Three cases of radiation-induced cancer in oral regions

International Nuclear Information System (INIS)

Kawamura, Hiroshi; Shinoki, Kunihiko; Endo, Yoshitaka; Fujita, Yasushi; Hayashi, Susumu

1985-01-01

Three cases of radiation-induced cancer in the oral regions were reported with relation to radiation therapy. One was the general radiation-induced cancer following radiotherapy for the hemangioma. The other two cases, which belonged in the B-1 group of Sakai and his coworker's diagnostic criteria for radiation-induced cancer, were those occurring after radiotherapy for the malignant tumors. Due to the relatively high dosage exposure by the patient in the radiotherapy it is necessary to look out the latency of the radiation-induced cancer. After radiotherapy, careful and periodical observation is important for immediate treatment in an early stage for the radiation-induced cancer to have a favorable prognosis. In addition careful observation of the changes after radiotherapy helps in discovering the precancerous lesions from the therapy. For the radiation-induced cancer, surgical treatment would be the best, however, radiation therapy is also effective in certain cases. (author)

Radiative energy losses from a high-current air-blast arc

International Nuclear Information System (INIS)

Strachan, D.C.; Lidgate, D.; Jones, G.R.

1977-01-01

The importance of total radiation losses from high-current arcs burning in highly accelerated air flows representative of conditions existing in commercial gas-blast switchgear has been investigated. Such losses have been measured both in the high-pressure region upstream of a shaped orifice, where gas velocities are low, and in the region downstream where velocities become supersonic and pressure conditions approach ambient. The dominance of upstream electrode vapor as the source of plasma radiation losses is demonstrated and the importance of radiated losses within the arc energy balance is examined using measured values of axial electric field. For upstream electrodes of elkonite (sintered copper/tungsten) as used in high-power gas-blast circuit breakers, it is shown that some 30--40% of the electrical energy input upstream of the orifice is lost as radiation, while downstream this figure becomes 10--20%. The effect of reservoir pressure on arc electric fields is examined and the contribution to this effect of radiation losses is quantified

First Asian regional congress on radiation protection

Energy Technology Data Exchange (ETDEWEB)

Kumar, S K [Bhabha Atomic Research Centre, Bombay (India). Library and Technical Information Section

1975-12-01

Due to the rapid progress in the development of nuclear energy and its applications in medicine, agriculture and industry, the potential danger to targe groups of population due to radiation hazards has increased. Thus, radiation protection has become an important aspects of industrial and public hygiene. The article reviews the deliberations of the First Asian Regional Congress on Radiation Protection which was held during 15-20 December 1974 at the Bhabha Atomic Research Centre. 190 papers were presented on the following broad subjects: (1) organization of radiation protection services on a countrywide scale and significant problems and experiences; (2) research and cooperation, mutual assistance, education and training; (3) personnel monitoring; (4) nuclear industry risks and benefits; (5) radiation protection legislation and (6) panel discussions and regional international cooperation in the field of radiation protection.

RCA - a regional approach to radiation protection

International Nuclear Information System (INIS)

Griffith, R.; Easey, J.

1996-01-01

The Regional Cooperative Agreement (RCA) for Asia and Oceania is the oldest of four International Atomic Energy Agency Member State regional programs. Organized in 1972, 17 countries are now members of RCA - Australia, Bangladesh, Peoples Republic of China, India, Indonesia, Japan, Republic of Korea, Malaysia, Mongolia, Myanmar, New Zealand, Pakistan, Philippines, Singapore, Sri Lanka, Thailand, and Viet Nam. A number of projects related to the application of a wide range of nuclear technologies are conducted through RCA. The program is established by national coordinators for each project area, in consultation with IAEA technical officers. Most of the funding comes directly from RCA regional donor countries, with about one third supplied through the IAEA Technical Cooperation program. In 1986, following the Chernobyl accident, national coordinators and the IAEA staff recognized the value of establishing an RCA project aimed at strengthening regional radiation protection programs. The potential importance of RCA involvement in radiation protection is underscored by the fact that its member states comprise more than half of the world's population. The regional approach to addressing radiation protection issues allows member states to take advantage of regional resources to solve common regional problems. RCA provides the opportunity for specialists who may have few professional colleagues in their country to develop valuable contacts with regional radiation protection experts. In a very real way, specialists can network with their neighbours, often establishing bilateral programs outside of the RCA auspices. The current five year RCA Project to strengthen radiation protection infrastructure, with the IAEA designation - RAS/9/006, will be completed at the end of 1997. The project was developed to address five mayor areas of activity: Off-site emergency response; individual monitoring, internal and external; characterization of the physical, anatomical, physiological

Regional radiation standards for population of Chelyabinsk region

International Nuclear Information System (INIS)

Kravtsova, Eh.M.; Zajtseva, Yh.A.; Panteleev, V.V.; Gavrilov, A.P.; Kolotygina, N.V.; Pudovkina, L.V.; Kravtsova, O.S.

1996-01-01

Regional radiation regulations for population exposures in Chelyabinsk region are developed which are to play the role of standard limits. The priority goal of setting standard level is to consolidate the achieved radioecological balance on the contaminated territories and to establish a mechanism of control over the activities of the facility and over the use of lands in restriction zone by the population

First Asian regional congress on radiation protection

International Nuclear Information System (INIS)

Kumar, S.K.

1975-01-01

Due to the rapid progress in the development of nuclear energy and its applications in medicine, agriculture and industry, the potential danger to targe groups of population due to radiation hazards has increased. Thus, radiation protection has become an important aspects of industrial and public hygiene. The article reviews the deliberations of the First Asian Regional Congress on Radiation Protection which was held during 15-20 December 1974 at the Bhabha Atomic Research Centre. 190 papers were presented on the following broad subjects: (1) organization of radiation protection services on a countrywide scale and significant problems and experiences; (2) research and cooperation, mutual assistance, education and training; (3) personnel monitoring; (4) nuclear industry risks and benefits; (5) radiation protection legislation and (6) panel discussions and regional international cooperation in the field of radiation protection. (S.K.K.)

Synchrotron Radiation in eRHIC Interaction Region

CERN Document Server

Beebe-Wang, Joanne; Montag, Christoph; Rondeau, Daniel J; Surrow, Bernd

2005-01-01

The eRHIC currently under study at BNL consists of an electron storage ring added to the existing RHIC complex. The interaction region of this facility has to provide the required low-beta focusing while accommodating the synchrotron radiation generated by beam separation close to the interaction point. In the current design, the synchrotron radiation caused by 10GeV electrons bent by low-beta triplet magnets will be guided through the interaction region and dumped 5m downstream. However, it is unavoidable to stop a fraction of the photons at the septum where the electron and ion vacuum system are separated. In order to protect the septum and minimize the backward scattering of the synchrotron radiation, an absorber and collimation system will be employed. In this paper, we first present the overview of the current design of the eRHIC interaction region with special emphasis on the synchrotron radiation. Then the initial design of the absorber and collimation system, including their geometrical and physical p...

Extensive reduction of surface UV radiation since 1750 in world's populated regions

Directory of Open Access Journals (Sweden)

M. M. Kvalevåg

2009-10-01

Full Text Available Human activity influences a wide range of components that affect the surface UV radiation levels, among them ozone at high latitudes. We calculate the effect of human-induced changes in the surface erythemally weighted ultra-violet radiation (UV-E since 1750. We compare results from a radiative transfer model to surface UV-E radiation for year 2000 derived by satellite observations (from Total Ozone Mapping Spectroradiometer and to ground based measurements at 14 sites. The model correlates well with the observations; the correlation coefficients are 0.97 and 0.98 for satellite and ground based measurements, respectively. In addition to the effect of changes in ozone, we also investigate the effect of changes in SO₂, NO₂, the direct and indirect effects of aerosols, albedo changes and aviation-induced contrails and cirrus. The results show an increase of surface UV-E in polar regions, most strongly in the Southern Hemisphere. Furthermore, our study also shows an extensive surface UV-E reduction over most land areas; a reduction up to 20% since 1750 is found in some industrialized regions. This reduction in UV-E over the industrial period is particularly large in highly populated regions.

Radiation education by means of the measurement of natural environmental radiation in Tono region, Gifu prefecture

International Nuclear Information System (INIS)

Maruyama, Haruo; Yoshida, Yasuo; Uda, Tatsuhiko; Obayashi, Haruo

1999-01-01

The Tono region is placed in the south-east of Gifu prefecture. In this region, there is a plan of construction of the Research and Education Park. As the center facility of the park, the National Institute for Fusion Science (NIFS) has started their research activities. The Plasma Research Committee of Toki-city has been organized by the board of education of Toki-city for about 20 years. The committee is mainly composed of science teachers of elementary school, junior high school and high school in the area. The committee has measured continuously the natural environmental background radiations in cooperation with NIFS. Its activities started before constructing the NIFS laboratory buildings. Now, the new measuring points in Tajimi-city and Mizunami-city are added to the points in Toki-city area, therefore, some teachers join as the new members of the committee. In this conference, we present. (1) Plasma Research Committee of Toki-city; its history, organization and activities. (2) Obtained data of the natural environmental radiation in Toki-city. (3) Example lecture taken in natural radiation, its results and the farther issues. (author)

Regional radiation protection initiatives by Australia

International Nuclear Information System (INIS)

Grey, J.

1993-01-01

Australia both through the auspices of the IAEA and from Government Aid Grants has contributed to the improvement of radiation protection throughout the Asia/Pacific region. The assistance has been in the form of training and improvement to radiation protection infrastructures. The presentation describes the objectives, scope and diversity of the radiation protection infrastructure program and the benefits to the large number of persons included in the program. An outline of the current IAEA program is also discussed together with an explanation of how the program will assist national regulators in the education of radiation workers, in hazardous operations such as industrial radiography

Biological responses to current UV-B radiation in Arctic regions

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

2008-01-01

on high-arctic vegetation. They supplement previous investigations from the Arctic focussing on other variables like growth etc., which have reported no or minor plant responses to UV-B, and clearly indicates that UV-B radiation is an important factor affecting plant life at high-arctic Zackenberg......Depletion of the ozone layer and the consequent increase in solar ultraviolet-B radiation (UV-B) may impact living conditions for arctic plants significantly. In order to evaluate how the prevailing UV-B fluxes affect the heath ecosystem at Zackenberg (74°30'N, 20°30'W) and other high......-arctic regions, manipulation experiments with various set-ups have been performed. Activation of plant defence mechanisms by production of UV-B absorbing compounds was significant in ambient UV-B in comparison to a filter treatment reducing the UV-B radiation. Despite the UV-B screening response, ambient UV...

Regional and national radiation protection activities in Egypt

International Nuclear Information System (INIS)

Gomaa, M.A.M.

2008-01-01

Radiation protection activities in Egypt go back to 1957 where the Egyptian Atomic Energy Commission (EAEC) Law was issued. Radiation protection and civil defense department was one of EAEC eighth departments. Ionizing radiation law was issued in 1960 and its executive regulation in 1962. The main aim of the present work is to through some light on the current radiation protection activities in Egypt. This includes not only the role of governmental organizations but also to the non governmental organizations. Currently a new Nuclear Safety law is understudy. Regional activities such as holding the second all African IRPA regional radiation protection congress which was held in April 2007 and national training and workshops are held regularly through EAEA, AAEA and MERRCAC. (author)

Diagnostic radiation and its prognosis of pineal region tumor

International Nuclear Information System (INIS)

Momose, Toshimitsu; Aoki, Yukimasa; Akanuma, Atsuo; Machida, Tohru; Iio, Masahiro; Takakura, Kimitomo

1984-01-01

20 Gy of local irradiation was performed for the patients with pineal region tumor. We evaluated the tumor volume on X-CT in the pre-radiation and 20 Gy of post-radiation state. If tumor is sensitive enough to radiation therapy, we add 40 Gy of whole brain and 30 to 40 Gy of whole spine irradiation. If not, we transfer patients to neurosurgeons for the purpose of tumor ressection. We call this procedure ''Diagnostic Radiation.'' We proposed the concept of TRR (Tumor Regression Ratio) in order to evaluate our protocol more objctively. TRR is as follows: TRR (%) = [1-Total Tumor Volume (at each dose) / Total Tumor Volume (at o Gy)] x 100 (%) Total Tumor Volume(mm 3 ) = slice thickness(mm) x siguma HDA (mm 2 ) on each slice: where HDA is high density area on enhanced CT. Eleven patients were studied and TRR of each patients was calculated. The relations between TRR, tumor markers, CSF seeding and prognoiss was discussed. From our study, (1) TRR at 20Gy was important and might predict approximate prognosis of each cae case. A) TRR = 100 → very good B) TRR < 20 → poor C) 20 <= TRR < 100 → high possibility (2) Majority of TRR < 100 cases have turned out to be histologically in teratoma category. (3) Good correlation between the level of tumor markers and prognosis was observed. Cases with elevated level of AFP and/or HCG were radio- resistant and had poor prognosis. (4) Distant metastasis must also be kept in mind in the treatment of pineal region tumor. (author)

Risks for cancer induction by pion radiation in the peak- and plateau region

International Nuclear Information System (INIS)

Cottier, H.; Fritz-Niggli, H.; Froehlich, E.; Heinzell, F.; Nichel, C.; Rao, K.

In the foreground of an evaluation of the suitability of negative protons for cancer therapy there is, beside the analysis of pion effect on malignant cells, also the reaction of healthy tissue. The observation that neutrons at the lowest dose-rate can induce breast cancer and our own results after pion radiation in the peak-region necessitate a broadly planned, urgent investigation of these delayed damages. We will consider radiations at the plateau- and peak-region, the results of which should be of utmost interest for the comparison of neutron- and pion therapy. There are indications that the RBE of a high LET radiation is extremely large for the tumor induction. We will investigate especially the development of mammary cancers in variously aged mice with a low spontaneous tumor rate and C 3 H mice with a high cancer expectancy

Position sensitive regions in a generic radiation sensor based on single event upsets in dynamic RAMs

International Nuclear Information System (INIS)

Darambara, D.G.; Spyrou, N.M.

1997-01-01

Modern integrated circuits are highly complex systems and, as such, are susceptible to occasional failures. Semiconductor memory devices, particularly dynamic random access memories (dRAMs), are subject to random, transient single event upsets (SEUs) created by energetic ionizing radiation. These radiation-induced soft failures in the stored data of silicon based memory chips provide the foundation for a new, highly efficient, low cost generic radiation sensor. The susceptibility and the detection efficiency of a given dRAM device to SEUs is a complicated function of the circuit design and geometry, the operating conditions and the physics of the charge collection mechanisms involved. Typically, soft error rates measure the cumulative response of all sensitive regions of the memory by broad area chip exposure in ionizing radiation environments. However, this study shows that many regions of a dynamic memory are competing charge collection centres having different upset thresholds. The contribution to soft fails from discrete regions or individual circuit elements of the memory device is unambiguously separated. Hence the use of the dRAM as a position sensitive radiation detector, with high spatial resolution, is assessed and demonstrated. (orig.)

Radiation distribution sensor with optical fibers for high radiation fields

International Nuclear Information System (INIS)

Takada, Eiji; Kimura, Atsushi; Hosono, Yoneichi; Takahashi, Hiroyuki; Nakazawa, Masaharu

1999-01-01

Radiation distribution sensors with their feasibilities have been described in earlier works. However, due to large radiation induced transmission losses in optical fibers, especially in the visible wavelength region, it has been difficult to apply these techniques to high radiation fields. In this study, we proposed a new concept of optical fiber based radiation distribution measurements with near infrared (IR) emission. Near IR scintillators were attached to the ends of optical fibers, where the fibers were bundled and connected to an N-MOS line sensor or a cooled CCD camera. From the measurements of each area density, the radiation levels at the positions of the scintillators can be known. The linearity between the gamma dose rate at each scintillator and the registered counts has been examined. For correcting the radiation induced loss effects, we applied the Optical Time Domain Reflectometry technique to measure the loss distribution and from the results, a possibility for correction of the loss effect has been demonstrated. The applicable dose rate range was evaluated to be from 0.1 to 10 3 Gy/h. This system can be a promising tool as a flexible dose rate distribution monitor in radiation facilities like nuclear plants and accelerator facilities. (author)

Revisiting the `forbidden' region: AGN radiative feedback with radiation trapping

Science.gov (United States)

Ishibashi, W.; Fabian, A. C.; Ricci, C.; Celotti, A.

2018-06-01

Active galactic nucleus (AGN) feedback, driven by radiation pressure on dust, is an important mechanism for efficiently coupling the accreting black hole to the surrounding environment. Recent observations confirm that X-ray selected AGN samples respect the effective Eddington limit for dusty gas in the plane defined by the observed column density versus the Eddington ratio, the so-called NH - λ plane. A `forbidden' region occurs in this plane, where obscuring clouds cannot be long-lived, due to the action of radiation pressure on dust. Here we compute the effective Eddington limit by explicitly taking into account the trapping of reprocessed radiation (which has been neglected in previous works), and investigate its impact on the NH - λ plane. We show that the inclusion of radiation trapping leads to an enhanced forbidden region, such that even Compton-thick material can potentially be disrupted by sub-Eddington luminosities. We compare our model results to the most complete sample of local AGNs with measured X-ray properties, and find good agreement. Considering the anisotropic emission from the accretion disc, we also expect the development of dusty outflows along the polar axis, which may naturally account for the polar dust emission recently detected in several AGNs from mid-infrared observations. Radiative feedback thus appears to be the key mechanism regulating the obscuration properties of AGNs, and we discuss its physical implications in the context of co-evolution scenarios.

Nonlinear radiation generation processes in the auroral acceleration region

Directory of Open Access Journals (Sweden)

R. Pottelette

2017-11-01

Full Text Available It is known from laboratory plasma experiments that double layers (DLs radiate in the electromagnetic spectrum; but this is only known qualitatively. In these experiments, it was shown that the electron beam created on the high-potential side of a DL generates nonlinear structures which couple to electromagnetic waves and act as a sender antenna. In the Earth auroral region, observations performed by auroral spacecraft have shown that DLs occur naturally in the source region of intense radio emissions called auroral kilometric radiation (AKR. Very high time-, spatial-, and temporal-resolution measurements are needed in order to characterize waves and particle distributions in the vicinity of DLs, which are moving transient structures. We report observations from the FAST satellite of a localized large-amplitude parallel electric field (∼ 300 mV m−1 recorded at the edges of the auroral density cavity. In agreement with laboratory experiments, on the high-potential side of the DL, elementary radiation events are detected. They occur substantially above the local electron gyrofrequency and are associated with the presence of electron holes. The velocity of these nonlinear structures can be derived from the measurement of the Doppler-shifted AKR frequency spectrum above the electron gyrofrequency. The generated electron holes appear as the nonlinear evolution of electrostatic waves generated by the electron–electron two-stream instability because they propagate at about half the beam velocity. It is pointed out that, in the vicinity of a DL, the shape of the electron distribution gives rise to a significant power recorded in the left-hand polarized ordinary (LO mode.

Radiation-hard Silicon Photonics for Future High Energy Physics Experiments

CERN Document Server

AUTHOR|(CDS)2089774; Troska, Jan

Collisions of proton beams in the Large Hadron Collider at CERN produce very high radiation levels in the innermost parts of the particle detectors and enormous amounts of measurement data. Thousands of radiation-hard optical links based on directly-modulated laser diodes are thus installed in the particle detectors to transmit the measurement data to the processing electronics. The radiation levels in the innermost regions of future particle detectors will be much higher than they are now. Alternative solutions to laser-based radiation-hard optical links have to be found since the performance of laser diodes decreases beyond the operation margin of the system when irradiated to sufficiently high radiation levels. Silicon Photonics (SiPh) is currently being investigated as a promising alternative technology. First tests have indeed shown that SiPh Mach-Zehnder modulators (MZMs) are relatively insensitive to a high neutron fluence. However, they showed a strong degradation when exposed to ionizing radiation. ...

Delayed radiation necrosis in the optochiasmatic region

International Nuclear Information System (INIS)

Andoh, Takashi; Yokoyama, Kazutoshi; Kumagai, Morio

1984-01-01

Two cases with delayed radiation necrosis of the chiasmatic region following irradiation of the hypophysis for treatment of Cushing's disease were presented. Case 1 was a 36-year-old female who had reduction of visual acuity and bitemporal hemianopsia 2 years after 60 Co-irradiation therapy (total 8000 rads) for Cushing's disease. CT scans showed low density in the pituitary fossa and irregular contrast-enhanced suprasellar mass, and metrizamide CT cisternography revealed the pituitary fossa filled with contrast medium. From those findings, secondary empty sella syndrome was suspicious. Case 2 was a 35-year-old male who had progressive visual disturbance 3 years after 60 Co-irradiation therapy (total 9050 rads) for Cushing's disease. The right visual acuity was 0.05 and the left one was 0.1. Examination of visual field showed left homonymous hemianopsia. CT scans showed the contrast enhanced suprasellar mass extending to the right anterior thalamic region, and metrizamide CT cisternography detected secondary empty sella as same as that of Case 1. Authors reviewed and analyzed literatures of delayed radiation necrosis. The incidence of this condition was 4% to 9% and onset of the symptoms occured approximately 2 years after irradiation to hypophysis. Administration of steroid hormone and surgical treatment for the radiation necrosis involving the chiasmatic region were almost ineffective and also the prognosis of radionecrotic lesions involving the hypothalamus was very poor. Therefore, radiotherapy for hypophyseal region must be carried out by means of a rotation or arching technique in order to avoid this condition and further total dosage and its fractionation in radiation therapy should not exceed 6000 rads and 200 rads a day. (J.P.N.)

Radiation shielding for the Super Collider West Utility region

International Nuclear Information System (INIS)

Meinke, R.; Mokhov, N.; Orth, D.; Parker, B.; Plant, D.

1994-02-01

Shielding considerations in the 20 x 20-TeV Superconducting Super Collider are strongly correlated with detailed machine specifics in the various accelerator sections. The West Utility, the most complex area of the Collider, concentrates all the major accelerator subsystems in a single area. The beam loss rate and associated radiation levels in this region are anticipated to be quite high, and massive radiation shielding is therefore required to protect personnel, Collider components, and the environment. The challenging task of simultaneously optimizing accelerator design and radiation shielding, both of which are strongly influenced by subsystem design details, requires the integration of several complex simulation codes. To this end we have performed exhaustive hadronic shower simulations with the MARS12 program; detailed accelerator lattice and optics optimization via the SYNCH, MAD, and MAGIC codes; and extensive 3-D configuration modeling of the accelerator tunnel and subsystems geometries. Our technique and the non-trivial results from such a combined approach are presented here. An integrated procedure is found invaluable in developing cost-effective radiation shielding solutions

Escape of ionizing radiation from star-forming regions in Young galaxies

DEFF Research Database (Denmark)

Razoumov, A; Sommer-Larsen, Jesper

2006-01-01

Galaxies: Formation, Galaxies: Intergalactic Medium, ISM: H II Regions, Radiative Transfer Udgivelsesdato: Nov. 10......Galaxies: Formation, Galaxies: Intergalactic Medium, ISM: H II Regions, Radiative Transfer Udgivelsesdato: Nov. 10...

Land radiative management as contributor to regional-scale climate adaptation and mitigation

Science.gov (United States)

Seneviratne, Sonia I.; Phipps, Steven J.; Pitman, Andrew J.; Hirsch, Annette L.; Davin, Edouard L.; Donat, Markus G.; Hirschi, Martin; Lenton, Andrew; Wilhelm, Micah; Kravitz, Ben

2018-02-01

Greenhouse gas emissions urgently need to be reduced. Even with a step up in mitigation, the goal of limiting global temperature rise to well below 2 °C remains challenging. Consequences of missing these goals are substantial, especially on regional scales. Because progress in the reduction of carbon dioxide emissions has been slow, climate engineering schemes are increasingly being discussed. But global schemes remain controversial and have important shortcomings. A reduction of global mean temperature through global-scale management of solar radiation could lead to strong regional disparities and affect rainfall patterns. On the other hand, active management of land radiative effects on a regional scale represents an alternative option of climate engineering that has been little discussed. Regional land radiative management could help to counteract warming, in particular hot extremes in densely populated and important agricultural regions. Regional land radiative management also raises some ethical issues, and its efficacy would be limited in time and space, depending on crop growing periods and constraints on agricultural management. But through its more regional focus and reliance on tested techniques, regional land radiative management avoids some of the main shortcomings associated with global radiation management. We argue that albedo-related climate benefits of land management should be considered more prominently when assessing regional-scale climate adaptation and mitigation as well as ecosystem services.

Argentina, regional training center on radiation protection for Latin America

International Nuclear Information System (INIS)

Terrado, Carlos A.; Menossi, Carlos A.

2008-01-01

Argentina has an extensive background in education and training on Radiation Protection. Since the beginning of the nuclear activity in the country, prominence was given to the aspects related to radiation protection and training of the personnel involved in the use of ionizing radiation. These educative activities have been delivered for more than 50 years, having accumulated an important experience in the field. The Nuclear Regulatory Authority has the statutory obligation to address, among other matters, the control of the aspects of nuclear safety and radiation protection on the whole country, to protect the people of the harmful effects of ionizing radiation resulting from the nuclear activities. This includes the responsibility to develop and enforce the regulations, standards and other requirements, particularly, establishing the requests and promoting activities regarding education and training on radiation protection. Argentina, currently through the Nuclear Regulatory Authority, has performed postgraduate courses on radiation protection and nuclear safety at inter regional and regional level for 28 years without interruption. This important experience has been valued and exploited to form a Regional Center on Education and Training for Latin America and the Caribbean, sponsored by the International Atomic Energy Agency. The Regional Center that in fact has been running in Argentina, trained 404 foreign participants and 327 local participants since 1980, totalizing 731 graduates from our annual post graduate courses. Our commitment is that all the effort made in education and training on radiation protection and nuclear safety contributes to a better use of the benefits of nuclear development. Since 2001 the International Atomic Energy Agency raised the need to develop plans and establish agreements to ensure a long-term sustainability of the education and training programs, allowing a better use of the resources in this area. In order to achieve this goal

Observation of high-power coherent synchrotron radiation in the THz region from the JAEA energy recovery linac

International Nuclear Information System (INIS)

Takahashi, Toshiharu; Okuda, Shuichi; Minehara, Eisuke J.; Hajima, Ryoichi; Sawamura, Masaru; Nagai, Ryoji; Kikuzawa, Nobihiro; Iijima, Hokuto; Nishitani, Tomohiro; Nishimori, Nobuyuki

2007-01-01

The energy recovery linac (ERL) is able to generate high-power coherent synchrotron radiation (CSR) in the terahertz and the millimeter-wave regions, because it produces shorter bunches than usual storage rings and a higher current than conventional linacs. The spectrum of CSR has been measured at the JAEA-ERL in the wavenumber range from 0.5 to 15 cm -1 . The detected power was 2x10 -4 W/cm -1 at 2.5 cm -1 for the average beam current of 17.7 μA. When the infrared FEL was operated with the undulator in the ERL, the CSR spectrum was shifted to the longer wavelengths because of the energy broadening of the electron beam. (author)

Radiation processing and high-dose dosimetry at ANSTO

International Nuclear Information System (INIS)

Gant, G.J.; Saunders, M.; Banos, C.; Mo, L.; Davies, J.; Evans, O.

2001-01-01

The Radiation Technology group at ANSTO is part of the Physics Division and provides services and advice in the areas of gamma irradiation and high-dose dosimetry. ANSTO's irradiation facilities are designed for maximum dose uniformity and provide a precision irradiation service unique in Australia. Radiation Technology makes and sells reference and transfer standard dosimeters which are purchased by users and suppliers of commercial irradiation services in Australia and the Asia-Pacific region. A calibration service is also provided for dosimeters purchased from other suppliers

The radiation protection problems of high altitude and space flight

International Nuclear Information System (INIS)

Fry, R.J.M.

1993-01-01

This paper considers the radiation environment in aircraft at high altitudes and spacecraft in low earth orbit and in deep space and the factors that influence the dose equivalents. Altitude, latitude and solar cycle are the major influences for flights below the radiation belts. In deep space, solar cycle and the occurrence of solar particle events are the factors of influence. The major radiation effects of concern are cancer and infertility in males. In high altitude aircraft the radiation consists mainly of protons and neutrons, with neutrons contributing about half the equivalent dose. The average dose rate at altitudes of transcontinental flights that approach the polar regions are greater by a factor of about 2.5 than on routes at low latitudes. Current estimates of does to air crews suggest they are well within the ICRP (1990) recommended dose limits for radiation workers

Aerosol Radiative Impact on the Middle East Regional Climate and the Red Sea

KAUST Repository

Osipov, Sergey

2017-01-01

The climate in the Middle East is complex and remains poorly understood. Due to the vast Arabian Desert, it is very sensitive to radiative forcing. Mineral dust is the dominant aerosol in this region. High background dust loading and frequent dust

Modeling of transient ionizing radiation effects in bipolar devices at high dose-rates

International Nuclear Information System (INIS)

FJELDLY, T.A.; DENG, Y.; SHUR, M.S.; HJALMARSON, HAROLD P.; MUYSHONDT, ARNOLDO

2000-01-01

To optimally design circuits for operation at high intensities of ionizing radiation, and to accurately predict their a behavior under radiation, precise device models are needed that include both stationary and dynamic effects of such radiation. Depending on the type and intensity of the ionizing radiation, different degradation mechanisms, such as photoelectric effect, total dose effect, or single even upset might be dominant. In this paper, the authors consider the photoelectric effect associated with the generation of electron-hole pairs in the semiconductor. The effects of low radiation intensity on p-II diodes and bipolar junction transistors (BJTs) were described by low-injection theory in the classical paper by Wirth and Rogers. However, in BJTs compatible with modem integrated circuit technology, high-resistivity regions are often used to enhance device performance, either as a substrate or as an epitaxial layer such as the low-doped n-type collector region of the device. Using low-injection theory, the transient response of epitaxial BJTs was discussed by Florian et al., who mainly concentrated on the effects of the Hi-Lo (high doping - low doping) epilayer/substrate junction of the collector, and on geometrical effects of realistic devices. For devices with highly resistive regions, the assumption of low-level injection is often inappropriate, even at moderate radiation intensities, and a more complete theory for high-injection levels was needed. In the dynamic photocurrent model by Enlow and Alexander. p-n junctions exposed to high-intensity radiation were considered. In their work, the variation of the minority carrier lifetime with excess carrier density, and the effects of the ohmic electric field in the quasi-neutral (q-n) regions were included in a simplified manner. Later, Wunsch and Axness presented a more comprehensive model for the transient radiation response of p-n and p-i-n diode geometries. A stationary model for high-level injection in p

Application of radiation processing in Asia and the pacific region: focus on Malaysia

International Nuclear Information System (INIS)

Khairul Zaman, H.J.; Mohd Dahlan

1995-01-01

Applications of radiation processing in Malaysia and other developing countries in Asia and the Pacific region is increasing as the countries move toward industrialisation. At present, there are more than 85 gamma facilities and 334 electron accelerators in Asia and the Pacific region which are mainly in Japan, Rep. of Korea and China. The main applications which are in the interest of the region are radiation sterilisation of medical products; radiation crosslinking of wire and cable, heat shrinkable film and tube, and foam; radiation euring of surface coatings, printing inks and adhesive; radiation vulcanisation of natural rubber latex; radiation processing of agro-industrial waste; radiation treatment of sewage sludge and municipal waste; food irradiation; tissue grafts and radiation synthesis of bioactive materials. (author)

Application of radiation processing in Asia and the Pacific region: focus on Malaysia

International Nuclear Information System (INIS)

Dahlan, K.Z.H.M.

1995-01-01

Applications of radiation processing in Malaysia and other developing countries in Asia and the Pacific region is increasing as the countries move toward industrialisation. At present, there are more than 85 gamma facilities and 334 electron accelerators in Asia and the Pacific region which are mainly in Japan, Rep. of Korea and China. The main applications which are in the interest of the region are radiation sterilisation of medical products; radiation crosslinking of wire and cable, heat shrinkable film and tube, and foam; radiation curing of surface coatings, printing inks and adhesive; radiation vulcanisation of natural rubber latex; radiation processing of agro-industrial waste; radiation treatment of sewage sludge and municipal waste; food irradiation; tissue grafts and radiation synthesis of bioactive materials. (author)

Monitoring of radiation situation in the territory of the Voronezh region

Directory of Open Access Journals (Sweden)

Yu. I. Stepkin

2017-01-01

Full Text Available The purpose of the study was to assess the doses of personnel and the population at the expense of all the main activities and sources of radiation in the territory of the Voronezh region. The data of the forms of state statistical supervision No. 1-DOZ “Information on the doses of personnel from persons under normal use of technogenic sources of ionizing radiation”, No. 3-DOZ “Information on radiation doses of patients during X-ray radiology studies”, No. 4-DOZ “Information on radiation doses of the population due to natural and technogenically altered background” for 2010-2016 and the radiation and hygienic passport of the territory of the Voronezh Region. Based on the results of monitoring the radiation situation, the situation associated with the impact of ionizing radiation sources in the Voronezh Region has been characterized as safe for the past 7 years. The average annual effective dose per 1 inhabitant due to all ionizing radiation remains stable with a slight upward trend and lies in the range from 2.925 (2010 to 3.399 mSv (2016. In the structure of the collective dose of the population of the Voronezh region, the dose from natural sources is 83.65%, from medical sources – 16.06%, from technogenically changed background radiation, including global fallout and accident at the Chernobyl nuclear power plant – 0.18%, from the activities of enterprises using Sources of ionizing radiation – 0.11%. The average annual effective dose of natural exposure to humans varies from 0.660 to 0.704 mSv / year, natural radiation from radon from 0.832 to 1.465 mSv / year. The average effective dose from medical research for the procedure for the study period was 0.27-0.40 mSv and tends to decrease due to the introduction of modern low-dose medical diagnostic equipment. On the territory of the Voronezh region, there were no population groups with an effective radiation dose exceeding 5 mSv / year. Gamma-background in the region in 2010

The mouse small eye mutant, Del(2)Sey3H, which deletes the putative tumor suppressor region of the radiation-induced acute myeloid leukemia is susceptible to radiation

International Nuclear Information System (INIS)

Nitta, Yumiko; Yoshida, Kazuko; Tanaka, Kimio; Peters, Jo; Cattanach, Bruce M.

2003-01-01

Radiation-induced murine acute myeloid leukemia (AML) is characterized by the chromosome 2 deletions. Standing on the hypothesis that an AML suppressor gene would locate on the chromosome 2, a deletion-wide screen was performed on radiation-induced AMLs by the fluorescence in situ hybridization (FISH) method. The hemizugous deletion of the D2Mit15, a marker DNA at the 49.0cM region from the centromere, associated with the AMLs in 97 out of the 105 cases (92.4%). As the deletion region was close to the region of human WAGR syndrome (MIM194072), the mouse small eye mutants could be the animal model for radiation-induced AMLs. The mutant, Del(2)Sey3H (Sey3H) was found to delete around the 49.0cM region by the allelic loss mapping. The Sey3H showed high susceptibility to radiation to develop tumors including the myeloid leukemia with shorter latency. These finding support the existence of a putative tumor suppressor gene responsible for the radiation-leukemogenesis near the D2Mit15 region. (author)

Biological responses to current UV-B radiation in Arctic regions

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

2008-01-01

Depletion of the ozone layer and the consequent increase in solar ultraviolet-B radiation (UV-B) may impact living conditions for arctic plants significantly. In order to evaluate how the prevailing UV-B fluxes affect the heath ecosystem at Zackenberg (74°30'N, 20°30'W) and other high......-arctic regions, manipulation experiments with various set-ups have been performed. Activation of plant defence mechanisms by production of UV-B absorbing compounds was significant in ambient UV-B in comparison to a filter treatment reducing the UV-B radiation. Despite the UV-B screening response, ambient UV...... (mycorrhiza) or in the biomass of microbes in the soil of the root zone. However, the composition of the soil microbial community was different in the soils under ambient and reduced UV radiation after three treatment years. These results provide new insight into the negative impact of current UV-B fluxes...

Stage III Melanoma in the Axilla: Patterns of Regional Recurrence After Surgery With and Without Adjuvant Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Pinkham, Mark B., E-mail: mark.pinkham@health.qld.gov.au [Department of Radiation Oncology, Princess Alexandra Hospital, Brisbane (Australia); University of Queensland, Brisbane (Australia); Foote, Matthew C. [Department of Radiation Oncology, Princess Alexandra Hospital, Brisbane (Australia); Queensland Melanoma Project, Princess Alexandra Hospital, Brisbane (Australia); Diamantina Institute, Brisbane (Australia); University of Queensland, Brisbane (Australia); Burmeister, Elizabeth [Nursing Practice Development Unit, Princess Alexandra Hospital, Brisbane (Australia); Research Centre for Clinical and Community Practice, Griffith University, Brisbane (Australia); Thomas, Janine [Queensland Melanoma Project, Princess Alexandra Hospital, Brisbane (Australia); Meakin, Janelle [Clinical Trials Research Unit, Princess Alexandra Hospital, Brisbane (Australia); Smithers, B. Mark [Queensland Melanoma Project, Princess Alexandra Hospital, Brisbane (Australia); University of Queensland, Brisbane (Australia); Burmeister, Bryan H. [Department of Radiation Oncology, Princess Alexandra Hospital, Brisbane (Australia); Queensland Melanoma Project, Princess Alexandra Hospital, Brisbane (Australia); University of Queensland, Brisbane (Australia)

2013-07-15

Purpose: To describe the anatomic distribution of regionally recurrent disease in patients with stage III melanoma in the axilla after curative-intent surgery with and without adjuvant radiation therapy. Methods and Materials: A single-institution, retrospective analysis of a prospective database of 277 patients undergoing curative-intent treatment for stage III melanoma in the axilla between 1992 and 2012 was completed. For patients who received radiation therapy and those who did not, patterns of regional recurrence were analyzed, and univariate analyses were performed to assess for potential factors associated with location of recurrence. Results: There were 121 patients who received adjuvant radiation therapy because their clinicopathologic features conferred a greater risk of regional recurrence. There were 156 patients who received no radiation therapy. The overall axillary control rate was 87%. There were 37 patients with regional recurrence; 17 patients had received adjuvant radiation therapy (14%), and 20 patients (13%) had not. The likelihood of in-field nodal recurrence was significantly less in the adjuvant radiation therapy group (P=.01) and significantly greater in sites adjacent to the axilla (P=.02). Patients with high-risk clinicopathologic features who did not receive adjuvant radiation therapy also tended to experience in-field failure rather than adjacent-field failure. Conclusions: Patients who received adjuvant radiation therapy were more likely to experience recurrence in the adjacent-field regions rather than in the in-field regions. This may not simply reflect higher-risk pathology. Using this data, it may be possible to improve outcomes by reducing the number of adjacent-field recurrences after adjuvant radiation therapy.

Stage III Melanoma in the Axilla: Patterns of Regional Recurrence After Surgery With and Without Adjuvant Radiation Therapy

International Nuclear Information System (INIS)

Pinkham, Mark B.; Foote, Matthew C.; Burmeister, Elizabeth; Thomas, Janine; Meakin, Janelle; Smithers, B. Mark; Burmeister, Bryan H.

2013-01-01

Purpose: To describe the anatomic distribution of regionally recurrent disease in patients with stage III melanoma in the axilla after curative-intent surgery with and without adjuvant radiation therapy. Methods and Materials: A single-institution, retrospective analysis of a prospective database of 277 patients undergoing curative-intent treatment for stage III melanoma in the axilla between 1992 and 2012 was completed. For patients who received radiation therapy and those who did not, patterns of regional recurrence were analyzed, and univariate analyses were performed to assess for potential factors associated with location of recurrence. Results: There were 121 patients who received adjuvant radiation therapy because their clinicopathologic features conferred a greater risk of regional recurrence. There were 156 patients who received no radiation therapy. The overall axillary control rate was 87%. There were 37 patients with regional recurrence; 17 patients had received adjuvant radiation therapy (14%), and 20 patients (13%) had not. The likelihood of in-field nodal recurrence was significantly less in the adjuvant radiation therapy group (P=.01) and significantly greater in sites adjacent to the axilla (P=.02). Patients with high-risk clinicopathologic features who did not receive adjuvant radiation therapy also tended to experience in-field failure rather than adjacent-field failure. Conclusions: Patients who received adjuvant radiation therapy were more likely to experience recurrence in the adjacent-field regions rather than in the in-field regions. This may not simply reflect higher-risk pathology. Using this data, it may be possible to improve outcomes by reducing the number of adjacent-field recurrences after adjuvant radiation therapy

Aerosol radiative effects over BIMSTEC regions

Science.gov (United States)

Kumar, Sumit; Kar, S. C.; Mupparthy, Raghavendra S.

Aerosols can have variety of shapes, composition, sizes and other properties that influence their optical characteristics and thus the radiative impact. The visible impact of aerosol is the formation of haze, a layer of particles from vehicular, industrial emissions and biomass burning. The characterization of these fine particles is important for regulators and researchers because of their potential impact on human health, their ability to travel thousands of kilometers crossing international borders, and their influence on climate forcing and global warming. The Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) with Member Countries Bangladesh, Bhutan, India, Myanmar, Nepal, Sri Lanka and Thailand has emerged as an important regional group for technical and economic Cooperation. Continuing the quest for a deeper understanding of BIMSTEC countries weather and climate, in this paper we focused on aerosols and their direct radiative effects. Because of various contrasts like geophysical, agricultural practices, heterogeneous land/ocean surface, population etc these regions present an excellent natural laboratory for studying aerosol-meteorology interactions in tropical to sub-tropical environments. We exploited data available on multiple platforms (such as MISR, MODIS etc) and models (OPAC, SBDART etc) to compute the results. Ten regions were selected with different surface characteristics, also having considerable differences in the long-term trends and seasonal distribution of aerosols. In a preliminary analysis pertaining to pre-monsoon (March-April-May) of 2013, AOD _{555nm} is found to be maximum over Bangladesh (>0.52) and minimum over Bhutan (0.22), whereas other regions have intermediate values. Concurrent to these variability of AOD we found a strong reduction in incoming flux at surface of all the regions (> -25 Wm (-2) ), except Bhutan and Sri Lanka (< -18Wm (-2) ). The top of the atmosphere (TOA) forcing values are

10. Latin American Regional Congress IRPA Protection and Radiation Safety

International Nuclear Information System (INIS)

2015-01-01

The 10.Latin American Regional Congress IRPA Protection and Radiation Safety was organized by the Radioprotection Argentine Society, in Buenos Aires, between the april 12 and 17, 2015. In this event, were presented almost 400 papers about these subjects: radiation protection in medicine and industry; radiological and nuclear emergencies; NORM (Natural Occurring Radioactive Materials); reactors; radiation dosimetry; radiotherapy; non-ionizing radiations; policies and communications; etc.

Characterization of radiation within the optical region

Energy Technology Data Exchange (ETDEWEB)

Albrecht, H [Stuttgart Univ. (TH) (Germany, F.R.). Inst. fuer Physikalische Elektronik

1977-04-01

The notions which are used for the characterization of radiation within the optical region of the spectrum (quantities, units) and their temporal and geometric relations have been arranged synoptically. Quantities of the international system (SI-System) are emphasized.

Lung deformations and radiation-induced regional lung collapse in patients treated with stereotactic body radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Diot, Quentin, E-mail: quentin.diot@ucdenver.edu; Kavanagh, Brian; Vinogradskiy, Yevgeniy; Gaspar, Laurie; Miften, Moyed [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States); Garg, Kavita [Department of Radiology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)

2015-11-15

Purpose: To differentiate radiation-induced fibrosis from regional lung collapse outside of the high dose region in patients treated with stereotactic body radiation therapy (SBRT) for lung tumors. Methods: Lung deformation maps were computed from pre-treatment and post-treatment computed tomography (CT) scans using a point-to-point translation method. Fifty anatomical landmarks inside the lung (vessel or airway branches) were matched on planning and follow-up scans for the computation process. Two methods using the deformation maps were developed to differentiate regional lung collapse from fibrosis: vector field and Jacobian methods. A total of 40 planning and follow-ups CT scans were analyzed for 20 lung SBRT patients. Results: Regional lung collapse was detected in 15 patients (75%) using the vector field method, in ten patients (50%) using the Jacobian method, and in 12 patients (60%) by radiologists. In terms of sensitivity and specificity the Jacobian method performed better. Only weak correlations were observed between the dose to the proximal airways and the occurrence of regional lung collapse. Conclusions: The authors presented and evaluated two novel methods using anatomical lung deformations to investigate lung collapse and fibrosis caused by SBRT treatment. Differentiation of these distinct physiological mechanisms beyond what is usually labeled “fibrosis” is necessary for accurate modeling of lung SBRT-induced injuries. With the help of better models, it becomes possible to expand the therapeutic benefits of SBRT to a larger population of lung patients with large or centrally located tumors that were previously considered ineligible.

Dosimetry of high energy radiation

CERN Document Server

Sahare, P D

2018-01-01

High energy radiation is hazardous to living beings and a threat to mankind. The correct estimation of the high energy radiation is a must and a single technique may not be very successful. The process of estimating the dose (the absorbed energy that could cause damages) is called dosimetry. This book covers the basic technical knowledge in the field of radiation dosimetry. It also makes readers aware of the dangers and hazards of high energy radiation.

The HZE radiation problem. [highly-charged energetic galactic cosmic rays

Science.gov (United States)

Schimmerling, Walter

1990-01-01

Radiation-exposure limits have yet to be established for missions envisioned in the framework of the Space Exploration Initiative. The radiation threat outside the earth's magnetosphere encompasses protons from solar particle events and the highly charged energetic particles constituting galactic cosmic rays; radiation biology entails careful consideration of the extremely nonuniform patterns of such particles' energy deposition. The ability to project such biological consequences of exposure to energetic particles as carcinogenicity currently involves great uncertainties from: (1) different regions of space; (2) the effects of spacecraft structures; and (3) the dose-effect relationships of single traversals of energetic particles.

Experimental study of coherent radiation in the millimeter-wave region at the KURRI-LINAC

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Toshiharu [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

1996-07-01

Coherent radiation, i.e., synchrotron radiation, transition radiation, Cherenkov radiation, or Smith-Purcell radiation emitted by short bunches of electrons has been observed in the millimeter-wave region. Properties of coherent radiation are characterized by the coherence effect and the relativistic one. The intensity of coherent radiation is enormously enhanced by several orders of magnitude in comparison with the incoherent radiation and the flux of radiation concentrates around the direction of the electron beam. Coherent radiation is useful as the intense light source in the millimeter-wave region. (author)

Observational characteristics of cloud radiative effects over three arid regions in the Northern Hemisphere

Science.gov (United States)

Li, Jiandong; Wang, Tianhe; Habib, Ammara

2017-08-01

Cloud-radiation processes play an important role in regional energy budgets and surface temperature changes over arid regions. Cloud radiative effects (CREs) are used to quantitatively measure the aforementioned climatic role. This study investigates the characteristics of CREs and their temporal variations over three arid regions in central Asia (CA), East Asia (EA), and North America (NA), based on recent satellite datasets. Our results show that the annual mean shortwave (SW) and net CREs (SWCRE and NCRE) over the three arid regions are weaker than those in the same latitudinal zone of the Northern Hemisphere. In most cold months (November-March), the longwave (LW) CRE is stronger than the SWCRE over the three arid regions, leading to a positive NCRE and radiative warming in the regional atmosphere-land surface system. The cold-season mean NCRE at the top of the atmosphere (TOA) averaged over EA is 4.1 W m-2, with a positive NCRE from November to March, and the intensity and duration of the positive NCRE is larger than that over CA and NA. The CREs over the arid regions of EA exhibit remarkable annual cycles due to the influence of the monsoon in the south. The TOA LWCRE over arid regions is closely related to the high-cloud fraction, and the SWCRE relates well to the total cloud fraction. In addition, the relationship between the SWCRE and the low-cloud fraction is good over NA because of the considerable occurrence of low cloud. Further results show that the interannual variation of TOA CREs is small over the arid regions of CA and EA, but their surface LWCREs show certain decreasing trends that correspond well to their decreasing total cloud fraction. It is suggested that combined studies of more observational cloud properties and meteorological elements are needed for indepth understanding of cloud-radiation processes over arid regions of the Northern Hemisphere.

Skin aspergillosis induced in the region of radiation ulcer

International Nuclear Information System (INIS)

Niimura, Yumiko; Nakauchi, Yohichi; Ushijima, Tsugako

1980-01-01

A case of skin aspergillosis in the region of radiation ulcer which was caused by Aspergillus fumigatus was reported. The patient was a 51 year-old man. This fungal infection was probably induced by a local factor, that is, chronic radiation ulcer. Histological findings suggested that Aspergillus fumigatus which increased saprophytically at the beginning possessed parasitic nature gradually, invaded into connective tissues in the deep layer of true skin, and made radiation ulcer more intractable. (Tsunoda, M.)

The wireless sensor network monitoring system for regional environmental nuclear radiation

International Nuclear Information System (INIS)

Liu Chong; Liu Dao; Wang Yaojun; Xie Yuxi; Song Lingling

2012-01-01

The wireless sensor network (WSN) technology has been utilized to design a new regional environmental radiation monitoring system based on the wireless sensor networks to meet the special requirements of monitoring the nuclear radiation in certain regions, and realize the wireless transmission of measurement data, information processing and integrated measurement of the nuclear radiation and the corresponding environmental parameters in real time. The system can be applied to the wireless monitoring of nuclear radiation dose in the nuclear radiation environment. The measured data and the distribution of radiation dose can be vividly displayed on the graphical interface in the host computer. The system has functioned with the wireless transmission and control, the data storage, the historical data inquiry, the node remote control. The experimental results show that the system has the advantages of low power consumption, stable performance, network flexibility, range of measurement and so on. (authors)

Observation of parametric X-ray radiation in an anomalous diffraction region

Energy Technology Data Exchange (ETDEWEB)

Alexeyev, V.I., E-mail: vial@x4u.lebedev.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation); Eliseyev, A.N., E-mail: elisseev@pluton.lpi.troitsk.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation); Irribarra, E., E-mail: esteban.irribarra@epn.edu.ec [Escuela Politécnica Nacional, Ladrón de Guevara E11-253, Quito (Ecuador); Kishin, I.A., E-mail: ivan.kishin@mail.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation); Kubankin, A.S., E-mail: kubankin@bsu.edu.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation); Nazhmudinov, R.M., E-mail: fizeg@bk.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation)

2016-08-19

A new possibility to expand the energy region of diffraction processes based on the interaction of relativistic charged particles with crystalline structures is presented. Diffracted photons related to parametric X-ray radiation produced by relativistic electrons are detected below the low energy threshold for the X-ray diffraction mechanism in crystalline structures for the first time. The measurements were performed during the interaction of 7 MeV electrons with a textured polycrystalline tungsten foil and a highly oriented pyrolytic graphite crystal. The experiment results are in good agreement with a developed model based on the PXR kinematical theory. The developed experimental approach can be applied to separate the contributions of real and virtual photons to the total diffracted radiation generated during the interaction of relativistic charged particles with crystalline targets. - Highlights: • Parametric X-ray radiation below the low energy threshold for diffraction of free X-rays. • Experimental separation of the contributions from different radiation mechanisms. • PXR from relativistic electrons in mosaic crystals and textured polycrystlas.

High-let radiation carcinogenesis

International Nuclear Information System (INIS)

Fry, R.J.M.; Powers-Risius, P.; Alpen, E.L.; Ainsworth, E.J.; Ullrich, R.L.

1982-01-01

Recent results for neutron radiation-induced tumors are presented to illustrate the complexities of the dose-response curves for high-LET radiation. It is suggested that in order to derive an appropriate model for dose-response curves for the induction of tumors by high-LET radiation it is necessary to take into account dose distribution, cell killing and the susceptibility of the tissue under study. Preliminary results for the induction of Harderian gland tumors in mice exposed to various heavy ion beams are presented. The results suggest that the effectiveness of the heavy ion beams increases with increasing LET. The slopes of the dose-response curves for the different high-LET radiations decrease between 20 and 40 rads and therefore comparisons of the relative effectiveness should be made from data obtained at doses below about 20 to 30 rads

Environmental Radiation Surveillance Results from over the Last Decade of Operational Experience at the Regional Radiation Monitoring Stations(RRMS)

Energy Technology Data Exchange (ETDEWEB)

Lee, Hae Young [Daegu Regional Radiation Monitoring Station, Daegu (Korea, Republic of); Yoo, Dong Han [Ulsan Regional Radiation Monitoring Station, Ulsan (Korea, Republic of); Lee, Sang Hoon [Kyungpook National University, Daegu (Korea, Republic of)

2015-10-15

The objectives of the current program are to monitor environmental radiation/radioactivity level in Korea and to provide the base-line data on environmental radiation/radioactivity which will be useful in the case of radiological emergency situations. This program plays an important role in the view of protecting the public health against the potential hazards of radiation and maintaining a clean environment. This paper describes an introduction to the Regional Radiation Monitoring Stations (RRMS), and also presents some results of recent years (2001-2014). The environmental radiation surveillance results of years 2001-2014 have been described. It indicates normal levels of radiation in the past years. These kinds of studies are very important in providing references in understanding the environmental radioactivity level in a particular region.

Radiation ecological monitoring in NPP region

International Nuclear Information System (INIS)

Egorov, Yu.A.; Kazakov, S.V.

1985-01-01

The known principle of sanitary-hygienic regulation of NPP radiation effect on man and environment is analyzed. An ecological approach is required to optimize NPP relations with the environment and to regulate radioactivity of the NPP - environment system. The ecological approach envisages the development of standards of permissible concentrations of radioactive and chemical substances (as well as heat) in natural environment, taking into account their synergism, corresponding to ecologically permissible response reactions of biota to their effect. The ecological approach also comprises the sanitary-hygienic principle of radiation protection of man. Attention is paid to ecological monitoring in NPP region, comprising consideration of factors, affecting the environment, evaluation of the actual state of the environment, prediction of the environmental state, evaluation of the expected environmental state

A radiation condition in some regions with more pronounced effect of the Chernobyl accident

International Nuclear Information System (INIS)

Ivanov, I.V.; Ivanov, I.M.

1993-01-01

The radioecological condition of the Devin region situated in the Rodopes mountain (Bulgaria) has been investigated for the period October 1992 - March 1993. It is believed that the Rodopes were more significantly affected by the Chernobyl accident in comparison with other regions of Bulgaria. Some regions near Kozloduy NPP have been chosen for comparing, for which there are more detailed investigations of the anthropogenic radiation effects. Analysis of the background radiation is made, specific soil and water samples are tested. The alterations in the radiation conditions of the Devin region are analysed. Some conclusions and predictions for the trends in further alterations of the background radiation are made. As a result a draft regional program for environment protection reclamation is prepared. (V.K.)

Ecological radiation monotoring in NPP region, aims and tasks

International Nuclear Information System (INIS)

Egorov, Yu.A.

1986-01-01

Aims and tasks of ecological radiation monitoring in the NPP region are discussed. The aims of monitoring are: to determine possible sequences of NPP radioactive release effects on ecosystems, taking place on the background of chemical and thermal pollution to develop standard of radiation effect on ecosystems; the aims includes also obtaining of information for forecasting and evaluating long-term radiation effects, establishment of factors characterizing the ecosystem state, establishment of a combined effect of radioactive wastes with chemical and thermal ones. Finally, the aim of monitoring consists in providing the natural object conservation in the NPP region under optimal operation conditions. Thus it is necessary to solve the following problems: to observe systematically release, transport and transformation, when transporting radioactive and chemical contaminants in terrestial and aquatic biocenoses, as well as injection and transport in them of waste heat; to observe systematically the natural physico-chemical, chemico-biological processes affecting the injection and transport of contaminants in ecosystem components; to observe systematically the natural and, probably, antropogenic processes; to carry out systematically observations of the ecosystem state in the NPP region and eco-systems-monitors

High power beam profile monitor with optical transition radiation

International Nuclear Information System (INIS)

Denard, J.C.; Piot, P.; Capek, K.; Feldl, E.

1997-01-01

A simple monitor has been built to measure the profile of the high power beam (800 kW) delivered by the CEBAF accelerator at Jefferson Lab. The monitor uses the optical part of the forward transition radiation emitted from a thin carbon foil. The small beam size to be measured, about 100 μm, is challenging not only for the power density involved but also for the resolution the instrument must achieve. An important part of the beam instrumentation community believes the radiation being emitted into a cone of characteristic angle 1/γ is originated from a region of transverse dimension roughly λγ; thus the apparent size of the source of transition radiation would become very large for highly relativistic particles. This monitor measures 100 μm beam sizes that are much smaller than the 3.2 mm λγ limit; it confirms the statement of Rule and Fiorito that optical transition radiation can be used to image small beams at high energy. The present paper describes the instrument and its performance. The authors tested the foil in, up to 180 μA of CW beam without causing noticeable beam loss, even at 800 MeV, the lowest CEBAF energy

Radiation workers of nuclear power stations and a method of regional economic development

International Nuclear Information System (INIS)

Nakagawa, Haruo

2003-01-01

In Japan, most of the electric power companies depend on radiation works to the external labor, but the employment of radiation works lacks its' stability. From the analysis on the mobility of radiation workers, we can see the stability of employment increases in proportion to the number of reactors. The radiation work is legally classified to harmful in Japan. And many health control systems for radiation workers are applied strictly. If we apply the health records registration system to the health control systems and involve them to the regional health care system, we can get more effective plan for regional economic development. It is therefore, very important to strive for employee controls, radiation controls, health examinations and data control. Furthermore, it is necessary to establish a total data management system that processes numerous amounts of data concerning radiation employees. This paper proposes the need for such a registration system to set up the system within regional medical information systems, and proposes the establishment of a radiation work market on the web using a total data management system. The system will include radiation employee control information service for members who are planning new employment contracts. (author)

Generation of auroral kilometric radiation and the structure of auroral acceleration region

International Nuclear Information System (INIS)

Lee, L.C.; Kan, J.R.; Wu, C.S.

1980-01-01

Generation of auroral kilometric radiation (AKR) in the auroral acceleration region is studied. It is shown that auroral kilometric radiation can be generated by the backscattered electrons trapped in the acceleration region via a cyclotron maser process. The parallel electric field in the acceleration region is required to be distributed over 1-2 Rsub(E). The observed AKR frequency spectrum can be used to estimate the altitude range of the auroral acceleration region. The altitudes of the lower and upper boundaries of the acceleration region determined from the AKR data are respectively approximately 2000 and approximately 9000 km. (author)

Assessment of natural background radiation in one of the highest regions of Ecuador

Science.gov (United States)

Pérez, Mario; Chávez, Estefanía; Echeverría, Magdy; Córdova, Rafael; Recalde, Celso

2018-05-01

Natural background radiation was measured in the province of Chimborazo (Ecuador) with the following reference coordinates 1°40'00''S 78°39'00''W, where the furthest point to the center of the planet is located. Natural background radiation measurements were performed at 130 randomly selected sites using a Geiger Müller GCA-07W portable detector; these measurements were run at 6 m away from buildings or walls and 1 m above the ground. The global average natural background radiation established by UNSCEAR is 2.4 mSv y-1. In the study area measurements ranged from 0.57 mSv y-1 to 3.09 mSv y-1 with a mean value of 1.57 mSv y-1, the maximum value was recorded in the north of the study area at 5073 metres above sea level (m.a.s.l.), and the minimum value was recorded in the southwestern area at 297 m.a.s.l. An isodose map was plotted to represent the equivalent dose rate due to natural background radiation. An analysis of variance (ANOVA) between the data of the high and low regions of the study area showed a significant difference (p < α), in addition a linear correlation coefficient of 0.92 was obtained, supporting the hypothesis that in high altitude zones extraterrestrial radiation contributes significantly to natural background radiation.

Amorphous chalcogenide semiconductors for solid state dosimetric systems of high-energetic ionizing radiation

International Nuclear Information System (INIS)

Shpotyuk, O.

1997-01-01

The application possibilities of amorphous chalcogenide semiconductors use as radiation-sensitive elements of high-energetic (E > 1 MeV) dosimetric systems are analysed. It is shown that investigated materials are characterized by more wide region of registered absorbed doses and low temperature threshold of radiation information bleaching in comparison with well-known analogies based on coloring oxide glasses. (author)

High spatial resolution radiation budget for Europe: derived from satellite data, validation of a regional model; Raeumlich hochaufgeloeste Strahlungsbilanz ueber Europa: Ableitung aus Satellitendaten, Validation eines regionalen Modells

Energy Technology Data Exchange (ETDEWEB)

Hollmann, R. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

2000-07-01

Since forty years instruments onboard satellites have been demonstrated their usefulness for many applications in the field of meteorology and oceanography. Several experiments, like ERBE, are dedicated to establish a climatology of the global Earth radiation budget at the top of the atmosphere. Now the focus has been changed to the regional scale, e.g. GEWEX with its regional sub-experiments like BALTEX. To obtain a regional radiation budget for Europe in the first part of the work the well calibrated measurements from ScaRaB (scanner for radiation budget) are used to derive a narrow-to-broadband conversion, which is applicable to the AVHRR (advanced very high resolution radiometer). It is shown, that the accuracy of the method is in the order of that from SCaRaB itself. In the second part of the work, results of REMO have been compared with measurements of ScaRaB and AVHRR for March 1994. The model reproduces the measurements overall well, but it is overestimating the cold areas and underestimating the warm areas in the longwave spectral domain. Similarly it is overestimating the dark areas and underestimating the bright areas in the solar spectral domain. (orig.)

Contrasting regional versus global radiative forcing by megacity pollution emissions

Science.gov (United States)

Dang, H.; Unger, N.

2015-10-01

We assess the regional and global integrated radiative forcing on 20- and 100-year time horizons caused by a one-year pulse of present day pollution emissions from 10 megacity areas: Los Angeles, Mexico City, New York City, Sao Paulo, Lagos, Cairo, New Delhi, Beijing, Shanghai and Manila. The assessment includes well-mixed greenhouse gases: carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4); and short-lived climate forcers: tropospheric ozone (O3) and fine mode aerosol particles (sulfate, nitrate, black carbon, primary and secondary organic aerosol). All megacities contribute net global warming on both time horizons. Most of the 10 megacity areas exert a net negative effect on their own regional radiation budget that is 10-100 times larger in magnitude than their global radiative effects. Of the cities examined, Beijing, New Delhi, Shanghai and New York contribute most to global warming with values ranging from +0.03 to 0.05 Wm-2yr on short timescales and +0.07-0.10 Wm-2yr on long timescales. Regional net 20-year radiative effects are largest for Mexico City (-0.84 Wm-2yr) and Beijing (-0.78 Wm-2yr). Megacity reduction of non-CH4 O3 precursors to improve air quality offers zero co-benefits to global climate. Megacity reduction of aerosols to improve air quality offers co-benefits to the regional radiative budget but minimal or no co-benefits to global climate with the exception of black carbon reductions in a few cities, especially Beijing and New Delhi. Results suggest that air pollution and global climate change mitigation can be treated as separate environmental issues in policy at the megacity level with the exception of CH4 action. Individual megacity reduction of CO2 and CH4 emissions can mitigate global warming and therefore offers climate safety improvements to the entire planet.

Campbell-Bristow development Model for Estimating Global Solar radiation in the Region of Junin, Perú

Directory of Open Access Journals (Sweden)

Dr. Becquer Frauberth Camayo-Lapa

2015-11-01

Full Text Available In order to have a tool to estimate the monthly and annual solar radiation on the horizontal surface in Junín region, in which is not available with this information, adapted Bristow-Campbell (1984 model for estimating global solar radiation monthly average.   To develop the model of Bristow-Campbell that estimates the average daily global solar radiation monthly modeling technique proposed by Espinoza (2010, were recorded daily maximum and minimum temperatures of 19 weather stations and the equations proposed  by the Solar High Peru 2003 was adapted to this model.  The Bristow-Campbell model was developed with data recorded in stations: Santa Ana, Tarma and Satipo belonging to Sierra and Selva, respectively. The performance of applications calculated solar radiation was determined by considering the OLADE (1992 that solar radiation over 4,0 kWh/m2/day are profitable and 5,0 kWh/m2/day very profitable. The results indicate that the monthly average global solar radiation in Junín  region is 5,3  kWh/m2/day corresponding to the  4,2 Forest and the Sierra 5,6 kWh/m2/day kWh/m2/day. Profitability is determined for the less profitable Selva and Sierra is very profitable. In addition, the operating model is simple and available to all users. We conclude that application of the Bristow-Campbell model adapted, it is an instrument of great utility to generate a comprehensive database of available solar radiation in Junín region.

Radiation levels in the SSC interaction regions

Energy Technology Data Exchange (ETDEWEB)

Groom, D.E. [ed.

1988-06-10

The radiation environment in a typical SSC detector has been evaluated using the best available particle production models coupled with Monte Carlo simulations of hadronic and electromagnetic cascades. The problems studied include direct charged particle dose, dose inside a calorimeter from the cascades produced by incident photons and hadrons, the flux of neutrons and photons backscattered from the calorimeter into a central cavity, and neutron flux in the calorimeter. The luminosity lifetime at the SSC is dominated by collision losses in the interaction regions, where the luminosity is equivalent to losing an entire full-energy proton beam into the apparatus every six days. The result of an average p-p collision can be described quite simply. The mean charged multiplicity is about 110, and the particles are distributed nearly uniformly in pseudorapidity ({eta}) over all the angles of interest. The transverse momentum distribution is independent of angle, and for our purposes may be written as p{perpendicular}exp(-p{perpendicular}/{beta}). The mean value of p{perpendicular} may be as high as 0.6 GeV/c. Most of the radiation is produced by the very abundant low-p{perpendicular} particles. The dose or neutron fluence produced by individual particles in this energy region are simulated over a wide variety of conditions, and several measurements serve to confirm the simulation results. In general, the response (a dose, fluence, the number of backscattered neutrons, etc.) for an incident particle of momentum p can be parameterized in the form Np{sup {alpha}}, where 0.5 < {alpha}< 1.0. The authors believe most of their results to be accurate to within a factor of two or three, sufficiently precise to serve as the basis for detailed designs.

High dose radiation damage in nuclear energy structural materials investigated by heavy ion irradiation simulation

International Nuclear Information System (INIS)

Zheng Yongnan; Xu Yongjun; Yuan Daqing

2014-01-01

Structural materials in ITER, ADS and fast reactor suffer high dose irradiations of neutrons and/or protons, that leads to severe displacement damage up to lOO dpa per year. Investigation of radiation damage induced by such a high dose irradiation has attracted great attention along with the development of nuclear energy facilities of new generation. However, it is deeply hampered for the lacking of high dose neutron and proton sources. Irradiation simulation of heavy ions produced by accelerators opens up an effective way for laboratory investigation of high dose irradiation induced radiation damage encountered in the ITER, ADS, etc. Radiation damage is caused mainly by atomic displacement in materials. The displacement rate of heavy ions is about lO 3 ∼10 7 orders higher than those of neutrons and protons. High displacement rate of heavy ions significantly reduces the irradiation time. The heavy ion irradiation simulation technique (HIIS) technique has been developed at China Institute of Atomic Energy and a series of the HIIS experiments have been performed to investigate radiation damage in stainless steels, tungsten and tantalum at irradiation temperatures from room temperature to 800 ℃ and in the irradiation dose region up to 100 dpa. The experimental results show that he radiation swelling peak for the modified stainless steel appears in the temperature region around 580 ℃ and the radiation damage is more sensitive to the temperature, the size of the radiation induced vacancy cluster or void increase with the increasing of the irradiation dose, and among the three materials the home-made modified stainless steel has the best radiation resistant property. (authors)

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

Panhypopituitarism arising after radiation therapy for germinoma in the suprasellar region. Case report

Energy Technology Data Exchange (ETDEWEB)

Maeyama, Masataka; Toribe, Yasuhisa; Adachi, Kouichi; Arita, Kouji [Itami Municipal Hospital, Hyogo (Japan)

1995-01-01

A case is presented in which panhypopituitarism occurred in an 8-year-old girl after radiation therapy for germinoma in the suprasellar region. The patient was referred to the hospital because of polydipsia and polyhydruria. She was diagnosed as having pituitary diabetes insipidus by water limitation test. Cranial CT and MRI revealed germinoma in the suprasellar region. Tumor cells were remarkably reduced by tentative irradiation. Thus the patient was treated with whole-body irradiation. Subsequently, she had general fatigue, loss of appetite, and activity decrease. The reaction to TRH test was low. ACTH secretion insufficiency was revealed by insulin test. The patient developed panhypopituitarism associated with GH and ADH secretion insufficiency. She has been managed on hormonal therapy, including DDAVP, hydrocortisone, and Levothyroxine. Although germinoma is highly sensitive to radiation, a long-term follow up is required because of the potential occurrence of postoperative sequelae. (N.K.).

Panhypopituitarism arising after radiation therapy for germinoma in the suprasellar region. Case report

International Nuclear Information System (INIS)

Maeyama, Masataka; Toribe, Yasuhisa; Adachi, Kouichi; Arita, Kouji

1995-01-01

A case is presented in which panhypopituitarism occurred in an 8-year-old girl after radiation therapy for germinoma in the suprasellar region. The patient was referred to the hospital because of polydipsia and polyhydruria. She was diagnosed as having pituitary diabetes insipidus by water limitation test. Cranial CT and MRI revealed germinoma in the suprasellar region. Tumor cells were remarkably reduced by tentative irradiation. Thus the patient was treated with whole-body irradiation. Subsequently, she had general fatigue, loss of appetite, and activity decrease. The reaction to TRH test was low. ACTH secretion insufficiency was revealed by insulin test. The patient developed panhypopituitarism associated with GH and ADH secretion insufficiency. She has been managed on hormonal therapy, including DDAVP, hydrocortisone, and Levothyroxine. Although germinoma is highly sensitive to radiation, a long-term follow up is required because of the potential occurrence of postoperative sequelae. (N.K.)

Radiation exposure map based on fuzzy logic for the representation of areas with high natural background

International Nuclear Information System (INIS)

Vasconcelos, Wagner Eustaquio de; Lira, Carlos Alberto Brayner de Oliveira

2009-01-01

The identification of areas with high concentrations of natural radionuclides is an important task in classifying these areas in relation to the health risk for residents in the region. The aim of this work is to identify areas of high exposure to nuclear radiation using a geographic representation based on the theory of fuzzy sets. Radiometric data obtained from previous works developed in a region of high concentrations in natural uranium were used to create a fuzzy map of the local radiation levels. During the image processing, a nonlinear filter was applied to eliminate noise i.e. to reduce isolated pixels that would eventually cause major uncertainties in the results. A resulting image was geographically positioned (WGS40) and obtained in gray scale. This image was fuzzified for membership functions that represent linguistic variables as low exposure, medium exposure and high exposure. After representing the membership grade in a RGB (red, green and blue) image it was possible to visualize the radiation level in the area of exposure. When compared to data from the region, results demonstrated the good efficiency of the technique here employed for the representation of areas with high radioactivity levels. The image obtained also provided important information about those areas where exposure to radiation is more pronounced. Hence, the fuzzy map can be applied in decision-making of experts when a risk situation is identified. (author)

Amorphous chalcogenide semiconductors for solid state dosimetric systems of high-energetic ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Shpotyuk, O. [Pedagogical University, Czestochowa (Poland)]|[Institute of Materials, Lvov (Ukraine)

1997-12-31

The application possibilities of amorphous chalcogenide semiconductors use as radiation-sensitive elements of high-energetic (E > 1 MeV) dosimetric systems are analysed. It is shown that investigated materials are characterized by more wide region of registered absorbed doses and low temperature threshold of radiation information bleaching in comparison with well-known analogies based on coloring oxide glasses. (author). 16 refs, 1 tab.

Study on aerosol optical properties and radiative effect in cloudy weather in the Guangzhou region

Energy Technology Data Exchange (ETDEWEB)

Deng, Tao, E-mail: tdeng@grmc.gov.cn [Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou 510080 (China); Deng, XueJiao; Li, Fei [Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou 510080 (China); Wang, ShiQiang [Zhuhai Meteorological Administration, Zhuhai 519000 (China); Wang, Gang [Haizhu Meteorological Administration, Guangzhou, 510000 (China)

2016-10-15

Currently, Guangzhou region was facing the problem of severe air pollution. Large amount of aerosols in the polluted air dramatically attenuated solar radiation. This study investigated the vertical optical properties of aerosols and inverted the height of boundary layer in the Guangzhou region using the lidar. Simultaneously, evaluated the impact of different types of clouds on aerosol radiation effects using the SBDART. The results showed that the height of the boundary layer and the surface visibility changed consistently, the average height of the boundary layer on the hazy days was only 61% of that on clear days. At the height of 2 km or lower, the aerosol extinction coefficient profile distribution decreased linearly along with height on clear days, but the haze days saw an exponential decrease. When there was haze, the changing of heating rate of atmosphere caused by the aerosol decreased from 3.72 K/d to 0.9 K/d below the height of 2 km, and the attenuation of net radiation flux at the ground surface was 97.7 W/m{sup 2}, and the attenuation amplitude was 11.4%; when there were high clouds, the attenuation was 125.2 W/m{sup 2} and the attenuation amplitude was 14.6%; where there were medium cloud, the attenuation was 286.4 W/m{sup 2} and the attenuation amplitude was 33.4%. Aerosol affected mainly shortwave radiation, and affected long wave radiation very slightly. - Highlights: • Large amount of aerosols dramatically attenuated solar radiation in Guangzhou region. • Investigated the aerosol extinction coefficient profile distribution and inverted the height of boundary layer using the lidar • Evaluated the impact of different types of clouds on aerosol radiation effects.

Aerosol Radiative Impact on the Middle East Regional Climate and the Red Sea

KAUST Repository

Osipov, Sergey

2017-10-01

The climate in the Middle East is complex and remains poorly understood. Due to the vast Arabian Desert, it is very sensitive to radiative forcing. Mineral dust is the dominant aerosol in this region. High background dust loading and frequent dust outbreaks significantly perturb the radiative balance and contribute to climate variability in the Middle East. To assess the climatological impact of dust in the region, we derived the aerosol optical properties and used a standalone column model to quantify radiative forcing sensitivity to a range of parameters representative of the Arabian Peninsula and the Red Sea. Simulations and modeling assumptions were validated using available in situ observations and satellite retrievals for fair weather and dust storm conditions. We incorporated the optical properties into the regional coupled ocean-atmosphere model and conducted simulations that represent the regional climate. The analysis shows that dust cools the Earth-atmosphere system and thus offsets the warming due to greenhouse gases. Dust reduces the sea surface temperature by 0.4 K, significantly perturbs energy balance, overturning circulation, and its purely dynamical impact reduces biological productivity in the Red Sea. In the real world, dust is present permanently and this does not allow to directly observe the climate response to the dust forcing. Volcanic eruptions produce a transient radiative impact that causes a detectable climate response that could be evaluated from observations and compared with simulations. Large equatorial eruptions are known to significantly perturb the Earth’s climate on the global scale, but their regional impact on the Middle East has not been thoroughly investigated. For example, the 1991 Mount Pinatubo eruption had a profound effect on the MENA and caused extensive coral bleaching in the Gulf of Aqaba. The analysis shows that observed cooling in the Middle East was mostly driven by changes in the atmospheric large

An investigation of tropical Atlantic bias in a high-resolution coupled regional climate model

Energy Technology Data Exchange (ETDEWEB)

Patricola, Christina M.; Saravanan, R.; Hsieh, Jen-Shan [Texas A and M University, Department of Atmospheric Sciences, College Station, TX (United States); Li, Mingkui; Xu, Zhao [Texas A and M University, Department of Oceanography, College Station, TX (United States); Ocean University of China, Key Laboratory of Physical Oceanography of Ministry of Education, Qingdao (China); Chang, Ping [Texas A and M University, Department of Oceanography, College Station, TX (United States); Ocean University of China, Key Laboratory of Physical Oceanography of Ministry of Education, Qingdao (China); Second Institute of Oceanography, State Key Laboratory of Satellite Ocean Environment Dynamics, Hangzhou, Zhejiang (China)

2012-11-15

Coupled atmosphere-ocean general circulation models (AOGCMs) commonly fail to simulate the eastern equatorial Atlantic boreal summer cold tongue and produce a westerly equatorial trade wind bias. This tropical Atlantic bias problem is investigated with a high-resolution (27-km atmosphere represented by the Weather Research and Forecasting Model, 9-km ocean represented by the Regional Ocean Modeling System) coupled regional climate model. Uncoupled atmospheric simulations test climate sensitivity to cumulus, land-surface, planetary boundary layer, microphysics, and radiation parameterizations and reveal that the radiation scheme has a pronounced impact in the tropical Atlantic. The CAM radiation simulates a dry precipitation (up to -90%) and cold land-surface temperature (up to -8 K) bias over the Amazon related to an over-representation of low-level clouds and almost basin-wide westerly trade wind bias. The Rapid Radiative Transfer Model and Goddard radiation simulates doubled Amazon and Congo Basin precipitation rates and a weak eastern Atlantic trade wind bias. Season-long high-resolution coupled regional model experiments indicate that the initiation of the warm eastern equatorial Atlantic sea surface temperature (SST) bias is more sensitive to the local rather than basin-wide trade wind bias and to a wet Congo Basin instead of dry Amazon - which differs from AOGCM simulations. Comparisons between coupled and uncoupled simulations suggest a regional Bjerknes feedback confined to the eastern equatorial Atlantic amplifies the initial SST, wind, and deepened thermocline bias, while barrier layer feedbacks are relatively unimportant. The SST bias in some CRCM simulations resembles the typical AOGCM bias indicating that increasing resolution is unlikely a simple solution to this problem. (orig.)

Analysis of the radiation budget in regional climate simulations with COSMO-CLM for Africa

Directory of Open Access Journals (Sweden)

Steffen Kothe

2014-09-01

Full Text Available This study analysed two regional climate simulations for Africa regarding the radiation budgets with particular focus on the contribution of potentially influential parameters on uncertainties in the radiation components. The ERA-Interim driven simulations have been performed with the COSMO-CLM (grid-spacings of 0.44 ° or 0.22 °. The simulated budgets were compared to the satellite-based Global Energy and Water Cycle Experiment Surface Radiation Budget and ERA-Interim data sets. The COSMO-CLM tended to underestimate the net solar radiation and the outgoing long-wave radiation, and showed a regionally varying over- or underestimation in all budget components. An increase in horizontal resolution from 0.44 ° to 0.22 ° slightly reduced the mean errors by up to 5 %. Especially over sea regions, uncertainties in cloud fraction were the main influencing parameter on errors in the simulated radiation fluxes. Compared to former simulations the introduction of a new bare soil albedo treatment reduced the influence of uncertainties in surface albedo significantly. Over the African continent errors in aerosol optical depth and skin temperature were regionally important sources for the discrepancies within the simulated radiation. In a sensitivity test it was shown that the use of aerosol optical depth values from the MACC reanalysis product improved the simulated surface radiation substantially.

The Effect of Land Cover/Land Use Changes on the Regional Climate of the USA High Plains

Directory of Open Access Journals (Sweden)

Denis Mutiibwa

2014-08-01

Full Text Available We present the detection of the signatures of land use/land cover (LULC changes on the regional climate of the US High Plains. We used the normalized difference vegetation index (NDVI as a proxy of LULC changes and atmospheric CO2 concentrations as a proxy of greenhouse gases. An enhanced signal processing procedure was developed to detect the signatures of LULC changes by integrating autoregression and moving average (ARMA modeling and optimal fingerprinting technique. The results, which are representative of the average spatial signatures of climate response to LULC change forcing on the regional climate of the High Plains during the 26 years of the study period (1981–2006, show a significant cooling effect on the regional temperatures during the summer season. The cooling effect was attributed to probable evaporative cooling originating from the increasing extensive irrigation in the region. The external forcing of atmospheric CO2 was included in the study to suppress the radiative warming effect of greenhouse gases, thus, enhancing the LULC change signal. The results show that the greenhouse gas radiative warming effect in the region is significant, but weak, compared to the LULC change signal. The study demonstrates the regional climatic impact of anthropogenic induced atmospheric-biosphere interaction attributed to LULC change, which is an additional and important climate forcing in addition to greenhouse gas radiative forcing in High Plains region.

High energy radiation detector

International Nuclear Information System (INIS)

Vosburgh, K.G.

1975-01-01

The high energy radiation detector described comprises a set of closely spaced wedge reflectors. Each wedge reflector is composed of three sides forming identical isoceles triangles with a common apex and an open base forming an equilateral triangle. The length of one side of the base is less than the thickness of the coat of material sensitive to high energy radiation. The wedge reflectors reflect the light photons spreading to the rear of the coat in such a way that each reflected track is parallel to the incident track of the light photon spreading rearwards. The angle of the three isosceles triangles with a common apex is between 85 and 95 deg. The first main surface of the coat of high energy radiation sensitive material is in contact with the projecting edges of the surface of the wedge reflectors of the reflecting element [fr

Photoacoustical and pyroelectric dosimetry of X-ray radiation in diagnostic region

International Nuclear Information System (INIS)

Carvalho, A.A. de.

1987-01-01

Three new types of radiation dosimeters, designed to measure X rays in its diagnostic region are described: the pulsed photoacoustical radiation dosimeter, the pyroelectric radiation dosimeter and the pulsed pyroelectric radiation dosimeter. The photoacoustical radiation dosimeter with the scope of to compare its carachteristics with the carachteristics of the new developed dosimeters is also studied. A methodology for calibration of a photoacoustical dosimeter which doesn't require the calibration of its response in a known field of ionizing radiation is proposed. A theoretical model to explain the results produced by the pulsed pyroelectric radiation dosimeter is presented. The obtained results show that the developed dosimeters are of calorimetric type, being linear its response with the X ray energy fluence rate. (author) [pt

Calibration of high-dose radiation facilities (Handbook)

International Nuclear Information System (INIS)

Gupta, B.L.; Bhat, R.M.

1986-01-01

In India at present several high intensity radiation sources are used. There are 135 teletheraphy machines and 65 high intensity cobalt-60 sources in the form of gamma chambers (2.5 Ci) and PANBIT (50 Ci). Several food irradiation facilities and a medical sterilization plant ISOMED are also in operation. The application of these high intensity sources involve a wide variation of dose from 10 Gy to 100 kGy. Accurate and reproducible radiation dosimetry is essential in the use of these sources. This handbook is especially compiled for calibration of high-dose radiation facilities. The first few chapters discuss such topics as interaction of radiation with matter, radiation chemistry, radiation processing, commonly used high intensity radiation sources and their special features, radiation units and dosimetry principles. In the chapters which follow, chemical dosimeters are discussed in detail. This discussion covers Fricke dosimeter, FBX dosimeter, ceric sulphate dosimeter, free radical dosimetry, coloured indicators for irrdiation verification. A final chapter is devoted to practical hints to be followed in calibration work. (author)

The impact of radiation belts region on top side ionosphere condition during last solar minimum.

Science.gov (United States)

Rothkaehl, Hanna; Przepiórka, Dororta; Matyjasiak, Barbara

2014-05-01

The wave particle interactions in radiation belts region are one of the key parameters in understanding the global physical processes which govern the near Earth environment. The populations of outer radiation belts electrons increasing in response to changes in the solar wind and the interplanetary magnetic field, and decreasing as a result of scattering into the loss cone and subsequent absorption by the atmosphere. The most important question in relation to understanding the physical processes in radiation belts region relates to estimate the ratio between acceleration and loss processes. This can be also very useful for construct adequate models adopted in Space Weather program. Moreover the wave particle interaction in inner radiation zone and in outer radiation zone have significant influence on the space plasma property at ionospheric altitude. The aim of this presentation is to show the manifestation of radiation belts region at the top side ionosphere during the last long solar minimum. The presentation of longitude and seasonal changes of plasma parameters affected by process occurred in radiation belts region has been performed on the base of the DEMETER and COSMIC 3 satellite registration. This research is partly supported by grant O N517 418440

Effect of active-region “volume” on the radiative properties of laser heterostructures with radiation output through the substrate

Energy Technology Data Exchange (ETDEWEB)

Nekorkin, S. M.; Zvonkov, B. N.; Baidus, N. V.; Dikareva, N. V., E-mail: dnat@ro.ru; Vikhrova, O. V. [Nizhny Novgorod State University, Physicotechnical Research Institute (Russian Federation); Afonenko, A. A.; Ushakov, D. V. [Belarussian State University (Belarus)

2017-01-15

The radiative properties of InGaAs/GaAs/InGaP laser structures with radiation output through the substrate depending on the number of quantum wells in the active region and laser diodes on their basis are investigated. It is established that the presence of six–eight quantum wells in the active region is optimum from the viewpoint of observable values of the threshold current and the output optical power of lasers.

Radiation protection monitoring. Proceedings of a regional seminar for Asia and the Far East on radiation protection monitoring

International Nuclear Information System (INIS)

1969-01-01

Proceedings of a regional seminar for Asia and the Far East jointly organized by the IAEA and the World Health Organization, and held in Bombay, 9-13 December 1968. The meeting was attended by 83 participants from 12 countries In the region, and by eight experts from countries outside the region who presented review papers. Contents: Purpose of radiation protection monitoring (4 papers); Radiation monitoring and dosimetry (7 papers); Monitoring of the working environment (12 papers); Individual monitoring (14 papers); Monitoring instruments (7 papers); Calibration and maintenance of instruments (3 papers); List of participants; Author index. All papers, which are preceded by an abstract, as well as the discussions, are in English

GAMMA–GAMMA ABSORPTION IN THE BROAD LINE REGION RADIATION FIELDS OF GAMMA-RAY BLAZARS

Energy Technology Data Exchange (ETDEWEB)

Böttcher, Markus; Els, Paul, E-mail: Markus.Bottcher@nwu.ac.za [Centre for Space Research, North-West University, Potchefstroom, 2531 (South Africa)

2016-04-20

The expected level of γγ absorption in the Broad Line Region (BLR) radiation field of γ -ray loud Flat Spectrum Radio Quasars (FSRQs) is evaluated as a function of the location of the γ -ray emission region. This is done self-consistently with parameters inferred from the shape of the spectral energy distribution (SED) in a single-zone leptonic EC-BLR model scenario. We take into account all geometrical effects both in the calculation of the γγ opacity and the normalization of the BLR radiation energy density. As specific examples, we study the FSRQs 3C279 and PKS 1510-089, keeping the BLR radiation energy density at the location of the emission region fixed at the values inferred from the SED. We confirm previous findings that the optical depth due to γγ absorption in the BLR radiation field exceeds unity for both 3C279 and PKS 1510-089 for locations of the γ -ray emission region inside the inner boundary of the BLR. It decreases monotonically, with distance from the central engine and drops below unity for locations within the BLR. For locations outside the BLR, the BLR radiation energy density required for the production of GeV γ -rays rapidly increases beyond observational constraints, thus making the EC-BLR mechanism implausible. Therefore, in order to avoid significant γγ absorption by the BLR radiation field, the γ -ray emission region must therefore be located near the outer boundary of the BLR.

Quantitative status of resources for radiation therapy in Asia and Pacific region

International Nuclear Information System (INIS)

Tatsuzaki, Hideo; Levin, Cecil Victor

2001-01-01

Purpose: Resources for radiation therapy in Asian and Pacific countries were analyzed to obtain a better understanding of the status of radiation oncological practice in the region. Methods and Materials: The data were obtained mainly through surveys on the availability of major equipment and personnel which were conducted through an International Atomic Energy Agency regional project. The study included 17 countries in South Asia, South East Asia, East Asia and Australasia. Data were related to national populations and economic and a general health care indices. Results: Large differences in equipment and personnel among countries were demonstrated. The availability of both teletherapy and brachytherapy was related to the economic status of the countries. The shortage of teletherapy machines was evident in more countries than that of brachytherapy. Many departments were found to treat patients without simulators or treatment planning systems. The number of radiation oncologists standardized by cancer incidence of a country did not correlate well with economic status. Conclusions: There were significant deficiencies in the availability of all components of radiation therapy in the analyzed countries. The deficiencies were linked predominantly to the economic status of the country. Cognisance should be taken of the specific shortfalls in each country to ensure that expansion or any assistance offered appropriately match its needs and can be fully utilized. The information on the resources currently available for radiation oncological practice in the region presented in this paper provides a valuable basis for planning of development aid programs on radiation therapy

Experimental microdosimetry in high energy radiation fields

International Nuclear Information System (INIS)

Spurny, F.; Bednar, J.; Vlcek, B.; Bottollier-Depois, J.-F.; Molokanov, A.G.

2000-01-01

To determine microdosimetric characteristics in the beams and fields of high energy panicles with the goal, also, to compare the classical method of experimental microdosimetry, a tissue equivalent low pressure proportional counter (TEPC) with the linear energy transfer (LET) spectrometer based on a chemically etched polyallyldiglycolcarbonate as a track etched detector (TED). To test the use of TED LET spectrometer in the conditions, where the use or TEPC is not possible (high energy charged particle beams at high dose rates). The results obtained with the TEPC NAUSICAA were used in this work to compare them with other data. This TEPC measures directly the linear energy in the interval between 0.15 and 1500 keV/μm in tissue, the low gas pressure (propan based TE mixture) permits to simulate a tissue element of about 3 μm. It can be used in the fields with instantaneous dose equivalent rates between 1 μSv/hour and 1 mSv/ hour. TED LET spectrometer developed to determine LET spectra between 10 and 700 keV/μm in tissue. Primarily, track-to-bulk etch rate ratios are determined through the track parameters measurements, the spectra of these ratios are convened to LET spectra using the calibration curve established by means of heavy charge panicles. The critical volume of thi spectrometer is supposed to be a few nm. There is no limit of use for the dose rate, the background tracks limit the lowest threshold to about 1 mSv, the overlapping of tracks (the highest one) to 100 mSv. Both experimental microdosimetry methods have been used in on board aircraft radiation fields, in on-Earth high energy radiation reference fields, and in the beams of protons with energies up to 300 MeV (Dubna, Moscow, Loma Linda). First, it should be emphasized, that in all high energy radiation fields studied, we concentrated our analysis on the region, where both methods overlap, i.e. between 10 and 1000 keV/μm in tissue. It should be also stressed, that the events observed in this region

Measurement of circumsolar ratio in high dust loading regions using a photographic method

Science.gov (United States)

Al-Ansary, Hany; Shafiq, Talha; Rizvi, Arslan; El-Leathy, Abdelrahman

2017-06-01

Performance of concentrating solar power (CSP) plants is highly affected by direct normal irradiance (DNI). However, it is also important to consider circumsolar radiation in any simulation of a CSP plant, especially in desert regions where dust loading in the atmosphere is expected. There are a number of methods to measure circumsolar radiation. However, most of them require expensive instrumentation. This work introduces a simple method to estimate circumsolar radiation. It involves taking high-resolution photographs of the sun and processing them using a computer code that identifies the sun's disk. The code then uses pixel intensities to obtain the solar intensity distribution across the sun's disk and in the aureole region. The solar intensity distribution is then used to obtain the circumsolar ratio (CSR) which represents the shape of the sun. To test this method, numerous photos of the sun were taken during the month of April and September 2016 at King Saud University in Riyadh, Saudi Arabia. Riyadh is a region that is well known for high dust-loading, especially during the summer. Two days of different atmospheric conditions were selected in September for comparative analysis. Results show that this method produces repeatable results, and that the CSR can increase significantly due to high dust loading and passing clouds. The CSR is found to be a strong function of DNI, ranging from about 4.5% at DNI values above 800 W/m2 and increasing to as much as 8.5% when DNI drops to about 400 W/m2, due to passing clouds. Furthermore, the results show that circumsolar ratio tends to be high in the early morning and late afternoon due to the high air mass, while its values tend to be lowest around solar noon when the air mass is lowest.

High energy particle accelerators as radiation Sources

Energy Technology Data Exchange (ETDEWEB)

Abdelaziz, M E [National Center for Nuclear Safety and Radiation Vontrol, Atomic Energy Authority, Cairo (Egypt)

1997-12-31

Small accelerators in the energy range of few million electron volts are usually used as radiation sources for various applications, like radiotherapy, food irradiation, radiation sterilization and in other industrial applications. High energy accelerators with energies reaching billions of electron volts also find wide field of applications as radiation sources. Synchrotrons with high energy range have unique features as radiation sources. This review presents a synopsis of cyclic accelerators with description of phase stability principle of high energy accelerators with emphasis on synchrotrons. Properties of synchrotron radiation are given together with their applications in basic and applied research. 13 figs.,1 tab.

Report of the radiation group on radiation backgrounds and damage in the ISABELLE intersection regions

International Nuclear Information System (INIS)

Ludlam, T.; Kistiakowsky, V.; Toohig, T.E.

1976-01-01

The Radiation Group was charged to examine radiation aspects of the current ISABELLE design and the projected experimental arrangements. Some samples of questions to be addressed were: (1) how does the overall shielding design impact the experimental design, (2) what backgrounds might be expected from the proposed beam scraping, shaving, etc. schemes, (3) what are the radiation damage considerations for experimental electronics near the beam, and (4) what backgrounds might be expected in an experiment from operation of another experiment in the same or the adjacent intersection region. A review is given based on the ISABELLE Proposal, The Proceedings of the 1975 ISABELLE Summer Study, and the estimate of ISABELLE shielding requirements by Stevens and Thorndike

Source region of aurora kilometric radiation

International Nuclear Information System (INIS)

Morioka, Akira; Oya, Hiroshi; Tokumaru, Munetoshi

1981-01-01

This paper discusses the source region of aurora kilometric radiation (AKR), and the relation between the particle acceleration region and the polar ionosphere. The observation was made by the satellite 'Jikiken'. The AKR can be transferred to Jikiken without any interception, when the magnetic latitude of the apogee of the satellite is low. The spectra taken in June, 1980, were analyzed. The observed spectra showed the source regions of the AKR were in the aurora bands of the north and south poles. One example showed that the 200 kHz component of AKR from both poles showed the similar behavior, and another example showed that the AKR spectra from both poles showed different behavior. The altitude distribution of source regions was able to be obtained. The altitude of AKR-A was in the range between 6200 and 12000 km, and that of AKR-B was in the range of 3500 and 5200 km. The source of AKR-A was identified as that in the south hemisphere, and that of AKR-B in the north hemisphere. The asymmetric spectra of AKR-A and B showed that the spread and intensity of the electric field along magnetic lines generated above the polar ionosphere were related with the conditions of the ionosphere. (Kato, T.)

Experimental study of intense radiation in terahertz region based on cylindrical surface wave resonator

International Nuclear Information System (INIS)

Gong, Shaoyan; Ogura, Kazuo; Yambe, Kiyoyuki; Nomizu, Shintaro; Shirai, Akihiro; Yamazaki, Kosuke; Kawamura, Jun; Miura, Takuro; Takanashi, Sho; San, Min Thu

2015-01-01

Periodical corrugations structured on a cylindrical conductor have cylindrical surface waves (CSWs), which are reflected at the corrugation ends and form a CSW-resonator. In this paper, intense radiations in terahertz region based on the CSW-resonator are reported. The CSW-resonators with upper cut off frequencies in the modern IEEE G-band (110–300 GHz) are excited by a coaxially injected annular beam in a weakly relativistic region less than 100 kV. It is shown that there exists an oscillation starting energy for the CSW-resonator. Above the starting energy, very intense terahertz radiations on the order of kW are obtained. The operation frequencies in the range of 166–173 GHz and 182–200 GHz are obtained using two types of CSW-resonator with the different corrugation amplitude. Electromagnetic properties of the CSW-resonator can be controlled by the artificial structure and may play an important role in high-intensity terahertz generations and applications

Impacts of spectral nudging on the simulated surface air temperature in summer compared with the selection of shortwave radiation and land surface model physics parameterization in a high-resolution regional atmospheric model

Science.gov (United States)

Park, Jun; Hwang, Seung-On

2017-11-01

The impact of a spectral nudging technique for the dynamical downscaling of the summer surface air temperature in a high-resolution regional atmospheric model is assessed. The performance of this technique is measured by comparing 16 analysis-driven simulation sets of physical parameterization combinations of two shortwave radiation and four land surface model schemes of the model, which are known to be crucial for the simulation of the surface air temperature. It is found that the application of spectral nudging to the outermost domain has a greater impact on the regional climate than any combination of shortwave radiation and land surface model physics schemes. The optimal choice of two model physics parameterizations is helpful for obtaining more realistic spatiotemporal distributions of land surface variables such as the surface air temperature, precipitation, and surface fluxes. However, employing spectral nudging adds more value to the results; the improvement is greater than using sophisticated shortwave radiation and land surface model physical parameterizations. This result indicates that spectral nudging applied to the outermost domain provides a more accurate lateral boundary condition to the innermost domain when forced by analysis data by securing the consistency with large-scale forcing over a regional domain. This consequently indirectly helps two physical parameterizations to produce small-scale features closer to the observed values, leading to a better representation of the surface air temperature in a high-resolution downscaled climate.

Validity of the linear no-threshold (LNT) hypothesis in setting radiation protection regulations for the inhabitants in high level natural radiation areas of Ramsar, Iran

International Nuclear Information System (INIS)

Mortazavi, S.M.J.; Atefi, M.; Razi, Z.; Mortazavi Gh

2010-01-01

Some areas in Ramsar, a city in northern Iran, have long been known as inhabited areas with the highest levels of natural radiation. Despite the fact that the health effects of high doses of ionizing radiation are well documented, biological effects of above the background levels of natural radiation are still controversial and the validity of the LNT hypothesis in this area, has been criticized by many investigators around the world. The study of the health effects of high levels of natural radiation in areas such as Ramsar, help scientists to investigate the biological effects without the need for extrapolating the observations either from high doses of radiation to low dose region or from laboratory animals to humans. Considering the importance of these studies, National Radiation Protection Department (NRPD) of the Iranian Nuclear Regulatory Authority has started an integrative research project on the health effects of long-term exposure to high levels of natural radiation. This paper reviews findings of the studies conducted on the plants and humans living or laboratory animals kept in high level natural radiation areas of Ramsar. In human studies, different end points such as DNA damage, chromosome aberrations, blood cells and immunological alterations are discussed. This review comes to the conclusion that no reproducible detrimental health effect has been reported so far. In this paper the validity of LNT hypothesis in the assessment of the health effects of high levels of natural radiation is discussed. (author)

Beam size measurement at high radiation levels

International Nuclear Information System (INIS)

Decker, F.J.

1991-05-01

At the end of the Stanford Linear Accelerator the high energy electron and positron beams are quite small. Beam sizes below 100 μm (σ) as well as the transverse distribution, especially tails, have to be determined. Fluorescent screens observed by TV cameras provide a quick two-dimensional picture, which can be analyzed by digitization. For running the SLAC Linear Collider (SLC) with low backgrounds at the interaction point, collimators are installed at the end of the linac. This causes a high radiation level so that the nearby cameras die within two weeks and so-called ''radiation hard'' cameras within two months. Therefore an optical system has been built, which guides a 5 mm wide picture with a resolution of about 30 μm over a distance of 12 m to an accessible region. The overall resolution is limited by the screen thickness, optical diffraction and the line resolution of the camera. Vibration, chromatic effects or air fluctuations play a much less important role. The pictures are colored to get fast information about the beam current, size and tails. Beside the emittance, more information about the tail size and betatron phase is obtained by using four screens. This will help to develop tail compensation schemes to decrease the emittance growth in the linac at high currents. 4 refs., 2 figs

High energy radiation from neutron stars

International Nuclear Information System (INIS)

Ruderman, M.

1985-04-01

Topics covered include young rapidly spinning pulsars; static gaps in outer magnetospheres; dynamic gaps in pulsar outer magnetospheres; pulse structure of energetic radiation sustained by outer gap pair production; outer gap radiation, Crab pulsar; outer gap radiation, the Vela pulsar; radioemission; and high energy radiation during the accretion spin-up of older neutron stars. 26 refs., 10 figs

Properties of a radiation-induced charge multiplication region in epitaxial silicon diodes

CERN Document Server

Lange, Jörn; Fretwurst, Eckhart; Klanner, Robert; Lindström, Gunnar

2010-01-01

Charge multiplication (CM) in p$^+$n epitaxial silicon pad diodes of 75, 100 and 150 $\\upmu$m thickness at high voltages after proton irradiation with 1 MeV neutron equivalent fluences in the order of $10^{16}$ cm$^{-2}$ was studied as an option to overcome the strong trapping of charge carriers in the innermost tracking region of future Super-LHC detectors. Charge collection efficiency (CCE) measurements using the Transient Current Technique (TCT) with radiation of different penetration (670, 830, 1060 nm laser light and $\\alpha$-particles with optional absorbers) were used to locate the CM region close to the p$^+$-implantation. The dependence of CM on material, thickness of the epitaxial layer, annealing and temperature was studied. The collected charge in the CM regime was found to be proportional to the deposited charge, uniform over the diode area and stable over a period of several days. Randomly occurring micro discharges at high voltages turned out to be the largest challenge for operation of the dio...

Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region

DEFF Research Database (Denmark)

Eiserhardt, Wolf L.; Rohwer, Jens G.; Russell, Stephen J.

2011-01-01

The Greater Cape Floristic Region (GCFR) of southern Africa is characterised by large, endemic radiations of flowering plants, the so-called ‘Cape Clades’, but it is unknown whether such radiations are also found in non-angiosperms. We hypothesise that GCFR-endemic lineages exist in the xeric...

Radiation effects on materials in high-radiation environments

International Nuclear Information System (INIS)

Weber, W.J.; Mansur, L.K.; Clinard, F.W. Jr.; Parkin, D.M.

1991-01-01

A workshop on Radiation Effects on Materials in High-Radiation Environments was held in Salt Lake City, Utah (USA) from August 13 to 15, 1990 under the auspices of the Division of Materials Sciences, Office of Basic Energy Sciences, US Department of Energy. The workshop focused on ceramics, alloys, and intermetallics and covered research needs and capabilities, recent experimental data, theory, and computer simulations. It was concluded that there is clearly a continuing scientific and technological need for fundamental knowledge on the underlying causes of radiation-induced property changes in materials. Furthermore, the success of many current and emerging nuclear-related technologies critically depend on renewed support for basic radiation-effects research, irradiation facilities, and training of scientists. The highlights of the workshop are reviewed and specific recommendations are made regarding research needs. (orig.)

RUNAWAY STARS AND THE ESCAPE OF IONIZING RADIATION FROM HIGH-REDSHIFT GALAXIES

International Nuclear Information System (INIS)

Conroy, Charlie; Kratter, Kaitlin M.

2012-01-01

Approximately 30% of all massive stars in the Galaxy are runaways with velocities exceeding 30 km s –1 . Their high speeds allow them to travel ∼0.1-1 kpc away from their birthplace before they explode at the end of their several Myr lifetimes. At high redshift, when galaxies were much smaller than in the local universe, runaways could venture far from the dense inner regions of their host galaxies. From these large radii, and therefore low column densities, much of their ionizing radiation is able to escape into the intergalactic medium. Runaways may therefore significantly enhance the overall escape fraction of ionizing radiation, f esc , from small galaxies at high redshift. We present simple models of the high-redshift runaway population and its impact on f esc as a function of halo mass, size, and redshift. We find that the inclusion of runaways enhances f esc by factors of ≈1.1-8, depending on halo mass, galaxy geometry, and the mechanism of runaway production, implying that runaways may contribute 50%-90% of the total ionizing radiation escaping from high-redshift galaxies. Runaways may therefore play an important role in reionizing the universe.

Thyroid nodularity and chromosome aberrations among women in areas of high background radiation in China

International Nuclear Information System (INIS)

Wang, Z.Y.; Boice, J.D. Jr.; Wei, L.X.; Beebe, G.W.; Zha, Y.R.; Kaplan, M.M.; Tao, Z.F.; Maxon, H.R. III; Zhang, S.Z.; Schneider, A.B.

1990-01-01

Thyroid nodularity following continuous low-dose radiation exposure in China was determined in 1,001 women aged 50-65 years who resided in areas of high background radiation (330 mR/yr) their entire lives, and in 1,005 comparison subjects exposed to normal levels of radiation (114 mR/yr). Cumulative doses to the thyroid were estimated to be of the order of 14 cGy and 5 cGy, respectively. Personal interviews and physical examinations were conducted, and measurements were made of serum thyroid hormone levels, urinary iodine concentrations, and chromosome aberrations in circulating lymphocytes. For all nodular disease, the prevalences in the high background and control areas were 9.5% and 9.3%, respectively. For single nodules, the prevalences were 7.4% in the high background area and 6.6% in the control area (prevalence ratio = 1.13; 95% confidence interval = 0.82-1.55). There were no differences found in serum levels of thyroid hormones. Women in the high background region, however, had significantly lower concentrations of urinary iodine and significantly higher frequencies of stable and unstable chromosome aberrations. Increased intake of allium vegetables such as garlic and onions was associated with a decreased risk of nodular disease, which seems consistent with experimental studies suggesting that allium compounds can inhibit tumor growth and proliferation. The prevalence of mild diffuse goiter was higher in the high background radiation region, perhaps related to a low dietary intake of iodine. These data suggest that continuous exposure to low-level radiation throughout life is unlikely to appreciably increase the risk of thyroid cancer. However, such exposure may cause chromosomal damage

Development of a high gradient quadrupole for the LHC Interaction Regions

International Nuclear Information System (INIS)

Bossert, R.; Feher, S.; Gourlay, S.A.

1997-04-01

A collaboration of Fermilab, Lawrence Berkeley National Laboratory and Brookhaven National Laboratory is engaged in the design of a high gradient quadrupole suitable for use in the LHC interaction regions. The cold iron design incorporates a two-layer, cos(2θ) coil geometry with a 70 mm aperture operating in superfluid helium. This paper summarizes the progress on a magnetic, mechanical and thermal design that meets the requirements of maximum gradient above 250 T/m, high field quality and provision for adequate cooling in a high radiation environment

Design of a High Gradient Quadrupole for the LHC Interaction Regions

International Nuclear Information System (INIS)

Bossert, R.; Gourlay, S.A.; Heger, T.; Huang, Y.; Kerby, J.; Lamm, M.J.; Limon, P.J.; Mazur, P.O.; Nobrega, F.; Ozelis, J.P.; Sabbi, G.; Strait, J.; Zlobin, A.V.; Caspi, S.; Dell'orco, D.; McInturff, A.D.; Scanlan, R.M.; Van Oort, J.M.; Gupta, R.C.

1997-03-01

A collaboration of Fermilab, Lawrence Berkeley National Laboratory and Brookhaven National Laboratory is currently engaged in the design of a high gradient quadrupole suitable for use in the LHC interaction regions. The cold iron design incorporates a two-shell, cos2θ coil geometry with a 70 mm aperture. This paper summarizes the progress on a magnetic and mechanical design that meets the requirements of maximum gradient ≥250 T/m, operation at 1.8K, high field quality and provision for adequate cooling in a high radiation environment

To question of radiation factors on onco-epidemiology in regions of Georgia

International Nuclear Information System (INIS)

Vepxadze, N.R.; Maqradze, Q.M.; Qoncilasvili, I.P.

2002-01-01

Full text: Planning of anticancer service is impossible without studying the actual dynamics and prognosis of diseases we have analyzed the morbidity and mortality rates for different regions conditioned by different ecological conditions in these regions. We have studied the space-structural features of extension of cancer as base of programme for recreative and preventive measures. It is shown that the dynamic of oncologic diseases in Georgian regions has a natural character and is not conditioned much by anthropogenic factor. 1. For regions exceeds death-rate that and points to validity processing statistical information, real reflecting regional particularities. 2.Simultaneously possible indicate that where average oncologic diseases exceeds checking point factors, alike death-rate level can point medical service to more high level of. 3.Migration of population, ethnic a spottiness really characteristic of some regions-on this reason insufficiently high general correlation factors and insufficiently mother a mistake prognostic regression equations. 4.As is 'cancer-discomfort' by the region that wholly follows from its ecological, and genetic features. Region is characterized moderate climate; extreme climatic parameters of external ambience here as a whole rare and low-probable; in the region of practically no bad production, polluting intensive surrounding ambience; region is agricultural, without intensive technical cultures already; social conditions of residence - moderate, no high density of population because of presence of greater areas and etc; stevedore is characterized by the person by temperance on fat and calorie content, on the base of wheat and corn bread; a general factor to correlations-a measure of relationship of chosen parameters pointing under investigation features, within 0,5 - 0,6 and above; a mistake of using an prognostic metaaluminate does not exceed 25% that sufficiently high factor, permitting practical using an prognostic equation

High risk Merkel cell carcinoma of the skin treated with synchronous carboplatin/etoposide and radiation: a trans-Tasman radiation oncology group study

International Nuclear Information System (INIS)

Poulsen, M.G.; Rischin, D.; Ainslie, J.; Walpole, E.; Harvey, J.; Mackintosh, J.; Hamilton, C.; Tripcony, L.

2003-01-01

The effectiveness of synchronous carboplatin, etoposide and radiation therapy was prospectively assessed in a group of patients with high risk Merkel Cell Carcinoma of the skin. Patients were eligible if they had disease localised to the primary site and nodes and were required to have at least one of the following high risk features: recurrence after initial therapy, involved nodes, primary size greater than 1 cm, gross residual disease after surgery or occult primary with nodes. Radiation was delivered to the primary site and nodes to a dose of 50 Gy in 25 fractions over 5 weeks and synchronous carboplatin (AUC 4.5) and etoposide 80 mg/M2 intravenously days 1-3 was given in weeks 1, 4, 7 and 10. The median age of the group was 67 [43-86] years and there were 39 males and 14 females. Involved nodes (stageII) were present in 33 (62%) cases. The sites involved in decreasing order were head and neck (22), occult primary (13), upper limb (8), lower limb (8) and trunk (2). Fifty-three patients were entered between 1996 and 2001.The median potential follow up was 48 months. There were no treatment related deaths. The 3 year overall survival, loco-regional control and distant control were 76%, 75% and 76% respectively. Factors that were predictive for local control and survival were tumour site and the presence of nodes. Multivariate analysis indicated that the major factor influencing survival was the presence of nodes. However this was not a significant factor in loco-regional control. High levels of loco-regional control and survival have been achieved with the addition of chemotherapy to radiation treatment for high risk Merkel cell carcinoma of skin. The role of chemo-radiotherapy for high risk MCC warrants further investigation

Sunshine-based estimation of global solar radiation on horizontal surface at Lake Van region (Turkey)

International Nuclear Information System (INIS)

Duzen, Hacer; Aydin, Harun

2012-01-01

Highlights: ► The global solar radiation at Lake Van region is estimated. ► This study is unique for the Lake Van region. ► Solar radiation around Lake Van has the highest value at the east-southeast region. ► The annual average solar energy potential is obtained as 750–2458 kWh/m 2 . ► Results can be used to estimate evaporation. - Abstract: In this study several sunshine-based regression models have been evaluated to estimate monthly average daily global solar radiation on horizontal surface of Lake Van region in the Eastern Anatolia region in Turkey by using data obtained from seven different meteorological stations. These models are derived from Angström–Prescott linear regression model and its derivatives such as quadratic, cubic, logarithmic and exponential. The performance of this regression models were evaluated by comparing the calculated clearness index and the measured clearness index. Several statistical tests were used to control the validation and goodness of the regression models in terms of the coefficient of determination, mean percent error, mean absolute percent error, mean biased error, mean absolute biased error, root mean square error and t-statistic. The results of all the regression models are within acceptable limits according to the statistical tests. However, the best performances are obtained by cubic regression model for Bitlis, Gevaş, Hakkari, Muş stations and by quadratic regression model for Malazgirt, Tatvan and Van stations to predict global solar radiation. The spatial distributions of the monthly average daily global solar radiation around the Lake Van region were obtained with interpolation of calculated solar radiation data that acquired from best fit models of the stations. The annual average solar energy potential for Lake Van region is obtained between 750 kWh/m 2 and 2485 kWh/m 2 with annual average of 1610 kWh/m 2 .

Modeling the radiative effects of biomass burning aerosols on carbon fluxes in the Amazon region

Science.gov (United States)

Moreira, Demerval S.; Longo, Karla M.; Freitas, Saulo R.; Yamasoe, Marcia A.; Mercado, Lina M.; Rosário, Nilton E.; Gloor, Emauel; Viana, Rosane S. M.; Miller, John B.; Gatti, Luciana V.; Wiedemann, Kenia T.; Domingues, Lucas K. G.; Correia, Caio C. S.

2017-12-01

Every year, a dense smoke haze covers a large portion of South America originating from fires in the Amazon Basin and central parts of Brazil during the dry biomass burning season between August and October. Over a large portion of South America, the average aerosol optical depth at 550 nm exceeds 1.0 during the fire season, while the background value during the rainy season is below 0.2. Biomass burning aerosol particles increase scattering and absorption of the incident solar radiation. The regional-scale aerosol layer reduces the amount of solar energy reaching the surface, cools the near-surface air, and increases the diffuse radiation fraction over a large disturbed area of the Amazon rainforest. These factors affect the energy and CO2 fluxes at the surface. In this work, we applied a fully integrated atmospheric model to assess the impact of biomass burning aerosols in CO2 fluxes in the Amazon region during 2010. We address the effects of the attenuation of global solar radiation and the enhancement of the diffuse solar radiation flux inside the vegetation canopy. Our results indicate that biomass burning aerosols led to increases of about 27 % in the gross primary productivity of Amazonia and 10 % in plant respiration as well as a decline in soil respiration of 3 %. Consequently, in our model Amazonia became a net carbon sink; net ecosystem exchange during September 2010 dropped from +101 to -104 TgC when the aerosol effects are considered, mainly due to the aerosol diffuse radiation effect. For the forest biome, our results point to a dominance of the diffuse radiation effect on CO2 fluxes, reaching a balance of 50-50 % between the diffuse and direct aerosol effects for high aerosol loads. For C3 grasses and savanna (cerrado), as expected, the contribution of the diffuse radiation effect is much lower, tending to zero with the increase in aerosol load. Taking all biomes together, our model shows the Amazon during the dry season, in the presence of high

Modeling the radiative effects of biomass burning aerosols on carbon fluxes in the Amazon region

Directory of Open Access Journals (Sweden)

D. S. Moreira

2017-12-01

Full Text Available Every year, a dense smoke haze covers a large portion of South America originating from fires in the Amazon Basin and central parts of Brazil during the dry biomass burning season between August and October. Over a large portion of South America, the average aerosol optical depth at 550 nm exceeds 1.0 during the fire season, while the background value during the rainy season is below 0.2. Biomass burning aerosol particles increase scattering and absorption of the incident solar radiation. The regional-scale aerosol layer reduces the amount of solar energy reaching the surface, cools the near-surface air, and increases the diffuse radiation fraction over a large disturbed area of the Amazon rainforest. These factors affect the energy and CO2 fluxes at the surface. In this work, we applied a fully integrated atmospheric model to assess the impact of biomass burning aerosols in CO2 fluxes in the Amazon region during 2010. We address the effects of the attenuation of global solar radiation and the enhancement of the diffuse solar radiation flux inside the vegetation canopy. Our results indicate that biomass burning aerosols led to increases of about 27 % in the gross primary productivity of Amazonia and 10 % in plant respiration as well as a decline in soil respiration of 3 %. Consequently, in our model Amazonia became a net carbon sink; net ecosystem exchange during September 2010 dropped from +101 to −104 TgC when the aerosol effects are considered, mainly due to the aerosol diffuse radiation effect. For the forest biome, our results point to a dominance of the diffuse radiation effect on CO2 fluxes, reaching a balance of 50–50 % between the diffuse and direct aerosol effects for high aerosol loads. For C3 grasses and savanna (cerrado, as expected, the contribution of the diffuse radiation effect is much lower, tending to zero with the increase in aerosol load. Taking all biomes together, our model shows the Amazon during the dry

Observations of MeV electrons in Jupiter's innermost radiation belts and polar regions by the Juno radiation monitoring investigation: Perijoves 1 and 3

DEFF Research Database (Denmark)

Becker, Heidi N.; Santos-Costa, Daniel; Jørgensen, John Leif

2017-01-01

Juno's “Perijove 1” (27 August 2016) and “Perijove 3” (11 December 2016) flybys through the innermost region of Jupiter's magnetosphere (radial distances ... Investigation collected particle counts and noise signatures from penetrating high-energy particle impacts in images acquired by the Stellar Reference Unit and Advanced Stellar Compass star trackers, and the Jupiter Infrared Auroral Mapper infrared imager. This coordinated observation campaign sampled radiation...

Intercomparison of personal radiation monitoring services in the Asia/Pacific region

International Nuclear Information System (INIS)

Young, J.G.; Hargrave, N.J.

1994-01-01

The Australian Radiation Laboratory conducted an international intercomparison of personal radiation monitoring services in the Asia/Pacific region during 1991. Twenty nine organizations from sixteen countries took part in the study, with the People's Republic of China having eleven participants. Dosemeters incorporating thermoluminescent phosphors and conventional film were submitted for evaluation. Both types were irradiated at normal incidence on a phantom with 137 Cs gamma rays, X rays and beta radiation from a 90 Sr/ 90 Y source. Participants were requested to assess their dosemeters in terms of the new operational quantities of the ICRU for personal radiation monitoring, in particular the personal dose equivalents H p (0.07) and H p (10). (author)

Investigation of variations and trends in solar radiation in Klang Valley Region, Malaysia

International Nuclear Information System (INIS)

Mohamed Elnour Yassen, Jamaluddin Mohd Jahi

2006-01-01

The objective of this study is to investigate variations and trends in the global solar radiation in Klang Valley region. The least square method was used for the trend analysis. Since the available time series covers 27 years, linear regression was preferred for the trend analysis. The linear trend is used mainly to test the change in solar radiation and to set limits on the rate of change. Trend line and values and significance levels of the slopes have been found. The seasonal and the annual average values were computed from the monthly average radiation data. The seasonal and annual average solar radiation values were designated as dependent variables, and thus, were fitted linearly for season and annual means for each station. The results showed that the mean of maximum incoming global radiation in Sepember with a value of 21.1 MJ m-2 at Petaling Jaya, while the mean minimum in November and December with values of 10.7 and 10.9 MJ m-2 at Petaling Jaya. The low amounts of solar radiation received in November and December are due to greater cloudiness during the period coinciding with the northeast monsoon season. On rainy days, very little global solar radiation received in November and December are due to greater cloudiness during the period coinciding with the northeast monsoon season. On rainy days, very little global solar radiation is received. The distribution of the seasonal mean values of solar radiation exhibits a high symmetry. Inter-monsoon seasons (April-May) and (October-November) show a similar behavior, just like the northeast monsoon season. The overall average rate of change in global solar radiation during 1975-2002 and 1977-2000 is represented by the slope of the linear regression was small (-0.126 and -0.314 MJ m-2 per year for Subang Airport and Petaling Jaya respectively)

Radiation effects of high and low doses

International Nuclear Information System (INIS)

El-Naggar, A.M.

1998-01-01

The extensive proliferation of the uses and applications of atomic and nuclear energy resulted in possible repercussions on human health. The prominent features of the health hazards that may be incurred after exposure to high and low radiation doses are discussed. The physical and biological factors involved in the sequential development of radiation health effects and the different cellular responses to radiation injury are considered. The main criteria and features of radiation effects of high and low doses are comprehensively outlined

Infrared spectroscopy by use of synchrotron radiation

International Nuclear Information System (INIS)

Nanba, Takao

1991-01-01

During five years since the author wrote the paper on the utilization of synchrotron radiation in long wavelength region, it seems to be recognized that in synchrotron radiation, the light from infrared to milli wave can be utilized, and is considerably useful. Recently the research on coherent synchrotron radiation in this region using electron linac has been developed by Tohoku University group, and the high capability of synchrotron radiation as light source is verified. This paper is the report on the infrared spectroscopic research using incoherent synchrotron radiation obtained from the deflection electromagnet part of electron storage rings. Synchrotron radiation is high luminance white light source including from X-ray to micro wave. The example of research that the author carried out at UVSOR is reported, and the perspective in near future is mentioned. Synchrotron radiation as the light source for infrared spectroscopy, the intensity and dimensions of the light source, far infrared region and mid infrared region, far infrared high pressure spectroscopic experiment, and the heightening of luminance of synchrotron radiation as infrared light source are described. (K.I.)

Effect of radiation heat transfer on the performance of high temperature heat exchanger, (2)

International Nuclear Information System (INIS)

Yamada, Yukio; Mori, Yasuo; Hijikata, Kunio.

1977-01-01

In high temperature helium gas-cooled reactors, the nuclear energy can be utilized effectively, and the safety is excellent as compared with conventional reactors. They are advantageous also in view of environmental problems. In this report, the high temperature heat exchanger used for heating steam with the helium from a high temperature gas reactor is modeled, and the case that radiating gas flow between parallel plates is considered. Analysis was made on the case of one channel and constant heat flux and on the model for a counter-flow type heat exchanger with two channels, and the effect of radiation on the heat transfer in laminar flow and turbulent flow regions was clarified theoretically. The basic equations, the method of approximate solution and the results of calculation are explained. When one dimensional radiation was considered, the representative temperature Tr regarding fluid radiation was introduced, and its relation to mean mixing temperature Tm was determined. It was clarified that the large error in the result did not arise even if Tr was taken equally to Tm, especially in case of turbulent flow. The error was practically negligible when the rate of forced convection heat transfer in case of radiating medium flow was taken same as that in the case without radiation. (Kako, I.)

High energy radiation in cancer treatment

Energy Technology Data Exchange (ETDEWEB)

NONE

1959-10-15

Certain basic recommendations on the use of supervoltage radiation and radioisotope teletherapy in the treatment of malignant growths have been made by an expert study group which met in Vienna in August this y ear. The group, convened jointly by the International Atomic Energy Agency and the World Health Organization, was composed of 20 radiotherapists and radiation physicists from 12 countries. High energy radiation, used in the treatment of malignant tumours, can be either in the form of gamma- or X-rays or in the form of beams of accelerated electrons. The source of radiation is kept at a certain distance from the patient. The study group was agreed on the value of supervoltage radiotherapy, including gamma-ray and high voltage x-ray therapy as well as electron beam therapy. The required gamma radiation can be obtained from large sources of radioactive materials like cobalt 60 or caesium 137, while electron beams are produced by high voltage accelerators. The experts considered the sources in four broad categories: large supervoltage units, intermediate units, small isotope units and units of electron beams or very high energy x-rays. Each group of source was described including its usage. The experts made it clear that while supervoltage radiation should be a part of an organized radiotherapy department, the radiation facilities at any particular establishment should not be of the supervoltage type alone. The high energy facilities could be fruitfully used only when there was a background of general radiotherapy. The group emphasized that supervoltage radiotherapy, in common with other forms of radiotherapy, should be conducted only by adequately trained and qualified personnel, including radiation physicists, and specified the training and qualifications required of such personnel. It was felt that specialized training was one of the main requirements at the present stage and the training programmes of IAEA and WHO should be utilized extensively for this

High energy radiation in cancer treatment

International Nuclear Information System (INIS)

1959-01-01

Certain basic recommendations on the use of supervoltage radiation and radioisotope teletherapy in the treatment of malignant growths have been made by an expert study group which met in Vienna in August this y ear. The group, convened jointly by the International Atomic Energy Agency and the World Health Organization, was composed of 20 radiotherapists and radiation physicists from 12 countries. High energy radiation, used in the treatment of malignant tumours, can be either in the form of gamma- or X-rays or in the form of beams of accelerated electrons. The source of radiation is kept at a certain distance from the patient. The study group was agreed on the value of supervoltage radiotherapy, including gamma-ray and high voltage x-ray therapy as well as electron beam therapy. The required gamma radiation can be obtained from large sources of radioactive materials like cobalt 60 or caesium 137, while electron beams are produced by high voltage accelerators. The experts considered the sources in four broad categories: large supervoltage units, intermediate units, small isotope units and units of electron beams or very high energy x-rays. Each group of source was described including its usage. The experts made it clear that while supervoltage radiation should be a part of an organized radiotherapy department, the radiation facilities at any particular establishment should not be of the supervoltage type alone. The high energy facilities could be fruitfully used only when there was a background of general radiotherapy. The group emphasized that supervoltage radiotherapy, in common with other forms of radiotherapy, should be conducted only by adequately trained and qualified personnel, including radiation physicists, and specified the training and qualifications required of such personnel. It was felt that specialized training was one of the main requirements at the present stage and the training programmes of IAEA and WHO should be utilized extensively for this

Quantification of regional radiative impacts and climate effects of tropical fire aerosols

Science.gov (United States)

Tosca, M. G.; Zender, C. S.; Randerson, J. T.

2011-12-01

Regionally expansive smoke clouds originating from deforestation fires in Indonesia can modify local precipitation patterns via direct aerosol scattering and absorption of solar radiation (Tosca et al., 2010). Here we quantify the regional climate impacts of fire aerosols for three tropical burning regions that together account for about 70% of global annual fire emissions. We use the Community Atmosphere Model, version 5 (CAM5) coupled to a slab ocean model (SOM) embedded within the Community Earth System Model (CESM). In addition to direct aerosol radiative effects, CAM5 also quantifies indirect, semi-direct and cloud microphysical aerosol effects. Climate impacts are determined using regionally adjusted emissions data that produce realistic aerosol optical depths in CAM5. We first analyzed a single 12-year transient simulation (1996-2007) forced with unadjusted emissions estimates from the Global Fire Emissions Database, version 3 (GFEDv3) and compared the resulting aerosol optical depths (AODs) for 4 different burning regions (equatorial Asia, southern Africa, South America and boreal North America) to observed MISR and MODIS AODs for the same period. Based on this analysis we adjusted emissions for each burning region between 150 and 300% and forced a second simulation with the regionally adjusted emissions. Improved AODs from this simulation are compared to AERONET observations available at 15 stations throughout the tropics. We present here two transient simulations--one with the adjusted fire emissions and one without fires--to quantify the cumulative fire aerosol climate impact for three major tropical burning regions (equatorial Asia, southern Africa and South America). Specifically, we quantify smoke effects on radiation, precipitation, and temperature. References Tosca, M.G., J.T. Randerson, C.S. Zender, M.G. Flanner and P.J. Rasch (2010), Do biomass burning aerosols intensify drought in equatorial Asia during El Nino?, Atmos. Chem. Phys., 10, 3515

Early and long-term effects of low- and high-LET radiation on rat behavior and monoamine metabolism in different brain regions

Science.gov (United States)

Belov, Oleg

Space radiation is one of the factors representing a significant health risk to the astronauts during deep-space missions. A most harmful component of space radiation beyond the Earth's magnetosphere is the galactic cosmic rays which are composed of high-energy protons, α particles, and high charge and energy (HZE) nuclei. Recent studies performed at particle accelerators have revealed a significant impact of HZE nuclei on the central nervous system and, in particular, on the cognitive functions. However the exact molecular mechanisms behind the observed impairments remain mostly unclear. This research is focused on study of early and long-term effects of low- and high-linear-energy-transfer (LET) radiation on the rat behavior and monoamine metabolism in the brain regions involved in behavior and motor control and form emotional and motivational states. Different groups of rats were whole-body exposed to 500 MeV/u (12) C particles (LET 10.6 keV/µm) available at the Nuclotron accelerator of the Joint Institute for Nuclear Research (Dubna, Russia) and to gamma rays at the equivalent dose of 1 Gy. An additional group of animals was sham-irradiated and considered as a control. The isolated brain regions have included the prefrontal cortex, nucleus accumbens, hypothalamus, hippocampus, and striatum where we determined the concentrations of noradrenalin, dopamine and its metabolites 3,4-doxyphenylacetic acid, homovanillic acid, and 3-methoxytyramine and serotonin and its metabolite 5-hydroxyindoleacetic acid. The following effects were observed in the different periods after irradiation. 1 day after exposure to (12) C particles strong changes in the concentration of monoamines and their metabolites were observed in three structures, namely, the prefrontal cortex, nucleus accumbens, and hippocampus. However, significant changes were found in the prefrontal cortex and weaker changes were seen in the nucleus accumbens, whereas changes were insignificant in the hippocampus

Characteristics of Smith-Purcell radiation in millimeter wavelength region

International Nuclear Information System (INIS)

Naumenko, G A; Potylitsyn, A P; Sukhikh, L G; Shevelev, M V; Popov, Yu; Karataev, P; Bleko, V

2016-01-01

Investigations of the Smith-Purcell radiation (SPR) were began with non-relativistic electron beams with some unexpected experimental results. Further the experimental investigations were performed with relativistic electron beams for application to beam diagnostics. Large discrepancy between different theoretical models significantly increases the role of experimental studies of this phenomenon. In this report we present some problems and features of experimental investigations of SPR in millimeter wavelength region. The problems of prewave zone and coherent effects are considered. The shadowing effect, focusing of radiation using a parabolic SPR target and effect of inclination of target strips were investigated with moderately relativistic electron beam. (paper)

Emulsion polymerization with high energy radiation

International Nuclear Information System (INIS)

Stannett, V.T.; Stahel, E.P.

1992-01-01

High energy radiation, particularly that of cobalt-60 or caesium-137 gamma-rays, provides in principle an ideal initiator for emulsion polymerization. The high free radical yields from the radiolysis of the aqueous phase combined with the high kinetic chain lengths associated with emulsion polymerization lead to a highly effective utilization of the radiation. There are other important advantages compared with the use of chemical initiators such as potassium persulfate. These are outlined in the chapter, together with some attendant disadvantages. Radiation-induced initiation is temperature independent, and low temperature polymerizations can be conducted with ease. Monomers that mainly terminate their growing chains by chain transfer to monomer give higher molecular weights at lower temperatures. Industrially, vinyl acetate is an important example of such a monomer, and it has been studied using radiation initiation. Both laboratory and pilot plant studies have been carried out and reported. The results are summarized in this chapter. Styrene is the classical example of a material that under a number of conditions closely obeys the so-called ideal Smith-Ewart kinetics. It has been found that under similar conditions but substituting radiation for potassium persulfate as the initiator, ideal kinetics were closely followed. Most of the conventional and some non-standard vinyl and diene monomers have been studied to some extent with radiation-initiated polymerizations in emulsion. To conserve space however, this chapter presents and discusses the results obtained only with styrene and vinyl acetate, both in laboratory and pilot plant investigations. Other monomers and special situations are referenced either directly or to the other available reviews. (orig.)

ICME-driven sheath regions deplete the outer radiation belt electrons

Science.gov (United States)

Hietala, H.; Kilpua, E. K.; Turner, D. L.

2013-12-01

It is an outstanding question in space weather and solar wind-magnetosphere interaction studies, why some storms result in an increase of the outer radiation belt electron fluxes, while others deplete them or produce no change. One approach to this problem is to look at differences in the storm drivers. Traditionally drivers have been classified to Stream Interaction Regions (SIRs) and Interplanetary Coronal Mass Ejections (ICMEs). However, an 'ICME event' is a complex structure: The core is a magnetic cloud (MC; a clear flux rope structure). If the mass ejection is fast enough, it can drive a shock in front of it. This leads to the formation of a sheath region between the interplanetary shock and the leading edge of the MC. While both the sheath and the MC feature elevated solar wind speed, their other properties are very different. For instance, the sheath region has typically a much higher dynamic pressure than the magnetic cloud. Moreover, the sheath region has a high power in magnetic field and dynamic pressure Ultra Low Frequency (ULF) range fluctuations, while the MC is characterised by an extremely smooth magnetic field. Magnetic clouds have been recognised as important drivers magnetospheric activity since they can comprise long periods of very large southward Interplanetary Magnetic Field (IMF). Nevertheless, previous studies have shown that sheath regions can also act as storm drivers. In this study, we analyse the effects of ICME-driven sheath regions on the relativistic electron fluxes observed by GOES satellites on the geostationary orbit. We perform a superposed epoch analysis of 31 sheath regions from solar cycle 23. Our results show that the sheaths cause an approximately one order of magnitude decrease in the 24h-averaged electron fluxes. Typically the fluxes also stay below the pre-event level for more than two days. Further analysis reveals that the decrease does not depend on, e.g., whether the sheath interval contains predominantly northward

Introducing Subrid-scale Cloud Feedbacks to Radiation for Regional Meteorological and Cllimate Modeling

Science.gov (United States)

Convection systems and associated cloudiness directly influence regional and local radiation budgets, and dynamics and thermodynamics through feedbacks. However, most subgrid-scale convective parameterizations in regional weather and climate models do not consider cumulus cloud ...

A computer simulation model to compute the radiation transfer of mountainous regions

Science.gov (United States)

Li, Yuguang; Zhao, Feng; Song, Rui

2011-11-01

In mountainous regions, the radiometric signal recorded at the sensor depends on a number of factors such as sun angle, atmospheric conditions, surface cover type, and topography. In this paper, a computer simulation model of radiation transfer is designed and evaluated. This model implements the Monte Carlo ray-tracing techniques and is specifically dedicated to the study of light propagation in mountainous regions. The radiative processes between sun light and the objects within the mountainous region are realized by using forward Monte Carlo ray-tracing methods. The performance of the model is evaluated through detailed comparisons with the well-established 3D computer simulation model: RGM (Radiosity-Graphics combined Model) based on the same scenes and identical spectral parameters, which shows good agreements between these two models' results. By using the newly developed computer model, series of typical mountainous scenes are generated to analyze the physical mechanism of mountainous radiation transfer. The results show that the effects of the adjacent slopes are important for deep valleys and they particularly affect shadowed pixels, and the topographic effect needs to be considered in mountainous terrain before accurate inferences from remotely sensed data can be made.

The Evolving Role of Regional Radiation Oncology Societies in Resident Education.

Science.gov (United States)

Mattes, Malcolm D

2015-09-01

The goal of this study is to develop insight into how a regional radiation oncology organization like the New York Roentgen Society (NYRS) can best assist in the education and development of residents. From April to June 2012, an electronic survey was sent to all 41 post-graduate year 2-4 radiation oncology residents in the New York metropolitan area. Questions were formatted using Likert scales (ranging from 1 to 5), and the Friedman and Wilcoxon signed-rank tests were used to compare the mean ratings of each answer option. Surveys were completed by 34 residents (response rate 83 %). The three highest rated features that residents hope to get out of their membership in the NYRS included "networking" (mean 4.21), "career mentoring" (mean 4.18), and "education" (mean 4.15), all of which were rated significantly higher (p networking, career mentoring, and clinical educational content (particularly as it relates to boards review) from their regional radiation oncology society. These findings may be applicable to similar organizations in other cities, as a guide for future programming.

Proceedings of the second Asian regional congress on radiation protection, Manila, Philippines, 5-9 November 1979

International Nuclear Information System (INIS)

1979-01-01

Operational experiences of nuclear facilities, radiation protection in medicine, tritium, radiation dosimetry, environmental radiation monitoring, and country experiences in radiation protection are the topics discussed in forty-two (42) papers contained in this compilation of abstracts presented in the Second Asian Regional Congress on Radiation Protection held in Manila. (ELC)

The IAEA regional cooperative agreement programme (RCA) on enhancement and harmonization of radiation protection in the Asia-Pacific Region (1998-2002)

International Nuclear Information System (INIS)

Cameron, R.F.; Oresegun, M.O.

2000-01-01

The IAEA Regional Cooperative Agreement (RCA) was initiated in 1972, and currently consists of 17 Member States from East Asia and Oceania. These countries are Australia, Bangladesh, China, India, Indonesia, Japan, Korea, Malaysia, Myanmar, Mongolia, New Zealand, Pakistan, Philippines, Singapore, Sri Lanka, Thailand and Vietnam. The RCA is one of three cooperative agreements under the aegis of the IAEA, the other two being for Africa (AFRA) and Latin America (ARCAL). The RCA agreement has been extended five times, as it meets particular needs of the participating countries. The region covered by the RCA comprises nearly half of the world's population and is undergoing a rapid expansion in nuclear power development and in the uses of radiation sources (radioactive materials and irradiating equipment). A number of activities in a wide range of areas of Agency interest are carried out under RCA. The Project to Strengthen Radiation Protection Infrastructures was initiated in 1988, as a five year programme, to offer a regional response to some of the radiation protection issues that were raised following the Chernobyl accident. It was extended into Phase 2 from 1993 to 1998 and has now reached a new phase. The IAEA has a dual role to establish standards in radiation protection and safety and to provide for their application. Since the status of the implementation of radiation safety laws and regulations is variable within the RCA countries, the primary focus has been on providing assistance to member states in the drafting of laws and regulations to ensure that sources are authorized and are properly controlled. A number of accidents worldwide have resulted from inappropriate or a complete lack of regulations on the control of sources. However as countries develop, their needs change and it is important that the RCA project in radiation protection changes with them. Hence the new Phase 3 programme in radiation protection has a mixture of events to strengthen radiation

Development of rubber material for high radiation field

International Nuclear Information System (INIS)

Nakatsukasa, Sadayoshi; Tabasaki, Takeshi; Yoshida, Akihiro; Kadowaki, Yoshito

2013-01-01

Generally flexible polymeric materials exposed to radiation can't be used because they soften or harden remarkably in high radiation environment. Aromatic polymers such as PEEK, PI, and PES are also known as radiation-proof polymeric materials. Aromatic polymers are very hard, they can't be used for products like a packing where flexibility is required. We developed a new vulcanized rubber compound by the use of various additives and polymer blend. This developed rubber compound has a high radiation-proof performance by reaction balance of cross-linking and decomposition in this rubber. This rubber compound has a rubber elasticity even if exposed to radiation of MGy level, and its radiation proof is more than 5 times as high as conventional polymeric materials. This rubber compound is much more flexible than the aromatic polymers which are the used as conventional radiation-proof polymers. (author)

Test and Evaluation of Fiber Optic Sensors for High-Radiation Space Nuclear Power Applications

International Nuclear Information System (INIS)

Klemer, Daniel; Fielder, Robert S.; Stinson-Bagby, Kelly L.

2004-01-01

Fiber optic sensors can be used to measure a number of parameters, including temperature, strain, pressure and flow, for instrumentation and control of space nuclear power systems. In the past, this technology has often been rejected for use in such a high-radiation environment based on early experiments that revealed a number of degradation phenomena, including radiation-induced fiber attenuation, or 'graying', and Fiber Bragg Grating (FBG) fading and wavelength shift. However, this paper reports the results of recent experimental testing that demonstrates readability of fiber optic sensors to extremely high levels of neutron and gamma radiation. Both distributed Fiber Bragg Grating (FBG) sensors and single-point Extrinsic Fabry Perot Interferometer (EFPI) sensors were continuously monitored over a 2-month period, during which they were exposed to combined neutron and gamma radiation in both in-core and ex-core positions within a nuclear reactor. Total exposure reached approximately 2 x 10 19 cm -2 fast neutron (E > 1 MeV) fluence and 8.7 x 10 8 Gy gamma for in-core sensors. FBG sensors were interrogated using a standard Luna Innovations FBG measurement system, which is based on optical frequency-domain reflectometer (OFDR) technology. Approximately 74% of the 19 FBG sensors located at the core centerline in the in-core position exhibited sufficient signal-to-noise ratio (SNR) to remain readable even after receiving the maximum dose. EFPI sensors were spectrally interrogated using a broadband probe source operating in the 830 nm wavelength region. While these single-point sensors failed early in the test, important additional fiber spectral transmission data was collected, which indicates that interrogation of EFPI sensors in alternate wavelength regions may allow significant improvement in sensor longevity for operation in high-radiation environments. This work was funded through a Small Business Innovative Research (SBIR) contract with the Nasa Glenn Research

EFFECTS OF SPIN ON HIGH-ENERGY RADIATION FROM ACCRETING BLACK HOLES

Energy Technology Data Exchange (ETDEWEB)

O’ Riordan, Michael; Pe’er, Asaf [Physics Department, University College Cork, Cork (Ireland); McKinney, Jonathan C., E-mail: michael_oriordan@umail.ucc.ie [Department of Physics and Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States)

2016-11-01

Observations of jets in X-ray binaries show a correlation between radio power and black hole spin. This correlation, if confirmed, points toward the idea that relativistic jets may be powered by the rotational energy of black holes. In order to examine this further, we perform general relativistic radiative transport calculations on magnetically arrested accretion flows, which are known to produce powerful jets via the Blandford–Znajek (BZ) mechanism. We find that the X-ray and γ -ray emission strongly depend on spin and inclination angle. Surprisingly, the high-energy power does not show the same dependence on spin as the BZ jet power, but instead can be understood as a redshift effect. In particular, photons observed perpendicular to the spin axis suffer little net redshift until originating from close to the horizon. Such observers see deeper into the hot, dense, highly magnetized inner disk region. This effect is largest for rapidly rotating black holes due to a combination of frame dragging and decreasing horizon radius. While the X-ray emission is dominated by the near horizon region, the near-infrared (NIR) radiation originates at larger radii. Therefore, the ratio of X-ray to NIR power is an observational signature of black hole spin.

Genetic and oncological consequences of chemical and radiation pollution of the Kuzbass and Altai regions

International Nuclear Information System (INIS)

Ilyinskikh, E.N.; Kozlova, S.V.; Ilyinskikh, N.N.; Ilyinskikh, I.N.

2005-01-01

The paper presents assessment of frequencies of micronucleated lymphocytes in 12307 individuals living in 7 towns in the south part of the Kuzbass and Altai regions. Among the towns the majority of individuals with significantly high frequencies of micronucleated lymphocytes were detected in towns adjacent to the Semipalatinsk Test Site (STS). The pollution of the environment was also caused by the activity of metallurgical plants and coal industry in this region. The most considerable genome instability was found in individuals born during intensive operation of the Site (1949-1962). Moreover, we have determined that residents of the towns located close to STS have significantly high levels of antibodies to potentially oncogenic Epstein-Barr virus. The considerable Epstein-Barr virus contamination among the residents in the radiation polluted zone around the STS was supposed to be caused by immunodeficiency disorders in these individuals and induce high frequencies of micronucleated cells. (author)

Oblique radiation lateral open boundary conditions for a regional climate atmospheric model

Science.gov (United States)

Cabos Narvaez, William; De Frutos Redondo, Jose Antonio; Perez Sanz, Juan Ignacio; Sein, Dmitry

2013-04-01

The prescription of lateral boundary conditions in regional atmospheric models represent a very important issue for limited area models. The ill-posed nature of the open boundary conditions makes it necessary to devise schemes in order to filter spurious wave reflections at boundaries, being desirable to have one boundary condition per variable. On the other side, due to the essentially hyperbolic nature of the equations solved in state of the art atmospheric models, external data is required only for inward boundary fluxes. These circumstances make radiation lateral boundary conditions a good choice for the filtering of spurious wave reflections. Here we apply the adaptive oblique radiation modification proposed by Mikoyada and Roseti to each of the prognostic variables of the REMO regional atmospheric model and compare it to the more common normal radiation condition used in REMO. In the proposed scheme, special attention is paid to the estimation of the radiation phase speed, essential to detecting the direction of boundary fluxes. One of the differences with the classical scheme is that in case of outward propagation, the adaptive nudging imposed in the boundaries allows to minimize under and over specifications problems, adequately incorporating the external information.

Sensitivity of mesoscale modeling of smoke direct radiative effect to the emission inventory: a case study in northern sub-Saharan African region

International Nuclear Information System (INIS)

Zhang, Feng; Wang, Jun; Yang, Zhifeng; Ge, Cui; Ichoku, Charles; Hyer, Edward J; Da Silva, Arlindo; Su, Shenjian; Zhang, Xiaoyang; Kondragunta, Shobha; Kaiser, Johannes W; Wiedinmyer, Christine

2014-01-01

An ensemble approach is used to examine the sensitivity of smoke loading and smoke direct radiative effect in the atmosphere to uncertainties in smoke emission estimates. Seven different fire emission inventories are applied independently to WRF-Chem model (v3.5) with the same model configuration (excluding dust and other emission sources) over the northern sub-Saharan African (NSSA) biomass-burning region. Results for November and February 2010 are analyzed, respectively representing the start and end of the biomass burning season in the study region. For February 2010, estimates of total smoke emission vary by a factor of 12, but only differences by factors of 7 or less are found in the simulated regional (15°W–42°E, 13°S–17°N) and monthly averages of column PM 2.5 loading, surface PM 2.5 concentration, aerosol optical depth (AOD), smoke radiative forcing at the top-of-atmosphere and at the surface, and air temperature at 2 m and at 700 hPa. The smaller differences in these simulated variables may reflect the atmospheric diffusion and deposition effects to dampen the large difference in smoke emissions that are highly concentrated in areas much smaller than the regional domain of the study. Indeed, at the local scale, large differences (up to a factor of 33) persist in simulated smoke-related variables and radiative effects including semi-direct effect. Similar results are also found for November 2010, despite differences in meteorology and fire activity. Hence, biomass burning emission uncertainties have a large influence on the reliability of model simulations of atmospheric aerosol loading, transport, and radiative impacts, and this influence is largest at local and hourly-to-daily scales. Accurate quantification of smoke effects on regional climate and air quality requires further reduction of emission uncertainties, particularly for regions of high fire concentrations such as NSSA. (paper)

Development of radiation-resisting high molecular-weight materials

International Nuclear Information System (INIS)

Nakagawa, Tsutomu

1976-01-01

The excellent radiation-resisting polyvinyl chloride developed at the opportunity of the research on the relationships between the protection of living body and the polymer-technological protection from radiation is reviewed. The report is divided into four main parts, namely 1) the change in the molecular arrangement of market-available, high molecular-weight materials by gamma-ray irradiation, 2) the protection of high molecular-weight materials from radiation, 3) the relationships between the biological radiation-protective substances and the change to radiation-resisting property of synthesized high molecular-weight substances, and 4) the development of the radiation-resisting high molecular-weight materials as metal-collecting agents. Attention is paid to the polyvinyl chloride having N-methyl-dithio-carbamate radical (PMD), synthesized by the author et. al., that has excellent radiation-resisting property. PMD has some possibility to form thiol- and amino-radicals necessary to protect living things from radiation. It is believed that the protection effects of N-methyl-dithio-carbamate radical are caused by the relatively stable S radical produced by the energy transfer. PMD film is suitable for the irradiation of foods, because it hardly changes the permeability of oxygen and carbon dioxide. PMD produces mercaptide or chelate. A new metal-collecting agent (PSDC) having reactivity with the metallic ions with radiation-resisting property was developed, which is derived from polyvinyl chloride and sodium N-methyl-N-carboxy-methyl-dithio-carbamate. (Iwakiri, K.)

Regional economic development programs related to the registration systems for the health records of radiation workers

International Nuclear Information System (INIS)

Nakagawa, Haruo; Kanda, Keiji

2000-01-01

The two policies, 'Promotion of Health Care for Elderly Person' and Completion of Health Care System' are important for regional economic development. If we apply the Health Records Registration Systems for Radiation Workers to the Regional Health Care System, we can get a more effective plan for regional economic development. In Japan, most of the electric power companies depend on radiation works to the external labor. As the chance of employment usually depends on the time and the period of outage of nuclear power stations, the employment of radiation works lacks its stability. From the analysis on the mobility of radiation workers, we can see the stability of employment increases in proportion to the number of reactors. This paper proposes the need for such a registration system to be granted under three laws governing special accounts for power supply municipalities and to set up the system within regional medical information systems. It also proposes the founding of an Overall Health Insurance Cooperative, managed by contractors safety union in the municipalities as soon as the condition of founding, 3, 000 people, is satisfied. (author)

Radiation dozes reconstruction of Semipalatinsk region Beskaragai area's population by the method of biological measure

International Nuclear Information System (INIS)

Bigaliev, A.; Kundakbaeva, G.; Bigalieva, R.

2001-01-01

Full text: The study of radiation situation (on the position of May 1989) in Beskaragai area of Semipalatinsk region showed that the level of γ-radiation on it's territory reached 13-20 μR/hour, which was determined by the traces of long living radionuclides. In the inhabited regions of Dolon, Kanonerka, Buras, Ramadan villages the effect of deepening was noticed, α-particle's density level has reached maximum on the depth of approximately 10 cm, and further it decreases up to the 30 cm depth, This circumstance witnesses about the fact that we are talking about radioactive traces of many years ago happening with a time going to the depth from the upper coverage of soil. We've made the evaluation of radiation influence's genetic effects on the man's population. Cytogenetic analysis (with the use of G-method of chromosome's coloring) at whole in Beskaragai region shows that the frequency of aberrations for the cell among the inhabitants of the region is obviously higher 3.3 times at average in the region than among the population of the controlled area. During the study of the cytogenetic effects of increased radiation level's influence it is important first of all to determine the frequency of chromosome type aberrations - dicentric chromosomes, centric circles, acentric pair fragments. As it is known, the level of chromosome type aberrations is sufficiently well correlated with the doze, We have determined accumulative doze of radiation using the formula (D.C. Lloyd at all. 1992) for the calculation of dicentrics under the chronical influence of the small dozes of ionized radiation. According to the made calculations the oriented reconstruction of radiation dozes in Beskaragai region made 11 ber = 0.11 Sv, for the Dolon village - 14 ber, Kanonerka village - 13 ber, Buras village - 6 ber, Ramadan - 9.5 ber. Presented data allows to ask the question about the more spread use of cytogenetic method of research among the different population's categories living at

Environmental radiation monitoring results for the period 1989-1999 in NAPS region using TLDs

International Nuclear Information System (INIS)

Basu, A.S.; Chougaonkar, M.P.; Mayya, Y.S.; Sadasivan, S.; Sharma, L.N.

2001-06-01

In this report, we present the results of environmental gamma radiation levels monitored around NAPS region using TLDs. The report gives quarterly environmental radiation monitoring data obtained during the period 1989-'99; i.e. during the operating phase of the reactor. Twenty eight TLD locations were selected within a radius of twenty six km. of which six were within the exclusion zone (radius 1.6 km). The mean gamma radiation level within the exclusion zone has been evaluated as 111 ± 6.6 mR/year and that for locations beyond the exclusion zone as 140 ± 14 mR/year. As these values are well within the corresponding pre-operational general background value of 142 ± 30 mR/year (Basu et. al 1989), it is concluded that the reactor operations have not contributed to any increase in the gamma radiation levels in the environs of the NAPS region. (author)

Statistical theory for estimating sampling errors of regional radiation averages based on satellite measurements

Science.gov (United States)

Smith, G. L.; Bess, T. D.; Minnis, P.

1983-01-01

The processes which determine the weather and climate are driven by the radiation received by the earth and the radiation subsequently emitted. A knowledge of the absorbed and emitted components of radiation is thus fundamental for the study of these processes. In connection with the desire to improve the quality of long-range forecasting, NASA is developing the Earth Radiation Budget Experiment (ERBE), consisting of a three-channel scanning radiometer and a package of nonscanning radiometers. A set of these instruments is to be flown on both the NOAA-F and NOAA-G spacecraft, in sun-synchronous orbits, and on an Earth Radiation Budget Satellite. The purpose of the scanning radiometer is to obtain measurements from which the average reflected solar radiant exitance and the average earth-emitted radiant exitance at a reference level can be established. The estimate of regional average exitance obtained will not exactly equal the true value of the regional average exitance, but will differ due to spatial sampling. A method is presented for evaluating this spatial sampling error.

Mercury-free high pressure discharge lamps dominated by molecular radiation

International Nuclear Information System (INIS)

Kaening, M; Hitzschke, L; Berger, M; Schalk, B; Franke, St; Methling, R

2011-01-01

High intensity discharge (HID) lamps dominated by molecular radiation offer a very promising alternative for use in future light sources. They are able to deliver competitive efficacies of about 110 lm W -1 and higher, excellent colour rendering index above 90 and a correlated colour temperature in the 3000-4000 K region at the operating point near the Planckian locus. Moreover, these lamps are opening up the possibility of dimming. Due to the fact that they are able to omit mercury they are environmentally friendly. The emission spectra generated by these HID lamps differ significantly from those of conventional lamps. The reason for this is the dominance of molecular radiation processes. In comparison with conventional HID lamps atomic contributions are usually rather small. In the present case they amount to less than about 10% of the total intensity in the visible range.

Mercury-free high pressure discharge lamps dominated by molecular radiation

Energy Technology Data Exchange (ETDEWEB)

Kaening, M; Hitzschke, L; Berger, M [Research Europe, OSRAM GmbH, Werner-von-Siemens Strasse 6, 86159 Augsburg (Germany); Schalk, B [Vitec Group Videocom Division, Erfurter Strasse 16, 85386 Eching (Germany); Franke, St; Methling, R, E-mail: m.kaening@osram.de [INP, Leibniz-Institut fuer Plasmaforschung und Technologie e. V., Felix-Hausdorff-Strasse 2, 17489 Greifswald (Germany)

2011-06-08

High intensity discharge (HID) lamps dominated by molecular radiation offer a very promising alternative for use in future light sources. They are able to deliver competitive efficacies of about 110 lm W{sup -1} and higher, excellent colour rendering index above 90 and a correlated colour temperature in the 3000-4000 K region at the operating point near the Planckian locus. Moreover, these lamps are opening up the possibility of dimming. Due to the fact that they are able to omit mercury they are environmentally friendly. The emission spectra generated by these HID lamps differ significantly from those of conventional lamps. The reason for this is the dominance of molecular radiation processes. In comparison with conventional HID lamps atomic contributions are usually rather small. In the present case they amount to less than about 10% of the total intensity in the visible range.

Radiation Therapy for Loco-Regional Recurrence of Adenocarcinoma of the Rectum

International Nuclear Information System (INIS)

Cho, K. H.; Seong, J. S.; Suh, C. O.; Kim, G. E.

1984-01-01

Thirty patients with loco-regional recurrence following curative surgery for adenocarcinoma of the rectum were retrospectively. Evaluated to determine factors influencing survival and the efficacy of radiation therapy. In this review of 30 patients undergoing radiation therapy, more than 50 percent (17/30) had definite symptomatic and objective response. Ninety percent of patients (27/30) received significant palliation. Over all 2-year survival rate was 7.4% and their median was 13.0 months. Grade of response and Sex were statistically related to survival

Biomarkers specific to densely-ionising (high LET) radiations

International Nuclear Information System (INIS)

Brenner, D.J.; Okladnikova, N.; Hande, P.; Burak, L.; Geard, C.R.; Azizova, T.

2001-01-01

There have been several suggestions of biomarkers that are specific to high LET radiation. Such a biomarker could significantly increase the power of epidemiological studies of individuals exposed to densely-ionising radiations such as alpha particles (e.g. radon, plutonium workers, individuals exposed to depleted uranium) or neutrons (e.g. radiation workers, airline personnel). We discuss here a potentially powerful high LET biomarker (the H value) which is the ratio of induced inter-chromosomal aberrations to intra-arm aberrations. Both theoretical and experimental studies have suggested that this ratio should differ by a factor of about three between high LET radiation and any other likely clastogen, and will yield more discrimination than the previously suggested F value (ratio of inter-chromosomal aberrations to intra-chromosomal inter-arm aberrations). Evidence of the long-term stability of such chromosomal biomarkers has also been generated. Because these stable intra-arm and inter-chromosomal aberrations are (1) frequent and (2) measurable at long times after exposure, this H value appears to be a practical biomarker of high LET exposure, and several in vitro studies have confirmed the approach for unstable aberrations. The approach is currently being tested in a population of Russian radiation workers exposed several decades ago to high- or low LET radiation. (author)

WE-G-BRD-07: Investigation of Distal Lung Atelectasis Following Stereotactic Body Radiation Therapy Using Regional Lung Volume Changes Between Pre- and Post- Treatment CT Scans

Energy Technology Data Exchange (ETDEWEB)

Diot, Q; Kavanagh, B; Miften, M [University of Colorado School of Medicine, Aurora, CO (United States)

2014-06-15

Purpose: To propose a quantitative method using lung deformations to differentiate between radiation-induced fibrosis and potential airway stenosis with distal atelectasis in patients treated with stereotactic body radiation therapy (SBRT) for lung tumors. Methods: Twenty-four lung patients with large radiation-induced density increases outside the high dose region had their pre- and post-treatment CT scans manually registered. They received SBRT treatments at our institution between 2002 and 2009 in 3 or 5 fractions, to a median total dose of 54Gy (range, 30–60). At least 50 anatomical landmarks inside the lung (airway branches) were paired for the pre- and post-treatment scans to guide the deformable registration of the lung structure, which was then interpolated to the whole lung using splines. Local volume changes between the planning and follow-up scans were calculated using the deformation field Jacobian. Hyperdense regions were classified as atelectatic or fibrotic based on correlations between regional density increases and significant volume contractions compared to the surrounding tissues. Results: Out of 24 patients, only 7 demonstrated a volume contraction that was at least one σ larger than the remaining lung average. Because they did not receive high doses, these shrunk hyperdense regions were likely showing distal atelectasis resulting from radiation-induced airway stenosis rather than conventional fibrosis. On average, the hyperdense regions extended 9.2 cm farther than the GTV contours but not significantly more than 8.6 cm for the other patients (p>0.05), indicating that a large offset between the radiation and hyperdense region centers is not a good surrogate for atelectasis. Conclusion: A method based on the relative comparison of volume changes between different dates was developed to identify potential lung regions experiencing distal atelectasis. Such a tool is essential to study which lung structures need to be avoided to prevent

Contrails and their impact on shortwave radiation and photovoltaic power production – a regional model study

Directory of Open Access Journals (Sweden)

S. Gruber

2018-05-01

Full Text Available A high-resolution regional-scale numerical model was extended by a parameterization that allows for both the generation and the life cycle of contrails and contrail cirrus to be calculated. The life cycle of contrails and contrail cirrus is described by a two-moment cloud microphysical scheme that was extended by a separate contrail ice class for a better representation of the high concentration of small ice crystals that occur in contrails. The basic input data set contains the spatially and temporally highly resolved flight trajectories over Central Europe derived from real-time data. The parameterization provides aircraft-dependent source terms for contrail ice mass and number. A case study was performed to investigate the influence of contrails and contrail cirrus on the shortwave radiative fluxes at the earth's surface. Accounting for contrails produced by aircraft enabled the model to simulate high clouds that were otherwise missing on this day. The effect of these extra clouds was to reduce the incoming shortwave radiation at the surface as well as the production of photovoltaic power by up to 10 %.

Experimental studies and modelling of high radiation and high density plasmas in the ASDEX upgrade tokamak

Energy Technology Data Exchange (ETDEWEB)

Casali, Livia

2015-11-24

establish an the radiation increases in this region. To account for these effects, an empirical non-coronal model was developed which takes the impurity residence time at the pedestal into account. The validity of this assumption was verified by modelling the evolution of the impurities and radiation for ASDEX Upgrade H-modes with nitrogen seeding by coupling the ASTRA transport code with STRAHL. The time-dependent simulations include impurity radiation due to nitrogen and tungsten and the transport effects induced at the edge by the ELMs. The modelling results have been validated against the experimental data. The modelled radiation profiles show a very good agreement with the measured ones over both radius and time. In particular, the strong enhancement of the nitrogen radiation caused by non-coronal effects through the ELM-induced transport is well reproduced. The radiation properties of tungsten are very weakly influenced by non-coronal effects due to the faster equilibration. W radiation, which is highly dependent on the f{sub ELM}, strongly increases when f{sub ELM} is decreased, due to the lack of sufficiently strong flush out of this impurity. This is in agreement with the experimental observations and indicates that maintaining high ELM frequency is essential for the stability and performance of the discharges. Analyses of the high density scenario with pellets indicate that several processes take place when pellets are injected into the plasma. In particular, due to their cooling effect, the temperature drops as soon as pellets are injected. This is compensated by an increase in density. These processes occur mainly at the edge and are propagated to the core via stiffness. This explains why the confinement stays approximately constant during the whole discharge. Both experiments and transport calculations reveal that the energy confinement time is independent of the density indicating that the currently used scaling is not valid in this regime. The results of this

Biological effects of high-energy radiation

International Nuclear Information System (INIS)

Curtis, S.B.

1976-01-01

The biological effects of high-energy radiation are reviewed, with emphasis on the effects of the hadronic component. Proton and helium ion effects are similar to those of the more conventional and sparsely ionizing x- and γ-radiation. Heavy-ions are known to be more biologically effective, but the long term hazard from accumulated damage has yet to be assessed. Some evidence of widely varying but dramatically increased effectiveness of very high-energy (approximately 70 GeV) hadron beams is reviewed. Finally, the importance of the neutron component in many situations around high-energy accelerators is pointed out

The potential of global solar radiation in the Silesia region as a renewable source of energy

Directory of Open Access Journals (Sweden)

Waniek Katarzyna

2016-12-01

Full Text Available Historically, Silesia has been at the centre of the Polish coal industry for many years and thus has experienced poorer air quality compared to other voivodeships. However, in recent years strong economic transformation in the area has led to a considerable reduction in coal production. This study aimed to assess the variability of global solar radiation at selected stations within the Silesian voivodeship, in order to re-evaluate the resources of renewable solar energy during the period 1994–2013. The theoretical potential of solar radiation was calculated based on a three-dimensional terrain model. The data on global solar radiation from 13 stations within the Silesia region, covering the period 1994–2013, were obtained from the Regional Inspectorate of Environmental Protection in Katowice. The most favourable conditions for the use of solar energy were found at the cities Sosnowiec and Cieszyn. The largest increase in global radiation over the research period was observed in Zabrze. The average annual global radiation ranged between 600–1300 kWh·m−2. Digital Elevation Models (DEM for selected districts of the Silesia region were used to calculate the theoretical potential of global solar radiation. The highest theoretical potential of global radiation was found in the district of Cieszyn, located at the highest altitude.

Physiological and genetics studies of highly radiation-resistant bacteria

International Nuclear Information System (INIS)

Keller, L.C.

1981-01-01

The phenomenon of radiation resistance was studied using micrococci and Moraxella-Acinetobacter capable of surviving very high doses of gamma radiation which were isolated from foods. Physiological age, or growth phase, was found to be an important factor in making comparisons of radiation-resistance among different bacteria and their mutants. Radiation-resistant bacteria were highly resistant to the lethal effect of nitrosoguanidine used for mutagenesis. Studies of relative resistance of radiation-resistant bacteria, radiation-sensitive mutants, and nonradiation-resistant bacteria to killing by different chemical mutagens did not reveal a correlation between the traits of radiation resistance and mutagen resistance among different strains. Comparisons of plasmid profiles of radiation-resistant bacteria and selected radiation-sensitive mutants suggested the possibility that plasmids may carry genes involved in radiation resistance

EPR dosimetry of radiation background in the Urals region

Energy Technology Data Exchange (ETDEWEB)

Shishkina, E.A.; Degteva, M.O.; Shved, V.A. [Urals Research Center for Radiation Medicine, 48-A Vorovsky, Chelyabinsk 454076 (Russian Federation); Fattibene, P.; Onori, S. [Istituto Superiore di Sanita and Istituto Nazionale di Fisica Nucleare (Italy); Wieser, A. [GSF, Forschungszentrum fuer Umwelt und Gesundheit, Ingolstaedter Landstr (Germany); Ivanov, D.V.; Bayankin, S.N. [Institute of Metal Physics, Russian Academy of Sciences (Russian Federation); Knyazev, V.A.; Vasilenko, E.I.; Gorelov, M. [ZAO, Closed Corporation ' Company GEOSPETSECOLOGIA' (Russian Federation)

2006-07-01

Method of Electron Paramagnetic Resonance is extensively applied to individual retrospective dosimetry. The background dose is unavoidable component of cumulative absorbed dose in the tooth enamel accumulated during the lifetime of donor. Estimation of incidental radiation dose using tooth enamel needs in extraction of background dose. Moreover, the variation of background doses in the population is a limited factor for reliable detection of additional irradiation especially for low dose level. Therefore the accurate knowledge of the natural background radiation dose is a critical element of EPR studies of exposed populations. In the Urals region the method applies for such two large cohorts as the workers of Mayak (Ozersk citizens) and Techa River riverside inhabitants (rural population). Current study aimed to investigate the Urals radiation background detected by EPR spectrometry. For this aim two group of unexposed Urals residents were separated, viz: citizens of Ozersk and rural inhabitants of Chelyabinsk region. Comparison of two investigated territories has demonstrated that from the point of view of radiation background it is impossible to assume the Urals population as uniform. The reliable difference between the urban and rural residents has been found. The average background doses of Ozersk donors is in average 50 mGy higher than those detected for rural residents. The individual variability of background doses for Osersk has been higher than in the rural results. The difference in background dose levels between two population results in different limits of accidental dose detection and individualization. The doses for 'Mayak' workers (Ozyorsk citizens) can be classed as anthropogenic if the EPR measurements exceed 120 mGy for teeth younger than 40 years, and 240 mGy for teeth older than 70 years. The anthropogenic doses for Techa River residents (rural population) would be higher than 95 mGy for teeth younger than 50 years and 270 mGy for

EPR dosimetry of radiation background in the Urals region

International Nuclear Information System (INIS)

Shishkina, E.A.; Degteva, M.O.; Shved, V.A.; Fattibene, P.; Onori, S.; Wieser, A.; Ivanov, D.V.; Bayankin, S.N.; Knyazev, V.A.; Vasilenko, E.I.; Gorelov, M.

2006-01-01

Method of Electron Paramagnetic Resonance is extensively applied to individual retrospective dosimetry. The background dose is unavoidable component of cumulative absorbed dose in the tooth enamel accumulated during the lifetime of donor. Estimation of incidental radiation dose using tooth enamel needs in extraction of background dose. Moreover, the variation of background doses in the population is a limited factor for reliable detection of additional irradiation especially for low dose level. Therefore the accurate knowledge of the natural background radiation dose is a critical element of EPR studies of exposed populations. In the Urals region the method applies for such two large cohorts as the workers of Mayak (Ozersk citizens) and Techa River riverside inhabitants (rural population). Current study aimed to investigate the Urals radiation background detected by EPR spectrometry. For this aim two group of unexposed Urals residents were separated, viz: citizens of Ozersk and rural inhabitants of Chelyabinsk region. Comparison of two investigated territories has demonstrated that from the point of view of radiation background it is impossible to assume the Urals population as uniform. The reliable difference between the urban and rural residents has been found. The average background doses of Ozersk donors is in average 50 mGy higher than those detected for rural residents. The individual variability of background doses for Osersk has been higher than in the rural results. The difference in background dose levels between two population results in different limits of accidental dose detection and individualization. The doses for 'Mayak' workers (Ozyorsk citizens) can be classed as anthropogenic if the EPR measurements exceed 120 mGy for teeth younger than 40 years, and 240 mGy for teeth older than 70 years. The anthropogenic doses for Techa River residents (rural population) would be higher than 95 mGy for teeth younger than 50 years and 270 mGy for teeth older

Radiation structurization borosilicates in the region of small dozes

International Nuclear Information System (INIS)

Gadzhieva, N.N.; Melikova, S.Z.

2007-01-01

Full text: Borosilicates are one of perspective materials who are characterized by high thermal and radiating stability. Owing to these properties they are widely applied as constructional materials in reactor technologies. The structural condition of a bor in crystal compounds is characterized by two coordination numbers- three and and four. Change of this condition speaks also original properties borosilicate. Studying influence is actual γ-irradiations in the region of rather small dozes on ability change coordination of a B in borosilicate. In the given work results of IR-spectroscopic researches initial and radiation-structured borosilicates are presented. With this purpose were investigated borosilicates with maintenance B 2 O 3 in SiO 2 equal 0.5; 1; 1.5; 3; 5 and 10 mas.%, received by a method of sedimentation. Samples irradiated γ-quanta on an isotope source 60 Co with capacity of a doze dD γ /dt=0.80 Gy/s. The absorbed doze made D γ ∼0.5-50 kGy. IR-spectra of reflection initial and γ-irradiated tablets borosilicates measured on spectrophotometer Specord 71 IR (Carl Zeiss) at a room temperature. Optical density of the bands corresponding trigonal and tetrahedric - coordination atoms of a bor and their parity at the various mass maintenance of boric anhydride in SiO 2 before and after γ-irradiation. The absorption bands of asymmetric stretching vibration BO 3 and BO 4 groupings in structure of B 2 O 3 /SiO 2 have maxima at ν=1320 (ν as BO 3 ) and 980 cm -1 (ν as BO 4 ). Studying dose has shown dependences D 1320 /D 980 , that in the region of rather small dozes 0.5 γ 1320 /D 980 of optical densities trigonal and tetrahedric coordination a B it is established, that at the contain B 2 O 3 in SiO 2 /B 2 O 3 ∼1.5 mas.% maximal introduction B 3+ in a lattice oxide silicon is observed

High energy radiation effects on the human body

International Nuclear Information System (INIS)

Kato, Kazuaki

1977-01-01

High-energy radiation injuries and their risks were recognized, information on low-energy radiation injuries was also arranged, and with these backgrounds, countermeasures against prevention of radiation injuries were considered. Redintegration of DNA and mutation by radiation were described, and relationship between radiation injuries and dose was considered. Interaction of high-energy radiation and substances in the living body and injuries by the interaction were also considered. Expression method of risk was considered, and a concept of protection dose was suggested. Protection dose is dose equivalent which is worthy of value at the point where the ratio to permissible dose distributed among each part of the body is at its maximum in the distribution of dose equivalent formed within the body when standard human body is placed at a certain radiation field for a certain time. Significance and countermeasures of health examination which is under an abligation to make radiation workers receive health check were thought, and problems were proposed on compensation when radiation injuries should appear actually. (Tsunoda, M.)

Assessment of indoor radiation dose received by the residents of natural high background radiation areas of coastal villages of Kanyakumari district, Tamil Nadu, India

International Nuclear Information System (INIS)

Deva Jayanthi, D.; Maniyan, C.G.; Perumal, S.

2011-01-01

Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv. -- Highlights: → The effective dose received by the villages of Natural High Background Area (NHBRA) such as Enayam, Midalam and Mel Midalam is high when compared with other study areas. → The high dose indicates higher concentration of radioactive nuclides like Thorium and Uranium in the soil. → As radiation is harmful to human life, the external and internal doses can be reduced by removing the monazite content present in the soil by mineral separation. → Contribution from vegetables, fruits, fish and other non vegetarian items are also being examined. → These results along with other socio-economic factors can throw considerable light on the epidemiological impacts due to low levels of chronic exposure.

Assessment of indoor radiation dose received by the residents of natural high background radiation areas of coastal villages of Kanyakumari district, Tamil Nadu, India

Energy Technology Data Exchange (ETDEWEB)

Deva Jayanthi, D., E-mail: d.devajayanthi@gmail.co [Department of Physics, Women' s Christian College, Nagercoil 629001 (India); Maniyan, C.G. [Environmental Assessment Division, BARC, Mumbai 400085 (India); Perumal, S. [Department of Physics and Research Centre, S.T.Hindu College, Nagercoil 629002 (India)

2011-07-15

Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv. -- Highlights: {yields} The effective dose received by the villages of Natural High Background Area (NHBRA) such as Enayam, Midalam and Mel Midalam is high when compared with other study areas. {yields} The high dose indicates higher concentration of radioactive nuclides like Thorium and Uranium in the soil. {yields} As radiation is harmful to human life, the external and internal doses can be reduced by removing the monazite content present in the soil by mineral separation. {yields} Contribution from vegetables, fruits, fish and other non vegetarian items are also being examined. {yields} These results along with other socio-economic factors can throw considerable light on the epidemiological impacts due to low levels of chronic exposure.

THE HIGH BACKGROUND RADIATION AREA IN RAMSAR IRAN: GEOLOGY, NORM, BIOLOGY, LNT, AND POSSIBLE REGULATORY FUN

Energy Technology Data Exchange (ETDEWEB)

Karam, P. A.

2002-02-25

The city of Ramsar Iran hosts some of the highest natural radiation levels on earth, and over 2000 people are exposed to radiation doses ranging from 1 to 26 rem per year. Curiously, inhabitants of this region seem to have no greater incidence of cancer than those in neighboring areas of normal background radiation levels, and preliminary studies suggest their blood cells experience fewer induced chromosomal abnormalities when exposed to 150 rem ''challenge'' doses of radiation than do the blood cells of their neighbors. This paper will briefly describe the unique geology that gives Ramsar its extraordinarily high background radiation levels. It will then summarize the studies performed to date and will conclude by suggesting ways to incorporate these findings (if they are borne out by further testing) into future radiation protection standards.

Cytogenetic investigation in a population living in the high background radiation area in China

Energy Technology Data Exchange (ETDEWEB)

Deqing, C.

1980-04-01

On the basis of the previous investigation, 24,000 metaphases of the lymphocytes of 120 inhabitants from Tongyou region, where the highest individual cummulative exposure per year of 372 mR in weighted average was recorded in the high background radiation area selected, have been analysed with the method recommended by WHO in 1973, in order to determine the extent of human chromosome aberrations induced by the high background radiation of various levels. The results show that the difference between the total number of chromosome breakages in the individuals living in the high background radiation area and that in the control area (0.32x10/sup -2/ and 0.27x10/sup -2/ per cell respectively) is not significant whereas that between the numbers of two-hite aberrations (mainly dicentric) in the same two groups (0.042x10/sup -2/ and 0.0048x10/sup -2/ per cell) is significant (X/sup 2/ = 6.1475, P<0.05). In addition, the normal value of the chromosome aberrations of human lymphocytes was analyzed.

Semiconductor high-energy radiation scintillation detector

International Nuclear Information System (INIS)

Kastalsky, A.; Luryi, S.; Spivak, B.

2006-01-01

We propose a new scintillation-type detector in which high-energy radiation generates electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. An important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombination time of minority carriers. Notably, the fast response comes without any degradation in brightness. When the scintillator is implemented in a qualified semiconductor material (such as InP or GaAs), the photo-detector and associated circuits can be epitaxially integrated on the scintillator slab and the structure can be stacked-up to achieve virtually any desired absorption capability

Spatial resolution of precipitation and radiation: the effect on regional crop yield forecasts

NARCIS (Netherlands)

Wit, de A.J.W.; Boogaard, H.L.; Diepen, van C.A.

2005-01-01

This paper explores the effect of uncertainty in precipitation and radiation on crop simulation results at local (50 × 50 km grids) and regional scale (NUTS1 regions) and on the crop yield forecasts for Germany and France. Two experiments were carried out where crop yields for winter-wheat and grain

Impact of Aerosols on Shortwave and Photosynthetically Active Radiation Balance over Sub-tropical Region in South Asia: Observational and Modeling Approach

Science.gov (United States)

Subba, T.; Pathak, B.

2016-12-01

The North-East Indian Region (NER) (22-30ºN, 89-98ºE) in south Asia sandwiched between two global biodiversity hotspots namely, Himalaya and Indo-Burma, assumes significance owing to its unique topography with mountains in the north, east and south and densely populated Indo Gangetic plains (IGP) towards the west resulting in complex aerosol system. Multi-year (2010-2014) concurrent measurements of aerosol properties and the shortwave radiation budget are examined over four geographically distinct stations of NER operational under Indian Space Research organization's ARFINET (Aerosol Radiative Forcing over India NETwork). An attempt has been made to lessen the ambiguity of forcing estimation by validating the radiative transfer modelled ARF with the CNR4 net radiometer measured values (r2 0.98). The Normalized Difference Vegetation Index and its dependence on the extinction of the photosynthetically active radiation (PAR) due to aerosol are assessed. The spring time enhancement of aerosols in the column has shown significant surface cooling (ARF = -48 ± 5 Wm-2) over the region, while the very high Black Carbon (BC) mass concentrations near the surface (SSA > 0.8) leads to significant atmospheric warming (ARF = +41 ± 7 Wm-2) in the shortwave range. Radiative forcing estimates reveal that the atmospheric forcing by BC could be as high as +30Wm-2 over the western part, which are significantly higher than the eastern part with a consequent heating rate of 1.5 K day-1 revealing an east-west asymmetry over NER. The impact of BC aerosols on the photosynthetic rate varies among different locations ranging from -5±2 Wm-2 to -25±3 Wm-2. Almost 70% of the total atmospheric shortwave radiative absorption is attributed to just 10% contribution of Black Carbon (BC) to total mass concentration and causes a reduction of more than 30% of PAR reaching the surface over Brahmaputra valley due to direct radiative effect. Comparison of previous and the present study shows highest

Investigation of radiative effects of the optically thick dust layer over the Indian tropical region

Directory of Open Access Journals (Sweden)

S. K. Das

2013-04-01

Full Text Available Optical and physical properties of aerosols derived from multi-satellite observations (MODIS-Aqua, OMI-Aura, MISR-Terra, CALIOP-CALIPSO have been used to estimate radiative effects of the dust layer over southern India. The vertical distribution of aerosol radiative forcing and heating rates are calculated with 100 m resolution in the lower atmosphere, using temperature and relative humidity data from balloon-borne radiosonde observations. The present study investigates the optically thick dust layer of optical thickness 0.18 ± 0.06 at an altitude of 2.5 ± 0.7 km over Gadanki, transported from the Thar Desert, producing radiative forcing and heating rate of 11.5 ± 3.3 W m−2 and 0.6 ± 0.26 K day−1, respectively, with a forcing efficiency of 43 W m−2 and an effective heating rate of 4 K day−1 per unit dust optical depth. Presence of the dust layer increases radiative forcing by 60% and heating rate by 60 times at that altitude compared to non-dusty cloud-free days. Calculation shows that the radiative effects of the dust layer strongly depend on the boundary layer aerosol type and mass loading. An increase of 25% of heating by the dust layer is found over relatively cleaner regions than urban regions in southern India and further 15% of heating increases over the marine region. Such heating differences in free troposphere may have significant consequences in the atmospheric circulation and hydrological cycle over the tropical Indian region.

Natural radioactivity and associated radiation characteristic of the new high background radiation area of lambwe east southern Kenya

International Nuclear Information System (INIS)

Achola, S.O.; Patel, J.P.; Angeyo, H.K.; Mustapha, A.O.

2010-01-01

Rocks and soils from a number of areas underlined by carbonatite rocks in Kenya have been associated with high levels of natural background radioactivity. People in such high background radiation areas (HBRA), are exposed to abnormally high annual absorbed dose (that have health implications) than the global normal 1 mSvyr-1. In this paper, results of field background radiation measurements, activity concentrations of primordial radionuclides in (mainly carbonatite rock and soil) matrices, and estimated annual external effective dose rates are presented for South and North Ruri hills in Lambwe East location of Suba District, which lies roughly between latitudes 0°30'S and 1°00'S, bounded on the east by longitude 34°30'E and on the west by the shores of Lake Victoria 16 and Winnam Gulf. Altitudes in the region range from about 1000 m on the shores of Lake Victoria to above 1800 m on top of the Ruri hills. The main geological features are carbonatite formations. Twenty one samples were analyzed using high-purity germanium (HPGe) gamma-ray spectrometer. The activity concentrations ranged 14.18 - 6559.99 Bqkg-1 (average: 1396.85 Bqkg-1) for Th-232; 2.73 - 499.24 Bqkg-1 (average: 178.69 Bqkg-1) for U-238; and 56.67 - 1454.73 Bqkg-1 (average: 508.67 Bqkg-1) for K-40. The variability in Th distribution could be due to another contributing factor apart from carbonatite: Homa hills geothermal field fluids might be responsible for delivery of Th to surface rocks; some hot spots have travertine deposits. Measured absorbed dose rates in air outdoors range 700 - 6000.00 nGyh-1 (mean: 2325.84 nGy h-1); assuming 0.4 occupancy factor, these values correspond to individual annual effective dose rates of 1.717 - 14.717 mSvyr-1 (mean: 5.705 mSv yr-1). Measured absorbed dose rates are higher than calculated values since they include the contribution of cosmic rays. The natural radioactivity is fractionated with higher levels in the soils than carbonatite rocks

Synchrotron Radiation

International Nuclear Information System (INIS)

Asfour, F.I

2000-01-01

Synchrotron light is produced by electron accelerators combined with storage rings. This light is generated over a wide spectral region; from infra-red (IR) through the visible and vacuum ultraviolet (VUV), and into the X-ray region. For relativistic electrons (moving nearly with the speed of light), most radiation is concentrated in a small cone with an opening angle of 1/gamma(some 0.1 to 1 milliradian),where gamma is the electron energy in units of rest energy (typically 10 3 -10 4 ). In synchrotron radiation sources (storage rings) highly relativistic electrons are stored to travel along a circular path for many hours. Radiation is caused by transverse acceleration due to magnetic forces(bending magnets). The radiation is emitted in pulses of 10-20 picosecond, separated by some 2 nanosecond or longer separation

Intercomparison of personal radiation monitoring services in the Asia/Pacific region- our participation

International Nuclear Information System (INIS)

Dhond, R.V.; Worlikar, R.M.; Saralamma Nair, D.; Pathak, A.S.; Sankaran, M.P.; Shenoy, K.S.; Patel, P.H.

1994-01-01

Radiation Protection Services Division participated in the intercomparison of personal monitoring services in Asia/Pacific region during 1991-92 organised by Australian Radiation Laboratory (ARL). The exposed films returned by ARL were processed in our laboratory. The nature and energies of the incident radiations were identified and doses evaluated in terms of new operational quantities. The doses evaluated were within ± 20% except in two cases where energy determination did not match with the ARL values. The results are presented in the paper. (author). 1 ref., 3 tabs

Radiation conditions in the Oryol region territory impacted by radioactive contamination caused by the Chernobyl NPP accident

Directory of Open Access Journals (Sweden)

G. L. Zakharchenko

2016-01-01

Full Text Available Research objective is retrospective analysis of radiation conditions in the Oryol region during 1986- 2015 and assessment of efficacy of the carried out sanitary and preventive activities for population protection against radiation contamination caused by the Chernobyl NPP accident.Article materials were own memoirs of events participants, analysis of federal state statistic surveillance forms 3-DOZ across the Oryol region, f-35 “Data on patients with malignant neoplasms, f-12 “Report on MPI activities”. Risk assessment of oncological diseases occurrence is carried out on the basis of AAED for 1986- 2014 using the method of population exposure risk assessment due to long uniform man-made irradiation in small doses. Results of medical and sociological research of genetic, environmental, professional and lifestyle factors were obtained using the method of cancer patients’ anonymous survey. Data on "risk" factors were obtained from 467 patients hospitalized at the Budgetary Health Care Institution of the Oryol region “Oryol oncology clinic”; a specially developed questionnaire with 60 questions was filled out.The article employs the method of retrospective analysis of laboratory and tool research and calculation of dose loads on the Oryol region population, executed throughout the whole period after the accident.This article provides results of the carried out laboratory research of foodstuff, environment objects describing the radiation conditions in the Oryol region since the first days after the Chernobyl NPP accident in 1986 till 2015.We presented a number of activities aimed at liquidation of man-caused radiation accident consequences which were developed and executed by the experts of the Oryol region sanitary and epidemiology service in 1986-2015. On the basis of the above-stated one may draw the conclusions listed below. Due to interdepartmental interaction and active work of executive authorities in the Oryol region, the

Fiber optics in high dose radiation fields

International Nuclear Information System (INIS)

Partin, J.K.

1985-01-01

A review of the behavior of state-of-the-art optical fiber waveguides in high dose (greater than or equal to 10 5 rad), steady state radiation fields is presented. The influence on radiation-induced transmission loss due to experimental parameters such as dose rate, total dose, irradiation history, temperature, wavelength, and light intensity, for future work in high dose environments are given

Proceedings of the 5. Regional congress on radiation protection and safety; 2. Iberian and Latin American Congress on Radiological Protection Societies; Regional IRPA Congress

International Nuclear Information System (INIS)

2001-01-01

The Fifth Regional Congress on Radiation Protection and Nuclear Safety has been held in Recife (Brazil), from 29th April to 4th May 2001. The congress was hosted by the Brazilian Radiation Protection Society, under the joint sponsorship of FRALC and UFPE-DEN Department of Nuclear Energy. Its designation as a Regional IRPA Congress has been requested. The main purpose of the meeting was to bring together professionals from the industry, universities and research laboratories to present and discuss the latest research results, and to review the state of the art on applied and fundamental aspects of the radiation protection. These specialists have talked about nuclear safety and radiological protection, radiation natural exposure, biological effect of radiation, radiotherapy and medical radiological safety, radiological safety in industry and research. In their discussions, also were included subjects related to radiological safety of nuclear and radioactive facilities, radioactive waste management, radioactive material transport, environmental radiological monitoring program, radiological emergency and accidents, instruments and dosimetry, basic safety standards of protection against radiation

A prospective study on congenital malformations in the high background radiation areas of Kerala

International Nuclear Information System (INIS)

Jaikrishan, G.; Sudheer, K.R.; Andrews, V.J.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

Hospital based epidemiological study on congenital anomalies carried out in the high level natural radiation (HLNR) areas of southern Kerala since 1995 to assess the hereditary effects, if any, of HLNR is reported here. Thorium, Uranium to a limited extent, and corresponding decay products in the natural deposits of monazite sand is the source of radiation. HLNR and normal level natural radiation (NLNR) areas are interwoven due to the patchy and non-uniform distribution of monazite in the region. Areas with a mean dose of more than 1.5 mGy/year were treated as HLNR areas and those with 1.5 mGy/year or less, as NLNR. High population density, limited migration, ethnic diversity, good literacy, health awareness, institutionalized births and acceptance of small family norm are some of the key features of the population. The comparison of individual malformation in HLNR and NLNR areas are presented and efforts are on to accrue sufficient sample size to enable the comparison

High Efficency Lightweight Radiators, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — XC Associates proposes to build on prior work to develop and characterize a very high efficiency, lightweight radiator constructed from high thermal conductivity...

Fungal radiation in the Cape Floristic Region: an analysis based on Gondwanamyces and Ophiostoma.

Science.gov (United States)

Roets, F; Wingfield, M J; Crous, P W; Dreyer, L L

2009-04-01

The Cape Floristic Region (CFR) displays high levels of plant diversity and endemism, and has received focused botanical systematic attention. In contrast, fungal diversity patterns and co-evolutionary processes in this region have barely been investigated. Here we reconstruct molecular phylogenies using the ITS and beta-tubulin gene regions of the ophiostomatoid fungi Gondwanamyces and Ophiostoma associated with southern African Protea species. Results indicate that they evolved in close association with Protea. In contrast to Protea, Ophiostoma species migrated to the CFR from tropical and subtropical Africa, where they underwent subsequent radiation. In both Gondwanamyces and Ophiostoma vector arthropods probably facilitated long-distance migration and shorter-distance dispersal. Although ecological parameters shaped most associations between ophiostomatoid fungi and Protea, there is congruence between fungal-host-associations and the systematic classification of Protea. These results confirm that the entire biotic environment must be considered in order to understand diversity and evolution in the CFR as a whole.

Estimating the horizontal diffuse solar radiation over the Central Anatolia Region of Turkey

International Nuclear Information System (INIS)

Aras, Haydar; Balli, Ozgur; Hepbasli, Arif

2006-01-01

The main objective of the present study is to develop new hybrid models to predict the monthly average daily diffuse solar radiation on a horizontal surface over Turkey's Central Anatolia Region (CAR), which covers the 12 provinces (Afyon, Ankara, Cankiri, Corum, Eskisehir, Kayseri, Kirsehir, Konya, Nevsehir, Nigde, Sivas and Yozgat), as an example. The models proposed by many investigators to estimate the diffuse solar radiation were reviewed. Although the global solar radiation and sunshine duration have been measured by the Turkish State Meteorological Service (DMI) over all the country since 1964, the diffuse solar radiation has not been measured. The twelve new hybrid models for estimating the monthly average daily diffuse solar radiation on a horizontal surface in the CAR were validated, and thus, the most accurate model was selected for guiding future projects

The effect of patient-specific factors on radiation-induced regional lung injury

International Nuclear Information System (INIS)

Garipagaoglu, Melahat; Munley, Michael T.; Hollis, Donna; Poulson, Jean M.; Bentel, Gunilla C.; Sibley, Gregory; Anscher, Mitchell S.; Fan Ming; Jaszczak, Ronald J.; Coleman, R. Edward; Marks, Lawrence B.

1999-01-01

Purpose: To assess the impact of patient-specific factors on radiation (RT)-induced reductions in regional lung perfusion. Methods: Fifty patients (32 lung carcinoma, 7 Hodgkin's disease, 9 breast carcinoma and 2 other thoracic tumors) had pre-RT and ≥24-week post-RT single photon emission computed tomography (SPECT) perfusion images to assess the dose dependence of RT-induced reductions in regional lung perfusion. The SPECT data were analyzed using a normalized and non-normalized approach. Furthermore, two different mathematical methods were used to assess the impact of patient-specific factors on the dose-response curve (DRC). First, DRCs for different patient subgroups were generated and compared. Second, in a more formal statistical approach, individual DRCs for regional lung injury for each patient were fit to a linear-quadratic model (reduction = coefficient 1 x dose + coefficient 2 x dose 2 ). Multiple patient-specific factors including tobacco history, pre-RT diffusion capacity to carbon monoxide (DLCO), transforming growth factor-beta (TGF-β), chemotherapy exposure, disease type, and mean lung dose were explored in a multivariate analysis to assess their impact on the coefficients. Results: None of the variables tested had a consistent impact on the radiation sensitivity of regional lung (i.e., the slope of the DRC). In the formal statistical analysis, there was a suggestion of a slight increase in radiation sensitivity in the dose range >40 Gy for nonsmokers (vs. smokers) and in those receiving chemotherapy (vs. no chemotherapy). However, this finding was very dependent on the specific statistical and normalization method used. Conclusion: Patient-specific factors do not have a dramatic effect on RT-induced reduction in regional lung perfusion. Additional studies are underway to better clarify this issue. We continue to postulate that patient-specific factors will impact on how the summation of regional injury translates into whole organ injury

Regional environmental documentation of natural radiation in Sweden

International Nuclear Information System (INIS)

Wilson, C.

1982-01-01

In 1979, when the problem of high radon daughter levels in Swedish houses became widely published, the need for information on variations in the natural radiation environment became very apparent. The radon problem was at first attributed to radon emanation from alum shale based aerated concrete, but it was soon obvious that ground with an abnormally high uranium content constitutes an even greater risk for high radon daughter levels in houses. The geological Survey of Sweden was commissioned to produce a documentation in map form for all areas and rock types with gamma ray levels exceeding 30 μR/h, with the intention of delimiting risk areas for high soil gas radon contents. The maps, known as GEO-radiation maps, are produced at scale of 1:50 000. They are based primarily upon radiometric surveys, ground measurements of gammaradiation and geological mapping. To date some 450 map sheets have been published covering approximately 55% of the country. The maps provide primary information to local planning, health and building authorities as to variations in the natural radiation environment. Within the so-called risk areas marked on the maps, local authorities are recommended to investigate the soil gas radon content prior to any new development. Geological environments known, in Sweden, to be associated with radon daughter problems in dwellings are alum shale, a Cambrian, uranium-rich black shale, uranium-rich granites and uranium-rich pegmatites. Both alum shale and uranium-rich granites constitute extensive areas of bedrock. More recently it has been established that high soil-gas radon concentrations are also associated with glacial eskers. (Author)

Compact high-power terahertz radiation source

Directory of Open Access Journals (Sweden)

G. A. Krafft

2004-06-01

Full Text Available In this paper a new type of THz radiation source, based on recirculating an electron beam through a high gradient superconducting radio frequency cavity, and using this beam to drive a standard electromagnetic undulator on the return leg, is discussed. Because the beam is recirculated and not stored, short bunches may be produced that radiate coherently in the undulator, yielding exceptionally high average THz power for relatively low average beam power. Deceleration from the coherent emission, and the detuning it causes, limits the charge-per-bunch possible in such a device.

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.

Role of dust direct radiative effect on the tropical rainbelt over Middle East and North Africa: A high resolution AGCM study

KAUST Repository

Bangalath, Hamza Kunhu

2015-04-25

To investigate the influence of direct radiative effect of dust on the tropical summer rainbelt across the Middle East and North Africa (MENA), the present study utilizes the high resolution capability of an Atmospheric General Circulation Model (AGCM),the High Resolution Atmospheric Model (HiRAM). Ensembles of Atmospheric Model Inter-comparison Project (AMIP)-style simulations have been conducted with and without dust radiative impacts, to differentiate the influence of dust on the tropical rainbelt. The analysis focuses on summer season. The results highlight the role of dust induced responses in global and regional scale circulations in determining the strength and the latitudinal extent of the tropical rainbelt. A significant response in the strength and position of the local Hadley circulation is predicted in response to meridionally asymmetric distribution of dust and the corresponding radiative effects. Significant responses are also found in regional circulation features such as African Easterly Jet (AEJ) and West African Monsoon (WAM) circulation. Consistent with these dynamic responses at various scales, the tropical rainbelt across MENA strengthens and shifts northward. Importantly, the summer precipitation over the semi-arid strip south of Sahara, including Sahel, increases up to 20%. As this region is characterized by the “Sahel drought" , the predicted precipitation sensitivity to the dust loading over this region has a wide-range of socioeconomic implications. Overall, the study demonstrates the extreme importance of incorporating dust radiative effects and the corresponding circulation responses at various scales, in the simulations and future projections of this region\\'s climate.

6. Regional Congress on Radiation Protection and Safety; 3. Iberian and Latin American Congress on Radiological Protection Societies; Regional IRPA Congress. Book of abstracts

International Nuclear Information System (INIS)

2003-11-01

The 6th Regional Congress on Radiation Protection and Safety was organized by the Peruvian Radiation Protection Society and the Peruvian Institute of Nuclear Energy, held in Lima, Peru, between 9 and 13 of november of 2003. In this event, were presented 227 papers that were articulated in the following sessions: radiation natural exposure, biological effects of ionizing radiation, instruments and dosimetry, radiological emergency and accidents, occupational radiation protection, radiological protection in medical exposure, radiological environmental protection, legal aspects, standards and regulations, training, education and communication, radioactive waste management, radioactive material transport, nuclear safety and biological effects of non-ionizing radiation. (APC)

Physics of intense, high energy radiation effects

International Nuclear Information System (INIS)

Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

2011-01-01

This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic calculations, the

Calibration technique for radiation measurements in vacuum ultraviolet - soft x-ray region

International Nuclear Information System (INIS)

Mizui, Jun-ichi

1986-05-01

This is a collection of the papers presented at the workshop on ''Calibration Technique for Radiation Measurements in Vacuum Ultraviolet - Soft X-ray Region'' held at the Institute of Plasma Physics, Nagoya University, on December 19 - 20, 1985, under the Collaborating Research Program at the Institute. The following topics were discussed at the workshop: the needs for the calibration of plasma diagnostic devices, present status of the calibration technique, use of the Synchrotron Orbit Radiations for radiometry, and others. (author)

Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions

International Nuclear Information System (INIS)

Johnson, B.M.; Meron, M.; Agagu, A.; Jones, K.W.

1986-01-01

Synchrotron radiation can be used to produce highly-charged ions, and to study photoexcitation and photoionization for ions of virtually any element in the periodic table. To date, with few exceptions, atomic physics studies have been limited to rare gases and a few metal vapors, and to photoexcitation energies in the VUV region of the electromagnetic spectrum. These limitations can now be overcome using photons produced by high-brightness synchrotron storage rings, such as the x-ray ring at the National Synchrotron Light Source (NSLS) at Brookhaven. Furthermore, calculations indicate that irradiation of an ion trap with an intense energetic photon beam will result in a viable source of highly-charged ions that can be given the name PHOBIS: the PHOton Beam Ion Source. Promising results, which encourage the wider systematic use of synchrotron radiation in atomic physics research, have been obtained in recent experiments on VUV photoemission and the production and storage of multiply-charged ions. 26 refs., 4 figs., 1 tab

Cloud-radiation-precipitation associations over the Asian monsoon region: an observational analysis

Science.gov (United States)

Li, Jiandong; Wang, Wei-Chyung; Dong, Xiquan; Mao, Jiangyu

2017-11-01

This study uses 2001-2014 satellite observations and reanalyses to investigate the seasonal characteristics of Cloud Radiative Effects (CREs) and their associations with cloud fraction (CF) and precipitation over the Asian monsoon region (AMR) covering Eastern China (EC) and South Asia (SA). The CREs exhibit strong seasonal variations but show distinctly different relationships with CFs and precipitation over the two regions. For EC, the CREs is dominated by shortwave (SW) cooling, with an annual mean value of - 40 W m- 2 for net CRE, and peak in summer while the presence of extensive and opaque low-level clouds contributes to large Top-Of-Atmosphere (TOA) albedo (>0.5) in winter. For SA, a weak net CRE exists throughout the year due to in-phase compensation of SWCRE by longwave (LW) CRE associated with the frequent occurrence of high clouds. For the entire AMR, SWCRE strongly correlates with the dominant types of CFs, although the cloud vertical structure plays important role particularly in summer. The relationships between CREs and precipitation are stronger in SA than in EC, indicating the dominant effect of monsoon circulation in the former region. SWCRE over EC is only partly related to precipitation and shows distinctive regional variations. Further studies need to pay more attention to vertical distributions of cloud micro- and macro-physical properties, and associated precipitation systems over the AMR.

Individual Dosimetry for High Energy Radiation Fields

International Nuclear Information System (INIS)

Spurny, F.

1999-01-01

The exposure of individuals on board aircraft increased interest in individual dosimetry in high energy radiation fields. These fields, both in the case of cosmic rays as primary radiation and at high energy particle accelerators are complex, with a large diversity of particle types, their energies, and linear energy transfer (LET). Several already existing individual dosemeters have been tested in such fields. For the component with high LET (mostly neutrons) etched track detectors were tested with and without fissile radiators, nuclear emulsions, bubble detectors for both types available and an albedo dosemeter. Individual dosimetry for the low LET component has been performed with thermoluminescent detectors (TLDs), photographic film dosemeters and two types of electronic individual dosemeters. It was found that individual dosimetry for the low LET component was satisfactory with the dosemeters tested. As far as the high LET component is concerned, there are problems with both the sensitivity and the energy response. (author)

High Radiation Resistance IMM Solar Cell

Science.gov (United States)

Pan, Noren

2015-01-01

Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

Strengthening of radiation protection in the Baltic Sea Region and North west-Russia

International Nuclear Information System (INIS)

Ake Persson, B.; Olof Snihs, Jan

2000-01-01

There are a number of strong radiation sources in the Baltic Sea Region and Northwest Europe (Northwest Russia). They include more than 30 nuclear power reactors, various other operating facilities with radiation sources, a number of radioactive waste repositories and several stores for spent nuclear fuel. Many of these facilities are in good shape and under good control from the authorities. Others are in a very poor condition and there is a need of immediate actions to be taken. This is particular the case in the Northwest part of Russia. The strengthening of radiation protection in the two regions mentioned above is made by national efforts and through international co-operation including various support activities. The close geographical position with common seas, the developing economical and cultural co-operation between the countries as well as connections with historical background means that there is an interest and common benefit to strengthen the co-operation in the field of radiation protection and radiological emergency planning. Sweden has since the disintegration of the Soviet Union a policy to assist and support the Baltic States and the Russian Federation in the field of radiation protection and to strengthen the preparedness for co-operation between the countries in the event of a severe nuclear accident or radiological emergency. The problems, strategies, results and failures up to now will be described as well as how these efforts are integrated in and put into perspective of the development of radiation protection in the donor countries. There are also efforts to integrate most of the countries in common policy work, research and technical development in the field of radiation protection. Some perspectives into the next millennium are discussed. (author)

Distortions in the Rayleigh-Jeans region of the cosmic background radiation spectrum

International Nuclear Information System (INIS)

De Zotti, G.

1982-01-01

The theory of the origin and evolution of distortions in the Rayleigh-Jeans region of the cosmic background radiation spectrum is reviewed. Some proposed experiments, designed to substantially improve our knowledge of that portion of the spectrum, are briefly described. (author)

Terahertz radiation mixer

Science.gov (United States)

Wanke, Michael C [Albuquerque, NM; Allen, S James [Santa Barbara, CA; Lee, Mark [Albuquerque, NM

2008-05-20

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

High mortality of Red Sea zooplankton under ambient solar radiation.

Science.gov (United States)

Al-Aidaroos, Ali M; El-Sherbiny, Mohsen M O; Satheesh, Sathianeson; Mantha, Gopikrishna; Agustī, Susana; Carreja, Beatriz; Duarte, Carlos M

2014-01-01

High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiation doses with zooplankton mortality were evaluated by exposing organisms, enclosed in quartz bottles, allowing all the wavelengths of solar radiation to penetrate, to five different levels of ambient solar radiation (100%, 21.6%, 7.2%, 3.2% and 0% of solar radiation). The maximum mortality rates under ambient solar radiation levels averaged (±standard error of the mean, SEM) 18.4±5.8% h(-1), five-fold greater than the average mortality in the dark for the eight taxa tested. The UV-B radiation required for mortality rates to reach ½ of maximum values averaged (±SEM) 12±5.6 h(-1)% of incident UVB radiation, equivalent to the UV-B dose at 19.2±2.7 m depth in open coastal Red Sea waters. These results confirm that Red Sea zooplankton are highly vulnerable to ambient solar radiation, as a consequence of the combination of high incident radiation and high water transparency allowing deep penetration of damaging UV-B radiation. These results provide evidence of the significance of ambient solar radiation levels as a stressor of marine zooplankton communities in tropical, oligotrophic waters. Because the oligotrophic ocean extends across 70% of the ocean surface, solar radiation can be a globally-significant stressor for the ocean ecosystem, by constraining zooplankton use of the upper levels of the water column and, therefore, the efficiency of food transfer up the food web in the oligotrophic ocean.

High mortality of Red Sea zooplankton under ambient solar radiation.

Directory of Open Access Journals (Sweden)

Ali M Al-Aidaroos

Full Text Available High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiation doses with zooplankton mortality were evaluated by exposing organisms, enclosed in quartz bottles, allowing all the wavelengths of solar radiation to penetrate, to five different levels of ambient solar radiation (100%, 21.6%, 7.2%, 3.2% and 0% of solar radiation. The maximum mortality rates under ambient solar radiation levels averaged (±standard error of the mean, SEM 18.4±5.8% h(-1, five-fold greater than the average mortality in the dark for the eight taxa tested. The UV-B radiation required for mortality rates to reach ½ of maximum values averaged (±SEM 12±5.6 h(-1% of incident UVB radiation, equivalent to the UV-B dose at 19.2±2.7 m depth in open coastal Red Sea waters. These results confirm that Red Sea zooplankton are highly vulnerable to ambient solar radiation, as a consequence of the combination of high incident radiation and high water transparency allowing deep penetration of damaging UV-B radiation. These results provide evidence of the significance of ambient solar radiation levels as a stressor of marine zooplankton communities in tropical, oligotrophic waters. Because the oligotrophic ocean extends across 70% of the ocean surface, solar radiation can be a globally-significant stressor for the ocean ecosystem, by constraining zooplankton use of the upper levels of the water column and, therefore, the efficiency of food transfer up the food web in the oligotrophic ocean.

Radiation heat transfer calculations for the uranium fuel-containment region of the nuclear light bulb engine.

Science.gov (United States)

Rodgers, R. J.; Latham, T. S.; Krascella, N. L.

1971-01-01

Calculation results are reviewed of the radiant heat transfer characteristics in the fuel and buffer gas regions of a nuclear light bulb engine based on the transfer of energy by thermal radiation from gaseous uranium fuel in a neon vortex, through an internally cooled transparent wall, to seeded hydrogen propellant. The results indicate that the fraction of UV energy incident on the transparent walls increases with increasing power level. For the reference engine power level of 4600 megw, it is necessary to employ space radiators to reject the UV radiated energy absorbed by the transparent walls. This UV energy can be blocked by employing nitric oxide and oxygen seed gases in the fuel and buffer gas regions. However, this results in increased UV absorption in the buffer gas which also requires space radiators to reject the heat load.

Improvement of dose distributions in abutment regions of intensity modulated radiation therapy and electron fields

International Nuclear Information System (INIS)

Dogan, Nesrin; Leybovich, Leonid B.; Sethi, Anil; Emami, Bahman

2002-01-01

In recent years, intensity modulated radiation therapy (IMRT) is used to radiate tumors that are in close proximity to vital organs. Targets consisting of a deep-seated region followed by a superficial one may be treated with abutting photon and electron fields. However, no systematic study regarding matching of IMRT and electron beams was reported. In this work, a study of dose distributions in the abutment region between tomographic and step-and-shoot IMRT and electron fields was carried out. A method that significantly improves dose homogeneity between abutting tomographic IMRT and electron fields was developed and tested. In this method, a target region that is covered by IMRT was extended into the superficial target area by ∼2.0 cm. The length and shape of IMRT target extension was chosen such that high isodose lines bent away from the region treated by the electrons. This reduced the magnitude of hot spots caused by the 'bulging effect' of electron field penumbra. To account for the uncertainties in positioning of the IMRT and electron fields, electron field penumbra was modified using conventional (photon) multileaf collimator (MLC). The electron beam was delivered in two steps: half of the dose delivered with MLCs in retracted position and another half with MLCs extended to the edge of electron field that abuts tomographic IMRT field. The experimental testing of this method using film dosimetry has demonstrated that the magnitude of the hot spots was reduced from ∼45% to ∼5% of the prescription dose. When an error of ±1.5 mm in field positioning was introduced, the dose inhomogeneity in the abutment region did not exceed ±15% of the prescription dose. With step-and-shoot IMRT, the most homogeneous dose distribution was achieved when there was a 3 mm gap between the IMRT and electron fields

Physics of intense, high energy radiation effects.

Energy Technology Data Exchange (ETDEWEB)

Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

2011-02-01

This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic

Radiation safety aspects of high energy particle accelerators

International Nuclear Information System (INIS)

Subbaiah, K.V.

2007-01-01

High-energy accelerators are widely used for various applications in industry, medicine and research. These accelerators are capable of accelerating both ions and electrons over a wide range of energy and subsequently are made to impinge on the target materials. Apart from generating intended reactions in the target, these projectiles can also generate highly penetrating radiations such as gamma rays and neutrons. Over exposure to these radiations will cause deleterious effects on the living beings. Various steps taken to protect workers and general public from these harmful radiations is called radiation safety. The primary objective in establishing permissible values for occupational workers is to keep the radiation worker well below a level at which adverse effects are likely to be observed during one's life time. Another objective is to minimize the incidence of genetic effects for the population as a whole. Today's presentation on radiation safety of accelerators will touch up on the following sub-topics: Types of particle accelerators and their applications; AERB directives on dose limits; Radiation Source term of accelerators; Shielding Design-Use of Transmission curves and Tenth Value layers; Challenges for accelerator health physicists

Substantiation of the radiation monitoring scope in the region of nuclear power plant location

Energy Technology Data Exchange (ETDEWEB)

Zykova, A S; Zhakov, Yu A; Yambrovskii, Ya M

1977-12-01

To provide radiation safety of the population in the region of nuclear power plant location, it is necessary to define the character and quantity of radiation monitoring. On the basis of radiation monitoring of effluents from operating nuclear power plants it is found that the effluents can be registered at a distance of 5-7 km from the plant. The quantity of sample analysis of the main enviromental objectives must provide an exact definition of the content of radioactive substances produced by radioactive fallouts and effluents from nuclear power plants.

Substantiation of the radiation monitoring scope in the region of nuclear power plant location

International Nuclear Information System (INIS)

Zykova, A.S.; Zhakov, Yu.A.; Jambrovskij, Ya.M.

1977-01-01

To provide radiation safety of the population in the region of nuclear power plant location, it is necessary to define the character and quantity of radiation monitoring. On the basis of radiation monitoring of flowouts from operating nuclear power plants it is found that the flowouts can be registered at a distance of 5-7 km from the plant. The quantity of sample analysis of the main enviromental objectives must provide an exact definition of the content of radioactive substances produced by radioactive fallouts and flowouts from nuclear power plants

Radiation hygiene supervision of X-ray units in veterinary establishments of the South Bohemian Region

International Nuclear Information System (INIS)

Truelle, M.A.

1976-01-01

The number of X-ray examinations increased after 1971 with the launching of the nation-wide screening of breeding boars and sows for rhinitis. For this purpose the Regional Hygiene Officer permitted the use of CHIRAX X-ray apparatus in field-work. Blood sampling and medical check-ups are carried out of all workers by the Department of Occupational Diseases of the Regional Health Centre in Ceske Budejovice. All X-ray operators are equipped with film dosemeters. Hygienic inspection is regularly carried out by the Department of Radiation Hygiene of the Regional Hygiene Centre in Ceske Budejovice. The screenings are carried out in the pigsty or in the preparation room. The X-ray operators operate behind a Pb shield. The animal is tied up and the plate is inserted into its oral cavity. The auxiliary staff keeps as far away as possible from the X-ray apparatus. At a distance of 6 m from the X-ray apparatus the radiation intensity of 3 mR/h was measured. The harmful radiation dose is far below permissible values (5 rem/year). (O.Y.)

RADIATION CONDITIONS IN KALUGA REGION 30 YEARS AFTER CHERNOBYL NPP ACCIDENT

Directory of Open Access Journals (Sweden)

A. G. Ashitko

2016-01-01

effective doses, caused90by Chernobyl fallouts, do not exceed 1 mSv/year. In 2014 AAEDmaximum calculated value for adultpopulation of 0,91 mSv was established in the following settlements:, Martynki village(Ulyanovsky district and Lovatyanka village (Hvastovichsky district. The doses, accumulated in the period after the accident, are generally not high. According to calculations numerical value of forecasted accumulated doses varies from 0,23 to 21 mSv. Maximum calculated values of 21 mSv are established in Hvastovichsky district (Lovatyanka village and Ulyanovsky district (Martynki village. Between 1986 and 2005, the effective irradiation doses did not exceed 29 mSv. Hence, in 70 years after the Chernobyl NPP accident standard value of 70 mSv will not be exceeded in the Kaluga region settlements. After 30 years, the main cause of population internal exposure is consumption of products from private subsidiary farms and especially of wild-growing products. There was conducted radiation monitoring of local agricultural foodstuff produce and of products from the forest. It demonstrated that caesium-137 average specific activity in samples of milk from private subsidiary farms in settlements of Zhizdrinsky, Ulyanovsky and Hvastovichsky districts decreased several-fold. It is between 20,0 Bq/l in 2007 and 1,7 Bq/l in 2015. In 2015, maximum levels of caesium-137 contamination in milk was 3,1% of the standard value, in potatoes - 4,7%, in meat - 4,4%.Average specific activity of caesium-137 in forest mushrooms samples from Zhizdrinsky, Ulyanovsky and Hvastovichsky districts doesn’t decline. Peaks of average caesium-137 activity were observed in 2012, 2013 and 2014; they depend on mushrooms abundance, species, dry summer weather and locations of sampling in the forest. In 2015 in three southern districts, the maximum content of caesium-137 in mushrooms exceeded the permissible level (500 Bq/kg 4,5-fold; about 2% of the samples do not correspond to it. The maximum contamination of

Regional training course on radiation dosimetry. 9 October - 4 November 1989, P.R. of China, Shanghai

International Nuclear Information System (INIS)

1990-01-01

Full text: This regional training course on radiation dosimetry was organized by the Agency in co-operation with the Government of the People's Republic of China and was held at the Shanghai Institute of Metrological Technology (SIMT), one of the four SSDLs in China. The purpose of this regional Training course was to provide theoretical and practical training on calibration and standardization of ionizing radiation. Special emphasis was placed on high energy x-rays, gamma rays and high energy electrons. Discussions and evaluations on progress made in different SSDLs in the region were also foreseen. This course was designed for junior staff from SSDLs and other institutions providing radiation dosimetry services. The course was open for up to 25 candidates from developing Member States in the Asia and Pacific region. The Agency announced this course by invitation letters to 16 government authorities of Member States in the region. Altogether 22 participants from 13 Member States and Hong Kong and two observers from the host country attended the course during its entire period. Transportation provided by SIMT, the working condition at SIMT, the food and accommodation at the Shanghai Education Centre of International Exchange were adequate. The hospitality and social programme offered by the host institute and its staff were noted by the participants with satisfaction. A television team from SIMT recorded the whole training course and the social events and prepared a video cassette with 120 minutes recording. It was made available for RMB 100. A total of 56 theoretical lectures were given during the four weeks by Messrs. H. Svensson, N.J. Hargrave, Y. Kawada, R. Girzikowsky and J.G. Haider. Another 10 hours of lectures were covered by the 10 local lecturers and about 10 hours were spent for the presentation of the reports from the 22 participants and the two observers. The practical part was covered by a total of 48 hours of laboratory exercises and demonstrations

Neural network radiative transfer solvers for the generation of high resolution solar irradiance spectra parameterized by cloud and aerosol parameters

International Nuclear Information System (INIS)

Taylor, M.; Kosmopoulos, P.G.; Kazadzis, S.; Keramitsoglou, I.; Kiranoudis, C.T.

2016-01-01

This paper reports on the development of a neural network (NN) model for instantaneous and accurate estimation of solar radiation spectra and budgets geared toward satellite cloud data using a ≈2.4 M record, high-spectral resolution look up table (LUT) generated with the radiative transfer model libRadtran. Two NN solvers, one for clear sky conditions dominated by aerosol and one for cloudy skies, were trained on a normally-distributed and multiparametric subset of the LUT that spans a very broad class of atmospheric and meteorological conditions as inputs with corresponding high resolution solar irradiance target spectra as outputs. The NN solvers were tested by feeding them with a large (10 K record) “off-grid” random subset of the LUT spanning the training data space, and then comparing simulated outputs with target values provided by the LUT. The NN solvers demonstrated a capability to interpolate accurately over the entire multiparametric space. Once trained, the NN solvers allow for high-speed estimation of solar radiation spectra with high spectral resolution (1 nm) and for a quantification of the effect of aerosol and cloud optical parameters on the solar radiation budget without the need for a massive database. The cloudy sky NN solver was applied to high spatial resolution (54 K pixel) cloud data extracted from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the geostationary Meteosat Second Generation 3 (MSG3) satellite and demonstrated that coherent maps of spectrally-integrated global horizontal irradiance at this resolution can be produced on the order of 1 min. - Highlights: • Neural network radiative transfer solvers for generation of solar irradiance spectra. • Sensitivity analysis of irradiance spectra with respect to aerosol and cloud parameters. • Regional maps of total global horizontal irradiance for cloudy sky conditions. • Regional solar radiation maps produced directly from MSG3/SEVIRI satellite inputs.

Teaching of radiation for elementary and junior high students in Kagoshima and its effects on their radiation literacy

International Nuclear Information System (INIS)

Fukutoku, Yasuo

2009-01-01

Teaching of radiation-related subjects for school children takes an important part in promotion of social radiation literacy; however, the effect of school education on radiation literacy of students, as well as the current status regarding how and when children acquire their knowledge on radiation, have not been elucidated in Japan. In 2005 and 2006, a written surveillance on radiation education was conducted twice in Kagoshima prefecture targeting elementary and junior-high students under the consent of school teachers. Based on the results of these surveillances, the followings were revealed; (1) The elementary and junior-high students receive the information on radiation mainly by the conventional media, including books, television and radio, rather than by school education. (2) More than a half of all junior-high schools are teaching radiation-related subjects, in classes called 'Integrated study', 'Social studies', and 'Science'. (3) The cross tabulation analysis revealed that among the Novel Prize winners on radiation-related fields, 'Pierre and Marie Curie', 'Yukawa' and 'Tomonaga' were recognized by junior-high students by the conventional media, whereas 'Roentgen' and 'Koshiba' appeared to be recognized by school education. (4) Among the scientific terms, junior-high education seems to have some effect on recognition of 'radiation', 'radioactivity' and 'natural radiation'. 'X-rays' was highly recognized, however, the contribution of school education to the recognition was not significant. (5) Among the application examples of radiation, sources other than school education had a large effect on recognition of 'food irradiation', 'sterilization' of medical instruments, 'research on cultural assets' and 'dating', although the recognition was marginal. In contrast, the 'cancer treatment

Radiation Attenuation and Stability of ClearView Radiation Shielding TM-A Transparent Liquid High Radiation Shield.

Science.gov (United States)

Bakshi, Jayeesh

2018-04-01

Radiation exposure is a limiting factor to work in sensitive environments seen in nuclear power and test reactors, medical isotope production facilities, spent fuel handling, etc. The established choice for high radiation shielding is lead (Pb), which is toxic, heavy, and abidance by RoHS. Concrete, leaded (Pb) bricks are used as construction materials in nuclear facilities, vaults, and hot cells for radioisotope production. Existing transparent shielding such as leaded glass provides minimal shielding attenuation in radiotherapy procedures, which in some cases is not sufficient. To make working in radioactive environments more practicable while resolving the lead (Pb) issue, a transparent, lightweight, liquid, and lead-free high radiation shield-ClearView Radiation Shielding-(Radium Incorporated, 463 Dinwiddie Ave, Waynesboro, VA). was developed. This paper presents the motivation for developing ClearView, characterization of certain aspects of its use and performance, and its specific attenuation testing. Gamma attenuation testing was done using a 1.11 × 10 Bq Co source and ANSI/HPS-N 13.11 standard. Transparency with increasing thickness, time stability of liquid state, measurements of physical properties, and performance in freezing temperatures are reported. This paper also presents a comparison of ClearView with existing radiation shields. Excerpts from LaSalle nuclear power plant are included, giving additional validation. Results demonstrated and strengthened the expected performance of ClearView as a radiation shield. Due to the proprietary nature of the work, some information is withheld.

Should regional ventilation function be considered during radiation treatment planning to prevent radiation-induced complications?

Energy Technology Data Exchange (ETDEWEB)

Lan, Fujun; Jeudy, Jean; D’Souza, Warren; Tseng, Huan-Hsin; Zhou, Jinghao; Zhang, Hao, E-mail: haozhang@som.umaryland.edu [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Senan, Suresh; Sornsen de Koste, J. R. van [Department of Radiation Oncology, VU University Medical Center, P.O. Box 7057, Amsterdam 1007 MB (Netherlands)

2016-09-15

Purpose: To investigate the incorporation of pretherapy regional ventilation function in predicting radiation fibrosis (RF) in stage III nonsmall cell lung cancer (NSCLC) patients treated with concurrent thoracic chemoradiotherapy. Methods: Thirty-seven patients with stage III NSCLC were retrospectively studied. Patients received one cycle of cisplatin–gemcitabine, followed by two to three cycles of cisplatin–etoposide concurrently with involved-field thoracic radiotherapy (46–66 Gy; 2 Gy/fraction). Pretherapy regional ventilation images of the lung were derived from 4D computed tomography via a density change–based algorithm with mass correction. In addition to the conventional dose–volume metrics (V{sub 20}, V{sub 30}, V{sub 40}, and mean lung dose), dose–function metrics (fV{sub 20}, fV{sub 30}, fV{sub 40}, and functional mean lung dose) were generated by combining regional ventilation and radiation dose. A new class of metrics was derived and referred to as dose–subvolume metrics (sV{sub 20}, sV{sub 30}, sV{sub 40}, and subvolume mean lung dose); these were defined as the conventional dose–volume metrics computed on the functional lung. Area under the receiver operating characteristic curve (AUC) values and logistic regression analyses were used to evaluate these metrics in predicting hallmark characteristics of RF (lung consolidation, volume loss, and airway dilation). Results: AUC values for the dose–volume metrics in predicting lung consolidation, volume loss, and airway dilation were 0.65–0.69, 0.57–0.70, and 0.69–0.76, respectively. The respective ranges for dose–function metrics were 0.63–0.66, 0.61–0.71, and 0.72–0.80 and for dose–subvolume metrics were 0.50–0.65, 0.65–0.75, and 0.73–0.85. Using an AUC value = 0.70 as cutoff value suggested that at least one of each type of metrics (dose–volume, dose–function, dose–subvolume) was predictive for volume loss and airway dilation, whereas lung consolidation

Construction of a forensic soil database of the Hokkaido region in Japan by synchrotron radiation X-ray analysis

International Nuclear Information System (INIS)

Shirota, Yusuke; Hirao, Masataka; Abe, Yoshinari; Nakai, Izumi; Osaka, Keiichi; Itou, Masayoshi

2017-01-01

The purpose of the present study is to construct a nation-wide forensic soil database, which allows for the identification of soil evidence based on heavy element and heavy mineral signatures determined by two synchrotron radiation (SR) X-ray techniques, i.e., a high-energy synchrotron radiation X-ray fluorescence analysis and a synchrotron-radiation X-ray powder diffraction analysis, respectively. The heavy element and heavy mineral compositions of the stream sediments collected at 3024 points located all over Japan were measured by the two SR X-ray techniques. The present paper focuses on a regional characterization of the sediments collected from the Hokkaido areas. The concentrations of heavy elements and heavy minerals in the Hokkaido areas were visualized as maps that enable us to compare the heavy element and heavy mineral compositions with the geological context of the samples. Based on a hierarchical cluster analysis using the semi-quantitative compositions of the heavy minerals, we could successfully classify the sediments into six groups corresponding to their background geologies. A Bonferroni multiple comparison demonstrated that these six groups also have significant differences in the heavy element composition. From these examinations, we could demonstrate that detailed regional identification of unknown samples is possible by analyzing both heavy element and heavy mineral compositions of each sample. (author)

Progress in high-dose radiation dosimetry

International Nuclear Information System (INIS)

Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.; Chadwick, K.H.

1981-01-01

The last decade has witnessed a deluge of new high-dose dosimetry techniques and expanded applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Reference systems also include a number of chemical dose meters: ferrous sulphate, ferrous-cupric sulphate, and ceric sulphate acidic aqueous solutions. Requirements for stable and reliable transfer dose meters have led to further developments of several important high-dose systems: amino acids and saccharides analysed by ESR or lyoluminescence, thermoluminescent materials, radiochromic dyes and plastics, ceric-cerous solutions analysed by potentiometry, and ethanol-chlorobenzene solutions analysed by high-frequency oscillometry. A number of other prospective dose meters are also treated in this review. In addition, an IAEA programme of high-dose standardization and intercomparison for industrial radiation processing is described. (author)

The 1994 Northridge, California, earthquake: Investigation of rupture velocity, risetime, and high-frequency radiation

Science.gov (United States)

Hartzell, S.; Liu, P.; Mendoza, C.

1996-01-01

A hybrid global search algorithm is used to solve the nonlinear problem of calculating slip amplitude, rake, risetime, and rupture time on a finite fault. Thirty-five strong motion velocity records are inverted by this method over the frequency band from 0.1 to 1.0 Hz for the Northridge earthquake. Four regions of larger-amplitude slip are identified: one near the hypocenter at a depth of 17 km, a second west of the hypocenter at about the same depth, a third updip from the hypocenter at a depth of 10 km, and a fourth updip from the hypocenter and to the northwest. The results further show an initial fast rupture with a velocity of 2.8 to 3.0 km/s followed by a slow termination of the rupture with velocities of 2.0 to 2.5 km/s. The initial energetic rupture phase lasts for 3 s, extending out 10 km from the hypocenter. Slip near the hypocenter has a short risetime of 0.5 s, which increases to 1.5 s for the major slip areas removed from the hypocentral region. The energetic rupture phase is also shown to be the primary source of high-frequency radiation (1-15 Hz) by an inversion of acceleration envelopes. The same global search algorithm is used in the envelope inversion to calculate high-frequency radiation intensity on the fault and rupture time. The rupture timing from the low- and high-frequency inversions is similar, indicating that the high frequencies are produced primarily at the mainshock rupture front. Two major sources of high-frequency radiation are identified within the energetic rupture phase, one at the hypocenter and another deep source to the west of the hypocenter. The source at the hypocenter is associated with the initiation of rupture and the breaking of a high-stress-drop asperity and the second is associated with stopping of the rupture in a westerly direction.

Epidemiological studies in high background radiation areas

International Nuclear Information System (INIS)

Akiba, Suminori

2012-01-01

Below the doses of 100-200 mSv of radiation exposure, no acute health effect is observed, and the late health effects such as cancer are yet unclear. The problems making the risk evaluation of low dose radiation exposure difficult are the fact that the magnitude of expected health effects are small even if the risk is assumed to increase in proportion to radiation doses. As a result, studies need to be large particular when dealing with rare disease such as cancer. In addition, the expected health effects are so small that they can easily be masked by lifestyles and environmental factors including smoking. This paper will discuss cancer risk possibly associated with low-dose and low-dose rate radiation exposure, describing epidemiological studies on the residents in the high-background radiation areas. (author)

The IAEA regional post-graduate educational course on radiation protection in Russia

International Nuclear Information System (INIS)

Alejnikov, V.E.; Ivanova, S.P.; Timoshenko, G.N.

1998-01-01

Basic information is presented on the IAEA Regional Post-Graduate Educational Course on Radiation Protection which was conducted in Russia in 1996 and was sponsored by the IAEA and organized in cooperation with the Government of Russia and the Joint Institute for Nuclear Research. (A.K.)

Radiation Build-Up Of High Energy Gamma In Shielding Of High Atomic Number

International Nuclear Information System (INIS)

Yuliati, Helfi; Akhadi, Mukhlis

2000-01-01

Research to observe effect of radiation build-up factor (b) in iron (Fe) and lead (Pb) for high energy gamma shielding from exp.137 Cs (E gamma : 662 keV) and exp.60 Co (E gamma : 1332 keV) sources has been carried out. Research was conducted bt counting of radiation intensity behind shielding with its thickness vary from 1 to 5 times of half value thickness (HVT). NaI (TI) detector which connected to multi channel analyzer (MCA) was used for the counting. Calculation result show that all of b value are near to 1 (b∼1) both for Fe and Pb. Without inserting b in calculation, from the experiment it was obtained HVT value of Fe for high gamma radiation of 662 and 1332 keV were : (12,94 n 0,03) mm and (17,33 n 0,01) mm with their deviation standards were 0,2% and 0,06% respectively. Value of HVT for Pb with the same energy were : (6,31 n 0,03) mm and (11,86 n 0,03) mm with their deviation standars were : 0,48% and 0,25% respectively. HVL concept could be applied directly to estimate shielding thickness of high atomic number of high energy gamma radiation, without inserting correction of radiation build-up factor

Analysis of waste compounds of Gauzama Crinita and high density PET reinforced by gamma radiation

International Nuclear Information System (INIS)

Gago, Javier; Ramos, Victor; Hernandez, Yuri; Montoya, Eduardo; Lopez, Alcides; Universidad Nacional de Ingenieria, Lima; Acevedo, Moises

2013-01-01

The reinforcing effects of gamma radiation in a high density polyethylene and wood waste white Bolaina (Guazuma crinita) compounds from Pucallpa region are presented. Samples were mixed with maleic anhydride and extruded at a temperature between 170 and 200 °C, yielding small cylindrical pellets; were subsequently pressed through thermic process between 180 and 200 °C, in a time range between 15 to 20 minutes. The produced samples were exposed to gamma radiation between 50 and 300 kGy, and then subjected to mechanical testing of hardness and roughness. It was observed that the hardness and the roughness increases in direct proportion to the increase of the dose of gamma radiation, but the samples subjected to doses in the range of 100 to 150 kGy, had a slight inverse behavior. (authors).

High-energy outer radiation belt dynamic modeling

International Nuclear Information System (INIS)

Chiu, Y.T.; Nightingale, R.W.; Rinaldi, M.A.

1989-01-01

Specification of the average high-energy radiation belt environment in terms of phenomenological montages of satellite measurements has been available for some time. However, for many reasons both scientific and applicational (including concerns for a better understanding of the high-energy radiatino background in space), it is desirable to model the dynamic response of the high-energy radiation belts to sources, to losses, and to geomagnetic activity. Indeed, in the outer electron belt, this is the only mode of modeling that can handle the large intensity fluctuations. Anticipating the dynamic modeling objective of the upcoming Combined Release and Radiation Effects Satellite (CRRES) program, we have undertaken to initiate the study of the various essential elements in constructing a dynamic radiation belt model based on interpretation of satellite data according to simultaneous radial and pitch-angle diffusion theory. In order to prepare for the dynamic radiation belt modeling based on a large data set spanning a relatively large segment of L-values, such as required for CRRES, it is important to study a number of test cases with data of similar characteristics but more restricted in space-time coverage. In this way, models of increasing comprehensiveness can be built up from the experience of elucidating the dynamics of more restrictive data sets. The principal objectives of this paper are to discuss issues concerning dynamic modeling in general and to summarize in particular the good results of an initial attempt at constructing the dynamics of the outer electron radiation belt based on a moderately active data period from Lockheed's SC-3 instrument flown on board the SCATHA (P78-2) spacecraft. Further, we shall discuss the issues brought out and lessons learned in this test case

Compatibility of advanced tokamak plasma with high density and high radiation loss operation in JT-60U

International Nuclear Information System (INIS)

Takenaga, H.; Asakura, N.; Kubo, H.; Higashijima, S.; Konoshima, S.; Nakano, T.; Oyama, N.; Ide, S.; Fujita, T.; Takizuka, T.; Kamada, Y.; Miura, Y.; Porter, G.D.; Rognlien, T.D.; Rensink, M.E.

2005-01-01

Compatibility of advanced tokamak plasmas with high density and high radiation loss has been investigated in both reversed shear (RS) plasmas and high β p H-mode plasmas with a weak positive shear on JT-60U. In the RS plasmas, the operation regime is extended to high density above the Greenwald density (n GW ) with high confinement (HH y2 >1) and high radiation loss fraction (f rad >0.9) by tailoring the internal transport barriers (ITBs). High confinement of HH y2 =1.2 is sustained even with 80% radiation from the main plasma enhanced by accumulated metal impurity. The divertor radiation is enhanced by Ne seeding and the ratio of the divertor radiation to the total radiation is increased from 20% without seeding to 40% with Ne seeding. In the high β p H-mode plasmas, high confinement (HH y2 =0.96) is maintained at high density (n-bar e /n GW =0.92) with high radiation loss fraction (f rad ∼1) by utilizing high-field-side pellets and Ar injections. The high n-bar e /n GW is obtained due to a formation of clear density ITB. Strong core-edge parameter linkage is observed, as well as without Ar injection. In this linkage, the pedestal β p , defined as β p ped =p ped /(B p 2 /2μ 0 ) where p ped is the plasma pressure at the pedestal top, is enhanced with the total β p . The radiation profile in the main plasma is peaked due to Ar accumulation inside the ITB and the measured central radiation is ascribed to Ar. The impurity transport analyses indicate that Ar accumulation by a factor of 2 more than the electron, as observed in the high β p H-mode plasma, is acceptable even with peaked density profile in a fusion reactor for impurity seeding. (author)

Epidemiological studies in high-background radiation areas its potential contribution to evaluating risk of low-level radiation

International Nuclear Information System (INIS)

Akiba, Suminori; Nair, R.K.; Nakamura, Seiichi; Mizuno, Shoich

2008-01-01

The health effect of low-level ionizing radiation is yet unclear. As pointed out by Upton in his review (Upton, 1989), low-level ionizing radiation seems to have different biological effects from what high-level radiation has. Its evaluation requires epidemiological studies of scale-large cohorts (ICRP 99, 2005) such of atomic bomb survivors and nuclear workers. Epidemiological studies in high-background radiation (HBR) areas are also expected to make a significant contribution toward this end. Among several HBR areas in the world, Yangjiang, Guangdong Province in China, Karunagappally in Kerala State of India, Manawalakurichi and Koodankulam in Tamil Nadu of India, and Ramsar in Iran are important areas where epidemiological studies are possible, because of their relatively high background radiation levels and large population sizes. (author)

Radiation shielding

International Nuclear Information System (INIS)

Aitken, D.

1979-01-01

Shields for equipment in which ionising radiation is associated with high electrical gradients, for example X-ray tubes and particle accelerators, incorporate a radiation-absorbing metal, as such or as a compound, and are electrically non-conducting and can be placed in the high electrical gradient region of the equipment. Substances disclosed include dispersions of lead, tungsten, uranium or oxides of these in acrylics polyesters, PVC, ABS, polyamides, PTFE, epoxy resins, glass or ceramics. The material used may constitute an evacuable enclosure of the equipment or may be an external shield thereof. (U.K.)

Some techniques and results from high-pressure shock-wave experiments utilizing the radiation from shocked transparent materials

International Nuclear Information System (INIS)

McQueen, R.G.; Fritz, J.N.

1981-01-01

It has been known for many years that some transparent materials emit radiation when shocked to high pressures. This property was used to determine the temperature of shocked fused and crystal quartz, which in turn allowed the thermal expansion of SiO 2 at high pressure and also the specific heat to be calculated. Once the radiative energy as a function of pressure is known for one material it is shown how this can be used to determine the temperature of other transparent materials. By the nature of the experiments very accurate shock velocities can be measured and hence high quality equation of state data obtained. Some techniques and results are presented on measuring sound velocities from symmetrical impact of nontransparent materials using radiation emitting transparent analyzers, and on nonsymmetrical impact experiments on transparent materials. Because of special requirements in the later experiments, techniques were developed that lead to very high-precision shock-wave data. Preliminary results, using these techniques are presented for making estimates of the melting region and the yield strength of some metals under strong shock conditions

Chromosome Aberration on High Level Background Natural Radiation Areas

International Nuclear Information System (INIS)

Yanti-Lusiyanti; Zubaidah-Alatas

2001-01-01

When the body is irradiated, all cells can suffer cytogenetic damage that can be seen as structural damage of chromosome in the lymphocytes. People no matter where they live in world are exposed to background radiation from natural sources both internal and external such as cosmic radiation, terrestrial radiation, cosmogenic radiation radon and thoron. Level of area natural ionizing radiation is varies depending on the altitude, the soil or rock conditions, particular food chains and the building materials and construction features. Level of normal areas of background exposure is annual effective dose 2.4 mSv and the high level areas of background exposure 20 mSv. This paper discuses the frequency of aberration chromosome especially dysenteries in several countries having high level radiation background. It seems that frequency of chromosome aberrations increase, generally with the increase of age of the people and the accumulated dose received. (author)

Anticoagulation and high dose liver radiation. A preliminary report

International Nuclear Information System (INIS)

Lightdale, C.J.; Wasser, J.; Coleman, M.; Brower, M.; Tefft, M.; Pasmantier, M.

1979-01-01

Two groups of patients were observed for evidence of acute radiation hepatitis during high dose radiation to the liver. The first group of 18 patients with metastatic liver disease received an average of 4,050 rad to the whole liver. Half received anticoagulation with warfarin. One patient on anticoagulation developed evidence of acute radiation hepatitis while 2 patients did so without anticoagulation. Eleven patients with Hodgkin's disease received 4,000 rad to the left lobe of the liver during extended field radiation. Four of these 11 patients were anticoagulated to therapeutic range. Only one of the fully anticoagulated patients showed changes on liver scan consistent with radiation hepatitis whereas three did so without anticoagulation. No serious sequelae from anticoagulation occurred in either group. These preliminary data suggest that anticoagulation may be safely administered with high dose hepatic radiation and that further trials with anticoagulation are warranted

Loss and source mechanisms of Jupiter's radiation belts near the inner boundary of trapping regions

Science.gov (United States)

Santos-Costa, Daniel; Bolton, Scott J.; Becker, Heidi N.; Clark, George; Kollmann, Peter; Paranicas, Chris; Mauk, Barry; Joergensen, John L.; Adriani, Alberto; Thorne, Richard M.; Bagenal, Fran; Janssen, Mike A.; Levin, Steve M.; Oyafuso, Fabiano A.; Williamson, Ross; Adumitroaie, Virgil; Ingersoll, Andrew P.; Kurth, Bill; Connerney, John E. P.

2017-04-01

We have merged a set of physics-based and empirical models to investigate the energy and spatial distributions of Jupiter's electron and proton populations in the inner and middle magnetospheric regions. Beyond the main source of plasma (> 5 Rj) where interchange instability is believed to drive the radial transport of charged particles, the method originally developed by Divine and Garrett [J. Geophys. Res., 88, 6889-6903, 1983] has been adapted. Closer to the planet where field fluctuations control the radial transport, a diffusion theory approach is used. Our results for the equatorial and mid-latitude regions are compared with Pioneer and Galileo Probe measurements. Data collected along Juno's polar orbit allow us to examine the features of Jupiter's radiation environment near the inner boundary of trapping regions. Significant discrepancies between Juno (JEDI keV energy particles and high energy radiation environment measurements made by Juno's SRU and ASC star cameras and the JIRAM infrared imager) and Galileo Probe data sets and models are observed close to the planet. Our simulations of Juno MWR observations of Jupiter's electron-belt emission confirm the limitation of our model to realistically depict the energy and spatial distributions of the ultra-energetic electrons. In this paper, we present our modeling approach, the data sets and resulting data-model comparisons for Juno's first science orbits. We describe our effort to improve our models of electron and proton belts. To gain a physical understanding of the dissimilarities with observations, we revisit the magnetic environment and the mechanisms of loss and source in our models.

Analysis of population dosimetry data in the high level natural radiation areas, Kerala, India

International Nuclear Information System (INIS)

Chougaonkar, M.P.; Mayya, Y.S.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.; Eappen, K.P.; Ramachandran, T.V.; Jojo, P.J.; Predeep, P.

2010-01-01

In the Indian scenario, Kerala has huge monazite bearing sand deposits on the west coast thereby having high natural background radiation levels. Extensive studies on the radiation dosimetry as well as effects on the human health are therefore being carried out in the region. We have recently completed a dosimetric survey aimed for epidemiological studies using case control methodology. This study, in collaboration with two local colleges in Kollam, Kerala, was taken up to study the relationship of congenital malformations and radiation exposures, if any. The two conditions that were selected were mental retardation and cleft lip-palate. Stringent selection criteria were set in selecting the cases and suitable controls. A ratio of 1:3 for case:control was selected for getting the optimum statistical significance from the data generated. The paper describes the methodology of dosimetric survey and the analysis of dose data based on case and controls

A characteristics of East Asian climate using high-resolution regional climate model

Science.gov (United States)

Yhang, Y.

2013-12-01

Climate research, particularly application studies for water, agriculture, forestry, fishery and energy management require fine scale multi-decadal information of meteorological, oceanographic and land states. Unfortunately, spatially and temporally homogeneous multi-decadal observations of these variables in high horizontal resolution are non-existent. Some long term surface records of temperature and precipitation exist, but the number of observation is very limited and the measurements are often contaminated by changes in instrumentation over time. Some climatologically important variables, such as soil moisture, surface evaporation, and radiation are not even measured over most of East Asia. Reanalysis is one approach to obtaining long term homogeneous analysis of needed variables. However, the horizontal resolution of global reanalysis is of the order of 100 to 200 km, too coarse for many application studies. Regional climate models (RCMs) are able to provide valuable regional finescale information, especially in regions where the climate variables are strongly regulated by the underlying topography and the surface heterogeneity. In this study, we will provide accurately downscaled regional climate over East Asia using the Global/Regional Integrated Model system [GRIMs; Hong et al. 2013]. A mixed layer model is embedded within the GRIMs in order to improve air-sea interaction. A detailed description of the characteristics of the East Asian summer and winter climate will be presented through the high-resolution numerical simulations. The increase in horizontal resolution is expected to provide the high-quality data that can be used in various application areas such as hydrology or environmental model forcing.

Regional radiative impacts of mixed dust and carbonaceous aerosols over West Africa

Science.gov (United States)

Malavelle, Florent; Pont, Véronique; Solmon, Fabien; Mallet, Marc; Léon, Jean-François; Liousse, Catherine; Johnson, Ben

2010-05-01

Africa is a major source of aerosols at global scale. Two types of aerosols dominate the regional background: biomass burning aerosols as results of combustion of the vegetation and mineral dust aerosols related to erosion of arid soils by wind. These important burdens of aerosols are known to have each one a strong impact on the regional radiative budget. Whereas recent modelling efforts show significant impacts at climatic timescale on West African Monsoon due to the radiative effects of dust aerosols (see Solmon et al 2008 in GRL and references therein), biomass burning radiative effects in this region stand still poorly documented. What about West Africa, during the dry season (december-february) when both biomass burning and dust aerosols are encountered in the atmospheric background ? In that frame, we use ICTP Regional Climate Model versions 3 in order to estimate the radiative forcing due to the external mixing of mineral dust and carbonaceous aerosols from biomass burning, BioFuel and Fossil Fuel combustion during the dry season. Emissions of biomass burning aerosols are taken from new inventories based on SPOT vegetation burnt area products. Optical properties of carboneaceous aerosols are updated thanks to chemical sampling at Djougou during AMMA SOP-0. This presentation focuses on the model efficiency to correctly reproduce the main features concerning aerosols observed during AMMA-SOP0/DABEX field campaigns. It refers to (i) a strong stratification of dust and smoke layers, and (ii) a marked seasonal cycle of aerosol mixture optical properties. Those features are key parameters for modelling the direct and semi direct effects of aerosols over West Africa. Results of simulations indicate that the particular low value of single scattering albedo (SSA) for biomass burning aerosols (~0.81 at 550nm) involves important diabatic heating in the atmosphere. Values of aerosol heating rates are estimated and compared with aircraft measurement from DABEX

Modeling solar radiation of Mediterranean region in Turkey by using fuzzy genetic approach

International Nuclear Information System (INIS)

Kisi, Ozgur

2014-01-01

The study investigates the ability of FG (fuzzy genetic) approach in modeling solar radiation of seven cities from Mediterranean region of Anatolia, Turkey. Latitude, longitude, altitude and month of the year data from the Adana, K. Maras, Mersin, Antalya, Isparta, Burdur and Antakya cities are used as inputs to the FG model to estimate one month ahead solar radiation. FG model is compared with ANNs (artificial neural networks) and ANFIS (adaptive neruro fuzzzy inference system) models with respect to RMSE (root mean square errors), MAE (mean absolute errors) and determination coefficient (R 2 ) statistics. Comparison results indicate that the FG model performs better than the ANN and ANFIS models. It is found that the FG model can be successfully used for estimating solar radiation by using latitude, longitude, altitude and month of the year information. FG model with RMSE = 6.29 MJ/m 2 , MAE = 4.69 MJ/m 2 and R 2 = 0.905 in the test stage was found to be superior to the optimal ANN model with RMSE = 7.17 MJ/m 2 , MAE = 5.29 MJ/m 2 and R 2 = 0.876 and ANFIS model with RMSE = 6.75 MJ/m 2 , MAE = 5.10 MJ/m 2 and R 2 = 0.892 in estimating solar radiation. - Highlights: • SR (Solar radiation) of seven cities from Mediterranean region of Turkey is predicted. • FG (Fuzzy genetic) models are developed for accurately estimation of SR. • The ability of the FG models used in the study is found to be satisfactory. • FG models are compared with commonly used ANNs (artificial neural networks). • FG models are found to perform better than the ANNs models

Regional radiation protection center in the Federal Republic of Germany - Tasks and Organization

International Nuclear Information System (INIS)

Koelzer, W.

1988-01-01

In the Federal Republic of Germany 220,000 staff members are classified at the moment as occupationally radiation exposed persons. For the maintenance of industrial health and safety for the workers in the companies and for the medical, professional and social rehabilitaion after an accident the so-called ''Berufsgenossenschaften'' (professional trade associations) are responsible. For employees in nuclear industry two trade associations are competent: - the Trade Association for Precision Engineering and Electrical Engineering for the 6,000 employees in nuclear power plants, - the Trade Association of the Chemical Industry for the 4,000 employees in fuel element fabrication and the reprocessing companies. In case of an accident workers from service companies e.g. construction and installation companies could be affected as well. Therefore these trade associations have founded a couple of years ago an ''Institute for Radiation Protection''. A special task of this institute is First Aid to overexposed people in case of radiation accidents. In addition, it organizes the 24-hours-service of the seven Regional Radiation Protection Centers of Federal Republic of Germany. The institute provides special training of radiation protection physicians and occupationally radiation exposed persons. (author) [pt

A high precision radiation-tolerant LVDT conditioning module

Energy Technology Data Exchange (ETDEWEB)

Masi, A. [EN/STI Group, CERN - European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Danzeca, S. [EN/STI Group, CERN - European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); IES, F-34000 Montpellier (France); Losito, R.; Peronnard, P. [EN/STI Group, CERN - European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Secondo, R., E-mail: raffaello.secondo@cern.ch [EN/STI Group, CERN - European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Spiezia, G. [EN/STI Group, CERN - European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland)

2014-05-01

Linear variable differential transformer (LVDT) position sensors are widely used in particle accelerators and nuclear plants, thanks to their properties of contact-less sensing, radiation tolerance, infinite resolution, good linearity and cost efficiency. Many applications require high reading accuracy, even in environments with high radiation levels, where the conditioning electronics must be located several hundred meters away from the sensor. Sometimes even at long distances the conditioning module is still exposed to ionizing radiation. Standard off-the-shelf electronic conditioning modules offer limited performances in terms of reading accuracy and long term stability already with short cables. A radiation tolerant stand-alone LVDT conditioning module has been developed using Commercial Off-The-Shelf (COTS) components. The reading of the sensor output voltages is based on a sine-fit algorithm digitally implemented on an FPGA ensuring few micrometers reading accuracy even with low signal-to-noise ratios. The algorithm validation and board architecture are described. A full metrological characterization of the module is reported and radiation tests results are discussed.

Radiative Forcing from Emissivity Response in Polar Regions

Science.gov (United States)

Kuo, C.; Feldman, D.; Huang, X.; Flanner, M.; Chen, X.; Yang, P.; Kuo, C.

2016-12-01

A detailed assessment of the radiative balance and its controlling factors in polar regions is a critical prerequisite for understanding and predicting the polar amplification of climate change. Accordingly, we investigate the role of infrared surface emissivity in polar regions as a potential feedback mechanism following Feldman et al, 2014. In this work, we investigate the climatic response of the Community Earth System Model (CESM) with spectral emissivity values that are implemented in a physically consistent manner for non-vegetated surfaces. In a control model run where 1850 CO2 volume mixing ratio (vmr) is fixed, the updated spectral emissivity values are imposed for modified surface boundary conditions in the atmospheric model component. Climatic stability in the emergent globally averaged surface temperature is observed on decadal scales for an unforced (control) run. Analytic kernels representing the change in top of the atmosphere OLR given changes in emissivity are calculated on-line during the model runs, incorporating spatially and temporally varied humidity profiles impactful to transmission. Globally averaged kernels of the sensitivity of OLR to surface emissivity calculated for control and ramped CO2 runs exhibit temporal evolution with statistically significant differences in shape. Additionally, kernel and spectrally-averaged emissivity differences between monthly-averaged maps of control and ramped runs demonstrate a seasonal cycle. Similar to the treatment of cryosphere radiative forcing in Flanner et al, 2011, we define emissivity response as the product of the emissivity kernel and the change in month-to-month emissivity. At the end of 20th century, the 10-year emissivity forcing averaged at latitudes > 60°, is found to be negative (positive) in January (July), due to increasing (decreasing) sea-ice. These findings indicate that differences in surface emissivity between frozen and unfrozen surfaces decrease wintertime and increase summertime

Response of high Tc superconducting Josephson junction to nuclear radiation

International Nuclear Information System (INIS)

Ding Honglin; Zhang Wanchang; Zhang Xiufeng

1992-10-01

The development of nuclear radiation detectors and research on high T c superconducting nuclear radiation detectors are introduced. The emphases are the principle of using thin-film and thick-film Josephson junctions (bridge junction) based on high T c YBCO superconductors to detect nuclear radiation, the fabrication of thin film and thick-film Josephson junction, and response of junction to low energy gamma-rays of 59.5 keV emitted from 241 Am and beta-rays of 546 keV. The results show that a detector for measuring nuclear radiation spectrum made of high T c superconducting thin-film or thick-film, especially, thick-film Josephson junction, certainly can be developed

Public meeting on radiation safety for industrial radiographerss: remarks, questions and answers at five NRC regional meetings

International Nuclear Information System (INIS)

1978-11-01

Over the past several years thenumber of radiation overexposures experienced in the radiography industry has been higher than for any other single group of NRC licensees. To inform radiography licensees of NRC's concern fo these recurring overexposure incidents, NRC staff representatives met with licensees in a series of five regional meetings. At these meetings the staff presented prepared remarks and answered questions on NRC regulations and operations. The main purposes of the meetings were to express NRC's concern for the high incidence of overexposures, and to open a line of communication between the NRC and radiography licensees in an effort to achieve the common goal of improved radiation safety. The remarks presented by the staff and subjects discussed at these meetings included: the purpose, scope, findings and goals of the NRC inspection program; ways and means of incorporating safety into radiography operations; and case histories of overexposure incidents, with highlights of the causes and possible preventions. At each of the regional meetings the staff received a request for a copy of the prepared remarks and a consolidation of the questions and answers that were discussed. This document includes that information, and a copy is being provided to each organizaion or firm attending the regional meetings. Requests for other copies should be made in accordance with the directions printed inside the front cover of this document

Transport analysis of high radiation and high density plasmas in the ASDEX Upgrade tokamak

Directory of Open Access Journals (Sweden)

Casali L.

2014-01-01

Full Text Available Future fusion reactors, foreseen in the “European road map” such as DEMO, will operate under more demanding conditions compared to present devices. They will require high divertor and core radiation by impurity seeding to reduce heat loads on divertor target plates. In addition, DEMO will have to work at high core densities to reach adequate fusion performance. The performance of fusion reactors depends on three essential parameters: temperature, density and energy confinement time. The latter characterizes the loss rate due to both radiation and transport processes. The DEMO foreseen scenarios described above were not investigated so far, but are now addressed at the ASDEX Upgrade tokamak. In this work we present the transport analysis of such scenarios. Plasma with high radiation by impurity seeding: transport analysis taking into account the radiation distribution shows no change in transport during impurity seeding. The observed confinement improvement is an effect of higher pedestal temperatures which extend to the core via stiffness. A non coronal radiation model was developed and compared to the bolometric measurements in order to provide a reliable radiation profile for transport calculations. High density plasmas with pellets: the analysis of kinetic profiles reveals a transient phase at the start of the pellet fuelling due to a slower density build up compared to the temperature decrease. The low particle diffusion can explain the confinement behaviour.

Use of synchrotron radiation in radiation biology research

International Nuclear Information System (INIS)

Yamada, Takeshi

1981-01-01

Synchrotron radiation (SR) holds great expectation as a new research tool in the new areas of material science, because it has the continuous spectral distribution from visible light to X-ray, and its intensity is 10 2 to 10 3 times as strong as that of conventional radiation sources. In the National Laboratory for High Energy Physics, a synchrotron radiation experimental facility has been constructed, which will start operation in fiscal 1982. With this SR, the photons having the wavelength in undeveloped region from vacuum ultraviolet to soft X-ray are obtained as intense mono-wavelength light. The SR thus should contribute to the elucidation of the fundamentals in the biological action of radiation. The following matters are described: synchrotron radiation, experimental facility using SR, electron storage ring, features of SR, photon factory plan and synchrotron radiation experimental facility, utilization of SR in radiation biology field. (J.P.N.)

Combined neck dissection and postoperative radiation therapy in the management of the high-risk neck: a matched-pair analysis

International Nuclear Information System (INIS)

Lundahl, Robert E.; Foote, Robert L.; Bonner, James A.; Suman, Vera J.; Lewis, Jean E.; Kasperbauer, Jan L.; McCaffrey, Thomas V.; Olsen, Kerry D.

1998-01-01

Purpose: The purpose of this study was to determine the efficacy of postoperative adjuvant radiation therapy with regard to reducing the rate of recurrence in the neck, cancer-related death, and death from any cause in patients with squamous cell carcinoma of the head and neck region metastatic to neck nodes. Methods: This was a retrospective review of patients with pathologically confirmed nodal metastases who underwent neck dissection and postoperative adjuvant radiation therapy for squamous cell carcinoma of the head and neck region. Time to recurrence in the dissected area of the neck, any recurrence in the neck, cancer-related death, and death from any cause were estimated with the Kaplan-Meier method. A matched-pair analysis was performed utilizing a cohort of patients who underwent neck dissection without postoperative radiation therapy. The patients from the two cohorts were matched according to previously reported high-risk features for cancer recurrence and death. Cox hazards models for the matched pairs were used to evaluate the relative risk of subsequent recurrence in the dissected side of the neck, any neck recurrence, cancer-related death, and overall survival. Materials: The medical records and pathologic slides of 95 consecutive patients with pathologically confirmed nodal metastases from squamous cell carcinoma of the head and neck region who underwent neck dissection and postoperative adjuvant radiation therapy between January 1974 and December 1990 were reviewed. Previously published data from 284 patients with squamous cell carcinoma of the head and neck region treated with neck dissection alone between January 1970 and December 1980 were used for a matched-pair analysis. Results: The relative risks for recurrence in the dissected side of the neck, any neck recurrence (dissected neck or delayed undissected neck metastasis), cancer-related death, and death from any cause for patients treated with operation alone relative to those treated with

A high precision radiation-tolerant LVDT conditioning module

CERN Document Server

Masi, A; Losito, R; Peronnard, P; Secondo, R; Spiezia, G

2014-01-01

Linear variable differential transformer (LVDT) position sensors are widely used in particle accelerators and nuclear plants, thanks to their properties of contact-less sensing, radiation tolerance, infinite resolution, good linearity and cost efficiency. Many applications require high reading accuracy, even in environments with high radiation levels, where the conditioning electronics must be located several hundred meters away from the sensor. Sometimes even at long distances the conditioning module is still exposed to ionizing radiation. Standard off-the-shelf electronic conditioning modules offer limited performances in terms of reading accuracy and long term stability already with short cables. A radiation tolerant stand-alone LVDT conditioning module has been developed using Commercial Off-The-Shelf (COTS) components. The reading of the sensor output voltages is based on a sine-fit algorithm digitally implemented on an FPGA ensuring few micrometers reading accuracy even with low signal-to-noise ratios. ...

High-power beam-based coherently enhanced THz radiation source

Directory of Open Access Journals (Sweden)

Yuelin Li (李跃林

2008-08-01

Full Text Available We propose a compact Smith-Purcell radiation device that can potentially generate high average power THz radiation with high conversion efficiency. The source is based on a train of short electron bunches from an rf photoemission gun at an energy of a few MeV. Particle tracking simulation and analysis show that, with a beam current of 1 mA, it is feasible to generate hundreds of watts of narrow-band THz radiation at a repetition rate of 1 MHz.

The formation of ozone and UV radiation from high-power pulsed electric discharges

Science.gov (United States)

Piskarev, I. M.; Ushkanov, V. A.; Selemir, V. D.; Spirov, G. M.; Malevannaya Pikar', I. A.; Zuimach, E. A.

2008-09-01

High-power electric discharges with pulse energies of from 0.15 J to 4 kJ were studied. The yields of UV photons and ozone were found to be approximately equal, which led us to conclude that discharge conditions under which UV radiation and ozone fully destroyed each other were possible. If ozone formation was suppressed, as when a negative volume charge was created in the spark gap region, the flux of UV photons reached 3 × 1023 photons/(cm2 s).

High LET radiation and mechanism of DNA damage repair

International Nuclear Information System (INIS)

Furusawa, Yoshiya

2004-01-01

Clarifying the mechanism of repair from radiation damage gives most important information on radiation effects on cells. Approximately 10% of biological experiments groups in Heavy Ion Medical Accelerator in Chiba (HIMAC) cooperative research group has performed the subject. They gave a lot of new findings on the mechanism, and solved some open questions. The reason to show the peak of relative biological effectiveness RBE at around 100-200 keV/μm causes miss-repair of DNA damage. Sub-lethal damage generated by high linear energy transfer (LET) radiation can be repaired fully. Potentially lethal damages by high-LET radiation also repaired, but the efficiency decreased with the LET, and so on. (author)

World high background natural radiation areas: Need to protect public from radiation exposure

International Nuclear Information System (INIS)

Sohrabi, Mehdi

2013-01-01

Highlights of findings on radiological measurements, radiobiological and epidemiological studies in some main world high background natural radiation (HBNR) areas such as in Brazil, China, India and Iran are presented and discussed with special regard to remediation of radiation exposure of inhabitants in such areas. The current radiation protection philosophy and recommendations applied to workers and public from operation of radiation and nuclear applications are based on the linear non-threshold (LNT) model. The inhabitants of HBNR and radon prone areas receive relatively high radiation doses. Therefore, according to the LNT concept, the inhabitants in HBNR areas and in particular those in Ramsar are considered at risk and their exposure should be regulated. The HBNR areas in the world have different conditions in terms of dose and population. In particular, the inhabitants in HBNR areas of Ramsar receive very high internal and external exposures. This author believes that the public in such areas should be protected and proposes a plan to remedy high exposure of the inhabitants of the HBNR areas of Ramsar, while maintaining these areas as they stand to establish a national environmental radioactivity park which can be provisionally called “Ramsar Research Natural Radioactivity Park” (RRNRP). The major HBNR areas, the public exposure and the need to remedy exposures of inhabitants are reviewed and discussed. - Highlights: ► Highlights of findings on studies in HBNR areas are reviewed and discussed. ► The need to protect HBNR area inhabitants and remedy public exposure is emphasized. ► A collective approach is proposed to remedy exposure of Ramsar HBNR area inhabitants. ► Relocation of HBNR area inhabitants and establishing a park at the location is proposed. ► The advantages and disadvantages of the methods are discussed and recommendations are made

Radiation-hard silicon photonics for high energy physics and beyond

CERN Multimedia

CERN. Geneva

2016-01-01

Silicon photonics (SiPh) is currently being investigated as a promising technology for future radiation hard optical links. The possibility of integrating SiPh devices with electronics and/or silicon particle sensors as well as an expected very high resistance against radiation damage make this technology particularly interesting for potential use close to the interaction points in future in high energy physics experiments and other radiation-sensitive applications. The presentation will summarize the outcomes of the research on radiation hard SiPh conducted within the ICE-DIP projected.

Low dose radiation enhance the anti-tumor effect of high dose radiation on human glioma cell U251

International Nuclear Information System (INIS)

Wang Chang; Wang Guanjun; Tan Yehui; Jiang Hongyu; Li Wei

2008-01-01

Objective: To detect the effect on the growth of human glioma cell U251 induced by low dose irradiation and low dose irradiation combined with large dose irradiation. Methods: Human glioma cell line U251 and nude mice carried with human glioma were used. The tumor cells and the mice were treated with low dose, high dose, and low dose combined high dose radiation. Cells growth curve, MTT and flow cytometry were used to detect the proliferation, cell cycle and apoptosis of the cells; and the tumor inhibition rate was used to assess the growth of tumor in vivo. Results: After low dose irradiation, there was no difference between experimental group and control group in cell count, MTT and flow cytometry. Single high dose group and low dose combined high dose group both show significantly the suppressing effect on tumor cells, the apoptosis increased and there was cell cycle blocked in G 2 period, but there was no difference between two groups. In vivo apparent anti-tumor effect in high dose radiation group and the combining group was observed, and that was more significant in the combining group; the prior low dose radiation alleviated the injury of hematological system. There was no difference between single low dose radiation group and control. Conclusions: There is no significant effect on human glioma cell induced by low dose radiation, and low dose radiation could not induce adaptive response. But in vivo experience, low dose radiation could enhance the anti-tumor effect of high dose radiation and alleviated the injury of hematological system. (authors)

Distributions of Low- and High-LET Radiation-Induced Breaks in Chromosomes are Associated with Inter- and Intrachromosome Exchanges

Science.gov (United States)

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

2010-01-01

To study the breakpoint along the length of the chromosome induced by low- and high-LET radiations, we exposed human epithelial cells in vitro to Cs-137 rays at both low and high dose rates, secondary neutrons at a low dose rate, and 600 MeV/u Fe ions at a high dose rate. The location of the breaks was identified using the multicolor banding in situ hybridization (mBAND) that paints Chromosome 3 in 23 different colored bands. The breakpoint distributions were found to be similar between rays of low and high dose rates and between the two high-LET radiation types. Detailed analysis of the chromosome break ends involved in inter- and intrachromosome exchanges revealed that only the break ends participating in interchromosome exchanges contributed to the hot spots found for low-LET. For break ends participating in intrachromosome exchanges, the distributions for all four radiation scenarios were similar with clusters of breaks found in three regions. Analysis of the locations of the two break ends in Chromosome 3 that joined to form an intrachromosome exchange demonstrated that two breaks with a greater genomic separation may be more likely to rejoin than two closer breaks, indicating that chromatin folding can play an important role in the rejoining of chromosome breaks. Our study demonstrated that the gene-rich regions do not necessarily contain more breaks. The breakpoint distribution depends more on the likelihood that a break will join with another break in the same chromosome or in a different chromosome.

High resolution X-ray fluorescence imaging for a microbeam radiation therapy treatment planning system

Science.gov (United States)

Chtcheprov, Pavel; Inscoe, Christina; Burk, Laurel; Ger, Rachel; Yuan, Hong; Lu, Jianping; Chang, Sha; Zhou, Otto

2014-03-01

Microbeam radiation therapy (MRT) uses an array of high-dose, narrow (~100 μm) beams separated by a fraction of a millimeter to treat various radio-resistant, deep-seated tumors. MRT has been shown to spare normal tissue up to 1000 Gy of entrance dose while still being highly tumoricidal. Current methods of tumor localization for our MRT treatments require MRI and X-ray imaging with subject motion and image registration that contribute to the measurement error. The purpose of this study is to develop a novel form of imaging to quickly and accurately assist in high resolution target positioning for MRT treatments using X-ray fluorescence (XRF). The key to this method is using the microbeam to both treat and image. High Z contrast media is injected into the phantom or blood pool of the subject prior to imaging. Using a collimated spectrum analyzer, the region of interest is scanned through the MRT beam and the fluorescence signal is recorded for each slice. The signal can be processed to show vascular differences in the tissue and isolate tumor regions. Using the radiation therapy source as the imaging source, repositioning and registration errors are eliminated. A phantom study showed that a spatial resolution of a fraction of microbeam width can be achieved by precision translation of the mouse stage. Preliminary results from an animal study showed accurate iodine profusion, confirmed by CT. The proposed image guidance method, using XRF to locate and ablate tumors, can be used as a fast and accurate MRT treatment planning system.

Radiation exposure and high-altitude flight. NCRP Commentary No. 12

International Nuclear Information System (INIS)

1995-01-01

Enhanced air crew and public radiation exposure while flying at current altitudes and speeds has not been adequately addressed. However, the commercial aircraft industry continues to expand with greater numbers of passengers and more air crews year by year. With the expected expansions in high-altitude flight in the next two decades there will be many more people exposed to higher levels of ionizing radiation than currently. The equivalent dose rates at the higher altitudes are of the order of two to three times those received at current aircraft altitudes, but are not known very well, partly because of limitations in the knowledge of the component radiations, especially the high-energy neutron component. The risks are also more uncertain than for low-LET exposures on the ground because of uncertainty in an average W R to use for high-LET radiations. Exposures of current air crew are presently comparable with the average exposures of other radiation workers on the ground (EPA, 1995). Substantially higher exposures must be expected at high altitudes to air crew (perhaps approaching or possibly exceeding the current limit for workers on the ground). Higher exposures to sensitive groups of the population such as the fetuses carried by pregnant women are of special concern. Therefore, steps must be taken to improve our knowledge base with respect to dose levels and risks at these high altitudes. Following acquisition of this knowledge, modifications in radiation protection practices with respect to air crew and passengers will need to be considered and recommended to assure that adequate radiation protection is provided with respect to high-altitude flight

High Temperature Radiators for Electric Propulsion Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The VASIMR propulsion system uses a high temperature Loop Heat Pipe (LHP) radiator to reject heat from the helicon section. The current baseline radiator uses...

Lightweight, High-Temperature Radiator for Space Propulsion

Science.gov (United States)

Hyers, R. W.; Tomboulian, B. N.; Crave, Paul D.; Rogers, J. R.

2012-01-01

For high-power nuclear-electric spacecraft, the radiator can account for 40% or more of the power system mass and a large fraction of the total vehicle mass. Improvements in the heat rejection per unit mass rely on lower-density and higher-thermal conductivity materials. Current radiators achieve near-ideal surface radiation through high-emissivity coatings, so improvements in heat rejection per unit area can be accomplished only by raising the temperature at which heat is rejected. We have been investigating materials that have the potential to deliver significant reductions in mass density and significant improvements in thermal conductivity, while expanding the feasible range of temperature for heat rejection up to 1000 K and higher. The presentation will discuss the experimental results and models of the heat transfer in matrix-free carbon fiber fins. Thermal testing of other carbon-based fin materials including carbon nanotube cloth and a carbon nanotube composite will also be presented.

Ionizing radiation measurements using low cost instruments for teaching in college or high-school in Brazil

Science.gov (United States)

Silva, M. C.; Vilela, D. C.; Migoto, V. G.; Gomes, M. P.; Martin, I. M.; Germano, J. S. E.

2017-11-01

Ionizing radiation one of modern physics experimental teaching in colleges and high school can be easily implemented today due to low coasts of detectors and also electronic circuits and data acquisition interfaces. First it is interesting to show to young’s students what is ionizing radiation and from where they appears near ground level? How it is possible to measure these radiations and how to check intensities variation during day, night, dry and wet periods in the same school? For increasing interest and stimulation in others students how to proceed in making the graphics of the ionizing radiation and presenting him in real time using Web internet facilities? Many others facilities like calibration of the detector using low intensities radioactive ionizing radiation sources, make comparison of the measurements and discussions of the results should be possible between many groups of students from several schools in the region of Brazil. This paper presents the experimental procedures including detectors and associated electronic including data acquisition, graphics elaboration and Web internet procedures to discuss and exchanging data measurements from several schools.

Radiation conditions is the region of Rovenskaya nuclear power plant construction

International Nuclear Information System (INIS)

Konstantinov, Yu.O.; Teplykh, A.A.; Kataev, V.T.; Dikaya, E.Ya.; Lisachenko, Eh.P.; Ponikarov, V.I.

1978-01-01

With a view to optimizing the monitoring of radiation conditions in the vicinity of NPP, an area extending 15-20 km around the construction site of the Rovenskaya atomic energy plant was surveyed. The level of natural gamma-radiation, contents of 90 Sr and 137 Cs in environmental objects, and doses of radiation received by the population from incorporated 137 Cs was studied. It was found that while the average natural gamma-radiation background was relatively low, local levels of the gamma background varied strongly with the type of soil and the pattern of housing systems in the human settlements concerned. The contents of 90 Sr and 137 Cs were also found to fluctuate considerably with the sampling site. 137 Cs was relatively high in cow's milk and in members of the community. The results obtained will be taken into account in the radiation monitoring program

ON RADIATION PRESSURE IN STATIC, DUSTY H II REGIONS

International Nuclear Information System (INIS)

Draine, B. T.

2011-01-01

Radiation pressure acting on gas and dust causes H II regions to have central densities that are lower than the density near the ionized boundary. H II regions in static equilibrium comprise a family of similarity solutions with three parameters: β, γ, and the product Q 0 n rms ; β characterizes the stellar spectrum, γ characterizes the dust/gas ratio, Q 0 is the stellar ionizing output (photons/s), and n rms is the rms density within the ionized region. Adopting standard values for β and γ, varying Q 0 n rms generates a one-parameter family of density profiles, ranging from nearly uniform density (small Q 0 n rms ) to shell-like (large Q 0 n rms ). When Q 0 n rms ∼> 10 52 cm -3 s -1 , dusty H II regions have conspicuous central cavities, even if no stellar wind is present. For given β, γ, and Q 0 n rms , a fourth quantity, which can be Q 0 , determines the overall size and density of the H II region. Examples of density and emissivity profiles are given. We show how quantities of interest-such as the peak-to-central emission measure ratio, the rms-to-mean density ratio, the edge-to-rms density ratio, and the fraction of the ionizing photons absorbed by the gas-depend on β, γ, and Q 0 n rms . For dusty H II regions, compression of the gas and dust into an ionized shell results in a substantial increase in the fraction of the stellar photons that actually ionize H (relative to a uniform-density H II region with the same dust/gas ratio and density n = n rms ). We discuss the extent to which radial drift of dust grains in H II regions can alter the dust-to-gas ratio. The applicability of these solutions to real H II regions is discussed.

Investigation of the continuum radiation from a high pressure argon arc

International Nuclear Information System (INIS)

Glasser, J.; Chapelle, J.

1975-01-01

At the high electronic densities existing in high temperature strongly correlated plasmas (with number of electrons in the Debye sphere Nd<<1) it is sometimes difficult to find lines for which Stark broadening allows determination of electronic density. Since the broadening effect is rather strong, the lines overlap or could not be easily extracted from the intense continuous background. The continuum emission in the UV, visible and near infra-red regions, principally due to the radiative recombination, could thus be widely used for the diagnostics of such plasmas. So far a limited number of data on the continuum emission of Argon plasma is available. At the same time certain discrepancies between theoretical predictions and experiments have also been found. The aim of this work is to obtain more elaborated data on the Argon continuum emission at high pressure, where the differences were found to be the largest. (Auth.)

Net radiative forcing and air quality responses to regional CO emission reductions

Directory of Open Access Journals (Sweden)

M. M. Fry

2013-05-01

Full Text Available Carbon monoxide (CO emissions influence global and regional air quality and global climate change by affecting atmospheric oxidants and secondary species. We simulate the influence of halving anthropogenic CO emissions globally and individually from 10 regions on surface and tropospheric ozone, methane, and aerosol concentrations using a global chemical transport model (MOZART-4 for the year 2005. Net radiative forcing (RF is then estimated using the GFDL (Geophysical Fluid Dynamics Laboratory standalone radiative transfer model. We estimate that halving global CO emissions decreases global annual average concentrations of surface ozone by 0.45 ppbv, tropospheric methane by 73 ppbv, and global annual net RF by 36.1 mW m−2, nearly equal to the sum of changes from the 10 regional reductions. Global annual net RF per unit change in emissions and the 100 yr global warming potential (GWP100 are estimated as −0.124 mW m−2 (Tg CO−1 and 1.34, respectively, for the global CO reduction, and ranging from −0.115 to −0.131 mW m−2 (Tg CO−1 and 1.26 to 1.44 across 10 regions, with the greatest sensitivities for regions in the tropics. The net RF distributions show widespread cooling corresponding to the O3 and CH4 decreases, and localized positive and negative net RFs due to changes in aerosols. The strongest annual net RF impacts occur within the tropics (28° S–28° N followed by the northern midlatitudes (28° N–60° N, independent of reduction region, while the greatest changes in surface CO and ozone concentrations occur within the reduction region. Some regional reductions strongly influence the air quality in other regions, such as East Asia, which has an impact on US surface ozone that is 93% of that from North America. Changes in the transport of CO and downwind ozone production clearly exceed the direct export of ozone from each reduction region. The small variation in CO GWPs among world regions suggests that future international

High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

Energy Technology Data Exchange (ETDEWEB)

Bizen, Teruhiko [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)]. E-mail: bizen@spring8.or.jp; Asano, Yoshihiro [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Marechal, Xavier-Marie [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Seike, Takamitsu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Aoki, Tsuyoshi [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Fukami, Kenji [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hosoda, Naoyasu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yonehara, Hiroto [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takagi, Tetsuya [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hara, Toru [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Tanaka, Takashi [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kitamura, Hideo [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2007-05-11

High-energy electron-beam bombardment of Nd{sub 2}Fe{sub 14}B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small.

High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

International Nuclear Information System (INIS)

Bizen, Teruhiko; Asano, Yoshihiro; Marechal, Xavier-Marie; Seike, Takamitsu; Aoki, Tsuyoshi; Fukami, Kenji; Hosoda, Naoyasu; Yonehara, Hiroto; Takagi, Tetsuya; Hara, Toru; Tanaka, Takashi; Kitamura, Hideo

2007-01-01

High-energy electron-beam bombardment of Nd 2 Fe 14 B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small

Hawking radiation of a high-dimensional rotating black hole

Energy Technology Data Exchange (ETDEWEB)

Zhao, Ren; Zhang, Lichun; Li, Huaifan; Wu, Yueqin [Shanxi Datong University, Institute of Theoretical Physics, Department of Physics, Datong (China)

2010-01-15

We extend the classical Damour-Ruffini method and discuss Hawking radiation spectrum of high-dimensional rotating black hole using Tortoise coordinate transformation defined by taking the reaction of the radiation to the spacetime into consideration. Under the condition that the energy and angular momentum are conservative, taking self-gravitation action into account, we derive Hawking radiation spectrums which satisfy unitary principle in quantum mechanics. It is shown that the process that the black hole radiates particles with energy {omega} is a continuous tunneling process. We provide a theoretical basis for further studying the physical mechanism of black-hole radiation. (orig.)

Adventitious X-radiation from high voltage equipment

International Nuclear Information System (INIS)

Martin, E.B.M.

1979-01-01

The monograph is concerned with hazards of unwanted x-rays from sources such as television receivers, high voltage equipment, radar transmitters, switchgear and electron beam apparatus for welding, evaporation, analysis and microscopy. Chapters are included on units, production of x radiation, biological effects, protection standards, radiation monitoring, shielding and control of access, medical and dosimetric supervision and types of equipment. A bibliography of 92 references and other cited literature is included. (U.K.)

Electromagnetic radiation properties of foods and agricultural products

International Nuclear Information System (INIS)

Mohsenin, N.N.

1984-01-01

In this book, the author examines the effects of the various regions of the electromagnetic radiation spectrum on foods and agricultural products. Among the regions of the electromagnetic radiation spectrum covered are high-energy beta and neutron particles, gamma-rays and X-rays, to lower-energy visible, near infrared, infrared, microwave and low-energy radiowaves and electric currents. Dr. Mohsenin applies these electromagnetic phenomena to food products such as fruits, vegetables, seeds, dairy products, meat and processed foods. Contents: Some Basic Concepts of Electromagnetic Radiation. Basic Instruments for Measurement of Optical Properties. Applications of Radiation in the Visible Spectrum. Color and its Measurement. Sorting for Color and Appearance. Near-Infrared and Infrared Radiation Applications. Applications of High-Energy Radiation. Related Concepts of Microwaves, Radiowaves, and Electric Currents. Measurement of Electrical Properties of Foods and Agricultural Products. Applications of Electrical Properties. Appendix, Cited References. Subject Index

An analysis of the awareness and performance of radiation workers' radiation/radioactivity protection in medical institutions : Focused on Busan regional medical institutions

International Nuclear Information System (INIS)

Park, Cheol Koo; Hwang, Chul Hwan; Kim, Dong Hyun

2017-01-01

The purpose of this study was to investigate safety management awareness and behavioral investigation of radiation/radioactivity performance defenses of radiation workers' in medical institutions. Data collection consisted of 267 radiation workers working in medical institutions using structured questionnaires. As a result, it was analyzed that radiation safety management awareness and performance were high in 40s, 50s group and higher education group. The analysis according to the radiation safety management knowledge was analyzed that the 'Know very well' group had higher scores on awareness and performance scores. The analysis according to the degree of safety management effort showed the high awareness scale and the performance scale in the group 'Receiving various education or studying the safety management contents through book'. The correlations between the sub-factors showed the highest positive correlation between perceived practician and personal perspective and perceived by patient and patient's caretaker perspective. Therefore, radiation safety management for workers, patients, and patient's caretaker should be conducted through continuous education of radiation safety management through various routes of radiation workers working at medical institutions

HYGIENIC AND SANITARY-EDUCATIONAL BASICS OF THE RADIATION ANXIETY PREVENTION AMONG THE POPULATION IN THE REGIONS WITH NUCLEAR-ENERGY COMPLEX ENTERPRISES

Directory of Open Access Journals (Sweden)

Shevchenko O. A.

2017-12-01

Full Text Available Background. The development of nuclear power in the countries affected by the Chernobyl accident is accompanied by a high level of radiation anxiety among the local population. The purpose of the work is the scientific substantiation of methodological approaches to determine the level and prevalence of radiation anxiety among residents of regions with enterprises of the nuclear power complex, and the development of a system of measures for their prevention. Material and methods. The features of the subjective assessment of the health and psychological status of residents of the cities of Kirovograd, ZholtyeVody (n = 387 and Volnogorsk (control group, n = 208 were studied. An original method was developed to determine the level of radiation anxiety by qualitative characteristics. Results. A low level of radiation anxiety was found in 52.5% of respondents, an average – in 27.6%, a high level – in 3.9%, it directly correlated with self-esteem of the state of health (rs = 0.134; p <0.10, presence of oncological pathologies in family (rs = 0.209, p <0.001 and the respondent's conviction that there is a direct relationship between cancer and radiation (rs = 0.302, p <0.001. Conclusions. The developed method makes it possible to determine the respondents' attitude to the problem of the effect of ionizing radiation on the health status and group people according to the level of anxiety for further planning of health improvement measures.

Production of Elephant Trunks in HII Regions by Radiation-Magnetohydrodynamic Instabilities

OpenAIRE

Fierlinger, Katharina; Krumholz, Mark; Grittschneder, Matthias

2010-01-01

Recent SPH and grid code simulations showed, that ionizing radiation can amplify overdensities in turbulent molecular clouds and produce molecular pillars. The relevance of magnetic fields for the structure and stability of molecular clouds is still under discussion. We investigate whether an ionization front hitting a medium with small distortions of the magnetic field can produce the observed pillar-like structures in star forming regions (e.g. Eagle Nebula). Numerical MHD simulations with ...

High tech in the Öresund region

DEFF Research Database (Denmark)

Hansen, Povl Adler; Serin, Göran Folke

This book discusses the development conditions in the high tech sector for both high tech manufacturing and services. A central issue in the book is the differences in externalities which exist between various industries in the high tech sector. In this connection the confusion of externalities...... related to different parts of the high tech sector will be addressed. The location of the high tech sector in the Öresund region will be analysed and the region will also be related to other high tech regions in Europe....

Radiation situation on the territories of the Leningrad Region affected by the Chernobyl accident

Directory of Open Access Journals (Sweden)

G. Ya. Bruk

2017-01-01

Full Text Available The accident at the Chernobyl nuclear power plant was the largest nuclear accident in the world. It led to radioactive contamination of 14 regions of the Russian Federation. In 1991, 4540 settlements were attributable to areas with levels of soil contamination by 137Cs of more than 1.0 Ci/km2. As of 2016, 3855 settlements with the population of more than 1,5 million people are carried to a zone of radioactive contamination according to the Government Directive No 1074 dated October 8, 2015 «On Approval of the List of settlements located within the boundaries of the zones of radioactive contamination from the Chernobyl disaster». In accordance with this Directive, in the Leningrad region 29 settlements were classified as zones of radioactive contamination. This article describes the dynamics of changes in the radiation situation and its current state in the territories of the Leningrad Region affected by the Chernobyl accident. The paper presents the dynamics of 137Cs and 90Sr contents in food products of local origin, the results of calculations of the current average annual effective doses used for the purposes of settlements’ zoning, and the average annual effective radiation doses actually received by the population, dating back to 1986. According to the results of laboratory studies, since 1987, there have been no exceedances of the permissible levels for 137Cs s in agricultural products and food raw materials of local origin. However in the wild products (mushrooms excesses of the permissible levels for 137Cs have been periodically detected. The cases of exceeding the permissible levels for the content of strontium-90 in food, drinking water and water from open water bodies were not recorded for the entire observation period; the determined activity was at the level of tens and hundreds of times less than the permissible levels. In 2016, conservatively estimated average annual effective doses of exposure used for the purposes of

Chemical protection from high LET radiation

International Nuclear Information System (INIS)

Ando, Koichi; Koike, Sachiko; Matsushita, Satoru; Kanai, Tatsuaki; Ohara, Hiroshi

1992-01-01

Radioprotection by WR151327 from high LET fast neutrons was investigated and compared with that from low LET radiation. Radiation damage in bone marrow, intestine, skin and leg length were all protected by a pretreatment with 400 mg/kg WR151327. Most prominent protection was observed for bone marrow, which gave a Dose Modifying Factor (DMF) of 2.2 against γ rays. Identical protection was observed between early and late radiation damage. WR151327 protected fast neutrons less efficiently than γ rays; 40% for bone marrow and 80% for skin leg. Pathological findings indicated that hyperplastic change in both dermis and epidermis associated with late skin shrinkage. Laser doppler flow-metry showed a good relationship between reduction of blood flow and late skin shrinkage. Irradiation of skin by heavy particle Carbon-12 indicated that skin shrinkage was modified by unirradiated surrounding normal tissues, which proposed a significant role of 'Volume Effect' in radiation damage. Tumor tissues were less protected by WR151327 than normal tissues. Dependence of radioprotection by WR151327 on tissue oxygen concentration is a probable reason to explain the difference between normal and tumor tissues. (author)

Radiation transport in high-level waste form

International Nuclear Information System (INIS)

Arakali, V.S.; Barnes, S.M.

1992-01-01

The waste form selected for vitrifying high-level nuclear waste stored in underground tanks at West Valley, NY is borosilicate glass. The maximum radiation level at the surface of a canister filled with the high-level waste form is prescribed by repository design criteria for handling and disposition of the vitrified waste. This paper presents an evaluation of the radiation transport characteristics for the vitreous waste form expected to be produced at West Valley and the resulting neutron and gamma dose rates. The maximum gamma and neutron dose rates are estimated to be less than 7500 R/h and 10 mRem/h respectively at the surface of a West Valley canister filled with borosilicate waste glass

High and Low LET Radiation Differentially Induce Normal Tissue Damage Signals

International Nuclear Information System (INIS)

Niemantsverdriet, Maarten; Goethem, Marc-Jan van; Bron, Reinier; Hogewerf, Wytse; Brandenburg, Sytze; Langendijk, Johannes A.; Luijk, Peter van; Coppes, Robert P.

2012-01-01

Purpose: Radiotherapy using high linear energy transfer (LET) radiation is aimed at efficiently killing tumor cells while minimizing dose (biological effective) to normal tissues to prevent toxicity. It is well established that high LET radiation results in lower cell survival per absorbed dose than low LET radiation. However, whether various mechanisms involved in the development of normal tissue damage may be regulated differentially is not known. Therefore the aim of this study was to investigate whether two actions related to normal tissue toxicity, p53-induced apoptosis and expression of the profibrotic gene PAI-1 (plasminogen activator inhibitor 1), are differentially induced by high and low LET radiation. Methods and Materials: Cells were irradiated with high LET carbon ions or low LET photons. Cell survival assays were performed, profibrotic PAI-1 expression was monitored by quantitative polymerase chain reaction, and apoptosis was assayed by annexin V staining. Activation of p53 by phosphorylation at serine 315 and serine 37 was monitored by Western blotting. Transfections of plasmids expressing p53 mutated at serines 315 and 37 were used to test the requirement of these residues for apoptosis and expression of PAI-1. Results: As expected, cell survival was lower and induction of apoptosis was higher in high -LET irradiated cells. Interestingly, induction of the profibrotic PAI-1 gene was similar with high and low LET radiation. In agreement with this finding, phosphorylation of p53 at serine 315 involved in PAI-1 expression was similar with high and low LET radiation, whereas phosphorylation of p53 at serine 37, involved in apoptosis induction, was much higher after high LET irradiation. Conclusions: Our results indicate that diverse mechanisms involved in the development of normal tissue damage may be differentially affected by high and low LET radiation. This may have consequences for the development and manifestation of normal tissue damage.

A Review: Some biological effects of high LET radiations

Science.gov (United States)

Wiley, A., Jr.

1972-01-01

There are qualitative and quantitative differences in the biological damage observed after exposure to high LET radiation as compared to that caused by low LET radiations. This review is concerned with these differences, which are ultimately reflected at the biochemical, cellular and even whole animal levels. In general, high LET radiations seem to produce biochemical damage which is more severe and possibly less repairable. Experimental data for those effects are presented in terms of biochemical RBE's with consideration of both early and late manifestations. An LET independent process by which significant biochemical damage may result from protons, neutrons and negative pion mesons is discussed.

Custom high-reliability radiation-hard CMOS-LSI circuit design

International Nuclear Information System (INIS)

Barnard, W.J.

1981-01-01

Sandia has developed a custom CMOS-LSI design capability to provide high reliability radiation-hardened circuits. This capability relies on (1) proven design practices to enhance reliability, (2) use of well characterized cells and logic modules, (3) computer-aided design tools to reduce design time and errors and to standardize design definition, and (4) close working relationships with the system designer and technology fabrication personnel. Trade-offs are made during the design between circuit complexity/performance and technology/producibility for high reliability and radiation-hardened designs to result. Sandia has developed and is maintaining a radiation-hardened bulk CMOS technology fabrication line for production of prototype and small production volume parts

The carcinogenic risks of low-LET and high-LET ionizing radiations

International Nuclear Information System (INIS)

Fabrikant, J.I.

1991-08-01

This report presents a discussion on risk from ionizing radiations to human populations. Important new information on human beings has come mainly from further follow-up of existing epidemiological studies, notably the Japanese atomic bomb survivors and the ankylosing spondylitis patients; from new epidemiological surveys, such as the patients treated for cancer of the uterine cervix; and from combined surveys, including workers exposed in underground mines. Since the numerous and complex differences among the different study populations introduce factors that influence the risk estimates derived in ways that are not completely understood, it is not clear how to combine the different risk estimates obtained. These factors involve complex biological and physical variables distributed over time. Because such carcinogenic effects occur too infrequently to be demonstrated at low doses, the risks of low-dose radiation can be estimated only by interpolation from observations at high doses on the basis of theoretical concepts, mathematical models and available empirical evidence, primarily the epidemiological surveys of large populations exposed to ionizing radiation. In spite of a considerable amount of research, only recently has there has been efforts to apply the extensive laboratory data in animals to define the dose-incidence relationship in the low dose region. There simply are insufficient data in the epidemiological studies of large human populations to estimate risk coefficients directly from exposure to low doses. The risk estimates for the carcinogenic effects of radiation have been, in the past, somewhat low and reassessment of the numerical values is now necessary

Effects of high vs low-level radiation exposure

International Nuclear Information System (INIS)

Bond, V.P.

1983-01-01

In order to appreciate adequately the various possible effects of radiation, particularly from high-level vs low-level radiation exposure (HLRE, vs LLRE), it is necessary to understand the substantial differences between (a) exposure as used in exposure-incidence curves, which are always initially linear and without threshold, and (b) dose as used in dose-response curves, which always have a threshold, above which the function is curvilinear with increasing slope. The differences are discussed first in terms of generally familiar nonradiation situations involving dose vs exposure, and then specifically in terms of exposure to radiation, vs a dose of radiation. Examples are given of relevant biomedical findings illustrating that, while dose can be used with HLRE, it is inappropriate and misleading the LLRE where exposure is the conceptually correct measure of the amount of radiation involved

A First Baseline for the Magnets in the High Luminosity LHC Insertion Regions

CERN Document Server

Todesco, E; Ambrosio, G; Arduini, G; Cerutti, F; De Maria, R; Esposito, L; Fartoukh, S; Ferracin, P; Felice, H; Gupta, R; Kersevan, R; Mokhov, N; Nakamoto, T; Rakno, I; Rifflet, J M; Rossi, L; Sabbi, G L; Segreti, M; Toral, F; Xu, Q; Wanderer, P; van Weelderen, R

2014-01-01

The High Luminosity LHC (HL-LHC) project aims at accumulating 3000 fb-1 in the years 2023-2035, i.e. ten times more w.r.t. the nominal LHC performance expected for 2010- 2021. One key element to reach this challenging performance is a new insertion region to reduce the beam size in the interaction point by approximately a factor two. This requires larger aperture magnets in the region spanning from the interaction point to the matching section quadrupoles. This aperture has been fixed to 150 mm for the inner triplet quadrupoles in 2012. In this paper we give a first baseline of the interaction region. We discuss the main motivations that lead us to choose the technology, the combination of fields/gradients and lengths, the apertures, the quantity of superconductor, and the operational margin. Key elements are also the constraints given by the energy deposition in terms of heat load and radiation damage; we present the main features related to shielding and heat removal.

Radiation budget studies using collocated observations from advanced Very High Resolution Radiometer, High-Resolution Infrared Sounder/2, and Earth Radiation Budget Experiment instruments

Science.gov (United States)

Ackerman, Steven A.; Frey, Richard A.; Smith, William L.

1992-01-01

Collocated observations from the Advanced Very High Resolution Radiometer (AVHRR), High-Resolution Infrared Sounder/2 (HIRS/2), and Earth Radiation Budget Experiment (ERBE) instruments onboard the NOAA 9 satellite are combined to describe the broadband and spectral radiative properties of the earth-atmosphere system. Broadband radiative properties are determined from the ERBE observations, while spectral properties are determined from the HIRS/2 and AVHRR observations. The presence of clouds, their areal coverage, and cloud top pressure are determined from a combination of the HIRS/2 and the AVHRR observations. The CO2 slicing method is applied to the HIRS/2 to determine the presence of upper level clouds and their effective emissivity. The AVHRR data collocated within the HIRS/2 field of view are utilized to determine the uniformity of the scene and retrieve sea surface temperature. Changes in the top of the atmosphere longwave and shortwave radiative energy budgets, and the spectral distribution of longwave radiation are presented as a function of cloud amount and cloud top pressure. The radiative characteristics of clear sky conditions over oceans are presented as a function of sea surface temperature and atmospheric water vapor structure.

Epidemiological and radio-biological studies in high background radiation areas of Kerala coast: implications in radiation protection science and human health

International Nuclear Information System (INIS)

Das, Birajalaxmi

2018-01-01

Till date, Linear No Threshold hypothesis (LNT) is well accepted in radiation protection science in spite of its limitations. However, dose response studies using multiple biological end points from high-background radiation areas have challenged the linearity. Radio-biological and epidemiological studies from high level natural radiation areas of Kerala coast showed non-linearity as well as efficient repair of DNA damage in HLNRA indicating that dose limits for public exposure needs to be revisited which may have implications in radiation protection science, human health and low dose radiation biology. However, further studies using high throughput approach is required to identify chronic radiation signatures in human population exposed to elevated level of natural background radiation

U, Th and K distributions inferred from regional geology and the terrestrial radiation profiles in India

International Nuclear Information System (INIS)

Sankaran, A.V.; Jayaswal, B.; Nambi, K.S.V.; Sunta, C.M.

1986-01-01

The natural background radiation or natural radioactivity in environment in any region is mainly due to gamma radiation emanating from uranium, thorium and potassium contents of the ground matter of that region. Instead of carrying out accurate but tedious radiometric surveys at site, a fair estimate of the radiation value of any place can be calculated by knowing different types of rocks exposed at that place and the geochemical distribution of radioelements in those exposed rocks. The geochemical distribution in the exposed rocks can be computed by using worldwide average values of U, Th and K for various kinds of crystal rocks. These average values are obtained from the published geochemical data for different rock types from all over the world. Using this method, the geochemical distributions of U, Th and K are inferred for different states of India and the terrestrial radiation profiles in India are prepared. For this work, the geologic information data contained in the maps and publications of the Geological Survey of India were used. Annual radiation levels are expressed in microgray per year (μGy/y) using conversion factors recommended by UNSCEAR (1982). These represent the absorbed dose levels in air at 1 meter above the earth's surface and take into account the skyshine effect from the earth as an infinite radioactive source. Contributions from cosmic rays are not included in these estimates. Multicolour and monotone (black) maps depicting the fluctuating profile of radiation across the individual States of India and the country as a whole ar e given. Also the details of the radiation contribution of different stratigraphic horizon of each State in the country have been tabulated. It is observed that 1 per cent of the sub-continent shows radiation levels greater than 2000 μGy/y. (M.G.B.). 91 refs., 25 tabs., 35 fi gs

Natural radionuclides in rocks and soils of the high-mountain regions of the Great Caucasus

Science.gov (United States)

Asvarova, T. A.; Abdulaeva, A. S.; Magomedov, M. A.

2012-06-01

The results of the radioecological survey in the high-mountain regions of the Great Caucasus at the heights from 2200 to 3800 m a.s.l. are considered. This survey encompassed the territories of Dagestan, Azerbaijan, Georgia, Chechnya, Northern Ossetia-Alania, Kabardino-Balkaria, Karachay-Cherkessia, and the Stavropol and Krasnodar regions. The natural γ background radiation in the studied regions is subjected to considerable fluctuations and varies from 6 to 40 μR/h. The major regularities of the migration of natural radionuclides 238U, 232Th, 226Ra, and 40K in soils in dependence on the particular environmental conditions (the initial concentration of the radionuclides in the parent material; the intensity of pedogenesis; the intensity of the vertical and horizontal migration; and the geographic, climatic, and landscape-geochemical factors) are discussed.

Synchroton Radiation Sources

International Nuclear Information System (INIS)

Hulbert, S.L.; Williams, G.P.

1998-01-01

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

The Biostack experiment as an approach to high LET radiation research

International Nuclear Information System (INIS)

Hildebrand, D.; Buecker, H.; Facius, R.; Schaefer, M.; Toth, B.; Ruether, W.; Pfohl, R.; Kaiser, R.

1976-01-01

The investigation of biological effects of the penetrating cosmic radiation enforced new experimental techniques, not only to be used in space experiments, but according to theoretical considerations in accelerator experiments as well. Localization and individual evaluation are the main tools for the reduction of the sample space, which allows together with the multiple factorial analysis investigations in a ''dose'' region that is off limits for classical radiobiology. The results of the Biostack experiments proved that there is a serious radiation hazard during longer space flights, which we should be aware of under the aspects of radiation protection and consideration in biological experiments (investigating weightlessness as example)

Regional development via high-speed rail : A study of the Stockholm-Mälaren region and possibilities for Melbourne-regional Victoria

OpenAIRE

Bayley, Michael

2012-01-01

The purpose of this thesis is to examine, based on a study of the regional high-speed corridors in the Stockholm-Mälaren Region, the possibilities for regional high-speed rail in Melbourne-regional Victoria (Australia) to improve accessibility, and achieve regional development and balanced growth between the capital and its surrounding regions. It deals with the concept of 'regional' high-speed rail, a variant of classic high-speed rail that serves centres along regional corridors stemming fr...

Radiation degradation of methyl methacrylate grafted natural rubber

International Nuclear Information System (INIS)

Perera, M.C.S.

1998-01-01

M G rubber is a mixture consisting of the graft copolymer and two home polymers. Natural rubber is known to undergo crosslinking during exposure to high energy radiation where as poly methyl methacrylate is a polymer where high energy radiation causes chain scission. It is interesting to determine how this partially miscible blend of scission and crosslinking polymers will behave under high energy radiation. Dynamic Mechanical Analysis (DMA) was used to study the variations in the glass transition regions during high energy treatment of the polymers. Another techniques that is available to obtain motional information and miscibility of blends is Nuclear Magnetic Resonance Spectroscopy (NMR).The present study is aimed at understanding the changes in the molecular structure of rubber when exposed to high energy radiation. The changes in the dynamic mechanical properties in the glass transition region and solid state NMR were made used of for this investigation. The data obtained from the DMA results were analysed to calculate the radiation chemical yields. The local dynamics were investigated with measurement of carbon relaxation times and molecular structure was studied with focus on the level of intermolecular mixing by proton relaxation times

HEPD on NEXTSat-1: A High Energy Particle Detector for Measurements of Precipitating Radiation Belt Electrons

Science.gov (United States)

Sohn, Jongdae; Lee, Jaejin; Min, Kyoungwook; Lee, Junchan; Lee, Seunguk; Lee, Daeyoung; Jo, Gyeongbok; Yi, Yu; Na, Gowoon; Kang, Kyung-In; Shin, Goo-Hwan

2018-05-01

Radiation belt particles of the inner magnetosphere precipitate into the atmosphere in the subauroral regions when they are pitch-angle scattered into the loss cone by wave-particle interactions. Such particle precipitations are known to be especially enhanced during space storms, though they can also occur during quiet times. The observed characteristics of precipitating electrons can be distinctively different, in their time series as well as in their spectra, depending on the waves involved. The present paper describes the High Energy Particle Detector (HEPD) on board the Next Generation Small Satellite-1 (NEXTSat-1), which will measure these radiation belt electrons from a low-Earth polar orbit satellite to study the mechanisms related to electron precipitation in the sub-auroral regions. The HEPD is based on silicon barrier detectors and consists of three telescopes that are mounted on the satellite to have angles of 0°. 45°, and 90°, respectively with the local geomagnetic field during observations. With a high time resolution of 32 Hz and a high spectral resolution of 11 channels over the energy range from 350 keV to 2 MeV, together with the pitch angle information provided by the three telescopes, HEPD is capable of identifying physical processes, such as microbursts and dust-side relativistic electron precipitation (DREP) events associated with electron precipitations. NextSat-1 is scheduled for launch in early 2018.

Radiation cured coatings for high performance products

International Nuclear Information System (INIS)

Parkins, J.C.; Teesdale, D.H.

1984-01-01

Development over the past ten years of radiation curable coating and lacquer systems and the means of curing them has led to new products in the packaging, flooring, furniture and other industries. Solventless lacquer systems formulated with acrylates and other resins enable high levels of durability, scuff resistance and gloss to be achieved. Ultra violet and electron beam radiation curing are used, the choice depending on the nature of the coating, the product and the scale of the operation. (author)

Assessment of radiation injuries: role of nuclear magnetic resonance

International Nuclear Information System (INIS)

Khushu, Subhash; Rana, Poonam

2014-01-01

In the event of an intentional or accidental release of ionizing radiation, timely assessment of the radiation exposure is critical for the triage and to facilitate timely and optimal medical care to the effected population. In addition to mild to severe injuries to tissues and organs, radiation injury can also cause cognitive decline, depressive behavior and affective state disturbances following exposure to both high and low doses of radiation. These may be even seen without evident tissue injury within hours to days or months to years after exposure to low doses of radiation. In this study, we exploited the multi-parametric contrast of NMR/MRI and its potential to assess radiation dose absorbed and radiation sickness thereof. High resolution NMR spectroscopy experiments were conducted on urine and serum samples collected from mice irradiated (whole body and focal irradiation) with 3, 5 and 8 Gray of γ-radiation at different time points post irradiation. Irradiated mice serum and urine showed distinct metabolic phenotypes and revealed dose and time dependent clustering of irradiated groups depicting different phases of radiation sickness. Increased concentration of urine metabolites related to gut microflora and energy metabolism were observed during different phases of radiation sickness. On the other hand serum spectra reflected changes associated with lipid, energy and membrane metabolism during radiation sickness. In vivo NMR spectroscopy and Diffusion Tensor Imaging (DTI) was also performed in different regions of brain post irradiation in animal model, which showed radiation induced metabolite changes in hippocampus region. Fractional anisotropy (FA) and mean diffusivity (MD) also demonstrated dose related changes in various brain regions which corroborated well with the behavioral parameters. The results of the present work lay a scientific foundation for development of high throughput radiation bio-dosimetry. This could further be useful in development

RCA's regional industrial project

International Nuclear Information System (INIS)

Ali, A.T.

1988-01-01

The Regional Cooperation Agreement (RCA) for Research Development and Training Related to Nuclear Science and Technology, formulated under the auspices of the International Atomic Energy Agency (IAEA), came into force in June 1972. The overall objective of RCA is to promote technical cooperation among the developing and developed countries in the Asia Pacific region in the peaceful uses of nuclear energy and related technology. Currently, the biggest project under RCA is the Regional Project on the Industrial Applications of Isotopes and Radiation Technology for Asia and the Pacific. The project was established in 1982 for a period of five years and was completed in December 1986. The first phase of the project has generated a high degree of awareness on the industrial potential of isotopes and radiation technology throughout the region; produced a cadre of trained manpower in all areas covered by the project; identified the expertise available in the region; and developed in the region, a unique network of people and institutions involved with the utilization of isotope and radiation technology. A Phase II of the project, which cover all but one of the sub-projects under Phase I, was approved in early 1987 for another five years until 1991. (Nogami, K.)

THE EVALUATION OF VORONEZH REGION RADIATION CONTAMINATION IMPACT OVER THIRTY YEARS’ PERIOD FOLLOWING THE CHERNOBYL ACCIDENT

Directory of Open Access Journals (Sweden)

Yu. I. Stepkin

2016-01-01

Full Text Available The study aimed at radiation contamination impact assessment due to the 1986 Chernobyl accident in Voronezh Region territory more than 600 kilometers away from the ground zero. The major Chernobyl accident impact assessment indicators were the characteristics of 137Cs and 90Sr radionuclides’ soil surface contamination (Ci/km2 as well as the average annual effective dose of critical population group ( mSv/year over 1986–2014. The Population oncological morbidity indicators were analyzed (all malignant neoplasms, including those in thyroid gland, lymphatic and hematopoietic tissue in the territories contrastingly differing on the levels of radiation factor impact. The study covered the period of 2010–2014.It was established that for Voronezh Region territories referred to as the post- Chernobyl radioactively contaminated zone over 29 years period the maximum soil surface contamination by 137Cs and 90Sr radionuclides reduced by 1.90 and 1.91 times (from 3,15 Ci/km2 to 1,66 Ci/km2 and from 0,063 Ci/km2 to 0,0033 Ci/km2, respectively.Currently the relationship was not found between the radioactive contamination density in Voronezh Region and the levels of malignant neoplasms for the local residents.The present situation related to radiation factor impact on Voronezh Region territories remains stable and safe. Mindful of the indicators results the assessment of ionizing sources impact did not identify any exceeding the normative values.

Dispersive effects in radiation transport and radiation hydrodynamics in matter at high density

International Nuclear Information System (INIS)

Crowley, B.J.B.

1983-01-01

In a recent research program (reported in AWRE 0 20/82) I have investigated the generalisation of the equations of radiation hydrodynamics when electromagnetic radiation is assumed to obey a linear-response dispersion relation of the form nω=kc where the refractive index n depends on the frequency ω and/or wave number k. From the application of the Boltzmann-Liouville transport theory to photons in the short-wavelength (geometrical optics) limit, I derive the energy and momentum equations which, when combined with a classical (Euler-Lagrange-Navier-Stokes) treatment of a fluid material medium in LTE, yield a complete dynamical theory of linear interactions (+ stimulated processes) between incoherent (thermal) radiation and dense, locally isotropic matter. The theory includes an account of pondero-motive forces and electro (magneto) striction. Moreover, it is apparently capable of being generalised to non-linear interactions in which the refractive index depends on the local specific intensity of the radiation field, and, to some extent, to the treatment of high-frequency coherent radiation. The generalisation of various approximated forms of radiation-transport theory (esp. diffusion) has been considered in detail. Some problems remain however. One such is the treatment of anomalous dispersion. Current research work is concentrating on the interesting atomic physics aspects of electromagnetic (esp. radiative) properties of a dispersive material medium

Environmental radiation measurements and remedial actions (Hantepe/Ezine/Canakkale)

International Nuclear Information System (INIS)

2009-01-01

There are some regions in the world that are known as high background radiation areas. Intensive scientific investigations in the field of radiation dose and health effects, risk estimates, radiation protection, environmental transportation routes and ecological effects related with natural radiation have been carried out in these regions. Also natural radiation dosimetry, in vitro and in vivo biological studies which take into account the measurements in the field of low level radiation, radon, thoron and cosmic rays have been carried out, again in these regions. The well-known high natural background radiation areas in the world are Guarapari in Brazil, Ramsar in Iran, Kerala in India and Yangjiang in China. In addition to above mentioned areas, other relatively lower high background radiation areas are exist. Since 1960s, radiological, geological, epidemiological and ecological studies have been carried out in order to determine the risks and possible health effects of long-term low level natural radiation exposure. In the framework of surveying the background radiation of Turkey, the background radiation measurements were carried out in 56 different points around the area of Canakkale city. The radiation levels at Hantepe beach of Geyikli which is located in Ezine town of Canakkale was found higher than the mean background radiation level of the region. The radiation dose rates were measured in between 0.20 and 10.88 Gy h-1 in contact and 0.27 and 3.11 Gy h-1 above 1 meter of the ground level where the thorium-containing sand is dense. After the rehabilitation studies, the radiation dose rate were measured in between 0.15 and 8.09 Gy h-1 in contact and 0.17 and 2.88 Gy h-1 above 1 meter of the ground level. It was observed that the radiation dose rates were decreased seriously after the rehabilitation studies when the arithmetic mean value of the dose rates was taken into account. The effective dose calculations were performed by taking into account the

Low index contrast heterostructure photonic crystal cavities with high quality factors and vertical radiation coupling

Science.gov (United States)

Ge, Xiaochen; Minkov, Momchil; Fan, Shanhui; Li, Xiuling; Zhou, Weidong

2018-04-01

We report here design and experimental demonstration of heterostructure photonic crystal cavities resonating near the Γ point with simultaneous strong lateral confinement and highly directional vertical radiation patterns. The lateral confinement is provided by a mode gap originating from a gradual modulation of the hole radii. High quality factor resonance is realized with a low index contrast between silicon nitride and quartz. The near surface-normal directional emission is preserved when the size of the core region is scaled down. The influence of the cavity size parameters on the resonant modes is also investigated theoretically and experimentally.

THE ROLE OF RADIATION PRESSURE IN THE NARROW LINE REGIONS OF SEYFERT HOST GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Davies, Rebecca L.; Dopita, Michael A.; Kewley, Lisa; Groves, Brent; Sutherland, Ralph; Hampton, Elise J.; Banfield, Julie [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Shastri, Prajval; Kharb, Preeti; Bhatt, Harish [Indian Institute of Astrophysics, Sarjapur Road, Bengaluru 560034 (India); Scharwächter, Julia [LERMA, Observatoire de Paris, PSL, CNRS, Sorbonne Universités, UPMC, F-75014 Paris (France); Jin, Chichuan [Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Zaw, Ingyin [New York University (Abu Dhabi), 70 Washington Square S, New York, NY 10012 (United States); James, Bethan [Institute of Astronomy, Cambridge University, Madingley Road, Cambridge CB3 0HA (United Kingdom); Juneau, Stéphanie [CEA-Saclay, DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); Srivastava, Shweta, E-mail: Rebecca.Davies@anu.edu.au [Astronomy and Astrophysics Division, Physical Research Laboratory, Ahmedabad 380009 (India)

2016-06-10

We investigate the relative significance of radiation pressure and gas pressure in the extended narrow line regions (ENLRs) of four Seyfert galaxies from the integral field Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). We demonstrate that there exist two distinct types of starburst-active galactic nucleus (AGN) mixing curves on standard emission line diagnostic diagrams, which reflect the balance between gas pressure and radiation pressure in the ENLR. In two of the galaxies the ENLR is radiation pressure dominated throughout and the ionization parameter remains constant (log U ∼ 0). In the other two galaxies radiation pressure is initially important, but gas pressure becomes dominant as the ionization parameter in the ENLR decreases from log U ∼ 0 to −3.2 ≲ log U ≲ −3.4. Where radiation pressure is dominant, the AGN regulates the density of the interstellar medium on kiloparsec scales and may therefore have a direct impact on star formation activity and/or the incidence of outflows in the host galaxy to scales far beyond the zone of influence of the black hole. We find that both radiation pressure dominated and gas pressure dominated ENLRs are dynamically active with evidence for outflows, indicating that radiation pressure may be an important source of AGN feedback even when it is not dominant over the entire ENLR.

Radiation safety program in a high dose rate brachytherapy facility

International Nuclear Information System (INIS)

Rodriguez, L.V.; Hermoso, T.M.; Solis, R.C.

2001-01-01

The use of remote afterloading equipment has been developed to improve radiation safety in the delivery of treatment in brachytherapy. Several accidents, however, have been reported involving high dose-rate brachytherapy system. These events, together with the desire to address the concerns of radiation workers, and the anticipated adoption of the International Basic Safety Standards for Protection Against Ionizing Radiation (IAEA, 1996), led to the development of the radiation safety program at the Department of Radiotherapy, Jose R. Reyes Memorial Medical Center and at the Division of Radiation Oncology, St. Luke's Medical Center. The radiation safety program covers five major aspects: quality control/quality assurance, radiation monitoring, preventive maintenance, administrative measures and quality audit. Measures for evaluation of effectiveness of the program include decreased unnecessary exposures of patients and staff, improved accuracy in treatment delivery and increased department efficiency due to the development of staff vigilance and decreased anxiety. The success in the implementation required the participation and cooperation of all the personnel involved in the procedures and strong management support. This paper will discuss the radiation safety program for a high dose rate brachytherapy facility developed at these two institutes which may serve as a guideline for other hospitals intending to install a similar facility. (author)

Infrared Radiation and Blackbody Radiation

OpenAIRE

2005-01-01

tut present graph Tutorial Presentation Graph Interactive Media Element This interactive tutorial covers the following: How infrared radiation was discovered., The regions of infrared radiation and their relations to temperature., The nature of blackbody radiation and Planck's radiation law., The relationship between temperature and the power emitted by radiation.The interactions in this tutorial include clicking to reveal new information, and questions that help students...

New sources of high-power coherent radiation

International Nuclear Information System (INIS)

Sprehngl, F.

1985-01-01

New sources of high-power coherent radiation in the wavelength range from millimeter to ultraviolet are reviewed. Physical mechanisms underlying concepts of free electrons laser, cyclotron resonance laser and other new radiation sources are described. Free electron lasers and cyclotron resonance lasers are shown to suggest excellent possibilities for solving problems of spectroscopy, plasma heating radar and accelerator technology. Results of experiments with free electron laser in the Compton mode using linear accelerators microtrons and storage rings are given. Trends in further investigations are shown

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

Science.gov (United States)

Higuchi, Yoshinori; Nelson, Gregory A.; Vazquez, Marcelo; Laskowitz, Daniel T.; Slater, James M.; Pearlstein, Robert D.

2002-01-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. METHODS: Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. ROTAROD TEST: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. OPEN FIELD TEST: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. MORRIS WATER MAZE: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. CONCLUSIONS: These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the CNS. ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process.

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

International Nuclear Information System (INIS)

Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D.; Laskowitz, D.T.

2002-01-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. Rotarod test: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. Open field test: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. Morris water maze: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the central nervous system (CNS). ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process. (author)

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

Energy Technology Data Exchange (ETDEWEB)

Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D. [Loma Linda Univ., CA (United States). Medical Center; Vazquez, M. [Brookhaven National Lab., Upton, NY (United States); Laskowitz, D.T. [Duke Univ., Durham, NC (United States). Medical Center

2002-12-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. Rotarod test: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. Open field test: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. Morris water maze: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the central nervous system (CNS). ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process. (author)

Regional Modeling of Dust Mass Balance and Radiative Forcing over East Asia using WRF-Chem

Energy Technology Data Exchange (ETDEWEB)

Chen, Siyu; Zhao, Chun; Qian, Yun; Leung, Lai-Yung R.; Huang, J.; Huang, Zhongwei; Bi, Jianrong; Zhang, Wu; Shi, Jinsen; Yang, Lei; Li, Deshuai; Li, Jinxin

2014-12-01

The Weather Research and Forecasting model with Chemistry (WRF-Chem) is used to investigate the seasonal and annual variations of mineral dust over East Asia during 2007-2011, with a focus on the dust mass balance and radiative forcing. A variety of measurements from in-stu and satellite observations have been used to evaluate simulation results. Generally, WRF-Chem reproduces not only the column variability but also the vertical profile and size distribution of mineral dust over and near the dust source regions of East Asia. We investigate the dust lifecycle and the factors that control the seasonal and spatial variations of dust mass balance and radiative forcing over the seven sub-regions of East Asia, i.e. source regions, the Tibetan Plateau, Northern China, Southern China, the ocean outflow region, and Korea-Japan regions. Results show that, over the source regions, transport and dry deposition are the two dominant sinks. Transport contributes to ~30% of the dust sink over the source regions. Dust results in a surface cooling of up to -14 and -10 W m-2, atmospheric warming of up to 20 and 15 W m-2, and TOA cooling of -5 and -8 W m-2 over the two major dust source regions of East Asia, respectively. Over the Tibetan Plateau, transport is the dominant source with a peak in summer. Over identified outflow regions, maximum dust mass loading in spring is contributed by the transport. Dry and wet depositions are the comparably dominant sinks, but wet deposition is larger than dry deposition over the Korea-Japan region, particularly in spring (70% versus 30%). The WRF-Chem simulations can generally capture the measured features of dust aerosols and its radaitve properties and dust mass balance over East Asia, which provides confidence for use in further investigation of dust impact on climate over East Asia.

Radiation doses to adult patients in interventional procedure: the first data for the Biobio region

International Nuclear Information System (INIS)

Ubeda, C.A.; Nocetti, D.A.; Robles, I.L.

2013-01-01

The main objective of this study was to estimate the levels of radiation to the patient in interventional cardiology procedures and neurological (diagnostic and therapeutic) in the main public hospital in Chile, in the region of Biobio

Induction of wound-periderm-like tissue in Kalanchoe pinnata (Lam.) Pers. (Crassulaceae) leaves as a defence response to high UV-B radiation levels.

Science.gov (United States)

Nascimento, Luana Beatriz dos Santos; Moreira, Nattacha dos Santos; Leal-Costa, Marcos Vinícius; Costa, Sônia Soares; Tavares, Eliana Schwartz

2015-10-01

UV-B radiation can be stressful for plants and cause morphological and biochemical changes. Kalanchoe pinnata is a CAM leaf-succulent species distributed in hot and dry regions, and is rich in flavonoids, which are considered to be protective against UV-B radiation. This study aims to verify if K. pinnata has morphological or anatomical responses as a strategy in response to high UV-B levels. Kalanchoe pinnata plants of the same age were grown under white light (control) or white light plus supplemental UV-B radiation (5 h d(-1)). The plants were treated with the same photoperiod, photosynthetically active radiation, temperature and daily watering system. Fragments of the middle third of the leaf blade and petiole were dehydrated and then embedded in historesin and sectioned in a rotary microtome. Sections were stained with toluidine blue O and mounted in Entellan®. Microchemical analyses by optical microscopy were performed on fresh material with Sudan III, Sudan IV and phloroglucinol, and analysed using fluorescence microscopy. Supplemental UV-B radiation caused leaf curling and the formation of brown areas on the leaves. These brown areas developed into a protective tissue on the adaxial side of the leaf, but only in directly exposed regions. Anatomically, this protective tissue was similar to a wound-periderm, with outer layer cell walls impregnated with suberin and lignin. This is the first report of wound-periderm formation in leaves in response to UV-B radiation. This protective tissue could be important for the survival of the species in desert regions under high UV-B stress conditions. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radiation damage in molybdenum and tungsten in high neutron fluxes

International Nuclear Information System (INIS)

Veljkovic, S.; Milasin, N.

1964-01-01

The effects of radiation on molybdenum and tungsten in high neutron fluxes are presented. The changes induced, particularly defects with a high migration activation energy, are analyzed. The correlation of these changes with the basic concepts of radiation damage in solids is considered. An attempt is made to relate the defects studied with the changes in macroscopic properties (author)

Radiation damage in molybdenum and tungsten in high neutron fluxes

Energy Technology Data Exchange (ETDEWEB)

Veljkovic, S; Milasin, N [Institute of Nuclear Sciences Boris Kidric, Department of Reactor Materials, Vinca, Beograd (Serbia and Montenegro)

1964-04-15

The effects of radiation on molybdenum and tungsten in high neutron fluxes are presented. The changes induced, particularly defects with a high migration activation energy, are analyzed. The correlation of these changes with the basic concepts of radiation damage in solids is considered. An attempt is made to relate the defects studied with the changes in macroscopic properties (author)

Radiation doses at high altitudes and during space flights

International Nuclear Information System (INIS)

Spurny, F.

2001-01-01

There are three main sources of radiation exposure during space flights and at high altitudes--galactic cosmic radiation, solar cosmic radiation and radiation of the earth's radiation belt. Their basic characteristics are presented in the first part of this paper.Man's exposure during space flights is discussed in the second part of the paper. Particular attention is devoted to the quantitative and qualitative characteristics of the radiation exposure on near-earth orbits: both theoretical estimation as well as experimental data are presented. Some remarks on radiation protection rules on-board space vehicles are also given.The problems connected with the radiation protection of air crew and passengers of subsonic and supersonic air transport are discussed in the last part of the paper. General characteristics of on-board radiation fields and their variations with flight altitude, geomagnetic parameters of a flight and the solar activity are presented, both based on theoretical estimates and experimental studies. The questions concerning air crew and passenger radiation protection arising after the publication of ICRP 60 recommendation are also discussed. Activities of different institutions relevant to the topic are mentioned; strategies to manage and check this type of radiation exposure are presented and discussed. Examples of results based on the author's personal experience are given, analyzed and discussed. (author)

6. Regional Congress on Radiation Protection and Safety; 3. Iberian and Latin American Congress on Radiological Protection Societies; Regional IRPA Congress. Book of abstracts; 6. Congreso Regional sobre Seguridad Radiologica y Nuclear; 3. Congreso Iberolatinoamericano de Sociedades de Proteccion Radiologica; Congreso Regional IRPA. Libro de resumenes

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-11-15

The 6th Regional Congress on Radiation Protection and Safety was organized by the Peruvian Radiation Protection Society and the Peruvian Institute of Nuclear Energy, held in Lima, Peru, between 9 and 13 of november of 2003. In this event, were presented 227 papers that were articulated in the following sessions: radiation natural exposure, biological effects of ionizing radiation, instruments and dosimetry, radiological emergency and accidents, occupational radiation protection, radiological protection in medical exposure, radiological environmental protection, legal aspects, standards and regulations, training, education and communication, radioactive waste management, radioactive material transport, nuclear safety and biological effects of non-ionizing radiation. (APC)

Clinical outcomes of image guided radiation therapy (IGRT) with gold fiducial vaginal cuff markers for high-risk endometrial cancer

Energy Technology Data Exchange (ETDEWEB)

Monroe, Alan T.; Peddada, Anuj V. [Dept. of Radiation Oncology, Penrose Cancer Center, Colorado Springs (United States); Pikaart, Dirk [Dept. of Gynecologic Oncology, Penrose Cancer Center, Colorado Springs (United States)

2013-06-15

Objective. To report two year clinical outcomes of image guided radiation therapy (IGRT) to the vaginal cuff and pelvic lymph nodes in a series of high-risk endometrial cancer patients. Methods . Twenty-six consecutive high-risk endometrial cancer patients requiring adjuvant radiation to the vaginal cuff and regional lymph nodes were treated with vaginal cuff fiducial-based IGRT. Seventeen (65%) received sequential chemotherapy, most commonly with a sandwich technique. Brachytherapy followed external radiation in 11 patients to a median dose of 18 Gy in 3 fractions. The median external beam dose delivered was 47.5 Gy in 25 fractions. Results. All 656 fractions were successfully imaged and treated. The median overall translational shift required for correction was 9.1 mm (standard deviation, 5.2 mm) relative to clinical set-up with skin tattoos. Shifts of 1 cm, 1.5 cm, and 2 cm or greater were performed in 43%, 14%, and 4% of patients, respectively. Acute grade 2 gastrointestinal (GI) toxicity occurred in eight patients (30%) and grade 3 toxicity occurred in one. At two years, there have been no local or regional failures and actuarial overall survival is 95%. Conclusion. Daily image guidance for high-risk endometrial cancer results in a low incidence of acute GI/genitourinary (GU) toxicity with uncompromised tumor control at two years. Vaginal cuff translations can be substantial and may possibly result in underdosing if not properly considered.

Clinical outcomes of image guided radiation therapy (IGRT) with gold fiducial vaginal cuff markers for high-risk endometrial cancer

International Nuclear Information System (INIS)

Monroe, Alan T.; Peddada, Anuj V.; Pikaart, Dirk

2013-01-01

Objective. To report two year clinical outcomes of image guided radiation therapy (IGRT) to the vaginal cuff and pelvic lymph nodes in a series of high-risk endometrial cancer patients. Methods . Twenty-six consecutive high-risk endometrial cancer patients requiring adjuvant radiation to the vaginal cuff and regional lymph nodes were treated with vaginal cuff fiducial-based IGRT. Seventeen (65%) received sequential chemotherapy, most commonly with a sandwich technique. Brachytherapy followed external radiation in 11 patients to a median dose of 18 Gy in 3 fractions. The median external beam dose delivered was 47.5 Gy in 25 fractions. Results. All 656 fractions were successfully imaged and treated. The median overall translational shift required for correction was 9.1 mm (standard deviation, 5.2 mm) relative to clinical set-up with skin tattoos. Shifts of 1 cm, 1.5 cm, and 2 cm or greater were performed in 43%, 14%, and 4% of patients, respectively. Acute grade 2 gastrointestinal (GI) toxicity occurred in eight patients (30%) and grade 3 toxicity occurred in one. At two years, there have been no local or regional failures and actuarial overall survival is 95%. Conclusion. Daily image guidance for high-risk endometrial cancer results in a low incidence of acute GI/genitourinary (GU) toxicity with uncompromised tumor control at two years. Vaginal cuff translations can be substantial and may possibly result in underdosing if not properly considered

Handbook on synchrotron radiation, v.2

CERN Document Server

1987-01-01

Volume 2 of this series concentrates on the use of synchrotron radiation which covers that region of the electromagnetic spectrum which extends from about 10eV to 3keV in photon energy and is essentially the region where the radiation is strongly absorbed by atmospheric gases. It therefore has to make extensive use of a high vacuum to transport the radiation to the workstation where the presence of hard X-rays can cause extensive damage to both the optics and the targets used in the experimental rigs. The topics chosen for this volume have been limited to the disciplines of physics and chemi

High energy beam impact tests on a LHC tertiary collimator at the CERN high-radiation to materials facility

Directory of Open Access Journals (Sweden)

Marija Cauchi

2014-02-01

Full Text Available The correct functioning of a collimation system is crucial to safely operate highly energetic particle accelerators, such as the Large Hadron Collider (LHC. The requirements to handle high intensity beams can be demanding. In this respect, investigating the consequences of LHC particle beams hitting tertiary collimators (TCTs in the experimental regions is a fundamental issue for machine protection. An experimental test was designed to investigate the robustness and effects of beam accidents on a fully assembled collimator, based on accident scenarios in the LHC. This experiment, carried out at the CERN High-Radiation to Materials (HiRadMat facility, involved 440 GeV proton beam impacts of different intensities on the jaws of a horizontal TCT. This paper presents the experimental setup and the preliminary results obtained, together with some first outcomes from visual inspection and a comparison of such results with numerical simulations.

High energy beam impact tests on a LHC tertiary collimator at the CERN high-radiation to materials facility

Science.gov (United States)

Cauchi, Marija; Aberle, O.; Assmann, R. W.; Bertarelli, A.; Carra, F.; Cornelis, K.; Dallocchio, A.; Deboy, D.; Lari, L.; Redaelli, S.; Rossi, A.; Salvachua, B.; Mollicone, P.; Sammut, N.

2014-02-01

The correct functioning of a collimation system is crucial to safely operate highly energetic particle accelerators, such as the Large Hadron Collider (LHC). The requirements to handle high intensity beams can be demanding. In this respect, investigating the consequences of LHC particle beams hitting tertiary collimators (TCTs) in the experimental regions is a fundamental issue for machine protection. An experimental test was designed to investigate the robustness and effects of beam accidents on a fully assembled collimator, based on accident scenarios in the LHC. This experiment, carried out at the CERN High-Radiation to Materials (HiRadMat) facility, involved 440 GeV proton beam impacts of different intensities on the jaws of a horizontal TCT. This paper presents the experimental setup and the preliminary results obtained, together with some first outcomes from visual inspection and a comparison of such results with numerical simulations.

CMOS pixel sensors on high resistive substrate for high-rate, high-radiation environments

Energy Technology Data Exchange (ETDEWEB)

Hirono, Toko, E-mail: thirono@uni-bonn.de [Physikalisches Institute der Universität Bonn, Bonn (Germany); Barbero, Marlon; Breugnon, Patrick; Godiot, Stephanie [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Gonella, Laura; Hemperek, Tomasz; Hügging, Fabian; Krüger, Hans [Physikalisches Institute der Universität Bonn, Bonn (Germany); Liu, Jian; Pangaud, Patrick [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Peric, Ivan [IPE, Karlsruher Institut für Technologie, Karlsruhe (Germany); Pohl, David-Leon [Physikalisches Institute der Universität Bonn, Bonn (Germany); Rozanov, Alexandre [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Rymaszewski, Piotr [Physikalisches Institute der Universität Bonn, Bonn (Germany); Wang, Anqing [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Wermes, Norbert [Physikalisches Institute der Universität Bonn, Bonn (Germany)

2016-09-21

A depleted CMOS active pixel sensor (DMAPS) has been developed on a substrate with high resistivity in a high voltage process. High radiation tolerance and high time resolution can be expected because of the charge collection by drift. A prototype of DMAPS was fabricated in a 150 nm process by LFoundry. Two variants of the pixel layout were tested, and the measured depletion depths of the variants are 166 μm and 80 μm. We report the results obtained with the prototype fabricated in this technology.

Publishing the pamphlet of radiation education for junior high school students

International Nuclear Information System (INIS)

Kamezawa, Chika; Kamogawa, Masashi; Kanai, Yuko; Nishiura, Shingo; Banda, Kiyomi; Arakawa, Etsuo

2014-01-01

We made supplementary materials of the radiation education as a pamphlet for junior high school students along the government course guidelines for junior high school pressed by Ministry of Education, Culture, Sports, Science and Technology. The pamphlet was published as booklet and calendar. For teachers at junior high schools, a pdf file of the booklet was also appended. The pamphlet focused natural phenomenon and latest researches in the radiation science. Many pictures in the booklet could help students to study the radiation science visually. For 100 days since March 2012 published day, 4119 booklets had been distributed to junior high schools and other schools of applicants, free of charge. (author)

Study on Basic Characteristics for the Development of Radiation Shielding High-Weight Concrete

Energy Technology Data Exchange (ETDEWEB)

Mun, Young Bum; Lee, Jea Hyung; Choi, Hyun Kook [Sungshin Cement CO., Sejong (Korea, Republic of); Oh, Jeong Hwan; Choi, Soo Seok [Jeju National University, Jeju (Korea, Republic of)

2016-05-15

It is planned to build a power plant more than 6 units. Although the demand of a nuclear power plant is going to increase, the attention for radiation shielding is relatively in a low level. Concrete is one of the excellent and widely used shielding materials. Since the radiation shielding of a given material is proportional to density and thickness, a high-weight concrete with high-weight aggregate which is higher than normal concrete is used for radiation shielding. However, there are a few studies and references about radiation shielding concrete. Therefore, it is required to find a high-weight aggregate. The purpose of this paper is the development of a highweight concrete to improve radiation shielding capability. The radiation shielding rate of high-weight concrete is higher than that of reference concrete. It is confirmed that the density of aggregate and the unit weight of concreate is proportional to the radiation shielding rate. In addition, the chemical composition of aggregate has also has an important effect on γ-ray shielding. Therefore, high weight aggregates of higher density are essentially required to improve radiation shielding capability. The compressive strength of a high weight concrete is better than that of reference concrete. Slump and air contents, however, are slightly increased with by-product aggregates.

Determination of the parametric region in which runaway electron energy losses are dominated by bremsstrahlung radiation in tokamaks

International Nuclear Information System (INIS)

Fernandez-Gomez, I.; Martin-Solis, J. R.; Sanchez, R.

2007-01-01

It has been recently argued that, at sufficiently large parallel electric fields, bremsstrahlung radiation can greatly reduce the maximum energy that runaway electrons can gain in tokamaks [M. Bakhtiari et al., Phys. Plasmas 12, 102503 (2005)]. In this contribution, the work of these authors is extended to show that the region where bremsstrahlung radiation dominate runaway energy losses is however more restricted than reported by them. Expressions will be provided for the limits of this region within the parameter space spanned by the background density and parallel electric field, as a function of the rest of the plasma parameters. It will be shown that the background density has to be above a certain critical value and that the parallel electric field must lie within a range of values, below and above which synchrotron radiation dominate the runaway energy losses. Finally, it will be demonstrated that typical disruption parameters lie within this region and, as a result, bremsstrahlung losses still play an important role in controlling the runaway energy

Materials science created by synchrotron radiation

International Nuclear Information System (INIS)

Oshima, Masaharu

2015-01-01

We survey the use of synchrotron radiation for studies on oxides. High luminosity enables the spectroscopy with high energy-resolution in soft X-ray and vacuum ultraviolet region. Element analysis is possible by examining absorption edge in the X-ray absorption spectra. Time-resolved measurements are possible due to the pulsed nature of the radiation. The radiation can bear linear or circular polarization. The feature of molecules adhered on a surface can be clarified by using linearly polarized radiation. The circularly polarized radiation, on the other hand, clarifies the magnetic structure. The structure information so far unknown can be obtained by using space- or time-coherent radiation. We show studies using synchrotron radiation on LSI gate oxide foils, variable resistance RAM, strongly correlated oxide foils, and the oxide as positive electrode of Li ion battery. (J.P.N.)

Malignant tumors arising in the maxillary region after radiation therapy

International Nuclear Information System (INIS)

Shimizu, Sawamichi; Shirahata, Yuichi; Uchida, Yutaka

1984-01-01

Although radiotherapy has proven of great therapeutic value in the treatment of malignant tumors, it should also be borne in mind that radiation has a serious potential risk of giving rise to a secondary malignancy. We recently experienced 2 cases each of carcinoma and sarcoma arising in the irradiated areas long after radiation therapy for malignant tumors. In these 4 cases, 2 males and 2 females, the primary neoplastic diseases were squamous cell carcinoma, epidermoid carcinoma, carcinoma of unknown pathology and malignant lymphoma, and the secondary tumors were epidermoid carcinoma, squamous cell carcinoma, osteosarcoma and chondrosarcoma, respectively. The sites of occurrence of these malignancies were invariably in the maxillary region; the mean latent period was 15 years, aside from an infantile case with a latent period of 5 years. In view of the primary diseases being malignant tumors the following criteria were set up for the diagnosis of radiation-induced malignancies: (1) the site of occurrence is within the confines of a previously irradiated area, (2) the latent period is prolonged and (3) the malignancy occurs as a double tumor. Therapy was primarily by operation. The prognosis was exceedingly ominous, the average survival time being 22 months. This was probably and mainly because of rapidity of tumor growth. Thus, the secondary tumors had already spread back to inward by the time they were first discovered. This should be kept in mind during a long-term follow-up of patients receiving radiotherapy for malignancy. (author)

High-LET radiation carcinogenesis

International Nuclear Information System (INIS)

Fry, R.J.M.; Powers-Risius, P.; Alpen, E.L.; Ainsworth, E.J.

1985-01-01

The dose-response curves for the induction of tumors by high-LET radiation are complex and are insufficiently understood. There is no model or formulation to describe the dose-response relationship over a range 0 to 100 rad. Evidence suggests that at doses below 20 rad the response is linear, at least for life shortening and some tumor systems. Thus, limiting values of RBEs for the induction of cancer in various tissues can be determined, but it will require sufficient data obtained at low single doses or with small fractions. The results obtained from experiments with heavy ions indicate an initial linear response with a plateauing of the curve at a tumor incidence level that is dependent on the type of tissue. The RBE values for the heavy ions using 60 Co gamma rays as the reference radiation increase with the estimated LET from 4 for 4 H to about 27 for 56 Fe, 40 Ar. The dose-responses and RBEs for 56 Fe and 40 Ar are similar to those for fission neutrons. These findings suggest the possibility that the effectiveness for tumor induction reaches a maximum. 26 refs., 4 figs., 2 tabs

Analysis of radiation damage to Si solar cells under high-fluence electron irradiation

International Nuclear Information System (INIS)

Yamaguchi, Masafumi; Taylor, S.J.; Yang, Ming-Ju; Matsuda, Sumio; Kawasaki, Osamu; Hisamatsu, Tadashi.

1996-01-01

Radiation testing of Si n + -p-p + space solar cells has revealed an anomalous increase in short-circuit current I sc , followed by an abrupt decrease and cell failure, induced by high-fluence (>10 16 cm -2 ) electron irradiation. A model which can be used to explain these phenomena by expressing the change in majority-carrier concentration p of the base region as a function of the electron fluence has been proposed in addition to the well-known model in which I sc is decreased due to minority-carrier lifetime reduction with irradiation. The reduction in p due to majority-carrier trapping by radiation-induced defects has two effects; one is broadening of the depletion layer which contributes to the increase in the generated photocurrent and that in the recombination-generation current in the depletion layer, and the second is an increase in the resistivity of the base layer resulting in an abrupt decrease of I sc and failure of the solar cells. (author)

The high pressure xenon lamp as a source of radiation

International Nuclear Information System (INIS)

Heerdt, J.A. ter.

1979-01-01

An account is given of an investigation into the radiation properties of a commercially available high pressure xenon lamp (type XBO 900 W) in the spectral range 0.3 to 3 μm. The purpose of the study was to find out whether such a lamp can serve as a (secondary) standard of radiation in spectroscopic and radiometric measurements. The main advantades of the xenon lamp over other secondary standards such as the tungsten strip lamp and the anode of a carbon arc lamp are the high temperature of its discharge and the resulting strong radiation over a broad spectral range. (Auth.)

High technology for radiation application

International Nuclear Information System (INIS)

Iida, Toshiyuki

2005-03-01

Fundamentals of radiations, radioactivity, and their applications in recent industrial, medical, agricultural and various research fields are reviewed. The book begins with historical description regarding to discovery of radiation at the end of 19th century and the exploration into the inside of an atom utilizing the radiation discovered, discovery of the neutron which finally leaded to nuclear energy liberation. Developments of radiation sources, including nuclear reactors, and charged-particle accelerators follow with simultaneous description on radiation measurement or detection technology. In medical fields, X-ray diagnosis, interventional radiology (IVR), nuclear medicine (PET and others), and radiation therapy are introduced. In pharmaceutical field, synthesis of labeled compounds and tracer techniques are explained. In industrial application, radiation-reinforced wires and heat-resistant cables whose economic effect can be estimated to amount to more than 10 12 yen, radiation mutation, food irradiation, and applied accelerators such as polymer modifications, decomposition of environmentally harmful substances, and ion-implantations important in semiconductor device fabrication. Finally, problems relating to general public such as radiation education and safety concept are also discussed. (S. Ohno)

An analysis of the awareness and performance of radiation workers' radiation/radioactivity protection in medical institutions : Focused on Busan regional medical institutions

Energy Technology Data Exchange (ETDEWEB)

Park, Cheol Koo [Dept. of Radiological Science, Graduate School of Catholic University of Pusan, Busan (Korea, Republic of); Hwang, Chul Hwan [Dept. of Radiation Oncology, Pusan National University Hospital, Busan (Korea, Republic of); Kim, Dong Hyun [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of)

2017-03-15

The purpose of this study was to investigate safety management awareness and behavioral investigation of radiation/radioactivity performance defenses of radiation workers' in medical institutions. Data collection consisted of 267 radiation workers working in medical institutions using structured questionnaires. As a result, it was analyzed that radiation safety management awareness and performance were high in 40s, 50s group and higher education group. The analysis according to the radiation safety management knowledge was analyzed that the 'Know very well' group had higher scores on awareness and performance scores. The analysis according to the degree of safety management effort showed the high awareness scale and the performance scale in the group 'Receiving various education or studying the safety management contents through book'. The correlations between the sub-factors showed the highest positive correlation between perceived practician and personal perspective and perceived by patient and patient's caretaker perspective. Therefore, radiation safety management for workers, patients, and patient's caretaker should be conducted through continuous education of radiation safety management through various routes of radiation workers working at medical institutions.

Photovoltaic Systems with and without Radiation Concentrators for Temperate and Tropical Regions

Directory of Open Access Journals (Sweden)

Vania Reis de Souza Sant’Anna

2015-11-01

Full Text Available The industrial development of solar photovoltaic technology has attracted investors and influenced governments to establish public policies for the sector. The present research consisted of studying, building and testing low concentration solar radiation systems for photovoltaic energy conversion. The study used optical nonimaging parameters for the V-trough type radiation concentrator constructed of anodized aluminum, to reflect and to cool. Designed to concentrate radiation by about two times and consisting of a set of photovoltaic modules connected in parallel, they were modeled in the Laboratory of Energy Area in the Department of Agricultural Engineering of the Federal University of Vicosa, Brazil, at the coordinates 20°45′14′′ S latitude, 42°52′53′′ W longitude and altitude 648.74 m. They were installed to the geographic North, with the same slope as the local latitude. For comparative analysis, it was determined the electrical characteristics for evaluation of the prototype’s performance with and without radiation concentration, the final productivity for cities in tropical and temperate regions and economic analysis for the system. It was concluded that the prototypes allowed for a gain of energy with concentration, about 31.3% more, and therefore a productivity gain for the analyzed cities in, kWh·kWp−1.

Challenge of high energy radiation dosimetry and protection

International Nuclear Information System (INIS)

Nelson, W.R.; Jenkins, T.M.

1976-08-01

An accelerator health physicist can make contributions in many fields of science in addition to the various operational tasks that he is charged with. He can support others in his laboratory by designing shielding for new accelerators and storage rings, by consulting with experimenters on background radiation problems that they may encounter, by helping the high energy physicist select appropriate radiation sources for checking out his equipment, by providing him with low energy atomic and nuclear physics calculations, and many other ways. Most of all, he can perform and publish research using the many tools and techniques that are at his disposal at a high-energy accelerator laboratory

System of regional centres of first aid in cases of radiation accidents in Germany

International Nuclear Information System (INIS)

Fehringer, F.; Seitz, G.

1996-01-01

When in the seventies the number of occupational radiation exposed persons in the Federal Republic of Germany increased from about 35,000 (1974) to about 160,000 (1978) the Industrial Injuries Insurance Institutes felt prompted to reflect about special measures to prevent radiation accidents and provide health care for this special cases. They did so without any actual occasion: accidents were persons have been exposed by ionizing radiation were in the seventies just as rare as today. But that fact does not allow the Industrial Injuries Insurance Institutes to neglect the existing potential for severe accidents. So the Industrial Injuries Insurance Institute for the Electrical Industry including Precision Mechanics and the Industrial Injuries Insurance Institute for the Chemical Industry created the Institute for Radiation Protection in 1978. The primary task of that Institute is to guarantee an effective first aid in the case of a radiation accident. To realize that task the Institute contracted 11 wellknown institutions like radiological departments of large hospitals or the medical departments of research centres where the i knowledge on diagnostic and therapy of radiation effects is present. They are called 'Regionale Strahlenschutzzentren', Regional Centres for Radiation Protection (RCRP). In the case of radiation accidents these RCRP are the logistical centres for all arising questions of treatment. They have facilities for reconstructing exposure situations and assessing and evaluating doses, including measurements of internal contamination as well as for medical inpatient or out-patient treating like internal or external decontamination. Another important task of the RCRP is to advise employers in ad radiation protection questions which arise with the industrial application of ionizing radiation. Of course the centres give also answer to many question from members of the public, for example the personal effects of the power plant accident at Chernobyl

Identification of high-energetic particles by transition radiation

International Nuclear Information System (INIS)

Struczinski, W.

1986-01-01

This thesis gives a comprehensive survey on the application of the transition radiation for the particle identification. After a short historical review on the prediction and the detection of the transition radiation its theoretical foundations are more precisely explained. They form the foundations for the construction of an optimal transition radiation detector the principal construction of which is described. The next chapter shows some experiments by which the main predictions of the transition-radiation theory are confirmed. Then the construction and operation of two transition-radiation detectors are described which were applied at the ISR respectively SPS in the CERN in Geneva in complex experiments. The detector applied at the ISR served for the e ± identification. With two lithium radiators which were followed by xenon-filled proportional chambers an e/π separation of ≅ 10 -2 could be reached. The transition-radiation detector applied in the SPS was integrated into the European Hybrid Spectrometer. It served for the identification of high-energetic pions (> or approx. 90 GeV) against kaons and protons. With twenty units of carbon-fiber radiators which were followed by xenon-filled proportional chambers a π/K, p separation of better than 1:20 for momenta above 100 GeV could be reached. The cluster-counting method is then presented. Finally, a survey on the contemporary status in the development of transition-radiation detectors for the e/π separation is given. It is shown that by an about half a meter long detector the radiators of which consist of carbon fibers an e/π separation in the order of magnitude of ≅ 10 -2 can be reached. (orig./HSI) [de

Sensitivity of regional meteorology and atmospheric composition during the DISCOVER-AQ period to subgrid-scale cloud-radiation interactions

Science.gov (United States)

Huang, X.; Allen, D. J.; Herwehe, J. A.; Alapaty, K. V.; Loughner, C.; Pickering, K. E.

2014-12-01

Subgrid-scale cloudiness directly influences global and regional atmospheric radiation budgets by attenuating shortwave radiation, leading to suppressed convection, decreased surface precipitation as well as other meteorological parameter changes. We use the latest version of WRF (v3.6, Apr 2014), which incorporates the Kain-Fritsch (KF) convective parameterization to provide subgrid-scale cloud fraction and condensate feedback to the rapid radiative transfer model-global (RRTMG) shortwave and longwave radiation schemes. We apply the KF scheme to simulate the DISCOVER-AQ Maryland field campaign (July 2011), and compare the sensitivity of meteorological parameters to the control run that does not include subgrid cloudiness. Furthermore, we will examine the chemical impact from subgrid cloudiness using a regional chemical transport model (CMAQ). There are several meteorological parameters influenced by subgrid cumulus clouds that are very important to air quality modeling, including changes in surface temperature that impact biogenic emission rates; changes in PBL depth that affect pollutant concentrations; and changes in surface humidity levels that impact peroxide-related reactions. Additionally, subgrid cumulus clouds directly impact air pollutant concentrations by modulating photochemistry and vertical mixing. Finally, we will compare with DISCOVER-AQ flight observation data and evaluate how well this off-line CMAQ simulation driven by WRF with the KF scheme simulates the effects of regional convection on atmospheric composition.

Radiation susceptibility of the mouse smalleye mutants, Del(2)Sey3Hpax6 and Del(2)Sey4Hpax6, which delete the chromosome 2 middle regions

International Nuclear Information System (INIS)

Nitta, Y.; Hoshi, M.; Yoshida, K.; Yamate, J.; Peters, J.; Cattanach, B.M.

2003-01-01

Full text: LOH at the chromosome 2 middle regions is common in the radiation-induced mouse acute myeloid leukemia (AML). To identify the suppressor or the modifier gene of AML at this region, the mouse deletion mutants, Del(2)Sey3H pax6 and Del(2)Sey3H pax6 could be the good models, as they deleted the chromosome 2 middle regions hemizygously. The allele of the partially deleted chromosome 2 was paternally generated and maintained hemizygously. The exact deleted regions of the two mutants were mapped by the PCR-based detection of polymorphism of the STS markers. The length of the deletions was 3.01Mb and 10.11MB for Del(2)Sey3H pax6 and Del(2)Sey3H pax6 , respectively. For the induction of tumors, a radiation, 3.0Gy of Co-60 and a chemical carcinogen, N-methyl-N-nitrosourea were applied to the mutants. Their tumorigenicity was compared with those of control as well as normal sibs by the Kaplan-Meier analysis. Both mutants were found to predispose to small intestinal tumors. Intestinal tumors developed spontaneously with the incidence of 30%. The radiation and the chemical accelerated the malignancy and increased the incidence of the intestinal tumors. Radiation shortened the latency of AML development in the Del(2)Sey3H pax6 mutant but not in the Del(2)Sey3H pax6 . Spontaneous AML has not been observed, nor any increase in the incidence of induced AMLs. The commonly deleted region of the two mutants, the 3.01Mb region, must be critical for the development of tumors and the high susceptibility to radiation. The role of Pax6 gene should be considered in the intestinal tumorigenesis, as the Pax6 gene plays an important role in the pancreas development during the embryogenesis. The Wt1, a tumor suppressor gene, which is deleted hemizygously in these mutants as well. The screening of homozygous deletion has been started using the induced as well as spontaneously developed tumors

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)

Polonium-210 and Lead-210 in marine biota from a coastal region with high natural radioactivity

International Nuclear Information System (INIS)

Zafrul Kabir, M.; Deeba, Farah; Hossain, Sushmita; Fharim, Massoud; Md Moniruzzaman; Carvalho, Fernando P.; Oliveira, João M.; Malta, M.; Silva, L.

2013-01-01

Coastal sediments and marine fish from a region with high natural radioactivity in Cox Bazar Bangladesh, were analyzed in order to investigate the levels of naturally occurring radionuclides. Sediment from the sea shore in high ambient radiation dose rate areas contained naturally occurring radionuclides at high concentrations. These sediments displayed 226 Ra, 232 Th and 235 U activity concentrations of 2184 ± 88 Bq kg -1 dry weight (d.w.), 3808 ± 200 Bq kg -1 (d.w.) and 123 ± 15 Bq kg -1 (d.w.), respectively. In contrast with these high values, radionuclide concentrations in sand from other areas of the Cox's Bazar coast were as low as 42 ± 3, 70 ± 4 and < 8 Bq kg -1 (d.w.) for the same radionuclides, respectively, which are comparable to concentrations determined in many coastal areas elsewhere. The presence of sand deposits with high concentration of uranium series radionuclides could potentially originate high accumulation of alpha emitting radionuclides such as 210 Po in marine biota, and food chain transfer to man. 210 Po is a major contributor to the radiation dose both in marine organisms and sea food consumers. Determination of 210 Po in marine fish and shrimp from the area lead to concentration values ranging from 4.5±0.3 to 124±3 Bq kg -1 (d.w.) in fish and 82.9±1.6 Bq kg -1 (d.w.) in shrimp. Similar concentrations are commonly reported in marine biota from several regions. Therefore, in spite of the deposits of heavy mineral sands containing high concentrations of radionuclides such as 210 Pb and 210 Po no significant raise in the accumulation of these radionuclides in biota seems to occur, which suggests that radionuclides are tightly bound in sediment grains and are not significantly bioavailable. (author)

Application of TSEE characteristics to high energy radiation dosimetry around an electron linear accelerator

International Nuclear Information System (INIS)

Yamamoto, T.; Nakasaku, S.; Kawanishi, M.

1986-01-01

The response of the exoelectron dosemeter to the absorbed dose has been investigated with the LiF sample irradiated with high energy electrons from a linear accelerator and γ rays from a 60 Co source. The energy absorbed in the thin surface layer, which can be related to the origins of exoelectron emission, is, in general, smaller than the energy liberated there by primary radiation. In this paper the surface dose is calculated by the Monte Carlo Code EGS4. It is pointed out that the air layer in front of the sample also plays an important role by supplying secondary electrons to the surface region of the sample. The emission density of exoelectrons from a LiF single crystal for unit absorbed dose is found to be 5 x 10 4 electrons.cm -2 .Gy -1 , and nearly constant independent of the low LET radiation type. (author)

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

International Nuclear Information System (INIS)

Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon

2002-01-01

transected into transverse 36 slices of 2.5cm thickness. Photon dose was measured using a Capintec PR-06C ionization chamber with Capintec 192 electrometer (Capintec Inc., Ramsey, NJ), TLD(VICTOREEN 5000. LiF) and film dosimetry V-Omat, Kodak). In case of fetus, the dosimeter was placed at a depth of 10cm in this phantom at 100cm source to axis distance and located centrally 15cm from the inferior edge of the 30cm x 30cm 2 x-ray beam irradiating the Rando phantom chest wall. A acryl bridge of size 40 cm x 40 cm 2 and a clear space of about 20 cm was fabricated and placed on top of the rectangular polystyrene phantom representing the abdomen of the patient. The lead pot for testicle shielding was made as various shape, sizes, thickness and supporting stand. The scattered photon with and without shielding were measured at the representative position of the fetus and testicle. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large field of high energy radiation beam was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5 - 10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the fetus and testicle from thorax field irradiation was measured about 1 mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks. Lead pot shield for testicle reduced the scatter dose under 10 mGy when photon beam of 60 Gy was irradiated in abdomen region. The scattered photon dose is reduced when the lead shield was used while the no significant reduction of scattered photon dose was observed and 2-3 mm lead sheets reduced the skin dose under 80% and almost electron contamination. The results indicate that it was possible to improve shielding to reduce scattered photon for fetus and testicle when a young patients

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon [Yonsei Univ., Seoul (Korea, Republic of)

2002-03-15

transected into transverse 36 slices of 2.5cm thickness. Photon dose was measured using a Capintec PR-06C ionization chamber with Capintec 192 electrometer (Capintec Inc., Ramsey, NJ), TLD(VICTOREEN 5000. LiF) and film dosimetry V-Omat, Kodak). In case of fetus, the dosimeter was placed at a depth of 10cm in this phantom at 100cm source to axis distance and located centrally 15cm from the inferior edge of the 30cm x 30cm{sup 2} x-ray beam irradiating the Rando phantom chest wall. A acryl bridge of size 40 cm x 40 cm{sup 2} and a clear space of about 20 cm was fabricated and placed on top of the rectangular polystyrene phantom representing the abdomen of the patient. The lead pot for testicle shielding was made as various shape, sizes, thickness and supporting stand. The scattered photon with and without shielding were measured at the representative position of the fetus and testicle. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large field of high energy radiation beam was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5 - 10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the fetus and testicle from thorax field irradiation was measured about 1 mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks. Lead pot shield for testicle reduced the scatter dose under 10 mGy when photon beam of 60 Gy was irradiated in abdomen region. The scattered photon dose is reduced when the lead shield was used while the no significant reduction of scattered photon dose was observed and 2-3 mm lead sheets reduced the skin dose under 80% and almost electron contamination. The results indicate that it was possible to improve shielding to reduce scattered photon for fetus and testicle when a young

Biological fingerprint of high LET radiation. Brenner hypothesis

International Nuclear Information System (INIS)

Kodama, Yoshiaki; Awa, Akio; Nakamura, Nori

1997-01-01

Hypothesis by Brenner et al. (1994) that in chromosome aberrations in human peripheral lymphocytes induced by radiation exposure, F value (dicentrics/rings) differs dependently on the LET and can be a biomarker of high LET radiation like neutron and α-ray was reviewed and evaluated as follows. Radiation and chromosome aberrations; in this section, unstable aberrations like dicentric and rings (r) and stable ones like translocation and pericentric inversions were described. F value. Brenner hypothesis. Bauchinger's refutation. F value determined by FISH method; here, FISH is fluorescence in situ hybridization. F value in studies by author's Radiation Effect Research Facility. Frequency of chromosome aberration in A-bomb survivors and ESR (ESR: electron spin resonance). The cause for fluctuation of F values. The Brenner hypothesis could not be supported by studies by author's facility, suggesting that the rate of inter-chromosomal and intra-chromosomal exchange abnormalities can not be distinguishable by the radiation LET. This might be derived from the difference in detection technology of r rather than in LET. (K.H.)

Proceedings of the 3. Regional Meeting on Radiological and Nuclear Safety, Regional Meeting on International Radiation Protection Association (IRPA)and 3. Peruvian Meeting on Radiological Protection

International Nuclear Information System (INIS)

1995-10-01

There we show works of the Third Regional Meeting on Radiological and Nuclear Safety held on 23-27 October, 1995 in Cusco-Peru. Latin americans specialists talk about nuclear safety and radiological protection, radiation natural exposure, biological effect of radiation, radiotherapy and medical radiological safety, radiological safety in industry and research. Also we deal with subjects related to radiological safety of nuclear and radioactive facilities, radioactive waste management, radioactive material transport, environmental radiological monitoring program, radiological emergency and accidents, instruments and dosimetry, basic safety standards of protection against radiation. More than 225 works were presented on the meeting

Properties of Highly Rotationally Excited H2 in Photodissociation Regions

Science.gov (United States)

Cummings, Sally Jane; Wan, Yier; Stancil, Phillip C.; Yang, Benhui H.; Zhang, Ziwei

2018-06-01

H2 is the dominant molecular species in the vast majority of interstellar environments and it plays a crucial role as a radiative coolant. In photodissociation regions, it is one of the primary emitters in the near to mid-infrared which are due to lines originating from highly excited rotational levels. However, collisional data for rotational levels j>10 are sparse, particularly for H2-H2 collisions. Utilizing new calculations for para-H2 and ortho-H2 collisional rate coefficients with H2 for j as high as 30, we investigate the effects of the new results in standard PDR models with the spectral simulation package Cloudy. We also perform Cloudy models of the Orion Bar and use Radex to explore rotational line ratio diagnostics. The resulting dataset of H2 collisional data should find wide application to other molecular environments. This work was support by Hubble Space Telescope grant HST-AR-13899.001-A and NASA grants NNX15AI61G and NNX16AF09G.

Radiation and the hypothalamic-pituitary axis

International Nuclear Information System (INIS)

Littley, M.D.; Shalet, S.M.; Beardwell, C.G.

1991-01-01

This paper reports on radiation therapy which is an essential treatment in the management of many conditions. It is important to appreciate the high incidence of subsequent endocrine morbidity, however, if the hypothalamic pituitary region is within the radiation fields. This is very much more common with external radiation therapy than with other forms of radiation treatment. The dose and fractional of administered radiation are important determinants of the endocrine deficits, their time on onset, and severity. Irradiation of large volumes of brain and hypothalamus may increase the risk of hormonal abnormalities as may preceding surgery in the treatment of pituitary disease. The phenomena observed in children and adults illustrate that there may be damage to pituitary, hypothalamus, and higher centers. In patients who have received a significant radiation dose to the hypothalamic-pituitary region, regular follow-up is mandatory. In adults, surveillance will include pituitary function testing on an annual basis for at least 10 years. In children careful monitoring of growth and pubertal development and early treatment of radiation-induced GH deficiency are vital

ELBE Center for High-Power Radiation Sources

Directory of Open Access Journals (Sweden)

Peter Dr. Michel

2016-01-01

Full Text Available In the ELBE Center for High-Power Radiation Sources, the superconducting linear electron accelerator ELBE, serving  two free electron lasers, sources for intense coherent THz radiation, mono-energetic positrons, electrons, γ-rays, a neutron time-of-flight system as well as two synchronized ultra-short pulsed Petawatt laser systems are collocated. The characteristics of these beams make the ELBE center a unique research instrument for a variety of external users in fields ranging from material science over nuclear physics to cancer research, as well as scientists of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR.

Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

International Nuclear Information System (INIS)

Ramola, R. C.; Gusain, G. S.; Rautela, B. S.; Sagar, D. V.; Prasad, G.; Shahoo, S. K.; Ishikawa, T.; Omori, Y.; Janik, M.; Sorimachi, A.; Tokonami, S.

2012-01-01

Exposure to radon, 222 Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, 220 Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to 220 Rn and its progeny can equal or several time exceed that of 220 Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha (India)) presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper. (authors)

Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

Energy Technology Data Exchange (ETDEWEB)

Ramola, R C; Gusain, G S; Rautela, B S [Dept. of Physics, H.N.B. Garhwal Univ., Badshahi Thaul Campus, Tehri Garhwal 249199 (India); Sagar, D V [Health Physics Unit EAD, BARC, IRE, OSCOM, Matikhalo, Ganjam, Odisha 761 045 (India); Prasad, G; Shahoo, S K; Ishikawa, T; Omori, Y; Janik, M [National Inst. of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Sorimachi, A; Tokonami, S [Inst. of Radiation Emergency Medicine, Hirosaki Univ., Aomori 036-8564 (Japan)

2012-07-01

Exposure to radon, {sup 222}Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, {sup 220}Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to {sup 220}Rn and its progeny can equal or several time exceed that of {sup 220}Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha (India)) presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper. (authors)

Human exposure to high natural background radiation: what can it teach us about radiation risks?

International Nuclear Information System (INIS)

Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner; Simon, Steven L; Wojcik, Andrzej; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

2009-01-01

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222 Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

Human exposure to high natural background radiation: what can it teach us about radiation risks?

Science.gov (United States)

Hendry, Jolyon H; Simon, Steven L; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

2014-01-01

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case–control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case–control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors. PMID:19454802

Human exposure to high natural background radiation: what can it teach us about radiation risks?

Energy Technology Data Exchange (ETDEWEB)

Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner [Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna (Austria); Simon, Steven L [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Wojcik, Andrzej [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Cardis, Elisabeth [Centre for Research in Environmental Epidemiology (CREAL), Municipal Institute of Medical Research (IMIM-Hospital del Mar) and CIBER Epidemiologia y Salud Publica - CIBERESP, Barcelona (Spain); Laurier, Dominique; Tirmarche, Margot [Radiobiology and Epidemiology Department, Radiological and Human Health Division, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses (France); Hayata, Isamu [National Institute of Radiological Sciences, Chiba (Japan)], E-mail: jhendry2002uk@yahoo.com

2009-06-01

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of {sup 222}Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

Lightweight Damage Tolerant, High-Temperature Radiators for Nuclear Power and Propulsion

Science.gov (United States)

Craven, Paul D.; SanSoucie, Michael P.

2015-01-01

NASA is increasingly emphasizing exploration to bodies beyond near-Earth orbit. New propulsion systems and new spacecraft are being built for these missions. As the target bodies get further out from Earth, high energy density systems, e.g., nuclear fusion, for propulsion and power will be advantageous. The mass and size of these systems, including supporting systems such as the heat exchange system, including thermal radiators, will need to be as small as possible. Conventional heat exchange systems are a significant portion of the total thermal management mass and size. Nuclear electric propulsion (NEP) is a promising option for high-speed, in-space travel due to the high energy density of nuclear fission power sources and efficient electric thrusters. Heat from the reactor is converted to power for use in propulsion or for system power. The heat not used in the power conversion is then radiated to space as shown in figure 1. Advanced power conversion technologies will require high operating temperatures and would benefit from lightweight radiator materials. Radiator performance dictates power output for nuclear electric propulsion systems. Pitch-based carbon fiber materials have the potential to offer significant improvements in operating temperature, thermal conductivity, and mass. These properties combine to allow significant decreases in the total mass of the radiators and significant increases in the operating temperature of the fins. A Center-funded project at NASA Marshall Space Flight Center has shown that high thermal conductivity, woven carbon fiber fins with no matrix material, can be used to dissipate waste heat from NEP systems and because of high specific power (kW/kg), will require less mass and possibly less total area than standard metal and composite radiator fins for radiating the same amount of heat. This project uses an innovative approach to reduce the mass and size required for the thermal radiators to the point that in-space NEP and power

Further investigation on chromosome aberrations in lymphocytes of inhabitants in high background radiation area in Yangjiang

International Nuclear Information System (INIS)

Chen Deqing; Zhang Chaoyang; Yao Suyan

1985-01-01

Blood samples were taken from 122 healthy secondary school students at the age of 15 to 16 living in a high background radiation region and from 99 controls, All subjects from both areas had lived there since their births; they were non-smokers and without history of exposure to medical X-rays. The youngsters of 15 to 16 years old who were native-born and grew up in the high background radiation area received approximately 3.5 rad more cumulative γ-ray exposure than those in the control area. For each individual 200 M-1 cells were analysed. The frequency of chromosome aberrations in the high background group was 0.47/100 cells, while that in the control group was 0.33/100 cells, the diffrence being statistically significant. The frequencies of acentrics (fragment, acentric ring and minute), dicentrics and stable aberrations (inversion and translocation) were 0.41, 0.021 and 0.045/100 cells respectively in the high background group, and 0.30, 0.020 and 0.005/100 cells respectively in the control group. Only the difference of stable aberrations between the two groups was significant

Direct and semi-direct aerosol radiative effect on the Mediterranean climate variability using a coupled regional climate system model

Science.gov (United States)

Nabat, Pierre; Somot, Samuel; Mallet, Marc; Sevault, Florence; Chiacchio, Marc; Wild, Martin

2015-02-01

A fully coupled regional climate system model (CNRM-RCSM4) has been used over the Mediterranean region to investigate the direct and semi-direct effects of aerosols, but also their role in the radiation-atmosphere-ocean interactions through multi-annual ensemble simulations (2003-2009) with and without aerosols and ocean-atmosphere coupling. Aerosols have been taken into account in CNRM-RCSM4 through realistic interannual monthly AOD climatologies. An evaluation of the model has been achieved, against various observations for meteorological parameters, and has shown the ability of CNRM-RCSM4 to reproduce the main patterns of the Mediterranean climate despite some biases in sea surface temperature (SST), radiation and cloud cover. The results concerning the aerosol radiative effects show a negative surface forcing on average because of the absorption and scattering of the incident radiation. The SW surface direct effect is on average -20.9 Wm-2 over the Mediterranean Sea, -14.7 Wm-2 over Europe and -19.7 Wm-2 over northern Africa. The LW surface direct effect is weaker as only dust aerosols contribute (+4.8 Wm-2 over northern Africa). This direct effect is partly counterbalanced by a positive semi-direct radiative effect over the Mediterranean Sea (+5.7 Wm-2 on average) and Europe (+5.0 Wm-2) due to changes in cloud cover and atmospheric circulation. The total aerosol effect is consequently negative at the surface and responsible for a decrease in land (on average -0.4 °C over Europe, and -0.5 °C over northern Africa) and sea surface temperature (on average -0.5 °C for the Mediterranean SST). In addition, the latent heat loss is shown to be weaker (-11.0 Wm-2) in the presence of aerosols, resulting in a decrease in specific humidity in the lower troposphere, and a reduction in cloud cover and precipitation. Simulations also indicate that dust aerosols warm the troposphere by absorbing solar radiation, and prevent radiation from reaching the surface, thus

THE MAIN TRENDS OF INTERACTION BETWEEN THE ADMINISTRATION OF ROSPOTREBNADZOR IN THE LENINGRAD REGION AND THE GOVERNMENT OF LENINGRAD REGION IN THE FIELD OF POPULATION RADIATION PROTECTION

Directory of Open Access Journals (Sweden)

S. A. Gorbanev

2008-01-01

Full Text Available The article gives the main interaction trends of the Administration of Rospotrebnadzor in the Leningrad Region and the Government of Leningrad Region regarding issues of regional radiation protection. It reports on comprehensive measures devoted to the limitation of the population exposure from natural irradiation sources, monitoring of territories which suffered from Chernobyl NPP accident and monitoring of the environmental impact of unauthorized dumps and solid municipal waste sites in the Leningrad Region. It presents the basic issues of medical exposure limitation in the Leningrad Region and measures for their solving.

Selection and construction of nuclear and radiation emergency medical center in a region

International Nuclear Information System (INIS)

Wang Guojun; He Xu; Liao Li; Gao Dong

2014-01-01

Three level of first-class comprehensive hospital is an important force of nuclear and radiation accident rescue, has a very rich experience in response to nuclear and radiation accidents and deal with large quantities of the sick and wounded. With the foundation and the ability of the construction and operation of medical emergency rescue center. This paper according to the median model location theory of emergency center, combined with the specific situation of the nuclear and radiation accident in Hunan Province, reference location, rescue experience, emergency allocation of resources, teaching and research capacity, establish regional medical emergency center of nuclear and radiation accidents based on three level of first-class comprehensive hospital, break the traditional concept that the center must be provincial capital,form a multi-level, three-dimensional, network of emergency hospital rescue system. The main duties of the center are accident emergency response, on-site treatment and technical guidance of accident, psychological grooming. The author propose building measures according to the duties of the center: increase national and provincial financial investment, carry out training, drills and first aid knowledge missionaries regularly, innovative materials management, speed up the construction of information platform, establish and improve the hospital rescue system, improve organization institution and system of plans, reengineering rescue process. (authors)

Radiation-damage studies, irradiations and high-dose dosimetry for LHC detectors

CERN Document Server

Coninckx, F; León-Florián, E; Leutz, H; Schönbacher, Helmut; Sonderegger, P; Tavlet, Marc; Sopko, B; Henschel, H; Schmidt, H U; Boden, A; Bräunig, D; Wulf, F; Cramariuc, R; Ilie, D; Fattibene, P; Onori, S; Miljanic, S; Paic, G; Razen, B; Razem, D; Rendic, D; CERN. Geneva. Detector Research and Development Committee

1991-01-01

The proposal is divided into a main project and special projects. The main project consists of a service similar to the one given in the past to accelerator construction projects at CERN (ISR,SPS,LEP) on high-dose dosimetry, material irradiations, irradiations tests, standardization of test procedures and data compilations. Large experience in this field and numerous radiation damage test data of insulating and structural materials are available. The special projects cover three topics which are of specific interest for LHC detector physicists and engineers at CERN and in other high energy physics institutes, namely: Radiation effects in scintillators; Selection of radiation hard optical fibres for data transmission; and Selection and testing of radiation hard electronic components.

Review of high bandwidth fiber optics radiation sensors

International Nuclear Information System (INIS)

Lyons, P.B.

1985-01-01

This paper summarizes the use of fiber optics or guided optical systems for radiation sensors. It is limited a passive systems wherein electrical is not required at the sensor location. However, electrically powered light sources, receivers and/or recorders may still be required for detection and data storage in sensor system operation. This paper emphasizes sensor technologies that permit high bandwidth measurements of transient radiation levels, and will also discuss several low bandwidth applications. 60 refs

Magnitude of Solar Radiation Torque in the Transition Region from the Umbra to the Dark Shadow of the Earth

International Nuclear Information System (INIS)

Cabette, R E S; Kolesnikov, I; Zanardi, M C

2015-01-01

The analysis of solar radiation pressure force and its influence on the motion of artificial satellites has been developed by researchers. Accurate models to describe the influence of the Earth's shadow on the torque and force due to solar radiation pressure have been presented. In this work the solar radiation torque (SRT) and its influence on the attitude of an artificial satellite are taken into account by the introduction of the Earth's shadow function in the equations of motion. This function assumes a unitary value when the satellite is in the fully illuminated region of its orbit, and the value zero for the full shade region. The main objective of this study is to analyze the magnitude of SRT using the equations described by quaternions during a 35 day period and to compare the results with the satellite transition through the shadow region and the time interval in this region. The duration and transition through the shadow region were obtained using the software 'Shadow Conditions of Earth Satellites'. The formulation is applied to the Brazilian Data Collection Satellites SCD1 and SCD2, and the torque model is presented in terms of the satellite attitude quaternion, distance of the satellite to the Sun, orbital elements, right ascension and declination of the Sun. (paper)

REDUCING THE IMPACT OF RADIATION FACTORS IN AREAS WITH HIGH LEVEL OF RISK

Directory of Open Access Journals (Sweden)

D. A. Zaredinov

2015-01-01

Full Text Available The article is devoted to the modern problems of radioecology. The study reveals the problems of radioecological situation in some regions of the Republic of Uzbekistan. The main attention of the authors is paid to the ecologically hazardous objects in the uranium mining industry. The characteristics of wastes from uranium mining and stages of development of the mining industry are described. The historical background of the accumulation of the wastes in dumps, the ore-bearing rocks, and other off-balance ores is given. The practical experience and directions radio-ecological safety are generalized, achieving improvements of the environmental quality in areas with high risk. In conclusion, the authors recommend carrying out some measures to reduce an impact of the radiation factor on human health and to stabilize the radioecological situation at the studied regions.

Radiation from an equilibrium CO2-N2 plasma in the [250-850 nm] spectral region: II. Spectral modelling

International Nuclear Information System (INIS)

Silva, M Lino da; Vacher, D; Andre, P; Faure, G; Dudeck, M

2008-01-01

In the first part of this work, described in a previous paper, the thermodynamic conditions in an atmospheric pressure inductively coupled CO 2 -N 2 plasma have been determined, and the radiation emission spectrum has been measured and calibrated in the [250-850 nm] spectral region. In the second part of this work, a synthetic radiation spectrum is obtained taking into account (a) the geometry of the plasma torch and (b) the local thermodynamic conditions of the plasma. This synthetic spectrum has then been compared against the measured spectrum. The good agreement between the two spectra allows validating the spectral database of the line-by-line code SPARTAN for the simulation of the radiative emission of CO 2 -N 2 plasmas from the near-UV to the near-IR spectral region.

Theory of the high base resistivity n(+)pp(+) silicon solar cell and its application to radiation damage effects

Science.gov (United States)

Goradia, C.; Weinberg, I.

1985-01-01

Particulate radiation in space is a principal source of silicon solar cell degradation, and an investigation of cell radiation damage at higher base resistivities appears to have implication toward increasing solar cell and, therefore, useful satellite lifetimes in the space environment. However, contrary to expectations, it has been found that for cells with resistivities of 84 and 1250 ohm cm, the radiation resistance decreases as cell base resistivity increases. An analytical solar-cell computer model was developed with the objective to determine the reasons for this unexpected behavior. The present paper has the aim to describe the analytical model and its use in interpreting the behavior, under irradiation, of high-resistivity solar cells. Attention is given to boundary conditions at the space-charge region edges, cell currents, cell voltages, the generation of the theoretical I-V characteristic, experimental results, and computer calculations.

Mesoscale Modeling of Smoke Particles Distribution and Their Radiative Feedback over Northern Sub-Saharan African Region

Science.gov (United States)

Yue, Y.; Wang, J.; Ichoku, C. M.; Ellison, L.

2015-12-01

Stretching from southern boundary of Sahara to the equator and expanding west to east from Atlantic Ocean coasts to the India Ocean coasts, the northern sub-Saharan African (NSSA) region has been subject to intense biomass burning. Comprised of savanna, shrub, tropical forest and a number of agricultural crops, the extensive fires burn belt covers central and south of NSSA during dry season (from October to March) contributes to one of the highest biomass burning rate per km2 in the world. Due to smoke particles' absorption effects of solar radiation, they can modify the surface and atmosphere temperature and thus change atmospheric stability, height of the boundary layer, regional atmospheric circulation, evaporation rate, cloud formation, and precipitation. Hence, smoke particles emitted from biomass burning over NSSA region has a significant influence to the air quality, weather and climate variability. In this study, the first version of this Fire Energetics and Emissions Research (FEER.v1) emissions of several smoke constituents including light-absorbing organic carbon (OC) and black carbon (BC) are applied to a state-of-science meteorology-chemistry model as NOAA Weather Research and Forecasting Model with Chemistry (WRF-Chem). We analyzed WRF-Chem simulations of surface and vertical distribution of various pollutants and their direct radiative effects in conjunction with satellite observation data from Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar data with Orthogonal Polarization (CALIPSO) to strengthen the importance of combining space measured emission products like FEER.v1 emission inventory with mesoscale model over intense biomass burning region, especially in area where ground-based air-quality and radiation-related observations are limited or absent.

IAEA regional basic professional training on radiation protection

International Nuclear Information System (INIS)

1998-01-01

This book contains the manuscripts of lectures of the Basic Professional Training Course on Radiation Protection which was organized and prepared on the basis of the standard syllabus put together in accordance with the recommendations of the International Basic safety standards for radiation protection against ionizing radiation and for safety of radiation sources (BSS). The course was intended to meet the educational and initial training requirements of personnel working in this field. The course is aimed at workers of a graduate level who are called on to take up position in the radiation protection field and who might someday become trainers in their home countries and institutions. Papers relevant to INIS are indexed separately

Computed tomography in radiation therapy planning: Thoracic region

International Nuclear Information System (INIS)

Seydel, H.G.; Zingas, A.; Haghbin, M.; Mondalek, P.; Smereka, R.

1983-01-01

With the explosive spread of computed tomographic (CT) scanning throughout the United States, one of the main applications has been in patients who are treated for cancer by surgery, radiation therapy, or chemotherapy. For the radiation oncologist, the desire to provide local tumor control and avoid geographic misses to achieve an expected prolongation of survival has led to the use of large radiation fields in the treatment of intrathoracic cancer, including bronchogenic carcinoma, cancer of the esophagus, and other malignant tumors. The optimal radiation therapy plan is a balance between local tumor control and the necessity to preserve normal structures by the use of directed and limited fields for bulk disease. CT scanning has been employed to accurately demonstrate the extent of tumor as well as to determine the isodose distribution of radiation, including the spatial distribution of radiation portals in single planar and three-dimensional aspects as well as consideration of tissue inhomogeneities. The accurate planning of the distribution of therapeutic irradiation includes both the tumor-bearing target volume and the critical normal tissues. This chapter provides information regarding these aspects of the application of CT scanning to radiation therapy for bronchogenic carcinoma and carcinoma of the esophagus

Short and long term ionizing radiation effects on charge-coupled devices in radiation environment of high-intensity heavy ion accelerators

International Nuclear Information System (INIS)

Belousov, A; Mustafin, E; Ensinger, W

2012-01-01

Radiation effects on semiconductor devices is a topical issue for high-intensity accelerator projects. In particular it concerns Charge-Coupled Device (CCD) cameras, which are widely used for beam profile monitoring and surveillance in high radiation environment. One should have a clear idea of short and long term radiation effects on such devices. To study these effects, a CCD camera was placed in positions less than half meter away from beam loss point. Primary heavy ion beam of 0.95GeV/n Uranium was dumped into a thick aluminium target creating high fluences of secondary particles (e.g., gammas, neutrons, protons). Effects of these particles on CCD camera were scored with LabView based acquisition software. Monte Carlo calculations with FLUKA code were performed to obtain fluence distributions for different particles and make relevant comparisons. Long term total ionising dose effects are represented by dark current increase, which was scored throughout experiment. Instant radiation effects are represented by creation of charge in CCD cells by ionising particles. Relation of this charge to beam intensity was obtained for different camera positions and fluences within 5 orders of magnitude ranges. With high intensities this charge is so high that it may dramatically influence data obtained from CCD camera used in high radiation environment. The linearity of described above relation confirms linear response of CCD to ionizing radiation. It gives an opportunity to find a new application to CCD cameras as beam loss monitors (BLM).

A real-time audit of radiation therapy in a regional cancer center

International Nuclear Information System (INIS)

Brundage, Michael D.; Dixon, Peter F.; Mackillop, William J.; Shelley, Wendy E.; Hayter, Charles; Paszat, Lawrence F.; Youssef, Youssef M.; Robins, Jean M.; McNamee, Anne; Cornell, Annette

1999-01-01

Purpose: To report the development, structure, and implementation of a real-time clinical radiotherapy audit of the practice of radiation oncology in a regional cancer center. Methods and Materials: Radiotherapy treatment plans were audited by a real-time peer-review process over an 8-year period (1989-1996). The overall goal of the audit was to establish a process for quality assurance (QA) of radiotherapy planning and prescription for individual patients. A parallel process was developed to audit the implementation of intervention-specific radiotherapy treatment policies. Results: A total of 3052 treatment plans were audited. Of these, 124 (4.1%) were not approved by the audit due to apparent errors in radiation planning. The majority of the nonapproved plans (79%) were modified prior to initiating treatment; the audit provided important clinical feedback about individual patient care in these instances. Most of the remaining nonapproved plans were deviations from normal practice due to patient-specific considerations. A further 110 (3.6% of all audited plans) were not approved by the audit due to deviations from radiotherapy treatment policy. A minority of these plans (22%) were modified prior to initiating treatment and the remainder provided important feedback for continuous quality improvement of treatment policies. Conclusion: A real-time audit of radiotherapy practice in a regional cancer center setting proved feasible and provided important direct and indirect patient benefits

Contamination of humans by radionuclides, global problem presented on region Vojvodina, city Novi Sad

International Nuclear Information System (INIS)

Vukovic, D.; Markovic, D.

2002-01-01

As interval data obtained results are in region of not high doses of radiation's there are short course, a little bit funny about low level radiation's, low dose radiation. Welcome to Hormesis and Radio adaptive Response Page,Radiation Hormesis, Dr. K.S. Parthasarathy exposure to high levels of ionizing radiation can harm the tissues of the human body. This has been demonstrated unequivocally

High-intensity coherent FIR radiation from sub-picosecond electron bunches

International Nuclear Information System (INIS)

Kung, P.H.; Lihn, Hung-chi; Wiedemann, H.; Bocek, D.

1994-01-01

A facility to generate high-intensity, ultra-short pulses of broad-band far-infrared radiation has been assembled and tested at Stanford. The device uses sub-picosecond relativistic electron bunches to generate coherent radiation through transition or synchrotron radiation in the far-infrared (FIR) regime between millimeter waves and wavelengths of about 100 μm and less. Experimental results show a peak radiation power of greater than 0.33 MW within a micro-bunch and an average FIR radiation power of 4 mW. The average bunch length of 2856 micro-bunches within a 1 μsec macro-pulse is estimated to be about 480 sec. Simulations experimental setup and results will be discussed

A geophysical tour of high background radiation areas of the world

International Nuclear Information System (INIS)

Krishnan, D.; Kher, R.K.; Nambi, K.S.V.

1995-01-01

A comparison of the findings including health effects in four major high natural background areas of the world are given. Such high background areas could prove to be a radiation ecology laboratory gifted by nature and provide further insight in the relation of radiation, natural or otherwise and human health. 3 refs., 2 tabs

Monolayer graphene dispersion and radiative cooling for high power LED

Science.gov (United States)

Hsiao, Tun-Jen; Eyassu, Tsehaye; Henderson, Kimberly; Kim, Taesam; Lin, Chhiu-Tsu

2013-10-01

Molecular fan, a radiative cooling by thin film, has been developed and its application for compact electronic devices has been evaluated. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate with the quantization of lattice modes in active nanomaterials. The highly quantized G and 2D bands in graphene are achieved by our dispersion technique, and then incorporated in an organic-inorganic acrylate emulsion to form a coating assembly on heat sinks (for LED and CPU). This water-based dielectric layer coating has been formulated and applied on metal core printed circuit boards. The heat dissipation efficiency and breakdown voltage are evaluated by a temperature-monitoring system and a high-voltage breakdown tester. The molecular fan coating on heat dissipation units is able to decrease the equilibrium junction temperature by 29.1 ° C, while functioning as a dielectric layer with a high breakdown voltage (>5 kV). The heat dissipation performance of the molecular fan coating applied on LED devices shows that the coated 50 W LED gives an enhanced cooling of 20% at constant light brightness. The schematics of monolayer graphene dispersion, undispersed graphene platelet, and continuous graphene sheet are illustrated and discussed to explain the mechanisms of radiative cooling, radiative/non-radiative, and non-radiative heat re-accumulation.

Monolayer graphene dispersion and radiative cooling for high power LED

International Nuclear Information System (INIS)

Hsiao, Tun-Jen; Eyassu, Tsehaye; Henderson, Kimberly; Kim, Taesam; Lin, Chhiu-Tsu

2013-01-01

Molecular fan, a radiative cooling by thin film, has been developed and its application for compact electronic devices has been evaluated. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate with the quantization of lattice modes in active nanomaterials. The highly quantized G and 2D bands in graphene are achieved by our dispersion technique, and then incorporated in an organic-inorganic acrylate emulsion to form a coating assembly on heat sinks (for LED and CPU). This water-based dielectric layer coating has been formulated and applied on metal core printed circuit boards. The heat dissipation efficiency and breakdown voltage are evaluated by a temperature-monitoring system and a high-voltage breakdown tester. The molecular fan coating on heat dissipation units is able to decrease the equilibrium junction temperature by 29.1 ° C, while functioning as a dielectric layer with a high breakdown voltage (>5 kV). The heat dissipation performance of the molecular fan coating applied on LED devices shows that the coated 50 W LED gives an enhanced cooling of 20% at constant light brightness. The schematics of monolayer graphene dispersion, undispersed graphene platelet, and continuous graphene sheet are illustrated and discussed to explain the mechanisms of radiative cooling, radiative/non-radiative, and non-radiative heat re-accumulation. (paper)

Epidemiological studies in the high and normal level radiation areas of Kerala

International Nuclear Information System (INIS)

Koya, P.K.M.

2012-01-01

High and normal level natural radiation areas of Kerala give unique opportunities to estimate the risk, if any, of chronic low dose exposure by direct epidemiological studies on human beings. Studies in the area are being carried out by Low Level Radiation Research Laboratory of Bhabha Atomic Research Centre in collaboration with Departments of Health and Family Welfare/Social Welfare of the Government of Kerala and local post graduate colleges. To assess the role of chronic low dose exposure in the induction/transmission of chromosomal alterations across generations, hospital based cytogenetic studies on newborns was carried out to estimate and compare the frequency of chromosomal aberrations and karyotypes anomalies in the high (areas with radiation dose of more than 1.50 mGy/year) and normal (areas with radiation dose of 1.50 mR/year or less) level radiation areas. A total of 1,267,788 metaphases from 27,295 (9,64,390 cells from 17,298 newborns of high and 3,03,398 cells from 9,997 newborns of normal level radiation areas) newborns was screened

Coherent spontaneous radiation from highly bunched electron beams

International Nuclear Information System (INIS)

Berryman, K.W.; Crosson, E.R.; Ricci, K.N.

1995-01-01

Coherent spontaneous radiation has now been observed in several FELs, and is a subject of great importance to the design of self-amplified spontaneous emission (SASE) devices. We report observations of coherent spontaneous radiation in both FIREFLY and the mid-infrared FEL at the Stanford Picosecond FEL Center. Coherent emission has been observed at wavelengths as short as 5 microns, and enhancement over incoherent levels by as much as a factor of 4x10 4 has been observed at longer wavelengths. The latter behavior was observed at 45 microns in FIREFLY with short bunches produced by off-peak acceleration and dispersive compression. We present temporal measurements of the highly bunched electron distributions responsible for the large enhancements, using both transition radiation and energy-phase techniques

Effects of low dose gamma radiation on the early growth of red pepper and the resistance to subsquent high dose of radiation

Energy Technology Data Exchange (ETDEWEB)

Kim, J. S.; Baek, M. H.; Kim, D. H.; Lee, Y. K. [KAERI, Taejon (Korea, Republic of); Lee, Y. B. [Chungnam National Univ., Taejon (Korea, Republic of)

2001-05-01

Red pepper (capsicum annuum L. cv. Jokwang and cv. Johong) seeds were irradiated with the dose of 0{approx}50 Gy to investigated the effect of the low dose gamma radiation on the early growth and resistance to subsequent high dose of radiation. The effect of the low dose gamma radiation on the early growth and resistance to subsequenct high dose of radiation were enhanced in Johong cultivar but not in Jokwang cultivar. Germination rate and early growth of Johong cultivar were noticeably increased at 4 Gy-, 8 Gy- and 20 Gy irradiation group. Resistance to subsequent high dose of radiation of Johong cultivar were increased at almost all of the low dose irradiation group. Especially it was highest at 4 Gy irradiation group. The carotenoid contents and enzyme activity on the resistance to subsequent high dose of radiation of Johong cultivar were increased at the 4 Gy and 8 Gy irradiation group.

High-dose preoperative radiation for cancer of the rectum: Impact of radiation dose on patterns of failure and survival

International Nuclear Information System (INIS)

Ahmad, N.R.; Mohiuddin, M.; Marks, G.

1993-01-01

A variety of dose-time schedules are currently used for preoperative radiation therapy of rectal cancer. An analysis of patients treated with high-dose preoperative radiation therapy was undertaken to determine the influence of radiation dose on the patterns of failure, survival, and complications. Two hundred seventy-five patients with localized rectal cancer were treated with high-dose preoperative radiation therapy. One hundred fifty-six patients received 45 Gy (low-dose group). Since 1985, 119 patients with clinically unfavorable cancers were given a higher dose, 55 Gy using a shrinking field technique (high-dose group). All patients underwent curative resection. Median follow-up was 66 months in the low-dose group and 28 months in the high-dose group. Patterns of failure, survival, and complications were analyzed as a function of radiation dose. Fourteen percent of the total group developed a local recurrence; 20% in the low-dose group as compared with 6% in the high-dose group. The actuarial local recurrence rate at 5 years was 20% for the low-dose group and 8% for the high-dose group, and approached statistical significance with p = .057. For tethered/fixed tumors the actuarial local recurrence rates at 5 years were 28% and 9%, respectively, with p = .05. Similarly, for low-lying tumors (less than 6 cm from the anorectal junction) the rates were 24% and 9%, respectively, with p = .04. The actuarial rate of distant metastasis was 28% in the low-dose group and 20% in the high-dose group and was not significantly different. Overall actuarial 5-year survival for the total group of patients was 66%. No significant difference in survival was observed between the two groups, despite the higher proportion of unfavorable cancers in the high-dose group. The incidence of complications was 2%, equally distributed between the two groups. High-dose preoperative radiation therapy for rectal cancer results in excellent local control rates. 27 refs., 2 figs., 8 tabs

1990-2016 surface solar radiation variability and trend over the Piedmont region (northwest Italy)

Science.gov (United States)

Manara, Veronica; Bassi, Manuela; Brunetti, Michele; Cagnazzi, Barbara; Maugeri, Maurizio

2018-05-01

A new surface solar radiation database of 74 daily series is set up for the Piedmont region (northwest Italy) for the 1990-2016 period. All the series are subjected to a detailed quality control, homogenization and gap-filling procedure and are transformed into relative annual/seasonal anomaly series. Finally, a gridded version (0.5°×0.5°) of the database is generated. The resulting series show an increasing tendency of about + 2.5% per decade at annual scale, with strongest trend in autumn (+ 4% per decade). The only exception is winter, showing a negative but not significant trend. Considering the plain and mountain mean series, the trends are more intense for low than for high elevations with a negative vertical gradient of about - 0.03% per decade per 100 m at annual scale and values up to - 0.07% per decade per 100 m in spring. Focusing on clear days only (selected by CM SAF ClOud fractional cover dataset from METeosat first and second generation—Edition 1 satellite data over the 1991-2015 period), trend significance strongly increases and both low and high elevation records exhibit a positive trend in all seasons. However, the trends result slightly lower than for all-sky days (with the only exception of winter). The differences observed under clear-sky conditions between low and high elevations are more pronounced in winter, where the trend shows a negative vertical gradient of about - 0.1% per decade every 100 m. Overall, this paper shows how a high station density allows performing a more detailed quality control thanks to the higher performances in detecting the inhomogeneities with higher data availability and capturing regional peculiarities otherwise impossible to observe.

Survey of cognition on nuclear and radiation in Beijing high school students

International Nuclear Information System (INIS)

Wang Chao; He Jianrong; Zhu Xiayang; Yang Guoliang; Cong Huiling; Hu Qinfang

2014-01-01

Objective: To explore cognition level on nuclear and radiation in Beijing high school students, which may provide evidence for promoting science popularization on nuclear and radiation. Methods: Questionnaire-based survey was conducted in Beijing high school students, randomized cluster sampling was used to recruit study participants. Demographic information was collected, and cognition level on nuclear and radiation was evaluated by questionnaire. Results: A total of 1029 pieces of eligible questionnaires were collected. The correct rate for answering common sense about nuclear and radiation was 58%, with score of boys significantly higher than that of girls (t = 4.131, P < 0.05). About subjective cognition of nuclear and radiation knowledge, 87 (8.5%) indicated 'quite clear', 779 (75.7%) indicated 'know a little', 163 (15.8%) indicated 'know nothing'. There was significant difference in score of common sense about nuclear and radiation among people with various subjective cognition level of nuclear and radiation (J-T = 8.279, P < 0.05). There was a linear correlation between support degree for nuclear power and subjective cognition level of nuclear and radiation (r = 0.161, P < 0.05). There was significant difference in score of common sense about nuclear and radiation among people with various support degree for nuclear power (J-T = 7.508, P < 0.05), whereas those who had got high scores tended to support nuclear power to a higher degree. Conclutions: Students knew little about knowledge on nuclear and radiation. It is necessary to strengthen propaganda and education on nuclear and radiation, which may help enhance the students' comprehensive quality, and sustainable expansion of nuclear power more support in the long run. (authors)

Calibration and Evaluation of Different Estimation Models of Daily Solar Radiation in Seasonally and Annual Time Steps in Shiraz Region

Directory of Open Access Journals (Sweden)

Hamid Reza Fooladmand

2017-06-01

2006 to 2008 were used for calibrating fourteen estimated models of solar radiation in seasonally and annual time steps and the measured data of years 2009 and 2010 were used for evaluating the obtained results. The equations were used in this study divided into three groups contains: 1 The equations based on only sunshine hours. 2 The equations based on only air temperature. 3 The equations based on sunshine hours and air temperature together. On the other hand, statistical comparison must be done to select the best equation for estimating solar radiation in seasonally and annual time steps. For this purpose, in validation stage the combination of statistical equations and linear correlation was used, and then the value of mean square deviation (MSD was calculated to evaluate the different models for estimating solar radiation in mentioned time steps. Results and Discussion: The mean values of mean square deviation (MSD of fourteen models for estimating solar radiation were equal to 24.16, 20.42, 4.08 and 16.19 for spring to winter respectively, and 15.40 in annual time step. Therefore, the results showed that using the equations for autumn enjoyed high accuracy, however for other seasons had low accuracy. So, using the equations for annual time step were appropriate more than the equations for seasonally time steps. Also, the mean values of mean square deviation (MSD of the equations based on only sunshine hours, the equations based on only air temperature, and the equations based on the combination of sunshine hours and air temperature for estimating solar radiation were equal to 14.82, 17.40 and 14.88, respectively. Therefore, the results indicated that the models based on only air temperature were the worst conditions for estimating solar radiation in Shiraz region, and therefore, using the sunshine hours for estimating solar radiation is necessary. Conclusions: In this study for estimating solar radiation in seasonally and annual time steps in Shiraz region

Coherent radiation from high-current electron beams of linear accelerators and its applications

International Nuclear Information System (INIS)

Okuda, Shuichi; Takanaka, Makoto; Nakamura, Mitsumi; Kato, Ryukou; Takahashi, Toshiharu; Nam, Soon-Kwon; Taniguchi, Ryouichi; Kojima, Takao

2006-01-01

The characteristics of the far-infrared light source using the coherent radiation emitted from a high-energy short electron bunch have been investigated. The coherent radiation has a continuous spectrum in a submillimeter to millimeter wavelength range and the brightness is relatively high. The spectrum of the radiation is determined by the longitudinal form factor of the electron bunch. The operational conditions of a high-current linear accelerator have been optimized using an electron bunch shape monitor. The coherent transition radiation light source has been applied to absorption spectroscopy for liquid water and to an imaging experiment for a leaf of rose

Secondary and multiple primary cancers relating radiation therapy for cancer of the oral region

International Nuclear Information System (INIS)

Horiuchi, Junichi; Shibuya, Hitoshi; Takeda, Masamune; Takagi, Minoru.

1985-01-01

Secondary and multiple primary cancers relating radiation therapy for squamous cell carcinoma (s.c.c.) of the oral region including lip, oral cavity and oropharynx were analyzed. Out of 1,197 patients with s.c.c. treated with radiation during about 30 years from 1955 to 1983 June, 56 patients (4.7 %) were regarded as double or multiple cancer. The multiple cancer (s.c.c.) was observed frequently in the multicentric zone such as hypopharynx, esophagus and bronchus as well as in other sites of the oral cavity; 67.7 % (42 out of 62 sites). Frequency of synchronous double cancers was increased in recent ten years; 47.1 % (16/34). Careful examination to the above mentioned multicentric zone leads to early detection of secondary cancer and could be expected cure of the disease. Although possibility of radiation-induced cancer could not be ruled out as for 17 patients with late recurrence (more than 8 years), different histologic diagnosis from s.c.c. was obtained in only one (malignant fibrous histiocytoma). Therefore, it was difficult to discriminate radiation-induced cancer from late recurrence in the present study. (author)

The direct radiative effect of wildfire smoke on a severe thunderstorm event in the Baltic Sea region

Science.gov (United States)

Toll, V.; Männik, A.

2015-03-01

On August 8, 2010, a severe derecho type thunderstorm in the Baltic Sea region coincided with smoke from wildfires in Russia. Remarkable smoke aerosol concentrations, with a maximum aerosol optical depth of more than 2 at 550 nm, were observed near the thunderstorm. The impact of the wildfire smoke on the thunderstorm through direct radiative effects was investigated using the Hirlam Aladin Research for Mesoscale Operational Numerical Weather Prediction in Euromed (HARMONIE) model. HARMONIE was successfully able to resolve the dynamics of the thunderstorm, and simulations that considered the influence of the smoke-related aerosols were compared to simulation without aerosols. As simulated by the HARMONIE model, the smoke reduced the shortwave radiation flux at the surface by as much as 300 W/m2 and decreased the near-surface temperature by as much as 3 °C in the vicinity of the thunderstorm and respectively 100 W/m2 and 1 °C in the thunderstorm region. Atmospheric instability decreased through the direct radiative effect of aerosols, and several dynamic features of the simulated thunderstorm appeared slightly weaker.

Radiation safety program in high dose rate brachytherapy facility at INHS Asvini

Directory of Open Access Journals (Sweden)

Kirti Tyagi

2014-01-01

Full Text Available Brachytherapy concerns primarily the use of radioactive sealed sources which are inserted into catheters or applicators and placed directly into tissue either inside or very close to the target volume. The use of radiation in treatment of patients involves both benefits and risks. It has been reported that early radiation workers had developed radiation induced cancers. These incidents lead to continuous work for the improvement of radiation safety of patients and personnel The use of remote afterloading equipment has been developed to improve radiation safety in the delivery of treatment in brachytherapy. The widespread adoption of high dose rate brachytherapy needs appropriate quality assurance measures to minimize the risks to both patients and medical staff. The radiation safety program covers five major aspects: quality control, quality assurance, radiation monitoring, preventive maintenance, administrative measures and quality audit. This paper will discuss the radiation safety program developedfor a high dose rate brachytherapy facility at our centre which may serve as a guideline for other centres intending to install a similar facility.

The enerMENA meteorological network - Solar radiation measurements in the MENA region

Science.gov (United States)

Schüler, D.; Wilbert, S.; Geuder, N.; Affolter, R.; Wolfertstetter, F.; Prahl, C.; Röger, M.; Schroedter-Homscheidt, M.; Abdellatif, G.; Guizani, A. Allah; Balghouthi, M.; Khalil, A.; Mezrhab, A.; Al-Salaymeh, A.; Yassaa, N.; Chellali, F.; Draou, D.; Blanc, P.; Dubranna, J.; Sabry, O. M. K.

2016-05-01

For solar resource assessment of solar power plants and adjustment of satellite data, high accuracy measurement data of irradiance and ancillary meteorological data is needed. For the MENA region (Middle East and Northern Africa), which is of high importance for concentrating solar power applications, so far merely 2 publicly available ground measurement stations existed (BSRN network). This gap has been filled by ten stations in Morocco, Algeria, Tunisia, Egypt and Jordan. In this publication the data quality is analyzed by evaluating data completeness and the cleanliness of irradiance sensors in comparison for all of the stations. The pyrheliometers have an average cleanliness of 99.2 % for week-daily cleaning. This is a 5 times higher effort than for Rotating Shadowband Irradiometer (RSI) stations which even have a slightly higher average cleanliness of 99.3 % for weekly cleaning. Furthermore, RSI stations show a data completeness of 99.4 % compared to 93.6 % at the stations equipped with thermal sensors. The results of this analysis are used to derive conclusions concerning instrument choice and are hence also applicable to other solar radiation measurements outside the enerMENA network. It turns out that RSIs are the more reliable and robust choice in cases of high soiling, rare station visits for cleaning and maintenance, as usual in desert sites. Furthermore, annual direct normal and global horizontal irradiation as well as average meteorological parameters are calculated for all of the stations.

Radiation transport benchmarks for simple geometries with void regions using the spherical harmonics method

International Nuclear Information System (INIS)

Kobayashi, K.

2009-01-01

In 2001, an international cooperation on the 3D radiation transport benchmarks for simple geometries with void region was performed under the leadership of E. Sartori of OECD/NEA. There were contributions from eight institutions, where 6 contributions were by the discrete ordinate method and only two were by the spherical harmonics method. The 3D spherical harmonics program FFT3 by the finite Fourier transformation method has been improved for this presentation, and benchmark solutions for the 2D and 3D simple geometries with void region by the FFT2 and FFT3 are given showing fairly good accuracy. (authors)

Attribution of aerosol radiative forcing over India during the winter monsoon to emissions from source categories and geographical regions

Science.gov (United States)

Verma, S.; Venkataraman, C.; Boucher, O.

2011-08-01

We examine the aerosol radiative effects due to aerosols emitted from different emission sectors (anthropogenic and natural) and originating from different geographical regions within and outside India during the northeast (NE) Indian winter monsoon (January-March). These studies are carried out through aerosol transport simulations in the general circulation (GCM) model of the Laboratoire de Météorologie Dynamique (LMD). The model estimates of aerosol single scattering albedo (SSA) show lower values (0.86-0.92) over the region north to 10°N comprising of the Indian subcontinent, Bay of Bengal, and parts of the Arabian Sea compared to the region south to 10°N where the estimated SSA values lie in the range 0.94-0.98. The model estimated SSA is consistent with the SSA values inferred through measurements on various platforms. Aerosols of anthropogenic origin reduce the incoming solar radiation at the surface by a factor of 10-20 times the reduction due to natural aerosols. At the top-of-atmosphere (TOA), aerosols from biofuel use cause positive forcing compared to the negative forcing from fossil fuel and natural sources in correspondence with the distribution of SSA which is estimated to be the lowest (0.7-0.78) from biofuel combustion emissions. Aerosols originating from India and Africa-west Asia lead to the reduction in surface radiation (-3 to -8 W m -2) by 40-60% of the total reduction in surface radiation due to all aerosols over the Indian subcontinent and adjoining ocean. Aerosols originating from India and Africa-west Asia also lead to positive radiative effects at TOA over the Arabian Sea, central India (CNI), with the highest positive radiative effects over the Bay of Bengal and cause either negative or positive effects over the Indo-Gangetic plain (IGP).

Effects of chronic low level radiation in the population residing in the high level natural radiation area in Kerala, India: employing heritable DNA mutation studies.

Science.gov (United States)

Ahmad, Shazia; Koya, P K M; Seshadri, M

2013-03-18

To study the effect of chronic low level radiation, 4040 meiosis were screened at eight microsatellite and five minisatellite (2485 and 1555 meiosis respectively) marker loci in people residing in high and normal level natural radiation areas of Kerala. Variants in the repeat length of allele were considered as mutants. Mutation rates (expressed as the number of mutations observed in the total number of meiosis) were 6.4×10(-3) (16/2485) and 2.6×10(-3) (4/1555) at microsatellite and minisatellite respectively. The germline microsatellite mutation frequency of father was 1.78 times higher at 7.52×10(-3) (8/1064) compared to 4.22×10(-3) (6/1421) of mother (P=0.292, Fisher's Exact two-sided test). The paternal and maternal mutation rates at minisatellite loci were more or less similar at 2.78×10(-3) (2/719) and 2.39×10(-3) (2/836), respectively (P=1.0, Fisher's Exact two-sided test). Higher but statistically non-significant microsatellite mutation frequency was observed in HLNRA compared to NLNRA (7.25×10(-3) vs 3.64×10(-3); P=0.547). The apparent increase in the mutation rate of microsatellite loci with the increase in radiation dose was also not statistically significant. All the four minisatellite mutation observed were from HLNRA (1198 meiosis) and no mutation was observed among 357 meiosis screened from NLNRA families. All the markers used in the present study were in the non-coding region and hence mutations in these regions may not cause adverse health effects, but the study is important in understanding the effect of chronic low level radiation. Copyright © 2012 Elsevier B.V. All rights reserved.

Late effects of radiation therapy in the head and neck region

International Nuclear Information System (INIS)

Cooper, Jay S.; Fu, Karen; Marks, James; Silverman, Sol

1995-01-01

The head and neck region is composed of numerous structures, each with an inherent response to radiation that is largely governed by the presence or absence of mucosa, salivary glands, or specialized organs within that site. Irradiated mucocutaneous tissues demonstrate increased vascular permeability that leads to fibrin deposition, subsequent collagen formation, and eventual fibrosis. Irradiated salivary tissue degenerates after relatively small doses, leading to markedly diminished salivary output. This, in turn, effects the teeth by promoting dental decay which, in turn, effects the integrity of the mandible. Details of these changes are presented, including their pathophysiology, clinical syndromes, and potential treatment

High reliability EPI-base radiation hardened power transistor

International Nuclear Information System (INIS)

Clark, L.E.; Saltich, J.L.

1978-01-01

A high-voltage power transistor is described which is able to withstand fluences as high as 3 x 10 14 neutrons per square centimeter and still be able to operate satisfactorily. The collector may be made essentially half as thick and twice as heavily doped as normally and its base is made in two regions which together are essentially four times as thick as the normal power transistor base region. The base region has a heavily doped upper region and a lower region intermediate the upper heavily doped region and the collector. The doping in the intermediate region is as close to intrinsic as possible, in any event less than about 3 x 10 15 impurities per cubic centimeter. The second base region has small width in comparison to the first base region, the ratio of the first to the second being at least about 5 to 1. The base region having the upper heavily doped region and the intermediate or lower low doped region contributes to the higher breakdown voltage which the transistor is able to withstand. The high doping of the collector region essentially lowers that portion of the breakdown voltage achieved by the collector region. Accordingly, it is necessary to transfer certain of this breakdown capability to the base region and this is achieved by using the upper region of heavily doped and an intermediate or lower region of low doping