control and need real-time remote expert help to interpret readings of radiation equipment and expert support in decision making process. Polimaster has developed complete solution called Nuclear Protection Network system (NPNET) for high-effective radiation control on State Borders as well as inside a country. NPNET system intended for efficient interaction and on-line data exchange between a user, radiation control instrument, for example a personal radiation detector or radioisotope identifier, and remote Command Center. Availability of such system allows to solve more efficiently tasks of detection, localization and identification of ionizing radiation sources, to properly interpret false alarms (e.g. at detention of a passenger having passed radio-therapy etc.) and effectively prevent illicit trafficking radioactive and nuclear materials. The NPNET system can cover territory as large as city or even a state and provides assistant of infinite number of independent user groups. NPNET has a module structure and could be easily adapted to any specific user's requirements. Thus, the radiation mobile system NPNET is an effective tool for prevention of illicit trafficking of nuclear and radioactive materials and is recommended for use by Border guards, Customs, Securities and emergency situations services. (author)

  5. An analytical and experimental investigation of active structural acoustic control of noise transmission through double panel systems

    Science.gov (United States)

    Carneal, James P.; Fuller, Chris R.

    2004-05-01

    An analytical and experimental investigation of active control of sound transmission through double panel systems has been performed. The technique used was active structural acoustic control (ASAC) where the control inputs, in the form of piezoelectric actuators, were applied to the structure while the radiating pressure field was minimized. Results verify earlier experimental investigations and indicate the application of control inputs to the radiating panel of the double panel system resulted in greater transmission loss (TL) due to its direct effect on the nature of the structural-acoustic (or radiation) coupling between the radiating panel and the receiving acoustic space. Increased control performance was seen in a double panel system consisting of a stiffer radiating panel due to its lower modal density and also as a result of better impedance matching between the piezoelectric actuator and the radiating plate. In general the results validate the ASAC approach for double panel systems, demonstrating that it is possible to take advantage of double panel system passive behavior to enhance control performance, and provide design guidelines.

  6. Radiation safety and control

    International Nuclear Information System (INIS)

    Kim, Jang Hee; Kim, Gi Sub.

    1996-12-01

    The principal objective of radiological safety control is intended for achievement and maintenance of appropriately safe condition in environmental control for activities involving exposure from the use of radiation. In order to establish these objective, we should be to prevent deterministic effects and to limit the occurrence stochastic effects to level deemed to be acceptable by the application of general principles of radiation protection and systems of dose limitation based on ICRP recommendations. (author). 22 tabs., 13 figs., 11 refs

  7. Radiation control report

    International Nuclear Information System (INIS)

    Inagaki, Masayo; Matsuda, Toshiro; Wakabayashi, Genichiro; Yamamoto, Tomosada; Takiguchi, Chizuko; Yamanishi, Hirokuni

    2015-01-01

    This paper reports the results of radiation control during April 2013 and April 2014 at the Atomic Energy Research Institute of Kinki University. The subjects of radiation control were totally 148 persons including teaching staff and students who engaged in radiation jobs at the Atomic Energy Research Institute, the Faculty of Science and Engineering, and the Faculty of Pharmacy. As for the operating conditions of the reactor, total operating time was 485.28 hours. Since new regulations came into force in accordance with the law revision in December 2013, this reactor became unable to operate since the regular inspection in February 2014, and the verification of compliance to the new regulatory standards has become necessary for the restart. In this paper, the following are described as the radiation management that was carried out on a regular basis in FY2013: (1) health diagnosis and individual exposure dose management, as personal management, (2) dose rate measurements in facilities and measurements of radioactive substance concentration in the air and water, as facility management, and (3) measurement data and analysis results of environmental γ-ray dose rate, total β radioactivity concentration in environmental samples, and γ-ray nuclide analysis of environmental samples, as field management. (A.O.)

  8. Optimization strategy for actuator and sensor placement in active structural acoustic control

    NARCIS (Netherlands)

    Oude nijhuis, M.H.H.; de Boer, Andries

    2003-01-01

    In active structural acoustic control the goal is to reduce the sound radiation of a structure by means of changing the vibrational behaviour of that structure. The performance of such an active control system is to a large extent determined by the locations of the actuators and sensors. In this

  9. Synchrotron radiation and structural proteomics

    CERN Document Server

    Pechkova, Eugenia

    2011-01-01

    This book presents an overview of the current state of research in both synchrotron radiation and structural proteomics from different laboratories worldwide. The book presents recent research results in the most advanced methods of synchrotron radiation analysis, protein micro- and nano crystallography, X-ray scattering and X-ray optics, coherent X-Ray diffraction, and laser cutting and contactless sample manipulation are described in details. The book focuses on biological applications and highlights important aspects such as radiation damage and molecular modeling.

  10. The records of radiation control division, No.22 (1985)

    International Nuclear Information System (INIS)

    Fukui, Masami; Katsurayama, Kousuke; Ishida, Masahiro

    1987-03-01

    This report is a summary of activities of the radiation control division on the safety management in FY 1985. This report describes the records of the radiation control based on the activities of Indoor Radiation Control Section, Field Radiation Control Section and Personnel Radiation Control Section. External radiation doses were monitored using survey meters and film badges in the working area. Radioactive concentrations in dust and air were monitored in the radiation controlled area and at a number of locations outside the KURRI facilities. Reports of routine tasks such as the meteorological records, and the control of human exposure to radiation are described. This report also summarizes number of unscheduled tasks performed, including the replacement of the centralized monitoring board for radiation control, radiation monitors related to the extension of the spent fuel storage building, and the computer processing system of some indoor radiation monitors. Measurements of environmental radioactivity at several field locations are also presented in this report. (author)

  11. National system of notification, authorization and inspection for the control of radiation sources in Ghana

    International Nuclear Information System (INIS)

    Schandorf, C.; Darko, E.O.; Yeboah, J.; Asiamah, S.D.

    2001-01-01

    The Radiation Protection Board (RPB) was established in 1993 in Ghana as the regulatory authority for radiation protection and safety of radiation sources; its functions are prescribed in the 1993 national radiation protection regulation. The report describes how the country's radiation protection and safety infrastructure have been established, including the RPB's organizational structure, with reference in particular to the main activities carried out by both the Regulatory Control Department and the Radiation and Waste Safety Department. It also briefly mentions the existing RPB human resources; the national system of notification, authorization and inspection of radiation sources; the inventory of radiation sources; and the management of disused radiation sources. Finally, the report identifies the two main problem areas regarding the regulatory control of radiation sources in the country. (author)

  12. Radiation control

    International Nuclear Information System (INIS)

    Uchida, Akira

    1981-01-01

    This paper describes on how the condition of radiation level in the ring (storage ring) experimentation room changes corresponding to the operating stage of SOR-ring (synchrotron radiation storage ring), and does not describe on the present radiation control in the SOR facility. The operating stage of SOR is divided into the following five: (1) 307 MeV electron injection, (2) 307 MeV electron storage (used for SOR experiments), (3) energy increase from 307 to 380 MeV, (4) 380 MeV electron storage, (5) re-injection and completion of operation. Gamma and X ray levels are shown when electron beam is injected from the electron synchrotron to the SOR-ring. Two main causes of the high level are reported. Spatial dose rate in storing 307 MeV electrons in also illustrated. This is sufficiently lower than that at electron incidence. The measurement of radiation level at the time of energy increase from 307 to 380 MeV has just started. Since the radiation level in 380 MeV storage, measured at the points about 20 cm apart from the electron orbit, showed several mR/h, the level seems to be negligible at the points where experiments are carried out, 1 m away from the measurement points. The radiation level in electron reinjection and completion of operation may be large during a short period (a few Roentgen) like the time of energy increase. Therefore, the beam shall be re-injected or decreased after confirming that all experimenters have retreated into the predetermined place. (Wakatsuki, Y.)

  13. Microwave-radiation-induced molecular structural rearrangement of hen egg-white lysozyme

    Science.gov (United States)

    Singh, Anang K.; Burada, P. S.; Bhattacharya, Susmita; Bag, Sudipta; Bhattacharya, Amitabha; Dasgupta, Swagata; Roy, Anushree

    2018-05-01

    We have investigated the nonthermal effect of 10 GHz/22 dBm microwave radiation on hen egg-white lysozyme (HEWL) over different irradiation times, ranging from 2 min to 1 h. To ensure a control over the radiation parameters, a pair of microwave rectangular waveguides is used to irradiate the samples. Optical spectroscopic measurements, which include UV-visible absorption spectroscopy, Raman spectroscopy, and far UV CD spectroscopy, reveal the exposure of the buried tryptophan (Trp) residues of the native molecule between 15 and 30 min of radiation. The higher duration of the perturbation leads to a compact structure of the protein and Trp residues are buried again. Interestingly, we do not find any change in the secondary structure of the protein even for 1 h duration of radiation. The relaxation dynamics of the irradiated molecules also has been discussed. We have shown that the molecules relax to their native configuration in 7-8 h after the radiation field is turned off. The structural rearrangement over the above timescale has further been probed by a model calculation, based on a modified Langevin equation. Our coarse-grained simulation approach utilizes the mean of atomic positions and net atomic charge of each amino acid of native HEWL to mimic the initial conformation of the molecule. The modified positions of the residues are then calculated for the given force fields. The simulation results reveal the nonmonotonous change in overall size of the molecule, as observed experimentally. The radiation parameters used in our experiments are very similar to those of some of the electronic devices we often come across. Thus, we believe that the results of our studies on a simple protein structure may help us in understanding the effect of radiation on complex biological systems as well.

  14. The effects and control of radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1982-12-01

    The subject is discussed under the headings: introduction; ionising radiation (alpha and beta particles, gamma- and X-radiation, neutrons, half-life, sources of radiation); biological effects; risk estimates (somatic) (early effects, delayed effects); risk estimates (hereditary); control of radiation; risk estimates (accidents). (U.K.)

  15. State Supervision and Control of Radiation Protection

    CERN Document Server

    2001-01-01

    Radiation Protection Centre is carrying state supervision and control of radiation protection. The main objective of state supervision and control of radiation protection is assessing how licensees comply with requirements of the appropriate legislation and enforcement. Summary of inspections conducted in 1999-2001 is presented.

  16. A new radiation safety control system for Ganil

    International Nuclear Information System (INIS)

    Saint Jores, P. De; Luong, T.T.; Martina, L.; Vega, G.

    1991-01-01

    A second generation radiation safety control system has been installed to upgrade the initial system which was not flexible enough to support new ion beams and new experimental conditions required by the accelerator operation. The main reasons which necessitated the improvement of the safety control system are presented. The new system which controls the Ganil accelerator from the first quarter of 1990 is described. It uses a star structured architecture, VME standard processors and front-end modules activated by pDOS operating system and high level language (C and Fortran) tasks, associated with enhanced resolution color displays for real time synoptics. (R.P.) 4 refs., 4 figs

  17. Federal/State Radiation Control Legislation, 1974

    International Nuclear Information System (INIS)

    Miller, L.A.

    1975-07-01

    A review is presented of Federal and State radiation control legislation for calendar year 1974, in Federal-State, subject, and status order. A brief description of each bill introduced in 1974 is included, plus existing laws or statutes governing radiation control. (auth)

  18. Online Simulation of Radiation Track Structure Project

    Science.gov (United States)

    Plante, Ianik

    2015-01-01

    Space radiation comprises protons, helium and high charged and energy (HZE) particles. High-energy particles are a concern for human space flight, because they are no known options for shielding astronauts from them. When these ions interact with matter, they damage molecules and create radiolytic species. The pattern of energy deposition and positions of the radiolytic species, called radiation track structure, is highly dependent on the charge and energy of the ion. The radiolytic species damage biological molecules, which may lead to several long-term health effects such as cancer. Because of the importance of heavy ions, the radiation community is very interested in the interaction of HZE particles with DNA, notably with regards to the track structure. A desktop program named RITRACKS was developed to simulate radiation track structure. The goal of this project is to create a web interface to allow registered internal users to use RITRACKS remotely.

  19. Direction selective structural-acoustic coupled radiator

    Science.gov (United States)

    Seo, Hee-Seon; Kim, Yang-Hann

    2005-04-01

    This paper presents a method of designing a structural-acoustic coupled radiator that can emit sound in the desired direction. The structural-acoustic coupled system is consisted of acoustic spaces and wall. The wall composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. An equation is developed that predicts energy distribution and energy flow in the two spaces separated by the wall, and its computational examples are presented including near field acoustic characteristics. To design the directional coupled radiator, Pareto optimization method is adapted. An objective is selected to maximize radiation power on a main axis and minimize a side lobe level and a subjective is selected direction of the main axis and dimensions of the walls geometry. Pressure and intensity distribution of the designed radiator is also presented.

  20. The increased use of radiation requires enhanced activities regarding radiation safety control

    International Nuclear Information System (INIS)

    Lee, Yun Jong; Lee, Jin Woo; Jeong, Gyo Seong

    2015-01-01

    More recently, companies that have obtained permission to use radioactive materials or radiation device and registered radiation workers have increased by 10% and 4% respectively. The increased use of radiation could have an effect on radiation safety control. However, there is not nearly enough manpower and budget compared to the number of workers and facilities. This paper will suggest a counteroffer thought analyzing pending issues. The results of this paper indicate that there are 47 and 31.3 workers per radiation protection officer in educational and research institutes, respectively. There are 20.1 persons per RPO in hospitals, even though there are 2 RPOs appointed. Those with a special license as a radioisotope handler were ruled out as possible managers because medical doctors who have a special license for radioisotope handling normally have no experience with radiation safety. The number of staff members and budget have been insufficient for safety control at most educational and research institutes. It is necessary to build an optimized safety control system for effective Radiation Safety Control. This will reduce the risk factor of safety, and a few RPOs can be supplied for efficiency and convenience

  1. The increased use of radiation requires enhanced activities regarding radiation safety control

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Jong; Lee, Jin Woo; Jeong, Gyo Seong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2015-05-15

    More recently, companies that have obtained permission to use radioactive materials or radiation device and registered radiation workers have increased by 10% and 4% respectively. The increased use of radiation could have an effect on radiation safety control. However, there is not nearly enough manpower and budget compared to the number of workers and facilities. This paper will suggest a counteroffer thought analyzing pending issues. The results of this paper indicate that there are 47 and 31.3 workers per radiation protection officer in educational and research institutes, respectively. There are 20.1 persons per RPO in hospitals, even though there are 2 RPOs appointed. Those with a special license as a radioisotope handler were ruled out as possible managers because medical doctors who have a special license for radioisotope handling normally have no experience with radiation safety. The number of staff members and budget have been insufficient for safety control at most educational and research institutes. It is necessary to build an optimized safety control system for effective Radiation Safety Control. This will reduce the risk factor of safety, and a few RPOs can be supplied for efficiency and convenience.

  2. Automatization of the radiation control measurements

    International Nuclear Information System (INIS)

    Seki, Akio; Ogata, Harumi; Horikoshi, Yoshinori; Shirai, Kenji

    1988-01-01

    Plutonium Fuel Production Facility (PFPF) was constructed to fabricate the MOX fuels for 'MONJU' and 'JOYO' reactors and to develop the practical fuel fabricating technology. For the fuel fabrication process in this facility, centralized controlling system is being adopted for the mass production of the fuel and reduction of the radiation exposure dose. Also, the radiation control systems are suitable for the large-scale facility and the automatic-remote process of the fuel fabrication. One of the typical radiation control systems is the self moving survey system which has been developed by PNC and adopted for the automatic routine monitoring. (author)

  3. Investigation the structural and functional changes of heart in elderly soldiers who was working with radiation producing equipments

    International Nuclear Information System (INIS)

    Li Jiahua; Li Li; Cao Hongliu; Wang Quanhong; Huang Fang

    2010-01-01

    Objective: To investigate the structural and functional changes of heart in elderly soldiers who was working with radiation producing equipments. The involvement of cardiovascular system in radiation and its intensity was investigated in this study. Methods: Fifty elderly males (>60 years old) who were exposed to radiation producing equipments (exposure group) and 50 elderly (>60 years old) retired male commanders without radiation exposure history (control group) were enrolled in this study. Echocardiographic evaluation of cardiac structure and function was conducted with Siemens Sonline G60 ultrasound system. 12-lead electrocardiogram (ECG) and routine physical examination had also been done in both groups. Results: Ejection fraction, minor axis reduced rate had no distinct difference between exposure group and control group (t=1.52 and t=1.68, P>0.05). Cardiac output, cardiac stroke volume, stroke index, ventricular diastolic flow velocity E/A ratios in exposure group were lower than control group (t=11.81, t=7.11 and t=7.88, P 2 =9.72, and χ 2 =5.19, P<0.05). Conclusion: Chronic low dose radiation may have effects on the cardiovascular sys-tem, so dynamic monitoring of changes in cardiac structure and function is worth on the safety and health for persons who may exposure to radiation and help to prevent early and long-term effects of radiation. (authors)

  4. Radiation-hardened control system

    International Nuclear Information System (INIS)

    Vandermolen, R.I.; Smith, S.F.; Emery, M.S.

    1993-01-01

    A radiation-hardened bit-slice control system with associated input/output circuits was developed to prove that programmable circuits could be constructed to successfully implement intelligent functions in a highly radioactive environment. The goal for this effort was to design and test a programmable control system that could withstand a minimum total dose of 10 7 rads (gamma). The Radiation Hardened Control System (RHCS) was tested in operation at a dose rate that ranged up to 135 krad/h, with an average total dose of 10.75 Mrads. Further testing beyond the required 10 7 rads was also conducted. RHCS performed properly through the target dose of 10 7 rads, and sporadic intermittent failures in some programmable logic devices were noted after ∼ 13 Mrads

  5. Computer-controlled radiation monitoring system

    International Nuclear Information System (INIS)

    Homann, S.G.

    1994-01-01

    A computer-controlled radiation monitoring system was designed and installed at the Lawrence Livermore National Laboratory's Multiuser Tandem Laboratory (10 MV tandem accelerator from High Voltage Engineering Corporation). The system continuously monitors the photon and neutron radiation environment associated with the facility and automatically suspends accelerator operation if preset radiation levels are exceeded. The system has proved reliable real-time radiation monitoring over the past five years, and has been a valuable tool for maintaining personnel exposure as low as reasonably achievable

  6. Fiber structural analysis by synchrotron radiation

    CERN Document Server

    Kojima, J I; Kikutani, T

    2003-01-01

    Topics of fiber structural analysis by synchrotron radiation are explained. There are only three synchrotron radiation facilities in the world, SPring-8 (Super Photon ring-8) in Japan, APS (Advanced Photon Source) in U.S.A. and ESRF (European Synchrotron Radiation Facility) in France. Online measurement of melt spinning process of PET and Nylon6 is explained in detail. Polypropylene and PBO (poly-p-phenylenebenzobisoxazole) was measured by WAXD (Wide Angle X-ray Diffraction)/SAXS (Small Angle X-ray Scattering) at the same time. Some examples of measure of drawing process of fiber are described. The structure formation process of spider's thread was measured. Micro beam of X-ray of synchrotron facility was improved and it attained to 65nm small angle resolving power by 10 mu m beamsize. (S.Y.)

  7. Control method and device for automatic drift stabilization in radiation detection

    International Nuclear Information System (INIS)

    Berthold, F.; Kubisiak, H.

    1979-01-01

    In the automatic control circuit individual electron peaks in the detectors, e.g. NaI crystals or proportional counters, are used. These peaks exhibit no drift dependence; they may be produced in the detectors in different ways. The control circuit may be applied in nuclear radiation measurement techniques, photometry, gamma cameras and for measuring the X-ray fine structure with proportional counters. (DG) [de

  8. The NSW Radiation Control Act and regulation

    International Nuclear Information System (INIS)

    Towson, J.

    1994-01-01

    The legal control of radiation safety in New South Wales has undergone substantial change in recent years. The long-awaited Regulation to the 1990 Radiation Control Act came into effect on 1 September 1993 (of necessity, as the Regulation to the previous 1957 Radioactive Substances Act expired on that date). It has not met with unanimous acclaim. The Regulation addresses three broad areas, namely - (a) legal controls - licensing, registration, radiation 'experts'; (b) safety matters - workplace management, monitoring, research exposures, transport/disposal, accidents; and (c) miscellaneous -radiation safety officers, committees, penalties, records, This article offers a personal view of the implications for nuclear medicine practice in New South Wales

  9. Non-destructive methods and means for quality control of structural products

    International Nuclear Information System (INIS)

    Dmitriev, V.V.

    1989-01-01

    Progressive non-destructive methods (acoustic, magnetic, radiation with liquid penetrants) and means of control of structural product quality, allowing to determine the state of products and structures not only immediately after their production but directly at the erected or reconstructed objects are described

  10. Radiation curable adhesive compositions and composite structures

    International Nuclear Information System (INIS)

    Brenner, W.

    1984-01-01

    This disclosure relates to novel adhesive compositions and composite structures utilizing the same, wherein said adhesive compositions contain an elastomer, a chemically compatible ethylenically unsaturated monomer, a tackifier, an adhesion promoter, and optionally, pigments, fillers, thickeners and flow control agents which are converted from the liquid to the solid state by exposure to high energy ionizing radiation such as electron beam. A particularly useful application for such adhesive compositions comprises the assembly of certain composite structures or laminates consisting of, for example, a fiber flocked rubber sheet and a metal base with the adhesive fulfilling the multiple functions of adhering the flocked fiber to the rubber sheet as well as adhering the rubber sheet to the metal base. Optionally, the rubber sheet itself may also be cured at the same time as the adhesive composition with all operations being carried out at ambient temperatures and in the presence of air, with exposure of said assembly to selected dosages of high energy ionizing radiation. These adhesive compositions contain no solvents thereby almost eliminating air pollution or solvent toxicity problems, and offer substantial savings in energy and labor as they are capable of curing in very short time periods without the use of external heat which might damage the substrate

  11. Review of measures to control radiation

    International Nuclear Information System (INIS)

    Swindon, T.N.

    1980-03-01

    Methods used in Canada and the U.S.A. to overcome problems in the control of radiation, to prescribe standards and to ensure that compliance with the standards is achieved are reviewed. The relevant Acts and Regulations are outlined. Options which could be applied in Australia for effecting better control of radiation are suggested

  12. Effect of radiation on microtubule structure in cancer cells

    International Nuclear Information System (INIS)

    Tripath, Shambhoo Sharan; Panda, Dulal; Jayakumar, S.; Maikho, Thoh; Sandur, Santosh Kumar

    2017-01-01

    Microtubules (MT) are dynamic structural cellular components. In proliferating cells, they are essential components in cell division through the formation of the mitotic spindle. Radiotherapy is an integral part of cancer treatment for most of the solid cancers. Scanty data exists in the literature related to how ionizing radiation affects microtubule reorganization in tumor cells. In the present study, breast cancer cell line (MCF-7 cells) was exposed to different doses of radiation (2-10Gy). Cells were cultured for 24 h, fixed and stained with antitubulin antibody and subjected to immunofluorescence microscopy. In another experiment, cells were subjected to cold treatment for 5 min or 30 min for studying the disassembly of microtubules after 24 h of irradiation. Further, these cells were incubated at 37°C for 20 min for studying the reassembly of microtubules. Acetylation of microtubule was also examined after exposure of cells to radiation. Experiments were also performed by combining radiation with low concentration of CXI-Benzo 84 (MT destabilizing agent 1 and 2.5 uM). Exposure of MCF-7 cells to radiation lead to destabilization of microtubules. Interestingly, destabilization of microtubule was faster upon cold treatment in irradiated group as compared to control group. These cells failed to re-stabilize at 37°C. Radiation also reduced the acetylation level of microtubule. Combination treatment of CXI-Benzo 84 with radiation exhibited additive effect in terms of depolymerization of MT. Our results suggest that ionizing radiation indeed modulates microtubule dynamics. (author)

  13. No. 434 - Radiation Control Regulation 1993

    International Nuclear Information System (INIS)

    1993-01-01

    This Regulation, made under the Radiation Control Act 1990, replaces the Radioactive Substances Regulation 1959, repealed by the 1990 Act. It deals with licensing of the use of radioactive substances and radiation apparatus, regulates their use, disposal and transport. It also provides for radiation monitoring and emergency planning. (NEA)

  14. Realtime radiation exposure monitor and control apparatus

    International Nuclear Information System (INIS)

    Cowart, R.W.

    1981-01-01

    This patent application relates to an apparatus and methods used to obtain image information from modulation of a uniform flux. An exposure measuring apparatus is disclosed which comprises a multilayered detector structure having an external circuit connected to a transparent insulating layer and to a conductive plate a radiation source adapted to irradiate the detector structure with radiation capable of producing electron-hole pairs in a photoconductive layer of the detector wherein the flow of current within the external circuit is measured when the detector is irradiated by the radiation source. (author)

  15. Control panel for radiation around reactors (1963); Tableaux de controle des radiations aupres des piles (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Candes, P; Barthoux, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    This report outlines the general philosophy of radiation control in French reactors and their annexes. The supervision is carried out continuously from a central control panel on which appear all the measurements made and the alarm signals. The equipment is described; one item makes it possible to measure simultaneously the radioactive dusts and gases. The specifications of the alarm system, which is considered to be the most important are given. Finally a new measuring technique is proposed which makes it possible to reduce considerably the cost of radiation control while at the same time providing the results in a form in which they can be easily treated, in particular in the case of the calculation of total doses. (authors) [French] Ce rapport definit la philosophie generale du controle des radiations dans les piles francaises et dans leurs annexes. La surveillance se fait d'une maniere continue a partir d'un tableau de controle centralise ou sont reportees toutes les mesures et les signalisations d'alarme. On decrit les appareils utilises, dont un permet la mesure simultanee des poussieres et gaz radioactifs, et on definit les specifications de la fonction alarme qui est consideree comme la plus importante. Enfin on propose une nouvelle technique de mesure qui permettrait de reduire considerablement le cout du controle des radiations tout en fournissant des resultats plus facilement exploitables, en particulier pour le calcul des doses integrees. (auteurs)

  16. Propagation of synchrotron radiation through nanocapillary structures

    International Nuclear Information System (INIS)

    Bjeoumikhov, A.; Bjeoumikhova, S.; Riesemeier, H.; Radtke, M.; Wedell, R.

    2007-01-01

    The propagation of synchrotron radiation through nanocapillary structures with channel sizes of 200 nm and periods in the micrometer size has been studied experimentally. It was shown that the propagation through individual capillary channels has a mode formation character. Furthermore it was shown that during the propagation through capillary channels the coherence of synchrotron radiation is partially conserved. Interference of beams propagating through different capillary channels is observed which leads to a periodically modulated distribution of the radiation intensity in a plane far from the exit of the structure. These investigations are of high relevance for the understanding of X-ray transmission through nanocapillaries and the appearance of wave properties at this size scale

  17. Radiation damage studies of nuclear structural materials

    International Nuclear Information System (INIS)

    Barat, P.

    2012-01-01

    Maximum utilization of fuel in nuclear reactors is one of the important aspects for operating them economically. The main hindrance to achieve this higher burnups of nuclear fuel for the nuclear reactors is the possibility of the failure of the metallic core components during their operation. Thus, the study of the cause of the possibility of failure of these metallic structural materials of nuclear reactors during full power operation due to radiation damage, suffered inside the reactor core, is an important field of studies bearing the basic to industrial scientific views.The variation of the microstructure of the metallic core components of the nuclear reactors due to radiation damage causes enormous variation in the structure and mechanical properties. A firm understanding of this variation of the mechanical properties with the variation of microstructure will serve as a guide for creating new, more radiation-tolerant materials. In our centre we have irradiated structural materials of Indian nuclear reactors by charged particles from accelerator to generate radiation damage and studied the some aspects of the variation of microstructure by X-ray diffraction studies. Results achieved in this regards, will be presented. (author)

  18. Summary Report of Working Group 5: Beam and Radiation Generation, Monitoring, and Control

    International Nuclear Information System (INIS)

    Church, Mike; Kim, Kiyong

    2010-01-01

    This paper summarizes the activities and presentations of Working Group 5 of the Advanced Accelerator Concepts Workshop held at Annapolis, Maryland in June 2010. Working Group 5 touched on a broad range of topics in the fields of beam and radiation generation and their monitoring and control. These topics were not comprehensively covered in this Workshop, but rather the Working Group concentrated on specific new developments and recent investigations. The Working Group divided its sessions into four broad categories: cathodes and electron guns, radiation generation, beam diagnostics, and beam control and dynamics. This summary is divided into the same structure.

  19. Hybrid Active/Passive Control of Sound Radiation from Panels with Constrained Layer Damping and Model Predictive Feedback Control

    Science.gov (United States)

    Cabell, Randolph H.; Gibbs, Gary P.

    2000-01-01

    There has been considerable interest over the past several years in applying feedback control methods to problems of structural acoustics. One problem of particular interest is the control of sound radiation from aircraft panels excited on one side by a turbulent boundary layer (TBL). TBL excitation appears as many uncorrelated sources acting on the panel, which makes it difficult to find a single reference signal that is coherent with the excitation. Feedback methods have no need for a reference signal, and are thus suited to this problem. Some important considerations for the structural acoustics problem include the fact that the required controller bandwidth can easily extend to several hundred Hertz, so a digital controller would have to operate at a few kilohertz. In addition, aircraft panel structures have a reasonably high modal density over this frequency range. A model based controller must therefore handle the modally dense system, or have some way to reduce the bandwidth of the problem. Further complicating the problem is the fact that the stiffness and dynamic properties of an aircraft panel can vary considerably during flight due to altitude changes resulting in significant resonant frequency shifts. These considerations make the tradeoff between robustness to changes in the system being controlled and controller performance especially important. Recent papers concerning the design and implementation of robust controllers for structural acoustic problems highlight the need to consider both performance and robustness when designing the controller. While robust control methods such as H1 can be used to balance performance and robustness, their implementation is not easy and requires assumptions about the types of uncertainties in the plant being controlled. Achieving a useful controller design may require many tradeoff studies of different types of parametric uncertainties in the system. Another approach to achieving robustness to plant changes is to

  20. Radiation induced nano structures

    International Nuclear Information System (INIS)

    Ibragimova, E.M.; Kalanov, M.U.; Khakimov, Z.

    2006-01-01

    Full text: Nanometer-size silicon clusters have been attracting much attention due to their technological importance, in particular, as promising building blocks for nano electronic and nano photonic systems. Particularly, silicon wires are of great of interest since they have potential for use in one-dimensional quantum wire high-speed field effect transistors and light-emitting devices with extremely low power consumption. Carbon and metal nano structures are studied very intensely due to wide possible applications. Radiation material sciences have been dealing with sub-micron objects for a long time. Under interaction of high energy particles and ionizing radiation with solids by elastic and inelastic mechanisms, at first point defects are created, then they form clusters, column defects, disordered regions (amorphous colloids) and finally precipitates of another crystal phase in the matrix. Such irradiation induced evolution of structure defects and phase transformations was observed by X-diffraction techniques in dielectric crystals of quartz and corundum, which exist in and crystal modifications. If there is no polymorphism, like in alkali halide crystals, then due to radiolysis halogen atoms are evaporated from the surface that results in non-stoichiometry or accumulated in the pores formed by metal vacancies in the sub-surface layer. Nano-pores are created by intensive high energy particles irradiation at first chaotically and then they are ordered and in part filled by inert gas. It is well-known mechanism of radiation induced swelling and embrittlement of metals and alloys, which is undesirable for construction materials for nuclear reactors. Possible solution of this problem may come from nano-structured materials, where there is neither swelling nor embrittlement at gas absorption due to very low density of the structure, while strength keeps high. This review considers experimental observations of radiation induced nano-inclusions in insulating

  1. Regularities of radiation heredity

    International Nuclear Information System (INIS)

    Skakov, M.K.; Melikhov, V.D.

    2001-01-01

    One analyzed regularities of radiation heredity in metals and alloys. One made conclusion about thermodynamically irreversible changes in structure of materials under irradiation. One offers possible ways of heredity transmittance of radiation effects at high-temperature transformations in the materials. Phenomenon of radiation heredity may be turned to practical use to control structure of liquid metal and, respectively, structure of ingot via preliminary radiation treatment of charge. Concentration microheterogeneities in material defect structure induced by preliminary irradiation represent the genetic factor of radiation heredity [ru

  2. Radiation tolerant power converter controls

    CERN Document Server

    Todd, B; King, Q; Uznanski, S

    2012-01-01

    The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to signifi...

  3. Reduction of the radiating sound of a submerged finite cylindrical shell structure by active vibration control.

    Science.gov (United States)

    Kim, Heung Soo; Sohn, Jung Woo; Jeon, Juncheol; Choi, Seung-Bok

    2013-02-06

    In this work, active vibration control of an underwater cylindrical shell structure was investigated, to suppress structural vibration and structure-borne noise in water. Finite element modeling of the submerged cylindrical shell structure was developed, and experimentally evaluated. Modal reduction was conducted to obtain the reduced system equation for the active feedback control algorithm. Three Macro Fiber Composites (MFCs) were used as actuators and sensors. One MFC was used as an exciter. The optimum control algorithm was designed based on the reduced system equations. The active control performance was then evaluated using the lab scale underwater cylindrical shell structure. Structural vibration and structure-borne noise of the underwater cylindrical shell structure were reduced significantly by activating the optimal controller associated with the MFC actuators. The results provide that active vibration control of the underwater structure is a useful means to reduce structure-borne noise in water.

  4. Reduction of the Radiating Sound of a Submerged Finite Cylindrical Shell Structure by Active Vibration Control

    Directory of Open Access Journals (Sweden)

    Seung-Bok Choi

    2013-02-01

    Full Text Available In this work, active vibration control of an underwater cylindrical shell structure was investigated, to suppress structural vibration and structure-borne noise in water. Finite element modeling of the submerged cylindrical shell structure was developed, and experimentally evaluated. Modal reduction was conducted to obtain the reduced system equation for the active feedback control algorithm. Three Macro Fiber Composites (MFCs were used as actuators and sensors. One MFC was used as an exciter. The optimum control algorithm was designed based on the reduced system equations. The active control performance was then evaluated using the lab scale underwater cylindrical shell structure. Structural vibration and structure-borne noise of the underwater cylindrical shell structure were reduced significantly by activating the optimal controller associated with the MFC actuators. The results provide that active vibration control of the underwater structure is a useful means to reduce structure-borne noise in water.

  5. Labeling for Big Data in radiation oncology: The Radiation Oncology Structures ontology.

    Science.gov (United States)

    Bibault, Jean-Emmanuel; Zapletal, Eric; Rance, Bastien; Giraud, Philippe; Burgun, Anita

    2018-01-01

    Leveraging Electronic Health Records (EHR) and Oncology Information Systems (OIS) has great potential to generate hypotheses for cancer treatment, since they directly provide medical data on a large scale. In order to gather a significant amount of patients with a high level of clinical details, multicenter studies are necessary. A challenge in creating high quality Big Data studies involving several treatment centers is the lack of semantic interoperability between data sources. We present the ontology we developed to address this issue. Radiation Oncology anatomical and target volumes were categorized in anatomical and treatment planning classes. International delineation guidelines specific to radiation oncology were used for lymph nodes areas and target volumes. Hierarchical classes were created to generate The Radiation Oncology Structures (ROS) Ontology. The ROS was then applied to the data from our institution. Four hundred and seventeen classes were created with a maximum of 14 children classes (average = 5). The ontology was then converted into a Web Ontology Language (.owl) format and made available online on Bioportal and GitHub under an Apache 2.0 License. We extracted all structures delineated in our department since the opening in 2001. 20,758 structures were exported from our "record-and-verify" system, demonstrating a significant heterogeneity within a single center. All structures were matched to the ROS ontology before integration into our clinical data warehouse (CDW). In this study we describe a new ontology, specific to radiation oncology, that reports all anatomical and treatment planning structures that can be delineated. This ontology will be used to integrate dosimetric data in the Assistance Publique-Hôpitaux de Paris CDW that stores data from 6.5 million patients (as of February 2017).

  6. Radiation effects on structural ceramics in fusion

    International Nuclear Information System (INIS)

    Hopkins, G.R.; Price, R.J.; Trester, P.W.

    1986-01-01

    Ceramics are required to serve in a conventional role as electrical and thermal insulators and dielectrics in fusion power reactors. In addition, certain ceramic materials can play a unique structural role in fusion power reactors by virtue of their very low induced radioactivity from fusion neutron capture. The aspects of safety, long-term radioactive waste management, and personnel access for maintenance and repair can all be significantly improved by applying the low-activation ceramics to the structural materials of the first-wall and blanket regions of a fusion reactor. Achievement of long service life at high structural loads and thermal stresses on the materials exposed to high-radiation doses presents a critical challenge for fusion. In this paper, we discuss radiation effects on structural ceramics for fusion application

  7. An acoustic radiator with integrated cavity and active control of surface vibration

    NARCIS (Netherlands)

    Berkhoff, Arthur; Tajdari, Farnaz

    2017-01-01

    This paper presents a method to realize an acoustic source for low frequencies with relatively small thickness. A honeycomb plate structure which is open on one side combines the radiating surface and the major part of the air cavity. The vibration of the plate is controlled with a decentralized

  8. Radiation-hardened gate-around n-MOSFET structure for radiation-tolerant application-specific integrated circuits

    International Nuclear Information System (INIS)

    Lee, Min Su; Lee, Hee Chul

    2012-01-01

    To overcome the total ionizing dose effect on an n-type metal-oxide-semiconductor field-effect transistor (n-MOSFET), we designed a radiation-hardened gate-around n-MOSFET structure and evaluated it through a radiation-exposure experiment. Each test device was fabricated in a commercial 0.35-micron complementary metal-oxide-semiconductor (CMOS) process. The fabricated devices were evaluated under a total dose of 1 Mrad (Si) at a dose rate of 250 krad/h to obtain very high reliability for space electronics. The experimental results showed that the gate-around n-MOSFET structure had very good performance against 1 Mrad (Si) of gamma radiation, while the conventional n-MOSFET experienced a considerable amount of radiation-induced leakage current. Furthermore, a source follower designed with the gate-around transistor worked properly at 1 Mrad (Si) of gamma radiation while a source follower designed with the conventional n-MOSFET lost its functionality.

  9. Control of radioisotopes and radiation sources in Indonesia

    International Nuclear Information System (INIS)

    Ridwan, M.

    2001-01-01

    Radioisotopes and radiation sources are extensively used in Indonesia in medicine, industry, mining, agriculture and research. These materials are controlled by the regulatory authority, according to established legal procedures. The Nuclear Energy Control Board of Indonesia (BAPETEN), which was established in 1998 through the Nuclear Energy Act No. 10/1997, is entrusted with the control of any application of nuclear energy, including the application of radioisotopes and radiation sources, through regulation, licensing and inspection. The control is aimed to assure welfare, security and peace, the safety and health of workers and the public, and environmental protection. The number of licences issued to date is around 2400, consisting of 1600 licences for radioisotopes and radiation sources used in hospitals, 347 in radiography, 256 in industry, 53 in mining, and the rest in many other areas such as research and agriculture. A licence can cover one or more radioisotopes or radiation sources, depending on the location of the user institution. These radioisotopes and radiation sources are Co-60, Cs-137, Ir-192, Ra-226, Am-241, Sr-90, Kr-85, Pm-147, linear accelerator and X-ray, and short half-life radioisotopes such as I-125, I-131 and Tc-99m. There are 10 LINACs, 27 X-ray medicines, 61 radioisotope devices for Co-60 and Cs-137, and 10 mHDR Ir-192 for therapeutic purposes currently used in Indonesia and some Ra-226 in storage. Any activity related to the application of nuclear energy is required to be conducted in a manner which observes safety and security. According to the legal requirements, each user has to employ at least one radiation safety officer. To improve the control of the application of radiation sources and radioactive material in the country, BAPETEN introduced some new approaches to the users, including regular dialogues with radiation safety officers and the management of the users, requalification for radiation protection officers twice in five

  10. Japanese Structure Survey of Radiation Oncology in 2005 Based on Institutional Stratification of Patterns of Care Study

    International Nuclear Information System (INIS)

    Teshima, Teruki; Numasaki, Hodaka; Shibuya, Hitoshi; Nishio, Masamichi; Ikeda, Hiroshi; Ito, Hisao; Sekiguchi, Kenji; Kamikonya, Norihiko; Koizumi, Masahiko; Tago, Masao; Nagata, Yasushi; Masaki, Hidekazu; Nishimura, Tetsuo; Yamada, Shogo

    2008-01-01

    Purpose: To evaluate the structure of radiation oncology in Japan in terms of equipment, personnel, patient load, and geographic distribution to identify and improve any deficiencies. Methods and Materials: A questionnaire-based national structure survey was conducted between March 2006 and February 2007 by the Japanese Society of Therapeutic Radiology and Oncology. These data were analyzed in terms of the institutional stratification of the Patterns of Care Study. Results: The total numbers of new cancer patients and total cancer patients (new and repeat) treated with radiotherapy in 2005 were estimated at approximately 162,000 and 198,000, respectively. In actual use were 765 linear accelerators, 11 telecobalt machines, 48 GammaKnife machines, 64 60 Co remote-controlled after-loading systems, and 119 192 Ir remote-controlled after-loading systems. The linear accelerator systems used dual-energy function in 498 systems (65%), three-dimensional conformal radiotherapy in 462 (60%), and intensity-modulated radiotherapy in 170 (22%). There were 426 Japanese Society of Therapeutic Radiology and Oncology-certified radiation oncologists, 774 full-time equivalent radiation oncologists, 117 medical physicists, and 1,635 radiation therapists. Geographically, a significant variation was found in the use of radiotherapy, from 0.9 to 2.1 patients/1,000 population. The annual patient load/FTE radiation oncologist was 247, exceeding the Blue Book guidelines level. Patterns of Care Study stratification can clearly discriminate the maturity of structures according to their academic nature and caseload. Conclusions: The Japanese structure has clearly improved during the past 15 years in terms of equipment and its use, although the shortage of manpower and variations in maturity disclosed by this Patterns of Care Study stratification remain problematic. These constitute the targets for nationwide improvement in quality assurance and quality control

  11. Structured thermal surface for radiative camouflage.

    Science.gov (United States)

    Li, Ying; Bai, Xue; Yang, Tianzhi; Luo, Hailu; Qiu, Cheng-Wei

    2018-01-18

    Thermal camouflage has been successful in the conductive regime, where thermal metamaterials embedded in a conductive system can manipulate heat conduction inside the bulk. Most reported approaches are background-dependent and not applicable to radiative heat emitted from the surface of the system. A coating with engineered emissivity is one option for radiative camouflage, but only when the background has uniform temperature. Here, we propose a strategy for radiative camouflage of external objects on a given background using a structured thermal surface. The device is non-invasive and restores arbitrary background temperature distributions on its top. For many practical candidates of the background material with similar emissivity as the device, the object can thereby be radiatively concealed without a priori knowledge of the host conductivity and temperature. We expect this strategy to meet the demands of anti-detection and thermal radiation manipulation in complex unknown environments and to inspire developments in phononic and photonic thermotronics.

  12. Irradiation of: MOS field effect structures effect of the radiation dose

    International Nuclear Information System (INIS)

    Leray, J.L.

    1989-01-01

    The radiation effects on the structure and the operation of a metal-oxide semiconductor (MOS) are studied. The phenomenology of the radiation damage is analyzed as a function of the accumulated radiation dose and the time. The chronology of the phenomena which takes place in the oxide and the radiation transient phases in MOS structures are discussed. The equivalence of different radiations on SiO2 and other semiconductors is analyzed. The models applied to the study of the radiation permanent effects are reviewed [fr

  13. Radiation Protection Control Area Around Baggage Control X-ray Units

    International Nuclear Information System (INIS)

    Prlic, I.; Radalj, Z.; Milkovic-Kraus, S.; Cerovac, Z.

    2003-01-01

    The importance of prompt occupational dose reporting rises when dose is received within a short-time interval or when the radiation source suffers any technical failures. Radiation exposure is to be recognized as a private/or group hazard of each person alone. Actual radiation quality of the source is to be taken into account. To optimize the radiological radiation protection Quality Control measurements of the source are done. We have developed digital dosemeters of type ALARA OD2 for external dosimetry to be used for establishing the real pattern of occupational dose delivered to the workers or/and as the (Ort) professional environmental measuring station. We are using dosemeter to define the control areas and areas of concern - point (Ort) around the source. This upgrade to legal obligatory external (film badge) dosimetry will help us to ease defining the professional stuff and working places which are actually exposed to ionising radiation of concern and for which it is necessary to provide legally required, or even additional, occupational health care programme. This means the analysis of exposure situations for specific jobs near the X-ray equipment used for baggage control in the context of carrying out a detailed study for the optimisation of radiation protection. PC data readout from device forms a real time exposure dose rate pattern that proves that any worker or other employee working nearby the baggage X-ray unit is not obliged to undergo any legal occupational monitoring (dosimetry or health) hence the total dose per year will not exceed 1 mSv under the worst working conditions. (author)

  14. Regulatory control of low level radiation exposure in Tanzania

    International Nuclear Information System (INIS)

    Nyanda, A.M.; Muhogora, W.E.

    1997-01-01

    In Tanzania, the radiation protection law was issued in 1983. Under this law, the National Radiation Commission is responsible for safe uses of ionizing radiation. The regulatory control of the resulting doses from the uses of radiation sources in medicine, industry, research and teaching is presented. The system of control reflects the existing interactions between the National Radiation Commission and users through the established radiation protection infrastructure. From the national dose registry data, it is found that the highest annual individual doses over 10 years ago, came from less than 5% of total monitored workers and were in the range 10 - 15 mSv y -1 . The experienced radiation levels in uncontrolled areas of potential workplaces is less than 1 μSv h -1 . The possibility for associating such low dose levels to the effectiveness of the existing regulatory dose control framework is discussed. Despite of this achievement, the need to improve further the radiation protection and safety programs is found necessary. (author)

  15. A utility perspective on radiation worker access control systems

    International Nuclear Information System (INIS)

    Watson, B.A.; Goff, T.E.

    1984-01-01

    Based on an evaluation of the current commercial Radiation Worker Access Control Software Systems, Baltimore Gas and Electric Company has elected to design and develop a site specific access control and accountability system for the Calvert Cliffs Nuclear Power Plant. The vendor provided systems allow for radiation worker access control based on training and external exposure records and authorizations. These systems do not afford internal exposure control until after bioassay measurements or maximum permissible concentration-hours are tabulated. The vendor provided systems allow for data trending for ALARA purposes, but each software package must be modified to meet site specific requirements. Unlike the commercial systems, the Calvert Cliffs Radiological Controls and Accountability System (RCAS) will provide radiation worker exposure control, both internal and external. The RCAS is designed to fulfill the requirements by integrating the existing Radiation Safety, Dosemetry, and Training data bases with a comprehensive radiological surveillance program. Prior to each worker's entry into the Radiological Control Area; his training and qualifications, radiation exposure history and authorization, will be compared with administrative controls, such as radiation work permits, and respiratory protection requirements and the radiological conditions in the work area. The RCAS, a computer based applied health physics access control system is described as it is presently configured for development. The mechanisms for enhancing worker internal and external exposure controls are discussed. Proposed data application to both the Calvert Cliffs ALARA and outage planning programs is included

  16. New radiation technologies and methods for control of technological processes in metallurgy

    International Nuclear Information System (INIS)

    Zaykin, Yu.

    1996-01-01

    Radiation Technology of Metal and Ceramic Production with Enhanced Service Properties. Based on application of radiation technique in powder metallurgy the new technology for obtaining metals, alloys and ceramic materials with high service properties is worked out. Radiation processing of powder materials at the certain stage of the process leads to profound structure alterations at all further stages and eventually effects the properties of the resulting product. Theoretical calculation and experimental studies of electron-positron annihilation in powder-pressed samples showed that irradiation caused powder particles surface state changes favorable for further sintering and crystallization processes development. It is shown that irradiation of metal powders and powder-pressed samples by high energy electrons is technologically most efficient. The right choice of the type-and the mode of the radiation processing makes it possible to obtain metals, alloys and ceramic materials (Mo,Fe, W, Al, Ni, Cu, stainless steels, ceramics, etc.) with homogeneous structure and stable enhanced service properties. The project on radiation technology application to powder metallurgy represented by a group of authors was awarded with the diploma and the gold medal at the 22 International Exhibition of Inventions (Geneva, 1994). New Technologic Opportunities of the Chromium-Nickel Alloys Processing To obtain the required phase-structure state special methods of the chromium-nickel alloy processing for sensitive elastic devices production were worked out combining plastic deformation, thermal and radiation processing. It is shown that h-gbb phase transfer not observed before is possible in extremely non-equilibrium conditions under electron irradiation. It is established that the complex reaction of recrystallization and gb-phase deposition proceeds under electron irradiation at the room temperature when the certain threshold plastic deformation degree is reached that leads to the same

  17. Piezoelectric line moment actuator for active radiation control from light-weight structures

    Science.gov (United States)

    Jandak, Vojtech; Svec, Petr; Jiricek, Ondrej; Brothanek, Marek

    2017-11-01

    This article outlines the design of a piezoelectric line moment actuator used for active structural acoustic control. Actuators produce a dynamic bending moment that appears in the controlled structure resulting from the inertial forces when the attached piezoelectric stripe actuators start to oscillate. The article provides a detailed theoretical analysis necessary for the practical realization of these actuators, including considerations concerning their placement, a crucial factor in the overall system performance. Approximate formulas describing the dependency of the moment amplitude on the frequency and the required electric voltage are derived. Recommendations applicable for the system's design based on both theoretical and empirical results are provided.

  18. Radiation protection philosophy and control of radiation doses from nuclear waste disposal

    International Nuclear Information System (INIS)

    Bryant, P.M.

    1981-01-01

    The author has reviewed the concurrent developments in each of the three decades from 1950 to the present day in radiation protection philosophy and in the control of radioactive waste disposals, with particular reference to the control of radiation doses to the public from disposals from nuclear installations. In addition, the author has summarised the OECD Nuclear Energy Agency's optimisation study which is a generic analysis of the quantitative factors pertinent to the management of tritium, carbon-14, krypton-85 and iodine-129, identified as being the radionuclides in fuel cycle effluents likely to be significant in the radiation exposure of large populations. (author)

  19. Analytical analyses of active control of sound transmission through soft-core sandwich structures and double panel partitions

    OpenAIRE

    Sahu, Kiran Chandra

    2016-01-01

    Active structural acoustic control (ASAC) is a form of active noise control which focuses on the control of structural vibrations in a manner that minimizes acoustic radiation from a structure. The greatest difficulty ASAC suffers from is in finding an "optimal" error quantity, which can be easily implemented in a control algorithm. Volume velocity control (VVC) metric which is generally used in ASAC typically requires either a large number of sensors distributed across the entire structure, ...

  20. Dosimetry control for radiation processing - basic requirements and standards

    International Nuclear Information System (INIS)

    Ivanova, M.; Tsrunchev, Ts.

    2004-01-01

    A brief review of the basic international codes and standards for dosimetry control for radiation processing (high doses dosimetry), setting up a dosimetry control for radiation processing and metrology control of the dosimetry system is made. The present state of dosimetry control for food processing and the Bulgarian long experience in food irradiation (three irradiation facilities are operational at these moment) are presented. The absence of neither national standard for high doses nor accredited laboratory for calibration and audit of radiation processing dosimetry systems is also discussed

  1. Radiological control in fires involving radiation sources

    International Nuclear Information System (INIS)

    Franco, J.O.A.; Coelho, C.P.

    1984-01-01

    The copies used during the chatter by techniques from CDTN in the I Mineiro Symposium of Fire Engineering, are presented. The chatter was based on emergency radiation control course, given by CDTN. Basic concepts, such as nuclear physics fundaments, radiation nature and detection, radiation protection and practical aspects of radiological fire emergency, were enphasized. (M.C.K.) [pt

  2. BWR Radiation Assessment and Control Program: assessment and control of BWR radiation fields. Volume 1. Executive summary

    International Nuclear Information System (INIS)

    Anstine, L.D.

    1983-05-01

    This report covers work on the BWR Radiation Assessment and Control (BRAC) Program from 1978 to 1982. The major activities during this report period were assessment of the radiation-level trends in BWRs, evaluation of the effects of forward-pumped heater drains on BWR water quality, installation and operation of a corrosion-product deposition loop in an operating BWR, and analyzation of fuel-deposit samples from two BWRs. Radiation fields were found to be controlled by cobalt-60 and to vary from as low as 50 mr/hr to as high as 800 mr/hr on the recirculation-system piping. Detailed information on BWR corrosion films and system deposits is presented in the report. Additionally, the results of an oxygen-injection experiment and recontamination monitoring studies are provided

  3. Control of external radiation exposure

    International Nuclear Information System (INIS)

    Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

    2004-01-01

    The following subjects are discussed - Control of external radiation exposure: working time, working distance, shielding: Total Linear Attenuation Coefficient, Half-Value Layer (HVL), Tenth-Value Layer (TVL); Build-up Factor

  4. Quality control of radiation therapy in clinical trials

    International Nuclear Information System (INIS)

    Kramer, S.; Lustig, R.; Grundy, G.

    1983-01-01

    The RTOG is a group of participating institutions which has a major interest in furthering clinical radiation oncology. They have formulated protocols for clinical investigation in which radiation therapy is the major modality of treatment. In addition, other modalities, such as chemotherapy, radiation sensitizers, and hyperthermia, are used in combined approach to cancer. Quality control in all aspects of patient management is necessary to insure quality data. These areas include evaluation of pathology, physics, and dosimetry, and clinical patient data. Quality control is both time consuming and expensive. However, by dividing these tasks into various levels and time frames, by using computerized data-control mechanisms, and by employing appropriate levels of ancillary personnel expertise, quality control can improve compliance and decrease the cost of investigational trials

  5. Control of radiation sources in Japan

    International Nuclear Information System (INIS)

    Maki, S.

    2001-01-01

    The report refers to the regulations for radioactive material in force in Japan, and to the organizations with responsibilities for regulating radiation sources. An outline of the law regulating the use of radiation sources and radioactive materials is provided, including its scope, types of radiation sources under control, exemptions and the system of notification, authorization and inspection. The experience of Japan with orphan sources is presented in three different cases, and the measures carried out to store the orphan sources in safe conditions. (author)

  6. Bulgarian National System for Ionization Radiation Control in the Biosphere. Three basic principles, main features and specific aspects of application

    International Nuclear Information System (INIS)

    Vasilev, G.

    1994-01-01

    Some problems concerned with the structure of the national system for radiation control and 'de facto' situation in Bulgaria are outlined. The following three basic principles of such a system are discussed: 1. Radioecological principle; 2. Regulatory principle. Maximum permissible contamination level and exposure; 3. Control principle. Local variations of natural radiation background. 1 tab., 12 refs

  7. Achievement of radiative feedback control for long-pulse operation on EAST

    Science.gov (United States)

    Wu, K.; Yuan, Q. P.; Xiao, B. J.; Wang, L.; Duan, Y. M.; Chen, J. B.; Zheng, X. W.; Liu, X. J.; Zhang, B.; Xu, J. C.; Luo, Z. P.; Zang, Q.; Li, Y. Y.; Feng, W.; Wu, J. H.; Yang, Z. S.; Zhang, L.; Luo, G.-N.; Gong, X. Z.; Hu, L. Q.; Hu, J. S.; Li, J.

    2018-05-01

    The active feedback control of radiated power to prevent divertor target plates overheating during long-pulse operation has been developed and implemented on EAST. The radiation control algorithm, with impurity seeding via a supersonic molecular beam injection (SMBI) system, has shown great success in both reliability and stability. By seeding a sequence of short neon (Ne) impurity pulses with the SMBI from the outer mid-plane, the radiated power of the bulk plasma can be well controlled, and the duration of radiative control (feedforward and feedback) is 4.5 s during a discharge of 10 s. Reliable control of the total radiated power of bulk plasma has been successfully achieved in long-pulse upper single null (USN) discharges with a tungsten divertor. The achieved control range of {{f}rad} is 20%–30% in L-mode regimes and 18%–36% in H-mode regimes. The temperature of the divertor target plates was maintained at a low level during the radiative control phase. The peak particle flux on the divertor target was decreased by feedforward Ne injection in the L-mode discharges, while the Ne pulses from the SMBI had no influence on the peak particle flux because of the very small injecting volume. It is shown that although the radiated power increased, no serious reduction of plasma-stored energy or confinement was observed during the control phase. The success of the radiation control algorithm and current experiments in radiated power control represents a significant advance for steady-state divertor radiation and heat flux control on EAST for near-future long-pulse operation.

  8. Illumination and radiative cooling

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Shanhui; Raman, Aaswath Pattabhi; Zhu, Linxiao; Rephaeli, Eden

    2018-03-20

    Aspects of the present disclosure are directed to providing and/or controlling electromagnetic radiation. As may be implemented in accordance with one or more embodiments, an apparatus includes a first structure that contains an object, and a second structure that is transparent at solar wavelengths and emissive in the atmospheric electromagnetic radiation transparency window. The second structure operates with the first structure to pass light into the first structure for illuminating the object, and to radiatively cool the object while preserving the object's color.

  9. Quality Control of Concrete Structure For APR1400 Construction

    International Nuclear Information System (INIS)

    Seo, Inseop; Song, Changhak; Kim, Duill

    2012-01-01

    Nuclear structure shall be constructed to protect internal facilities in the normal operation against external accidents such as the radiation shielding, earthquakes and to be leak-proof of radioactive substances to the external environment in case of loss of coolants. containment and auxiliary building of nuclear power plants are built in reinforced concrete structures to maintain these protection functions. Nuclear structures shall be designed to ensure soundness in operation since they are located on the waterfront where is easy do drain the cooling water and so deterioration and damage of concrete structures caused by seawater can occur. Durability is ensured for concrete structures of APR1400, a Korea standard NPP, in compliance with all safety requirements. In particular, owners perform quality control directly on the production and pouring of cast in place concrete for the concrete structure construction to make sure concrete structures established with quality homogeneity and durability. This report is to look into the quality control standard and management status of cast in place concrete for APR1400 construction

  10. Radiation damage to DNA: The importance of track structure

    International Nuclear Information System (INIS)

    Hill, M.A.

    1999-01-01

    A wide variety of biological effects are induced by ionizing radiation, from cell death to mutations and carcinogenesis. The biological effectiveness is found to vary not only with the absorbed dose but also with the type of radiation and its energy, i.e., with the nature of radiation tracks. An overview is presented of some of the biological experiments using different qualities of radiation, which when compared with Monte Carlo track structure studies, have highlighted the importance of the localized spatial properties of stochastic energy deposition on the nanometer scale at or near DNA. The track structure leads to clustering of damage which may include DNA breaks, base damage etc., the complexity of the cluster and therefore its biological repairability varying with radiation type. The ability of individual tracks to produce clustered damage, and the subsequent biological response are important in the assessment of the risk associated with low-level human exposure. Recent experiments have also shown that biological response to radiation is not always restricted to the 'hit' cell but can sometimes be induced in 'un-hit' cells near by

  11. Regulated control of practices and radiation sources

    International Nuclear Information System (INIS)

    1992-01-01

    Excepting the radiation caused by the natural background radiation, the Executive Secretariat for Nuclear Affairs (SEAN) does not authorize any source no practice within the national territory that may imply exposure of a person to ionizing radiation unless this use is ruled. This document establishes the basic criteria to set up such system as well as to exclude or exempt practices and sources from this regulated control

  12. Radiation damage to DNA: The importance of track structure

    CERN Document Server

    Hill, M A

    1999-01-01

    A wide variety of biological effects are induced by ionizing radiation, from cell death to mutations and carcinogenesis. The biological effectiveness is found to vary not only with the absorbed dose but also with the type of radiation and its energy, i.e., with the nature of radiation tracks. An overview is presented of some of the biological experiments using different qualities of radiation, which when compared with Monte Carlo track structure studies, have highlighted the importance of the localized spatial properties of stochastic energy deposition on the nanometer scale at or near DNA. The track structure leads to clustering of damage which may include DNA breaks, base damage etc., the complexity of the cluster and therefore its biological repairability varying with radiation type. The ability of individual tracks to produce clustered damage, and the subsequent biological response are important in the assessment of the risk associated with low-level human exposure. Recent experiments have also shown that...

  13. A control system of radiation protection at HESYRL

    International Nuclear Information System (INIS)

    Li Yuxiong; Li Juexin; Ning Xinquan

    1990-01-01

    A control system for radiation protection at Hefei National Synchrotron Radiation Laboratory (HESYRL) consists of three parts. They are a personal radiation safety interlock system, an automatic environmental radiation monitoring system and a data logging and management system for area radiation monitoring. Two-year operating experiments have shown that this system is reasonably designed, reliable, high-sensitive and automatic. The design principle, construction and operating status of each part of the system are introduced

  14. Control of radiation-induced diarrhea with cholestyramine

    International Nuclear Information System (INIS)

    Heusinkveld, R.S.; Manning, M.R.; Aristizabal, S.A.

    1978-01-01

    Cholestyramine is a non-absorbable ion-exchange resin which specifically binds bile salts. We have treated seven patients with acute or chronic radiation-induced diarrhea that was refractory to the usual methods of control with cholestyramine. In each case, the diarrhea was controlled with cholestyramine. This observation supports previous experimental work with animals which indicated that bile salts contribute to the genesis of radiation-induced diarrhea. Cholestyramine is well-tolerated, but should not be administered with certain oral medications. The results of this small series are preliminary, but point the way toward a more extensive clinical trial to define the usefulness of cholestyramine in the treatment of refractory acute or chronic radiation-induced diarrhea

  15. Structure-borne sound structural vibrations and sound radiation at audio frequencies

    CERN Document Server

    Cremer, L; Petersson, Björn AT

    2005-01-01

    Structure-Borne Sound"" is a thorough introduction to structural vibrations with emphasis on audio frequencies and the associated radiation of sound. The book presents in-depth discussions of fundamental principles and basic problems, in order to enable the reader to understand and solve his own problems. It includes chapters dealing with measurement and generation of vibrations and sound, various types of structural wave motion, structural damping and its effects, impedances and vibration responses of the important types of structures, as well as with attenuation of vibrations, and sound radi

  16. Radiation-beam technologies of structural materials treatment

    International Nuclear Information System (INIS)

    Kalin, B.A.

    2001-01-01

    Considered in the paper are the most advanced and prospective radiation-beam technologies (RBT) for treatment of structural materials, as applied to modifying the structural-phase state in the surface layers of half-finished products and articles with the purpose to improve their service properties. Ion-beam, plasma, and ion-plasma, as well as the technologies based on the use of concentrated fluxes of energy, generated by laser radiation, high-power pulsed electron and ion beams, and high-temperature pulsed plasma fluxes are analysed. As applied to improvement of the corrosion and erosion resistance, breaking strength, friction and wear resistance, and crack resistance, the directions of the choice and the use of RBT have been considered for changes of the surface layer state by applying covers and films, and by a change of the surface topography (relief), surface structure and defects, and the element composition and phase state of materials [ru

  17. Cherenkov Radiation Control via Self-accelerating Wave-packets.

    Science.gov (United States)

    Hu, Yi; Li, Zhili; Wetzel, Benjamin; Morandotti, Roberto; Chen, Zhigang; Xu, Jingjun

    2017-08-18

    Cherenkov radiation is a ubiquitous phenomenon in nature. It describes electromagnetic radiation from a charged particle moving in a medium with a uniform velocity larger than the phase velocity of light in the same medium. Such a picture is typically adopted in the investigation of traditional Cherenkov radiation as well as its counterparts in different branches of physics, including nonlinear optics, spintronics and plasmonics. In these cases, the radiation emitted spreads along a "cone", making it impractical for most applications. Here, we employ a self-accelerating optical pump wave-packet to demonstrate controlled shaping of one type of generalized Cherenkov radiation - dispersive waves in optical fibers. We show that, by tuning the parameters of the wave-packet, the emitted waves can be judiciously compressed and focused at desired locations, paving the way to such control in any physical system.

  18. Methionine Uptake and Required Radiation Dose to Control Glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Iuchi, Toshihiko, E-mail: tiuchi@chiba-cc.jp [Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Hatano, Kazuo [Division of Radiation Oncology, Tokyo Bay Advanced Imaging and Radiation Oncology Clinic, Makuhari, Chiba (Japan); Uchino, Yoshio [Division of Nuclear Medicine, Chiba Ryogo Center, Chiba (Japan); Itami, Makiko [Division of Surgical Pathology, Chiba Cancer Center, Chiba (Japan); Hasegawa, Yuzo; Kawasaki, Koichiro; Sakaida, Tsukasa [Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Hara, Ryusuke [Division of Radiation Oncology, Chiba Cancer Center, Chiba (Japan)

    2015-09-01

    Purpose: The purpose of this study was to retrospectively assess the feasibility of radiation therapy planning for glioblastoma multiforme (GBM) based on the use of methionine (MET) positron emission tomography (PET), and the correlation among MET uptake, radiation dose, and tumor control. Methods and Materials: Twenty-two patients with GBM who underwent MET-PET prior to radiation therapy were enrolled. MET uptake in 30 regions of interest (ROIs) from 22 GBMs, biologically effective doses (BEDs) for the ROIs and their ratios (MET uptake:BED) were compared in terms of whether the ROIs were controlled for >12 months. Results: MET uptake was significantly correlated with tumor control (odds ratio [OR], 10.0; P=.005); however, there was a higher level of correlation between MET uptake:BED ratio and tumor control (OR, 40.0; P<.0001). These data indicated that the required BEDs for controlling the ROIs could be predicted in terms of MET uptake; BED could be calculated as [34.0 × MET uptake] Gy from the optimal threshold of the MET uptake:BED ratio for tumor control. Conclusions: Target delineation based on MET-PET was demonstrated to be feasible for radiation therapy treatment planning. MET-PET could not only provide precise visualization of infiltrating tumor cells but also predict the required radiation doses to control target regions.

  19. Effects of radiation on MOS structures and silicon devices

    International Nuclear Information System (INIS)

    Braeunig, D.; Fahrner, W.

    1983-02-01

    A comprehensive view of radiation effects on MOS structures and silicon devices is given. In the introduction, the interaction of radiation with semiconductor material is presented. In the next section, the electrical degradation of semiconductor devices due to this interaction is discussed. The commonly used hardening techniques are shown. The last section deals with testing of radiation hardness of devices. (orig.) [de

  20. Ionizing radiation

    International Nuclear Information System (INIS)

    Kruger, J.

    1989-01-01

    Ionizing radiation results in biological damage that differs from other hazardous substances and is highly dangerous to man. Ionizing radiation cannot be perceived by man's sense organs and the biological damage cannot be detected immediately afterwards (except in very high doses). Every human being is exposed to low doses of radiation. The structure of the atom; sources of ionizing radiation; radiation units; biological effects; norms for radiation protection; and the national control in South Africa are discussed. 1 fig., 5 refs

  1. Radiation defect formation in two-barrier structures based on silicon

    International Nuclear Information System (INIS)

    Madatov, R.S.; Abbasov, F.P.; Mustafayev, Yu.M.

    2013-01-01

    It was developed a silicon-based photodetector with high integral sensitivity in low-wave spectrum. It was investigated the effect of gamma radiation on the mechanism of current transport in the structure of Schottky barrier type and in transitions. It is shown that the double-barrier structures can improve the photovoltaic parameters of conventional detectors. For the first time it was obtained and studied the characteristics of two-barrier structures created on the same plane. The advantages over conventional structures are shown. The annealing point is changing the structure of radiation defects and leads to their disappearance

  2. Directional radiation pattern in structural-acoustic coupled system

    Science.gov (United States)

    Seo, Hee-Seon; Kim, Yang-Hann

    2005-07-01

    In this paper we demonstrate the possibility of designing a radiator using structural-acoustic interaction by predicting the pressure distribution and radiation pattern of a structural-acoustic coupling system that is composed by a wall and two spaces. If a wall separates spaces, then the wall's role in transporting the acoustic characteristics of the spaces is important. The spaces can be categorized as bounded finite space and unbounded infinite space. The wall considered in this study composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. This rather hypothetical circumstance is selected to study the general coupling problem between the finite and infinite acoustic domains. We developed an equation that predicts the energy distribution and energy flow in the two spaces separated by a wall, and its computational examples are presented. Three typical radiation patterns that include steered, focused, and omnidirected are presented. A designed radiation pattern is also presented by using the optimal design algorithm.

  3. Development, validation and routine control of a radiation process

    International Nuclear Information System (INIS)

    Kishor Mehta

    2010-01-01

    Today, radiation is used in industrial processing for variety of applications; from low doses for blood irradiation to very high doses for materials modification and even higher for gemstone colour enhancement. At present, radiation is mainly provided by either radionuclides or machine sources; cobalt-60 is the most predominant radionuclide in use. Currently, there are several hundred irradiation facilities worldwide. Similar to other industries, quality management systems can assist radiation processing facilities in enhancing customer satisfaction and maintaining and improving product quality. To help fulfill quality management requirements, several national and international organizations have developed various standards related to radiation processing. They all have requirements and guidelines for development, validation and routine control of the radiation process. For radiation processing, these three phases involve the following activities. Development phase includes selecting the type of radiation source, irradiation facility and the dose required for the process. Validation phase includes conducting activities that give assurance that the process will be successful. Routine control then involves activities that provide evidence that the process has been successfully realized. These standards require documentary evidence that process validation and process control have been followed. Dosimetry information gathered during these processes provides this evidence. (authors)

  4. Track structure theory in radiobiology and in radiation detection

    International Nuclear Information System (INIS)

    Katz, R.

    1978-01-01

    The response of biological cells, and many physical radiation and track detectors to ionizing radiations and to energetic heavily ionizing particles, results from the secondary and higher generation electrons ejected from the atoms and molecules of the detector by the incident primary radiation. The theory uses a calculation of the radial distribution of local dose deposited by secondary electrons (delta-rays) from an energetic heavy ion as a transfer function, relating the dose-response relation measured (or postulated) for a particular detector in a uniform radiation field (gamma-rays) to obtain the radial distribution in response about the ion's path, and thus the structure of the track of a particle. Subsequent calculations yield the response of the detector to radiation fields of arbitrary quality. The models which have been used for detector response arise from target theory, and are of the form of statistical models called multi-hit or multi-target detectors, in which it is assumed that there are sensitive elements (emulsion grains, or biological cell nuclei) which may require many hits (emulsion grains) or single hits in different targets (say, cellular chromosomes) in order to produce the observed end-point. Recent work has demonstrated that many-hit physical detectors do exist. From both emulsion sensitometry and from the structure of tracks of heavy ions, it can be shown that emulsion-developer combinations exist which yield many-hit response. There is also some evidence that the supralinearity in thermoluminescent dosimeters arises from a mixture of 1-hit and 2-hit response, perhaps of different trap structures within the same TLD crystal. These detectors can be expected to mimic the response of biological cells to radiations of different quality. Their patterns of response may help us to understand better the structure of particle tracks in SSNTD's. (author)

  5. PET radiation exposure control for nurses

    International Nuclear Information System (INIS)

    Kawabata, Yumiko; Kikuta, Daisuke; Anzai, Taku

    2005-01-01

    Recently, the number of clinical PET centers is increasing all over Japan. For this reason, the monitoring and control of radiation exposure of employees, especially nurses, in PET-dedicated clinics and institutions are becoming very important issues for their health. We measured the radiation exposure doses of the nurses working at Nishidai Diagnostic Imaging Center, and analyzed the exposure data obtained from them. The exposure doses of the nurses were found to be 4.8 to 7.1 mSv between April 2003 and March 2004. We found that the nurses were mostly exposed to radiation when they had to have contact with patients received an FDG injection or they had trouble with the FDG automatic injection system. To keep radiation exposure of nurses to a minimum we reconfirmed that a proper application of the three principles of protection against radiation exposure was vital. (author)

  6. Study of radiation induced structural changes in nitrile rubber

    International Nuclear Information System (INIS)

    Cardona, F.; Hill, D.J.T.; Pomery, P.J.; Whittaker, A.K.

    1996-01-01

    Full text: Copolymers of butadiene (BD) and acrylonitrile (AN) (NBR rubber), have become important commercial material. NBR rubbers are part of a larger classification of products often referred to as special-purpose rubbers. Oil resistance is the most important property of nitrile rubbers, and refer to the ability of the vulcanised product to retain its original physical properties such as modulus, tensile strength, abrasion resistance and dimensions, while in contact with oils and fuels. Despite these reported advantages very few studies have been conducted on the radiation yields and structural changes in nitrile rubbers during exposure to high energy radiation. In this study we are investigating the stability against gamma and UV radiation, to different doses in vacuum, of butadiene, acrylonitrile and NBR copolymers with different composition ratio BD/AN. The mechanism of radiation induced structural changes is being investigated using experimental techniques such as ESR, NMR (Solid-state), FT-IR, RAMAN and UV spectroscopy. Also is being investigated the effect of irradiation on the mechanical properties of stressed and unstressed samples by TGA, DSC, DMA, Instron and Creep Test measurements. So far the main effect have been a marked radiation-induced loss of unsaturation in the butadiene units, cis to trans isomerization and formation of crosslink structures (intermolecular and intramolecular). One of the main challenges in the studies of NBR polymers is to observe directly the crosslinks produces by the radiation induced chemical reactions. IR spectroscopy is unsuitable because of the low molar absorbity of the peaks related to intermolecular crosslinking and the overlapping of the peaks (1630-1670 cm-1) related to intramolecular crosslinking (cyclization), with conjugated and nonconjugated (-C=C-; -C=N-) double bonds. A. K. Whittaker has shown that crosslink structures in PBD can be detected and measured directly using solid-state 13 C NMR. This technique

  7. Radiation monitoring in the NPP environment, control of radioactivity in NPP-environment system

    International Nuclear Information System (INIS)

    Egorov, Yu.A.

    1987-01-01

    Problems of radiation monitoring and control of the NPP-environment system (NPPES) are considered. Radiation control system at the NPP and in the environment provides for the control of the NPP, considered as the source of radioactive releases in the environment and for the environmental radiation climate control. It is shown, that the radiation control of the NPP-environment system must be based on the ecological normalization principles of the NPP environmental impacts. Ecological normalization should be individual for the NPP region of each ecosystem. The necessity to organize and conduct radiation ecological monitoring in the NPP regions is pointed out. Radiation ecological monitoring will provide for both environmental current radiation control and information for mathematical models, used in the NPPES radiation control

  8. Active control of electromagnetic radiation through an enhanced thermo-optic effect

    Science.gov (United States)

    Sheng, Chong; Liu, Hui; Zhu, Shining; Genov, Dentcho A.

    2015-01-01

    The control of electromagnetic radiation in transformation optical metamaterials brings the development of vast variety of optical devices. Of a particular importance is the possibility to control the propagation of light with light. In this work, we use a structured planar cavity to enhance the thermo-optic effect in a transformation optical waveguide. In the process, a control laser produces apparent inhomogeneous refractive index change inside the waveguides. The trajectory of a second probe laser beam is then continuously tuned in the experiment. The experimental results agree well with the developed theory. The reported method can provide a new approach toward development of transformation optical devices where active all-optical control of the impinging light can be achieved. PMID:25746689

  9. Ultra-Wideband Printed Slot Radiators with Controllable Frequency Characteristics

    Directory of Open Access Journals (Sweden)

    S. L. Chernyshev

    2015-01-01

    Full Text Available We have studied the possibility of creating ultra-wideband (UWB antennas with controlled frequency response of matching based on the printed slot antenna Vivaldi by introducing controlled resonators directly into the structure of the radiator. In the area of irregular slotline there are printed switched resonators with variable capacitance (varactor model, which allow tuning the frequency characteristics for each state of switching cavities, providing bandpass and band-barrage properties of the antenna. The investigation of reconfigurable printed resonators in the system of reconfigurable resonators of a bandpass filter is conducted. The paper considers filter to provide restructuring in the band (3-9 GHz. Electrodynamic simulation of the device was carried out in the time domain using a finite integration method. A bandstop reconfigurable filter is also investigated. The filter located on the substrate opposite the slit is based on tunable L-shaped resonator that has one end connected to the short-circuitor through the board metallization; the other end remains open and is brought into the region of interaction with the slotline. Such filter provides an effective narrow-band suppression and can be easily tuned to the desired frequency channel. The combination of these two types of filters allows you to create a controlled print Vivaldi slot antenna with combined properties. The paper investigates parameters of the scattering and radiation pattern of the antenna in different modes.

  10. Altitude control performance improvement via preview controller for unmanned airplane for radiation monitoring system

    International Nuclear Information System (INIS)

    Sato, Masayuki; Muraoka, Koji; Hozumi, Koki; Sanada, Yukihisa; Yamada, Tsutomu; Torii, Tatsuo

    2017-01-01

    This paper is concerned with the design problem of preview altitude controller for Unmanned Airplane for Radiation Monitoring System (UARMS) to improve its control performance. UARMS has been developed for radiation monitoring around Fukushima Dai-ichi nuclear power plant which spread radiation contaminant due to the huge tsunamis caused by the Great East Japan Earthquake. The monitoring area contains flat as well as mountain areas. The basic flight controller has been confirmed to have satisfactory performance with respect to altitude holding; however, the control performance for variable altitude commands is not sufficient for practical use in mountain areas. We therefore design preview altitude controller with only proportional gains by considering the practicality and the strong requirement of safety for UARMS. Control performance of the designed preview controller was evaluated by flight tests conducted around Fukushima Sky Park. (author)

  11. Indirect radiation effects related to the environmental structure of targets

    International Nuclear Information System (INIS)

    Frankenberg, D.

    1976-01-01

    It is supposed, that in biological systems there are direct as well as indirect radiation effects. Their contributions to lethal effects depend mainly on two different kinds of structures within irradiated systems: the microscopic energy deposition patterns of radiation and the environmental structures of targets. The approach to determine these contributions of the lethal action of ionizing radiation in yeast cells was, to use chemical compounds, which specifically change the radical spectrum of water radiolysis. The efficiency of such chemical compounds in scavenging specifically water radicals was tested in aqueous solutions of thymine molecules, in which indirect radiation effects occur exclusively. The main result is, that the OH'-radical is by far the most effective radical to destroy thymine molecules. The relative contributions of direct and indirect radiation effects to lethal actions of ionizing radiation was investigated in yeast cells. The radical spectrum of water radiolysis was changed by bubbling the cell suspensions with different gases. The main result is, that there are no lethal radiation effects du to the action of water radicals

  12. Ionizing radiation for insect control in grain and grain products

    International Nuclear Information System (INIS)

    Tilton, E.W.; Brower, J.H.

    1987-01-01

    A technical review summarizes and discusses information on various aspects of the use of ionizing radiation for the control of insect infestation in grains and grain products. Topics include: the effects of ionizing radiation on insects infesting stored-grain products; the 2 main types of irradiators (electron accelerators; radioisotopes (e.g.: Co-60; Cs-137); dosimetry systems and methodology; variations in radiation resistance by stored-product pests; the proper selection of radiation dose; the effects of combining various treatments (temperature, infrared/microwave radiation, hypoxia, chemicals) with ionizing radiation; sublethal radiation for controlling bulk grain insects; the feeding capacity of irradiated insects; the susceptibility of insecticide-resistant insects to ionizing radiation; and the possible resistance of insects to ionizing radiation. Practical aspects of removing insects from irradiated grain also are discussed

  13. Radiation therapy quality control in MRCCC radiotherapy units

    International Nuclear Information System (INIS)

    Fielda Djuita; Rina Taurisia; Andreas Nainggolan

    2011-01-01

    Increasing cancer patients in Indonesia is not supported with the number of equipment that is able to treat cancer patients, especially in the radiation therapy field. Therefore, several private hospitals have joined to provide radiation therapy services and one of them is MRCCC. As a new hospital providing services in radiotherapy field, the writer tries to present our quality control program that we have done in our hospital. Purpose: As quality control to radiation therapy clinical practice. Methods: Descriptive essay of what we do in our institution. Conclusion: Average output photon and electron lower more than tolerance dose. (author)

  14. On achieving a uniform approach to radiation control in Australia

    International Nuclear Information System (INIS)

    Swindon, T. N.

    1995-01-01

    Legislation and the associated regulatory processes to control radiation exposure of persons in the workplace, of patients undergoing medical exposures and of members of the public have been in place in all Australian States, including the ACT and NT, for some decades. Most States have completely rewritten their original legislation and all have made minor modifications from time to time. As a consequence, the legislation and the regulatory processes and controls used in all the States differ considerably, although they all have the same intent. For many years now, attempts have been made to overcome problems arising from the differences in the radiation control legislation and practices. These have been through the preparation of recommendations and codes of practice by the Radiation Health Standing Committee (RHSC) of the NHMRC and through discussions by State radiation control officers in the Radiation Control Implementation Panel, which reports to the RHSC. The recommendations and codes of practice can be utilised by the States in their radiation control activities, but this procedure can be restricted by different requirements in State legislation. Despite the efforts to overcome the problems, the main stumbling block to the implementation of uniform control derives from the legislation currently in use in each state. It is seen that changes will take a number of years to implements and that changes to legislation would be a top priority

  15. Establishing control over nuclear materials and radiation sources in Georgia

    International Nuclear Information System (INIS)

    Basilia, G.

    2010-01-01

    Regulatory control over radiation sources in Georgia was lost after disintegration of the Soviet Union. A number of radiation accidents and illegal events occurred in Georgia. From 1999 Nuclear and Radiation Safety Service of the Ministry of Environmental Protection and Natural Resources is responsible for regulatory control over radiation sources in Georgia. US NRC Regulatory Assistance Program in Georgia Assist the Service in establishing long term regulatory control over sources. Main focuses of US NRC program are country-wide inventory, create National Registry of sources, safe storage of disused sources, upgrade legislation and regulation, implementation licensing and inspection activities

  16. Application of controlled radiation-induced degradation in polymers: less exploited aspect of radiation processing of polymers

    International Nuclear Information System (INIS)

    Haji Saeid, M.; Guven, O.

    2007-01-01

    Industrial use of ionizing radiation treatment has been most successful in applications related to polymeric materials. The polymer, plastics and rubber industries have benefited from the unique advantages of ionizing radiation since its inception as an industrial tool to modify their properties and manufacture novel materials with value addition to the end product. The established and emerging applications of electron beam processing of polymers are based on the well known ultimate effects of ionizing radiation on polymers namely, crosslinking, curing, grafting and chain scissioning. Radiation-induced crosslinking dominates most applications, whereas the chain scissioning effect is much less explored and currently limited to radiation-induced degradation of Teflon, cellulose and polypropylene. The controlling of radiation-induced degradation for achieving a target average molecular weight or distribution has been evaluated for some polysaccharides, biopolymers and waste inner tubes whereas mitigation of the degradative effects of radiation has been analyzed from the point of view of using certain stabilizers, copolymers and annealing at an appropriate temperature. Several new or highly specialized techniques such as positron annihilation lifetime spectroscopy. Rutherford backscattering, elastic recoil detection analysis and solid waste NMR spectroscopy and gas chromatography-mass spectroscopy have been applied to the study or radiation-induced degradation. New information has been collected on the morphological changes associated with radiation-induced degradation processes, including chain scission, oxidation and free volume alteration. The IAEA coordinated research project (CRP) on Controlling of Degradation Effects in Radiation Processing of Polymers dealt with the role and importance of using ionizing radiation in controlling properties of natural and synthetic polymers through its degradative effect. This paper provides a summary of most important results

  17. Controlling Energy Radiations of Electromagnetic Waves via Frequency Coding Metamaterials.

    Science.gov (United States)

    Wu, Haotian; Liu, Shuo; Wan, Xiang; Zhang, Lei; Wang, Dan; Li, Lianlin; Cui, Tie Jun

    2017-09-01

    Metamaterials are artificial structures composed of subwavelength unit cells to control electromagnetic (EM) waves. The spatial coding representation of metamaterial has the ability to describe the material in a digital way. The spatial coding metamaterials are typically constructed by unit cells that have similar shapes with fixed functionality. Here, the concept of frequency coding metamaterial is proposed, which achieves different controls of EM energy radiations with a fixed spatial coding pattern when the frequency changes. In this case, not only different phase responses of the unit cells are considered, but also different phase sensitivities are also required. Due to different frequency sensitivities of unit cells, two units with the same phase response at the initial frequency may have different phase responses at higher frequency. To describe the frequency coding property of unit cell, digitalized frequency sensitivity is proposed, in which the units are encoded with digits "0" and "1" to represent the low and high phase sensitivities, respectively. By this merit, two degrees of freedom, spatial coding and frequency coding, are obtained to control the EM energy radiations by a new class of frequency-spatial coding metamaterials. The above concepts and physical phenomena are confirmed by numerical simulations and experiments.

  18. Radiation swelling of steels with lath martensite-austenic structure

    International Nuclear Information System (INIS)

    Sagaradze, V.V.; Pavlov, V.A.; Alyab'ev, V.M.; Lapin, S.S.; Ermishkin, V.A.; Antonova, O.V.

    1987-01-01

    Influence of electron radiation in the column of the JEM-1000 electron microscope on radiation swelling of austenite as austenitic fields and thin plates surrounded by α-martensite crystals is investigated. Formation of lath structure of alternating dispersive plates of martensite and invert austenite formed as a result of partial inverse martensite transformation α→γ is shown to restrain radiation swelling and formation of vacancy voids in stainless steels

  19. A mathematical foundation for controlling radiation health risks

    International Nuclear Information System (INIS)

    Kumazawa, S.

    2000-01-01

    Radiation protection is to attain an adequate control of radiation health risk compared with other risks. Our society in the 21 st century is predicted by some experts to seek the high priority of safety for expanding activity of human beings. The law of controlling risks will be a key subject to serve the safety of human beings and their environment. The main principles of the ICRP system of radiological system are strongly relating to the general law of various risk controls. The individual-based protection concept clearly gives us a mathematical model of controlling risks in general. This paper discusses the simplest formulation of controlling risks in the ICRP system, including other relating systems. First, the basic characteristics of occupational exposure as a risk control is presented by analyzing the data compiled over half a century. It shows the relation ship between dose control levels and individually controlled doses. The individual-based control also exerts some influence on the resultant collective dose. The study of occupational exposure concludes the simple mathematical expression of controlling doses under the ICRP system as shown by Kumazawa and Numakunai. Second, the typical characteristics of biological effects with repair or recovery of bio-systems are given by analyzing the data published. Those show the relationship between dose and biologically controlled or regulated response. The bio-system is undoubtedly relating to cybernetics that contains many functions of controlling risks. Consequently radiation effects might somewhat express the feature of biological risk controls. The shouldered survival of irradiated cells shows cybernetic characteristics that are assumed to be the mathematical foundation of controlling risks. The dose-response relationship shows another type of cybernetic characteristics, which could be reduced to the same basic form of controlling risks. The limited study of radiation effects definitely confirms the two

  20. Development of quality control procedures at a new radiation therapy centre

    International Nuclear Information System (INIS)

    Cooper, A.

    1999-01-01

    Before patients can be treated with radiation therapy, the radiation therapist must be certain that the equipment is functioning within specified parameters. When commencing a new service, introducing appropriate Quality Control procedures on all equipment can be a major accomplishment. At the North Queensland Oncology Service, the Radiation Therapists are responsible for the daily Quality Control on all the radiation therapy equipment. The documentation and procedures were developed by radiation therapists to ensure that all machine parameter discrepancies would be detected before a patient was treated. Monthly Quality Control is the responsibility of the Physics Department. These are carried out on the bi-weekly service days rostered for each linear accelerator and monthly for the simulator. Ongoing Quality Control and Maintenance Meetings ensures reporting and feedback is ongoing between the Radiation Therapists and Physicists. All other liaising is done through the Deputy Chief Radiation Therapist and Senior Physicist. Copyright (1999) Australian Institute of Radiography

  1. CRIE, radiation control in children in Extremadura (Spain)

    International Nuclear Information System (INIS)

    Rodriguez Llanos, R.; Jimenez Matas, A.; Gallardo Berrocal, M. C.; Villalobos Avila, M. A.

    2006-01-01

    The Department of Health of Extremadura, runs the Programme for the Control of Diagnostic Radiation Doses received by Children in Extremadura (CRIE in Spanish). This Programme aims to improve the quality of the medical assistance for children in our region. One way to guarantee this quality is to control the use of ionizing radiations in explorations for diagnostic and therapeutic purposes. This radiations must be justified and done in the appropriate facilities, using the lowest dose level. to achieve this goal, the CRIE Programme warns the following people about the risks that radiation can entail: Responsible people (parents or tutors). People prescribing diagnostic tests (doctors) Professionals who do the tests (radiologists, nuclear medicine specialists, technicians and nursing personnel). The control is carried out with the help of the CRIE card, assigned to every child under 14, on which every radiologic exploration and its date must be recorded. The CRIE cards are available in the doctors surgeries of the hospitals, in the maternity wards and in the Radiodiagnosis, Radiotherapy and Nuclear Medicine Services. (Author)

  2. Control of the radiation environment and the worker in high-energy facilities

    International Nuclear Information System (INIS)

    Stevenson, G.R.

    1993-01-01

    The philosophy behind the prediction, measurement, monitoring and limitation by access control of the radiation hazard in high-energy accelerator facilities is compared with that which could be employed for controlling similar hazards due to cosmic radiation in civil aircraft flights. Special mention is made of computer simulations of the radiation environment as a means of predicting necessary control measures, of the reliability and integration of radiation measuring devices into control procedures and of the relevance of different access control procedures. (author)

  3. Theoretical and experimental investigation of atomic radiative lifetimes and hyperfine structures

    International Nuclear Information System (INIS)

    Joensson, Per.

    1992-01-01

    Atomic radiative lifetimes and hyperfine structures as well as other properties, such as total energy and specific mass shift, have been studied theoretically and experimentally. Computer programs to calculate hyperfine structure constants from non-relativistic multiconfiguration Hartree-Fock (MCHF) and relativistic multi-configuration Dirac-Fock (MCDF) wavefunctions have been written. Using these programs large-scale calculations of hyperfine structures in lithium and sodium have been performed. It is shown, that the MCHF method is able to predict hyperfine structures to an accuracy of a few per mille in lithium, whereas for the more complex hyperfine structures to an accuracy of a few per mille in lithium, whereas for the more complex sodium atom an accuracy of a few per cent is obtainable. For lithium convergence of the total energy, ionization energy, specific mass shift and hyperfine parameters has been studied with the MCHF method. Radiative lifetimes and hyperfine structures of excited states in sodium and silver have been experimentally determined using time-resolved laser spectroscopy. By recording the fluorescence light decay curves following VUV excitation, the radiative lifetimes and hyperfine structures of the 7p 2 P states in silver were measured. The delayed-coincidence technique has been used to make very accurate measurements of the radiative lifetimes and hyperfine structures of the lowest P states in sodium and silver

  4. Regulatory control and safety of radiation and radioactive sources in Bangladesh

    International Nuclear Information System (INIS)

    Mollah, A.S.

    2001-01-01

    The application of ionizing radiation and radioactive sources in different fields such as, medicine, industry, agriculture, research and teaching is constantly increasing in Bangladesh. Any system enacted to control exposure to ionizing radiation has as primary objective the protection of health of people against the deleterious effects of radiation. Establishing the appropriate level of radiological protection and safety of radiation sources used in practice or intervention attains this objective. The regulatory program governing the safe use of radioactive and radiation sources in Bangladesh is based on the legislation enacted as Nuclear Safety and Radiation Control (NSRC) Act-93 and NSRC Rules-97 and its implementation by the competent authority. The radiation control infrastructures and procedure are described as well as their functioning for the implementation of relevant activities such as licensing, regular inspection, personal dose monitoring, emergency preparedness, etc. The issue of security of radiation source is dealt in close relation with the preparation and use of the inventory of all radiation sources in the country

  5. Multi-functional layered structure having structural and radiation shielding attributes

    Science.gov (United States)

    Kaul, Raj K. (Inventor); Barghouty, Abdulnasser Fakhri (Inventor); Penn, Benjamin G. (Inventor); Hulcher, Anthony Bruce (Inventor)

    2010-01-01

    A cosmic and solar radiation shielding structure that also has structural attributes is comprised of three layers. The first layer is 30-42 percent by volume of ultra-high molecular weight (UHMW) polyethylene fibers, 18-30 percent by volume of graphite fibers, and a remaining percent by volume of an epoxy resin matrix. The second layer is approximately 68 percent by volume of UHMW polyethylene fibers and a remaining percent by volume of a polyethylene matrix. The third layer is a ceramic material.

  6. Use of informatics in radiation control panels

    International Nuclear Information System (INIS)

    Cochinal, R.; Grimont, B.; Mai, V.

    1980-03-01

    Radiation control panels with programmed systems have developed at the CEA over the last few years. Each monitored location is provided with an monitoring station containing: - a radiation detector and associated electronics (the output signal is normalised calibrated pulses), - an alarm unit to warn personnal of any danger inside the detection zone covered [fr

  7. Structural sensing of interior sound for active control of noise in structural-acoustic cavities.

    Science.gov (United States)

    Bagha, Ashok K; Modak, S V

    2015-07-01

    This paper proposes a method for structural sensing of acoustic potential energy for active control of noise in a structural-acoustic cavity. The sensing strategy aims at global control and works with a fewer number of sensors. It is based on the established concept of radiation modes and hence does not add too many states to the order of the system. Acoustic potential energy is sensed using a combination of a Kalman filter and a frequency weighting filter with the structural response measurements as the inputs. The use of Kalman filter also makes the system robust against measurement noise. The formulation of the strategy is presented using finite element models of the system including that of sensors and actuators so that it can be easily applied to practical systems. The sensing strategy is numerically evaluated in the framework of Linear Quadratic Gaussian based feedback control of interior noise in a rectangular box cavity with a flexible plate with single and multiple pairs of piezoelectric sensor-actuator patches when broadband disturbances act on the plate. The performance is compared with an "acoustic filter" that models the complete transfer function from the structure to the acoustic domain. The sensing performance is also compared with a direct estimation strategy.

  8. Radiation control around the proton synchrotron Saturne (1962)

    International Nuclear Information System (INIS)

    Joffre, H.; Lamberieux, J.; Stirling, A.

    1962-01-01

    After giving the main characteristics of the Synchrotron at Saclay, the authors present on the one hand the general arrangements made for ensuring the safety of the personnel: specification of radiation levels, automatic devices, visual indications, etc... and on the other hand, the means employed for radiation detection. These detection methods include fixed γ and fast neutron detectors whose indications are centralised on a radiation control panel, and mobile detectors for specific or more precise measurements. The authors give results of radiation level measurements and some results of the diminishing of radiation intensity by wood, concrete and water. (author) [fr

  9. Regulatory control of radiation sources in Slovakia

    International Nuclear Information System (INIS)

    Auxtova, L.

    2001-01-01

    In Slovakia, there are two regulatory authorities. Regulatory control of the utilization of nuclear energy, based on the Slovak National Council's law No. 130/1998 on the peaceful uses of nuclear energy, is exercised by the Nuclear Regulatory Authority of the Slovak Republic. The second regulatory authority - the Ministry of Health - is empowered by law No. 72/1994 on the protection of human health to license radiation sources and is responsible for radiation protection supervision (there are nearly 3000 establishments with sealed sources, radiation generators and unsealed sources in Slovakia). Pursuant to a new radiation protection regulation based on international standards, radiation sources are to be categorized in six classes according to the associated exposure and contamination hazards. A national strategy for improving the safety of radiation sources over their life-cycle and for the management of disused and orphan sources is being prepared for governmental approval. (author)

  10. Effects of Voice Rehabilitation After Radiation Therapy for Laryngeal Cancer: A Randomized Controlled Study

    International Nuclear Information System (INIS)

    Tuomi, Lisa; Andréll, Paulin; Finizia, Caterina

    2014-01-01

    Background: Patients treated with radiation therapy for laryngeal cancer often experience voice problems. The aim of this randomized controlled trial was to assess the efficacy of voice rehabilitation for laryngeal cancer patients after having undergone radiation therapy and to investigate whether differences between different tumor localizations with regard to rehabilitation outcomes exist. Methods and Materials: Sixty-nine male patients irradiated for laryngeal cancer participated. Voice recordings and self-assessments of communicative dysfunction were performed 1 and 6 months after radiation therapy. Thirty-three patients were randomized to structured voice rehabilitation with a speech-language pathologist and 36 to a control group. Furthermore, comparisons with 23 healthy control individuals were made. Acoustic analyses were performed for all patients, including the healthy control individuals. The Swedish version of the Self Evaluation of Communication Experiences after Laryngeal Cancer and self-ratings of voice function were used to assess vocal and communicative function. Results: The patients who received vocal rehabilitation experienced improved self-rated vocal function after rehabilitation. Patients with supraglottic tumors who received voice rehabilitation had statistically significant improvements in voice quality and self-rated vocal function, whereas the control group did not. Conclusion: Voice rehabilitation for male patients with laryngeal cancer is efficacious regarding patient-reported outcome measurements. The patients experienced better voice function after rehabilitation. Patients with supraglottic tumors also showed an improvement in terms of acoustic voice outcomes. Rehabilitation with a speech-language pathologist is recommended for laryngeal cancer patients after radiation therapy, particularly for patients with supraglottic tumors

  11. Effects of Voice Rehabilitation After Radiation Therapy for Laryngeal Cancer: A Randomized Controlled Study

    Energy Technology Data Exchange (ETDEWEB)

    Tuomi, Lisa, E-mail: lisa.tuomi@vgregion.se [Department of Otorhinolaryngology, Head and Neck Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden); Andréll, Paulin [Department of Molecular and Clinical Medicine/Multidisciplinary Pain Center, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden); Finizia, Caterina [Department of Otorhinolaryngology, Head and Neck Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden)

    2014-08-01

    Background: Patients treated with radiation therapy for laryngeal cancer often experience voice problems. The aim of this randomized controlled trial was to assess the efficacy of voice rehabilitation for laryngeal cancer patients after having undergone radiation therapy and to investigate whether differences between different tumor localizations with regard to rehabilitation outcomes exist. Methods and Materials: Sixty-nine male patients irradiated for laryngeal cancer participated. Voice recordings and self-assessments of communicative dysfunction were performed 1 and 6 months after radiation therapy. Thirty-three patients were randomized to structured voice rehabilitation with a speech-language pathologist and 36 to a control group. Furthermore, comparisons with 23 healthy control individuals were made. Acoustic analyses were performed for all patients, including the healthy control individuals. The Swedish version of the Self Evaluation of Communication Experiences after Laryngeal Cancer and self-ratings of voice function were used to assess vocal and communicative function. Results: The patients who received vocal rehabilitation experienced improved self-rated vocal function after rehabilitation. Patients with supraglottic tumors who received voice rehabilitation had statistically significant improvements in voice quality and self-rated vocal function, whereas the control group did not. Conclusion: Voice rehabilitation for male patients with laryngeal cancer is efficacious regarding patient-reported outcome measurements. The patients experienced better voice function after rehabilitation. Patients with supraglottic tumors also showed an improvement in terms of acoustic voice outcomes. Rehabilitation with a speech-language pathologist is recommended for laryngeal cancer patients after radiation therapy, particularly for patients with supraglottic tumors.

  12. Three cases of radiation esophagitis controlled with proton pump inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Ryuji; Saito, Ryuichi; Miyazaki, Toshiyuki [Kumamoto Red Cross Hospital (Japan)

    2002-04-01

    Radiation esophagitis sometimes interrupts the radiation therapy due to swallowing pain and dysplasia. We experienced three cases of radiation-induced esophagitis controlled with proton pump inhibitor (PPI). These cases suggested etiologic relationship radiation esophagitis and gastroesophageal reflux disease (GERD). We should consider PPI as treatment option for radiation esophagitis. (author)

  13. Handbook of engineering control methods for occupational radiation protection

    International Nuclear Information System (INIS)

    Orn, M.K.

    1992-01-01

    Sources of ionizing and non-ionizing radiation are widely used in industrial, medical, military, and other applications. In the workplace, the task of assuring the safety of workers exposed to radiation sources is generally assigned to the safety professional, industrial hygienist, or an engineer in some other discipline. Rarely do employers outside the nuclear industry have the luxury of a staff health physicist in the workplace. Consultants may be called in to provide initial assessments of the hazards and to assist with complex problems, but the day-to-day problem solving is usually a function of the safety professional or other professional with the responsibility for safety. The primary purpose of this book is to provide a practical reference for safety professionals that addresses the application of ionizing and non-ionizing radiation protection standards and the quantitative methods for evaluating and designing engineering controls to meet those standards. Although the emphasis of this book is on control methods, it is necessary to understand the physical nature of the radiation exposure, its units of measure, and its biological effects in order to apply the appropriate control methods. Consequently, a brief treatment of these topics precedes the discussion of control methods for each type of radiation exposure

  14. Radiation-induced structural changes, (2)

    International Nuclear Information System (INIS)

    Ogasawara, M.; Matsuyama, T.

    1992-11-01

    This seminar is aimed at understanding both the physical and chemical aspects of the structural changes of materials induced by photons or ionizing radiation. The seminar was held on December 19th, 1991 and from February 13 to 14th, 1992 in this institute. The most active areas of the material science, in addition to the previous subjects, such as organic superconductors, silicon-based polymers, and fullerenes were included in this seminar. (J.P.N.)

  15. Optically controlled photonic bandgap structures for microstrip circuits

    International Nuclear Information System (INIS)

    Cadman, Darren Arthur

    2003-01-01

    This thesis is concerned with the optical control of microwave photonic bandgap circuits using high resistivity silicon. Photoconducting processes that occur within silicon are investigated. The influence of excess carrier density on carrier mobility and lifetime is examined. In addition, electron-hole pair recombination mechanisms (Shockley-Read-Hall, Auger, radiative and surface) are investigated. The microwave properties of silicon are examined, in particular the variation of silicon reflectivity with excess carrier density. Filtering properties of microstrip photonic bandgap structures and how they may be controlled optically are studied. A proof-of-concept microstrip photonic bandgap structure with optical control is designed, simulated and measured. With no optical illumination incident upon the silicon, the microstrip photonic bandgap structure's filtering properties are well-defined; a 3dB stopband width of 2.6GHz, a 6dB bandwidth of 2GHz and stopband depth of -11.6dB at the centre frequency of 9.9GHz. When the silicon is illuminated, the structure's filtering properties are suppressed. Under illumination the experimental results display an increase in S 21 of 6.5dB and a reduction in S 11 of more than 10dB at 9.9GHz. A comparison of measured and simulated results reveal that the photogenerated excess carrier density is between 4 x 10 15 cm -3 and 1.1 x 10 16 cm -3 . (author)

  16. Galactic structure and gamma radiation

    International Nuclear Information System (INIS)

    Casse, Michel; Cesarsky, Catherine; Paul Jacques

    1977-01-01

    A model of spiral structure of the Galaxy is outlined from radiosynchrotron and gamma observations. The most interesting observations in the galactic context, obtained by the SAS II American satellite are concerned with the distribution of the γ photoemission at energies higher than 10 8 eV, along the galactic equator. The model proposed is in quantitative agreement with the present ideas on the spiral structure of the Galaxy, the galactic magnetic field, and the confinement of cosmic rays by the magnetic field and of the magnetic field by matter. Following the American era, the European COS-B satellite opens the European phase towards an identification of the discrete gamma radiation sources [fr

  17. Application of systems and control theory-based hazard analysis to radiation oncology.

    Science.gov (United States)

    Pawlicki, Todd; Samost, Aubrey; Brown, Derek W; Manger, Ryan P; Kim, Gwe-Ya; Leveson, Nancy G

    2016-03-01

    Both humans and software are notoriously challenging to account for in traditional hazard analysis models. The purpose of this work is to investigate and demonstrate the application of a new, extended accident causality model, called systems theoretic accident model and processes (STAMP), to radiation oncology. Specifically, a hazard analysis technique based on STAMP, system-theoretic process analysis (STPA), is used to perform a hazard analysis. The STPA procedure starts with the definition of high-level accidents for radiation oncology at the medical center and the hazards leading to those accidents. From there, the hierarchical safety control structure of the radiation oncology clinic is modeled, i.e., the controls that are used to prevent accidents and provide effective treatment. Using STPA, unsafe control actions (behaviors) are identified that can lead to the hazards as well as causal scenarios that can lead to the identified unsafe control. This information can be used to eliminate or mitigate potential hazards. The STPA procedure is demonstrated on a new online adaptive cranial radiosurgery procedure that omits the CT simulation step and uses CBCT for localization, planning, and surface imaging system during treatment. The STPA procedure generated a comprehensive set of causal scenarios that are traced back to system hazards and accidents. Ten control loops were created for the new SRS procedure, which covered the areas of hospital and department management, treatment design and delivery, and vendor service. Eighty three unsafe control actions were identified as well as 472 causal scenarios that could lead to those unsafe control actions. STPA provides a method for understanding the role of management decisions and hospital operations on system safety and generating process design requirements to prevent hazards and accidents. The interaction of people, hardware, and software is highlighted. The method of STPA produces results that can be used to improve

  18. A comprehensive centralized control system for radiation waste treatment facility

    International Nuclear Information System (INIS)

    Kong Jinsong

    2014-01-01

    A comprehensive centralized control system is designed for the radiation waste treatment facility that lacking of coordinated operational mechanism for the radiation waste treatment. The centralized control and alarm linkage of various systems is implemented to ensure effectively the safety of nuclear facility and materials, improve the integral control ability through advanced informatization ways. (author)

  19. Acoustic radiation force control: Pulsating spherical carriers.

    Science.gov (United States)

    Rajabi, Majid; Mojahed, Alireza

    2018-02-01

    power supply for distinct cases of zero, negative and positive radiation force states along with the frequency dependent asymmetry index. In addition, considering the effect of phase difference between the incident wave field and the pulsating object, and its possible variation with respect to spatial position of object, some practical points about the spatial average of generated radiation force, the optimal state of operation, the stability of zero radiation force states and the possibly of precise motion control are discussed. This work would extend the novel concept of smart carriers to and may be helpful for robust single-beam acoustic handling techniques. Furthermore, the shown capability of precise motion control may be considered as a new way toward smart acoustic driven micro-mechanisms and micro-machines. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Radiation-Hygienic control of animal food in 1996

    International Nuclear Information System (INIS)

    Vicentijevic, M.; Vukovic, D.; Mitrovic, R.

    1997-01-01

    Radiation-hygienic control of animal food (concentrated fodder, row material for making fodder and food for pets) was done through the first and second circle of radiation biotechnology monitoring system (BIMOS) in 1996. The gamma-spectrometry determined activity of 137 Cs was less than 2,65 Bq/kg with one sample of fish flour exception (23,9 Bq/kg), so the completely radiation safety for animal food was confirmed. (author)

  1. A possible methodological approach to setting up control level of radiation factors

    International Nuclear Information System (INIS)

    Devyatajkin, E.V.; Abramov, Yu.V.

    1986-01-01

    The mathematical formalization of the concept of control levels (CL) which enables one to obtain CL numerical values of controllable parameters required for rapid control purposes is described. The initial data for the assessment of environmental radioactivity are the controllable parameter values that is practical characteristic of controllable radiation factor showing technically measurable or calculation value. The controllable parameters can be divided into two classes depending on the degree of radiation effect on a man: possessing additivity properties (dosimetric class) and non-possessing (radiation class, which comprises the results of control of medium alteration dynamics, equipment operation safety, completeness of protection measures performance). The CL calculation formulas with account for requirements of radiation safety standards (RSS-76) are presented

  2. Thermal/structural analysis of radiators for heavy-duty trucks

    International Nuclear Information System (INIS)

    Mao Shaolin; Cheng, Changrui; Li Xianchang; Michaelides, Efstathios E.

    2010-01-01

    A thermal/structural coupling approach is applied to analyze thermal performance and predict the thermal stress of a radiator for heavy-duty transportation cooling systems. Bench test and field test data show that non-uniform temperature gradient and dynamic pressure loads may induce large thermal stress on the radiator. A finite element analysis (FEA) tool is used to predict the strains and displacement of radiator based on the solid wall temperature, wall-based fluid film heat transfer coefficient and pressure drop. These are obtained from a computational fluid dynamics (CFD) simulation. A 3D simulation of turbulent flow and coupled heat transfer between the working fluids poses a major difficulty because the range of length scales involved in heavy-duty radiators varies from few millimeters of the fin pitch and/or tube cross-section to several meters for the overall size of the radiator. It is very computational expensive, if not impossible, to directly simulate the turbulent heat transfer between fins and the thermal boundary layer in each tube. In order to overcome the computational difficulties, a dual porous zone (DPZ) method is applied, in which fins in the air side and turbulators in the water side are treated as porous region. The parameters involved in the DPZ method are tuned based on experimental data in prior. A distinguished advantage of the porous medium method is its effectiveness of modeling wide-range characteristic scale problems. A parametric study of the impact of flow rate on the heat transfer coefficient is presented. The FEA results predict the maximum value of stress/strain and target locations for possible structural failure and the results obtained are consistent with experimental observations. The results demonstrate that the coupling thermal/structural analysis is a powerful tool applied to heavy-duty cooling product design to improve the radiator thermal performance, durability and reliability under rigid working environment.

  3. Regulatory control for safe usage of ionizing radiation sources in Bangladesh

    International Nuclear Information System (INIS)

    Mollah, A.S.

    2008-01-01

    Full text: In Bangladesh, there is a widespread and continuos growth in the use of the ionizing radiation sources both radioactive materials and radiation generating equipment in the field of industry, medicine, agriculture, research, teaching etc. In industry, they are employed in production as well as quality control such as non-destructive testing (radiography), nucleonic gauging, radiotracer techniques and in radiation processing. Medical applications of ionizing radiation include X-ray radiography, X-ray fluoroscopy, CT scan, mammography, nuclear medicine, beam therapy and brachytherapy. Besides radioisotopes are also used for research applications, viz., scattering experiments, tracer studies, etc. In agriculture, the uptake of nutrients by soil, and parts of plants are studied using suitable radionuclides. In all the above applications radioisotopes in two forms namely sealed sources and open sources in different chemical forms are employed with source strengths varying from micro curies to mega curies. The benefits to man from the use of ionizing radiation and sources of radiation are accompanied by risks which may result from exposure of man to ionizing radiation. In order to have an effective control on the use of radiation sources and to ensure radiological safety of the user as well as the public, Government of Bangladesh has promulgated Nuclear Safety and Radiation Control (NSRC) rules 1997 under the NSRC Act 1993. The Bangladesh Atomic Energy commission (BAEC) is the competent authority for formulating rules and regulations for ensuring radiological safety. BAEC is legally responsible for developing and strengthening the necessary radiation protection infrastructure in the country through the effective enforcement and implementation of regulatory requirements, criteria, obligations, guiding, codes etc. in order to save man and the related environment from the deleterious effects of ionizing radiation. In Bangladesh, only those persons who have been

  4. Proposed Radiation Control Act: discussion paper

    International Nuclear Information System (INIS)

    1989-01-01

    The history and nature of the present NSW Radioactive Substances Act passed in 1957 is outlined. The direction of reform is suggested and some options for changes presented. These include the extension of controls to cover non-ionising radiation, the introduction of controls over the mining and milling of radioactive ores, and improved licensing provisions. Professional and public comment is sought

  5. Ionizing radiations in Italian health care structures

    International Nuclear Information System (INIS)

    Fizzano, M.R.; Frusteri, L.

    2006-01-01

    The Council of the European Union has completely renewed the framework regarding radiation protection by adopting some directives: Directive 97/43 EURATOM lays down the general principles of the radiation protection of individuals undergoing exposure to ionising radiations related to medical exposures, as a supplement of Directive 96/29 EURATOM laying down the basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionising radiations.The incorporation into Italian legislation of the European Community directives on the improvement of health and safety at work has promoted a vast effort in order to revise the surveillance approach in many facilities, including hospitals. In Italy, safety law is referred to every workplace; anyway the use of ionising radiations is ruled by specific laws. So in the health care structures it is necessary integrating both the laws and this process is often difficult to carry on. The Italian Legislative Decree 230/95, one the main laws that aim to protect workers against ionising radiations, introduced Directive 96/29/EURATOM. This Decree asks that a doctor and a technical expert analyse the workplace and classify area and workers in according to dose of ionising radiation established by law. The Italian Legislative Decree 626/94 asks that risk analysis in general is made by doctor and specialist in risk. So, in case of risk from ionising radiation, all these figures have to cooperate in order to make an evaluation risk document. (N.C.)

  6. Ionizing radiations in Italian health care structures

    Energy Technology Data Exchange (ETDEWEB)

    Fizzano, M.R.; Frusteri, L. [Technical Advisory Dept. for Risk Assessment and Prevention, Italian Workers Compensation Authority, Rome (Italy)

    2006-07-01

    The Council of the European Union has completely renewed the framework regarding radiation protection by adopting some directives: Directive 97/43 EURATOM lays down the general principles of the radiation protection of individuals undergoing exposure to ionising radiations related to medical exposures, as a supplement of Directive 96/29 EURATOM laying down the basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionising radiations.The incorporation into Italian legislation of the European Community directives on the improvement of health and safety at work has promoted a vast effort in order to revise the surveillance approach in many facilities, including hospitals. In Italy, safety law is referred to every workplace; anyway the use of ionising radiations is ruled by specific laws. So in the health care structures it is necessary integrating both the laws and this process is often difficult to carry on. The Italian Legislative Decree 230/95, one the main laws that aim to protect workers against ionising radiations, introduced Directive 96/29/EURATOM. This Decree asks that a doctor and a technical expert analyse the workplace and classify area and workers in according to dose of ionising radiation established by law. The Italian Legislative Decree 626/94 asks that risk analysis in general is made by doctor and specialist in risk. So, in case of risk from ionising radiation, all these figures have to cooperate in order to make an evaluation risk document. (N.C.)

  7. Radiation practices and regulatory control

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The general principles to be observed in the regulatory control of ionizing radiation use and practices are specified in the guide. It also takes into account of additions and alterations needed for for compliance with the European Union (EU) directives that have not been mentioned in other STUK/ST-guides. (6 refs.).

  8. Radiation practices and regulatory control

    International Nuclear Information System (INIS)

    1997-01-01

    The general principles to be observed in the regulatory control of ionizing radiation use and practices are specified in the guide. It also takes into account of additions and alterations needed for for compliance with the European Union (EU) directives that have not been mentioned in other STUK/ST-guides. (6 refs.)

  9. Summary of radiation protection in exploitation

    International Nuclear Information System (INIS)

    Garcier, Yves; Guers, Rene; Bidard, Francoise; Colson, Philippe; Gonin, Michele; Delabre, Herve; Hemidy, Pierre-Yves; Corgnet, Bruno; Perrin, Marie-Claire; Phan Hoang, Long; Abela, Gonzague; Crepieux, Virginie; Guyot, Pierre; Haranger, Didier; Warembourg, Philippe

    2004-01-01

    This document proposes a large and detailed overview of notions and practices regarding radiation protection in relationship with an NPP exploitation framework. It presents the main notions: matter structure, radioactivity, interactions between matter and radiations, types of ionizing radiation, magnitudes and measurement units, exposure modes, main principles of radiation protection, means of protection against internal and external exposures. The second part proposes an overview of the origin of radiological risks in a nuclear power plant. This origin can be found in fission products, activation products, actinides, designed protections, or circuit contaminations. These radiological risks are more precisely identified and described in terms of detection and prevention (internal exposure risk, contamination risk, iodine-related risk, alpha radiation-related risk, access to the reactor building). The next part addresses the medical and radiological follow-up of exposed workers by a special medical control, by an individual exposure control, by a specific control of female personnel, and by attention to exceptional exposures. Measurement means are presented (detection principles, installation continuous control, workspaces control, personnel contamination control, follow-up of individual dose) as well as collective and individual protection means. The management of radiation protection is addressed through a presentation of decision and management structures for radiation protection, and of EDF objectives and ambitions in this domain. The organization of radiation protection during exploitation is described: responsibilities for radiation protection in a nuclear power station, requirements for workers, preparation of interventions in controlled zone, work execution in controlled zone, zone controls and radiological cleanness of installations. The two last chapters address issues and practices of radiation protection in the case of deconstruction or dismantling, and

  10. Dosimetry and process control for radiation processing

    International Nuclear Information System (INIS)

    Mod Ali, N.

    2002-01-01

    Complete text of publication follows. Accurate radiation dosimetry can provide quality assurance in radiation processing. Considerable relevant experiences in dosimetry by the SSDL-MINT has necessitate the development of methods making measurement at gamma plant traceable to the national standard. It involves the establishment of proper calibration procedure and selection of appropriate transfer system/technique to assure adequate traceability to a primary radiation standard. The effort forms the basis for irradiation process control, the legal approval of the process by the public health authorities (medical product sterilization and food preservation) and the safety and acceptance of the product

  11. Two-photon cavity solitons in a laser: radiative profiles, interaction and control

    Energy Technology Data Exchange (ETDEWEB)

    Serrat, C [Departament de FIsica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Colom 1, E-08222 Terrassa (Spain); Torrent, M C [Departament de FIsica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Colom 1, E-08222 Terrassa (Spain); Vilaseca, R [Departament de FIsica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Colom 1, E-08222 Terrassa (Spain); GarcIa-Ojalvo, J [Center for Applied Mathematics, Cornell University, Ithaca, NY 14853 (United States); Brambilla, M [Dipartimento di Fisica and INFM, Politecnico di Bari, Via E. Orabona 4, I-70126 Bari (Italy)

    2004-05-01

    We study the properties of two-photon cavity solitons that appear in a broad-area cascade laser. These vectorial solitons consist of islands of two-photon emission emerging over a background of single-photon emission. Analysis of their structural properties reveals singular features such as their short distance radiation of outgoing waves, which can be interpreted in terms of the soliton frequency profile. However, the phase of these solitons is not determined by any external factor, which influences the way in which the structures can be written and erased. We also examine ways of controlling the cavity-soliton position, and analyse the interaction between neighbouring cavity solitons. Finally, investigation of the parameter dependence of these structures shows a route from soliton-dominated to defect-mediated turbulence.

  12. Mass loss and chemical structures of wheat and maize straws in response to ultraviolet-B radiation and soil contact

    Science.gov (United States)

    Zhou, Guixiang; Zhang, Jiabao; Mao, Jingdong; Zhang, Congzhi; Chen, Lin; Xin, Xiuli; Zhao, Bingzi

    2015-01-01

    The role of photodegradation, an abiotic process, has been largely overlooked during straw decomposition in mesic ecosystems. We investigated the mass loss and chemical structures of straw decomposition in response to elevated UV-B radiation with or without soil contact over a 12-month litterbag experiment. Wheat and maize straw samples with and without soil contact were exposed to three radiation levels: a no-sunlight control, ambient solar UV-B, and artificially elevated UV-B radiation. A block control with soil contact was not included. Compared with the no-sunlight control, UV-B radiation increased the mass loss by 14–19% and the ambient radiation by 9–16% for wheat and maize straws without soil contact after 12 months. Elevated UV-B exposure decreased the decomposition rates of both wheat and maize straws when in contact with soil. Light exposure resulted in decreased O-alkyl carbons and increased alkyl carbons for both the wheat and maize straws compared with no-sunlight control. The difference in soil contact may influence the contribution of photodegradation to the overall straw decomposition process. These results indicate that we must take into account the effects of photodegradation when explaining the mechanisms of straw decomposition in mesic ecosystems. PMID:26423726

  13. Mass loss and chemical structures of wheat and maize straws in response to ultraviolet-B radiation and soil contact.

    Science.gov (United States)

    Zhou, Guixiang; Zhang, Jiabao; Mao, Jingdong; Zhang, Congzhi; Chen, Lin; Xin, Xiuli; Zhao, Bingzi

    2015-10-01

    The role of photodegradation, an abiotic process, has been largely overlooked during straw decomposition in mesic ecosystems. We investigated the mass loss and chemical structures of straw decomposition in response to elevated UV-B radiation with or without soil contact over a 12-month litterbag experiment. Wheat and maize straw samples with and without soil contact were exposed to three radiation levels: a no-sunlight control, ambient solar UV-B, and artificially elevated UV-B radiation. A block control with soil contact was not included. Compared with the no-sunlight control, UV-B radiation increased the mass loss by 14-19% and the ambient radiation by 9-16% for wheat and maize straws without soil contact after 12 months. Elevated UV-B exposure decreased the decomposition rates of both wheat and maize straws when in contact with soil. Light exposure resulted in decreased O-alkyl carbons and increased alkyl carbons for both the wheat and maize straws compared with no-sunlight control. The difference in soil contact may influence the contribution of photodegradation to the overall straw decomposition process. These results indicate that we must take into account the effects of photodegradation when explaining the mechanisms of straw decomposition in mesic ecosystems.

  14. Kinetics of radiation-induced structural alterations in electron-irradiated polymer-based composites

    International Nuclear Information System (INIS)

    Zaikin, Yu.A.; Potanin, A.S.; Koztaeva, U.P.

    2002-01-01

    Complete text of publication follows. In our previous studies measurements of internal friction temperature dependence were used for characterization of thermally activated and radiation-induced structural evolution in different types of polymer-based composites. This paper supplements these measurements with kinetic studies of internal friction (IF) parameters and EPR signals in a glass-cloth epoxy-filled laminate ST-ETF after electron irradiation up to doses of 1-10 MGy. Experiment have shown that the lifetime of free radicals in this composite considerably exceeds the characteristic time of molecular structural rearrangement due to scission and cross-linking after irradiation, as determined from IF measurements. This result is explained by slow proceeding of sterically hindered disproportionation reactions that stabilize the end groups of the macro-chain disrupt during irradiation and finally fix the act of scission. A mathematical model is formulated for description of structural evolution and alterations of IF parameters in polymer-based composites during and after electron irradiation. The description is based on the track model of radiation damage in polymers and phenomenological theory of radiation-induced structural transformations. General description does not give details of radiation-chemical conversion in different structural components of composites but indicates the direction of their structural evolution. In the model considered a composite material was divided into three parts (binder, filler, and a boundary layer). It was supposed that after primary distribution of radiation energy radiation-chemical conversion proceeds independently in each of these regions. It was also suggested that all the radical reactions were of the second order. On the example of glass-cloth laminate ST-ETF it is shown that this model allows to describe alterations in composite structural characteristics during irradiation and in the course of their self-organization after

  15. Peculiarities of electronic structure of silicon-on-insulator structures and their interaction with synchrotron radiation

    Directory of Open Access Journals (Sweden)

    Vladimir A. Terekhov

    2015-09-01

    Full Text Available SOI (silicon-on-insulator structures with strained and unstrained silicon layers were studied by ultrasoft X-ray emission spectroscopy and X-ray absorption near edge structure spectroscopy with the use of synchrotron radiation techniques. Analysis of X-ray data has shown a noticeable transformation of the electron energy spectrum and local partial density of states distribution in valence and conduction bands in the strained silicon layer of the SOI structure. USXES Si L2,3 spectra analysis revealed a decrease of the distance between the L2v′ и L1v points in the valence band of the strained silicon layer as well as a shift of the first two maxima of the XANES first derivation spectra to the higher energies with respect to conduction band bottom Ec. At the same time the X-ray standing waves of synchrotron radiation (λ~12–20 nm are formed in the silicon-on-insulator structure with and without strains of the silicon layer. Moreover changing the synchrotron radiation grazing angle θ by 2° leads to a change of the electromagnetic field phase to the opposite.

  16. The Finnish customs to introduce more efficient radiation control

    International Nuclear Information System (INIS)

    Sevon, H.

    1995-01-01

    The customs authorities have started to control the import of radioactive substances and nuclear materials. Regular radiation measurements will be introduced at various frontier crossing points. Cooperation with the Finnish Centre for Radiation and Nuclear Safety has also been intensified. The control measures apply primarily to goods traffic coming from - or through - Russia and the Baltic countries. The first stationary radiation measuring equipment for vehicles and their loads is in use at Vaalimaa customs station. All the busiest customs stations on Finland's eastern frontier will be provided with stationary radiation meters. The measurements will focus on scrap metal loads and loads that come either from the environs of certain nuclear facilities in the area of former Soviet Union or from areas that are particularly polluted. (orig.) (2 figs.)

  17. Radiation-induced structural transitions in composite materials with strong interaction of polymer components

    International Nuclear Information System (INIS)

    Zaikin, Yu.A.; Koztaeva, U.P.

    2002-01-01

    characteristic feature of the measured IF spectra is a point in the temperature scale (about 150-170 deg. C) where all the curves of IF temperature dependencies for different irradiation doses intersect. IF dose dependence at the temperature lower than the intersection point can be related to radiation-induced structural alterations in the less radiation-resistant structural component and that at the higher temperature characterizes structural state of the high-resistant part of the composite. A special procedure is developed in this paper to separate the 'filler-based' and the 'binder-based' relaxation maximums. Determination of the dose dependence of temperature positions, widths and heights of the two IF peaks, allows to control changes in characteristics of thermally activated glassy transition, mass redistribution and radiation-induced structural alterations in a composite

  18. Control of food-borne molds by combination of heat and radiation

    International Nuclear Information System (INIS)

    Padwal-Desai, S.R.; Bongirwar, D.R.

    1979-01-01

    After enumerating the fungi responsible for food spoilage, work done on the factors influencing growth of fungi in stored foods is reviewed and the methods using heat, radiation or chemicals for control of food-borne molds are briefly surveyed. Work on combination process employing heat treatment and radiation treatment is reviewed in detail. The review covers the following aspects: (1) theory and engineering aspects of combination process of heat and radiation including modes of heat transfer, radiation physics, radiation sources, heat radiation effect and calculation of energy balance of the process, (2) biological effects of heat, radiation and heat-radiation combination treatments on mold growth with special reference to DNA and (3) application of the process for mold control in cereal products, nuts and raisins and fruits. Heat treatment and radiation treatment have been found to complement each other and when given in proper sequence show synergism. Design requirements of radiation sources and heat transfer equipment are also surveyed. (M.G.B.)

  19. Nonlinear-optical generation of short-wavelength radiation controlled by laser-induced interference structures

    International Nuclear Information System (INIS)

    Popov, A K; Kimberg, V V

    1998-01-01

    A study is reported of the combined influence of laser-induced resonances in the energy continuum, of splitting of discrete resonances in the field of several strong radiations, and of absorption of the initial and generated radiations on totally resonant parametric conversion to the short-wavelength range. It is shown that the radiation power can be increased considerably by interference processes involving quantum transitions. (nonlinear optical phenomena and devices)

  20. Radiation control through licensing and intensive training

    International Nuclear Information System (INIS)

    Cheng, C.-H.; Yang, Y.-C.; Wu, T.-Y.; Weng, P.-S.

    1982-01-01

    Various types of intensive training courses to suit radiation workers in different fields were sponsored by both the Atomic Energy Council of Executive Yuan and the National Health Administration of Executive Yuan, Republic of China during the past seven years. During the years 1974-79, the number of radiation workers attending each training course, their age, sex and educational background are presented in detail. The typical course contents for both medical and non-medical radiation workers are given. A summary of the percentage of passes and failures of the final examination given at the end of each training course is also given. The present status of licensing for radiation facilities and workers is described, and its results are indicated. The successful control of ionizing radiation through this kind of intensive training and licensing is evidenced in the film badge records given by a centralized service laboratory located at the National Tsing Hua University. (author)

  1. The international atom: evolution of radiation control programs.

    Science.gov (United States)

    Bradley, F J

    2002-07-01

    Under the Atoms for Peace program, Turkey received a one MWt swimming pool reactor in 1962 that initiated a health physics program for the reactor and a Radiation Control Program (RCP) for the country's use of ionizing radiation. Today, over 13,000 radiation workers, concentrated in the medical field, provide improved medical care with 6,200 x-ray units, including 494 CAT scanners, 222 radioimmunoassay (RIA) labs and 42 radiotherapy centers. Industry has a large stake in the safe use of ionizing radiation with over 1,200 x-ray and gamma radiography and fluoroscopic units, 2,500 gauges in automated process control and five irradiators. A 48-person RCP staff oversees this expanded radiation use. One incident involving a spent 3.3 TBq (88 Ci) 60Co source resulted in 10 overexposures but no fatalities. Taiwan received a 1.6 MWt swimming pool reactor in 1961 and rapidly applied nuclear technology to the medical and industrial fields. Today, there are approximately 24,000 licensed radiation workers in nuclear power field, industry, medicine and academia. Four BWRs and two PWRs supply about 25% of the island's electrical power needs. One traumatic event galvanized the RCP when an undetermined amount of 60Co was accidentally incorporated into reinforcing bars, which in turn were incorporated into residential and commercial buildings. Public exposures were estimated to range up to 15 mSv (1.3 rem) per annum. There were no reported ill effects, except possibly psychological, to date. The RCP now has instituted stringent control measures to ensure radiation-free dwellings and work places. Albania's RCP is described as it evolved since 1972. Regulations were promulgated which followed the IAEA Basic Safety Standards of that era. With 525 licenses and 600 radiation workers, the problem was not in the regulations per se but in their enforcement. The IAEA helped to upgrade the RCP as the economy evolved from one that was centrally planned economy to a free market economy. As this

  2. Regulatory control of ionizing radiations in Ecuador

    International Nuclear Information System (INIS)

    Benitez, Manuel

    1996-03-01

    This document deals with legal aspects for controlling ionizing radiations, radiological safety regulations and objectives, scopes and features of the national radioprotection planning in Ecuador. (The author)

  3. Radiation technique in density and strength testing of coniferous structural timber

    International Nuclear Information System (INIS)

    Dzbenski, W.; Krzosek, S.

    1998-01-01

    The control process of intermediate and final wood products manufacturing is more and more frequently assisted by flow detectors. In radiation devices cesium isotope 137 Cs is replaced by less harmful americium 241 Am. Americium 241 Am was used in the measuring device made in The Academy of Mining and Metallurgy in Cracow. The device was applied in Warsaw Agricultural University (SGGW) in research on Polish structural timber. Negative influence of anatomical defects (knots, compression wood, resinasis, slope of grain, decay) was estimated by gammascopy method. Botanical species (pine, spruce), position in a stem (sapwood, heartwood), anatomical direction (radial, tangential) and moisture content were taken into account. The method of determination a critical place in timber were density is the lowest value (what is an obligatory criterion of stress graded structural timber according to EN standards) was developed. The practical implementation of the method can be reached when sawmills producing structural timber (especially for export) will be more interested in using miniaturized isotope densitometers. (author)

  4. IMRT delivers lower radiation doses to dental structures than 3DRT in head and neck cancer patients.

    Science.gov (United States)

    Fregnani, Eduardo Rodrigues; Parahyba, Cláudia Joffily; Morais-Faria, Karina; Fonseca, Felipe Paiva; Ramos, Pedro Augusto Mendes; de Moraes, Fábio Yone; da Conceição Vasconcelos, Karina Gondim Moutinho; Menegussi, Gisela; Santos-Silva, Alan Roger; Brandão, Thais B

    2016-09-07

    Radiotherapy (RT) is frequently used in the treatment of head and neck cancer, but different side-effects are frequently reported, including a higher frequency of radiation-related caries, what may be consequence of direct radiation to dental tissue. The intensity-modulated radiotherapy (IMRT) was developed to improve tumor control and decrease patient's morbidity by delivering radiation beams only to tumor shapes and sparing normal tissue. However, teeth are usually not included in IMRT plannings and the real efficacy of IMRT in the dental context has not been addressed. Therefore, the aim of this study is to assess whether IMRT delivers lower radiation doses to dental structures than conformal 3D radiotherapy (3DRT). Radiation dose delivery to dental structures of 80 patients treated for head and neck cancers (oral cavity, tongue, nasopharynx and oropharynx) with IMRT (40 patients) and 3DRT (40 patients) were assessed by individually contouring tooth crowns on patients' treatment plans. Clinicopathological data were retrieved from patients' medical files. The average dose of radiation to teeth delivered by IMRT was significantly lower than with 3DRT (p = 0.007); however, only patients affected by nasopharynx and oral cavity cancers demonstrated significantly lower doses with IMRT (p = 0.012 and p = 0.011, respectively). Molars received more radiation with both 3DRT and IMRT, but the latter delivered significantly lower radiation in this group of teeth (p dental groups. Maxillary teeth received lower doses than mandibular teeth, but only IMRT delivered significantly lower doses (p = 0.011 and p = 0.003). Ipsilateral teeth received higher doses than contralateral teeth with both techniques and IMRT delivered significantly lower radiation than 3DRT for contralateral dental structures (p radiation doses to teeth than 3DRT, but only for some groups of patients and teeth, suggesting that this decrease was more likely due to the protection of

  5. Chemical structure and physical properties of radiation-induced crosslinking of polytetrafluoroethylene

    International Nuclear Information System (INIS)

    Oshima, Akihiro; Ikeda, Shigetoshi; Katoh, Etsuko; Tabata, Yoneho

    2001-01-01

    The chemical structure and physical properties of polytetrafluoroethylene (PTFE) that has been crosslinked by radiation have been studied by various methods. It has been found that a Y-type crosslinking structure and a Y-type structure incorporating a double bond (modified Y-type) is formed in PTFE by radiation-crosslinking in the molten state. In addition, various types of double bond structures, excluding the crosslinking site, have been identified. The crosslinked PTFE has a good light transparency due to the loss of crystallites, whilst it retains the excellent properties of electrical insulation and heat resistance. The coefficient of abrasion and the permanent creep are also greatly improved by crosslinking

  6. Regulatory control for safe usage of radiation sources in India

    International Nuclear Information System (INIS)

    Ghosh, P.K.; Sonawane, A.U.

    1998-01-01

    The widespread applications of radioactive materials and radiation generating equipment in the field of industry, medicine agriculture and research in India necessitated the establishment of an efficient regulatory framework and consequently the Atomic Energy Regulatory Board (AERB) was constituted to exercise regulatory control over the safe usage of the radioactive materials and the radiation generating equipment. The Atomic Energy Act, 1962 and the Radiation Protection Rules, 1971 promulgated under the Act forms the basis of radiation safety in India and Chairman, AERB is the Competent Authority to enforce the regulatory provisions of the Radiation Protection Rules, 1971, for safe use of radiation source in the country. AERB has published a number of documents such as Radiation Surveillance Procedures, Standards, Codes, Guides and Manuals for safe use and handling of radioactive materials and radiation generating equipment. Apart from nuclear fuel cycle documents, these publications pertain to industrial radiography, medical application of radiation, transport of radioactive material, industrial gamma irradiators, X-ray units etc. AERB safety related publications are based on international standards e.g. BSS, IAEA, ICRP, ISO etc. This paper outlines the methodology of regulatory control exercised by AERB for safe use of the radioactive materials and the radiation generating equipment in the country. (author)

  7. Dosimetry and control of radiation processing

    International Nuclear Information System (INIS)

    1988-01-01

    Eight invited papers on the general theme of 'Dosimetry and Control of Radiation Processing', presented at a one day symposium held at the National Physical Laboratory, are collected together in this document. Seven of the papers are selected and indexed separately. (author)

  8. Report of questionnaire result concerning the radiation control in medicare facilities

    International Nuclear Information System (INIS)

    Nakamura, Yutaka

    2009-01-01

    Radiation control in Japanese medicare facilities is regulated generally by multiple laws of radiation and the Committee has investigated their actual radiation control practice through questionnaire, of which result and its analysis are described here. The questionnaire on web (Committee's homepage) was conducted in the period Apr., 13-May, 1, 2009, by asking to medical radiology personnel (MRP) with 20 items, mainly about personnel working for radiation medicare (RM), monitoring of their external dose, notice of exposure dose to individual person, archiving of the dose record, and questions about the Law Concerning Prevention from Radiation Hazard due to Radioisotopes, Etc.; was answered by 378 facilities where 15,281 persons in total worked for RM (41/facility in average); and the facilities were under regulation by 1 (Medical, 39%) and 2 (Medical and for Prevention, 61%) laws. Major findings were: 71% of facilities had no clear rule to select MRP; 98% trusted dosimetry outside; in 76%, personnel participating in RM had pocket dosimeter as well; 70% investigated the exposure history at personnel employment; to personnel whose dose could exceed or exceeded 20 mSv/y, 45% transferred the person to other work site, 34% issued warning and 21% had no such personnel; 73% felt the necessity of qualified expert for radiation control; 81% conducted education and training to MRP; 54% used radiation-generating equipments, 27%, unsealed radioisotopes and 19%, sealed ones; and 77% felt the radiation control should be unified in the Medical Law. Based on the findings, the Committee discussed and commented about definition and selection of MRP, dosimetry and its record of MRP having multiple, increasing works, uncertainty of the exact number of MRP in Japan, and desirable unification of radiation control practice in the medicare facility into the Medical Law if amended in future. (K.T.)

  9. The regulatory control of ionizing radiation sources in Lithuania

    International Nuclear Information System (INIS)

    Mastauskas, A.; Ziliukas, J.; Morkunas, G.

    1998-01-01

    The Radiation Protection Centre of the Ministry of Health is the regulatory authority responsible for radiation protection of the public and of workers using sources of ionizing radiation in Lithuania. One of its responsibilities is the control of radioactive sources, which includes keeping the registry, investigating persons arrested while illegally carrying or in possession of radioactive material, decision making and control of users of radioactive sources. The computer based registry contains a directory of more than 24,000 sources and some 800 users in research, medicine and industry. Most of these sources are found in smoke detectors and X ray equipment. The potentially most dangerous sources for therapy and industry (sealed and unsealed) are also listed in this registry. Problems connected with the regulatory control of radioactive sources in Lithuania are presented and their solution is discussed. (author)

  10. Regulatory control of radiation sources in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Daroy, Rosita R

    1996-12-31

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI`s regulatory functions are presented. (author). Paper presented during the IAEA Regional (RCA) Workshop on System of Notification, Registration, Licensing, and Control of Radiation Sources and Installations, Jakarta, Indonesia, 24-28 April 1995. 6 refs., 2 figs., 12 tabs.

  11. Collagen Structural Hierarchy and Susceptibility to Degradation by Ultraviolet Radiation.

    Science.gov (United States)

    Rabotyagova, Olena S; Cebe, Peggy; Kaplan, David L

    2008-12-01

    Collagen type I is the most abundant extracellular matrix protein in the human body, providing the basis for tissue structure and directing cellular functions. Collagen has complex structural hierarchy, organized at different length scales, including the characteristic triple helical feature. In the present study, the relationship between collagen structure (native vs. denatured) and sensitivity to UV radiation was assessed, with a focus on changes in primary structure, changes in conformation, microstructure and material properties. A brief review of free radical reactions involved in collagen degradation is also provided as a mechanistic basis for the changes observed in the study. Structural and functional changes in the collagens were related to the initial conformation (native vs. denatured) and the energy of irradiation. These changes were tracked using SDS-PAGE to assess molecular weight, Fourier transform infrared (FTIR) spectroscopy to study changes in the secondary structure, and atomic force microscopy (AFM) to characterize changes in mechanical properties. The results correlate differences in sensitivity to irradiation with initial collagen structural state: collagen in native conformation vs. heat-treated (denatured) collagen. Changes in collagen were found at all levels of the hierarchical structural organization. In general, the native collagen triple helix is most sensitive to UV-254nm radiation. The triple helix delays single chain degradation. The loss of the triple helix in collagen is accompanied by hydrogen abstraction through free radical mechanisms. The results received suggest that the effects of electromagnetic radiation on biologically relevant extracellular matrices (collagen in the present study) are important to assess in the context of the state of collagen structure. The results have implications in tissue remodeling, wound repair and disease progression.

  12. Long term control of a maxillary sinus mucoepidermoid carcinoma with low dose radiation therapy: a case report

    International Nuclear Information System (INIS)

    Vulpe, Horia; Giuliani, Meredith; Goldstein, David; Perez-Ordonez, Bayardo; Dawson, Laura A; Hope, Andrew

    2013-01-01

    Mucoepidermoid carcinoma of the maxillary sinus is a rare malignancy of the head and neck. The location of this tumour near vital structures and its large size at presentation makes surgical resection with negative margins challenging. In incurable cases, relief from symptoms such as epistaxis may be achieved with radiation therapy. We present a case of mucoepidermoid carcinoma of the maxillary sinus that was effectively palliated with a short course of radiation therapy, achieving complete cessation of bleeding, decrease in tumour size, and long term control. We surveyed the literature on mucoepidermoid carcinomas and propose that some tumours may be particularly radiosensitive, benefiting from even short courses of radiation therapy

  13. Sequential probability ratio controllers for safeguards radiation monitors

    International Nuclear Information System (INIS)

    Fehlau, P.E.; Coop, K.L.; Nixon, K.V.

    1984-01-01

    Sequential hypothesis tests applied to nuclear safeguards accounting methods make the methods more sensitive to detecting diversion. The sequential tests also improve transient signal detection in safeguards radiation monitors. This paper describes three microprocessor control units with sequential probability-ratio tests for detecting transient increases in radiation intensity. The control units are designed for three specific applications: low-intensity monitoring with Poisson probability ratios, higher intensity gamma-ray monitoring where fixed counting intervals are shortened by sequential testing, and monitoring moving traffic where the sequential technique responds to variable-duration signals. The fixed-interval controller shortens a customary 50-s monitoring time to an average of 18 s, making the monitoring delay less bothersome. The controller for monitoring moving vehicles benefits from the sequential technique by maintaining more than half its sensitivity when the normal passage speed doubles

  14. External radiation exposure control system in accelerator facilities

    International Nuclear Information System (INIS)

    Ogawa, Tatsuhiko; Iimoto, Takeshi; Kosako, Toshiso

    2011-01-01

    The external exposure control systems in KEK and CERN are discussed to find out good practices and unreasonableness of radiation control in accelerator facilities, which plays an important role in optimizing national and/or site specific radiological regulations, referring to relevant ICRP publications. Personal dose limits and radiation area classifications were analyzed and their reasonableness were explored. Good example of supervised areas, area classification based on realistic assumptions on working time etc are found. On the other hand, unreasonable systems, that are often attributed to the national regulation or ideas presented in the old publications are also found. (author)

  15. Tumor control probability after a radiation of animal tumors

    International Nuclear Information System (INIS)

    Urano, Muneyasu; Ando, Koichi; Koike, Sachiko; Nesumi, Naofumi

    1975-01-01

    Tumor control and regrowth probability of animal tumors irradiated with a single x-ray dose were determined, using a spontaneous C3H mouse mammary carcinoma. Cellular radiation sensitivity of tumor cells and tumor control probability of the tumor were examined by the TD 50 and TCD 50 assays respectively. Tumor growth kinetics were measured by counting the percentage of labelled mitosis and by measuring the growth curve. A mathematical analysis of tumor control probability was made from these results. A formula proposed, accounted for cell population kinetics or division probability model, cell sensitivity to radiation and number of tumor cells. (auth.)

  16. Current status of the radiation technology and quality control for radiation processing in Latin America

    International Nuclear Information System (INIS)

    Miranda, Enrique Francisco Prietro

    2013-01-01

    The use of the radiation technology has gained acceptance in various regions of the world, where studies estimated that the installed capacity increases at a rate of 6 % per year and Latin America is part of this increase, due the advantages of this process when it is employed for the food preservation, sterilization of medical pharmaceutical material and to control the insect pests. This paper shows the art state of the application of Radiation Technology in Latin America, as well as the technological characteristics of the most gamma irradiation facilities and minor number the electron beam accelerator facilities, the types of irradiated products, state of the Quality Management System and the Dosimetric Systems used in the Radiation Processing Control in the Region. (author)

  17. Track structure theory in radiobiology and in radiation detection

    International Nuclear Information System (INIS)

    Katz, R.

    1976-01-01

    The response of biological cells, and many physical radiation and track detectors to ionizing radiations, and to energetic heavily ionizing particles results from the secondary and higher generation electrons ejected from the atoms and molecules of the detector by the incident primary radiation. The models which have been used for detector response arise from target theory, and are of the form of statistical models called multi-hit or multi-target detectors, in which it is assumed that there are sensitive elements (emulsion grains, or biological cell nuclei) which may require many hits (emulsion grains) or single hits in different targets (say, cellular chromosomes) in order to produce the observed endpoint. Physically, a hit is interpreted as a 'registered event' caused by an electron passing through the sensitive site, with an efficiency which depends on the electron's speed. Some knowledge of size of the sensitive volume and of the sensitive target is required to make the transition from gamma-ray response to heavy ion response. Recent work has demonstrated that many-hit physical detectors do exist. From both emulsion sensitometry and from the structure of tracks of heavy ions, we are able to show that emulsion-developer combinations exist which yield many-hit response. There is also some evidence that the supralinearity in thermoluminescent dosimeters arises from a trap structures within the same TLD crystal. These detectors can be expected to mimic the response of biological cells to radiations of different quality. Their patterns of response may help us to understand better the structure of particle tracks in SSNTD's. (orig./ORU) [de

  18. Internal Roof and Attic Thermal Radiation Control Retrofit Strategies for Cooling-Dominated Climates

    Energy Technology Data Exchange (ETDEWEB)

    Fallahi, A. [Fraunhofer Center for Sustainable Energy Systems, Boston, MA (United States); Duraschlag, H. [Fraunhofer Center for Sustainable Energy Systems, Boston, MA (United States); Elliott, D. [Fraunhofer Center for Sustainable Energy Systems, Boston, MA (United States); Hartsough, J. [Fraunhofer Center for Sustainable Energy Systems, Boston, MA (United States); Shukla, N. [Fraunhofer Center for Sustainable Energy Systems, Boston, MA (United States); Kosny, J. [Fraunhofer Center for Sustainable Energy Systems, Boston, MA (United States)

    2013-12-01

    This project evaluates the cooling energy savings and cost effectiveness of radiation control retrofit strategies for residential attics in U.S. cooling-dominated climates. Usually, in residential applications, radiation control retrofit strategies are applied below the roof deck or on top of the attic floor insulation. They offer an alternative option to the addition of conventional bulk insulation such as fiberglass or cellulose insulation. Radiation control is a potentially low-cost energy efficiency retrofit strategy that does not require significant changes to existing homes. In this project, two groups of low-cost radiation control strategies were evaluated for southern U.S. applications. One uses a radiant barrier composed of two aluminum foils combined with an enclosed reflective air space and the second uses spray-applied interior radiation control coatings (IRCC).

  19. Internal Roof and Attic Thermal Radiation Control Retrofit Strategies for Cooling-Dominated Climates

    Energy Technology Data Exchange (ETDEWEB)

    Fallahi, A. [Fraunhofer Center for Sustainable Energy Systems (CSE), Boston, MA (United States); Durschlag, H. [Fraunhofer Center for Sustainable Energy Systems (CSE), Boston, MA (United States); Elliott, D. [Fraunhofer Center for Sustainable Energy Systems (CSE), Boston, MA (United States); Hartsough, J. [Fraunhofer Center for Sustainable Energy Systems (CSE), Boston, MA (United States); Shukla, N. [Fraunhofer Center for Sustainable Energy Systems (CSE), Boston, MA (United States); Kosny, J. [Fraunhofer Center for Sustainable Energy Systems (CSE), Boston, MA (United States)

    2013-12-01

    This project evaluates the cooling energy savings and cost effectiveness of radiation control retrofit strategies for residential attics in U.S. cooling-dominated climates. Usually, in residential applications, radiation control retrofit strategies are applied below the roof deck or on top of the attic floor insulation. They offer an alternative option to the addition of conventional bulkinsulation such as fiberglass or cellulose insulation. Radiation control is a potentially low-cost energy efficiency retrofit strategy that does not require significant changes to existing homes. In this project, two groups of low-cost radiation control strategies were evaluated for southern U.S. applications. One uses a radiant barrier composed of two aluminum foils combined with an enclosedreflective air space and the second uses spray-applied interior radiation control coatings (IRCC).

  20. Experimental evaluation of radiator control based on primary supply temperature for district heating substations

    International Nuclear Information System (INIS)

    Gustafsson, Jonas; Delsing, Jerker; Deventer, Jan van

    2011-01-01

    Highlights: → We compared a new radiator system control approach with traditional control. → This is an experimental verification of previous simulation results. → We examine changes in delta-T and indoor comfort. → The indoor comfort were not affected by the introduction of alt. radiator control. → The alternative control method can contribute to an increased delta-T. -- Abstract: In this paper, we evaluate whether the primary supply temperature in district heating networks can be used to control radiator systems in buildings connected to district heating; with the purpose of increasing the ΔT. The primary supply temperature in district heating systems can mostly be described as a function of outdoor temperature; similarly, the radiator supply temperature in houses, offices and industries can also be described as a function of outdoor temperature. To calibrate the radiator control system to produce an ideally optimal radiator supply temperature that produces a maximized ΔT across the substation, the relationship between the primary supply temperature and outdoor temperature must be known. However, even if the relation is known there is always a deviation between the expected primary supply temperature and the actual temperature of the received distribution media. This deviation makes the radiator control system incapable of controlling the radiator supply temperature to a point that would generate a maximized ΔT. Published simulation results show that it is possible and advantageous to utilize the primary supply temperature for radiator system control. In this paper, the simulation results are experimentally verified through implementation of the control method in a real district heating substation. The primary supply temperature is measured by the heat-meter and is shared with the radiator control system; thus no additional temperature sensors were needed to perform the experiments. However additional meters were installed for surveillance purposes

  1. Radiative sky cooling: fundamental physics, materials, structures, and applications

    Science.gov (United States)

    Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang; Alam, Muhammad Ashraful; Bermel, Peter

    2017-07-01

    Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, such as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.

  2. Structure analysis of biomolecules using synchrotron radiation circular dichroism spectrophotometer

    International Nuclear Information System (INIS)

    Gekko, Kunihiko; Matsuo, Koichi

    2004-01-01

    We constructed the vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer, which is capable of measuring circular dichroism spectra to 140 nm for aqueous solutions at temperature from -30 to 70degC, using a small-scale SR source at Hiroshima Synchrotron Radiation Center (HiSOR). This spectrophotometer was used for structural analyses of amino acids, saccharides, and proteins in water. The obtained results demonstrate that a synchrotron radiation VUVCD spectroscopy provides more detailed and new information on the structures of biomolecules, based on the high energy transitions of chromophores such as hydroxyl, acetal, and peptide groups. (author)

  3. Adjuvant radiation for vulvar carcinoma: improved local control

    International Nuclear Information System (INIS)

    Faul, Clare M.; Mirmow, Dwight; Huang Qingshon; Gerszten, Kristina; Day, Roger; Jones, Mirka W.

    1997-01-01

    Purpose: Local recurrence is a significant problem following primary surgery for advanced vulva carcinoma. The objectives of this study were to evaluate the impact of adjuvant vulvar radiation on local control in high risk patients and the impact of local recurrence on overall survival. Methods and Materials: From 1980-1994, 62 patients with invasive vulva carcinoma and either positive or close (less 8 mm) margins of excision were retrospectively studied. Thirty-one patients were treated with adjuvant radiation therapy to the vulva and 31 patients were observed after surgery. Kaplan-Meier estimates and the Cox proportional hazard regression model were used to evaluate the effect of adjuvant radiation therapy on local recurrence and overall survival. Independent prognostic factors for local recurrence and survival were also assessed. Results: Local recurrence occurred in 58% of observed patients and 16% in patients treated with adjuvant radiation therapy. Adjuvant radiation therapy significantly reduced local recurrence rates in both the close margin and positive margin groups (p = 0.036, p = 0.0048). On both univariate and multivariate analysis adjuvant radiation and margins of excision were significant prognostic predictors for local control. Significant determinants of actuarial survival included International Federation of Gynecologists and Obstetricians (FIGO) stage, percentage of pathologically positive inguinal nodes and margins of excision. The positive margin observed group had a significantly poorer actuarial 5 year survival than the other groups (p = 0.0016) and adjuvant radiation significantly improved survival for this group. The 2 year actuarial survival after developing local recurrence was 25%. Local recurrence was a significant predictor for death from vulva carcinoma (risk ratio 3.54). Conclusion: Local recurrence is a common occurrence in high risk patients. In this study adjuvant radiation therapy significantly reduced local recurrence rates and

  4. Radiation field control at the latest BWR plants -- design principle, operational experience and future subjects

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Shunsuke [Energy Research Lab., Ibaraki (Japan); Ohsumi, Katsumi; Takashima, Yoshie [Hitachi Works, Ibaraki (Japan)

    1995-03-01

    Improvements of operational procedures to control water chemistry, e.g., nickel/iron control, as well as application of hardware improvements for reducing radioactive corrosion products resulted in an extremely low occupational exposure of less than 0.5 man.Sv/yr without any serious impact on the radwaste system, for BWR plants involved in the Japanese Improvement and Standardization Program. Recently, {sup 60}C radioactively in the reactor water has been increasing due to less crud fixation on the two smooth surfaces of new type high performance fuels and to the pH drop caused by chromium oxide anions released from stainless steel structures and pipings. This increase must be limited by changes in water chemistry, e.g., applications of modified nickel/iron ratio control and weak alkali control. Controlled water chemistry to optimize three points, the plant radiation level and integrities of fuel and structural materials, is the primary future subject for BWR water chemistry.

  5. Recent Advances in Heliogyro Solar Sail Structural Dynamics, Stability, and Control Research

    Science.gov (United States)

    Wilkie, W. Keats; Warren, Jerry E.; Horta, Lucas G.; Lyle, Karen H.; Juang, Jer-Nan; Gibbs, S. Chad; Dowell, Earl H.; Guerrant, Daniel V.; Lawrence, Dale

    2015-01-01

    Results from recent NASA sponsored research on the structural dynamics, stability, and control characteristics of heliogyro solar sails are summarized. Specific areas under investigation include coupled nonlinear finite element analysis of heliogyro membrane blade with solar radiation pressure effects, system identification of spinning membrane structures, and solarelastic stability analysis of heliogyro solar sails, including stability during blade deployment. Recent results from terrestrial 1-g blade dynamics and control experiments on "rope ladder" membrane blade analogs, and small-scale in vacuo system identification experiments with hanging and spinning high-aspect ratio membranes will also be presented. A low-cost, rideshare payload heliogyro technology demonstration mission concept is used as a mission context for these heliogyro structural dynamics and solarelasticity investigations, and is also described. Blade torsional dynamic response and control are also shown to be significantly improved through the use of edge stiffening structural features or inclusion of modest tip masses to increase centrifugal stiffening of the blade structure. An output-only system identification procedure suitable for on-orbit blade dynamics investigations is also developed and validated using ground tests of spinning sub-scale heliogyro blade models. Overall, analytical and experimental investigations to date indicate no intractable stability or control issues for the heliogyro solar sail concept.

  6. Effectiveness of topical steroids in the control of radiation dermatitis

    International Nuclear Information System (INIS)

    Glees, J.P.; Mameghan-Zadeh, H.; Sparkes, C.G.

    1979-01-01

    Radiation dermatitis often presents as a problem for patients and radiotherapists during treatment. Topical corticosteroids have been shown to have an anti-inflammatory effect in the treatment of many skin diseases and are commonly prescribed during a course of radiation treatment. A comparison of two different steroid creams, 1% hydrocortisone cream and 0.05% clobetasone butyrate (Eumovate), in a double blind trial was carried out in 54 patients undergoing radiation therapy for breast cancer. 'The cream' was administered when patients reached a given dose of 2000 rad (or earlier if required) whether a skin reaction was present or not. The aim of the trial was to evaluate the general effectiveness of steroids in controlling radiation dermatitis and whether one type of cream was superior to the other. The majority of patients using either cream derived benefit in its soothing effect. There was, however, a significant difference in the intensity of reactions seen, patients using clobetasone butyrate developed more severe radiation reactions despite both groups having similar radiation doses. The possibility of two differing populations having different responses to radiation is discussed as is the 'breakthrough phenomenon' described in the literature. It is concluded that neither cream should be used as first choice in the control of radiation dermatitis. (author)

  7. Radiation control report on intermediate heat exchanger replacement and related works

    International Nuclear Information System (INIS)

    Kanou, Y.; Yamanaka, T.; Sasajima, T.; Hoshiba, H.; Emori, S.; Shindou, K.

    2002-03-01

    The 13th periodical inspection of the experimental fast reactor JOYO is being made from Jun. 2000 to Jan. 2003. While this inspection, from the end of Oct. 2000 to Nov. 2001, the MK-III modification work on heat transport system was made in lower region of the reactor containment vessel in the reactor facility (under floor area). In the MK-III modification work, the works important to radiation control were the replacement of intermediate heat exchangers (IHXs) and fixtures, and the picking out of the surveillance material from primary heat transport piping carried out in the maintenance building. Because the working areas of these works were executed in small space around the complicated primary heat transport piping, workability was bad and dose rate from the corrosion products (CP) in piping or fixtures was high. In such condition, radiation control was performed mainly concerned about external exposure. The planted total external exposure of the IHX replacement and related works was 7135 man-mSv (target of total dose control: less than 5708 man-mSv, 80% of the plan), derived from special radiation work plants for segmental works, concerned about work procedure, number of workers, period of work, dose rate of working area and surface dose rate of equipments. The special radiation control organization was established for such long and large-scale work. The spatial organization held detailed discussion about radiation control of this work with the execution section and contractors appropriately, performance careful external/internal exposure control and surface contamination control and made efforts to reduce te external exposure thoroughly. As a result of these action, the total external exposure was 2386 man·mSv (≅33% of the plan, ≅42% of the target) and the maximum individual exposure were 24.7 mSv for staffs and 21.7mSv for contractors. The dose rate, surface contamination and air contamination while the works were kept under the control level with the

  8. Factors controlling high-frequency radiation from extended ruptures

    Science.gov (United States)

    Beresnev, Igor A.

    2017-09-01

    Small-scale slip heterogeneity or variations in rupture velocity on the fault plane are often invoked to explain the high-frequency radiation from earthquakes. This view has no theoretical basis, which follows, for example, from the representation integral of elasticity, an exact solution for the radiated wave field. The Fourier transform, applied to the integral, shows that the seismic spectrum is fully controlled by that of the source time function, while the distribution of final slip and rupture acceleration/deceleration only contribute to directivity. This inference is corroborated by the precise numerical computation of the full radiated field from the representation integral. We compare calculated radiation from four finite-fault models: (1) uniform slip function with low slip velocity, (2) slip function spatially modulated by a sinusoidal function, (3) slip function spatially modulated by a sinusoidal function with random roughness added, and (4) uniform slip function with high slip velocity. The addition of "asperities," both regular and irregular, does not cause any systematic increase in the spectral level of high-frequency radiation, except for the creation of maxima due to constructive interference. On the other hand, an increase in the maximum rate of slip on the fault leads to highly amplified high frequencies, in accordance with the prediction on the basis of a simple point-source treatment of the fault. Hence, computations show that the temporal rate of slip, not the spatial heterogeneity on faults, is the predominant factor forming the high-frequency radiation and thus controlling the velocity and acceleration of the resulting ground motions.

  9. Licensing authority's control of radiation sources and nuclear materials in Brazil

    International Nuclear Information System (INIS)

    Binns, D.A.C.

    2002-01-01

    Full text: The Brazilian Nuclear Energy Commission is the national licensing authority and among its responsibilities is the control of nuclear materials and radiation sources. This control is carried out in three different ways: 1) Control of the import and export of nuclear materials and radiation sources. To be able to import or export any nuclear material or radiation source, the user has to have an explicit permission of the licensing authority. This is controlled by electronic means in which the user has to fill a special form found on the licensing authority's home page, where he has to fill in his name, license number, license number of his radiation protection officer and data of the material to be imported or exported. These data are checked with a data base that contains all the information of the licensed users and qualified personnel before authorization is emitted. The airport authorities have already installed x-ray machines to check all baggages entering or leaving the country. 2) Transport and transfer permit for radiation sources. In order to transport and/or transfer radiations sources and nuclear materials within the country, the user(s) have to submit an application to the licensing authority. The user(s) fill out an application form where he fills in his company's name, licensing I.D., radiation protection officer's name and I.D and identification of the sources involved. These information are checked with the licensing operations data before the operations is permitted. 3) Inspections and radiation monitoring systems. Routine and regulatory inspections are continuously carried out where the user's radiation sources and nuclear materials inventory are checked. Also the physical security and protection of these materials are verified. The installation of monitoring systems is an item that is being discussed with the airport authorities so as to increase the possibilities of detecting any illegal transport of these materials. (author)

  10. Controllable forms of natural background radiation

    International Nuclear Information System (INIS)

    1988-03-01

    RENA is a research programm into the controllable forms of natural background radiation, which cover the activities originating from the naturally occurring radionuclides enhanced by human intervention. In the RENA-program emphasis lays upon the policy aspects of environmental-hygienic, economical and governmental character. (H.W.). 15 refs.; 2 tabs

  11. Electromagnetic radiation and scattering from small canonical structures of double-negative metamaterials

    DEFF Research Database (Denmark)

    Arslanagic, Samel

    2007-01-01

    aspects associated with DNG materials, and was subsequently extended to investigations of the radiation and scattering from two- and three-dimensional (2D and 3D) MTM-based canonical problems in electromagnetic theory. As to the theoretical aspects of DNG materials, the sign, or more generally the branch......, cylindrical and spherical configurations to design electrically small, resonant structures such as cavities, waveguides, scatterers and radiators. These ideas are extended here to canonical antenna and scattering configurations which consist of electrically small resonant cylindrical and spherical MTM......-based structures excited by an arbitrarily located electric line source and an arbitrarily located and oriented electric Hertzian dipole, respectively. Exact analytical solutions, based on eigenfunction series, are derived and then numerically evaluated to study the radiation and scattering from these structures...

  12. Structural Pain Compensating Flight Control

    Science.gov (United States)

    Miller, Chris J.

    2014-01-01

    The problem of control command and maneuver induced structural loads is an important aspect of any control system design. Designers must design the aircraft structure and the control architecture to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to build the structure with high margins, restrict control surface commands to known good combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage.

  13. Radiative sky cooling: fundamental physics, materials, structures, and applications

    Directory of Open Access Journals (Sweden)

    Sun Xingshu

    2017-07-01

    Full Text Available Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, such as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.

  14. IMRT delivers lower radiation doses to dental structures than 3DRT in head and neck cancer patients

    International Nuclear Information System (INIS)

    Fregnani, Eduardo Rodrigues; Parahyba, Cláudia Joffily; Morais-Faria, Karina; Fonseca, Felipe Paiva; Ramos, Pedro Augusto Mendes; Moraes, Fábio Yone de; Conceição Vasconcelos, Karina Gondim Moutinho da; Menegussi, Gisela; Santos-Silva, Alan Roger; Brandão, Thais B.

    2016-01-01

    Radiotherapy (RT) is frequently used in the treatment of head and neck cancer, but different side-effects are frequently reported, including a higher frequency of radiation-related caries, what may be consequence of direct radiation to dental tissue. The intensity-modulated radiotherapy (IMRT) was developed to improve tumor control and decrease patient’s morbidity by delivering radiation beams only to tumor shapes and sparing normal tissue. However, teeth are usually not included in IMRT plannings and the real efficacy of IMRT in the dental context has not been addressed. Therefore, the aim of this study is to assess whether IMRT delivers lower radiation doses to dental structures than conformal 3D radiotherapy (3DRT). Radiation dose delivery to dental structures of 80 patients treated for head and neck cancers (oral cavity, tongue, nasopharynx and oropharynx) with IMRT (40 patients) and 3DRT (40 patients) were assessed by individually contouring tooth crowns on patients’ treatment plans. Clinicopathological data were retrieved from patients’ medical files. The average dose of radiation to teeth delivered by IMRT was significantly lower than with 3DRT (p = 0.007); however, only patients affected by nasopharynx and oral cavity cancers demonstrated significantly lower doses with IMRT (p = 0.012 and p = 0.011, respectively). Molars received more radiation with both 3DRT and IMRT, but the latter delivered significantly lower radiation in this group of teeth (p < 0.001), whereas no significant difference was found for the other dental groups. Maxillary teeth received lower doses than mandibular teeth, but only IMRT delivered significantly lower doses (p = 0.011 and p = 0.003). Ipsilateral teeth received higher doses than contralateral teeth with both techniques and IMRT delivered significantly lower radiation than 3DRT for contralateral dental structures (p < 0.001). IMRT delivered lower radiation doses to teeth than 3DRT, but only for some groups of patients and

  15. Numerical study of jet noise radiated by turbulent coherent structures

    Energy Technology Data Exchange (ETDEWEB)

    Bastin, F.

    1995-08-01

    a numerical approach of jet mixing noise prediction is presented, based on the assumption that the radiated sound field is essentially due to large-scale coherent turbulent structures. A semi-deterministic turbulence modelling is used to obtain the flow coherent fluctuations. This model is derived from the k-{epsilon} model and validated on the 2-D compressible shear layer case. Three plane jets at Mach 0.5, 1.33 and 2 are calculated. The semi-deterministic modelling yields a realistic unsteady representation of plane jets but not appropriate for axisymmetric jet computations. Lighthill`s analogy is used to estimate the noise radiated by the flow. Three integral formulations of the theory are compared and the most suitable one is expressed in space-time Fourier space. This formulation is associated to a geometrical interpretation of acoustic computations in (k, {omega}) plane. The only contribution of coherent structures cannot account for the high-frequency radiation of a subsonic jet and thus, the initial assumption is not verified in the subsonic range. The interpretation of Lighthill`s analogy in (k, {omega}) plane allows to conclude that the missing high-frequency components are due to the inner structure of the coherent motion. For supersonic jets, full acoustic spectra are obtained, at least in the forward arc where the dominant radiation is emitted. For the fastest jet (M = 2), no Mach waves are observed, which may be explained by a ratio of the structures convection velocity to the jet exit velocity lower in plane than in circular jets. This point is confirmed by instability theory calculations. Large eddy simulations (LES) were performed for subsonic jets. Data obtained in the plane jet case show that this technique allows only a slight improvement of acoustic results. To obtain a satisfactory high-frequency radiation, very fine grids should be considered, and the 2-D approximation could not be justified anymore. (Abstract Truncated)

  16. Remote control and data processing for measurement of radiation dose

    International Nuclear Information System (INIS)

    Zhou Yu; Luo Yisheng; Guo Yong; Ji Gang; Wang Xinggong; Zhang Hong; Zhang Wenzhong

    2004-01-01

    Objective: To protect the workers from the reactor radiation and to improve the accuracy and efficiency of neutron dose measurement. Methods: With the application of remote control technology, a remote control and automatic measurement system for radiation dose measurement(especially for neutron dose) was set up. A Model 6517A electrometer was operated all automatically over RS-232 serial interface using SCPI commands with a computer. Results: The workers could stay far from the reactor and be able to control the portable computer in site though internet or LAN and then to control the 6517A electrometer to implement the dose measurement. After the measurement, the data were transferred to the remote computer near the workers and shared by many experts at the first time through the net. Conclusion: This is the first time that the remote control technology is applied in radiation dose measurement, which has so far been considered can only be performed at a near place. This new system can meet the need of neutron radiobiology researches as well as of the safety and health of the workers. (author)

  17. Self-assemblage and post-radiation recovery of cell supramolecular structures

    International Nuclear Information System (INIS)

    Grodzinskij, D.M.; Kolomiets, K.D.

    1979-01-01

    The role of the molecular equation and self-assemblage in post-radiation chromatin recovery of meristematic cells of pea rootlets is shown. Found are the two repair types at the chromatin level by fractionating of the radiation dose. The first type comprises transient processes including DNA repair, the second type comprises processes including biosynthesis of the chromatin components and proteins, in the first place. The role of protein biosynthesis in the process of recovery of the chromatin supramolecular structure is shown. The improved radiostability of chromatin self-assemblage is characteristic for the level of its subunits. The supramolecular chromatin structure of the other levels has less radiostability

  18. Fishing for radiation quality: chromosome aberrations and the role of radiation track structure

    International Nuclear Information System (INIS)

    Hill, M.A.

    2015-01-01

    The yield of chromosome aberrations is not only dependent on dose but also on radiation quality, with high linear energy transfer (LET) typically having a greater biological effectiveness per unit dose than those of low-LET radiation. Differences in radiation track structure and cell morphology can also lead to quantitative differences in the spectra of the resulting chromosomal rearrangements, especially at low doses associated with typical human exposures. The development of combinatorial fluorescent labelling techniques (such as mFISH and mBAND) has helped to reveal the complexity of rearrangements, showing increasing complexity of observed rearrangements with increasing LET but has a resolution limited to ∼10 MBp. High-LET particles have not only been shown to produce clustered sites of DNA damage but also produce multiple correlated breaks along its path resulting in DNA fragments smaller than the resolution of these techniques. Additionally, studies have shown that the vast majority of radiation-induced HPRT mutations were also not detectable using fluorescent in situ hybridisation (FISH) techniques, with correlation of breaks along the track being reflected in the complexity of mutations, with intra- and inter-chromosomal insertions, and inversions occurring at the sites of some of the deletions. Therefore, the analysis of visible chromosomal rearrangements observed using current FISH techniques is likely to represent just the tip of the iceberg, considerably underestimating the extent and complexity of radiation induced rearrangements. (author)

  19. Monitoring and control of occupational radiation exposure in Switzerland

    International Nuclear Information System (INIS)

    Moser, M.

    1997-01-01

    Occupational exposure is the most prominent example for the prolonged exposure to low level ionizing radiation characterized by low doses and dose rates. In this paper the occupational exposure in Switzerland is presented and the regulatory control of this exposure in the framework of the new radiation protection regulations is discussed. (author)

  20. Comparative evaluation of radiation injuries in skin histological structures under local irradiation

    International Nuclear Information System (INIS)

    Kolchanova, G.M.

    1978-01-01

    In order to evaluate quantitatively to what degree the various histologic structures of the skin undergo changes after a radiation injury and during the reparative process, white rats have been used to study these changes in relation to the radiation dose and the time elapsed after exposure. The rats have been locally exposed on a single occasion to long-wave (10.2 keV) x-radiation in doses of 250, 500, 1000, or 2000 R. Greatest changes in histologic structures occured with doses of 250-1000 R on days 96-115 postexposure. With higher doses, these changes are most clearly marked as early as on day 38

  1. Method and device for controlling radiation

    International Nuclear Information System (INIS)

    Wilhelm, G.M.

    1979-01-01

    A device which will control radiation emanating from colour television sets is described. It consists of two transparent plates the same size as a television screen, with a thin layer of transparent mineral oil sealed between them. The device may be installed by the manufacturer or bought separately and installed by the user. (LL)

  2. The radon daughter radiation hazard in controlled recirculation systems

    International Nuclear Information System (INIS)

    Rolle, R.; Burton, R.C.

    1987-01-01

    In deep South African gold mines, controlled recirculation systems with air cooling are being used to an increasing extent to improve the thermal environment. Recirculation causes some air to reside in the working area for a longer time than would have occurred without recirculation. Since radon daughters grow spontaneously from radon there is some concern that, with the extended residence time, the potential radiation hazard could increase to an unacceptable level. This paper describes the results obtained from a theoretical model of a controlled recirculation system. Guidelines for the design of recirculation systems to control the radon daughter radiation, and to keep it within acceptable limits are provided. 3 refs., 5 figs

  3. Modeling and Fuzzy PDC Control and Its Application to an Oscillatory TLP Structure

    Directory of Open Access Journals (Sweden)

    Cheng-Wu Chen

    2010-01-01

    Full Text Available An analytical solution is derived to describe the wave-induced flow field and surge motion of a deformable platform structure controlled with fuzzy controllers in an oceanic environment. In the controller design procedure, a parallel distributed compensation (PDC scheme is utilized to construct a global fuzzy logic controller by blending all local state feedback controllers. The Lyapunov method is used to carry out stability analysis of a real system structure. The corresponding boundary value problems are then incorporated into scattering and radiation problems. These are analytically solved, based on the separation of variables, to obtain a series of solutions showing the harmonic incident wave motion and surge motion. The dependence of the wave-induced flow field and its resonant frequency on wave characteristics and structural properties including platform width, thickness and mass can thus be drawn with a parametric approach. The wave-induced displacement of the surge motion is determined from these mathematical models. The vibration of the floating structure and mechanical motion caused by the wave force are also discussed analytically based on fuzzy logic theory and the mathematical framework to find the decay in amplitude of the surge motion in the tension leg platform (TLP system. The expected effects of the damping in amplitude of the surge motion due to the control force on the structural response are obvious.

  4. Portable microcomputer controlled radiation counter

    International Nuclear Information System (INIS)

    Mason, E.W.; Weber, J.M.

    1984-01-01

    A portable microcomputer controlled counter for use as a radiation counter is described. The counter uses digital processing of input pulses from a radiation detector. The number of counts received by the microcomputer per unit time is used to calculate a value for display using a calibration factor obtained during physical calibration of the instrument with a radiation source or with a pulse generator. The keyboard is used to enter calibration points. The number of calibration points which may be entered depends on the degree of accuracy desired by the user. The high voltage generator which drives the detector is triggered by pulses from the microcomputer in relation to the count rate. After processing the count, the resulting count rate or dose rate is displayed on the liquid crystal display. The counter is autoranging in which the decimal point is shifted as necessary by the microcomputer. The units displayed are determined by the user by means of a multiposition switch. Low battery and an overrange condition are displayed. An interface is provided via a connector to allow parallel transmission of data to peripheral devices. Low battery power consumption is featured. The counter is capable of providing more accurate readings than currently available counters

  5. Quality control of gamma radiation measuring systems

    International Nuclear Information System (INIS)

    Surma, M.J.

    2002-01-01

    The problem of quality control and assurance of gamma radiation measuring systems has been described in detail. The factors deciding of high quality of radiometric measurements as well as statistical testing and calibration of measuring systems have been presented and discussed

  6. Radiative Transfer Theory Verified by Controlled Laboratory Experiments

    Science.gov (United States)

    Mishchenko, Michael I.; Goldstein, Dennis H.; Chowdhary, Jacek; Lompado, Arthur

    2013-01-01

    We report the results of high-accuracy controlled laboratory measurements of the Stokes reflection matrix for suspensions of submicrometer-sized latex particles in water and compare them with the results of a numerically exact computer solution of the vector radiative transfer equation (VRTE). The quantitative performance of the VRTE is monitored by increasing the volume packing density of the latex particles from 2 to 10. Our results indicate that the VRTE can be applied safely to random particulate media with packing densities up to 2. VRTE results for packing densities of the order of 5 should be taken with caution, whereas the polarized bidirectional reflectivity of suspensions with larger packing densities cannot be accurately predicted. We demonstrate that a simple modification of the phase matrix entering the VRTE based on the so-called static structure factor can be a promising remedy that deserves further examination.

  7. The Japan Power Demonstration Reactor dismantling project. Radiation control

    International Nuclear Information System (INIS)

    Tomii, Hiroyuki; Seiki, Yoshihiro

    1996-01-01

    In the Japan Power Demonstration Reactor (JPDR) dismantling project, radiation control was performed properly with routine and special monitoring to keep the occupational safety and to collect data necessary for future dismantling of nuclear facilities. This report describes a summary of radiation control in the dismantling activities and some results of parametric analysis on dose equivalent evaluation, and introduces the following knowledge on radiological protection effectiveness of the dismantling systems applied in the project. a) Use of remote dismantling systems was effective in reducing equivalent workplace exposure. b) Utilization of existing facilities as radiation shield or radioactivity containment was effective in reducing workplace exposure, and also in increasing work efficiency. c) Use of underwater cutting systems was useful to minimize air contamination, and to reduce the dose equivalent rate in the working area. d) In the planning of dismantling, it is necessary to optimize the radiation protection by analyzing dismantling work procedures and evaluating radiological features of the dismantling systems applied, including additional work which the systems require brought from such activities. (author)

  8. Therapeutic radiation and hyperparathyroidism. A case-control study in Rochester, Minn

    International Nuclear Information System (INIS)

    Beard, C.M.; Heath, H. III; O'Fallon, W.M.; Anderson, J.A.; Earle, J.D.; Melton, L.J. III

    1989-01-01

    A case-control study was conducted among residents of Rochester, Minn, to assess the influence of prior therapeutic radiation on the risk of primary hyperparathyroidism. Fifty-one cases of surgically proven primary hyperparathyroidism diagnosed from 1975 through 1983 were each matched by age and gender to two control subjects, with radiation exposure documented through preexisting medical records. The overall odds ratio for any prior therapeutic radiation therapy was 1.9 (95% confidence interval, 0.9 to 4.4) and it was 2.3 (95% confidence interval, 0.9 to 5.7) when limited to those with prior head and neck radiation. Among women, the figures were 2.9 (95% confidence interval, 1.1 to 7.5) for any prior therapeutic radiation and 3.4 (95% confidence interval, 1.2 to 10.2) for head and neck exposure. This study confirms the association between primary hyperparathyroidism and prior therapeutic radiation exposure, at least for women in this population

  9. Influence of radiation on structure of Venom Vipera Lebetina Obtusa

    International Nuclear Information System (INIS)

    Topchiyeva, Sh.A; Abiyev, H.A; Magerramov, A.

    2006-01-01

    Full text: Snake venoms are unique biologically active polymers of an animal origin. Though in the global literature the data are resulted on researching of zoo toxins, however many questions still remain not mentioned and need deep analysis and studying. Many questions on influence of small dozes gamma-radiation and other kinds ionization radiations on an alive organism remain open. These questions are important for technology of radiating sterilization of medical products, finding-out of the mechanism of additively and synergism, estimations of radio-ecological risk at influences of small dozes gamma-radiation on structure and dynamics of development of various biological and organic systems. In connection with special biochemical and preparations of venoms vipers and for an estimation of ecological factors (in particular, biotic, an electromagnetic field, gamma-radiation, solar radiation) on its properties we investigated influence gamma-radiation 6 0Co on structure at low temperatures. At low temperatures researches and at revealing prostrations effects in organic and biological systems of an organism from effective methods is radiotermoluminence.The method of radiotermoluminence will allow to receive data on structural properties of system, on the centers of stabilization of charges of initial products radials venom, about ways of migration of energy absorbed at an irradiation and so on. Samples on venom were irradiated in special a ditch with scales-beams at 77K up to dozes of %5 kGr. Before an irradiation samples were cleared of traces of oxygen. The irradiation was spent on air and in vacuum. Curves lighting registered with a speed gamma 50/1.min. It is shown, that in an interval of temperatures 77-330K the curve lighting radiotermoluminendce venom of vipers irradiated at 77K up to dozes 3 kGr is characterized not by a symmetric maximum at temperature 172K. Warming up to temperatures 320K results in monotonous decrease of intensity of a luminescence. It is

  10. Gamma Radiation Dosimetry Using Tellurium Dioxide Thin Film Structures

    Directory of Open Access Journals (Sweden)

    Olga Korostynska

    2002-08-01

    Full Text Available Thin films of Tellurium dioxide (TeO2 were investigated for γ-radiation dosimetry purposes. Samples were fabricated using thin film vapour deposition technique. Thin films of TeO2 were exposed to a 60Co γ-radiation source at a dose rate of 6 Gy/min at room temperature. Absorption spectra for TeO2 films were recorded and the values of the optical band gap and energies of the localized states for as-deposited and γ-irradiated samples were calculated. It was found that the optical band gap values were decreased as the radiation dose was increased. Samples with electrical contacts having a planar structure showed a linear increase in current values with the increase in radiation dose up to a certain dose level. The observed changes in both the optical and the electrical properties suggest that TeO2 thin film may be considered as an effective material for room temperature real time γ-radiation dosimetry.

  11. Quality control through dosimetry at a contract radiation processing facility

    International Nuclear Information System (INIS)

    Du Plessis, T.A.; Roediger, A.H.A.

    1985-01-01

    Reliable dosimetry procedures constitute a very important part of process control and quality assurance at a contract gamma radiation processing facility that caters for a large variety of different radiation applications. The choice, calibration and routine intercalibration of the dosimetry systems employed form the basis of a sound dosimetry policy in radiation processing. With the dosimetric procedures established, detailed dosimetric mapping of the irradiator upon commissioning (and whenever source modifications take place) is carried out to determine the radiation processing characteristics and peformance of the plant. Having established the irradiator parameters, routine dosimetry procedures, being part of the overall quality control measures, are employed. In addition to routine dosimetry, independent monitoring of routine dosimetry is performed on a bi-monthly basis and the results indicate a variation of better than 3%. On an annaul basis the dosimetry systems are intercalibrated through at least one primary standard dosimetry laboratory and to date a variation of better than 5% has been experienced. The company also participates in the Pilot Dose Assurance Service of the International Atomic Energy Agency, using the alanine/ESR dosimetry system. Routine calibration of the instrumentation employed is carried out on a regular basis. Detailed permanent records are compiled on all dosimetric and instrumentation calibrations, and the routine dosimetry employed at the plant. Certificates indicating the measured absorbed radiation doses are issued on request and in many cases are used for the dosimetric release of sterilized medical and pharmaceutical products. These procedures, used by Iso-Ster at its industrial gamma radiation facility, as well as the experience built up over a number of years using radiation dosimetry for process control and quality assurance are discussed. (author)

  12. Water Chemistry Control in Reducing Corrosion and Radiation Exposure at PWR Reactor

    International Nuclear Information System (INIS)

    Febrianto

    2006-01-01

    Water chemistry control plays an important role in relation to plant availability, reliability and occupational radiation exposures. Radiation exposures of nuclear plant workers are determined by the radiation rate dose and by the amount maintenance and repair work time Water chemistry has always been, from beginning of operation of power Pressurized Water Reactor, an important factor in determining the integrity of reactor components, fuel cladding integrity and minimize out of core radiation exposures. For primary system, the parameters to control the quality of water chemistry have been subject to change in time. Reactor water coolant pH need to be optimally controlled and be operated in range pH 6.9 to 7.4. At pH lower than 6.9, cause increasing the radiation exposure level and increasing coolant water pH higher than 7.4 will decrease radiation exposure level but increasing risk to fuel cladding and steam generator tube. Since beginning 90 decade, PWR water coolant pH tend to be operated at pH 7.4. This paper will discuss concerning water chemistry development in reducing corrosion and radiation exposure dose in PWR reactor. (author)

  13. On the structural-optical correlations in radiation-modified chalcogenide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kavetskyy, T; Tsmots, V [Solid State Microelectronics Laboratory, Drohobych Ivan Franko State Pedagogical University, 24 I. Franko Str., Drohobych, 82100 (Ukraine); Kaban, I; Hoyer, W [Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz (Germany); Shpotyuk, O, E-mail: kavetskyy@yahoo.com [Institute of Materials, Scientific Research Company ' Carat' , 202 Stryjska Str., Lviv, 79031 (Ukraine)

    2011-04-01

    In this work, we report our recent results on the gamma-irradiation-induced structural transformations in the Ge-Sb-S glasses as observed from the structural studies using high-energy synchrotron x-ray diffraction and extended x-ray absorption fine structure spectroscopy in comparison with the optical measurements using VIS/IR spectroscopy techniques. The structural-optical correlations in the radiation-induced effects are established. The structural changes upon irradiation are explained in the frames of the concept of coordination topological defects formation.

  14. On the structural-optical correlations in radiation-modified chalcogenide glasses

    International Nuclear Information System (INIS)

    Kavetskyy, T; Tsmots, V; Kaban, I; Hoyer, W; Shpotyuk, O

    2011-01-01

    In this work, we report our recent results on the gamma-irradiation-induced structural transformations in the Ge-Sb-S glasses as observed from the structural studies using high-energy synchrotron x-ray diffraction and extended x-ray absorption fine structure spectroscopy in comparison with the optical measurements using VIS/IR spectroscopy techniques. The structural-optical correlations in the radiation-induced effects are established. The structural changes upon irradiation are explained in the frames of the concept of coordination topological defects formation.

  15. Structural Pest Control.

    Science.gov (United States)

    Kahn, M. S.; Hoffman, W. M.

    This manual is designed for those who seek certification as pesticide applicators for industrial, institutional, structural, and health-related pest control. It is divided into six sections covering general pest control, wood-destroying organisms, bird control, fumigation, rodent control, and industrial weed control. The manual gives information…

  16. Radiation camera exposure control

    International Nuclear Information System (INIS)

    Martone, R.J.; Yarsawich, M.; Wolczek, W.

    1976-01-01

    A system and method for governing the exposure of an image generated by a radiation camera to an image sensing camera is disclosed. The exposure is terminated in response to the accumulation of a predetermined quantity of radiation, defining a radiation density, occurring in a predetermined area. An index is produced which represents the value of that quantity of radiation whose accumulation causes the exposure termination. The value of the predetermined radiation quantity represented by the index is sensed so that the radiation camera image intensity can be calibrated to compensate for changes in exposure amounts due to desired variations in radiation density of the exposure, to maintain the detectability of the image by the image sensing camera notwithstanding such variations. Provision is also made for calibrating the image intensity in accordance with the sensitivity of the image sensing camera, and for locating the index for maintaining its detectability and causing the proper centering of the radiation camera image

  17. Controlling occupational radiation exposure. Alternatives to regulation

    International Nuclear Information System (INIS)

    Sagan, L.A.; Squitieri, R.; Wildman, S.S.

    1980-01-01

    The principal strategy adopted for the control of occupational radiation exposure has been the establishment of standards expressed as maximum permissible exposures. The use of such standards is subject to a number of defects, among which is the neglect of the economic impact of imposing such standards. Furthermore, such standards carry the implication of a threshold for radiation effects, a concept now widely challenged. Lastly, the use of standards makes it impossible to evaluate the efficiency of the regulatory agency or to compare its performance with other similar agencies. An alternative to the use of standards, i.e. cost-benefit analysis, is discussed. The advantages of this technique meet many of the objections to the use of standards alone and allow health and safety resources to be allocated in a manner most likely to save the most lives. The greatest disadvantage of cost-benefit analysis has been the difficulty in evaluating the benefit side of the equation. Although the risks of radiation exposure are not known with precision, they are nevertheless well understood. Therefore, the application of cost-benefit analysis to occupational radiation exposure is rational. There are a number of barriers to reform in the use of standards and the adoption of cost-benefit analysis. These attitudinal and institutional constraints are discussed. The nature of private or market systems of control are discussed, i.e. the use of liability and insurance mechanisms. These also have shortcomings that require further development but are seen as potentially more efficient for both employer and employee than is the use of regulatory standards. (author)

  18. Generalized transmission line method to study the far-zone radiation of antennas under a multilayer structure

    CERN Document Server

    Wu, Xuan Hui

    2008-01-01

    This book gives a step-by-step presentation of a generalized transmission line method to study the far-zone radiation of antennas under a multilayer structure. Normally, a radiation problem requires a full wave analysis which may be time consuming. The beauty of the generalized transmission line method is that it transforms the radiation problem for a specific type of structure, say the multilayer structure excited by an antenna, into a circuit problem that can be efficiently analyzed. Using the Reciprocity Theorem and far-field approximation, the method computes the far-zone radiation due to

  19. Chemical structure and radiation stability of solid crystalline antibiotics: thiamphenicol and chloramphenicol

    International Nuclear Information System (INIS)

    Varshney, Lalit; Soe Nwe

    1997-01-01

    Antibiotics in solid state show significant radiation resistance and some of them are exposed to gamma or electron beam irradiation for sterilization. Even small radiation degradation in solid state antibiotics is not desirable. Two antibiotics namely thiamphenicol (TPL) and chloramphenicol (CPL) having similar chemical and solid state structure were irradiated at different graded radiation doses to study their stability. Differential scanning calorimetry (DSC) was used to evaluate purity, entropy of radiation processing, heat of fusion and melting point. (author). 3 refs., 1 tab

  20. The computerized radiation control system for the nuclear power plant

    International Nuclear Information System (INIS)

    Hunamoto, H.; Sato, T.; Taniguchi, K.

    1993-01-01

    Major works of Radiation control in nuclear power plant consist of occupational exposure control, radiation monitoring of working areas and surveillance of monitoring equipment, environmental monitoring and so on. Since a large amount of data will be generated from these works, therefore use of high performance computers will be indispensable. The systematization is presently being advanced in The Japan Atomic Power Company from this viewpoint and the project is being realized smoothly. The actual state is introduced

  1. Specific chemical and structural damage to proteins produced by synchrotron radiation.

    Science.gov (United States)

    Weik, M; Ravelli, R B; Kryger, G; McSweeney, S; Raves, M L; Harel, M; Gros, P; Silman, I; Kroon, J; Sussman, J L

    2000-01-18

    Radiation damage is an inherent problem in x-ray crystallography. It usually is presumed to be nonspecific and manifested as a gradual decay in the overall quality of data obtained for a given crystal as data collection proceeds. Based on third-generation synchrotron x-ray data, collected at cryogenic temperatures, we show for the enzymes Torpedo californica acetylcholinesterase and hen egg white lysozyme that synchrotron radiation also can cause highly specific damage. Disulfide bridges break, and carboxyl groups of acidic residues lose their definition. Highly exposed carboxyls, and those in the active site of both enzymes, appear particularly susceptible. The catalytic triad residue, His-440, in acetylcholinesterase, also appears to be much more sensitive to radiation damage than other histidine residues. Our findings have direct practical implications for routine x-ray data collection at high-energy synchrotron sources. Furthermore, they provide a direct approach for studying the radiation chemistry of proteins and nucleic acids at a detailed, structural level and also may yield information concerning putative "weak links" in a given biological macromolecule, which may be of structural and functional significance.

  2. Test of scalar meson structure in φ radiative decays

    International Nuclear Information System (INIS)

    Kumano, S.

    1992-12-01

    We show that φ radiative decays into scalar mesons [f 0 (975), a 0 (980) ≡ S] can provide important clues on the internal structures of these mesons. Radiative decay widths vary widely: B.R. = 10 -4 -10 -6 depending on the substructures (qq-bar, qqq-barq-bar, KK-bar, glueball). Hence, we could discriminate among various models by measuring these widths at future φ factories. The understanding of these meson structures is valuable not only in hadron spectroscopy but also in nuclear physics in connection with the widely-used but little-understood σ meson. We also find that the decay φ→S γ →K 0 K-bar 0 γ is not strong enough to pose a significant background problem for studying CP violation via φ→K 0 K-bar 0 at the φ factories. (author)

  3. Effects of Ionizing Radiation on Cellular Structures, Induced Instability, and Carcinogenesis

    International Nuclear Information System (INIS)

    Resat, Marianne S.; Arthurs, Benjamin J.; Estes, Brian J.; Morgan, william F.

    2006-01-01

    According to the American Cancer Society, the United States can expect 1,368,030 new cases of cancer in 2004 [1]. Among the many carcinogens Americans are exposed to, ionizing radiation will contribute to this statistic. Humans live in a radiation environment. Ionizing radiation is in the air we breathe, the earth we live on, and the food we eat. Man-made radiation adds to this naturally occurring radiation level thereby increasing the chance for human exposure. For many decades the scientific community, governmental regulatory bodies, and concerned citizens have struggled to estimate health risks associated with radiation exposures, particularly at low doses. While cancer induction is the primary concern and the most important somatic effect of exposure to ionizing radiation, potential health risks do not involve neoplastic diseases exclusively but also include somatic mutations that might contribute to birth defects and ocular maladies, and heritable mutations that might impact on disease risks in future generations. Consequently it is important we understand the effect of ionizing radiation on cellular structures and the subsequent long-term health risks associated with exposure to ionizing radiation

  4. Radiation exposure control during EMCCR campaign at MAPS

    International Nuclear Information System (INIS)

    Jawahar, S.; Singha Roy, S.

    2003-01-01

    Enmasse Coolant Channel Replacement (EMCCR) work is second of its kind for Indian PHWR- next to RAPS - 2 campaign- after successful demonstration of ability by NPCIL to carry out such major core component maintenance. The Challenges posed during such campaign are mainly attributed to the radiation field, continuous occupancy, and large quantity of material handling for execution as well as preparing infrastructure, exposure control for large number of workmen. Extensive planning was carried out to address all these issues in order to reduce the downtime of the station keeping the collective dose as low as reasonable achievable (ALARA). This paper highlights the strategy adopted, logistics involved in execution of work and the efforts taken to control radiation exposure during this major campaign. (author)

  5. Gamma radiation in pest control at the storehouses

    International Nuclear Information System (INIS)

    Tsvetkov, D.; Atanasov, Khr.; Berberov, D.

    1974-01-01

    The prospects of radiation control of wheat grain pests in Bulgaria are shown, drawing the following main conclusions: The lethal doses of gamma rays for the granary weevil, grain borer and confused flour beetle are fairly high - of the order of 300,000-400,000 r; the sterilizing doses of gamma rays arrest the reproduction of granary and rice weevils as well as of confused flour beetles. The irradiated insects, however, retain their sex activity and so may inhibit the reproduction of fertile populations. Irradiation strongly reduces the life span of, and consequently the damage done by, the insects; radiation control of stored-grain pests by using sterilizing doses does not deteriorate the technological quality of the wheat grain. (E.T.)

  6. Controlling of degradation effects in radiation processing of polymers

    International Nuclear Information System (INIS)

    2009-05-01

    The interest of Member States of the IAEA in introducing radiation technology into the polymer and plastics industry is growing. This publication summarizes a number of studies conducted in the framework of a coordinated research project (CRP) on controlling of degradation effects on polymers by radiation processing technologies. It reviews a variety of applications and details the most important results and achievements of the participating centres and laboratories during the course of the CRP. The publication is intended to be of use to scientists implementing the technology and managers of radiation processing facilities

  7. Structural defects in monocrystalline silicon: from radiation ones to growing and technological

    International Nuclear Information System (INIS)

    Gerasimenko, N.N.; Pavlyuchenko, M.N.; Dzhamanbalin, K.K.

    2001-01-01

    The systematical review of properties and conditions of radiation structures in monocrystalline silicon including own defects (elementary and complex, disordered fields) as well as defect-impurity formations is presented. The most typical examples of principle effects influence of known defects on radiation-induced processes (phase transformations, diffusion and heteration and others are considered. Experimental facts and models of silicon radiation amorphization have been analyzed in comparison of state of the radiation amorphization radiation problem of metals and alloys. The up-to-date status of the problem of the radiation defects physics are discussed, including end-of-range -, n+-, rod-like- defects. The phenomenon self-organization in crystals with defects has been considered. The examples of directed using radiation defects merged in independent trend - defects engineering - are given

  8. Structural aspects of crotalic venom proteins modified by ionizing radiation

    International Nuclear Information System (INIS)

    Oliveira, Karina Corleto de

    2010-01-01

    Snake bites are a serious public health problem, especially in subtropical countries. In Brazil, the Ministry of Health notified around 26 000 accidents in 2008. The genus Crotalus (rattlesnakes) accounts for approximately 7% of the total, with a high mortality rate of 72% when untreated with the specific serum, the only effective treatment in case of snake bites. In Brazil, the serum is produced in horses which, despite the large size, have a reduced lifespan due to the high toxicity of the antigen. Ionizing radiation has proven to be an excellent tool for reducing the toxicity of venoms and isolated toxins, resulting in better immunogens for serum production, and contributing to the welfare of serum producing animals. Since the action of gamma radiation on venoms and toxins has not been yet fully clarified from the structural point of view, we proposed in this paper, to characterize two toxins of the species Crotalus durissus terrificus: crotoxin and crotamine. After isolation of the toxins of interest by chromatographic techniques, they were subjected to structural analysis with the application of the following methods: Fluorescence, Circular Dichroism, Differential Calorimetry and Infrared Spectroscopy. These tests showed that both crotamine as crotoxin when subjected to gamma radiation, showed changes in their structural conformation compared with the samples in the native state. Such changes probably occur in the secondary and tertiary structure and may explain the changes on the biological activity of these toxins. (author)

  9. Sensitivity to plant modelling uncertainties in optimal feedback control of sound radiation from a panel

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    1997-01-01

    Optimal feedback control of broadband sound radiation from a rectangular baffled panel has been investigated through computer simulations. Special emphasis has been put on the sensitivity of the optimal feedback control to uncertainties in the modelling of the system under control.A model...... in terms of a set of radiation filters modelling the radiation dynamics.Linear quadratic feedback control applied to the panel in order to minimise the radiated sound power has then been simulated. The sensitivity of the model based controller to modelling uncertainties when using feedback from actual...

  10. Radiation (Safety Control) Ordinance 1978

    International Nuclear Information System (INIS)

    1978-01-01

    This Ordinance provides for the control, regulation, possession, use and transport of radioactive substance and irradiating apparatus. The Director of Health is responsible for administration of the Ordinance, which contains detailed provisions concerning the terms and conditions of licences, duties of licensees, medical examinations, maximum radiation doses, precautions to be taken to avoid exceeding such doses. The Ordinance also lays down a system of record-keeping and registration as well as packaging specifications for the transport of radioactive substances. (NEA) [fr

  11. Controlling radiated emissions by design

    CERN Document Server

    Mardiguian, Michel

    2014-01-01

    The 3rd edition of Controlling Radiated Emissions by Design has been updated to reflect the latest changes in the field. New to this edition is material related to technical advances, specifically super-fast data rates on wire pairs, with no increase in RF interference. Throughout the book, details are given to control RF emissions using EMC design techniques. This book retains the step-by-step approach for incorporating EMC into every new design from the ground up. It describes the selection of quieter IC technologies, their implementation into a noise-free printed circuit layout, and the gathering of these into a low emissions package. Also included is how to design an I/O filter, along with connectors and cable considerations. All guidelines are supported throughout with comprehensive calculated examples. Design engineers, EMC specialists, and technicians will benefit from learning about the development of more efficient and economical control of emissions.

  12. Sound transmission analysis of plate structures using the finite element method and elementary radiator approach with radiator error index

    DEFF Research Database (Denmark)

    Jung, Jaesoon; Kook, Junghwan; Goo, Seongyeol

    2017-01-01

    combines the FEM and Elementary Radiator Approach (ERA) is proposed. The FE-ERA method analyzes the vibrational response of the plate structure excited by incident sound using FEM and then computes the transmitted acoustic pressure from the vibrating plate using ERA. In order to improve the accuracy...... and efficiency of the FE-ERA method, a novel criterion for the optimal number of elementary radiators is proposed. The criterion is based on the radiator error index that is derived to estimate the accuracy of the computation with used number of radiators. Using the proposed criterion a radiator selection method...... is presented for determining the optimum number of radiators. The presented radiator selection method and the FE-ERA method are combined to improve the computational accuracy and efficiency. Several numerical examples that have been rarely addressed in previous studies, are presented with the proposed method...

  13. Structural Change of Biomolecules and Application of Synergistic Interaction by Radiation

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Kim, J. H.; Yang, J. S.

    2008-12-01

    It is expected that motivation and basic technologies for the future R and D plans can be provided from the results of this study. This study has been done to develop fundamentals for radiation applications based on the existing radiation technology, and to establish technical basis for enhancing efficacy of radiation utilization by studying the simultaneous application of ionizing radiation with another factor. Application of radiation technology together with the existing technologies to enhance the physical, chemical, biological characteristics through structural changes of biomolecules will exert a favorable influence on the creation of de novo scientific and industrial values. A theoretical model for the combined action of ionizing radiation with another factor can make it possible to predict a prior the maximum value of synergistic interaction and the conditions for it. Furthermore, the results of this study give a clues for establishment of fundamental theories associated with positive efficacy of radiation applications

  14. Structural Change of Biomolecules and Application of Synergistic Interaction by Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Kim, J. H.; Yang, J. S.

    2008-12-15

    It is expected that motivation and basic technologies for the future R and D plans can be provided from the results of this study. This study has been done to develop fundamentals for radiation applications based on the existing radiation technology, and to establish technical basis for enhancing efficacy of radiation utilization by studying the simultaneous application of ionizing radiation with another factor. Application of radiation technology together with the existing technologies to enhance the physical, chemical, biological characteristics through structural changes of biomolecules will exert a favorable influence on the creation of de novo scientific and industrial values. A theoretical model for the combined action of ionizing radiation with another factor can make it possible to predict a prior the maximum value of synergistic interaction and the conditions for it. Furthermore, the results of this study give a clues for establishment of fundamental theories associated with positive efficacy of radiation applications

  15. The role of ionizing radiation in biological control of agricultural pests

    International Nuclear Information System (INIS)

    Mansour, M.

    2011-01-01

    Although the commercial biological control industry is growing, it still represents only a small portion of the international market of pest control sales (about 3%). This low ratio is due to several factors including high cost of production of biological control agents and technical and regulatory difficulties that complicate the shipping procedures and create trade barriers. This article summarizes the role of ionizing radiation in supporting the use of biological control agents in insect pest control and concentrates on its role in the production, transport, distribution, and release of parasites and predators and the advantages that ionizing radiation can offer, in comparison with traditional techniques. (author)

  16. Earthquake design for controlled structures

    Directory of Open Access Journals (Sweden)

    Nikos G. Pnevmatikos

    2017-04-01

    Full Text Available An alternative design philosophy, for structures equipped with control devices, capable to resist an expected earthquake while remaining in the elastic range, is described. The idea is that a portion of the earthquake loading is under¬taken by the control system and the remaining by the structure which is designed to resist elastically. The earthquake forces assuming elastic behavior (elastic forces and elastoplastic behavior (design forces are first calculated ac¬cording to the codes. The required control forces are calculated as the difference from elastic to design forces. The maximum value of capacity of control devices is then compared to the required control force. If the capacity of the control devices is larger than the required control force then the control devices are accepted and installed in the structure and the structure is designed according to the design forces. If the capacity is smaller than the required control force then a scale factor, α, reducing the elastic forces to new design forces is calculated. The structure is redesigned and devices are installed. The proposed procedure ensures that the structure behaves elastically (without damage for the expected earthquake at no additional cost, excluding that of buying and installing the control devices.

  17. The Conference of Radiation Control Program Directors (CRCPD): a model for networking, cooperation, information exchange and regulation harmonization

    International Nuclear Information System (INIS)

    Gilley, Debbie Bray

    2008-01-01

    This presentation will be to introduce to the participants the Conference of Radiation Control Program Directors, Inc. (CRCPD) and the proven methods used by this organization for networking, information exchange, regulation development and standardization, and radiation protection guidance on emerging technologies. The presentation will describe how radiation control programs and staff from all 50 states in the US work collaboratively to ensure adequate radiation protection standards are uniformly applied throughout the country through the pooling of resources and networking between all the states and the federal government, as well as with international members and partners. The products of CRCPD, such as the Suggested State Regulations along with other relevant informational documents, will be discussed along with how participants can access these products for use in their respective countries. CRCPD and its members represent a comprehensive radiation regulatory structure, covering radioactive materials, radioactive waste, X-ray, accelerators, emergency response, environmental monitoring, radon, and security. Networks are in place for all radiation issues. After the presentation, participants will better understand how to develop and implement a cooperative partnership with other countries. They will also know how to access our products that can be tailored for their own use. They will also be informed of how to contact CRCPD and request technical assistance from one of our 1000 members through our international outreach initiative. (author)

  18. The IAEA Regional Training Course on Regulatory Control of Radiation Sources

    International Nuclear Information System (INIS)

    2000-01-01

    Materials of the IAEA Regional Training Course contains 8 presented lectures. Authors deals with regulatory control of radiation sources. The next materials of the IAEA were presented: Organization and implementation of a national regulatory infrastructure governing protection against ionizing radiation and the safety of radiation sources. (IAEA-TECDOC-1067); Safety assessment plants for authorization and inspection of radiation sources (IAEA-TECDOC-1113); Regulatory authority information system RAIS, Version 2.0, Instruction manual

  19. A Shared Compliance Control for Application in High Radiation Fields

    International Nuclear Information System (INIS)

    Ahn, Sung Ho; Jung, Hoan Sung; Lee, Kye Hong; Kim, Young Ki; Kim, Hark Rho

    2005-01-01

    Bilateral control systems present a technical alternative for intelligent robotic systems performing dexterous tasks in unstructured environments such as a nuclear facility, outer space and underwater. A shared compliance control scheme is proposed for application in high radiation fields in which the force sensor can not be installed because of a radiation effect. A position difference between the master system and the slave system is treated as an equivalent contact force and used for an input to the compliance controller. The compliance controller is implemented by a first order low pass filter and it modifies the position of the master to the reference position. Thus the compliance control task is shared by both the human operator's direct manual control and the autonomous compliance control of the slave system. Consequently, the position of a slave system tracks well the reference position and the compliance of the slave system is autonomously controlled in a contact condition. The simulation results show the excellence of the proposed scheme

  20. How geometry and structure control the seismic radiation : spectral element simulation of the dynamic rupture of the Mw 9.0 Tohoku earthquake

    Science.gov (United States)

    Festa, G.; Vilotte, J.; Scala, A.

    2012-12-01

    taking into account rapid and large variations of the impedance properties along the subduction interfaces and dynamic normal stress coupling. Based on a number of tomographic studies of the NE Japan subduction zone at different space, evidencing a high-velocity "toe" mantle wedge, and wide-angle reflection and refraction studies, supporting a non planar geometry of the subduction interface with at least two strong bending or kink features, we constrain the subduction geometry and the structural properties of the subduction zone model along an off-Miyagi profile. Through several simulations, we investigate possible structural control on the broadband rupture process of the Tohoku earthquake, in terms of the rupture velocity, seismic radiation and slip/stress distribution along the subduction interface. We Explored the influence of initial stress and interface behavior to capture the main features of the rupture and its radiation pattern. Implications for the broad band strong motion observation are discussed, together with implications for the seismic cycle and future earthquake nucleation.

  1. Resonant electronic transport through a triple quantum-dot with Λ-type level structure under dual radiation fields

    International Nuclear Information System (INIS)

    Guan, Chun; Xing, Yunhui; Zhang, Chao; Ma, Zhongshui

    2014-01-01

    Due to quantum interference, light can transmit through dense atomic media, a phenomenon known as electromagnetically induced transparency (EIT). We propose that EIT is not limited to light transmission and there is an electronic analog where resonant transparency in charge transport in an opaque structure can be induced by electromagnetic radiation. A triple-quantum-dots system with Λ-type level structure is generally opaque due to the level in the center dot being significantly higher and therefore hopping from the left dot to the center dot is almost forbidden. We demonstrate that an electromagnetically induced electron transparency (EIET) in charge of transport can indeed occur in the Λ-type system. The direct evidence of EIET is that an electron can travel from the left dot to the right dot, while the center dot apparently becomes invisible. We analyze EIET and the related shot noise in both the zero and strong Coulomb blockade regimes. It is found that the EIET (position, height, and symmetry) can be tuned by several controllable parameters of the radiation fields, such as the Rabi frequencies and detuning frequencies. The result offers a transparency/opaque tuning technique in charge transport using interfering radiation fields

  2. Synchrotron radiation and multichannel detectors in structural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mokulskii, M

    1979-10-01

    A survey is presented of the development of multichannel synchrotron X radiation detectors for the structural analysis of crystals. Tests are currently under way of a 4-thousand-channel plane detector of soft X radiation. The detector consists of a multiwire proportional counter using argon and CO/sub 2/ as the working gases. The detector is coupled to a computer processing information and displaying the respective X-ray diffraction images on the monitor. The described equipment allows imaging, eg., the cross section of the elementary cell of a DNA crystal. A 16-thousand-channel detector exists in the present time and the building is envisaged of a detector with 65 thousand channels.

  3. Synchrotron radiation and multichannel detectors in structural analysis

    International Nuclear Information System (INIS)

    Mokulskij, M.

    1979-01-01

    A survey is presented of the development of multichannel synchrotron X radiation detectors for the structural analysis of crystals. Tests are currently under way of a 4-thousand-channel plane detector of soft X radiation. The detector consists of a multiwire proportional counter using argon and CO 2 as the working gases. The detector is coupled to a computer processing information and displaying the respective X-ray diffraction images on the monitor. The described equipment allows imaging, eg., the cross section of the elementary cell of a DNA crystal. A 16-thousand-channel detector exists in the present time and the building is envisaged of a detector with 65 thousand channels. (J.B.)

  4. On the fine structure of the Vavilov-Cherenkov radiation

    International Nuclear Information System (INIS)

    Afanas'ev, G.N.; Kartavenko, V.G.; Zrelov, V.P.

    2003-01-01

    The aim of this paper is to study the fine structure of the Cherenkov rings. We analyze Zrelov's experiments in which the Cherenkov radiation was detected without using the special focusing devices. The broad Cherenkov ring was observed in the plane perpendicular to the motion axis. Using the exact and approximate formulae, we investigate how a charge uniformly moving in a medium radiates in a finite space interval. The formulae obtained describe the radiation intensity in the whole space interval, inside and outside the Cherenkov ring. In the plane perpendicular to the motion axis, the radiation fills mainly the finite ring. Its width, proportional to the motion interval, and the energy released in this ring do not depend on the position of the observation plane. Outside the Cherenkov ring, the radiation intensity suddenly drops. Inside it, the radiation intensity exhibits small oscillations which are due to the interference of the Vavilov-Cherenkov radiation and bremsstrahlung. The increase in the radiation intensity at the ends of the Cherenkov ring is associated with the shock waves arising at the beginning and the end of the charge motion and at the moments when the charge velocity coincides with the light velocity in a medium. For the chosen motion interval, the well-known Tamm formula does not describe the radiation intensity inside the Cherenkov ring for any position of the observation plane. Outside the Cherenkov ring, the Tamm formula is valid only at very large observation distances. Theoretical calculations are in satisfactory agreement with experimental data. Thus, the combined experimental and theoretical study of the unfocused Cherenkov rings allows one to obtain information on the physical processes accompanying the Cherenkov radiation (bremsstrahlung, transition of the light velocity barrier, etc.)

  5. Influence of radiation on structure of venom vipera lebetina obtusa

    International Nuclear Information System (INIS)

    Topchiyeva, Sh.A.; Abiyev, H.A.; Magerramov, A.

    2006-01-01

    Full text: Snake venoms are unique biologically active polymers of an animal origin. Though in the global literature the data are resulted on researching of zootoxins, however many questions still remain not mentioned and need deep analysis and studying. Many questions on influence of small dozes - radiation and other kinds ionization radiations on an alive organism remain open. These questions are important for technology of radiating sterilization of medical products, finding-out of the mechanism of additivity and sinergizm, estimations of radio-ecological risk at influences of small dozes - radiation on structure and dynamics of development of various biological and organic systems. In connection with special biochemical and preparations properties of venoms viperas and for an estimation of ecological factors (in particular, abiotics, an electromagnetic field, -radiation, solar radiation) on its properties we investigate influence - radiation n-tildei-circumflex 60 on structure at low temperatures. At low temperatures researches and at revealing postrations' effects in organic and biological systems of an organism from effective methods is radiotermoluminence. The method of radiotermoluminence will allow to receive data on structural properties of system, on the centers of stabilization of charges of initial products radiolis venom, about ways of migration of energy absorbed at an irradiation and so on. Samples of venom were irradiated in special a ditch with scales - beams at 77 E-tilde up to dozes of percent 5 e-tildeGr. Before an irradiation samples were cleared of traces of oxygen. The irradiation was spent on air and in vacuum. Curves lighting registered with a speed ∼ 50/l.min. It is shown, that in an interval of temperatures 77-330 E-tilde the curve lighting radiotermoluminence venom of viperas irradiated at 77 E-tilde up to dozes 3 ?Gr is characterized not by a symmetric maximum at temperature 172 E-tilde. Warming up up to temperatures 320E

  6. Structural-electrical coupling optimisation for radiating and scattering performances of active phased array antenna

    Science.gov (United States)

    Wang, Congsi; Wang, Yan; Wang, Zhihai; Wang, Meng; Yuan, Shuai; Wang, Weifeng

    2018-04-01

    It is well known that calculating and reducing of radar cross section (RCS) of the active phased array antenna (APAA) are both difficult and complicated. It remains unresolved to balance the performance of the radiating and scattering when the RCS is reduced. Therefore, this paper develops a structure and scattering array factor coupling model of APAA based on the phase errors of radiated elements generated by structural distortion and installation error of the array. To obtain the optimal radiating and scattering performance, an integrated optimisation model is built to optimise the installation height of all the radiated elements in normal direction of the array, in which the particle swarm optimisation method is adopted and the gain loss and scattering array factor are selected as the fitness function. The simulation indicates that the proposed coupling model and integrated optimisation method can effectively decrease the RCS and that the necessary radiating performance can be simultaneously guaranteed, which demonstrate an important application value in engineering design and structural evaluation of APAA.

  7. Design concept of radiation control system for the high intensity proton accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Yukihiro; Ikeno, Koichi; Akiyama, Shigenori; Harada, Yasunori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-11-01

    Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics. (author)

  8. Regulatory control of radiation sources in Germany

    International Nuclear Information System (INIS)

    Coy, K.

    1998-01-01

    The regulatory programme governing the safe use of radioisotopes in Germany is based on the federal legislation enacted as Atomic Energy Control Act (Atomgesetz) and Radiation Protection Ordinance (Strahlen-schutzverordnung) and its implementation by the competent authorities of the individual states. Despite this highly decentralized infrastructure of enforcement the basic principles of regulations described in this paper such as authorization criteria, conditions imposed as well as depth and intensity of inspection balanced according to the individual radiation hazard involved are harmonized to the greatest possible extent by regular coordination among the competent authorities as well as a series of technical regulations such as standards and guidelines. (author)

  9. Regulatory Control of Radiation Sources. Safety Guide

    International Nuclear Information System (INIS)

    2009-01-01

    This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

  10. Structural analysis of γ radiation-induced chromosomal aberrations observed by atomic force microscopy

    International Nuclear Information System (INIS)

    Qu Shuang; Chen Ying; Ge Shili; Liu Xiulin; Zhou Pingkun; Zhang Sa; Zhang Detian

    2003-01-01

    Objective: To find a new method for the measurement of radiation-induced damage, the structures of normal chromosomes and 60 Co γ-ray-induced chromosomal aberration were analyzed by atomic force microscopy. Methods: Normal and irradiated chromosomes of human peripheral blood lymphocytes were prepared, then three-dimensional structure and height of chromosomes were analyzed by atomic force microscopy. Results: Three-dimensional structures of normal chromosomes and dicentric aberration in irradiated chromosomes were observed clearly. The data of chromosome height were helpful to recognizing the dicentric aberrations. Conclusion: Atomic force microscopy providing three-dimension image and linear measurement is a new and valuable tool for structural analysis of radiation-induced chromosomal aberrations

  11. Radiation effects in structural materials of spallation targets

    Science.gov (United States)

    Jung, P.

    2002-02-01

    Effects of radiation damage by protons and neutrons in structural materials of spallation neutron sources are reviewed. Effects of atomic displacements, defect mobility and transmutation products, especially hydrogen and helium, on physical and mechanical properties are discussed. The most promising candidate materials (austenitic stainless steels, ferritic/martensitic steels and refractory alloys) are compared, and needed investigations are identified.

  12. Reactor Start-up and Control Methodologies: Consideration of the Space Radiation Environment

    International Nuclear Information System (INIS)

    Bragg-Sitton, Shannon M.; Holloway, James Paul

    2004-01-01

    The use of fission energy in space power and propulsion systems offers considerable advantages over chemical propulsion. Fission provides over six orders of magnitude higher energy density, which translates to higher vehicle specific impulse and lower specific mass. These characteristics enable the accomplishment of ambitious space exploration missions. The natural radiation environment in space provides an external source of protons and high energy, high Z particles that can result in the production of secondary neutrons through interactions in reactor structures. Initial investigation using MCNPX 2.5.b for proton transport through the SAFE-400 reactor indicates a secondary neutron net current of 1.4x107 n/s at the core-reflector interface, with an incoming current of 3.4x106 n/s due to neutrons produced in the Be reflector alone. This neutron population could provide a reliable startup source for a space reactor. Additionally, this source must be considered in developing a reliable control strategy during reactor startup, steady-state operation, and power transients. An autonomous control system is developed and analyzed for application during reactor startup, accounting for fluctuations in the radiation environment that result from changes in vehicle location (altitude, latitude, position in solar system) or due to temporal variations in the radiation field, as may occur in the case of solar flares. One proposed application of a nuclear electric propulsion vehicle is in a tour of the Jovian system, where the time required for communication to Earth is significant. Hence, it is important that a reactor control system be designed with feedback mechanisms to automatically adjust to changes in reactor temperatures, power levels, etc., maintaining nominal operation without user intervention. This paper will evaluate the potential use of secondary neutrons produced by proton interactions in the reactor vessel as a startup source for a space reactor and will present a

  13. Crown structure, radiation absorption, photosynthesis and transpiration

    OpenAIRE

    Wang, Yingping

    1988-01-01

    A complex simulation model, MAESTRO, has been developed and validated against field measurements in plantation in both Scotland and Australia. It has been shown that MAESTRO can reasonably predict the daily course of PAR (photosynetically active radiation) transmittance at points below the canopies of radiata pine and Sitka spruce plantations. 1. Four structural properties of the Sitka spruce tree crown have been identified and evaluation in relation to PAR absorption, photosynthesis and ...

  14. Structural analysis with high brilliance synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Hideo [Japan Atomic Energy Research Inst., Kamigori, Hyogo (Japan). Kansai Research Establishment

    1997-11-01

    The research subjects in diffraction and scattering of materials with high brilliance synchrotron radiation such as SPring-8 (Super Photon ring 8 GeV) are summarized. The SPring-8 project is going well and 10 public beamlines will be opened for all users in October, 1997. Three JAERI beamlines are also under construction for researches of heavy element science, physical and structural properties under extreme conditions such as high temperature and high pressure. (author)

  15. Control of sources of ionizing radiation in Lithuania

    International Nuclear Information System (INIS)

    Mastauskas, Albinas; Ziliukas, Julius; Morkunas, Gendrutis

    1997-01-01

    Aspects connected with regulatory control of radioactive sources in Lithuania, such as keeping of the computer-based registry, investigation of arrested illegal radioactive material, decision making, control of users of radioactive sources are discussed. Most of the sources of ionizing radiation are smoke detectors and x-ray equipment. Potentially most dangerous sources (both sealed and unsealed) of therapy and industry are also presented

  16. Morfofunctional indices of peripheric blood for persons working within the strict radiation control area

    International Nuclear Information System (INIS)

    Nyagu, A.I.; Yukhimuk, L.N.; Egorova, D.M.; Pogontseva, I.M.

    1992-01-01

    The blood of 118 people permanently working within the area of strict radiation control has been investigated. Erythrocyte morphofunctional value has been estimated taking into consideration the erythrocyte morphological index as well as mechanical and osmotic resistivity of erythrocytes. For people permanently working within the area of strict radiation control intensity of signals of EPR for blood paramagnetic centres essentially changes. It proves profound changes in functioning of blood plasma antioxidant system for people working in the area of strict radiation control. For the people permanently working within the area of strict radiation control in peripheric blood growth of echynocytes and spherocytes as well as lowering of mechanical resistivity of erythrocytes is observed. 4 refs.; 1 fig.; 1 tab

  17. Computer simulation of radiation damage in HTGR elements and structural materials

    International Nuclear Information System (INIS)

    Gann, V.V.; Gurin, V.A.; Konotop, Yu.F.; Shilyaev, B.A.; Yamnitskij, V.A.

    1980-01-01

    The problem of mathematical simulation of radiation damages in material and items of HTGR is considered. A system-program complex IMITATOR, intended for imitation of neutron damages by means of charged particle beams, is used. Account of material composite structure and certain geometry of items permits to calculate fields of primary radiation damages and introductions of reaction products in composite fuel elements, microfuel elements, their shells, composite absorbing elements on the base of boron carbide, structural steels and alloys. A good correspondence of calculation and experimental burn-out of absorbing elements is obtained, application of absorbing element as medium for imitation experiments is grounded [ru

  18. Effect of Cell Phone Radiations on Orofacial Structures: A Systematic Review

    Science.gov (United States)

    Chowdhary, Ramesh; Kumari, Shail; Rao, Srinivasa B

    2017-01-01

    Introduction: The widespread use of cell phone in recent years has raised many questions whether their use is safe to operator who is exposed to Electromagnetic Waves (EMV). Aim To find out the effect of cell phone emitted radiations on the orofacial structures. Materials and Methods To identify suitable literature, an electronic search was performed using Medline, Pubmed and EBSCO host database in December 2016. The search was focused on effect of cell phone on orofacial structures. Among the literature available in English, the screening of the related titles and abstracts was done, and only those articles were selected for full text reading that fulfilled the inclusion criteria. Results The initial literature search resulted in 360 articles out of which only 24 articles fulfilled the inclusion criteria and were included in this systematic review. Conclusion Cell phone emitted radiations had their adverse effect on salivary glands and facial nerves. Studies showed that cell phone emitted radiations had effects on oral mucosal cells and causes changes in salivary flow rate. It was still unclear that cell phone radiations cause tumours of the salivary glands. PMID:28658925

  19. Development of the radiation control system for personal permission, status and record

    International Nuclear Information System (INIS)

    Miyamoto, A.; Yamazaki, H.; Yuki, H.; Nanao, M.; Sugawara, Y.; Ohtsuki, T.

    2003-01-01

    The radiation control system for automated locks, personal status, and recordings in the database was developed at Laboratory of Nuclear Science (LNS), Tohoku University. It consists of the Programmable Logic Controllers (PLC) for the entrance system and Windows PC. The PLC is controlled with Fins Gateway and Compolet on the Windows PC through an ethernet. The SQL Server 2000 was also installed on the Windows PC for database management. In the system, personal data such as destination, purpose, working hours and radiation dose are stored in the database. Furthermore, monthly report of personal data can easily be printed out by using the system. Personal status can be checked by a status monitor of the accelerator in the operation room and the entrance of the radiation controlled area, etc. (author)

  20. Tolerance of retroperitoneal structures to intraoperative radiation

    International Nuclear Information System (INIS)

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

    1982-01-01

    In conjunction with the clinical development of intraoperative radiotherapy, a study was undertaken in dogs to define the tolerance of normal anatomic structures in the retroperitoneum to radiation delivered during operation. Twenty adult dogs were subjected to laparotomy and intraoperative 11 MeV electron irradiation in single doses ranging from 0.to 5000 rad. Animals were followed regularly with clinical observation, blood count, serum chemistries, pyelography, and angiography. Animals were sacrificed and autopsied at regular intervals up to 12 months following treatment to assess radiation-induced complications or tissue damage. Irradiation field in all dogs consisted of a 4 X 15 cm rectangle extending in the retroperitoneum from the level of the renal vessels to the bifurcation of aorta and vena cava. The field included aorta, vena cava, inferior portion of left kidney, and distal portion of left ureter. No complications or histologic changes occurred in any animal given doses of 2000 rad, with a follow-up in excess of 18 months. A dose of 3000 rad was well tolerated, except for left ureteral occlusion in one animal. Mild vascular fibrosis was present inthe aorta and vena cava, and significant ureteral fibrosis developed by six months after doses of 4000 or 5000 rad. All animals that received 5000 rad died of radiation-related complications, including ureteral obstruction and rectal perforation. It was concluded that major vessels tolerate intraoperative irradiation well up to and including 3000 rad and that no clinically significant vascular problems develop after 4000 and 5000 rad, although some fibrosis does occur. The ureter and kidney appear to be the most radiosensitive structures inthe retroperitoneum, showing progressive changes at 300 rad or greater and showing the potential for serious complications after doses of 4000 rad or more

  1. Adaptive piezoelectric sensoriactuators for active structural acoustic control

    Science.gov (United States)

    Vipperman, Jeffrey Stuart

    1997-09-01

    piezostructures were used to demonstrate and verify the adaptive piezoelectric sensoriactuator, a cantilevered beam and a simply-supported plate. The experimental open- loop results compare well with theory. A preliminary closed-loop rate controller applied to the cantilevered beam demonstrates simultaneous control and adaptation of the piezoelectric sensoriactuator. Lastly, [/cal H]2 optimal feedback Active Structural Acoustic Control (ASAC) is demonstrated using the adaptive piezoelectric sensoriactuators and the simply- supported plate test bed. A cost function is formulated based upon control effort and predicted radiated acoustic power. Radiation filters are created to predict acoustic power based on the self and mutual radiation efficiencies of the plate modes to be controlled. Both static output feedback and state-feedback compensation as well as dynamic (Linear Quadratic Gaussian) compensation are investigated and compared analytically. The importance of choosing an appropriate spatial aperture for the piezoceramic transducer for static compensation is discussed. Finally, multivariable Active Vibration Control (AVC) and ASAC are implemented experimentally on a simply-supported plate test bed using an array of four Adaptive Piezoelectric Sensoriactuators as the control sensors and actuators. Unfavorable high-frequency response from the given piezoceramic transducers required that dynamic, Linear Quadratic Gaussian (LQG) compensation be used to achieve good control performance.

  2. Effects of radiation on the structure of bothropstoxin-1

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, P.J. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: pspencer@net.ipen.br

    2000-07-01

    Ionizing radiation has been widely employed to attenuate venoms and toxins, preserving and even enhancing their immunogenic properties. However, little is known about molecular changes in irradiated proteins. In this work, we compared native and irradiated bothropstoxin-1, with the aim of characterizing the structural modifications induced by radiation. Our results indicate that radiation promotes a transition from the multimeric to the monomeric state in a dose-dependent manner. Spectral and calorimetric analysis suggest that the irradiated molecules undergo oxidation and partially unfold the remaining elements being stabilized by the seven disulphide bonds. The binding pattern of monoclonal antibodies raised against irradiated bothropstoxin indicated that most of the recognized epitopes are linear present on the surface of both native and irradiated toxin. Also, irradiated toxin appears to be more immunogenic, inducing the formation of native toxin-binding antibodies. (author)

  3. Radiation control and safety of fast reactor; Radijaciona kontrola i sigurnost postrojenja sa brzim reaktorom

    Energy Technology Data Exchange (ETDEWEB)

    Pesic, M; Antic, D [Boris Kidric Institute of Nuclear Sciences Vinca, Belgrade (Yugoslavia)

    1983-07-01

    The fundamental activities for safeguard of radiation control and safety and the necessary staff for them for fast reactor plant are shown. The basic systems for the plant radiation control are counted, especially with regards to poisoning of some fuel materials. The particular characteristics of the plant radiation control determined by the fast reactor are pointed out. (author)

  4. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    International Nuclear Information System (INIS)

    Sabanero, M.; Flores V, L. L.; Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M.; Castruita D, J. P.; Barbosa S, G.

    2015-10-01

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H 2 O 2 /1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  5. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Sabanero, M.; Flores V, L. L. [Universidad de Guanajuato, Departamento de Biologia, DCNE, Noria Alta s/n, 36250 Guanajuato, Gto. (Mexico); Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, DCI, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Castruita D, J. P. [Universidad de Guadalajara, Departamento de Ecologia, CUCBA, Las Agujas, 45100 Zapopan, Jalisco (Mexico); Barbosa S, G., E-mail: myrna.sabanero@gmail.com [Universidad de Guanajuato, Departamento de Ciencias Medicas, DCS, 20 de Enero No. 929, Col. Obregon, 37000 Leon, Guanajuato (Mexico)

    2015-10-15

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H{sub 2}O{sub 2}/1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  6. High temperature glass thermal control structure and coating. [for application to spacecraft reusable heat shielding

    Science.gov (United States)

    Stewart, D. A.; Goldstein, H. E.; Leiser, D. B. (Inventor)

    1983-01-01

    A high temperature stable and solar radiation stable thermal control coating is described which is useful either as such, applied directly to a member to be protected, or applied as a coating on a re-usable surface insulation (RSI). It has a base coat layer and an overlay glass layer. The base coat layer has a high emittance, and the overlay layer is formed from discrete, but sintered together glass particles to give the overlay layer a high scattering coefficient. The resulting two-layer space and thermal control coating has an absorptivity-to-emissivity ratio of less than or equal to 0.4 at room temperature, with an emittance of 0.8 at 1200 F. It is capable of exposure to either solar radiation or temperatures as high as 2000 F without significant degradation. When used as a coating on a silica substrate to give an RSI structure, the coatings of this invention show significantly less reduction in emittance after long term convective heating and less residual strain than prior art coatings for RSI structures.

  7. Regulatory control of radiation sources in the Philippines

    International Nuclear Information System (INIS)

    Daroy, Rosita R.

    1995-01-01

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI's regulatory functions are presented. (author)

  8. Track structure based modelling of light ion radiation effects on nuclear and mitochondrial DNA

    Science.gov (United States)

    Schmitt, Elke; Ottolenghi, Andrea; Dingfelder, Michael; Friedland, Werner; Kundrat, Pavel; Baiocco, Giorgio

    2016-07-01

    Space radiation risk assessment is of great importance for manned spaceflights in order to estimate risks and to develop counter-measures to reduce them. Biophysical simulations with PARTRAC can help greatly to improve the understanding of initial biological response to ionizing radiation. Results from modelling radiation quality dependent DNA damage and repair mechanisms up to chromosomal aberrations (e.g. dicentrics) can be used to predict radiation effects depending on the kind of mixed radiation field exposure. Especially dicentric yields can serve as a biomarker for an increased risk due to radiation and hence as an indicator for the effectiveness of the used shielding. PARTRAC [1] is a multi-scale biophysical research MC code for track structure based initial DNA damage and damage response modelling. It integrates physics, radiochemistry, detailed nuclear DNA structure and molecular biology of DNA repair by NHEJ-pathway to assess radiation effects on cellular level [2]. Ongoing experiments with quasi-homogeneously distributed compared to sub-micrometre focused bunches of protons, lithium and carbon ions allow a separation of effects due to DNA damage complexity on nanometre scale from damage clustering on (sub-) micrometre scale [3, 4]. These data provide an unprecedented benchmark for the DNA damage response model in PARTRAC and help understand the mechanisms leading to cell killing and chromosomal aberrations (e.g. dicentrics) induction. A large part of space radiation is due to a mixed ion field of high energy protons and few heavier ions that can be only partly absorbed by the shielding. Radiation damage induced by low-energy ions significantly contributes to the high relative biological efficiency (RBE) of ion beams around Bragg peak regions. For slow light ions the physical cross section data basis in PARTRAC has been extended to investigate radiation quality effects in the Bragg peak region [5]. The resulting range and LET values agree with ICRU data

  9. Effect of gamma radiation on honey quality control

    International Nuclear Information System (INIS)

    Bera, A.; Almeida-Muradian, L.B.; Sabato, S.F.

    2009-01-01

    Honey is one of the most complex substances produced by bees, mainly from the nectar of flowers. Gamma radiation is a technique that can be used to decrease the number of microbiological problems associated with food and increase the shelf life of certain products. The objective of this study was to verify the effect of gamma radiation with source of cobalto-60 (10 kGy) on some parameters used in honey quality control. Seven samples of pure honey were obtained from local markets in Sao Paulo, Brazil, in 2007. The methods used are in accordance with Brazilian Regulations. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The results showed that gamma radiation, in the dose mentioned above, did not cause significant physicochemical alterations.

  10. Effect of gamma radiation on honey quality control

    Energy Technology Data Exchange (ETDEWEB)

    Bera, A. [Radiation Technology Center, IPEN-CNEN/SP, A. Lineu Prestes, 2242, 05508-000 Sao Paulo (Brazil)], E-mail: berale@usp.br; Almeida-Muradian, L.B. [Av. Prof. Lineu Prestes, 580-Cidade Universitaria, Sao Paulo (Brazil); Sabato, S.F. [Radiation Technology Center, IPEN-CNEN/SP, A. Lineu Prestes, 2242, 05508-000 Sao Paulo (Brazil)], E-mail: sfsabato@ipen.br

    2009-07-15

    Honey is one of the most complex substances produced by bees, mainly from the nectar of flowers. Gamma radiation is a technique that can be used to decrease the number of microbiological problems associated with food and increase the shelf life of certain products. The objective of this study was to verify the effect of gamma radiation with source of cobalto-60 (10 kGy) on some parameters used in honey quality control. Seven samples of pure honey were obtained from local markets in Sao Paulo, Brazil, in 2007. The methods used are in accordance with Brazilian Regulations. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The results showed that gamma radiation, in the dose mentioned above, did not cause significant physicochemical alterations.

  11. A quality control program for radiation sources

    International Nuclear Information System (INIS)

    Almeida, C.E. de; Sibata, C.H.; Cecatti, E.R.; Kawakami, N.S.; Alexandre, A.C.; Chiavegatti Junior, M.

    1982-01-01

    An extensive quality control program was established covering the following areas: physical parameters of the therapeutical machines, dosimetric standards, preventive maintenance of radiation sources and measuring instruments. A critical evaluation of this program was done after two years (1977-1979) of routine application and the results will be presented. The fluctuation on physical parameters strongly supports the efforts and cost of a quality control program. This program has certainly improved the accuracy required on the delivery of the prescribed dose for radiotherapy treatment. (Author) [pt

  12. The calibration procedure of the radiation monitoring system installed in radiation controlled area of KOMAC

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Kyun; Min, Yi-Sub; Park, Jeong-Min; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

    2016-10-15

    The spaces, where these accelerators are installed, are defined as the radiation controlled area and the levels of the radiation in this area are monitored by the radiation monitoring system (RMS) to protect radiation workers and experiment users from the hazards of the ionizing radiation and the surface and air contamination tests are carried out periodically by the radiation secure team. The most of RMS instruments are installed in the accelerator building, where the 100-MeV proton linear accelerator is installed. All detectors of RMS should be calibrated every year to prove the reliability of RMS and almost all instruments for RMS was calibrated during this summer maintenance period of KOMAC this year. Almost all RMS instruments installed in KOMAC is calibrated between 2016-07-13 and 2016-08-24. As the calibration result, if the current reading value are within the 5% of the reference dose rate value, this RMS instrument can be used one more year. Otherwise, the detector of that RMS instrument should be repaired or replaced. The self-calibration certificate for each RMS instrument will be published only for the instrument to satisfy the condition.

  13. New patient-controlled abdominal compression method in radiography: radiation dose and image quality.

    Science.gov (United States)

    Piippo-Huotari, Oili; Norrman, Eva; Anderzén-Carlsson, Agneta; Geijer, Håkan

    2018-05-01

    The radiation dose for patients can be reduced with many methods and one way is to use abdominal compression. In this study, the radiation dose and image quality for a new patient-controlled compression device were compared with conventional compression and compression in the prone position . To compare radiation dose and image quality of patient-controlled compression compared with conventional and prone compression in general radiography. An experimental design with quantitative approach. After obtaining the approval of the ethics committee, a consecutive sample of 48 patients was examined with the standard clinical urography protocol. The radiation doses were measured as dose-area product and analyzed with a paired t-test. The image quality was evaluated by visual grading analysis. Four radiologists evaluated each image individually by scoring nine criteria modified from the European quality criteria for diagnostic radiographic images. There was no significant difference in radiation dose or image quality between conventional and patient-controlled compression. Prone position resulted in both higher dose and inferior image quality. Patient-controlled compression gave similar dose levels as conventional compression and lower than prone compression. Image quality was similar with both patient-controlled and conventional compression and was judged to be better than in the prone position.

  14. Towards Automatic Decentralized Control Structure Selection

    DEFF Research Database (Denmark)

    Jørgensen, John Bagterp; Jørgensen, Sten Bay

    2000-01-01

    for decentralized control is determined automatically, and the resulting decentralized control structure is automatically tuned using standard techniques. Dynamic simulation of the resulting process system gives immediate feedback to the process design engineer regarding practical operability of the process......A subtask in integration of design and control of chemical processes is the selection of a control structure. Automating the selection of the control structure enables sequential integration of process and control design. As soon as the process is specified or computed, a structure....... The control structure selection problem is formulated as a special MILP employing cost coefficients which are computed using Parseval's theorem combined with RGA and IMC concepts. This approach enables selection and tuning of large-scale plant-wide decentralized controllers through efficient combination...

  15. Conference of Radiation Control Program Directors, Inc. (CRCPD). A model for networking, cooperation, resource sharing, information exchange and regulation harmonization

    International Nuclear Information System (INIS)

    2007-01-01

    The focus of the talk will be to introduce the participants to the Conference of Radiation Control Program Directors, Inc. (CRCPD) and their proven methods for networking, information exchange, regulation development and standardization, and radiation protection guidance on emerging technologies. The presentation will describe how radiation control programs and staff from all 50 states in the US work collaboratively to ensure adequate radiation protection standards are uniformly applied throughout the country by pooling of resources and networking between all the states and the federal government, as well as with international members and partners. The products of CRCPD, such as the Suggested State Regulations along with other relevant informational documents, will be discussed along with how participants can access these products for use in their respective countries. CRCPD and its members represent a comprehensive radiation regulatory structure, covering all radiation sources and activities, (radioactive materials, licensing, registration, radioactive waste, x-ray, accelerators, emergency response, environmental monitoring, radon, and security). Networks are in place for all radiation issues. At the completion of this presentation, the participants will better understand a proven method to develop and implement a cooperative partnership with other countries. They will also gain knowledge on how to access CRCPD products that can be tailored for their own use and how to request technical assistance from membership. (author)

  16. Ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate.

    Science.gov (United States)

    Yamamoto, Seiichi; Kamada, Kei; Yoshikawa, Akira

    2018-02-16

    High resolution imaging of radiation is required for such radioisotope distribution measurements as alpha particle detection in nuclear facilities or high energy physics experiments. For this purpose, we developed an ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate. We used a ~1-μm diameter fiber structured GdAlO 3 :Ce (GAP) /α-Al 2 O 3 scintillator plate to reduce the light spread. The fiber structured scintillator plate was optically coupled to a tapered optical fiber plate to magnify the image and combined with a lens-based high sensitivity CCD camera. We observed the images of alpha particles with a spatial resolution of ~25 μm. For the beta particles, the images had various shapes, and the trajectories of the electrons were clearly observed in the images. For the gamma photons, the images also had various shapes, and the trajectories of the secondary electrons were observed in some of the images. These results show that combining an optical fiber structure scintillator plate with a tapered optical fiber plate and a high sensitivity CCD camera achieved ultrahigh resolution and is a promising method to observe the images of the interactions of radiation in a scintillator.

  17. Practice of radiation dose control for tech-modification items in Qinshan Nuclear Power Plant

    International Nuclear Information System (INIS)

    Zhang Yong; Chen Zhongyu; Xu Hongming; Fan Liguang; Jiang Jianqi; Bu Weidong

    2006-01-01

    In order to improve the safety and reliability of nuclear power plant operation, many tech-modifications related to system or equipment have been completed since operation in Qinshan NPP. this paper introduces radiation dose control for mainly tech-modifications items related to radiation, including radiation protection optimization measures and experience in aspects of item planning, program writing, process control, etc. (authors)

  18. 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

  19. Different Approaches in Radiation Therapy

    Directory of Open Access Journals (Sweden)

    Rolf-Dieter eKortmann

    2011-12-01

    Full Text Available Radiation therapy is a cornerstone in the therapeutic management of craniopharyngioma. The close proximity to neighbouring eloquent structures pose a particular challenge to radiation therapy. Modern treatment technologies including fractionated 3-d conformal radiotherapy, intensity modulated radiation therapy and recently proton therapy are able to precisely cover the target while preserving surrounding tissue,Tumour controls between 80 and in access of 90 % can be achieved. Alternative treatments consisting of radiosurgery, intracavitary application of isotopes and brachytherapy also offer an acceptable tumour control and might be given in selected cases. More research is needed to establish the role of each treatment modality.

  20. Towards Automatic Decentralized Control Structure Selection

    DEFF Research Database (Denmark)

    for decentralized control is determined automatically, and the resulting decentralized control structure is automatically tuned using standard techniques. Dynamic simulation of the resulting process system gives immediate feedback to the process design engineer regarding practical operability of the process......A subtask in integration of design and control of chemical processes is the selection of a control structure. Automating the selection of the control structure enables sequential integration of process and controld esign. As soon as the process is specified or computed, a structure....... The control structure selection problem is formulated as a special MILP employing cost coefficients which are computed using Parseval's theorem combined with RGA and IMC concepts. This approach enables selection and tuning of large-scale plant-wide decentralized controllers through efficient combination...

  1. Radiation Protection and Control Act, 1982, No. 47 of 1985

    International Nuclear Information System (INIS)

    1985-01-01

    These regulations provide for the control, administration, possession and use of radiating substances and irradiating apparatus. They contain detailed provisions concerning the licensing, sale, registration and maintenance of irradiating apparatus and radioactive substances. Provisions address the therapeutic and research purposes of radioactive substances and irradiating apparatus, as well as requirements for monitoring, record-keeping and medical examinations. Also included are detailed procedures for radiation accidents and emergencies. These Regulations revoke the Radioactive Substances and Irradiating Apparatus Regulations, 1962, and the Ionizing Radiation (radioactive ores) Regulations, 1982. (NEA) [fr

  2. Radiative heat transfer in honeycomb structures-New simple analytical and numerical approaches

    International Nuclear Information System (INIS)

    Baillis, D; Coquard, R; Randrianalisoa, J

    2012-01-01

    Porous Honeycomb Structures present the interest of combining, at the same time, high thermal insulating properties, low density and sufficient mechanical resistance. However, their thermal properties remain relatively unexplored. The aim of this study is the modelling of the combined heat transfer and especially radiative heat transfer through this type of anisotropic porous material. The equivalent radiative properties of the material are determined using ray-tracing procedures inside the honeycomb porous structure. From computational ray-tracing results, simple new analytical relations have been deduced. These useful analytical relations permit to determine radiative properties such as extinction, absorption and scattering coefficients and phase function functions of cell dimensions and optical properties of cell walls. The radiative properties of honeycomb material strongly depend on the direction of propagation. From the radiative properties computed, we have estimated the radiative heat flux passing through slabs of honeycomb core materials submitted to a 1-D temperature difference between a hot and a cold plate. We have compared numerical results obtained from Discrete Ordinate Method with analytical results obtained from Rosseland-Deissler approximation. This approximation is usually used in the case of isotropic materials. We have extended it to anisotropic honeycomb materials. Indeed a mean over incident directions of Rosseland extinction coefficient is proposed. Results tend to show that Rosseland-Deissler extended approximation can be used as a first approximation. Deviation on radiative conductivity obtained from Rosseland-Deissler approximation and from the Discrete Ordinated Method are lower than 6.7% for all the cases studied.

  3. The present condition of the radiation safety control education in training schools for radiological technologists

    International Nuclear Information System (INIS)

    Takahashi, Yasuyuki; Saito, Kyoko; Hirai, Shoko; Igarashi, Hiroshi; Negishi, Tooru; Hirano, Kunihiro; Kawaharada, Yasuhiro

    2010-01-01

    We made a detailed study on the course of study in radiation safety control prescribed on March 28, 2003. Questionnaires were sent to 39 training schools for radiological technology, to which 66.7% replied (26/39). Subjects on radiation safety control must include knowledge and technology in both radiation control and medical safety. The contents for instruction of radiation control were in accordance with those given in the traditional program; however, some discrepancies were found in the contents of medical safety. As medical safety, emphasized by the revised Medical Service Law, is regarded as very important by many hospitals, safety control education that include medical ethics should be required as part of the curriculum in the training schools for radiological technologists. (author)

  4. An Evaluation on Radiation Shielding and Activation Properties of ISOL-bunker Structural Materials for Radiation Safety in RAON Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Hyun; Kim, Song Hyun; Woo, Myeong Hyeon; Lee, Jae Yong; Kim, Jong Woo; Shin, Chang Ho [Hanyang University, Seoul (Korea, Republic of); Nam, Shin Woo [Institute for Basic Science, Daejeon (Korea, Republic of)

    2015-10-15

    RAON heavy ion accelerator has been designed by the Institute for Basic Science (IBS). ISOL is one of RAON facilities to generate and separate rare isotopes. For generating rare isotopes, high intensity proton beam, which has 70 MeV energy, is induced into UCx target. From this reaction, lots of neutrons are concomitantly generated. To meet our design goal, it was required that the structural material of ISOL-bunker should be carefully selected. In this study, to select the structural material which has lower activation property with higher performance for radiation shielding, following aspects were evaluated: (i) residual dose, (ii) radioactive wastes, and (iii) shielding performance in ISOL-bunker. In this study, to effectively design the radiation shielding of the RAON ISOL-bunker, two methods were proposed. No.1 strategy is a method to replace the normal concrete to specific concretes. No.2 strategy is to design dual-layer radiation shields that a specific shielding material is located inner side of the normal concrete. Using the strategies, performance evaluations were evaluated for three aspects, which are residual dose, radioactive waste, and prompt radiation. The results show that the residual radiation can be effectively reduced using B{sub 4}C, borated polyethylene and polyethylene with No.2 strategy. Also, the colemanite concrete and B{sub 4}C shielding give a good ability to reduce the radioactive wastes.

  5. Application of Advanced Radiation Shielding Materials to Inflatable Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovation is a weight-optimized, inflatable structure that incorporates radiation shielding materials into its construction, for use as a habitation module or...

  6. Control of sources of ionizing radiation in Lithuania

    Energy Technology Data Exchange (ETDEWEB)

    Mastauskas, Albinas; Ziliukas, Julius; Morkunas, Gendrutis [Radiation Protection Centre, Vilnius (Lithuania)

    1997-12-31

    Aspects connected with regulatory control of radioactive sources in Lithuania, such as keeping of the computer-based registry, investigation of arrested illegal radioactive material, decision making, control of users of radioactive sources are discussed. Most of the sources of ionizing radiation are smoke detectors and x-ray equipment. Potentially most dangerous sources (both sealed and unsealed) of therapy and industry are also presented 2 refs., 2 tabs.; e-mail: rsc at post.omnitel.net

  7. Japanese structure survey of radiation oncology in 2007 with special reference to designated cancer care hospitals

    International Nuclear Information System (INIS)

    Numasaki, Hodaka; Shibuya, Hitoshi; Nishio, Masamichi

    2011-01-01

    Background and Purpose: The structure of radiation oncology in designated cancer care hospitals in Japan was investigated in terms of equipment, personnel, patient load, and geographic distribution. The effect of changes in the health care policy in Japan on radiotherapy structure was also examined. Material and Methods: The Japanese Society of Therapeutic Radiology and Oncology surveyed the national structure of radiation oncology in 2007. The structures of 349 designated cancer care hospitals and 372 other radiotherapy facilities were compared. Results: Respective findings for equipment and personnel at designated cancer care hospitals and other facilities included the following: linear accelerators/facility: 1.3 and 1.0; annual patients/linear accelerator: 296.5 and 175.0; and annual patient load/full-time equivalent radiation oncologist was 237.0 and 273.3, respectively. Geographically, the number of designated cancer care hospitals was associated with population size. Conclusion: The structure of radiation oncology in Japan in terms of equipment, especially for designated cancer care hospitals, was as mature as that in European countries and the United States, even though the medical costs in relation to GDP in Japan are lower. There is still a shortage of manpower. The survey data proved to be important to fully understand the radiation oncology medical care system in Japan. (orig.)

  8. Optical Coating Performance and Thermal Structure Design for Heat Reflectors of JWST Electronic Control Unit

    Science.gov (United States)

    Quijada, Manuel A.; Threat, Felix; Garrison, Matt; Perrygo, Chuck; Bousquet, Robert; Rashford, Robert

    2008-01-01

    The James Webb Space Telescope (JWST) consists of an infrared-optimized Optical Telescope Element (OTE) that is cooled down to 40 degrees Kelvin. A second adjacent component to the OTE is the Integrated Science Instrument Module, or ISIM. This module includes the electronic compartment, which provides the mounting surfaces and ambient thermally controlled environment for the instrument control electronics. Dissipating the 200 watts generated from the ISIM structure away from the OTE is of paramount importance so that the spacecraft's own heat does not interfere with the infrared light detected from distant cosmic sources. This technical challenge is overcome by a thermal subsystem unit that provides passive cooling to the ISIM control electronics. The proposed design of this thermal radiator consists of a lightweight structure made out of composite materials and low-emittance metal coatings. In this paper, we will present characterizations of the coating emittance, bidirectional reflectance, and mechanical structure design that will affect the performance of this passive cooling system.

  9. Medical management of radiation safety and control of ionizing radiation sources in Armenia

    International Nuclear Information System (INIS)

    Hovhannisyan, N.M.

    1998-01-01

    The events of the last 10 years, Spitak earthquake (1988) and collapse of the former USSR brought forth the changes of the political situation in Armenia and significant disorder in economy, industry, relations, including the radiation safety (RS) and control of the organization of the activities connected with the ionizing radiation sources (IRSs). In 1989 the Armenian Nuclear Power Plant was shut down, and in 1994 it was restarted. In Armenia there are about 750 X-ray rooms, 10 radionuclide diagnostic laboratories, 20 gamma and X-ray units; 95 enterprises in industry, science and technology use the IRSs with different purposes, there are 5 electron particle accelerators of different power capacity. About 6,000 individuals have constant contact to IRS: the roentgenologists, radiologists, the staff of NPP, accelerators, etc. Besides, more than 3,000 liquidators of the Chernobyl NPP disaster live in Armenia. Nowadays, the precise infrastructure of RS is established in Armenia. The regulating body is the 'State Atom Authority', performing the control, coordination and licensing of both enterprises and specialists. Ministry of Health Ministry of Internal Affairs, Ministry of Ecology perform the control of IRSs' delivery into the Republic of Armenia and then their proper use and waste disposal in Armenia. (author)

  10. A study for the structural and functional regulation of chaperon protein by radiation

    International Nuclear Information System (INIS)

    Lee, Seung Sik; Chung, Byung Yeoup; Kim, Jin Hong

    2011-01-01

    The purpose of the this project provides new application areas for radiation technology for improvement of protein activities using radiation through the structural changes and functional regulations of molecular chaperon. Research scope includes 1) isolation of molecular chaperon proteins related radiation response from Psedomonads and purification of recombinant protein from E. coli., 2) the establishment of effective irradiation dose for the structural changes of chaperon protein, 3) analysis of the structural and functional changes of molecular chaperon by gamma irradiation. Main results are as follow: the chaperon activities of 2-Cys peroxiredxin show the maximum (about 3 times) at 15-30 kGy of gamma irradiation, but they were reduced greater than 30 kGy of gamma rays: the peroxidase activities show a tendency to decrease with increasing gamma irradiation: the structural change of peroxiredoxin (PP1084 and PA3529) by gamma irradiation (the formation of low molecular weight complexes or fragmentation of peroxiredoxin by gamma irradiation, the increase of beta-sheet and random coil by gamma irradiation and the decrease of alpha-helix and turn by gamma irradiation, and increased chaperon activity is related with increased hydrophobicity)

  11. Recent developments in radiation field control technology

    International Nuclear Information System (INIS)

    Wood, C.J.

    1995-01-01

    The U.S. nuclear power industry has been remarkably successful in reducing worker radiation exposures over the past ten years. There has been over a fourfold reduction in the person-rem incurred for each MW.year of electric power generated: from 1.8 in 1980, to only 0.39 person-rems in 1991 and 1992. Preliminary data for 1993 are even lower: approximately 0.37 person-rem.MW.year. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in ICRP 60 and there will be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts with be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the industry goals for 1995. Reducing out-of-core radiation fields offer the best chance of continuing the downward trend in exposures. To assist utilities select the most economic technology for their specific plants, EPRI has published a manual capturing worldwide operating experience with radiation-field control techniques (TR-100265). No one method will suffice, but implementing suitable combinations from this collection will enable utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: outages are shorter, manpower requirements are reduced and work quality is improved. Despite the up front costs, the benefits over the following 1-3 years typically outweigh the expenses

  12. Recent developments in radiation field control technology

    Energy Technology Data Exchange (ETDEWEB)

    Wood, C.J. [Electric Power Research Institute, Palo Alto, CA (United States)

    1995-03-01

    The U.S. nuclear power industry has been remarkably successful in reducing worker radiation exposures over the past ten years. There has been over a fourfold reduction in the person-rem incurred for each MW.year of electric power generated: from 1.8 in 1980, to only 0.39 person-rems in 1991 and 1992. Preliminary data for 1993 are even lower: approximately 0.37 person-rem.MW.year. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in ICRP 60 and there will be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts with be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the industry goals for 1995. Reducing out-of-core radiation fields offer the best chance of continuing the downward trend in exposures. To assist utilities select the most economic technology for their specific plants, EPRI has published a manual capturing worldwide operating experience with radiation-field control techniques (TR-100265). No one method will suffice, but implementing suitable combinations from this collection will enable utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: outages are shorter, manpower requirements are reduced and work quality is improved. Despite the up front costs, the benefits over the following 1-3 years typically outweigh the expenses.

  13. RITRACKS: A Software for Simulation of Stochastic Radiation Track Structure, Micro and Nanodosimetry, Radiation Chemistry and DNA Damage for Heavy Ions

    Science.gov (United States)

    Plante, I; Wu, H

    2014-01-01

    The code RITRACKS (Relativistic Ion Tracks) has been developed over the last few years at the NASA Johnson Space Center to simulate the effects of ionizing radiations at the microscopic scale, to understand the effects of space radiation at the biological level. The fundamental part of this code is the stochastic simulation of radiation track structure of heavy ions, an important component of space radiations. The code can calculate many relevant quantities such as the radial dose, voxel dose, and may also be used to calculate the dose in spherical and cylindrical targets of various sizes. Recently, we have incorporated DNA structure and damage simulations at the molecular scale in RITRACKS. The direct effect of radiations is simulated by introducing a slight modification of the existing particle transport algorithms, using the Binary-Encounter-Bethe model of ionization cross sections for each molecular orbitals of DNA. The simulation of radiation chemistry is done by a step-by-step diffusion-reaction program based on the Green's functions of the diffusion equation]. This approach is also used to simulate the indirect effect of ionizing radiation on DNA. The software can be installed independently on PC and tablets using the Windows operating system and does not require any coding from the user. It includes a Graphic User Interface (GUI) and a 3D OpenGL visualization interface. The calculations are executed simultaneously (in parallel) on multiple CPUs. The main features of the software will be presented.

  14. A study on enforcement effects of radiation safety control regulations for diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Sung, Mo IL; Park, Myeong Hwan; Kwon, Duk Moon; Lee, Joon IL

    1999-01-01

    The purposes of this study are to analyze the realities after enforcements of safety control regulations for diagnostic X-ray equipment and to suggest means for an improvement of low radiation safety control. A questionnaire survey for medical radiologic technologists was carried out to determine enforcement effects of the safety control regulations. The results of analysis from the survey are as follows. That is, most of he respondents realized the importance of the radiation safety control system, but about a half of them revealed that regulations were not well observed in accordance with their purposes. Only 43.9 percent of the respondents took an active part in quality control of radiation. And responsibility, sex, age, and knowledge for safety control were important indicators for observations of the regulations. Training for the safety control regulations are needed to ensure safety control and proper usage of diagnostic X-ray equipment. And management of organizations using diagnostic X-ray equipment have to understand and stress the importance of radiation safety control system. (author)

  15. Genetic algorithms for optimal design and control of adaptive structures

    CERN Document Server

    Ribeiro, R; Dias-Rodrigues, J; Vaz, M

    2000-01-01

    Future High Energy Physics experiments require the use of light and stable structures to support their most precise radiation detection elements. These large structures must be light, highly stable, stiff and radiation tolerant in an environment where external vibrations, high radiation levels, material aging, temperature and humidity gradients are not negligible. Unforeseen factors and the unknown result of the coupling of environmental conditions, together with external vibrations, may affect the position stability of the detectors and their support structures compromising their physics performance. Careful optimization of static and dynamic behavior must be an essential part of the engineering design. Genetic Algorithms ( GA) belong to the group of probabilistic algorithms, combining elements of direct and stochastic search. They are more robust than existing directed search methods with the advantage of maintaining a population of potential solutions. There is a class of optimization problems for which Ge...

  16. Nuclear resonant scattering of synchrotron radiation: Applications in magnetism of layered structures

    International Nuclear Information System (INIS)

    Schlage, Kai; Röhlsberger, Ralf

    2013-01-01

    Highlights: •Depth-resolved determination of magnetic spin structures. •Isotopic probe layers allow for probing selected depths in the sample. •High sensitivity to magnetic domain patterns via diffuse scattering. -- Abstract: Nuclear resonant scattering of synchrotron radiation has become an established tool within condensed-matter research. Synchrotron radiation with its outstanding brilliance, transverse coherence and polarization has opened this field for many unique studies, for fundamental research in the field of light-matter interaction as well as for materials science. This applies in particular for the electronic and magnetic structure of very small sample volumes like micro- and nano-structures and samples under extreme conditions of temperature and pressure. This article is devoted to the application of the technique to nanomagnetic systems such as thin films and multilayers. After a basic introduction into the method, a number of our experiments are presented to illustrate how magnetic spin structures within such layer systems can be revealed

  17. [Morphological structure of rat epiphysis exposed to electromagnetic radiation from communication devices].

    Science.gov (United States)

    Yashchenko, S G; Rybalko, S Yu

    Pineal gland is one of the most important components of homeostasis - the supporting system of the body. It participates in the launch of stress responses, restriction of their development, prevention of adverse effects on the body. There was proved an impact of electromagnetic radiation on the epiphysis. However, morphological changes in the epiphysis under exposure to electromagnetic radiation of modern communication devices are studied not sufficiently. For the time present the population is daily exposed to electromagnetic radiation, including local irradiation on the brain. These date determined the task of this research - the study of the structure of rat pineal gland under the exposure to electromagnetic radiation from personal computers and mobile phones. These date determined the task of this research - the study of the structure of rat pineal gland under the exposure to electromagnetic radiation from personal computers and mobile phones. Performed transmission electron microscopy revealed signs of degeneration of dark and light pinealocytes. These signs were manifested in the development of a complex of general and specific morphological changes. There was revealed the appearance of signs of aging and depletion transmission electron microscopy both in light and dark pinealocytes. These signs were manifested in the accumulation of lipofuscin granules and electron-dense "brain sand", the disappearance of nucleoli, cytoplasm vacuolization and mitochondrial cristae enlightenment.

  18. 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

  19. 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

  20. 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

  1. Radiation-Induced Topological Disorder in Irradiated Network Structures

    International Nuclear Information System (INIS)

    Hobbs, Linn W.

    2002-12-01

    This report summarizes results of a research program investigating the fundamental principles underlying the phenomenon of topological disordering in a radiation environment. This phenomenon is known popularly as amorphization, but is more formally described as a process of radiation-induced structural arrangement that leads in crystals to loss of long-range translational and orientational correlations and in glasses to analogous alteration of connectivity topologies. The program focus has been on a set compound ceramic solids with directed bonding exhibiting structures that can be described as networks. Such solids include SiO2, Si3N4, SiC, which are of interest to applications in fusion energy production, nuclear waste storage, and device manufacture involving ion implantation or use in radiation fields. The principal investigative tools comprise a combination of experimental diffraction-based techniques, topological modeling, and molecular-dynamics simulations that have proven a rich source of information in the preceding support period. The results from the present support period fall into three task areas. The first comprises enumeration of the rigidity constraints applying to (1) more complex ceramic structures (such as rutile, corundum, spinel and olivine structures) that exhibit multiply polytopic coordination units or multiple modes of connecting such units, (2) elemental solids (such as graphite, silicon and diamond) for which a correct choice of polytope is necessary to achieve correct representation of the constraints, and (3) compounds (such as spinel and silicon carbide) that exhibit chemical disorder on one or several sublattices. With correct identification of the topological constraints, a unique correlation is shown to exist between constraint and amorphizability which demonstrates that amorphization occurs at a critical constraint loss. The second task involves the application of molecular dynamics (MD) methods to topologically-generated models

  2. A Self-Assessment of the Effectiveness to Control Radiation Sources in Sierra Leone

    Energy Technology Data Exchange (ETDEWEB)

    Bun-Tejan, Umaru Remilekun [KAIST, Daejeon (Korea, Republic of); Lee, Byung Soo [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-10-15

    There is an urgent need to effectively control sources of ionizing radiation. Sources of ionizing radiation pose serious occupational, public health, and environmental consequences, if not properly controlled. The government of Sierra Leone knows the importance of controlling these sources of ionizing radiation and of establishing an independent Nuclear Safety Infrastructure. Sierra Leone has no nuclear facilities but, it is rapidly developing its infrastructure in order to obtain nuclear technology. However, the regulatory effectiveness in controlling radiation risk is essential for the International Atomic Energy Agency to allow the transfer of nuclear technology. For this reason, this study will evaluate the status of the regulatory authority in Sierra Leone to control radiation risk. The International Atomic Energy Agency (IAEA) review mission to Sierra Leone found that the RPBA did not give sufficient enforcement powers to the Board Secretariat. The research evaluated the status of the regulatory authority of Sierra Leone. The status of the regulatory authority was evaluated against several parameters including management systems, regulatory processes, authorization, inspection, and enforcement. The ability to effectively control ionizing radiation sources depends on the status of the regulatory body. The Integrated Regulatory Review Service Report on Sierra Leone led us to infer that there is a need for the regulatory authority to rapidly improve its ability to control ionizing radiation sources in the country. The findings however, revealed that the overall strengths of the regulatory body in Sierra Leone slightly outnumber the weaknesses. Management systems have a ratio of 0.85:1 of strengths to weaknesses. This ratio makes management systems the weakest parameter evaluated. Thus there is need for stronger collaboration between management staff. The Regulatory processes have a ratio of 1.3:1, authorizations have a ratio of 4.3:1, inspections have ratio of 2

  3. A Self-Assessment of the Effectiveness to Control Radiation Sources in Sierra Leone

    International Nuclear Information System (INIS)

    Bun-Tejan, Umaru Remilekun; Lee, Byung Soo

    2016-01-01

    There is an urgent need to effectively control sources of ionizing radiation. Sources of ionizing radiation pose serious occupational, public health, and environmental consequences, if not properly controlled. The government of Sierra Leone knows the importance of controlling these sources of ionizing radiation and of establishing an independent Nuclear Safety Infrastructure. Sierra Leone has no nuclear facilities but, it is rapidly developing its infrastructure in order to obtain nuclear technology. However, the regulatory effectiveness in controlling radiation risk is essential for the International Atomic Energy Agency to allow the transfer of nuclear technology. For this reason, this study will evaluate the status of the regulatory authority in Sierra Leone to control radiation risk. The International Atomic Energy Agency (IAEA) review mission to Sierra Leone found that the RPBA did not give sufficient enforcement powers to the Board Secretariat. The research evaluated the status of the regulatory authority of Sierra Leone. The status of the regulatory authority was evaluated against several parameters including management systems, regulatory processes, authorization, inspection, and enforcement. The ability to effectively control ionizing radiation sources depends on the status of the regulatory body. The Integrated Regulatory Review Service Report on Sierra Leone led us to infer that there is a need for the regulatory authority to rapidly improve its ability to control ionizing radiation sources in the country. The findings however, revealed that the overall strengths of the regulatory body in Sierra Leone slightly outnumber the weaknesses. Management systems have a ratio of 0.85:1 of strengths to weaknesses. This ratio makes management systems the weakest parameter evaluated. Thus there is need for stronger collaboration between management staff. The Regulatory processes have a ratio of 1.3:1, authorizations have a ratio of 4.3:1, inspections have ratio of 2

  4. Radiation control of salmonellae in food and feed products

    Energy Technology Data Exchange (ETDEWEB)

    1963-12-01

    A panel on radiation control of harmful organisms, primarily Salmonella, transmitted by food and feed products was convened by the International Atomic Energy Agency (IAEA) in December 1962. Transmission of pests and diseases is a consequence of the growth in world trade. As most food and feed products are distributed from large centralized plants, primary infection at such centers can lead to the spread of diseases over wide areas and among a great number of people. The main purpose of this panel was to advise the Director General of the International Atomic Energy Agency as to how the Agency could assist in solving the problem of bacterial infection of food and animal feeds. The panel meeting was attended by twelve experts on public health problems, food hygiene, radiomicrobiology and radiation technology and by representatives from the Food and Agriculture Organization of the United Nations (FAO) and the World Health organization (WHO). In view of the seriousness of the spread of Salmonella and other organisms and the fact that radiation control seems to offer significant advantages in a number of cases, it was recommended by the panel members that the Agency publish the papers presented. Refs, figs and tabs.

  5. Radiation control of salmonellae in food and feed products

    International Nuclear Information System (INIS)

    1963-01-01

    A panel on radiation control of harmful organisms, primarily Salmonella, transmitted by food and feed products was convened by the International Atomic Energy Agency (IAEA) in December 1962. Transmission of pests and diseases is a consequence of the growth in world trade. As most food and feed products are distributed from large centralized plants, primary infection at such centers can lead to the spread of diseases over wide areas and among a great number of people. The main purpose of this panel was to advise the Director General of the International Atomic Energy Agency as to how the Agency could assist in solving the problem of bacterial infection of food and animal feeds. The panel meeting was attended by twelve experts on public health problems, food hygiene, radiomicrobiology and radiation technology and by representatives from the Food and Agriculture Organization of the United Nations (FAO) and the World Health organization (WHO). In view of the seriousness of the spread of Salmonella and other organisms and the fact that radiation control seems to offer significant advantages in a number of cases, it was recommended by the panel members that the Agency publish the papers presented. Refs, figs and tabs

  6. The Automatic Radiation Control System Of The Inr Linear Accelerator (troitsk).

    CERN Document Server

    Grachev, M I; Kuptsov, S I; Peleshko, V N; Shishkin, K I; Shmelev, M O; Skorkin, V M

    2004-01-01

    The radiation monitor system (RMS) at accelerator INR is a part of radiation safety system of experimental complex INR. RMS is intended for continuous monitoring of radiation field behind biological protection of linear accelerator INR with the personnel dose control and alarm purposes. Three-level system RMS consists of the operator computer, microprocessor data acquisition modules and networks of UDBN-02R neutron detectors and BDRC-01P photon detectors, located inside and behind biological protection of the accelerator (fig. 1).

  7. Radiation control system of nuclear power plants

    International Nuclear Information System (INIS)

    Kapisovsky, V.; Kosa, M.; Melichar, Z.; Moravek, J.; Jancik, O.

    1977-01-01

    The SYRAK system is being developed for in-service radiation control of the V-1 nuclear power plant. Its basic components are an EC 1010 computer, a CAMAC system and communication means. The in-service release of radionuclides is measured by fuel can failure detection, by monitoring rare gases in the coolant, by gamma spectrometric coolant monitoring and by iodine isotopes monitoring in stack disposal. (O.K.)

  8. Radiation Protection and Control Act 1982. No 49 of 1982

    International Nuclear Information System (INIS)

    1982-01-01

    This Act provides for radiation protection in the State of South Australia. It controls activities related to radioactive substances and irradiating apparatus and lays down a licensing system to this effect. The South Australia Health Commission is responsible for administering the Act and is advised by the Radiation Protection Committee created for this purpose. The powers and duties of both bodies are set out in detail. (NEA) [fr

  9. Radiation-induced structural changes. 3

    International Nuclear Information System (INIS)

    Kondo, Yasuhiro; Matsuyama, Tomochika; Ogasawara, Masaaki

    1993-05-01

    This meeting is the fourth of series meetings on the structural change in materials induced by ionizing radiation. The present meeting was organized to discuss specifically on the x-ray storage phosphors such as BaFBr:Eu 2+ or RbI x Br 1-x :Tl and to get a clear understanding of the present status of the research on the storage mechanisms, nature of the rare earth impurities, and the optical properties of BaFBr. It was also expected that all the participants became aware of unsolved problems in these storage materials and that some of them would start research work on the storage phosphors. Therefore this report was edited mainly to provide basic knowledge correlated with the storage phosphors and related phenomena rather than to report simply on the experimental results. (J.P.N.)

  10. The effect on radiation damage of structural material in a hybrid system by using a Monte Carlo radiation transport code

    International Nuclear Information System (INIS)

    Günay, Mehtap; Şarer, Başar; Kasap, Hızır

    2014-01-01

    Highlights: • The effects of some fluids on gas production rates in structural material were investigated. • The MCNPX-2.7.0 Monte Carlo code was used for three-dimensional calculations. • It was found that biggest contribution to gas production rates comes from Fe isotope of the. • The desirable values for 5% SFG-PuO 2 with respect to radiation damage were specified. - Abstract: In this study, the molten salt-heavy metal mixtures 99–95% Li20Sn80-1-5% SFG-Pu, 99–95% Li20Sn80-1-5% SFG-PuF4, 99-95% Li20Sn80-1-5% SFG-PuO2 were used as fluids. The fluids were used in the liquid first-wall, blanket and shield zones of the designed hybrid reactor system. 9Cr2WVTa ferritic steel with the width of 4 cm was used as the structural material. The parameters of radiation damage are proton, deuterium, tritium, He-3 and He-4 gas production rates. In this study, the effects of the selected fluid on the radiation damage, in terms of individual as well as total isotopes in the structural material, were investigated for 30 full power years (FPYs). Three-dimensional analyses were performed using the most recent version of the MCNPX-2.7.0 Monte Carlo radiation transport code and the ENDF/B-VII.0 nuclear data library

  11. Present status of standards relating to radiation control and protection

    International Nuclear Information System (INIS)

    Minami, Kentaro

    1996-01-01

    Japanese and international standards related to radiation control and radiation protective management are presented focusing on the forming condition, significance, current situation, and their relationship. Japanese Industrial Standards (JIS) is quite useful in the field of atomic energy as well as other fields in terms of optimization and rationalization of the management. JIS includes JIS Z 4001 Atomic Energy Terminology which corresponds to internationl standards ISO 921 Nuclear Glossary, and JIS Z 4005 Medical Radiation Terminology, covering about 500 articles, which corresponds to IEC 788 Medical Radiology-Terminology. The first standards regarding radiation protection was established in X-ray Film Badge, which is included in the field of personal dosimeter, in 1956. Currently, 36 JIS has been established in the field of radiation management dosimeter and 3 are under arrangement. As for radiation protective supplies, 9 JIS has been established so far. Before proposal of JIS, investigation had been conducted to improve, simplify, and standardize the standards of radiation dosimetric technique, dosimeters, dosimetric procedures, and improvement. In this article, the results of material surface contamination monitoring and body surface monitoring conducted in Atomic Energy Safety Association and Radiation Dosimetry Associationare reported, and ISO and IEC are also treated. (S.Y.)

  12. Experience in the development and practical use of working control levels for radiation safety

    International Nuclear Information System (INIS)

    Epishin, A.V.

    1981-01-01

    The experience of development and practical use of working control levels (WCL) of radiation safety in the Gorky region, is discussed. WCL are introduced by ''Radiation Safety Guides'' (RSG-76) and have great practical importance. Regional control levels of radiation safety are determined for certain types of operations implying radioactive hazard and differentiated according to the types of sources applied and types of operation. Dose rates, radioactive contamination of operating surfaces, skin, air and waste water are subject to normalization. Limits of individual radiation doses specified according to operation categories are included. 10 tables of regional WCL indices are developed [ru

  13. The actual state and problems of radiation control in medical facilities

    International Nuclear Information System (INIS)

    Kaneko, Masao

    1978-01-01

    Utilization of radiation was started in university hospitals, but recently, the established general inspections come to be very popular among general hospitals. Numerous kinds of nuclides are utilized for a number of purposes in university hospitals, while the kinds of nuclides utilized in general hospitals are quite limited. Concerning radiation safety control, film badge method is most popular among personal exposure control methods, while the combinations of film badge and pocket chamber methods, and film badge and TLD methods are also adopted. In many general hospitals, however, the exposure control tools are not equipped. Many kinds of safety control devices are installed for general controls. The laws so far mainly regulated the standards of buildings and installations, but did not specify the standard for accommodating RI-administered patients, and the preventive measures to secondary exposure and pollution, which often causes careless control. Therefore, the preventive measures to secondary injuries are required. (Kobatake, H.)

  14. Modeling of radiation heat transport in complex ladder-like structures placed in rectangular enclosures

    International Nuclear Information System (INIS)

    Unal, C.; Bohl, W.R.; Pasamehmetoglu, K.O.

    1999-01-01

    Complex ladder-like structures recently have been considered as the target design for accelerator applications. The decay heat, during a postulated beyond design-basis loss-of-coolant accident in the target where all normal and emergency cooling fails, is removed mainly by radiation heat transfer. Modeling of the radiation transport in complex ladder-like structures has several challenges and limitations when the standard net-radiation model is used. This paper proposes a simplified lumped, or 'hot-rung' model, that considers the worst elements and utilizes the standard net-radiation method. The net-radiation model would under-predict structure temperatures if surfaces were subject to non-uniform radiosity. The proposed model was assessed to suggest corrections to account for the non-uniform radiosity. The non-uniform radiosity effect causes the proposed hot-rung model to under-predict the center-rung temperatures by ∼4-74 C when all parametrics, including temperatures up to 1500 C, were considered. These temperatures are small. The proposed model predicted that an important effect of decreasing the emissivity was smoothing of non-isothermal effects. The radiosity effects are more pronounced when there are strong temperature gradients. Uniform rung temperatures tend to decrease the radiosity effects. We concluded that a relatively simple model that is conservative with respect to radiosity effects could be developed. (orig.)

  15. Wavelength dispersive X-ray absorption fine structure imaging by parametric X-ray radiation

    International Nuclear Information System (INIS)

    Inagaki, Manabu; Sakai, Takeshi; Sato, Isamu; Hayakawa, Yasushi; Nogami, Kyoko; Tanaka, Toshinari; Hayakawa, Ken; Nakao, Keisuke

    2008-01-01

    The parametric X-ray radiation (PXR) generator system at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University is a monochromatic and coherent X-ray source with horizontal wavelength dispersion. The energy definition of the X-rays, which depends on the horizontal size of the incident electron beam on the generator target crystal, has been investigated experimentally by measuring the X-ray absorption near edge structure (XANES) spectra on Cu and CuO associated with conventional X-ray absorption imaging technique. The result demonstrated the controllability of the spectrum resolution of XANES by adjusting of the horizontal electron beam size on the target crystal. The XANES spectra were obtained with energy resolution of several eV at the narrowest case, which is in qualitative agreement with the energy definition of the PXR X-rays evaluated from geometrical consideration. The result also suggested that the wavelength dispersive X-ray absorption fine structure measurement associated with imaging technique is one of the promising applications of PXR. (author)

  16. The construction of standardised equipment expressly adapted to the different methods of radiation control; Realisation de materiel standardise specialement adapte aux divers modes de controle des radiations

    Energy Technology Data Exchange (ETDEWEB)

    Savouyaud, J; Menoux, A [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The authors show what general characteristics must have equipment designed for radiation control. This equipment must make possible the measurement of doses corresponding to 1/10 of the maximum permissible limit. It should be designed for a specific purpose, and finally it should be independent as far as possible. The authors review the different types of control which it is necessary to effect. (author) [French] Les auteurs indiquent quelles doivent etre les caracteristiques generales du materiel de controle des radiations. Ce materiel doit permettre l'appreciation de mesures correspondant au 1/10{sup e} des limites maximales admissibles. Il devrait etre concu pour une fonction determinee, enfin, il doit etre dans la mesure du possible, autonome. Les auteurs passent en revue les differents types de controle qu'il est necessaire de couvrir. (auteur)

  17. Is cosmic radiation exposure of air crew amenable to control?

    International Nuclear Information System (INIS)

    McEwan, A.C.

    1999-01-01

    ICRP Committee 4 currently has a Working Party on Cosmic Ray Exposure in Aircraft and Space Flight. It has assembled information on doses arising in aircraft and space flight and considered the appropriateness of the Commission's recommendations relating to air crew. A central issue is whether the exposures received should be considered amenable to control. Factors of relevance to the enhanced cosmic radiation exposure of air crew, and frequent fliers such as couriers, are doses to pregnant staff, the issue of controllability of doses, and the implementation of regulatory controls. It is concluded that while air crew in the current range of subsonic jet aircraft are exposed to enhanced levels of cosmic radiation, these exposures are not readily controllable nor likely to exceed about 6 mSv/y. The revised ICRP Recommendations in 1991 (ICRP 60) propose air crew be designated as occupationally exposed. However, none of the usual optimisation of dose actions associated with regulation of practices, such as classification of work areas and rules governing working procedures, can be implemented, and in practice the doses are not amenable to control. The International Basic Safety Standards therefore leave this designation to the judgement of national regulatory authorities. One requirement that stems from designation as occupational exposure is that of restriction of doses to pregnant women. Both from the points of view that it is questionable whether exposure of air crew can reasonably be considered to be amenable to control, and the magnitude of the risks from exposures incurred, there is little reason to invoke additional restrictions to limit exposures of pregnant air crew. Copyright (1999) Australasian Radiation Protection Society Inc

  18. Operation and radiation resistance of a FOXFET biasing structure for silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Laakso, M [Particle Detector Group, Fermilab, Batavia, IL (United States) Research Inst. for High Energy Physics (SEFT), Helsinski (Finland); Singh, P; Engels, E Jr; Shepard, J; Shepard, P F [Dept. of Physics and Astronomy, Univ. Pittsburgh, PA (United States)

    1993-03-01

    AC-coupled strip detectors biased with a FOXFET transistor structure have been studied. Measurement results for the basic operational characteristics of the FOXFET are presented together with a brief description of the physics underlying its operation. Radiation effects were studied using photons from a [sup 137]Cs source. Changes in the FOXFET characteristics as a function of radiation dose up to 1 Mrad are reported. Results about the effect of radiation on the noise from a FOXFET biased detector are discribed. (orig.).

  19. Operation and radiation resistance of a FOXFET biasing structure for silicon strip detectors

    International Nuclear Information System (INIS)

    Laakso, M.; Helsinki Univ.; Singh, P.; Engels, E. Jr.; Shepard, P.

    1992-02-01

    AC-coupled strip detectors biased with a FOXFET transistor structure have been studied. Measurement results for the basic operational characteristics of the FOXFET are presented together with a brief description of the physics underlying its operation. Radiation effects were studied using photons from a 137 Cs source. Changes in the FOXFET characteristics as a function of radiation dose up to 1 MRad are reported. Results about the effect of radiation on the noise from a FOXFET biased detector are described. 13 refs

  20. A micro-controller based palm-size radiation monitor

    International Nuclear Information System (INIS)

    Bhingare, R.R.; Bajaj, K.C.; Kannan, S.

    2001-01-01

    A micro-controller based, palm-size radiation monitor, PALMRAD, using a silicon P-N junction diode as a detector has been developed. It is useful for radiation protection monitoring during radiation emergency as well as radioactive source loading operations. Some of the features of PALMRAD developed are the use of a semiconductor diode as the detector, simultaneous display of integrated dose and dose rate on a 16-digit alpha numeric LCD display, measurable integrated dose range from 1 μSv to 5000 μSv and dose rate range from 1 mSv/h to 1,000 mSv/h, RS 232C serial interface for connection to a Personal Computer,-storage of integrated dose and dose rate readings, recall of stored readings on LCD display, presentable integrated dose alarm from 1 μSv to 5000 μSv and dose rate from 1 mSv/h to 1,000 mSv/h, battery status and memory status check during measurement, LCD display with LED back-lighting, etc. (author)

  1. Radiation Protection Group annual report (1997)

    International Nuclear Information System (INIS)

    Hoefert, M.

    1998-01-01

    The Annual Report of the Radiation Protection Group is intended to inform the Host State Authorities, as well as the CERN Management and staff, about the radiological situation at CERN during the year 1997. The structure of the present report follows that of previous years and has five sections. It presents the results of environmental radiation monitoring, gives information about the radiation control on the sites of the Organization, describes the radiation protection activities around the CERN accelerators, reports on personnel dosimetry, calibration and instrumentation, and briefly comments on the non-routine activities of the Radiation Protection Group

  2. Radiation Protection Group annual report (1996)

    International Nuclear Information System (INIS)

    Hoefert, M.

    1997-01-01

    The Annual Report of the Radiation Protection Group is intended to inform the Host State Authorities, as well as the CERN Management and staff, about the radiological situation at CERN during the year 1996. The structure of the present report follows that of previous years and has five sections. It presents the results of environmental radiation monitoring, gives information about the radiation control on the sites of the Organization, describes the radiation protection activities around the CERN accelerators, reports on personnel dosimetry, calibration and instrumentation, and briefly comments on the non-routine activities of the Radiation Protection Group

  3. Radiation Protection Group annual report (1998)

    International Nuclear Information System (INIS)

    Hoefert, M.

    1999-01-01

    The Annual Report of the Radiation Protection Group is intended to inform the Host State Authorities, as well as the CERN Management and staff, about the radiological situation at CERN during the year 1998. The structure of the present report follows that of previous years and has five sections. It presents the results of environmental radiation monitoring, gives information about the radiation control on the sites of the Organization, describes the radiation protection activities around the CERN accelerators, reports on personnel dosimetry, calibration and instrumentation, and briefly comments on the non-routine activities of the Radiation Protection Group

  4. Radiation Protection Group annual report (1996)

    Energy Technology Data Exchange (ETDEWEB)

    Hoefert, M [ed.

    1997-03-25

    The Annual Report of the Radiation Protection Group is intended to inform the Host State Authorities, as well as the CERN Management and staff, about the radiological situation at CERN during the year 1996. The structure of the present report follows that of previous years and has five sections. It presents the results of environmental radiation monitoring, gives information about the radiation control on the sites of the Organization, describes the radiation protection activities around the CERN accelerators, reports on personnel dosimetry, calibration and instrumentation, and briefly comments on the non-routine activities of the Radiation Protection Group.

  5. Radiation Protection Group annual report (1998)

    Energy Technology Data Exchange (ETDEWEB)

    Hoefert, M [ed.

    1999-04-15

    The Annual Report of the Radiation Protection Group is intended to inform the Host State Authorities, as well as the CERN Management and staff, about the radiological situation at CERN during the year 1998. The structure of the present report follows that of previous years and has five sections. It presents the results of environmental radiation monitoring, gives information about the radiation control on the sites of the Organization, describes the radiation protection activities around the CERN accelerators, reports on personnel dosimetry, calibration and instrumentation, and briefly comments on the non-routine activities of the Radiation Protection Group.

  6. Radiation Protection Group annual report (1997)

    Energy Technology Data Exchange (ETDEWEB)

    Hoefert, M [ed.

    1998-04-10

    The Annual Report of the Radiation Protection Group is intended to inform the Host State Authorities, as well as the CERN Management and staff, about the radiological situation at CERN during the year 1997. The structure of the present report follows that of previous years and has five sections. It presents the results of environmental radiation monitoring, gives information about the radiation control on the sites of the Organization, describes the radiation protection activities around the CERN accelerators, reports on personnel dosimetry, calibration and instrumentation, and briefly comments on the non-routine activities of the Radiation Protection Group.

  7. Radiation Protection Group annual report (1995)

    International Nuclear Information System (INIS)

    Hoefert, M.

    1996-01-01

    The Annual Report of the Radiation Protection Group is intended to inform the Host State Authorities, as well as the CERN Management and staff, about the radiological situation at CERN during the year 1995. The structure of the present report follows that of previous years and has five sections. It presents the results of environmental radiation monitoring, gives information about the radiation control on the sites of the Organization, describes the radiation protection activities around the CERN accelerators, reports on personnel dosimetry, calibration and instrumentation, and briefly comments on the non-routine activities of the Radiation Protection Group

  8. Radiation exposure monitoring and control in front-end fuel cycle facilities

    International Nuclear Information System (INIS)

    Khan, A.H.

    2003-01-01

    The front end nuclear fuel cycle facilities presently operational in India are the mining and processing of beach mineral sands along the southern coast of Kerala, Tamilnadu and Orissa, mining and processing of uranium ore in Singhbhum-East in Jharkhand and refining and fuel fabrication at Hyderabad and Trombay. Dedicated Health Physics Units set up at each site regularly carry out in-plant and personnel monitoring to ensure safe working conditions and evaluate radiation exposure of workers and advise appropriate control measures. External gamma radiation, radon, thoron, their progeny and airborne long-lived activity due to radioactive dust are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the plant and personal monitoring data. Provision of adequate ventilation, control of dust and spillage of active solutions, prompt decontamination, use of personal protective appliances and worker education are the key factors in keeping the doses to the workers well within the regulatory limits. It has been observed that the total radiation dose to workers has been well below 20 mSv.y - 1 at all stages of operations. The monitoring methodologies and summary of radiation exposure data for different facilities during the last few years are presented in the paper. (author)

  9. Relationship between chromatin structure and sensitivity to molecularly targeted auger electron radiation therapy.

    NARCIS (Netherlands)

    Terry, S.Y.A.; Vallis, K.A.

    2012-01-01

    PURPOSE: The open structure of euchromatin renders it susceptible to DNA damage by ionizing radiation (IR) compared with compact heterochromatin. The effect of chromatin configuration on the efficacy of Auger electron radiotherapy was investigated. METHODS AND MATERIALS: Chromatin structure was

  10. Radiation as a microbiological contamination control of drugs, cosmetics and medical devices

    International Nuclear Information System (INIS)

    Ishizeki, Chuichi

    1985-01-01

    This paper deals with current status of radiation sterilization or disinfection of drugs, cosmetics, their materials, and medical devices, and with quality control as a tool for securing microbiological safety, especially current status of sterilization tests. Ointment containing tetracyclin, steroid hormones, gelatin, and enzymes are presented as drug samples to be irradiated, and explanations for radiation sterilization of these drugs are provided. An outline of the application of radiation in cosmetics and medical devices is given. Issues are also provided from the viewpoint of safey and effectiveness of radiation sterilization. (Namekawa, K.)

  11. Research on radiation control as presented in the Medical Service Law

    International Nuclear Information System (INIS)

    Takahashi, Yasuyuki; Shinohara, Hisashi; Narimatsu, Takaki; Kawamata, Isao; Miguchi, Hiroshi; Sunayashiki, Tadashi.

    1997-01-01

    We considered it important to determine how each municipal government interprets and promulgates the Medical Service Law as it affects the field of radiology and procedures such as general X-ray diagnosis, CT, RI, radiation therapy and MR imaging. Only the government administrative segment referred to as the medical supervisory body can observe, control and generally administer front-line medical sites such as hospitals and clinics. This administrative body should have better public health care as its objective and should be able to adapt to changes in technology and the environment. We consider that, under the current climate of rapid technological change, medical supervision cannot be effective unless teams of specialists from each field are involved in administrative guidance. With the goal of achieving optimal and effective use of medical radiology, a questionnaire survey was done to gather information. Two questions were raised: Is there sufficient interaction between public medical supervisors and radiologists? and how well do people on the front lines at medical sites understand the current control structure? (author)

  12. CRIE, radiation control in children in Extremadura (Spain); CRIE, un control de radiacion en la edad infantil en Extremadura

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Llanos, R.; Jimenez Matas, A.; Gallardo Berrocal, M. C.; Villalobos Avila, M. A.

    2006-07-01

    The Department of Health of Extremadura, runs the Programme for the Control of Diagnostic Radiation Doses received by Children in Extremadura (CRIE in Spanish). This Programme aims to improve the quality of the medical assistance for children in our region. One way to guarantee this quality is to control the use of ionizing radiations in explorations for diagnostic and therapeutic purposes. This radiations must be justified and done in the appropriate facilities, using the lowest dose level. to achieve this goal, the CRIE Programme warns the following people about the risks that radiation can entail: Responsible people (parents or tutors). People prescribing diagnostic tests (doctors) Professionals who do the tests (radiologists, nuclear medicine specialists, technicians and nursing personnel). The control is carried out with the help of the CRIE card, assigned to every child under 14, on which every radiologic exploration and its date must be recorded. The CRIE cards are available in the doctors surgeries of the hospitals, in the maternity wards and in the Radiodiagnosis, Radiotherapy and Nuclear Medicine Services. (Author)

  13. Effect of Electromagnetic Radiation Emitted from A Mobile Phone Station on Biochemical and Histological Structure of Some Rat Organs

    International Nuclear Information System (INIS)

    Lotfi, S.A.

    2011-01-01

    This study was carried out to investigate the effects of electromagnetic radiations (EMR), especially radio frequency (RF), which arises from mobile phone station on some parameter in serum and histological structure of some organs in male albino rats exposed to short (15 days) and long (30 days) periods. The long time exposure of the electromagnetic radiations can induce significant increase in the levels of testosterone, creatinine, urea and uric acid in the two exposure groups (15 and 30 days), while the serum total protein, albumin and globulin were decreased significantly after the long time of exposure as compared with control. The microscopic examination of liver, kidney and testes tissues revealed destruction and atrophy of cells in rats exposed to RF for 15 and 30 days. In conclusion, long term exposure of mobile phones station (EMR) induced harmful effects on blood parameter and histological structure of liver, kidney and testes tissues of rats.

  14. Non-ionizing radiation protection training manual for radiation control. Lectures, demonstrations, laboratories and tours on the course on non-ionizing radiations. Final report

    International Nuclear Information System (INIS)

    Morgan, K.Z.; Burkhart, R.L.

    1976-03-01

    In late 1974, consultation with the National Training Coordination Committee of the Conference of Radiation Control Program Directors determined that State personnel needed training in order to fulfill their responsibility with respect to the growing number of non-ionizing radiation sources. A contract was awarded to the Georgia Institute of Technology to develop materials for a training program on non-ionizing radiation protection, pilot test these materials in a two-week presentation for Federal, State, and local government health personnel, and revise the materials as needed to produce a self-contained training manual. The materials were pilot-tested in March 1976, and then revised to provide the final manual. The course consists of three parts (1) general discussions of basic principles, properties, propagation and behavior of all types of non-ionizing radiations (2) an indepth study of all types and applications of coherent (laser) radiations, and (3) a study of ultraviolet, infrared, microwave, r.f., longwave and mechanical radiations as they may be used to have applications in hospitals and other medical institutions

  15. Heat resistant/radiation resistant cable and incore structure test device for FBR type reactor

    International Nuclear Information System (INIS)

    Tanimoto, Hajime; Shiono, Takeo; Sato, Yoshimi; Ito, Kazumi; Sudo, Shigeaki; Saito, Shin-ichi; Mitsui, Hisayasu.

    1995-01-01

    A heat resistant/radiation resistant coaxial cable of the present invention comprises an insulation layer, an outer conductor and a protection cover in this order on an inner conductor, in which the insulation layer comprises thermoplastic polyimide. In the same manner, a heat resistant/radiation resistant power cable has an insulation layer comprising thermoplastic polyimide on a conductor, and is provided with a protection cover comprising braid of alamide fibers at the outer circumference of the insulation layer. An incore structure test device for an FBR type reactor comprises the heat resistant/radiation resistant coaxial cable and/or the power cable. The thermoplastic polyimide can be extrusion molded, and has excellent radiation resistant by the extrusion, as well as has high dielectric withstand voltage, good flexibility and electric characteristics at high temperature. The incore structure test device for the FBR type reactor of the present invention comprising such a cable has excellent reliability and durability. (T.M.)

  16. Control of ionising radiation - a UK viewpoint

    International Nuclear Information System (INIS)

    Shrimpton, P.C.

    1995-01-01

    The primary aim of radiological protection is to provide an appropriate standard of protection for mankind, both as individuals and collectively, without unduly limiting the beneficial practices giving rise to radiation exposure. Guidance on the fundamental principles for radiation protection is provided on a global scale by the International Commission on Radiological Protection (ICRP). Member states of the European Union, such as the UK, are bound by the Euratom Treaty that requires the Commission of the European Communities (CEC) to develop uniform standards for radiological protection. These standards are based on recommendations from ICRP and are laid down in Euratom Directives relating to the safety of workers and the public, and of patients undergoing medical exposures. Member states are required to introduce national legislation to comply with Directives. In addition to ICRP and CEC, other international bodies are involved in developing practical standards and guidelines for radiological protection. For example, the International Atomic Energy Agency (IAEA) provides guidelines relating to the transport of radioactive material, and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) provides information on the biological effects of radiation. In the UK, the National Radiological Protection Board (NRPB) was established in 1970 as a statutory advisory body. It has no regulatory functions. NRPB advises Government on the acceptability and applicability of international recommendations. Principles are then applied in the UK by Acts of Parliament and subsidiary instruments such as regulations, licences, authorizations and approvals. Various government departments are involved in policing the control of radiation according to their particular role, for example the Department of the Environment in relation to pollution, and the Department of Employment for the health and safety of workers. (author)

  17. Enforcement of radiation safety standards and experience in the regulatory control of exposures

    International Nuclear Information System (INIS)

    Krishnamurthi, T.N.

    1997-01-01

    Regulatory provisions for radiation protection and their enforcement in India are discussed in this paper. The rules and regulations framed for radiation safety cover all the nuclear fuel cycle activities as well as the application of radiation sources in industrial, medical and research institutions. The enforcement aspects and experience in the control of exposures are presented. (author)

  18. Ordinary mode auroral kilometric radiation fine structure observed by DE 1

    International Nuclear Information System (INIS)

    Benson, R.F.; Mellott, M.M.; Huff, R.L.; Gurnett, D.A.

    1988-01-01

    The fine structure observed with intense right-hand extraordinary (R-X) mode auroral kilometric radiation (AKR) has received major theoretical attention. Data from the Dynamics Explorer 1 plasma wave instrument indicate that left-hand ordinary (L-O) mode AKR posses similar fine structure. Several theories have been proposed to explain the fine structure of the R-X mode AKR. In order to account for the L-O mode fine structure, these theories will have to be modified to produce the L-O mode directly or will have to rely on mode conversion processes from the R-X to the L-O mode

  19. Situation in the radiation protection field in Costa Rica

    International Nuclear Information System (INIS)

    Pacheco Jimenez, R.E.

    2001-01-01

    The report describes the radiation protection infrastructure in Costa Rica and makes reference to the existing legal framework. The national inventory of significant radiation sources and structure of the Ministry of Health as the national regulatory authority for radiation safety is illustrated; information is also provided on the radiation monitoring equipment available, on programme activities related to the control of radiation sources by authorization and inspection, and on technical support services. (author)

  20. A-State-of-the-Art Report on Application of Radiation Technology to Environmental Pollution Control

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Kwang; Lee, Myun Joo

    2004-06-15

    Radiation technology has been rapidly developed for decades and its applicability also enlarged to many fields such as environmental protection, medical care, manufacturing industry, agriculture, and bio technology. In this report, we focused on the present situation of the development of radiation facilities and state-of-the-art on application of radiation to environmental pollution control including purification of flue gas, waste water treatment, and recycling of biological waste. We especially discussed the radiation technology for environmental pollution control and described the capability of its application to the industrial plants in Korea.

  1. Principles for the exemption of radiation sources and practices from regulatory control

    International Nuclear Information System (INIS)

    1988-01-01

    Radiation sources, including equipment and installations, which emit ionizing radiations, are potentially harmful to health and their use should therefore be regulated. Some types of radiation source, however, do not need to be subject to regulatory control, because they present such a low hazard that it would be a needless waste of time and effort to exercise control by a regulatory process and they can therefore be exempted from it. An Advisory Group Meeting was convened in Vienna in March 1988 sponsored jointly by the IAEA and NEA. This Safety Guide is the result of that meeting and represents a first international consensus on the subject of exemption principles. This document is issued as an IAEA Safety Guide since it recommends a procedure which might be followed in implementing the Basic Safety Standards (BSS) for Radiation Protection. Its purpose is to recommend a policy on exemptions from the BSS system of notification, registration and licensing. 15 refs

  2. Effect of low-intensity electromagnetic radiation on structurization properties of bacterial lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Grigory E. Brill

    2014-09-01

    Full Text Available Purpose — to investigate the effects of low-intensity electromagnetic radiation on the process of dehydration selforganization of bacterial lipopolysaccharide (LPS. Material and Methods — The method of wedge dehydration has been used to study the structure formation of bacterial LPS. Image-phases analysis included their qualitative characteristics, as well as the calculation of quantitative indicators, followed by statistical analysis. Results — Low-intensity ultra high frequency (UHF radiation (1 GHz, 0.1 μW/cm2, 10 min has led to the changes in the suspension system of the LPS-saline reflected in the kinetics of structure formation. Conclusion — 1 GHz corresponds to the natural frequency of oscillation of water clusters and, presumably, the effect of UHF on structure of LPS mediates through the changes in water-salt environment. Under these conditions, properties of water molecules of hydration and possibly the properties of hydrophobic and hydrophilic regions in the molecule of LPS, which can affect the ability of toxin molecules to form aggregates change. Therefore the LPS structure modification may result in the change of its toxic properties.

  3. Regulations under the Radiation Protection and Control Act, 1982, No. 221 of 1984

    International Nuclear Information System (INIS)

    1984-01-01

    These Regulations made under the Radiation Protection and Control Act of 1982, amend several numerical quotations contained in the Radiation Safety (Transport) Regulations, No. 27, 1984, also made under the above mentioned Act. (NEA) [fr

  4. Dosimetric systems developed in Brazil for the radiation processes quality control

    International Nuclear Information System (INIS)

    Galante, Ana Maria Sisti; Campos, Leticia Lucente

    2011-01-01

    In order to apply new technologies to the industrial processing of materials aiming economy, efficiency, speed and high quality, ionizing radiation has been used in medicine, archaeology, chemistry, food preservation and other areas. For this reason, the dosimetry area looks for improve current dosimeters and develop new materials for application on quality control of these processes. In Brazil, the research in the dosimetry area occurs with great speed providing many different dosimetric systems. The chemical dosimetry is the most used technique in routine dosimetry, which requires fast and accurate responses. This technique involves determination of absorbed dose by measuring chemical changes radiation induced in the materials. Different dosimetric systems were developed at IPEN for application on radiation process quality and all of them present excellent results; the low cost of these materials allows a more effective dose control, therefore, a larger area or volume can be monitored. (author).

  5. Promoting safety culture in radiation industry through radiation audit

    International Nuclear Information System (INIS)

    Noriah, M.A.

    2007-01-01

    This paper illustrates the Malaysian experience in implementing and promoting effective radiation safety program. Current management practice demands that an organization inculcate culture of safety in preventing radiation hazard. The aforementioned objectives of radiation protection can only be met when it is implemented and evaluated continuously. Commitment from the workforce to treat safety as a priority and the ability to turn a requirement into a practical language is also important to implement radiation safety policy efficiently. Maintaining and improving safety culture is a continuous process. There is a need to establish a program to measure, review and audit health and safety performance against predetermined standards. This program is known as radiation safety audit and is able to reveal where and when action is needed to make improvements to the systems of controls. A structured and proper radiation self-auditing system is seen as the sole requirement to meet the current and future needs in sustainability of radiation safety. As a result safety culture, which has been a vital element on safety in many industries can be improved and promote changes, leading to good safety performance and excellence. (author)

  6. Thermal radiative properties of a photonic crystal structure sandwiched by SiC gratings

    International Nuclear Information System (INIS)

    Wang, Weijie; Fu, Ceji; Tan, Wenchang

    2014-01-01

    Spectral and directional control of thermal emission holds substantial importance in applications where heat transfer is predominantly by thermal radiation. In this work, we investigate the spectral and directional properties of thermal emission from a novel structure, which is constituted with a photonic crystal (PC) sandwiched by SiC gratings. Numerical results based on the RCWA algorithm reveal that greatly enhanced emissivity can be achieved in a broad frequency band and in a wide range of angle of emission. This promising emission feature is found to be caused by excitation of surface phonon polaritons (SPhPs), PC mode, magnetic polaritons (MPs) and Fabry–Pérot resonance from high order diffracted waves, as well as the coupling between different resonant modes. We show that the broad enhanced emissivity band can be manipulated by adjusting the dimensional parameters of the structure properly. -- Highlights: ► We propose a novel structure made of a photonic crystal sandwiched by SiC gratings. ► High emissivity can be achieved in a broad spectral band and angle range. ► We explain the result by excitation of multiple excited modes and their coupling

  7. Analysis of CT radiation dose based on radiation-dose-structured reports

    International Nuclear Information System (INIS)

    Wang Weipeng; Zhang Yi; Zhang Menglong; Zhang Dapeng; Song Shaojuan

    2014-01-01

    Objective: To analyse the CT radiation dose statistically using the standardized radiation-dose-structured report (RDSR) of digital imaging and communications in medicine (DICOM). Methods: Using the self-designed software, 1230 RDSR files about CT examination were obtained searching on the picture archiving and communication system (PACS). The patient dose database was established by combination of the extracted relevant information with the scanned sites. The patients were divided into adult group (over 10 years) and child groups (0-1 year, 1-5 years, 5-10 years) according to the age. The average volume CT dose index (CTDI vol ) and dose length product (DLP) of all scans were recorded respectively, and then the effective dose (E) was estimated. The DLP value at 75% quantile was calculated and compared with the diagnostic reference level (DRL). Results: In adult group, CTDI vol and DLP values were moderately and positively correlated (r = 0.41), the highest E was observed in upper abdominal enhanced scan, and the DLP value at 75% quantile was 60% higher than DRL. In child group, their CTDI vol in group of 5-10 years was greater than that in groups of 0-1 and 1-5 years (t = 2.42, 2.04, P < 0.05); the DLP value was slightly and positively correlated with the age (r = 0.16), while E was moderately and negatively correlated with the age (r = -0.48). Conclusions: It is a simple and efficient method to use RDSR to obtain the radiation doses of patients. With the popularization of the new equipment and the application of regionalized medical platform, RDSR would become the main tool for the dosimetric level surveying and individual dose recording. (authors)

  8. The selection and use of control groups in epidemiologic studies of radiation and cancer

    International Nuclear Information System (INIS)

    Howe, G.R.; Friedenreich, C.M.; Howe, P.D.

    1990-09-01

    Current risk estimates for radiation-induced cancer are based on epidemiologic studies of humans exposed to high doses of radiation. A critical feature of such studies is the selection of an appropriate control group. This report presents a detailed examination of the principles underlying the selection and use of control groups in such epidemiologic studies. It is concluded that the cohort study is the preferred design, because of the rarity of exposure to high levels of radiation in the general population and because the cohort design is less susceptible to bias. This report also assesses potential bias in current risk estimates for radiation-induced cancer due to inappropriate choice and use of control groups. Detailed summaries are presented for those epidemiologic studies on which the BEIR IV risk estimates are based. It is concluded that confounding is by far the major potential concern. Bias is probably negligible in risk estimates for breast cancer. For lung cancer, risk estimates may be underestimated by about 30 percent for males and 10 percent for females due to confounding of smoking and radiation exposure. For leukemia and cancers of the thyroid and bone, the absence of established non-radiation risk factors with a high prevalence in the population under study suggests that there is unlikely to be any substantial confounding radiation risk estimates. Finally, lifetime excess mortality risks have been estimated for several of the cancers of interest following exposure to radiation based on Canadian age-, sex- and cause-specific mortality rates. It is concluded that errors in measurement exposure, uncertainty in extrapolating the results of high dose studies to low doses and low dose rates, and sampling variation in the epidemiologic studies contribute far more to uncertainty in current risk estimates than do any biases in the epidemiologic studies introduced by inappropriate selection and use of control groups. (161 refs., 19 tabs.)

  9. Radiation processes for the control of NOx/SO2 emissions

    International Nuclear Information System (INIS)

    Dickson, L.W.; Singh, A.

    1988-01-01

    This report provides a brief review of the use of radiation for the treatment of flue gases and identifies areas for additional research. Two different radiation-based processes have been developed for the removal of nitrogen oxides and sulphur dioxide from the flue gases of coal-fired boilers. In the technique developed by the Ebara Corporation and Japan Atomic Energy Research Institute, ammonia is injected prior to the irradiation step to enhance the process efficiency and to yield a solid ammonium sulphate - ammonium nitrate product that may be used as a fertilizer. The process developed by the Research-Cottrell Corporation uses electron-beam irradiation downstream of a lime spray dryer to remove nitrogen oxides and to enhance the sulphur dioxide removal efficiency. Both of these processes require large quantities of electron-beam power and are currently expected to be more expensive than other available sulphur dioxide emission control technologies. Present emission control regulations in North America do not require the high degree of nitrogen oxide removal provided by the radiation-based processes. Research into the radiolytic oxidation of nitrogen oxides and sulphur dioxide, the radiolytic oxidation of NO x /SO 2 on solid sorbents, and the radiolytic oxidation of NO x /SO 2 in electric fields may lead to the development of more economical radiation treatment processes for flue gases. 44 refs

  10. Understanding of radiation effect on sink in aluminum base structure materials

    International Nuclear Information System (INIS)

    Choi, Sang Il; Kim, Ji Hyun

    2014-01-01

    In case of aluminum, a slightly different approach is needed for the evaluation of radiation damage. Unlikely other structure materials such as zirconium alloy and iron based alloy, aluminum generate not only matrix defect but also much transmutation. Quantitative analysis of radiation damage of aluminum have been done in two research method. First research method is calculation of radiation damage quantity in the matrix. In this research, quantity of transmutation and matrix damage are evaluated by KMC simulation from ENDF database of IAEA. Most recently, radiation damage such as defect and transmutation are calculated in the MNSR reactor environment. The second research method is evaluation of sink morphology change by irradiation, which research method focus on accumulating behavior of radiation defects. Matrix defect and transmutation are clustering or dissolved by thermal diffusion and energy statue. These clustering defect such as dislocation loop, void and bubble directly affect mechanical properties. In this research area, it is hard to using deterministic method because it should describe envious and various reaction module in detail. However, in case of probabilistic method, it could be explained without detail reaction module. Most recently, there was KMC modeling about vacancy and helium cluster. From this cluster modeling, transmutation is quantitatively analyzed. After that cluster effect on swelling are explained. Unfortunately, silicon, which is another transmutation of aluminum, effect are neglected. Also primary cluster, which is generated by cascade, effect are neglected. For the fundamental understanding of radiation effect on aluminum alloy, it is needed that more various parameter such as alloy element and primary cluster effect should be researched. However, until now there was not general modeling which include alloy element and primary cluster effect on aluminum. However, there was not specified KMC platform for the quantitative analysis of

  11. Enforcement of radiation safety standards and experience in the regulatory control of exposures

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamurthi, T N [Health and Safety Div., Atomic Energy Regulatory Board, Mumbai (India)

    1997-11-01

    Regulatory provisions for radiation protection and their enforcement in India are discussed in this paper. The rules and regulations framed for radiation safety cover all the nuclear fuel cycle activities as well as the application of radiation sources in industrial, medical and research institutions. The enforcement aspects and experience in the control of exposures are presented. (author). 3 refs, 2 tabs.

  12. Metamict state radiation damage in crystalline materials

    International Nuclear Information System (INIS)

    Haaker, R.F.; Ewing, R.C.

    1979-01-01

    Metamict minerals provide an excellent basis for the evaluation of long-term radiation damage effects, particularly such changes in physical and chemical properties as microfracturing, hydrothermal alteration, and solubility. This paper summarizes pertinent literature on metamictization and proposes experiments that are critical to the elucidation of structural controls on radiation damage in crystalline phases

  13. Ubiquitin-dependent system controls radiation induced apoptosis

    International Nuclear Information System (INIS)

    Delic, J.; Magdelenat, H.; Glaisner, S.; Magdelenat, H.; Maciorowski, Z.

    1997-01-01

    The selective proteolytic pathway, dependent upon 'N-end rule' protein recognition/ubiquitination and on the subsequent proteasome dependent processing of ubiquitin conjugates, operates in apoptosis induced by γ-irradiation. The proteasome inhibitor peptide aldehyde, MG132, efficiently induced apoptosis and was also able (at doses lower than those required for apoptosis induction) to potentiate apoptosis induced by DNA damage. Its specificity is suggested by the induction of the ubiquitin (UbB and UbC) and E1 (ubiquitin activating enzyme) genes and by an altered ubiquitination pattern. More selectively, a di-peptide competitor of the 'N-end rule' of ubiquitin dependent protein processing inhibited radiation induced apoptosis. This inhibition is also followed by an altered ubiquitination pattern and by activation of Poly (ADP-ribose) polymerase (PARP). These data strongly suggest that early apoptosis radiation induced events are controlled by ubiquitin-dependent proteolytic processing. (author)

  14. A comparison of the structure of radiation oncology in the United States and Japan

    International Nuclear Information System (INIS)

    Owen, Jean B.; Hanks, Gerald E.; Teshima, Teruki; Sato, Shinichiro; Tsunemoto, Hiroshi; Inoue, Toshihiko

    1996-01-01

    Purpose: The United States and Japan have very different backgrounds in their medical care systems. In the field of radiation oncology, national surveys on structure have been conducted for both countries and compared to illustrate any similarities and differences present from 1989-1990. Methods and Materials: The Patterns of Care Study Facility Survey conducted in 1989 in the United States and the National Survey of Structure in Japan in 1990 were compared to evaluate the equipment pattern, staffing pattern, compliance rate with the 'blue book' (3) guideline, and the geographic distribution of institutions. Results: In the United States, a total of 598,184 (49% of the total of newly diagnosed) patients were treated with radiation therapy. In Japan, 62,829 (approximately 15% of the total of newly diagnosed) patients were treated. The numbers of external megavoltage treatment machines were 2,397 in the United States and 494 in Japan. The numbers of full time equivalent (FTE) radiation oncologists were 2,335 in the United States and 366 in Japan. Only 15% of United States facilities and 11% of Japan facilities complied with the narrow blue book guideline for the patients per FTE radiation oncologist (200-250), while the most common ratio was 151-200 patients/FTE in the United States and 51-100 in Japan. In Japan, more than 60% of institutions were staffed by a part-time radiation oncologist (FTE < 1.0). Between geographic regions, there was variation in the percentage of cancer patients treated with radiation therapy for both the United States (42-56%) and Japan (6-25%). Conclusion: There is a major difference in the usage of radiation therapy for treating cancer between the United States and Japan with 49% of all new cancer patients treated in the United States and approximately 15% treated in Japan. Equipment structure in the United States is more complete than in Japan with important differences in treatment simulators, treatment planning computers, and support

  15. Radiation process control, study and acceptance of dosimetric methods

    International Nuclear Information System (INIS)

    Radak, B.B.

    1984-01-01

    The methods of primary dosimetric standardization and the calibration of dosimetric monitors suitable for radiation process control were outlined in the form of a logical pattern in which they are in current use on industrial scale in Yugoslavia. The reliability of the process control of industrial sterilization of medical supplies for the last four years was discussed. The preparatory works for the intermittent use of electron beams in cable industry were described. (author)

  16. Radiation synthesis and characterisation of the network structure of natural/synthetic double-network superabsorbent polymers

    International Nuclear Information System (INIS)

    Şen, Murat; Hayrabolulu, Hande

    2012-01-01

    In this study radiation synthesis and characterisation of the network structure of acrylic acid sodium salt/locust bean gum, (AAcNa/LBG) natural/synthetic double-network super absorbent polymers were investigated. Quartet systems composed of acrylic acid sodium salt/locust bean gum/N,N methylene bis acrylamide/water (AAcNa/LBG/MBAAm/water) were prepared at varying degree of neutralisations (DN) by controlling the DN value of AAc and irradiated with gamma rays at ambient temperature at a very low dose rate. The influences of the DN on the swelling and network properties were examined. It was observed that the DN strongly affected the gelation and super absorption properties of the gels. Molecular weight between crosslinks (M ¯ c ), effective crosslink density (ν e ) and mesh size (ξ) of SAPs were calculated from swelling and shear modules data obtained from compression and oscillatory frequency sweep tests. M ¯ c values obtained from the uniaxial deformation experiments were very close to those obtained from the oscillatory shear experiments excluding the completely neutralised gel system. It was concluded that the uniaxial compression technique could be used for the characterisation of the network structure of a hydrogel as along with the rheological analyses; however, a very precise control of the gel size was also needed. - Highlights: ► Radiation synthesis and characterisation of AAcNa/LBG super absorbent polymers described. ► Influences of the DN on the swelling and network properties were examined. ► Molecular weight between crosslinks and effective crosslink density of SAPs were calculated. ► Suitability of rheology technique for the characterisation of hydrogels were demonstrated.

  17. Radiation protection laws, competences and organizational structures in the Federal Republic of Germany

    International Nuclear Information System (INIS)

    Peinsipp, N.

    1990-01-01

    This paper points out the priorities and peculiarities of German radiation protection laws. With the coming into force of the unification agreement, the Atomic Energy Act, the Radiation Protection Ordinance, and the X-Ray Ordinance became valid in the five new Federal States and Berlin, with slight deviations and amendments. Radiation protection law is Federal law adapted to EC law, with several variations, such as the minimization rule in section 28, para 1, Radiation Protection Ordinance, compared to the ALARA principle, or lower partial body dose limits. The paper discusses licensing and protective regulations; the terms' officer responsible for radiation protection' and 'officer in charge of radiation protection'; radiation pass; physical radiation monitoring, and medical follow-up checks as well as governmental control functions and competences; executive functions of the Federal Government; import and export; Bundesamt fuer Strahlenschutz; transportation of radioactive materials; radioactive waste management. The annex comprises several tables to illustrate the aforesaid. (HSCH) [de

  18. Chromatin Structure and Radiation-Induced Intrachromosome Exchange

    Science.gov (United States)

    Mangala; Zhang, Ye; Hada, Megumi; Cucinotta, Francis A.; Wu, Honglu

    2011-01-01

    We have recently investigated the location of breaks involved in intrachromosomal type exchange events, using the multicolor banding in situ hybridization (mBAND) technique for human chromosome 3. In human epithelial cells exposed to both low- and high-LET radiations in vitro, intrachromosome exchanges were found to occur preferentially between a break in the 3p21 and one in the 3q11. Exchanges were also observed between a break in 3p21 and one in 3q26, but few exchanges were observed between breaks in 3q11 and 3q26, even though the two regions were on the same arm of the chromosome. To explore the relationships between intrachromosome exchanges and chromatin structure, we used probes that hybridize the three regions of 3p21, 3q11 and 3q26, and measured the distance between two of the three regions in interphase cells. We further analyzed fragile sites on the chromosome that have been identified in various types of cancers. Our results demonstrated that the distribution of breaks involved in radiation-induced intrachromosome aberrations depends upon both the location of fragile sites and the folding of chromatins

  19. Radiation heredity: unusual structural-phase states and metallic crystals properties

    International Nuclear Information System (INIS)

    Melikhov, V.D.; Skakov, M.K.

    1998-01-01

    Some experimental results allowing to judge about possibilities of unusual structural phase states formation during use irradiation and high temperature treatment of metallic crystals are considered. During study of pure (99.99 %) and especially pure (99.999 %) aluminium it was established, that after heating of preliminary irradiated samples in reactor, and non-irradiated ones up to temperatures above melting point (660 deg C), but not higher than 820 deg C, and cooling an microstructure and substructure of both irradiated and non-irradiated metals have been essentially distinguished with each other. If first of them had typically polycrystal construction, that second one was monocrystal with good developed initial substructure. Radiation effects have been preserved even in liquid metal if it was not overheated higher critical point, which is determined by phase transition from quasi-liquid state to true liquid one. During study of irradiation and postradiation treatment of structure and properties of intermetallides Fe 3 Al it was revealed, that in initially irradiated regulated alloys the radiation effect is preserving at heating of above 0.85 T melt (that essentially exceed order-disorder transition temperature) (550 deg C) in non-irradiated alloys of prolonged exposure and hardening. At that, irradiated-hardened alloy distinguishing from not hardened one by lattice parameter (on 0.1 %), by configuration of nearest surrounding of iron atoms in elementary cell, by regulating extent of different kind of atoms in lattice knocks. It was revealed, that at fluence (5·10 24 n·m 2 ) an appearance of new phases, distinguishing from matrix by component content. It was shown, that irradiation and post-radiation treatment are methods for creation unusual structural-phase states and attach to metals and alloys new properties

  20. Radiation protection service for a nucleonic control system of continuous casting plant after events of accident

    International Nuclear Information System (INIS)

    Chakrabarti, Santanu; Massand, O.P.

    1998-01-01

    Extensive use of nucleonic control systems like level controllers was observed during radiation protection surveys in industries such as refineries, steel plants etc., located in the eastern region of India. There were two accidents at continuous casting plant in 1995 which affected the nucleonic control system installed in 1992. The authorities contacted Bhabha Atomic Research Centre (BARC) for radiation protection surveys for the involved nucleonic gauges. The present paper describes the radiation protection services rendered by BARC during such accidents. (author)

  1. Structuring of poly ether ether ketone by ArF excimer laser radiation in different atmospheres

    International Nuclear Information System (INIS)

    Feng, Y.; Gottmann, J.; Kreutz, E.W.

    2003-01-01

    Structuring of poly ether ether ketone (PEEK) by 193 nm ArF excimer laser radiation has been investigated. Experiments were carried out in different atmospheres (air, vacuum, Ar, O 2 ) in order to study its influence on the quality of the structures and the formation of the debris. Repetition rate makes little effect on the ablation rate and roughness of the structure in presence of any kind of atmosphere, indicating for the structuring of PEEK by ArF laser radiation a large window of processing. The roughness at the bottom of the structures and the morphology of the side walls are strongly affected by the properties of the atmosphere. The smallest roughness is achieved at 0.6 J/cm 2 for all kinds of processing gases. Debris around the structures can be diminished by structuring in vacuum. Plasma expansion speed has been measured by using high speed photography

  2. Regulatory control of radiation sources and radioactive materials in the Czech Republic

    International Nuclear Information System (INIS)

    Drabova, D.; Prouza, Z.

    2001-01-01

    The paper describes legal and regulatory provisions for radiation protection and safe use of sources of ionizing radiation in the Czech Republic with special emphasis on aspects of bringing activities under regulatory control and releasing them from it. It covers the development of a new legal framework, the work of the regulatory body, an overview of sources in use and provisions to achieve effective regulatory control of facilities and releases of radioactive material into the environment. Also, it describes reported unusual events with a proposed scheme for their classification and evaluation. (author)

  3. Detection of electromagnetic radiation using micromechanical multiple quantum wells structures

    Science.gov (United States)

    Datskos, Panagiotis G [Knoxville, TN; Rajic, Slobodan [Knoxville, TN; Datskou, Irene [Knoxville, TN

    2007-07-17

    An apparatus and method for detecting electromagnetic radiation employs a deflectable micromechanical apparatus incorporating multiple quantum wells structures. When photons strike the quantum-well structure, physical stresses are created within the sensor, similar to a "bimetallic effect." The stresses cause the sensor to bend. The extent of deflection of the sensor can be measured through any of a variety of conventional means to provide a measurement of the photons striking the sensor. A large number of such sensors can be arranged in a two-dimensional array to provide imaging capability.

  4. Electron transport in nanometer GaAs structure under radiation exposure

    CERN Document Server

    Demarina, N V

    2002-01-01

    One investigates into effect of neutron and proton irradiation on electron transport in nanometer GaAs structures. Mathematical model takes account of radiation defects via introduction of additional mechanisms od scattering of carriers at point defects and disordered regions. To investigate experimentally into volt-ampere and volt-farad characteristics one used a structure based on a field-effect transistor with the Schottky gate and a built-in channel. Calculation results of electron mobility, drift rate of electrons, time of energy relaxation and electron pulse are compared with the experimental data

  5. Towards structural controllability of local-world networks

    International Nuclear Information System (INIS)

    Sun, Shiwen; Ma, Yilin; Wu, Yafang; Wang, Li; Xia, Chengyi

    2016-01-01

    Controlling complex networks is of vital importance in science and engineering. Meanwhile, local-world effect is an important ingredient which should be taken into consideration in the complete description of real-world complex systems. In this letter, structural controllability of a class of local-world networks is investigated. Through extensive numerical simulations, firstly, effects of local world size M and network size N on structural controllability are examined. For local-world networks with sparse topological configuration, compared to network size, local-world size can induce stronger influence on controllability, however, for dense networks, controllability is greatly affected by network size and local-world effect can be neglected. Secondly, relationships between controllability and topological properties are analyzed. Lastly, the robustness of local-world networks under targeted attacks regarding structural controllability is discussed. These results can help to deepen the understanding of structural complexity and connectivity patterns of complex systems. - Highlights: • Structural controllability of a class of local-world networks is investigated. • For sparse local-world networks, compared to network size, local-world size can bring stronger influence on controllability. • For dense networks, controllability is greatly affected by network size and the effect of local-world size can be neglected. • Structural controllability against targeted node attacks is discussed.

  6. Towards structural controllability of local-world networks

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Shiwen, E-mail: sunsw80@126.com [Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Computer Vision and System (Tianjin University of Technology), Ministry of Education, Tianjin 300384 (China); Ma, Yilin; Wu, Yafang; Wang, Li; Xia, Chengyi [Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Computer Vision and System (Tianjin University of Technology), Ministry of Education, Tianjin 300384 (China)

    2016-05-20

    Controlling complex networks is of vital importance in science and engineering. Meanwhile, local-world effect is an important ingredient which should be taken into consideration in the complete description of real-world complex systems. In this letter, structural controllability of a class of local-world networks is investigated. Through extensive numerical simulations, firstly, effects of local world size M and network size N on structural controllability are examined. For local-world networks with sparse topological configuration, compared to network size, local-world size can induce stronger influence on controllability, however, for dense networks, controllability is greatly affected by network size and local-world effect can be neglected. Secondly, relationships between controllability and topological properties are analyzed. Lastly, the robustness of local-world networks under targeted attacks regarding structural controllability is discussed. These results can help to deepen the understanding of structural complexity and connectivity patterns of complex systems. - Highlights: • Structural controllability of a class of local-world networks is investigated. • For sparse local-world networks, compared to network size, local-world size can bring stronger influence on controllability. • For dense networks, controllability is greatly affected by network size and the effect of local-world size can be neglected. • Structural controllability against targeted node attacks is discussed.

  7. Radioactive hospital wastes. Radiations under control

    International Nuclear Information System (INIS)

    Bondeelle, A.; Delmotte, H.; Gauron, C.

    2006-07-01

    A set of articles proposes an overview of legal and regulatory evolutions regarding radioactive hospital wastes. These legal measures and evolutions are notably present in the Public Health code, in the Labour code. An article outlines the role of the radiation protection expert in the process of elimination of contaminated wastes (four major steps for this elimination are indicated; peculiarities of the hospital are outlined, as well as control procedures and the importance of training and information). An article describes the specific activity of the Creteil incinerator which comprises a unit for the incineration of care activity wastes under a very constraining regulation

  8. Structural modifications of spinels under radiation

    International Nuclear Information System (INIS)

    Quentin, A.

    2010-12-01

    This work is devoted to the study of spinel structure materials under radiation. For that purpose, samples of polycrystalline ZnAl 2 O 4 and monocrystalline MgAl 2 O 4 were irradiated by different heavy ions with different energies. Samples of ZnAl 2 O 4 were studied par electron transmission microscopy, and by grazing incidence X-Ray diffraction and Rietveld analysis. Samples of MgAl 2 O 4 were studied by optical spectroscopy. Most of the results concern amorphization and crystalline structure modification of ZnAl 2 O 4 especially the inversion. We were able to determine a stopping power threshold for amorphization, between 11 keV/nm and 12 keV/nm, and also the amorphization process, which is a multiple impacts process. We studied the evolution of the amorphous phase by TEM and showed a nano-patterning phenomenon. Concerning the inversion, we determined that it did happen by a single impact process, and the saturation value did not reach the random cation distribution value. Inversion and amorphization have different, but close, stopping power threshold. However, amorphization seems to be conditioned by a pre-damage of the material which consists in inversion. (author)

  9. Engineering design of a radiative divertor for DIII-D

    International Nuclear Information System (INIS)

    Smith, J.P.; Baxi, C.B.; Bozek, A.S.

    1995-10-01

    A new divertor configuration is being developed for the DIII-D tokamak. This divertor will operate in the radiative mode. Experiments and modeling form the basis for the new design. The Radiative Divertor reduces the heat flux on the divertor plates by dispersing the power with radiation in the divertor region. In addition, the Radiative Divertor structure will allow density control in plasma shapes required for advanced tokamak operation. The divertor structure allows for operation in either double-null or single-null plasma configurations. Four independently controlled divertor cryopumps will enable pumping at either the inboard (upper and lower) or the outboard (upper and lower) divertor plates. An upgrade to the DIII-D cryogenic system is part of this project. The increased capabilities of the cryogenic system will allow delivery of liquid helium and nitrogen to the three new cryopumps. The Radiative Divertor design is very flexible, and will allow physics studies of the effects of slot width and length. Radiative Divertor diagnostics are being designed in parallel to provide comprehensive measurements for diagnosing the divertor. The Radiative divertor installation is scheduled for late 1996. Engineering experience gained in the DIII-D Advanced Divertor program form a foundation for the design work on the Radiative Divertor

  10. Relation of structure to function for the US reference standard endotoxin after exposure to 60Co radiation

    International Nuclear Information System (INIS)

    Csako, G.; Suba, E.A.; Ahlgren, A.; Tsai, C.M.; Elin, R.J.

    1986-01-01

    The structure and function of the highly purified US reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a 60 Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins

  11. 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

  12. Asymptotic Structure of the Seismic Radiation from an Explosive Column

    Directory of Open Access Journals (Sweden)

    Marco Rosales-Vera

    2018-01-01

    Full Text Available We study the structure of the seismic radiation in the far field produced by an explosive column. Using an asymptotic solution for the far field of vibration (Heelan’s solution, we find analytical expressions to the peak particle velocity (PPV diagrams. These results are extended to the case of a charge with finite velocity of detonation.

  13. A Morphing Radiator for High-Turndown Thermal Control of Crewed Space Exploration Vehicles

    Science.gov (United States)

    Cognata, Thomas J.; Hardtl, Darren; Sheth, Rubik; Dinsmore, Craig

    2015-01-01

    Spacecraft designed for missions beyond low earth orbit (LEO) face a difficult thermal control challenge, particularly in the case of crewed vehicles where the thermal control system (TCS) must maintain a relatively constant internal environment temperature despite a vastly varying external thermal environment and despite heat rejection needs that are contrary to the potential of the environment. A thermal control system is in other words required to reject a higher heat load to warm environments and a lower heat load to cold environments, necessitating a quite high turndown ratio. A modern thermal control system is capable of a turndown ratio of on the order of 12:1, but for crew safety and environment compatibility these are massive multi-loop fluid systems. This paper discusses the analysis of a unique radiator design which employs the behavior of shape memory alloys (SMA) to vary the turndown of, and thus enable, a single-loop vehicle thermal control system for space exploration vehicles. This design, a morphing radiator, varies its shape in response to facesheet temperature to control view of space and primary surface emissivity. Because temperature dependence is inherent to SMA behavior, the design requires no accommodation for control, instrumentation, nor power supply in order to operate. Thermal and radiation modeling of the morphing radiator predict a turndown ranging from 11.9:1 to 35:1 independent of TCS configuration. Stress and deformation analyses predict the desired morphing behavior of the concept. A system level mass analysis shows that by enabling a single loop architecture this design could reduce the TCS mass by between 139 kg and 225 kg. The concept is demonstrated in proof-of-concept benchtop tests.

  14. Design of wideband solar ultraviolet radiation intensity monitoring and control system

    Science.gov (United States)

    Ye, Linmao; Wu, Zhigang; Li, Yusheng; Yu, Guohe; Jin, Qi

    2009-08-01

    According to the principle of SCM (Single Chip Microcomputer) and computer communication technique, the system is composed of chips such as ATML89C51, ADL0809, integrated circuit and sensors for UV radiation, which is designed for monitoring and controlling the UV index. This system can automatically collect the UV index data, analyze and check the history database, research the law of UV radiation in the region.

  15. Internat. conference about the radiation behaviour of metallic canning and structure materials for fast breeders in Ajaccio (Korsika)

    International Nuclear Information System (INIS)

    Anderko, K.; Ehrlich, K.

    1979-01-01

    The program includes 48 plenary reports as well as 22 contributions in the form of a poster view and has the following structure: - swelling of ferritic steel - structural instability under radiation - theory of swelling - experiments about the swelling of austenitic steels - mechanical properties after radiation - fuel element behaviour and material optimization - radiation creeping. Additional to the items respecting the conference titel some material problems of the fusion reactor were discussed. (orig./RW) [de

  16. New methods of highly efficient controlled generation of radiation by liquid crystal nanostructures in a wide spectral range

    International Nuclear Information System (INIS)

    Bagayev, S N; Klementyev, V M; Nyushkov, B N; Pivtsov, V S; Trashkeev, S I

    2012-01-01

    We report the recent results of research focused on a new kind of soft matter-the liquid-crystal nanocomposites with controllable mechanical and nonlinear optical properties. These are promising media for implementation of ultra-compact photonic devices and efficient sources of coherent radiation in a wide spectral range. We overview the technology of preparation of nematic-liquid-crystal media saturated with disclination defects. The defects were formed in different ways: by embedding nanoparticles and molecular objects, by exposure to alpha-particle flux. The defect locations were controlled by applying an electric field. We also present and discuss the recently discovered features of nematic-liquid-crystal media: a thermal orientation effect leading to the fifth-order optical nonlinearity, enormous second-order susceptibility revealed by measurements, and structural changes upon exposure to laser radiation. We report on efficient generation of harmonics, sum and difference optical frequencies in nematic-liquid-crystal media. In addition, transformation of laser radiation spectra to spectral supercontinua, and filamentation of laser beams were also observed in nematic-liquid-crystal media. We conclude that most nonlinear optical effects result from changes of the orientational order in the examined nematic liquid crystals. These changes lead to the symmetry breaking and disclination appearances.

  17. Indirect control and power in mutual control structures

    NARCIS (Netherlands)

    Karos, D.; Peters, H.J.M.

    2013-01-01

    In a mutual control structure agents exercise control over each other. Typical examples occur in the area of corporate governance: firms and investment companies exercise mutual control, in particular by owning each others’ stocks. In this paper we formulate a general model for such situations.

  18. Regulatory Control of Radiation Sources. Safety Guide (Arabic Edition)

    International Nuclear Information System (INIS)

    2012-01-01

    This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

  19. Control of dew and frost formation on leaf by radiative cooling

    International Nuclear Information System (INIS)

    Matsui, T.; Eguchi, H.; Mori, K.

    1981-01-01

    A radiative cooling system was developed to control dew and frost formations and to examine the effect of the radiative cooling on the leaf temperature. The growth chamber was provided with a box which was constructed by using heat insulating materials to minimize the disturbances and to regulate the air current. A cooling coil (cooling surface of 300 cm was equipped at the bottom of the box and manipulated by a refrigerator of 1, 430 kcal hour -1 , and a concave mirror was attached to the ceiling of the box to facilitate the reflection of the radiation from the leaf to the cooling coil. The moisture in air was supplied by flowing the controlled air (0.2 m min -1 ) into the box. The distribution of dew point temperatures was almost uniform horizontally even under vertically slight conversion (downward velocity of 1.3 cm sec -1 ) of the air. The leaf temperature became about 1.0°C lower than the ambient air temperature under the radiative cooling. The dew and the frost were clearly observed on the leaf after the time when the leaf temperature had become lower than the dew point temperature. The dew increased in size in course of time, and the frost varied in shape and in size with the temperatures. Thus, artificial formations of the dew and the frost were made possible by the radiative cooling system developed in this experiment

  20. Radiative transitions in InGaN quantum-well structures

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Noad Asaf [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    InGaN based light emitting devices demonstrate excellent luminescence properties and have great potential in lighting applications. Though these devices are already being produced on an industrial scale, the nature of their radiative transition is still not well understood. In particular, the role of the huge (>1MV/cm), built-in electric field in these transitions is still under debate. The luminescence characteristics of InGaN quantum well structures were investigated as a function of excitation power, temperature, and biaxial strain, with an intent of discerning the effects of the electric field and inhomogeneous indium distribution in the QW on the radiative transition. It was found that the luminescence energy did not scale only with the indium concentration but that the QW thickness must also be taken into account. The thickness affects the transition energy due to quantum confinement and carrier separation across a potential drop in the QW. The luminescence peak width was shown to increase with increased indium fraction, due to increased indium inhomogeneity. The carrier lifetime increased exponentially with QW thickness and luminescence wavelength, due to increased carrier separation. Measuring the luminescence energy and carrier lifetime as a function of excitation density showed that the electric field can be screened by strong excitation and, as a consequence, the carrier separation reduced. The temperature dependence of the luminescence showed evidence for bandtails in the density of states, a phenomenon that has been previously related to transition in indium-rich nano-clusters, yet could be accounted for by fluctuations in other parameters that affect the transition energy. Room temperature luminescence efficiency was shown to weakly decrease with increased QW thickness. The application of biaxial strain resulted in either a redshift or blueshift of the luminescence, depending on the sample. The direction and magnitude of the shift in luminescence

  1. Model reduction in integrated controls-structures design

    Science.gov (United States)

    Maghami, Peiman G.

    1993-01-01

    It is the objective of this paper to present a model reduction technique developed for the integrated controls-structures design of flexible structures. Integrated controls-structures design problems are typically posed as nonlinear mathematical programming problems, where the design variables consist of both structural and control parameters. In the solution process, both structural and control design variables are constantly changing; therefore, the dynamic characteristics of the structure are also changing. This presents a problem in obtaining a reduced-order model for active control design and analysis which will be valid for all design points within the design space. In other words, the frequency and number of the significant modes of the structure (modes that should be included) may vary considerably throughout the design process. This is also true as the locations and/or masses of the sensors and actuators change. Moreover, since the number of design evaluations in the integrated design process could easily run into thousands, any feasible order-reduction method should not require model reduction analysis at every design iteration. In this paper a novel and efficient technique for model reduction in the integrated controls-structures design process, which addresses these issues, is presented.

  2. Influence of beryllium ceramics nano-structuring by iron atoms on increase of their stability to ionizing radiations effect

    International Nuclear Information System (INIS)

    Polyakov, A.I.; Bitenbaev, M.I

    2007-01-01

    In the work a new results on beryllium ceramics nano-structuring effect by iron oxide atoms on radiation defects quantum yield value G in these materials and defects depth constants in ionizing radiation fields k are presented. Experimental data under dependence of G and k values from concentration of iron atoms in beryllium ceramic matrix are presented. It is shown, that structure modification of beryllium ceramics by feedings on the iron base leads to sharp decrease (almost in 30 times) of radiation defects quantum yield value, i.e. to increase of these ceramics stability enhancement to ionizing radiation effect

  3. Ultra-Low Power Consuming Direct Radiation Sensors Based on Floating Gate Structures

    Directory of Open Access Journals (Sweden)

    Evgeny Pikhay

    2017-07-01

    Full Text Available In this paper, we report on ultra-low power consuming single poly floating gate direct radiation sensors. The developed devices are intended for total ionizing dose (TID measurements and fabricated in a standard CMOS process flow. Sensor design and operation is discussed in detail. Original array sensors were suggested and fabricated that allowed high statistical significance of the radiation measurements and radiation imaging functions. Single sensors and array sensors were analyzed in combination with the specially developed test structures. This allowed insight into the physics of sensor operations and exclusion of the phenomena related to material degradation under irradiation in the interpretation of the measurement results. Response of the developed sensors to various sources of ionizing radiation (Gamma, X-ray, UV, energetic ions was investigated. The optimal design of sensor for implementation in dosimetry systems was suggested. The roadmap for future improvement of sensor performance is suggested.

  4. GLOBAL STRUCTURE OF THREE DISTINCT ACCRETION FLOWS AND OUTFLOWS AROUND BLACK HOLES FROM TWO-DIMENSIONAL RADIATION-MAGNETOHYDRODYNAMIC SIMULATIONS

    International Nuclear Information System (INIS)

    Ohsuga, Ken; Mineshige, Shin

    2011-01-01

    We present the detailed global structure of black hole accretion flows and outflows through newly performed two-dimensional radiation-magnetohydrodynamic simulations. By starting from a torus threaded with weak toroidal magnetic fields and by controlling the central density of the initial torus, ρ 0 , we can reproduce three distinct modes of accretion flow. In model A, which has the highest central density, an optically and geometrically thick supercritical accretion disk is created. The radiation force greatly exceeds the gravity above the disk surface, thereby driving a strong outflow (or jet). Because of mild beaming, the apparent (isotropic) photon luminosity is ∼22L E (where L E is the Eddington luminosity) in the face-on view. Even higher apparent luminosity is feasible if we increase the flow density. In model B, which has moderate density, radiative cooling of the accretion flow is so efficient that a standard-type, cold, and geometrically thin disk is formed at radii greater than ∼7 R S (where R S is the Schwarzschild radius), while the flow is radiatively inefficient otherwise. The magnetic-pressure-driven disk wind appears in this model. In model C, the density is too low for the flow to be radiatively efficient. The flow thus becomes radiatively inefficient accretion flow, which is geometrically thick and optically thin. The magnetic-pressure force, together with the gas-pressure force, drives outflows from the disk surface, and the flow releases its energy via jets rather than via radiation. Observational implications are briefly discussed.

  5. Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

    International Nuclear Information System (INIS)

    1997-11-01

    The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference

  6. Structure of a radiate pseudocolony associated with an intrauterine contraceptive device

    International Nuclear Information System (INIS)

    O'Brien, P.K.; Lea, P.J.; Roth-Moyo, L.A.

    1985-01-01

    Transmission electron microscopy of a radiate pseudocolony associated with an intrauterine contraceptive device (IUCD) showed central bundles of extracellular fibers averaging 35 nm in diameter, surrounded by layered mantles of electron-dense, amorphous granular material. No bacterial, viral, or fungal structures were present. X-ray microanalysis revealed copper, sulfur, chloride, iron, and phosphorus; no calcium was found. It is postulated that these structures and histologically identical non-IUCD-associated granules from the female genital tract, as well as similar structures from other body locations, including those reported in colloid cysts of the third ventricle, are of lipofuscin origin

  7. Investigation of neutron radiation effects in structural materials for CTR use

    International Nuclear Information System (INIS)

    Wiffen, F.W.

    1975-01-01

    Neutron irradiation of structural materials in the high-flux region of a Controlled Thermonuclear Reactor (CTR), especially in the first wall of the reactor, will result in swelling due to cavity formation and loss of ductility through both lattice hardening and the effect of transmutation-produced helium on the fracture mode. The intensity and relative importance of the effects will be a strong function of the material and reactor operating conditions. A consideration of the effects of the 14 MeV D-T fusion neutrons, based on calculated damage response, on the sparse available data from high-energy neutron irradiation, and on an intuitive understanding of past radiation effects experimentation, suggests that although the 14 MeV neutrons will produce damage at a higher rate than lower-energy neutrons, there is no basis for anticipating different forms of damage. Irradiation experiments designed to evaluate materials for CTR service must be conducted in a number of facilities. Used in a well-coordinated evaluation program, the combined results from all available irradiation facilities will lead to an understanding of the radiation effects that will occur in CTRs. The experimental program will involve three distinct phases: (a) correlation experiments, (b) screening studies, and (c) qualification and design data generation. Each of these phases will evaluate a number of physical and mechanical properties. The end result of this program will be the qualification of a few materials for CTR use

  8. Drug release control in delivery system for biodegradable polymer drugs by γ-radiation

    International Nuclear Information System (INIS)

    Yoshioka, Sumie; Azo, Yukio; Kojima, Shigeo

    1997-01-01

    Characterizations of the drug release from microsphere and hydrogel preparation made from biodegradable polymers were investigated aiming at development of a drug delivery system which allows an optimum drug delivery and the identification of the factors which control its delivery. Poly-lactic acid microspheres containing 10% of progesterone were produced from poly DL-lactic acid and exposed to γ-ray at 5-1000 kGy. And its glass transition temperature (Tg) was determined by differential scanning calorimetry. The temperature was gradually lowered with an increase in the dose of radiation. Tg of the microsphere exposed at 1000 kGy was lower by 10degC compared with the untreated one, showing that Tg control is possible without changing the size distribution of microsphere. Then, the amount of progesterone released from microsphere was determined. The release rate of the drug linearly increased with a square root of radiation time. These results indicate that the control of drug release rate is possible through controling the microsphere's Tg by γ-ray radiation. (M.N.)

  9. Time-resolved photoelectron spectroscopy using synchrotron radiation time structure

    International Nuclear Information System (INIS)

    Bergeard, N.; Silly, M.G.; Chauvet, C.; Guzzo, M.; Ricaud, J.P.; Izquierdo, M.; Sirotti, F.; Krizmancic, D.; Guzzo, M.; Stebel, L.; Pittana, P.; Sergo, R.; Cautero, G.; Dufour, G.; Rochet, F.

    2011-01-01

    Synchrotron radiation time structure is becoming a common tool for studying dynamic properties of materials. The main limitation is often the wide time domain the user would like to access with pump-probe experiments. In order to perform photoelectron spectroscopy experiments over time scales from milliseconds to picoseconds it is mandatory to measure the time at which each measured photoelectron was created. For this reason the usual CCD camera based two-dimensional detection of electron energy analyzers has been replaced by a new delay-line detector adapted to the time structure of the SOLEIL synchrotron radiation source. The new two-dimensional delay-line detector has a time resolution of 5 ns and was installed on a Scienta SES 2002 electron energy analyzer. The first application has been to characterize the time of flight of the photo emitted electrons as a function of their kinetic energy and the selected pass energy. By repeating the experiment as a function of the available pass energy and of the kinetic energy, a complete characterization of the analyzer behaviour in the time domain has been obtained. Even for kinetic energies as low as 10 eV at 2 eV pass energy, the time spread of the detected electrons is lower than 140 ns. These results and the time structure of the SOLEIL filling modes assure the possibility of performing pump-probe photoelectron spectroscopy experiments with the time resolution given by the SOLEIL pulse width, the best performance of the beamline and of the experimental station. (authors)

  10. Structural Emergency Control Paradigm

    DEFF Research Database (Denmark)

    Vu, Thanh Long; Chatzivasileiadis, Spyros; Chiang, Hsiao-Dong

    2017-01-01

    demand and hopefully stabilize the system. This traditional emergency control results in interrupted service with severe economic damage to customers. Also, such control is usually less effective due to the lack of coordination among protective devices. In this paper, we propose a novel structural...

  11. Investigating the interaction of x-ray free electron laser radiation with grating structure

    NARCIS (Netherlands)

    Gaudin, J.; Ozkan, C.; Chalupsky, J.; Bajt, S.; Burian, T.; Vysin, L.; Coppola, N.; Farahani, S. D.; Chapman, H. N.; Galasso, G.; Hajkova, V.; Harmand, M.; Juha, L.; Jurek, M.; Loch, R. A.; Möller, S.; Nagasono, M.; Stormer, M.; Sinn, H.; Saksl, K.; Sobierajski, R.; Schulz, J.; Sovak, P.; Toleikis, S.; Tiedtke, K.; Tschentscher, T.; Krzywinski, J.

    2012-01-01

    The interaction of free electron laser pulses with grating structure is investigated using 4.6 +/- 0.1 nm radiation at the FLASH facility in Hamburg. For fluences above 63.7 +/- 8.7 mJ/cm(2), the interaction triggers a damage process starting at the edge of the grating structure as evidenced by

  12. RADIATION PRESSURE-SUPPORTED ACCRETION DISKS: VERTICAL STRUCTURE, ENERGY ADVECTION, AND CONVECTIVE STABILITY

    International Nuclear Information System (INIS)

    Gu Weimin

    2012-01-01

    By taking into account the local energy balance per unit volume between the viscous heating and the advective cooling plus the radiative cooling, we investigate the vertical structure of radiation pressure-supported accretion disks in spherical coordinates. Our solutions show that the photosphere of the disk is close to the polar axis and therefore the disk seems to be extremely thick. However, the density profile implies that most of the accreted matter exists in a moderate range around the equatorial plane. We show that the well-known polytropic relation between the pressure and the density is unsuitable for describing the vertical structure of radiation pressure-supported disks. More importantly, we find that the energy advection is significant even for slightly sub-Eddington accretion disks. We argue that the non-negligible advection may help us understand why the standard thin disk model is likely to be inaccurate above ∼0.3 Eddington luminosity, which was found by some works on black hole spin measurement. Furthermore, the solutions satisfy the Solberg-Høiland conditions, which indicate the disk to be convectively stable. In addition, we discuss the possible link between our disk model and ultraluminous X-ray sources.

  13. REP activities of the conference of radiation control program directors

    International Nuclear Information System (INIS)

    Bevill, B.

    1995-01-01

    This talk provides an overview of the activities within the Conference of Radiation Control Program Directors associated with Radiological Emergency Preparedness. Included are summaries of interactions with FEMA, with US DOE, with US FDA, and with US DOT

  14. Spacecraft radiator systems

    Science.gov (United States)

    Anderson, Grant A. (Inventor)

    2012-01-01

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

  15. Structural controllability and controlling centrality of temporal networks.

    Science.gov (United States)

    Pan, Yujian; Li, Xiang

    2014-01-01

    Temporal networks are such networks where nodes and interactions may appear and disappear at various time scales. With the evidence of ubiquity of temporal networks in our economy, nature and society, it's urgent and significant to focus on its structural controllability as well as the corresponding characteristics, which nowadays is still an untouched topic. We develop graphic tools to study the structural controllability as well as its characteristics, identifying the intrinsic mechanism of the ability of individuals in controlling a dynamic and large-scale temporal network. Classifying temporal trees of a temporal network into different types, we give (both upper and lower) analytical bounds of the controlling centrality, which are verified by numerical simulations of both artificial and empirical temporal networks. We find that the positive relationship between aggregated degree and controlling centrality as well as the scale-free distribution of node's controlling centrality are virtually independent of the time scale and types of datasets, meaning the inherent robustness and heterogeneity of the controlling centrality of nodes within temporal networks.

  16. Quantitative analysis of composition, structure and features of hemoglobin under the influence of radiation in vivo

    International Nuclear Information System (INIS)

    Kurbanov, F.F.; Mamedov, T.G.; Abdullaev, Kh.D.; Akhmedov, N.A.; Manojlov, S.K.

    1995-01-01

    The literature data on the changes in composition, structure and properties of hemoglobin under the influence of ionizing radiation in vivo are reviewed. The algorithm of calculation of damaged hemoglobin molecule percentage is proposed. Four main realizations of radiation-chemical damage are considered. By the algorithm the estimation of the damaged molecules percentage resulted from the exposure to 10 Gy is given. Hemoglobin radiation damage is considered as one of the most important mechanisms triggering radiation sickness. 11 refs

  17. Method and apparatus for surface characterization and process control utilizing radiation from desorbed particles

    International Nuclear Information System (INIS)

    Feldman, L.C.; Kraus, J.S.; Tolk, N.H.; Traum, M.M.; Tully, J.C.

    1983-01-01

    Emission of characteristic electromagnetic radiation in the infrared, visible, or UV from excited particles, typically ions, molecules, or neutral atoms, desorbed from solid surfaces by an incident beam of low-momentum probe radiation has been observed. Disclosed is a method for characterizing solid surfaces based on the observed effect, with low-momentum probe radiation consisting of electrons or photons. Further disclosed is a method for controlling manufacturing processes that is also based on the observed effect. The latter method can, for instance, be advantageously applied in integrated circuit-, integrated optics-, and magnetic bubble device manufacture. Specific examples of applications of the method are registering of masks, control of a direct-writing processing beam, end-point detection in etching, and control of a processing beam for laser- or electron-beam annealing or ion implantation

  18. Low-cost teleoperator-controlled vehicle for damage assessment and radiation dose measurement

    International Nuclear Information System (INIS)

    Tyree, W.H.

    1991-01-01

    A low-cost, disposable, radio-controlled, remote-reading, ionizing radiation and surveillance teleoperator re-entry vehicle has been built. The vehicle carries equipment, measures radiation levels, and evaluates building conditions. The basic vehicle, radio control with amplifiers, telemetry, elevator, and video camera with monitor cost less than $2500. Velcro-mounted alpha, beta-gamma, and neutron sensing equipment is used in the present system. Many types of health physics radiation measuring equipment may be substituted on the vehicle. The system includes a black-and-white video camera to observe the environment surrounding the vehicle. The camera is mounted on a vertical elevator extendible to 11 feet above the floor. The present vehicle uses a video camera with an umbilical cord between the vehicle and the operators. Preferred operation would eliminate the umbilical. Video monitoring equipment is part of the operator control system. Power for the vehicle equipment is carried on board and supplied by sealed lead-acid batteries. Radios are powered by 9-V alkaline batteries. The radio control receiver, servo drivers, high-power amplifier and 49-MHz FM transceivers were irradiated at moderate rates with neutron and gamma doses to 3000 Rem and 300 Rem, respectively, to ensure system operation

  19. Pinning Control Strategy of Multicommunity Structure Networks

    Directory of Open Access Journals (Sweden)

    Chao Ding

    2017-01-01

    Full Text Available In order to investigate the effects of community structure on synchronization, a pinning control strategy is researched in a class of complex networks with community structure in this paper. A feedback control law is designed based on the network community structure information. The stability condition is given and proved by using Lyapunov stability theory. Our research shows that as to community structure networks, there being a threshold hT≈5, when coupling strength bellows this threshold, the stronger coupling strength corresponds to higher synchronizability; vice versa, the stronger coupling strength brings lower synchronizability. In addition the synchronizability of overlapping and nonoverlapping community structure networks was simulated and analyzed; while the nodes were controlled randomly and intensively, the results show that intensive control strategy is better than the random one. The network will reach synchronization easily when the node with largest betweenness was controlled. Furthermore, four difference networks’ synchronizability, such as Barabási-Albert network, Watts-Strogatz network, Erdös-Rényi network, and community structure network, are simulated; the research shows that the community structure network is more easily synchronized under the same control strength.

  20. Surface and Bulk Nanostructuring of Polymers Using Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Güven, O.; Barsbay, M.; Ateş,; Akbulut, M. [Hacettepe University, Department of Chemistry, Ankara (Turkey)

    2009-07-01

    Ionizing radiation has long been known tobe a powerful tool in modifying and controlled the properties, forms and eventually end-uses of polymeric materials for a variety of applications. Industrial applications are full of successful examples of macro scale, bulk property modifications by radiation. Extremely short wavelength of ionizing radiation however, makes it an important and useful tool in creating very small size structures in polymers.

  1. Surface and Bulk Nanostructuring of Polymers Using Ionizing Radiation

    International Nuclear Information System (INIS)

    Güven, O.; Barsbay, M.; Ateş; Akbulut, M.

    2009-01-01

    Ionizing radiation has long been known tobe a powerful tool in modifying and controlled the properties, forms and eventually end-uses of polymeric materials for a variety of applications. Industrial applications are full of successful examples of macro scale, bulk property modifications by radiation. Extremely short wavelength of ionizing radiation however, makes it an important and useful tool in creating very small size structures in polymers

  2. Comparison of radiation and quenching rate effects on the structure of a sodium borosilicate glass

    International Nuclear Information System (INIS)

    Peuget, Sylvain; Maugeri, Emilio-Andrea; Mendoza, Clement; Fares, Toby; Bouty, Olivier; Jegou, Christophe; Charpentier, Thibault; Moskura, Melanie

    2013-01-01

    The effects of quenching rate and irradiation on the structure of a sodium borosilicate glass were compared using 29 Si, 11 B, and 23 Na nuclear magnetic resonance and Raman spectroscopy. Quenching rate ranging from 0.1 to 3 * 10 4 K min -1 was studied. Various irradiation conditions were performed, i.e. gold-ion irradiation in a multi-energy mode (from 1 to 6.75 MeV), and Kr and Xe ion irradiations with energy of 74 and 92 MeV, respectively. In pile irradiation with thermal neutron flux was performed as well, to study the effect of alpha radiation from the nuclear reaction 10 B(n,α) 7 Li. Both irradiation and high quenching rate induce similar local order modification of the glass structure, mainly a decrease of the mean boron coordination and an increase of Q 3 units. Nevertheless, the variations observed under irradiation are more pronounced than the ones induced by the quenching rate. Moreover, some important modifications of the glass medium range order, i.e. the emergence of the D2 band associated to three members silica rings and a modification of the Si-O-Si angle distribution were only noticed after irradiation. These results suggest that the irradiated structure is certainly not exactly the one obtained by a rapidly quenched equilibrated melt, but rather a more disordered structure that was weakly relaxed during the very rapid quenching phase following the energy deposition step. Raman spectroscopy showed a similar irradiated structure whereas the glass evolutions were controlled by the electronic energy loss in the ion track formation regime for Kr-ion irradiation or by the nuclear energy loss for Au and OSIRIS irradiation. The similar irradiated structure despite different irradiation routes, suggests that the final structural state of this sodium borosilicate glass is mainly controlled by the glass reconstruction after the energy deposition step. (authors)

  3. Optimal resonant control of flexible structures

    DEFF Research Database (Denmark)

    Krenk, Steen; Høgsberg, Jan Becker

    2009-01-01

    When introducing a resonant controller for a particular vibration mode in a structure this mode splits into two. A design principle is developed for resonant control based oil equal damping of these two modes. First the design principle is developed for control of a system with a single degree...... of freedom, and then it is extended to multi-mode structures. A root locus analysis of the controlled single-mode structure identifies the equal modal damping property as a condition oil the linear and Cubic terms of the characteristic equation. Particular solutions for filtered displacement feedback...... and filtered acceleration feedback are developed by combining the root locus analysis with optimal properties of the displacement amplification frequency curve. The results are then extended to multi-mode structures by including a quasi-static representation of the background modes in the equations...

  4. Analysis of a radiative heat exchanger for systems for thermal control of space vehicles

    International Nuclear Information System (INIS)

    Vasil'ev, L.L.; Kanonchik, L.E.; Babenko, V.A.

    1995-01-01

    Starting from the solution of a two-dimensional heat conduction problem, a mathematical model of a heat pipe-based radiative heat exchanger is developed. Good agreement between the predicted and experimental results is obtained. The effect of operational and structural parameters on the characteristics of the radiative heat exchanger is analyzed

  5. Designing of new structure PID controller of boost converter for solar photovoltaic stability

    Science.gov (United States)

    Shabrina, Hanifati Nur; Setiawan, Eko Adhi; Sabirin, Chip Rinaldi

    2017-03-01

    Nowadays, the utilization of renewable energy as the source on distributed generation system is increasing. It aims to reduce reliance and power losses from utility grid and improve power stability in near loads. One example of renewable energy technology that have been highly proven on the market is solar photovoltaic (PV). This technology converts photon from sunlight into electricity. However, the fluctuation of solar radiation that often occurs become the main problem for this system. Due to this condition, the power conversion is needed to convert the change frequently in photovoltaic panel into a stable voltage to the system. Developing control of boost converter has important role to keep ability of system stabilization. A conventional PID (Proportional, Integral, Derivative) control is mostly used to achieve this goal. In this research, a design of new structure PID controller of boost converter is offered to better optimize system stability comparing to the conventional PID. Parameters obtained from this PID structure have been successfully yield a stable boost converter output at 200 V with 10% overshoot, 1.5 seconds of settling time, and 1.5% of steady-state error.

  6. Estimating the Infrared Radiation Wavelength Emitted by a Remote Control Device Using a Digital Camera

    Science.gov (United States)

    Catelli, Francisco; Giovannini, Odilon; Bolzan, Vicente Dall Agnol

    2011-01-01

    The interference fringes produced by a diffraction grating illuminated with radiation from a TV remote control and a red laser beam are, simultaneously, captured by a digital camera. Based on an image with two interference patterns, an estimate of the infrared radiation wavelength emitted by a TV remote control is made. (Contains 4 figures.)

  7. Influence of filling pattern structure on synchrotron radiation and beam spectrum at ANKA

    Energy Technology Data Exchange (ETDEWEB)

    Steinmann, Johannes; Brosi, Miriam; Bruendermann, Erik; Caselle, Michele; Blomley, Edmund; Hiller, Nicole; Kehrer, Benjamin; Mueller, Anke-Susanne; Schoenfeldt, Patrik; Schuh, Marcel; Schwarz, Markus; Siegel, Michael [Karlsruher Institut fuer Technologie, Karlsruhe (Germany)

    2016-07-01

    We present the effects of the filling pattern structure in multi-bunch mode on the beam spectrum. This effects can be seen by all detectors whose resolution is better than the RF frequency, ranging from stripline and Schottky measurements to high resolution synchrotron radiation measurements. Our heterodyne measurements of the emitted coherent synchrotron radiation at 270 GHz reveal the discrete frequency harmonics around the 100'000 revolution harmonic of ANKA, the synchrotron radiation facility in Karlsruhe, Germany. Significant effects of bunch spacing, gaps between bunch trains and variations in individual bunch currents on the emitted CSR spectrum are described by theory and supported by observations.

  8. Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference. Refs, figs, tabs.

  9. Regulatory System of Radiation Protection in Taiwan

    International Nuclear Information System (INIS)

    Tang, F. T.; Huang, C. C.

    2004-01-01

    After the radioactive contaminated buildings incident occurred in Taiwan in 1993, the competent authority for radiation protection the Atomic Energy Council (AEC) started to review the structured problem of radiation protection regulatory system. Through several years' investigation and study, the AEC has improved two important tools in radiation protection regulatory system, i.e., control regulations and actual practice, and made them more rigorous and efficient. This paper will make a brief introduction of the efforts that Taiwan has made in this respect. Taiwan's radiation protection control was based on the Atomic Energy Law promulgated in 1968, but the control idea and authorization scope were not sufficient to appropriately respond to the highly developed economy and democracy in Taiwan. After several years' legislative process, the Ionizing Radiation Protection Law (IRP Law) was promulgated and entered into force on February 1, 2003. This IRP Law specifically emphasizes categorized risk management of radiation sources, establishment of personnel licenses and training system, enhancement of public safety control, and implementation of quality assurance program for medical exposure. The Legislative Yuan (Congress) fully authorized the competent authority to establish various technological control regulations according to control necessity without prior review by the Legislative Yuan in advance. As to the penalties of the violations of the IRP Law, the AEC adopts high-rated administrative fines and applies the Criminal Law to those who seriously contaminate the environment. In actual practice, the AEC has constructed a Radiation Protection Control Information System compatible with the IRP Law that fully combines the functions of computers and Internet. The information of facility operators who own radiation sources, radiation protection specialists, and operating personnel are entered into this system, starting from the submission of application of the

  10. Dynamics and stability of radiation-driven double ablation front structures

    International Nuclear Information System (INIS)

    Drean, V.; Olazabal-Loume, M.; Tikhonchuk, V. T.; Sanz, J.

    2010-01-01

    The dynamics of double ablation front (DAF) structures is studied for planar targets with moderate atomic number ablators. These structures are obtained in hydrodynamic simulations for various materials and laser intensities and are qualitatively characterized during the acceleration stage of the target. The importance of the radiative transport for the DAF dynamics is then demonstrated. Simulated hydrodynamic profiles are compared with a theoretical model, showing the consistency of the model and the relevant parameters for the dynamics description. The stability of DAF structures with respect to two-dimensional perturbations is studied using two different approaches: one considers the assumptions of the theoretical model and the other one a more complete physics. The numerical simulations performed with both approaches demonstrate good agreement of dispersion curves.

  11. Thermal analysis of an HVAC system with TRV controlled hydronic radiator

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Stoustrup, Jakob; Rasmussen, Henrik

    2010-01-01

    A model for an HVAC system is derived in this paper. The HVAC system consists of a room and a hydronic radiator with temperature regulating valve (TRV) which has a step motor to adjust the valve opening. The heating system and the room are simulated as a unit entity for thermal analysis and contr......A model for an HVAC system is derived in this paper. The HVAC system consists of a room and a hydronic radiator with temperature regulating valve (TRV) which has a step motor to adjust the valve opening. The heating system and the room are simulated as a unit entity for thermal analysis...... and controller design. A discrete-element model with interconnected small scaled elements is proposed for the radiator. This models the radiator more precisely than that of a lumped model in terms of transfer delay and radiator gain. This precise modeling gives us an intuition into a regular unwanted phenomenon...... which occurs in low demand situations. When flow is very low in radiator and the supply water temperature and the pressure drop across the valve is constant, oscillation in room temperature occurs. One reason could be the large gain of radiator in low demand conditions compared to the high demand...

  12. Ionizing radiation control of Tribolium castaneum in wheat flour type 000

    International Nuclear Information System (INIS)

    Ritacco, M.

    1988-01-01

    The insects, mainly those of the coleoptera order, produce serious changes on the grains and flours, producing in some regions up to 50 % loss. Taking in account the information available up to date, this experiment consists of putting under the effect of the ionizing radiation specimens of Tribolium castaneum feeded with bread flour type 000, with the purpose of controling their biological cycle. They received gamma radiation doses between 250 and 2000 Gy, using 60 Co source. The daily observation made over a population of 590 insects, indicates the efficiency of the procedure, non toxic, which provokes the sterility at 250 Gy and inmediate dead starting at 1750 Gy. On the other hand, it was verified that the DL 50 on the insects irradiated at the lower of eight different doses applied, reaches 15,3 days, against the 162,6 days of the reference Tribolium. Then it is concluded that it is technologically feasible the application of ionizing radiation to the bread wheat flour type 000 for controling this main plage. (Author) [es

  13. Parametric control of structural vibrations and sound radiation by fast time-space variation of distributed stiffness parameters

    International Nuclear Information System (INIS)

    Krylov, V.I.; Sorokin, S.V.

    1998-01-01

    The dynamics of a Euler-Bernoulli beam with a time-and-space dependent bending stiffness is studied. The , problem is considered in connection with the application of noise control using smart structures. It is shown that a control for the vibrations of the beam can be achieved by varying the bending stiffness. The technique of direct separation of fast and slow motion coupled with a Green's function method is used to analyze the dynamics of the beam with high-frequency modulation of the stiffness

  14. Contributions of each isotope in structural material on radiation damage in a hybrid reactor

    International Nuclear Information System (INIS)

    Günay, Mehtap

    2016-01-01

    In this study, the fluids were used in the liquid first-wall, blanket and shield zones of the designed hybrid reactor system. In this study, salt-heavy metal mixtures consisting of 93–85% Li_2_0Sn_8_0 + 5% SFG-PuO_2 and 2-10% UO_2, 93–85% Li_2_0Sn_8_0 + 5% SFG-PuO_2 and 2-10% NpO_2, and 93–85% Li_2_0Sn_8_0 + 5% SFG-PuO_2 and 2-10% UCO were used as fluids. In this study, the effect on the radiation damage of spent fuel-grade (SFG)-PuO_2, UO_2, NpO_2 and UCO contents was investigated in the structural material of a designed fusion–fission hybrid reactor system. In the designed hybrid reactor system were investigated the effect on the radiation damage of the selected fluid according to each isotopes of structural material in the structural material for 30 full power years (FPYs). Three-dimensional analyses were performed using the most recent MCNPX-2.7.0 Monte Carlo radiation transport code and the ENDF/B-VII.0 nuclear data library

  15. Operation control device under radiation exposure

    International Nuclear Information System (INIS)

    Kimura, Kiichi; Murakami, Toichi.

    1994-01-01

    The device of the present invention performs smooth progress of operation by remote control for a plurality of operations in periodical inspections in controlled areas of a nuclear power plant, thereby reducing the operator's exposure dose. Namely, the device monitors the progressing state of the operation by displaying the progress of operation on a CRT of a centralized control device present in a low dose area remote from an operation field through an ITV camera disposed in the vicinity of the operation field. Further, operation sequence and operation instruction procedures previously inputted in the device are indicated to the operation field through an operation instruction outputting device (field CRT) in accordance with the progress of the operation steps. On the other hand, the operation progress can be aided by inputting information from the operation field such as start or completion of the operation steps. Further, the device of the present invention can monitor the change of operation circumstances and exposure dose of operators based on the information from a radiation dose measuring device disposed in the operation circumstance and to individual operators. (I.S.)

  16. Controlling of degradation effects in radiation processing of polymers. Second RCM report

    International Nuclear Information System (INIS)

    2005-08-01

    The research and development works carried out by the participants of the CRP (Coordinated Research Project) dealt with natural polymers, synthetic polymers and new techniques for better understanding of radiation degradation of polymers. It includes progress in radiation degradation of polysaccharides from agricultural products (including sodium alginate, carrageenans, chitosan and gum acacia); use of radiation-degradation for doping of conductive polymers; controlling degradation processes in artificial joint implants, surface treatment of materials and food packaging; stabilizer additives for radiation environments; surface treatment of materials; and application of specialized analytical techniques (positron annihilation spectroscopy, ESR, RBS, ERDA, NMR/isotopic-labeling) to gain improved understanding of radiation degradation effects and mechanisms. Projects within the RCM group span the spectrum from fundamental studies through specific technological applications. Participants from Czech Republic, Spain and Turkey benefited from scientific collaboration with Bulgaria on PAS

  17. Radiation control act 1990 no. 13 (7/6/1990) New South Wales

    International Nuclear Information System (INIS)

    1990-01-01

    The object of the Act is to ensure the protection of persons and the environment against exposure to ionizing radiation and harmful non-ionizing radiation, taking into account social and economic factors and recognising that radiation is needed for therapeutic purposes. The Act regulates and controls the sale, use, keeping and disposal of radioactive substances and radiation apparatus, but does not apply to radioactive ores as defined by the Mines Inspection Act 1901. It provides for a licensing system for such substances and apparatus, the licensing authority being the Director-General of the Department of Health, under the overall authority of the Minister for Health. No person may sell or use the substances or apparatus without a licence granted by the Director-General. A licence is granted only following the recommendation of the Radiation Advisory Council set up under this Act [fr

  18. Fluid control structures in microfluidic devices

    Science.gov (United States)

    Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.

    2017-05-09

    Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

  19. Design of radiation shields in nuclear reactor core

    International Nuclear Information System (INIS)

    Mousavi Shirazi, A.; Daneshvar, Sh.; Aghanajafi, C.; Jahanfarnia, Gh.; Rahgoshay, M.

    2008-01-01

    This article consists of designing radiation shields in the core of nuclear reactors to control and restrain the harmful nuclear radiations in the nuclear reactor cores. The radiation shields protect the loss of energy. caused by nuclear radiation in a nuclear reactor core and consequently, they cause to increase the efficiency of the reactor and decrease the risk of being under harmful radiations for the staff. In order to design these shields, by making advantages of the O ppenheim Electrical Network m ethod, the structure of the shields are physically simulated and by obtaining a special algorithm, the amount of optimized energy caused by nuclear radiations, is calculated

  20. Uranium Mill Tailings Radiation Control Act of 1978

    International Nuclear Information System (INIS)

    Magee, J.

    1980-01-01

    The long-term environmental effects of the Uranium Mill Tailings Radiation Control Act of 1978 address the public health hazards of radioactive wastes and recognize the significance of this issue to public acceptance of nuclear energy. Title I of the Act deals with stabilizing and controlling mill tailings at inactive sites and classifies the sites by priority. It represents a major Federal commitment. Title II changes and strengthens Nuclear Regulatory Commission authority, but it will have little overall impact. It is not possible to assess the Act's effect because there is no way to know if current technology will be adequate for the length of time required. 76 references

  1. The ICRP 66 Internal Radiation Exposure Control and Dose Evaluation of The Institute of Nuclear Energy Research

    Energy Technology Data Exchange (ETDEWEB)

    Pang, H. F.; Hwang, W. S.; Chiu, J. H.

    2004-07-01

    The Atomic Energy Council (AEC) is the regulatory body of ionization radiation protection in Taiwan. To effectively control the safety in ionization radiation, AEC brought into force the Ionization Radiation Protection Act on 1 February, 2003 with clear statements of the penalty for violating the Law. The Article 5 of the Act provides: In order to limit the radiation exposure from radiation sources or practices, the Competent Authority shall refer to the latest standards of the International Commission on Radiological Protection to lay down the Safety Standards for Protection against Ionizing Radiation. Thus, AEC is going to draft new safety standards of ionization radiation protection of Taiwan according to ICRP Publication 60. The Institute of Nuclear Energy Research (INER), the governmental institute working on ionization radiation research in Taiwan, took the responsibility of assisting AEC in establishing guidelines on the control of internal radiation exposure and responding to the regulations in the new standards as soon as possible. So, according to the recommendations of ICRP Publications 60, 66,67,68,69,71,78,88, and IAEA Safety Standard Series No. RS-G- 1.1 and 1.2, INER undertook researches on the internal radiation exposure control and dose evaluations for INER's radiation workers as well as dose evaluations for the general public. The research accomplishments not only can be the reference of AEC when making new standards, but also can be followed by other radiation protection businesses. (Author) 23 refs.

  2. The ICRP 66 Internal Radiation Exposure Control and Dose Evaluation of The Institute of Nuclear Energy Research

    International Nuclear Information System (INIS)

    Pang, H. F.; Hwang, W. S.; Chiu, J. H.

    2004-01-01

    The Atomic Energy Council (AEC) is the regulatory body of ionization radiation protection in Taiwan. To effectively control the safety in ionization radiation, AEC brought into force the Ionization Radiation Protection Act on 1 February, 2003 with clear statements of the penalty for violating the Law. The Article 5 of the Act provides: In order to limit the radiation exposure from radiation sources or practices, the Competent Authority shall refer to the latest standards of the International Commission on Radiological Protection to lay down the Safety Standards for Protection against Ionizing Radiation. Thus, AEC is going to draft new safety standards of ionization radiation protection of Taiwan according to ICRP Publication 60. The Institute of Nuclear Energy Research (INER), the governmental institute working on ionization radiation research in Taiwan, took the responsibility of assisting AEC in establishing guidelines on the control of internal radiation exposure and responding to the regulations in the new standards as soon as possible. So, according to the recommendations of ICRP Publications 60, 66,67,68,69,71,78,88, and IAEA Safety Standard Series No. RS-G- 1.1 and 1.2, INER undertook researches on the internal radiation exposure control and dose evaluations for INER's radiation workers as well as dose evaluations for the general public. The research accomplishments not only can be the reference of AEC when making new standards, but also can be followed by other radiation protection businesses. (Author) 23 refs

  3. Synchrotron radiation : characteristics and application in structural studies and phase transformations of materials

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1984-01-01

    The main characteristics of the synchrotron radiation for studying atomic structure and phase transformations in materials are presented. Some specific applications in alloys, glass and solids are described. (E.G.) [pt

  4. Active control of radiated sound power from a baffled, rectangular panel

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    1996-01-01

    with an array of eleven microphones in front of the panel, is very close to minimising the actual radiated sound power. Practical experiments where such an array estimate has been minimised using the filtered X LMS algorithm have shown that substantial reductions of radiated sound power can be obtained over......Active control of radiated sound power from a rectangular baffled panel by minimisation of an accurate power estimate, using piezoceramic actuators, has been investigated. Computer simulations have shown that minimising a power estimate obtained by discretised integration of the far field intensity...... a broad frequency range using few piezoceramic actuators, provided that an accurate estimate of the sound power is available for minimisation....

  5. Event structure and cognitive control.

    Science.gov (United States)

    Reimer, Jason F; Radvansky, Gabriel A; Lorsbach, Thomas C; Armendarez, Joseph J

    2015-09-01

    Recently, a great deal of research has demonstrated that although everyday experience is continuous in nature, it is parsed into separate events. The aim of the present study was to examine whether event structure can influence the effectiveness of cognitive control. Across 5 experiments we varied the structure of events within the AX-CPT by shifting the spatial location of cues and probes on a computer screen. When location shifts were present, a pattern of AX-CPT performance consistent with enhanced cognitive control was found. To test whether the location shift effects were caused by the presence of event boundaries per se, other aspects of the AX-CPT were manipulated, such as the color of cues and probes and the inclusion of a distractor task during the cue-probe delay. Changes in cognitive control were not found under these conditions, suggesting that the location shift effects were specifically related to the formation of separate event models. Together, these results can be accounted for by the Event Horizon Model and a representation-based theory of cognitive control, and suggest that cognitive control can be influenced by the surrounding environmental structure. (c) 2015 APA, all rights reserved).

  6. Radiation spectroanalysis controlled and processed by a mini-computer

    Energy Technology Data Exchange (ETDEWEB)

    Minogashira, T; Shiokawa, Y; Suzuki, S [Tohoku Univ., Sendai (Japan). Research Inst. for Iron, Steel and Other Metals

    1975-06-01

    The principle of radiation spectroanalysis with minicomputer-controlled multi-channel analyzer system is explained. In the first part, the fundamental features of minicomputers are generally discussed with particular emphasis upon the combination with various I/O devices. In the second part, the MCA(multi-channel spectrum analyzer) system controlled by a minicomputer is explained from the aspects of both hardware and software. As for the hardware, the roles of ADC, console typewriter, paper tape I/O system, cathode ray tubes, X-Y recorder, and other auxiliary memories such as magnetic tapes and drums are discussed. As for the software, the function of system monitor is explained together with its block chart and individual software packages. The third part is devoted to the explanation of the mathematical methods for analyzing ..gamma..-radiation spectra. These include the smoothing of spectra with appropriate weighting coefficients, fitting with polynomials, and the detection of peaks by first derivative method. Some examples of spectroanalysis by these mathematical methods are presented. Recent works performed by other authors including many Japanese are also referred.

  7. Connecting inventory control and repair shop control : a differentiated control structure for repairable spare parts

    NARCIS (Netherlands)

    Driessen, M.A.; Rustenburg, W.D.; Houtum, van G.J.J.A.N.; Wiers, V.C.S.

    2014-01-01

    This paper presents a control structure for integrating decisions on spare parts inventory control and the control of repair shops for maintenance spare parts. A dierentiated control structure is proposed for the various repair shop types recognized in practice. Decisions functions are mapped and

  8. Process controls for radiation hardened aluminum gate bulk silicon CMOS

    International Nuclear Information System (INIS)

    Gregory, B.L.

    1975-01-01

    Optimized dry oxides have recently yielded notable improvements in CMOS radiation-hardness. By following the proper procedures and recipes, it is now possible to produce devices which will function satisfactorily after exposure to a total ionizing dose in excess of 10 6 RADS (Si). This paper is concerned with the controls required on processing parameters once the optimized process is defined. In this process, the pre-irradiation electrical parameters must be closely controlled to insure that devices will function after irradiation. In particular, the specifications on n- and p-channel threshold voltages require tight control of fixed oxide charge, surface-state density, oxide thickness, and substrate and p-well surface concentrations. In order to achieve the above level of radiation hardness, certain processing procedures and parameters must also be closely controlled. Higher levels of cleanliness are required in the hardened process than are commonly required for commercial CMOS since, for hardened dry oxides, no impurity gettering can be employed during or after oxidation. Without such gettering, an unclean oxide is unacceptable due to bias-temperature instability. Correct pre-oxidation cleaning, residual surface damage removal, proper oxidation and annealing temperatures and times, and the correct metal sintering cycle are all important in determining device hardness. In a reproducible, hardened process, each of these processing steps must be closely controlled. (U.S.)

  9. Polyacrolein with microspherical structure obtained by radiation-Initiation and base catalysis

    International Nuclear Information System (INIS)

    Usanmaz, A.; Dogan, R.D.

    1990-01-01

    Acrolein was polymerized by radiation and base catalyzed condensation. Radiation polymerization was carried in bulk form under vacuum and air atmosphere at several temperatures. The conversion reached close to 100 %, and polymers were free flowing white powders up to 5 % conversion at -15degC, up to 80 % at higher temperatures and up to 10 % in air atmosphere polymerization. Radiation polymerization from aqueous solutions of various pH and from acetone solutions gave white powder polymers with limiting conversions ranging from 10 to 18 % depending on the solution type or pH. The conversion at pH between 1, 5 to 8 gave minimum pH of 5 to 6. The base catalyzed polymerization at pH of 9 to 12 gave white powdered polymers changing to a yellowish colour with increase of pH. The limiting conversion was about 14 %. The nature of repeating units in the polymer chains was studied by IR and thermogravimetry. The polymers contained different repeating units randomly, and the aldehyde content was higher for radiation polymerization than base catalyzed polymerization. A scanning electron microscope investigation showed the powder polymers to have microspherical structures of various size depending on polymerization conditions. (author)

  10. Structural analysis of radiation-induced chromosome aberrations by atomic force microscope (AFM) before and after Giemsa staining

    International Nuclear Information System (INIS)

    Murakami, M.; Kanda, R.; Minamihisamatsu, M.; Hayata, I.

    2003-01-01

    Full text: We have studied structures of chromosome aberration induced by ionizing radiation by an atomic force microscope (AFM). The AFM could visualize the fine structure of chromosomes on Giemsa stained or unstained samples, although it was difficult to visualize unstained chromosomes by light microscope. The height data of chromosomes obtained by AFM provided useful information to describe detailed structure of chromatid gaps induced by heavy ion irradiation. A fibrous structure was observed on the unstained chromosome and these structures were considered to be the 30nm fibers on the chromosome. These types of structures were observed in the gaps as well as on surface of the chromosome. Further more, other types of chromosome aberration induced by ionizing radiation visualized by AFM will be presented

  11. Microbiological problems of radiation sterilization control of disposable medical products

    International Nuclear Information System (INIS)

    Horakova, V.

    1975-01-01

    Dose-response curves were determined for three strains of cocci and seven strains of aerobic spore-forming rods after irradiation by two different 60 Co sources and Van de Graaff electron accelerator. Besides the test strains Streptococcus faecium A 2 1, Bacillus sphericus Csub(I)A and Bacillus pumilus E601, some strains isolated from irradiated vaccines and animal diets, or found among common air-contaminating bacteria and pathogenic cocci were examined. The efficiency of the used radiation sources was compared. The control of the microbiological efficiency of radiation sterilization is discussed regarding routine practice. (author)

  12. Sources of ionizing radiation in industry: licensing and control

    International Nuclear Information System (INIS)

    Dimitrov, V.

    2001-01-01

    In this paper are presented several methods, which the Inspection on the Safe Use of Atomic Energy applies for the control on the use of sources of ionizing radiation in industry. It reviews some problems, which we have to solve during our inspections. An analysis and assessment of them is done. The prescribed safety ensuring measures are discussed. (author)

  13. Combination treatment of gamma radiation and paraben in controlling spoilage of poultry meat

    International Nuclear Information System (INIS)

    Shiralkar, N.D.; Rege, D.V.

    1977-01-01

    With a view of controlling spoilage, combination treatment of poultry meat with gamma radiation and a chemical preservative has been investigated. Raw poultry pieces of about 25 g. weight were dipped in 0.1% propyl-paraben solution for two hours and were given a 0.1 Mrad dose from 60 Co gamma radiation. It was found that paraben was not affected by irradiation. The flavour evaluation scores indicated the shelf-life of poultry meat was prolonged by a couple of days as compared to untreated controls in refrigerated storage. (M.G.B.)

  14. Control of zebra mussels with ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, D.P.

    1998-07-01

    This paper presents the results of research on the effects of low and medium pressure ultraviolet (UV) radiation on zebra mussel mortality carried out between 1992 and 1995. An initial 1992 study, carried out by Aquatic Sciences (ASI), showed that flow-through UV systems have the ability to kill zebra mussels and prevent them from attaching to downstream surfaces. However, this work did not include expanded testing to determine the limitations of UV radiation at higher flow rates or to further define effective working parameters. The 1994 study was carried out at the Lennox Thermal Generating Station (TGS) of Ontario Hydro in Kingston, Ontario. This study involved the testing of two open channel UV systems (medium and low pressure) in an effort to determine flow rates and volumes for which UV disinfection would be effective and practical for the prevention of zebra mussel infestation. It was recommended that medium pressure (MP) and low pressure (LP) UV systems be tested for their ability to control downstream settlement of zebra mussels, in flow-through trials.

  15. Potential of Glassy Carbon and Silicon Carbide Photonic Structures as Electromagnetic Radiation Shields for Atmospheric Re-entry

    Science.gov (United States)

    Komarevskiy,Nikolay; Shklover, Valery; Braginsky, Leonid; Hafner, Christian; Lawson, John W.

    2012-01-01

    During high-velocity atmospheric entries, space vehicles can be exposed to strong electromagnetic radiation from ionized gas in the shock layer. Glassy carbon (GC) and silicon carbide (SiC) are candidate thermal protection materials due to their high melting point and also their good thermal and mechanical properties. Based on data from shock tube experiments, a significant fraction of radiation at hypersonic entry conditions is in the frequency range from 215 to 415 THz. We propose and analyze SiC and GC photonic structures to increase the reflection of radiation in that range. For this purpose, we performed numerical optimizations of various structures using an evolutionary strategy. Among the considered structures are layered, porous, woodpile, inverse opal and guided-mode resonance structures. In order to estimate the impact of fabrication inaccuracies, the sensitivity of the reflectivity to structural imperfections is analyzed. We estimate that the reflectivity of GC photonic structures is limited to 38% in the aforementioned range, due to material absorption. However, GC material can be effective for photonic reflection of individual, strong spectral line. SiC on the other hand can be used to design a good reflector for the entire frequency range.

  16. Development of environmental radiation control technology

    International Nuclear Information System (INIS)

    Kim, Ingyu; Kim, Enhan; Keum, Dongkwon

    2012-04-01

    To develop the comprehensive environmental radiation management technology, - An urban atmospheric dispersion model and decision-aiding model have been developed. - The technologies for assessing the radiation impact to non-human biota and the environmental medium contamination have developed. - The analytical techniques of the indicator radionuclides related to decommissioning of nuclear facilities and nuclear waste repository have been developed. - The national environmental radiation impact has been assessed, and the optimum management system of natural radiation has been established

  17. Radiation sterilisation - a contract steriliser's view

    International Nuclear Information System (INIS)

    Woolston, J.

    1995-01-01

    Radiation processing is based on two characteristics of high energy radiations namely their ability to kill micro-organisms and their ability to modify polymer structure. Contract radiation plants are particularly prominent in the application of radiation processing, accounting for approx. 33% of gamma plants world wide and over 50% of installed Cobalt 60. Amongst contract radiation plants Globally sterilisation will account for some 70-80% of gamma plant revenues with 20-30% being associated with other microbiological control activities. Individual plants however will show significant variation. Total volumes of sterile product generated by contract gamma plants are estimated at approx. 1.5-2.0 m3 per annum. Chemical modification generally forms a small proportion of their activity in value or volume terms although the high dosages generally required for polymer modification may result in a larger proportion of process time. Non-sterilisation irradiation services based on microbiological control are provided for a variety of industries particularly pharmaceutical raw material, food packaging and pharmaceutical packaging and food itself. (author)

  18. General problems associated with the control and safe use of radiation sources (199)

    International Nuclear Information System (INIS)

    Ahmed, J.U.

    1993-01-01

    There are problems at various levels in ensuring safety in the use of radiation sources. A relatively new problem that warrants international action is the smuggling of radioactive material across international borders. An international convention on the control and safe use of radiation sources is essential to provide a universally harmonized mechanism for ensuring safety

  19. The radiation exposure control programme - its effect on design

    International Nuclear Information System (INIS)

    Simmons, R.B.V.

    1975-01-01

    The paper discusses how the Power Projects design organization has responded to the problem of operational exposure. This response took the form of an organized formal Programme developed during the Bruce G.S. design phase. This Radiation Exposure Control Programme considered: radiation conditions, number of items requiring attention, number of occasions item requires attention and manhours involved on each occasion. Analysis of these factors and comparison with target values enabled worthwhile reductions to be made in estimated operating exposure. Activity transport studies, reliability and design detail improvements have all received an impetus from the Programme. The Programme which has value both from the economic and the health physics points of view is now a continuing feature of the CANDU plant design process. (author)

  20. Radiation exposure and central nervous system cancers: A case-control study among workers at two nuclear facilities

    International Nuclear Information System (INIS)

    Carpenter, A.V.; Flanders, W.D.; Frome, E.L.; Crawford-Brown, D.J.; Fry, S.A.

    1987-03-01

    A nested case-control study was conducted among workers employed between 1943 and 1977 at two nuclear facilities to investigate the possible association of primary malignant neoplasms of the central nervous system (CNS) with occupational exposure to ionizing radiation from external and internal sources. Eighty-nine white male and female workers, who according to the information on death certificates dies of primary CNS cancers, were identified as cases. Four matched controls were selected for each case. External radiation exposure data were available from film badge readings for individual workers, whereas radiation dose to lung from internally deposited radionuclides, mainly uranium, was estimated from area and personnel monitoring data and was used in analyses in lieu of the dose to the brain. Matched sets were included in the analyses only if information was available for the case and at least one of the corresponding controls. Thus, the analyses of external radiation included 27 cases and 90 matched controls, and 47 cases and 120 matched controls were analyzed for the effects of radiation from internally deposited uranium. No association was observed between deaths fron CNS cancers and occupational exposure to ionizing radiation from external or internal sources. However, due to the small number of monitored subjects and low doses, a weak association could not be ruled out. 43 refs., 1 fig., 15 tabs

  1. Structural studies of the lipid membranes at the Siberia-2 synchrotron radiation source

    International Nuclear Information System (INIS)

    Kiselev, M. A.; Ermakova, E. V.; Ryabova, N. Yu.; Nayda, O. V.; Zabelin, A. V.; Pogorely, D. K.; Korneev, V. N.; Balagurov, A. M.

    2010-01-01

    Lipid membranes are a subject of contemporary interdisciplinary studies at the junction of biology, biophysics, pharmacology, and bionanotechnology. The results of the structural studies of several types of lipid membranes by the lamellar and lateral diffraction of X-ray synchrotron radiation are presented. The experiments were performed at the Mediana and DICSI stations of the Siberia-2 synchrotron radiation source at the Russian Research Center Kurchatov Institute. The data obtained are compared with the results of studying lipid membranes at the small-angle scattering beamlines D22 and D24 at LURE (France) and at the A2 beamline at DESY (Germany). The parameters of the DICSI station are shown to meet the basic requirements for the structural study of lipid systems, which are of fundamental and applied interest.

  2. Radiation-pressure-mediated control of an optomechanical cavity

    Science.gov (United States)

    Cripe, Jonathan; Aggarwal, Nancy; Singh, Robinjeet; Lanza, Robert; Libson, Adam; Yap, Min Jet; Cole, Garrett D.; McClelland, David E.; Mavalvala, Nergis; Corbitt, Thomas

    2018-01-01

    We describe and demonstrate a method to control a detuned movable-mirror Fabry-Pérot cavity using radiation pressure in the presence of a strong optical spring. At frequencies below the optical spring resonance, self-locking of the cavity is achieved intrinsically by the optomechanical (OM) interaction between the cavity field and the movable end mirror. The OM interaction results in a high rigidity and reduced susceptibility of the mirror to external forces. However, due to a finite delay time in the cavity, this enhanced rigidity is accompanied by an antidamping force, which destabilizes the cavity. The cavity is stabilized by applying external feedback in a frequency band around the optical spring resonance. The error signal is sensed in the amplitude quadrature of the transmitted beam with a photodetector. An amplitude modulator in the input path to the cavity modulates the light intensity to provide the stabilizing radiation pressure force.

  3. Quality Control and Quality Assurance of Radiation Oncology

    International Nuclear Information System (INIS)

    Abaza, A.

    2016-01-01

    Radiotherapy (RT) has played important roles in cancer treatment for more than one century. The development of RT techniques allows high-dose irradiation to tumors while reducing the radiation doses delivered to surrounding normal tissues. However, RT is a complex process and involves understanding of the principles of medical physics, radiobiology, radiation safety, dosimetry, radiation treatment planning, simulation and interaction of radiation with other treatment modalities. Each step in the integrated process of RT needs quality control and quality assurance (QA) to prevent errors and to ensure that patients will receive the prescribed treatment correctly. The aim of this study is to help the radio therapists in identifying a system for QA that balances patient safety and quality with available resources. Recent advances in RT focus on the need for a systematic RT QA program that balances patient safety and quality with available resources. It is necessary to develop more formal error mitigation and process analysis methods, such as failure mode and effect analysis (FMEA), to focus available QA resources optimally on the process components. External audit programs are also effective. Additionally, Clinical trial QA has a significant role in enhancing the quality of care. The International Atomic Energy Agency (IAEA) has operated both an on-site and off-site postal dosimetry audit to improve practice and to assure the dose from RT equipment. Both postal dosimetry audit and clinical trial RTQA, especially for advanced technologies, in collaboration with global networks, will serve to enhance patient safety and quality of care

  4. Radiation Dosimetry for Quality Control of Food Preservation and Disinfestation

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, Arne; Uribe, R.M.

    1983-01-01

    In the use of x and gamma rays and scanned electron beams to extend the shelf life of food by delay of sprouting and ripening, killing of microbes, and control of insect population, quality assurance is provided by standardized radiation dosimetry. By strategic placement of calibrated dosimeters...

  5. Achievements and perspectives for radiation processing

    International Nuclear Information System (INIS)

    Charlcsby, A.

    1992-01-01

    In the last few decades the major practical applications of large radiation sources have been in the irradiation of macromolecular systems. These have risen rapidly to annual outputs of billions of dollars and continue to show steady growth. In other directions such as polymerization and grafting, radiation has been less successful, primarily because in these subjects radiation serves as only one step in a sequence of chemical reactions, and often these can be achieved by more conventional and familiar methods. We envisage future progress along several distinct lines. 1. Reduction in the cost of radiation. 2. The application of radiation technology in areas where valuable modifications are involved and where advantage can be taken of the remarkable control offered by electron beams. 3. Areas where the chemical alternatives do not exist or are difficult to apply. 4. A very different line of approach is to use radiation with its far more complete control and reproducibility to investigate many processes even if in the production stage itself a different technique is later utilized. Present examples are chemical kinetics as with ESR, pulse radiolysis, pulsed NMR, behavior of trapped charges, crystal structure, local modifications, reinforcement and orientation etc. (J.P.N.)

  6. Control of occupational radiation exposures in TVA nuclear power plants - design and operating philosophy

    International Nuclear Information System (INIS)

    Belvin, E.A.; Lyon, M.; Beasley, E.G. Jr.; Zobel, W.; Stone, G.F.

    1976-01-01

    TVA has some 21,000 MWe of nuclear generation in various phases of design, construction, or operation. When Browns Ferry was designed in the late 1960's, there were no guidelines available regarding implant radiation control features, so TVA relied on good engineering and health physics judgement in developing its design and operating criteria for radiation protection. After two years of operation at Browns Ferry, the authors experience shows that their design criteria were in most cases adequate or more than adequate. However, several areas present continuing problems relative to radiation and contamination control. In view of the recent NRC ALARA guidelines, they have instituted a program to ensure that the ALARA concept is made an integral part of their design and operating plans. Administrative documents were issued giving management support to the ALARA concept. A 4-member management audit team consisting of representatives from their design, operating, and radiation protection groups was established to review the effectiveness of radiation protection design features and operating activities on a plant-by-plant basis. Reports and recommendations from these audits are sent to top-level management staff. Their goal is to maintain an audit-appraisal system consisting of in-plant awareness of radiation and contamination conditions, assessment of trends in occupational radiation exposures, and feedback to their designers regarding problems encountered during operation and maintenance activities

  7. Establishment of an X radiation equipment quality control programme using non invasive meters

    International Nuclear Information System (INIS)

    Lucena, Rodrigo Ferreira de

    2010-01-01

    The objective of this work was to study the behavior of the mainly X ray equipment calibration laboratory of IPEN, operated in the range from 25 kV to 150 kV using a PTW non invasive meter, model Diavolt TM , and an ORTEC spectrometry system, model NOMAD-PLUS 92X, for the establishment of a quality control programme. The Diavolt meter was used for measurements of air kerma, peak voltage and practical peak voltage. The measurements were made varying parameters such as electrical current, X radiation quality for radiation diagnostic, angulations of the meter and its distance in relation to the focal spot of the X ray tube. The results were compared with data found in the literature. Several spectra were generated with the spectrometer system with the purpose of determine the peak voltage in function of the nominal voltage and to characterize the radiation qualities for radiation diagnostic previously determined. The established quality control programme enables the management of the appropriate functioning of the measurement instruments (ionization chambers, voltage and current meter and spectrometer) as well as of the X radiation system. This work also has proposed a time interval to run each one of the tests. (author)

  8. Pest control of ligniperdous insects by means of ionizing radiation

    International Nuclear Information System (INIS)

    Baer, M.; Koehler, W.

    1983-01-01

    Wooden objects of art and monuments are endangered by wood-destroying insects. The treatment of these objects with ionizing radiation is one way to control these pests. For this purpose the portable HWK-3 high-dose irradiation device was developed. In July 1979, a radiation experiment was made under field conditions in Potsdam-Sanssouci in order to gain experience in the operation and effectiveness of the new device. During the following 18 months the results of this experiment were evaluated by means of the SM 231 vibration measuring instrument. It became evident that a total dose of over 3 kGy would kill all of the death-watch beetles (Anobium punctatum de Geer) and doses down to 0.55 kGy would largely diminish the population, with future damages caused by death-watch beetles being highly unlikely. Delayed damages in the larvae caused by low total doses still add to the effectiveness of the pest control. (author)

  9. Plasmonic Control of Radiation and Absorption Processes in Semiconductor Quantum Dots

    Energy Technology Data Exchange (ETDEWEB)

    Paiella, Roberto [Boston Univ., MA (United States); Moustakas, Theodore D. [Boston Univ., MA (United States)

    2017-07-31

    This document reviews a research program funded by the DOE Office of Science, which has been focused on the control of radiation and absorption processes in semiconductor photonic materials (including III-nitride quantum wells and quantum dots), through the use of specially designed metallic nanoparticles (NPs). By virtue of their strongly confined plasmonic resonances (i.e., collective oscillations of the electron gas), these nanostructures can concentrate incident radiation into sub-wavelength “hot spots” of highly enhanced field intensity, thereby increasing optical absorption by suitably positioned absorbers. By reciprocity, the same NPs can also dramatically increase the spontaneous emission rate of radiating dipoles located within their hot spots. The NPs can therefore be used as optical antennas to enhance the radiation output of the underlying active material and at the same time control the far-field pattern of the emitted light. The key accomplishments of the project include the demonstration of highly enhanced light emission efficiency as well as plasmonic collimation and beaming along geometrically tunable directions, using a variety of plasmonic excitations. Initial results showing the reverse functionality (i.e., plasmonic unidirectional absorption and photodetection) have also been generated with similar systems. Furthermore, a new paradigm for the near-field control of light emission has been introduced through rigorous theoretical studies, based on the use of gradient metasurfaces (i.e., optical nanoantenna arrays with spatially varying shape, size, and/or orientation). These activities have been complemented by materials development efforts aimed at the synthesis of suitable light-emitting samples by molecular beam epitaxy. In the course of these efforts, a novel technique for the growth of III-nitride quantum dots has also been developed (droplet heteroepitaxy), with several potential advantages in terms of compositional and geometrical

  10. Radiation damage of silicon structures with electrons of 900 MeV

    CERN Document Server

    Rachevskaia, I; Bosisio, L; Dittongo, S; Quai, E; Rizzo, G

    2002-01-01

    We present first results on the irradiation of double-sided silicon microstrip detectors and test structures performed at the Elettra synchrotron radiation facility at Trieste, Italy. The devices were irradiated with 900 MeV electrons. The test structures we used for studying bulk, surface and oxide irradiation damage were guard ring diodes, gated diodes and MOS capacitors. The test structures and the double-sided microstrip detectors were produced by Micron Semiconductor Ltd. (England) and IRST (Trento, Italy). For the first time, bulk-type inversion is observed to occur after high-energy electron irradiation. Current and inter-strip resistance measurements performed on the microstrip detectors show that the devices are still usable after type inversion.

  11. A case-control study of nasopharyngeal carcinoma among inhabitants in high background radiation areas of Yangjiang, China

    International Nuclear Information System (INIS)

    Zou Jianming; Sun Quanfu; Yuan Yongling

    1999-01-01

    Objective: The purpose of the study was to confirm and explore main risk factors of nasopharyngeal carcinoma (NPC) in cohort members of the investigated areas, and evaluate effects of confounding factors on cancer risk associated with exposure to high background radiation. Methods: The deceased cases of NPC during the period of 1987-1995 were selected as study subjects for each of whom two controls were randomly selected from potential control subjects who died from causes other than malignant tumors and external causes, and matched for sex and years of birth and death (within 5 years). Using structure questionnaire, the relevant information including socioeconomic status, dietary habits, smoking and alcohol consumption, history of illness, agricultural use of pesticide, medical X-ray exposure and familial history of NPC were collected. The odds ratio (OR) was used as a measure of association between NPC and the risk factors. Results: 102 cases and 202 controls were successfully investigated. Single factor conditional logistic regression analysis showed that the occurrence of NPC was closely positively associated with intake of salted fish, pickles, fermented soybeans, cured meats, history of chronic rhinitis and familial history of NPC. Further multiple conditional logistic regression analysis turned out that intake of salted fish, history of chronic rhinits and familial history of NPC were the independent risk factors of NPC. After controlling for history of chronic rhinits and familial history of NPC, the results based on multiple conditional logistic regression analysis from high background radiation, intake of salted fish and fermented soybeans, tobacco smoking and alcohol consumption showed that only intake of salted fish was a significant risk factor (OR = 2.8, 95% CI 1.52-5.18), tobacco smoking (OR = 1.2, 95% CI 0.65-2.22), alcohol consumption (OR = 0.83, 95% CI 0.38-1.78) and exposure to high background radiation (OR= 0.86, 95% CI 0.44-1.68) did not

  12. Waste control guidelines according to the Amendment of the Radiation Protection Ordinance

    International Nuclear Information System (INIS)

    Schaefer, B.

    2003-01-01

    Up to now, the Waste Control Guidelines are considered one of the essential evaluation standards for giving an expert opinion about an application for radioactive material disposal. When the new Radiation Protection Ordinance became effective, some parts of the Waste Control Guidelines have become legal regulation. Nevertheless, the Waste Control Guidelines have not been repealed and both regulations exist simultaneously. Therefore, it is now being under discussion how a new subordinate regulation should look like. 14 years of experience with the Waste Control Guidelines have shown that it is not only desirable but necessary to have nationwide standardized regulations for the disposal of radioactive waste. In the following parts, the results of a search made by the TUeV Nord e.V. have been summed up. This search shows for which aspects legal regulation will be necessary in future as well. Those parts of the Waste Control Guidelines, which have been transferred into the Radiation Protection Ordinance, can be found in 72-75 of the Radiation Protection Ordinance. Besides this, other parts are or will be determined by other regulations (AtAV, GGVSE for transport procedures, planned regulations for intermediate storage and clearance). Furthermore, there are some aspects which have hardly been applied in every day's practice (e.g. qualified procedures). In addition to this, there all still some aspects which have to be determined by the Waste Control Guidelines. This refers to the demand for a waste disposal concept, the obligatory application of the Waste Acceptance Criteria for Final Disposal for conditioning, rules for mixing of waste as well as regulations concerning recycling and reuse of radioactive residues. (orig.)

  13. Engineering design of a Radiative Divertor for DIII-D

    International Nuclear Information System (INIS)

    Smith, J.P.; Allen, S.L.; Anderson, P.M.; Baxi, C.B.; Chin, E.; Fenstermacher, M.E.; Hill, D.N.; Hollerbach, M.A.; Hyatt, A.W.; Junge, R.; Mahdavi, M.A.; Porter, G.D.; Redler, K.; Reis, E.E.; Schaffer, M.J.; Sevier, D.L.; Stambaugh, R.D.

    1995-01-01

    A new divertor called the Radiative Divertor is presently being designed for the DIII-D tokamak. Input from tokamak experiments and modeling form the basis for the new design. The Radiative Divertor is intended to reduce the heat flux on the divertor plates by dispersing the power with radiation. Gas puffing experiments in the current open divertor have shown a reduction of the divertor heat flux with either deuterium or impurity puffing. However, either the plasma density (D 2 ) or the core Z eff (impurities) increases in these experiments. The radiative divertor uses a slot structure to isolate the divertor plasma region from the area surrounding the core plasma. Modeling has shown that the Radiative Divertor hardware will provide better baffling and particle control and thereby minimize the effect of the gas puffing in the divertor region on the plasma core. In addition, the Radiative Divertor structure will allow density control in plasma shapes with high triangularity (>0.8) required for advanced tokamak operation. The divertor structure allows for operation in either double or single-null plasma configurations. Four independently controlled divertor cryopumps will enable pumping at either the inboard (upper and lower) or the outboard (upper and lower) divertor plates. Biasing is an integral part of the design and is based on experience at the Tokamak de Varennes (TdeV) and DIII-D. Boron nitride tiles electrically insulate the inner and outer strike points and a low current electrode is used to apply a radial electric field to the scrape-off layer. TdeV has shown that biasing can provide particle and impurity control. The design is extremely flexible, and will allow physics studies of the effect of slot width and height. This is extremely important, as the amount of chamber volume needed for the divertor in future machines such as International Thermonuclear Experiment Reactor (ITER) and Tokamak Physics Experiment (TPX) must be determined. (orig./WL)

  14. Enhanced non-radiative energy transfer in hybrid III-nitride structures

    International Nuclear Information System (INIS)

    Smith, R. M.; Athanasiou, M.; Bai, J.; Liu, B.; Wang, T.

    2015-01-01

    The effect of surface states has been investigated in hybrid organic/inorganic white light emitting structures that employ high efficiency, nearfield non-radiative energy transfer (NRET) coupling. The structures utilize blue emitting InGaN/GaN multiple quantum well (MQW) nanorod arrays to minimize the separation with a yellow emitting F8BT coating. Surface states due to the exposed III-nitride surfaces of the nanostructures are found to reduce the NRET coupling rate. The surface states are passivated by deposition of a silicon nitride layer on the III-nitride nanorod surface leading to reduced surface recombination. A low thickness surface passivation is shown to increase the NRET coupling rate by 4 times compared to an un-passivated hybrid structure. A model is proposed to explain the increased NRET rate for the passivated hybrid structures based on the reduction in surface electron depletion of the passivated InGaN/GaN MQW nanorods surfaces

  15. Regulatory infrastructure for the control of radiation sources in the Africa region: Status, needs and programmes

    International Nuclear Information System (INIS)

    Skornik, K.

    2001-01-01

    In recent years, several African countries have taken steps towards creating or strengthening legal, administrative and technical mechanisms for the regulation and control of peaceful uses of nuclear technology, and towards improving the effectiveness and sustainability of radiation protection measures based on international standards. This stems from a growing awareness that a proper national infrastructure is a prerequisite for the implementation of safety standards to achieve and maintain the desired level of protection and safety, particularly in such sectors as public health and industry. Also, other issues of global and regional interest, such as the control of radiation sources, including the handling of hazardous waste, and response capabilities in the case of a radiological emergency, have contributed to a better perception of risks associated with deficiencies in or lack of adequate national radiation protection control mechanisms. Too often, however, this awareness has not been matched with adequate progress in the establishment of a regulatory framework for the control of radiation sources. This paper presents a summary of the current status of radiation protection infrastructure in all African Member States. On a background of still existing weaknesses and challenges, an overview of the Agency's response to assistance needs and programmes in this field is discussed. (author)

  16. Controlling radiation fields in siemans designed light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Riess, R.; Marchl, T. [Siemens Power Generation Group, Erlangen (Germany)

    1995-03-01

    An essential item for the control of radiation fields is the minimization of the use of satellites in the reactor systems of Light Water Reactors (LWRs). A short description of the qualification of Co-replacement materials will be followed by an illustration of the locations where these materials were implemented in Siemens designed LWRs. Especially experiences in PWRs show the immense influence of reduction of cobalt sources on dose rate buildup. The corrosion and the fatique and wear behavior of the replacement materials has not created concern up to now. A second tool to keep occupational radiation doses at a low level in PWRs is the use of the modified B/Li-chemistry. This is practized in Siemens designed plants by keeping the Li level at a max. value of 2 ppm until it reaches a pH (at 300{degrees}C) of {approximately}7.4. This pH is kept constant until the end of the cycle. The substitution of cobalt base alloys and thus the removal of the Co-59 sources from the system had the largest impact on the radiation levels. Nonetheless, the effectiveness of the coolant chemistry should not be neglected either. Several years of successful operation of PWRs with the replacement materials resulted in an occupational radiation exposure which is below 0.5 man-Sievert/plant and year.

  17. Carbon Structure Hazard Control

    Science.gov (United States)

    Yoder, Tommy; Greene, Ben; Porter, Alan

    2015-01-01

    Carbon composite structures are widely used in virtually all advanced technology industries for a multitude of applications. The high strength-to-weight ratio and resistance to aggressive service environments make them highly desirable. Automotive, aerospace, and petroleum industries extensively use, and will continue to use, this enabling technology. As a result of this broad range of use, field and test personnel are increasingly exposed to hazards associated with these structures. No single published document exists to address the hazards and make recommendations for the hazard controls required for the different exposure possibilities from damaged structures including airborne fibers, fly, and dust. The potential for personnel exposure varies depending on the application or manipulation of the structure. The effect of exposure to carbon hazards is not limited to personnel, protection of electronics and mechanical equipment must be considered as well. The various exposure opportunities defined in this document include pre-manufacturing fly and dust, the cured structure, manufacturing/machining, post-event cleanup, and post-event test and/or evaluation. Hazard control is defined as it is applicable or applied for the specific exposure opportunity. The carbon exposure hazard includes fly, dust, fiber (cured/uncured), and matrix vapor/thermal decomposition products. By using the recommendations in this document, a high level of confidence can be assured for the protection of personnel and equipment.

  18. The Use of Radiation-Induced Degradation in Controlling Molecular Weights of Polysaccharides : The Effect of Humidity

    International Nuclear Information System (INIS)

    Sen, M.

    2006-01-01

    Better understanding of chemistry of radiation-induced degradation is becoming of increasing importance on account of the utilization of polymeric materials in a variety of radiation environments as well as beneficial uses of degraded polymers. It is very well known that polysaccharides in dry form or in solution degrade when exposed to ionizing radiation. In this study degrading effect of radiation has been considered from the point of view of controlling the molecular weights of kappa- and iota-carrageenans and sodium alginate irradiated under varying environmental conditions. The humidity equilibrated polymer samples kept over saturated aqueous salt solutions of NaCl, NaNO 3 and MgCl 2 were irradiated in a Gammacell 220 at room temperature. The degradation was investigated in detail by a careful Gel Permeation Chromatographic analysis of their respective molecular weights before and after irradiation Alexander-Charlesby-Ross equation was used in determining their radiation-chemical yields. Degradation yield is the highest for dry irradiated kappa- (G(S) = 0.73) and iota-carrageenans (G(S) = 2.43) and with small amount of water taken up from surrounding humidity degradation becomes less pronounced and G(S) values show a decrease down to G(S) = 0.16 and 0.87 at 75 % relative humidity, respectively. At very high water contents degradation effect again becomes more effective. Sodium alginate has fount to be less sensitive to the effect of humidity. When there is small amount of water in the polysaccharide structure, it is unlikely to expect an indirect effect of radiation. The water located in between the polymer chains however can give enough mobility to kappa and iota karrageenans chains, plastifying effect, which may enhance the radical-radical combinations thus lowering the rate of degradation hence reducing G(S) values

  19. Atoms, Radiation, and Radiation Protection

    CERN Document Server

    Turner, James E

    2007-01-01

    Atoms, Radiation, and Radiation Protection offers professionals and advanced students a comprehensive coverage of the major concepts that underlie the origins and transport of ionizing radiation in matter. Understanding atomic structure and the physical mechanisms of radiation interactions is the foundation on which much of the current practice of radiological health protection is based. The work covers the detection and measurement of radiation and the statistical interpretation of the data. The procedures that are used to protect man and the environment from the potential harmful effects of

  20. Toxic agent and radiation control: meeting the 1990 objectives for the nation

    International Nuclear Information System (INIS)

    Rall, D.P.

    1984-01-01

    Toxic agent and radiation control is 1 of the 15 health priority areas addressed through the Public Health Service's Objectives for the Nation. Several gains in moving toward the 1990 goals for toxic agent and radiation control have been recorded. Research and technical assistance, combined with legislation to reduce the amount of lead in gasoline, have contributed to a decrease in the mean blood lead level of the general population. New testing procedures have been developed to evaluate both reproductive and developmental toxicities of chemicals. Educational implementation of pelvimetry referral criteria in a multiyear study involving approximately 200 U.S. hospitals has resulted in a 50 percent reduction in the number of pelvimetries performed. Health-related responses have been given to environmental problems such as exposures to polychlorinated biphenyls (PCBs) in Massachusetts and Florida and exposures to dioxin in Missouri and New Jersey. Chemical records for some 1000 compounds likely to occur in chemical dumps or in bulk transit are being either created or updated to enhance online data retrieval services. For the foreseeable future, however, improvement of knowledge of the potential health risk posed by toxic chemicals and radiation must remain one of the most important priorities. To control toxic agents, development of surveillance systems and data bases are equally important

  1. The latest radiation instrument

    International Nuclear Information System (INIS)

    Kang, Se Sik; Gwon, Dal Gwan; Kim, Gyeong Geum

    2008-08-01

    This book deals with the latest radiation instrument, which is comprised of eight chapters. It explains X rays instrument for medial treatment, X-ray tube instrument and permissible burden with its history, structure and characteristic high voltage apparatus with high voltage rectifier circuit, X-ray control apparatus for medical treatment, X-ray image equipment X-ray television apparatus and CCD 205, X-ray apparatus of install and types, Digital X-ray apparatus with CR 261 and DR 269, performance management on X-ray for medical treatment with its history, necessity and management in the radiation field.

  2. Active and passive vibration control of structures

    CERN Document Server

    Spelsberg-Korspeter, Gottfried

    2014-01-01

    Active and Passive Vibration Control of Structures form an issue of very actual interest in many different fields of engineering, for example in the automotive and aerospace industry, in precision engineering (e.g. in large telescopes), and also in civil engineering. The papers in this volume bring together engineers of different background, and it fill gaps between structural mechanics, vibrations and modern control theory.  Also links between the different applications in structural control are shown.

  3. Structural design of the DIII-D radiative divertor

    International Nuclear Information System (INIS)

    Reis, E.E.; Smith, J.P.; Baxi, C.B.; Bozek, A.S.; Chin, E.; Hollerbach, M.A.; Laughon, G.J.; Sevier, D.L.

    1996-10-01

    The divertor of the DIII-D tokamak is being modified to operate as a slot type, dissipative divertor. This modification, called the Radiative Divertor Program (RDP) is being carried out in two phases. The design and analysis is complete and hardware is being fabricated for the first phase. This first phase consists of an upper divertor baffle and cryopump to provide some density control for high triangularity, single or double null discharges. Installation of the first phase is scheduled to start in October, 1996. The second phase provides pumping at all four divertor strike points of double null high triangularity discharges and baffling of the neutral particles from transport back to the core plasma. Studies of the effects of varying the slot length and width of the divertor can be easily accomplished with the design of RDP hardware. Static and dynamic analyses of the baffle structures, new cryopumps, and feedlines were performed during the preliminary and final design phases. Disruption loads and differential thermal displacements must be accommodated in the design of these components. With the full RDP hardware installed, the plasma current in DIII-D will be a maximum of 3.0 MA. Plasma disruptions induce toroidal currents in the cryopump, producing complex dynamic loads. Simultaneously, the vacuum vessel vibrations impose a sinusoidal base excitation to the supports for the cryopump. Static and dynamic analyses of the cryopump demonstrate that the stresses due to disruption and thermal loadings satisfy the stress and deflection criteria

  4. Side effects and opioid addiction in radiation-induced mucositis pain control in head and neck cancer

    International Nuclear Information System (INIS)

    Takahashi, Atsuhito; Shoji, Kazuhiko; Mizuta, Masanobu; Morita, Mami; Iki, Takehiro; Kojima, Tsuyoshi

    2011-01-01

    Radiation therapy in head and neck malignancy may trigger mucositis poorly controlled by nonsteroidal antiinflammatory drugs (NSAIDs). Having already reported early opioid efficacy in radiation-induced mucositis pain in head and neck cancer, we discuss whether this resulted in severe side effects and opioid addiction. Of 11 persons (26.2%) with nausea, 3 could not tolerate opioid. Of 33 (78.6%) with constipation, all were controlled by purgatives. Seven had mild sleepiness. None had severe opioid side effects in radiation-induced mucositis pain treatment, but I showed opioid dependence after 128-days opioid administration. While opioid administration in radiation-induced mucositis pain may not cause addiction, lomg-term opioid use should be carefully monitored. (author)

  5. A quality control program for the thermoluminescence dosimeter (TLD) in personnel radiation monitoring

    International Nuclear Information System (INIS)

    Seo, Kyung Won; Kim, Jang Lyul; Lee, Sang Yoon; Lee, Hyung Sub

    1994-01-01

    High quality radiation dosimetry is essential for workers who rely upon personal dosemeters to record the amount of radiation to which they are exposed. The ministry of science and technology (MOST) issued a ministerial ordinance (No 199-15) about the technical criteria on personnel dosimeter processors on 1992. The purpose of this quality control program is to prescribe the procedures approved by the management of KAERI for implementing a quality badge service by means of TLD for personnel working in an area where they may be exposed to ionization radiation. (Author) 10 refs

  6. Partially acoustic dark matter, interacting dark radiation, and large scale structure

    Energy Technology Data Exchange (ETDEWEB)

    Chacko, Zackaria [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Cui, Yanou [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Department of Physics and Astronomy, University of California-Riverside,University Ave, Riverside, CA 92521 (United States); Perimeter Institute, 31 Caroline Street, North Waterloo, Ontario N2L 2Y5 (Canada); Hong, Sungwoo [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Okui, Takemichi [Department of Physics, Florida State University,College Avenue, Tallahassee, FL 32306 (United States); Tsai, Yuhsinz [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States)

    2016-12-21

    The standard paradigm of collisionless cold dark matter is in tension with measurements on large scales. In particular, the best fit values of the Hubble rate H{sub 0} and the matter density perturbation σ{sub 8} inferred from the cosmic microwave background seem inconsistent with the results from direct measurements. We show that both problems can be solved in a framework in which dark matter consists of two distinct components, a dominant component and a subdominant component. The primary component is cold and collisionless. The secondary component is also cold, but interacts strongly with dark radiation, which itself forms a tightly coupled fluid. The growth of density perturbations in the subdominant component is inhibited by dark acoustic oscillations due to its coupling to the dark radiation, solving the σ{sub 8} problem, while the presence of tightly coupled dark radiation ameliorates the H{sub 0} problem. The subdominant component of dark matter and dark radiation continue to remain in thermal equilibrium until late times, inhibiting the formation of a dark disk. We present an example of a simple model that naturally realizes this scenario in which both constituents of dark matter are thermal WIMPs. Our scenario can be tested by future stage-IV experiments designed to probe the CMB and large scale structure.

  7. Partially acoustic dark matter, interacting dark radiation, and large scale structure

    International Nuclear Information System (INIS)

    Chacko, Zackaria; Cui, Yanou; Hong, Sungwoo; Okui, Takemichi; Tsai, Yuhsinz

    2016-01-01

    The standard paradigm of collisionless cold dark matter is in tension with measurements on large scales. In particular, the best fit values of the Hubble rate H 0 and the matter density perturbation σ 8 inferred from the cosmic microwave background seem inconsistent with the results from direct measurements. We show that both problems can be solved in a framework in which dark matter consists of two distinct components, a dominant component and a subdominant component. The primary component is cold and collisionless. The secondary component is also cold, but interacts strongly with dark radiation, which itself forms a tightly coupled fluid. The growth of density perturbations in the subdominant component is inhibited by dark acoustic oscillations due to its coupling to the dark radiation, solving the σ 8 problem, while the presence of tightly coupled dark radiation ameliorates the H 0 problem. The subdominant component of dark matter and dark radiation continue to remain in thermal equilibrium until late times, inhibiting the formation of a dark disk. We present an example of a simple model that naturally realizes this scenario in which both constituents of dark matter are thermal WIMPs. Our scenario can be tested by future stage-IV experiments designed to probe the CMB and large scale structure.

  8. Effect of genes controlling radiation sensitivity on chemical mutagenesis in yeast

    International Nuclear Information System (INIS)

    Prakash, L.

    1975-01-01

    Ultraviolet radiation, x radiation, nitrogen mustard, methyl methanesulfonate, and dimethyl sulfate were found to revert all the tester strains with the same efficiency or without any dependence on simple types of base-pair changes, and it was concluded that these mutagens were nonspecific in the types of base-pair changes produced. The cycl-131 tester was used in studies designed to determine the genetic control of mutation induction using a variety of mutagens. The rad 6 and rad g genes greatly reduce the frequency of chemically induced reversion of cycl-131

  9. Mitigating HZE Radiation-Induced Deficits in Marrow-Derived Mesenchymal Progenitor Cells and Skeletal Structure

    Science.gov (United States)

    Globus, Ruth K.; Schreurs, Ann-Sofie; Shirazi-Fard, Yasaman; Terada, Masahiro; Alwood, Joshua; Halloran, Bernard; Tahimic, Candice

    2016-01-01

    Future long-duration space exploration beyond the earths magnetosphere will increase human exposure to space radiation and associated risks to skeletal health. We hypothesize that oxidative stress resulting from radiation exposure causes progressive bone loss and dysfunction in associated tissue. In animal studies, increased free radical formation is associated with pathological changes in bone structure, enhanced bone resorption, reduced bone formation and decreased bone mineral density, which can lead to skeletal fragility.

  10. Bioavailable serum estradiol may alter radiation risk of postmenopausal breast cancer: a nested case-control study.

    Science.gov (United States)

    Grant, Eric J; Cologne, John B; Sharp, Gerald B; Eguchi, Hidetaka; Stevens, Richard G; Izumi, Shizue; Kim, Young-Min; Berrington de González, Amy; Ohishi, Waka; Nakachi, Kei

    2018-02-01

    Ionizing radiation and high levels of circulating estradiol are known breast cancer carcinogens. We investigated the risk of first primary postmenopausal breast cancer in relation to the combined effects of whole-body ionizing radiation exposure and prediagnostic levels of postmenopausal sex hormones, particularly bioavailable estradiol (bE 2 ). A nested case-control study of 57 incident breast cancer cases matched with 110 controls among atomic bomb survivors. Joint effects of breast radiation dose and circulating levels of sex hormones were assessed using binary regression and path analysis. Radiation exposure, higher levels of bE 2 , testosterone and progesterone, and established reproductive risk factors were positively associated with postmenopausal breast cancer risk. A test for mediation of the effect of radiation via bE 2 level suggested a small (14%) but significant mediation (p = 0.004). The estimated interaction between radiation and bE 2 was large but not significant (interaction = 3.86; p = 0.32). There is accumulating evidence that ionizing radiation not only damages DNA but also alters other organ systems. While caution is needed, some portion of the radiation risk of postmenopausal breast cancer appeared to be mediated through bE 2 levels, which may be evidence for cancer risks due to both direct and indirect effects of radiation.

  11. Radiation Protection and Control Act, 1982 (South Australia) No.49 of 29 April 1982

    International Nuclear Information System (INIS)

    1982-01-01

    This Act provides for the control of activities related to radioactive substances and radiation apparatus as well as for protection against the harmful effects of ionizing radiation. It also amends the Health Act, 1935-1980 by deleting certain provisions concerning, inter alia, radioactive substances and radiation apparatus. The Act states as its general objective that the competent authorities in the exercise of their duties and any person carrying on activities involving radioactive substances and equipment emitting ionizing radiation shall try to ensure that exposure of persons to ionizing radiation is kept as low as reasonably achievable, social and economic factors being taken into account (the ALARA principle recommended by the International Commission on radiological Protection). (NEA) [fr

  12. Case-control study of congenital malformations and occupational exposure to low-level ionizing radiation

    International Nuclear Information System (INIS)

    Sever, L.E.; Gilbert, E.S.; Hessol, N.A.; McIntyre, J.M.

    1988-01-01

    In a case-control study, the authors investigated the association of parental occupational exposure to low-level external whole-body penetrating ionizing radiation and risk of congenital malformations in their offspring. Cases and controls were ascertained from births in two counties in southeastern Washington State, where the Hanford Site has been a major employer. A unique feature of this study was the linking of quantitative individual measurement of external whole-body penetrating ionizing radiation exposure of employees at the Hanford Site, using personal dosimeters, and the disease outcome, congenital malformations. The study population included 672 malformation cases and 977 matched controls from births occurring from 1957 through 1980. Twelve specific malformation types were analyzed for evidence of association with employment of the parents at Hanford and with occupational exposure to ionizing radiation. Two defects, congenital dislocation of the hip and tracheoesophageal fistula, showed statistically significant associations with employment of the parents at Hanford, but not with parental radiation exposure. Neural tube defects showed a significant association with parental preconception exposure, on the basis of a small number of cases. Eleven other defects, including Down syndrome, for which an association with radiation was considered most likely, showed no evidence of such an association. When all malformations were analyzed as a group, there was no evidence of an association with employment of the parents at Hanford, but the relation of parental exposure to radiation before conception was in the positive direction (one-tailed p value between 0.05 and 0.10). Given the number of statistical tests conducted, some or all of the observed positive correlations are likely to represent false positive findings. 30 references

  13. Vibration control of active structures an introduction

    CERN Document Server

    Preumont, Andre

    2002-01-01

    This text is an introduction to the dynamics of active structures and to the feedback control of lightly damped flexible structures. The emphasis is placed on basic issues and simple control strategies that work.

  14. 40 CFR 23.8 - Timing of Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Timing of Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978. 23.8 Section 23.8 Protection of Environment... Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978. Unless the Administrator...

  15. Effect of ionizing radiation on structural changes of energy nutrients in feeds

    International Nuclear Information System (INIS)

    Dvorak, J.; Smid, K.; Hrusovsky, J.

    1985-01-01

    For the purpose of testing the effect of ionizing radiation, feeds for dogs (meat feed mixture VETACAN and loose feed mixture VETAVIT) irradiated with 60 Co at a dose of 25 kGy/kg were studied for 60 days. It was found that the total volume of energetic and non-energetic nutrients did not change. Qualitative structure, however, displayed a significant, on the average 35% disintegration of essential amino acids, a decrease in proteins and increase in free ammoniacal bases. A significant oxidation effect of radiation is exerted on the decomposition of fats with a release of free fatty acids from the glycerol bond in a process similar to racidification (from 13.3 - 20.88 - 37.10 mg/g in meat mixture, from 103.1 - 130.04 - 135.04 mg/g in loose mixture). A certain disintegration of nutrients, only within the limits of significance, occurred also in the saccharide proportion of the loose feed mixture (acidity of water extract 348.8 - 403.99 -436.60 mg/100 g). It was proved that radiosterilization reliably secured microbiological and mycological sanitation of feeds and caused no sensory changes noticeable by human senses. It follows from the results that ionizing radiation had a pronounced antimicrobial and antimycotic effect. However, it caused significant structural changes in energetic nutrients in the feeds of animal as well as of vegetable origin. (author)

  16. Evaluation of statistical control charts for on-line radiation monitoring

    International Nuclear Information System (INIS)

    Hughes, L.D.; DeVol, T.A.

    2008-01-01

    Statistical control charts are presented for the evaluation of time series radiation counter data from flow cells used for monitoring of low levels of 99 TcO 4 - in environmental solutions. Control chart methods consisted of the 3-sigma (3σ) chart, the cumulative sum (CUSUM) chart, and the exponentially weighted moving average (EWMA) chart. Each method involves a control limit based on the detector background which constitutes the detection limit. Both the CUSUM and EWMA charts are suitable to detect and estimate sample concentration requiring less solution volume than when using a 3? control chart. Data presented here indicate that the overall accuracy and precision of the CUSUM method is the best. (author)

  17. Combination radiation-adriamycin therapy: renoprival growth, functional and structural effects in the immature mouse

    International Nuclear Information System (INIS)

    Donaldson, S.S.; Moskowitz, P.S.; Canty, E.L.; Fajardo, L.F.

    1980-01-01

    The normal tissue effects of radiation-adriamycin combination therapy were studied in the renoprival weanling mouse in an attempt to determine whether compensatory renal growth inhibition from radiation and chemotherapy could be associated with structural or functional abnormalities. Weanling BLc/sub Fl/ mice underwent unilateral nephrectomy, then single fraction renal irradiation, LD 1/21 doses of adriamycin in 5 daily doses, or combination therapy with radiation and adriamycin. Animals were sacrificed at 3, 12, and 24 weeks. Compensatory renal growth, body growth, serum blood urea nitrogen (BUN), and renal morphology by light microscopy were evaluated. Significant compensatory renal growth inhibition from radiation-adriamycin therapy exceeded that produced by adriamycin alone and radiation alone, at all time periods (p < 0.005). Body growth inhibition from radiation-adriamycin therapy or adriamycin alone significantly exceeded that produced by radiation alone (p < 0.005). Kidney and body growth inhibition from radiation-adriamycin therapy was proportionately severe. Kidney growth inhibition proportionately exceeded body growth inhibition with radiation alone; body growth inhibition proportionately exceeded kidney growth inhibition with adriamycin alone. Comparable azotemia developed by 24 weeks in both the radiation alone (p < .005) and radiation-adriamycin animals (p < 0.005), but not in the adriamycin only animals. Morphologic alterations consisting of increased glomerular density, tubular atrophy, and stromal fibrosis occurred with greater severity in the radiation-adriamycin animals than in the radiation only animals by 24 weeks; no alterations were seen in the adriamycin only animals. Using histologic criteria 750 rad plus adriamycin produced comparable injury as seen with 1000 rad alone, thus adriamycin produced an apparent dose-modifying factor of 1.33

  18. A simplified description of the three-dimensional structure of agroforestry trees for use with a radiative transfer model

    International Nuclear Information System (INIS)

    Meloni, S.

    1998-01-01

    To simulate transmitted radiation in agroforestry systems, radiative transfer models usually require a detailed three-dimensional description of the tree canopy. We propose here a simplification of the description of the three-dimensional structure of wild cherry trees (Prunus avium). The simplified tree description was tested against the detailed one for five-year-old wild cherry. It allowed accurate simulation of transmitted radiation and avoided tedious measurements of tree structure. The simplified description was then applied to older trees. Allometric relationships were used to compute the parameters not available on free-grown trees. The transmitted radiation in an agroforestry system was simulated at four different ages: 5, 10, 15 and 20 years. The trees were planted on a 5 m square grid. Two row orientations, chosen to provide different transmitted radiation patterns, were tested: north/south and north- east/south-west. The simulations showed that the daily mean transmitted radiation was reduced from 92% of incident radiation under five-year-old trees to 37% under 20-year-old trees. The variability of transmitted radiation increased with tree growth. The row orientation had only small effects on the shaded area at the beginning and end of the day when solar elevation was low. (author)

  19. The effect of early radiation in N-body simulations of cosmic structure formation

    DEFF Research Database (Denmark)

    Adamek, Julian; Brandbyge, Jacob; Fidler, Christian

    2017-01-01

    Newtonian N-body simulations have been employed successfully over the past decades for the simulation of the cosmological large-scale structure. Such simulations usually ignore radiation perturbations (photons and massless neutrinos) and the impact of general relativity (GR) beyond the background...

  20. Controlled tuning of the radiative lifetime in InAs self-assembled quantum dots through vertical ordering

    Science.gov (United States)

    Colocci, M.; Vinattieri, A.; Lippi, L.; Bogani, F.; Rosa-Clot, M.; Taddei, S.; Bosacchi, A.; Franchi, S.; Frigeri, P.

    1999-01-01

    Multilayer structures of InAs quantum dots have been studied by means of photoluminescence techniques. A strong increase of the radiative lifetime with increasing number of stacked dot layers has been observed at low temperatures. Moreover, a strong temperature dependence of the radiative lifetime, which is not present in the single layer samples, has been found in the multistacked structures. The observed effects are nicely explained as a consequence of the electronic coupling between electrons and holes induced by vertical ordering.