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Sample records for radiation cmbr spectrum

  1. Kalb–Ramond fields and the CMBR

    physics pp. 335–341. Kalb–Ramond fields and the CMBR. PARTHASARATHI MAJUMDAR. Department of Physics, Ramakrishna Mission Vivekananda University, Belur ... important signatures of 'physics beyond the Standard Model'. ... similar in some sense to Faraday rotation, but differing from it in one crucial aspect – the.

  2. The cosmic microwave background radiation and the dog in the night

    Partridge, R. B.

    The spectrum and angular distribution of the cosmic microwave background radiation (CMBR) are characterized, summarizing the results of recent observations. The emphasis is on null experiments which have established upper limits on anisotropies and spectral distortion. The benefits and pitfalls of null experiments are recalled; the generally observed isotropy of the CMBR and the possible ways anisotropy could be introduced are discussed; and data from searches for anisotropy on arcmin, degree, and arcsec scales are presented in tables and graphs and analyzed in detail. The observed CMBR spectrum is shown to be generally consistent with a black body at temperature 2.75 + or - 0.04 K at wavelengths from 0.1 to 12 cm, although some recent data (Kogut et al., 1988) seem to confirm the presence of distortion due to the Suniaev-Zel'dovich effect at wavelength 3.0 cm.

  3. Constraints on pre-big-bang parameter space from CMBR anisotropies

    Bozza, V.; Gasperini, M.; Giovannini, M.; Veneziano, G.

    2003-01-01

    The so-called curvaton mechanism--a way to convert isocurvature perturbations into adiabatic ones--is investigated both analytically and numerically in a pre-big-bang scenario where the role of the curvaton is played by a sufficiently massive Kalb-Ramond axion of superstring theory. When combined with observations of CMBR anisotropies at large and moderate angular scales, the present analysis allows us to constrain quite considerably the parameter space of the model: in particular, the initial displacement of the axion from the minimum of its potential and the rate of evolution of the compactification volume during pre-big-bang inflation. The combination of theoretical and experimental constraints favors a slightly blue spectrum of scalar perturbations, and/or a value of the string scale in the vicinity of the SUSY GUT scale

  4. Constraints on pre-big bang parameter space from CMBR anisotropies

    Bozza, Valerio; Giovannini, Massimo; Veneziano, Gabriele

    2003-01-01

    The so-called curvaton mechanism --a way to convert isocurvature perturbations into adiabatic ones-- is investigated both analytically and numerically in a pre-big bang scenario where the role of the curvaton is played by a sufficiently massive Kalb--Ramond axion of superstring theory. When combined with observations of CMBR anisotropies at large and moderate angular scales, the present analysis allows us to constrain quite considerably the parameter space of the model: in particular, the initial displacement of the axion from the minimum of its potential and the rate of evolution of the compactification volume during pre-big bang inflation. The combination of theoretical and experimental constraints favours a slightly blue spectrum of scalar perturbations, and/or a value of the string scale in the vicinity of the SUSY-GUT scale.

  5. Concise expression of a classical radiation spectrum

    Wang, C.

    1993-01-01

    In this paper we present a concise expression of the classical electromagnetic radiation spectrum of a moving charge. It is shown to be equivalent to the often used and much more complicated form derived from the Lienard-Wiechert potentials when the observation distance R satisfies the condition R much-gt γλ. The expression reveals a relationship between the radiation spectrum and the motion of the radiation source. It also forms the basis of an efficient computing approach, which is of practical value in numerical calculations of the spectral output of accelerated charges. The advantages of this approach for analytical and numerical applications are discussed and the bending-magnet synchrotron radiation spectrum is calculated according to the approach

  6. Measurement of the cosmic microwave background spectrum by the COBE FIRAS instrument

    Mather, J. C.; Cheng, E. S.; Cottingham, D. A.; Eplee, R. E., Jr.; Fixsen, D. J.; Hewagama, T.; Isaacman, R. B.; Jensen, K. A.; Meyer, S. S.; Noerdlinger, P. D.

    1994-01-01

    The cosmic microwave background radiation (CMBR) has a blackbody spectrum within 3.4 x 10(exp -8) ergs/sq cm/s/sr cm over the frequency range from 2 to 20/cm (5-0.5 mm). These measurements, derived from the Far-Infrared Absolute Spectrophotomer (FIRAS) instrument on the Cosmic Background Explorer (COBE) satellite, imply stringent limits on energy release in the early universe after t approximately 1 year and redshift z approximately 3 x 10(exp 6). The deviations are less than 0.30% of the peak brightness, with an rms value of 0.01%, and the dimensionless cosmological distortion parameters are limited to the absolute value of y is less than 2.5 x 10(exp -5) and the absolute value of mu is less than 3.3 x 10(exp -4) (95% confidence level). The temperature of the CMBR is 2.726 +/- 0.010 K (95% confidence level systematic).

  7. Effective spectrum width of the synchrotron radiation

    Bagrov, V. G., E-mail: bagrov@phys.tsu.ru [Department of Physics, Tomsk State University, Tomsk (Russian Federation); Institute of High Current Electronics, SB RAS, Tomsk (Russian Federation); Gitman, D. M., E-mail: gitman@if.usp.br [Department of Physics, Tomsk State University, Tomsk (Russian Federation); Institute of Physics, University of São Paulo, São Paulo (Brazil); P.N.Lebedev Physical Institute, Moscow (Russian Federation); Levin, A. D., E-mail: alevin@if.usp.br [Institute of Physics, University of São Paulo, São Paulo (Brazil); Loginov, A. S.; Saprykin, A. D. [Department of Physics, Tomsk State University, Tomsk (Russian Federation)

    2015-11-25

    For an exact quantitative description of spectral properties of synchrotron radiation (SR), the concept of effective width of the spectrum is introduced. In the most interesting case, which corresponds to the ultrarelativistic limit of SR, the effective width of the spectrum is calculated for the polarization components, and new physically important quantitative information on the structure of spectral distributions is obtained. For the first time, the spectral distribution for the circular polarization component of the SR for the upper half-space is obtained within classical theory.

  8. Effective spectrum width of the synchrotron radiation

    Bagrov, V. G.; Gitman, D. M.; Levin, A. D.; Loginov, A. S.; Saprykin, A. D.

    2015-01-01

    For an exact quantitative description of spectral properties of synchrotron radiation (SR), the concept of effective width of the spectrum is introduced. In the most interesting case, which corresponds to the ultrarelativistic limit of SR, the effective width of the spectrum is calculated for the polarization components, and new physically important quantitative information on the structure of spectral distributions is obtained. For the first time, the spectral distribution for the circular polarization component of the SR for the upper half-space is obtained within classical theory

  9. Effective spectrum width of the synchrotron radiation

    Bagrov, V.G. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); SB RAS, Institute of High Current Electronics, Tomsk (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); P.N. Lebedev Physical Institute, Moscow (Russian Federation); Levin, A.D. [University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); Loginov, A.S.; Saprykin, A.D. [Tomsk State University, Department of Physics, Tomsk (Russian Federation)

    2015-11-15

    For an exact quantitative description of spectral properties of synchrotron radiation (SR), the concept of effective width of the spectrum is introduced. In the most interesting case, which corresponds to the ultrarelativistic limit of SR, the effective width of the spectrum is calculated for the polarization components, and new physically important quantitative information on the structure of spectral distributions is obtained. For the first time, the spectral distribution for the circular polarization component of the SR for the upper half-space is obtained within classical theory. (orig.)

  10. Cysteine-mediated gene expression and characterization of the CmbR regulon in Streptococcus pneumoniae

    Muhammad Afzal

    2016-12-01

    Full Text Available In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to cysteine. Transcriptome comparison of the D39 wild-type strain grown at a restricted concentration of cysteine (0.03 mM to one grown at a high concentration of cysteine (50 mM in chemically-define medium (CDM revealed elevated expression of various genes/operons, i.e. spd-0150, metQ, spd-0431, metEF, gshT, spd-0618, fhs, tcyB, metB-csd, metA, spd-1898, yvdE, and cysK, likely to be involved in the transport and utilization of cysteine and/or methionine. Microarray-based data were further confirmed by quantitative RT-PCR. Promoter lacZ-fusion studies and quantitative RT-PCR data showed that the transcriptional regulator CmbR acts as a transcriptional repressor of spd-0150, metEF, gshT, spd-0618, tcyB, metA, and yvdE, putatively involved in cysteine uptake and utilization. The operator site of CmbR in the promoter regions of CmbR-regulated genes is predicted and confirmed by mutating or deleting CmbR operator sites from the promoter regions of these genes.

  11. Ralph A. Alpher, Robert C. Herman, and the Cosmic Microwave Background Radiation

    Alpher, Victor S.

    2012-09-01

    Much of the literature on the history of the prediction and discovery of the Cosmic Microwave Background Radiation (CMBR) is incorrect in some respects. I focus on the early history of the CMBR, from its prediction in 1948 to its measurement in 1964, basing my discussion on the published literature, the private papers of Ralph A. Alpher, and interviews with several of the major figures involved in the prediction and measurement of the CMBR. I show that the early prediction of the CMBR continues to be widely misunderstood.

  12. SLC energy spectrum monitor using synchrotron radiation

    Seeman, J.; Brunk, W.; Early, R.; Ross, M.; Tillmann, E.; Walz, D.

    1986-01-01

    The SLAC linac is being upgraded for the use in the SLAC Linear Collider (SLC). The improved linac must accelerate electron and positron bunches from 1.2 GeV to 50 GeV while producing output energy spectra of about 0.2%. The energy spectra must be maintained during operation to provide for good beam transmission and to minimize chromatic effects in the SLC ARCs and Final Focus. The energy spectra of these beams are determined by the bunch length and intensity, the RF phase and waveform and the intra-bunch longitudinal wakefields. A non-destructive energy spectrum monitor has been designed using a vertical wiggler magnet located downstream of the horizontal beam splitter at the end of the SLC linac. It produces synchrotron radiation which is viewed in an off-axis x-ray position sensitive detector. The expected resolution is 0.08 %. The design considerations of this monitor are presented. A pair of these monitors is under construction with an installation data set for late summer 1986

  13. SLC energy spectrum monitor using synchrotron radiation

    Seeman, J.; Brunk, W.; Early, R.; Ross, M.; Tillmann, E.; Walz, D.

    1986-04-01

    The SLAC Linac is being upgraded for the use in the SLAC Linear Collider (SLC). The improved Linac must accelerate electron and positron bunches from 1.2 GeV to 50 GeV while producing output energy spectra of about 0.2%. The energy spectra must be maintained during operation to provide for good beam transmission and to minimize chromatic effects in the SLC ARCs and Final Focus. the energy spectra of these beams are determined by the bunch length and intensity, the RF phase and waveform and the intra-bunch longitudinal wakefields. A non-destructive energy spectrum monitor has been designed using a vertical wiggler magnet located downstream of the horizontal beam splitter at the end of the SLC Linac. It produces synchrotron radiation which is viewed in an off-axis x-ray position sensitive detector. The expected resolution is 0.08%. The design considerations of this monitor are presented in this paper. A pair of these monitors is under construction with an installation date set for late summer 1986. 5 refs., 6 figs

  14. Existence of dark matter with observed properties of cosmic microwave background radiation substantiates three conservation laws of classical physics and all principles of quantum mechanics as creates the value of Planck’s constant

    Boriev, I. A.

    2018-03-01

    Astronomical data indicate a presence of dark matter (DM) in the space, what is necessary for explanation of observed dynamics of the galaxies within Newtonian mechanics. DM, at its very low density (∼10-26kg/m3), constitutes main part of the matter in the Universe, 10 times the mass of all visible cosmic bodies. No doubt, namely properties of DM, which fills space, must determine its physical properties and fundamental physical laws. Taking into account observed properties of cosmic microwave background radiation (CMBR), whose energy is ∼90% of all cosmic radiation, and understanding that this radiation is produced by DM motion, conservation laws of classical physics and principles of quantum mechanics receive their materialistic substantiation. Thus, CMBR high homogeneity and isotropy (∼10-4), and hence the same properties of DM (and space) justify momentum and angular momentum conservation laws, respectively, according to E. Noether's theorems. CMBR has black body spectrum at ∼2.7K with maximum wavelength ∼1.9·10-3m, what allows calculate the value of mechanical action produced by DM thermal motion (∼7·10-34 J·s). This value corresponds well to the Planck’s constant, which is the mechanical action too, what gives materialistic basis for all principles of quantum mechanics. Obtained results directly confirm the reality of DM existence, and show that CMBR is an observed display of DM thermal motion. Understanding that namely from DM occur known creation of electron-positron pairs as contrarily rotating material vortexes (according to their spins) let substantiate positron nature of ball lightning what first explains all its observed specific properties.

  15. On the omnipresent background gamma radiation of the continuous spectrum

    Banjanac, R.; Maletić, D.; Joković, D., E-mail: yokovic@ipb.ac.rs; Veselinović, N.; Dragić, A.; Udovičić, V.; Aničin, I.

    2014-05-01

    The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere, is studied by means of absorption measurements, both in a ground level and in an underground laboratory. The low-energy continuous portion of this background spectrum that peaks at around 100 keV, which is its most intense component, is found to be of very similar shape at the two locations. It is established that it is mostly due to the radiations of the real continuous spectrum, which is quite similar to the instrumental one. The intensity of this radiation is in our cases estimated to about 8000 photons/(m{sup 2}s·2π·srad) in the ground level laboratory, and to about 5000 photons/(m{sup 2}s·2π·srad) in the underground laboratory, at the depth of 25 m.w.e. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is predominantly of terrestrial origin, due to environmental gamma radiations scattered off the materials that surround the detector (the “skyshine radiation”), and to a far less extent to cosmic rays of degraded energy. - Highlights: • We studied the low-energy part of continuous background spectra of germanium detectors. • The study was performed at the ground level and at the shallow underground sites. • The instrumental spectrum is due to radiations of the similar continuous spectrum. • The low-energy radiation is of both terrestrial and cosmic-ray origin. • In our study, we find that this radiation is of predominantly terrestrial origin.

  16. The spectrum of radiation enteritis: surgical considerations

    Haddad, G.K.; Grodsinsky, C.; Allen, H.

    1983-01-01

    Radiation therapy, often used to treat gynecologic and urologic pelvic malignancies, has varying, adverse effects on the bowel. Radiation enteritis may occur from one month to 20 years after irradiation, and disabling symptoms may require surgery in 10 to 20 per cent of patients. From our experience with 20 patients who required surgery for radiation enteritis and who were followed for up to 20 years, we were able to identify three clinical groups. Patients in the first group need only medical treatment for their symptoms, and observation, whereas patients in the second group may present with acute, debilitating, life-threatening symptoms that may require emergency surgery. Patients in the third group have a long-standing history of intermittent bowel obstruction and/or enteric fistulas that are best treated with adequate nutritional support followed by timely surgical intervention

  17. Application of real time spectrum measurement to radiation monitors

    Matsuno, K.; Watanabe, M.; Sakamaki, T.

    1996-01-01

    A multichannel analyzer (MCA) and two realtime spectrum monitoring methods have been developed for use in radiation monitors. The new MCA was designed to be installed at a local site as a component of a radiation monitor. The MCA repeats spectrum measurement at short intervals (Δt) and, after each measurement, transmits a spectrum datum to the operation console. The authors applied two methods to process Δt spectrum counts for each channel for longer time interval. One method of processing counts is the 'running average (RA) method'. The other method is the 'exponential smoothing (ES) method', which simulates RC rate meters by subtracting a fraction corresponding to the accumulated counts. Relative standard deviations for each channel can be made the same by selecting an appropriate value. The response with the 'ES' method is initially faster than that with the 'RA' method, but the 'RA' method allows a full response to be reached at a predictable time. (author)

  18. Concept of quasi-periodic undulator - control of radiation spectrum

    Sasaki, Shigemi [Japan Atomic Energy Research Institute, Ibaraki (Japan)

    1995-02-01

    A new type of undulator, the quasi-periodic undulator (QPU) is considered which generates the irrational harmonics in the radiation spectrum. This undulator consists of the arrays of magnet blocks aligned in a quasi-periodic order, and consequentially lead to a quasi-periodic motion of electron. A combination of the QPU and a conventional crystal/grating monochromator provides pure monochromatic photon beam for synchrotron radiation users because the irrational harmonics do not be diffracted in the same direction by a monochromator. The radiation power and width of each radiation peak emitted from this undulator are expected to be comparable with those of the conventional periodic undulator.

  19. Spectrum and isotropy of the submillimeter background radiation

    Muehlner, D.

    1977-01-01

    Two great astronomical discoveries have most shaped our present concept of the Big Bang universe. Like the Hubble recession of the galaxies, the discovery of the 3 0 K background radiation by Penzias and Wilson in 1965 has given rise to a line of research which is still very active today. Penzias and Wilson's universal microwave background at 7 cm was immediately interpreted by R.H. Dicke's group at Princeton as coming from the primordial fireball of incandescent plasma which filled the universe for the million years or so after its explosive birth. This interpretation gives rise to two crucial predictions as to the nature of the background radiation. Its spectrum should be thermal even after having been red shifted by a factor of approximately 1000 by the expansion of the universe, and the radiation should be isotropic - assuming that the universe itself is isotropic. If the background radiation is indeed from the primordial fireball it affords us the only direct view at the very young universe. This paper deals with the spectrum and then the isotropy of the background radiation, with emphasis on high frequency or submillimeter measurements. Prospects for the future are discussed briefly. (Auth.)

  20. Cosmic microwave background dipole spectrum measured by the COBE FIRAS instrument

    Fixsen, D. J.; Cheng, E. S.; Cottingham, D. A.; Eplee, R. E., Jr.; Isaacman, R. B.; Mather, J. C.; Meyer, S. S.; Noerdlinger, P. D.; Shafer, R. A.; Weiss, R.

    1994-01-01

    The Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on the Cosmic Background Explorer (COBE) has determined the dipole spectrum of the cosmic microwave background radiation (CMBR) from 2 to 20/cm. For each frequency the signal is decomposed by fitting to a monopole, a dipole, and a Galactic template for approximately 60% of the sky. The overall dipole spectrum fits the derivative of a Planck function with an amplitude of 3.343 +/- 0.016 mK (95% confidence level), a temperature of 2.714 +/- 0.022 K (95% confidence level), and an rms deviation of 6 x 10(exp -9) ergs/sq cm/s/sr cm limited by a detector and cosmic-ray noise. The monopole temperature is consistent with that determined by direct measurement in the accompanying article by Mather et al.

  1. Coherent radiation spectrum measurements at KEK LUCX facility

    Shevelev, M., E-mail: mishe@post.kek.jp [KEK: High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Aryshev, A., E-mail: alar@post.kek.jp [KEK: High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Araki, S.; Fukuda, M. [KEK: High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Karataev, P. [John Adams Institute at Royal Holloway, University of London, Egham, Surrey TW20 0EX (United Kingdom); Terunuma, N.; Urakawa, J. [KEK: High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2015-01-21

    This paper demonstrates the detailed design concept, alignment, and initial testing of a Michelson interferometer for the THz spectral range. We present the first results on the measurement of a coherent transition radiation spectrum and describe the performance of a pair of ultra-fast broadband room temperature Schottky barrier diode detectors. We discuss the main criteria of interferometer beam splitter optimization, the alignment technique, the high-precision calibration and linearity check of the motion system.

  2. Comparison between a conventional membrane bioreactor (C-MBR and a biofilm membrane bioreactor (BF-MBR for domestic wastewater treatment

    E. L. Subtil

    2014-09-01

    Full Text Available In this paper, the influence of biofilm carriers in a MBR on the performance of organic matter and nitrogen removal and the influence on membrane fouling were evaluated. The configurations studied included a Conventional Membrane Bioreactor (C-MBR and a Biofilm Membrane Bioreactor (BF-MBR operated in parallel, both fed with domestic wastewater. Regarding organic matter removal, no statistically significant differences were observed between C-MBR and BF-MBR, producing an effluent with a Soluble COD concentration of 27 ± 9.0 mgO2/L and 26 ±1.0 mgO2/L and BOD concentration of 6.0 ± 2.5 mgO2/L and 6.2 ± 2.1 mgO2/L, respectively. On the other hand, the BF-MBR produced a permeate with lower ammonia and total nitrogen concentrations, which resulted in a removal efficiency of 98% and 73%, respectively. It was also observed that the fouling rate was about 35% higher in the C-MBR than that for the BF-MBR, which also presented a reduction of total membrane resistance, about 29%, and increased operational cycle length around 7 days, compared to C-MBR.

  3. An Analysis of Recent Measurements of the Temperature of the Cosmic Microwave Background Radiation

    Smoot, G.; Levin, S. M.; Witebsky, C.; De Amici, G.; Rephaeli, Y.

    1987-07-01

    This paper presents an analysis of the results of recent temperature measurements of the cosmic microwave background radiation (CMBR). The observations for wavelengths longer than 0.1 cum are well fit by a blackbody spectrum at 2.74{+ or -}0.0w K; however, including the new data of Matsumoto et al. (1987) the result is no longer consistent with a Planckian spectrum. The data are described by a Thomson-distortion parameter u=0.021{+ or -}0.002 and temperature 2.823{+ or -}0.010 K at the 68% confidence level. Fitting the low-frequency data to a Bose-Einstein spectral distortion yields a 95% confidence level upper limit of 1.4 x 10{sup -2} on the chemical potential mu{sub 0}. These limits on spectral distortions place restrictions on a number of potentially interesting sources of energy release to the CMBR, including the hot intergalactic medium proposed as the source of the X-ray background.

  4. Derivation of the blackbody radiation spectrum from the equivalence principle in classical physics with classical electromagnetic zero-point radiation

    Boyer, T.H.

    1984-01-01

    A derivation of Planck's spectrum including zero-point radiation is given within classical physics from recent results involving the thermal effects of acceleration through classical electromagnetic zero-point radiation. A harmonic electric-dipole oscillator undergoing a uniform acceleration a through classical electromagnetic zero-point radiation responds as would the same oscillator in an inertial frame when not in zero-point radiation but in a different spectrum of random classical radiation. Since the equivalence principle tells us that the oscillator supported in a gravitational field g = -a will respond in the same way, we see that in a gravitational field we can construct a perpetual-motion machine based on this different spectrum unless the different spectrum corresponds to that of thermal equilibrium at a finite temperature. Therefore, assuming the absence of perpetual-motion machines of the first kind in a gravitational field, we conclude that the response of an oscillator accelerating through classical zero-point radiation must be that of a thermal system. This then determines the blackbody radiation spectrum in an inertial frame which turns out to be exactly Planck's spectrum including zero-point radiation

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

    De Zotti, G.

    1982-01-01

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

  6. INCA project for investigation of primary cosmic radiation spectrum

    Aleksandrov, K.V.; Erlykin, A.D.; Zhdanov, G.B.

    2002-01-01

    The scientific purposes of the INCA project and application of the ionization-neutron calorimeter for direct measurements of the cosmic rays spectrum and composition in the knee area and the primary electrons spectrum by 10 14 - 10 13 eV are discussed. The new effective method for the primary electrons and protons separation with the complex rejection coefficient of 10 -5 - 10 -6 is proposed for studying the primary electrons spectrum by E e > 1 TeV. The experimental and calculation data are in good agreement [ru

  7. Dynamics of globular molecules: moisture effect on the Rayleigh scattering spectrum of the Moessbauer radiation

    Chesskaya, T.Yu.

    1998-01-01

    The Rayleigh scattering spectrum of the Moessbauer radiation is plotted on the model simulating globular macromolecules. The modeling results are compared with experimental data on the spectra of the Rayleigh scattering of the Moessbauer radiation for various moisture content and hydratation dependence of the elastic scattering portion

  8. Influence of filling pattern structure on synchrotron radiation and beam spectrum at ANKA

    Steinmann, Johannes; Brosi, Miriam; Bruendermann, Erik; Caselle, Michele; Blomley, Edmund; Hiller, Nicole; Kehrer, Benjamin; Mueller, Anke-Susanne; Schoenfeldt, Patrik; Schuh, Marcel; Schwarz, Markus; Siegel, Michael [Karlsruher Institut fuer Technologie, Karlsruhe (Germany)

    2016-07-01

    We present the effects of the filling pattern structure in multi-bunch mode on the beam spectrum. This effects can be seen by all detectors whose resolution is better than the RF frequency, ranging from stripline and Schottky measurements to high resolution synchrotron radiation measurements. Our heterodyne measurements of the emitted coherent synchrotron radiation at 270 GHz reveal the discrete frequency harmonics around the 100'000 revolution harmonic of ANKA, the synchrotron radiation facility in Karlsruhe, Germany. Significant effects of bunch spacing, gaps between bunch trains and variations in individual bunch currents on the emitted CSR spectrum are described by theory and supported by observations.

  9. Oscillations in the spectrum of nonlinear Thomson-backscattered radiation

    C. A. Brau

    2004-02-01

    Full Text Available When an electron beam collides with a high-intensity laser beam, the spectrum of the nonlinear Thomson scattering in the backward direction shows strong oscillations like those in the spectrum of an optical klystron. Laser gain on the backward Thomson scattering is estimated using the Madey theorem, and the results suggest that Thomson-backscatter free-electron lasers are possible at wavelengths extending to the far uv using a terawatt laser beam from a chirped-pulse amplifier and a high-brightness electron beam from a needle cathode.

  10. On the continuous spectrum electromagnetic radiation in electron-fullerene collision

    Amusia, M.Y.

    1995-01-01

    It is demonstrated that the electromagnetic radiation spectrum in electron-fullerene collisions is dominated by a huge maximum of multielectron nature, similar to that already predicted and observed in photoabsorption. Due to coherence, the intensity of this radiation is much stronger than the sum of the intensities of isolated atoms. Experimental detection of such radiation would be of great importance for understanding the mechanism of its formation and for investigating fullerene structures. A paper describing these results was published

  11. Interstellar cyanogen and the temperature of the cosmic microwave background radiation

    Roth, Katherine C.; Meyer, David M.; Hawkins, Isabel

    1993-01-01

    We present the results of a recently completed effort to determine the amount of CN rotational excitation in five diffuse interstellar clouds for the purpose of accurately measuring the temperature of the cosmic microwave background radiation (CMBR). In addition, we report a new detection of emission from the strongest hyperfine component of the 2.64 mm CN rotational transition (N = 1-0) in the direction toward HD 21483. We have used this result in combination with existing emission measurements toward our other stars to correct for local excitation effects within diffuse clouds which raise the measured CN rotational temperature above that of the CMBR. After making this correction, we find a weighted mean value of T(CMBR) = 2.729 (+0.023, -0.031) K. This temperature is in excellent agreement with the new COBE measurement of 2.726 +/- 0.010 K (Mather et al., 1993). Our result, which samples the CMBR far from the near-Earth environment, attests to the accuracy of the COBE measurement and reaffirms the cosmic nature of this background radiation. From the observed agreement between our CMBR temperature and the COBE result, we conclude that corrections for local CN excitation based on millimeter emission measurements provide an accurate adjustment to the measured rotational excitation.

  12. Spectrum

    Høgfeldt Hansen, Leif

    2016-01-01

    The publication functions as a proces description of the development and construction of an urban furniture SPECTRUM in the city of Gwangju, Republic of Korea. It is used as the cataloque for the exhibition of Spectrum.......The publication functions as a proces description of the development and construction of an urban furniture SPECTRUM in the city of Gwangju, Republic of Korea. It is used as the cataloque for the exhibition of Spectrum....

  13. The spectrum of mutation produced by low dose radiation

    Morley, Alexander A.; Turner, David R.

    2004-01-01

    Inherited mutations are the basis of evolution and acquired mutations in humans are important in ageing, cancer and possibly various forms of tissue degeneration. Mutations are responsible for many of the long-term effects of radiation. However, sensitive direct detection of mutations in humans has been difficult. The aims of the project were to develop methods for the sensitive enumeration of mutations in DNA, to measure mutation frequencies in a wide variety of tissue types and to quantify the mutational effect of direct oxidative damage produced by radiation, at both high and low doses. The project was successful in developing a sensitive method which could detect mutations directly in the genetic material, DNA at a sensitivity of 1 mutated molecule in 1000000000 unmutated molecules. However a number of methodological problems had to be overcome and lack of ongoing funding made it impossible to fulfill all of the aims of the project

  14. Spectrum of rectal radiation lesions in cases of cancer cervix

    Srivastava, V.K.; Rohatgi, V.K.; Gupta, J.C.

    1978-01-01

    The study was carried out in 70 cases of carcinoma cervix uteri, showing varying degree of proctitis following radiotherapy treatment for cervical cancer. Grossly, the rectal mucosa showed oedema, congestion, granular proctitis, ulceration, and microscopically stromal connective tissue as well as epithelial changes. The stromal changes have been emphasised as useful diagnostic criteria of radiation reaction. The familarity of these changes is considered necessary because it is imperative to know categorically that a given lesion is entirely or in part due to radiation or due to extension of adjacent tumour in the cervix. Further, this issue is very important in management of cases of cancer cervix. The criteria of distinguishing the lesions in the rectal tissue have been laid down. (auth.)

  15. Simulating of spectrum and polarization characteristics of ultrarelativistic - electron coherent radiation in a diamond crystal

    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

  16. Induction of DNA-protein crosslinks in human cells by ultraviolet and visible radiations: action spectrum

    Peak, J.G.; Peak, M.J.; Sikorski, R.S.; Jones, C.A.

    1985-01-01

    DNA-protein crosslinking was induced in cultured human P3 teratocarcinoma cells by irradiation with monochromatic radiation with wavelengths in the range 254-434 nm (far-UV, near-UV, and blue light). Wavelength 545 nm green light did not induce these crosslinks, using the method of alkaline elution of the DNA from membrane filters. The action spectrum for the formation of DNA-protein crosslinks revealed two maxima, one in the far-UV spectrum that closely coincided with the relative spectrum of DNA at 254 and 290 nm, and one in the visible light spectrum at 405 nm, which has no counterpart in the DNA spectrum. The primary events for the formation of DNA-protein crosslinks by such long-wavelength radiation probably involve photosensitizers. This dual mechanism for DNA-protein crosslink formation is in strong contrast to the single mechanism for pyrimidine dimer formation in DNA, which apparently has no component in the visible light spectrum

  17. Photocatalytic ROS production and phototoxicity of titanium dioxide nanoparticles is dependent on solar UV radiation spectrum

    Generation of reactive oxygen species (ROS) by titanium dioxide nanoparticles (nano-TiO2) and its consequent phototoxicity to Daphnia magna were measured under different solar UV radiation spectrum by applying a series of optical filters in a solar simulator. Removing UVB (280-32...

  18. Molecular spectrum of laterally coupled quantum rings under intense terahertz radiation.

    Baghramyan, Henrikh M; Barseghyan, Manuk G; Laroze, David

    2017-09-05

    We study the influence of intense THz laser radiation and electric field on molecular states of laterally coupled quantum rings. Laser radiation shows the capability to dissociate quantum ring molecule and add 2-fold degeneracy to the molecular states at the fixed value of the overlapping size between rings. It is shown that coupled to decoupled molecular states phase transition points form almost a straight line with a slope equal to two. In addition, the electric field direction dependent energy spectrum shows unexpected oscillations, demonstrating strong coupling between molecular states. Besides, intraband absorption is considered, showing both blue and redshifts in its spectrum. The obtained results can be useful for the controlling of degeneracy of the discrete energy spectrum of nanoscale structures and in the tunneling effects therein.

  19. Importance of the neutron spectrum for determination of radiation damage

    Hehn, G.; Stiller, P.; Mattes, M.

    1977-01-01

    Since the radiation effects of neutrons depend strongly on the neutron energy, the correlation between the induced damage and the fluence of the fast neutrons shows appreciable disadvantages. The measured values of changes in material properties resulted in large differences for the same fast neutron fluence, being partly due to different neutron spectra. The uncertainties in damage data led to strong overdesign of important structural components. Different neutron environment at surveillance sample position may give an underestimation of the embrittlement in the reactor pressure vessel, which has to be avoided. The application of damage functions combined with accurately calculated neutron spectra, promise to be a reasonable solution. The damage function has the advantage of a phenomenological quantity that all spectral effects are included. But the correlation quantity has to be determined of high experimental costs. Therefore approximations of its energy distributions are very important. For the keV energy region the kerma function is reasonably good. For the MeV energy region a higher effort is needed to calculate the displacement cross section. The same holds for the low energy part. In all three parts the formation of stable material property levels may vary, so that the final correlation can be determined only by measurements of material properties in different neutron spectra. In material samples the spectra distribution of the displacement production rate was determined at different local positions outside the reactor core of a PWR and a fast breeder showing the most important energy regions of both reactors. (orig.) [de

  20. Quantum Corrected Non-Thermal Radiation Spectrum from the Tunnelling Mechanism

    Subenoy Chakraborty

    2015-06-01

    Full Text Available The tunnelling mechanism is today considered a popular and widely used method in describing Hawking radiation. However, in relation to black hole (BH emission, this mechanism is mostly used to obtain the Hawking temperature by comparing the probability of emission of an outgoing particle with the Boltzmann factor. On the other hand, Banerjee and Majhi reformulated the tunnelling framework deriving a black body spectrum through the density matrix for the outgoing modes for both the Bose-Einstein distribution and the Fermi-Dirac distribution. In contrast, Parikh and Wilczek introduced a correction term performing an exact calculation of the action for a tunnelling spherically symmetric particle and, as a result, the probability of emission of an outgoing particle corresponds to a non-strictly thermal radiation spectrum. Recently, one of us (C. Corda introduced a BH effective state and was able to obtain a non-strictly black body spectrum from the tunnelling mechanism corresponding to the probability of emission of an outgoing particle found by Parikh and Wilczek. The present work introduces the quantum corrected effective temperature and the corresponding quantum corrected effective metric is written using Hawking’s periodicity arguments. Thus, we obtain further corrections to the non-strictly thermal BH radiation spectrum as the final distributions take into account both the BH dynamical geometry during the emission of the particle and the quantum corrections to the semiclassical Hawking temperature.

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

    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

  2. The infrared radiation spectrum of acupoint taiyuan (LU 9) in asthma patients.

    Zhou, Yu; Shen, Xue-yong; Wang, Li-zhen; Wei, Jian-zi; Cheng, Ke

    2012-06-01

    To analyze the distinctive pathological characteristics in the spectrums of spontaneous infrared radiation at the Taiyuan (LU 9) acupoint in patients with asthma. A highly sensitive infrared spectrum detecting device was used to detect the spectrums of spontaneous infrared radiation at Taiyuan (LU 9) in 37 asthma patients and 34 healthy volunteers. Asthma patients had significantly lower infrared intensity than that of the healthy volunteers (P>0.01). Asthma patients had significantly lower overall infrared radiation intensity at the left Taiyuan (LU 9) than that of healthy volunteers (P > 0.05), but there was no significant difference between healthy volunteers and asthma patients at the right Taiyuan (LU 9) (P > 0.05). The infrared radiation intensity of 17 wavelength spots at the left Taiyuan (LU 9) and 4 wavelength spots at the right Taiyuan (LU 9) in asthma patients were significantly lower than those of healthy volunteers (P > 0.05). At 2 microm, the infrared radiation intensity of asthma patients was significantly stronger than that of healthy volunteers (P > 0.05). At 19 wavelength spots in the healthy volunteers and at 4 wave-length spots in the asthma patients, the left Taiyuan (LU 9) showed a significantly stronger intensity than that of the right Taiyuan (LU 9) (P > 0.05S). By Pearson's chi2 test, healthy volunteers had more wavelength spots that were significantly different between the left and right Taiyuan (LU 9) than the asthma patients (P > 0.01). Changes in the infrared spectrum at the Taiyuan (LU 9) acupoint in asthma patients may reflect distinct pathological changes. Certain acupuncture points may be related to specific organs.

  3. Dependence of effective spectrum width of synchrotron radiation on particle energy

    Bagrov, V.G. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Institute of High Current Electronics, Tomsk (Russian Federation); University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); P.N. Lebedev Physical Institute, Moscow (Russian Federation); Levin, A.D. [University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); Loginov, A.S.; Saprykin, A.D. [Tomsk State University, Department of Physics, Tomsk (Russian Federation)

    2017-05-15

    In the classical theory of synchrotron radiation, for the exact quantitative characterization of spectral properties, the concept of effective spectral width is introduced. In the first part of our work, published in EJPC 75 (2015), the effective spectral width as a function of the energy E of the radiating particle was obtained only in the ultra-relativistic approximation. In this article, which can be considered as a natural continuation of this work, a complete investigation is presented of the dependence of the effective width of the synchrotron radiation spectrum on energy for any values of E and for all the polarization components of the radiation. Numerical calculations were carried out for an effective width not exceeding 100 harmonics. (orig.)

  4. Cerenkov light spectrum in an optical fiber exposed to a photon or electron radiation therapy beam

    Lambert, Jamil; Yin Yongbai; McKenzie, David R.; Law, Sue; Suchowerska, Natalka

    2009-01-01

    A Cerenkov signal is generated when energetic charged particles enter the core of an optical fiber. The Cerenkov intensity can be large enough to interfere with signals transmitted through the fiber. We determine the spectrum of the Cerenkov background signal generated in a poly(methyl methacrylate) optical fiber exposed to photon and electron therapeutic beams from a linear accelerator. This spectral measurement is relevant to discrimination of the signal from the background, as in scintillation dosimetry using optical fiber readouts. We find that the spectrum is approximated by the theoretical curve after correction for the wavelength dependent attenuation of the fiber. The spectrum does not depend significantly on the angle between the radiation beam and the axis of the fiber optic but is dependent on the depth in water at which the fiber is exposed to the beam.

  5. Collisional-radiative model for the visible spectrum of W{sup 26+} ions

    Ding, Xiaobin, E-mail: dingxb@nwnu.edu.cn [Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Liu, Jiaxin [Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Koike, Fumihiro [Department of Physics, Sophia University, Tokyo, 102-8554 (Japan); Murakami, Izumi; Kato, Daiji; Sakaue, Hiroyuki A. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Nakamura, Nobuyuki [Institute for Laser Science, The University of Electro-Communications, Chofu, Tokyo 182-8585 (Japan); Dong, Chenzhong [Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China)

    2016-02-22

    Plasma diagnostics in magnetic confinement fusion plasmas by using visible spectrum strongly depends on the knowledge of fundamental atomic properties. A detailed collisional-radiative model of W{sup 26+} ions has been constructed by considering radiative and electron excitation processes, in which the necessary atomic data had been calculated by relativistic configuration interaction method with the implementation of Flexible Atomic Code. The visible spectrum observed at an electron beam ion trap (EBIT) in Shanghai in the range of 332 nm to 392 nm was reproduced by present calculations. Some transition pairs of which the intensity ratio is sensitive to the electron density were selected as potential candidates of plasma diagnostics. Their electron density dependence is theoretically evaluated for the cases of EBIT plasmas and magnetic confinement fusion plasmas.

  6. Action spectrum for inhibition by ultraviolet radiation of photosystem 2 activity in spinach thylakoids

    Bornman, J.F.; Bjoern, L.O.; Aakerlund, H.-E.

    1984-01-01

    The effect of ultraviolet (UV) radiation (half-band width 10 nm) in the wavelength range 248-340 nm on chlorophyll fluorescence from a thin layer of spinach thylakoid suspension was investigated. It was found that the parameter most sensitive to UV radiation was the rise time of variable fluorescence. The increase in rise time was proportional to UV photon fluence and was used for the determination of an action spectrum. The action spectrum falls off from a maximum at ca. 275 nm towards longer wavelengths and rises from a minimum at 260 nm towards shorter wavelengths. The results also suggest that the UV inhibition is mainly on the PS 2 oxidizing side. Possibly damage is also inflicted to the PS 2 reaction center. (orig.)

  7. Concerning the electromagnetic radiation spectrum of a hot plasma with Langmuir turbulence in a magnetic field

    Tirsky, V.V.; Ledenev, V.G.; Tomozov, V.M.

    2001-01-01

    We consider the process of generation of electromagnetic waves as a consequence of the merging of two Langmuir plasmons. The case of a hot plasma in a magnetic field is investigated. It is shown that under such conditions the frequency of Langmuir plasmons can vary over the range from 0.8 to 1.1 of the Langmuir frequency of electrons. The spectrum and polarization of electromagnetic radiation are analyzed. It is shown that allowance for the thermal motion of plasma particles under the conditions involved permits electromagnetic waves in the range from 1.6 to 2.2 of the Langmuir frequency of electrons to be generated. The degree of circular polarization of the radiation can reach 50% even in the case of an isotropic spectrum of Langmuir turbulence. (orig.)

  8. A measurement of the low frequency spectrum of the cosmic microwave background radiation

    Levin, S.M.

    1987-04-01

    As part of a larger effort to measure the spectrum of the Cosmic Background Radiation (CBR) at low frequencies, the intensity of the CBR has been measured at a frequency of 1.410 GHz. The measurement was made by comparing the power received from the sky with the power received from a specially designed cooled calibration target with known properties. Sources of radiation other than the CBR were then identified and subtracted to calculate the antenna temperature of the CBR at 1.410 GHz. The instrument used to measure the CBR was a total-power microwave radiometer with a 25 MHz bandwidth centered at 1.410 GHz. The radiometer had a noise temperature of 80 K, and sufficient data were taken that radiometer noise did not contribute significantly to the total measurement error. The sources of error were predominantly systematic in nature, and the largest error was due to uncertainty in the reflection characteristics of the cold-load calibrator. Identification and subtraction of signals from the Galaxy (0.7 K) and the Earth's atmosphere (0.8 K) were also significant parts of the data reduction and error analysis. The brightness temperature of the Cosmic Background Radiation at 1.410 GHz is 222. +- 0.55 Kelvin. The spectrum of the CBR, as determined by this measurement and other published results, is consistent with a blackbody spectrum of temperature 2.741 +- 0.016. Constraints on the amount by which the CBR spectrum deviates from Planck spectrum are used to place limits on energy releases early in the history of the universe. 55 refs., 25 figs., 8 tabs

  9. THE NuSTAR X-RAY SPECTRUM OF HERCULES X-1: A RADIATION-DOMINATED RADIATIVE SHOCK

    Wolff, Michael T.; Wood, Kent S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Becker, Peter A. [Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030-4444 (United States); Gottlieb, Amy M.; Marcu-Cheatham, Diana M.; Pottschmidt, Katja [Department of Physics and Center for Space Science and Technology, University of Maryland Baltimore County, Baltimore, MD 21250 (United States); Fürst, Felix [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Hemphill, Paul B. [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0424 (United States); Schwarm, Fritz-Walter; Wilms, Jörn [Dr. Karl-Remeis-Sternwarte and ECAP, Sternwartstr, 7, D-96049 Bamberg (Germany)

    2016-11-10

    We report on new spectral modeling of the accreting X-ray pulsar Hercules X-1. Our radiation-dominated radiative shock model is an implementation of the analytic work of Becker and Wolff on Comptonized accretion flows onto magnetic neutron stars. We obtain a good fit to the spin-phase-averaged 4–78 keV X-ray spectrum observed by the Nuclear Spectroscopic Telescope Array during a main-on phase of the Her X-1 35 day accretion disk precession period. This model allows us to estimate the accretion rate, the Comptonizing temperature of the radiating plasma, the radius of the magnetic polar cap, and the average scattering opacity parameters in the accretion column. This is in contrast to previous phenomenological models that characterized the shape of the X-ray spectrum, but could not determine the physical parameters of the accretion flow. We describe the spectral fitting details and discuss the interpretation of the accretion flow physical parameters.

  10. A discrepancy observed in the dipole anisotropy in the radio sky at 1.4 GHz and that in the CMBR – A threat to the cosmological principle?

    Singal, Ashok K

    2014-01-01

    According to the cosmological principle, the sky brightness at any frequency should appear uniform in all directions to an observer considered to be fixed in the co-moving coordinate system of the expanding universe. However a peculiar motion of the observer introduces a dipole anisotropy in the observed sky brightness, which should be independent of the observing frequency. We have examined the angular distribution in the radio-sky brightness, i.e., an integrated emission from discrete sources per unit solid angle, from the NVSS sample containing 1.8 million discrete radio sources at 1.4 GHz. Our results give a dipole anisotropy which is in the same direction as that of the CMBR from the COBE or WMAP, but the magnitude we find is about 4 times larger at a statistically significant (about 3σ) level. A genuine difference between the two dipoles cannot arise from the observer's motion alone, and it would imply intrinsically anisotropic universe, with anisotropy changing with the epoch. This would violate the cosmological principle where isotropy of the universe is assumed for all epochs, and on which the whole modern cosmology is based upon

  11. Evolution of Xe spectrum and ion charge under sudden incoming radiation

    Klapisch, Marcel; Busquet, Michel

    2012-06-01

    Experiments [1] and simulations of Xe at high temperature were recently reported, due to the possible scaling of astrophysical radiative shocks [2]. We used the newest version of HULLAC [3] to compute energy levels, radiative and collisional transition rates and level populations in a Coronal Radiative Model for the ions Xe9+ to Xe44+ (36263 configurations), at electron temperature of 100 eV and electron density of 10^19 -- 10^21 e/cm^3, in the presence of an external Planckian radiation field. Static and time dependent influence of the radiation on ion charge and spectrum is described. We show an effect of shell structure on relaxation of ion charge when the radiation field is suddenly turn on.[4pt] [1] Busquet, M., Thais, F., Gonzalez, M., et al., J. App. Phys. 107, 083302 (2010).[0pt] [2] Ryutov, D., Drake, R. P., Kane, J., et al., Astrophys. J. 518, 821 (1999).[0pt] [3] Klapisch, M. and Busquet, M., High Ener. Dens. Phys. 7, 98 (2011).

  12. Effects of synchrotron radiation spectrum energy on polymethyl methacrylate photosensitivity to deep x-ray lithography

    Mekaru, Harutaka; Utsumi, Yuichi; Hattori, Tadashi

    2003-01-01

    Since X-ray lithography requires a high photon flux to achieve deep resist exposure, a synchrotron radiation beam, which is not monochromatized, is generally used as a light source. If the synchrotron radiation beam is monochromatized, photon flux will decrease rapidly. Because of this reason, the wavelength dependence of the resist sensitivity has not been investigated for deep X-ray lithography. Measuring the spectrum of a white beam with a Si solid-state detector (SSD) is difficult because a white beam has a high intensity and an SSD has a high sensitivity. We were able to measure the spectrum and the photocurrent of a white beam from a beam line used for deep X-ray lithography by keeping the ring current below 0.05 mA. We evaluated the characteristics of the output beam based on the measured spectrum and photocurrent, and used them to investigate the relationship between the total exposure energy and the dose-processing depth with polymethyl methacrylate (PMMA). We found that it is possible to guess the processing depth of PMMA from the total exposure energy in deep X-ray lithography. (author)

  13. [A Method to Reconstruct Surface Reflectance Spectrum from Multispectral Image Based on Canopy Radiation Transfer Model].

    Zhao, Yong-guang; Ma, Ling-ling; Li, Chuan-rong; Zhu, Xiao-hua; Tang, Ling-li

    2015-07-01

    Due to the lack of enough spectral bands for multi-spectral sensor, it is difficult to reconstruct surface retlectance spectrum from finite spectral information acquired by multi-spectral instrument. Here, taking into full account of the heterogeneity of pixel from remote sensing image, a method is proposed to simulate hyperspectral data from multispectral data based on canopy radiation transfer model. This method first assumes the mixed pixels contain two types of land cover, i.e., vegetation and soil. The sensitive parameters of Soil-Leaf-Canopy (SLC) model and a soil ratio factor were retrieved from multi-spectral data based on Look-Up Table (LUT) technology. Then, by combined with a soil ratio factor, all the parameters were input into the SLC model to simulate the surface reflectance spectrum from 400 to 2 400 nm. Taking Landsat Enhanced Thematic Mapper Plus (ETM+) image as reference image, the surface reflectance spectrum was simulated. The simulated reflectance spectrum revealed different feature information of different surface types. To test the performance of this method, the simulated reflectance spectrum was convolved with the Landsat ETM + spectral response curves and Moderate Resolution Imaging Spectrometer (MODIS) spectral response curves to obtain the simulated Landsat ETM+ and MODIS image. Finally, the simulated Landsat ETM+ and MODIS images were compared with the observed Landsat ETM+ and MODIS images. The results generally showed high correction coefficients (Landsat: 0.90-0.99, MODIS: 0.74-0.85) between most simulated bands and observed bands and indicated that the simulated reflectance spectrum was well simulated and reliable.

  14. Program controlled system for measuring and monitoring the electron coherent radiation spectrum of Yerevan synchrotron

    Adamyan, F.V.; Vartapetyan, G.A.; Galumyan, P.I.

    1980-01-01

    An automatic system for measurement, processing and control of energy spectrum of polarized photons realized at the Yerevan electron synchrotron is described. For measuring energy spectra of intensive high energy photon beams a pair spectrometer is used which comprises an aluminium target-converter, an analizing magnet and 2 telescopes of scintillation counters for electron-positron pairs registration. the procedure of spectra measurement by the pair spectrometer is reduced to determining the converted e + e - pairs yield at certain values of the H field intensity of the analizing magnet. An algorithm of the data express-processing for operative monitoring of peak energy stability of electron coherent radiation spectrum is given. The spectra measurement results obtained under real experimental conditions are presented

  15. INFLUENCE OF THE ORTHOGONALLY POLARIZED BACK REFLECTIONS ON THE POWER AND RADIATION SPECTRUM OF SUPERLUMINESCENT DIODES

    A. B. Mukhtubayev

    2015-01-01

    Full Text Available We have investigated the back reflections influence on the spectrum for optical radiation source of superluminescent diode type and have provided optimal operating conditions of the radiation source. The feature of the research method is the usage of a fiber polarization controller and an optical mirror coated on the end of an optical fiber. The studies were conducted with two sources of optical radiation: ThorLabs superluminescent diode series S5FC1005SXL and LED module ELED-1550-1-E-9-SM1-FA-CW. It was revealed that at the value of back reflections equal to -13 dB relative to the output power source, a negative impact on power and spectral characteristics of the source with an optical power of 2.3 µW is beginning to appear. It was also confirmed that at the increase of the radiation power by increasing the source pumping current, back reflection influence is exhibiting at a lower level of back reflections. The results obtained need to be considered when designing fiber optic sensors in order to eliminate the effect of back reflections on the sources of optical radiation having been studied in this paper.

  16. Amplification of electromagnetic radiation in the exciton region of the spectrum of a semiconductor

    Nerkararyan, Kh.V.

    1989-01-01

    The problem of amplification of electromagnetic radiation in the exciton region of the spectrum of a semiconductor was first discussed by Haken. The possibility of amplification of an electromagnetic wave under conditions of Bose condensation of biexcitons was considered in Ref. 2. However, the difficulties encountered in the creation of a Bose condensed state of biexcitons complicate greatly the performance of an experiment of this kind. The authors shall show that amplification is possible also in a gaseous mixture of excitons and biexcitons which is in thermal equilibrium and can be described by the Maxwellian distribution function of the velocities

  17. Radiative natural SUSY spectrum from deflected AMSB scenario with messenger-matter interactions

    Wang, Fei [School of Physics, Zhengzhou University,Zhengzhou 450000 (China); State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics, Chinese Academy of Sciences,Beijing 100080 (China); Yang, Jin Min [State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics, Chinese Academy of Sciences,Beijing 100080 (China); Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Zhang, Yang [State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics, Chinese Academy of Sciences,Beijing 100080 (China)

    2016-04-29

    A radiative natural SUSY spectrum are proposed in the deflected anomaly mediation scenario with general messenger-matter interactions. Due to the contributions from the new interactions, positive slepton masses as well as a large |A{sub t}| term can naturally be obtained with either sign of deflection parameter and few messenger species (thus avoid the possible Landau pole problem). In this scenario, in contrast to the ordinary (radiative) natural SUSY scenario with under-abundance of dark matter (DM), the DM can be the mixed bino-higgsino and have the right relic density. The 125 GeV Higgs mass can also be easily obtained in our scenario. The majority of low EW fine tuning points can be covered by the XENON-1T direct detection experiments.

  18. Changing of Bacteria Catalase Activity Under the Influence of Electro-Magnetic Radiation on a Frequency of Nitric Oxide Absorption and Radiation Molecular Spectrum

    G.M. Shub

    2009-09-01

    Full Text Available The dynamics of catalase activity degree changing in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is described under the influence of electro-magnetic radiation on a frequency of nitric oxide absorption and radiation molecular spectrum. The panoramic spectrometric measuring complex, developed in Central Scientific Research Institute of measuring equipment Public corporation, Saratov, was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the structure of nitric oxide absorption and radiation molecular spectrum. The growth of activity of the mentioned enzyme of the strains under research was detected. The most significant changes were observed under 60-minutes exposure.

  19. [Detection of endotoxins of Gram-negative bacteria on the basis of electromagnetic radiation frequency spectrum].

    Likhoded, V G; Kuleshova, N V; Sergieva, N V; Konev, Iu V; Trubnikova, I A; Sudzhian, E V

    2007-01-01

    Method of Gram-negative bacteria endotoxins detection on the basis of their own spectrum of electromagnetic radiation frequency was developed. Frequency spectrum typical for chemotype Re glycolipid, which is a part of lypopolysaccharides in the majority of Gram-negative bacteria, was used. Two devices--"Mini- Expert-DT" (manufactured by IMEDIS, Moscow) and "Bicom" (manufactured by Regumed, Germany)--were used as generators of electromagnetic radiation. Detection of endotoxin using these devices was performed by electropuncture vegetative resonance test. Immunoenzyme reaction with antibodies to chemotype Re glycolipid was used during analysis of preparations for assessment of resonance-frequency method specificity. The study showed that resonance-frequency method can detect lypopolysaccharides of different enterobacteria in quantities up to 0.1 pg as well as bacteria which contain lypopolysaccharides. At the same time, this method does not detect such bacteria as Staphylococcus aureus, Bifidobacterium spp., Lactobacillus spp., and Candida albicans. The method does not require preliminary processing of blood samples and can be used for diagnostics of endotoxinemia, and detection of endotoxins in blood samples or injection solutions.

  20. A measurement of the medium-scale anisotropy in the cosmic microwave background radiation

    Cheng, E. S.; Cottingham, D. A.; Fixsen, D. J.; Inman, C. A.; Kowitt, M. S.; Meyer, S. S.; Page, L. A.; Puchalla, J. L.; Silverberg, R. F.

    1994-01-01

    Observations from the first flight of the Medium Scale Anisotropy Measurement (MSAM) are analyzed to place limits on Gaussian fluctuations in the cosmic microwave background radiation (CMBR). This instrument chops a 30 min beam in a three-position pattern with a throw of +/- 40 min; the resulting data is analyzed in statistically independent single- and double-difference sets. We observe in four spectral channels at 5.6, 9.0, 16.5, and 22.5/cm, allowing the separation of interstellar dust emission from CMBR fluctuations. The dust component is correlated with the IRAS 100 micron map. The CMBR component has two regions where the signature of an unresolved source is seen. Rejecting these two source regions, we obtain a detection of fluctuations which match CMBR in our spectral bands of 0.6 x 10(exp -5) is less than Delta (T)/T is less than 2.2 x 10(exp -5) (90% CL interval) for total rms Gaussian fluctuations with correlation angle 0.5 deg, using the single-difference demodulation. Fore the double difference demodulation, the result is 1.1 x 10(exp -5) is less than Delta(T)/T is less than 3.1 x 10(exp -5) (90% CL interval) at a correlation angle of 0.3 deg.

  1. Chest CT using spectral filtration: radiation dose, image quality, and spectrum of clinical utility

    Braun, Franziska M.; Johnson, Thorsten R.C.; Sommer, Wieland H.; Thierfelder, Kolja M.; Meinel, Felix G. [University Hospital Munich, Institute for Clinical Radiology, Munich (Germany)

    2015-06-01

    To determine the radiation dose, image quality, and clinical utility of non-enhanced chest CT with spectral filtration. We retrospectively analysed 25 non-contrast chest CT examinations acquired with spectral filtration (tin-filtered Sn100 kVp spectrum) compared to 25 examinations acquired without spectral filtration (120 kV). Radiation metrics were compared. Image noise was measured. Contrast-to-noise-ratio (CNR) and figure-of-merit (FOM) were calculated. Diagnostic confidence for the assessment of various thoracic pathologies was rated by two independent readers. Effective chest diameters were comparable between groups (P = 0.613). In spectral filtration CT, median CTDI{sub vol}, DLP, and size-specific dose estimate (SSDE) were reduced (0.46 vs. 4.3 mGy, 16 vs. 141 mGy*cm, and 0.65 vs. 5.9 mGy, all P < 0.001). Spectral filtration CT had higher image noise (21.3 vs. 13.2 HU, P < 0.001) and lower CNR (47.2 vs. 75.3, P < 0.001), but was more dose-efficient (FOM 10,659 vs. 2,231/mSv, P < 0.001). Diagnostic confidence for parenchymal lung disease and osseous pathologies was lower with spectral filtration CT, but no significant difference was found for pleural pathologies, pulmonary nodules, or pneumonia. Non-contrast chest CT using spectral filtration appears to be sufficient for the assessment of a considerable spectrum of thoracic pathologies, while providing superior dose efficiency, allowing for substantial radiation dose reduction. (orig.)

  2. An action spectrum for UV-B radiation and the rat lens.

    Merriam, J C; Löfgren, S; Michael, R; Söderberg, P; Dillon, J; Zheng, L; Ayala, M

    2000-08-01

    To determine an action spectrum for UV-B radiation and the rat lens and to show the effect of the atmosphere and the cornea on the action spectrum. One eye of young female rats was exposed to 5-nm bandwidths of UV-B radiation (290, 295, 300, 305, 310, and 315 nm). Light scattering of exposed and nonexposed lenses was measured 1 week after irradiation. A quadratic polynomial was fit to the dose-response curve for each wave band. The dose at each wave band that produced a level of light scattering greater than 95% of the nonexposed lenses was defined as the maximum acceptable dose (MAD). Transmittance of the rat cornea was measured with a fiberoptic spectrophotometer. The times to be exposed to the MAD in Stockholm (59.3 degrees N) and La Palma (28 degrees N) were compared. Significant light scattering was detected after UV-B at 295, 300, 305, 310, and 315 nm. The lens was most sensitive to UV-B at 300 nm. Correcting for corneal transmittance showed that the rat lens is at least as sensitive to UV radiation at 295 nm as at 300 nm. The times to be exposed to the MAD at each wave band were greater in Stockholm than in La Palma, and in both locations the theoretical time to be exposed to the MAD was least at 305 nm. After correcting for corneal transmittance, the biological sensitivity of the rat lens to UV-B is at least as great at 295 nm as at 300 nm. After correcting for transmittance by the atmosphere, UV-B at 305 nm is the most likely wave band to injure the rat lens in both Stockholm and La Palma.

  3. The Xenon Test Chamber Q-SUN® for testing realistic tolerances of fungi exposed to simulated full spectrum solar radiation.

    Dias, Luciana P; Araújo, Claudinéia A S; Pupin, Breno; Ferreira, Paulo C; Braga, Gilberto Ú L; Rangel, Drauzio E N

    2018-06-01

    The low survival of insect-pathogenic fungi when used for insect control in agriculture is mainly due to the deleterious effects of ultraviolet radiation and heat from solar irradiation. In this study, conidia of 15 species of entomopathogenic fungi were exposed to simulated full-spectrum solar radiation emitted by a Xenon Test Chamber Q-SUN XE-3-HC 340S (Q-LAB ® Corporation, Westlake, OH, USA), which very closely simulates full-spectrum solar radiation. A dendrogram obtained from cluster analyses, based on lethal time 50 % and 90 % calculated by Probit analyses, separated the fungi into three clusters: cluster 3 contains species with highest tolerance to simulated full-spectrum solar radiation, included Metarhizium acridum, Cladosporium herbarum, and Trichothecium roseum with LT 50  > 200 min irradiation. Cluster 2 contains eight species with moderate UV tolerance: Aschersonia aleyrodis, Isaria fumosorosea, Mariannaea pruinosa, Metarhizium anisopliae, Metarhizium brunneum, Metarhizium robertsii, Simplicillium lanosoniveum, and Torrubiella homopterorum with LT 50 between 120 and 150 min irradiation. The four species in cluster 1 had the lowest UV tolerance: Lecanicillium aphanocladii, Beauveria bassiana, Tolypocladium cylindrosporum, and Tolypocladium inflatum with LT 50  solar radiation before. We conclude that the equipment provided an excellent tool for testing realistic tolerances of fungi to full-spectrum solar radiation of microbial agents for insect biological control in agriculture. Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  4. Comparison of Radiation Transport Codes, HZETRN, HETC and FLUKA, Using the 1956 Webber SPE Spectrum

    Heinbockel, John H.; Slaba, Tony C.; Blattnig, Steve R.; Tripathi, Ram K.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.; Reddell, Brandon; Clowdsley, Martha S.; hide

    2009-01-01

    Protection of astronauts and instrumentation from galactic cosmic rays (GCR) and solar particle events (SPE) in the harsh environment of space is of prime importance in the design of personal shielding, spacec raft, and mission planning. Early entry of radiation constraints into the design process enables optimal shielding strategies, but demands efficient and accurate tools that can be used by design engineers in every phase of an evolving space project. The radiation transport code , HZETRN, is an efficient tool for analyzing the shielding effectiveness of materials exposed to space radiation. In this paper, HZETRN is compared to the Monte Carlo codes HETC-HEDS and FLUKA, for a shield/target configuration comprised of a 20 g/sq cm Aluminum slab in front of a 30 g/cm^2 slab of water exposed to the February 1956 SPE, as mode led by the Webber spectrum. Neutron and proton fluence spectra, as well as dose and dose equivalent values, are compared at various depths in the water target. This study shows that there are many regions where HZETRN agrees with both HETC-HEDS and FLUKA for this shield/target configuration and the SPE environment. However, there are also regions where there are appreciable differences between the three computer c odes.

  5. Solar Flash Sub-Millimeter Wave Range Spectrum Part Radiation Modeling

    V. Yu. Shustikov

    2015-01-01

    model that the reason for raising flux density spectrum of sub-millimeter radio emission of flare is thermal bremsstrahlung plasma radiation with a temperature of 0.1 mK.

  6. Bursts of gravitational radiation from superconducting cosmic strings and the neutrino mass spectrum

    Mosquera Cuesta, Herman J.

    2001-02-01

    Berezinsky, Hnatyk and Vilenkin showed that superconducting cosmic strings could be central engines for cosmological gamma-ray bursts and for producing the neutrino component of ultra-high energy cosmic rays. A consequence of this mechanism would be that a detectable cusp-triggered gravitational wave burst should be release simultaneously with the γ-ray surge. If contemporary measurements of both γ and ν radiation could be made for any particular source, then the cosmological time-delay between them might be useful for putting unprecedently tight bounds on the neutrino mass spectrum. Such measurements could consistently verify or rule out the model since strictly correlated behaviour is expected for the duration of the event and for the time variability of the spectra. (author)

  7. Parametric instability producing broad symmetrical structure in the spectrum of ionospheric heating-induced radiation

    Kuo, S.P.

    1997-01-01

    A four-wave interaction process in which an O-mode electromagnetic pump decays parametrically into a lower hybrid decay mode and two-electron Bernstein sidebands is analyzed. It is shown that the instability can be excited in a spatial region near the electron Bernstein/upper hybrid double resonance and in a narrow pump frequency range slightly below the third harmonic electron cyclotron resonance. The two electron Bernstein sidebands have about the same intensity and thus, produce Broad Symmetrical Structure (BSS) in the emission spectrum after being converted into electromagnetic radiation by scattering off background field-aligned density irregularities. The results also show that the size of the instability zone becomes very small as the pump frequency operates near a cyclotron harmonic higher than the third. Thus, the converted emission will be too weak to be detected. This explains why the BSS feature in the spectrum of stimulated electromagnetic emissions (SEEs) has only been observed in the third harmonic case. copyright 1997 American Institute of Physics

  8. THREE-DIMENSIONAL RADIATIVE TRANSFER MODELING OF THE POLARIZATION OF THE SUN'S CONTINUOUS SPECTRUM

    Bueno, Javier Trujillo; Shchukina, Nataliya

    2009-01-01

    Polarized light provides the most reliable source of information at our disposal for diagnosing the physical properties of astrophysical plasmas, including the three-dimensional (3D) structure of the solar atmosphere. Here we formulate and solve the 3D radiative transfer problem of the linear polarization of the solar continuous radiation, which is principally produced by Rayleigh and Thomson scattering. Our approach takes into account not only the anisotropy of the solar continuum radiation but also the symmetry-breaking effects caused by the horizontal atmospheric inhomogeneities produced by the solar surface convection. We show that such symmetry-breaking effects do produce observable signatures in Q/I and U/I, even at the very center of the solar disk where we observe the forward scattering case, but their detection would require obtaining very high resolution linear polarization images of the solar surface. Without spatial and/or temporal resolution U/I ∼ 0 and the only observable quantity is Q/I, whose wavelength variation at a solar disk position close to the limb has been recently determined semi-empirically. Interestingly, our 3D radiative transfer modeling of the polarization of the Sun's continuous spectrum in a well-known 3D hydrodynamical model of the solar photosphere shows remarkable agreement with the semi-empirical determination, significantly better than that obtained via the use of one-dimensional (1D) atmospheric models. Although this result confirms that the above-mentioned 3D model was indeed a suitable choice for our Hanle-effect estimation of the substantial amount of 'hidden' magnetic energy that is stored in the quiet solar photosphere, we have found however some small discrepancies whose origin may be due to uncertainties in the semi-empirical data and/or in the thermal and density structure of the 3D model. For this reason, we have paid some attention also to other (more familiar) observables, like the center-limb variation of the

  9. Effects of primary recoil (PKA) energy spectrum on radiation damage in fcc metals

    Iwata, Tadao; Iwase, Akihiro

    1997-10-01

    Irradiation effects by different energetic particles such as electrons, various ions and neutrons are compared in fcc metals, particularly in Cu and Ni. It is discussed on the statistical consideration that the logarithm of the so-called PKA median energy, log T 1/2 , is a good representative to characterize the primary recoil (i.e. PKA) energy spectrum with the resultant defect production. For the irradiations of electrons, various ions and neutrons to Cu and Ni, fundamental physical quantities such as the fraction of stage I recovery, the defect production cross sections and the radiation annealing cross sections can be well scaled as a function of log T 1/2 , if the effects of the electron excitation caused by irradiating ions are excluded. Namely, all data of the respective physical quantity lie on a single continuous curve as a function of log T 1/2 . This characteristic curve is utilized to predict the damage accumulation (i.e. defect concentration) as a function of dpa in Cu and Ni with the PKA median energy as a parameter. (author)

  10. Mutation of Haemophilus influenzae transforming DNA in vitro with near-ultraviolet radiation: action spectrum

    Cabrera-Juarez, E; Setlow, J K [Escuela Nacional de Ciencias Biologicas, Mexico City. Dept. de Bioquimica; Oak Ridge National Lab., Tenn. (USA). Biology Div.)

    1976-05-01

    Mutations were produced in purified transforming DNA from Haemophilus influenzae by near UV radiation and were assayed as mutants among cells transformed with irradiated DNA. The maximum efficiency of mutation induction was at around 334 nm, and the efficiency dropped off steeply at lower and higher wavelengths. The difference between the action spectrum for mutation and that for the oxygen-independent inactivation of transforming DNA, which had a shoulder at 365 nm, indicates that there are different lesions involved in the inactivating and mutagenic effects of near-UV. The presence of histidine during irradiation enhanced the mutagenic effect at 334 and 365 nm, although it protected against inactivation at 365 nm. The effective near-UV wavelengths for in vitro mutation are to some extent the same as the effective wavelengths for mutation in vivo reported previously. These findings indicate that mutations are produced in vivo by near-UV with DNA as the primary target molecule rather than by a secondary non-photochemical reaction between DNA and some other cell component.

  11. Effects of primary recoil (PKA) energy spectrum on radiation damage in fcc metals

    Iwata, Tadao; Iwase, Akihiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-10-01

    Irradiation effects by different energetic particles such as electrons, various ions and neutrons are compared in fcc metals, particularly in Cu and Ni. It is discussed on the statistical consideration that the logarithm of the so-called PKA median energy, log T{sub 1/2}, is a good representative to characterize the primary recoil (i.e. PKA) energy spectrum with the resultant defect production. For the irradiations of electrons, various ions and neutrons to Cu and Ni, fundamental physical quantities such as the fraction of stage I recovery, the defect production cross sections and the radiation annealing cross sections can be well scaled as a function of log T{sub 1/2}, if the effects of the electron excitation caused by irradiating ions are excluded. Namely, all data of the respective physical quantity lie on a single continuous curve as a function of log T{sub 1/2}. This characteristic curve is utilized to predict the damage accumulation (i.e. defect concentration) as a function of dpa in Cu and Ni with the PKA median energy as a parameter. (author)

  12. Modeling the relationship between photosynthetically active radiation and global horizontal irradiance using singular spectrum analysis

    Zempila, Melina-Maria; Taylor, Michael; Bais, Alkiviadis; Kazadzis, Stelios

    2016-01-01

    We report on the construction of generic models to calculate photosynthetically active radiation (PAR) from global horizontal irradiance (GHI), and vice versa. Our study took place at stations of the Greek UV network (UVNET) and the Hellenic solar energy network (HNSE) with measurements from NILU-UV multi-filter radiometers and CM pyranometers, chosen due to their long (≈1 M record/site) high temporal resolution (≈1 min) record that captures a broad range of atmospheric environments and cloudiness conditions. The uncertainty of the PAR measurements is quantified to be ±6.5% while the uncertainty involved in GHI measurements is up to ≈±7% according to the manufacturer. We show how multi-linear regression and nonlinear neural network (NN) models, trained at a calibration site (Thessaloniki) can be made generic provided that the input–output time series are processed with multi-channel singular spectrum analysis (M-SSA). Without M-SSA, both linear and nonlinear models perform well only locally. M-SSA with 50 time-lags is found to be sufficient for identification of trend, periodic and noise components in aerosol, cloud parameters and irradiance, and to construct regularized noise models of PAR from GHI irradiances. Reconstructed PAR and GHI time series capture ≈95% of the variance of the cross-validated target measurements and have median absolute percentage errors <2%. The intra-site median absolute error of M-SSA processed models were ≈8.2±1.7 W/m"2 for PAR and ≈9.2±4.2 W/m"2 for GHI. When applying the models trained at Thessaloniki to other stations, the average absolute mean bias between the model estimates and measured values was found to be ≈1.2 W/m"2 for PAR and ≈0.8 W/m"2 for GHI. For the models, percentage errors are well within the uncertainty of the measurements at all sites. Generic NN models were found to perform marginally better than their linear counterparts. - Highlights: • Generic linear regression and nonlinear neural network

  13. Power Difference in Spectrum of Sound Radiation before and after Break of Phantom by Piezoelectric Extracorporeal Shock Wave Lithotriptor

    Kanai, Hiroshi; Jang, Yun-Seok; Chubachi, Noriyoshi; Tanahashi, Yoshikatsu

    1994-05-01

    This paper investigates the difference in the spectrum of sound radiated before and after the break of a phantom at a focal point of the piezoelectric extracorporeal shock wave lithotriptor (ESWL) in order to identify the break time or to examine whether a calculus exists exactly at the focal point or not. From the preliminary experiments using a piece of chalk as a phantom of a calculus to measure the sound radiated when impact is applied to the chalk by an impact hammer, it is found that the bending vibration component of the vibration is exhibited in the spectrum of sound. However, for small-sized chalk shorter than 3 cm, the peak frequency of the bending vibration is higher than 20 kHz. From the experiments using a piezoeletric ESWL, it is found that there is clear difference in the power spectra among the sound radiated before the break, that radiated just after the break in the breaking process, and that radiated when the chalk does not exist at the focal point of the ESWL. These characteristics will be effective for the examination of the existence of the calculus at the focal point.

  14. Computing the spectrum of black hole radiation in the presence of high frequency dispersion: an analytical approach

    Corley, Steven

    1997-01-01

    We present a method for computing the spectrum of black hole radiation of a scalar field satisfying a wave equation with high frequency dispersion. The method involves a combination of Laplace transform and WKB techniques for finding approximate solutions to ordinary differential equations. The modified wave equation is obtained by adding a higher order derivative term suppressed by powers of a fundamental momentum scale $k_0$ to the ordinary wave equation. Depending on the sign of this new t...

  15. The cosmic microwave background radiation power spectrum as a random bit generator for symmetric- and asymmetric-key cryptography.

    Lee, Jeffrey S; Cleaver, Gerald B

    2017-10-01

    In this note, the Cosmic Microwave Background (CMB) Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n) random key matrix for a Vernam cipher is established.

  16. Spectral properties of plant leaves pertaining to urban landscape design of broad-spectrum solar ultraviolet radiation reduction

    Yoshimura, Haruka; Zhu, Hui; Wu, Yunying; Ma, Ruijun

    2010-03-01

    Human exposure to harmful ultraviolet (UV) radiation has important public health implications. Actual human exposure to solar UV radiation depends on ambient UV irradiance, and the latter is influenced by ground reflection. In urban areas with higher reflectivity, UV exposure occurs routinely. To discover the solar UV radiation regulation mechanism of vegetation, the spectral reflectance and transmittance of plant leaves were measured with a spectrophotometer. Typically, higher plants have low leaf reflectance (around 5%) and essentially zero transmittance throughout the UV region regardless of plant species and seasonal change. Accordingly, incident UV radiation decreases to 5% by being reflected and is reduced to zero by passing through a leaf. Therefore, stratified structures of vegetation are working as another terminator of UV rays, protecting whole terrestrial ecosystems, while vegetation at waterfronts contributes to protect aquatic ecosystems. It is possible to protect the human population from harmful UV radiation by urban landscape design of tree shade and the botanical environment. Even thin but uniformly distributed canopy is effective in attenuating UV radiation. To intercept diffuse radiation, UV screening by vertical structures such as hedges should be considered. Reflectivity of vegetation is around 2%, as foliage surfaces reduce incident UV radiation via reflection, while also eliminating it by transmittance. Accordingly, vegetation reduces incident UV radiation to around 2% by reflection. Vegetation influence on ambient UV radiation is broad-spectrum throughout the UV region. Only trees provide cool UV protective shade. Urban landscapes aimed at abating urban heat islands integrated with a reduction of human UV over-exposure would contribute to mitigation of climate change.

  17. Spectrum of relativistic radiation from electric charges and dipoles as they fall freely into a black hole

    Shatskiy, A. A., E-mail: shatskiy@asc.rssi.ru; Novikov, I. D.; Lipatova, L. N. [Russian Academy of Sciences, Astrospace Center, Lebedev Physical Institute (Russian Federation)

    2013-06-15

    The motion of electric charges and dipoles falling radially and freely into a Schwarzschild black hole is considered. The inverse effect of the electromagnetic fields on the black hole is neglected. Since the dipole is assumed to be a point particle, the deformation due to the action of tidal forces on it is neglected. According to the theorem stating that 'black holes have no hair', the multipole electromagnetic fields should be completely radiated as a multipole falls into a black hole. The electromagnetic radiation power spectrum for these multipoles (a monopole and a dipole) has been found. Differences have been found in the spectra for different orientations of the falling dipole. A general method has been developed to find the radiated multipole electromagnetic fields for multipoles (including higher-order multipoles-quadrupoles, etc.) falling freely into a black hole. The calculated electromagnetic spectra can be compared with observational data from stellar-mass and smaller black holes.

  18. Measurement of the Radiative Decay of the Longest-Lived Level in the Fe XVII Spectrum

    Brown, Gregory V.; Beiersdorfer, Peter; Träbert, Elmar

    2014-08-01

    The Fe XVII emission spectrum comprises several very prominent X-ray lines that play an important role in the study of many astrophysical objects. Among the Fe XVII X-ray lines, those emanating from a 3s level, i.e., lines 3F, 3G, and M2, invariably appear too strong compared to the lines emanating from a 3d level, i.e., lines 3C and 3D, when compared to theory. Two of the four 3s levels are metastable, which means they have a rather long radiative decay time compared to collisional processes. The decay rate of the 2p^53s J=2 level has recently been measured at the Livermore EBIT facility [J. R. Crespo López-Urrutia and P. Beiersdorfer, ApJ 721, 576 (2010)], and the scatter of predictions by a factor of 1.7 has been reduced to a measurement uncertainty of merely a few percent. Even longer-lived is the J=0 level of the same 2p^53s configuration. Theory predicts an exclusive magnetic dipole decay to the lowest J=1 level of the same 2p^53s configuration, i.e. to the upper level of line 3G. There appear to be fewer predictions for this rate than for the rates associated with the other Fe XVII levels. Various calculations yield a decay rate near 16 000 s-1 for this level (or a level lifetime near 63 µs). If this value is correct, electron-impact collisions affect line ratios tied to this level at densities between about 10^10 cm-3 and 10^13 cm-3, that is, exactly at many coronal densities of present interest. We have used the Livermore EBIT facility to measure the M1 decay rate of the 2p^53s J=0 level. We find a value commensurate with the value predicted by the Flexible Atomic Code.Work performed under auspices of U.S. D.o.E. by DE-AC52-07NA27344 and supported by NASA's APRA progam under Interagency Agreement NNG13WF991.

  19. Upgrades of DARWIN, a dose and spectrum monitoring system applicable to various types of radiation over wide energy ranges

    Sato, Tatsuhiko; Satoh, Daiki; Endo, Akira; Shigyo, Nobuhiro; Watanabe, Fusao; Sakurai, Hiroki; Arai, Yoichi

    2011-05-01

    A dose and spectrum monitoring system applicable to neutrons, photons and muons over wide ranges of energy, designated as DARWIN, has been developed for radiological protection in high-energy accelerator facilities. DARWIN consists of a phoswitch-type scintillation detector, a data-acquisition (DAQ) module for digital waveform analysis, and a personal computer equipped with a graphical-user-interface (GUI) program for controlling the system. The system was recently upgraded by introducing an original DAQ module based on a field programmable gate array, FPGA, and also by adding a function for estimating neutron and photon spectra based on an unfolding technique without requiring any specific scientific background of the user. The performance of the upgraded DARWIN was examined in various radiation fields, including an operational field in J-PARC. The experiments revealed that the dose rates and spectra measured by the upgraded DARWIN are quite reasonable, even in radiation fields with peak structures in terms of both spectrum and time variation. These results clearly demonstrate the usefulness of DARWIN for improving radiation safety in high-energy accelerator facilities.

  20. Upgrades of DARWIN, a dose and spectrum monitoring system applicable to various types of radiation over wide energy ranges

    Sato, Tatsuhiko; Satoh, Daiki; Endo, Akira; Shigyo, Nobuhiro; Watanabe, Fusao; Sakurai, Hiroki; Arai, Yoichi

    2011-01-01

    A dose and spectrum monitoring system applicable to neutrons, photons and muons over wide ranges of energy, designated as DARWIN, has been developed for radiological protection in high-energy accelerator facilities. DARWIN consists of a phoswitch-type scintillation detector, a data-acquisition (DAQ) module for digital waveform analysis, and a personal computer equipped with a graphical-user-interface (GUI) program for controlling the system. The system was recently upgraded by introducing an original DAQ module based on a field programmable gate array, FPGA, and also by adding a function for estimating neutron and photon spectra based on an unfolding technique without requiring any specific scientific background of the user. The performance of the upgraded DARWIN was examined in various radiation fields, including an operational field in J-PARC. The experiments revealed that the dose rates and spectra measured by the upgraded DARWIN are quite reasonable, even in radiation fields with peak structures in terms of both spectrum and time variation. These results clearly demonstrate the usefulness of DARWIN for improving radiation safety in high-energy accelerator facilities.

  1. Production of a narrow band of 0.511-MeV radiation by use of the PHERMEX bremsstrahlung spectrum

    Stroscio, M.A.

    1976-06-01

    The pair production cross section is numerically integrated over a typical PHERMEX bremsstrahlung spectrum to obtain the probability of pair production in a target of nuclear charge Z, and density rho. The pair production cross section used herein is only approximate in that it neglects screening, neglects the Coulomb field for the emerging pair (first Born approximation), and neglects pair production by atomic electrons. In spite of these approximations, an order-of-magnitude estimate of the amount of 0.511-MeV radiation produced by a typical pulse is still given

  2. The cosmic microwave background radiation power spectrum as a random bit generator for symmetric- and asymmetric-key cryptography

    Jeffrey S. Lee

    2017-10-01

    Full Text Available In this note, the Cosmic Microwave Background (CMB Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n random key matrix for a Vernam cipher is established. Keywords: Particle physics, Computer science, Mathematics, Astrophysics

  3. Spectrum of perturbations arising in a nonsingular model of the Universe with the initial de Sitter stage and the anisotropy of the relic radiation

    Starobinskij, A.A.

    1983-01-01

    Spectrum of primary adiabatic perturbations and gravitational waves formed in the proposed earlier by the author nonsingular cosmological model with the initial quantum de Sitter stage generated by gravitational vacuum polarization is calculated. The spectrum of gravitational waves appears to be flat, the spectrum of adiabatic perturbations is close to the flat one. The large-scale anisotropy of the temperature T of the relic electromagnetic radiation due to these fluctuations is found. It is shown that the most promising way to detect the anisotropy in the case of a flat perturbation spectrum is the investigation of correlations of ΔT/T at the angles of 5 deg - 10 deg

  4. Spectrum of the cosmic background radiation: early and recent measurements from the White Mountain Research Station

    Smoot, G.F.

    1985-09-01

    The White Mountain Research Station has provided a support facility at a high, dry, radio-quiet site for measurements that have established the blackbody character of the cosmic microwave background radiation. This finding has confirmed the interpretation of the radiation as a relic of the primeval fireball and helped to establish the hot Big Bang theory as the standard cosmological model

  5. Geant4 simulation of ion chambers response to 60Co spectrum of LNMRI/IRD Shepherd 81-14D Radiator

    Queiroz Filho, P. P.; Da Silva, C. N. M.

    2018-03-01

    The National Ionizing Radiation Metrology Laboratory of the Radioprotection and Dosimetry Institute (LNMRI / IRD) has recently acquired a Shepherd 81-14D Radiator. In this work we simulate, using Geant4, the behavior with the inverse square law radiation for 3 models of PTW spherical chambers used in radioprotection, a relevant information to planning the measurements. We did the corrections for the attenuation and scattering in the air for each distance, where we used the 60Co spectrum simulated previously.

  6. Spectrum of chromosomal aberrations in peripheral lymphocytes of hospital workers occupationally exposed to low doses of ionizing radiation

    Maffei, Francesca; Angelini, Sabrina; Forti, Giorgio Cantelli; Violante, Francesco S.; Lodi, Vittorio; Mattioli, Stefano; Hrelia, Patrizia

    2004-01-01

    Chromosome aberrations frequency was estimated in peripheral lymphocytes from hospital workers occupationally exposed to low levels of ionizing radiation and controls. Chromosome aberrations yield was analyzed by considering the effects of dose equivalent of ionizing radiation over time, and of confounding factors, such as age, gender and smoking status. Frequencies of aberrant cells and chromosome breaks were higher in exposed workers than in controls (P=0.007, and P=0.001, respectively). Seven dicentric aberrations were detected in the exposed group and only three in controls, but the mean frequencies were not significantly different. The dose equivalent to whole body of ionizing radiation (Hwb) did appear to influence the spectrum of chromosomal aberrations when the exposed workers were subdivided by a cut off at 50 mSv. The frequencies of chromosome breaks in both subgroups of workers were significantly higher than in controls (≤50 mSv, P=0.041; >50 mSv, P=0.018). On the other hand, the frequency of chromatid breaks observed in workers with Hwb >50 mSv was significantly higher than in controls (P=0.015) or workers with Hwb ≤50 mSv (P=0.046). Regarding the influence of confounding factors on genetic damage, smoking status and female gender seem to influence the increase in chromosome aberration frequencies in the study population. Overall, these results suggested that chromosome breaks might provide a good marker for assessing genetic damage in populations exposed to low levels of ionizing radiation

  7. UTILITY OF A WIDE SPECTRUM LIGHT METER AS AN UNDERWATER SENSOR OF PHOTOSYNTHETICALLY ACTIVE RADIATION (PAR)

    The strong attenuation of infra red wavelengths (>700 nm) in coastal waters is suggestive that some instruments with broad spectral responses might be useful, inexpensive substitutes for PAR sensors in studies of estuarine plant dynamics. Wide spectrum (350-1100 nm) light intensi...

  8. Monte-Carlo study on primary knock-on atom energy spectrum produced by neutron radiation

    Zhou Wei; Liu Yongkang; Deng Yongjun; Ma Jimin

    2012-01-01

    Computational method on energy distribution of primary knock-on atom (PKA) produced by neutron radiation was built in the paper. Based on the DBCN card in MCNP, reaction position, reaction type and energy transfer between neutrons and atoms were recorded. According to statistic of these data, energy and space distributions of PKAs were obtained. The method resolves preferably randomicity of random number and efficiency of random sampling computation. The results show small statistical fluctuation and well statistical. Three-dimensional figure of energy and space distribution of PKAs were obtained, which would be important to evaluate radiation capability of materials and study radiation damage by neutrons. (authors)

  9. Pulse shape and spectrum of coherent diffraction-limited transition radiation from electron beams

    van Tilborg, J.; Schroeder, C.B.; Esarey, E.; Leemans, W.P.

    2003-12-20

    The electric field in the temporal and spectral domain of coherent diffraction-limited transition radiation is studied. An electron bunch, with arbitrary longitudinal momentum distribution, propagating at normal incidence to a sharp metal-vacuum boundary with finite transverse dimension is considered. A general expression for the spatiotemporal electric field of the transition radiation is derived, and closed-form solutions for several special cases are given. The influence of parameters such as radial boundary size, electron momentum distribution, and angle of observation on the waveform (e.g., radiation pulse length and amplitude) are discussed. For a Gaussian electron bunch, the coherent radiation waveform is shown to have a single-cycle profile. Application to a novel THz source based on a laser-driven accelerator is discussed.

  10. Probing reionization with the cross-power spectrum of 21 cm and near-infrared radiation backgrounds

    Mao, Xiao-Chun, E-mail: xcmao@bao.ac.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-08-01

    The cross-correlation between the 21 cm emission from the high-redshift intergalactic medium and the near-infrared (NIR) background light from high-redshift galaxies promises to be a powerful probe of cosmic reionization. In this paper, we investigate the cross-power spectrum during the epoch of reionization. We employ an improved halo approach to derive the distribution of the density field and consider two stellar populations in the star formation model: metal-free stars and metal-poor stars. The reionization history is further generated to be consistent with the electron-scattering optical depth from cosmic microwave background measurements. Then, the intensity of the NIR background is estimated by collecting emission from stars in first-light galaxies. On large scales, we find that the 21 cm and NIR radiation backgrounds are positively correlated during the very early stages of reionization. However, these two radiation backgrounds quickly become anti-correlated as reionization proceeds. The maximum absolute value of the cross-power spectrum is |Δ{sub 21,NIR}{sup 2}|∼10{sup −4} mK nW m{sup –2} sr{sup –1}, reached at ℓ ∼ 1000 when the mean fraction of ionized hydrogen is x-bar{sub i}∼0.9. We find that Square Kilometer Array can measure the 21 cm-NIR cross-power spectrum in conjunction with mild extensions to the existing CIBER survey, provided that the integration time independently adds up to 1000 and 1 hr for 21 cm and NIR observations, and that the sky coverage fraction of the CIBER survey is extended from 4 × 10{sup –4} to 0.1. Measuring the cross-correlation signal as a function of redshift provides valuable information on reionization and helps confirm the origin of the 'missing' NIR background.

  11. Radiation damage in bioapatites: the ESR spectrum of irradiated dental enamel revisited

    Rossi, A.M.; Poupeau, G.

    1990-01-01

    We have studied the ESR spectrum of enamel from fossil vertebrate teeth perpendicular = 2.0026 and g longitudinal = 1.9975; and species B, having an orthorhombic symmetry with g 1 = 2.0032, g 2 = 2.0018 and g 3 = 1.9975. Center A is probably located at an OH - site of the hydroxyapatite lattice. Centre B could be a distorted centre A. (author)

  12. Development of optical spectrum acquisition with spectrophotometer for characterization of optical radiation sources

    Solano Vargas, Alvaro

    2013-01-01

    An improved process of the data acquisition system is developed with Pasco 750 interface and Pasco OS-8539 spectrophotometer. The optical spectrum and color temperature of incandescent sources available are obtained from the Laboratorio de Fotonica y Tecnologia Laser Aplicada. The procedures developed in the project are recommended to collect data and analyze results. The purchase of a new Software and the interface of Pasco is recommended to have a better operation and update [es

  13. Laboratory simulation of interplanetary ultraviolet radiation (broad spectrum) and its effects on Deinococcus radiodurans

    Paulino-Lima, Ivan Gláucio; Pilling, Sérgio; Janot-Pacheco, Eduardo; de Brito, Arnaldo Naves; Barbosa, João Alexandre Ribeiro Gonçalves; Leitão, Alvaro Costa; Lage, Claudia de Alencar Santos

    2010-08-01

    The radiation-resistant bacterium Deinococcus radiodurans was exposed to a simulated interplanetary UV radiation at the Brazilian Synchrotron Light Laboratory (LNLS). Bacterial samples were irradiated on different substrates to investigate the influence of surface relief on cell survival. The effects of cell multi-layers were also investigated. The ratio of viable microorganisms remained virtually the same (average 2%) for integrated doses from 1.2 to 12 kJ m -2, corresponding to 16 h of irradiation at most. The asymptotic profiles of the curves, clearly connected to a shielding effect provided by multi-layering cells on a cavitary substrate (carbon tape), means that the inactivation rate may not change significantly along extended periods of exposure to radiation. Such high survival rates reinforce the possibility of an interplanetary transfer of viable microbes.

  14. Examination for optimization of synchrotron radiation spectrum for the x ray depth lithography

    Dany, Raimund

    1992-06-01

    The effect of reducing the vertical distribution of synchrotron radiation on its spectral distribution is examined through resin irradiation. The resulting filter effect is compared to that of absorption filters. Transmission coefficients of titanium, gold, and polyamide were calculated from linear absorption coefficients with the Beer law. The use of a diaphragm in X-ray depth lithography, which is the first step of the LIGA (Lithography Galvanoforming Molding) process, is discussed. A calorimetric device for determining the synchrotron radiation power and distribution was developed and tested. Measurements at the ELSA storage ring show a strong dependence of the vertical emittance on the electron current.

  15. Exclusion of UV-B radiation from normal solar spectrum on the growth of mung bean and maize

    Pal, M.; Sharma, A.; Abrol, Y.P.; Sengupta, U.K.

    1997-01-01

    The increase in UV-B radiation due to depletion of the ozone layer has potentially harmful effects on plant growth and performance. The bulk of these studies conducted in growth chambers, greenhouses or in the field use different types of exposure systems which may be responsible for differences in the sensitivity of a crop to UV-B radiation. A field study using selective filters to remove the UV-B portion of the solar spectrum was conducted with mung bean (a dicotyledonous C 3 plant) and maize (a monocotyledonous C 4 plant) to determine the sensitivity of these crop plants to ambient UV-B levels without disturbing the microenvironment. Mung bean was found to be sensitive to ambient UV-B levels in terms of leaf area development, plant height attained and net photosynthesis, while maize was found to be unaffected by ambient UV-B levels (22.8 |GmW cm −2 nm −1 ) found in Delhi, India (28°38′N, 77°13′E). The level of ambient UV-B radiation thus appears to be inhibitory for optimal growth of plants, especially dicotyledonous mung bean. (author)

  16. Comparison of noise power spectrum methodologies in measurements by using various electronic portal imaging devices in radiation therapy

    Son, Soon Yong [Dept. of Radiological Technology, Wonkwang Health Science University, Iksan (Korea, Republic of); Choi, Kwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Technology, Baekseok Culture University College, Cheonan (Korea, Republic of); Kwon, Kyung Tae [Dep. of Radiological Technology, Dongnam Health University, Suwon (Korea, Republic of); Kim, Ki Won [Dept. of Radiology, Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Lee, Young Ah; Son, Jin Hyun; Min, Jung Whan [Shingu University College, Sungnam (Korea, Republic of)

    2016-03-15

    The noise power spectrum (NPS) is one of the most general methods for measuring the noise amplitude and the quality of an image acquired from a uniform radiation field. The purpose of this study was to compare different NPS methodologies by using megavoltage X-ray energies. The NPS evaluation methods in diagnostic radiation were applied to therapy using the International Electro-technical Commission standard (IEC 62220-1). Various radiation therapy (RT) devices such as TrueBeamTM(Varian), BEAMVIEWPLUS(Siemens), iViewGT(Elekta) and ClinacR iX (Varian) were used. In order to measure the region of interest (ROI) of the NPS, we used the following four factors: the overlapping impact, the non-overlapping impact, the flatness and penumbra. As for NPS results, iViewGT(Elekta) had the higher amplitude of noise, compared to BEAMVIEWPLUS (Siemens), TrueBeamTM(Varian) flattening filter, ClinacRiXaS1000(Varian) and TrueBeamTM(Varian) flattening filter free. The present study revealed that various factors could be employed to produce megavoltage imaging (MVI) of the NPS and as a baseline standard for NPS methodologies control in MVI.

  17. Fast and Accurate Hybrid Stream PCRTMSOLAR Radiative Transfer Model for Reflected Solar Spectrum Simulation in the Cloudy Atmosphere

    Yang, Qiguang; Liu, Xu; Wu, Wan; Kizer, Susan; Baize, Rosemary R.

    2016-01-01

    A hybrid stream PCRTM-SOLAR model has been proposed for fast and accurate radiative transfer simulation. It calculates the reflected solar (RS) radiances with a fast coarse way and then, with the help of a pre-saved matrix, transforms the results to obtain the desired high accurate RS spectrum. The methodology has been demonstrated with the hybrid stream discrete ordinate (HSDO) radiative transfer (RT) model. The HSDO method calculates the monochromatic radiances using a 4-stream discrete ordinate method, where only a small number of monochromatic radiances are simulated with both 4-stream and a larger N-stream (N = 16) discrete ordinate RT algorithm. The accuracy of the obtained channel radiance is comparable to the result from N-stream moderate resolution atmospheric transmission version 5 (MODTRAN5). The root-mean-square errors are usually less than 5x10(exp -4) mW/sq cm/sr/cm. The computational speed is three to four-orders of magnitude faster than the medium speed correlated-k option MODTRAN5. This method is very efficient to simulate thousands of RS spectra under multi-layer clouds/aerosols and solar radiation conditions for climate change study and numerical weather prediction applications.

  18. Application of correlation techniques to the angular spectrum of scattered radiation from tokamak plasmas

    Nazikian, R.

    1990-01-01

    In the limit of the first Born approximation for a partially coherent secondary source consisting of a spatially random plasma illuminated by a coherent plane wave, it is shown that the spectral coherence of the scattered radiation conveys information on the three-dimensional intensity distribution of the secondary source

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

    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.

  20. Frequency and spectrum of chlorophyll-deficient mutations in rice after treatment with radiation and alkylating agents

    Bhan, A.K.; Kaul, M.L.H.

    1976-01-01

    Three varieties of rice were treated with gamma rays and two alkylating agents EMS and DES, separately and in combinations, with a view to finding out the frequency and spectrum of chlorophyll mutations in relation to the genotype and the nature of the mutagen. Chlorophyll mutation frequency was enhanced with increasing dose but dropped at very high doses (doses that induced over 90% seeding lethality in M 1 ). The fall was attributed to either the increased mutated sector and diplontic selection after exposure to very high doses or relatively high resistance of some of the seeds. Among chlorophyll mutants in M 2 induced by radiations as well as alkylating agents, the albina type formed the majority class. EMS induced a significantly higher proportion of albinas than did gamma rays

  1. Modeling of the Signal Formation in SiC Sensors for Measurements of the Radiation Spectrum in Nuclear Energy

    Krolikowski, Igor P.

    2013-06-01

    The modeling methodology of the signal formation in SiC sensors is presented. The modeling uses two approaches: the first one is the integrated approach whereas the second is the analytical approach. The sensor response is obtained from both approaches: this is the usual solution of the forward problem. Moreover, the response function of the sensor is evaluated by means of the analytical approach and it can be used to solve the inverse problem: recovering the primary radiation spectrum using the response of the sensor. Additionally, the response function returns information about the signal formation in the sensor such as the shape of the response formed by particles with a specific energy. Results obtained by simulations are then compared with experimental data. (authors)

  2. The application of correlation techniques to the angular spectrum of scattered radiation from tokamak plasmas

    Nazikian, R.

    1990-07-01

    In the limit of the first Born approximation for a partially coherent secondary source, consisting of a spatially random plasma illuminated by a coherent plane wave, it is shown that the spectral coherence of the scattered radiation as measured on an arbitrary plane beyond the scatterer conveys information on the three dimensional intensity distribution of the random source. By defining a new two point statistical measure of the random field, closely related to the cross spectral density, we show that the fluctuation amplitude of the random source along the direction of the incident plane wave may by recovered from the measurement of the scattered radiation. The application of cross spectral techniques to fluctuation studies on tokamaks is considered. 7 refs

  3. The absorption and emission spectrum of radiative cooling galactic fountain gas

    Benjamin, Robert A.; Shapiro, Paul R.

    1993-01-01

    We have calculated the time-dependent, nonequilibrium thermal and ionization history of gas cooling radiatively from 10(exp 6) K in a one-dimensional, planar, steady-state flow model of the galactic fountain, including the effects of radiative transfer. Our previous optically thin calculations explored the effects of photoionization on such a flow and demonstrated that self-ionization was sufficient to cause the flow to match the observed galactic halo column densities of C 4, Si 4, and N 5 and UV emission from C 4 and O 3 in the constant density (isochoric) limit, which corresponded to cooling regions homogeneous on scales D less than or approximately equal to 1 kpc. Our new calculations which take full account of radiative transfer confirm the importance of self-ionization in enabling such a flow to match the data but allow a much larger range for cooling region sizes, i.e. D(sub 0) greater than or approximately equal to 15 pc. For an initial flow velocity v(sub 0) approximately equal to 100 km/s, comparable to the sound speed of a 10(exp 6) K gas, the initial density is found to be n(sub h,0) is approximately 2 x 10(exp -2) cm(exp -3), in reasonable agreement with other observation estimates, and D(sub 0) is approximately equal to 40 pc. We also compare predicted H(alpha) fluxes, UV line emission, and broadband x-ray fluxes with observed values. One dimensional numerical hydrodynamical calculations including the effects of radiative cooling are also presented.

  4. Understanding the dosimetric powder EPR spectrum of sucrose by identification of the stable radiation-induced radicals

    Vrielinck, H.; Vanhaelewyn, G.; Matthys, P.; Callens, F.; Kusakovskij, J.

    2014-01-01

    Sucrose, the main component of table sugar, present in nearly every household and quite radiation sensitive, is considered as an interesting emergency dosemeter. Another application of radiation-induced radicals in sugars is the detection of irradiation in sugar-containing foodstuffs. The complexity of electron paramagnetic resonance (EPR) spectra of radicals in these materials, as a result of many hyperfine interactions and the multi-compositeness of the spectra of individual sugars, complicate dose assessment and the improvement of protocols for control and identification of irradiated sugar-containing foodstuffs using EPR. A thorough understanding of the EPR spectrum of individual irradiated sugars is desirable when one wants to reliably use them in a wide variety of dosimetric applications. Recently, the dominant room temperature stable radicals in irradiated sucrose have been thoroughly characterised using EPR, electron nuclear double resonance (ENDOR) and ENDOR-induced EPR. These radicals were structurally identified by comparing their proton hyperfine and g-tensors with the results of Density Functional Theory calculations for test radical structures. In this paper, the authors use the spin Hamiltonian parameters determined in these studies to simulate powder EPR spectra at the standard X-band (9.5 GHz), commonly used in applications, and at higher frequencies, up to J-band (285 GHz), rendering spectra with higher resolution. A few pitfalls in the simulation process are highlighted. The results indicate that the major part of the dosimetric spectrum can be understood in terms of three dominant radicals, but as-yet unidentified radicals also contribute in a non-negligible way. (authors)

  5. Influence of the primary recoil spectrum on radiation-induced segregation in nickel-silicon

    Averback, R.S.; Rehn, L.E.; Wiedersich, H.; Cook, R.E.

    1980-01-01

    Radiation induced segregation in Ni-12.7% Si has been examined for 1.5 MeV He, 2.0 MeV Li, and 2.75 MeV Kr irradiations. A method to simultaneously damage and analyze the specimens during light-ion irradiation is described. The amount of segregation was determined by using Rutherford backscattering spectrometry to measure the thickness of the γ' layer which develops at the surface. Substantially less segregation of Si to the surface is observed for the Kr irradiation than for the light-ion irradiations at 520 0 C

  6. Gamma Radiation from Fission Fragments Experimental Apparatus-Mass Spectrum Resolution

    Higbie, Jack

    1969-08-15

    The gamma-radiation from fission fragments was studied as a function of the fragment mass. The mass was determined from the fragment energies using solid state detectors. The mass resolution which can be achieved by this method is treated in detail. The average initial fragment mass and the initial mass resolution is calculated as a function of the measured (apparent) mass yield for three different thicknesses of the fissile material deposit. This treatment gives a clear indication of those factors most important for good mass resolution work. A detailed description of the experimental apparatus is given in the appendices.

  7. Spectrum and Frequency of Mutations Induced by Gamma Radiations in Three Varieties of Nigerian Sesame (Sesamum indicum L.

    Muhammad Liman MUHAMMAD

    2018-03-01

    Full Text Available Insufficient genetic variability is one of the major problems of plant breeding programmes, especially in sesame. Gamma radiation has been reported to be very effective in creating genetic variability in plants. Three varieties of Nigerian sesame were assessed for spectrum and frequency of mutation induced by Gamma radiations in M1 and M2 generations. The varieties (NCRIBEN-04E, NCRIBEN-01M and NCRIBEN-03L were treated with four different doses of gamma rays (250, 350, 450 and 550 Gy. The treated and untreated seeds (control were sown in planting bags (under field condition to raise M1 plants. Four treatments: V1D5, V2D3, V3D2 and V3D4 (from M1 plants were selected and bulked to obtain M2 populations. The results of M1 revealed four mutant fruit traits: multicarpellate capsule, multiple capsule per leaf axil, indehiscent capsule and terminal capsules. The highest frequencies of the traits in M1 generation were 2.50×10-2, 9.17×10-2, 1.67×10-2and3.33×10-2 respectively. The highest branching (7 was from NCRIBEN-01M, while the least (2 was from NCRIBEN-04E. The M2 plants were grouped into eight M2 lines. The dose range (250-550 Gy was proved to be effective in inducing viable mutations in sesame.

  8. Action spectrum and mechanisms of UV radiation-induced injury in lupus erythematosus

    Kochevar, I.E.

    1985-01-01

    Photosensitivity associated with lupus erythematosus (LE) is well established. The photobiologic basis for this abnormal response to ultraviolet radiation, however, has not been determined. This paper summarizes the criteria for elucidating possible photobiologic mechanisms and reviews the literature relevant to the mechanism of photosensitivity in LE. In patients with LE, photosensitivity to wavelengths shorter than 320 nm has been demonstrated; wavelengths longer than 320 nm have not been adequately evaluated. DNA is a possible chromophore for photosensitivity below 320 nm. UV irradiation of skin produces thymine photodimers in DNA. UV-irradiated DNA is more antigenic than native DNA and the antigenicity of UV-irradiated DNA has been proposed, but not proven, to be involved in the development of clinical lesions. UV irradiation of mice previously injected with anti-UV-DNA antibodies produces Ig deposition and complement fixation that appears to be similar to the changes seen in lupus lesions. Antibodies to UV-irradiated DNA occur in the serum of LE patients although a correlation between antibody titers and photosensitivity was not observed. Defective repair of UV-induced DNA damage does not appear to be a mechanism for the photosensitivity in LE. Other mechanisms must also be considered. The chromophore for photosensitivity induced by wavelengths longer than 320 nm has not been investigated in vivo. In vitro studies indicate that 360-400 nm radiation activates a photosensitizing compound in the lymphocytes and serum of LE patients and causes chromosomal aberrations and cell death. The mechanism appears to involve superoxide anion

  9. Radiative parameters for some transitions in Cu(II) and Ag(II) spectrum

    Biemont, E.; Blagoev, K.; Campos, J.; Mayo, R.; Malcheva, G.; Ortiz, M.; Quinet, P.

    2005-01-01

    Radiative parameters for transitions depopulating the levels belonging to the 3d 8 4s 2 configuration of Cu(II) and 4d 9 6s and 4d 9 5d configurations of Ag(II) have been obtained both theoretically and experimentally. On the experimental side, a laser-produced plasma was used as a source of Cu(II) and Ag(II) spectra. The light emitted by the plasma was focused on the input slit of a grating monochromator coupled with a time-resolved optical multichannel analyzer system. Spectral response calibration of the experimental system was made using a deuterium lamp in the wavelength range extending from 200 to 400-bar nm, and a standard tungsten lamp in the range from 350 to 600-bar nm. The transition probabilities were obtained using measured branching fractions and available radiative lifetimes of the corresponding states. On the theoretical side, a relativistic Hartree-Fock (HFR) approach, including core-polarization effects, has been used for the calculations. A reasonable agreement theory-experiment has been observed

  10. Solar neutrino spectrum, sterile neutrinos and additional radiation in the Universe

    Holanda, Pedro Cunha de

    2011-01-01

    Full text: Recent results from the SNO, Super-Kamiokande and Borexino experiments do not show the expected upturn of the energy spectrum of events (the ratio R ≡ N obs /N SSM ) at low energies. At the same time, cosmological observations testify for possible existence of additional relativistic degrees of freedom in the early Universe: ΔN eff = 1 - 2. These facts strengthen the case of very light sterile neutrino, ν s , with Δm 0 1 2 ∼ (0.7 - 2) . 10 -5 e V 2 , which mixes weakly with the active neutrinos. The ν s mixing in the mass eigenstate ν 1 characterized by sin 2 2∝ ∼ 10 -3 can explain an absence of the upturn. The mixing of ν s in the eigenstate ν 3 with sin 2 β ∼ 0.1 leads to production of ν s via oscillations in the Universe and to additional contribution Δ N eff ∼ 0.7 -1 before the big bang nucleosynthesis and later. Such a mixing can be tested in forthcoming experiments with the atmospheric neutrinos as well as in future accelerator long baseline experiments. It has substantial impact on conversion of the supernova neutrinos. We perform a qualitative and quantitative analysis of solar neutrino data including a fourth neutrino with different mixings with the active neutrino sector.(author)

  11. Quantum effects induced by a gap in the spectrum of atom-bath coupling constants: ''Freezing'' of atomic decay and monochromatic collective radiation

    Mogilevtsev, D.S.; Kilin, S.Ya.

    1994-08-01

    A specific kind of inhibition of atomic decay (''freezing of decay) and intense monochromatic collective radiation are predicted for a single two-level atom and for a system of atoms interacting with the field bath having the gap in the spectrum of coupling constants. (author). 10 refs, 5 figs

  12. Transformation of the angular power spectrum of the Cosmic Microwave Background (CMB) radiation into reciprocal spaces and consequences of this approach

    Červinka, Ladislav

    2011-01-01

    Roč. 2, č. 11 (2011), s. 1331-1347 ISSN 2153-120X Institutional research plan: CEZ:AV0Z10100521 Keywords : CMB radiation * analysis of CMB spectrum * radial distribution function of objects * early universe cluster structure * density of ordinary matter Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  13. Radiatively-driven winds: model improvements, ionization balance and the infared spectrum

    Castor, J.I.

    1979-01-01

    Recent improvements to theoretical stellar wind models and the results of empirical modelling of the ionization balance and the infrared continuum are discussed. The model of a wind driven by radiation pressure in spectral lines is improved by accounting for overlap of the driving lines, dependence of ionization balance on density, and stellar rotation. These effects produce a softer velocity law than that given by Castor, Abbott and Klein (1975). The ionization balance in zeta Puppis is shown to agree with that estimated for an optically thick wind at a gas temperature of 60,000 K. The ionization model is not unique. The infrared continuum of zeta Pup measured by Barlow and Cohen is fitted to a cool model with a linear rise of velocity with radius; this fit is also not unique. It is concluded that one should try to find a model that fits several kinds of evidence simultaneously. (Auth.)

  14. Synchrotron radiation photoemission spectrum study on K3C60 film

    李宏年; 徐亚伯; 鲍世宁; 李海洋; 何丕模; 钱海杰; 刘风琴; 奎热西·易卜拉欣

    2000-01-01

    K3C60 single crystal film was prepared on the cleaved (111) surface of C60 single crystal. Synchrotron radiation angle-resolved photoemission spectra were measured at normal emission with sample temperature at - 150K. Up to four subpeaks of LUMO-derived band were observed. These sub-peaks exhibit distinct energy dispersions which resemble in general the theoretical ones calculated for K3C60 at low temperature with the so-called one-dimensional disordered structure. But there is large deviation of experimental sub-band intervals from the theoretical values. This result is meaningful for the studies of the physical properties of alkali-doped C60 solids, e.g. the mechanism for superconductivity.

  15. The Positronium Radiative Combination Spectrum: Calculation in the Limit of Thermal Positrons and Low Densities

    Wallyn, P.; Mahoney, W. A.; Durouchoux, Ph.; Chapuis, C.

    1996-01-01

    We calculate the intensities of the positronium de-excitation lines for two processes: (1) the radiative combination of free thermal electrons and positrons for transitions with principal quantum number n less than 20, and (2) charge exchange between free positrons and hydrogen and helium atoms, restricting our evaluation to the Lyman-alpha line. We consider a low-density medium modeled by the case A assumption of Baker & Menzel and use the "nL method" of Pengelly to calculate the absolute intensities. We also evaluate the positronium fine and hyperfine intensities and show that these transitions are in all cases much weaker than positronium de-excitation lines in the same wavelength range. We also extrapolate our positronium de-excitation intensities to the submillimeter, millimeter, and centimeter wavelengths. Our results favor the search of infrared transitions of positronium lines for point sources when the visual extinction A, is greater than approx. 5.

  16. Theory of propagation of spectrum and correlations of radiation in optically dense gas in the case of the closed excitation contour

    Barantsev, K.A.; Litvinov, A.N.; Popov, E.N.

    2017-01-01

    This work is devoted to generalization of the semi-classical theory of interaction of broadband laser radiation with the atomic gas at the room temperature in the cell in the case of the closed excitation contour. The atomic density matrix equations and spectrum and correlations transport equations have been derived for excitation by fluctuating field with Gaussian statistics. It is shown that the spatial oscillations of radiation intensity and atomic density matrix can be excited. It was found that such medium can serve as a filter of incoherent part of the radiation.

  17. Geant4 simulation of ion chambers response to {sup 60}Co spectrum of LNMRI/IRD Shepherd 81-14D Radiator

    Queiroz Filho, P.P.; Silva, C.N.M. da, E-mail: queiroz@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The National Ionizing Radiation Metrology Laboratory of the Radioprotection and Dosimetry Institute (LNMRI / IRD) has recently acquired a Shepherd 81-14D Radiator. In this work we simulate, using Geant4, the behavior with the inverse square law radiation of the distance for 3 models of PTW spherical chambers used in radioprotection, a relevant information to planning the measurements. We did the corrections for the attenuation and scattering in the air for each distance, where we used the {sup 60}Co spectrum simulated previously. (author)

  18. Radiation

    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

  19. Oxygen-independent inactivation of Haemophilus influenzae transforming DNA by monochromatic radiation: action spectrum, effect of histidine and repair

    Cabrera-Juarez, E; Setlow, J K; Swenson, P A; Peak, M J

    1976-01-01

    The action spectrum for the oxygen-independent inactivation of native transforming DNA from Haemophilus influenzae with near-uv radiation revealed a shoulder beginning at 334 and extending to 460 nm. The presence of 0.2 M histidine during irradiation produced a small increase in inactivation at 254, 290 and 313 nm, a large increase at 334 nm and a decrease in inactivation at 365, 405, and 460 nm. Photoreactivation did not reverse the DNA damage produced at pH 7.0 at 334, 365, 405 and 460 nm, but did reactivate the DNA after irradiation at 254, 290 and 313 nm. The inactivation of DNA irradiated at 254, 290 and 313 nm was considerably greater when the transforming ability was assayed in an excision-defective mutant compared with the wild type, although DNA irradiated at 334, 365, 405 and 460 nm showed smaller differences. These results suggest that the oxygen-independent inactivation of H. influenzae DNA at pH 7 by irradiation at 334, 365, 405 and 460 nm is caused by lesions other than pyrimidine dimers.

  20. Analysis of the phase control of the ITER ICRH antenna array. Influence on the load resilience and radiated power spectrum

    Messiaen, A., E-mail: a.messiaen@fz-juelich.de; Ongena, J.; Vervier, M. [Laboratory for Plasma Physics, ERM-KMS, TEC partner, Cycle, B1000-Brussels (Belgium); Swain, D. [US ITER Team, ORNL (United States)

    2015-12-10

    The paper analyses how the phasing of the ITER ICRH 24 strap array evolves from the power sources up to the strap currents of the antenna. The study of the phasing control and coherence through the feeding circuits with prematching and automatic matching and decoupling network is made by modeling starting from the TOPICA matrix of the antenna array for a low coupling plasma profile and for current drive phasing (worst case for mutual coupling effects). The main results of the analysis are: (i) the strap current amplitude is well controlled by the antinode V{sub max} amplitude of the feeding lines, (ii) the best toroidal phasing control is done by the adjustment of the mean phase of V{sub max} of each poloidal straps column, (iii) with well adjusted system the largest strap current phasing error is ±20°, (iv) the effect on load resilience remains well below the maximum affordable VSWR of the generators, (v) the effect on the radiated power spectrum versus k{sub //} computed by means of the coupling code ANTITER II remains small for the considered cases.

  1. Effect of electron transport properties on unipolar CdZnTe radiation detectors: LUND, SpectrumPlus, and Coplanar Grid

    James, Ralph B.

    2000-01-01

    Device simulations of (1) the laterally-contacted-unipolar-nuclear detector (LUND), (2) the SpectrumPlus, (3) and the coplanar grid made of Cd 0.9 Zn 0.1 Te (CZT) were performed for 137 Cs irradiation by 662.15 keV gamma-rays. Realistic and controlled simulations of the gamma-ray interactions with the CZT material were done using the MCNP4B2 Monte Carlo program, and the detector responses were simulated using the Sandia three-dimensional multielectrode simulation program (SandTMSP). The simulations were done for the best and the worst expected carrier nobilities and lifetimes of currently commercially available CZT materials for radiation detector applications. For the simulated unipolar devices, the active device volumes were relatively large and the energy resolutions were fairly good, but these performance characteristics were found to be very sensitive to the materials properties. The internal electric fields, the weighting potentials, and the charge induced efficiency maps were calculated to give insights into the operation of these devices

  2. Use of an improved radiation amplification factor to estimate the effect of total ozone changes on action spectrum weighted irradiances and an instrument response function

    Herman, Jay R.

    2010-12-01

    Multiple scattering radiative transfer results are used to calculate action spectrum weighted irradiances and fractional irradiance changes in terms of a power law in ozone Ω, U(Ω/200)-RAF, where the new radiation amplification factor (RAF) is just a function of solar zenith angle. Including Rayleigh scattering caused small differences in the estimated 30 year changes in action spectrum-weighted irradiances compared to estimates that neglect multiple scattering. The radiative transfer results are applied to several action spectra and to an instrument response function corresponding to the Solar Light 501 meter. The effect of changing ozone on two plant damage action spectra are shown for plants with high sensitivity to UVB (280-315 nm) and those with lower sensitivity, showing that the probability for plant damage for the latter has increased since 1979, especially at middle to high latitudes in the Southern Hemisphere. Similarly, there has been an increase in rates of erythemal skin damage and pre-vitamin D3 production corresponding to measured ozone decreases. An example conversion function is derived to obtain erythemal irradiances and the UV index from measurements with the Solar Light 501 instrument response function. An analytic expressions is given to convert changes in erythemal irradiances to changes in CIE vitamin-D action spectrum weighted irradiances.

  3. Propagation of Polarized Cosmic Microwave Background Radiation in an Anisotropic Magnetized Plasma

    Moskaliuk, S. S.

    2010-01-01

    The polarization plane of the cosmic microwave background radiation (CMBR) can be rotated either in a space-time with metric of anisotropic type and in a magnetized plasma or in the presence of a quintessential background with pseudoscalar coupling to electromagnetism. A unified treatment of these three phenomena is presented for cold anisotropic plasma at the pre-recombination epoch. It is argued that the generalized expressions derived in the present study may be relevant for direct searches of a possible rotation of the cosmic microwave background polarization.

  4. A broad-spectrum sunscreen prevents cumulative damage from repeated exposure to sub-erythemal solar ultraviolet radiation representative of temperate latitudes.

    Seité, S; Christiaens, F; Bredoux, C; Compan, D; Zucchi, H; Lombard, D; Fourtanier, A; Young, A R

    2010-02-01

    We have previously shown the detrimental effects of 19 sub-erythemal exposures to daily ultraviolet radiation (DUVR, which mimics non-extreme exposure conditions), delivered over 4 weeks to volunteers. This source had UVA (320-400 nm) to UVB (290-320 nm) irradiance ratio of 25, instead of that close to 10 that is typically the case with solar-simulated radiation (SSR) that represents summer global sunlight with a clear sky and quasi-zenith solar irradiance. Here, we report on an extension of this previous study, in which we evaluated the photoprotection afforded by a broad-spectrum daily-care product with a low-sun protection factor (SPF 8, UVA-PF 7 and 3* rated UVA protection). We assessed cellular and molecular markers of photodamage that are relevant to skin cancer and photoageing. This study shows that biological effects of repeated exposure to DUVR can be prevented by a broad-spectrum daily-care product and that the level of protection afforded varies with the studied endpoint. Efficient daily UVR protection, as provided by a broad-spectrum daily-care product, is necessary to prevent the 'silent' sub-erythemal cumulative effects of UVR from inadvertent sun exposure.

  5. 基于MUSIC功率谱估计的直升机空中信号分析%Analysis of helicopter radiated signal based on MUSIC spectrum estimation

    李玲; 杜鹏

    2017-01-01

    针对直升机飞行的辐射噪声特征谱线进行分析,提出一种基于MUSIC算法的直升机声信号处理方法.首先阐述MUSIC谱估计方法,然后针对实测不同机型直升机的飞行辐射噪声数据,分别进行MUSIC算法和传统方法的频谱分析,对得到的结果进行分析比较,数据处理结果表明MUSIC算法能够抑制噪声,明显改善信噪比,并能够更为细致地体现直升机声信号的谐波特性.%A method based on multiple signal classification(MUSIC)algorithm is proposed to process the helicopter ra-diated acoustic signal with random noise under the condition of the assumption that is the signal and noise are mutually uncorrelated. This paper introduces the MUSIC spectrum estimation method, and then uses the traditional method and MUSIC algorithm to process the signals radiated by different types of helicopters. The results show that MUSIC spec-trum estimation can suppress the noise, extrude the peak of spectrum to improve signal to noise ratio obviously and re-flect the harmonic characteristics of helicopter acoustic signal accurately.

  6. Radiation

    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

  7. Production of a narrow band of 0. 511-MeV radiation by use of the PHERMEX bremsstrahlung spectrum. [Cross sections

    Stroscio, M.A.

    1976-06-01

    The pair production cross section is numerically integrated over a typical PHERMEX bremsstrahlung spectrum to obtain the probability of pair production in a target of nuclear charge Z, and density rho. The pair production cross section used herein is only approximate in that it neglects screening, neglects the Coulomb field for the emerging pair (first Born approximation), and neglects pair production by atomic electrons. In spite of these approximations, an order-of-magnitude estimate of the amount of 0.511-MeV radiation produced by a typical pulse is still given.

  8. Influence of induced colour centres on the frequency - angular spectrum of a light bullet of mid-IR radiation in lithium fluoride

    Chekalin, S. V.; Kompanets, V. O.; Dormidonov, A. E.; Kandidov, V. P.

    2017-04-01

    The influence of the occurrence of a structure consisting of long-lived colour centres, formed in an LiF crystal upon filamentation of femtosecond mid-IR radiation, on the supercontinuum characteristics is investigated. With an increase in the number of incident pulses, the length and transverse size of the structure of colour centres induced in LiF increase, and the supercontinuum spectrum in the short-wavelength region is markedly transformed due to the occurrence of the waveguide propagation regime, absorption, and scattering of radiation from the newly formed structure of colour centres. Under these conditions, the intensity of the anti-Stokes wing decreases by two orders of magnitude after several tens of pulses. Spectral components arise in the visible range, the angular divergence of which increases with increasing wavelength.

  9. Microscopic integral cross section measurements in the Be(d,n) neutron spectrum for applications in neutron dosimetry, radiation damage and the production of long-lived radionuclides

    Smith, D.L.; Meadows, J.W.; Greenwood, L.R.

    1990-01-01

    Integral neutron-reaction cross sections have been measured, relative to the U-238 neutron fission cross-section standard, for 27 reactions which are of contemporary interest in various nuclear applications (e.g., fast-neutron dosimetry, neutron radiation damage and the production of long-lived activities which affect nuclear waste disposal). The neutron radiation field employed in this study was produced by bombarding a thick Be-metal target with 7-MeV deuterons from an accelerator. The experimental results are reported along with detailed information on the associated measurement uncertainties and their correlations. These data are also compared with corresponding calculated values, based on contemporary knowledge of the differential cross sections and of the Be(d,n) neutron spectrum. Some conclusions are reached on the utility of this procedure for neutron-reaction data testing

  10. Investigation of energy spectrum and nuclear interactions of primary cosmic radiation; Badanie widma energetycznego i oddzialywan jadrowych pierwotnego promieniowania kosmicznego

    Wilczynski, H. [Dept. of High Energy Physics, The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

    1996-12-31

    In the paper the JACEE experiment data analysis: energy spectra in the energy range 10{sup 12} - 10{sup 15} eV of different nuclides in cosmic radiation and some aspects of nuclear interactions at energy above 10{sup 12} eV/nucleon is presented. The data were compared with results of theory of cosmic radiation acceleration by striking waves arises from supernova stars explosions. In the interactions of cosmic radiation nuclei the short-lived particles production has been observed what agrees with long-distance component of cascades initiated by cosmic radiation interactions. In one case an interaction with asymmetric photons emission were observed 72 refs, 33 figs, 4 tabs

  11. Spectral Kernel Approach to Study Radiative Response of Climate Variables and Interannual Variability of Reflected Solar Spectrum

    Jin, Zhonghai; Wielicki, Bruce A.; Loukachine, Constantin; Charlock, Thomas P.; Young, David; Noeel, Stefan

    2011-01-01

    The radiative kernel approach provides a simple way to separate the radiative response to different climate parameters and to decompose the feedback into radiative and climate response components. Using CERES/MODIS/Geostationary data, we calculated and analyzed the solar spectral reflectance kernels for various climate parameters on zonal, regional, and global spatial scales. The kernel linearity is tested. Errors in the kernel due to nonlinearity can vary strongly depending on climate parameter, wavelength, surface, and solar elevation; they are large in some absorption bands for some parameters but are negligible in most conditions. The spectral kernels are used to calculate the radiative responses to different climate parameter changes in different latitudes. The results show that the radiative response in high latitudes is sensitive to the coverage of snow and sea ice. The radiative response in low latitudes is contributed mainly by cloud property changes, especially cloud fraction and optical depth. The large cloud height effect is confined to absorption bands, while the cloud particle size effect is found mainly in the near infrared. The kernel approach, which is based on calculations using CERES retrievals, is then tested by direct comparison with spectral measurements from Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) (a different instrument on a different spacecraft). The monthly mean interannual variability of spectral reflectance based on the kernel technique is consistent with satellite observations over the ocean, but not over land, where both model and data have large uncertainty. RMS errors in kernel ]derived monthly global mean reflectance over the ocean compared to observations are about 0.001, and the sampling error is likely a major component.

  12. Parameter restoration of a soft X radiation spectrum by the signals of X-ray vacuum diodes

    Branitskij, A.V.; Olejnik, G.M.

    2000-01-01

    The multichannel measurement complex on the basis of vacuum X-ray diodes with various filters and the methodology of signals treatment, making it possible to obtained with nanosecond time resolution the radiation capacity in several spectral intervals, ranging from 0.1 up to 4 keV, the radiation capacity within the whole spectral range and the quantum average energy, are described. The method of linear combinations and the two-parametric models, providing close capacity values, are the most acceptable algorithms. This methodology was used at the Angara-5-1 facility in experiments on the cascade liners implosion and with the Z-pinch [ru

  13. Significance of 8-oxoG in the spectrum of DNA damages caused by ionising radiation of different quality

    Štěpán, Václav; Davídková, Marie

    2007-01-01

    Roč. 122, 1-4 (2007), s. 113-115 ISSN 0144-8420. [Symposium on Microdosimetry /14./. Venezia, 13.11.2005-18.11.2005] R&D Projects: GA AV ČR KJB4048401; GA ČR GA202/05/2728 Institutional research plan: CEZ:AV0Z10480505 Keywords : DNA damage * 8-oxoguanine * ionizing radiation * theoretical modeling Subject RIV: BO - Biophysics Impact factor: 0.528, year: 2007

  14. Mutational spectrum analysis of umuC-independent and umuC-dependent γ-radiation mutagenesis in Escherichia coli

    Sargentini, N.J.; Smith, K.C.

    1989-01-01

    γ-radiation mutagenesis Escherichia coli K-12. Mutagenesis (argE3(OC) A rg + ) was blocked in a δ(recA-srlR)306 strain at the same doses that induced mutations in umuC122::Tn5 and wild-type strains, indicating that both umuC-independent and umuC-dependent mechanisms function within recA-dependent misrepair. Analyses of various suppressor and back mutations that result in argE3 and hisG4 ochre reversion and an analysis of trpE9777 reversion were performed on umuC and wild-type cells irradiated in the presence and absence of oxygen. While the umuC strain showed the γ-radiation induction of base substitution and frameshifts when irradiated in the absence of oxygen, the umuC mutation blocked all oxygen-dependent base-substitution mutagenesis, but non all oxygen-dependent frameshift mutagenesis. For anoxically irradiated cells, the yields of GC T and AT GC transitions were essentially umuC independent, while the yields of (AT or GC) TA transversions were heavily umuC dependent. These data suggest new concepts about the nature of the DNA lesions and the mutagenic mechanisms that lead to γ-radiation mutagenesis. (author). 48 refs.; 1 tab.; 6 refs

  15. Monte Carlo study of MOSFET dosimeter dose correction factors considering energy spectrum of radiation field in a steam generator channel head

    Cho, Sung Koo; Choi, Sang Hyoun; Kim, Chan Hyeong [Hanyang Univ., Seoul (Korea, Republic of)

    2006-12-15

    In Korea, a real-time effective dose measurement system is in development. The system uses 32 high-sensitivity MOSFET dosimeters to measure radiation doses at various organ locations in an anthropomorphic physical phantom. The MOSFET dosimeters are, however, mainly made of silicon and shows some degree of energy and angular dependence especially for low energy photons. This study determines the correction factors to correct for these dependences of the MOSFET dosimeters for accurate measurement of radiation doses at organ locations in the phantom. For this, first, the dose correction factors of MOSFET dosimeters were determined for the energy spectrum in the steam generator channel of the Kori Nuclear Power Plant Unit no.1 by Monte Carlo simulations. Then, the results were compared with the dose correction factors from 0.662 MeV and 1.25 MeV mono-energetic photons. The difference of the dose correction factors were found very negligible ({<=}1.5%), which in general shows that the dose corrections factors determined from 0.662 MeV and 1.25 MeV can be in a steam general channel head of a nuclear power plant. The measured effective dose was generally found to decrease by {approx}7% when we apply the dose correction factors.

  16. Coherent Synchrotron Radiation for Rotational Spectroscopy: Application to the Rotational Spectrum of Propynal in the 200-750 GHz Range

    Barros, J.; Roy, P.; Appadoo, D.; Naughton, D. Mc; Robertson, E.; Manceron, L.

    2013-06-01

    In storage rings, short electron bunches can produce an intense THz radiation called Coherent Synchrotron Radiation (CSR). The flux of this emission between 250 and 750 GHz (in the mW range, up the 10000 times the regular synchrotron emission) is very advantageous for broad band absorption spectroscopy, using interferometric techniques. This source is, however, inherently difficult to stabilize, and intensity fluctuations lead to artifacts on the FT-based measurements, which strongly limit the use of CSR in particular for high-resolution measurements. At SOLEIL however, by screening different currents and bunch lengths, we defined stable CSR conditions for which the signal-to-noise ratio (S/N) allows for measurements at high resolution. Moreover, we developed an artifact correction system, based on a simultaneous detection of the input and the output signals of the interferometer, which allows to further improve the S/N. For this purpose, the optics and electronics of two bolometers were matched. The stable CSR combined with this ingenious technique allowed us to record for the first time high-resolution FT spectra in the sub-THz range, with a S/N of 100 in a few hours. This enables many applications such as broadband rotational spectra in the THz range, studies of molecules with low frequency torsional modes, absolute intensities determinations, or studies of unstable species. Results obtained on Propynal illustrate these possibilities and enabled to improve significantly the ground state spectroscopic constants.

  17. Properties of the generation of radiation in the near infrared part of the spectrum with a sapphire crystal laser having radiation-induced color centers

    Voitovich, A.P.; Grinkevich, V.E.; Kononov, V.A.; Kromskii, G.I.

    1986-01-01

    This paper investigates the spectral stability of the color centers in sapphire and the energy of lasers in which the active elements were colored with various techniques. Color centers were produced by neutron irradiation. The absorption spectra of the color centers are shown. The transformation of the spectra shows that the mutual conversions of color centers takes place during the thermal annealing of the sapphire; most of the color centers formed have luminescence. Generation or radiation with a tunable frequency was obtained in the case of transverse or quasi-longitudinal excitation by a ruby laser. The results show that ways for increasing the stability of the energy generated by a sapphire laser with color centers can be found

  18. Method of and system for determining a spectrum of radiation characteristics with full counting-loss compensation

    Westphal, G.P.

    1984-01-01

    Real-time correction of counting losses in the operation of a pulse-height analyzer, connected to the output of a radiation detector, is accomplished by establishing a gating interval at a time when the analyzer is available after processing the last detector pulse, this interval beginning at an instant delayed beyond the trailing edge of that last pulse by at least a predetermined rise time and ending with the leading edge of the next detector pulse. Test pulses generated during this gating interval are counted and their number is used to determine a probability ratio whose reciprocal constitutes a weighting factor; the digitized amplitude of each detector pulse addresses a corresponding memory cell whose contents are thereupon increased by the current weighting factor

  19. Comparison of horizontal and vertical noise power spectrum in measurements by using various electronic portal imaging devices in radiation therapy

    Kim, Ki Won [Dept. of Radiology, Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Choi, Kwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Technology, Baekseok Culture University, Cheonan (Korea, Republic of); Jang, Seo Goo [Dept. of Medical Science, Soonchunhyang University, Asan (Korea, Republic of); Kwon, Kyung Tae [Dept. of Radiological Technology, Dongnam Health University, Suwon (Korea, Republic of); Son, Soon Yong [Dept. of Radiological Technology, Wonkwang Health Science University, Iksan (Korea, Republic of); Son, Jin Hyun; Min, Jung Whan [Dept. of Radiological Technology, Shingu University, Sungnam (Korea, Republic of)

    2016-06-15

    The quality assurance (QA) is very important for diagnostic field and radiation therapy field to evaluate the characteristic of devices. The purpose of this study was to compare different NPS methodologies results which are measuring NPS with regard to horizontal and vertical directions by using megavoltage X-ray energies. The NPS evaluation methods were applied to the International Electro-technical Commission standard (IEC 62220-1). The electronic portal imaging devices (EPID) devices such as Siemens BEAMVIEWPLUS, Elekta iViewGT and Varian ClinacR iX aS1000 were used. NPS data were expressed by corresponding each frequency about average of noise value corresponding the each frequency, and NPS were evaluated quantitatively by totaling up the noise values of average frequency which are on horizontal and vertical directions. In NPS results for Elekta iViewGT, NPS of horizontal and vertical by using 4 methods were indicated the difference of 3-5% between horizontal and vertical direction. In the results of Siemens BEAMVIEWPLUS and Varian ClinacR iX aS1000, the NPS of horizontal and vertical direction were indicated the difference of 15% when averaging the whole values. This study were evaluated the NPS of each devices by totaling up the noise values of average frequency which are on horizontal and vertical directions suggesting the quantitative evaluation method using the data.

  20. Gamma radiation-induced mutant of NSIC RC144 with broad-spectrum resistance to bacterial blight

    Alfonso, A.A.; Avellanoza, E.S.; Miranda, R.T.; Espejo, E.O.; Garcia, N.S.

    2014-01-01

    Mutant lines derived from gamma radiation-treated commercial variety NSIC RC144 were produced and screened for novel resistance to bacterial blight, one of the most serious diseases of rice. Preliminary screening of a bulk M2 population through induced method using race 3 of the pathogen Xanthomonas oryzae pv. oryzae (Xoo) resulted in the selection of 89 resistant plants. Subsequent repeated bacterial blight screenings and generation advance for five seasons resulted in the selection of two highly resistant M7 sister lines whose origin can be traced to a single M2 plant. DNA fingerprinting using 63 genome-wide simple sequence repeat (SSR) markers revealed an identical pattern in these lines. Using the same set of markers, they also exhibited 98% similarity to wild type NSIC RC144 indicating that the resistance is due to mutation and not due to genetic admixture or seed impurity. Two seasons of bacterial blight screening using 14 local isolates representing ten races of Xoo revealed an identical reaction pattern in these lines. The reaction pattern was observed to be unique compared to known patterns in four IRBB isolines (IRBB 4, 5, 7 and 21) with strong resistant reaction to bacterial blight suggesting possible novel resistance. The susceptible reaction in F1 testcrosses using Xoo race 6 and the segregation patterns in two F2 populations that fit with the expected 3 susceptible: 1 resistant ratio (P = 0.4, ns) suggest a single-gene recessive mutation in these lines. These mutants are now being used as resistance donor in the breeding program while further molecular characterization to map and characterize the mutated gene is being pursued

  1. Mutagenesis in Caenorhabditis elegans. II. A spectrum of mutational events induced with 1500 r of gamma-radiation

    Rosenbluth, R.E.; Cuddeford, C.; Baillie, D.L.

    1985-01-01

    The authors previously established a gamma-ray dose-response curve for recessive lethal events (lethals) captured over the eT1 balancer. In this paper they analyze the nature of lethal events produced, with a frequency of 0.04 per eT1 region, at a dose of 1500 r. To do so, they developed a protocol that, in the absence of cytogenetics, allows balanced lethals to be analyzed for associated chromosomal rearrangements. A set of 35 lethal strains was chosen for the analysis. Although the dosage was relatively low, a large number of multiple-break events were observed. The fraction of lethals associated with rearrangements was found to be 0.76. Currently most X- and gamma-ray dosages used for mutagenesis in C. elegans are 6000-8000 r. From the data it was conservatively estimated that 43% of rearrangements induced with 8000 r would be accompanied by additional chromosome breaks in the genome. With 1500 r the value was 5%. The 35 lethals studied were derived from 875 screened F1's. Among these lethals there were (1) at least two unc-36 duplications, (2) at least four translocations, (3) at least six deficiencies of chromosome V (these delete about 90% of the unc-60 to unc-42 region) and (4) several unanalyzed rearrangements. Thus, it is possible to recover desired rearrangements at reasonable rates with a dose of only 1500 r. The authors suggest that the levels of ionizing radiation employed in most published C. elegans studies are excessive and efforts should be made to use reduced levels in the future

  2. Radiations

    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

  3. Radiation

    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.)

  4. Radiation carcinogenesis

    1978-01-01

    The Cancergram deals with all aspects of radiation carcinogenesis. The term radiation here includes U-V radiation and the entire electromagnetic spectrum, electron and other charged particle beams, neutrons, and alpha and beta radiation from radioactive substances. Abstracts included concern relationships between radiation and carcinogenesis in humans, experimental induction of tumors in animals by irradiation, studies on the mechanism of radiation carcinogenesis at the cellular level, studies of RBE, dose response or dose threshold in relation to radiation carcinogenesis, and methods and policies for control of radiation exposure in the general population. In general, this Cancergram excludes abstracts on radio-therapy, radiologic diagnosis, radiation pathology, and radiation biology, where these articles have no bearing on radiation carcinogenesis

  5. Spectrum Recombination.

    Greenslade, Thomas B., Jr.

    1984-01-01

    Describes several methods of executing lecture demonstrations involving the recombination of the spectrum. Groups the techniques into two general classes: bringing selected portions of the spectrum together using lenses or mirrors and blurring the colors by rapid movement or foreshortening. (JM)

  6. Cosmic archeology with the Cosmic Microwave Background Radiation

    Carlos Alexandre Wuensche de Souza

    2010-03-01

    how the Universe "started" and evolved to what we see today. We will discuss in this article some challenges faced by modern cosmology to be able to describe our Universe and how CMBR observations can help in this task.

  7. OBJECT KINETIC MONTE CARLO SIMULATIONS OF RADIATION DAMAGE IN TUNGSTEN SUBJECTED TO NEUTRON FLUX WITH PKA SPECTRUM CORRESPONDING TO THE HFIR

    Nandipati, Giridhar; Setyawan, Wahyu; Heinisch, Howard L.; Roche, Kenneth J.; Kurtz, Richard J.; Wirth, Brian D.

    2015-12-31

    The objective of this work is to study the damage accumulation in pure tungsten (W) subjected to neutron bombardment with a primary knock-on atom (PKA) spectrum corresponding to the High Flux Isotope Reactor (HFIR), using the object kinetic Monte Carlo (OKMC) method.

  8. The technique on handling radiation

    1997-11-01

    This book describes measurement of radiation and handling radiation. The first part deals with measurement of radiation. The contents of this part are characteristic on measurement technique of radiation, radiation detector, measurement of energy spectrum, measurement of radioactivity, measurement for a level of radiation and county's statistics on radiation. The second parts explains handling radiation with treating of sealed radioisotope, treating unsealed source and radiation shield.

  9. Zellweger Spectrum

    ... severe defect, resulting in essentially nonfunctional peroxisomes. This phenomenon produces the range of severity of the disorders. How is the Zellweger Spectrum Diagnosed? The distinctive shape of the head and face of a child born with one of the diseases of the ...

  10. Comprehension of radiation for RI license

    Guk, Jin Sun

    2005-08-01

    This book starts with theoretical nuclear energy which explains technical terms such as nuclear physics and chemistry, RI and utilization of radiation, radiochemistry and radiation chemistry, radiation biology. It also explains radiation measurements technology including radiation detector and measurements radiation measurements circuit, measuring of energy spectrum. Radiation protection monitoring for radiation protection. It deals with nuclear law, enforcement regulation and ordinance.

  11. Synchrotron radiation

    Farge, Y.

    1982-01-01

    Synchrotron radiation is produced by electrons accelerated near the velocity of light in storage rings, which are used for high energy Physics experiments. The radiation light exhibits a wide spread continuous spectrum ranging from 01 nanometre to radiofrequency. This radiation is characterized by high power (several kilowatts) and intense brightness. The paper recalls the emission laws and the distinctive properties of the radiation, and gives some of the numerous applications in research, such as molecular spectroscopy, X ray diffraction by heavy proteins and X ray microlithography in LVSI circuit making [fr

  12. Spectrum of cosmic fireballs

    Cavallo, G [Consiglio Nazionale delle Ricerche, Bologna (Italy). Lab. TESRE; Horstman, H M [Bologna Univ. (Italy). Ist. di Astronomia

    1981-03-01

    A progress report on cosmic fireballs is presented. The main new results are: (a) the phenomenon should be almost universal, and most explosive ..gamma..-ray sources should show the characteristic fireball spectrum; (b) even if the radiation density is insufficient, pair production in electron-proton or electron-electron scattering might start the fireball; (c) some computed fireball spectra are shown. They all have in common a 1/E low-energy behaviour, a 100 keV flattening, and a approx.0.5 MeV cut-off.

  13. Measurement of Gamma-ray Energy Spectrum According to Temperature Variation Using a Fiber-Optic Radiation Sensor Based on YSO:Ce Crystal

    Jeon, H.; Yoo, W. J.; Shin, S. H.; Jang, J. S.; Kim, J. S.; Kwon, G.; Lee, D. E.; Jang, K. W.; Lee, B. [BK21 Plus Research Institute of Biomedical Engineering, Konkuk University, Chungju (Korea, Republic of)

    2015-05-15

    As an alternative to conventional radiation detectors, various fiber-optic radiation sensors (FORSs) have been investigated for gamma-ray monitoring because of their various desirable advantages, such as their small sensing volume, substantial flexibility, remote operation, ability to make real-time measurement, and immunity to high electromagnetic interference. In general, the basic principle of a radiation detection using scintillators is to measure the scintillating light signals generated from the interactions between the scintillators and the radiations. To measure gamma-ray, the inorganic scintillators used in the FORS should have some properties, such as high atomic material, high light yields, fast decay time, high density, and high stopping power. For these reasons, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) crystal has been introduced as a promising scintillator in various radiation sensor applications. According to the recent studies, however, LYSO:Ce crystal is impossible to be applied in high-temperature conditions because it serves the fluctuations of its light yields with the temperature variation (i.e., thermosluminescence). In this study, to obtain gamma-ray energy spectra by measuring scintillating light signals emitted from the scintillators in high-temperature conditions, we first fabricated an FORS system using various inorganic scintillator crystals and then evaluated the light yields of each inorganic scintillator. As a promising scintillator for use in high-temperature conditions, a cerium-doped yttrium orthosilicate (YSO:Ce) crystal was selected and evaluated its thermal property according to the elevated temperature up to 300 .deg. C. We fabricated an FORS using inorganic scintillator and an optical fiber bundle. To select an adequate scintillator to apply in high-temperature conditions, the gamma-ray energy spectra were obtained by using four kinds of inorganic scintillators. From the experimental results, we selected YSO

  14. Broadening the spectrum through curriculum

    Engel-Hills P

    2006-01-01

    Radiography has experienced changes and challenges from a number of sources. The rapid technological changes in imaging an radiation treatment, changes in the professional context and social transformation have had an impact on the shape and structure of the radiography curriculum. It too must change to prepare graduates for the broadening radiography spectrum

  15. The sun protection factor (SPF) inadequately defines broad spectrum photoprotection: demonstration using skin reconstructed in vitro exposed to UVA, UVBor UV-solar simulated radiation.

    Bernerd, Françoise; Vioux, Corinne; Lejeune, François; Asselineau, Daniel

    2003-01-01

    Wavelength specific biological damage has been previously identified in human skin reconstructed in vitro. Sunburn cell and pyrimidine dimers were found after UVB exposure, and alterations of dermal fibroblasts after UVA exposure. These damages permitted us to discriminate UVB and UVA single absorbers. The present study shows that these biological effects can be obtained simultaneously by a combined UVB + UVA exposure using ultraviolet solar simulated light (UV-SSR), which represents a relevant UV source. In addition, the protection afforded by two broad spectrum sunscreen complex formulations was assessed after topical application. These two formulations displayed the same sun protection factor but different UVA protection factors determined by the persistent pigment darkening (PPD) method. Dose response experiments of UVA or UV-SSR showed that the preparation with the highest PF-UVA provided a better protection with regard to dermal damage compared to the other formulation. Using an original UVB source to obtain the UVB portion of SSR spectrum, the preparations provided the same protection. This study strikingly illustrates the fact that the photoprotection afforded by two sunscreen formulations having similar SPF values is not equal with regard to dermal damage related to photoaging.

  16. Spectrum management for science in the 21st century

    Committee on Scientific Use of the Radio Spectrum; Committee on Radio Frequencies; National Research Council; Division on Engineering and Physical Sciences; National Research Council

    2010-01-01

    .... The radio spectrum is also being used by radiating, or 'active,' services, ranging from aircraft radars to rapidly expanding consumer services such as cellular telephones and wireless internet...

  17. Natural gamma ray spectrum analysis technique

    Chevalier, P.; Seeman, B.

    1976-01-01

    In accordance with an illustrative embodiment of the present invention, a method and apparatus is disclosed for determining the presence of a selected number of naturally radioactive materials in an earth formation from the spectrum of natural gamma radiation emitted by the materials in the formation by deriving representations of portions of the detected gamma radiation spectrum and combining the representations to determine therefrom the presence of the selected materials

  18. The human dorsal spinocerebellar tract: myelinated fiber spectrum and fiber density in controls, autosomal dominant spinocerebellar atrophy, Huntington's chorea, radiation myelopathy, and diseases with peripheral sensory nerve involvement

    Ringelstein, E.B.; Schroeder, J.M.

    1982-01-01

    The human dorsal spinocerebellar tract (DSCT) was evaluated morphometrically in 14 control cases of different age and sex using semithin sections of epon-embedded cross sections from the C3, T5, and T10 segments of the spinal cord. A bimodal fiber spectrum was revealed with one peak at 2-3 microns, and a second, broader peak at about 6-8 microns. Fiber density at C3 was 11,188 fibers/mm2 and at T5, 11,156 fibers/mm2. Regression analysis relating fiber density to age disclosed a highly significant loss of myelinated fibers at T5 amounting to about 2.5% per decade. A severe reduction of fiber density and a distinct change in the fiber spectrum with predominant loss of large myelinated fibers were noted in a case of autosomal dominant spinocerebellar atrophy with late onset, and, to a lesser degree, in a case of Huntington's chorea. A subtotal loss of fibers with a persistent normal distribution of fiber sizes was observed rostral to a focus of severe radiation myelopathy, indicating Wallerian degeneration of large numbers of fibers, and a reduction of fiber diameters caudal to the lesion, suggesting retrograde fiber change. By contrast, no primary or transneural changes in the DSCT were detected in six cases of long-term alcoholism, carcinomatous sensory neuropathy, and neurofibromatosis in spite of the involvement of numerous nerve roots.

  19. Spectrum 101: An Introduction to Spectrum Management

    2004-03-01

    produces a Joint Restricted Frequency List (JRFL). The JFRL consolidates and classifies the spectrum uses that are most critical to operations and to...Management Office JRFL Joint Restricted Frequency List JSC Joint Spectrum Center JSIR Joint Spectrum Interference Resolution JSME Joint Spectrum...Multifunctional Information Distribution System MILSATCOM Military Satellite Communications MOA Memorandum of Agreement MRFL Master Radio Frequency

  20. Synchrotron radiation

    Kunz, C

    1974-01-01

    The production of synchrotron radiation as a by-product of circular high-energy electron (positron) accelerators or storage rings is briefly discussed. A listing of existing or planned synchrotron radiation laboratories is included. The following properties are discussed: spectrum, collimation, polarization, and intensity; a short comparison with other sources (lasers and X-ray tubes) is also given. The remainder of the paper describes the experimental installations at the Deutsches Elektronen-Synchrotron (DESY) and DORIS storage rings, presents a few typical examples out of the fields of atomic, molecular, and solid-state spectroscopy, and finishes with an outlook on the use of synchrotron radiation in molecular biology. (21 refs).

  1. Energy spectrum of lightning gamma emission

    Chubenko, A.P. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Karashtin, A.N. [Research Radiophysics Institute, Nizhny Novgorod (Russian Federation); Ryabov, V.A., E-mail: ryabov@x4u.lebedev.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shepetov, A.L. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Antonova, V.P.; Kryukov, S.V. [Ionosphere Institute, Almaty (Kazakhstan); Mitko, G.G.; Naumov, A.S.; Pavljuchenko, L.V. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Ptitsyn, M.O., E-mail: ptitsyn@lpi.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shalamova, S.Ya. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shlyugaev, Yu.V. [Research Radiophysics Institute, Nizhny Novgorod (Russian Federation); Vildanova, L.I. [Tien-Shan Mountain Cosmic Ray Station, Almaty (Kazakhstan); Zybin, K.P. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Gurevich, A.V., E-mail: alex@lpi.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation)

    2009-08-10

    The results of gamma emission observations obtained during thunderstorms at Tien-Shan Mountain Cosmic Ray Station are presented. The energy spectrum radiation of the stepped leader gamma radiation is measured. The total energy of stepped leader emitted in gamma rays is estimated as 10{sup -3}-10{sup -2} J. The experimental results are in an agreement with the runaway breakdown mechanism.

  2. Energy spectrum of lightning gamma emission

    Chubenko, A.P.; Karashtin, A.N.; Ryabov, V.A.; Shepetov, A.L.; Antonova, V.P.; Kryukov, S.V.; Mitko, G.G.; Naumov, A.S.; Pavljuchenko, L.V.; Ptitsyn, M.O.; Shalamova, S.Ya.; Shlyugaev, Yu.V.; Vildanova, L.I.; Zybin, K.P.; Gurevich, A.V.

    2009-01-01

    The results of gamma emission observations obtained during thunderstorms at Tien-Shan Mountain Cosmic Ray Station are presented. The energy spectrum radiation of the stepped leader gamma radiation is measured. The total energy of stepped leader emitted in gamma rays is estimated as 10 -3 -10 -2 J. The experimental results are in an agreement with the runaway breakdown mechanism.

  3. Industrial application of radiation curing

    Sasaki, Takashi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1994-12-31

    The contents are advantages of radiation processes - a solvent-free system, less energy consumative, higher production rate, processability at ambient temperature; electron beams vs. ultraviolet curing; applications -broad spectrum of markets use radiation curable materials.

  4. Industrial application of radiation curing

    Takashi Sasaki

    1993-01-01

    The contents are advantages of radiation processes - a solvent-free system, less energy consumative, higher production rate, processability at ambient temperature; electron beams vs. ultraviolet curing; applications -broad spectrum of markets use radiation curable materials

  5. Low dose out-of-field radiotherapy, part 2: Calculating the mean photon energy values for the out-of-field photon energy spectrum from scattered radiation using Monte Carlo methods.

    Skrobala, A; Adamczyk, S; Kruszyna-Mochalska, M; Skórska, M; Konefał, A; Suchorska, W; Zaleska, K; Kowalik, A; Jackowiak, W; Malicki, J

    2017-08-01

    During radiotherapy, leakage from the machine head and collimator expose patients to out-of-field irradiation doses, which may cause secondary cancers. To quantify the risks of secondary cancers due to out-of-field doses, it is first necessary to measure these doses. Since most dosimeters are energy-dependent, it is essential to first determine the type of photon energy spectrum in the out-of-field area. The aim of this study was to determine the mean photon energy values for the out-of-field photon energy spectrum for a 6 MV photon beam using the GEANT 4-Monte Carlo method. A specially-designed large water phantom was simulated with a static field at gantry 0°. The source-to-surface distance was 92cm for an open field size of 10×10cm2. The photon energy spectra were calculated at five unique positions (at depths of 0.5, 1.6, 4, 6, 8, and 10cm) along the central beam axis and at six different off-axis distances. Monte Carlo simulations showed that mean radiation energy levels drop rapidly beyond the edge of the 6 MV photon beam field: at a distance of 10cm, the mean energy level is close to 0.3MeV versus 1.5MeV at the central beam axis. In some cases, the energy level actually increased even as the distance from the field edge increased: at a depth of 1.6cm and 15cm off-axis, the mean energy level was 0.205MeV versus 0.252MeV at 20cm off-axis. The out-of-field energy spectra and dose distribution data obtained in this study with Monte Carlo methods can be used to calibrate dosimeters to measure out-of-field radiation from 6MV photons. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  6. Synchrotron-radiation research

    Cunningham, J.E.

    1982-01-01

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

  7. Radiation signatures

    McGlynn, S.P.; Varma, M.N.

    1992-01-01

    A new concept for modelling radiation risk is proposed. This concept is based on the proposal that the spectrum of molecular lesions, which we dub ''the radiation signature'', can be used to identify the quality of the causal radiation. If the proposal concerning radiation signatures can be established then, in principle, both prospective and retrospective risk determination can be assessed on an individual basis. A major goal of biophysical modelling is to relate physical events such as ionization, excitation, etc. to the production of radiation carcinogenesis. A description of the physical events is provided by track structure. The track structure is determined by radiation quality, and it can be considered to be the ''physical signature'' of the radiation. Unfortunately, the uniqueness characteristics of this signature are dissipated in biological systems in ∼10 -9 s. Nonetheless, it is our contention that this physical disturbance of the biological system eventuates later, at ∼10 0 s, in molecular lesion spectra which also characterize the causal radiation. (author)

  8. The Spectrum of the Universe.

    Hill, Ryley; Masui, Kiyoshi W; Scott, Douglas

    2018-05-01

    Cosmic background (CB) radiation, encompassing the sum of emission from all sources outside our own Milky Way galaxy across the entire electromagnetic spectrum, is a fundamental phenomenon in observational cosmology. Many experiments have been conceived to measure it (or its constituents) since the extragalactic Universe was first discovered; in addition to estimating the bulk (cosmic monopole) spectrum, directional variations have also been detected over a wide range of wavelengths. Here we gather the most recent of these measurements and discuss the current status of our understanding of the CB from radio to γ-ray energies. Using available data in the literature, we piece together the sky-averaged intensity spectrum and discuss the emission processes responsible for what is observed. We examine the effect of perturbations to the continuum spectrum from atomic and molecular line processes and comment on the detectability of these signals. We also discuss how one could, in principle, obtain a complete census of the CB by measuring the full spectrum of each spherical harmonic expansion coefficient. This set of spectra of multipole moments effectively encodes the entire statistical history of nuclear, atomic, and molecular processes in the Universe.

  9. Spectrum estimation method based on marginal spectrum

    Cai Jianhua; Hu Weiwen; Wang Xianchun

    2011-01-01

    FFT method can not meet the basic requirements of power spectrum for non-stationary signal and short signal. A new spectrum estimation method based on marginal spectrum from Hilbert-Huang transform (HHT) was proposed. The procession of obtaining marginal spectrum in HHT method was given and the linear property of marginal spectrum was demonstrated. Compared with the FFT method, the physical meaning and the frequency resolution of marginal spectrum were further analyzed. Then the Hilbert spectrum estimation algorithm was discussed in detail, and the simulation results were given at last. The theory and simulation shows that under the condition of short data signal and non-stationary signal, the frequency resolution and estimation precision of HHT method is better than that of FFT method. (authors)

  10. Radiation shelter

    Crookes, T.A.

    1982-01-01

    This patent application describes a shelter comprising a cavity for receiving life to be sheltered; a roof for covering at least a portion of said cavity, and at least one aqueous, protective barrier layer adapted to prevent transmission through said roof and into said cavity of at least a portion of radiation in a predetermined spectrum. The cavity walls may be impregnated with an oil suitable for dressing burns. (author)

  11. Photodetector of ultraviolet radiation

    Dorogan, V.; Branzari, V.; Vieru, T.; Manole, M.; Canter, V.

    2000-01-01

    The invention relates to photodetectors on base of semiconductors of ultraviolet radiation and may be used in optoelectronic system for determining the intensity and the dose of ultraviolet radiation emitted by the Sun or other sources. Summary of the invention consists in the fact that in the photodetector of ultraviolet radiation the superficial potential barrier is divided into two identical elements, electrically isolated each of the other, one of them being covered with a layer of transparent material for visible and infrared radiation and absorption the ultra violet radiation. The technical result consists in mutual compensation of visible and infrared components of the radiation spectrum

  12. Personnel ionizing radiation dosimeter

    Williams, R.A.

    1975-01-01

    A dosimeter and method for use by personnel working in an area of mixed ionizing radiation fields for measuring and/or determining the effective energy of x- and gamma radiation; beta, x-, and gamma radiation dose equivalent to the surface of the body; beta, x-, and gamma radiation dose equivalent at a depth in the body; the presence of slow neutron, fast neutron dose equivalent; and orientation of the person wearing the dosimeter to the source of radiation is disclosed. Optionally integrated into this device and method are improved means for determining neutron energy spectrum and absorbed dose from fission gamma and neutron radiation resulting from accidental criticality

  13. Sound spectrum of a pulsating optical discharge

    Grachev, G N; Smirnov, A L; Tishchenko, V N [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Dmitriev, A K; Miroshnichenko, I B [Novosibirsk State Technical University (Russian Federation)

    2016-02-28

    A spectrum of sound of an optical discharge generated by a repetitively pulsed (RP) laser radiation has been investigated. The parameters of laser radiation are determined at which the spectrum of sound may contains either many lines, or the main line at the pulse repetition rate and several weaker overtones, or a single line. The spectrum of sound produced by trains of RP radiation comprises the line (and overtones) at the repetition rate of train sequences and the line at the repetition rate of pulses in trains. A CO{sub 2} laser with the pulse repetition rate of f ≈ 3 – 180 kHz and the average power of up to 2 W was used in the experiments. (optical discharges)

  14. Diffusion effects in undulator radiation

    Ilya Agapov

    2014-11-01

    Full Text Available Quantum diffusion effects in undulator radiation in semiclassical approximation are considered. Short-term effects on the electron beam motion are discussed and it is shown that approaches based on diffusion approximation with drift-diffusion coefficients derived from undulator or bending magnet radiation spectrum, and on Poisson statistics with radiation spectrum defined by the local beding field, all lead to similar results in terms of electron energy spread for cases of practical interest. An analytical estimate of the influence of quantum diffusion on the undulator radiation spectrum is derived.

  15. Primordial power spectrum features and consequences

    Goswami, G.

    2014-03-01

    The present Cosmic Microwave Background (CMB) temperature and polarization anisotropy data is consistent with not only a power law scalar primordial power spectrum (PPS) with a small running but also with the scalar PPS having very sharp features. This has motivated inflationary models with such sharp features. Recently, even the possibility of having nulls in the power spectrum (at certain scales) has been considered. The existence of these nulls has been shown in linear perturbation theory. What shall be the effect of higher order corrections on such nulls? Inspired by this question, we have attempted to calculate quantum radiative corrections to the Fourier transform of the 2-point function in a toy field theory and address the issue of how these corrections to the power spectrum behave in models in which the tree-level power spectrum has a sharp dip (but not a null). In particular, we have considered the possibility of the relative enhancement of radiative corrections in a model in which the tree-level spectrum goes through a dip in power at a certain scale. The mode functions of the field (whose power spectrum is to be evaluated) are chosen such that they undergo the kind of dynamics that leads to a sharp dip in the tree level power spectrum. Next, we have considered the situation in which this field has quartic self interactions, and found one loop correction in a suitably chosen renormalization scheme. Thus, we have attempted to answer the following key question in the context of this toy model (which is as important in the realistic case): In the chosen renormalization scheme, can quantum radiative corrections be enhanced relative to tree-level power spectrum at scales, at which sharp dips appear in the tree-level spectrum?

  16. Adjustment of the 235U Fission Spectrum

    GRIFFIN, PATRICK J.; WILLIAMS, J.G.

    1999-01-01

    The latest nuclear data are used to examine the sensitivity of the least squares adjustment of the 235 U fission spectrum to the measured reaction rates, dosimetry cross sections, and prior spectrum covariance matrix. All of these parameters were found to be very important in the spectrum adjustment. The most significant deficiency in the nuclear data is the absence of a good prior covariance matrix. Covariance matrices generated from analytic models of the fission spectra have been used in the past. This analysis reveals some unusual features in the covariance matrix produced with this approach. Specific needs are identified for improved nuclear data to better determine the 235 U spectrum. An improved 235 U covariance matrix and adjusted spectrum are recommended for use in radiation transport sensitivity analyses

  17. The threshold photoelectron spectrum of mercury

    Rojas, H; Dawber, G; Gulley, N; King, G C; Bowring, N; Ward, R

    2013-01-01

    The threshold photoelectron spectrum of mercury has been recorded over the energy range (10–40 eV) which covers the region from the lowest state of the singly charged ion, 5d 10 6s( 2 S 1/2 ), to the double charged ionic state, 5d 9 ( 2 D 3/2 )6s( 1 D 2 ). Synchrotron radiation has been used in conjunction with the penetrating-field threshold-electron technique to obtain the spectrum with high resolution. The spectrum shows many more features than observed in previous photoemission measurements with many of these assigned to satellite states converging to the double ionization limit. (paper)

  18. Broad spectrum bioactive sunscreens.

    Velasco, Maria Valéria Robles; Sarruf, Fernanda Daud; Salgado-Santos, Idalina Maria Nunes; Haroutiounian-Filho, Carlos Alberto; Kaneko, Telma Mary; Baby, André Rolim

    2008-11-03

    The development of sunscreens containing reduced concentration of chemical UV filters, even though, possessing broad spectrum effectiveness with the use of natural raw materials that improve and infer UV absorption is of great interest. Due to the structural similarities between polyphenolic compounds and organic UV filters, they might exert photoprotection activity. The objective of the present research work was to develop bioactive sunscreen delivery systems containing rutin, Passiflora incarnata L. and Plantago lanceolata extracts associated or not with organic and inorganic UV filters. UV transmission of the sunscreen delivery system films was performed by using diffuse transmittance measurements coupling to an integrating sphere. In vitro photoprotection efficacy was evaluated according to the following parameters: estimated sun protection factor (SPF); Boot's Star Rating category; UVA/UVB ratio; and critical wavelength (lambda(c)). Sunscreen delivery systems obtained SPF values ranging from 0.972+/-0.004 to 28.064+/-2.429 and bioactive compounds interacted with the UV filters positive and negatively. This behavior may be attributed to: the composition of the delivery system; the presence of inorganic UV filter and quantitative composition of the organic UV filters; and the phytochemical composition of the P. incarnata L. and P. lanceolata extracts. Among all associations of bioactive compounds and UV filters, we found that the broad spectrum sunscreen was accomplished when 1.68% (w/w) P. incarnata L. dry extract was in the presence of 7.0% (w/w) ethylhexyl methoxycinnamate, 2.0% (w/w) benzophenone-3 and 2.0% (w/w) TiO(2). It was demonstrated that this association generated estimated SPF of 20.072+/-0.906 and it has improved the protective defense against UVA radiation accompanying augmentation of the UVA/UVB ratio from 0.49 to 0.52 and lambda(c) from 364 to 368.6nm.

  19. Radiative electron capture

    Biggerstaff, J.A.; Appleton, B.R.; Datz, S.; Moak, C.D.; Neelavathi, V.N.; Noggle, T.S.; Ritchie, R.H.; VerBeek, H.

    1975-01-01

    Some data are presented for radiative electron capture by fast moving ions. The radiative electron capture spectrum is shown for O 8+ in Ag, along with the energy dependence of the capture cross-section. A discrepancy between earlier data, theoretical prediction, and the present data is pointed out. (3 figs) (U.S.)

  20. Determination of QW laser diode degradation based on the emission spectrum

    Bliznyuk Vladimir

    2017-01-01

    Full Text Available The possibility of laser diodes degradation control by monitoring of their spectrum is shown. For red and infra-red laser diodes, the time dependence of the radiation spectrum width was obtained.

  1. Many channel spectrum unfolding

    Najzer, M.; Glumac, B.; Pauko, M.

    1980-01-01

    The principle of the ITER unfolding code as used for the many channel spectrum unfolding is described. Its unfolding ability is tested on seven typical neutron spectra. The effect of the initial spectrum approximation upon the solution is discussed

  2. Pulsar Emission Spectrum

    Gruzinov, Andrei

    2013-01-01

    Emission spectrum is calculated for a weak axisymmetric pulsar. Also calculated are the observed spectrum, efficiency, and the observed efficiency. The underlying flow of electrons and positrons turns out to be curiously intricate.

  3. Autism Spectrum Disorder

    ... Caregiver Education » Fact Sheets Autism Spectrum Disorder Fact Sheet What is autism spectrum disorder? What are some ... of mutations in individual genes but rather spontaneous coding mutations across many genes. De novo mutations may ...

  4. The structure of the world from pure numbers

    Tipler, F J

    2005-01-01

    I investigate the relationship between physics and mathematics. I argue that physics can shed light on the proper foundations of mathematics, and that the nature of number can constrain the nature of physical reality. I show that requiring the joint mathematical consistency of the Standard Model of particle physics and the DeWitt-Feynman-Weinberg theory of quantum gravity can resolve the horizon, flatness and isotropy problems of cosmology. Joint mathematical consistency naturally yields a scale-free, Gaussian, adiabatic perturbation spectrum, and more matter than antimatter. I show that consistency requires the universe to begin at an initial singularity with a pure SU(2) L gauge field. I show that quantum mechanics requires this field to have a Planckian spectrum whatever its temperature. If this field has managed to survive thermalization to the present day, then it would be the cosmic microwave background radiation (CMBR). If so, then we would have a natural explanation for the dark matter and the dark energy. I show that isotropic ultrahigh energy cosmic rays are explained if the CMBR is a pure SU(2) L gauge field. The SU(2) L nature of the CMBR may have been seen in the Sunyaev-Zel'dovich effect. I propose several simple experiments to test the hypothesis

  5. SYNTH: A spectrum synthesizer

    Hensley, W.K.; McKinnon, A.D.; Miley, H.S.; Panisko, M.E.; Savard, R.M.

    1994-07-01

    A computer code has been written at the Pacific Northwest Laboratory (PNL) to synthesize the results of typical gamma-ray spectroscopy experiments. The code, dubbed SYNTH, allows a use r to specify physical characteristics of a gamma-ray source, the quantity of the nuclides producing the radiation, the source-to-detector distance and the type and thickness of absorbers, the size and composition of the detector (Ge or NaI), and the electronic set up used to gather the data. In the process of specifying the parameters needed to synthesize a spectrum, several interesting intermediate results are produced, including a photopeak transmission function vs energy, a detector efficiency curve, and a weighted list of gamma and x rays produced from a set of nuclides. All of these intermediate results are available for graphical inspection and for printing. SYNTH runs on personal computers. It is menu driven and can be customized to user specifications. SYNTH contains robust support for coaxial germanium detectors and some support for sodium iodide detectors. SYNTH is not a finished product. A number of additional developments are planned. However, the existing code has been compared carefully to spectra obtained from National Institute for Standards and Technology (NIST) certified standards with very favorable results. Examples of the use of SYNTH and several spectral results will be presented

  6. SYNTH: A spectrum synthesizer

    Hensley, W.K.; McKinnon, A.D.; Miley, H.S.; Panisko, M.E.; Savard, R.M.

    1993-10-01

    A computer code has been written at the Pacific Northwest Laboratory (PNL) to synthesize the results of typical gamma ray spectroscopy experiments. The code, dubbed SYNTH, allows a user to specify physical characteristics of a gamma ray source, the quantity of the nuclides producing the radiation, the source-to-detector distance and the presence of absorbers, the type and size of the detector, and the electronic set up used to gather the data. In the process of specifying the parameters needed to synthesize a spectrum, several interesting intermediate results are produced, including a photopeak transmission function versus energy, a detector efficiency curve, and a weighted list of gamma and x rays produced from a set of nuclides. All of these intermediate results are available for graphical inspection and for printing. SYNTH runs on personal computers. It is menu driven and can be customized to user specifications. SYNTH contains robust support for coaxial germanium detectors and some support for sodium iodide detectors. SYNTH is not a finished product. A number of additional developments are planned. However, the existing code has been compared carefully to spectra obtained from National Institute for Standards and Technology (NIST) certified standards with very favorable results. Examples of the use of SYNTH and several spectral results are presented

  7. Mars' radio spectrum and the flying dust.

    Roos-Serote, M.; Stam, D.M.; Fender, R.P.

    2004-01-01

    Mars' radio spectrum at centimeter wavelengths is produced by thermal radiation from the surface and sub-surface. Observations at 2.8 cm made in the 1975 and 1978 show variations of its radio brightness as a function of longitude on the planet (Doherty et al. , ApJ 233, 1979). In addition, an

  8. Boltzmann factor and Hawking radiation

    Ryskin, Gregory

    2014-01-01

    Hawking radiation has thermal spectrum corresponding to the temperature T H =(8πM) −1 , where M is the mass (energy) of the black hole. Corrections to the Hawking radiation spectrum were discovered by Kraus and Wilczek (1995) and Parikh and Wilczek (2000). Here I show that these corrections follow directly from the basic principles of thermodynamics and statistical mechanics. In essence, it is the Boltzmann factor that ought to be corrected; corrections to the Hawking (or any other) radiation spectrum then follow necessarily

  9. Correlated mixture between adiabatic and isocurvature fluctuations and recent CMB observations

    Andrade, Ana Paula A.; Wuensche, Carlos Alexandre; Ribeiro, Andre Luis Batista

    2005-01-01

    This work presents a reduced χ ν 2 test to search for non-Gaussian signals in the cosmic microwave background radiation (CMBR) TT power spectrum of recent CMBR data, Wilkinson Anisotropy Microwave Probe, Arcminute Cosmology Bolometer Array Receiver, and Cosmic Background Imager data sets, assuming a mixed density field including adiabatic and isocurvature fluctuations. We assume a skew positive mixed model with adiabatic inflation perturbations plus additional isocurvature perturbations possibly produced by topological defects. The joint probability distribution used in this context is a weighted combination of Gaussian and non-Gaussian random fields. Results from simulations of CMBR temperature for the mixed field show a distinct signature in CMB power spectrum for very small deviations (∼0.1%) from a pure Gaussian field, and can be used as a direct test for the nature of primordial fluctuations. A reduced χ ν 2 test applied on the most recent CMBR observations reveals that an isocurvature fluctuations field is not ruled out and indeed permits a very good description for a flat geometry Λ-CDM Universe, χ 930 2 ∼1.5, rather than the simple inflationary standard model with χ 930 2 ∼2.3. This result may looks is particular discrepant with the reduced χ 2 of 1.07 obtained with the same model in Spergel et al. [Astrophys. J. 148, 175 (2003)] for temperature only, however, our work is restricted to a region of the parameter space that does not include the best fit model for TT only of Spergel et al.

  10. Simulating the spectrum of neutrons produced by a radiation beam of high voltage inside an anthropomorphic phantom; Simulacion de espectro de nuetrones producido por un haz de radioterapia de alto voltaje en el interior de un manique antropomorfico

    Gonzalez-Soto, X.; Amgarou, K.; Langares, J. I.; Munez, J. L.; Mendez, R.; Exposito, M. R.; Gomez, F.; Domingo, C.; Sanche-Doblado, F.

    2011-07-01

    Our project aims to provide a universal method to estimate the dose deposited by neutrons in patients, using an anthropomorphic phantom. Both the detector response as relative biological effectiveness have a strong dependence on the energy spectrum of those, for this reason, a series of simulations were performed to calculate the spectrum of the neutron fluence in 16 representative points within the anthropomorphic phantom Standard for a full course of radiotherapy.

  11. Spectral backward radiation profile

    Kwon, Sung Duck; Lee, Keun Hyun; Kim, Bo Ra; Yoon, Suk Soo

    2004-01-01

    Ultrasonic backward radiation profile is frequency-dependent when incident region has deptional gradient of acoustical properties or multi-layers. Until now, we have measured the profiles of principal frequencies of used transducers so that it was not easy to understand the change of the frequency component and spectrum of backward radiation from the profile. We tried to measure the spectral backward radiation profiles using DFP(digital filer package) Lecroy DSO. The very big changes in the shape and pattern of spectral backward radiation profiles leads to the conclusion that this new try could be very effective tool to evaluate frequency dependent surface area.

  12. Simultaneous neutron and gamma spectrum adjustment

    Remec, I.

    1996-01-01

    The spectrum adjustment procedure was extended to simultaneous neutron and gamma spectrum adjustment, and the feasibility of this technique is demonstrated in the analysis of HFIR dosimetry experiments. Conditions in which gamma rays may contribute considerably to radiation damage in steels are discussed. Beryllium helium accumulation fluence monitors (HAFMs) were found to be good monitors in gamma fields of intensities high enough to contribute to steel embrittlement. Use of 237 Np, 238 U, and 9 Be HAFM as gamma dosimeters is proposed for high-dose irradiations in high-energy, high-intensity gamma fields

  13. What can we Learn from the Electromagnetic Spectrum?

    Electromagnetic radiation is all around us, and essential for the survival ... light that enters through the irises of our eyes, falls on our retina, interacts with ... tions of an electric charge produce an electromagnetic field that radiates ... induction of current in a coil. ... techniques showed that the violet end of visible spectrum oc-.

  14. Applying radiation

    Mallozzi, P.J.; Epstein, H.M.; Jung, R.G.; Applebaum, D.C.; Fairand, B.P.; Gallagher, W.J.; Uecker, R.L.; Muckerheide, M.C.

    1979-01-01

    The invention discloses a method and apparatus for applying radiation by producing X-rays of a selected spectrum and intensity and directing them to a desired location. Radiant energy is directed from a laser onto a target to produce such X-rays at the target, which is so positioned adjacent to the desired location as to emit the X-rays toward the desired location; or such X-rays are produced in a region away from the desired location, and are channeled to the desired location. The radiant energy directing means may be shaped (as with bends; adjustable, if desired) to circumvent any obstruction between the laser and the target. Similarly, the X-ray channeling means may be shaped (as with fixed or adjustable bends) to circumvent any obstruction between the region where the X-rays are produced and the desired location. For producing a radiograph in a living organism the X-rays are provided in a short pulse to avoid any blurring of the radiograph from movement of or in the organism. For altering tissue in a living organism the selected spectrum and intensity are such as to affect substantially the tissue in a preselected volume without injuring nearby tissue. Typically, the selected spectrum comprises the range of about 0.1 to 100 keV, and the intensity is selected to provide about 100 to 1000 rads at the desired location. The X-rays may be produced by stimulated emission thereof, typically in a single direction

  15. Soft component of channeled electron radiation in silicon crystals

    Vnukov, I.E.; Kalinin, B.N.; Kiryakov, A.A.; Naumenko, G.A.; Padalko, D.V.; Potylitsyn, A.P.

    2001-01-01

    Radiation spectrum and orientation dependences of photon yield with the energy much lower than characteristic radiation energy during channeling were measured using a crystal-diffraction spectrometer. For electron drop along axis radiation intensity in the spectral range 30 ≤ ω ≤ 360 keV exceeds by nearly an order the intensity of Bremsstrahlung. The shape of radiation spectrum does not coincide with Bremsstrahlung spectrum. Radiation intensity increases gradually with photons energy growth. Bremsstrahlung spectrum from a disoriented crystalline target is described in a satisfactory manner by the currently used theory with phenomenological account of the medium polarization [ru

  16. 5G Spectrum Sharing

    Nekovee, Maziar; Rudd, Richard

    2017-01-01

    In this paper an overview is given of the current status of 5G industry standards, spectrum allocation and use cases, followed by initial investigations of new opportunities for spectrum sharing in 5G using cognitive radio techniques, considering both licensed and unlicensed scenarios. A particular attention is given to sharing millimeter-wave frequencies, which are of prominent importance for 5G.

  17. Autism Spectrum Disorder (ASD)

    ... Español (Spanish) Recommend on Facebook Tweet Share Compartir Autism spectrum disorder (ASD) is a developmental disability that can cause ... work. Autism: What's New MMWR article: Prevalence of Autism Spectrum Disorder Data Community Report Press release: Autism Prevalence Slightly ...

  18. SU-E-T-359: Emulation of Yb-169 Gamma-Ray Spectrum Using Metal-Filtered 250 KVp X-Rays for Pre-Clinical Studies of Gold Nanoparticle-Aided Radiation Therapy

    Reynoso, F; Cho, S

    2015-01-01

    Purpose: To develop an external beam surrogate of the Yb-169 brachytherapy source applying a filter-based spectrum modulation technique to 250 kVp x-rays. In-vitro/vivo studies performed with the modulated 250 kVp beam will help gauge the benefits of implementing gold nanoparticle-aided radiotherapy with the Yb-169 source. Methods: A previously validated MCNP5 model of the Phillips RT-250 orthovoltage unit was used to obtain the percentage depth dose (PDD) and filtered photon spectra for a variety of filtration and irradiation conditions. Photon spectra were obtained using the average flux F4 tally in air right after all collimation. A 30 x 30 x 30 cm 3 water phantom was used to compute the PDD along the central axis (CAX) under the standards conditions of a 10 x 10 cm 2 field size at 50 cm SSD. Cylindrical cells of 4 cm in diameter and the energy deposition F6 tally were used along the CAX to score the doses down to 20 cm depth. The number of particle history was set to 2 x 10 8 in order to keep the relative uncertainty within each cell < 0.3%. The secondary electron spectrum within a gold-loaded tissue due to each photon spectrum was also calculated using EGSnrc and compared with that due to Yb-169 gamma rays. Results: Under the practical constraints for the spectrum modulation task, 250 kVp x-rays filtered by a 0.25 mm Erbium (Er) foil produced the best match with Yb-169 gamma rays, in terms of PDD and, more importantly, secondary electron spectrum. Conclusion: Modulation of 250kVp x-ray spectrum by an Er-filter was found effective in emulating the gamma ray spectrum of Yb-169. Possible benefits as predicted from the current MC model such as enhanced radiosensitization with the Er-filtered beam (as a surrogate of Yb-169) was confirmed with a separate in-vitro study. Supported by DOD/PCRP grant W81XWH-12-1-0198

  19. The RF spectrum: managing community health concerns

    Maclean, I.

    2001-01-01

    In this presentation I would like to share with you the way in which the Australian Communications Authority (ACA) goes about 'managing' community issues relating to the RF spectrum. In particular, I would like to refer to community issues associated with concerns about health. I will refer only briefly to the siting of mobile phone base stations as that will be covered elsewhere. Before getting into the community issues, I would like to provide some context about the ACA and the arrangements it has for regulating radiofrequency electromagnetic radiation (RF EMR). Copyright (2001) Australasian Radiation Protection Society Inc

  20. Theory of coherent transition radiation generated by ellipsoidal electron bunches

    Root, op 't W.P.E.M.; Smorenburg, P.W.; Oudheusden, van T.; Wiel, van der M.J.; Luiten, O.J.

    2007-01-01

    We present the theory of coherent transition radiation (CTR) generated by ellipsoidal electron bunches. We calculate analytical expressions for the electric field spectrum, the power spectrum, and the temporal electric field of CTR, generated by cylindrically symmetric ellipsoidal electron bunches

  1. Selective optical contacting for solar spectrum management

    Yang, Jianfeng; Chen, Weijian; Wang, Bo; Zhang, Zhilong; Huang, Shujuan; Shrestha, Santosh; Wen, Xiaoming; Patterson, Robert; Conibeer, Gavin

    2017-02-01

    Solar spectrum management using up/down conversion is an important method to improve the photovoltaic energy conversion efficiency. It asks for a monochromatic luminescence absorption at the band edge of the photovoltaic device to reduce both the sub-band-gap and over-band-gap energy losses. Here, we demonstrate an energy selective optical contacting concept to improve the luminescence transfer efficiency for spectrum management. By increasing both the luminescence emission and re-absorption ability through photonic resonance, an efficient photon transfer channel could be established between the luminescence emitter and the photovoltaic component in a near-field region. This concept is not only able to compensate the insufficient band edge absorption ability of the photovoltaic device, but also to break the far-field limitation of luminescence radiation. The energy selection on the optical spectrum naturally imposed by the mode resonance is also helpful to improve the monochromaticity of the luminescence yield. In this paper, a photonic crystal cavity is used to realize the optical contacting concept between a thin silicon film and spectrum converter. The optical power and photon flux transferred between different components are calculated analytically using the electromagnetic Green's function. The corresponding radiative dipole moment is estimated by the fluctuation-dissipation theorem. The example shows an over 80 times enhancement in the luminescence absorbance by the silicon layer, illustrating the great potential of this concept to be applied on nano-structured photovoltaic devices.

  2. The marine diversity spectrum

    Reuman, Daniel C.; Gislason, Henrik; Barnes, Carolyn

    2014-01-01

    of taxonomy (all the species in a region regardless of clade) are much less studied but are equally important and will illuminate a different set of ecological and evolutionary processes. We develop and test a mechanistic model of how diversity varies with body mass in marine ecosystems. The model predicts...... the form of the diversity spectrum', which quantifies the distribution of species' asymptotic body masses, is a species analogue of the classic size spectrum of individuals, and which we have found to be a new and widely applicable description of diversity patterns. The marine diversity spectrum...... is predicted to be approximately linear across an asymptotic mass range spanning seven orders of magnitude. Slope -0 center dot 5 is predicted for the global marine diversity spectrum for all combined pelagic zones of continental shelf seas, and slopes for large regions are predicted to lie between -0 center...

  3. Autism Spectrum Disorder

    This podcast discusses autism spectrum disorder (ASD), a developmental disability that causes problems with social, communication, and behavioral skills. CDC estimates that one in 68 children has been identified as having ASD.

  4. Fetal Alcohol Spectrum Disorders

    Alcohol can harm your baby at any stage during a pregnancy. That includes the earliest stages, before ... can cause a group of conditions called fetal alcohol spectrum disorders (FASDs). Children who are born with ...

  5. Fast Spectrum Reactors

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  6. Gluonium spectrum in QCD

    Dominguez, C.A.

    1987-02-01

    The scalar (0 ++ ) and the tensor (2 ++ ) gluonium spectrum is analyzed in the framework of QCD sum rules. Stable eigenvalue solutions, consistent with duality and low energy theorems, are obtained for the mass and width of these glueballs. (orig.)

  7. Hemodynamic changes induced by preventive exposure to terahertz radiation at a frequency range corresponding to molecular emission and absorption spectrum of nitric oxide in animals under conditions of acute stress.

    Kirichuck, V F; Velikanova, T S; Ivanov, A N

    2011-06-01

    We studied the influence of preventive irradiation with terahertz electromagnetic waves at frequencies corresponding to nitric oxide emission and absorption molecular spectrum (150,176-150,664 GHz) on hemodynamic parameters in arteries of albino rats upon acute immobilization stress. We showed that exposure to the specified frequencies can produce adaptogenic effect manifesting in the absence of post-stress changes in the linear, systolic, and diastolic blood flow velocities and pressure gradient in various blood vessels of experimental animals.

  8. Spectrum and network measurements

    Witte, Robert A

    2014-01-01

    This new edition of Spectrum and Network Measurements enables readers to understand the basic theory, relate it to measured results, and apply it when creating new designs. This comprehensive treatment of frequency domain measurements successfully consolidates all the pertinent theory into one text. It covers the theory and practice of spectrum and network measurements in electronic systems. It also provides thorough coverage of Fourier analysis, transmission lines, intermodulation distortion, signal-to-noise ratio and S-parameters.

  9. Radiation chemistry

    Rodgers, F.; Rodgers, M.A.

    1987-01-01

    The contents of this book include: Interaction of ionizing radiation with matter; Primary products in radiation chemistry; Theoretical aspects of radiation chemistry; Theories of the solvated electron; The radiation chemistry of gases; Radiation chemistry of colloidal aggregates; Radiation chemistry of the alkali halides; Radiation chemistry of polymers; Radiation chemistry of biopolymers; Radiation processing and sterilization; and Compound index

  10. Stimulated coherent transition radiation

    Hung-chi Lihn.

    1996-03-01

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed

  11. Autism spectrum disorder - Asperger syndrome

    ... part of the larger developmental disorder category of autism spectrum disorder . ... American Psychiatric Association. Autism spectrum disorder. ... VA: American Psychiatric Publishing: 2013;50-59. Raviola GJ, ...

  12. Radiation degradation of polymethacrylamide

    O'Connor, D.J.

    1984-01-01

    The effects of radiation on polymers have been studied for many years. When polymers are subjected to ultraviolet light or ionizing radiation, chain scission and crosslinking are possible. The radiation degradations of several methacrylate type polymers were investigated. The primary polymer studied was polymethacrylamide (PMAAm). Ultraviolet irradiated PMAAm yielded a five line ESR spectrum with 22 gauss splitting which is believed to arise from a polymeric radical ending with a methacrylamide unit. The results obtained indicate that polymethacrylamide is a polymer which undergoes main chain cleavage upon irradiation. As such this polymer may have potential applicability as a positive resist for fabrication of microelectronic devices

  13. ''Intelligent'' radiation measurements

    Ward, A.

    1980-01-01

    A description is given of three applications of current microprocessor technology which are characterized by the use of the microprocessor to impart a degree of intelligence to conventional radiation detection techniques. In the first application the microcomputer computes the radiation dose from the observed counting rate in a Geiger counter. In the second application the microcomputer provides the pulse height distribution and the radioisotopes used, from the spectrum of pulses from a scintillation counter. The third application is an arrangement for radiation monitor calibration. (H.K.)

  14. Unconventional application of the two-flux approximation for the calculation of the Ambartsumyan-Chandrasekhar function and the angular spectrum of the backward-scattered radiation for a semi-infinite isotropically scattering medium

    Remizovich, V. S.

    2010-06-01

    It is commonly accepted that the Schwarzschild-Schuster two-flux approximation (1905, 1914) can be employed only for the calculation of the energy characteristics of the radiation field (energy density and energy flux density) and cannot be used to characterize the angular distribution of radiation field. However, such an inference is not valid. In several cases, one can calculate the radiation intensity inside matter and the reflected radiation with the aid of this simplest approximation in the transport theory. In this work, we use the results of the simplest one-parameter variant of the two-flux approximation to calculate the angular distribution (reflection function) of the radiation reflected by a semi-infinite isotropically scattering dissipative medium when a relatively broad beam is incident on the medium at an arbitrary angle relative to the surface. We do not employ the invariance principle and demonstrate that the reflection function exhibits the multiplicative property. It can be represented as a product of three functions: the reflection function corresponding to the single scattering and two identical h functions, which have the same physical meaning as the Ambartsumyan-Chandrasekhar function ( H) has. This circumstance allows a relatively easy derivation of simple analytical expressions for the H function, total reflectance, and reflection function. We can easily determine the relative contribution of the true single scattering in the photon backscattering at an arbitrary probability of photon survival Λ. We compare all of the parameters of the backscattered radiation with the data resulting from the calculations using the exact theory of Ambartsumyan, Chandrasekhar, et al., which was developed decades after the two-flux approximation. Thus, we avoid the application of fine mathematical methods (the Wiener-Hopf method, the Case method of singular functions, etc.) and obtain simple analytical expressions for the parameters of the scattered radiation

  15. Investigation of influence of electronic irradiation on photoluminescence spectrum and ir-spectrum of porous silicon

    Daineko, E.A.; Dihanbayev, K.K.; Akhtar, P.; Hussain, A.

    2007-01-01

    In this article we study the influence of 2-Mev electron irradiation on porous silicon (PS). Photoluminescence (PL) spectrum and IR-spectrum have been done on both newly-prepared PS samples and samples prepared a year ago after the irradiation. We analyzed PL spectrum for both types of PS samples. The experimental results suggest that the peak position in PL spectrum decreases for newly-prepared PS samples. The size of the nanocrystals calculated by the method of singling out of spectrum components was equal to 3.0-3.2 nm. Porosity of the samples was 60-75%. From IR-spectrum of newly-prepared PS samples wide absorption band was observed at 1100 cm/sup -1/ (Si-O-Si bond). Another peak of Si-O-Si group was observed at 850 cm/sub -1/. Also hydrogen absorption bands were appearing from 2000 to 2200 cm/sup -1/, corresponding to vibration modes SiH, SiH/sub 2/, SiH/sub 3/. As a result of electron irradiation the PL intensity of newly-prepared PS samples decreases abruptly by a factor of 30 without peak shifting. As for the samples prepared a year ago we observed a decrease in the PL intensity by 25-30%. From IR-spectrum of PS samples prepared a year ago it was shown that the intensity of bridge bonds corresponding to absorption band 850 cm/sup -1/, decreases gradually. Our experimental data shows that PS samples stored for longer time have better radiation resistant properties than the newly-prepared PS samples due to the replacement of Si-H bonds with more resistant Si-O bonds. Porous silicon, electrochemical anodizing, photoluminescence spectrum, IR-spectrum, electronic irradiation. (author)

  16. Neutrino physics after boomerang

    Hannestad, Steen

    2001-01-01

    A new generation of Cosmic Microwave Background Radiation (CMBR) experiments are currently providing the first precision measurements of fluctuations in the CMBR. These fluctuations hold information about all the fundamental cosmological parameters, and the experiments have already confirmed beyond reasonable doubt that the geometry of the universe is very close to being flat. The new CMBR experiments can also be used to probe particle physics beyond the standard model. For instance, data from the new Boomerang experiment yield an upper limit on the effective number of neutrinos present at recombination, N ν ≤ 13 (95% C.L.). This already puts significant constraints on many non-standard neutrino scenarios, such as the possible bulk neutrino modes expected in theories with large extra dimensions. The upcoming satellite experiments will improve the sensitivity of the CMBR by almost an order of magnitude and make the CMBR an excellent laboratory for precision particle physics

  17. Advisory group on ionising radiation

    Harrison, J.R.

    1996-01-01

    The Advisory Group on Ionising Radiation has a busy and challenging work programme. Its reports will be published in the Documents of the NRPB series. These may advise further research or could form the basis of formal NRPB advice. Covering the full spectrum of radiation issues at work, in public health and clinical medicine, and the environment, it should enhance the radiation advice available to NRPB. (author)

  18. Control of Hazards to Health From Laser Radiation

    2006-01-01

    .... Medical guidance is limited to biological data available. This bulletin encompasses the portion of the electromagnetic spectrum in which laser radiation can be produced including: ultraviolet (UV...

  19. Research in radiation chemistry

    Silverman, J.

    1974-01-01

    In the survey the author discusses phenomena which are unique to radiation chemistry, as well as those in which radiation chemistry research plays a principal role. Works in this field such as spur phenomena and effects of scavengers in the radiolysis of water and liquid alkane, intraspur effects in styrene and polymerization of styrene at high dose rates are presented. The problem of the missing hydrogen atoms in irradiated alkanes needs answer and sensitization of crosslinking reactions may involve some unique aspects of radiation chemistry. Pairwise trapping of radicals in irradiated n-hydrocarbons have been observed in ESP-spectra. A well defined spectrum of radical pairs when the crystals of n-eicosane is irradiated and observed at 77 deg K. The nature of the spectrum, its changes with temperature and the effect of LET is discussed in the paper. (M.S.)

  20. Infrared Radiative Properties of Food Materials

    Precisely, infrared radiation is electromagnetic radiation whose wavelength is longer than that of visible light, but shorter than that of terahertz radiation and microwaves. The infrared portion of the electromagnetic spectrum spans roughly three orders of magnitude (750 nm to 100 µm) and has been...

  1. Radiation and radiation protection

    Landfermann, H.H.; Solbach, C.

    1992-11-01

    The brochure explains the major types of radiation, the radiation sources, effects, uses, and risks, as well as the regulatory system adopted by the government in order to keep the risks as low as possible. (orig./DG) [de

  2. Synchrotron radiation sources

    van Steenbergen, A.

    1979-01-01

    As a result of the exponential growth of the utilization of synchrotron radiation for research in the domain of the material sciences, atomic and molecular physics, biology and technology, a major construction activity has been generated towards new dedicated electron storage rings, designed optimally for synchrotron radiation applications, also, expansion programs are underway at the existing facilities, such as DORIS, SPEAR, and VEPP. In this report the basic properties of synchrotron radiation will be discussed, a short overview will be given of the existing and new facilities, some aspects of the optimization of a structure for a synchrotron radiation source will be discussed and the addition of wigglers and undulators for spectrum enhancement will be described. Finally, some parameters of an optimized synchrotron radiation source will be given.

  3. A new type gamma-ray spectrum monitoring system

    Cheng Bo; Zhou Jian Bin; Zhang Zhi Ming; Tong Yun Fu

    2002-01-01

    This new radiation monitoring system can be used to monitor the radiation of building materials and the radiation of atmosphere, to explore and evaluate rock for building in the field, and this system can be used to monitor the gamma irradiation near the nuclear establishments in the average situation and in the serious situation of the radiation incident have happened. The control core of this monitoring system is SCM-AT89C52, and gamma-ray sensing head consists of scintillator phi 50 mm x 50 mm NaI(Tl) and PMT GDB44. This system can be used to measure the whole gamma-ray spectrum of 256 channels

  4. Real time spectrum analysis

    Blunden, A.; O'Prey, D.G.; Tait, W.H.

    1983-01-01

    A method is described for the separation of a composite pulse-height spectrum into its unresolved component parts, which belong to a set of measured library spectra. The method allows real-time estimation giving running estimates during acquisition of the spectrum, minimises computation space, especially for a number of parallel calculations, estimates in advance the rms errors, and produces a significance measure for the hypothesis that the composite contains only the library spectra. Least squares curve-fitting, and other methods, can be compared, with the formalism developed, allowing analytical comparison of the effect of detector energy resolution and detection efficiency. A rational basis for the choice between the various methods of spectrum analysis follows from the theory, minimising rms estimation errors. The method described is applicable for very low numbers of counts and poor resolution. (orig.)

  5. Neuromyelitis Optica Spectrum Disorders.

    Akaishi, Tetsuya; Nakashima, Ichiro; Sato, Douglas Kazutoshi; Takahashi, Toshiyuki; Fujihara, Kazuo

    2017-05-01

    Neuromyelitis optica (NMO) is clinically characterized by severe optic neuritis and transverse myelitis, but recent studies with anti-aquaporin-4-antibody specific to NMO have revealed that the clinical spectrum is wider than previously thought. International consensus diagnostic criteria propose NMO spectrum disorders (NMOSD) as the term to define the entire spectrum including typical NMO, optic neuritis, acute myelitis, brain syndrome, and their combinations. NMOSD is now divided into anti-aquaporin-4-antibody-seropositive NMOSD and -seronegative NMOSD (or unknown serostatus). MR imaging and optical coherence tomography are indispensable in the diagnosis and evaluation of NMOSD. This article reviews the clinical and MR imaging findings of anti-aquaporin-4-antibody-seropositive and anti-myelin oligodendrocyte glycoprotein-antibody-seropositive NMOSD. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Bottomonium spectrum revisited

    Segovia, Jorge; Entem, David R.; Fernández, Francisco

    2016-01-01

    We revisit the bottomonium spectrum motivated by the recently exciting experimental progress in the observation of new bottomonium states, both conventional and unconventional. Our framework is a nonrelativistic constituent quark model which has been applied to a wide range of hadronic observables from the light to the heavy quark sector and thus the model parameters are completely constrained. Beyond the spectrum, we provide a large number of electromagnetic, strong and hadronic decays in order to discuss the quark content of the bottomonium states and give more insights about the better way to determine their properties experimentally.

  7. Surface Radiation Budget (SURFRAD) Network 1-Hour Observations

    National Oceanic and Atmospheric Administration, Department of Commerce — Radiation measurements at SURFRAD stations cover the range of the electromagnetic spectrum that affects the earth/atmosphere system. Direct solar radiation is...

  8. Radiation measurement

    Go, Sung Jin; Kim, Seung Guk; No, Gyeong Seok; Park, Myeong Hwan; Ann, Bong Seon

    1998-03-01

    This book explains technical terms about radiation measurement, which are radiation, radiation quantity and unit such as prefix of international unit, unit for defence purposes of radiation, coefficient of radiation and interaction, kinds and principles of radiation detector, ionization chamber, G-M counter, G-M tube, proportional counter, scintillation detector, semiconductor radiation detector, thermoluminescence dosimeter, PLD, others detector, radiation monitor, neutron detector, calibration of radiation detector, statistics of counting value, activation analysis and electronics circuit of radiation detector.

  9. Collisional redistribution of radiation. II - The effects of degeneracy on the equations of motion for the density matrix. III - The equation of motion for the correlation function and the scattered spectrum

    Burnett, K.; Cooper, J.

    1980-01-01

    The effect of correlations between an absorber atom and perturbers in the binary-collision approximation are applied to degenerate atomic systems. A generalized absorption profile which specifies the final state of the atom after an absorption event is related to the total intensities of Rayleigh scattering and fluorescence from the atom. It is suggested that additional dynamical information to that obtainable from ordinary absorption experiments is required in order to describe redistributed atomic radiation. The scattering of monochromatic radiation by a degenerate atom is computed in a binary-collision approximation; an equation of motion is derived for the correlation function which is valid outside the quantum-regression regime. Solutions are given for the weak-field conditions in terms of generalized absorption and emission profiles that depend on the indices of the atomic multipoles.

  10. The discrete Planck spectrum of a spherical cavity

    Vlad, V.I.; Ionescu-Pallas, N.

    1999-03-01

    The energy spectrum of black body radiation at the absolute temperature, T, in an ideal spherical cavity of radius, R, is studied. The departures from the classical predictions of Planck's theory, due to the discrete energies of the radiation quanta confined inside the cavity, depend on the adiabatic invariant RT and are significant for RT ≤ 40 cm · K. Special attention was paid to evidence strong changes in the spectrum intensities, forbidden bands of frequency, as well as major modifications of the total energy for RT ≤ 2 cm · K. Similar effects were present in the case of a cubic cavity. (author)

  11. Reconstructing Neutrino Mass Spectrum

    Smirnov, A. Yu.

    1999-01-01

    Reconstruction of the neutrino mass spectrum and lepton mixing is one of the fundamental problems of particle physics. In this connection we consider two central topics: (i) the origin of large lepton mixing, (ii) possible existence of new (sterile) neutrino states. We discuss also possible relation between large mixing and existence of sterile neutrinos.

  12. Autism Spectrum Disorder

    2014-04-02

    This podcast discusses autism spectrum disorder (ASD), a developmental disability that causes problems with social, communication, and behavioral skills. CDC estimates that one in 68 children has been identified as having ASD.  Created: 4/2/2014 by National Center on Birth Defects and Developmental Disabilities (NCBDDD).   Date Released: 4/2/2014.

  13. Strategic Vision for Spectrum

    2010-01-01

    maneuverable, flexible , and tactically effective. In the last few years, the rapid adoption of commercial communication tech- nologies has taxed...Logistics. The foundation that supports the mobility, flexibility , and precision necessary to accomplish these goals is the electromagnetic spectrum. 2...eGovernment, Enterprise Knowledge, Enterprise Licensing, Information Assurance, Librarian of the Navy, Organizational eLearning , Planning and Measurement

  14. Synchroton Radiation Sources

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

    1998-01-01

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

  15. Adaptation of closed cycle refrigeration system spectrum to radiation cryochemistry: γ-irradiation, ESR and optical absorption spectroscopy, ITL and RTL of frozen matrices at temperatures down to 14 K

    Mayer, J.; Plonka, A.; Ratajski, A.; Suwalski, J.P.; Wypych, M.

    1978-01-01

    The adaptation of the commercially available closed cycle refrigeration system Spectrim sup(TM) for radiation cryochemistry experiments with frozen matrices down to 14 K is described. The cold head of Spectrim sup(TM), equipped with vacuum shroud extensions and sample holders proper for the given type of experiments, was contained in lead shields, provided with special entrances for irradiation of samples with 60 Co γ-rays. The shroud extensions used for ESR and optical absorption measurements and the sample holders for isothermal luminescence and radiothermolumininescence measurements are described. (U.K.)

  16. Discrete quantum spectrum of black holes

    Lochan, Kinjalk, E-mail: kinjalk@iucaa.in; Chakraborty, Sumanta, E-mail: sumanta@iucaa.in

    2016-04-10

    The quantum genesis of Hawking radiation is a long-standing puzzle in black hole physics. Semi-classically one can argue that the spectrum of radiation emitted by a black hole look very much sparse unlike what is expected from a thermal object. It was demonstrated through a simple quantum model that a quantum black hole will retain a discrete profile, at least in the weak energy regime. However, it was suggested that this discreteness might be an artifact of the simplicity of eigen-spectrum of the model considered. Different quantum theories can, in principle, give rise to different complicated spectra and make the radiation from black hole dense enough in transition lines, to make them look continuous in profile. We show that such a hope from a geometry-quantized black hole is not realized as long as large enough black holes are dubbed with a classical mass area relation in any gravity theory ranging from GR, Lanczos–Lovelock to f(R) gravity. We show that the smallest frequency of emission from black hole in any quantum description, is bounded from below, to be of the order of its inverse mass. That leaves the emission with only two possibilities. It can either be non-thermal, or it can be thermal only with the temperature being much larger than 1/M.

  17. Radiation protection

    Koelzer, W.

    1975-01-01

    Physical and radiological terms, quantities, and units. Basic principles of radiation protection (ICRP, IAEA, EURATOM, FRG). Biological effects of ionizing radiation. Objectives of practical radiation protection. (HP) [de

  18. Full spectrum analysis in environmental monitoring

    Reinhardt, Sascha; Hartmann, Soeren; Pimpl, Richard

    2015-01-01

    In the environmental monitoring spectroscopic gamma detectors are frequently used. The motivation to use spectroscopic gamma detectors is the higher sensitivity and specific spectral information. For the analysis often the photo peaks of the gamma spectrum are used to identify the nuclide. These methods are very reliable, robust and well developed but using only the photo peak means also to use only a fraction of the available information. Doing a full spectrum analysis based on principle components obtained from NASVD for description of the radiation background and adjustment calculations are a possible analysis method which may provide advantages compared to a peak based analysis when used for a continuous environmental monitoring. An analysis example is shown and discussed with a measured time series of gamma spectra obtained from a spectroscopic gamma detector SARA IGS710 with a NaI(Tl) scintillator as it is used in the environmental monitoring.

  19. Full spectrum analysis in environmental monitoring

    Reinahrdt, S.; Hartmann, S.; Pimpl, R.

    2014-01-01

    In the environmental monitoring spectroscopic gamma detectors are frequently used. The motivation to use spectroscopic gamma detectors is the higher sensitivity and specific spectral information. For the analysis often the photo peaks of the gamma spectrum are used to identify the nuclide. These methods are very reliable, robust and well developed but using only the photo peak means also to use only a fraction of the available information. Doing a full spectrum analysis based on principal components obtained from NASVD for description of the radiation background and adjustment calculations are a possible analysis method, which may provide advantages compared to a peak based analysis when used for a continuous environmental monitoring. An analysis example is shown and discussed with a measured time series of gamma spectra obtained from a spectroscopic gamma detector SARA IGS710 with a NaI(Tl) scintillator as it is used in the environmental monitoring. (authors)

  20. Tm2+ luminescent materials for solar radiation conversion devices

    Van der Kolk, E.

    2015-01-01

    A solar radiation conversion device is described that comprises a luminescent Tm 2+ inorganic material for converting solar radiation of at least part of the UV and/or visible and/or infra red solar spectrum into infrared solar radiation, preferably said infrared solar radiation having a wavelength

  1. Treatment of domestic wastewater with an anaerobic ceramic membrane bioreactor (AnCMBR).

    Yue, Xiaodi; Koh, Yoong Keat Kelvin; Ng, How Yong

    2015-01-01

    In this study, a ceramic membrane with a pore size of 80 nm was incorporated into an anaerobic membrane bioreactor for excellent stability and integrity. Chemical oxygen demand (COD) removal efficiencies by biodegradation reached 78.6 ± 6.0% with mixed liquor suspended solids (MLSS) of 12.8 ± 1.2 g/L. Even though the total methane generated was 0.3 ± 0.03 L/g CODutilized, around 67.4% of it dissolved in permeate and was lost beyond collection. As a result, dissolved methane was 2.7 times of the theoretical saturating concentration calculated from Henry's law. When transmembrane pressure (TMP) of the ceramic membrane reached 30 kPa after 25.3 d, 95.2% of the total resistance was attributed to the cake layer, which made it the major contributor to membrane fouling. Compared to the mixed liquor, cake layer was rich in colloids and soluble products that could bind the solids to form a dense cake layer. The Methanosarcinaceae family preferred to attach to the ceramic membranes.

  2. Adaptive spectrum decision framework for heterogeneous dynamic spectrum access networks

    Masonta, M

    2015-09-01

    Full Text Available Spectrum decision is the ability of a cognitive radio (CR) system to select the best available spectrum band to satisfy dynamic spectrum access network (DSAN) users¿ quality of service (QoS) requirements without causing harmful interference...

  3. Characterization of radiation within the optical region

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

    1977-04-01

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

  4. Broadening the radiography spectrum

    Waswa, L.; Mutwasi, O.; Kioko, J.

    2006-05-01

    The text discuses the mammography in breast screening and evaluation of breast cancer; Small parts ultrasounds at plaza imaging solutions; role of a Radiographer in mammography-new perspective; Medical imaging education in africa; Caring for the paediatric patient as to broaden radiotherapy spectrum; Problems and challenges in care for children undergoing radiotherapy; Paediatric radiotherapy, management and side effects; The principles of pattern recognition of skeletal structures; the place of distance learning education in broadening the radiography spectrum; the curriculum and budgeting image; sonographer's guide; Computed radiography- X-Ray with vision; digital Radiography in Kenya today; Particle Therapy at Ithemba Labs; The role of lung perfusion and ventilation study in the evaluation of the pulmonary embolism and lastly, an overview of Head and neck treatment at Kenyatta National hospital radiotherapy

  5. Raman spectrum of asphaltene

    Abdallah, Wael A.; Yang, Yang

    2012-01-01

    Asphaltenes extracted from seven different crude oils representing different geological formations from around the globe were analyzed using the Raman spectroscopic technique. Each spectrum is fitted with four main peaks using the Gaussian function. On the basis of D1 and G bands of the Raman spectrum, asphaltene indicated an ordered structure with the presence of boundary defected edges. The average aromatic sheet size of the asphaltene molecules is estimated within the range of 1.52-1.88 nm, which represents approximately seven to eight aromatic fused rings. This estimation is based on the integrated intensity of D1 and G bands, as proposed by Tunistra and Koenig. The results here are in perfect agreement with so many other used techniques and indicate the potential applicability of Raman measurements to determine the average aromatic ring size and its boundary. © 2012 American Chemical Society.

  6. Raman spectrum of asphaltene

    Abdallah, Wael A.

    2012-11-05

    Asphaltenes extracted from seven different crude oils representing different geological formations from around the globe were analyzed using the Raman spectroscopic technique. Each spectrum is fitted with four main peaks using the Gaussian function. On the basis of D1 and G bands of the Raman spectrum, asphaltene indicated an ordered structure with the presence of boundary defected edges. The average aromatic sheet size of the asphaltene molecules is estimated within the range of 1.52-1.88 nm, which represents approximately seven to eight aromatic fused rings. This estimation is based on the integrated intensity of D1 and G bands, as proposed by Tunistra and Koenig. The results here are in perfect agreement with so many other used techniques and indicate the potential applicability of Raman measurements to determine the average aromatic ring size and its boundary. © 2012 American Chemical Society.

  7. Spread spectrum image steganography.

    Marvel, L M; Boncelet, C R; Retter, C T

    1999-01-01

    In this paper, we present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking.

  8. Occupational radiation safety in mining

    Stocker, H.

    1985-01-01

    The first International Conference on Occupational Radiation Safety in Mining was held three years ago in Golden, Colorado, U.S.A., and it provided an excellent forum for an exchange of information on the many scientific, technical and operational aspects of radiation safety in mining. I am aware of the broad spectrum of epidemiological, engineering and related studies which have been pursued during the past three years with a view to achieving further improvements in radiation protection and I expect that the information on these studies will contribute significantly to a wider understanding of subject, and in particular, the means by which radiation safety measures in mining can be optimized

  9. Radiation injuries and recovery

    Pauly, H.

    1974-01-01

    In memory of Prof. Dr. Langendorff, a survey and a cross-section are given of the development of radiobiology during the last 40 years. The importance of radiobiology is shown using several examples. The mechanisms and effects of radiation on man, animals and plants are discussed. Effects of radiation and radiolesious are explained down ot the molecular field, and their importance is discussed quantitatively with stochastic considerations. Stress is laid upon recovering from radiolesious. It is tried to explain recovery quantitatively in all its several sorts. Using all these deliberations, the author also tries to give a wide spectrum for radiation protection. These fundamental deliberations and works of Prof. Dr. Langendorff are guidelines of great importance also for radiation protection in connection with the protection of the civil population. (GSE) [de

  10. Hybrid spread spectrum radio system

    Smith, Stephen F [London, TN; Dress, William B [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  11. The synchrotron radiation

    Chevallier, P.

    1994-01-01

    Synchrotron Radiation is a fantastic source of electromagnetic radiation the energy spectrum of which spreads continuously from the far infrared to hard X-rays. For this reason a wide part of the scientific community, fundamentalists as well as industry, is concerned by its use. We shall describe here the main properties of this light source and give two examples of application in the field of characterization of materials: EXAFS (Extended X-Ray Absorption Fine Structure) and X-ray fluorescence. (author). 8 figs., 21 refs

  12. Asymmetric gain-saturated spectrum in fiber optical parametric amplifiers

    Lali-Dastjerdi, Zohreh; Rottwitt, Karsten; Galili, Michael

    2012-01-01

    We demonstrate experimentally and numerically an unexpected spectral asymmetry in the saturated-gain spectrum of single-pump fiber optical parametric amplifiers. The interaction between higher-order four-wave mixing products and dispersive waves radiated as an effect of third-order dispersion inf...... characteristics of the amplifier and shows local maxima for specific dispersion values....

  13. Fast radio burst search: cross spectrum vs. auto spectrum method

    Liu, Lei; Zheng, Weimin; Yan, Zhen; Zhang, Juan

    2018-06-01

    The search for fast radio bursts (FRBs) is a hot topic in current radio astronomy studies. In this work, we carry out a single pulse search with a very long baseline interferometry (VLBI) pulsar observation data set using both auto spectrum and cross spectrum search methods. The cross spectrum method, first proposed in Liu et al., maximizes the signal power by fully utilizing the fringe phase information of the baseline cross spectrum. The auto spectrum search method is based on the popular pulsar software package PRESTO, which extracts single pulses from the auto spectrum of each station. According to our comparison, the cross spectrum method is able to enhance the signal power and therefore extract single pulses from data contaminated by high levels of radio frequency interference (RFI), which makes it possible to carry out a search for FRBs in regular VLBI observations when RFI is present.

  14. Exploring a hidden fermionic dark sector

    Debasish Majumdar

    2017-10-09

    Oct 9, 2017 ... background radiation (CMBR) by Planck [1] satellite experiment suggests ... (SM) of particle physics also cannot explain the physics of dark matter. ... the dark sector also achieve mass from the spontaneous breaking of this ...

  15. SUBMILLIMETER POLARIZATION SPECTRUM IN THE VELA C MOLECULAR CLOUD

    Gandilo, Natalie N. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street Toronto, ON M5S 3H4 (Canada); Ade, Peter A. R.; Pascale, Enzo [Cardiff University, School of Physics and Astronomy, Queens Buildings, The Parade, Cardiff, CF24 3AA (United Kingdom); Angilè, Francesco E.; Devlin, Mark J.; Dober, Bradley; Galitzki, Nicholas; Klein, Jeffrey [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA, 19104 (United States); Ashton, Peter; Fissel, Laura M.; Matthews, Tristan G.; Novak, Giles [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Benton, Steven J. [Department of Physics, Princeton University, Jadwin Hall, Princeton, NJ 08544 (United States); Fukui, Yasuo [Department of Physics and Astrophysics, Nagoya University, Nagoya 464-8602 (Japan); Korotkov, Andrei L. [Department of Physics, Brown University, 182 Hope Street, Providence, RI, 02912 (United States); Li, Zhi-Yun [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Martin, Peter G. [CITA, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Moncelsi, Lorenzo [California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125 (United States); Nakamura, Fumitaka [National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Netterfield, Calvin B., E-mail: ngandil1@jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, 3701 San Martin Drive, Baltimore, Maryland (United States); and others

    2016-06-20

    Polarization maps of the Vela C molecular cloud were obtained at 250, 350, and 500 μ m during the 2012 flight of the balloon-borne telescope BLASTPol. These measurements are used in conjunction with 850 μ m data from Planck to study the submillimeter spectrum of the polarization fraction for this cloud. The spectrum is relatively flat and does not exhibit a pronounced minimum at λ ∼ 350 μ m as suggested by previous measurements of other molecular clouds. The shape of the spectrum does not depend strongly on the radiative environment of the dust, as quantified by the column density or the dust temperature obtained from Herschel data. The polarization ratios observed in Vela C are consistent with a model of a porous clumpy molecular cloud being uniformly heated by the interstellar radiation field.

  16. Radiation of dwarf novae

    Bruch, A.

    1987-01-01

    The nature of dwarf novae with their components white dwarf star, cool star, accretion disk, boundary layer and hot spot is investigated. It is shown that very different physical states and processes occur in the components of dwarf novae. Spectroscopical and photometrical observations are carried out. For better understanding the radiation portions of the single dwarf novae components are separated from the total electromagnetic spectrum recieved from the dwarf novae. The model assumptions are compared with the observations and verified

  17. Radiation crosslinking of polypropylene

    Nojiri, A.; Sawasaki, T.

    1984-01-01

    The radiation crosslinking of polypropylene with several kinds of polyfunctional monomers has been examined, and it has been clarified that the enhanced crosslinking may be classified into two types. In particular, the irradiation crosslinking process of polypropylene containing a polyfunctional monomer having an acryloyloxy group giving a specific gel - dose curve has been studied by infrared absorption spectrum and oxygen absorptivity measurement in comparison with the non-enhanced system. (author)

  18. Hawking Radiation As Tunneling

    Parikh, Maulik K.; Wilczek, Frank

    2000-01-01

    We present a short and direct derivation of Hawking radiation as a tunneling process, based on particles in a dynamical geometry. The imaginary part of the action for the classically forbidden process is related to the Boltzmann factor for emission at the Hawking temperature. Because the derivation respects conservation laws, the exact spectrum is not precisely thermal. We compare and contrast the problem of spontaneous emission of charged particles from a charged conductor

  19. The Relationship Between Dynamics and Structure in the Far Infrared Absorption Spectrum of Liquid Water

    Woods, K.

    2005-01-14

    Using an intense source of far-infrared radiation, the absorption spectrum of liquid water is measured at a temperature ranging from 269 to 323 K. In the infrared spectrum we observe modes that are related to the local structure of liquid water. Here we present a FIR measured spectrum that is sensitive to the low frequency (< 100cm{sup -1}) microscopic details that exist in liquid water.

  20. Air shower density spectrum

    Porter, M.R.; Foster, J.M.; Hodson, A.L.; Hazen, W.E.; Hendel, A.Z.; Bull, R.M.

    1982-01-01

    Measurements of the differential local density spectrum have been made using a 1 m 2 discharge chamber mounted in the Leeds discharge chamber array. The results are fitted to a power law of the form h(δ)dδ = kδsup(-ν)dδ, where ν=2.47+-0.04; k=0.21 s - 1 , for 7 m - 2 - 2 ; ν=2.90+-0.22; k=2.18 s - 1 , for δ > 200 m - 2 . Details of the measurement techniques are given with particular reference to the treatment of closely-spaced discharges. A comparison of these results with previous experiments using different techniques is made

  1. Spectrum of a one-atom laser in photonic crystals

    Florescu, Lucia

    2006-01-01

    The emission spectrum of a single-emitter laser in a photonic crystal is presented. We consider a coherently pumped two-level emitter strongly coupled to a high-quality microcavity engineered within a photonic crystal. We show that the cavity spectrum consists of both elastic and inelastic components, for which we derive analytical expressions. Our study reveals enhanced, spectrally narrower emission resulting from the radiation reservoir of the photonic crystal. The cavity field spectral characteristics are fundamentally distinct from those of a corresponding microcavity in ordinary vacuum. At high pump intensities and for large discontinuities in the photon density of states between Mollow spectral components of atomic resonance fluorescence, the emitted intensity originating from the elastic spectral component increases with the intensity of the pump and the elastic component dominates the spectrum. In the case of a vanishing photon density of states in the spectral range surrounding the lower Mollow sideband and no dipolar dephasing, the cavity spectrum is elastic

  2. Multiparticle-multihole configurations and photoproton spectrum from /sup 26/Mg nucleus

    Varlamov, V V; Zhivopistsev, F A; Ishkhanov, B S; Lukashev, A V [Moskovskii Gosudarstvennyi Univ. (USSR). Inst. Yadernoi Fiziki

    1975-01-01

    Results of calculating the spectrum of photoprotons for /sup 26/Mg nucleus within the framework of the model of multiparticle-multihole configurations are reported. The results obtained are compared to the experimental spectrum of photoprotons produced by means of bremsstrahlung radiation with maximum energy of Esub(..gamma..)sup(max)=32.0 MeV.

  3. Space radiation and astronaut safety

    Seedhouse, Erik

    2018-01-01

    This brief explores the biological effects of long-term radiation on astronauts in deep space. As missions progress beyond Earth's orbit and away from the protection of its magnetic shielding, astronauts risk constant exposure to higher levels of galactic cosmic rays and solar particle events. The text concisely addresses the full spectrum of biomedical consequences from exposure to space radiation and goes on to present possible ways to mitigate such dangers and protect astronauts within the limitations of existing technologies.

  4. Normalized noise power spectrum of full field digital mammography system

    Norriza Mohd Isa; Wan Muhamad Saridan Wan Hassan

    2009-01-01

    A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through detrending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality. (Author)

  5. Normalized Noise Power Spectrum of Full Field Digital Mammography System

    Isa, Norriza Mohd; Wan Hassan, Wan Muhamad Saridan

    2010-01-01

    A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through detrending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality.

  6. Recovering information of tunneling spectrum from weakly isolated horizon

    Chen, Ge-Rui; Huang, Yong-Chang [Beijing University of Technology, Institute of Theoretical Physics, Beijing (China)

    2015-02-01

    In this paper we investigate the properties of tunneling spectrum from weakly isolated horizon (WIH) - a locally defined black hole. We find that there exist correlations among Hawking radiations from a WIH, information can be carried out by such correlations, and the radiation is an entropy conservation process. Through revisiting the calculation of the tunneling spectrum from a WIH, we find that Zhang et al.'s (Ann Phys 326:350, 2011) requirement that radiated particles have the same angular momenta of a unit mass as that of the black hole is unnecessary, and the energy and angular momenta of the emitted particles are very arbitrary, restricted only by keeping the cosmic censorship hypothesis of black holes. So we resolve the information loss paradox based on the method of Zhang et al. (Phys Lett B 675:98, 2009; Ann Phys 326:350, 2011; Int J Mod Phys D 22:1341014, 2013) in a general case. (orig.)

  7. Ionizing radiation, radiation sources, radiation exposure, radiation effects. Pt. 2

    Schultz, E.

    1985-01-01

    Part 2 deals with radiation exposure due to artificial radiation sources. The article describes X-ray diagnosis complete with an analysis of major methods, nuclear-medical diagnosis, percutaneous radiation therapy, isotope therapy, radiation from industrial generation of nucler energy and other sources of ionizing radiation. In conclusion, the authors attempt to asses total dose, genetically significant dose and various hazards of total radiation exposure by means of a summation of all radiation impacts. (orig./WU) [de

  8. Clinical spectrum of onchodermatitis

    Bari, A.U.

    2007-01-01

    To describe the frequency and to see various dermatological presentations of onchocerciasis in black Africans of Sierra Leone. Local black patients of all age groups, attending dermatology outpatient department of Pak Field Hospital (established as a part of UN peacekeeping mission in Sierra Leone) with clinical diagnosis of onchodermatitis, based on symptomatology and morphological features of the disease, were included. UN troops were excluded. Laboratory investigations including blood complete picture and skin snips were carried out in all patients. Skin biopsy and nodule biopsy was performed in selected cases. Skin manifestations were recorded and categorized into various clinical patterns, i.e. acute, chronic, lichenified, onchocercoma, etc. Data was analyzed by using descriptive statistics in Instat. A total of 3011 patients, belonging to different local tribes, having a variety of skin disorders, were seen during the study period. One hundred and eighty-seven (6.2%) patients were found to have onchodermatitis. Patients were of all ages and both sexes, their ages ranging from 1 month to 73 years. Gender ratio was almost equal. A whole clinical spectrum of onchodermatitis was observed, chronic papular onchodermatitis being the most common pattern. Onchodermatitis with a large spectrum of clinical manifestations was seen in black Africans of the eastern part of Sierra Leone. (author)

  9. Supernovae anisotropy power spectrum

    Ghodsi, Hoda; Baghram, Shant [Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Habibi, Farhang, E-mail: h.ghodsi@mehr.sharif.ir, E-mail: baghram@sharif.edu, E-mail: habibi@lal.in2p3.fr [LAL-IN2P3/CNRS, BP 34, 91898 Orsay Cedex (France)

    2017-10-01

    We contribute another anisotropy study to this field of research using Type Ia supernovae (SNe Ia). In this work, we utilise the power spectrum calculation method and apply it to both the current SNe Ia data and simulation. Using the Union2.1 data set at all redshifts, we compare the spectrum of the residuals of the observed distance moduli to that expected from an isotropic universe affected by the Union2.1 observational uncertainties at low multipoles. Through this comparison we find a dipolar anisotropy with tension of less that 2σ towards l = 171° ± 21° and b = −26° ± 28° which is mainly induced by anisotropic spatial distribution of the SNe with z > 0.2 rather than being a cosmic effect. Furthermore, we find a tension of ∼ 4σ at ℓ = 4 between the two spectra. Our simulations are constructed with the characteristics of the upcoming surveys like the Large Synoptic Survey Telescope (LSST), which shall bring us the largest SNe Ia collection to date. We make predictions for the amplitude of a possible dipolar anisotropy that would be detectable by future SNe Ia surveys.

  10. First picosecond in radiation chemistry

    Bednar, J.

    1983-01-01

    The early processes of absorption by matter of ionizing radiation are discussed on the level of collision processes of electrons of the degradation spectrum of radiation with molecules of the medium. A short survey of the processes of initial excitations, superexcitations and ionizations is given occurring during absorption and relaxation processes. Collisions of fast charged particles with atoms and molecules are discussed within the first Bethe-Born approximation. A short theoretical description is given of the basic radiation chemical quantities, such as primary radiation chemical yield g and total absorbed energy Q/sub tot/ due to energy absorption from the totality of fast and slow electrons of the degradation spectrum. A short survey of current chemical and physical models of the track of a fast electron in condensed media is given together with some comments on the effect of the chemical composition of the medium on its initial radiation chemical decomposition. The model of the molecule in a high Rydberg state is sketched briefly together with some implications for radiation chemistry of formation and decay of this kind of highly excited matter. In conclusion, a survey of the initial yields of products in gases and track entities in liquids is presented and a few remarks are made concerning the intrinsic problems of radiation sciences, i.e. radiation physics, chemistry, dosimetry and biology

  11. Atoms, radiation, and radiation protection

    Turner, J.E.

    1986-01-01

    This book describes basic atomic and nuclear structure, the physical processes that result in the emission of ionizing radiations, and external and internal radiation protection criteria, standards, and practices from the standpoint of their underlying physical and biological basis. The sources and properties of ionizing radiation-charged particles, photons, and neutrons-and their interactions with matter are discussed in detail. The underlying physical principles of radiation detection and systems for radiation dosimetry are presented. Topics considered include atomic physics and radiation; atomic structure and radiation; the nucleus and nuclear radiation; interaction of heavy charged particles with matter; interaction of beta particles with matter; phenomena associated with charged-particle tracks; interaction of photons with matter; neutrons, fission and criticality; methods of radiation detection; radiation dosimetry; chemical and biological effects of radiation; radiation protection criteria and standards; external radiation protection; and internal dosimetry and radiation protection

  12. Natural radiation

    Feliciano, Vanusa Maria Delage

    2016-01-01

    Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included

  13. Radiation, people and the environment

    Ford, J.

    2004-02-01

    Radiation is a fact of life. We live in a world in which radiation is naturally present everywhere. Light and heat from nuclear reactions in the Sun are essential to our existence. Radioactive materials occur naturally throughout the environment, and our bodies contain radioactive materials such as carbon-14, potassium-40 and polonium-210 quite naturally. All life on Earth has evolved in the presence of this radiation. Since the discovery of X rays and radioactivity more than 100 years ago, we have found ways of producing radiation and radioactive materials artificially. The first use of X rays was in medical diagnosis, within six months of their discovery in 1895. So a benefit from the use of radiation was established very early on, but equally some of the potential dangers of radiation became apparent in the doctors and surgeons who unwittingly overexposed themselves to X rays in the early 1900s. Since then, many different applications of radiation and radioactive materials have been developed. We can classify radiation according to the effects it produces on matter, into ionizing and non-ionizing radiation. Ionizing radiation includes cosmic rays, X rays and the radiation from radioactive materials. Non-ionizing radiation includes ultraviolet light, radiant heat, radio waves and microwaves. This book deals with ionizing radiation, a term, which for simplicity, is often shortened to just radiation. It has been prepared by the International Atomic Energy Agency (IAEA) in co-operation with the National Radiological Protection Board (United Kingdom) as a broad overview of the subject of ionizing radiation, its effects and uses, as well as the measures in place to use it safely. As the United Nations agency for nuclear science and its peaceful applications, the IAEA offers a broad spectrum of expertise and programmes to foster the safe use of radiation internationally

  14. Epigenetic mechanism of radiation carcinogenesis

    Niwa, Ohtsura

    1995-01-01

    Carcinogenic action of radiations has long been thought to be due to its mutagenic activity. Since DNA damage is induced and distributes in a stochastic fashion, radiation induction of cancers was also assumed to follow a stochastic kinetics. However, recent progress in radiation research has revealed that some features of radiation carcinogenesis are not explainable by the simple action of radiation as a DNA damaging and mutagenic agent. Firstly, frequencies of radiation-induced transformation in vitro and radiation-induced mammary cancers in rats are too high to be accounted for by the frequency of radiation-induced mutation. Secondly, trans-generation carcinogenesis among F1 mice born to irradiated parents occurs also much more frequently than to be predicted by the frequency of radiation induced germline mutation. Thirdly, multistage carcinogenesis theory predicts that carcinogens give hits to the target cells so as to shorten the latency of cancers. However, latencies of radiation induced solid cancers among atomic bomb survivors are similar to those of the control population. Fourthly, although radiation elevates the frequency of cancers, the induced cancers seem to share the same spectrum of cancer types as in the unirradiated control populations. This suggests that radiation induces cancer by enhancement of the spontaneous carcinogenesis process. These data suggest that the first step of radiation carcinogenesis may not be the direct induction of mutation. Radiation may induce genetic instability which increases the spontaneous mutation rate in the cells to produce carcinogenic mutations. Growth stimulatory effect of radiation may also contribute to the process. Thus, epigenetic, but not genetic effect of radiation might better contribute in the process of carcinogenesis. (author)

  15. Diffraction of radiation from channelled charged particles

    Baryshevskij, V.G.; Grubich, A.O.; Dubovskaya, I.Ya.

    1978-01-01

    An explicit expression for cross-section and radiation spectrum at diffraction is calculated. It is shown that photons emitted by channelled particles form a typical diffraction pattern which contains information about the crystal structure. It is also shown that the change of the longitudinal energy of the particle caused by the radiation braking becomes important when the particle energy is increased. (author)

  16. Autism Spectrum Disorders

    Rebecca E. Rosenberg

    2011-01-01

    Full Text Available We used a national online registry to examine variation in cumulative prevalence of community diagnosis of psychiatric comorbidity in 4343 children with autism spectrum disorders (ASD. Adjusted multivariate logistic regression models compared influence of individual, family, and geographic factors on cumulative prevalence of parent-reported anxiety disorder, depression, bipolar disorder, and attention deficit/hyperactivity disorder or attention deficit disorder. Adjusted odds of community-assigned lifetime psychiatric comorbidity were significantly higher with each additional year of life, with increasing autism severity, and with Asperger syndrome and pervasive developmental disorder—not otherwise specified compared with autistic disorder. Overall, in this largest study of parent-reported community diagnoses of psychiatric comorbidity, gender, autistic regression, autism severity, and type of ASD all emerged as significant factors correlating with cumulative prevalence. These findings could suggest both underlying trends in actual comorbidity as well as variation in community interpretation and application of comorbid diagnoses in ASD.

  17. Electromagnetic spectrum management system

    Seastrand, Douglas R.

    2017-01-31

    A system for transmitting a wireless countermeasure signal to disrupt third party communications is disclosed that include an antenna configured to receive wireless signals and transmit wireless counter measure signals such that the wireless countermeasure signals are responsive to the received wireless signals. A receiver processes the received wireless signals to create processed received signal data while a spectrum control module subtracts known source signal data from the processed received signal data to generate unknown source signal data. The unknown source signal data is based on unknown wireless signals, such as enemy signals. A transmitter is configured to process the unknown source signal data to create countermeasure signals and transmit a wireless countermeasure signal over the first antenna or a second antenna to thereby interfere with the unknown wireless signals.

  18. Rotational spectrum of tryptophan

    Sanz, M. Eugenia, E-mail: maria.sanz@kcl.ac.uk; Cabezas, Carlos, E-mail: ccabezas@qf.uva.es; Mata, Santiago, E-mail: santiago.mata@uva.es; Alonso, Josè L., E-mail: jlalonso@qf.uva.es [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, Parque Científico Uva, Universidad de Valladolid, 47011 Valladolid (Spain)

    2014-05-28

    The rotational spectrum of the natural amino acid tryptophan has been observed for the first time using a combination of laser ablation, molecular beams, and Fourier transform microwave spectroscopy. Independent analysis of the rotational spectra of individual conformers has conducted to a definitive identification of two different conformers of tryptophan, with one of the observed conformers never reported before. The analysis of the {sup 14}N nuclear quadrupole coupling constants is of particular significance since it allows discrimination between structures, thus providing structural information on the orientation of the amino group. Both observed conformers are stabilized by an O–H···N hydrogen bond in the side chain and a N–H···π interaction forming a chain that reinforce the strength of hydrogen bonds through cooperative effects.

  19. Electromagnetic spectrum management system

    Seastrand, Douglas R.

    2017-10-17

    A system for transmitting a wireless countermeasure signal to disrupt third party communications is disclosed that include an antenna configured to receive wireless signals and transmit wireless counter measure signals such that the wireless countermeasure signals are responsive to the received wireless signals. A receiver processes the received wireless signals to create processed received signal data while a spectrum control module subtracts known source signal data from the processed received signal data to generate unknown source signal data. The unknown source signal data is based on unknown wireless signals, such as enemy signals. A transmitter is configured to process the unknown source signal data to create countermeasure signals and transmit a wireless countermeasure signal over the first antenna or a second antenna to thereby interfere with the unknown wireless signals.

  20. Spectrum of physics comprehension

    Blasiak, W; Godlewska, M; Rosiek, R; Wcislo, D

    2012-01-01

    The paper presents the results of research on the relationship between self-assessed comprehension of physics lectures and final grades of junior high school students (aged 13-15), high school students (aged 16-18) and physics students at the Pedagogical University of Cracow, Poland (aged 21). Students' declared level of comprehension was measured during a physics lecture on a prearranged scale of 1-10 with the use of a personal response system designed for the purpose of this experiment. Through the use of this tool, we obtained about 2000 computer records of students' declared comprehension of a 45 min lecture, which we named ‘the spectrum of comprehension’. In this paper, we present and analyse the correlation between students' declared comprehension of the content presented in the lecture and their final learning results. (paper)

  1. Infrared spectroscopy with synchrotron radiation

    Lagarde, P.

    1978-01-01

    Storage rings are normally used as sources of radiation in the X-ray and the u.v. part of the spectrum. It is shown that, with a specially designed component, a storage ring like ACO at Orsay is a very powerful far-infrared source, whose advantages over classical wide band sources are reviewed. (author)

  2. Stoppage in Autism Spectrum Disorders

    Grønborg, Therese Koops; Hansen, Stefan Nygaard; Nielsen, Svend V

    2015-01-01

    of bias in sibling recurrence risk estimation. This study investigated whether stoppage occurs in Danish families with a firstborn child diagnosed with autism spectrum disorders, and if stoppage was differential. We found that stoppage occurs moderately in Danish families affected by autism spectrum...... disorders, and that stoppage is differential. However, differential stoppage is a minor source of estimation bias in Danish sibling recurrence risk studies of autism spectrum disorders....

  3. Radiation induced pesticidal microbes

    Kim, Ki Yup; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.; Lim, D. S

    2001-01-01

    To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants.

  4. Radiation induced pesticidal microbes

    Kim, Ki Yup; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.; Lim, D. S.

    2001-01-01

    To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants

  5. Resonance detection of Moessbauer radiation

    Morozov, V.V.

    1985-01-01

    The resonance detection method as compared with the usual method of registering Moessbauer spectra has a number of advantages, one of which is the increase of resolution of the Moessbauer spectrum. The method is based on the modulation of a secondary radiation of a converter tuned in the resonance with the Moessbauer gamma-quantum source. The resonance detection method with account of supression, secondary radiation outgoing from the converter is investigated. The converter represents a substrate enriched by the Moessbauer isotope placed either inside the gas counter, or coupled with any other detecting device. Analytical expressions for Moessbauer spectrum parameters: effect, area and width of the spectral line are derived. It is shown that the joint application of usual and resonance detection methods for registering the Moessbauer spectrum allows one to determine parameters of the source, converter and the investigated absorber

  6. Regression in autistic spectrum disorders.

    Stefanatos, Gerry A

    2008-12-01

    A significant proportion of children diagnosed with Autistic Spectrum Disorder experience a developmental regression characterized by a loss of previously-acquired skills. This may involve a loss of speech or social responsitivity, but often entails both. This paper critically reviews the phenomena of regression in autistic spectrum disorders, highlighting the characteristics of regression, age of onset, temporal course, and long-term outcome. Important considerations for diagnosis are discussed and multiple etiological factors currently hypothesized to underlie the phenomenon are reviewed. It is argued that regressive autistic spectrum disorders can be conceptualized on a spectrum with other regressive disorders that may share common pathophysiological features. The implications of this viewpoint are discussed.

  7. Radiation enteritis

    Ochsner, S.F.; Head, L.H.

    1973-01-01

    A comprehensive review of radiation enteritis is presented. Experience in clinical radiation therapy has indicated that the small bowel is the segment of the alimentary tract that is most susceptible to radiation damage. (U.S.)

  8. Radiation monitor

    Pao, C.T.; Green, W.K.

    1978-01-01

    A system for indicating radiation from a radioactive fluid such as a gas wherein simultaneous indications of the activity concentration of radioactivity of the gas, the radiation dose rate and average energy of the radiation are provided

  9. Radiation protection

    Ures Pantazi, M.

    1994-01-01

    This work define procedures and controls about ionizing radiations. Between some definitions it found the following topics: radiation dose, risk, biological effects, international radioprotection bodies, workers exposure, accidental exposure, emergencies and radiation protection

  10. Radiation sickness

    ... exposure to ionizing radiation. There are two main types of radiation: nonionizing and ionizing. Nonionizing radiation comes in the form of light, radio waves, microwaves and radar. These forms usually don't cause tissue damage. ...

  11. Ionizing radiation

    Kruger, J.

    1989-01-01

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

  12. Induction linacs as radiation processors

    Birx, D.L.

    1986-01-01

    Experiments at the Lawrence Livermore National Laboratory (LLNL), University of California, in conjunction with the University of California at Davis have shown induction linear accelerators (linacs) to be suitable for radiation processing of food. Here we describe how it might be possible to optimize this technology developded for the Department of Defense to serve in radiation processing. The possible advantages of accelerator-produced radiation over the use of radioisotopes include a tailor-made energy spectrum that can provide much deeper penetration and thereby better dose uniformity

  13. Emission Spectrum Property of Modulated Atom-Field Coupling System

    Gao Yun-Feng; Feng Jian; Li Yue-Ke

    2013-01-01

    The emission spectrum of a two-level atom interacting with a single mode radiation field in the case of periodic oscillation coupling coefficient is investigated. A general expression for the emission spectrum is derived. The numerical results for the initial field in pure number stare are calculated. It is found that the effect of the coupling coefficient modulation on the spectral structure is very obvious in the case of a low modulation frequency and larger amplitude when the initial field is vacuum, which is potentially useful for exploring a modulated light source. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  14. Decay energy of 55Fe from its inner Bremsstrahlung spectrum

    Keshava, S. L.; Gopala, K.; Venkataramaiah, P.

    2001-06-01

    Several measurements of decay energy using the inner Bremsstrahlung spectrum (IB) due to radiative electron capture in 55Fe has been made. But the results are not uniform. Hence another attempt has been made at the same. Experimental data was obtained with a 4.445 cm. dia ' 5.08 cm thick NaI (Tl) detector. It was subjected to suitable statistical treatment and various corrections using Liden and Starfelt procedure. The corrected spectrum agrees well with the Glauber and Martin theory for 1s electron capture beyond 100 keV. From the Jauch plot, the decay energy of 232.36 +/-0.64 keV was obtained.

  15. Ultrarelativistic electron and positron radiation in planar channeling

    Kalashnikov, N.P.; Olchack, A.S.

    1980-01-01

    The coherent electromagnetic radiation from channeling electrons and positrons is given by similar expression. However for the channeling positrons the close collisions are suppressed due to the fact that the positron wave function is exponentially small near the atoms of the crystal lattice. It follows that the coherent bremsstrahlung decreases for the channeling positrons. We have investigated the ultrarelativistic channeling electron and positron radiations, connected with the electromagnetic transitions from the continuum spectrum states to the quasi-bound spectrum states and between the different quasi-bound spectrum states. The radiation probabilities are calculated by using the model continuum planar potential. It is shown that the radiation from the channeling electrons is several orders of magnitude larger than the positron radiation, while the electron and positron radiation have similar characteristics such as frequency limitation and angular distribution of the radiation. (orig.)

  16. Hawking radiation of a high-dimensional rotating black hole

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

    2010-01-15

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

  17. Neutron spectrum measurement in D + Be reaction

    Abbasi-Davani, F; Aslani, G R; Etaati, G R; Koohi-Fayegh, R

    2002-01-01

    In this project the neutron spectra from the reaction of deuteron on beryllium nuclei is measured. The energies of deuterons were 7, 10, 13 and 15 MeV, and these measurements are performed at 10,30 and 50 degrees relative to the beam of deuterons. The detector used is 76 by 76 mm right circular cylinder of N E-213 liquid scintillator. The zero crossing technique is used for gamma discrimination. For the elimination of the background radiation, a Polyethylene block, 40 cm in thickness, with inserted cadmium sheets, and a lead block, 5 cm in thickness, were used. In order to obtain the background radiation spectrum, the latter blocks were placed between the target and the detector to eliminate neutron and gamma radiations reaching the detector directly. sup F ORIST sup c ode is used to unfold the neutron spectra from the measured pulse high t spectra and sup O 5S sup a nd sup R ESPMG sup c odes are used to obtain the detector response matrix.

  18. Infrared metaphysics: the elusive ontology of radiator (part 1)

    Leonelli, S.; Chang, H.

    2005-01-01

    Hardly any ontological result of modern science is more firmly established than the fact that infrared radiation differs from light only in wavelength; this is part of the modern conception of the continuous spectrum of electromagnetic radiation reaching from radio waves to gamma radiation. Yet,

  19. Effects of X-rays spectrum on the dose

    Rodriguez I, J. L.; Hernandez A, P. L.; Vega C, H. R.; Rivera M, T.

    2015-10-01

    The X-ray equipment for diagnosis comes in different sizes and shapes depending on the scan type to perform. The X-ray spectrum is the energy distribution of the beam photons and consists of a continuous spectrum of photons braking and discrete spectrum due to the characteristic photons. The knowledge of the X-rays spectrum is important to understand like they affect the voltage changes (k Vp), current (m A), time (s) and the type of filter in the interaction mechanisms between X-rays and patient's body, the image receptor or other material that gets in the beam. Across the spectrum can be estimated the absorbed dose in any point of the patient, the quality of the image and the scattered radiation (which is related to the dose received by the equipment operator). The Monte Carlo method was used by MCNP5 code to calculate the spectrum of X-rays that occurs when a monoenergetic electron beam of 250 keV interact with targets of Mo, Rh and W. The spectra were calculated with and without filter, and the values of ambient dose equivalent were estimated, as well as the air kerma. (Author)

  20. PINS Spectrum Identification Guide

    A.J. Caffrey

    2012-03-01

    The Portable Isotopic Neutron Spectroscopy—PINS, for short—system identifies the chemicals inside munitions and containers without opening them, a decided safety advantage if the fill chemical is a hazardous substance like a chemical warfare agent or an explosive. The PINS Spectrum Identification Guide is intended as a reference for technical professionals responsible for the interpretation of PINS gamma-ray spectra. The guide is divided into two parts. The three chapters that constitute Part I cover the science and technology of PINS. Neutron activation analysis is the focus of Chapter 1. Chapter 2 explores PINS hardware, software, and related operational issues. Gamma-ray spectral analysis basics are introduced in Chapter 3. The six chapters of Part II cover the identification of PINS spectra in detail. Like the PINS decision tree logic, these chapters are organized by chemical element: phosphorus-based chemicals, chlorine-based chemicals, etc. These descriptions of hazardous, toxic, and/or explosive chemicals conclude with a chapter on the identification of the inert chemicals, e.g. sand, used to fill practice munitions.

  1. Structures in the primary spectrum

    Kempa, J.; Knurenko, S.P.; Malecki, R.

    2009-01-01

    Structures in the energy spectrum of primary cosmic rays at the 'knee' region and for energies higher than 1 EeV are obtained through studying extensive air showers (EAS). The main problem of the research is the fact that we work in the ranges of highly fluctuating parameters used to obtain the primary energy spectrum. In this paper the log-normal distribution for the error function has been used in convolution with the power spectrum to explain the Yakutsk experimental data. Similar results have been obtained for the gamma distribution as the error function. Using the power law primary spectrum in the energy region around 10 19 eV we will argue that the primary Yakutsk spectrum is overestimated. In the best case this overestimation is not less than 42%.

  2. Comparison of RF spectrum prediction methods for dynamic spectrum access

    Kovarskiy, Jacob A.; Martone, Anthony F.; Gallagher, Kyle A.; Sherbondy, Kelly D.; Narayanan, Ram M.

    2017-05-01

    Dynamic spectrum access (DSA) refers to the adaptive utilization of today's busy electromagnetic spectrum. Cognitive radio/radar technologies require DSA to intelligently transmit and receive information in changing environments. Predicting radio frequency (RF) activity reduces sensing time and energy consumption for identifying usable spectrum. Typical spectrum prediction methods involve modeling spectral statistics with Hidden Markov Models (HMM) or various neural network structures. HMMs describe the time-varying state probabilities of Markov processes as a dynamic Bayesian network. Neural Networks model biological brain neuron connections to perform a wide range of complex and often non-linear computations. This work compares HMM, Multilayer Perceptron (MLP), and Recurrent Neural Network (RNN) algorithms and their ability to perform RF channel state prediction. Monte Carlo simulations on both measured and simulated spectrum data evaluate the performance of these algorithms. Generalizing spectrum occupancy as an alternating renewal process allows Poisson random variables to generate simulated data while energy detection determines the occupancy state of measured RF spectrum data for testing. The results suggest that neural networks achieve better prediction accuracy and prove more adaptable to changing spectral statistics than HMMs given sufficient training data.

  3. Intermediate neutron spectrum problems and the intermediate neutron spectrum experiment

    Jaegers, P.J.; Sanchez, R.G.

    1996-01-01

    Criticality benchmark data for intermediate energy spectrum systems does not exist. These systems are dominated by scattering and fission events induced by neutrons with energies between 1 eV and 1 MeV. Nuclear data uncertainties have been reported for such systems which can not be resolved without benchmark critical experiments. Intermediate energy spectrum systems have been proposed for the geological disposition of surplus fissile materials. Without the proper benchmarking of the nuclear data in the intermediate energy spectrum, adequate criticality safety margins can not be guaranteed. The Zeus critical experiment now under construction will provide this necessary benchmark data

  4. Tachyonic cyclotron radiation

    Tomaschitz, R.

    2006-01-01

    We study superluminal cyclotron emission by electrons and muons in semiclassical orbits. The tachyonic line spectra of hydrogenic ions such as H, 56 Fe 25+ , and 238 U 91+ , as well as their muonic counterparts pμ - , 56 Fe 26+ μ - and 238 U 92+ μ - are calculated, in particular the tachyonic power transversally and longitudinally radiated, the total intensity, and the power radiated in the individual harmonics. We also investigate tachyonic continuum radiation from electrons and protons cycling in the surface and light cylinder fields of γ -ray and millisecond pulsars, such as the Crab pulsar, PSR B1509-58, and PSR J0218 + 4232. The superluminal spectral densities generated by non-relativistic, mildly relativistic and ultra-relativistic source particles are derived. We study the parameters determining the global shape of the transversal and longitudinal densities and the energy scales of the broadband spectrum. The observed cutoff frequency in the γ-ray band of the pulsars is used to infer the upper edge of the orbital energy, and we conclude that electrons and nuclei cycling in the surface fields can reach energies beyond the ''ankle'' of the cosmic ray spectrum. This suggests γ-ray pulsars as sources of ultra-high energy cosmic rays. (orig.)

  5. Effects of solar PAR and UV radiation on tropical biofouling communities

    Dobretsov, SV; Gosselin, L; Qian, P

    2010-01-01

    We investigated the effect of solar ultraviolet radiation (UVR) and photosynthetically active radiation (PAR) on the development of tropical micro- and macrofouling communities for 30 d. The experimental design involved 3 treatments: full spectrum

  6. Evaluate existing radiation fields

    Aldrich, J.M.; Haggard, D.L.; Endres, G.W.R.; Fix, J.J.

    1981-01-01

    Knowledge of the spectrum of energies for beta, gamma, and neutron radiation experienced in the field is crucial to the proper interpretation of personnel dose. Calibration sources and techniques are determined on the basis of their relationship to field exposure. Selected techniques were used to obtain neutron, photon, and beta energy spectra data at several Hanford locations. Four neutron energy spectra and dose measurement methods were used: (1) multisphere spectrometer system; (2) tissue equivalent proportional counter (TEPC); (3) RASCAL (9'' to 3'' sphere ratios); and (4) helium-3 neutron spectrometer. Gamma spectroscopy was done using standard techniques. A specially designed TLD dosimeter was used to obtain beta spectrum measurements. The design and use of each of these instruments is described in the body of this report. Data collected and analyzed for each of the Hanford locations are included

  7. Adult Autism Subthreshold Spectrum (AdAS Spectrum): Validation of a questionnaire investigating subthreshold autism spectrum.

    Dell'Osso, L; Gesi, C; Massimetti, E; Cremone, I M; Barbuti, M; Maccariello, G; Moroni, I; Barlati, S; Castellini, G; Luciano, M; Bossini, L; Rocchetti, M; Signorelli, M; Aguglia, E; Fagiolini, A; Politi, P; Ricca, V; Vita, A; Carmassi, C; Maj, M

    2017-02-01

    Increasing literature has shown the usefulness of a dimensional approach to autism. The present study aimed to determine the psychometric properties of the Adult Autism Subthreshold Spectrum (AdAS Spectrum), a new questionnaire specifically tailored to assess subthreshold forms of autism spectrum disorder (ASD) in adulthood. 102 adults endorsing at least one DSM-5 symptom criterion for ASD (ASDc), 143 adults diagnosed with a feeding and eating disorder (FED), and 160 subjects with no mental disorders (CTL), were recruited from 7 Italian University Departments of Psychiatry and administered the following: SCID-5, Autism-Spectrum Quotient (AQ), Ritvo Autism and Asperger Diagnostic Scale 14-item version (RAADS-14), and AdAS Spectrum. The AdAS Spectrum demonstrated excellent internal consistency for the total score (Kuder-Richardson's coefficient=.964) as well as for five out of seven domains (all coefficients>.80) and sound test-retest reliability (ICC=.976). The total and domain AdAS Spectrum scores showed a moderate to strong (>.50) positive correlation with one another and with the AQ and RAADS-14 total scores. ASDc subjects reported significantly higher AdAS Spectrum total scores than both FED (pcriteria (FED 0 ) and those with one ASD symptom criterion (FED 1 ) , a gradient of severity in AdAS Spectrum scores from CTL subjects to ASD patients, across FED 0 , ASD 1 , FED 1 was shown. The AdAS Spectrum showed excellent internal consistency and test-retest reliability and strong convergent validity with alternative dimensional measures of ASD. The questionnaire performed differently among the three diagnostic groups and enlightened some significant effects of gender in the expression of autistic traits. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Spectrum of a linear antenna in a cold magnetized plasma

    Eldridge, O.; Kritz, A.H.

    1975-04-01

    The fields radiated by a linear antenna in a cold magnetized plasma are calculated. The principal results are expressed in the input impedance and power spectrum of the near field, expressed as a function of the wavenumber or index of refraction parallel to the field. For frequencies below the electron plasma frequency and above the lower hybrid frequency the spectrum shows a broad maximum for short parallel wavelengths. The parallel index of refraction at this maximum is approximately the ratio of free space wavelength to antenna length. A spectrum of this sort is required by the accessibility conditions for heating at the lower hybrid resonance from a wave launched in a region of lower density. The impedance of a short antenna in this region is capacitive and a few hundred ohms in magnitude. (U.S.)

  9. Geographic Variations in the EPR Spectrum of Tooth Enamel

    Romanyukha, A.A.; Hayes, R.B.; Haskell, E.H.; Kenner, G.H.

    1999-01-01

    The presence of stable radiation-induced radicals in the mineral component of tooth enamel allows use of this material as a biological dosemeter. Estimation of the dose absorbed in tooth enamel can be done by EPR. Generally, for the purpose of dose reconstruction, the EPR spectrum of tooth enamel is interpreted in terms of two main components. The first is a broad background signal often called the native signal centered at a g value of 2.0045. The origin of this signal is not precisely known. The second main component in the tooth enamel spectrum is purely radiation induced and can be used for retrospective dosimetry. Internal structure of the native signal and variations of its amplitude and linewidth were investigated for the samples prepared from modern teeth obtained from different geographic locations (USA and Russia). Possible reasons for the variations observed are discussed as are the potential effects of the variations on the reliability of dose estimation. (author)

  10. Radiation practices and radiation measurements

    2008-03-01

    The guide presents the principal requirements on accuracy of radiation measurements and on the approval, calibration and operating condition inspections of radiation meters, together with requirements for dosimetric services measuring the individual radiation doses of workers engaged in radiation work (approved dosimetric services). The Guide also sets out the definitions of quantities and units used in radiation measurements. The radiation protection quantities used for assessing the harmful effects of radiation and for expressing the maximum values for radiation exposure (equivalent dose and effective dose) are set out in Guide ST 7.2. This Guide concerns measurements of ionizing radiation involved in radiation practices, the results of which are used for determining the radiation exposure of workers engaged in radiation work and members of the public, and of patients subject to the use of radiation in health services, or upon the basis of which compliance with safety requirements of appliances currently in use and of their premises of use or of the workplaces of workers is ensured. The Guide also concerns measurements of the radon concentration of inhaled air in both workplaces and dwellings. The Guide does not apply to determining the radiation exposure of aircrews, determination of exposure caused by internal radiation, or measurements made to protect the public in the event of, or in preparation for abnormal radiation conditions

  11. Measurements of neutron spectrum from uranium converter

    Ninkovic, M.; Sotic, O.; Marinkovic, S.

    1978-01-01

    The procedure for determination of energetic distribution of neutrons by the multisphere technique is given. The theoretical basis and features of the method are explained. The spectral distribution of neutrons emerging from the neutron converter constructed at the bare reactor assembly RB, has been determined applying the existing computer programme and literature data for the energetic dependence functions of spheres of various diameters. The obtained spectral distribution has a specific maximum in the domain of fast neutrons, justifying thus the reacton for the construction of the converter. The neutron spectrum data obtained and given in this report are very important for the use of the converter in neutron dosimetry and radiation protection, as well as in the radiobiology, shielding, reactor physics etc. (author)

  12. Neutron spectrum unfolding: Pt. 2

    Matiullah; Wiyaja, D.S.; Berzonis, M.A.; Bondars, H.; Lapenas, A.A.; Kudo, K.; Majeed, A.; Durrani, S.A.

    1991-01-01

    In Part I of this paper, we described the use of the computer code SAIPS in neutron spectrum unfolding. Here in Part II, we present our experimental work carried out to study the shape of the neutron spectrum in different experimental channels of a 5 MW light-water cooled and moderated research reactor. The spectral neutron flux was determined using various fission foils (placed in close contact with mica track detectors) and activation detectors. From the measured activities, the neutron spectrum was unfolded by SAIPS. (author)

  13. Multiple Beta Spectrum Analysis Method Based on Spectrum Fitting

    Lee, Uk Jae; Jung, Yun Song; Kim, Hee Reyoung [UNIST, Ulsan (Korea, Republic of)

    2016-05-15

    When the sample of several mixed radioactive nuclides is measured, it is difficult to divide each nuclide due to the overlapping of spectrums. For this reason, simple mathematical analysis method for spectrum analysis of the mixed beta ray source has been studied. However, existing research was in need of more accurate spectral analysis method as it has a problem of accuracy. The study will describe the contents of the separation methods of the mixed beta ray source through the analysis of the beta spectrum slope based on the curve fitting to resolve the existing problem. The fitting methods including It was understood that sum of sine fitting method was the best one of such proposed methods as Fourier, polynomial, Gaussian and sum of sine to obtain equation for distribution of mixed beta spectrum. It was shown to be the most appropriate for the analysis of the spectrum with various ratios of mixed nuclides. It was thought that this method could be applied to rapid spectrum analysis of the mixed beta ray source.

  14. Infrared Radiation and Blackbody Radiation

    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...

  15. New Measurements of the Cosmic Background Radiation Spectrum

    Smoot, G. F.; De Amici, G.; Levin, S.; Witebsky, C.

    The human genome project was borne of technology, grew into a science bureaucracy in the United States and throughout the world, and is now being transformed into a hybrid academic and commercial enterprise. The next phase of the project promises to veer more sharply toward commercial application, harnessing both the technical prowess of molecular biology and the rapidly growing body of knowledge about DNA structure to the pursuit of practical benefits. Faith that the systematic analysis of DNA structure will prove to be a powerful research tool underlies the rationale behind the genome project. The notion that most genetic information is embedded in the sequence of CNA base pairs comprising chromosomes is a central tenet. A rough analogy is to liken an organism's genetic code to computer code. The coal of the genome project, in this parlance, is to identify and catalog 75,000 or more files (genes) in the software that directs construction of a self-modifying and self-replicating system -- a living organism.

  16. Electromagnetic radiation properties of foods and agricultural products

    Mohsenin, N.N.

    1984-01-01

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

  17. Autism Spectrum Disorders (ASD) and Diet

    ... Conditions Autism Autism Spectrum Disorders (ASD) and Diet Autism Spectrum Disorders (ASD) and Diet By Karen Ansel, MS, RDN, CDN Published April 2, 2018 nambitomo/iStock/Thinkstock Autism Spectrum Disorder, or ASD, is a complex developmental and neurological ...

  18. Autism Spectrum Disorder and Fragile X Syndrome

    ... only after another family member has been diagnosed. Autism Spectrum Disorder and Fragile X Syndrome Fragile X syndrome is ... gene cause of ASD What Is Autism Spectrum Disorder? Autism spectrum disorder (ASD) is a behavioral diagnosis. The range ...

  19. Therapies for Children With Autism Spectrum Disorder

    ... With Autism Spectrum Disorder Therapies for Children With Autism Spectrum Disorder Consumer Summary September 23, 2014 Download PDF 692. ... Web page Understanding Your Child's Condition What is autism spectrum disorder (ASD)? ASD includes a range of behavioral symptoms. ...

  20. Polarizational radiation or 'atomic' bremsstrahlung

    Ya Amusia, M.

    1992-01-01

    It is demonstrated that a new kind of continuum spectrum radiation exists, where the mechanism of formation is quite different from that of ordinary bremsstrahlung. The latter originates due to slowing down of the charged projectile in the target field, while the former, called polarization radiation or 'atomic' bremsstrahlung, is a result of radiation either of the target or the projectile particles dipolarly polarized during the collision process. Not only general formulae, but also results of concrete calculations are presented. These demonstrate, that for electron-atom collisions the atomic contribution to the total bremsstrahlung spectrum becomes dominant for photon energies near and above the atomic ionization potential. As to atom-atom or ion-atom collisions, the bremsstrahlung spectrum is completely determined by the atomic contribution. The specific features of the case when the incoming particles are relativistic are discussed at length. A number of examples of colliding pairs are considered, for which the atomic bremsstrahlung process is quite essential: A bare nucleus and an atom, pair of atoms, at least one of which is excited, electron, or atom interacting with a molecule. The same mechanism is essential also in formation of radiation in nuclear and elementary particle collisions. (orig.)

  1. Family Process - Autism Spectrum Disorders

    Benson, Mark

    2012-01-01

    Slides for a talk about family process and the importance of parenting dimensions in adolescent development. The slides list findings to date, and propose research into the influence of family on outcomes for those diagnosed with an autism spectrum disorder.

  2. Directional spectrum of ocean waves

    Fernandes, A.A; Gouveia, A; Nagarajan, R.

    This paper describes a methodology for obtaining the directional spectrum of ocean waves from time series measurement of wave elevation at several gauges arranged in linear or polygonal arrays. Results of simulated studies using sinusoidal wave...

  3. New theoretical results in synchrotron radiation

    Bagrov, V.G. [Tomsk State University, Lenin Avenue 36, 634050 Tomsk (Russian Federation)]. E-mail: bagrov@phys.tsu.ru; Gitman, D.M. [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05315-970 Sao Paulo, SP (Brazil); Tlyachev, V.B. [Tomsk Institute of High Current Electronics, Akademicheskiy Avenue 4, Tomsk (Russian Federation); Jarovoi, A.T. [Tomsk State University, Lenin Avenue 36, 634050 Tomsk (Russian Federation)

    2005-11-15

    One of the remarkable features of the relativistic electron synchrotron radiation is its concentration in small angle {delta}{approx}1/{gamma} (here {gamma}-relativistic factor: {gamma}=E/mc{sup 2}, E - energy, m - electron rest mass, c - light velocity) near rotation orbit plane [V.G. Bagrov, V.A. Bordovitsyn, V.G. Bulenok, V. Ya. Epp, Kinematical projection of pulsar synchrotron radiation profiles, in: Proceedings of IV ISTC Scientific Advisory Commitee Seminar on Basic Science in ISTC Aktivities, Akademgorodok, Novosibirsk, April 23-27, 2001, p. 293-300]. This theoretically predicted and experimentally confirmed feature is peculiar to total (spectrum summarized) radiating intensity. This angular distribution property has been supposed to be (at least qualitatively) conserved and for separate spectrum synchrotron radiation components. In the work of V.G. Bagrov, V.A. Bordovitsyn, V. Ch. Zhukovskii, Development of the theory of synchrotron radiation and related processes. Synchrotron source of JINR: the perspective of research, in: The Materials of the Second International Work Conference, Dubna, April 2-6, 2001, pp. 15-30 and in Angular dependence of synchrotron radiation intensity. http://lanl.arXiv.org/abs/physics/0209097, it is shown that the angular distribution of separate synchrotron radiation spectrum components demonstrates directly inverse tendency - the angular distribution deconcentration relatively the orbit plane takes place with electron energy growth. The present work is devoted to detailed investigation of this situation. For exact quantitative estimation of angular concentration degree of synchrotron radiation the definition of radiation effective angle and deviation angle is proposed. For different polarization components of radiation the dependence of introduced characteristics was investigated as a functions of electron energy and number of spectrum component.

  4. The rotational spectrum of IBr

    Tiemann, E.; Moeller, T.

    1975-01-01

    The microwave spectrum of IBr was measured in the low rotational transition J = 3 → 2 in order to resolve the hyperfine structure as completely as possible. Rotational constants and quadrupole coupling constants were derived for both nuclei. The observation of the rotational spectrum in different vibrational states yields the vibrational dependence of the rotational constants as well as of the hyperfine parameters. The Dunham potential coefficients α 0 , α 1 , α 2 , α 3 are given. (orig.) [de

  5. Black hole quantum spectrum

    Corda, Christian [Institute for Theoretical Physics and Advanced Mathematics (IFM) Einstein-Galilei, Prato (Italy); Istituto Universitario di Ricerca ' ' Santa Rita' ' , Prato (Italy); International Institute for Applicable Mathematics and Information Sciences (IIAMIS), Hyderabad (India)

    2013-12-15

    Introducing a black hole (BH) effective temperature, which takes into account both the non-strictly thermal character of Hawking radiation and the countable behavior of emissions of subsequent Hawking quanta, we recently re-analysed BH quasi-normal modes (QNMs) and interpreted them naturally in terms of quantum levels. In this work we improve such an analysis removing some approximations that have been implicitly used in our previous works and obtaining the corrected expressions for the formulas of the horizon's area quantization and the number of quanta of area and hence also for Bekenstein-Hawking entropy, its subleading corrections and the number of micro-states, i.e. quantities which are fundamental to realize the underlying quantum gravity theory, like functions of the QNMs quantum ''overtone'' number n and, in turn, of the BH quantum excited level. An approximation concerning the maximum value of n is also corrected. On the other hand, our previous results were strictly corrected only for scalar and gravitational perturbations. Here we show that the discussion holds also for vector perturbations. The analysis is totally consistent with the general conviction that BHs result in highly excited states representing both the ''hydrogen atom'' and the ''quasi-thermal emission'' in quantum gravity. Our BH model is somewhat similar to the semi-classical Bohr's model of the structure of a hydrogen atom. The thermal approximation of previous results in the literature is consistent with the results in this paper. In principle, such results could also have important implications for the BH information paradox. (orig.)

  6. Black hole quantum spectrum

    Corda, Christian

    2013-12-01

    Introducing a black hole (BH) effective temperature, which takes into account both the non-strictly thermal character of Hawking radiation and the countable behavior of emissions of subsequent Hawking quanta, we recently re-analysed BH quasi-normal modes (QNMs) and interpreted them naturally in terms of quantum levels. In this work we improve such an analysis removing some approximations that have been implicitly used in our previous works and obtaining the corrected expressions for the formulas of the horizon's area quantization and the number of quanta of area and hence also for Bekenstein-Hawking entropy, its subleading corrections and the number of micro-states, i.e. quantities which are fundamental to realize the underlying quantum gravity theory, like functions of the QNMs quantum "overtone" number n and, in turn, of the BH quantum excited level. An approximation concerning the maximum value of n is also corrected. On the other hand, our previous results were strictly corrected only for scalar and gravitational perturbations. Here we show that the discussion holds also for vector perturbations. The analysis is totally consistent with the general conviction that BHs result in highly excited states representing both the "hydrogen atom" and the "quasi-thermal emission" in quantum gravity. Our BH model is somewhat similar to the semi-classical Bohr's model of the structure of a hydrogen atom. The thermal approximation of previous results in the literature is consistent with the results in this paper. In principle, such results could also have important implications for the BH information paradox.

  7. Beyond the Spectrum: Rethinking Autism

    Heather Thomas

    2017-03-01

    Full Text Available The "spectrum" has become the dominant metaphor for conceptualizing autism, with fundamental consequences for notions of disability, diversity, and normality. In this article, we draw on ethnographic research with autistic communities to explore how the notion of the autism spectrum has become a focus of explicit identification, reflection, and contestation. To further this inquiry, we place these debates into conversation with earlier debates regarding another spectrum—the Kinsey Scale, a "spectrum" for conceptualizing sexual orientation that first appeared in 1948 but has been critiqued since the 1970s. How might responses to the Kinsey Scale (like the Klein Grid contribute to rethinking the autism spectrum? This is a question about the cultural and political implications of metaphors and conceptual models. It is of broad importance because the spectrum metaphor is being extended to a range of conditions beyond autism itself. Our goal is thus to build on insights from sexuality studies as well as the insights of autistic persons, advocates, and researchers who wish to forestall the naturalization of "the spectrum." In doing so, we seek to contribute to a discussion of what alternative frameworks might bring to questions of social justice, ability, and human flourishing.

  8. Radiation safety

    Jain, Priyanka

    2014-01-01

    The use of radiation sources is a privilege; in order to retain the privilege, all persons who use sources of radiation must follow policies and procedures for their safe and legal use. The purpose of this poster is to describe the policies and procedures of the Radiation Protection Program. Specific conditions of radiation safety require the establishment of peer committees to evaluate proposals for the use of radionuclides, the appointment of a radiation safety officer, and the implementation of a radiation safety program. In addition, the University and Medical Centre administrations have determined that the use of radiation producing machines and non-ionizing radiation sources shall be included in the radiation safety program. These Radiation Safety policies are intended to ensure that such use is in accordance with applicable State and Federal regulations and accepted standards as directed towards the protection of health and the minimization of hazard to life or property. It is the policy that all activities involving ionizing radiation or radiation emitting devices be conducted so as to keep hazards from radiation to a minimum. Persons involved in these activities are expected to comply fully with the Canadian Nuclear Safety Act and all it. The risk of prosecution by the Department of Health and Community Services exists if compliance with all applicable legislation is not fulfilled. (author)

  9. Autism spectrum disorder - childhood disintegrative disorder

    ... part of the larger developmental disorder category of autism spectrum disorder . ... American Psychiatric Association. Autism spectrum disorder. ... VA: American Psychiatric Publishing: 2013;50-59. Raviola GJ, ...

  10. Radiation induced microbial pesticide

    Kim, Ki Yup; Lee, Young Keun; Kim, Jae Sung; Kim, Jin Kyu; Lee, Sang Jae

    2000-01-01

    To control plant pathogenic fungi, 4 strains of bacteria (K1, K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 13 kinds of fungi. Mutants of K1 and YS1 strains were induced by gamma-ray radiation and showed promising antifungal activities. These wild type and mutants showed resistant against more than 27 kinds of commercial pesticides among 30 kinds of commercial pesticides test particularly, YS1-1006 mutant strain showed resistant against hydrogen oxide. And mutants had increased antifungal activity against Botryoshaeria dothidea. These results suggested that radiation could be an useful method for the induction of functional mutants. (author)

  11. Radiation effects on polyethylenes

    Suzuki, T.; Oki, Y.; Numajiri, M.; Miura, T.; Kondo, K.; Tanabe, Y.; Ishiyama, M.; Ito, Y.

    1992-01-01

    Radiation effects on four kinds of polyethylenes were studied from the viewpoints of mechanical properties, free radicals and free volumes. The samples were irradiated using a cobalt 60 gamma source to give doses up to 3MGy. The degradation of mechanical strength due to gamma-irradiation was evaluated by the elongation at break and its tensile strength. Radiation induced free radicals were measured by ESR. Free volumes observed by the o-Ps component of the positron annihilation spectrum are normally the large ones located in the amorphous regions and after irradiation these are created in crystalline regions, too. The sizes and the relative numbers of free volumes were evaluated by lifetimes and intensities of a long-lived component of positronium, respectively. Using these data, the properties of polyethylenes before and after irradiation are discussed. (author)

  12. Radiation safety

    Woods, D.A.

    1982-01-01

    Sections include: dose units, dose limits, dose rate, potential hazards of ionizing radiations, control of internal and external radiation exposure, personal dosemeters, monitoring programs and transport of radioactive material (packaging and shielding)

  13. Synchrotron radiation

    Hallmeier, K.H.; Meisel, A.; Ranft, J.

    1982-01-01

    The physical background and the properties of synchrotron radiation are described. The radiation offers many useful applications in the fields of spectroscopy and structural investigations. Some examples are given

  14. Radiation monitoring

    Larsson, L.Eh.; B'yuli, D.K.; Karmikel, Dzh.Kh.E.

    1985-01-01

    Recommendations on radiation monitoring of personnel, used medical ionizing radiation source, are given. The necessity to carry out radiation monitoring of situation at medical personnel's positions and personnel dosimetry is marked. It is convenient to subdivide radiation monitoring into 3 types: usual, surgical and special. Usual monitoring is connected with current work; surgical monitoring is carried out to receive information during a concrete operation; special monitoring is used to detect possible deviation from standard conditions of work or when suspecting them

  15. Medical radiation

    1992-01-01

    This leaflet in the At-a-Glance Series describes the medical use of X-rays, how X-rays help in diagnosis, radiation protection of the patient, staff protection, how radioactive materials in nuclear medicine examinations help in diagnosis and the use of radiation in radiotherapy. Magnetic resonance imaging, a diagnostic technique involving no ionizing radiation, is also briefly examined. The role of the NRPB in the medical use of radiation is outlined. (UK)

  16. Superluminescence of cadmium sulfide crystals under pulse X-ray radiation

    Pavlovskaya, N.G.; Tarasov, M.D.; Balakin, V.A.; Varava, V.P.; Lobov, S.I.; Surskij, O.K.; Tsukerman, V.A.

    1977-01-01

    Studies were made to elucidate luminescence properties of CdS crystal radiated by short pulses of braking x-ray radiation. Such a radiation causes the appearance of superluminescence. The radiation was carried out at 295 and 170 K, the radiation dose being changed from 3600 to 1600 r/pulse. At the temperature of 295 K light luminescence was registered at the wave length of 528 nm and half-width of 15 nm. While the temperature lowers, the radiation shifts to the range of shorter wave lengths, and a decrease of the spectrum half-width is observed. With the increase of radiation dose the decrease of radiation spectrum half-width is observed. Approximate calculations show that to achieve the spectrum narrowing to 1 nm at room temperature it is necessary to increase radiation dose per pulse 5-6 times

  17. Ionizing radiation

    Dennis, J.A.

    1982-01-01

    The subject is discussed under the headings: characteristics of ionizing radiations; biological effects; comparison of radiation and other industrial risks; principles of protection; cost-benefit analysis; dose limits; the control and monitoring of radiation; reference levels; emergency reference levels. (U.K.)

  18. Radiation watchdog

    Manning, R.

    1984-01-01

    Designated by WHO as a Collaborating Centre, the Radiation Emergency Assistance Center/Training Site (REAC/TS) in Oak Ridge, Tennessee provides assistance to all countries of the Americas in radiation accidents including human contamination or overexposure. It also conducts courses in radiation emergency response for health professionals from throughout the world

  19. Radiation hazards

    Rausch, L.

    1979-01-01

    On a scientific basis and with the aid of realistic examples, the author gives a popular introduction to an understanding and judgment of the public discussion over radiation hazards: Uses and hazards of X-ray examinations, biological radiation effects, civilisation risks in comparison, origins and explanation of radiation protection regulations. (orig.) [de

  20. High-frequency asymptotics of the emission spectrum of moving charged particles in classical electrodynamics

    Abbasov, I.I.; Bolotovskij, B.M.; Davydov, V.A.

    1986-01-01

    Electromagnetic radiation appears as a result of a charged particle movement in free space and also in heterogeneous and non-stationary medium. The radiation spectrum depends on the charged particle motion law, as well as on the law of the medium property chage in space and time. The asymptotics of radiation spectrum, i.e. behaviour of spectral intensity at high frequencies, is studied. It is shown that if a charged particle moves along smooth trajectory or if the change in the medium properties takes place accordng to the law described by a smooth function, the radiation spectrum at high frequencies decreases according to exponential law. Thus, radiation spectrum of a charged particle moving along a smooth trajectory in the medium with gradual heterogeneity and (or) instability is rapidly cut, starting from a certain frequency value. The smooth trajectory means that the charge moves according to the law r = r(t), where vector-function r(t) is continuous with all its derivatives. In much the same way the medium with gradual heterogeneities (or with gradual instability) is described by the functions which are continuous with all their derivatives of any order. The method permitting to determine the upper boundary of radiation spectra is presented

  1. Radiating properties of solar plasmas

    Bruner, M. E.; Mcwhirter, R. W. P.

    1988-01-01

    Using a series of 14 previously obtained empirical emission measure distributions and a number of spectral lines observed by the SMM and P78-1 instruments, the total power radiated by a hot plasma is compared to that radiated by individual spectrum lines. Results are presented for different choices of ionization balance and power loss functions. The results indicate that for some lines such as the C IV resonance doublet at 1548 A and 1550 A, the ratio of the line intensity to the total radiated power varied only over a factor of 2, suggesting that well-calibrated measurements of a single line intensity may provide a fairly good estimation of the total radiated power output from the solar plasma.

  2. Radiating properties of solar plasmas

    Bruner, M.E.; Mcwhirter, R.W.P.

    1988-01-01

    Using a series of 14 previously obtained empirical emission measure distributions and a number of spectral lines observed by the SMM and P78-1 instruments, the total power radiated by a hot plasma is compared to that radiated by individual spectrum lines. Results are presented for different choices of ionization balance and power loss functions. The results indicate that for some lines such as the C IV resonance doublet at 1548 A and 1550 A, the ratio of the line intensity to the total radiated power varied only over a factor of 2, suggesting that well-calibrated measurements of a single line intensity may provide a fairly good estimation of the total radiated power output from the solar plasma. 21 references

  3. Statistical moments of the angular spectrum of normal waves in a turbulent collisional magnetized plasma

    Aistov, A.V.; Gavrilenko, V.G.

    1996-01-01

    The normal incidence of a small-amplitude electromagnetic wave upon a semi-infinite turbulent collisional plasm with an oblique external magnetic field is considered. Within a small-angle-scattering approximation of the radiative transport theory, a system of differential equations is derived for statistical moments of the angular power spectrum of radiation. The dependences of the spectrum centroid, dispersion, and asymmetry on the depth of penetration are studied numerically. The nonmonotonic behavior of the dispersion is revealed, and an increase in the spectrum width with absorption anisotropy is found within some depth interval. It is shown that, at large depths, the direction of the displacement of the spectrum centroid, does not always coincide with the direction of minimum absorption

  4. Superposition of Planckian spectra and the distortions of the cosmic microwave background radiation

    Alexanian, M.

    1982-01-01

    A fit of the spectrum of the cosmic microwave background radiation (CMB) by means of a positive linear superposition of Planckian spectra implies an upper bound to the photon spectrum. The observed spectrum of the CMB gives a weighting function with a normalization greater than unity

  5. Anomalous x-ray radiation of beam plasma

    Dimitrov, S.K.; Zavyalov, M.A.; Mikhin, S.G.; Tarasenkov, V.A.; Telkovskij, V.G.; Khrabrov, V.A.

    1985-01-01

    The properties of non-equilibrium stationary plasma under the conditions of the planned plasma-chemical reactors based on beam-plasma discharge were investigated. The x-ray spectrum of the beam-plasma was measured and anomalous spectral properties were analyzed. Starting with some critical pressure the anomalous radiation was added to the classical bremsstrahlung spectrum. The occurrence of anomalous radiation can be used to diagnose the condition of beam transportation in such systems. (D.Gy.)

  6. Ionizing radiations

    Newton, W.

    1984-01-01

    The purpose of this article is to simplify some of the relevant points of legislation, biological effects and protection for the benefit of the occupational health nurse not familiar with the nuclear industries. The subject is dealt with under the following headings; Understanding atoms. What is meant by ionizing radiation. Types of ionizing radiation. Effects of radiation: long and short term somatic effects, genetic effects. Control of radiation: occupational exposure, women of reproductive age, medical aspects, principles of control. The occupational health nurse's role. Emergency arrangements: national arrangements for incidents involving radiation, action to be taken by the nurse. Decontamination procedures: external and internal contamination. (U.K.)

  7. Radiation imaging

    Redmayne, I.

    1986-05-21

    A detector for the detection of radiation such as X-ray radiation comprises an array of scintillation elements embedded in a sheet of radiation absorbing material. The scintillation elements are monitored individually, for example by a corresponding array of photodiodes, to build up a picture of the incident radiation. The front face of the sheet and the inner walls of the bores may be coated with a reflective material. The detector finds particular application in weld radiography. The detector may be stepped relative to the radiation source, the signals produced by the rows of the detector as they pass a predetermined point being summed.

  8. Radiation imaging

    Redmayne, Ian.

    1986-01-01

    A detector for the detection of radiation such as X-ray radiation comprises an array of scintillation elements embedded in a sheet of radiation absorbing material. The scintillation elements are monitored individually, for example by a corresponding array of photodiodes, to build up a picture of the incident radiation. The front face of the sheet and the inner walls of the bores may be coated with a reflective material. The detector finds particular application in weld radiography. The detector may be stepped relative to the radiation source, the signals produced by the rows of the detector as they pass a predetermined point being summed. (author)

  9. Search for radiative B meson decays

    Lesiak, T.; Muryn, B.; Nowak, G.; Antreasyan, D.; Irion, J.; McBride, P.; Strauch, K.; Bartels, H.W.; Bienlein, J.K.; Brockmueller, K.; Jakubowski, Z.; Karch, K.; Kloiber, T.; Koch, W.; Maschmann, W.; Meyer, H.; Skwarnicki, T.; Trost, H.J.; Voigt, A.; Wachs, K.; Zschorsch, P.; Besset, D.; Cabenda, R.; Cowan, R.; Bieler, C.; Graaf, K.; Heinsius, F.H.; Kiel, T.; Krueger, S.; Lekebusch, R.; Nernst, R.; Sievers, D.; Stock, V.; Strohbusch, U.; Bloom, E.D.; Clare, R.; Cooper, S.; Fairfield, K.; Fridman, A.; Gaiser, J.; Gelphman, D.; Godfrey, G.; Hofstadter, R.; Kirkbride, I.; Lee, R.; Leffler, S.; Litke, A.M.; Lockman, W.; Lowe, S.; Niczyporuk, B.; Pollock, B.; Schwarz, A.; Tompkins, J.; Van Uitert, B.; Wacker, K.; Brock, I.; Engler, A.; Kraemer, R.W.; Marlow, D.; Messing, F.; Prindle, D.; Renger, B.; Rippich, C.; Vogel, H.; Cavalli-Sforza, M.; Coyne, D.; Folger, G.; Glaser, G.; Kobel, M.; Lurz, B.; Schuette, J.; Volland, U.; Wegener, H.; Janssen, H.; Koenig, A.C.; Metzger, W.J.; Reidenbach, M.; Schotanus, J.; Walle, R.T. van de; Walk, W.; Keh, S.; Kilian, H.; Koenigsmann, K.; Scheer, M.; Schmitt, P.; Marsiske, H.; Peck, C.; Porter, F.C.; Ratoff, P.; Williams, D.A.

    1991-07-01

    The Crystal Ball detector at the ε + ε - storage ring DORIS-II has been used to search for radiative B meson decays, especially of the type b→sγ. No mono-energetic γ-lines have been found in the inclusive photon spectrum from Υ(4S) decays, and upper limits are obtained for radiative decays of B mesons to various strange mesons and to the D*. Integrating the photon spectrum over the corresponding energy range, we find BR(B→γX) -3 at 90% confidence level for the mass range 892 MeV≤M X ≤2045 MeV. (orig.)

  10. Search for radiative B meson decays

    Lesiak, T.; Muryn, B.; Nowak, G.; Antreasyan, D.; Irion, J.; McBride, P.; Strauch, K.; Bartels, H.W.; Bienlein, J.K.; Brockmueller, K.; Jakubowski, Z.; Karch, K.; Kloiber, T.; Koch, W.; Maschmann, W.; Meyer, H.; Skwarnicki, T.; Trost, H.J.; Voigt, A.; Wachs, K.; Zschorsch, P.; Besset, D.; Cabenda, R.; Cowan, R.; Bieler, C.; Graaf, K.; Heinsius, F.H.; Kiel, T.; Krueger, S.; Lekebusch, R.; Nernst, R.; Sievers, D.; Stock, V.; Strohbusch, U.; Bloom, E.D.; Clare, R.; Cooper, S.; Fairfield, K.; Fridman, A.; Gaiser, J.; Gelphman, D.; Godfrey, G.; Hofstadter, R.; Kirkbride, I.; Lee, R.; Leffler, S.; Litke, A.M.; Lockman, W.; Lowe, S.; Niczyporuk, B.; Pollock, B.; Schwarz, A.; Tompkins, J.; Van Uitert, B.; Wacker, K.; Brock, I.; Engler, A.; Kraemer, R.W.; Marlow, D.; Messing, F.; Prindle, D.; Renger, B.; Rippich, C.; Vogel, H.; Cavalli-Sforza, M.; Coyne, D.; Folger, G.; Glaser, G.; Kobel, M.; Lurz, B.; Schuette, J.; Volland, U.; Wegener, H.; Janssen, H.; Koenig, A.C.; Metzger, W.J.; Reidenbach, M.; Schotanus, J.; Walle, R.T. van de; Walk, W.; Keh, S.; Kilian, H.; Koenigsmann, K.; Scheer, M.; Schmitt, P.; Marsiske, H.; Williams, D.A.

    1992-01-01

    The Crystal Ball detector at the e + e - storage ring DORIS-II has been used to search for radiative B meson decays, especially of the type b→sγ. No mono-energetic γ-lines have been found in the inclusive photon spectrum from Υ(4S) decays, and upper limits are obtained for radiative decays of B mesons to various strange mesons and to the D*. Integrating the photon spectrum over the corresponding energy range, we find BR(B→γX) -3 , at 90% confidence level for the mass range 892 MeV≤M X ≤2045 MeV. (orig.)

  11. Scintillation counter based radiation dosimeter

    Shin, Jeong Hyun

    2009-02-01

    The average human exposure per year is about 240mrem which is come from Radon and human body and terrestrial and cosmic radiation and man-made source. Specially radiation exposure through air from environmental radiation sources is 80mrem/yr(= 0.01mR/hr) which come from Terrestrial and cosmic radiation. Radiation dose is defined as energy deposit/mass. There are two major methods to detect radiation. First method is the energy integration using Air equivalent material like GM counter wall material. Second method is the spectrum to dose conversion method using NaI(Tl), HPGe. These two methods are using generally to detect radiation. But these methods are expensive. So we need new radiation detection method. The research purpose is the development of economical environmental radiation dosimeter. This system consists of Plastic/Inorganic scintillator and Si photo-diode based detector and counting based circuitry. So count rate(cps) can be convert to air exposure rate(R/hr). There are three major advantages in this system. First advantages is no high voltage power supply like GM counter. Second advantage is simple electronics. Simple electronics system can be achieved by Air-equivalent scintillation detector with Al filter for the same detection efficiency vs E curve. From former two advantages, we can know the most important advantages of the this system. Third advantage is economical system. The price of typical GM counter is about $1000. But the price of our system is below $100 because of plastic scintillator and simple electronics. The role of scintillation material is emitting scintillation which is the flash of light produced in certain materials when they absorb ionizing radiation. Plastic scintillator is organic scintillator which is kind of hydrocarbons. The special point are cheap price, large size production(∼ton), moderate light output, fast light emission(ns). And the role of Al filter is equalizing counting efficiency of air and scintillator for

  12. Bayesian modelling of the emission spectrum of the JET Li-BES system

    Kwak, Sehyun; Svensson, J.; Brix, M.; Ghim, Y. -c.; Contributors, JET

    2015-01-01

    A Bayesian model of the emission spectrum of the JET lithium beam has been developed to infer the intensity of the Li I (2p-2s) line radiation and associated uncertainties. The detected spectrum for each channel of the lithium beam emission spectroscopy (Li-BES) system is here modelled by a single Li line modified by an instrumental function, Bremsstrahlung background, instrumental offset, and interference filter curve. Both the instrumental function and the interference filter curve are mode...

  13. The annihilation spectrum of relatiVistic electron-positron plasma

    Aragonyan, F.A.; Atoyan, A.M.; Syunyaev, R.A.

    1980-01-01

    The annihilation spectrum of isotropically distributed monoenergetic electrons and positrons is obtained. The spectrum of the (e + e - ) plasma is analyzed in a large range of plasma temperatures. The comparison of transitions peratures. The comparison of transitions intensities of annihilation radiation and bremsstrahlung shows that for temperatures kT 2 (e + e - ) plasma is cooled mainly due to annihilation. The case of the fast positron annihilation on the rest electrons also considered. The possible astrophysical applications are discussed [ru

  14. Can the tinnitus spectrum identify tinnitus subgroups?

    Heijneman, Karin M.; de Kleine, Emile; Wiersinga-Post, Esther; van Dijk, Pim

    2013-01-01

    The tinnitus spectrum is a psycho-acoustic metric of tinnitus. Previous work found a tight relation between the spectrum and the tone audiogram. This suggests that the spectrum and the audiogram provide essentially the same information, and the added value of the spectrum is limited. In order to

  15. Spectrum Trading in India and 5G

    Tripathi, Purnendu; Prasad, Ramjee

    2013-01-01

    Currently radio spectrum is largely managed through Command and Control method. Public mobile services require spectrum below 3 GHz for providing cost effective services. The existing method has created artificial shortage of spectrum especially below 3 GHz. Spectrum trading is a new concept...

  16. Radiation protection

    Jain, Aman; Sharma, Shivam; Parasher, Abhishek

    2014-01-01

    Radiation dose measurement, field of radiobiology, is considered to be critical factor for optimizing radiation protection to the health care practitioners, patients and the public. This lead to equipment that has dose - area product meters permanently installed. In many countries and even institution, the range of equipment is vast and with the opportunity for radiation protection and dose recording varies considerably. Practitioners must move with the changed demands of radiation protection but in many cases without assistance of modern advancements in technology Keeping the three basic safety measures Time, Dose and Shielding we can say 'Optimum dose is safe dose' instead of 'No dose is safe dose'. The purpose enclosed within the title 'Radiation Protection'. The use of radiation is expanding widely everyday around the world and crossing boundaries of medical imaging, diagnostic and. The way to get the ''As low as reasonably achievable' is only achievable by using methodology of radiation protection and to bring the concern of general public and practitioners over the hazards of un-necessary radiation dose. Three basic principles of radiation protection are time, distance and shielding. By minimizing the exposure time increasing the distance and including the shielding we can reduce the optimum range of dose. The ability of shielding material to attenuate radiation is generally given as half value layer. This is the thickness of the material which will reduce the amount of radiation by 50%. Lab coat and gloves must be worn when handling radioactive material or when working in a labeled radiation work area. Safety glasses or other appropriate splash shields should be used when handling radioactive material. 1. Reached to low dose level to occupational workers, public as per prescribed dose limit. 2. By mean of ALARA principle we achieved the protection from radiation besides us using the radiation for our benefit

  17. Modification of genetic effects of gamma radiation by laser radiation

    Khotyljova, L.V.; Khokhlova, S.A.; Khokhlov, I.V.

    1988-01-01

    Full text: Mutants obtained by means of ionizing radiation and chemical mutagens often show low viability and productivity that makes their use in plant breeding difficult. Methods reducing the destructive mutagen action on important functions of plant organism and increasing quality and practical value of induced mutants would be interesting. We believe that one method for increasing efficiency of experimental mutagenesis in plants is the application of laser radiation as a modificator of genetic effects of ionizing radiation and chemical mutagens. Combined exposure of wheat seedlings to a gamma radiation dose of 2 kR and to laser radiation with the wave length of 632.8 nm (power density - 20 mVt/cm 2 , exposure - 30 min.) resulted in reducing the chromosomal aberration percentage from 30.5% in the gamma version to 16.3% in the combined treatment version. A radiosensibilizing effect was observed at additional exposure of gamma irradiated wheat seeds to laser light with the wave length of 441.6 nm where chromosomal aberration percentage increased from 22% in the gamma-irradiation version to 31% in the combined treatment version. By laser radiation it is also possible to normalize mitotic cell activity suppressed by gamma irradiation. Additional seedling irradiation with the light of helium-neon laser (632.8 nm) resulted in recovery of mitotic cell activity from 21% to 62% and increasing the average content of DNA per nucleus by 10%. The influence of only laser radiation on plant variability was also studied and it was shown that irradiation of wheat seeds and seedlings with pulsed and continuous laser light of visible spectrum resulted in phenotypically altered forms in M 2 . Their frequencies was dependent upon power density, dose and radiation wave length. Number of altered forms increased in going from long-wave to short-wave spectrum region. In comparing efficiency of different laser types of pulsed and continuous exposure (dose - 180 J/cm 2 ) 2% of altered

  18. Dynamic spectrum auction in wireless communication

    Chen, Yanjiao

    2015-01-01

    This brief explores current research on dynamic spectrum auctions, focusing on fundamental auction theory, characteristics of the spectrum market, spectrum auction architecture and possible auction mechanisms. The brief explains how dynamic spectrum auctions, which enable new users to gain spectrum access and existing spectrum owners to obtain financial benefits, can greatly improve spectrum efficiency by resolving the artificial spectrum shortage. It examines why operators and users face significant challenges due to specialty of the spectrum market and the related requirements imposed on the auction mechanism design. Concise and up-to-date, Dynamic Spectrum Auction in Wireless Communication is designed for researchers and professionals in computer science or electrical engineering. Students studying networking will also find this brief a valuable resource.

  19. About kinetics of paramagnetic radiation malformations in beryllium ceramics

    Polyakov, A.I.; Ryabinkin, Yu.A.; Zashkvara, O.V.; Bitenbaev, M.I.; Petukhov, Yu.V.

    1999-01-01

    This paper [1] specifies that γ-radiation of the beryllium-oxide-based ceramics results in development of paramagnetic radiation malformations emerging the ESR spectrum in form of doublet with the splitting rate of oestrasid Δ∼1.6 and g-factor of 2.008. This report presents evaluation outcomes of dependence of paramagnetic radiation malformations concentration in beryllium ceramics on gamma-radiation dose ( 60 Co) within the range of 0-100 Mrad. Total paramagnetic parameters of beryllium ceramics in the range 0-100 Mrad of gamma-radiation dose varied slightly, and were specified by the first type of paramagnetic radiation malformations

  20. Activities in biological radiation research at the AGF

    1984-01-01

    The AGF is working on a wide spectrum of biological radiation research, with the different scientific disciplines contributing different methodologies to long-term research projects. The following fields are studied: 1. Molecular and cellular modes of action of radiation. 2. Detection and characterisation of biological radiation damage, especially in humans. 3. Medical applications of radiation effects. 4. Concepts and methods of radiation protection. The studies will lead to suggestions for radiation protection and improved radiotherapy. They may also contribute to the development of environmental protection strategies. (orig./MG) [de

  1. Spectrum of PEX6 mutations in Zellweger syndrome spectrum patients

    Ebberink, Merel S.; Kofster, Janet; Wanders, Ronald J. A.; Waterham, Hans R.

    2010-01-01

    The autosomal recessive Zellweger syndrome spectrum (ZSS) disorders comprise a main subgroup of the peroxisome biogenesis disorders. The ZSS disorders can be caused by mutations in any of 12 different currently identified PEX genes resulting in severe, often lethal, multi-systemic disorders. Defects

  2. Atoms, Radiation, and Radiation Protection

    Turner, James E

    2007-01-01

    Atoms, Radiation, and Radiation Protection offers professionals and advanced students a comprehensive coverage of the major concepts that underlie the origins and transport of ionizing radiation in matter. Understanding atomic structure and the physical mechanisms of radiation interactions is the foundation on which much of the current practice of radiological health protection is based. The work covers the detection and measurement of radiation and the statistical interpretation of the data. The procedures that are used to protect man and the environment from the potential harmful effects of

  3. Radiation dosimetry and radiation biophysics

    Anon.

    1981-01-01

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with the design and measurement of physical parameters used in theory or to support biological experiments. The radiation biophysics program tests and uses the theoretical developments for experimental design, and provides information for further theoretical development through experiments on cellular systems

  4. Radiation dosimetry and radiation biophysics

    Anon.

    1979-01-01

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with design and measurement of those physical parameters used in the theory or to support biological experiments. The radiation biophysics program tests and makes use of the theoretical developments for experimental design. Also, this program provides information for further theoretical development through experiments on cellular systems

  5. Thermal-spectrum recriticality energetics

    Schwinkendorf, K.N.

    1993-12-01

    Large computer codes have been created in the past to predict the energy release in hypothetical core disruptive accidents (CDA), postulated to occur in liquid metal reactors (LMR). These codes, such as SIMMER, are highly specific to LMR designs. More recent attention has focused on thermal-spectrum criticality accidents, such as for fuel storage basins and waste tanks containing fissile material. This paper resents results from recent one-dimensional kinetics simulations, performed for a recriticality accident in a thermal spectrum. Reactivity insertion rates generally are smaller than in LMR CDAs, and the energetics generally are more benign. Parametric variation of input was performed, including reactivity insertion and initial temperature

  6. Clinical neurogenetics: autism spectrum disorders.

    Mehta, Sunil Q; Golshani, Peyman

    2013-11-01

    Autism spectrum disorders are neurodevelopmental disorders characterized by deficits in social interactions, communication, and repetitive or restricted interests. There is strong evidence that de novo or inherited genetic alterations play a critical role in causing Autism Spectrum Disorders, but non-genetic causes, such as in utero infections, may also play a role. Magnetic resonance imaging based and autopsy studies indicate that early rapid increase in brain size during infancy could underlie the deficits in a large subset of subjects. Clinical studies show benefits for both behavioral and pharmacological treatment strategies. Genotype-specific treatments have the potential for improving outcome in the future. Published by Elsevier Inc.

  7. Autism Spectrum Disorders in Iran

    Mohammad Reza MOHAMMADI; Maryam SALMANIAN; Shahin AKHONDZADEH

    2011-01-01

    How to Cite this Article: Mohammadi MR, Salmanian M, Akhondzadeh Sh. Autism Spectrum Disorders in Iran. Iranian Journal of Child Neurology2011;5(4):1-9.ObjectiveAutistic disorder, Asperger syndrome, and PDD-Not Otherwise Specified are subsets of autism spectrum disorders (ASDs), which are characterized by impairments in social communication and stereotyped behavior. This article reviews the prevalence, etiology, diagnosis, and treatment of ASDs in Iran.Materials & MethodsWe searched PubMe...

  8. Direct measurements of the spectrum of the near-millimeter cosmic background

    Richards, P.L.

    1980-01-01

    The spectrum of the cosmic background radiation peaks at 6 cm -1 and falls rapidly at higher frequencies. The experimental determination of this simple but important fact has had a long and troubled history. It remained in doubt long after the nature of the Rayleigh-Jeans region of the spectrum was firmly established. In this review the author describes the experimental difficulties which have plagued cosmic background measurements at and beyond the peak in the spectrum. A critical evaluation of the present status of the field is then given. (Auth.)

  9. Influence functionals and black body radiation

    Anglin, J. R.

    1993-01-01

    The Feynman-Vernon formalism is used to obtain a microscopic, quantum mechanical derivation of black body radiation, for a massless scalar field in 1+1 dimensions, weakly coupled to an environment of finite size. The model exhibits the absorption, thermal equilibrium, and emission properties of a canonical black body, but shows that the thermal radiation propagates outwards from the body, with the Planckian spectrum applying inside a wavefront region of finite thickness. The black body enviro...

  10. Radiation injury

    Hubner, K.F.

    1988-01-01

    Radiation accidents and incidents continue to be of great interest and concern to the public. Issues such as the threat of nuclear war, the Chernobyl reactor accident, or reports of sporadic incidences of accidental radiation exposure keep this interest up and maintain a high level of fear among the public. In this climate of real concern and radiation phobia, physicians should not only be prepared to answer questions about acute or late effects of ionizing radiation, but also be able to participate in the initial assessment and management of individuals who have been exposed to ionizing radiation or contaminated with radioactive material. Some of the key facts about radiation injury and its medical treatment are discussed by the author

  11. Cosmic radiation

    Capdevielle, J N

    1984-01-01

    First, the different instruments and techniques of cosmic particle detection are presented. Then the passage of the cosmic particles through the atmosphere is studied: electrons, photons, muons. The collective behavior of the different categories is also studied, the electromagnetic cascade is distinguished from the hadron cascade. Through the principal physical properties of the radiation and the medium, the ''mean'' aspects of the radiation are then successively dealt with out of the atmosphere, at different altitudes until the sea level, then at great depths. A chapter is devoted to cosmic radiation of more than 10,000 GeV, studied separately. Then solar radiation in universe is studied through their propagation in solar system and their origin. At last, the cosmic radiation effects are studied in environment (cosmic biophysics) and some applications of cosmic radiation are presented.

  12. Radiation carcinogenesis

    Fry, R.J.M.

    1976-01-01

    The risk of iatrogenic tumors with radiation therapy is so outweighed by the benefit of cure that estimates of risk have not been considered necessary. However, with the introduction of chemotherapy, combined therapy, and particle radiation therapy, the comparative risks should be examined. In the case of radiation, total dose, fractionation, dose rate, dose distribution, and radiation quality should be considered in the estimation of risk. The biological factors that must be considered include incidence of tumors, latent period, degree of malignancy, and multiplicity of tumors. The risk of radiation induction of tumors is influenced by the genotype, sex, and age of the patient, the tissues that will be exposed, and previous therapy. With chemotherapy the number of cells at risk is usually markedly higher than with radiation therapy. Clearly the problem of the estimation of comparative risks is complex. This paper presents the current views on the comparative risks and the importance of the various factors that influence the estimation of risk

  13. Non-strictly black body spectrum from the tunnelling mechanism

    Corda, Christian

    2013-01-01

    The tunnelling mechanism is widely used to explain Hawking radiation. However, in many cases the analysis used to obtain the Hawking temperature only involves comparing the emission probability for an outgoing particle with the Boltzmann factor. Banerjee and Majhi improved this approach by explicitly finding a black body spectrum associated with black holes. Their result, obtained using a reformulation of the tunnelling mechanism, is in contrast to that of Parikh and Wilczek, who found an emission probability that is compatible with a non-strictly thermal spectrum. Using the recently identified effective state for a black hole, we solve this contradiction via a slight modification of the analysis by Banerjee and Majhi. The final result is a non-strictly black body spectrum from the tunnelling mechanism. We also show that for an effective temperature, we can express the corresponding effective metric using Hawking’s periodicity arguments. Potential important implications for the black hole information puzzle are discussed. -- Highlights: •We review an important result by Banerjee and Majhi on the tunnelling mechanism in the framework of Hawking radiation. •This result is in contrast to another result reported by Parikh and Wilczek. •We introduce the effective state of a black hole. •We explain the contrast via a slight modification of the analysis by Banerjee and Majhi. •We discuss potential important implications for the black hole information puzzle

  14. Gamma ray energy spectrum of a buried radioactive source

    Massey, N B

    1957-07-01

    Because of current attempts to utilize airborne gamma-ray scintillation spectrometers as a means of detecting and identifying buried radioactive mineral deposits, it has become important to study the effects of multiple scattering on the gamma-ray energy spectrum of a source buried in a semi-infinite medium. A series of ten experiments was made. First a scintillation detector was located in air at a fixed distance above a 250 microcurie cobalt-60 source suspended in a large tank. The level of water was raised from 25 cm below the source to 50 cm above, and the gamma-ray energy spectrum was observed. It was found that the high energy portion of the cobalt-60 spectrum remained identifiable even when the source was submerged more than five half-lengths. Further, the ratio of the counting rate of the total incident gamma radiation to the counting rate of the primary 1.33 MeV radiation was found to be very nearly linearly proportional to the depth of water cover. This leads to an empirical method for determining the depth of burial of a cobalt-60 point source. (author)

  15. [The Effect of Observation Geometry on Polarized Skylight Spectrum].

    Zhang, Ren-bin; Wang, Ling-mei; Gao, Jun; Wang, Chi

    2015-03-01

    Study on polarized skylight spectral characters while observation geometry changing in different solar zenith angles (SZA), viewing zenith angles (VZA) or relative azimuth angles (RAA). Simulation calculation of cloudless daylight polarimetric spectrum is realized based on the solver, vector discrete ordinate method, of radiative transfer equation. In the Sun's principal and perpendicular plane, the spectral irradiance data, varying at wavelengths in the range between 0.4 and 3 μm, are calculated to extend the atmospheric polarization spectral information under the conditions: the MODTRAN solar reference spectrur is the only illuminant source; the main influencing factors of polarized radiative transfer include underlying surface albedo, aerosol layers and components, and the absorption of trace gases. Simulation analysis results: (1) While the relative azimuth angle is zero, the magnitude of spectrum U/I is lower than 10(-7) and V/I is negligible, the degree of polarization and the spectrum Q/I are shaped like the letter V or mirror-writing U. (2) In twilight, when the Sun is not in FOV of the detector, the polarization of the daytime sky has two maximum near 0.51 and 2.75 μm, and a minimum near 1.5 μm. For arbitrary observation geometry, the spectral signal of V/I may be ignored. According to observation geometry, choosing different spectral bands or polarized signal will be propitious to targets detection.

  16. Action Spectrum of Photoinhibition in the Diatom Phaeodactylum tricornutum.

    Havurinne, Vesa; Tyystjärvi, Esa

    2017-12-01

    Light-dependent electron transfer is necessary for photosynthesis, but light also damages PSII. Light-induced damage to PSII is called photoinhibition, and the damaging reactions of photoinhibition are still under debate. Diatoms possess an exotic combination of light-harvesting pigments, Chls a/c and fucoxanthin, making them an interesting platform for studying the photoreceptors of photoinhibition. We first confirmed the direct proportionality of photoinhibition to the photon flux density of incident light in the diatom Phaeodactylum tricornutum. Phaeodactylum is known for its efficient non-photochemical quenching, and the effect of this photoprotective mechanism on photoinhibition was tested. Photoinhibition proceeded essentially at the same rate in blue-light-grown Phaeodactylum cells that are capable of non-photochemical quenching and in red-light-grown, non-photochemical quenching-deficient cells. To obtain more insight into how the pigment composition of diatoms affects photoinhibition, we measured the action spectrum of photoinhibition in Phaeodactylum. In visible light, the action spectrum resembled the absorption spectrum of Phaeodactylum, and UV radiation caused much more photoinhibition than visible light. Comparison of the action spectrum of photoinhibition with the absorption spectrum and the excitation spectrum of 77 K PSII fluorescence emission confirmed that photosynthetic pigments are involved in photoinhibition, but the photoinhibitory efficiency of red light is weak, suggesting that the role of light-harvesting pigments as light receptors of photoinhibition is secondary. Finally, we compared photoinhibition in Phaeodactylum with that in other photosynthetic organisms, and our data indicate that the PSII reaction centers of Phaeodactylum are not particularly well protected against the primary damage of photoinhibition. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights

  17. Hawking radiation

    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.

  18. Radiation meter

    Burgess, P H

    1990-05-30

    Measuring means comprising first and second silicon PIN diode detectors both being covered with a thin layer of conducting material and the second detector being additionally covered with a relatively thick layer of material, the thickness being chosen such that beta radiation dose rate can be measured in beta radiation fields of high or medium energy, and in the presence of X and gamma radiation. (author). 2 figs.

  19. Radiation regulation

    Braithwaite, J.; Grabosky, P.

    1985-01-01

    The five main areas of radiation regulation considered are radiation exposure in the mining of uranium and other minerals, exposure in the use of uranium in nuclear reactors, risks in the transport of radioactive materials and hazards associated with the disposal of used materials. In Australia these problems are regulated by mines departments, the Australian Atomic Energy Commission and radiation control branches in state health departments. Each of these instutional areas of regulation is examined

  20. Radiation chemistry

    None

    1973-07-01

    Research progress is reported on radiation chemistry of heavy elements that includes the following topics: radiation chemistry of plutonium in nitric acid solutions (spectrophotometric analysis and gamma radiolysis of Pu(IV) and Pu(VI) in nitric acid solution); EPR studies of intermediates formed in radiolytic reactions with aqueous medium; two-phase radiolysis and its effect on the distribution coefficient of plutonium; and radiation chemistry of nitric acid. (DHM)

  1. Oculoauriculovertebral spectrum and cerebral anomalies

    Schrander-Stumpel, C. T.; de Die-Smulders, C. E.; Hennekam, R. C.; Fryns, J. P.; Bouckaert, P. X.; Brouwer, O. F.; da Costa, J. J.; Lommen, E. J.; Maaswinkel-Mooy, P. D.

    1992-01-01

    We report on three Dutch children with a clinical diagnosis of oculoauriculovertebral spectrum (OAVS) and hydrocephalus. The clinical features are compared to 15 published cases of OAVS and hydrocephalus. Several other cerebral abnormalities were present in the whole group. About half of the cases

  2. Deafness and Autistic Spectrum Disorders

    Vernon, McCay; Rhodes, Anthony

    2009-01-01

    An orientation to autistic spectrum disorders (ASD), also known as autism, is provided, and the specific syndrome of autism and deafness is addressed. The two conditions have in common a major problem: communication. Case histories are provided, the development of treatment for autism is discussed, and the separate disorders that make up ASD are…

  3. Neurofeedback in Autism Spectrum Disorders

    Holtmann, Martin; Steiner, Sabina; Hohmann, Sarah; Poustka, Luise; Banaschewski, Tobias; Bolte, Sven

    2011-01-01

    Aim: To review current studies on the effectiveness of neurofeedback as a method of treatment of the core symptoms of autism spectrum disorders (ASD). Method: Studies were selected based on searches in PubMed, Ovid MEDLINE, EMBASE, ERIC, and CINAHL using combinations of the following keywords: "Neurofeedback" OR "EEG Biofeedback" OR "Neurotherapy"…

  4. Spectrum of pediatric neuromyelitis optica.

    Lotze, Timothy E; Northrop, Jennifer L; Hutton, George J; Ross, Benjamin; Schiffman, Jade S; Hunter, Jill V

    2008-11-01

    Our goal was to describe the spectrum of clinical phenotypes, laboratory and imaging features, and treatment in pediatric patients with neuromyelitis optica. The study consisted of a retrospective chart review of patients followed in a pediatric multiple sclerosis center with a diagnosis of neuromyelitis optica spectrum disorder. Nine patients with neuromyelitis optica spectrum disorders were included, all of whom were female. There were 4 black children, 2 Latin American children, 2 white children, and 1 child of mixed Latin American/white heritage. Median age at initial attack was 14 years (range: 1.9-16 years). Median disease duration was 4 years (range: 0.6-9 years). Tests for neuromyelitis optica immunoglobulin G were positive for 7 patients. Eight patients had transverse myelitis and optic neuritis, and 1 patient had longitudinally extensive transverse myelitis without optic neuritis but had a positive neuromyelitis optica immunoglobulin G antibody titer. Cerebral involvement on MRI was found in all subjects, 5 of whom were symptomatic with encephalopathy, seizures, hemiparesis, aphasia, vomiting, or hiccups. Immunosuppressive therapy reduced attack frequency and progression of disability. Pediatric neuromyelitis optica has a diverse clinical presentation and may be difficult to distinguish from multiple sclerosis in the early stages of the disease. The recognition of the broad spectrum of this disease to include signs and symptoms of brain involvement is aided by the availability of a serum biomarker: neuromyelitis optica immunoglobulin G. Early diagnosis and immunosuppresive treatment may help to slow the accumulation of severe disability.

  5. [Autism spectrum disorders in adults

    Kan, C.C.; Buitelaar, J.K.; Gaag, R.J. van der

    2008-01-01

    Early infantile autism' as defined by Kanner has grown into a spectrum of autistic disorders. The recognition of Asperger's disorder and of pervasive developmental disorder not otherwise specified (PDD-NOS), has led to increased demand for appropriate diagnostic assessment of autism in adults. The

  6. New criteria to identify spectrum

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Fr. Bajers Vej 7G, DK-9220 Aalborg Ø, Denmark. ∗. Institute of ... one defines the corresponding parts of the spectrum to be those of the restricted operators. ... The relation comes from the representation of the time evolution operator e. −itH as.

  7. Autism Spectrum Disorders and Epigenetics

    Grafodatskaya, Daria; Chung, Brian; Szatmari, Peter; Weksberg, Rosanna

    2010-01-01

    Objective: Current research suggests that the causes of autism spectrum disorders (ASD) are multifactorial and include both genetic and environmental factors. Several lines of evidence suggest that epigenetics also plays an important role in ASD etiology and that it might, in fact, integrate genetic and environmental influences to dysregulate…

  8. The Organizational Communication Consulting Spectrum.

    Tubbs, Stewart L.

    Surveys of businesses and business managers indicate that developing communication skills within organizations is a priority. Communication consulting exists over a wide spectrum of activities that include guest speaking, conducting workshops, and conducting management training programs. These three processes can include a "canned program" that…

  9. Radiation protection

    1989-01-01

    A NRPB leaflet in the 'At-a-Glance' series explains in a simple but scientifically accurate way what radiation is, the biological effects and the relative sensitivity of different parts of the human body. The leaflet then discusses radiation protection principles, radiation protection in the UK and finally the effectiveness of this radiation protection as judged by a breakdown of the total dose received by an average person in the UK, a heavy consumer of Cumbrian seafood, an average nuclear industry worker and an average person in Cornwall. (UK)

  10. Radiation medicine

    1991-01-01

    This booklet has been produced by UKAEA and the Marie Curie Memorial Foundation to give some basic information about what radiation is and how it is used in day to day diagnosis and treatment. It will be of interest to people undergoing treatment, their relatives and friends, and anyone who wants to know more about this important area. After a brief historical introduction the booklet explains what radiation is, the natural and man-made sources of radiation, how it is produced and how X-rays are used in medical diagnosis and treatment. The radiation protection measures taken and safety standards followed are mentioned. (author)

  11. GRAVITATIONAL RADIATION

    Metin SALTIK

    1996-03-01

    Full Text Available According to classical electromagnetic theory, an accelerated charge or system of charges radiates electromagnetic waves. In a radio transmitter antenna charges are accelerated along the antenna and release electromagnetic waves, which is radiated at the velocity of light in the surrounding medium. All of the radio transmitters work on this principle today. In this study an analogy is established between the principles by which accelerated charge systems markes radiation and the accelerated mass system, and the systems cousing gravitational radiation are investigated.

  12. Cosmic microwave background radiation anisotropies in brane worlds.

    Koyama, Kazuya

    2003-11-28

    We propose a new formulation to calculate the cosmic microwave background (CMB) spectrum in the Randall-Sundrum two-brane model based on recent progress in solving the bulk geometry using a low energy approximation. The evolution of the anisotropic stress imprinted on the brane by the 5D Weyl tensor is calculated. An impact of the dark radiation perturbation on the CMB spectrum is investigated in a simple model assuming an initially scale-invariant adiabatic perturbation. The dark radiation perturbation induces isocurvature perturbations, but the resultant spectrum can be quite different from the prediction of simple mixtures of adiabatic and isocurvature perturbations due to Weyl anisotropic stress.

  13. Generalized eigenvalue based spectrum sensing

    Shakir, Muhammad

    2012-01-01

    Spectrum sensing is one of the fundamental components in cognitive radio networks. In this chapter, a generalized spectrum sensing framework which is referred to as Generalized Mean Detector (GMD) has been introduced. In this context, we generalize the detectors based on the eigenvalues of the received signal covariance matrix and transform the eigenvalue based spectrum sensing detectors namely: (i) the Eigenvalue Ratio Detector (ERD) and two newly proposed detectors which are referred to as (ii) the GEometric Mean Detector (GEMD) and (iii) the ARithmetic Mean Detector (ARMD) into an unified framework of generalize spectrum sensing. The foundation of the proposed framework is based on the calculation of exact analytical moments of the random variables of the decision threshold of the respective detectors. The decision threshold has been calculated in a closed form which is based on the approximation of Cumulative Distribution Functions (CDFs) of the respective test statistics. In this context, we exchange the analytical moments of the two random variables of the respective test statistics with the moments of the Gaussian (or Gamma) distribution function. The performance of the eigenvalue based detectors is compared with the several traditional detectors including the energy detector (ED) to validate the importance of the eigenvalue based detectors and the performance of the GEMD and the ARMD particularly in realistic wireless cognitive radio network. Analytical and simulation results show that the newly proposed detectors yields considerable performance advantage in realistic spectrum sensing scenarios. Moreover, the presented results based on proposed approximation approaches are in perfect agreement with the empirical results. © 2012 Springer Science+Business Media Dordrecht.

  14. Radiation and radiation protection; Strahlung und Strahlenschutz

    Bartholomaeus, Melanie (comp.)

    2017-04-15

    The publication of the Bundesamt fuer Strahlenschutz covers the following issues: (i) Human beings in natural and artificial radiation fields; (ii) ionizing radiation: radioactivity and radiation, radiation exposure and doses; measurement of ionizing radiation, natural radiation sources, artificial radiation sources, ionizing radiation effects on human beings, applied radiation protection, radiation exposure of the German population, radiation doses in comparison; (iii) non-ionizing radiation; low-frequency electric and magnetic fields, high-frequency electromagnetic fields, optical radiation; (iiii) glossary, (iv) units and conversion.

  15. Understanding the Planck blackbody spectrum and Landau diamagnetism within classical electromagnetism

    Boyer, Timothy H

    2016-01-01

    Electromagnetism is a relativistic theory, and one must exercise care in coupling this theory with nonrelativistic classical mechanics and with nonrelativistic classical statistical mechanics. Indeed historically, both the blackbody radiation spectrum and diamagnetism within classical theory have been misunderstood because of two crucial failures: (1) the neglect of classical electromagnetic zero-point radiation, and (2) the use of erroneous combinations of nonrelativistic mechanics with relativistic electrodynamics. Here we review the treatment of classical blackbody radiation, and show that the presence of Lorentz-invariant classical electromagnetic zero-point radiation can explain both the Planck blackbody spectrum and Landau diamagnetism at thermal equilibrium within classical electromagnetic theory. The analysis requires that relativistic electromagnetism is joined appropriately with simple nonrelativistic mechanical systems which can be regarded as the zero-velocity limits of relativistic systems, and that nonrelativistic classical statistical mechanics is applied only in the low-frequency limit when zero-point energy makes no contribution. (paper)

  16. A neutron spectrum unfolding code based on iterative procedures

    Ortiz R, J. M.; Vega C, H. R.

    2012-10-01

    In this work, the version 3.0 of the neutron spectrum unfolding code called Neutron Spectrometry and Dosimetry from Universidad Autonoma de Zacatecas (NSDUAZ), is presented. This code was designed in a graphical interface under the LabVIEW programming environment and it is based on the iterative SPUNIT iterative algorithm, using as entrance data, only the rate counts obtained with 7 Bonner spheres based on a 6 Lil(Eu) neutron detector. The main features of the code are: it is intuitive and friendly to the user; it has a programming routine which automatically selects the initial guess spectrum by using a set of neutron spectra compiled by the International Atomic Energy Agency. Besides the neutron spectrum, this code calculates the total flux, the mean energy, H(10), h(10), 15 dosimetric quantities for radiation protection porpoises and 7 survey meter responses, in four energy grids, based on the International Atomic Energy Agency compilation. This code generates a full report in html format with all relevant information. In this work, the neutron spectrum of a 241 AmBe neutron source on air, located at 150 cm from detector, is unfolded. (Author)

  17. Joint opportunistic beam and spectrum selection schemes for spectrum sharing systems with limited feedback

    Sayed, Mostafa M.; Abdallah, Mohamed M.; Qaraqe, Khalid A.; Tourki, Kamel; Alouini, Mohamed-Slim

    2014-01-01

    Spectrum sharing systems have been introduced to alleviate the problem of spectrum scarcity by allowing an unlicensed secondary user (SU) to share the spectrum with a licensed primary user (PU) under acceptable interference levels to the primary

  18. Radiation myelopathy

    Berlit, P.

    1987-01-01

    After a review of the world literature, the case histories of 43 patients with radiation myelopathy are analyzed. In 1 patient there was a radiation injury of the medulla oblongata, in 2, cervical, in 28, thoracic, and in 12, lumbosacral. In the medulla oblongata lesion an alternans syndrome resulted. The patients with cervical and thoracic radiation myelopathies presented with a Brown-Sequard syndrome, a spinalis anterior syndrome or a transversal syndrome with pyramidal and spinothalamic tract involvement as the most prominent signs. For this group the term 'pyramidal-spinothalamic radiation myelopathy' is proposed. In lumbosacral radiation lesions a pure anterior horn syndrome may lead to spinothalamic tract involvement and the development of a cauda conus syndrome. The clinical presentation of these cases suggests that the location of the radiation lesion is most likely the region of the conus medullaris. The most frequent initial symptom was dysesthesia; the patients complained of burning pain or a feeling of coldness. Usually the neurological deficits were progressive, in pyramidal-spinothalamic radiation myelopathy over 12 months in average, in lumbosacral radiation lesions up to 10 years. The latent period between the finish of radiation therapy and the first neurological signs was 8 months (median) in cervical and thoracic myelopathy and 33 months in lumbosacral lesions. For the entire group of 43 patients there was an inverse relationship between the radiation dose (ret) and the latent period. A positive relation could be demonstrated between the age of patients at the time of radiation therapy and the latent period. Patients simultaneously receiving cytostatic drugs presented after a longer latent period than the remaining group. (orig./MG)

  19. Concepts of radiation protection

    2013-01-01

    This seventh chapter presents the concepts and principles of safety and radiation protection, emergency situations; NORM and TENORM; radiation protection care; radiation protection plan; activities of the radiation protection service; practical rules of radiation protection and the radiation symbol

  20. Radiation exposure and radiation protection

    Heuck, F.; Scherer, E.

    1985-01-01

    The present volume is devoted to the radiation hazards and the protective measures which can be taken. It describes the current state of knowledge on the changes which exposure to ionizing rays and other forms of physical energy can induce in organs and tissues, in the functional units and systems of the organism. Special attention is paid to general cellular radiation biology and radiation pathology and to general questions of the biological effects of densely ionizing particle radiation, in order to achieve a better all-round understanding of the effects of radiation on the living organism. Aside from the overviews dealing with the effects of radiation on the abdominal organs, urinary tract, lungs, cerebral and nervous tissue, bones, and skin, the discussion continues with the lymphatic system, the bone marrow as a bloodforming organ, and the various phases of reaction in the reproductive organs, including damage and subsequent regeneration. A special section deals with environmental radiation hazards, including exposure to natural radiation and the dangers of working with radioactive substances, and examines radiation catastrophes from the medical point of view. Not only reactor accidents are covered, but also nuclear explosions, with exhaustive discussion of possible damage and treatment. The state of knowledge on chemical protection against radiation is reviewed in detail. Finally, there is thorough treatment of the mechanism of the substances used for protection against radiation damage in man and of experience concerning this subject to date. In the final section of the book the problems of combined radiotherapy are discussed. The improvement in the efficacy of tumor radiotherapy by means of heavy particles is elucidated, and the significance of the efficacy of tumor therapy using electron-affinitive substances is explained. There is also discussion of the simultaneous use of radiation and pharmaceuticals in the treatment of tumors. (orig./MG) [de

  1. ROSY - Rossendorf synchrotron radiation source

    Einfeld, D.; Matz, W.

    1993-11-01

    The electron energy of the storage ring will be 3 GeV and the emitted synchrotron radiation is in the hard X-ray region with a critical energy of the spectrum of E c =8,4 keV (λ c =0,14 nm). With a natural emittance of 28 π nm rad ROSY emits high brilliance radiation. Besides the radiation from bending magnets there will be the possibility for using radiation from wigglers and undulators. For the insertion devices 8 places are foreseen four of which are located in non-dispersion-free regions. The storage ring is of fourfold symmetry, has a circumference of 148 m and is designed in a modified FODO structure. An upgrade of ROSY with superconducting bending magnets in order to shift the spectrum to higher energy can easily be done. Part I contains the scientific case and a description of the planned use of the beam lines. Part II describes the design of the storage ring and its components in more detail. (orig.) [de

  2. Electromagnetic radiation of protons in edge fields of synchrotron dipole magnets

    Smolyakov, N.V.

    1986-01-01

    Effect of the edge shape of magnetic field of a dipole on the short-wave part of electromagnetic radiation spectrum of a proton beam is investigated. In some cases short-wave photons are shown to be shaped in the ranges of largest edge curvature of the magnetic field. Universality of edge radiation spectrum is proved. Spectral characteristics of proton edge radiation in a superconducting magnetic dipole of the storage-accelerator complex are obtained

  3. Spectra processing at tooth enamel dosimetry: Analytical description of EPR spectrum at different microwave power

    Tieliewuhan, E.; Ivannikov, A.; Zhumadilov, K.; Nalapko, M.; Tikunov, D.; Skvortsov, V.; Stepanenko, V.; Toyoda, S.; Tanaka, K.; Endo, S.; Hoshi, M.

    2006-01-01

    Variation of the electron paramagnetic resonance (EPR) spectrum of the human tooth enamel recorded at different microwave power is investigated. The analytical models describing the native and the radiation-induced signals in the enamel are proposed, which fit the experimental spectra in wide range of microwave power. These models are designed to use for processing the spectra of irradiated enamel at determination of the absorbed dose from the intensity of the radiation-induced signal

  4. Updated neutron spectrum characterization of SNL baseline reactor environments

    Griffin, P.J.; Kelly, J.G.; Vehar, D.W.

    1994-04-01

    This document provides SAND-II and MANIPULATE output listings from calculations used to derive the new spectrum-averaged integral parameters that were reported in volume 1. When used in conjunction with volume 1, this document provides an audit trail for the neutron radiation field characterization and supports current quality assurance initiatives. This document provides detailed information on the neutron spectrum characteristics of the primary Sandia National Laboratories' (SNL) reactor environments. The information in this volume is not intended for the casual user of the SNL reactor facilities. This detailed characterization of the neutron and gamma environments at the Sandia Pulsed Reactor (SPR) and the Annular Core Research Reactor (ACRR) is provided to aid the users who wish to convert the information given in the Radiation Metrology Laboratory (RML) dosimetry reports into other (non-silicon) measures of neutron damage. The spectra provided in these appendices can be used as a source term for Monte Carlo radiation transport calculations to study the impact of experimenter's test package on the neutron environment

  5. Background radiation

    Arnott, D.

    1985-01-01

    The effects of background radiation, whether natural or caused by man's activities, are discussed. The known biological effects of radiation in causing cancers or genetic mutations are explained. The statement that there is a threshold below which there is no risk is examined critically. (U.K.)

  6. Ionizing radiations

    Anon.

    1999-01-01

    This is an update about the radiological monitoring in base nuclear installations. A departmental order of the 23. march 1999 (J.O.28. april, p.6309) determines the enabling rules by the Office of Protection against Ionizing Radiations of person having at one's disposal the results with names of individual exposure of workers put through ionizing radiations. (N.C.)

  7. Radiation hematology

    Zherbin, E.A.; Chukhlovin, A.B.

    1989-01-01

    State-of-the-Art ofl radiation hematology and review of the problems now facing this brauch of radiobiology and nuclear medicine are presented. Distortion of division and maturation of hemopoiesis parent cells is considered as main factor of radiopathology for hematopoetic system. Problems of radiation injury and functional variation of hematopoetic microenvironment cell populations are discussed. 176 figs.; 23 figs.; 18 tabs

  8. Radiation oncology

    Anon.

    1977-01-01

    The Radiation Oncology Division has had as its main objectives both to operate an academic training program and to carry out research on radiation therapy of cancer. Since fiscal year 1975, following a directive from ERDA, increased effort has been given to research. The research activities have been complemented by the training program, which has been oriented toward producing radiation oncologists, giving physicians short-term experience in radiation oncology, and teaching medical students about clinical cancer and its radiation therapy. The purpose of the research effort is to improve present modalities of radiation therapy of cancer. As in previous years, the Division has operated as the Radiation Oncology Program of the Department of Radiological Sciences of the University of Puerto Rico School of Medicine. It has provided radiation oncology support to patients at the University Hospital and to academic programs of the University of Puerto Rico Medical Sciences Campus. The patients, in turn, have provided the clinical basis for the educational and research projects of the Division. Funding has been primarily from PRNC (approx. 40%) and from National Cancer Institute grants channeled through the School of Medicine (approx. 60%). Special inter-institutional relationships with the San Juan Veterans Administration Hospital and the Metropolitan Hospital in San Juan have permitted inclusion of patients from these institutions in the Division's research projects. Medical physics and radiotherapy consultations have been provided to the Radiotherapy Department of the VA Hospital

  9. Synchrotron radiation

    Nave, C.; Quinn, P.; Blake, R.J.

    1988-01-01

    The paper on Synchrotron Radiation contains the appendix to the Daresbury Annual Report 1987/88. The appendix is mainly devoted to the scientific progress reports on the work at the Synchrotron Radiation Source in 1987/8. The parameters of the Experimental Stations and the index to the Scientific Reports are also included in the appendix. (U.K.)

  10. Radiation Protection

    Loos, M.

    2002-01-01

    Major achievements of SCK-CEN's Radiation Protection Department in 2001 are described. The main areas for R and D of the department are enviromnental remediation, emergency planning, radiation protection research, low-level radioactvity measurements, safeguards and physics measurements, decision strategy research and policy support and social sciences in nuclear research. Main achievements for 2001 in these areas are reported

  11. Ionizing radiation

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

    1975-01-01

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

  12. Nature of the Background Ultraviolet Radiation Field at High Redshifts

    tribpo

    J. Astrophys. Astr. (2000) 21, 19-27 .... to know the shape of the ionizing radiation to determine the ionization parameter from the C II to C IV ratio. ... different shapes of the background radiation spectrum as explained in the text. The solid lines.

  13. Ionizing radiation sensitivity of DNA polymerase lambda-deficient cells.

    Vermeulen, C.; Bertocci, B.; Begg, A.C.; Vens, C.

    2007-01-01

    Ionizing radiation induces a diverse spectrum of DNA lesions, including strand breaks and oxidized bases. In mammalian cells, ionizing radiation-induced lesions are targets of non-homologous end joining, homologous recombination, and base excision repair. In vitro assays show a potential involvement

  14. Modelling the TSZ power spectrum

    Bhattacharya, Suman [Los Alamos National Laboratory; Shaw, Laurie D [YALE; Nagai, Daisuke [YALE

    2010-01-01

    The structure formation in university is a hierarchical process. As universe evolves, tiny density fluctuations that existed in the early universe grows under gravitational instability to form massive large scale structures. The galaxy clusters are the massive viralized objects that forms by accreting smaller clumps of mass until they collapse under their self-gravity. As such galaxy clusters are the youngest objects in the universe which makes their abundance as a function of mass and redshift, very sensitive to dark energy. Galaxy clusters can be detected by measuring the richness in optical waveband, by measuring the X-ray flux, and in the microwave sky using Sunyaev-Zel'dovich (SZ) effect. The Sunyaev-Zel'dovich (SZ) effect has long been recognized as a powerful tool for detecting clusters and probing the physics of the intra-cluster medium. Ongoing and future experiments like Atacama Cosmology Telescope, the South Pole Telescope and Planck survey are currently surveying the microwave sky to develop large catalogs of galaxy clusters that are uniformly selected by the SZ flux. However one major systematic uncertainties that cluster abundance is prone to is the connection between the cluster mass and the SZ flux. As shown by several simulation studies, the scatter and bias in the SZ flux-mass relation can be a potential source of systematic error to using clusters as a cosmology probe. In this study they take a semi-analytic approach for modeling the intra-cluster medium in order to predict the tSZ power spectrum. The advantage of this approach is, being analytic, one can vary the parameters describing gas physics and cosmology simultaneously. The model can be calibrated against X-ray observations of massive, low-z clusters, and using the SZ power spectrum which is sourced by high-z lower mass galaxy groups. This approach allows us to include the uncertainty in gas physics, as dictated by the current observational uncertainties, while measuring the

  15. EMISSION SPECTRUM OF HELIUM-LIKE IONS IN PHOTOIONIZED PLASMAS

    Wang, Feilu; Salzmann, David; Zhao, Gang; Takabe, Hideaki

    2012-01-01

    The aim of the present paper is to investigate the influence of inner-shell photoionization and photoexcitation on He α and its satellite's spectra in photoionized plasmas. An analysis is carried out on the relative importance of the various atomic processes in photoionized plasmas as a function of the electron temperature and irradiation conditions. In particular, we investigate the influence of K-shell photoionization of Li-like ions on the He α spectrum and of Be-like ions on the He α satellites. It is found that in photoionized plasmas these inner-shell processes contribute significantly under low radiation temperature and/or intensity, when Li- and Be-like ions are highly abundant but highly ionized H-like ions are rare. A short discussion is presented about the parameter space in which the excited 1s2p state has statistical or non-statistical distributions, and how such distributions affect the emission spectrum.

  16. Decay energy of 55Fe from its inner Bremsstrahlung spectrum

    Keshava, S.L.; Gopala, K.; Venkataramaiah, P.

    2001-01-01

    Several measurements of decay energy using the inner Bremsstrahlung spectrum (IB) due to radiative electron capture in 55 Fe has been made. But the results are not uniform. Hence another attempt has been made at the same. Experimental data was obtained with a 4.445 cm dia x 5.08 cm thick NaI (Tl) detector. It was subjected to suitable statistical treatment and various corrections using Liden and Starfelt procedure. The corrected spectrum agrees well with the Glauber and Martin theory for l s electron capture beyond 100 keV. From the Jauch plot, the decay energy of 232.36±0.64 keV was obtained. (author)

  17. Radiation of Electron in the Field of Plane Light Wave

    Zelinsky, A.; Drebot, I.V.; Grigorev, Yu.N.; Zvonareva, O.D.; Tatchyn, R.

    2006-01-01

    Results of integration of a Lorentz equation for a relativistic electron moving in the field of running, plane, linear polarized electromagnetic wave are presented in the paper. It is shown that electron velocities in the field of the wave are almost periodic functions of time. For calculations of angular spectrum of electron radiation intensity expansion of the electromagnetic field in a wave zone into generalized Fourier series was used. Expressions for the radiation intensity spectrum are presented in the paper. Derived results are illustrated for electron and laser beam parameters of NSC KIPT X-ray generator NESTOR. It is shown that for low intensity of the interacting electromagnetic wave the results of energy and angular spectrum calculations in the frame of classical electrodynamics completely coincide with calculation results produced using quantum electrodynamics. Simultaneously, derived expressions give possibilities to investigate dependence of energy and angular Compton radiation spectrum on phase of interaction and the interacting wave intensity

  18. Radiation exposure

    Dalton, L.K.

    1991-01-01

    The book gives accounts of some social and environmental impacts of the developing radiation industries, including the experiences of affected communities and individuals. Its structure is based on a division which has been made between nuclear and non-nuclear radiation sources, because they create distinctly different problems for environmental protection and so for public health policy. The emissions from electronic and electrical installations - the non-nuclear radiations - are dealt with in Part I. Emissions from radioactive substances - the nuclear radiations - are dealt with in Part II. Part III is for readers who want more detailed information about scientific basis of radiation-related biological changes and their associated health effects. 75 refs., 9 tabs., 7 figs., ills

  19. Radiation carcinogenesis

    Adams, G.E.

    1987-01-01

    In this contribution about carcinogenesis induced by ionizing radiation some radiation dose-response relationships are discussed. Curves are shown of the relation between cell survival and resp. low and high LET radiation. The difference between both curves can be ascribed to endogenous repair mechanisms in the cell. The relation between single-gen mutation frequency and the surviving fractions of irradiated cells indicates that these repairing mechanisms are not error free. Some examples of reverse dose-response relationships are presented in which decreasing values of dose-rate (LET) correspond with increasing radiation induced cell transformation. Finally some molecular aspects of radiation carcinogenesis are discussed. (H.W.). 22 refs.; 4 figs

  20. Radiation sickness

    Endoh, Masaru; Ishida, Yusei; Saeki, Mitsuaki

    1983-01-01

    The frequency of radiation sickness in 1,060 patients treated at our Department was 12.8 percent. It was frequent in patients with brain cancer (12 percent), whole spine cancer (47 percent), uterus cancer (28 percent), lung cancer (22 percent) and esophagus cancer (12 percent). Radiation sickness following X-irradiation was studied in its relation to patient's age, size of radiation fields, dosis and white blood cell count. However, we could not find any definite clinical feature relevant to occurrence. There are many theories published concerning the mechanism of radiation sickness. Clinical experiences have shown that radiation sickness cannot be explained by one theory alone but by several theories such as those based on psychology, stress or histamine. (author)

  1. Radiation safety

    Auxier, J.A.

    1977-01-01

    Data available on the biological effects of radiation on man are reviewed, with emphasis on dose response to low LET and high LET radiation sources, and the effects of dose rate. Existing guides for radiation protection were formulated largely on the basis of tumor induction in the bone of radium dial painters, but the ICRP/NCRP annual dose guides of 5 rem/yr are of the same general magnitude as the doses received in several parts of the world from the natural radiation environment. Because of the greater sensitivity of rapidly dividing cells and the assumption that radiation occupations would not begin before the age of eighteen, maximum exposure levels were set as 5 (N-18) rem/yr, where N is the exposed worker's age in years. However, in the case of the natural radiation environment, exposure commences, in a sense, with the exposure of the ovum of the individual's mother; and the ovum is formed during the fetal development of the mother. In occupational exposures, the professional health physicist has always practiced the as low as practical philosophy, and exposures have generally averaged far below the guidelines. The average annual exposure of the radiation worker in modern plants and laboratories is approximately equal to the average natural radiation environment exposure rate and far lower than the natural radiation environment in many parts of the world. There are numerous complications and uncertainties in quantifying radiation effects on humans, however, the greatest is that due to having to extrapolate from high dose levels at which effects have been measured and quantified, to low levels at which most exposures occur but at which no effects have been observed

  2. Radiation safety

    Van Riessen, A.

    2002-01-01

    Full text: Experience has shown that modem, fully enclosed, XRF and XRD units are generally safe. This experience may lead to complacency and ultimately a lowering of standards which may lead to accidents. Maintaining awareness of radiation safety issues is thus an important role for all radiation safety officers. With the ongoing progress in technology, a greater number of radiation workers are more likely to use a range of instruments/techniques - eg portable XRF, neutron beam analysis, and synchrotron radiation analysis. The source for each of these types of analyses is different and necessitates an understanding of the associated dangers as well as use of specific radiation badges. The trend of 'suitcase science' is resulting in scientists receiving doses from a range of instruments and facilities with no coordinated approach to obtain an integrated dose reading for an individual. This aspect of radiation safety needs urgent attention. Within Australia a divide is springing up between those who work on Commonwealth property and those who work on State property. For example a university staff member may operate irradiating equipment on a University campus and then go to a CSIRO laboratory to operate similar equipment. While at the University State regulations apply and while at CSIRO Commonwealth regulations apply. Does this individual require two badges? Is there a need to obtain two licences? The application of two sets of regulations causes unnecessary confusion and increases the workload of radiation safety officers. Radiation safety officers need to introduce risk management strategies to ensure that both existing and new procedures result in risk minimisation. A component of this strategy includes ongoing education and revising of regulations. AXAA may choose to contribute to both of these activities as a service to its members as well as raising the level of radiation safety for all radiation workers. Copyright (2002) Australian X-ray Analytical

  3. Moessbauer spectroscopy with synchrotron radiation

    Bergmann, U.

    1994-01-01

    The short pulse nature of synchrotron radiation makes it possible to perform Moessbauer spectroscopy in the time domain, i.e. instead of measuring the transmitted intensity time integrated as a function of source/absorber velocity, the intensity of the scattered radiation is measured time differential. The resulting time spectrum is essentially source independent and complications in the data analysis which are related to the radioactive source are completely removed. Furthermore, the large brightness and well defined polarization of the synchrotron radiation can, e.g., speed up the data collection and facilitate studies of polarization phenomena. To illustrate these new spectroscopic possibilities, measurements of the temperature dependence and polarization dependence of forward scattering from alpha - sup 5 sup 7 Fe nuclei are presented and discussed 26 refs., 5 figs. (author)

  4. The cosmic microwave background radiation

    Wilson, R.W.

    1980-01-01

    The history is described of the discovery of microwave radiation of the cosmic background using the 20-foot horn antenna at the Bell Laboratories back in 1965. Ruby masers with travelling wave were used, featuring the lowest noise in the world. The measurement proceeded on 7 cm. In measuring microwave radiation from the regions outside the Milky Way continuous noise was discovered whose temperature exceeded the calculated contributions of the individual detection system elements by 3 K. A comparison with the theory showed that relict radiation from the Big Bang period was the source of the noise. The discovery was verified by measurements on the 20.1 cm wavelength and by other authors' measurements on 0.5 mm to 74 cm, and by optical measurements of the interstellar molecule spectrum. (Ha)

  5. Charting the Parameter Space of the 21-cm Power Spectrum

    Cohen, Aviad; Fialkov, Anastasia; Barkana, Rennan

    2018-05-01

    The high-redshift 21-cm signal of neutral hydrogen is expected to be observed within the next decade and will reveal epochs of cosmic evolution that have been previously inaccessible. Due to the lack of observations, many of the astrophysical processes that took place at early times are poorly constrained. In recent work we explored the astrophysical parameter space and the resulting large variety of possible global (sky-averaged) 21-cm signals. Here we extend our analysis to the fluctuations in the 21-cm signal, accounting for those introduced by density and velocity, Lyα radiation, X-ray heating, and ionization. While the radiation sources are usually highlighted, we find that in many cases the density fluctuations play a significant role at intermediate redshifts. Using both the power spectrum and its slope, we show that properties of high-redshift sources can be extracted from the observable features of the fluctuation pattern. For instance, the peak amplitude of ionization fluctuations can be used to estimate whether heating occurred early or late and, in the early case, to also deduce the cosmic mean ionized fraction at that time. The slope of the power spectrum has a more universal redshift evolution than the power spectrum itself and can thus be used more easily as a tracer of high-redshift astrophysics. Its peaks can be used, for example, to estimate the redshift of the Lyα coupling transition and the redshift of the heating transition (and the mean gas temperature at that time). We also show that a tight correlation is predicted between features of the power spectrum and of the global signal, potentially yielding important consistency checks.

  6. The infrared spectrum of Jupiter

    Ridgway, S. T.; Larson, H. P.; Fink, U.

    1976-01-01

    The principal characteristics of Jupiter's infrared spectrum are reviewed with emphasis on their significance for our understanding of the composition and temperature structure of the Jovian upper atmosphere. The spectral region from 1 to 40 microns divides naturally into three regimes: the reflecting region, thermal emission from below the cloud deck (5-micron hot spots), and thermal emission from above the clouds. Opaque parts of the Jovian atmosphere further subdivide these regions into windows, and each is discussed in the context of its past or potential contributions to our knowledge of the planet. Recent results are incorporated into a table of atmospheric composition and abundance which includes positively identified constituents as well as several which require verification. The limited available information about spatial variations of the infrared spectrum is presented

  7. Economic aspects of spectrum management

    Stibolt, R. D.

    1979-01-01

    Problems associated with the allocation of the radio frequency spectrum are addressed. It is observed that the current method very likely does not allocate the resource to those most valuing its use. Ecomonic criteria by which the effectiveness of resource allocation schemes can be judged are set forth and some thoughts on traditional objections to implementation of market characteristics into frequency allocation are offered. The problem of dividing orbit and spectrum between two satellite services sharing the same band but having significantly different system characteristics is discussed. The problem is compounded by the likelihood that one service will commence operation much sooner than the other. Some alternative schemes are offered that, within proper international constraints, could achieve a desired flexibility in the division of orbit and frequency between the two services domestically over the next several years.

  8. Rigidity spectrum of Forbush decrease

    Sakakibara, S.; Munakata, K.; Nagashima, K.

    1985-01-01

    Using data from neutron monitors and muon telescopes at surface and underground stations, the average rigidity spectrum of Forbush decreases (Fds) during the period of 1978-1982 were obtained. Thirty eight Ed-events are classified into two groups, Hard Fd and Soft FD according to size of Fd at the Sakashita station. It is found that a spectral form of a fractional-power type (P to the-gamma sub 1 (P+P sub c) to the -gamma sub2) is more suitable than that of a power-exponential type or of a power type with an upper limiting rigidity. The best fitted spectrum of the fractional-power type is expressed by gamma sub1 = 0.37, gamma sub2 = 0.89 and P subc = 10 GV for Hard Fd and gamma sub1 = 0.77, gamma sub2 = 1.02 and P sub c - 14GV for Soft Fd

  9. Cross-spectrum symbol synchronization

    Mccallister, R. D.; Simon, M. K.

    1981-01-01

    A popular method of symbol synchronization exploits one aspect of generalized harmonic analysis, normally referred to as the cross-spectrum. Utilizing nonlinear techniques, the input symbol energy is effectively concentrated onto multiples of the symbol clock frequency, facilitating application of conventional phase lock synchronization techniques. A general treatment of the cross-spectrum technique is developed and shown to be applicable across a broad class of symbol modulation formats. An important specific symbol synchronization application is then treated, focusing the general development to provide both insight and quantitative measure of the performance impact associated with variation in these key synchronization parameters: symbol modulation format, symbol transition probability, symbol energy to noise density ratio, and symbol rate to filter bandwidth ratio.

  10. Spectrum of PG 1700 + 518

    Wampler, E.J.

    1985-01-01

    Observations of PG 1700 + 518 show that this bright quasar has a very rich Fe II emission spectrum. In addition, there is a broad dip in spectral intensity to the blue of Mg II lambda 2800. It is argued that this dip is due to detached Mg II lambda 2800 absorption rather than to a gap between Fe II emission lines. Fe II transitions from 8 eV levels seem to be present in the spectrum. Also present are weak multiplets with the same upper levels as the strong optical multiplets 27 and 42. These observational data support the belief that the resonance lines of Fe II are optically thick and that the 8 eV levels are populated, presumably by fluorescence. Forbidden lines are very weak or absent in PG 1700 + 518. 11 references

  11. The W3 string spectrum

    Pope, C.N.; Stelle, K.S.

    1991-08-01

    We study the spectrum of W 3 strings. In particular, we show that for appropriately chosen space-time signature, one of the scalar fields is singled out be the spin-3 constraint and is ''frozen'': no creation operators from it can appear in physical states and the corresponding momentum must assume a specific fixed value. The remaining theory is unitary and resembles an ordinary string theory in d contains 26 with anomalies cancelled by appropriate background charges. (author). 8 refs

  12. Infrared spectrum of arsenic pentafluoride

    Blanchard, S.

    1967-01-01

    After a literature review about arsenic fluorides, we give several methods of obtaining very pure AsF 5 in order to ascertain the right spectrum of this compound. Our spectra fit well with Akers's observations, and we note that AsF 5 structure can be explained in terms of C 3v molecular symmetry, with the As-F bond stretching lying at 786 cm -1 and 811 cm -1 . (author) [fr

  13. Fast mixed spectrum reactor concept

    Kouts, H.J.C.; Fischer, G.J.; Cerbone, R.J.

    1979-04-01

    The Fast Mixed Spectrum Reactor is a highly promising concept for a fast reactor with improved features of proliferation resistance, and excellent utilization of uranium resources. In technology, it can be considered to be a branch of fast breeder development, though its operation and implications are different from those of FBR'S in important respects. Successful development programs are required in several areas to bring FMSR to reality, but the payoff from a successful program can be high

  14. Hadron spectrum from the lattice

    Gupta, R.

    1989-01-01

    Considerable progress has been made in the last year in deriving the spectrum from QCD in the quenched approximation. I review these results and show that we are close to getting results with 10% errors for the proton to rho mass ratio. I give a status report on ACD calculations with dynamical fermions being done by various groups. While these calculations are still exploratory, we have reached the stage where realistic simulations can be contemplated. 20 refs., 4 figs., 2 tabs

  15. Joint Electromagnetic Spectrum Management Operations

    2012-03-20

    promulgate command-specific policy and guidance for EMS use, the joint restricted frequency list (JRFL) process, the joint communications–electronics...joint communications–electronics operating instructions (JCEOI) and joint restricted frequency list (JRFL). Examples of FM include providing the...joint restricted frequency list Figure III-4. Joint Frequency Management Office Spectrum Management Process Chapter III III-10 JP 6-01 assignments

  16. Infrared spectrum of curium-244

    Conway, J.G.; Blaise, J.; Verges, J.

    1974-09-01

    The spectrum of curium-244 has been observed on the high resolution Fourier-transform spectrometer at Laboratoire Aime Cotton. An electrodeless lamp containing 50 μg of CmI 3 was run for 12 hours and 800,000 points were taken. A total of 1743 lines have been ascribed to curium and 87 percent of the lines have been assigned to transitions between known energy levels

  17. Irradiation spectrum and ionization-induced diffusion effects in ceramics

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

    1997-08-01

    There are two main components to the irradiation spectrum which need to be considered in radiation effects studies on nonmetals, namely the primary knock-on atom energy spectrum and ionizing radiation. The published low-temperature studies on Al{sub 2}O{sub 3} and MgO suggest that the defect production is nearly independent of the average primary knock-on atom energy, in sharp contrast to the situation for metals. On the other hand, ionizing radiation has been shown to exert a pronounced influence on the microstructural evolution of both semiconductors and insulators under certain conditions. Recent work on the microstructure of ion-irradiated ceramics is summarized, which provides evidence for significant ionization-induced diffusion. Polycrystalline samples of MgO, Al{sub 2}O{sub 3}, and MgAl{sub 2}O{sub 4} were irradiated with various ions ranging from 1 MeV H{sup +} to 4 MeV Zr{sup +} ions at temperatures between 25 and 650{degrees}C. Cross-section transmission electron microscopy was used to investigate the depth-dependent microstructural of the irradiated specimens. Dislocation loop nucleation was effectively suppressed in specimens irradiated with light ions, whereas the growth rate of dislocation loops was enhanced. The sensitivity to irradiation spectrum is attributed to ionization-induced diffusion. The interstitial migration energies in MgAl{sub 2}O{sub 4} and Al{sub 2}O{sub 3} are estimated to be {le}0.4 eV and {le}0.8 eV, respectively for irradiation conditions where ionization-induced diffusion effects are expected to be negligible.

  18. Spectrum monitoring procedures and techniques

    1990-07-01

    The first step towards operating an emitter on a test range is to contact the local frequency manager to establish a schedule. Since restricted radio frequency bands and operations are different at each test range location, most testing is accomplished by sharing the spectrum available with all range users. The telemetry bands in particular require spectrum activity scheduling. The objective is to resolve scheduling conflicts prior to operations. When two programs or projects request to use the same spectrum, their activity can be separated by quard bands, discrete frequencies, time, or operating locations (terrain masking). Priorities assigned to each program usually dictate which program will be scheduled first; however, use of priorities to schedule activities should be avoided and only considered as a last resort. When a scheduling conflict cannot be resolved using these techniques, it is brought to the attention of the responsible program managers. When scheduling activities involve other federal or nonfederal agencies, it is in the best interest of program managers to be as flexible as possible.

  19. Genetics Home Reference: autism spectrum disorder

    ... Share: Email Facebook Twitter Home Health Conditions ASD Autism spectrum disorder Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Autism spectrum disorder ( ASD ) is a condition that appears very early ...

  20. Autism Spectrum Disorder and Mitochondrial Disease

    ... Search Form Controls Cancel Submit Search the CDC Autism Spectrum Disorder (ASD) Note: Javascript is disabled or is not ... with a mitochondrial disease: may also have an autism spectrum disorder, may have some of the symptoms/signs of ...

  1. Autism Spectrum Disorder (ASD): Related Topics

    ... Facebook Tweet Share Compartir Q: Do vaccines cause autism spectrum disorder (ASD)? A: Many studies that have looked at whether there is a relationship between vaccines and autism spectrum disorder (ASD). To date, the studies continue to show ...

  2. Handbook on synchrotron radiation, v.2

    1987-01-01

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

  3. 3D radiative transfer in stellar atmospheres

    Carlsson, M

    2008-01-01

    Three-dimensional (3D) radiative transfer in stellar atmospheres is reviewed with special emphasis on the atmospheres of cool stars and applications. A short review of methods in 3D radiative transfer shows that mature methods exist, both for taking into account radiation as an energy transport mechanism in 3D (magneto-) hydrodynamical simulations of stellar atmospheres and for the diagnostic problem of calculating the emergent spectrum in more detail from such models, both assuming local thermodynamic equilibrium (LTE) and in non-LTE. Such methods have been implemented in several codes, and examples of applications are given.

  4. Quantitative risk in radiation protection standards

    Bond, V.P.

    1978-01-01

    The bases for developing quantitative assessment of exposure risks in the human being, and the several problems that accompany the assessment and introduction of the risk of exposure to high and low LET radiation into radiation protection, will be evaluated. The extension of the pioneering radiation protection philosophies to the control of other hazardous agents that cannot be eliminated from the environment will be discussed, as will the serious misunderstandings and misuse of concepts and facts that have inevitably surrounded the application to one agent alone, of the protection philosophy that must in time be applied to a broad spectrum of potentially hazardous agents. (orig.) [de

  5. Ultrasonic backward radiation on painted rough interface

    Kwon, Yong Gyu; Yoon, Seok Soo; Kwon, Sung Duck

    2002-01-01

    The angular dependence(profile) of backscattered ultrasound was measured for steel and brass specimens with periodical surface roughness (1-71μm). Backward radiations showed more linear dependency than normal profile. Direct amplitude increased and averaging amplitude decreased with surface roughness. Painting treatment improved the linearity in direct backward radiation below roughness of 0.03. Scholte and Rayleigh-like waves were observed in the spectrum of averaging backward radiation on periodically rough surface. Painting on periodically rough surface could be used in removing the interface mode effect by periodic roughness.

  6. Radiation therapy

    Bader, J.L.; Glatstein, E.

    1987-01-01

    The radiation oncologist encounters the critically ill immunosuppressed patient in four settings. First, the newly diagnosed cancer patient presents for initial evaluation and treatment, with immunosuppression from the cancer itself, malnutrition, concomitant infectious disease, prior drug or alcohol abuse or other medical problems. Second, the previously treated cancer patient presents with metastatic or recurrent primary cancer causing local symptoms. Immune dysfunction in this setting may be due to prior chemotherapy and/or radiation as well as any of the original factors. Third, the patient previously treated with radiation presents with a life-threatening problem possibly due to complications of prior therapy. In this setting, the radiation oncologist is asked to evaluate the clinical problem and to suggest whether radiation might be causing part or all of the problem and what can be done to treat these sequelae of radiation. Fourth, the patient with a benign diagnosis (not cancer) is seen with a problem potentially emeliorated by radiation (e.g., kidney transplant rejection, preparation for transplant, or intractable rheumatoid arthritis). This chapter reviews these four issues and presents clinical and radiobiologic principles on which recommendations for therapy are based

  7. Calculating the electron temperature in the lightning channel by continuous spectrum

    Xiangcheng, DONG; Jianhong, CHEN; Xiufang, WEI; Ping, YUAN

    2017-12-01

    Based on the theory of plasma continuous radiation, the relationship between the emission intensity of bremsstrahlung and recombination radiation and the plasma electron temperature is obtained. During the development process of a return stroke of ground flash, the intensity of continuous radiation spectrum is separated on the basis of the spectrums with obviously different luminous intensity at two moments. The electron temperature of the lightning discharge channel is obtained through the curve fitting of the continuous spectrum intensity. It is found that electron temperature increases with the increase of wavelength and begins to reduce after the peak. The peak temperature of the two spectra is close to 25 000 K. To be compared with the result of discrete spectrum, the electron temperature is fitted by the O I line and N II line of the spectrum respectively. The comparison shows that the high temperature value is in good agreement with the temperature of the lightning core current channel obtained from the ion line information, and the low temperature at the high band closes to the calculation result of the atomic line, at a low band is lower than the calculation of the atomic line, which reflects the temperature of the luminous channel of the outer corona.

  8. Auction design for the wireless spectrum market

    Lin, Peng; Zhang, Qian

    2014-01-01

    This Brief introduces the wireless spectrum market and discusses the current research for spectrum auctions. It covers the unique properties of spectrum auction, such as interference relationship, reusability, divisibility, composite effect and marginal effect, while also proposing how to build economic incentives into the network architecture and protocols in order to optimize the efficiency of wireless systems.Three scenarios for designing new auctions are demonstrated. First, a truthful double auction scheme for spectrum trading considering both the heterogeneous propagation properties of c

  9. SpecNet: Spectrum Sensing Sans Frontieres

    Iyer, Anand Padmanabha; Chintalapudi, Krishna; Navda, Vishnu; Ramjee, Ramachandran; Padmanabhan, Venkata N; Murthy, Chandra R

    2011-01-01

    While the under-utilization of licensed spectrum based on measurement studies conducted in a few developed countries has spurred lots of interest in opportunistic spectrum access, there exists no infrastructure today for measuring real-time spectrum occupancy across vast geographical regions. In this paper, we present the design and implementation of SpecNet, a first-of-its-kind platform that allows spectrum analyzers around the world to be networked and efficiently used in a coordinated manner...

  10. Imaging with electromagnetic spectrum applications in food and agriculture

    Jayasuriya, Hemantha

    2014-01-01

    This book demonstrates how imaging techniques, applying different frequency bands from the electromagnetic spectrum, are used in scientific research. Illustrated with numerous examples this book is structured according to the different radiation bands: From Gamma-rays over UV and IR to radio frequencies. In order to ensure a clear understanding of the processing methodologies, the text is enriched with descriptions of how digital images are formed, acquired, processed and how to extract information from them. A special emphasis is given to the application of imaging techniques in food and agriculture research.

  11. Photoneutron spectrum measured with Bonner Spheres in Planetary method mode

    Benites R, J. [Centro Estatal de Cancerologia de Nayarit, Servicio de Seguridad Radiologica, Calz. de la Cruz 118 Sur, 63000 Tepic, Nayarit (Mexico); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Apdo. Postal 336, 98000 Zacatecas (Mexico); Velazquez F, J., E-mail: jlbenitesr@prodigy.net.mx [Universidad Autonoma de Nayarit, Posgrado en Ciencias Biologico Agropecuarias, Carretera Tepic-Compostela Km 9, 63780 Jalisco-Nayarit (Mexico)

    2012-10-15

    We measured the spectrum of photoneutrons at 100 cm isocenter linear accelerator (Linac) Varian ix operating at 15 MV Bremsstrahlung mode. In this process was used a radiation field of 20 x 20 cm{sup 2} at a depth of 5 cm in a solid water phantom with dimensions of 30 x 30 x 15 cm{sup 3}. The measurement was performed with a system using it Bonner Spheres spectrometric method Planetary mode. As neutron detector of the spectrometer is used thermoluminescent dosimeters pairs of type 600 and 700. (Author)

  12. Photoneutron spectrum measured with Bonner Spheres in Planetary method mode

    Benites R, J.; Vega C, H. R.; Velazquez F, J.

    2012-10-01

    We measured the spectrum of photoneutrons at 100 cm isocenter linear accelerator (Linac) Varian ix operating at 15 MV Bremsstrahlung mode. In this process was used a radiation field of 20 x 20 cm 2 at a depth of 5 cm in a solid water phantom with dimensions of 30 x 30 x 15 cm 3 . The measurement was performed with a system using it Bonner Spheres spectrometric method Planetary mode. As neutron detector of the spectrometer is used thermoluminescent dosimeters pairs of type 600 and 700. (Author)

  13. The spectrum of density perturbations in an expanding universe

    Silk, J.

    1974-01-01

    The basic dynamic equations that govern the evolution of perturbations in a Friedmann-Lemaitre universe are derived. General solutions describing the evolution of adiabatic perturbations in the density of matter are obtained, and the choice of the appropriate initial conditions is examined. The various perturbation modes are compared, and the effects of decoupling on the perturbation spectrum are studied. The scheme used to follow the evolution of density perturbations through decoupling is based on an extension of the Eddington approximation to the radiative transfer equation, and is strictly valid in both optically thick and thin limits.

  14. [Autism spectrum disorder and suicidality].

    Huguet, G; Contejean, Y; Doyen, C

    2015-09-01

    Most studies on suicide exclude subjects with autism spectrum disorders, yet there is a risk group. The purpose of this article is to present the data in the literature regarding the clinical and epidemiological characteristics of suicidality in subjects with autism spectrum disorders and to identify the factors that promote the transition to action. This review was carried out using the data set collected in Medline PubMed, items with "autism spectrum disorder", "pervasive developmental disorder", "Asperger's syndrome", "suicide", "suicide attempt", and "suicide behavior". In all subjects from our research on PubMed, 21.3% of subjects with autism spectrum disorder reported suicidal ideation, have attempted suicide or died by suicide (115 out of 539 subjects) and 7.7% of subjects supported for suicidal thoughts or attempted suicide exhibited an autism spectrum disorder (62 out of 806 subjects), all ages combined. Suicidal ideation and morbid preoccupation are particularly common in adolescents and young adults. Suicide attempts are accompanied by a willingness for death and can lead to suicide. They are more common in high-functioning autism and Asperger subjects. The methods used are often violent and potentially lethal or fatal in two cases published. Suicide risk depends on many factors that highlight the vulnerability of these subjects, following autistic and developmental symptoms. Vulnerability complicating the diagnosis of comorbid depressive and anxiety disorders are major factors associated with suicidality. Vulnerability but also directly related to suicidality, since the origin of physical and sexual abuse and victimization by peers assigning them the role of "scapegoat" are both responsible for acting out. Given the diversity of factors involved in the risk of suicide in this population, this does not validate "a" program of intervention, but the intervention of "customized programs". Their implementation should be as early as possible in order to treat

  15. Generating a heated fluid using an electromagnetic radiation-absorbing complex

    Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

    2018-01-09

    A vessel including a concentrator configured to concentrate electromagnetic (EM) radiation received from an EM radiation source and a complex configured to absorb EM radiation to generate heat. The vessel is configured to receive a cool fluid from the cool fluid source, concentrate the EM radiation using the concentrator, apply the EM radiation to the complex, and transform, using the heat generated by the complex, the cool fluid to the heated fluid. The complex is at least one of consisting of copper nanoparticles, copper oxide nanoparticles, nanoshells, nanorods, carbon moieties, encapsulated nanoshells, encapsulated nanoparticles, and branched nanostructures. Further, the EM radiation is at least one of EM radiation in an ultraviolet region of an electromagnetic spectrum, in a visible region of the electromagnetic spectrum, and in an infrared region of the electromagnetic spectrum.

  16. Radiation physics

    Nam, Sang Hui

    1991-02-01

    This book deals with radiation physics, which introduces atomic theory and an atomic nucleus of materials, conception of an atom and materials, wave and particle, X ray generation and character, a radioactive element and change law, nature of radioactivity, neutron rays, fission, alpha collapse and beta collage and a neutrino collapse of artificial radioactivity such as collapse of artificial nucleus and artificial radioactivity and radiative capture, interaction with materials like interaction between a charged particle and materials and interaction among X-ray, r-ray and materials, radiation of quantity and unit and a charged particle accelerator.

  17. Ionizing radiation

    Passchier, W.F.

    1988-01-01

    This report is part two from the series 'Future explorations' of the Dutch Counsil for Public Health. It contains contributions on biological effects of radiation in which information is presented on research into the occurrence of cancer in patients treated with radiotherapy and irradiated laboratory animals, on the effects of prenatal irradiation, and on the possibile, only in laboratory-animal research demonstrated, effects of irradiation in offspring of irradiated parents. In other contributions, which put the 'link' between the radiology and the practical radiation hygienics, it appears that the increased scientific knowledge does not make it easier to design radiation-hygienic standards and rules. (H.W.). refs.; figs.; tabs

  18. Radiation safety

    1996-04-01

    Most of the ionizing radiation that people are exposed to in day-to-day activities comes from natural, rather than manmade, sources. The health effects of radiation - both natural and artificial - are relatively well understood and can be effectively minimized through careful safety measures and practices. The IAEA, together with other international and expert organizations, is helping to promote and institute Basic Safety Standards on an international basis to ensure that radiation sources and radioactive materials are managed for both maximum safety and human benefit

  19. Environmental radiation monitoring system with GPS (global positioning system)

    Komoto, Itsuro

    2000-01-01

    This system combines a radiation monitoring car with GPS and a data processor (personal computer). It distributes the position information acquired through GPS to the data such as measured environmental radiation dose rate and energy spectrum. It also displays and edits the data for each measuring position on a map. Transmitting the data to the power station through mobile phone enables plan managers to easily monitor the environmental radiation dose rate nearby and proper emergency monitoring. (author)

  20. Computer modelling of statistical properties of SASE FEL radiation

    Saldin, E. L.; Schneidmiller, E. A.; Yurkov, M. V.

    1997-01-01

    The paper describes an approach to computer modelling of statistical properties of the radiation from self amplified spontaneous emission free electron laser (SASE FEL). The present approach allows one to calculate the following statistical properties of the SASE FEL radiation: time and spectral field correlation functions, distribution of the fluctuations of the instantaneous radiation power, distribution of the energy in the electron bunch, distribution of the radiation energy after monochromator installed at the FEL amplifier exit and the radiation spectrum. All numerical results presented in the paper have been calculated for the 70 nm SASE FEL at the TESLA Test Facility being under construction at DESY

  1. Experiences With Area Specific Spectrum Stripping of Nai(Tl) Gamma Spectra

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim

    2006-01-01

    Abstract Processing of airborne and carborne gamma-ray spectra (AGS and CGS) often includes the stripping (elimination) of the signals from natural radioactivity. Hereby the net result becomes the signals from manmade radioactivity or other radiation anomalies. The parameters needed for spectrum ...

  2. Mercury depletion as a way of changing the emission spectrum of a fluorescent lamp

    Bakker, L.P.; Kroesen, G.M.W.

    2000-01-01

    We present a promising option for changing the emission spectrum of a fluorescent lamp. In a neon/mercury discharge, neon radiation is produced when the mercury density is sufficiently low. Under certain discharge conditions, radial cathaphoresis causes depletion of mercury atoms in the center of

  3. Broadband transmission grating spectrometer for measuring the emission spectrum of EUV sources

    Bayraktar, Muharrem; Bastiaens, Hubertus M.J.; Bruineman, Caspar; Vratzov, Boris; Bijkerk, Frederik

    2016-01-01

    Extreme ultraviolet (EUV) light sources and their optimization for emission within a narrow wavelength band are essential in applications such as photolithography. Most light sources however also emit radiation outside this wavelength band and have a spectrum extending up to deep ultraviolet (DUV)

  4. The e− Spectrum and e+ Spectrum from AMS

    CERN. Geneva

    2015-01-01

    Precision measurements by AMS on the ISS of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30 GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index.

  5. The electromagnetic spectrum : an overview

    Major, G.

    1988-01-01

    Ionizing and non-ionizing radiations should be practically non-issues for Australian occupational health and safety professionals but the person who ignores them does so at his or her risk. The prophets of doom will ensure that ionizing and non-ionizing radiation stay on the agenda for a least another generation and occupational health and safety advisers will need to remain well informed on the subject so that they will be competent to reassure over-anxious employees and employers alike

  6. Application of thermoluminescence dosimeter on the measurement of hard X-ray pulse energy spectrum

    Song Zhaohui; Wang Baohui; Wang Kuilu; Hei Dongwei; Sun Fengrong; Li Gang

    2003-01-01

    This paper introduces the application of thermoluminescence dosimeter (TLD) which composed by TLD-3500 reader and GR-100 M chips on the measurement of hard X-ray pulse energy spectrum. The idea using Filter Fluorescence Method (FFM) and TLD to measure hard X-ray pulse energy spectrum (from 10 keV to 100 keV) is discussed in details. Considering all the factors of the measuring surrounding, the measurement system of hard X-ray pulse has been devised. The calibration technique of absolute energy response of TLD is established. This method has been applied successfully on the radiation parameters measurement of the huge pulse radiation device-high-power pulser I. Hard X-ray pulse energy spectrum data of the pulser are acquired

  7. The application of thermoluminescence dosimeter on the measurement of hard X-ray pulse energy spectrum

    Song Zhaohui; Wang Baohui; Wang Kuilu; Hei Dongwei; Sun Fengrong; Li Gang

    2001-01-01

    This paper introduce the application of thermoluminescence dosimeter (TLD) which composed by TLD-3500 Reader and TLD-100M chips on the measurement of hard X-ray pulse energy spectrum. The idea, using Filter Fluorescence Method (FFM) and TLD to measure hard X-ray pulse energy spectrum (from 10 keV to 100 keV), is discussed in details. Considering all the factors of the measuring surroundings, the measurement system of hard X-ray pulse has been devised. The calibration technique of absolute energy response of TLD is established. This method has been applied successfully on the radiation parameters measurement of the huge pulse radiation device -high-power pulser I. Hard X-ray pulse energy spectrum data of the pulser are acquired

  8. Study of the initial processes of radiation effects using synchrotron radiation

    Kobayashi, Katsumi

    1990-01-01

    Necessity for the research of production mechanisms of molecular damages in biological system and usefulness of monochromatic soft X-ray in these studies are described. Synchrotron radiation are introduced as a strong light source with continuous spectrum. Practically, it is the only light source in soft X-ray and vacuum UV region. Development of irradiation apparatus for radiation biology and recent results using various biological systems are reviewed. (author)

  9. Low temperature experiments in radiation biophysics

    Moan, J.

    1977-01-01

    The reasons for performing experiments in radiation biophysics at low temperatures, whereby electron spectra may be studied, are explained. The phenomenon of phosphorescence spectra observed in frozen aqueous solutions of tryptophan and adenosine is also described. Free radicals play an important part in biological radiation effects and may be studied by ESR spectroscopy. An ESR spectrum of T 1 bacteriophages irradiated dry at 130K is illustrated and discussed. Hydrogen atoms, which give lines on the spectrum, are believed to be those radiation products causing most biological damage in a dry system. Low temperature experiments are of great help in explaining the significance of direct and indirect effects. This is illustrated for the case of trypsin. (JIW)

  10. A Method for Improving Reliability of Radiation Detection using Deep Learning Framework

    Chang, Hojong; Kim, Tae-Ho; Han, Byunghun; Kim, Hyunduk; Kim, Ki-duk

    2017-01-01

    Radiation detection is essential technology for overall field of radiation and nuclear engineering. Previously, technology for radiation detection composes of preparation of the table of the input spectrum to output spectrum in advance, which requires simulation of numerous predicted output spectrum with simulation using parameters modeling the spectrum. In this paper, we propose new technique to improve the performance of radiation detector. The software in the radiation detector has been stagnant for a while with possible intrinsic error of simulation. In the proposed method, to predict the input source using output spectrum measured by radiation detector is performed using deep neural network. With highly complex model, we expect that the complex pattern between data and the label can be captured well. Furthermore, the radiation detector should be calibrated regularly and beforehand. We propose a method to calibrate radiation detector using GAN. We hope that the power of deep learning may also reach to radiation detectors and make huge improvement on the field. Using improved radiation detector, the reliability of detection would be confident, and there are many tasks remaining to solve using deep learning in nuclear engineering society.

  11. Synchrotron Radiation

    Asfour, F.I

    2000-01-01

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

  12. Radiating confidence

    Rush, P.

    1988-01-01

    Radiation monitoring systems for operators handling radioactive wastes are described. These include a personnel monitoring system which is suitable for small groups (ie as few as 50) of personnel. The use of microelectronics enable facilities such as automatic personal dose recording with three accumulative registers and automatic reporting of exceeded dose limits. At a controlled entrance the user is identified with a personal identification number. Exit is then also monitored. The use of pocket dosimeters increase the flexibility of this system. In another system a 'rotary man lock' only allows exit from the radiation controlled zone when satisfactory radiation checks have been made. The radiation and security checks available with this system are described. A 'sack monitor' for low level wastes contained in plastic bags is illustrated. (U.K.)

  13. Radiation damage

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  14. Synchrotron radiation

    Helliwell, J.R.; Walker, R.P.

    1985-01-01

    A detailed account of the research work associated with the Synchrotron Radiation Source at Daresbury Laboratory, United Kingdom, in 1984/85, is presented in the Appendix to the Laboratory's Annual Report. (U.K.)

  15. Radiation curing

    Wendrinsky, J.

    1987-04-01

    In the beginning of the seventies the two types of radiation sources applied in industrial processes, electron radiation and UV, had been given rather optimistic forecasts. While UV could succeed in the field of panel and film coating, electron radiation curing seems to gain success in quite new fields of manufacturing. The listing of the suggested applications of radiation curing and a comparison of both advantages and disadvantages of this technology are followed by a number of case studies emphasizing the features of these processes and giving some examplary calculations. The data used for the calculations should provide an easy calculation of individual manufacturing costs if special production parameters, investment or energy costs are employed. (Author)

  16. Infrared radiation

    Moss, C.E.; Ellis, R.J.; Murray, W.E.; Parr, W.H.

    1989-01-01

    All people are exposed to IR radiation from sunlight, artificial light and radiant heating. Exposures to IR are quantified by irradiance and radiant exposure to characterize biological effects on the skin and cornea. However, near-IR exposure to the retina requires knowledge of the radiance of the IR source. With most IR sources in everyday use the health risks are considered minimal; only in certain high radiant work environments are individuals exposed to excessive levels. The interaction of IR radiation with biological tissues is mainly thermal. IR radiation may augment the biological response to other agents. The major health hazards are thermal injury to the eye and skin, including corneal burns from far-IR, heat stress, and retinal and lenticular injury from near-IR radiation. 59 refs, 13 figs, 2 tabs

  17. Radiation enteritis

    ... and tobacco Almost all milk products Coffee, tea, chocolate, and sodas with caffeine Foods containing whole bran ... Call your provider if you are having radiation therapy or have had it in the past and ...

  18. Activity, exposure rate and spectrum prediction with Java programming

    Sahin, D.; Uenlue, K.

    2009-01-01

    In order to envision the radiation exposure during Neutron Activation Analysis (NAA) experiments, a software called Activity Predictor is developed using Java TM programming language. The Activity Predictor calculates activities, exposure rates and gamma spectra of activated samples for NAA experiments performed at Radiation Science and Engineering Center (RSEC), Penn State Breazeale Reactor (PSBR). The calculation procedure for predictions involves both analytical and Monte Carlo methods. The Activity Predictor software is validated with a series of activation experiments. It has been found that Activity Predictor software calculates the activities and exposure rates precisely. The software also predicts gamma spectrum for each measurement. The predicted spectra agreed partially with measured spectra. The error in net photo peak areas varied from 4.8 to 51.29%, which is considered to be due to simplistic modeling, statistical fluctuations and unknown contaminants in the samples. (author)

  19. Contribution of domain wall networks to the CMB power spectrum

    Lazanu, A.; Martins, C.J.A.P.; Shellard, E.P.S.

    2015-01-01

    We use three domain wall simulations from the radiation era to the late-time dark energy domination era based on the PRS algorithm to calculate the energy–momentum tensor components of domain wall networks in an expanding universe. Unequal time correlators in the radiation, matter and cosmological constant epochs are calculated using the scaling regime of each of the simulations. The CMB power spectrum of a network of domain walls is determined. The first ever quantitative constraint for the domain wall surface tension is obtained using a Markov chain Monte Carlo method; an energy scale of domain walls of 0.93 MeV, which is close but below the Zel'dovich bound, is determined

  20. Contribution of domain wall networks to the CMB power spectrum

    Lazanu, A., E-mail: A.Lazanu@damtp.cam.ac.uk [Centre for Theoretical Cosmology, Department of Applied Mathematics and Theoretical Physics, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Martins, C.J.A.P., E-mail: Carlos.Martins@astro.up.pt [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, 4150-762 Porto (Portugal); Shellard, E.P.S., E-mail: E.P.S.Shellard@damtp.cam.ac.uk [Centre for Theoretical Cosmology, Department of Applied Mathematics and Theoretical Physics, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2015-07-30

    We use three domain wall simulations from the radiation era to the late-time dark energy domination era based on the PRS algorithm to calculate the energy–momentum tensor components of domain wall networks in an expanding universe. Unequal time correlators in the radiation, matter and cosmological constant epochs are calculated using the scaling regime of each of the simulations. The CMB power spectrum of a network of domain walls is determined. The first ever quantitative constraint for the domain wall surface tension is obtained using a Markov chain Monte Carlo method; an energy scale of domain walls of 0.93 MeV, which is close but below the Zel'dovich bound, is determined.

  1. Contribution of domain wall networks to the CMB power spectrum

    A. Lazanu

    2015-07-01

    Full Text Available We use three domain wall simulations from the radiation era to the late-time dark energy domination era based on the PRS algorithm to calculate the energy–momentum tensor components of domain wall networks in an expanding universe. Unequal time correlators in the radiation, matter and cosmological constant epochs are calculated using the scaling regime of each of the simulations. The CMB power spectrum of a network of domain walls is determined. The first ever quantitative constraint for the domain wall surface tension is obtained using a Markov chain Monte Carlo method; an energy scale of domain walls of 0.93 MeV, which is close but below the Zel'dovich bound, is determined.

  2. Novel photoinducible protective system in the Candida Guilliermondii under mid-ultraviolet radiation effect

    Frajkin, G.Ya.; Pinyaskina, E.V.; Strakhovskaya, M.G.

    1995-01-01

    Resistance of the Candida guilliermondii cells to ultraviolet radiation (290-320 nm, 400-750 nm) is studied. Presence of previously unknown photoinducible protective mechanism in yeasts, providing for increase in cell stability to mid-ultraviolet radiation, biologically most active in the solar radiation spectrum, is revealed. 9 refs.; 3 figs

  3. Synchrotron radiation

    Poole, M.W.; Lea, K.R.

    1982-01-01

    A report is given on the work involving the Synchrotron Radiation Division of the Daresbury Laboratory during the period January 1981 - March 1982. Development of the source, beamlines and experimental stations is described. Progress reports from individual investigators are presented which reveal the general diversity and interdisciplinary nature of the research which benefits from access to synchrotron radiation and the associated facilities. Information is given on the organisation of the Division and publications written by the staff are listed. (U.K.)

  4. Radiation safety

    Goetz, B.B.; Murphy, C.H.

    1987-01-01

    In medicine, as in other fields of scientific endeavor, the development of advanced and specialized techniques has resulted in increased hazards for employees. However, by possessing both an appreciation of the proper use of factors that regulate radiation exposure around radiology equipment and a knowledge of the biologic effects of radiation, which can include possible genetic and somatic consequences, it is possible to maximize the usefulness of these valuable procedures while minimizing the risk to medical personnel involved with patient care

  5. Radiation shielding

    Yue, D.D.

    1979-01-01

    Details are given of a cylindrical electric penetration assembly for carrying instrumentation leads, used in monitoring the performance of a nuclear reactor, through the containment wall of the reactor. Effective yet economical shielding protection against both fast neutron and high-energy gamma radiation is provided. Adequate spacing within the assembly allows excessive heat to be efficiently dissipated and means of monitoring all potential radiation and gas leakage paths are provided. (UK)

  6. Radiation protection

    Koelzer, W.

    1976-01-01

    The lecture is divided into five sections. The introduction deals with the physical and radiological terms, quantities and units. Then the basic principles of radiological protection are discussed. In the third section attention is paid to the biological effects of ionizing radiation. The fourth section deals with the objectives of practical radiological protection. Finally the emergency measures are discussed to be taken in radiation accidents. (HP) [de

  7. Synchrotron radiation

    Norman, D.; Walker, R.P.; Durham, P.J.; Ridley, P.A.

    1986-01-01

    The paper on synchrotron radiation is the appendix to the Daresbury (United Kingdom) annual report, 1985/86. The bulk of the volume is made up of the progress reports for the work carried out during the year under review using the Synchrotron Radiation Source (SRS) at Daresbury. The Appendix also contains: the scientific programmes at the the SRS, progress on beamlines, instrumentation and computing developments, and activities connected with accelerator development. (U.K.)

  8. Radiation Transport

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  9. Radiation myelopathy

    Howell, D A [Derbyshire Royal Infirmary, Derby (UK)

    1979-10-01

    Following high-dose radiotherapy treatment of tumours, there is a risk of destructive radiation myelopathy developing a few months later as a result of spinal cord irradiation. The emphasis of the present article is on the mechanism of the development of radiation myelopathy. It is suggested that, in the irradiated segments, the normal endothelial cells lining the penetrating arteries and capillaries are replaced by abnormal cells during the latent period. Radiation-induced mutations or chromosomal aberrations are contained in these cells, thus provoking an immunological response. During the attempted rejection of these cells, protein-rich plasma filtrate is leaked into the artery walls and nervous tissue, causing the destructive myelopathy. The signs of paralysis of spinal cord function may be caused either by infarcts or by oedema of the white matter. Since both diagnosis and treatment are difficult, it is necessary to concentrate on prevention by, whenever possible, reducing radiation doses to below tolerance limits during radiotherapy. As regards radiotherapy in children, it is currently believed that there is little or no difference in radiation tolerance between the child and the adult nervous system. Some early benign forms of radiation myelopathy are also briefly discussed.

  10. Radiation myelopathy

    Howell, D.A.

    1979-01-01

    Following high-dose radiotherapy treatment of tumours, there is a risk of destructive radiation myelopathy developing a few months later as a result of spinal cord irradiation. The emphasis of the present article is on the mechanism of the development of radiation myelopathy. It is suggested that, in the irradiated segments, the normal endothelial cells lining the penetrating arteries and capillaries are replaced by abnormal cells during the latent period. Radiation-induced mutations or chromosomal aberrations are contained in these cells, thus provoking an immunological response. During the attempted rejection of these cells, protein-rich plasma filtrate is leaked into the artery walls and nervous tissue, causing the destructive myelopathy. The signs of paralysis of spinal cord function may be caused either by infarcts or by oedema of the white matter. Since both diagnosis and treatment are difficult, it is necessary to concentrate on prevention by, whenever possible, reducing radiation doses to below tolerance limits during radiotherapy. As regards radiotherapy in children, it is currently believed that there is little or no difference in radiation tolerance between the child and the adult nervous system. Some early benign forms of radiation myelopathy are also briefly discussed. (UK)

  11. Hawking spectrum for a fiber-optical analog of the event horizon

    Bermudez, David; Leonhardt, Ulf

    2016-05-01

    Hawking radiation has been regarded as a more general phenomenon than in gravitational physics, in particular in laboratory analogs of the event horizon. Here we consider the fiber-optical analog of the event horizon, where intense light pulses in fibers establish horizons for probe light. Then, we calculate the Hawking spectrum in an experimentally realizable system. We found that the Hawking radiation is peaked around group-velocity horizons in which the speed of the pulse matches the group velocity of the probe light. The radiation nearly vanishes at the phase horizon where the speed of the pulse matches the phase velocity of light.

  12. Radiation injuries/ionizing radiation

    Gooden, D.S.

    1991-01-01

    This book was written to aid trial attorneys involved in radiation litigation. Radiologists and medical physicists will also find it helpful as they prepare for trial, either as a litigant or an expert witness. Two chapters present checklists to guide attorneys for both plaintiffs and defendants. Gooden titles these checklists Elements of Damages and Elements of Proof and leads the reader to conclusions about each of these. One section that will be particularly helpful to attorneys contains sample interrogatories associated with a case of alleged radiation exposure resulting in a late radiation injury. There are interrogatories for the plaintiff to ask the defendant and for the defendant to ask the plaintiff

  13. Coalition Formation and Spectrum Sharing of Cooperative Spectrum Sensing Participants.

    Zhensheng Jiang; Wei Yuan; Leung, Henry; Xinge You; Qi Zheng

    2017-05-01

    In cognitive radio networks, self-interested secondary users (SUs) desire to maximize their own throughput. They compete with each other for transmit time once the absence of primary users (PUs) is detected. To satisfy the requirement of PU protection, on the other hand, they have to form some coalitions and cooperate to conduct spectrum sensing. Such dilemma of SUs between competition and cooperation motivates us to study two interesting issues: 1) how to appropriately form some coalitions for cooperative spectrum sensing (CSS) and 2) how to share transmit time among SUs. We jointly consider these two issues, and propose a noncooperative game model with 2-D strategies. The first dimension determines coalition formation, and the second indicates transmit time allocation. Considering the complexity of solving this game, we decompose the game into two more tractable ones: one deals with the formation of CSS coalitions, and the other focuses on the allocation of transmit time. We characterize the Nash equilibria (NEs) of both games, and show that the combination of these two NEs corresponds to the NE of the original game. We also develop a distributed algorithm to achieve a desirable NE of the original game. When this NE is achieved, the SUs obtain a Dhp-stable coalition structure and a fair transmit time allocation. Numerical results verify our analyses, and demonstrate the effectiveness of our algorithm.

  14. Spectrum correction algorithm for detectors in airborne radioactivity monitoring equipment NH-UAV based on a ratio processing method

    Cao, Ye; Tang, Xiao-Bin; Wang, Peng; Meng, Jia; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2015-01-01

    The unmanned aerial vehicle (UAV) radiation monitoring method plays an important role in nuclear accidents emergency. In this research, a spectrum correction algorithm about the UAV airborne radioactivity monitoring equipment NH-UAV was studied to measure the radioactive nuclides within a small area in real time and in a fixed place. The simulation spectra of the high-purity germanium (HPGe) detector and the lanthanum bromide (LaBr 3 ) detector in the equipment were obtained using the Monte Carlo technique. Spectrum correction coefficients were calculated after performing ratio processing techniques about the net peak areas between the double detectors on the detection spectrum of the LaBr 3 detector according to the accuracy of the detection spectrum of the HPGe detector. The relationship between the spectrum correction coefficient and the size of the source term was also investigated. A good linear relation exists between the spectrum correction coefficient and the corresponding energy (R 2 =0.9765). The maximum relative deviation from the real condition reduced from 1.65 to 0.035. The spectrum correction method was verified as feasible. - Highlights: • An airborne radioactivity monitoring equipment NH-UAV was developed to measure radionuclide after a nuclear accident. • A spectrum correction algorithm was proposed to obtain precise information on the detected radioactivity within a small area. • The spectrum correction method was verified as feasible. • The corresponding spectrum correction coefficients increase first and then stay constant

  15. Spectrum correction algorithm for detectors in airborne radioactivity monitoring equipment NH-UAV based on a ratio processing method

    Cao, Ye [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Tang, Xiao-Bin, E-mail: tangxiaobin@nuaa.edu.cn [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Wang, Peng; Meng, Jia; Huang, Xi; Wen, Liang-Sheng [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Chen, Da [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2015-10-11

    The unmanned aerial vehicle (UAV) radiation monitoring method plays an important role in nuclear accidents emergency. In this research, a spectrum correction algorithm about the UAV airborne radioactivity monitoring equipment NH-UAV was studied to measure the radioactive nuclides within a small area in real time and in a fixed place. The simulation spectra of the high-purity germanium (HPGe) detector and the lanthanum bromide (LaBr{sub 3}) detector in the equipment were obtained using the Monte Carlo technique. Spectrum correction coefficients were calculated after performing ratio processing techniques about the net peak areas between the double detectors on the detection spectrum of the LaBr{sub 3} detector according to the accuracy of the detection spectrum of the HPGe detector. The relationship between the spectrum correction coefficient and the size of the source term was also investigated. A good linear relation exists between the spectrum correction coefficient and the corresponding energy (R{sup 2}=0.9765). The maximum relative deviation from the real condition reduced from 1.65 to 0.035. The spectrum correction method was verified as feasible. - Highlights: • An airborne radioactivity monitoring equipment NH-UAV was developed to measure radionuclide after a nuclear accident. • A spectrum correction algorithm was proposed to obtain precise information on the detected radioactivity within a small area. • The spectrum correction method was verified as feasible. • The corresponding spectrum correction coefficients increase first and then stay constant.

  16. Medical management and planning for radiation emergencies

    Bongirwar, P.R.

    2001-01-01

    Radiation Emergencies which result as a consequence of nuclear or radiological accidents can produce a spectrum of different types of radiation injuries which could include cases of whole body irradiation causing Acute Radiation Syndrome, partial body irradiation, radiation burns (localized irradiation), radioactive contamination and combined injuries having component of conventional injuries. General principles of managing these cases entail doing triage, offering immediate emergency care and instituting definitive treatment. Infra-structural facilities which are required to facilitate their management include first aid post at plant site, personnel decontamination centre, site clinic and specialized hospital which can offer comprehensive investigational and treatment modalities. Training of medical and paramedical personnel is crucial as part of emergency preparedness programme and if needed, help can be sought from WHO's Radiation Emergency Medical Preparedness and Assistance Network Centres. (author)

  17. Radiation damping in focusing-dominated systems

    Huang, Zhirong; Chen, Pisin; Ruth, R.D.

    1995-01-01

    A quasi-classical method is developed to calculate the radiation damping of a relativistic particle in a straight, continuous focusing system. In one limiting case where the pitch angle of the particle θ p is much larger than the radiation opening angle 1/γ, the radiation power spectrum is similar to synchrotron radiation and the relative damping rate of the transverse action is proportional to the relative energy loss rate. In the other limiting case where θ p much-lt 1/γ, the radiation is dipole in nature and the relative damping rate of the transverse action is energy-independent and is much faster than the relative energy rate. Quantum excitation to the transverse action is absent in this focusing channel. These results can be extended to bent systems provided that the focusing field dominates over the bending field

  18. Radiation therapy sources, equipment and installations

    2011-03-01

    The safety code for Telegamma Therapy Equipment and Installations, (AERB/SC/MED-1) and safety code for Brachytherapy Sources, Equipment and Installations, (AERB/SC/MED-3) were issued by AERB in 1986 and 1988 respectively. These codes specified mandatory requirements for radiation therapy facilities, covering the entire spectrum of operations ranging from the setting up of a facility to its ultimate decommissioning, including procedures to be followed during emergency situations. The codes also stipulated requirements of personnel and their responsibilities. With the advent of new techniques and equipment such as 3D-conformal radiation therapy, intensity modulated radiation therapy, image guided radiation therapy, treatment planning system, stereotactic radiosurgery, stereotactic radiotherapy, portal imaging, integrated brachytherapy and endovascular brachytherapy during the last two decades, AERB desires that these codes be revised and merged into a single code titled Radiation Therapy Sources, Equipment, and Installations

  19. Avoidable cancers in the Nordic countries. Radiation

    Winther, J F; Ulbak, Kaare; Dreyer, L

    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...... 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...... 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...

  20. Study of the gamma radiation of ionium

    Curie, I

    1949-12-01

    A Geiger counter study has been made of the ..gamma.. radiation of ionium. Eleven quanta of the L radiation of radium were observed for every hundred ..cap alpha.. disintegrations, and three ..gamma.. rays were found with energies of 68, 140, and 240 keV at a rate of 0.85, 0.33, 0.05 quanta, respectively, for 100 disintegrations. It is noted that the radiation spectrum of ionium as a whole is difficult to interpret. In the course of this work, the author calculated the efficiency of a thin-walled aluminum counter, both for the L radiation of radium and for ..gamma.. rays of 68 keV. The author also measured, for soft radiation, the ratio between the efficiency of a thin-walled aluminum counter and that of a similar counter lined with 0.11 mm of lead.