Composition of cosmic rays in the knee region of the primary energy spectrum

International Nuclear Information System (INIS)

Das Gupta, U.

1989-01-01

The Soudan Surface-Underground Cosmic Ray Telescope is located at the Soudan iron mine in northern Minnesota. It consists of a coincidence arrangement of two detectors-one installed at the surface of the mine and the other located underground, at a vertical depth of 600 meters. Using such an arrangement, the energy and composition of a primary cosmic ray particle can be determined independently of one another. When a high energy cosmic ray enters the Earth's atmosphere, secondary particles are produced in successive interactions, creating an extensive air shower. Using the surface detector, the number of particles in the shower at the surface of the Earth can be counted and the energy of the primary particle estimated. Of all the particles that are created in a cosmic ray air shower, only the energetic muons are able to penetrate underground. The separations of the muons below ground are measured by the Soudan 1 detector and this serves as an indicator of the type of nucleus that initiated the shower. The Soudan surface-underground detector is sensitive to primary cosmic rays of energies between 10 14 and 10 18 eV. The data from the experiment were compared to the predictions of various cosmic ray composition models, within this energy range. The data supported a composition model that was proton dominated up to the highest energies measured. There was no indication of a shift in the composition towards heavier primaries as would be expected on the basis of some models

Primary CR energy spectrum and mass composition by the data of Tunka-133 array

Directory of Open Access Journals (Sweden)

Prosin V.V.

2015-01-01

Full Text Available The Cherenkov light array for the registration of extensive air showers (EAS Tunka-133 collected data during 5 winter seasons from 2009 to 2014. The differential energy spectrum of all particles and the dependence of the average maximum depth on the energy in the range of 6 ⋅ 1015–1018 eV measured for 1540 hours of observation are presented.

Energy spectrum of buoyancy-driven turbulence

KAUST Repository

Kumar, Abhishek; Chatterjee, Anando G.; Verma, Mahendra K.

2014-01-01

Using high-resolution direct numerical simulation and arguments based on the kinetic energy flux Πu, we demonstrate that, for stably stratified flows, the kinetic energy spectrum Eu(k)∼k-11/5, the potential energy spectrum Eθ(k)∼k-7/5, and Πu(k)∼k-4

Bose-type distribution and primary cosmic ray nucleon spectrum from sea-level muon spectrum

CERN Document Server

Bhattacharya, D P; Roychowdhury, R K

1976-01-01

The recent CERN Intersecting Storage Ring cross section data on the p +p to pi /sup +or-/+X inclusive reactions have been analysed using the Bose-type distribution of the form E(d/sup 3/ sigma )/(d/sup 3/p)=(Axs /sup 1/2/)/(exp( epsilon ( lambda )/T)-1) proposed by Hoang (1973). This formula has been used to derive the cosmic ray primary nucleon spectrum from the sea-level muon spectrum. It is found that the primary spectrum obeys the following relation: N(E/sub p/)dE/sub p /=2.06E/sub p//sup -2.64/dE/sub p/. The result has been compared with the recent experimental data and theoretical predictions given by different authors. (11 refs).

Energy spectrum of buoyancy-driven turbulence

KAUST Repository

Kumar, Abhishek

2014-08-25

Using high-resolution direct numerical simulation and arguments based on the kinetic energy flux Πu, we demonstrate that, for stably stratified flows, the kinetic energy spectrum Eu(k)∼k-11/5, the potential energy spectrum Eθ(k)∼k-7/5, and Πu(k)∼k-4/5 are consistent with the Bolgiano-Obukhov scaling. This scaling arises due to the conversion of kinetic energy to the potential energy by buoyancy. For weaker buoyancy, this conversion is weak, hence Eu(k) follows Kolmogorov\\'s spectrum with a constant energy flux. For Rayleigh-Bénard convection, we show that the energy supply rate by buoyancy is positive, which leads to an increasing Πu(k) with k, thus ruling out Bolgiano-Obukhov scaling for the convective turbulence. Our numerical results show that convective turbulence for unit Prandt number exhibits a constant Πu(k) and Eu(k)∼k-5/3 for a narrow band of wave numbers. © 2014 American Physical Society.

Analytical energy spectrum for hybrid mechanical systems

International Nuclear Information System (INIS)

Zhong, Honghua; Xie, Qiongtao; Lee, Chaohong; Guan, Xiwen; Gao, Kelin; Batchelor, Murray T

2014-01-01

We investigate the energy spectrum for hybrid mechanical systems described by non-parity-symmetric quantum Rabi models. A set of analytical solutions in terms of the confluent Heun functions and their analytical energy spectrum is obtained. The analytical energy spectrum includes regular and exceptional parts, which are both confirmed by direct numerical simulation. The regular part is determined by the zeros of the Wronskian for a pair of analytical solutions. The exceptional part is relevant to the isolated exact solutions and its energy eigenvalues are obtained by analyzing the truncation conditions for the confluent Heun functions. By analyzing the energy eigenvalues for exceptional points, we obtain the analytical conditions for the energy-level crossings, which correspond to two-fold energy degeneracy. (paper)

Calculation of the energy spectrum of atmospheric gamma-rays between 1 and 1000 MeV

International Nuclear Information System (INIS)

Martin, I.M.; Dutra, S.L.G.; Palmeira, R.A.R.

The energy spectrum of atmospheric gamma-rays at 4 g/cm 2 has been calculated for cut-off rigidities of 4.5, 10 and 16 GV. The considered processes for the production of these gamma-rays were the π 0 decay plus the bremsstrahlung from primary, secondary like splash and re-entrant albedo electrons. The calculations indicated that the spectrum could be fitted to a power law in energy, with the exponential index varying from 1.1 in the energy range 1 - 10 MeV, to 1.4 in the energy range 10 - 200 MeV and 1.8 in the energy range 200 - 1000 MeV. These results are discussed [pt

Energy spectrum of primary cosmic rays from 1016eV to 1019eV determined from air showers observed at 5200 m a.s.l

International Nuclear Information System (INIS)

Aguirre, C.; Mejia, G.R.; Yoshii, H.; Toyoda, Y.

1977-01-01

Energy spectra of primary cosmic rays from 10 16 eV to 10 19 eV have been determined from electron-sizes as well as from muon-sizes of the same air showers observed at Mt. Chacaltaya. The spectrum from electron-sizes is significantly higher than that from muon-sizes. The discrepancy is discussed and an explanation is given under the assumption of possible existence of copious direct production of photons besides the production of charged and neutral pions at these high energies. The spectra are also compared with those by other groups and the discrepancies are discussed. (author)

Energy efficient cross layer design for spectrum sharing systems

KAUST Repository

Alabbasi, Abdulrahman

2016-10-06

We propose a cross layer design that optimizes the energy efficiency of spectrum sharing systems. The energy per good bit (EPG) is considered as an energy efficiency metric. We optimize the secondary user\\'s transmission power and media access frame length to minimize the EPG metric. We protect the primary user transmission via an outage probability constraint. The non-convex targeted problem is optimized by utilizing the generalized convexity theory and verifying the strictly pseudo-convex structure of the problem. Analytical results of the optimal power and frame length are derived. We also used these results in proposing an algorithm, which guarantees the existence of a global optimal solution. Selected numerical results show the improvement of the proposed system compared to other systems. © 2016 IEEE.

Measurement of the energy spectrum of cosmic rays with the 26 station configuration of the IceTop detector

International Nuclear Information System (INIS)

Kislat, Fabian

2011-01-01

IceTop is an instrument at the geographic South Pole designed to detect cosmic ray air showers, particle cascades in the atmosphere initiated by high-energy cosmic rays. It is the surface component of the IceCube neutrino telescope. Since its completion in December 2010, IceTop consists of 81 detector stations covering an area of one square kilometer on the ice surface above IceCube. Each IceTop station consists of two ice-filled tanks in which the Cherenkov light emitted by charged air shower particles is measured. In this dissertation, an analysis of data taken in 2007 with 26 IceTop stations operational at that time is presented. First, properties of air showers like core position, direction and shower size were reconstructed from the measured signals. The core position can be determined to an accuracy of up to 6m and a direction resolution of up to 0.3 is achieved. The shower size is a measure of the energy of the primary particle and a resolution of up to 10% is achieved at high energies. In the next step the relation between primary energy and shower size, as well as resolution and efficiency are determined from Monte Carlo simulations of air showers and the IceTop detector. Here, an assumption was made about the chemical composition of cosmic rays. The informations obtained in these simulations are then used to unfold the spectrum of measured shower sizes in order to obtain the all-particle cosmic ray energy spectrum. This is done independently for particles from three different zenith angle intervals. The result of the unfolding depends on the assumed primary composition. Due to the isotropy of cosmic rays, results obtained in different zenith angle intervals must agree. While with the chosen analysis technique a simultaneous determination of primary particle mass and energy is limited due to systematic uncertainties, it has already been shown that the requirement of isotropy can be used to constrain the range of possible assumptions on the chemical

Measurement of the energy spectrum of cosmic rays with the 26 station configuration of the IceTop detector

Energy Technology Data Exchange (ETDEWEB)

Kislat, Fabian

2011-09-27

IceTop is an instrument at the geographic South Pole designed to detect cosmic ray air showers, particle cascades in the atmosphere initiated by high-energy cosmic rays. It is the surface component of the IceCube neutrino telescope. Since its completion in December 2010, IceTop consists of 81 detector stations covering an area of one square kilometer on the ice surface above IceCube. Each IceTop station consists of two ice-filled tanks in which the Cherenkov light emitted by charged air shower particles is measured. In this dissertation, an analysis of data taken in 2007 with 26 IceTop stations operational at that time is presented. First, properties of air showers like core position, direction and shower size were reconstructed from the measured signals. The core position can be determined to an accuracy of up to 6m and a direction resolution of up to 0.3 is achieved. The shower size is a measure of the energy of the primary particle and a resolution of up to 10% is achieved at high energies. In the next step the relation between primary energy and shower size, as well as resolution and efficiency are determined from Monte Carlo simulations of air showers and the IceTop detector. Here, an assumption was made about the chemical composition of cosmic rays. The informations obtained in these simulations are then used to unfold the spectrum of measured shower sizes in order to obtain the all-particle cosmic ray energy spectrum. This is done independently for particles from three different zenith angle intervals. The result of the unfolding depends on the assumed primary composition. Due to the isotropy of cosmic rays, results obtained in different zenith angle intervals must agree. While with the chosen analysis technique a simultaneous determination of primary particle mass and energy is limited due to systematic uncertainties, it has already been shown that the requirement of isotropy can be used to constrain the range of possible assumptions on the chemical

Method to deduce the energy spectrum by the Pierre Auger Observatory

Energy Technology Data Exchange (ETDEWEB)

Maris, I.; Roth, M.; Schmidt, T.; Schuessler, F.; Unger, M. [Univ. Karlsruhe (Germany); Bluemer, J. [Univ. Karlsruhe (Germany); Forschungszentrum Karlsruhe (Germany)

2007-07-01

Taken into account the great advantage of having a hybrid detector it has been developed a method, simulation independent, to determine the energy of the comic rays recorded by the surface detector of the Pierre Auger Observatory. The method assumes that the cosmic ray flux has the same distribution in zenith angle for all energy ranges. Therefore one can relate the calorimetric measurement of the fluorescence detector of the CR energy with a SD quantity, e.g. shower size at 1000m distance from the core, corrected for the different attenuations in the atmosphere. The method of measuring and calibrating the primary energy and the influence of reconstruction uncertainties on the energy spectrum are presented. (orig.)

A Multi-Antenna Framework for Spectrum Reuse Based on Primary-Secondary Cooperation

KAUST Repository

Bakr, Omar; Johnson, Mark; Wild, Ben; Ramchandran, Kannan

2008-01-01

This paper proposes a new framework for spectrum reuse. Existing architectures have centered on secondary users (cognitive radios) that can reliably sense primary users and opportunistically transmit, without directly interacting with the primary system. We present a paradigm in which the primary and secondary systems cooperate, to minimize interference to primary users and provide predictable access for secondary users. Because this architecture gives the primary system full control over spectrum sharing, it could be more favorable in the current economic and political environment. We illustrate a concrete instance of our framework by showing how secondary radios can reuse the entire uplink channel of a cellular network, with only modest changes to the primary infrastructure. ©2008 IEEE.

A Multi-Antenna Framework for Spectrum Reuse Based on Primary-Secondary Cooperation

KAUST Repository

Bakr, Omar

2008-10-01

This paper proposes a new framework for spectrum reuse. Existing architectures have centered on secondary users (cognitive radios) that can reliably sense primary users and opportunistically transmit, without directly interacting with the primary system. We present a paradigm in which the primary and secondary systems cooperate, to minimize interference to primary users and provide predictable access for secondary users. Because this architecture gives the primary system full control over spectrum sharing, it could be more favorable in the current economic and political environment. We illustrate a concrete instance of our framework by showing how secondary radios can reuse the entire uplink channel of a cellular network, with only modest changes to the primary infrastructure. ©2008 IEEE.

Dynamic energy spectrum and energy deposition in solid target by intense pulsed ion beams

Institute of Scientific and Technical Information of China (English)

Xiao Yu; Xiao-Yun Le; Zheng Liu; Jie Shen; Yu I.Isakova; Hao-Wen Zhong; Jie Zhang; Sha Yan; Gao-Long Zhang; Xiao-Fu Zhang

2017-01-01

A method for analyzing the dynamic energy spectrum of intense pulsed ion beam (IPIB) was proposed.Its influence on beam energy deposition in metal target was studied with IPIB produced by two types of magnetically insulated diodes (MID).The emission of IPIB was described with space charge limitation model,and the dynamic energy spectrum was further analyzed with time-of-flight method.IPIBs generated by pulsed accelerators of BIPPAB-450 (active MID) and TEMP-4M (passive MID) were studied.The dynamic energy spectrum was used to deduce the power density distribution of IPIB in the target with Monte Carlo simulation and infrared imaging diagnostics.The effect on the distribution and evolution of thermal field induced by the characteristics of IPIB dynamic energy spectrum was discussed.

Subclinical primary retinal pathology in neuromyelitis optica spectrum disorder.

Science.gov (United States)

Jeong, In Hye; Kim, Ho Jin; Kim, Nam-Hee; Jeong, Kyoung Sook; Park, Choul Yong

2016-07-01

Foveal thickness may be a more sensitive indicator of primary retinal pathology than retinal nerve fiber layer thickness since the fovea contains no or sparse retinal nerve fiber layer, which coalesces into axons of the optic nerve. To our knowledge, few quantitative in vivo studies have investigated foveal thickness. By using optical coherence tomography, we measured foveal thickness to evaluate intrinsic retinal pathology. Seventy-two neuromyelitis optica spectrum disorder patients (99 eyes with optic neuritis and 45 eyes without optic neuritis) and 34 age-matched controls were included. Foveal thinning was observed both in eyes with non-optic neuritis (185.1 µm, p optica spectrum disorder, foveal thickness correlated with 2.5 % low contrast visual acuity, while retinal nerve fiber layer thickness correlated with high or low contrast visual acuity, extended disability status scale, and disease duration. In this study, we observed foveal thinning irrespective of optic neuritis; thus, we believe that subclinical primary retinal pathology, prior to retinal nerve fiber layer thinning, may exist in neuromyelitis optica spectrum disorder.

Electron energy spectrum in core-shell elliptic quantum wire

Directory of Open Access Journals (Sweden)

V.Holovatsky

2007-01-01

Full Text Available The electron energy spectrum in core-shell elliptic quantum wire and elliptic semiconductor nanotubes are investigated within the effective mass approximation. The solution of Schrodinger equation based on the Mathieu functions is obtained in elliptic coordinates. The dependencies of the electron size quantization spectrum on the size and shape of the core-shell nanowire and nanotube are calculated. It is shown that the ellipticity of a quantum wire leads to break of degeneration of quasiparticle energy spectrum. The dependences of the energy of odd and even electron states on the ratio between semiaxes are of a nonmonotonous character. The anticrosing effects are observed at the dependencies of electron energy spectrum on the transversal size of the core-shell nanowire.

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

International Nuclear Information System (INIS)

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)

THE COSMIC-RAY ENERGY SPECTRUM OBSERVED WITH THE SURFACE DETECTOR OF THE TELESCOPE ARRAY EXPERIMENT

Energy Technology Data Exchange (ETDEWEB)

Abu-Zayyad, T.; Allen, M.; Anderson, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Hanlon, W. [High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah (United States); Aida, R. [University of Yamanashi, Interdisciplinary Graduate School of Medicine and Engineering, Kofu, Yamanashi (Japan); Azuma, R.; Fukuda, T. [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo (Japan); Cheon, B. G.; Cho, E. J. [Department of Physics and Research Institute of Natural Science, Hanyang University, Seongdong-gu, Seoul (Korea, Republic of); Chiba, J. [Department of Physics, Tokyo University of Science, Noda, Chiba (Japan); Chikawa, M. [Department of Physics, Kinki University, Higashi Osaka, Osaka (Japan); Cho, W. R. [Department of Physics, Yonsei University, Seodaemun-gu, Seoul (Korea, Republic of); Fujii, H. [Institute of Particle and Nuclear Studies, KEK, Tsukuba, Ibaraki (Japan); Fujii, T. [Graduate School of Science, Osaka City University, Osaka, Osaka (Japan); Fukushima, M. [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba (Japan); and others

2013-05-01

The Telescope Array (TA) collaboration has measured the energy spectrum of ultra-high energy cosmic rays (UHECRs) with primary energies above 1.6 Multiplication-Sign 10{sup 18} eV. This measurement is based upon four years of observation by the surface detector component of TA. The spectrum shows a dip at an energy of 4.6 Multiplication-Sign 10{sup 18} eV and a steepening at 5.4 Multiplication-Sign 10{sup 19} eV which is consistent with the expectation from the GZK cutoff. We present the results of a technique, new to the analysis of UHECR surface detector data, that involves generating a complete simulation of UHECRs striking the TA surface detector. The procedure starts with shower simulations using the CORSIKA Monte Carlo program where we have solved the problems caused by use of the ''thinning'' approximation. This simulation method allows us to make an accurate calculation of the acceptance of the detector for the energies concerned.

Energy spectrum control for modulated proton beams

International Nuclear Information System (INIS)

Hsi, Wen C.; Moyers, Michael F.; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E.; Farr, Jonathan B.; Mascia, Anthony E.; Schreuder, Andries N.

2009-01-01

In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to ±21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than ±3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies.

The energy spectrum of 662 keV photons in a water equivalent phantom

International Nuclear Information System (INIS)

Akar Tarim, U.; Gurler, O.; Ozmutlu, E.N.; Yalcin, S.; Gundogdu, O.; Sharaf, J.M.; Bradley, D.A.

2012-01-01

Investigation is made on the energy spectrum of photons originating from interactions of 662 keV primary gamma-ray photons emitted by a point source positioned at the centre of a water equivalent solid phantom of dimensions 19 cm×19 cm×24 cm. Peaks resulting from total energy loss (photopeak) and multiple and back scattering have been observed using a 51 mm×51 mm NaI(Tl) detector; good agreement being found between the measured and simulated response functions. The energy spectrum of the gamma photons obtained through the Monte Carlo simulation reveals local maxima at about 100 keV and 210 keV, being also observed in the experimental response function. Such spectra can be used as a method of testing the water equivalence of solid phantom media before their use for dosimetry measurements. - Highlights: ► Peaks resulting from total energy loss (photopeak) and multiple and back scattering were observed. ► Energy distribution of γ-ray photons from a point source at the centre of a water equivalent solid phantom. ► The method can be applied to various detector geometries.

[Study of spectrum drifting of primary colors and its impact on color rendering properties].

Science.gov (United States)

Cui, Xiao-yan; Zhang, Xiao-dong

2012-08-01

LEDs are currently used widely to display text, graphics and images in large screens. With red, green and blue LEDs as three primary colors, color rendition will be realized through color mixing. However, LEDs' spectrum will produce drifts with the changes in the temperature environment. With the changes in the driving current simulating changes in the temperature, the three primary color LEDs' spectral drifts were tested, and the drift characteristics of the three primary colors were obtained respectively. Based on the typical characteristics of the LEDs and the differences between LEDs with different colors in composition and molecular structure, the paper analyzed the reason for the spectrum drifts and the drift characteristics of different color LEDs, and proposed the equations of spectrum drifts. Putting the experimental data into the spectrum drift equations, the paper analyzed the impacts of primary colors on the mixed color, pointed out a way to reduce the chromatic aberration, and provided the theory for engineering application of color LEDs.

Measurement of Neutron Energy Spectrum Emitted by Cf-252 Source Using Time-of-Flight Method

Energy Technology Data Exchange (ETDEWEB)

Lee, Cheol Ho; Son, Jaebum; Kim, Tae Hoon; Lee, Sangmin; Kim, Yong-Kyun [Hanyang University, Seoul (Korea, Republic of)

2016-10-15

The techniques proposed to detect the neutrons usually require the detection of a secondary recoiling nucleus in a scintillator (or other type of detector) to indicate the rare collision of a neutron with a nucleus. This is the same basic technique, in this case detection of a recoil proton that was used by Chadwick in the 1930 s to discover and identify the neutron and determine its mass. It is primary technique still used today for detection of fast neutron, which typically involves the use of a hydrogen based organic plastic or liquid scintillator coupled to a photo-multiplier tube. The light output from such scintillators is a function of the cross section and nuclear kinematics of the n + nucleus collision. With the exception of deuterated scintillators, the scintillator signal does not necessarily produce a distinct peak in the scintillator spectrum directly related to the incident neutron energy. Instead neutron time-of-flight (TOF) often must be utilized to determine the neutron energy, which requires generation of a prompt start signal from the nuclear source emitting the neutrons. This method takes advantage of the high number of prompt gamma rays. The Time-of-Flight method was used to measure neutron energy spectrum emitted by the Cf-252 neutron source. Plastic scintillator that has a superior discrimination ability of neutron and gamma-ray was used as a stop signal detector and liquid scintillator was used as a stat signal detector. In experiment, neutron and gamma-ray spectrum was firstly measured and discriminated using the TOF method. Secondly, neutron energy spectrum was obtained through spectrum analysis. Equation of neutron energy spectrum that was emitted by Cf-252 source using the Gaussian fitting was obtained.

Measurement of the transverse energy spectrum in proton-nucleon collisions

International Nuclear Information System (INIS)

Bettoni, D.

1988-01-01

The author describes a measurement of the transverse energy spectrum in proton-nucleon interactions carried out at the CERN SPS using the HELIOS spectrometer. The measurement is of particular interest in that it is performed in a rapidity region away from central rapidity, where experimental data is scarce. In this rapidity region very interesting physics is anticipated and the measurement of the proton-nucleon collisions is essential as a basis to understand the more complicated proton-nucleus and nucleus-nucleus interactions. Both these topics are part of the experimental program of HELIOS. The measurement was done using a deuterium target enclosed in an iron tube. The contribution to the transverse energy spectrum from the p-Fe events is discriminated against by reconstructing the primary interaction vertex using drift chamber information. The measured spectrum is corrected via Monte Carlo to deconvolute the effect of reinteractions. High spatial resolution and multi-track resolving power are achieved with the use of a cool gas, such that the electron characteristic energy is close to the thermal limit: this implies a small diffusion coefficient and a consequently good positional accuracy. Of vital importance are the low value of the drift velocity, the fast, differentiating electronics and a careful shaping of the electric field configuration to improve the isochrony of the drift collection. The author reports on the design and tests of drift chamber prototypes built along the above lines, with which a spatial accuracy of 0.06 mm and a double track resolution of 0.6 mm were measured. He also describes the final drift chamber system and its operation in HELIOS

Interference Energy Spectrum of the Infinite Square Well

Directory of Open Access Journals (Sweden)

Mordecai Waegell

2016-04-01

Full Text Available Certain superposition states of the 1-D infinite square well have transient zeros at locations other than the nodes of the eigenstates that comprise them. It is shown that if an infinite potential barrier is suddenly raised at some or all of these zeros, the well can be split into multiple adjacent infinite square wells without affecting the wavefunction. This effects a change of the energy eigenbasis of the state to a basis that does not commute with the original, and a subsequent measurement of the energy now reveals a completely different spectrum, which we call the interference energy spectrum of the state. This name is appropriate because the same splitting procedure applied at the stationary nodes of any eigenstate does not change the measurable energy of the state. Of particular interest, this procedure can result in measurable energies that are greater than the energy of the highest mode in the original superposition, raising questions about the conservation of energy akin to those that have been raised in the study of superoscillations. An analytic derivation is given for the interference spectrum of a given wavefunction Ψ ( x , t with N known zeros located at points s i = ( x i , t i . Numerical simulations were used to verify that a barrier can be rapidly raised at a zero of the wavefunction without significantly affecting it. The interpretation of this result with respect to the conservation of energy and the energy-time uncertainty relation is discussed, and the idea of alternate energy eigenbases is fleshed out. The question of whether or not a preferred discrete energy spectrum is an inherent feature of a particle’s quantum state is examined.

All-particle cosmic ray energy spectrum measured by the HAWC experiment from 10 to 500 TeV

Science.gov (United States)

Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Avila Rojas, D.; Ayala Solares, H. A.; Barber, A. S.; Becerril, A.; Belmont-Moreno, E.; BenZvi, S. Y.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; Coutiño de León, S.; De León, C.; De la Fuente, E.; Diaz Hernandez, R.; Dichiara, S.; Dingus, B. L.; DuVernois, M. A.; Díaz-Vélez, J. C.; Ellsworth, R. W.; Enriquez-Rivera, O.; Fiorino, D. W.; Fleischhack, H.; Fraija, N.; García-González, J. A.; González Muñoz, A.; González, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez-Almada, A.; Hinton, J.; Hueyotl-Zahuantitla, F.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Lara, A.; Lauer, R. J.; Lennarz, D.; León Vargas, H.; Linnemann, J. T.; Longinotti, A. L.; Luis Raya, G.; Luna-García, R.; López-Cámara, D.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pelayo, R.; Pretz, J.; Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wood, J.; Yapici, T.; Zepeda, A.; Zhou, H.; HAWC Collaboration

2017-12-01

We report on the measurement of the all-particle cosmic ray energy spectrum with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range 10 to 500 TeV. HAWC is a ground-based air-shower array deployed on the slopes of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to gamma rays and cosmic rays at TeV energies. The data used in this work were taken over 234 days between June 2016 and February 2017. The primary cosmic-ray energy is determined with a maximum likelihood approach using the particle density as a function of distance to the shower core. Introducing quality cuts to isolate events with shower cores landing on the array, the reconstructed energy distribution is unfolded iteratively. The measured all-particle spectrum is consistent with a broken power law with an index of -2.49 ±0.01 prior to a break at (45.7 ±0.1 ) TeV , followed by an index of -2.71 ±0.01 . The spectrum also represents a single measurement that spans the energy range between direct detection and ground-based experiments. As a verification of the detector response, the energy scale and angular resolution are validated by observation of the cosmic ray Moon shadow's dependence on energy.

Specific features of energy and spatial distribution of primary knocked-out atoms in monocrystals

International Nuclear Information System (INIS)

Taratin, A.M.; Vorob'ev, S.A.

1978-01-01

By simulation trajectories of 0.2 MeV protons in 1 μm thick Al monocrystal, the energy and spatial distributions of primary atoms knocked out by the protons (PKA) have been studied. Different orientations of the incident beam axis relative to the densely packed direction in the case of ''quasichanneling'' and ''chaotic'' scattering of particles by the crystal have been researched. The depth dependence of the number of generated PKA, their distribution in the plane transverse to the preferred direction, and the energy spectrum of PKA have been obtained. It is shown that the PKA volume density is higher than that obtained using evaluations not accounting for the crystalline structure, and the energy spectrum contains more low energy PKAs. A concept of the cross section of the PKA production on an atomic chain is introduced for ipterpretation of the data obtained

Comparing primary energy attributed to renewable energy with primary energy equivalent to determine carbon abatement in a national context.

Science.gov (United States)

Gallachóir, Brian P O; O'Leary, Fergal; Bazilian, Morgan; Howley, Martin; McKeogh, Eamon J

2006-01-01

The current conventional approach to determining the primary energy associated with non-combustible renewable energy (RE) sources such as wind energy and hydro power is to equate the electricity generated from these sources with the primary energy supply. This paper compares this with an approach that was formerly used by the IEA, in which the primary energy equivalent attributed to renewable energy was equated with the fossil fuel energy it displaces. Difficulties with implementing this approach in a meaningful way for international comparisons lead to most international organisations abandoning the primary energy equivalent methodology. It has recently re-emerged in prominence however, as efforts grow to develop baseline procedures for quantifying the greenhouse gas (GHG) emissions avoided by renewable energy within the context of the Kyoto Protocol credit trading mechanisms. This paper discusses the primary energy equivalent approach and in particular the distinctions between displacing fossil fuel energy in existing plant or in new plant. The approach is then extended provide insight into future primary energy displacement by renewable energy and to quantify the amount of CO2 emissions avoided by renewable energy. The usefulness of this approach in quantifying the benefits of renewable energy is also discussed in an energy policy context, with regard to increasing security of energy supply as well as reducing energy-related GHG (and other) emissions. The approach is applied in a national context and Ireland is case study country selected for this research. The choice of Ireland is interesting in two respects. The first relates to the high proportion of electricity only fossil fuel plants in Ireland resulting in a significant variation between primary energy and primary energy equivalent. The second concerns Ireland's poor performance to date in limiting GHG emissions in line with its Kyoto target and points to the need for techniques to quantify the potential

Full Spectrum Diffused and Beamed Solar Energy Application Using Optical Fibre

OpenAIRE

Majumdar, M. R. Dutta; Das, Debasish

2007-01-01

Existing solar energy application systems use small fraction of full spectrum of solar energy. So attempts are made to show how full spectrum solar energy can be used for diffused and beamed form of incident solar energy. Luminescent Solar Concentrator (LSC) principle with optical fibre in diffused sun light and dielectric mirror separation technique with optical fibre in beamed form are discussed. Comparison of both the cases are done. Keywords: full spectrum, solar photonics, diffused solar...

Influence of hadronic interaction models and the cosmic ray spectrum on the high energy atmospheric muon and neutrino flux

OpenAIRE

Fedynitch, Anatoli; Tjus, Julia Becker; Desiati, Paolo

2012-01-01

The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic ray induced extensive air showers is carried out with a primary cosmic ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to...

Evaluation of the Neutron Detector Response for Cosmic Ray Energy Spectrum by Monte Carlo Transport Simulation

International Nuclear Information System (INIS)

Pazianotto, Mauricio T.; Carlson, Brett V.; Federico, Claudio A.; Gonzalez, Odair L.

2011-01-01

Neutrons generated by the interaction of cosmic rays with the atmosphere make an important contribution to the dose accumulated in electronic circuits and aircraft crew members at flight altitude. High-energy neutrons are produced in spallation reactions and intranuclear cascade processes by primary cosmic-ray particle interactions with atoms in the atmosphere. These neutrons can produce secondary neutrons and also undergo a moderation process due to atmosphere interactions, resulting in a wider energy spectrum, ranging from thermal energies (0.025 eV) to energies of several hundreds of MeV. The Long-Counter (LC) detector is a widely used neutron detector designed to measure the directional flux of neutrons with about constant response over a wide energy range (thermal to 20 MeV). ). Its calibration process and the determination of its energy response for the wide-energy of cosmic ray induced neutron spectrum is a very difficult process due to the lack of installations with these capabilities. The goal of this study is to assess the behavior of the response of a Long Counter using the Monte Carlo (MC) computational code MCNPX (Monte Carlo N-Particle eXtended). The dependence of the Long Counter response on the angle of incidence, as well as on the neutron energy, will be carefully investigated, compared with the experimental data previously obtained with 241 Am-Be and 252 Cf neutron sources and extended to the neutron spectrum produced by cosmic rays. (Author)

Influence of hadronic interaction models and the cosmic ray spectrum on the high-energy atmospheric muon and neutrino flux

Directory of Open Access Journals (Sweden)

Desiati Paolo

2013-06-01

Full Text Available The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic ray induced extensive air showers is carried out with a primary cosmic ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to derive the inclusive differential spectra (yields of muons, muon neutrinos and electron neutrinos at the surface for energies between 80 GeV and hundreds of PeV. Using these results the differential flux and the flavor ratios of leptons were calculated. The air shower simulator CORSIKA 6.990 was used for showering and propagation of the secondary particles through the atmosphere, employing the established high energy hadronic interaction models SIBYLL 2.1, QGSJet-01 and QGSJet-II-03. We show that the performance of the interaction models allows makes it possible to predict the spectra within experimental uncertainties, while SIBYLL generally yields a higher flux at the surface than the QGSJet models. The calculation of the flavor and charge ratios has lead to inconsistent results, mainly influenced by the different representations of the K/π ratio within the models. The influence of the knee of cosmic rays is reflected in the secondary spectra at energies between 100 and 200 TeV. Furthermore, we could quantify systematic uncertainties of atmospheric muon- and neutrino fluxes, associated to the models of the primary cosmic ray spectrum and the interaction models. For most recent parametrizations of the cosmic ray primary spectrum, atmospheric muons can be determined with an uncertainty smaller than +15/-13% of the average flux. Uncertainties of the muon and electron neutrino fluxes can be calculated within an average error of +32/-22% and +25

Higher frequency of brain abnormalities in neuromyelitis optica spectrum disorder patients without primary Sjögren's syndrome.

Science.gov (United States)

Gu, Li-Na; Zhang, Min; Zhu, Hui; Liu, Jing-Yao

2016-10-01

Neuromyelitis optica spectrum disorder often co-exists with primary Sjögren's syndrome. We compared the clinical features of 16 neuromyelitis optica spectrum disorder patients with ( n = 6) or without primary Sjögren's syndrome ( n = 10). All patients underwent extensive clinical, laboratory, and MRI evaluations. There were no statistical differences in demographics or first neurological involvement at onset between neuromyelitis optica spectrum disorder patients with and without primary Sjögren's syndrome. The laboratory findings of cerebrospinal fluid oligoclonal banding, serum C-reactive protein, antinuclear autoantibody, anti-Sjögren's-syndrome-related antigen A antibodies, anti-Sjögren's-syndrome-related antigen B antibodies, and anti-Sm antibodies were significantly higher in patients with primary Sjögren's syndrome than those without. Anti-aquaporin 4 antibodies were detectable in 67% (4/6) of patients with primary Sjögren's syndrome and in 60% (6/10) of patients without primary Sjögren's syndrome. More brain abnormalities were observed in patients without primary Sjögren's syndrome than in those with primary Sjögren's syndrome. Segments lesions (> 3 centrum) were noted in 50% (5/10) of patients without primary Sjögren's syndrome and in 67% (4/6) of patients with primary Sjögren's syndrome. These findings indicate that the clinical characteristics of neuromyelitis optica spectrum disorder patients with and without primary Sjögren's syndrome are similar. However, neuromyelitis optica spectrum disorder patients without primary Sjögren's syndrome have a high frequency of brain abnormalities.

Radiation damage in materials. Primary knock-on atom energy analyses of cascade damage

International Nuclear Information System (INIS)

Sekimura, Naoto

1995-01-01

To understand cascade damage formation as a function of primary recoil energy, thin foils of gold were irradiated with 20 - 400 keV self-ions to 1.0 x 10 14 ions/m 2 at 300 K. Yield of groups of vacancy clusters saturated at ion energy higher than 100 keV. Number of clusters in a group had variation even from the same energy ions. Size distribution of the clusters was not strongly dependent on number of clusters in a group and ion energy. Density of vacancy clusters in a group formed near the specimen surface was calibrated to estimate vacancy cluster formation in neutron-irradiated material. A model was proposed to predict distribution of defect clusters in the irradiated materials based on a primary recoil spectrum. Examples of recomposed distribution of vacancy clusters in a group in irradiated gold were compared with the measured data. (author)

Energy spectrum of lightning gamma emission

Energy Technology Data Exchange (ETDEWEB)

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.

Energy spectrum of lightning gamma emission

International Nuclear Information System (INIS)

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.

Measuring extensive air showers with Cherenkov light detectors of the Yakutsk array: the energy spectrum of cosmic rays

International Nuclear Information System (INIS)

Ivanov, A A; Knurenko, S P; Sleptsov, I Ye

2009-01-01

The energy spectrum of cosmic rays in the range E∼10 15 eV to 6x10 19 eV is studied in this paper using air Cherenkov light detectors of the Yakutsk array. The total flux of photons produced by the relativistic electrons (including positrons as well, hereafter) of extensive air showers in the atmosphere is used as an energy estimator of the primary particle initiating a shower. The resultant differential flux of cosmic rays exhibits, in agreement with previous measurements, a knee and ankle feature at energies of 3x10 15 and ∼10 19 eV, respectively. A comparison of observational data with simulations is made in the knee and ankle regions in order to choose the models of galactic and extragalactic components of cosmic rays that describe well the energy spectrum measured.

Measuring extensive air showers with Cherenkov light detectors of the Yakutsk array: the energy spectrum of cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Ivanov, A A; Knurenko, S P; Sleptsov, I Ye [Shafer Institute for Cosmophysical Research and Aeronomy, Yakutsk 677980 (Russian Federation)], E-mail: ivanov@ikfia.ysn.ru

2009-06-15

The energy spectrum of cosmic rays in the range E{approx}10{sup 15} eV to 6x10{sup 19} eV is studied in this paper using air Cherenkov light detectors of the Yakutsk array. The total flux of photons produced by the relativistic electrons (including positrons as well, hereafter) of extensive air showers in the atmosphere is used as an energy estimator of the primary particle initiating a shower. The resultant differential flux of cosmic rays exhibits, in agreement with previous measurements, a knee and ankle feature at energies of 3x10{sup 15} and {approx}10{sup 19} eV, respectively. A comparison of observational data with simulations is made in the knee and ankle regions in order to choose the models of galactic and extragalactic components of cosmic rays that describe well the energy spectrum measured.

The energy spectrum of cosmic-ray electrons measured with H.E.S.S

International Nuclear Information System (INIS)

Egberts, Kathrin

2009-01-01

The spectrum of cosmic-ray electrons has so far been measured using balloon and satellite-based instruments. At TeV energies, however, the sensitivity of such instruments is very limited due to the low flux of electrons at very high energies and small detection areas of balloon/satellite based experiments. The very large collection area of ground-based imaging atmospheric Cherenkov telescopes gives them a substantial advantage over balloon/ satellite based instruments when detecting very-high-energy electrons (> 300 GeV). By analysing data taken by the High Energy Stereoscopic System (H.E.S.S.), this work extends the known electron spectrum up to 4 TeV - a range that is not accessible to direct measurements. However, in contrast to direct measurements, imaging atmospheric Cherenkov telescopes such as H.E.S.S. detect air showers that cosmic-ray electrons initiate in the atmosphere rather than the primary particle. Thus, the main challenge is to differentiate between air showers initiated by electrons and those initiated by the hadronic background. A new analysis technique was developed that determines the background with the support of the machine-learning algorithm Random Forest. It is shown that this analysis technique can also be applied in other areas such as the analysis of diffuse γ rays from the Galactic plane. (orig.)

The energy spectrum of cosmic-ray electrons measured with H.E.S.S.

Energy Technology Data Exchange (ETDEWEB)

Egberts, Kathrin

2009-03-30

The spectrum of cosmic-ray electrons has so far been measured using balloon and satellite-based instruments. At TeV energies, however, the sensitivity of such instruments is very limited due to the low flux of electrons at very high energies and small detection areas of balloon/satellite based experiments. The very large collection area of ground-based imaging atmospheric Cherenkov telescopes gives them a substantial advantage over balloon/ satellite based instruments when detecting very-high-energy electrons (> 300 GeV). By analysing data taken by the High Energy Stereoscopic System (H.E.S.S.), this work extends the known electron spectrum up to 4 TeV - a range that is not accessible to direct measurements. However, in contrast to direct measurements, imaging atmospheric Cherenkov telescopes such as H.E.S.S. detect air showers that cosmic-ray electrons initiate in the atmosphere rather than the primary particle. Thus, the main challenge is to differentiate between air showers initiated by electrons and those initiated by the hadronic background. A new analysis technique was developed that determines the background with the support of the machine-learning algorithm Random Forest. It is shown that this analysis technique can also be applied in other areas such as the analysis of diffuse {gamma} rays from the Galactic plane. (orig.)

Energy spectrum structure and ''trap'' effects in a three-particle system

International Nuclear Information System (INIS)

Simenog, I.V.; Sitnichenko, A.I.

1982-01-01

Investigation is made of the threshold energy spectrum structure in a system of three spinless particles depending on the form of two-particle interaction. The correlation dependence of the spectrum and low-energy scattering parameters are shown. A new phenomenon of ''traps'' for the spectrum in a three-particle system with interaction involving components of considerably different ranges is established

Energy Efficient Cooperative Spectrum Sensing in Cognitive Radio Networks Using Distributed Dynamic Load Balanced Clustering Scheme

Directory of Open Access Journals (Sweden)

Muthukkumar R.

2017-04-01

Full Text Available Cognitive Radio (CR is a promising and potential technique to enable secondary users (SUs or unlicenced users to exploit the unused spectrum resources effectively possessed by primary users (PUs or licenced users. The proven clustering approach is used to organize nodes in the network into the logical groups to attain energy efficiency, network scalability, and stability for improving the sensing accuracy in CR through cooperative spectrum sensing (CSS. In this paper, a distributed dynamic load balanced clustering (DDLBC algorithm is proposed. In this algorithm, each member in the cluster is to calculate the cooperative gain, residual energy, distance, and sensing cost from the neighboring clusters to perform the optimal decision. Each member in a cluster participates in selecting a cluster head (CH through cooperative gain, and residual energy that minimises network energy consumption and enhances the channel sensing. First, we form the number of clusters using the Markov decision process (MDP model to reduce the energy consumption in a network. In this algorithm, CR users effectively utilize the PUs reporting time slots of unavailability. The simulation results reveal that the clusters convergence, energy efficiency, and accuracy of channel sensing increased considerably by using the proposed algorithm.

Energy Efficient Cooperative Spectrum Sensing in Cognitive Radio Networks Using Distributed Dynamic Load Balanced Clustering Scheme

Directory of Open Access Journals (Sweden)

Muthukkumar R.

2016-07-01

Full Text Available Cognitive Radio (CR is a promising and potential technique to enable secondary users (SUs or unlicenced users to exploit the unused spectrum resources effectively possessed by primary users (PUs or licenced users. The proven clustering approach is used to organize nodes in the network into the logical groups to attain energy efficiency, network scalability, and stability for improving the sensing accuracy in CR through cooperative spectrum sensing (CSS. In this paper, a distributed dynamic load balanced clustering (DDLBC algorithm is proposed. In this algorithm, each member in the cluster is to calculate the cooperative gain, residual energy, distance, and sensing cost from the neighboring clusters to perform the optimal decision. Each member in a cluster participates in selecting a cluster head (CH through cooperative gain, and residual energy that minimises network energy consumption and enhances the channel sensing. First, we form the number of clusters using the Markov decision process (MDP model to reduce the energy consumption in a network. In this algorithm, CR users effectively utilize the PUs reporting time slots of unavailability. The simulation results reveal that the clusters convergence, energy efficiency, and accuracy of channel sensing increased considerably by using the proposed algorithm.

On the Energy Spectrum of Strong Magnetohydrodynamic Turbulence

Directory of Open Access Journals (Sweden)

Jean Carlos Perez

2012-10-01

Full Text Available The energy spectrum of magnetohydrodynamic turbulence attracts interest due to its fundamental importance and its relevance for interpreting astrophysical data. Here we present measurements of the energy spectra from a series of high-resolution direct numerical simulations of magnetohydrodynamics turbulence with a strong guide field and for increasing Reynolds number. The presented simulations, with numerical resolutions up to 2048^{3} mesh points and statistics accumulated over 30 to 150 eddy turnover times, constitute, to the best of our knowledge, the largest statistical sample of steady state magnetohydrodynamics turbulence to date. We study both the balanced case, where the energies associated with Alfvén modes propagating in opposite directions along the guide field, E^{+}(k_{⊥} and E^{-}(k_{⊥}, are equal, and the imbalanced case where the energies are different. In the balanced case, we find that the energy spectrum converges to a power law with exponent -3/2 as the Reynolds number is increased, which is consistent with phenomenological models that include scale-dependent dynamic alignment. For the imbalanced case, with E^{+}>E^{-}, the simulations show that E^{-}∝k_{⊥}^{-3/2} for all Reynolds numbers considered, while E^{+} has a slightly steeper spectrum at small Re. As the Reynolds number increases, E^{+} flattens. Since E^{±} are pinned at the dissipation scale and anchored at the driving scales, we postulate that at sufficiently high Re the spectra will become parallel in the inertial range and scale as E^{+}∝E^{-}∝k_{⊥}^{-3/2}. Questions regarding the universality of the spectrum and the value of the “Kolmogorov constant” are discussed.

Comparative study on γ energy spectrum denoise by fourier and wavelet transforms

International Nuclear Information System (INIS)

Shi Dongsheng; Di Yuming; Zhou Chunlin

2007-01-01

This paper introduces the basic principle of wavelet and Fourier transforms, applies wavelet transform method to denoise γ energy spectrum of 60 Co and compares it with Fourier transform method. The result of simulation with MATLAB software tool showed that as compared with traditional Fourier transform, wavelet transform has comparatively higher accuracy for γ energy spectrum denoising and is more feasible to γ energy spectrum denoising. (authors)

Energy Harvesting-based Spectrum Access with Incremental Cooperation, Relay Selection and Hardware Noises

Directory of Open Access Journals (Sweden)

T. N. Nguyen

2017-04-01

Full Text Available In this paper, we propose an energy harvesting (EH-based spectrum access model in cognitive radio (CR network. In the proposed scheme, one of available secondary transmitters (STs helps a primary transmitter (PT forward primary signals to a primary receiver (PR. Via the cooperation, the selected ST finds opportunities to access licensed bands to transmit secondary signals to its intended secondary receiver (SR. Secondary users are assumed to be mobile, hence, optimization of energy consumption for these users is interested. The EH STs have to harvest energy from the PT's radio-frequency (RF signals to serve the PT-PR communication as well as to transmit their signals. The proposed scheme employs incremental relaying technique in which the PR only requires the assistance from the STs when the transmission between PT and PR is not successful. Moreover, we also investigate impact of hardware impairments on performance of the primary and secondary networks. For performance evaluation, we derive exact and lower-bound expressions of outage probability (OP over Rayleigh fading channel. Monte-Carlo simulations are performed to verify the theoretical results. The results present that the outage performance of both networks can be enhanced by increasing the number of the ST-SR pairs. In addition, it is also shown that fraction of time used for EH, positions of the secondary users and the hardware-impairment level significantly impact on the system performance.

FACT. Energy spectrum of the Crab Nebula

Energy Technology Data Exchange (ETDEWEB)

Temme, Fabian; Einecke, Sabrina; Buss, Jens [TU Dortmund, Experimental Physics 5, Otto-Hahn-Str.4, 44221 Dortmund (Germany); Collaboration: FACT-Collaboration

2016-07-01

The First G-APD Cherenkov Telescope is the first Imaging Air Cherenkov Telescope which uses silicon photon detectors (G-APDs aka SiPM) as photo sensors. With more than four years of operation, FACT proved an application of SiPMs is suitable for the field of ground-based gamma-ray astronomy. Due to the stable flux at TeV energies, the Crab Nebula is handled as a ''standard candle'' in Cherenkov astronomy. The analysis of its energy spectrum and comparison with other experiments, allows to evaluate the performance of FACT. A modern analysis chain, based on data stream handling and multivariate analysis methods was developed in close cooperation with the department of computer science at the TU Dortmund. In this talk, this analysis chain and its application are presented. Further to this, results, including the energy spectrum of the Crab Nebula, measured with FACT, are shown.

Formation of a superhigh energy electron spectrum in the Galaxy

International Nuclear Information System (INIS)

Agaronyan, F.A.; Ambartsumyan, A.S.

1985-01-01

The formation of superhigh energy electron spectrum in the disk of the galaxy and halo is considered. A different behaviour of the electron spectrum within the framework of capture models in disk or halo, in the energy region E> or approximately 10 5 GeV is revealed due to the account of relativistic corrections ir the energy losses of electrons during the inverse Compton scattering. A comparison with the existing experimental data is carried out

Using soft-X-ray energy spectrum to measure electronic temperature Te and primary research with computer data processing

International Nuclear Information System (INIS)

Wang Jingyao; Zhang Guangyang

1993-01-01

The authors reported the application of SCORPIO--2000 Computer detecting system on a nuclear fusion equipment, to measure the energy spectrum of soft X-ray from which the plasma electronic temperature was calculated. The authors processed systematically the data of the energy area of 1-4 Kev soft X-ray. The program edited was mostly made in FORTRAN, but only one SUBSB was made in assembly language. The program worked normally with convincing operation and easy correction of the data. The result obtained from calculation is the same as what was expected and the diagram obtained is the same as the expected one

THE DETECTABILITY OF DARK MATTER ANNIHILATION WITH FERMI USING THE ANISOTROPY ENERGY SPECTRUM OF THE GAMMA-RAY BACKGROUND

International Nuclear Information System (INIS)

Hensley, Brandon S.; Pavlidou, Vasiliki; Siegal-Gaskins, Jennifer M.

2010-01-01

The energy dependence of the anisotropy (the anisotropy energy spectrum) of the large-scale diffuse gamma-ray background can reveal the presence of multiple source populations. Annihilating dark matter in the substructure of the Milky Way halo could give rise to a modulation in the anisotropy energy spectrum of the diffuse gamma-ray emission measured by Fermi, enabling the detection of a dark matter signal. We determine the detectability of a dark-matter-induced modulation for scenarios in which unresolved blazars are the primary contributor to the measured emission above ∼1 GeV and find that in some scenarios pair-annihilation cross sections on the order of the value expected for thermal relic dark matter can produce a detectable feature. We anticipate that the sensitivity of this technique to specific dark matter models could be improved by tailored likelihood analysis methods.

Energy/bandwidth-Saving Cooperative Spectrum Sensing for Two-hopWRAN

Directory of Open Access Journals (Sweden)

Ming-Tuo Zhou

2014-07-01

Full Text Available A two-hop wireless regional area network (WRAN providing monitoring services operating in Television White Space (TVWS, i.e., IEEE P802.22b, may employ a great number of subscriber customer-premises equipments (S-CPEs possibly without mains power supply, leading to requirement of cost-effective and power-saving design. This paper proposes a framework of cooperative spectrum sensing (CSS and an energy/bandwidth saving CSS scheme to P802.22b. In each round of sensing, S-CPEs with SNRs lower than a predefined threshold are excluded from reporting sensing results. Numerical results show that the fused missed-detection probability and false alarmprobability could remainmeeting sensing requirements, and the overall fused error probability changes very little. With 10 S-CPEs, it is possible to save more than 40% of the energy/bandwidth on a Rayleigh channel. The principle proposed can apply to other advanced sensing technologies capable of detecting primary signals with low average SNR.

An Energy-Efficient Spectrum-Aware Reinforcement Learning-Based Clustering Algorithm for Cognitive Radio Sensor Networks.

Science.gov (United States)

Mustapha, Ibrahim; Mohd Ali, Borhanuddin; Rasid, Mohd Fadlee A; Sali, Aduwati; Mohamad, Hafizal

2015-08-13

It is well-known that clustering partitions network into logical groups of nodes in order to achieve energy efficiency and to enhance dynamic channel access in cognitive radio through cooperative sensing. While the topic of energy efficiency has been well investigated in conventional wireless sensor networks, the latter has not been extensively explored. In this paper, we propose a reinforcement learning-based spectrum-aware clustering algorithm that allows a member node to learn the energy and cooperative sensing costs for neighboring clusters to achieve an optimal solution. Each member node selects an optimal cluster that satisfies pairwise constraints, minimizes network energy consumption and enhances channel sensing performance through an exploration technique. We first model the network energy consumption and then determine the optimal number of clusters for the network. The problem of selecting an optimal cluster is formulated as a Markov Decision Process (MDP) in the algorithm and the obtained simulation results show convergence, learning and adaptability of the algorithm to dynamic environment towards achieving an optimal solution. Performance comparisons of our algorithm with the Groupwise Spectrum Aware (GWSA)-based algorithm in terms of Sum of Square Error (SSE), complexity, network energy consumption and probability of detection indicate improved performance from the proposed approach. The results further reveal that an energy savings of 9% and a significant Primary User (PU) detection improvement can be achieved with the proposed approach.

Energy efficient cross layer design for spectrum sharing systems

KAUST Repository

Alabbasi, AbdulRahman; Shihada, Basem

2016-01-01

We propose a cross layer design that optimizes the energy efficiency of spectrum sharing systems. The energy per good bit (EPG) is considered as an energy efficiency metric. We optimize the secondary user's transmission power and media access frame

Adaptive, full-spectrum solar energy system

Science.gov (United States)

Muhs, Jeffrey D.; Earl, Dennis D.

2003-08-05

An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

Spectrum Sensing and Primary User Localization in Cognitive Radio Networks via Sparsity

Directory of Open Access Journals (Sweden)

Lanchao Liu

2016-01-01

Full Text Available The theory of compressive sensing (CS has been employed to detect available spectrum resource in cognitive radio (CR networks recently. Capitalizing on the spectrum resource underutilization and spatial sparsity of primary user (PU locations, CS enables the identification of the unused spectrum bands and PU locations at a low sampling rate. Although CS has been studied in the cooperative spectrum sensing mechanism in which CR nodes work collaboratively to accomplish the spectrum sensing and PU localization task, many important issues remain unsettled. Does the designed compressive spectrum sensing mechanism satisfy the Restricted Isometry Property, which guarantees a successful recovery of the original sparse signal? Can the spectrum sensing results help the localization of PUs? What are the characteristics of localization errors? To answer those questions, we try to justify the applicability of the CS theory to the compressive spectrum sensing framework in this paper, and propose a design of PU localization utilizing the spectrum usage information. The localization error is analyzed by the Cramér-Rao lower bound, which can be exploited to improve the localization performance. Detail analysis and simulations are presented to support the claims and demonstrate the efficacy and efficiency of the proposed mechanism.

Energy detection for spectrum sensing in cognitive radio

CERN Document Server

Atapattu, Saman; Jiang, Hai

2014-01-01

This Springer Brief focuses on the current state-of-the-art research on spectrum sensing by using energy detection, a low-complexity and low-cost technique. It includes a comprehensive summary of recent research, fundamental theories, possible architectures, useful performance measurements of energy detection and applications of energy detection. Concise, practical chapters explore conventional energy detectors, alternative forms of energy detectors, performance measurements, diversity techniques and cooperative networks. The careful analysis enables reader to identify the most efficient techn

Electron energy spectrum and maximum disruption angle under multi-photon beamstrahlung

Energy Technology Data Exchange (ETDEWEB)

Yokoya, Kaoru; Chen, Pisin

1989-03-01

The final electron energy spectrum under multi-photon beamstrahlung process is derived analytically in the classical and the intermediate regimes. The maximum disruption angle from the low energy tail of the spectrum is also estimated. The results are then applied to the TLC and the CLIC parameters. 6 refs., 1 fig., 1 tab.

Secondary access based on sensing and primary ARQ feedback in spectrum sharing systems

KAUST Repository

Hamza, Doha R.

2012-04-01

In the context of primary/secondary spectrum sharing, we propose a randomized secondary access strategy with access probabilities that are a function of both the primary automatic repeat request (ARQ) feedback and the spectrum sensing outcome. The primary terminal operates in a time slotted fashion and is active only when it has a packet to send. The primary receiver can send a positive acknowledgment (ACK) when the received packet is decoded correctly. Lack of ARQ feedback is interpreted as erroneous reception or inactivity. We call this the explicit ACK scheme. The primary receiver may also send a negative acknowledgment (NACK) when the packet is received in error. Lack of ARQ feedback is interpreted as an ACK or no-transmission. This is called the explicit NACK scheme. Under both schemes, when the primary feedback is interpreted as a NACK, the secondary user assumes that there will be retransmission in the next slot and accesses the channel with a certain probability. When the primary feedback is interpreted as an ACK, the secondary user accesses the channel with either one of two probabilities based on the sensing outcome. Under these settings, we find the three optimal access probabilities via maximizing the secondary throughput given a constraint on the primary throughput. We compare the performance of the explicit ACK and explicit NACK schemes and contrast them with schemes based on either sensing or primary ARQ feedback only. © 2012 IEEE.

Understanding the spectrum of domestic energy consumption: Empirical evidence from France

International Nuclear Information System (INIS)

Belaïd, Fateh

2016-01-01

This article focuses on residential energy consumption in France. Using a bottom-up statistical approach, this analysis explores determinants of household energy consumption using data from the most recent National Housing Survey. The primary objective is to tease out the impacts of various factors on the domestic energy consumption spectrum across different population groups. The aim of this approach is to neutralize conventional factors affecting energy consumption (age of house, total area, etc.) to finely analyze the impact of other determinants including those relating to household characteristics and other control variables. First, we define homogeneous consumption groups of households by using multivariate statistical techniques, namely the Multiple Correspondence Analysis and Ascending Hierarchical Classification. Second, we use standard OLS regression to explore the effects of various factors on domestic energy consumption among homogeneous groups of households. This multivariate analysis exercise has led us to identify four main consumption typologies. Results revealed that energy prices were the most important factors determining domestic energy consumption. In addition, this study showed that occupant characteristics significantly affect domestic energy use. Results of this research call for combine all efforts, multiple strategies and smart policies, to incorporate household and consumption behaviors in managing domestic energy consumption. - Highlights: •Survey data of 36,000 occupiers from France is analyzed. •Bottom-up statistical approach is used to analyze domestic energy consumption. •Occupant characteristics significantly affect domestic energy use. •The impact of households attributes varies markedly across consumption groups.

Research on influence of energy spectrum response of ICT detector arrays

International Nuclear Information System (INIS)

Zhou Rifeng; Gao Fuqiang; Zhang Ping

2008-01-01

The energy spectrum response is important characteristic for X-ray ICT detector. But there exist many difficulties to measure these parameters by experiments. The energy spectrum response of CdWO 4 detector was simulated by using the EGSnrc code. Meanwhile the effect of detection efficiency was analyzed by the distribution of accelerator bremsstrahlung spectra and the X-ray spectrum hardening, and some theoretic parameters were offered for the consistent and no-linearity correction of detector arrays. It was applied to ICT image correction, and a satisfying result was obtained. (authors)

Energy and spectrum efficiency in rural areas based on cognitive radio technology

CSIR Research Space (South Africa)

Masonta, MT

2009-09-01

Full Text Available spectrum scarcity in the most energy efficient manner. In this paper, researchers present the proposed work to be carried out as part of a doctoral thesis to address the spectrum scarcity and transmission power in energy constrained rural areas....

The endoscopic spectrum of primary non-Hodgkin's lymphoma of the stomach

NARCIS (Netherlands)

Taal, B. G.; den Hartog Jager, F. C.; Tytgat, G. N.

1987-01-01

Thirty-one consecutive patients with primary non-Hodgkin's lymphoma of the stomach were studied to outline the spectrum of endoscopic abnormalities. The 17 men and 14 women had a median age of 65 years. There were 22 patients in stage I and 9 in stage II. Three endoscopic patterns were recognized:

Nuclear primary energy carriers. Short version

Energy Technology Data Exchange (ETDEWEB)

Jaeck, W

1978-04-01

Basing on our present knowledge the following energy sources for energy supply must be taken into consideration in the long term: regenerative energy sources, fission energy gained by breeder reactors, nuclear fusion. While regenerative energy sources were treated at full length in the study 'Energy Sources for Tomorrow' the present study specifies the other two energy options. The availability and the reliability of nuclear primary energy carrier supply is described in detail and the conversion systems available or still being developed are investigated with regard to their specific consumption of primary energy. Topical questions concerning the proliferation stability of the fuel cycles and techniques are subject to the INFCE program. With reference to the nuclear energy documentation activities of the Federal Government this study is supposed to supply further fundamental material on nuclear primary energy carriers, consumption and readiness for application. Thus it will contribute to the question: 'Is nuclear energy an option which guarantees energy supply in the long term for the Federal Republic of Germany'. (orig.) 891 UA 892 ARA.

Nuclear primary energy carriers. Pt. 1

International Nuclear Information System (INIS)

1978-04-01

Basing on our present knowledge the following energy sources for energy supply must be taken into consideration in the long term: regenerative energy sources, fission energy gained by breeder reactors, nuclear fusion. While regenerative energy sources were treated at full length in the study 'Energy Sources for tomorrow' the present study specifies the other two energy options. The availability and the reliability of nuclear primary energy carrier supply is described in detail and the conversion systems available or still being developed are investigated with regard to their specific consumption of primary energy. Topical questions concerning the proliferation stability of the fuel cycles and techniques are subject to the INFCE programme. With reference to the nuclear energy documentation activities of the Federal Govenment this study is supposed to supply further fundamental material on nuclear primary energy carriers, consumption and readiness for application. Thus it will contribute to the question: 'Is nuclear energy an option which guarantees energy supply in the long term for the Federal Republic of Germany'. (orig.) [de

Energy spectrum of tearing mode turbulence in sheared background field

Science.gov (United States)

Hu, Di; Bhattacharjee, Amitava; Huang, Yi-Min

2018-06-01

The energy spectrum of tearing mode turbulence in a sheared background magnetic field is studied in this work. We consider the scenario where the nonlinear interaction of overlapping large-scale modes excites a broad spectrum of small-scale modes, generating tearing mode turbulence. The spectrum of such turbulence is of interest since it is relevant to the small-scale back-reaction on the large-scale field. The turbulence we discuss here differs from traditional MHD turbulence mainly in two aspects. One is the existence of many linearly stable small-scale modes which cause an effective damping during the energy cascade. The other is the scale-independent anisotropy induced by the large-scale modes tilting the sheared background field, as opposed to the scale-dependent anisotropy frequently encountered in traditional critically balanced turbulence theories. Due to these two differences, the energy spectrum deviates from a simple power law and takes the form of a power law multiplied by an exponential falloff. Numerical simulations are carried out using visco-resistive MHD equations to verify our theoretical predictions, and a reasonable agreement is found between the numerical results and our model.

A method for measuring the energy spectrum of coincidence events in positron emission tomography.

Science.gov (United States)

Goertzen, Andrew L; Stout, David B; Thompson, Christopher J

2010-01-21

Positron emission tomography (PET) system energy response is typically characterized in singles detection mode, yet there are situations in which the energy spectrum of coincidence events might be different than the spectrum measured in singles mode. Examples include imaging with isotopes that emit a prompt gamma in coincidence with a positron emission, imaging with low activity in a LSO/LYSO-based cameras, in which the intrinsic activity is significant, and in high scatter situations where the two 511 keV photons have different scattering probabilities (i.e. off-center line source). The ability to accurately measure the energy spectrum of coincidence events could be used for validating simulation models, optimizing energy discriminator levels and examining scatter models and corrections. For many PET systems operating in coincidence mode, the only method available for estimating the energy spectrum is to step the lower and upper level discriminators (LLD and ULD). Simple measurement techniques such as using a narrow sliding energy window or stepping only the LLD will not yield a spectrum of coincidence events that is accurate for cases where there are different energy components contributing to the spectrum. In this work we propose a new method of measuring the energy spectrum of coincidence events in PET based on a linear combination of two sets of coincident count measurements: one made by stepping the LLD and one made by stepping the ULD. The method was tested using both Monte Carlo simulations of a Siemens microPET R4 camera and measured data acquired on a Siemens Inveon PET camera. The results show that our energy spectrum calculation method accurately measures the coincident energy spectra for cases including the beta/gamma spectrum of the (176)Lu intrinsic activity present in the LSO scintillator crystals, a (68)Ge source and an (124)I source (in which there are prompt gamma-rays emitted together with the positron).

Primary care for adults on the autism spectrum.

Science.gov (United States)

Nicolaidis, Christina; Kripke, Clarissa Calliope; Raymaker, Dora

2014-09-01

Autism spectrum disorder (ASD) is defined by differences in social communication and restricted, repetitive patterns of behavior, interests, or activities. Skills and challenges can change depending on environmental stimuli, supports, and stressors. Quality of life can be improved by the use of accommodations, assistive technologies, therapies to improve adaptive function or communication, caregiver training, acceptance, access, and inclusion. This article focuses on the identification of ASD in adults, referrals for services, the recognition of associated conditions, strategies and accommodations to facilitate effective primary care services, and ethical issues related to caring for autistic adults. Copyright © 2014 Elsevier Inc. All rights reserved.

Determining the primary cosmic ray energy from the total flux of Cherenkov light measured at the Yakutsk EAS array

International Nuclear Information System (INIS)

Ivanov, A. A.; Knurenko, S. P.; Sleptsov, I. E.

2007-01-01

We present a method for determining the energy of the primary particle that generates an extensive air shower (EAS) of comic rays based on measuring the total flux of Cherenkov light from the shower. Applying this method to Cherenkov light measurements at the Yakutsk EAS array has allowed us to construct the cosmic ray energy spectrum in the range 10 15 - 3 x 10 19 eV

An extended formula for the energy spectrum of sputtered atoms from a material irradiated by light ions

International Nuclear Information System (INIS)

Ono, T.; Aoki, Y.; Yamamura, Y.; Kawamura, T.; Kenmotsu, T.

2004-10-01

We extend a formula proposed by Kenmotsu et al. (hereafter Paper I), which fits with the energy spectrum of atoms sputtered from a heavy material hit by low-energy light ions (H + , D + , T + , He + ) by taking into account an inelastic energy loss neglected in Paper I. We assume that primary knock-on atoms produced by ions backscattered at large angles do not lose energy while penetrating the material up to the surface, instead of the energy-loss model used in Paper I. The extended formula is expressed in terms of a normalized energy-distribution function and is compared with the data calculated with the ACAT code for 50 eV, 100 eV and 1 keV D + ions impinging on a Fe target. Our formula fits well with the data in a wide range of incident energy. (author)

Measurement of the ν _{μ } energy spectrum with IceCube-79

Science.gov (United States)

Aartsen, M. G.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Al Samarai, I.; Altmann, D.; Andeen, K.; Anderson, T.; Ansseau, I.; Anton, G.; Archinger, M.; Argüelles, C.; Auffenberg, J.; Axani, S.; Bagherpour, H.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; BenZvi, S.; Berley, D.; Bernardini, E.; Besson, D. Z.; Binder, G.; Bindig, D.; Blaufuss, E.; Blot, S.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Bradascio, F.; Braun, J.; Brayeur, L.; Bretz, H.-P.; Bron, S.; Burgman, A.; Carver, T.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cross, R.; Day, M.; de André, J. P. A. M.; De Clercq, C.; del Pino Rosendo, E.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; di Lorenzo, V.; Dujmovic, H.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Eller, P.; Euler, S.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Fösig, C.-C.; Franckowiak, A.; Friedman, E.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Giang, W.; Gladstone, L.; Glauch, T.; Glüsenkamp, T.; Goldschmidt, A.; Gonzalez, J. G.; Grant, D.; Griffith, Z.; Haack, C.; Hallgren, A.; Halzen, F.; Hansen, E.; Hansmann, T.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Hoshina, K.; Huang, F.; Huber, M.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Kang, W.; Kappes, A.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kheirandish, A.; Kim, J.; Kim, M.; Kintscher, T.; Kiryluk, J.; Kittler, T.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, M.; Krückl, G.; Krüger, C.; Kunnen, J.; Kunwar, S.; Kurahashi, N.; Kuwabara, T.; Kyriacou, A.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lauber, F.; Lennarz, D.; Lesiak-Bzdak, M.; Leuermann, M.; Lu, L.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Mancina, S.; Maruyama, R.; Mase, K.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meier, M.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Micallef, J.; Momenté, G.; Montaruli, T.; Moulai, M.; Nahnhauer, R.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke Pollmann, A.; Olivas, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Peiffer, P.; Penek, Ö.; Pepper, J. A.; Pérez de los Heros, C.; Pieloth, D.; Pinat, E.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relethford, B.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Rysewyk, D.; Sabbatini, L.; Sanchez Herrera, S. E.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Satalecka, K.; Schlunder, P.; Schmidt, T.; Schoenen, S.; Schöneberg, S.; Schumacher, L.; Seckel, D.; Seunarine, S.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stachurska, J.; Stanev, T.; Stasik, A.; Stettner, J.; Steuer, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taavola, H.; Taboada, I.; Tatar, J.; Tenholt, F.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tosi, D.; Tselengidou, M.; Tung, C. F.; Turcati, A.; Unger, E.; Usner, M.; Vandenbroucke, J.; van Eijndhoven, N.; Vanheule, S.; van Rossem, M.; van Santen, J.; Vehring, M.; Voge, M.; Vogel, E.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandkowsky, N.; Waza, A.; Weaver, Ch.; Weiss, M. J.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Wickmann, S.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wolf, M.; Wood, T. R.; Woolsey, E.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zoll, M.

2017-10-01

IceCube is a neutrino observatory deployed in the glacial ice at the geographic South Pole. The ν _μ energy unfolding described in this paper is based on data taken with IceCube in its 79-string configuration. A sample of muon neutrino charged-current interactions with a purity of 99.5% was selected by means of a multivariate classification process based on machine learning. The subsequent unfolding was performed using the software Truee. The resulting spectrum covers an E_ν -range of more than four orders of magnitude from 125 GeV to 3.2 PeV. Compared to the Honda atmospheric neutrino flux model, the energy spectrum shows an excess of more than 1.9 σ in four adjacent bins for neutrino energies E_ν ≥ 177.8 {TeV}. The obtained spectrum is fully compatible with previous measurements of the atmospheric neutrino flux and recent IceCube measurements of a flux of high-energy astrophysical neutrinos.

Measurement of the νμ energy spectrum with IceCube-79

International Nuclear Information System (INIS)

Aartsen, M.G.; Hill, G.C.; Kyriacou, A.; Robertson, S.; Wallace, A.; Whelan, B.J.; Ackermann, M.; Bernardini, E.; Blot, S.; Bradascio, F.; Bretz, H.P.; Franckowiak, A.; Jacobi, E.; Karg, T.; Kintscher, T.; Kunwar, S.; Nahnhauer, R.; Satalecka, K.; Spiering, C.; Stachurska, J.; Stasik, A.; Strotjohann, N.L.; Terliuk, A.; Usner, M.; Santen, J. van; Adams, J.; Bagherpour, H.; Aguilar, J.A.; Ansseau, I.; Heereman, D.; Meagher, K.; Meures, T.; O'Murchadha, A.; Pinat, E.; Raab, C.; Ahlers, M.; Braun, J.; Chirkin, D.; Day, M.; Desiati, P.; Diaz-Velez, J.C.; Fahey, S.; Feintzeig, J.; Ghorbani, K.; Gladstone, L.; Griffith, Z.; Halzen, F.; Hanson, K.; Hoshina, K.; Jero, K.; Karle, A.; Kauer, M.; Kelley, J.L.; Kheirandish, A.; Krueger, C.; Mancina, S.; McNally, F.; Merino, G.; Sabbatini, L.; Tobin, M.N.; Tosi, D.; Vandenbroucke, J.; Van Rossem, M.; Wandkowsky, N.; Wendt, C.; Westerhoff, S.; Wille, L.; Xu, D.L.; Ahrens, M.; Bohm, C.; Dumm, J.P.; Finley, C.; Flis, S.; Hultqvist, K.; Walck, C.; Wolf, M.; Zoll, M.; Al Samarai, I.; Bron, S.; Carver, T.; Christov, A.; Montaruli, T.; Altmann, D.; Anton, G.; Gluesenkamp, T.; Katz, U.; Kittler, T.; Tselengidou, M.; Andeen, K.; Anderson, T.; Dunkman, M.; Eller, P.; Huang, F.; Keivani, A.; Lanfranchi, J.L.; Pankova, D.V.; Quinnan, M.; Tesic, G.; Weiss, M.J.; Archinger, M.; Baum, V.; Boeser, S.; Del Pino Rosendo, E.; Di Lorenzo, V.; Eberhardt, B.; Ehrhardt, T.; Foesig, C.C.; Koepke, L.; Krueckl, G.; Momente, G.; Peiffer, P.; Sandroos, J.; Steuer, A.; Wiebe, K.; Argueelles, C.; Axani, S.; Collin, G.H.; Conrad, J.M.; Jones, B.J.P.; Moulai, M.; Auffenberg, J.; Glauch, T.; Haack, C.; Hansmann, T.; Konietz, R.; Leuermann, M.; Penek, Oe.; Raedel, L.; Reimann, R.; Rongen, M.; Schoenen, S.; Schumacher, L.; Stettner, J.; Vehring, M.; Vogel, E.; Wallraff, M.; Waza, A.; Wickmann, S.; Wiebusch, C.H.; Bai, X.; Barwick, S.W.; Yodh, G.; Bay, R.; Filimonov, K.; Price, P.B.; Woschnagg, K.; Beatty, J.J.; Becker Tjus, J.; Bos, F.; Eichmann, B.; Kroll, M.; Schoeneberg, S.; Tenholt, F.; Becker, K.H.; Bindig, D.; Helbing, K.; Hickford, S.; Hoffmann, R.; Kopper, S.; Lauber, F.; Naumann, U.; Obertacke Pollmann, A.; Soldin, D.; BenZvi, S.; Cross, R.; Berley, D.; Blaufuss, E.; Cheung, E.; Felde, J.; Friedman, E.; Hellauer, R.; Hoffman, K.D.; Maunu, R.; Olivas, A.; Schmidt, T.; Song, M.; Sullivan, G.W.; Besson, D.Z.; Binder, G.; Gerhardt, L.; Klein, S.R.; Miarecki, S.; Palczewski, T.; Tatar, J.; Boerner, M.; Fuchs, T.; Meier, M.; Menne, T.; Pieloth, D.; Rhode, W.; Ruhe, T.; Sandrock, A.; Schlunder, P.

2017-01-01

IceCube is a neutrino observatory deployed in the glacial ice at the geographic South Pole. The ν μ energy unfolding described in this paper is based on data taken with IceCube in its 79-string configuration. A sample of muon neutrino charged-current interactions with a purity of 99.5% was selected by means of a multivariate classification process based on machine learning. The subsequent unfolding was performed using the software Truee. The resulting spectrum covers an E ν -range of more than four orders of magnitude from 125 GeV to 3.2 PeV. Compared to the Honda atmospheric neutrino flux model, the energy spectrum shows an excess of more than 1.9σ in four adjacent bins for neutrino energies E ν ≥ 177.8 TeV. The obtained spectrum is fully compatible with previous measurements of the atmospheric neutrino flux and recent IceCube measurements of a flux of high-energy astrophysical neutrinos. (orig.)

Measurements of the energy spectrum of backscattered fast neutrons

International Nuclear Information System (INIS)

Segal, Y.

1976-03-01

Experimental measurements have been made of the energy spectra of neutrons transmitted through slabs of iron, lead and perspex for incident neutron energies of 0.5, 1.0, 1.5 and 1.8 MeV. The neutron energy measurements were made using a He-3 spectrometer. The dependence of the neutrons energy spectrum as a function of scattering thickness was determined. The neutrons source used was a 3MeV Van de Graaff accelerator with a tritium target using the H 3 (p,n) He 3 reaction. The results obtained by the investigator on energy dependence of transmitted neutrons as a function of thickness of scattering material were compared, where possible, with the results obtained by other workers. The comparisons indicated good agreement. The experiment's results are compared with MORSE Monte Carlo calculated values. It is worthwhile to note that direct comparison between measured cross section values and the recommended ones are very far from satisfactory. In almost all cases the calculated spectrum is harder than the experimental one, a situation common to the penetrating and the back-scattered flux

Life cycle primary energy analysis of residential buildings

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, Leif; Joelsson, Anna [Ecotechnology, Department of Engineering and Sustainable Development, Mid Sweden University, SE-831 25 Oestersund (Sweden)

2010-02-15

The space heating demand of residential buildings can be decreased by improved insulation, reduced air leakage and by heat recovery from ventilation air. However, these measures result in an increased use of materials. As the energy for building operation decreases, the relative importance of the energy used in the production phase increases and influences optimization aimed at minimizing the life cycle energy use. The life cycle primary energy use of buildings also depends on the energy supply systems. In this work we analyse primary energy use and CO{sub 2} emission for the production and operation of conventional and low-energy residential buildings. Different types of energy supply systems are included in the analysis. We show that for a conventional and a low-energy building the primary energy use for production can be up to 45% and 60%, respectively, of the total, depending on the energy supply system, and with larger variations for conventional buildings. The primary energy used and the CO{sub 2} emission resulting from production are lower for wood-framed constructions than for concrete-framed constructions. The primary energy use and the CO{sub 2} emission depend strongly on the energy supply, for both conventional and low-energy buildings. For example, a single-family house from the 1970s heated with biomass-based district heating with cogeneration has 70% lower operational primary energy use than if heated with fuel-based electricity. The specific primary energy use with district heating was 40% lower than that of an electrically heated passive row house. (author)

2005 primary energy consumption in Germany

International Nuclear Information System (INIS)

Anon.

2006-01-01

According to preliminar calculations by the Arbeitsgemeinschaft Energiebilanzen (Working Party on Energy Balances, AGEB), the consumption of an aggregate 486 million TCE of primary energy resources in Germany last year was 1.3% below the level of the year before. Energy consumption was influenced by both the high level of prices and the development of the economy. Hardly any influence was attributable to the level of temperatures, which was largely unchanged compared to the figure of the year before. Oil consumption in 2005 in Germany dropped by nearly 2% to 174.8 million TCE. On the whole, oil with its 36% share in the energy balance remained by far the most important energy resource in Germany. Natural gas consumption of 110.4 million TCE was at the level of the year before. Its share in the primary energy balance rose slightly to 22.7%. Hard coal, because of lower use in power plants and the decline in iron making, showed a 4.6% drop in consumption to 62.8 million TCE. In this way, hard coal contributed 13% to total energy consumption. Lignite consumption dropped by 3.2% to 54.4 million TCE as a result of lower deliveries to power plants. Its 11.2% share in the total consumption of primary energy continued to make lignite the most important domestic energy resource. More than 90% of the lignite produced is used for electricity generation. The contribution to primary energy consumption of nuclear power dropped by more than 2% to 60.7 million TCE. Hydroelectric plants and wind power plants increased their contribution by 3.6%. The contribution to primary energy consumption made by all renewable energy resources rose to 4.6%. AGEB evaluates statistics of all areas of the power economy on the basis of standard criteria in order to combine these data in a comprehensive picture. Since 1994, the energy balances for Germany have been compiled by DIW on behalf of AGEB. (orig.)

Performance analysis of spectrum sensing with multiple status changes in primary user traffic

KAUST Repository

Tang, Liang; Chen, Yunfei; Hines, Evor L.; Alouini, Mohamed-Slim

2012-01-01

In this letter, the impact of primary user traffic with multiple status changes on the spectrum sensing performance is analyzed. Closed-form expressions for the probabilities of false alarm and detection are derived. Numerical results show

ADAPTIVE FULL-SPECTRUM SOLOR ENERGY SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Byard D. Wood

2004-04-01

This RD&D project is a three year team effort to develop a hybrid solar lighting (HSL) system that transports solar light from a paraboloidal dish concentrator to a luminaire via a large core polymer fiber optic. The luminaire can be a device to distribute sunlight into a space for the production of algae or it can be a device that is a combination of solar lighting and electric lighting. A benchmark prototype system has been developed to evaluate the HSL system. Sunlight is collected using a one-meter paraboloidal concentrator dish with two-axis tracking. A secondary mirror consisting of eight planar-segmented mirrors directs the visible part of the spectrum to eight fibers (receiver) and subsequently to eight luminaires. This results in about 8,200 lumens incident at each fiber tip. Each fiber can illuminate about 16.7 m{sup 2} (180 ft{sup 2}) of office space. The IR spectrum is directed to a thermophotovoltaic (TPV) array to produce electricity. During this reporting period, the project team made advancements in the design of the second generation (Alpha) system. For the Alpha system, the eight individual 12 mm fibers have been replaced with a centralized bundle of 3 mm fibers. The TRNSYS Full-Spectrum Solar Energy System model has been updated and new components have been added. The TPV array and nonimaging device have been tested and progress has been made in the fiber transmission models. A test plan was developed for both the high-lumen tests and the study to determine the non-energy benefits of daylighting. The photobioreactor team also made major advancements in the testing of model scale and bench top lab-scale systems.

Empirical and dynamic primary energy factors

International Nuclear Information System (INIS)

Wilby, Mark Richard; Rodríguez González, Ana Belén; Vinagre Díaz, Juan José

2014-01-01

Current legislation, standards, and scientific research in the field of energy efficiency often make use of PEFs (primary energy factors). The measures employed are usually fixed and based on theoretical calculations. However given the intrinsically variable nature of energy systems, these PEFs should rely on empirical data and evolve in time. Otherwise the obtained efficiencies may not be representative of the actual energy system. In addition, incorrect PEFs may cause a negative effect on the energy efficiency measures. For instance, imposing a high value on the PEF of electricity may discourage the use of renewable energy sources, which have an actual value close to 1. In order to provide a solution to this issue, we propose an application of the Energy Networks (ENs), described in a previous work, to calculate dynamic PEFs based on empirical data. An EN represents an entire energy system both numerically and graphically, from its primary energy sources to their final energy forms, and consuming sectors. Using ENs we can calculate the PEF of any energy form and depict it in a simple and meaningful graph that shows the details of the contribution of each primary energy and the efficiency of the associated process. The analysis of these PEFs leads to significant conclusions regarding the energy models adopted among countries, their evolution in time, the selection of viable ways to improve efficiency, and the detection of best practices that could contribute to the overall energy efficiency targets. - Highlights: • Primary Energy Factors (PEFs) are foundation of much energy legislation and research. • Traditionally, they have been treated as geotemporally invariant. • This work provides a systematic and transparent methodology for adding variability. • It also shows the variability between regions due to market, policy, and technology. • Finally it demonstrates the utility of extended PEFs as a tool in their own right

On the coexistence of primary and secondary users in spectrum-sharing broadcast channels

KAUST Repository

Yang, Yuli

2013-06-01

In this paper, we consider a broadcast channel in spectrum-sharing networks, where the base station schedules licensed primary users (PUs) and cognitive secondary users (SUs) simultaneously. Based on such a framework, we present a transmission strategy in the light of dirty paper coding. In order to promise the PUs\\' quality of service (QoS) in the broadcasting, the base station chooses codewords for the users by taking into account that the codewords pertaining to SUs can be pre-subtracted from those pertaining to PUs as if there were no interference from the secondary\\'s data to the primary\\'s data. For the purpose of performance evaluation, by taking capacity behavior and bit error rate (BER) as metrics, we study the achievable data rate regions for both types of users with the introduced design, and analyze the BER performance in corresponding systems implemented with hierarchical modulation. Numerical results substantiate that with flexible management of the spectrum resources, our proposed scheme provides more communication opportunities for SUs while maintaining PUs\\' QoS at an acceptable level. © 2013 IEEE.

Learning Frameworks for Cooperative Spectrum Sensing and Energy-Efficient Data Protection in Cognitive Radio Networks

Directory of Open Access Journals (Sweden)

Vinh Quang Do

2018-05-01

Full Text Available This paper studies learning frameworks for energy-efficient data communications in an energy-harvesting cognitive radio network in which secondary users (SUs harvest energy from solar power while opportunistically accessing a licensed channel for data transmission. The SUs perform spectrum sensing individually, and send local decisions about the presence of the primary user (PU on the channel to a fusion center (FC. We first design a new cooperative spectrum-sensing technique based on a convolutional neural network in which the FC uses historical sensing data to train the network for classification problem. The system is assumed to operate in a time-slotted manner. At the beginning of each time slot, the FC uses the current local decisions as input for the trained network to decide whether the PU is active or not in that time slot. In addition, legitimate transmissions can be vulnerable to a hidden eavesdropper, which always passively listens to the communication. Therefore, we further propose a transfer learning actor–critic algorithm for an SU to decide its operation mode to increase the security level under the constraint of limited energy. In this approach, the SU directly interacts with the environment to learn its dynamics (i.e., an arrival of harvested energy; then, the SU can either stay idle to save energy or transmit to the FC secured data that are encrypted using a suitable private-key encryption method to maximize the long-term effective security level of the network. We finally present numerical simulation results under various configurations to evaluate our proposed schemes.

Performance analysis of spectrum sensing with multiple status changes in primary user traffic

KAUST Repository

Tang, Liang

2012-06-01

In this letter, the impact of primary user traffic with multiple status changes on the spectrum sensing performance is analyzed. Closed-form expressions for the probabilities of false alarm and detection are derived. Numerical results show that the multiple status changes of the primary user cause considerable degradation in the sensing performance. This degradation depends on the number of changes, the primary user traffic model, the primary user traffic intensity and the signal-to-noise ratio of the received signal. Numerical results also show that the amount of degradation decreases when the number of changes increases, and converges to a minimum sensing performance due to the limited sensing period and primary holding time. © 2012 IEEE.

Research on multi-spectrum detector in high-energy dual-energy X-ray imaging system

International Nuclear Information System (INIS)

Li Qinghua; Wang Xuewu; Li Jianmin; Kang Kejun; Li Yuanjing; Zhong Huaqiang

2008-01-01

The high-energy dual-energy X-ray imaging system can discriminate the material of the objects inspected, but when the objects are too thin, the discrimination becomes very difficult. This paper proposes the use of multi-spectrum detector to improve the ability to discriminate thin material, and a series of simulation were done with the Monte Carlo method. Firstly the X-ray depositions in the detectors with different thickness were calculated, and then the discrimination effects with different detector structure and parameters were calculated. The simulation results validated that using appropriate multi-spectrum detector can improve the discrimination accuracy of thin material, particularly thin high-Z material. (authors)

Partial decay energy of 51Cr from inner bremsstrahlung spectrum

International Nuclear Information System (INIS)

Sanjeeviah, H.; Sanjeevaiah, B.

1980-01-01

The inner bremsstrahlung spectrum accompanying orbital electron capture decay of 51 Cr to the first excited state in 51 V was measured in coincidence with 320 keV gamma rays. From the Jauch plot of the spectrum the partial decay energy was deduced to be 433 +- 18 keV in good agreement with the previously measured value and the accepted mass difference. The overall shape factor of the inner bremsstrahlung spectrum was found to be a constant X(1.1 +- 0.1). (author)

Systematic Studies of Cosmic-Ray Anisotropy and Energy Spectrum with IceCube and IceTop

Science.gov (United States)

McNally, Frank

Anisotropy in the cosmic-ray arrival direction distribution has been well documented over a large energy range, but its origin remains largely a mystery. In the TeV to PeV energy range, the galactic magnetic field thoroughly scatters cosmic rays, but anisotropy at the part-per-mille level and smaller persists, potentially carrying information about nearby cosmic-ray accelerators and the galactic magnetic field. The IceCube Neutrino Observatory was the first detector to observe anisotropy at these energies in the Southern sky. This work uses 318 billion cosmic-ray induced muon events, collected between May 2009 and May 2015 from both the in-ice component of IceCube as well as the surface component, IceTop. The observed global anisotropy features large regions of relative excess and deficit, with amplitudes on the order of 10-3. While a decomposition of the arrival direction distribution into spherical harmonics shows that most of the power is contained in the low-multipole (ℓ ≤ 4) moments, higher-multipole components are found to be statistically significant down to an angular scale of less than 10°, approaching the angular resolution of the detector. Above 100TeV, a change in the topology of the arrival direction distribution is observed, and the anisotropy is characterized by a wide relative deficit whose amplitude increases with primary energy up to at least 5PeV, the highest energies currently accessible to IceCube with sufficient event statistics. No time dependence of the large- and small-scale structures is observed in the six-year period covered by this analysis within statistical and systematic uncertainties. Analysis of the energy spectrum and composition in the PeV energy range as a function of sky position is performed with IceTop data over a five-year period using a likelihood-based reconstruction. Both the energy spectrum and the composition distribution are found to be consistent with a single source population over declination bands. This work

Energy spectrum inverse problem of q -deformed harmonic oscillator and WBK approximation

International Nuclear Information System (INIS)

Sang, Nguyen Anh; Thuy, Do Thi Thu; Loan, Nguyen Thi Ha; Lan, Nguyen Tri; Viet, Nguyen Ai

2016-01-01

Using the connection between q-deformed harmonic oscillator and Morse-like anharmonic potential we investigate the energy spectrum inverse problem. Consider some energy levels of energy spectrum of q -deformed harmonic oscillator are known, we construct the corresponding Morse-like potential then find out the deform parameter q . The application possibility of using the WKB approximation in the energy spectrum inverse problem was discussed for the cases of parabolic potential (harmonic oscillator), Morse-like potential ( q -deformed harmonic oscillator). so we consider our deformed-three-levels simple model, where the set-parameters of Morse potential and the corresponding set-parameters of level deformations are easily and explicitly defined. For practical problems, we propose the deformed- three-levels simple model, where the set-parameters of Morse potential and the corresponding set-parameters of level deformations are easily and explicitly defined. (paper)

Access to primary energy sources - the basis of national energy security

Science.gov (United States)

Szlązak, Jan; Szlązak, Rafał A.

2017-11-01

National energy security is of fundamental importance for economic development of a country. To ensure such safety energy raw material, also called primary energy sources, are necessary. Currently in Poland primary energy sources include mainly fossil fuels, such as hard coal, brown coal, natural gas and crude oil. Other sources, e.g. renewable energy sources account for c. 15% in the energy mix. Primary energy sources are used to produce mainly electricity, which is considered as the cleanest form of energy. Poland does not have, unfortunately, sufficient energy sources and is forced to import some of them, mainly natural gas and crude oil. The article presents an insightful analysis of energy raw material reserves possessed by Poland and their structure taking account of the requirements applicable in the European Union, in particular, those related to environmental protection. The article also describes demand for electricity now and in the perspective of 2030. Primary energy sources necessary for its production have also been given. The article also includes the possibilities for the use of renewable energy sources in Poland, however, climatic conditions there are not are not particularly favourable to it. All the issues addressed in the article are summed up and ended with conclusions.

Spectrum sensing algorithm based on autocorrelation energy in cognitive radio networks

Science.gov (United States)

Ren, Shengwei; Zhang, Li; Zhang, Shibing

2016-10-01

Cognitive radio networks have wide applications in the smart home, personal communications and other wireless communication. Spectrum sensing is the main challenge in cognitive radios. This paper proposes a new spectrum sensing algorithm which is based on the autocorrelation energy of signal received. By taking the autocorrelation energy of the received signal as the statistics of spectrum sensing, the effect of the channel noise on the detection performance is reduced. Simulation results show that the algorithm is effective and performs well in low signal-to-noise ratio. Compared with the maximum generalized eigenvalue detection (MGED) algorithm, function of covariance matrix based detection (FMD) algorithm and autocorrelation-based detection (AD) algorithm, the proposed algorithm has 2 11 dB advantage.

Energy spectrum of Compton scattering of laser photons on relativistic electrons

International Nuclear Information System (INIS)

Ando, Hiroaki; Yoneda, Yasuharu

1976-01-01

The high energy photons in gamma-ray region are obtainable by the Compton scattering of laser photons on relativistic electrons. But the motion of the electrons in the storage ring is not necessarily uniform. In the study of the uneven effect, the energy distribution of scattered photons is derived from the assumed momentum distribution of incident electrons. It is generally impossible to derive the momentum distribution of incident electrons from the energy spectrum of scattered photons. The additional conditions which make this possible in a special case are considered. A calculational method is examined for deriving the energy spectrum of scattered photons from the assumed momentum distribution of incident electrons. (Mori, K.)

Energy spectrum of argon ions emitted from Filippov type Sahand plasma focus

International Nuclear Information System (INIS)

Mohammadnejad, M.; Pestehe, S. J.; Mohammadi, M. A.

2013-01-01

The energy and flux of the argon ions produced in Sahand plasma focus have been measured by employing a well-designed Faraday cup. The secondary electron emission effects on the ion signals are simulated and the dimensions of Faraday cup are optimized to minimize these effects. The measured ion energy spectrum is corrected for the ion energy loss and charge exchange in the background gas. The effects of the capacitor bank voltage and working gas pressure on the ion energy spectrum are also investigated. It has been shown that the emitted ion number per energy increases as the capacitor bank voltage increases. Decreasing the working gas pressure leads to the increase in the number of emitted ion per energy

The Cosmic Ray spectrum in the energy region between 1012 and 1016 eV measured by ARGO–YBJ

Directory of Open Access Journals (Sweden)

Montini Paolo

2017-01-01

Full Text Available The ARGO-YBJ experiment has been in full and stable data taking at the Yangbajing cosmic ray observatory (Tibet, P.R. China, 4300 m a.s.l. for more than five years. The detector has been designed in order to explore the Cosmic Ray (CR spectrum in an energy range from few TeV up to several PeV. The high segmentation of the detector allows a detailed measurement of the lateral particle distribution which can be exploited on order to identify showers produced by primaries of different mass. The results of the measurement of the all-particle and proton plus helium energy spectra in the energy region between 1012 and 1016 eV are discussed.

Energy-efficient routing, modulation and spectrum allocation in elastic optical networks

Science.gov (United States)

Tan, Yanxia; Gu, Rentao; Ji, Yuefeng

2017-07-01

With tremendous growth in bandwidth demand, energy consumption problem in elastic optical networks (EONs) becomes a hot topic with wide concern. The sliceable bandwidth-variable transponder in EON, which can transmit/receive multiple optical flows, was recently proposed to improve a transponder's flexibility and save energy. In this paper, energy-efficient routing, modulation and spectrum allocation (EE-RMSA) in EONs with sliceable bandwidth-variable transponder is studied. To decrease the energy consumption, we develop a Mixed Integer Linear Programming (MILP) model with corresponding EE-RMSA algorithm for EONs. The MILP model jointly considers the modulation format and optical grooming in the process of routing and spectrum allocation with the objective of minimizing the energy consumption. With the help of genetic operators, the EE-RMSA algorithm iteratively optimizes the feasible routing path, modulation format and spectrum resources solutions by explore the whole search space. In order to save energy, the optical-layer grooming strategy is designed to transmit the lightpath requests. Finally, simulation results verify that the proposed scheme is able to reduce the energy consumption of the network while maintaining the blocking probability (BP) performance compare with the existing First-Fit-KSP algorithm, Iterative Flipping algorithm and EAMGSP algorithm especially in large network topology. Our results also demonstrate that the proposed EE-RMSA algorithm achieves almost the same performance as MILP on an 8-node network.

Hard x-ray to low energy gamma ray spectrum of the Crab Nebula

International Nuclear Information System (INIS)

Jung, G.V.

1986-01-01

The spectrum of the Crab Nebula has been determined in the energy range 10 keV to 5 MeV from the data of the UCSD/MIT Hard-X-ray and Low Energy Gamma Ray Experiment on the first High Energy Astronomy Observatory, HEAO-1. The x-ray to γ-ray portion of the continuous emission from the Crab is indicative of the electron spectrum, its transport through the nebula, and the physical conditions near the shocked interface between the nebular region and the wind which is the physical link between the nebula and the pulsar, NP0532. The power-law dependence of the spectrum found in the lower-energy decade of this observation (10 to 100 keV) is not continued without modification to higher energies. Evidence for this has been accumulating from previous observations in the γ-ray ranges of 1-10 MeV and above 35 MeV. The observations on which this dissertation is based further characterize the spectral change in the 100 keV to 1 MeV region. These observations provide a crucial connection between the x-ray and γ-ray spectrum of the non-pulsed emission of the Crab Nebula. The continuity of this spectrum suggests that the emission mechanism responsible for the non-pulsed γ-rays observed above 35 MeV is of the same origin as the emission at lower energies, i.e. that of synchrotron radiation in the magnetic field of the nebula

Hofstadter's butterfly energy spectrum of ultracold fermions on the two-dimensional triangular optical lattice

International Nuclear Information System (INIS)

Hou Jingmin; Lu Qingqing

2009-01-01

We study the energy spectrum of ultracold fermionic atoms on the two-dimensional triangular optical lattice subjected to a perpendicular effective magnetic field, which can be realized with laser beams. We derive the generalized Harper's equations and numerically solve them, then we obtain the Hofstadter's butterfly-like energy spectrum, which has a novel fractal structure. The observability of the Hofstadter's butterfly spectrum is also discussed

Characterization of the Photon Energy Spectrum of a 6 MV Linac

International Nuclear Information System (INIS)

Hernandez Bojorquez, M.; Larraga, J. M.; Garcia, A.; Celis, M. A.; Martinez-Davalos, A.; Rodriguez-Villafuerte, M.

2006-01-01

In this work we study the influence of the purity of the materials used in experimental transmission measurements to obtain data to reconstruct the photon energy spectrum of a 6 MV Linac. We also evaluate the contribution to PDDs due to electron contamination in the reconstructed spectrum

Wavelet Spatial Energy Spectrums Studies on Drag Reduction by Micro-bubble Injection

International Nuclear Information System (INIS)

Ling Zhen; Yassin Hassan

2006-01-01

In this study, continuous wavelet transforms and spatial correlation techniques are employed to determine the space-localized wavenumber energy spectrum of the velocity signals in turbulent channel flow. The flow conditions correspond to single phase flow and micro-bubbles injected two phase flow. The wavelet energy spectrums demonstrate that the wavenumber (eddy size) content of the velocity signals is not only space-dependent but also micro-bubbles can impact the eddy size content. Visual observations of the wavelet energy spectrum spatial distribution was realized by using Particle Image Velocimetry (PIV) measurement technique. The two phase flow condition corresponds to a drag reduction of 38.4% with void fraction of 4.9%. The present results provide evidence that micro-bubbles in the boundary layer of a turbulent channel flow can help adjust the eddy size distributions near the wall. This can assist in explaining that micro-bubbles are performing as buffers to keep the energy of fluid particles going in stream-wise direction and reducing the energy of fluid particles going in normal direction. (authors)

Spectrum and energy levels of four-times-ionized niobium

International Nuclear Information System (INIS)

Kagan, D.T.; Conway, J.G.; Meinders, E.

1981-01-01

The 4p 6 nl spectrum of Nb 4+ was measured and analyzed. The spectrum was excited in a vacuum sliding spark source with a peak current of 800 A and a pulse width of 70 μsec. The analysis of the spectrum has extended the 12 known lines to 84 and the 10 known levels to 30. The ionization energy was calculated to be 407897 +- 40 cm -1 . There is strong evidence that the 4p 5 4d 2 configurations interacts strongly with the 4p 6 nf configuration. In addition, the hyperfine splitting of the 4p 6 6s level has been observed and measured to be 1.1 cm -1

Measurement of the ν{sub μ} energy spectrum with IceCube-79

Energy Technology Data Exchange (ETDEWEB)

Aartsen, M.G.; Hill, G.C.; Kyriacou, A.; Robertson, S.; Wallace, A.; Whelan, B.J. [University of Adelaide, Department of Physics, Adelaide (Australia); Ackermann, M.; Bernardini, E.; Blot, S.; Bradascio, F.; Bretz, H.P.; Franckowiak, A.; Jacobi, E.; Karg, T.; Kintscher, T.; Kunwar, S.; Nahnhauer, R.; Satalecka, K.; Spiering, C.; Stachurska, J.; Stasik, A.; Strotjohann, N.L.; Terliuk, A.; Usner, M.; Santen, J. van [DESY, Zeuthen (Germany); Adams, J.; Bagherpour, H. [University of Canterbury, Department of Physics and Astronomy, Christchurch (New Zealand); Aguilar, J.A.; Ansseau, I.; Heereman, D.; Meagher, K.; Meures, T.; O' Murchadha, A.; Pinat, E.; Raab, C. [Universite Libre de Bruxelles, Science Faculty CP230, Brussels (Belgium); Ahlers, M.; Braun, J.; Chirkin, D.; Day, M.; Desiati, P.; Diaz-Velez, J.C.; Fahey, S.; Feintzeig, J.; Ghorbani, K.; Gladstone, L.; Griffith, Z.; Halzen, F.; Hanson, K.; Hoshina, K.; Jero, K.; Karle, A.; Kauer, M.; Kelley, J.L.; Kheirandish, A.; Krueger, C.; Mancina, S.; McNally, F.; Merino, G.; Sabbatini, L.; Tobin, M.N.; Tosi, D.; Vandenbroucke, J.; Van Rossem, M.; Wandkowsky, N.; Wendt, C.; Westerhoff, S.; Wille, L.; Xu, D.L. [University of Wisconsin, Department of Physics and Wisconsin IceCube Particle Astrophysics Center, Madison, WI (United States); Ahrens, M.; Bohm, C.; Dumm, J.P.; Finley, C.; Flis, S.; Hultqvist, K.; Walck, C.; Wolf, M.; Zoll, M. [Stockholm University, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Al Samarai, I.; Bron, S.; Carver, T.; Christov, A.; Montaruli, T. [Universite de Geneve, Departement de physique nucleaire et corpusculaire, Geneva (Switzerland); Altmann, D.; Anton, G.; Gluesenkamp, T.; Katz, U.; Kittler, T.; Tselengidou, M. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen (Germany); Andeen, K. [Marquette University, Department of Physics, Milwaukee, WI (United States); Anderson, T.; Dunkman, M.; Eller, P.; Huang, F.; Keivani, A.; Lanfranchi, J.L.; Pankova, D.V.; Quinnan, M.; Tesic, G.; Weiss, M.J. [Pennsylvania State University, Department of Physics, University Park, PA (United States); Archinger, M.; Baum, V.; Boeser, S.; Del Pino Rosendo, E.; Di Lorenzo, V.; Eberhardt, B.; Ehrhardt, T.; Foesig, C.C.; Koepke, L.; Krueckl, G.; Momente, G.; Peiffer, P.; Sandroos, J.; Steuer, A.; Wiebe, K. [University of Mainz, Institute of Physics, Mainz (Germany); Argueelles, C.; Axani, S.; Collin, G.H.; Conrad, J.M.; Jones, B.J.P.; Moulai, M. [Massachusetts Institute of Technology, Department of Physics, Cambridge, MA (United States); Auffenberg, J.; Glauch, T.; Haack, C.; Hansmann, T.; Konietz, R.; Leuermann, M.; Penek, Oe.; Raedel, L.; Reimann, R.; Rongen, M.; Schoenen, S.; Schumacher, L.; Stettner, J.; Vehring, M.; Vogel, E.; Wallraff, M.; Waza, A.; Wickmann, S.; Wiebusch, C.H. [RWTH Aachen University, III. Physikalisches Institut, Aachen (Germany); Bai, X. [South Dakota School of Mines and Technology, Physics Department, Rapid City, SD (United States); Barwick, S.W.; Yodh, G. [University of California, Department of Physics and Astronomy, Irvine, CA (United States); Bay, R.; Filimonov, K.; Price, P.B.; Woschnagg, K. [University of California, Department of Physics, Berkeley, CA (United States); Beatty, J.J. [Ohio State University, Department of Physics and Center for Cosmology and Astro-Particle Physics, Columbus, OH (United States); Ohio State University, Department of Astronomy, Columbus, OH (United States); Becker Tjus, J.; Bos, F.; Eichmann, B.; Kroll, M.; Schoeneberg, S.; Tenholt, F. [Ruhr-Universitaet Bochum, Fakultaet fuer Physik and Astronomie, Bochum (Germany); Becker, K.H.; Bindig, D.; Helbing, K.; Hickford, S.; Hoffmann, R.; Kopper, S.; Lauber, F.; Naumann, U.; Obertacke Pollmann, A.; Soldin, D. [University of Wuppertal, Department of Physics, Wuppertal (Germany); BenZvi, S.; Cross, R. [University of Rochester, Department of Physics and Astronomy, Rochester, NY (United States); Berley, D.; Blaufuss, E.; Cheung, E.; Felde, J.; Friedman, E.; Hellauer, R.; Hoffman, K.D.; Maunu, R.; Olivas, A.; Schmidt, T.; Song, M.; Sullivan, G.W. [University of Maryland, Department of Physics, College Park, MD (United States); Besson, D.Z. [University of Kansas, Department of Physics and Astronomy, Lawrence, KS (United States); Binder, G.; Gerhardt, L.; Klein, S.R.; Miarecki, S.; Palczewski, T.; Tatar, J. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Boerner, M.; Fuchs, T.; Meier, M.; Menne, T.; Pieloth, D.; Rhode, W.; Ruhe, T.; Sandrock, A.; Schlunder, P. [TU Dortmund University, Department of Physics, Dortmund (Germany); Collaboration: IceCube Collaboration; and others

2017-10-15

IceCube is a neutrino observatory deployed in the glacial ice at the geographic South Pole. The ν{sub μ} energy unfolding described in this paper is based on data taken with IceCube in its 79-string configuration. A sample of muon neutrino charged-current interactions with a purity of 99.5% was selected by means of a multivariate classification process based on machine learning. The subsequent unfolding was performed using the software Truee. The resulting spectrum covers an E{sub ν}-range of more than four orders of magnitude from 125 GeV to 3.2 PeV. Compared to the Honda atmospheric neutrino flux model, the energy spectrum shows an excess of more than 1.9σ in four adjacent bins for neutrino energies E{sub ν} ≥ 177.8 TeV. The obtained spectrum is fully compatible with previous measurements of the atmospheric neutrino flux and recent IceCube measurements of a flux of high-energy astrophysical neutrinos. (orig.)

Decay energy of 55Fe from its inner Bremsstrahlung spectrum

Science.gov (United States)

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.

Decay energy of 55Fe from its inner Bremsstrahlung spectrum

International Nuclear Information System (INIS)

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)

D{sup -} energy spectrum in toroidal quantum ring

Energy Technology Data Exchange (ETDEWEB)

Gomez, C A; Gutierrez, W; Garcia, L F [Universidad Industrial de Santander, Bucaramanga (Colombia); Marin, J H, E-mail: jhmarin@unal.edu.c [Universidad Nacional-Colombia, Medellin-Colombia, AA3840 (Colombia)

2009-05-01

The structure of energy spectrum of the negative donor centre in a toroidal-shaped quantum ring with two different morphologies of the cross-section is analyzed. By using the adiabatic procedure we have deduced a one-dimensional wave equation with periodic conditions which describes the low-lying energy levels related to the electrons rotation around the symmetry axis. Our results are in good agreement with those previously obtained as the size of the ring cross-section tends to zero.

Study of the secondary electron energy spectrum of clean aluminium modification during oxygen adsorption, hydrogen adsorption or carbon segregation

International Nuclear Information System (INIS)

Pellerin, Francois

1981-01-01

The first part of this work is a review of both theoretical and experimental aspects of the fine structure appearing in the Secondary Electron Spectrum (SES) and in the electron energy loss spectrum. In the second part, we report the results of a study of the SES and ELS spectra of clean and gas covered aluminium. The use of very low primary electron energies (E p ≤ 30 eV) enables the detection of previously unobserved peaks in the ELS spectra of clean and oxygen covered aluminium. They are attributed to single electron excitations. Furthermore, a very large peak appears in the SES spectrum during oxygen or carbon adsorption on aluminium. It is interpreted in terms of interaction of the background electrons with the valence electrons of the surface. Molecular hydrogen adsorption is observed on Ta, Pt, Al 2 O 3 , Si. It is responsible for an ELS peak located 13 eV below the elastic peak. Furthermore, on silicon, the chemisorbed hydrogen form can be distinguished from the molecular form with the help of ELS. Finally, some examples are given of the application of these results to surface imaging. (author) [fr

NREL Spectrum of Clean Energy Innovation: Issue 3 (Book)

Energy Technology Data Exchange (ETDEWEB)

2012-11-01

This quarterly magazine is dedicated to stepping beyond the technical journals to reveal NREL's vital work in a real-world context for our stakeholders. Continuum provides insights into the latest and most impactful clean energy innovations, while spotlighting those talented researchers and unique facilities that make it all happen. This edition focuses on the NREL Spectrum of Clean Energy Innovation.

PERFORMANCE OPTIMIZATION OF COGNITIVE RADIO WITH WIDEBAND SPECTRUM SENSING

Directory of Open Access Journals (Sweden)

E. Saraniya

2014-09-01

Full Text Available Cognitive radio (CR technology allows the unlicensed user to access the licensed spectrum bands. Spectrum sensing is an essential function in cognitive radio to detect the spectrum holes and opportunistically use the underutilized frequency bands without causing interference to primary user (PU. In this paper we are maximizing the throughput capacity of cognitive radio user and hence the performance of spectrum sensing and protection to licensed user improves over a wideband spectrum sensing band. The simulation of cognitive radio is done by analyzing the performance of energy detector spectrum sensing technique to detect primary user and to formulate the optimization using multiband joint detection method (MJD to achieve suitable trade- off between secondary user access and primary user network. The main aim of this paper is to maximize the probability of detection and to decrease the probabilities of miss detection and false alarm. To maximize the throughput it requires minimizing the throughput loss caused by miss detection and the significant reduction in probability of false alarm helps in achieving the spectral efficiency from the secondary user’s perspective. The simulation results show that the performance increases with the MJD method.

Ground level enhancement (GLE) energy spectrum parameters model

Science.gov (United States)

Qin, G.; Wu, S.

2017-12-01

We study the ground level enhancement (GLE) events in solar cycle 23 with the four energy spectra parameters, the normalization parameter C, low-energy power-law slope γ 1, high-energy power-law slope γ 2, and break energy E0, obtained by Mewaldt et al. 2012 who fit the observations to the double power-law equation. we divide the GLEs into two groups, one with strong acceleration by interplanetary (IP) shocks and another one without strong acceleration according to the condition of solar eruptions. We next fit the four parameters with solar event conditions to get models of the parameters for the two groups of GLEs separately. So that we would establish a model of energy spectrum for GLEs for the future space weather prediction.

Neutron energy spectrum influence on irradiation hardening and microstructural development of tungsten

Energy Technology Data Exchange (ETDEWEB)

Fukuda, Makoto, E-mail: makoto.fukuda@qse.tohoku.ac.jp [Tohoku University, Sendai, 980-8579 (Japan); Kiran Kumar, N.A.P.; Koyanagi, Takaaki; Garrison, Lauren M. [Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Snead, Lance L. [Massachusetts Institute of Technology, Cambridge, MA, 02139 (United States); Katoh, Yutai [Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Hasegawa, Akira [Tohoku University, Sendai, 980-8579 (Japan)

2016-10-15

Neutron irradiation to single crystal pure tungsten was performed in the mixed spectrum High Flux Isotope Reactor (HFIR). To investigate the influences of neutron energy spectrum, the microstructure and irradiation hardening were compared with previous data obtained from the irradiation campaigns in the mixed spectrum Japan Material Testing Reactor (JMTR) and the sodium-cooled fast reactor Joyo. The irradiation temperatures were in the range of ∼90–∼800 °C and fast neutron fluences were 0.02–9.00 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV). Post irradiation evaluation included Vickers hardness measurements and transmission electron microscopy. The hardness and microstructure changes exhibited a clear dependence on the neutron energy spectrum. The hardness appeared to increase with increasing thermal neutron flux when fast fluence exceeds 1 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV). Irradiation induced precipitates considered to be χ- and σ-phases were observed in samples irradiated to >1 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV), which were pronounced at high dose and due to the very high thermal neutron flux of HFIR. Although the irradiation hardening mainly caused by defects clusters in a low dose regime, the transmutation-induced precipitation appeared to impose additional significant hardening of the tungsten. - Highlights: • The microstructure and irradiation hardening of single crystal pure W irradiated in HFIR was investigated. • The neutron energy spectrum influence was evaluated by comparing the HFIR results with previous work in Joyo and JMTR. • In the dose range up to ∼1 dpa, the neutron energy spectrum influence of irradiation hardening was not clear. • In the dose range above 1 dpa, the neutron energy influence on irradiation hardening and microstructural development was clearly observed. • The irradiation induced precipitates caused significant irradiation hardening of pure W irradiated in HFIR.

The energy spectrum of cosmic rays measured with the HEAT extension at the Pierre Auger Observatory

International Nuclear Information System (INIS)

Scharf, Nils Sven Sebastian

2013-01-01

This thesis describes the calculation of the energy spectrum of cosmic rays, that is the absolute flux of cosmic rays as a function of energy, from data of air showers observed with the HEAT (High Elevation Auger Telescopes) extension and the fluorescence detector of the Pierre Auger Observatory. The Pierre Auger Observatory is the largest observatory for the study of cosmic rays. The Pierre Auger Observatory observes air showers, that are cascades of particles that were instigated by cosmic rays hitting the Earth's atmosphere, with two different detection concepts. The surface detector samples the secondary particles of air showers that hit the ground with an array of surface detector stations, whereas the fluorescence detector measures the energy loss profile of air showers by detecting fluorescence light, produced by the air showers when they travel through the atmosphere, with optical telescopes. The properties of the cosmic rays are not directly measurable but have to be reconstructed from the observed air shower parameters. Properties of particular interest are the type of the primary cosmic ray particle, its energy and its arrival direction. HEAT is an extension to the fluorescence detector of the Pierre Auger Observatory. It is designed to lower the energy threshold by one order of magnitude down to 10 17 eV or lower. HEAT is taking data since 2010. The calculation of the absolute flux of cosmic rays needs two ingredients: the number of detected air showers as a function of shower energy and the exposure of the detector as a function of energy. The studied air shower class are hybrid events, which are events that have been detected by a fluorescence detector and at least one surface detector station. The used air showers were observed in a time period of fifteen month starting from June 2010. A first step of the analysis is the reconstruction of air showers and cosmic ray parameters from raw data. To calculate the exposure, the uptime, that is the integral

The transition from primary to secondary school in mainstream education for children with autism spectrum disorder.

Science.gov (United States)

Mandy, William; Murin, Marianna; Baykaner, Ozlem; Staunton, Sara; Hellriegel, Josselyn; Anderson, Seonaid; Skuse, David

2016-01-01

The transition from primary to secondary education (hereafter 'school transition') is a major ecological shift that poses considerable social, emotional, academic and organisational challenges. It is commonly assumed that this school transition is especially difficult for children with autism spectrum disorder, but that idea is mainly based on anecdotal evidence and requires systematic investigation. We describe change and continuity for children with autism spectrum disorder (N = 28, mean age = 11.29 years, mean full-scale IQ = 87.86) transitioning in mainstream education from primary to secondary school. Levels of psychopathology, adaptive functioning and peer victimisation were measured by parent, self and teacher report in the last year of primary school, and again after one term of secondary school. At follow-up, all participants were still in their secondary school, and there was no evidence for a marked escalation of difficulties during the transition. Instead, we observed high levels of psychopathology and maladaption at baseline which persisted across the transition and were in some cases under-recognised. By parent report, levels of bullying fell from primary to secondary school. Future research should investigate factors, such as school characteristics, that influence the move to secondary education in autism spectrum disorder, to inform the development of interventions to promote successful school transition. © The Author(s) 2015.

Magnetic field effects on the quantum wire energy spectrum and Green's function

International Nuclear Information System (INIS)

Morgenstern Horing, Norman J.

2010-01-01

We analyze the energy spectrum and propagation of electrons in a quantum wire on a 2D host medium in a normal magnetic field, representing the wire by a 1D Dirac delta function potential which would support just a single subband state in the absence of the magnetic field. The associated Schroedinger Green's function for the quantum wire is derived in closed form in terms of known functions and the Landau quantized subband energy spectrum is examined.

New layout of time resolved beam energy spectrum measurement for dragon-I

International Nuclear Information System (INIS)

Liao Shuqing; Zhang Kaizhi; Shi Jinshui

2010-01-01

A new layout of time resolved beam energy spectrum measurement is proposed for Dragon-I by a new method named RBS (rotating beams in solenoids). The basic theory of RBS and the new layout are presented and the measuring error is also discussed. The derived time resolved beam energy spectrum is discrete and is determined by measuring the beam's rotating angle and expanding width through a group of solenoids at the export of Dragon-I. (authors)

Spectrum and energy levels of five-times ionized zirconium (Zr VI)

Science.gov (United States)

Reader, Joseph; Lindsay, Mark D.

2016-02-01

We carried out a new analysis of the spectrum of five-times-ionized zirconium Zr VI. For this we used sliding-spark discharges together with normal- and grazing-incidence spectrographs to observe the spectrum from 160 to 2000 Å. These observations showed that the analysis of this spectrum by Khan et al (1985 Phys. Scr. 31 837) contained a significant number of incorrect energy levels. We have now classified ˜420 lines as transitions between 23 even-parity levels 73 odd-parity levels. The 4s24p5, 4s4p6, 4s24p44d, 5s, 5d, 6s configurations are now complete, although a few levels of 4s24p45d are tentative. We determined Ritz-type wavelengths for ˜135 lines from the optimized energy levels. The uncertainties range from 0.0003 to 0.0020 Å. Hartree-Fock calculations and least-squares fits of the energy parameters to the observed levels were used to interpret the observed configurations. Oscillator strengths for all classified lines were calculated with the fitted parameters. The results are compared with values for the level energies, percentage compositions, and transition probabilities from recent ab initio theoretical calculations. The ionization energy was revised to 777 380 ± 300 cm-1 (96.38 ± 0.04 eV).

Application of thermoluminescence dosimeter on the measurement of hard X-ray pulse energy spectrum

International Nuclear Information System (INIS)

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

Energy spectrum measurement of high power and high energy(6 and 9 MeV) pulsed x-ray source for industrial use

Energy Technology Data Exchange (ETDEWEB)

Takagi, Hiroyuki [Hitachi, Ltd. Power Systems Company, Ibaraki (Japan); Murata, Isao [Graduate School of Engineering, Osaka University, Osaka (Japan)

2016-06-15

Industrial X-ray CT system is normally applied to non-destructive testing (NDT) for industrial product made from metal. Furthermore there are some special CT systems, which have an ability to inspect nuclear fuel assemblies or rocket motors, using high power and high energy (more than 6 MeV) pulsed X-ray source. In these case, pulsed X-ray are produced by the electron linear accelerator, and a huge number of photons with a wide energy spectrum are produced within a very short period. Consequently, it is difficult to measure the X-ray energy spectrum for such accelerator-based X-ray sources using simple spectrometry. Due to this difficulty, unexpected images and artifacts which lead to incorrect density information and dimensions of specimens cannot be avoided in CT images. For getting highly precise CT images, it is important to know the precise energy spectrum of emitted X-rays. In order to realize it we investigated a new approach utilizing the Bayesian estimation method combined with an attenuation curve measurement using step shaped attenuation material. This method was validated by precise measurement of energy spectrum from a 1 MeV electron accelerator. In this study, to extend the applicable X-ray energy range we tried to measure energy spectra of X-ray sources from 6 and 9 MeV linear accelerators by using the recently developed method. In this study, an attenuation curves are measured by using a step-shaped attenuation materials of aluminum and steel individually, and the each X-ray spectrum is reconstructed from the measured attenuation curve by the spectrum type Bayesian estimation method. The obtained result shows good agreement with simulated spectra, and the presently developed technique is adaptable for high energy X-ray source more than 6 MeV.

Spectrum and energy levels of kryptonlike ion Nb VI

International Nuclear Information System (INIS)

Reader, J.; Ekberg, J.O.

1993-01-01

The spectrum of five-times ionized niobium, Nb, VI, was observed from 238 to 2700 angstrom with sliding spark discharges on 10.7-m normal- and grazing-incidence spectrographs. Experimental energies were determined for all levels of the 4s 2 4p 6 , 4s 2 4p 6 , 4s 2 4p 5 4d, 4f, 5s, 5p, 5g, 6s, and 4s4p 6 4d configurations as well as some levels of 4p 5 6g. A total of 291 lines were classified as transitions between 88 observed levels. A previous analysis of this spectrum was found to be totally erroneous. Large hyperfine splittings were found for several levels of the 4p 5 5s and 5p configurations. The observed configurations were theoretically interpreted by means of Hartree-Fock calculations and least squares fits of the energy parameters to the observed levels. A revised value of the ionization energy was obtained from the 4p 5 5g and 6g configurations

Algorithm for removing the noise from γ energy spectrum by analyzing the evolution of the wavelet transform maxima across scales

International Nuclear Information System (INIS)

Li Tianduo; Xiao Gang; Di Yuming; Han Feng; Qiu Xiaoling

1999-01-01

The γ energy spectrum is expanded in allied energy-frequency space. By the different characterization of the evolution of wavelet transform modulus maxima across scales between energy spectrum and noise, the algorithm for removing the noise from γ energy spectrum by analyzing the evolution of the wavelet transform maxima across scales is presented. The results show, in contrast to the methods in energy space or in frequency space, the method has the advantages that the peak of energy spectrum can be indicated accurately and the energy spectrum can be reconstructed with a good approximation

Spectrum-energy Correlations in GRBs: Update, Reliability, and the Long/Short Dichotomy

Science.gov (United States)

Zhang, Z. B.; Zhang, C. T.; Zhao, Y. X.; Luo, J. J.; Jiang, L. Y.; Wang, X. L.; Han, X. L.; Terheide, R. K.

2018-05-01

Spectrum-energy correlations of peak energy with total prompt γ-ray emission energies, namely {E}p,i-{E}{iso}, {E}p,i-{E}γ , and {E}p,i-{L}p, had been studied for long gamma-ray bursts (GRBs) previously by many authors. These energy correlations were proposed to measure the universe and classify GRBs as useful probes. However, most of these relations were built by non-Swift bursts. The spectrum-energy correlations of short bursts have not been systematically established yet; in particular, how the newly found GRB170817A matches these energy relations is unknown to date. We will first refresh the three spectrum-energy relations of Swift/BAT and Fermi/GBM long bursts and build the corresponding relations of short bursts. Then, we confirm whether they are commonly available as a discriminator of short and long GRBs. Some potential violators to these relations will be investigated. Combining with the plane of peak energy versus fluence, we select 31 short and 252 long GRBs with well-measured peak energy and redshift to study the issue of GRB classifications connected with the above energy relations statistically. We find that the three energy relations do exist in our new GRB samples and they are marginally consistent with some previous results. We report for the first time that short GRBs hold the three corresponding energy relations having the consistent power-law indices with long GRBs. It is found that these energy relations can be adopted to discriminate GRBs successfully if they are put in the peak energy versus fluence plane. Excitingly, we point out that GRB090510 matches the energy relations of {E}p,i-{E}{iso} and {E}p,i-{L}p, but violates the {E}p,i-{E}γ relation. More excitingly, we find that GRB170817A is an outlier to all the three energy correlations.

Energy spectra of primary knock-on atoms under neutron irradiation

International Nuclear Information System (INIS)

Gilbert, M.R.; Marian, J.; Sublet, J.-Ch.

2015-01-01

Materials subjected to neutron irradiation will suffer from a build-up of damage caused by the displacement cascades initiated by nuclear reactions. Previously, the main “measure” of this damage accumulation has been through the displacements per atom (dpa) index, which has known limitations. This paper describes a rigorous methodology to calculate the primary atomic recoil events (often called the primary knock-on atoms or PKAs) that lead to cascade damage events as a function of energy and recoiling species. A new processing code SPECTRA-PKA combines a neutron irradiation spectrum with nuclear recoil data obtained from the latest nuclear data libraries to produce PKA spectra for any material composition. Via examples of fusion relevant materials, it is shown that these PKA spectra can be complex, involving many different recoiling species, potentially differing in both proton and neutron number from the original target nuclei, including high energy recoils of light emitted particles such as α-particles and protons. The variations in PKA spectra as a function of time, neutron field, and material are explored. The application of PKA spectra to the quantification of radiation damage is exemplified using two approaches: the binary collision approximation and stochastic cluster dynamics, and the results from these different models are discussed and compared. - Highlights: • Recoil cross-section matrices under neutron irradiation are generated. • Primary knock-on atoms (PKA) spectra are calculated for fusion relevant materials. • Variation in PKA spectra due to changes in geometry are considered. • Inventory simulations to consider time-evolution in PKA spectra. • Damage quantification using damage functions from different approximations.

Scaling-law for the energy dependence of anatomic power spectrum in dedicated breast CT

Energy Technology Data Exchange (ETDEWEB)

Vedantham, Srinivasan; Shi, Linxi; Glick, Stephen J.; Karellas, Andrew [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States)

2013-01-15

Purpose: To determine the x-ray photon energy dependence of the anatomic power spectrum of the breast when imaged with dedicated breast computed tomography (CT). Methods: A theoretical framework for scaling the empirically determined anatomic power spectrum at one x-ray photon energy to that at any given x-ray photon energy when imaged with dedicated breast CT was developed. Theory predicted that when the anatomic power spectrum is fitted with a power curve of the form k f{sup -{beta}}, where k and {beta} are fit coefficients and f is spatial frequency, the exponent {beta} would be independent of x-ray photon energy (E), and the amplitude k scales with the square of the difference in energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues. Twenty mastectomy specimens based numerical phantoms that were previously imaged with a benchtop flat-panel cone-beam CT system were converted to 3D distribution of glandular weight fraction (f{sub g}) and were used to verify the theoretical findings. The 3D power spectrum was computed in terms of f{sub g} and after converting to linear attenuation coefficients at monoenergetic x-ray photon energies of 20-80 keV in 5 keV intervals. The 1D power spectra along the axes were extracted and fitted with a power curve of the form k f{sup -{beta}}. The energy dependence of k and {beta} were analyzed. Results: For the 20 mastectomy specimen based numerical phantoms used in the study, the exponent {beta} was found to be in the range of 2.34-2.42, depending on the axis of measurement. Numerical simulations agreed with the theoretical predictions that for a power-law anatomic spectrum of the form k f{sup -{beta}}, {beta} was independent of E and k(E) =k{sub 1}[{mu}{sub g}(E) -{mu}{sub a}(E)]{sup 2}, where k{sub 1} is a constant, and {mu}{sub g}(E) and {mu}{sub a}(E) represent the energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues, respectively. Conclusions: Numerical

Gamma spectrum following neutron capture in {sup 167}Er

Energy Technology Data Exchange (ETDEWEB)

Visser, D.; Khoo, T.L.; Lister, C.J. [and others

1995-08-01

Statistical decay from a highly excited state samples all the lower-lying states and, hence, provides a sensitive measure of the level density. Pairing has a major impact on the level density, e.g. creating a pair gap between the 0- and 2-quasiparticle configurations. Hence the shape of the statistical spectrum contains information on pairing, and can be used to provide information on the reduction of pairing with thermal excitation energy. For this reason, we measured the complete spectrum of {gamma}rays following thermal neutron capture in {sup 167}Er. The experiment was performed at the Brookhaven reactor using Compton-suppressed Ge detectors from TESSA. The spectrum, which was corrected for detector response and efficiency, reveals primary (first-step, high-energy) transitions up to nearly 8 MeV, secondary (last-step, lower-energy) transitions, as we as a continuous statistical component. Effort was expanded to identify all lines from contaminant sources and an upper limit of 5% was tentatively set for their contributions. The spectral shape of the statistical spectrum will be compared with theoretical spectra obtained from a calculation of pairing which accounts for a stepwise reduction of the pair correlations as the number of quasiparticles increases. The primary lines which decay directly to the near-yrast states will also be used to deduce the level densities.

Spectrum and energy levels of five-times ionized zirconium (Zr VI)

International Nuclear Information System (INIS)

Reader, Joseph; Lindsay, Mark D

2016-01-01

We carried out a new analysis of the spectrum of five-times-ionized zirconium Zr VI. For this we used sliding-spark discharges together with normal- and grazing-incidence spectrographs to observe the spectrum from 160 to 2000 Å. These observations showed that the analysis of this spectrum by Khan et al (1985 Phys. Scr. 31 837) contained a significant number of incorrect energy levels. We have now classified ∼420 lines as transitions between 23 even-parity levels 73 odd-parity levels. The 4s 2 4p 5 , 4s4p 6 , 4s 2 4p 4 4d, 5s, 5d, 6s configurations are now complete, although a few levels of 4s 2 4p 4 5d are tentative. We determined Ritz-type wavelengths for ∼135 lines from the optimized energy levels. The uncertainties range from 0.0003 to 0.0020 Å. Hartree–Fock calculations and least-squares fits of the energy parameters to the observed levels were used to interpret the observed configurations. Oscillator strengths for all classified lines were calculated with the fitted parameters. The results are compared with values for the level energies, percentage compositions, and transition probabilities from recent ab initio theoretical calculations. The ionization energy was revised to 777 380 ± 300 cm −1 (96.38 ± 0.04 eV). (paper)

Reflection of the energy structure of a tungsten monocrystal nearsurface area in the secondary electron spectrum

International Nuclear Information System (INIS)

Artamonov, O.M.; Smirnov, O.M.; Terekhov, A.N.

1982-01-01

Formation of secondary electron energy spectrum during emission from the crystal layer near the surface has been considered, at that layer energy structure can be different from volumetric energy structure. Its thickness depends on the predominant mechanism of electron scattering and is determined by corresponding phenomenological parameters. It is shown that the structure in the secondary electron spectrum appears in the case when energy structure of emitting monocrystal layer can not be described in the approximation of almost free electron gas and, as experimental investigations show, approaches energy zone structure of its volume. It is also show that in the case when the energy structure of the emitting layer is satisfactorily described with the model of almost free electron gas, the SE spectrum is characterized with traditional cascade minimum. Experimental investigation of SE energy distribution was carried out for the W monocrystalline face (110). It was established that distinct structure in the SE spectrum appears only after electrochemical polishing of the specimen surface. It is related to the appearance of ''far'' order in the monocrystal emission layer on initially disturbed tungsten surface during such treatment. Disturbance of tungsten monocrystal surface structure on its oxidation in O 2 atmosphere results in the appearance of the cascade maximum and disappearance of distinct peculiarities in the SE spectrum

Relaxation of ion energy spectrum just after turbulent heating pulse in TRIAM-1 tokamak

International Nuclear Information System (INIS)

Nakamura, Kazuo; Hiraki, Naoji; Nakamura, Yukio; Itoh, Satoshi

1982-01-01

The temporal evolution and spatial profile of the ion energy spectrum just after the application of a toroidal current pulse for turbulent heating are investigated experimentally in the TRIAM-1 tokamak and also numerically using the Fokker-Planck equation. The two-component ion energy spectrum formed by turbulent heating relaxes to a single one within tausub(i) (the ion collision time). (author)

Relaxation of ion energy spectrum just after turbulent heating pulse in TRIAM-1 tokamak

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Kazuo; Hiraki, Naoji; Nakamura, Yukio; Itoh, Satoshi [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

1982-07-01

The temporal evolution and spatial profile of the ion energy spectrum just after the application of a toroidal current pulse for turbulent heating are investigated experimentally in the TRIAM-1 tokamak and also numerically using the Fokker-Planck equation. The two-component ion energy spectrum formed by turbulent heating relaxes to a single one within tausub(i) (the ion collision time).

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

KAUST Repository

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

The application of thermoluminescence dosimeter on the measurement of hard X-ray pulse energy spectrum

International Nuclear Information System (INIS)

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

Third-Order Density Perturbation and One-Loop Power Spectrum in Dark-Energy-Dominated Universe

OpenAIRE

Takahashi, Ryuichi

2008-01-01

We investigate the third-order density perturbation and the one-loop correction to the linear power spectrum in the dark-energy cosmological model. Our main interest is to understand the dark-energy effect on baryon acoustic oscillations in a quasi-nonlinear regime ($k \\approx 0.1h$/Mpc). Analytical solutions and simple fitting formulae are presented for the dark-energy model with the general time-varying equation of state $w(a)$. It turns out that the power spectrum coincides with the approx...

Photon energy spectrum in B →Xs + γ and comparison with data

International Nuclear Information System (INIS)

Ali, A.; Greub, C.

1995-06-01

A comparison of the inclusive photon energy spectrum in the radiative decay B→X s +γ; measured recently by the CLEO collaboration, with the standard model is presented, using a B-meson wave function model and improving earlier perturbative QCD-based computations of the same. The dependence of the photon energy spectrum on the non-perturbative model parameters, p F , the b-quark Fermi momentum in the B hadron, and m q , the spectator quark mass, is explicitly shown, allowing a comparison of these parameters with the ones obtained from the analysis of the lepton energy spectrum in semileptonic B decays. Taking into account present uncertainties, we estimate BR(B→X s +γ)=(2.55±1.28)x10 -4 in the standard model, assuming vertical stroke V ts vertical stroke /vertical stroke V cb vertical stroke =1.0. Comparing this with CLEO measurement BR(B→X s +γ)=(2.32±0.67)x10 -4 implies vertical stroke V ts vertical stroke /vertical stroke V cb vertical stroke =1.1±0.43, in agreement with the CKM unitarity. (orig.)

Autism Spectrum Disorder: Primary Care Principles.

Science.gov (United States)

Sanchack, Kristian E; Thomas, Craig A

2016-12-15

Autism spectrum disorder is characterized by difficulty with social communication and restricted, repetitive patterns of behavior, interest, or activities. The Diagnostic and Statistical Manual of Mental Disorders, 5th ed., created an umbrella diagnosis that includes several previously separate conditions: autistic disorder, Asperger syndrome, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified. There is insufficient evidence to recommend screening for autism spectrum disorder in children 18 to 30 months of age in whom the disorder is not suspected; however, there is a growing body of evidence that early intensive behavioral intervention based on applied behavior analysis improves cognitive ability, language, and adaptive skills. Therefore, early identification of autism spectrum disorder is important, and experts recommend the use of a validated screening tool at 18- and 24-month well-child visits. Medications can be used as adjunctive treatment for maladaptive behaviors and comorbid psychiatric conditions, but there is no single medical therapy that is effective for all symptoms of autism spectrum disorder. Prognosis is heavily affected by the severity of diagnosis and the presence of intellectual disability. Children with optimal outcomes receive earlier, more intensive behavioral interventions and less pharmacologic treatment.

Nuclear energy ranks first as primary energy source in Europe in 2012

International Nuclear Information System (INIS)

Anon.

2014-01-01

According to the 2012 report of Eurostat, nuclear energy represents 30% of the production of primary energy in the member states of the E.U., renewable energies a little less than 20% and fossil energies a little more than 50%. In Europe the production of primary energy has been decreasing since 2001, from 940 million tonnes in 2001 to 794 million tonnes in 2012. In Europe the gross energy consumption has decreased in 24 member states to reach the level of 1995 year. In 2012 the E.U.'s dependence rate for energy was of 53% on average. Only Denmark was a net exporter of energy while the dependence rate for energy of the main E.U. energy consumers were: Germany (61%), Spain (73%), France (48%), United-Kingdom (42%) and Italy (81%). (A.C.)

SLC energy spectrum monitor using synchrotron radiation

International Nuclear Information System (INIS)

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

SLC energy spectrum monitor using synchrotron radiation

International Nuclear Information System (INIS)

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

The e− Spectrum and e+ Spectrum from AMS

CERN Multimedia

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.

Primary energy implications of different design strategies for an apartment building

International Nuclear Information System (INIS)

Tettey, Uniben Yao Ayikoe; Dodoo, Ambrose; Gustavsson, Leif

2016-01-01

In this study, we explored the effects of different design strategies on final and primary energy use for production and operation of a newly constructed apartment building. We analysed alternatives of the building “As built” as well as to energy efficiency levels of the Swedish building code and passive house criteria. Our approach is based on achieving improved versions of the building alternatives from combination of design strategies giving the lowest space heating and cooling demand and primary energy use, respectively. We found that the combination of design strategies resulting in the improved building alternatives varies depending on the approach. The improved building alternatives gave up to 19–34% reduction in operation primary energy use compared to the initial alternatives. The share of production primary energy use of the improved building alternatives was 39–54% of the total primary energy use for production, space heating, space cooling and ventilation over 50-year lifespan, compared to 31–42% for the initial alternatives. This study emphasises the importance of incorporating appropriate design strategies to reduce primary energy use for building operation and suggests that combining such strategies with careful choice of building frame materials could result in significant primary energy savings in the built environment. - Highlights: • Primary energy implications of different design strategies were analysed. • The improved building alternatives had 19–34% lower operation primary energy use. • The improved building alternatives had higher production primary energy use. • Still, the improved building alternatives had lower overall primary energy use. • Design strategies should be combined with careful building frame material choice.

Cosmic ray spectrum and composition from three years of IceTop and IceCube

Science.gov (United States)

Rawlins, K.; IceCube Collaboration

2016-05-01

IceTop is the surface component of the IceCube Observatory, composed of frozen water tanks at the top of IceCube’s strings. Data from this detector can be analyzed in different ways with the goal of measuring cosmic ray spectrum and composition. The shower size S125 from IceTop alone can be used as a proxy for primary energy, and unfolded into an all-particle spectrum. In addition, S125 from the surface can be combined with high-energy muon energy loss information from the deep IceCube detector for those air showers which pass through both. Using these coincident events in a complementary analysis, both the spectrum and mass composition of primary cosmic rays can be extracted in parallel using a neural network. Both of these analyses have been performed on three years of IceTop and IceCube data. Both all-particle spectra as well as individual spectra for elemental groups are presented.

Measurement of the energy spectrum of cosmic rays from the Pierre Auger Observatory

International Nuclear Information System (INIS)

Roth, M.

2009-01-01

The large sample of data collected by the Pierre Auger Observatory has led to a significant improvement over previous measurements on the energy spectrum of cosmic rays. We observe a suppression of the flux at the highest energy with a significance of more than 6 standard deviations. The spectral index γ of the flux, J∝E -γ , at energies between 4x10 18 eV and 4x10 19 eV is 2.69±0.02 (stat) ±0.06 (syst), steepening to 4.2±0.4 (stat) ±0.06 (syst) at higher energies, consistent with the prediction by Greisen and by Zatsepin and Kuz'min. Observations of cosmic rays by the fluorescence detector allowed the extension of the energy spectrum to lower energies, where the efficiency of the surface detector is less then 100% and a change in the spectral index is expected.

Explanation of the Knee-like Feature in the DAMPE Cosmic {e}^{-}+{e}^{+} Energy Spectrum

Science.gov (United States)

Fang, Kun; Bi, Xiao-Jun; Yin, Peng-Fei

2018-02-01

The DArk Matter Particle Explorer, a space-based high precision cosmic-ray detector, has just reported the new measurement of the total electron plus positron energy spectrum up to 4.6 TeV. A notable feature in the spectrum is the spectral break at ∼0.9 TeV, with the spectral index softening from ‑3.1 to ‑3.9. Such a feature is very similar to the knee at the cosmic nuclei energy spectrum. In this work, we propose that the knee-like feature can be explained naturally by assuming that the electrons are accelerated at the supernova remnants (SNRs) and released when the SNRs die out with lifetimes around 105 years. The cut-off energy of those electrons have already decreased to several TeV due to radiative cooling, which may induce the observed TeV spectral break. Another possibility is that the break is induced by a single nearby old SNR. Such a scenario may bring a large electron flux anisotropy that may be observable by the future detectors. We also show that a minor part of electrons escaping during the acceleration in young and nearby SNRs is able to contribute to a several TeV or higher energy region of the spectrum.

Electron photon spectra at atmospheric depths 260 and 400 gm/cm2 derived from the Goddard primary proton spectrum using Fermilab data and usual cascade theory

International Nuclear Information System (INIS)

Bhattacharyya, D.P.; Gautam, V.P.

1982-01-01

The integral electron photon spectra of cosmic rays at airplane altitude and Lenin Peak (altitudes 260 and 400 g-cm -2 air) have been estimated from the primary proton spectrum of Goddard Space Flight Group using Fermilab data of pp→π +- +X and conventional cascade theory. The derived electron-photon spectra fits well the experimental data of Ohta et al. (1975) and Cherdyntseva and Nikol'skii (1976) for energies above 4 TeV

Measurement of the energy spectrum of cosmic-ray induced neutrons aboard an ER-2 high-altitude airplane

CERN Document Server

Goldhagen, P E; Kniss, T; Reginatto, M; Singleterry, R C; Van Steveninck, W; Wilson, J W

2002-01-01

Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from galactic cosmic radiation. Crews of future high-speed commercial aircraft flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the atmospheric ionizing radiation (AIR) project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on five flights of a NASA ER-2 high-altitude aircraft. The primary AIR instrument was a highly sensitive extended-energy multisphere neutron spectrometer with lead and steel shells placed within the moderators of two of its 14 detectors to enhance response at high energies. Detector responses were calculated for neutrons and charged hadrons at energies up to 100 GeV using MCNPX. Neutron spectra were unfolded from the measured count rates using the new MAXED code. We have measured the cosmic-ray neutron spectrum (t...

Determination of the Spectral Index in the Fission Spectrum Energy Regime

Energy Technology Data Exchange (ETDEWEB)

Lee, Amy Sarah [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-16

Neutron reaction cross sections play a vital role in tracking the production and destruction of isotopes exposed to neutron fluence. They are central to the process of reconciling the initial and final atom inventories. Measurements of irradiated samples by radiochemical methods in tangent with an algorithm are used to evaluate the fluence a sample is exposed to over the course of the irradiation. This algorithm is the Isotope Production Code (IPC) created and used by the radiochemistry data assessment team at Los Alamos National Laboratory (LANL). An integral result is calculated by varying the total neutron fluence seen by a sample. A sample, irradiated in a critical assembly, will be exposed to a unique neutron flux defined by the neutron source and distance of the sample from the source. Neutron cross sections utilized are a function of the hardness of the neutron spectrum at the location of irradiation. A spectral index is used an indicator of the hardness of the neutron spectrum. Cross sections fit forms applied in IPC are collapsed from a LANL 30-group energy structure. Several decades of research and development have been performed to formalize the current IPC cross section library. Basis of the current fission spectrum neutron reaction cross section library is rooted in critical assembly experiments performed from the 1950’s through the early 1970’s at LANL. The focus of this report is development of the spectral index used an indicator of the hardness of the neutron spectrum in the fission spectrum energy regime.

Possible dark energy imprints in the gravitational wave spectrum of mixed neutron-dark-energy stars

Energy Technology Data Exchange (ETDEWEB)

Yazadjiev, Stoytcho S. [Department of Theoretical Physics, Faculty of Physics, St. Kliment Ohridski University of Sofia, James Bourchier Blvd. 5, 1164 Sofia (Bulgaria); Doneva, Daniela D., E-mail: yazad@phys.uni-sofia.bg, E-mail: daniela.doneva@uni-tuebingen.de [Theoretical Astrophysics, IAAT, Eberhard-Karls University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen (Germany)

2012-03-01

In the present paper we study the oscillation spectrum of neutron stars containing both ordinary matter and dark energy in different proportions. Within the model we consider, the equilibrium configurations are numerically constructed and the results show that the properties of the mixed neuron-dark-energy star can differ significantly when the amount of dark energy in the stars is varied. The oscillations of the mixed neuron-dark-energy stars are studied in the Cowling approximation. As a result we find that the frequencies of the fundamental mode and the higher overtones are strongly affected by the dark energy content. This can be used in the future to detect the presence of dark energy in the neutron stars and to constrain the dark-energy models.

Direct measurement of the partial decay energy of 7Be inner bremstrahlung spectrum

International Nuclear Information System (INIS)

Sanjeeviah, H.; Sanjeeviah, B.

1978-01-01

The inner bremsstrahlung spectrum accompanying orbital electron capture decay of 7 Be to the first excited state of 7 Li was measured in coincidence with 477 keV gamma rays. From the Jauch plot of the spectrum the partial decay energy was found to be 394 +- 16 keV. The shape factor of the inner bremsstrahlung spectrum close to the end point was accurately determined. It was found to be a constant X(1.001 +- 0.002) (author)

Measurement of the atmospheric νμ energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope

International Nuclear Information System (INIS)

Adrian-Martinez, S.; Ardid, M.; Larosa, G.; Martinez-Mora, J.A.; Albert, A.; Drouhin, D.; Racca, C.; Al Samarai, I.; Aubert, J.J.; Bertin, V.; Brunner, J.; Busto, J.; Carr, J.; Charif, Z.; Core, L.; Costantini, H.; Coyle, P.; Curtil, C.; Dornic, D.; Ernenwein, J.P.; Escoffier, S.; Lambard, E.; Riviere, C.; Vallee, C.; Yatkin, K.; Andre, M.; Anghinolfi, M.; Sanguineti, M.; Anton, G.; Classen, F.; Eberl, T.; Enzenhoefer, A.; Fehn, K.; Folger, F.; Fritsch, U.; Geisselsoeder, S.; Geyer, K.; Gleixner, A.; Graf, K.; Herold, B.; Hoessl, J.; James, C.W.; Kalekin, O.; Kappes, A.; Katz, U.; Lahmann, R.; Motz, H.; Neff, M.; Richter, R.; Roensch, K.; Schmid, J.; Schnabel, J.; Seitz, T.; Shanidze, R.; Sieger, C.; Spies, A.; Wagner, S.; Anvar, S.; Louis, F.; Astraatmadja, T.; Bogazzi, C.; Bouwhuis, M.C.; Heijboer, A.J.; Jong, M. de; Michael, T.; Palioselitis, D.; Schulte, S.; Steijger, J.J.M.; Visser, E.; Baret, B.; Bouhou, B.; Creusot, A.; Galata, S.; Kouchner, A.; Elewyck, V. van; Barrios-Marti, J.; Bigongiari, C.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Lambard, G.; Mangano, S.; Sanchez-Losa, A.; Yepes, H.; Zornoza, J.D.; Zuniga, J.; Basa, S.; Marcelin, M.; Nezri, E.; Biagi, S.; Fusco, L.A.; Giacomelli, G.; Margiotta, A.; Spurio, M.; Bruijn, R.; Decowski, M.P.; Wolf, E. de; Capone, A.; De Bonis, G.; Fermani, P.; Perrina, C.; Simeone, F.; Caramete, L.; Pavalas, G.E.; Popa, V.; Carloganu, C.; Dumas, A.; Gay, P.; Guillard, G.; Cecchini, S.; Chiarusi, T.; Charvis, P.; Deschamps, A.; Hello, Y.; Circella, M.; Dekeyser, I.; Lefevre, D.; Martini, S.; Robert, A.; Tamburini, C.; Distefano, C.; Lattuada, D.; Piattelli, P.; Sapienza, P.; Trovato, A.; Donzaud, C.; Dorosti, Q.; Loehner, H.; Flaminio, V.; Giordano, V.; Haren, H. van; Kadler, M.; Kooijman, P.; Kreykenbohm, I.; Mueller, C.; Wilms, J.; Kulikovskiy, V.; Leonora, E.; Lo Presti, D.; Loucatos, S.; Schuessler, F.; Stolarczyk, T.; Vallage, B.; Vernin, P.; Montaruli, T.; Morganti, M.; Pradier, T.; Rostovtsev, A.; Samtleben, D.F.E.; Taiuti, M.; Tayalati, Y.

2013-01-01

Atmospheric neutrinos are produced during cascades initiated by the interaction of primary cosmic rays with air nuclei. In this paper, a measurement of the atmospheric ν μ + anti ν μ energy spectrum in the energy range 0.1-200 TeV is presented, using data collected by the ANTARES underwater neutrino telescope from 2008 to 2011. Overall, the measured flux is ∝25 % higher than predicted by the conventional neutrino flux, and compatible with the measurements reported in ice. The flux is compatible with a single power-law dependence with spectral index γ meas =3.58±0.12. With the present statistics the contribution of prompt neutrinos cannot be established. (orig.)

An Energy-Efficient Game-Theory-Based Spectrum Decision Scheme for Cognitive Radio Sensor Networks.

Science.gov (United States)

Salim, Shelly; Moh, Sangman

2016-06-30

A cognitive radio sensor network (CRSN) is a wireless sensor network in which sensor nodes are equipped with cognitive radio. In this paper, we propose an energy-efficient game-theory-based spectrum decision (EGSD) scheme for CRSNs to prolong the network lifetime. Note that energy efficiency is the most important design consideration in CRSNs because it determines the network lifetime. The central part of the EGSD scheme consists of two spectrum selection algorithms: random selection and game-theory-based selection. The EGSD scheme also includes a clustering algorithm, spectrum characterization with a Markov chain, and cluster member coordination. Our performance study shows that EGSD outperforms the existing popular framework in terms of network lifetime and coordination overhead.

An Evaluation of Neutron Energy Spectrum Effects in Iron Based on Molecular Dynamics Displacement Cascade Simulations

International Nuclear Information System (INIS)

Greenwood, L.R.; Stoller, R.E.

1998-01-01

The results of molecular dynamics (MD) displacement cascade simulations in bcc iron have been used to obtain effective cross sections for two measures of primary damage production: (1) the number of surviving point defects expressed as a fraction of the displacements calculated using the standard secondary displacement model of Norgett, Robinson, and Torrens (NRT), and (2) the fraction of the surviving interstitials contained in clusters that formed during the cascade event. Primary knockon atom spectra for iron obtained from the SPECTER code have been used to weight these MD-based damage production cross sections in order to obtain spectrally-averaged values for several locations in commercial fission reactors and materials test reactors. An evaluation of these results indicates that neutron energy spectrum differences between the various enviromnents do not lead to significant differences between the average primary damage formation parameters. In particular, the defect production cross sections obtained for PWR and BWR neutron spectra were not significantly different. The variation of the defect production cross sections as a function of depth into the reactor pressure vessel wall is used as a sample application of the cross sections. A slight difference between the attenuation behavior of the PWR and BWR was noted; this difference could be explained by a subtle difference in the energy dependence of the neutron spectra. Overall, the simulations support the continued use of dpa as a damage correlation parameter

Continuous energy Neutron Transport Monte Carlo Simulator Project: Decomposition of the neutron energy spectrum by target nuclei tagging

Energy Technology Data Exchange (ETDEWEB)

Barcellos, Luiz Felipe F.C.; Bodmann, Bardo E.J.; Vilhena, Marco T.M.B., E-mail: luizfelipe.fcb@gmail.com, E-mail: bardo.bodmann@ufrgs.br, E-mail: mtmbvilhena@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Grupo de Estudos Nucleares; Leite, Sergio Q. Bogado, E-mail: sbogado@ibest.com.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2017-07-01

In this work a Monte Carlo simulator with continuous energy is used. This simulator distinguishes itself by using the sum of three probability distributions to represent the neutron spectrum. Two distributions have known shape, but have varying population of neutrons in time, and these are the fission neutron spectrum (for high energy neutrons) and the Maxwell-Boltzmann distribution (for thermal neutrons). The third distribution has an a priori unknown and possibly variable shape with time and is determined from parametrizations of Monte Carlo simulation. It is common practice in neutron transport calculations, e.g. multi-group transport, to consider that the neutrons only lose energy with each scattering reaction and then to use a thermal group with a Maxwellian distribution. Such an approximation is valid due to the fact that for fast neutrons up-scattering occurrence is irrelevant, being only appreciable at low energies, i.e. in the thermal energy region, in which it can be regarded as a Maxwell-Boltzmann distribution for thermal equilibrium. In this work the possible neutron-matter interactions are simulated with exception of the up-scattering of neutrons. In order to preserve the thermal spectrum, neutrons are selected stochastically as being part of the thermal population and have an energy attributed to them taken from a Maxwellian distribution. It is then shown how this procedure can emulate the up-scattering effect by the increase in the neutron population kinetic energy. Since the simulator uses tags to identify the reactions it is possible not only to plot the distributions by neutron energy, but also by the type of interaction with matter and with the identification of the target nuclei involved in the process. This work contains some preliminary results obtained from a Monte Carlo simulator for neutron transport that is being developed at Federal University of Rio Grande do Sul. (author)

Primary Energy of the District city and Suburb

Science.gov (United States)

Pitonak, Anton; Lopusniak, Martin; Bagona, Miloslav

2017-10-01

In member states of the European Union, portion of buildings in the total consumption of energy represents 40 %, and their share in CO2 emissions represents 35 %. Taking into account the dependence of the European Union on import of energy, this represents a large quantity of energy and CO2 in spite of the fact that effective solutions for the reduction of energy demand of buildings exist. The European Union adopted three main commitments for fulfilment of criteria by year 2020 in the 20-20-20 Directive. Based on this Directive Slovakia declares support for renovating the building stock. The goal of the paper was to prove that renovation of the building stock is environmentally and energy preferably as construction of new buildings. In the paper, the settlement unit with the suburban one were compared. Both territories are dealt with in Kosice city, in Slovakia. The settlement units include apartment dwelling houses, amenities, parking areas and green. Suburban part contains family houses. The decisive factor for the final assessment of the buildings was global indicator. Global indicator of the energy performance is primary energy. The new building must meet minimum requirements for energy performance and it must be classified to energy class A1 since 2016, and to energy class A0 since 2020. The paper analyses the effects of the use of different resources of heat considering the global indicator. Primary energy was calculated and based on comparable unit. The primary energy was accounted for on the built-up area, area corresponding to district city and suburb, number of inhabitants. The study shows that the lowest values of global indicator are achieved by using wood. The highest values of global indicator are achieved by using electricity or district heating as an energy source. The difference between the highest and lowest value is 87 %. Primary energy based on inhabitant is 98 % lower in settlement unit compared to the suburban one.

An Energy-Efficient Game-Theory-Based Spectrum Decision Scheme for Cognitive Radio Sensor Networks

Directory of Open Access Journals (Sweden)

Shelly Salim

2016-06-01

Full Text Available A cognitive radio sensor network (CRSN is a wireless sensor network in which sensor nodes are equipped with cognitive radio. In this paper, we propose an energy-efficient game-theory-based spectrum decision (EGSD scheme for CRSNs to prolong the network lifetime. Note that energy efficiency is the most important design consideration in CRSNs because it determines the network lifetime. The central part of the EGSD scheme consists of two spectrum selection algorithms: random selection and game-theory-based selection. The EGSD scheme also includes a clustering algorithm, spectrum characterization with a Markov chain, and cluster member coordination. Our performance study shows that EGSD outperforms the existing popular framework in terms of network lifetime and coordination overhead.

Joint switched multi-spectrum and transmit antenna diversity for spectrum sharing systems

KAUST Repository

Sayed, Mostafa M.

2013-10-01

In spectrum sharing systems, a secondary user (SU) is allowed to share the spectrum with a primary (licensed) network under the condition that the interference observed at the receivers of the primary users (PU-Rxs) is below a predetermined level. In this paper, we consider a secondary network comprised of a secondary transmitter (SU-Tx) equipped with multiple antennas and a single-antenna secondary receiver (SU-Rx) sharing the same spectrum with multiple primary users (PUs), each with a distinct spectrum. We develop transmit antenna diversity schemes at the SU-Tx that exploit the multi-spectrum diversity provided by the existence of multiple PUs so as to optimize the signal-to-noise ratio (SNR) at the SU-Rx. In particular, assuming bounded transmit power at the SU-Tx, we develop switched selection schemes that select the primary spectrum and the SU-Tx transmit antenna that maintain the SNR at the SU-Rx above a specific threshold. Assuming Rayleigh fading channels and binary phase-shift keying (BPSK) transmission, we derive the average bit-error-rate (BER) and average feedback load expressions for the proposed schemes. For the sake of comparison, we also derive a BER expression for the optimal selection scheme that selects the best antenna/spectrum pair that maximizes the SNR at the SU-Rx, in exchange of high feedback load and switching complexity. Finally, we show that our analytical results are in perfect agreement with the simulation results. © 2013 IEEE.

Evolution of the Deep-space Galactic Cosmic Ray Lineal Energy Transfer Spectrum through Tissue Equivalent Plastic

Science.gov (United States)

Case, A. W.; Kasper, J. C.; Spence, H. E.; Golightly, M. J.; Schwadron, N. A.; Mazur, J. E.; Blake, J. B.; Looper, M. D.; Townsend, L.; Zeitlin, C. J.

2011-12-01

The Cosmic Ray Telescope for the Effects of Radiation is an energetic particle telescope that resides on the Lunar Reconnaissance Orbiter spacecraft, currently in a 50 km circular lunar polar orbit. The telescope consists of 6 silicon semi-conductor detectors placed in pairs that surround two pieces of Tissue Equivalent Plastic (TEP), which serve to absorb energy from particles as they transit through the instrument. Particles with energies greater than 12 MeV/nucleon can penetrate the outermost shield and be measured by the instrument. The primary measurement made by the instrument is of the Linear Energy Transfer (LET) of energetic particles as they transit through the telescope. CRaTER measures the LET spectrum with unprecedented energy resolution and has done so during a period of historically low solar activity that led to record high intensities of Galactic Cosmic Rays (GCR). These LET spectra are used to study changes in the properties of the incoming particles, and to make detailed measurements of the radiation doses human explorers will experience in deep space on missions to the moon, to asteroids, or to Mars. We present LET spectra accumulated during 2009 and 2010. We show how the LET spectrum evolves through the instrument as the GCR interact with the TEP. Due to the importance of these measurements for human effects, our extensive absolute calibration procedures are presented. Of particular note is a significant reduction in the flux of particles with LET greater than 10 keV/um for detectors that lie deeper within the telescope stack, due to the attenuation of high LET particles within the TEP. By measuring this attenuation we can estimate the depth in human tissue where the highest LET particles that are most likely to cause genetic damage pose the greatest threat to humans in space.

Cool covered sky-splitting spectrum-splitting FK

Energy Technology Data Exchange (ETDEWEB)

Mohedano, Rubén; Chaves, Julio; Falicoff, Waqidi; Hernandez, Maikel; Sorgato, Simone [LPI, Altadena, CA, USA and Madrid (Spain); Miñano, Juan C.; Benitez, Pablo [LPI, Altadena, CA, USA and Madrid, Spain and Universidad Politécnica de Madrid (UPM), Madrid (Spain); Buljan, Marina [Universidad Politécnica de Madrid (UPM), Madrid (Spain)

2014-09-26

Placing a plane mirror between the primary lens and the receiver in a Fresnel Köhler (FK) concentrator gives birth to a quite different CPV system where all the high-tech components sit on a common plane, that of the primary lens panels. The idea enables not only a thinner device (a half of the original) but also a low cost 1-step manufacturing process for the optics, automatic alignment of primary and secondary lenses, and cell/wiring protection. The concept is also compatible with two different techniques to increase the module efficiency: spectrum splitting between a 3J and a BPC Silicon cell for better usage of Direct Normal Irradiance DNI, and sky splitting to harvest the energy of the diffuse radiation and higher energy production throughout the year. Simple calculations forecast the module would convert 45% of the DNI into electricity.

Effects of fault heterogeneity on seismic energy and spectrum

Science.gov (United States)

Dragoni, Michele; Santini, Stefano

2017-12-01

We study the effects of friction heterogeneity on the dynamics of a seismogenic fault. To this aim, we consider a fault model containing two asperities with different static frictions and a rate-dependent dynamic friction. We consider the seismic events produced by the consecutive failure of the two asperities and study their properties as functions of the ratio between static frictions. In particular, we calculate the moment rate, the stress evolution during fault slip, the average stress drop, the partitioning of energy release, the seismic energy, the far-field waveforms and the spectrum of seismic waves. These quantities depend to various extent on the friction distribution on the fault. In particular, the stress distribution on the fault is always strongly heterogeneous at the beginning of the seismic event. Seismic energy and frictional heat decrease with increasing friction heterogeneity, while seismic efficiency is constant. We obtain an equation relating seismic efficiency to the parameters of the friction law, showing that the efficiency is maximum for smaller values of dynamic friction. The seismic spectrum depends on the friction distribution as to the positions and the values of the minima. However, under the model assumption that the slip durations are the same for both asperities, the corner frequency is independent of the friction distribution, but it depends on the friction law and on the coupling between asperities. The model provides a relation between the total radiated energy and the seismic moment that is consistent with the empirical relation between the two quantities. The fault model with one asperity is also considered as a particular case. The model is applied to the 1965 Rat Islands (Alaska) earthquake and shows the role of fault heterogeneity in controlling the spatial distribution of stress drop as well as the time dependence and the final amount of radiated energy.

The energy-momentum spectrum in local field theories with broken Lorentz-symmetry

International Nuclear Information System (INIS)

Borchers, H.J.; Buchholz, D.

1984-05-01

Assuming locality of the observables and positivity of the energy it is shown that the joint spectrum of the energy-momentum operators has a Lorentz-invariant lower boundary in all superselection sectors. This result is of interest if the Lorentz-symmetry is (spontaneously) broken, such as in the charged sectors of quantum electrodynamics. (orig.)

Measurement of the atmospheric {nu}{sub {mu}} energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope

Energy Technology Data Exchange (ETDEWEB)

Adrian-Martinez, S.; Ardid, M.; Larosa, G.; Martinez-Mora, J.A. [Universitat Politecnica de Valencia, Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Gandia (Spain); Albert, A.; Drouhin, D.; Racca, C. [GRPHE - Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit, BP 50568, Colmar (France); Al Samarai, I.; Aubert, J.J.; Bertin, V.; Brunner, J.; Busto, J.; Carr, J.; Charif, Z.; Core, L.; Costantini, H.; Coyle, P.; Curtil, C.; Dornic, D.; Ernenwein, J.P.; Escoffier, S.; Lambard, E.; Riviere, C.; Vallee, C.; Yatkin, K. [Aix-Marseille Universite, CPPM, CNRS/IN2P3, Marseille (France); Andre, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Vilanova i la Geltru, Barcelona (Spain); Anghinolfi, M.; Sanguineti, M. [INFN - Sezione di Genova, Genova (Italy); Anton, G.; Classen, F.; Eberl, T.; Enzenhoefer, A.; Fehn, K.; Folger, F.; Fritsch, U.; Geisselsoeder, S.; Geyer, K.; Gleixner, A.; Graf, K.; Herold, B.; Hoessl, J.; James, C.W.; Kalekin, O.; Kappes, A.; Katz, U.; Lahmann, R.; Motz, H.; Neff, M.; Richter, R.; Roensch, K.; Schmid, J.; Schnabel, J.; Seitz, T.; Shanidze, R.; Sieger, C.; Spies, A.; Wagner, S. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen (Germany); Anvar, S.; Louis, F. [CEA Saclay, Direction des Sciences de la Matiere - Institut de recherche sur les lois fondamentales de l' Univers - Service d' Electronique des Detecteurs et d' Informatique, Gif-sur-Yvette Cedex (France); Astraatmadja, T.; Bogazzi, C.; Bouwhuis, M.C.; Heijboer, A.J.; Jong, M. de; Michael, T.; Palioselitis, D.; Schulte, S.; Steijger, J.J.M.; Visser, E. [Nikhef, Amsterdam (Netherlands); Baret, B.; Bouhou, B.; Creusot, A.; Galata, S.; Kouchner, A.; Elewyck, V. van [Universite Paris Diderot, APC, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Paris (France); Barrios-Marti, J.; Bigongiari, C.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Lambard, G.; Mangano, S.; Sanchez-Losa, A.; Yepes, H.; Zornoza, J.D.; Zuniga, J. [CSIC - Universitat de Valencia, IFIC - Instituto de Fisica Corpuscular, Edificios Investigacion de Paterna, Valencia (Spain); Basa, S.; Marcelin, M.; Nezri, E. [Pole de l' Etoile Site de Chateau-Gombert, LAM - Laboratoire d' Astrophysique de Marseille, Marseille Cedex 13 (France); Biagi, S.; Fusco, L.A.; Giacomelli, G.; Margiotta, A.; Spurio, M. [INFN - Sezione di Bologna, Bologna (Italy); Dipartimento di Fisica dell' Universita, Bologna (Italy); Bruijn, R.; Decowski, M.P.; Wolf, E. de [Nikhef, Amsterdam (Netherlands); Universiteit van Amsterdam, Instituut voor Hoge-Energie Fysica, XG Amsterdam (Netherlands); Capone, A.; De Bonis, G.; Fermani, P.; Perrina, C.; Simeone, F. [INFN - Sezione di Roma, Roma (Italy); Dipartimento di Fisica dell' Universita La Sapienza, Roma (Italy); Caramete, L.; Pavalas, G.E.; Popa, V. [Institute for Space Sciences, Bucharest (Romania); Carloganu, C.; Dumas, A.; Gay, P.; Guillard, G. [Clermont Universite, Universite Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique Corpusculaire, BP 10448, Clermont-Ferrand (France); Cecchini, S.; Chiarusi, T. [INFN - Sezione di Bologna, Bologna (Italy); Charvis, P.; Deschamps, A.; Hello, Y. [Universite Nice Sophia-Antipolis, Geoazur, CNRS/INSU, IRD, Observatoire de la Cote d' Azur, Sophia Antipolis (France); Circella, M. [INFN - Sezione di Bari, Bari (Italy); Dekeyser, I.; Lefevre, D.; Martini, S.; Robert, A.; Tamburini, C. [Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Marseille Cedex 9 (France); Universite du Sud Toulon-Var, CNRS-INSU/IRD UM 110, La Garde Cedex (France); Distefano, C.; Lattuada, D.; Piattelli, P.; Sapienza, P.; Trovato, A. [INFN - Laboratori Nazionali del Sud (LNS), Catania (Italy); Donzaud, C. [Universite Paris Diderot, APC, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Paris (France); Univ Paris-Sud, Orsay Cedex (France); Dorosti, Q.; Loehner, H. [University of Groningen, Kernfysisch Versneller Instituut (KVI), Groningen (Netherlands); Flaminio, V. [INFN - Sezione di Pisa, Pisa (Italy); Dipartimento di Fisica dell' Universita, Pisa (Italy); Giordano, V. [INFN - Sezione di Catania, Catania (Italy); Haren, H. van [Royal Netherlands Institute for Sea Research (NIOZ), ' t Horntje (Texel) (Netherlands); Kadler, M. [Universitaet Wuerzburg, Institut fuer Theoretische Physik und Astrophysik, Wuerzburg (Germany); Kooijman, P. [Nikhef, Amsterdam (Netherlands); Universiteit Utrecht, Faculteit Betawetenschappen, Utrecht (Netherlands); Universiteit van Amsterdam, Instituut voor Hoge-Energie Fysica, XG Amsterdam (Netherlands); Kreykenbohm, I.; Mueller, C.; Wilms, J. [Universitaet Erlangen-Nuernberg, Dr. Remeis-Sternwarte and ECAP, Bamberg (Germany); Kulikovskiy, V. [INFN - Sezione di Genova, Genova (Italy); Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Leonora, E.; Lo Presti, D. [INFN - Sezione di Catania, Catania (Italy); Dipartimento di Fisica ed Astronomia dell' Universita, Catania (IT); Loucatos, S.; Schuessler, F.; Stolarczyk, T.; Vallage, B.; Vernin, P. [CEA Saclay, Direction des Sciences de la Matiere, Institut de recherche sur les lois fondamentales de l' Univers, Service de Physique des Particules, Gif-sur-Yvette Cedex (FR); Montaruli, T. [INFN - Sezione di Bari, Bari (IT); Universite de Geneve, Departement de Physique Nucleaire et Corpusculaire, Geneva (CH); Morganti, M. [INFN - Sezione di Pisa, Pisa (IT); Pradier, T. [Universite de Strasbourg et CNRS/IN2P3, IPHC-Institut Pluridisciplinaire Hubert Curien, 23 rue du Loess, BP 28, Strasbourg Cedex 2 (FR); Rostovtsev, A. [ITEP - Institute for Theoretical and Experimental Physics, Moscow (RU); Samtleben, D.F.E. [Nikhef, Amsterdam (NL); Universiteit Leiden, Leids Instituut voor Onderzoek in Natuurkunde, Leiden (NL); Taiuti, M. [INFN - Sezione di Genova, Genova (IT); Dipartimento di Fisica dell' Universita, Genova (IT); Tayalati, Y. [University Mohammed I, Laboratory of Physics of Matter and Radiations, B.P. 717, Oujda (MA)

2013-10-15

Atmospheric neutrinos are produced during cascades initiated by the interaction of primary cosmic rays with air nuclei. In this paper, a measurement of the atmospheric {nu}{sub {mu}} + anti {nu}{sub {mu}} energy spectrum in the energy range 0.1-200 TeV is presented, using data collected by the ANTARES underwater neutrino telescope from 2008 to 2011. Overall, the measured flux is {proportional_to}25 % higher than predicted by the conventional neutrino flux, and compatible with the measurements reported in ice. The flux is compatible with a single power-law dependence with spectral index {gamma}{sub meas}=3.58{+-}0.12. With the present statistics the contribution of prompt neutrinos cannot be established. (orig.)

An absolute measurement of 252Cf prompt fission neutron spectrum at low energy range

International Nuclear Information System (INIS)

Lajtai, A.; Dyachenko, P.P.; Kutzaeva, L.S.; Kononov, V.N.; Androsenko, P.A.; Androsenko, A.A.

1983-01-01

Prompt neutron energy spectrum at low energies (25 keV 252 Cf spontaneous fission has been measured with a time-of-flight technique on a 30 cm flight-path. Ionization chamber and lithium-glass were used as fission fragment and neutron detectors, respectively. Lithium glasses of NE-912 (containing 6 Li) and of NE-913 (containing 7 Li) 45 mm in diameter and 9.5 mm in thickness have been employed alternatively, for the registration of fission neutrons and gammas. For the correct determination of the multiscattering effects - the main difficulty of the low energy neutron spectrum measurements - a special geometry for the neutron detector was used. Special attention was paid also to the determination of the absolute efficiency of the neutron detector. The real response function of the spectrometer was determined by a Monte-Carlo calculation. The scattering material content of the ionization chamber containing a 252 Cf source was minimized. As a result of this measurement a prompt fission neutron spectrum of Maxwell type with a T=1.42 MeV parameter was obtained at this low energy range. We did not find any neutron excess or irregularities over the Maxwellian. (author)

The Transition from Primary to Secondary School in Mainstream Education for Children with Autism Spectrum Disorder

Science.gov (United States)

Mandy, William; Murin, Marianna; Baykaner, Ozlem; Staunton, Sara; Hellriegel, Josselyn; Anderson, Seonaid; Skuse, David

2016-01-01

The transition from primary to secondary education (hereafter "school transition") is a major ecological shift that poses considerable social, emotional, academic and organisational challenges. It is commonly assumed that this school transition is especially difficult for children with autism spectrum disorder, but that idea is mainly…

The puzzle of the ankle in the Ultrahigh Energy Cosmic Ray Spectrum, and composition indicators

Science.gov (United States)

Farrar, Glennys

2015-08-01

The sharp change in slope of the ultra-high energy cosmic ray spectrum around 10^18.6 eV (the ankle), combined with evidence of a light but extragalactic component near and below the ankle and intermediate composition above, has proved exceedingly challenging to understand theoretically. In this talk I discuss two possible solutions to the puzzle and how they can be (in)validated.First, I present a new mechanism whereby photo-disintegration of ultra-high energy nuclei in the region surrounding a UHECR accelerator naturally accounts for the observed spectrum and inferred composition (using LHC-tuned models extrapolated to UHE) at Earth. We discuss the conditions required to reproduce the spectrum above 10^17.5 eV and the composition, which -- in our model -- consists below the ankle of extragalactic protons and the high energy tail of Galactic Cosmic Rays, and above the ankle of surviving nuclei from the extended source. Predictions for the spectrum and flavors of neutrinos resulting from this process will be presented, and also implications for candidate sources.The other possible explanation is that in actuality UHECRs are entirely or almost entirely protons, and the cross-section for p-Air scattering increases more rapidly above center-of-mass energy of 70 TeV (10 times the current LHC cm energy) than predicted in conventional models. This gives an equally good fit to the depth-of-shower maximum behavior obverved by Auger, while being an intriguing sign of new state in QCD at extremely high energy density.

Thermostatistic properties of a q-deformed ideal Fermi gas with a general energy spectrum

International Nuclear Information System (INIS)

Cai, Shukuan; Su, Guozhen; Chen, Jincan

2007-01-01

The thermostatistic problems of a q-deformed ideal Fermi gas in any dimensional space and with a general energy spectrum are studied, based on the q-deformed Fermi-Dirac distribution. The effects of the deformation parameter q on the properties of the system are revealed. It is shown that q-deformation results in some novel characteristics different from those of an ordinary system. Besides, it is found that the effects of the q-deformation on the properties of the Fermi systems are very different for different dimensional spaces and different energy spectrums

Extended defect related energy loss in CVD diamond revealed by spectrum imaging in a dedicated STEM

International Nuclear Information System (INIS)

Bangert, U.; Harvey, A.J.; Schreck, M.; Hoermann, F.

2005-01-01

This article aims at investigations of the low EEL region in the wide band gap system diamond. The advent of the UHV Enfina electron energy loss spectrometer combined with Digital Micrograph acquisition and processing software has made reliable detection of absorption losses below 10 eV possible. Incorporated into a dedicated STEM this instrumentation allows the acquisition of spectral information via spectrum maps (spectrum imaging) of sample areas hundreds of nanometers across, with nanometers pixel sizes, adequate spectrum statistics and 0.3 eV energy resolution, in direct correlation with microstructural features in the mapping area. We aim at discerning defect related losses at band gap energies, and discuss different routes to simultaneously process and analyse the spectra in a map. This involves extracting the zero loss peak from each spectrum and constructing ratio maps from the intensities in two energy windows, one defect related and one at a higher, crystal bandstructure dominated energy. This was applied to the residual spectrum maps and their first derivatives. Secondly, guided by theoretical EEL spectra calculations, the low loss spectra were fitted by a series of gaussian distributions. Pixel maps were constructed from amplitude ratios of gaussians, situated in the defect and the unaffected energy regime. The results demonstrate the existence of sp 2 -bonded carbon in the vicinity of stacking faults and partial dislocations in CVD diamond as well as additional states below conduction band, tailing deep into the band gap, at a node in a perfect dislocation. Calculated EEL spectra of shuffle dislocations give similar absorption features at 5-8 eV, and it is thought that this common feature is due to sp 2 -type bonding

The high energy x-ray spectrum of the Crab Nebula observed from OSO 8

International Nuclear Information System (INIS)

Dolan, J.F.; Crannell, L.J.; Dennis, B.R.; Orwig, L.E.; Maurer, G.S.

1977-01-01

The X-ray spectrum of the Crab Nebula was measured with the scintillation spectrometer on board the OSO-8 satellite. The total emission of the X-ray source shows no long term variability. The spectrum itself can be described by a single power law out to energies of at least 500 keV

Origin of the ankle in the ultrahigh energy cosmic ray spectrum, and of the extragalactic protons below it

Science.gov (United States)

Unger, Michael; Farrar, Glennys R.; Anchordoqui, Luis A.

2015-12-01

The sharp change in slope of the ultrahigh energy cosmic ray (UHECR) spectrum around 1 018.6 eV (the ankle), combined with evidence of a light but extragalactic component near and below the ankle and intermediate composition above, has proved exceedingly challenging to understand theoretically, without fine-tuning. We propose a mechanism whereby photo-disintegration of ultrahigh energy nuclei in the region surrounding a UHECR accelerator accounts for the observed spectrum and inferred composition at Earth. For suitable source conditions, the model reproduces the spectrum and the composition over the entire extragalactic cosmic ray energy range, i.e. above 1 017.5 eV . Predictions for the spectrum and flavors of neutrinos resulting from this process are also presented.

Direct measurement of the energy spectrum of an intense proton beam

International Nuclear Information System (INIS)

Leeper, R.J.; Lee, J.R.; Kissel, L.; Johnson, D.J.; Stygar, W.A.; Hebron, D.E.; Roose, L.D.

1983-01-01

A time-resolved magnetic spectrometer has been used to measure the energy spectrum of an intense (0.5 TW/cm 2 ) proton beam. A thin (2400 A) gold foil placed at the focus of an ion diode Rutherford scattered protons by 90 0 into the spectrometer, reducing the beam intensity to a level suitable for magnetic analysis. The scattered beam was collimated by two 1 mm diameter apertures separated by 12.3 cm. The collimated protons were deflected in a 12.7 cm diameter, 6.65 Kg samarium-cobalt permanent magnet. The deflected protons were recorded simultaneously on CR-39 and eight 1 mm 2 by 35 μm thick PIN diodes. A Monte Carlo computer code was used to calculate the sensitivity and resolution of the spectrometer. Data taken on Proto-I show a 150 keV to 250 keV wide proton energy spectrum at each instant in time

The vacuum profile of the energy spectrum compressor

International Nuclear Information System (INIS)

Kuijsten, W.J.

1988-12-01

A finite element model has been made of the vacuum system of the Energy Spectrum Compressor. It gives the possibility to calculate the average pressure profile of the system in a fast way. It is required that the average pressure in the system does not influence the present performance of the linac nor the performance of the beam switch yard. Calculations show that with standard pumps of 60 l/s an average pressure of -5 Pa can be obtained. 7 refs.; 8 figs.; 2 tabs

Trigeneration primary energy saving evaluation for energy planning and policy development

International Nuclear Information System (INIS)

Chicco, Gianfranco; Mancarella, Pierluigi

2007-01-01

Trigeneration or combined heat, cooling and power (CHCP) is becoming an increasingly important energy option, particularly on a small-scale basis (below 1 MW e ), with several alternatives nowadays available for the cooling power production and the coupling to cogeneration systems. This paper deals with the introduction of a suitable framework for assessing the energy saving performance of trigeneration alternatives, orientated towards energy planning studies and the development of regulatory policies. In particular, a new generalized performance indicator-the trigeneration primary energy saving (TPES)-is introduced and discussed, with the aim of effectively evaluating the primary energy savings from different CHCP alternatives. The potential of the TPES indicator is illustrated through specific analyses run over different combinations of trigeneration equipment, providing numerical examples based on time-domain simulations to illustrate the dependence of the energy saving characteristics on the CHCP system configurations and equipment, as well as on the loading levels. In addition, the key aspect of adequately establishing the reference efficiencies for the conventional separate production of electrical, thermal and cooling power is addressed in detail. This aspect affects both equipment selection and potential profitability of the considered solutions under the outlook of receiving financial incentives

Impact of dissipation on the energy spectrum of experimental turbulence of gravity surface waves

Science.gov (United States)

Campagne, Antoine; Hassaini, Roumaissa; Redor, Ivan; Sommeria, Joël; Valran, Thomas; Viboud, Samuel; Mordant, Nicolas

2018-04-01

We discuss the impact of dissipation on the development of the energy spectrum in wave turbulence of gravity surface waves with emphasis on the effect of surface contamination. We performed experiments in the Coriolis facility, which is a 13-m-diam wave tank. We took care of cleaning surface contamination as well as possible, considering that the surface of water exceeds 100 m2. We observe that for the cleanest condition the frequency energy spectrum shows a power-law decay extending up to the gravity capillary crossover (14 Hz) with a spectral exponent that is increasing with the forcing strength and decaying with surface contamination. Although slightly higher than reported previously in the literature, the exponent for the cleanest water remains significantly below the prediction from the weak turbulence theory. By discussing length and time scales, we show that weak turbulence cannot be expected at frequencies above 3 Hz. We observe with a stereoscopic reconstruction technique that the increase with the forcing strength of energy spectrum beyond 3 Hz is mostly due to the formation and strengthening of bound waves.

Intermediate neutron spectrum problems and the intermediate neutron spectrum experiment

International Nuclear Information System (INIS)

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

The Self-Efficacy of Primary Teachers in Supporting the Inclusion of Children with Autism Spectrum Disorder

Science.gov (United States)

Anglim, Johanna; Prendeville, Paula; Kinsella, William

2018-01-01

In the context of a trend towards inclusive practice in Irish primary schools, many teachers feel ill-equipped to cope with this new challenge. Scope exists within the Irish education system to transform mainstream schools into autistic spectrum disorder (ASD) friendly environments. Research into teacher perceptions of inclusion has found that…

Measurement of the very-forward energy spectrum in pp collisions at √(s) = 13 TeV with CMS

Energy Technology Data Exchange (ETDEWEB)

Baur, Sebastian; Akbiyik, Melike; Baus, Colin; Katkov, Igor; Ulrich, Ralf; Woehrmann, Hauke [Karlsruher Institut fuer Technologie (Germany)

2016-07-01

The energy spectrum dN/dE in pp collisions at a centre-of-mass energy of √(s)=13 TeV is measured with the CASTOR calorimeter of CMS at pseudorapidities -5.2>η>-6.6. The spectrum of the total energy, as well as the hadronic and electromagnetic energy, is presented and compared to models used to describe high-energy hadronic interactions. The performance also of model used to describe ultra-high energy cosmic ray air showers is tested, and the possible impact of the measurement on the air shower development is illustrated.

Evaluation of a new neutron energy spectrum unfolding code based on an Adaptive Neuro-Fuzzy Inference System (ANFIS).

Science.gov (United States)

Hosseini, Seyed Abolfazl; Esmaili Paeen Afrakoti, Iman

2018-01-17

The purpose of the present study was to reconstruct the energy spectrum of a poly-energetic neutron source using an algorithm developed based on an Adaptive Neuro-Fuzzy Inference System (ANFIS). ANFIS is a kind of artificial neural network based on the Takagi-Sugeno fuzzy inference system. The ANFIS algorithm uses the advantages of both fuzzy inference systems and artificial neural networks to improve the effectiveness of algorithms in various applications such as modeling, control and classification. The neutron pulse height distributions used as input data in the training procedure for the ANFIS algorithm were obtained from the simulations performed by MCNPX-ESUT computational code (MCNPX-Energy engineering of Sharif University of Technology). Taking into account the normalization condition of each energy spectrum, 4300 neutron energy spectra were generated randomly. (The value in each bin was generated randomly, and finally a normalization of each generated energy spectrum was performed). The randomly generated neutron energy spectra were considered as output data of the developed ANFIS computational code in the training step. To calculate the neutron energy spectrum using conventional methods, an inverse problem with an approximately singular response matrix (with the determinant of the matrix close to zero) should be solved. The solution of the inverse problem using the conventional methods unfold neutron energy spectrum with low accuracy. Application of the iterative algorithms in the solution of such a problem, or utilizing the intelligent algorithms (in which there is no need to solve the problem), is usually preferred for unfolding of the energy spectrum. Therefore, the main reason for development of intelligent algorithms like ANFIS for unfolding of neutron energy spectra is to avoid solving the inverse problem. In the present study, the unfolded neutron energy spectra of 252Cf and 241Am-9Be neutron sources using the developed computational code were

On the high energy gamma ray spectrum and the particle production model

International Nuclear Information System (INIS)

Ohta, Itaru; Tezuka, Ikuo.

1979-01-01

A small emulsion chamber, 25 cm x 20 cm in area and 12 radiation lengths in thick, was exposed with JAL jet-cargo at an atmospheric depth of 260 g/cm 2 during 150 hrs. The gamma ray spectrum derived by combining data from X-ray films and nuclear emulsions is well represented by I sub(r) (>=Er) = (3.65 +- 0.30) x 10 -8 [E sub(r)/TeV]sup(-1.89+0.06-0.09)/cm 2 sr sec in the energy range 200 - 3,000 GeV. This result is in good agreement with those of several other groups. We discuss our data in terms of Feynman's and Koba-Nielsen-Olesen's scaling law of high energy particle production model. Interpreted in terms of an assumption of mild violation of the scaling law as x.d delta-s / delta-s indx = AE sup(2a)exp (-BE sup(a)x), our gamma ray spectrum results suggest an existence of a violation parameter of a = 0.18, which is consistent with results from gamma ray spectrum observations at great depth such as the mountain elevations. (author)

THE γ-RAY SPECTRUM OF GEMINGA AND THE INVERSE COMPTON MODEL OF PULSAR HIGH-ENERGY EMISSION

International Nuclear Information System (INIS)

Lyutikov, Maxim

2012-01-01

We reanalyze the Fermi spectra of the Geminga and Vela pulsars. We find that the spectrum of Geminga above the break is well approximated by a simple power law without the exponential cutoff, making Geminga's spectrum similar to that of Crab. Vela's broadband γ-ray spectrum is equally well fit with both the exponential cutoff and the double power-law shapes. In the broadband double power-law fits, for a typical Fermi spectrum of a bright γ-ray pulsar, most of the errors accumulate due to the arbitrary parameterization of the spectral roll-off. In addition, a power law with an exponential cutoff gives an acceptable fit for the underlying double power-law spectrum for a very broad range of parameters, making such fitting procedures insensitive to the underlying Fermi photon spectrum. Our results have important implications for the mechanism of pulsar high-energy emission. A number of observed properties of γ-ray pulsars—i.e., the broken power-law spectra without exponential cutoffs and stretching in the case of Crab beyond the maximal curvature limit, spectral breaks close to or exceeding the maximal breaks due to curvature emission, patterns of the relative intensities of the leading and trailing pulses in the Crab repeated in the X-ray and γ-ray regions, presence of profile peaks at lower energies aligned with γ-ray peaks—all point to the inverse Compton origin of the high-energy emission from majority of pulsars.

Advantages of Real-Time Spectrum Analyzers in High-Energy Physics Applications

International Nuclear Information System (INIS)

Parker, Louis

2004-01-01

Typically, particles are injected into the ring at low energy levels and then 'ramped up' to higher levels. During ramping, it is important that the horizontal and vertical tune frequencies do not shift, lest they hit upon a resonant combination that causes beam instability or sudden total loss of ring beam current (beam blow up). Beam instabilities can be caused by a number of factors. Non-linearities and/or different response times of independent controls such as beam position monitor (BPM) cables and circuits, magnets for guidance and focusing of the beam, Klystrons or Tetrodes (which provide power to RF cavities that transmit energy to the beam), and vacuum pumps and monitors can all cause beam instabilities. Vibrations and lack of proper shielding are other factors. The challenge for operators and researchers is to correctly identify the factors causing beam instabilities and blow up so that costly accelerator time is not interrupted and experimental results are not compromised. The instrument often used to identify problems in particle accelerator applications is the spectrum analyzer. This paper will discuss the advantages of real time spectrum analyzers (RSA) versus swept frequency spectrum analyzers in HEP applications. The main focus will be on monitoring beam position and stability, especially during ramp-up. Also covered will be use of RSA for chromaticity measurements, Phase Locked Loop (PLL) diagnostics, and vibration analysis

Quantum game application to spectrum scarcity problems

Science.gov (United States)

Zabaleta, O. G.; Barrangú, J. P.; Arizmendi, C. M.

2017-01-01

Recent spectrum-sharing research has produced a strategy to address spectrum scarcity problems. This novel idea, named cognitive radio, considers that secondary users can opportunistically exploit spectrum holes left temporarily unused by primary users. This presents a competitive scenario among cognitive users, making it suitable for game theory treatment. In this work, we show that the spectrum-sharing benefits of cognitive radio can be increased by designing a medium access control based on quantum game theory. In this context, we propose a model to manage spectrum fairly and effectively, based on a multiple-users multiple-choice quantum minority game. By taking advantage of quantum entanglement and quantum interference, it is possible to reduce the probability of collision problems commonly associated with classic algorithms. Collision avoidance is an essential property for classic and quantum communications systems. In our model, two different scenarios are considered, to meet the requirements of different user strategies. The first considers sensor networks where the rational use of energy is a cornerstone; the second focuses on installations where the quality of service of the entire network is a priority.

Third-Order Density Perturbation and One-Loop Power Spectrum in Dark-Energy-Dominated Universe(Astrophysics and Cosmology)

OpenAIRE

Ryuichi, TAKAHASHI; Department of Physics and Astrophysics, Nagoya University

2008-01-01

We investigate the third-order density perturbation and the one-loop correction to the linear power spectrum in the dark-energy cosmological model. Our main interest is to understand the dark-energy effect on baryon acoustic oscillations in a quasi-nonlinear regime (k≈0.1h/Mpc). Analytical solutions and simple fitting formulae are presented for the dark-energy model with the general time-varying equation of state w(a). It turns out that the power spectrum coincides with the approximate res...

Neutron fluence rate and energy spectrum in SPRR-300 reactor thermal column

International Nuclear Information System (INIS)

Dou Haifeng; Dai Junlong

2006-01-01

In order to modify the simple one-dimension model, the neutron fluence rate distribution calculated with ANISN code ws checked with that calculated with MCNP code. To modify the error caused by ignoring the neutron landscape orientation leaking, the reflector that can't be modeled in a simple one-dimension model was dealt by extending landscape orientation scale. On this condition the neutron fluence rate distribution and the energy spectrum in the thermal column of SPRR-300 reactor were calculated with one-dimensional code ANISN, and the results of Cd ratio are well accorded with the experimental results. The deviation between them is less than 5% and it isn't above 10% in one or two special positions. It indicates that neutron fluence rate distribution and energy spectrum in the thermal column can be well calculated with one-dimensional code ANISN. (authors)

Ion energy spectrum just after the application of current pulse for turbulent heating in the TRIAM-1 tokamak

Energy Technology Data Exchange (ETDEWEB)

Nakamura, K; Nakamura, Y; Hiraki, N; Itoh, S [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

1981-07-01

Temporal evolution and spatial profile of ion energy spectrum just after the application of current pulse for turbulent heating are investigated experimentally in TRIAM-1 and numerically with a Fokker-Planck equation. Two-component ion energy spectrum formed by turbulent heating relaxes to single one within tau sub(i) (ion collision time).

Ion energy spectrum just after the application of current pulse for turbulent heating in the TRIAM-1 tokamak

International Nuclear Information System (INIS)

Nakamura, Kazuo; Nakamura, Yukio; Hiraki, Naoji; Itoh, Satoshi

1981-01-01

Temporal evolution and spatial profile of ion energy spectrum just after the application of current pulse for turbulent heating are investigated experimentally in TRIAM-1 and numerically with a Fokker-Planck equation. Two-component ion energy spectrum formed by turbulent heating relaxes to single one within tau sub(i) (ion collision time). (author)

Multi-spectrum and transmit-antenna switched diversity schemes for spectrum sharing systems: A performance analysis

KAUST Repository

Sayed, Mostafa

2012-12-01

In spectrum sharing systems, a secondary user (SU) is allowed to share the spectrum with a primary licensed user under the condition that the interference at the the primary user receiver (PU-Rx) is below a predetermined threshold. Joint primary spectrum and transmit antenna selection diversity schemes can be utilized as an efficient way to meet the quality of service (QoS) demands of the SUs while satisfying the interference constraint. In this paper, we consider a secondary link comprised of a secondary transmitter (SU-Tx) equipped with multiple antennas and a single-antenna secondary receiver (SU-Rx) sharing the same spectrum with a number of primary users (PUs) operating at distinct spectra. We present a performance analysis for two primary spectrum and transmit antenna switched selection schemes with different amount of feedback requirements. In particular, assuming Rayleigh fading and BPSK transmission, we derive approximate BER expressions for the presented schemes. For the sake of comparison, we also derive a closed-form BER expression for the optimal selection scheme that selects the best pair in terms of the SU-Rx signal-to-noise ratio (SNR) which has the disadvantage of high feedback requirements. Finally, our results are verified with numerical simulations. © 2012 IEEE.

Simultaneous wireless information and power transfer for spectrum sharing in cognitive radio communication systems

KAUST Repository

Benkhelifa, Fatma

2016-07-26

In this paper, we consider the simultaneous wireless information and power transfer for the spectrum sharing (SS) in cognitive radio (CR) systems with a multi-antenna energy harvesting (EH) primary receiver (PR). The PR uses the antenna switching (AS) technique that assigns a subset of the PR\\'s antennas to harvest the energy from the radio frequency (RF) signals sent by the secondary transmitter (ST), and assigns the rest of the PR\\'s antennas to decode the information data. In this context, the primary network allows the secondary network to use the spectrum as long as the interference induced by the secondary transmitter (ST)\\'s signals is beneficial for the energy harvesting process at the PR side. The objective of this work is to show that the spectrum sharing is beneficial for both the SR and PR sides and leads to a win-win situation. To illustrate the incentive of the spectrum sharing cognitive system, we evaluate the mutual outage probability (MOP) introduced in [1] which declares an outage event if the PR or the secondary receiver (SR) is in an outage. Through the simulation results, we show that the performance of our system in terms of the MOP is always better than the performance of the system in the absence of ST and improves as the ST-PR interference increases. © 2016 IEEE.

Conformal structure in the spectrum of an altered quantum Ising chain

International Nuclear Information System (INIS)

Henkel, M.; Patkos, A.

1986-07-01

The Ising model with an infinite line of defects is mapped onto a strip with two defect lines. The Hamiltonian spectrum is studied at the bulk critical point. Its exact diagonal form is found for an infinite number of sites. The spectrum of physical excitations contains an infinite number of primary fields, while the leading ground state energy correction is independent of the defect strength. A novel algebraic structure interpolating between those belonging to periodic and free boundary conditions is signalled. (orig.)

Primary proton and helium spectra at energy range from 50 TeV to 1015 eV observed with the new Tibet AS core detector array

Directory of Open Access Journals (Sweden)

Huang Jing

2013-06-01

Full Text Available A new EAS hybrid experiment has been designed by constructing a YAC (Yangbajing Air shower Core detector array inside the existing Tibet-III air shower array. The first step of YAC, called “YAC-I” has been successfully carried out in 2009–2010 together with Tibet-III air-shower array. YAC-II has also been operated from 2011. Preliminary results of YAC-I and performance of YAC-II are presented in this paper. The primary proton and helium spectra at energy range from50 TeV to 1015 eV derived from YAC-I data based on QGSJET2 and SIBYLL2.1 are reported. The obtained P+He spectrum is smoothly connected with directobservation data below 100 TeV and also with our previously reported results at higher energies within statistical error s. Based on these results and the sharp kneeof all-particle energy spectrum observed by our experiment, the possible origin of the sharp knee is discussed. See the published papers.

Energy-density spectrum of the vacuum around a cosmic string

International Nuclear Information System (INIS)

Sarmiento, A.; Hacyan, S.

1988-01-01

The explicit form of the spectrum of the energy density of the vacuum surrounding a cosmic string as would be seen by an observer at rest is calculated. Spin-0, -half, or -1 massless fields are considered and it is found that the result is independent of the spin value. An interpretation which differs from the one usually found in the literature is also given

Single-wave-number representation of nonlinear energy spectrum in elastic-wave turbulence of the Föppl-von Kármán equation: energy decomposition analysis and energy budget.

Science.gov (United States)

Yokoyama, Naoto; Takaoka, Masanori

2014-12-01

A single-wave-number representation of a nonlinear energy spectrum, i.e., a stretching-energy spectrum, is found in elastic-wave turbulence governed by the Föppl-von Kármán (FvK) equation. The representation enables energy decomposition analysis in the wave-number space and analytical expressions of detailed energy budgets in the nonlinear interactions. We numerically solved the FvK equation and observed the following facts. Kinetic energy and bending energy are comparable with each other at large wave numbers as the weak turbulence theory suggests. On the other hand, stretching energy is larger than the bending energy at small wave numbers, i.e., the nonlinearity is relatively strong. The strong correlation between a mode a(k) and its companion mode a(-k) is observed at the small wave numbers. The energy is input into the wave field through stretching-energy transfer at the small wave numbers, and dissipated through the quartic part of kinetic-energy transfer at the large wave numbers. Total-energy flux consistent with energy conservation is calculated directly by using the analytical expression of the total-energy transfer, and the forward energy cascade is observed clearly.

Spectrum and energy levels of Y VI

International Nuclear Information System (INIS)

Persson, W.; Reader, J.

1986-01-01

The spectrum of the five-times-ionized yttrium atom (Y VI), excited in a sliding-spark discharge, was studied in the 160--2500 A-circle range. About 900 Y VI lines were classified as transitions between 101 odd and 69 even energy levels.The energy-level system established includes almost all levels of the 4s 2 4p 4 , 4s4p 5 , 4s 2 4p 3 4d, 5d, 5s, 6s, and 5p configurations and a number of levels of the 7s, 4f, and 4s4p 4 4d configurations. The observed level system has been theoretically interpreted by means of Hartree--Fock calculations and least-squares parametric fits. Strong configuration mixings are found between the 4s4p 5 and 4s 2 4p 3 4d configurations, between the 4s 2 4p 3 5p and 4s4p 4 4d configurations, and between the 4s 2 4p 3 4f and 4s4p 4 4d configurations. From the optimized energy-level values, a system of Ritz-type wavelength standards with accuracies varying from 0.0003 to 0.003 A-circle in the range 179--500 A-circle has been determined. The ionization energy as determined from 4s 2 4p 3 ns levels (n = 5-7) is 737 110 +- 200 cm/sup -1/ (91.390 +- 0.025 eV)

Prediction of background in low-energy spectrum of phoswich detector

International Nuclear Information System (INIS)

Arun, B.; Manohari, M.; Mathiyarasu, R.; Rajagopal, V.; Jose, M.T.

2014-01-01

In vivo monitoring of actinides in occupational workers is done using Phoswich detector by measuring the low-energy X ray and gamma rays. Quantification of actinides like plutonium and americium in the lungs is extremely difficult due to higher background in the low-energy regions, which is from ambient background as well as from the subject. In the latter case, it is mainly due to the Compton scattering of body potassium, which varies person-to-person. Hence, an accurate prediction of subject-specific background counts in the lower-energy regions is an essential element in the in vivo measurement of plutonium and americium. Empirical equations are established for the prediction of background count rate in 239 Pu and 241 Am lower-energy regions, called 'target regions', as a function of count rate in the monitoring region (97-130 keV)/ 40 K region in the high-energy spectrum, weight-to-height ratio of the subject (scattering parameter) and the gender. (authors)

Corrections on energy spectrum and scattering for fast neutron radiography at NECTAR facility

International Nuclear Information System (INIS)

Liu Shuquan; Thomas, Boucherl; Li Hang; Zou Yubin; Lu Yuanrong; Guo Zhiyu

2013-01-01

Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM-Ⅱ in Technische Universitaet Mounchen (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections. (authors)

Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

Science.gov (United States)

Liu, Shu-Quan; Bücherl, Thomas; Li, Hang; Zou, Yu-Bin; Lu, Yuan-Rong; Guo, Zhi-Yu

2013-11-01

Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM- II in Technische Universität München (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections.

‘Excess’ of primary cosmic ray electrons

Directory of Open Access Journals (Sweden)

Xiang Li

2015-10-01

Full Text Available With the accurate cosmic ray (CR electron and positron spectra (denoted as Φe− and Φe+, respectively measured by AMS-02 Collaboration, the difference between the electron and positron fluxes (i.e., ΔΦ=Φe−−Φe+, dominated by the propagated primary electrons, can be reliably inferred. In the standard model, the spectrum of propagated primary CR electrons at energies ≥30GeV softens with the increase of energy. The absence of any evidence for such a continuous spectral softening in ΔΦ strongly suggests a significant ‘excess’ of primary CR electrons and at energies of 100–400GeV the identified excess component has a flux comparable to that of the observed positron excess. Middle-age but ‘nearby’ supernova remnants (e.g., Monogem and Geminga are favored sources for such an excess.

Time-resolved energy spectrum of a pseudospark-produced high-brightness electron beam

International Nuclear Information System (INIS)

Myers, T.J.; Ding, B.N.; Rhee, M.J.

1992-01-01

The pseudospark, a fast low-pressure gas discharge between a hollow cathode and a planar anode, is found to be an interesting high-brightness electron beam source. Typically, all electron beam produced in the pseudospark has the peak current of ∼1 kA, pulse duration of ∼50 ns, and effective emittance of ∼100 mm-mrad. The energy information of this electron beam, however, is least understood due to the difficulty of measuring a high-current-density beam that is partially space-charge neutralized by the background ions produced in the gas. In this paper, an experimental study of the time-resolved energy spectrum is presented. The pseudospark produced electron beam is injected into a vacuum through a small pinhole so that the electrons without background ions follow single particle motion; the beam is sent through a negative biased electrode and the only portion of beam whose energy is greater than the bias voltage can pass through the electrode and the current is measured by a Faraday cup. The Faraday cup signals with various bias voltage are recorded in a digital oscilloscope. The recorded waveforms are then numerically analyzed to construct a time-resolved energy spectrum. Preliminary results are presented

Irradiation spectrum and ionization-induced diffusion effects in ceramics

Energy Technology Data Exchange (ETDEWEB)

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.

The measurement of tripartition alpha particle low energy spectrum in 235U fission induced by thermal neutrons

International Nuclear Information System (INIS)

El Hage Sleiman, F.

1980-01-01

The energy spectrum of the α particles emitted in the thermal neutron induced fission of 235 U was measured from 11.5 MeV down to 2 MeV using the parabola mass spectrometer Lohengrin at the ILL high flux reactor. A Monte Carlo program, that simulates the α particle motion to the spectrometer, has been developed. Numerical results of Monte Carlo calculations for differents values of parameter are reported. The overall energy spectrum is slightly asymmetric at low energy. The possible reasons for the existence of this asymmetry are discussed [fr

Integration of Semiconducting Sulfides for Full-Spectrum Solar Energy Absorption and Efficient Charge Separation.

Science.gov (United States)

Zhuang, Tao-Tao; Liu, Yan; Li, Yi; Zhao, Yuan; Wu, Liang; Jiang, Jun; Yu, Shu-Hong

2016-05-23

The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu2-x S, into a single nanocrystal, led to a unique ternary multi-node sheath ZnS-CdS-Cu2-x S heteronanorod for full-spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu2-x S and CdS leads to staggered gaps, as confirmed by first-principles simulations. This band alignment causes effective electron-hole separation in the ternary system and hence enables efficient solar energy conversion. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Composition and energy spectrum variations of auroral ions

International Nuclear Information System (INIS)

Lynch, J.; Leach, R.; Pulliam, D.; Scherb, F.

1977-01-01

We have detected H + ,O + , and He ++ ions with E/q up to 20 keV/charge in a hydrogen aurora over Churchill, Manitoba, during the flight of a Javelin sounding rocket on February 11, 1975, We observed several examples of different types of ion events. One type consisted of bursts of H + and O + ions which arrived simultaneously at all energies within the range of the E/q analyzer. These events were apparently of local origin (distance + ions (O + /H + approximately-greater-than30%). A second type of event consisted of bursts of enhanced H + counting rates but no O + ions. The dispersion in time of the energy spectrum was consistent with an injection and acceleration site located at about 20 R/sub E/ from the earth. An enhancement of the He ++ counting rates was associated with these events, but the He ++ data are of limited statistical significance. A third type of event, consisting of short bursts of H + ions with wide energy spreads, was observed in association with an event in which the energy of the H + ions showed time dispersion. We interpret these short H + bursts as due to ions trapped in traveling waves generated by an explosive injection of plasma in the earth's magnetotail

Dose rate constant and energy spectrum of interstitial brachytherapy sources

International Nuclear Information System (INIS)

Chen Zhe; Nath, Ravinder

2001-01-01

In the past two years, several new manufacturers have begun to market low-energy interstitial brachytherapy seeds containing 125 I and 103 Pd. Parallel to this development, the National Institute of Standards and Technology (NIST) has implemented a modification to the air-kerma strength (S K ) standard for 125 I seeds and has also established an S K standard for 103 Pd seeds. These events have generated a considerable number of investigations on the determination of the dose rate constants (Λ) of interstitial brachytherapy seeds. The aim of this work is to study the general properties underlying the determination of Λ and to develop a simple method for a quick and accurate estimation of Λ. As the dose rate constant of clinical seeds is defined at a fixed reference point, we postulated that Λ may be calculated by treating the seed as an effective point source when the seed's source strength is specified in S K and its source characteristics are specified by the photon energy spectrum measured in air at the reference point. Using a semi-analytic approach, an analytic expression for Λ was derived for point sources with known photon energy spectra. This approach enabled a systematic study of Λ as a function of energy. Using the measured energy spectra, the calculated Λ for 125 I model 6711 and 6702 seeds and for 192 Ir seed agreed with the AAPM recommended values within ±1%. For the 103 Pd model 200 seed, the agreement was 5% with a recently measured value (within the ±7% experimental uncertainty) and was within 1% with the Monte Carlo simulations. The analytic expression for Λ proposed here can be evaluated using a programmable calculator or a simple spreadsheet and it provides an efficient method for checking the measured dose rate constant for any interstitial brachytherapy seed once the energy spectrum of the seed is known

Spectrum and energy levels of the sodiumlike ion Sr/sup 27+/

International Nuclear Information System (INIS)

Reader, J.

1986-01-01

The spectrum of Sr/sup 27+/ was observed with a laser-produced plasma and a 2.2-m grazing-incidence spectrograph in the region 12--160 A-circle. From the identification of 37 lines, a system of 27 energy levels of the type 2p 6 nl was determined. The level system includes the configurations ns(n = 3-5), np(n = 3-6), nd(n = 3-7), nf(n = 4-6), and 5g. The ionization energy is determined as 11 188200 +- 1000 cm/sup -1/ (1387.16 +- 0.12 eV)

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

International Nuclear Information System (INIS)

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)

Hard Decision Fusion based Cooperative Spectrum Sensing in Cognitive Radio System

Directory of Open Access Journals (Sweden)

N. Armi N.M. Saad

2013-09-01

Full Text Available Cooperative spectrum sensing was proposed to combat fading, noise uncertainty, shadowing, and even hidden node problem due to primary users (PUs activity that is not spatially localized. It improves the probability of detection by collaborating to detect PUs signal in cognitive radio (CR system as well. This paper studies cooperative spectrum sensing and signal detection in CR system by implementing hard decision combining in data fusion centre. Through computer simulation, we evaluate the performances of cooperative spectrum sensing and signal detection by employing OR and AND rules as decision combining. Energy detector is used to observe the presence of primary user (PU signal. Those results are compared to non-cooperative signal detection for evaluation. They show that cooperative technique has better performance than non-cooperative. Moreover, signal to noise ratio (SNR with greater than or equal 10 dB and 15 collaborated users in CR system has optimal value for probability of detection.

Spectrum and Charge Ratio of Vertical Cosmic Ray Muons up to Momenta of 2.5 TeV/c

CERN Document Server

Schmelling, M; Grupen, C; Luitz, S; Maciuc, F; Mailov, A; Müller, A -S; Sander, H -G; Schmeling, S; Tcaciuc, R; Wachsmuth, H; Zuber, K

2013-01-01

The ALEPH detector at LEP has been used to measure the momentum spectrum and charge ratio of vertical cosmic ray muons underground. The sea-level cosmic ray muon spectrum for momenta up to 2.5 TeV/c has been obtained by correcting for the overburden of 320 meter water equivalent (mwe). The results are compared with Monte Carlo models for air shower development in the atmosphere. From the analysis of the spectrum the total flux and the spectral index of the cosmic ray primaries is inferred. The charge ratio suggests a dominantly light composition of cosmic ray primaries with energies up to 10^15 eV.

Magnetic diffusion effects on the ultra-high energy cosmic ray spectrum and composition

Energy Technology Data Exchange (ETDEWEB)

Mollerach, Silvia; Roulet, Esteban, E-mail: mollerach@cab.cnea.gov.ar, E-mail: roulet@cab.cnea.gov.ar [CONICET, Centro Atómico Bariloche, Av. Bustillo 9500 (8400) (Argentina)

2013-10-01

We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge Z) in the case in which this suppression happens at energies below ∼ Z EeV, so that energy losses are dominated by the adiabatic ones. The low energy suppression appears when cosmic rays from the closest sources take a time comparable to the age of the Universe to reach the Earth. This occurs for energies E < Z EeV (B/nG)√(l{sub c}/Mpc)(d{sub s}/70Mpc) in terms of the magnetic field RMS strength B, its coherence length l{sub c} and the typical separation between sources d{sub s}. We apply this to scenarios in which the sources produce a mixed composition and have a relatively low maximum rigidity (E{sub max} ∼ (2–10)Z EeV), finding that diffusion has a significant effect on the resulting spectrum, the average mass and on its spread, in particular reducing this last one. For reasonable values of B and l{sub c} these effects can help to reproduce the composition trends observed by the Auger Collaboration for source spectra compatible with Fermi acceleration.

Microstructural evolution of pure tungsten neutron irradiated with a mixed energy spectrum

Energy Technology Data Exchange (ETDEWEB)

Koyanagi, Takaaki, E-mail: koyanagit@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Kumar, N.A.P. Kiran [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Hwang, Taehyun [Tohoku University, Sendai, 980-8579 (Japan); Garrison, Lauren M.; Hu, Xunxiang [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Snead, Lance L. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Katoh, Yutai [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2017-07-15

Microstructures of single-crystal bulk tungsten (W) and polycrystalline W foil with a strong grain texture were investigated using transmission electron microscopy following neutron irradiation at ∼90–800 °C to 0.03–4.6 displacements per atom (dpa) in the High Flux Isotope Reactor with a mixed energy spectrum. The dominant irradiation defects were dislocation loops and small clusters at ∼90 °C. Additional voids were formed in W irradiated at above 460 °C. Voids and precipitates involving transmutation rhenium and osmium were the dominant defects at more than ∼1 dpa. We found a new phenomenon of microstructural evolution in irradiated polycrystalline W: Re- and Os-rich precipitation along grain boundaries. Comparison of results between this study and previous studies using different irradiation facilities revealed that the microstructural evolution of pure W is highly dependent on the neutron energy spectrum in addition to the irradiation temperature and dose.

ADAPTIVE FULL-SPECTRUM SOLAR ENERGY SYSTEMS CROSS-CUTTING R&D ON ADAPTIVE FULL-SPECTRUM SOLAR ENERGY SYSTEMS FOR MORE EFFICIENT AND AFFORDABLE USE OF SOLAR ENERGY IN BUILDINGS AND HYBRID PHOTOBIOREACTORS

Energy Technology Data Exchange (ETDEWEB)

Byard D. Wood; Jeff D. Muhs

2004-08-01

This RD&D project is a three year team effort to develop a hybrid solar lighting (HSL) system that transports daylight from a paraboloidal dish concentrator to a luminaire via a bundle of small core or a large core polymer fiber optics. The luminaire can be a device to distribute sunlight into a space for the production of algae or it can be a device that is a combination of daylighting and electric lighting for space/task lighting. In this project, the sunlight is collected using a one-meter paraboloidal concentrator dish with two-axis tracking. For the second generation (alpha) system, the secondary mirror is an ellipsoidal mirror that directs the visible light into a bundle of small-core fibers. The IR spectrum is filtered out to minimize unnecessary heating at the fiber entrance region. This report describes the following investigations of various aspects of the system. Taken as a whole, they confirm significant progress towards the technical feasibility and commercial viability of this technology. (1) TRNSYS Modeling of a Hybrid Lighting System: Building Energy Loads and Chromaticity Analysis; (2) High Lumens Screening Test Setup for Optical Fibers; (3) Photo-Induced Heating in Plastic Optical Fiber Bundles; (4) Low-Cost Primary Mirror Development; (5) Potential Applications for Hybrid Solar Lighting; (6) Photobioreactor Population Experiments and Productivity Measurements; and (7) Development of a Microalgal CO2-Biofixation Photobioreactor.

Photon beam convolution using polyenergetic energy deposition kernels

International Nuclear Information System (INIS)

Hoban, P.W.; Murray, D.C.; Round, W.H.

1994-01-01

In photon beam convolution calculations where polyenergetic energy deposition kernels (EDKs) are used, the primary photon energy spectrum should be correctly accounted for in Monte Carlo generation of EDKs. This requires the probability of interaction, determined by the linear attenuation coefficient, μ, to be taken into account when primary photon interactions are forced to occur at the EDK origin. The use of primary and scattered EDKs generated with a fixed photon spectrum can give rise to an error in the dose calculation due to neglecting the effects of beam hardening with depth. The proportion of primary photon energy that is transferred to secondary electrons increases with depth of interaction, due to the increase in the ratio μ ab /μ as the beam hardens. Convolution depth-dose curves calculated using polyenergetic EDKs generated for the primary photon spectra which exist at depths of 0, 20 and 40 cm in water, show a fall-off which is too steep when compared with EGS4 Monte Carlo results. A beam hardening correction factor applied to primary and scattered 0 cm EDKs, based on the ratio of kerma to terma at each depth, gives primary, scattered and total dose in good agreement with Monte Carlo results. (Author)

Measurement of Cosmic-Ray Antiproton Spectrum at Solar Minimum with a Long-Duration Balloon Flight in Antarctica

Science.gov (United States)

Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Kim, K. C.; Kusumoto, A.; Lee, M. H.; Makida, Y.;

Energy and spectrum of BeO molecule under the electric field from different directions

NARCIS (Netherlands)

Jiang, M.; Guo, F. J.; Yan, A. Y.; Zhang, C. W.; Miao, F.

2010-01-01

Based on the density functional theory DFT/ B3LYP at 6-311g level, the ground states of BeO molecule are optimized. The effects of electric field on the bond length, the system energy, the charge distribution, the energy levels, the HOMO-LUMO gaps and the infrared spectrum of BeO molecule are

Acquiring a Pet Dog Significantly Reduces Stress of Primary Carers for Children with Autism Spectrum Disorder: A Prospective Case Control Study

Science.gov (United States)

Wright, H. F.; Hall, S.; Hames, A.; Hardiman, J.; Mills, R.; Mills, D. S.

2015-01-01

This study describes the impact of pet dogs on stress of primary carers of children with Autism Spectrum Disorder (ASD). Stress levels of 38 primary carers acquiring a dog and 24 controls not acquiring a dog were sampled at: Pre-intervention (17 weeks before acquiring a dog), post-intervention (3-10 weeks after acquisition) and follow-up…

Joint switched multi-spectrum and transmit antenna diversity for spectrum sharing systems

KAUST Repository

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

2013-01-01

. In this paper, we consider a secondary network comprised of a secondary transmitter (SU-Tx) equipped with multiple antennas and a single-antenna secondary receiver (SU-Rx) sharing the same spectrum with multiple primary users (PUs), each with a distinct spectrum

Energy spectrum of two-dimensional tight-binding electrons in a spatially varying magnetic field

International Nuclear Information System (INIS)

Oh, G.Y.; Lee, M.H.

1996-01-01

The electronic energy spectrum of a two-dimensional lattice in a spatially varying magnetic field is studied within the framework of the tight-binding model by using the scheme of the transfer matrix. It is found that, in comparison with the case of a uniform magnetic field, the energy spectrum exhibits more complicated behavior; band broadening (or gap closing) and band splitting (or gap opening) occur depending on characteristic parameters of the lattice. The origin of these phenomena lies in the existence of direct touching and indirect overlapping between neighboring subbands. Dependence of direct touching and indirect overlapping, and thus the electronic band structure together with the density of states, on characteristic parameters of the lattice is elucidated in detail. copyright 1996 The American Physical Society

Prompt neutron fission spectrum mean energies for the fissile nuclides and 252Cf

International Nuclear Information System (INIS)

Holden, N.E.

1985-01-01

The international standard for a neutron spectrum is that produced from the spontaneous fission of 252 Cf, while the thermal neutron induced fission neutron spectra for the four fissile nuclides, 233 U, 235 U, 239 Pu, and 241 Pu are of interest from the standpoint of nuclear reactors. The average neutron energies of these spectra are tabulated. The individual measurements are recorded with the neutron energy range measured, the method of detection as well as the average neutron energy for each author. Also tabulated are the measurements of the ratio of mean energies for pairs of fission neutron spectra. 75 refs., 9 tabs

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

KAUST Repository

Sayed, Mostafa M.

2014-11-01

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 receiver (PU-Rx). In this paper, we consider a secondary link composed of a secondary transmitter (SU-Tx) equipped with multiple antennas and a single-antenna secondary receiver (SU-Rx). The secondary link is allowed to share the spectrum with a primary network composed of multiple PUs communicating over distinct frequency spectra with a primary base station. We develop a transmission scheme where the SU-Tx initially broadcasts a set of random beams over all the available primary spectra for which the PU-Rx sends back the index of the spectrum with the minimum interference level, as well as information that describes the interference value, for each beam. Based on the feedback information on the PU-Rx, the SU-Tx adapts the transmitted beams and then resends the new beams over the best primary spectrum for each beam to the SU-Rx. The SU-Rx selects the beam that maximizes the received signal-to-interference-plus-noise ratio (SINR) to be used in transmission over the next frame. We consider three cases for the level of feedback information describing the interference level. In the first case, the interference level is described by both its magnitude and phase; in the second case, only the magnitude is considered; and in the third case, we focus on a q-bit description of its magnitude. In the latter case, we propose a technique to find the optimal quantizer thresholds in a mean-square-error sense. We also develop a statistical analysis for the SINR statistics and the capacity and bit error rate of the secondary link and present numerical results that study the impact of the different system parameters.

Extensive air showers accompanied by gamma-families and fraction of protons in the primary cosmic rays

International Nuclear Information System (INIS)

Hamayasu, C.; Saito, To.; Sakata, M.

1987-01-01

Experimental data of EAS accompanied by gamma-families with a total energy greater than 10 TeV are taken at Mt. Norikura in 1980 -- 1981 and in 1985. An EX (emulsion and/or x-ray film) chamber is used, which consists six sensitive layers and iron plates as the absorber. The iron absorber chamber can detect more hadron origin cascades than a lead absorber chamber for the same chamber thickness in radiation length, though disadvantageous for separation of gamma-ray origin cascades from hadron origin ones. Analysis is made of the single gamma-ray energy spectrum, integral spectrum of total energies of gamma-families, zenith angle distributions of gamma-families, the scatter plot of EAS size - ΣE γ,H correlation, arrival zenith angle distribution of general EAS, and depth dependence of absolute vertical intensities of EAS. The data obtained are compared by the Monte Carlo simulation technique with a moderate rising cross section proportional to the collision energy in the form E 0.04 for p-air nucleus collisions. The absolute intensity of size spectrum of such EAS is strongly affected by the fraction of primary protonsin the 10 15 -- 10 16 eV region. The experimental size spectrum agrees with the simulated spectrum for the p-poor (up to 15 %) primary composition but it disagrees with the p-rich (up to 40 %) one in the first half, at least, of this energy region. (Nogami, K.)

Neutron energy spectrum determination near the surface on the JET vacuum vessel using the multifoil activation technique

Energy Technology Data Exchange (ETDEWEB)

Pillon, M.; Jarvis, O.N.; Conroy, S. (Associazione EURATOM-ENEA sulla Fusione, Frascati (Italy) JET Joint Undertaking, Abingdonm Oxon (U.K.) Imperial College of Science, Technology and Medicine, London (U.K.))

1990-03-01

The activation of foils of zinc, indium, aluminium, copper and magnesium has been used as a means of examining the energy spectrum of neutrons produced by discharges in the Joint European Torus (JET). Several threshold reactions have been used together with a least-squares unfolding code to determine the 2.5 and 14 MeV neutron yields produced by the JET plasma. The analysis shows that the energy spectrum produced by downscattered neutrons is satisfactorily calculated with the MCNP neutron transport code.

Design and Analysis of Hybrid Solar Lighting and Full-Spectrum Solar Energy Systems

International Nuclear Information System (INIS)

Muhs, J.D.

2001-01-01

This paper describes a systems-level design and analysis of a new approach for improving the energy efficiency and affordability of solar energy in buildings, namely, hybrid solar lighting and full-spectrum solar energy systems. By using different portions of the solar spectrum simultaneously for multiple end-use applications in buildings, the proposed system offers unique advantages over other alternatives for using sunlight to displace electricity (conventional topside daylighting and solar technologies). Our preliminary work indicates that hybrid solar lighting, a method of collecting and distributing direct sunlight for lighting purposes, will alleviate many of the problems with passive daylighting systems of today, such as spatial and temporal variability, glare, excess illumination, cost, and energy efficiency. Similarly, our work suggests that the most appropriate use of the visible portion of direct, nondiffuse sunlight from an energy-savings perspective is to displace electric light rather than generate electricity. Early estimates detailed in this paper suggest an anticipated system cost of well under$2.0/Wp and 5-11(cents)/kWh for displaced and generated electricity in single-story commercial building applications. Based on a number of factors discussed in the paper, including sunlight availability, building use scenarios, time-of-day electric utility rates, cost, and efficacy of the displaced electric lights, the simple payback of this approach in many applications could eventually be well under 5 years

The importance of the PKA-energy spectrum for radiation damage simulation

International Nuclear Information System (INIS)

Dierckx, R.

1987-01-01

Primary damage phenomena as a function of the PKA-energy are simulated with the MARLOWE code. The PKA's studied have energies up to 2 MeV. The displacement cascades are divided into subcascades, the characteristics of which are determined. (orig.)

Dark Energy Constraints from the Thermal Sunyaev Zeldovich Power Spectrum

Science.gov (United States)

Bolliet, Boris; Comis, Barbara; Komatsu, Eiichiro; Macías-Pérez, Juan Francisco

2018-03-01

We constrain the dark energy equation of state parameter, w, using the power spectrum of the thermal Sunyaev-Zeldovich (tSZ) effect. We improve upon previous analyses by taking into account the trispectrum in the covariance matrix and marginalising over the foreground parameters, the correlated noise, the mass bias B in the Planck universal pressure profile, and all the relevant cosmological parameters (i.e., not just Ωm and σ8). We find that the amplitude of the tSZ power spectrum at ℓ ≲ 103 depends primarily on F ≡ σ8(Ωm/B)0.40h-0.21, where B is related to more commonly used variable b by B = (1 - b)-1. We measure this parameter with 2.6% precision, F = 0.460 ± 0.012 (68% CL). By fixing the bias to B = 1.25 and adding the local determination of the Hubble constant H0 and the amplitude of the primordial power spectrum constrained by the Planck Cosmic Microwave Background (CMB) data, we find w = -1.10 ± 0.12, σ8 = 0.802 ± 0.037, and Ωm = 0.265 ± 0.022 (68% CL). Our limit on w is consistent with and is as tight as that from the distance-alone constraint from the CMB and H0. Finally, by combining the tSZ power spectrum and the CMB data we find, in the Λ Cold Dark Matter (CDM) model, the mass bias of B = 1.71 ± 0.17, i.e., 1 - b = 0.58 ± 0.06 (68% CL).

Development of analytical software for semi-quantitative analysis of x-ray spectrum acquired from energy-dispersive spectrometer

International Nuclear Information System (INIS)

Karim, A.; Rana, M.A.; Qamar, R.; Latif, A; Ahmad, M.; Farooq, M.A.; Ahmad, Z.

2003-12-01

Software package for elemental analysis for X-ray spectrum obtained from Energy Dispersive Spectrometer (EDS) attached with Scanning Electron Microscope (SEM) has been developed: A Personal Computer Analyzer card PCA-800 is used to acquire data from the EDS. This spectrum is obtained in binary format, which is transformed into ASCII format using PCAII card software. The program is modular in construction and coded using Microsoft's QUICKBASIC compiler linker. Energy line library containing all lines of elements is created for analysis of acquired characteristic X-ray spectrum. Two techniques of peak identification are provided. Statistical tools are employed for smoothing of a curve and for computing area under the curve. Elemental concentration is calculated in weight % and in atomic. (author)

A Review on Spectrum Sensing for Cognitive Radio: Challenges and Solutions

Directory of Open Access Journals (Sweden)

Yonghong Zeng

2010-01-01

Full Text Available Cognitive radio is widely expected to be the next Big Bang in wireless communications. Spectrum sensing, that is, detecting the presence of the primary users in a licensed spectrum, is a fundamental problem for cognitive radio. As a result, spectrum sensing has reborn as a very active research area in recent years despite its long history. In this paper, spectrum sensing techniques from the optimal likelihood ratio test to energy detection, matched filtering detection, cyclostationary detection, eigenvalue-based sensing, joint space-time sensing, and robust sensing methods are reviewed. Cooperative spectrum sensing with multiple receivers is also discussed. Special attention is paid to sensing methods that need little prior information on the source signal and the propagation channel. Practical challenges such as noise power uncertainty are discussed and possible solutions are provided. Theoretical analysis on the test statistic distribution and threshold setting is also investigated.

Measuring the low-energy cosmic ray spectrum with the AFIS detector

Energy Technology Data Exchange (ETDEWEB)

Losekamm, Martin [Physics Department E18, Technische Universitaet Muenchen (Germany); Institute of Astronautics, Technische Universitaet Muenchen (Germany); Gaisbauer, Dominic; Greenwald, Daniel; Hahn, Alexander; Hauptmann, Philipp; Konorov, Igor; Meng, Lingxin; Paul, Stephan; Poeschl, Thomas [Physics Department E18, Technische Universitaet Muenchen (Germany); Renker, Dieter [Physics Department E17, Technische Universitaet Muenchen (Germany)

2014-07-01

High-energy cosmic rays interact with Earth's upper atmosphere and produce antiprotons, which can be trapped in Earth's magnetic field. The Antiproton Flux in Space (AFIS) Mission will measure the flux of trapped antiprotons with energies less than 100 MeV aboard the nanosatellite MOVE 2. An active-target tracking detector comprised of scintillating plastic fibers and silicon photomultipliers is already under construction at the Technische Universitaet Muenchen. As a precursor to the space-bound mission, a prototype version of the detector will be launched aboard a balloon from Kiruna, Sweden as part of the REXUS/BEXUS student program by the German Aerospace Center (DLR). Named AFIS-P, it will be used to measure the low-energy part of the cosmic-ray spectrum for energies less than 100 MeV-per-nucleon. Spectrometers in previous balloon missions were not sensitive in this low-energy region. Thus AFIS-P will deliver unprecedented data, while simultaneously allowing us to field-test the AFIS detector.

Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

Energy Technology Data Exchange (ETDEWEB)

Sathre, Roger [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Gustavsson, Leif [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

2010-04-15

In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

International Nuclear Information System (INIS)

Sathre, Roger; Gustavsson, Leif; Bergh, Johan

2010-01-01

In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO 2equiv if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

Energy Technology Data Exchange (ETDEWEB)

Sathre, Roger; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

2010-04-15

In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission. (author)

CHANDRA HIGH-ENERGY TRANSMISSION GRATING SPECTRUM OF AE AQUARII

International Nuclear Information System (INIS)

Mauche, Christopher W.

2009-01-01

The nova-like cataclysmic binary AE Aqr, which is currently understood to be a former supersoft X-ray binary and current magnetic propeller, was observed for over two binary orbits (78 ks) in 2005 August with the High-Energy Transmission Grating (HETG) on board the Chandra X-ray Observatory. The long, uninterrupted Chandra observation provides a wealth of details concerning the X-ray emission of AE Aqr, many of which are new and unique to the HETG. First, the X-ray spectrum is that of an optically thin multi-temperature thermal plasma; the X-ray emission lines are broad, with widths that increase with the line energy from σ ∼ 1 eV (510 km s -1 ) for O VIII to σ ∼ 5.5 eV (820 km s -1 ) for Si XIV; the X-ray spectrum is reasonably well fit by a plasma model with a Gaussian emission measure distribution that peaks at log T(K) = 7.16, has a width σ = 0.48, an Fe abundance equal to 0.44 times solar, and other metal (primarily Ne, Mg, and Si) abundances equal to 0.76 times solar; and for a distance d = 100 pc, the total emission measure EM = 8.0 x 10 53 cm -3 and the 0.5-10 keV luminosity L X = 1.1 x 10 31 erg s -1 . Second, based on the f/(i + r) flux ratios of the forbidden (f), intercombination (i), and recombination (r) lines of the Heα triplets of N VI, O VII, and Ne IX measured by Itoh et al. in the XMM-Newton Reflection Grating Spectrometer spectrum and those of O VII, Ne IX, Mg XI, and Si XIII in the Chandra HETG spectrum, either the electron density of the plasma increases with temperature by over three orders of magnitude, from n e ∼ 6 x 10 10 cm -3 for N VI [log T(K) ∼ 6] to n e ∼ 1 x 10 14 cm -3 for Si XIII [log T(K) ∼ 7], and/or the plasma is significantly affected by photoexcitation. Third, the radial velocity of the X-ray emission lines varies on the white dwarf spin phase, with two oscillations per spin cycle and an amplitude K ∼ 160 km s -1 . These results appear to be inconsistent with the recent models of Itoh et al., Ikhsanov, and

PROBING THE INFLATON: SMALL-SCALE POWER SPECTRUM CONSTRAINTS FROM MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND ENERGY SPECTRUM

International Nuclear Information System (INIS)

Chluba, Jens; Erickcek, Adrienne L.; Ben-Dayan, Ido

2012-01-01

In the early universe, energy stored in small-scale density perturbations is quickly dissipated by Silk damping, a process that inevitably generates μ- and y-type spectral distortions of the cosmic microwave background (CMB). These spectral distortions depend on the shape and amplitude of the primordial power spectrum at wavenumbers k ∼ 4 Mpc –1 . Here, we study constraints on the primordial power spectrum derived from COBE/FIRAS and forecasted for PIXIE. We show that measurements of μ and y impose strong bounds on the integrated small-scale power, and we demonstrate how to compute these constraints using k-space window functions that account for the effects of thermalization and dissipation physics. We show that COBE/FIRAS places a robust upper limit on the amplitude of the small-scale power spectrum. This limit is about three orders of magnitude stronger than the one derived from primordial black holes in the same scale range. Furthermore, this limit could be improved by another three orders of magnitude with PIXIE, potentially opening up a new window to early universe physics. To illustrate the power of these constraints, we consider several generic models for the small-scale power spectrum predicted by different inflation scenarios, including running-mass inflation models and inflation scenarios with episodes of particle production. PIXIE could place very tight constraints on these scenarios, potentially even ruling out running-mass inflation models if no distortion is detected. We also show that inflation models with sub-Planckian field excursion that generate detectable tensor perturbations should simultaneously produce a large CMB spectral distortion, a link that could potentially be established with PIXIE.

Determination of the neutrons energy spectrum in the central thimble of the reactor core TRIGA Mark III

International Nuclear Information System (INIS)

Parra M, M. A.; Luis L, M. A.; Raya A, R.; Cruz G, H. S.

2013-10-01

This work presents the measurement of the neutrons spectrum in energies in the central thimble of the reactor TRIGA Mark III to a power of 1 MW in stationary state, with the core in the center of the pool. To achieve this objective, several thin sheets were irradiated (one at the time) in the same position of the core. The activation probes were selected in such a way that covered the energy range (1 x 10 -10 to 20 MeV) of the neutrons spectrum in the reactor core, for this purpose thin sheets were used of 197 Au, 58 Ni, 115 In, 24 Mg, 27 Al, 58 Fe, 59 Co and 63 Cu. After the irradiation, the high energy gamma emissions of the activated thin sheets were measured by means of gamma spectrometry, in a counting system of high resolution, with a Hyper pure Germanium detector, obtaining this way the activity induced in the thin sheets whose magnitude is proportional to the intensity of the neutrons flow, this activity together to a theoretical initial spectrum are the main entrance data of the computational code SANDBP (Hungarian version of the code Sand-II) that uses the unfolding method for the calculation of the spectrum. (Author)

Joint random beam and spectrum selection for spectrum sharing systems with partial channel state information

KAUST Repository

Abdallah, Mohamed M.

2013-11-01

In this work, we develop joint interference-aware random beam and spectrum selection scheme that provide enhanced performance for the secondary network under the condition that the interference observed at the primary receiver is below a predetermined acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a set of primary links composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes jointly select a beam, among a set of power-optimized random beams, as well as the primary spectrum that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint. In particular, we consider the case where the interference level is described by a q-bit description of its magnitude, whereby we propose a technique to find the optimal quantizer thresholds in a mean square error (MSE) sense. © 2013 IEEE.

Joint random beam and spectrum selection for spectrum sharing systems with partial channel state information

KAUST Repository

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

2013-01-01

In this work, we develop joint interference-aware random beam and spectrum selection scheme that provide enhanced performance for the secondary network under the condition that the interference observed at the primary receiver is below a predetermined acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a set of primary links composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes jointly select a beam, among a set of power-optimized random beams, as well as the primary spectrum that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint. In particular, we consider the case where the interference level is described by a q-bit description of its magnitude, whereby we propose a technique to find the optimal quantizer thresholds in a mean square error (MSE) sense. © 2013 IEEE.

Polarimetry of coherent bremsstrahlung by analysis of the photon energy spectrum

International Nuclear Information System (INIS)

Darbinyan, S.; Hakobyan, H.; Jones, R.; Sirunyan, A.; Vartapetian, H.

2005-01-01

A method of coherent bremsstrahlung (CB) polarimetry based on the analysis of the shape of the photon energy spectrum is presented. The influence of a number of uncertainty sources, including the choice of atomic form-factors, has been analyzed. For a CB source consisting of a diamond radiator and multi-GeV electrons, an absolute accuracy of polarimetry at the level of 0.01-0.02 is attainable

Monte Carlo calculation of the energy deposited in the KASCADE GRANDE detectors

International Nuclear Information System (INIS)

Mihai, Constantin

2004-01-01

The energy deposited by protons, electrons and positrons in the KASCADE GRANDE detectors is calculated with a simple and fast Monte Carlo method. The KASCADE GRANDE experiment (Forschungszentrum Karlsruhe, Germany), based on an array of plastic scintillation detectors, has the aim to study the energy spectrum of the primary cosmic rays around and above the 'knee' region of the spectrum. The reconstruction of the primary spectrum is achieved by comparing the data collected by the detectors with simulations of the development of the extensive air shower initiated by the primary particle combined with detailed simulations of the detector response. The simulation of the air shower development is carried out with the CORSIKA Monte Carlo code. The output file produced by CORSIKA is further processed with a program that estimates the energy deposited in the detectors by the particles of the shower. The standard method to calculate the energy deposit in the detectors is based on the Geant package from the CERN library. A new method that calculates the energy deposit by fitting the Geant based distributions with simpler functions is proposed in this work. In comparison with the method based on the Geant package this method is substantially faster. The time saving is important because the number of particles involved is large. (author)

A preliminary layout and PIC simulations of the time resolved beam energy spectrum measurement for DRAGON-I

International Nuclear Information System (INIS)

Liao Shuqing; Zhang Kaizhi; Shi Jingshui

2010-01-01

The time resolved beam energy spectrum for DRAGON-I can be measured with a new method which is named RBS (Rotating Beam in Solenoid). The beam energy spectrum is determined by measuring the beam rotation angle and its expansion width at the exit of DRAGON-I. The rotation beam is shaped by a slit at the exit of DRAGON-I, then rotated in the magnetic field of the solenoids and the resulted beamlet is measured by the Cherenkov screen. The beam motion in the solenoids is simulated by PARMELA and the relationships between the beam rotation angle's expansion width and the beam energy spread, emittance are discussed. The measurement error is also discussed in this paper. (authors)

On the infimum of the energy-momentum spectrum of a homogeneous Bose gas

DEFF Research Database (Denmark)

Cornean, Horia; Derezinski, J.; Zin, P.

2009-01-01

We consider second-quantized homogeneous Bose gas in a large cubic box with periodic boundary conditions at zero temperature. We discuss the energy-momentum spectrum of the Bose gas and its physical significance. We review various rigorous and heuristic results as well as open conjectures about its...

Comparison of RF spectrum prediction methods for dynamic spectrum access

Science.gov (United States)

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.

The water footprint of energy consumption: an assessment of water requirements of primary energy carriers

NARCIS (Netherlands)

Gerbens-Leenes, P.W.; Hoekstra, A.Y.; Van der Meer, T.H.

2007-01-01

Gerbens-Leenes, P.W., Hoekstra, A.Y., Van der Meer, T.H., 2007. The water footprint of energy consumption: an assessment of water requirements of primary energy carriers. In: proceedings ‘First World Water Sustainability-Renewable Energy Congress and Exhibition’. 25-28 November 2007, Maastricht, the

The Cosmic Ray Energy Spectrum and Related Measurements with the Pierre Auger Observatory

Energy Technology Data Exchange (ETDEWEB)

Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

2009-06-01

These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the cosmic ray energy spectrum above 10{sup 18} eV with the Pierre Auger Observatory; (2) The cosmic ray flux observed at zenith angles larger than 60 degrees with the Pierre Auger Observatory; (3) Energy calibration of data recorded with the surface detectors of the Pierre Auger Observatory; (4) Exposure of the Hybrid Detector of The Pierre Auger Observatory; and (5) Energy scale derived from Fluorescence Telescopes using Cherenkov Light and Shower Universality.

Classification and performance analysis of primary energy consumers during 1980-1999

International Nuclear Information System (INIS)

Ediger, Volkan S.

2003-01-01

Five primary energy consumer classes, namely Super, Major, Big, Medium and Small, are proposed, depending on the polymodal characteristics of the frequency distribution curve of their share of the total. The total primary energy consumption and its annual additions decrease, whereas the rates increase steadily from the Super to the Medium consumers. Since the frequency distribution histogram of additional primary energy consumptions of the Medium and above consumers during 1980-1999 is a typical bell shaped curve, the additional amounts and rates are used together to evaluate the performance levels of the countries in both parameters. The most successful countries are the USA, China, South Korea, Thailand, India, Indonesia, Taiwan, Turkey and Iran. The reason why the Super consumer USA and the Major consumer China are the biggest energy markets is because they are the first two biggest economies in the world. The success of the developing Asian countries is mostly related to their economic ties with the Super consumer USA. Among the other emerging markets, Turkey's primary energy demand has grown more rapidly than that of Iran and is expected to continue growing in the future. The emerging Medium and Big consumer markets will continue to play a significant role in the world's energy sector during the first two decades of the 21st century

Green Cooperative Spectrum Sensing and Scheduling in Heterogeneous Cognitive Radio Networks

KAUST Repository

Celik, Abdulkadir

2016-09-12

In this paper, we consider heterogeneous cognitive radio networks (CRNs) comprising primary channels (PCs) with heterogeneous characteristics and secondary users (SUs) with various sensing and reporting qualities for different PCs. We first define the opportunity as the achievable total data rate and its cost as the energy consumption caused from sensing, reporting, and channel switching operations and formulate a joint spectrum discovery and energy efficiency objective to minimize the energy spent per unit of data rate. Then, a mixed integer nonlinear programming problem is formulated to determine: 1) the optimal subset of PCs to be scheduled for sensing; 2) the SU assignment set for each scheduled PC; and 3) sensing durations and detection thresholds of each SU on PCs it is assigned to sense. Thereafter, an equivalent convex framework is developed for specific instances of the above combinatorial problem. For comparison, optimal detection and sensing thresholds are also derived analytically under the homogeneity assumption. Based on these, a prioritized ordering heuristic is developed to order channels under the spectrum, energy, and spectrum-energy limited regimes. After that, a scheduling and assignment heuristic is proposed and is shown to perform very close to the exhaustive optimal solution. Finally, the behavior of the CRN is numerically analyzed under these regimes with respect to different numbers of SUs, PCs, and sensing qualities.

Primary energy and greenhouse gases embodied in Australian final consumption: an input-output analysis

International Nuclear Information System (INIS)

Lenzen, M.

1998-01-01

Input-output modeling of primary energy and greenhouse gas embodiments in goods and services is a useful technique for designing greenhouse gas abatement policies. The present paper describes direct and indirect primary energy and greenhouse gas requirements for a given set of Australian final consumption. It considers sectoral disparities in energy prices, capital formation and international trade flows and it accounts for embodiments in the Gross National Expenditure as well as the Gross Domestic Product. Primary energy and greenhouse gas intensities in terms of MJ/$ and kg CO 2 -e/$ are reported, as well as national balance of primary energy consumption and greenhouse gas emissions. (author)

Dynamic Modelling with "MLE-Energy Dynamic" for Primary School

Science.gov (United States)

Giliberti, Enrico; Corni, Federico

During the recent years simulation and modelling are growing instances in science education. In primary school, however, the main use of software is the simulation, due to the lack of modelling software tools specially designed to fit/accomplish the needs of primary education. In particular primary school teachers need to use simulation in a framework that is both consistent and simple enough to be understandable by children [2]. One of the possible area to approach modelling is about the construction of the concept of energy, in particular for what concerns the relations among substance, potential, power [3]. Following the previous initial research results with this approach [2], and with the static version of the software MLE Energy [1], we suggest the design and the experimentation of a dynamic modelling software—MLE dynamic-capable to represent dynamically the relations occurring when two substance-like quantities exchange energy, modifying their potential. By means of this software the user can graphically choose the dependent and independent variables and leave the other parameters fixed. The software has been initially evaluated, during a course of science education with a group of primary school teachers-to-be, to test the ability of the software to improve teachers' way of thinking in terms of substance-like quantities and their effects (graphical representation of the extensive, intensive variables and their mutual relations); moreover, the software has been tested with a group of primary school teachers, asking their opinion about the software didactical relevance in the class work.

Indoor measurement of photovoltaic device characteristics at varying irradiance, temperature and spectrum for energy rating

International Nuclear Information System (INIS)

Bliss, M; Betts, T R; Gottschalg, R

2010-01-01

The first three-dimensional performance matrix for use in photovoltaic (PV) energy rating is reported utilizing a novel energy rating solar simulator based on LEDs. Device characteristics are measured indoors at varying irradiance (G), temperature (T) and spectrum (E). This opens the possibility for a more accurate measurement system for energy yield prediction of PV devices, especially for devices with high spectral dependence such as wide bandgap solar cells as they take into account spectral changes in the light. The main aspects of the LED-based solar simulator used are briefly described. A measurement method is developed and detailed in the paper, which takes into account the current imperfections in the achievable spectrum. Measurement results for a crystalline silicon solar cell are used to demonstrate the measurement approach. An uncertainty analysis of the measurement system is given, resulting in an overall absolute uncertainty of 4.3% (coverage factor k = 2) in maximum power measurements at 765 W m −2 irradiance with scope for further improvements

A Novel Wireless Power Transfer-Based Weighed Clustering Cooperative Spectrum Sensing Method for Cognitive Sensor Networks.

Science.gov (United States)

Liu, Xin

2015-10-30

In a cognitive sensor network (CSN), the wastage of sensing time and energy is a challenge to cooperative spectrum sensing, when the number of cooperative cognitive nodes (CNs) becomes very large. In this paper, a novel wireless power transfer (WPT)-based weighed clustering cooperative spectrum sensing model is proposed, which divides all the CNs into several clusters, and then selects the most favorable CNs as the cluster heads and allows the common CNs to transfer the received radio frequency (RF) energy of the primary node (PN) to the cluster heads, in order to supply the electrical energy needed for sensing and cooperation. A joint resource optimization is formulated to maximize the spectrum access probability of the CSN, through jointly allocating sensing time and clustering number. According to the resource optimization results, a clustering algorithm is proposed. The simulation results have shown that compared to the traditional model, the cluster heads of the proposed model can achieve more transmission power and there exists optimal sensing time and clustering number to maximize the spectrum access probability.

A Novel Wireless Power Transfer-Based Weighed Clustering Cooperative Spectrum Sensing Method for Cognitive Sensor Networks

Directory of Open Access Journals (Sweden)

Xin Liu

2015-10-01

Full Text Available In a cognitive sensor network (CSN, the wastage of sensing time and energy is a challenge to cooperative spectrum sensing, when the number of cooperative cognitive nodes (CNs becomes very large. In this paper, a novel wireless power transfer (WPT-based weighed clustering cooperative spectrum sensing model is proposed, which divides all the CNs into several clusters, and then selects the most favorable CNs as the cluster heads and allows the common CNs to transfer the received radio frequency (RF energy of the primary node (PN to the cluster heads, in order to supply the electrical energy needed for sensing and cooperation. A joint resource optimization is formulated to maximize the spectrum access probability of the CSN, through jointly allocating sensing time and clustering number. According to the resource optimization results, a clustering algorithm is proposed. The simulation results have shown that compared to the traditional model, the cluster heads of the proposed model can achieve more transmission power and there exists optimal sensing time and clustering number to maximize the spectrum access probability.

Dependence of effective spectrum width of synchrotron radiation on particle energy

Energy Technology Data Exchange (ETDEWEB)

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.)

Study of the muon spectrum at a depth 570 m.w.e. underground by means of the 100-ton scintillation detector

International Nuclear Information System (INIS)

Enikeev, R.I.; Zatsepin, G.T.; Korol'kova, E.V.; Kudryavtsev, V.A.; Mal'gin, A.S.; Ryazhskaya, O.G.; Khal'chukov, F.F.

1988-01-01

The experiment was carried out using the 100-ton apparatus at the Artemovsk Scientific Station of the Institute of Nuclear Research, USSR Academy of Sciences, located in a salt mine at a depth 570 m.w.e. underground. The spectrum of the energy release in the electromagnetic cascades which are generated by muons underground was measured. The electromagnetic and nuclear cascades were separated on the basis of the number of neutrons in these cascades. The spectrum of the energy release obtained is consistent with a spectrum of π and K mesons with γ/sub π//sub ,//sub K/ = 1.75 +- 0.08 for muon energies at sea level E 0 /sub μ/ >0.7 TeV. The experimental data recalculated to the vertical spectrum of muons at sea level agree with the results of other studies. Up to energies of about 100 TeV neither the spectrum of the primary cosmic rays nor the characteristics of the pA interaction undergo changes which could lead to an increase of γ/sub π//sub ,//sub K/ to a value exceeding 1.85

Energy spectrum analysis between single and dual energy source x-ray imaging for PCB non-destructive test

Energy Technology Data Exchange (ETDEWEB)

Park, Kyeong Jin; Kim, Myung Soo; Lee, Min Ju; Kang, Dong Uk; Lee, Dae Hee; Kim, Ye Won; Kim, Chan Kyu; Kim, Hyoung Taek; Kim, Gi Yoon; Cho, Gyu Seong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-08-15

Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB nondestructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency.

Energy spectrum analysis between single and dual energy source x-ray imaging for PCB non-destructive test

International Nuclear Information System (INIS)

Park, Kyeong Jin; Kim, Myung Soo; Lee, Min Ju; Kang, Dong Uk; Lee, Dae Hee; Kim, Ye Won; Kim, Chan Kyu; Kim, Hyoung Taek; Kim, Gi Yoon; Cho, Gyu Seong

2015-01-01

Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB nondestructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency

Neutron energy spectrum flux profile of Ghana's miniature neutron source reactor core

International Nuclear Information System (INIS)

Sogbadji, R.B.M.; Abrefah, R.G.; Ampomah-Amoako, E.; Agbemava, S.E.; Nyarko, B.J.B.

2011-01-01

Highlights: → The total neutron flux spectrum of the compact core of Ghana's miniature neutron source reactor was studied. → Using 20,484 energy grids, the thermal, slowing down and fast neutron energy regions were studied. - Abstract: The total neutron flux spectrum of the compact core of Ghana's miniature neutron source reactor was understudied using the Monte Carlo method. To create small energy groups, 20,484 energy grids were used for the three neutron energy regions: thermal, slowing down and fast. The moderator, the inner irradiation channels, the annulus beryllium reflector and the outer irradiation channels were the region monitored. The thermal neutrons recorded their highest flux in the inner irradiation channel with a peak flux of (1.2068 ± 0.0008) x 10 12 n/cm 2 s, followed by the outer irradiation channel with a peak flux of (7.9166 ± 0.0055) x 10 11 n/cm 2 s. The beryllium reflector recorded the lowest flux in the thermal region with a peak flux of (2.3288 ± 0.0004) x 10 11 n/cm 2 s. The peak values of the thermal energy range occurred in the energy range (1.8939-3.7880) x 10 -08 MeV. The inner channel again recorded the highest flux of (1.8745 ± 0.0306) x 10 09 n/cm 2 s at the lower energy end of the slowing down region between 8.2491 x 10 -01 MeV and 8.2680 x 10 -01 MeV, but was over taken by the moderator as the neutron energies increased to 2.0465 MeV. The outer irradiation channel recorded the lowest flux in this region. In the fast region, the core, where the moderator is found, the highest flux was recorded as expected, at a peak flux of (2.9110 ± 0.0198) x 10 08 n/cm 2 s at 6.961 MeV. The inner channel recorded the second highest while the outer channel and annulus beryllium recorded very low flux in this region. The flux values in this region reduce asymptotically to 20 MeV.

The high-energy pulsed X-ray spectrum of Hercules X-1 as observed with OSO 8

Science.gov (United States)

Maurer, G. S.; Dennis, B. R.; Coe, M. J.; Crannell, C. J.; Dolan, J. F.; Frost, K. J.; Orwig, L. E.; Cutler, E. P.

1979-01-01

Hercules X-1 was observed from August 30 to September 10, 1977, by using the high-energy X-ray scintillation spectrometer on board the OSO 8 satellite. The observation, during which the source was monitored continually for nearly an entire ON-state, covered the energy range from 16 to 280 keV. Pulsed-flux measurements as a function of binary orbit and binary phase are presented for energies between 16 and 98 keV. The pulsed flux between 16 and 33 keV exhibited a sharp decrease following the fourth binary orbit and was consistent with zero pulsed flux thereafter. Only weak evidence was found for temporal variation in the pulsed flux between 33 and 98 keV. The pulsed spectrum has been fitted with a power law, a thermal spectrum without features, and a thermal spectrum with a superposed Gaussian centered at 55 keV. The latter fit has the smallest value of chi-square per degree of freedom, and the resulting integrated line intensity is approximately 0.0015 photon/sec per sq cm for a width of 3.1 (+9.1, -2.6) keV. This result, while of low statistical significance, agrees with the value observed by Truemper (1978) during the same ON-state.

Was The Electromagnetic Spectrum A Blackbody Spectrum In The Early Universe?

International Nuclear Information System (INIS)

Opher, M.; Opher, R.

1997-01-01

It is generally assumed that the electromagnetic spectrum in the primordial universe was a blackbody spectrum in vacuum. We derive the electromagnetic spectrum based on the fluctuation-dissipation theorem that describes the electromagnetic fluctuations in a plasma. Our description includes thermal and collisional effects in a plasma. The electromagnetic spectrum obtained differs from a blackbody spectrum in vacuum at low frequencies. In particular, concentrating on the primordial nucleosynthesis era, it has more energy than the blackbody spectrum for frequencies less than 3ω pe to 6ω pe , where ω pe is the electron plasma frequency. copyright 1997 The American Physical Society

Use of orthonormal polynomials to fit energy spectrum data for water transported through membrane

International Nuclear Information System (INIS)

Bogdanova, N.; Todorova, L.

2001-01-01

A new application of our approach with orthonormal polynomials to curve fitting is given when both variables have errors. We approximate and describe data of a new effect due to change of water energy spectrum as a result of water transport in a porous membrane

A Proposed Algorithm for Improved Recognition and Treatment of the Depression/Anxiety Spectrum in Primary Care

Science.gov (United States)

Ballenger, James C.; Davidson, Jonathan R. T.; Lecrubier, Yves; Nutt, David J.

2001-01-01

The International Consensus Group on Depression and Anxiety has held 7 meetings over the last 3 years that focused on depression and specific anxiety disorders. During the course of the meeting series, a number of common themes have developed. At the last meeting of the Consensus Group, we reviewed these areas of commonality across the spectrum of depression and anxiety disorders. With the aim of improving the recognition and management of depression and anxiety in the primary care setting, we developed an algorithm that is presented in this article. We attempted to balance currently available scientific knowledge about the treatment of these disorders and to reformat it to provide an acceptable algorithm that meets the practical aspects of recognizing and treating these disorders in primary care. PMID:15014615

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

International Nuclear Information System (INIS)

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)

Analysis of a gamma-ray spectrum by using a standard spectrum

International Nuclear Information System (INIS)

Tasaka, Kanji

1975-06-01

The standard spectrum method has been extended to take into account the energy dependence of a standard spectrum. The method analyses the observed gamma-ray spectrum by the least-square method, using an interpolated standard spectrum for expressing the line shape and a linear function for the background continuum. The interpolated standard spectrum is defined for each fitting interval by interpolating several standard spectra, which are derived directly from the observed spectra of single photopeaks each corresponding to the incident monochromatic gamma-rays by subtracting the background and smoothing the data. (author)

First measurement of the VESUVIO neutron spectrum in the 30-80 MeV energy range using a Proton Recoil Telescope technique

Science.gov (United States)

Cazzaniga, C.; Tardocchi, M.; Croci, G.; Frost, C.; Giacomelli, L.; Grosso, G.; Hjalmarsson, A.; Rebai, M.; Rhodes, N. J.; Schooneveld, E. M.; Gorini, G.

2013-11-01

Measurements of the fast neutron energy spectrum at the ISIS spallation source are reported. The measurements were performed with a Proton Recoil Telescope consisting of a thin plastic foil placed in the neutron beam and two scintillator detectors. Results in the neutron energy range 30 MeV < En < 80 MeV are in good agreement with Monte Carlo simulations of the neutron spectrum.

Hydrogen Production Costs of Various Primary Energy Sources

International Nuclear Information System (INIS)

Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

2005-11-01

Many studies on the economical aspects of hydrogen energy technologies have been conducted with the increase of the technical and socioeconomic importance of the hydrogen energy. However, there is still no research which evaluates the economy of hydrogen production from the primary energy sources in consideration of Korean situations. In this study, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations such as feedstock price, electricity rate, and load factor. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S. The present study focuses on the possible future technology scenario defined by NAS. The scenario assumes technological improvement that may be achieved if present research and development (R and D) programs are successful. The production costs by the coal and natural gas are 1.1 $/kgH 2 and 1.36 $/kgH 2 , respectively. However, the fossil fuels are susceptible to the price variation depending on the oil and the raw material prices, and the hydrogen production cost also depends on the carbon tax. The economic competitiveness of the renewable energy sources such as the wind, solar, and biomass are relatively low when compared with that of the other energy sources. The estimated hydrogen production costs from the renewable energy sources range from 2.35 $/kgH 2 to 6.03 $/kgH 2 . On the other hand, the production cost by nuclear energy is lower than that of natural gas or coal when the prices of the oil and soft coal are above $50/barrel and 138 $/ton, respectively. Taking into consideration the recent rapid increase of the oil and soft coal prices and the limited fossil resource, the nuclear-hydrogen option appears to be the most economical way in the future

The intergalactic propagation of ultrahigh energy cosmic ray nuclei

Energy Technology Data Exchange (ETDEWEB)

Hooper, Dan; /Fermilab; Sarkar, Subir; /Oxford U., Theor. Phys.; Taylor, Andrew M.; /Oxford U.

2006-08-01

We investigate the propagation of ultra-high energy cosmic ray nuclei (A = 1-56) from cosmologically distant sources through the cosmic radiation backgrounds. Various models for the injected composition and spectrum and of the cosmic infrared background are studied using updated photodisintegration cross-sections. The observational data on the spectrum and the composition of ultra-high energy cosmic rays are jointly consistent with a model where all of the injected primary cosmic rays are iron nuclei (or a mixture of heavy and light nuclei).

Spectrum and energy levels of six-times-ionized molybdenum (Mo VII)

International Nuclear Information System (INIS)

Reader, J.

1990-01-01

The spectrum of the kryptonlike ion Mo VII was observed from 140 to 2274 A with sliding-spark discharges on 10.7-m normal- and grazing-incidence spectrographs. Experimental energies were determined for all levels of the 4s 2 4p 6 , 4s 2 4p 5 4d, 4f, 5s, 5p, 5d, 5f, 5g, and 4s4p 6 4d configurations. A few levels of the 4s 2 4p 4 4d 2 configuration were also found. A total of 399 lines were classified as transitions between 86 observed levels. The observed configurations were theoretically interpreted. The energy parameters determined by least-squares fits to the observed levels are compared with Hartree--Fock calculations. A revised value of the ionization energy was obtained by using the energy of the 4p 5 5g configuration together with an isoelectronically extrapolated value of the effective quantum number n(5g). The adopted limit is 1 013 340±200 cm -1 (125.64±0.02 eV)

Search for ultra high energy primary photons at the Pierre Auger Observatory

Directory of Open Access Journals (Sweden)

Colalillo Roberta

2016-01-01

Full Text Available The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture in the search for primary photons with energy above 1017 eV over a large portion of the southern sky. Such photons can be detected in principle via the air showers they initiate at such energies, using the complement of Auger Observatory detectors. We discuss the results obtained in diffuse and directional searches for primary photons in the EeV energy range.

The energy spectrum of electromagnetic normal modes in dissipative media: modes between two metal half spaces

International Nuclear Information System (INIS)

Sernelius, Bo E

2008-01-01

The energy spectrum of electromagnetic normal modes plays a central role in the theory of the van der Waals and Casimir interaction. Here we study the modes in connection with the van der Waals interaction between two metal half spaces. Neglecting dissipation leads to distinct normal modes with real-valued frequencies. Including dissipation seems to have the effect that these distinct modes move away from the real axis into the complex frequency plane. The summation of the zero-point energies of these modes render a complex-valued result. Using the contour integration, resulting from the use of the generalized argument principle, gives a real-valued and different result. We resolve this contradiction and show that the spectrum of true normal modes forms a continuum with real frequencies

Search for the end of the cosmic ray energy spectrum

International Nuclear Information System (INIS)

Linsley, John

1998-01-01

The title I was asked to speak about expresses an idea that occurred rather recently in the history of cosmic ray studies. I argue that the idea of a possible end of the cosmic ray energy spectrum came into being after a sequence of three rapid advances in knowledge which I describe, calling them 'breakthroughs'. I suggest that the present workshop be regarded as a step toward a fourth breakthrough. I argue that this may occur through application of the Space Airwatch concept--the earth atmosphere as target and signal generator--as embodied in the NASA OWL project

On the energy spectrum of the Bethe-Salpeter equation; Ob ehnergeticheskom spektre uravneniya Bete-Solpitera

Energy Technology Data Exchange (ETDEWEB)

Dorkin, S M [Dal` nevostochnyj Gosudarstvennyj Univ., Vladivostok (Russian Federation); Kaptar` , L P; Semikh, S S [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Lab. of Theoretical Physics

1997-12-31

The problem of calculating the energy spectrum of a two-fermion bound state within the Bethe-Salpeter formalism is discussed. An expansion of the kernel of the spinor-spinor Bethe-Salpeter equation in the ladder approximation is found in terms of a bi-orthogonal basis of the generalized Gilbert-Schmidt series for symmetric equations of the Fredholm type. According to this expansion, a new method of solving the Bethe-Salpeter equation and finding the mass spectrum is proposed. Methodological result of numerical solutions of equations with scalar interaction is presented. (author). 20 refs., 3 figs.

Throughput Maximization Using an SVM for Multi-Class Hypothesis-Based Spectrum Sensing in Cognitive Radio

Directory of Open Access Journals (Sweden)

Sana Ullah Jan

2018-03-01

Full Text Available A framework of spectrum sensing with a multi-class hypothesis is proposed to maximize the achievable throughput in cognitive radio networks. The energy range of a sensing signal under the hypothesis that the primary user is absent (in a conventional two-class hypothesis is further divided into quantized regions, whereas the hypothesis that the primary user is present is conserved. The non-radio frequency energy harvesting-equiped secondary user transmits, when the primary user is absent, with transmission power based on the hypothesis result (the energy level of the sensed signal and the residual energy in the battery: the lower the energy of the received signal, the higher the transmission power, and vice versa. Conversely, the lower is the residual energy in the node, the lower is the transmission power. This technique increases the throughput of a secondary link by providing a higher number of transmission events, compared to the conventional two-class hypothesis. Furthermore, transmission with low power for higher energy levels in the sensed signal reduces the probability of interference with primary users if, for instance, detection was missed. The familiar machine learning algorithm known as a support vector machine (SVM is used in a one-versus-rest approach to classify the input signal into predefined classes. The input signal to the SVM is composed of three statistical features extracted from the sensed signal and a number ranging from 0 to 100 representing the percentage of residual energy in the node’s battery. To increase the generalization of the classifier, k-fold cross-validation is utilized in the training phase. The experimental results show that an SVM with the given features performs satisfactorily for all kernels, but an SVM with a polynomial kernel outperforms linear and radial-basis function kernels in terms of accuracy. Furthermore, the proposed multi-class hypothesis achieves higher throughput compared to the

Primary energy-transformations in biological systems

Energy Technology Data Exchange (ETDEWEB)

Lehninger, A.L.

1980-10-01

In this paper I shall review the main outlines of current research on the molecular aspects of the primary energy-coupling mechanisms in cells, those carried out by energy-transducing membranes. They include the capture of solar energy by the chloroplast membranes of green plants, used to generate carbohydrates and molecular oxygen from carbon dioxide and water, and the counterpart of photosynthesis, the process of respiration in heterotrophic organisms, in which reduced organic products generated by photosynthesis are oxidized at the expense of dioxygen to form carbon dioxide and water. Although the cycling of dioxygen, carbon dioxide, and organic matter between the plant and animal worlds is well known, it is not generally appreciated that the magnitude of biological energy flux in these cycles is huge compared to the total energy flux in man-made devices. A major consequence is that the concentration of carbon dioxide in the atmosphere has been increasing at a significant rate, at a time when there is also a decrease, at least in some parts of the world, in the counterbalancing utilization of CO/sub 2/ by green plants, due to deforestation. The greenhouse effect of increased atmospheric CO/sub 2/ may not only change the earth's climate, but also may influence the rate of photosynthesis. It is also not generally appreciated that energy flow in the biosphere leads to production of enormous amounts of organic matter potentially useful in furnishing man's energy requirements.

Two-dimensional angular energy spectrum of electrons accelerated by the ultra-short relativistic laser pulse

Energy Technology Data Exchange (ETDEWEB)

Borovskiy, A. V. [Department of Computer Science and Cybernetics, Baikal State University of Economics and Law, 11 Lenin Street, Irkutsk 664003 (Russian Federation); Galkin, A. L. [Coherent and Nonlinear Optics Department, A.M. Prokhorov General Physics Institute of the RAS, 38 Vavilov Street, Moscow 119991 (Russian Federation); Department of Physics of MBF, Pirogov Russian National Research Medical University, 1 Ostrovitianov Street, Moscow 117997 (Russian Federation); Kalashnikov, M. P., E-mail: galkin@kapella.gpi.ru [Max-Born-Institute for Nonlinear Optics and Short-Time Spectroscopy, 2a Max-Born-Strasse, Berlin 12489 (Germany)

2015-04-15

The new method of calculating energy spectra of accelerated electrons, based on the parameterization by their initial coordinates, is proposed. The energy spectra of electrons accelerated by Gaussian ultra-short relativistic laser pulse at a selected angle to the axis of the optical system focusing the laser pulse in a low density gas are theoretically calculated. The two-peak structure of the electron energy spectrum is obtained. Discussed are the reasons for its appearance as well as an applicability of other models of the laser field.

Turbulent kinetic energy spectrum in very anisothermal flows

International Nuclear Information System (INIS)

Serra, Sylvain; Toutant, Adrien; Bataille, Françoise; Zhou, Ye

2012-01-01

In this Letter, we find that the Kolmogorov scaling law is no longer valid when the flow is submitted to strong dilatational effects caused by high temperature gradients. As a result, in addition to the nonlinear time scale, there is a much shorter “temperature gradients” time scale. We propose a model that estimates the time scale of the triple decorrelation incorporating the influences of the temperature gradient. The model agrees with the results from the thermal large-eddy simulations of different Reynolds numbers and temperature gradients. This Letter provides a better understanding of the very anisothermal turbulent flow. -- Highlights: ► Turbulent flows subject to high temperature gradients are considered. ► The new “temperature gradients” time scale is determined. ► A generalized energy spectrum is developed to incorporate the effects of temperature gradient.

The energy spectrum of cosmic-ray induced neutrons measured on an airplane over a wide range of altitude and latitude

International Nuclear Information System (INIS)

Goldhagen, P.; Clem, J. M.; Wilson, J. W.

2004-01-01

Crews of high-altitude aircraft are exposed to radiation from galactic cosmic rays (GCRs). To help determine such exposures, the Atmospheric Ionizing Radiation Project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on a NASA ER-2 high-altitude airplane. The primary instrument was a sensitive extended-energy multisphere neutron spectrometer. Its detector responses were calculated for energies up to 100 GeV using the radiation transport code MCNPX 2.5.d with improved nuclear models and including the effects of the airplane structure. New calculations of GCR-induced particle spectra in the atmosphere were used to correct for spectrometer counts produced by protons, pions and light nuclear ions. Neutron spectra were unfolded from the corrected measured count rates using the deconvolution code MAXED 3.1. The results for the measured cosmic-ray neutron spectrum (thermal to >10 GeV), total neutron fluence rate, and neutron dose equivalent and effective dose rates, and their dependence on altitude and geomagnetic cut-off agree well with results from recent calculations of GCR-induced neutron spectra. (authors)

Analysis of alpha spectrum instrumental errors accounting for the low energy part of semiconductor detector response function

International Nuclear Information System (INIS)

Gurbich, A.F.

1981-01-01

A technique for processing of instrumental spectrum of charged particles permitting to take account of a low-energy part of spectrometer line shape, to improve accuracy and to estimate detection efficiency is stated on the example of 226 Ra alpha spectrum. The results obtained show that relative intensities of alpha lines within the limits of statistical errors coincide with the known values, line ''tails'' constituting to 3% of total area of the line. Taking account of ''the line tail'' results in shift of centers of peak gravity by 10-20 keV. So low-energy part of the alpha spectrometer line, which is usually not taken account during spectra processing, markedly affect the results [ru

Contribution from individual nearby sources to the spectrum of high-energy cosmic-ray electrons

International Nuclear Information System (INIS)

Sedrati, R.; Attallah, R.

2014-01-01

In the last few years, very important data on high-energy cosmic-ray electrons and positrons from high-precision space-born and ground-based experiments have attracted a great deal of interest. These particles represent a unique probe for studying local comic-ray accelerators because they lose energy very rapidly. These energy losses reduce the lifetime so drastically that high-energy cosmic-ray electrons can attain the Earth only from rather local astrophysical sources. This work aims at calculating, by means of Monte Carlo simulation, the contribution from some known nearby astrophysical sources to the cosmic-ray electron/positron spectra at high energy (≥10GeV). The background to the electron energy spectrum from distant sources is determined with the help of the GALPROP code. The obtained numerical results are compared with a set of experimental data

Contribution from individual nearby sources to the spectrum of high-energy cosmic-ray electrons

Energy Technology Data Exchange (ETDEWEB)

Sedrati, R., E-mail: rafik.sedrati@univ-annaba.org; Attallah, R.

2014-04-01

In the last few years, very important data on high-energy cosmic-ray electrons and positrons from high-precision space-born and ground-based experiments have attracted a great deal of interest. These particles represent a unique probe for studying local comic-ray accelerators because they lose energy very rapidly. These energy losses reduce the lifetime so drastically that high-energy cosmic-ray electrons can attain the Earth only from rather local astrophysical sources. This work aims at calculating, by means of Monte Carlo simulation, the contribution from some known nearby astrophysical sources to the cosmic-ray electron/positron spectra at high energy (≥10GeV). The background to the electron energy spectrum from distant sources is determined with the help of the GALPROP code. The obtained numerical results are compared with a set of experimental data.

The Use of Energy in Malaysia: Tracing Energy Flows from Primary Source to End Use

OpenAIRE

Chinhao Chong; Weidou Ni; Linwei Ma; Pei Liu; Zheng Li

2015-01-01

Malaysia is a rapidly developing country in Southeast Asia that aims to achieve high-income country status by 2020; its economic growth is highly dependent on its abundant energy resources, especially natural gas and crude oil. In this paper, a complete picture of Malaysia’s energy use from primary source to end use is presented by mapping a Sankey diagram of Malaysia’s energy flows, together with ongoing trends analysis of the main factors influencing the energy flows. The results indicate t...

First measurement of the VESUVIO neutron spectrum in the 30–80 MeV energy range using a Proton Recoil Telescope technique

International Nuclear Information System (INIS)

Cazzaniga, C; Tardocchi, M; Croci, G; Grosso, G; Rebai, M; Gorini, G; Frost, C; Rhodes, N J; Schooneveld, E M; Giacomelli, L; Hjalmarsson, A

2013-01-01

Measurements of the fast neutron energy spectrum at the ISIS spallation source are reported. The measurements were performed with a Proton Recoil Telescope consisting of a thin plastic foil placed in the neutron beam and two scintillator detectors. Results in the neutron energy range 30 MeV n < 80 MeV are in good agreement with Monte Carlo simulations of the neutron spectrum

Thermodynamic properties of a solid exhibiting the energy spectrum given by the logistic map

International Nuclear Information System (INIS)

Curado, E.M.F.

2000-05-01

We show that the infinite-dimensional representation of the recently introduced Logistic algebra can be interpreted as a non-trivial generalization of the Heisenberg or oscillator algebra. This allows to construct a quantum Hamiltonian having the energy energy spectrum given by the logistic map. We analyze the Hamiltonian of a solid whose collective modes of vibrations are described by this generalized oscillator and compute the thermodynamic properties of the model in the two-cycle and γ3.6785 chaotic region of the logistic map. (author)

Effect of laser peripheral iridotomy on anterior chamber angle anatomy in primary angle closure spectrum eyes

Science.gov (United States)

Kansara, Seema; Blieden, Lauren S.; Chuang, Alice Z.; Baker, Laura A.; Bell, Nicholas P.; Mankiewicz, Kimberly A.; Feldman, Robert M.

2015-01-01

Purpose To evaluate the change in trabecular-iris circumference volume (TICV) after laser peripheral iridotomy (LPI) in primary angle closure (PAC) spectrum eyes Patients and Methods Forty-two chronic PAC spectrum eyes from 24 patients were enrolled. Eyes with anterior chamber abnormalities affecting angle measurement were excluded. Intraocular pressure, slit lamp exam, and gonioscopy were recorded at each visit. Anterior segment optical coherence tomography (ASOCT) with 3D mode angle analysis scans were taken with the CASIA SS-1000 (Tomey Corp., Nagoya, Japan) before and after LPI. Forty-two pre-LPI ASOCT scans and 34 post-LPI ASOCT scans were analyzed using the Anterior Chamber Analysis and Interpretation (ACAI, Houston, TX) software. A mixed-effect model analysis was used to compare the trabecular-iris space area (TISA) changes among 4 quadrants, as well as to identify potential factors affecting TICV. Results There was a significant increase in all average angle parameters after LPI (TISA500, TISA750, TICV500, and TICV750). The magnitude of change in TISA500 in the superior angle was significantly less than the other angles. The changes in TICV500 and TICV750 were not associated with any demographic or ocular characteristics. Conclusion TICV is a useful parameter to quantitatively measure the effectiveness of LPI in the treatment of eyes with PAC spectrum disease. PMID:26066504

Time resolved energy spectrum of the axial ion beam generated in plasma focus discharges

International Nuclear Information System (INIS)

Bostick, W.H.; Kilic, H.; Nardi, V.; Powell, C.W.

1993-01-01

The energy spectrum of the deuteron beam along the electrode axis (0 (degree) ) in a plasma focus discharge has been determined with a time of flight (TOF) method and with a differential filter method in the ion energy interval E = 0.3-9 MeV. The ion TOF method is applied to single-ion pulse events with an ion emission time t(E) that is only weakly dependent on the ion energy E for E > 0.3 MeV. The correlation of the ion beam intensity with the filling pressure, the neutron yield and the hard X-ray intensity is also reported. (author). 11 refs, 10 figs

Primary energy consumption of the dwelling with solar hot water system and biomass boiler

International Nuclear Information System (INIS)

Berković-Šubić, Mihaela; Rauch, Martina; Dović, Damir; Andrassy, Mladen

2014-01-01

Highlights: • Methodology for determing delivered and primary energy is developed. • Conventional and solar hot water system are analyzed. • Influence of system components, heat losses and energy consumption is explored. • Savings when using solar system in delivered energy is 30% and in primary 75%. • Dwelling with higher Q H,nd has 60% shorter payback period. - Abstract: This paper presents a new methodology, based on the energy performance of buildings Directive related European norms. It is developed to overcome ambiguities and incompleteness of these standards in determining the delivered and primary energy. The available procedures from the present “Algorithm for determining the energy demands and efficiency of technical systems in buildings”, normally used for energy performance certification of buildings, also allow detailed analyzes of the influence of particular system components on the overall system energy efficiency. The calculation example is given for a Croatian reference dwelling, equipped with a solar hot water system, backed up with a biomass boiler for space heating and domestic hot water purposes as a part of the dwelling energy performance certification. Calculations were performed for two cases corresponding to different levels of the dwelling thermal insulation with an appropriate heating system capacity, in order to investigate the influence of the building heat losses on the system design and energy consumption. The results are compared against those obtained for the conventional system with a gas boiler in terms of the primary energy consumption as well as of investment and operating costs. These results indicate great reduction in both delivered and primary energy consumption when a solar system with biomass boiler is used instead of the conventional one. Higher savings are obtained in the case of the dwelling with higher energy need for space heating. Such dwellings also have a shorter payback period than the ones with

Improved spatial resolution and lower-dose pediatric CT imaging: a feasibility study to evaluate narrowing the X-ray photon energy spectrum

Energy Technology Data Exchange (ETDEWEB)

Benz, Mark G. [Safer Pediatric Imaging and Engineering Horizons International, Lincoln, VT (United States); Benz, Matthew W. [Southboro Medical Group, Southboro, MA (United States); Birnbaum, Steven B. [Dartmouth Hitchcock Clinic Manchester, Department of Radiology, Manchester, NH (United States); Chason, Eric; Sheldon, Brian W. [Brown University, Division of Engineering, Materials Science and Engineering Program, Providence, RI (United States); McGuire, Dale [R and D Manager, C and G Technologies Inc., Jeffersonville, IN (United States)

2014-08-15

This feasibility study has shown that improved spatial resolution and reduced radiation dose can be achieved in pediatric CT by narrowing the X-ray photon energy spectrum. This is done by placing a hafnium filter between the X-ray generator and a pediatric abdominal phantom. A CT system manufactured in 1999 that was in the process of being remanufactured was used as the platform for this study. This system had the advantage of easy access to the X-ray generator for modifications to change the X-ray photon energy spectrum; it also had the disadvantage of not employing the latest post-imaging noise reduction iterative reconstruction technology. Because we observed improvements after changing the X-ray photon energy spectrum, we recommend a future study combining this change with an optimized iterative reconstruction noise reduction technique. (orig.)

Measurement of the pulse night spectrum Cerenkov flashes in the atmosphere

International Nuclear Information System (INIS)

Schlemmer, G.

1981-03-01

The determination of the energy spectrum of Cosmic Rays is difficult because of the low particle density at high energies. Normally such observations would require detectors with large collecting areas and long measurement periods. However the difficulty can be overcome by measuring shower induced Cerenkov radiation, the photon density of which is proportional to the shower energy. The Cerenkov radiation measurements reported here were made using two photomultipliers connected to a coincidence counter unit. The shower energy was deduced from measurements of the height of the pulses observed at the multiplier output,which should be proportional to the number of Cerenkov photons arriving at the photocathode. In order to make meaningful statements about the shower energy the statistical response of the photomultiplier system had to be standardized. This calibration was carried out by illuminating the photomultiplier cathode with a pulsed LED of pulsewidth 5 ns. For different light intensities of the LED a pulse-height spectrum was taken at the multiplier output. In addition to the Cerenkov photons counted by the photomultipliers, there exists a strong constant background light intensity. This background can be eliminated by employing a coincidence amplifier with a resolution time of 10 ns. To reduce background induced accidental coincidences the apparatus was equipped with a variable trigger level. To test the apparatus the Cerenkov radiation induced by cosmic rays in a water basin and in the photomultiplier window itself was measured and compared to theoretical estimates. The agreement was good. The pulse height spectrum of atmospheric Cerenkov radiation was obtained at the Cosmic Ray Physics Laboratory at the Hafelekar Observatory near Innsbruck. The measurements obtained there allowed the exponnent $delta in the differential energy spectrum N(E) dE c.Esup(-$delta)dE of the primary Cosmic Radiation to be evaluated. The value of $delta in the energy range 2,5 x 10 14

The energy spectrum of delayed neutrons from thermal neutron induced fission of 235U and its analytical approximation

International Nuclear Information System (INIS)

Doroshenko, A.Yu.; Tarasko, M.Z.; Piksaikin, V.M.

2002-01-01

The energy spectrum of the delayed neutrons is the poorest known of all input data required in the calculation of the effective delayed neutron fractions. In addition to delayed neutron spectra based on the aggregate spectrum measurements there are two different approaches for deriving the delayed neutron energy spectra. Both of them are based on the data related to the delayed neutron spectra from individual precursors of delayed neutrons. In present work these two different data sets were compared with the help of an approximation by gamma-function. The choice of this approximation function instead of the Maxwellian or evaporation type of distribution is substantiated. (author)

Hydrogen Production Costs of Various Primary Energy Sources

International Nuclear Information System (INIS)

Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

2005-01-01

The limited resource and environmental impacts of fossil fuels are becoming more and more serious problems in the world. Consequently, hydrogen is in the limelight as a future alternative energy due to its clean combustion and inexhaustibility and a transition from the traditional fossil fuel system to a hydrogen-based energy system is under considerations. Several countries are already gearing the industries to the hydrogen economy to cope with the limitations of the current fossil fuels. Unfortunately, hydrogen has to be chemically separated from the hydrogen compounds in nature such as water by using some energy sources. In this paper, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S

Effect of photon energy spectrum on dosimetric parameters of brachytherapy sources.

Science.gov (United States)

Ghorbani, Mahdi; Mehrpouyan, Mohammad; Davenport, David; Ahmadi Moghaddas, Toktam

2016-06-01

The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters. Different photon spectra are used for a specific radionuclide in Monte Carlo simulations of brachytherapy sources. MCNPX code was used to simulate 125I, 103Pd, 169Yb, and 192Ir brachytherapy sources. Air kerma strength per activity, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated and isodose curves were plotted for three different photon energy spectra. The references for photon energy spectra were: published papers, Lawrence Berkeley National Laboratory (LBNL), and National Nuclear Data Center (NNDC). The data calculated by these photon energy spectra were compared. Dose rate constant values showed a maximum difference of 24.07% for 103Pd source with different photon energy spectra. Radial dose function values based on different spectra were relatively the same. 2D anisotropy function values showed minor differences in most of distances and angles. There was not any detectable difference between the isodose contours. Dosimetric parameters obtained with different photon spectra were relatively the same, however it is suggested that more accurate and updated photon energy spectra be used in Monte Carlo simulations. This would allow for calculation of reliable dosimetric data for source modeling and calculation in brachytherapy treatment planning systems.

Combined diversity and improved energy detection in cooperative spectrum sensing with faded reporting channels

Directory of Open Access Journals (Sweden)

Srinivas Nallagonda

2016-04-01

Full Text Available In this paper we evaluate the performance of cooperative spectrum sensing (CSS where each cognitive radio (CR employs an improved energy detector (IED with multiple antennas and uses selection combining (SC for detecting the primary user (PU in noisy and faded sensing (S channels. We derive an expression for the probability of false alarm and expressions for probability of missed detection in non-faded (AWGN and Rayleigh faded sensing environments in terms of cumulative distribution function (CDF. Each CR transmits its decision about PU via noisy and faded reporting (R channel to fusion center (FC. In this paper we assume that S-channels are noisy and Rayleigh faded while several cases of fading are considered for R-channels such as: (i Hoyt (or Nakagami-q, (ii Rayleigh, (iii Rician (or Nakagami-n, and (iv Weibull. A Binary Symmetric channel (BSC with a fixed error probability (r in the R-channel is also considered. The impact of fading in R-channel, S-channel and several network parameters such as IED parameter, normalized detection threshold, number of CRs, and number of antennas on missed detection and total error probability is assessed. The effects of Hoyt, Rician, and Weibull fading parameters on overall performance of IED-CSS are also highlighted.

Hadronic cosmic ray interactions near the LHC energy region and in the UHE domain of giant EAS

Energy Technology Data Exchange (ETDEWEB)

Capdevielle, J.N. [AstroParticule et Cosmologie (APC), College de France, 75 - Paris (France)

2005-07-01

The fluctuations of ray families simulated with CORSIKA in the energy region 3.10{sup 15} - 10{sup 17} eV on the basis of standard Lns collider physics exhibits alignments of secondaries in the stratosphere and at ground level. The remarkable event recorded on the Concorde does not fit well however those cases. The possible hints of new mechanisms, especially the valence diquark breaking, are considered. Observing that the extrapolation of the original cosmic ray primary spectrum derived from the size spectrum measured in the Akeno classical EAS array coincides with the spectrum measured recently by the Hires Stereo experiment, we point out a possible overestimation of the primary energy in inclined showers of the surface arrays like AGASA. (author)

Scaling and charge ratio in the energy range 1-10 TeV

International Nuclear Information System (INIS)

Baradzej, L.T.; Kanevskaya, E.A.; Smorodin, Yu.A.

1976-01-01

The purpose of the investigation was to study the spectra of generation of neutral and charged pions in the upper atmosphere in order to establish the scaling behaviour of the multiple birth of particles at primary particle energies above the acceleration energies. The study of the spectrum gamma-quanta in the atmosphere and the muon spectrum at the sea level made it possible to adjust the pion generation spectrum. In experiments with emulsion chambers the spectra of gamma-quanta and electrons at different zenith angles at two levels in the atmosphere (225 and 700 gxcm -2 ) and the muon spectrum at the sea level were determined. The obtained data on pion birth in the atmosphere pointed to the conservation of scale and charge invariance in pion birth at nucleon energies of 10 12 -10 14 eV

Effects of virtual isobar admixtures on the low-energy spectrum of a complex nucleus - model calculations for 12C

International Nuclear Information System (INIS)

Grecksch, E.

1978-01-01

On the basis of a detailed analysis of the excitation spectrum of a complex nucleus in the framework of the conventional shell model theory, the paper extends this concept by adding nucleonic degrees of freedom (isobars) and by model investigations and a realistic assessment of their effects on the excited states of the low-energy spectrum. (AH) [de

Neutron energy spectrum from 120 GeV protons on a thick copper target

Energy Technology Data Exchange (ETDEWEB)

Shigyo, Nobuhiro; /Kyushu U.; Sanami, Toshiya; /KEK, Tsukuba; Kajimoto, Tsuyoshi; /Kyushu U.; Iwamoto, Yosuke; /JAEA, Ibaraki; Hagiwara, Masayuki; Saito, Kiwamu; /KEK, Tsukuba; Ishibashi, Kenji; /Kyushu U.; Nakashima, Hiroshi; Sakamoto, Yukio; /JAEA, Ibaraki; Lee, Hee-Seock; /Pohang Accelerator Lab.; Ramberg, Erik; /Fermilab

2010-08-01

Neutron energy spectrum from 120 GeV protons on a thick copper target was measured at the Meson Test Beam Facility (MTBF) at Fermi National Accelerator Laboratory. The data allows for evaluation of neutron production process implemented in theoretical simulation codes. It also helps exploring the reasons for some disagreement between calculation results and shielding benchmark data taken at high energy accelerator facilities, since it is evaluated separately from neutron transport. The experiment was carried out using a 120 GeV proton beam of 3E5 protons/spill. Since the spill duration was 4 seconds, protoninduced events were counted pulse by pulse. The intensity was maintained using diffusers and collimators installed in the beam line to MTBF. The protons hit a copper block target the size of which is 5cm x 5cm x 60 cm long. The neutrons produced in the target were measured using NE213 liquid scintillator detectors, placed about 5.5 m away from the target at 30{sup o} and 5 m 90{sup o} with respect to the proton beam axis. The neutron energy was determined by time-of-flight technique using timing difference between the NE213 and a plastic scintillator located just before the target. Neutron detection efficiency of NE213 was determined on basis of experimental data from the high energy neutron beam line at Los Alamos National Laboratory. The neutron spectrum was compared with the results of multiparticle transport codes to validate the implemented theoretical models. The apparatus would be applied to future measurements to obtain a systematic data set for secondary particle production on various target materials.

Peak creation in the energy spectrum of laser-produced protons by phase rotation

International Nuclear Information System (INIS)

Noda, Akira; Nakamura, Shu; Iwashita, Yoshihisa; Shirai, Toshiyuki; Tongu, Hiromu; Ito, Hiroyuki; Souda, Hikaru; Yamazaki, Atsushi; Tanabe, Mikio; Daido, Hiroyuki; Mori, Michiaki; Kado, Masataka; Sagisaka, Akito; Ogura, Koichi; Nishiuchi, Mamiko; Orimo, Satoshi; Hayashi, Yukio; Yogo, Akifumi; Bulanov, Sergei; Esirkepov, Timur; Nagashima, Akira; Kimura, Toyoaki; Tajima, Toshiki; Fukumi, Atsushi; Li, Zhong

2007-01-01

In collaboration between JAEA, Kansai Photon Science Institute and Institute for Chemical Research, Kyoto University, proton generation from a thin foil target (Ti 3 or 5 μm in thickness) with use of 10 TW laser (JLITEX) has been performed. Proton production is optimized by real time proton energy measurement with use of TOF method. Phase rotation with use of an RF electric field phase-synchronized to the pulse laser enabled the creation of peaks with the spread of ∼7% in the energy spectrum of the produced protons, which resulted in the increase of the intensity ∼4 times at peak position. (author)

Experimental determination of spectral ratios and of neutrons energy spectrum in the fuel of the IPEN/MB-01 nuclear reactor

International Nuclear Information System (INIS)

Nunes, Beatriz Guimaraes

2012-01-01

This study aims to determine the spectral ratios and the neutron energy spectrum inside the fuel of IPEN/MB-01 Nuclear Reactor. These parameters are of great importance to accurately determine spectral physical parameters of nuclear reactors like reaction rates, fuel lifetime and also security parameters such as reactivity. For the experiment, activation detectors in the form of thin metal foils were introduced in a collapsible fuel rod. Then the rod was placed in the central position of the core which has a standard rectangular configuration of 26 x 28 fuel rods. There were used activation detectors from different elements such Au-197, U-238, Sc-45, Ni-58, Mg-24, Ti-47 and In-115 to cover a large range of the neutron energy spectrum. After the irradiation, the activation detectors were submitted to gamma spectrometry using a counting system with high purity Germanium, to obtain the reaction rates (saturation activity) per target nucleus. The spectral ratios were compared with calculated values obtained by the Monte Carlo method using the MCNP-4C code. The neutron energy spectrum was obtained inside the fuel rod using the SANDBP code with an input spectrum obtained by the MCNP-4C code, based on the saturation activity per target nucleus values of the activation detectors irradiated. (author)

Primary energy savings using heat storage for biomass heating systems

Directory of Open Access Journals (Sweden)

Mitrović Dejan M.

2012-01-01

Full Text Available District heating is an efficient way to provide heat to residential, tertiary and industrial users. The heat storage unit is an insulated water tank that absorbs surplus heat from the boiler. The stored heat in the heat storage unit makes it possible to heat even when the boiler is not working, thus increasing the heating efficiency. In order to save primary energy (fuel, the boiler operates on nominal load every time it is in operation (for the purpose of this research. The aim of this paper is to analyze the water temperature variation in the heat storage, depending on the heat load and the heat storage volume. Heat load is calculated for three reference days, with average daily temperatures from -5 to 5°C. The primary energy savings are also calculated for those days in the case of using heat storage in district heating.[Projekat Ministarstva nauke Republike Srbije, br. TR 33051: The concept of sustainable energy supply of settlements with energy efficient buildings

Energy spectrum of 208Pb(n,x) reactions

Science.gov (United States)

Tel, E.; Kavun, Y.; Özdoǧan, H.; Kaplan, A.

2018-02-01

Fission and fusion reactor technologies have been investigated since 1950's on the world. For reactor technology, fission and fusion reaction investigations are play important role for improve new generation technologies. Especially, neutron reaction studies have an important place in the development of nuclear materials. So neutron effects on materials should study as theoretically and experimentally for improve reactor design. For this reason, Nuclear reaction codes are very useful tools when experimental data are unavailable. For such circumstances scientists created many nuclear reaction codes such as ALICE/ASH, CEM95, PCROSS, TALYS, GEANT, FLUKA. In this study we used ALICE/ASH, PCROSS and CEM95 codes for energy spectrum calculation of outgoing particles from Pb bombardment by neutron. While Weisskopf-Ewing model has been used for the equilibrium process in the calculations, full exciton, hybrid and geometry dependent hybrid nuclear reaction models have been used for the pre-equilibrium process. The calculated results have been discussed and compared with the experimental data taken from EXFOR.

Thermodynamics of greenhouse systems for the northern latitudes: analysis, evaluation and prospects for primary energy saving.

Science.gov (United States)

Bronchart, Filip; De Paepe, Michel; Dewulf, Jo; Schrevens, Eddie; Demeyer, Peter

2013-04-15

In Flanders and the Netherlands greenhouse production systems produce economically important quantities of vegetables, fruit and ornamentals. Indoor environmental control has resulted in high primary energy use. Until now, the research on saving primary energy in greenhouse systems has been mainly based on analysis of energy balances. However, according to the thermodynamic theory, an analysis based on the concept of exergy (free energy) and energy can result in new insights and primary energy savings. Therefore in this paper, we analyse the exergy and energy of various processes, inputs and outputs of a general greenhouse system. Also a total system analysis is then performed by linking the exergy analysis with a dynamic greenhouse climate growth simulation model. The exergy analysis indicates that some processes ("Sources") lie at the origin of several other processes, both destroying the exergy of primary energy inputs. The exergy destruction of these Sources is caused primarily by heat and vapour loss. Their impact can be compensated by exergy input from heating, solar radiation, or both. If the exergy destruction of these Sources is reduced, the necessary compensation can also be reduced. This can be accomplished through insulating the greenhouse and making the building more airtight. Other necessary Sources, namely transpiration and loss of CO2, have a low exergy destruction compared to the other Sources. They are therefore the best candidate for "pump" technologies ("vapour heat pump" and "CO2 pump") designed to have a low primary energy use. The combination of these proposed technologies results in an exergy efficient greenhouse with the highest primary energy savings. It can be concluded that exergy analyses add additional information compared to only energy analyses and it supports the development of primary energy efficient greenhouse systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO⁺(H₂O) cluster using accurate potential energy and dipole moment surfaces.

Science.gov (United States)

Homayoon, Zahra

2014-09-28

A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO(+)(H2O) cluster is reported. The PES is based on fitting of roughly 32,000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO(+)(H2O) and NO(+)(D2O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO(+)(H2O) and NO(+)(D2O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO(+)(H2O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good agreement with experiment. Mode coupling of the water "antisymmetric" stretching mode with the low-frequency intermolecular modes results in intensity borrowing.

MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO+(H2O) cluster using accurate potential energy and dipole moment surfaces

Science.gov (United States)

Homayoon, Zahra

2014-09-01

A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO+(H2O) cluster is reported. The PES is based on fitting of roughly 32 000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO+(H2O) and NO+(D2O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO+(H2O) and NO+(D2O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO+(H2O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good agreement with experiment. Mode coupling of the water "antisymmetric" stretching mode with the low-frequency intermolecular modes results in intensity borrowing.

MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO+(H2O) cluster using accurate potential energy and dipole moment surfaces

International Nuclear Information System (INIS)

Homayoon, Zahra

2014-01-01

A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO + (H 2 O) cluster is reported. The PES is based on fitting of roughly 32 000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO + (H 2 O) and NO + (D 2 O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO + (H 2 O) and NO + (D 2 O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO + (H 2 O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good agreement with experiment. Mode coupling of the water “antisymmetric” stretching mode with the low-frequency intermolecular modes results in intensity borrowing

Broad Energy Range Neutron Spectroscopy using a Liquid Scintillator and a Proportional Counter: Application to a Neutron Spectrum Similar to that from an Improvised Nuclear Device.

Science.gov (United States)

Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A; Garty, Guy; Harken, Andrew; Brenner, David J

2015-09-11

A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n) 3 He and D(d,n) 3 He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the 9 Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima.

Correlation of high energy muons with primary composition in extensive air shower

Science.gov (United States)

Chou, C.; Higashi, S.; Hiraoka, N.; Ozaki, S.; Sato, T.; Suwada, T.; Takahasi, T.; Umeda, H.

1985-01-01

An experimental investigation of high energy muons above 200 GeV in extensive air showers has been made for studying high energy interaction and primary composition of cosmic rays of energies in the range 10 to the 14th power approx. 10 to the 15th power eV. The muon energies are estimated from the burst sizes initiated by the muons in the rock, which are measured by four layers of proportional counters, each of area 5 x 2.6 sq m, placed at 30 m.w.e. deep, Funasaka tunnel vertically below the air shower array. These results are compared with Monte Carlo simulations based on the scaling model and the fireball model for two primary compositions, all proton and mixed.

Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

Energy Technology Data Exchange (ETDEWEB)

Teng, J.; Gu, Y.Q., E-mail: tengjian@mail.ustc.edu.cn; Zhu, B.; Hong, W.; Zhao, Z.Q.; Zhou, W.M.; Cao, L.F.

2013-11-21

This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

Science.gov (United States)

Teng, J.; Gu, Y. Q.; Zhu, B.; Hong, W.; Zhao, Z. Q.; Zhou, W. M.; Cao, L. F.

2013-11-01

This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

International Nuclear Information System (INIS)

Teng, J.; Gu, Y.Q.; Zhu, B.; Hong, W.; Zhao, Z.Q.; Zhou, W.M.; Cao, L.F.

2013-01-01

This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator

Interference-aware random beam selection schemes for spectrum sharing systems

KAUST Repository

Abdallah, Mohamed

2012-10-19

Spectrum sharing systems have been recently introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this work, we develop interference-aware random beam selection schemes that provide enhanced performance for the secondary network under the condition that the interference observed by the receivers of the primary network is below a predetermined/acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a primary link composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes select a beam, among a set of power-optimized random beams, that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the SINR statistics as well as the capacity and bit error rate (BER) of the secondary link.

Estimation of the sea level muon spectra at different zenith angles below 10 TeV energy

CERN Document Server

Mitra, M; Pal, P B; Bhattacharya, D P

2001-01-01

The moderate energy primary cosmic ray nucleon spectrum has been calculated from the direct measurements of Webber et al. (1987), Seo et al. (1992) and Menn et al. (1997). Along with the other results surveyed by Swordy (1993). Using these directly measured primary mass composition results all particle primary nucleon energy spectrum has been constructed using superposition model to estimate the energy spectra of muons from the decay of the cosmic ray non-prompt and prompt mesons in the atmosphere. The Z-factors have been estimated from the CERN LEBC-EHS on the Lorentz invariant cross section results on pp to pi /sup +or-/X and pp to K/sup +or-/X inclusive reactions and FNAL data on pi /sup +or-/p to pi /sup +or-/X reactions, and duly corrected for A-A collisions. Using these Z-factors the meson energy spectra in the atmosphere have been calculated. The sea level muon energy spectra at zenith angles 0 degrees , 45 degrees , 72 degrees , and 75 degrees have been derived from the decay of non-prompt mesons by a...

Strength functions of primary transitions following thermal neutron capture in strontium

International Nuclear Information System (INIS)

Winter, C.; Lieb, K.P.

1989-01-01

The primary E1, M1 and E2 γ-radiation in 87,88,89 Sr observed after thermal neutron capture was compared with the predictions of single particle and giant resonance models. The nuclei feature a wide range of neutron binding energies between 6.3 and 11.1 MeV, which makes a 5.5 MeV spectrum of primary transition energies available for investigation. The (n, γ) reaction was used to estimate the parameters of the spin-flip M1 giant resonance in strontium. The total energy weighted M1 strength of this resonance exceeds the results of shell model and random phase approximation calculations for 90 Zr by a factor of 3-4. The E1 strengths were found to agree with the established giant dipole resonance model. The few data on primary E2 transitions do not allow to differentiate between the giant quadrupole resonance and the single particle models. (orig.)

Production of photons with a narrow energy spectrum, starting from high energy electrons; Production de photons de spectre etroit a partir d'electrons de grande energie

Energy Technology Data Exchange (ETDEWEB)

Tzara, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

A method for the production of photons with a narrow spectrum and of variable energy, based on the properties of the annihilation in flight of positrons, is examined in detail. The spectra of the photons produced and the yield of the process are given for various conditions. (author) [French] Une methode de production de photons de spectre etroit et d'energie variable, basee sur les proprietes de l'annihilation en vol des positons, est examinee en detail. Le spectre des photons produits, le rendement du processus sont donnes pour diverses conditions. (auteur)

Performance of primary repair on colon injuries sustained from low-versus high-energy projectiles.

Science.gov (United States)

Lazovic, Ranko; Radojevic, Nemanja; Curovic, Ivana

2016-04-01

Among various reasons, colon injuries may be caused by low- or high-energy firearm bullets, with the latter producing a temporary cavitation phenomenon. The available treatment options include primary repair and two-stage management, but recent studies have shown that primary repair can be widely used with a high success rate. This paper investigates the differences in performance of primary repair on these two types of colon injuries. Two groups of patients who sustained colon injuries due to single gunshot wounds, were retrospectively categorized based on the type of bullet. Primary colon repair was performed in all patients selected based on the inclusion and exclusion criteria (Stone and Fabian's criteria). An almost absolute homogeneity was attained among the groups in terms of age, latent time before surgery, and four trauma indexes. Only one patient from the low-energy firearm projectile group (4%) developed a postsurgical complication versus nine patients (25.8%) from the high-energy group, showing statistically significant difference (p = 0.03). These nine patients experienced the following postsurgical complications: pneumonia, abscess, fistula, suture leakage, and one multiorgan failure with sepsis. Previous studies concluded that one-stage primary repair is the best treatment option for colon injuries. However, terminal ballistics testing determined the projectile's path through the body and revealed that low-energy projectiles caused considerably lesser damage than their high-energy counterparts. Primary colon repair must be performed definitely for low-energy short firearm injuries but very carefully for high-energy injuries. Given these findings, we suggest that the treatment option should be determined based not only on the bullet type alone but also on other clinical findings. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Ab initio ground state phenylacetylene-argon intermolecular potential energy surface and rovibrational spectrum

DEFF Research Database (Denmark)

Cybulski, Hubert; Fernandez, Berta; Henriksen, Christian

2012-01-01

to the axis perpendicular to the phenylacetylene plane and containing the center of mass. The calculated interaction energy is -418.9 cm(-1). To check further the potential, we obtain the rovibrational spectrum of the complex and the results are compared to the available experimental data. (C) 2012 American......We evaluate the phenylacetylene-argon intermolecular potential energy surface by fitting a representative number of ab initio interaction energies to an analytic function. These energies are calculated at a grid of intermolecular geometries, using the CCSD(T) method and the aug-cc-pVDZ basis set...... extended with a series of 3s3p2d1flg midbond functions. The potential is characterized by two equivalent global minima where the Ar atom is located above and below the phenylacetylene plane at a distance of 3.5781 angstrom from the molecular center of mass and at an angle of 9.08 degrees with respect...

The persistent current and energy spectrum on a driven mesoscopic LC-circuit with Josephson junction

Science.gov (United States)

Pahlavanias, Hassan

2018-03-01

The quantum theory for a mesoscopic electric circuit including a Josephson junction with charge discreteness is studied. By considering coupling energy of the mesoscopic capacitor in Josephson junction device, a Hamiltonian describing the dynamics of a quantum mesoscopic electric LC-circuit with charge discreteness is introduced. We first calculate the persistent current on a quantum driven ring including Josephson junction. Then we obtain the persistent current and energy spectrum of a quantum mesoscopic electrical circuit which includes capacitor, inductor, time-dependent external source and Josephson junction.

Prominent soft x-ray lines of Sr-like Au41+ in low-energy EBIT spectrum

International Nuclear Information System (INIS)

Vilkas, Marius Jonas; Ishikawa, Yasuyuki; Traebert, Elmar

2007-01-01

Relativistic multireference Moeller-Plesset perturbation theory has been employed to calculate with high accuracy the energy levels and transition probabilities of Cu- to Sr-like gold ions. The many-body calculations were carried out to identify the unassigned blended lines in the 35-40 A region of the low-energy EBIT spectrum of the gold ions [Traebert et al 2001 Can. J. Phys.79153]. Most of the prominent lines in the 35-40 A region were identified as the emission lines in Sr-like gold

Fine structure and energy spectrum of exciton in direct band gap cubic semiconductors with degenerate valence bands

International Nuclear Information System (INIS)

Nguyen Toan Thang; Nguyen Ai Viet; Nguyen Que Huong

1987-06-01

The influence of the cubic structure on the energy spectrum of direct exciton is investigated, using the new method suggested by Nguyen Van Hieu and co-workers. Explicit expressions of the exciton energy levels 1S, 2S and 2P are derived. A comparison with the experiments and the other theory is done for ZnSe. (author). 10 refs, 1 fig., 2 tabs

Rev-Changes in Primary Energy Use and CO2 Emissions—An Impact Assessment for a Building with Focus on the Swedish Proposal for Nearly Zero Energy Buildings

Directory of Open Access Journals (Sweden)

Mattias Gustafsson

2017-07-01

Full Text Available In the European Union’s Energy Performance of Buildings Directive, the energy efficiency goal for buildings is set in terms of primary energy use. In the proposal from the National Board of Housing, Building, and Planning, for nearly zero energy buildings in Sweden, the use of primary energy is expressed as a primary energy number calculated with given primary energy factors. In this article, a multi-dwelling building is simulated and the difference in the primary energy number is investigated when the building uses heat from district heating systems or from heat pumps, alone or combined with solar thermal or solar photovoltaic systems. It is also investigated how the global CO2 emissions are influenced by the different energy system combinations and with different fuels used. It is concluded that the calculated primary energy number is lower for heat pump systems, but the global CO2 emissions are lowest when district heating uses mostly biofuels and is combined with solar PV systems. The difference is up to 140 tonnes/year. If the aim with the Swedish building code is to decrease the global CO2 emissions then the ratio between the primary energy factors for electricity and heat should be larger than three and considerably higher than today.

New primary energy source by thorium molten-salt reactor technology

International Nuclear Information System (INIS)

Furukawa, Kazuo; Kato, Yoshio; Furuhashi, Akira; Numata, Hiroo; Mitachi, Koushi; Yoshioka, Ritsuo; Sato, Yuzuru; Arakawa, Kazuto

2005-01-01

Among the next 30 years, we have to implement a practical measure in the global energy/environmental problems, solving the followings: (1) replacing the fossil fuels without CO 2 emission, (2) no severe accidents, (3) no concern on military, (4) minimizing wastes, (5) economical, (6) few R and D investment and (7) rapid/huge global application supplying about half of the total primary energy till 50 years later. For this purpose the following system was proposed: THORIMS-NES [Thorium Molten-Salt Nuclear Energy Synergetic System], which is composed of (A) simple fission Molten-Salt power stations (FUJI), and (B) fissile-producing Accelerator Molten-Salt Breeder (AMSB). It has been internationally prepared a practical Developmental Program for its huge-size industrialization of Th breeding fuel cycle to produce a new rational primary energy. Here it is explained the social meaning, the conceptual system design and technological bases, especially, including the molten fluoride salt technology, which was developed as the triple-functional medium for nuclear-engineering, heat-transfer and chemical engineering. The complex function of this system is fully achieved by the simplified facility using a single phase molten-salt only. (author)

BONDI-97 A novel neutron energy spectrum unfolding tool using a genetic algorithm

CERN Document Server

Mukherjee, B

1999-01-01

The neutron spectrum unfolding procedure using the count rate data obtained from a set of Bonner sphere neutron detectors requires the solution of the Fredholm integral equation of the first kind by using complex mathematical methods. This paper reports a new approach for the unfolding of neutron spectra using the Genetic Algorithm tool BONDI-97 (BOnner sphere Neutron DIfferentiation). The BONDI-97 was used as the input for Genetic Algorithm engine EVOLVER to search for a globally optimised solution vector from a population of randomly generated solutions. This solution vector corresponds to the unfolded neutron energy spectrum. The Genetic Algorithm engine emulates the Darwinian 'Survival of the Fittest' strategy, the key ingredient of the 'Theory of Evolution'. The spectra of sup 2 sup 4 sup 1 Am/Be (alpha,n) and sup 2 sup 3 sup 9 Pu/Be (alpha,n) neutron sources were unfolded using the BONDI-97 tool. (author)

Automatic segmentation of low-visibility moving objects through energy analyis of the local 3D spectrum

Science.gov (United States)

Nestares, Oscar; Miravet, Carlos; Santamaria, Javier; Fonolla Navarro, Rafael

1999-05-01

Automatic object segmentation in highly noisy image sequences, composed by a translating object over a background having a different motion, is achieved through joint motion-texture analysis. Local motion and/or texture is characterized by the energy of the local spatio-temporal spectrum, as different textures undergoing different translational motions display distinctive features in their 3D (x,y,t) spectra. Measurements of local spectrum energy are obtained using a bank of directional 3rd order Gaussian derivative filters in a multiresolution pyramid in space- time (10 directions, 3 resolution levels). These 30 energy measurements form a feature vector describing texture-motion for every pixel in the sequence. To improve discrimination capability and reduce computational cost, we automatically select those 4 features (channels) that best discriminate object from background, under the assumptions that the object is smaller than the background and has a different velocity or texture. In this way we reject features irrelevant or dominated by noise, that could yield wrong segmentation results. This method has been successfully applied to sequences with extremely low visibility and for objects that are even invisible for the eye in absence of motion.

Capacity Development and Strengthening for Energy Policy formulation and implementation of Sustainable Energy Projects in Indonesia CASINDO. Deliverable No. 13. Integration of Renewable Energy Technologies in the national curriculum SPECTRUM

Energy Technology Data Exchange (ETDEWEB)

Kamphuis, E. [ETC Nederland, Leusden (Netherlands); Permana, I. [Technical Education Development Centre TEDC, Bandung (Indonesia)

2011-11-15

The overall objective of the CASINDO programme is to establish a self-sustaining and self-developing structure at both the national and regional level to build and strengthen human capacity to enable the provinces of North Sumatra, Yogyakarta, Central Java, West Nusa Tenggara and Papua to formulate sound policies for renewable energy and energy efficiency and to develop and implement sustainable energy projects. This report focuses on the achievements for settling a national curriculum for Renewable Energy Technologies (RET) within the framework of national programme SPECTRUM, which includes all curricula of the medium technical schools in Indonesia.

Spectrum and energy levels of five-times-ionized niobium (Nb VI)

International Nuclear Information System (INIS)

Ekberg, J.O.; Reader, J.

1994-01-01

The spectrum of the kryptonlike ion Nb VI was observed from 325 to 2700 with sliding-spark discharges on 10.7-m normal-incidence and grazing-incidence spectrographs. Experimental energies were determined for all levels of the 4s 2 4p 6 , 4s 2 4p 5 4d, 4f, 5s, 5p, 5d, 5g, 6s, and 4s4p 6 4d configurations as well as for some levels of the 4s 2 4p 5 6g and 6h configurations. A total of 303 lines are now classified as transitions between 99 observed levels. Large hyperfine splittings were found for several levels of the 4p 5 5s and 5p configurations. The observed configurations were theoretically interpreted by means of Hartree--Fock calculations and least-squares fits of the energy parameters to the observed levels. An improved value of the ionization energy was determined from the 4p 5 5g, 6g, and 6h configurations. The adopted value of the limit is 823 240 ± 50 cm - 1 (102.069 ± 0.006 eV)

Spread Spectrum Based Energy Efficient Collaborative Communication in Wireless Sensor Networks.

Science.gov (United States)

Ghani, Anwar; Naqvi, Husnain; Sher, Muhammad; Khan, Muazzam Ali; Khan, Imran; Irshad, Azeem

2016-01-01

Wireless sensor networks consist of resource limited devices. Most crucial of these resources is battery life, as in most applications like battle field or volcanic area monitoring, it is often impossible to replace or recharge the power source. This article presents an energy efficient collaborative communication system based on spread spectrum to achieve energy efficiency as well as immunity against jamming, natural interference, noise suppression and universal frequency reuse. Performance of the proposed system is evaluated using the received signal power, bit error rate (BER) and energy consumption. The results show a direct proportionality between the power gain and the number of collaborative nodes as well as BER and signal-to-noise ratio (Eb/N0). The analytical and simulation results of the proposed system are compared with SISO system. The comparison reveals that SISO perform better than collaborative communication in case of small distances whereas collaborative communication performs better than SISO in case of long distances. On the basis of these results it is safe to conclude that collaborative communication in wireless sensor networks using wideband systems improves the life time of nodes in the networks thereby prolonging the network's life time.

A Monte Carlo study of the energy spectra and transmission characteristics of scattered radiation from x-ray computed tomography.

Science.gov (United States)

Platten, David John

2014-06-01

Existing data used to calculate the barrier transmission of scattered radiation from computed tomography (CT) are based on primary beam CT energy spectra. This study uses the EGSnrc Monte Carlo system and Epp user code to determine the energy spectra of CT scatter from four different primary CT beams passing through an ICRP 110 male reference phantom. Each scatter spectrum was used as a broad-beam x-ray source in transmission simulations through seventeen thicknesses of lead (0.00-3.50 mm). A fit of transmission data to lead thickness was performed to obtain α, β and γ parameters for each spectrum. The mean energy of the scatter spectra were up to 12.3 keV lower than that of the primary spectrum. For 120 kVp scatter beams the transmission through lead was at least 50% less than predicted by existing data for thicknesses of 1.5 mm and greater; at least 30% less transmission was seen for 140 kVp scatter beams. This work has shown that the mean energy and half-value layer of CT scatter spectra are lower than those of the corresponding primary beam. The transmission of CT scatter radiation through lead is lower than that calculated with currently available data. Using the data from this work will result in less lead shielding being required for CT scanner installations.

TVWS devices spectrum mask test and analysis

CSIR Research Space (South Africa)

Lamola, MM

2016-09-01

Full Text Available Dynamic Spectrum Access (DSA) plays a vital role in opportunistic access to spectrum. A key component of DSA is preventing interference to the incumbent (primary) user from the secondary user. We present the results of an experiment to analyze...

Spectrum and energy levels of six-times ionized yttrium (Y VII)

Science.gov (United States)

Reader, Joseph

2018-03-01

The spectrum of six-times ionized yttrium, Y VII, was photographed with a sliding-spark discharge on 10.7 m normal- and grazing-incidence spectrographs. The region of observation was 157-824 Å. The observations extend the known configurations 4s24p3, 4s4p4, 4p5, 4s24p25s, 4s24p26s to the nearly complete 4s24p24d configuration. Our results for 4s24p24d significantly revise results of Rahimullah et al (1978 Phys. Scr. 18 96); Ateqad et al (1984 J. Phys. B: At. Mol. Phys. 17 4617). A total of 168 lines and 56 energy levels are now known for this ion. The observed configurations were interpreted with Hartree-Fock calculations and least-squares fits of the energy parameters to the observed levels. Transition probabilities for all classified lines were calculated with the fitted parameters.

Enhanced primary and secondary performance through cognitive relaying and leveraging primary feedback

KAUST Repository

Hamza, Doha R.

2014-06-01

We consider a spectrum-sharing system, where the primary terminal operates in a time-slotted fashion and is active only when it has a packet to send. The secondary terminal uses spectrum sensing results and the primary automatic repeat request (ARQ) feedback to access the channel probabilistically. To enhance the primary\\'s system performance, the secondary user (SU) acts as a relay for the primary user (PU) in the event of transmission failure on the direct link of the latter. Closed-form expressions for the primary and secondary throughputs are obtained for the described scheme. The optimal medium access probabilities are then obtained by maximizing the secondary throughput subject to constraints that guarantee the stability of the considered queues, a minimum primary throughput, and a maximum primary queueing delay. The results clearly indicate the benefits of cognitive relaying in enhancing the throughput performance for both the PU and SU. Furthermore, by guaranteeing minimum rate and maximum delay requirements, our scheme is shown to provide a definitive notion of protection for the licensed users of the network. © 2013 IEEE.

Quantum control of isomerization by robust navigation in the energy spectrum

Energy Technology Data Exchange (ETDEWEB)

Murgida, G. E., E-mail: murgida@tandar.cnea.gov.ar [Centro Atómico Constituyentes, GIyA, CNEA, San Martín, and Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Buenos Aires (Argentina); Arranz, F. J., E-mail: fj.arranz@upm.es [Grupo de Sistemas Complejos, Universidad Politécnica de Madrid, 28040 Madrid (Spain); Borondo, F., E-mail: f.borondo@uam.es [Departamento de Química, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Instituto de Ciencias Matemáticas (ICMAT), Cantoblanco, 28049 Madrid (Spain)

2015-12-07

In this paper, we present a detailed study on the application of the quantum control technique of navigation in the energy spectrum to chemical isomerization processes, namely, CN–Li⇆ Li–CN. This technique is based on the controlled time variation of a Hamiltonian parameter, an external uniform electric field in our case. The main result of our work establishes that the navigation involved in the method is robust, in the sense that quite sizable deviations from a pre-established control parameter time profile can be introduced and still get good final results. This is specially relevant thinking of a experimental implementation of the method.

Spectrum reconstruction with X rays and flat panel wedge PMMA by Monte Carlo codes and Penelope MCNPS; Reconstruccion del esptro de rayos X con flat panel y cuna de PMMa mediante los codigos de monte Carlo Penelope y MCNP5

Energy Technology Data Exchange (ETDEWEB)

Pozuelo, F.; Querol, A.; Juste, B.; Gallardo, S.; Rodenas, J.; Verdu, G.

2012-07-01

Obtaining the primary spectrum of X-rays to determine the quality of a photon beam produced by an X-ray tube, since the dosimetric characteristics of a radiation beam to have a direct relation to the primary X-ray spectrum. In this work are studied, the depth dose curves obtained in the energy range of diagnostic radiology, between 40 and 130 keV.

Comparative study of various methods of primary energy estimation in nucleon-nucleon interactions

International Nuclear Information System (INIS)

Goyal, D.P.; Yugindro Singh, K.; Singh, S.

1986-01-01

The various available methods for the estimation of primary energy in nucleon-nucleon interactions have been examined by using the experimental data on angular distributions of shower particles from p-N interactions at two accelerator energies, 67 and 400 GeV. Three different groups of shower particle multiplicities have been considered for interactions at both energies. It is found that the different methods give quite different estimates of primary energy. Moreover, each method is found to give different values of energy according to the choice of multiplicity groups. It is concluded that the E ch method is relatively the better method among all the methods available, and that within this method, the consideration of the group of small multiplicities gives a much better result. The method also yields plausible estimates of inelasticity in high energy nucleon-nucleon interactions. (orig.)

Electricity of nuclear origin and primary and end-use energy consumption; Electricite nucleaire et consommation d'energie primaire et finale

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

In France, the electricity of nuclear origin corresponds to about 40% of the primary energy consumption, while electricity as a whole represents about 23% of the end-use energy. This apparent paradox can be explained by 2 methodological points: 1 - the primary energy consumption, in the case of electricity, includes only the energy of nuclear, hydraulic, wind, photovoltaic and geothermal origin. On the other hand, the end-use energy consumption includes all forms of electricity consumed, i.e. the electricity of both primary and secondary origin. 2 - By international convention, the coefficients used to convert MWth into tpe (ton of petroleum equivalent) can change according to two factors: the power generation source and the type of kWh considered, either produced or consumed. The coexistence of different concepts and definitions is justified by the different usages made with them. Therefore, calculations referring to different definitions or equivalence coefficients are not immediately comparable. (J.S.)

Testing model energy spectra of charged particles produced in hadron interactions on the basis of atmospheric muons

International Nuclear Information System (INIS)

Dedenko, L. G.; Roganova, T. M.; Fedorova, G. F.

2015-01-01

An original method for calculating the spectrum of atmospheric muons with the aid of the CORSIKA 7.4 code package and numerical integration is proposed. The first step consists in calculating the energy distribution of muons for various fixed energies of primary-cosmic-ray particles and within several chosen hadron-interaction models included in the CORSIKA 7.4 code package. After that, the spectrum of atmospheric muons is calculated via integrating the resulting distribution densities with the chosen spectrum of primary-cosmic-ray particles. The atmospheric-muon fluxes that were calculated on the basis of the SIBYLL 2.1, QGSJET01, and QGSJET II-04 models exceed the predictions of the wellknown Gaisser approximation of this spectrum by a factor of 1.5 to 1.8 in the range of muon energies between about 10 3 and 10 4 GeV.Under the assumption that, in the region of extremely highmuon energies, a dominant contribution to the muon flux comes from one to two generations of charged π ± and K ± mesons, the production rate calculated for these mesons is overestimated by a factor of 1.3 to 1.5. This conclusion is confirmed by the results of the LHCf and TOTEM experiments

A multigroup analysis from a continuos energy spectrum approach by a MC method

International Nuclear Information System (INIS)

Camargo, Dayana Q. de; Bodmann, Bardo E.J.; Vilhena, Marco T. de

2009-01-01

In this work, the Monte Carlo method is applied to the energy dependent three- dimensional neutron transport equation, in order to analyze the change in the spectrum energy depending on the Monte Carlo step. The present work is a first step into a new direction where spectral influence on criticality may be analyzed. The method is based on the monitoring of a large number of individual realizations of neutron histories (i.e. microscopic interaction sequence) where the average behavior of neutrons yields an approximate solution for the neutron transport equation. The Monte Carlo is implemented using continuous functions, with respect to energy, for the cross sections of materials, functions which are obtained by parametrizations of the cross sections. The type of interaction that the neutron will suffer and the characteristics of their displacement in the element are estimated randomly following the relevant probability distributions. (author)

Role of primary sedimentation on plant-wide energy recovery and carbon footprint.

Science.gov (United States)

Gori, Riccardo; Giaccherini, Francesca; Jiang, Lu-Man; Sobhani, Reza; Rosso, Diego

2013-01-01

The goal of this paper is to show the effect of primary sedimentation on the chemical oxygen demand (COD) and solids fractionation and consequently on the carbonaceous and energy footprints of wastewater treatment processes. Using a simple rational procedure for COD and solids fraction quantification, we quantify the effects of varying fractions on CO2 and CO2-equivalent mass flows, process energy demand and energy recovery. Then we analysed two treatment plants with similar biological nutrient removal processes in two different climatic regions and quantified the net benefit of gravity separation before biological treatment. In the cases analysed, primary settling increases the solid fraction of COD that is processed in anaerobic digestion, with an associated increase in biogas production and energy recovery, and a reduction in overall emissions of CO2 and CO2-equivalent from power importation.

Nuclear Power and Resource Efficiency—A Proposal for a Revised Primary Energy Factor

Directory of Open Access Journals (Sweden)

Ola Eriksson

2017-06-01

Full Text Available Measuring resource efficiency can be achieved using different methods, of which primary energy demand is commonly used. The primary energy factor (PEF is a figure describing how much energy from primary resources is being used per unit of energy delivered. The PEF for nuclear power is typically 3, which refers to thermal energy released from fission in relation to electricity generated. Fuel losses are not accounted for. However; nuclear waste represents an energy loss, as current plans for nuclear waste management mostly include final disposal. Based on a literature review and mathematical calculations of the power-to-fuel ratio for nuclear power, PEF values for the open nuclear fuel cycle (NFC option of nuclear power and different power mixes are calculated. These calculations indicate that a more correct PEF for nuclear power would be 60 (range 32–88; for electricity in Sweden (41% nuclear power PEF would change from 1.8 to 25.5, and the average PEF for electricity in the European Union (EU would change from 2.5 to 18. The results illustrate the poor resource efficiency of nuclear power, which paves the way for the fourth generation of nuclear power and illustrates the policy implication of using PEFs which are inconsistent with current waste management plans.

Preparation of gaseous CRMs from the primary system for "2"2"2Rn activity measurement

International Nuclear Information System (INIS)

Kim, B.J.; Kim, B.C.; Lee, K.B.; Lee, J.M.; Park, T.S.

2016-01-01

For disseminating the gaseous radon standard traceable to the KRISS primary system based on the defined solid angle counting method, two kinds of radon CRM (a glass ampule type and a stainless steel cylinder type) were developed. The activity of the CRM was certified by subtracting a residual activity from the measured activity by the primary system. After certification, the ampule CRM was used to calibrate a radon-monitoring instrument and the cylinder CRM to calibrate an HPGe system. We also improved the measurement procedure of the radon primary system. In a typical radon energy spectrum, the radon peak overlaps with the polonium peak. For more reliable and accurate measurement of radon activity, a fitting method was adopted for the evaluation of radon area in the alpha energy spectrum. The result of radon activity evaluated by using the fitting method is in good agreement with that by the previous integration method. - Highlights: • Preparation of gaseous Rn-222 CRMs from primary measurement system. • Convolution of 3 left-handed exponentials with a Gaussian function to count radon. • Calibration of continuous radon monitor using glass ampoule CRM. • Calibration of HPGe system as secondary standard for stainless steel cylinder CRM.

Neutron energy spectrum in graphite blankets of fusion reactors

International Nuclear Information System (INIS)

Tsechanski, A.

1981-09-01

Neutron flux measurements were performed in a graphite stack and compared with calculations made with a two dimensional transport computer code. In the present work it is observed that the calculated spectrum in the elastic and inelastic scattering ranges (the first collision range in both cases), is sensitive to details of the angular distribution of these neutrons. Regarding the discrepancies in the elastic scattering range it is concluded that the microscopic cross section library ENDF/B-IV overestimates the large angle scattering (back scattering) as can be seen from comparison of measured and calculated spectra. The two most important conclusions of the present work are: 1. Inelastic scattering interaction of D-T neutrons in graphite cannot be calculated without a proper account of energy-angle correlation. 2. An experimental setup supplying monoenergetic collimated D-T neutrons constitutes a sensitive although indirect means for measuring angular distributions in inelastic and elastic scattering

An Application of the Direct Coulomb Electron Pair Production Process to the Energy Measurement of the "VH-Group" in the "Knee" Region of the "All-Particle" Energy Spectrum

Science.gov (United States)

Derrickson, J. H.; Wu, J.; Christl, M. J.; Fountain, W. F.; Parnell, T. A.

1999-01-01

The "all-particle" cosmic ray energy spectrum appears to be exhibiting a significant change in the spectral index just above approximately 3000 TeV. This could indicate (1) a change in the propagation of the cosmic rays in the galactic medium, and/or (2) the upper limit of the supernova shock wave acceleration mechanism, and/or (3) a new source of high-energy cosmic rays. Air shower and JACEE data indicate the spectral change is associated with a composition change to a heavier element mixture whereas DICE does not indicate this. A detector concept will be presented that utilizes the energy dependence of the production of direct Coulomb electron-positron pairs by energetic heavy ions. Monte Carlo simulations of a direct electron pair detector consisting of Pb target foils interleaved with planes of 1-mm square scintillating optical fibers will be discussed. The goal is to design a large area, non-saturating instrument to measure the energy spectrum of the individual cosmic ray elements in the "VH-group" for energies greater than 10 TeV/nucleon.

The Use of Energy in Malaysia: Tracing Energy Flows from Primary Source to End Use

Directory of Open Access Journals (Sweden)

Chinhao Chong

2015-04-01

Full Text Available Malaysia is a rapidly developing country in Southeast Asia that aims to achieve high-income country status by 2020; its economic growth is highly dependent on its abundant energy resources, especially natural gas and crude oil. In this paper, a complete picture of Malaysia’s energy use from primary source to end use is presented by mapping a Sankey diagram of Malaysia’s energy flows, together with ongoing trends analysis of the main factors influencing the energy flows. The results indicate that Malaysia’s energy use depends heavily on fossil fuels, including oil, gas and coal. In the past 30 years, Malaysia has successfully diversified its energy structure by introducing more natural gas and coal into its power generation. To sustainably feed the rapidly growing energy demand in end-use sectors with the challenge of global climate change, Malaysia must pay more attention to the development of renewable energy, green technology and energy conservation in the future.

Investigation on the correlation between energy deposition and clustered DNA damage induced by low-energy electrons.

Science.gov (United States)

Liu, Wei; Tan, Zhenyu; Zhang, Liming; Champion, Christophe

2018-05-01

This study presents the correlation between energy deposition and clustered DNA damage, based on a Monte Carlo simulation of the spectrum of direct DNA damage induced by low-energy electrons including the dissociative electron attachment. Clustered DNA damage is classified as simple and complex in terms of the combination of single-strand breaks (SSBs) or double-strand breaks (DSBs) and adjacent base damage (BD). The results show that the energy depositions associated with about 90% of total clustered DNA damage are below 150 eV. The simple clustered DNA damage, which is constituted of the combination of SSBs and adjacent BD, is dominant, accounting for 90% of all clustered DNA damage, and the spectra of the energy depositions correlating with them are similar for different primary energies. One type of simple clustered DNA damage is the combination of a SSB and 1-5 BD, which is denoted as SSB + BD. The average contribution of SSB + BD to total simple clustered DNA damage reaches up to about 84% for the considered primary energies. In all forms of SSB + BD, the SSB + BD including only one base damage is dominant (above 80%). In addition, for the considered primary energies, there is no obvious difference between the average energy depositions for a fixed complexity of SSB + BD determined by the number of base damage, but average energy depositions increase with the complexity of SSB + BD. In the complex clustered DNA damage constituted by the combination of DSBs and BD around them, a relatively simple type is a DSB combining adjacent BD, marked as DSB + BD, and it is of substantial contribution (on average up to about 82%). The spectrum of DSB + BD is given mainly by the DSB in combination with different numbers of base damage, from 1 to 5. For the considered primary energies, the DSB combined with only one base damage contributes about 83% of total DSB + BD, and the average energy deposition is about 106 eV. However, the

Life cycle primary energy use and carbon emission of an eight-storey wood-framed apartment building

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, Leif; Joelsson, Anna; Sathre, Roger [Ecotechnology, Department of Engineering and Sustainable Development, Mid Sweden University, 83125 Oestersund (Sweden)

2010-02-15

In this study the life cycle primary energy use and carbon dioxide (CO{sub 2}) emission of an eight-storey wood-framed apartment building are analyzed. All life cycle phases are included, including acquisition and processing of materials, on-site construction, building operation, demolition and materials disposal. The calculated primary energy use includes the entire energy system chains, and carbon flows are tracked including fossil fuel emissions, process emissions, carbon stocks in building materials, and avoided fossil emissions due to biofuel substitution. The results show that building operation uses the largest share of life cycle energy use, becoming increasingly dominant as the life span of the building increases. The type of heating system strongly influences the primary energy use and CO{sub 2} emission; a biomass-based system with cogeneration of district heat and electricity achieves low primary energy use and very low CO{sub 2} emissions. Using biomass residues from the wood products chain to substitute for fossil fuels significantly reduces net CO{sub 2} emission. Excluding household tap water and electricity, a negative life cycle net CO{sub 2} emission can be achieved due to the wood-based construction materials and biomass-based energy supply system. This study shows the importance of using a life cycle perspective when evaluating primary energy and climatic impacts of buildings. (author)

Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay.

Science.gov (United States)

An, F P; Balantekin, A B; Band, H R; Bishai, M; Blyth, S; Cao, D; Cao, G F; Cao, J; Chan, Y L; Chang, J F; Chang, Y; Chen, H S; Chen, Q Y; Chen, S M; Chen, Y X; Chen, Y; Cheng, J; Cheng, Z K; Cherwinka, J J; Chu, M C; Chukanov, A; Cummings, J P; Ding, Y Y; Diwan, M V; Dolgareva, M; Dove, J; Dwyer, D A; Edwards, W R; Gill, R; Gonchar, M; Gong, G H; Gong, H; Grassi, M; Gu, W Q; Guo, L; Guo, X H; Guo, Y H; Guo, Z; Hackenburg, R W; Hans, S; He, M; Heeger, K M; Heng, Y K; Higuera, A; Hsiung, Y B; Hu, B Z; Hu, T; Huang, E C; Huang, H X; Huang, X T; Huang, Y B; Huber, P; Huo, W; Hussain, G; Jaffe, D E; Jen, K L; Ji, X P; Ji, X L; Jiao, J B; Johnson, R A; Jones, D; Kang, L; Kettell, S H; Khan, A; Kohn, S; Kramer, M; Kwan, K K; Kwok, M W; Langford, T J; Lau, K; Lebanowski, L; Lee, J; Lee, J H C; Lei, R T; Leitner, R; Leung, J K C; Li, C; Li, D J; Li, F; Li, G S; Li, Q J; Li, S; Li, S C; Li, W D; Li, X N; Li, X Q; Li, Y F; Li, Z B; Liang, H; Lin, C J; Lin, G L; Lin, S; Lin, S K; Lin, Y-C; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, J L; Liu, J C; Loh, C W; Lu, C; Lu, H Q; Lu, J S; Luk, K B; Ma, X Y; Ma, X B; Ma, Y Q; Malyshkin, Y; Martinez Caicedo, D A; McDonald, K T; McKeown, R D; Mitchell, I; Nakajima, Y; Napolitano, J; Naumov, D; Naumova, E; Ngai, H Y; Ochoa-Ricoux, J P; Olshevskiy, A; Pan, H-R; Park, J; Patton, S; Pec, V; Peng, J C; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Qiu, R M; Raper, N; Ren, J; Rosero, R; Roskovec, B; Ruan, X C; Steiner, H; Stoler, P; Sun, J L; Tang, W; Taychenachev, D; Treskov, K; Tsang, K V; Tull, C E; Viaux, N; Viren, B; Vorobel, V; Wang, C H; Wang, M; Wang, N Y; Wang, R G; Wang, W; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Wei, H Y; Wen, L J; Whisnant, K; White, C G; Whitehead, L; Wise, T; Wong, H L H; Wong, S C F; Worcester, E; Wu, C-H; Wu, Q; Wu, W J; Xia, D M; Xia, J K; Xing, Z Z; Xu, J L; Xu, Y; Xue, T; Yang, C G; Yang, H; Yang, L; Yang, M S; Yang, M T; Yang, Y Z; Ye, M; Ye, Z; Yeh, M; Young, B L; Yu, Z Y; Zeng, S; Zhan, L; Zhang, C; Zhang, C C; Zhang, H H; Zhang, J W; Zhang, Q M; Zhang, R; Zhang, X T; Zhang, Y M; Zhang, Y X; Zhang, Y M; Zhang, Z J; Zhang, Z Y; Zhang, Z P; Zhao, J; Zhou, L; Zhuang, H L; Zou, J H

2017-06-23

The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW_{th} reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective ^{239}Pu fission fractions F_{239} from 0.25 to 0.35, Daya Bay measures an average IBD yield σ[over ¯]_{f} of (5.90±0.13)×10^{-43}  cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×10^{-43}  cm^{2}/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the ^{239}Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1σ. This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes ^{235}U, ^{239}Pu, ^{238}U, and ^{241}Pu. Based on measured IBD yield variations, yields of (6.17±0.17) and (4.27±0.26)×10^{-43}  cm^{2}/fission have been determined for the two dominant fission parent isotopes ^{235}U and ^{239}Pu. A 7.8% discrepancy between the observed and predicted ^{235}U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.

The energy spectrum of the 'runaway' electrons from a high voltage pulsed discharge

International Nuclear Information System (INIS)

Ruset, C.

1985-01-01

Some experimental results are presented on the influence of the pressure upon the energy spectrum of the runaway electrons generated into a pulsed high voltage argon discharge. These electrons enter a state of continuous acceleration between two collisions with rapidly increasing free path. The applied discharge current varies from 10 to 300 A, the pulse time is about 800 ns. Relativistic effects are taken into consideration. Theoretical explanation is based on the pnenomenon of electron spreading on plasma oscillations. (D.Gy.)

The Spectrum Sharing in Cognitive Radio Networks Based on Competitive Price Game

Directory of Open Access Journals (Sweden)

Y. B. Li

2012-09-01

Full Text Available The competitive price game model is used to analyze the spectrum sharing problem in the cognitive radio networks, and the spectrum sharing problem with the constraints of available spectrum resource from primary users is further discussed in this paper. The Rockafeller multiplier method is applied to deal with the constraints of available licensed spectrum resource, and the improved profits function is achieved, which can be used to measure the impact of shared spectrum price strategies on the system profit. However, in the competitive spectrum sharing problem of practical cognitive radio network, primary users have to determine price of the shared spectrum without the acknowledgement of the other primary user’s price strategies. Thus a fast gradient iterative calculation method of equilibrium price is proposed, only with acknowledgement of the price strategies of shared spectrum during last cycle. Through the adaptive iteration at the direction with largest gradient of improved profit function, the equilibrium price strategies can be achieved rapidly. It can also avoid the predefinition of adjustment factor according to the parameters of communication system in conventional linear iteration method. Simulation results show that the proposed competitive price spectrum sharing model can be applied in the cognitive radio networks with constraints of available licensed spectrum, and it has better convergence performance.

Enhanced primary and secondary performance through cognitive relaying and leveraging primary feedback

KAUST Repository

Hamza, Doha R.; Aï ssa, Sonia

2014-01-01

We consider a spectrum-sharing system, where the primary terminal operates in a time-slotted fashion and is active only when it has a packet to send. The secondary terminal uses spectrum sensing results and the primary automatic repeat request (ARQ) feedback to access the channel probabilistically. To enhance the primary's system performance, the secondary user (SU) acts as a relay for the primary user (PU) in the event of transmission failure on the direct link of the latter. Closed-form expressions for the primary and secondary throughputs are obtained for the described scheme. The optimal medium access probabilities are then obtained by maximizing the secondary throughput subject to constraints that guarantee the stability of the considered queues, a minimum primary throughput, and a maximum primary queueing delay. The results clearly indicate the benefits of cognitive relaying in enhancing the throughput performance for both the PU and SU. Furthermore, by guaranteeing minimum rate and maximum delay requirements, our scheme is shown to provide a definitive notion of protection for the licensed users of the network. © 2013 IEEE.

18 CFR 2.400 - Statement of interpretation of waste concerning natural gas as the primary energy source for...

Science.gov (United States)

2010-04-01

... interpretation of waste concerning natural gas as the primary energy source for qualifying small power production... concerning natural gas as the primary energy source for qualifying small power production facilities. For purposes of deciding whether natural gas may be considered as waste as the primary energy source pursuant...

Decision Analysis of Dynamic Spectrum Access Rules

Energy Technology Data Exchange (ETDEWEB)

Juan D. Deaton; Luiz A. DaSilva; Christian Wernz

2011-12-01

A current trend in spectrum regulation is to incorporate spectrum sharing through the design of spectrum access rules that support Dynamic Spectrum Access (DSA). This paper develops a decision-theoretic framework for regulators to assess the impacts of different decision rules on both primary and secondary operators. We analyze access rules based on sensing and exclusion areas, which in practice can be enforced through geolocation databases. Our results show that receiver-only sensing provides insufficient protection for primary and co-existing secondary users and overall low social welfare. On the other hand, using sensing information between the transmitter and receiver of a communication link, provides dramatic increases in system performance. The performance of using these link end points is relatively close to that of using many cooperative sensing nodes associated to the same access point and large link exclusion areas. These results are useful to regulators and network developers in understanding in developing rules for future DSA regulation.

Optimal Offering Strategies for Wind Power in Energy and Primary Reserve Markets

DEFF Research Database (Denmark)

Soares, Tiago; Pinson, Pierre; Jensen, Tue Vissing

2016-01-01

generation from the turbines. These offering strategies aim at maximizing expected revenues from both market floors using probabilistic forecasts for wind power generation, complemented with estimated regulation costs and penalties for failing to provide primary reserve. A set of numerical examples, as well......Wind power generation is to play an important role in supplying electric power demand, and will certainly impact the design of future energy and reserve markets. Operators of wind power plants will consequently develop adequate offering strategies, accounting for the market rules...... and the operational capabilities of the turbines, e.g., to participate in primary reserve markets. We consider two different offering strategies for joint participation of wind power in energy and primary reserve markets, based on the idea of proportional and constant splitting of potentially available power...

Reconstruction of extensive air showers and measurement of the cosmic ray energy spectrum in the range of 1 - 80 PeV at the South Pole

International Nuclear Information System (INIS)

Klepser, Stefan

2008-01-01

IceTop is a km 2 scale detector array for highly energetic cosmic radiation. It is a part of the IceCube Observatory that is presently being built at the geographic South Pole. It aims for the detection of huge particle cascades induced by PeV cosmic rays in the atmosphere. These extensive air showers are detected by cylindrical ice tanks that collect the Cherenkov light produced by penetrating particles. The main goal of IceTop is the investigation of the energy distribution and chemical composition of PeV to EeV cosmic rays. This thesis presents the first analysis of highly energetic cosmic ray data taken with IceTop. First, the light response of the IceTop tanks is parametrised as a function of energy and particle type. An expectation function for the distribution of shower signals in the detector plane is developed. The likelihood fit based on that can reconstruct the recorded shower events with resolutions of 1.5 in direction, 9m in location of the shower center, and 12% in energy. This is well competitive with other experiments. The resulting energy response of the array is studied to set up response matrices for different primary nuclei and inclinations. These allow for a deconvolution of the distribution of reconstructed energies to derive the real energy spectrum. Two unfolding algorithms are implemented and studied, and response matrices are modeled for four different composition assumptions. With each assumption, energy spectra are unfolded for three different bins in inclination, using a data sample with an exposure of 3.86.10 11 m 2 s sr, taken in August 2007. The range of the spectrum is 1-80 PeV. Finally, a new analysis method is developed that uses the fact that cosmic rays in the PeV range are expected to be isotropic. It is shown that this requirement can be used for a likelihood estimation that is sensitive to composition without using additional information from other detector components. The analysis shows a clear preference of the mixed

Reconstruction of extensive air showers and measurement of the cosmic ray energy spectrum in the range of 1 - 80 PeV at the South Pole

Energy Technology Data Exchange (ETDEWEB)

Klepser, Stefan

2008-06-24

IceTop is a km{sup 2} scale detector array for highly energetic cosmic radiation. It is a part of the IceCube Observatory that is presently being built at the geographic South Pole. It aims for the detection of huge particle cascades induced by PeV cosmic rays in the atmosphere. These extensive air showers are detected by cylindrical ice tanks that collect the Cherenkov light produced by penetrating particles. The main goal of IceTop is the investigation of the energy distribution and chemical composition of PeV to EeV cosmic rays. This thesis presents the first analysis of highly energetic cosmic ray data taken with IceTop. First, the light response of the IceTop tanks is parametrised as a function of energy and particle type. An expectation function for the distribution of shower signals in the detector plane is developed. The likelihood fit based on that can reconstruct the recorded shower events with resolutions of 1.5 in direction, 9m in location of the shower center, and 12% in energy. This is well competitive with other experiments. The resulting energy response of the array is studied to set up response matrices for different primary nuclei and inclinations. These allow for a deconvolution of the distribution of reconstructed energies to derive the real energy spectrum. Two unfolding algorithms are implemented and studied, and response matrices are modeled for four different composition assumptions. With each assumption, energy spectra are unfolded for three different bins in inclination, using a data sample with an exposure of 3.86.10{sup 11} m{sup 2} s sr, taken in August 2007. The range of the spectrum is 1-80 PeV. Finally, a new analysis method is developed that uses the fact that cosmic rays in the PeV range are expected to be isotropic. It is shown that this requirement can be used for a likelihood estimation that is sensitive to composition without using additional information from other detector components. The analysis shows a clear preference of

Kinetic energy spectrum and polarization of neutrons from the reaction 12C(p,n)X at 590 MeV

International Nuclear Information System (INIS)

Arnold, J.

1998-01-01

The kinetic energy spectrum and the polarization of the PSI neutron beam produced in the reaction 12 C(p,n)X at 0 with 590 MeV polarized protons were investigated. A strong energy dependence of the neutron beam polarization is observed which was not expected at the time the neutron beam was built. (orig.)

Development and Calibration of the ART-XC Mirror Modules for the Spectrum Rontgen Gamma Mission

Science.gov (United States)

Ramsey, B.; Gubarev, M.; Elsner, R.; Kolodziejczak, J.; Odell, S.; Swartz, D.; Pavlinsky, M.; Tkachenko, A.; Lapshov, I.

2013-01-01

The Spectrum-Röntgen-Gamma (SRG) mission is a Russian-lead X-ray astrophysical observatory that carries two co-aligned X-ray telescope systems. The primary instrument is the German-led extended ROentgen Survey with an Imaging Telescope Array (eROSITA), a 7-module X-ray telescope system that covers the energy range from 0.2-12 keV. The complementary instrument is the Astronomical Roentgen Telescope -- X-ray Concentrator (ART-XC or ART), a 7-module Xray telescope system that provides higher energy coverage, up to 30 keV.

Disaggregated seismic hazard and the elastic input energy spectrum: An approach to design earthquake selection

Science.gov (United States)

Chapman, Martin Colby

1998-12-01

The design earthquake selection problem is fundamentally probabilistic. Disaggregation of a probabilistic model of the seismic hazard offers a rational and objective approach that can identify the most likely earthquake scenario(s) contributing to hazard. An ensemble of time series can be selected on the basis of the modal earthquakes derived from the disaggregation. This gives a useful time-domain realization of the seismic hazard, to the extent that a single motion parameter captures the important time-domain characteristics. A possible limitation to this approach arises because most currently available motion prediction models for peak ground motion or oscillator response are essentially independent of duration, and modal events derived using the peak motions for the analysis may not represent the optimal characterization of the hazard. The elastic input energy spectrum is an alternative to the elastic response spectrum for these types of analyses. The input energy combines the elements of amplitude and duration into a single parameter description of the ground motion that can be readily incorporated into standard probabilistic seismic hazard analysis methodology. This use of the elastic input energy spectrum is examined. Regression analysis is performed using strong motion data from Western North America and consistent data processing procedures for both the absolute input energy equivalent velocity, (Vsbea), and the elastic pseudo-relative velocity response (PSV) in the frequency range 0.5 to 10 Hz. The results show that the two parameters can be successfully fit with identical functional forms. The dependence of Vsbea and PSV upon (NEHRP) site classification is virtually identical. The variance of Vsbea is uniformly less than that of PSV, indicating that Vsbea can be predicted with slightly less uncertainty as a function of magnitude, distance and site classification. The effects of site class are important at frequencies less than a few Hertz. The regression

High Energy Galactic Cosmic Rays Observed by RUNJOB Experiment

Energy Technology Data Exchange (ETDEWEB)

Hareyama, Makoto [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

2006-03-21

Galactic cosmic rays (GCRs) from proton to iron with the energy of 10{sup 13} - 10{sup 15} eV were observed by RUssia-Nippon JOint Balloon (RUNJOB) experiments. Each energy spectrum of the primary nuclear components except for helium is in agreement with the results obtained by other observations in the same energy region as the RUNJOB observation within statistical errors, while the intensity of the helium component is nearly half that obtained by the JACEE and the SOKOL observations. The spectrum slopes seem to be almost parallel or become gradually harder as mass becomes heavier. The power indices of the spectra are nearly -2.75 in the energy range of 20-500 TeV/nucleous. These our results support the acceleration mechanism and the propagation process in Galaxy of GCRs depend on its rigidity.

Effect of thermal mass on life cycle primary energy balances of a concrete- and a wood-frame building

International Nuclear Information System (INIS)

Dodoo, Ambrose; Gustavsson, Leif; Sathre, Roger

2012-01-01

Highlights: ► The effect of thermal mass on life cycle primary energy balance of concrete and wood building is analyzed. ► A concrete building has slightly lower space heating demand than a wood alternative. ► Still, a wood building has a lower life cycle primary energy use than a concrete alternative. ► The influence of thermal mass on space heating energy use for buildings in Nordic climate is small. -- Abstract: In this study we analyze the effect of thermal mass on space heating energy use and life cycle primary energy balances of a concrete- and a wood-frame building. The analysis includes primary energy use during the production, operation, and end-of-life phases. Based on hour-by-hour dynamic modeling of heat flows in building mass configurations we calculate the energy saving benefits of thermal mass during the operation phase of the buildings. Our results indicate that the energy savings due to thermal mass is small and varies with the climatic location and energy efficiency levels of the buildings. A concrete-frame building has slightly lower space heating demand than a wood-frame alternative, due to the higher thermal mass of concrete-based materials. Still, a wood-frame building has a lower life cycle primary energy balance than a concrete-frame alternative. This is due primarily to the lower production primary energy use and greater bioenergy recovery benefits of the wood-frame buildings. These advantages outweigh the energy saving benefits of thermal mass. We conclude that the influence of thermal mass on space heating energy use for buildings located in Nordic climate is small and that wood-frame buildings with cogeneration based district heating would be an effective means of reducing primary energy use in the built environment.

47 CFR 90.1407 - Spectrum use in the network.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Spectrum use in the network. 90.1407 Section 90... network. (a) Spectrum use. The Shared Wireless Broadband Network will operate using spectrum associated... from the primary public safety operations in the 763-768 MHz and 793-798 MHz bands. The network...

Computational uncertainties in silicon dioxide/plutonium intermediate neutron spectrum systems

International Nuclear Information System (INIS)

Jaegers, P.J.

1997-01-01

In the past several years, several proposals have been made for the long-term stabilization and storage of surplus fissile materials. Many of these proposed scenarios involve systems that have an intermediate neutron energy spectrum. Such intermediate-energy systems are dominated by scattering and fission events induced by neutrons ranging in energy from 1 eV to 100keV. To ensure adequate safety margins and cost effectiveness, it is necessary to have benchmark data for these intermediate-energy spectrum systems; however, a review of the nuclear criticality benchmarks indicates that no formal benchmarks are available. Nuclear data uncertainties have been reported for some types of intermediate-energy spectrum systems. Using a variety of Monte Carlo computer codes and cross-section sets, reported significant variations in the calculated k ∞ of intermediate-energy spectrum metal/ 235 U systems. We discuss the characteristics of intermediate neutron spectrum systems and some of the computational differences that can occur in calculating the k eff of these systems

Landau Quasi-energy Spectrum Destruction for an Electron in Both a Static Magnetic Field and a Resonant Electromagnetic Wave

International Nuclear Information System (INIS)

Skoblin, A.A.

1994-01-01

Free nonrelativistic electrons in both a static magnetic field and an electromagnetic wave are considered. A plane-polarized wave propagates along a magnetic field, its frequency is close to the electron rotation frequency in a magnetic field. Electron spin is taken into account. An electron quasi energy spectrum and steady states (quasi energy states) are constructed. 6 refs

The high energy X-ray spectrum of 4U 1700-37 observed from OSO 8

Science.gov (United States)

Dolan, J. F.; Coe, M. J.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.; Maurer, G. S.

1980-01-01

The most intense hard X-ray source in the confused region in Scorpius has been identified as 4U 1700-37 (=HD 153919). Observations extending over three binary periods in 1978 September were carried out with the high-energy X-ray spectrometer on OSO 8. The 3.4 day modulation is seen above 20 keV with the intensity during eclipse being consistent with zero flux. The photonumber spectrum from 20 to 150 keV is well represented by a single power law with a photonumber spectral index of -2.77 + or - 0.35 or by a thermal bremsstrahlung spectrum with kT = 27 (+15, -7)keV. The counting rate above 20 keV outside of eclipse shows no evidence for the 96.8 minute X-ray modulation previously reported at lower energies. Despite the difficulties that exist in reconciling both the lack of periodic modulation in the emitted X-radiation and the orbital dynamics of the system with our currently accepted theories of the evolution and physical properties of neutron stars, the observed properties of 4U 1700-37 are all consistent with the source being a spherically accreting neutron star rather than a black hole.

Detecting Energy Spectrum Of The Products Of Reaction 6Li(n,alpha)3H By The Home-Made Gaseous Detectors In Vietnam

International Nuclear Information System (INIS)

Luong Huu Phuoc; Phung Van Duan; Le Van Mien; Nguyen Tat Thang; Tran Hoai Nam

2008-01-01

There are shown some of results of study in designing and making first gaseous detectors of big sizes in Vietnam. The detectors were used for test measurement of detecting energy spectrum of the products of reaction 6 Li(n,alpha) 3 H caused by thermal neutrons. On the spectrum there were observed two energy peaks of tritons and alpha particles separately. In the test measurement there were used two neutron isotopic sources with total output 2x1.1x10 7 n/s. The study was implemented at Hanoi University of Technology. (author)

Spectrum and energy levels of nine-times ionized strontium [Sr X

International Nuclear Information System (INIS)

Acquista, N.; Reader, J.

1981-01-01

The spectrum of the copperlike ion Sr X was observed with a low-inductance spark in the region 70--630 A on the 10.7--m grazing-incidence spectrograph at the National Bureau of Standards. From the identification of 30 lines, a system of 23 energy levels of the type 3d 10 nl was determined. The level system includes the configurations ns (n = 4--7), np (n = 4--6), nd (n = 4--6), nf (n = 4--6), and ng (n = 5). The 4f 2 F term is inverted. Also identified were 12 transitions of the type 3d 10 4s--3d 9 4s4p and 3d 10 4p--3d 9 4p 2 , permitting the determination of several 3d 9 4s4p and 3d 9 4p 2 levels. The observed 3d 10 nl energy levels and parameters are compared with Hartree--Fock calculations. The ionization energy is determined from the 3d 10 ns and nf series to be 1 430 000 +- 500 cm -1 (177.30 +- 0.06 eV). Data for 3d--4p transitions in Sr IX and Sr XI and 3p--3d transitions in Sr XII are also presented

[Chromaticity and optical spectrum colorimetry of the tongue color in different syndromes of primary hepatic carcinoma].

Science.gov (United States)

Xu, Ying; Zeng, Chang-chun; Cai, Xiu-yu; Guo, Rong-ping; Nie, Guang; Jin, Ying

2012-11-01

In this study, the optical data of tongue color of different syndromes in primary hepatic carcinoma (PHC) were detected by optical spectrum colorimetry, and the chromaticity of tongue color was compared and analyzed. The tongue color characteristics of different syndromes in PHC and the relationship between different syndromes and tongue color were also investigated. Tongue color data from 133 eligible PHC patients were collected by optical spectrum colorimetry and the patients were divided into 4 syndrome groups according to their clinical features. The syndrome groups were liver depression and spleen deficiency (LDSD), accumulation of damp-heat (ADH), deficiency of liver and kidney yin (DLKY), and qi stagnation and blood stasis (QSBS). The variation characteristics of chromaticity coordinates, dominant wavelength, excitation purity and the distribution in the International Commission on Illumination (CIE) LAB uniform color space were measured. At the same time, the differences of overall chromatism, clarity, chroma, saturation and hue were also calculated and analyzed. PHC patients in different syndrome groups exhibited differences in chromaticity coordinates. The dominant wavelength of QSBS was distinctly different from that of the other 3 syndromes. Excitation purity in the syndromes of LDSD, ADH and DLKY showed gradual increases (Pcolorimetry technology. Different syndromes in PHC exhibit distinct chromatisms of tongue color through the calculation and analysis of chromaticity parameters of CIE, combined with colorimetric system and CIE LAB color space, and these are consistent with the characteristics of clinical tongue color. Applying optical spectrum colorimetry technology to tongue color differentiation has the potential to serve as a reference point in standardizing traditional Chinese medicine syndrome classification in PHC.

Measurement of the internal bremsstrahlung spectrum of a 89Sr beta emitter in the 1–100 keV photon energy regime

International Nuclear Information System (INIS)

Singh, Amrit; Dhaliwal, A.S.

2015-01-01

The internal bremsstrahlung (IB) spectrum of 89 Sr, which is a unique first forbidden beta emitter, is studied in the 1–100 keV photon energy regime. The IB spectrum is experimentally measured using a Si(Li) detector, which is efficient in this photon energy regime, and is compared with the IB distributions that are predicted by the Knipp, Uhlenbeck and Bloch (KUB), Nilsson, and Lewis and Ford theories. In the soft energy regime up to 15 keV, the measured results are in agreement with all the aforementioned theories. However, from 16–30 keV, the experimental results are in agreement with the Lewis and Ford theory, which applies to forbidden transitions, and at higher photon energies, the Nilsson theory best describes the measured results. The differences among the different theories also increase with the photon energy. The effect of the electrostatic Coulomb field on the IB process for beta emitters with different end-point energies is investigated by comparing the ratio of the IB probabilities predicted using the KUB and Nilsson theories for 35 S and 89 Sr, i.e., soft and hard beta emitters, respectively. The Coulomb effect is shown to be significant in the high photon energy regime and for beta emitters with low end-point energies. - Highlights: • Internal bremsstrahlung spectrum of 89 Sr, a unique first forbidden beta emitter, is studied. • The measurements are taken in the photon energy regions of 1–100 keV with Si(Li) detector. • The measured results are deviating from Lewis and Ford theory and are close to the Nilsson theory. • The effect of Coulomb field on the IB process for different end point energy sources is investigated. • Effect of Coulomb field is more for low energy beta emitter towards the high energy end

Market-driven spectrum sharing in cognitive radio

CERN Document Server

Yi, Changyan

2016-01-01

This brief focuses on the current research on mechanism design for dynamic spectrum sharing in cognitive radio (CR) networks. Along with a review of CR architectures and characteristics, this brief presents the motivations, significances and unique challenges of implementing algorithmic mechanism design for encouraging both primary spectrum owners and secondary spectrum users to participate in dynamic spectrum sharing. The brief then focuses on recent advances in mechanism design in CR networks. With an emphasis on dealing with the uncertain spectrum availabilities, mechanisms based on spectrum recall, two-stage spectrum sharing and online spectrum allocation are introduced with the support of theoretic analyses and numerical illustrations. The brief concludes with a discussion of potential research directions and interests, which will motivate further studies on mechanism design for wireless communications. This brief is concise and approachable for researchers, professionals and advanced-level students in w...

Calculating the energy spectrum of neutrons from tritium target of the NG-150 type generator

International Nuclear Information System (INIS)

Bortash, A.I.; Kuznetsov, V.S.

1987-01-01

Calculation procedure of neutron spectra yielding from the NG-150 generator target chamber with regard to deutron moderation is suggested. Using the suggested procedure, neutron spectra for different escape angles formed in the tritium target are calculated. The spectrum of neutrons scattered in cooling water is calculated. The mean energy of neutrons escaping at the angle of 0 deg equalling 14.5 MeV is obtained

Energy spectrum scaling in an agent-based model for bacterial turbulence

Science.gov (United States)

Mikel-Stites, Maxwell; Staples, Anne

2017-11-01

Numerous models have been developed to examine the behavior of dense bacterial swarms and to explore the visually striking phenomena of bacterial turbulence. Most models directly impose fluid dynamics physics, either by modeling the active matter as a fluid or by including interactions between the bacteria and a fluid. In this work, however, the `turbulence' is solely an emergent property of the collective behavior of the bacterial population, rather than a consequence of imposed fluid dynamics physical modeling. The system is simulated using a two dimensional Vicsek-style model, with the addition of individual repulsion to simulate bacterial collisions and physical interactions, and without the common flocking or sensing behaviors. Initial results indicate the presence of k-1 scaling in a portion of the kinetic energy spectrum that can be considered analogous to the inertial subrange in turbulent energy spectra. This result suggests that the interaction of large numbers of individual active bacteria may also be a contributing factor in the emergence of fluid dynamics phenomena, in addition to the physical interactions between bacteria and their fluid environment.

X-ray Lβ215 emission spectrum of Ru in Ru(NH3)6Cl3

International Nuclear Information System (INIS)

Perera, R.C.C.; Barth, J.; LaVilla, R.E.; Nordling, C.

1984-07-01

One of the broader applications of synchrotron radiation has been to EXAFS studies for material structure determination, i.e., for an analysis of x-ray absorption over an extended energy region beyond a core ionization limit. Studies of the near edge structure (XANES) give a different type of information, characteristic of the local symmetry and electronic configuration of the absorbing atom. This type of information is reflected also in the x-ray emission spectra, in particular for transitions involving the valence levels. Examination of the near edge absorption or the emission spectrum does not require an instrument capable of scanning a wide energy range with high counting statistics, as does EXAFS; the needs are rather for good resolution and a reliable calibration of the energy scale. Some of the problems of near edge spectra were particularly evident in our investigation of Ru-Lβ 2 15 emission from Ru(NH 3 ) 6 Cl 3 . The Ru-Lβ 2 15 emission was measured with a laboratory Rowland circle x-ray spectrometer with a curved quartz (1010) crystal (radius = 22 inches) in a fixed position appropriate to the energy range, and a position sensitive detector which can be positioned along the Rowland circle. The Ru spectrum was excited mainly by Sn-L/sub α/ primary radiation from a Sn anode in a demountable x-ray tube operating at 13 kV and 120 mA. The resolution of the instrument in this region is 1.5 eV. An accurate calibration of the energy scale was conveniently obtained by measuring a reference x-ray emission line in the same instrumental configuration. In the present case the Pd-L/sub α/ emission line at 2838 eV was used to establish the energy scale. The energy dispersion of the instrument was determined from the Cl-K/sub β/ emission spectrum of CH 3 Cl between 2810 eV and 2830 eV and Pd-Lα 1 2 and extrapolated to the energy region of the recorded emission spectrum. 6 references, 1 figure

Collective behaviour of linear perturbation waves observed through the energy density spectrum

Energy Technology Data Exchange (ETDEWEB)

Scarsoglio, S [Department of Water Engineering, Politecnico di Torino (Italy); De Santi, F; Tordella, D, E-mail: stefania.scarsoglio@polito.it [Department of Aeronautics and Space Engineering, Politecnico di Torino (Italy)

2011-12-22

We consider the collective behaviour of small three-dimensional transient perturbations in sheared flows. In particular, we observe their varied life history through the temporal evolution of the amplification factor. The spectrum of wave vectors considered fills the range from the size of the external flow scale to the size of the very short dissipative waves. We observe that the amplification factor distribution is scale-invariant. In the condition we analyze, the system is subject to all the physical processes included in the linearized Navier-Stokes equations. With the exception of the nonlinear interaction, these features are the same as those characterizing the turbulent state. The linearized perturbative system offers a great variety of different transient behaviours associated to the parameter combination present in the initial conditions. For the energy spectrum computed by freezing each wave at the instant where its asymptotic condition is met, we ask whether this system is able to show a power-law scaling analogous to the Kolmogorov argument. At the moment, for at least two typical shear flows, the bluff-body wake and the plane Poiseuille flow, the answer is yes.

Going nuclear. Some implications of the introduction of nuclear energy as the basic primary energy supply of a developped society

International Nuclear Information System (INIS)

Haefele, W.; Sassin, W.

1975-01-01

On the basis of nuclear energy as primary energy source, the future development potentialities of secondary energies are considered; these energy forms are coal gaseification, process heat for industrial uses and district heating, and mainly hydrogen production which represents 60% of the future secondary energy demands. By using decision tree method, the eventuality of using nuclear energy as unique energy source is examined, and the successive options implied in this approach are analyzed [fr

Measurement of the Cosmic-Ray Antiproton Spectrum at Solar Minimum with a Long-Duration Balloon Flight over Antarctica

Science.gov (United States)

Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Kim, K. C.; Kusumoto, A.; Lee, M. H.; Makida, Y.;

Prompt neutron spectrum of the spontaneous fission of californium-252

International Nuclear Information System (INIS)

Zamyatnin, Yu.S.; Kroshkin, N.I.; Korostylev, V.A.; Nefedov, V.N.; Ryazanov, D.K.; Starostov, B.I.; Semenov, A.F.

1976-01-01

The californium-252 spontaneous fission neutron spectrum was measured in the energy range of 0.01 to 10 MeV by the time-of-flight technique using various neutron detectors. The measurements of 252 Cf neutron spectrum at energies of 0.01 to 5 MeV were performed as a function of fission fragment kinetic energy. The mean neutron spectrum energy in the range of 0.7 to 10 MeV was found from the results of measurements. The irregularity in the 252 Cf neutron spectrum in the neutron energy range of less than 0.7 MeV compared to theoretical values is discussed. The mechanism of 252 Cf neutron emission is also discussed on the basis of neutron yield angle measurements. 12 references

Spectrum Handoffs Based on Preemptive Repeat Priority Queue in Cognitive Radio Networks

Directory of Open Access Journals (Sweden)

Xiaolong Yang

2016-07-01

Full Text Available Cognitive radio can significantly improve the spectrum efficiency, and spectrum handoff is considered as an important functionality to guarantee the quality of service (QoS of primary users (PUs and the continuity of data transmission of secondary users (SUs. In this paper, we propose an analytical framework based on a preemptive repeat identical (PRI M/G/1 queuing network model to characterize spectrum handoff behaviors with general service time distribution of both primary and secondary connections, multiple interruptions and transmission delay resulting from the appearance of primary connections. Then, we derive the close-expression of the extended data delivery and the system sojourn time in both staying and changing scenarios. In addition, based on analysis of spectrum handoff behaviors resulting from multiple interruptions caused by the appearance of the primary connections, we investigate the traffic-adaptive policy, by which the considered SU will optimally adjust its handoff spectrum policy. Moreover, we investigate the admissible region and provide the reference for designing the admission control rule for the arriving secondary connection requests. Finally, simulation results verify that our proposed analytical framework is reasonable and can provide the reference for executing the optimal spectrum handoff strategy and designing the admission control rule for the SU in cognitive radio networks.

Effect of updated WIMSD libraries on neutron energy spectrum at irradiation site of Pakistan Research Reactor-1 using 3D modeling

International Nuclear Information System (INIS)

Ahmad, Siraj-ul-Islam; Ahmad, Nasir

2005-01-01

International Atomic Energy Agency (IAEA) has recently released new WIMSD libraries based on current cross-section evaluations. Using these libraries the effect of different evaluated data sets on effective multiplication factor and neutron energy spectrum was studied with the help of 3D reactor simulation code CITATION. Simulation methodology adopted in this work was validated by analyzing IAEA 10 MW benchmark reactor. The k eff values obtained using all newly released libraries are within 0.45% to the experimental value, while the old library released in 1981 resulted in calculated value 1.05% larger than experimental. The flux spectrum obtained for standard fuel element using 3D modeling is smaller in fast energy range and higher in thermal energy range than is calculated using the 1D model for the standard cell. In the flux trap, differences of about -4% to 13% were found in thermal flux using the newly released libraries as compared to that obtained using 1981 WIMSD library. The major differences in the flux spectra between newly available libraries and the 1981 WIMSD library in thermal energy range are due to the differences in cross-sections of hydrogen bound-in-water. The use of only newly available cross-sections of hydrogen bound-in-water with 1981 WIMSD library resulted in significant improvement in value of k eff as well as in the flux spectrum. Moreover the differences among new libraries in the thermal energy range are also due to these cross-sections. Difference in fission spectra from different libraries is responsible for differences of flux spectra in the fast energy range. These differences in flux are reduced significantly in the fast energy range by only replacement of fission spectra

Interference-aware random beam selection for spectrum sharing systems

KAUST Repository

Abdallah, Mohamed M.

2012-09-01

Spectrum sharing systems have been introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this paper, we develop interference-aware random beam selection schemes that provide enhanced throughput for the secondary link under the condition that the interference observed at the primary link is within a predetermined acceptable value. For a secondary transmitter equipped with multiple antennas, our schemes select a random beam, among a set of power- optimized orthogonal random beams, that maximizes the capacity of the secondary link while satisfying the interference constraint at the primary receiver for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the signal-to-noise and interference ratio (SINR) statistics as well as the capacity of the secondary link. Finally, we present numerical results that study the effect of system parameters including number of beams and the maximum transmission power on the capacity of the secondary link attained using the proposed schemes. © 2012 IEEE.

Comparison of biomolecule desorption yields for low and high energy primary ions

International Nuclear Information System (INIS)

Kamensky, I.; Hakansson, P.; Sundqvist, B.; McNeal, C.J.; MacFarlane, R.

1982-01-01

Ion induced desorption yields of molecular ions from samples of cesium iodide, glycylglycine, ergosterol, bleomycin and a trinucleoside diphosphate have been studied using primary beams of 54 MeV 63 Cu 9+ and 3 keV 133 Cs + . Mass analysis was performed with a time-of-flight technique. Each sample was studied with the same spectrometer for both low and high energy primary ions and without opening of the vacuum chamber in between the measurements. The results show that fast heavy ions give larger yields for all samples studied and that the yield ratios for high to low energy desorption increase with the mass of the sample molecule. (orig.)

Comparative analysis of primary versus relapse/refractory DLBCL identifies shifts in mutation spectrum.

Science.gov (United States)

Greenawalt, Danielle M; Liang, Winnie S; Saif, Sakina; Johnson, Justin; Todorov, Petar; Dulak, Austin; Enriquez, Daniel; Halperin, Rebecca; Ahmed, Ambar; Saveliev, Vladislav; Carpten, John; Craig, David; Barrett, J Carl; Dougherty, Brian; Zinda, Michael; Fawell, Stephen; Dry, Jonathan R; Byth, Kate

2017-11-21

Current understanding of the mutation spectrum of relapsed/refractory (RR) tumors is limited. We performed whole exome sequencing (WES) on 47 diffuse large B cell lymphoma (DLBCL) tumors that persisted after R-CHOP treatment, 8 matched to primary biopsies. We compared genomic alterations from the RR cohort against two treatment-naïve DLBCL cohorts (n=112). While the overall number and types of mutations did not differ significantly, we identified frequency changes in DLBCL driver genes. The overall frequency of MYD88 mutant samples increased (12% to 19%), but we noted a decrease in p.L265P (8% to 4%) and increase in p.S219C mutations (2% to 6%). CARD11 p.D230N, PIM1 p.K115N and CD79B p.Y196C mutations were not observed in the RR cohort, although these mutations were prominent in the primary DLBCL samples. We observed an increase in BCL2 mutations (21% to 38% of samples), BCL2 amplifications (3% to 6% of samples) and CREBBP mutations (31% to 42% of samples) in the RR cohort, supported by acquisition of mutations in these genes in relapsed compared to diagnostic biopsies from the same patient. These increases may reflect the genetic characteristics of R-CHOP RR tumors expected to be enriched for during clinical trial enrollment. These findings hold significance for a number of emerging targeted therapies aligned to genetic targets and biomarkers in DLBCL, reinforcing the importance of time-of-treatment biomarker screening during DLBCL therapy selection.

A wavelet-based Gaussian method for energy dispersive X-ray fluorescence spectrum

Directory of Open Access Journals (Sweden)

Pan Liu

2017-05-01

Full Text Available This paper presents a wavelet-based Gaussian method (WGM for the peak intensity estimation of energy dispersive X-ray fluorescence (EDXRF. The relationship between the parameters of Gaussian curve and the wavelet coefficients of Gaussian peak point is firstly established based on the Mexican hat wavelet. It is found that the Gaussian parameters can be accurately calculated by any two wavelet coefficients at the peak point which has to be known. This fact leads to a local Gaussian estimation method for spectral peaks, which estimates the Gaussian parameters based on the detail wavelet coefficients of Gaussian peak point. The proposed method is tested via simulated and measured spectra from an energy X-ray spectrometer, and compared with some existing methods. The results prove that the proposed method can directly estimate the peak intensity of EDXRF free from the background information, and also effectively distinguish overlap peaks in EDXRF spectrum.

Possible connection between the location of the cutoff in the cosmic microwave background spectrum and the equation of state of dark energy.

Science.gov (United States)

Enqvist, Kari; Sloth, Martin S

2004-11-26

We investigate a possible connection between the suppression of the power at low multipoles in the cosmic microwave background (CMB) spectrum and the late time acceleration. We show that, assuming a cosmic IR/UV duality between the UV cutoff and a global infrared cutoff given by the size of the future event horizon, the equation of state of the dark energy can be related to the apparent cutoff in the CMB spectrum. The present limits on the equation of state of dark energy are shown to imply an IR cutoff in the CMB multipole interval of 9>l>8.5.

MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO{sup +}(H{sub 2}O) cluster using accurate potential energy and dipole moment surfaces

Energy Technology Data Exchange (ETDEWEB)

Homayoon, Zahra, E-mail: zhomayo@emory.edu [Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

2014-09-28

A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO{sup +}(H{sub 2}O) cluster is reported. The PES is based on fitting of roughly 32 000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO{sup +}(H{sub 2}O) and NO{sup +}(D{sub 2}O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO{sup +}(H{sub 2}O) and NO{sup +}(D{sub 2}O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO{sup +}(H{sub 2}O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good agreement with experiment. Mode coupling of the water “antisymmetric” stretching mode with the low-frequency intermolecular modes results in intensity borrowing.

Electron bremsstrahlung spectrum, 1--500 keV

International Nuclear Information System (INIS)

Lee, C.M.; Kissel, L.; Pratt, R.H.; Tseng, H.K.

1976-01-01

Numerical data are obtained for the electron bremsstrahlung energy spectrum resulting from incident electrons of kinetic energy 1--500 keV, under the assumption that the process is described as a single-electron transition in a relativistic self-consistent screened potential, using partial-wave expansions. Comparisons with simpler analytical approximations show that these are at best of qualitative validity in this energy range. Our data are used to construct more complete tables of the spectrum by interpolation

Primary power supply of repetitive pulsed intense current accelerator charged by capacitance of energy store

International Nuclear Information System (INIS)

Chen Jun; Yang Jianhua; Shu Ting; Zhang Jiande; Zhou Xiang; Wen Jianchun

2008-01-01

The primary power supply of repetitive pulsed intense current accelerator charged by capacitance of energy store is studied. The principle of primary power supply circuit and its time diagram of switches are presented. The circuit is analyzed and some expressions are got, especially, the usable voltage scope of capacitance of energy store, and the correlation between the parameters of circuit and time delay, which is between the turn-on of the charging circuit of capacitance of energy store and the circuit of recuperation. The time delay of 256 x 256 lookup table is made with the instruction of theory and the simulation of the actual parameters of circuits. The table is used by the control program to control the repetitive operating of the actual pulsed intense current accelerator. Finally, some conclusions of the primary power supply of repetitive pulsed intense current accelerator charged by capacitance of energy store are got. (authors)

Carbon Capture Methods and Relative Competitiveness of Primary Energies

International Nuclear Information System (INIS)

Amigues, Jean-Pierre; Lafforgue, Gilles; Moreaux, Michel

2016-01-01

We characterise the optimal exploitation paths of two primary energies (coal and solar) that supply the energy needs of two sectors. Sector 1 can reduce its carbon emissions at a reasonable cost thanks to a CCS device. Sector 2 has access only to air capture technology, but at a significantly higher cost. We assume that the atmospheric carbon stock cannot exceed a given ceiling. We show that the optimal approach consists in, first, fully capturing sector-1 emissions before the ceiling is reached and, second, deploying air capture to partially abate sector-2 emissions. The optimal carbon tax should increase in the pre-ceiling phase then decline in stages to zero

Monte-Carlo simulation of primary electrons in the matter for the generation of x-rays

International Nuclear Information System (INIS)

Bendjama, H.; Laib, Y.; Allag, A.; Drai, R.

2006-01-01

The x-rays imagining chains components from the source to the detector, rest on the first part of simulation to the energy production of x-rays emission (source), which suggest us to identified the losses energies result from interaction between the fast electrons and the particles of metal : the energies losses due to 'collisional losses' (ionization, excitation) and radiative losses. For the medium and the primary electron energy which interests us, the electrons slowing down in the matter results primarily from the inelastic collisions; whose interest is to have to simulate the x-rays characteristic spectrum. We used a Monte-Carlo method to simulate the energy loss and the transport of primary electrons. This type of method requires only the knowledge of the cross sections attached to the description of all the elementary events. In this work, we adopted the differential cross section of Mott and the total cross section of inner-shell ionization according to the formulation of Gryzinski, to simulate the energy loss and the transport of primary electrons respectively. The simulation allows to follow the electrons until their energy reaches the atomic ionization potential of the irradiated matter. The differential cross section of Mott gives us a very good representation of the pace of the distribution of the energy losses. The transport of primary electron is approximately reproduced

Primary hyperoxaluria: spectrum of clinical and imaging findings

Energy Technology Data Exchange (ETDEWEB)

Strauss, Sara B.; Levin, Terry L. [Children' s Hospital of Montefiore Medical Center, Division of Pediatric Radiology, Department of Radiology, Bronx, NY (United States); Waltuch, Temima; Kaskel, Frederick [Children' s Hospital at Montefiore Medical Center, Division of Pediatric Nephrology, Bronx, NY (United States); Bivin, William [Allegheny General Hospital, Department of Pathology, Pittsburgh, PA (United States)

2017-01-15

Primary hyperoxaluria is a rare autosomal recessive inborn error of metabolism with three known subtypes. In primary hyperoxaluria type 1, the most common of the subtypes, a deficiency in the hepatic enzymes responsible for the metabolism of glycoxylate to glycine, leads to excessive levels of glyoxylate, which is converted to oxalate. The resultant elevation in serum and urinary oxalate that characterizes primary hyperoxaluria leads to calcium oxalate crystal deposition in multiple organ systems (oxalosis). We review the genetics, pathogenesis, variable clinical presentation and course of this disease as well as its treatment. Emphasis is placed on the characteristic imaging findings before and after definitive treatment with combined liver and renal transplantation. (orig.)

Off-axis holographic lens spectrum-splitting photovoltaic system for direct and diffuse solar energy conversion.

Science.gov (United States)

Vorndran, Shelby D; Chrysler, Benjamin; Wheelwright, Brian; Angel, Roger; Holman, Zachary; Kostuk, Raymond

2016-09-20

This paper describes a high-efficiency, spectrum-splitting photovoltaic module that uses an off-axis volume holographic lens to focus and disperse incident solar illumination to a rectangular shaped high-bandgap indium gallium phosphide cell surrounded by strips of silicon cells. The holographic lens design allows efficient collection of both direct and diffuse illumination to maximize energy yield. We modeled the volume diffraction characteristics using rigorous coupled-wave analysis, and simulated system performance using nonsequential ray tracing and PV cell data from the literature. Under AM 1.5 illumination conditions the simulated module obtained a 30.6% conversion efficiency. This efficiency is a 19.7% relative improvement compared to the more efficient cell in the system (silicon). The module was also simulated under a typical meteorological year of direct and diffuse irradiance in Tucson, Arizona, and Seattle, Washington. Compared to a flat panel silicon module, the holographic spectrum splitting module obtained a relative improvement in energy yield of 17.1% in Tucson and 14.0% in Seattle. An experimental proof-of-concept volume holographic lens was also fabricated in dichromated gelatin to verify the main characteristics of the system. The lens obtained an average first-order diffraction efficiency of 85.4% across the aperture at 532 nm.

Theoretical models for the muon spectrum at sea level

International Nuclear Information System (INIS)

Abdel-Monem, M.S.; Benbrook, J.R.; Osborne, A.R.; Sheldon, W.R.

1975-01-01

The absolute vertical cosmic ray muon spectrum is investigated theoretically. Models of high energy interactions (namely, Maeda-Cantrell (MC), Constant Energy (CE), Cocconi-Koester-Perkins (CKP) and Scaling Models) are used to calculate the spectrum of cosmic ray muons at sea level. A comparison is made between the measured spectrum and that predicted from each of the four theoretical models. It is concluded that the recently available measured muon differential intensities agree with the scaling model for energies less than 100 GeV and with the CKP model for energies greater than 200 GeV. The measured differential intensities (Abdel-Monem et al.) agree with scaling. (orig.) [de

Declining primary energy consumption in nine countries of the European Community in 1980

International Nuclear Information System (INIS)

Gabel, R.

1981-01-01

The Statistical Office of the European Communities has published preliminary figures for energy consumption in the Community (of the Nine) for the year 1980. These show a primary energy consumption for the EEC in 1980 of approx. 1344 mtce. That is 63 mtce or 4.5% less than in the previous year. Primary energy consumption in 1980 still bore comparison, to some extent, with the previous record figures for 1973, the last 'normal year' before the first crisis. The figures for all the Community countries show that the energy policy measures introduced in recent years are becoming more effective, particularly the attempts to restrict oil consumption. There is also the effect of oil prices, which again rose dramatically in 1979/80. Whether this decline in consumption will continue in the future will only become clear when the promised economic upturn arrives. (orig./UA) [de

Cosmic ray spectrum, composition, and anisotropy measured with IceCube

International Nuclear Information System (INIS)

Tamburro, Alessio

2014-01-01

Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the “knee” region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of penetrating muons and other particles. Surface and in-ice signals detected in coincidence provide clear insights into the nuclear composition of cosmic rays. IceCube already measured an increase of the average primary mass as a function of energy. We present preliminary results on both IceTop-only and coincident events analysis. Furthermore, we review the recent measurement of the cosmic ray anisotropy with IceCube

Cosmic ray spectrum, composition, and anisotropy measured with IceCube

Science.gov (United States)

Tamburro, Alessio

2014-04-01

Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the "knee" region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of penetrating muons and other particles. Surface and in-ice signals detected in coincidence provide clear insights into the nuclear composition of cosmic rays. IceCube already measured an increase of the average primary mass as a function of energy. We present preliminary results on both IceTop-only and coincident events analysis. Furthermore, we review the recent measurement of the cosmic ray anisotropy with IceCube.

Energy conservation in the primary aluminum and chlor-alkali industries

Energy Technology Data Exchange (ETDEWEB)

1980-10-01

The primary aluminum and chlor-alkali industries together use nearly 13% of the electrical energy consumed by US industry. As part of its mission to promote energy conservation in basic US industries, the DOE surveys the present technological status of the major electrochemical industries and evaluates promising technological innovations that may lead to reduced energy requirements. This study provides technical and economic analyses in support of a government program of research and development in advanced electrolytic technology. This program is intended to supplement the development efforts directed toward energy savings by private industry. Sections II and III of this report cover aluminum and chlorine production processes only, since these two industries represent over 90% of the electrical energy requirements of all electrolytic industries in the United States. Section IV examines barriers to accelerated research and development by the electrolytic industries, and makes suggestions for government actions to overcome these barriers.

The Analysis of Closed-form Solution for Energy Detector Dynamic Threshold Adaptation in Cognitive Radio

Directory of Open Access Journals (Sweden)

R. Bozovic

2017-12-01

Full Text Available Spectrum sensing is the most important process in cognitive radio in order to ensure interference avoidance to primary users. For optimal performance of cognitive radio, it is substantial to monitor and promptly react to dynamic changes in its operating environment. In this paper, energy detector based spectrum sensing is considered. Under the assumption that detected signal can be modelled according to an autoregressive model, noise variance is estimated from that noisy signal, as well as primary user signal power. A closed-form solution for optimal decision threshold in dynamic electromagnetic environment is proposed and analyzed.

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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.

Determination of neutron energy spectrum at a pneumatic rabbit station of a typical swimming pool type material test research reactor

International Nuclear Information System (INIS)

Malkawi, S.R.; Ahmad, N.

2002-01-01

The method of multiple foil activation was used to measure the neutron energy spectrum, experimentally, at a rabbit station of Pakistan Research Reactor-1 (PARR-1), which is a typical swimming pool type material test research reactor. The computer codes MSITER and SANDBP were used to adjust the spectrum. The pre-information required by the adjustment codes was obtained by modelling the core and its surroundings in three-dimensions by using the one dimensional transport theory code WIMS-D/4 and the multidimensional finite difference diffusion theory code CITATION. The input spectrum covariance information required by MSITER code was also calculated from the CITATION output. A comparison between calculated and adjusted spectra shows a good agreement

Primary defect production by high energy displacement cascades in molybdenum

Energy Technology Data Exchange (ETDEWEB)

Selby, Aaron P. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Xu, Donghua, E-mail: xudh@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Juslin, Niklas; Capps, Nathan A. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Oak Ridge National Laboratory, P.O. Box 2008, MS6003, Oak Ridge, TN 37831 (United States)

2013-06-15

We report molecular dynamics simulations of primary damage in molybdenum produced by high energy displacement cascades on the femto- to pico-second and Angstrom to nanometer scales. Clustering directly occurred for both interstitials and vacancies in the 1–50 keV cascade energy range explored. Point defect survival efficiency and partitioning probabilities into different sized clusters were quantified. The results will provide an important reference for kinetic models to describe the microstructural evolution in Mo under ion or neutron irradiations over much longer time and length scales.