Energy Technology Data Exchange (ETDEWEB)

The first meeting on e{gamma}/{gamma}{gamma} colliders was held on September 28 and 29, 1993, at the National Laboratory for High Energy Physics. After general remarks were delivered, lectures were given on QED in intense laser field, photon linear collider, laser focusing, luminosity distribution in the e{gamma}/{gamma}{gamma} colliders, QCD correction for {gamma}{gamma}{yields}H, radiation correction for e{gamma}/{nu}W process, SUSY particle production at the e{gamma} and {gamma} gamma colliders, formation of e{sup *} in e{gamma} collision, and general remarks on the theory. Discussion was carried out on `Where are we going from here?` In this book, the gists of the lectures are collected. (K.I.).

UK PubMed Central (United Kingdom)

AbstractThis study investigated the distribution of bovine spongiform encephalopathy (BSE) in herds of cattle in Ireland over the years 1996 through 2000, prior to the introduction of...Full Text Available

CERN Document Server

We consider the effect of distributed delays in neural feedback systems. The avian optic tectum is reciprocally connected with the nucleus isthmi. Extracellular stimulation combined with intracellular recordings reveal a range of signal delays from 4 to 9 ms between isthmotectal elements. This observation together with prior mathematical analysis concerning the influence of a delay distribution on system dynamics raises the question whether a broad delay distribution can impact the dynamics of neural feedback loops. For a system of reciprocally connected model neurons, we found that distributed delays enhance system stability in the following sense. With increased distribution of delays, the system converges faster to a fixed point and converges slower toward a limit cycle. Further, the introduction of distributed delays leads to an ...

Energy Technology Data Exchange (ETDEWEB)

We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in {gamma}{gamma}{yields}t t-bar {yields}lX/bX for various beam polarizations in order to study possible anomalous t t-bar {gamma}, tbW and {gamma}{gamma}H couplings, which could be generated by SU(2) x U(1) gauge-invariant dimension-6 effective operators. We find optimal beam polarizations that will minimize the uncertainty in determination of those non-standard couplings. We also compare e e-bar and {gamma}{gamma} colliders from the viewpoint of the anomalous-top-quark-coupling determination.

Energy Technology Data Exchange (ETDEWEB)

The proton beam has an advantage of the sharp dose falloff in dose distribution called Bragg peak while conventional radiation therapy modalities such as photons exhibit considerable amount of exit dose. To take advantage of this property it is important to know the exact location of the distal dose falloff. An error can cause overdose to the normal tissue or underdose to the tumor volume. The only way of finding out the dose distribution in-situ in particle therapy is to measure the gammas produced by nuclear reactions with tissue materials. Two kinds of gammas can be used: one is prompt gamma and the other is coincident gamma from the positron-emission isotopes. We chose to detect prompt gammas, and developed a prompt gamma scanning system (PGS). The proton beams of the proton therapy facility at National Cancer Center ...

International Nuclear Information System (INIS)

Most general tbW couplings were investigated in the process #gamma##gamma# #-># tt-bar #-># l"#+-#X for unpolarized photon beams. The double angular and energy distribution of the lepton was calculated and an optimal-observable analysis on it was carried out for the SM tt-bar production mechanism. It was also shown that the leptonic angular distribution is insensitive to non-standard tbW vertex. That means that observation of non-standard effects indicates existence of some new physics in the production part.

Energy Technology Data Exchange (ETDEWEB)

A future e{sup -}-e{sup +} (electron-positron) linear collider can be configured with perhaps minimal modification to serve as an {gamma}-{gamma} (gamma-gamma) or a e{sup -}-{gamma} collider. This is accomplished by Compton-backscattering low energy photons (from a laser source) off of the high-energy electron beams prior to the crossing of the electron beams. However, to be competitive with the e{sup -}-e{sup +} configuration, the luminosity cannot be compromised in the process. This requires that the laser source deliver a sufficient number of photons per pulse with a pulse format and rate matching that of the electron beams. As it turns out, this requires an average optical power of 5-15 kW from the laser which is beyond the current state of the art. In this paper, we address how to generate the required pulse format and how the high average power requirement can be met with conventional laser ...

CERN Document Server

We investigate the effect of anomalous gamma-W-W couplings in e-gamma --> nu W through the angular and energy spectrum of the secondary leptons. Within the narrow-width approximation, a semi-analytical study of the secondary lepton energy-angle double distribution is considered. Utility of observables derived from this is demonstrated by considering the anomalous coupling, delta-kappa-gamma. Results of our investigation for typical ILC machine considered at Ecm = 300-1000 GeV re-affirms potential of this collider as a precision machine.

Energy Technology Data Exchange (ETDEWEB)

Measurements of {gamma}-ray, {gamma}{gamma}-coincidence and internal conversion electron spectra from the {sup 106}Cd({alpha},n{gamma}){sup 109}Sn reaction were carried out at 15-20 MeV {alpha}-particle bombarding energies with Ge(HP) {gamma}-ray and superconducting magnetic lens plus Si(Li) electron spectrometers. The energies, relative intensities, internal conversion coefficients and coincidence relations of the {sup 109}Sn transitions were determined, and a more complete, consistent level scheme has been deduced. Spin and parity values have been determined from the internal conversion coefficients, the bombarding-energy dependence of the side-feeding intensities of the states and the available {gamma}-ray angular distribution data. The level scheme was interpreted in the framework of the quasi-particle shell model.

International Nuclear Information System (INIS)

Treatment with gamma and electron radiation is becoming a common process for the sterilization of packages, mostly made of natural or synthetic plastics, used in the aseptic processing of foods and pharmaceuticals. The effect of irradiation on these materials is crucial for packaging engineering to understand the effects of these new treatments. Packaging material may be irradiated either prior to or after filling. The irradiation prior to filling is usually chosen for dairy products, processed food, beverages, pharmaceutical, and medical device industries in the United States, Europe, and Canada. Radiation effects on packaging material properties still need further investigation. This paper summarizes the work done by different groups and discusses recent developments in regulations and testing procedures in the field of packaging technology.

Energy Technology Data Exchange (ETDEWEB)

We have constructed a Monte Carlo generator (the corresponding FORTRAN code can be obtained from the authors upon request) for lowest-order predictions for the processes {gamma}{gamma}{yields}4f and {gamma}{gamma}{yields}4f{gamma} in the standard model and extensions thereof by an effective {gamma}{gamma}H coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes {gamma}{gamma}{yields}4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic beam spectrum on cross sections and distributions is illustrated. ...

Energy Technology Data Exchange (ETDEWEB)

Diffuse {gamma}-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse {gamma}-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse {gamma}-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30{sup o} and 110{sup o} and between 136{sup o} and 216{sup o} and for Galactic latitudes between -10{sup o} and 10{sup o} are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the ...

International Nuclear Information System (INIS)

The O(#alpha#) electroweak radiative corrections to #gamma##gamma##->#WW#->#4f within the electroweak standard model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into factorizable and non-factorizable contributions, and real-photonic corrections are based on complete lowest-order matrix elements for #gamma##gamma##->#4f+#gamma#. Soft and collinear singularities appearing in the virtual and real corrections are combined alternatively in two different ways, namely by using the dipole subtraction method or by applying phase-space slicing. The radiative corrections are implemented in a Monte Carlo generator called Coffer #gamma##gamma# - the computer code can be obtained from the authors upon request - which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over ...

Energy Technology Data Exchange (ETDEWEB)

Neutron and gamma ray energy spectra were measured using an NE-213 scintillator at depths of 7.2, 15.2, and 22.2 cm in a tissue-equivalent phantom which was uniformly irradiated on one face by deuterium--tritium (DT) neutrons. Coupled neutron--gamma ray multigroup discrete-ordinates calculations were performed using semi-infinite slab geometry. These calculations were used to supplement the measured spectra below 1 MeV. Similar calculations were performed to study the perturbation in the phantom due to the detector. The measured and calculated spectra were used to determine the kerma distributions for neutrons and gamma rays at each location. The gamma radiation was determined to contribute more than 10% of the total dose at each depth. The calculated kerma also reveals that a knowledge of the gamma ray spectra below 1 MeV is desirable. Key words: ...

Energy Technology Data Exchange (ETDEWEB)

Resistance of Alloy 800 as a PWR S/G tube material to IGC/IGSCC and Ni, Co release into water was evaluated as compared with Alloys 600 and 690. The study to improve the resistance to IGSCC and general corrosion was also made, including the effects of shot-peening on the distribution of the residual stress of the U-bent tubes and the susceptibility to SCC, the stabilizing elements on IGC/IGSCC, and prior oxidation on general corrosion. From the results, shot-peened Alloy 800 was estimated to be the most reliable S/G tube material among the high nickel alloys tested. In addition, the Alloy 800 tube would obtain further reliability in IGSCC and general corrosion resistance by the combined addition of Ti, and Nb, and the prior oxidation of the inner tube surface, respectively.

International Nuclear Information System (INIS)

Ferrite of system, namely Ni_1_-_xZn_xFe_2O_4 with x = (0.0, 0.2, 0.4, 0.6, 0.8, 1.0), have been prepared by solid state reaction to investigate the effect of gamma rays irradiations using Co"6"0 source on the cation distribution, structural and magnetic properties. The unirradiated and irradiated samples were then subjected to characterization techniques such as X-ray diffraction, magnetization and AC susceptibility. The results of these characterizations are found to be different for irradiated from that of the pristine sample. The modifications in respect of irradiated samples are explained in terms of the ion-induced disorder. The important result of #gamma#-irradiation on the cation distribution, structural and magnetic properties is the change of ratio Fe"2"+/Fe"3"+. Possible reasons on the results are proposed.

Energy Technology Data Exchange (ETDEWEB)

Measurements of neutron and gamma-ray penetrations in an iron shield were performed up to a 60-cm depth in a tightly coupled source shield configuration with the fast-neutron reactor YAYOI as a source. Rates of neutron reactions and gamma-ray dose rates in the iron shield were obtained using activation foils and thermoluminescent dosimeters. Analyses of the experiments were made by using the DOT-III code with coupled neutron and gamma-ray cross sections from ENDF/B-IV and POPOP4 libraries. To obtain the source condition for the iron shield analyses, the calculated spectrum was adjusted to the measured reaction rates at the reactor shield boundary. The calculated neutron and gamma-ray distributions in the iron shield show fairly good agreement with the experiments. The effect of difference in Bondarenko-type self-shielding factors on the analyses of the iron shield is also shown.

International Nuclear Information System (INIS)

The next-to-leading-order (NLO) cross section for the production of heavy quarks at large transverse momenta #gamma##gamma# collision is calculated with perturbative fragmentation functions (PFF). This approach allows for a resummation of terms #propor to# #alpha#_sln(p"2/m"2) which arise in NLO from collinear emission of gluons by a heavy quark at large p or from almost collinear branching of photons or gluons into heavy-quark pairs. It is presented single-inclusive distributions in p and rapidity including direct and resolved photons for #gamma##gamma# production of heavy quarks at e"+e"-colliders and at high-energy #gamma##gamma# colliders. The results are compared with fixed- order calculation for m finite including QDC radiative corrections. The two approaches differ in the definitions and relative contributions of the direct and resolved terms, but essentially agree in their sum. The resummation ...

International Nuclear Information System (INIS)

A method of using gamma radiation to determine the density and phase distribution in two-phase flows in pipes is described. Three collimated beams of radiation that pass through a pipe cross-section at different radial positions are used. A theory and computer program used to relate the measured attenuation of these beams to a three-parameter model of the phase distribution and to the average density and void fraction are discussed. Data obtained during both static and dynamic verification experiments using Lucite inserts are presented, as well as the results of several tests done in high pressure, steam-water flows.

International Nuclear Information System (INIS)

The distribution of mass, charge and angular momentum transfer among the products of 54-Fe (255 MeV) ions collisions with the 106 Cd target have been studied. The energy level schemes for 92-Mo, 60-Ni, 96-Ru and 56-Fe are presented. The production yields of different isotopes were also measured. 1 ref., 14 figs.

Energy Technology Data Exchange (ETDEWEB)

In the investigations reported here, a helium-jet/tape-transport system was used for the rapid transfer of fission products to a low-background environment where their aggregate beta and gamma-ray spectra were measured as a function of delay time after neutron induced fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Beta and gamma-ray energy distributions have been deduced for delay times as short as 0.2 s and extending out to 100,000s. Instrumentation development during the initial phase of the project included: (1) assembly and characterization of a NaI(Tl) spectrometer for determining aggregate gamma-ray energy distributions, (2) development and characterization of a beta spectrometer (having excellent gamma-ray rejection) for measuring aggregate beta-particle energy distributions, (3) assembly and characterization of a ...

Energy Technology Data Exchange (ETDEWEB)

Short communication.

International Nuclear Information System (INIS)

Short communication.

Energy Technology Data Exchange (ETDEWEB)

The macroscopic stress distribution across an annealed Zircaloy-4 gas tungsten arc weld was measured by neutron time-of-flight diffraction at the SMARTS diffractometer at Los Alamos National Laboratory. The stresses after annealing are about 40% lower than those in the same weld prior to heat treatment. The intergranular strains in the reference coupons, which give the macroscopic stress free lattice spacings, are consistent with the difference in cooling the strongly textured plate and the weakly textured weld.

CERN Document Server

The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after the burst, indicative of a jet break. The timing of the jet break combined with the total gamma-ray energy of the burst constrains the opening angle of the jet to be 2.5 degrees. We derive an empirical `time-lag' redshift from the BAT data of z_hat = 0.69 +/- 0.02, in good agreement with the spectroscopic redshift of 0.61. Prior to the jet break, the X-ray data can be modelled by a simple power law with index alpha = -1.2. However after 300s the X-ray flux brightens by about 30% compared to the power-law fit. The optical/UV data have a more complex decay, with evidence of a rapidly falling reverse shock component that dominates in the first minute or so, ...

International Nuclear Information System (INIS)

Several configurations of moderating and shielding materials have been designed and measured on the LVR-15 reactor for boron neutron capture therapy (BNCT) purposes. To determine the neutron and gamma ray space-energy distributions in the cylindrical geometry, the two-dimensional code DOT with the coupled neutron-gamma data library DLC-36 was used. The experimental verification of the beam parameters was performed in the LVR-15 reactor thermal column empty space with layers of graphite, aluminium, alumina, lead and bismuth. Attention was paid to establishing techniques and instrumentation for monitoring the neutron and gamma ray dose and beam quality. The thermal and epithermal flux densities were measured by activation foils, the neutron spectrum was determined with a Bonner spectrometer and gamma ray background with a scintillation spectrometer. The ...

International Nuclear Information System (INIS)

The alpha particle induced fission of "2"0"9Bi has been investigated for E_#alpha# = 55.7 and 58.6 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The mass distributions have been found to be broad with a peak near mass 104. The charge distribution has been studied at the same particle energies. The fractional cumulative yields of "9"7Zr, "9"9Mo, "1"0"1Mo, "1"1"2Pd and "1"1"7"mCd have been determined using gamma ray spectrometry. The width of charge distribution is broad. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Mass distribution in 28.5 MeV alpha particle induced fission of {sup 232}Th has been determined using gamma spectrometric technique. The chain yields of 24 different fission products covering both symmetric and asymmetric mass divisions were determined. The mass distribution was found to be asymmetric with peak positions at mass numbers 96 and 136 respectively while the peak to valley ratio was 3.86. The results are compared with the available literature on 14 MeV neutron induced fission of {sup 235}U. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The detection efficiency of gamma scanning system in irradiated materials examination facility has been measured. Gamma-ray sources used in this experiment are Cs-Co standard sources a PWR spent fuel rod in which {sup 134}Cs and {sup 154}Eu peaks are clearly identified in the energy region of 500 to 1,600 keV. The distance between source and detector is about 1.6 m. A slit type collimator with 3 mm-width window and 30 mm-thick lead block are installed between source and detector. The detector is a HPGe detector. This equipment is mainly used in gamma scanning of irradiated nuclear fuel. The measured detection efficiency seems to be 1.89 x 10{sup -6} % for 1 MeV gamma-ray. With these results the activities of unknown sources could be measured. This results are expected to be used in the measurement of the absolute distribution of gamma emitting nuclides in ...

Energy Technology Data Exchange (ETDEWEB)

The relationship between the fractal dimensions of spatial distributions of aftershocks and pre-existing active faults is examined. Fourteen mainshocks taking place in Japan were followed by aftershocks, and the aftershocks occur in swarms around the mainshocks. The epicentral distributions of the aftershocks exhibit fractal properties, and the fractal dimensions are estimated by using the two-point correlation integral. The pre-existing active fault systems observed in the 14 aftershock regions have fractal structures, and the fractal dimensions are estimated by using the box-counting method. A positive correlation between the estimated fractal dimensions is found, and it is independent on the mainshock magnitude. The correlation shows that aftershock distributions become less clustered with increasing the fractal dimensions of active fault systems. Namely, the fractal clusters of aftershocks are put under the constraint ...

International Nuclear Information System (INIS)

Low-lying nuclear energy levels in "1"1"0In and "1"1"2In were determined from de-excitation #gamma#-rays produced with "1"0"7Ag(#alpha#,n#gamma#)-"1"1"0In, "1"0"8Pd("6Li,4n#gamma#)"1"1"0In, "1"0"9Ag(#alpha#,n#gamma#)"1"1"2In and "1"1"0Pd("6Li,4n#gamma#)"1"1"2In reactions. In addition, the "1"1"4In energy level structure was investigated with the "1"1"0Pd("7Li,3n#gamma#)"1"1"4In reaction. Properties of de-excitation #gamma#-rays were determined from #gamma#-#gamma# coincidence, excitation, and angular distribution measurements conducted with Ge(Li) and Ge(intr.) #gamma#-ray detectors. A sequence of intraconnected levels in each of "1"1"0,"1"1"2,"1"1"4In were assigned to the (#pi#g"-"1/sub 9/2/, #nu#h/sub 11/2/) configuration. For the "1"1"0,"1"1"2,"1"1"4In energy level schemes a ...

International Nuclear Information System (INIS)

This work improves the reliability and accuracy in the reconstruction of the total isotope activity content in heterogeneous nuclear waste drums containing point sources. The method is based on #chi#"2-fits of the angular dependent count rate distribution measured during a drum rotation in segmented gamma scanning. A new description of the analytical calculation of the angular count rate distribution is introduced based on a more precise model of the collimated detector. The new description is validated and compared to the old description using MCNP5 simulations of angular dependent count rate distributions of Co-60 and Cs-137 point sources. It is shown that the new model describes the angular dependent count rate distribution significantly more accurate compared to the old model. Hence, the reconstruction of the activity is more accurate and the errors are considerably reduced that ...

Energy Technology Data Exchange (ETDEWEB)

Using {gamma}-irradiation-induced reduction in the field of a {sup 60}Co {gamma}-ray source, colloidal silver and gold nanoparticles were prepared from their corresponding metal salts in aqueous solution and compared with those by chemical reduction. The radiation-based method provided silver nanoparticles with higher concentration and narrower size distribution than those obtained by chemical reduction method while there was no significant difference between the two strategies for the preparation of gold nanoparticles. {gamma}-Irradiation of 1.0 x 10{sup -3} M AgNO{sub 3} solution resulted in nearly 100 times more highly concentrated silver colloids than those by citrate reduction. Furthermore, the radiation method could lead to more highly concentrated silver colloids by simply increasing the concentration of AgNO{sub 3} solution up to 2.0 x 10{sup -2} M. The two metal nanoparticles prepared by the ...

International Nuclear Information System (INIS)

US Department of Energy methods used for characterization of contact-handled transuranic (CH-TRU) waste prior to shipment to the Waste Isolation Pilot Plant (WIPP) are described and listed by contractor site. The methods described are part of the certification process. All CH-TRU waste must be assayed for determination of fissile material content and decay heat values prior to shipment and prior to storage on-site. Both nondestructive assay (NDA) and destructive assay methods are discussed, and new NDA developments such as passive-action neutron (PAN) crate counter improvements and neutron imaging are detailed. Specifically addressed are assay method physics; applicability to CH-TRU wastes; calibration standards and implementation; operator training requirements and practices; assay procedures; assay precision, bias, and limit of detection; and assay limitation. While PAN is a new technique and does not yet have established ...

Energy Technology Data Exchange (ETDEWEB)

In the present thesis, the shell structure in exotic nuclei has been investigated. The focus of the work was on finding new experimental data in neutron-rich Cr and proton-rich Ca isotopes. The investigation of light Ca isotopes concentrated on the nucleus {sup 36}Ca which was produced in a knockout reaction from a radioactive {sup 37}Ca beam. For {sup 36}Ca, the excitation energy of the first 2{sup +} state has been measured for the first time. Furthermore, momentum distributions were analyzed using a Monte-Carlo simulation of the knockout reaction. This analysis yielded the contributions of neutrons from individual orbitals to the total knockout cross section. In principle, these may be used to calculate spectroscopic factors, but such a calculation is hampered by difficulties of present knockout-reaction models in predicting precise single-particle cross sections. The measured branching ratio to the ground and excited states, on the other hand, is close to the ...

Energy Technology Data Exchange (ETDEWEB)

We apply and modify the computer codes CAIN(P.Chen, G.Horton-Smith, T.Ohgaki, A.W.Weidemann, K.Yokoya, contributed to Workshop on Gamma-Gamma Colliders, Berkeley, CA, March 28-31, 1994; SLAC-PUB-6583.) and GUINEAPIG(D.Schulte (DESY), unpublished.) to make detailed studies of the beam-beam interaction in the SLAC design for a future linear collider (NLC), as well as to the proposed SLC2000 project. Using realistic beam distributions, we present simulations related to the tuning and optimization of luminosity in SLC2000 and NLC.

Energy Technology Data Exchange (ETDEWEB)

A 52-year-old woman had a history of left hearing loss for 5 years. An acoustic neurinoma with 3.2 cm in diameter was diagnosed and treated with gamma-knife radiosurgery (19 Gy of marginal dose) 1 year and 4 months ago. She developed headache, nausea, and visual disturbance 1 month prior to admission. Slight left facial palsy appeared after radiosurgery. Magnetic resonance imaging demonstrated the tumor with central necrosis in the left cerebellopontine angle cistern, increasing in size to 3.5 cm in diameter, and hydrocephalus. Tumor removal was performed incompletely, because of the fibrous appearance of the tumor and severe adherence with the surrounding cerebellar tissue. Facial palsy did not worsen after surgery. Since the hydrocephalus was not resolved, a right ventriculo-peritoneal shunt was inserted. The clinical course in this case suggests that tumor removal followed by radiosurgery was an approximately effective treatment for large ...

International Nuclear Information System (INIS)

The dependence of the efficiency of a coaxial IGC-30 Ge detector on the direction of gamma quanta entry, their energy and the distance from the source is examined. A set of point sources QCR-2 (Amersham, UK) has been used which is arranged consecutively in two perpendicular planes passing through the detector axis, at a distance of 0.1 - 1.3 m (pace 0.1) from its geometric centre for 16 different angles in every plane. Dependence curves of the efficiency on the angle of gamma-quanta hits are obtained for energies 60, 81, 122, 356, 662, 834, 1173 and 1332 keV. Changes in efficiency connected with spatial dividing ability are found out. Using the least squares' method the expected spatial distribution of efficiency is examined with a level of authenticity P > 0.9. The possible causes for the efficiency change and its possible effect on the measurements' precision are discussed. (author).

Energy Technology Data Exchange (ETDEWEB)

A spectroscopic study is performed for high spin states of {sup 55}Fe, {sup 55}Co and {sup 57}Ni. To populate the investigated residues with a relevant cross section, the fusion evaporation reactions of {sup 30}Si({sup 28}Si, 2pn){sup 55}Fe, {sup 30}Si({sup 28}Si, 2pn){sup 55}Co and {sup 4}He({sup 54}Fe, n){sup 57}Ni were chosen. To identify the new {gamma} transitions and to build the energy level schemes, {gamma}-{gamma} coincidence techniques together with excitation functions were employed. Angular distributions and {gamma}-{gamma} angular correlations allowed us to assign the spin values of the nuclear states. The previous level scheme of {sup 55}Fe is extended into the region between 6.5-11 MeV of excitation energy, up to spin 27/2, while the yrast decay pathos of {sup 57}Ni and {sup 55}Co are reported here for the first time. Experimental data are fairly well reproduced by Glaudemans' ...

International Nuclear Information System (INIS)

A simulated hull monitoring system based on passive #gamma# ray scanning was set-up in K-01 hot-cell, which consists of a simulated hull basket, a collimator system, a 150 cm"3 HPGe detector and an ORTEC-919 multichannel buffer-computer system. Six different kinds of experimental set-up were established to simulate the variations of #gamma# ray source term distribution (partly concentration) and the variations of matrix density (+46.1%). The experimental results show that the biases of peak area is better than -25.3% for "1"3"7Cs 662 keV #gamma# rays and -18.6% for "1"4"4Ce-"1"4"4Pr 2186 keV #gamma# rays. The hardness of pulse height spectrum is demonstrated to show that the peak area ratio of 2186 keV to 662 keV varies from 380 to 72 when the thickness of lead filter varies form 5 mm to 30 mm. Also studied are the design parameters of collimator system.

Energy Technology Data Exchange (ETDEWEB)

Globular clusters are quite compact (size {proportional_to}10 pc) objects distributed spherically around the galaxy. They contain about 10{sup 5}-10{sup 6} mostly old stars. The number of millisecond pulsars in typical globular cluster is expected to be large (of the order of 100). We investigate the possible mechanism of production of high energy gamma-rays in those objects. Part of the wind energy of pulsars (energy conversion factor) is converted into relativistic leptons. Those leptons can upscatter in inverse Compton process low energy starlight and CMB photons and produce gamma-rays. MAGIC is an Imaging Atmospheric Cerenkov Telescopes located at Canary island of La Palma. We present results and discussion of the MAGIC observations of globular cluster M13.

Energy Technology Data Exchange (ETDEWEB)

Gamma scanning measurements are used to determine the radioactive nuclides from an irradiated fuel rod in a hot cell which is a routine task in the Irradiated Materials Examination Facility (IMEF) of the Korea Atomic Energy Research Institute (KAERI), Total gamma spectra of radioactive nuclides and the atomic ratio of {sup 134}Cs to {sup 137}Cs in a few segments of a single fuel rod are measured by the present gamma scanning system. For the purpose of determining the radioactive nuclide's distribution in detail within a fuel rod quantitatively, we attempt to upgrade the present gamma scanning system in this paper, therefore, an investigation of the feasibility of the tomographic gamma scanning (TGS) technique, which is one of the promising nondestructive assay (NDA) methods is proposed. The TGS technique is an efficient method and it has an accurate ...

CERN Document Server

This book examines the applications of Monte Carlo (MC) calculations in therapeutic nuclear medicine, from basic principles to computer implementations of software packages and their applications in radiation dosimetry and treatment planning. It is written for nuclear medicine physicists and physicians as well as radiation oncologists, and can serve as a supplementary text for medical imaging, radiation dosimetry and nuclear engineering graduate courses in science, medical and engineering faculties. With chapters is written by recognised authorities in that particular field, the book covers the entire range of MC applications in therapeutic medical and health physics, from its use in imaging prior to therapy to dose distribution modelling targeted radiotherapy. The contributions discuss the fundamental concepts of radiation dosimetry, radiobiological aspects of targeted radionuclide therapy and the various components and steps required for ...

Energy Technology Data Exchange (ETDEWEB)

RESRAD was one of the multimedia models selected by the US Nuclear Regulatory Commission (NRC) to include in its workshop on radiation dose modeling and demonstration of compliance with the radiological criteria for license termination. This paper is a summary of the presentation made at the workshop and focuses on the 10 questions the NRC distributed to all participants prior to the workshop. The code selection criteria, which were solicited by the NRC, for demonstrating compliance with the license termination rule are also included. Among the RESRAD family of codes, RESRAD and RESRAD-BUILD are designed for evaluating radiological contamination in soils and in buildings. Many documents have been published to support the use of these codes. This paper focuses on these two codes. The pathways considered, the databases and parameters used, quality control and quality assurance, benchmarking, verification and validation of these codes, and ...

Energy Technology Data Exchange (ETDEWEB)

This document deals with the couplings between the W boson and Z and gamma particles. WWZ and WW{gamma} vertex are predicted by the electroweak theory based on the symmetry group SU(2){sub L}*U(1){sub Y}, their existence is confirmed by the measurement of the production cross-section of W pairs at LEP. The effective values of the couplings are modified by the introduction of standard model particle loops at the vertex level, the impact on the coupling value is assessed to reach 10{sup -3}. These loops can also include beyond-the-standard-model particles, their impact is in the magnitude order of 10{sup -3} for most models. The fully description of these loops requires the values of 14 complex parameters whose measurement will give information about the existence of new particles. Nevertheless the number of events at LEP is not sufficient to measure all the parameters simultaneously. As a consequence the analysis is limited to the 3 most ...

International Nuclear Information System (INIS)

Data of thermally stimulated luminescence (TSL) of single (Cu), double (Cu, Mn) and triple (Cu, Mn, Gd) activated SrS phosphors, which throws light on the nature and distribution of deeper traps have been presented. The samples are prepared by Bhawalkar's method and excited by UV 365 nm and #gamma#-rays to study the phenomenon. (author). 8 refs., 2 figs., 1 tab.

International Nuclear Information System (INIS)

We studied the solvent extraction behavior of astatine and found the anomalous behavior of this element similar to radioiodine. Astatine was extracted into CS_2 from acidic solution over a wide range of carrier iodine concentration. The distribution ratios of astatine were determined by measuring the #gamma#-ray from 210 At with a NaI(Tl) detector. A drastic change was observed around at 10"-"4 mol/l as in the case of 131 l. This tendency is well explained by the kinematics of the chemical reactions concerned. (author).

DEFF Research Database (Denmark)

The recently observed X-ray synchrotron emission from four supernova remnants (SNRs) has strengthened the evidence that cosmic-ray electrons are accelerated in SNRs. We show that if this is indeed the case, the local electron spectrum will be strongly time-dependent, at least above roughly 30 GeV. The time dependence stems from the Poisson fluctuations in the number of SNRs within a certain volume and within a certain time interval. As far as cosmic-ray electrons are concerned, the Galaxy looks like actively bubbling Swiss cheese rather than a steady, homogeneously filled system. Our finding has important consequences for studies of the Galactic diffuse gamma-ray emission, for which a strong excess over model predictions above 1 GeV has recently been reported. While these models relied on an electron injection spectrum with index 2.4 (chosen to fit the local electron flux up to 1 TeV), we show that an electron injection index of around 2.0 would (1) be consistent ...

International Nuclear Information System (INIS)

Short communication.

CERN Document Server

$\\gamma/\\phi_3$ at hadron colliders

British Library Electronic Table of Contents (United Kingdom)

To improve the performance of voice activity detector (VAD) in noisy environments, this paper concentrates on three critical aspects related to noise robustness including speech features, feature distributions and temporal dependence. Based on the statistic on TIMIT and NOIZEUS, Mel-frequency cepstrum coefficients (MFCCs) are selected as speech features, Gaussian Mixture distributions (GMD) are applied to associate the observations in MFCC domain with both speech and non-speech states, and Weibull and Gamma distributions are used to explicitly model noise and speech durations, respectively. To integrate these aspects into VAD, the hidden semi-Markov model (HSMM) as a generalized hidden Markov model (HMM) is introduced first. Then the VAD decision is made according to the likelihood ratio t...

International Nuclear Information System (INIS)

The emission of #alpha# particles in coincidence with the most deeply inelastic heavy-ion reactions has been studied for "1"8"1Ta + "1"6"5Ho at 1354 MeV laboratory energy and /sup nat/Ag + "8"4Kr at 664 MeV. #alpha# particle energy spectra and angular distributions, in coincidence with a projectile-like fragment, were acquired both in the reaction plane and out of the reaction plane at a fixed in-plane angle. The in-plane data for both systems are employed to show that the bulk of the #alpha# particles in coincidence with the deep-inelastic exit channel can be explained by evaporation from the fully accelerated fragments. Average velocity diagrams, #alpha#-particle energy spectra as a function of angle in several rest frames, and #alpha#-particle angular distributions are presented. The out-of-plane #alpha# particle angular distributions and the #gamma#-ray multiplicities are used to study the transfer ...

International Nuclear Information System (INIS)

I have analyzed reduced neutron widths (#GAMMA#_n"0) for the subset of 1245 resonances in the nuclear data ensemble (NDE) for which they have been reported. Random matrix theory (RMT) predicts for the Gaussian orthogonal ensemble (GOE) that these widths should follow a #chi#"2 distribution having one degree of freedom (#nu# = 1) - the Porter Thomas (PT) distribution. Using the maximum-likelihood (ML) technique, I have determined that the #GAMMA#_n"0 values in the NDE are best described by a #chi#"2 distribution having #nu# =0.801 #+-# 0.052, which is 3.8 standard deviations smaller than predicted by RMT. I show that this striking disagreement is most likely due to the inclusion of significant p-wave contamination to the supposedly pure s-wave NDE. Furthermore, when an energy-dependent threshold is used to remove the p-wave contamination, ML analysis yields #nu# = 1.217 #+-# 0.092 ...

International Nuclear Information System (INIS)

Oxygen-16 induced fission studies of "2"0"9Bi have been carried out at particle energies of 89.5 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The yield distribution of fission products has been found to be broad (FWHM #approx =# mass units) with a peak near mass #approx =# 108. The charge distribution in the "1"6O ion induced fission of "2"0"9Bi has also been studied at particle energy of 89.5 MeV. The relative cumulative yields of "9"2Sr, "9"7Zr, "9"9Mo, "1"0"1Mo, "1"1"2Pd and "1"1"7"mCd have been determined using gamma ray spectrometry. The width of charge distribution has been found to be broad. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Biomonitoring of human populations for exposure to genotoxic/clastogenic agents in the environment or the workplace must depend upon statistical tests for elevations in the frequencies of the biological endpoints being monitored, usually chromosomal aberrations (CA), micronuclei (MN), or sister chromatid exchanges (SCE) in peripheral blood lymphocytes. Statistical tests are based, in turn, upon certain assumptions regarding the distribution of the test statistic. When they are often not recognized as such, tests of significance can be in error, and any conclusion drawn that there is or is not a statistically significant difference between one population sample and another maybe erroneous. In population monitoring this means either false negatives or false positives can result and it is hard to know which is worse. Furthermore, even the intelligent design of studies whose object is to test for an elevated level in an exposed population must depend upon ...

Energy Technology Data Exchange (ETDEWEB)

A study was carried out to determine optimum decontamination dose for a locally manufactured coconut cream powder. Samples were gamma irradiated (0-15 kGy) and ageing process was achieved using GEER oven at 60 deg. C for 7 days, which is equivalent to one-year storage at room temperature. Iodine value (IV), ranging from 4.8 to 6.4, was not affected by radiation doses and storage, however peroxide value and thiobarbituric acid (TBA) generally increased with radiation doses. In most samples, peroxide value (meq/kg) reduced after storage, whilst the TBA (mg malonaldehyde/kg), indicator for product quality, slightly increased. The sensory evaluation conducted using 25 taste panellists indicated that scores on odour, creamy taste and overall acceptance for all irradiated samples at more than 5 kGy were significantly lower (P<0.05) than the control. However, the panellists could not detect any significant differences among the irradiation doses (P>0.05). ...

Energy Technology Data Exchange (ETDEWEB)

The production of three vector bosons in {gamma} {gamma} collisions studying the reactions {gamma} + {gamma} {yields} W{sup +} + W{sup -} + Z{sup 0} and {gamma} + {gamma} {yields} W{sup +} + W{sup -} + {gamma}. 12 refs., 4 figs., 2 tabs.

International Nuclear Information System (INIS)

The authors present tensile data and creep-rupture data out to approximately 40,000 h duration on low-carbon Alloy 800. Each of the four casts was heat treated to three conditions in tube form. When the test programme was originally conceived, the prime object was to obtain 100,000 hour design data; the programme was designed prior to some of the more recently discovered effects such as that of #gamma#' on ductility. Therefore no specific attempt was made to control to a low level, the Al and Ti contents of the casts. A subsequent programme was embarked upon in 1976 where these factors were taken into account. The bulk data obtained show many characteristics which are probably typical of the low-carbon variant of this material and both the quantity and duration of the data are a contribution to the knowledge of the long-term behaviour of this class of alloy, whose future use lies, inter alia, in nuclear applications over the temperature range ...

Wastenet

as a by-product during the purification of molten magnesium chloride prior to its electrolysis and during the

Energy Technology Data Exchange (ETDEWEB)

We studied the effects of small, <20 {micro}m, Te inclusions on the energy resolution of CdZnTe gamma-ray detectors using a highly collimated X-ray beam and gamma-rays, and modeled them via a simplified geometrical approach. Previous reports demonstrated that Te inclusions of about a few microns in diameter degraded the charge-transport properties and uniformity of CdZnTe detectors. The goal of this work was to understand the extent to which randomly distributed Te-rich inclusions affect the energy resolution of CZT detectors, and to define new steps to overcome their deleterious effects. We used a phenomenological model, which depends on several adjustable parameters, to reproduce the experimentally measured effects of inclusions on energy resolution. We also were able to hound the materials-related problem and predict the enhancement in performance expected by reducing the size and number of Te inclusions within ...

Energy Technology Data Exchange (ETDEWEB)

Mass and charge distributions of products from fission of sup(242m)Am induced by thermal neutrons have been investigated by means of the semiconductor spectrometry of ..gamma.. radiation from a mixture of non-separated fragment nuclei. Specimens of the fissible material have been irradiated in the vertical experimental channel of the research reactor then the measurements have been performed with calibrated semiconductor detectors. Three experiments with substantially different irradiation times have been performed to expand the nomenclature of the investigated fission products. The spectra of ..gamma.. radiation from the mixture of fission products, and time dependences of the counting rates at the total absorption peaks have been handled with computers. The obtained yields are compared with data of previous investigations performed with different experimental methods, as well as with the calculated one.

Energy Technology Data Exchange (ETDEWEB)

Fuel elements used in the ORR whole-core LEU fuel demonstration have been gamma-scanned to determine axial distributions of UZLa and TXCs fission product activities. This data has been analyzed to determine cycle-averaged fuel element powers, residual STVU masses, and burnups of discharged fuel elements. Methods used to analyze the data are discussed and results are presented for the LEU fuel elements. Measured and calculates fuel element powers agree to within 5%, residual STVU masses to within 2%, and burnups to within 3%. These results are somewhat preliminary and await improved burnup calculations and independent calibration data to be based on the destructive analyses of a number of irradiated fuel elements. 4 refs., 7 figs., 3 tabs.

International Nuclear Information System (INIS)

We discuss various reactions at future e"+e"- and #gamma##gamma# colliders involving real (beamstrahlung or backscattered laser) or quasi-real (bremsstrahlung) photons in the initial state and hadrons in the final state. The production of two central jets with large transverse momentum p_T is described in some detail; we give distributions for the rapidity and p_T of the jets as well as the di-jet invariant mass, and discuss the relative importance of various initial state configurations and the uncertainties that arise from the at present rather poor knowledge of the parton content of the photon. We also present results for 'mono-jet' production where one jet goes down a beam pipe, for the production of charm, bottom and top quarks, and for single production of W and Z bosons. Where appropriate, the two-photon processes are compared with annihilation reactions leading to similar final states. We also argue that the behaviour of the total ...

International Nuclear Information System (INIS)

It is proposed to measure the spot sizes and polarization of #gamma# beams of future #gamma#e and #gamma##gamma# colliders detecting e"+e"- pairs produced as a result of interaction of high energy #gamma# quanta with density modulated and not modulated laser photons. The quantum electrodynamics cross sections, necessary numerical results as well as a short comparison of the proposed method with some other methods are given. (orig.).

Energy Technology Data Exchange (ETDEWEB)

A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the emitted radiation to bend toward the detector as rays parallel to the detector axis of the detector. The collimator may be a hollow cylinder positioned so that its ...

CERN Document Server

We consider the exact path sampling of the squared Bessel process and some other continuous-time Markov processes, such as the CIR model, constant elasticity of variance diffusion model, and hypergeometric diffusions, which can all be obtained from a squared Bessel process by using a change of variable, time and scale transformation, and/or change of measure. All these diffusions are broadly used in mathematical finance for modelling asset prices, market indices, and interest rates. We show how the probability distributions of a squared Bessel bridge and a squared Bessel process with or without absorption at zero are reduced to randomized gamma distributions. Moreover, for absorbing stochastic processes, we develop a new bridge sampling technique based on conditioning on the first hitting time at zero. Such an approach allows us to simplify simulation schemes. New methods are illustrated with pricing path-dependent options.

CERN Document Server

Suppose an astronomer is equipped with a device capable of detecting emissions -- whether they be electromagnetic, gravitational, or neutrino -- from transient sources distributed throughout the cosmos. Because of source rate density evolution and variation of cosmological volume elements, the sources first detected when the machine is switched on are likely to be ones in the high-redshift universe; as observation time increases, rarer, more local, events will be found. We characterize the observer's evolving record of events in terms of a "probability event horizon", converging on the observer from great distances at enormous speed, and illustrate it by simulating neutron star birth events distributed throughout the cosmos. As an initial application of the concept, we determine the approach of this horizon for gamma-ray bursts (GRBs) by fitting to redshift data. The event rates required to fit the model are consistent with ...

International Nuclear Information System (INIS)

The "1"6O induced fission studies of "2"0"9Bi have been carried out at particle energies of 89.5 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The yield distribution of fission products has been found to be broad (FWHM=16) with a peak near mass 107. The charge distribution in the "1"6O particle induced fission of "2"0"9Bi has been studied at "1"6O particle of 89.5 MeV. The fractional cumulative yields of "9"2Y, "9"7Zr, "9"9Mo, "1"0"1Mo, "1"0"5Rh, "1"1"2Pd and "1"1"7"mCd have been determined using gamma ray spectrometry. (author). 7 refs., 2 tabs.

CERN Document Server

We model the transport of cosmic ray nuclei in the Galaxy by means of a new numerical code. Differently from previous numerical models we account for a generic spatial distribution of the diffusion coefficient. We found that in the case of radially uniform diffusion, the main secondary/primary ratios (B/C, N/O and sub-Fe/Fe) and the modulated antiproton spectrum match consistently the available observations. Convection and re-acceleration do not seem to be required in the energy range we consider: $1 \\le E \\le 10^3$ GeV/nucleon. We generalize these results accounting for radial dependence of the diffusion coefficient, which is assumed to trace that of supernova remnants. While this does not affect the prediction of secondary/primary ratios, the simulated longitude profile of the diffuse $\\gamma$-ray emission is significantly different from the uniform case and may agree with EGRET measurements without invoking {\\it ad hoc} assumptions on ...

International Nuclear Information System (INIS)

We study the spectral evolution of pulsar wind nebulae (PWNe) taking into account the energy injected when they are young. We model the evolution of the magnetic field inside a uniformly expanding PWN. Considering time-dependent injection from the pulsar and coolings by radiative and adiabatic losses, we solve the evolution of the particle distribution function. The model is calibrated by fitting the calculated spectrum to the observations of the Crab Nebula at an age of a thousand years. The spectral evolution of the Crab Nebula in our model shows that the flux ratio of TeV #gamma#-rays to X-rays increases with time, which implies that old PWNe are faint in X-rays, but not in TeV #gamma#-rays. The increase of this ratio is because the magnetic field decreases with time and is not because the X-ray emitting particles are cooled more rapidly than the TeV #gamma#-ray emitting particles. Our spectral ...

International Nuclear Information System (INIS)

Solving a coupled set of differential equations formed by a Fokker-Planck equation and a set of master equations, we can calculate the number of 'prefission' particles (n,p,a), which are emitted from a hot, rotating compound nucleus. Furthermore we get their energy spectrum and their angular momentum distribution. Our results depend sensitively on the friction parameter #gamma#, the inertia M and the fission potential. Comparing the results with experimental data, we may learn something about these quantities. The investigations have been made for "1"8"7Ir and "1"8"5Os. (orig.).

International Nuclear Information System (INIS)

The basic approach to radioactive labeling techniques in hemoglobin identification consists of mixing 14C labeled normal carrier globin with 3H labeled unknown globin and carrying out the subsequent separations and purifications looking at the distribution of 3H and 14C radioactivity. This technique was devised to ascertain the amino acid substitution in Hb Indianapolis and was instrumental in solving the structure of Hb Vicksburg. It was also useful in determining the purity of gamma-chains from cultures of human and baboon erythroid progenitors. Another use of this technique would be in identifying aberrant peaks of radioactivity in chain separation chromatograms, such as ''pre-peaks''.

CERN Document Server

First measurements of inclusive Z production cross sections in muon and electron decay channels at 7 TeV are presented for proton-proton collisions in the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC). The comparison of the kinematic quantities as well as the studies of selection efficiencies demonstrate a good agreement between simulated events and current data. The measured inclusive cross section for Z($\\gamma^{*}$) production agrees with NNLO QCD cross section calculations and current parton distribution functions.

CERN Document Server

We discuss the recent excess seen by the CDF Collaboration in the dijet invariant mass distribution produced in association with a $W$ boson. We analyze the possibility of such a signal within the context of a $U(1)_X$ Stueckelberg extension of the Standard Model where the new gauge boson couples only to quarks. In addition to the analysis of the $Wjj$ anomaly we also discuss the production of $Zjj$ and $\\gamma jj$ at the Tevatron. The analysis is then extended to the Large Hadron Collider with $\\sqrt{s}=7 {\\rm TeV}$ and predictions for the dijet signals are made.

Energy Technology Data Exchange (ETDEWEB)

This report describes the preliminary thermalhydraulic analysis of HTR-10 steady state full power initial core to provide a benchmark calculation of VHTGR(Very High-Temperature Gas-Cooled Reactors) safety analysis code of GAMMA(GAs Multicomponent Mixture Analysis). The input data of GAMMA code are produced for the models of fluid block, wall block, radiation heat transfer and each component material properties in HTR-10 reactor. The temperature and flow distributions of HTR-10 steady state 10 MW{sub th} full power initial core are calculated by GAMMA code with boundary conditions of total reactor inlet flow rate of 4.32 kg/s, inlet temperature of 250 .deg. C, inlet pressure of 3 MPa, outlet pressure of 2.992 MPa and the fixed temperature at RCCS water cooling tube of 50 .deg C. The calculation results are compared with the measured solid material temperatures at 22 fixed instrumentation positions in ...

Energy Technology Data Exchange (ETDEWEB)

The authors study the processes {gamma}e {r{underscore}arrow} {gamma}e and {gamma}{gamma} {r{underscore}arrow} {gamma}{gamma}, in the context of the proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. With an ultraviolet cutoff M{sub S} {approximately} 1 TeV for the effective gravity theory, the cross sections obtained for these processes at the Next Linear Collider (NLC), with the e{gamma} an {gamma}{gamma} options, deviate from the predictions of the Standard Model significantly. The results suggest that, for typical proposed NLC energies and luminosities, the predictions of WSQG can be tested in the range 1 TeV {approx{underscore}lt} M{sub S} {approx{underscore}lt} 10 TeV, making e{gamma} an {gamma}{gamma} colliders important tools for probing WSQG.

International Nuclear Information System (INIS)

The authors have used limited proteolysis of affinity-labeled estrogen receptors (ER), coupled with antireceptor antibody immunoreactivity, to assess structural features of ER and the relatedness of ER from MCF-7 human breast cancer and rat uterine cells. MCF-7 ER preparations covalently labeled with ["3H]tamoxifen aziridine (["3H]TAZ) were treated with trypsin (T), #alpha#-chymotrypsin (C), or Staphylococcus aureus V8 protease prior to electrophoresis on sodium dodecyl sulfate gels. Fluorography revealed a distinctive ladder of ER fragments containing TAZ for each protease generated from the M/sub r/ 66,000 ER. Immunoblot detection with the primate-specific antibody D75P3#gamma# revealed that all immunoreactive fragments corresponded to TAZ-labeled fragments but that some small TAZ-labeled fragments were no longer immunoreactive. In contrast, use of the antibody H222SP#gamma# revealed a correspondence between TAZ-labeled ...

International Nuclear Information System (INIS)

... electrophoresis fission products gamma radiation gamma spectra half-life

International Nuclear Information System (INIS)

Three possibilities to observe the Higgs-top interaction at future #gamma##gamma#-colliders are discussed: a) associated Higss production via the #gamma##gamma##->#tanti tH reaction, b) Higgs obliged radiative correction to the #gamma##gamma##->#tanti t channel, c) Higgs resonance production via #gamma##gamma##->#H#->#ZZ. The results obtained show windows of the Higss mass where the Yukawa interaction of the Higss with the top quark can be studied at #gamma##gamma#-colliders. (orig.).

International Nuclear Information System (INIS)

The purpose of this study was to investigate the feasibility of a simple deformable phantom as a QA tool for testing and validation of deformable image registration algorithms. A diagnostic thoracic imaging phantom with a deformable foam insert was used in this study. Small plastic markers were distributed through the foam to create a lattice with a measurable deformation as the ground truth data for all comparisons. The foam was compressed in the superior-inferior direction using a one-dimensional drive stage pushing a flat 'diaphragm' to create deformations similar to those from inhale and exhale states. Images were acquired at different compressions of the foam and the location of every marker was manually identified on each image volume to establish a known deformation field with a known accuracy. The markers were removed digitally from corresponding images prior to registration. Different image registration algorithms were tested using ...

Energy Technology Data Exchange (ETDEWEB)

The US Department of Energy (DOE) has millions of gallons of high level nuclear waste stored in underground tanks at Hanford, Washington and Savannah River, South Carolina. These tanks will eventually be emptied and decommissioned. This will leave a residue of sludge adhering to the interior tank surfaces that may contaminate nearby groundwaters with radionuclides and RCRA metals. Performance assessment (PA) calculations must be carried out prior to closing the tanks. This requires developing radionuclide release models from the sludges so that the PA calculations can be based on credible source terms. These efforts continued to be hindered by uncertainties regarding the actual nature of the tank contents and the distribution of radionuclides among the various phases. In particular, it is of vital importance to know what radionuclides are associated with solid sludge components. Experimentation on actual tank sludges can be difficult, dangerous ...

International Nuclear Information System (INIS)

The microstructural development and grain-coarsening behavior of WC-Co alloys, with and without a VC additive, were investigated. The primary goal was to determine the mechanism through which VC acts as a grain-growth inhibitor. The study involved long-time sintering experiments (1 to 100 hours) on fully dense material, nascent stage sintering (90 to 1,320 seconds) starting with the green compact, and surrogate liquid phase experiments to characterize the WC powder prior to sintering. Quantitative microstructural analysis using intercept length distributions was performed for the long-term sintering. The nascent stage experiments involved the measurement of the specific surface area (S_v) of each type of interface separately allowing the determination of the contribution of each developing entity to the overall microstructural evolution. The VC addition has been found to enhance the breakup of multigrained particles in the earliest stages of ...

CERN Document Server

This paper focuses on the cross-layer issue of joint multiuser detection and resource allocation for energy efficiency in wireless CDMA networks. In particular, assuming that a linear multiuser detector is adopted in the uplink receiver, the case considered is that in which each terminal is allowed to vary its transmit power, spreading code, and uplink receiver in order to maximize its own utility, which is defined as the ratio of data throughput to transmit power. Resorting to a game-theoretic formulation, a non-cooperative game for utility maximization is formulated, and it is proved that a unique Nash equilibrium exists, which, under certain conditions, is also Pareto-optimal. Theoretical results concerning the relationship between the problems of SINR maximization and MSE minimization are given, and, resorting to the tools of large system analysis, a new distributed power control algorithm is implemented, based on very little prior ...

CERN Document Server

The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed Serial Crystallography method, the damage problem is addressed by distributing the total dose over many identical hydrated macromolecules running continuously in a single-file train across a continuous X-ray beam, and resolution is then limited only by the available molecular and X-ray fluxes and molecular alignment. Orientation of the diffracting molecules is achieved by laser alignment. We evaluate the incident X-ray fluence (energy/area) required to obtain a given resolution from (1) an analytical model, giving the count rate at the maximum scattering angle for a model protein, (2) explicit simulation of diffraction patterns for a GroEL-GroES protein complex, and (3) the frequency cut off of the transfer function following iterative solution of the phase problem, and reconstruction of an electron density ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of the Power-One Aerocapacitor Commercialization Plan is to communicate to members of management and to all employees the overall objectives of the corporation. Power-One, Inc., has participated in a US Federal Government Technology Reinvestment Project (TRP), entitled {open_quotes}Advanced Power Conversion based on the Aerocapacitor{close_quotes}: the project is a group effort, with Lawrence Livermore National Labs, GenCorp/Aerojet, PolyStor Corp. (a start-up company), and Power-One forming the consortium. The expected resulting technology is the {open_quotes}Aerocapacitor{close_quotes}, which possesses much higher performance levels than the usual capacitors on the market today. Power-One hopes to incorporate the Aerocapacitor into some of its products, hence enhancing their performance, as well as market privately-labeled aerocapacitors through its distribution channels. This document describes the details of Power-One`s plan to bring to market and ...

International Nuclear Information System (INIS)

We investigate the coupling between rock-size solids and gas during the formation of gas giant planets by disk fragmentation in the outer regions of massive disks. In this study, we use three-dimensional radiative hydrodynamic simulations and model solids as a spatial distribution of particles. We assume that half of the total solid fraction is in small grains and half in large solids. The former are perfectly entrained with the gas and set the opacity in the disk, while the latter are allowed to respond to gas drag forces, with the back reaction on the gas taken into account. To explore the maximum effects of gas-solid interactions, we first consider 10 cm size particles. We then compare these results to a simulation with 1 km size particles, which explores the low-drag regime. We show that (1) disk instability planets have the potential to form large cores due to aerodynamic capturing of rock-size solids in spiral arms before fragmentation; (2) temporary clumps ...

Energy Technology Data Exchange (ETDEWEB)

Water model experiments were conducted to develop a two-stage stirring method for obtaining higher yields and a more uniform distribution of graphite particles in copper alloys. This was followed by several melts for synthesis of copper-graphite alloys in which Ti was used as a wetting agent to improve the wettability of graphite in the copper melt. In the first stage, a vortex method was employed to facilitate the addition of graphite particles into the copper melt. In the second stage, a specially designed stirrer was used for uniform particle distribution while avoiding the formation of vortex in the melt. The two-stage stirring was found to considerably improve the recovery of graphite, over those obtained with the prior practice of single-stage stirring and resulting in a more uniform particle distribution. In addition, graphite recoveries increased with increasing Ti content in the range ...

Energy Technology Data Exchange (ETDEWEB)

Inelastic scattering of 180 MeV {pi}{sup +} and {pi}{sup {minus}} from {sup 52}Cr shows an angular distribution for the 2{sub 2}{sup +} state at 2.96 MeV that differs greatly from the usual {ital L} = 2 shapes for 2{sup +} states. This state is perhaps the only case from pion-inelastic scattering in which standard distorted-wave impulse approximation models (including multistep and single-step responses) fail to reproduce the measured angular distribution. Furthermore, this unique excitation has been shown to have the features expected of a seniority-four proton excitation yet the pion data show charge symmetry. While coupled-channel calculations are not able to reproduce the pion data, they do agree with the shape observed for 42 MeV {alpha} particle scattering to this state, but the magnitude of the {alpha} scattering data is not consistent with a collective model and known {gamma} ray deexcitations. Scattering to the ...

UK PubMed Central (United Kingdom)

BackgroundThe aim of this study was to investigate the relationship between prior Anisakis infections and upper gastrointestinal bleeding (UGIB), and its interaction...Full Text Available

Science.gov (United States)

Prior to this at TRW, Mr. Schier managed flight software development on the MILSTAR Communications Payload and led integration and verification work on ...

Energy Technology Data Exchange (ETDEWEB)

Short communication

Energy Technology Data Exchange (ETDEWEB)

Future linear colliders offer unique opportunities to study {gamma}{gamma}, {gamma}e interactions. Using the laser backscattering method one can obtain {gamma}{gamma}, {gamma}e colliding beams with energy and luminosity comparable to the electron-position luminosity or even higher. In this review physical principles of photon colliders are described and various problems, concerning the accelerator, laser, interaction region and luminosity are discussed. Some examples of physical processes are given. ((orig.)).

Energy Technology Data Exchange (ETDEWEB)

The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the only major protection to astronauts from harmful exposure. Unlike low-linear energy transfer (LET) {gamma} or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure, since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak. The Bragg curve does not necessarily represent the biological damage along the particle traversal, and the 'biological Bragg curve' is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. Here we used a unique irradiation geometry to measure the biological response across the Bragg curve in human fibroblasts exposed to 577MeV/nucleon incident Fe ions in vitro. ...

Energy Technology Data Exchange (ETDEWEB)

The angular ..gamma gamma..-correlations for nuclei of Sr even-even isotopes with A=82, 84, 86, 88 were measured. Multipole structurs of ..gamma..-transtion series and th coefficients multipole mixing were determined.

Science.gov (United States)

The gamma spectrum and gamma - gamma coincidences of /sup 177/W were measured with a Ge(Li) detector. A level scheme was proposed for /sup 177/Ta. (tr-auth)

International Nuclear Information System (INIS)

In this thesis, the potential to discover supersymmetric signatures in both e"+e"- and #gamma##gamma# colliders evaluated with a Monte Carlo analysis, is discussed. The analysis was focused on the detection of muons, essentially. First, we study the detection of #mu#"+_R#mu#"-_R in e"-e"+ collisions, whose purpose is the measurement of the #mu#_R mass. It was found that an uncertainty of 0.11 GeV (stat) can be achieved. Under the assumption of the real conditions of the ILC photon collider, a study covering the detection of #mu#"+_R#mu#"-_R and #mu#"+_L#mu#"-_L pairs for #sq root#(s_e_"-_e_"+)=0.5 and 0.6 TeV was performed. According to the simulation, a statistical error for the branching ratios of #mu#"#+-#_L#->##chi#"0_1#mu#"#+-# of 0.98% and #mu#"#+-#_L#->##chi#"0_2#mu#"#+-# of 3.97% can be reached. In order to judge the Monte Carlo results, we have used a technique based on a multidimensional fit to evaluate the impact of the branching ratio measurements ...

Energy Technology Data Exchange (ETDEWEB)

The proton beam has a unique advantage over the electron and photon beams in that it can give very high radiation dose to the tumor volume, while effectively sparing the neighboring healthy tissue and organs. For the clinical application of the proton beam, it is very important to confirm the location of the proton beam in the patient, preferentially during the treatment. It has been suggested that the range of the proton beam in the patient can be determined by measuring prompt gammas from the proton beam passage. Recently, a prototype prompt-gamma scanning system has been constructed and tested using experimental and therapeutic proton beams. The measurement results for the proton beams of 70 . 230 MeV showed that a clear correlation exists between the distribution of the prompt gammas and the proton beam range. The scanning method, however, is not suitable for the upcoming 'spot ...

Energy Technology Data Exchange (ETDEWEB)

The first radon soil gas survey in Serbia, using passive detectors (SSNTD, CR-39), was carried out in June 2005 at field sites in Niska Banja town. The aim of the survey was to identify risk zones characterised by high levels of this radioactive gas. Radon measurements were made at the depth of 50 cm, in the ground according to a systematic grid pattern. Furthermore, at all 48 measurement points, the surface gamma dose rates in the air was also measured at the same locations and soil samples were collected for gamma spectrometric analysis for the radionuclides {sup 226}Ra, {sup 228}Th and {sup 40}K. Radon concentrations were found to range from 1270 to 155000Bqm{sup -3} with an average of 33765Bqm{sup -3} and a median value of 12626Bqm{sup -3}. The geometrical mean value and geometrical standard deviation were calculated as 16160Bqm{sup -3} and 3.5Bqm{sup -3}, respectively. Gamma dose rate varies from 92 to 316nGyh{sup -1}, ...

Energy Technology Data Exchange (ETDEWEB)

We present methods to measure the beam polarizations and the luminosity of [gamma][gamma] colliders at TeV energy scale. The beam polarizations of a [gamma][gamma] collider can easily be monitored by comparing the numbers of events of the processes [gamma][gamma] [yields] l[sup +]l[sup -] and [gamma][gamma] [yields] W[sup +] W[sup -], where l means e or [mu]. The luminosity of a [gamma][gamma] collider is also measurable by the event rate of W boson pair productions and the light lepton pair productions. (orig.)

International Nuclear Information System (INIS)

The DNA double-strand break (DSB) damage response induced by high energy charged particles on lung fibroblast cells embedded in a 3-dimensional (3-D) collagen tissue equivalents was investigated using antibodies to the DNA damage response proteins gamma-histone 2AX (#gamma#-H2AX) and phosphorylated DNA-PKcs (p-DNA-PKcs). 3-D tissue equivalents were irradiated in positions across the linear distribution of the Bragg curve profiles of 307.7 MeV/nucleon, 556.9 MeV/nucleon, or 967.0 MeV/nucleon "5"6Fe ions at a dose of 0.30 Gy. Patterns of discrete DNA damage streaks across nuclei or saturated nuclear damage were observed, with saturated nuclear damage being more predominant as samples were positioned closer to the physical Bragg peak. Quantification of the DNA damage signal intensities at each distance for each of the examined energies revealed a biological Bragg curve profile with a pattern of DNA damage intensity similar to ...

CERN Document Server

Process algebra for parallel and distributed processing

International Nuclear Information System (INIS)

To dispose the radioactive waste drums, the waste form's integrity and the nuclides inventories must be assured according to the national and site waste acceptance criteria. Because they might be would gravely affected the performance objectives of disposal site. Our national regulation for the waste inventory related to 'Radioactive Waste Acceptance Criteria' requires that the activities of 13 nuclides and gross #alpha# must be measured and the 95 % of nuclides incorporated in the drum must be identified. It is very difficult to measure the radioactivity with accuracy from the regulated waste drum(200L), and have a large error in the analysis results. In present, there are two system, SGS (Segmented Gamma Scanning System) and TGS (Tomographic Gamma Scanning System) for the analysis of radionuclides from the waste drums. In general, it is known that the accuracy of TGS is below 20 % and that of SGS is below 30 %. The accuracy of TGS is better ...

Energy Technology Data Exchange (ETDEWEB)

Natural radioactive materials under certain conditions can reach hazardous radiological levels. The natural radionuclide ({sup 238}U, {sup 232}Th, {sup 40}K) contents of rock samples at various locations in the North Tushki area were investigated using gamma-spectrometric analysis. Estimates of the measured radionuclide content have been made for the absorbed dose rate of gamma radiation. The equivalent radium (R{sub eq}) and the external hazard index (H{sub ex}) which resulted from the natural radionuclides in soil are also calculated and tabulated. The studied samples have been collected from various rock exposures in the North Tushki area. The distribution of major oxides, U and Th were studied. It is found that the enrichment and depletion of the major oxides are mainly due to the effect of hydrothermal alteration, which caused mobility of some major oxides, which increases some elements and decreases others. It is ...

Energy Technology Data Exchange (ETDEWEB)

The accurate prediction of local hot spot during normal operation is important to ensure core thermal margin in a very high temperature gas-cooled reactor because of production of its high temperature output. The active cooling of the reactor core determining local hot spot is strongly affected by core bypass flows through the inter-column gaps between graphite blocks and the cross gaps between two stacked fuel blocks. The bypass gap sizes vary during core life cycle by the thermal expansion at the elevated temperature and the shrinkage/swelling by fast neutron irradiation. This study is to investigate the impacts of the variation of bypass gaps during core life cycle as well as core restraint mechanism on the amount of bypass flow and thus maximum fuel temperature. The core thermo fluid analysis is performed using the GAMMA+ code for the PMR200 block-core design. For the analysis not only are some modeling features, developed for solid conduction and bypass flow, ...

CERN Document Server

If gamma-ray bursts originate in galaxies at cosmological distances, the host galaxy should be detected if a burst error box is searched deep enough; are the host galaxies present? We present and implement a statistical methodology which evaluates whether the observed galaxy detections in a burst's error box are consistent with the presence of the host galaxy, or whether all the detections can be attributed to unrelated background galaxies. This methodology requires the model-dependent distribution of host galaxy fluxes. While our methodology was derived for galaxies in burst error boxes, it can be applied to other candidate host objects (e.g., active galaxies) and to other types of error boxes. As examples, we apply this methodology to two published studies of burst error boxes. We find that the nine error boxes observed by Larson and McLean (1997) are too large to discriminate between the presence or absence of host galaxies, while the ...

International Nuclear Information System (INIS)

The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm"-"3 or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant applications. ...

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the gamma function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the l...

British Library Electronic Table of Contents (United Kingdom)

Monthly rainfall data from June to October for 39 years were used to compute Standardized Precipitation Index (SPI) values based on two parameter gamma distribution for a low rainfall and a high rainfall districts of Andhra Pradesh state, India. Comparison of SPI with actual rainfall and rainfall deviation from the mean indicated that SPI values under-estimate the intensity of dryness/wetness when the rainfall is very low/very high, respectively. As a result, the SPI in the worst drought years of 2002 and 2006 in the low rainfall district indicated only moderate dryness instead of extreme dryness. SPI values of the high rainfall district showed slightly better stretching in both positive and negative directions, compared to that of the low rainfall district. Further, the SPI values of long...

Energy Technology Data Exchange (ETDEWEB)

Proton induced X-ray emission (PIXE) and proton induced {gamma}-ray emission (PIGE) techniques are employed for the determination of essential and trace elements in some commonly used medicinal plants of north east India. Light elements such as Na, Mg, Al and P are determined by PIGE while medium Z elements such as K, Ca, Mn, Fe, Cu, Zn, Rb and Sr are determined by PIXE. Analysis is performed on pellets (thick targets) prepared using powders of the specimens which, in turn, are obtained following a series of processing steps. Plant based biological certified reference materials (CRMs) served as standards for quantification. These elements are found to be present in varying concentrations in the studied plants, with the contents of Mn and Zn being notably large in certain specimens. Medicinal properties possessed by these plants have been correlated with their elemental distribution.

International Nuclear Information System (INIS)

Prompt fission neutron energy spectra for "2"3"5U and "2"3"9Pu have been measured for fission neutron energies greater than the energy of the incident neutrons inducing fission. The measurements were undertaken to investigate the shape dependence of the fission neutron spectra upon both the incident neutron energy and the mass of the nucleus undergoing fission. Measurements were made for both nuclides at incident neutron energies of 0.50, 1.50, 2.50 and 3.50 MeV. The data are presented either as relative yields or as ratios of measured spectra to that of "2"3"5U at 0.50 MeV. Incident neutrons were produced by the "7Li(p,n)"7Be reaction using a pulsed, bunched proton beam from the 5.5 MV Van de Graaff accelerator at the University of Massachusetts Lowell Radiation Laboratory. Fission neutrons were detected by a thin liquid scintillator with good time resolution capabilities. Neutron energies were determined by time-of-flight techniques with pulse-shape discrimination to reduce ...

International Nuclear Information System (INIS)

In this talk I briefly summarize different models for #sigma#_2_#gamma#"t"o"t (e"+e"-#->##gamma##gamma##->#hadrons) and contrast model predictions with the data. I will then discuss the capability of the future e"+e"- and #gamma##gamma# colliders to distinguish between various models and end with an outlook for future work.

Energy Technology Data Exchange (ETDEWEB)

We investigate the chargino production process {gamma}{gamma} {yields} (W-tilde){sup +}(W-tilde){sup -} at high energy {gamma}{gamma} colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy {gamma} beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV ee colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section to for us extract the signal from the dominant background {gamma}{gamma} {yields} W{sup +}W{sup -}. (author).

International Nuclear Information System (INIS)

The tissue distribution of "1"3"1I-transferrin ("1"3"1I-Tf) was studied in athymic nude mice having s.c. human colonic adenocarcinoma HT-29 xenografts. Four days after "1"3"1I-Tf injection, the "1"3"1I specific activity measured in the HT-29 tumor, i.e. amount of radioactivity per gram of fresh tissue, represented 0.31 #+-# 0.09% of the injected radioactivity and was 1.90 fold more than that measured in the murine colon (P < 0.05). After correction for intravascular "1"3"1I-Tf as estimated by mean of "9"9"mTc-Sn in vivo labeling of red blood cells, the "1"3"1I specific activity observed in the HT-29 tumor was 7.21 fold more than that observed in the murine colon. This subtracting method enabled us to localize a HT-29 tumor xenograft by #gamma# scintigraphy of the entire animal and demonstrated that "1"3"1I-Tf could be a non-specific but potent marker for human colon cancer. (author).

CERN Document Server

We discuss the estimation of galaxy correlation properties in several volume limited samples, in different sky regions, obtained from the Fourth Data Release of the Sloan Digital Sky Survey. The small scale properties are characterized through the determination of the nearest neighbor probability distribution. By using a very conservative statistical analysis, in the range of scales [0.5,~30] Mpc/h we detect power-law correlations in the conditional density in redshift space, with an exponent \\gamma=1.0 \\pm 0.1. This behavior is stable in all different samples we considered thus it does not depend on galaxy luminosity. In the range of scales [~30,~100] Mpc/h we find evidences for systematic unaveraged fluctuations and we discuss in detail the problems induced by finite volume effects on the determination of the conditional density. We conclude that in such range of scales there is an evidence for a smaller power-law index of the conditional ...

Energy Technology Data Exchange (ETDEWEB)

By generalizing the algebra satisfied by the ..gamma../sub 5/ matrix, it is possible to give an extension of ..gamma../sub 5/ to d dimensions. We discuss the connection of this scheme to others.

International Nuclear Information System (INIS)

In the beginning of 2005 several changes in the electricity and natural gas market law came into effect. This report examines the influence and impact of these changes on the behaviour and development of these markets, looking at the role and position of both the energy industry and customers. The report combines existing data with new research data collected during spring and summer 2006. Whilst the recency of the law changes, along with the simultaneous impact of other market variables limits the salience of any impact, the report nevertheless provides clear and interesting conclusions. In the electricity market, one major legislative change that came into force in the beginning of 2005 concerned the supervision of the reasonableness of electricity distribution pricing. According to the newly adopted ex ante regulation principles, the regulatory authority now determines the guidelines for reasonable pricing prior the start of a predefined ...

Energy Technology Data Exchange (ETDEWEB)

During cleanup of contaminated sites, Sandia National Laboratories, New Mexico (SNL/NM) frequently encounters soils with low-level radioactive contamination. The contamination is not uniformly distributed, but occurs within areas of clean soil. Because it is difficult to characterize heterogeneously contaminated soils in detail and to excavate such soils precisely using heavy equipment, it is common for large quantities of uncontaminated soil to be removed during excavation of contaminated sites. This practice results in the commingling and disposal of clean and contaminated material as low-level waste (LLW), or possibly low-level mixed waste (LLMW). Until recently, volume reduction of radioactively contaminated soil depended on manual screening and analysis of samples, which is a costly and impractical approach and does not uphold As Low As Reasonably Achievable (ALARA) principles. To reduce the amount of LLW and LLMW generated during the excavation process, ...

Energy Technology Data Exchange (ETDEWEB)

Except nuclear industry, diverse structures (hospitals, of research or manufacturers) can have appeal to the use of radioisotopes conditioned under unsealed shape. Such practices lead to tolerate releases in environment in the respect of a statutory device. So the collective network can contain radioisotopes the future of which is going to depend partially on the cleaning applied to waste water. This study through the analysis of a concrete case, has for objective to inform about the future of gamma radioelements present in waste water treated by a wastewater treatment plant. The contamination of the network is essentially due to Tc{sup 99} and I{sup 131}, radioelements present whatever the working day and the hour considered. The total estimated in-load for a day is important, of the order of 4000 MBq for Tc{sup 99} and 15 to 300 MBq for I{sup 131}. The assessment of cleaning of the station shows that this one plays a role towards this pollution through these ...

International Nuclear Information System (INIS)

Three resonances at the proton energies 7.0, 7.08, and 7.53 MeV on the target "8"8Sr were chosen to investigate the possibility of determining the amplitudes of the weak coupling experimentally. The corresponding "8"9Sr levels under investigation were 1.93 MeV ("5/_2"+), 2.00 MeV ("3/_2"+), and 2.46 MeV ("3/_2"+). Angular distributions were measured on resonance at 7.0, 7.08, and 7.53 MeV from proton inelastic scattering to the 1.84 MeV (2"+) state of "8"8Sr for differential cross section, analyzing power, spin-flip probability, and spin-flip asymmetry. A polarized beam of protons was used to obtain the analyzing power. The spin-flip probability was obtained from the coincidence of the prompt gamma rays from the (p,p'#gamma#) reaction with the scattered protons. With the polarized beam, the gamma coincidence technique was further used to obtain a spin-flip asymmetry measurement. From these measurements, ...

International Nuclear Information System (INIS)

Short communication.

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Short communication.

Energy Technology Data Exchange (ETDEWEB)

We study the production of three gauge bosons ([ital W][sup +][ital W][sup [minus

International Nuclear Information System (INIS)

... chemical radiation effects decomposition extraction columns gamma radiation

Energy Technology Data Exchange (ETDEWEB)

We consider the possibility of detecting a heavy Higgs boson ([ital m][sub [ital H

Science.gov (United States)

Jan 13, 2011 ... This 360-degree mosaic of images from the navigation camera on ... The Radiation Assessment Detector, shown prior to its September 2010 ...

Science.gov (United States)

Jan 18, 2011 ... The Radiation Assessment Detector, shown prior to its September 2010 ... This 360-degree panorama shows the vista from the location where ...

UK PubMed Central (United Kingdom)

The visual outcome, histopathology, and electrodiagnostic tests of a man with a malignant melanoma of the choroid who received foveal argon laser photocoagulation prior to enucleatiion are described....Full Text Available

UK PubMed Central (United Kingdom)

BackgroundPrior research links optimism to physical health, but the strength of the association has not been systematically evaluated.PurposeFull Text Available

Science.gov (United States)

... A technique of the prior art uses an acousto-optic Q-switch which can ... Another approach uses electro-optic Q-switches in a pseudo cavity dumping ...

Energy Technology Data Exchange (ETDEWEB)

We summarize the predictions of different models for total {gamma}{gamma} cross-sections. The experimentally observed rise of {sigma}{sub {gamma}}{sub {gamma}} with s radical {sub {gamma}}{sub {gamma}}, faster than that for {sigma}{sub p-barp}, {sigma}{sub {gamma}}{sub p} is in agreement with the predictions of the Eikonalized Minijet Models as opposed to those of the Regge-Pomeron models. We then show that a measurement of {sigma}{sub {gamma}}{sub {gamma}} with an accuracy of < or approx. 8-9% (6-7%) is necessary to distinguish among different Regge-Pomeron type models (the different parameterisations of the EMM models) and a precision of < or approx. 20% is required to distinguish the predictions of the EMMs and of those models which treat 'photon like a proton', for the energy range ...

Energy Technology Data Exchange (ETDEWEB)

We analyze spin correlations between top quark and anti-top quark produced at polarized e{sup +} e{sup -} and {gamma}{gamma} colliders. We consider a generic spin basis to find a strong spin correlation. Optimal spin decompositions for top quark pair are presented for e{sup +}e{sup -} and {gamma}{gamma} colliders. We show the cross- section in these bases and discuss the characteristics of results.

International Nuclear Information System (INIS)

In the framework of the equivalence theorem the one-loop helicity amplitudes and cross section for the double Higgs production process #gamma##gamma##->#HH are calculated. It is shown that the cross section is measurable at TeV #gamma##gamma# colliders and is marginally sensitive to the triple-Higgs variation. (orig.).

International Nuclear Information System (INIS)

The complementarity of e"+e"- and #gamma##gamma# colliders to discover and explore new physics beyond the Standard Model (SM) is discussed. After briefly surveying a number of various new physics scenarios, we concentrate in detail on signatures for Large Extra Dimensions via the process #gamma##gamma##->#WW.

Energy Technology Data Exchange (ETDEWEB)

Peroxisome proliferator activated receptor-{gamma} (PPAR{gamma}) regulates metabolic homeostasis and adipocyte differentiation, and it is activated by oxidized and nitrated fatty acids. Here we report the crystal structure of the PPAR{gamma} ligand binding domain bound to nitrated linoleic acid, a potent endogenous ligand of PPAR{gamma}. Structural and functional studies of receptor-ligand interactions reveal the molecular basis of PPAR{gamma} discrimination of various naturally occurring fatty acid derivatives.

Energy Technology Data Exchange (ETDEWEB)

From April 1990 through January 1991, the feasibility of recycling Navy shipboard-generated plastic wastes was explored. Normally, plastic wastes are source separated aboard Navy ships and retained for shoreside disposal in accordance with new fleet requirements implementing MARPOL Annex V that prohibits the discharge of plastics at sea. Over 23,000 pounds of shipboard plastic wastes from USS Lexington (AVT 16) and ships from the Norfolk Naval Base were recycled into park benches, picnic tables and carstops that have been distributed back to the Navy bases for use. Navy shipboard plastics must undergo sorting prior to recycling because Navy plastic waste contains large quantities of composite plastic items (e.g., plastic/paper) that are not easily recyclable. Recycling food-contaminated plastics is not practical due to sanitation problems encountered during handling. However, certain items have good resale value if separated by resin type and ...

Energy Technology Data Exchange (ETDEWEB)

Amorphization and a dual implant technique have been used to manipulate residual defects that persist following implantation and post-implant thermal treatments. Residual defects can often be attributed to ion-induced defect excesses. A defect is considered to be excess when it occurs in a localized region at a concentration greater than its complement. Sources of excess defects include spatially separated Frenkel pairs, excess interstitials resulting from the implanted atoms, and sputtering. Preamorphizing prior to dopant implantation has been proposed to eliminate dopant broadening due to ion channeling as well as dopant diffusion during subsequent annealing. However, transient-enhanced diffusion (TED) of implanted boron has been observed in pre-amorphized Si. The defects driving this enhanced boron diffusion are thought to be the extended interstitial-type defects that form below the amorphous-crystalline interface during implantation. A dual implantation ...

Energy Technology Data Exchange (ETDEWEB)

The presence of water in export coals increases transport and handling costs. Coarse (+0.5 mm) coal constitutes the majority of the product, and small changes in its final moisture content will have a significant effect on overall product moisture. An on-line moisture monitor was installed on a product belt immediately after a coarse coal centrifuge to continuously measure the moisture content of the coal from a single centrifuge. Basic studies were also conducted with a laboratory centrifuge specifically designed to characterize various coarse coal samples in terms of their water retention capacity. The moisture of the coarse coal (typically 6 to 9%) was found to vary by at least 1% at a particular plant, and by a number of percentage points between plants. An empirical model has been developed which can explain about 80% of the moisture variation from the 25 samples investigated. The rank of the coals ranged from 0.7 to 1.65% mean reflectance. The model identified four principle ...

International Nuclear Information System (INIS)

Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, transmission electron microscopy measurements of implantation damage were combined with B diffusion experiments using doping marker structures grown by molecular-beam epitaxy (MBE). Damage from nonamorphizing Si implants at doses ranging from 5x10"1"2 to 1x10"1"4/cm"2 evolves into a distribution of #left brace#311#right brace# interstitial agglomerates during the initial annealing stages at 670 endash 815 degree C. The excess interstitial concentration contained in these defects roughly equals the implanted ion dose, an observation that is corroborated by atomistic Monte Carlo simulations of implantation and annealing processes. The injection of interstitials from the damage region involves the dissolution of #left brace#311#right brace# defects during Ostwald ...

International Nuclear Information System (INIS)

Accurate modeling of system response and scatter distribution is crucial for image reconstruction in emission tomography. Monte Carlo simulations are very well suited to calculate these quantities. However, Monte Carlo simulations are also slow and many simulated counts are needed to provide a sufficiently exact estimate of the detection probabilities. In order to overcome these problems, we propose to split the simulation into two parts, the detection system and the object to be imaged (the patient). A so-called 'virtual boundary' that separates these two parts is introduced. Within the patient, particles are simulated conventionally. Whenever a photon reaches the virtual boundary, its detection probability is calculated analytically by evaluating a multi-dimensional B-spline that depends on the photon position, direction and energy. The unknown B-spline knot values that define this B-spline are fixed by a prior 'pre-' simulation that needs to ...

Energy Technology Data Exchange (ETDEWEB)

It is planned to use the tritium dose model, DCART (Doses from Chronic Atmospheric Releases of Tritium), to reconstruct dose to the hypothetical maximally exposed individual from annual routine releases of tritiated water (HTO) and tritiated hydrogen gas (HT) from all Lawrence Livermore National Laboratory (LLNL) facilities and from the Sandia National (SNL) Laboratory's Tritium Research Laboratory over the last fifty years. DCART has been described in Part 1 of ''Historical Doses From Tritiated Water And Tritiated Hydrogen Gas Released To The Atmosphere from Lawrence Livermore National Laboratory (LLNL)'' (UCRL-TR-205083). This report (Part 2) summarizes information about annual routine releases of tritium from LLNL (and SNL) since 1953. Historical records were used to derive facility-specific annual data (e.g., source terms, dilution factors, ambient air concentrations, meteorological data, including absolute humidity and rainfall, etc.) ...

Energy Technology Data Exchange (ETDEWEB)

The Ordos Basin of north-central China is well known for vast energy resources. This nonmarine interior basin developed on the North China-Korean platform following the Late Triassic Indochina orogeny and, for a time, contained a large freshwater lake prior to being uplifted into its present form at the close of the Mesozoic. Lower to Middle Jurassic coal occurs in the fluviolacustrine Yan'an Formation along the southern margin of the basin in the Huanglong coalfield. In the northeast part of the field, the formation ranges from 0 to 180 m in thickness and is divided into five fining-upward members, each representing a regressive-transgressive lacustrine cycle. Low-sulfur, high-volatile bituminous coal is complexly distributed in the lowest member of the Yan'an Formation. Deposition of this member was influenced by two tectonic events that controlled coal occurrence. First, regional uplifts were produced by the Late Triassic ...

International Nuclear Information System (INIS)

We investigate the sparticle production processes e#gamma# #-># e tilde(Z tilde)_1 and #gamma##gamma# #-># (f tilde)(f tilde and bar) at high energy e#gamma# and #gamma##gamma# colliders in the framework of the minimal supersymmetric standard model (MSSM). It will be shown that the e#gamma# colliders would be more suitable in searching for the heavy selectrons than ee colliders because of the low mass threshold of the process e#gamma# #-># (e tilde)(Z tilde)_1. We show that the standard background processes e#gamma# #-># #nu#W and eZ can be suppressed in terms of initial beam polarization as well as the kinematical cuts on the energy and angle of the final electron. Moreover, it will be argued that the experimental measurements of the cross sections for the processes e#gamma# #-># (e tilde)(Z tilde)_1 and ...

International Nuclear Information System (INIS)

We analyze the potential of the e"+e"- linear colliders, operating in the e#gamma# and #gamma##gamma# modes, to probe anomalous quartic vector-boson interactions through the multiple production of W's and Z's. We examine all SU(2)_L(circle times)U(1)_Y chiral operators of order p"4 that lead to new four-gauge-boson interactions but do not alter trilinear vertices. We show that the e#gamma# and #gamma##gamma# modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10"-"2 at 90% C.L. Moreover, the information gathered in the e#gamma# mode can be used to reduce the ambiguities of the e"+e"- mode.

Energy Technology Data Exchange (ETDEWEB)

Anti-carcinoembryonic antigen monclonal antibody (MAb) CEA 102 was produced by immunization with purified CEA and the specific accumulation of radiolabeled CEA 102 in colorectal cancers was investigated by autoradiography of sugical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with {sup 131}I-labeled intact CEA 102 or its F(ab'){sub 2}. Primary tumor and liver metastases were successfully detected by external scanning with a gamma camera in 4 cases. Autoradiographic study of the surgical specimens using FCR showed predominant localization of {sup 131}I-labeled CEA 102 in primary tumors and liver metastases in all cases. Even a small liver metastasis (0.5 cm) was clearly visualized in the autoradiogram by FCR. The pixel distribution curves of the density of the respective tissues in the autoradiograms by FCR showed the heterogeneity of the ...

UK PubMed Central (United Kingdom)

Background:Acute Coronary Syndrome (ACS) can occur in patients with prior coronary artery bypass grafting (CABG). In the Gulf Registry of acute coronary events (Gulf RACE), we identified...Full Text Available

CERN Document Server

An electroweak singlet scalar can couple to pairs of vector bosons through loop-induced dimension five operators. Compared to a Standard Model Higgs boson, the singlet decay widths in the diphotons and Z gamma channels are generically enhanced, while decays into massive final states like WW and ZZ are kinematically disfavored. The overall event rates into gamma gamma and Z gamma can exceed the Standard Model expectations by orders of magnitude. Such a singlet may appear as a resonant signal in the gamma gamma and Z gamma channels, even with a mass above the WW kinematic threshold.

International Nuclear Information System (INIS)

Corrosion testings of model alloys, corresponding by chemical composition to simple and complex-alloyed #gamma#- and #gamma#'-phases of nickel heat-resistant alloys are conducted in sodium sulfate and chloride melts. It is ascertained that heat resistant nickel alloys containing over 50 % of hardening #gamma#'-phase, are subject to disastrous sulfide corrosion (SC). Resistance against SC alloys containing below 50 % of #gamma#'-phase is determined by the resistance of #gamma#-solid solution. 10 refs., 3 figs., 2 tabs.

International Nuclear Information System (INIS)

We calculate the cross sections for the single production of doubly charged dileptons, both scalar and vector, at e"+e"-, e#gamma#, and #gamma##gamma# colliders at #sq root#s =500 GeV and 1 TeV. The e#gamma# mode is by far the most promising---dileptons whose coupling is as weak as #approx#10"-"4#alpha#_e_m can be observed, for masses virtually up to the kinematic limit. Dileptons of mass up to #sq root#s can also be seen in e"+e"- and #gamma##gamma# colliders, for couplings of order #alpha#_e_m. In all three colliders, most of the cross section comes from events in which the only particles detected are e"-e"- (or #mu#"-#mu#"- or #tau#"-#tau#"-), the decay products of the dilepton, yielding an unmistakable experimental signature.

Energy Technology Data Exchange (ETDEWEB)

CMSX-4 superalloy laser beam welds were investigated by transmission electron microscopy and atom probe field-ion microscopy (APFIM). The weld microstructure consisted of fine (10- to 50-nm) irregularly shaped {gamma}` precipitates (0.65 to 0.75 volume fraction) within the {gamma} matrix. APFIM compositions of the {gamma} and {gamma}` phases were found to be different from those in the base metal. Concentration profiles across the {gamma} and {gamma}` phases showed extensive variations of Cr, Co and Al concentrations as a function of distance within the {gamma} phase. Calculated lattice misfits near the {gamma}/{gamma}` interface in the welds are positive values compared to the negative values for base metal. (orig.).

Energy Technology Data Exchange (ETDEWEB)

There are several on-going projects of e{sup +}e{sup -} colliders. If they are constructed, we can convert them into photon-photon ({gamma}-{gamma}) colliders by converting electron beams into {gamma} beams, irradiating laser beams just before the interaction point. In this report we discuss the technical issues on the accelerator.

International Nuclear Information System (INIS)

The properties of the triplet of low-lying states in "1"0"1Mo have been studied through spectroscopy of the #gamma# radation following thermal neutron capture in "1"0"0Mo and #beta#-decay of "1"0"1Nb and through a measurement of the proton angular distributions in the "1"0"0Mo(d, p) reaction with 14 MeV deuteron energy. The half-lives of the 13.5 keV state and the 57.0 keV 5/2"+ state have been measured as 226(7) and 133(7) ns, respectively. These values and the quadrupole/dipole mixing ratios of the 13.5 keV and 43.5 keV transitions yield spin and parity 3/2"+ for the 13.5 keV level. The E2 components in the 13.5 (3/2"+#->#1/2"+) and 43.5 keV (5/2"+#->#3/2"+) transitions are #<=# 8x10"-"4 and 54(9)%, respectively. The possibility of an additional state near to the 57.0 keV level is discussed. IBFM/PTQM calculations, taking into consideration the transitional character of the "1"0"0Mo boson core, account for the ...

CERN Document Server

We review results from general relativistic axisymmetric magnetohydrodynamic simulations of accretion in Sgr A*. We use general relativistic radiative transfer methods and to produce a broad band (from millimeter to gamma-rays) spectrum. Using a ray tracing scheme we also model images of Sgr A* and compare the size of image to the VLBI observations at 230 GHz. We perform a parameter survey and study radiative properties of the flow models for various black hole spins, ion to electron temperature ratios, and inclinations. We scale our models to reconstruct the flux and the spectral slope around 230 GHz. The combination of Monte Carlo spectral energy distribution calculations and 230 GHz image modeling constrains the parameter space of the numerical models. Our models suggest rather high black hole spin ($a_*\\approx 0.9$), electron temperatures close to the ion temperature ($T_i/T_e \\sim 3$) and high inclination angles ($i \\approx 90 \\deg$).

CERN Document Server

W and Z bosons are expected to be produced abundantly at the Large Hadron Collider (LHC). This large dataset and the high LHC energy will allow for detailed studies of their properties in a previously unexplored kinematic domain of low parton momentum fraction and high energy scale thus providing, together with the proton-proton nature of the collisions, new constraints on the parton distribution functions and precise tests of perturbative QCD. First determinations of the W -> lnu and Z -> ll (l = e,mu) production cross sections for proton-proton collisions at sqrt(s) = 7 TeV were performed using about 320/nb of data recorded by the ATLAS experiment at the LHC. The results of these measurements for W and Z bosons for proton-proton collisions at sqrt(s) = 7 TeV are presented. In addition ?rst measurements of the ratio between the W and Z/gamma*-cross sections and of the W -> lnu charge asymmetry are also discussed.

Energy Technology Data Exchange (ETDEWEB)

Using a Q3D magnetic spectrometer the elastic and inelastic scattering of /sup 12/C on /sup 88/Sr and the neutron pick-up (/sup 12/C, /sup 13/C) has been studied. The spin alignment of the inelastically excited 2/sup +/ state of /sup 12/C (4.43 MeV) has been deduced from the line shapes broadened by the ..gamma..-decay in flight. Thus for each m-substate a full angular distribution was obtained. The m = 1 substate shows a shifted interference minimum, which is explained by the different strength of the Coulomb and nuclear amplitudes in the m-substates. The analysis of the data on elastic scattering, inelastic scattering, alignment and the neutron transfer can be described consistently with one choice of the optical model parameters.

Science.gov (United States)

Summaries are presented for those research contracts which expired between December 31, 1960 and December 31, 1981. Topics covered include: factors controlling distribution of fission products in biosphere, non-destructive methods of evaluating the U/sup 235/ and Pu content of irradiated fuel elements, studies of contamination in local marine resources, tracer studies of anemia, non-destructive analysis of irradiated fuel elements using a flux integrating monitor, mechanism of proteolysis of I/sup 131/-labeled fibrinogen, radiosensitivity of spermatogonia of Drosophila melel elements by gamma scanning, uptake and loss of radioactive material by marine bacteria, factors which influence the movement of radioactive strontium from soils to plants, biological concentration of fission products in mollusks from water, decay scheme of Tl/sup 210/, calcium balance in metabolic bone disease, development of radioactive drugs ...

CERN Document Server

We present results of near--IR long-slit spectroscopy in the J and K bands of the Seyfert 2 galaxies NGC 2110 and Circinus, investigating the gaseous distribution, excitation, reddening and kinematics. In NGC 2110, the emission line ratio [FeII]/Pa beta increases towards the nucleus (to ~ 7). The nuclear [Fe II]1.257 (microns) and Pa beta lines are broader (FWHM ~ 500 km/s) than the H2 (2.121) line (FWHM ~ 300 km/s). Both these results suggest that shocks, driven by the radio jet, are an important source of excitation of [Fe II]. The H2 excitation appears to be dominated by X-rays from the nucleus. In Circinus, both [FeII]/Pa beta and H2/Br gamma decrease from ~ 2 at 4 arcsec from the nucleus to nuclear values of ~ 0.6 and ~ 1, respectively, suggesting that the starburst dominates the nuclear excitation, while the AGN dominates the excitation further out (r > 2 arcsec). For both galaxies, the gaseous kinematics are consistent with circular ...

International Nuclear Information System (INIS)

Thorium-230, together with "2"3"8U and "2"2"6Ra, was determined (mainly by #gamma#-spectrometry) in samples from the waste piles at Borst and Jazbec in the vicinity of the former uranium mine at Zirovski vrh, Slovenia. Activity (and in the case of uranium, also mass) balances for these nuclides were constructed for the overall operation of the mine and yellow cake plant, using experimental data and known data on ore and uranium production, and nuclide emissions to the environment. All the "2"2"6Ra resulting from ore exploitation is presently contained in the Borst tailings pile. However, because of the very high content of "2"3"0Th in red mud deposited at Jazbec, where 60% of this nuclide is found, the majority of "2"2"6Ra will be found at the Jazbec pile in the future, due to its ingrowth from "2"3"0Th over the next few thousand years. (Author).

Energy Technology Data Exchange (ETDEWEB)

This project was supported through ERDA to demonstrate that the temporal distribution of tritium can be documented by the analysis of bound hydrogen in annual tree-ring samples. The project focuses on two sample locations at the Savannah River Site (SRS), a nuclear material production facility located in Aiken, SC. The SRS provided samples of cross-sections from a single tree that were to be pooled together for analysis. Annual tree-rings were identified in each cross-section sample and separated for the period 1954 to 1993. These annual samples were ground and chemically treated to separate the hollocellulose fraction of the wood, then subsequently combusted and the resulting water counting using low-level liquid scintillation counting equipment. Additionally, the ground annual tree-rings were gamma-counted to determine any temporal variation in radionuclide activity and analyzed with x-ray fluorescence to find any temporal variation in ...

International Nuclear Information System (INIS)

Exploratory experiments of laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft were conducted. Microstructure of the welded seam was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive spectrometer (EDS). Mechanical properties of the welded seam were evaluated by microhardness and tensile strength testing. The corresponding mechanisms were discussed in detail. Results showed that the laser-welded seam had non-equilibrium solidified microstructures consisting of FeCr_0_._2_9Ni_0_._1_6C_0_._0_6 austenite solid solution dendrites as the dominant and some fine and dispersed Ni_3Al #gamma#' phase and Laves particles as well as little amount of MC short stick or particle-like carbides distributed in the interdendritic regions. The average microhardness of the welded seam was relatively uniform and lower than that of the base metal due to partial ...

International Nuclear Information System (INIS)

Insulitis is considered the histopathological hallmark of type I diabetes. In the non-obese diabetic (NOD) mouse, diabetes has never been observed in the absence of insulitis. The in vivo detection of insulitis could be of relevance for early prediction of diabetes. As approximately 15% of islet-infiltrating lymphocytes express interleukin 2 receptors, the authors have labelled recombinant inter-leukin 2 with "1"2"3I and used this radiopharmaceutical to detect insulitis by gamma camera imaging. The authors studied 71 prediabetic NOD and 27 normal Balb/c mice. Labelled #alpha#-lactalbumin was used as the control protein. In the first set of experiments the tissue distribution of radiolabelled interleukin 2 in isolated organs from animals sacrificed at different time points was studied. Higher radioactivity was detected in the pancreas of NOD mice injected with labelled interleukin 2, as compared to NOD mice receiving labelled ...

International Nuclear Information System (INIS)

An experimental investigation was made of the #gamma#-transitions feeding or de-exciting the 1355 keV isomeric state in "1"7"7Ta. The E2/M1 mixing ratios for the 311 keV interband transition from the isomer and for the 271 keV and the 295 keV intraband transitions within the rotational band on the isomer were determined to be delta = 0.29sup(+0.11)sub(-0.06), 0.25sup(+0.05)sub(-0.03) and 0.30sup(+0.06)sub(-0.08), respectively, employing combined measurements of the linear polarization and angular distribution of the #gamma#-ray with the aid of conversion electron measurements. Spin and parity assignments of the isomer were confirmed to be 21/2"-. The half-life of the isomer was remeasured to be Tsub(1/2) = 5.0 +- 0.2 #mu#s and the magnetic moment was found to be #mu# = 0.080 +- 0.014 #mu#sub(N). The gsub(K) and gsub(R) factors for the band on the isomer were deduced separately to be gsub(K=21/2"-) = ...

International Nuclear Information System (INIS)

Natural radioactive materials under certain conditions can reach hazardous radiological levels. The natural radionuclide ("2"3"8U, "2"3"2Th, "4"0K) contents of rock samples at various locations in the North Tushki area were investigated using gamma-spectrometric analysis. Estimates of the measured radionuclide content have been made for the absorbed dose rate of gamma radiation. The equivalent radium (R_e_q) and the external hazard index (H_e_x) which resulted from the natural radionuclides in soil are also calculated and tabulated. The studied samples have been collected from various rock exposures in the North Tushki area. The distribution of major oxides, U and Th were studied. It is found that the enrichment and depletion of the major oxides are mainly due to the effect of hydrothermal alteration, which caused mobility of some major oxides, which increases some elements and decreases others. It is important to mention ...

International Nuclear Information System (INIS)

Experiments of autogenous laser full penetration welding between dissimilar cast Ni-based superalloy K418 and alloy steel 42CrMo flat plates with 3.5 mm thickness were conducted using a 3 kW continuous wave (CW) Nd:YAG laser. The influences of laser welding velocity, flow rate of side-blow shielding gas, defocusing distance were investigated. Microstructure of the welded seam was characterized by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). Mechanical properties of the welded seam were evaluated by microhardness and tensile strength testing. Results show that high quality full penetration laser-welded joint can be obtained by optimizing the welding velocity, flow rate of shielding gas and defocusing distance. The laser-welded seam have non-equilibrium solidified microstructures consisting of #gamma#-FeCr_0_._2_9Ni_0_._1_6C_0_._0_6 austenite solid solution dendrites as the dominant ...

International Nuclear Information System (INIS)

Medical imaging using single gamma-ray-emitting radionuclides typically makes use of parallel hole collimators or pinholes in order to achieve good spatial resolution. However, a tradeoff in sensitivity is inherent in the use of a collimator, and modern preclinical single photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma rays, often less than 0.1%. A system for small animal SPECT imaging which uses no collimators could potentially achieve very high sensitivity-several tens of percent-with reasonably sized detectors. This would allow two significant improvements in preclinical studies: images could be obtained more rapidly, allowing higher throughput for screening applications, or for dynamic processes to be observed with very good time resolution; and images could be obtained with less radioactive tracer, making possible the in vivo imaging of low-capacity receptor systems, aiding research into ...

UK PubMed Central (United Kingdom)

Interleukin 12 (IL-12) activates natural killer (NK) and T cells with the secondary synthesis and release of interferon-gamma (IFN-gamma) and other cytokines. IL-12-induced organ alterations are reported...Full Text Available

International Nuclear Information System (INIS)

The radioactive decay of "2"0"3Bi is studied. A level scheme is proposed for "2"0"3Pb on the basis of #gamma#-ray and electron spectra and #gamma#-#gamma# coincidence measurements. The experimental data are compared with theoretical results obtained in a three quasiparticle approximation. (Auth.).

UK PubMed Central (United Kingdom)

The natural biotic capacity of soils to degrade gamma-hexachlorocyclohexane (gamma-HCH, lindane) was estimated using an enrichment technique based on the ability of soil bacteria to develop on synthetic...Full Text Available

CERN Document Server

The top-color assisted technicolor (TC2) mode predicts the existence of a pair of charged top-pions $\\pi^{\\pm}_t$. In this paper, we study the production of the charged top-pions pair $\\pi^{\\pm}_t$ at next generation $\\gamma\\gamma$ colliders. The results show that the production rates can reach the level of $10^2$ fb with reasonable parameter space. With a large number of events and the clean background, the charged top-pion should be observable at the $\\gamma\\gamma$ colliders. Therefore, our studies can help us to search for charged top-pion, and furthermore, to test the TC2 model.

International Nuclear Information System (INIS)

We present the efficient technique to extract the signal of the intermediate mass Higgs boson from the backgrounds at future #gamma##gamma# colliders. For a clear Higgs detection, it is important to fit the original electron accelerator energy depending on the Higgs mass, to set the polarization of the photon beams and to apply the efficient b quark tagging method. we demonstrate the extraction of information of Higgs parameters and the new physics from the observable physical quantities. It is clearly shown that a future #gamma##gamma# collider will have a rich potential for study on the new physics, as well as the Higgs physics. (author).

CERN Document Server

Heavy quark production in $\\gamma\\gamma$ collisions is analyzed within the approach to hard collisions of photons recently proposed by the author. In this approach evaluating the cross section $\\sigma(\\gamma\\gamma\\to Q\\bar{Q})$ in the ``next-to-leading order of QCD'' requires the inclusion of direct photon contributions up to the order $\\alpha^2\\alpha_s^2$, whereas in the standard approach direct photon terms only up to the order $\\alpha^2\\alpha_s$ are taken into account. Phenomenological consequences of this difference are discussed.

British Library Electronic Table of Contents (United Kingdom)

The Internet has transformed consumer behaviour, particularly the manner in which consumers search for information prior to making a purchase. However, we know relatively little about the relationship between consumer information search strategies prior to visiting a physical retail store and the amount of money spent on product purchases. This raises an important question for retailers; does the online channel pay? We test this notion in a study of 1275 consumers across the four retail categories of Clothing and Footwear, Beauty and Skincare, DIY Hardware, and Kitchen and Bathroom Renovations. We find that in all categories, except for Clothing and Footwear, consumers who used the Internet to search for product information prior to making a physical store purchase, spent more money when p...

Energy Technology Data Exchange (ETDEWEB)

We investigate the semihard production of neutral pseudoscalar and tensor mesons in high-energy [gamma][gamma] collisions (M=P=[pi][sup 0], [eta], [eta]' or M=T=a[sub 2], f[sub 2], f[sub 2]'). We deal with the exclusive [gamma][gamma][yields]MM' or semi-exclusive [gamma][gamma][yields]MX reactions (X is the hadron jet with not too large mass). The considered transfer momenta are small in comparison with the photon energies and they are large in comparison with the confinement scale. The amplitudes of these processes are determined by the odderon exchange, i.e. three-gluon exchange in the lowest order of perturbative QCD. The cross sections are calculated in this approximation. The possibility of measurements at LEP and at future [gamma][gamma] colliders is discussed. (orig.).

International Nuclear Information System (INIS)

The production of pairs of doubly charged vector bileptons is studied at future #gamma##gamma# colliders. The unpolarized cross section for the #gamma##gamma##->#Y"-"-Y"+"+ subprocess is analytically calculated and convoluted to predict the number of events in the complete e"+e"-#->##gamma##gamma##->#Y"-"-Y"+"+ process. The gauge or nongauge character of the vector bilepton Y"#+-#"#+-# is discussed. It is found that, as a consequence of its spectacular signature, as it decays dominantly into two identical charged leptons, and also due to its charge contents, which significantly enhance the cross section, the detection of this class of particles with mass in the sub-TeV region can be at the reach of these colliders. The model-independent nature of our results is stressed.

CERN Document Server

Il package software GESIS per la gestione di sistemi spettrometrici gamma

International Nuclear Information System (INIS)

The possibility of gamma-absorption identification of the analyzed substance is considered. the basic provisions of the proposed method are concentrated on the example of carbohydrates and hydrocarbons. The above method is tested experimentally on polyethylenes and polystyrene

International Nuclear Information System (INIS)

Sentinel node (SN) scintigraphy for cervical and vulvar cancer guides the gynaecological oncologist in finding the metastatic lymph nodes during lymphadenectomy. The role of the surgical gamma probe in the sentinel node concept in gynaecological oncology is to localise (SN) both intra-operatively and transcutaneously. Intra-operative hand-held collimated gamma probes are increasingly used for detection of the sentinel lymph node. A comparative evaluation of handheld gamma probes: Neoprobe 1500, Europrobe, Gamma Finder, Gamma Ray Prospector GRP1 and GPR2 was performed using different detection methods. Laboratory tests were performed in which sensitivity, spatial resolution and angular sensitivity were evaluated. The results for each gamma probe were summarised and discussed. Awareness of a gamma probes capabilities and limitations should be ...

CERN Document Server

Determination of absorbed dose in a patient irradiated by beams of x or gamma rays in radiotherapy procedures

Energy Technology Data Exchange (ETDEWEB)

Short communication.

International Nuclear Information System (INIS)

Full text: An adaptive response is a decreased biological effect induced by a priming radiation dose given prior to a challenge dose. Adaptive responses contradict the linear-nothreshold model of risk estimation. The pKZ1 mouse chromosomal inversion assay is an extremely sensitive assay for studying the mutagenic effect of low dose radiation. A non-linear dose response for chromosomal inversion has been observed in pKZ1 spleen and prostate after a single whole body irradiation with doses between 1?Gy and 10mGy. Doses between 5-10?Gy resulted in an induction in inversions and doses between 1-10mGy resulted in a reduction below endogenous inversion frequency. These results suggest that doses in the 1-10 mGy range cause host responses which overcompensate by not only preventing inversions that would normally occur as a result of the low doses of radiation but also by preventing some of the endogenous inversions that would have occurred in the absence of radiation. It ...