WorldWideScience

Sample records for density highly radiative

  1. Effect of mix proportion of high density concrete on compressive strength, density and radiation absorption

    International Nuclear Information System (INIS)

    Noor Azreen Masenwat; Mohamad Pauzi Ismail; Suhairy Sani; Ismail Mustapha; Nasharuddin Isa; Mohamad Haniza Mahmud; Mohammad Shahrizan Samsu

    2014-01-01

    To prevent radiation leaks at nuclear reactors, high-density concrete is used as an absorbent material for radiation from spreading into the environment. High-density concrete is a mixture of cement, sand, aggregate (usually high-density minerals) and water. In this research, hematite stone is used because of its mineral density higher than the granite used in conventional concrete mixing. Mix concrete in this study were divided into part 1 and part 2. In part 1, the concrete mixture is designed with the same ratio of 1: 2: 4 but differentiated in terms of water-cement ratio (0.60, 0.65, 0.70, 0.75, 0.80 ). Whereas, in part 2, the concrete mixture is designed to vary the ratio of 1: 1: 2, 1: 1.5: 3, 1: 2: 3, 1: 3: 6, 1: 2: 6 with water-cement ratio (0.7, 0.8, 0.85, 0.9). In each section, the division has also performed in a mixture of sand and fine sand hematite. Then, the physical characteristics of the density and the compressive strength of the mixture of part 1 and part 2 is measured. Comparisons were also made in terms of absorption of radiation by Cs-137 and Co-60 source for each mix. This paper describes and discusses the relationship between the concrete mixture ratio, the relationship with the water-cement ratio, compressive strength, density, different mixture of sand and fine sand hematite. (author)

  2. High Density Nano-Electrode Array for Radiation Detection

    International Nuclear Information System (INIS)

    Misra, Mano

    2010-01-01

    Bulk single crystals of Cd 1-x Zn x Te (x=0.04 to x=0.2) compound semiconductor is used for room temperature radiation detection. The production of large volume of Cd 1-x Zn x Te with low defect density is expensive. As a result there is a growing research interest in the production of nanostructured compound semiconductors such as Cd 1-x Zn x Te in an electrochemical route. In this investigation, Cd 1-x Zn x Te ternary compound semiconductor, referred as CZT, was electrodeposited in the form of nanowires onto a TiO 2 nanotubular template from propylene carbonate as the non-aqueous electrolyte, using a pulse-reverse electrodeposition process at 130 C. The template acted as a support in growing ordered nanowire of CZT which acts as a one dimensional conductor. Cyclic Voltammogram (CV) studies were conducted in determining the potentials for the growth of nanowires of uniform stoichiometry. The morphologies and composition of CZT were characterized by using SEM, TEM and XRD. The STEM mapping carried out on the nanowires showed the uniform distribution of Cd, Zn and Te elements. TEM image showed that the nanowires were polycrystalline in nature. The Mott-Schottky analysis carried on the nanowires showed that the nanowires were a p-type semiconductor. The carrier density, band gap and resistivity of the Cd 0.9 Zn 0.1 Te nanowires were 4.29 x 10 13 cm -3 , 1.56 eV and 2.76 x 10 11 (Omega)-cm respectively. The high resistivity was attributed to the presence of deep defect states such as cadmium vacancies or Te antisites which were created by the anodic cycle of the pulse-reverse electrodeposition process. Stacks of series connected CZT nanowire arrays were tested with different bias potentials. The background current was in the order of tens of picoamperes. When exposed to radiation source Amerecium-241 (60 KeV, 4 (micro)Ci), the stacked CZT nanowires arrays showed sensing behavior. The sensitivity of the nanowire arrays increased as the number of stacks increased. The

  3. High Density Nano-Electrode Array for Radiation Detection

    Energy Technology Data Exchange (ETDEWEB)

    Mano Misra

    2010-05-07

    Bulk single crystals of Cd1-xZnxTe (x=0.04 to x=0.2) compound semiconductor is used for room temperature radiation detection. The production of large volume of Cd1-xZnxTe with low defect density is expensive. As a result there is a growing research interest in the production of nanostructured compound semiconductors such as Cd1-xZnxTe in an electrochemical route. In this investigation, Cd1-xZnxTe ternary compound semiconductor, referred as CZT, was electrodeposited in the form of nanowires onto a TiO2 nanotubular template from propylene carbonate as the non-aqueous electrolyte, using a pulse-reverse electrodeposition process at 130 ºC. The template acted as a support in growing ordered nanowire of CZT which acts as a one dimensional conductor. Cyclic Voltammogram (CV) studies were conducted in determining the potentials for the growth of nanowires of uniform stoichiometry. The morphologies and composition of CZT were characterized by using SEM, TEM and XRD. The STEM mapping carried out on the nanowires showed the uniform distribution of Cd, Zn and Te elements. TEM image showed that the nanowires were polycrystalline in nature. The Mott-Schottky analysis carried on the nanowires showed that the nanowires were a p-type semiconductor. The carrier density, band gap and resistivity of the Cd0.9Zn0.1Te nanowires were 4.29x1013 cm-3, 1.56 eV and 2.76x1011Ω-cm respectively. The high resistivity was attributed to the presence of deep defect states such as cadmium vacancies or Te antisites which were created by the anodic cycle of the pulse-reverse electrodeposition process. Stacks of series connected CZT nanowire arrays were tested with different bias potentials. The background current was in the order of tens of picoamperes. When exposed to radiation source Amerecium-241 (60 KeV, 4 μCi), the stacked CZT nanowires arrays showed sensing behavior. The sensitivity of the nanowire arrays increased as the number of stacks increased. The preliminary results indicate that the

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

    Directory of Open Access Journals (Sweden)

    Casali L.

    2014-01-01

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

  5. Evaluation of the radiation resistance of high-density polyethylene

    International Nuclear Information System (INIS)

    Dougherty, D.R.; Adams, J.W.; Barletta, R.R.

    1984-03-01

    Mechanical tests following gamma irradiation and creep tests during irradiation have been conducted on high-density polyethylene (HDPE) to provide data to help assess the adequacy of this material for use in high integrity containers (HICs). Two types of HDPE, a highly cross-linked rotationally molded material and a non-cross-linked blow molded material, were used in these tests. Gamma-ray irradiations were performed at several dose rates in environments of air, Barnwell and Hanford backfill soils, and ion-exchange resins. The results of tensile and bend tests on these materials following irradiation are presented along with results on creep during irradiation. 8 references, 9 figures, 2 tables

  6. High density terahertz frequency comb produced by coherent synchrotron radiation

    Science.gov (United States)

    Tammaro, S.; Pirali, O.; Roy, P.; Lampin, J.-F.; Ducournau, G.; Cuisset, A.; Hindle, F.; Mouret, G.

    2015-07-01

    Frequency combs have enabled significant progress in frequency metrology and high-resolution spectroscopy extending the achievable resolution while increasing the signal-to-noise ratio. In its coherent mode, synchrotron radiation is accepted to provide an intense terahertz continuum covering a wide spectral range from about 0.1 to 1 THz. Using a dedicated heterodyne receiver, we reveal the purely discrete nature of this emission. A phase relationship between the light pulses leads to a powerful frequency comb spanning over one decade in frequency. The comb has a mode spacing of 846 kHz, a linewidth of about 200 Hz, a fractional precision of about 2 × 10-10 and no frequency offset. The unprecedented potential of the comb for high-resolution spectroscopy is demonstrated by the accurate determination of pure rotation transitions of acetonitrile.

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

    Energy Technology Data Exchange (ETDEWEB)

    Casali, Livia

    2015-11-24

    Fusion plasmas contain impurities, either intrinsic originating from the wall, or injected willfully with the aim of reducing power loads on machine components by converting heat flux into radiation. The understanding and the prediction of the effects of these impurities and their radiation on plasma performances is crucial in order to retain good confinement. In addition, it is important to understand the impact of pellet injection on plasma performance since this technique allows higher core densities which are required to maximise the fusion power. This thesis contributes to these efforts through both experimental investigations and modelling. Experiments were conducted at ASDEX Upgrade which has a full-W wall. Impurity seeding was applied to H-modes by injecting nitrogen and also medium-Z impurities such as Kr and Ar to assess the impact of both edge and central radiation on confinement. A database of about 25 discharges has been collected and analysed. A wide range of plasma parameters was achieved up to ITER relevant values such as high Greenwald and high radiation fractions. Transport analyses taking into account the radiation distribution reveal that edge localised radiation losses do not significantly impact confinement as long as the H-mode pedestal is sustained. N seeding induces higher pedestal pressure which is propagated to the core via profile stiffness. Central radiation must be limited and controlled to avoid confinement degradation. This requires reliable control of the impurity concentration but also possibilities to act on the ELM frequency which must be kept high enough to avoid an irreversible impurity accumulation in the centre and the consequent radiation collapse. The key role of the f{sub ELM} is confirmed also by the analysis of N+He discharges. Non-coronal effects affect the radiation of low-Z impurities at the plasma edge. Due to the radial transport, the steep temperature gradients and the ELM flush out, a local equilibrium cannot be

  8. High-Density Signal Interface Electromagnetic Radiation Prediction for Electromagnetic Compatibility Evaluation.

    Energy Technology Data Exchange (ETDEWEB)

    Halligan, Matthew

    2017-11-01

    Radiated power calculation approaches for practical scenarios of incomplete high- density interface characterization information and incomplete incident power information are presented. The suggested approaches build upon a method that characterizes power losses through the definition of power loss constant matrices. Potential radiated power estimates include using total power loss information, partial radiated power loss information, worst case analysis, and statistical bounding analysis. A method is also proposed to calculate radiated power when incident power information is not fully known for non-periodic signals at the interface. Incident data signals are modeled from a two-state Markov chain where bit state probabilities are derived. The total spectrum for windowed signals is postulated as the superposition of spectra from individual pulses in a data sequence. Statistical bounding methods are proposed as a basis for the radiated power calculation due to the statistical calculation complexity to find a radiated power probability density function.

  9. High Density Radiation Shielding Concretes for Hot Cells of 99mTc Project

    International Nuclear Information System (INIS)

    Sakr, K.

    2006-01-01

    High density concrete [more than 3.6 ton/m 3 (3.6x10 3 kg/m 3 )] was prepared to be used as a radiation shielding concrete (RSC) for hot-cells in gel technetium project at inshas to attenuate gamma radiation emitted from radioactive sources. different types of concrete were prepared by mixing local mineral aggregates mainly gravel and ilmenite . iron shots were added to the concrete mixture proportion as partial replacement of heavy aggregates to increase its density. the physical properties of prepared concrete in both plastic and hardened phases were investigated. compressive strength and radiation attenuation of gamma rays were determined. Results showed that ilmenite concrete mixed with iron shots had the highest density suitable to be use as RSC according to the chinese hot cell design requirements. Recommendations to avoid some technical problems of manufacturing radiation shielding concrete were maintained

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    International Nuclear Information System (INIS)

    Crowley, B.J.B.

    1983-01-01

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

  12. Gamma radiation effects on the rheological properties of high and low density polyethylenes

    International Nuclear Information System (INIS)

    Rangel-Nafaile, C.; Garcia-Rejon, A.; Garcia Leon, A.

    1986-01-01

    High energy radiation of polymeric materials is a topic of considerable interest from commercial and scientific points of view. Within an inert atmosphere, irradiation of polyethylene yields a crosslinking effect with a consequent improvement in its mechanical properties in comparison to the virgin materials. Additionally, if irradiated specimens are melted and recrystallized, the radiation-induced crosslinking hinders their crystalline growth altering dramatically their flow properties such as the elasticity. This work portrays the effects of the gamma radiation on the rheological properties of high and low density polyethylenes manufactured by PEMEX and analyzes the implications of theoretical results derived from the Acierno's model when it is implemented with the rheological properties of high energy irradiated polyethylenes. (author)

  13. Study and application of high-density concrete in radiation-shielding experiment

    International Nuclear Information System (INIS)

    Wu Chongming; Ding Dexin; Xiao Xuefu; Wang Shaolin; Lin Xingjun; Shen Yuanyuan

    2008-01-01

    According to the demand for research and construction project, a series of systematic experiments and studies on shielding γ-ray radiation concrete with the density of 4.60 t/m 3 were made in such aspects as mix ratio design, construction technology, uniformly shielding etc. Such issues as uniformity in the construction and compactness were solved. The ray test method for uniformly shielding concrete was presented and some technical steps for this high-density concrete used in the process of test design or construction were summed up. A series of tests and practical applications show that this technology of mix ratio design and construction is feasible. (authors)

  14. Highly biocompatible, nanocrystalline hydroxyapatite synthesized in a solvothermal process driven by high energy density microwave radiation

    Science.gov (United States)

    Smolen, Dariusz; Chudoba, Tadeusz; Malka, Iwona; Kedzierska, Aleksandra; Lojkowski, Witold; Swieszkowski, Wojciech; Kurzydlowski, Krzysztof Jan; Kolodziejczyk-Mierzynska, Małgorzata; Lewandowska-Szumiel, Małgorzata

    2013-01-01

    A microwave, solvothermal synthesis of highly biocompatible hydroxyapatite (HAp) nanopowder was developed. The process was conducted in a microwave radiation field having a high energy density of 5 W/mL and over a time less than 2 minutes. The sample measurements included: powder X-ray diffraction, density, specific surface area, and chemical composition. The morphology and structure were investigated by scanning electron microscopy as well as transmission electron microscopy (TEM). The thermal behavior analysis was conducted using a simultaneous thermal analysis technique coupled with quadruple mass spectrometry. Additionally, Fourier transform infrared spectroscopy tests of heated samples were performed. A degradation test and a biocompatibility study in vitro using human osteoblast cells were also conducted. The developed method enables the synthesis of pure, fully crystalline hexagonal HAp nanopowder with a specific surface area close to 240 m2/g and a Ca/P molar ratio equal to 1.57. TEM measurements showed that this method results in particles with an average grain size below 6 nm. A 28-day degradation test conducted according to the ISO standard indicated a 22% loss of initial weight and a calcium ion concentration at 200 μmol/dm3 in the tris(hydroxymethyl)aminomethane hydrochloride test solution. The cytocompatibility of the obtained material was confirmed in a culture of human bone derived cells, both in an indirect test using the material extract, and in direct contact. A quantitative analysis was based on the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide. Viability assay as well as on DNA content measurements in the PicoGreen test. Indirect observations were performed at one point in time according to the ISO standard for in vitro cytotoxicity (ie, after 24 hours of cell exposure to the extracts). The direct contact tests were completed at three time points: after 24 hours, on day 7, and on day 14 of a culture in an osteogenic

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  16. High-resolution Tangential AXUV Arrays for Radiated Power Density Measurements on NSTX-U

    Energy Technology Data Exchange (ETDEWEB)

    Delgado-Aparicio, L [PPPL; Bell, R E [PPPL; Faust, I [MIT; Tritz, K [The Johns Hopkins University, Baltimore, MD, 21209, USA; Diallo, A [PPPL; Gerhardt, S P [PPPL; Kozub, T A [PPPL; LeBlanc, B P [PPPL; Stratton, B C [PPPL

    2014-07-01

    Precise measurements of the local radiated power density and total radiated power are a matter of the uttermost importance for understanding the onset of impurity-induced instabilities and the study of particle and heat transport. Accounting of power balance is also needed for the understanding the physics of various divertor con gurations for present and future high-power fusion devices. Poloidal asymmetries in the impurity density can result from high Mach numbers and can impact the assessment of their flux-surface-average and hence vary the estimates of P[sub]rad (r, t) and (Z[sub]eff); the latter is used in the calculation of the neoclassical conductivity and the interpretation of non-inductive and inductive current fractions. To this end, the bolometric diagnostic in NSTX-U will be upgraded, enhancing the midplane coverage and radial resolution with two tangential views, and adding a new set of poloidally-viewing arrays to measure the 2D radiation distribution. These systems are designed to contribute to the near- and long-term highest priority research goals for NSTX-U which will integrate non-inductive operation at reduced collisionality, with high-pressure, long energy-confinement-times and a divertor solution with metal walls.

  17. Highly biocompatible, nanocrystalline hydroxyapatite synthesized in a solvothermal process driven by high energy density microwave radiation

    Directory of Open Access Journals (Sweden)

    Smolen D

    2013-02-01

    Full Text Available Dariusz Smolen1, Tadeusz Chudoba1, Iwona Malka1, Aleksandra Kedzierska1, Witold Lojkowski1, Wojciech Swieszkowski2, Krzysztof Jan Kurzydlowski2, Malgorzata Kolodziejczyk-Mierzynska3, Malgorzata Lewandowska-Szumiel31Polish Academy of Science, Institute of High Pressure Physics, Warsaw, Poland; 2Faculty of Materials Engineering, Warsaw University of Technology, Warsaw, Poland; 3Department of Histology and Embryology, Center of Biostructure Research, Medical University of Warsaw, Warsaw, PolandAbstract: A microwave, solvothermal synthesis of highly biocompatible hydroxyapatite (HAp nanopowder was developed. The process was conducted in a microwave radiation field having a high energy density of 5 W/mL and over a time less than 2 minutes. The sample measurements included: powder X-ray diffraction, density, specific surface area, and chemical composition. The morphology and structure were investigated by scanning electron microscopy as well as transmission electron microscopy (TEM. The thermal behavior analysis was conducted using a simultaneous thermal analysis technique coupled with quadruple mass spectrometry. Additionally, Fourier transform infrared spectroscopy tests of heated samples were performed. A degradation test and a biocompatibility study in vitro using human osteoblast cells were also conducted. The developed method enables the synthesis of pure, fully crystalline hexagonal HAp nanopowder with a specific surface area close to 240 m2/g and a Ca/P molar ratio equal to 1.57. TEM measurements showed that this method results in particles with an average grain size below 6 nm. A 28-day degradation test conducted according to the ISO standard indicated a 22% loss of initial weight and a calcium ion concentration at 200 µmol/dm3 in the tris(hydroxymethylaminomethane hydrochloride test solution. The cytocompatibility of the obtained material was confirmed in a culture of human bone derived cells, both in an indirect test using the material

  18. Effects of Radiation and a High Iron Load on Bone Mineral Density

    Science.gov (United States)

    Yuen, E.; Morgan, J. L. L.; Zwart, S. R.; Gonzales, E.; Camp, K.; Smith, S. M.; Bloomfield, S. A.

    2012-01-01

    Astronauts on long duration space flight missions to the moon or mars are exposed to radiation and have increase iron (Fe) stores, both of which can independently induce oxidative stress and may exacerbate bone mass loss and strength. We hypothesize a high Fe diet and a fractionated gamma radiation exposure would increase oxidative stress and lower bone mass. Three mo-old, SD rats (n=32) were randomized to receive an adequate Fe diet (45 mg Fe/kg diet) or a high Fe diet (650 mg Fe/kg diet) for 4 wks and either a cumulative 3 Gy dose (fractionated 8 x 0.375 Gy) of gamma radiation (Cs-137) or sham exposure starting on day 14. Elisa kit assessed serum catalase, clinical analyzer assessed serum Fe status and ex vivo pQCT scans measured bone parameters in the proximal/midshaft tibia and femoral neck. Mechanical strength was assessed by 3-pt bending and femoral neck test. There is a significant decrease in trabecular bone mineral density (BMD) from radiation (p less than 0.05) and a trend in diet (p=0.05) at the proximal tibia. There is a significant interaction in cortical BMD from the combined treatments at the midshaft tibia (p less than 0.05). There is a trending decrease in total BMD from diet (p=0.07) at the femoral neck. In addition, high serum Fe was correlated to low trabecular BMD (p less than 0.05) and high serum catalase was correlated to low BMD at all 3 bone sites (p less than 0.05). There was no difference in the max load of the tibia or femoral neck. Radiation and a high iron diet increases iron status and catalase in the serum and decreases BMD.

  19. Microsystem for remote sensing of high energy radiation with associated extremely low photon flux densities

    Science.gov (United States)

    Otten, A.; Jain, V. K.

    2015-08-01

    This paper presents a microsystem for remote sensing of high energy radiation in extremely low flux density conditions. With wide deployment in mind, potential applications range from nuclear non-proliferation, to hospital radiation-safety. The daunting challenge is the low level of photon flux densities - emerging from a Scintillation Crystal (SC) on to a ~1 mm-square detector, which are a factor of 10000 or so lower than those acceptable to recently reported photonic chips (including `single-photon detection' chips), due to a combination of low Lux, small detector size, and short duration SC output pulses - on the order of 1 μs. These challenges are attempted to be overcome by the design of an innovative `System on a Chip' type microchip, with high detector sensitivity, and effective coupling from the SC to the photodetector. The microchip houses a tiny n+ diff p-epi photodiode (PD) as well as the associated analog amplification and other related circuitry, all fabricated in 0.5micron, 3-metal 2-poly CMOS technology. The amplification, together with pulse-shaping of the photocurrent-induced voltage signal, is achieved through a tandem of two capacitively coupled, double-cascode amplifiers. Included in the paper are theoretical estimates and experimental results.

  20. Ultra-High Density Electron Beams for Beam Radiation and Beam Plasma Interaction

    CERN Document Server

    Anderson, Scott; Frigola, Pedro; Gibson, David J; Hartemann, Fred V; Jacob, Jeremy S; Lim, Jae; Musumeci, Pietro; Rosenzweig, James E; Travish, Gil; Tremaine, Aaron M

    2005-01-01

    Current and future applications of high brightness electron beams, which include advanced accelerators such as the plasma wake-field accelerator (PWFA) and beam-radiation interactions such as inverse-Compton scattering (ICS), require both transverse and longitudinal beam sizes on the order of tens of microns. Ultra-high density beams may be produced at moderate energy (50 MeV) by compression and subsequent strong focusing of low emittance, photoinjector sources. We describe the implementation of this method used at LLNL's PLEIADES ICS x-ray source in which the photoinjector-generated beam has been compressed to 300 fsec duration using the velocity bunching technique and focused to 20 μm rms size using an extremely high gradient, permanent magnet quadrupole (PMQ) focusing system.

  1. Final Report. Hydrodynamics by high-energy-density plasma flow and hydrodynamics and radiative hydrodynamics with astrophysical application

    International Nuclear Information System (INIS)

    R Paul Drake

    2004-01-01

    OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves

  2. Characterization of radiation-cross-linked, high-density polyethylene for thermal energy storage

    International Nuclear Information System (INIS)

    Whitaker, R.B.; Craven, S.M.; Etter, D.E.; Jendrek, E.F.; Nease, A.B.

    1983-01-01

    Electron beam cross-linked high-density polyethylene (HDPE) pellets (DuPont Alathon, 0.93 MI) have been characterized for potential utility in thermal energy storage applications, before and after up to 500 melt-freeze cycles in ethylene glycol. Up to 95% of the HDPE's initial DSC differential scanning calorimetry Δ H/sub f/ value (44.7 cal/g) (at 1.25 0 C/min cooling rates) was retained up to 9.0 Mrad radiation dosage. Form-stability after 500 melt-freeze cycles was very good at this dosage level. X-ray diffraction measurements showed little difference between irradiated HDPE's and the unirradiated control, indicating that cross-linking occurred primarily in the amorphous regions. FTIR spectroscopy showed the pellets to be uniformly reacted. The ratios of the 965-cm -1 absorption band (trans RCH=CRH') to the 909-cm -1 band (RCH=CH 2 ) increased with increasing radiation dosage, up to 18 Mrad. Gel contents reached a maximum of 75% at the 13.5 Mrad dosage, indicating that other reactions, in addition to cross-linking, occurred at the highest (18 Mrad) dosage level. 15 references, 5 figures, 4 tables

  3. Radiation-assisted grafting of vinylidene chloride onto high-density polyethylene

    Science.gov (United States)

    Nagesh, N.; Dokhale, P. A.; Bhoraskar, V. N.

    1999-06-01

    6 MeV electrons and Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays were used for grafting vinylidene chloride (VDC) onto high-density polyethylene (HDPE) samples. The HDPE samples were immersed in vinylidene chloride and irradiated either with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays or with 6 MeV electrons. In both cases, the radiation dose was varied in the range 1.25-7.5 kGy. The grafted samples were characterized by IR spectroscopy to obtain information about the chemical bonds and with the 14 MeV neutron activation analysis technique for estimating the number of chlorine atoms. The formation of stable bonds between the VDC molecules and the polymer chains could be achieved either with 6 MeV electrons or with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays. Both the number of chlorine atoms and the sample-surface conductivity increased with the radiation dose but the increases achieved with 6 MeV electrons were greater than those achieved with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays.

  4. High-radiation zone design of the FMIT high-density beam transport

    International Nuclear Information System (INIS)

    Creek, K.O.; Liska, D.J.; King, J.D.; Cole, T.R.; Cimabue, A.G.; Robeson, L.P.; Harvey, A.

    1981-03-01

    The Fusion Materials Irradiation Test (FMIT) deuteron linac, operating at 35 MeV and 100 mA continuous duty, is expected to spill 3 μA/m and to lose 10 μA at specific bending-magnet positions. The major impact of this spill will be felt in the High-Energy Beam Transport (HEBT), where many beam-line components must be maintained. A modular design concept, that uses segmented termination panels remotely located from the modules, is being employed. Radiation-hardened quadrupoles can be opened, clam-shell fashion, to release the water-cooled beam tube r replacement if there is beam damage or lithium contamination from the target. Termination panels contain electrical, water, and instrumentation fittings to service the module, and are positioned to allow room for neutron-absorbing shielding between the beamline and the panel. The modular construction allows laboratory prealignment and check-out of all components on a structural carriage and is adaptable to supporting gamma shields. Proper choice of beam tube materials is essential for controlling activation caused by beam spill

  5. Power spectral density and scaling exponent of high frequency global solar radiation sequences

    Science.gov (United States)

    Calif, Rudy; Schmitt, François G.; Huang, Yongxiang

    2013-04-01

    The part of the solar power production from photovlotaïcs systems is constantly increasing in the electric grids. Solar energy converter devices such as photovoltaic cells are very sensitive to instantaneous solar radiation fluctuations. Thus rapid variation of solar radiation due to changes in the local meteorological condition can induce large amplitude fluctuations of the produced electrical power and reduce the overall efficiency of the system. When large amount of photovoltaic electricity is send into a weak or small electricity network such as island network, the electric grid security can be in jeopardy due to these power fluctuations. The integration of this energy in the electrical network remains a major challenge, due to the high variability of solar radiation in time and space. To palliate these difficulties, it is essential to identify the characteristic of these fluctuations in order to anticipate the eventuality of power shortage or power surge. The objective of this study is to present an approach based on Empirical Mode Decomposition (EMD) and Hilbert-Huang Transform (HHT) to highlight the scaling properties of global solar irradiance data G(t). The scale of invariance is detected on this dataset using the Empirical Mode Decomposition in association with arbitrary-order Hilbert spectral analysis, a generalization of (HHT) or Hilbert Spectral Analysis (HSA). The first step is the EMD, consists in decomposing the normalized global solar radiation data G'(t) into several Intrinsic Mode Functions (IMF) Ci(t) without giving an a priori basis. Consequently, the normalized original solar radiation sequence G'(t) can be written as a sum of Ci(t) with a residual rn. From all IMF modes, a joint PDF P(f,A) of locally and instantaneous frequency f and amplitude A, is estimated. To characterize the scaling behavior in amplitude-frequency space, an arbitrary-order Hilbert marginal spectrum is defined to: Iq(f) = 0 P (f,A)A dA (1) with q × 0 In case of scale

  6. Applications of Robust, Radiation Hard AlGaN Optoelectronic Devices in Space Exploration and High Energy Density Physics

    Energy Technology Data Exchange (ETDEWEB)

    Sun, K.

    2011-05-04

    This slide show presents: space exploration applications; high energy density physics applications; UV LED and photodiode radiation hardness; UV LED and photodiode space qualification; UV LED AC charge management; and UV LED satellite payload instruments. A UV LED satellite will be launched 2nd half 2012.

  7. High Confinement and High Density with Stationary Plasma Energy and Strong Edge Radiation Cooling in Textor-94

    Science.gov (United States)

    Messiaen, A. M.

    1996-11-01

    A new discharge regime has been observed on the pumped limiter tokamak TEXTOR-94 in the presence of strong radiation cooling and for different scenarii of additional hearing. The radiated power fraction (up to 90%) is feedback controlled by the amount of Ne seeded in the edge. This regime meets many of the necessary conditions for a future fusion reactor. Energy confinement increases with increasing densities (reminiscent of the Z-mode obtained at ISX-B) and as good as ELM-free H-mode confinement (enhancement factor verus ITERH93-P up to 1.2) is obtained at high densities (up to 1.2 times the Greenwald limit) with peaked density profiles showing a peaking factor of about 2 and central density values around 10^14cm-3. In experiments where the energy content of the discharges is kept constant with an energy feedback loop acting on the amount of ICRH power, stable and stationary discharges are obtained for intervals of more than 5s, i.e. 100 times the energy confinement time or about equal to the skin resistive time, even with the cylindrical q_α as low as 2.8 β-values up to the β-limits of TEXTOR-94 are achieved (i.e. β n ≈ 2 of and β p ≈ 1.5) and the figure of merit for ignition margin f_Hqa in these discharges can be as high as 0.7. No detrimental effects of the seeded impurity on the reactivity of the plasma are observed. He removal in these discharges has also been investigated. [1] Laboratoire de Physique des Plasmas-Laboratorium voor Plasmafysica, Association "EURATOM-Belgian State", Ecole Royale Militaire-Koninklijke Militaire School, Brussels, Belgium [2] Institut für Plasmaphysik, Forschungszentrum Jülich, GmbH, Association "EURATOM-KFA", Jülich, Germany [3] Fusion Energy Research Program, Mechanical Engineering Division, University of California at San Diego, La Jolla, USA [4] FOM Institüt voor Plasmafysica Rijnhuizen, Associatie "FOM-EURATOM", Nieuwegein, The Netherlands [*] Researcher at NFSR, Belgium itemize

  8. Alpha slow-moving high-density-lipoprotein subfraction in serum of a patient with radiation enteritis and peritoneal carcinosis

    International Nuclear Information System (INIS)

    Peynet, J.; Legrand, A.; Messing, B.; Thuillier, F.; Rousselet, F.

    1989-01-01

    An alpha slow-moving high-density-lipoprotein (HDL) subfraction was seen in a patient presenting with radiation enteritis and peritoneal carcinosis, who was given long-term cyclic parenteral nutrition. This subfraction, observed in addition to normal HDL, was precipitated with low-density lipoproteins (LDL) and very-low-density lipoproteins (VLDL) by sodium phosphotungstate-magnesium chloride. The patient's serum lipoproteins were analyzed after fractionation by density gradient ultracentrifugation. The alpha slow-moving HDL floated in the ultracentrifugation subfractions with densities ranging from 1.028 to 1.084 kg/L, and their main apolipoproteins included apolipoprotein E in addition to apolipoprotein A-I. These HDL were larger than HDL2. The pathogenesis of this unusual HDL subfraction is hypothesized

  9. Cylindrical implosion to measure the radiative properties of high density and temperature plasmas

    International Nuclear Information System (INIS)

    Xu Yan; Rose, S.J.

    2000-01-01

    Cylindrical implosion is of great interest because of its excellent diagnostic access. The authors present one-dimensional numerical simulations to explore the plasma conditions that may be achieved. Combined with the numerical data, the development of Rayleigh-Taylor instabilities and Richtmyer-Meshkov instabilities in those targets are estimated. The authors found that it is possible to achieve a high density and temperature plasma with a relatively low temperature and density gradient using a cylindrical implosion directly-driven by a high-power laser

  10. Radiation-Induced Grafting with One-Step Process of Waste Polyurethane onto High-Density Polyethylene

    Directory of Open Access Journals (Sweden)

    Jong-Seok Park

    2015-12-01

    Full Text Available The recycling of waste polyurethane (PU using radiation-induced grafting was investigated. The grafting of waste PU onto a high-density polyethylene (HDPE matrix was carried out using a radiation technique with maleic anhydride (MAH. HDPE pellets and PU powders were immersed in a MAH-acetone solution. Finally, the prepared mixtures were irradiated with an electron beam accelerator. The grafted composites were characterized by Fourier transformed infrared spectroscopy (FT-IR, surface morphology, and mechanical properties. To make a good composite, the improvement in compatibility between HDPE and PU is an important factor. Radiation-induced grafting increased interfacial adhesion between the PU domain and the HDPE matrix. When the absorbed dose was 75 kGy, the surface morphology of the irradiated PU/HDPE composite was nearly a smooth and single phase, and the elongation at break increased by approximately three times compared with that of non-irradiated PU/HDPE composite.

  11. Effect of ultraviolet radiation in the photo-oxidation of High Density Polyethylene and Biodegradable Polyethylene films

    International Nuclear Information System (INIS)

    Martínez-Romo, A; Mota, R González; Bernal, J J Soto; Candelas, I Rosales; Reyes, C Frausto

    2015-01-01

    One of the most widely used plastics in the world is the High density polyethylene (HDPE), it is a stable material due to its carbon-carbon bonds, causing their slow degradation; which is why we are looking for alternative ways to accelerate the degradation process of this polymer. An alternative is the addition of oxidized groups in its molecular structure, which results in the development of polymers susceptible to biodegradation (PE-BIO). In this paper, HDPE and PE-BIO films were exposed to UV-B radiation (320-280 nm) at different exposure times, 0-60 days. The effects of UV radiation in samples of HDPE and PE-BIO were characterized using infrared spectroscopy with attenuated total reflectance (ATR). The results show that the exposed materials undergo changes in their molecular structure, due to the infrared bands formed which corresponds to the photo-oxidation of HDPE and PE films when submitted to UV-B radiation

  12. High-Density and Very-Low-Density Lipoprotein Have Opposing Roles in Regulating Tumor-Initiating Cells and Sensitivity to Radiation in Inflammatory Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, Adam R. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Atkinson, Rachel L. [Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Reddy, Jay P. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Debeb, Bisrat G.; Larson, Richard; Li, Li [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Masuda, Hiroko; Brewer, Takae [Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Atkinson, Bradley J. [Department of Clinical Pharmacy Services, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Brewster, Abeena [Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A., E-mail: wwoodward@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-04-01

    Purpose: We previously demonstrated that cholesterol-lowering agents regulate radiation sensitivity of inflammatory breast cancer (IBC) cell lines in vitro and are associated with less radiation resistance among IBC patients who undergo postmastectomy radiation. We hypothesized that decreasing IBC cellular cholesterol induced by treatment with lipoproteins would increase radiation sensitivity. Here, we examined the impact of specific transporters of cholesterol (ie lipoproteins) on the responses of IBC cells to self-renewal and to radiation in vitro and on clinical outcomes in IBC patients. Methods and Materials: Two patient-derived IBC cell lines, SUM 149 and KPL4, were incubated with low-density lipoproteins (LDL), very-low-density lipoproteins (VLDL), or high-density lipoproteins (HDL) for 24 hours prior to irradiation (0-6 Gy) and mammosphere formation assay. Cholesterol panels were examined in a cohort of patients with primary IBC diagnosed between 1995 and 2011 at MD Anderson Cancer Center. Lipoprotein levels were then correlated to patient outcome, using the log rank statistical model, and examined in multivariate analysis using Cox regression. Results: VLDL increased and HDL decreased mammosphere formation compared to untreated SUM 149 and KPL4 cells. Survival curves showed enhancement of survival in both of the IBC cell lines when pretreated with VLDL and, conversely, radiation sensitization in all cell lines when pretreated with HDL. In IBC patients, higher VLDL values (>30 mg/dL) predicted a lower 5-year overall survival rate than normal values (hazard ratio [HR] = 1.9 [95% confidence interval [CI]: 1.05-3.45], P=.035). Lower-than-normal patient HDL values (<60 mg/dL) predicted a lower 5-year overall survival rate than values higher than 60 mg/dL (HR = 3.21 [95% CI: 1.25-8.27], P=.015). Conclusions: This study discovered a relationship among the plasma levels of lipoproteins, overall patient response, and radiation resistance in IBC patients

  13. High-Density and Very-Low-Density Lipoprotein Have Opposing Roles in Regulating Tumor-Initiating Cells and Sensitivity to Radiation in Inflammatory Breast Cancer

    International Nuclear Information System (INIS)

    Wolfe, Adam R.; Atkinson, Rachel L.; Reddy, Jay P.; Debeb, Bisrat G.; Larson, Richard; Li, Li; Masuda, Hiroko; Brewer, Takae; Atkinson, Bradley J.; Brewster, Abeena; Ueno, Naoto T.; Woodward, Wendy A.

    2015-01-01

    Purpose: We previously demonstrated that cholesterol-lowering agents regulate radiation sensitivity of inflammatory breast cancer (IBC) cell lines in vitro and are associated with less radiation resistance among IBC patients who undergo postmastectomy radiation. We hypothesized that decreasing IBC cellular cholesterol induced by treatment with lipoproteins would increase radiation sensitivity. Here, we examined the impact of specific transporters of cholesterol (ie lipoproteins) on the responses of IBC cells to self-renewal and to radiation in vitro and on clinical outcomes in IBC patients. Methods and Materials: Two patient-derived IBC cell lines, SUM 149 and KPL4, were incubated with low-density lipoproteins (LDL), very-low-density lipoproteins (VLDL), or high-density lipoproteins (HDL) for 24 hours prior to irradiation (0-6 Gy) and mammosphere formation assay. Cholesterol panels were examined in a cohort of patients with primary IBC diagnosed between 1995 and 2011 at MD Anderson Cancer Center. Lipoprotein levels were then correlated to patient outcome, using the log rank statistical model, and examined in multivariate analysis using Cox regression. Results: VLDL increased and HDL decreased mammosphere formation compared to untreated SUM 149 and KPL4 cells. Survival curves showed enhancement of survival in both of the IBC cell lines when pretreated with VLDL and, conversely, radiation sensitization in all cell lines when pretreated with HDL. In IBC patients, higher VLDL values (>30 mg/dL) predicted a lower 5-year overall survival rate than normal values (hazard ratio [HR] = 1.9 [95% confidence interval [CI]: 1.05-3.45], P=.035). Lower-than-normal patient HDL values (<60 mg/dL) predicted a lower 5-year overall survival rate than values higher than 60 mg/dL (HR = 3.21 [95% CI: 1.25-8.27], P=.015). Conclusions: This study discovered a relationship among the plasma levels of lipoproteins, overall patient response, and radiation resistance in IBC patients

  14. Radiative recombination process of high density excitons in CdS crystals

    Energy Technology Data Exchange (ETDEWEB)

    Dneprovskij, V.S.; Klimov, V.I.; Martynenko, E.D.; Stadnik, V.A.

    1983-11-01

    The behaviour of the P-, E-, L- and Q-lines of luminescence in CdS is compared with calculated results for the processes of exciton-exciton scattering, exciton-electron scattering, annihilation of equilibrium electron-hole fluid (EHF), annihilation of electron-hole plasma (processes of amplification and reabsorption are taken into account). The comparison permitted to determine parameters of high density exciton gas and EHF. Spectral-kinetic properties of generation are investigated, and amplification factor in CdS is estimated.

  15. Preparation of High Density Polyethylene/Waste Polyurethane Blends Compatibilized with Polyethylene-Graft-Maleic Anhydride by Radiation

    Directory of Open Access Journals (Sweden)

    Jong-Seok Park

    2015-04-01

    Full Text Available Polyurethane (PU is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, PU recycling has received significant attention due to environmental issues. In this study, we developed a recycling method for waste PU that utilizes the radiation grafting technique. Grafting of waste PU was carried out using a radiation technique with polyethylene-graft-maleic anhydride (PE-g-MA. The PE-g-MA-grafted PU/high density polyethylene (HDPE composite was prepared by melt-blending at various concentrations (0–10 phr of PE-g-MA-grafted PU. The composites were characterized using fourier transform infrared spectroscopy (FT-IR, and their surface morphology and thermal/mechanical properties are reported. For 1 phr PU, the PU could be easily introduced to the HDPE during the melt processing in the blender after the radiation-induced grafting of PU with PE-g-MA. PE-g-MA was easily reacted with PU according to the increasing radiation dose and was located at the interface between the PU and the HDPE during the melt processing in the blender, which improved the interfacial interactions and the mechanical properties of the resultant composites. However, the elongation at break for a PU content >2 phr was drastically decreased.

  16. The effect of gamma radiation on hardness evolution in high density polyethylene at elevated temperatures

    International Nuclear Information System (INIS)

    Chen, Pei-Yun; Chen, C.C.; Harmon, Julie P.; Lee, Sanboh

    2014-01-01

    This research focuses on characterizing hardness evolution in irradiated high density polyethylene (HDPE) at elevated temperatures. Hardness increases with increasing gamma ray dose, annealing temperature and annealing time. The hardness change is attributed to the variation of defects in microstructure and molecular structure. The kinetics of defects that control the hardness are assumed to follow the first order structure relaxation. The experimental data are in good agreement with the predicted model. The rate constant follows the Arrhenius equation, and the corresponding activation energy decreases with increasing dose. The defects that control hardness in post-annealed HDPE increase with increasing dose and annealing temperature. The structure relaxation of HDPE has a lower energy of mixing in crystalline regions than in amorphous regions. Further, the energy of mixing for defects that influence hardness in HDPE is lower than those observed in polycarbonate (PC), poly(methyl methacrylate) (PMMA) and poly (hydroxyethyl methacrylate) (HEMA). This is due to the fact that polyethylene is a semi-crystalline material, while PC, PMMA and PHEMA are amorphous. - Highlights: • Hardness of HDPE increases with increasing gamma ray dose, annealing time and temperature. • The hardness change arises from defects in microstructure and molecular structure. • Defects affecting hardness follow a kinetics of structure relaxation. • The structure relaxation has a low energy of mixing in crystalline regime

  17. The effect of gamma radiation on hardness evolution in high density polyethylene at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Pei-Yun [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); Chen, C.C. [Institute of Nuclear Energy Research, Longtan, Taoyuan 325, Taiwan (China); Harmon, Julie P. [Department of Chemistry, University of South Florida, Tampa, FL 33620 (United States); Lee, Sanboh, E-mail: sblee@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China)

    2014-08-01

    This research focuses on characterizing hardness evolution in irradiated high density polyethylene (HDPE) at elevated temperatures. Hardness increases with increasing gamma ray dose, annealing temperature and annealing time. The hardness change is attributed to the variation of defects in microstructure and molecular structure. The kinetics of defects that control the hardness are assumed to follow the first order structure relaxation. The experimental data are in good agreement with the predicted model. The rate constant follows the Arrhenius equation, and the corresponding activation energy decreases with increasing dose. The defects that control hardness in post-annealed HDPE increase with increasing dose and annealing temperature. The structure relaxation of HDPE has a lower energy of mixing in crystalline regions than in amorphous regions. Further, the energy of mixing for defects that influence hardness in HDPE is lower than those observed in polycarbonate (PC), poly(methyl methacrylate) (PMMA) and poly (hydroxyethyl methacrylate) (HEMA). This is due to the fact that polyethylene is a semi-crystalline material, while PC, PMMA and PHEMA are amorphous. - Highlights: • Hardness of HDPE increases with increasing gamma ray dose, annealing time and temperature. • The hardness change arises from defects in microstructure and molecular structure. • Defects affecting hardness follow a kinetics of structure relaxation. • The structure relaxation has a low energy of mixing in crystalline regime.

  18. High Energy Density Laboratory Astrophysics

    CERN Document Server

    Lebedev, Sergey V

    2007-01-01

    During the past decade, research teams around the world have developed astrophysics-relevant research utilizing high energy-density facilities such as intense lasers and z-pinches. Every two years, at the International conference on High Energy Density Laboratory Astrophysics, scientists interested in this emerging field discuss the progress in topics covering: - Stellar evolution, stellar envelopes, opacities, radiation transport - Planetary Interiors, high-pressure EOS, dense plasma atomic physics - Supernovae, gamma-ray bursts, exploding systems, strong shocks, turbulent mixing - Supernova remnants, shock processing, radiative shocks - Astrophysical jets, high-Mach-number flows, magnetized radiative jets, magnetic reconnection - Compact object accretion disks, x-ray photoionized plasmas - Ultrastrong fields, particle acceleration, collisionless shocks. These proceedings cover many of the invited and contributed papers presented at the 6th International Conference on High Energy Density Laboratory Astrophys...

  19. MiR-33a Decreases High-Density Lipoprotein-Induced Radiation Sensitivity in Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, Adam R.; Bambhroliya, Arvind [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Reddy, Jay P. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Debeb, Bisrat G. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Huo, Lei [Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Larson, Richard; Li, Li [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A., E-mail: wwoodward@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-06-01

    Purpose: We previously showed that high-density lipoprotein (HDL) radiosensitizes inflammatory breast cancer (IBC) cells in vitro and is associated with better local control after radiation therapy in IBC patients. The microRNA miR-33 family negatively regulates the adenosine triphosphate binding cassette transporter subfamily A member 1. We hypothesized that variations in miR-33a expression in IBC cancer cells versus non-IBC cells would correlate with radiation sensitivity following exposure to HDL in vitro. Methods and Materials: MiR-33a expression was analyzed by reverse transcriptase–polymerase chain reaction in 4 cell lines representing common clinical breast cancer subtypes. Overexpression and knockdown of miR-33a was demonstrated via transfection of an miR-33a mimic or an anti-miR-33a construct in high- and low-expressing miR-33a cell lines. Clonogenic survival in vitro in these cells was quantified at baseline and following HDL treatment. MiR-33a expression on distant relapse-free survival (DRFS) of 210 cases downloaded from the Oxford breast cancer dataset was determined. Results: Expression levels of miR-33a were lower in IBC cell lines and IBC tumor samples than in non-IBC cell lines and normal breast tissue. Cholesterol concentrations in the cell membranes were higher in IBC cells than in non-IBC cells. Clonogenic survival following 24 hours of HDL treatment was decreased in response to irradiation in the low-miR-33a–expressing cell lines SUM149 and KPL4, but survival following HDL treatment decreased in the high-miR-33a–expressing cell lines MDA-MB-231 and SUM159. In the high-miR-33a–expressing cell lines, anti-miR-33a transfection decreased radiation resistance in clonogenic assays. Conversely, in the low-miR-33a–expressing cell lines, the miR-33a mimic reversed the HDL-induced radiation sensitization. Breast cancer patients in the top quartile based on miR-33a expression had markedly lower rates of DRFS than the bottom quartile (P

  20. MiR-33a Decreases High-Density Lipoprotein-Induced Radiation Sensitivity in Breast Cancer

    International Nuclear Information System (INIS)

    Wolfe, Adam R.; Bambhroliya, Arvind; Reddy, Jay P.; Debeb, Bisrat G.; Huo, Lei; Larson, Richard; Li, Li; Ueno, Naoto T.; Woodward, Wendy A.

    2016-01-01

    Purpose: We previously showed that high-density lipoprotein (HDL) radiosensitizes inflammatory breast cancer (IBC) cells in vitro and is associated with better local control after radiation therapy in IBC patients. The microRNA miR-33 family negatively regulates the adenosine triphosphate binding cassette transporter subfamily A member 1. We hypothesized that variations in miR-33a expression in IBC cancer cells versus non-IBC cells would correlate with radiation sensitivity following exposure to HDL in vitro. Methods and Materials: MiR-33a expression was analyzed by reverse transcriptase–polymerase chain reaction in 4 cell lines representing common clinical breast cancer subtypes. Overexpression and knockdown of miR-33a was demonstrated via transfection of an miR-33a mimic or an anti-miR-33a construct in high- and low-expressing miR-33a cell lines. Clonogenic survival in vitro in these cells was quantified at baseline and following HDL treatment. MiR-33a expression on distant relapse-free survival (DRFS) of 210 cases downloaded from the Oxford breast cancer dataset was determined. Results: Expression levels of miR-33a were lower in IBC cell lines and IBC tumor samples than in non-IBC cell lines and normal breast tissue. Cholesterol concentrations in the cell membranes were higher in IBC cells than in non-IBC cells. Clonogenic survival following 24 hours of HDL treatment was decreased in response to irradiation in the low-miR-33a–expressing cell lines SUM149 and KPL4, but survival following HDL treatment decreased in the high-miR-33a–expressing cell lines MDA-MB-231 and SUM159. In the high-miR-33a–expressing cell lines, anti-miR-33a transfection decreased radiation resistance in clonogenic assays. Conversely, in the low-miR-33a–expressing cell lines, the miR-33a mimic reversed the HDL-induced radiation sensitization. Breast cancer patients in the top quartile based on miR-33a expression had markedly lower rates of DRFS than the bottom quartile (P

  1. Supercritical CO2 foaming of radiation crosslinked polypropylene/high-density polyethylene blend: Cell structure and tensile property

    Science.gov (United States)

    Yang, Chenguang; Xing, Zhe; Zhang, Mingxing; Zhao, Quan; Wang, Mouhua; Wu, Guozhong

    2017-12-01

    A blend of isotactic polypropylene (PP) with high-density polyethylene (HDPE) in different PP/HDPE ratios was irradiated by γ-ray to induce cross-linking and then foamed using supercritical carbon dioxide (scCO2) as a blowing agent. Radiation effect on the melting point and crystallinity were analyzed in detail. The average cell diameter and cell density were compared for PP/HDPE foams prepared under different conditions. The optimum absorbed dose for the scCO2 foaming of PP/HDPE in terms of foaming ability and cell structure was 20 kGy. Tensile measurements showed that the elongation at break and tensile strength at break of the crosslinked PP/HDPE foams were higher than the non-crosslinked ones. Of particular interest was the increase in the foaming temperature window from 4 ℃ for pristine PP to 8-12 ℃ for the radiation crosslinked PP/HDPE blends. This implies much easier handling of scCO2 foaming of crosslinked PP with the addition of HDPE.

  2. Laser radiation short pulse absorption in a high-density plasma

    International Nuclear Information System (INIS)

    Brantov, A.V.; Bychenkov, V.Yu.; Tikhonchuk, V.T.

    1998-01-01

    Dependences of the absorption coefficients for s and p polarized electromagnetic waves (laser radiation) in a semi-bound plasma on the temperature and incidence angle are found for an arbitrary ratio of the skin-layer depth to the electron free path length t. The dependences obtained describe transition from the normal skin effect to abnormal one and permit quantitatively to determine the absorption coefficients in the intermediate range of the parameter t, characteristic for the majority of modern experiments

  3. Electrical resistivity of carbon black-filled high-density polyethylene (HDPE) composite containing radiation crosslinked HDPE particles

    International Nuclear Information System (INIS)

    Lee, M.-G.; Nho, Y.C.

    2001-01-01

    The room-temperature volume resistivity of high-density polyethylene (HDPE)-carbon black (CB) blends containing previously radiation crosslinked HDPE powder was studied. The results showed that the room-temperature volume resistivity decreases with increasing concentration of crosslinked HDPE powder. It is considered that the crosslinked HDPE particles act as a filler that increases the CB volume fraction in the HDPE matrix. The results of an optical microscope observation indicated that the crosslinked polymer particles are dispersed in the HDPE/CB composite. This effect of the crosslinked particles is attributed to the fact that the crosslinked mesh size of the HDPE particles is so small that the CB particles cannot go inside them. The effect of 60 Co γ-ray and electron beam (EB) irradiation on the positive temperature coefficient, negative temperature coefficient and electrical resistivity behavior of the blends were studied

  4. New self-similar radiation-hydrodynamics solutions in the high-energy density, equilibrium diffusion limit

    International Nuclear Information System (INIS)

    Lane, Taylor K; McClarren, Ryan G

    2013-01-01

    This work presents semi-analytic solutions to a radiation-hydrodynamics problem of a radiation source driving an initially cold medium. Our solutions are in the equilibrium diffusion limit, include material motion and allow for radiation-dominated situations where the radiation energy is comparable to (or greater than) the material internal energy density. As such, this work is a generalization of the classical Marshak wave problem that assumes no material motion and that the radiation energy is negligible. Including radiation energy density in the model serves to slow down the wave propagation. The solutions provide insight into the impact of radiation energy and material motion, as well as present a novel verification test for radiation transport packages. As a verification test, the solution exercises the radiation–matter coupling terms and their v/c treatment without needing a hydrodynamics solve. An example comparison between the self-similar solution and a numerical code is given. Tables of the self-similar solutions are also provided. (paper)

  5. On radiative density limits in stellarators

    International Nuclear Information System (INIS)

    Wobig, H.

    2001-01-01

    Density limits in stellarators are caused mainly by enhanced impurity radiation leading to a collapse of the temperature. A simple model can be established, which computes the temperature in the plasma with a fixed heating profile and a temperature-dependent radiation profile. If the temperature-dependent radiation function has one or several extrema, multiple solutions of the transport equation exist and radiative collapse occurs when the high temperature branch merges with the unstable temperature branch. At this bifurcation point the temperature decreases to a stable low temperature solution. The bifurcation point is a function of the heating power and the plasma density. Thus a density limit can be defined as the point where bifurcation occurs. It is shown that bifurcation and sudden temperature collapse does not occur below a power threshold. Anomalous thermal conductivity and the details of the impurity radiation, which in the present model is assumed to be in corona equilibrium, determine the scaling of the density limit. A model of the anomalous transport is developed, which leads to Gyro-Bohm scaling of the confinement time. The density limit based on this transport model is close to experimental findings in Wendelstein 7-AS. (author)

  6. Natural fibre high-density polyethylene and lead oxide composites for radiation shielding

    CERN Document Server

    El-Sayed, A; Ismail, M R

    2003-01-01

    Study has been made of the radiation shielding provided by recycled agricultural fibre and industrial plastic wastes produced as composite materials. Fast neutron and gamma-ray spectra behind composites of fibre-plastic (rho = 1.373 g cm sup - sup 3) and fibre-plastic-lead (rho = 2.756 g cm sup - sup 3) have been measured using a collimated reactor beam and neutron-gamma spectrometer with a stilbene scintillator. The pulse shape discriminating technique based on the zero-cross-over method was used to discriminate between neutron and gamma-ray pulses. Slow neutron fluxes have been measured using a collimated reactor beam and BF sub 3 counter, leading to determination of the macroscopic cross-section (SIGMA). The removal cross-sections (SIGMA sub R) of fast neutrons have been determined from measured results and elemental composition of the composites. For gamma-rays, total linear attenuation coefficients (mu) and total mass attenuation coefficients (mu/rho) have been determined from use of the XCOM code and me...

  7. A High Density Low Cost Digital Signal Processing Module for Large Scale Radiation Detectors

    International Nuclear Information System (INIS)

    Tan, Hui; Hennig, Wolfgang; Walby, Mark D.; Breus, Dimitry; Harris, Jackson T.; Grudberg, Peter M.; Warburton, William K.

    2013-06-01

    A 32-channel digital spectrometer PIXIE-32 is being developed for nuclear physics or other radiation detection applications requiring digital signal processing with large number of channels at relatively low cost. A single PIXIE-32 provides spectrometry and waveform acquisition for 32 input signals per module whereas multiple modules can be combined into larger systems. It is based on the PCI Express standard which allows data transfer rates to the host computer of up to 800 MB/s. Each of the 32 channels in a PIXIE-32 module accepts signals directly from a detector preamplifier or photomultiplier. Digitally controlled offsets can be individually adjusted for each channel. Signals are digitized in 12-bit, 50 MHz multi-channel ADCs. Triggering, pile-up inspection and filtering of the data stream are performed in real time, and pulse heights and other event data are calculated on an event-by event basis. The hardware architecture, internal and external triggering features, and the spectrometry and waveform acquisition capability of the PIXIE- 32 as well as its capability to distribute clock and triggers among multiple modules, are presented. (authors)

  8. Study of combinations of TL/OSL single dosimeters for mixed high/low ionization density radiation fields

    International Nuclear Information System (INIS)

    Oster, L.; Druzhyna, S.; Orion, I.; Horowitz, Y.S.

    2013-01-01

    In this paper we discuss and compare the potential application of combined OSL/TL measurements using 6 LiF:Mg,Ti (TLD-600 is enriched of isotope 6 Li which has a high cross-section for the reaction with slow neutrons) or 7 LiF:Mg,Ti ( TLD-700 is enriched of 7 Li isotope) and TLD-100 (natural isotopic composition) detectors. The OSL/TL duel readout of LiF:Mg,Ti as an ionization density discriminator avoids some of the difficulties inherent to the various types of discrimination mixed-field passive dosimeters, and in addition has several advantages. The preferential excitation of OSL compared to TL following high ionization density (HID) alpha irradiation, naturally explained via the identification of OSL with the “two-hit” F 2 or F 3 center, whereas the major component of composite TL glow peak 5 is believed to arise from a ''one-hit'' complex defect. This evidence allows near-total discrimination between HID radiation and low-ionization density (LID) radiation. Beta and alpha particle irradiations were carried out with 90 Sr/ 90 Y (∼500 keV average energy) and 241 Am sources (4.7 MeV) respectively and neutron irradiations were carried out at the PTB (Germany) (E n = 5 MeV) and RARAF (Columbia University, USA) (E n = 6 MeV) accelerator facilities. The highest values of the FOM obtained was ∼30 for neutron/gamma discrimination and ∼110 for alpha/gamma discrimination using OSL/TL – peak 5 measurements in TLD-700. -- Highlights: ► The increased response of OSL compared to TL following HID irradiation is observed. ► This evidence is explained via the identification of OSL with the ''two-hit'' F2 centers. ► The potential application of combined OSL/TL in discrimination dosimetry is discussed. ► The values of FOM were 110 for alpha/gamma and 30 for neutron/gamma discrimination

  9. Applications of high order harmonic radiation to UVX-solids interaction: high excitation density in electronic relaxation dynamics and surface damaging

    International Nuclear Information System (INIS)

    De Grazia, M.

    2007-12-01

    The new sources of radiation in the extreme-UV (X-UV: 10-100 nm), which deliver spatially coherent, ultra-short and intense pulses, allow studying high flux processes and ultra-fast dynamics in various domains. The thesis work presents two applications of the high-order laser harmonics (HH) to solid state physics. In Part I, we describe the optimization of the harmonic for studies of X-UV/solids interaction. In Part II, we investigate effects of high excitation density in the dynamics of electron relaxation in dielectric scintillator crystals - tungstates and fluorides, using time-resolved luminescence spectroscopy. Quenching of luminescence at short time gives evidence of the competition between radiative and non-radiative recombination of self-trapped excitons (STE). The non-radiative channel is identified to mutual interaction of STE at high excitation density. In Part III, we study the X-UV induced damage mechanism in various materials, either conductor (amorphous carbon) or insulators (organic polymers, e.g., PMMA). In PMMA-Plexiglas, in the desorption regime (0.2 mJ/cm 2 , i.e., below damage threshold), the surface modifications reflect X-UV induced photochemical processes that are tentatively identified, as a function of dose: at low dose, polymer chain scission followed by the blow-up of the volatile, low-molecular fragments leads to crater formation; at high dose, cross-linking in the near-surface layer of remaining material leads to surface hardening. These promising results have great perspectives considering the performances already attained and planned in the next future in the development of the harmonic sources. (author)

  10. Effect of ionizing radiation on nanocomposites of high density polyethylene with pseudoboehmite obtained by sol-gel process

    International Nuclear Information System (INIS)

    Miranda, Leila F.; Munhoz Junior, Antonio H.; Terence, Mauro C.; Alves, Alexandre P.

    2009-01-01

    Nanocomposites are polymeric hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. The fillers present area of raised surface, promoting better dispersion in the polymeric matrix and therefore an improvement of the physical properties of the composite that depends on the homogeneity of the material. The nanocomposites preparation with polymeric matrix allows in many cases to find a relation enters a low cost, due to the use of minor amount of filler, and a raised performance level. Nanocomposites were obtained with pseudoboehmite synthesized by sol-gel process and high density polyethylene with different concentrations of pseudoboehmite. The aim of this work was to study the effects of ionizing radiation on the properties of the nanocomposites obtained. The nanocomposites were prepared by melt intercalation technique and subsequently, the samples were molded by injection, irradiated and submitted to thermal and mechanical tests. The mechanical properties (impact strength and tensile strength), temperature of thermal distortion (HDT) and Vicat softening temperature of the non irradiated and irradiated nanocomposites were determined. The irradiation doses were of 30, 50 and 100kGy in a gamma cell. The results showed an increase in the values of tensile strength; a decrease in the impact strength and an increase in the temperature of thermal distortion (HDT) evidencing the interaction of nanofiller with the polymeric matrix. (author)

  11. High density dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, G.L.

    1996-01-01

    A fuel development campaign that results in an aluminum plate-type fuel of unlimited LEU burnup capability with an uranium loading of 9 grams per cm 3 of meat should be considered an unqualified success. The current worldwide approved and accepted highest loading is 4.8 g cm -3 with U 3 Si 2 as fuel. High-density uranium compounds offer no real density advantage over U 3 Si 2 and have less desirable fabrication and performance characteristics as well. Of the higher-density compounds, U 3 Si has approximately a 30% higher uranium density but the density of the U 6 X compounds would yield the factor 1.5 needed to achieve 9 g cm -3 uranium loading. Unfortunately, irradiation tests proved these peritectic compounds have poor swelling behavior. It is for this reason that the authors are turning to uranium alloys. The reason pure uranium was not seriously considered as a dispersion fuel is mainly due to its high rate of growth and swelling at low temperatures. This problem was solved at least for relatively low burnup application in non-dispersion fuel elements with small additions of Si, Fe, and Al. This so called adjusted uranium has nearly the same density as pure α-uranium and it seems prudent to reconsider this alloy as a dispersant. Further modifications of uranium metal to achieve higher burnup swelling stability involve stabilization of the cubic γ phase at low temperatures where normally α phase exists. Several low neutron capture cross section elements such as Zr, Nb, Ti and Mo accomplish this in various degrees. The challenge is to produce a suitable form of fuel powder and develop a plate fabrication procedure, as well as obtain high burnup capability through irradiation testing

  12. High-energy Gamma Rays from the Milky Way: Three-dimensional Spatial Models for the Cosmic-Ray and Radiation Field Densities in the Interstellar Medium

    Energy Technology Data Exchange (ETDEWEB)

    Porter, T. A.; Moskalenko, I. V. [W. W. Hansen Experimental Physics Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Jóhannesson, G., E-mail: tporter@stanford.edu [Science Institute, University of Iceland, IS-107 Reykjavik (Iceland)

    2017-09-01

    High-energy γ -rays of interstellar origin are produced by the interaction of cosmic-ray (CR) particles with the diffuse gas and radiation fields in the Galaxy. The main features of this emission are well understood and are reproduced by existing CR propagation models employing 2D galactocentric cylindrically symmetrical geometry. However, the high-quality data from instruments like the Fermi Large Area Telescope reveal significant deviations from the model predictions on few to tens of degrees scales, indicating the need to include the details of the Galactic spiral structure and thus requiring 3D spatial modeling. In this paper, the high-energy interstellar emissions from the Galaxy are calculated using the new release of the GALPROP code employing 3D spatial models for the CR source and interstellar radiation field (ISRF) densities. Three models for the spatial distribution of CR sources are used that are differentiated by their relative proportion of input luminosity attributed to the smooth disk or spiral arms. Two ISRF models are developed based on stellar and dust spatial density distributions taken from the literature that reproduce local near- to far-infrared observations. The interstellar emission models that include arms and bulges for the CR source and ISRF densities provide plausible physical interpretations for features found in the residual maps from high-energy γ -ray data analysis. The 3D models for CR and ISRF densities provide a more realistic basis that can be used for the interpretation of the nonthermal interstellar emissions from the Galaxy.

  13. Generation of intense X-radiation and high-energy-density matter by laser-accelerated electrons; Erzeugung von intensiver Roentgenstrahlung und Materie hoher Energiedichte durch Laserbeschleunigte Elektronen

    Energy Technology Data Exchange (ETDEWEB)

    Schoenlein, Andreas

    2015-07-01

    Aim of this thesis was to study the processes of the interaction between highly intense short-pulse laser and matter. The focus lied thereby on the generation of intense X-radiation and warm dense matter. The studies performed for this thesis comprehend thereby the influence of laser parameters like energy, pulse length, focus size, and intensity as well as the influence of the target geometry on the interaction and generation of high-energy-density matter. In this thesis for this two selected experiments are presented. First a silver foil was used as target, in order to study the generation of radiation at 21 keV. Both bremsstrahlung and characteristic X-radiation were used in order to characterize the interaction. For the second experiment freely standing titanium wires were used as target. Hereby the focus lied on the characterization of the heated matter.

  14. Interfacial Shear Strength Evaluation of Pinewood Residue/High-Density Polyethylene Composites Exposed to UV Radiation and Moisture Absorption-Desorption Cycles

    Directory of Open Access Journals (Sweden)

    Soledad C. Pech-Cohuo

    2016-03-01

    Full Text Available In outdoor applications, the mechanical performance of wood-plastic composites (WPCs is affected by UV radiation, facilitating moisture intake and damaging the wood-polymer interfacial region. The purpose of this study was to evaluate the effect of moisture absorption-desorption cycles (MADCs, and the exposure to UV radiation on the interfacial shear strength (IFSS of WPCs with 40% pinewood residue and 60% high-density polyethylene. One of the WPCs incorporated 5% coupling agent (CA with respect to wood content. The IFSS was evaluated following the Iosipescu test method. The specimens were exposed to UV radiation using an accelerated weathering test device and subsequently subjected to four MADCs. Characterization was also performed by scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FTIR. The absorption and desorption of moisture was slower in non-UV-irradiated WPCs, particularly in those with the CA. The UV radiation did not significantly contribute to the loss of the IFSS. Statistically, the CA had a favorable effect on the IFSS. Exposure of the samples to MADCs contributed to reduce the IFSS. The FTIR showed lignin degradation and the occurrence of hydrolysis reactions after exposure to MADCs. SEM confirmed that UV radiation did not significantly affect the IFSS.

  15. High density hydrogen research

    International Nuclear Information System (INIS)

    Hawke, R.S.

    1977-01-01

    The interest in the properties of very dense hydrogen is prompted by its abundance in Saturn and Jupiter and its importance in laser fusion studies. Furthermore, it has been proposed that the metallic form of hydrogen may be a superconductor at relatively high temperatures and/or exist in a metastable phase at ambient pressure. For ten years or more, laboratories have been developing the techniques to study hydrogen in the megabar region (1 megabar = 100 GPa). Three major approaches to study dense hydrogen experimentally have been used, static presses, shockwave compression, and magnetic compression. Static tchniques have crossed the megabar threshold in stiff materials but have not yet been convincingly successful in very compressible hydrogen. Single and double shockwave techniques have improved the precision of the pressure, volume, temperature Equation of State (EOS) of molecular hydrogen (deuterium) up to near 1 Mbar. Multiple shockwave and magnetic techniques have compressed hydrogen to several megabars and densities in the range of the metallic phase. The net result is that hydrogen becomes conducting at a pressure between 2 and 4 megabars. Hence, the possibility of making a significant amount of hydrogen into a metal in a static press remains a formidable challenge. The success of such experiments will hopefully answer the questions about hydrogen's metallic vs. conducting molecular phase, superconductivity, and metastability. 4 figures, 15 references

  16. Radiation effect test on ADC/DAC and high density memory devices with 60Co γ-rays

    International Nuclear Information System (INIS)

    Xing Kefei; Wang Yueke; Pan Huafeng

    2006-01-01

    A test platform was constructed for 60 Co γ-ray irradiation experiment of microelectronics, with the aid of computer and a FPGA module. The tested sample devices included analog-to-digital converter AD10465, digital-to-analog converter AD9857, high density Flash memory MEF64M16 and anti-fused PROM XQR17V16, which are used in signal processing module in spaceborne systems. Evaluations were made on their ability of resisting the total dose based on the proper function criterion of the devices. The results showed that AD10465 and AD9857 ran properly after 1.59 kGy(Si) irradiation, but errors were found when MEF64M16 and XQR17V16's total ionizing dose is 0.13 kGy(Si) and 0.99 kGy(Si), respectively. (authors)

  17. High Power Density Motors

    Science.gov (United States)

    Kascak, Daniel J.

    2004-01-01

    With the growing concerns of global warming, the need for pollution-free vehicles is ever increasing. Pollution-free flight is one of NASA's goals for the 21" Century. , One method of approaching that goal is hydrogen-fueled aircraft that use fuel cells or turbo- generators to develop electric power that can drive electric motors that turn the aircraft's propulsive fans or propellers. Hydrogen fuel would likely be carried as a liquid, stored in tanks at its boiling point of 20.5 K (-422.5 F). Conventional electric motors, however, are far too heavy (for a given horsepower) to use on aircraft. Fortunately the liquid hydrogen fuel can provide essentially free refrigeration that can be used to cool the windings of motors before the hydrogen is used for fuel. Either High Temperature Superconductors (HTS) or high purity metals such as copper or aluminum may be used in the motor windings. Superconductors have essentially zero electrical resistance to steady current. The electrical resistance of high purity aluminum or copper near liquid hydrogen temperature can be l/lOO* or less of the room temperature resistance. These conductors could provide higher motor efficiency than normal room-temperature motors achieve. But much more importantly, these conductors can carry ten to a hundred times more current than copper conductors do in normal motors operating at room temperature. This is a consequence of the low electrical resistance and of good heat transfer coefficients in boiling LH2. Thus the conductors can produce higher magnetic field strengths and consequently higher motor torque and power. Designs, analysis and actual cryogenic motor tests show that such cryogenic motors could produce three or more times as much power per unit weight as turbine engines can, whereas conventional motors produce only 1/5 as much power per weight as turbine engines. This summer work has been done with Litz wire to maximize the current density. The current is limited by the amount of heat it

  18. A PD-SOI based DTI-LOCOS combined cross isolation technique for minimizing TID radiation induced leakage in high density memory

    International Nuclear Information System (INIS)

    Qiao Fengying; Pan Liyang; Wu Dong; Liu Lifang; Xu Jun

    2014-01-01

    In order to minimize leakage current increase under total ionizing dose (TID) radiation in high density memory circuits, a new isolation technique, combining deep trench isolation (DTI) between the wells, local oxidation of silicon (LOCOS) isolation between the devices within the well, and a P-diffused area in order to limit leakage at the isolation edge is implemented in partly-depleted silicon-on-insulator (PD-SOI) technology. This radiation hardening technique can minimize the layout area by more than 60%, and allows flexible placement of the body contact. Radiation hardened transistors and 256 Kb flash memory chips are designed and fabricated in a 0.6 μm PD-SOI process. Experiments show that no obvious increase in leakage current is observed for single transistors under 1 Mrad(Si) radiation, and that the 256 Kb memory chip still functions well after a TID of 100 krad(Si), with only 50% increase of the active power consumption in read mode. (semiconductor devices)

  19. On the possibility of gamma-laser pumping occurring at a charged particle counter motion and in density-modulated electron beams by a high frequency intensive radiation

    International Nuclear Information System (INIS)

    Maksyuta, N.V.

    1999-01-01

    The given report deals with the problem of motion and radiation of relativistic electron in a field of opposite plane density-modulated relativistic electron beam. Physical essence of high-frequency intensive radiation origin could be explained, first by the additional Lorentz reduction of the electron beam modulation period (modulation period Λ in a laboratory co-ordinate system reduces by a factor γ as compared with the modulation period in a beam co-ordinate system) and, secondly, a simultaneous γ-fold increase of transverse components of relativistic electrons of the beam electric and magnetic fields. Such a moving modulated electron beam can be regarded as a dynamic micro-ondulator. Unlike static micro-ondulators we can observe here one more positive moment along with a small period Λ = Λ'/γ, i.e. the electric and magnetic fields in a transverse direction are changed according to the law of exp(-2πx/Λ'). It means that charged particle interaction with a dynamic micro-ondulator will be effective in a wide range of transverse distances, i.e., to get an intensive short wave radiation one can use charged particle beams with rather large apertures which leads to an additional radiation intensity increase. A discussion is given showing that the proposed dynamic modulator possesses some essential merits. A detailed calculation is presented. (author)

  20. The modified high-density survival assay is the useful tool to predict the effectiveness of fractionated radiation exposure

    International Nuclear Information System (INIS)

    Kuwahara, Yoshikazu; Mori, Miyuki; Oikawa, Toshiyuki; Shimura, Tsutomu; Fukumoto, Manabu; Ohtake, Yosuke; Ohkubo, Yasuhito; Mori, Shiro

    2010-01-01

    The high-density survival (HDS) assay was originally elaborated to assess cancer cell responses to therapeutic agents under the influence of intercellular communication. Here, we simplified the original HDS assay and studied its applicability for the detection of cellular radioresistance. We have recently defined clinically relevant radioresistant (CRR) cells, which continue to proliferate with daily exposure to 2 gray (Gy) of X-rays for more than 30 days in vitro. We established human CRR cell lines, HepG2-8960-R from HepG2, and SAS-R1 and -R2 from SAS, respectively. In an attempt to apply the HDS assay to detect radioresistance with clinical relevance, we simplified the original HDS assay by scoring the total number of surviving cells after exposure to X-rays. The modified HDS assay successfully detected radioresistance with clinical relevance. The modified HDS assay detected CRR phenotype, which is not always detectable by clonogenic assay. Therefore, we believe that the modified HDS assay presented in this study is a powerful tool to predict the effectiveness of fractionated radiotherapy against malignant tumors. (author)

  1. Small-angle x-ray scattering and density measurements of liquid Se50-Te50 mixture at high temperatures and high pressures using synchrotron radiation

    International Nuclear Information System (INIS)

    Kajihara, Y; Inui, M; Matsuda, K; Tomioka, Y

    2010-01-01

    We have carried out small-angle x-ray scattering and x-ray transmission measurements of liquid Se 50 -Te 50 mixture at SPring-8 in Japan and obtained the structure factor S(Q) at small-Q region (0.6 -1 ) and the density at high temperatures and high pressures up to 1000 0 C and 180 MPa. We report preliminary results in this paper. With increasing temperature, the density shows a minimum at around 500 0 C and a maximum at around 700 0 C. On the other hand, S(0) becomes maximum and S(Q) strongly depends on Q at around 600 0 C, which is about the middle temperature where the density shows the minimum and maximum. The temperatures shift to lower side when the pressure increases. These results prove that, with increasing temperature, the sample exhibits gradual transition from low-density structure to high-density structure, which causes mesoscopic density fluctuations in the intermediate temperature region.

  2. Characterization of the degree of cross-linking in radiation cross-linked low and high density polyethylenes

    International Nuclear Information System (INIS)

    Posselt, K.; Haedrich, W.

    1986-01-01

    In practice the cross-linking of irradiated polyethylene is mostly characterized by solubility and thermomechanical data. The irradiation of samples of a LDPE and a HDPE yields very different gel-dose curves. But for a quantitative comparison the complicated connection between the gel values and the corresponding densities of cross-links, especially the dependence on the initial molecular size distribution, has to take into consideration. The analysis of the solubility data according to the statistical theory of cross-linking developed by Inokuti and Saito shows that at equal doses in both investigated PE types in spite of the different gel values nearly the same densities of cross-links are present. That result is confirmed by the densities of cross-links determined from stress-strain measurements at 423 K. (author)

  3. High current density ion source

    International Nuclear Information System (INIS)

    King, H.J.

    1977-01-01

    A high-current-density ion source with high total current is achieved by individually directing the beamlets from an electron bombardment ion source through screen and accelerator electrodes. The openings in these screen and accelerator electrodes are oriented and positioned to direct the individual beamlets substantially toward a focus point. 3 figures, 1 table

  4. Density perturbations in a braneworld universe with dark radiation

    International Nuclear Information System (INIS)

    Gumjudpai, Burin; Maartens, Roy; Gordon, Christopher

    2003-01-01

    We investigate the effects on cosmological density perturbations of dark radiation in a Randall-Sundrum 2-type braneworld. Dark radiation in the background is limited by observational constraints to be a small fraction of the radiation energy density, but it has an interesting qualitative effect in the radiation era. On large scales, it serves to slightly suppress the radiation density perturbations at late times, while boosting the perturbations in dark radiation. In a kinetic (stiff) era, the suppression is much stronger, and drives the density perturbations to zero

  5. Photoionization and High Density Gas

    Science.gov (United States)

    Kallman, T.; Bautista, M.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We present results of calculations using the XSTAR version 2 computer code. This code is loosely based on the XSTAR v.1 code which has been available for public use for some time. However it represents an improvement and update in several major respects, including atomic data, code structure, user interface, and improved physical description of ionization/excitation. In particular, it now is applicable to high density situations in which significant excited atomic level populations are likely to occur. We describe the computational techniques and assumptions, and present sample runs with particular emphasis on high density situations.

  6. High-density multicore fibers

    DEFF Research Database (Denmark)

    Takenaga, K.; Matsuo, S.; Saitoh, K.

    2016-01-01

    High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber.......High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber....

  7. High density matter at RHIC

    Indian Academy of Sciences (India)

    QCD predicts a phase transition between hadronic matter and a quark-gluon plasma at high energy density. The relativistic heavy ion collider (RHIC) at Brookhaven National Laboratory is a new facility dedicated to the experimental study of matter under extreme conditions. Already the first round of experimental results at ...

  8. High density operation in pulsator

    International Nuclear Information System (INIS)

    Klueber, O.; Cannici, B.; Engelhardt, W.; Gernhardt, J.; Glock, E.; Karger, F.; Lisitano, G.; Mayer, H.M.; Meisel, D.; Morandi, P.

    1976-03-01

    This report summarizes the results of experiments at high electron densities (>10 14 cm -3 ) which have been achieved by pulsed gas inflow during the discharge. At these densities a regime is established which is characterized by βsub(p) > 1, nsub(i) approximately nsub(e), Tsub(i) approximately Tsub(e) and tausub(E) proportional to nsub(e). Thus the toroidal magnetic field contributes considerably to the plasma confinement and the ions constitute almost half of the plasma pressure. Furthermore, the confinement is appreciably improved and the plasma becomes impermeable to hot neutrals. (orig.) [de

  9. Laser fusion and high energy density science

    International Nuclear Information System (INIS)

    Kodama, Ryosuke

    2005-01-01

    High-power laser technology is now opening a variety of new fields of science and technology using laser-produced plasmas. The laser plasma is now recognized as one of the important tools for the investigation and application of matter under extreme conditions, which is called high energy density science. This chapter shows a variety of applications of laser-produced plasmas as high energy density science. One of the more attractive industrial and science applications is the generation of intense pulse-radiation sources, such as the generation of electro-magnetic waves in the ranges of EUV (Extreme Ultra Violet) to gamma rays and laser acceleration of charged particles. The laser plasma is used as an energy converter in this regime. The fundamental science applications of high energy density physics are shown by introducing laboratory astrophysics, the equation of state of high pressure matter, including warm dense matter and nuclear science. Other applications are also presented, such as femto-second laser propulsion and light guiding. Finally, a new systematization is proposed to explore the possibility of the high energy density plasma application, which is called high energy plasma photonics''. This is also exploration of the boundary regions between laser technology and beam optics based on plasma physics. (author)

  10. Perspectives on High-Energy-Density Physics

    Science.gov (United States)

    Drake, R. Paul

    2008-11-01

    Much of 21st century plasma physics will involve work to produce, understand, control, and exploit very non-traditional plasmas. High-energy density (HED) plasmas are often examples, variously involving strong Coulomb interactions and few particles per Debeye sphere, dominant radiation effects, strongly relativistic effects, or strongly quantum-mechanical behavior. Indeed, these and other modern plasma systems often fall outside the early standard theoretical definitions of ``plasma''. This presentation will focus on two types of HED plasmas that exhibit non-traditional behavior. Our first example will be the plasmas produced by extremely strong shock waves. Shock waves are present across the entire realm of plasma densities, often in space or astrophysical contexts. HED shock waves (at pressures > 1 Mbar) enable studies in many areas, from equations of state to hydrodynamics to radiation hydrodynamics. We will specifically consider strongly radiative shocks, in which the radiative energy fluxes are comparable to the mechanical energy fluxes that drive the shocks. Modern HED facilities can produce such shocks, which are also present in dense, energetic, astrophysical systems such as supernovae. These shocks are also excellent targets for advanced simulations due to their range of spatial scales and complex radiation transport. Our second example will be relativistic plasmas. In general, these vary from plasmas containing relativistic particle beams, produced for some decades in the laboratory, to the relativistic thermal plasmas present for example in pulsar winds. Laboratory HED relativistic plasmas to date have been those produced by laser beams of irradiance ˜ 10^18 to 10^22 W/cm^2 or by accelerator-produced HED electron beams. These have applications ranging from generation of intense x-rays to production of proton beams for radiation therapy to acceleration of electrons. Here we will focus on electron acceleration, a spectacular recent success and a rare

  11. High density fuel storage rack

    International Nuclear Information System (INIS)

    Zezza, L.J.

    1980-01-01

    High storage density for spent nuclear fuel assemblies in a pool achieved by positioning fuel storage cells of high thermal neutron absorption materials in an upright configuration in a rack. The rack holds the cells at required pitch. Each cell carries an internal fuel assembly support, and most cells are vertically movable in the rack so that they rest on the pool bottom. Pool water circulation through the cells and around the fuel assemblies is permitted by circulation openings at the top and bottom of the cells above and below the fuel assemblies

  12. Double trouble at high density:

    DEFF Research Database (Denmark)

    Gergs, André; Palmqvist, Annemette; Preuss, Thomas G

    2014-01-01

    Population size is often regulated by negative feedback between population density and individual fitness. At high population densities, animals run into double trouble: they might concurrently suffer from overexploitation of resources and also from negative interference among individuals...... regardless of resource availability, referred to as crowding. Animals are able to adapt to resource shortages by exhibiting a repertoire of life history and physiological plasticities. In addition to resource-related plasticity, crowding might lead to reduced fitness, with consequences for individual life...... history. We explored how different mechanisms behind resource-related plasticity and crowding-related fitness act independently or together, using the water flea Daphnia magna as a case study. For testing hypotheses related to mechanisms of plasticity and crowding stress across different biological levels...

  13. High energy radiation detector

    International Nuclear Information System (INIS)

    Vosburgh, K.G.

    1975-01-01

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

  14. On the correctness of the thermoluminescent high-temperature ratio (HTR) method for estimating ionization density effects in mixed radiation fields

    International Nuclear Information System (INIS)

    Bilski, Pawel

    2010-01-01

    The high-temperature ratio (HTR) method which exploits changes in the LiF:Mg,Ti glow-curve due to high-LET radiation, has been used for several years to estimate LET in an unknown radiation field. As TL efficiency is known to decrease after doses of densely ionizing radiation, a LET estimate is used to correct the TLD-measured values of dose. The HTR method is purely empirical and its general correctness is questionable. The validity of the HTR method was investigated by theoretical simulation of various mixed radiation fields. The LET eff values estimated with the HTR method for mixed radiation fields were found in general to be incorrect, in some cases underestimating the true values of dose-averaged LET by an order of magnitude. The method produced correct estimates of average LET only in cases of almost mono-energetic fields (i.e. in non-mixed radiation conditions). The value of LET eff found by the HTR method may therefore be treated as a qualitative indicator of increased LET, but not as a quantitative estimator of average LET. However, HTR-based correction of the TLD-measured dose value (HTR-B method) was found to be quite reliable. In all cases studied, application of this technique improved the result. Most of the measured doses fell within 10% of the true values. A further empirical improvement to the method is proposed. One may therefore recommend the HTR-B method to correct for decreased TL efficiency in mixed high-LET fields.

  15. Radiation power profiles and density limit with a divertor in the W7-AS stellarator

    International Nuclear Information System (INIS)

    Giannone, L.; Burhenn, R.; McCormick, K.; Brakel, R.; Feng, Y.; Grigull, P.; Igitkhanov, Y.

    2002-01-01

    The addition of a divertor into the W7-AS stellarator has allowed access to a high density regime where the radiation profiles reach a steady state. In earlier limiter discharges, the plasma suffered a radiative collapse at high densities. In contrast to limiter experiments, where the impurity confinement time measured by Al laser blow-off increased with increasing line integrated density, in divertor discharges, above a density threshold, the impurity confinement time decreased with increasing line integrated density. The observation that the divertor plasma radiates mainly at the plasma edge rather than the plasma centre is a further indication that changes to the impurity transport coefficients at these high densities are the basis for the achievement of steady state discharges in the divertor configuration of W7-AS. The maximum line integrated density reached with a divertor is compared to that reached with a limiter. The previously derived scaling law for the density limit with a limiter shows that the achieved densities do not exceed those predicted when the higher deposited power is taken into account. In a divertor the radiated power is located at the plasma edge and increasing the density, cooling the plasma edge and radiating sufficient power to cause plasma detachment determines the density limit. (author)

  16. Importing low-density ideas to high-density revitalisation

    DEFF Research Database (Denmark)

    Arnholtz, Jens; Ibsen, Christian Lyhne; Ibsen, Flemming

    2016-01-01

    Why did union officials from a high-union-density country like Denmark choose to import an organising strategy from low-density countries such as the US and the UK? Drawing on in-depth interviews with key union officials and internal documents, the authors of this article argue two key points. Fi...

  17. The effect of radiation dose on the crosslink density of ultra-high molecular weight polyethylene (UHMWPE) measured by a novel swelling method

    International Nuclear Information System (INIS)

    Muratoglu, O.K.; Bragdon, C.R.; O'Connor, D.O.; Jasty, M.; Harris, W.H.

    1998-01-01

    The crosslink density of a polyethylene network structure can be determined by swelling in hot xylene (130 deg C). The Flory's swelling theory is generally used to calculate the crosslink density, dx (ln(l-q -1 )+q -1 +Xq -1 )/(V 1 q -1/3 ), where V 1 is the molar volume of xylene at 130 deg C (136 cc/mol), X is the xylene-polyethylene interaction parameter, and q is the equilibrium volume swelling ratio of cross-linked network in hot xylene. Conventionally, q is measured using gravimetric methods as described in ASTM D2765-95. However, as noted in the ASTM standard, the gravimetric method has a large error factor associated with the measurement of q (as much as 100%). UHMWPE was irradiated (range of 25 to 300 kGy) using an AECL I 10/1 linear electron beam accelerator operated at 1 kW. The irradiated specimens were subsequently melt-annealed at 150 deg C for 2 hours in vacuum. For swelling experiments, 2 mm thin samples were machined using a diamond blade. The sample sizes were kept at around 3x3x2 mm and the bottom and top surfaces were machined parallel to each other. The equilibrium volume swelling ratios were determined using a Perkin-Elmer TMA/DMA 7 (n=3 for each radiation dose level). The samples were placed in a quartz basket-probe assembly and lowered into a xylene/antioxidant bath at room temperature. The xylene was then heated to 130 deg C at 5 deg C/min and held at 130 deg C for 2 hours. The swelling was then recorded with the upward motion of the probe until the equilibrium swelling was achieved. (The experiments were carried out in 3 orthogonal directions which confirmed the isotropy of swelling). (author)

  18. The effect of radiation dose on the crosslink density of ultra-high molecular weight polyethylene (UHMWPE) measured by a novel swelling method

    International Nuclear Information System (INIS)

    Muratoglu, O.K.; Bragdon, C.R.; O'Connor, D.O.; Jasty, M.; Harris, W.H.

    1998-01-01

    The crosslink density of a polyethylene network structure can be determined by swelling in hot xylene (130 deg C). The Flory's swelling theory is generally used to calculate the crosslink density, dx (ln(l-q -1 ) + q -1 + Xq -1 )/(V l q -1/3 ), where V l is the molar volume of xylene at 130 deg C (136 cc/mol), X is the xylene-polyethylene interaction parameter, and q is the equilibrium volume swelling ratio of cross-linked network in hot xylene. Conventionally, q is measured using gravimetric methods as described in ASTM D2765-95. However, as noted in the ASTM standard, the gravimetric method has a large error factor associated with the measurement of q (as much as 100%). UHMWPE was irradiated (range of 25 to 300 kGy) using an AECL I 10/1 linear electron beam accelerator operated at 1 kW. The irradiated specimens were subsequently melt-annealed at 150 deg C for 2 hours in vacuum. For swelling experiments, 2 mm thin samples were machined using a diamond blade. The sample sizes were kept at around 3x3x2 mm and the bottom and top surfaces were machined parallel to each other. The equilibrium volume swelling ratios were determined using a Perkin-Elmer TMA/DMA 7 (n=3 for each radiation dose level). The samples were placed in a quartz basket-probe assembly and lowered into a xylene/antioxidant bath at room temperature. The xylene was then heated to 130 deg C at 5 deg C/min and held at 130 deg C for 2 hours. The swelling was then recorded with the upward motion of the probe until the equilibrium swelling was achieved. (The experiments were carried out in 3 orthogonal directions which confirmed the isotropy of swelling). From this one-dimensional change in height, q was calculated by taking into account the volumetric expansion due to heating and melting. (author)

  19. Wood fibre density measurement with 238 Pu radiation

    International Nuclear Information System (INIS)

    Barry, B.J.; Baker, D.B.

    1996-01-01

    The form of the curve of attenuation by wood fibre of the X radiation from 238 Pu has been determined. An exponential function containing a term second order in the areal density of the fibre described the curve accurately. The effect of scatter is negligible, even with an uncollimated radiation beam. (author). 18 refs., 1 tab., 6 figs

  20. Dosimetry of high energy radiation

    CERN Document Server

    Sahare, P D

    2018-01-01

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

  1. Alpha radiation gauge for the measurement of gas density

    International Nuclear Information System (INIS)

    Lech, M.

    1977-01-01

    Alpha gauge for the measurement of gas density with thick alfa source, has been developed. The gauge is based on radiation transmission through a space filled with gas and total-count principle. Air density can be measured in the range 1,2 - 1,27 kg m -3 with a maximum standard deviation of 2 x 10 -3 kg m -3 . (author)

  2. Density meters utilizing ionizing radiation: definitions and test methods

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    This standard is applicable to density meters utilizing ionizing radiation, designed for the measurement of the density of liquids, slurries or fluidized solids. The standard applies to transmission-type instruments only. Reference to compliance with this standard shall identify any deviations and the reasons for such deviations. Safety aspects are not included but should fulfill the requirements of all relevant internationally accepted standards

  3. High density energy storage capacitor

    International Nuclear Information System (INIS)

    Whitham, K.; Howland, M.M.; Hutzler, J.R.

    1979-01-01

    The Nova laser system will use 130 MJ of capacitive energy storage and have a peak power capability of 250,000 MW. This capacitor bank is a significant portion of the laser cost and requires a large portion of the physical facilities. In order to reduce the cost and volume required by the bank, the Laser Fusion Program funded contracts with three energy storage capacitor producers: Aerovox, G.E., and Maxwell Laboratories, to develop higher energy density, lower cost energy storage capacitors. This paper describes the designs which resulted from the Aerovox development contract, and specifically addresses the design and initial life testing of a 12.5 kJ, 22 kV capacitor with a density of 4.2 J/in 3 and a projected cost in the range of 5 cents per joule

  4. High-current discharge channel contraction in high density gas

    International Nuclear Information System (INIS)

    Rutberg, Ph. G.; Bogomaz, A. A.; Pinchuk, M. E.; Budin, A. V.; Leks, A. G.; Pozubenkov, A. A.

    2011-01-01

    Research results for discharges at current amplitudes of 0.5-1.6 MA and current rise rate of ∼10 10 A/s are presented. The discharge is performed in the hydrogen environment at the initial pressure of 5-35 MPa. Initiation is implemented by a wire explosion. The time length of the first half-period of the discharge current is 70-150 μs. Under such conditions, discharge channel contraction is observed; the contraction is followed by soft x-ray radiation. The phenomena are discussed, which are determined by high density of the gas surrounding the discharge channel. These phenomena are increase of the current critical value, where the channel contraction begins and growth of temperature in the axis region of the channel, where the initial density of the gas increases.

  5. High-density lipoprotein cholesterol: How High

    Directory of Open Access Journals (Sweden)

    G Rajagopal

    2012-01-01

    Full Text Available The high-density lipoprotein cholesterol (HDL-C is considered anti-atherogenic good cholesterol. It is involved in reverse transport of lipids. Epidemiological studies have found inverse relationship of HDL-C and coronary heart disease (CHD risk. When grouped according to HDL-C, subjects having HDL-C more than 60 mg/dL had lesser risk of CHD than those having HDL-C of 40-60 mg/dL, who in turn had lesser risk than those who had HDL-C less than 40 mg/dL. No upper limit for beneficial effect of HDL-C on CHD risk has been identified. The goals of treating patients with low HDL-C have not been firmly established. Though many drugs are known to improve HDL-C concentration, statins are proven to improve CHD risk and mortality. Cholesteryl ester transfer protein (CETP is involved in metabolism of HDL-C and its inhibitors are actively being screened for clinical utility. However, final answer is still awaited on CETP-inhibitors.

  6. Study of the antioxidant effect of {alpha}-tocopherol on low-density lipoprotein peroxidation induced at low and high {gamma}-radiation dose rates

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Abdelouahed [Research Centre on Aging and Department of Medicine, University of Sherbrooke, Sherbrooke, QC, J1H 4C4 (Canada)]. E-mail: abdelouahed.khalil@usherbrooke.ca; Milochevitch, Christelle [Research Centre on Aging and Department of Medicine, University of Sherbrooke, Sherbrooke, QC, J1H 4C4 (Canada)

    2005-02-01

    It is well known that vitamin E ({alpha}-tocopherol, {alpha}-toc) is a very efficient lipid soluble antioxidant and several studies showed its beneficial action in the prevention and reduction of atherosclerosis. However, some in vitro studies suggest a prooxidant role of vitamin E, which could occur under given circumstances. This study was thus designed to investigate the antioxidant vs. prooxidant effect of vitamin E with regards to LDL peroxidation induced under different oxidative stress conditions. LDL was enriched with {alpha}-tocopherol and different {alpha}-toc/LDL ratios were studied (8.0{+-}2.5, 14.3{+-}3.0, 33.3{+-}3.7, 42.7{+-}3.5 and 48.2{+-}4.5 molecules of {alpha}-toc/LDL particle). Enriched and control LDL were oxidized by action of {sup {center_dot}}OH and O{sub 2}{sup {center_dot}}{sup -} free radicals produced by {gamma}-radiolysis at different dose rates. Susceptibility of LDL to oxidation was examined by the measure of conjugated diene and TBARS formation as well as LDL endogenous {alpha}-toc disappearance. Increasing LDL {alpha}-toc concentration reduced the LDL susceptibility to oxidation and their oxidizability. {alpha}-toc disappearance rates were comprised between 43 and 8.3x10{sup -10} M s{sup -1} and decreased with the radiation dose rate. Our results support an antioxidant role for {alpha}-tocopherol at high and low oxidative stress conditions.

  7. Study of the antioxidant effect of α-tocopherol on low-density lipoprotein peroxidation induced at low and high γ-radiation dose rates

    International Nuclear Information System (INIS)

    Khalil, Abdelouahed; Milochevitch, Christelle

    2005-01-01

    It is well known that vitamin E (α-tocopherol, α-toc) is a very efficient lipid soluble antioxidant and several studies showed its beneficial action in the prevention and reduction of atherosclerosis. However, some in vitro studies suggest a prooxidant role of vitamin E, which could occur under given circumstances. This study was thus designed to investigate the antioxidant vs. prooxidant effect of vitamin E with regards to LDL peroxidation induced under different oxidative stress conditions. LDL was enriched with α-tocopherol and different α-toc/LDL ratios were studied (8.0±2.5, 14.3±3.0, 33.3±3.7, 42.7±3.5 and 48.2±4.5 molecules of α-toc/LDL particle). Enriched and control LDL were oxidized by action of · OH and O 2 ·- free radicals produced by γ-radiolysis at different dose rates. Susceptibility of LDL to oxidation was examined by the measure of conjugated diene and TBARS formation as well as LDL endogenous α-toc disappearance. Increasing LDL α-toc concentration reduced the LDL susceptibility to oxidation and their oxidizability. α-toc disappearance rates were comprised between 43 and 8.3x10 -10 M s -1 and decreased with the radiation dose rate. Our results support an antioxidant role for α-tocopherol at high and low oxidative stress conditions

  8. States of high energy density

    International Nuclear Information System (INIS)

    Murray, M.

    1988-02-01

    The transverse energy, E/sub tau/ spectra for O 16 and S 32 incident for various elements at 200 GeVnucleon are shown. The target and projectile dependencies of the data are discussed. The energy density achieved is estimated. For O 16 on Tungsten the multiplicity spectrum is also presented as well as the pseudorapidity spectra as a function of the transverse energy. The multiplicity cross section dσdN as measured in the backward hemisphere (0.9 < /eta/ < 2.9/ is found to be very similar in shape to the transverse energy distribution dσdE/tau/ reflecting the particular geometry of nucleus nucleus nucleus collisions. The dependence on the atomic mass of the target, A/sub tau/ and projectile A/sub p/ is not what one would expect from naive considerations

  9. High density harp for SSCL linac

    International Nuclear Information System (INIS)

    Fritsche, C.T.; Krogh, M.L.; Crist, C.E.

    1993-01-01

    AlliedSignal Inc., Kansas City Division, and the Superconducting Super Collider Laboratory (SSCL) are collaboratively developing a high density harp for the SSCL linac. This harp is designed using hybrid microcircuit (HMC) technology to obtain a higher wire density than previously available. The developed harp contains one hundred twenty-eight 33-micron-diameter carbon wires on 0.38-mm centers. The harp features an onboard broken wire detection circuit. Carbon wire preparation and attachment processes were developed. High density surface mount connectors were located. The status of high density harp development will be presented along with planned future activities

  10. High density harp for SSCL linac

    International Nuclear Information System (INIS)

    Fritsche, C.T.; Krogh, M.L.

    1993-05-01

    AlliedSignal Inc., Kansas City Division, and the Superconducting Super Collider Laboratory (SSCL) are collaboratively developing a high density harp for the SSCL linac. This harp is designed using hybrid microcircuit (HMC) technology to obtain a higher wire density than previously available. The developed harp contains one hundred twenty-eight 33-micron-diameter carbon wires on 0.38-mm centers. The harp features an onboard broken wire detection circuit. Carbon wire preparation and attachment processes were developed. High density surface mount connectors were located. The status of high density harp development will be presented along with planned future activities

  11. High density matter at RHIC

    Indian Academy of Sciences (India)

    are screened, and short range (high momentum) interactions are weak, leading to an ideal gas equation .... I will briefly touch on 'soft physics' ..... thermodynamic concepts to describe multi-particle production has a long history beginning with ...

  12. Positron camera with high-density avalanche chambers

    International Nuclear Information System (INIS)

    Manfrass, D.; Enghardt, W.; Fromm, W.D.; Wohlfarth, D.; Hennig, K.

    1988-01-01

    The results of an extensive investigation of the properties of high-density avalanche chambers (HIDAC) are presented. This study has been performed in order to optimize the layout of HIDAC detectors, since they are intended to be applied as position sensitive detectors for annihilation radiation in a positron emission tomograph being under construction. (author)

  13. Electronic DC transformer with high power density

    NARCIS (Netherlands)

    Pavlovský, M.

    2006-01-01

    This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

  14. New aspects of high energy density plasma

    International Nuclear Information System (INIS)

    Hotta, Eiki

    2005-10-01

    The papers presented at the symposium on 'New aspects of high energy density plasma' held at National Institute for Fusion Science are collected in this proceedings. The papers reflect the present status and recent progress in the experiments and theoretical works on high energy density plasma produced by pulsed power technology. The 13 of the presented papers are indexed individually. (J.P.N.)

  15. High regression rate, high density hybrid fuels, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR program will investigate high energy density novel nanofuels combined with high density binders for use with an N2O oxidizer. Terves has developed...

  16. Magnetization of High Density Hadronic Fluid

    DEFF Research Database (Denmark)

    Bohr, Henrik; Providencia, Constanca; da Providencia, João

    2012-01-01

    In the present paper the magnetization of a high density relativistic fluid of elementary particles is studied. At very high densities, such as may be found in the interior of a neutron star, when the external magnetic field is gradually increased, the energy of the normal phase of the fluid...... in the particle fluid. For nuclear densities above 2 to 3 rho(0), where rho(0) is the equilibrium nuclear density, the resulting magnetic field turns out to be rather huge, of the order of 10(17) Gauss....

  17. High energy density lithium batteries

    CERN Document Server

    Aifantis, Katerina E; Kumar, R Vasant

    2010-01-01

    Cell phones, portable computers and other electronic devices crucially depend on reliable, compact yet powerful batteries. Therefore, intensive research is devoted to improving performance and reducing failure rates. Rechargeable lithium-ion batteries promise significant advancement and high application potential for hybrid vehicles, biomedical devices, and everyday appliances. This monograph provides special focus on the methods and approaches for enhancing the performance of next-generation batteries through the use of nanotechnology. Deeper understanding of the mechanisms and strategies is

  18. Radiation distribution sensor with optical fibers for high radiation fields

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  19. Frontiers for Discovery in High Energy Density Physics

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, R. C.; Katsouleas, T.; Arons, J.; Baring, M.; Deeney, C.; Di Mauro, L.; Ditmire, T.; Falcone, R.; Hammer, D.; Hill, W.; Jacak, B.; Joshi, C.; Lamb, F.; Lee, R.; Logan, B. G.; Melissinos, A.; Meyerhofer, D.; Mori, W.; Murnane, M.; Remington, B.; Rosner, R.; Schneider, D.; Silvera, I.; Stone, J.; Wilde, B.; Zajc. W.

    2004-07-20

    The report is intended to identify the compelling research opportunities of high intellectual value in high energy density physics. The opportunities for discovery include the broad scope of this highly interdisciplinary field that spans a wide range of physics areas including plasma physics, laser and particle beam physics, nuclear physics, astrophysics, atomic and molecular physics, materials science and condensed matter physics, intense radiation-matter interaction physics, fluid dynamics, and magnetohydrodynamics

  20. Some recent efforts toward high density implosions

    International Nuclear Information System (INIS)

    McClellan, G.E.

    1980-01-01

    Some recent Livermore efforts towards achieving high-density implosions are presented. The implosion dynamics necessary to compress DT fuel to 10 to 100 times liquid density are discussed. Methods of diagnosing the maximum DT density for a specific design are presented along with results to date. The dynamics of the double-shelled target with an exploding outer shell are described, and some preliminary experimental results are presented

  1. Local thermodynamic equilibrium in rapidly heated high energy density plasmas

    International Nuclear Information System (INIS)

    Aslanyan, V.; Tallents, G. J.

    2014-01-01

    Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance

  2. Research on high energy density plasmas and applications

    International Nuclear Information System (INIS)

    1999-01-01

    Recently, technologies on lasers, accelerators, and pulse power machines have been significantly advanced and input power density covers the intensity range from 10 10 W/cm 2 to higher than 10 20 W/cm 2 . As the results, high pressure gas and solid targets can be heated up to very high temperature to create hot dense plasmas which have never appeared on the earth. The high energy density plasmas opened up new research fields such as inertial confinement fusion, high brightness X-ray radiation sources, interiors of galactic nucleus,supernova, stars and planets, ultra high pressure condensed matter physics, plasma particle accelerator, X-ray laser, and so on. Furthermore, since these fields are intimately connected with various industrial sciences and technologies, the high energy density plasma is now studied in industries, government institutions, and so on. This special issue of the Journal of Plasma Physics and Nuclear Fusion Research reviews the high energy density plasma science for the comprehensive understanding of such new fields. In May, 1998, the review committee for investigating the present status and the future prospects of high energy density plasma science was established in the Japan Society of Plasma Science and Nuclear Fusion Research. We held three committee meetings to discuss present status and critical issues of research items related to high energy density plasmas. This special issue summarizes the understandings of the committee. This special issue consists of four chapters: They are Chapter 1: Physics important in the high energy density plasmas, Chapter 2: Technologies related to the plasma generation; drivers such as lasers, pulse power machines, particle beams and fabrication of various targets, Chapter 3: Plasma diagnostics important in high energy density plasma experiments, Chapter 4: A variety of applications of high energy density plasmas; X-ray radiation, particle acceleration, inertial confinement fusion, laboratory astrophysics

  3. High Energy Density Polymer Film Capacitors

    National Research Council Canada - National Science Library

    Boufelfel, Ali

    2006-01-01

    High-energy-density capacitors that are compact and light-weight are extremely valuable in a number of critical DoD systems that include portable field equipment, pulsed lasers, detection equipment...

  4. Modelling high density phenomena in hydrogen fibre Z-pinches

    International Nuclear Information System (INIS)

    Chittenden, J.P.

    1990-09-01

    The application of hydrogen fibre Z-pinches to the study of the radiative collapse phenomenon is studied computationally. Two areas of difficulty, the formation of a fully ionized pinch from a cryogenic fibre and the processes leading to collapse termination, are addressed in detail. A zero-D model based on the energy equation highlights the importance of particle end losses and changes in the Coulomb logarithm upon collapse initiation and termination. A 1-D Lagrangian resistive MHD code shows the importance of the changing radial profile shapes, particularly in delaying collapse termination. A 1-D, three fluid MHD code is developed to model the ionization of the fibre by thermal conduction from a high temperature surface corona to the cold core. Rate equations for collisional ionization, 3-body recombination and equilibration are solved in tandem with fluid equations for the electrons, ions and neutrals. Continuum lowering is found to assist ionization at the corona-core interface. The high density plasma phenomena responsible for radiative collapse termination are identified as the self-trapping of radiation and free electron degeneracy. A radiation transport model and computational analogues for the effects of degeneracy upon the equation of state, transport coefficients and opacity are implemented in the 1-D, single fluid model. As opacity increases the emergent spectrum is observed to become increasingly Planckian and a fall off in radiative cooling at small radii and low frequencies occurs giving rise to collapse termination. Electron degeneracy terminates radiative collapse by supplementing the radial pressure gradient until the electromagnetic pinch force is balanced. Collapse termination is found to be a hybrid process of opacity and degeneracy effects across a wide range of line densities with opacity dominant at large line densities but with electron degeneracy becoming increasingly important at lower line densities. (author)

  5. An investigation of pulsed high density plasmas

    International Nuclear Information System (INIS)

    Timmermans, C.J.

    1984-01-01

    In this thesis a wall-stabilized argon cascade arc is studied at values of pulsed pressure up to 14 bar and a pulsed current range up to 2200 A with a time duration of about 2 ms. The basic plasma is a CW cascade arc with a 5 mm diameter plasma column and a length of 90 mm, which operates at a 60 A DC current and at one atmosphere filling pressure. The author starts with an extensive summary of the CW arc investigations. After a brief introduction of the basic transport equations the mass equations of the constituent particles are treated using the extended collisional radiative model. The energy balance equations and the momentum balance are discussed. The electron density is determined from measurements of the continuum radiation. The final chapter contains the experimental results on the electron temperatures and electron densities in the pressure and current pulsed plasma. Attention is given to the deviations from local thermodynamic equilibrium values of the ground level densities of the different argon systems. (Auth.)

  6. Density determination of railroad ballast by means of gamma radiation

    International Nuclear Information System (INIS)

    Mundt, M.

    1983-01-01

    Proceeding from the requirements of a measuring method for determining the degrees of densification and of soiling of railroad beds, conclusions are drawn for the use of a radiometric technique, considering measuring geometry, radiation energy, and instrumentation. Results obtained from laboratory experiments with a ballast pressure unit are presented. It is pointed out that the application of radiometric density measurements has to be linked with investigations of the behaviour of the rock species used, in order to obtain a valid interpretation of the measured density with regard to the properties and the composition of the railroad bed. (author)

  7. Relationship of cancer incidence to terrestrial radiation and population density in Connecticut, 1935-1974

    International Nuclear Information System (INIS)

    Walter, S.D.; Meigs, J.W.; Heston, J.F.

    1986-01-01

    The relationship of cancer incidence to terrestrial radiation and population density was investigated. Cancer incidence was obtained using 40 years of age-standardized data from the Connecticut Tumor Registry, and environmental radiation was estimated using data from an airborne gamma radiation survey of the entire state. These variables were examined ecologically, using the 169 towns of the state as the analytic units in a weighted regression analysis. The study design involves a large population base in a state having relatively high terrestrial radiation exposure levels overall and reasonable variation in exposure between towns. For all cancer combined, only one of the eight sex-specific analyses by decade yielded a significant radiation regression coefficient, and this was negative. In the sex- and site-specific analyses, almost all the coefficients for radiation were not significantly different from zero. In contrast, significant positive relationships of cancer incidence with population density were found for all cancer, for cancer of the lung for both sexes, for stomach, colonic, and prostatic cancer for males, and for lymphomas, thyroid, breast, and ovarian cancer for females. Both the radiation and population density relationships were adjusted for socioeconomic status. Socioeconomic status was significantly negatively associated with stomach and lung cancer in males and with cervical cancer in females; it was also positively associated with lymphomas and breast cancer in females. A power calculation revealed that, despite the relatively large size of this study, there was only a small probability of detecting a radiation effect of the strength anticipated from previous estimates

  8. High-density limit of quantum chromodynamics

    International Nuclear Information System (INIS)

    Alvarez, E.

    1983-01-01

    By means of a formal expansion of the partition function presumably valid at large baryon densities, the propagator of the quarks is expressed in terms of the gluon propagator. This result is interpreted as implying that correlations between quarks and gluons are unimportant at high enough density, so that a kind of mean-field approximation gives a very accurate description of the physical system

  9. Density measurement using gamma radiation - theory and application

    International Nuclear Information System (INIS)

    Springer, E.K.

    1979-01-01

    There are still widespread uncertainties about the use and safety of gamma radiation in industries. This paper describes, by the example of radiometric density measurement, the theory of gamma radiation. The differences and advantages of both types of detectors, the ionization chamber and the scintillation counter, are discussed. The degree of accuracy which can be expected from the radiometric density meter will be defined, and the inter-relationship: source strength - measuring range - measuring length(normally the pipe diameter) in relation to the measuring accuracy required will be explained in detail. The use of radioactive material requires the permission of the Atomic Energy Board. The formalities involved to receive a user's licence and the implementations of safety standards set by the local authorities are discussed in depth [af

  10. High density data recording for SSCL linac

    International Nuclear Information System (INIS)

    VanDeusen, A.L.; Crist, C.

    1993-01-01

    The Superconducting Super Collider Laboratory and AlliedSignal Aerospace have collaboratively developed a high density data monitoring system for beam diagnostic activities. The 128 channel data system is based on a custom multi-channel high speed digitizer card for the VXI bus. The card is referred to as a Modular Input VXI (MIX) digitizer. Multiple MIX cards are used in the complete system to achieve the necessary high channel density requirements. Each MIX digitizer card also contains programmable signal conditioning, and enough local memory to complete an entire beam scan without assistance from the host processor

  11. High-let radiation carcinogenesis

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  12. AMODS and High Energy Density Sciences

    International Nuclear Information System (INIS)

    Rhee, Y.-J.

    2011-01-01

    Following a brief introduction to the Lab for Quantum Optics (LFQO) in KAERI, which has been devoted to the research on atomic spectroscopy for more than 20 years with precision measurement of atomic parameters such as isotope shift, hyperfine structures, autoionization levels and so on as well as with theoretical analysis of atomic systems by developing relativistic calculation methodologies for laser propagation and population dynamics, electron impact ionization, radiative transitions of high Z materials, etc for the application to isotope separation, the AMODS (Atomic Molecular and Optical Database Systems) which was established in 1997 and has been a member of International Data Center Network of IAEA since then is explained by giving an information on the data sources and internal structure of the compilation of AMODS. Since AMODS was explained in detail during last DCN meeting, just a brief introduction is given this time. Then more specific research themes carried out in LFQO in conjunction with A+M data are discussed, including (1) electron impact ionization processes of W, Mo, Be, C, etc, (2) spectra of highly charged ions of W, Xe, and Si, (3) dielectronic recombination process of Fe ion. Also given are the talk about research activities about the simulations of high energy density experiments such as those performed at (1) GEKKO laser facility (Japan) for X-ray photoionization of low temperature Si plasma, which can explain the unsolved arguments on the X-ray spectra of black holes and/or neutron stars, (2) VULCAN laser facility (UK) for two dimensional compression of cylindrical target and investigation of hot electron transport in the compressed target plasma to understand the fast ignition process of laser fusion, (3) LULI laser facility (France) and TITAN laser facility (USA) for one dimensional compression of aluminum targets with different laser energies, and (4) PALS facility (Czech Republic) for 'Laser Induced Cavity Pressure Acceleration' to

  13. Profiles of radiation power density in WEGA stellarator

    International Nuclear Information System (INIS)

    Zhang, D.; Otte, M.; Giannone, L.

    2005-01-01

    On the WEGA stellarator, a 12 channel bolometer camera has been used to measure the radiation power losses of the plasma, which is heated by ECR at 2.45 GHz with a maximum power of 26 kW. The typical electron temperatures achieved are around 10 eV. The bolometer is of the Au resistor type and is positioned on the mid-plane, viewing the plasma from the low-field side with a spatial resolution of about 6 cm. The viewing angle is opened to poloidally (±47 o ) and covers the whole cross-section. Angular profiles of radiation power density (emissivity) can be achieved using the measured fluxes to the channels, which are given by the integrals along the sight lines. Using Abel inversion with maximum entropy regularisation, radial profiles of emissivity could be obtained. It is found that the angular profile of emissivity depends on the magnetic configuration, the working gas (Ar, He) and the heating scenario. Peaked and hollow emissivity profiles have been obtained by using different types of heating antenna. By changing the magnetic configuration, strong edge radiation has been observed. The largest emissivity values are obtained in the upper SOL range of Ar-discharges. This edge radiation can be reduced by shifting the flux surfaces inwards or by changing their shape at the antenna. The reconstruction of the radial profile of the emissivity was carried out in the case of a peaked angular profile with minimum edge radiation. The total radiation power was estimated by linear extrapolation of the integrated radiation power in the viewing region to the torus volume. It is typically less than 30% of the ECRH input power, but depending on the ECRH input power, again the magnetic configuration, the working gas as well as the absolute field strength on the magnetic axis. Maximum radiation losses have been obtained around 0.6·B0, where B 0 =87.5 mT is the resonant field strength of the ECRH. No evidence for impurities was obtained from spectroscopic measurements, and thus the

  14. High Density Digital Data Storage System

    Science.gov (United States)

    Wright, Kenneth D., II; Gray, David L.; Rowland, Wayne D.

    1991-01-01

    The High Density Digital Data Storage System was designed to provide a cost effective means for storing real-time data from the field-deployable digital acoustic measurement system. However, the high density data storage system is a standalone system that could provide a storage solution for many other real time data acquisition applications. The storage system has inputs for up to 20 channels of 16-bit digital data. The high density tape recorders presently being used in the storage system are capable of storing over 5 gigabytes of data at overall transfer rates of 500 kilobytes per second. However, through the use of data compression techniques the system storage capacity and transfer rate can be doubled. Two tape recorders have been incorporated into the storage system to produce a backup tape of data in real-time. An analog output is provided for each data channel as a means of monitoring the data as it is being recorded.

  15. High current density magnets for INTOR and TIBER

    International Nuclear Information System (INIS)

    Miller, J.R.; Henning, C.D.; Kerns, J.A.; Slack, D.S.; Summers, L.T.; Zbasnik, J.P.

    1986-12-01

    The adoption of high current density, high field, superconducting magnets for INTOR and TIBER would prove beneficial. When combined with improved radiation tolerance of the magnets to minimize the inner leg shielding, a substantial reduction in machine dimensions and capital costs can be achieved. Fortunately, cable-in-conduit conductors (CICC) which are capable of the desired enhancements are being developed. Because conductor stability in a CICC depends more on the trapped helium enthalpy, rather than the copper resistivity, higher current densities of the order of 40 A/mm 2 at 12 T are possible. Radiation damage to the copper stabilizer is less important because the growth in resistance is a second-order effect on stability. Such CICC conductors lend themselves naturally to niobium-tin utilization, with the benefits of the high current-sharing temperature of this material being taken to advantage in absorbing radiation heating. When the helium coolant is injected at near the critical pressure, Joule-Thompson expansion in the flow path tends to stabilize the fluid temperature at under 6 K. Thus, higher fields, as well as higher current densities, can be considered for INTOR or TIBER

  16. High throughput nonparametric probability density estimation.

    Science.gov (United States)

    Farmer, Jenny; Jacobs, Donald

    2018-01-01

    In high throughput applications, such as those found in bioinformatics and finance, it is important to determine accurate probability distribution functions despite only minimal information about data characteristics, and without using human subjectivity. Such an automated process for univariate data is implemented to achieve this goal by merging the maximum entropy method with single order statistics and maximum likelihood. The only required properties of the random variables are that they are continuous and that they are, or can be approximated as, independent and identically distributed. A quasi-log-likelihood function based on single order statistics for sampled uniform random data is used to empirically construct a sample size invariant universal scoring function. Then a probability density estimate is determined by iteratively improving trial cumulative distribution functions, where better estimates are quantified by the scoring function that identifies atypical fluctuations. This criterion resists under and over fitting data as an alternative to employing the Bayesian or Akaike information criterion. Multiple estimates for the probability density reflect uncertainties due to statistical fluctuations in random samples. Scaled quantile residual plots are also introduced as an effective diagnostic to visualize the quality of the estimated probability densities. Benchmark tests show that estimates for the probability density function (PDF) converge to the true PDF as sample size increases on particularly difficult test probability densities that include cases with discontinuities, multi-resolution scales, heavy tails, and singularities. These results indicate the method has general applicability for high throughput statistical inference.

  17. Supernovae and high density nuclear matter

    International Nuclear Information System (INIS)

    Kahana, S.

    1986-01-01

    The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs

  18. Supernovae and high density nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Kahana, S.

    1986-01-01

    The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs.

  19. High density implosion experiments at Nova

    International Nuclear Information System (INIS)

    Cable, M.D.; Hatchett, S.P.; Nelson, M.B.; Lerche, R.A.; Murphy, T.J.; Ress, D.B.

    1994-01-01

    Deuterium filled glass microballoons are used as indirectly driven targets for implosion experiments at the Nova Laser Fusion Facility. High levels of laser precision were required to achieve fuel densities and convergences to an ignition scale hot spot. (AIP) copyright 1994 American Institute of Physics

  20. High Density GEOSAT/GM Altimeter Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The high density Geosat/GM altimeter data south of 30 S have finally arrived. In addition, ERS-1 has completed more than 6 cycles of its 35-day repeat track. These...

  1. High density aseismic spent fuel storage racks

    International Nuclear Information System (INIS)

    Louvat, J.P.

    1985-05-01

    After the reasons of the development of high density aseismic spent fuel racks by FRAMATOME and LEMER, a description is presented, as also the codes, standards and regulations used to design this FRAMATOME storage rack. Tests have been carried out concerning criticality, irradiation of Cadminox, corrosion of the cell, and the seismic behaviour

  2. Models for Experimental High Density Housing

    Science.gov (United States)

    Bradecki, Tomasz; Swoboda, Julia; Nowak, Katarzyna; Dziechciarz, Klaudia

    2017-10-01

    The article presents the effects of research on models of high density housing. The authors present urban projects for experimental high density housing estates. The design was based on research performed on 38 examples of similar housing in Poland that have been built after 2003. Some of the case studies show extreme density and that inspired the researchers to test individual virtual solutions that would answer the question: How far can we push the limits? The experimental housing projects show strengths and weaknesses of design driven only by such indexes as FAR (floor attenuation ratio - housing density) and DPH (dwellings per hectare). Although such projects are implemented, the authors believe that there are reasons for limits since high index values may be in contradiction to the optimum character of housing environment. Virtual models on virtual plots presented by the authors were oriented toward maximising the DPH index and DAI (dwellings area index) which is very often the main driver for developers. The authors also raise the question of sustainability of such solutions. The research was carried out in the URBAN model research group (Gliwice, Poland) that consists of academic researchers and architecture students. The models reflect architectural and urban regulations that are valid in Poland. Conclusions might be helpful for urban planners, urban designers, developers, architects and architecture students.

  3. Collision density approach of radiation damage in a multispecies medium

    International Nuclear Information System (INIS)

    Lux, I.; Pazsit, I.

    1981-01-01

    Space-energy dependent forward type equations for the collision densities of energetic atoms in a multispecies semi-infinite homogeneous medium are formulated. Introduction of the one-dimensional isotropic forward-backward model of Fermi for the scattering and application of the Laplace transform with respect to the lethargy variable will lead to a linear differential equation system with constant coefficients. This equation system is solved for an arbitrary number of species and relations between the collision densities and defect distributions of the different species are given in the Kinchin-Pease model of radiation damage. The case of an alien particle incident on a two-component target is examined in some detail and the sputtering spectra for the three species are given numerically. (author)

  4. Collision density approach of radiation damage in a multispecies medium

    Energy Technology Data Exchange (ETDEWEB)

    Lux, I; Pazsit, I [Koezponti Elelmiszeripari Kutato Intezet, Budapest (Hungary)

    1981-01-01

    Space-energy dependent forward type equations for the collision densities of energetic atoms in a multispecies semi-infinite homogeneous medium are formulated. Introduction of the one-dimensional isotropic forward-backward model of Fermi for the scattering and application of the Laplace transform with respect to the lethargy variable will lead to a linear differential equation system with constant coefficients. This equation system is solved for an arbitrary number of species and relations between the collision densities and defect distributions of the different species are given in the Kinchin-Pease model of radiation damage. The case of an alien particle incident on a two-component target is examined in some detail and the sputtering spectra for the three species are given numerically.

  5. Determining the temperature and density distribution from a Z-pinch radiation source

    International Nuclear Information System (INIS)

    Matuska, W.; Lee, H.

    1997-01-01

    High temperature radiation sources exceeding one hundred eV can be produced via z-pinches using currently available pulsed power. The usual approach to compare the z-pinch simulation and experimental data is to convert the radiation output at the source, whose temperature and density distributions are computed from the 2-D MHD code, into simulated data such as a spectrometer reading. This conversion process involves a radiation transfer calculation through the axially symmetric source, assuming local thermodynamic equilibrium (LTE), and folding the radiation that reaches the detector with the frequency-dependent response function. In this paper the authors propose a different approach by which they can determine the temperature and density distributions of the radiation source directly from the spatially resolved spectral data. This unfolding process is reliable and unambiguous for the ideal case where LTE holds and the source is axially symmetric. In reality, imperfect LTE and axial symmetry will introduce inaccuracies into the unfolded distributions. The authors use a parameter optimization routine to find the temperature and density distributions that best fit the data. They know from their past experience that the radiation source resulting from the implosion of a thin foil does not exhibit good axial symmetry. However, recent experiments carried out at Sandia National Laboratory using multiple wire arrays were very promising to achieve reasonably good symmetry. For these experiments the method will provide a valuable diagnostic tool

  6. Use of a high density lead glass tubing projection chamber in positron emission tomography and in high energy physics

    International Nuclear Information System (INIS)

    Conti, M.; Guerra, A.D.; Habel, R.; Mulera, T.; Perez-Mendez, V.; Schwartz, G.

    1985-10-01

    We describe the principle of operation of a high density Projection Chamber, in which the converter/radiator and drift field shaping structures are combined in the form of high density (5 to 6 g/cm 3 ) lead glass tubing. The main applications of this type of detector to Medical Physics (Positron Emission Tomography) and High Energy Physics (Electromagnetic Calorimetry) are discussed

  7. Quantum Phenomena in High Energy Density Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Murnane, Margaret [Univ. of Colorado, Boulder, CO (United States); Kapteyn, Henry [Univ. of Colorado, Boulder, CO (United States)

    2017-05-10

    The possibility of implementing efficient (phase matched) HHG upconversion of deep- UV lasers in multiply-ionized plasmas, with potentially unprecedented conversion efficiency is a fascinating prospect. HHG results from the extreme nonlinear response of matter to intense laser light:high harmonics are radiated as a result of a quantum coherent electron recollision process that occurs during laser field ionization of an atom. Under current support from this grant in work published in Science in 2015, we discovered a new regime of bright HHG in highly-ionized plasmas driven by intense UV lasers, that generates bright harmonics to photon energies >280eV

  8. Framatome offers new high density Cadminox racks

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Framatome have developed a new material called Cadminox for use in high density spent fuel storage racks. It is claimed that Cadminox will remain stable stable in pond storage when racks submerged in boronated water are irradiated by the spent fuel they contain. A brief description of the storage module is given, including the aseismic bearing device which minimises loads on pond walls, racks and fuel assemblies. (UK)

  9. Spin polarization in high density quark matter

    DEFF Research Database (Denmark)

    Bohr, Henrik; Panda, Prafulla K.; Providênci, Constanca

    2013-01-01

    We investigate the occurrence of a ferromagnetic phase transition in high density hadronic matter (e.g., in the interior of a neutron star). This could be induced by a four-fermion interaction analogous to the one which is responsible for chiral symmetry breaking in the Nambu-Jona-Lasinio model, ...... the so-called 2 flavor super-conducting phase to the ferromagnetic phase arises. The color-flavor-locked phase may be completely hidden by the FP....

  10. The car parking problem at high densities

    Science.gov (United States)

    Burgos, E.; Bonadeo, H.

    1989-04-01

    The radial distribution functions of random 1-D systems of sequential hard rods have been studied in the range of very high densities. It is found that as the number of samples rejected before completion increases, anomalies in the pairwise distribution functions arise. These are discussed using analytical solutions for systems of three rods and numerical simulations with twelve rods. The probabilities of different spatial orderings with respect to the sequential order are examined.

  11. Density ratios in compressions driven by radiation pressure

    International Nuclear Information System (INIS)

    Lee, S.

    1988-01-01

    It has been suggested that in the cannonball scheme of laser compression the pellet may be considered to be compressed by the 'brute force' of the radiation pressure. For such a radiation-driven compression, an energy balance method is applied to give an equation fixing the radius compression ratio K which is a key parameter for such intense compressions. A shock model is used to yield specific results. For a square-pulse driving power compressing a spherical pellet with a specific heat ratio of 5/3, a density compression ratio Γ of 27 is computed. Double (stepped) pulsing with linearly rising power enhances Γ to 1750. The value of Γ is not dependent on the absolute magnitude of the piston power, as long as this is large enough. Further enhancement of compression by multiple (stepped) pulsing becomes obvious. The enhanced compression increases the energy gain factor G for a 100 μm DT pellet driven by radiation power of 10 16 W from 6 for a square pulse power with 0.5 MJ absorbed energy to 90 for a double (stepped) linearly rising pulse with absorbed energy of 0.4 MJ assuming perfect coupling efficiency. (author)

  12. HIGH DENSITY QCD WITH HEAVY-IONS

    CERN Multimedia

    The Addendum 1 to Volume 2 of the CMS Physics TDR has been published The Heavy-Ion analysis group completed the writing of a TDR summarizing the CMS plans in using heavy ion collisions to study high density QCD. The document was submitted to the LHCC in March and presented in the Open Session of the LHCC on May 9th. The study of heavy-ion physics at the LHC is promising to be very exciting. LHC will open a new energy frontier in ultra-relativistic heavy-ion physics. The collision energy of heavy nuclei at sNN = 5.5 TeV will be thirty times larger than what is presently available at RHIC. We will certainly probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research programme is to study the fundamental theory of the strong interaction - Quantum Chromodynamics (QCD) - in extreme conditions of temperature, density and parton momentum fraction (low-x). Such studies, with impressive experimental and theoretical advances in recent years thanks to the wealth of high-qua...

  13. Foldable, High Energy Density Lithium Ion Batteries

    Science.gov (United States)

    Suresh, Shravan

    Lithium Ion Batteries (LIBs) have become ubiquitous owing to its low cost, high energy density and, power density. Due to these advantages, LIBs have garnered a lot of attention as the primary energy storage devices in consumer electronics and electric vehicles. Recent advances in the consumer electronics research and, the drive to reduce greenhouse gases have created a demand for a shape conformable, high energy density batteries. This thesis focuses on the aforementioned two aspects of LIBs: (a) shape conformability (b) energy density and provides potential solutions to enhance them. This thesis is divided into two parts viz. (i) achieving foldability in batteries and, (ii) improving its energy density. Conventional LIBs are not shape conformable due to two limitations viz. inelasticity of metallic foils, and delamination of the active materials while bending. In the first part of the thesis (in Chapter 3), this problem is solved by replacing metallic current collector with Carbon Nanotube Macrofilms (CNMs). CNMs are superelastic films comprising of porous interconnected nanotube network. Using Molecular Dynamics (MD) simulation, we found that in the presence of an interconnected nanotube network CNMs can be fully folded. This is because the resultant stress due to bending and, the effective bending angle at the interface is reduced due to the network of nanotubes. Hence, unlike an isolated nanotube (which ruptures beyond 120 degrees of bending), a network of nanotubes can be completely folded. Thus, by replacing metallic current collector foils with CNMs, the flexibility limitation of a conventional LIB can be transcended. The second part of this thesis focusses on enhancing the energy density of LIBs. Two strategies adopted to achieve this goal are (a) removing the dead weight of the batteries, and (b) incorporating high energy density electrode materials. By incorporating CNMs, the weight of the batteries was reduced by 5-10 times due to low mass loading of

  14. High-Power-Density, High-Energy-Density Fluorinated Graphene for Primary Lithium Batteries

    Directory of Open Access Journals (Sweden)

    Guiming Zhong

    2018-03-01

    Full Text Available Li/CFx is one of the highest-energy-density primary batteries; however, poor rate capability hinders its practical applications in high-power devices. Here we report a preparation of fluorinated graphene (GFx with superior performance through a direct gas fluorination method. We find that the so-called “semi-ionic” C-F bond content in all C-F bonds presents a more critical impact on rate performance of the GFx in comparison with sp2 C content in the GFx, morphology, structure, and specific surface area of the materials. The rate capability remains excellent before the semi-ionic C-F bond proportion in the GFx decreases. Thus, by optimizing semi-ionic C-F content in our GFx, we obtain the optimal x of 0.8, with which the GF0.8 exhibits a very high energy density of 1,073 Wh kg−1 and an excellent power density of 21,460 W kg−1 at a high current density of 10 A g−1. More importantly, our approach opens a new avenue to obtain fluorinated carbon with high energy densities without compromising high power densities.

  15. High Density Lipoprotein and it's Dysfunction.

    Science.gov (United States)

    Eren, Esin; Yilmaz, Necat; Aydin, Ozgur

    2012-01-01

    Plasma high-density lipoprotein cholesterol(HDL-C) levels do not predict functionality and composition of high-density lipoprotein(HDL). Traditionally, keeping levels of low-density lipoprotein cholesterol(LDL-C) down and HDL-C up have been the goal of patients to prevent atherosclerosis that can lead to coronary vascular disease(CVD). People think about the HDL present in their cholesterol test, but not about its functional capability. Up to 65% of cardiovascular death cannot be prevented by putative LDL-C lowering agents. It well explains the strong interest in HDL increasing strategies. However, recent studies have questioned the good in using drugs to increase level of HDL. While raising HDL is a theoretically attractive target, the optimal approach remains uncertain. The attention has turned to the quality, rather than the quantity, of HDL-C. An alternative to elevations in HDL involves strategies to enhance HDL functionality. The situation poses an opportunity for clinical chemists to take the lead in the development and validation of such biomarkers. The best known function of HDL is the capacity to promote cellular cholesterol efflux from peripheral cells and deliver cholesterol to the liver for excretion, thereby playing a key role in reverse cholesterol transport (RCT). The functions of HDL that have recently attracted attention include anti-inflammatory and anti-oxidant activities. High antioxidant and anti-inflammatory activities of HDL are associated with protection from CVD.This review addresses the current state of knowledge regarding assays of HDL functions and their relationship to CVD. HDL as a therapeutic target is the new frontier with huge potential for positive public health implications.

  16. High Spectral Density Optical Communication Technologies

    CERN Document Server

    Nakazawa, Masataka; Miyazaki, Tetsuya

    2010-01-01

    The latest hot topics of high-spectral density optical communication systems using digital coherent optical fibre communication technologies are covered by this book. History and meaning of a "renaissance" of the technology, requirements to the Peta-bit/s class "new generation network" are also covered in the first part of this book. The main topics treated are electronic and optical devices, digital signal processing including forward error correction, modulation formats as well as transmission and application systems. The book serves as a reference to researchers and engineers.

  17. 5th International conference on High Energy Density Laboratory Astrophysics

    CERN Document Server

    Kyrala, G.A

    2005-01-01

    During the past several years, research teams around the world have developed astrophysics-relevant utilizing high energy-density facilities such as intense lasers and z-pinches. Research is underway in many areas, such as compressible hydrodynamic mixing, strong shock phenomena, radiation flow, radiative shocks and jets, complex opacities, equations o fstat, and relativistic plasmas. Beyond this current research and the papers it is producing, plans are being made for the application, to astrophysics-relevant research, of the 2 MJ National Ignition Facility (NIF) laser at Lawrence Livermore National Laboratory; the 600 kj Ligne d'Intergration Laser (LIL) and the 2 MJ Laser Megajoule (LMJ) in Bordeaux, France; petawatt-range lasers now under construction around the world; and current and future Z pinches. The goal of this conference and these proceedings is to continue focusing and attention on this emerging research area. The conference brought together different scientists interested in this emerging new fi...

  18. Constraining the cosmic radiation density due to lepton number

    International Nuclear Information System (INIS)

    Mangano, Gianpiero; Miele, Gennaro; Pastor, Sergio; Pisanti, Ofelia; Sarikas, Srdjan

    2013-01-01

    The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis is typically parameterized in terms of the effective number of neutrinos N eff , and it is a key parameters in cosmological models slightly more general than the successful minimal ΛCDM scenario. This quantity, in case of no extra degrees of freedom, depends upon the chemical potential and the temperature characterizing the three active neutrino distributions, as well as by their possible non-thermal features. We summarize here the results of a recent analysis to determine the BBN bound on N eff from primordial neutrino–antineutrino asymmetries, with a careful treatment of the dynamics of neutrino oscillations, and considering quite a wide range for the total lepton number in the neutrino sector, η ν =η ν e +η ν μ +η ν τ and the initial electron neutrino asymmetry η ν e in . Comparing these results with the forthcoming measurement of N eff by the Planck satellite will give insight on the nature of the radiation content of the universe

  19. Measurements relating fire radiative energy density and surface fuel consumption - RxCADRE 2011 and 2012

    Science.gov (United States)

    Andrew T. Hudak; Matthew B. Dickinson; Benjamin C. Bright; Robert L. Kremens; E. Louise Loudermilk; Joseph J. O' Brien; Benjamin S. Hornsby; Roger D. Ottmar

    2016-01-01

    Small-scale experiments have demonstrated that fire radiative energy is linearly related to fuel combusted but such a relationship has not been shown at the landscape level of prescribed fires. This paper presents field and remotely sensed measures of pre-fire fuel loads, consumption, fire radiative energy density (FRED) and fire radiative power flux density (FRFD),...

  20. High-density hybrid interconnect methodologies

    International Nuclear Information System (INIS)

    John, J.; Zimmermann, L.; Moor, P.De; Hoof, C.Van

    2003-01-01

    Full text: The presentation gives an overview of the state-of-the-art of hybrid integration and in particular the IMEC technological approaches that will be able to address future hybrid detector needs. The dense hybrid flip-chip integration of an array of detectors and its dedicated readout electronics can be achieved with a variety of solderbump techniques such as pure Indium or Indium alloys, Ph-In, Ni/PbSn, but also conducting polymers... Particularly for cooled applications or ultra-high density applications, Indium solderbump technology (electroplated or evaporated) is the method of choice. The state-of-the-art of solderbump technologies that are to a high degree independent of the underlying detector material will be presented and examples of interconnect densities between 5x1E4cm-2 and 1x1E6 cm-2 will be demonstrated. For several classes of detectors, flip-chip integration is not allowed since the detectors have to be illuminated from the top. This applies to image sensors for EUV applications such as GaN/AlGaN based detectors and to MEMS-based sensors. In such cases, the only viable interconnection method has to be through the (thinned) detector wafer followed by a solderbump-based integration. The approaches for dense and ultra-dense through-the-wafer interconnect 'vias' will be presented and wafer thinning approaches will be shown

  1. Plasma Diagnostics in High Density Reactors

    International Nuclear Information System (INIS)

    Daltrini, A. M.; Moshkalyov, S.; Monteiro, M. J. R.; Machida, M.; Kostryukov, A.; Besseler, E.; Biasotto, C.; Diniz, J. A.

    2006-01-01

    Langmuir electric probes and optical emission spectroscopy diagnostics were developed for applications in high density plasmas. These diagnostics were employed in two plasma sources: an electron cyclotron resonance (ECR) plasma and an RF driven inductively coupled plasma (ICP) plasma. Langmuir probes were tested using a number of probing dimensions, probe tip materials, circuits for probe bias and filters. Then, the results were compared with the optical spectroscopy measurements. With these diagnostics, analyses of various plasma processes were performed in both reactors. For example, it has been shown that species like NH radicals generated in gas phase can have critical impact on films deposited by ECR plasmas. In the ICP source, plasmas in atomic and molecular gases were shown to have different spatial distributions, likely due to nonlocal electron heating. The low-to-high density transitions in the ICP plasma were also studied. The role of metastables is shown to be significant in Ar plasmas, in contrast to plasmas with additions of molecular gases

  2. High Energy Density Sciences with High Power Lasers at SACLA

    Science.gov (United States)

    Kodama, Ryosuke

    2013-10-01

    One of the interesting topics on high energy density sciences with high power lasers is creation of extremely high pressures in material. The pressures of more than 0.1 TPa are the energy density corresponding to the chemical bonding energy, resulting in expectation of dramatic changes in the chemical reactions. At pressures of more than TPa, most of material would be melted on the shock Hugoniot curve. However, if the temperature is less than 1eV or lower than a melting point at pressures of more than TPa, novel solid states of matter must be created through a pressured phase transition. One of the interesting materials must be carbon. At pressures of more than TPa, the diamond structure changes to BC and cubic at more than 3TPa. To create such novel states of matter, several kinds of isentropic-like compression techniques are being developed with high power lasers. To explore the ``Tera-Pascal Science,'' now we have a new tool which is an x-ray free electron laser as well as high power lasers. The XFEL will clear the details of the HED states and also efficiently create hot dense matter. We have started a new project on high energy density sciences using an XFEL (SACLA) in Japan, which is a HERMES (High Energy density Revolution of Matter in Extreme States) project.

  3. Deterministic Role of Collision Cascade Density in Radiation Defect Dynamics in Si

    Science.gov (United States)

    Wallace, J. B.; Aji, L. B. Bayu; Shao, L.; Kucheyev, S. O.

    2018-05-01

    The formation of stable radiation damage in solids often proceeds via complex dynamic annealing (DA) processes, involving point defect migration and interaction. The dependence of DA on irradiation conditions remains poorly understood even for Si. Here, we use a pulsed ion beam method to study defect interaction dynamics in Si bombarded in the temperature range from ˜-30 ° C to 210 °C with ions in a wide range of masses, from Ne to Xe, creating collision cascades with different densities. We demonstrate that the complexity of the influence of irradiation conditions on defect dynamics can be reduced to a deterministic effect of a single parameter, the average cascade density, calculated by taking into account the fractal nature of collision cascades. For each ion species, the DA rate exhibits two well-defined Arrhenius regions where different DA mechanisms dominate. These two regions intersect at a critical temperature, which depends linearly on the cascade density. The low-temperature DA regime is characterized by an activation energy of ˜0.1 eV , independent of the cascade density. The high-temperature regime, however, exhibits a change in the dominant DA process for cascade densities above ˜0.04 at.%, evidenced by an increase in the activation energy. These results clearly demonstrate a crucial role of the collision cascade density and can be used to predict radiation defect dynamics in Si.

  4. New upper limits on the local metagalactic ionizing radiation density

    Science.gov (United States)

    Vogel, Stuart N.; Weymann, Ray; Rauch, Michael; Hamilton, Tom

    1995-01-01

    We have obtained H-alpha observations with the Maryland-Caltech Fabry-Perot Spectrometer attached to the Cassegrain focus of the 1.5 m telescope at Palomer Observatory in order to set limits on the number of ionizing photons from the local metagalactic radiation field. We have observed the SW component of the Haynes-Giovanelli cloud H I 1225+01, an intergalactic cloud which should be optimum for measuring the metagalactic flux because it is nearly opaque to ionizing photons, it does not appear to be significantly shielded from the metagalactic radiation field, and the limits on embedded or nearby ionizing sources are unusually low. For the area of the cloud with an H I column density greater than 10(exp 19)/sq cm we set a 2 sigma limit of 1.1 x 10(exp -19) ergs/sq cm/s/sq arcsec (20 mR) for the surface brightness of diffuse H-alpha. This implies a 2 sigma upper limit on the incident one-sided ionizing flux of Phi(sub ex) is less than 3 x 10(exp 4)/sq cm/s. For a radiation field of the form J(sub nu) is approximately nu(exp -1.4), this yields a firm 2 sigma upper limit on the local metagalactic photoionization rate of Gamma is less than 2 x 10(exp -13)/s, and an upper limit for the radiation field J(sub nu) at the Lyman limit of J(sub nu0) is less than 8 x 10(exp -23) ergs/sq cm/Hz/sr. We discuss previous efforts to constrain the metagalactic ionizing flux using H-alpha surface brightness observations and also other methods, and conclude that our result places the firmest upper limit on this flux. We also observed the 7 min diameter region centered on 3C 273 in which H-alpha emission at a velocity of approximately 1700 km/s was initially reported by Williams and Schommer. In agreement with T. B. Williams (private communication) we find the initial detection was spurious. We obtain a 2 sigma upper limit of 1.8 x 10(exp -19) ergs/sq cm/s/sq arcsec (32 mR) for the mean surface brightness of diffuse H-alpha, about a factor of 6 below the published value.

  5. High density high-TC ceramic superconductors by hot pressing

    International Nuclear Information System (INIS)

    Mak, S.; Chaklader, A.C.D.

    1989-01-01

    High density and high T C superconductor specimens, YBa 2 Cu 3 O x , have been produced by hot-pressing. The factors studied are the effect of hot pressing on the density, the oxygen stoichiometry, the crystal structure, and the critical temperature. Hot pressing followed by heat treatment increased the density of the specimen to 93%. The hot pressing itself did not significantly affect the oxygen content in the specimen, and although the crystal structure appeared to be orthorhombic, the specimens were not superconducting above liquid nitrogen temperature. The superconductivity was restored after head treatment in oxygen. The highest critical temperature (T C ) of the hot pressed pellets was 82K, which was slightly lower than the T C that could be obtained with the cold pressed/sintered pellets. (6 refs., 5 figs., tab.)

  6. Electromagnetic radiation generated by arcing in low density plasma

    Science.gov (United States)

    Vayner, Boris V.; Ferguson, Dale C.; Snyder, David B.; Doreswamy, C. V.

    1996-01-01

    An unavoidable step in the process of space exploration is to use high-power, very large spacecraft launched into Earth orbit. Obviously, the spacecraft will need powerful energy sources. Previous experience has shown that electrical discharges occur on the surfaces of a high-voltage array, and these discharges (arcs) are undesirable in many respects. Moreover, any high voltage conductor will interact with the surrounding plasma, and that interaction may result in electrical discharges between the conductor and plasma (or between two conductors with different potentials, for example, during docking and extravehicular activity). One very important aspect is the generation of electromagnetic radiation by arcing. To prevent the negative influence of electromagnetic noise on the operation of spacecraft systems, it seems necessary to determine the spectra and absolute levels of the radiation, and to determine limitations on the solar array bias voltage that depend on the parameters of LEO plasma and the technical requirements of the spacecraft equipment. This report describes the results of an experimental study and computer simulation of the electromagnetic radiation generated by arcing on spacecraft surfaces. A large set of high quality data was obtained during the Solar Array Module Plasma Interaction Experiment (SAMPIE, flight STS-62) and ground test. These data include the amplitudes of current, pulse forms, duration of each arc, and spectra of plasma waves. A theoretical explanation of the observed features is presented in this report too. The elaborated model allows us to determine the parameters of the electromagnetic noise for different frequency ranges, distances from the arcing site, and distinct kinds of plasma waves.

  7. High energy radiation from neutron stars

    International Nuclear Information System (INIS)

    Ruderman, M.

    1985-04-01

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

  8. Nanotechnology for Synthetic High Density Lipoproteins

    Science.gov (United States)

    Luthi, Andrea J.; Patel, Pinal C.; Ko, Caroline H.; Mutharasan, R. Kannan; Mirkin, Chad A.; Thaxton, C. Shad

    2014-01-01

    Atherosclerosis is the disease mechanism responsible for coronary heart disease (CHD), the leading cause of death worldwide. One strategy to combat atherosclerosis is to increase the amount of circulating high density lipoproteins (HDL), which transport cholesterol from peripheral tissues to the liver for excretion. The process, known as reverse cholesterol transport, is thought to be one of the main reasons for the significant inverse correlation observed between HDL blood levels and the development of CHD. This article highlights the most common strategies for treating atherosclerosis using HDL. We further detail potential treatment opportunities that utilize nanotechnology to increase the amount of HDL in circulation. The synthesis of biomimetic HDL nanostructures that replicate the chemical and physical properties of natural HDL provides novel materials for investigating the structure-function relationships of HDL and for potential new therapeutics to combat CHD. PMID:21087901

  9. Ground state of high-density matter

    Science.gov (United States)

    Copeland, ED; Kolb, Edward W.; Lee, Kimyeong

    1988-01-01

    It is shown that if an upper bound to the false vacuum energy of the electroweak Higgs potential is satisfied, the true ground state of high-density matter is not nuclear matter, or even strange-quark matter, but rather a non-topological soliton where the electroweak symmetry is exact and the fermions are massless. This possibility is examined in the standard SU(3) sub C tensor product SU(2) sub L tensor product U(1) sub Y model. The bound to the false vacuum energy is satisfied only for a narrow range of the Higgs boson masses in the minimal electroweak model (within about 10 eV of its minimum allowed value of 6.6 GeV) and a somewhat wider range for electroweak models with a non-minimal Higgs sector.

  10. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  11. High density plasmas formation in Inertial Confinement Fusion and Astrophysics

    International Nuclear Information System (INIS)

    Martinez-Val, J. M.; Minguez, E.; Velarde, P.; Perlado, J. M.; Velarde, G.; Bravo, E.; Eliezer, S.; Florido, R.; Garcia Rubiano, J.; Garcia-Senz, D.; Gil de la Fe, J. M.; Leon, P. T.; Martel, P.; Ogando, F.; Piera, M.; Relano, A.; Rodriguez, R.; Garcia, C.; Gonzalez, E.; Lachaise, M.; Oliva, E.

    2005-01-01

    In inertially confined fusion (ICF), high densities are required to obtain high gains. In Fast Ignition, a high density, low temperature plasma can be obtained during the compression. If the final temperature reached is low enough, the electrons of the plasma can be degenerate. In degenerate plasmas. Bremsstrahlung emission is strongly suppressed an ignition temperature becomes lower than in classical plasmas, which offers a new design window for ICF. The main difficulty of degenerate plasmas in the compression energy needed for high densities. Besides that, the low specific heat of degenerate electrons (as compared to classical values) is also a problem because of the rapid heating of the plasma. Fluid dynamic evolution of supernovae remnants is a very interesting problem in order to predict the thermodynamical conditions achieved in their collision regions. Those conditions have a strong influence in the emission of light and therefore the detection of such events. A laboratory scale system has been designed reproducing the fluid dynamic field in high energy experiments. The evolution of the laboratory system has been calculated with ARWEN code, 2D Radiation CFD that works with Adaptive Mesh Refinement. Results are compared with simulations on the original system obtained with a 3D SPH astrophysical code. New phenomena at the collision plane and scaling of the laboratory magnitudes will be described. Atomic physics for high density plasmas has been studied with participation in experiments to obtain laser produced high density plasmas under NLTE conditions, carried out at LULI. A code, ATOM3R, has been developed which solves rate equations for optically thin plasmas as well as for homogeneous optically thick plasmas making use of escape factors. New improvements in ATOM3R are been done to calculate level populations and opacities for non homogeneous thick plasmas in NLTE, with emphasis in He and H lines for high density plasma diagnosis. Analytical expression

  12. Anomalous evolution of Ar metastable density with electron density in high density Ar discharge

    International Nuclear Information System (INIS)

    Park, Min; Chang, Hong-Young; You, Shin-Jae; Kim, Jung-Hyung; Shin, Yong-Hyeon

    2011-01-01

    Recently, an anomalous evolution of argon metastable density with plasma discharge power (electron density) was reported [A. M. Daltrini, S. A. Moshkalev, T. J. Morgan, R. B. Piejak, and W. G. Graham, Appl. Phys. Lett. 92, 061504 (2008)]. Although the importance of the metastable atom and its density has been reported in a lot of literature, however, a basic physics behind the anomalous evolution of metastable density has not been clearly understood yet. In this study, we investigated a simple global model to elucidate the underlying physics of the anomalous evolution of argon metastable density with the electron density. On the basis of the proposed simple model, we reproduced the anomalous evolution of the metastable density and disclosed the detailed physics for the anomalous result. Drastic changes of dominant mechanisms for the population and depopulation processes of Ar metastable atoms with electron density, which take place even in relatively low electron density regime, is the clue to understand the result.

  13. High-density polyethylene dosimetry by transvinylene FTIR analysis

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Silverman, J.; Al-Sheikhly, M.

    1999-01-01

    and electrons. The useful dose range of 0.053 cm thick high-density polyethylene film (rho = 0.961 g cm(-3); melt index = 0.8 dg min(-1)), for irradiations by (60)Co gamma radiation and 2.0 and 0.4 MeV electron beams in deaerated atmosphere (Na gas), is about 50-10(3) kGy for FTIR transvinylene......The formation of transvinylene unsaturation, -CH=CH-, due to free-radical or cationic-initiated dehydrogenation by irradiation, is a basic reaction in polyethylene and is useful for dosimetry at high absorbed doses. The radiation-enhanced infrared absorption having a maximum at nu = 965 cm......(-l) (lambda = 10.36 mu m) is stable in air and can be measured by Fourier-transform infrared (FTIR) spectrophotometry. The quantitative analysis is a useful means of product end-point dosimetry for radiation processing with gamma rays and electrons, where polyethylene is a component of the processed product...

  14. High-field, high-density tokamak power reactor

    International Nuclear Information System (INIS)

    Cohn, D.R.; Cook, D.L.; Hay, R.D.; Kaplan, D.; Kreischer, K.; Lidskii, L.M.; Stephany, W.; Williams, J.E.C.; Jassby, D.L.; Okabayashi, M.

    1977-11-01

    A conceptual design of a compact (R 0 = 6.0 m) high power density (average P/sub f/ = 7.7 MW/m 3 ) tokamak demonstration power reactor has been developed. High magnetic field (B/sub t/ = 7.4 T) and moderate elongation (b/a = 1.6) permit operation at the high density (n(0) approximately 5 x 10 14 cm -3 ) needed for ignition in a relatively small plasma, with a spatially-averaged toroidal beta of only 4%. A unique design for the Nb 3 Sn toroidal-field magnet system reduces the stress in the high-field trunk region, and allows modularization for simpler disassembly. The modest value of toroidal beta permits a simple, modularized plasma-shaping coil system, located inside the TF coil trunk. Heating of the dense central plasma is attained by the use of ripple-assisted injection of 120-keV D 0 beams. The ripple-coil system also affords dynamic control of the plasma temperature during the burn period. A FLIBE-lithium blanket is designed especially for high-power-density operation in a high-field environment, and gives an overall tritium breeding ratio of 1.05 in the slowly pumped lithium

  15. Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U.

    Science.gov (United States)

    Faust, I; Delgado-Aparicio, L; Bell, R E; Tritz, K; Diallo, A; Gerhardt, S P; LeBlanc, B; Kozub, T A; Parker, R R; Stratton, B C

    2014-11-01

    A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed.

  16. Two-dimensional AXUV-based radiated power density diagnostics on NSTX-Ua)

    Science.gov (United States)

    Faust, I.; Delgado-Aparicio, L.; Bell, R. E.; Tritz, K.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B.; Kozub, T. A.; Parker, R. R.; Stratton, B. C.

    2014-11-01

    A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed.

  17. Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U

    Energy Technology Data Exchange (ETDEWEB)

    Faust, I.; Parker, R. R. [MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B.; Kozub, T. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Tritz, K. [The Johns Hopkins University, Baltimore, Maryland 21209 (United States); Stratton, B. C. [MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)

    2014-11-15

    A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed.

  18. Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U

    International Nuclear Information System (INIS)

    Faust, I.; Parker, R. R.; Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B.; Kozub, T. A.; Tritz, K.; Stratton, B. C.

    2014-01-01

    A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed

  19. High-LET radiation carcinogenesis

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  20. A unifying probabilistic Bayesian approach to derive electron density from MRI for radiation therapy treatment planning

    International Nuclear Information System (INIS)

    Gudur, Madhu Sudhan Reddy; Hara, Wendy; Le, Quynh-Thu; Wang, Lei; Xing, Lei; Li, Ruijiang

    2014-01-01

    MRI significantly improves the accuracy and reliability of target delineation in radiation therapy for certain tumors due to its superior soft tissue contrast compared to CT. A treatment planning process with MRI as the sole imaging modality will eliminate systematic CT/MRI co-registration errors, reduce cost and radiation exposure, and simplify clinical workflow. However, MRI lacks the key electron density information necessary for accurate dose calculation and generating reference images for patient setup. The purpose of this work is to develop a unifying method to derive electron density from standard T1-weighted MRI. We propose to combine both intensity and geometry information into a unifying probabilistic Bayesian framework for electron density mapping. For each voxel, we compute two conditional probability density functions (PDFs) of electron density given its: (1) T1-weighted MRI intensity, and (2) geometry in a reference anatomy, obtained by deformable image registration between the MRI of the atlas and test patient. The two conditional PDFs containing intensity and geometry information are combined into a unifying posterior PDF, whose mean value corresponds to the optimal electron density value under the mean-square error criterion. We evaluated the algorithm’s accuracy of electron density mapping and its ability to detect bone in the head for eight patients, using an additional patient as the atlas or template. Mean absolute HU error between the estimated and true CT, as well as receiver operating characteristics for bone detection (HU > 200) were calculated. The performance was compared with a global intensity approach based on T1 and no density correction (set whole head to water). The proposed technique significantly reduced the errors in electron density estimation, with a mean absolute HU error of 126, compared with 139 for deformable registration (p = 2  ×  10 −4 ), 283 for the intensity approach (p = 2  ×  10 −6 ) and 282

  1. Effect of Varieties and Plant Population Densities on Dry Matter Production, Radiation Interception and Radiation Energy Conversion in Peanut

    Directory of Open Access Journals (Sweden)

    agus suprapto

    2012-05-01

    Full Text Available The solar radiation is one of the major criteria to obtaining advantages on peanuts (Arachishypogaea L.. Although various combinations of crops have been reported, but variety association and plant population densities (PPD during the periodically stage of growth on peanuts have yet to be analyzed. Dry matter production (DM, radiation energy interception, and radiation energy conversions were monitored over the growth period of two varieties of peanut. An experiment was conducted in Jambegede Research Farm, Indonesian Legume and Tuber Crops Research Institute, Malang, East Java, Indonesia, from July until October 2011. The experiment was arranged in a Split Plot Design with three replications. Peanut varieties, as the main plot consisted of two treatments: Kelinci andKancil variety. In addition, five PPD variations as sub plot consisted of 8.1, 11.1, 16.0, 25.0 and 44.4 plant m-2 were arranged in a square spacing. The results showed that DM production from high PPD increased gradually to lower PPD in all varieties. Interception efficiency (IE increased in all varieties from early sowing. A plant population density of 25.0 m-2 and 44.4 plants m-2 intercepted more radiation over 11.1 or 16.0 plants m-2. Conversion efficiency of radiation energy (CE to total dry matter production on Kelinci variety (1.52% indicated a slight higher percentage than on Kancil variety (1.41%. Moreover, the CE and IE values indicated a decrease as the PPD increased on maximum DM.

  2. Highly efficient red electrophosphorescent devices at high current densities

    International Nuclear Information System (INIS)

    Wu Youzhi; Zhu Wenqing; Zheng Xinyou; Sun, Runguang; Jiang Xueyin; Zhang Zhilin; Xu Shaohong

    2007-01-01

    Efficiency decrease at high current densities in red electrophosphorescent devices is drastically restrained compared with that from conventional electrophosphorescent devices by using bis(2-methyl-8-quinolinato)4-phenylphenolate aluminum (BAlq) as a hole and exciton blocker. Ir complex, bis(2-(2'-benzo[4,5-α]thienyl) pyridinato-N,C 3' ) iridium (acetyl-acetonate) is used as an emitter, maximum external quantum efficiency (QE) of 7.0% and luminance of 10000cd/m 2 are obtained. The QE is still as high as 4.1% at higher current density J=100mA/cm 2 . CIE-1931 co-ordinates are 0.672, 0.321. A carrier trapping mechanism is revealed to dominate in the process of electroluminescence

  3. High-density oxidized porous silicon

    International Nuclear Information System (INIS)

    Gharbi, Ahmed; Souifi, Abdelkader; Remaki, Boudjemaa; Halimaoui, Aomar; Bensahel, Daniel

    2012-01-01

    We have studied oxidized porous silicon (OPS) properties using Fourier transform infraRed (FTIR) spectroscopy and capacitance–voltage C–V measurements. We report the first experimental determination of the optimum porosity allowing the elaboration of high-density OPS insulators. This is an important contribution to the research of thick integrated electrical insulators on porous silicon based on an optimized process ensuring dielectric quality (complete oxidation) and mechanical and chemical reliability (no residual pores or silicon crystallites). Through the measurement of the refractive indexes of the porous silicon (PS) layer before and after oxidation, one can determine the structural composition of the OPS material in silicon, air and silica. We have experimentally demonstrated that a porosity approaching 56% of the as-prepared PS layer is required to ensure a complete oxidation of PS without residual silicon crystallites and with minimum porosity. The effective dielectric constant values of OPS materials determined from capacitance–voltage C–V measurements are discussed and compared to FTIR results predictions. (paper)

  4. Temperature and carrier-density dependence of Auger and radiative recombination in nitride optoelectronic devices

    International Nuclear Information System (INIS)

    Kioupakis, Emmanouil; Yan, Qimin; Steiauf, Daniel; Van de Walle, Chris G

    2013-01-01

    Nitride light-emitting diodes are a promising solution for efficient solid-state lighting, but their performance at high power is affected by the efficiency-droop problem. Previous experimental and theoretical work has identified Auger recombination, a three-particle nonradiative carrier recombination mechanism, as the likely cause of the droop. In this work, we use first-principles calculations to elucidate the dependence of the radiative and Auger recombination rates on temperature, carrier density and quantum-well confinement. Our calculated data for the temperature dependence of the recombination coefficients are in good agreement with experiment and provide further validation on the role of Auger recombination in the efficiency reduction. Polarization fields and phase-space filling negatively impact device efficiency because they increase the operating carrier density at a given current density and increase the fraction of carriers lost to Auger recombination. (paper)

  5. Radiation effects of high and low doses

    International Nuclear Information System (INIS)

    El-Naggar, A.M.

    1998-01-01

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

  6. Frontiers in pulse-power-based high energy density plasma physics and its applications

    International Nuclear Information System (INIS)

    Horioka, Kazuhiko

    2008-03-01

    The papers in this volume of report were presented at the Symposium on Frontiers in Pulse-power-based High Energy Density Physics' held by National Institute for Fusion Science. The topics include the present status of high energy density plasma researches, extreme ultraviolet sources, intense radiation sources, high power ion beams, and R and D of related pulse power technologies. The 13 of the presented papers are indexed individually. (J.P.N.)

  7. High Energy Density Physics and Exotic Acceleration Schemes

    International Nuclear Information System (INIS)

    Cowan, T.; Colby, E.

    2005-01-01

    be a very important field for diverse applications such as muon cooling, fusion energy research, and ultra-bright particle and radiation generation with high intensity lasers. We had several talks on these and other subjects, and many joint sessions with the Computational group, the EM Structures group, and the Beam Generation group. We summarize our groups' work in the following categories: vacuum acceleration schemes; ion acceleration; particle transport in solids; and applications to high energy density phenomena

  8. Density measurements of small amounts of high-density solids by a floatation method

    International Nuclear Information System (INIS)

    Akabori, Mitsuo; Shiba, Koreyuki

    1984-09-01

    A floatation method for determining the density of small amounts of high-density solids is described. The use of a float combined with an appropriate floatation liquid allows us to measure the density of high-density substances in small amounts. Using the sample of 0.1 g in weight, the floatation liquid of 3.0 g cm -3 in density and the float of 1.5 g cm -3 in apparent density, the sample densities of 5, 10 and 20 g cm -3 are determined to an accuracy better than +-0.002, +-0.01 and +-0.05 g cm -3 , respectively that correspond to about +-1 x 10 -5 cm 3 in volume. By means of appropriate degassing treatments, the densities of (Th,U)O 2 pellets of --0.1 g in weight and --9.55 g cm -3 in density were determined with an accuracy better than +-0.05 %. (author)

  9. Use of ordinary kriging and Gaussian conditional simulation to interpolate airborne fire radiative energy density estimates

    Science.gov (United States)

    C. Klauberg; A. T. Hudak; B. C. Bright; L. Boschetti; M. B. Dickinson; R. L. Kremens; C. A. Silva

    2018-01-01

    Fire radiative energy density (FRED, J m-2) integrated from fire radiative power density (FRPD, W m-2) observations of landscape-level fires can present an undersampling problem when collected from fixed-wing aircraft. In the present study, the aircraft made multiple passes over the fire at ~3 min intervals, thus failing to observe most of the FRPD emitted as the flame...

  10. High energy particle accelerators as radiation Sources

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  11. Radiation metabolomics : a window to high throughput radiation biodosimetry

    International Nuclear Information System (INIS)

    Rana, Poonam

    2016-01-01

    In the event of an intentional or accidental release of ionizing radiation in a densely populated area, timely assessment and triage of the general population for radiation exposure is critical. In particular, a significant number of victims may sustain radiation injury, which increases mortality and worsens the overall prognosis of victims from radiation trauma. Availability of a high-throughput noninvasive in vivo biodosimetry tool for assessing the radiation exposure is of particular importance for timely diagnosis of radiation injury. In this study, we describe the potential NMR techniques in evaluating the radiation injury. NMR is the most versatile technique that has been extensively used in the diverse fields of science since its discovery. NMR and biomedical sciences have been going hand in hand since its application in clinical imaging as MRI and metabolic profiling of biofluids was identified. We have established an NMR based metabonomic and in vivo spectroscopy approach to analyse and identify metabolic profile to measure metabolic fingerprint for radiation exposure. NMR spectroscopy experiments were conducted on urine and serum samples collected from mice irradiated with different doses of radiation. Additionally, in vivo NMR spectroscopy was also performed in different region of brains post irradiation in animal model. A number of metabolites associated with energy metabolism, gut flora metabolites, osmolytes, amino acids and membrane metabolism were identified in serum and urine metabolome. Our results illustrated a metabolic fingerprint for radiation exposure that elucidates perturbed physiological functions. Quantitative as well as multivariate analysis/assessment of these metabolites demonstrated dose and time dependent toxicological effect. In vivo spectroscopy from brain showed radiation induced changes in hippocampus region indicating whole body radiation had striking effect on brain metabolism as well. The results of the present work lay a

  12. Radiative corrections for the direct detection of neutralino dark matter and its relic density

    Energy Technology Data Exchange (ETDEWEB)

    Steppeler, Patrick Norbert

    2016-07-01

    In this thesis we calculate supersymmetric one-loop corrections of the strong interaction to elastic neutralino-nucleon scattering. The calculation is described in detail and performed in full generality within the Minimal Supersymmetric Standard Model (MSSM). In order to benefit from the well-established tensor reduction method, we have to stabilise the latter for vanishing Gram determinants. Afterwards the radiative corrections are matched onto an effective field theory based on the scalar operator anti χχ anti qq and the axial-vector operator anti χγ{sub 5}γ{sub μ}χ anti qγ{sub 5}γ{sup μ}q. This matching procedure is performed at the high scale μ{sub high}∝1000 GeV, whereas the associated nuclear matrix elements are defined at the low scale μ{sub low}∝5 GeV. To link both scales, the running of the effective operators and their corresponding Wilson coefficients is taken into account via renormalisation group equations. The lightest neutralino can be considered as a canonical example for a weakly interacting, massive particle which could constitute dark matter. To verify the existence of such particles, so-called direct detection experiments are conducted currently. These are based on the interaction between dark matter and nucleons. The leading contributions to the spin-independent and spin-dependent neutralino-nucleon cross sections are governed by the effective operators mentioned above, respectively. The calculation of the associated radiative corrections corresponds to a reduction of the theoretical uncertainty and permits to identify neutralino properties more reliably in case of positive findings and to set more robust exclusion bounds in case of negative findings. Furthermore, we calculate radiative corrections to annihilation and coannihilation processes of gauginos into quarks, where we focus again on supersymmetric one-loop corrections of the strong interaction. These processes contribute dominantly to the (co)annihilation cross section

  13. Radiographic imaging system for high energy radiation

    International Nuclear Information System (INIS)

    1975-01-01

    A radiographic imaging system for high energy radiation is described utilizing a detector of such radiation and a mask having regions relatively transparent to such radiation and interspersed among regions relatively opaque to such radiation. A relative motion is imparted between the mask and the detector, the detector providing a time varying signal in response to the incident radiation and in response to the relative motion. The time varying signal provides, with the aid of a decoder, an image of a source of such radiation

  14. Radiographic imaging system for high energy radiation

    International Nuclear Information System (INIS)

    Barrett, H.H.

    1976-01-01

    A radiographic imaging system for high energy radiation utilizing a detector of such radiation and a mask having regions relatively transparent to such radiation interspersed among regions relatively opaque to such radiation is described. A relative motion is imparted between the mask and the detector, the detector providing a time varying signal in response to the incident radiation and in response to the relative motion. The time varying signal provides, with the aid of a decoder, an image of a source of such radiation

  15. High technology for radiation application

    International Nuclear Information System (INIS)

    Iida, Toshiyuki

    2005-03-01

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

  16. Neutron shielding properties of a borated high-density glass

    Directory of Open Access Journals (Sweden)

    Saeed Aly Abdallah

    2017-01-01

    Full Text Available The neutron shielding properties of a borated high density glass system was characterized experimentally. The total removal macroscopic cross-section of fast neutrons, slow neutrons as well as the linear attenuation coefficient of total gamma rays, primary in addition to secondary, were measured experimentally under good geometric condition to characterize the attenuation properties of (75-x B2O3-1Li2O-5MgO-5ZnO-14Na2O-xBaO glassy system. Slabs of different thicknesses from the investigated glass system were exposed to a collimated beam of neutrons emitted from 252Cf and 241Am-Be neutron sources in order to measure the attenuation properties of fast and slow neutrons as well as total gamma rays. Results confirmed that barium borate glass was suitable for practical use in the field of radiation shielding.

  17. Practical high-density shielding materials for medical linear accelerator rooms

    International Nuclear Information System (INIS)

    Barish, R.J.

    1990-01-01

    High-energy linear accelerators are replacing lower energy units in radiation therapy centers. Radiation protection requirements necessitate expensive reconstruction of existing treatment rooms to accommodate these new machines. We describe two shielding materials: one made by embedding small pieces of scrap steel in cement, and the other made with cast iron in cement. Both materials produce high-density barriers at low cost using standard construction methods

  18. Ignition and burn in contaminated DT fuel at high densities

    International Nuclear Information System (INIS)

    Pasley, J.

    2010-01-01

    Complete text of publication follows. Radiation hydrodynamics simulations have been performed to quantify the effect of contamination upon the ignition threshold in DT at high densities. A detailed thermonuclear burn model, with multi-group multispecies ions, is incorporated alongside a multigroup diffusion approximation for thermal radiation transport. The code used is the research version of the HYADES 1D code. Acceptable levels of contamination are identified for a range of contaminant ion species. A range of different contaminant spatial distribution within the fuel are explored: i) in which the contamination is uniformly distributed throughout the fuel; ii) in which the impurity ions are confined to the hotspot, or iii) where contamination is restricted to a particular region of the hotspot (either centrally, near the surface, or at an intermediate location). Initially the fuel has a constant density with the hotspot located centrally. The overall radius of the fuel is chosen to be sufficiently large that it has no significant effect upon the success or failure of ignition. The evolution of the system is then simulated until ignition either establishes widespread thermonuclear burning, or a failure to ignite is observed. The critical ρr for ignition is found by iteration on the hotspot radius. We show that varying the spatial distribution of the contaminant within the ignition spot has little effect, so long as the total mass of contaminant is held the same. As expected, high-Z contamination is far more detrimental than that by low-Z ions. Discussion of the findings in the context of re-entrant cone-guided fast ignition is presented, in addition to a theoretical interpretation of the results.

  19. Workshop on High Power ICH Antenna Designs for High Density Tokamaks

    Science.gov (United States)

    Aamodt, R. E.

    1990-02-01

    A workshop in high power ICH antenna designs for high density tokamaks was held to: (1) review the data base relevant to the high power heating of high density tokamaks; (2) identify the important issues which need to be addressed in order to ensure the success of the ICRF programs on CIT and Alcator C-MOD; and (3) recommend approaches for resolving the issues in a timely realistic manner. Some specific performance goals for the antenna system define a successful design effort. Simply stated these goals are: couple the specified power per antenna into the desired ion species; produce no more than an acceptable level of RF auxiliary power induced impurities; and have a mechanical structure which safely survives the thermal, mechanical and radiation stresses in the relevant environment. These goals are intimately coupled and difficult tradeoffs between scientific and engineering constraints have to be made.

  20. Workshop on high power ICH antenna designs for high density tokamaks

    International Nuclear Information System (INIS)

    Aamodt, R.E.

    1990-01-01

    A workshop in high power ICH antenna designs for high density tokamaks was held in Boulder, Colorado on January 31 through February 2, 1990. The purposes of the workshop were to: (1) review the data base relevant to the high power heating of high density tokamaks; (2) identify the important issues which need to be addressed in order to ensure the success of the ICRF programs on CIT and Alcator C-MOD; and (3) recommend approaches for resolving the issues in a timely realistic manner. Some specific performance goals for the antenna system define a successful design effort. Simply stated these goals are: couple the specified power per antenna into the desired ion species; produce no more than an acceptable level of rf auxiliary power induced impurities; and have a mechanical structure which safely survives the thermal, mechanical and radiation stresses in the relevant environment. These goals are intimately coupled and difficult tradeoffs between scientific and engineering constraints have to be made

  1. Communication: Simple liquids' high-density viscosity

    Science.gov (United States)

    Costigliola, Lorenzo; Pedersen, Ulf R.; Heyes, David M.; Schrøder, Thomas B.; Dyre, Jeppe C.

    2018-02-01

    This paper argues that the viscosity of simple fluids at densities above that of the triple point is a specific function of temperature relative to the freezing temperature at the density in question. The proposed viscosity expression, which is arrived at in part by reference to the isomorph theory of systems with hidden scale invariance, describes computer simulations of the Lennard-Jones system as well as argon and methane experimental data and simulation results for an effective-pair-potential model of liquid sodium.

  2. Communication: Simple liquids' high-density viscosity.

    Science.gov (United States)

    Costigliola, Lorenzo; Pedersen, Ulf R; Heyes, David M; Schrøder, Thomas B; Dyre, Jeppe C

    2018-02-28

    This paper argues that the viscosity of simple fluids at densities above that of the triple point is a specific function of temperature relative to the freezing temperature at the density in question. The proposed viscosity expression, which is arrived at in part by reference to the isomorph theory of systems with hidden scale invariance, describes computer simulations of the Lennard-Jones system as well as argon and methane experimental data and simulation results for an effective-pair-potential model of liquid sodium.

  3. Growth limitation of Lemna minor due to high plant density

    NARCIS (Netherlands)

    Driever, S.M.; Nes, van E.H.; Roijackers, R.M.M.

    2005-01-01

    The effect of high population densities on the growth rate of Lemna minor (L.) was studied under laboratory conditions at 23°C in a medium with sufficient nutrients. At high population densities, we found a non-linear decreasing growth rate with increasing L. minor density. Above a L. minor biomass

  4. Imaginary time density-density correlations for two-dimensional electron gases at high density

    Energy Technology Data Exchange (ETDEWEB)

    Motta, M.; Galli, D. E. [Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Moroni, S. [IOM-CNR DEMOCRITOS National Simulation Center and SISSA, Via Bonomea 265, 34136 Trieste (Italy); Vitali, E. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795 (United States)

    2015-10-28

    We evaluate imaginary time density-density correlation functions for two-dimensional homogeneous electron gases of up to 42 particles in the continuum using the phaseless auxiliary field quantum Monte Carlo method. We use periodic boundary conditions and up to 300 plane waves as basis set elements. We show that such methodology, once equipped with suitable numerical stabilization techniques necessary to deal with exponentials, products, and inversions of large matrices, gives access to the calculation of imaginary time correlation functions for medium-sized systems. We discuss the numerical stabilization techniques and the computational complexity of the methodology and we present the limitations related to the size of the systems on a quantitative basis. We perform the inverse Laplace transform of the obtained density-density correlation functions, assessing the ability of the phaseless auxiliary field quantum Monte Carlo method to evaluate dynamical properties of medium-sized homogeneous fermion systems.

  5. Electrode/Dielectric Strip For High-Energy-Density Capacitor

    Science.gov (United States)

    Yen, Shiao-Ping S.

    1994-01-01

    Improved unitary electrode/dielectric strip serves as winding in high-energy-density capacitor in pulsed power supply. Offers combination of qualities essential for high energy density: high permittivity of dielectric layers, thinness, and high resistance to breakdown of dielectric at high electric fields. Capacitors with strip material not impregnated with liquid.

  6. Modification of low density polyethylene, isostatic polypropylene and their blends by gamma radiation

    International Nuclear Information System (INIS)

    Santos Rosa, D. dos

    1991-01-01

    The effects of the gamma radiation (of a 60 Co source), over low density polyethylene, isostatic polypropylene and their blends of low density polyethylene / polypropylene were studied. The structures modifications were attended by infrared spectrometry (IV), differential scanning calorimeter (DSC), strain-strain measurement, density measurement and scanning electron microscope (SEM). (author)

  7. Physics and applications of high energy density plasmas. Extreme state driven by pulsed electromagnetic energy

    International Nuclear Information System (INIS)

    Horioka, Kazuhiko

    2002-06-01

    The papers presented at the symposium on ''Physics and application of high energy density plasmas, held December 20-21, 2001 at NIFS'' are collected in this proceedings. The topics covered in the meeting include dense z-pinches, plasma focus, intense charged particle beams, intense radiation sources, discharge pumped X-ray lasers, their diagnostics, and applications of them. The papers reflect the present status and trends in the research field of high energy density plasmas. (author)

  8. Variable kernel density estimation in high-dimensional feature spaces

    CSIR Research Space (South Africa)

    Van der Walt, Christiaan M

    2017-02-01

    Full Text Available Estimating the joint probability density function of a dataset is a central task in many machine learning applications. In this work we address the fundamental problem of kernel bandwidth estimation for variable kernel density estimation in high...

  9. The Influence of Decreased Levels of High Density Lipoprotein ...

    African Journals Online (AJOL)

    very low density lipoprotein cholesterol, and triglyceride were assayed. ... Abiodun and Gwarzo: Association of high density lipoprotein cholesterol with haemolysis in sickle cell disease ... analyses were carried out to determine the correlation.

  10. High-Latitude Neutral Mass Density Maxima

    Science.gov (United States)

    Huang, C. Y.; Huang, Y.; Su, Y.-J.; Huang, T.; Sutton, E. K.

    2017-10-01

    Recent studies have reported that thermospheric effects due to solar wind driving can be observed poleward of auroral latitudes. In these papers, the measured neutral mass density perturbations appear as narrow, localized maxima in the cusp and polar cap. They conclude that Joule heating below the spacecraft is the cause of the mass density increases, which are sometimes associated with local field-aligned current structures, but not always. In this paper we investigate neutral mass densities measured by accelerometers on the CHAllenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) spacecraft from launch until years 2010 (CHAMP) and 2012 (GRACE), approximately 10 years of observations from each satellite. We extract local maxima in neutral mass densities over the background using a smoothing window with size of one quarter of the orbit. The maxima have been analyzed for each year and also for the duration of each set of satellite observations. We show where they occur, under what solar wind conditions, and their relation to magnetic activity. The region with the highest frequency of occurrence coincides approximately with the cusp and mantle, with little direct evidence of an auroral zone source. Our conclusions agree with the "hot polar cap" observations that have been reported and studied in the past.

  11. Improved GAMMA 10 tandem mirror confinement in high density plasma

    International Nuclear Information System (INIS)

    Yatsu, K.; Cho, T.; Higaki, H.; Hirata, M.; Hojo, H.; Ichimura, M.; Ishii, K.; Ishimoto, Y.; Itakura, A.; Katanuma, I.; Kohagura, J.; Minami, R.; Nakashima, Y.; Numakura, T.; Saito, T.; Saosaki, S.; Takemura, Y.; Tatematsu, Y.; Yoshida, M.; Yoshikawa, M.

    2003-01-01

    GAMMA 10 experiments have advanced in high density experiments after the last IAEA fusion energy conference in 2000 where we reported the production of the high density plasma through use of ion cyclotron range of frequency heating at a high harmonic frequency and neutral beam injection in the anchor cells. However, the diamagnetic signal of the plasma decreased when electron cyclotron resonance heating was applied for the potential formation. Recently a high density plasma has been obtained without degradation of the diamagnetic signal and with much improved reproducibility than before. The high density plasma was attained through adjustment of the spacing of the conducting plates installed in the anchor transition regions. The potential confinement of the plasma has been extensively studied. Dependences of the ion confinement time, ion-energy confinement time and plasma confining potential on plasma density were obtained for the first time in the high density region up to a density of 4x10 18 m -3 . (author)

  12. Lightweight, High-Temperature Radiator for Space Propulsion

    Science.gov (United States)

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

    2012-01-01

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

  13. High density turbulent plasma processes from a shock tube

    International Nuclear Information System (INIS)

    Oyedeji, O.; Johnson, J.A. III

    1991-01-01

    We have finished the first stages of our experimental and theoretical investigations on models for energy and momentum transport and for photon-particle collision processes in a turbulent quasi-stationary high density plasma. The system is explored by beginning to determine the turbulence phenomenology associated with an ionizing shock wave. The theoretical underpinnings are explored for phonon particle collisions by determining the collisional redistribution function, using Lioville Space Green's Function, which will characterize the inelastic scattering of the radiation from one frequency to another. We have observed that a weak magnetic field tends to increase the apparent random-like behaviors in a collisional turbulent plasma. On the theoretical side, we have been able to achieve a form for the collisional redistribution function. It remains to apply these concepts to a stationary turbulent plasma in the reflected ionizing shock wave and to exercise the implications of evaluations of the collisional redistribution function for such a system when it is probed by a strong radiation source. These results are discussed in detail in the publications, which have resulted from the this effort, cited at the end of the report

  14. Highly Compressed Ion Beams for High Energy Density Science

    CERN Document Server

    Friedman, Alex; Briggs, Richard J; Callahan, Debra; Caporaso, George; Celata, C M; Davidson, Ronald C; Faltens, Andy; Grant-Logan, B; Grisham, Larry; Grote, D P; Henestroza, Enrique; Kaganovich, Igor D; Lee, Edward; Lee, Richard; Leitner, Matthaeus; Nelson, Scott D; Olson, Craig; Penn, Gregory; Reginato, Lou; Renk, Tim; Rose, David; Sessler, Andrew M; Staples, John W; Tabak, Max; Thoma, Carsten H; Waldron, William; Welch, Dale; Wurtele, Jonathan; Yu, Simon

    2005-01-01

    The Heavy Ion Fusion Virtual National Laboratory (HIF-VNL) is developing the intense ion beams needed to drive matter to the High Energy Density (HED) regimes required for Inertial Fusion Energy (IFE) and other applications. An interim goal is a facility for Warm Dense Matter (WDM) studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach we are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target "foils," which may in fact be foams or "steel wool" with mean densities 1% to 100% of solid. This approach complements that being pursued at GSI, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrical target. We present the requirements for warm dense matter experiments, and describe suitable accelerator concepts, including novel broadband traveling wave pulse-line, drift-tube linac, RF, and single-gap approa...

  15. Similarity and self-similarity in high energy density physics: application to laboratory astrophysics

    International Nuclear Information System (INIS)

    Falize, E.

    2008-10-01

    The spectacular recent development of powerful facilities allows the astrophysical community to explore, in laboratory, astrophysical phenomena where radiation and matter are strongly coupled. The titles of the nine chapters of the thesis are: from high energy density physics to laboratory astrophysics; Lie groups, invariance and self-similarity; scaling laws and similarity properties in High-Energy-Density physics; the Burgan-Feix-Munier transformation; dynamics of polytropic gases; stationary radiating shocks and the POLAR project; structure, dynamics and stability of optically thin fluids; from young star jets to laboratory jets; modelling and experiences for laboratory jets

  16. Development of high temperature superconductors having high critical current density

    International Nuclear Information System (INIS)

    Hong, Gye Wong; Kim, C. J.; Lee, H.G.; Kwon, S. C.; Lee, H. J.; Kim, K. B.; Park, J. Y.; Jung, C. H.

    2000-08-01

    Fabrication of high T c superconductors and its applications for electric power device were carried out for developing superconductor application technologies. High quality YBCO superconductors was fabricated by melt texture growth, top-seeded melt growth process and multi-seeded melt growth process and the properties was compared. The critical current density of the melt processed YBCO superconductors was about few 10,000 A/cm 2 and the levitation force was 50 N. The processing time needed for the growth of the 123 single grain was greatly reduced by applying multi-seeding without no significant degradation of the levitation force. The multi-seeded melt growth process was confirmed as a time-saving and cost-effective method for the fabrication of bulk superconductors with controlled crystallographic orientation

  17. Development of high temperature superconductors having high critical current density

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Gye Wong; Kim, C. J.; Lee, H.G.; Kwon, S. C.; Lee, H. J.; Kim, K. B.; Park, J. Y.; Jung, C. H

    2000-08-01

    Fabrication of high T{sub c} superconductors and its applications for electric power device were carried out for developing superconductor application technologies. High quality YBCO superconductors was fabricated by melt texture growth, top-seeded melt growth process and multi-seeded melt growth process and the properties was compared. The critical current density of the melt processed YBCO superconductors was about few 10,000 A/cm{sup 2} and the levitation force was 50 N. The processing time needed for the growth of the 123 single grain was greatly reduced by applying multi-seeding without no significant degradation of the levitation force. The multi-seeded melt growth process was confirmed as a time-saving and cost-effective method for the fabrication of bulk superconductors with controlled crystallographic orientation.

  18. High-frequency emissions during the propagation of an electron beam in a high-density plasma

    International Nuclear Information System (INIS)

    Lalita and Tripathi, V.K.

    1988-01-01

    A relativistic annular electron beam passing through a high-density plasma excites Langmuir waves via Cerenkov interaction. The Langmuir waves are backscattered off ions via nonlinear ion Landau damping. At moderately high amplitudes these waves are parametrically up-converted by the beam into high-frequency electromagnetic radiation, as observed in some recent experiments. A nonlocal theory of this process is developed in a cylindrical geometry. It is seen that the growth rate of the Langmuir wave scales as one-third power of beam density. The growth rate of parametric instability scales as one-fourth power of beam density and the square root of beam thickness

  19. Sputtered thin films for high density tape recording

    NARCIS (Netherlands)

    Nguyen, L.T.

    This thesis describes the investigation of sputtered thin film media for high density tape recording. As discussed in Chapter 1, to meet the tremendous demand of data storage, the density of recording tape has to be increased continuously. For further increasing the bit density the key factors are:

  20. Pulsed power drivers for ICF and high energy density physics

    International Nuclear Information System (INIS)

    Ramirez, J.J.; Matzen, M.K.; McDaniel, D.H.

    1995-01-01

    Nanosecond Pulsed Power Science and Technology has its origins in the 1960s and over the past decade has matured into a flexible and robust discipline capable of addressing key physics issues of importance to ICF and high Energy Density Physics. The major leverage provided by pulsed power is its ability to generate and deliver high energy and high power at low cost and high efficiency. A low-cost, high-efficiency driver is important because of the very large capital investment required for multi-megajoule ignition-class systems. High efficiency is of additional importance for a commercially viable inertial fusion energy option. Nanosecond pulsed power has been aggressively and successfully developed at Sandia over the past twenty years. This effort has led to the development of unique multi-purpose facilities supported by highly capable diagnostic, calculational and analytic capabilities. The Sandia Particle-beam Fusion Program has evolved as part of an integrated national ICF Program. It applies the low-cost, high-efficiency leverage provided by nanosecond pulsed power systems to the longer-term goals of the national program, i.e., the Laboratory Microfusion Facility and Inertial Fusion Energy. A separate effort has led to the application of nanosecond pulsed power to the generation of intense, high-energy laboratory x-ray sources for application to x-ray laser and radiation effects science research. Saturn is the most powerful of these sources to date. It generates ∼500 kilojoules of x-rays from a magnetically driven implosion (Z-pinch). This paper describes results of x-ray physics experiments performed on Saturn, plans for a new Z-pinch drive capability for PBFA-II, and a design concept for the proposed ∼15 MJ Jupiter facility. The opportunities for ICF-relevant research using these facilities will also be discussed

  1. High Efficiency, High Density Terrestrial Panel. [for solar cell modules

    Science.gov (United States)

    Wohlgemuth, J.; Wihl, M.; Rosenfield, T.

    1979-01-01

    Terrestrial panels were fabricated using rectangular cells. Packing densities in excess of 90% with panel conversion efficiencies greater than 13% were obtained. Higher density panels can be produced on a cost competitive basis with the standard salami panels.

  2. High Efficency Lightweight Radiators, Phase I

    Data.gov (United States)

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

  3. High Energy Density Dielectrics for Pulsed Power Applications

    National Research Council Canada - National Science Library

    Wu, Richard L; Bray, Kevin R

    2008-01-01

    This report was developed under a SBIR contract. Aluminum oxynitride (AlON) capacitors exhibit several promising characteristics for high energy density capacitor applications in extreme environments...

  4. Development of large high current density superconducting solenoid magnets for use in high energy physics experiments

    International Nuclear Information System (INIS)

    Green, M.A.

    1977-05-01

    The development of a unique type of large superconducting solenoid magnet, characterized by very high current density windings and a two-phase helium tubular cooling system is described. The development of the magnet's conceptual design and the construction of two test solenoids are described. The successful test of the superconducting coil and its tubular cooling refrigeration system is presented. The safety, environmental and economic impacts of the test program on future developments in high energy physics are shown. Large solid angle particle detectors for colliding beam physics will analyze both charged and neutral particles. In many cases, these detectors will require neutral particles, such as gamma rays, to pass through the magnet coil with minimum interaction. The magnet coils must be as thin as possible. The use of superconducting windings allows one to minimize radiation thickness, while at the same time maximizing charged particle momentum resolution and saving substantial quantities of electrical energy. The results of the experimental measurements show that large high current density solenoid magnets can be made to operate at high stored energies. The superconducting magnet development described has a positive safety and environmental impact. The use of large high current density thin superconducting solenoids has been proposed in two high energy physics experiments to be conducted at the Stanford Linear Accelerator Center and Cornell University as a result of the successful experiments described

  5. High density, high magnetic field concepts for compact fusion reactors

    International Nuclear Information System (INIS)

    Perkins, L.J.

    1996-01-01

    One rather discouraging feature of our conventional approaches to fusion energy is that they do not appear to lend themselves to a small reactor for developmental purposes. This is in contrast with the normal evolution of a new technology which typically proceeds to a full scale commercial plant via a set of graduated steps. Accordingly' several concepts concerned with dense plasma fusion systems are being studied theoretically and experimentally. A common aspect is that they employ: (a) high to very high plasma densities (∼10 16 cm -3 to ∼10 26 cm -3 ) and (b) magnetic fields. If they could be shown to be viable at high fusion Q, they could conceivably lead to compact and inexpensive commercial reactors. At least, their compactness suggests that both proof of principle experiments and development costs will be relatively inexpensive compared with the present conventional approaches. In this paper, the following concepts are considered: (1) The staged Z-pinch, (2) Liner implosion of closed-field-line configurations, (3) Magnetic ''fast'' ignition of inertial fusion targets, (4) The continuous flow Z-pinch

  6. Radiation damage in a high Ni weld

    International Nuclear Information System (INIS)

    Brumovsky, M.; Kytka, M.; Kopriva, R.

    2015-01-01

    WWER-1000 RPV weld metals are characterized by a high content of nickel, mostly about 1.7 mass % with content of manganese around 0.8 mass % with a very low copper content - about 0.05 mass %. In such material some late blooming phase effect should be observed during irradiation. Such typical weld material was irradiated in the experimental reactor LVR-15 in N RI Rez at the irradiation temperature 290 C degrees and at five neutron fluences from 1.5 to 9.5 *10 23 m -2 (E>1 MeV). Charpy V-notch impact tests, static fracture toughness tests, tensile and hardness measurement were performed to obtain effect of neutron fluence on radiation hardening as well as embrittlement. Neutron fluence dependences of all these property changes have monotonic character but with a high neutron embrittlement exponent around 0.8. Scanning electron microscope of fracture surfaces showed no or very small portion of intercrystalline fracture. Transmission electron microscopy was performed on specimens from all neutron fluences. Only low density of black-dot damage has been observed. It is assumed that most of defect are dislocation loops. The late blooming phase which may be observed from results of mechanical properties are probably below the resolution of the used JEM-2010, i.e. 1.5 nm. (authors)

  7. The anisotropy of the cosmic background radiation from local dynamic density perturbations

    International Nuclear Information System (INIS)

    Dyer, C.C.; Ip, P.S.S.

    1988-01-01

    Contrary to the usual assumption, it is shown here that the anisotropy of the cosmic background radiation need not be dominated by perturbations at the last scattering surface. The results of computer simulations are shown in which local dynamic density perturbations, in the form of Swiss cheese holes with finite, uniform density central lumps, are the main source of anisotropy of the cosmic background radiation. (author)

  8. Radiation effects on materials in high-radiation environments

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  9. Level Densities and Radiative Strength Functions in 56FE and 57FE

    Energy Technology Data Exchange (ETDEWEB)

    Tavukcu, Emel [North Carolina State Univ., Raleigh, NC (United States)

    2002-12-10

    Understanding nuclear level densities and radiative strength functions is important for pure and applied nuclear physics. Recently, the Oslo Cyclotron Group has developed an experimental method to extract level densities and radiative strength functions simultaneously from the primary γ rays after a light-ion reaction. A primary γ-ray spectrum represents the γ-decay probability distribution. The Oslo method is based on the Axel-Brink hypothesis, according to which the primary γ-ray spectrum is proportional to the product of the level density at the final energy and the radiative strength function. The level density and the radiative strength function are fit to the experimental primary γ-ray spectra, and then normalized to known data. The method works well for heavy nuclei. The present measurements extend the Oslo method to the lighter mass nuclei 56Fe and 57Fe. The experimental level densities in 56Fe and 57Fe reveal step structure. This step structure is a signature for nucleon pair breaking. The predicted pairing gap parameter is in good agreement with the step corresponding to the first pair breaking. Thermodynamic quantities for 56Fe and 57Fe are derived within the microcanonical and canonical ensembles using the experimental level densities. Energy-temperature relations are considered using caloric curves and probability density functions. The differences between the thermodynamics of small and large systems are emphasized. The experimental heat capacities are compared with the recent theoretical calculations obtained in the Shell Model Monte Carlo method. Radiative strength functions in 56Fe and 57Fe have surprisingly high values at low γ-ray energies. This behavior has not been observed for heavy nuclei, but has been observed in other light- and medium-mass nuclei. The origin of this low γ-ray energy effect remains unknown.

  10. ON THE ORIGIN OF THE HIGH COLUMN DENSITY TURNOVER IN THE H I COLUMN DENSITY DISTRIBUTION

    International Nuclear Information System (INIS)

    Erkal, Denis; Gnedin, Nickolay Y.; Kravtsov, Andrey V.

    2012-01-01

    We study the high column density regime of the H I column density distribution function and argue that there are two distinct features: a turnover at N H I ≈ 10 21 cm –2 , which is present at both z = 0 and z ≈ 3, and a lack of systems above N H I ≈ 10 22 cm –2 at z = 0. Using observations of the column density distribution, we argue that the H I-H 2 transition does not cause the turnover at N H I ≈ 10 21 cm –2 but can plausibly explain the turnover at N H I ∼> 10 22 cm –2 . We compute the H I column density distribution of individual galaxies in the THINGS sample and show that the turnover column density depends only weakly on metallicity. Furthermore, we show that the column density distribution of galaxies, corrected for inclination, is insensitive to the resolution of the H I map or to averaging in radial shells. Our results indicate that the similarity of H I column density distributions at z = 3 and 0 is due to the similarity of the maximum H I surface densities of high-z and low-z disks, set presumably by universal processes that shape properties of the gaseous disks of galaxies. Using fully cosmological simulations, we explore other candidate physical mechanisms that could produce a turnover in the column density distribution. We show that while turbulence within giant molecular clouds cannot affect the damped Lyα column density distribution, stellar feedback can affect it significantly if the feedback is sufficiently effective in removing gas from the central 2-3 kpc of high-redshift galaxies. Finally, we argue that it is meaningful to compare column densities averaged over ∼ kpc scales with those estimated from quasar spectra that probe sub-pc scales due to the steep power spectrum of H I column density fluctuations observed in nearby galaxies.

  11. High Energy Density Capacitors, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Capacitor size and reliability are often limiting factors in pulse power, high speed switching, and power management and distribution (PMAD) systems. T/J...

  12. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    International Nuclear Information System (INIS)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S.

    2015-01-01

    A recent low gas-fill density (0.6 mg/cc 4 He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc 4 He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth

  13. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    Science.gov (United States)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S.

    2015-04-01

    A recent low gas-fill density (0.6 mg/cc 4He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc 4He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

  14. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    Energy Technology Data Exchange (ETDEWEB)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2015-04-15

    A recent low gas-fill density (0.6 mg/cc {sup 4}He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc {sup 4}He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

  15. Spontaneous magnetization in high-density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constanca

    2015-01-01

    It is shown that spontaneous magnetization occurs due to the anomalous magnetic moments of quarks in high-density quark matter under the tensor-type four-point interaction. The spin polarized condensate for each flavor of quark appears at high baryon density, which leads to the spontaneous magnet...

  16. Energy confinement of high-density tokamaks

    NARCIS (Netherlands)

    Schüller, F.C.; Schram, D.C.; Coppi, B.; Sadowski, W.

    1977-01-01

    Neoclassical ion heat conduction is the major energy loss mechanism in the center of an ohmically heated high-d. tokamak discharge (n>3 * 1020 m-3). This fixes the mutual dependence of plasma quantities on the axis and leads to scaling laws for the poloidal b and energy confinement time, given the

  17. Transport simulations of a density limit in radiation-dominated tokamak discharges: II

    International Nuclear Information System (INIS)

    Stotler, D.P.

    1991-05-01

    The procedures developed previously to simulate the radiatively induced tokamak density limit are used to examine in more detail the scaling of the density limit. It is found that the maximum allowable density increases with auxiliary power and decreases with impurity concentration. However, it is demonstrated that there is little dependence of the density limit on plasma elongation. These trends are consistent with experimental results. Our previous work used coronal equilibrium impurities; the primary result of that paper was that the maximum density increases with current when peaked profiles are assumed. Here, this behavior is shown to occur with a coronal nonequilibrium impurity as well. 26 refs., 4 figs

  18. Filter device for high density aerozol

    International Nuclear Information System (INIS)

    Karasawa, Hidetoshi; Endo, Masao; Utamura, Motoaki; Tozuka, Fumio; Tate, Hitoshi.

    1991-01-01

    In a reactor, filters for capturing aerozol particles at high concentration have such a structure that a great number of fine pores are formed. Aerozols are introduced to a filter portion from the place remote from a first inlet. Cloggings are caused successively from the places remote from the inlet. Even if the clogging should occur, since there are many pores, the performance of filters is not deteriorated. Further, the filter has a multi-layered structure. With such a constitution, if the filter at a first stage is clogged to increase the pressure, a partitioning plate is opened and fluids are introduced into a second filter. This is conducted successively to suppress the deterioration of the performance of the filter. In view of the above, even if cloggings should occur, the filter performance is not deteriorated and, accordingly, reactor container ventilation can be conducted at high reliability upon occurrence of accidents. (T.M.)

  19. Radiation interactions in high-pressure gases

    International Nuclear Information System (INIS)

    Christophorou, L.G.

    1990-01-01

    This article is on basic radiation interaction processes in dense fluids and on interphase studies aiming at the interfacing of knowledge on radiation interaction processes in the gaseous and the liquid state of matter. It is specifically focused on the effect of the density and nature of the medium on electron production in irradiated fluids and on the state, energy, transport, and attachment of slow excess electrons in dense fluids especially dielectric liquids which possess excess-electron conduction bands (V 0 < 0 eV). Studies over the past two decades have shown that the interactions of low-energy electrons with molecules embedded in dense media depend not only on the molecules themselves and their internal state of excitation, but also on the electron state and energy in -- and the nature and density of -- the medium in which the interactions occur

  20. Radiation interactions in high-pressure gases

    Energy Technology Data Exchange (ETDEWEB)

    Christophorou, L.G. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA))

    1990-01-01

    This article is on basic radiation interaction processes in dense fluids and on interphase studies aiming at the interfacing of knowledge on radiation interaction processes in the gaseous and the liquid state of matter. It is specifically focused on the effect of the density and nature of the medium on electron production in irradiated fluids and on the state, energy, transport, and attachment of slow excess electrons in dense fluids especially dielectric liquids which possess excess-electron conduction bands (V{sub 0} < 0 eV). Studies over the past two decades have shown that the interactions of low-energy electrons with molecules embedded in dense media depend not only on the molecules themselves and their internal state of excitation, but also on the electron state and energy in -- and the nature and density of -- the medium in which the interactions occur.

  1. High current density ion beam measurement techniques

    International Nuclear Information System (INIS)

    Ko, W.C.; Sawatzky, E.

    1976-01-01

    High ion beam current measurements are difficult due to the presence of the secondary particles and beam neutralization. For long Faraday cages, true current can be obtained only by negative bias on the target and by summing the cage wall and target currents; otherwise, the beam will be greatly distorted. For short Faraday cages, a combination of small magnetic field and the negative target bias results in correct beam current. Either component alone does not give true current

  2. The creation of high energy densities with antimatter beams

    International Nuclear Information System (INIS)

    Gibbs, W.R.; Kruk, J.W.; Rice Univ., Houston, TX

    1989-01-01

    The use of antiprotons (and antideuterons) for the study of the behavior of nuclear matter at high energy density is considered. It is shown that high temperatures and high energy densities can be achieved for small volumes. Also investigated is the strangeness production in antimatter annihilation. It is found that the high rate of Lambda production seen in a recent experiment is easily understood. The Lambda and K-short rapidity distributions are also reproduced by the model considered. 11 refs., 6 figs

  3. Level Densities and Radiative Strength Functions in 170,171Yb

    International Nuclear Information System (INIS)

    Agvaanluvsan, U.; Schiller, A.; Becker, J.A.; Berstein, L.A.; Guttormsen, M.; Mitchell, G.E.; Rekstad, J.; Siem, S.; Voinov, A.

    2003-01-01

    Level densities and radiative strength functions in 171 Yb and 170 Yb nuclei have been measured with the 171 Yb( 3 He, 3 He(prime) γ) 171 Yb and 171 Yb( 3 He, αγ) 170 Yb reactions. A simultaneous determination of the nuclear level density and the radiative strength function was made. The present data adds to and is consistent with previous results for several other rare earth nuclei. The method will be briefly reviewed and the result from the analysis will be presented. The radiative strength function for 171 Yb is compared to previously published work.

  4. Numerical analysis of energy density and particle density in high energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Fu Yuanyong; Lu Zhongdao

    2004-01-01

    Energy density and particle density in high energy heavy-ion collisions are calculated with infinite series expansion method and Gauss-Laguerre formulas in numerical integration separately, and the results of these two methods are compared, the higher terms and linear terms in series expansion are also compared. The results show that Gauss-Laguerre formulas is a good method in calculations of high energy heavy-ion collisions. (author)

  5. Spectroscopic investigations of high-energy-density\

    Czech Academy of Sciences Publication Activity Database

    Civiš, Martin; Ferus, Martin; Knížek, Antonín; Kubelík, Petr; Kamas, Michal; Španěl, Patrik; Dryahina, Kseniya; Shestivska, Violetta; Juha, Libor; Skřehot, P.; Laitl, V.; Civiš, Svatopluk

    2016-01-01

    Roč. 18, č. 39 (2016), s. 27317-27325 ISSN 1463-9076 R&D Projects: GA ČR(CZ) GA14-12010S; GA MŠk LG15013; GA MŠk(CZ) LM2015083 Grant - others:Akademie věd - GA AV ČR(CZ) R200401521 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : HIGH-POWER LASER * INDUCED DIELECTRIC-BREAKDOWN * EARTHS EARLY ATMOSPHERE Subject RIV: CF - Physical ; Theoretical Chemistry; BL - Plasma and Gas Discharge Physics (FZU-D) Impact factor: 4.123, year: 2016

  6. Transport simulations of a density limit in radiation-dominated tokamak discharges: profile effects

    International Nuclear Information System (INIS)

    Stotler, D.P.

    1988-01-01

    The density limit observed in tokamak experiments is thought to be due to a radiative collapse of the current channel. A transport code coupled with a magnetohydrodynamic (MHD) equilibrium routine is used to determine the detailed, self-consistent evolution of the plasma profiles in tokamak discharges with radiated power close to or equaling the input power. The present work is confined to Ohmic discharges in steady state. It is found that the shape of the density profile can have a significant impact on the variation of the maximum electron density with plasma current. Analytic calculations confirm this result

  7. Transport simulations of a density limit in radiation-dominated tokamak discharges: Profile effects

    International Nuclear Information System (INIS)

    Stotler, D.P.

    1988-06-01

    The density limit observed in tokamak experiments is thought to be due to a radiative collapse of the current channel. A transport code coupled with an MHD equilibrium routine is used to determine the detailed, self-consistent evolution of the plasma profiles in tokamak discharges with radiated power close to or equalling the input power. The present work is confined to ohmic discharges in steady state. It is found that the shape of the density profile can have a significant impact on the variation of the maximum electron density with plasma current. Analytic calculations confirm this result. 41 refs., 9 figs

  8. Study of effects gamma radiation linear low density polyethylene (LLDPE) injected

    International Nuclear Information System (INIS)

    Oliveira, Ana Claudia Feitoza de

    2014-01-01

    The use of package sterilization through gamma radiation aim to reduce the microbiological contamination. The linear low density polyethylene (LLDPE) can be obtained by a process in solution, suspension or gaseous phase, depending on the type of the catalyzer used, that can be heterogeneous, or homogeneous, or metallocenes Ziegler-Natta. According to the literature, the gamma radiation presents a high penetration at polymeric materials causing the appearing of scissions, reticulation, and degradation when oxygen presence. This paper were irradiated with 60 Co with 2000 kCi of activity, in presence of air, samples of LLDPE injected. Utilized doses of 5, 10, 20, 50 or 100 kGy, and about 5 kGy.h -1 dose rates, at room temperature. After irradiation, the samples were heated for 60 min at 100 deg C to promote recombination and annihilation of residual radicals. For characterization of PEBLD were used methods; Melt flow index, swelling, gel fraction, Fourier Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (DRX), Thermogravimetric Analysis (TG), Dynamic Mechanical Analysis (DMA), rheological measurements, Scanning Electronic Microscopy and mechanical tests to identify the effects or gamma radiation in polyethylene. (author)

  9. The contribution of accreting black holes to the background radiation density

    International Nuclear Information System (INIS)

    Carr, B.J.

    1979-01-01

    Black holes could generate radiation as a result of accretion. The requirement that this radiation should not have a density exceeding the observed background density places an interesting limit on the number of black holes, depending on the wavelength at which the radiation is generated and the efficiency with which it is produced from accreted material. Consideration of the radiation produced in the present epoch already constrains the mass range in which black holes could have a significant cosmological density. For pregalactic black holes, which may have been accreting more rapidly in the past, the constraint could be even stronger. However, because pregalactic accretion will in general increase the matter temperature of the Universe, it is a self-limiting process. For this reason the pregalactic accretion limit is not as strong as one might naively expect and it is generally weaker than the present epoch limit. (author)

  10. Fiber optics in high dose radiation fields

    International Nuclear Information System (INIS)

    Partin, J.K.

    1985-01-01

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

  11. High-energy-density physics foundation of inertial fusion and experimental astrophysics

    CERN Document Server

    Drake, R Paul

    2018-01-01

    The raw numbers of high-energy-density physics are amazing: shock waves at hundreds of km/s (approaching a million km per hour), temperatures of millions of degrees, and pressures that exceed 100 million atmospheres. This title surveys the production of high-energy-density conditions, the fundamental plasma and hydrodynamic models that can describe them and the problem of scaling from the laboratory to the cosmos. Connections to astrophysics are discussed throughout. The book is intended to support coursework in high-energy-density physics, to meet the needs of new researchers in this field, and also to serve as a useful reference on the fundamentals. Specifically the book has been designed to enable academics in physics, astrophysics, applied physics and engineering departments to provide in a single-course, an introduction to fluid mechanics and radiative transfer, with dramatic applications in the field of high-energy-density systems. This second edition includes pedagogic improvements to the presentation ...

  12. Foundations of high-energy-density physics physical processes of matter at extreme conditions

    CERN Document Server

    Larsen, Jon

    2017-01-01

    High-energy-density physics explores the dynamics of matter at extreme conditions. This encompasses temperatures and densities far greater than we experience on Earth. It applies to normal stars, exploding stars, active galaxies, and planetary interiors. High-energy-density matter is found on Earth in the explosion of nuclear weapons and in laboratories with high-powered lasers or pulsed-power machines. The physics explored in this book is the basis for large-scale simulation codes needed to interpret experimental results whether from astrophysical observations or laboratory-scale experiments. The key elements of high-energy-density physics covered are gas dynamics, ionization, thermal energy transport, and radiation transfer, intense electromagnetic waves, and their dynamical coupling. Implicit in this is a fundamental understanding of hydrodynamics, plasma physics, atomic physics, quantum mechanics, and electromagnetic theory. Beginning with a summary of the topics and exploring the major ones in depth, thi...

  13. Physics of intense, high energy radiation effects.

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-01

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

  14. Physics of intense, high energy radiation effects

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  15. High baryon density from relativistic heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Y.; Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States); Schlagel, T.J. [Brookhaven National Lab., Upton, NY (United States)]|[State Univ. of New York, Stony Brook, NY (United States)

    1993-10-01

    A quantitative model, based on hadronic physics, is developed and applied to heavy ion collisions at BNL-AGS energies. This model is in excellent agreement with observed particle spectra in heavy ion collisions using Si beams, where baryon densities of three and four times the normal nuclear matter density ({rho}{sub 0}) are reached. For Au on Au collisions, the authors predict the formation of matter at very high densities (up to 10 {rho}{sub 0}).

  16. Lexical Density Of English Reading Texts For Senior High School

    OpenAIRE

    Nesia, Bersyebah Herljimsi; Ginting, Siti Aisah

    2014-01-01

    This study deals with the lexical density especially the lexical items of English reading texts in the textbook for senior high school. The objectives of the study are to find out the lexical density especially the lexical items which formed in the reading texts of Look Ahead textbook and the type of genre which has the highest lexical density of the reading texts. This study was conducted by descriptive method with qualitative approach. The data of this research were the English reading text...

  17. Volume generation of negative ions in high density hydrogen discharges

    International Nuclear Information System (INIS)

    Hiskes, J.R.; Karo, A.M.

    1983-01-01

    A parametric survey is made of a high-density tandem two-chamber hydrogen negative ion system. The optimum extracted negative ion current densities are sensitive to the atom concentration in the discharge and to the system scale length. For scale lengths ranging from 10 cm to 0.1 cm optimum current densities range from of order 1 to 100 mA cm -2 , respectively

  18. Transformation of solar radiation in Norway spruce stands into produced biomass - the effect of stand density

    International Nuclear Information System (INIS)

    Marková, I.; Marek, M.V.; Pokorný, R.

    2011-01-01

    The present paper is focused on the assessment of the effects of stand density and leaf area development on radiation use efficiency in the mountain cultivated Norway spruce stand. The young even-aged (17-years-old in 1998) plantation of Norway spruce was divided into two experimental plots differing in their stand density in 1995. During the late spring of 2001 next cultivating high-type of thinning of 15% intensity in a reduction of stocking density was performed. The PAR regime of investigated stands was continually measured since 1992. Total aboveground biomass (TBa) and TBa increment were obtained on the basis of stand inventory. The dynamic of LAI development showed a tendency to be saturated, i.e. the LAI value close to 11 seems to be maximal for the local conditions of the investigated mountain cultivated Norway spruce stand in the Beskids Mts. Remarkable stimuli (up to 17%) of LAI formation were started in 2002, i.e. as an immediate response to thinning. Thus, the positive effect of thinning on LAI increase was confirmed. The data set of absorbed PAR and produced TBa in the period 1998-2003 was processed by the linear regression of Monteith's model, which provided the values of the coefficient of solar energy conversion efficiency into biomass formation. The differences in biomass formation values between the dense and sparse plot after thinning amounted to 18%

  19. Radiation monitoring in high energy research facility

    International Nuclear Information System (INIS)

    Miyajima, Mitsuhiro

    1975-01-01

    In High Energy Physics Research Laboratory, construction of high energy proton accelerator is in progress. The accelerator is a cascaded machine comprising Cockcroft type (50 keV), linac (20 MeV), booster synchrotron (500 MeV), and synchrotron (8-12 GeV). Its proton beam intensity is 1x10 13 photons/pulse, and acceleration is carried out at the rate of every 2 minutes. The essential problems of radiation control in high energy accelerators are those of various radiations generated secondarily by proton beam and a number of induced radiations simultaneously originated with such secondary particles. In the Laboratory, controlled areas are divided into color-coded four regions, red, orange, yellow and green, based on each dose-rate. BF 3 counters covered with thick paraffin are used as neutron detectors, and side-window GM tubes, NaI (Tl) scintillators and ionization chambers as γ-detectors. In red region, however, ionization chambers are applied to induced radiation detection, and neutrons are not monitored. NIM standards are adopted for the circuits of all above monitors considering easy maintenance, economy and interchangeability. Notwithstanding the above described systems, these monitors are not sufficient to complete the measurement of whole radiations over wide energy region radiated from the accelerators. Hence separate radiation field measurement is required periodically. An example of the monitoring systems in National Accelerator Laboratory (U.S.) is referred at the last section. (Wakatsuki, Y.)

  20. Lognormal Kalman filter for assimilating phase space density data in the radiation belts

    Science.gov (United States)

    Kondrashov, D.; Ghil, M.; Shprits, Y.

    2011-11-01

    Data assimilation combines a physical model with sparse observations and has become an increasingly important tool for scientists and engineers in the design, operation, and use of satellites and other high-technology systems in the near-Earth space environment. Of particular importance is predicting fluxes of high-energy particles in the Van Allen radiation belts, since these fluxes can damage spaceborne platforms and instruments during strong geomagnetic storms. In transiting from a research setting to operational prediction of these fluxes, improved data assimilation is of the essence. The present study is motivated by the fact that phase space densities (PSDs) of high-energy electrons in the outer radiation belt—both simulated and observed—are subject to spatiotemporal variations that span several orders of magnitude. Standard data assimilation methods that are based on least squares minimization of normally distributed errors may not be adequate for handling the range of these variations. We propose herein a modification of Kalman filtering that uses a log-transformed, one-dimensional radial diffusion model for the PSDs and includes parameterized losses. The proposed methodology is first verified on model-simulated, synthetic data and then applied to actual satellite measurements. When the model errors are sufficiently smaller then observational errors, our methodology can significantly improve analysis and prediction skill for the PSDs compared to those of the standard Kalman filter formulation. This improvement is documented by monitoring the variance of the innovation sequence.

  1. Apparatus and method for generating high density pulses of electrons

    International Nuclear Information System (INIS)

    Lee, C.; Oettinger, P.E.

    1981-01-01

    An apparatus and method are described for the production of high density pulses of electrons using a laser energized emitter. Caesium atoms from a low pressure vapour atmosphere are absorbed on and migrate from a metallic target rapidly heated by a laser to a high temperature. Due to this heating time being short compared with the residence time of the caesium atoms adsorbed on the target surface, copious electrons are emitted which form a high current density pulse. (U.K.)

  2. Low density, variation in sintered density and high nitrogen in uranium dioxide

    International Nuclear Information System (INIS)

    Balakrishna, Palanki; Murty, B.N.; Anuradha, M.; Nageshwara Rao, P.; Jayaraj, R.N.; Ganguly, C.

    2000-01-01

    Low sintered density and density variation in sintered UO 2 were found to have been caused by non uniformity in the granule feed characteristics to the compacting press. The nitrogen impurity content of sintered UO 2 was found to be sintering furnace related and associated with low sintered density pellets. The problems of low density, variation in sintered density and high nitrogen could be solved by the replacement of the prevailing four punch precompaction by a single punch process; by the introduction of a vibro-sieve for the separation of fine particles from the press feed granules; by innovation in the powder feed shoe design for simultaneous and uniform dispensing of powder in all the die holes; by increasing the final compaction pressure and by modifying the gas flows and preheat temperature in the sintering furnace. (author)

  3. Epidemiological studies in high background radiation areas

    International Nuclear Information System (INIS)

    Akiba, Suminori

    2012-01-01

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

  4. Properties of matter at ultra-high densities

    International Nuclear Information System (INIS)

    Banerjee, B.; Chitre, S.M.

    1975-01-01

    The recent discovery of pulsars and their subsequent identification with neutron stars has given a great impetus to the study of the behaviour of matter at ultra high densities. The object of these studies is to calculate the equation of state as a function of density. In this paper, the properties of electrically neutral, cold (T=0) matter at unusually high densities has been reviewed. The physics of the equation of state of such matter divides quite naturally in four density ranges. (i) At the very lowest densities the state of minimum energy is a lattice of 56 Fe atoms. This state persists upto 10 7 g/cm 3 . (ii) In the next density region the nuclei at the lattice sites become neutron rich because the high electron Fermi energy makes inverse beta decay possible. (iii) At a density 4.3 x 10 11 the nuclei become so neutron rich that the neutrons start 'dripping' out of the nuclei and form a gas. This density range is characterised by large, neutron-rich nuclei immersed in a neutron gas. (iv) At a density 2.4 x 10 14 g/cm 3 , the nuclei disappear and a fluid of uniform neutron matter with a small percentage of protons and electrons results. The above four density ranges have been discussed in detail as the equation of state is now well established upto the nuclear density 3 x 10 14 g/cm 3 . The problems of extending the equation of state beyond this density are also touched upon. (author)

  5. Key issues of ultraviolet radiation of OH at high altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhuai; Wan, Tian; Jiang, Jianzheng; Fan, Jing [State Key Laboratory of High Temperature Gasdynamics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-12-09

    Ultraviolet (UV) emissions radiated by hydroxyl (OH) is one of the fundamental elements in the prediction of radiation signature of high-altitude and high-speed vehicle. In this work, the OH A{sup 2}Σ{sup +}→X{sup 2}Π ultraviolet emission band behind the bow shock is computed under the experimental condition of the second bow-shock ultraviolet flight (BSUV-2). Four related key issues are discussed, namely, the source of hydrogen element in the high-altitude atmosphere, the formation mechanism of OH species, efficient computational algorithm of trace species in rarefied flows, and accurate calculation of OH emission spectra. Firstly, by analyzing the typical atmospheric model, the vertical distributions of the number densities of different species containing hydrogen element are given. According to the different dominating species containing hydrogen element, the atmosphere is divided into three zones, and the formation mechanism of OH species is analyzed in the different zones. The direct simulation Monte Carlo (DSMC) method and the Navier-Stokes equations are employed to compute the number densities of the different OH electronically and vibrationally excited states. Different to the previous work, the trace species separation (TSS) algorithm is applied twice in order to accurately calculate the densities of OH species and its excited states. Using a non-equilibrium radiation model, the OH ultraviolet emission spectra and intensity at different altitudes are computed, and good agreement is obtained with the flight measured data.

  6. BCS Theory of Hadronic Matter at High Densities

    DEFF Research Database (Denmark)

    Bohr, Henrik; Panda, Prafulla K.; Providencia, Constanca

    2012-01-01

    The equilibrium between the so-called 2SC and CFL phases of strange quark matter at high densities is investigated in the framework of a simple schematic model of the NJL type. Equal densities are assumed for quarks u, d and s. The 2SC phase is here described by a color-flavor symmetric state, in...

  7. Phenomenology of high density disruptions in the TFTR tokamak

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; McGuire, K.M.; Bell, M.G.

    1993-01-01

    Studies of high density disruptions on TFTR, including a comparison of minor and major disruptions at high density, provide important new information regarding the nature of the disruption mechanism. Further, for the first time, an (m,n)=(1,1) 'cold bubble' precursor to high density disruptions has been experimentally observed in the electron temperature profile. The precursor to major disruptions resembles the 'vacuum bubble' model of disruptions first proposed by B.B. Kadomtsev and O.P. Pogutse (Sov. Phys. - JETP 38 (1974) 283). (author). Letter-to-the-editor. 25 refs, 3 figs

  8. High-density-plasma diagnostics in magnetic-confinement fusion

    International Nuclear Information System (INIS)

    Jahoda, F.C.

    1982-01-01

    The lectures will begin by defining high density in the context of magnetic confinement fusion research and listing some alternative reactor concepts, ranging from n/sub e/ approx. 2 x 10 14 cm -3 to several orders of magnitude greater, that offer potential advantages over the main-line, n/sub e/ approx. 1 x 10 14 cm -3 , Tokamak reactor designs. The high density scalings of several major diagnostic techniques, some favorable and some disadvantageous, will be discussed. Special emphasis will be given to interferometric methods, both electronic and photographic, for which integral n/sub e/dl measurements and associated techniques are accessible with low wavelength lasers. Reactor relevant experience from higher density, smaller dimension devices exists. High density implies high β, which implies economies of scale. The specialized features of high β diagnostics will be discussed

  9. Annihilation Radiation Gauge for Relative Density and Multiphase Fluid Monitoring

    Directory of Open Access Journals (Sweden)

    Vidal A.

    2014-03-01

    Full Text Available The knowledge of the multi-phase flow parameters are important for the petroleum industry, specifically during the transport in pipelines and network related to exploitation’s wells. Crude oil flow is studied by Monte Carlo simulation and experimentally to determine transient liquid phase in a laboratory system. Relative density and fluid phase time variation is monitored employing a fast nuclear data acquisition setup that includes two large volume BaF2 scintillator detectors coupled to an electronic chain and data display in a LabView® environment. Fluid parameters are determined by the difference in count rate of coincidence pulses. The operational characteristics of the equipment indicate that 2 % deviation in the CCR corresponds to a variation, on average, of 20 % in the fraction of liquid of the multiphase fluid.

  10. Production of an economic high-density concrete for shielding megavoltage radiotherapy rooms and nuclear reactors

    International Nuclear Information System (INIS)

    Mortazavi, S. M. J.; Mosleh-Shirazi, M. A.; Maheri, M. R.; Haji-pour, A.; Yousefnia, H.; Zolghadri, S.

    2007-01-01

    In megavoltage radiotherapy rooms, ordinary concrete is usually used due to its low construction costs, although higher density concrete are sometimes used, as well. The use of high-density concrete decreases the required thickness of the concrete barrier; hence, its disadvantage is its high cost. In a nuclear reactor, neutron radiation is the most difficult to shield. A method for production of economic high-density concrete witt, appropriate engineering properties would be very useful. Materials and Methods: Galena (Pb S) mineral was used to produce of a high-density concrete. Galena can be found in many parts of Iran. Two types of concrete mixes were produced. The water-to-concrete (w/c) ratios of the reference and galena concrete mixes were 0.53 and 0.25, respectively. To measure the gamma radiation attenuation of Galena concrete samples, they were exposed to a narrow beam of gamma rays emitted from a cobalt-60 therapy unit. Results: The Galena mineral used in this study had a density of 7400 kg/m 3 . The concrete samples had a density of 4800 kg/m 3 . The measured half value layer thickness of the Galena concrete samples for cobalt 60 gamma rays was much less than that of ordinary concrete (2.6 cm compared to 6.0 cm). Furthermore, the galena concrete samples had significantly higher compressive strength (500 kg/cm 2 compared to 300 kg/cm 2 ). Conclusion: The Galena concrete samples made in our laboratories had showed good shielding/engineering properties in comparison with all samples made by using high-density materials other than depleted uranium. Based on the preliminary results, Galena concrete is maybe a suitable option where high-density concrete is required in megavoltage radiotherapy rooms as well as nuclear reactors

  11. Radiation cured coatings for high performance products

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  12. High Power Density Power Electronic Converters for Large Wind Turbines

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk

    . For these VSCs, high power density is required due to limited turbine nacelle space. Also, high reliability is required since maintenance cost of these remotely located wind turbines is quite high and these turbines operate under harsh operating conditions. In order to select a high power density and reliability......In large wind turbines (in MW and multi-MW ranges), which are extensively utilized in wind power plants, full-scale medium voltage (MV) multi-level (ML) voltage source converters (VSCs) are being more preferably employed nowadays for interfacing these wind turbines with electricity grids...... VSC solution for wind turbines, first, the VSC topology and the switch technology to be employed should be specified such that the highest possible power density and reliability are to be attained. Then, this qualitative approach should be complemented with the power density and reliability...

  13. High energy radiation in cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-10-15

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

  14. High energy radiation in cancer treatment

    International Nuclear Information System (INIS)

    1959-01-01

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

  15. Workshop on extremely high energy density plasmas and their diagnostics

    International Nuclear Information System (INIS)

    Ishii, Shozo

    2001-09-01

    Compiled are the papers presented at the workshop on 'Extremely High Energy Density Plasmas and Their Diagnostics' held at National Institute for Fusion Science. The papers cover physics and applications of extremely high-energy density plasmas such as dense z-pinch, plasma focus, and intense pulsed charged beams. Separate abstracts were presented for 7 of the papers in this report. The remaining 25 were considered outside the subject scope of INIS. (author)

  16. High density UO2 powder preparation for HWR fuel

    International Nuclear Information System (INIS)

    Hwang, S. T.; Chang, I. S.; Choi, Y. D.; Cho, B. R.; Kwon, S. W.; Kim, B. H.; Moon, B. H.; Kim, S. D.; Phyu, K. M.; Lee, K. A.

    1992-01-01

    The objective of this project is to study on the preparation of method high density UO 2 powder for HWR Fuel. Accordingly, it is necessary to character ize the AUC processed UO 2 powder and to search method for the preparation of high density UO 2 powder for HWR Fuel. Therefore, it is expected that the results of this study can effect the producing of AUC processed UO 2 powder having sinterability. (Author)

  17. Density-dependent phonoriton states in highly excited semiconductors

    International Nuclear Information System (INIS)

    Nguyen Hong Quang; Nguyen Minh Khue; Nguyen Que Huong

    1995-09-01

    The dynamical aspects of the phonoriton state in highly-photoexcited semiconductors is studied theoretically. The effect of the exciton-exciton interaction and nonbosonic character of high-density excitons are taken into account. Using Green's function method and within the Random Phase Approximation it is shown that the phonoriton dispersion and damping are very sensitive to the exciton density, characterizing the excitation degree of semiconductors. (author). 18 refs, 3 figs

  18. Fifth International Conference on High Energy Density Physics

    Energy Technology Data Exchange (ETDEWEB)

    Beg, Farhat

    2017-07-05

    The Fifth International Conference on High Energy Density Physics (ICHED 2015) was held in the Catamaran Hotel in San Diego from August 23-27, 2015. This meeting was the fifth in a series which began in 2008 in conjunction with the April meeting of the American Physical Society (APS). The main goal of this conference has been to bring together researchers from all fields of High Energy Density Science (HEDS) into one, unified meeting.

  19. Workshop on extremely high energy density plasmas and their diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Shozo (ed.)

    2001-09-01

    Compiled are the papers presented at the workshop on 'Extremely High Energy Density Plasmas and Their Diagnostics' held at National Institute for Fusion Science. The papers cover physics and applications of extremely high-energy density plasmas such as dense z-pinch, plasma focus, and intense pulsed charged beams. Separate abstracts were presented for 7 of the papers in this report. The remaining 25 were considered outside the subject scope of INIS. (author)

  20. The high density effects in the Drell-Yan process

    International Nuclear Information System (INIS)

    Betemps, M.A.; Gay Ducati, M.B.; Ayala Filho, A.L.

    2003-01-01

    The high density effects in the Drell-Yan process (q q-bar → γ * →l + l - ) are investigated for pA collisions at RHIC and LHC energies. In particular, we use a set of nuclear parton distributions that describes the present nuclear eA and pA data in the DGLAP approach including the high density effects introduced in the perturbative Glauber-Mueller approach. (author)

  1. Individual Dosimetry for High Energy Radiation Fields

    International Nuclear Information System (INIS)

    Spurny, F.

    1999-01-01

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

  2. Biological effects of high-energy radiation

    International Nuclear Information System (INIS)

    Curtis, S.B.

    1976-01-01

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

  3. Still rethinking the value of high wood density.

    Science.gov (United States)

    Larjavaara, Markku; Muller-Landau, Helene C

    2012-01-01

    In a previous paper, we questioned the traditional interpretation of the advantages and disadvantages of high wood density (Functional Ecology 24: 701-705). Niklas and Spatz (American Journal of Botany 97: 1587-1594) challenged the biomechanical relevance of studying properties of dry wood, including dry wood density, and stated that we erred in our claims regarding scaling. We first present the full derivation of our previous claims regarding scaling. We then examine how the fresh modulus of rupture and the elastic modulus scale with dry wood density and compare these scaling relationships with those for dry mechanical properties, using almost exactly the same data set analyzed by Niklas and Spatz. The derivation shows that given our assumptions that the modulus of rupture and elastic modulus are both proportional to wood density, the resistance to bending is inversely proportional to wood density and strength is inversely proportional with the square root of wood density, exactly as we previously claimed. The analyses show that the elastic modulus of fresh wood scales proportionally with wood density (exponent 1.05, 95% CI 0.90-1.11) but that the modulus of rupture of fresh wood does not, scaling instead with the 1.25 power of wood density (CI 1.18-1.31). The deviation from proportional scaling for modulus of rupture is so small that our central conclusion remains correct: for a given construction cost, trees with lower wood density have higher strength and higher resistance to bending.

  4. High intensity radiation imaging system

    International Nuclear Information System (INIS)

    Barrett, H.H.

    1976-01-01

    A nuclear imaging system is described for mapping a spatially distributed source of high energy nuclear particles from a living organ which has selectively absorbed a radioactive compound in which the nuclear energy is spatially coded by a zone plate positioned between the source and a spatial detector, and a half tone screen is positioned between the source and the zone plate to increase the definition of the image

  5. Physics and applications of high energy density plasmas. Extreme state driven by pulsed electromagnetic energy

    Energy Technology Data Exchange (ETDEWEB)

    Horioka, Kazuhiko (ed.)

    2002-06-01

    The papers presented at the symposium on ''Physics and application of high energy density plasmas, held December 20-21, 2001 at NIFS'' are collected in this proceedings. The topics covered in the meeting include dense z-pinches, plasma focus, intense charged particle beams, intense radiation sources, discharge pumped X-ray lasers, their diagnostics, and applications of them. The papers reflect the present status and trends in the research field of high energy density plasmas. (author)

  6. Development of Advanced High Uranium Density Fuels for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, James [Univ. of Wisconsin, Madison, WI (United States); Butt, Darryl [Boise State Univ., ID (United States); Meyer, Mitchell [Idaho National Lab. (INL), Idaho Falls, ID (United States); Xu, Peng [Westinghouse Electric Corporation, Pittsburgh, PA (United States)

    2016-02-15

    This work conducts basic materials research (fabrication, radiation resistance, thermal conductivity, and corrosion response) on U3Si2 and UN, two high uranium density fuel forms that have a high potential for success as advanced light water reactor (LWR) fuels. The outcome of this proposed work will serve as the basis for the development of advance LWR fuels, and utilization of such fuel forms can lead to the optimization of the fuel performance related plant operating limits such as power density, power ramp rate and cycle length.

  7. Breast density estimation from high spectral and spatial resolution MRI

    Science.gov (United States)

    Li, Hui; Weiss, William A.; Medved, Milica; Abe, Hiroyuki; Newstead, Gillian M.; Karczmar, Gregory S.; Giger, Maryellen L.

    2016-01-01

    Abstract. A three-dimensional breast density estimation method is presented for high spectral and spatial resolution (HiSS) MR imaging. Twenty-two patients were recruited (under an Institutional Review Board--approved Health Insurance Portability and Accountability Act-compliant protocol) for high-risk breast cancer screening. Each patient received standard-of-care clinical digital x-ray mammograms and MR scans, as well as HiSS scans. The algorithm for breast density estimation includes breast mask generating, breast skin removal, and breast percentage density calculation. The inter- and intra-user variabilities of the HiSS-based density estimation were determined using correlation analysis and limits of agreement. Correlation analysis was also performed between the HiSS-based density estimation and radiologists’ breast imaging-reporting and data system (BI-RADS) density ratings. A correlation coefficient of 0.91 (pdensity estimations. An interclass correlation coefficient of 0.99 (pdensity estimations. A moderate correlation coefficient of 0.55 (p=0.0076) was observed between HiSS-based breast density estimations and radiologists’ BI-RADS. In summary, an objective density estimation method using HiSS spectral data from breast MRI was developed. The high reproducibility with low inter- and low intra-user variabilities shown in this preliminary study suggest that such a HiSS-based density metric may be potentially beneficial in programs requiring breast density such as in breast cancer risk assessment and monitoring effects of therapy. PMID:28042590

  8. Terrestrial gamma radiation baseline mapping using ultra low density sampling methods.

    Science.gov (United States)

    Kleinschmidt, R; Watson, D

    2016-01-01

    Baseline terrestrial gamma radiation maps are indispensable for providing basic reference information that may be used in assessing the impact of a radiation related incident, performing epidemiological studies, remediating land contaminated with radioactive materials, assessment of land use applications and resource prospectivity. For a large land mass, such as Queensland, Australia (over 1.7 million km(2)), it is prohibitively expensive and practically difficult to undertake detailed in-situ radiometric surveys of this scale. It is proposed that an existing, ultra-low density sampling program already undertaken for the purpose of a nationwide soil survey project be utilised to develop a baseline terrestrial gamma radiation map. Geoelement data derived from the National Geochemistry Survey of Australia (NGSA) was used to construct a baseline terrestrial gamma air kerma rate map, delineated by major drainage catchments, for Queensland. Three drainage catchments (sampled at the catchment outlet) spanning low, medium and high radioelement concentrations were selected for validation of the methodology using radiometric techniques including in-situ measurements and soil sampling for high resolution gamma spectrometry, and comparative non-radiometric analysis. A Queensland mean terrestrial air kerma rate, as calculated from the NGSA outlet sediment uranium, thorium and potassium concentrations, of 49 ± 69 nGy h(-1) (n = 311, 3σ 99% confidence level) is proposed as being suitable for use as a generic terrestrial air kerma rate background range. Validation results indicate that catchment outlet measurements are representative of the range of results obtained across the catchment and that the NGSA geoelement data is suitable for calculation and mapping of terrestrial air kerma rate. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  9. Fluorescent Fe K Emission from High Density Accretion Disks

    Science.gov (United States)

    Bautista, Manuel; Mendoza, Claudio; Garcia, Javier; Kallman, Timothy R.; Palmeri, Patrick; Deprince, Jerome; Quinet, Pascal

    2018-06-01

    Iron K-shell lines emitted by gas closely orbiting black holes are observed to be grossly broadened and skewed by Doppler effects and gravitational redshift. Accordingly, models for line profiles are widely used to measure the spin (i.e., the angular momentum) of astrophysical black holes. The accuracy of these spin estimates is called into question because fitting the data requires very high iron abundances, several times the solar value. Meanwhile, no plausible physical explanation has been proffered for why these black hole systems should be so iron rich. The most likely explanation for the super-solar iron abundances is a deficiency in the models, and the leading candidate cause is that current models are inapplicable at densities above 1018 cm-3. We study the effects of high densities on the atomic parameters and on the spectral models for iron ions. At high densities, Debye plasma can affect the effective atomic potential of the ions, leading to observable changes in energy levels and atomic rates with respect to the low density case. High densities also have the effec of lowering energy the atomic continuum and reducing the recombination rate coefficients. On the spectral modeling side, high densities drive level populations toward a Boltzman distribution and very large numbers of excited atomic levels, typically accounted for in theoretical spectral models, may contribute to the K-shell spectrum.

  10. Comparison of low density and high density pedicle screw instrumentation in Lenke 1 adolescent idiopathic scoliosis.

    Science.gov (United States)

    Shen, Mingkui; Jiang, Honghui; Luo, Ming; Wang, Wengang; Li, Ning; Wang, Lulu; Xia, Lei

    2017-08-02

    The correlation between implant density and deformity correction has not yet led to a precise conclusion in adolescent idiopathic scoliosis (AIS). The aim of this study was to evaluate the effects of low density (LD) and high density (HD) pedicle screw instrumentation in terms of the clinical, radiological and Scoliosis Research Society (SRS)-22 outcomes in Lenke 1 AIS. We retrospectively reviewed 62 consecutive Lenke 1 AIS patients who underwent posterior spinal arthrodesis using all-pedicle screw instrumentation with a minimum follow-up of 24 months. The implant density was defined as the number of screws per spinal level fused. Patients were then divided into two groups according to the average implant density for the entire study. The LD group (n = 28) had fewer than 1.61 screws per level, while the HD group (n = 34) had more than 1.61 screws per level. The radiographs were analysed preoperatively, postoperatively and at final follow-up. The perioperative and SRS-22 outcomes were also assessed. Independent sample t tests were used between the two groups. Comparisons between the two groups showed no significant differences in the correction of the main thoracic curve and thoracic kyphosis, blood transfusion, hospital stay, and SRS-22 scores. Compared with the HD group, there was a decreased operating time (278.4 vs. 331.0 min, p = 0.004) and decreased blood loss (823.6 vs. 1010.9 ml, p = 0.048), pedicle screws needed (15.1 vs. 19.6, p density and high density pedicle screw instrumentation achieved satisfactory deformity correction in Lenke 1 AIS patients. However, the operating time and blood loss were reduced, and the implant costs were decreased with the use of low screw density constructs.

  11. High dislocation density of tin induced by electric current

    International Nuclear Information System (INIS)

    Liao, Yi-Han; Liang, Chien-Lung; Lin, Kwang-Lung; Wu, Albert T.

    2015-01-01

    A dislocation density of as high as 10 17 /m 2 in a tin strip, as revealed by high resolution transmission electron microscope, was induced by current stressing at 6.5 x 10 3 A/ cm 2 . The dislocations exist in terms of dislocation line, dislocation loop, and dislocation aggregates. Electron Backscattered Diffraction images reflect that the high dislocation density induced the formation of low deflection angle subgrains, high deflection angle Widmanstätten grains, and recrystallization. The recrystallization gave rise to grain refining

  12. Low radiation dose impact on human bone mineral density

    International Nuclear Information System (INIS)

    Zaichick, V.E.

    2002-01-01

    osteoporosis in two groups of cleaners different from each other by the level of external total body irradiation (up to 10 cSv and between 11 and 25 cSv) was about the same. This fact shows no significant effect of factor 1 with a radiation dose of not more than 25 cSv. The highest incidence of osteopenia and osteoporosis (78 %) was found in the group of cleaners working in Chernobyl in 1986 that may be related to the action of factors 2 and 3. Because the group of exposed men who were studied was selected randomly, it can be concluded that even by 2002 more than 50 % of the cleaners still had clear changes in the mineral component of the skeleton. Because about 300,000 young Russian men were involved in the Chernobyl NPP cleanup operation, the resulting medical problem is of great social importance. Neither effective preventive measures not treatment is practicable without the basic etiological factors of osteoporosis in the young adult cleaners. Modern methods make it possible to perform precise studies of endocrine and immune status, to assess of water-electrolyte, mineral, and trace element metabolism, and estimate retrospectively the levels of intoxication from Pb and Cd. Unfortunately, during the past 16 years, neither national nor international sources have been found to finance such studies

  13. High energy density in matter produced by heavy ion beams

    International Nuclear Information System (INIS)

    1989-07-01

    This Annual Report summarizes research activities carried out in 1988 in the framework of the government-funded program 'High Energy Density in Matter produced by Heavy Ion Beams'. It addresses fundamental problems of the generation of heavy ion beams and the investigation of hot dense plasmas produced by these beams. Its initial motivation and its long-term goal is the feasibility of inertial confinement fusion by intense heavy ion beams. Two outstanding events deserve to be mentioned explicity, the Heavy Ion Inertial Fusion Conference held in Darmstadt and organized by GSI end of June and the first heavy ion beam injected into the new SIS facility in November. The former event attracted more than hundred scientists for three days to the 4th Conference in this field. This symposium showed the impressive progress since the last conference in Washington two years ago. In particular the first beams in MBE-4 at LBL and results of beam plasma interaction experiments at GSI open new directions for future investigations. The ideas for non-Lionvillean injection into storage rings presented by Carlo Rubbia will bring the discussion of driver scenarios into a new stage. The latter event is a milestone for both machine and target experiments. It characterizes the beginning of the commissioning phase for the new SIS/ESR facility which will be ready for experiments at the end of this year. The commissioning of SIS is on schedule and first experiments can start at the beginning of 1990. A status report of the accelerator project is included. Theoretical activities were continued as in previous years, many of them providing guide lines for future experiments, in particular for the radiation transport aspects and for beam-plasma interaction. (orig.)

  14. Monitoring of dose rates and radiation flux density in working rooms

    International Nuclear Information System (INIS)

    Krajtor, S.N.

    1980-01-01

    The problems of determining the neutron field characteristics (dose equivalent rate and flux density) in relation to the environmental monitoring by radiation protection services. The measurement devices used for measuring dose equivalent rate and neutron flux density RUS-U8 multi-purpose scintillation radiometer and RUP-1 multi-purpose transportable radiometer as well as measurement technique are described. Recommendations are given for checking measuring devices calibration, registering measurement results [ru

  15. Compact high-power terahertz radiation source

    Directory of Open Access Journals (Sweden)

    G. A. Krafft

    2004-06-01

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

  16. High density operation on the HT-7 superconducting tokamak

    International Nuclear Information System (INIS)

    Xiang Gao

    2000-01-01

    The structure of the operation region has been studied in the HT-7 superconducting tokamak, and progress on the extension of the HT-7 ohmic discharge operation region is reported. A density corresponding to 1.2 times the Greenwald limit was achieved by RF boronization. The density limit appears to be connected to the impurity content and the edge parameters, so the best results are obtained with very clean plasmas and peaked electron density profiles. The peaking factors of electron density profiles for different current and line averaged densities were observed. The density behaviour and the fuelling efficiency for gas puffing (20-30%), pellet injection (70-80%) and molecular beam injection (40-50%) were studied. The core crash sawteeth and MHD behaviour, which were induced by an injected pellet, were observed and the events correlated with the change of current profile and reversed magnetic shear. The MARFE phenomena on HT-7 are summarized. The best correlation has been found between the total input ohmic power and the product of the edge line averaged density and Z eff . HT-7 could be easily operated in the high density region MARFE-free using RF boronization. (author)

  17. Operation and control of high density tokamak reactors

    International Nuclear Information System (INIS)

    Attenberger, S.E.; McAlees, D.G.

    1976-01-01

    The incentive for high density operation of a tokamak reactor was discussed. It is found that high density permits ignition in a relatively small, moderately elongated plasma with a moderate magnetic field strength. Under these conditions, neutron wall loadings approximately 4 MW/m 2 must be tolerated. The sensitivity analysis with respect to impurity effects shows that impurity control will most likely be necessary to achieve the desired plasma conditions. The charge exchange sputtered impurities are found to have an important effect so that maintaining a low neutral density in the plasma is critical. If it is assumed that neutral beams will be used to heat the plasma to ignition, high energy injection is required (approximately 250 keV) when heating is accompished at full density. A scenario is outlined where the ignition temperature is established at low density and then the fueling rate is increased to attain ignition. This approach may permit beams with energies being developed for use in TFTR to be successfully used to heat a high density device of the type described here to ignition

  18. Thulium heat source for high-endurance and high-energy density power systems

    International Nuclear Information System (INIS)

    Walter, C.E.; Kammeraad, J.E.; Van Konynenburg, R.; VanSant, J.H.

    1991-05-01

    We are studying the performance characteristics of radioisotope heat source designs for high-endurance and high-energy-density power systems that use thulium-170. Heat sources in the power range of 5--50 kW th coupled with a power conversion efficiency of ∼30%, can easily satisfy current missions for autonomous underwater vehicles. New naval missions will be possible because thulium isotope power systems have a factor of one-to-two hundred higher endurance and energy density than chemical and electrochemical systems. Thulium-170 also has several other attractive features, including the fact that it decays to stable ytterbium-170 with a half-life of four months. For terrestrial applications, refueling on that time scale should be acceptable in view of the advantage of its benign decay. The heat source designs we are studying account for the requirements of isotope production, shielding, and integration with power conversion components. These requirements are driven by environmental and safety considerations. Thulium is present in the form of thin refractory thulia disks that allow power conversion at high peak temperature. We give estimates of power system state points, performance, mass, and volume characteristics. Monte Carlo radiation analysis provides a detailed assessment of shield requirements and heat transfer under normal and distressed conditions is also considered. 11 refs., 7 figs., 4 tabs

  19. Physics of radiation-driven islands near the tokamak density limit

    International Nuclear Information System (INIS)

    Gates, D.A.; Delgado-Aparicio, L.; White, R.B.

    2013-01-01

    In previous work (Gates and Delgado-Aparicio 2012 Phys. Rev. Lett. 108 165004), the onset criterion for radiation-driven islands (Rebut et al 1985 Proc. 10th Int. Conf. on Plasma Physics and Controlled Nuclear Fusion Research 1984 (London, UK, 1984) vol 2 (Vienna: IAEA) p 197) in combination with a simple cylindrical model of tokamak current channel behaviour was shown to be consistent with the empirical scaling of the tokamak density limit (Greenwald et al 1988 Nucl. Fusion 28 2199). A number of the unexplained phenomena at the density limit are consistent with this novel physics mechanism. In this work, a more formal theoretical underpinning, consistent with cylindrical tearing mode theory, is developed for the onset criteria of these modes. The appropriate derivation of the radiation-driven addition to the modified Rutherford equation (MRE) is discussed. Additionally, the ordering of the terms in the MRE is examined in a regime near the density limit. It is hoped that, given the apparent success of this simple model in explaining the observed global scalings, it will lead to a more comprehensive analysis of the possibility that radiation-driven islands are the physics mechanism responsible for the density limit. In particular, with modern diagnostic capabilities detailed measurements of current densities, electron densities and impurity concentrations at rational surfaces should be possible, enabling verification of the concepts described above. (paper)

  20. High volumetric power density, non-enzymatic, glucose fuel cells.

    Science.gov (United States)

    Oncescu, Vlad; Erickson, David

    2013-01-01

    The development of new implantable medical devices has been limited in the past by slow advances in lithium battery technology. Non-enzymatic glucose fuel cells are promising replacement candidates for lithium batteries because of good long-term stability and adequate power density. The devices developed to date however use an "oxygen depletion design" whereby the electrodes are stacked on top of each other leading to low volumetric power density and complicated fabrication protocols. Here we have developed a novel single-layer fuel cell with good performance (2 μW cm⁻²) and stability that can be integrated directly as a coating layer on large implantable devices, or stacked to obtain a high volumetric power density (over 16 μW cm⁻³). This represents the first demonstration of a low volume non-enzymatic fuel cell stack with high power density, greatly increasing the range of applications for non-enzymatic glucose fuel cells.

  1. Noise reduction in muon tomography for detecting high density objects

    International Nuclear Information System (INIS)

    Benettoni, M; Checchia, P; Cossutta, L; Furlan, M; Gonella, F; Pegoraro, M; Garola, A Rigoni; Ronchese, P; Vanini, S; Viesti, G; Bettella, G; Bonomi, G; Donzella, A; Subieta, M; Zenoni, A; Calvagno, G; Cortelazzo, G; Zanuttigh, P; Calvini, P; Squarcia, S

    2013-01-01

    The muon tomography technique, based on multiple Coulomb scattering of cosmic ray muons, has been proposed as a tool to detect the presence of high density objects inside closed volumes. In this paper a new and innovative method is presented to handle the density fluctuations (noise) of reconstructed images, a well known problem of this technique. The effectiveness of our method is evaluated using experimental data obtained with a muon tomography prototype located at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN). The results reported in this paper, obtained with real cosmic ray data, show that with appropriate image filtering and muon momentum classification, the muon tomography technique can detect high density materials, such as lead, albeit surrounded by light or medium density material, in short times. A comparison with algorithms published in literature is also presented

  2. Numerical simulation of SU(2)c high density state

    International Nuclear Information System (INIS)

    Muroya, Shin; Nakamura, Atsushi; Nonaka, Chiho

    2003-01-01

    We report a study of the high baryon number density system with use of the two-color lattice QCD with Wilson fermions[1]. First we investigate thermodynamical quantities such as the Polyakov line, gluon energy density, and baryon number density in the (κ, μ) plane, where κ and μ are the hopping parameter and chemical potential, respectively. Then we calculate propagators of meson (q-barΓq) and baryon (qΓq) states in addition to the potential between quark lines. (author)

  3. Low-frequency oscillations at high density in JFT-2

    International Nuclear Information System (INIS)

    Maeno, Masaki; Katagiri, Masaki; Suzuki, Norio; Fujisawa, Noboru

    1977-12-01

    Low-frequency oscillations in a plasma were measured with magnetic probes and Si surface-barrier detectors, and behaviour of the high density plasmas was studied. The plasma current profile in the phase of decreasing density after the interruption of gas input is more peaked than during gas input. The introduction of hydrogen during a discharge results in a reduction of the impurities flux. The increase of density by fast gas input is limited with a negative voltage spike. Immediately before a negative voltage spike, oscillations of m=1,2 grow, leading to the spike. (auth.)

  4. A new quasi-stationary, very high density plasma regime on the W7-AS stellarator

    International Nuclear Information System (INIS)

    Jaenicke, R; Baeumel, S; Baldzuhn, J; Brakel, R; Burhenn, R; Ehmler, H; Endler, M; Erckmann, V; Feng, Y; Gadelmeier, F; Geiger, J; Giannone, L; Grigull, P; Hartfuss, H J; Hartmann, D; Hildebrandt, D; Hirsch, M; Holzhauer, E; Kick, M; Kisslinger, J; Klinger, T; Klose, S; Knauer, J; Koenig, R; Kuehner, G; Laqua, H; Maassberg, H; McCormick, K; Narayanan, R; Niedermeyer, H; Pasch, E; Ruhs, N; Rust, N; Saffert, J; Sardei, F; Schneider, F; Schubert, M; Speth, E; Wagner, F; Weller, A; Wenzel, U; Werner, A; Wuersching, E

    2002-01-01

    Stellarators have the intrinsic property of steady state operation. However, on present-day stellarators the pulse length is usually not only limited due to technical reasons, but also by physical problems. Lack of density control and a subsequent radiation collapse terminate the discharges quite often at high densities. To improve the control of the plasma-wall interaction, the island divertor concept was developed for optimized stellarators. To test this divertor concept on W7-AS, all limiters were removed and replaced by ten divertor modules. In subsequent divertor experiments a promising new plasma operational regime has been discovered which is termed 'high density H-mode' (HDH-mode). During the transition into that regime a clear reduction of ELM-like events and turbulent fluctuations is observed. The HDH-mode combines good energy confinement with very low impurity confinement resulting in low core radiation, but high edge-localized radiation. Consequently, stationary discharges at densities of typically 2x10 20 m -3 can be performed within the accessible pulse length of about 1 s. At densities above 3x10 20 m -3 a controlled transition from attached to partially detached plasmas is observed. The still edge-localized radiation reaches 90% of the heating power so that the power load onto the divertor target plates is further reduced. At a lower toroidal field of 0.9 T average β-values could be raised from earlier 2% to more than 3% in magnetic field configurations with rather smooth flux surfaces at the plasma boundary. The recently obtained results render excellent prospects for W7-X, the larger superconducting successor experiment of W7-AS

  5. Terrestrial gamma radiation baseline mapping using ultra low density sampling methods

    International Nuclear Information System (INIS)

    Kleinschmidt, R.; Watson, D.

    2016-01-01

    Baseline terrestrial gamma radiation maps are indispensable for providing basic reference information that may be used in assessing the impact of a radiation related incident, performing epidemiological studies, remediating land contaminated with radioactive materials, assessment of land use applications and resource prospectivity. For a large land mass, such as Queensland, Australia (over 1.7 million km 2 ), it is prohibitively expensive and practically difficult to undertake detailed in-situ radiometric surveys of this scale. It is proposed that an existing, ultra-low density sampling program already undertaken for the purpose of a nationwide soil survey project be utilised to develop a baseline terrestrial gamma radiation map. Geoelement data derived from the National Geochemistry Survey of Australia (NGSA) was used to construct a baseline terrestrial gamma air kerma rate map, delineated by major drainage catchments, for Queensland. Three drainage catchments (sampled at the catchment outlet) spanning low, medium and high radioelement concentrations were selected for validation of the methodology using radiometric techniques including in-situ measurements and soil sampling for high resolution gamma spectrometry, and comparative non-radiometric analysis. A Queensland mean terrestrial air kerma rate, as calculated from the NGSA outlet sediment uranium, thorium and potassium concentrations, of 49 ± 69 nGy h −1 (n = 311, 3σ 99% confidence level) is proposed as being suitable for use as a generic terrestrial air kerma rate background range. Validation results indicate that catchment outlet measurements are representative of the range of results obtained across the catchment and that the NGSA geoelement data is suitable for calculation and mapping of terrestrial air kerma rate. - Highlights: • A baseline terrestrial air kerma map of Queensland, Australia was developed using geochemical data from a major drainage catchment ultra-low density sampling program

  6. Structural analysis with high brilliance synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Hideo [Japan Atomic Energy Research Inst., Kamigori, Hyogo (Japan). Kansai Research Establishment

    1997-11-01

    The research subjects in diffraction and scattering of materials with high brilliance synchrotron radiation such as SPring-8 (Super Photon ring 8 GeV) are summarized. The SPring-8 project is going well and 10 public beamlines will be opened for all users in October, 1997. Three JAERI beamlines are also under construction for researches of heavy element science, physical and structural properties under extreme conditions such as high temperature and high pressure. (author)

  7. Density-dependent squeezing of excitons in highly excited semiconductors

    International Nuclear Information System (INIS)

    Nguyen Hong Quang.

    1995-07-01

    The time evolution from coherent states to squeezed states of high density excitons is studied theoretically based on the boson formalism and within the Random Phase Approximation. Both the mutual interaction between excitons and the anharmonic exciton-photon interaction due to phase-space filling of excitons are taken into account. It is shown that the exciton squeezing depends strongly on the exciton density in semiconductors and becomes smaller with increasing the latter. (author). 16 refs, 2 figs

  8. High energy density capacitors fabricated by thin film technology

    International Nuclear Information System (INIS)

    Barbee, T W; Johnson, G W; Wagner, A V.

    1999-01-01

    Low energy density in conventional capacitors severely limits efforts to miniaturize power electronics and imposes design limitations on electronics in general. We have successfully applied physical vapor deposition technology to greatly increase capacitor energy density. The high dielectric breakdown strength we have achieved in alumina thin films allows high energy density to be achieved with this moderately low dielectric constant material. The small temperature dependence of the dielectric constant, and the high reliability, high resistivity, and low dielectric loss of Al 2 O 3 , make it even more appealing. We have constructed single dielectric layer thin film capacitors and shown that they can be stacked to form multilayered structures with no loss in yield for a given capacitance. Control of film growth morphology is critical for achieving the smooth, high quality interfaces between metal and dielectric necessary for device operation at high electric fields. Most importantly, high rate deposition with extremely low particle generation is essential for achieving high energy storage at a reasonable cost. This has been achieved by reactive magnetron sputtering in which the reaction to form the dielectric oxide has been confined to the deposition surface. By this technique we have achieved a yield of over 50% for 1 cm 2 devices with an energy density of 14 J per cubic centimeter of Al 2 O 3 dielectric material in 1.2 kV, 4 nF devices. By further reducing defect density and increasing the dielectric constant of the material, we will be able to increase capacitance and construct high energy density devices to meet the requirements of applications in power electronics

  9. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

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

  10. Interferometric measurements of plasma density in high-β plasmas

    International Nuclear Information System (INIS)

    Quinn, W.E.

    1977-01-01

    The coupled-cavity laser interferometer technique is particularly applicable to the measurement of pulsed plasma densities. This technique is based on the fact that if a small fraction of a gas laser's output radiation is reflected into the laser with an external mirror, the intensity of the laser output is modulated. These amplitude or intensity modulations are produced by changes in the laser gain. A rotating corner mirror or an oscillating mirror can be used to produce a continuous feedback modulation of the interferometer which produces a continuous background fringe pattern. The presence of plasma in the outer cavity causes an additional change which results in a phase shift of the regular period of the background fringe pattern. The integral of the plasma density along the line of sight can be evaluated by comparison of the time history of the fringes obtained with and without plasma

  11. Emulsion polymerization with high energy radiation

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  12. Density measurement by means of once scattered gamma radiation the ETG probe, principles and equipment

    International Nuclear Information System (INIS)

    Joergensen, J.L.; Oelgaard, P.L.; Berg, F.

    1987-01-01

    The Department of Electrophysics, the Technical University of Denmark, and the Danish National Road Laboratory have together developed a new patent claimed device for measurements of the in situ density of materials. This report describes the principles of the system and some experimental results. The system is based on the once scattered gamma radiation. In a totally non-destructive and fast way it is possible to measure the density of up to 25 cm thick layers. Furthermore, an estimate of the density variation through the layer may be obtained. Thus the gauge represents a new generation of equipment for e.g. compaction control of road constructions. (author)

  13. Broadband infrared photoluminescence in silicon nanowires with high density stacking faults.

    Science.gov (United States)

    Li, Yang; Liu, Zhihong; Lu, Xiaoxiang; Su, Zhihua; Wang, Yanan; Liu, Rui; Wang, Dunwei; Jian, Jie; Lee, Joon Hwan; Wang, Haiyan; Yu, Qingkai; Bao, Jiming

    2015-02-07

    Making silicon an efficient light-emitting material is an important goal of silicon photonics. Here we report the observation of broadband sub-bandgap photoluminescence in silicon nanowires with a high density of stacking faults. The photoluminescence becomes stronger and exhibits a blue shift under higher laser powers. The super-linear dependence on excitation intensity indicates a strong competition between radiative and defect-related non-radiative channels, and the spectral blue shift is ascribed to the band filling effect in the heterostructures of wurtzite silicon and cubic silicon created by stacking faults.

  14. Morphodynamics of supercritical high-density turbidity currents

    NARCIS (Netherlands)

    Cartigny, M.

    2012-01-01

    Seafloor and outcrop observations combined with numerical and physical experiments show that turbidity currents are likely 1) to be in a supercritical flow state and 2) to carry high sediment concentrations (being of high-density). The thesis starts with an experimental study of bedforms

  15. High Channel Count, High Density Microphone Arrays for Wind Tunnel Environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Interdisciplinary Consulting Corporation (IC2) proposes the development of high channel count, high density, reduced cost per channel, directional microphone...

  16. The use of high-density concretes in radiotherapy treatment room design

    International Nuclear Information System (INIS)

    Facure, A.; Silva, A.X.

    2007-01-01

    With the modernization of radiotherapic centers, medical linear accelerators are largely replacing 60 Co teletherapy units. In many cases, the same vault housing the 60 Co teletherapy unit is reused for the linear accelerator and, when space is at a premium, high-density concrete (3.0-5.0 g/cm 3 ) is employed to provide shielding against the primary, scatter and leakage radiation. This work presents a study based on Monte Carlo simulations of transmission of some clinical photon spectra (of 4-10 MV accelerators) through some types of high-density concretes, normally used in the construction of radiotherapy bunkers. From the simulations, the initial and subsequent tenth-value layers (TVL) for these materials, taking into account realistic clinical photon spectra, are presented, for primary radiation

  17. High pressure and synchrotron radiation satellite workshop

    Energy Technology Data Exchange (ETDEWEB)

    Bass, J.; Guignot, N.; Morard, G.; Mezouar, M.; Andrault, D.; Bolfan-Casanova, N.; Sturhahn, W.; Daniel, I.; Reynard, B.; Simionovici, A.; Sanchez Valle, C.; Martinez, I.; Kantor, I.; Dubrovinsky, I.; Mccammon, C.; Dubrovinskaia, N.; Kurnosiv, A.; Kuznetsov, A.; Goncharenko, I.; Loubeyre, P.; Desgreniers, S.; Weck, G.; Yoo, C.S.; Iota, V.; Park, J.; Cynn, H.; Gorelli, F.; Toulemonde, P.; Machon, D.; Merlen, A.; San Miguel, A.; Amboage, M.; Aquilanti, G.; Mathon, O.; Pascarelli, S.; Itie, J.P.; Mcmillan, P.F.; Trapananti, A.; Di Cicco, A.; Panfilis, S. de; Filipponi, A.; Kreisel, J.; Bouvier, P.; Dkhil, B.; Chaabane, B.; Rosner, H.; Koudela, D.; Schwarz, U.; Handestein, A.; Hanfland, M.; Opahle, I.; Koepernik, K.; Kuzmin, M.; Mueller, K.H.; Mydosh, J.; Richter, M.; Hejny, C.; Falconi, S.; Lundegaard, L.F.; Mcmahon, M.I; Loa, I.; Syassen, K.; Wang, X.; Roth, H.; Lorenz, T.; Farber Daniel, I.; Antonangeli Daniele, I.; Krisch, M.; Badro, J.; Fiquet, G.; Occelli, F.; Mao, W.L.; Mao, H.K.; Eng, P.; Kao, C.C.; Shu, J.F.; Hemley, R.J.; Tse, J.S.; Yao, Y.; Deen, P.P.; Paolasini, I.; Braithwaite, D.; Kernavanois, N.; Lapertot, G.; Rupprecht, K.; Leupold, O.; Ponkratz, U.; Wortmann, G.; Beraud, A.; Krisch, M.; Farber, D.; Antonangeli, D.; Aracne, C.; Zarestky, J.L.; Mcqueeney, R.; Mathon, O.; Baudelet, F.; Decremps, F.; Itie, J.P.; Nataf, I.; Pascarelli, S.; Polian, A

    2006-07-01

    The workshop is dedicated to recent advances on science at high pressure at third generation synchrotron sources. A variety of experiments using synchrotron radiation techniques including X-ray diffraction, EXAFS (extended X-ray absorption fine structure), inelastic X-ray scattering, Compton scattering and Moessbauer spectroscopy of crystalline, liquid or amorphous samples, are reported. This document gathers the abstracts of the presentations.

  18. High pressure and synchrotron radiation satellite workshop

    International Nuclear Information System (INIS)

    Bass, J.; Guignot, N.; Morard, G.; Mezouar, M.; Andrault, D.; Bolfan-Casanova, N.; Sturhahn, W.; Daniel, I.; Reynard, B.; Simionovici, A.; Sanchez Valle, C.; Martinez, I.; Kantor, I.; Dubrovinsky, I.; Mccammon, C.; Dubrovinskaia, N.; Kurnosiv, A.; Kuznetsov, A.; Goncharenko, I.; Loubeyre, P.; Desgreniers, S.; Weck, G.; Yoo, C.S.; Iota, V.; Park, J.; Cynn, H.; Gorelli, F.; Toulemonde, P.; Machon, D.; Merlen, A.; San Miguel, A.; Amboage, M.; Aquilanti, G.; Mathon, O.; Pascarelli, S.; Itie, J.P.; Mcmillan, P.F.; Trapananti, A.; Di Cicco, A.; Panfilis, S. de; Filipponi, A.; Kreisel, J.; Bouvier, P.; Dkhil, B.; Chaabane, B.; Rosner, H.; Koudela, D.; Schwarz, U.; Handestein, A.; Hanfland, M.; Opahle, I.; Koepernik, K.; Kuzmin, M.; Mueller, K.H.; Mydosh, J.; Richter, M.; Hejny, C.; Falconi, S.; Lundegaard, L.F.; Mcmahon, M.I; Loa, I.; Syassen, K.; Wang, X.; Roth, H.; Lorenz, T.; Farber Daniel, I.; Antonangeli Daniele, I.; Krisch, M.; Badro, J.; Fiquet, G.; Occelli, F.; Mao, W.L.; Mao, H.K.; Eng, P.; Kao, C.C.; Shu, J.F.; Hemley, R.J.; Tse, J.S.; Yao, Y.; Deen, P.P.; Paolasini, I.; Braithwaite, D.; Kernavanois, N.; Lapertot, G.; Rupprecht, K.; Leupold, O.; Ponkratz, U.; Wortmann, G.; Beraud, A.; Krisch, M.; Farber, D.; Antonangeli, D.; Aracne, C.; Zarestky, J.L.; Mcqueeney, R.; Mathon, O.; Baudelet, F.; Decremps, F.; Itie, J.P.; Nataf, I.; Pascarelli, S.; Polian, A.

    2006-01-01

    The workshop is dedicated to recent advances on science at high pressure at third generation synchrotron sources. A variety of experiments using synchrotron radiation techniques including X-ray diffraction, EXAFS (extended X-ray absorption fine structure), inelastic X-ray scattering, Compton scattering and Moessbauer spectroscopy of crystalline, liquid or amorphous samples, are reported. This document gathers the abstracts of the presentations

  19. High energy density propulsion systems and small engine dynamometer

    Science.gov (United States)

    Hays, Thomas

    2009-07-01

    Scope and Method of Study. This study investigates all possible methods of powering small unmanned vehicles, provides reasoning for the propulsion system down select, and covers in detail the design and production of a dynamometer to confirm theoretical energy density calculations for small engines. Initial energy density calculations are based upon manufacturer data, pressure vessel theory, and ideal thermodynamic cycle efficiencies. Engine tests are conducted with a braking type dynamometer for constant load energy density tests, and show true energy densities in excess of 1400 WH/lb of fuel. Findings and Conclusions. Theory predicts lithium polymer, the present unmanned system energy storage device of choice, to have much lower energy densities than other conversion energy sources. Small engines designed for efficiency, instead of maximum power, would provide the most advantageous method for powering small unmanned vehicles because these engines have widely variable power output, loss of mass during flight, and generate rotational power directly. Theoretical predictions for the energy density of small engines has been verified through testing. Tested values up to 1400 WH/lb can be seen under proper operating conditions. The implementation of such a high energy density system will require a significant amount of follow-on design work to enable the engines to tolerate the higher temperatures of lean operation. Suggestions are proposed to enable a reliable, small-engine propulsion system in future work. Performance calculations show that a mature system is capable of month long flight times, and unrefueled circumnavigation of the globe.

  20. Are radiative corrections to the Mikheyev-Smirnov-Wolfenstein formula affected by finite temperature and density?

    International Nuclear Information System (INIS)

    Horvat, R.

    1993-01-01

    One-loop photonic corrections to the electron-neutrino (ν e ) charged-current medium induced self-energy are examined using finite temperature field theory. It is shown that irrespective of computing radiative corrections at finite temperature and density, there are no O(α) corrections to the charged-current contribution of the ν e 's dispersion relation

  1. Interaction of laser radiation with a low-density structured absorber

    Czech Academy of Sciences Publication Activity Database

    Rozanov, V. B.; Barishpol’tsev, D.V.; Vergunova, G.A.; Demchenko, N. N.; Ivanov, E.M.; Aristova, E.N.; Zmitrenko, N.V.; Limpouch, I.; Ullschmied, Jiří

    2016-01-01

    Roč. 122, č. 2 (2016), s. 256-276 ISSN 1063-7761 Institutional support: RVO:61389021 Keywords : laser radiation interaction * laser with low-density Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.196, year: 2016

  2. Interaction of a high-power laser pulse with supercritical-density porous materials

    International Nuclear Information System (INIS)

    Gus'kov, Sergei Yu; Rozanov, Vladislav B; Caruso, A; Strangio, C

    2000-01-01

    The properties of a nonequilibrium plasma produced by high-power laser pulses with intensities I L ∼ 10 14 -10 15 W cm -2 irradiating plane targets made of a porous material are investigated. The mean density of matter in targets was substantially higher than the critical plasma density corresponding to a plasma resonance. The density of porous material was ρ a ∼ 1 - 20 mg cm -3 , whereas the critical density at the wavelength of incident radiation was ρ cr ∼ 3 mg cm -3 . An anomalously high absorption (no less than 80%) of laser radiation inside a target was observed. Within the first 3 - 4 ns of interaction, the plasma flow through the irradiated target surface in the direction opposite of the direction of the laser beam was noticeably suppressed. Only about 5% of absorbed laser energy was transformed into the energy of particles in this flow during the laser pulse. Absorbed energy was stored as the internal plasma energy at this stage (the greenhouse effect). Then, this energy was transformed, similar to a strong explosion, into the energy of a powerful hydrodynamic flow of matter surrounding the absorption region. The specific features of the formation and evolution of a nonequilibrium laser-produced plasma in porous media are theoretically analysed. This study allows the results of experiments to be explained. In particular, we investigated absorption of laser radiation in the bulk of a target, volume evaporation of porous material, the expansion of a laser-produced plasma inside the pores, stochastic collisions of plasma flows, and hydrothermal energy dissipation. These processes give rise to long-lived oscillations of plasma density and lead to the formation of an internal region where laser radiation is absorbed. (invited paper)

  3. High energy-density physics: From nuclear testing to the superlasers

    International Nuclear Information System (INIS)

    Teller, E.; Campbell, E.M.; Holmes, N.C.; Libby, S.B.; Remington, B.A.

    1995-01-01

    The authors describe the role for the next-generation ''superlasers'' in the study of matter under extremely high energy density conditions, in comparison to previous uses of nuclear explosives for this purpose. As examples, the authors focus on three important areas of physics that have unresolved issues which must be addressed by experiment: equations of state, turbulent hydrodynamics, and the transport of radiation. They describe the advantages the large lasers will have in a comprehensive experimental program

  4. High energy-density physics: From nuclear testing to the superlasers

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, E.M.; Holmes, N.C.; Libby, S.B.; Remington, B.A.; Teller, E.

    1995-10-20

    We describe the role for the next-generation ``superlasers`` in the study of matter under extremely high energy density conditions, in comparison to previous uses of nuclear explosives for this purpose. As examples, we focus on three important areas of physics that have unresolved issues which must be addressed by experiment: Equations of state, hydrodynamic mixing, and the transport of radiation. We will describe the advantages the large lasers will have in a comprehensive experimental program.

  5. High energy-density physics: From nuclear testing to the superlasers

    International Nuclear Information System (INIS)

    Campbell, E.M.; Holmes, N.C.; Libby, S.B.; Remington, B.A.; Teller, E.

    1995-01-01

    We describe the role for the next-generation ''superlasers'' in the study of matter under extremely high energy density conditions, in comparison to previous uses of nuclear explosives for this purpose. As examples, we focus on three important areas of physics that have unresolved issues which must be addressed by experiment: Equations of state, hydrodynamic mixing, and the transport of radiation. We will describe the advantages the large lasers will have in a comprehensive experimental program

  6. High energy-density physics: From nuclear testing to the superlasers

    Energy Technology Data Exchange (ETDEWEB)

    Teller, E.; Campbell, E.M.; Holmes, N.C.; Libby, S.B.; Remington, B.A.

    1995-08-14

    The authors describe the role for the next-generation ``superlasers`` in the study of matter under extremely high energy density conditions, in comparison to previous uses of nuclear explosives for this purpose. As examples, the authors focus on three important areas of physics that have unresolved issues which must be addressed by experiment: equations of state, turbulent hydrodynamics, and the transport of radiation. They describe the advantages the large lasers will have in a comprehensive experimental program.

  7. Interplay of charge density wave and spin density wave in high-T{sub c} superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, B. [Government Science College, Malkangiri 764 048 (India)], E-mail: brunda@iopb.res.in; Raj, B.K. [B.J.B. College, Bhubaneswar 751 014 (India); Rout, G.C. [Condensed Matter Physics Group, P.G. Department of Applied Physics and Ballistics, F.M. University, Balasore 756 019 (India)], E-mail: gcr@iopb.res.in

    2008-12-01

    We present a mean-field theory theoretical model study for the coexistence of the two strongly interacting charge density wave (CDW) and spin density wave (SDW) for high-T{sub c} cuprates in the underdoped region before the onset of the superconductivity in the system. The analytic expressions for the temperature dependence of the CDW and SDW order parameters are derived and solved self-consistently. Their interplay is studied by varying their respective coupling constants. It is observed that in the interplay region both the gap parameters exhibit very strong dependence of their gap values for the coupling constants. Further, the electronic density of states (DOS) for the conduction electrons, which represents the scanning tunneling data, show two gap parameters in the interplay region from these experimental data. Our model can help to determine separately the CDW and SDW parameters.

  8. Interplay of charge density wave and spin density wave in high-Tc superconductors

    International Nuclear Information System (INIS)

    Pradhan, B.; Raj, B.K.; Rout, G.C.

    2008-01-01

    We present a mean-field theory theoretical model study for the coexistence of the two strongly interacting charge density wave (CDW) and spin density wave (SDW) for high-T c cuprates in the underdoped region before the onset of the superconductivity in the system. The analytic expressions for the temperature dependence of the CDW and SDW order parameters are derived and solved self-consistently. Their interplay is studied by varying their respective coupling constants. It is observed that in the interplay region both the gap parameters exhibit very strong dependence of their gap values for the coupling constants. Further, the electronic density of states (DOS) for the conduction electrons, which represents the scanning tunneling data, show two gap parameters in the interplay region from these experimental data. Our model can help to determine separately the CDW and SDW parameters

  9. High density regimes and beta limits in JET

    International Nuclear Information System (INIS)

    Smeulders, P.

    1990-01-01

    Results are first presented on the density limit in JET discharges with graphite (C), Be gettered graphite and Be limiters. There is a clear improvement in the case of Be limiters. The Be gettered phase showed no increase in the gas fueled density limit, except with Ion Cyclotron Resonance Heating (ICRH), but, the limit changed character. During MARFE-formation, any further increase in density was prevented, leading to a soft density limit. The soft density limit was a function of input power and impurity content with a week dependence on q. Helium and pellet fuelled discharges exceeded the gas-fuelled global density limits, but essentially had the same edge limit. In the second part, results are presented of high β operation in low-B Double-Null (DN) X-point configurations with Be-gettered carbon target plates. The Troyon limit was reached during H-mode discharges and toroidal β values of 5.5% were obtained. At high beta, the sawteeth were modified and characterised by very rapid heat-waves and fishbone-like pre- and post-cursors with strongly ballooning character. 17 refs., 5 figs

  10. High density data storage principle, technology, and materials

    CERN Document Server

    Zhu, Daoben

    2009-01-01

    The explosive increase in information and the miniaturization of electronic devices demand new recording technologies and materials that combine high density, fast response, long retention time and rewriting capability. As predicted, the current silicon-based computer circuits are reaching their physical limits. Further miniaturization of the electronic components and increase in data storage density are vital for the next generation of IT equipment such as ultra high-speed mobile computing, communication devices and sophisticated sensors. This original book presents a comprehensive introduction to the significant research achievements on high-density data storage from the aspects of recording mechanisms, materials and fabrication technologies, which are promising for overcoming the physical limits of current data storage systems. The book serves as an useful guide for the development of optimized materials, technologies and device structures for future information storage, and will lead readers to the fascin...

  11. Progress in high-dose radiation dosimetry

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  12. Changing perceptions of hunger on a high nutrient density diet

    Directory of Open Access Journals (Sweden)

    Glaser Dale

    2010-11-01

    Full Text Available Abstract Background People overeat because their hunger directs them to consume more calories than they require. The purpose of this study was to analyze the changes in experience and perception of hunger before and after participants shifted from their previous usual diet to a high nutrient density diet. Methods This was a descriptive study conducted with 768 participants primarily living in the United States who had changed their dietary habits from a low micronutrient to a high micronutrient diet. Participants completed a survey rating various dimensions of hunger (physical symptoms, emotional symptoms, and location when on their previous usual diet versus the high micronutrient density diet. Statistical analysis was conducted using non-parametric tests. Results Highly significant differences were found between the two diets in relation to all physical and emotional symptoms as well as the location of hunger. Hunger was not an unpleasant experience while on the high nutrient density diet, was well tolerated and occurred with less frequency even when meals were skipped. Nearly 80% of respondents reported that their experience of hunger had changed since starting the high nutrient density diet, with 51% reporting a dramatic or complete change in their experience of hunger. Conclusions A high micronutrient density diet mitigates the unpleasant aspects of the experience of hunger even though it is lower in calories. Hunger is one of the major impediments to successful weight loss. Our findings suggest that it is not simply the caloric content, but more importantly, the micronutrient density of a diet that influences the experience of hunger. It appears that a high nutrient density diet, after an initial phase of adjustment during which a person experiences "toxic hunger" due to withdrawal from pro-inflammatory foods, can result in a sustainable eating pattern that leads to weight loss and improved health. A high nutrient density diet provides

  13. Ultra Secure High Reliability Wireless Radiation Monitor

    International Nuclear Information System (INIS)

    Cordaro, J.; Shull, D.; Farrar, M.; Reeves, G.

    2011-01-01

    Radiation monitoring in nuclear facilities is essential to safe operation of the equipment as well as protecting personnel. In specific, typical air monitoring of radioactive gases or particulate involves complex systems of valves, pumps, piping and electronics. The challenge is to measure a representative sample in areas that are radioactively contaminated. Running cables and piping to these locations is very expensive due to the containment requirements. Penetration into and out of an airborne or containment area is complex and costly. The process rooms are built with thick rebar-enforced concrete walls with glove box containment chambers inside. Figure 1 shows high temperature radiation resistance cabling entering the top of a typical glove box. In some case, the entire processing area must be contained in a 'hot cell' where the only access into the chamber is via manipulators. An example is shown in Figure 2. A short range wireless network provides an ideal communication link for transmitting the data from the radiation sensor to a 'clean area', or area absent of any radiation fields or radioactive contamination. Radiation monitoring systems that protect personnel and equipment must meet stringent codes and standards due to the consequences of failure. At first glance a wired system would seem more desirable. Concerns with wireless communication include latency, jamming, spoofing, man in the middle attacks, and hacking. The Department of Energy's Savannah River National Laboratory (SRNL) has developed a prototype wireless radiation air monitoring system that address many of the concerns with wireless and allows quick deployment in radiation and contamination areas. It is stand alone and only requires a standard 120 VAC, 60 Hz power source. It is designed to be mounted or portable. The wireless link uses a National Security Agency (NSA) Suite B compliant wireless network from Fortress Technologies that is considered robust enough to be used for classified data

  14. ULTRA SECURE HIGH RELIABILITY WIRELESS RADIATION MONITOR

    Energy Technology Data Exchange (ETDEWEB)

    Cordaro, J.; Shull, D.; Farrar, M.; Reeves, G.

    2011-08-03

    Radiation monitoring in nuclear facilities is essential to safe operation of the equipment as well as protecting personnel. In specific, typical air monitoring of radioactive gases or particulate involves complex systems of valves, pumps, piping and electronics. The challenge is to measure a representative sample in areas that are radioactively contaminated. Running cables and piping to these locations is very expensive due to the containment requirements. Penetration into and out of an airborne or containment area is complex and costly. The process rooms are built with thick rebar-enforced concrete walls with glove box containment chambers inside. Figure 1 shows high temperature radiation resistance cabling entering the top of a typical glove box. In some case, the entire processing area must be contained in a 'hot cell' where the only access into the chamber is via manipulators. An example is shown in Figure 2. A short range wireless network provides an ideal communication link for transmitting the data from the radiation sensor to a 'clean area', or area absent of any radiation fields or radioactive contamination. Radiation monitoring systems that protect personnel and equipment must meet stringent codes and standards due to the consequences of failure. At first glance a wired system would seem more desirable. Concerns with wireless communication include latency, jamming, spoofing, man in the middle attacks, and hacking. The Department of Energy's Savannah River National Laboratory (SRNL) has developed a prototype wireless radiation air monitoring system that address many of the concerns with wireless and allows quick deployment in radiation and contamination areas. It is stand alone and only requires a standard 120 VAC, 60 Hz power source. It is designed to be mounted or portable. The wireless link uses a National Security Agency (NSA) Suite B compliant wireless network from Fortress Technologies that is considered robust enough to be

  15. Semiconductor high-energy radiation scintillation detector

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  16. High power beam profile monitor with optical transition radiation

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  17. Possible new form of matter at high density

    International Nuclear Information System (INIS)

    Lee, T.D.

    1974-01-01

    As a preliminary to discussion of the possibility of new forms of matter at high density, questions relating to the vacuum and vacuum excitation are considered. A quasi-classical approach to the development of abnormal nuclear states is undertaken using a Fermi gas of nucleons of uniform density. Discontinuous transitions are considered in the sigma model (tree approximation) followed by brief consideration of higher order loop diagrams. Production and detection of abnormal nuclear states are discussed in the context of high energy heavy ion collisions. Remarks are made on motivation for such research. 8 figures

  18. High Density Interconnect Microstrip Patch Antenna for 5G Base Stations with Integrated Filtering Performance

    Directory of Open Access Journals (Sweden)

    Marco Salucci

    2018-04-01

    Full Text Available The elementary radiator of a planar array for next generation millimeter-wave (mm-wave 5G base stations is described. The antenna is designed for high density interconnect (HDI manufacturing for yielding a compact, densely-interconnected, and highly-integrable stacked structure. The layout of the single element is determined by directly optimizing key radiation features of the whole planar arrangement according to specific application-driven requirements. In addition, thanks to the exploitation of a spline-shaped modelling of the radiator, suitable performance in terms of impedance matching, realized gain, half-power beamwidth (HPBW, polarization purity, and inter-element isolation are achieved within the 28-GHz pass-band. Moreover, integrated out-of-band filtering capabilities are obtained in selected and wide non-contiguous stop-bands without additional circuitry.

  19. An adaptive crystal bender for high power synchrotron radiation beams

    International Nuclear Information System (INIS)

    Berman, L.E.; Hastings, J.B.

    1992-01-01

    Perfect crystal monochromators cannot diffract x-rays efficiently, nor transmit the high source brightness available at synchrotron radiation facilities, unless surface strains within the beam footprint are maintained within a few arcseconds. Insertion devices at existing synchrotron sources already produce x-ray power density levels that can induce surface slope errors of several arcseconds on silicon monochromator crystals at room temperature, no matter how well the crystal is cooled. The power density levels that will be produced by insertion devices at the third-generation sources will be as much as a factor of 100 higher still. One method of restoring ideal x-ray diffraction behavior, while coping with high power levels, involves adaptive compensation of the induced thermal strain field. The design and performance, using the X25 hybrid wiggler beam line at the National Synchrotron Light Source (NSLS), of a silicon crystal bender constructed for this purpose are described

  20. High-density polymorphisms analysis of 23 candidate genes for association with bone mineral density.

    Science.gov (United States)

    Giroux, Sylvie; Elfassihi, Latifa; Clément, Valérie; Bussières, Johanne; Bureau, Alexandre; Cole, David E C; Rousseau, François

    2010-11-01

    Osteoporosis is a bone disease characterized by low bone mineral density (BMD), a highly heritable and polygenic trait. Women are more prone than men to develop osteoporosis due to a lower peak bone mass and accelerated bone loss at menopause. Peak bone mass has been convincingly shown to be due to genetic factors with heritability up to 80%. Menopausal bone loss has been shown to have around 38% to 49% heritability depending on the site studied. To have more statistical power to detect small genetic effects we focused on premenopausal women. We studied 23 candidate genes, some involved in calcium and vitamin-D regulation and others because estrogens strongly induced their gene expression in mice where it was correlated with humerus trabecular bone density. High-density polymorphisms were selected to cover the entire gene variability and 231 polymorphisms were genotyped in a first sample of 709 premenopausal women. Positive associations were retested in a second, independent, sample of 673 premenopausal women. Ten polymorphisms remained associated with BMD in the combined samples and one was further associated in a large sample of postmenopausal women (1401 women). This associated polymorphism was located in the gene CSF3R (granulocyte colony stimulating factor receptor) that had never been associated with BMD before. The results reported in this study suggest a role for CSF3R in the determination of bone density in women. Copyright © 2010 Elsevier Inc. All rights reserved.

  1. Plasma Photonic Devices for High Energy Density Science

    International Nuclear Information System (INIS)

    Kodama, R.

    2005-01-01

    High power laser technologies are opening a variety of attractive fields of science and technology using high energy density plasmas such as plasma physics, laboratory astrophysics, material science, nuclear science including medical applications and laser fusion. The critical issues in the applications are attributed to the control of intense light and enormous density of charged particles including efficient generation of the particles such as MeV electrons and protons with a current density of TA/cm2. Now these application possibilities are limited only by the laser technology. These applications have been limited in the control of the high power laser technologies and their optics. However, if we have another device consisted of the 4th material, i.e. plasma, we will obtain a higher energy density condition and explore the application possibilities, which could be called high energy plasma device. One of the most attractive devices has been demonstrated in the fast ignition scheme of the laser fusion, which is cone-guiding of ultra-intense laser light in to high density regions1. This is one of the applications of the plasma device to control the ultra-intense laser light. The other role of the devices consisted of transient plasmas is control of enormous energy-density particles in a fashion analogous to light control with a conventional optical device. A plasma fibre (5?m/1mm), as one example of the devices, has guided and deflected the high-density MeV electrons generated by ultra-intense laser light 2. The electrons have been well collimated with either a lens-like plasma device or a fibre-like plasma, resulting in isochoric heating and creation of ultra-high pressures such as Giga bar with an order of 100J. Plasmas would be uniquely a device to easily control the higher energy density particles like a conventional optical device as well as the ultra-intense laser light, which could be called plasma photonic device. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  3. Edge density profiles in high-performance JET plasmas

    International Nuclear Information System (INIS)

    Summers, D.D.R.; Viaccoz, B.; Vince, J.

    1997-01-01

    Detailed electron density profiles of the scrape-off layer in high-performance JET plasmas (plasma current, I p nbi ∝17 MW) have been measured by means of a lithium beam diagnostic system featuring high spatial resolution [Kadota (1978)[. Measurements were taken over a period of several seconds, allowing examination of the evolution of the edge profile at a location upstream from the divertor target. The data clearly show the effects of the H-mode transition - an increase in density near the plasma separatrix and a reduction in density scrape-off length. The profiles obtained under various plasma conditions are compared firstly with data from other diagnostics, located elsewhere in the vessel, and also with the predictions of an 'onion-skin' model (DIVIMP), which used, as initial parameters, data from an array of probes located in the divertor target. (orig.)

  4. Novel nanostructured materials for high energy density supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, C.Z.; Zhang, X.G. [Nanjing Univ. of Aeronautics and Astronautics (China). College of Material Science and Engineering

    2010-07-01

    Researchers are currently examining methods of improving energy density while not sacrificing the high power density of supercapacitors. In this study, nanostructured materials assembled from nanometer-sized building blocks with mesoporosity were synthesized in order investigate diffusion time, kinetics, and capacitances. Petal-like cobalt hydroxide Co(OH){sub 2} mesocrystals, urchin-like Co(OH){sub 2} and dicobalt tetroxide (Co{sub 2}O{sub 4}) ordered arrays as well as N{sub i}O microspheres were assembled from 0-D nanoparticles, 1-D mesoporous nanowires and nanobelts, and 2-D mesoporous nanopetals. The study showed that all the synthesized nanostructured materials delivered larger energy densities while showing electrochemical stability at high rates.

  5. Effect of high density lipoproteins on permeability of rabbit aorta to low density lipoproteins

    International Nuclear Information System (INIS)

    Klimov, A.N.; Popov, V.A.; Nagornev, V.A.; Pleskov, V.M.

    1985-01-01

    A study was made on the effect of high density lipoproteins (HDL) on the permeability of rabbit aorta to low density lipoproteins (LDL) after intravenous administration of human HDL and human ( 125 I)LDL to normal and hypercholesterolemic rabbits. Evaluation of radioactivity in plasma and aorta has shown that the administration of a large dose of HDL decreased the aorta permeability rate for ( 125 I)LDL on an average by 19% in normal rabbits, and by 45% in rabbits with moderate hypercholesterolemia. A historadiographic study showed that HDL also decreased the vessel wall permeability to ( 125 I)LDL in normal and particularly in hypercholesterolemic animals. The suggestion was made that HDL at very high molar concentration can hamper LDL transportation through the intact endothelial layer into the intima due to the ability of HDL to compete with LDL in sites of low affinity on the surface of endothelial cells. (author)

  6. The collapse of a molecular cloud core to stellar densities using radiation non-ideal magnetohydrodynamics

    Science.gov (United States)

    Wurster, James; Bate, Matthew R.; Price, Daniel J.

    2018-04-01

    We present results from radiation non-ideal magnetohydrodynamics (MHD) calculations that follow the collapse of rotating, magnetized, molecular cloud cores to stellar densities. These are the first such calculations to include all three non-ideal effects: ambipolar diffusion, Ohmic resistivity, and the Hall effect. We employ an ionization model in which cosmic ray ionization dominates at low temperatures and thermal ionization takes over at high temperatures. We explore the effects of varying the cosmic ray ionization rate from ζcr = 10-10 to 10-16 s-1. Models with ionization rates ≳10-12 s-1 produce results that are indistinguishable from ideal MHD. Decreasing the cosmic ray ionization rate extends the lifetime of the first hydrostatic core up to a factor of 2, but the lifetimes are still substantially shorter than those obtained without magnetic fields. Outflows from the first hydrostatic core phase are launched in all models, but the outflows become broader and slower as the ionization rate is reduced. The outflow morphology following stellar core formation is complex and strongly dependent on the cosmic ray ionization rate. Calculations with high ionization rates quickly produce a fast (≈14 km s-1) bipolar outflow that is distinct from the first core outflow, but with the lowest ionization rate, a slower (≈3-4 km s-1) conical outflow develops gradually and seamlessly merges into the first core outflow.

  7. A high energy density relaxor antiferroelectric pulsed capacitor dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Hwan Ryul; Lynch, Christopher S. [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles (UCLA), Los Angeles, California 90095 (United States)

    2016-01-14

    Pulsed capacitors require high energy density and low loss, properties that can be realized through selection of composition. Ceramic (Pb{sub 0.88}La{sub 0.08})(Zr{sub 0.91}Ti{sub 0.09})O{sub 3} was found to be an ideal candidate. La{sup 3+} doping and excess PbO were used to produce relaxor antiferroelectric behavior with slim and slanted hysteresis loops to reduce the dielectric hysteresis loss, to increase the dielectric strength, and to increase the discharge energy density. The discharge energy density of this composition was found to be 3.04 J/cm{sup 3} with applied electric field of 170 kV/cm, and the energy efficiency, defined as the ratio of the discharge energy density to the charging energy density, was 0.920. This high efficiency reduces the heat generated under cyclic loading and improves the reliability. The properties were observed to degrade some with temperature increase above 80 °C. Repeated electric field cycles up to 10 000 cycles were applied to the specimen with no observed performance degradation.

  8. Antioxidant activity of high-density lipoprotein (HDL) using different ...

    African Journals Online (AJOL)

    HDL is a potent antioxidant in terms of inhibition of lipid peroxidation, ROS production and LDL oxidation. These may to some extent add to the antiatherogenic beyond reverse-cholesterol transport properties of HDL. Keywords: high-density lipoprotein; reverse cholesterol transport; apolipoprotein A1; antioxidant; in vitro.

  9. High energy density in matter produced by heavy ion beams

    International Nuclear Information System (INIS)

    1987-08-01

    This annual report summarizes the results of research carried out in 1986 within the framework of the program 'High Energy Density in Matter Produced by Heavy Ion Beams' which is funded by the Federal Ministry for Research and Technology. Its initial motivation and its ultimate goal is the question whether inertial confinement can be achieved by intense beams of heavy ions. (orig./HSI)

  10. Ultra-stretchable Interconnects for high-density stretchable electronics

    NARCIS (Netherlands)

    Shafqat, S.; Hoefnagels, J.P.M.; Savov, A.; Joshi, S.; Dekker, R.; Geers, M.G.D.

    2017-01-01

    The exciting field of stretchable electronics (SE) promises numerous novel applications, particularly in-body and medical diagnostics devices. However, future advanced SE miniature devices will require high-density, extremely stretchable interconnects with micron-scale footprints, which calls for

  11. A high current density DC magnetohydrodynamic (MHD) micropump

    NARCIS (Netherlands)

    Homsy, Alexandra; Koster, Sander; Hogen-Koster, S.; Eijkel, Jan C.T.; van den Berg, Albert; Lucklum, F.; Verpoorte, E.; de Rooij, Nico F.

    2005-01-01

    This paper describes the working principle of a DC magnetohydrodynamic (MHD) micropump that can be operated at high DC current densities (J) in 75-µm-deep microfluidic channels without introducing gas bubbles into the pumping channel. The main design feature for current generation is a micromachined

  12. A high current density DC magnetohydrodynamic (MHD) micropump

    NARCIS (Netherlands)

    Homsy, A; Koster, Sander; Eijkel, JCT; van den Berg, A; Lucklum, F; Verpoorte, E; de Rooij, NF

    2005-01-01

    This paper describes the working principle of a DC magnetohydrodynamic (MHD) micropump that can be operated at high DC current densities (J) in 75-mu m-deep microfluidic channels without introducing gas bubbles into the pumping channel. The main design feature for current generation is a

  13. Patterned magnetic thin films for ultra high density recording

    NARCIS (Netherlands)

    Haast, M.A.M.

    This thesis describes the results of a research project in the field of high bit-density data-storage media. More specifically, the material aspects of the novel recording technique using patterned media have been studied. The aim of the work was the design, realization and characterization of such

  14. Role of Lipids in Spheroidal High Density Lipoproteins

    NARCIS (Netherlands)

    Vuorela, Timo; Catte, Andrea; Niemela, Perttu S.; Hall, Anette; Hyvonen, Marja T.; Marrink, Siewert-Jan; Karttunen, Mikko; Vattulainen, Ilpo

    2010-01-01

    We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules

  15. Role of lipids in spheroidal high density lipoproteins

    NARCIS (Netherlands)

    Vuorela, T.A.; Catte, A.; Niemelä, P.S.; Hall, A.; Hyvönen, M.T.; Marrink, S.J.; Karttunen, M.E.J.; Vattulainen, I.

    2010-01-01

    We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules

  16. Interfacial stick–slip transition in hydroxyapatite filled high density ...

    Indian Academy of Sciences (India)

    Unknown

    flow curves of composites and that of unfilled system remain identical. Filler addition lowers the .... Injection moulding grade high density polyethylene,. HD6070EA, was ... rheometer (Rosand Precision Ltd., UK) using version. 6⋅10 software. .... Bagley E B, Cabbot I M and West D C 1958 J. Appl. Phys. 29. 109. Blyler L L and ...

  17. Searching for high baryon density at the AGS with ARC

    International Nuclear Information System (INIS)

    Kahana, S.H.; Schlagel, T.J.; Pang, Y.

    1993-08-01

    A relativistic cascade ARC is used to analyse heavy ion experiments at the AGS. In particular predictions from ARC for Au on Au at 11.6 GeV/c have proved to be remarkably accurate. Going to lower energies and inserting a phenomenological equation of state into the cascade should lead to information about the interesting region of high baryon density

  18. CSR of Lanzhou and nuclear physics at high densities

    International Nuclear Information System (INIS)

    Zhuang Pengfei; Zhao Weiqin

    1999-01-01

    The possibility to produce highly dense nuclear matter at CSR of Lanzhou and the corresponding signals at final state are discussed. Especially, the maximum baryon density reached at CSR is estimated, and the subthreshold production and hadronic flow risen from the partial restoration of chiral symmetry at CSR energies are analyzed

  19. The Influence of Decreased Levels of High Density Lipoprotein ...

    African Journals Online (AJOL)

    Background: Changes in lipoproteins levels in sickle cell disease (SCD) patients are well.known, but the physiological ramifications of the low levels observed have not been entirely resolved. Aim: The aim of this study is to evaluate the impact of decreased levels of high density lipoprotein cholesterol (HDL.c) on ...

  20. Evaporation of carbon using electrons of a high density plasma

    International Nuclear Information System (INIS)

    Muhl, S.; Camps, E.; Escobar A, L.; Garcia E, J.L.; Olea, O.

    1999-01-01

    The high density plasmas are used frequently in the preparation of thin films or surface modification, for example to nitridation. In these processes, are used mainly the ions and the neutrals which compose the plasma. However, the electrons present in the plasma are not used, except in the case of chemical reactions induced by collisions, although the electron bombardment usually get hot the work piece. Through the adequate polarization of a conductor material, it is possible to extract electrons from a high density plasma at low pressure, that could be gotten the evaporation of this material. As result of the interaction between the plasma and the electron flux with the vapor produced, this last will be ionized. In this work, it is reported the use of this novelty arrangement to prepare carbon thin films using a high density argon plasma and a high purity graphite bar as material to evaporate. It has been used substrates outside plasma and immersed in the plasma. Also it has been reported the plasma characteristics (temperature and electron density, energy and ions flux), parameters of the deposit process (deposit rate and ion/neutral rate) as well as the properties of the films obtained (IR absorption spectra and UV/Vis, elemental analysis, hardness and refractive index. (Author)

  1. Extreme states of matter high energy density physics

    CERN Document Server

    Fortov, Vladimir E

    2016-01-01

    With its many beautiful colour pictures, this book gives fascinating insights into the unusual forms and behaviour of matter under extremely high pressures and temperatures. These extreme states are generated, among other things, by strong shock, detonation and electric explosion waves, dense laser beams,electron and ion beams, hypersonic entry of spacecraft into dense atmospheres of planets, and in many other situations characterized by extremely high pressures and temperatures.Written by one of the world's foremost experts on the topic, this book will inform and fascinate all scientists dealing with materials properties and physics, and also serve as an excellent introduction to plasma-, shock-wave and high-energy-density physics for students and newcomers seeking an overview. This second edition is thoroughly revised and expanded, in particular with new material on high energy-density physics, nuclear explosions and other nuclear transformation processes.

  2. High fidelity chemistry and radiation modeling for oxy -- combustion scenarios

    Science.gov (United States)

    Abdul Sater, Hassan A.

    Dissipation Concept (EDC) employing a 41-step detailed chemistry mechanism, the non-adiabatic extension of the equilibrium Probability Density Function (PDF) based mixture-fraction model and a two-step global finite rate chemistry model with modified rate constants proposed to work well in oxy-methane flames. Based on the results from this section, the equilibrium PDF model in conjunction with a high-fidelity non-gray model for the radiative properties of the gas-phase may be deemed as accurate to capture the major gas species concentrations, temperatures and flame lengths in oxy-methane flames. The third section examines the variations in radiative transfer predictions due to the choice of chemistry and gas-phase radiative property models. The radiative properties were estimated employing four weighted-sum-of-gray-gases models (WSGGM) that were formulated employing different spectroscopic/model databases. An average variation of 14 -- 17% in the wall incident radiative fluxes was observed between the EDC and equilibrium mixture fraction chemistry models, due to differences in their temperature predictions within the flame. One-dimensional, line-of-sight radiation calculations showed a 15 -- 25 % reduction in the directional radiative fluxes at lower axial locations as a result of ignoring radiation from CO and CH4. Under the constraints of fixed temperature and species distributions, the flame radiant power estimates and average wall incident radiative fluxes varied by nearly 60% and 11% respectively among the different WSGG models.

  3. High energy density and extreme field physics in the transparent-overdense regime

    Energy Technology Data Exchange (ETDEWEB)

    Hegelich, Bjorn Manuel [Los Alamos National Laboratory; Yin, Kin [Los Alamos National Laboratory; Albright, Brian J [Los Alamos National Laboratory; Bowers, Kevin J [Los Alamos National Laboratory; Gautier, C [Los Alamos National Laboratory; Huang, C [Los Alamos National Laboratory; Jung, D [Los Alamos National Laboratory; Letzring, S [Los Alamos National Laboratory; Palaniyappan, S [Los Alamos National Laboratory; Shah, R [Los Alamos National Laboratory; Wu, H [Los Alamos National Laboratory; Fernandez, J. C. [Los Alamos National Laboratory; Dromey, B [QUEENS UNIV BELFAST; Henig, A [LUDWIG-MAXIMILLAN-UNIV MUNCHEN; Horlein, R [LUDWIG-MAXIMILLAN-UNIV MUNCHEN; Kefer, D. [LUDWIG-MAXIMILLAN-UNIV MUNCHEN; Tajima, T [LUDWIG-MAXIMILIN-UNIV MUNCHEN; Yan, X [QUEENS UNIV BELFAST; Habs, D [LUDWIG-MAXIMILIAN-UNIV MUNCHEN

    2011-01-31

    Conclusions of this report are: (1) high harmonics generated on solid surfaces are a very versatile source of intense coherent XUV radiation; (2) high harmonics can be used to probe and monitor the interaction of intense femtosecond laser pulses with nm-scale foil targets; (3) direct measurement of target density during relativistic interaction; (4) high harmonics generated with PW-scale short-pulse lasers could serve as unique backlighting sources for a wide range experiments; and (5) Trident can be a test bed to develop such experiments and the required instrumentation.

  4. Degradation behavior of linear low density polyethylene by ultraviolet radiation exposition for agricultural applications

    Energy Technology Data Exchange (ETDEWEB)

    Poveda, Patricia N.S.; Silva, Leonardo G.A., E-mail: lgasilva@ipen.br, E-mail: patricianegrini@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Ciro, Rosemeire, E-mail: rosemeireciro@msn.com [Faculdades Oswaldo Cruz (FOC), Sao Paulo, SP (Brazil); Viana, Hamilton M., E-mail: hmviana@gmail.com [Centro Universitario Fundacao de Santo Andre (FSA/FAENG), Santo Andre, SP (Brazil)

    2013-07-01

    Polyethylene is the most important polymer used in agricultural applications. Polymers are susceptible to changes in their chemical structures that affect their mechanical properties under weather condition. In Polyethylene, photo-oxidation can occur because of impurities or chromophore groups (catalytic residue, mineral fillers, some commercial additives as stabilizers, lubricants, plasticizers, etc.). The critical ageing factors for greenhouse built with LDPE film are: total solar radiation, air temperature, relative humidity, mechanical stress, agrochemicals, air pollution, and combinations of these factors. Exposure of plastics to UV radiation causes a loss in their mechanical properties and/or change in appearance, including reduced ductility, color changes, yellowing and cracking. Additives are added to plastics to enhance the durability of the final product. Today, there are several additive systems (light stabilizers) developed to work according to resin, final application, type of cultivation, and other characteristics. The main types of light stabilizers are: UV absorbers, quenchers and free radicals scavengers. In addition to the conventional organic additives, some inorganic additives were obtained recently with the development of nanotechnology. This study evaluates the different additive systems (HALS, NPCC, nZnO and nTiO{sub 2}), applied 0.25% (in weight) in LLDPE. The samples were mixed by high rotation homogenizer and extrusion. Later, the samples were molded by injection and aged in QUV-B simulating 6 months of exposure to weather. Tests of FT-IR and tensile strength comparing to the non-aged samples were carried out in order to evaluate the performance of several additive systems concerning the degradation behavior of linear low density polyethylene. (author)

  5. Degradation behavior of linear low density polyethylene by ultraviolet radiation exposition for agricultural applications

    International Nuclear Information System (INIS)

    Poveda, Patricia N.S.; Silva, Leonardo G.A.; Ciro, Rosemeire; Viana, Hamilton M.

    2013-01-01

    Polyethylene is the most important polymer used in agricultural applications. Polymers are susceptible to changes in their chemical structures that affect their mechanical properties under weather condition. In Polyethylene, photo-oxidation can occur because of impurities or chromophore groups (catalytic residue, mineral fillers, some commercial additives as stabilizers, lubricants, plasticizers, etc.). The critical ageing factors for greenhouse built with LDPE film are: total solar radiation, air temperature, relative humidity, mechanical stress, agrochemicals, air pollution, and combinations of these factors. Exposure of plastics to UV radiation causes a loss in their mechanical properties and/or change in appearance, including reduced ductility, color changes, yellowing and cracking. Additives are added to plastics to enhance the durability of the final product. Today, there are several additive systems (light stabilizers) developed to work according to resin, final application, type of cultivation, and other characteristics. The main types of light stabilizers are: UV absorbers, quenchers and free radicals scavengers. In addition to the conventional organic additives, some inorganic additives were obtained recently with the development of nanotechnology. This study evaluates the different additive systems (HALS, NPCC, nZnO and nTiO 2 ), applied 0.25% (in weight) in LLDPE. The samples were mixed by high rotation homogenizer and extrusion. Later, the samples were molded by injection and aged in QUV-B simulating 6 months of exposure to weather. Tests of FT-IR and tensile strength comparing to the non-aged samples were carried out in order to evaluate the performance of several additive systems concerning the degradation behavior of linear low density polyethylene. (author)

  6. measurement of high dose radiation using yellow perspex dosimeter

    International Nuclear Information System (INIS)

    Thamrin, M Thoyib; Sofyan, Hasnel

    1996-01-01

    Measurement of high dose radiation using yellow perspex dosemeter has been carried out. Dose range used was between 0.1 to 3.0 kGy. Measurement of dose rate against Fricke dosemeter as a standard dose meter From the irradiation of Fricke dosemeter with time variation of 3,6,9,12,15 and 18 minute, it was obtained average dose rate of 955.57 Gy/hour, linear equation of dose was Y= 2.333+15.776 X with its correlation factor r = 0.9999. Measurement result using yellow perspex show that correlation between net optical density and radiation dose was not linear with its equation was ODc exp. [Bo + In(dose).Bi] Value of Bo = -0.215 and Bi=0.5020. From the experiment it was suggested that routine dosimeter (yellow perspex) should be calibrated formerly against standard dosemeters

  7. Chemical protection from high LET radiation

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  8. Relativistic many-body theory of high density matter

    International Nuclear Information System (INIS)

    Chin, S.A.

    1977-01-01

    A fully relativistic quantum many-body theory is applied to the study of high-density matter. The latter is identified with the zero-temperature ground state of a system of interacting baryons. In accordance with the observed short-range repulsive and long-range attractive character of the nucleon--nucleon force, baryons are described as interacting with each other via a massive scalar and a massive vector meson exchange. In the Hartree approximation, the theory yields the same result as the mean-field theory, but with additional vacuum fluctuation corrections. The resultant equation of state for neutron matter is used to determine properties of neutron stars. The relativistic exchange energy, its corresponding single-particle excitation spectrum, and its effect on the neutron matter equation of state, are calculated. The correlation energy from summing the set of ring diagrams is derived directly from the energy-momentum tensor, with renormalization carried out by adding counterterms to the original Lagrangian and subtracting purely vacuum expectation values. Terms of order g 4 lng 2 are explicitly given. Effects of scalar-vector mixing are discussed. Collective modes corresponding to macroscopic density fluctuation are investigated. Two basic modes are found, a plasma-like mode and zero sound, with the latter dominant at high density. The stability and damping of these modes are studied. Last, the effect of vacuum polarization in high-density matter is examined

  9. Electrical characteristics of high density, high purity titanate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Lupfer, D A [Electronics Laboratory, General Electric Company, Syracuse, NY (United States)

    1958-07-01

    This report is concerned with the electrical behaviour of cubic (Ba,Sr)TiO{sub 3} ceramics at very high values of the electric field. The work was undertaken to develop a dielectric system to be used in capacitors for the storage and discharge of electrical energy. Objectives for the finished system were to store large amounts of energy per unit volume, to release at least 75% of the energy in 0.2 x 10{sup -6} seconds, and to operate over a limited temperature range above 20 deg. C. The work is incomplete, but the results to date show that (Ba,Sr) TiO{sub 3} ceramics can store more electrical energy per unit volume than any other known dielectric system.

  10. High-Sensitivity Measurement of Density by Magnetic Levitation.

    Science.gov (United States)

    Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

    2016-03-01

    This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

  11. Calculations on the vibrational level density in highly excited formaldehyde

    International Nuclear Information System (INIS)

    Rashev, Svetoslav; Moule, David C.

    2003-01-01

    The object of the present work is to develop a model that provides realistic estimates of the vibrational level density in polyatomic molecules in a given electronic state, at very high (chemically relevant) vibrational excitation energies. For S 0 formaldehyde (D 2 CO), acetylene, and a number of triatomics, the estimates using conventional spectroscopic formulas have yielded densities at the dissociation threshold, very much lower than the experimentally measured values. In the present work we have derived a general formula for the vibrational energy levels of a polyatomic molecule, which is a generalization of the conventional Dunham spectroscopic expansion. Calculations were performed on the vibrational level density in S 0 D 2 CO, H 2 C 2 , and NO 2 at excitation energies in the vicinity of the dissociation limit, using the newly derived formula. The results from the calculations are in reasonable agreement with the experimentally measured data

  12. Rf Gun with High-Current Density Field Emission Cathode

    International Nuclear Information System (INIS)

    Jay L. Hirshfield

    2005-01-01

    High current-density field emission from an array of carbon nanotubes, with field-emission-transistor control, and with secondary electron channel multiplication in a ceramic facing structure, have been combined in a cold cathode for rf guns and diode guns. Electrodynamic and space-charge flow simulations were conducted to specify the cathode configuration and range of emission current density from the field emission cold cathode. Design of this cathode has been made for installation and testing in an existing S-band 2-1/2 cell rf gun. With emission control and modulation, and with current density in the range of 0.1-1 kA/cm2, this cathode could provide performance and long-life not enjoyed by other currently-available cathodes

  13. Heavy density concrete for nuclear radiation shielding and power stations: [Part]3

    International Nuclear Information System (INIS)

    Singha Roy, P.K.

    1987-01-01

    This article is the third part of the paper entitled 'Heavy density concrete for nuclear radiation shielding and power stations'. Specific considerations relevant to natural but manufactured heavy aggregates like haematite used in India are briefly discussed. They include water-cement ratio, strength versus water-cement ratio, mix design strength and aggregate grading. Some typical mix proportions in haematite concretes used in India are given. Equipment for heavy density concrete is mentioned. Quality control methods and tests for heavy density concrete are described under the heading: type and chemical composition of the rock, specific gravity and surface absorption of the aggregates, grading of aggregates, cement, batching, mixing, compressive strength, and density. Construction aspects such as form work, placement, vibration, finishing, and temperature control are discussed. Finally it is pointed out that for optimising the design and economy of heavy density concrete, it is necessary to carry out country-wide survey of suitable materials, to study their properties, suitability and effectiveness in shielding radiation. (M.G.B.)

  14. Density Functional Methods for Shock Physics and High Energy Density Science

    Science.gov (United States)

    Desjarlais, Michael

    2017-06-01

    Molecular dynamics with density functional theory has emerged over the last two decades as a powerful and accurate framework for calculating thermodynamic and transport properties with broad application to dynamic compression, high energy density science, and warm dense matter. These calculations have been extensively validated against shock and ramp wave experiments, are a principal component of high-fidelity equation of state generation, and are having wide-ranging impacts on inertial confinement fusion, planetary science, and shock physics research. In addition to thermodynamic properties, phase boundaries, and the equation of state, one also has access to electrical conductivity, thermal conductivity, and lower energy optical properties. Importantly, all these properties are obtained within the same theoretical framework and are manifestly consistent. In this talk I will give a brief history and overview of molecular dynamics with density functional theory and its use in calculating a wide variety of thermodynamic and transport properties for materials ranging from ambient to extreme conditions and with comparisons to experimental data. I will also discuss some of the limitations and difficulties, as well as active research areas. Sandia is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  15. High follicle density does not decrease sweat gland density in Huacaya alpacas.

    Science.gov (United States)

    Moore, K E; Maloney, S K; Blache, D

    2015-01-01

    When exposed to high ambient temperatures, mammals lose heat evaporatively by either sweating from glands in the skin or by respiratory panting. Like other camelids, alpacas are thought to evaporate more water by sweating than panting, despite a thick fleece, unlike sheep which mostly pant in response to heat stress. Alpacas were brought to Australia to develop an alternative fibre industry to sheep wool. In Australia, alpacas can be exposed to ambient temperatures higher than in their native South America. As a young industry there is a great deal of variation in the quality and quantity of the fleece produced in the national flock. There is selection pressure towards animals with finer and denser fleeces. Because the fibre from secondary follicles is finer than that from primary follicles, selecting for finer fibres might alter the ratio of primary and secondary follicles. In turn the selection might alter sweat gland density because the sweat glands are associated with the primary follicle. Skin biopsy and fibre samples were obtained from the mid-section of 33 Huacaya alpacas and the skin sections were processed into horizontal sections at the sebaceous gland level. Total, primary, and secondary follicles and the number of sweat gland ducts were quantified. Fibre samples from each alpaca were further analysed for mean fibre diameter. The finer-fibred animals had a higher total follicle density (Palpacas with high follicle density should not be limited for potential sweating ability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Metal hydrides based high energy density thermal battery

    International Nuclear Information System (INIS)

    Fang, Zhigang Zak; Zhou, Chengshang; Fan, Peng; Udell, Kent S.; Bowman, Robert C.; Vajo, John J.; Purewal, Justin J.; Kekelia, Bidzina

    2015-01-01

    Highlights: • The principle of the thermal battery using advanced metal hydrides was demonstrated. • The thermal battery used MgH 2 and TiMnV as a working pair. • High energy density can be achieved by the use of MgH 2 to store thermal energy. - Abstract: A concept of thermal battery based on advanced metal hydrides was studied for heating and cooling of cabins in electric vehicles. The system utilized a pair of thermodynamically matched metal hydrides as energy storage media. The pair of hydrides that was identified and developed was: (1) catalyzed MgH 2 as the high temperature hydride material, due to its high energy density and enhanced kinetics; and (2) TiV 0.62 Mn 1.5 alloy as the matching low temperature hydride. Further, a proof-of-concept prototype was built and tested, demonstrating the potential of the system as HVAC for transportation vehicles

  17. High energy-density science on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, E.M.; Cauble, R.; Remington, B.A.

    1997-08-01

    The National Ignition Facility, as well as its French counterpart Le Laser Megajoule, have been designed to confront one of the most difficult and compelling problem in shock physics - the creation of a hot, compassed DT plasma surrounded and confined by cold, nearly degenerate DT fuel. At the same time, these laser facilities will present the shock physics community with unique tools for the study of high energy density matter at states unreachable by any other laboratory technique. Here we describe how these lasers can contribute to investigations of high energy density in the area of material properties and equations of state, extend present laboratory shock techniques such as high-speed jets to new regimes, and allow study of extreme conditions found in astrophysical phenomena.

  18. Characterization of the high density plasma etching process of CCTO thin films for the fabrication of very high density capacitors

    International Nuclear Information System (INIS)

    Altamore, C; Tringali, C; Sparta', N; Marco, S Di; Grasso, A; Ravesi, S

    2010-01-01

    In this work the feasibility of CCTO (Calcium Copper Titanate) patterning by etching process is demonstrated and fully characterized in a hard to etch materials etcher. CCTO sintered in powder shows a giant relative dielectric constant (10 5 ) measured at 1 MHz at room temperature. This feature is furthermore coupled with stability from 10 1 Hz to 10 6 Hz in a wide temperature range (100K - 600K). In principle, this property can allow to fabricate very high capacitance density condenser. Due to its perovskite multi-component structure, CCTO can be considered a hard to etch material. For high density capacitor fabrication, CCTO anisotropic etching is requested by using high density plasma. The behavior of etched CCTO was studied in a HRe- (High Density Reflected electron) plasma etcher using Cl 2 /Ar chemistry. The relationship between the etch rate and the Cl 2 /Ar ratio was also studied. The effects of RF MHz, KHz Power and pressure variation, the impact of HBr addiction to the Cl 2 /Ar chemistry on the CCTO etch rate and on its selectivity to Pt and photo resist was investigated.

  19. Characterization of the high density plasma etching process of CCTO thin films for the fabrication of very high density capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Altamore, C; Tringali, C; Sparta' , N; Marco, S Di; Grasso, A; Ravesi, S [STMicroelectronics, Industial and Multi-segment Sector R and D, Catania (Italy)

    2010-02-15

    In this work the feasibility of CCTO (Calcium Copper Titanate) patterning by etching process is demonstrated and fully characterized in a hard to etch materials etcher. CCTO sintered in powder shows a giant relative dielectric constant (10{sup 5}) measured at 1 MHz at room temperature. This feature is furthermore coupled with stability from 10{sup 1} Hz to 10{sup 6} Hz in a wide temperature range (100K - 600K). In principle, this property can allow to fabricate very high capacitance density condenser. Due to its perovskite multi-component structure, CCTO can be considered a hard to etch material. For high density capacitor fabrication, CCTO anisotropic etching is requested by using high density plasma. The behavior of etched CCTO was studied in a HRe- (High Density Reflected electron) plasma etcher using Cl{sub 2}/Ar chemistry. The relationship between the etch rate and the Cl{sub 2}/Ar ratio was also studied. The effects of RF MHz, KHz Power and pressure variation, the impact of HBr addiction to the Cl{sub 2}/Ar chemistry on the CCTO etch rate and on its selectivity to Pt and photo resist was investigated.

  20. Conductivity of ion dielectrics during the mean flux-density electron- and X-ray pulse radiation

    International Nuclear Information System (INIS)

    Vajsburd, D.I.; Mesyats, G.A.; Naminov, V.L.; Tavanov, Eh.G.

    1982-01-01

    Conductivity of ion dielectrics under electron and X-ray pulse radiation is investigated. Investigations have been conducted in the range of average beam densities in which extinction of low-energy conductivity takes place. Thin plates of alkali-halogen crystals have been used as samples. Small-dimensional accelerator with controlled beam parameters: 1-20 ns, 0.1-2000 A/cm 2 , 0.3-0.5 MeV has been used for radiation. Temperature dependence of conductivity current pulse is determined. Time resolution of 10 - 10 s is achieved. In the 70-300 K range it practically coincides with radiation pulse. An essential inertial constituent is observed below 300 K. It is shown that at average beam densities a comparable contribution into fast conductivity is made by intracentre conductivity independent of temperature and high-temperature conductivity which decreases with temperature with activation energy equal to the energy of short-wave background. That is why amplitude of fast constituent decreases with temperature slower than high-energy conductivity

  1. High power density yeast catalyzed microbial fuel cells

    Science.gov (United States)

    Ganguli, Rahul

    Microbial fuel cells leverage whole cell biocatalysis to convert the energy stored in energy-rich renewable biomolecules such as sugar, directly to electrical energy at high efficiencies. Advantages of the process include ambient temperature operation, operation in natural streams such as wastewater without the need to clean electrodes, minimal balance-of-plant requirements compared to conventional fuel cells, and environmentally friendly operation. These make the technology very attractive as portable power sources and waste-to-energy converters. The principal problem facing the technology is the low power densities compared to other conventional portable power sources such as batteries and traditional fuel cells. In this work we examined the yeast catalyzed microbial fuel cell and developed methods to increase the power density from such fuel cells. A combination of cyclic voltammetry and optical absorption measurements were used to establish significant adsorption of electron mediators by the microbes. Mediator adsorption was demonstrated to be an important limitation in achieving high power densities in yeast-catalyzed microbial fuel cells. Specifically, the power densities are low for the length of time mediator adsorption continues to occur. Once the mediator adsorption stops, the power densities increase. Rotating disk chronoamperometry was used to extract reaction rate information, and a simple kinetic expression was developed for the current observed in the anodic half-cell. Since the rate expression showed that the current was directly related to microbe concentration close to the electrode, methods to increase cell mass attached to the anode was investigated. Electrically biased electrodes were demonstrated to develop biofilm-like layers of the Baker's yeast with a high concentration of cells directly connected to the electrode. The increased cell mass did increase the power density 2 times compared to a non biofilm fuel cell, but the power density

  2. Mixing of high density solution in vertical upward flow

    International Nuclear Information System (INIS)

    Kumamaru, Hiroshige; Hosogi, Nobuyoshi; Komada, Toshiaki; Fujiwara, Yoshiki

    1999-01-01

    Experimental and analytical studies have been performed in order to provide fundamental data and a numerical calculation model on the mixing of boric acid solution, injected from the standby liquid control system (SLCS), under a low natural circulation flow during an ATWS in a BWR. First, fundamental experiments on the mixing of high-density solution in vertically-upward water flow have been performed by using a small apparatus. Mixing patterns observed in the experiments have been classified to two groups, i.e. complete mixing (entrainment) and incomplete mixing (entrainment). In the complete mixing, the injected high-density solution is mixed (entrained) completely into the vertically-upward water flow. From the experiments, the minimum water flow rates in which the complete mixing (entrainment) is achieved have been obtained for various solution densities and solution injection rates. Secondly, two-dimensional numerical calculations have been performed. A continuity equation for total fluid, momentum equations in two directions and a continuity equation for solute are solved by using the finite difference method for discretization method and by following the MAC method for solution procedure. The calculations have predicted nearly the minimum water flow rate in which the complete mixing is achieved, while the calculations have been performed only for one combination of the solution density and solution injection rate until now. (author)

  3. High-density housing that works for all

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Arif

    2010-03-15

    In an urbanising world, the way people fit into cities is vastly important - socially, economically, environmentally, even psychologically. So density, or the number of people living in a given area, is central to urban design and planning. Both governments and markets tend to get density wrong, leading to overcrowding, urban sprawl or often both. A case in point are the high-rise buildings springing up throughtout urban Asia - perceived as key features of that widely touted concept, the 'world-class city'. While some may offer a viable solution to land pressures and density requirements, many built to house evicted or resettled 'slum' dwellers are a social and economic nightmare - inconveniently sited, overcrowded and costly. New evidence from Karachi, Pakistan, reveals a real alternative. Poor people can create liveable high-density settlements as long as community control, the right technical assistance and flexible designs are in place. A city is surely 'world-class' only when it is cosmopolitan – built to serve all, including the poorest.

  4. Highly heat removing radiation shielding material

    International Nuclear Information System (INIS)

    Asano, Norio; Hozumi, Masahiro.

    1990-01-01

    Organic materials, inorganic materials or metals having excellent radiation shielding performance are impregnated into expanded metal materials, such as Al, Cu or Mg, having high heat conductivity. Further, the porosity of the expanded metals and combination of the expanded metals and the materials to be impregnated are changed depending on the purpose. Further, a plurality of shielding materials are impregnated into the expanded metal of the same kind, to constitute shielding materials. In such shielding materials, impregnated materials provide shielding performance against radiation rays such as neutrons and gamma rays, the expanded metals provide heat removing performance respectively and they act as shielding materials having heat removing performance as a whole. Accordingly, problems of non-informity and discontinuity in the prior art can be dissolved be provide materials having flexibility in view of fabrication work. (T.M.)

  5. Multiplexed, high density electrophysiology with nanofabricated neural probes.

    Directory of Open Access Journals (Sweden)

    Jiangang Du

    Full Text Available Extracellular electrode arrays can reveal the neuronal network correlates of behavior with single-cell, single-spike, and sub-millisecond resolution. However, implantable electrodes are inherently invasive, and efforts to scale up the number and density of recording sites must compromise on device size in order to connect the electrodes. Here, we report on silicon-based neural probes employing nanofabricated, high-density electrical leads. Furthermore, we address the challenge of reading out multichannel data with an application-specific integrated circuit (ASIC performing signal amplification, band-pass filtering, and multiplexing functions. We demonstrate high spatial resolution extracellular measurements with a fully integrated, low noise 64-channel system weighing just 330 mg. The on-chip multiplexers make possible recordings with substantially fewer external wires than the number of input channels. By combining nanofabricated probes with ASICs we have implemented a system for performing large-scale, high-density electrophysiology in small, freely behaving animals that is both minimally invasive and highly scalable.

  6. High sensitive radiation detector for radiology dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Valente, M.; Malano, F. [Instituto de Fisica Enrique Gaviola, Oficina 102 FaMAF - UNC, Av. Luis Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Molina, W.; Vedelago, J., E-mail: valente@famac.unc.edu.ar [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2014-08-15

    Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, dose rate recorded and incident direction independence as well as linear dose response. This work presents the development and characterization of a novel Fricke gel system, based on modified chemical compositions making possible its application in clinical radiology. Properties of standard Fricke gel dosimeter for high dose levels are used as starting point and suitable chemical modifications are introduced and carefully investigated in order to attain high resolution for low dose ranges, like those corresponding to radiology interventions. The developed Fricke gel radiation dosimeter system achieves the expected typical dose dependency, actually showing linear response in the dose range from 20 up to 4000 mGy. Systematic investigations including several chemical compositions are carried out in order to obtain a good enough dosimeter response for low dose levels. A suitable composition among those studied is selected as a good candidate for low dose level radiation dosimetry consisting on a modified Fricke solution fixed to a gel matrix containing benzoic acid along with sulfuric acid, ferrous sulfate, xylenol orange and ultra-pure reactive grade water. Dosimeter samples are prepared in standard vials for its in phantom irradiation and further characterization by spectrophotometry measuring visible light transmission and absorbance before and after irradiation. Samples are irradiated by typical kV X-ray tubes and calibrated Farmer type ionization chamber is used as reference to measure dose rates inside phantoms in at vials locations. Once sensitive material composition is already optimized, dose-response curves show significant improvement regarding overall sensitivity for low dose levels. According to

  7. High sensitive radiation detector for radiology dosimetry

    International Nuclear Information System (INIS)

    Valente, M.; Malano, F.; Molina, W.; Vedelago, J.

    2014-08-01

    Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, dose rate recorded and incident direction independence as well as linear dose response. This work presents the development and characterization of a novel Fricke gel system, based on modified chemical compositions making possible its application in clinical radiology. Properties of standard Fricke gel dosimeter for high dose levels are used as starting point and suitable chemical modifications are introduced and carefully investigated in order to attain high resolution for low dose ranges, like those corresponding to radiology interventions. The developed Fricke gel radiation dosimeter system achieves the expected typical dose dependency, actually showing linear response in the dose range from 20 up to 4000 mGy. Systematic investigations including several chemical compositions are carried out in order to obtain a good enough dosimeter response for low dose levels. A suitable composition among those studied is selected as a good candidate for low dose level radiation dosimetry consisting on a modified Fricke solution fixed to a gel matrix containing benzoic acid along with sulfuric acid, ferrous sulfate, xylenol orange and ultra-pure reactive grade water. Dosimeter samples are prepared in standard vials for its in phantom irradiation and further characterization by spectrophotometry measuring visible light transmission and absorbance before and after irradiation. Samples are irradiated by typical kV X-ray tubes and calibrated Farmer type ionization chamber is used as reference to measure dose rates inside phantoms in at vials locations. Once sensitive material composition is already optimized, dose-response curves show significant improvement regarding overall sensitivity for low dose levels. According to

  8. Line radiation of multicharged ions with the Fermi-Dirac level distribution of electrons at high temperatures

    International Nuclear Information System (INIS)

    Garanin, S.F.

    2003-01-01

    Line radiation of multicharged ions with the Fermi-Dirac electron distribution by levels in the range of plasma temperatures, when electron movement may be considered quasiclassical, while potential, in which they move, is the Coulomb one, is considered. The spectrum and intensity of ion radiation are calculated. Within high plasma densities the radiation intensity per one ion proved to be independent of density and proportional to T 2 [ru

  9. The use of low density high accuracy (LDHA) data for correction of high density low accuracy (HDLA) point cloud

    Science.gov (United States)

    Rak, Michal Bartosz; Wozniak, Adam; Mayer, J. R. R.

    2016-06-01

    Coordinate measuring techniques rely on computer processing of coordinate values of points gathered from physical surfaces using contact or non-contact methods. Contact measurements are characterized by low density and high accuracy. On the other hand optical methods gather high density data of the whole object in a short time but with accuracy at least one order of magnitude lower than for contact measurements. Thus the drawback of contact methods is low density of data, while for non-contact methods it is low accuracy. In this paper a method for fusion of data from two measurements of fundamentally different nature: high density low accuracy (HDLA) and low density high accuracy (LDHA) is presented to overcome the limitations of both measuring methods. In the proposed method the concept of virtual markers is used to find a representation of pairs of corresponding characteristic points in both sets of data. In each pair the coordinates of the point from contact measurements is treated as a reference for the corresponding point from non-contact measurement. Transformation enabling displacement of characteristic points from optical measurement to their match from contact measurements is determined and applied to the whole point cloud. The efficiency of the proposed algorithm was evaluated by comparison with data from a coordinate measuring machine (CMM). Three surfaces were used for this evaluation: plane, turbine blade and engine cover. For the planar surface the achieved improvement was of around 200 μm. Similar results were obtained for the turbine blade but for the engine cover the improvement was smaller. For both freeform surfaces the improvement was higher for raw data than for data after creation of mesh of triangles.

  10. Pair-density waves, charge-density waves, and vortices in high-Tc cuprates

    Science.gov (United States)

    Dai, Zhehao; Zhang, Ya-Hui; Senthil, T.; Lee, Patrick A.

    2018-05-01

    A recent scanning tunneling microscopy (STM) experiment reports the observation of a charge-density wave (CDW) with a period of approximately 8a in the halo region surrounding the vortex core, in striking contrast to the approximately 4a period CDWs that are commonly observed in the cuprates. Inspired by this work, we study a model where a bidirectional pair-density wave (PDW) with period 8 is at play. This further divides into two classes: (1) where the PDW is a competing state of the d -wave superconductor and can exist only near the vortex core where the d -wave order is suppressed and (2) where the PDW is the primary order, the so-called "mother state" that persists with strong phase fluctuations to high temperature and high magnetic field and lies behind the pseudogap phenomenology. We study the charge-density wave structures near the vortex core in these models. We emphasize the importance of the phase winding of the d -wave order parameter. The PDW can be pinned by the vortex core due to this winding and become static. Furthermore, the period-8 CDW inherits the properties of this winding, which gives rise to a special feature of the Fourier transform peak, namely, it is split in certain directions. There is also a line of zeros in the inverse Fourier transform of filtered data. We propose that these are key experimental signatures that can distinguish between the PDW-driven scenario from the more mundane option that the period-8 CDW is primary. We discuss the pro's and con's of the options considered above. Finally, we attempt to place the STM experiment in the broader context of pseudogap physics of underdoped cuprates and relate this observation to the unusual properties of x-ray scattering data on CDW carried out to very high magnetic field.

  11. High density thermite mixture for shaped charge ordnance disposal

    Directory of Open Access Journals (Sweden)

    Tamer Elshenawy

    2017-10-01

    Full Text Available The effect of thermite mixture based on aluminum and ferric oxides for ammunition neutralization has been studied and tested. Thermochemical calculations have been carried out for different percentage of Al using Chemical Equilibrium Code to expect the highest performance thermite mixture used for shaped charge ordnance disposal. Densities and enthalpy of different formulations have been calculated and demonstrated. The optimized thermite formulation has been prepared experimentally using cold iso-static pressing technique, which exhibited relatively high density and high burning rate thermite mixture. The produced green product compacted powder mixture was tested against small caliber shaped charge bomblet for neutralization. Theoretical and experimental results showed that the prepared thermite mixture containing 33% of aluminum as a fuel with ferric oxide can be successfully used for shaped charge ordnance disposal.

  12. Lithium-Based High Energy Density Flow Batteries

    Science.gov (United States)

    Bugga, Ratnakumar V. (Inventor); West, William C. (Inventor); Kindler, Andrew (Inventor); Smart, Marshall C. (Inventor)

    2014-01-01

    Systems and methods in accordance with embodiments of the invention implement a lithium-based high energy density flow battery. In one embodiment, a lithium-based high energy density flow battery includes a first anodic conductive solution that includes a lithium polyaromatic hydrocarbon complex dissolved in a solvent, a second cathodic conductive solution that includes a cathodic complex dissolved in a solvent, a solid lithium ion conductor disposed so as to separate the first solution from the second solution, such that the first conductive solution, the second conductive solution, and the solid lithium ionic conductor define a circuit, where when the circuit is closed, lithium from the lithium polyaromatic hydrocarbon complex in the first conductive solution dissociates from the lithium polyaromatic hydrocarbon complex, migrates through the solid lithium ionic conductor, and associates with the cathodic complex of the second conductive solution, and a current is generated.

  13. High frequency characterization of Galfenol minor flux density loops

    Directory of Open Access Journals (Sweden)

    Ling Weng

    2017-05-01

    Full Text Available This paper presents the first measurement of ring-shaped Galfenol’s high frequency-dependent minor flux density loops. The frequencies of applied AC magnetic field are 1k, 5k, 10k, 50k, 100k, 200k, 300k, 500 kHz. The measurements show that the cycle area between the flux density and magnetic field curves increase with increasing frequency. High frequency-dependent characterization, including coercivity, specific power loss, residual induction, and maximum relative permeability are discussed. Minor loops for different max induction are also measured and discussed at the same frequency 100 kHz. Minor loops with the same max induction 0.05 T for different frequencies 50, 100, 200, 300, 400 kHz are measured and specific power loss are discussed.

  14. Preparations of high density (Th,U)O2 pellets

    International Nuclear Information System (INIS)

    Akabori, Mitsuo; Ikawa, Katsuichi

    1986-07-01

    Preparations of high density and homogeneous (Th,U)O 2 pellets by a powder metallurgy method were examined. (Th,U)O 2 powders were prepared by calcining coprecipitates of ammonium uranate and thorium hydroxide derived from nitrates and mixed sols, and by calcining mixed oxalates precipitated from nitrates. (Th,U)O 2 pellets were characterized with respect to sinterability, lattice parameter, microstructure, homogeneity and stoichiometry. Sintering atmospheres had a significant effect upon all the properties of the derived pellets. The sinterability of (Th,U)O 2 was most favourable in oxidizing and reducing atmospheres for ThO 2 -rich and UO 2 -rich compositions, respectively, and can be enhanced by presence of water vapour in sintering atmospheres. In addition, highly homogeneous (Th,U)O 2 pellets with 99 % in theoretical density were derived from the sol powders. (author)

  15. High-energy-density physics researches based on pulse power technology

    International Nuclear Information System (INIS)

    Horioka, Kazuhiko; Nakajima, Mitsuo; Kawamura, Tohru; Sasaki, Toru; Kondo, Kotaro; Yano, Yuuri

    2006-01-01

    Plasmas driven by pulse power device are of interest, concerning the researches on high-energy-density (HED) physics. Dense plasmas are produced using pulse power driven exploding discharges in water. Experimental results show that the wire plasma is tamped and stabilized by the surrounding water and it evolves through a strongly coupled plasma state. A shock-wave-heated, high temperature plasma is produced in a compact pulse power device. Experimental results show that strong shock waves can be produced in the device. In particular, at low initial pressure condition, the shock Mach number reaches 250 and this indicates that the shock heated region is dominated by radiation processes. (author)

  16. Use of high current density superconducting coils in fusion devices

    International Nuclear Information System (INIS)

    Green, M.A.

    1979-11-01

    Superconducting magnets will play an important role in fusion research in years to come. The magnets which are currently proposed for fusion research use the concept of cryostability to insure stable operation of the superconducting coils. This paper proposes the use of adiabatically stable high current density superconducting coils in some types of fusion devices. The advantages of this approach are much lower system cold mass, enhanced cryogenic safety, increased access to the plasma and lower cost

  17. High energy density fusing using the Compact Torus

    International Nuclear Information System (INIS)

    Hartman, C.W.

    1989-01-01

    My remarks are concerned with employing the Compact Torus magnetic field configuration to produce fusion energy. In particular, I would like to consider high energy density regimes where the pressures generated extend well beyond the strength of materials. Under such conditions, where nearby walls are vaporized and pushed aside each shot, the technological constraints are very different from usual magnetic fusion and may admit opportunities for an improved fusion reactor design. 5 refs., 3 figs

  18. Operation and control of high density tokamak reactors

    International Nuclear Information System (INIS)

    Attenberger, S.E.; McAlees, D.G.

    1976-01-01

    The incentive for high density operation of a tokamak reactor is discussed. The plasma size required to attain ignition is determined. Ignition is found to be possible in a relatively small system provided other design criteria are met. These criteria are described and the technology developments and operating procedures required by them are outlined. The parameters for such a system and its dynamic behavior during the operating cycle are also discussed

  19. Anti-Ferroelectric Ceramics for High Energy Density Capacitors

    Directory of Open Access Journals (Sweden)

    Aditya Chauhan

    2015-11-01

    Full Text Available With an ever increasing dependence on electrical energy for powering modern equipment and electronics, research is focused on the development of efficient methods for the generation, storage and distribution of electrical power. In this regard, the development of suitable dielectric based solid-state capacitors will play a key role in revolutionizing modern day electronic and electrical devices. Among the popular dielectric materials, anti-ferroelectrics (AFE display evidence of being a strong contender for future ceramic capacitors. AFE materials possess low dielectric loss, low coercive field, low remnant polarization, high energy density, high material efficiency, and fast discharge rates; all of these characteristics makes AFE materials a lucrative research direction. However, despite the evident advantages, there have only been limited attempts to develop this area. This article attempts to provide a focus to this area by presenting a timely review on the topic, on the relevant scientific advancements that have been made with respect to utilization and development of anti-ferroelectric materials for electric energy storage applications. The article begins with a general introduction discussing the need for high energy density capacitors, the present solutions being used to address this problem, and a brief discussion of various advantages of anti-ferroelectric materials for high energy storage applications. This is followed by a general description of anti-ferroelectricity and important anti-ferroelectric materials. The remainder of the paper is divided into two subsections, the first of which presents various physical routes for enhancing the energy storage density while the latter section describes chemical routes for enhanced storage density. This is followed by conclusions and future prospects and challenges which need to be addressed in this particular field.

  20. Hydrogen incorporation in high hole density GaN:Mg

    Science.gov (United States)

    Zvanut, M. E.; Uprety, Y.; Dashdorj, J.; Moseley, M.; Doolittle, W. Alan

    2011-03-01

    We investigate hydrogen passivation in heavily doped p-type GaN using electron paramagnetic resonance (EPR) spectroscopy. Samples include both conventionally grown GaN (1019 cm-3 Mg, 1017 cm-3 holes) and films grown by metal modulation epitaxy (MME), which yielded higher Mg (1- 4 x 1020 cm-3) and hole (1- 40 x 1018 cm-3) densities than found in conventionally grown GaN. The Mg acceptor signal is monitored throughout 30 minute annealing steps in N2 :H2 (92%:7%)) and subsequently pure N2 . N2 :H2 heat treatments of the lower hole density films begin to reduce the Mg EPR intensity at 750 o C, but quench the signal in high hole density films at 600 o C. Revival of the signal by subsequent N2 annealing occurs at 800 o C for the low hole density material and 600 o C in MME GaN. The present work highlights chemical differences between heavily Mg doped and lower doped films; however, it is unclear whether the difference is due to changes in hydrogen-Mg complex formation or hydrogen diffusion. The work at UAB is supported by the NSF.

  1. Heavy density concrete for nuclear radiation shielding and power stations: [Part]2

    International Nuclear Information System (INIS)

    Singha Roy, P.K.

    1987-01-01

    This article is the second part of the paper entitled 'Heavy density concrete for nuclear radiation shielding and power stations'. In this part, some of the important properties of heavy density concrete are discussed. They include density, water retentivity, air content, permeability with special reference to concrete mixes used in India's nuclear power reactors. All these properties are affected to various extents by heating. Indian shield concrete is rarely subjected to temperatures above 60degC during its life, because of thermal shield protection. During placement, the maximum anticipated rise in temperature due to heat of hydration is restricted to around 45degC by chilling, if necessary to reduce shrinkage stresses and cracks. (M.G.B.)

  2. Radiation collimator for use with high energy radiation beams

    International Nuclear Information System (INIS)

    Malak, S.P.

    1978-01-01

    A collimator is described for use with a beam of radiation, and in particular, for use in controlling the cross-sectional size and shape of the radiation beam and intercepting undesired off-focus radiation in an x-ray apparatus. The collimator is positioned adjacent to the source of radiation and embodies a plurality longitudinally extending leaves pivotally mounted on and between two supports, the leaves move about their pivots to close overlapping relation to define a hollow cone. The cone defines an aperture at its narrow end which can be adjusted in size and shape by rotation of the two supports which are adaptable to being moved one relative to the other, to cause an expansion or contraction of the hollow cone and correspondingly an increase or decrease of the cross-sectional size and/or shape of the radiation beam passing through the aperture

  3. High-density amorphous ice: nucleation of nanosized low-density amorphous ice

    Science.gov (United States)

    Tonauer, Christina M.; Seidl-Nigsch, Markus; Loerting, Thomas

    2018-01-01

    The pressure dependence of the crystallization temperature of different forms of expanded high-density amorphous ice (eHDA) was scrutinized. Crystallization at pressures 0.05-0.30 GPa was followed using volumetry and powder x-ray diffraction. eHDA samples were prepared via isothermal decompression of very high-density amorphous ice at 140 K to different end pressures between 0.07-0.30 GPa (eHDA0.07-0.3). At 0.05-0.17 GPa the crystallization line T x (p) of all eHDA variants is the same. At pressures  >0.17 GPa, all eHDA samples decompressed to pressures  <0.20 GPa exhibit significantly lower T x values than eHDA0.2 and eHDA0.3. We rationalize our findings with the presence of nanoscaled low-density amorphous ice (LDA) seeds that nucleate in eHDA when it is decompressed to pressures  <0.20 GPa at 140 K. Below ~0.17 GPa, these nanosized LDA domains are latent within the HDA matrix, exhibiting no effect on T x of eHDA<0.2. Upon heating at pressures  ⩾0.17 GPa, these nanosized LDA nuclei transform to ice IX nuclei. They are favored sites for crystallization and, hence, lower T x . By comparing crystallization experiments of bulk LDA with the ones involving nanosized LDA we are able to estimate the Laplace pressure and radius of ~0.3-0.8 nm for the nanodomains of LDA. The nucleation of LDA in eHDA revealed here is evidence for the first-order-like nature of the HDA  →  LDA transition, supporting water’s liquid-liquid transition scenarios.

  4. High energy density Z-pinch plasmas using flow stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Shumlak, U., E-mail: shumlak@uw.edu; Golingo, R. P., E-mail: shumlak@uw.edu; Nelson, B. A., E-mail: shumlak@uw.edu; Bowers, C. A., E-mail: shumlak@uw.edu; Doty, S. A., E-mail: shumlak@uw.edu; Forbes, E. G., E-mail: shumlak@uw.edu; Hughes, M. C., E-mail: shumlak@uw.edu; Kim, B., E-mail: shumlak@uw.edu; Knecht, S. D., E-mail: shumlak@uw.edu; Lambert, K. K., E-mail: shumlak@uw.edu; Lowrie, W., E-mail: shumlak@uw.edu; Ross, M. P., E-mail: shumlak@uw.edu; Weed, J. R., E-mail: shumlak@uw.edu [Aerospace and Energetics Research Program, University of Washington, Seattle, Washington, 98195-2250 (United States)

    2014-12-15

    The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvén times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes – Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and

  5. High-density cervical ureaplasma urealyticum colonization in pregnant women

    Directory of Open Access Journals (Sweden)

    Ranđelović Gordana

    2006-01-01

    Full Text Available Background/aim: Ureaplasma urealyticum, a common commensal of the female lower genital tract, has been observed as an important opportunistic pathogen during pregnancy. The aims of this study were to determine the degree of cervical colonization with U. urealyticum in pregnant women with risk pregnancy and in pregnant women with normal term delivery and to evaluate the correlation between high-density cervical U. urealyticum colonization and premature rupture of membranes (PROM as well. Methods. This research was conducted on the samples comprising 130 hospitalized pregnant women with threatening preterm delivery and premature rupture of membranes. The control group consisted of 39 pregnant women with term delivery without PROM. In addition to standard bacteriological examination and performing direct immunofluorescence test to detect Chlamydia trachomatis, cervical swabs were also examined for the presence of U. urealyticum and Mycoplasma hominis by commercially available Mycofast Evolution 2 test (International Microbio, France. Results. The number of findings with isolated high-density U. urealyticum in the target group was 69 (53.08%, while in the control group was 14 (35.90%. Premature rupture of membranes (PROM occurred in 43 (33.08% examinees: 29 were pPROM, and 14 were PROM. The finding of U.urealyticum ≥104 was determined in 25 (58.14% pregnant women with rupture, 17 were pPROM, and 8 were PROM. There was statistically significant difference in the finding of high-density U. urealyticum between the pregnant women with PROM and the control group (χ² = 4.06, p < 0.05. U. urealyticum was predominant bacterial species found in 62.79% of isolates in the PROM cases, while in 32.56% it was isolated alone. Among the 49 pregnant women with preterm delivery, pPROM occurred in 29 (59.18% examinees, and in 70.83% of pregnant women with findings of high-density U. urealyticum pPROM was observed. Conclusion. Cervical colonization with U

  6. Cryogenic semiconductor high-intensity radiation monitors

    International Nuclear Information System (INIS)

    Palmieri, V.G.; Bell, W.H.; Borer, K.; Casagrande, L.; Da Via, C.; Devine, S.R.H.; Dezillie, B.; Esposito, A.; Granata, V.; Hauler, F.; Jungermann, L.; Li, Z.; Lourenco, C.; Niinikoski, T.O.; Shea, V. O'; Ruggiero, G.; Sonderegger, P.

    2003-01-01

    This paper describes a novel technique to monitor high-intensity particle beams by means of a semiconductor detector. It consists of cooling a semiconductor detector down to cryogenic temperature to suppress the thermally generated leakage current and to precisely measure the integrated ionization signal. It will be shown that such a device provides very good linearity and a dynamic range wider than is possible with existing techniques. Moreover, thanks to the Lazarus effect, extreme radiation hardness can be achieved providing in turn absolute intensity measurements against precise calibration of the device at low beam flux

  7. High power density reactors based on direct cooled particle beds

    Science.gov (United States)

    Powell, J. R.; Horn, F. L.

    Reactors based on direct cooled High Temperature Gas Cooled Reactor (HTGR) type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out along the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBRs) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed.

  8. The SLAC high-density gaseous polarized 3He target

    International Nuclear Information System (INIS)

    Johnson, J.R.; Chupp, T.E.; Smith, T.B.; Cates, G.D.; Driehuys, B.; Middleton, H.; Newbury, N.R.; Hughes, E.W.; Meyer, W.

    1995-01-01

    A large-scale high-pressure gaseous 3 He polarized target has been developed for use with a high-intensity polarized electron beam at the Stanford Linear Accelerator Center. This target was used successfully in an experiment to study the spin structure of the neutron. The target provided an areal density of about 7x10 21 nuclei/cm 2 and operated at 3 He polarizations between about 30% and 40% for the six-week duration of the experiment. ((orig.))

  9. Moderate energy ions for high energy density physics experiments

    International Nuclear Information System (INIS)

    Grisham, L.R.

    2004-01-01

    This paper gives the results of a preliminary exploration of whether moderate energy ions (≅0.3-3 MeV/amu) could be useful as modest-cost drivers for high energy density physics experiments. It is found that if the target thickness is chosen so that the ion beam enters and then leaves the target in the vicinity of the peak of the dE/dX (stopping power) curve, high uniformity of energy deposition may be achievable while also maximizing the amount of energy per beam particle deposited within the target

  10. High Density Thermal Energy Storage with Supercritical Fluids

    Science.gov (United States)

    Ganapathi, Gani B.; Wirz, Richard

    2012-01-01

    A novel approach to storing thermal energy with supercritical fluids is being investigated, which if successful, promises to transform the way thermal energy is captured and utilized. The use of supercritical fluids allows cost-affordable high-density storage with a combination of latent heat and sensible heat in the two-phase as well as the supercritical state. This technology will enhance penetration of several thermal power generation applications and high temperature water for commercial use if the overall cost of the technology can be demonstrated to be lower than the current state-of-the-art molten salt using sodium nitrate and potassium nitrate eutectic mixtures.

  11. High current density aluminum stabilized conductor concepts for space applications

    International Nuclear Information System (INIS)

    Huang, X.; Eyssa, Y.M.; Hilal, M.A.

    1989-01-01

    Lightweight conductors are needed for space magnets to achieve values of E/M (energy stored per unit mass) comparable to the or higher than advanced batteries. High purity aluminum stabilized NbTi composite conductors cooled by 1.8 K helium can provide a winding current density up to 15 kA/cm/sup 2/ at fields up to 10 tesla. The conductors are edge cooled with enough surface area to provide recovery following a normalizing disturbance. The conductors are designed so that current diffusion time in the high purity aluminum is smaller than thermal diffusion time in helium. Conductor design, stability and current diffusion are considered in detail

  12. Beam size measurement at high radiation levels

    International Nuclear Information System (INIS)

    Decker, F.J.

    1991-05-01

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

  13. X-ray spectroscopy for high energy-density X pinch density and temperature measurements (invited)

    International Nuclear Information System (INIS)

    Pikuz, S.A.; Shelkovenko, T.A.; Chandler, K.M.; Mitchell, M.D.; Hammer, D.A.; Skobelev, I.Y.; Shlyaptseva, A.S.; Hansen, S.B.

    2004-01-01

    X pinch plasmas produced from fine metal wires can reach near solid densities and temperatures of 1 keV or even more. Plasma conditions change on time scales as short as 5-10 ps as determined using an x-ray streak camera viewing a focusing crystal spectrograph or directly viewing the plasma through multiple filters on a single test. As a result, it is possible to determine plasma conditions from spectra with ∼10 ps time resolution. Experiments and theory are now coming together to give a consistent picture of the dynamics and kinetics of these high energy density plasmas with very high temporal and spatial precision. A set of diagnostic techniques used in experiments for spectrally, temporally, and spatially resolved measurements of X pinch plasmas is described. Results of plasma parameter determination from these measurements are presented. X ray backlighting of one x-pinch by another with ∼30 ps x-ray pulses enables the dynamics and kinetics to be correlated in time

  14. Manufacture of sintered bricks of high density from beryllium oxide

    International Nuclear Information System (INIS)

    Pointud, R.; Rispal, Ch.; Le Garec, M.

    1959-01-01

    Beryllium oxide bricks of nuclear purity 100 x 100 x 50 and 100 x 100 x 100 mm of very high density (between 2.85 and 3.00) are manufactured by sintering under pressure in graphite moulds at temperatures between 1,750 and 1,850 deg. C, and under a pressure of 150 kg/cm 2 . The physico-chemical state of the saw material is of considerable importance with regard to the success of the sintering operation. In addition, a study of the sintering of a BeO mixture with 3 to 5 per cent of boron introduced in the form of boric acid, boron carbide or elementary boron shows that high densities can only be obtained by sintering under pressure. For technical reasons of manufacture, only the mixture based on boron carbide is used. The sintering is carried out in graphite moulds at 1500 deg. C under 150 kg/cm 2 pressure, and bricks can be obtained with density between 2,85 and 2,90. Laboratory studies and the industrial manufacture of various sinters are described in detail. (author) [fr

  15. Inelastic neutron scattering from high-density fcc 4He

    International Nuclear Information System (INIS)

    Thomlinson, W.; Eckert, J.; Shirane, G.

    1978-01-01

    The phonon dispersion relations in high-density crystals of fcc 4 He have been measured along high-symmetry directions by the neutron-inelastic-scattering technique. A recent study of the lattice dynamics of fcc 4 He by Eckert et al. has been extended to cover the fcc phase diagram at pressures below 5 kbar. Molar volumes of 9.03, 9.43, and 9.97 cm 3 /mole have been studied in the temperature range from near the melting curve to near the fcc-hcp transition line. The phonon dispersion relations are in good agreement with a first-order self-consistent phonon theory calculation by Goldman. The observed phonon-group line shapes at large energy and momentum transfers show evidence for multiphonon scattering in agreement with calculations by Glyde. Eckert et al. reported extremely large anharmonic isochoric temperature shifts of the phonon energies. The present work studied the shifts as a function of molar volume and temperature. Mode-Grueneisen-parameter dispersion curves have been measured using the present data and earlier measurements at lower density in the fcc phase by Traylor et al. Macroscopic Grueneisen parameters have been calculated from the phonon density of states obtained from the data

  16. Parity dependence of the nuclear level density at high excitation

    International Nuclear Information System (INIS)

    Rao, B.V.; Agrawal, H.M.

    1995-01-01

    The basic underlying assumption ρ(l+1, J)=ρ(l, J) in the level density function ρ(U, J, π) has been checked on the basis of high quality data available on individual resonance parameters (E 0 , Γ n , J π ) for s- and p-wave neutrons in contrast to the earlier analysis where information about p-wave resonance parameters was meagre. The missing level estimator based on the partial integration over a Porter-Thomas distribution of neutron reduced widths and the Dyson-Mehta Δ 3 statistic for the level spacing have been used to ascertain that the s- and p-wave resonance level spacings D(0) and D(1) are not in error because of spurious and missing levels. The present work does not validate the tacit assumption ρ(l+1, J)=ρ(l, J) and confirms that the level density depends upon parity at high excitation. The possible implications of the parity dependence of the level density on the results of statistical model calculations of nuclear reaction cross sections as well as on pre-compound emission have been emphasized. (orig.)

  17. High-Density Stretchable Electrode Grids for Chronic Neural Recording.

    Science.gov (United States)

    Tybrandt, Klas; Khodagholy, Dion; Dielacher, Bernd; Stauffer, Flurin; Renz, Aline F; Buzsáki, György; Vörös, János

    2018-04-01

    Electrical interfacing with neural tissue is key to advancing diagnosis and therapies for neurological disorders, as well as providing detailed information about neural signals. A challenge for creating long-term stable interfaces between electronics and neural tissue is the huge mechanical mismatch between the systems. So far, materials and fabrication processes have restricted the development of soft electrode grids able to combine high performance, long-term stability, and high electrode density, aspects all essential for neural interfacing. Here, this challenge is addressed by developing a soft, high-density, stretchable electrode grid based on an inert, high-performance composite material comprising gold-coated titanium dioxide nanowires embedded in a silicone matrix. The developed grid can resolve high spatiotemporal neural signals from the surface of the cortex in freely moving rats with stable neural recording quality and preserved electrode signal coherence during 3 months of implantation. Due to its flexible and stretchable nature, it is possible to minimize the size of the craniotomy required for placement, further reducing the level of invasiveness. The material and device technology presented herein have potential for a wide range of emerging biomedical applications. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. High-energy density physics at Los Alamos

    International Nuclear Information System (INIS)

    Byrnes, P.; Younger, S.M.

    1993-03-01

    This brochure describes the facilities of the Above Ground Experiments II (AGEX II) and the Inertial Confinement Fusion (ICF) programs at Los Alamo. Combined, these programs represent, an unparalleled capability to address important issues in high-energy density physics that are critical to the future defense, energy, and research needs of th e United States. The mission of the AGEX II program at Los Alamos is to provide additional experimental opportunities for the nuclear weapons program. For this purpose we have assembled at Los Alamos the broadest array of high-energy density physics facilities of any laboratory in the world. Inertial confinement fusion seeks to achieve thermonuclear burn on a laboratory scale through the implosion of a small quantity of deuterium and tritium fuel to very high Pressure and temperature.The Los Alamos ICF program is focused on target physics. With the largest scientific computing center in the world, We can perform calculations of unprecedented sophistication and precision. We field experiments at facilities worldwide-including our own Trident and Mercury lasers-to confirm our understanding and to provide the necessary data base to proceed toward the historic goal of controlled fusion in the laboratory. In addition to direct programmatic high-energy density physics is a nc scientific endeavor in itself. The ultrahigh magnetic fields produced in our high explosive pulsed-power generators can be used in awide variety of solid state physics and temperature superconductor studies. The structure and dynamics of planetary atmospheres can be simulated through the compression of gas mixtures

  19. Ducting of the Whistler-Mode Waves by Magnetic Field-Aligned Density Enhancements in the Radiation Belt

    Science.gov (United States)

    Streltsov, A. V.; Bengtson, M.; English, D.; Miller, M.; Turco, L.

    2017-12-01

    Whistler-mode waves (or whistlers) are the right-hand polarized electromagnetic waves with a frequency in the range above the lower hybrid frequency and below the electron cyclotron frequency. They can efficiently interact with energetic electrons in the equatorial magnetosphere and remediate them from the earth's radiation belt. These interactions are non-linear, they depend on the wave amplitude, and for them to be efficient the wave power needs to be delivered from the transmitter to the interaction region without significant losses. The main physical mechanism which can solve this problem is ducting/guiding of whistlers by magnetic field-aligned density inhomogeneities or ducts. We present results from a modeling of whistler-mode waves observed by the NASA Van Allen Probes satellites inside the ducts formed by density enhancements (also known as, high-density ducts or HDD). Our previous studies suggest that HDD can confine without leakage only waves with some particular parameters (frequency, perpendicular and parallel wavelength) connected with the parameters of the duct (like duct's "width" and "depth"). Our numerical results confirm that 1) the high-density ducts with amplitudes and perpendicular sizes observed by the RBSP satellites can indeed guide whistlers over significant distances along the ambient magnetic field with small leakage, and 2) the quality of the ducting indeed depends on the wave perpendicular and parallel wavelengths and, therefore, the fact that the wave is ducted by HDD can be used to determine parameters of the wave.

  20. Dust acoustic shock wave at high dust density

    International Nuclear Information System (INIS)

    Ghosh, Samiran; Sarkar, Susmita; Khan, Manoranjan; Avinash, K.; Gupta, M. R.

    2003-01-01

    Dust acoustic (DA) shock wave at high dust density, i.e., the dust electroacoustic (DEA) or dust Coulomb (DC) shock wave has been investigated incorporating the nonadiabatic dust charge variation. The nonlinear DEA (DC) shock wave is seen to be governed by the Korteweg-de Vries Burger equation, in which the Burger term is proportional to the nonadiabaticity generated dissipation. It is seen that the shock strength decreases but after reaching minimum, it increases as the dust space charge density |q d n d | increases and the shock strength of DA wave is greater than that of DEA (DC) wave. Moreover the DEA (DC) shock width increases appreciably with increase mass m i of the ion component of the dusty plasma but for DA shock wave the effect is weak

  1. High-Density Lipoproteins and the Immune System

    Directory of Open Access Journals (Sweden)

    Hidesuke Kaji

    2013-01-01

    Full Text Available High-density lipoprotein (HDL plays a major role in vasodilation and in the reduction of low-density lipoprotein (LDL oxidation, inflammation, apoptosis, thrombosis, and infection; however, HDL is now less functional in these roles under certain conditions. This paper focuses on HDL, its anti-inflammation behavior, and the mechanisms by which HDL interacts with components of the innate and adaptive immune systems. Genome-wide association studies (GWAS and proteomic studies have elucidated important molecules involved in the interaction between HDL and the immune system. An understanding of these mechanisms is expected to be useful for the prevention and treatment of chronic inflammation due to metabolic syndrome, atherosclerosis, or various autoimmune diseases.

  2. Reaction of unirradiated high-density fuel with aluminum

    International Nuclear Information System (INIS)

    Wiencek, T.C.; Meyer, M.K.; Prokofiev, I.G.; Keiser, D.D.

    1997-01-01

    Excellent dispersion fuel performance requires that fuel particles remain stable and do not react significantly with the surrounding aluminum matrix. A series of high-density fuels, which contain uranium densities >12 g/cm 3 , have been fabricated into plates. As part of standard processing, all of these fuels were subjected to a blister anneal of 1 h at 485 deg. C. Changes in plate thickness were measured and evaluated. From these results, suppositions about the probable irradiation properties of these fuels have been proposed. In addition, two fuels, U-10 wt% Mo and U 2 Mo, were subjected to various heat treatments and were found to be very stable in an aluminum matrix. On the basis of the experimental data, hypotheses of the irradiation behavior of these fuels are presented. (author)

  3. High-Density Near-Field Optical Disc Recording

    Science.gov (United States)

    Shinoda, Masataka; Saito, Kimihiro; Ishimoto, Tsutomu; Kondo, Takao; Nakaoki, Ariyoshi; Ide, Naoki; Furuki, Motohiro; Takeda, Minoru; Akiyama, Yuji; Shimouma, Takashi; Yamamoto, Masanobu

    2005-05-01

    We developed a high-density near-field optical recording disc system using a solid immersion lens. The near-field optical pick-up consists of a solid immersion lens with a numerical aperture of 1.84. The laser wavelength for recording is 405 nm. In order to realize the near-field optical recording disc, we used a phase-change recording media and a molded polycarbonate substrate. A clear eye pattern of 112 GB capacity with 160 nm track pitch and 50 nm bit length was observed. The equivalent areal density is 80.6 Gbit/in2. The bottom bit error rate of 3 tracks-write was 4.5× 10-5. The readout power margin and the recording power margin were ± 30.4% and ± 11.2%, respectively.

  4. High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

    International Nuclear Information System (INIS)

    Ping, Mao; Zhi-Gang, Zhang; Li-Yang, Pan; Jun, Xu; Pei-Yi, Chen

    2009-01-01

    Stacked ruthenium (Ru) nanocrystals (NCs) are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density (3 × 10 12 cm −2 ), small size (2–4 nm) and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs

  5. Physical and clinical evaluation of new high-strip-density radiographic grids

    International Nuclear Information System (INIS)

    Doi, K.; Frank, P.H.; Chan, H.P.; Vyborny, C.J.; Makino, S.; Iida, N.; Carlin, M.

    1983-01-01

    The imaging performance of new high-strip-density (HSD) grids having 57 lines/cm was compared with that of conventional low-strip-density (LSD) grids having 33 or 40 lines/cm. The unique advantage of HSD grids is that, under most standard radiographic conditions, the grid lines are not noticeable on the final image, even if the grid is stationary. This is due to the combined effect of the high fundamental spatial frequency of HSD grids, the modulation transfer function of screen-film systems and of the human visual system, and scattered radiation. Monte Carlo simulation studies, phantom images, and clinical evaluation indicate that HSD grids can provide contrast improvement factors and Bucky factors that are comparable to or slightly better than those obtained with LSD grids. Therefore, it may now be possible to eliminate moving Bucky trays from radiographic tables and fluoroscopic devices

  6. Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

    Science.gov (United States)

    Li, Jianlin; Du, Zhijia; Ruther, Rose E.; AN, Seong Jin; David, Lamuel Abraham; Hays, Kevin; Wood, Marissa; Phillip, Nathan D.; Sheng, Yangping; Mao, Chengyu; Kalnaus, Sergiy; Daniel, Claus; Wood, David L.

    2017-09-01

    Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by 70% from 2008 to 2015, the current battery pack cost (268/kWh in 2015) is still >2 times what the USABC targets (125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. This article discusses three major aspects for cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.

  7. High power density reactors based on direct cooled particle beds

    International Nuclear Information System (INIS)

    Powell, J.R.; Horn, F.L.

    1985-01-01

    Reactors based on direct cooled HTGR type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out long the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBR's) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed. 12 figs

  8. Microelectromechanical high-density energy storage/rapid release system

    Science.gov (United States)

    Rodgers, M. Steven; Allen, James J.; Meeks, Kent D.; Jensen, Brian D.; Miller, Samuel L.

    1999-08-01

    One highly desirable characteristic of electrostatically driven microelectromechanical systems (MEMS) is that they consume very little power. The corresponding drawback is that the force they produce may be inadequate for many applications. It has previously been demonstrated that gear reduction units or microtransmissions can substantially increase the torque generated by microengines. Operating speed, however, is also reduced by the transmission gear ratio. Some applications require both high speed and high force. If this output is only required for a limited period of time, then energy could be stored in a mechanical system and rapidly released upon demand. We have designed, fabricated, and demonstrated a high-density energy storage/rapid release system that accomplishes this task. Built using a 5-level surface micromachining technology, the assembly closely resembles a medieval crossbow. Energy releases on the order of tens of nanojoules have already been demonstrated, and significantly higher energy systems are under development.

  9. The high density and high βpol disruption mechanism on TFTR

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; Manickam, J.; McGuire, K.M.; Monticello, D.; Nagayama, Y.; Park, W.; Taylor, G.

    1992-01-01

    Studies of disruptions on TFTR have been extended to include high density disruptions as well as the high β pol disruptions. The data strongly suggests that the (m,n)=(1,1) mode plays an important role in both types of disruptions. Further, for the first time, it is unambiguously shown, using a fast electron cyclotron emission (ECE) instrument for the electron temperature profile measurements, that the (m,n)=(1,1) precursor to the high density disruptions has a 'cold bubble' structure. The precursor to the major disruption at high density resembles the 'vacuum bubble' model of disruptions first proposed by Kadomtsev and Pogutse. (author) 2 refs., 2 figs

  10. Renewable carbohydrates are a potential high-density hydrogen carrier

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.-H. Percival [Biological Systems Engineering Department, 210-A Seitz Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Institute for Critical Technology and Applied Sciences (ICTAS), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); DOE BioEnergy Science Center (BESC), Oak Ridge, TN 37831 (United States)

    2010-10-15

    The possibility of using renewable biomass carbohydrates as a potential high-density hydrogen carrier is discussed here. Gravimetric density of polysaccharides is 14.8 H{sub 2} mass% where water can be recycled from PEM fuel cells or 8.33% H{sub 2} mass% without water recycling; volumetric densities of polysaccharides are >100 kg of H{sup 2}/m{sup 3}. Renewable carbohydrates (e.g., cellulosic materials and starch) are less expensive based on GJ than are other hydrogen carriers, such as hydrocarbons, biodiesel, methanol, ethanol, and ammonia. Biotransformation of carbohydrates to hydrogen by cell-free synthetic (enzymatic) pathway biotransformation (SyPaB) has numerous advantages, such as high product yield (12 H{sub 2}/glucose unit), 100% selectivity, high energy conversion efficiency (122%, based on combustion energy), high-purity hydrogen generated, mild reaction conditions, low-cost of bioreactor, few safety concerns, and nearly no toxicity hazards. Although SyPaB may suffer from current low reaction rates, numerous approaches for accelerating hydrogen production rates are proposed and discussed. Potential applications of carbohydrate-based hydrogen/electricity generation would include hydrogen bioreactors, home-size electricity generators, sugar batteries for portable electronics, sugar-powered passenger vehicles, and so on. Developments in thermostable enzymes as standardized building blocks for cell-free SyPaB projects, use of stable and low-cost biomimetic NAD cofactors, and accelerating reaction rates are among the top research and development priorities. International collaborations are urgently needed to solve the above obstacles within a short time. (author)

  11. Ultra-Stretchable Interconnects for High-Density Stretchable Electronics

    Directory of Open Access Journals (Sweden)

    Salman Shafqat

    2017-09-01

    Full Text Available The exciting field of stretchable electronics (SE promises numerous novel applications, particularly in-body and medical diagnostics devices. However, future advanced SE miniature devices will require high-density, extremely stretchable interconnects with micron-scale footprints, which calls for proven standardized (complementary metal-oxide semiconductor (CMOS-type process recipes using bulk integrated circuit (IC microfabrication tools and fine-pitch photolithography patterning. Here, we address this combined challenge of microfabrication with extreme stretchability for high-density SE devices by introducing CMOS-enabled, free-standing, miniaturized interconnect structures that fully exploit their 3D kinematic freedom through an interplay of buckling, torsion, and bending to maximize stretchability. Integration with standard CMOS-type batch processing is assured by utilizing the Flex-to-Rigid (F2R post-processing technology to make the back-end-of-line interconnect structures free-standing, thus enabling the routine microfabrication of highly-stretchable interconnects. The performance and reproducibility of these free-standing structures is promising: an elastic stretch beyond 2000% and ultimate (plastic stretch beyond 3000%, with <0.3% resistance change, and >10 million cycles at 1000% stretch with <1% resistance change. This generic technology provides a new route to exciting highly-stretchable miniature devices.

  12. Physiological and genetics studies of highly radiation-resistant bacteria

    International Nuclear Information System (INIS)

    Keller, L.C.

    1981-01-01

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

  13. UVB-induced photoperoxidation of lipids of human low and high density lipoproteins. A possible role of tryptophan residues

    International Nuclear Information System (INIS)

    Salmon, S.; Maziere, J.C.; Santus, R.; Bouchemal, N.; Morliere, P.

    1990-01-01

    Ultraviolet radiation of the UVB region readily destroys tryptophan (Trp) residues of low (LDL) and high (HDL) density lipoproteins. The photooxidation of tryptophan residues is accompanied by peroxidation of low and high density lipoproteins unsaturated fatty acids, as measured by thiobarbituric acid assay. Moreover, low and high density lipoproteins are natural carriers of vitamin E and carotenoids. These two antioxidants are also rapidly bleached by UVB. The UVA radiation promotes neither tryptophan residue destruction nor lipid photoperoxidation. The redox cycling Cu 2+ ions considerably increase lipid photoperoxidation. The synergistic action of photo and auto (Cu 2+ -induced) peroxidation induces marked post-irradiation modifications of apolipoproteins as illustrated by degradation of most tryptophan residues after overnight incubation in the dark of pre-irradiated samples. (author)

  14. Experimental microdosimetry in high energy radiation fields

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  15. Effect of low-power density laser radiation on heatling of open skin wounds in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kana, J.S.; Hutschenreiter, G.; Haina, D.; Waidelich, W.

    1981-03-01

    Researchers performed a study to determine whether laser radation of low-power density would affect the healing of open skin wounds in rats. The wounds were irradiated daily with a helium-neon laser and an argon laser at a constant power density of 45 mW/sq cm. The rate of wound closure was followed by photographing the wounds in a standardized way. The collagen hydroxyproline concentration in the scar tissue was determined on the 18th postoperative day. Helium-neon laser radiation had a statistically significant stimulating effect on collagen synthesis in the wound, with a maximum effect at an energy density of 4 joules/sq cm. The rate of wound closure was enhanced significantly between the third and 12th postoperative days. The argon laser exposure produced a significant increase in collagen concentration both in irradiated and nonirradiated contralateral wounds. However, an acceleration of the healing rate was not registered in this case. The wound contraction up to the fourth day of the experiment was inhibited under helium-neon and argon laser exposure to 20 joules/sq cm. The described effects were not specific for the laser light. There may be a wavelength-selective influence of coherent light on the metabolic and proliferation processes in wound healing, with the associated problem of the possible carcinogenic effects of laser radiation.

  16. Microfluidic engineered high cell density three-dimensional neural cultures

    Science.gov (United States)

    Cullen, D. Kacy; Vukasinovic, Jelena; Glezer, Ari; La Placa, Michelle C.

    2007-06-01

    Three-dimensional (3D) neural cultures with cells distributed throughout a thick, bioactive protein scaffold may better represent neurobiological phenomena than planar correlates lacking matrix support. Neural cells in vivo interact within a complex, multicellular environment with tightly coupled 3D cell-cell/cell-matrix interactions; however, thick 3D neural cultures at cell densities approaching that of brain rapidly decay, presumably due to diffusion limited interstitial mass transport. To address this issue, we have developed a novel perfusion platform that utilizes forced intercellular convection to enhance mass transport. First, we demonstrated that in thick (>500 µm) 3D neural cultures supported by passive diffusion, cell densities =104 cells mm-3), continuous medium perfusion at 2.0-11.0 µL min-1 improved viability compared to non-perfused cultures (p death and matrix degradation. In perfused cultures, survival was dependent on proximity to the perfusion source at 2.00-6.25 µL min-1 (p 90% viability in both neuronal cultures and neuronal-astrocytic co-cultures. This work demonstrates the utility of forced interstitial convection in improving the survival of high cell density 3D engineered neural constructs and may aid in the development of novel tissue-engineered systems reconstituting 3D cell-cell/cell-matrix interactions.

  17. Interaction of Repetitively Pulsed High Energy Laser Radiation With Matter

    Science.gov (United States)

    Hugenschmidt, Manfred

    1986-10-01

    The paper is concerned with laser target interaction processes involving new methods of improving the overall energy balance. As expected theoretically, this can be achieved with high repetition rate pulsed lasers even for initially highly reflecting materials, such as metals. Experiments were performed by using a pulsed CO2 laser at mean powers up to 2 kW and repetition rates up to 100 Hz. The rates of temperature rise of aluminium for example were thereby increased by lore than a factor of 3 as compared to cw-radiation of comparable power density. Similar improvements were found for the overall absorptivities that were increased by this method by more than an order of magnitude.

  18. High density microelectronics package using low temperature cofirable ceramics

    International Nuclear Information System (INIS)

    Fu, S.-L.; Hsi, C.-S.; Chen, L.-S.; Lin, W. K.

    1997-01-01

    Low Temperature Cofired Ceramics (LTCC) is a relative new thick film process and has many engineering and manufacturing advantages over both the sequential thick film process and high temperature cofired ceramic modules. Because of low firing temperature, low sheet resistance metal conductors, commercial thick film resistors, and thick film capacitors can be buried in or printed on the substrates. A 3-D multilayer ceramic substrate can be prepared via laminating and co-firing process. The packing density of the LTCC substrates can be increased by this 3-D packing technology. At Kaohsiung Polytechnic Institute (KPI), a LTCC substrate system has been developed for high density packaging applications, which had buried surface capacitors and resistors. The developed cordierite-glass ceramic substrate, which has similar thermal expansion as silicon chip, is a promising material for microelectronic packaging. When the substrates were sintered at temperatures between 850-900 degree centigrade, a relative density higher than 96 % can be obtained. The substrate had a dielectric constant between 5.5 and 6.5. Ruthenium-based resistor pastes were used for resistors purposes. The resistors fabricated in/on the LTCC substrates were strongly depended on the microstructures developed in the resistor films. Surface resistors were laser trimmed in order to obtain specific values for the resistors. Material with composition Pb(Fe 2/3 W 1/3 ) x (Fe l/2 Nb l/2 ) y Ti 2 O 3 was used as dielectric material of the capacitor in the substrate. The material can be sintered at temperatures between 850-930 degree centigrade, and has dielectric constant as high as 26000. After cofiring, good adhesion between dielectric and substrate layers was obtained. Combing the buried resistors and capacitors together with the lamination of LTCC layer, a 3-dimensional multilayered ceramic package was fabricated. (author)

  19. High density microelectronics package using low temperature cofirable ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Fu, S -L; Hsi, C -S; Chen, L -S; Lin, W K [Kaoshiung Polytechnic Institute Ta-Hsu, Kaoshiung (China)

    1998-12-31

    Low Temperature Cofired Ceramics (LTCC) is a relative new thick film process and has many engineering and manufacturing advantages over both the sequential thick film process and high temperature cofired ceramic modules. Because of low firing temperature, low sheet resistance metal conductors, commercial thick film resistors, and thick film capacitors can be buried in or printed on the substrates. A 3-D multilayer ceramic substrate can be prepared via laminating and co-firing process. The packing density of the LTCC substrates can be increased by this 3-D packing technology. At Kaohsiung Polytechnic Institute (KPI), a LTCC substrate system has been developed for high density packaging applications, which had buried surface capacitors and resistors. The developed cordierite-glass ceramic substrate, which has similar thermal expansion as silicon chip, is a promising material for microelectronic packaging. When the substrates were sintered at temperatures between 850-900 degree centigrade, a relative density higher than 96 % can be obtained. The substrate had a dielectric constant between 5.5 and 6.5. Ruthenium-based resistor pastes were used for resistors purposes. The resistors fabricated in/on the LTCC substrates were strongly depended on the microstructures developed in the resistor films. Surface resistors were laser trimmed in order to obtain specific values for the resistors. Material with composition Pb(Fe{sub 2/3}W{sub 1/3}){sub x}(Fe{sub l/2}Nb{sub l/2}){sub y}Ti{sub 2}O{sub 3} was used as dielectric material of the capacitor in the substrate. The material can be sintered at temperatures between 850-930 degree centigrade, and has dielectric constant as high as 26000. After cofiring, good adhesion between dielectric and substrate layers was obtained. Combing the buried resistors and capacitors together with the lamination of LTCC layer, a 3-dimensional multilayered ceramic package was fabricated. (author)

  20. The glass transition in high-density amorphous ice.

    Science.gov (United States)

    Loerting, Thomas; Fuentes-Landete, Violeta; Handle, Philip H; Seidl, Markus; Amann-Winkel, Katrin; Gainaru, Catalin; Böhmer, Roland

    2015-01-01

    There has been a long controversy regarding the glass transition in low-density amorphous ice (LDA). The central question is whether or not it transforms to an ultraviscous liquid state above 136 K at ambient pressure prior to crystallization. Currently, the most widespread interpretation of the experimental findings is in terms of a transformation to a superstrong liquid above 136 K. In the last decade some work has also been devoted to the study of the glass transition in high-density amorphous ice (HDA) which is in the focus of the present review. At ambient pressure HDA is metastable against both ice I and LDA, whereas at > 0.2 GPa HDA is no longer metastable against LDA, but merely against high-pressure forms of crystalline ice. The first experimental observation interpreted as the glass transition of HDA was made using in situ methods by Mishima, who reported a glass transition temperature T g of 160 K at 0.40 GPa. Soon thereafter Andersson and Inaba reported a much lower glass transition temperature of 122 K at 1.0 GPa. Based on the pressure dependence of HDA's T g measured in Innsbruck, we suggest that they were in fact probing the distinct glass transition of very high-density amorphous ice (VHDA). Very recently the glass transition in HDA was also observed at ambient pressure at 116 K. That is, LDA and HDA show two distinct glass transitions, clearly separated by about 20 K at ambient pressure. In summary, this suggests that three glass transition lines can be defined in the p-T plane for LDA, HDA, and VHDA.

  1. Effects of gel composition on the radiation induced density change in PAG polymer gel dosimeters: a model and experimental investigations

    International Nuclear Information System (INIS)

    Hilts, M; Jirasek, A; Duzenli, C

    2004-01-01

    Due to a density change that occurs in irradiated polyacrylamide gel (PAG), x-ray computed tomography (CT) has emerged as a feasible method of performing polymer gel dosimetry. However, applicability of the technique is currently limited by low sensitivity of the density change to dose. This work investigates the effect of PAG composition on the radiation induced density change and provides direction for future work in improving the sensitivity of CT polymer gel dosimetry. A model is developed that describes the PAG density change (Δρ gel ) as a function of both polymer yield (%P) and an intrinsic density change, per unit polymer yield, that occurs on conversion of monomer to polymer (Δρ polymer ). %P is a function of the fraction of monomer consumed and the weight fraction of monomer in the unirradiated gel (%T). Applying the model to experimental CT and Raman spectroscopic data, two important fundamental properties of the response of PAG density to dose (Δρ gel dose response) are discovered. The first property is that Δρ polymer depends on PAG %C (cross-linking fraction of total monomer) such that low and high %C PAGs exhibit a higher Δρ polymer than do more intermediate %C PAGs. This relationship is opposite to the relationship of polymer yield to %C and is explained by the effect of %C on the type of polymer formed. The second property is that the Δρ gel dose response is linearly dependent on %T. From the model, the inference is that, at least for %T≤12%, monomer consumption and Δρ polymer depend solely on %C. In terms of optimizing CT polymer gel dosimetry for high sensitivity, these results indicate that Δρ polymer can be expected to vary with each polymer gel system and thus should be considered when choosing a polymer gel for CT gel dosimetry. However, Δρ polymer and %P cannot be maximized simultaneously and maximizing %P, by choosing gels with intermediate %C and high %T, is found to have the greatest impact on increasing the

  2. Interfacial Tension and Surface Pressure of High Density Lipoprotein, Low Density Lipoprotein, and Related Lipid Droplets

    DEFF Research Database (Denmark)

    Ollila, O. H. S.; Lamberg, A.; Lehtivaara, M.

    2012-01-01

    ) are essentially lipid droplets surrounded by specific proteins, their main function being to transport cholesterol. Interfacial tension and surface pressure of these particles are of great interest because they are related to the shape and the stability of the droplets and to protein adsorption at the interface....... Here we use coarse-grained molecular-dynamics simulations to consider a number of related issues by calculating the interfacial tension in protein-free lipid droplets, and in HDL and LDL particles mimicking physiological conditions. First, our results suggest that the curvature dependence......Lipid droplets play a central role in energy storage and metabolism on a cellular scale. Their core is comprised of hydrophobic lipids covered by a surface region consisting of amphiphilic lipids and proteins. For example, high and low density lipoproteins (HDL and LDL, respectively...

  3. Ultrathin Coaxial Fiber Supercapacitors Achieving High Energy and Power Densities.

    Science.gov (United States)

    Shen, Caiwei; Xie, Yingxi; Sanghadasa, Mohan; Tang, Yong; Lu, Longsheng; Lin, Liwei

    2017-11-15

    Fiber-based supercapacitors have attracted significant interests because of their potential applications in wearable electronics. Although much progress has been made in recent years, the energy and power densities, mechanical strength, and flexibility of such devices are still in need of improvement for practical applications. Here, we demonstrate an ultrathin microcoaxial fiber supercapacitor (μCFSC) with high energy and power densities (2.7 mW h/cm 3 and 13 W/cm 3 ), as well as excellent mechanical properties. The prototype with the smallest reported overall diameter (∼13 μm) is fabricated by successive coating of functional layers onto a single micro-carbon-fiber via a scalable process. Combining the simulation results via the electrochemical model, we attribute the high performance to the well-controlled thin coatings that make full use of the electrode materials and minimize the ion transport path between electrodes. Moreover, the μCFSC features high bending flexibility and large tensile strength (more than 1 GPa), which make it promising as a building block for various flexible energy storage applications.

  4. [Residual risk: The roles of triglycerides and high density lipoproteins].

    Science.gov (United States)

    Grammer, Tanja; Kleber, Marcus; Silbernagel, Günther; Scharnagl, Hubert; März, Winfried

    2016-06-01

    In clinical trials, the reduction of LDL-cholesterol (LDL-C) with statins reduces the incidence rate of cardiovascular events by approximately one third. This means, that a sizeable "residual risk" remains. Besides high lipoprotein (a), disorders in the metabolism of triglyceride-rich lipoproteins and high density liproteins have been implicated as effectors of the residual risk. Both lipoprotein parameters correlate inversely with each other. Therefore, the etiological contributions of triglycerides and / or of HDL for developing cardiovascular disease can hardly be estimated from either observational studies or from intervention studies. The largely disappointing results of intervention studies with inhibitors of the cholesteryl ester transfer protein and in particular the available set of genetically-epidemiological studies suggest that in the last decade, the importance of HDL cholesterol has been overvalued, while the importance of triglycerides has been underestimated. High triglycerides not always atherogenic, but only if they are associated with the accumulation relatively cholesterol-enriched, incompletely catabolized remnants of chylomicrons and very low density lipoproteins (familial type III hyperlipidemia, metabolic syndrome, diabetes mellitus). The normalization of the concentration of triglycerides and remnants by inhibiting the expression of apolipoprotein C3 is hence a new, promising therapeutic target. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Nonlinear transport in semiconducting polymers at high carrier densities.

    Science.gov (United States)

    Yuen, Jonathan D; Menon, Reghu; Coates, Nelson E; Namdas, Ebinazar B; Cho, Shinuk; Hannahs, Scott T; Moses, Daniel; Heeger, Alan J

    2009-07-01

    Conducting and semiconducting polymers are important materials in the development of printed, flexible, large-area electronics such as flat-panel displays and photovoltaic cells. There has been rapid progress in developing conjugated polymers with high transport mobility required for high-performance field-effect transistors (FETs), beginning with mobilities around 10(-4) cm(2) V(-1) s(-1) to a recent report of 1 cm(2) V(-1) s(-1) for poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT). Here, the electrical properties of PBTTT are studied at high charge densities both as the semiconductor layer in FETs and in electrochemically doped films to determine the transport mechanism. We show that data obtained using a wide range of parameters (temperature, gate-induced carrier density, source-drain voltage and doping level) scale onto the universal curve predicted for transport in the Luttinger liquid description of the one-dimensional 'metal'.

  6. Metal hydrides based high energy density thermal battery

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhigang Zak, E-mail: zak.fang@utah.edu [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Zhou, Chengshang; Fan, Peng [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Udell, Kent S. [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States); Bowman, Robert C. [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Vajo, John J.; Purewal, Justin J. [HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA 90265 (United States); Kekelia, Bidzina [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States)

    2015-10-05

    Highlights: • The principle of the thermal battery using advanced metal hydrides was demonstrated. • The thermal battery used MgH{sub 2} and TiMnV as a working pair. • High energy density can be achieved by the use of MgH{sub 2} to store thermal energy. - Abstract: A concept of thermal battery based on advanced metal hydrides was studied for heating and cooling of cabins in electric vehicles. The system utilized a pair of thermodynamically matched metal hydrides as energy storage media. The pair of hydrides that was identified and developed was: (1) catalyzed MgH{sub 2} as the high temperature hydride material, due to its high energy density and enhanced kinetics; and (2) TiV{sub 0.62}Mn{sub 1.5} alloy as the matching low temperature hydride. Further, a proof-of-concept prototype was built and tested, demonstrating the potential of the system as HVAC for transportation vehicles.

  7. Biomimetic High Density Lipoprotein Nanoparticles For Nucleic Acid Delivery

    Science.gov (United States)

    McMahon, Kaylin M.; Mutharasan, R. Kannan; Tripathy, Sushant; Veliceasa, Dorina; Bobeica, Mariana; Shumaker, Dale K.; Luthi, Andrea J.; Helfand, Brian T.; Ardehali, Hossein; Mirkin, Chad A.; Volpert, Olga; Thaxton, C. Shad

    2014-01-01

    We report a gold nanoparticle-templated high density lipoprotein (HDL AuNP) platform for gene therapy which combines lipid-based nucleic acid transfection strategies with HDL biomimicry. For proof-of-concept, HDL AuNPs are shown to adsorb antisense cholesterylated DNA. The conjugates are internalized by human cells, can be tracked within cells using transmission electron microscopy (TEM), and regulate target gene expression. Overall, the ability to directly image the AuNP core within cells, the chemical tailorability of the HDL AuNP platform, and the potential for cell-specific targeting afforded by HDL biomimicry make this platform appealing for nucleic acid delivery. PMID:21319839

  8. Optically Addressed Nanostructures for High Density Data Storage

    Science.gov (United States)

    2005-10-14

    beam to sub-wavelength resolutions. X. Refereed Journal Publications I. M. D. Stenner , D. J. Gauthier, and M. A. Neifeld, "The speed of information in a...profiles for high-density optical data storage," Optics Communications, Vol.253, pp.56-69, 2005. 5. M. D. Stenner , D. J. Gauthier, and M. A. Neifeld, "Fast...causal information transmission in a medium with a slow group velocity," Physical Review Letters, Vol.94, February 2005. 6. M. D. Stenner , M. A

  9. Viscosity and attenuation of sound wave in high density deuterium

    International Nuclear Information System (INIS)

    Inoue, Kazuko; Ariyasu, Tomio

    1985-01-01

    The penetration of low frequency sound wave into the fuel deuterium is discussed as for laser fusion. The sound velocity and the attenuation constant due to viscosity are calculated for high density (n = 10 24 -- 10 27 cm -3 , T = 10 -1 -- 10 4 eV) deuterium. The shear viscosity of free electron gas and the bulk viscosity due to ion-ion interaction mainly contribute to the attenuation of sound wave. The sound wave of the frequency below 10 10 Hz can easily penetrate through the compressed fuel deuterium of diameter 1 -- 10 3 μm. (author)

  10. On high-order perturbative calculations at finite density

    CERN Document Server

    Ghisoiu, Ioan; Kurkela, Aleksi; Romatschke, Paul; Säppi, Matias; Vuorinen, Aleksi

    2017-01-01

    We discuss the prospects of performing high-order perturbative calculations in systems characterized by a vanishing temperature but finite density. In particular, we show that the determination of generic Feynman integrals containing fermionic chemical potentials can be reduced to the evaluation of three-dimensional phase space integrals over vacuum on-shell amplitudes. Applications of these rules will be discussed in the context of the thermodynamics of cold and dense QCD, where it is argued that they facilitate an extension of the Equation of State of cold quark matter to higher perturbative orders.

  11. Electromagnetic-implosion generation of pulsed high energy density plasma

    International Nuclear Information System (INIS)

    Baker, W.L.; Broderick, N.F.; Degnan, J.H.; Hussey, T.W.; Kiuttu, G.F.; Kloc, D.A.; Reinovsky, R.E.

    1983-01-01

    This chapter reports on the experimental and theoretical investigation of the generation of pulsed high-energy-density plasmas by electromagnetic implosion of cylindrical foils (i.e., imploding liners or hollow Z-pinches) at the Air Force Weapons Laboratory. Presents a comparison of experimental data with one-dimensional MHD and two-dimensional calculations. Points out that the study is distinct from other imploding liner efforts in that the approach is to produce a hot, dense plasma from the imploded liner itself, rather than to compress a magnetic-field-performed plasma mixture. The goal is to produce an intense laboratory pulsed X-ray source

  12. Method for providing a low density high strength polyurethane foam

    Science.gov (United States)

    Whinnery, Jr., Leroy L.; Goods, Steven H.; Skala, Dawn M.; Henderson, Craig C.; Keifer, Patrick N.

    2013-06-18

    Disclosed is a method for making a polyurethane closed-cell foam material exhibiting a bulk density below 4 lbs/ft.sup.3 and high strength. The present embodiment uses the reaction product of a modified MDI and a sucrose/glycerine based polyether polyol resin wherein a small measured quantity of the polyol resin is "pre-reacted" with a larger quantity of the isocyanate in a defined ratio such that when the necessary remaining quantity of the polyol resin is added to the "pre-reacted" resin together with a tertiary amine catalyst and water as a blowing agent, the polymerization proceeds slowly enough to provide a stable foam body.

  13. On high-order perturbative calculations at finite density

    Energy Technology Data Exchange (ETDEWEB)

    Ghişoiu, Ioan, E-mail: ioan.ghisoiu@helsinki.fi [Helsinki Institute of Physics and Department of Physics, University of Helsinki (Finland); Gorda, Tyler, E-mail: tyler.gorda@helsinki.fi [Helsinki Institute of Physics and Department of Physics, University of Helsinki (Finland); Department of Physics, University of Colorado Boulder, Boulder, CO (United States); Kurkela, Aleksi, E-mail: aleksi.kurkela@cern.ch [Theoretical Physics Department, CERN, Geneva (Switzerland); Faculty of Science and Technology, University of Stavanger, Stavanger (Norway); Romatschke, Paul, E-mail: paul.romatschke@colorado.edu [Department of Physics, University of Colorado Boulder, Boulder, CO (United States); Center for Theory of Quantum Matter, University of Colorado, Boulder, CO (United States); Säppi, Matias, E-mail: matias.sappi@helsinki.fi [Helsinki Institute of Physics and Department of Physics, University of Helsinki (Finland); Vuorinen, Aleksi, E-mail: aleksi.vuorinen@helsinki.fi [Helsinki Institute of Physics and Department of Physics, University of Helsinki (Finland)

    2017-02-15

    We discuss the prospects of performing high-order perturbative calculations in systems characterized by a vanishing temperature but finite density. In particular, we show that the determination of generic Feynman integrals containing fermionic chemical potentials can be reduced to the evaluation of three-dimensional phase space integrals over vacuum on-shell amplitudes — a result reminiscent of a previously proposed “naive real-time formalism” for vacuum diagrams. Applications of these rules are discussed in the context of the thermodynamics of cold and dense QCD, where it is argued that they facilitate an extension of the Equation of State of cold quark matter to higher perturbative orders.

  14. Characterization of composite high density polyethylene and layered zirconium phosphate

    International Nuclear Information System (INIS)

    Lino, Adan S.; Silva, Daniela F.; Mendes, Luis C.

    2011-01-01

    Zirconium phosphate (ZrP) (2 w%), synthesized by direct precipitation method, was used in the preparation of composite with high density polyethylene (HDPE), through extrusion processing in the molten state. Wide angle x-ray diffraction (WAXD), stress-strain mechanical analysis and scanning electron microscopy (SEM) techniques were used for ZrP, neat polymer and composite mechanical and morphologic characterization. Although there was a slight increase in the Young modulus, WAXD and SEM analysis showed that the intercalation of the HDPE matrix in the filler galleries did not occur, probably due to the insufficient lamellae spacing to intercalate the polymer chains. Then, a microcomposite was achieved. (author)

  15. Structure of high-density amorphous ice under pressure

    International Nuclear Information System (INIS)

    Klotz, S.; Hamel, G.; Loveday, J.S.; Nelmes, R.J.; Guthrie, M.; Soper, A.K.

    2002-01-01

    We report in situ neutron diffraction studies of high-density amorphous ice (HDA) at 100 K at pressures up to 2.2 GPa. We find that the compression is achieved by a strong contraction (∼20%) of the second neighbor coordination shell, so that at 2.2 GPa it closely approaches the first coordination shell, which itself remains intact in both structure and size. The hydrogen bond orientations suggest an absence of hydrogen bonding between first and second shells and that HDA has increasingly interpenetrating hydrogen bond networks under pressure

  16. Behavior of high-density spent-fuel storage racks

    International Nuclear Information System (INIS)

    Bailey, W.J.

    1986-08-01

    Included in this report is a summary of information on neutron-absorbing materials such as B 4 C in an aluminum matrix or organic binder material, stainless steel-boron and aluminum-boron alloys, and stainless steetl-clad cadmium that are used in high-density spent fuel storage racks. A list of the types of neutron-absorbing materials being used in spent fuel storage racks at domestic commercial plants is provided. Recent cases at several domestic plants where swelling of rack side plates (where the B 4 C in an aluminum matrix and B 4 C in an organic binder material were located) occurred are reviewed

  17. The Pulsed High Density Experiment (PHDX) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Slough, John P. [Univ. of Washington, Seattle, WA (United States); Andreason, Samuel [Univ. of Washington, Seattle, WA (United States)

    2017-04-27

    The purpose of this paper is to present the conclusions that can be drawn from the Field Reversed Configuration (FRC) formation experiments conducted on the Pulsed High Density experiment (PHD) at the University of Washington. The experiment is ongoing. The experimental goal for this first stage of PHD was to generate a stable, high flux (>10 mWb), high energy (>10 KJ) target FRC. Such results would be adequate as a starting point for several later experiments. This work focuses on experimental implementation and the results of the first four month run. Difficulties were encountered due to the initial on-axis plasma ionization source. Flux trapping with this ionization source acting alone was insufficient to accomplish experimental objectives. Additional ionization methods were utilized to overcome this difficulty. A more ideal plasma source layout is suggested and will be explored during a forthcoming work.

  18. Feedback controlled, reactor relevant, high-density, high-confinement scenarios at ASDEX Upgrade

    Science.gov (United States)

    Lang, P. T.; Blanken, T. C.; Dunne, M.; McDermott, R. M.; Wolfrum, E.; Bobkov, V.; Felici, F.; Fischer, R.; Janky, F.; Kallenbach, A.; Kardaun, O.; Kudlacek, O.; Mertens, V.; Mlynek, A.; Ploeckl, B.; Stober, J. K.; Treutterer, W.; Zohm, H.; ASDEX Upgrade Team

    2018-03-01

    One main programme topic at the ASDEX Upgrade all-metal-wall tokamak is development of a high-density regime with central densities at reactor grade level while retaining high-confinement properties. This required development of appropriate control techniques capable of coping with the pellet tool, a powerful means of fuelling but one which presented challenges to the control system for handling of related perturbations. Real-time density profile control was demonstrated, raising the core density well above the Greenwald density while retaining the edge density in order to avoid confinement losses. Recently, a new model-based approach was implemented that allows direct control of the central density. Investigations focussed first on the N-seeding scenario owing to its proven potential to yield confinement enhancements. Combining pellets and N seeding was found to improve the divertor buffering further and enhance the operational range accessible. For core densities up to about the Greenwald density, a clear improvement with respect to the non-seeding reference was achieved; however, at higher densities this benefit is reduced. This behaviour is attributed to recurrence of an outward shift of the edge density profile, resulting in a reduced peeling-ballooning stability. This is similar to the shift seen during strong gas puffing, which is required to prevent impurity influx in ASDEX Upgrade. First tests indicate that highly-shaped plasma configurations like the ITER base-line scenario, respond very well to pellet injection, showing efficient fuelling with no measurable impact on the edge density profile.

  19. High level radiation dosimetry in biomedical research

    International Nuclear Information System (INIS)

    Inada, Tetsuo

    1979-01-01

    The physical and biological dosimetries relating to cancer therapy with radiation were taken up at the first place in the late intercomparison on high LET radiation therapy in Japan-US cancer research cooperative study. The biological dosimetry, the large dose in biomedical research, the high dose rate in biomedical research and the practical dosimeters for pulsed neutrons or protons are outlined with the main development history and the characteristics which were obtained in the relating experiments. The clinical neutron facilities in the US and Japan involved in the intercomparison are presented. Concerning the experimental results of dosimeters, the relation between the R.B.E. compared with Chiba (Cyclotron in National Institute of Radiological Sciences) and the energy of deuterons or protons used for neutron production, the survival curves of three cultured cell lines derived from human cancers, after the irradiation of 250 keV X-ray, cyclotron neutrons of about 13 MeV and Van de Graaff neutrons of about 2 MeV, the hatchability of dry Artemia eggs at the several depths in an absorber stack irradiated by 60 MeV proton beam of 40, 120 and 200 krad, the peak skin reaction of mouse legs observed at various sets of average and instantaneous dose rates, and the peak skin reaction versus three instantaneous dose rates at fixed average dose rate of 7,300 rad/min are shown. These actual data were evaluated numerically and in relation to the physical meaning from the viewpoint of the fundamental aspect of cancer therapy, comparing the Japanese measured values to the US data. The discussion record on the high dose rate effect of low LET particles on biological substances and others is added. (Nakai, Y.)

  20. Exposure to long wavelength ultraviolet radiation decreases processing of low density lipoprotein by cultured human fibroblasts

    International Nuclear Information System (INIS)

    Djavaheri-Mergny, M.; Santus, R.; Mora, L.; Maziere, J.C.; Faculte de Medecine Saint-Antoine, 75 -Paris; Maziere, C.; Auclair, M.; Dubertret, L.

    1993-01-01

    Exposure of MRC5 human fibroblasts to UVA radiation (365 nm) resulted in a dose-dependent decrease in low density lipoprotein (LDL) uptake and degradation by cells. Following a 25 J/cm 2 irradiation dose, about 45% and 70% reduction in 125 I-LDL uptake and degradation were observed, respectively. Under the same conditions, the 14 C-sucrose uptake was also decreased to about the same extent as LDL uptake. Cell pretreatment with the antioxidants vitamin E and vitamin C did not prevent the UVA-induced fall in LDL degradation. These results point to the possible effects of UVA radiation on receptor-mediated and nonspecific uptake of exogenous molecules. With special regard to the alterations in receptor-mediated processing of exogenous ligands, such a phenomenon could be of importance in UVA-induced skin degenerative processes. (Author)

  1. Search for ionisation density effects in the radiation absorption stage in LiF:Mg,Ti

    International Nuclear Information System (INIS)

    Nail, I.; Horowitz, Y. S.; Oster, L.; Brandan, M. E.; Rodriguez-Villafuerte, M.; Buenfil, A. E.; Ruiz-Trejo, C.; Gamboa-deBuen, I.; Avila, O.; Tovar, V. M.; Olko, P.; Ipe, N.

    2006-01-01

    Optical absorption (OA) dose-response of LiF:Mg,Ti (TLD-100) is studied as a function of electron energy (ionisation density) and irradiation dose. Contrary to the situation in thermoluminescence dose-response where the supra-linearity is strongly energy-dependent, no dependence of the OA dose filling constants on energy is observed. This result is interpreted as indicating a lack of competitive process in the radiation absorption stage. The lack of an energy dependence of the dose filling constant also suggests that the charge carrier migration distances are sufficiently large to smear out the differences in the non-uniform distribution of ionisation events created by the impinging gamma/ electron radiation of various energies. (authors)

  2. Effects of nitrogen application and plant densities on flower yield, essential oils, and radiation use efficiency of Marigold (Calendula officinalis L.)

    International Nuclear Information System (INIS)

    Ameri, A.A.; Nasiri Mahalati, M.

    2010-01-01

    Efficient use of radiation for medicinal plants production, might increase flower yield, essential oils and extract yield .A split plot design.was used in a two years (2005 and 2006) field study in Torogh region(36,10° N,59.33° E and 1300 m altitude) of Mashhad, Iran, to observe the effects of different nitrogen application and plants densities on flower dry matter production, essential oils, and radiation use efficiency in a multi-harvested Marigold (Calendula officinalis). The levels of nitrogen fertilizer were 0, 50, 100 and 150 kg ha-1 and levels of density were 20, 40, 60 and 80 plant m-2. The combined analysis results revealed significant effects of nitrogen and density levels on flower dry matter production, essential oils, and radiation use efficiency of Marigold. The highest dry flower production obtained by 150 kg ha-1 N and 80 plant m-2 plant population (102.86 g m-2). The higher flower dry matter production caused more essential oils and extract production in high nitrogen and density levels. The amount of essential oils and extract per 100g flower dry matter decreased during the flower harvesting period. The higher amount of essential oil and extract obtained at early flowering season. The essential oil and extract ranged from 0.22 to 0.12 (ml. per 100g flower dry matter) and 2.74 to 2.13 (g per 100g flower dry matter) respectively. Increase of both nitrogen and density caused higher radiation use efficiency. The most radiation use efficiency obtained at 150 kg ha-1 nitrogen and 80 Plant m-2desity treatments. In 150 kg ha-1 nitrogen treatment, increase of density levels from 20 plant m-2 to 80 Plant m-2 caused increase in radiation use efficiency from 1.41 g MJ-1 to 1.44 g MJ-1 respectively

  3. Radiation protection around high energy proton accelerators

    International Nuclear Information System (INIS)

    Bourgois, L.

    1996-01-01

    Proton accelerators are intense radiation sources because of the particle beam itself, secondary radiation and structure activation. So radiation protection is required around these equipment during running time but even during downtime. This article presents some estimated values about structure and air activation and applies the Moyer model to get dose rate behind shielding. (A.C.)

  4. Parametrization of the average ionization and radiative cooling rates of carbon plasmas in a wide range of density and temperature

    OpenAIRE

    Gil de la Fe, Juan Miguel; Rodriguez Perez, Rafael; Florido, Ricardo; Garcia Rubiano, Jesus; Mendoza, M.A.; Nuez, A. de la; Espinosa, G.; Martel Escobar, Carlos; Mínguez Torres, Emilio

    2013-01-01

    In this work we present an analysis of the influence of the thermodynamic regime on the monochromatic emissivity, the radiative power loss and the radiative cooling rate for optically thin carbon plasmas over a wide range of electron temperature and density assuming steady state situations. Furthermore, we propose analytical expressions depending on the electron density and temperature for the average ionization and cooling rate based on polynomial fittings which are valid for the whole range...

  5. Changes in mechanical properties due to gamma irradiation of high-density polyethylene (HDPE

    Directory of Open Access Journals (Sweden)

    S. S. Cota

    2007-06-01

    Full Text Available This paper presents an experimental analysis of the effect of dose and dose rate parameters during gamma irradiation of high-density polyethylene (HDPE samples. Considerations concerning the influence of these parameters on HDPE mechanical strength properties as a result of the predominance of oxidative degradation or of cross-linking are presented. The experimental results show an improvement of HDPE mechanical strength as dose increases, indicating the predominance of cross-linking over oxidative degradation and that lower doses are necessary to obtain a similar change in resistance parameters when radiation is applied at lower dose rates, showing that gamma radiation affects the HDPE in a more efficient way at lower dose rates.

  6. Changes in mechanical properties due to gamma irradiation of high-density polyethylene (HDPE)

    International Nuclear Information System (INIS)

    Cota, S.S.; Vasconcelos, V.; Senne Junior, M.; Carvalho, L.L.; Rezende, D.B.; Correa, R.F.

    2007-01-01

    This paper presents an experimental analysis of the effect of dose and dose rate parameters during gamma irradiation of high-density polyethylene (HDPE) samples. Considerations concerning the influence of these parameters on HDPE mechanical strength properties as a result of the predominance of oxidative degradation or of cross-linking are presented. The experimental results show an improvement of HDPE mechanical strength as dose increases, indicating the predominance of cross-linking over oxidative degradation and that lower doses are necessary to obtain a similar change in resistance parameters when radiation is applied at lower dose rates, showing that gamma radiation affects the HDPE in a more efficient way at lower dose rates. (author)

  7. Molecular Dynamics Simulation of High Density DNA Arrays

    Directory of Open Access Journals (Sweden)

    Rudolf Podgornik

    2018-01-01

    Full Text Available Densely packed DNA arrays exhibit hexagonal and orthorhombic local packings, as well as a weakly first order transition between them. While we have some understanding of the interactions between DNA molecules in aqueous ionic solutions, the structural details of its ordered phases and the mechanism governing the respective phase transitions between them remains less well understood. Since at high DNA densities, i.e., small interaxial spacings, one can neither neglect the atomic details of the interacting macromolecular surfaces nor the atomic details of the intervening ionic solution, the atomistic resolution is a sine qua non to properly describe and analyze the interactions between DNA molecules. In fact, in order to properly understand the details of the observed osmotic equation of state, one needs to implement multiple levels of organization, spanning the range from the molecular order of DNA itself, the possible ordering of counterions, and then all the way to the induced molecular ordering of the aqueous solvent, all coupled together by electrostatic, steric, thermal and direct hydrogen-bonding interactions. Multiscale simulations therefore appear as singularly suited to connect the microscopic details of this system with its macroscopic thermodynamic behavior. We review the details of the simulation of dense atomistically resolved DNA arrays with different packing symmetries and the ensuing osmotic equation of state obtained by enclosing a DNA array in a monovalent salt and multivalent (spermidine counterions within a solvent permeable membrane, mimicking the behavior of DNA arrays subjected to external osmotic stress. By varying the DNA density, the local packing symmetry, and the counterion type, we are able to analyze the osmotic equation of state together with the full structural characterization of the DNA subphase, the counterion distribution and the solvent structural order in terms of its different order parameters and

  8. Pulsed high-density plasmas for advanced dry etching processes

    International Nuclear Information System (INIS)

    Banna, Samer; Agarwal, Ankur; Cunge, Gilles; Darnon, Maxime; Pargon, Erwine; Joubert, Olivier

    2012-01-01

    Plasma etching processes at the 22 nm technology node and below will have to satisfy multiple stringent scaling requirements of microelectronics fabrication. To satisfy these requirements simultaneously, significant improvements in controlling key plasma parameters are essential. Pulsed plasmas exhibit considerable potential to meet the majority of the scaling challenges, while leveraging the broad expertise developed over the years in conventional continuous wave plasma processing. Comprehending the underlying physics and etching mechanisms in pulsed plasma operation is, however, a complex undertaking; hence the full potential of this strategy has not yet been realized. In this review paper, we first address the general potential of pulsed plasmas for plasma etching processes followed by the dynamics of pulsed plasmas in conventional high-density plasma reactors. The authors reviewed more than 30 years of academic research on pulsed plasmas for microelectronics processing, primarily for silicon and conductor etch applications, highlighting the potential benefits to date and challenges in extending the technology for mass-production. Schemes such as source pulsing, bias pulsing, synchronous pulsing, and others in conventional high-density plasma reactors used in the semiconductor industry have demonstrated greater flexibility in controlling critical plasma parameters such as ion and radical densities, ion energies, and electron temperature. Specifically, plasma pulsing allows for independent control of ion flux and neutral radicals flux to the wafer, which is key to eliminating several feature profile distortions at the nanometer scale. However, such flexibility might also introduce some difficulty in developing new etching processes based on pulsed plasmas. Therefore, the main characteristics of continuous wave plasmas and different pulsing schemes are compared to provide guidelines for implementing different schemes in advanced plasma etching processes based on

  9. Influence of reagents mixture density on the radiation-thermal synthesis of lithium-zinc ferrites

    Science.gov (United States)

    Surzhikov, A. P.; Lysenko, E. N.; Vlasov, V. A.; Malyshev, A. V.; Korobeynikov, M. V.; Mikhailenko, M. A.

    2017-01-01

    Influence of Li2CO3-ZnO-Fe2O3 powder reagents mixture density on the synthesis efficiency of lithium-zinc ferrites in the conditions of thermal heating or pulsed electron beam heating was studied by X-Ray diffraction and magnetization analysis. The results showed that the including a compaction of powder reagents mixture in ferrite synthesis leads to an increase in concentration of the spinel phase and decrease in initial components content in lithium-substituted ferrites synthesized by thermal or radiation-thermal heating.

  10. Non-primordial origin of the cosmic background radiation and pregalactic density fluctuations

    International Nuclear Information System (INIS)

    Froehlich, H.E.; Mueller, V.; Oleak, H.

    1984-01-01

    Assumptions of a tepid Universe and a smaller primordial contribution to the 3 K background are made to show that Pop III stars may be responsible for the 3 K background and cosmic ray entropy. The 3 K background would be caused by thermalized stellar radiation produced by metallized intergalactic dust formed in first generation stars. A range of mass scales and amplification factors of density perturbations in the early Universe is examined below the Jeans mass for gravitational instabilities. The density perturbations that could have been present at small enough mass scales could have survived and generated sonic modes that propagated through the plasma era and, when combined with additional gravitationally unstable entropy disturbances after recombination, triggered the formation of Pop III stars. 13 references

  11. Biominetic High Density Lipoproteins for the Delivery of Therapeutic Oligonucleotides

    Science.gov (United States)

    Tripathy, Sushant

    Advances in nanotechnology have brought about novel inorganic and hybrid nanoparticles with unique physico-chemical properties that make them suitable for a broad range of applications---from nano-circuitry to drug delivery. A significant part of those advancements have led to ground-breaking discoveries that have changed the approaches to formulation of therapeutics against diseases, such as cancer. Now-a-days the focus does not lie solely on finding a candidate small-molecule therapeutic with minimal adverse effects, but researchers are looking up to nanoparticles to improve biodistribution and biocompatibility profile of clinically proven therapeutics. The plethora of conjugation chemistries offered by currently extant inorganic nanoparticles have, in recent years, led to great leaps in the field of biomimicry---a modality that promises high biocompatibility. Further, in the pursuit of highly specific therapeutic molecules, researchers have turned to silencing oligonucleotides and some have already brought together the strengths of nanoparticles and silencing oligonucleotides in search of an efficacious therapy for cancer with minimal adverse effects. This dissertation work focuses on such a biomimetic platform---a gold nanoparticle based high density lipoprotein biomimetic (HDL NP), for the delivery of therapeutic oligonucleotides. The first chapter of this body of work introduces the molecular target of the silencing oligonucleotides---VEGFR2, and its role in the progression of solid tumor cancers. The background information also covers important aspects of natural high density lipoproteins (HDL), especially their innate capacity to bind and deliver exogenous and endogenous silencing oligonucleotides to tissues that express their high affinity receptor SRB1. We subsequently describe the synthesis of the biomimetic HDL NP and its oligonucleotide conjugates, and establish their biocompatibility. Further on, experimental data demonstrate the efficacy of silencing

  12. High Temperature Radiators for Electric Propulsion Systems, Phase I

    Data.gov (United States)

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

  13. Strongly Interacting Matter at Very High Energy Density

    International Nuclear Information System (INIS)

    McLerran, L.

    2011-01-01

    The authors discuss the study of matter at very high energy density. In particular: what are the scientific questions; what are the opportunities to makes significant progress in the study of such matter and what facilities are now or might be available in the future to answer the scientific questions? The theoretical and experimental study of new forms of high energy density matter is still very much a 'wild west' field. There is much freedom for developing new concepts which can have order one effects on the way we think about such matter. It is also a largely 'lawless' field, in that concepts and methods are being developed as new information is generated. There is also great possibility for new experimental discovery. Most of the exciting results from RHIC experiments were unanticipated. The methods used for studying various effects like flow, jet quenching, the ridge, two particle correlations etc. were developed as experiments evolved. I believe this will continue to be the case at LHC and as we use existing and proposed accelerators to turn theoretical conjecture into tangible reality. At some point this will no doubt evolve into a precision science, and that will make the field more respectable, but for my taste, the 'wild west' times are the most fun.

  14. Development of technology of high density LEU dispersion fuel fabrication

    International Nuclear Information System (INIS)

    Wiencek, T.; Totev, T.

    2007-01-01

    Advanced Materials Fabrication Facilities at Argonne National Laboratory have been involved in development of LEU dispersion fuel for research and test reactors from the beginning of RERTR program. This paper presents development of technology of high density LEU dispersion fuel fabrication for full size plate type fuel elements. A brief description of Advanced Materials Fabrication Facilities where development of the technology was carried out is given. A flow diagram of the manufacturing process is presented. U-Mo powder was manufactured by the rotating electrode process. The atomization produced a U-Mo alloy powder with a relatively uniform size distribution and a nearly spherical shape. Test plates were fabricated using tungsten and depleted U-7 wt.% Mo alloy, 4043 Al and Al-2 wt% Si matrices with Al 6061 aluminum alloy for the cladding. During the development of the technology of manufacturing of full size high density LEU dispersion fuel plates special attention was paid to meet the required homogeneity, bonding, dimensions, fuel out of zone and other mechanical characteristics of the plates.

  15. Regional Lung Density Changes After Radiation Therapy for Tumors in and Around Thorax

    International Nuclear Information System (INIS)

    Ma Jinli; Zhang Junan; Zhou Sumin; Hubbs, Jessica L.; Foltz, Rodney J.; Hollis, Donna R.; Light, Kim L.; Wong, Terence Z.; Kelsey, Christopher R.; Marks, Lawrence B.

    2010-01-01

    Purpose: To study the temporal nature of regional lung density changes and to assess whether the dose-dependent nature of these changes is associated with patient- and treatment-associated factors. Methods and Materials: Between 1991 and 2004, 118 patients with interpretable pre- and post-radiation therapy (RT) chest computed tomography (CT) scans were evaluated. Changes in regional lung density were related to regional dose to define a dose-response curve (DRC) for RT-induced lung injury using three-dimensional planning tools and image fusion. Multiple post-RT follow-up CT scans were evaluated by fitting linear-quadratic models of density changes on dose with time as the covariate. Various patient- and treatment-related factors were examined as well. Results: There was a dose-dependent increase in regional lung density at nearly all post-RT follow-up intervals. The population volume-weighted changes evolved over the initial 6-month period after RT and reached a plateau thereafter (p < 0.001). On univariate analysis, patient age greater than 65 years (p = 0.003) and/or the use of pre-RT surgery (p < 0.001) were associated with significantly greater changes in CT density at both 6 and 12 months after RT, but the magnitude of this effect was modest. Conclusions: There appears to be a temporal nature for the dose-dependent increases in lung density. Nondosimetric clinical factors tend to have no, or a modest, impact on these changes.

  16. Highly sensitive microcalorimeters for radiation research

    International Nuclear Information System (INIS)

    Avaev, V.N.; Demchuk, B.N.; Ioffe, L.A.; Efimov, E.P.

    1984-01-01

    Calorimetry is used in research at various types of nuclear-physics installations to obtain information on the quantitative and qualitative composition of ionizing radiation in a reactor core and in the surrounding layers of the biological shield. In this paper, the authors examine the characteristics of highly sensitive microcalorimeters with modular semiconductor heat pickups designed for operation in reactor channels. The microcalorimeters have a thin-walled aluminum housing on whose inner surface modular heat pickups are placed radially as shown here. The results of measurements of the temperature dependence of the sensitivity of the microcalorimeters are shown. The results of measuring the sensitivity of a PMK-2 microcalorimeter assembly as a function of integrated neutron flux for three energy intervals and the adsorbed gamma energy are shown. In order to study specimens with different shapes and sizes, microcalorimeters with chambers in the form of cylinders and a parallelepiped were built and tested

  17. A Fiber-Optic System Generating Pulses of High Spectral Density

    Science.gov (United States)

    Abramov, A. S.; Zolotovskii, I. O.; Korobko, D. A.; Fotiadi, A. A.

    2018-03-01

    A cascade fiber-optic system that generates pulses of high spectral density by using the effect of nonlinear spectral compression is proposed. It is demonstrated that the shape of the pulse envelope substantially influences the degree of compression of its spectrum. In so doing, maximum compression is achieved for parabolic pulses. The cascade system includes an optical fiber exhibiting normal dispersion that decreases along the fiber length, thereby ensuring that the pulse envelope evolves toward a parabolic shape, along with diffraction gratings and a fiber spectral compressor. Based on computer simulation, we determined parameters of cascade elements leading to maximum spectral density of radiation originating from a subpicosecond laser pulse of medium energy.

  18. Characteristics of heat shrinkable high density polyethylene crosslinked by γ-irradiation

    International Nuclear Information System (INIS)

    Kang, Phil Hyun; Nho, Young Chang

    2001-01-01

    The effects of γ-irradiation on the crosslinking of high density polyethylene (HDPE) was investigated for the purpose of obtaining a suitable formulation for heat shrinkable materials. In this study the HDPE specimens were prepared by blending with cross linking agents and pressed into a 0.2 mm sheet at 180 .deg. C. γ-irradiation was conducted at 40 to 100 kGy in nitrogen. The heat shrinkable property and thermal mechanical property of the HDPE sheets have been investigated. It was found that the degree of crosslinking of the irradiated HDPE samples were increased with irradiation dose. Compared with the HDPE containing triallylisocyanurate, the HDPE containing trimethlol propane triacrylate shows a slight increase in crosslinking density. The heat transformation and dimension change of HDPE decreased with increasing radiation dose. The heat shrinkage of the samples increased with increasing annealing temperatures. The thermal resistance of HDPE increased upon the crosslinking of HDPE

  19. EVALUATION OF SOME PLUM CULTIVARS IN A HIGH DENSITY SYSTEM

    Directory of Open Access Journals (Sweden)

    Madalina Butac

    2014-12-01

    Full Text Available Three plum cultivars bred in Romania (‘Carpatin’, ‘Centenar’ and ‘Tita’ were tested together with several standards (‘Cacanska Rodna’ and ‘Stanley’ in a high density experimental orchard established at Pitesti - Maracineni in the spring of 2009, with spacing 4 x 2.25 m. Trees were trained as spindles, grafted on ‘Saint Julian’ rootstock. In the orchard the following characteristics were evaluated: tree vigour based upon measuring of trunk-diameter, yields in kg/tree, time of fruit ripening and basic parameters of fruit quality. All Romanian varieties were characterized by earliness and large fruit, but production was relatively small. Instead, foreign varieties were characterized by high productivity in the 4th year after planting.

  20. Laboratory Astrophysics Using High Energy Density Photon and Electron Beams

    CERN Document Server

    Bingham, Robert

    2005-01-01

    The development of intense laser and particle beams has opened up new opportunities to study high energy density astrophysical processes in the Laboratory. With even higher laser intensities possible in the near future vacuum polarization processes such as photon - photon scattering with or without large magnetic fields may also be experimentally observed. In this talk I will review the status of laboratory experiments using intense beans to investigate extreme astrophysical phenomena such as supernovae explosions, gamma x-ray bursts, ultra-high energy cosmic accelerators etc. Just as intense photon or electron beams can excite relativistic electron plasma waves or wakefields used in plasma acceleration, intense neutrino beams from type II supernovae can also excite wakefields or plasma waves. Other instabilities driven by intense beams relevant to perhaps x-ray bursts is the Weibel instability. Simulation results of extreme processes will also be presented.

  1. Rationally designed polyimides for high-energy density capacitor applications.

    Science.gov (United States)

    Ma, Rui; Baldwin, Aaron F; Wang, Chenchen; Offenbach, Ido; Cakmak, Mukerrem; Ramprasad, Rampi; Sotzing, Gregory A

    2014-07-09

    Development of new dielectric materials is of great importance for a wide range of applications for modern electronics and electrical power systems. The state-of-the-art polymer dielectric is a biaxially oriented polypropylene (BOPP) film having a maximal energy density of 5 J/cm(3) and a high breakdown field of 700 MV/m, but with a limited dielectric constant (∼2.2) and a reduced breakdown strength above 85 °C. Great effort has been put into exploring other materials to fulfill the demand of continuous miniaturization and improved functionality. In this work, a series of polyimides were investigated as potential polymer materials for this application. Polyimide with high dielectric constants of up to 7.8 that exhibits low dissipation factors (dielectric constant and band gap. Correlations of experimental and theoretical results through judicious variations of polyimide structures allowed for a clear demonstration of the relationship between chemical functionalities and dielectric properties.

  2. DIAGNOSTICS FOR ION BEAM DRIVEN HIGH ENERGY DENSITY PHYSICS EXPERIMENTS

    International Nuclear Information System (INIS)

    Bieniosek, F.M.; Henestroza, E.; Lidia, S.; Ni, P.A.

    2010-01-01

    Intense beams of heavy ions are capable of heating volumetric samples of matter to high energy density. Experiments are performed on the resulting warm dense matter (WDM) at the NDCX-I ion beam accelerator. The 0.3 MeV, 30-mA K + beam from NDCX-I heats foil targets by combined longitudinal and transverse neutralized drift compression of the ion beam. Both the compressed and uncompressed parts of the NDCX-I beam heat targets. The exotic state of matter (WDM) in these experiments requires specialized diagnostic techniques. We have developed a target chamber and fielded target diagnostics including a fast multi-channel optical pyrometer, optical streak camera, laser Doppler-shift interferometer (VISAR), beam transmission diagnostics, and high-speed gated cameras. We also present plans and opportunities for diagnostic development and a new target chamber for NDCX-II.

  3. Preparation and characterization of high-Tc superconducting thin films with high critical current densities

    International Nuclear Information System (INIS)

    Vase, P.

    1991-08-01

    The project was carried out in relation to possible cable and electronics applications of high-T c materials. Laser ablation was used as the deposition technique because of its stoichiometry conservation. Films were made in the YBa 2 Cu 3 O 7 compound due to its relatively simple stoichiometry compared to other High-T c compounds. Much attention was paid to the critical current density. A very high critical current density was reached. By using texture analysis by X-ray diffraction, it was found that films with high critical current densities were epitaxial, while films with low critical current densities contained several crystalline orientations. Four techniques for patterning the films were used - photo lithography and wet etch, laser ablation lithography, laser writing and electron beam lithography and ion milling. Sub-micron patterning has been demonstrated without degradation of the superconducting properties. The achieved patterning resolution is sufficient for preparation of many superconducting components. (AB)

  4. Flexible asymmetric supercapacitors with high energy and high power density in aqueous electrolytes

    Science.gov (United States)

    Cheng, Yingwen; Zhang, Hongbo; Lu, Songtao; Varanasi, Chakrapani V.; Liu, Jie

    2013-01-01

    Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO2, activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s-1 to 500 mV s-1. Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg-1) under high power density (7.8 kW kg-1) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required.Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO2, activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of

  5. Evaluation of high packing density powder X-ray screens by Monte Carlo methods

    International Nuclear Information System (INIS)

    Liaparinos, P.; Kandarakis, I.; Cavouras, D.; Kalivas, N.; Delis, H.; Panayiotakis, G.

    2007-01-01

    Phosphor materials are employed in intensifying screens of both digital and conventional X-ray imaging detectors. High packing density powder screens have been developed (e.g. screens in ceramic form) exhibiting high-resolution and light emission properties, and thus contributing to improved image transfer characteristics and higher radiation to light conversion efficiency. For the present study, a custom Monte Carlo simulation program was used in order to examine the performance of ceramic powder screens, under various radiographic conditions. The model was developed using Mie scattering theory for the description of light interactions, based on the physical characteristics (e.g. complex refractive index, light wavelength) of the phosphor material. Monte Carlo simulations were carried out assuming: (a) X-ray photon energy ranging from 18 up to 49 keV, (b) Gd 2 O 2 S:Tb phosphor material with packing density of 70% and grain size of 7 μm and (c) phosphor thickness ranging between 30 and 70 mg/cm 2 . The variation of the Modulation Transfer Function (MTF) and the Luminescence Efficiency (LE) with respect to the X-ray energy and the phosphor thickness was evaluated. Both aforementioned imaging characteristics were shown to take high values at 49 keV X-ray energy and 70 mg/cm 2 phosphor thickness. It was found that high packing density screens may be appropriate for use in medical radiographic systems

  6. High-Current-Density Vertical-Tunneling Transistors from Graphene/Highly Doped Silicon Heterostructures.

    Science.gov (United States)

    Liu, Yuan; Sheng, Jiming; Wu, Hao; He, Qiyuan; Cheng, Hung-Chieh; Shakir, Muhammad Imran; Huang, Yu; Duan, Xiangfeng

    2016-06-01

    Scalable fabrication of vertical-tunneling transistors is presented based on heterostructures formed between graphene, highly doped silicon, and its native oxide. Benefiting from the large density of states of highly doped silicon, the tunneling transistors can deliver a current density over 20 A cm(-2) . This study demonstrates that the interfacial native oxide plays a crucial role in governing the carrier transport in graphene-silicon heterostructures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Adaptive response to high LET radiations

    International Nuclear Information System (INIS)

    Dam, Annamaria; Bogdandi, E. Noemi; Polonyi, Istvan; Sardy, M. Marta; Balashazy, Imre; Palfalvy, Jozsef

    2001-01-01

    The biological consequences of exposure to ionizing radiation include gene mutation, chromosome aberrations, cellular transformation and cell death. These effects are attributed to the DNA damaging effects of the irradiation resulting in irreversible changes during DNA replication or during the processing of the DNA damage by enzymatic repair processes. These repair processes could initiate some adaptive mechanisms in the cell, which could lead to radioadaptive response (RAR). Adaptive responses have typically been detected by exposing cells to a low radiation dose (1-50 mGy) and then challenging the cells with a higher dose of radiation (2-4 Gy) and comparing the outcome to that seen with the challenge dose only. For adaptive response to be seen the challenge dose must be delivered within 24 hour of the inducing dose. Radio-adaptation is extensively studied for low LET radiation. Nevertheless, few data are available for high LET radiation at very low doses and dose rate. Our study was aimed to investigate the radioadaptive response to low-dose neutron irradiation by detection of the genotoxic damage i.e.: hprt-mutant colonies induced. Altered protein synthesis was also studied to identify stress proteins may responsible for radio-adaptation. New alpha particle irradiator system was also built up to study the biological effects of low dose alpha irradiation. The experiments were carried out on monolayers of human melanoma and CHO (Chines Hamster Ovary) cells irradiated by neutrons produced in the biological irradiation channel of the Research Reactor of Budapest Neutron Center. Cells were exposed to 0.5-50 mGy neutron doses with dose rates of 1.59-10 mGy/min. The challenge doses of 2-4 Gy gamma rays were administrated within 1-48 hours after priming treatment. The induced mutants at hprt locus were selected by adding 6-thioguanine and allow to grow for 10 days for expression of the phenotype. The protein synthesis was studied by PAGE, the molecular mass of specific

  8. Systematics of radiation widths and level density parameters in the mass number range region 40

    International Nuclear Information System (INIS)

    Bychkov, V.M.; Grudzevich, O.T.; Plyaskin, V.I.

    1990-01-01

    We suggest a systematics of radiation width based on a reduced radiative capture strength function for the E1-transition, which eliminates fluctuations in the analysed quantity with neutron binding energy, nuclear level density and γ-quanta energy. A smooth dependence for the fitting parameter of the radiative strength function for E1-transitions in relation to the relative atomic mass of the nucleus is obtained. 10 refs, 2 figs

  9. SU-G-JeP2-02: A Unifying Multi-Atlas Approach to Electron Density Mapping Using Multi-Parametric MRI for Radiation Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Ren, S [Stanford University, Stanford, CA (United States); Tianjin University, Tianjin (China); Hara, W; Le, Q; Wang, L; Xing, L; Li, R [Stanford University, Stanford, CA (United States)

    2016-06-15

    Purpose: MRI has a number of advantages over CT as a primary modality for radiation treatment planning (RTP). However, one key bottleneck problem still remains, which is the lack of electron density information in MRI. In the work, a reliable method to map electron density is developed by leveraging the differential contrast of multi-parametric MRI. Methods: We propose a probabilistic Bayesian approach for electron density mapping based on T1 and T2-weighted MRI, using multiple patients as atlases. For each voxel, we compute two conditional probabilities: (1) electron density given its image intensity on T1 and T2-weighted MR images, and (2) electron density given its geometric location in a reference anatomy. The two sources of information (image intensity and spatial location) are combined into a unifying posterior probability density function using the Bayesian formalism. The mean value of the posterior probability density function provides the estimated electron density. Results: We evaluated the method on 10 head and neck patients and performed leave-one-out cross validation (9 patients as atlases and remaining 1 as test). The proposed method significantly reduced the errors in electron density estimation, with a mean absolute HU error of 138, compared with 193 for the T1-weighted intensity approach and 261 without density correction. For bone detection (HU>200), the proposed method had an accuracy of 84% and a sensitivity of 73% at specificity of 90% (AUC = 87%). In comparison, the AUC for bone detection is 73% and 50% using the intensity approach and without density correction, respectively. Conclusion: The proposed unifying method provides accurate electron density estimation and bone detection based on multi-parametric MRI of the head with highly heterogeneous anatomy. This could allow for accurate dose calculation and reference image generation for patient setup in MRI-based radiation treatment planning.

  10. SU-G-JeP2-02: A Unifying Multi-Atlas Approach to Electron Density Mapping Using Multi-Parametric MRI for Radiation Treatment Planning

    International Nuclear Information System (INIS)

    Ren, S; Hara, W; Le, Q; Wang, L; Xing, L; Li, R

    2016-01-01

    Purpose: MRI has a number of advantages over CT as a primary modality for radiation treatment planning (RTP). However, one key bottleneck problem still remains, which is the lack of electron density information in MRI. In the work, a reliable method to map electron density is developed by leveraging the differential contrast of multi-parametric MRI. Methods: We propose a probabilistic Bayesian approach for electron density mapping based on T1 and T2-weighted MRI, using multiple patients as atlases. For each voxel, we compute two conditional probabilities: (1) electron density given its image intensity on T1 and T2-weighted MR images, and (2) electron density given its geometric location in a reference anatomy. The two sources of information (image intensity and spatial location) are combined into a unifying posterior probability density function using the Bayesian formalism. The mean value of the posterior probability density function provides the estimated electron density. Results: We evaluated the method on 10 head and neck patients and performed leave-one-out cross validation (9 patients as atlases and remaining 1 as test). The proposed method significantly reduced the errors in electron density estimation, with a mean absolute HU error of 138, compared with 193 for the T1-weighted intensity approach and 261 without density correction. For bone detection (HU>200), the proposed method had an accuracy of 84% and a sensitivity of 73% at specificity of 90% (AUC = 87%). In comparison, the AUC for bone detection is 73% and 50% using the intensity approach and without density correction, respectively. Conclusion: The proposed unifying method provides accurate electron density estimation and bone detection based on multi-parametric MRI of the head with highly heterogeneous anatomy. This could allow for accurate dose calculation and reference image generation for patient setup in MRI-based radiation treatment planning.

  11. Exploring high-density baryonic matter: Maximum freeze-out density

    Energy Technology Data Exchange (ETDEWEB)

    Randrup, Joergen [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Cleymans, Jean [University of Cape Town, UCT-CERN Research Centre and Department of Physics, Rondebosch (South Africa)

    2016-08-15

    The hadronic freeze-out line is calculated in terms of the net baryon density and the energy density instead of the usual T and μ{sub B}. This analysis makes it apparent that the freeze-out density exhibits a maximum as the collision energy is varied. This maximum freeze-out density has μ{sub B} = 400 - 500 MeV, which is above the critical value, and it is reached for a fixed-target bombarding energy of 20-30 GeV/N well within the parameters of the proposed NICA collider facility. (orig.)

  12. Rethinking reverse cholesterol transport and dysfunctional high-density lipoproteins.

    Science.gov (United States)

    Gillard, Baiba K; Rosales, Corina; Xu, Bingqing; Gotto, Antonio M; Pownall, Henry J

    2018-04-12

    Human plasma high-density lipoprotein cholesterol concentrations are a negative risk factor for atherosclerosis-linked cardiovascular disease. Pharmacological attempts to reduce atherosclerotic cardiovascular disease by increasing plasma high-density lipoprotein cholesterol have been disappointing so that recent research has shifted from HDL quantity to HDL quality, that is, functional vs dysfunctional HDL. HDL has varying degrees of dysfunction reflected in impaired reverse cholesterol transport (RCT). In the context of atheroprotection, RCT occurs by 2 mechanisms: one is the well-known trans-hepatic pathway comprising macrophage free cholesterol (FC) efflux, which produces early forms of FC-rich nascent HDL (nHDL). Lecithin:cholesterol acyltransferase converts HDL-FC to HDL-cholesteryl ester while converting nHDL from a disc to a mature spherical HDL, which transfers its cholesteryl ester to the hepatic HDL receptor, scavenger receptor B1 for uptake, conversion to bile salts, or transfer to the intestine for excretion. Although widely cited, current evidence suggests that this is a minor pathway and that most HDL-FC and nHDL-FC rapidly transfer directly to the liver independent of lecithin:cholesterol acyltransferase activity. A small fraction of plasma HDL-FC enters the trans-intestinal efflux pathway comprising direct FC transfer to the intestine. SR-B1 -/- mice, which have impaired trans-hepatic FC transport, are characterized by high plasma levels of a dysfunctional FC-rich HDL that increases plasma FC bioavailability in a way that produces whole-body hypercholesterolemia and multiple pathologies. The design of future therapeutic strategies to improve RCT will have to be formulated in the context of these dual RCT mechanisms and the role of FC bioavailability. Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  13. Propofol Anesthesia and Sleep: A High-Density EEG Study

    Science.gov (United States)

    Murphy, Michael; Bruno, Marie-Aurelie; Riedner, Brady A.; Boveroux, Pierre; Noirhomme, Quentin; Landsness, Eric C.; Brichant, Jean-Francois; Phillips, Christophe; Massimini, Marcello; Laureys, Steven; Tononi, Giulio; Boly, Melanie

    2011-01-01

    Study Objectives: The electrophysiological correlates of anesthetic sedation remain poorly understood. We used high-density electroencephalography (hd-EEG) and source modeling to investigate the cortical processes underlying propofol anesthesia and compare them to sleep. Design: 256-channel EEG recordings in humans during propofol anesthesia. Setting: Hospital operating room. Patients or Participants: 8 healthy subjects (4 males) Interventions: N/A Measurements and Results: Initially, propofol induced increases in EEG power from 12–25 Hz. Loss of consciousness (LOC) was accompanied by the appearance of EEG slow waves that resembled the slow waves of NREM sleep. We compared slow waves in propofol to slow waves recorded during natural sleep and found that both populations of waves share similar cortical origins and preferentially propagate along the mesial components of the default network. However, propofol slow waves were spatially blurred compared to sleep slow waves and failed to effectively entrain spindle activity. Propofol also caused an increase in gamma (25–40 Hz) power that persisted throughout LOC. Source modeling analysis showed that this increase in gamma power originated from the anterior and posterior cingulate cortices. During LOC, we found increased gamma functional connectivity between these regions compared to the wakefulness. Conclusions: Propofol anesthesia is a sleep-like state and slow waves are associated with diminished consciousness even in the presence of high gamma activity. Citation: Murphy M; Bruno MA; Riedner BA; Boveroux P; Noirhomme Q; Landsness EC; Brichant JF; Phillips C; Massimini M; Laureys S; Tononi G; Boly M. Propofol anesthesia and sleep: a high-density EEG study. SLEEP 2011;34(3):283-291. PMID:21358845

  14. Study of electron densities of normal and neoplastic human breast tissues by Compton scattering using synchrotron radiation

    International Nuclear Information System (INIS)

    Antoniassi, M.; Conceição, A.L.C.; Poletti, M.E.

    2012-01-01

    Electron densities of 33 samples of normal (adipose and fibroglangular) and neoplastic (benign and malignant) human breast tissues were determined through Compton scattering data using a monochromatic synchrotron radiation source and an energy dispersive detector. The area of Compton peaks was used to determine the electron densities of the samples. Adipose tissue exhibits the lowest values of electron density whereas malignant tissue the highest. The relationship with their histology was discussed. Comparison with previous results showed differences smaller than 4%. - Highlights: ► Electron density of normal and neoplastic breast tissues was measured using Compton scattering. ► Monochromatic synchrotron radiation was used to obtain the Compton scattering data. ► The area of Compton peaks was used to determine the electron densities of samples. ► Adipose tissue shows the lowest electron density values whereas the malignant tissue the highest. ► Comparison with previous results showed differences smaller than 4%.

  15. Gravitational perturbation of the cosmic background radiation by density concentrations. [Swiss cheese model universe

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, C C [Cambridge Univ. (UK). Inst. of Theoretical Astronomy

    1976-05-01

    The gravitational effect of density concentrations in the Universe on the temperature distribution of the cosmic blackbody background radiation is considered, using the Swiss cheese model universe, and supposing each hole to contain an expanding, homogeneous dust sphere at its centre. The temperature profile across such a hole differs in an essential way from that obtained earlier by Rees et al (Nature; 217:511 (1968)). The evolution of this effect with the expansion of the Universe is considered for 'relatively increasing' density contrasts emerging from the same initial singular state as the rest of the Universe. This effect becomes comparable to the bremsstrahlung and Compton effects on the isotropy of the background radiation for masses of about 10/sup 19/ times the mass of the sun, and exceeds these other effects as about Msup(2/3) for larger masses. If large-scale condensations of the Universe can be found for z approximately 1 to 5, delineated, maybe, by the clustering of quasars, etc., then this effect may be observable.

  16. High lane density slab-gel electrophoresis using micromachined instrumentation.

    Science.gov (United States)

    Papautsky, I; Mohanty, S; Weiss, R; Frazier, A B

    2001-10-01

    In this paper, micromachined pipette arrays (MPAs) and microcombs were studied as a means of enabling high lane density gel electrophoresis. The MPA provide a miniaturized format to interface sub-microliter volumes of samples between macroscale sample preparation formats and microscale biochemical analysis systems. The microcombs provide a means of creating sample loading wells in the gel material on the same center-to-center spacing as the MPAs. Together, the two micromachined instruments provide an alternative to current combs and pipetting technologies used for creating sample loading wells and sample delivery in gel electrophoresis systems. Using three designs for the microcomb-MPA pair, center-to-center spacings of 1.0 mm, 500 microm, and 250 microm are studied. The results demonstrate an approximate 10-fold increase in lane density and a 10-fold reduction in sample size from 5 microL to 500 pL. As a result, the number of theoretical plates has increased 2.5-fold, while system resolution has increased 1.5-fold over the conventional agarose gel systems. An examination of changes in resolution across the width of individual separation lanes in both systems revealed dependence in the case of the conventional gels and no dependence for the gels loaded with the micromachined instrumentation.

  17. Exploring novel high power density concepts for attractive fusion systems

    Energy Technology Data Exchange (ETDEWEB)

    Abdou, M.A. [California State Univ., Los Angeles, CA (United States). Dept. of Mechanical Engineering; APEX Team

    1999-05-01

    The advanced power extraction study is aimed at exploring innovative concepts for fusion power technology (FPT) that can tremendously enhance the potential of fusion as an attractive and competitive energy source. Specifically, the study is exploring new and `revolutionary` concepts that can provide the capability to efficiently extract heat from systems with high neutron and surface heat loads while satisfying all the FPT functional requirements and maximizing reliability, maintainability, safety, and environmental requirements. The primary criteria for measuring performance of the new concepts are: (1) high power density capability with a peak neutron wall load (NWL) of {proportional_to}10 MW m{sup -2} and surface heat flux of {proportional_to}2 MW m{sup -2}; (2) high power conversion efficiency, {proportional_to}40% net; and (3) clear potential to achieve high availability; specifically low failure rate, large design margin, and short downtime for maintenance. A requirement that MTBF{>=}43 MTTR was derived as a necessary condition to achieve the required first wall/blanket availability, where MTBF is the mean time between failures and MTTR is the mean time to recover. Highlights of innovative and promising new concepts that may satisfy these criteria are provided. (orig.) 40 refs.

  18. LTCC magnetic components for high density power converter

    Science.gov (United States)

    Lebourgeois, Richard; Labouré, Eric; Lembeye, Yves; Ferrieux, Jean-Paul

    2018-04-01

    This paper deals with multilayer magnetic components for power electronics application and specifically for high frequency switching. New formulations based on nickel-zinc-copper spinel ferrites were developed for high power and high frequency applications. These ferrites can be sintered at low temperature (around 900°C) which makes them compatible with the LTCC (Low Temperature Co-fired Ceramics) technology. Metallic parts of silver or gold can be fully integrated inside the ferrite while guaranteeing the integrity of both the ferrite and the metal. To make inductors or transformers with the required properties, it is mandatory to have nonmagnetic parts between the turns of the winding. Then it is essential to find a dielectric material, which can be co-sintered both with the ferrite and the metal. We will present the solution we found to this problem and we will describe the results we obtained for a multilayer co-sintered transformer. We will see that these new components have good performance compared with the state of the art and are very promising for developing high density switching mode power supplies.

  19. Neutron star evolution and the structure of matter at high density

    International Nuclear Information System (INIS)

    Soyeur, Madeleine.

    1981-09-01

    The structure and properties of neutron stars are determined by the state of cold nuclear matter at high density. In order to investigate the behavior of matter inside neutron stars, observables sensitive to their internal structure have to be calculated and confronted to observations. The thermal radiation of neutron stars seems to be a good candidate to be such observable. It can be shown that the neutrino luminosity of neutron stars, responsible for their cooling in the early stages of their evolution is strongly dependent on possible phase transitions to superfluid nucleons, to pion condensation or to quark matter. The specific heat of matter is also not the same in the various phases expected at high density and is particularly sensitive to the nucleon superfluidity. At present, both the theoretical estimates and the observations of the thermal properties of neutron stars are still quite preliminary. In particular, large uncertainties due to possible reheating mechanisms and magnetic field effects make the theoretical interpretation of the steady radiation of pulsars quite difficult

  20. Essential elements of the high density H-mode on W7-AS

    International Nuclear Information System (INIS)

    McCormick, K.; Burhenn, R.; Grigull, P.

    2003-01-01

    The High Density H-Mode (HDH), discovered during the run-in phase of W7-AS divertor operation/1-3/, rapidly became the workhorse of the divertor program, combining optimal core behavior along with edge parameters necessary for successful operation of an Island Divertor. Its unique properties of high energy confinement along with low impurity retention and radiation localized at the edge under ELM-free steady-state conditions at high densities (to 4 x 10 20 m -3 ) and heating powers (to 1.7 MWm -3 ) make the HDH H-mode ideal for a reactor scenario, given it can be extended to higher temperatures in a larger machine. Hence, considerable effort has been invested to understand the nature of the HDH-mode in order to be able to extrapolate to next generation devices. To this end the present paper reports on experiments where two globally-similar ELM-free H-modes are compared: the classic quiescent H-mode H* where both impurity and density control are a severe problem and the HDH-mode with its contrasting steady-state behavior. Through modeling of the temporal behavior of laser-ablated aluminum spectral lines, as well as that of background impurities, it is concluded that a principle difference between the two H-modes is that of enhanced impurity diffusion in the edge gradient region of the HDH-mode. However, no direct indicators of enhanced diffusion have yet been identified. (orig.)

  1. High mortality of Red Sea zooplankton under ambient solar radiation.

    Science.gov (United States)

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

    2014-01-01

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

  2. High mortality of Red Sea zooplankton under ambient solar radiation.

    Directory of Open Access Journals (Sweden)

    Ali M Al-Aidaroos

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

  3. Post radiation grafting of vinyl acetate onto low density polyethylene films: preparation and properties of membrane

    International Nuclear Information System (INIS)

    Dessouki, A.M.

    1987-01-01

    Reverse osmosis membranes were prepared by the post radiation grafting of vinyl acetate onto low density polyethylene films. The factors affecting the grafting process such as radiation dose, monomer concentration and temperature on the grafting yield were studied. It was found that the dependence of the grafting rate on radiation intensity and monomer concentration was found to be of 0.64 and 1.4 order, respectively. The activation energy for this grafting system was calculated and found to be 4.45 kcal/mol above 30 0 C. Some properties of the grafted films such as specific electric resistance, water uptake, mechanical properties and thermal and chemical stability were investigated. An improvement in these properties was observed which makes possible the use of these membranes in some practical applications. The use of such membranes for reverse osmosis desalination of saline water was tested. The effect of operating time, degree of grafting and applied pressure on the water flux and salt rejection were determined. The results showed salt rejection percent over 90% and a reasonable water flux. A suitable degree of grafting of the membrane was determined as well as the optimum applied pressure. (author)

  4. Jammed Humans in High-Density Crowd Disasters

    Science.gov (United States)

    Bottinelli, Arianna; Sumpter, David; Silverberg, Jesse

    When people gather in large groups like those found at Black Friday sales events, pilgrimages, heavy metal concerts, and parades, crowd density often becomes exceptionally high. As a consequence, these events can produce tragic outcomes such as stampedes and ''crowd crushes''. While human collective motion has been studied with active particle simulations, the underlying mechanisms for emergent behavior are less well understood. Here, we use techniques developed to study jammed granular materials to analyze an active matter model inspired by large groups of people gathering at a point of common interest. In the model, a single behavioral rule combined with body-contact interactions are sufficient for the emergence of a self-confined steady state, where particles fluctuate around a stable position. Applying mode analysis to this system, we find evidence for Goldstone modes, soft spots, and stochastic resonance, which may be the preferential mechanisms for dangerous emergent collective motions in crowds.

  5. A distributed current stimulator ASIC for high density neural stimulation.

    Science.gov (United States)

    Jeong Hoan Park; Chaebin Kim; Seung-Hee Ahn; Tae Mok Gwon; Joonsoo Jeong; Sang Beom Jun; Sung June Kim

    2016-08-01

    This paper presents a novel distributed neural stimulator scheme. Instead of a single stimulator ASIC in the package, multiple ASICs are embedded at each electrode site for stimulation with a high density electrode array. This distributed architecture enables the simplification of wiring between electrodes and stimulator ASIC that otherwise could become too complex as the number of electrode increases. The individual ASIC chip is designed to have a shared data bus that independently controls multiple stimulating channels. Therefore, the number of metal lines is determined by the distributed ASICs, not by the channel number. The function of current steering is also implemented within each ASIC in order to increase the effective number of channels via pseudo channel stimulation. Therefore, the chip area can be used more efficiently. The designed chip was fabricated with area of 0.3 mm2 using 0.18 μm BCDMOS process, and the bench-top test was also conducted to validate chip performance.

  6. Automatic Calibration of High Density Electric Muscle Stimulation

    DEFF Research Database (Denmark)

    Knibbe, Jarrod; Strohmeier, Paul; Boring, Sebastian

    2017-01-01

    . (2) EMS requires time consuming, expert calibration -- confining these interaction techniques to the lab. EMS arrays have been shown to increase stimulation resolution, but as calibration complexity increases exponentially as more electrodes are used, we require heuristics or automated procedures......Electric muscle stimulation (EMS) can enable mobile force feedback, support pedestrian navigation, or confer object affordances. To date, however, EMS is limited by two interlinked problems. (1) EMS is low resolution -- achieving only coarse movements and constraining opportunities for exploration...... for successful calibration. We explore the feasibility of using electromyography (EMG) to auto-calibrate high density EMS arrays. We determine regions of muscle activity during human-performed gestures, to inform stimulation patterns for EMS-performed gestures. We report on a study which shows that auto...

  7. A high-density lipoprotein-mediated drug delivery system.

    Science.gov (United States)

    Mo, Zhong-Cheng; Ren, Kun; Liu, Xing; Tang, Zhen-Li; Yi, Guang-Hui

    2016-11-15

    High-density lipoprotein (HDL) is a comparatively dense and small lipoprotein that can carry lipids as a multifunctional aggregate in plasma. Several studies have shown that increasing the levels or improving the functionality of HDL is a promising target for treating a wide variety of diseases. Among lipoproteins, HDL particles possess unique physicochemical properties, including naturally synthesized physiological components, amphipathic apolipoproteins, lipid-loading and hydrophobic agent-incorporating characteristics, specific protein-protein interactions, heterogeneity, nanoparticles, and smaller size. Recently, the feasibility and superiority of using HDL particles as drug delivery vehicles have been of great interest. In this review, we summarize the structure, constituents, biogenesis, remodeling, and reconstitution of HDL drug delivery systems, focusing on their delivery capability, characteristics, applications, manufacturing, and drug-loading and drug-targeting characteristics. Finally, the future prospects are presented regarding the clinical application and challenges of using HDL as a pharmacodelivery carrier. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Single-Readout High-Density Memristor Crossbar

    KAUST Repository

    Zidan, M. A.

    2016-01-07

    High-density memristor-crossbar architecture is a very promising technology for future computing systems. The simplicity of the gateless-crossbar structure is both its principal advantage and the source of undesired sneak-paths of current. This parasitic current could consume an enormous amount of energy and ruin the readout process. We introduce new adaptive-threshold readout techniques that utilize the locality and hierarchy properties of the computer-memory system to address the sneak-paths problem. The proposed methods require a single memory access per pixel for an array readout. Besides, the memristive crossbar consumes an order of magnitude less power than state-of-the-art readout techniques.

  9. Ultra-high current density thin-film Si diode

    Science.gov (United States)

    Wang, Qi [Littleton, CO

    2008-04-22

    A combination of a thin-film .mu.c-Si and a-Si:H containing diode structure characterized by an ultra-high current density that exceeds 1000 A/cm.sup.2, comprising: a substrate; a bottom metal layer disposed on the substrate; an n-layer of .mu.c-Si deposited the bottom metal layer; an i-layer of .mu.c-Si deposited on the n-layer; a buffer layer of a-Si:H deposited on the i-layer, a p-layer of .mu.c-Si deposited on the buffer layer; and a top metal layer deposited on the p-layer.

  10. Hybrid graphene electrodes for supercapacitors of high energy density

    Science.gov (United States)

    Zhang, Feifei; Tang, Jie; Shinya, Norio; Qin, Lu-Chang

    2013-10-01

    We describe a process of co-reduction to reduce dispersed graphene oxide (GO) and single-walled carbon nanotubes (SWNTs) simultaneously for preparation of hybrid electrodes for graphene supercapacitors. The SWNTs are in between the inter-layer space of graphene sheets as a spacer to prevent effectively restacking of graphene that often limits seriously the electrochemical performance of graphene supercapacitors. The SWNTs also act as conductive binders to improve the electrical conduction of the electrode. A high specific capacitance of 261 F g-1 for a single electrode and specific energy density of 123 W h kg-1 measured in the two-electrode configuration have been obtained in ionic liquid (EMI-TFSI). For interpretation of color in Fig. 6, the reader is referred to the web version of this article.

  11. Sulfurized activated carbon for high energy density supercapacitors

    Science.gov (United States)

    Huang, Yunxia; Candelaria, Stephanie L.; Li, Yanwei; Li, Zhimin; Tian, Jianjun; Zhang, Lili; Cao, Guozhong

    2014-04-01

    Sulfurized activated carbon (SAC), made by coating the pore surface with thiophenic sulfur functional groups from the pyrolysis of sulfur flakes, were characterized and tested for supercapacitor applications. From X-ray photoelectron spectroscopy (XPS), the sulfur content in the SAC was found to be 2.7 at%. Electrochemical properties from potentiostatic and galvanostatic measurements, and electrochemical impedance spectroscopy (EIS) were used to evaluate the effect of sulfur on porous carbon electrodes. The SAC electrode exhibits better conductivity, and an obvious increase in specific capacitance that is almost 40% higher than plain activated carbons (ACs) electrode at a high current density of 1.4 A g-1. The proposed mechanism for improved conductivity and capacitive performance due to the sulfur functional groups on ACs will be discussed.

  12. Diquark Bose Condensates in High Density Matter and Instantons

    International Nuclear Information System (INIS)

    Rapp, R.; Shuryak, E.; Schaefer, T.; Velkovsky, M.

    1998-01-01

    Instantons lead to strong correlations between up and down quarks with spin zero and antisymmetric color wave functions. In cold and dense matter, n b >n c ≅1 fm -3 and T c ∼50 thinspthinspMeV, these pairs Bose condense, replacing the usual left-angle bar qq right-angle condensate and restoring chiral symmetry. At high density, the ground state is a color superconductor in which diquarks play the role of Cooper pairs. An interesting toy model is provided by QCD with two colors: it has a particle-antiparticle symmetry which relates left-angle bar qq right-angle and left-angle qq right-angle condensates. copyright 1998 The American Physical Society

  13. The stability of the High-Density Z-Pinch

    International Nuclear Information System (INIS)

    Glasser, A.H.; Nebel, R.A.

    1989-01-01

    Fiber-initiated High Density Z-Pinches at Los Alamos, NRL, and Karlsruhe have shown anomalously good stability. Kink modes are never seen, and sausage modes are at least delayed until late in the discharge. The success of these devices in reaching fusion conditions may depend on maintaining and understanding this anomalous stability. We have developed two numerical methods to study the stability in the regime where fluid theory is valid. While our methods are applicable to all modes, we will describe them only for the m = 0 sausage mode. The appearance of sausage modes late in the discharge and the total absence of kink modes suggest that an understanding of sausage modes is more urgent, and it is also simpler. 14 refs., 8 figs

  14. The stability of the high-density z-pinch

    International Nuclear Information System (INIS)

    Glasser, A.H.; Nebel, R.A.

    1989-01-01

    Fiber-initiated High Density Z-Pinches at Los Alamos, NRL, and Karlsruhe have shown anomalously good stability. Kink modes are never seen, and sausage modes are at least delayed until late in the discharge. The success of these devices in reaching fusion conditions may depend on maintaining and understanding this anomalous stability. We have developed two numerical methods to study the stability in the regime where fluid theory is valid. While our methods are applicable to all modes, we will describe them only for the m=0 sausage mode. The appearance of sausage modes late in the discharge and the total absence of kink modes suggest that an understanding of sausage modes is more urgent, and it is also simpler

  15. Corrosion of high-density sintered tungsten alloys. Part 2

    International Nuclear Information System (INIS)

    Batten, J.J.; Moore, B.T.

    1988-12-01

    The behaviour of four high-density sintered tungsten alloys has been evluated and compared with that of pure tungsten. Rates of corrosion during the cyclic humidity and the salt mist tests were ascertained from weight loss measurements. Insight into the corrosion mechanism was gained from the nature of the corrosion products and an examination of the corroded surfaces. In the tests, the alloy 95% W, 2.5% Ni, 1.5% Fe was the most corrosion resistant. The data showed that copper as an alloying element accelerates corrosion of tungsten alloys. Both attack on the tungsten particles and the binder phase were observed together with tungsten grain loss. 6 refs., 3 tabs.,

  16. CENTER FOR PULSED POWER DRIVEN HIGH ENERGY DENSITY PLASMA STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Professor Bruce R. Kusse; Professor David A. Hammer

    2007-04-18

    This annual report summarizes the activities of the Cornell Center for Pulsed-Power-Driven High-Energy-Density Plasma Studies, for the 12-month period October 1, 2005-September 30, 2006. This period corresponds to the first year of the two-year extension (awarded in October, 2005) to the original 3-year NNSA/DOE Cooperative Agreement with Cornell, DE-FC03-02NA00057. As such, the period covered in this report also corresponds to the fourth year of the (now) 5-year term of the Cooperative Agreement. The participants, in addition to Cornell University, include Imperial College, London (IC), the University of Nevada, Reno (UNR), the University of Rochester (UR), the Weizmann Institute of Science (WSI), and the P.N. Lebedev Physical Institute (LPI), Moscow. A listing of all faculty, technical staff and students, both graduate and undergraduate, who participated in Center research activities during the year in question is given in Appendix A.

  17. Single-Readout High-Density Memristor Crossbar

    KAUST Repository

    Zidan, M. A.; Omran, Hesham; Naous, Rawan; Salem, Ahmed Sultan; Fahmy, H. A. H.; Lu, W. D.; Salama, Khaled N.

    2016-01-01

    High-density memristor-crossbar architecture is a very promising technology for future computing systems. The simplicity of the gateless-crossbar structure is both its principal advantage and the source of undesired sneak-paths of current. This parasitic current could consume an enormous amount of energy and ruin the readout process. We introduce new adaptive-threshold readout techniques that utilize the locality and hierarchy properties of the computer-memory system to address the sneak-paths problem. The proposed methods require a single memory access per pixel for an array readout. Besides, the memristive crossbar consumes an order of magnitude less power than state-of-the-art readout techniques.

  18. High density submicron magnetoresistive random access memory (invited)

    Science.gov (United States)

    Tehrani, S.; Chen, E.; Durlam, M.; DeHerrera, M.; Slaughter, J. M.; Shi, J.; Kerszykowski, G.

    1999-04-01

    Various giant magnetoresistance material structures were patterned and studied for their potential as memory elements. The preferred memory element, based on pseudo-spin valve structures, was designed with two magnetic stacks (NiFeCo/CoFe) of different thickness with Cu as an interlayer. The difference in thickness results in dissimilar switching fields due to the shape anisotropy at deep submicron dimensions. It was found that a lower switching current can be achieved when the bits have a word line that wraps around the bit 1.5 times. Submicron memory elements integrated with complementary metal-oxide-semiconductor (CMOS) transistors maintained their characteristics and no degradation to the CMOS devices was observed. Selectivity between memory elements in high-density arrays was demonstrated.

  19. Mass terms in effective theories of high density quark matter

    Science.gov (United States)

    Schäfer, T.

    2002-04-01

    We study the structure of mass terms in the effective theory for quasiparticles in QCD at high baryon density. To next-to-leading order in the 1/pF expansion we find two types of mass terms: chirality conserving two-fermion operators and chirality violating four-fermion operators. In the effective chiral theory for Goldstone modes in the color-flavor-locked (CFL) phase the former terms correspond to effective chemical potentials, while the latter lead to Lorentz invariant mass terms. We compute the masses of Goldstone bosons in the CFL phase, confirming earlier results by Son and Stephanov as well as Bedaque and Schäfer. We show that to leading order in the coupling constant g there is no antiparticle gap contribution to the mass of Goldstone modes, and that our results are independent of the choice of gauge.

  20. The alterations in high density polyethylene properties with gamma irradiation

    Science.gov (United States)

    Zaki, M. F.; Elshaer, Y. H.; Taha, Doaa. H.

    2017-10-01

    In the present investigation, high density polyethylene (HDPE) polymer has been used to study the alterations in its properties under gamma-irradiation. Physico-chemical properties have been investigated with different spectroscopy techniques, Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), biocompatibility properties, as well as, mechanical properties change. The FT-IR analysis shows the formation of new band at 1716 cm-1 that is attributed to the oxidation of irradiated polymer chains, which is due to the formation of carbonyl groups (C˭O). XRD patterns show that a decrease in the crystallite size and increase in the Full Width at Half Maximum (FWHM). This means that the crystallinity of irradiated samples is decreased with increase in gamma dose. The contact angle measurements show an increase in the surface free energy as the gamma irradiation increases. The measurements of mechanical properties of irradiated HDPE samples were discussed.