WorldWideScience

Sample records for emitted radiation characteristics

  1. Tunable radiation emitting semiconductor device

    NARCIS (Netherlands)

    2009-01-01

    A tunable radiation emitting semiconductor device includes at least one elongated structure at least partially fabricated from one or more semiconductor materials exhibiting a bandgap characteristic including one or more energy transitions whose energies correspond to photon energies of light

  2. Radiation emitting devices act

    International Nuclear Information System (INIS)

    1970-01-01

    This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws

  3. Radiation emitting devices regulations

    International Nuclear Information System (INIS)

    1970-01-01

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  4. Radiation Emitting Product Corrective Actions and Recalls

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database provides descriptions of radiation-emitting products that have been recalled under an approved corrective action plan to remove defective and...

  5. Radiation-emitting Electronic Product Codes

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database contains product names and associated information developed by the Center for all products, both medical and non-medical, which emit radiation. It...

  6. CASPER: Concordia Atmospheric SPectroscopy of Emitted Radiation

    Science.gov (United States)

    de Petris, M.; Catalano, A.; de Gregori, S.; Lamagna, L.; Lattanzi, V.; Luzzi, G.; Maoli, R.; Melchiorri, A.; Melchiorri, F.; Savini, G.; Vetrani, G. G.; Battistelli, E. S.; Valenziano, L.; Mandolesi, N.; Villa, F.; Cuttaia, F.; Ade, P. A. R.; Mauskopf, P.; Orlando, A.; Encrenaz, P.; Pardo, J. R.; Cernicharo, J.

    CASPER (Concordia Atmospheric SPectroscopy of Emitted Radiation) is a spectrometer proposed for installation at Dome C, devoted to measurements of atmospheric emission in the spectral region between 180 μm and 3 mm (3 55 cm-1). This instrument will be able to perform continuous spectral sampling at different altitudes at angular scales of 1°. From the recorded data it is possible to extract atmospheric transmittance within 1% in the whole wide operating band, together with water vapour content and O{2} and O{3} concentrations. CASPER will allow us to characterize the site for future FIR/mm telescopes. Atmospheric data recorded by CASPER will allow for correction of astrophysical and cosmological observations without the need for telescope-specific procedures and further loss of observation time with more precision in the observations themselves. Calibration of ground-based telescopes on known sky sources is strongly affected by atmospheric absorption. CASPER has this as its primary goal. The spectrometer is based on a Martin-Puplett interferometer. Two data sampling solutions will be performed: phase modulation & fast scan strategy. Sky radiation is collected towards the interferometer by an optical setup that allows the field of view, to explore the full 0° div 90° range of elevation angles. With a low spurious polarization instrument, monitoring of polarized atmospheric contribution will be possible.

  7. Coherence characteristics of light-emitting diodes

    International Nuclear Information System (INIS)

    Mehta, Dalip Singh; Saxena, Kanchan; Dubey, Satish Kumar; Shakher, Chandra

    2010-01-01

    We report the measurement of coherence characteristics of light-emitting diodes (LEDs). Experiments were performed using red and green color LEDs directly illuminating the Young's double slit kept in the far-zone. Fourier transform fringe analysis technique was used for the measurement of the visibility of interference fringes from which the modulus of degree of spectral coherence was determined. Low degree of spectral coherence, typically 0.4 for red and 0.2 for green LED with double-slit separation of 400 μm was observed. A variable slit was then kept in front of the LEDs and the double slit was illuminated with the light coming out of the slit. Experiments were performed with various slit sizes and the visibility of the interference fringes was observed. It was found that visibility of the interference fringes changes drastically in presence of variable slit kept in front of LEDs and a high degree of spectral coherence, typically 0.85 for red and 0.8 for green LED with double-slit separation of 400 μm and rectangular slit opening of 500 μm was observed. The experimental results are compared with the theoretical counterparts. Coherence lengths of both the LEDs were also determined and it was obtained 5.8±2 and 24±4 μm for green and red LEDs, respectively.

  8. Radiative flux emitted by a burning PMMA slab

    International Nuclear Information System (INIS)

    Parent, G; Acem, Z; Collin, A; Berfroi, R; Boulet, P; Pizzo, Y; Mindykowski, P; Kaiss, A; Porterie, B

    2012-01-01

    The degradation of a PMMA sample has been studied based on experimental results obtained for the radiation emission by a burning slab. Observations of the infrared emission perpendicular to the plate, in the range where the optically thin flame is weakly emitting, indicate a plate temperature close to 680 K which is an indication on the surface temperature during the degradation process. Observations from the side allow a flame characterization without the plate emission superimposition. This is a promising way for evaluating data regarding the flame characteristics: temperature, gaz concentration and soot volumetric fraction.

  9. Can a tachyon emit light radiation in all directions

    Energy Technology Data Exchange (ETDEWEB)

    Ramanujam, G A [NGM Coll., Tamil Nadu (India). Dept. of Physics

    1976-03-01

    It is shown here that a critical analysis of the approaches employed by various authors to accommodate tachyons into special relativity leads one to the conclusion that a tachyon can emit light radiation only along its line of motion.

  10. SOR/72-43 Radiation Emitting Devices Regulations

    International Nuclear Information System (INIS)

    1972-01-01

    These Regulations of 10 February 1972, supplemented by SOR/77-895, lay down the classes of radiation emitting devices for the purposes of the Radiation Emitting Devices Act. They lay down their standards of design and construction and warning sign specifications and provide for the procedure to be followed by inspectors of such devices. The devices include inter alia extra-oral dental x-ray equipment, baggage inspection x-ray devices, laser scanners, television receivers. (NEA)

  11. An assessment of ultraviolet radiation components of light emitted ...

    African Journals Online (AJOL)

    An assessment of ultraviolet radiation components of light emitted from electric arc and their possible exposure risks. ... The study of Ultraviolet Radiation has of recent become interesting because of the health hazards it poses to human. Apart from its intensity reaching the earth from the sun, other man-made sources have ...

  12. Characteristics of synchrotron radiation

    International Nuclear Information System (INIS)

    Brown, G.S.

    1984-01-01

    The characteristics and production of synchrotron radiation are qualitatively discussed. The spectral properties of wigglers and undulators are briefly described. Possible applications in condensed matter physics are outlined. These include atomic and molecular studies, crystallography, impurities in solids and radiographic imaging

  13. Null bactericidal effect of ultraviolet radiation emitted by LEDs.

    Directory of Open Access Journals (Sweden)

    Francisco Alcántara Muñoz

    2016-11-01

    Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

  14. Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

    International Nuclear Information System (INIS)

    De Marco, M; Maggi, S

    2006-01-01

    Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m -1 (E-field 400 V m -1 ). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy

  15. Quantum dot superluminescent light emitting diodes: Ideal blackbody radiators?

    Energy Technology Data Exchange (ETDEWEB)

    Blazek, Martin; Elsaesser, Wolfgang [Institute of Applied Physics, Darmstadt University of Technology (Germany); Hopkinson, Mark [Dept. E and E.E, University of Sheffield (United Kingdom); Krakowski, Michel [Alcatel Thales, III-V Lab. (France)

    2008-07-01

    Quantum dot (QD) superluminescent light emitting diodes (SLEDs) provide large optical bandwidths at desired wavelengths and are therefore promising devices for incoherent light application. The intensity noise behavior of QD SLEDs is of fundamental physical interest as it provides insight into the photon emission process. We performed high precision intensity noise measurements over several decades of optical output power. For low driving currents spontaneous emission leads to Shot Noise. For high currents we find excess noise behavior with Amplified Spontaneous Emission acting as the dominant source of noise. The QD SLEDs' noise can be described as blackbody radiation noise with a limited number of optical modes. It is therefore possible to identify the SLEDs' relevant intensity noise parameters.

  16. Continuum radiation emitted from transition metals under ion bombardment

    International Nuclear Information System (INIS)

    El Boujlaidi, A.; Kaddouri, A.; Ait El Fqih, M.; Hammoum, K.; Aouchiche, H.

    2012-01-01

    Optical emission of transition metals has been studied during 5 keV Kr + ions bombardment within and without oxygen atmosphere in the colliding chamber. The observed spectra consist of a series of discrete lines superimposed on a broad continuum. Generally, the emission intensity was influenced by the presence of oxygen giving rise to transient effects as well as to an increase in the line intensity. The behaviours of spectral lines were successfully explained in term of electron-transfer process between the excited sputtered atom and the solid surface. In this work, we have focused our study on the continuous radiation emitted during ion bombardment. The experimental results suggest that the continuum emission depends on the nature of metal and very probably related to its electronic structure. The collective deactivation of 3d-shell electrons appears to play a role in the emission of this radiation. The observed enhancement in the presence of oxygen is probably due to a significant contribution of the oxide molecules. (authors)

  17. Bill C-5, an act to amend the radiation emitting devices act

    International Nuclear Information System (INIS)

    1984-01-01

    This Act, entitled Bill C-5, allows for a series of amendments to the Radiation Emitting Devices Act. The amendments relate to regulations concerned with the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of radiation emitting devices

  18. White top emitting OLED with angle independent emission characteristic

    Energy Technology Data Exchange (ETDEWEB)

    Thomschke, Michael; Freitag, Patricia; Schwartz, Gregor; Nitsche, Robert; Walzer, Karsten; Leo, Karl [Technische Universitaet Dresden, Institut fuer Angewandte Photophysik, Georg-Baehr-Strasse 1, 01062 Dresden (Germany)

    2008-07-01

    The general device structure of a top emitting organic light emitting diode (OLED) consists of several organic layers sandwiched in between two metal contacts, with the top one being semitransparent for light outcoupling reasons. Due to the high reflectivity of the electrodes, strong microcavity effects occur which lead to a preferred emission of light of a certain wavelength with main outcoupling in forward direction. This creates rather narrow emission bands, accompanied by strong spectral shifts upon viewing angle variation. By using an organic capping layer on top of the semitransparent metal contact, this unwanted effect can be reduced. This is important especially for white light emission for the use of OLEDs in future lighting applications. Our optical simulations show that the strong angular dependence of the emission color almost vanishes. To verify the simulations we study white top emitting OLEDs based on an approach which are adapted to the top emitting case.

  19. Radiation characteristics of helical tomotherapy

    International Nuclear Information System (INIS)

    Jeraj, Robert; Mackie, Thomas R.; Balog, John; Olivera, Gustavo; Pearson, Dave; Kapatoes, Jeff; Ruchala, Ken; Reckwerdt, Paul

    2004-01-01

    Helical tomotherapy is a dedicated intensity modulated radiation therapy (IMRT) system with on-board imaging capability (MVCT) and therefore differs from conventional treatment units. Different design goals resulted in some distinctive radiation field characteristics. The most significant differences in the design are the lack of flattening filter, increased shielding of the collimators, treatment and imaging operation modes and narrow fan beam delivery. Radiation characteristics of the helical tomotherapy system, sensitivity studies of various incident electron beam parameters and radiation safety analyses are presented here. It was determined that the photon beam energy spectrum of helical tomotherapy is similar to that of more conventional radiation treatment units. The two operational modes of the system result in different nominal energies of the incident electron beam with approximately 6 MeV and 3.5 MeV in the treatment and imaging modes, respectively. The off-axis mean energy dependence is much lower than in conventional radiotherapy units with less than 5% variation across the field, which is the consequence of the absent flattening filter. For the same reason the transverse profile exhibits the characteristic conical shape resulting in a 2-fold increase of the beam intensity in the center. The radiation leakage outside the field was found to be negligible at less than 0.05% because of the increased shielding of the collimators. At this level the in-field scattering is a dominant source of the radiation outside the field and thus a narrow field treatment does not result in the increased leakage. The sensitivity studies showed increased sensitivity on the incident electron position because of the narrow fan beam delivery and high sensitivity on the incident electron energy, as common to other treatment systems. All in all, it was determined that helical tomotherapy is a system with some unique radiation characteristics, which have been to a large extent

  20. Development of long-wavelength-emitting scintillators with improved decay time characteristics

    International Nuclear Information System (INIS)

    Franks, L.A.; Lutz, S.; Lyons, P.B.

    1978-01-01

    Progress is reported from efforts to develop radiation-to-light converters suitable for use with optical fibers as they are applied to the diagnostics of transient nuclear phenomena. Liquid and plastic fluors have been prepared which emit in the 550- to 600-nm region. Ternary liquid systems with decay times as short as 1.3 ns at 560 nm and plastic fluors with decay times less than 3 ns at 560 nm are reported. Other liquid and plastic fluors are reported with improved emission characteristics in the region of 600 nm. Conversion efficiences, on a pulse amplitude basis, are generally lower than that of a commercially available 570 nm-16 ns plastic fluor

  1. Estimating the Infrared Radiation Wavelength Emitted by a Remote Control Device Using a Digital Camera

    Science.gov (United States)

    Catelli, Francisco; Giovannini, Odilon; Bolzan, Vicente Dall Agnol

    2011-01-01

    The interference fringes produced by a diffraction grating illuminated with radiation from a TV remote control and a red laser beam are, simultaneously, captured by a digital camera. Based on an image with two interference patterns, an estimate of the infrared radiation wavelength emitted by a TV remote control is made. (Contains 4 figures.)

  2. A Study of the interaction of radiation and semiconductor lasers: an analysis of transient and permanent effects induced on edge emitting and vertical cavity surface emitting laser diodes

    International Nuclear Information System (INIS)

    Pailharey, Eric

    2000-01-01

    The behavior of laser diodes under transient environment is presented in this work. The first section describes the basic phenomena of radiation interaction with matter. The radiative environments, the main characteristics of laser diodes and the research undertaken on the subject are presented and discussed. The tests on 1300 nm edge emitting laser diode are presented in the second section. The response to a transient ionizing excitation is explored using a 532 nm laser beam. The time of return to steady state after the perturbation is decomposed into several steps: decrease of the optical power during excitation, turn-on delay, relaxation oscillations and optical power offset. Their origins are analyzed using the device structure. To include all the phenomena in a numerical simulation of the device, an individual study of low conductivity materials used for the lateral confinement of the current density is undertaken. The effects of a single particle traversing the optical cavity and an analysis of permanent damages induced by neutrons are also determined. In the last section, 850 nm vertical cavity surface emitting laser diodes (VCSEL) are studied. The behavior of these devices which performances are in constant evolution, is investigated as a function of both temperature and polarization. Then VCSEL are submitted to transient ionizing irradiation and their responses are compared to those of edge emitting diodes. When proton implantation is used in the process, we observe the same behavior for both technologies. VCSEL were submitted to neutron fluence and we have studied the influence of the damages on threshold current, emission patterns and maximum of optical power. (author) [fr

  3. Current-voltage characteristics of dendrimer light-emitting diodes

    International Nuclear Information System (INIS)

    Stevenson, S G; Samuel, I D W; Staton, S V; Knights, K A; Burn, P L; Williams, J H T; Walker, Alison B

    2010-01-01

    We have investigated current-voltage (I-V) characteristics of unipolar and bipolar organic diodes that use phosphorescent dendrimers as the emissive organic layer. Through simulation of the measured I-V characteristics we were able to determine the device parameters for each device structure studied, leading to a better understanding of injection and transport behaviour in these devices. It was found that the common practice of assuming injection barriers are equal to the difference between bare electrode work functions and molecular orbital levels is unsuitable for the devices considered here, particularly for gold contacts. The studies confirm that different aromatic units in the dendrons can give significant differences in the charge transporting properties of the dendrimers.

  4. Current-voltage characteristics of dendrimer light-emitting diodes

    Science.gov (United States)

    Stevenson, S. G.; Samuel, I. D. W.; Staton, S. V.; Knights, K. A.; Burn, P. L.; Williams, J. H. T.; Walker, Alison B.

    2010-09-01

    We have investigated current-voltage (I-V) characteristics of unipolar and bipolar organic diodes that use phosphorescent dendrimers as the emissive organic layer. Through simulation of the measured I-V characteristics we were able to determine the device parameters for each device structure studied, leading to a better understanding of injection and transport behaviour in these devices. It was found that the common practice of assuming injection barriers are equal to the difference between bare electrode work functions and molecular orbital levels is unsuitable for the devices considered here, particularly for gold contacts. The studies confirm that different aromatic units in the dendrons can give significant differences in the charge transporting properties of the dendrimers.

  5. Current-voltage characteristics of dendrimer light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, S G; Samuel, I D W [Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9SS (United Kingdom); Staton, S V; Knights, K A; Burn, P L [Department of Chemistry, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA (United Kingdom); Williams, J H T; Walker, Alison B, E-mail: a.b.walker@bath.ac.u [Department of Physics, University of Bath, Bath, BA2 7AY (United Kingdom)

    2010-09-29

    We have investigated current-voltage (I-V) characteristics of unipolar and bipolar organic diodes that use phosphorescent dendrimers as the emissive organic layer. Through simulation of the measured I-V characteristics we were able to determine the device parameters for each device structure studied, leading to a better understanding of injection and transport behaviour in these devices. It was found that the common practice of assuming injection barriers are equal to the difference between bare electrode work functions and molecular orbital levels is unsuitable for the devices considered here, particularly for gold contacts. The studies confirm that different aromatic units in the dendrons can give significant differences in the charge transporting properties of the dendrimers.

  6. an assessment of ultraviolet radiation components of light emitted ...

    African Journals Online (AJOL)

    Dr

    therefore high for exposure limits of 8 hours for UV-B and UV-C and the 16 minutes for UV-A. The investigation ... has become particularly interesting as the ozone layer ... THEORY. Ultraviolet (UV) light is an electromagnetic radiation with a ...

  7. Measurements of nonionizing radiation emitted from microwave oven

    International Nuclear Information System (INIS)

    Elnour, Yassir Elnour Osman

    2014-05-01

    There is an increase in the usage of microwave oven which is used electromagnetic radiation in the microwave range, which believed to be harmful to human health. The measurements were taken at distance of range(0-100) cm from the microwave oven. The study concluded that the risk possibility of the radiation increases at high mode. We measured the power density, magnetic field and signal strength of microwave oven using the SPECTRAN high frequency (HF-6080) detector. The experimental results of power density were found to be (3.78-208000) nW/m 2 and magnetic field is (0.001-0.744) mA/m. These values are less than the exposure limits recommended. (author)

  8. Non-radiative recombination losses in polymer light-emitting diodes

    NARCIS (Netherlands)

    Kuik, M.; Koster, L. J. A.; Dijkstra, A. G.; Wetzelaer, G. A. H.; Blom, P. W. M.

    We present a quantitative analysis of the loss of electroluminescence in light-emitting diodes (LEDs) based on poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) due to the combination of non-radiative trap-assisted recombination and exciton quenching at the metallic cathode. It is

  9. Peculiarities of electrooptical characteristics of gallium phosphide light-emitting diodes in high injection level conditions

    Directory of Open Access Journals (Sweden)

    O. M. Hontaruk

    2015-04-01

    Full Text Available Electroluminescence of green N-doped gallium phosphide light-emitting diodes was studied. The negative differential resistance region in the current-voltage characteristics was found at low temperature (Т ≤ 90 К. Possible reason of this phenomenon is the redistribution of recombinational flows between annihilation channels on isolated nitrogen atoms and annihilation channel on the NN1 pairs.

  10. Geometric radiation exchange factors for axial radiative transfer in an LWR core filled with absorbing-emitting gases

    International Nuclear Information System (INIS)

    Chan, S.H.; Cho, D.H.

    1984-01-01

    A reactor core filled with an emitting-absorbing mixture (like steam, hydrogen gas and fission gases) is considered. Analysis is provided to evaluate axial radiative heat exchange of a rod bundle with a nonuniform axial temperature distribution. The necessary radiation exchange shape factors (geometric mean absorptance, emittance and transmittance) between segments of the complex rod bundle arrangement are presented. They are applicable to arbitrary sizes of segments, well suited for numerical computations

  11. Optical radiation emitted by a silver surface bombarded by low-energy electrons

    International Nuclear Information System (INIS)

    Miserey, F.; Lebon, P.; Septier, A.; Trehin, F.; Beaugrand, C.

    1975-01-01

    Thick silver targets are obtained on flat glass discs by evaporation in a UHV cell (p -10 torr) and their optical coefficients measured by ellipsometry. A field-emission electron gun bombards a limited region of the target, corresponding to the entry pupil of a light spectrometer. Radiation emitted in the domain 250-600nm is analyzed for both normal and parallel polarizations. Spectral distributions of photons are obtained by using a very sensitive counting device including a multi channel analyzer. First experimental results concerning optical radiation generated by 6keV electrons are reported and compared to Transition Radiation and Bremsstrahlung theoretical spectra [fr

  12. Characteristics of organic light emitting diodes with copper iodide as injection layer

    Energy Technology Data Exchange (ETDEWEB)

    Stakhira, P., E-mail: stakhira@polynet.lviv.u [Lviv Polytechnic National University, S. Bandera, 12, Lviv, 79013 (Ukraine); Cherpak, V.; Volynyuk, D.; Ivastchyshyn, F. [Lviv Polytechnic National University, S. Bandera, 12, Lviv, 79013 (Ukraine); Hotra, Z. [Lviv Polytechnic National University, S. Bandera, 12, Lviv, 79013 (Ukraine); Rzeszow University of Technology, W. Pola 2, Rzeszow, 35-959 (Poland); Tataryn, V. [Lviv Polytechnic National University, S. Bandera, 12, Lviv, 79013 (Ukraine); Luka, G. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

    2010-09-30

    We have studied the use of a thin copper iodide (CuI) film as an efficient injection layer of holes from indium tin oxide (ITO) anode in a light-emitting diode structure based on tris-8-hydroxyquinoline aluminium (Alq3). The results of impedance analysis of two types of diode structures, ITO/CuI/Alq3/poly(ethylene glycol) dimethyl ether/Al and ITO/Alq3/poly(ethylene glycol) dimethyl ether/Al, are presented. Comparative analysis of their current density-voltage, luminance-voltage and impedance characteristics shows that presence of CuI layer facilitates injection of holes from ITO anode into the light-emitting layer Alq3 and increases electroluminescence efficiency of the organic light emitting diodes.

  13. Neutron emission from 9Be nucleus under the action of β+ and γ radiation emitted in radioactive decay

    International Nuclear Information System (INIS)

    Vo Dak Bang; Gangrskij, Yu.P.; Miller, M.B.; Mikhajlov, L.V.; Fam Zui Khien; Kharisov, I.F.

    1980-01-01

    The neutron yield from the 9 Be nucleus under the action of beta and gamma-radiation emitted at the radiative decay of 11 C, 62 Cu, 66 Ga, 74 Br isotopes is measured. These isotopes differ essentially by the emitted radiation spectra. The contribution of various processes ((γ, n)-reactions, inelastic scattering and positron nonradiative annihilation) to the neutron yield observed is determined [ru

  14. Correlation of electromagnetic radiation emitted from coal or rock to supporting resistance

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Hui-lin; Wang, En-yuan; Song, Xiao-yan; Zhang, Hong-jie; Li, Zhong-hui [China University of Mining & Technology, Xuzhou (China). School of Safety Engineering

    2009-05-15

    More accurate forecasting of rock burst might be possible from observations of electromagnetic radiation emitted in the mine. We analyzed experimental observations and field data from the Muchengjian coal mine to study the relationship between electromagnetic radiation signal intensity and stress during the fracturing of coal, or rock, and samples under load. The results show that the signal intensity is positively correlated with stress. In addition, we investigated the change in the electromagnetic radiation intensity, the supporting resistance in a real coal mine environment, and the coal or rock stress in the mining area. The data analysis indicates that: (1) electromagnetic radiation intensity can accurately reflect the distribution of stress in the mining area; and, (2) there is a correlation between electromagnetic radiation intensity and supporting resistance. The research has some practical guiding significance for rock burst forecasting and for the prevention of accidents in coal mines. 9 refs., 6 figs.

  15. Synchrotron radiation: its characteristics and applications

    International Nuclear Information System (INIS)

    Blewett, J.P.; Chasman, R.; Green, G.K.

    1977-01-01

    It has been known for a century that charged particles radiate when accelerated and that relativistic electrons in the energy range between 100 MeV and several GeV and constrained to travel in circular orbits emit concentrated, intense beams with broad continuous spectra that can cover the electromagnetic spectrum from infrared through hard X-rays. Recently the possible applications of this radiation have been appreciated and electron synchrotrons and electron storage rings are now being used in many centers for studies of the properties of matter in the solid, liquid and gaseous states. A brief history is presented of ''synchrotron radiation'' as it is now called. The basic properties of this radiation are described and the world-wide distribution is indicated of facilities for its production. Particular attention is given to the proposed facility at Brookhaven which will be the first major installation to be dedicated only to the production and use of synchrotron radiation. Finally, typical examples are given of applications in the areas of radiation absorption studies, techniques based on scattering of radiation, and advances based on X-ray lithography

  16. The clinical characteristics of the radiation pneumonia

    International Nuclear Information System (INIS)

    Zhang Fuzheng; Wang Mingzhi; Chen Jianjiang; Wang Zhongxiang; Mao Yongjie

    2000-01-01

    Objective: To analyse the clinical characteristics of the radiation pneumonia, sum the experience and the basis of the radiation pneumonia for its prevention and treatment. Method: Twenty three cases with radiation pneumonia from 1991 to 1998 were retrospectively analysed. Its clinical manifestation, chest X-ray, thoracic CT and blood routine were evaluated. Result: The acute manifestation was fever, cough, dyspnea, and the chronic manifestation was cough and insufficiency of pulmonary function. Conclusion: The prevention of radiation pneumonia is more important, high dose cortical steroids and antibiotics were prescribed during the acute stage and the chronic radiation pneumonia is irreversible

  17. Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors

    Science.gov (United States)

    Mortazavi, SMJ; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, AR

    2014-01-01

    Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors. PMID:25505778

  18. Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors

    Directory of Open Access Journals (Sweden)

    SMJ Mortazavi

    2014-09-01

    Full Text Available Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students, blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2 while the phone was ringing. For Control- Repeat group (15 students, two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (ΔC in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test. To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors.

  19. Clinical characteristics of subacute radiation sickness

    International Nuclear Information System (INIS)

    Jiang Benrong; Ye Genyao; Huang Shimin

    1991-01-01

    The clinical characteristics, diagnosis and differential diagnosis of subacute radiation sickness are analysed and discussed in this paper on the basis of clinical data from cases in a 137 Cs source accident in Mudanjiang and of a review of the literature. We consider that the subacute radiation sickness is a whole body disease caused by comparatively large dose of continuous or intermittent external irradiation in several weeks or months. it must be differentiated from acute radiation sickness, chronic radiation sickness, idiopathic aplastic anemia and other hematological diseases, such as paroxysmal nocturnal hemoglobinuria, acute leukemia and myelodysplastic syndrome

  20. Calculating the radiation characteristics of accelerated electrons in laser-plasma interactions

    International Nuclear Information System (INIS)

    Li, X. F.; Yu, Q.; Qu, J. F.; Kong, Q.; Gu, Y. J.; Ma, Y. Y.; Kawata, S.

    2016-01-01

    In this paper, we studied the characteristics of radiation emitted by electrons accelerated in a laser–plasma interaction by using the Lienard–Wiechert field. In the interaction of a laser pulse with a underdense plasma, electrons are accelerated by two mechanisms: direct laser acceleration (DLA) and laser wakefield acceleration (LWFA). At the beginning of the process, the DLA electrons emit most of the radiation, and the DLA electrons emit a much higher peak photon energy than the LWFA electrons. As the laser–plasma interaction progresses, the LWFA electrons become the major radiation emitter; however, even at this stage, the contribution from DLA electrons is significant, especially to the peak photon energy.

  1. Spectral-Modulation Characteristics of Vertical-Cavity Surface-Emitting Lasers

    Science.gov (United States)

    Vas'kovskaya, M. I.; Vasil'ev, V. V.; Zibrov, S. A.; Yakovlev, V. P.; Velichanskii, V. L.

    2018-01-01

    The requirements imposed on vertical-cavity surface-emitting lasers in a number of metrological problems in which optical pumping of alkali atoms is used are considered. For lasers produced by different manufacturers, these requirements are compared with the experimentally observed spectral characteristics at a constant pump current and in the microwave modulation mode. It is shown that a comparatively small number of lasers in the microwave modulation mode make it possible to obtain the spectrum required for atomic clocks based on the coherent population-trapping effect.

  2. Effects of radiation emitted from visual display terminals on the oral health status

    International Nuclear Information System (INIS)

    Kazem, H.H.

    2008-01-01

    This study was designed to investigate the effects of exposure to radiation emitted from visual display terminals (VDTs) on the oral health status; a cross sectional study was carried out on 100 participants both males and females with age ranging between 22- 40 years working in various places in Cairo. They were divided into two groups; the first consists of 50 subjects working in front of VDTs eight hours min. daily, min. 5 days/ week, 2 years or more, and the other group 50 subjects working away from any VDTs. Both groups were subjected to both oral and dental examinations, including soft tissues assessment by using gingival index (GI) and hard tissues assessment by using decayed, missed, filled (DMF) index. Saliva analysis was done including ph analysis by ph meter cyberscan 500 and trace elements analysis by ion chromatography and salivary immunoglobulin A (sIgA) analysis by ELISA, body temperature by using digital thermometer. The values were compared between both groups and also between before and after exposure in the exposed group. The results demonstrated that the difference in the mean values of either GI or DMF or ph or anions and cations or sIgA levels between exposed and non exposed groups or even between before and after exposure in the exposed group was found to be statistically insignificant. On the other hand there were significant changes in the mean values of body temperature between exposed and non-exposed group and also between before and after exposure in the exposed group. Accordingly, within the limits of this study we can conclude that radiation emitted from VDTs affects body temperature, but do not have any effect on oral health including; hard or soft tissues or salivary components. This might be explained by the radiation with very low energy emitted from VDTs

  3. Effects of radiation emitted from visual display terminals on the oral health status

    Energy Technology Data Exchange (ETDEWEB)

    Kazem, H H [National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

    2008-07-01

    This study was designed to investigate the effects of exposure to radiation emitted from visual display terminals (VDTs) on the oral health status; a cross sectional study was carried out on 100 participants both males and females with age ranging between 22- 40 years working in various places in Cairo. They were divided into two groups; the first consists of 50 subjects working in front of VDTs eight hours min. daily, min. 5 days/ week, 2 years or more, and the other group 50 subjects working away from any VDTs. Both groups were subjected to both oral and dental examinations, including soft tissues assessment by using gingival index (GI) and hard tissues assessment by using decayed, missed, filled (DMF) index. Saliva analysis was done including ph analysis by ph meter cyberscan 500 and trace elements analysis by ion chromatography and salivary immunoglobulin A (sIgA) analysis by ELISA, body temperature by using digital thermometer. The values were compared between both groups and also between before and after exposure in the exposed group. The results demonstrated that the difference in the mean values of either GI or DMF or ph or anions and cations or sIgA levels between exposed and non exposed groups or even between before and after exposure in the exposed group was found to be statistically insignificant. On the other hand there were significant changes in the mean values of body temperature between exposed and non-exposed group and also between before and after exposure in the exposed group. Accordingly, within the limits of this study we can conclude that radiation emitted from VDTs affects body temperature, but do not have any effect on oral health including; hard or soft tissues or salivary components. This might be explained by the radiation with very low energy emitted from VDTs.

  4. Some characteristics and effects of natural radiation

    International Nuclear Information System (INIS)

    Mc Laughlin, J.P.

    2015-01-01

    Since life first appeared on the Earth, it has, in all its subsequent evolved forms including human, been exposed to natural radiation in the environment both from terrestrial and extra-terrestrial sources. Being an environmental mutagen, ionising natural radiation may have played a role of some significance in the evolution of early life forms on Earth. It has been estimated by United Nations Scientific Committee on the Effects of Atomic Radiation that at the present time, exposure to natural radiation globally results in an annual average individual effective dose of about 2.4 mSv. This represents about 80 % of the total dose from all sources. The three most important components of natural radiation exposure are cosmic radiation, terrestrial radioactivity and indoor radon. Each of these components exhibits both geographical and temporal variabilities with indoor radon exposure being the most variable and also the largest contributor to dose for most people. In this account, an overview is given of the characteristics of the main components of the natural radiation environment and some of their effects on humans. In the case of cosmic radiation, these range from radiation doses to aircrew and astronauts to the controversial topic of its possible effect on climate change. In the case of terrestrial natural radiation, accounts are given of a number of human exposure scenarios. (author)

  5. Soil moisture estimation using reflected solar and emitted thermal infrared radiation

    Science.gov (United States)

    Jackson, R. D.; Cihlar, J.; Estes, J. E.; Heilman, J. L.; Kahle, A.; Kanemasu, E. T.; Millard, J.; Price, J. C.; Wiegand, C. L.

    1978-01-01

    Classical methods of measuring soil moisture such as gravimetric sampling and the use of neutron moisture probes are useful for cases where a point measurement is sufficient to approximate the water content of a small surrounding area. However, there is an increasing need for rapid and repetitive estimations of soil moisture over large areas. Remote sensing techniques potentially have the capability of meeting this need. The use of reflected-solar and emitted thermal-infrared radiation, measured remotely, to estimate soil moisture is examined.

  6. Overview of a benefit/risk ratio optimized for a radiation emitting device used in non-destructive testing

    Energy Technology Data Exchange (ETDEWEB)

    Maharaj, H.P., E-mail: H_P_Maharaj@hc-sc.gc.ca [Health Canada, Dept. of Health, Consumer and Clinical Radiaton Protection Bureau, Ottawa, Ontario (Canada)

    2016-03-15

    This paper aims to provide an overview of an optimized benefit/risk ratio for a radiation emitting device. The device, which is portable, hand-held, and open-beam x-ray tube based, is utilized by a wide variety of industries for purposes of determining elemental or chemical analyses of materials in-situ based on fluorescent x-rays. These analyses do not cause damage or permanent alteration of the test materials and are considered a non-destructive test (NDT). Briefly, the key characteristics, principles of use and radiation hazards associated with the Hay device are presented and discussed. In view of the potential radiation risks, a long term strategy that incorporates risk factors and guiding principles intended to mitigate the radiation risks to the end user was considered and applied. Consequently, an operator certification program was developed on the basis of an International Standards Organization (ISO) standard (ISO 20807:2004) and in collaboration with various stake holders and was implemented by a federal national NDT certification body several years ago. It comprises a written radiation safety examination and hands-on training with the x-ray device. The operator certification program was recently revised and the changes appear beneficial. There is a fivefold increase in operator certification (Levels 1 a nd 2) to date compared with earlier years. Results are favorable and promising. An operational guidance document is available to help mitigate radiation risks. Operator certification in conjunction with the use of the operational guidance document is prudent, and is recommended for end users of the x-ray device. Manufacturers and owners of the x-ray devices will also benefit from the operational guidance document. (author)

  7. Overview of a benefit/risk ratio optimized for a radiation emitting device used in non-destructive testing

    International Nuclear Information System (INIS)

    Maharaj, H.P.

    2016-01-01

    This paper aims to provide an overview of an optimized benefit/risk ratio for a radiation emitting device. The device, which is portable, hand-held, and open-beam x-ray tube based, is utilized by a wide variety of industries for purposes of determining elemental or chemical analyses of materials in-situ based on fluorescent x-rays. These analyses do not cause damage or permanent alteration of the test materials and are considered a non-destructive test (NDT). Briefly, the key characteristics, principles of use and radiation hazards associated with the Hay device are presented and discussed. In view of the potential radiation risks, a long term strategy that incorporates risk factors and guiding principles intended to mitigate the radiation risks to the end user was considered and applied. Consequently, an operator certification program was developed on the basis of an International Standards Organization (ISO) standard (ISO 20807:2004) and in collaboration with various stake holders and was implemented by a federal national NDT certification body several years ago. It comprises a written radiation safety examination and hands-on training with the x-ray device. The operator certification program was recently revised and the changes appear beneficial. There is a fivefold increase in operator certification (Levels 1 a nd 2) to date compared with earlier years. Results are favorable and promising. An operational guidance document is available to help mitigate radiation risks. Operator certification in conjunction with the use of the operational guidance document is prudent, and is recommended for end users of the x-ray device. Manufacturers and owners of the x-ray devices will also benefit from the operational guidance document. (author)

  8. Characteristics of radiation protection legislation

    International Nuclear Information System (INIS)

    Puig Cardozo, Diva E.

    2001-01-01

    The laws on radiological protection have special characteristics. They can exist laws that regulate dangerous activities that will be also applicable, if it corresponds to the activities that involve radioactive materials. But a law of radiological protection should exist. It foresees the existence of an appropriate regulatory body and specialized institutions, definitions, infractions and sanctions then the respective regulations will be elaborated for the different applications. The objective is to contribute to the development of the nuclear energy in the country and to provide the regulatory basis that assures a reasonable security for radioactive installations. The essential objectives of these laws are: 1. to establish the legislative framework for the development and employment of nuclear energy, without risks, according with treaties and conventions that the countries have approved. 2. To fix the fundamental principles and the conditions of their setting in practice allowing to a specific regulation determining application procedures. 3. To create a structure of regulation of enough authority to be able to control and to watch over in an effective way the authorized activities 4. To guarantee an appropriate financial protection against the derived damages of accidents or nuclear incidents. (author)

  9. Origin, characteristics and detection of nuclear radiation

    International Nuclear Information System (INIS)

    Goettel, K.

    1975-06-01

    The report is an introduction into the physical principles of radiation protection. After a brief summary of the most significant experimental results and data on the atomic structure of the matter and after explaining the principles of atomic and nuclear structure, radioactive decay and its laws are dealt with. This is followed by a representation of the characteristics of nuclear radiation, its interaction with the matter as well as the biological effects. After a description of the measurement units for radioactivity and doses the most inportant methods for radiation detection and the principles of how detectors function are explained. (ORU/LN) [de

  10. Electroluminescent Characteristics of DBPPV–ZnO Nanocomposite Polymer Light Emitting Devices

    Directory of Open Access Journals (Sweden)

    Madhava Rao MV

    2009-01-01

    Full Text Available Abstract We have demonstrated that fabrication and characterization of nanocomposite polymer light emitting devices with metal Zinc Oxide (ZnO nanoparticles and 2,3-dibutoxy-1,4-poly(phenylenevinylene (DBPPV. The current and luminance characteristics of devices with ZnO nanoparticles are much better than those of device with pure DBPPV. Optimized maximum luminance efficiencies of DBPPV–ZnO (3:1 wt% before annealing (1.78 cd/A and after annealing (2.45 cd/A having a brightness 643 and 776 cd/m2at a current density of 36.16 and 31.67 mA/cm2are observed, respectively. Current density–voltage and brightness–voltage characteristics indicate that addition of ZnO nanoparticles can facilitate electrical injection and charge transport. The thermal annealing is thought to result in the formation of an interfacial layer between emissive polymer film and cathode.

  11. Fabrication and characterization of UV-emitting nanoparticles as novel radiation sensitizers targeting hypoxic tumor cells

    Science.gov (United States)

    Squillante, Michael R.; Jüstel, Thomas; Anderson, R. Rox; Brecher, Charles; Chartier, Daniel; Christian, James F.; Cicchetti, Nicholas; Espinoza, Sara; McAdams, Daniel R.; Müller, Matthias; Tornifoglio, Brooke; Wang, Yimin; Purschke, Martin

    2018-06-01

    Radiation therapy is one of the primary therapeutic techniques for treating cancer, administered to nearly two-thirds of all cancer patients. Although largely effective in killing cancer cells, radiation therapy, like other forms of cancer treatment, has difficulty dealing with hypoxic regions within solid tumors. The incomplete killing of cancer cells can lead to recurrence and relapse. The research presented here is investigating the enhancement of the efficacy of radiation therapy by using scintillating nanoparticles that emit UV photons. UV photons, with wavelengths between 230 nm and 280 nm, are able to inactivate cells due to their direct interaction with DNA, causing a variety of forms of damage. UV-emitting nanoparticles will enhance the treatment in two ways: first by generating UV photons in the immediate vicinity of cancer cells, leading to direct and oxygen-independent DNA damage, and second by down-converting the applied higher energy X-rays into softer X-rays and particles that are more efficiently absorbed in the targeted tumor region. The end result will be nanoparticles with a higher efficacy in the treatment of hypoxic cells in the tumor, filling an important, unmet clinical need. Our preliminary experiments show an increase in cell death using scintillating LuPO4:Pr nanoparticles over that achieved by the primary radiation alone. This work describes the fabrication of the nanoparticles, their physical characterization, and the spectroscopic characterization of the UV emission. The work also presents in vitro results that demonstrate an enhanced efficacy of cell killing with x-rays and a low unspecific toxicity of the nanoparticles.

  12. Emission characteristics of VOCs emitted from consumer and commercial products and their ozone formation potential.

    Science.gov (United States)

    Dinh, Trieu-Vuong; Kim, Su-Yeon; Son, Youn-Suk; Choi, In-Young; Park, Seong-Ryong; Sunwoo, Young; Kim, Jo-Chun

    2015-06-01

    The characteristics of volatile organic compounds (VOCs) emitted from several consumer and commercial products (body wash, dishwashing detergent, air freshener, windshield washer fluid, lubricant, hair spray, and insecticide) were studied and compared. The spray products were found to emit the highest amount of VOCs (~96 wt%). In contrast, the body wash products showed the lowest VOC contents (~1.6 wt%). In the spray products, 21.6-96.4 % of the VOCs were propane, iso-butane, and n-butane, which are the components of liquefied petroleum gas. Monoterpene (C10H16) was the dominant component of the VOCs in the non-spray products (e.g., body wash, 53-88 %). In particular, methanol was present with the highest amount of VOCs in windshield washer fluid products. In terms of the number of carbon, the windshield washer fluids, lubricants, insecticides, and hair sprays comprised >95 % of the VOCs in the range C2-C5. The VOCs in the range C6-C10 were predominantly found in the body wash products. The dishwashing detergents and air fresheners contained diverse VOCs from C2 to C11. Besides comprising hazardous VOCs, VOCs from consumer products were also ozone precursors. The ozone formation potential of the consumer and commercial spray products was estimated to be higher than those of liquid and gel materials. In particular, the hair sprays showed the highest ozone formation potential.

  13. Effect of Dopant Activation on Device Characteristics of InGaN-based Light Emitting Diodes

    Science.gov (United States)

    Lacroce, Nicholas; Liu, Guangyu; Tan, Chee-Keong; Arif, Ronald A.; Lee, Soo Min; Tansu, Nelson

    2015-03-01

    Achieving high uniformity in growths and device characteristics of InGaN-based light-emitting diodes (LEDs) is important for large scale manufacturing. Dopant activation and maintaining control of variables affecting dopant activation are critical steps in the InGaN-based light emitting diodes (LEDs) fabrication process. In the epitaxy of large scale production LEDs, in-situ post-growth annealing is used for activating the Mg acceptor dopant in the p-AlGaN and p-GaN of the LEDs. However, the annealing temperature varies with respect to position in the reactor chamber, leading to severe uniform dopant activation issue across the devices. Thus, it is important to understand how the temperature gradient and the resulting variance in Mg acceptor activation will alter the device properties. In this work, we examine the effect of varying p-type doping levels in the p-GaN layers and AlGaN electron blocking layer of the GaN LEDs on the optoelectronic properties including the band profile, carrier concentration, current density, output power and quantum efficiency. By understanding the variations and its effect, the identification of the most critical p-type doping layer strategies to address this variation will be clarified.

  14. Characteristic Evaluation of Organic Light-Emitting Diodes Prepared with Stamp Printing Technique

    Directory of Open Access Journals (Sweden)

    Apisit Chittawanij

    2017-01-01

    Full Text Available We have reported on a stamp printing technique that uses PET release film as a printing stamp to deposit TPBi thin film served as the electron transport layer of the organic light-emitting diodes. TPBi thin film was printed with a good uniformity and resolution. Effect of deposition conditions on optical and electrical properties and surface roughness of TPBi thin film have been studied under spectroscopy and atomic force microscopy, respectively. It is found that characteristic of TPBi thin film is improved via controlled stamp temperature and time. Since TPBi thin film exhibits the surface morphology comparable to that of conventional spin-coating thin film, our findings suggest that PET release film-based stamp printing approach is possible to use as an alternative deposition of the organic thin film as compared with a traditional one.

  15. Volatiles emitted from flowers by gamma-radiated and nonradiated Jasminum polyanthum Franch. in situ

    International Nuclear Information System (INIS)

    Christensen, L.P.; Jakobsen, H.B.; Kristiansen, K.; Moller, J.

    1997-01-01

    Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%), eugenol (3.5%), 2-methoxy-p-cresol (3.1%), linalool (3.0%), phenethyl acetate (2.1%), and (Z)3-hexenyl butyrate (1.9%). The strong scent of Pepita reduces its production potentialities as a pot plant, thus the possibility to reduce or modify the emission of volatiles from Pepita by mutagenesis was investigated. The average total yields of volatiles in Pepita were approximately 2800 ng flower-1 h-1, and in one gamma-radiated clone a significantly lower yield of 1050 ng flower-1 h-1 was found. The volatile profiles of the gamma-radiated plants were made up of the same 32 compounds found in Pepita. Significant differences in the headspace composition between Pepita and gamma-radiated plants were found for some of the major volatiles

  16. Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)

    1995-09-01

    This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC.

  17. Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

    International Nuclear Information System (INIS)

    Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E.

    1995-09-01

    This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC

  18. Resonance effects of transition radiation emitted from thin foil stacks using electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Awata, Takaaki; Yajima, Kazuaki; Tanaka, Takashi [Kyoto Univ. (Japan). Faculty of Engineering; and others

    1997-03-01

    Transition Radiation(TR) X rays are expected to be a high brilliant X-ray source because the interference among TR X rays emitted from many thin foils placed periodically in vacuum can increase their intensity and make them quasi-monochromatic. In order to study the interference (resonance) effects of TR, we measured the energy spectra of TR for several sets of thin-foil stacks at various emission angles. It was found that the resonance effects of TR are classified into intrafoil and interfoil resonances and the intensity of TR X rays increases nonlinearly with increasing foil number, attributing to the interfoil resonance. It became evident that the brilliance of TR is as high as that of SR. (author)

  19. Degradation characteristics of waste polyurethane by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Seok; Ahn, Sung Jun; Gwon Hui Jeong; Jeong, Sung In; Nho, Young Chang; Lim, Youn Mook [Research Division for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2017-06-15

    Polyurethane (PU) is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, waste PU recycling has received significant attention due to environmental issues. The aim of this work was to investigate the degradation characteristics of waste PU to recycle. Degradation of waste PU was carried out using a radiation techniques. Waste PUs were exposed to a gamma {sup 60}Co sources. To verify degradation, the irradiated PUs were characterized using FT-IR, gel permeation chromatography (GPC), and their thermal/mechanical properties are reported. When the radiation dose was 500 kGy, the molecular weight of the waste PU drastically decreased. Also, the mechanical properties of waste PU were approximately 4 times lower than those of non-irradiated PU. This study has confirmed the possibility of making fine particle of waste PU for recycling through radiation degradation techniques.

  20. Elementary analysis of massive samples at excitation of characteristic x-radiation by proton beams

    International Nuclear Information System (INIS)

    Altynov, V.A.; Blokhin, S.M.; Brazevich, Eh.; Brazevich, Ya.; Lyu Zaj Ik; Osetinskij, G.M.; Purehv, A.

    1982-01-01

    A simplified method is described for calculating the elementary composition in the massive samples in the case of the detection of the characteristic X-radiation emitted under the bombardment of the samples by a beam of protons. The method was experimentally verified by measuring the characteristic X-radiation from the elements with a known concentration entering the one-component and multi-component matrix. It was shown that within the experimental accuracy the discussed method gave results analogous to those obtained with the earlier used methods

  1. Toxicologic study of electromagnetic radiation emitted by television and video display screens and cellular telephones on chickens and mice

    International Nuclear Information System (INIS)

    Bastide, M.; Youbicier-Simo, B.J.; Lebecq, J.C.; Giaimis, J.; Youbicier-Simo, B.J.

    2001-01-01

    The effects of continuous exposure of chick embryos and young chickens to the electromagnetic fields (EMFs) emitted by video display units (VDUs) and GSM cell phone radiation, either the whole spectrum emitted or attenuated by a copper gauze, were investigated. Permanent exposure to the EMFs radiated by a VDU was associated with significantly increased fetal loss (47-68%) and markedly depressed levels of circulating specific antibodies (lgG), corticosterone and melatonin. We have also shown that under chronic exposure conditions, GSM cell phone radiation was harmful to chick embryos, stressful for healthy mice and, in this species, synergistic with cancer insofar as it depleted stress hormones. The same pathological results were observed after substantial reduction of the microwaves radiated from the cell phone by attenuating them with a copper gauze. (author)

  2. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers

    Directory of Open Access Journals (Sweden)

    SMJ Mortazavi

    2013-01-01

    Full Text Available Background: Modern life prompted man to increasingly generate, transmit and use electricity that leads to exposure to different levels of electromagnetic fields (EMFs. Substantial evidence indicates that exposure to common sources of EMF such as mobile phones, laptops or wireless internet-connected laptops decreases human semen quality. In some countries, mobile jammers are occasionally used in offices, shrines, conference rooms and cinemas to block the signal. Aims: To the best of our knowledge, this is the first study to investigate the effect of short term exposure of human sperm samples to radiofrequency (RF radiations emitted by common mobile jammers. Subjects and Methods: Fresh semen samples were collected by masturbation from 30 healthy donors who had referred to Infertility Treatment Center at the Mother and Child Hospital with their wives. Female problem was diagnosed as the reason for infertility in these couples. Statistical Analysis: T-test and analysis of variance were used to show statistical significance. Results: The motility of sperm samples exposed to jammer RF radiation for 2 or 4 h were significantly lower than those of sham-exposed samples. These findings lead us to the conclusion that mobile jammers may significantly decrease sperm motility and the couples′ chances of conception. Conclusion: Based on these results, it can be suggested that in countries that have not banned mobile jammer use, legislations should be urgently passed to restrict the use of these signal blocking devices in public or private places.

  3. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers

    Science.gov (United States)

    Mortazavi, SMJ; Parsanezhad, ME; Kazempour, M; Ghahramani, P; Mortazavi, AR; Davari, M

    2013-01-01

    BACKGROUND: Modern life prompted man to increasingly generate, transmit and use electricity that leads to exposure to different levels of electromagnetic fields (EMFs). Substantial evidence indicates that exposure to common sources of EMF such as mobile phones, laptops or wireless internet-connected laptops decreases human semen quality. In some countries, mobile jammers are occasionally used in offices, shrines, conference rooms and cinemas to block the signal. AIMS: To the best of our knowledge, this is the first study to investigate the effect of short term exposure of human sperm samples to radiofrequency (RF) radiations emitted by common mobile jammers. SUBJECTS AND METHODS: Fresh semen samples were collected by masturbation from 30 healthy donors who had referred to Infertility Treatment Center at the Mother and Child Hospital with their wives. Female problem was diagnosed as the reason for infertility in these couples. STATISTICAL ANALYSIS: T-test and analysis of variance were used to show statistical significance. RESULTS: The motility of sperm samples exposed to jammer RF radiation for 2 or 4 h were significantly lower than those of sham-exposed samples. These findings lead us to the conclusion that mobile jammers may significantly decrease sperm motility and the couples’ chances of conception. CONCLUSION: Based on these results, it can be suggested that in countries that have not banned mobile jammer use, legislations should be urgently passed to restrict the use of these signal blocking devices in public or private places. PMID:24082653

  4. Instrumentation measurement and testing complex for detection and identification of radioactive materials using the emitted radiation

    International Nuclear Information System (INIS)

    Samossadny, V.T.; Dmitrenko, V.V.; Kadlin, V.V.; Kolesnikov, S.V.; Ulin, S.E.; Grachev, V.M.; Vlasik, K.F.; Dedenko, G.L.; Novikov, D.V.; Uteshev, Z.M.

    2006-01-01

    Simultaneous measurement of neutron and gamma radiation is a very usefull method for effective nuclear materials identification and control. The gamma-ray-neutron complex described in the paper is based on two multi-layer 3 He neutrons detectors and two High Pressure Xenon gamma-ray spectrometers assembled in one unit. All these detectors were callibrated on neutron and gamma-ray sources. The main characteristics of the instrumentation , its testing results and gamma-ray and neutron radiation parameters, which have been measured are represented in the paper. The gamma-neutron sources and fissile materials reliable detection and identification capability was demonstrated

  5. On the radiation emitted by a particle falling into a black hole in the semi-relativistic approximation

    International Nuclear Information System (INIS)

    Coretti, C.; Ferrari, V.

    1986-01-01

    In this paper the limits of applicability of the semi-relativistic approximation for estimating the radiation emitted in processes of capture of particles by black holes are discussed. It is shown that it gives reliable estimates in the case of spherically symmetric black holes, but it fails in the case of rotating black holes

  6. Cooling Characteristic Analysis of Transformer's Radiator

    International Nuclear Information System (INIS)

    Kim, Hyun Jae; Yang, Si Won; Kim, Won Seok; Kweon, Ki Yeoung; Lee, Min Jea

    2007-01-01

    A transformer is a device that changes the current and voltage by electricity induced between coil and core steel, and it is composed of metals and insulating materials. In the core of the transformer, the thermal load is generated by electric loss and the high temperature can make the break of insulating. So we must cool down the temperature of transformer by external radiators. According to cooling fan's usage, there are two cooling types, OA(Oil Natural Air Natural) and FA(Oil Natural Air Forced). For this study , we used Fluent 6.2 and analyzed the cooling characteristic of radiator. we calculated 1-fin of detail modeling that is similar to honeycomb structure and multi-fin(18-fin) calculation for OA and FA types. For the sensitivity study, we have different positions(side, under) of cooling fans for forced convection of FA type. The calculation results were compared with the measurement data which obtained from 135.45/69kV ultra transformer flowrate and temperature test. The aim of the study is to assess the Fluent code prediction on the radiator calculation and to use the data for optimizing transformer radiator design

  7. Modification in oxidative processes in muscle tissues exposed to laser- and light-emitting diode radiation.

    Science.gov (United States)

    Monich, Victor A; Bavrina, Anna P; Malinovskaya, Svetlana L

    2018-01-01

    Exposure of living tissues to high-intensity red or near-infrared light can produce the oxidative stress effects both in the target zone and adjacent ones. The protein oxidative modification (POM) products can be used as reliable and early markers of oxidative stress. The contents of modified proteins in the investigated specimens can be evaluated by the 2,4-dinitrophenylhydrazine assay (the DNPH assay). Low-intensity red light is able to decrease the activity of oxidative processes and the DNPH assay data about the POM products in the biological tissues could show both an oxidative stress level and an efficiency of physical agent protection against the oxidative processes. Two control groups of white rats were irradiated by laser light, the first control group by red light and the second one by near-infrared radiation (NIR).Two experimental groups were consequently treated with laser and red low-level light-emitting diode radiation (LED). One of them was exposed to red laser light + LED and the other to NIR + LED. The fifth group was intact. Each group included ten animals. The effect of laser light was studied by methods of protein oxidative modifications. We measured levels of both induced and spontaneous POM products by the DNPH assay. The dramatic increase in levels of POM products in the control group samples when compared with the intact group data as well as the sharp decrease in the POM products in the experimental groups treated with LED low-level light were statistically significant (p ≤ 0.05). Exposure of skeletal muscles to high-intensity red and near-infrared laser light causes oxidative stress that continues not less than 3 days. The method of measurement of POM product contents by the DNPH assay is a reliable test of an oxidative process rate. Red low-intensity LED radiation can provide rehabilitation of skeletal muscle tissues treated with high-intensity laser light.

  8. Influence of emissive layer thickness on electrical characteristics of polyfluorene copolymer based polymer light emitting diodes

    International Nuclear Information System (INIS)

    Das, D; Gopikrishna, P; Singh, A; Dey, A; Iyer, P K

    2016-01-01

    Polymer light emitting diodes (PLEDs) with a device configuration of ITO/PEDOT:PSS/PFONPN01 [Poly [2,7-(9,9’-dioctylfluorene)-co-N-phenyl-1,8-naphthalimide (99:01)]/LiF/Al have been fabricated by varying the emissive layer (EML) thickness (40/65/80/130 nm) and the influence of EML thickness on the electrical characteristics of PLED has been studied. PLED can be modelled as a simple combination of resistors and capacitors. The impedance spectroscopy analysis showed that the devices with different EML thickness had different values of parallel resistance (R P ) and the parallel capacitance (C P ). The impedance of the devices is found to increase with increasing EML thickness resulting in an increase in the driving voltage. The device with an emissive layer thickness of 80nm, spin coated from a solution of concentration 15 mg/mL is found to give the best device performance with a maximum brightness value of 5226 cd/m 2 . (paper)

  9. Measurement and calculation of characteristic prompt gamma ray spectra emitted during proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Polf, J C; Peterson, S; Beddar, S [M D Anderson Cancer Center, Univeristy of Texas, Houston, TX 77030 (United States); McCleskey, M; Roeder, B T; Spiridon, A; Trache, L [Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States)], E-mail: jcpolf@mdanderson.org

    2009-11-21

    In this paper, we present results of initial measurements and calculations of prompt gamma ray spectra (produced by proton-nucleus interactions) emitted from tissue equivalent phantoms during irradiations with proton beams. Measurements of prompt gamma ray spectra were made using a high-purity germanium detector shielded either with lead (passive shielding), or a Compton suppression system (active shielding). Calculations of the spectra were performed using a model of both the passive and active shielding experimental setups developed using the Geant4 Monte Carlo toolkit. From the measured spectra it was shown that it is possible to distinguish the characteristic emission lines from the major elemental constituent atoms (C, O, Ca) in the irradiated phantoms during delivery of proton doses similar to those delivered during patient treatment. Also, the Monte Carlo spectra were found to be in very good agreement with the measured spectra providing an initial validation of our model for use in further studies of prompt gamma ray emission during proton therapy. (note)

  10. Chemical characteristics of fine particles emitted from different gas cooking methods

    Science.gov (United States)

    See, Siao Wei; Balasubramanian, Rajasekhar

    Gas cooking is an important indoor source of fine particles (PM 2.5). The chemical characteristics of PM 2.5 emitted from different cooking methods, namely, steaming, boiling, stir-frying, pan-frying and deep-frying were investigated in a domestic kitchen. Controlled experiments were conducted to measure the mass concentration of PM 2.5 and its chemical constituents (elemental carbon (EC), organic carbon (OC), polycyclic aromatic hydrocarbons (PAHs), metals and ions) arising from these five cooking methods. To investigate the difference in particle properties of different cooking emissions, the amount and type of food, and the heat setting on the gas stove were kept constant during the entire course of the experiments. Results showed that deep-frying gave rise to the largest amount of PM 2.5 and most chemical components, followed by pan-frying, stir-frying, boiling, and steaming. Oil-based cooking methods released more organic pollutants (OC, PAHs, and organic ions) and metals, while water-based cooking methods accounted for more water-soluble (WS) ions. Their source profiles are also presented and discussed.

  11. Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings

    Science.gov (United States)

    Johnson, C. F.; Brown, C. S.; Wheeler, R. M.; Sager, J. C.; Chapman, D. K.; Deitzer, G. F.

    1996-01-01

    Oat (Avena sativa cv Seger) seedlings were irradiated with IR light-emitting diode (LED) radiation passed through a visible-light-blocking filter. Infrared LED irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. Thus, the oat seedlings in this study were able to detect IR LED radiation. These findings call into question the use of IR LED as a safe-light for some photosensitive plant response experiments. These findings also expand the defined range of wavelengths involved in radiation-gravity (light-gravity) interactions to include wavelengths in the IR region of the spectrum.

  12. The effect of electromagnetic radiation emitted by display screens on cell oxygen metabolism - in vitro studies.

    Science.gov (United States)

    Lewicka, Małgorzata; Henrykowska, Gabriela A; Pacholski, Krzysztof; Śmigielski, Janusz; Rutkowski, Maciej; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

    2015-12-10

    Research studies carried out for decades have not solved the problem of the effect of electromagnetic radiation of various frequency and strength on the human organism. Due to this fact, we decided to investigate the changes taking place in human blood platelets under the effect of electromagnetic radiation (EMR) emitted by LCD monitors. The changes of selected parameters of oxygen metabolism were measured, i.e. reactive oxygen species concentration, enzymatic activity of antioxidant defence proteins - superoxide dismutase (SOD-1) and catalase (CAT) - and malondialdehyde concentration (MDA). A suspension of human blood platelets was exposed to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity for 30 and 60 min. The level of changes of the selected parameters of oxidative stress was determined after the exposure and compared to the control samples (not exposed). The measurements revealed an increase of the concentration of reactive oxygen species. The largest increase of ROS concentration vs. the control sample was observed after exposure to EMF of 220 V/m intensity for 60 min (from x = 54.64 to x = 72.92). The measurement of MDA concentration demonstrated a statistically significant increase after 30-min exposure to an EMF of 220 V/m intensity in relation to the initial values (from x = 3.18 to x = 4.41). The enzymatic activity of SOD-1 decreased after exposure (the most prominent change was observed after 60-min and 220 V/m intensity from x = 3556.41 to x = 1084.83). The most significant change in activity of catalase was observed after 60 min and 220 v/m exposure (from x = 6.28 to x = 4.15). The findings indicate that exposure to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity may cause adverse effects within blood platelets' oxygen metabolism and thus may lead to physiological dysfunction of the organism.

  13. Effects of radiofrequency radiation emitted by cellular telephones on the cognitive functions of humans.

    Science.gov (United States)

    Eliyahu, Ilan; Luria, Roy; Hareuveny, Ronen; Margaliot, Menachem; Meiran, Nachshon; Shani, Gad

    2006-02-01

    The present study examined the effects of exposure to Electromagnetic Radiation emitted by a standard GSM phone at 890 MHz on human cognitive functions. This study attempted to establish a connection between the exposure of a specific area of the brain and the cognitive functions associated with that area. A total of 36 healthy right-handed male subjects performed four distinct cognitive tasks: spatial item recognition, verbal item recognition, and two spatial compatibility tasks. Tasks were chosen according to the brain side they are assumed to activate. All subjects performed the tasks under three exposure conditions: right side, left side, and sham exposure. The phones were controlled by a base station simulator and operated at their full power. We have recorded the reaction times (RTs) and accuracy of the responses. The experiments consisted of two sections, of 1 h each, with a 5 min break in between. The tasks and the exposure regimes were counterbalanced. The results indicated that the exposure of the left side of the brain slows down the left-hand response time, in the second-later-part of the experiment. This effect was apparent in three of the four tasks, and was highly significant in only one of the tests. The exposure intensity and its duration exceeded the common exposure of cellular phone users.

  14. Development of Radiation-Resistant In-Water Wireless Transmission System Using Light Emitting Diodes and Photo Diodes

    Science.gov (United States)

    Takeuchi, T.; Shibata, H.; Otsuka, N.; Uehara, T.; Tsuchiya, K.; Shibagaki, T.; Komanome, H.

    2016-10-01

    Several kinds of commercially available light emitting diodes (LED) and photo diodes (PD) were irradiated with 60Co gamma ray up to 1 MGy for development of a radiation-resistant in-water wireless transmission system using visible light. The lens parts of the LEDs turned brown by the irradiation and their colors became dark with the absorbed dose. The total luminous fluxes decreased with the absorbed dose and the LED with shorter emission wavelength had the higher decrease rate. Meanwhile, the current-voltage characteristics hardly changed. These results indicate that the decreases of the total luminous flux of the LEDs were mainly caused not by the degradation of the semiconductor parts but by the coloring of the lens parts by the irradiation. On the other hand, the light sensitivities of the PDs decreased with the absorbed dose. The PDs with the window part which turned a darker color had the higher decrease rate. These results indicate that the decreases of light sensitivities of the PDs were also mainly caused by the coloring of the resin parts by the irradiation. If the wireless transmission is performed using the candidate LED and PD between 5 meters in water, using a few LEDs and PDs, the PD's output current generated by the emission light of the LED is estimated to be detectable even considering the effects of the absorption of the light in water and the increased dark current by the irradiation. Therefore, a radiation resistant in-water transmission system can be constructed using commercially available LEDs and PDs in principle.

  15. Radiative characteristics of CVL pumped dye laser

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Uichi; Ishiguro, Takahide

    1987-09-01

    This paper describes the radiative characteristics of CVL pumped dye laser. It is compared YAG-SH (530 nm) with CVL (511, 578 nm) and CVL (511 nm) for pumping source. Influence of solvent in dye laser power was examined. The present experimental results show that efficiency of CVL (511 nm) pumped dye laser was most high. When the dye solution is at a standstill, the efficiency of dye laser with water and Sodium Lauryl Sulfate (S.L.S., 2 %wt.) was most high among the four kinds of solvent. In the condition of dye solution flow, the water and S.L.S. or ethylene glycol was useful solvent for dye laser.

  16. Radiative characteristics of CVL pumped dye laser

    International Nuclear Information System (INIS)

    Kubo, Uichi; Ishiguro, Takahide.

    1987-01-01

    This paper describes the radiative characteristics of CVL pumped dye laser. It is compared YAG-SH (530 nm) with CVL (511, 578 nm) and CVL (511 nm) for pumping source. Influence of solvent in dye laser power was examined. The present experimental results show that efficiency of CVL (511 nm) pumped dye laser was most high. When the dye solution is at a standstill, the efficiency of dye laser with water and Sodium Lauryl Sulfate (S.L.S., 2 %wt.) was most high among the four kinds of solvent. In the condition of dye solution flow, the water and S.L.S. or Ethylene Glycol was useful solvent for dye laser. (author)

  17. Decay Curves and Half-Lives of Gamma-Emitting States from a Study of Prompt Fission Gamma Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

    1971-04-15

    Measurements were made on the time distributions of the prompt gamma radiation emitted from fragments in the thermal-neutron induced fission of 235U. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fragments. In this way decay curves were obtained from which half-lives could be estimated. Time components with half-lives of 7.5, 18 and 60 ps were found and their relative intensities were calculated. Half-lives and associated intensities are in good agreement with earlier data from uranium and californium fission. Problems involved in this type of study are discussed. The collimator technique has proved to be effective for determination of half lives down to less than 10 ps

  18. Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media

    Science.gov (United States)

    Stamnes, Knut; Tsay, S.-CHEE; Jayaweera, Kolf; Wiscombe, Warren

    1988-01-01

    The transfer of monochromatic radiation in a scattering, absorbing, and emitting plane-parallel medium with a specified bidirectional reflectivity at the lower boundary is considered. The equations and boundary conditions are summarized. The numerical implementation of the theory is discussed with attention given to the reliable and efficient computation of eigenvalues and eigenvectors. Ways of avoiding fatal overflows and ill-conditioning in the matrix inversion needed to determine the integration constants are also presented.

  19. Moisture exposure to different layers in organic light-emitting diodes and the effect on electroluminescence characteristics

    International Nuclear Information System (INIS)

    Liao, L. S.; Tang, C. W.

    2008-01-01

    Moisture effect on electroluminescence characteristics, including current density versus voltage, luminance versus voltage, luminous efficiency versus current density, dark spot formation, and operational stability of organic light-emitting diodes, has been systematically investigated by exposing each layer of the devices to moisture at room temperature. Moisture has a different effect on each of the interfaces or surfaces, and the influence increases as exposure time increases. There is a slight effect on the electroluminescence characteristics after the anode surface has been exposed to moisture. However, severe luminance decrease, dark spot formation, and operational stability degradation take place after the light-emitting layer or the electron-transporting layer is exposed to moisture. It is also demonstrated that the effect of moisture can be substantially reduced if the exposure to moisture is in a dark environment

  20. Ideality factor of GaN-based light-emitting diodes determined by the measurement of photovoltaic characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Joong; Ryu, Geun-Hwan; Yang, Won-Bo; Ryu, Han-Youl [Inha University, Incheon (Korea, Republic of)

    2014-11-15

    We present a method for determining the ideality factor of GaN-based light-emitting diodes (LEDs) by using the measured photovoltaic characteristics. The relation between the short-circuit current and the open-circuit voltage is obtained as the incident power of a laser diode emitting at 405 nm is varied, which is used to determine the ideality factor of the LED. From the photovoltaic measurements, the ideality factors of a blue and a green LED are determined to be 1.16 and 1.78, respectively. The ideality factors obtained by using the photovoltaic measurement are found to be much smaller than those obtained by using the I - V curve without illumination, which is believed to result from the different carrier generation and transport mechanisms. Investigating the photovoltaic characteristics of GaN-based LEDs is expected to provide insight into the origin of the high diode ideality factor in GaN-based devices.

  1. Ideality factor of GaN-based light-emitting diodes determined by the measurement of photovoltaic characteristics

    International Nuclear Information System (INIS)

    Kim, Hyun-Joong; Ryu, Geun-Hwan; Yang, Won-Bo; Ryu, Han-Youl

    2014-01-01

    We present a method for determining the ideality factor of GaN-based light-emitting diodes (LEDs) by using the measured photovoltaic characteristics. The relation between the short-circuit current and the open-circuit voltage is obtained as the incident power of a laser diode emitting at 405 nm is varied, which is used to determine the ideality factor of the LED. From the photovoltaic measurements, the ideality factors of a blue and a green LED are determined to be 1.16 and 1.78, respectively. The ideality factors obtained by using the photovoltaic measurement are found to be much smaller than those obtained by using the I - V curve without illumination, which is believed to result from the different carrier generation and transport mechanisms. Investigating the photovoltaic characteristics of GaN-based LEDs is expected to provide insight into the origin of the high diode ideality factor in GaN-based devices.

  2. Evaluation of scattered radiation emitted from X-ray security scanners on occupational dose to airport personnel

    International Nuclear Information System (INIS)

    Dalah, Entesar; Fakhry, Angham; Mukhtar, Asma; Al Salti, Farah; Bader, May; Khouri, Sara; Al-Zahmi, Reem

    2017-01-01

    Based on security issues and regulations airports are provided with luggage cargo scanners. These scanners utilize ionizing radiation that in principle present health risks toward humans. The study aims to investigate the amount of backscatter produced by passenger luggage and cargo toward airport personnel who are located at different distances from the scanners. To approach our investigation a Thermo Electron Radeye-G probe was used to quantify the backscattered radiation measured in terms of dose-rate emitted from airport scanners, Measurements were taken at the entrance and exit positions of the X-ray tunnel at three different distances (0, 50, and 100 cm) for two different scanners; both scanners include shielding curtains that reduce scattered radiation. Correlation was demonstrated using the Pearson coefficient test. Measurements confirmed an inverse relationship between dose rate and distance. An estimated occupational accumulative dose of 0.88 mSv/y, and 2.04 mSv/y were obtained for personnel working in inspection of carry-on, and cargo, respectively. Findings confirm that the projected dose of security and engineering staff are being well within dose limits. - Highlights: • Backscattered radiation emitted from the airport security scanners is estimated. • Inverse relation observed between backscattered radiation and scanners distance. • Occupational dose for personnel inspecting the scanners were up to 2.04 mSv/y. • The projected dose of security and engineering staff are well within dose limits.

  3. Estimation of soft X-ray and EUV transition radiation power emitted from the MIRRORCLE-type tabletop synchrotron.

    Science.gov (United States)

    Toyosugi, N; Yamada, H; Minkov, D; Morita, M; Yamaguchi, T; Imai, S

    2007-03-01

    The tabletop synchrotron light sources MIRRORCLE-6X and MIRRORCLE-20SX, operating at electron energies E(el) = 6 MeV and E(el) = 20 MeV, respectively, can emit powerful transition radiation (TR) in the extreme ultraviolet (EUV) and the soft X-ray regions. To clarify the applicability of these soft X-ray and EUV sources, the total TR power has been determined. A TR experiment was performed using a 385 nm-thick Al foil target in MIRRORCLE-6X. The angular distribution of the emitted power was measured using a detector assembly based on an NE102 scintillator, an optical bundle and a photomultiplier. The maximal measured total TR power for MIRRORCLE-6X is P(max) approximately equal 2.95 mW at full power operation. Introduction of an analytical expression for the lifetime of the electron beam allows calculation of the emitted TR power by a tabletop synchrotron light source. Using the above measurement result, and the theoretically determined ratio between the TR power for MIRRORCLE-6X and MIRRORCLE-20SX, the total TR power for MIRRORCLE-20SX can be obtained. The one-foil TR target thickness is optimized for the 20 MeV electron energy. P(max) approximately equal 810 mW for MIRRORCLE-20SX is obtained with a single foil of 240 nm-thick Be target. The emitted bremsstrahlung is negligible with respect to the emitted TR for optimized TR targets. From a theoretically known TR spectrum it is concluded that MIRRORCLE-20SX can emit 150 mW of photons with E > 500 eV, which makes it applicable as a source for performing X-ray lithography. The average wavelength, \\overline\\lambda = 13.6 nm, of the TR emission of MIRRORCLE-20SX, with a 200 nm Al target, could provide of the order of 1 W EUV.

  4. Assessment of radiation emitted by the colour video monitors using a silicon surface-barrier detection system

    International Nuclear Information System (INIS)

    Tykva, R.; Sabol, J.

    1998-01-01

    About 5% of the commonly used colour monitors tested showed radiation levels on the screen surface approaching the dose rate of 5 μGy/h. There is practically no difference between 'low radiation' monitors and other monitors. The level of radiation emitted to the sides is generally higher than that of X-ray photons emerging from the surface of the screen. Although the contribution to the effective dose of a person exposed to radiation from the monitors may be below the limit set for the general public, the skin and eye lens dose may reach significant levels, taking into account some factors such as a high density of monitors in small rooms, short distance, long exposure time, etc. (M.D.)

  5. Modeling and parameterization of photoelectrons emitted in condensed matter by linearly polarized synchrotron radiation

    Science.gov (United States)

    Jablonski, A.

    2018-01-01

    Growing availability of synchrotron facilities stimulates an interest in quantitative applications of hard X-ray photoemission spectroscopy (HAXPES) using linearly polarized radiation. An advantage of this approach is the possibility of continuous variation of radiation energy that makes it possible to control the sampling depth for a measurement. Quantitative applications are based on accurate and reliable theory relating the measured spectral features to needed characteristics of the surface region of solids. A major complication in the case of polarized radiation is an involved structure of the photoemission cross-section for hard X-rays. In the present work, details of the relevant formalism are described and algorithms implementing this formalism for different experimental configurations are proposed. The photoelectron signal intensity may be considerably affected by variation in the positioning of the polarization vector with respect to the surface plane. This information is critical for any quantitative application of HAXPES by polarized X-rays. Different quantitative applications based on photoelectrons with energies up to 10 keV are considered here: (i) determination of surface composition, (ii) estimation of sampling depth, and (iii) measurements of an overlayer thickness. Parameters facilitating these applications (mean escape depths, information depths, effective attenuation lengths) were calculated for a number of photoelectron lines in four elemental solids (Si, Cu, Ag and Au) in different experimental configurations and locations of the polarization vector. One of the considered configurations, with polarization vector located in a plane perpendicular to the surface, was recommended for quantitative applications of HAXPES. In this configurations, it was found that the considered parameters vary weakly in the range of photoelectron emission angles from normal emission to about 50° with respect to the surface normal. The averaged values of the mean

  6. Optical spectroscopy and microscopy of radiation-induced light-emitting point defects in lithium fluoride crystals and films

    Science.gov (United States)

    Montereali, R. M.; Bonfigli, F.; Menchini, F.; Vincenti, M. A.

    2012-08-01

    Broad-band light-emitting radiation-induced F2 and F3+ electronic point defects, which are stable and laser-active at room temperature in lithium fluoride crystals and films, are used in dosimeters, tuneable color-center lasers, broad-band miniaturized light sources and novel radiation imaging detectors. A brief review of their photoemission properties is presented, and their behavior at liquid nitrogen temperatures is discussed. Some experimental data from optical spectroscopy and fluorescence microscopy of these radiation-induced point defects in LiF crystals and thin films are used to obtain information about the coloration curves, the efficiency of point defect formation, the effects of photo-bleaching processes, etc. Control of the local formation, stabilization, and transformation of radiation-induced light-emitting defect centers is crucial for the development of optically active micro-components and nanostructures. Some of the advantages of low temperature measurements for novel confocal laser scanning fluorescence microscopy techniques, widely used for spatial mapping of these point defects through the optical reading of their visible photoluminescence, are highlighted.

  7. Combined Natural Convection and Radiation Heat Transfer of Various Absorbing-Emitting-Scattering Media in a Square Cavity

    Directory of Open Access Journals (Sweden)

    Xianglong Liu

    2014-01-01

    Full Text Available A numerical model is developed to simulate combined natural convection and radiation heat transfer of various anisotropic absorbing-emitting-scattering media in a 2D square cavity based on the discrete ordinate (DO method and Boussinesq assumption. The effects of Rayleigh number, optical thickness, scattering ratio, scattering phase function, and aspect ratio of square cavity on the behaviors of heat transfer are studied. The results show that the heat transfer of absorbing-emitting-scattering media is the combined results of radiation and natural convection, which depends on the physical properties and the aspect ratio of the cavity. When the natural convection becomes significant, the convection heat transfer is enhanced, and the distributions of NuR and Nuc along the walls are obviously distorted. As the optical thickness increases, NuR along the hot wall decreases. As the scattering ratio decreases, the NuR along the walls decreases. At the higher aspect ratio, the more intensive thermal radiation and natural convection are formed, which increase the radiation and convection heat fluxes. This paper provides the theoretical research for the optimal thermal design and practical operation of the high temperature industrial equipments.

  8. X-ray Emitting GHz-Peaked Spectrum Galaxies: Testing a Dynamical-Radiative Model with Broad-Band Spectra

    International Nuclear Information System (INIS)

    Ostorero, L.; Moderski, R.; Stawarz, L.; Diaferio, A.; Kowalska, I.; Cheung, C.C.; Kataoka, J.; Begelman, M.C.; Wagner, S.J.

    2010-01-01

    In a dynamical-radiative model we recently developed to describe the physics of compact, GHz-Peaked-Spectrum (GPS) sources, the relativistic jets propagate across the inner, kpc-sized region of the host galaxy, while the electron population of the expanding lobes evolves and emits synchrotron and inverse-Compton (IC) radiation. Interstellar-medium gas clouds engulfed by the expanding lobes, and photoionized by the active nucleus, are responsible for the radio spectral turnover through free-free absorption (FFA) of the synchrotron photons. The model provides a description of the evolution of the GPS spectral energy distribution (SED) with the source expansion, predicting significant and complex high-energy emission, from the X-ray to the γ-ray frequency domain. Here, we test this model with the broad-band SEDs of a sample of eleven X-ray emitting GPS galaxies with Compact-Symmetric-Object (CSO) morphology, and show that: (i) the shape of the radio continuum at frequencies lower than the spectral turnover is indeed well accounted for by the FFA mechanism; (ii) the observed X-ray spectra can be interpreted as non-thermal radiation produced via IC scattering of the local radiation fields off the lobe particles, providing a viable alternative to the thermal, accretion-disk dominated scenario. We also show that the relation between the hydrogen column densities derived from the X-ray (N H ) and radio (N HI ) data of the sources is suggestive of a positive correlation, which, if confirmed by future observations, would provide further support to our scenario of high-energy emitting lobes.

  9. Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study

    Directory of Open Access Journals (Sweden)

    Rafati A.

    2015-09-01

    Full Text Available Introduction: The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects of exposure to radiofrequency (RF radiation emitted from mobile phone jammers on the pulse height of contractions, the time interval between two subsequent contractions and the latency period of frog’s isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz. Materials and Methods: Frogs were kept in plastic containers in a room. Animals in the jammer group were exposed to radiofrequency (RF radiation emitted from a common Jammer at a distance of 1m from the jammer’s antenna for 2 hours while the control frogs were only sham exposed. Then animals were sacrificed and isolated gastrocnemius muscles were exposed to on/off jammer radiation for 3 subsequent 10 minute intervals. Isolated gastrocnemius muscles were attached to the force transducer with a string. Using a PowerLab device (26-T, the pattern of muscular contractions was monitored after applying single square pulses of 1V (1 Hz as stimuli. Results: The findings of this study showed that the pulse height of muscle contractions could not be affected by the exposure to electromagnetic fields. However, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. Conclusion: These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

  10. Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study.

    Science.gov (United States)

    Rafati, A; Rahimi, S; Talebi, A; Soleimani, A; Haghani, M; Mortazavi, S M J

    2015-09-01

    The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted from mobile phone jammers on the pulse height of contractions, the time interval between two subsequent contractions and the latency period of frog's isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz). Frogs were kept in plastic containers in a room. Animals in the jammer group were exposed to radiofrequency (RF) radiation emitted from a common Jammer at a distance of 1m from the jammer's antenna for 2 hours while the control frogs were only sham exposed. Then animals were sacrificed and isolated gastrocnemius muscles were exposed to on/off jammer radiation for 3 subsequent 10 minute intervals. Isolated gastrocnemius muscles were attached to the force transducer with a string. Using a PowerLab device (26-T), the pattern of muscular contractions was monitored after applying single square pulses of 1V (1 Hz) as stimuli. The findings of this study showed that the pulse height of muscle contractions could not be affected by the exposure to electromagnetic fields. However, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

  11. High-energy coherent terahertz radiation emitted by wide-angle electron beams from a laser-wakefield accelerator

    Science.gov (United States)

    Yang, Xue; Brunetti, Enrico; Jaroszynski, Dino A.

    2018-04-01

    High-charge electron beams produced by laser-wakefield accelerators are potentially novel, scalable sources of high-power terahertz radiation suitable for applications requiring high-intensity fields. When an intense laser pulse propagates in underdense plasma, it can generate femtosecond duration, self-injected picocoulomb electron bunches that accelerate on-axis to energies from 10s of MeV to several GeV, depending on laser intensity and plasma density. The process leading to the formation of the accelerating structure also generates non-injected, sub-picosecond duration, 1–2 MeV nanocoulomb electron beams emitted obliquely into a hollow cone around the laser propagation axis. These wide-angle beams are stable and depend weakly on laser and plasma parameters. Here we perform simulations to characterise the coherent transition radiation emitted by these beams if passed through a thin metal foil, or directly at the plasma–vacuum interface, showing that coherent terahertz radiation with 10s μJ to mJ-level energy can be produced with an optical to terahertz conversion efficiency up to 10‑4–10‑3.

  12. Finite volume method for radiative heat transfer in an unstructured flow solver for emitting, absorbing and scattering media

    International Nuclear Information System (INIS)

    Gazdallah, Moncef; Feldheim, Véronique; Claramunt, Kilian; Hirsch, Charles

    2012-01-01

    This paper presents the implementation of the finite volume method to solve the radiative transfer equation in a commercial code. The particularity of this work is that the method applied on unstructured hexahedral meshes does not need a pre-processing step establishing a particular marching order to visit all the control volumes. The solver simply visits the faces of the control volumes as numbered in the hexahedral unstructured mesh. A cell centred mesh and a spatial differencing step scheme to relate facial radiative intensities to nodal intensities is used. The developed computer code based on FVM has been integrated in the CFD solver FINE/Open from NUMECA Int. Radiative heat transfer can be evaluated within systems containing uniform, grey, emitting, absorbing and/or isotropically or linear anisotropically scattering medium bounded by diffuse grey walls. This code has been validated for three test cases. The first one is a three dimensional rectangular enclosure filled with emitting, absorbing and anisotropically scattering media. The second is the differentially heated cubic cavity. The third one is the L-shaped enclosure. For these three test cases a good agreement has been observed when temperature and heat fluxes predictions are compared with references taken, from literature.

  13. Stability of semiconductor memory characteristics in a radiation environment

    OpenAIRE

    Fetahović, I.; Vujisić, M.; Stanković, K.; Dolićanin, E.

    2015-01-01

    Radiation defects in electronic device can occur in a process of its fabrication or during use. Miniaturization trends in industry and increase in level of integration of electronic components have negative affect on component's behavior in a radiation environment. The aim of this paper is to analyze radiation effects in semiconductor memories and to establish how ionizing radiation influences characteristics and functionality of semiconductor memories. Both the experimental procedure and sim...

  14. Volatiles emitted from flowers of gamma-radiated and nonradiated Jasminum polyanthum Franch

    DEFF Research Database (Denmark)

    Christensen, Lars P; Jakobsen, Henrik B; Kristiansen, Kell

    1997-01-01

    Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%),...

  15. Structural, electrical and luminescent characteristics of ultraviolet light emitting structures grown by hydride vapor phase epitaxy

    Directory of Open Access Journals (Sweden)

    A.Y. Polyakov

    2017-03-01

    Full Text Available Electrical and luminescent properties of near-UV light emitting diode structures (LEDs prepared by hydride vapor phase epitaxy (HVPE were studied. Variations in photoluminescence and electroluminescence efficiency observed for LEDs grown under nominally similar conditions could be attributed to the difference in the structural quality (dislocation density, density of dislocations agglomerates of the GaN active layers, to the difference in strain relaxation achieved by growth of AlGaN/AlGaN superlattice and to the presence of current leakage channels in current confining AlGaN layers of the double heterostructure.

  16. Search for characteristics of preequilibrium protons emitted in Ar + Ag collisions at E/A = 27 MeV

    International Nuclear Information System (INIS)

    Jouan, D.; Rivet, M.F.; Borderie, B.; Gauvin, H.; Cabot, C.; Fuchs, H.; Gardes, D.; Jacquet, D.; Monnet, F.; Montoya, M.

    1987-12-01

    Protons emitted in coincidence with heavy residues have been measured, for the reaction 27 MeV per nucleon 40 Ar + nat Ag. From the proton velocity spectra, an anisotropic component was extracted, which shows a broad angular distribution, and a mean velocity larger than the beam velocity. Multiplicities for this component are low, about 0.8, independent of the violence of the collision. For central collisions, selected via the higher heavy residue velocities, the velocity characteristics of the anisotropic component, seen in this case as a pure preequilibrium component, were compared to semi-classical calculations (Landau-Vlasov)

  17. Automatic control by natural gamma radiation emitted by coal; Control Automatico mediante Radiometria Gamma Natural de la Cenizas de los Carbones

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Due to the characteristics of its coal and orebody, Monsacro shaft was chosen to host the test. The ash percentage of the different coal seams was carried out by two different methods: Traditional analysis in laboratory. Analysis by means of natural gamma radiation emitted by coal. The following conclusions were obtained after the test: Neither during the mounting nor during the test, a problem was encountered in the working of the radioactive methods. The absolute error between the two methods was minimum. The radioactive analysis is total (this means that the whole coal is analysed) and it is carried out in short period of time. The traditional one is just partial, and could take a few hours to accomplish it. The radioactive one is done in the wagon or in the belt conveyor directly, meanwhile the traditional one needs sample takers permanently. The investment cost of the radioactivity method is amortized within two years. (Author)

  18. Preliminary results on soil-emitted gamma radiation and its relation with the local atmospheric electric field at Amieira (Portugal)

    International Nuclear Information System (INIS)

    Lopes, F; Barbosa, S M; Silva, H G; Bárias, S

    2015-01-01

    The atmospheric electric field near the Earth's surface is dominated by atmospheric pollutants and natural radioactivity, with the latter directly linked to radon ( 222 Rn) gas. For a better comprehension on the temporal variability of both the atmospheric electric field and the radon concentration and its relation with local atmospheric variables, simultaneous measurements of soil-emitted gamma radiation and potential gradient (defined from the vertical component of the atmospheric electric field) were taken every minute, along with local meteorological parameters (e.g., temperature, atmospheric pressure, relative humidity and daily solar radiation). The study region is Amieira, part of the Alqueva lake in Alentejo Portugal, where an interdisciplinary meteorological campaign, ALEX2014, took place from June to August 2014. Soil gamma radiation is more sensitive to small concentrations of radon as compared with alpha particles measurements, for that reason it is more suited for sites with low radon levels, as expected in this case. Preliminary results are presented here: statistical and spectral analysis show that i) the potential gradient has a stronger daily cycle as compared with the gamma radiation, ii) most of the energy of the gamma signal is concentrated in the low frequencies (close to 0), contrary to the potential gradient that has most of the energy in frequency 1 (daily cycle) and iii) a short-term relation between gamma radiation and the potential gradient has not been found. Future work and plans are also discussed. (paper)

  19. Assessment of radiofrequency/microwave radiation emitted by the antennas of rooftop-mounted mobile phone base stations

    International Nuclear Information System (INIS)

    Keow, M. A.; Radiman, S.

    2006-01-01

    Radiofrequency (RF) and microwave (MW) radiation exposures from the antennas of rooftop-mounted mobile telephone base stations have become a serious issue in recent years due to the rapidly evolving technologies in wireless telecommunication systems. In Malaysia, thousands of mobile telephone base stations have been erected all over the country, most of which are mounted on the rooftops. In view of public concerns, measurements of the RF/MW levels emitted by the base stations were carried out in this study. The values were compared with the exposure limits set by several organisations and countries. Measurements were performed at 200 sites around 47 mobile phone base stations. It was found that the RF/MW radiation from these base stations were well below the maximum exposure limits set by various agencies. (authors)

  20. The simulation of thermal characteristics of 980 nm vertical cavity surface emitting lasers

    Science.gov (United States)

    Fang, Tianxiao; Cui, Bifeng; Hao, Shuai; Wang, Yang

    2018-02-01

    In order to design a single mode 980 nm vertical cavity surface emitting laser (VCSEL), a 2 μm output aperture is designed to guarantee the single mode output. The effects of different mesa sizes on the lattice temperature, the output power and the voltage are simulated under the condition of continuous working at room temperature, to obtain the optimum process parameters of mesa. It is obtained by results of the crosslight simulation software that the sizes of mesa radius are between 9.5 to 12.5 μm, which cannot only obtain the maximum output power, but also improve the heat dissipation of the device. Project supported by the Beijing Municipal Eduaction Commission (No. PXM2016_014204_500018) and the Construction of Scientific and Technological Innovation Service Ability in 2017 (No. PXM2017_014204_500034).

  1. Dry etching characteristics of GaN for blue/green light-emitting diode fabrication

    International Nuclear Information System (INIS)

    Baik, K.H.; Pearton, S.J.

    2009-01-01

    The etch rates, surface morphology and sidewall profiles of features formed in GaN/InGaN/AlGaN multiple quantum well light-emitting diodes by Cl 2 -based dry etching are reported. The chlorine provides an enhancement in etch rate of over a factor of 40 relative to the physical etching provided by Ar and the etching is reactant-limited until chlorine gas flow rates of at least 50 standard cubic centimeters per minute. Mesa sidewall profile angle control is possible using a combination of Cl 2 /Ar plasma chemistry and SiO 2 mask. N-face GaN is found to etch faster than Ga-face surfaces under the same conditions. Patterning of the sapphire substrate for improved light extraction is also possible using the same plasma chemistry

  2. SPECTRAL CHARACTERISTICS OF MID-INFRARED LIGHT-EMITTING DIODES BASED ON InAs (Sb,P

    Directory of Open Access Journals (Sweden)

    N. K. Zhumashev

    2016-01-01

    Full Text Available Subject of Study. We consider spectral characteristics of mid-infrared light-emitting diodes with heterostructures based on InAs(Sb,P emitting at T=300 K in the wavelength range 3.4–4.1 micrometers. The aim of the study was to search for the ways of increasing the diode efficiency. Methods. The heterostructures were grown from metal-organic chemical compounds with the use of vapor-phase epitaxial technique. The spectra were recorded under pulse excitation with the use of computer-controlled installation employing MDR-23 grating monochromator and a lock-in amplifier. InSb photodiode was used as a detector. Comparative study of electroluminescence spectra of the diodes was carried out at the temperatures equal to 300 K and 77 K. We compared the obtained data with the calculation results of the band diagrams of the heterostructures. Main Results. As a result of comparative study of the electroluminescence spectra of the diodes recorded at 300 K and 77 K we have established that increasing of their efficiency is hindered by substantial influence of Auger recombination. For the first time at 77 К we have observed the effect of stimulated emission from InAsSb active layer in light-emitting structures made of InAs/InAsSb/InAsSbP. For heterostructures with quantum wells InAs/(InAs/InAsSb/InAsSbP we have found out that at 77 К the carrier recombination occurs outside quantum wells, which points out to the insufficient carrier localization in the active layer. Thus, we have shown that the efficiency of mid-infrared light-emitting diodes based on InAs(Sb,P can be increased via suppression of Auger-recombination and improvement of carrier localization in the active region. Practical Relevance. The results of the study can be used for development of heterostructures for mid-infrared light-emitting diodes.

  3. Emission Characteristics of Organic Light-Emitting Diodes and Organic Thin-Films with Planar and Corrugated Structures

    Directory of Open Access Journals (Sweden)

    Mao-Kuo Wei

    2010-04-01

    Full Text Available In this paper, we review the emission characteristics from organic light-emitting diodes (OLEDs and organic molecular thin films with planar and corrugated structures. In a planar thin film structure, light emission from OLEDs was strongly influenced by the interference effect. With suitable design of microcavity structure and layer thicknesses adjustment, optical characteristics can be engineered to achieve high optical intensity, suitable emission wavelength, and broad viewing angles. To increase the extraction efficiency from OLEDs and organic thin-films, corrugated structure with micro- and nano-scale were applied. Microstructures can effectively redirects the waveguiding light in the substrate outside the device. For nanostructures, it is also possible to couple out the organic and plasmonic modes, not only the substrate mode.

  4. Steady-state characteristics of lateral p-n junction vertical-cavity surface-emitting lasers

    Science.gov (United States)

    Ryzhii, V.; Tsutsui, N.; Khmyrova, I.; Ikegami, T.; Vaccaro, P. O.; Taniyama, H.; Aida, T.

    2001-09-01

    We developed an analytical device model for lateral p-n junction vertical-cavity surface-emitting lasers (LJVCSELs) with a quantum well active region. The model takes into account the features of the carrier injection, transport, and recombination in LJVCSELs as well as the features of the photon propagation in the cavity. This model is used for the calculation and analysis of the LJVCSEL steady-state characteristics. It is shown that the localization of the injected electrons primarily near the p-n junction and the reabsorption of lateral propagating photons significantly effects the LJVCSELs performance, in particular, the LJVCSEL threshold current and power-current characteristics. The reincarnation of electrons and holes due to the reabsorption of lateral propagating photons can substantially decrease the threshold current.

  5. Device characteristics of organic light-emitting diodes based on electronic structure of the Ba-doped Alq3 layer.

    Science.gov (United States)

    Lim, Jong Tae; Kim, Kyung Nam; Yeom, Geun Young

    2009-12-01

    Organic light-emitting diodes (OLEDs) with a Ba-doped tris(8-quinolinolato)aluminum(III) (Alq3) layer were fabricated to reduce the barrier height for electron injection and to improve the electron conductivity. In the OLED consisting of glass/ITO/4,4',4"-tris[2-naphthylphenyl-1-phenylamino]triphenylamine (2-TNATA, 30 nm)/4,4'-bis[N-(1-napthyl)-N-phenyl-amino]-biphenyl (NPB, 18 nm)/Alq3 (42 nm)/Ba-doped Alq3 (20 nm, x%: x = 0, 10, 25, and 50)/Al (100 nm), the device with the Alq3 layer doped with 10% Ba showed the highest light out-coupling characteristic. However, as the Ba dopant concentration was increased from 25% to 50%, this device characteristic was largely reduced. The characteristics of these devices were interpreted on the basis of the chemical reaction between Ba and Alq3 and the electron injection property by analyzing the electronic structure of the Ba-doped Alq3 layer. At a low Ba doping of 10%, mainly the Alq3 radical anion species was formed. In addition, the barrier height for electron injection in this layer was decreased to 0.6 eV, when compared to the pristine Alq3 layer. At a high Ba doping of 50%, the Alq3 molecules were severely decomposed. When the Ba dopant concentration was changed, the light-emitting characteristics of the devices were well coincided with the formation mechanism of Alq3 radical anion and Alq3 decomposition species.

  6. Calculation of energetic characteristics of C-14 emitted from Beloyarsk nuclear power plant plume with fast neutron reactor

    Science.gov (United States)

    Kolotkov, Gennady A.; Penin, Sergei

    2017-11-01

    The paper examines an update of comparative analysis of radionuclides released into the atmosphere from Beloyarsk nuclear power plant with fast-neutron reactor for nine years in a row, from 2008 to 2016. It has been shown that the main radionuclides throw out into the atmosphere from Beloyarsk nuclear power plant are beta-active radionuclides. Based on data releases of the RPA "Typhoon", it has been conclude that radiation situation become worse insignificantly; beside on the new reactor BN-800 was put in operation in 2016. Using Spencer-Fano's equation, it was carried out the summary spectrum of emitted radionuclides. On example of Beloyarsk nuclear power plant, it was considered a question about ability of remote detection of raised radioactivity in the atmospheric radioactive plume. It has been shown that it possible to detect raised radioactivity in the emission plume from Beloyarsk nuclear power plant.

  7. Safety assessment of RF and microwave radiation emitted by the mobile telephone base station (MTBS) in Malaysia: experience and challenge

    International Nuclear Information System (INIS)

    Roha Tukimin; Rozaimah Abd Rahim; Mohamad Amirul Nizam; Mohd Yusof Mohd Ali

    2007-01-01

    Non-ionising radiation (NIR) is known to be hazardous if the amount received is excessive. It is a fact that NIR, including extremely low frequency (ELF) electromagnetic fields, radiofrequency (RF) and microwave radiation can be found almost everywhere generated by both natural and man-made source. This is due to increase in demand for telecommunication and wireless technology which is become very important and as part of our lives. However, the widespread of the relevant technology contributed more NIR man-made sources exposure to the human. Due to public concern their potential of causing such health hazard, members of public and companies approached and request NIR Group of Nuclear Malaysia to carry out surveys and safety assessments of radiofrequency and microwave radiation emitted by the mobile telephone base station (MTBS) erected near the residential area or installed on the rooftop of the commercial building. Objective of the survey was to assess the presence of radiofrequency and microwave radiation and to identify radiation level which may lead to significant personnel exposure. Findings of the survey was compared to the standard guidelines issued by Malaysian Communication and Multimedia Commission (MCMC) and International Committee on Non-Ionising Radiation Protection (ICNIRP). This paper highlights the works that had been carried out by NIR Group of Nuclear Malaysia from 1997 to 2007. We will share the experience and challenge in carried out the NIR safety assessment at mobile telephone base station. Results of the assessment work will be used to develop non-ionising radiation database for future reference in Malaysia. (Author)

  8. Radiation resistant characteristics of optical fibers

    International Nuclear Information System (INIS)

    Nakasuji, Masaaki; Tanaka, Gotaro; Watanabe, Minoru; Kyodo, Tomohisa; Mukunashi, Hiroaki

    1983-01-01

    It is required to develop the optical fibers with good radiation resistivity because the fibers cause the increase of transmission loss due to glass colouring when they are used under the presence of radiation such as γ-ray. Generally, it is known that SI (step index) fibers are more resistive to radiation than GI (graded index) fibers. However, since a wide band can not be obtained with SI fibers, the development of radiation resistive GI optical fibers is desirable. In this report, the production for trial of the GI fibers of fluorine-doped silica core, the examination of radiation effect on their optical transmission loss by exposing them to γ-ray, thermal and fast neutron beams and also of mechanical strength are described. The GI fibers of fluorine-doped silica core show better radiation resistivity than Ge-doped ones. The B- and F-doped GI fibers show small increase of loss due to γ-ray, but large increase of loss due to thermal neutron beam. This is supposed to be caused by the far greater neutron absorption cross-section of boron than that of other elements. Significant increase of loss was not recognized when 14 MeV fast neutrons (8.6 x 10 4 n/cm 2 .s) were applied by 1.8 x 10 9 n/cm 2 . It was found that ETFE-covered fiber cores generated fluorine-containing gas due to γ irradiation, and the strength was remarkably lowered, but the lowering of strength can be prevented by adding titanium-white to the covering material. (Wakatsuki, Y.)

  9. Development of computational pregnant female and fetus models and assessment of radiation dose from positron-emitting tracers

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Tianwu [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland); University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Southern Denmark, Department of Nuclear Medicine, Odense (Denmark)

    2016-12-15

    Molecular imaging using PET and hybrid (PET/CT and PET/MR) modalities nowadays plays a pivotal role in the clinical setting for diagnosis and staging, treatment response monitoring, and radiation therapy treatment planning of a wide range of oncologic malignancies. The developing embryo/fetus presents a high sensitivity to ionizing radiation. Therefore, estimation of the radiation dose delivered to the embryo/fetus and pregnant patients from PET examinations to assess potential radiation risks is highly praised. We constructed eight embryo/fetus models at various gestation periods with 25 identified tissues according to reference data recommended by the ICRP publication 89 representing the anatomy of the developing embryo/fetus. The developed embryo/fetus models were integrated into realistic anthropomorphic computational phantoms of the pregnant female and used for estimating, using Monte Carlo calculations, S-values of common positron-emitting radionuclides, organ absorbed dose, and effective dose of a number of positron-emitting labeled radiotracers. The absorbed dose is nonuniformly distributed in the fetus. The absorbed dose of the kidney and liver of the 8-week-old fetus are about 47.45 % and 44.76 % higher than the average absorbed dose of the fetal total body for all investigated radiotracers. For {sup 18}F-FDG, the fetal effective doses are 2.90E-02, 3.09E-02, 1.79E-02, 1.59E-02, 1.47E-02, 1.40E-02, 1.37E-02, and 1.27E-02 mSv/MBq at the 8th, 10th, 15th, 20th, 25th, 30th, 35th, and 38th weeks of gestation, respectively. The developed pregnant female/fetus models matching the ICRP reference data can be exploited by dedicated software packages for internal and external dose calculations. The generated S-values will be useful to produce new standardized dose estimates to pregnant patients and embryo/fetus from a variety of positron-emitting labeled radiotracers. (orig.)

  10. Radiation oncologists in 2000: demographic, professional, and practice characteristics

    International Nuclear Information System (INIS)

    Cypel, Yasmin; Sunshine, Jonathan H.; Schepps, Barbara

    2002-01-01

    Purpose: To describe the demographic, professional, and practice characteristics of radiation oncologists, emphasizing comparisons to data from a similar 1995 Survey. Methods and Materials: In spring 2000, we surveyed 603 randomly selected radiation oncologists by mail, using a one-page questionnaire - 455 responded. We weighted responses to make answers representative of all radiation oncologists in the United States. Results: Approximately 45% of post-training, professionally active, radiation oncologists were <45 years old and 22% were women. Forty-two percent of radiation oncologists in training were women. Thirty-three percent of radiation-oncology-only practices were solo practices. The greatest percentage of post-training, professionally active, radiation oncologists were in nonacademic private radiation oncology practices. Fifty-three percent of post-training, professionally active, radiation oncologists reported that their workload was about right. Eighteen percent of individuals 60-64 years old and approximately two-thirds of those ≥65 years old were not working (retired). The full-time equivalency of those aged 55-74 fell by 12 percentage points between 1995 and 2000. Conclusions: Most demographic, professional, and practice characteristics remained relatively constant between 1995 and 2000, with the exception of work status patterns. Radiation oncologists reported a more balanced workload than that reported by diagnostic radiologists. The surplus of radiation oncologists, which was predicted in the mid-1990s, was not demonstrated

  11. Influence of radiation-dose pattern from inhaled beta--gamma-emitting radionuclides on canine peripheral lymphocytes

    International Nuclear Information System (INIS)

    Jones, R.K.; Boecker, B.B.; Pickrell, J.A.; Hobbs, C.H.; McClellan, R.O.

    1976-01-01

    As part of studies assess the biological hazards associated with inhaled radionuclides, periodic hematologic evaluations were performed on beagle dogs given a single nose-only exposure to aerosols of beta--gamma-emitting isotopes. The physical form and specific radionuclides selected produced radiation-dose patterns representative of those which might be encountered in the event of human accidental exposures. Dogs received graded lung burdens of either 90 Y, 91 Y, 144 Ce, or 90 Sr, each in fused clay. Differences in the effective half-lives of these radionuclides resulted in a spectrum of cumulative radiation doses to lung delivered at a variety of dose rates. Since the form in which the radionuclides were inhaled was relatively insoluble, the lung and intrathoracic tissues represented the primary recipient of the dose. Regardless of the effective half-life of radionuclide retention, a dose-related depression of peripheral lymphocytes was observed at various times after inhalation exposure. The time at which maximum depression and subsequent recovery occurred, however, was most directly related to the effective half-life of the radionuclide. Of special interest was the persistence of lymphopenia through 2 1 / 2 years after exposure to 144 Ce and 90 Sr in fused clay where, other than tracheobronchial lymph nodes, the lymphoid tissue received very little radiation dose. The possible mechanisms responsible for lymphocyte depression from these various radiation-dose patterns are discussed

  12. [The spectrogram characteristics of organic blue-emissive light-emitting excitated YAG : Ce phosphor].

    Science.gov (United States)

    Xi, Jian-Fei; Zhang, Fang-Hui; Mu, Qiang; Zhang, Mai-Li

    2011-09-01

    It is demonstrated that the panchromatic luminescence devices with organic blue-emissive light-emitting was fabricated. This technique used down conversion, which was already popular in inorganic power LEDs to obtain white light emission. A blue OLED device with a configuration of ITO/2T-NATA (30 nm)/AND : TBPe (50 Wt%, 40 nm)/Alq3 (100 nm)/LiF(1 nm)/Al(100 nm) was prepared via vacuum deposition process, and then coated with YAG : Ce phosphor layers of different thicknesses to obtain a controllable and uniform shape while the CIE coordinates were fine tuned. This development not only decreased steps of technics and degree of difficulty, but also applied the mature technology of phosphor. The results showed that steady spectrogram was obtained in the devices with phosphor, with a best performance of a maximum luminance of 13 840 cd x m(-2) which was about 2 times of that of the devices without phosphor; a maximum current efficiency of 17.3 cd x A(-1) was increased more two times more than the devices without phosphor. The emission spectrum could be adjusted by varying the concentration and thickness of the phosphor layers. Absoulte spectrogram of devices was in direct proportion with different driving current corresponding.

  13. Radiative characteristics of the Chelyabinsk superbolide

    Science.gov (United States)

    Yanagisawa, Masahisa

    2015-12-01

    On Feb. 15, 2013, a meteoroid with a size of about 19 m plunged into the terrestrial atmosphere at 19 km s-1 and burst at an altitude of about 30 km over the city of Chelyabinsk, Russia. Here we present light curves for the bolide in the red, green, and blue color bands, derived from an analysis of a video that was recorded by a dashboard camera and released on the Internet. Our results demonstrate that the bolide was blue-green in color, which is inconsistent with the Planck spectrum before the meteoroid began to fragment. Fragmentation triggered a flare-up of the bolide and 90% of its radiation energy at optical wavelengths was released within a period of about 2 s after that. During the same period, the brightness ratios among the three bands became consistent with 4000 K blackbody radiation. Based on the peak luminosity, a surface area of several square kilometers would be required for a 4000 K blackbody. It is considered that the radiation source of the bolide was an elongated cloud of vapor and debris produced through severe fragmentation of the meteoroid.

  14. Generation of tunable narrow-band surface-emitted terahertz radiation in periodically poled lithium niobate.

    Science.gov (United States)

    Weiss, C; Torosyan, G; Avetisyan, Y; Beigang, R

    2001-04-15

    Generation of tunable narrow-band terahertz (THz) radiation perpendicular to the surface of periodically poled lithium niobate by optical rectification of femtosecond pulses is reported. The generated THz radiation can be tuned by use of different poling periods and different observation angles, limited only by the available bandwidth of the pump pulse. Typical bandwidths were 50-100 GHz, depending on the collection angle and the number of periods involved.

  15. Phase Radiation Characteristics of an Open-Ended Circular Waveguide

    DEFF Research Database (Denmark)

    Shishkova, A.V.; Pivnenko, Sergiy; Kim, O.S.

    2002-01-01

    Analytic expressions for phase radiation characteristics of a semi-infinite open-ended circular waveguide regardless of its aperture size and operating frequency have been obtained making use of the rigorous Weinstein's theory. The analysis of phase radiation patterns has been carried out...... for the dominant mode (TE11) as well as for the high order modes TM01 and TE01, both for a single and multimode propagation. The measurement of radiation characteristics of an open-ended circular waveguide has been carried out at the DTU-ESA Spherical Near-Field Antenna Test Facility. It is shown...

  16. Characteristics of ITO electrode grown by linear facing target sputtering with ladder type magnetic arrangement for organic light emitting diodes

    International Nuclear Information System (INIS)

    Jeong, Jin-A; Kim, Han-Ki; Lee, Jae-Young; Lee, Jung-Hwan; Bae, Hyo-Dae; Tak, Yoon-Heung

    2009-01-01

    The preparation and characteristics of indium tin oxide (ITO) electrodes grown using a specially designed linear facing target sputtering (LFTS) system with a ladder type magnet arrangement for organic light emitting diodes (OLED) are described. It was found that the electrical and optical properties of the ITO electrode were critically dependent on the Ar/O 2 flow ratio, while its structural and surface properties remained fairly constant regardless of the Ar/O 2 flow ratio, due to the low substrate temperature during the plasma damage-free sputtering. Under the optimized conditions, we obtained an ITO electrode with the lowest sheet resistance of 39.4 Ω/sq and high transmittance of 90.1% (550 nm wavelength) at room temperature. This suggests that LFTS is a promising low temperature and plasma damage free sputtering technology for preparing high-quality ITO electrodes for OLEDs and flexible OLEDs at room temperature.

  17. Characteristics of InGaN-Based Light-Emitting Diodes on Patterned Sapphire Substrates with Various Pattern Heights

    Directory of Open Access Journals (Sweden)

    Sheng-Fu Yu

    2012-01-01

    Full Text Available The optical and electrical characteristics of InGaN-based blue light-emitting diodes (LEDs grown on patterned sapphire substrates (PSSs with different pattern heights and on planar sapphire by atmospheric-pressure metal-organic chemical vapor deposition were investigated. Compared with planar sapphire, it was found that the LED electroluminescence intensity is significantly enhanced on PSSs with pattern heights of 0.5 (21%, 1.1 (57%, 1.5 (81%, and 1.9 (91% μm at an injected current of 20 mA. The increased light intensity exhibits the same trend in a TracePro simulation. In addition, it was also found that the level of leakage current depends on the density of V-shape defects, which were measured by scanning electron microscopy.

  18. The baffle influence on sound radiation characteristics of a plate

    Directory of Open Access Journals (Sweden)

    Bao Liu

    2017-01-01

    Full Text Available The acoustic radiation characteristics of the baffle plates and unbaffle plates are calculated and compared by single-layer potential and double-layer potential. Based on the boundary integral equation, the sound pressure integral equation of the baffle and the baffle are deduced respectively. According to the boundary compatibility condition, the sound pressure and the vibration velocity of the plates are obtained. Further, the dynamic equation of the structure is substituted into the vibration equation in the form of the baffle plate and the baffle plate. The sound pressure difference and the displacement of a plate surface are in the form of the vibration mode superposition and the acoustic radiation impedance of the double integral form is obtained, which determines vibration mode coefficient and sound radiation parameters. The effect of the baffle on the acoustic radiation characteristics of the thin plate is analyzed by comparing the acoustic radiation parameters with the simple and simple rectangular plate in water.

  19. Monte Carlo simulation of radiative transfer in scattering, emitting, absorbing slab with gradient index

    International Nuclear Information System (INIS)

    Huang Yong; Liang Xingang; Xia Xinlin

    2005-01-01

    The Monte Carlo method is used to simulate the thermal emission of absorbing-emitting-scattering slab with gradient index. Three Monte Carlo ray-tracing strategies are considered. The first strategy is keeping the real distribution of the refractive index and to trace bundles in a curve route. The second strategy is discretizing the slab into sub-layers, each having constant refractive index. The bundle is traced in a straight route in each sub-layer and the reflection at the inner interface is taken into account. The third strategy is similar to the second one but only the total reflection at the inner interface is computed. Little difference is observed among the results of apparent thermal emission by these three different Monte Carlo ray tracing strategies. The results also show that the apparent hemispherical emissivity non-monotonously varies with increasing optical thickness of the slab with strong scattering gradient index. Many parameters can influence the apparent thermal emission greatly

  20. Reprint of 'Evaluation of Scattered Radiation Emitted From X-ray Security Scanners on Occupational Dose to Airport Personnel'

    Science.gov (United States)

    Dalah, Entesar; Fakhry, Angham; Mukhtar, Asma; Al Salti, Farah; Bader, May; Khouri, Sara; Al-Zahmi, Reem

    2017-11-01

    Based on security issues and regulations airports are provided with luggage cargo scanners. These scanners utilize ionizing radiation that in principle present health risks toward humans. The study aims to investigate the amount of backscatter produced by passenger luggage and cargo toward airport personnel who are located at different distances from the scanners. To approach our investigation a Thermo Electron Radeye-G probe was used to quantify the backscattered radiation measured in terms of dose-rate emitted from airport scanners, Measurements were taken at the entrance and exit positions of the X-ray tunnel at three different distances (0, 50, and 100 cm) for two different scanners; both scanners include shielding curtains that reduce scattered radiation. Correlation was demonstrated using the Pearson coefficient test. Measurements confirmed an inverse relationship between dose rate and distance. An estimated occupational accumulative dose of 0.88 mSv/y, and 2.04 mSv/y were obtained for personnel working in inspection of carry-on, and cargo, respectively. Findings confirm that the projected dose of security and engineering staff are being well within dose limits.

  1. Electromagnetic radiation emitted by a plasma produced in air by laser pulses with lambda = 10.6 μm

    International Nuclear Information System (INIS)

    Danilychev, V.A.; Zvorykin, V.D.; Kholin, I.V.; Chugunov, A.Y.

    1981-01-01

    The spectrum, brightness, and energy have been measured for the electromagnetic radiation emitted by a plasma produced in air near a solid surface by pulses from a high-power CO 2 laser. The air pressure was varied over the range p 0 = 0.1--760 torr, and the laser power density was varied over the range q = 5 x 10 6 --10 8 W/cm 2 . At p 0 > or approx. =2--5 torr the radiation properties of the plasma are determined by a laser-beam absorption wave which arises in the gas. The maximum brightness temperature, T/sub b/approx. =50 000 K (lambda = 400 +- 20 nm), is reached at p 0 = 25 torr. The emission spectrum is quite different from an equilibrium spectrum, consisting primarily of NII, OII, and NIII lines. The total energy radiation by the plasma in the wavelength interval 360--2600 nm into a solid angle of 4π sr reaches 2.3% of the laser pulse energy

  2. Investigation on diagnostic techniques of X-ray radiation characteristic from slit target

    International Nuclear Information System (INIS)

    Cheng Jinxiu; Miao Wenyong; Sun Kexu; Wang Hongbin; Cao Leifeng; Yang Jiamin; Chen Zhenglin

    2001-01-01

    On the Xingguang-II facility, X-ray transport process in a cavity target was simulated in a long cylindrical cavity with slits. High temporally and spatially resolved Microchannel Plate (MCP) gated X-ray picosecond frame camera and soft X-ray steak camera were used to investigate the temporal and spatial distribution of the soft X-ray emitted from the cavity wall through the slit. X-ray transport velocity, X-ray emission time and amount of intensity decay was obtained. X-ray CCD pinhole transmission grating spectrometer was used to investigate the spectrum change of the emitted X-ray versus its location. The change characteristic of the spectrum of X-ray absorbed and emitted again and again in transport was obtained. X-ray diodes and Dante spectrometer were used to measure X-ray flux and radiation temperature in the slit, the source and the transport end, respectively. The typical results in the experiment were given. A brief and essential analysis and discussion were made

  3. Palliative treatment with radiation-emitting metallic stents in unresectable Bismuth type III or IV hilar cholangiocarcinoma.

    Science.gov (United States)

    Lu, Jian; Guo, Jin-He; Zhu, Hai-Dong; Zhu, Guang-Yu; Wang, Yong; Zhang, Qi; Chen, Li; Wang, Chao; Pan, Tian-Fan; Teng, Gao-Jun

    2017-01-01

    The emerging data for stenting in combination with brachytherapy in unresectable hilar cholangiocarcinoma are encouraging. The aim of this study was to evaluate the efficacy and safety of radiation-emitting metallic stents (REMS) for unresectable Bismuth type III or IV hilar cholangiocarcinoma. Consecutive patients who underwent percutaneous placement with REMS or uncovered self-expandable metallic stent (SEMS) for unresectable Bismuth type III or IV hilar cholangiocarcinoma between September 2011 and April 2016 were identified into this retrospective study. Data on patient demographics and overall survival, functional success, stent patency and complications were collected at the authors' hospital. A total of 59 patients were included: 33 (55.9%) in the REMS group and 26 (44.1%) in the SEMS group. The median overall survival was 338 days in the REMS group and 141 days in the SEMS group (philar cholangiocarcinoma, and seems to prolong survival as well as patency of stent in these patients.

  4. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

    International Nuclear Information System (INIS)

    Kulkarni, A.; Bak, M. S.; Ha, S.; Joshirao, P.; Manchanda, V.; Kim, T.

    2015-01-01

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO 3 ) 4 ⋅ 5H 2 O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories

  5. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

    Science.gov (United States)

    Kulkarni, A.; Ha, S.; Joshirao, P.; Manchanda, V.; Bak, M. S.; Kim, T.

    2015-06-01

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO3)4 ṡ 5H2O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

  6. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, A.; Bak, M. S., E-mail: tkim@skku.edu, E-mail: moonsoo@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Ha, S. [SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Joshirao, P.; Manchanda, V. [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, T., E-mail: tkim@skku.edu, E-mail: moonsoo@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-06-15

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO{sub 3}){sub 4} ⋅ 5H{sub 2}O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

  7. A Numerical Simulation for Prediction of Infrared Radiation Emitted from Plain Surfaces with Different Geometries

    Directory of Open Access Journals (Sweden)

    Vakilabadi K.A.

    2017-08-01

    Full Text Available In this paper, infrared radiation exiting plain surfaces with different geometries is numerically simulated. Surfaces under consideration are assumed to have steady uniform heat generation inside. Moreover, the boundaries of the surfaces are considered to be at the surroundings temperature. Infrared radiation is calculated based on the temperature profile determined for the surface. The temperature profile of the surface is determined assuming the two dimensional heat conduction equations to govern the problem. The physical domain is transformed into the appropriate computational domain and the governing equation is mapped into the suitable forms in the new coordinate system of variables. After that the temperature profile of the surface is computed, the infrared radiation distribution of the surface is evaluated based on the equations given in the manuscript. The temperature profile as well as the IR images are given in the results section. It is concluded that the maximum value of infrared radiation of the surface occurs at the center. Moreover, it is concluded that among surfaces with equal areas, the one having the largest perimeter has the least value of IR at its center.

  8. Time-dependent radiation characteristics of Nannochloropsis oculata during batch culture

    International Nuclear Information System (INIS)

    Heng, Ri-Liang; Pilon, Laurent

    2014-01-01

    This paper reports the temporal evolution of the scattering and absorbing cross-sections of marine eustigmatophycease Nannochloropsis oculata grown in a flat-plate photobioreactor (PBR). The PBR was operated in batch mode under constant irradiance of 7500 or 10,000 lux provided by red LEDs emitting at 630 nm. The radiation characteristics between 400 and 750 nm and pigment concentrations of N. oculata were measured systematically every 24 h for up to 18 days. They were found to vary significantly with time in response to changes in light and nutrients availability. The results were interpreted in terms of up- and down-regulations of pigments and other intracellular components. Finally, this study demonstrates that the light transfer in the PBR could be predicted using constant radiation characteristics measured during the exponential growth phase with reasonable accuracy provided that the cultures were not nitrogen limited. During nitrogen starvation, pigment concentrations decreased and radiation characteristics evolved rapidly. These results will be useful in the design and operation of PBRs for biofuel production at both small and large scales. - Highlights: • N. oculata cultures were grown in batch mode under two different irradiances. • Temporal evolution of their absorption and scattering cross-sections was reported. • The effects of photoacclimation and nitrogen starvation were quantified. • Results were interpreted in terms of regulation of cell constituents

  9. Structural effects of a light emitting copolymer having perylene moieties in the side chain on the electroluminescent characteristics

    International Nuclear Information System (INIS)

    Lee, Chang Ho; Ryu, Seung Hoon; Jang, Hee Dong; Oh, Se Young

    2004-01-01

    We have synthesized a novel side chain light emitting copolymer. The side chain light emitting copolymer has a perylene moiety as an emitting unit and methylmethacrylate (MMA) as a spacer to decrease the concentration quenching of light emitting site in the polymer intrachain. These polymers are very soluble in most organic solvents such as monochlorobenzene, tetrahydrofuran, chloroform and benzene. The single-layered electroluminescent (EL) device consisting of ITO/carrier transporting copolymer and light emitting copolymer/Al was manufactured. The carrier transporting copolymer has triphenylamine moiety as a hole transporting unit and triazine moiety as an electron transporting unit in the polymer side chain. This device exhibits maximum external quantum efficiency when the MMA contents of light emitting copolymer is 30 wt.%. In particular, the device emits more blue light as MMA contents increase

  10. Radiation characteristics of GD-2 fuel

    International Nuclear Information System (INIS)

    Chrapciak, V.

    2008-01-01

    The assembly WWER-440 type Gd-2 has radial profile of enrichment and has 6 pins with Gd 2 O 3 . The maximal enrichment is 4.4%. Some analyses are done for assembly with flat enrichment (4.4%) and without Gd 2 O 3 . In this article are compared some characteristics (decay heat, some nuclide concentration, photon and gamma sources) for real Gd-2 assembly and for flat 4.4% assembly. The TRITON module (in SCALE 5.1) was used. (Author)

  11. SiC detectors to monitor ionizing radiations emitted from nuclear events and plasmas

    Science.gov (United States)

    Torrisi, L.; Cannavò, A.

    2016-09-01

    Silicon Carbide (SiC) semiconductor detectors are increasingly employed in Nuclear Physics for their advantages with respect to traditional silicon (Si). Such detectors show an energy resolution, charge mobility, response velocity and detection efficiency similar to Si detectors. However, the higher band gap (3.26 eV), the lower leakage current (∼10 pA) maintained also at room temperature, the higher radiation hardness and the higher density with respect to Si represent some indisputable advantages characterizing such detectors. The devices can be employed at high temperatures, at high absorbed doses and in the case of high visible light intensities, for example, in plasma, for limited exposition times without damage. Generally SiC Schottky diodes are employed in reverse polarization with an active region depth of the order of 100 µm, purity below 1014 cm-3 and an active area lower than 1 cm2. Measurements in the regime of proportionality with the radiation energy released in the active region and measurements in time-of-flight configuration are employed for nuclear emission events produced at both low and high fluences. Alpha spectra demonstrated an energy resolution of about 1.3% at 5.8 MeV. Radiation emission from laser-generated plasma can be monitored in terms of detected photons, electrons and ions, using the laser pulse as a start signal and the radiation detection as a stop signal, enabling to measure the ion velocity by knowing the target-detector flight distance. SiC spectra acquired in the Messina University laboratories using radioactive ion sources and at the PALS laboratory facility in Prague (Czech Republic) are presented. A preliminary study of the use of SiC detectors, embedded in a water equivalent polymer, as a dosimeter is presented and discussed.

  12. The pollution characteristics of odor, volatile organochlorinated compounds and polycyclic aromatic hydrocarbons emitted from plastic waste recycling plants.

    Science.gov (United States)

    Tsai, Chung-Jung; Chen, Mei-Lien; Chang, Keng-Fu; Chang, Fu-Kuei; Mao, I-Fang

    2009-02-01

    Plastic waste treatment trends toward recycling in many countries; however, the melting process in the facilities which adopt material recycling method for treating plastic waste may emit toxicants and cause sensory annoyance. The objectives of this study were to analyze the pollution characteristics of the emissions from the plastic waste recycling plants, particularly in harmful volatile organochlorinated compounds, polycyclic aromatic hydrocarbons (PAHs), odor levels and critical odorants. Ten large recycling plants were selected for analysis of odor concentration (OC), volatile organic compounds (VOCs) and PAHs inside and outside the plants using olfactometry, gas chromatography-mass spectrometry and high performance liquid chromatography-fluorescence detector, respectively. The olfactometric results showed that the melting processes used for treating polyethylene/polypropylene (PE/PP) and polyvinyl chloride (PVC) plastic waste significantly produced malodor, and the odor levels at downwind boundaries were 100-229 OC, which all exceeded Taiwan's EPA standard of 50 OC. Toluene, ethylbenzene, 4-methyl-2-pentanone, methyl methacrylate and acrolein accounted for most odors compared to numerous VOCs. Sixteen organochlorinated compounds were measured in the ambient air emitted from the PVC plastic waste recycling plant and total concentrations were 245-553 microg m(-3); most were vinyl chloride, chloroform and trichloroethylene. Concentrations of PAHs inside the PE/PP plant were 8.97-252.16 ng m(-3), in which the maximum level were 20-fold higher than the levels detected from boundaries. Most of these recycling plants simply used filter to treat the melting fumes, and this could not efficiently eliminate the gaseous compounds and malodor. Improved exhaust air pollution control were strongly recommended in these industries.

  13. Radiational and energetic characteristics of diatomic molecules (data base)

    International Nuclear Information System (INIS)

    Kuznetsova, L.A.; Pazyuk, E.A.; Stolyarov, A.V.

    1993-01-01

    Data base on radiational and energetic characteristics of diatomic molecules was created. The base consists of two parts: reference system and recommended data system. The reference system contains the information about studies of radiational and energetic parameters of more than 1500 electronic states and 1700 electron transfers for ∼ 350 diatomic molecules and their ions. The base bibliography includes ∼ 3000 publications. 11 refs., 1 figs

  14. INTERACTION OF LASER RADIATION WITH MATTER: Influence of a target on operation of a pulsed CO2 laser emitting microsecond pulses

    Science.gov (United States)

    Baranov, V. Yu; Dolgov, V. A.; Malyuta, D. D.; Mezhevov, V. S.; Semak, V. V.

    1987-12-01

    The profile of pulses emitted by a TEA CO2 laser with an unstable resonator changed as a result of interaction of laser radiation with the surface of a metal in the presence of a breakdown plasma. This influence of a target on laser operation and its possible applications in laser processing of materials are analyzed.

  15. Characteristics of particulate-bound polycyclic aromatic hydrocarbons emitted from industrial grade biomass boilers.

    Science.gov (United States)

    Yang, Xiaoyang; Geng, Chunmei; Sun, Xuesong; Yang, Wen; Wang, Xinhua; Chen, Jianhua

    2016-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic or mutagenic and are important toxic pollutants in the flue gas of boilers. Two industrial grade biomass boilers were selected to investigate the characteristics of particulate-bound PAHs: one biomass boiler retro-fitted from an oil boiler (BB1) and one specially designed (BB2) biomass boiler. One coal-fired boiler was also selected for comparison. By using a dilution tunnel system, particulate samples from boilers were collected and 10 PAH species were analyzed by gas chromatography-mass spectrometry (GC-MS). The total emission factors (EFs) of PAHs ranged from 0.0064 to 0.0380 mg/kg, with an average of 0.0225 mg/kg, for the biomass boiler emission samples. The total PAH EFs for the tested coal-fired boiler were 1.8 times lower than the average value of the biomass boilers. The PAH diagnostic ratios for wood pellets and straw pellets were similar. The ratio of indeno(1,2,3-cd)pyrene/[indeno(1,2,3-cd)pyrene+benzo(g,h,i)perylene] for the two biomass boilers was lower than those of the reference data for other burning devices, which can probably be used as an indicator to distinguish the emission of biomass boilers from that of industrial coal-fired boilers and residential stoves. The toxic potential of the emission from wood pellet burning was higher than that from straw pellet burning, however both of them were much lower than residential stove exhausts. Copyright © 2015. Published by Elsevier B.V.

  16. Fabrication of a white-light-emitting organic LED adopting the two-wavelength method by using new DPVBi derivatives and an analysis of its characteristics

    International Nuclear Information System (INIS)

    Oh, Hwan-Sool; Cho, Jae-Young; Yoon, Seok-Beom; Kang, Myung-Koo

    2004-01-01

    The white-light emission of the two-wavelength method was represented by the processes of compounding new DPVBi derivatives, methyl-DPVT and nitro-DPVT, from the blue-emitting material DPVBi, after which blue light was emitted from nitro-DPVT and orange light was emitted by doping methyl-DPVT as a host material with Rubrene as a guest material. The basic structure of the fabricated organic white-light-emitting organic light-emitting device (OLED) was glass/ITO/NPB(150 A)/nitro-DPVT(100 A)/methyl-DPVT:Rubrene [2.0 wt%]/BCP(70 A)/Alq 3 (150 A)/Al(600 A).We evaluated the characteristics by varying the thickness of the methyl-DPVT:Rubrene layer from 100 A to 90 A to 80 A to 60 A and obtained nearly-pure white light in the Commission Internationale de l'Eclairage (CIE) coordinates (0.3175, 0.3338) in the case where the methyl-DPVT:Rubrene layer was 60-A thick. It turned out that the device remained stable against voltage changes, the turn-on voltage was 3.5 V, the light-emitting turn-on voltage was 4 V, and the external quantum efficiency was more than 0.5 % for all injection currents.

  17. Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran.

    Science.gov (United States)

    Mortazavi, Seyed Mohammad Javad; Zarei, Samira; Taheri, Mohammad; Tajbakhsh, Saeed; Mortazavi, Seyed Alireza; Ranjbar, Sahar; Momeni, Fatemeh; Masoomi, Samaneh; Ansari, Leila; Movahedi, Mohammad Mehdi; Taeb, Shahram; Zarei, Sina; Haghani, Masood

    2017-04-01

    Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium ( S. typhimurium ), Staphylococcus aureus , and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD 0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

  18. Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Javad Mortazavi

    2017-04-01

    Full Text Available Background: Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. Objective: To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium (S. typhimurium, Staphylococcus aureus, and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Methods: Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. Results: The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6 mm; it was 14.7 (SD 0.6 mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Conclusion: Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

  19. Mobile phone base station-emitted radiation does not induce phosphorylation of Hsp27.

    Science.gov (United States)

    Hirose, H; Sakuma, N; Kaji, N; Nakayama, K; Inoue, K; Sekijima, M; Nojima, T; Miyakoshi, J

    2007-02-01

    An in vitro study focusing on the effects of low-level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system was conducted to test the hypothesis that modulated RF fields act to induce phosphorylation and overexpression of heat shock protein hsp27. First, we evaluated the responses of human cells to microwave exposure at a specific absorption rate (SAR) of 80 mW/kg, which corresponds to the limit of the average whole-body SAR for general public exposure defined as a basic restriction in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Second, we investigated whether continuous wave (CW) and Wideband Code Division Multiple Access (W-CDMA) modulated signal RF fields at 2.1425 GHz induced activation or gene expression of hsp27 and other heat shock proteins (hsps). Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80 and 800 mW/kg for 2-48 h, and CW radiation at 80 mW/kg for 24 h. Human IMR-90 fibroblasts from fetal lungs were exposed to W-CDMA at 80 and 800 mW/kg for 2 or 28 h, and CW at 80 mW/kg for 28 h. Under the RF field exposure conditions described above, no significant differences in the expression levels of phosphorylated hsp27 at serine 82 (hsp27[pS82]) were observed between the test groups exposed to W-CDMA or CW signal and the sham-exposed negative controls, as evaluated immediately after the exposure periods by bead-based multiplex assays. Moreover, no noticeable differences in the gene expression of hsps were observed between the test groups and the negative controls by DNA Chip analysis. Our results confirm that exposure to low-level RF field up to 800 mW/kg does not induce phosphorylation of hsp27 or expression of hsp gene family.

  20. Soft X-ray radiation power characteristics of tungsten wire arrays on Yang accelerator

    International Nuclear Information System (INIS)

    Zhang Siqun; Ouyang Kai; Huang Xianbin; Dan Jiakun; Zhou Rongguo; Yang Liang

    2013-01-01

    A series of experiments were carried out to research the X-ray radiation characteristics of tungsten wire arrays on Yang accelerator. In those experiments, we charged the Marx generator of 60 kV, and the load current of 0.85-1.00 MA, the rise time of 75-90 ns (10%-90%). A soft X-ray scintillator powermeter which responded flatly to 50-1800 eV X-rays was used to measure the power of soft X-ray emitted from implosion plasma. In this paper, we present the measuring results of time-resolved soft X-ray radiation power, and discuss the radiation characteristics of implosion plasma by analyzing the correlations of soft X-ray radiant power and the diameter, length, wire number of the tungsten wire arrays. The optimizing wire array configuration parameters on Yang are as follows: 8 mm array diameter, 15 mm wire length, and 24 wire number. We also present the radiant power difference in radial and axial directions of the wire arrays. (authors)

  1. [Characteristics of infrared radiation of meridians and acupoints].

    Science.gov (United States)

    Zheng, Juan-Juan; Shen, Xue-Yong; Zhao, Yi

    2010-10-01

    Infrared radiation temperature and characteristics of infrared spectrum of meridians and acupoints are summarized in this article. The infrared radiant track along the running course of meridians might be a ubiquitous phenomenon of the vital activity. The high temperature bands below the meridian lines at the cuticular layer are often taken as the manifestation of the tract. It could be induced by various stimulations on acupoints with warm-needling as the best causative method. High temperature and low resistance are considered as 2 features of the acupoint zone. The adenosine-triphosphate energy metabolism of the acupoint zone is higher than the non-point zone, which indicates that essential physiological and pathological information are carried by infrared radiation temperature of acupoint and infrared spectrum of acupoint. However, it is realized that study on characteristics of infrared radiation only is far from enough to reveal the essence of meridians and acupoints. And much still remains to be done in strengthening basic studies of characteristics of infrared radiation, structure pattern of meridians and acupoints as well as volt-ampere characteristics.

  2. Radiation effects in light emitting diodes, laser diodes, photodiodes and optocouplers

    International Nuclear Information System (INIS)

    Lischka, H.; Henschel, H.; Koehn, O.; Lennartz, W.; Schmidt, H.U.

    1994-01-01

    A variety of commercially available LEDs, LDs, PDs, and optocouplers from two German manufacturers were irradiated at a flash X-ray source, a 60 Co gamma ray source, and a 14 MeV neutron generator. Light output and emission spectrum of the LEDs and LDs were measured before and after irradiation at the 60 Co source. With the PDs we measured the dark current and the photo current before and after 60 Co irradiation. Determination of the sensitivity against neutrons was made off-line. With PDs we measured the photo current induced by pulsed X-rays. The GaAs LED showed a maximum decrease of output power of 28 dB after a total gamma dose of 10 6 Gy and LDs a threshold current shift of 80% after neutron fluences of 4 - 10 14 cm -2 (1 MeV). Irradiations of PDs and APDs with 60 Co gammas up to a total dose of 10 6 Gy as well as irradiations with neutrons up to fluences of ≤ 4 - 10 14 cm -2 (1 MeV) led to significant changes of the device parameters. The main effect was a strong increase of the dark current. The consequence was a reduction of the minimum detectable light power. Optocouplers are very sensitive to ionizing radiation. Gammas as well as neutrons led to a decrease of the CTR and a change of the bandwidth up to a complete failure (after neutron irradiation). (author). 9 refs., 11 figs., 4 tabs

  3. Wideband analysis of railway catenary line radiation and new applications of its unintentional emitted signals

    Science.gov (United States)

    Heddebaut, Marc; Deniau, Virginie; Rioult, Jean

    2018-06-01

    Generally, in railway networks, dissipated energy—and its consequences in terms of noise, ballast attrition, electromagnetic interference, etc—is considered a nuisance generated by this means of transport. Therefore, most studies are carried out with the aim of reducing it. This paper takes the opposite view and considers the particular case of the irreducible electromagnetic interference generated along an electrified line, in order to propose new applications beneficial to railway operations. At a selected representative location, wideband (ranging from 10 kHz to 1 GHz) electromagnetic field measurements are performed successively during, and not during, high speed train passages. We deduce two potential applications of these unintentional signals. At low frequency, the first proposal considers energy harvesting using the received electromagnetic interference as the source. This received energy can be converted and used to DC feed low consumption sensors to be installed along the railway infrastructure. These sensors participate in monitoring infrastructure health and in making it more resilient to internal and external stresses. At higher frequencies, for the second proposal, radiation from the catenary line and train pantograph is specifically examined at a carefully selected sub-band. The results are also studied following a time–frequency analysis, to introduce a new nondestructive inspection method of the sliding contact between the catenary line and the train pantograph. Ultimately, this technique could offer a new means of monitoring the health of both the catenary line and the pantograph.

  4. The effect of electromagnetic radiation emitted by display screens on cell oxygen metabolism – in vitro studies

    Science.gov (United States)

    Henrykowska, Gabriela A.; Pacholski, Krzysztof; Śmigielski, Janusz; Rutkowski, Maciej; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

    2015-01-01

    Introduction Research studies carried out for decades have not solved the problem of the effect of electromagnetic radiation of various frequency and strength on the human organism. Due to this fact, we decided to investigate the changes taking place in human blood platelets under the effect of electromagnetic radiation (EMR) emitted by LCD monitors. Material and methods The changes of selected parameters of oxygen metabolism were measured, i.e. reactive oxygen species concentration, enzymatic activity of antioxidant defence proteins – superoxide dismutase (SOD-1) and catalase (CAT) – and malondialdehyde concentration (MDA). A suspension of human blood platelets was exposed to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity for 30 and 60 min. The level of changes of the selected parameters of oxidative stress was determined after the exposure and compared to the control samples (not exposed). Results The measurements revealed an increase of the concentration of reactive oxygen species. The largest increase of ROS concentration vs. the control sample was observed after exposure to EMF of 220 V/m intensity for 60 min (from x = 54.64 to x = 72.92). The measurement of MDA concentration demonstrated a statistically significant increase after 30-min exposure to an EMF of 220 V/m intensity in relation to the initial values (from x = 3.18 to x = 4.41). The enzymatic activity of SOD-1 decreased after exposure (the most prominent change was observed after 60-min and 220 V/m intensity from x = 3556.41 to x = 1084.83). The most significant change in activity of catalase was observed after 60 min and 220 v/m exposure (from x = 6.28 to x = 4.15). Conclusions The findings indicate that exposure to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity may cause adverse effects within blood platelets’ oxygen metabolism and thus may lead to physiological dysfunction of the organism. PMID:26788099

  5. Characteristics of GaN-based 500 nm light-emitting diodes with embedded hemispherical air-cavity structure

    Science.gov (United States)

    Zhang, Minyan; Li, Yufeng; Li, Qiang; Su, Xilin; Wang, Shuai; Feng, Lungang; Tian, Zhenhuan; Guo, Maofeng; Zhang, Guowei; Ding, Wen; Yun, Feng

    2018-03-01

    GaN-based 500 nm light-emitting diodes (LEDs) with an air-cavity formed on a laser-drilled hemispherical patterned sapphire substrate (HPSS) were investigated. The cross-section transmission electron microscopy image of the HPSS-LED epilayer indicated that most of the threading dislocations were bent towards the lateral directions. It was found that in InGaN/GaN multiple quantum wells (MQWs) of HPSS-LEDs, there were fewer V-pits and lower surface roughness than those of conventional LEDs which were grown on flat sapphire substrates (FSSs). The high-resolution x-ray diffraction showed that the LED grown on a HPSS has better crystal quality than that grown on a FSS. Compared to FSS-LEDs, the photoluminescence (PL) intensity, the light output power, and the external quantum efficiency at an injected current of 20 mA for the HPSS-LED were enhanced by 81%, 65%, and 62%, respectively, such enhancements can be attributed to better GaN epitaxial quality and higher light extraction. The slightly peak wavelength blueshift of electroluminescence for the HPSS-LED indicated that the quantum confined Stark effect in the InGaN/GaN MQWs has been reduced. Furthermore, it was found that the far-field radiation patterns of the HPSS-LED have smaller view angles than that of the FSS-LED. In addition, the scanning near field optical microscope results revealed that the area above the air-cavity has a larger PL intensity than that without an air-cavity, and the closer to the middle of the air-cavity the stronger the PL intensity. These nano-light distribution findings were in good agreement with the simulation results obtained by the finite difference time domain method.

  6. Origin of the low frequency radiation emitted by radiative polaritons excited by infrared radiation in planar La2O3 films.

    Science.gov (United States)

    Vincent-Johnson, Anita J; Schwab, Yosyp; Mann, Harkirat S; Francoeur, Mathieu; Hammonds, James S; Scarel, Giovanna

    2013-01-23

    Upon excitation in thin oxide films by infrared radiation, radiative polaritons are formed with complex angular frequency ω, according to the theory of Kliewer and Fuchs (1966 Phys. Rev. 150 573). We show that radiative polaritons leak radiation with frequency ω(i) to the space surrounding the oxide film. The frequency ω(i) is the imaginary part of ω. The effects of the presence of the radiation leaked out at frequency ω(i) are observed experimentally and numerically in the infrared spectra of La(2)O(3) films on silicon upon excitation by infrared radiation of the 0TH type radiative polariton. The frequency ω(i) is found in the microwave to far infrared region, and depends on the oxide film chemistry and thickness. The presented results might aid in the interpretation of fine structures in infrared and, possibly, optical spectra, and suggest the study of other similar potential sources of electromagnetic radiation in different physical scenarios.

  7. Efficient Computation of Coherent Synchrotron Radiation Taking into Account 6D Phase Space Distribution of Emitting Electrons

    International Nuclear Information System (INIS)

    Chubar, O.; Couprie, M.-E.

    2007-01-01

    CPU-efficient method for calculation of the frequency domain electric field of Coherent Synchrotron Radiation (CSR) taking into account 6D phase space distribution of electrons in a bunch is proposed. As an application example, calculation results of the CSR emitted by an electron bunch with small longitudinal and large transverse sizes are presented. Such situation can be realized in storage rings or ERLs by transverse deflection of the electron bunches in special crab-type RF cavities, i.e. using the technique proposed for the generation of femtosecond X-ray pulses (A. Zholents et. al., 1999). The computation, performed for the parameters of the SOLEIL storage ring, shows that if the transverse size of electron bunch is larger than the diffraction limit for single-electron SR at a given wavelength -- this affects the angular distribution of the CSR at this wavelength and reduces the coherent flux. Nevertheless, for transverse bunch dimensions up to several millimeters and a longitudinal bunch size smaller than hundred micrometers, the resulting CSR flux in the far infrared spectral range is still many orders of magnitude higher than the flux of incoherent SR, and therefore can be considered for practical use

  8. 47 CFR 73.160 - Vertical plane radiation characteristics, f(θ).

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Vertical plane radiation characteristics, f(Î... SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.160 Vertical plane radiation characteristics, f(θ). (a) The vertical plane radiation characteristics show the relative field being radiated at a...

  9. Reference neutron radiations. Part 1: Characteristics and methods of production

    International Nuclear Information System (INIS)

    2001-01-01

    ISO 8529 consists of the following parts, under the general title Reference neutron radiations: Part 1: Characteristics and methods of production; Part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of response as a function of energy and angle of incidence. This Part 1. of ISO 8529 specifies the reference neutron radiations, in the energy range from thermal up to 20 MeV, for calibrating neutron-measuring devices used for radiation protection purposes and for determining their response as a function of neutron energy. Reference radiations are given for neutron fluence rates of up to 1x10 9 m 2 s-1 , corresponding, at a neutron energy of 1 MeV, to dose-equivalent rates of up to 100 mSv h -1 . This part of ISO 8529 is concerned only with the methods of producing and characterizing the neutron reference radiations. The procedures for applying these radiations for calibrations are described in ISO 8529-2 and ISO 8529-3. The reference radiations specified are the following: neutrons from radionuclide sources, including neutrons from sources in a moderator; neutrons produced by nuclear reactions with charged particles from accelerators; neutrons from reactors. In view of the methods of production and use of them, these reference radiations are divided, for the purposes of this part of ISO 8529, into the following two separate sections. In clause 4, radionuclide neutron sources with wide spectra are specified for the calibration of neutron measuring devices. These sources should be used by laboratories engaged in the routine calibration of neutron-measuring devices, the particular design of which has already been type tested. In clause 5, accelerator-produced monoenergetic neutrons and reactor-produced neutrons with wide or quasi monoenergetic spectra are specified for determining the response of neutron-measuring devices

  10. NEW Fe IX LINE IDENTIFICATIONS USING SOLAR AND HELIOSPHERIC OBSERVATORY/SOLAR ULTRAVIOLET MEASUREMENT OF EMITTED RADIATION AND HINODE/EIS JOINT OBSERVATIONS OF THE QUIET SUN

    International Nuclear Information System (INIS)

    Landi, E.; Young, P. R.

    2009-01-01

    In this work, we study joint observations of Hinode/EUV Imaging Spectrometer (EIS) and Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation of Fe IX lines emitted by the same level of the high energy configuration 3s 2 3p 5 4p. The intensity ratios of these lines are dependent on atomic physics parameters only and not on the physical parameters of the emitting plasma, so that they are excellent tools to verify the relative intensity calibration of high-resolution spectrometers that work in the 170-200 A and 700-850 A wavelength ranges. We carry out extensive atomic physics calculations to improve the accuracy of the predicted intensity ratio, and compare the results with simultaneous EIS-SUMER observations of an off-disk quiet Sun region. We were able to identify two ultraviolet lines in the SUMER spectrum that are emitted by the same level that emits one bright line in the EIS wavelength range. Comparison between predicted and measured intensity ratios, wavelengths and energy separation of Fe IX levels confirms the identifications we make. Blending and calibration uncertainties are discussed. The results of this work are important for cross-calibrating EIS and SUMER, as well as future instrumentation.

  11. Experimental research on the electromagnetic radiation (EMR) characteristics of cracked rock.

    Science.gov (United States)

    Song, Xiaoyan; Li, Xuelong; Li, Zhonghui; Cheng, Fuqi; Zhang, Zhibo; Niu, Yue

    2018-03-01

    Coal rock would emit the electromagnetic radiation (EMR) while deformation and fracture, and there exists structural body in the coal rock because of mining and geological structure. In this paper, we conducted an experimental test the EMR characteristics of cracked rock under loading. Results show that crack appears firstly in the prefabricated crack tip then grows stably parallel to the maximum principal stress, and the coal rock buckling failure is caused by the wing crack tension. Besides, the compressive strength significantly decreases because of the precrack, and the compressive strength increases with the crack angle. Intact rock EMR increases with the loading, and the cracked rock EMR shows stage and fluctuant characteristics. The bigger the angle, the more obvious the stage and fluctuant characteristics, that is EMR becomes richer. While the cracked angle is little, EMR is mainly caused by the electric charge rapid separates because of friction sliding. While the cracked angle is big, there is another significant contribution to EMR, which is caused by the electric dipole transient of crack expansion. Through this, we can know more clear about the crack extends route and the corresponding influence on the EMR characteristic and mechanism, which has important theoretical and practical significance to monitor the coal rock dynamical disasters.

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  13. The effect of ionizing radiation on analog characteristics of MOSFET

    International Nuclear Information System (INIS)

    Ren Diyuan; Yu Xuefeng; Lu Wu; Gao Wenyu; Fan Long; Zhang Guoqiang; Yan Rongliang

    1994-01-01

    The effects of 60 Co γ-ray on the linearity and output characteristics of MOSFETs were investigated. The relations of oxide-trapped charge and Si/SiO 2 interface state density to the decrease of mobility μ-bar and transconductance g m , and the shift of the output curves for both P-MOSFETs and N-MOSFETs were qualitatively described. It was shown that degradation of analog characteristics, for P-MOSFETs, resulted from both oxide-trapped charge and interface state, but the degradation for N-MOSFETs was mainly due to the increase of radiation induced Si-SiO 2 interface state density

  14. Studies on the radiation absorption characteristics of various rocks

    International Nuclear Information System (INIS)

    Rahman, K.N.; Abdullah, S.A.; Gazzaz, M.A.

    1984-05-01

    Radiation absorption characteristics of nine different rocks, namely, ferrugenous quartz, metabasalt, larvikite, coarse grained diorite, coarse grained granite, coarse grained alkali granite, marble, quartz mica schist, and metamorphosed rock are studied. The rocks were collected from Jeddah, Makkah, Mina and Taif areas. Special attention was given on the availability, compactness, physical formation and uniform composition in selecting the rocks. The rocks were identified by optical method and their elemental composition determined by chemical analysis. The data were used to calculate the effective atomic numbers, half value layers mass and linear attenuation coefficients. The half value layers and the linear attenuation coefficientsof these rocks were determined experimentally using Am-241, Cs-137,and Co-60 sources. The results are compared with those obtained by theoretical calculations and agrre within 10%. Most of the rocks show much higher radiation attenuation characteristics than the standard concrete. Rocks containing higher percentage of Fe, Ca, Ti, and Mn show much higher radiation absorption characteristics than concrete. Only granites are found to be almost equivalent to concrete. 12 Ref

  15. A RADIATION TRANSFER SOLVER FOR ATHENA USING SHORT CHARACTERISTICS

    International Nuclear Information System (INIS)

    Davis, Shane W.; Stone, James M.; Jiang Yanfei

    2012-01-01

    We describe the implementation of a module for the Athena magnetohydrodynamics (MHD) code that solves the time-independent, multi-frequency radiative transfer (RT) equation on multidimensional Cartesian simulation domains, including scattering and non-local thermodynamic equilibrium (LTE) effects. The module is based on well known and well tested algorithms developed for modeling stellar atmospheres, including the method of short characteristics to solve the RT equation, accelerated Lambda iteration to handle scattering and non-LTE effects, and parallelization via domain decomposition. The module serves several purposes: it can be used to generate spectra and images, to compute a variable Eddington tensor (VET) for full radiation MHD simulations, and to calculate the heating and cooling source terms in the MHD equations in flows where radiation pressure is small compared with gas pressure. For the latter case, the module is combined with the standard MHD integrators using operator splitting: we describe this approach in detail, including a new constraint on the time step for stability due to radiation diffusion modes. Implementation of the VET method for radiation pressure dominated flows is described in a companion paper. We present results from a suite of test problems for both the RT solver itself and for dynamical problems that include radiative heating and cooling. These tests demonstrate that the radiative transfer solution is accurate and confirm that the operator split method is stable, convergent, and efficient for problems of interest. We demonstrate there is no need to adopt ad hoc assumptions of questionable accuracy to solve RT problems in concert with MHD: the computational cost for our general-purpose module for simple (e.g., LTE gray) problems can be comparable to or less than a single time step of Athena's MHD integrators, and only few times more expensive than that for more general (non-LTE) problems.

  16. Characteristics of radiation field in living environment, 2

    International Nuclear Information System (INIS)

    Nagaoka, Toshi; Sakamoto, Ryuichi; Tsutsumi, Masahiro; Saito, Kimiaki; Moriuchi, Shigeru

    1990-01-01

    A series of environmental radiation survey was carried out on train lines within Tokyo metropolitan area to clarify the characteristics of radiation field in living environment. Eleven JR, 18 private and 10 subway lines were surveyed, which cover 97% of whole train lines in Tokyo district in terms of annual number of passengers. The characteristics of environmental radiation field on train lines were discussed. The mean absorbed dose rate in air due to γ-rays on the subway lines was higher than those on the JR and private lines. It is due to the difference in the radioactivity concentration and the distribution of surrounding materials as the γ-ray sources. On the other hand, the mean dose rate due to cosmic-rays on the subway lines was lower than those on the JR and private lines. It is due to the shielding effect of the upper materials such as soil or building materials of tunnels. The mean dose rates for the JR, private and subway lines were calculated using these obtained data. Though the ratio of mean dose rate of γ-rays to that of cosmic-rays for the subway lines was different from those for the JR and private lines, the sum of γ- and cosmic-ray dose rates for the JR, private and subway lines were comparable, 40∼50 nGy/h for any of them. These data will be useful for a precise and realistic evaluation of collective dose, considering the life style of the public and the variation characteristics of environmental radiation. (author)

  17. Application of Monte Carlo method in determination of secondary characteristic X radiation in XFA

    International Nuclear Information System (INIS)

    Roubicek, P.

    1982-01-01

    Secondary characteristic radiation is excited by primary radiation from the X-ray tube and by secondary radiation of other elements so that excitations of several orders result. The Monte Carlo method was used to consider all these possibilities and the resulting flux of characteristic radiation was simulated for samples of silicate raw materials. A comparison of the results of these computations with experiments allows to determine the effect of sample preparation on the characteristic radiation flux. (M.D.)

  18. Gamma radiation influence on technological characteristics of wheat flour

    International Nuclear Information System (INIS)

    Teixeira, Christian A.H.M.; Inamura, Patricia Y.; Uehara, Vanessa B.; Mastro, Nelida L.d.

    2012-01-01

    This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it. - Highlights: ► We study the influence of gamma radiation on wheat flour and properties of breads. ► Falling number decreased with radiation remaining almost constant up to one month. ► Ionizing radiation may confer an increase in texture parameters, weight and height on the bread.

  19. Effect of the polymer emission on the electroluminescence characteristics of n-ZnO nanorods/p-polymer hybrid light emitting diode

    Science.gov (United States)

    Zaman, S.; Zainelabdin, A.; Amin, G.; Nur, O.; Willander, M.

    2011-09-01

    Hybrid light emitting diodes (LEDs) based on zinc oxide (ZnO) nanorods and polymers (single and blended) were fabricated and characterized. The ZnO nanorods were grown by the chemical bath deposition method at 50°C. Three different LEDs, with blue emitting, orange-red emitting or their blended polymer together with ZnO nanorods, were fabricated and studied. The current-voltage characteristics show good diode behavior with an ideality factor in the range of 2.1 to 2.27 for all three devices. The electroluminescence spectrum (EL) of the blended device has an emission range from 450 nm to 750 nm, due to the intermixing of the blue emission generated by poly(9,9-dioctylfluorene) denoted as PFO with orange-red emission produced by poly(2-methoxy-5(20-ethyl-hexyloxy)-1,4-phenylenevinylene) 1,4-phenylenevinylene) symbolized as MEH PPV combined with the deep-band emission (DBE) of the ZnO nanorods, i.e. it covers the whole visible region and is manifested as white light. The CIE color coordinates showed bluish, orange-red and white emission from the PFO, MEH PPV and blended LEDs with ZnO nanorods, respectively. These results indicate that the choice of the polymer with proper concentration is critical to the emitted color in ZnO nanorods/p-organic polymer LEDs and careful design should be considered to obtain intrinsic white light sources.

  20. Research on Radiation Characteristic of Plasma Antenna through FDTD Method

    Directory of Open Access Journals (Sweden)

    Jianming Zhou

    2014-01-01

    Full Text Available The radiation characteristic of plasma antenna is investigated by using the finite-difference time-domain (FDTD approach in this paper. Through using FDTD method, we study the propagation of electromagnetic wave in free space in stretched coordinate. And the iterative equations of Maxwell equation are derived. In order to validate the correctness of this method, we simulate the process of electromagnetic wave propagating in free space. Results show that electromagnetic wave spreads out around the signal source and can be absorbed by the perfectly matched layer (PML. Otherwise, we study the propagation of electromagnetic wave in plasma by using the Boltzmann-Maxwell theory. In order to verify this theory, the whole process of electromagnetic wave propagating in plasma under one-dimension case is simulated. Results show that Boltzmann-Maxwell theory can be used to explain the phenomenon of electromagnetic wave propagating in plasma. Finally, the two-dimensional simulation model of plasma antenna is established under the cylindrical coordinate. And the near-field and far-field radiation pattern of plasma antenna are obtained. The experiments show that the variation of electron density can introduce the change of radiation characteristic.

  1. Research on radiation characteristic of plasma antenna through FDTD method.

    Science.gov (United States)

    Zhou, Jianming; Fang, Jingjing; Lu, Qiuyuan; Liu, Fan

    2014-01-01

    The radiation characteristic of plasma antenna is investigated by using the finite-difference time-domain (FDTD) approach in this paper. Through using FDTD method, we study the propagation of electromagnetic wave in free space in stretched coordinate. And the iterative equations of Maxwell equation are derived. In order to validate the correctness of this method, we simulate the process of electromagnetic wave propagating in free space. Results show that electromagnetic wave spreads out around the signal source and can be absorbed by the perfectly matched layer (PML). Otherwise, we study the propagation of electromagnetic wave in plasma by using the Boltzmann-Maxwell theory. In order to verify this theory, the whole process of electromagnetic wave propagating in plasma under one-dimension case is simulated. Results show that Boltzmann-Maxwell theory can be used to explain the phenomenon of electromagnetic wave propagating in plasma. Finally, the two-dimensional simulation model of plasma antenna is established under the cylindrical coordinate. And the near-field and far-field radiation pattern of plasma antenna are obtained. The experiments show that the variation of electron density can introduce the change of radiation characteristic.

  2. Radiation resistance characteristics of optical communication system for single mode

    International Nuclear Information System (INIS)

    Ohe, Masamoto; Chigusa, Yoshiki; Kyodo, Tomohisa; Tanaka, Gohtaro; Watanabe, Hajime; Okamoto, Shin-ichi; Yamamoto, Takao.

    1988-01-01

    Optical communication has been utilized also for nuclear power stations and fuel reporocessing plants. As the sufficient safety countermeasures are required there, the amount of information becomes enormous, therefore, optical communication, by which the required space is expected to be reduced, becomes more important. Also in the application to submarine cables, attention must be paid to the radiation resistance as there are the effects of potassium contained in large amount in seawater and uranium deposits in sea bottom. Therefore, the reliability of the components of optical communication systems against radiation becomes a problem. In this study, single mode optical fibers and transmission and receipt modules were selected, and high dose rate irradiation supposing the case of using in a cell and low dose rate, long time irradiation supposing the case of submarine cables were carried out to evaluate the radiation resistance characteristics. The fibers tested were SiO 2 core/F-SiO 2 clad type and GeO 2 -SiO 2 core/SiO 2 clad type. The characteristics of increasing loss in irradiation and restoration after irradiation of the former type were superior to those of the latter type. The output of a receipt module was normal during irradiation, and the output power of a transmission module decreases, but other problems did not arise. (K.I.)

  3. Structural and electrooptical characteristics of quantum dots emitting at 1.3 μm on gallium arsenide

    DEFF Research Database (Denmark)

    Fiore, A.; Oesterle, U.; Stanley, R.P.

    2001-01-01

    We present a comprehensive study of the structural and emission properties of self-assembled InAs quantum dots emitting at 1.3 mum. The dots are grown by molecular beam epitaxy on gallium arsenide substrates. Room-temperature emission at 1.3 mum is obtained by embedding the dots in an InGaAs layer...

  4. The diagnosis of the gastric cancer using catheter-type semiconductor radiation detector. Comparison of diagnostic values of. beta. -emitting radionuclide label with. gamma. -emitting label

    Energy Technology Data Exchange (ETDEWEB)

    Sassa, R; Iwase, T [Asahi Life Foundation, Tokyo (Japan). Inst. for Adult Diseases; Sugita, T; Iio, M

    1975-06-01

    The diagnostic usefulness of /sup 32/P-phosphate for human gastric cancer, using a catheter-type semiconductor radiation detector (CASRAD) combined with gastrofiberscope technique, has already been reported by the authors. They have in addition used sup(99m)Tc-bleomycin, sup(99m)Tc-tetracycline in the diagnosis of experimental rabbit gastric cancer, too. In the present study, further refinement of the technique for the ..beta..-ray labeled substance (/sup 32/P-phosphate) for detection of the gastric cancer was compared with that of ..gamma..-ray labeled substance (sup(99m)Tc-tetracycline). A more correct diagnosis of the gastric cancer by in vivo measurement of beta activity could be obtained, when the collimater, made of stainless steel, was attached to the top of the detector. In this way contribution to the count from the adjacent tissues or organs could be eliminated. They were unable to produce an effective and useful collimater for ..gamma..-ray labeled substance which could to be used safely in vivo. Because of the unsatisfactory collimater, radioactivities of the adjacent organs caused on increase in the radioactivity of the background. Therefore inspite of the recent introduction of various sup(99m)Tc-tumor agents, these labels were not applicable to the CASRAD method. For such a small detector system, ..beta..-labels, represented by /sup 32/P-phosphate, was still prefererable to ..gamma..-labels.

  5. Wave Characteristics of Temperature Inversion Process of Nighttime Radiation,

    Science.gov (United States)

    1983-12-09

    CHARACTERISTICS OF TEMPERATURE INVERSION PROCESS OF NIGHTTIME RADIATION By: Zhou Mingyu and Zhang ¥i English pages: 8 Source: Kexue Tongbao, 1982, pp. 156...lJournal of Meteorology], 39 (1981), 1:70-81. 3. Drazin, P. G., J. Fluid. Mech., 4 (1958), 214-224. 4. Zhou Mingyu et al., QIXIANG XUEBAO, 38 (1980), 3: 250...258. 5. Emnanuel, C. B., B-L. Meteor., 5(1973), N(1/2)8 19-27. 6. Zhou Mingyu et al., J. Acoust. Soc., A. m., 68 (1980), 1: 303-308. 8 I iI

  6. Characteristics of natural background external radiation and effective dose equivalent

    International Nuclear Information System (INIS)

    Fujimoto, Kenzo

    1989-01-01

    The two sources of natural radiation - cosmic rays and primordial radionuclides - are described. The factors affecting radiation doses received from natural radiation and the calculation of effective dose equivalent due to natural radiation are discussed. 10 figs., 3 tabs

  7. Discrete curved ray-tracing method for radiative transfer in an absorbing-emitting semitransparent slab with variable spatial refractive index

    International Nuclear Information System (INIS)

    Liu, L.H.

    2004-01-01

    A discrete curved ray-tracing method is developed to analyze the radiative transfer in one-dimensional absorbing-emitting semitransparent slab with variable spatial refractive index. The curved ray trajectory is locally treated as straight line and the complicated and time-consuming computation of ray trajectory is cut down. A problem of radiative equilibrium with linear variable spatial refractive index is taken as an example to examine the accuracy of the proposed method. The temperature distributions are determined by the proposed method and compared with the data in references, which are obtained by other different methods. The results show that the discrete curved ray-tracing method has a good accuracy in solving the radiative transfer in one-dimensional semitransparent slab with variable spatial refractive index

  8. Pollution characteristics and health risk assessment of volatile organic compounds emitted from different plastic solid waste recycling workshops.

    Science.gov (United States)

    He, Zhigui; Li, Guiying; Chen, Jiangyao; Huang, Yong; An, Taicheng; Zhang, Chaosheng

    2015-04-01

    The pollution profiles of volatile organic compounds (VOCs) emitted from different recycling workshops processing different types of plastic solid waste (PSW) and their health risks were investigated. A total of 64 VOCs including alkanes, alkenes, monoaromatics, oxygenated VOCs (OVOCs), chlorinated VOCs (ClVOCs) and acrylonitrile during the melting extrusion procedure were identified and quantified. The highest concentration of total VOCs (TVOC) occurred in the poly(acrylonitrile-butadiene styrene) (ABS) recycling workshop, followed by the polystyrene (PS), polypropylene (PP), polyamide (PA), polyvinyl chloride (PVC), polyethylene (PE) and polycarbonate (PC) workshops. Monoaromatics were found as the major component emitted from the ABS and PS recycling workshops, while alkanes were mainly emitted from the PE and PP recycling processes, and OVOCs from the PVC and PA recycling workshops. According to the occupational exposure limits' (OEL) assessment, the workers suffered acute and chronic health risks in the ABS and PS recycling workshops. Meanwhile, it was found that most VOCs in the indoor microenvironments were originated from the melting extrusion process, while the highest TVOC concentration was observed in the PS rather than in the ABS recycling workshop. Non-cancer hazard indices (HIs) of all individual VOCs were <1.0, whereas the total HI in the PS recycling workshop was 1.9, posing an adverse chronic health threat. Lifetime cancer risk assessment suggested that the residents also suffered from definite cancer risk in the PS, PA, ABS and PVC recycling workshops. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Gamma radiation influence on technological characteristics of wheat flour

    Science.gov (United States)

    Teixeira, Christian A. H. M.; Inamura, Patricia Y.; Uehara, Vanessa B.; Mastro, Nelida L. d.

    2012-08-01

    This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it.

  10. An explanation of efficiency droop in InGaN-based light emitting diodes: saturated radiative recombination rate at randomly distributed In-rich active areas

    International Nuclear Information System (INIS)

    Shim, Jong-In; Kim, Hyun-Sung; Shin, Dong-Soo; Yoo, Han-Youl

    2011-01-01

    We present a comprehensive model of the dependence of the internal quantum efficiency (IQE) on both the temperature and the carrier density in InGaN-based blue and green light emitting diodes (LEDs). In our model, carriers are dominantly located and recombine both radiatively and nonradiatively inside randomly distributed In-rich areas of the InGaN quantum wells (QWs). In those areas, the carrier density is very high even at a small current density. We propose that the saturated radiative recombination rate is a primary factor determining the IQE droop of InGaN based LEDs. In typical InGaN-based QWs, it is common for the total carrier recombination rate to be smaller than the carrier injection rate even at a small current density. This is mostly attributable to the saturation of the radiative recombination rate. The saturation of the radiative recombination rate increases carrier density in InGaN QWs, enlarges nonradiative carrier losses, and eventually gives rise to the large IQE droop with increasing current. We show how the radiative recombination rate saturates and the radiative recombination rate has influence on the IQE droop in InGaN-based QW LEDs.

  11. Impact of electromagnetic radiation emitted by monitors on changes in the cellular membrane structure and protective antioxidant effect of vitamin A - In vitro study.

    Science.gov (United States)

    Lewicka, Małgorzata; Henrykowska, Gabriela; Zawadzka, Magdalena; Rutkowski, Maciej; Pacholski, Krzysztof; Buczyński, Andrzej

    2017-07-14

    The increasing number of devices emitting electromagnetic radiation (EMR) in people's everyday life attracted the attention of researchers because of possible adverse effects of this factor on living organisms. One of the EMR effect may be peroxidation of lipid membranes formed as a result of free radical process. The article presents the results of in vitro studies aimed at identifying changes in malondialdehyde (MDA) concentration - a marker of lipid peroxidation and antioxidant role of vitamin A during the exposure of blood platelets to electromagnetic radiation generated by liquid-crystal-display (LCD) monitors. Electromagnetic radiation emitted by LCD monitors is characterized by parameters: 1 kHz frequency and 220 V/m intensity (15 cm from display screen). The time of exposure was 30 and 60 min. The study was conducted on porcine blood platelets. The samples were divided into 6 groups: unexposed to radiation, unexposed + vitamin A, exposed for 30 min, exposed for 30 min + vitamin A, exposed for 60 min, exposed for 60 min + vitamin A. The MDA concentration in blood platelets increases significantly as compared to control values after 60 min of exposure to EMR. A significant decrease in MDA concentration after the addition of vitamin A was noticed. In the blood samples exposed to EMR for 30 and 60 min the MDA concentration was significantly increased by addition of vitamin A. The results show the possibly negative effect of electromagnetic radiation on the cellular membrane structure manifested by changes in malondialdehyde concentration and indicate a possible protective role of vitamin A in this process. Int J Occup Med Environ Health 2017;30(5):695-703. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  12. Small signal modulation characteristics of red-emitting (λ = 610 nm) III-nitride nanowire array lasers on (001) silicon

    KAUST Repository

    Jahangir, Shafat; Frost, Thomas; Hazari, Arnab; Yan, Lifan; Stark, Ethan; LaMountain, Trevor; Millunchick, Joanna M.; Ooi, Boon S.; Bhattacharya, Pallab

    2015-01-01

    The small signal modulation characteristics of an InGaN/GaN nanowire array edge- emitting laser on (001) silicon are reported. The emission wavelength is 610 nm. Lattice matched InAlN cladding layers were incorporated in the laser heterostructure for better mode confinement. The suitability of the nanowire lasers for use in plastic fiber communication systems with direct modulation is demonstrated through their modulation bandwidth of f-3dB,max = 3.1 GHz, very low values of chirp (0.8 Å) and α-parameter, and large differential gain (3.1 × 10-17 cm2).

  13. Small signal modulation characteristics of red-emitting (λ = 610 nm) III-nitride nanowire array lasers on (001) silicon

    KAUST Repository

    Jahangir, Shafat

    2015-02-16

    The small signal modulation characteristics of an InGaN/GaN nanowire array edge- emitting laser on (001) silicon are reported. The emission wavelength is 610 nm. Lattice matched InAlN cladding layers were incorporated in the laser heterostructure for better mode confinement. The suitability of the nanowire lasers for use in plastic fiber communication systems with direct modulation is demonstrated through their modulation bandwidth of f-3dB,max = 3.1 GHz, very low values of chirp (0.8 Å) and α-parameter, and large differential gain (3.1 × 10-17 cm2).

  14. The effect of a charge control layer on the electroluminescent characteristic of blue and white organic light-emitting diodes.

    Science.gov (United States)

    Lee, Dong Hyung; Lee, Seok Jae; Koo, Ja-Ryong; Lee, Ho Won; Shin, Hyun Su; Lee, Song Eun; Kim, Woo Young; Lee, Kum Hee; Yoon, Seung Soo; Kim, Young Kwan

    2014-08-01

    We investigated blue fluorescent organic light-emitting diode (OLED) with a charge control layer (CCL) to produce high efficiency and improve the half-decay lifetime. Three types of devices (device A, B, and C) were fabricated following the number of CCLs within the emitting layer (EML), maintaining the thickness of whole EML. The CCL and host material, 2-methyl-9,10-di(2-naphthyl)anthracene, which has a bipolar property, was able to control the carrier movement with ease inside the EML. Device B demonstrated a maximum luminous efficiency (LE) and external quantum efficiency (EQE) of 9.19 cd/A and 5.78%, respectively. It also showed that the enhancement of the half-decay lifetime, measured at an initial luminance of 1,000 cd/m2, was 1.5 times longer than that of the conventional structure. A hybrid white OLED (WOLED) was also fabricated using a phosphorescent red emitter, bis(2-phenylquinoline)-acetylacetonate iridium III doped in 4,4'-N,N'-dicarbazolyl-biphenyl. The property of the hybrid WOLED with CCL showed a maximum LE and an EQE of 13.46 cd/A and 8.32%, respectively. It also showed white emission with Commission International de L'Éclairage coordinates of (x = 0.41, y = 0.33) at 10 V.

  15. Thermoluminescent characteristics of diopside-teflon composites for radiation dosimetry

    International Nuclear Information System (INIS)

    Melo, A.P.; Caldas, L.V.E.

    2006-01-01

    Diopside - Teflon composites were been studied in relation to their dosimetric properties for high-dose dosimetry. Diopside from Minas Gerais, Brazil, CaMg(Si 2 O 6 ), was obtained in form of rude mineral with inclusions of quartz. The samples were prepared and only Diopside grains obtained. Pellets of Diopside-Teflon composites were prepared in the proportion of 2(Teflon): 1 (Diopside).The TL response repeatability presented a maximum coefficient of variation of 7.5%. The calibration curve is linear between 0.5 Gy and 1 kGy. TL emission spectra present three emissions of similar intensities at 570 nm, 590 nm and between 610-635 nm. The results suggest that the material presents good characteristics for use as high-dose radiation detectors. (Author)

  16. The effect of cloud shape on radiative characteristics

    International Nuclear Information System (INIS)

    Welch, R.M.; Zdunkowski, W.G.

    1981-01-01

    Cumulus cloud radiative characteristics are calculated using Monte-Carlo codes as a function of solar zenith angle for clouds approximated by hemispherical, cylindrical and combination-type geometries. Values of cloud reflectivity, transmissivity and absorptivity are compared with values computed from assuming cubic and rectangular geometries, the basis for most previous finite cloud calculations. Poor agreement is obtained at large cloud sizes and only marginal agreement is obtained at small cloud sizes. Two approximations based upon various scalings of cloud optical depth (extinction parameters) are also constructed, but with limited success in reproducing the values produced by the convex shaped clouds. Reasonable agreement among the various approximations occurs at large solar zenith angles, but extremely poor agreement may occur at small angles. (orig./WB) [de

  17. Characteristics of outage radiation fields around various reactor components

    International Nuclear Information System (INIS)

    Verzilov, Y.; Husain, A.; Corbin, G.

    2008-01-01

    Full text: Activity monitoring surveys, consisting of gamma spectroscopy and dose rate measurements, of various CANDU station components such as the reactor face, feeder cabinet, steam generators and moderator heat exchangers are often performed during shutdown in order to trend the transport of activity around the primary heat transport and moderator systems. Recently, the increased dose expenditure for work such as feeder inspection and replacement in the reactor vault has also spurred interest in improved characterization of the reactor face fields to facilitate better ALARA decision making and hence a reduction in future dose expenditures. At present, planning for reactor face work is hampered by insufficient understanding of the relative contribution of the various components to the overall dose. In addition to the increased dose expenditure for work at the reactor face, maintenance work associated with horizontal flux detectors and liquid injection systems has also resulted in elevated dose expenditures. For instance at Darlington, radiation fields in the vicinity of horizontal flux detectors (HFD) and Liquid Injection Shutdown System (LISS) nozzle bellows are trending upwards with present contact fields being in the range 16-70 rem/h and working distance fields being in the range 100-500 mrem/h. This paper presents findings based on work currently being funded by the CANDU Owners Group. Measurements were performed at Ontario Power Generation's Pickering and Darlington nuclear stations. Specifically, the following are addressed: Characteristics of Reactor Vault Fields; Characteristics of Steam Generator Fields; Characteristics of Moderator Heat Exchanger Fields. Measurements in the reactor vault were performed at the reactor face, along the length of end fittings, along the length of feeders, at the bleed condenser and at the HFD and LISS nozzle bellows. Steam generator fields were characterized at various elevations above the tube sheet, with and without the

  18. Diminution of acute radiation reaction of mouse skin with low-intensity infrared laser/red diodes-emitted light

    International Nuclear Information System (INIS)

    Meshcherikova, V.V.; Klimakov, B.D.; Goldobenko, G.V.; Vajnson, A.A.

    2000-01-01

    Efficiency of the application of different regimes of laser treatment of radiation-induced skin reactions in mice feet is compared. Posterior limb feet of mice were exposed to acute X radiation at 30-36 Gy dose or fractionated radiation at 45 Gy dose. In the day of primary irradiation or different time later the feet were treated using magnetic infrared laser therapeutic MILTA-01 apparatus. Magnetic and light components of the MILTA-01 apparatus reduce the effect of radiation on mice skin corresponding two time decrease in X-radiation dose [ru

  19. Characteristics of sound radiation from turbulent premixed flames

    Science.gov (United States)

    Rajaram, Rajesh

    Turbulent combustion processes are inherently unsteady and, thus, a source of acoustic radiation, which occurs due to the unsteady expansion of reacting gases. While prior studies have extensively characterized the total sound power radiated by turbulent flames, their spectral characteristics are not well understood. The objective of this research work is to measure the flow and acoustic properties of an open turbulent premixed jet flame and explain the spectral trends of combustion noise. The flame dynamics were characterized using high speed chemiluminescence images of the flame. A model based on the solution of the wave equation with unsteady heat release as the source was developed and was used to relate the measured chemiluminescence fluctuations to its acoustic emission. Acoustic measurements were performed in an anechoic environment for several burner diameters, flow velocities, turbulence intensities, fuels, and equivalence ratios. The acoustic emissions are shown to be characterized by four parameters: peak frequency (Fpeak), low frequency slope (beta), high frequency slope (alpha) and Overall Sound Pressure Level (OASPL). The peak frequency (Fpeak) is characterized by a Strouhal number based on the mean velocity and a flame length. The transfer function between the acoustic spectrum and the spectrum of heat release fluctuations has an f2 dependence at low frequencies, while it converged to a constant value at high frequencies. Furthermore, the OASPL was found to be characterized by (Fpeak mfH)2, which resembles the source term in the wave equation.

  20. Impact of phonon coupling on the radiative nuclear reaction characteristics

    Directory of Open Access Journals (Sweden)

    Achakovskiy Oleg

    2016-01-01

    Full Text Available The pygmy dipole resonance and photon strength functions (PSF in stable and unstable Ni and Sn isotopes are calculated within the microscopic self-consistent version of the extended theory of finite Fermi systems in the quasiparticle time blocking approximation. The approach includes phonon coupling (PC effects in addition to the standard QRPA approach. The Skyrme force SLy4 is used. A pygmy dipole resonance in 72Ni is predicted at the mean energy of 12.4 MeV exhausting 25.7% of the total energy-weighted sum rule. With our microscopic E1 PSFs in the EMPIRE 3.1 code, the following radiative nuclear reaction characteristics have been calculated for several stable and unstable even-even Sn and Ni isotopes: 1 neutron capture cross sections, 2 corresponding neutron capture gamma-spectra, 3 average radiative widths of neutron resonances. Here, three variants of the microscopic nuclear level density models have been used and a comparison with the phenomenological generalized superfluid model has been performed. In all the considered properties, including the recent experimental data for PSF in Sn isotopes, the PC contributions turned out to be significant, as compared with the QRPA one, and necessary to explain the available experimental data.

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

    Directory of Open Access Journals (Sweden)

    S. L. Chernyshev

    2015-01-01

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

  2. Effect of Radiofrequency Radiation Emitted from 2G and 3G Cell Phone on Developing Liver of Chick Embryo - A Comparative Study.

    Science.gov (United States)

    D'Silva, Mary Hydrina; Swer, Rijied Thompson; Anbalagan, J; Rajesh, Bhargavan

    2017-07-01

    The increasing scientific evidence of various health hazards on exposure of Radiofrequency Radiation (RFR) emitted from both the cell phones and base stations have caused significant media attention and public discussion in recent years. The mechanism of interaction of RF fields with developing tissues of children and fetuses may be different from that of adults due to their smaller physical size and variation in tissue electromagnetic properties. The present study may provide an insight into the basic mechanisms by which RF fields interact with developing tissues in an embryo. To evaluate the possible tissue and DNA damage in developing liver of chick embryo following chronic exposure to Ultra-High Frequency/Radiofrequency Radiation (UHF/RFR) emitted from 2G and 3G cell phone. Fertilized chick embryos were incubated in four groups. Group A-experimental group exposed to 2G radiation (60 eggs), Group B- experimental group exposed to 3G radiation (60 eggs), Group C- sham exposed control group (60 eggs) and Group D- control group (48 eggs). On completion of scheduled duration, the embryos were collected and processed for routine histological studies to check structural changes in liver. The nuclear diameter and karyorrhexis changes of hepatocytes were analysed using oculometer and square reticule respectively. The liver procured from one batch of eggs from all the four groups was subjected to alkaline comet assay technique to assess DNA damage. The results were compared using one-way ANOVA test. In our study, the exposure of developing chick embryos to 2G and 3G cell phone radiations caused structural changes in liver in the form of dilated sinusoidal spaces with haemorrhage, increased vacuolations in cytoplasm, increased nuclear diameter and karyorrhexis and significantly increased DNA damage. The chronic exposure of chick embryo liver to RFR emitted from 2G and 3G cell phone resulted in various structural changes and DNA damage. The changes were more pronounced in 3

  3. Effect of Radiofrequency Radiation Emitted from 2G and 3G Cell Phone on Developing Liver of Chick Embryo – A Comparative Study

    Science.gov (United States)

    Swer, Rijied Thompson; Anbalagan, J.; Rajesh, Bhargavan

    2017-01-01

    Introduction The increasing scientific evidence of various health hazards on exposure of Radiofrequency Radiation (RFR) emitted from both the cell phones and base stations have caused significant media attention and public discussion in recent years. The mechanism of interaction of RF fields with developing tissues of children and fetuses may be different from that of adults due to their smaller physical size and variation in tissue electromagnetic properties. The present study may provide an insight into the basic mechanisms by which RF fields interact with developing tissues in an embryo. Aim To evaluate the possible tissue and DNA damage in developing liver of chick embryo following chronic exposure to Ultra-High Frequency/Radiofrequency Radiation (UHF/RFR) emitted from 2G and 3G cell phone. Materials and Methods Fertilized chick embryos were incubated in four groups. Group A-experimental group exposed to 2G radiation (60 eggs), Group B- experimental group exposed to 3G radiation (60 eggs), Group C- sham exposed control group (60 eggs) and Group D– control group (48 eggs). On completion of scheduled duration, the embryos were collected and processed for routine histological studies to check structural changes in liver. The nuclear diameter and karyorrhexis changes of hepatocytes were analysed using oculometer and square reticule respectively. The liver procured from one batch of eggs from all the four groups was subjected to alkaline comet assay technique to assess DNA damage. The results were compared using one-way ANOVA test. Results In our study, the exposure of developing chick embryos to 2G and 3G cell phone radiations caused structural changes in liver in the form of dilated sinusoidal spaces with haemorrhage, increased vacuolations in cytoplasm, increased nuclear diameter and karyorrhexis and significantly increased DNA damage. Conclusion The chronic exposure of chick embryo liver to RFR emitted from 2G and 3G cell phone resulted in various structural

  4. Radiation and thermal characteristics of mouse lymphoma cells and their radiation-sensitive mutant

    International Nuclear Information System (INIS)

    Baba, Yuji; Yasunaga, Tadamasa; Uozumi, Hideaki; Takahashi, Mutsumasa; Sawada, Shozo.

    1988-01-01

    Radiation and thermal characteristics of L5178Y cells and their radiation-sensitive mutant M10 cells were studied by the colony-forming method and the dye-exclusion method using eosin-Y. Although M10 cells were remarkably radiation-sensitive compared with L5178Y cells, it was diffcult to cause interphase death of M10 after a large dose of irradiation. After heat treatments, L5178Y cells revealed more cell destruction and were stained well by eosin-Y, but it was relatively difficult to produce cell destruction of M10 cells, which showed poor staining by eosin-Y. When assayed by the colony-forming method, M10 cells were also heat-resistant compared to L5178Y. The dye-exclusion rate was closely correlated with cell survival after hyperthermia of L5178Y cells, suggesting that this is a simple method of detecting the thermosensitivity and thermotolerance of cancer cells. The difference in survival of L5178Y cells and M10 cells after combined treatment with gamma irradiation and hyperthermia was smaller than with gamma irradiation alone. It was also found that there was a relationship between radiation-induced interphase death and hyperthermia-induced interphase death, and that interphase death accounted for a major part of cell death caused by hyperthermia in mouse leukemia cells. (author)

  5. Survey of the Effects of Exposure to 900 MHz Radiofrequency Radiation Emitted by a GSM Mobile Phone on the Pattern of Muscle Contractions in an Animal Model

    Directory of Open Access Journals (Sweden)

    Mortazavi S. M. J.

    2015-09-01

    Full Text Available Background: The rapid development of wireless telecommunication technologies over the past decades, has led to significant changes in the exposure of the general public to electromagnetic fields. Nowadays, people are continuously exposed to different sources of electromagnetic fields such as mobile phones, mobile base stations, cordless phones, Wi-Fi routers, and power lines. Therefore, the last decade witnessed a rapidly growing concern about the possible health effects of exposure to electromagnetic fields emitted by these sources. Materials and Methods: In this study that was aimed at investigating the effects of exposure to radiofrequency (RF radiation emitted by a GSM mobile phone on the pattern of contraction in frog’s isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz, pulse height of contractions, the time interval between two subsequent contractions and the latency period were measured. Results: Our findings showed that the pulse height of contractions muscle could be affected by the exposure to electromagnetic fields. Especially, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. Conclusion: These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions

  6. Survey of the Effects of Exposure to 900 MHz Radiofrequency Radiation Emitted by a GSM Mobile Phone on the Pattern of Muscle Contractions in an Animal Model.

    Science.gov (United States)

    Mortazavi, S M J; Rahimi, S; Talebi, A; Soleimani, A; Rafati, A

    2015-09-01

    The rapid development of wireless telecommunication technologies over the past decades, has led to significant changes in the exposure of the general public to electromagnetic fields. Nowadays, people are continuously exposed to different sources of electromagnetic fields such as mobile phones, mobile base stations, cordless phones, Wi-Fi routers, and power lines. Therefore, the last decade witnessed a rapidly growing concern about the possible health effects of exposure to electromagnetic fields emitted by these sources. In this study that was aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted by a GSM mobile phone on the pattern of contraction in frog's isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz), pulse height of contractions, the time interval between two subsequent contractions and the latency period were measured. Our findings showed that the pulse height of contractions muscle could be affected by the exposure to electromagnetic fields. Especially, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

  7. Measurement of characteristic prompt gamma rays emitted from oxygen and carbon in tissue-equivalent samples during proton beam irradiation.

    Science.gov (United States)

    Polf, Jerimy C; Panthi, Rajesh; Mackin, Dennis S; McCleskey, Matt; Saastamoinen, Antti; Roeder, Brian T; Beddar, Sam

    2013-09-07

    The purpose of this work was to characterize how prompt gamma (PG) emission from tissue changes as a function of carbon and oxygen concentration, and to assess the feasibility of determining elemental concentration in tissues irradiated with proton beams. For this study, four tissue-equivalent water-sucrose samples with differing densities and concentrations of carbon, hydrogen, and oxygen were irradiated with a 48 MeV proton pencil beam. The PG spectrum emitted from each sample was measured using a high-purity germanium detector, and the absolute detection efficiency of the detector, average beam current, and delivered dose distribution were also measured. Changes to the total PG emission from (12)C (4.44 MeV) and (16)O (6.13 MeV) per incident proton and per Gray of absorbed dose were characterized as a function of carbon and oxygen concentration in the sample. The intensity of the 4.44 MeV PG emission per incident proton was found to be nearly constant for all samples regardless of their carbon concentration. However, we found that the 6.13 MeV PG emission increased linearly with the total amount (in grams) of oxygen irradiated in the sample. From the measured PG data, we determined that 1.64 × 10(7) oxygen PGs were emitted per gram of oxygen irradiated per Gray of absorbed dose delivered with a 48 MeV proton beam. These results indicate that the 6.13 MeV PG emission from (16)O is proportional to the concentration of oxygen in tissue irradiated with proton beams, showing that it is possible to determine the concentration of oxygen within tissues irradiated with proton beams by measuring (16)O PG emission.

  8. Development of computational pregnant female and fetus models and assessment of radiation dose from positron-emitting tracers

    DEFF Research Database (Denmark)

    Xie, Tianwu; Zaidi, H.

    2016-01-01

    /fetus presents a high sensitivity to ionizing radiation. Therefore, estimation of the radiation dose delivered to the embryo/fetus and pregnant patients from PET examinations to assess potential radiation risks is highly praised. Methods: We constructed eight embryo/fetus models at various gestation periods......Purpose: Molecular imaging using PET and hybrid (PET/CT and PET/MR) modalities nowadays plays a pivotal role in the clinical setting for diagnosis and staging, treatment response monitoring, and radiation therapy treatment planning of a wide range of oncologic malignancies. The developing embryo...

  9. Characteristics of the radiation prevention metrology laboratory 'Cajavec' - Banjaluka

    International Nuclear Information System (INIS)

    Tomljenovic, I.; Ninkovic, M.; Kolonic, Dz.

    2004-01-01

    Radiation metrology laboratory built in the factory 'Cajavec' in Banja Luka, planed for gauge the detectors of ionization radiation. Laboratory as part of the large factory building , thus projected and formed according to positive radiation principles. Walls are constructed of basic concrete, main entrance of lead, approaching the radiation bench from the back side. Sound and light signal system connected with dosemeter for showing mini dose of radiation creating conditions for safe work of the dosemeterists. (author) [sr

  10. Effect of heterostructure design on carrier injection and emission characteristics of 295 nm light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Mehnke, Frank, E-mail: mehnke@physik.tu-berlin.de; Kuhn, Christian; Stellmach, Joachim; Rothe, Mark-Antonius; Reich, Christoph; Ledentsov, Nikolay; Pristovsek, Markus; Wernicke, Tim [Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstr. 36, EW 6-1, 10623 Berlin (Germany); Kolbe, Tim; Lobo-Ploch, Neysha; Rass, Jens [Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Kneissl, Michael [Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstr. 36, EW 6-1, 10623 Berlin (Germany); Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany)

    2015-05-21

    The effects of the heterostructure design on the injection efficiency and external quantum efficiency of ultraviolet (UV)-B light emitting diodes (LEDs) have been investigated. It was found that the functionality of the Al{sub x}Ga{sub 1−x}N:Mg electron blocking layer is strongly influenced by its aluminum mole fraction x and its magnesium doping profile. By comparing LED electroluminescence, quantum well photoluminescence, and simulations of LED heterostructure, we were able to differentiate the contributions of injection efficiency and internal quantum efficiency to the external quantum efficiency of UV LEDs. For the optimized heterostructure using an Al{sub 0.7}Ga{sub 0.3}N:Mg electron blocking layer with a Mg to group III ratio of 4% in the gas phase the electron leakage currents are suppressed without blocking the injection of holes into the multiple quantum well active region. Flip chip mounted LED chips have been processed achieving a maximum output power of 3.5 mW at 290 mA and a peak external quantum efficiency of 0.54% at 30 mA.

  11. A SPME-based method for rapidly and accurately measuring the characteristic parameter for DEHP emitted from PVC floorings.

    Science.gov (United States)

    Cao, J; Zhang, X; Little, J C; Zhang, Y

    2017-03-01

    Semivolatile organic compounds (SVOCs) are present in many indoor materials. SVOC emissions can be characterized with a critical parameter, y 0 , the gas-phase SVOC concentration in equilibrium with the source material. To reduce the required time and improve the accuracy of existing methods for measuring y 0 , we developed a new method which uses solid-phase microextraction (SPME) to measure the concentration of an SVOC emitted by source material placed in a sealed chamber. Taking one typical indoor SVOC, di-(2-ethylhexyl) phthalate (DEHP), as the example, the experimental time was shortened from several days (even several months) to about 1 day, with relative errors of less than 5%. The measured y 0 values agree well with the results obtained by independent methods. The saturated gas-phase concentration (y sat ) of DEHP was also measured. Based on the Clausius-Clapeyron equation, a correlation that reveals the effects of temperature, the mass fraction of DEHP in the source material, and y sat on y 0 was established. The proposed method together with the correlation should be useful in estimating and controlling human exposure to indoor DEHP. The applicability of the present approach for other SVOCs and other SVOC source materials requires further study. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Auger Recombination in III-Nitride Nanowires and Its Effect on Nanowire Light-Emitting Diode Characteristics

    KAUST Repository

    Guo, Wei; Zhang, Meng; Bhattacharya, Pallab; Heo, Junseok

    2011-01-01

    We have measured the Auger recombination coefficients in defect-free InGaN nanowires (NW) and InGaN/GaN dot-in-nanowire (DNW) samples grown on (001) silicon by plasma-assisted molecular beam epitaxy. The nanowires have a density of ∼1×1011 cm-2 and exhibit photoluminescence emission peak at λ ∼ 500 nm. The Auger coefficients as a function of excitation power have been derived from excitation dependent and time-resolved photoluminescence measurements over a wide range of optical excitation power density. The values of C0, defined as the Auger coefficient at low excitation, are 6.1 × 10-32 and 4.1×10-33 cm6·s-1 in the NW and DNW samples, respectively, which are in reasonably good agreement with theoretical predictions for InGaN alloy semiconductors. Light-emitting diodes made with the NW and DNW samples exhibit no efficiency droop up to an injection current density of 400 A/cm 2. © 2011 American Chemical Society.

  13. Effect of heterostructure design on carrier injection and emission characteristics of 295 nm light emitting diodes

    International Nuclear Information System (INIS)

    Mehnke, Frank; Kuhn, Christian; Stellmach, Joachim; Rothe, Mark-Antonius; Reich, Christoph; Ledentsov, Nikolay; Pristovsek, Markus; Wernicke, Tim; Kolbe, Tim; Lobo-Ploch, Neysha; Rass, Jens; Kneissl, Michael

    2015-01-01

    The effects of the heterostructure design on the injection efficiency and external quantum efficiency of ultraviolet (UV)-B light emitting diodes (LEDs) have been investigated. It was found that the functionality of the Al x Ga 1−x N:Mg electron blocking layer is strongly influenced by its aluminum mole fraction x and its magnesium doping profile. By comparing LED electroluminescence, quantum well photoluminescence, and simulations of LED heterostructure, we were able to differentiate the contributions of injection efficiency and internal quantum efficiency to the external quantum efficiency of UV LEDs. For the optimized heterostructure using an Al 0.7 Ga 0.3 N:Mg electron blocking layer with a Mg to group III ratio of 4% in the gas phase the electron leakage currents are suppressed without blocking the injection of holes into the multiple quantum well active region. Flip chip mounted LED chips have been processed achieving a maximum output power of 3.5 mW at 290 mA and a peak external quantum efficiency of 0.54% at 30 mA

  14. Auger Recombination in III-Nitride Nanowires and Its Effect on Nanowire Light-Emitting Diode Characteristics

    KAUST Repository

    Guo, Wei

    2011-04-13

    We have measured the Auger recombination coefficients in defect-free InGaN nanowires (NW) and InGaN/GaN dot-in-nanowire (DNW) samples grown on (001) silicon by plasma-assisted molecular beam epitaxy. The nanowires have a density of ∼1×1011 cm-2 and exhibit photoluminescence emission peak at λ ∼ 500 nm. The Auger coefficients as a function of excitation power have been derived from excitation dependent and time-resolved photoluminescence measurements over a wide range of optical excitation power density. The values of C0, defined as the Auger coefficient at low excitation, are 6.1 × 10-32 and 4.1×10-33 cm6·s-1 in the NW and DNW samples, respectively, which are in reasonably good agreement with theoretical predictions for InGaN alloy semiconductors. Light-emitting diodes made with the NW and DNW samples exhibit no efficiency droop up to an injection current density of 400 A/cm 2. © 2011 American Chemical Society.

  15. Fractal characteristics correlation between the solar total radiation and net radiation on the apple tree canopy

    International Nuclear Information System (INIS)

    Meng Ping; Zhang Jingsong

    2005-01-01

    The characteristics correlation between solar total radiations(Q) and net radiation(R n) on the apple tree canopy at mainly growth stage in the hilly of Taihang Mountain are analyzed with fractal theory based on regression analysis. The results showed that:1)Q and R n had good liner correlation. The regression function was as the following:R n=0.740 8Q-32.436, which coefficient r is 0.981 1(n=26 279), F cal= 343 665.2 F 0.01 36 277=6.63; 2)The fractal dimension curves of Q and R n both had two no s caling regions, which circumscription time value of the inflexion was 453 and 441 minutes respectively.In the first region, fractal dimensions of Q and R n was 1.112 6, 1.131 9 respectively,and 1.913 6@@@ 1.883 4 in the second region.Those information showed that fractal characteristics of Q and R n is similar. So R n can be calculated with Q on the apple tree canopy

  16. Monochromic radiation through light-emitting diode (LED positively augments in vitro shoot regeneration in Orchid (Dendrobium sonia

    Directory of Open Access Journals (Sweden)

    Vandita Billore

    2017-07-01

    Full Text Available Monochromatic lights emitted by light-emitting diodes (LEDs have generated great interest for efficient and controlled growth in vitro, especially of plants which are endangered or require specific intensity and wavelength of light. In the present study, we have evaluated the effect of monochromatic LEDs on in vitro morphogenesis: growth, proliferation of shoot cultures, and rooting of Dendrobium sonia. Different light sources viz. white LEDs (W, blue LEDs (B, yellow LEDs (Y and red LEDs (R were tested under photoperiod of 16 h of exposure and 8 h of dark. The frequency of morphogenesis depended on the wavelength of the applied monochromatic light. Higher wavelength monochromatic light (yellow light was observed to induce higher shoot proliferation (98%, early PLB (protocorm-like bodies formation, differentiation into green buds and shoot initiation as compared to red, blue and white light treatments. Yellow light also yielded higher number of shoots per explants (29 shoots/explant than red, blue and white light treatments. The results suggest that the monochromatic light sources stimulate morphogenic effects on in vitro culture of Dendrobium sonia, and that yellow light treatment can be used to enhance the efficiency of micropropagation.

  17. Determination of the exposure speed of radiation emitted by the linear accelerator, using the code MCNP5 to evaluate the radiotherapy room shields of ABC Hospital

    International Nuclear Information System (INIS)

    Corral B, J. R.

    2015-01-01

    Humans should avoid exposure to radiation, because the consequences are harmful to health. Although there are different emission sources of radiation, generated by medical devices they are usually of great interest, since people who attend hospitals are exposed in one way or another to ionizing radiation. Therefore, is important to conduct studies on radioactive levels that are generated in hospitals, as a result of the use of medical equipment. To determine levels of exposure speed of a radioactive facility there are different methods, including the radiation detector and computational method. This thesis uses the computational method. With the program MCNP5 was determined the speed of the radiation exposure in the radiotherapy room of Cancer Center of ABC Hospital in Mexico City. In the application of computational method, first the thicknesses of the shields were calculated, using variables as: 1) distance from the shield to the source; 2) desired weekly equivalent dose; 3) weekly total dose equivalent emitted by the equipment; 4) occupation and use factors. Once obtained thicknesses, we proceeded to model the bunker using the mentioned program. The program uses the Monte Carlo code to probabilistic ally determine the phenomena of interaction of radiation with the shield, which will be held during the X-ray emission from the linear accelerator. The results of computational analysis were compared with those obtained experimentally with the detection method, for which was required the use of a Geiger-Muller counter and the linear accelerator was programmed with an energy of 19 MV with 500 units monitor positioning the detector in the corresponding boundary. (Author)

  18. Modern new nuclear fuel characteristics and radiation protection aspects.

    Science.gov (United States)

    Terry, Ian R

    2005-01-01

    The glut of fissile material from reprocessing plants and from the conclusion of the cold war has provided the opportunity to design new fuel types to beneficially dispose of such stocks by generating useful power. Thus, in addition to the normal reactor core complement of enriched uranium fuel assemblies, two other types are available on the world market. These are the ERU (enriched recycled uranium) and the MOX (mixed oxide) fuel assemblies. Framatome ANP produces ERU fuel assemblies by taking feed material from reprocessing facilities and blending this with highly enriched uranium from other sources. MOX fuel assemblies contain plutonium isotopes, thus exploiting the higher neutron yield of the plutonium fission process. This paper describes and evaluates the gamma, spontaneous and alpha reaction neutron source terms of these non-irradiated fuel assembly types by defining their nuclear characteristics. The dose rates which arise from these terms are provided along with an overview of radiation protection aspects for consideration in transporting and delivering such fuel assemblies to power generating utilities.

  19. Electron Microscopy Study of Stainless Steel Radiation Damage Due to Long-Term Irradation by Alpha Particles Emitted From Plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Unlu, Kenan [Univ. of Texas, Austin, TX (United States); Rios-Martinez, Carlos [Univ. of Texas, Austin, TX (United States); Saglam, Mehmet [Univ. of Texas, Austin, TX (United States); Hart, Ron R. [Texas A & M Univ., College Station, TX (United States); Shipp, John D. [Texas A & M Univ., College Station, TX (United States); Rennie, John [Texas A & M Univ., College Station, TX (United States)

    1998-04-16

    Radiation damage and associated surface and microstructural changes produced in stainless steel encapsulation by high-fluence alpha particle irradiations from weapons-grade plutonium of 316-stainless steel are being investigated.

  20. Simple method for routine check of the constancy of radiation quality of bremsstrahlung emitted by therapeutic particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Rassow, J; Eipper, H H; Krause, K [Essen Univ. (Gesamthochschule) (Germany, F.R.). Abt. fuer Klinische Strahlenphysik; Staedtisches Krankenhaus Koeln-Merheim (Germany, F.R.). Roentgeninstitut und Strahlenklinik)

    1977-05-01

    The constancy of the radiation quality of therapeutically employed particle accelerators has to be checked at weekly intervals. Any change in radiation quality may have considerable therapeutic effects owing to its influence on dose distribution. It is recommended that measurements be made instead of, or in addition to, the axial reference-point measurement at 5 and 15 cm depth in the phantom, at 5 cm depth in the beam axis and at a reference-point about 1 cm within the geometric edge of the field, for checking the constancy of the radiation quality of bremsstrahlung. Only then, if routine checks carried out for the axial and the lateral reference-point dose ratios do not show any deviations greater than e.g. +-2 %, radiation quality is deemed to have remained sufficiently constant for radiotherapeutical applications.

  1. Interaction between the radiative flux emitted by a corium melt and aerosols from corium/concrete interaction

    Energy Technology Data Exchange (ETDEWEB)

    Zabiego, M.; Cognet, G. [CEA-DRN/DER/SERA - CE Cadarache, Saint-Paul-Lez-Durance (France); Henderson, D. [Univ. of Wisconsin, Madison, WI (United States)

    1995-09-01

    In this paper we present a one-dimensional numerical model that deals with radiative transfer in a medium where aerosols are present. This model is written with the aim of performing radiative transfer calculations in the framework of severe Pressurized Water Reactor accidents, especially during the last stage of such an accident Molten Core Concrete Interaction (MCCI) when aerosols are very numerous. We explain the theoretical basis of our model, writing the general radiative transfer equation, knowing that aerosol droplets participate in radiation transport. We then simplify this equation for a one-dimensional medium and we propose to solve it using the spherical harmonics approximation. This gives us the radiative intensity and we can then deduce the radiative flux. Aerosol optical properties (extinction and scattering coefficients) are also required in such a calculation. They are determined using Rayleigh or Mie theory, depending, depending on the aerosol size. In order to provide an example of results one can expect from such a calculation, we applied our model to a test problem with given aerosol size and concentration distributions. Our example does not model any experiment explicitly but the physical conditions used are very close to the L4 test from the Advanced Containment Experiment (ACE) program.

  2. Fundamental Characteristics of Deep-UV Light-Emitting Diodes and Their Application To Control Foodborne Pathogens

    Science.gov (United States)

    Shin, Joo-Yeon; Kim, Soo-Ji; Kim, Do-Kyun

    2015-01-01

    Low-pressure mercury UV (LP-UV) lamps have long been used for bacterial inactivation, but due to certain disadvantages, such as the possibility of mercury leakage, deep-UV-C light-emitting diodes (DUV-LEDs) for disinfection have recently been of great interest as an alternative. Therefore, in this study, we examined the basic spectral properties of DUV-LEDs and the effects of UV-C irradiation for inactivating foodborne pathogens, including Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes, on solid media, as well as in water. As the temperature increased, DUV-LED light intensity decreased slightly, whereas LP-UV lamps showed increasing intensity until they reached a peak at around 30°C. As the irradiation dosage and temperature increased, E. coli O157:H7 and S. Typhimurium experienced 5- to 6-log-unit reductions. L. monocytogenes was reduced by over 5 log units at a dose of 1.67 mJ/cm2. At 90% relative humidity (RH), only E. coli O157:H7 experienced inactivation significantly greater than at 30 and 60% RH. In a water treatment study involving a continuous system, 6.38-, 5.81-, and 3.47-log-unit reductions were achieved in E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, at 0.5 liter per minute (LPM) and 200 mW output power. The results of this study suggest that the use of DUV-LEDs may compensate for the drawbacks of using LP-UV lamps to inactivate foodborne pathogens. PMID:26162872

  3. Fundamental Characteristics of Deep-UV Light-Emitting Diodes and Their Application To Control Foodborne Pathogens.

    Science.gov (United States)

    Shin, Joo-Yeon; Kim, Soo-Ji; Kim, Do-Kyun; Kang, Dong-Hyun

    2016-01-01

    Low-pressure mercury UV (LP-UV) lamps have long been used for bacterial inactivation, but due to certain disadvantages, such as the possibility of mercury leakage, deep-UV-C light-emitting diodes (DUV-LEDs) for disinfection have recently been of great interest as an alternative. Therefore, in this study, we examined the basic spectral properties of DUV-LEDs and the effects of UV-C irradiation for inactivating foodborne pathogens, including Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes, on solid media, as well as in water. As the temperature increased, DUV-LED light intensity decreased slightly, whereas LP-UV lamps showed increasing intensity until they reached a peak at around 30°C. As the irradiation dosage and temperature increased, E. coli O157:H7 and S. Typhimurium experienced 5- to 6-log-unit reductions. L. monocytogenes was reduced by over 5 log units at a dose of 1.67 mJ/cm(2). At 90% relative humidity (RH), only E. coli O157:H7 experienced inactivation significantly greater than at 30 and 60% RH. In a water treatment study involving a continuous system, 6.38-, 5.81-, and 3.47-log-unit reductions were achieved in E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, at 0.5 liter per minute (LPM) and 200 mW output power. The results of this study suggest that the use of DUV-LEDs may compensate for the drawbacks of using LP-UV lamps to inactivate foodborne pathogens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. Fluctuation characteristics of solar radiation in crop cultivation

    International Nuclear Information System (INIS)

    Hayashi, S.; Suzuki, H.

    1996-01-01

    The objective of this study was to clarify the fluctuation of solar radiation for long and short periods, which is very crucial for plant growth. Data obtained from a meteorological observatory were used to investigate solar radiation and sunshine duration for a long period. For a short period, observation of global solar radiation and sky solar radiation were conducted in a glass house and at an open field. (1) Yearly average percentage of solar radiation at Kagawa from 1973 to 1994 was 44.3%, and its coefficient of variation was 3.9%. The percentage of possible sunshine and the coefficient were larger than those of solar radiation, 47.3% and 56% respectively. (2) Percentage of possible solar radiation and percentage of possible sunshine showed seasonal variation. Those coefficients of variation both increased exponentially with cloud amount. (3) Variations of global solar radiation and direct solar radiation were more remarkable in the glass house than those in the open field, while variations of sky solar radiation were small in the house and at the open field. (4) The fluctuation of solar radiation observed every 5 minutes was presented as the difference of radiation, present value minus the preceding value. The difference was positive in the morning, negative in the afternoon at the open field. In the house both positive and negative values were obtained the whole day. (5) Diurnal variation of ratio of direct solar radiation to sky solar radiation showed a parabolic effect, whereas it had irregular and large fluctuations at the open field

  5. Determination of gamma radiation shielding characteristics of some tropical woods

    International Nuclear Information System (INIS)

    Aigbosuria, E. F.

    2011-01-01

    This study compares the shielding characteristics of twenty-two tropical woods by using gamma scintillation detection method. Woods sourced are Anogeisus Leiocarpus(Ayin), Nesogordonia Papverifera(Oro), Entandrophragma Microphyllum(Anunje), Brachystagia Eurycoma(Ako), Cassia Alata(Asunrun), Afzelia Africana(Apa-Igbo), Khaya Grandifoliala(Gedu), Piptadenistrum Africana(Agbonyin), Nanclea Diderrehii(Opepe), Khaya Ivorensis(Oganwo), Chlorophora Excelsa(Iroko), Masonia altissima(Odogi), Entandrophragma Angolense(Ijebo), Altium Sativum(Ayo), Albizia Zygia(Ayunre), Terminalia Superba(Afara), Cordia Millenii(Omo), Melania(Melania), Pycnanthus Angolensis(Akomu), Triplochitons Scleroxylon(Arere), Pine(Pine), Ceiba Pentradra(Araba). The intensities of the emergent radiation were measured, when each of these woods were placed between a scintillation detector and a standard radioactive source. Analysis of result obtained shows an appreciable evidence of radiation attenuation due to the changes in the chemical composition of the woods and the dependence of the attenuation coefficient on energy and densities of these woods. The descending order of attenuation coefficient determined are; Ayin, Oro, Anuje, Ako, Asunrun, Apa-igbo Gedu, Agbonyin, Opepe Oganwo, Iroko Odogi , Ayo, Ayunre, Afara, Omo, Melania, Akomu, Arere, Pine, Araba. For a constant energy of 0.101MeV, the attenuation coefficient are 0.190cm -1 , 0.165cm -1 , 0.163cm -1 , 0.156cm -1 , 0.149cm -1 , 0.143cm -1 , 0.133cm -1 , 0.132cm -1 , 0.127cm -1 , 0.124cm -1 , 0.085cm -1 , 0.123cm -1 , 0.122cm -1 , 0.113cm -1 , 0.101cm -1 , 0.088cm -1 , 0.087cm -1 , 0.086cm -1 , 0.082cm -1 respectively. The wood in descending order of dependence of attenuation coefficient on density are: Ayin,Oro, Anunje,Ako,Asunrun,Apa-Igbo, Gedu, Agbonyin, Opepe, Oganwo, Iroko, Odogi, Ijebo, Ayo, Ayunre, Afara, Omo, Melania, Akomu, Arere, Pine and Araba. The half value layer shows the thickness at various energy regions.

  6. Determination of gamma radiation shielding characteristics of some tropical woods

    Energy Technology Data Exchange (ETDEWEB)

    Aigbosuria, E F [Department of Computer Electronics/Physics, Lead City University, Ibadan (Nigeria)

    2011-10-24

    This study compares the shielding characteristics of twenty-two tropical woods by using gamma scintillation detection method. Woods sourced are Anogeisus Leiocarpus(Ayin), Nesogordonia Papverifera(Oro), Entandrophragma Microphyllum(Anunje), Brachystagia Eurycoma(Ako), Cassia Alata(Asunrun), Afzelia Africana(Apa-Igbo), Khaya Grandifoliala(Gedu), Piptadenistrum Africana(Agbonyin), Nanclea Diderrehii(Opepe), Khaya Ivorensis(Oganwo), Chlorophora Excelsa(Iroko), Masonia altissima(Odogi), Entandrophragma Angolense(Ijebo), Altium Sativum(Ayo), Albizia Zygia(Ayunre), Terminalia Superba(Afara), Cordia Millenii(Omo), Melania(Melania), Pycnanthus Angolensis(Akomu), Triplochitons Scleroxylon(Arere), Pine(Pine), Ceiba Pentradra(Araba). The intensities of the emergent radiation were measured, when each of these woods were placed between a scintillation detector and a standard radioactive source. Analysis of result obtained shows an appreciable evidence of radiation attenuation due to the changes in the chemical composition of the woods and the dependence of the attenuation coefficient on energy and densities of these woods. The descending order of attenuation coefficient determined are; Ayin, Oro, Anuje, Ako, Asunrun, Apa-igbo Gedu, Agbonyin, Opepe Oganwo, Iroko Odogi , Ayo, Ayunre, Afara, Omo, Melania, Akomu, Arere, Pine, Araba. For a constant energy of 0.101MeV, the attenuation coefficient are 0.190cm{sup -1}, 0.165cm{sup -1}, 0.163cm{sup -1}, 0.156cm{sup -1}, 0.149cm{sup -1}, 0.143cm{sup -1}, 0.133cm{sup -1}, 0.132cm{sup -1}, 0.127cm{sup -1}, 0.124cm{sup -1}, 0.085cm{sup -1}, 0.123cm{sup -1}, 0.122cm{sup -1}, 0.113cm{sup -1}, 0.101cm{sup -1}, 0.088cm{sup -1}, 0.087cm{sup -1}, 0.086cm{sup -1}, 0.082cm{sup -1} respectively. The wood in descending order of dependence of attenuation coefficient on density are: Ayin,Oro, Anunje,Ako,Asunrun,Apa-Igbo, Gedu, Agbonyin, Opepe, Oganwo, Iroko, Odogi, Ijebo, Ayo, Ayunre, Afara, Omo, Melania, Akomu, Arere, Pine and Araba. The half value

  7. Reverse leakage current characteristics of InGaN/GaN multiple quantum well ultraviolet/blue/green light-emitting diodes

    Science.gov (United States)

    Zhou, Shengjun; Lv, Jiajiang; Wu, Yini; Zhang, Yuan; Zheng, Chenju; Liu, Sheng

    2018-05-01

    We investigated the reverse leakage current characteristics of InGaN/GaN multiple quantum well (MQW) near-ultraviolet (NUV)/blue/green light-emitting diodes (LEDs). Experimental results showed that the NUV LED has the smallest reverse leakage current whereas the green LED has the largest. The reason is that the number of defects increases with increasing nominal indium content in InGaN/GaN MQWs. The mechanism of the reverse leakage current was analyzed by temperature-dependent current–voltage measurement and capacitance–voltage measurement. The reverse leakage currents of NUV/blue/green LEDs show similar conduction mechanisms: at low temperatures, the reverse leakage current of these LEDs is attributed to variable-range hopping (VRH) conduction; at high temperatures, the reverse leakage current of these LEDs is attributed to nearest-neighbor hopping (NNH) conduction, which is enhanced by the Poole–Frenkel effect.

  8. Changes in the performance characteristics of a GaAs near infrared light emitting diode when exposed to various current and thermal stresses

    Science.gov (United States)

    Thomas, E. F., Jr.

    1974-01-01

    The changes that occurred in the optical and electrical characteristics of a near infrared, GaAs light emitting diode, when operated under various levels and combinations of current and thermal stresses are discussed. A total of forty parts were operated for two thousand hours under eight different sets of dc current and ambient temperature conditions. Degradation in the radiant optical power of these devices was thirty-four percent when operated at their rated current and an ambient temperature of 298K (25 C). Derating the current and/or the thermal stress reduced the degradation of this parameter in approximately a linear manner. All degraded devices behaved similarly, exhibiting rapid nonlinear degradation followed by a gradual linear degradation and finally a period of stable operation. An attempt was made to correlate initial device condition to degradation during stress testing, but met with little success.

  9. Simulation of Thermal, Neutronic and Radiation Characteristics in Spent Nuclear Fuel and Radwaste Facilities

    International Nuclear Information System (INIS)

    Poskas, P.; Bartkus, G.

    1999-01-01

    The overview of the activities in the Division of Thermo hydro-mechanics related with the assessment of thermal, neutronic and radiation characteristics in spent nuclear fuel and radwaste facilities are performed. Also some new data about radiation characteristics of the RBMK-1500 spent nuclear fuel are presented. (author)

  10. Drying characteristics of rough rice by far-infrared radiation heating

    International Nuclear Information System (INIS)

    Matsuoka, T.

    1990-01-01

    The relationship between the heat radiation characteristics of a far-infrared radiation heater and the drying characteristics of rough rice was investigated to determine the basic data required for utilization of far-infrared rays for drying rough rice. Results of investigations are discussed in detail

  11. Characteristics of polycyclic aromatic hydrocarbons in PM2.5 emitted from different cooking activities in China.

    Science.gov (United States)

    Li, Yun-Chun; Qiu, Jia-Qian; Shu, Man; Ho, Steven Sai Hang; Cao, Jun-Ji; Wang, Ge-Hui; Wang, Xian-Xiang; Zhao, Xiao-Qing

    2018-02-01

    Nineteen polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 emitted from five different cooking activities were characterized, and their influencing factors were determined. The total quantified particle-bounded PAH concentrations (ΣPAHs) in the airs from the cooking activities were 4.2-36.5-fold higher than those in corresponding backgrounds. The highest ΣPAHs were seen in cafeteria frying (783 ± 499 ng/m 3 ), followed by meat roasting (420 ± 191 ng/m 3 ), fish roasting (210 ± 105 ng/m 3 ), snack-street boiling (202 ± 230 ng/m 3 ), and cafeteria boiling (150 ± 65 ng/m 3 ). The main influencing factors on the PAH emissions were cooking methods, fat contents in raw materials, and oil consumptions. Four- to six-ringed PAHs had the highest contributions to the ΣPAHs (avg. 87.5%). Diagnostic ratios of individual PAH were similar between the two charbroiling and other three conventional Chinese cooking methods, respectively, demonstrating the dominance of cooking methods in the PAH emissions. Remarkably high benzo(b)fluoranthene/benzo(k)fluoranthene (BbF/BkF) ratio (8.31) was seen in the snack-street boiling, attributed to the coal combustion as cooking fuel. Both fluoranthene/(fluoranthene + pyrene) [FLT/(FLT + PYR)] and benzo(a)anthracene/(benzo(a)anthracene + chrysene) [BaA/(BaA + CHR)] ratios were higher for the oil-based cooking than those from the water-based ones. In addition, two ratios of indeno(1,2,3-cd)pyrene/(indeno(1,2,3-cd)pyrene + benzo(g,h,i)perylene) [IPY/(IPY + BPE)] and benzo(a)pyrene/(benzo(a)pyrene + benzo(g,h,i)perylene) [BaP/(BaP + BPE)] were higher for two charbroiling than the three conventional Chinese cooking methods. The characterization work in this study is particularly important since cooking is a potential contributor of atmospheric PAHs in urban China. Carcinogenic potencies of PAHs were assessed by comparison with the air quality guideline and health risk estimation. The BaP and BaP equivalent were

  12. Radiators in hydronic heating installations structure, selection and thermal characteristics

    CERN Document Server

    Muniak, Damian Piotr

    2017-01-01

    This book addresses key design and computational issues related to radiators in hydronic heating installations. A historical outline is included to highlight the evolution of radiators and heating technologies. Further, the book includes a chapter on thermal comfort, which is the decisive factor in selecting the ideal heating system and radiator type. The majority of the book is devoted to an extensive discussion of the types and kinds of radiators currently in use, and to identifying the reasons for the remarkable diversity of design solutions. The differences between the solutions are also addressed, both in terms of the effects of operation and of the thermal comfort that needs to be ensured. The book then compares the advantages and disadvantages of each solution, as well as its potential applications. A detailed discussion, supported by an extensive theoretical and mathematical analysis, is presented of the computational relations that are used in selecting the radiator type. The dynamics of radiator hea...

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

    International Nuclear Information System (INIS)

    Lotfi, S.A.

    2011-01-01

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

  14. Effect of radiation on microbiologic characteristics of M. tuberculosis

    International Nuclear Information System (INIS)

    Zack, M.B.; Stottmeier, K.; Berg, G.; Kazemi, H.

    1974-01-01

    The effect of irradiation on mutation (expressing itself as drug resistance) and on viability of Mycobacterium tuberculosis was studied in vitro. Forty-two identical cultures of H37-Rv (M. tuberculosis) were exposed to different levels of cobalt radiation (10, 100, 1,000, 2,500, 5,000, 10,000, and 20,000 rads) with six samples used for each of the seven radiation levels. Equivalent samples exposed to zero rads and samples handled and stored identically formed the controls. Coded cultures were read in a double-blind fashion to determine the number of surviving organisms and sensitivities to nine different antituberculosis drugs. Organism viability began to decrease at radiation levels of 1,000 rads and decreased linearly with higher levels of radiation. Three of the 42 radiated cultures developed drug-resistant organisms (one to INH, one to PAS, a third to SM). This drug resistance occurred at levels of clinical significance (greater than 1 percent control) as well as in amounts exceeding probability values for chance resistance mutation. High radiation levels such as occur in radiotherapeutic doses decrease the viability of M. tuberculosis. Radiation may also induce genetic mutation expressed as primary drug resistance. (U.S.)

  15. The electronics in fluorescent bulbs and light emitting diodes (LED), rather than ultraviolet radiation, cause increased malignant melanoma incidence in indoor office workers and tanning bed users.

    Science.gov (United States)

    Milham, Samuel; Stetzer, Dave

    2018-07-01

    The epidemiology of cutaneous malignant melanoma (CMM) has a number of facets that do not fit with sunlight and ultraviolet light as the primary etiologic agents. Indoor workers have higher incidence and mortality rates of CMM than outdoor workers; CMM occurs in body locations never exposed to sunlight; CMM incidence is increasing in spite of use of UV blocking agents and small changes in solar radiation. Installation of two new fluorescent lights in the milking parlor holding area of a Minnesota dairy farm in 2015 caused an immediate drop in milk production. This lead to measurement of body amperage in humans exposed to modern non-incandescent lighting. People exposed to old and new fluorescent lights, light emitting diodes (LED) and compact fluorescent lights (CFL) had body amperage levels above those considered carcinogenic. We hypothesize that modern electric lighting is a significant health hazard, a carcinogen, and is causing increasing CMM incidence in indoor office workers and tanning bed users. These lights generate dirty electricity (high frequency voltage transients), radio frequency (RF) radiation, and increase body amperage, all of which have been shown to be carcinogenic. This could explain the failure of ultraviolet blockers to stem the malignant melanoma pandemic. Tanning beds and non-incandescent lighting could be made safe by incorporating a grounded Faraday cage which allows passage of ultraviolet and visible light frequencies and blocks other frequencies. Modern electric lighting should be fabricated to be electrically clean. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Shielding Efficiency of a Fabric Based on Amorphous Glass-Covered Magnetic Microwires to Radiation Emitted by a Mobile Phone in 2G and 3G Communication Technologies

    Directory of Open Access Journals (Sweden)

    Miclăuş Simona

    2017-12-01

    Full Text Available A dual band mobile phone model was used to check the shielding properties of an amorphous ferromagnetic textile against the radiation emitted by the handset. Two frequencies belonging to the 2nd and 3rd generation of mobile emission technologies were used, 897 MHz and 1950 MHz. The specific absorption rate (SAR of energy deposition in a human head phantom was measured in standardized conditions. The textile contained micrometric-diameter wires of a ferromagnetic mixture embedded in a thin glass coat and weaved in a specific way. A set of fabric orientations and configurations (layering were provided in the experiment in order to achieve a better shielding to the phone’s radiation. Compared with the non-shielded handset, SAR deposited in the head while using the fabric-covered phone could be decreased up to 30 % of its initial value – in case of 2G technology and up to 24 % – in case of 3G technology. This type of material shows one of the highest shielding efficiencies of the electric-field component in near-field exposure conditions reported until now. A cubic curve of SAR decrease in depth of the head was revealed in both uncovered and covered handset, the effect of shielding being larger at the higher frequency.

  17. Instrument development for atmospheric radiation measurement (ARM): Status of the Atmospheric Emitted Radiance Interferometer - extended Resolution (AERI-X), the Solar Radiance Transmission Interferometer (SORTI), and the Absolute Solar Transmission Inferometer (ASTI)

    Energy Technology Data Exchange (ETDEWEB)

    Murcray, F.; Stephen, T.; Kosters, J. [Univ. of Denver, CO (United States)

    1996-04-01

    This paper describes three instruments currently under developemnt for the Atmospheric Radiation Measurement (ARM) Program at the University of Denver: the AERI-X (Atmospheric Emitted Radiance Interferometer-Extended Resolution) and the SORTI (Solar R adiance Transmission Interferometer), and ASTI (Absolute Solar transmission Interferometer).

  18. Ultraviolet-B radiation effects on leaf fluorescence characteristics in cultivars of soybean

    International Nuclear Information System (INIS)

    Miles, D.

    1993-01-01

    Ultraviolet-B (UV-B; 280–320 nm)–emitting lamps unavoidably emit ultraviolet-A (UV-A; 320–400 nm) and ultraviolet-C (UV-C; <280 nm) radiation. Short-wavelength–blocking filters are generally used to limit the wave bands of UV under investigation. The widespread use of such filters means that all exposures to UV-B radiation will have a significant UV-A component. Therefore, the physiological effects unique to UV-B exposure are difficult to clearly isolate. This study presents a method to remove the UV-A and UV-C “contamination” using a liquid potassium chromate (K 2 CrO 4 ) filter, thus allowing more direct assessment of the effects of UV-B exposure. Cultures of the green marine alga Dunaliella tertiolecta were grown in the absence of UV radiation. Sunlamps supplied the UV radiation for a 24 h exposure (solar radiation was not used in this study). The UV radiation was filtered either by the standard method (i.e. cellulose acetate (CA) with polyester = Mylar controls) or by a liquid filter of potassium chromate. Photosynthetic responses were compared. Major decreases in the ratio of variable to maximal fluorescence in dark-adapted cells and photosynthetic capacity were observed in CA-filtered cultures, whereas no change was observed in cells exposed to the same UV-B flux with the UV-A removed by K 2 CrO 4 . The use of a CA filter with a Mylar control does not link results unequivocally to UV-B radiation. Such results should be interpreted with caution. (author)

  19. Effects of plasma polymerized para-xylene intermediate layers on characteristics of flexible organic light emitting diodes fabricated on polyethylene terephthalate substrates

    International Nuclear Information System (INIS)

    Sohn, Sunyoung; Kim, Kyuhyung; Kho, Samil; Jung, Donggeun; Boo, Jin-hyo

    2008-01-01

    Characteristics of flexible organic light emitting diodes (FOLEDs) with the plasma polymerized para-xylene (PPpX) intermediate layer were investigated. For the purpose of reducing moisture permeation through plastic substrates, a PPpX intermediate layer was inserted between FOLEDs and the plastic substrates. As the concentration of C-H bonding in the PPpX film deposited at 25 deg. C was increased, PPpX films showed increased transmittance. Surface morphologies of polyethylene terephthalate (PET) covered with the PPpX intermediate layer were improved compared to PET without PPpX on it. Due to the highly cross-linked network structure in the plasma polymer film, water vapor permeability of PET substrates with the PPpX intermediate layer of 75 nm was decreased compared to PET substrates without PPpX on it. FOLEDs with the PPpX intermediate layer showed improved optical and electrical characteristics as well as lifetimes than FOLEDs without the PPpX intermediate layer

  20. [Occupational exposure of welders to ultraviolet and "blue light" radiation emitted during TIG and MMA welding based on field measurements].

    Science.gov (United States)

    Wolska, Agnieszka

    2013-01-01

    The aim of the study was to present the results of welders' occupational exposure to "blue light" and UV radiation carried out at industrial workstations during TIG and MMA welding. Measurements were performed at 13 workstations (TIG welding: 6; MMA welding: 7), at which different welding parameters and materials were used. The radiation level was measured using a wide-range radiometer and a set of detectors, whose spectral responses were adequately fit to particular hazard under study. The measurement points corresponded with the location of eye and hand. The highest values of eye irradiance were found for aluminum TIG welding. Effective irradiance of actinic UV was within the range E(s) = 7.79-37.6 W/m2; UVA total irradiance, E(UVA) = 18-53.1 W/m2 and effective blue-light irradiance E(B) = 35-67 W/m2. The maximum allowance time ranged from 1.7 to 75 s, which means that in some cases even unintentional very short eye exposure can exceed MPE. The influence of welded material and the type of electrode coating on the measured radiation level were evidenced. The exceeded value of MPE for photochemical hazard arising for the eyes and skin was found at all measured workstations. Welders should use appropriately the eye and face protective equipment and avoid direct staring at welding arc when starting an arc-welding operation. Besides, the lack of head and neck skin protection can induce acute and chronic harmful health effects. Therefore, an appropriate wear of personal protective equipment is essential for welders' health.

  1. Occupational exposure of welders to ultraviolet and "blue light" radiation emitted during TIG and MMA welding based on field measuremants

    Directory of Open Access Journals (Sweden)

    Agnieszka Wolska

    2013-02-01

    Full Text Available Background: The aim of the study was to present the results of welders' occupational exposure to "blue light" and UV radiation carried out at industrial workstations during TIG and MMA welding. Materials and methods: Measurements were performed at 13 workstations (TIG welding: 6; MMA welding: 7, at which different welding parameters and materials were used. The radiation level was measured using a wide-range radiometer and a set of detectors, whose spectral responses were adequately fit to particular hazard under study. The measurement points corresponded with the location of eye and hand. Results: The highest values of eye irradiance were found for aluminum TIG welding. Effective irradiance of actinic UV was within the range Es = 7.79-37.6 W/m2; UVA total irradiance, EUVA = 18-53.1 W/m2 and effective blue-light irradiance EB = 35-67 W/m2. The maximum allowance time ranged from 1.7 to 75 s, which means that in some cases even unintentional very short eye exposure can exceed MPE. Conclusions: The influence of welded material and the type of electrode coating on the measured radiation level were evidenced. The exceeded value of MPE for photochemical hazard arising for the eyes and skin was found at all measured workstations. Welders should use appropriately the eye and face protective equipment and avoid direct staring at welding arc when starting an arcwelding operation. Besides, the lack of head and neck skin protection can induce acute and chronic harmful health effects. Therefore, an appropriate wear of personal protective equipment is essential for welders' health. Med Pr 2013;64(1:69–82

  2. Clinico-morphological characteristics of reparation of acute radiation ulcer

    International Nuclear Information System (INIS)

    Petrik, V.D.; Yakovleva, N.D.; Bardychev, M.S.

    1979-01-01

    The mechanism of reparative processes under the effect of various drugs was studied in experimental acute radiation ulcer of rats. It was established that at the stage of marked exudative-necrotic processes the use of antiinflammatory and antiexudative substances (bariz, dimethylsulfoxyde) led to normalization of the microcirculation that reduced the time of radiation ulcer healing. The use of anabolic steroids (retabolil) intensified metabolism that also produced a favourable effect on the reparative processes

  3. Radiation Effects on Thermoluminescence Characteristics of HDPE Containing Additives

    International Nuclear Information System (INIS)

    Kim, Ki Yup; Lee, Chung; Ryu, Boo Hyung

    2005-01-01

    Polymeric materials are widely used for electrical insulation in a broad range of applications that cover the power supply industry to inner and outer space. However, the electrical performance of these materials could be compromised by their working environment and one of the most deleterious is that where a nuclear radiation is present. Radiation effects on polymers can be interpreted by two main reactions, a cross-linking reaction and degradation reactions or a main-chain scission process. There are no absolute rules for determining whether or not any given polymer will cross-link or degrade upon an irradiation. But, the polymers can be divided empirically into two groups; polymers which are crosslinked by radiation (especially by the incorporation of chemical cross-linking promoters) and polymers which degrade by radiation into a product of lower molecular weight due to random main-chain scission process. These polymers become very hard and brittle with a high dose of radiation. Most polymeric materials contain some stabilizers such as flame retardant and antioxidant to prevent combustion and oxidation. Because of these additives, degradation mechanism of the polymer became complicated. Many of the novel properties of the insulating materials used in nuclear power plants are important for radiation degradation. Therefore we have used the thermal methods such as thermoluminescence (TL) detection for irradiated high density polyethylene containing flame retardant and antioxidant

  4. Noise characteristics of U. S. synchrotron radiation sources

    International Nuclear Information System (INIS)

    Powers, L.

    1986-01-01

    Noise characteristics of the U. S. x-ray synchrotron sources are compared in the 0--2.5-kHz region. In general, little difference is found in the characteristic frequencies of the noise on focused and unfocused beamlines of a particular source, but the magnitude and white-noise levels differ. The National Synchrotron Light Source shows the least characteristic noise and the noise that is observed is small in magnitude (2--3 times the white-noise level)

  5. Phase radiation characteristics of an open-ended circular waveguide

    DEFF Research Database (Denmark)

    Shishkova, Anna; Pivnenko, Sergey; Kim, Oleksiy S.

    2007-01-01

    General analytical expressions are derived for the far-field amplitude and phase radiation patterns of an open-ended circular waveguide (OE-CWG) regardless of its radius or the operation frequency for the dominant and symmetric higher-order excitation modes. The derivation is based on the rigorous...... solution to the problem of diffraction at an open end of a waveguide proposed by Weinstein. The near-field amplitude and phase patterns of an OE-CWG are then calculated using the spherical wave expansion technique. The measurement of the radiation pattern of an OE-CWG was carried out to verify the validity...

  6. A characteristic scale in radiation fields of fractal clouds

    Energy Technology Data Exchange (ETDEWEB)

    Wiscombe, W.; Cahalan, R.; Davis, A.; Marshak, A. [Goddard Space Flight Center, Greenbelt, MD (United States)

    1996-04-01

    The wavenumber spectrum of Landsat imagery for marine stratocumulus cloud shows a scale break when plotted on a double log plot. We offer an explanation of this scale break in terms of smoothing by horizontal radiative fluxes, which is parameterized and incorporated into an improved pixel approximation. We compute the radiation fields emerging from cloud models with horizontally variable optical depth fractal models. We use comparative spectral and multifractal analysis to qualify the validity of the independent pixel approximation at the largest scales and demonstrate it`s shortcomings on the smallest scales.

  7. 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)

  8. Synchrotron radiation : characteristics and application in structural studies and phase transformations of materials

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1984-01-01

    The main characteristics of the synchrotron radiation for studying atomic structure and phase transformations in materials are presented. Some specific applications in alloys, glass and solids are described. (E.G.) [pt

  9. Aerodynamic characteristics and heat radiation performance of sportswear fabrics

    Science.gov (United States)

    Koga, H.; Hiratsuka, M.; Ito, S.; Konno, A.

    2017-10-01

    Sports such as swimming, speed skating, and marathon are sports competing for time. In recent years, reduction of the fluid drag of sportswear is required for these competitions in order to improve the record. In addition, sweating and discomfort due to body temperature rise during competition are thought to affect competitor performance, and heat radiation performance is also an important factor for sportswear. The authors have measured fluid force drag by wrapping cloth around a cylinder and have confirmed their differences due to the roughness of the fabric surface, differences in sewing. The authors could be verified the drag can be reduced by the position of the wear stitch. This time, we measured the heat radiation performance of 14 types of cloths whose aero dynamic properties are known using cylinders which are regarded as human fuselages, and found elements of cloth with heat radiation performance. It was found to be important for raising the heat radiation performance of sportswear that the fabric is thin and flat surface processing.

  10. Characteristics of long-term consequences of acute radiation sickness

    International Nuclear Information System (INIS)

    Kovalenko, A.N.; Belyj, D.A.; Bebeshko, V.G.

    2000-01-01

    In persons who suffered from acute radiation sickness (ARS) as a result of the Chernobyl accident in course of time there are revealed the stochastic and non-stochastic effects of irradiation both in 'critical' and 'non-critical' organism systems. It is connected with maintenance of somatic mutation high level and steady changes in membranes subcellular structures, biomolecules as well as metabolic disturbances. Stable changes of hemopoietic and immune system indexes have to be considered as pre-pathological status with high hazard of stochastic effects development. Frequency rate of typical radiation cataracts (posterior subcapsular) is correlated with ARS severity degree; fundus oculi vessel pathology have essential weight in total eye pathology. Chronic radiation dermatitis is an important clinical problem being a long-term consequence of irradiation. It demands a constant attention in order to prevent trophic secondary skin lesions. Radiation damage of eye and skin as well as high frequency of chronic somatic diseases and neuropsychiatric disorders conditioned the high level of disablement in ARS-patients

  11. Non-ionizing radiations : physical characteristics, biological effects and health hazard assessment

    International Nuclear Information System (INIS)

    Repacholi, M.H.

    1988-01-01

    The Workshop was a project of the International Non-Ionizing Radiation Committee of IRPA and comprised a series of educational lectures and demonstrations intended to give a comprehensive overview of non-ionizing electromagnetic radiation: physical characteristics, sources of concern, levels of exposure, mechanisms of interaction and reported effects of these fields and radiations with biological tissues, human studies, health risk assessment, national and international standards and guidelines, and protective measures

  12. Current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation

    Directory of Open Access Journals (Sweden)

    N Hatefi Kargan

    2013-09-01

    Full Text Available  In this paper, current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation has been calculated and compared with the results when there is no electromagnetic radiation. For calculating current -voltage characteristic, it is required to calculate the transmission coefficient of electrons from the well and barrier structures of this device. For calculating the transmission coefficient of electrons at the presence of electromagnetic radiation, Finite Difference Time Domain (FDTD method has been used and when there is no electromagnetic radiation Transfer Matrix Method (TMM and finite diffirence time domain method have been used. The results show that the presence of electromagnetic radiation causes resonant states other than principal resonant state (without presence of electromagnetic radiation to appear on the transmition coefficient curve where they are in distances from the principal peak and from each other. Also, the presence of electromagnetic radiation causes peaks other than principal peak to appear on the current-voltage characteristics of the device. Under electromagnetic radiation, the number of peaks on the current-voltage curve is smaller than the number of peaks on the current-voltage transmission coefficient. This is due to the fact that current-voltage curve is the result of integration on the energy of electrons, Thus, the sharper and low height peaks on the transmission coefficient do not appear on the current-voltage characteristic curve.

  13. Aging characteristics of blue InGaN micro-light emitting diodes at an extremely high current density of 3.5 kA cm−2

    International Nuclear Information System (INIS)

    Tian, Pengfei; Liu, Ran; Althumali, Ahmad; Gu, Erdan; Watson, Ian M; Dawson, Martin D

    2016-01-01

    The aging characteristics of blue InGaN micro-light emitting diodes (micro-LEDs) with different sizes have been studied at an extremely high current density 3.5 kA cm −2 for emerging micro-LED applications including visible light communication (VLC), micro-LED pumped organic lasers and optogenetics. The light output power of micro-LEDs first increases and then decreases due to the competition of Mg activation in p-GaN layer and defect generation in the active region. The smaller micro-LEDs show less light output power degradation compared with larger micro-LEDs, which is attributed to the lower junction temperature of smaller micro-LEDs. It is found that the high current density without additional junction temperature cannot induce significant micro-LED degradation at room temperature but the combination of the high current density and high junction temperature leads to strong degradation. Furthermore, the cluster LEDs, composed of a micro-LED array, have been developed with both high light output power and less light output degradation for micro-LED applications in solid state lighting and VLC. (paper)

  14. The sensitivity of tropical convective precipitation to the direct radiative forcings of black carbon aerosols emitted from major regions

    Directory of Open Access Journals (Sweden)

    C. Wang

    2009-10-01

    Full Text Available Previous works have suggested that the direct radiative forcing (DRF of black carbon (BC aerosols are able to force a significant change in tropical convective precipitation ranging from the Pacific and Indian Ocean to the Atlantic Ocean. In this in-depth analysis, the sensitivity of this modeled effect of BC on tropical convective precipitation to the emissions of BC from 5 major regions of the world has been examined. In a zonal mean base, the effect of BC on tropical convective precipitation is a result of a displacement of ITCZ toward the forcing (warming hemisphere. However, a substantial difference exists in this effect associated with BC over different continents. The BC effect on convective precipitation over the tropical Pacific Ocean is found to be most sensitive to the emissions from Central and North America due to a persistent presence of BC aerosols from these two regions in the lowermost troposphere over the Eastern Pacific. The BC effect over the tropical Indian and Atlantic Ocean is most sensitive to the emissions from South as well as East Asia and Africa, respectively. Interestingly, the summation of these individual effects associated with emissions from various regions mostly exceeds their actual combined effect as shown in the model run driven by the global BC emissions, so that they must offset each other in certain locations and a nonlinearity of this type of effect is thus defined. It is known that anthropogenic aerosols contain many scattering-dominant constituents that might exert an effect opposite to that of absorbing BC. The combined aerosol forcing is thus likely differing from the BC-only one. Nevertheless, this study along with others of its kind that isolates the DRF of BC from other forcings provides an insight of the potentially important climate response to anthropogenic forcings particularly related to the unique particulate solar absorption.

  15. Auger Emitting Radiopharmaceuticals for Cancer Therapy

    Science.gov (United States)

    Falzone, Nadia; Cornelissen, Bart; Vallis, Katherine A.

    Radionuclides that emit Auger electrons have been of particular interest as therapeutic agents. This is primarily due to the short range in tissue, controlled linear paths and high linear energy transfer of these particles. Taking into consideration that ionizations are clustered within several cubic nanometers around the point of decay the possibility of incorporating an Auger emitter in close proximity to the cancer cell DNA has immense therapeutic potential thus making nuclear targeted Auger-electron emitters ideal for precise targeting of cancer cells. Furthermore, many Auger-electron emitters also emit γ-radiation, this property makes Auger emitting radionuclides a very attractive option as therapeutic and diagnostic agents in the molecular imaging and management of tumors. The first requirement for the delivery of Auger emitting nuclides is the definition of suitable tumor-selective delivery vehicles to avoid normal tissue toxicity. One of the main challenges of targeted radionuclide therapy remains in matching the physical and chemical characteristics of the radionuclide and targeting moiety with the clinical character of the tumor. Molecules and molecular targets that have been used in the past can be classified according to the carrier molecule used to deliver the Auger-electron-emitting radionuclide. These include (1) antibodies, (2) peptides, (3) small molecules, (4) oligonucleotides and peptide nucleic acids (PNAs), (5) proteins, and (6) nanoparticles. The efficacy of targeted radionuclide therapy depends greatly on the ability to increase intranuclear incorporation of the radiopharmaceutical without compromising toxicity. Several strategies to achieve this goal have been proposed in literature. The possibility of transferring tumor therapy based on the emission of Auger electrons from experimental models to patients has vast therapeutic potential, and remains a field of intense research.

  16. Remote sensing of aerosol characteristics and radiative forcing in Pakistan

    International Nuclear Information System (INIS)

    Alam, K.

    2011-01-01

    This thesis investigates the aerosol characteristics over different cities of Pakistan through satellite borne sensors, namely the Total Ozone Mapping Spectrometer (TOMS), the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Multi-angle Imaging Spectroradiometer (MISR), and ground-based instruments such as Aerosol Robotic Network (AERONET) and GRIMM 1.109 dust monitor. A Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used for trajectory analysis in order to visualize the origins of air masses and understand the spatio-temporal variability of aerosol concentrations. An assessment of seasonal variability in aerosol optical depth (AOD) for industrial, urban, semi-urban, rural, and semi-arid areas revealed maximum AOD values during summer over all the areas under investigation. The correlation between AERONET and MODIS/MISR AODs during 2007 was also analyzed for Karachi and Lahore. The correlation coefficient for Karachi was found to be relatively high between AERONET and MISR and lower between AERONET and MODIS. In contrast, the correlation coefficient for Lahore was higher between AERONET and MODIS than between AERONET and MISR. The results suggest that the MISR sensor provides better AOD estimates near the ocean while AOD estimates from the MODIS sensor are better over terrestrial regions (especially over vegetated surfaces). The assessment of aerosol optical properties and aerosol radiative forcing (ARF) through the ground-based Aerosol Robotic Network (AERONET) over Lahore and Karachi has also been investigated in this study. The monthly mean of AOD at 500 nm over Lahore and Karachi ranges from 0.39 to 0.76, and the monthly mean Angstrom Exponent ranges from 0.29 to 1.22. The relationship between the Absorption Angstrom Exponent and the Extinction Angstrom Exponent provided an indication of relative proportions of urban-industrial and mineral dust aerosols over both sites. The single scattering albedo (SSA) ranged from 0

  17. Characteristics of liver tissue for attenuate the gamma radiation

    International Nuclear Information System (INIS)

    Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R.

    2005-01-01

    It was determined the lineal attenuation coefficient of hepatic tissue before gamma radiation of a source of 137 Cs. When exposing organic material before X or gamma radiation fields, part of the energy of the photons is absorbed by the material, while another part crosses it without producing any effect. The quantity of energy that is absorbed is a measure of the dose that receives the material. The three main mechanisms by means of which the gamma rays interacting with the matter are: The Photoelectric Effect, the Compton dispersion and the Even production; the sum of these three processes is translated in the attenuation coefficient of the radiation. In this work we have used hepatic tissue of bovine, as substitute of the human hepatic tissue, and we have measured the lineal attenuation coefficient for photons of 0.662 MeV. Through a series of calculations we have determined the lineal attenuation coefficient for photons from 10 -3 to 10 -5 MeV and the measured coefficient was compared with the one calculated. (Author)

  18. Chaotic characteristic of electromagnetic radiation time series of coal or rock under different scales

    Energy Technology Data Exchange (ETDEWEB)

    Zhen-Tang Liu; En-Lai Zhao; En-Yuan Wang; Jing Wang [China University of Mining and Technology, Xuzhou (China). School of Safety Engineering

    2009-02-15

    Based on chaos theory, the chaotic characteristics of electromagnetic radiation time series of coal or rock under different loads was studied. The results show that the correlation of electromagnetic radiation time series of small-scale coal or rock and coal mine converges to a stable saturation value, which shows that these electromagnetic radiation time series have chaos characteristics. When there is danger of coal seam burst, the value of the saturation correlation dimension D{sub 2} of the electromagnetic radiation time series is bigger and it changes greatly; when there is no danger, its value is smaller and changes smoothly. The change of saturation correlation of electromagnetic radiation time series can be used to forecast coal or rock dynamic disasters. 11 refs., 4 figs.

  19. Social-Demographic Characteristics and Awareness of Radiation ...

    African Journals Online (AJOL)

    The aim of this study was to examine the socio-demographic characteristics and awareness of X-ray biohazards among technicians and sub-staff of radiology units in Benue State, North-Central Nigeria. One hundred questionnaires were distributed but only 61 respondents took part in the study comprising 55(90.2%) males ...

  20. Improved spectrometric characteristics of thallium bromide nuclear radiation detectors

    CERN Document Server

    Hitomi, K; Shoji, T; Suehiro, T; Hiratate, Y

    1999-01-01

    Thallium bromide (TlBr) is a compound semiconductor with a high atomic number and wide band gap. In this study, nuclear radiation detectors have been fabricated from the TlBr crystals. The TlBr crystals were grown by the horizontal travelling molten zone (TMZ) method using the materials purified by many pass zone refining. The crystals were characterized by measuring the resistivity, the mobility-lifetime (mu tau) product and the energy required to create an electron-hole pair (the epsilon value). Improved energy resolution has been obtained by the TlBr radiation detectors. At room temperature the full-width at half-maximum (FWHM) for the 59.5, 122 and 662 keV gamma-ray photo peak obtained from the detectors were 3.3, 8.8 and 29.5 keV, respectively. By comparing the saturated peak position of the TlBr detector with that of the CdTe detector, the epsilon value has been estimated to be about 5.85 eV for the TlBr crystal.

  1. The effect of radiation intensity on diode characteristics of silicon solar cells

    International Nuclear Information System (INIS)

    Asgerov, Sh.Q; Agayev, M.N; Hasanov, M.H; Pashayev, I.G

    2008-01-01

    In order to explore electro-physical properties of silicon solar cells, diode characteristics and ohmic properties of Al - Ni / (n+) - Si contact has been studied. Diode characteristics have been studied on a wide temperature range and on various radiation intensity, so this gives us the ability to observe the effect of the radiation and the temperature on electro-physical properties of under study solar cells. Volt-Ampere characteristics of the ohmic contacts of the silicon solar cells have been presented. As well as contact resistance and mechanism of current transmission has been identified.

  2. Thermal characteristics of tubular receivers of solar radiation line concentrators

    International Nuclear Information System (INIS)

    Klychev, Sh.I.; Zakhidov, R.A.; Khuzhanov, R. et al.

    2013-01-01

    A stationary thermal model of an LCS-HR system is considered, taking into account the basic parameters of the problem: availability of a transparent screen, selectivity of the receiver, characteristics of the heat carrier and average concentration on the surface of the tubular receiver C"". Based on this model, an algorithm and program of numerical research of the thermal characteristics of the HR-temperature of heating and local and average coefficients of efficiency are developed. For possible concentrations, the selectivity of the receiver and the transparency of the screen in linear concentrators, the potential stationary heating temperatures, and the coefficients of efficiency for main three types of heat carriers - air, water, and liquid metal coolant are studied. The time of achieving stationary values by the temperatures of the heat carrier is estimated. (author)

  3. Analysis of the current-voltage characteristics of polymer-based organic light-emitting diodes (OLEDs deposited by spin coating

    Directory of Open Access Journals (Sweden)

    Ricardo Vera

    2010-04-01

    Full Text Available Polymer-based organic light-emitting diodes (OLEDs with the structure ITO / PEDOT:PSS / MDMO-PPV / Metal were prepared by spincoating. It is known that electroluminescence of these devices is strongly dependent on the material used as cathode and on the depositionparameters of the polymer electroluminescent layer MDMO-PPV. Objective. In this work the effect of i the frequency of the spin coater(1000-8000 rpm, ii the concentration of the MDMO-PPV: Toluene solution, and iii the material used as cathode (Aluminium or Silveron the electrical response of the devices, was evaluated through current-voltage (I-V measurements. Materials and methods. PEDOT:PPSand MDMO-PPV organic layers were deposited by spin coating on ITO substrates, and the OLED structure was completed with cathodesof aluminium and silver. The electric response of the devices was evaluated based on the I-V characteristics. Results. Diodes prepared withthinner organic films allow higher currents at lower voltages; this can be achieved either by increasing the frequency of the spin coater orby using concentrations of MDMO-PPV: Toluene lower than 2% weight. A fit of the experimental data showed that the diodes have twocontributions to the current. The first one is attributed to parasitic currents between anode and cathode, and the other one is a parallel currentthrough the organic layer, in which the carrier injection mechanism is mediated by thermionic emission. Conclusions. The results of thefitting and the energy level alignment through the whole structure show that PPV-based OLEDs are unipolar devices, with current mainlyattributed to hole transport.

  4. Effect of light-emitting diode vs. fluorescent lighting on laying hens in aviary hen houses: Part 1 - Operational characteristics of lights and production traits of hens.

    Science.gov (United States)

    Long, H; Zhao, Y; Wang, T; Ning, Z; Xin, H

    2016-01-01

    Light-emitting diode (LED) lights are becoming more affordable for agricultural applications. Despite many lab-scale studies concerning impact of LED on poultry, little research has been documented under field production conditions, especially for laying hens. This 15-month field study was carried out to evaluate the effects of LED vs. fluorescent (FL) lights on laying hens (Dekalb white breed) using 4 (2 pairs) aviary hen houses each at a nominal capacity of 50,000 hens. The evaluation was done regarding operational characteristics of the lights and hen production traits. The results show that spatial distribution of the LED light was less uniform than that of the FL light. Light intensity of the LED light decreased by 27% after 3,360 h use but remained quite steady from 3,360 to 5,760 h use. Eleven out of 762 (1.44%) LED lamps (new at onset of the study) in the 2 houses failed during the 15-month experiment period. The neck area of the LED lamp was hottest, presumably the primary reason for the lamp failure as cracks were noticed in the neck region of all failed LED lamps. No differences were observed in egg weight, hen-day egg production, feed use, and mortality rate between LED and FL regimens. However, hens under the FL had higher eggs per hen housed and better feed conversion than those under the LED during 20 to 70 wk production (P Hens under the LED tended to have less feather uniformity and insulation than those under the FL (P hens under the LED showed a larger median avoidance distance than those under the FL at 36 wk age (P hens under the LED were more alert; but no difference at 60 wk age. More comparative research to quantify behavioral and production responses of different breeds of hens to LED vs. FL lighting seems warranted. © 2015 Poultry Science Association Inc.

  5. Characteristics of radiation-induced neoplastic transformation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Little, J.B.

    1986-01-01

    Data are presented to support the hypothesis that the initial step in the morphologic transformation of irradiated rodent (BALB/3T3) cells is a frequent cellular event involving a large fraction of the irradiated population. This process appears to involve DNA damage, but not to represent a targeted mutation in specific structural gene(s). Morphologic transformation and immortalization appear to be distinct steps in the overall process of transformation. In contradistinction to rodent cells, immortalization is a very rare event in human diploid cells which is induced at extremely low frequencies. The hypothesis is presented that immortality develops among clones of cells bearing stable chromosomal rearrangements which emerge during the proliferation of a population of radiation damaged cells.

  6. Self-powered radiation detector

    International Nuclear Information System (INIS)

    Playfoot, K.C.; Bauer, R.F.; Goldstein, N.P.

    1980-01-01

    This invention relates to a self powered radiation detector requiring no excitation potential to generate a signal indicating a radiation flux. Such detectors comprise two electrically insulated electrodes, at a distance from each other. These electrodes are made of conducting materials having a different response for neutron and/or gamma ray radiation flux levels, as in nuclear power stations. This elongated detector generates an electric signal in terms of an incident flux of radiations cooperating with coaxial conductors insulated from each other and with different radiation reaction characteristics. The conductor with the greatest reaction to the radiations forms the central emitting electrode and the conductor with the least reaction to the radiations forms a tubular coaxial collecting electrode. The rhodium or cobalt tubular emitting electrode contains a ductile central conducting cable placed along the longitudinal axis of the detector. The latter is in high nickel steel with a low reaction to radiation [fr

  7. Neutron radiation characteristics of the IVth generation reactor spent fuel

    Science.gov (United States)

    Bedenko, Sergey; Shamanin, Igor; Grachev, Victor; Knyshev, Vladimir; Ukrainets, Olesya; Zorkin, Andrey

    2018-03-01

    Exploitation of nuclear power plants as well as construction of new generation reactors lead to great accumulation of spent fuel in interim storage facilities at nuclear power plants, and in spent fuel «wet» and «dry» long-term storages. Consequently, handling the fuel needs more attention. The paper is focused on the creation of an efficient computational model used for developing the procedures and regulations of spent nuclear fuel handling in nuclear fuel cycle of the new generation reactor. A Thorium High-temperature Gas-Cooled Reactor Unit (HGTRU, Russia) was used as an object for numerical research. Fuel isotopic composition of HGTRU was calculated using the verified code of the MCU-5 program. The analysis of alpha emitters and neutron radiation sources was made. The neutron yield resulting from (α,n)-reactions and at spontaneous fission was calculated. In this work it has been shown that contribution of (α,n)-neutrons is insignificant in case of such (Th,Pu)-fuel composition and HGTRU operation mode, and integral neutron yield can be approximated by the Watt spectral function. Spectral and standardized neutron distributions were achieved by approximation of the list of high-precision nuclear data. The distribution functions were prepared in group and continuous form for further use in calculations according to MNCP, MCU, and SCALE.

  8. Radiation response characteristics of human cell in vitro

    International Nuclear Information System (INIS)

    Hall, E.J.

    1987-01-01

    Improvements in tissue culture techniques and growth media have made it possible to culture a range of cells of human origin, both normal and malignant. The most recent addition to the list are endothelial cells. Interesting results have been obtained, some of which may have implications in Radiation Therapy. (i) Repair of Potentially Lethal Damage (PLDR) has been observed in all cell lines investigated; cells of normal origin repair PLD at least as well as malignant cells, which makes clinical trials of PLDR inhibitors of doubtful usefulness. (ii) PLD in fibroblasts of human origin appears to have a component that is repaired rapidly, in a matter of minutes, as well as a slower component that takes hours to repair. (iii) Sublethal damage repair, manifest by a dose-rate effect, has also been observed in all human cell lines tested. Cells of normal tissue origin, including fibroblasts and endothelial cells, exhibit a dose-rate effect that is intermediate between that for cells from traditionally resistant tumors (melanoma and osteosarcoma) and cells from more sensitive tumors (neuroblastoma and breast). (iv) Fibroblasts from patients with Ataxia Telangectasia (AT) are much more sensitive to x-rays, with a D/sub o/ about half that for normal human fibroblasts. Nevertheless repair of both PLD and SLD can be demonstrated in these cells

  9. Microphysical and Radiative Characteristics of Convective Clouds during COHMEX.

    Science.gov (United States)

    Fulton, Richard; Heymsfield, Gerald M.

    1991-01-01

    The use of passive remote microwave radiance measurements above cloud tops for rainrate estimation is complicated by the complex nature of cloud microphysics. The knowledge of the microphysical structure of clouds, specifically the hydrometeor types, shapes, sizes, and their vertical distribution, is important because radiative emission and scattering effects are dependent upon the hydrometeor distribution. This paper has two purposes: first, to document the structure and evolution of two strong thunderstorms in Alabama using radar multiparameter data; and second, to relate the inferred microphysics to the resulting upwelling microwave radiance observed concurrently by high altitude aircraft. These measurements were collected during the COHMEX field program in the summer of 1986. The radar analysis includes a description of the parameters reflectivity Z, differential reflectivity ZDR, linear depolarization ratio LDR, and hail signal HS for two thunderstorm cases on 11 July 1986. The simultaneous aircraft data includes passive microwave brightness temperature (TB) measurements at four frequencies ranging from 18 to 183 GHz as well as visible and infrared data.The remote radar observations reveal the existence of large ice particles within the storms which is likely to have caused the observed low microwave brightness temperatures. By relating the evolution of the radar measureables to the microwave TB's it has been found that knowledge of the storm microphysics and its evolution is important to adequately understand the microwave TB's.

  10. Microwave discharge electrodeless lamps (MDEL). III. A novel tungsten-triggered MDEL device emitting VUV and UVC radiation for use in wastewater treatment.

    Science.gov (United States)

    Horikoshi, Satoshi; Miura, Takashi; Kajitani, Masatsugu; Serpone, Nick

    2008-03-01

    Exposure to low doses of the xenoestrogen bisphenol A (BPA) and to the hormonal 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide, an environmental endocrine disruptor, can have serious health consequences such as the induction of mammary gland ductal hyperplasias and carcinoma (LaChapelle et al., Reprod. Toxicol., 2007, 23, 20; Murray et al., Reprod. Toxicol., 2007, 23, 383). To the extent that these toxins are present in wastewaters (Donald et al., Sci. Total Environ. 1999, 231, 173; Brotons et al., Environ. Health Perspect. 1994, 103, 608; Olea et al., Environ. Health Perspect. 1996, 104, 298; Biles et al., J. Agric. Food Chem. 1997, 45, 3541; Markey et al., J. Steroid Biochem. Mol. Biol., 2003, 83, 235), we examined their oxidative destruction in aqueous media by a novel light source. A tungsten-triggered microwave discharge electrodeless lamp (W-MDEL) was fabricated for possible use in wastewater treatment using vacuum UV-transparent quartz in which a tungsten trigger, also embedded in quartz, was attached to the MDEL to aid in the self-ignition of the lamp on irradiation at low microwave power levels. The quantity of mercury gas in the W-MDEL was optimized by monitoring the continuous radiation and peak intensities of the emitted light in the vacuum UV (VUV) and UVC regions. The usefulness of the W-MDEL device was assessed through the degradation of 2,4-D and BPA in air-equilibrated aqueous media and in oxygen-saturated aqueous media. Enhanced degradation of these two xenoestrogenic toxins was achieved by increasing the number of W-MDEL devices while keeping constant the microwave radiation feeding each W-MDEL lamp. This novel lamp provides an additional light source in the photooxidation of environmental contaminants without the need for a metal-oxide photocatalyst. Under our conditions, process dynamics using the W-MDEL light source are greater than with the more conventional photochemical methods that employ low-pressure Hg arc electrode lamps in synthetic

  11. Monte Carlo simulation of age-dependent radiation dose from alpha- and beta-emitting radionuclides to critical trabecular bone and bone marrow targets

    Science.gov (United States)

    Dant, James T.; Richardson, Richard B.; Nie, Linda H.

    2013-05-01

    Alpha (α) particles and low-energy beta (β) particles present minimal risk for external exposure. While these particles can induce leukemia and bone cancer due to internal exposure, they can also be beneficial for targeted radiation therapies. In this paper, a trabecular bone model is presented to investigate the radiation dose from bone- and marrow-seeking α and β emitters to different critical compartments (targets) of trabecular bone for different age groups. Two main issues are addressed with Monte Carlo simulations. The first is the absorption fractions (AFs) from bone and marrow to critical targets within the bone for different age groups. The other issue is the application of 223Ra for the radiotherapy treatment of bone metastases. Both a static model and a simulated bone remodeling process are established for trabecular bone. The results show significantly lower AFs from radionuclide sources in the bone volume to the peripheral marrow and the haematopoietic marrow for adults than for newborns and children. The AFs from sources on the bone surface and in the bone marrow to peripheral marrow and haematopoietic marrow also varies for adults and children depending on the energy of the particles. Regarding the use of 223Ra as a radionuclide for the radiotherapy of bone metastases, the simulations show a significantly higher dose from 223Ra and its progeny in forming bone to the target compartment of bone metastases than that from two other more commonly used β-emitting radiopharmaceuticals, 153Sm and 89Sr. There is also a slightly lower dose from 223Ra in forming bone to haematopoietic marrow than that from 153Sm and 89Sr. These results indicate a higher therapy efficiency and lower marrow toxicity from 223Ra and its progeny. In conclusion, age-related changes in bone dimension and cellularity seem to significantly affect the internal dose from α and β emitters in the bone and marrow to critical targets, and 223Ra may be a more efficient

  12. On microscopic theory of radiative nuclear reaction characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Kamerdzhiev, S. P. [National Research Centre “Kurchatov Institute” (Russian Federation); Achakovskiy, O. I., E-mail: oachakovskiy@ippe.ru; Avdeenkov, A. V. [Institute for Physics and Power Engineering (Russian Federation); Goriely, S. [Institut d’Astronomie et d’Astrophysique (Belgium)

    2016-07-15

    A survey of some results in the modern microscopic theory of properties of nuclear reactions with gamma rays is given. First of all, we discuss the impact of Phonon Coupling (PC) on the Photon Strength Function (PSF) because it represents the most natural physical source of additional strength found for Sn isotopes in recent experiments that could not be explained within the standard HFB + QRPA approach. The self-consistent version of the Extended Theory of Finite Fermi Systems in the Quasiparticle Time Blocking Approximation is applied. It uses the HFB mean field and includes both the QRPA and PC effects on the basis of the SLy4 Skyrme force. With our microscopic E1 PSFs, the following properties have been calculated for many stable and unstable even–even semi-magic Sn and Ni isotopes as well as for double-magic {sup 132}Sn and {sup 208}Pb using the reaction codes EMPIRE and TALYS with several Nuclear Level Density (NLD) models: (1) the neutron capture cross sections; (2) the corresponding neutron capture gamma spectra; (3) the average radiative widths of neutron resonances. In all the properties considered, the PC contribution turned out to be significant, as compared with the standard QRPA one, and necessary to explain the available experimental data. The results with the phenomenological so-called generalized superfluid NLD model turned out to be worse, on the whole, than those obtained with the microscopic HFB + combinatorial NLD model. The very topical question about the M1 resonance contribution to PSFs is also discussed.Finally, we also discuss the modern microscopic NLD models based on the self-consistent HFB method and show their relevance to explain the experimental data as compared with the phenomenological models. The use of these self-consistent microscopic approaches is of particular relevance for nuclear astrophysics, but also for the study of double-magic nuclei.

  13. Spectral investigation of hot-spot and cavity resonance effects on the terahertz radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ single crystal mesa structures

    Science.gov (United States)

    Kadowaki, Kazuo; Watanabe, Chiharu; Minami, Hidetoshi; Yamamoto, Takashi; Kashiwagi, Takanari; Klemm, Richard

    2014-03-01

    Terahertz (THz) electromagnetic radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ mesa structures in the case of single mesa and series-connected mesas is investigated by the FTIR spectroscopic technique while observing its temperature distribution simultaneously by a SiC photoluminescence technique. Changing the bias level, sudden jumps of the hot-spot position were clearly observed. Although the radiation intensity changes drastically associated with the jump of the hot spot position, the frequency is unaffected as long as the voltage per junction is kept constant. Since the frequency of the intense radiation satisfies the cavity resonance condition, we confirmed that the cavity resonance is of primarily importance for the synchronization of whole intrinsic Josephson junctions in the mesa for high power radiation. This work was supported in part by the Grant-in-Aid for challenging Exploratory Research, the Ministry of Education, Culture, Sports, Science & Technology (MEXT).

  14. Theoretical analysis on radiation and reception characteristics of an oblate spheroidal antenna for electron plasma waves

    International Nuclear Information System (INIS)

    Ohnuki, S.; Adachi, S.; Ohnuma, T.

    1978-01-01

    The radiation and reception characteristics of the oblate spheroidal antenna for electron plasma waves are theoretically investigated. The analysis is carried out as a boundary-value problem. The formulas for the radiation and reception characteristics such as radiation impedance, electron charge distributions, radiated wave potential, directional properties, and receiving voltage of the oblate spheroidal antenna are analytically obtained. As a result, it is concluded that the radiation and reception characteristics of the antennas are not uniquely determined by k/sub p/a (k/sub p/ is the wave number of an electron plasma wave, and a is the radius of the circular-plate antenna), but are determined by two out of three factors, k/sub p/a, zeta (radius divided by Debye length), and ω/ω/sub p/ (angular signal frequency to angular plasma frequency). This conclusion is in marked contrast to the conventional theory in which the charge distribution on the antenna is assumed a priori as uniform and, thus, the antenna characteristics are uniquely determined by k/sub p/a. It is claimed that the experimental results obtained hitherto support the present new theory

  15. Characteristics of withstanding radiation damage of InP crystals and devices

    International Nuclear Information System (INIS)

    Yamaguchi, Masafumi; Ando, Koshi

    1988-01-01

    Recently, the authors discovered that the characteristics of with standing radiation damage of InP crystals and devices (solar cells) are superior to those of Si and GaAs crystals and devices. Also the restoration phenomena at room temperature of radiation deterioration and the accelerated anneal phenomena by light irradiation and the injection of other minority, carriers in InP system devices were found. Such excellent characteristics suggested that InP devices are promising for the use in space. In this paper, taking an example of solar cells, the radiation resistance characteristics and their mechanism of InP crystals and devices are reported, based on the results of analysis by deep level transient spectroscopy and others. In InP solar cells, the high efficiency of photoelectric conversion was maintained even in the high dose irradiation of 1 MeV electron beam. As the carrier concentration in InP crystals is higher, they are stronger against radiation. With the increase of carrier concentration, the rate of anneal of radiation deterioration at room temperature increased. The accelerated anneal effect by minority carrier injection was remarkable in n + -p junction cells. The excellent characteristics of InP crystals are due to the formation of Frenkel defects of P and their instability. (K.I.)

  16. Attenuation characteristics of materials used in radiation protection as radiation shielding

    International Nuclear Information System (INIS)

    Almeida Junior, Airton T.; Araujo, F.G.S.; Nogueira, M.S.; Santos, M.A.P.

    2013-01-01

    Crystal glass has been widely used as shielding material in gamma radiation sources as well as x-ray generating equipment to replace the plumbiferous glass, in order to minimize exposure to individuals. In this work, ten plates of crystal glass, with dimensions of 20cm x 20cm and range of thicknesses from 0.5 to 2.0 cm, and barite concrete were irradiated with potential constants of 60kV, 80kV, 110kV, 150kV and gamma radiation of 60 Co. The curves of attenuation and of transmission were obtained for crystal glass, barite plaster and barite concrete (mGy/mA.min) at 1 meter as a function of thickness.Crystal glass has been widely used as shielding material in gamma radiation sources as well as x-ray generating equipment to replace the plumbiferous glass, in order to minimize exposure to individuals. In this work, ten plates of crystal glass, with dimensions of 20cm x 20cm and range of thicknesses from 0.5 to 2.0 cm, and barite concrete were irradiated with potential constants of 60kV, 80kV, 110kV, 150kV and gamma radiation of 60 Co. The curves of attenuation and of transmission were obtained for crystal glass, barite plaster and barite concrete (mGy/mA.min) at 1 meter as a function of thickness. (author)

  17. Hybrid Light-Emitting Diode Enhanced With Emissive Nanocrystals

    DEFF Research Database (Denmark)

    Kopylov, Oleksii

    This thesis investigates a new type of white light emitting hybrid diode, composed of a light emitting GaN/InGaN LED and a layer of semiconductor nanocrystals for color conversion. Unlike standard white LEDs, the device is configured to achieve high color conversion efficiency via non-radiative e......This thesis investigates a new type of white light emitting hybrid diode, composed of a light emitting GaN/InGaN LED and a layer of semiconductor nanocrystals for color conversion. Unlike standard white LEDs, the device is configured to achieve high color conversion efficiency via non...... of the hybrid diode fabrication including process techniques for GaN LED and incorporation of the nanocrystals are presented with the emphasis on the differences with standard LED processing. Results and analysis of optical and electrical characterization including photoluminescence (PL), micro-PL, time......-resolved PL and electroluminescence (EL) together with current-voltage characteristics are presented to evaluate the device performance. A clear evidence of non-radiative energy transfer was seen in the carrier dynamics of both the LED and the nanocrystals when the quantum well – nanocrystals separation...

  18. Research on infrared radiation characteristics of Pyromark1200 high-temperature coating

    Science.gov (United States)

    Song, Xuyao; Huan, Kewei; Dong, Wei; Wang, Jinghui; Zang, Yanzhe; Shi, Xiaoguang

    2014-11-01

    Pyromark 1200 (Tempil Co, USA), which is a type of high-temperature high-emissivity coating, is silicon-based with good thermal radiation performance. Its stably working condition is at the temperature range 589~922 K thus a wide range of applications in industrial, scientific research, aviation, aerospace and other fields. Infrared emissivity is one of the most important factors in infrared radiation characteristics. Data on infrared spectral emissivity of Pyromark 1200 is in shortage, as well as the reports on its infrared radiation characteristics affected by its spray painting process, microstructure and thermal process. The results of this research show that: (1) The coating film critical thickness on the metal base is 10μm according to comparison among different types of spray painting process, coating film thickness, microstructure, which would influence the infrared radiation characteristics of Pyromark 1200 coating. The infrared spectral emissivity will attenuate when the coating film thickness is lower or much higher than that. (2) Through measurements, the normal infrared radiation characteristics is analyzed within the range at the temperature range 573~873 K under normal atmospheric conditions, and the total infrared spectral emissivity of Pyromark 1200 coating is higher than 0.93 in the 3~14 μm wavelength range. (3) The result of 72-hour aging test at the temperature 673 K which studied the effect of thermal processes on the infrared radiation characteristics of the coating shows that the infrared spectral emissivity variation range is approximately 0.01 indicating that Pyromark 1200 coating is with good stability. Compared with Nextel Velvet Coating (N-V-C) which is widely used in optics field, Pyromark 1200 high-temperature coating has a higher applicable temperature and is more suitable for spraying on the material surface which is in long-term operation under high temperature work conditions and requires high infrared spectral emissivity.

  19. Experimental and numerical investigations of radiation characteristics of Russian portable/compact pulsed neutron generators: ING-031, ING-07, ING-06 and ING-10-20-120

    International Nuclear Information System (INIS)

    Chernikova, D.; Romodanov, V.L.; Belevitin, A.G.; Afanas'ev, V.V.; Sakharov, V.K.; Bogolubov, E.P.; Ryzhkov, V.I.; Khasaev, T.O.; Sladkov, A.A.; Bitulev, A.A.

    2014-01-01

    The present paper discusses results of full-scale experimental and numerical investigations of influence of construction materials of portable pulsed neutron generators ING-031, ING-07, ING-06 and ING-10-20-120 (VNIIA, Russia) to their radiation characteristics formed during and after an operation (shutdown period). In particular, it is shown that an original monoenergetic isotropic angular distribution of neutrons emitted by TiT target changes into the significantly anisotropic angular distribution with a broad energy spectrum stretching to the thermal region. Along with the low-energetic neutron part, a significant amount of photons appears during the operation of generators. In the pulse mode of operation of neutron generator, a presence of the construction materials leads to the “tailing” of the original neutron pulse and the appearance of an accompanying photon pulse at ∼3ns after the instant neutron pulse. In addition to that, reactions of neutron capture and inelastic scattering lead to the creation of radioactive nuclides, such as 58 Co, 62 Cu, 64 Cu and 18 F, which form the so-called activation radiation. Thus, the selection of a portable neutron generator for a particular type of application has to be done considering radiation characteristics of the generator itself. This paper will be of interest to users of neutron generators, providing them with valuable information about limitations of a specific generator and with recommendations for improving the design and performance of the generator as a whole

  20. Change of nucleolus characteristic of fish embryo cells under the influence of low-level radiation

    International Nuclear Information System (INIS)

    Arkhipchuk, V.V.

    1995-01-01

    The nucleolus activity of fish embryo cells was stimulated by low-level radiation at a dose rate of 2-13 mGy/h. The size of nucleoli generally increased in embryos of Cyprinus carpio, whereas the number of nucleoli was greater in embryos of Carassius auratus gibelio. The higher the functional activity of nucleolus is, the more pronounced are changes in the characteristics. The size of single nucleolus at gastrulation is the most sensitive characteristic. 16 refs.; 1 tab

  1. Thermal radiation characteristics of nonisothermal cylindrical enclosures using a numerical ray tracing technique

    Science.gov (United States)

    Baumeister, Joseph F.

    1990-01-01

    Analysis of energy emitted from simple or complex cavity designs can lead to intricate solutions due to nonuniform radiosity and irradiation within a cavity. A numerical ray tracing technique was applied to simulate radiation propagating within and from various cavity designs. To obtain the energy balance relationships between isothermal and nonisothermal cavity surfaces and space, the computer code NEVADA was utilized for its statistical technique applied to numerical ray tracing. The analysis method was validated by comparing results with known theoretical and limiting solutions, and the electrical resistance network method. In general, for nonisothermal cavities the performance (apparent emissivity) is a function of cylinder length-to-diameter ratio, surface emissivity, and cylinder surface temperatures. The extent of nonisothermal conditions in a cylindrical cavity significantly affects the overall cavity performance. Results are presented over a wide range of parametric variables for use as a possible design reference.

  2. The exemption from the requirement of registration and/or licensing of some sources. machines and devices emitting ionizing and /or on ionizing radiation: a proposed draft for Israeli regulations

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, T; Margaliot, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

    1997-11-16

    The licensing and authorization of the import, purchase, distribution, transportation and application of radioactive materials and devices emitting ionizing and/or non-ionizing radiation are carried out in Israel by the Ministries of the Environment and of Health. The legal basis for file authority of these Ministries in radiation protection matters is file {sup P}harmacists Regulation- Radioactive Elements and Products Thereof, 1981 (revision 1994) (PRREPT). Licenses are issued by the Chief Radiation Executive (CUE) appointed by the Minister of the Environment and the Minister of Health. The Regulations include a clause which enables the CUE to exempt certain amounts of radioactive materials from file requirements laid down in the PRREPT. The exemption clause is general and does not indicate the types and amounts of radioactive material may be exempted. The proposed draft Israeli regulations are related to exemption of some sources, machines and devices emitting ionizing and non-ionizing radiation, wife a suggestion to extend file above mentioned exemption clause to include some machines and devices and to provide an explicit and detailed list of materials, sources and devices to be exempted. Among these are the following: (authors)

  3. The exemption from the requirement of registration and/or licensing of some sources. machines and devices emitting ionizing and /or on ionizing radiation: a proposed draft for Israeli regulations

    International Nuclear Information System (INIS)

    Schlesinger, T.; Margaliot, M.

    1997-01-01

    The licensing and authorization of the import, purchase, distribution, transportation and application of radioactive materials and devices emitting ionizing and/or non-ionizing radiation are carried out in Israel by the Ministries of the Environment and of Health. The legal basis for file authority of these Ministries in radiation protection matters is file P harmacists Regulation- Radioactive Elements and Products Thereof, 1981 (revision 1994) (PRREPT). Licenses are issued by the Chief Radiation Executive (CUE) appointed by the Minister of the Environment and the Minister of Health. The Regulations include a clause which enables the CUE to exempt certain amounts of radioactive materials from file requirements laid down in the PRREPT. The exemption clause is general and does not indicate the types and amounts of radioactive material may be exempted. The proposed draft Israeli regulations are related to exemption of some sources, machines and devices emitting ionizing and non-ionizing radiation, wife a suggestion to extend file above mentioned exemption clause to include some machines and devices and to provide an explicit and detailed list of materials, sources and devices to be exempted. Among these are the following: (authors)

  4. The improvement for fire retardant and radiation resistance characteristics of chloroprene rubber

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. Y.; Lee, C.; Kim, P. J.; Kim, J. H

    2004-04-01

    In the report, in order to improve the fire retardancy better Chloroprene Rubber (CR) after adding each fixed amount of inorganic metallic hydroxide, and then compared and assessed fire retardancy with electrical properties and mechanical properties we intended to choose the most excellent additives. Also according to Co{sup 60} {gamma}-ray irradiation, we compared electrical, echanical and fire retardant characteristics to analyse to have the additives of inorganic filler effect on CR's antirad characteristic. In result, CR containing inorganic additive, advanced considerably fire retardant characteristics, but seems to be tended to declined electrical and mechanical characteristics on the whole. In syntherically comparison, the specimen viewed the most excellent characteristics is CR containing Magnesium hydroxide. As to Co{sup 60} {gamma}-ray irradiated Chloroprene rubber containing inorganic additives, fire retardant characteristic are improved, but electrical and mechanical properties are deteriorated as a function of radiation dose. Comparing before irradiation and after irradiation, the best inorganic filler into CR consider Magnesium hydroxide. In this report, in case of adding 30 phr of inorganic filler to CR we observed fire retardancy and radiation resistance characteristics change in according to the kinds of additives, but the research for choosing the optimum amount of additives is considered to progress from now on as adjusting the amount of additives presented excellent characteristics.

  5. Characteristics of rotating target neutron source and its use in radiation effects studies

    International Nuclear Information System (INIS)

    Van Konynenburg, R.A.; Barschall, H.H.; Booth, R.; Wong, C.

    1975-07-01

    The Rotating Target Neutron Source (RTNS) at Lawrence Livermore Laboratory is currently the most intense source of DT fusion neutrons available for the study of radiation effects in materials. This paper will present a brief description of the machine, outline the history of its development and discuss its performance characteristics and its application to CTR materials research. (U.S.)

  6. Spectral and directional radiation characteristics of thin-film coated isothermal semitransparent plates

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R P; Viskanta, R

    1975-01-01

    An analysis is presented for predicting the effective spectral directional radiation characteristics of an isothermal, semitransparent sheet surrounded on both sides by massive dielectrics. The sheet can be coated with an optically thin film and used as selective cover plates for solar collectors. Directional and polarization effects and the spectral transmittance and reflectance are considered. Sample results for candidate materials are presented.

  7. Effect of surface characteristics on diffuse reflection radiation at lambda=0. 40. mu. m

    Energy Technology Data Exchange (ETDEWEB)

    Takashima, T [Atmospheric Environment Service, Downsview, Ontario (Canada)

    1976-08-01

    The diffuse radiation in the upward direction at the top and at an internal level of an inhomogeneous atmosphere is computed at lambda=0.40 ..mu..m. The surface is assumed to reflect light in accordance with a hybrid mode of a diffuse and specular reflector. The objective is to estimate the effect of underlying surface characteristics in terms of the diffuse radiation field. By making use of these results, accuracy in monitoring the atmospheric aerosols would be increased for the use of remote sensing satellite techniques. Junge power law (..gamma..*=3) is adopted for the size distribution of aerosols (1963), while the data given by McClatchy et al. (1971) is used for the number density of aerosols with height distribution. It is noted from the computations that the diffuse reflection radiation is affected by the surface characteristics, even if the albedo of the surface is a fixed constant and very small.

  8. Study on electromagnetic radiation and mechanical characteristics of coal during an SHPB test

    Science.gov (United States)

    Chengwu, Li; Qifei, Wang; Pingyang, Lyu

    2016-06-01

    Dynamic loads provided by a Split Hopkinson pressure bar are applied in the impact failure experiment on coal with an impact velocity of 4.174-17.652 m s-1. The mechanical property characteristics of coal and an electromagnetic radiation signal can be detected and measured during the experiment. The variation of coal stress, strain, incident energy, dissipated energy and other mechanical parameters are analyzed by the unidimensional stress wave theory. It suggests that with an increase of the impact velocity, the mechanical parameters and electromagnetic radiation increased significantly and the dissipated energy of the coal sample has a high discrete growing trend during the failure process of coal impact. Combined with the received energy of the electromagnetic radiation signal, the relationship between these mechanical parameters and electromagnetic radiation during the failure process of coal burst could be analyzed by the grey correlation model. The results show that the descending order of the gray correlation degree between the mechanical characteristics and electromagnetic radiation energy are impact velocity, maximum stress, the average stress, incident energy, the average strain, maximum strain, the average strain rate and dissipation energy. Due to the correlation degree, the impact velocity and incident energy are relatively large, and the main factor affecting the electromagnetic radiation energy of coal is the energy magnitude. While the relationship between extreme stress and the radiation energy change trend is closed, the stress state of coal has a greater impact on electromagnetic radiation than the strain and destruction which can deepen the research of the coal-rock dynamic disaster electromagnetic monitoring technique.

  9. Characteristics and correlation of various radiation measuring methods in spatial radiation measurement

    International Nuclear Information System (INIS)

    Yoneda, Kazuhiro; Tonouchi, Shigemasa

    1992-01-01

    When the survey of the state of natural radiation distribution was carried out, for the purpose of examining the useful measuring method, the comparison of the γ-ray dose rate calculated from survey meter method, in-situ measuring method and the measuring method by sampling soil was carried out. Between the in-situ measuring method and the survey meter method, the correlation Y=0.986X+5.73, r=0.903, n=18, P<0.01 was obtained, and the high correlation having the inclination of nearly 1 was shown. Between the survey meter method and the measuring method by sampling soil, the correlation Y=1.297X-10.30, r=0.966, n=20 P<0.01 was obtained, and the high correlation was shown, but as for the dose rate contribution, the disparities of 36% in U series, 6% in Th series and 20% in K-40 were observed. For the survey of the state of natural radiation distribution, the method of using in combination the survey meter method and the in-situ measuring method or the measuring method by sampling soil is suitable. (author)

  10. Synthesis, Thermal and Luminescence Characteristics of Eu-activated SrZn2Si2O7 as a Nanocrystalline Blue-emitting Phosphor for LEDs Application

    International Nuclear Information System (INIS)

    Sameie, H.; Salimi, R.; Alvani, A.A.S.; Sarabi, A.A.; Farsi, M.A.M.; Roohnikan, M.; Mohammadloo, H.E.; Tahriri, M.

    2011-01-01

    In this research, blue-emitting nanocrystalline phosphor SrZn 2 Si 2 O 7 : Eu 2+ was successfully synthesized with two routes: solid state reaction (SS) and sol-gel method (SG). The effects of preparation processes on the crystallization, morphology and optical properties were investigated by appropriate techniques. From the photoluminescence results, obtained phosphors emit strong blue light due to 4f 6 5d 1 ( 2 D)→4f 7 ( 8 S 7/2 ) transition of Eu 2+ ions which act as luminescence centers. The experimental results reveal that the excitation and emission intensities for SS are better than SG due to higher calcination temperature, whereas the samples synthesized by wet chemical method have relatively regular morphology. (author)

  11. Crystal structure and Temperature-Dependent Luminescence Characteristics of KMg4(PO4)3:Eu2+ phosphor for White Light-emitting diodes

    Science.gov (United States)

    Chen, Jian; Liu, Yangai; Mei, Lefu; Liu, Haikun; Fang, Minghao; Huang, Zhaohui

    2015-01-01

    The KMg4(PO4)3:Eu2+ phosphor was prepared by the conventional high temperature solid-state reaction. The crystal structure, luminescence and reflectance spectra, thermal stability, quantum efficiency and the application for N-UV LED were studied respectively. The phase formation and crystal structure of KMg4(PO4)3:Eu2+ were confirmed from the powder X-ray diffraction and the Rietveld refinement. The concentration quenching of Eu2+ in the KMg4(PO4)3 host was determined to be 1mol% and the quenching mechanism was certified to be the dipole–dipole interaction. The energy transfer critical distance of as-prepared phosphor was calculated to be about 35.84Å. Furthermore, the phosphor exhibited good thermal stability and the corresponding activation energy ΔE was reckoned to be 0.24eV. Upon excitation at 365nm, the internal quantum efficiency of the optimized KMg4(PO4)3:Eu2+ was estimated to be 50.44%. The white N-UV LEDs was fabricated via KMg4(PO4)3:Eu2+, green-emitting (Ba,Sr)2SiO4:Eu2+, and red-emitting CaAlSiN3:Eu2+ phosphors with a near-UV chip. The excellent color rendering index (Ra = 96) at a correlated color temperature (5227.08K) with CIE coordinates of x = 0.34, y = 0.35 of the WLED device indicates that KMg4(PO4)3:Eu2+ is a promising blue-emitting phosphor for white N-UV light emitting diodes (LEDs). PMID:25855866

  12. Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation

    International Nuclear Information System (INIS)

    Nicolay, Nils H.; Sommer, Eva; Lopez, Ramon; Wirkner, Ute; Trinh, Thuy; Sisombath, Sonevisay; Debus, Jürgen; Ho, Anthony D.; Saffrich, Rainer; Huber, Peter E.

    2013-01-01

    Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression

  13. Investigation of characteristics and radiation hardness of the Beetle 1.0 front-end chip

    CERN Document Server

    Van Bakel, N; Jans, E; Klous, S; Verkooijen, H

    2001-01-01

    Noise characteristics of the Beetle 1.0 front-end chip have been investigated as a function of input capacitance. Values for the equivalent noise charge and ballastic deficit have been extracted. Amplification and pulse shape have been studied by varying the bias settings over a wide range. Results are compared with simulations that include realistic impedances at the input and output. The chip has been subjected to 10 Mrad of radiation. Subsequently, its behaviour is measured again and compared to that preceeding the irradiation. Observed radiation damage effects are discussed.

  14. Characteristics of radiated power for various TFTR [Tokamak Fusion Test Reactor] regimes

    International Nuclear Information System (INIS)

    Bush, C.E.; Schivell, J.; McNeill, D.H.

    1988-04-01

    Power loss studies were carried out to determine the impurity radiation and energy transport characteristics of various TFTR operation and confinement regimes including L-Mode, detached plasma, co-only neutral beam injection (energetic ion regime), and the enhanced confinement (''supershot'') regime. Combined bolometric, spectroscopic, and infrared photometry measurements provide a picture of impurity behavior and power accounting in TFTR. The purpose of this paper is to make a survey of the various regimes with the aim of determining the radiated power signatures of each. 10 refs., 6 figs., 1 tab

  15. Characteristics Of Dosimeter TL CaSO4:Dy Glass Capillaries For Environmental Radiation Dose Monitoring

    International Nuclear Information System (INIS)

    Sofyan Hasnel; Yulianti, Helfi; Ramain, Abubakar; Kusumawati, Dyah D.; Suyati

    2000-01-01

    research on the characteristic of dosimeter TL CaSO 4 : Dy glass capillaries for environmental dose radiation have been carried out. The results obtained are uniform response and reproducibility during three cycles consumption with average percentage standard deviation of 7.31 % and 5.45%. The response dose is linear and has a minimum detectable dose of 0.01 mGy, sunshine effect with non-penetrating light capsule of 4.65%, humidity effects is not significant by using non-penetrating light capsule. Radiation dose information during 30 days are fading 25%

  16. Report by the work-group on 'safety of medical devices emitting ionizing radiations'. Articulation of radiation protection requirements of the 97/43/Euratom directive and IAEA recommendations with the essential requirements of the 93/42/CEE directive related to medical devices used in external radiotherapy

    International Nuclear Information System (INIS)

    2010-01-01

    As some dysfunctions and events had been reported in 2007 and 2008 in field of radiotherapy, this report aims at clarifying the articulation between the different European regulations concerning medical devices emitting ionizing radiations and radiation protection. The authors report a survey with device manufacturers, and analyze the content of the different regulations and recommendations. Then, the authors recommend and propose a set of actions related to the IAEA requirements and recommendations, to CE marking requirements, and to new radiation protection and safety requirements present in the Euratom directive

  17. SPEAKING IN LIGHT - Jupiter radio signals as deflections of light-emitting electron beams in a vacuum chamber

    Science.gov (United States)

    Petrovic, K.

    2015-10-01

    Light emitting electron beam generated in a vacuum chamber is used as a medium for visualizing Jupiter's electromagnetic radiation. Dual dipole array antenna is receiving HF radio signals that are next amplified to radiate a strong electromagnetic field capable of influencing the propagation of electron beam in plasma. Installation aims to provide a platform for observing the characteristics of light emitting beam in 3D, as opposed to the experiments with cathode ray tubes in 2-dimensional television screens. Gas giant 'speaking' to us by radio waves bends the light in the tube, allowing us to see and hear the messages of Jupiter - God of light and sky.

  18. Suppression of roll-off characteristics of organic light-emitting diodes by narrowing current injection/transport area to 50 nm

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Kyohei, E-mail: k-hayashi@bioorg.rcast.u-tokyo.ac.jp; Inoue, Munetomo; Yoshida, Kou [Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Nakanotani, Hajime [Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); JST, ERATO, Adachi Molecular Exciton Engineering Project, c/o OPERA, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Innovative Organic Device Laboratory, Institute of Systems, Information Technologies and Nanotechnologies (ISIT), 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Mikhnenko, Oleksandr; Nguyen, Thuc-Quyen, E-mail: quyen@chem.ucsb.edu, E-mail: adachi@cstf.kyushu-u.ac.jp [Center for Polymers and Organic Solids, University of California, Santa Barbara, California 93106-9510 (United States); Adachi, Chihaya, E-mail: quyen@chem.ucsb.edu, E-mail: adachi@cstf.kyushu-u.ac.jp [Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); JST, ERATO, Adachi Molecular Exciton Engineering Project, c/o OPERA, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Innovative Organic Device Laboratory, Institute of Systems, Information Technologies and Nanotechnologies (ISIT), 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan)

    2015-03-02

    Using e-beam nanolithography, the current injection/transport area in organic light-emitting diodes (OLEDs) was confined into a narrow linear structure with a minimum width of 50 nm. This caused suppression of Joule heating and partial separation of polarons and excitons, so the charge density where the electroluminescent efficiency decays to the half of the initial value (J{sub 0}) was significantly improved. A device with a narrow current injection width of 50 nm exhibited a J{sub 0} that was almost two orders of magnitude higher compared with that of the unpatterned OLED.

  19. Synthesis of unsymmetric bipyridine-Pt(II) -alkynyl complexes through post-click reaction with emission enhancement characteristics and their applications as phosphorescent organic light-emitting diodes.

    Science.gov (United States)

    Li, Yongguang; Tsang, Daniel Ping-Kuen; Chan, Carmen Ka-Man; Wong, Keith Man-Chung; Chan, Mei-Yee; Yam, Vivian Wing-Wah

    2014-10-13

    Two unsymmetric bipyridine-platinum(II)-alkynyl complexes have been synthesised by a post-click reaction. These metal complexes are found to exhibit emission enhancement properties. The photoluminescence quantum yield can be significantly increased from 0.03 in solution to 0.72 in solid-state thin films. Efficient solution-processable organic light-emitting diodes have been fabricated by utilizing these complexes as phosphorescent dopants. A high external quantum efficiency of up to 5.8% has been achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Detailed Characteristics of Radiation Belt Electrons Revealed by CSSWE/REPTile Measurements

    Science.gov (United States)

    Zhang, K.; Li, X.; Schiller, Q.; Gerhardt, D. T.; Millan, R. M.

    2016-12-01

    The outer radiation belt electrons are highly dynamic. We study the detailed characteristics of the relativistic electrons in the outer belt using measurements from the Colorado Student Space Weather Experiment (CSSWE) mission, a low Earth orbit Cubesat, which transverses the radiation belt four times in one orbit ( 1.5 hr) and has the advantage of measuring the dynamic activities of the electrons including their rapid precipitations. Among the features of the relativistic electrons, we show the measured electron distribution as a function of geomagnetic activities and local magnetic field strength. Moreover, a specific precipitation band, which happened on 19 Jan 2013, is investigated based on the conjunctive measurement of CSSWE and the Balloon Array for Radiation belt Relativistic Electron Losses (BARREL). In this precipitation band event, the net loss of the 0.58 1.63 MeV electrons (L=3.5 6) is estimated to account for 6.84% of the total electron content.

  1. Radiation-hardened optically reconfigurable gate array exploiting holographic memory characteristics

    Science.gov (United States)

    Seto, Daisaku; Watanabe, Minoru

    2015-09-01

    In this paper, we present a proposal for a radiation-hardened optically reconfigurable gate array (ORGA). The ORGA is a type of field programmable gate array (FPGA). The ORGA configuration can be executed by the exploitation of holographic memory characteristics even if 20% of the configuration data are damaged. Moreover, the optoelectronic technology enables the high-speed reconfiguration of the programmable gate array. Such a high-speed reconfiguration can increase the radiation tolerance of its programmable gate array to 9.3 × 104 times higher than that of current FPGAs. Through experimentation, this study clarified the configuration dependability using the impulse-noise emulation and high-speed configuration capabilities of the ORGA with corrupt configuration contexts. Moreover, the radiation tolerance of the programmable gate array was confirmed theoretically through probabilistic calculation.

  2. Dosimetric characteristics and radiation monitoring with CaSO4(Dy):NaCl pellets

    International Nuclear Information System (INIS)

    Kathuria, S.P.; Campos, L.L.; Gordon, A.M.P.L.

    1981-06-01

    CaSO 4 (Dy):NaCl Tl dosimeters, in the form of pellets, are used in the field for a period of one month. Before using these pellets for environmental and personnel radiation monitoring some of the important dosimetric characteristics like fading reusability and effect of ambient light are investigated and described. The pellets are used with plastic and lead filters for personnel and environmental radiation monitoring and the results obtained with the lead filters are in good agreement with those of the energy independent LiF dosimeters. A new combination of plastic, aluminium and lead filters is suggested for dose measurements in a mixed field of X, gamma and beta radiations. (Author) [pt

  3. Improvement of radiation response characteristic on CdTe detectors using fast neutron irradiation

    International Nuclear Information System (INIS)

    Miyamaru, Hiroyuki; Takahashi, Akito; Iida, Toshiyuki

    1999-01-01

    The treatment of fast neutron pre-irradiation was applied to a CdTe radiation detector in order to improve radiation response characteristic. Electron transport property of the detector was changed by the irradiation effect to suppress pulse amplitude fluctuation in risetime. Spectroscopic performance of the pre-irradiated detector was compared with the original. Additionally, the pre-irradiated detector was employed with a detection system using electrical signal processing of risetime discrimination (RTD). Pulse height spectra of 241 Am, 133 Ba, and 137 Cs gamma rays were measured to examine the change of the detector performance. The experimental results indicated that response characteristic for high-energy photons was improved by the pre-irradiation. The combination of the pre-irradiated detector and the RTD processing was found to provide further enhancement of the energy resolution. Application of fast neutron irradiation effect to the CdTe detector was demonstrated. (author)

  4. Characteristics of the chrome-tanned sheep leather treated by radiation-induced graft of BA

    International Nuclear Information System (INIS)

    Zhou Dezhong; Deng Yongzhen; Li Ying

    1986-01-01

    The characteristics of the chrome-tanned sheep leather treated by radiation-induced graft of BA is presented. Using the method of radiation-induced graft of BA instead of the chrome-retanning, the leather has been obviously improved not only in the surface, such as the brightness, fullness, uniformity of the thickness but also in the physical characteristics such as retaining of tensile strength, decreasing of water absorption after being immersed in water for 2h, and 24h, enhancement of tearing strength and stitch tear strength. Although the air permeability and water vapor permeability are a bit worse than the control, however is still in the range of the standard issued by Light Industry Ministry of China

  5. Radiation Characteristics Enhancement of Dielectric Resonator Antenna Using Solid/Discrete Dielectric Lenses

    Directory of Open Access Journals (Sweden)

    H. A. E. Malhat

    2015-02-01

    Full Text Available The radiation characteristics of the dielectric resonator antennas (DRA is enhanced using different types of solid and discrete dielectric lenses. One of these approaches is by loading the DRA with planar superstrate, spherical lens, or by discrete lens (transmitarray. The dimensions and dielectric constant of each lens are optimized to maximize the gain of the DRA. A comparison between the radiations characteristics of the DRA loaded with different lenses are introduced. The design of the dielectric transmitarray depends on optimizing the heights of the dielectric material of the unit cell. The optimized transmitarray achieves 7 dBi extra gain over the single DRA with preserving the circular polarization. The proposed antenna is suitable for various applications that need high gain and focused antenna beam.

  6. Effects of ionizing radiation in the physico-chemical characteristics of red wine Cabernet Sauvignon

    International Nuclear Information System (INIS)

    Silva, Fellipe Souza da; Leiras, Anderson; Wagner, Walsan

    2014-01-01

    The oenology in the current days is increasingly aimed obtain improvements on wine quality produced without there the deterioration of characteristics of the same, using new technologies for such order. The objective of present work will be the application of the radiation ionizing in wines Cabernet Sauvignon, with the interest of analyzing its effects on physic-chemical characteristics of this wines, such as quality, aging and etc. Were analyzed the following strands: degree alcoholic; dry extract; density and absorbance with spectrometer (420, 520 and 620 nm). (author)

  7. Electromagnetic Radiation of Electrons in Periodic Structures

    CERN Document Server

    Potylitsyn, Alexander Petrovich

    2011-01-01

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

  8. Some physico-chemical characteristics of a modified histone H2b on acute radiation affection

    International Nuclear Information System (INIS)

    Khrapunov, S.N.; Mel'nik, G.G.; Blyum, Ya.B.; Tsudzevich, B.A.; Kucherenko, N.E.

    1980-01-01

    A study was made of optical characteristics of histone H2b isolated from liver nuclei 12 h following irradiation in a dose of 0.21 C/kg. It was demonstrated that under similar conditions, the control and exposed histones H2b have different steric organization which correlates with radiation-induced modifications of lateral radicals in H2b histone molecules

  9. Analyses of the radiation-caused characteristics change in SOI MOSFETs using field shield isolation

    International Nuclear Information System (INIS)

    Hirano, Yuuichi; Maeda, Shigeru; Fernandez, Warren; Iwamatsu, Toshiaki; Yamaguchi, Yasuo; Maegawa, Shigeto; Nishimura, Tadashi

    1999-01-01

    Reliability against radiation ia an important issue in silicon on insulator metal oxide semiconductor field effect transistors (SOI MOSFETs) used in satellites and nuclear power plants and so forth which are severely exposed to radiation. Radiation-caused characteristic change related to the isolation-edge in an irradiated environment was analyzed on SOI MOSFETs. Moreover short channel effects for an irradiated environment were investigated by simulations. It was revealed that the leakage current which was observed in local oxidation of silicon (LOCOS) isolated SOI MOSFETs was successfully suppressed by using field shield isolation. Simulated potential indicated that the potential rise at the LOCOS edge can not be seen in the case of field shield isolation edge which does not have physical isolation. Also it was found that the threshold voltage shift caused by radiation in short channel regime is severer than that in long regime channel. In transistors with a channel length of 0.18μm, a potential rise of the body region by radiation-induced trapped holes can be seen in comparison with that of 1.0μm. As a result, we must consider these effects for designing deep submicron devices used in an irradiated environment. (author)

  10. Some characteristics of protons emitted in backward hemisphere in dTa and CTa interactions at Psub(0)=4.2 GeV/c

    International Nuclear Information System (INIS)

    Gasparyan, A.P.; Mekhtiev, R.R.

    1985-01-01

    In interactions of deuterium and carbon relativistic nuclei with tantalum at P 0 =4.2 GeV/c for secondary protons with 100 deg emission angle in lab. system, the temperature of proton kinetic energy spectra in three angle intervals has been determined. It does not contradict the values obtained in hadron-nuclear interactions. The slope parameters for backward emitted proton spectra over comulative variable β=/E-psub(11) msub(p) in dTa and CTa collisions and hadron-nucleus interactions are approximately equal as well. At the same time some difference of s: ope parameters on kinetic energy and cumulative variables spectra between dTa and CTa is observed. In CTa collisions the spectra are deeper. The comparison with the predictions of cascade model for CTa interactions is made. The cascade model taking into account the final state interaction of nucleons on the whole satisfactorily describes the experimental data

  11. Thermal Characteristics of InGaN/GaN Flip-Chip Light Emitting Diodes with Diamond-Like Carbon Heat-Spreading Layers

    Directory of Open Access Journals (Sweden)

    Pai-Yang Tsai

    2014-01-01

    Full Text Available The temperature-dependent optical, electrical, and thermal properties of flip-chip light emitting diodes (FCLEDs with diamond-like carbon (DLC heat-spreading layers were investigated. On the basis of the measured results in the 20°C to 100°C temperature range, a significant performance improvement can be achieved for FCLEDs with DLC heat-spreading layers (DLC-FCLED compared with FCLEDs without DLC heat-spreading layers (non-DLC-FCLED. The external quantum efficiency (EQE of the DLC-FCLED improves by 9% at an injection current of 1000 mA and a temperature of 100°C. The forward voltage and spectra variations are smaller than those of non-DLC-FCLEDs. The DLC-FCLED provides high efficiency and high stability performance for high-power and high-temperature applications.

  12. Photoluminescence characteristics of Sm{sup 3+} doped Ba{sub 3}La(PO{sub 4}){sub 3} as new orange-red emitting phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ruijin [College of Science, Northwest A and F University, Yangling, Shaanxi 712100 (China); Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Mi Noh, Hyeon; Kee Moon, Byung; Chun Choi, Byung [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Hyun Jeong, Jung, E-mail: jhjeong@pknu.ac.kr [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Sueb Lee, Ho [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jang, Kiwan, E-mail: kwjang@changwon.ac.kr [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Soo Yi, Soung [Department of Electronic Material Engineering, Silla University, Busan 617-736 (Korea, Republic of)

    2014-01-15

    A series of orange-red emitting Ba{sub 3}La(PO{sub 4}){sub 3}:xSm{sup 3+} (0.01≤x≤0.30) phosphors was synthesized by the convenient solid-state reaction. X-ray diffraction and photoluminescence spectra were utilized to characterize the structure and luminescence properties of the as-synthesized phosphors. The emission spectra of the Ba{sub 3}La(PO{sub 4}){sub 3}:Sm{sup 3+} phosphors consisted of some sharp emission peaks of Sm{sup 3+} ions centered at 563 nm, 600 nm, 647 nm, 710 nm. The strongest one is located at 600 nm due to {sup 4}G{sub 5/2}–{sup 6}H{sub 7/2} transition of Sm{sup 3+}, generating bright orange-red light. The optimum dopant concentration of Sm{sup 3+} ions in Ba{sub 3}La(PO{sub 4}):xSm{sup 3+} is around 5 mol% and the critical transfer distance of Sm{sup 3+} is calculated as 22 Å. The CIE chromaticity coordinates of the Ba{sub 3}La(PO{sub 4}){sub 3}:0.05Sm{sup 3+} phosphors was is located in the orange reddish region. The Ba{sub 3}La(PO{sub 4}){sub 3}:Sm{sup 3+} phosphors may be potentially used as red phosphors for white light-emitting diodes. -- Highlights: • A new Sm{sup 3+}-doped Ba{sub 3}La(PO{sub 4}){sub 3} phosphor was firstly synthesized. • Its structure, luminescent properties are well studied and characterized. • The Ba{sub 3}La(PO{sub 4}){sub 3}:Sm{sup 3+} shows bright orange reddish emissions under UV excitation.

  13. Effect of ionizing radiations on some organoleptic characteristics of edible mushroom

    International Nuclear Information System (INIS)

    Kovacs, E.; Vas, K.

    1974-01-01

    Organoleptic characteristics - colour, odour, flavour and texture - of edible mushrooms (Agaricus bisporus) in different stages of ripeness (half-ripe, ripe) were examined as a function of radiation dose, storage time as well as storage temperature, and humidity (3-5 0 C, 70-90% RH; 16 0 C, 65-75% RH). Immediately after irradiation the mushrooms assumed a slight brownish hue which, however, did not change on further storage. The brown discoloration of untreated mushroom progressed in the course of storage. The colour of the irradiated mushroom scarcely changed with storage time, tested on the 6th, 11th or 13th day. Other properties examined (odour, flavour, texture) were not affected by irradiation, either immediately upon treatment or during further storage. Ionizing radiation was found to exert favourable influence upon the organoleptic properties of picked mushrooms, and to delay the deterioration of these properties. Radiation treatment was found to preserve the characteristic mushroom odour and this is considered an advantage in canning. (F.J.)

  14. Spectral Cauchy characteristic extraction of strain, news and gravitational radiation flux

    International Nuclear Information System (INIS)

    Handmer, Casey J; Szilágyi, Béla; Winicour, Jeffrey

    2016-01-01

    We present a new approach for the Cauchy-characteristic extraction (CCE) of gravitational radiation strain, news function, and the flux of the energy–momentum, supermomentum and angular momentum associated with the Bondi–Metzner–Sachs asymptotic symmetries. In CCE, a characteristic evolution code takes numerical data on an inner worldtube supplied by a Cauchy evolution code, and propagates it outwards to obtain the space–time metric in a neighborhood of null infinity. The metric is first determined in a scrambled form in terms of coordinates determined by the Cauchy formalism. In prior treatments, the waveform is first extracted from this metric and then transformed into an asymptotic inertial coordinate system. This procedure provides the physically proper description of the waveform and the radiated energy but it does not generalize to determine the flux of angular momentum or supermomentum. Here we formulate and implement a new approach which transforms the full metric into an asymptotic inertial frame and provides a uniform treatment of all the radiation fluxes associated with the asymptotic symmetries. Computations are performed and calibrated using the spectral Einstein code. (paper)

  15. Emitting recombination of BCl molecules with chlorine atoms, resulting from dissociation of boron trichloride molecules under action of pulse CO2-laser radiation

    International Nuclear Information System (INIS)

    Nikonorov, A.P.; Moskvitina, E.N.; Kuzyakov, Yu.Ya.; Stepanov, P.I.

    1983-01-01

    Luminescence in BCl 3 is investigated. The results of measurements of gas temperature, BCl molecules concentration, and luminescence absolute intensity at boron trichloride presure of 40 mm pH and density of laser pulse energy from 1.7 up to 4.0 J/cm 2 are obtained. Nature of uninterrupted spectrum is considered. It is established that luminescence appearing in the BCl 3 under action of pulse CO 2 -laser is caused by reaction of emitting recombination of BCl molecules with chlorine atoms. Rate constant of this reaction in the range of 2300-3100 K is determined

  16. Radiation detectors based by polymer materials

    International Nuclear Information System (INIS)

    Cherestes, Margareta; Cherestes, Codrut; Constantinescu, Livia

    2004-01-01

    Scintillation counters make use of the property of certain chemical compounds to emit short light pulses after excitation produced by the passage of charged particles or photons of high energy. These flashes of light are detected by a photomultiplier tube that converts the photons into a voltage pulse. The light emitted from the detector also can be collected, focussed and dispersed by a CCD detector. The study of the evolution of the light emission and of the radiation damage under irradiation is a primary topic in the development of radiation hard polymer based scintillator. Polymer scintillator thin films are used in monitoring radiation beam intensities and simultaneous counting of different radiations. Radiation detectors have characteristics which depend on: the type of radiation, the energy of radiation, and the material of the detector. Three types of polymer thin films were studied: a polyvinyltoluene based scintillator, fluorinated polyimide and PMMA. (authors)

  17. Effect of the ionizing radiation in the sensorial characteristics of the pineapple

    International Nuclear Information System (INIS)

    Silva, Josenilda Maria da; Spoto, Marta Helena Fillet; Silva, Juliana Pizarro

    2007-01-01

    The post-harvest quality of the pineapple cultivar Smooth Cayenne was evaluated after the fruit was irradiated with doses of 100 and 150 Gy and stored for 10, 20 and 30 days at 12 deg C ( +-1) and relative humidity of 85% (+- 5). The controls were untreated fruits. Sensorial analyses were made for each storage period to obtain information about the effects of ionizing radiation on the quality of the fruit. The ionizing radiation dosage had little effect on the sensorial characteristics of the pineapple, although the best results were obtained with fruit irradiated with 100 Gy. The 20-day storage period resulted in the highest consumer acceptability, while the 30-day storage period impaired the fruit's external and internal appearance. (author)

  18. Dispersion characteristics of planar grating with arbitrary grooves for terahertz Smith-Purcell radiation

    International Nuclear Information System (INIS)

    Cao, Miaomiao; Li, Ke; Liu, Wenxin; Wang, Yong

    2015-01-01

    In this paper, a novel method of getting the dispersion relations in planar grating with arbitrary grooves for terahertz Smith-Purcell radiation is investigated analytically. The continuous profile of the groove is approximately replaced by a series of rectangular steps. By making use of field matches method and the continuity of transverse admittance, the universal dispersion equation for grating with arbitrarily shaped grooves is derived. By solving the dispersion equation in presence of electron beam, the growth rate is obtained directly and the dependence on beam parameters is analyzed. Comparisons of the dispersion characteristics among some special groove shapes have been made by numerical calculation. The results show that the rectangular-step approximation method provides a novel approach to obtain the universal dispersion relation for grating with arbitrary grooves for Smith-Purcell radiation

  19. Scintillation characteristics of phosphich-detector for detection of beta- and gamma-radiations

    CERN Document Server

    Ananenko, A A; Gavrilyuk, V

    2002-01-01

    The results of the study on the influence of individual peculiarities of the compound scintillation detector structure on the value and stability of the light yield by the gamma- and beta-radiation combined registration are presented. The phosphich detector is manufactured from the sodium iodide monocrystal, activated by thallium, and the scintillation plastic on the polystyrol basis. The comparison of the experimental results with the mathematical modeling data revealed certain regularities of the process of forming the phosphich detector light signal. The recommendations are worked out by means whereof the following characteristics of the scintillation unit: the light yield and its stability, amplitude resolution and the peak-to-valley ratio by the gamma- and beta-radiation registration were improved

  20. Development of high voltage PEEK wire with radiation-resistance and cryogenic characteristics

    International Nuclear Information System (INIS)

    Fujita, T.; Hirata, T.; Araki, S.; Ohara, H.; Nishimura, H.

    1989-01-01

    High voltage electric wires insulated with highly-refined polyetheretherketone (PEEK) have been developed for the wiring in fusion reactors, where the wire is required to withstand high voltage under high vacuum up to 10 -5 Torr. The PEEK wires having the advantages of PEEK resin including superior radiation resistance and cryogenic characteristics are usable over a wide range of temperature and in radiation fields. The results of withstand voltage tests proved that the PEEK wires exceeding 0.8 mm in insulation thickness withstand such specified high voltage conditions as 24 kV for 1 minutes by 10 times and 6.6 kV for 110 hours. The results also revealed that the withstand voltage is improved by providing a jacket layer over the insulation and decreased by periodical voltage charge, by bending of the specimen and by water in the conductor. This paper deal with the withstand voltage test results under varied conditions of the PEEK wires. (author)

  1. Factors determining differences in biological effectiveness of ionizing radiations possessing different physical characteristics

    International Nuclear Information System (INIS)

    Korogodin, V.I.; Krasavin, E.A.

    1982-01-01

    Radiosensitivity of pro- and eukaryotes (D 0- 1 ) is considered with regard to the linear energy transfer (LET) of ionizing radiations. It was shown that radiosensitivity, as a function of LET, D 0- 1 (LET), is determined by not merely physical characteristics of radiations but also the ability of repair of DNA double strand breaks (DSB). The increase in the radiosensitivity of eukaryotes is connected with the decrease in the DSB repair when cells are exposed to densely ionizing particles. The decrease in DSB repair is apparently connected with the increment of straight DSB, comparing to enzymatic DSB, upon exposure to heavy ions. Potential mechanisms of D 0- 1 (LET) modifications for radiosensitive and superresistant mutants are discussed

  2. Emission and profile characteristic of volatile organic compounds emitted from coke production, iron smelt, heating station and power plant in Liaoning Province, China.

    Science.gov (United States)

    Shi, Jianwu; Deng, Hao; Bai, Zhipeng; Kong, Shaofei; Wang, Xiuyan; Hao, Jiming; Han, Xinyu; Ning, Ping

    2015-05-15

    107 kinds of C₂-C₁₂ volatile organic compound (VOC) mass concentrations and profiles for four types of coal-fired stationary sources in Liaoning Province were studied by a dilution sampling system and GC-MS analysis method, which are of significant importance with regard to VOC emissions in northeast of China. The results showed that there were some differences among these VOC source profiles. The total mass concentrations of analyzed 107 VOC species varied from 10,917 to 19,652 μg m(-3). Halogenated hydrocarbons exhibited higher mass percentages for the VOC source profiles of iron smelt (48.8%) and coke production plant (37.7%). Aromatic hydrocarbons were the most abundant in heating station plant (69.1%). Ketones, alcohols and acetates held 45.0% of total VOCs in thermal power plant. For non-methane hydrocarbons (NMHCs), which are demanded for photochemical assessment in the USA, toluene and n-hexane were the most abundant species in the iron smelt, coke production and thermal power plant, with the mass percentages of 64.8%, 52.7% and 38.6%, respectively. Trimethylbenzene, n-propylbenzene and o,m-ethyltoluene approximately accounted for 70.0% in heating station plant. NMHCs emitted from coke production, iron smelt, heating station and power plant listed above presented different chemical reactivities. The average OH loss rate of NMHCs from heating station, was 4 to 5.6 times higher than that of NMHCs from iron smelt, coke production and power plant, which implies that VOCs emitted from heating station in northeast of China should be controlled firstly to avoid photochemical ozone pollution and protect human health. There are significant variations in the ratios of benzene/toluene and m, p-xylene/ethylbenzene of these coal-fired source profiles. The representativeness of the coal-fired sources studied and the VOC samples collected should be more closely examined. The accuracy of VOC source profiles related to coal-fired processes is highly dependent on

  3. Photoluminescence characteristics of Sm{sup 3+}-doped Ba{sub 2}CaWO{sub 6} as new orange–red emitting phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ruiijn [College of Science, Northwest A and F University, Yangling, Shaanxi 712100 (China); Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Mi Noh, Hyeon; Kee Moon, Byung; Chun Choi, Byung [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Hyun Jeong, Jung, E-mail: jhjeong@pknu.ac.kr [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Sueb Lee, Ho [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jang, Kiwan, E-mail: kwjang@changwon.ac.kr [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Soo Yi, Soung [Department of Electronic Material Engineering, Silla University, Busan 617-736 (Korea, Republic of)

    2014-08-01

    The orange–red emitting Ba{sub 2}CaWO{sub 6}:xSm{sup 3+} (0.01≤x≤0.25) phosphors were synthesized via solid state reaction process. The crystal structure of the phosphor was characterized by XRD. The photoluminescence excitation and emission spectra, concentration effect were investigated. The results show an efficient energy transfer from WO{sub 6}{sup 6−} group to Sm{sup 3+} occurs. The emission spectra of the Ba{sub 2}CaWO{sub 6}:Sm{sup 3+} phosphors consisted of some sharp emission peaks of Sm{sup 3+} ions centre at 579 nm, 618 nm, 625 nm, and 675 nm. The strongest one is located at 610 nm due to {sup 4}G{sub 5/2}→{sup 6}H{sub 7/2} transition of Sm{sup 3+}, generating bright orange–red light. The optimum dopant concentration of Sm{sup 3+} ions in Ba{sub 2}CaWO{sub 6}:xSm{sup 3+} is around 5 mol% and the critical transfer distance of Sm{sup 3+} is calculated as 18 Å. The fluorescence lifetime of Sm{sup 3+} in Ba{sub 2}CaWO{sub 6}:0.05Sm{sup 3+} is 2.36 ms. The Ba{sub 2}CaWO{sub 6}:Sm{sup 3+} phosphors may be potentially used as orange–red phosphors for white light-emitting diodes. - Highlights: • A new host-sensitized Sm{sup 3+}-doped Ba{sub 2}CaWO{sub 6} phosphor was firstly synthesized. • Its structure, luminescent properties are well studied and characterized. • There exists an efficient energy transfer from WO{sub 6}{sup 6−} group to Sm{sup 3+}. • The thermal quenching properties of Ba{sub 2}CaWO{sub 6}:Sm{sup 3+} was firstly evaluated.

  4. Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli.

    Science.gov (United States)

    Taheri, M; Mortazavi, S M J; Moradi, M; Mansouri, S; Hatam, G R; Nouri, F

    2017-01-01

    Mobile phones and Wi-Fi radiofrequency radiation are among the main sources of the exposure of the general population to radiofrequency electromagnetic fields (RF-EMF). Previous studies have shown that exposure of microorganisms to RF-EMFs can be associated with a wide spectrum of changes ranged from the modified bacterial growth to the alterations of the pattern of antibiotic resistance. Our laboratory at the nonionizing department of the Ionizing and Non-ionizing Radiation Protection Research Center has performed experiments on the health effects of exposure to animal models and humans to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons, magnetic resonance imaging, and Helmholtz coils. On the other hand, we have previously studied different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. In this study, we assessed if the exposure to 900 MHz GSM mobile phone radiation and 2.4 GHz radiofrequency radiation emitted from common Wi-Fi routers alters the susceptibility of microorganisms to different antibiotics. The pure cultures of Listeria monocytogenes and Escherichia coli were exposed to RF-EMFs generated either by a GSM 900 MHz mobile phone simulator and a common 2.4 GHz Wi-Fi router. It is also shown that exposure to RF-EMFs within a narrow level of irradiation (an exposure window) makes microorganisms resistant to antibiotics. This adaptive phenomenon and its potential threats to human health should be further investigated in future experiments. Altogether, the findings of this study showed that exposure to Wi-Fi and RF simulator radiation can significantly alter the inhibition zone diameters and growth rate for L monocytogenes and E coli. These findings may have implications for the management of serious infectious diseases.

  5. A multi-layer discrete-ordinate method for vector radiative transfer in a vertically-inhomogeneous, emitting and scattering atmosphere. I - Theory. II - Application

    Science.gov (United States)

    Weng, Fuzhong

    1992-01-01

    A theory is developed for discretizing the vector integro-differential radiative transfer equation including both solar and thermal radiation. A complete solution and boundary equations are obtained using the discrete-ordinate method. An efficient numerical procedure is presented for calculating the phase matrix and achieving computational stability. With natural light used as a beam source, the Stokes parameters from the model proposed here are compared with the analytical solutions of Chandrasekhar (1960) for a Rayleigh scattering atmosphere. The model is then applied to microwave frequencies with a thermal source, and the brightness temperatures are compared with those from Stamnes'(1988) radiative transfer model.

  6. Radiation characteristics of input power from surface wave sustained plasma antenna

    Energy Technology Data Exchange (ETDEWEB)

    Naito, T., E-mail: Naito.Teruki@bc.MitsubishiElectric.co.jp [Advanced Technology R& D Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Yamaura, S. [Information Technology R& D Center, Mitsubishi Electric Corporation, Kamakura, Kanagawa 247-8501 (Japan); Fukuma, Y. [Communication System Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Sakai, O. [Department of Electronic System Engineering, The University of Shiga Prefecture, Hikone, Shiga 522-8533 (Japan)

    2016-09-15

    This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

  7. Radiation characteristics of input power from surface wave sustained plasma antenna

    International Nuclear Information System (INIS)

    Naito, T.; Yamaura, S.; Fukuma, Y.; Sakai, O.

    2016-01-01

    This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

  8. Simulating the spectrum and the polarization characteristics of coherent radiation from ultrarelativistic electrons in a diamond crystal

    International Nuclear Information System (INIS)

    Truten', V.I.

    2000-01-01

    On the basis of a computer simulation, it is shown that, in the spectrum of radiation from ultrarelativistic electrons in oriented crystals, new maxima can appear in the low-frequency region in addition to ordinary coherent maxima. This effect is due to the influence of high-index planes on the radiation in question. The aforementioned new maxima manifest themselves not only in the spectrum but also in the polarization characteristics of the radiation

  9. Social, economic and political aspects of Chernobyl in Bulgaria - One characteristic feature of the development of the radiation situation

    International Nuclear Information System (INIS)

    Belokonski, I.I.; Bosevski, V.; Bontchev, Tz.; Marinov, V.

    1997-01-01

    It is shown a characteristic feature of the progress of radiation situation in Bulgaria after the failure in Chernobyl, as this was discussed untraditionally. The raised radiation risk for population during one year after the incident is interpreted as function from the inadequate radiation protection policy of the Government at that time. Preconditions for some social, economical and political results after the accident for Bulgarian country are described

  10. Conceptualisation of the characteristics of advanced practitioners in the medical radiation professions

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Tony [University of Newcastle Department of Rural Health, Taree, New South Wales (Australia); Harris, Jillian [Crown Princess Mary Cancer Centre, Westmead, Sydney, New South Wales (Australia); Woznitza, Nick [Homerton University Hospital and School of Allied Health Professions, Canterbury Christ Church University, Canterbury (Australia); Maresse, Sharon [Department of Imaging and Applied Physics, Curtin University, Perth, Western Australia (Australia); Sale, Charlotte [School of Medical Science, RMIT University, Melbourne, Victoria (Australia); University of Newcastle Department of Rural Health, Taree, New South Wales (Australia)

    2015-09-15

    Professions grapple with defining advanced practice and the characteristics of advanced practitioners. In nursing and allied health, advanced practice has been defined as ‘a state of professional maturity in which the individual demonstrates a level of integrated knowledge, skill and competence that challenges the accepted boundaries of practice and pioneers new developments in health care’. Evolution of advanced practice in Australia has been slower than in the United Kingdom, mainly due to differences in demography, the health system and industrial relations. This article describes a conceptual model of advanced practitioner characteristics in the medical radiation professions, taking into account experiences in other countries and professions. Using the CanMEDS framework, the model includes foundation characteristics of communication, collaboration and professionalism, which are fundamental to advanced clinical practice. Gateway characteristics are: clinical expertise, with high level competency in a particular area of clinical practice; scholarship and teaching, including a masters qualification and knowledge dissemination through educating others; and evidence-based practice, with judgements made on the basis of research findings, including research by the advanced practitioner. The pinnacle of advanced practice is clinical leadership, where the practitioner has a central role in the health care team, with the capacity to influence decision making and advocate for others, including patients. The proposed conceptual model is robust yet adaptable in defining generic characteristics of advanced practitioners, no matter their clinical specialty. The advanced practice roles that evolve to meet future health service demand must focus on the needs of patients, local populations and communities.

  11. Conceptualisation of the characteristics of advanced practitioners in the medical radiation professions

    International Nuclear Information System (INIS)

    Smith, Tony; Harris, Jillian; Woznitza, Nick; Maresse, Sharon; Sale, Charlotte

    2015-01-01

    Professions grapple with defining advanced practice and the characteristics of advanced practitioners. In nursing and allied health, advanced practice has been defined as ‘a state of professional maturity in which the individual demonstrates a level of integrated knowledge, skill and competence that challenges the accepted boundaries of practice and pioneers new developments in health care’. Evolution of advanced practice in Australia has been slower than in the United Kingdom, mainly due to differences in demography, the health system and industrial relations. This article describes a conceptual model of advanced practitioner characteristics in the medical radiation professions, taking into account experiences in other countries and professions. Using the CanMEDS framework, the model includes foundation characteristics of communication, collaboration and professionalism, which are fundamental to advanced clinical practice. Gateway characteristics are: clinical expertise, with high level competency in a particular area of clinical practice; scholarship and teaching, including a masters qualification and knowledge dissemination through educating others; and evidence-based practice, with judgements made on the basis of research findings, including research by the advanced practitioner. The pinnacle of advanced practice is clinical leadership, where the practitioner has a central role in the health care team, with the capacity to influence decision making and advocate for others, including patients. The proposed conceptual model is robust yet adaptable in defining generic characteristics of advanced practitioners, no matter their clinical specialty. The advanced practice roles that evolve to meet future health service demand must focus on the needs of patients, local populations and communities

  12. Evaluation of the Effects of Prostate Radiation Therapy on Occludin Expression and Ultrasonography Characteristics of the Bladder

    DEFF Research Database (Denmark)

    Baradaran-Ghahfarokhi, Milad; Amouheidari, Alireza; Shahbazi-Gahrouei, Daryoush

    2017-01-01

    PURPOSE: To evaluate the effects of radiation dose in prostate radiation therapy (RT) on occludin expression and ultrasonography characteristics of the bladder. METHODS AND MATERIALS: Urine samples of 64 prostate RT patients were collected before, at regular intervals during, and 3 months after R...

  13. Emission Characteristics of InGaN/GaN Core-Shell Nanorods Embedded in a 3D Light-Emitting Diode.

    Science.gov (United States)

    Jung, Byung Oh; Bae, Si-Young; Lee, Seunga; Kim, Sang Yun; Lee, Jeong Yong; Honda, Yoshio; Amano, Hiroshi

    2016-12-01

    We report the selective-area growth of a gallium nitride (GaN)-nanorod-based InGaN/GaN multiple-quantum-well (MQW) core-shell structure embedded in a three-dimensional (3D) light-emitting diode (LED) grown by metalorganic chemical vapor deposition (MOCVD) and its optical analysis. High-resolution transmission electron microscopy (HR-TEM) observation revealed the high quality of the GaN nanorods and the position dependence of the structural properties of the InGaN/GaN MQWs on multiple facets. The excitation and temperature dependences of photoluminescence (PL) revealed the m-plane emission behaviors of the InGaN/GaN core-shell nanorods. The electroluminescence (EL) of the InGaN/GaN core-shell-nanorod-embedded 3D LED changed color from green to blue with increasing injection current. This phenomenon was mainly due to the energy gradient and deep localization of the indium in the selectively grown InGaN/GaN core-shell MQWs on the 3D architecture.

  14. The Measurement of Spectral Characteristics and Composition of Radiation in Atlas with MEDIPIX2-USB Devices

    Science.gov (United States)

    Campbell, M.; Doležal, Z.; Greiffenberg, D.; Heijne, E.; Holy, T.; Idárraga, J.; Jakůbek, J.; Král, V.; Králík, M.; Lebel, C.; Leroy, C.; Llopart, X.; Lord, G.; Maneuski, D.; Ouellette, O.; Sochor, V.; Pospíšil, S.; Suk, M.; Tlustos, L.; Vykydal, Z.; Wilhelm, I.

    2008-06-01

    A network of devices to perform real-time measurements of the spectral characteristics and composition of radiation in the ATLAS detector and cavern during its operation is being built. This system of detectors will be a stand alone system fully capable of delivering real-time images of fluxes and spectral composition of different particle species including slow and fast neutrons. The devices are based on MEDIPIX2 pixel silicon detectors that will be operated via active USB cables and USB-Ethernet extenders through an Ethernet network by a PC located in the USA15 ATLAS control room. The installation of 14 devices inside ATLAS (detector and cavern) is in progress.

  15. The Measurement of Spectral Characteristics and Composition of Radiation in ATLAS with MEDIPIX2-USB Devices

    CERN Document Server

    Campbell, M.; Greiffenberg, D.; Heijne, E.; Holy, T.; Idárraga, J.; Jakubek, J.; Král, V.; Králík, M.; Lebel, C.; Leroy, C.; Llopart, X.; Lord, G.; Maneuski, D.; Ouellette, O.; Sochor, V.; Prospísil, S.; Suk, M; Tlustos, L.; Vykydal, Z.; Wilhelm, I.

    2008-01-01

    A network of devices to perform real-time measurements of the spectral characteristics and composition of radiation in the ATLAS detector and cavern during its operation is being built. This system of detectors will be a stand alone system fully capable of delivering real-time images of fluxes and spectral composition of different particle species including slow and fast neutrons. The devices are based on MEDIPIX2 pixel silicon detectors that will be operated via active USB cables and USB-Ethernet extenders through an Ethernet network by a PC located in the USA15 ATLAS control room. The installation of 14 devices inside ATLAS (detector and cavern) is in progress.

  16. Propagation and radiation characteristics of the circular electric, circular magnetic and hybrid waveguide modes

    International Nuclear Information System (INIS)

    Crenn, J.P.

    1996-06-01

    The field distributions and propagation constants of the circular electric, circular magnetic and hybrid modes of oversized waveguides are expressed, taking the effects of walls into account. The near and far field patterns are derived in the case of real wall functions. It is shown that, for very oversized waveguides, the terms containing wall functions can be ignored in the calculations, and it results that the expressions of fields and propagation constants become independent of the types of waveguides. An application to corrugated waveguides for Electron Cyclotron Resonance Heating experiments shows the variations of the radiation characteristics versus geometric parameters of the corrugations and determines the ranges of interest for these parameters. (author)

  17. Characteristics of x-ray radiation from a gas-puff z-pinch plasma

    International Nuclear Information System (INIS)

    Akiyama, N.; Takasugi, K.

    2002-01-01

    Characteristics of x-ray radiation from Ar gas-puff z-pinch plasma have been investigated by changing delay time of discharge from gas puffing. Intense cloud structure of x-ray image was observed at small delay time region, but the total x-ray signal was not so intense. The x-ray signal increased with increasing the delay time, and hot spots of x-ray image also became intense. Electron temperature was evaluated from x-ray spectroscopic data, and no significant difference in temperature was observed. (author)

  18. Characteristics of porous polymer composite columns prepared by radiation cast-polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao; Asami, Kazuhiro; Suzuki, Shuichi

    1989-01-01

    Porous polymer composite columns having porous structure were prepared by radiation cast-polymerization of hydrophilic monomers at low temperature and their characteristics were studied. The porosity of the polymer increased with decreasing monomer concentration. The elution time of water in the polymer column increased with increasing monomer concentration and with decreasing irradiation temperature. The elution time was dependent on the degree of hydration of the polymer. The polymer with a degree of hydration of 0.2 to 0.4 gave the minimum elution time. The elution time decreased with the addition of porous inorganic substances. (author)

  19. Patterning characteristics of a chemically-amplified negative resist in synchrotron radiation lithography

    International Nuclear Information System (INIS)

    Deguchi, Kimiyoshi; Miyoshi, Kazunori; Ishii, Tetsuyoshi; Matsuda, Tadahito

    1992-01-01

    To explore the applicability of synchrotron radiation X-ray lithography for fabricating sub-quartermicron devices, we investigate the patterning characteristics of the chemically-amplified negative resist SAL601-ER7. Since these characteristics depend strongly on the conditions of the chemical amplification process, the effects of post-exposure baking and developing conditions on sensitivity and resolution are examined. The resolution-limiting factors are investigated, revealing that pattern collapse during the development process and fog caused by Fresnel diffraction, photo-electron scattering, and acid diffusion in the resist determine the resolution and the maximum aspect ratio of the lines and spaces pattern. Using the model of a swaying beam supported at one end, it is shown that pattern collapse depends on the resist pattern's flexural stiffness. Patterning stability, which depends on the delay time between exposure and baking, is also discussed. (author)

  20. Errors and limits in the determination of plasma electron density by measuring the absolute values of the emitted continuum radiation intensity

    International Nuclear Information System (INIS)

    Bilbao, L.; Bruzzone, H.; Grondona, D.

    1994-01-01

    The reliable determination of a plasma electron structure requires a good knowledge of the errors affecting the employed technique. A technique based on the measurements of the absolute light intensity emitted by travelling plasma structures in plasma focus devices has been used, but it can be easily modified to other geometries and even to stationary plasma structures with time-varying plasma densities. The purpose of this work is to discuss in some detail the errors and limits of this technique. Three separate errors are shown: the minimum size of the density structure that can be resolved, an overall error in the measurements themselves, and an uncertainty in the shape of the density profile. (author)

  1. The effects of ultra-thin cerium fluoride film as the anode buffer layer on the electrical characteristics of organic light emitting diodes

    Science.gov (United States)

    Lu, Hsin-Wei; Tsai, Cheng-Che; Hong, Cheng-Shong; Kao, Po-Ching; Juang, Yung-Der; Chu, Sheng-Yuan

    2016-11-01

    In this study, the efficiency of organic light-emitting diodes (OLEDs) was enhanced by depositing a CeF3film as an ultra-thin buffer layer between the indium tin oxide (ITO) electrode and α-naphthylphenylbiphenyldiamine (NPB) hole transport layer, with the structure configuration ITO/CeF3 (0.5, 1, and 1.5 nm)/α-naphthylphenylbiphenyl diamine (NPB) (40 nm)/tris(8-hydroxyquinoline) aluminum (Alq3) (60 nm)/lithium fluoride (LiF) (1 nm)/Al (150 nm). The enhancement mechanism was systematically investigated via several approaches. The X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy results revealed the formation of the UV-ozone treated CeF3 film. The work function increased from 4.8 eV (standard ITO electrode) to 5.22 eV (0.5-nm-thick UV-ozone treated CeF3 film deposited on the ITO electrode). The surface roughness of the UV-ozone treated CeF3 film was smoother than that of the standard ITO electrode. Further, the UV-ozone treated CeF3 film increased both the surface energy and polarity, as determined from contact angle measurements. In addition, admittance spectroscopy measurements showed an increased capacitance and conductance of the OLEDs. Accordingly, the turn-on voltage decreased from 4.2 V to 3.6 V at 1 mA/cm2, the luminance increased from 7588 cd/m2 to 24760 cd/m2, and the current efficiency increased from 3.2 cd/A to 3.8 cd/A when the 0.5-nm-thick UV-ozone treated CeF3 film was inserted into the OLEDs.

  2. Characteristics of the epitaxy of InGaN-based light-emitting diodes grown by nanoscale epitaxial lateral overgrowth using a nitrided titanium buffer layer

    International Nuclear Information System (INIS)

    Shieh, Chen-Yu; Li, Zhen-Yu; Chang, Jenq-Yang; Chi, Gou-Chung

    2015-01-01

    In this work, a buffer layer of nitrided titanium (Ti) achieved through the nitridation of a Ti metal layer on a sapphire substrate was used for the epitaxial growth of InGaN-based light-emitting diodes (LEDs) achieved by low pressure metal-organic chemical vapor deposition. The effect of in-situ Ti metal nitridation on the performance of these InGaN-based LEDs was then investigated. It was very clear that the use of the nitrided Ti buffer layer (NTBL) induced the formation of a nanoscale epitaxial lateral overgrowth layer during the epitaxial growth. When evaluated by Raman spectroscopy, this epi-layer exhibited large in-plane compressive stress releasing with a Raman shift value of 567.9 cm -1 . Cathodoluminescence spectroscopy and transmission electron microscopy results indicated that the InGaN-based LEDs with an NTBL have improved crystal quality, with a low threading dislocations density being yielded via the strain relaxation in the InGaN-based LEDs. Based on the results mentioned above, the electroluminescence results indicate that the light performance of InGaN-based LEDs with an NTBL can be enhanced by 45% and 42% at 20 mA and 100 mA, respectively. These results suggest that the strain relaxation and quality improvement in the GaN epilayer could be responsible for the enhancement of emission power. - Highlights: • The crystal-quality of InGaN-based LEDs with NTBL by NELOG was improved. • The InGaN-based LEDs with NTBL have strain releases by NELOG. • The optical properties of InGaN-based LEDs were shown by CL and EL measurements

  3. Characteristics for heavy ions and micro-dosimetry in radiation detectors

    International Nuclear Information System (INIS)

    Doke, Tadayoshi

    1978-01-01

    The characteristics of radiation detectors for heavy ions generally present more complex aspects as compared with those for electron beam and γ-ray. There is the ''Katz theory'' applying the target theory in radiobiology phenomenologically to radiation detectors. Here, first, the Katz theory for radiation detectors is explained, then its applications to nuclear plates, solid state track detectors, scintillation detectors and thermoluminescence dosimeters are described, respectively. The theory is used for the calibration of the nuclear charge of heavy ions in nuclear plates and recently is used to simulate the flight tracks of heavy ions or magnetic monopoles. In solid state track detectors, the threshold value of the energy given along the tracks of heavy ions is inherent to a detector, and the Katz theory is applicable as the measure of the threshold. The theory seems to be superior to the other methods. However, it has disadvantages that the calculation is not simple and is difficult for wide objects. In scintillation detectors, the scintillation efficiency is not a single function of dE/dx, but depends on the kinds of heavy ions, which Katz succeeded to describe quantitatively with his theory. Such result has also been produced that the dependence of thermoluminescence dosimeters such as LiF on LET by Katz theory agreed fairly well with experiments. (Wakatsuki, Y.)

  4. The characteristics of corrosion, radiation degradation and dissolution of titanium alloys

    International Nuclear Information System (INIS)

    Sung, K. W.; Na, J. W.; Choi, B. S.; Lee, D. J.; Chang, M. H.

    2001-12-01

    In order to establish the technical bases of water chemistry design requirement related titanium alloys, we investigated the characteristics of corrosion, activation, radiation degradation, radiation hydrogen embrittlement of titanium alloys and dissolution of titanium dioxide. Titanium alloys generally have high corrosion resistance. Corrosion product release from PT-7M and PT-3V titanium alloy surface for 18 months of operation is negligible, and the corrosion penetration for about 30 years is about 1 μm, while the corrosion rates is not higher than one third of that of austenitic steel. Titanium only converts into Sc-46 with 85 day halflife after neutron irradiation, and its radioactivity is not higher than one thousandth of that produced from nickel. Therefore, under the condition without any neutron irradiation, the radiation damage of titanium alloys would have no problem. Titanium dioxide, that protects the metals from the corrosion, has retrograde solubility in neutral solutions. It does not form any complexes with ligands such as ammonia, but Ti(IV) gets more stable by complexing with water molecules. In conclusion, it is estimated that titanium alloys such as PT-7M would be applicable to steam generator materials

  5. Investigation of thermo-optical characteristics of the interaction processes of laser radiation with silver nanoparticles

    International Nuclear Information System (INIS)

    Pustovalov, V K; Astafyeva, L G

    2013-01-01

    Metallic nanoparticles have been actively investigated in recent years by different optical and laser methods with the purpose of their applications in optoelectronics and photonics, chemistry, laser nanobiomedicine, optical diagnostics, and other fields. A major role among metallic nanoparticles is played by nanoparticles from the noble metals (silver, gold, etc). These particles have unique plasmonic properties (resonances in the range of wavelength 400–540 nm), which can be used for the absorption, scattering and transformation of laser energy. Analysis of the thermo-optical characteristics of the interaction processes of laser radiation with silver nanoparticles is carried out, taking into account absorption, scattering and extinction of laser radiation by nanoparticles, as well as the thermo-optical and other properties of nanoparticles. Estimations are made of the influence of these nanoparticle properties on the possible results of laser radiation interaction with silver nanoparticles, including heating, heat exchange, possible melting and evaporation, and processes in the ambient media. These results can be used in laser processing of silver nanoparticles and their applications in laser nanomedicine. (paper)

  6. Recent developments in white light emitting diodes

    Science.gov (United States)

    Lohe, P. P.; Nandanwar, D. V.; Belsare, P. D.; Moharil, S. V.

    2018-05-01

    because they can emit visible light strongly under blue light irradiation. These are chemically, thermally and mechanically stable materials with high efficiency to down convert blue radiation into green and red. Efficient white light can be generated by coating these phosphors on blue LED.CRI of white emitting LED lamp can be improved significantly if green and red emitting phosphors are coated on efficient blue emitting LED chips. In this approach CRI will be maintained if appropriate combination of red, green along with blue emission is used. This article reviews some recent developments in phosphors for white light emitting diodes.

  7. An analysis of the radiation field characteristics for extremity dose assessment during maintenance periods at nuclear power plants in Korea

    International Nuclear Information System (INIS)

    Kim, H. G.; Kong, T. Y.

    2012-01-01

    Workers who maintain the water chambers of steam generators during maintenance periods in nuclear power plants (NPPs) have a higher likelihood of high radiation exposure, even if they are exposed for a short period of time. In particular, it is expected that the hands of workers would receive the highest radiation exposure as a consequence of hand contact with radioactive materials. In this study, a characteristic analysis of inhomogeneous radiation fields for contact operations was conducted using thermoluminescent dosemeters for the whole body and extremities during maintenance periods at Korean NPPs. It was observed that inhomogeneous radiation fields for contact operations at NPPs were dominated by high-energy photons. (authors)

  8. Radiation characteristics of a coaxial waveguide with eccentric inner conductor for application in hyperthermia and microwave reflex therapy

    Directory of Open Access Journals (Sweden)

    R. Herschmann

    2007-06-01

    Full Text Available This paper examines the radiation characteristics of a contact emitter conceived for application in hyperthermia and microwave reflex therapy. It is important to analyse the distribution of power density in the near field area, as the radiator's therapeutic sphere of activity is localized here. The contact emitter is a coaxial radiator with an eccentric course of the inner conductor. According to Huygens principle, a theoretical view of the near field radiation characteristics is made by determining the equivalent current densities in the emitter aperture. It is shown that by an eccentric shift of the inner conductor, an almost isotropic near field radiation pattern and power density can be achieved. For this, the electromagnetic field in the emitter aperture is determined by using a Bipolar coordinate system. This calculation considers only the fundamental TEM mode of the contact emitter. Besides the theoretical results near and far fields are simulated using the programme system Ansoft HFSS.

  9. GREEN LIGHT EMITTING TRICOMPONENT LUMINOPHORS OF 2-NAPHTHOL FOR CONSTRUCTION OF ORGANIC LIGHT EMITTING DEVICES

    OpenAIRE

    K. G. MANE , P. B. NAGORE , DR. S. R. PUJARI

    2018-01-01

    This article presents a previous study and incredible progress in basic theoretical modeling, and working for organic light-emitting devices (OLEDs) including preparation and characteristic studies of Organo- Luminescent Materials by conventional solid state reaction technique.

  10. Polymer light emitting diodes

    International Nuclear Information System (INIS)

    Gautier-Thianche, Emmmanuelle

    1998-01-01

    We study sandwich type semiconducting polymer light emitting diodes; anode/polymer/cathode. ITO is selected as anode, this polymer is a blend of a commercially available polymer with a high hole transport ability: polyvinyl-carbazole and a laser dye: coumarin-515. Magnesium covered with silver is chosen for the anode. We study the influence of polymer thickness and coumarin doping ratio on electroluminescence spectrum, electric characteristics and quantum efficiency. An important drawback is that diodes lifetime remains low. In the second part of our study we determine degradations causes with X-Ray reflectivity experiments. It may be due to ITO very high roughness. We realize a new type of planar electroluminescent device: a channel type electroluminescent device in which polymer layer is inserted into an aluminium channel. Such a device is by far more stable than using classical sandwich structures with the same polymer composition: indeed, charges are generated by internal-field ionization and there is no injection from the electrode to the polymer. This avoids electrochemical reactions at electrodes, thus reducing degradations routes. (author) [fr

  11. 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.

  12. Statistical Modeling of Radiative Transfer and Transient Characteristics for Multilayer Biological Tissue

    Directory of Open Access Journals (Sweden)

    S. Yu. Makarov

    2014-01-01

    Full Text Available The Monte-Carlo method [1] already long ago proved itself as a powerful and universal tool for mathematical modelling in various areas of science and engineering. Researchers often choose this method when it is difficult to find a solution by other ways (or impossible at all, e.g. because of sophisticated analytical dependences, area of modelling or boundary conditions. Certainly, this necessarily statistical and flexible method requires significant computation time, but a continuously increasing computation capability makes it more and more attractive for a choice in specific situation.One of the promising areas to use the method of statistical modelling is description of light propagation in the turbid (scattering media. A high motivation for development of this approach is widely used lasers in biomedicine [3]. Besides, owing to its flexibility, the Monte-Carlo method is also of importance in theoretical researches, in particular, to estimate a degree of adequacy of the offered approximation methods for solving a radiative transfer equation [4].It is known that key parameters of turbid media are an absorption coefficient (characterizes absorption probability of a photon per unit of path length and a scattering coefficient (characterizes scattering probability of a photon per unit of path length. The ratio of each of the coefficients to their sum (extinction defines a probability of "death" or "survival" of a photon, respectively, in interaction with lenses. Generally, in the scattering medium there is a non-coherent radiation component, which in turbid media such as biological tissues, already at the insignificant depth becomes prevailing over the coherent one (residual of the incident laser beam [5].The author used the Monte-Carlo method to simulate optical radiation propagation in the multilayer biological tissues with their optical characteristics corresponding to the skin and subcutaneous tissues. Such a biological tissue is the absorbing

  13. A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi [Soonchunhyang Univ., Asan (Korea, Republic of)

    2016-10-15

    In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research.

  14. A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

    International Nuclear Information System (INIS)

    Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi

    2016-01-01

    In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research

  15. A novel detector based on dual-mode fiber polished half block's characteristics for sensitive monitorings of radiation and materials

    International Nuclear Information System (INIS)

    Saeed, Ghadirli

    2005-01-01

    Full text : The overlay index dependence characteristics of the power distribution between two modes of dual-mode fiber polished half blocks is studied. The heat dependence characteristics of a certain overlay index affects the modal power distributions at the input of interferometer sensors used for monitoring the sensitive heat radiation changes. The other fundamental applications such as material recognitions through the index dependence characteristics in the closed chambers is also suggested

  16. Influence of radiation on photo-electric characteristics of silicon photo cells with optical coverings

    International Nuclear Information System (INIS)

    Madatov, R.S.; Safarov, N.A.; Gasymova, V.G.; Abdurragimov, A.A.; Allahverdiev, A.M.

    2003-01-01

    In the given work results of measurements volt-ampere and spectral characteristics of silicon photo cells with optical coverings ZnS+Nd 2 O 3 irradiated accelerated electrons with energy 4.5 MeV are carried out. Elements have been made by diffusion of phosphorus in p-silicon with specific resistance 2 Ω·cm. Under condition of illumination from source AMI the photocurrent of short circuit made 40 mA/cm 2 , and a photo voltage of idling 0.52 V, efficiency made 15 %. To receive low reflection in wide area of spectral sensitivity and by that as much as possible to increase efficiency of elements with the help of two-layer coverings. The irradiation of samples was made on linear accelerator EL4-6 at room temperature. It is received, that with increase in a dose of an irradiation the Photocurrent and photo voltage decreases, and speed reduction of a photo-current is stronger, than photo voltage. The critical integrated stream for these elements makes 4·10 12 el/cm 2 . In all researched samples radiating reduction of a voltage of idling in an interval of 10 10 -10 14 el/cm 2 makes 8-10 %. The analysis of spectral characteristics of the irradiated samples show, that reduction of a photocurrent in long-wave areas of a spectrum is connected by creation of radiating defects in a base part of an element. The increase in a critical stream in silicon solar elements with optical a covering in comparison with elements without a covering is connected with low concentration of defects in the base, created with electron. Thus, on the basis of complex research of influence on radiating stability silicon solar elements us it is established, that two-layer coverings not only increases efficiency of photo cells, but also considerably raise value of an integrated stream electrons, that is equivalent to increase in service life of the elements working in conditions of radiation

  17. An Experimental Study on the Radiation Noise Characteristics of a Centrifugal Pump with Various Working Conditions

    Directory of Open Access Journals (Sweden)

    Chang Guo

    2017-12-01

    Full Text Available To investigate the radiation noise characteristics of a centrifugal pump under various working conditions, a noise measurement system is established; afterwards, the distribution of different points and intervals, as well as the overall level of noise, are studied. The total sound pressure level distribution for different points manifests the dipole and asymmetric directivity characteristics. Additionally, the acoustic energy is introduced to compare the noise of different intervals to reveal the asymmetric characteristics, and it is found that variation in working conditions has little impact on the acoustic energy distribution, and the ratio of the acoustic energy in the direction facing the tongue, as well as that in the direction against the tongue, to total acoustic energy fluctuate around 0.410 and 0.160, respectively, under various working conditions. Also, the A-weighted average sound pressure level (LpA is applied to describe the overall level of noise, and LpA increases gradually with the growth of rotational speed, but the growth slope decreases. While in the operation of throttling regulation, LpA shows the trend that first increases, then remains stable, and increases again with the growth of flow rate. This study could provide guidance for optimizing the operating conditions and noise control of centrifugal pumps.

  18. Radiation-induced biologic bystander effect elicited in vitro by targeted radiopharmaceuticals labeled with alpha-, beta-, and auger electron-emitting radionuclides.

    Science.gov (United States)

    Boyd, Marie; Ross, Susan C; Dorrens, Jennifer; Fullerton, Natasha E; Tan, Ker Wei; Zalutsky, Michael R; Mairs, Robert J

    2006-06-01

    Recent studies have shown that indirect effects of ionizing radiation may contribute significantly to the effectiveness of radiotherapy by sterilizing malignant cells that are not directly hit by the radiation. However, there have been few investigations of the importance of indirect effects in targeted radionuclide treatment. Our purpose was to compare the induction of bystander effects by external beam gamma-radiation with those resultant from exposure to 3 radiohaloanalogs of metaiodobenzylguanidine (MIBG): (131)I-MIBG (low-linear-energy-transfer [LET] beta-emitter), (123)I-MIBG (potentially high-LET Auger electron emitter), and meta-(211)At-astatobenzylguanidine ((211)At-MABG) (high-LET alpha-emitter). Two human tumor cell lines-UVW (glioma) and EJ138 (transitional cell carcinoma of bladder)-were transfected with the noradrenaline transporter (NAT) gene to enable active uptake of MIBG. Medium from cells that accumulated the radiopharmaceuticals or were treated with external beam radiation was transferred to cells that had not been exposed to radioactivity, and clonogenic survival was determined in donor and recipient cultures. Over the dose range 0-9 Gy of external beam radiation of donor cells, 2 Gy caused 30%-40% clonogenic cell kill in recipient cultures. This potency was maintained but not increased by higher dosage. In contrast, no corresponding saturation of bystander cell kill was observed after treatment with a range of activity concentrations of (131)I-MIBG, which resulted in up to 97% death of donor cells. Cellular uptake of (123)I-MIBG and (211)At-MABG induced increasing recipient cell kill up to levels that resulted in direct kill of 35%-70% of clonogens. Thereafter, the administration of higher activity concentrations of these high-LET emitters was inversely related to the kill of recipient cells. Over the range of activity concentrations examined, neither direct nor indirect kill was observed in cultures of cells not expressing the NAT and, thus

  19. The relationship of sick leave benefits, employment patterns, and individual characteristics to radiation therapy-related fatigue.

    Science.gov (United States)

    Poirier, Patricia

    2006-05-03

    To examine the relationship among sick leave benefits, employment patterns, individual characteristics, and fatigue in patients receiving radiation therapy. Prospective, longitudinal design. A community hospital radiation oncology department. 77 patients receiving radiation therapy to the breast, chest, head and neck, pelvis, or prostate. All were employed at the time of diagnosis. The Piper Integrated Fatigue Model guided the study. The Revised Piper Fatigue Scale (PFS), Brief Fatigue Inventory, and a single-item scale were used to measure five dimensions of subjective fatigue. Sick leave, employment, individual characteristics, and fatigue were measured at baseline, weekly during treatment, and at one month post-treatment. Employment patterns, availability of sick leave benefits, and fatigue. Mean total fatigue scores on the PFS ranged from 0-4.77 at baseline (mean = 0.46, SD = 0.93), 0-8.77 at the completion of treatment (mean = 2.84, SD = 2.40), and 0-4.82 at one month post-treatment (mean = 0.77, SD = 1.20). Side effects, education, living situation, age, treatment site, and work were associated with fatigue along the trajectory of radiation therapy. Study participants who were working at the end of radiation had lower fatigue scores than those who were not. Availability of sick leave benefits was associated with employment patterns during treatment. Work may have benefits during radiation therapy but may be affected by radiation therapy-related fatigue. Management of treatment side effects, including fatigue, may help patients remain in the workforce during radiation.

  20. The sensitivity of various thermoluminescent, photoluminescent and photographic detectors to neutrons emitted by a Pu-Be source

    International Nuclear Information System (INIS)

    Spurny, Frantisek; Marsault, Roger; Medioni, Roger; Portal, Guy.

    1975-07-01

    A series of experiments were conducted in order to determine the sensitivity of radiothermoluminescent detectors to fast neutrons. Experiments bearing on the determination of the sensitivity to neutrons emitted by a Pu-Be source are related here. The characteristics of the radiation field emitted by the source and especially of the γ-field are analysed as it is essential for the interpretation of results to know the latter, which appears to have been but partly studied so far. The measuring procedures are then described and a study is made of the best experimental procedures liable to eliminate or decrease the effect of external factors. The results are finally analysed [fr

  1. Numerical Analysis of Characteristics of Cellular Counterflow Diffusion Flames near Radiative Extinction Limit

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Su Ryong [Seoul National University of Technology, Seoul (Korea, Republic of)

    2014-06-15

    Nonlinear characteristics of cellular counterflow diffusion flame near the radiative extinction limit at large Damköhler number are numerically investigated. Lewis number is assumed to be 0.5 and flame evolution is calculated by imposing an infinitesimal disturbance to a one-dimensional(1-D) steady state flame. The early stage of nonlinear development is very similar to that predicted in a linear stability analysis. The disturbance with the wavenumber of the fastest growing mode emerges and grows gradually. Eventual, an alternating pattern of reacting and quenching stripes is developed. The cellular flame temperature is higher than that of 1-D flame because of the gain of the total enthalpy. As the Damköhler number is further increased, the shape of the cell becomes circular to increase the surface area per unit reacting volume. The cellular flames do not extinguish but survive even above the 1-D steady state extinction condition.

  2. Evaluation of dosimetric characteristics of graphene oxide/PVC nanocomposite for gamma radiation applications

    Energy Technology Data Exchange (ETDEWEB)

    Feizi, Shahzad; Malekie, Shahryar; Ziaie, Farhood [Nuclear Science and Technology Research Institute (NSTRI), Karaj (Iran, Islamic Republic of). Radiation Application Research School; Rahighi, Reza; Tayyebi, Ahmad [Univ. of Technology, Tehran (Iran, Islamic Republic of). Dept. of Physics

    2017-04-01

    Graphene oxide-polyvinyl chloride composite was prepared using tetrahydrofuran solvent-assisted dispersion of characterized nano flakes of graphene oxide in polymer matrix. Electrical percolation threshold of GO/PVC nanocomposite was determined via a finite element simulation method with a 2D model and compared with experimental results. A conductive cell with two silver coated walls was designed and fabricated for exploring dosimetric properties of the composite. Some characteristics of the new nanocomposite such as linearity of dose response, repeatability, sensitivity and angular dependence are investigated. According to 2D proposed method, obtained data associated to electrical conductivity of the GO/polymer composite for PVC matrix plotted in different GO weight percentages and had good compatibility (validity) with experimental data. The dose response is linear in the 17-51 mGy dose range and it can be introduced for gamma radiation dosimetry in diagnostic activities.

  3. Operating characteristics of radiation-hardened silicon pixel detectors for the CMS experiment

    CERN Document Server

    Hyosung, Cho

    2002-01-01

    The Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider (LHC) will have forward silicon pixel detectors as its innermost tracking device. The pixel devices will be exposed to the harsh radiation environment of the LHC. Prototype silicon pixel detectors have been designed to meet the specification of the CMS experiment. No guard ring is required on the n/sup +/ side, and guard rings on the p/sup +/ side are always kept active before and after type inversion. The whole n/sup +/ side is grounded and connected to readout chips, which greatly simplifies detector assembling and improves the stability of bump-bonded readout chips on the n/sup +/ side. Operating characteristics such as the leakage current, the full depletion voltage, and the potential distributions over guard rings were tested using standard techniques. The tests are discussed in this paper. (9 refs).

  4. Gamma-ray escape peak characteristics of radiation-damaged reverse-electrode germanium coaxial detectors

    International Nuclear Information System (INIS)

    Pehl, R.H.; Hull, E.L.; Madden, N.W.; Xing Jingshu; Friesel, D.L.

    1996-01-01

    A comparison of the characteristics of full-energy gamma-ray peaks and their corresponding escape peaks when high energy photons interact in radiation damaged reverse-electrode (n-type) germanium coaxial detectors is presented. Coaxial detector geometry is the dominant factor, causing charge collection to be dramatically better for interactions occurring near the outer periphery of the detector as well as increasing of the probability of escape events occurring in this region. It follows that the resolution of escape peaks is better than that of ordinary gamma-ray peaks. This is experimentally verified. A nearly identical but undamaged detector exhibited significant Doppler broadening of single escape peaks. Because double escape events preferentially occur at outer radii, energy shifts of double escape reflect extremely small amounts of charge trapping in undamaged detectors. (orig.)

  5. Review on the characteristics of radiation detectors for dosimetry and imaging

    International Nuclear Information System (INIS)

    Seco, Joao; Clasie, Ben; Partridge, Mike

    2014-01-01

    The enormous advances in the understanding of human anatomy, physiology and pathology in recent decades have led to ever-improving methods of disease prevention, diagnosis and treatment. Many of these achievements have been enabled, at least in part, by advances in ionizing radiation detectors. Radiology has been transformed by the implementation of multi-slice CT and digital x-ray imaging systems, with silver halide films now largely obsolete for many applications. Nuclear medicine has benefited from more sensitive, faster and higher-resolution detectors delivering ever-higher SPECT and PET image quality. PET/MR systems have been enabled by the development of gamma ray detectors that can operate in high magnetic fields. These huge advances in imaging have enabled equally impressive steps forward in radiotherapy delivery accuracy, with 4DCT, PET and MRI routinely used in treatment planning and online image guidance provided by cone-beam CT. The challenge of ensuring safe, accurate and precise delivery of highly complex radiation fields has also both driven and benefited from advances in radiation detectors. Detector systems have been developed for the measurement of electron, intensity-modulated and modulated arc x-ray, proton and ion beams, and around brachytherapy sources based on a very wide range of technologies. The types of measurement performed are equally wide, encompassing commissioning and quality assurance, reference dosimetry, in vivo dosimetry and personal and environmental monitoring. In this article, we briefly introduce the general physical characteristics and properties that are commonly used to describe the behaviour and performance of both discrete and imaging detectors. The physical principles of operation of calorimeters; ionization and charge detectors; semiconductor, luminescent, scintillating and chemical detectors; and radiochromic and radiographic films are then reviewed and their principle applications discussed. Finally, a general

  6. Effects on physicochemical, microbiological and sensory characteristics of honey bee samples submitted to gamma radiation

    International Nuclear Information System (INIS)

    Bera, Alexandre

    2010-01-01

    Honey production in Brazil has increased considerably and gaining pro eminence on the international market, as a result many demands have become part of the productive honey chain. In addition to the analyses provided for the Brazilian legislation, international market demand products that meet the most stringent quality standards. Honey has interesting characteristics due to its constitution, but even so there are problems that can change some how your identity and quality. The application of gamma radiation is a viable proposal which promotes the reduction of bio burden without changing the constitution and most importantly the physicochemical properties, with smaller nutritional losses when compared to other treatments used in foods. This study beyond the physicochemical parameters required by Brazilian regulation also included other relevant analyses, including FT-IR ATR. Microbiological analyses were carried out on samples of pure honeys and subsequently inoculated microbial known loads to assess the action of gamma radiation in doses of 5 and 10 kGy. The triangular test was used to differentiate the irradiated and not irradiated. samples The major changes that have occurred in samples of honeys were mainly in concentrations of HMF (hydroxymethylfurfural) and diastase activity occurring a significant decrease in all analyzed samples. There was a reduction microbiological from the application of the 5 kGy, reaching absence with 10 kGy dose except Paenibacillus larvae. The sensory analysis conducted on samples of honey and honey irradiated with 5, 10 and 15 kGy doses, pointed out that there is no significant difference (5%) between irradiated and control samples. The application of gamma radiation in honeys proved a very useful method in microbiological decontamination, featuring few changes in the product at doses up to 10 kGy. (author)

  7. Impact of Two Intense Dust Storms on Aerosol Characteristics and Radiative Forcing over Patiala, Northwestern India

    Directory of Open Access Journals (Sweden)

    Deepti Sharma

    2012-01-01

    Full Text Available Impact of dust storms on the aerosol characteristics and radiative forcing over Patiala, northwestern India has been studied during April-June of 2010 using satellite observations and ground-based measurements. Six dust events (DE have been identified during the study period with average values of Aqua-MODIS AOD550 and Microtops-II AOD500 over Patiala as 1.00±0.51 and 0.84±0.41, respectively while Aura-OMI AI exhibits high values ranging from 2.01 to 6.74. The Ångström coefficients α380–870 and β range from 0.12 to 0.31 and 0.95 to 1.40, respectively. The measured spectral AODs, the OPAC-derived aerosol properties and the surface albedo obtained from MODIS were used as main inputs in SBDART model for the calculation of aerosol radiative forcing (ARF over Patiala. The ARF at surface (SRF and top of atmosphere (TOA ranges from ∼−50 to −100 Wm−2 and from ∼−10 to −25 Wm−2, respectively during the maximum of dust storms. The radiative forcing efficiency was found to be −66 Wm−2AOD−1 at SRF and −14 Wm−2AOD−1 at TOA. High values of ARF in the atmosphere (ATM, ranging between ∼+40 Wm−2 and +80.0 Wm−2 during the DE days, might have significant effect on the warming of the lower and middle atmosphere and, hence, on climate over northwestern India.

  8. Experimental Investigation of Heat Transfer Characteristics of Automobile Radiator using TiO2-Nanofluid Coolant

    Science.gov (United States)

    Salamon, V.; Senthil kumar, D.; Thirumalini, S.

    2017-08-01

    The use of nanoparticle dispersed coolants in automobile radiators improves the heat transfer rate and facilitates overall reduction in size of the radiators. In this study, the heat transfer characteristics of water/propylene glycol based TiO2 nanofluid was analyzed experimentally and compared with pure water and water/propylene glycol mixture. Two different concentrations of nanofluids were prepared by adding 0.1 vol. % and 0.3 vol. % of TiO2 nanoparticles into water/propylene glycol mixture (70:30). The experiments were conducted by varying the coolant flow rate between 3 to 6 lit/min for various coolant temperatures (50°C, 60°C, 70°C, and 80°C) to understand the effect of coolant flow rate on heat transfer. The results showed that the Nusselt number of the nanofluid coolant increases with increase in flow rate. At low inlet coolant temperature the water/propylene glycol mixture showed higher heat transfer rate when compared with nanofluid coolant. However at higher operating temperature and higher coolant flow rate, 0.3 vol. % of TiO2 nanofluid enhances the heat transfer rate by 8.5% when compared to base fluids.

  9. Characteristics of X ray calibration fields for performance test of radiation measuring instruments

    International Nuclear Information System (INIS)

    Shimizu, Shigeru; Takahashi, Fumiaki; Sawahata, Tadahiro; Tohnami, Kohichi; Kikuchi, Hiroshi; Murayama, Takashi

    1999-02-01

    Performance test and calibration of the radiation measuring instruments for low energy photons are made using the X ray calibration fields which are monochromatically characterized by filtration of continuous X ray spectrum. The X ray calibration field needs to be characterized by some quality conditions such as quality index and homogeneity coefficient. The present report describes quality conditions, spectrum and some characteristics of X ray irradiation fields in the Facility of Radiation Standard of the Japan Atomic Energy Research Institute (FRS-JAERI). Fifty nine X ray qualities with the quality index of 0.6, 0.7, 0.8 and 0.9 were set for the tube voltages between 10 kV and 350 kV. Estimation of X ray spectrum measured with a Ge detector was made in terms of exposure, ambient dose equivalent and fluence for all the obtained qualities. Practical irradiation field was determined as the dose distribution uniformity is within ±3%. The obtained results improve the quality of X ray calibration fields and calibration accuracy. (author)

  10. Environmental gamma-ray dose measurements with thermoluminescence dosemeters (TLD) and environmental radiation characteristics

    International Nuclear Information System (INIS)

    Kanematsu, Seiko

    1999-01-01

    It is important to evaluate environmental gamma-ray exposure both at work and home in order to assess people's collective dosages. Environmental gamma radiation was measured for air-absorbed dose with a thermoluminescence dosemeter at various points in the workplace and Ningyotoge, and workplace radiation characteristics were analyzed. From the results, the public dose due to gamma rays generated artificially was assessed to be sufficiently lower than the annual limit. For indoor environments of the workplace, the maximum dosage rate among measured values was 97 nGy/h and the minimum value was 70 nGy/h, the average over one year was 83 nGy/h. The average annual outdoor dosage for a year was 82 nGy/ h. In Ningyotoge, the maximum was 103 nGy/h, minimum 60 nGy/h, and average 88 nGy/h. These values depend on the nature of the soil and weather factors, showing higher values in the summer than in the winter in the workplace. There was no significant difference in the dosage rate in houses and the workplace. (author)

  11. X-ray diffraction characteristics of curved monochromators for sychrotron radiation

    International Nuclear Information System (INIS)

    Boeuf, A.; Rustichelli, F.; Mazkedian, S.; Puliti, P.; Melone, S.

    1978-01-01

    A theoretical study is presented concerning the diffraction characteristics of curved monochromators for X-ray synchrotron radiation used at the laboratories of Hamburg, Orsay and Stanford. The investigation was performed by extending to the X-ray case a simple model recently developed and fruitfully employed to describe the neutron diffraction properties of curved monochromators. Several diffraction patterns were obtained corresponding to different monochromator materials (Ge, Si) used by the different laboratories, for different reflecting planes (111), (220), asymmetry angles, X-ray wave-lengths (Mo Kα, Cu Kα, Cr Kα) and curvature radii. The results are discussed in physical terms and their implications on the design of curved monochromators for synchrotron radiation are presented. In particular, the study shows that all the monochromators used in the different laboratories should behave practically as perfect crystals and therefore should have a very low integrated reflectivity corresponding to an optimized wavelength passband Δlambda/lambda approximately 10 -4 . The gain that can be obtained by increasing the curvature, by introducing a gradient in the lattice spacing or by any other kind of imperfection is quite limited and much lower than the desirable value. The adopted model can help in obtaining a possible moderate gain in intensity by also taking into consideration other parameters, such as crystal material, reflecting plane, asymmetry of the reflection and X-ray wavelength. (Auth.)

  12. Radiation characteristics and effective optical properties of dumbbell-shaped cyanobacterium Synechocystis sp

    International Nuclear Information System (INIS)

    Heng, Ri-Liang; Pilon, Laurent

    2016-01-01

    This study presents experimental measurements of the radiation characteristics of unicellular freshwater cyanobacterium Synechocystis sp. during their exponential growth in F medium. Their scattering phase function at 633 nm average spectral absorption and scattering cross-sections between 400 and 750 nm were measured. In addition, an inverse method was used for retrieving the spectral effective complex index of refraction of overlapping or touching bispheres and quadspheres from their absorption and scattering cross-sections. The inverse method combines a genetic algorithm and a forward model based on Lorenz–Mie theory, treating bispheres and quadspheres as projected area and volume-equivalent coated spheres. The inverse method was successfully validated with numerically predicted average absorption and scattering cross-sections of suspensions consisting of bispheres and quadspheres, with realistic size distributions, using the T-matrix method. It was able to retrieve the monomers' complex index of refraction with size parameter up to 11, relative refraction index less than 1.3, and absorption index less than 0.1. Then, the inverse method was applied to retrieve the effective spectral complex index of refraction of Synechocystis sp. approximated as randomly oriented aggregates consisting of two overlapping homogeneous spheres. Both the measured absorption cross-section and the retrieved absorption index featured peaks at 435 and 676 nm corresponding to chlorophyll a, a peak at 625 nm corresponding to phycocyanin, and a shoulder around 485 nm corresponding to carotenoids. These results can be used to optimize and control light transfer in photobioreactors. The inverse method and the equivalent coated sphere model could be applied to other optically soft particles of similar morphologies. - Highlights: • Radiation characteristics of Synechocystis sp. were measured during exponential growth. • This unicellular freshwater cyanobacterium features an interesting

  13. Radiative decay of surface plasmons on nonspherical silver particles

    International Nuclear Information System (INIS)

    Little, J.W.; Ferrell, T.L.; Callcott, T.A.; Arakawa, E.T.

    1982-01-01

    We have studied the radiation emitted by electron-bombarded silver particles. Electron micrographs have shown that the particles, obtained by heating thin (5 nm) silver films, were oblate (flattened) with minor axes aligned along the substrate normal. The characteristic wavelength obtained by bombarding these particles with 15-keV electrons was found to vary with angle of photon emission. We have modeled this wavelength shift as a result of the mixture of radiation from dipole and quadrupole surface-plasmon oscillations on oblate spheroids. Experimental observations of the energy, polarization, and angular distribution of the emitted radiation are in good agreement with theoretical calculations

  14. Top emitting white OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Freitag, Patricia; Luessem, Bjoern; Leo, Karl [Technische Universitaet Dresden, Institut fuer Angewandte Photophysik, George-Baehr-Strasse 1, 01069 Dresden (Germany)

    2009-07-01

    Top emitting organic light emitting diodes (TOLEDs) provide a number of interesting opportunities for new applications, such as the opportunity to fabricate ITO-free devices by using opaque substrates. This makes it possible to manufacture low cost OLEDs for signage and lighting applications. A general top emitting device consists of highly reflecting metal contacts as anode and semitransparent cathode, the latter one for better outcouling reasons. In between several organic materials are deposited as charge transporting, blocking, and emission layers. Here, we show a top emitting white organic light emitting diode with silver electrodes arranged in a p-i-n structure with p- and n-doped charge transport layers. The centrical emission layer consists of two phosphorescent (red and green) and one fluorescent (blue) emitter systems separated by an ambipolar interlayer to avoid mutual exciton quenching. By adding an additional dielectric capping layer on top of the device stack, we achieve a reduction of the strong microcavity effects which appear due to the high reflection of both metal electrodes. Therefore, the outcoupled light shows broad and nearly angle-independent emission spectra, which is essential for white light emitting diodes.

  15. Physicochemical and toxicological characteristics of particulate matter emitted from a non-road diesel engine: comparative evaluation of biodiesel-diesel and butanol-diesel blends.

    Science.gov (United States)

    Zhang, Zhi-Hui; Balasubramanian, Rajasekhar

    2014-01-15

    Combustion experiments were conducted to evaluate the effects of using blends of ultralow sulfur diesel (ULSD) with biodiesel or n-butanol on physicochemical and toxicological characteristics of particulate emissions from a non-road diesel engine. The results indicated that compared to ULSD, both the blended fuels could effectively reduce the particulate mass and elemental carbon emissions, with butanol being more effective than biodiesel. The proportion of organic carbon and volatile organic compounds in particles increased for both blended fuels. However, biodiesel blended fuels showed lower total particle-phase polycyclic aromatic hydrocarbons (PAHs) emissions. The total number emissions of particles ≤560nm in diameter decreased gradually for the butanol blended fuels, but increased significantly for the biodiesel blended fuels. Both the blended fuels indicated lower soot ignition temperature and activation energy. All the particle extracts showed a decline in cell viability with the increased dose. However, the change in cell viability among test fuels is not statistically significant different with the exception of DB-4 (biodiesel-diesel blend containing 4% oxygen) used at 75% engine load. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Age-dependent change in biological characteristics of stem cells in radiation-induced mammary carcinogenesis

    International Nuclear Information System (INIS)

    Shimada, Yoshiya; Nishimura, Mayumi; Kakinuma, Shizuko; Imaoka, Tatsuhiko; Yasukawa-Barnes, Jane; Gould, Michael N.; Clifton, Kelly H.

    2003-01-01

    If you ask what types of cells are the targets for carcinogenesis, a popular answer would be that cancer arises from stem cells. Stem cells are cells that are capable of both self-renewal and generation of differentiated progenies. If the hypothesis of 'cancer as stem cell disease' is correct, the risk of carcinogenesis should be a function of the number of stem cells and their responsiveness of carcinogen-induced damage. In the present study, we addressed the feasibility of this hypothesis using the rat mammary carcinogenesis model. One of the important conclusions emerging from studies on atomic bomb survivors concerns age-related changes in the susceptibility to breast cancer. The relative risk of breast cancer is very high among women exposed to ionizing radiation before or during puberty, and it decreases thereafter. Little information is available, however, on age-related changes in the radiobiological nature of mammary stem cells. We examined age-associated changes in the number of mammary stem-like cells (clonogens) and their susceptibility to radiation in terms of cell death and carcinogenic initiation frequency. The results were as follows. (1) During the prepubertal period, the total number of mammary clonogens per rat increased exponentially with a population doubling time of ∼4 days. After puberty, the doubling time lengthened to ∼30 days. The total number of clonogens in abdominal and inguinal mammary glands was ∼200 in 2-week-old rats, while it was ∼5600 in 8-week-old rats. (2) The survival curves of clonogenic cells after irradiation indicated that radiation sensitivity of the cells before and during puberty was much higher than after puberty. (3) The initiation frequency of the clonogens from prepubertal rats after 5 Gy irradiation was four times higher than that of the clonogens from post-pubertal rats. These results suggest that changes in the number of stem cells and their radiobiological characteristics underlie the age

  17. Age-dependent change in biological characteristics of stem cells in radiation-induced mammary carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Yoshiya; Nishimura, Mayumi; Kakinuma, Shizuko; Imaoka, Tatsuhiko [National Institute of Radiological Sciences, Anagawa, Chiba (Japan); Yasukawa-Barnes, Jane; Gould, Michael N.; Clifton, Kelly H. [Univ. of Wisconsin, Department of Human Oncology, Madison, WI (United States)

    2003-07-01

    If you ask what types of cells are the targets for carcinogenesis, a popular answer would be that cancer arises from stem cells. Stem cells are cells that are capable of both self-renewal and generation of differentiated progenies. If the hypothesis of 'cancer as stem cell disease' is correct, the risk of carcinogenesis should be a function of the number of stem cells and their responsiveness of carcinogen-induced damage. In the present study, we addressed the feasibility of this hypothesis using the rat mammary carcinogenesis model. One of the important conclusions emerging from studies on atomic bomb survivors concerns age-related changes in the susceptibility to breast cancer. The relative risk of breast cancer is very high among women exposed to ionizing radiation before or during puberty, and it decreases thereafter. Little information is available, however, on age-related changes in the radiobiological nature of mammary stem cells. We examined age-associated changes in the number of mammary stem-like cells (clonogens) and their susceptibility to radiation in terms of cell death and carcinogenic initiation frequency. The results were as follows. (1) During the prepubertal period, the total number of mammary clonogens per rat increased exponentially with a population doubling time of {approx}4 days. After puberty, the doubling time lengthened to {approx}30 days. The total number of clonogens in abdominal and inguinal mammary glands was {approx}200 in 2-week-old rats, while it was {approx}5600 in 8-week-old rats. (2) The survival curves of clonogenic cells after irradiation indicated that radiation sensitivity of the cells before and during puberty was much higher than after puberty. (3) The initiation frequency of the clonogens from prepubertal rats after 5 Gy irradiation was four times higher than that of the clonogens from post-pubertal rats. These results suggest that changes in the number of stem cells and their radiobiological characteristics

  18. Radiation

    International Nuclear Information System (INIS)

    2013-01-01

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

  19. Solar ultraviolet radiation: properties, characteristics and amounts observed in Brazil and South America.

    Science.gov (United States)

    Corrêa, Marcelo de Paula

    2015-01-01

    The beneficial and harmful effects of human exposure to solar ultraviolet radiation (UV-R) are topics that arouse great interest not only among physicians and scientists, but also the general public and the media. Currently, discussions on vitamin D synthesis (beneficial effect) are confronted with the high and growing number of new cases of non-melanoma skin cancer and other diseases of the skin and eyes (harmful effect) diagnosed each year in Brazil. However, the lack of scientific knowledge on the UV-R in Brazil and South America leads to adoption of protective measures based on studies conducted in Europe and USA, where the amounts of UV-R available at surface and the sun-exposure habits and characteristics of the population are significantly different from those observed in Brazil. In order to circumvent this problem, the Brazilian Society of Dermatology recently published the Brazilian Consensus of Photoprotection based on recent studies performed locally. The main goal of this article is to provide detailed educational information on the main properties and characteristics of UV-R and UV index in a simple language. It also provides: a) a summary of UV-R measurements recently performed in Brazil; b) a comparison with those performed in Europe; and, c) an evaluation to further clarify the assessment of potential harm and health effects owing to chronic exposures.

  20. Solar ultraviolet radiation: properties, characteristics and amounts observed in Brazil and South America*

    Science.gov (United States)

    Corrêa, Marcelo de Paula

    2015-01-01

    The beneficial and harmful effects of human exposure to solar ultraviolet radiation (UV-R) are topics that arouse great interest not only among physicians and scientists, but also the general public and the media. Currently, discussions on vitamin D synthesis (beneficial effect) are confronted with the high and growing number of new cases of non-melanoma skin cancer and other diseases of the skin and eyes (harmful effect) diagnosed each year in Brazil. However, the lack of scientific knowledge on the UV-R in Brazil and South America leads to adoption of protective measures based on studies conducted in Europe and USA, where the amounts of UV-R available at surface and the sun-exposure habits and characteristics of the population are significantly different from those observed in Brazil. In order to circumvent this problem, the Brazilian Society of Dermatology recently published the Brazilian Consensus of Photoprotection based on recent studies performed locally. The main goal of this article is to provide detailed educational information on the main properties and characteristics of UV-R and UV index in a simple language. It also provides: a) a summary of UV-R measurements recently performed in Brazil; b) a comparison with those performed in Europe; and, c) an evaluation to further clarify the assessment of potential harm and health effects owing to chronic exposures. PMID:26131858

  1. Thermal radiation characteristics and direct evidence of tungsten cooling on the way to nanostructure formation on its surface

    Energy Technology Data Exchange (ETDEWEB)

    Takamura, S., E-mail: takamura@aitech.ac.jp [Faculty of Engineering, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Miyamoto, T. [Faculty of Engineering, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Ohno, N. [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-07-15

    The physical properties of tungsten with nanostructure on its surface are investigated focusing on the thermal radiation and cooling characteristics. First, direct evidence of substantial W surface cooling has been clearly shown with use of a very thin thermocouple inserted into W target, which solves an uncertainty associated with a radiation thermometer. Second, the above measurements of W surface temperature make it possible to estimate quantitatively the total emissivity from which we may evaluate the radiative power through the Stefan–Boltzmann equation, which is very important for mitigation evaluation of a serious plasma heat load to the plasma-facing component.

  2. Thermal radiation characteristics and direct evidence of tungsten cooling on the way to nanostructure formation on its surface

    International Nuclear Information System (INIS)

    Takamura, S.; Miyamoto, T.; Ohno, N.

    2013-01-01

    The physical properties of tungsten with nanostructure on its surface are investigated focusing on the thermal radiation and cooling characteristics. First, direct evidence of substantial W surface cooling has been clearly shown with use of a very thin thermocouple inserted into W target, which solves an uncertainty associated with a radiation thermometer. Second, the above measurements of W surface temperature make it possible to estimate quantitatively the total emissivity from which we may evaluate the radiative power through the Stefan–Boltzmann equation, which is very important for mitigation evaluation of a serious plasma heat load to the plasma-facing component

  3. A DSM-based “2.0” System for Human Intervention Planning and Scheduling in Facilities Emitting Ionizing Radiations

    CERN Document Server

    Baudin, M; De Jonghe, J

    2012-01-01

    To efficiently and safely plan, schedule and control its interventions in underground facilities, which are subject to ionizing radiations, CERN is currently developing a collaborative Web-based system. A similar project for maintenance management is also under way. On top of presenting their key requirements, this paper shows how the implementation of DSM can enhance a so-called Web 2.0 or collaborative dimension by bringing an intuitive and fair way of taking the dependencies between several activities into account. It is also discussed that the incoherencies brought in DSM by collaborative use (for instance regarding the time intervals) can be addressed by enlarging the binary DSM span of dependencies to ones of the Allen’s interval algebra or at least a subset of its dependencies.

  4. Thermoluminescence analysis for detection of irradiated food - luminescence characteristics of minerals for different types of radiation and radiation doses

    International Nuclear Information System (INIS)

    Soika, C.; Delincée, H.

    2000-01-01

    Federal Research Centre for Nutrition, Institute of Nutritional Physiology, Haid-und-Neu-Straße 9, 76131 Karlsruhe (Germany) Thermoluminescence analysis is used to detect radiation processing of foods which are contaminated with sand or dust. Silicate minerals are isolated, their radiation-induced luminescence is measured and compared to the thermoluminescence from a second measurement after exposure to a dexned radiation dose (normalization). In the present study, the mineral mixture *sand+ and its main components feldspar and quartz were investigated for their thermoluminescence behaviour using different types of radiation, in order to determine adequate radiation sources for the purpose of normalization. The material was irradiated with types of ionizing radiation commonly used for commercial food irradiation, i.e. accelerated electrons with beam energies of 5 MeV as well as 10 MeV, and 60 Co--rays. After thermoluminescence measurements, samples were re-irradiated using either accelerated electrons with beam energies of 2 MeV, 5 MeV or 10 MeV, or 60 Co--rays, 90 Sr--rays or ultraviolet rays (200}280 nm). Evaluation of the xrst and corresponding second glow curve revealed that their shapes depend on the type of minerals in the mixture. The second radiation treatment (normalization) is satisfactory when accelerated electrons (2, 5 and 10 MeV) as well as 60 Co--rays and 90 Sr--rays are employed. Normalization with ultraviolet rays, however, has only a limited range of use

  5. General Purpose Fortran Program for Discrete-Ordinate-Method Radiative Transfer in Scattering and Emitting Layered Media: An Update of DISORT

    Science.gov (United States)

    Tsay, Si-Chee; Stamnes, Knut; Wiscombe, Warren; Laszlo, Istvan; Einaudi, Franco (Technical Monitor)

    2000-01-01

    This update reports a state-of-the-art discrete ordinate algorithm for monochromatic unpolarized radiative transfer in non-isothermal, vertically inhomogeneous, but horizontally homogeneous media. The physical processes included are Planckian thermal emission, scattering with arbitrary phase function, absorption, and surface bidirectional reflection. The system may be driven by parallel or isotropic diffuse radiation incident at the top boundary, as well as by internal thermal sources and thermal emission from the boundaries. Radiances, fluxes, and mean intensities are returned at user-specified angles and levels. DISORT has enjoyed considerable popularity in the atmospheric science and other communities since its introduction in 1988. Several new DISORT features are described in this update: intensity correction algorithms designed to compensate for the 8-M forward-peak scaling and obtain accurate intensities even in low orders of approximation; a more general surface bidirectional reflection option; and an exponential-linear approximation of the Planck function allowing more accurate solutions in the presence of large temperature gradients. DISORT has been designed to be an exemplar of good scientific software as well as a program of intrinsic utility. An extraordinary effort has been made to make it numerically well-conditioned, error-resistant, and user-friendly, and to take advantage of robust existing software tools. A thorough test suite is provided to verify the program both against published results, and for consistency where there are no published results. This careful attention to software design has been just as important in DISORT's popularity as its powerful algorithmic content.

  6. Effects of nuclear radiation on a high-reliability silicon power diode. 4: Analysis of reverse bias characteristics

    Science.gov (United States)

    Been, J. F.

    1973-01-01

    The effects of nuclear radiation on the reverse bias electrical characteristics of one hundred silicon power diodes were investigated. On a percentage basis, the changes in reverse currents were large but, due to very low initial values, this electrical characteristic was not the limiting factor in use of these diodes. These changes were interpreted in terms of decreasing minority carrier lifetimes as related to generation-recombination currents. The magnitudes of reverse voltage breakdown were unaffected by irradiation.

  7. Performance characteristics of a personal gamma spectrometer based on a SiPM array for radiation monitoring applications

    Science.gov (United States)

    Kefalidis, E.; Kandarakis, I.; David, S.

    2017-11-01

    Due to the increased radiation pollution in the environment as a result of the often nuclear accidents taking place around the world, the need for efficient, reliable, smart and handheld radiation measurement systems has been born especially in daily routine. In this study it is evaluated the angular response of two crystal non-pixelated Gd3Al2Ga3O12:Ce (GAGG:Ce) scintillators with dimensions at 10x10x10mm3 & 10x10x20mm3 under 137Cs isotope emitting at 662 keV coupled to a 4x4 discrete silicon photomultiplier array (SiPM). A symmetric resistive voltage division matrix was applied reducing the array 16 outputs to 4 analog position signals which digitized by a 4 Channel 12 bit 250 MS/s desktop waveform digitizer. The number of the evaluated angles set at 5 (0°, 45°, 90°, 135°, 180°) and a variety of measured values are presented (energy resolution, sensitivity, figure of merit etc). The encouraging results such as energy resolution about 9% and figure of merit equal to 4.11 for 10x10x10mm3 and 4.43 for 10x10x20mm3 crystal, prove that this system could build up to a compact radiation sensor for integration into mobile applications.

  8. Characteristics and direct radiative effect of mid-latitude continental aerosols: the ARM case

    Directory of Open Access Journals (Sweden)

    M. G. Iziomon

    2003-01-01

    Full Text Available A multi-year field measurement analysis of the characteristics and direct radiative effect of aerosols at the Southern Great Plains (SGP central facility of the Atmospheric Radiation Measurement (ARM Program is presented. Inter-annual mean and standard deviation of submicrometer scattering fraction (at 550 nm and Ångström exponent å (450 nm, 700 nm at the mid-latitude continental site are indicative of the scattering dominance of fine mode aerosol particles, being 0.84±0.03 and 2.25±0.09, respectively. We attribute the diurnal variation of submicron aerosol concentration to coagulation, photochemistry and the evolution of the boundary layer. Precipitation does not seem to play a role in the observed afternoon maximum in aerosol concentration. Submicron aerosol mass at the site peaks in the summer (12.1±6.7mg m-3, with the summer value being twice that in the winter. Of the chemically analyzed ionic components (which exclude carbonaceous aerosols, SO4= and NH4+ constitute the dominant species at the SGP seasonally, contributing 23-30% and 9-12% of the submicron aerosol mass, respectively. Although a minor species, there is a notable rise in NO3- mass fraction in winter. We contrast the optical properties of dust and smoke haze. The single scattering albedo w0 shows the most remarkable distinction between the two aerosol constituents. We also present aircraft measurements of vertical profiles of aerosol optical properties at the site. Annually, the lowest 1.2 km contributes 70% to the column total light scattering coefficient. Column-averaged and surface annual mean values of hemispheric backscatter fraction (at 550 nm, w0 (at 550 nm and å (450 nm, 700 nm agree to within 5% in 2001. Aerosols produce a net cooling (most pronounced in the spring at the ARM site

  9. Scattering and absorption characteristics of aerosols at an urban megacity over IGB: Implications to radiative forcing

    Science.gov (United States)

    Srivastava, A. K.; Bisht, D. S.; Singh, Sachchidanand; Kishore, N.; Soni, V. K.; Singh, Siddhartha; Tiwari, S.

    2018-06-01

    Aerosol scattering and absorption characteristics were investigated at an urban megacity Delhi in the western Indo-Gangetic Basin (IGB) during the period from October 2011 to September 2012 using different in-situ measurements. The scattering coefficient (σsp at 550 nm) varied between 71 and 3014 Mm-1 (mean 710 ± 615 Mm-1) during the entire study period, which was about ten times higher than the absorption coefficient (σabs at 550 nm 67 ± 40 Mm-1). Seasonally, σsp and σabs were substantially higher during the winter/post-monsoon periods, which also gave rise to single scattering albedo (SSA) by 5%. The magnitude of SSA (at 550 nm) varied between 0.81 and 0.94 (mean: 0.89 ± 0.05). Further, the magnitude of scattering Ångström exponent (SAE) and back-scattering Ångström exponent (BAE) showed a wide range from -1.20 to 1.57 and -1.13 to 0.87, respectively which suggests large variability in aerosol sizes and emission sources. Relatively higher aerosol backscatter fraction (b at 550 nm) during the monsoon (0.25 ± 0.10) suggests more inhomogeneous scattering, associated with the coarser dust particles. However, lower value of b during winter (0.13 ± 0.02) is associated with more isotropic scattering due to dominance of smaller size particles. This is further confirmed with the estimated asymmetry parameter (AP at 550 nm), which exhibits opposite trend with b. The aerosol optical parameters were used in a radiative transfer model to estimate aerosol radiative forcing. A mean radiative forcing of -61 ± 22 W m-2 (ranging from -111 to -40 W m-2) was observed at the surface and 42 ± 24 W m-2 (ranging from 18 to 87 W m-2) into the atmosphere, which can give rise to the mean atmospheric heating rate of 1.18 K day-1.

  10. Ionizing radiation effect on physico-mechanical characteristics of thermoplastic polymer materials

    International Nuclear Information System (INIS)

    Stankevich, V.M.; Pleskachevsky, Yu.M.; Smirnov, V.V.

    2001-01-01

    Investigation results in the field of ionizing radiation effect on structure and physico-mechanical properties of novel polymer materials are presented. The materials under study are various grades of PETP, PA-6 and polyethylene concentrate of technical carbon (PECC) commercially produced and extensively used in Belarus and abroad. It has been proved using EPR, thermomechanical and gel analyses that a combined effect of ionizing radiation within 0 to 10 MGy of absorbed dose range under different concentrations of mineral fillers (TiO 2 , kaolin, carbon black, graphite) and intensive cross-linking processes in amorphous phase are able to considerably improve strength characteristics of the studied polymers and their compositions. Most informative parameter was found to be breaking strength at rapture (σ r ) which enables to estimate the character of ionizing effect on the targets. At 0.01-0.05 MGy absorbed dose the highest σ r was shown as compared to initial PETP by the following materials: PN grade - 9 times, D - two and a half. When absorbed dose of PETP reached 0.2 MGy, σ r of PN surpassed the initial material 7.8 times, that of D - by 30% and E - by 1,5%. This is the evidence of elevated resistance of named materials to ionizing radiation in contrast to non-filled PETP 215. Growth of σ r in PA-6 has been noticed at absorbed dose above 2 MGy in response to maximum gel-formation values. Abrupt reduction of the studied parameters of PP upon irradiation is attributed to its destruction. Domination of cross-linking processes has been observed in PEVP and PECC which reduces macromolecular mobility and elasticity of the material as a whole but promotes polymer strengthening. Drop of PEVP impact strength can be related to its embrittlement. Presence of the filler (carbon black) in PECC at the initial stage of exposure resulted in improvement of studied parameters. Their further impairment is the result of limited mobility of macromolecules owing to cross-linking in

  11. Determining optical and radiation characteristics of cathode ray tubes' glass to be reused as radiation shielding glass

    International Nuclear Information System (INIS)

    Zughbi, A.; Kharita, M.H.; Shehada, A.M.

    2017-01-01

    A new method of recycling glass of Cathode Ray Tubes (CRTs) has been presented in this paper. The glass from CRTs suggested being used as raw materials for the production of radiation shielding glass. Cathode ray tubes glass contains considerable amounts of environmentally hazardous toxic wastes, namely heavy metal oxides such as lead oxide (PbO). This method makes CRTs glass a favorable choice to be used as raw material for Radiation Shielding Glass and concrete. The heavy metal oxides increase its density, which make this type of glass nearly equivalent to commercially available shielding glass. CRTs glass have been characterized to determine heavy oxides content, density, refractive index, and radiation shielding properties for different Gamma-Ray energies. Empirical methods have been used by using the Gamma-Ray source cobalt-60 and computational method by using the code XCOM. Measured and calculated values were in a good compatibility. The effects of irradiation by gamma rays of cobalt-60 on the optical transparency for each part of the CRTs glass have been studied. The Results had shown that some parts of CRTs glass have more resistant to Gamma radiation than others. The study had shown that the glass of cathode ray tubes could be recycled to be used as radiation shielding glass. This proposed use of CRT glass is only limited to the available quantity of CRT world-wide. - Highlights: • A new method of recycling glass of Cathode Ray Tubes (CRTs) has been presented. • The glass from CRTs used as raw materials for radiation shielding glass. • The resulted glass have good optical properties and stability against radiations.

  12. Atmospheric emitted radiance interferometer (AERI): Status and the aerosol explanation for extra window region emissions

    Energy Technology Data Exchange (ETDEWEB)

    Revercomb, H.E.; Knuteson, R.O.; Best, F.A.; Dirkx, T.P. [Univ. of Wisconsin, Madison, WI (United States)] [and others

    1996-04-01

    High spectral resolution observations of downwelling emission from 3 to 19 microns have been made by the Atmospheric Emitted Radiance Interferometer (AERI) Prototype at the Southern Great Plains (SGP) Cloud and Radiative Testbed (CART) site for over two years. The spectral data set from AERI provides a basis for improving clear sky radiative transfer; determining the radiative impact of clouds, including the derivation of cloud radiative properties; defining the influences of aerosols in the window regions; and retrieving boundary layer state properties, including temperature, water vapor, and other trace gases. The data stream of radiometrically and spectrally calibrated radiances is routinely provided by Pacific Northwest Laboratory (PNL) to those science teams requesting it, and further information on the instrument and data characteristics is available in the ARM Science Team proceedings for 1993 and 1994 and in several conference publications. This paper describes the AERI status, calibration, field experiment wit a new AERI-01 and schedule, window region emissions, and future AERI plans.

  13. Transition undulator radiation as bright infrared sources

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.J. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/{gamma}, where {gamma} is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron`s longitudinal velocity as it enters and leaves the undulator. The characteristic of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets.

  14. Determining optical and radiation characteristics of cathode ray tubes' glass to be reused as radiation shielding glass

    Science.gov (United States)

    Zughbi, A.; Kharita, M. H.; Shehada, A. M.

    2017-07-01

    A new method of recycling glass of Cathode Ray Tubes (CRTs) has been presented in this paper. The glass from CRTs suggested being used as raw materials for the production of radiation shielding glass. Cathode ray tubes glass contains considerable amounts of environmentally hazardous toxic wastes, namely heavy metal oxides such as lead oxide (PbO). This method makes CRTs glass a favorable choice to be used as raw material for Radiation Shielding Glass and concrete. The heavy metal oxides increase its density, which make this type of glass nearly equivalent to commercially available shielding glass. CRTs glass have been characterized to determine heavy oxides content, density, refractive index, and radiation shielding properties for different Gamma-Ray energies. Empirical methods have been used by using the Gamma-Ray source cobalt-60 and computational method by using the code XCOM. Measured and calculated values were in a good compatibility. The effects of irradiation by gamma rays of cobalt-60 on the optical transparency for each part of the CRTs glass have been studied. The Results had shown that some parts of CRTs glass have more resistant to Gamma radiation than others. The study had shown that the glass of cathode ray tubes could be recycled to be used as radiation shielding glass. This proposed use of CRT glass is only limited to the available quantity of CRT world-wide.

  15. Luminescence characteristics of Sr{sub 1-x}Ba{sub x}Si{sub 2}O{sub 2}N{sub 2}:Eu{sup 2+} phosphors for white light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Anoop, G.; Cho, I.H.; Suh, D.W.; Yoo, J.S. [Display Materials Laboratory, School of Chemical Engineering and Materials Science, Chung-Ang University, Heukseok-Dong 221, Dongjak-gu, Seoul 156-756 (Korea, Republic of)

    2012-12-15

    Sr{sub 1-x}Ba{sub x}Si{sub 2}O{sub 2}N{sub 2}:Eu{sup 2+} phosphors were synthesized using high temperature solid state reaction. The effect of Ba incorporation on the structural and luminescence characteristics of SrSi{sub 2}O{sub 2}N{sub 2}:Eu{sup 2+} phosphors were studied. The phosphors were crystallized in triclinic crystal structure and the cell volume increases monotonically with Ba addition. The PL emission peak wavelength red shifts with Ba up to x = 0.50 beyond which no red shift is observed. The XPS analysis shows that nitrogen is being incorporated into the host lattice along with Ba addition up to x = 0.50. The as synthesized phosphors show high thermal stability. Phosphor converted light emitting diodes were realized using Sr{sub 1-x}Ba{sub x}Si{sub 2}O{sub 2}N{sub 2}:Eu{sup 2+} phosphors (x = 0 and x = 0.40) showing luminance efficacies of 108 and 101 lm W{sup -1}. The CIE chromaticity coordinates of Sr{sub 1-x}Ba{sub x}Si{sub 2}O{sub 2}N{sub 2}:Eu (x = 0 and x = 0.40) phosphors. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Study of Radiative Forcing of Dust Aerosols and its impact on Climate Characteristics

    KAUST Repository

    Qureshi, Fawwad H

    2012-01-01

    The purpose of following project is to study the effect of dust aerosols on the radiative forcing which is directly related to the surface temperature. A single column radiative convective model is used for simulation purpose. A series

  17. 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...

  18. Visible optical radiation generates bactericidal effect applicable for inactivation of health care associated germs demonstrated by inactivation of E. coli and B. subtilis using 405-nm and 460-nm light emitting diodes

    Science.gov (United States)

    Hönes, Katharina; Stangl, Felix; Sift, Michael; Hessling, Martin

    2015-07-01

    The Ulm University of Applied Sciences is investigating a technique using visible optical radiation (405 nm and 460 nm) to inactivate health-hazardous bacteria in water. A conceivable application could be point-of-use disinfection implementations in developing countries for safe drinking water supply. Another possible application field could be to provide sterile water in medical institutions like hospitals or dental surgeries where contaminated pipework or long-term disuse often results in higher germ concentrations. Optical radiation for disinfection is presently mostly used in UV wavelength ranges but the possibility of bacterial inactivation with visible light was so far generally disregarded. One of the advantages of visible light is, that instead of mercury arc lamps, light emitting diodes could be used, which are commercially available and therefore cost-efficient concerning the visible light spectrum. Furthermore they inherit a considerable longer life span than UV-C LEDs and are non-hazardous in contrast to mercury arc lamps. Above all there are specific germs, like Bacillus subtilis, which show an inactivation resistance to UV-C wavelengths. Due to the totally different deactivation mechanism even higher disinfection rates are reached, compared to Escherichia coli as a standard laboratory germ. By 460 nm a reduction of three log-levels appeared with Bacillus subtilis and a half log-level with Escherichia coli both at a dose of about 300 J/cm². By the more efficient wavelength of 405 nm four and a half log-levels are reached with Bacillus subtilis and one and a half log-level with Escherichia coli also both at a dose of about 300 J/cm². In addition the employed optical setup, which delivered a homogeneous illumination and skirts the need of a stirring technique to compensate irregularities, was an important improvement compared to previous published setups. Evaluated by optical simulation in ZEMAX® the designed optical element provided proven

  19. INFLUENCE OF ULTRAVIOLET RADIATION ON MICROBIOLOGICAL AND SENSORY CHARACTERISTICS OF CERTAIN CATEGORIES OF VEGETABLES PRODUCTS AND THEIR PRESERVATION LIFE

    Directory of Open Access Journals (Sweden)

    Danilevici Constantin

    2010-01-01

    Full Text Available Research paper aims to highlight the scientific correlation between the influence of ultraviolet radiation (UV onsensory and microbiological characteristics of plant products in the category of leaves (lettuce and other types ofvegetables or fruit (bananas and their preservation’s duration, through their UV irradiation under certain conditions.The literature indicates a germicidal action of UV (medium UV on micro-organisms, optimal for λ = 254 nm. Theeffectiveness of radiation is influenced by duration of irradiation, the distance between the radiation source and thesample product and radiant power source.The action of microbial cell inactivation or destruction can be explained by changes in cellular structure andpermeability with changes at the level of mitochondria and the genetic material as a result of photochemical effects ofUV products. Research highlights the preservative effect of UV radiation (with λ = 254 nm and also their influence onsensory properties and positive to negative for leafy vegetables and fruits (bananas in our case.

  20. Effect of Radiation processing on sensory and chemical characteristics of broad beans (Giza,2)(Vicia Faba)

    International Nuclear Information System (INIS)

    Mahmoud, A.A.; El-Niely, F.G.

    2002-01-01

    Broad bean is the important leguminous protein consumed in egypt as a source of protein diet. The most popular way of preparing beans is the stewd form (Fool Medames). However, great losses due to insect infestation occur during storage. To combat these losses radiation processing has been used as an effective alternative of chemical fumigants to combat insect pets. The beans were irradiated at 25.5, 10 and kgy. The effects of treatments were investigated on sensory and chemical characteristics and on the solubility of broad beans protein, the amino acids content and on the nutritive value of bean protein from the view of its amino acids profile. The results of study indicate that the sensory evaluation of sewed irradiated 2.5 and 5 kGy samples revealed no significantdiffference in hardness, gumminess and acceptability. moreover, no significant changes in adhesivess, between samples irradiated at 5, 10 and 20 KGy, irradiation up to 20 KGy was found to improve the hardness of stewed broad bean which would improve the quality of broad of bean

  1. MR imaging characteristics of osteoradionecrosis of the pelvis after radiation therapy on gynecological tumors

    International Nuclear Information System (INIS)

    Schmitt, J.; Abolmaali, N.D.; Jacobi, V.; Vogl, T.J.; Hoeller, U.; Schiemann, M.; Obert, K.

    2002-01-01

    Purpose: To describe MR imaging characteristics of osteoradionecrosis (ORN) of the pelvis as a result of radiation therapy (RT) on gynecological tumors. Material and Methods: Radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed on 9 women (mean age 67.5 years) with gynecological tumors to identify ORN. T 1 - and T 2 -weighted sequences and contrast-enhanced t 1 -weighted sequences with and without fat saturation were used. The patients began developing pain after the completion of RT indicating a possible ORN a which time MRI was performed. MR images were correlated with the results of clinical examinations. Results: Depending on the time elapsed after RT, ORN presented with different signal intensities. The acquired images suggested that signal changes in T 2 -weighted images as well as the different enhancement behaviour of ORN could be dependent on the time elapsed after RT. Visualisation of the affected regions was best achieved with fat-saturated T 1 -weighted sequences. CT showed increased density in the affected regions corresponding to osteosclerosis. In all cases the sacroiliac joint was affected, some times bilateraly. Conclusion: MRI is helpful in detecting and characterizing ORN. Changes in signal intensity, based on histopathological tissue changes could make a chronological classification possible. (orig.) [de

  2. AN EVALUATION OF THE BASIC CHARACTERISTICS OF A PLASTIC SCINTILLATING FIBRE DETECTOR IN CT RADIATION FIELDS.

    Science.gov (United States)

    Terasaki, Kento; Fujibuchi, Toshioh; Toyoda, Takatoshi; Yoshida, Yutaka; Akasaka, Tsutomu; Nohtomi, Akihiro; Morishita, Junji

    2016-12-01

    The ionisation chamber for computed tomography (CT) is an instrument that is most commonly used to measure the computed tomography dose index. However, it has been reported that the 10 cm effective detection length of the ionisation chamber is insufficient due to the extent of the dose distribution outside the chamber. The purpose of this study was to estimate the basic characteristics of a plastic scintillating fibre (PSF) detector with a long detection length of 50 cm in CT radiation fields. The authors investigated position dependence using diagnostic X-ray equipment and dependencies for energy, dose rate and slice thickness using an X-ray CT system. The PSF detector outputs piled up at a count rate of 10 000 counts ms -1 in dose rate dependence study. With calibration, this detector may be useful as a CT dosemeter with a long detection length except for the measurement at high dose rate. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Proximity effect on patterning characteristics of hole patterns in synchrotron radiation lithography

    International Nuclear Information System (INIS)

    Somemura, Yoh; Deguchi, Kimiyoshi; Miyoshi, Kazunori

    1994-01-01

    This paper reports the results of analyzing the proximity effect on the patterning characteristics for plural neighboring hole patterns in synchrotron radiation lithography. Fresnel diffraction simulation was used and pattern replication experiments were performed with pattern pitch, proximity gap, and mask contrast as parameters. Even when the pattern pitch (hole:space) is 1:1, pattern sizes down to 0.2 μm can be replicated with a large dose margin under a large proximity gap condition up to 40 μm, irrespective of the mask contrast. A low-contrast (2.5) mask has an advantage over the conventional-contrast (7) mask in that it allows the use of a larger proximity gap when replicating hole patterns with a size of 0.1-0.2 μm. Moreover, the phase-shifting mask we previously proposed improves the exposure latitude and widens the proximity gap, so that it is possible to use a 20-μm gap to replicate 0.1-μm hole patterns for a pitch of 1:1 and to use a 30-μm gap for a pitch of 1:2. (author)

  4. Determination of Atmospheric Aerosol Characteristics from the Polarization of Scattered Radiation

    Science.gov (United States)

    Harris, F. S., Jr.; McCormick, M. P.

    1973-01-01

    Aerosols affect the polarization of radiation in scattering, hence measured polarization can be used to infer the nature of the particles. Size distribution, particle shape, real and absorption parts of the complex refractive index affect the scattering. From Lorenz-Mie calculations of the 4-Stokes parameters as a function of scattering angle for various wavelengths the following polarization parameters were plotted: total intensity, intensity of polarization in plane of observation, intensity perpendicular to the plane of observation, polarization ratio, polarization (using all 4-Stokes parameters), plane of the polarization ellipse and its ellipticity. A six-component log-Gaussian size distribution model was used to study the effects of the nature of the polarization due to variations in the size distribution and complex refractive index. Though a rigorous inversion from measurements of scattering to detailed specification of aerosol characteristics is not possible, considerable information about the nature of the aerosols can be obtained. Only single scattering from aerosols was used in this paper. Also, the background due to Rayleigh gas scattering, the reduction of effects as a result of multiple scattering and polarization effects of possible ground background (airborne platforms) were not included.

  5. Numerical research of dynamic characteristics in tower solar cavity receiver based on step-change radiation flux

    Science.gov (United States)

    Chen, Zhengwei; Wang, Yueshe; Hao, Yun; Wang, Qizhi

    2013-07-01

    The solar cavity receiver is an important light-energy to thermal-energy convector in the tower solar thermal power plant system. The heat flux in the inner surface of the cavity will show the characteristics of non-continuous step change especially in non-normal and transient weather conditions, which may result in a continuous dynamic variation of the characteristic parameters. Therefore, the research of dynamic characteristics of the receiver plays a very important role in the operation and the control safely in solar cavity receiver system. In this paper, based on the non-continuous step change of radiation flux, a non-linear dynamic model is put forward to obtain the effects of the non-continuous step change radiation flux and step change feed water flow on the receiver performance by sequential modular approach. The subject investigated in our study is a 1MW solar power station constructed in Yanqing County, Beijing. This study has obtained the dynamic responses of the characteristic parameters in the cavity receiver, such as drum pressure, drum water level, main steam flow and main steam enthalpy under step change radiation flux. And the influence law of step-change feed water flow to the dynamic characteristics in the receiver also has been analyzed. The results have a reference value for the safe operation and the control in solar cavity receiver system.

  6. Vibration analysis and sound field characteristics of a tubular ultrasonic radiator.

    Science.gov (United States)

    Liang, Zhaofeng; Zhou, Guangping; Zhang, Yihui; Li, Zhengzhong; Lin, Shuyu

    2006-12-01

    A sort of tubular ultrasonic radiator used in ultrasonic liquid processing is studied. The frequency equation of the tubular radiator is derived, and its radiated sound field in cylindrical reactor is calculated using finite element method and recorded by means of aluminum foil erosion. The results indicate that sound field of tubular ultrasonic radiator in cylindrical reactor appears standing waves along both its radial direction and axial direction, and amplitudes of standing waves decrease gradually along its radial direction, and the numbers of standing waves along its axial direction are equal to the axial wave numbers of tubular radiator. The experimental results are in good agreement with calculated results.

  7. Light-Emitting Pickles

    Science.gov (United States)

    Vollmer, M.; Mollmann, K-P.

    2015-01-01

    We present experiments giving new insights into the classical light-emitting pickle experiment. In particular, measurements of the spectra and temperatures, as well as high-speed recordings, reveal that light emission is connected to the polarity of the electrodes and the presence of hydrogen.

  8. Numerical study of radiation effect on the municipal solid waste combustion characteristics inside an incinerator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingfu, E-mail: jfwang@bjut.edu.cn; Xue, Yanqing; Zhang, Xinxin; Shu, Xinran

    2015-10-15

    Highlights: • A 3-D model for the MSW incinerator with preheated air was developed. • Gas radiative properties were obtained from a statistical narrow-band model. • Non-gray body radiation model can provide more accurate simulation results. - Abstract: Due to its advantages of high degree volume reduction, relatively stable residue, and energy reclamation, incineration becomes one of the best choices for Municipal Solid Waste (MSW) disposal. However, detailed measurements of temperature and gas species inside a furnace are difficulty by conventional experimental techniques. Therefore, numerical simulation of MSW incineration in the packed bed and gas flow field was applied. In this work, a three dimensional (3-D) model of incinerator system, including flow, heat transfer, detailed chemical mechanisms, and non-gray gas models, was developed. Radiation from the furnace wall and the flame formed above the bed is of importance for drying and igniting the waste. The preheated air with high temperature is used for the MSW combustion. Under the conditions of high temperature and high pressure, MSW combustion produces a variety of radiating gases. The wavelength-depend radiative properties of flame adopted in non-gray radiation model were obtained from a statistical narrow-band model. The influence of radiative heat transfer on temperature, flow field is researched by adiabatic model (without considering radiation), gray radiation model, and non-gray radiation model. The simulation results show that taking into account the non-gray radiation is essential.

  9. Characteristic of the radiation field in low earth orbit and in deep space

    International Nuclear Information System (INIS)

    Reitz, Guenther

    2008-01-01

    The radiation exposure in space by cosmic radiation can be reduced through careful mission planning and constructive measures as example the provision of a radiation shelter, but it cannot be completely avoided. The reason for that are the extreme high energies of particles in this field and the herewith connected high penetration depth in matter. For missions outside the magnetosphere ionizing radiation is recognized as the key factor through its impact on crew health and performance. In absence of sporadic solar particle events the radiation exposure in Low Earth orbit (LEO) inside Spacecraft is determined by the galactic cosmic radiation (protons and heavier ions) and by the protons inside the South Atlantic Anomaly (SAA), an area where the radiation belt comes closer to the earth surface due to a displacement of the magnetic dipole axes from the Earth's center. In addition there is an albedo source of neutrons produced as interaction products of the primary galactic particles with the atoms of the earth atmosphere. Outside the spacecraft the dose is dominated by the electrons of the horns of the radiation belt located at about 60 latitude in Polar Regions. The radiation field has spatial and temporal variations in dependence of the Earth magnetic field and the solar cycle. The complexity of the radiation field inside a spacecraft is further increased through the interaction of the high energy components with the spacecraft shielding material and with the body of the astronauts. In interplanetary missions the radiation belt will be crossed in a couple of minutes and therefore its contribution to their radiation exposure is quite small, but subsequently the protection by the Earth magnetic field is lost, leaving only shielding measures as exposure reduction means. The report intends to describe the radiation field in space, the interaction of the particles with the magnetic field and shielding material and give some numbers on the radiation exposure in low earth

  10. Characteristic of the radiation field in low Earth orbit and in deep space.

    Science.gov (United States)

    Reitz, Guenther

    2008-01-01

    The radiation exposure in space by cosmic radiation can be reduced through careful mission planning and constructive measures as example the provision of a radiation shelter, but it cannot be completely avoided. The reason for that are the extreme high energies of particles in this field and the herewith connected high penetration depth in matter. For missions outside the magnetosphere ionizing radiation is recognized as the key factor through its impact on crew health and performance. In absence of sporadic solar particle events the radiation exposure in Low Earth orbit (LEO) inside Spacecraft is determined by the galactic cosmic radiation (protons and heavier ions) and by the protons inside the South Atlantic Anomaly (SAA), an area where the radiation belt comes closer to the earth surface due to a displacement of the magnetic dipole axes from the Earth's center. In addition there is an albedo source of neutrons produced as interaction products of the primary galactic particles with the atoms of the earth atmosphere. Outside the spacecraft the dose is dominated by the electrons of the horns of the radiation belt located at about 60" latitude in Polar Regions. The radiation field has spatial and temporal variations in dependence of the Earth magnetic field and the solar cycle. The complexity of the radiation field inside a spacecraft is further increased through the interaction of the high energy components with the spacecraft shielding material and with the body of the astronauts. In interplanetary missions the radiation belt will be crossed in a couple of minutes and therefore its contribution to their radiation exposure is quite small, but subsequently the protection by the Earth magnetic field is lost, leaving only shielding measures as exposure reduction means. The report intends to describe the radiation field in space, the interaction of the particles with the magnetic field and shielding material and give some numbers on the radiation exposure in low earth

  11. Investigating the effect of K-characteristic radiation on the performance of nuclear medicine scintillators by Monte Carlo methods

    International Nuclear Information System (INIS)

    Liaparinos, Panagiotis; Kandarakis, Ioannis; Cavouras, Dionisis; Delis, Harry; Panayiotakis, George

    2006-01-01

    The aim of this study was to evaluate the effect of K-characteristic radiation on the performance of scintillator crystals incorporated in nuclear medicine detectors (LSO, BGO, GSO). K-characteristic radiation is produced within materials of at least one high atomic number element (e.g. Lu, Gd, Bi). This radiation may either be reabsorbed or it may escape the scintillator. In both cases the light emission efficiency of the scintillator may be affected resulting in either spatial or energy resolution degradation. A computational program, based on Monte Carlo methods, was developed in order to simulate the transport of K-characteristic radiation within the most commonly used scintillator materials. Crystal thickness was allowed to vary from 0.5 up to 15 mm. A monoenergetic pencil beam, with energy varying from 0.60 to 0.511 MeV was considered to fall on the center of the crystal surface. The dominant γ-ray interactions (elastic and inelastic scattering and photoelectric absorption) were taken into account in the simulation. Results showed that, depending on crystal thickness, incident photon energy and scintillator's intrinsic properties (L or K-fluorescence yield, effective atomic number and density), the scintillator's emission efficiency may be significantly reduced and affect spatial or energy resolution

  12. Gamma radiation effects on some nutritional and physico-chemical characteristics of stored beans (Phaseolus vulgaris L.)

    International Nuclear Information System (INIS)

    Mancini Filho, J.

    1990-01-01

    The radiation effects on physico-chemical and nutritional characteristics of three Brazilian varieties of beans (Phaseolus vulgaris, L.) - Catu, Rajado and Carioca -were studied. The analytical parameters were obtained by the determination of soaking and cooking times, biological value in rats, protein electrophoretic profile, reductors sugars, oligosaccharides, fiber and fatty acids content. Also, amyloglucosidase, phytohemagglutinins, α-amylase and tryptic inhibitors activities were analysed. It was observed the gamma radiation until determined doses promotes changes on those parameters subsequently reducing substantially the cooking time without modification of the biological value of the proteins. This alteration was particularly noticed in the hard-to-cook beans. (author)

  13. White emission from nano-structured top-emitting organic light-emitting diodes based on a blue emitting layer

    International Nuclear Information System (INIS)

    Hyun, Woo Jin; Park, Jung Jin; Park, O Ok; Im, Sang Hyuk; Chin, Byung Doo

    2013-01-01

    We demonstrated that white emission can be obtained from nano-structured top-emitting organic light-emitting diodes (TEOLEDs) based on a blue emitting layer (EML). The nano-structured TEOLEDs were fabricated on nano-patterned substrates, in which both optical micro-cavity and scattering effects occur simultaneously. Due to the combination of these two effects, the electroluminescence spectra of the nano-structured device with a blue EML exhibited not only blue but also yellow colours, which corresponded to the intrinsic emission of the EML and the resonant emission of the micro-cavity effect. Consequently, it was possible to produce white emission from nano-structured TEOLEDs without employing a multimode micro-cavity. The intrinsic emission wavelength can be varied by altering the dopant used for the EML. Furthermore, the emissive characteristics turned out to be strongly dependent on the nano-pattern sizes of the nano-structured devices. (paper)

  14. Characteristic of resistant ionization-radiation and its relationship with polysaccharide contents in spirulina

    International Nuclear Information System (INIS)

    Wang Zhiping; Xu Bujin

    2001-01-01

    The anti-radiation capacities of intact filaments, no-sheath filaments and cells of 4 kinds of Spiralina strains (Ss-V, Sp-F, Sp-Z and Sp-D) treated by "6"0Co γ-rays were studied. The relationship between polysaccharide contents and anti-radiation capacity of 4 strains were also detected. The results showed that Spirulina is highly resistant toγ-radiation, however there were significant differences with various strains. The order of anti-radiation capacity is Ss-V > Sp-F > Sp-Z > Sp-D. Moreover, the anti-radiation capacity were remarkably related with polysaccharide contents in the 4 strains. This showed that polysaccharide is very important for raising and maintain-ing super anti-radiation capacity in Spiralina. (authors)

  15. Effect of gamma radiation in physico-chemical characteristics of pre-cooked potato

    International Nuclear Information System (INIS)

    Arthur, Valter

    2007-01-01

    The English potato after suffering any kind of processing quickly deteriorates or loses its own characteristics becoming dark, altering its odor, taste, etc. Aiming to increase the time of conservation and maintenance of its integrity are applied some techniques such as: applied atmosphere, refrigeration, vacuum packing and others. The aim of this work was to evaluate the effects of applied gamma radiation in potatoes pre cooked in microwaves aiming to increase their useful life. Potatoes bought at a local grocery store were taken to the Food Irradiation and Radioentomology Laboratory (LIARE/CENA) in Piracicaba, SP. The tubercles were washed in running water, peeled, cut into semi-circled shapes, sanitized in a sodium hypochlorite solution and submitted to a five-minute pre-cooking in microwaves at a rate of 3:5 potato and water respectively. After the cooking, the potatoes were drained, cooled in the environment temperature, packed into transparent and flexible plastic packing and irradiated with doses of: 0,0 (control) 1,0 and 2,0 kGy. After the irradiation the samples were put under refrigeration of (6+2 deg C) and analyzed 1, 3, 6, 8 and 13 days in the following requisites: loss of fresh mass and sensorial appearance (color, odor and texture). All the potatoes presented exudation and consequently, loss of fresh mass; the irradiated samples presented alteration in the odor and color (discoloration - inactivation of pigments such as xanthines) in less time than the control samples, accelerating the process of darkening on spots and injuries that existed, besides the dry of the surfaces. In general sense, the irradiation in pre-cooked potatoes in the doses of 1,0 and 2,0 kGy did not present any satisfactory result in potato conservation. (author)

  16. Characteristic 8 keV X rays possess radiobiological properties of higher-LET radiation.

    Science.gov (United States)

    Shridhar, Ravi; Estabrook, William; Yudelev, Mark; Rakowski, Joseph; Burmeister, Jay; Wilson, George D; Joiner, Michael C

    2010-03-01

    Electronic brachytherapy systems are being developed that can deliver X rays of varying energy depending on the material of a secondary target. A copper target produces characteristic 8 keV X rays. Our aim was to determine whether 8 keV X rays might deliver greater biological effectiveness than megavoltage photons. Cells of the U251 human glioma cell line were used to compare the biological effects of 8 keV X rays and (60)Co gamma rays in terms of relative biological effectiveness (RBE), oxygen enhancement ratio (OER), and DNA damage. The RBE at 50% and 10% survival was 2.6 and 1.9, respectively. At 50% survival, the OER for cells treated with 8 keV X rays was 1.6 compared with 3.0 for (60)Co gamma rays. The numbers of H2AX foci per Gy after treatment with 8 keV X rays and (60)Co gamma rays were similar; however, the size of the foci generated at 8 keV was significantly larger, possibly indicating more complex DNA damage. The mean area of H2AX foci generated by 8 keV X rays was 0.785 microm(2) (95% CI: 0.756-0.814) compared with 0.491 microm(2) (95% CI: 0.462-0.520) for (60)Co gamma rays (P X rays produce two to three times the biological effectiveness of megavoltage photons, with a radiobiological profile similar to higher-LET radiations.

  17. Effect of gamma radiation in physico-chemical characteristics of pre-cooked potato

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Valter [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia]. E-mail: arthur@cena.usp.br; Sanches, Maria Angelica Santos Fernandes; Amaral, Frederico Scarin do [Fundacao Educacional de Fernandopolis (FEFSP), Fernandopolis, SP (Brazil)]. E-mails: maengal@yahoo.com.br; frescarin@yahoo.com.br

    2007-07-01

    The English potato after suffering any kind of processing quickly deteriorates or loses its own characteristics becoming dark, altering its odor, taste, etc. Aiming to increase the time of conservation and maintenance of its integrity are applied some techniques such as: applied atmosphere, refrigeration, vacuum packing and others. The aim of this work was to evaluate the effects of applied gamma radiation in potatoes pre cooked in microwaves aiming to increase their useful life. Potatoes bought at a local grocery store were taken to the Food Irradiation and Radioentomology Laboratory (LIARE/CENA) in Piracicaba, SP. The tubercles were washed in running water, peeled, cut into semi-circled shapes, sanitized in a sodium hypochlorite solution and submitted to a five-minute pre-cooking in microwaves at a rate of 3:5 potato and water respectively. After the cooking, the potatoes were drained, cooled in the environment temperature, packed into transparent and flexible plastic packing and irradiated with doses of: 0,0 (control) 1,0 and 2,0 kGy. After the irradiation the samples were put under refrigeration of (6+2 deg C) and analyzed 1, 3, 6, 8 and 13 days in the following requisites: loss of fresh mass and sensorial appearance (color, odor and texture). All the potatoes presented exudation and consequently, loss of fresh mass; the irradiated samples presented alteration in the odor and color (discoloration - inactivation of pigments such as xanthines) in less time than the control samples, accelerating the process of darkening on spots and injuries that existed, besides the dry of the surfaces. In general sense, the irradiation in pre-cooked potatoes in the doses of 1,0 and 2,0 kGy did not present any satisfactory result in potato conservation. (author)

  18. Safety of light emitting diodes in toys.

    Science.gov (United States)

    Higlett, M P; O'Hagan, J B; Khazova, M

    2012-03-01

    Light emitting diodes (LEDs) are increasingly being used in toys. An assessment methodology is described for determining the accessible emission limits for the optical radiation from the toys, which takes account of expected use and reasonably foreseeable misuse of toys. Where data are available, it may be possible to assess the toy from the data sheet alone. If this information is not available, a simple measurement protocol is proposed.

  19. Safety of light emitting diodes in toys

    International Nuclear Information System (INIS)

    Higlett, M P; O'Hagan, J B; Khazova, M

    2012-01-01

    Light emitting diodes (LEDs) are increasingly being used in toys. An assessment methodology is described for determining the accessible emission limits for the optical radiation from the toys, which takes account of expected use and reasonably foreseeable misuse of toys. Where data are available, it may be possible to assess the toy from the data sheet alone. If this information is not available, a simple measurement protocol is proposed.

  20. Centralizing and decentralizing the system for unifying measurements on ionizing-radiation characteristics (medium-energy photon and charged-particle radiometry and spectrometry)

    International Nuclear Information System (INIS)

    Bregadze, Yu.I.; Stepanov, E.K.

    1993-01-01

    Ionizing-radiation applications have gradually defined the physical quantities needed to describe radiation sources, radiation as such, and interactions with matter. The optimum unit system has not yet been defined, since new regularities appear during research on the interactions of radiation with matter, and new relationships are being discovered between the radiation characteristics and the observed effects. There are 13 state primary standards in the measurement of ionizing radiation. Several of the standards reproduce the same unit but for different forms of radiation, while special standards reproduce units under special conditions. The present article discusses the various approaches to centralizing and decentralizing systems of supporting unified measurements for various ionizing-radiation characteristics. The three basic physical quantities used to characterize radioactive sources -- radionuclide activity, external particle emission, and particle energy -- are addressed separately. 10 refs

  1. Fabrication of radiation sources for educational purposes from chemical fertilizers using compressing and forming method

    International Nuclear Information System (INIS)

    Kawano, Takao

    2008-01-01

    Chemical fertilizers contain potassium, which is composed of a small amount of naturally occurring potassium-40. The potassium-40 radionuclide emits beta and gamma radiation. Three brands of chemical fertilizer were used to fabricate disk-shaped radiation sources and the fabricated radiation sources were examined for applicability to an educational radiation course. In the examination, tests to determine dependence of count rate on distance, shielding thickness, and shielding materials were conducted using the radiation sources. Results showed that radiation sources fabricated from the three brands of chemical fertilizer were equivalent for explaining radiation characteristics, particularly those related to the dependence of radiation strength on distance and shielding thickness. The relation between shielding effect and mass density can be explained qualitatively. Thus, chemical fertilizer radiation sources can be a useful teaching aid for educational courses to better promote understanding of radiation characteristics and the principles of radiation protection. (author)

  2. Assessment of environmental gamma radiation levels at locations having different source characteristics using TLDs

    International Nuclear Information System (INIS)

    Sahu, S.K.; Swarnkar, M.; Takale, R.A.; Shetty, P.G.; Pandit, G.G.; Puranik, V.D.

    2012-01-01

    Naturally occurring radionuclides are the major contributor to the total effective dose of ionizing radiation received by the population (UNSCEAR, 1993). The dose in environment thus depends largely on natural radiation than manmade or artificially produced radiation. In the last few decades, there is a growing concern all over the world about radiation and their exposure to population. Thus, it is a necessity to conduct frequent radiological environmental surveillance in order to assess population exposure accurately. Recently, application of thermoluminescence dosimeters (TLDs) has been extended to the measurement of mixed radiation field as encountered in the environment. The advantages of passive TL dosimeters for environmental monitoring are that they are small, cheap and do not require power supply during application. The passive TL dosimeters play an important role to provide data on natural background radiation and to determine the contribution to the dose to public from man-made sources. In the present study, three different sites were chosen to compare environmental gamma radiation levels in different scenarios. Kaiga has been chosen as site 1, where four unit of pressurized heavy water reactor (PHWR) of 220 MWe each are in operation. Site 2 is chosen at natural high background radiation area (NHBRA) of Kerala and Vishakhapatnam was chosen as site 3, which is situated at a normal background area. The objective of the study is to illustrate the effect, if any, of an operating nuclear power reactor on environmental gamma radiation levels

  3. Collection of radiation resistant characteristics reports for instruments and materials in high dose rate environment

    International Nuclear Information System (INIS)

    Kusano, Joichi

    2008-03-01

    This document presents the collected official reports of radiation irradiation study for the candidate materials to be used in high dose rate environment as J-PARC facility. The effect of radiation damage by loss-beam or secondary particle beam of the accelerators influences the performance and the reliability of various instruments. The knowledge on the radiation resistivity of the materials is important to estimate the life of the equipments, the maintenance interval and dose evaluation for the personnel at the maintenance period. The radiation damage consists with mechanical property, electrical property and gas-evolution property. (author)

  4. Deterministic and stochastic methods of calculation of polarization characteristics of radiation in natural environment

    Science.gov (United States)

    Strelkov, S. A.; Sushkevich, T. A.; Maksakova, S. V.

    2017-11-01

    We are talking about russian achievements of the world level in the theory of radiation transfer, taking into account its polarization in natural media and the current scientific potential developing in Russia, which adequately provides the methodological basis for theoretically-calculated research of radiation processes and radiation fields in natural media using supercomputers and mass parallelism. A new version of the matrix transfer operator is proposed for solving problems of polarized radiation transfer in heterogeneous media by the method of influence functions, when deterministic and stochastic methods can be combined.

  5. Electromagnetic radiation of electrons in periodic structures

    International Nuclear Information System (INIS)

    Potylitsyn, Alexander Petrovich

    2011-01-01

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

  6. Research on the electromagnetic radiation characteristics of the gas main switch of a capacitive intense electron-beam accelerator

    Directory of Open Access Journals (Sweden)

    Yongfeng Qiu

    2017-11-01

    Full Text Available Strong electromagnetic fields are radiated during the operation of the intense electron-beam accelerator (IEBA, which may lead to the nearby electronic devices out of order. In this paper, the research on the electromagnetic radiation characteristic of the gas main switch of a capacitive IEBA is carried out by the methods of theory analysis and experiment investigation. It is obtained that the gas main switch is the dominating radiation resource. In the absence of electromagnetic shielding for the gas main switch, when the pulse forming line of the IEBA is charged to 700 kV, the radiation field with amplitude of 3280 V/m, dominant frequency of 84 MHz and high frequency 100 MHz is obtained at a distance of 10 meters away from the gas main switch. The experimental results of the radiation field agree with the theoretical calculations. We analyze the achievements of several research groups and find that there is a relationship between the rise time (T of the transient current of the gas main switch and the dominant frequency (F of the radiation field, namely, F*T=1. Contrast experiment is carried out with a metal shield cover for the gas main switch. Experimental results show that for the shielded setup the radiation field reduces to 115 V/m, the dominant frequency increases to 86.5 MHz at a distance of 10 away meters from the gas main switch. These conclusions are beneficial for further research on the electromagnetic radiation and protection of the IEBA.

  7. Public Health Ministere stablish that all medical equipment records request who emit ionizing radiations providing health organizations, Public or privates, such as enterprise who trade medical products, have to be carry out between of the Public a Health Ministere Technology Department and DINATEN of the Industry energy and Mining Ministere

    International Nuclear Information System (INIS)

    2004-01-01

    The present decree stablish that the evaluation of all the applications of registration of medical teams that emit ionizing radiations, coming from the institutions of health, you publish or private, as well as companies that market medical products will be carried out among the Department of Technology it Prescribes of the Ministry of Health it Public and the DINATEN of the Ministry of Industry Energy and Mining

  8. Effect of gamma radiation on the viable cell count and some other quality characteristics of dried onions

    International Nuclear Information System (INIS)

    Farkas, J.; El-Nawawy, A.S.

    1973-01-01

    The results of experiments carried out with onion powder and flakes of Egyptian origin show a radiation treatment of 0.1-0.2 Mrad sufficient to reduce the microbial contamination of dried onions by one order of magnitude. To achieve a 99% reduction, satisfactory from the practical point of view, treatment with 0.5-0.6 Mrad seems necessary. With increasing radiation doses the characteristic smell of dried onions diminished and a caramel-like off-odour appeared and the colour of the dried products darkened. These changes become significant only above treatment with 0.8 Mrad. The differences between radiation treated and untreated samples both packed in Cellothene pouches were either eliminated (odour) or diminished (colour) during 6 weeks storage following irradiation. The results obtained by the chemical oxygen demand method (COD) based on bichromate oxidation of water soluble volatile reducing substances, were not in accord with the organoleptically observable changes of odour. (F.J.)

  9. 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.

  10. Characteristics Of Oral Condition Among Workers In The Field Of Radiation

    International Nuclear Information System (INIS)

    Sallam, R.A.I.

    2012-01-01

    We live in radioactive world. Radiation is permanently present through out the environment whether from natural and / or artificial sources. Natural sources contribute about four to five times as much as artificial ones; they could be in the form of cosmic radiation, rocks, natural radium, uranium and thorium. Artificial source could be from medical radiation sources, industrial uses and nuclear technologies. Ionizing radiation negative biological effect on living organisms depends on dose of radiation and duration of exposure. Prolonged exposure to radiation particularly ionizing radiation has adverse effects on human health and immunity leading to systemic diseases. Different tissues of the body respond differently to radiation, due to varying degrees of radio sensitivity. When an adult subject is irradiated over the entire body, various syndromes are manifested depending on the dose applied. The effects of radiation are characterized by the survival time the species and various stages of acute syndromes following the total body irradiation. These effects are deterministic types and have a threshold dose. The long term or late effects of radiation cause various syndromes long after the radiation exposure. These may appear after acute radiation syndrome subside following exposure to a single large dose or after exposure to many smaller doses over a period. The late effects may be somatic or genetic, depending on the respective cells involved. Somatic effects are seen in the form of carcinogenesis, life shortening, cataract genesis, and embryologic damage. On the other hand, genetic effects result in abnormalities in the offspring. Dental diseases don't differ from any other diseases as the environmental factors may moderate dental diseases from day to day (Van Haute and Green, 1974). Occupational disease of hard and soft oral structures is due to direct action of the occupational causative agent on the workers oral tissue, which is affected as part of systemic

  11. Toxicity studies of inhaled beta-emitting radionuclides - Status report

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, F F; Boeker, B B; Gillett, N A; Griffith, W C; Lundgren, D L; McClellan, R O; Muggenburg, B A; Snipes, M B

    1988-12-01

    The effects of beta-emitting radionuclides inhaled in either a relatively soluble form ({sup 90}SrCl{sub 2}, {sup 144}CeCl{sub 3}, {sup 91}yl{sub 3}, or {sup 137}CsCl) or in a relatively insoluble form ({sup 90}Y, {sup 91}Y, {sup 144}Ce or {sup 90}Sr in fused aluminosilicate particles [FAP]) have been studied in laboratory animals. The results showed that the total beta dose and the dose-rate pattern can modify both the neoplastic and non-neoplastic effects of inhaled beta-emitting radionuclides. In addition, the solubility and chemical characteristics of the radionuclides influence which organs are affected. Effects are seen primarily in organs where the radionuclide is ultimately accumulated, e.g., lung, bone, liver, or tracheobronchial lymph nodes. In addition, effects may be seen in organs where there is little accumulation, but where the radiation dose may still be high, e.g., nasal epithelium and heart. Studies of inhaled {sup 144}Ce-FAP in four different species showed that, compared to mice and dogs, lung tumor risk factors are very low for Syrian hamsters and high for rats. Studies of mice, Syrian hamsters, rats, and dogs repeatedly exposed to aerosols of {sup 144}Ce-FAP showed that lung tumor incidence correlates better with cumulative dose to the lung than with dose rate. Most of the studies in this program are nearing completion and full analyses are in progress. (author)

  12. Top-emitting organic light-emitting diodes.

    Science.gov (United States)

    Hofmann, Simone; Thomschke, Michael; Lüssem, Björn; Leo, Karl

    2011-11-07

    We review top-emitting organic light-emitting diodes (OLEDs), which are beneficial for lighting and display applications, where non-transparent substrates are used. The optical effects of the microcavity structure as well as the loss mechanisms are discussed. Outcoupling techniques and the work on white top-emitting OLEDs are summarized. We discuss the power dissipation spectra for a monochrome and a white top-emitting OLED and give quantitative reports on the loss channels. Furthermore, the development of inverted top-emitting OLEDs is described.

  13. Characteristic properties of crystals. Their demonstration; Proprietes caracteristiques des cristaux. Mise en evidence

    Energy Technology Data Exchange (ETDEWEB)

    Lesueur, C

    1951-03-01

    The characteristic properties of scintillation crystals discussed are the photon spectrum emitted by passage of a particle, number of these photons, transparence of the crystal to its own fluorescence radiation, and decay period of the fluorescence. The experimental apparatus, consisting of photomultiplier tube, preamplifier, amplifier, discriminator, and scaler, is described, and the experimental evaluation of the characteristic properties is discussed. Results of tests on various crystals with {alpha} and {beta} radiations are reported graphically.

  14. Examples of Radiation-Emitting Products

    Science.gov (United States)

    ... Ultrasonography • Doppler ultrasound • Color doppler ultrasound • Hyperthermia • Diathermy/physical therapy • Bone healing • Lithotripsy • Phacoemulsifier • Needle guide • Bone density measuring • Geriatric bath (ultrasound) • Hearing aid • Many scientific uses • Nondestructive ...

  15. POWER, METALLURGICAL AND CHEMICAL MECHANICAL ENGINEERING THERMOELECTRIC EVENTS IN LIGHT-EMITTING BIPOLAR SEMICONDUCTOR STRUCTURES

    Directory of Open Access Journals (Sweden)

    P. A. Magomedova

    2017-01-01

    Full Text Available Objective. The development of light-emitting bipolar semiconductor structures having a low level of parasitic heat release.Methods. A method for converting thermoelectric heat in bipolar semiconductor structures into optical radiation to divert the excess energy into the environment was developed. At the same time, the cooling effect on thermoelectric junctions remains. Instead of an inertial process of conductive or convective heat transfer, practically instantaneous heat removal from electronic components to the environment takes place.Results. As a result, light-emitting bipolar semiconductor structures will allow more powerful devices with greater speed and degree of integration to be created. It is possible to produce transparent LED matrices with a two-way arrangement of transparent solar cells and mirror metal electrodes along the perimeter. When current is applied, the LED matrix on one of the transitions will absorb thermal energy; on other electrodes, it will emit radiation that is completely recovered into electricity by means of transparent solar cells following repeated reflection between the mirror electrodes. The low efficiency of solar cells will be completely compensated for with the multiple passages of photons through these batteries.Conclusion. Light-emitting bipolar semiconductor structures will not only improve the reliability of electronic components in a wide range of performance characteristics, but also improve energy efficiency through the use of optical radiation recovery. Semiconductor thermoelectric devices using optical phenomena in conjunction with the Peltier effect allow a wide range of energy-efficient components of radio electronic equipment to be realised, both for discrete electronics and for microsystem techniques. Systems for obtaining ultra-low temperatures in order to achieve superconductivity are of particular value. 

  16. IR radiation characteristics of rocket exhaust plumes under varying motor operating conditions

    Directory of Open Access Journals (Sweden)

    Qinglin NIU

    2017-06-01

    Full Text Available The infrared (IR irradiance signature from rocket motor exhaust plumes is closely related to motor type, propellant composition, burn time, rocket geometry, chamber parameters and flight conditions. In this paper, an infrared signature analysis tool (IRSAT was developed to understand the spectral characteristics of exhaust plumes in detail. Through a finite volume technique, flow field properties were obtained through the solution of axisymmetric Navier-Stokes equations with the Reynolds-averaged approach. A refined 13-species, 30-reaction chemistry scheme was used for combustion effects and a k-ε-Rt turbulence model for entrainment effects. Using flowfield properties as input data, the spectrum was integrated with a line of sight (LOS method based on a single line group (SLG model with Curtis-Godson approximation. The model correctly predicted spectral distribution in the wavelengths of 1.50–5.50 μm and had good agreement for its location with imaging spectrometer data. The IRSAT was then applied to discuss the effects of three operating conditions on IR signatures: (a afterburning; (b chamber pressure from ignition to cutoff; and (c minor changes in the ratio of hydroxyl-terminated polybutadiene (HTPB binder to ammonium perchlorate (AP oxidizer in propellant. Results show that afterburning effects can increase the size and shape of radiance images with enhancement of radiation intensity up to 40%. Also, the total IR irradiance in different bands can be characterized by a non-dimensional chamber pressure trace in which the maximum discrepancy is less than 13% during ignition and engine cutoff. An increase of chamber pressure can lead to more distinct diamonds, whose distance intervals are extended, and the position of the first diamond moving backwards. In addition, an increase in HTPB/AP causes a significant jump in spectral intensity. The incremental rates of radiance intensity integrated in each band are linear with the increase of HTPB

  17. The characteristics of peripheral blood leukocytes in persons working with ionizing radiation sources

    International Nuclear Information System (INIS)

    Zykova, I.A.; Sokolova, N.B.; Yas'kova, V.Z.

    1984-01-01

    Functional and qualitative changes of peripheral blood cellular composition were studied in persons working over a long period of time with ionizing radiation sources under the action of various factors of production upon an organism. Appression of a function and increase of T-lymphocyte chromosome damages were revealed against the background of a decrease both of enzymatic activity level and leukocyte number in persons operating for a long time (more than 10 years) with ionizing radiation sources. Discovered changes occurred under the action upon a human being not only of small doses of ionizing radiation but a whole complex of industrial factors which may initiate changes of adapted character

  18. Comparative characteristic of published works on radiation hygiene to optimise information ensuring on the above problem

    International Nuclear Information System (INIS)

    Arkhangel'skaya, G.V.

    1988-01-01

    In the course of investigation of 4 data files on radiation hygiene a topical and geographic structure of data files was determined. Dosimetric and radiobiological aspects were prevailing. Distinguis hing features are present in works on radiation hygiene of various countries. Works on dosimetry are prevailing in the FRG, France. Works on radiobiology are prevailing in Japan, England and in the USSR. Revealing of main primary and secondary sources in radiation hygiene permits to carry out more precisely information research. 12 refs.; 1 tab

  19. Synergistic effects of interstitial impurities and radiation defects on mechanical characteristics of ferritic steels

    International Nuclear Information System (INIS)

    Charit, I.; Seok, C.S.; Murty, K.L.

    2007-01-01

    Ferritic steels are generally used in pressure vessels and various reactor support structures in light water reactors. They are known to exhibit radiation embrittlement in terms of decreased toughness and increased ductile-brittle transition temperature as a result of exposure to neutron radiation. The superimposed effects of strain aging due to interstitial impurity atoms on radiation embrittlement were considered first by Wechsler, Hall and others. Here we summarize some of our efforts on the investigation of synergistic effects between interstitial impurity atoms (IIAs) and radiation-induced point defects, which result in interesting effects at appropriate temperature and strain rate conditions. Two materials, a mild steel and a pressure vessel steel (A516 Gr.70), are evaluated using tensile and three-point bend tests

  20. Study of Radiative Forcing of Dust Aerosols and its impact on Climate Characteristics

    KAUST Repository

    Qureshi, Fawwad H

    2012-12-01

    The purpose of following project is to study the effect of dust aerosols on the radiative forcing which is directly related to the surface temperature. A single column radiative convective model is used for simulation purpose. A series of simulations have been performed by varying the amount of dust aerosols present in the atmosphere to study the trends in ground temperature, heating rate and radiative forcing for both its longwave and shortwave components. A case study for dust storm is also performed as dust storms are common in Arabian Peninsula. A sensitivity analyses is also performed to study the relationship of surface temperature minimum and maximum against aerosol concentration, single scattering albedo and asymmetry factor. These analyses are performed to get more insight into the role of dust aerosols on radiative forcing.

  1. Study on the infrared radiation performance of Tourmaline composite and its effect on the diesel characteristic

    Science.gov (United States)

    Liao, Jian Bin; Yu, Hong Liang; Sun, Di; Ma, Fong Yuan

    2017-09-01

    The black tourmaline, magnesium tourmaline, and spinel were ground into powder, and the infrared radiation material was prepared by adding the ceramic powder, clay and the other material into the tourmaline powder according to a certain proportion. The infrared radiation property was tested and analyzed, the diesel was infrared radiation activated by the composite material, and the physicochemical property of fuel oil was analyzed pre-test and post-test. The result shows that the infrared absorption spectrum of the black tourmaline of different particle size is stable. After the diesel oil was infrared radiation activated by tourmaline composite materials, the physicochemical property of diesel oil was changed, the activation energy decreased, the viscosity and surface tension of fuel oil were reduced.

  2. Human genetics studies in areas of high natural radiation.V. regional and populational characteristics

    International Nuclear Information System (INIS)

    Freire-Maia, A.

    1974-01-01

    The region with high level of background radiation studied in our project is described. In the total, 8.572 couples and 43.930 pregnancy terminations were analyzed. The populational distribution of the 'relaive time of exposure to radiation' (coefficient R) is presented. The distributions of ethnic groups, alien ancestrals, mortality, morbidity, sex ratio, conditions of the household, instruction of the mother, and mean coefficients of inbreeding are also given, all the distributions are given comparatively for control and irradiated groups [pt

  3. Human genetics studies in areas of high natural radiation. V. regional and populational characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Freire-Maia, A [Faculdade de Ciencias Medicas e Biologicas de Botucatu (Brazil). Departamento de Genetica

    1974-12-01

    The region with high level of background radiation studied in our project is described. In the total, 8.572 couples and 43.930 pregnancy terminations were analyzed. The populational distribution of the 'relaive time of exposure to radiation' (coefficient R) is presented. The distributions of ethnic groups, alien ancestrals, mortality, morbidity, sex ratio, conditions of the household, instruction of the mother, and mean coefficients of inbreeding are also given, all the distributions are given comparatively for control and irradiated groups.

  4. Simulating of spectrum and polarization characteristics of ultrarelativistic - electron coherent radiation in a diamond crystal

    International Nuclear Information System (INIS)

    Truten', V.I.

    2000-01-01

    On the base of the computer simulation method it is shown that new maxima of ultrarelativistic electron radiation spectrum in aligned crystals may appear in a low-frequency region together with the ordinary coherent maxima. The appearance of these maxima is the result of the high-index-crystal-plane effect. These maxima manifest themselves in spectral as well as in polarization features of radiation [ru

  5. Impact of post-harvest radiation treatment timing on shelf life and quality characteristics of potatoes

    International Nuclear Information System (INIS)

    Rezaee, Mehdi; Paknejad, Farzad; Almassi, Morteza; Minaei, Saeed

    2013-01-01

    The effects of gamma radiation treatment (50 and 100 Gy) on potato tubers irradiated at different days (10th, 30th and 50th) after harvest were studied during 5 months of storage at 10°C using Agria and Marfona varieties. A factorial experiment was done, based on a Randomized Complete Block Design with four replications. The 100 Gy radiation treatments on 10th and 30th days after harvest completely prevented sprouting at both varieties studied but on 50th day only Agria tubers did not sprout. This study indicated that early irradiation and absorbed radiation doses significantly decreased sprouting, percent weight loss and specific gravity of tubers. Reducing sugar content significantly increased by delay in irradiation and lower dose of radiation while non-reducing sugars did not decrease significantly by delay in irradiation and higher dose of radiation. The least increase in reducing sugars (10.2%) and most decrease in non-reducing sugar (-12.75%) were observed in tubers that irradiated on 10th day after harvest. The content of ascorbic acid was decreased by irradiation with higher dose. Although delay in irradiation caused less loss of ascorbic acid (8.5%) but showed greater metabolic changes as sprouting, weight loss, firmness, and sugars contents. Also, more increased delay in irradiation needed higher radiation doses for sprout inhibition. (author)

  6. 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

  7. Power output and efficiency of beta-emitting microspheres

    International Nuclear Information System (INIS)

    Cheneler, David; Ward, Michael

    2015-01-01

    Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is comprised of a pure radioisotope with beta particles being emitted isotropically throughout the material. The full initial possible kinetic energy distribution of a beta particle is taken into account as well as the energy losses due to scattering by other atoms in the microsphere and bremsstrahlung radiation. By combining Longmire’s theory of the mean forward range of charged particles and the Rayleigh distribution to take into account the statistical nature of scattering and energy straggling, the linear attenuation, or self-absorption, coefficient for beta-emitting radioisotopes has been deduced. By analogy with gamma radiation transport in spheres, this result was used to calculate the rate of energy emitted by a beta-emitting microsphere and its efficiency. Comparisons to standard point dose kernel formulations generated using Monte Carlo data show the efficacy of the proposed method. Yttrium-90 is used as a specific example throughout, as a medically significant radioisotope, frequently used in radiation therapy for treating cancer. - Highlights: • Range-energy relationship for the beta particles in yttrium-90 is calculated. • Formalism for the semi-analytical calculation of self-absorption coefficients. • Energy-dependent self-absorption coefficient calculated for yttrium-90. • Flux rate of beta particles from a self-attenuating radioactive sphere is shown. • The efficiency of beta particle emitting radioactive microspheres is calculated

  8. Critical Characteristics of Radiation Detection System Components to be Dedicated for use in Safety Class and Safety Significant System

    International Nuclear Information System (INIS)

    DAVIS, S.J.

    2000-01-01

    This document identifies critical characteristics of components to be dedicated for use in Safety Significant (SS) Systems, Structures, or Components (SSCs). This document identifies the requirements for the components of the common, radiation area, monitor alarm in the WESF pool cell. These are procured as Commercial Grade Items (CGI), with the qualification testing and formal dedication to be performed at the Waste Encapsulation Storage Facility (WESF) for use in safety significant systems. System modifications are to be performed in accordance with the approved design. Components for this change are commercially available and interchangeable with the existing alarm configuration This document focuses on the operational requirements for alarm, declaration of the safety classification, identification of critical characteristics, and interpretation of requirements for procurement. Critical characteristics are identified herein and must be verified, followed by formal dedication, prior to the components being used in safety related applications

  9. Salinity effects on radiation utilization characteristics of Kochia (Kochia Scoparia L. Schrad.)

    International Nuclear Information System (INIS)

    Jami Al-Ahmadi, M.; Kafi, M.; Nassiri Mahalati, M.

    2008-01-01

    In order to evaluate light extinction coefficient and radiation use efficiency of Kochia scoparia in response to saline stress, a study was performed at Birjand, South Khorasan, using three levels of salinity in irrigation water (1.5, 8.6 and 28.2 dSm-1) with three replications. Several measurements were conducted during growth season to calculate radiation fraction passed through plant canopy, and also leaf area index (LAI) and total dry matter (TDM). Light extinction coefficient calculated with correcting fraction of plant light absorption for whole day, and using dry matter accumulation, radiation use efficiency obtained in each different salinity level. The results showed that light extinction coefficient of Kochia was equal to 0.59 for solar noon and 0.75 for whole day. The radiation absorption of kochia rose as LAI increased, and 95% of radiation was absorbed at LAI equal to 4 to 5. LAI and total dry matter accumulation were highest in moderate salinity level. In general, increase in salinity caused a delay in early season development, and accelerated plant maturity at late season. This caused plant canopies at the highest salinity reached to maximum light absorption later in growth season. Increase of salinity from 1.5 to 8.6 dSm-1 was responsible for little increase in RUE from 2.4 to 2.5 g per MJ absorbed PAR; however, it reduced with further increase in salinity. Thus, it seems that moderate salinity levels stimulate growth and dry matter accumulation of kochia and cause kochia canopy convert the absorbed radiation to dry matter more effectively. Key words: Kochia scoparia, Salinity, Light extension coefficient, Radiation use efficiency, Leaf Area Index

  10. Current status of the infrastructure and characteristics of radiation oncology in Korea

    International Nuclear Information System (INIS)

    Huh, Seung Jae

    2007-01-01

    An analysis of radiotherapy infrastructure in Korea was performed in 2006 to collect data on treatment devices, the work force and new patients for future development plans. The survey included radiotherapy centers, their major equipment and personnel. The centers were categorized into four levels: level 0 (stand-alone teletherapy units); level 1 (teletherapy, brachytherapy, treatment planning system, and at least the part-time service of a medical physicist); level 2 (level 1 plus individual customized radiotherapy block and full-time medical physicist); and level 3 [level 2 plus intensity-modulated radiation therapy (IMRT), intra-operative radiation therapy or stereotactic radiotherapy]. A total of 61 facilities delivered radiation therapy with 104 megavoltage devices, which included 96 linear accelerators, two cobalt 60 units, three Tomotherapy, two CyberKnife units and one proton accelerator. There were 28789 new radiotherapy patients in 2004. Personnel included 132 radiation oncologists, 50 radiation oncology residents, 64 physicists, 130 nurses and 369 radiation therapy technologists. Thirty-two percent (20 facilities) used a CT-simulator, 66% (40) used a positron emission tomography (PET) or PET-CT scanner, and 35% (22) had the capacity to implement IMRT. Centers were also divided into four levels: 41% were included in level 3, 31% in level 2, 25% in level 1 and 3% in level 0. There is a shortage of human resources. The distribution of megavoltage units per million inhabitants over the country was inadequate; geographic disparities were noted. Furthermore, the necessity of quality assurance for recent high-technology radiation therapy is increasing. (author)

  11. Radiation impact on the characteristics of optical glasses test results on a selected set of materials

    Science.gov (United States)

    Fruit, Michel; Gussarov, Andrei; Berghmans, Francis; Doyle, Dominic; Ulbrich, Gerd

    2017-11-01

    It is well known within the Space optics community that radiation may significantly affect transmittance of glasses. To overcome this drawback, glass manufacturers have developed Cerium doped counterparts of classical glasses. This doped glasses display much less transmittance sensitivity to radiation. Still, the impact of radiation on refractive index is less known and may affect indifferently classical or Cerium doped glasses. ESTEC has initialised an R&D program with the aim of establishing a comprehensive data base gathering radiation sensitivity data, called Dose coefficients, for all the glass optical parameters (transmittance / refractive index / compaction……). The first part of this study, to define the methodology for such a data base, is run by ASTRIUM SAS in co-operation with SCK CEN. This covers theoretical studies associated to testing of a selected set of classical and "radiation hardened" glasses. It is proposed here to present first the theoretical backgrounds of this study and then to give results which have been obtained so far.

  12. A Global Modeling Study on Carbonaceous Aerosol Microphysical Characteristics and Radiative Effects

    Science.gov (United States)

    Bauer, S. E.; Menon, S.; Koch, D.; Bond, T. C.; Tsigaridis, K.

    2010-01-01

    Recently, attention has been drawn towards black carbon aerosols as a short-term climate warming mitigation candidate. However the global and regional impacts of the direct, indirect and semi-direct aerosol effects are highly uncertain, due to the complex nature of aerosol evolution and the way that mixed, aged aerosols interact with clouds and radiation. A detailed aerosol microphysical scheme, MATRIX, embedded within the GISS climate model is used in this study to present a quantitative assessment of the impact of microphysical processes involving black carbon, such as emission size distributions and optical properties on aerosol cloud activation and radiative effects. Our best estimate for net direct and indirect aerosol radiative flux change between 1750 and 2000 is -0.56 W/m2. However, the direct and indirect aerosol effects are quite sensitive to the black and organic carbon size distribution and consequential mixing state. The net radiative flux change can vary between -0.32 to -0.75 W/m2 depending on these carbonaceous particle properties at emission. Taking into account internally mixed black carbon particles let us simulate correct aerosol absorption. Absorption of black carbon aerosols is amplified by sulfate and nitrate coatings and, even more strongly, by organic coatings. Black carbon mitigation scenarios generally showed reduced radiative fluxeswhen sources with a large proportion of black carbon, such as diesel, are reduced; however reducing sources with a larger organic carbon component as well, such as bio-fuels, does not necessarily lead to a reduction in positive radiative flux.

  13. The inaccuracy of heat transfer characteristics for non-insulated and insulated spherical containers neglecting the influence of heat radiation

    International Nuclear Information System (INIS)

    Wong, King-Leung; Salazar, Jose Luis Leon; Prasad, Leo; Chen, Wen-Lih

    2011-01-01

    In this investigation, the differences of heat transfer characteristics for insulated and non-insulated spherical containers between considering and neglecting the influence of heat radiation are studied by the simulations in some practical situations. It is found that the heat radiation effect cannot be ignored in conditions of low ambient convection heat coefficients (such ambient air) and high surface emissivities, especially for the non-insulated and thin insulated cases. In most practical situations when ambient temperature is different from surroundings temperature and the emissivity of insulation surface is different from that of metal wall surface, neglecting heat radiation will result in inaccurate insulation effect and heat transfer errors even with very thick insulation. However, the insulation effect considering heat radiation will only increase a very small amount after some dimensionless insulated thickness (such insulation thickness/radius ≥0.2 in this study), thus such dimensionless insulated thickness can be used as the optimum thickness in practical applications. Meanwhile, wrapping a material with low surface emissivity (such as aluminum foil) around the oxidized metal wall or insulation layer (always with high surface emissivity) can achieve very good insulated effect for the non-insulated or thin insulated containers.

  14. Effect of high-energy radiation on the rheological characteristics and structure of liquid rubbers

    International Nuclear Information System (INIS)

    Govorkov, A.T.; Zaitseva, V.I.; Muryshkin, D.L.; Safonov, Yu.N.

    1987-01-01

    The effect of high-energy radiation (γ-radiation and accelerated electrons) on liquid polybutadiene and polyisoprene rubbers (SKD, SKD-KTR, SKN) and butyl rubber (BR) was studied by IR and EPR spectroscopy, rheoviscosimetry, and chemical analysis. Newtonian flow was conserved in the rubbers under irradiation. The activation energy of viscous flow was unchanged, evidence of an increase in the contour length of the macromolecules without significant branching and cross-linking at the initial stages of the irradiation. A quantitative relationship was established between the rubber's dynamic viscosity and the absorbed dose, and features of the structure-formation mechanism in the liquid rubbers were determined

  15. Tuning characteristics of narrowband THz radiation generated via optical rectification in periodically poled lithium niobate.

    Science.gov (United States)

    Weiss, C; Torosyan, G; Meyn, J P; Wallenstein, R; Beigang, R; Avetisyan, Y

    2001-04-23

    The tuning properties of pulsed narrowband THz radiation generated via optical rectification in periodically poled lithium niobate have been investigated. Using a disk-shaped periodically poled crystal tuning was easily accomplished by rotating the crystal around its axis and observing the generated THz radiation in forward direction. In this way no beam deflection during tuning was observed. The total tuning range extended from 180 GHz up to 830 GHz and was limited by the poling period of 127 microm which determines the maximum THz frequency in forward direction.

  16. A comparative study on thermal, mechanical and dielectric characteristics of low density polyethylene crosslinked by radiation and chemical methods

    International Nuclear Information System (INIS)

    Kim, B.H.; Ling, D.Y.; Kim, J.S.

    1976-01-01

    A comparative study on thermal, static mechanical and dielectric characteristics were made over a temperature range of ca. 20 0 C to 320 0 C and a frequency range of KHZ band on low density polyethylene specimens crosslinked, respectively, by radiation and chemical method. The thermal property of both specimens shows that softening point appears to unchange by crosslinking however, melting and liquidizing temperatures attain rapid increase at the imitation of crosslinking. Mechanical properties show little difference to both specimens crosslinked by different method, further the behaviors were discussed in connection with the relaxation of molecular segments in amorphous phase. Dose dependent dielectric characteristics observed at ambient temperature under several fixed frequencies exhibit extremities at ca. 20 Mrad and the behaviors also were interpreted qualitatively by taking into consideration of dipole concentration change in amorphous phase together with the role of specimen geometry to the depth of oxidative layer. Observing frequency dependent dielectric characteristics, it was also proved that ionic conduction loss is appreciably greater in the specimen prepared by chemical method than that by radiation. (author)

  17. Ecological physiological characteristic of some species of natural vegetation in the Poles'e State Radiation Ecological Reservation

    International Nuclear Information System (INIS)

    Kravchenko, V.A.; Gaponenko, V.I.; Matsko, V.P.; Grushevskaya, O.M.; Bondar', Yu.I.; Evsievich, K.M.; Akadehmiya Navuk Belarusi, Minsk

    1996-01-01

    Influence of radiation on important ecological and physiological characteristics of Pinus silvestris L., Phleum pratense L. and Dactylis glomerata L. growing on territory of the Poles'e State Radiation Ecological Reservation has been investigated in 1992-1994. Significant changes in species and quantitative formation of natural vegetation growing on territory contaminated by the Chernobyl accident release were not observed. Positive correlation between the content of protein in needles of Pinus silvestris L., leaves of Agropyron repens L. and specific radioactivity of photosystem was established. Positive correlation between specific radioactivity of overground photosystem and quantity of nucleic acids (DNA+RNA) is leaves of Dactylis glomerata was found. 8 refs., 2 tabs., 2 figs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

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

  19. Ultraviolet and gamma-radiation effect on the zymotic characteristics of turnip moth's granules

    Energy Technology Data Exchange (ETDEWEB)

    Khakimova, M A

    1975-01-01

    Virus granules of the winter cutworm (Agrotis segetum Schiff) were used as agents for biological control of this pest of field and vegetable crops. The authors first studied the effect of uv and gamma radiation on granules of the cutworm. A purified suspension of winter moth granules, 0.5 mg of granules per mm/sup 3/, was irradiated with a BUV-15 lamp at a distance of 9 cm from the radiation source. The dose rate was 6.6x10/sup 3/ ergs/cm/sup 2/.sec. The results showed that a uv dose of 71.1x10/sup 6/ ergs/cm/sup 2/ decreased the virulence of the granules by a factor of 3 compared to the original suspension (larval mortality of 27.5%) and a dose of 95x10/sup 6/ ergs/cm/sup 2/ completely inactivated the granules. With gamma radiation (/sup 60/Co or /sup 137/Cs) the inactivating dose was only 21.6x10/sup 5/ rads. The work indicated that cutworm granules are very resistant to uv and gamma radiation.

  20. Research on radiation characteristics of dipole antenna modulation by sub-wavelength inhomogeneous plasma layer

    Directory of Open Access Journals (Sweden)

    Fanrong Kong

    2018-02-01

    Full Text Available The modulation and enhancement effect of sub-wavelength plasma structures on compact antennas exhibits obvious technological advantage and considerable progress. In order to extend the availability of this technology under complex and actual environment with inhomogeneous plasma structure, a numerical simulation analysis based on finite element method has been conducted in this paper. The modulation function of the antenna radiation with sub-wavelength plasma layer located at different positions was investigated, and the inhomogeneous plasma layer with multiple electron density distribution profiles were employed to explore the effect of plasma density distribution on the antenna radiation. It has been revealed that the optical near-field modulated distance and reduced plasma distribution are more beneficial to enhance the radiation. On the basis above, an application-focused research about communication through the plasma sheath surrounding a hypersonic vehicle has been carried out aiming at exploring an effective communication window. The relevant results devote guiding significance in the field of antenna radiation modulation and enhancement, as well as the development of communication technology in hypersonic flight.

  1. The retention characteristics of nonvolatile SNOS memory transistors in a radiation environment: Experiment and model

    International Nuclear Information System (INIS)

    McWhorter, P.J.; Miller, S.L.; Dellin, T.A.; Axness, C.L.

    1987-01-01

    Experimental data and a model to accurately and quantitatively predict the data are presented for retention of SNOS memory devices over a wide range of dose rates. A wide range of SNOS stack geometries are examined. The model is designed to aid in screening nonvolatile memories for use in a radiation environment

  2. Dynamic characteristics of serum bioluminescence in dogs with bone marrow radiation sickness

    International Nuclear Information System (INIS)

    Cui Douwan

    1990-01-01

    A theory of competition between biological light and heat, the principle of shift of serum peak and valley and the shift constant ( -0.333) are proposed. The principle of shift of peak and valley may be used as a simple, quick and accurate method for the classification of radiation dose in nuclear accident

  3. Characteristics of fabricated si PIN-type radiation detectors on cooling temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Soo; Jeong, Manhee; Kim, Young Soo [Korea Atomic Energy Research Institute, Jeongeup-si 580-185 (Korea, Republic of); Lee, Dong Hun [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Cho, Seung Yeon [Environmental Health Center, Yonsei University, Wonju-si 1184-4 (Korea, Republic of); Ha, Jang Ho [Korea Atomic Energy Research Institute, Jeongeup-si 580-185 (Korea, Republic of)

    2015-06-01

    Si PIN photodiode radiation detectors with three different active areas (3×3 mm{sup 2}, 5×5 mm{sup 2}, and 10×10 mm{sup 2}) were designed and fabricated at the Korea Atomic Energy Research Institute (KAERI) for low energy X- and gamma-ray detection. In Si-based semiconductor radiation detectors, one of the noise sources is thermal noise, which degrades their energy resolution performance. In this study, the temperature effects on the energy resolution were investigated using a 3×3 mm{sup 2} active area PIN photodiode radiation detector using a Thermoelectric Module (TEM) from room temperature to −23 °C. Energy resolutions from 25 keV auger electrons to 81 keV gamma-ray from a Ba-133 calibration source were measured and compared at every 10 °C interval. At −23 °C, energy resolutions were improved by 15.6% at 25 keV, 4.0% at 31 keV, and 1.2% at 81 keV in comparison with resolutions at room temperature. CsI(Tl)/PIN photodiode radiation detectors were also fabricated for relatively high energy gamma-ray detection. Energy resolutions for Cs-137, Co-60, and Na-22 sources were measured and compared with the spectral responsivity.

  4. Research on radiation characteristics of dipole antenna modulation by sub-wavelength inhomogeneous plasma layer

    Science.gov (United States)

    Kong, Fanrong; Chen, Peiqi; Nie, Qiuyue; Zhang, Xiaoning; Zhang, Zhen; Jiang, Binhao

    2018-02-01

    The modulation and enhancement effect of sub-wavelength plasma structures on compact antennas exhibits obvious technological advantage and considerable progress. In order to extend the availability of this technology under complex and actual environment with inhomogeneous plasma structure, a numerical simulation analysis based on finite element method has been conducted in this paper. The modulation function of the antenna radiation with sub-wavelength plasma layer located at different positions was investigated, and the inhomogeneous plasma layer with multiple electron density distribution profiles were employed to explore the effect of plasma density distribution on the antenna radiation. It has been revealed that the optical near-field modulated distance and reduced plasma distribution are more beneficial to enhance the radiation. On the basis above, an application-focused research about communication through the plasma sheath surrounding a hypersonic vehicle has been carried out aiming at exploring an effective communication window. The relevant results devote guiding significance in the field of antenna radiation modulation and enhancement, as well as the development of communication technology in hypersonic flight.

  5. Study characteristics of new concrete mixes and their mechanical, physical, and gamma radiation attenuation features

    Energy Technology Data Exchange (ETDEWEB)

    El-Samrah, Moamen G.; Abdel-Rahman, Mohamed A.E. [Nuclear Engineering Department, Military Technical College Kobry El-kobbah, Cairo (Egypt); Kany, Amr M.I. [Physics Department, Faculty of Science, Al-Azhar University, Cairo (Egypt)

    2018-02-01

    Ordinary concrete and those of different compositions are regarded as suitable material in many applications concerning with gamma and neutron radiation shielding purposes. They are widely used in nuclear power plant, medical facilities, nuclear shelters, and for radioactive materials transportation as well as storage of radioactive wastes. In this study four different concrete mixes were prepared with the following different types of coarse aggregates: dolomite, barite, goethite, and steel slag. The effect of changes in the fine aggregates, selected to be 50 % local sand and 50 % limonite with addition of 10 % silica fume (SF) and 10 % fly ash (FA) by replacement of the total cement weight, on the performance of the samples was also investigated. To examine the performance of such samples for radiation shielding applications, a set of physical, mechanical, and radiation attenuation properties was studied and compared with those of ordinary concrete. This investigation includes compressive strength, slump test, bulk density, ultrasonic pulse velocity test, and gamma rays attenuation measurements for the different samples. A verification of the experimental results concerning the radiation attenuation measurements was performed using WinXcom program (Version 3.1). The experimental results revealed that all concrete mixes; goethite-limonite concrete (G.L), barite-limonite concrete (B.L), steel slag-limonite concrete (S.L) and dolomite concrete (D.C) have good physical and mechanical properties that successfully satisfying them as high performance concretes. In addition the barite-limonite and the steel slag-limonite have the higher γ-ray attenuation coefficients at low and high energy range and hence have a better radiation shielding. The obtained results from WinXcom program calculations showed a good agreement with the experimental results concerning γ-ray attenuation measurements for the studied concrete mixes. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGa

  6. Hawking radiation

    Science.gov (United States)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  7. Dosimetric characteristics of radiation fields on board Czechoslovak Airlines' aircraft as measured with different active and passive detectors

    International Nuclear Information System (INIS)

    Spurney, F.; Obraz, O.; Pernicka, F.; Votockova, I.; Turek, K.; Vojtisek, O.; Starostova, V.

    1993-01-01

    Dosimetric characteristics on board Czechoslovak Airlines' aircraft (TU 154M; A310-300) were studied with different active and passive detectors (ionisation chamber RSS 112; scintillator based rate meter; GM counter based rate meter; neutron remmeter based on neutron moderation; thermoluminescence detectors, CR 39 track detectors and bubble-damage neutron detectors). Results obtained are analysed and discussed. It is estimated that the dose equivalent rates at altitudes of about 10 km are at least 3-4 μSv.h-1. Conclusions and recommendations for further studies and for radiation protection are given. (author)

  8. Characterizing effects of radiation on forward and reverse saturation characteristics of N-channel devices

    International Nuclear Information System (INIS)

    Jaafar Ali, M.N.; Bhuva, B.; Kerns, S.; Maher, M.; Lawrence, R.

    1999-01-01

    The forward and reverse characteristics of an N-channel device during the saturation mode of operation are used to determine the extent of damage non-uniformity along the channel. The non-uniformity at low total dose exposures is caused by bulk oxide trap. At higher doses, non-uniformity are dominated by interface traps. The unmatched forward and reverse characteristics will be a major problem for memory circuits for advanced technologies. (authors)

  9. Electrical and Optical Enhancement in Internally Nanopatterned Organic Light-Emitting Diodes

    Science.gov (United States)

    Fina, Michael Dane

    Organic light-emitting diodes (OLEDs) have made tremendous technological progress in the past two decades and have emerged as a top competitor for next generation light-emitting displays and lighting. State-of-the-art OLEDs have been reported in literature to approach, and even surpass, white fluorescent tube efficiency. However, despite rapid technological progress, efficiency metrics must be improved to compete with traditional inorganic light-emitting diode (LED) technology. Organic materials possess specialized traits that permit manipulations to the light-emitting cavity. Overall, as demonstrated within, these modifications can be used to improve electrical and optical device efficiencies. This work is focused at analyzing the effects that nanopatterned geometric modifications to the organic active layers play on device efficiency. In general, OLED efficiency is complicated by the complex, coupled processes which contribute to spontaneous dipole emission. A composite of three sub-systems (electrical, exciton and optical) ultimately dictate the OLED device efficiency. OLED electrical operation is believed to take place via a low-mobility-modified Schottky injection process. In the injection-limited regime, geometric effects are expected to modify the local electric field leading to device current enhancement. It is shown that the patterning effect can be used to enhance charge carrier parity, thereby enhancing overall recombination. Current density and luminance characteristics are shown to be improved by OLED nanopatterning from both the model developed within and experimental techniques. Next, the optical enhancement effects produced by the nanopatterned array are considered. Finite-difference time-domain (FDTD) simulations are used to determine positional, spectral optical enhancement for the nanopatterned device. The results show beneficial effects to the device performance. The optical enhancements are related to the reduction in internal radiative

  10. Characteristics of silicon diodes as patient dosemeters in external radiation therapy

    International Nuclear Information System (INIS)

    Nilsson, B.; Sorcini, B.

    1988-01-01

    Silicon diodes connected to an integrating instrument that are used to measure the entrance dose on patients undergoing radiation therapy have been investigated with special emphasis on practical clinical aspects. The variation of the diode response for different photon qualities with different field sizes and different irradiation situations including oblique fields, wedges, blocking filters giving different electron contamination have been measured. The diode response for the different situations met in clinical practice when using various electron energies have also been examined. The results from measurements for patients treated with high energy are presented. The study has shown that if the mean value of all measured entrance doses with the diode on a patient differ more than ±3% from the presented absorbed dose for 60 Co gamma radiation, a correction of the given dose should be made. The corresponding figure for high energy X-rays is ±5%. 23 refs.; 6 figs.; 5 tabs

  11. 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)

  12. Performance characteristics and radiation damage results from the Fermilab E706 silicon microstrip detector system

    Energy Technology Data Exchange (ETDEWEB)

    Engels, E Jr; Mani, S; Orris, D; Shepard, P F; Weerasundara, P D; Choudhary, B C; Joshi, U; Kapoor, V; Shivpuri, R; Baker, W

    1989-07-01

    A charged particle spectrometer containing a 7120-channel silicon microstrip detector system, one component of Fermilab experiment E706 to study direct photon production in hadron-hadron collisions, was utilized in a run in which 6 million events were recorded. We describe the silicon system, provide early results of track and vertex reconstruction, and present data on the radiation damage to the silicon wafers resulting from the narrow high intensity beam. (orig.).

  13. Some neutron and gamma radiation characteristics of plutonium cermet fuel for isotopic power sources

    Science.gov (United States)

    Neff, R. A.; Anderson, M. E.; Campbell, A. R.; Haas, F. X.

    1972-01-01

    Gamma and neutron measurements on various types of plutonium sources are presented in order to show the effects of O-17, O-18 F-19, Pu-236, age of the fuel, and size of the source on the gamma and neutron spectra. Analysis of the radiation measurements shows that fluorine is the main contributor to the neutron yields from present plutonium-molybdenum cermet fuel, while both fluorine and Pu-236 daughters contribute significantly to the gamma ray intensities.

  14. The primary exposure standard for Co-60 gamma radiation: characteristics and measurements procedures

    International Nuclear Information System (INIS)

    Laitano, R.F.; Toni, M.P.

    1983-01-01

    A description is given of a cavity ionization chamber used, as a primary exposure standard, at the Laboratorio di Metrologia delle Radiazioni Ionizzanti of the ENEA in Italy. The primary standard is designed to make absolute measurements of exposure due to the Co-60 gamma radiation. The procedures for the realizationof the exposure unit are also described. Finally results of some international comparisons are reported

  15. Characteristics of long-term survivors of lung cancer treated with radiation

    International Nuclear Information System (INIS)

    Sherman, D.M.; Weichselbaum, R.; Hellman, S.

    1981-01-01

    Between 1968 and 1974, 348 patients with lung cancer were primarily treated with radiation therapy. There were 66 such patients (19%) who survived a minimum of 18 months and are the subject of this report. Of this group, 30 patients have no evidence of disease from 18 to 96 months, with a median followup of 38 months. Thirty-three patients are dead of disease. The five-year acturial survival of the total group of 348 patients was 5.6%. There were 14 stage I and II patients who survived a minimum of 18 months, of whom 11 had no evidence of disease. Of the 42 Stage III patients, 18 presently show no evidence of disease. There were 13 patients who failed with locally recurrent disease; in this group a dose-response relationship was demonstrated. A local failure rate of 50% (4/8) was observed for patients who received fewer than 5000 rad, 22% (6/27) for patients receiving 5000 to 5500 rad, 18% (2/11) in patients receiving 5500 to 5900 rad, and 5% (1/20) for patients who received more than 5900 rad. Radiotherapeutic technique was a significant variable in local failure. Forty-six percent (6/13) of those patient failures may have been eliminated with the use of careful treatment planning with simulation. A statistically significant difference in dose was noted for patients with central recurrence, mean dose 4725 rad, 1561 RET, 81 TDF, when compared with patients with control of gross disease with radiation, mean dose 5740, 1880 RET, 108 TDF. There were four patients with marked early complications (6%) and eight patients with late complications (12%). There were no deaths attributable to radiation. Although most patients with advanced lung carcinoma die of distant disease, a significant number of patients can achieve long-term survival when radically treated with high-dose radiation therapy

  16. Observations of black carbon aerosols characteristics over an urban environment: Radiative forcing and related implications.

    Science.gov (United States)

    Bibi, Samina; Alam, Khan; Chishtie, Farrukh; Bibi, Humera; Rahman, Said

    2017-12-15

    With observations of black carbon (BC) aerosol concentrations, optical and radiative properties were obtained over the urban city of Karachi during the period of March 2006-December 2008. BC concentrations were continuously measured using an Aethalometer, while optical and radiative properties were estimated through the Optical Properties of Aerosols and Clouds (OPAC) and Santa Barbra DISORT Atmospheric Radiative Transfer (SBDART) models, respectively. For the study period, the measured BC concentrations were higher during January, February and November, while lower during May, June, July and August. A maximum peak value was observed during January 2007 while the minimum value was observed during June 2006. The Short Wave (SW) BC Aerosol Radiative Forcing (ARF) both at Top of the Atmosphere (ToA) and within ATMOSphere (ATMOS) were positive during all the months, whereas negative SW BC ARF was found at the SurFaCe (SFC). Overall, SW BC ARF was higher during January, February and November, while relatively lower ARF was found during May, June, July and August. Conversely, the Long Wave (LW) BC ARF at ToA and SFC remained positive, whereas within ATMOS it shifted towards positive values (heating effect) during June-August. Finally, the net (SW+LW) BC ARF were found to be positive at ToA and in ATMOS, while negative at SFC. Moreover, a systematic increase in Atmospheric Heating Rate (AHR) was found during October to January. Additionally, we found highest correlation between Absorption Aerosol Optical Depth (AOD abs ) and SW BC ARF within ATMOS followed by SFC and ToA. Overall, the contribution of BC to the total ARF was found to greater than 84% for the whole observational period while contributing up to 93% during January 2007. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. A case of radiation sigmoiditis diagnosed by a characteristic pathological finding

    International Nuclear Information System (INIS)

    Kamata, Noriko; Oshitani, Nobuhide; Oiso, Ryuta

    2002-01-01

    A 65-year-old woman was referred to our hospital because of an intractable sigmoid colon ulcer. She had undergone a right nephrectomy for kidney stones, at age 33, and a uterectomy at age 39, followed by radiation therapy. Lower abdominal pain and hematochezia developed suddenly, following a few days of constipation, in September 1999, when she was admitted to the previous hospital because of left hydronephrosis. A punched-out oval ulcer was found in the sigmoid colon, on colonoscopic examination. She was treated with total parenteral nutrition, prednisolone, and mesalazine administration. Although her hematochezia and abdominal pain disappeared, diarrhea and abdominal pain occurred after she began eating, and she was referred to our hospital for further examination. Although intestinal lavage solution was used for bowel preparation, stercoromas were found in the rectum, which had to be manually removed before colonoscopic examination, and a stercoral-ulcer was suspected. The sigmoid colonic ulcer was intractable. A biopsy specimen, taken from the bottom of the ulcer, revealed bizarre interstitial cells, each with a large oval nucleus, showing the so-called ''owl-eye-appearance.'' Although the diagnosis of radiation sigmoiditis is sometimes difficult, owl-eye-appearance'' is a useful pathological finding in the diagnosis of late-phase radiation-induced colitis. (author)

  18. Characteristic Investigation of Unfolded Neutron Spectra with Different Priori Information and Gamma Radiation Interference

    International Nuclear Information System (INIS)

    Kim, Bong Hwan

    2006-01-01

    Neutron field spectrometry using multi spheres such as Bonner Spheres (BS) has been almost essential in radiation protection dosimetry for a long time at workplace in spite of poor energy resolution because it is not asking the fine energy resolution but requiring easy operation and measurement performance over a wide range of energy interested. KAERI has developed and used extended BS system based on a LiI(Eu) scintillator as the representative neutron spectrometry system for workplace monitoring as well as for the quantification of neutron calibration fields such as those recommended by ISO 8529. Major topics in using BS are how close the unfolded spectra is the real one and to minimize the interference of gamma radiation in neutron/gamma mixed fields in case of active instrument such as a BS with a LiI(Eu) scintillator. The former is related with choosing a priori information when unfolding the measured data and the latter is depend on how to discriminate it in intense gamma radiation fields. Influence of a priori information in unfolding and effect of counting loss due to pile-up of signals for the KAERI BS system were investigated analyzing the spectral measurement results of Scattered Neutron Calibration Fields (SNCF)

  19. A case of radiation sigmoiditis diagnosed by a characteristic pathological finding

    Energy Technology Data Exchange (ETDEWEB)

    Kamata, Noriko; Oshitani, Nobuhide; Oiso, Ryuta [Osaka City Univ. (Japan). Graduate School of Medicine] (and others)

    2002-05-01

    A 65-year-old woman was referred to our hospital because of an intractable sigmoid colon ulcer. She had undergone a right nephrectomy for kidney stones, at age 33, and a uterectomy at age 39, followed by radiation therapy. Lower abdominal pain and hematochezia developed suddenly, following a few days of constipation, in September 1999, when she was admitted to the previous hospital because of left hydronephrosis. A punched-out oval ulcer was found in the sigmoid colon, on colonoscopic examination. She was treated with total parenteral nutrition, prednisolone, and mesalazine administration. Although her hematochezia and abdominal pain disappeared, diarrhea and abdominal pain occurred after she began eating, and she was referred to our hospital for further examination. Although intestinal lavage solution was used for bowel preparation, stercoromas were found in the rectum, which had to be manually removed before colonoscopic examination, and a stercoral-ulcer was suspected. The sigmoid colonic ulcer was intractable. A biopsy specimen, taken from the bottom of the ulcer, revealed bizarre interstitial cells, each with a large oval nucleus, showing the so-called ''owl-eye-appearance.'' Although the diagnosis of radiation sigmoiditis is sometimes difficult, owl-eye-appearance'' is a useful pathological finding in the diagnosis of late-phase radiation-induced colitis. (author)

  20. Microstructural characteristics of the hydroxyapatite and its influence in the Tl signal induced by gamma radiation

    International Nuclear Information System (INIS)

    Mendoza A, D.; Gonzalez M, P.R.; Hernandez A, M.; Estrada G, R.; Rodriguez L, V.

    2003-01-01

    The analysis carried out on different materials has shown that the quantity and type of dopants play an important role in the behaviour thermoluminescent signal induced by the ionizing radiation. More recent studies have also shown that the grain size influences strongly in the thermoluminescent signal. Plus still, the crystal growth habit and the crystalline degree have an important effect in the type and intensity thermoluminescent signal. In this sense, we present this work on the analysis of the thermoluminescent signal induced by the gamma radiation in the hydroxyapatite ceramic. Depending the growth habit, a variation of the peak temperature location, signal intensity and linearity range was observed; in particular cases a lineal relationship between glow curve and radiation dose was in the range from 2 to 1000 Gray. These results are complemented with a microstructural and crystalline degree analysis through scanning electron microscopy and X-ray Diffraction. The dose-response over the whole irradiation range opening up the possibility of employing this bio material as a dosimeter. (Author)

  1. Preparation and Characterization of UV Emitting Fluoride Phosphors for Phototherapy Lamps

    Science.gov (United States)

    Belsare, P. D.; Moharil, S. V.; Joshi, C. P.; Omanwar, S. K.

    2011-10-01

    The use of ultraviolet radiation for the treatment of various skin diseases is well known for long time. Phototherapy employs ultraviolet-blue radiation to cure skin diseases. The basis of phototherapy is believed to be the direct interaction of light of certain frequencies with tissue to cause a change in immune response. Currently dermatologists use UV lamps having specific emissions in UV region for treating various skin diseases. The treatment of skin diseases using artificial sources of UV radiation is now well established and more than 50 types of skin diseases are treated by phototherapy. This is an effective treatment for many skin disorders, such as psoriasis, vitiligo, ofujis disease, morphea , scleroderma, cutaneous T-cell lymphoma, lupus erythematosus, hyperbilirubinemia commonly known as infant jaundice, acne vulgaris, This paper reports photoluminescence properties of UV emitting fluoride phosphors prepared by wet chemical method. Emission characteristics of these phosphors are found similar to those of commercial UV lamp phosphors with comparable intensities. The usefulness of UV emitting fluoride phosphor is discussed in the paper.

  2. Thermoluminescence characteristics of different dimensions of Ge-doped optical fibers in radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Begum, M.; Mizanur R, A. K. M.; Abdul R, H. A.; Yusoff, Z. [Multimedia University, Faculty of Engineering, 63100 Cyberjaya, Selangor Darul Ehsan (Malaysia); Begum, M. [Bangladesh Atomic Energy Commission, E-12/A, Agargaon, Sher-e-Blanga Nagar Dhaka-1207 (Bangladesh); Mat-Sharif, K. A. [Lingkaran Teknokrat Timur, Telekom Research and Development, 63000 Cyberjaya, Selangor Darul Ehsan (Malaysia); Amin, Y. M. [University of Malaya, Faculty of Science, Depatment of Physics, 50603 Kuala Lumpur (Malaysia); Bradley, D. A., E-mail: go2munmun@yahoo.com [University of Surrey, Department of Physics, Guildford GU2 7XH (United Kingdom)

    2014-08-15

    Important thermoluminescence (Tl) properties of five (5) different core sizes Ge doped optical fibers have been studied to develop new Tl material with better response. These are drawn from same preform applying different speed and tension during drawing phase. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (Sem) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in SSDL (Secondary Standard Dosimetry Lab) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are Tl linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 grades C for 1 hour period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 hour at 400 grades C and subsequently 2 hours at 100 grades C to yield the highest sensitivity. Tl responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z{sub eff}) is found in the range (13.25 to 13.69) that is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. Tl properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry. (author)

  3. Thermoluminescence characteristics of different dimensions of Ge-doped optical fibers in radiation dosimetry

    International Nuclear Information System (INIS)

    Begum, M.; Mizanur R, A. K. M.; Abdul R, H. A.; Yusoff, Z.; Begum, M.; Mat-Sharif, K. A.; Amin, Y. M.; Bradley, D. A.

    2014-08-01

    Important thermoluminescence (Tl) properties of five (5) different core sizes Ge doped optical fibers have been studied to develop new Tl material with better response. These are drawn from same preform applying different speed and tension during drawing phase. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (Sem) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in SSDL (Secondary Standard Dosimetry Lab) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are Tl linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 grades C for 1 hour period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 hour at 400 grades C and subsequently 2 hours at 100 grades C to yield the highest sensitivity. Tl responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z eff ) is found in the range (13.25 to 13.69) that is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. Tl properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry. (author)

  4. Thermoluminescence characteristics of Ge-doped optical fibers with different dimensions for radiation dosimetry

    International Nuclear Information System (INIS)

    Begum, Mahfuza; Rahman, A.K.M. Mizanur; Abdul-Rashid, H.A.; Yusoff, Z.; Begum, Mahbuba; Mat-Sharif, K.A.; Amin, Y.M.; Bradley, D.A.

    2015-01-01

    Important thermoluminescence (TL) properties of five (5) different core sizes Ge-doped optical fibers have been studied to develop new TL material with better response. These are drawn from same preform applying different speed and tension during drawing phase to produce Ge-doped optical fibers with five (5) different core sizes. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge-doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (SEM) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in Secondary Standard Dosimetry Lab (SSDL) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are TL linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 °C for 1 h period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 h at 400 °C and subsequently 2 h at 100 °C to yield the highest sensitivity. TL responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z eff ) is found in the range (13.25–13.69) which is higher than soft tissue (7.5) however within the range of human-bone (11.6–13.8). All the fibers can also be re-used several times as a detector after annealing. TL properties of the Ge-doped optical fibers indicate promising applications in

  5. Assessing patient characteristics and radiation-induced non-targeted effects in vivo for high dose-rate (HDR) brachytherapy.

    Science.gov (United States)

    Pinho, Christine; Timotin, Emilia; Wong, Raimond; Sur, Ranjan K; Hayward, Joseph E; Farrell, Thomas J; Seymour, Colin; Mothersill, Carmel

    2015-01-01

    To test whether blood, urine, and tissue based colony-forming assays are a useful clinical detection tool for assessing fractionated treatment responses and non-targeted radiation effects in bystander cells. To assess patients' responses to radiation treatments, blood serum, urine, and an esophagus explant-based in vivo colony-forming assay were used from oesophageal carcinoma patients. These patients underwent three fractions of high dose rate (HDR) intraluminal brachytherapy (ILBT). Human keratinocyte reporters exposed to blood sera taken after the third fraction of brachytherapy had a significant increase in cloning efficiency compared to baseline samples (p fractions for the blood sera data only. Patient characteristics such as gender had no statistically significant effect (p > 0.05). Large variability was observed among the patients' tissue samples, these colony-forming assays showed no significant changes throughout fractionated brachytherapy (p > 0.05). Large inter-patient variability was found in the urine and tissue based assays, so these techniques were discontinued. However, the simple blood-based assay had much less variability. This technique may have future applications as a biological dosimeter to predict treatment outcome and assess non-targeted radiation effects.

  6. Detailed characteristics of radiation belt electrons revealed by CSSWE/REPTile measurements: Geomagnetic activity response and precipitation observation

    Science.gov (United States)

    Zhang, K.; Li, X.; Schiller, Q.; Gerhardt, D.; Zhao, H.; Millan, R.

    2017-08-01

    Earth's outer radiation belt electrons are highly dynamic. We study the detailed characteristics of relativistic electrons in the outer belt using measurements from the Colorado Student Space Weather Experiment (CSSWE) mission, a low Earth orbit (LEO) CubeSat, which traverses the radiation belt four times in one orbit ( 1.5 h) and has the advantage of measuring the dynamic activities of the electrons including their rapid precipitation. We focus on the measured electron response to geomagnetic activity for different energies to show that there are abundant sub-MeV electrons in the inner belt and slot region. These electrons are further enhanced during active times, while there is a lack of >1.63 MeV electrons in these regions. We also show that the variation of measured electron flux at LEO is strongly dependent on the local magnetic field strength, which is far from a dipole approximation. Moreover, a specific precipitation band, which happened on 19 January 2013, is investigated based on the conjunctive measurement of CSSWE, the Balloon Array for Radiation belt Relativistic Electron Losses, and one of the Polar Operational Environmental Satellites. In this precipitation band event, the net loss of the 0.58-1.63 MeV electrons (L = 3.5-6) is estimated to account for 6.8% of the total electron content.

  7. Gamma Radiation Influence on Rheological and Technological Characteristics of Wheat Flour (misr-1) and Sensory Properties of Pan Bread

    International Nuclear Information System (INIS)

    Anwar, M.M.; Asael, M.A.; El-Adly, N.A.

    2015-01-01

    This study aimed at determining the influence of gamma radiation on rheological and technological characteristics of flour extraction from irradiated wheat grains (misr-1) with 3,6 and 9 kGy, also baking quality and sensory characteristics of pan breads made from this flour. The rheological properties of wheat flour 72% extraction were determined by farinograph parameter, extensograph parameter and measured by amylo graph paramete. Gamma radiation caused increase in water absorption and decrease dough development time, and dough stability time. The decrease percentage increased by increasing dose rate and increased the dough weakness, also γ-irradiation increased the elasticity, decrease extensibility and decrease dough strength (energy), whereas γ-irradiation on wheat grains (misr-1) decrease the maximum viscosity of flour, it indicate an increase in enzymatic activity as a result of the breakdown of starch and improve the gluten index %, this fact is beneficial for bread baking purposes. So γ-irradiation increased volume loaf especially at the dose 6 kGy,and no real differences of taste, texture, appearance and odor scores for sensory evaluation of pan bread made of flour extraction from irradiated and un-irradiated wheat grains. Mean while, irradiation particularly at higher doses (6 and 9 kGy)caused difference in the color (darkness) of pan bread. Gamma irradiation increased the baking quality, and improvement volume loaf especially at the dose 6 kGy.

  8. Radiations

    International Nuclear Information System (INIS)

    Pujol Mora, J.

    1999-01-01

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

  9. Radiation

    International Nuclear Information System (INIS)

    Davidson, J.H.

    1986-01-01

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

  10. Gamma radiation influence in physical and chemical characteristics of Bacaba Oil (Oenocarpus bacaba Mart.)

    International Nuclear Information System (INIS)

    Fonseca, Hugo Maia; Santos, Camila Oliveira dos; Cruz, Luis Paulo Adami; Arthur, Valter; Souza, Adriana Regia Marques de

    2015-01-01

    The bacaba (Oenocarpus bacaba Mart.) is a fruit originating from the Amazon forest, and its oil has similarity to the fatty acid composition of olive oil. The objective of this study was to evaluate the quality of bacaba oil submitted to gamma radiation in the of 5, 10 and 15 kGy. The extracted oil was irradiated at doses of 5, 10 and 15 kGy, and then the physical and chemical analysis were carried out: acid value, peroxide value, iodine value, refractive index, specific gravity, saponification value, coefficient specific extinction at 232 and 270 nm and color. Was possible to evidence that radiation promoted decrease in acidity of the oil 26.67%, 27.27% and 9.09%, respectively, at the doses of 5, 10 and 15 kGy, in relation to oil which has not gone through the process (standard). The values of specific gravity, refractive index and saponification value, have not changed, but the result of peroxides were significantly affected, increasing by 51.99%, 100.44% and 89.40% values relative to the standard. It was also observed a significant increase in K232 and K270 values, suggesting increased oxidation products, conjugated dienes and trienes. The oil color has been affected by the doses, generating a product with a more yellowish color and increased brightness. That way, from the analysis, it concluded that the use of gamma radiation at the doses used were not sufficient to make it, in the short term, unsafe for consumption, but changed substantially oil color. (author)

  11. Gamma radiation influence in physical and chemical characteristics of Bacaba Oil (Oenocarpus bacaba Mart.)

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Hugo Maia; Santos, Camila Oliveira dos; Cruz, Luis Paulo Adami, E-mail: hmaiaf@gmail.com [Universidade Federal do Tocantins (UFT), Palmas, TO (Brazil); Arthur, Valter, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia; Souza, Adriana Regia Marques de, E-mail: adriana.souza@pq.cnpq.br [Universidade Federal de Goias (UFGO), Goiania, GO (Brazil). Escola de Agronomia

    2015-07-01

    The bacaba (Oenocarpus bacaba Mart.) is a fruit originating from the Amazon forest, and its oil has similarity to the fatty acid composition of olive oil. The objective of this study was to evaluate the quality of bacaba oil submitted to gamma radiation in the of 5, 10 and 15 kGy. The extracted oil was irradiated at doses of 5, 10 and 15 kGy, and then the physical and chemical analysis were carried out: acid value, peroxide value, iodine value, refractive index, specific gravity, saponification value, coefficient specific extinction at 232 and 270 nm and color. Was possible to evidence that radiation promoted decrease in acidity of the oil 26.67%, 27.27% and 9.09%, respectively, at the doses of 5, 10 and 15 kGy, in relation to oil which has not gone through the process (standard). The values of specific gravity, refractive index and saponification value, have not changed, but the result of peroxides were significantly affected, increasing by 51.99%, 100.44% and 89.40% values relative to the standard. It was also observed a significant increase in K232 and K270 values, suggesting increased oxidation products, conjugated dienes and trienes. The oil color has been affected by the doses, generating a product with a more yellowish color and increased brightness. That way, from the analysis, it concluded that the use of gamma radiation at the doses used were not sufficient to make it, in the short term, unsafe for consumption, but changed substantially oil color. (author)

  12. Dynamic characteristics of far-field radiation of current modulated phase-locked diode laser arrays

    Science.gov (United States)

    Elliott, R. A.; Hartnett, K.

    1987-01-01

    A versatile and powerful streak camera/frame grabber system for studying the evolution of the near and far field radiation patterns of diode lasers was assembled and tested. Software needed to analyze and display the data acquired with the steak camera/frame grabber system was written and the total package used to record and perform preliminary analyses on the behavior of two types of laser, a ten emitter gain guided array and a flared waveguide Y-coupled array. Examples of the information which can be gathered with this system are presented.

  13. Effect of gamma radiation on physico-chemical characteristics of red gram (Cajanus cajan) starch

    International Nuclear Information System (INIS)

    Nene, S.P.; Vakil, U.K.; Sreenivasan, A.

    1975-01-01

    Total reducing and nonreducing sugars in red gram (Cajanus cajan) are not affected by radiation treatment (1 Mrad). Oligosaccharides, reported as flatulence factors in legumes, namely stachyose and raffinose, are slightly decreased on cooking the irradiated samples. Irradiated and cooked red gram starch is more susceptible to alpha-amylase action than the unirradiated sample. Rheological properties of red gram starch, such as gelatinization viscosity, swelling power and solubility improve on irradiation resulting in a final cooked product with better textural properties. (U.S.)

  14. Near-field characteristics of radiating-wave simulator antenna based on TEM horn

    International Nuclear Information System (INIS)

    Tian Chunming; Ge Debiao

    2004-01-01

    This paper presents a novel antenna of NEMP (nuclear electromagnetic pulse) radiating-wave simulator, which is analyzed and optimized using the finite-difference time domain (FDTD) method. The intense voltage pulse is fed as the source to this antenna by the coaxial line. The parallel plate transmission line and the size of the transverse electromagnetic horn are optimized. The near field of antenna is analyzed, and the effects of the size on the near field are also given. The antenna designed in this paper can well satisfy the requirement for studying the EMP effects

  15. Influence of Selected Parameters of XeCl Excimer Laser System on Characteristics of Radiation Pulses

    International Nuclear Information System (INIS)

    Pokora, L.; Iwanejko, L.

    1998-01-01

    We present the dependences of energy and duration of radiation pulses as well as efficiency of XeCl laser on selected parameters of the laser system such as: C 2 capacitance, the separating inductance, L S , the distance between electrodes in laser's chamber, d K and also the supply voltage, U 0 , composition, and pressure of the active-medium mixture of gases. Results of numerical computations relate to a three-component mixture of gases, He-Xe-HCl, of the active medium of the excimer laser. (author)

  16. Exponential characteristics spatial quadrature for discrete ordinates radiation transport in slab geometry

    International Nuclear Information System (INIS)

    Mathews, K.; Sjoden, G.; Minor, B.

    1994-01-01

    The exponential characteristic spatial quadrature for discrete ordinates neutral particle transport in slab geometry is derived and compared with current methods. It is similar to the linear characteristic (or, in slab geometry, the linear nodal) quadrature but differs by assuming an exponential distribution of the scattering source within each cell, S(x) = a exp(bx), whose parameters are root-solved to match the known (from the previous iteration) average and first moment of the source over the cell. Like the linear adaptive method, the exponential characteristic method is positive and nonlinear but more accurate and more readily extended to other cell shapes. The nonlinearity has not interfered with convergence. The authors introduce the ''exponential moment functions,'' a generalization of the functions used by Walters in the linear nodal method, and use them to avoid numerical ill-conditioning. The method exhibits O(Δx 4 ) truncation error on fine enough meshes; the error is insensitive to mesh size for coarse meshes. In a shielding problem, it is accurate to 10% using 16-mfp-thick cells; conventional methods err by 8 to 15 orders of magnitude. The exponential characteristic method is computationally more costly per cell than current methods but can be accurate with very thick cells, leading to increased computational efficiency on appropriate problems

  17. Radiation

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  18. Application of LiF for determining the gamma-radiation characteristics of the shut-down reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ibragimova, E M; Musaeva, M A; Ashrapov, U T; Kalanov, M U; Muminov, M I [Inst. of Nuclear Physics, Tashkent (Uzbekistan)

    2005-07-01

    Full text: The power of {sup 60}Co {approx}1.25 MeV gamma-radiation source at the INP AS RUz is limited by 8 Gy/s, which does not satisfy several tasks of material science now. Therefore, we were first to suggest the irradiation of materials with gamma-rays of 0.1-7 MeV, which are emitted by the uranium fission products ({sup 41}Ar, {sup 135}Xe, {sup 125}Xe, {sup 125}I,{sup 137}Cs, {sup 134}Cs, {sup 144}Ce, {sup 95}Zr, {sup 140}Ba, {sup 140}La, {sup 99}Mo, {sup 60}Co) and {sup l6}N, {sup 24}Na, {sup 28}Al radio-nuclides in water during prophylactic shut-downs of our nuclear reactor WWR-SM. The gamma-dose rate kinetics was monitored with the ion current in ionization chambers KNK-53M fixed outside the reactor core from the stop-moment. The current kinetics comprised 4 steps with a high reproducibility at 2 and 0.5 {mu}A, then 50 and 10 nA, each lasting for 1,10, 40 and up to 200 hours, according to the isotope life-times. LiF crystal is known as a thermal luminescence dosimeter of mixed radiations up to 100 Gy. Yet in this work the absorbed gamma-energy dose D{sub {gamma}} was determined by accumulation of the known stable structure defects in thin cleaved LiF crystals: by induced optical absorption and luminescence of F- and M-centers. The samples were irradiated in Al-containers filled with water to keep the temperature of {approx}40 deg. C in the time range from 30 minutes to 150 hours. Optical absorption spectra were registered at spectrometer Specord M-40. Then the induced color center concentration was calculated by the Smakula relation, which is proportional to the absorbed dose D{gamma}. For a better reliability the photoluminescence center content was also determined. Selecting comparable close intensities of the induced absorption and luminescence bands obtained after irradiations of LiF references in the certified {sup 60}Co gamma-sources of the known gamma fluxes 0.7 and 7.5 Gy/s, the gamma-radiation intensity of the shut-down reactor was estimated in

  19. Application of LiF for determining the gamma-radiation characteristics of the shut-down reactor

    International Nuclear Information System (INIS)

    Ibragimova, E.M.; Musaeva, M.A.; Ashrapov, U.T.; Kalanov, M.U.; Muminov, M.I.

    2005-01-01

    Full text: The power of 60 Co ∼1.25 MeV gamma-radiation source at the INP AS RUz is limited by 8 Gy/s, which does not satisfy several tasks of material science now. Therefore, we were first to suggest the irradiation of materials with gamma-rays of 0.1-7 MeV, which are emitted by the uranium fission products ( 41 Ar, 135 Xe, 125 Xe, 125 I, 137 Cs, 134 Cs, 144 Ce, 95 Zr, 140 Ba, 140 La, 99 Mo, 60 Co) and l6 N, 24 Na, 28 Al radio-nuclides in water during prophylactic shut-downs of our nuclear reactor WWR-SM. The gamma-dose rate kinetics was monitored with the ion current in ionization chambers KNK-53M fixed outside the reactor core from the stop-moment. The current kinetics comprised 4 steps with a high reproducibility at 2 and 0.5 μA, then 50 and 10 nA, each lasting for 1,10, 40 and up to 200 hours, according to the isotope life-times. LiF crystal is known as a thermal luminescence dosimeter of mixed radiations up to 100 Gy. Yet in this work the absorbed gamma-energy dose D γ was determined by accumulation of the known stable structure defects in thin cleaved LiF crystals: by induced optical absorption and luminescence of F- and M-centers. The samples were irradiated in Al-containers filled with water to keep the temperature of ∼40 deg. C in the time range from 30 minutes to 150 hours. Optical absorption spectra were registered at spectrometer Specord M-40. Then the induced color center concentration was calculated by the Smakula relation, which is proportional to the absorbed dose Dγ. For a better reliability the photoluminescence center content was also determined. Selecting comparable close intensities of the induced absorption and luminescence bands obtained after irradiations of LiF references in the certified 60 Co gamma-sources of the known gamma fluxes 0.7 and 7.5 Gy/s, the gamma-radiation intensity of the shut-down reactor was estimated in correlation with the ion current as 10 nA = 15 Gy/s. At short times of irradiation the linear dose dependence

  20. Act of 21 February 1963, Stb. 82, concerning the release of nuclear energy and the use of radioactive materials and of devices emitting ionizing radiations (Nuclear Energy Act) as amended by the Act of 30 June 1967, Stb. 337, and the Act of 8 May 1974, Stb. 291

    International Nuclear Information System (INIS)

    1963-01-01

    This basic Act governs all nuclear activities in the Netherlands and determines the Government's competence and the obligations of those involved in the nuclear field. It establishes definitions and sets up bodies to advise the Government in the different nuclear sectors and covers nuclear installations, fissionable materials, ores, radioactive materials, radiation-emitting devices and their licensing. It was brought into force progressively by decrees made in implementation of its provisions, which lay down detailed regulations for the activity concerned. The chapters of the Act not yet in force were brought into operation on 1 January 1970 by the Nuclear Energy Act (Implantation) Decree of 12 November 1969. (NEA) [fr

  1. Development of special radiation shielding concretes using natural local materials and evaluation of their shielding characteristics

    International Nuclear Information System (INIS)

    Kharita, M. H.; Takeyeddin, M.; Al-Nassri, M.; Yousef, S.

    2008-01-01

    Concrete is one of the most important materials used for radiation shielding in facilities containing radioactive sources and radiation generating machines. The concrete shielding properties may vary depending on the composite of the concrete. Aggregates is the largest constituent (about 70-80% of the total weight of normal concrete). The aim of this work is to develop special concrete with good shielding properties for gamma and neutrons, using natural local materials. For this reason two types of typical concrete widely used in Syria (in Damascus and Aleppo) and four other types of concrete, using aggregates from different regions, have been prepared. The shielding properties of these six types were studied for gamma ray (from Cs-137 and Co-60 sources)and for neutrons (from am-Be source). A reduction of about 10% in the HVL was obtained for the concrete from Damascus in comparison with that from Aleppo, for both neutrons and gammas. One of the other four types of concrete (from Rajo site, mostly Hematite), was found to further reduce the HVL by about 10% for both neutrons and gamma rays.(author)

  2. Using natural local materials for developing special radiation shielding concretes, and deduction of its shielding characteristics

    International Nuclear Information System (INIS)

    Kharita, M. H.; Takeyeddin, M.; Al-Nassar, M.; Yousef, S.

    2006-06-01

    Concrete is considered as the most important material to be used for radiation shielding in facilities contain radioactive sources and radiation generating machines. The concrete shielding properties may vary depending on the construction of the concrete, which is highly relative to the composing aggregates i.e. aggregates consist about 70 - 80% of the total weight of normal concrete. In this project tow types of concrete used in Syria (in Damascus and Aleppo) had been studied and their shielding properties were defined for gamma ray from Cs-137 and Co-60 sources, and for neutrons from Am-Be source. About 10% reduction in HVL was found in the comparison between the tow concrete types for both neutrons and gammas. Some other types of concrete were studied using aggregates from different regions in Syria, to improve the shielding properties of concrete, and another 10% of reduction was achieved in comparison with Damascene concrete (20% in comparison with the concrete from Aleppo) for both neutrons and gamma rays. (author)

  3. Study of Textile Surface Characteristic Modification by Using Electron Beam Radiation

    International Nuclear Information System (INIS)

    Iswani Gitawati; Rany Saptaaji

    2007-01-01

    The success of accelerator technology application in various field of industry, medical and pharmacy, environment, agricultural, food increase each year as the increasing of people needs, not excepted for surface treatment of fibers and textiles in textile industry. This writing aim is to asses the application of electron beam accelerator for textile surface treatment on finishing step. Surface treatment was done with electron beam low energy (100 - 500 keV), and because of its low penetration it was suitable used to gain the improvement of chemical, physical and mechanical properties of textile surface such as adhesion, wettability, printability, dyes-intake, crease recovery, wrinkle-resistance, flammability, abrasion resistance, soil and stain release to get better result. Modification of fibers and textiles surface properties on finishing process can be caused by crosslinking, grafting and degradation reactions. The assesment results showed that the greatest impact on commercial application of radiation in textiles were crease recovery and surface modification of wetting properties (soil and stain release). The radiation dose used for those purposes were 5 - 50 kGy. The bach process of graft textiles surface modification before and after irradiation by Co-60 source (gamma energies of 1.33 and 1.17 MeV) and continue process by electron beam were presented. The assesment results were reported in this paper. (author)

  4. Development and Performance Characteristics of Personal Gamma Spectrometer for Radiation Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Hye Min Park

    2016-06-01

    Full Text Available In this study, a personal gamma (γ spectrometer was developed for use in applications in various fields, such as homeland security and environmental radiation monitoring systems. The prototype consisted of a 3 × 3 × 20 mm3 Ce-doped Gd–Al–Ga–garnet (Ce:GAGG crystal that was coupled to a Si photomultiplier (SiPM to measure γ radiation. The γ spectrometer could be accessed remotely via a mobile device. At room temperature, the implemented Ce:GAGG-SiPM spectrometer achieved energy resolutions of 13.5%, 6.9%, 5.8%, and 2.3% for 133Ba at 0.356 MeV, 22Na at 0.511 MeV, 137Cs at 0.662 MeV, and 60Co at 1.33 MeV, respectively. It consumed only about 2.7 W of power, had a mass of just 340 g (including the battery, and measured only 5.0 × 7.0 cm2.

  5. Effect of ultrasonic radiation on some physical characteristics of broiler breast muscle and cooked meat

    International Nuclear Information System (INIS)

    Dickens, J.A.; Lyon, C.E.; Wilson, R.L.

    1991-01-01

    A study was conducted to determine the effect of ultrasonic radiation on the muscle fibers of broiler breast muscle and the objective texture of the cooked meat. Seventy commercially processed broiler carcasses were subjected to either a 15-min water control or ultrasonic bath (40 kHz at 2,400-W power input). Carcasses were then bagged and placed in a 2 C cooling chamber until 2-h post-mortem (PM) at which time both pectoralis major muscles were excised and weighed. At 24 h PM the muscles were heated for 30 min at 85 C, then cooled for 30 min. The meat and the resulting fluids lost during heating were weighed; two 1.27-cm wide strips were removed from each breast, and analyzed for shear values. Samples for histological evaluation were taken at both 2 and 24 h PM and showed no treatment differences. The effect of ultrasonic radiation on carcass temperature was analyzed; untreated carcasses were found to be 3 C lower than treated carcasses. There were no treatment differences in fluids lost, but shear values of the ultrasound-treated meat were significantly less (P<.05) than the shear values of the water control: 4.4 and 5.0 kg, respectively

  6. House characteristics associated with gamma radiation and radon daughter working levels in eastern Pennsylvania

    International Nuclear Information System (INIS)

    Stebbings, J.H.; Dignam, J.J.; Anast, G.A.; Reilly, M.A.; Gerusky, T.M.; Hartman, T.T.

    1988-01-01

    Working levels (WL) of radon daughters and γ measurements in basements are described for ∼ 1200 houses near the Reading Prong. House variables included condition and construction materials of basement floors and walls, basement heights and areas, heating systems, air conditioning, water supply, and presence of drains and sump pumps. WLs were poorly predicted by house characteristics or γ measurements, while γ levels were well predicted by house characteristics and WL. Factors predicting high γ levels tended to be associated with low WLs and vice versa. Dirt basement floors and fieldstone basement walls were strongly associated with high γ levels, as were poor wall conditions in multivariate analyses. Gamma levels were low in electrically heated homes. High WLs were strongly associated with electric heat, low WLs with basement walls of fieldstone and/or in poor condition. Large house volumes and well water supply were also associated with higher WLs. (author)

  7. The characteristics of CaF2:Tm crystals (TLD-300) irradiated by electromagnetic radiation

    International Nuclear Information System (INIS)

    Ben-Shachar, B.; Yona, S.; Laichter, Y.; German, U.; Weiser, G.

    1985-09-01

    The main characteristics of the CaF 2 :Tm crystals (TLD-300), as a dosimeter, were measured: the glow curve, sensitivity, linearity, fading and energy dependence for photons, and compared to those of LiF (TLD-100) and CaF 2 :Dy (TLD-200). It was found that CaF 2 :Tm can be used for environmental dosimetry by reading the crystals after four days. (Author)

  8. Positron emitting pharmaceuticals

    International Nuclear Information System (INIS)

    Rajan, M.G.R.

    2012-01-01

    Positron Emission Tomography (PET) imaging of physiology at the molecular level bridges the gap between laboratory science and clinical medicine by providing the most specific and sensitive means for imaging molecular pathways and interactions in tissues of man. PET-imaging requires the use Positron Emitting Radiopharmaceuticals (PRPs), which are radioactively labeled 'true metabolites' i.e., sugars, amino acids, fatty acids etc., essentially made of H, C, N and O which the cells in the body can metabolize. The PET-isotopes: 11 C, 15 O, 13 N and 18 F (instead of H) are cyclotron produced and are short-lived, which places several constraints on the synthesis time for the PRPs, quality control and their clinical use as compared to the conventional 99m Tc- and other SPECT-RPs widely used in nuclear medicine. There are large number of published reports showing the utility of several PRPs labeled with 18 F (T 1/2 = 110 min) and 11 C (T 1/2 = 20 min). A few PRPs have been labeled with 13 N (T 1/2 = 10 min). 15 O (T 1/2 = 2min) is used mostly as H 2 15 O, C 15 or C 15 O 2 . 18 F-radiopharmaceuticals can be made at a medical cyclotron facility and sent to PET -imaging centres, which can be reached in a couple of hours. The sensitivity of PET -imaging has encouraged R and D in several other PRPs, labeled with viz., 68 Ga (generator produced, T 1/2 68 min), 124 I (cyclotron, T 1/2 4.2 d), 82 Rb (generator, T 1/2 75s), 64 Cu (cyclotron, T 1/2 12h), and 94m Tc (cyclotron, T 1/2 52 min). Due to its relevance in several diseases, particularly cancer, PET-imaging has made major scientific contribution to drug development, particularly for neurological diseases and cancer treatment. (author)

  9. Action of gamma radiation in the physico-chemical and sensorial characteristics of minimally processed cassava (Manihot esculenta CRANTZ)

    International Nuclear Information System (INIS)

    Simioni, Karime Raya

    2001-01-01

    Nowadays irradiation has been the most studied method of food conservation. The publication of thousand of papers, not just scientific but also technological, economical and social, have proved the technical validity of the irradiation method and showed the ways of how to introduce it in commercial facilities in ali countries of the modem world. Cassava is cultivated almost ali over the world and it is considered one of the most important nutritious sources of calories in human diet. Cassava is a viable food against starving in several poor areas of the world because it is an extremely resistant culture and may reach satisfactory economical yield. Cassava is a quite perishable root, characterized by fast post harvest deterioration. Because of the lack of researches about the effects of radiations in this root, the objective of the present work was to examine the gamma radiation coming from 60 Cobalt as a treatment to prolong the shelflife of the root after harvesting, aiming to increase its period of commercialization and to conserve its sensorial characteristics for a longer period. Samples were washed, peeled, cleaned and diced cassava roots packed in polyethylene bags. The treatments were: control; freezing and storage at 18 deg C for 21 days; and irradiation with the doses of 8 and 10 kGy. The control and the irradiated samples were stored under ambient temperature during 21 days. All samples were analyzed at each 7 days for alterations in the physicochemical and sensorial characteristics. The samples were analyzed for pH, acidity, weight, humidity, texture and color. The irradiation did not affect the chemical characteristics of the cassava. Neither the pH nor the acidity, the most relevant variables to verify deterioration in cassava, presented significant alterations during the period of storage. Comparing the irradiated treatments, the dose of 8 kGy was that less affected the physic-chemical characteristics of the cassava and scored the highest notes in the

  10. Something new: a new approach to correcting theoretical emitted intensities for absorption effects

    International Nuclear Information System (INIS)

    Willis, J.P.; Lachance, G.R.

    2002-01-01

    Full text: For monochromatic incident radiation of wavelength λ, absorption only (no enhancement), and ignoring such effects as the absorption edge jump ratio, the fluorescence yield, and the probability that a Kα line will be emitted instead of a Kβ line, a simplified view of the theoretical emitted intensity of a characteristic line of element >i= from a layer in a specimen is given by a familiar equation which involves mass absorption coefficients. While this equation allows for the calculation of the theoretical emitted intensity, it is cumbersome to use when trying to explain X-ray excitation in a step-wise manner. It is therefore proposed that the mass attenuation coefficients (μ iλ , and the sum of μ sλ ' + μ sλi '' , in the numerator and denominator of this equation be replaced by the product of two coefficients correcting for absorption, namely aN H aO. The advantages of using the proposed equation in the stepwise calculation of theoretical intensities (in a similar manner to Monte Carlo calculations) will be discussed. Copyright (2002) Australian X-ray Analytical Association Inc

  11. Analysis of angular momentum properties of photons emitted in fundamental atomic processes

    Science.gov (United States)

    Zaytsev, V. A.; Surzhykov, A. S.; Shabaev, V. M.; Stöhlker, Th.

    2018-04-01

    Many atomic processes result in the emission of photons. Analysis of the properties of emitted photons, such as energy and angular distribution as well as polarization, is regarded as a powerful tool for gaining more insight into the physics of corresponding processes. Another characteristic of light is the projection of its angular momentum upon propagation direction. This property has attracted a special attention over the past decades due to studies of twisted (or vortex) light beams. Measurements being sensitive to this projection may provide valuable information about the role of angular momentum in the fundamental atomic processes. Here we describe a simple theoretical method for determination of the angular momentum properties of the photons emitted in various atomic processes. This method is based on the evaluation of expectation value of the total angular momentum projection operator. To illustrate the method, we apply it to the textbook examples of plane-wave, spherical-wave, and Bessel light. Moreover, we investigate the projection of angular momentum for the photons emitted in the process of the radiative recombination with ionic targets. It is found that the recombination photons do carry a nonzero projection of the orbital angular momentum.

  12. Solar wind radiation damage in lunar dust grains and the characteristics of the ancient solar wind

    International Nuclear Information System (INIS)

    Borg, J.; Chaumont, J.

    1980-01-01

    Current understanding of the exposure history of lunar dust grains to the ancient solar wind is reviewed, the work being based mostly on a Monte Carlo statistical code, describing the 'gardening' effects of the meteorite bombardment in the lunar regolith, and on analytical models, yielding the lifetimes of the grains against various types of destruction processes. Families of lunar dust grains are identified, and evidence is presented showing that lunar dust grains were not partially shielded from solar wind ions. Results of solar wind simulation experiments are used to interpret the thickness distribution of the amorphous coatings of solar wind radiation-damaged material observed on 1-micron lunar dust grains. It is argued that such distributions reflect the speed distribution of the ancient solar wind as averaged over periods of approximately 5000 years in duration, and that the ancient solar wind is less energetic than the present day solar wind

  13. Radiation-Induced Organizing Pneumonia: A Characteristic Disease that Requires Symptom-Oriented Management.

    Science.gov (United States)

    Otani, Keisuke; Seo, Yuji; Ogawa, Kazuhiko

    2017-01-27

    Radiation-induced organizing pneumonia (RIOP) is an inflammatory lung disease that is occasionally observed after irradiation to the breast. It is a type of secondary organizing pneumonia that is characterized by infiltrates outside the irradiated volume that are sometimes migratory. Corticosteroids work acutely, but relapse of pneumonia is often experienced. Management of RIOP should simply be symptom-oriented, and the use of corticosteroids should be limited to severe symptoms from the perspective not only of cost-effectiveness but also of cancer treatment. Once steroid therapy is started, it takes a long time to stop it due to frequent relapses. We review RIOP from the perspective of its diagnosis, epidemiology, molecular pathogenesis, and patient management.

  14. Powerful infrared emitting diodes

    Directory of Open Access Journals (Sweden)

    Kogan L. M.

    2012-02-01

    Full Text Available Powerful infrared LEDs with emission wavelength 805 ± 10, 870 ± 20 and 940 ± 10 nm developed at SPC OED "OPTEL" are presented in the article. The radiant intensity of beam diode is under 4 W/sr in the continuous mode and under 100 W/sr in the pulse mode. The radiation power of wide-angle LEDs reaches 1 W in continuous mode. The external quantum efficiency of emission IR diodes runs up to 30%. There also has been created infrared diode modules with a block of flat Fresnel lenses with radiant intensity under 70 W/sr.

  15. Exponential characteristic spatial quadrature for discrete ordinates radiation transport with rectangular cells

    International Nuclear Information System (INIS)

    Minor, B.; Mathews, K.

    1995-01-01

    The exponential characteristic (EC) spatial quadrature for discrete ordinates neutral particle transport previously introduced in slab geometry is extended here to x-y geometry with rectangular cells. The method is derived and compared with current methods. It is similar to the linear characteristic (LC) quadrature (a linear-linear moments method) but differs by assuming an exponential distribution of the scattering source within each cell, S(x) = a exp(bx + cy), whose parameters are rootsolved to match the known (from the previous iteration) spatial average and first moments of the source over the cell. Similarly, EC assumes exponential distributions of flux along cell edges through which particles enter the cell, with parameters chosen to match the average and first moments of flux, as passed from the adjacent, upstream cells (or as determined by boundary conditions). Like the linear adaptive (LA) method, EC is positive and nonlinear. It is more accurate than LA and does not require subdivision of cells. The nonlinearity has not interfered with convergence. The exponential moment functions, which were introduced with the slab geometry method, are extended to arbitrary dimensions (numbers of arguments) and used to avoid numerical ill conditioning. As in slab geometry, the method approaches O(Δx 4 ) global truncation error on fine-enough meshes, while the error is insensitive to mesh size for coarse meshes. Performance of the method is compared with that of the step characteristic, LC, linear nodal, step adaptive, and LA schemes. The EC method is a strong performer with scattering ratios ranging from 0 to 0.9 (the range tested), particularly so for lower scattering ratios. As in slab geometry, EC is computationally more costly per cell than current methods but can be accurate with very thick cells, leading to increased computational efficiency on appropriate problems

  16. Characteristics of postharvest quality in regional fruits treate with ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Josenilda M.; Villar, Heldio P. [Centro Regional de Ciencias Nucleares (CRCN/CNEN-NE), Recife, PE (Brazil)], e-mail: jmnilda@cnen.gov.br; Correia, Lidia C.S.A.; Maciel, Maria Ines S. [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil)], e-mail: aidil_alencar@yahoo.com.br, e-mail: marines@ufrpe.br

    2009-07-01

    In order to investigate the effects of irradiation on the main characteristics of quality postharvest of three cultivated species of the Northeast Region of Brazil, experiments with cashew (Anacardium occidentale L. var. Nanum), sapodilla (Manilkara sapodilla (L) Van Royen) and mangaba (Hancornia speciosa Gomes) have been performed. Cashew peduncles stored for fourteen days under 6.5 deg C had presented best results in the sensorial analyses for external appearance, flavour and aroma when irradiated with 1 kGy. sapodillas irradiated with doses of 300, 600 and 900 Gy have not displayed harmed sensorial qualities when stored under 20 deg C during twelve days. Doses up to 800 Gy had not harmed the external and internal appearance of mangabas after being stored for a fortnight under 13 deg C. Chemical characteristics of TSS, TTA, pH and solid/acidity ratio have not been affected significantly by the different doses applied to the three studied species. Amount of ascorbic acid was lower in the irradiated fruits, with significant differences for the species Anacardium occidentale L. var. Nanum and Hancornia speciosa Gomes. (author)

  17. House characteristics associated with gamma radiation and radon daughter working levels in eastern Pennsylvania

    International Nuclear Information System (INIS)

    Stebbings, J.H.; Dignam, J.J.; Reilly, M.A.; Gerusky, T.M.; Hartman, T.T.; Anast, G.A.

    1987-01-01

    Working levels (WL) of radon daughters and γ measurements in basements are described for ∼1200 houses near the Reading Prong. House variables studied included condition and construction materials of basement floors and walls, basement heights and areas, heating systems, air conditioning, water supply, and presence of drains and sump pumps. WL's were poorly predicted by house characteristics or γ measurements, while γ levels were well predicted by house characteristics and WL. Except for windowless basements, associated with both high γ andl high WL measurements, factors predicting high γ levels tended to be associated with low WL's and vice versa. Dirt basement floors and fieldstone basement walls were strongly associated with high γ levels, as were poor wall conditions in multivariate analyses. Gamma levels were low in electrically heated homes. High WL's were strongly associated with electric heat, low WL's with basement walls of fieldstone and/or in poor condition. Large house volumes and well water supply were also associated with higher WL's. 4 refs., 1 fig., 4 tabs

  18. Characteristics of postharvest quality in regional fruits treate with ionizing radiation

    International Nuclear Information System (INIS)

    Silva, Josenilda M.; Villar, Heldio P.; Correia, Lidia C.S.A.; Maciel, Maria Ines S.

    2009-01-01

    In order to investigate the effects of irradiation on the main characteristics of quality postharvest of three cultivated species of the Northeast Region of Brazil, experiments with cashew (Anacardium occidentale L. var. Nanum), sapodilla (Manilkara sapodilla (L) Van Royen) and mangaba (Hancornia speciosa Gomes) have been performed. Cashew peduncles stored for fourteen days under 6.5 deg C had presented best results in the sensorial analyses for external appearance, flavour and aroma when irradiated with 1 kGy. sapodillas irradiated with doses of 300, 600 and 900 Gy have not displayed harmed sensorial qualities when stored under 20 deg C during twelve days. Doses up to 800 Gy had not harmed the external and internal appearance of mangabas after being stored for a fortnight under 13 deg C. Chemical characteristics of TSS, TTA, pH and solid/acidity ratio have not been affected significantly by the different doses applied to the three studied species. Amount of ascorbic acid was lower in the irradiated fruits, with significant differences for the species Anacardium occidentale L. var. Nanum and Hancornia speciosa Gomes. (author)

  19. Effects of gamma radiation on sprouting turmeric rhizome and the quality and resulting characteristics in powdered form

    Energy Technology Data Exchange (ETDEWEB)

    Peret-Almeida, Lucia [UNI-BH, Centro Universitario de Belo Horizonte, MG (Brazil); Junqueira, Roberto Goncalves; Gloria, Maria Beatriz A. [Universidade Federal de Minas Gerais (FAFAR/UFMG), Belo Horizonte, MG (Brazil). Fac. de Farmacia

    2008-07-01

    Rhizomes were submitted to doses of 0.00, 0.05, 0.10 and 0.15 kGy and stored at 26 {+-} 1 deg C and 85% relative humidity for 135 days. In 45 day intervals samples were collected for analysis of the rhizomes and processed into ground turmeric. The higher the dose the longer the time required for sprouting. At 0.15 kGy there was no sprouting up to 135 days of storage, however callus started to appear. The levels of curcuminoid pigments in ground turmeric were not affected by irradiation dose; however they varied with storage time. The CIE L{sup *}a{sup *}b{sup *} color characteristics of ground turmeric were not affected by radiation dose, but changed with storage time, except for 0.15 kGy. (author)

  20. Effects of gamma radiation on sprouting turmeric rhizome and the quality and resulting characteristics in powdered form

    International Nuclear Information System (INIS)

    Peret-Almeida, Lucia; Junqueira, Roberto Goncalves; Gloria, Maria Beatriz A.

    2008-01-01

    Rhizomes were submitted to doses of 0.00, 0.05, 0.10 and 0.15 kGy and stored at 26 ± 1 deg C and 85% relative humidity for 135 days. In 45 day intervals samples were collected for analysis of the rhizomes and processed into ground turmeric. The higher the dose the longer the time required for sprouting. At 0.15 kGy there was no sprouting up to 135 days of storage, however callus started to appear. The levels of curcuminoid pigments in ground turmeric were not affected by irradiation dose; however they varied with storage time. The CIE L * a * b * color characteristics of ground turmeric were not affected by radiation dose, but changed with storage time, except for 0.15 kGy. (author)