WorldWideScience

Sample records for w-na target bombarded

  1. Proton bombarded reactions of Calcium target nuclei

    Directory of Open Access Journals (Sweden)

    Tel Eyyup

    2017-01-01

    Full Text Available In this study, proton bombarded nuclear reactions calculations of Calcium target nuclei have been investigated in the incident proton energy range of 1–50 MeV. The excitation functions for 40Ca target nuclei reactions have been calculated by using PCROSS nuclear reaction calculation code. Weisskopf-Ewing and the full exciton models were used for equilibrium and for pre-equilibrium calculations, respectively. The excitation functions for 40Ca target nuclei reactions (p,α, (p,n, (p,p have been calculated using the semi-empirical formula Tel et al. [5].

  2. Characteristics of flows of energetic atoms reflected from metal targets during ion bombardment

    Science.gov (United States)

    Kuzmichev, A.; Perevertaylo, V.; Tsybulsky, L.; Volpian, O.

    2016-07-01

    Particle number and energy reflection coefficients for energetic neutralized gas ions (Ar and O atoms) backscattered from metal targets during ion bombardment have been calculated using TRIM code. The energy distributions of reflected atoms are computed, too, and their dependence on the primary ion energy and the angle of ion incidence is determined. The obtained data confirm the possibility of employing energetic atoms reflection for generation of high energy neutral beams and point out to take this phenomenon into account under analysis of the ion technology for coating deposition.

  3. Fast neutron distributions from Be and C thick targets bombarded with 80 and 160 MeV deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Pauwels, N.; Laurent, H.; Clapier, F. [Institut de Physique Nucleaire, (IN2P3/CNRS) 91 - Orsay (France); Brandenburg, S.; Beijers, J.P.M.; Zegers, R.G.T. [Kernfysisch Versneller Institute, Groningen (Netherlands); Lebreton, L. [Universite Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium); Mirea, M. [Institute of Nuclear Physics and Engineering, Bucarest (Romania); Saint-Laurent, M.G. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

    2000-07-01

    Measured angular and energy distributions of neutrons obtained by bombarding Be and C thick targets with deuterons at 80 and 160 MeV incident energies are reported. The data were obtained using the time-of-flight method. The experimental values are compared with a modelization based on stripping formalization extended for thick targets. (authors)

  4. Foil analysis of 1.5-GeV proton bombardment of a mercury target

    CERN Document Server

    Charlton, L A; Glasgow, D C; Gabriel, T A

    1999-01-01

    The number of reactant nuclei in a series of foils surrounding a container of mercury that has been bombarded by 1.5-GeV protons is calculated and compared with experimental measurements. This procedure is done to aid in the validation of the mercury cross sections used in the design studies of the Spallation Neutron Source (SNS). It is found that the calculations match the measurements to within the uncertainties inherent in the analysis.

  5. Measurements of secondary neutrons producted from thick targets bombarded by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, T.; Nakamura, T. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Nakao, N.; Shibata, T.; Uwamino, Y.; Nakanishi, N.; Fukumura, A.; Kumamoto, Y.

    1997-03-01

    We measured neutron angular and energy distributions from high energy heavy ions stopping in targets of carbon, aluminum, copper and lead at HIMAC. These spectra are much harder for the lighter target nucleus like carbon. This means that the momentum transfer in the forward direction from heavy ion beam to lighter nuclei is much higher than that to heavier nuclei. (author)

  6. Cyclotron production of no-carrier-added palladium-103 by bombardment of rhodium-103 target.

    Science.gov (United States)

    Chunfu, Z; Yongxian, W; Yongping, Z; Xiuli, Z

    2001-10-01

    Electroplated rhodium foil was employed as the target for cyclotron production of palladium-103. An electrodissolution apparatus was found better than other dissolution methods in terms of personnel shielding and palladium-103 yield. The ion-exchange column chromatography method was simple and effective for the purification of palladium-103 and the final stripping agent of NH4Cl + NH3(1:1) was more efficient than other agents.

  7. Light Ion Yields from Bombardment of Thick Targets by Protons, Helium-4 and Iron-56

    Science.gov (United States)

    Castellanos, Luis A.; McGirl, Natalie A.; Srikrishna, Ashwin P.; Heilbronn, Lawrence H.; Tessa, Chiara La; Rusek, Adam; Sivertz, Michael; Blattnig, Steve; Clowdsley, Martha; Slaba, Tony; Zeitlin, Cary

    2017-09-01

    In March 2016 accelerator-based experiments colliding protons (0.4 and 0.8 GeV), helium (0.4 AGeV) and iron (0.4 and 0.8 AGeV) on thick aluminum targets with surface densities of 20, 40, and 60 g/cm2 were performed at the National Aeronautics and Space Administration Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory. Two targets were utilized in each experimental configuration. Hydrogen and helium ions were detected using organic liquid scintillators in conjunction with thin plastic scintillators at 10°, 30°, 45°, 60°, 80°, and 135° from beam axis. Time-of-flight techniques and pulse shape discrimination were used to identify light ion species in order to generate double differential energy spectra of the light ion fragments. Comparisons of these measured yields were compared with Monte Carlo calculations generated by MCNP6. These yields will be used to quantify uncertainty in radiation transport codes utilized in risk assessment for spaceflight missions with prolonged exposures to galactic cosmic rays.

  8. Particle bombardment-mediated transient expression to identify localization signals in plant disease resistance proteins and target sites for the proteolytic activity of pathogen effectors.

    Science.gov (United States)

    Takemoto, Daigo; Jones, David A

    2014-01-01

    Plant pathogens, including fungi, oomycetes, bacteria, aphids, and nematodes, produce a variety of effector proteins to counter plant disease resistance mechanisms. After delivery into the cytosol of the plant cell, effectors may target proteins localized to different compartments within the plant cell. Plants, in turn, have evolved disease resistance (R) proteins to recognize the action of effectors. Elucidation of the subcellular localization of pathogen effectors, the plant proteins they target, and plant disease resistance proteins is essential to fully understand their interactions during pathogen challenge. In recent years, expression of fluorescent protein fusions has been widely used to determine the subcellular localization of plant proteins and pathogen effectors. Use of fluorescent proteins enables researchers to monitor the dynamic behavior of proteins in living cells. Among various methods available for the introduction of genes into plant cells, particle bombardment-mediated transient expression is the most rapid method suitable for both the identification of localization signals in proteins of interest and their dissection via amino acid substitutions generated using site-directed mutagenesis. This chapter describes a rapid procedure for particle bombardment-mediated transient expression in leaf epidermal cells. This method is also applicable to detection of pathogen effector protease activities directed against target proteins in the plant cell and analysis of protease recognition sites within these target proteins.

  9. X-ray emission yields from both surfaces of thin targets bombarded with a 200-MeV H sup minus beam

    Energy Technology Data Exchange (ETDEWEB)

    Vanier, P.E.; Zucker, M.S.; Snead, C.L. Jr.

    1988-01-01

    A modified commercial energy-dispersive x-ray spectrometer was used to measure the yields of characteristic x rays from elemental and alloy targets irradiated by a 200-MeV negative-hydrogen beam. In most cases the entry surface, which was bombarded by both electrons and protons, gave about a factor of 2 higher yield than the exit surface where the stripped protons emerged. The results suggest a method of measuring beam profiles where particle densities are too low to be detected electrically by wire arrays. 6 refs., 4 figs.

  10. Measurements of spallation neutrons from a thick lead target bombarded with 0.5 and 1.5 GeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Meigo, Shin-ichiro; Takada, Hiroshi; Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1997-03-01

    Double differential neutron spectra from a thick lead target bombarded with 0.5 and 1.5 GeV protons have been measured with the time-of-flight technique. In order to obtain the neutron spectra without the effect of the flight time fluctuation by neutron scattering in the target, an unfolding technique has also been employed in the low energy region below 3 MeV. The measured data have been compared with the calculated results of NMTC/JAERI-MCNP-4A code system. It has been found that the code system gives about 50 % lower neutron yield than the experimental ones in the energy region between 20 and 80 MeV for both incident energies. The disagreements, however, have been improved well by taking account of the inmedium nucleon-nucleon scattering cross sections in the NMTC/JAERI code. (author)

  11. Photon emission produced by Kr{sup +} ions bombardment of Cr and Cr{sub 2}O{sub 3} targets

    Energy Technology Data Exchange (ETDEWEB)

    Boujlaidi, A. El, E-mail: a.elboujlaidi@uca.ma [Equipe de Spectroscopie and Imagerie Atomiques des Matériaux, Université Cadi Ayyad, Marrakech (Morocco); Hammoum, K. [Laboratoire de Mécanique, Structures et Energétique, Université Mouloud Mammeri de Tizi-Ouzou (Algeria); Jadoual, L.; Jourdani, R. [Equipe de Spectroscopie and Imagerie Atomiques des Matériaux, Université Cadi Ayyad, Marrakech (Morocco); Ait El Fqih, M. [Equipe de Spectroscopie and Imagerie Atomiques des Matériaux, Université Cadi Ayyad, Marrakech (Morocco); Ecole Nationale Supérieure d’Arts et Métiers (ENSAM), Université Hassan II Mohammedia – Casablanca (Morocco); Aouchiche, H. [Laboratoire de Mécanique, Structures et Energétique, Université Mouloud Mammeri de Tizi-Ouzou (Algeria); Kaddouri, A. [Equipe de Spectroscopie and Imagerie Atomiques des Matériaux, Université Cadi Ayyad, Marrakech (Morocco)

    2015-01-15

    The sputter induced photon spectroscopy technique was used to study the luminescence spectra of the species sputtered from chromium powder and its oxide Cr{sub 2}O{sub 3}, during 5 keV Kr{sup +} ions bombardment in vacuum better than 10{sup −7} torr. The optical spectra recorded between 350 and 470 nm exhibit discrete lines which are attributed to neutral excited atoms of chromium (Cr I lines). The experiments are also performed under 10{sup −5} torr ultra pure oxygen partial pressure. The results demonstrate that the measured intensities of the emitted photons are always higher in the presence of oxygen and even higher than those obtained for Cr{sub 2}O{sub 3} target. In the presence of oxygen vapor we assume that an oxide film is formed on the chromium surface which is responsible of the increase of photon emission. This variation in the intensities is correctly explained in the model of electron transfer processes between the excited sputtered atom and the bombarded surface. This model suggests that the structure formed on the Cr surface in the case of oxygenated chromium is closer to that of Cr{sub 2}O{sub 3} oxide.

  12. Experimental study on neutronics in bombardment of thick targets by high energy proton beams for accelerator-driven sub-critical system

    CERN Document Server

    Guo Shi Lun; Shi Yong Qian; Shen Qing Biao; Wan Jun Sheng; Brandt, R; Vater, P; Kulakov, B A; Krivopustov, M I; Sosnin, A N

    2002-01-01

    The experimental study on neutronics in the target region of accelerator-driven sub-critical system is carried out by using the high energy accelerator in Joint Institute for Nuclear Research, Dubna, Russia. The experiments with targets U(Pb), Pb and Hg bombarded by 0.533, 1.0, 3.7 and 7.4 GeV proton beams show that the neutron yield ratio of U(Pb) to Hg and Pb to Hg targets is (2.10 +- 0.10) and (1.76 +- 0.33), respectively. Hg target is disadvantageous to U(Pb) and Pb targets to get more neutrons. Neutron yield drops along 20 cm thick targets as the thickness penetrated by protons increases. The lower the energy of protons, the steeper the neutron yield drops. In order to get more uniform field of neutrons in the targets, the energy of protons from accelerators should not be lower than 1 GeV. The spectra of secondary neutrons produced by different energies of protons are similar, but the proportion of neutrons with higher energy gradually increases as the proton energy increases

  13. Influence of energetic ion bombardment on W-C : H coatings deposited with W and WC targets

    NARCIS (Netherlands)

    Strondl, C.; Carvalho, N.M.; de Hosson, J.T.M.; Krug, T.G.

    2005-01-01

    Tungsten containing diamond-like carbon (W-C:H) coatings have been produced by unbalanced magnetron sputtering using two different target materials. In the first series of coatings, W has been used as target material, and in the second series, WC has been used as target material. In both series of

  14. On_the_implementation_of_the_conditions_of_Inertial_Confinement_ Fusion by bombarding the target a macro particle

    CERN Document Server

    Dolya, S N

    2013-01-01

    The acceleration of lithium tube segments with the length one centimeter, diameter sixteen microns wall thickness one nanometer is considered. These segments are electrically charged by proton beams produced by an electron beam source. Then, they are accelerated by the traveling wave field in a spiral waveguide. The segments are next sent to a target where they are compressed by three hundred times in the longitudinal direction and compressing target radially, so the conditions for thermonuclear fusion are realized.

  15. Measurements of activation reaction rate distributions on a mercury target bombarded with high-energy protons at AGS

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Hiroshi; Kasugai, Yoshimi; Nakashima, Hiroshi; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ino, Takashi; Kawai, Masayoshi [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Jerde, Eric; Glasgow, David [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2000-02-01

    A neutronics experiment was carried out using a thick mercury target at the Alternating Gradient Synchrotron (AGS) facility of Brookhaven National Laboratory in a framework of the ASTE (AGS Spallation Target Experiment) collaboration. Reaction rate distributions around the target were measured by the activation technique at incident proton energies of 1.6, 12 and 24 GeV. Various activation detectors such as the {sup 115}In(n,n'){sup 115m}In, {sup 93}Nb(n,2n){sup 92m}Nb, and {sup 209}Bi(n,xn) reactions with threshold energies ranging from 0.3 to 70.5 MeV were employed to obtain the reaction rate data for estimating spallation source neutron characteristics of the mercury target. It was found from the measured {sup 115}In(n,n'){sup 115m}In reaction rate distribution that the number of leakage neutrons becomes maximum at about 11 cm from the top of hemisphere of the mercury target for the 1.6-GeV proton incidence and the peak position moves towards forward direction with increase of the incident proton energy. The similar result was observed in the reaction rate distributions of other activation detectors. The experimental procedures and a full set of experimental data in numerical form are summarized in this report. (author)

  16. Evaluation of computational models and cross sections used by MCNP6 for simulation of characteristic X-ray emission from thick targets bombarded by kiloelectronvolt electrons

    Energy Technology Data Exchange (ETDEWEB)

    Poškus, A., E-mail: andrius.poskus@ff.vu.lt

    2016-09-15

    This paper evaluates the accuracy of the single-event (SE) and condensed-history (CH) models of electron transport in MCNP6.1 when simulating characteristic K{sub α}, total K (=K{sub α} + K{sub β}) and L{sub α} X-ray emission from thick targets bombarded by electrons with energies from 5 keV to 30 keV. It is shown that the MCNP6.1 implementation of the CH model for the K-shell impact ionization leads to underestimation of the K yield by 40% or more for the elements with atomic numbers Z < 15 and overestimation of the K{sub α} yield by more than 40% for the elements with Z > 25. The L{sub α} yields are underestimated by more than an order of magnitude in CH mode, because MCNP6.1 neglects X-ray emission caused by electron-impact ionization of L, M and higher shells in CH mode (the L{sub α} yields calculated in CH mode reflect only X-ray fluorescence, which is mainly caused by photoelectric absorption of bremsstrahlung photons). The X-ray yields calculated by MCNP6.1 in SE mode (using ENDF/B-VII.1 library data) are more accurate: the differences of the calculated and experimental K yields are within the experimental uncertainties for the elements C, Al and Si, and the calculated K{sub α} yields are typically underestimated by (20–30)% for the elements with Z > 25, whereas the L{sub α} yields are underestimated by (60–70)% for the elements with Z > 49. It is also shown that agreement of the experimental X-ray yields with those calculated in SE mode is additionally improved by replacing the ENDF/B inner-shell electron-impact ionization cross sections with the set of cross sections obtained from the distorted-wave Born approximation (DWBA), which are also used in the PENELOPE code system. The latter replacement causes a decrease of the average relative difference of the experimental X-ray yields and the simulation results obtained in SE mode to approximately 10%, which is similar to accuracy achieved with PENELOPE. This confirms that the DWBA inner

  17. Measurements of production cross sections of {sup 10}Be and {sup 26}Al by 120 GeV and 392 MeV proton bombardment of {sup 89}Y, {sup 159}Tb, and {sup nat}Cu targets

    Energy Technology Data Exchange (ETDEWEB)

    Sekimoto, S.; Okumura, S.; Yashima, H. [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan); Matsushi, Y. [Disaster Prevention Research Institute, Kyoto University, Uji, Kyoto 611-0011 (Japan); Matsuzaki, H. [Department of Nuclear Engineering and Management, School of Engineering, University of Tokyo, Bunkyo, Tokyo 113-0032 (Japan); Matsumura, H.; Toyoda, A. [High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Oishi, K. [Shimizu Corporation, Ecchujima, Tokyo 135-8530 (Japan); Matsuda, N.; Kasugai, Y. [Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Sakamoto, Y. [ATOX Co., Ltd., Kashiwa, Chiba 277-0861 (Japan); Nakashima, H. [Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Boehnlein, D.; Coleman, R.; Lauten, G.; Leveling, A.; Mokhov, N.; Ramberg, E.; Soha, A.; Vaziri, K. [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); and others

    2015-10-15

    The production cross sections of {sup 10}Be and {sup 26}Al were measured by accelerator mass spectrometry using {sup 89}Y, {sup 159}Tb, and {sup nat}Cu targets bombarded by protons with energies E{sub p} of 120 GeV and 392 MeV. The production cross sections obtained for {sup 10}Be and {sup 26}Al were compared with those previously reported using E{sub p} = 50 MeV–24 GeV and various targets. It was found that the production cross sections of {sup 10}Be monotonically increased with increasing target mass number when the proton energy was greater than a few GeV. On the other hand, it was also found that the production cross sections of {sup 10}Be decreased as the target mass number increased from that of carbon to those near the mass numbers of nickel and zinc when the proton energy was below approximately 1 GeV. They also increased as the target mass number increased from near those of nickel and zinc to that of bismuth, in the same proton energy range. Similar results were observed in the production cross sections of {sup 26}Al, though the absolute values were quite different between {sup 10}Be and {sup 26}Al. The difference between these production cross sections may depend on the impact parameter (nuclear radius) and/or the target nucleus stiffness.

  18. Measurement of neutron spectra generated from bombardment of 4 to 24 MeV protons on a thick ⁹Be target and estimation of neutron yields.

    Science.gov (United States)

    Paul, Sabyasachi; Sahoo, G S; Tripathy, S P; Sharma, S C; Ramjilal; Ninawe, N G; Sunil, C; Gupta, A K; Bandyopadhyay, T

    2014-06-01

    A systematic study on the measurement of neutron spectra emitted from the interaction of protons of various energies with a thick beryllium target has been carried out. The measurements were carried out in the forward direction (at 0° with respect to the direction of protons) using CR-39 detectors. The doses were estimated using the in-house image analyzing program autoTRAK_n, which works on the principle of luminosity variation in and around the track boundaries. A total of six different proton energies starting from 4 MeV to 24 MeV with an energy gap of 4 MeV were chosen for the study of the neutron yields and the estimation of doses. Nearly, 92% of the recoil tracks developed after chemical etching were circular in nature, but the size distributions of the recoil tracks were not found to be linearly dependent on the projectile energy. The neutron yield and dose values were found to be increasing linearly with increasing projectile energies. The response of CR-39 detector was also investigated at different beam currents at two different proton energies. A linear increase of neutron yield with beam current was observed.

  19. Direct and Recoil-Induced Electron Emission from Ion-Bombarded Solids

    DEFF Research Database (Denmark)

    Holmen, G.; Svensson, B.; Schou, Jørgen

    1979-01-01

    The kinetic emission of secondary electrons from ion-bombarded solid surfaces is split into two contributions, a direct one caused by ionizing collisions between the bombarding ion and target atoms, and an indirect one originating from ionizing collisions undergone by recoil atoms with other target...... atoms. The direct contribution, which has been treated by several authors in previous studies, shows a behavior that is determined primarily by the electronic stopping power of the bombarding ion, while the indirect contribution is nonproportionally related to the nuclear stopping power. This latter...... contribution is known to be quite important for heavy-ion bombardment at keV energies, and is shown to be of crucial importance for the understanding of the energy dependence of the electron yield in such cases. The model is shown to give consistent results for copper bombarded with electrons, protons...

  20. Ion bombardment in RF photoguns

    Energy Technology Data Exchange (ETDEWEB)

    Pozdeyev,E.; Kayran, D.; Litvinenko, V. N.

    2009-05-04

    A linac-ring eRHIC design requires a high-intensity CW source of polarized electrons. An SRF gun is viable option that can deliver the required beam. Numerical simulations presented elsewhere have shown that ion bombardment can occur in an RF gun, possibly limiting lifetime of a NEA GaAs cathode. In this paper, we analytically solve the equations of motion of ions in an RF gun using the ponderomotive potential of the Rf field. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper discusses possible mitigation techniques that can reduce the rate of ion bombardment.

  1. Studying liposomes by tritium bombardment.

    Science.gov (United States)

    Kordyukova, L V; Ksenofontov, A L; Badun, G A; Baratova, L A; Shishkov, A V

    2001-12-01

    Bilayer liposomes from a mixture of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine (DPPC: DPPE = 8:2, molar ratio) or DPPC labeled with 14C-DPPC (DPPC: 14C-DPPC) were bombarded with thermally activated tritium atoms. The tritiated liposomes were hydrolyzed by phospholipase C, and the tritium incorporation into different parts of the bilayer along its thickness was determined. The tritium flux attenuation coefficients were calculated for the headgroup (k1 = 0.176+/-0.032 A(-1)) and acylglycerol residue (k2 = 0.046+/-0.004 A(-1)) layers indicating a preferential attenuation of the tritium flux in the headgroup region and relative transparence of the membrane hydrophobic part. The finding is potentially important to apply tritium bombardment for investigation of spatial organization of transmembrane proteins in their native lipid environment.

  2. Polityczna aktywność Polaków na Litwie

    Directory of Open Access Journals (Sweden)

    Marcin Wakar

    2015-12-01

    Full Text Available Political activity of Poles in Lithuania A review of the latest book by Adam Bobryk has the aim to present the most valuable points of the publication. The reviewer focuses his attention on the most important aspects described in the seven chapters of the book. He also observes that this is the first monograph describing political activities of the Polish community in the Republic of Lithuania. According to the author of the review the book by Adam Bobryk, despite a few insignificant errors, is an important position to read, and for any researcher of Polish-Lithuanian relations it is even mandatory.   Polityczna aktywność Polaków na Litwie Tekst jest recenzją najnowszej książki Adama Bobryka, w której autor stara się pokrótce przedstawić najważniejsze informacje zawarte w omawianej publikacji. Przytoczone zostały tu główne wątki opisane w siedmiu rozdziałach książki A. Bobryka. Recenzent zauważa też, że jest to pierwsza monografia opisująca działalność polityczną społeczności polskiej w Republice Litewskiej. Zdaniem autora recenzji książka Adama Bobryka, mimo kilku nieistotnych błędów, jest pozycją ważną, a dla badacza relacji polsko-litewskich wręcz obowiązkową.

  3. Direct evidence for a thermal effect of Ar/sup +/ ion bombardment in a conventional sputtering mode

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, F.; Fujimoto, Y.

    1986-03-01

    Evidence is presented that the Ar/sup +/ ion bombardment for sputtering in Auger electron spectroscopy can heat the target up to 2000 /sup 0/C if the target has poor heat conduction. Polycrystalline microneedles of Cr exhibited spherical tips after being exposed to 3 keV Ar/sup +/ ions, proving that the needle tips were melted by impacting Ar/sup +/ ions. Microneedles of Mo ion bombarded under the same condition were bent plastically, which perhaps reflects the thermal annealing of the needles during ion bombardment.

  4. Transgenic sorghum plants via microprojectile bombardment.

    OpenAIRE

    Casas, A M; Kononowicz, A K; Zehr, U B; Tomes, D T; Axtell, J. D.; Butler, L. G.; Bressan, R. A.; Hasegawa, P M

    1993-01-01

    Transgenic sorghum plants have been obtained after microprojectile bombardment of immature zygotic embryos of a drought-resistant sorghum cultivar, P898012. DNA delivery parameters were optimized based on transient expression of R and C1 maize anthocyanin regulatory elements in scutellar cells. The protocol for obtaining transgenic plants consists of the delivery of the bar gene to immature zygotic embryos and the imposition of bialaphos selection pressure at various stages during culture, fr...

  5. BADANIA PRĘDKOŚCI POJAZDÓW NA WLOTACH SKRZYŻOWAŃ BEZ SYGNALIZACJI ŚWIETLNEJ

    Directory of Open Access Journals (Sweden)

    Robert ZIÓŁKOWSKI

    2016-07-01

    Full Text Available W terenach zurbanizowanych w obszarze skrzyżowań drogowych dochodzi do koncentracji zdarzeń drogowych. Mimo projektowania skrzyżowań z sygnalizacją świetlną w celu poprawy bezpieczeństwa ruchu drogowego, to zdecydowana większość skrzyżowań w miastach funkcjonuje bez sygnalizacji. Od wielu lat jako jedną z podstawowych przyczyn dla jakich dochodzi do zdarzeń drogowych pozostaje prędkość. Celem referatu jest analiza prędkości pojazdów na wlotach skrzyżowań bez sygnalizacji świetlnej z uwzględnieniem charakterystyki odcinka dojazdowego, kierunku jazdy przez skrzyżowanie oraz wielkości promienia wyokrąglającego. Dodatkowo przeanalizowano średnie prędkości pojazdów na przejściach dla pieszych zlokalizowanych na wlotach nadrzędnych. Przeanalizowano prędkości pojazdów w warunkach ruchu swobodnego na 14 skrzyżowaniach zlokalizowanych w Białymstoku. Pomiary prowadzono wykorzystując metodę pojazdu testowego z wykorzystaniem rejestratora danych GPS. W wyniku przeprowadzonych badań wykazano istotne różnice pomiędzy średnimi prędkościami w zależności od relacji skrętnej. Dodatkowo wykazano istotność wpływu przekroju poprzecznego wlotu na średnią prędkość przejazdu przy wykonywaniu relacji prawoskrętnych. Przy relacjach lewoskrętnych takiego wpływu nie stwierdzono. Przeprowadzone analizy prędkości na przejściach dla pieszych wskazały, istotny wpływ odsunięcia przejścia od skrajnego pasa ruchu poprzecznej drogi na wzrost prędkości.

  6. Ocena wpływu systemu technologicznego oczyszczania ścieków na charakterystykę osadu czynnego

    Directory of Open Access Journals (Sweden)

    Izabela Płonka

    2017-09-01

    Full Text Available W przypadku oczyszczania ścieków komunalnych stosowane są procesy biologiczne. Procesy te mogą być realizowane w urządzeniach o różnych rozwiązaniach konstrukcyjnych. W artykule przedstawiono wyniki badań mające na celu określenie wpływu rodzaju systemu technologicznego oczyszczania ścieków na charakterystykę i właściwości osadu czynnego. Zastosowano dwa układy badawcze: przepływowy bioreaktor z wydzielonym osadnikiem (układ I oraz reaktor porcjowy SBR (układ II. Przeprowadzone badania wykazały, że korzystniejsze warunki pracy osadu czynnego panowały w reaktorze SBR. Osad pochodzący z reaktora SBR miał lepsze właściwości sedymentacyjne, na co wskazują uzyskane wartości indeksu objętościowego osadu oraz wielkości kłaczków. W reaktorze SBR nie ma konieczności przepompowywania osadu z osadnika do komory, co ma miejsce w bioreaktorze. W związku z tym osad nie jest poddawany niekorzystnym warunkom podczas transportu hydraulicznego i nie ulega rozdrobieniu. Ponadto wielkości kłaczków, aktywność oddechowa oraz powierzchnia właściwa osadu czynnego pochodzącego z układu II były większe w porównaniu z układem I.

  7. Theoretical simulations of atomic and polyatomic bombardment of an organic overlayer on a metallic substrate

    CERN Document Server

    Krantzman, K D; Delcorte, A; Garrison, B J

    2003-01-01

    Our previous molecular dynamics simulations on initial test systems have laid the foundation for understanding some of the effects of polyatomic bombardment. In this paper, we describe simulations of the bombardment of a more realistic model system, an overlayer of sec-butyl-terminated polystyrene tetramers on a Ag left brace 1 1 1 right brace substrate. We have used this model system to study the bombardment with Xe and SF sub 5 projectiles at kinetic energies ranging from 0.50 to 5.0 keV. SF sub 5 sputters more molecules than Xe, but a higher percentage of these are damaged rather than ejected intact when the bombarding energy is greater than 0.50 keV. Therefore, at energies comparable to experimental values, the efficiency, measured as the yield-to-damage ratio, is greater with Xe than SF sub 5. Stable and intact molecules are generally produced by upward moving substrate atoms, while fragments are produced by the upward and lateral motion of reflected projectile atoms and fragments from the target molecul...

  8. Self-heating effect induced by ion bombardment on polycrystalline ...

    Indian Academy of Sciences (India)

    to the self-heating effect by energy exchange between incident ions and Al surface, and the suppression by conti- nuous ion bombardment with a .... The temperature of the water-cooled substrate holder was fixed at 15. ◦. C. The Ar. + ... as the interaction between continuous ion bombardment and isotropic diffusion on the ...

  9. Beyond Bombardment: Subjectivity, Visual Culture, and Art Education

    Science.gov (United States)

    Eisenhauer, Jennifer F.

    2006-01-01

    Beginning with an understanding of visual culture as a postmodern discourse, this article argues for more focused attention to how visual culture presents a critical rethinking of subjectivity within art education. Through an analysis of a language of bombardment, a discourse that positions the subject as bombarded by media messages, this article…

  10. A low-voltage, high-current, ion-bombardment source using magnetron principles

    Energy Technology Data Exchange (ETDEWEB)

    Ja' fer, H.A.; Howson, R.P. (Loughborough Univ of Technology (United Kingdom). Dept. of Physics)

    The operation of an unbalanced magnetron under conditions using extra electron injection is shown to be a source of plasma beam which can give a substrate a self-bias of between 25 and 100 V, and allow total ion-currents of over one ampere to be drawn to a target. The use of the device to give low-energy, ion-bombardment of a growing films and to form a dense plasma source for low voltage sputtering is reported. (Author).

  11. The ballistic performance of the bombard Mons Meg

    Directory of Open Access Journals (Sweden)

    Ian Lewtas

    2016-04-01

    Full Text Available The bombard Mons Meg, located in Edinburgh Castle, with a diameter of 19 inches (48 cm, was one of the largest calibre cannons ever built. Constructed in 1449 and presented to King James II of Scotland in 1454, Mons Meg was used in both military and ceremonial roles in Scotland until its barrel burst in 1680. This paper examines the history, internal, external and terminal ballistics of the cannon and its shot. The likely muzzle velocity was estimated by varying the propellant type and the cannon profile was investigated to identify weak spots in the design that may have led to its failure. Using the muzzle velocity calculated from the internal ballistics, simulations were performed with granite and sandstone shot for varying launch angle and ground temperature. The likely trajectory and range of the cannonballs are described. The internal and external ballistics informed the initial conditions of the terminal ballistic impact scenarios. The performance of the cannonball against both period and modern targets, in the form of a pseudo-castle wall and a monolithic concrete target, respectively, were simulated and are presented and discussed.

  12. Transgenic sorghum plants via microprojectile bombardment.

    Science.gov (United States)

    Casas, A M; Kononowicz, A K; Zehr, U B; Tomes, D T; Axtell, J D; Butler, L G; Bressan, R A; Hasegawa, P M

    1993-12-01

    Transgenic sorghum plants have been obtained after microprojectile bombardment of immature zygotic embryos of a drought-resistant sorghum cultivar, P898012. DNA delivery parameters were optimized based on transient expression of R and C1 maize anthocyanin regulatory elements in scutellar cells. The protocol for obtaining transgenic plants consists of the delivery of the bar gene to immature zygotic embryos and the imposition of bialaphos selection pressure at various stages during culture, from induction of somatic embryogenesis to rooting of regenerated plantlets. One in about every 350 embryos produced embryogenic tissues that survived bialaphos treatment; six transformed callus lines were obtained from three of the eight sorghum cultivars used in this research. Transgenic (T0) plants were obtained from cultivar P898012 (two independent transformation events). The presence of the bar and uidA genes in the T0 plants was confirmed by Southern blot analysis of genomic DNA. Phosphinothricin acetyltransferase activity was detected in extracts of the T0 plants. These plants were resistant to local application of the herbicide Ignite/Basta, and the resistance was inherited in T1 plants as a single dominant locus.

  13. Actinide production from xenon bombardments of curium-248

    Energy Technology Data Exchange (ETDEWEB)

    Welch, R.B.

    1985-01-01

    Production cross sections for many actinide nuclides formed in the reaction of /sup 129/Xe and /sup 132/Xe with /sup 248/Cm at bombarding energies slightly above the coulomb barrier were determined using radiochemical techniques to isolate these products. These results are compared with cross sections from a /sup 136/Xe + /sup 248/Cm reaction at a similar energy. When compared to the reaction with /sup 136/Xe, the maxima in the production cross section distributions from the more neutron deficient projectiles are shifted to smaller mass numbers, and the total cross section increases for the production of elements with atomic numbers greater than that of the target, and decreases for lighter elements. These results can be explained by use of a potential energy surface (PES) which illustrates the effect of the available energy on the transfer of nucleons and describes the evolution of the di-nuclear complex, an essential feature of deep-inelastic reactions (DIR), during the interaction. The other principal reaction mechanism is the quasi-elastic transfer (QE). Analysis of data from a similar set of reactions, /sup 129/Xe, /sup 132/Xe, and /sup 136/Xe with /sup 197/Au, aids in explaining the features of the Xe + Cm product distributions, which are additionally affected by the depletion of actinide product yields due to deexcitation by fission. The PES is shown to be a useful tool to predict the general features of product distributions from heavy ion reactions.

  14. Stable Transformation of the Saintpaulia ionantha by Particle Bombardment.

    Science.gov (United States)

    Ghorbanzade, Zahra; Ahmadabadi, Mohammad

    2015-03-01

    A highly efficient genetic transformation system is essential for a successful genetic manipulation of the African violet (Saintpaulia ionantha Wendl.). Developing a particle bombardment-based genetic transformation system for the African violet. A local cultivar of the African violet from Guilan province was used for transformation experiments. The pFF19G and pBin61-Ech42 vectors were used for transient and stable transformation experiments, respectively. The PCR and RT-PCR techniques were used to verify transgene presence and transcript levels in candidate transgenic lines, respectively. Using leaf explants as target tissues, we transferred an endochitinase gene cDNA into African violet. Transgenic plants were regenerated on selection medium at a reasonable frequency (in average, one stable transgenic line per shot). Molecular analysis of transgenic plants by PCR and RT-PCR techniques confirmed successful integration and expression of transgene in several independent transgenic lines. Our results provide an efficient stable transformation system for genetic transformation of African violet.

  15. Computer simulation of chemical erosion of graphite due to hydrogen ion bombardment

    CERN Document Server

    Liang, J H; Roth, J; Eckstein, W

    2003-01-01

    Chemical erosion of graphite due to hydrogen ion bombardment has been investigated theoretically by applying a model of chemical erosion to the TRIDYN code. The model involves the formation of methane at the end of the ion track as well as the kinetic emission of hydrocarbons from the target surface. Model calculations were performed for ion energies ranging from 10 to 1000 eV and at target temperatures ranging from 300 to 900 K. Good agreement between calculated and measured erosion yields is obtained.

  16. Importance of ion bombardment during coverage of Au nanoparticles on their structural features and optical response

    Energy Technology Data Exchange (ETDEWEB)

    Resta, V.; Peláez, R. J.; Afonso, C. N. [Laser Processing Group, Instituto de Óptica, CSIC, Serrano 121, E-28006 Madrid (Spain)

    2014-03-28

    This work studies the changes in the optical response and morphological features of 6 ± 1 nm diameter Au nanoparticles (NPs) when covered by a layer of a-Al{sub 2}O{sub 3} by pulsed laser deposition (PLD). The laser fluence used for ablating the Al{sub 2}O{sub 3} target is varied in order to modify the kinetic energy (KE) of the species bombarding the NPs during their coverage. When the ion KE < 200 eV, the structural features and optical properties of the NPs are close to those of uncovered ones. Otherwise, a shift to the blue and a strong damping of the surface plasmon resonance is observed as fluence is increased. There are two processes responsible for these changes, both related to aluminum ions arriving to the substrate during the coverage process, i.e., sputtering of the metal and implantation of aluminum species in the metal. Both processes have been simulated using standard models for ion bombardment, the calculated effective implanted depths allow explaining the observed changes in the optical response, and the use of a size-dependent sputtering coefficient for the Au NPs predicts the experimental sputtering fractions. In spite of the work is based on PLD, the concepts investigated and conclusions can straightforwardly be extrapolated to other physical vapor deposition techniques or processes involving ion bombardment of metal NPs by ions having KE > 200 eV.

  17. Heavy-ion induced desorption yields of cryogenic surfaces bombarded with 4.2 MeV/u lead ions

    CERN Document Server

    Mahner, E; Evans, L; Kollmus, H; Küchler, D; Scrivens, R; Severin, D; Wengenroth, M; CERN. Geneva. ATS Department

    2011-01-01

    The ion-induced desorption experiment, installed in the CERN Heavy-Ion Accelerator LINAC 3, has been used to study the dynamic outgassing of cryogenic surfaces. Two different targets, bare and goldcoated copper, were bombarded under perpendicular impact with 4.2 MeV/u Pb54+ ions. Partial pressure rises of H2, CH4, CO, and CO2 and effective desorption yields were measured at 300, 77, and 6.3 K using single shot and continuous ion bombardment techniques. We find that the heavy-ion-induced desorption yield is temperature dependent and investigate the influence of CO gas cryosorbed at 6.3 K. The gain in desorption yield reduction at cryogenic temperature vanishes after several monolayers of CO are cryosorbed on both targets. In this paper we describe the new cryogenic target assembly, the temperature-dependent pressure rise, desorption yield, and gas adsorption measurements.

  18. Microprojectile Bombardment Transformation of Date Palm Using the Insecticidal Cholesterol Oxidase (ChoA) Gene.

    Science.gov (United States)

    Allam, Mai A; Saker, Mahmoud M

    2017-01-01

    The overall objective of this work is to optimize the transformation system for date palm as a first step toward production of date palm clones resistant to noxious pests. A construct harboring the cholesterol oxidase (ChoA) gene, which renders plant resistance against insect attack, is introduced into embryogenic date palm callus using the PDS-1000/He particle bombardment system. The process involves the establishment of embryogenic callus cultures as well as immature embryo-derived microcalli that are used as target tissues for shooting and optimization of transformation conditions. This chapter in addition explains molecular and histochemical assays conducted to confirm gene integration and expression.

  19. Turystyka religijna na przykładzie sanktuarium Relikwii Drzewa Krzyża Św. na Świętym Krzyżu

    OpenAIRE

    Mróz Franciszek

    2003-01-01

    Sanktuarium Relikwii Drzewa Krzyża Świętego na Świętym Krzyżu należy do naj-starszych ośrodków pielgrzymkowych w Polsce. Ośrodek ten uznawany jest za pierwsze narodowe sanktuarium Polski i rangę taką pełnił do cudownej obrony Jasnej Góry w 1655 r. W ostatnich latach sanktuarium na Świętym Krzyżu odwiedza około 160 tys. osób. Klasztor benedyktynów na Łysej Górze zasłynął w całym kraju już w średniowieczu, dzięki relikwiom Krzyża Świętego. Najprawdopodobniej benedyktyni otrzymali relikwiarz ...

  20. Fast atom bombardment mass spectrometry of condensed tannin sulfonate derivatives

    Science.gov (United States)

    J.J. Karchesy; L.Y. Foo; Richard W. Hemingway; E. Barofsky; D.F. Barofsky

    1989-01-01

    Condensed tannin sulfonate derivatives were studied by fast atom bombardment mass spectrometry (FAB-MS) to assess the feasibility of using this technique for determining molecular weight and structural information about these compounds. Both positive- and negative-ion spectra provided useful data with regard to molecular weight, cation species present, and presence of...

  1. Protons from the alpha-particle bombardment of 31P

    NARCIS (Netherlands)

    Kuperus, J.

    Resonances in the yield of ground-state protons from alpha-particle bombardment of 31P were investigated in the energy range Eα = 1.7 − 3.3 MeV. Fourteen resonances were observed, none of which was known before. Resonance energies and strengths are presented. Angular distribution measurements lead

  2. Protons from the alpha-particle bombardment of 23Na

    NARCIS (Netherlands)

    Kuperus, J.

    1964-01-01

    Resonances in the yield of ground-state protons from alpha-particle bombardment of 23Na were investigated in the energy range Eα = 1.0 – 3.3 MeV. At least thirty-eight resonances were observed. Resonance energies and strengths are presented. At nine resonances angular distribution measurements lead

  3. Fundamentals for magnetic patterning by ion bombardment of exchange bias layer systems

    Science.gov (United States)

    Ehresmann, A.; Engel, D.; Weis, T.; Schindler, A.; Junk, D.; Schmalhorst, J.; Höink, V.; Sacher, M. D.; Reiss, G.

    2006-01-01

    In the present paper we investigate whether the ion bombardment induced magnetic modifications in exchange biased bilayers are stable in time, whether the direction of the exchange bias can be set to any arbitrary (in-plane) direction by the ion bombardment and whether the exchange bias field can be changed in successive bombardment steps. These three fundamental characteristics are prerequisites for ion bombardment used for an efficient, practical, and stable magnetic patterning of exchange biased layer systems.

  4. Photon and secondary ion emission from keV cluster bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, R.G. [Texas A& M Univ., College Station, TX (United States)

    1994-12-31

    CsI clusters (Cs{sub n}I{sup {minus}}{sub n+1} n = 0 to 4) in the keV energy range (15 to 45 keV) have been used to bombard CsI targets in time-of-flight mass spectrometry experiments to study the relationships between secondary ion and photon emissions. Single ions and photons were detected simultaneously from the impact of single projectiles. The secondary ion yields from the polyatomic projectiles are proportional to the projectile momentum. The photon yields are roughly proportional to both the electronic and the nuclear stopping powers. The photon emission from the bulk of the CsI targets is attributed to excitonic processes.

  5. Surface chemical reactions induced on pyrite by ion bombardment

    Science.gov (United States)

    Ruano, Gustavo; Pomiro, Fernando; Ferrón, Julio

    2018-01-01

    Through X-ray photoemission spectroscopy (XPS), we studied the chemical changes induced in a natural crystal of pyrite (FeS2) upon exposure to 4.5 keV He+ beam. We found an important reducing effect induced by ion bombardment leading to the production of iron embedded in the pyrite matrix. Through a combination of the usual Doniach-Sunjic treatment and Factor Analysis of XPS yields, we were able of analyzing the full Fe 2p XPS signal. We could in this way distinguish Fe compounds with the same binding energy for the Fe 2p3/2 yield. Our results show that He+ bombardment disrupts the ionic environment producing S2-2 and S0, Fe2+ and Fe3+ ions, and the reduction to metallic iron. The remaining pyrite matrix does not passivate the embedded iron structures, which are readily oxidized under air exposure. The oxide formed resembled that of magnetite from the XPS point of view. Further He+ bombardment proved to be efficient to reduce the iron oxide back to iron again.

  6. Low energy electron bombardment induced surface contamination of Ru mirrors

    Science.gov (United States)

    Al-Ajlony, A.; Kanjilal, A.; Catalfano, M.; Harilal, S. S.; Hassanein, A.; Rice, B.

    2012-03-01

    The impact of secondary electrons induced contamination of the Ru surface was investigated. Mirror-like Ru sample was bombarded with low energy (100 eV) electrons and the change in surface chemistry was investigated using X-ray photoelectron spectroscopy (XPS).Along with XPS studies the corresponding effect on in-situ EUV reflectivity was examined by exposing the Ru surface to photons at a wavelength of 13.5 nm in an ultrahigh vacuum chamber. Detailed XPS analyses showed a sudden increase in carbon concentrations on the Ru surface in the first 60 min, followed by a slow but linear growth in carbon concentration. In parallel, a noticeable decrease in water content was observed during the time of electrons irradiation along with slight oxidation of pure Ru surface. All chemical changes were discussed in terms of the electrons bombardment mediated dissociation of water and hydrocarbon molecules. A time dependent EUV reflectivity measurements show insignificant change in reflectivity up to 510 min of electrons bombardment. The impact of water molecules on the Ru surface and the accumulation of carbon through dissociation of residual hydrocarbons is discussed in details.

  7. Fracture toughness and leaching behavior of ion bombarded waste glasses

    Science.gov (United States)

    Matzke, Hj.; Linker, G.

    1984-02-01

    Fracture toughness Klc and fracture surface energy γ were measured on borosilicate waste glasses containing simulated fission products produced in the Institut für Nukleare Entsorgung, KFK. The Hertzian indentation technique with spherical indenters was shown to be a very powerful means with which to study mechanical and fracture properties of small highly radioactive samples. It was tested with Pu-ceramics as well as with Cm-doped glass ceramics. Radiation damage was produced by ion bombardment with Pb or Xe ions of energies up to 300 keV or with He 2+-ions (α-particles) of the cyclotron (KFK) with energies up to 77 MeV. The glasses were used either as-received or else following high-temperature, high-pressure autoclave leaching. The as-bombarded and the leached glasses were analyzed for surface composition and changes by Rutherford backscattering, RBS, with He-ions. In many cases, radiation damage caused an increase in fracture toughness, a very beneficial effect. The leached glasses that were investigated contained surface layers with thicknesses of up to ˜2 μm. RBS showed these layers to be similar in composition to thick layers analyzed by electron microprobe analysis (empa). There was no drastic influence of ion bombardment on the composition or thickness of these layers. The layers themselves caused changes of about ± 10% in the apparent fracture toughness, possibly by absorbing part of the applied energy by plastic deformation or by preventing pre-existing flaws from initiating crack formation.

  8. Induction of antioxidant enzyme activity and lipid peroxidation level in ion-beam-bombarded rice seeds

    Energy Technology Data Exchange (ETDEWEB)

    Semsang, Nuananong, E-mail: nsemsang@gmail.com [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, LiangDeng [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: ► Ion beam bombarded rice seeds in vacuum. ► Studied seed survival from the ion bombardment. ► Determined various antioxidant enzyme activities and lipid peroxidation level. ► Discussed vacuum, ion species and ion energy effects. ► Attributed the changes to free radical formation due to ion bombardment. -- Abstract: Low-energy ion beam bombardment has been used to mutate a wide variety of plant species. To explore the indirect effects of low-energy ion beam on biological damage due to the free radical production in plant cells, the increase in antioxidant enzyme activities and lipid peroxidation level was investigated in ion-bombarded rice seeds. Local rice seeds were bombarded with nitrogen or argon ion beams at energies of 29–60 keV and ion fluences of 1 × 10{sup 16} ions cm{sup −2}. The activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST) and lipid peroxidation level were assayed in the germinated rice seeds after ion bombardment. The results showed most of the enzyme activities and lipid peroxidation levels in both the argon and nitrogen bombarded samples were higher than those in the natural control. N-ion bombardment could induce higher levels of antioxidant enzyme activities in the rice samples than the Ar-ion bombardment. Additional effects due to the vacuum condition were found to affect activities of some antioxidant enzymes and lipid peroxidation level. This study demonstrates that ion beam bombardment and vacuum condition could induce the antioxidant enzyme activity and lipid peroxidation level which might be due to free radical production in the bombarded rice seeds.

  9. Switchable resonant x-ray Bragg scattering on a magnetic grating patterned by ion bombardment

    Science.gov (United States)

    Höink, V.; Sacher, M. D.; Schmalhorst, J.; Reiss, G.; Engel, D.; Weis, T.; Ehresmann, A.

    2006-09-01

    A local manipulation of the exchange bias coupling between antiferromagnetic and ferromagnetic layers by ion bombardment induced magnetic patterning enables a patterning of the magnetization direction of the ferromagnetic layer without considerable structural changes. We show that a magnetic line grating with alternating antiparallel orientations of the magnetization of the ferromagnetic layer acts as a magnetically switchable reflective grating for soft x-ray radiation. A common rotational direction of the magnetization at all boundaries between bombarded and not bombarded lines is shown by magnetic force microscopy measurements. Scattering at the edges of the bombarded lines might be responsible for the observed interference pattern.

  10. Fundamentals for magnetic patterning by ion bombardment of exchange bias layer systems

    Energy Technology Data Exchange (ETDEWEB)

    Ehresmann, A.; Engel, D.; Weis, T. [Institute of Physics and Centre for Interdisciplinary Nanostructure Science and Technology (CINSaT), Kassel University, Heinrich-Plett-Str. 40, 34132 Kassel (Germany); Schindler, A. [Institut fuer Festkoerperforschung, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Junk, D. [Technische Physik, Universitaet des Saarlandes, P.O. Box 151150, 66041 Saarbruecken (Germany); Schmalhorst, J.; Hoeink, V.; Sacher, M.D.; Reiss, G. [Faculty of Physics, Bielefeld University, P.O. Box 100131, 33501 Bielefeld (Germany)

    2006-01-01

    In the present paper we investigate whether the ion bombardment induced magnetic modifications in exchange biased bilayers are stable in time, whether the direction of the exchange bias can be set to any arbitrary (in-plane) direction by the ion bombardment and whether the exchange bias field can be changed in successive bombardment steps. These three fundamental characteristics are prerequisites for ion bombardment used for an efficient, practical, and stable magnetic patterning of exchange biased layer systems. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Postannealing of magnetic tunnel junctions with ion-bombardment-modified exchange bias

    Science.gov (United States)

    Höink, V.; Sacher, M. D.; Schmalhorst, J.; Reiss, G.; Engel, D.; Junk, D.; Ehresmann, A.

    2005-04-01

    The influence of a postannealing procedure on the transport properties of magnetic tunnel junctions with ion-bombardment-manipulated exchange bias is investigated. The controlled manipulation of the direction of the exchange bias field in magnetic tunnel junctions by He ion bombardment usually is accompanied by a reduction of the tunneling magnetoresistance and an increase in the resistance. Here, we demonstrate that it is possible to reduce these negative effects of the ion bombardment considerably by postannealing without a magnetic field. For optimized combinations of ion dose and postannealing temperature, the tunneling magnetoresistance recovers completely (>50% resistance change) while the exchange bias direction set by the ion bombardement is preserved.

  12. Evidence Supporting an Early as Well as Late Heavy Bombardment on the Moon

    Science.gov (United States)

    Frey, Herbert

    2015-01-01

    Evidence supporting an intense early bombardment on the Moon in addition to the traditional Late Heavy Bombardment at approx. 4 BY ago include the distribution of N(50) Crater Retention Ages (CRAs) for candidate basins, a variety of absolute age scenarios for both a "young" and an "old" Nectaris age, and the decreasing contrasts in both topographic relief and Bouguer gravity with increasing CRA.

  13. Spontaneous Pattern Formation on Ion Bombarded Si(001)

    Energy Technology Data Exchange (ETDEWEB)

    Chason, Eric; Erlebacher, Jonah, Aziz, Michael J.; Floro, Jerrold A.; Sinclair, Michael B.

    1999-04-26

    Pattern formation on surfaces undergoing low-energy ion bombardment is a common phenomenon. Here, a recently developed in situ spectroscopic light scattering technique was used to monitor periodic ripple evolution on Si(001) during Ar(+) sputtering. Analysis of the rippling kinetics indicated that under high flux sputtering at low temperatures the concentration of mobile species on the surface is saturated, and, surprisingly, is both temperature and ion flux independent. This is due to an effect of ion collision cascades on the concentration of mobile species. This new understanding of surface dynamics during sputtering allowed us to measure straighforwardly the activation energy for atomic migration on the surface to be 1.2+0.1 eV. The technique is generalizable to any material, including high temperature and insulating materials for which surface migration energies are notoriously difficult to measure.

  14. Stable transformation of the oomycete, Phytophthora infestans, using microprojectile bombardment

    DEFF Research Database (Denmark)

    Cvitanich, Cristina; Judelson, Howard S.

    2003-01-01

    Germinated asexual sporangia, zoospores, and mycelia of Phytophthora infestans were transformed to G418-resistance by microprojectile bombardment. After optimization, an average of 14 transformants/shot were obtained, using 10(6) germinated sporangia and gold particles coated with 1 microg...... of vector. Transformants displayed tandem or simple insertions of vector sequences within chromosomes. Most primary transformants were heterokaryons of transformed and wild-type nuclei, a state which generally persisted for generations, even with G418 selection. Transgenic homokaryons were easily obtained...... from primary transformants through G418 selection of zoospores. To facilitate the optimization of transformation, experiments were performed using a vector containing neomycin phosphotransferase (npt) and beta-glucuronidase (GUS) genes fused to oomycete transcriptional regulatory sequences. To indicate...

  15. Delays in thick targets

    CERN Document Server

    Bennett, J R J

    2002-01-01

    The delays in the emission of radioactive particles from a thick target bombarded by high-energy protons is discussed in relation to the basic physical processes of diffusion and effusion through the target and ioniser. The delay time, relative to the decay time, is crucial to the efficiency of particle release at the exit of the ioniser. The principles of minimizing the delay times are discussed with reference to a mathematical model of the process, and some experimental examples are given.

  16. Enhanced End-Contacts by Helium Ion Bombardment to Improve Graphene-Metal Contacts

    Directory of Open Access Journals (Sweden)

    Kunpeng Jia

    2016-08-01

    Full Text Available Low contact resistance between graphene and metals is of paramount importance to fabricate high performance graphene-based devices. In this paper, the impact of both defects induced by helium ion (He+ bombardment and annealing on the contact resistance between graphene and various metals (Ag, Pd, and Pt were systematically explored. It is found that the contact resistances between all metals and graphene are remarkably reduced after annealing, indicating that not only chemically adsorbed metal (Pd but also physically adsorbed metals (Ag and Pt readily form end-contacts at intrinsic defect locations in graphene. In order to further improve the contact properties between Ag, Pd, and Pt metals and graphene, a novel method in which self-aligned He+ bombardment to induce exotic defects in graphene and subsequent thermal annealing to form end-contacts was proposed. By using this method, the contact resistance is reduced significantly by 15.1% and 40.1% for Ag/graphene and Pd/graphene contacts with He+ bombardment compared to their counterparts without He+ bombardment. For the Pt/graphene contact, the contact resistance is, however, not reduced as anticipated with He+ bombardment and this might be ascribed to either inappropriate He+ bombardment dose, or inapplicable method of He+ bombardment in reducing contact resistance for Pt/graphene contact. The joint efforts of as-formed end-contacts and excess created defects in graphene are discussed as the cause responsible for the reduction of contact resistance.

  17. Efficient and rapid C. elegans transgenesis by bombardment and hygromycin B selection.

    Directory of Open Access Journals (Sweden)

    Inja Radman

    Full Text Available We report a simple, cost-effective, scalable and efficient method for creating transgenic Caenorhabditis elegans that requires minimal hands-on time. The method combines biolistic bombardment with selection for transgenics that bear a hygromycin B resistance gene on agar plates supplemented with hygromycin B, taking advantage of our observation that hygromycin B is sufficient to kill wild-type C. elegans at very low concentrations. Crucially, the method provides substantial improvements in the success of bombardments for isolating transmitting strains, the isolation of multiple independent strains, and the isolation of integrated strains: 100% of bombardments in a large data set yielded transgenics; 10 or more independent strains were isolated from 84% of bombardments, and up to 28 independent strains were isolated from a single bombardment; 82% of bombardments yielded stably transmitting integrated lines with most yielding multiple integrated lines. We anticipate that the selection will be widely adopted for C. elegans transgenesis via bombardment, and that hygromycin B resistance will be adopted as a marker in other approaches for manipulating, introducing or deleting DNA in C. elegans.

  18. Compositional Evolution of Saturn's Rings Due to Meteoroid Bombardment

    Science.gov (United States)

    Cuzzi, J.; Estrada, P.; Young, Richard E. (Technical Monitor)

    1997-01-01

    In this paper we address the question of compositional evolution in planetary ring systems subsequent to meteoroid bombardment. The huge surface area to mass ratio of planetary rings ensures that this is an important process, even with current uncertainties on the meteoroid flux. We develop a new model which includes both direct deposition of extrinsic meteoritic "pollutants", and ballistic transport of the increasingly polluted ring material as impact ejecta. Our study includes detailed radiative transfer modeling of ring particle spectral reflectivities based on refractive indices of realistic constituents. Voyager data have shown that the lower optical depth regions in Saturn's rings (the C ring and Cassini Division) have darker and less red particles than the optically thicken A and B rings. These coupled structural-compositional groupings have never been explained; we present and explore the hypothesis that global scale color and compositional differences in the main rings of Saturn arise naturally from extrinsic meteoroid bombardment of a ring system which was initially composed primarily, but not entirely, of water ice. We find that the regional color and albedo differences can be understood if all ring material was initially identical (primarily water ice, based on other data, but colored by tiny amounts of intrinsic reddish, plausibly organic, absorber) and then evolved entirely by addition and mixing of extrinsic, nearly neutrally colored. plausibly carbonaceous material. We further demonstrate that the detailed radial profile of color across the abrupt B ring - C ring boundary can.constrain key unknown parameters in the model. Using new alternates of parameter values, we estimate the duration of the exposure to extrinsic meteoroid flux of this part of the rings, at least, to be on the order of 10(exp 8) years. This conclusion is easily extended by inference to the Cassini Division and its surroundings as well. This geologically young "age" is compatible

  19. Modification of the saturation magnetization of exchange bias thin film systems upon light-ion bombardment.

    Science.gov (United States)

    Huckfeldt, Henning; Gaul, Alexander; David Müglich, Nicolas; Holzinger, Dennis; Nissen, Dennis; Albrecht, Manfred; Emmrich, Daniel; Beyer, André; Gölzhäuser, Armin; Ehresmann, Arno

    2017-03-29

    The magnetic modification of exchange bias materials by 'ion bombardment induced magnetic patterning' has been established more than a decade ago. To understand these experimental findings several theoretical models were introduced. Few investigations, however, did focus on magnetic property modifications caused by effects of ion bombardment in the ferromagnetic layer. In the present study, the structural changes occurring under ion bombardment were investigated by Monte-Carlo simulations and in experiments. A strong reduction of the saturation magnetization scaling linearly with increasing ion doses is observed and our findings suggest that it is correlated to the swelling of the layer material based on helium implantation and vacancy creation.

  20. Initialization of unidirectional anisotropy in a ferromagnet antiferromagnet bilayer by keV-He ion bombardment

    Science.gov (United States)

    Engel, D.; Ehresmann, A.; Schmalhorst, J.; Sacher, M.; Höink, V.; Reiss, G.

    2005-06-01

    A polycrystalline Cu/Ni80Fe20/Mn83Ir17/Co/AlOx ferromagnet-antiferromagnet layer system grown without applying an external magnetic field shows no unidirectional anisotropy in the as-prepared state. After 10 keV-He ion bombardment in an external in-plane magnetic field, a clear unidirectional anisotropy collinear to the magnetic field direction during bombardment is observed, indicating that ion bombardment can be used for this system to initialize the unidirectional exchange anisotropy. The magnetization reversal processes for various ion doses are discussed, based on longitudinal magnetooptical Kerr-effect measurements.

  1. Hydrogen ion bombardment damage in stainless steel mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Belyaeva, A.I. [National Technical University ' KhPI' , Kharkov, 61002 Kharkov (Ukraine); Bardamid, A.F. [T. Shevchenko National University, Kiev (Ukraine); Davis, J.W. [University of Toronto Institute for Aerospace Studies, Toronto, ON, M3H 5T6 (Canada); Haasz, A.A. [University of Toronto Institute for Aerospace Studies, Toronto, ON, M3H 5T6 (Canada)]. E-mail: aahaasz@utias.utoronto.ca; Konovalov, V.G. [NSC KIPT, 61108 Kharkov (Ukraine); Kudlenko, A.D. [National Technical University ' KhPI' , Kharkov, 61002 Kharkov (Ukraine); Poon, M. [University of Toronto Institute for Aerospace Studies, Toronto, ON, M3H 5T6 (Canada); Slatin, K.A. [National Technical University ' KhPI' , Kharkov, 61002 Kharkov (Ukraine); Voitsenya, V.S. [NSC KIPT, 61108 Kharkov (Ukraine)

    2005-10-15

    Experiments have been performed to evaluate the changes in surface structure and the resulting effects on the optical properties of stainless steel due to hydrogen ion irradiation. Stainless steel (SS) is a standard material used for in-vessel components, including the first mirrors (FMs), in some current generation fusion devices. Optical microscopy, interferometry, scanning electron microscopy (SEM) and ellipsometry were used to characterize the surfaces. Results are presented for the bombardment of SS mirrors with H{sub 3}{sup +} ions having various fixed energies (0.3, 0.65, and 1.5keV/H{sup +}), with ion flux densities of (0.5-2)x10{sup 20} H{sup +}/m{sup 2}s and fluences of {approx}2.2x10{sup 24} H{sup +}/m{sup 2}. Variation of the ion energy at a constant fluence had a considerable effect on the damage structure that forms on the SS mirror surfaces. Possible mechanisms for the ion energy effect on the surface are discussed and a model of the damaged surface layer is proposed.

  2. Fast atom bombardment tandem mass spectrometry of carotenoids

    Energy Technology Data Exchange (ETDEWEB)

    van Breeman, R.B. [Univ. of Illinois, Chicago, IL (United States); Schmitz, H.H.; Schwartz, S.J. [North Carolina State Univ., Raleigh, NC (United States)

    1995-02-01

    Positive ion fast atom bombardment (FAB) tandem mass spectrometry (MS-MS) using a double-focusing mass spectrometer with linked scanning at constant B/E and high-energy collisionally activated dissociation (CAD) was used to differentiate 17 different cartenoids, including {beta}-apo-8{prime}- carotenal, astaxanthin, {alpha}-carotene, {beta}-carotene, {gamma}-carotene, {zeta}-carotene, canthaxanthin, {beta}-cryptoxanthin, isozeaxanthin bis (pelargonate), neoxanthin, neurosporene, nonaprene, lutein, lycopene, phytoene, phytofluene, and zeaxanthin. The carotenoids were either synthetic or isolated from plant tissues. The use of FAB ionization minimized degradation or rearrangement of the carotenoid structures due to the inherent thermal instability generally ascribed to these compounds. Instead of protonated molecules, both polar xanthophylls and nonpolar carotenes formed molecular ions, M{sup {center_dot}+}, during FAB ionization. Following collisionally activated dissociation, fragment ions of selected molecular ion precursors showed structural features indicative of the presence of hydroxyl groups, ring systems, ester groups, and aldehyde groups and the extent of aliphatic polyene conjugation. The fragmentation patterns observed in the mass spectra herein may be used as a reference for the structural determination of carotenoids isolated from plant and animal tissues. 18 refs., 4 figs.

  3. Back-bombardment compensation in microwave thermionic electron guns

    Directory of Open Access Journals (Sweden)

    Jeremy M. D. Kowalczyk

    2014-12-01

    Full Text Available The development of capable, reliable, and cost-effective compact electron beam sources remains a long-standing objective of the efforts to develop the accelerator systems needed for on-site research and industrial applications ranging from electron beam welding to high performance x-ray and gamma ray light sources for element-resolved microanalysis and national security. The need in these applications for simplicity, reliability, and low cost has emphasized solutions compatible with the use of the long established and commercially available pulsed microwave rf sources and L-, S- or X-band linear accelerators. Thermionic microwave electron guns have proven to be one successful approach to the development of the electron sources for these systems providing high macropulse average current beams with picosecond pulse lengths and good emittance out to macropulse lengths of 4–5 microseconds. But longer macropulse lengths are now needed for use in inverse-Compton x-ray sources and other emerging applications. We describe in this paper our approach to extending the usable macropulse current and pulse length of these guns through the use of thermal diffusion to compensate for the increase in cathode surface temperature due to back-bombardment.

  4. Modelling and simulation of surface morphology driven by ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Yewande, E.O.

    2006-05-02

    Non-equilibrium surfaces, at nanometer length scales, externally driven via bombardment with energetic particles are known to exhibit well ordered patterns with a variety of applications in nano-technology. These patterns emerge at time scales on the order of minutes. Continuum theory has been quite successful in giving a general picture of the processes that interplay to give the observed patterns, as well as how such competition might determine the properties of the nanostructures. However, continuum theoretical descriptions are ideal only in the asymptotic limit. The only other theoretical alternative, which happens to be more suitable for the characteristic length-and time-scales of pattern formation, is Monte Carlo simulation. In this thesis, surface morphology is studied using discrete solid-on-solid Monte Carlo models of sputtering and surface diffusion. The simulations are performed in the context of the continuum theories and experiments. In agreement with the experiments, the ripples coarsen with time and the ripple velocity exhibits a power-law behaviour with the ripple wavelength, in addition, the exponent was found to depend on the simulation temperature, which suggests future experimental studies of flux dependence. Moreover, a detailed exploration of possible topographies, for different sputtering conditions, corresponding to different materials, was performed. And different surface topographies e.g. holes, ripples, and dots, were found at oblique incidence, without sample rotation. With sample rotation no new topography was found, its only role being to destroy any inherent anisotropy in the system. (orig.)

  5. Hydrogen ion bombardment damage in stainless steel mirrors

    Science.gov (United States)

    Belyaeva, A. I.; Bardamid, A. F.; Davis, J. W.; Haasz, A. A.; Konovalov, V. G.; Kudlenko, A. D.; Poon, M.; Slatin, K. A.; Voitsenya, V. S.

    2005-10-01

    Experiments have been performed to evaluate the changes in surface structure and the resulting effects on the optical properties of stainless steel due to hydrogen ion irradiation. Stainless steel (SS) is a standard material used for in-vessel components, including the first mirrors (FMs), in some current generation fusion devices. Optical microscopy, interferometry, scanning electron microscopy (SEM) and ellipsometry were used to characterize the surfaces. Results are presented for the bombardment of SS mirrors with H3+ ions having various fixed energies (0.3, 0.65, and 1.5 keV/H+), with ion flux densities of (0.5-2) × 1020 H+/m2s and fluences of ∼2.2 × 1024 H+/m2. Variation of the ion energy at a constant fluence had a considerable effect on the damage structure that forms on the SS mirror surfaces. Possible mechanisms for the ion energy effect on the surface are discussed and a model of the damaged surface layer is proposed.

  6. Diamond-like carbon layers modified by ion bombardment during growth and researched by Resonant Ultrasound Spectroscopy

    Science.gov (United States)

    Kocourek, Tomáš; Jelínek, Miroslav; Písařík, Petr; Remsa, Jan; Janovská, Michaela; Landa, Michal; Zemek, Josef; Havránek, Vladimír

    2017-09-01

    Biocompatible Diamond-Like Carbon (DLC) films were prepared by Pulsed Laser Deposition technique using the laser energy density of 10 J cm-2 on the graphite target. The surface of the grown film was modified during the deposition by bombardment with argon, xenon, nitrogen or oxygen ions. The ion energy (up to 150 eV) was changed by gun voltage and by ionic current. The films with high and low diamond/graphite content were prepared. Physical and mechanical properties of biocompatible DLC thin layers prepared by hybrid laser technology were studied. The composition of layers and the content trace elements were determined by the methods of Rutherford Backscattering Spectrometry and Particle Induced X-ray Emission. The content of sp2 and sp3 bonds was measured using X-ray Photoelectron Spectroscopy. For different energy of argon and oxygen ions the maximum of sp3 bonds content was found (83.63% of sp3 bonds for argon ions). All films were smooth, which was confirmed by profilometry and Atomic Force Microscopy measurements. Maximum roughness Ra and RMS was did not exceed 1 nm. The Younǵs and shear moduli were studied by Resonant Ultrasound Spectroscopy. The Young's Modulus attained the value of 601 GPa and the shear Modulus attained the value of 253 GPa at the energy of 30 eV of Ar ions. The influence of ion bombardment on DLC film properties is discussed.

  7. The interpretation of ellipsometric measurements of ion bombardment of noble gases on semiconductor surfaces

    NARCIS (Netherlands)

    Holtslag, A.H.M.; Slager, U.C.; van Silfhout, Arend

    1985-01-01

    Low energy noble gas ion bombardment and thermal desorption studies were carried out on Si(111) and analysed, in situ, using spectroscopic ellipsometry. The amorphous layer thickness and implanted noble gas fraction were calculated.

  8. Genetic Transformation of Metroxylon sagu (Rottb. Cultures via Agrobacterium-Mediated and Particle Bombardment

    Directory of Open Access Journals (Sweden)

    Evra Raunie Ibrahim

    2014-01-01

    Full Text Available Sago palm (Metroxylon sagu is a perennial plant native to Southeast Asia and exploited mainly for the starch content in its trunk. Genetic improvement of sago palm is extremely slow when compared to other annual starch crops. Urgent attention is needed to improve the sago palm planting material and can be achieved through nonconventional methods. We have previously developed a tissue culture method for sago palm, which is used to provide the planting materials and to develop a genetic transformation procedure. Here, we report the genetic transformation of sago embryonic callus derived from suspension culture using Agrobacterium tumefaciens and gene gun systems. The transformed embryoids cells were selected against Basta (concentration 10 to 30 mg/L. Evidence of foreign genes integration and function of the bar and gus genes were verified via gene specific PCR amplification, gus staining, and dot blot analysis. This study showed that the embryogenic callus was the most suitable material for transformation as compared to the fine callus, embryoid stage, and initiated shoots. The gene gun transformation showed higher transformation efficiency than the ones transformed using Agrobacterium when targets were bombarded once or twice using 280 psi of helium pressure at 6 to 8 cm distance.

  9. Genetic Transformation of Metroxylon sagu (Rottb.) Cultures via Agrobacterium-Mediated and Particle Bombardment

    Science.gov (United States)

    Ibrahim, Evra Raunie

    2014-01-01

    Sago palm (Metroxylon sagu) is a perennial plant native to Southeast Asia and exploited mainly for the starch content in its trunk. Genetic improvement of sago palm is extremely slow when compared to other annual starch crops. Urgent attention is needed to improve the sago palm planting material and can be achieved through nonconventional methods. We have previously developed a tissue culture method for sago palm, which is used to provide the planting materials and to develop a genetic transformation procedure. Here, we report the genetic transformation of sago embryonic callus derived from suspension culture using Agrobacterium tumefaciens and gene gun systems. The transformed embryoids cells were selected against Basta (concentration 10 to 30 mg/L). Evidence of foreign genes integration and function of the bar and gus genes were verified via gene specific PCR amplification, gus staining, and dot blot analysis. This study showed that the embryogenic callus was the most suitable material for transformation as compared to the fine callus, embryoid stage, and initiated shoots. The gene gun transformation showed higher transformation efficiency than the ones transformed using Agrobacterium when targets were bombarded once or twice using 280 psi of helium pressure at 6 to 8 cm distance. PMID:25295258

  10. Impact spherules as a record of an ancient heavy bombardment of Earth.

    Science.gov (United States)

    Johnson, B C; Melosh, H J

    2012-05-03

    Impact craters are the most obvious indication of asteroid impacts, but craters on Earth are quickly obscured or destroyed by surface weathering and tectonic processes. Earth’s impact history is inferred therefore either from estimates of the present-day impactor flux as determined by observations of near-Earth asteroids, or from the Moon’s incomplete impact chronology. Asteroids hitting Earth typically vaporize a mass of target rock comparable to the projectile’s mass. As this vapour expands in a large plume or fireball, it cools and condenses into molten droplets called spherules. For asteroids larger than about ten kilometres in diameter, these spherules are deposited in a global layer. Spherule layers preserved in the geologic record accordingly provide information about an impact even when the source crater cannot be found. Here we report estimates of the sizes and impact velocities of the asteroids that created global spherule layers. The impact chronology from these spherule layers reveals that the impactor flux was significantly higher 3.5 billion years ago than it is now. This conclusion is consistent with a gradual decline of the impactor flux after the Late Heavy Bombardment.

  11. Influence of the ion bombardment of O{sub 2} plasmas on low-k materials

    Energy Technology Data Exchange (ETDEWEB)

    Verdonck, Patrick, E-mail: verdonck@imec.be [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Samara, Vladimir [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Open University, Materials Engineering, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Goodyear, Alec [Open University, Materials Engineering, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Ferchichi, Abdelkarim; Van Besien, Els; Baklanov, Mikhail R. [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Braithwaite, Nicholas [Open University, Department of Physics and Astronomy, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2011-10-31

    In this study, special tests were devised in order to investigate the influence of ion bombardment on the damage induced in low-k dielectrics by oxygen plasmas. By placing a sample that suffered a lot of ion bombardment and one which suffered little ion bombardment simultaneously in the same plasma, it was possible to verify that ion bombardment in fact helped to protect the low-k film against oxygen plasma induced damage. Exhaustive analyses (ellipsometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, porosimetry, capacitance-voltage (C-V) measurements, water contact angle analysis) show that ion bombardment induced the formation of a denser top layer in the film, which then hampered further penetration of active oxygen species deeper into the bulk. This was further confirmed by other tests combining capacitively and inductively coupled plasmas. Therefore, it was possible to conclude that, at least for these plasmas, ion bombardment may help to reduce plasma induced damage to low-k materials.

  12. Back bombardment for dispenser and lanthanum hexaboride cathodes

    Directory of Open Access Journals (Sweden)

    Mahmoud Bakr

    2011-06-01

    Full Text Available The back bombardment (BB effect limits wide usage of thermionic rf guns. The BB effect induces not only ramping-up of a cathode’s temperature and beam current, but also degradation of cavity voltage and beam energy during a macropulse. This paper presents a comparison of the BB effect for the case of dispenser tungsten-base (DC and lanthanum hexaboride (LaB_{6} thermionic rf gun cathodes. For each, particle simulation codes are used to simulate the BB effect and electron beam dynamics in a thermionic rf gun cathode. A semiempirical equation is also used to investigate the stopping range and deposited heat power of BB electrons in the cathode material. A numerical simulation method is used to calculate the change of the cathode temperature and current density during a single macropulse. This is done by solving two differential equations for the rf gun cavity equivalent circuit and one-dimensional thermal diffusion equation. High electron emission and small beam size are required for generation of a high-brightness electron beam, and so in this work the emission properties of the cathode are taken into account. Simulations of the BB effect show that, for a pulse of 6  μs duration, the DC cathode experiences a large change in the temperature compared with LaB_{6}, and a change in current density 6 times higher. Validation of the simulation results is performed using experimental data for beam current beyond the gun exit. The experimental data is well reproduced using the simulation method.

  13. Surface Morphologies of Ti and Ti-Al-V Bombarded by 1.0-MeV Au+ Ions

    Science.gov (United States)

    Garcia, M. A.; Rickards, J.; Cuerno, R.; Trejo-Luna, R.; Cañetas-Ortega, J.; de la Vega, L. R.; Rodríguez-Fernández, L.

    2017-12-01

    Ion implantation is known to enhance the mechanical properties of biomaterials such as, e.g., the wear resistance of orthopedic joints. Increasing the surface area of implants may likewise improve their integration with, e.g., bone tissue, which requires surface features with sizes in the micron range. Ion implantation of biocompatible metals has recently been demonstrated to induce surface ripples with wavelengths of a few microns. However, the physical mechanisms controlling the formation and characteristics of these patterns are yet to be understood. We bombard Ti and Ti-6Al-4V surfaces with 1.0-MeV Au+ ions. Analysis by scanning electron and atomic force microscopies shows the formation of surface ripples with typical dimensions in the micron range, with potential indeed for biomedical applications. Under the present specific experimental conditions, the ripple properties are seen to strongly depend on the fluence of the implanted ions while being weakly dependent on the target material. Moreover, by examining experiments performed for incidence angle values θ =8 ° , 23°, 49°, and 67°, we confirm the existence of a threshold incidence angle for (ripple) pattern formation. Surface indentation is also used to study surface features under additional values of θ , agreeing with our single-angle experiments. All properties of the surface structuring process are very similar to those found in the production of surface nanopatterns under low-energy ion bombardment of semiconductor targets, in which the stopping power is dominated by nuclear contributions, as in our experiments. We consider a continuum model that combines the effects of various physical processes as originally developed in that context, with parameters that we estimate under a binary-collision approximation. Notably, reasonable agreement with our experimental observations is achieved, even under our high-energy conditions. Accordingly, in our system, ripple formation is determined by mass

  14. Mechanisms of ion-bombardment-induced DNA transfer into bacterial E. coli cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, L.D., E-mail: yuld@thep-center.org [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sangwijit, K. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Phanchaisri, B. [Institute of Science and Technology Research, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Singkarat, S. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Anuntalabhochai, S. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2014-05-01

    Highlights: • Ion bombardment could induce DNA transfer into E. coli cells. • The DNA transfer induction depended on ion energy and fluence. • The mechanism was associated with the bacterial cell envelope structure. • A mechanism phase diagram was proposed to summarize the mechanism. - Abstract: As a useful ion beam biotechnology, ion-bombardment-induced DNA transfer into bacterial Escherichia coli (E. coli) cells has been successfully operated using argon ions. In the process ion bombardment of the bacterial cells modifies the cell envelope materials to favor the exogenous DNA molecules to pass through the envelope to enter the cell. The occurrence of the DNA transfer induction was found ion energy and fluence dependent in a complex manner. At ion energy of a few keV and a few tens of keV to moderate fluences the DNA transfer could be induced by ion bombardment of the bacterial cells, while at the same ion energy but to high fluences DNA transfer could not be induced. On the other hand, when the ion energy was medium, about 10–20 keV, the DNA transfer could not be induced by ion bombardment of the cells. The complexity of the experimental results indicated a complex mechanism which should be related to the complex structure of the bacterial E. coli cell envelope. A phase diagram was proposed to interpret different mechanisms involved as functions of the ion energy and fluence.

  15. ANALYTICAL MODELING OF ELECTRON BACK-BOMBARDMENT INDUCED CURRENT INCREASE IN UN-GATED THERMIONIC CATHODE RF GUNS

    Energy Technology Data Exchange (ETDEWEB)

    Edelen, J. P. [Fermilab; Sun, Y. [Argonne; Harris, J. R. [AFRL, NM; Lewellen, J. W. [Los Alamos Natl. Lab.

    2016-09-28

    In this paper we derive analytical expressions for the output current of an un-gated thermionic cathode RF gun in the presence of back-bombardment heating. We provide a brief overview of back-bombardment theory and discuss comparisons between the analytical back-bombardment predictions and simulation models. We then derive an expression for the output current as a function of the RF repetition rate and discuss relationships between back-bombardment, fieldenhancement, and output current. We discuss in detail the relevant approximations and then provide predictions about how the output current should vary as a function of repetition rate for some given system configurations.

  16. Inverse photoemission and LEED investigation of the ion-bombarded Ni(110) surface

    Science.gov (United States)

    Young, Benjamin; Warner, Jim; Heskett, David

    2012-02-01

    Ion bombardment of the clean Ni(110) surface is investigated by a combination of Inverse Photoemission Spectroscopy (IPES) with a Geiger-Muller detector and Low Energy Electron Diffraction (LEED) with a homebuilt video capture system. Disorder of the surface is induced by argon ion bombardment with various combinations of argon pressure and sputtering time. The intensity of the unoccupied surface state at ˜ 2eV above the Fermi level at the =Y point of the surface Brillouin zone decreases with increasing surface bombardment. Simultaneously, intensity profiles of diffraction spots in LEED exhibit broadening and a rising background level for increasing surface disorder. Multiple attempts at correlation between the results of the two techniques are presented.

  17. Nanometer-scale sharpening and surface roughening of ZnO nanorods by argon ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Shyamal, E-mail: shyamal@iitbbs.ac.in [School of Basic Sciences, Indian Institute of Technology, Bhubaneswar 751013 (India); Behera, Akshaya K. [School of Basic Sciences, Indian Institute of Technology, Bhubaneswar 751013 (India); Banerjee, Amarabha; Tribedi, Lokesh C. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Som, Tapobrata [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Ayyub, Pushan, E-mail: pushan@tifr.res.in [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

    2012-07-01

    We report the effects of exposing a hydrothermally grown, single crystalline ZnO nanorod array to a beam of 50 keV argon ions at room temperature. High resolution electron microscopy reveals that the ion bombardment results in a nanometer-scale roughening of the nanorod sidewalls, which were almost atomically flat in the pristine sample. Ion bombardment further causes the flat, Almost-Equal-To 100 nm diameter nanorod tips to get sharpened to ultrafine points less than 10 nm across. While tip sharpening is attributed to preferential sputtering, the formation of crystalline surface protuberances can be ascribed to surface instability due to curvature dependent sputtering and surface diffusion under argon-ion bombardment. Both the nanoscale roughening as well as the tip sharpening are expected to favorably impact a wide variety of applications, such as those involving catalysis, gas sensing, solar cells, field emission and gas discharge.

  18. Particularities of LaB sub 6 behaviour under bombardment with helium and argon energetic ions

    CERN Document Server

    Lesnyakov, G G; Klyimenko, V M; Pershyin, V F

    2002-01-01

    The investigation results on the bombardment of LaB sub 6 of 18 - 26% porosity with 20 keV helium and 0.5 keV argon ions are presented. the main contribution to the erosion is made by the material removal from the surface, which confirms the earlier conclusions about weakness of boundary grain, pores, and formation of cracks and round dislocation etch pits. It is shown that, during the bombardment as a dose is increased, a layer is formed on the LaB sub 6 surface with a subsequent change of the relative content of two elements. It is determined when and where one can expect the formation of LaB sub 4 under bombardment of the surface.

  19. Genetic transformation of banana and plantain (Musa spp.) via particle bombardment.

    Science.gov (United States)

    Sági, L; Panis, B; Remy, S; Schoofs, H; De Smet, K; Swennen, R; Cammue, B P

    1995-05-01

    We have developed a simple protocol to allow the production of transgenic banana plants. Foreign genes were delivered into embryogenic suspension cells using accelerated particles coated with DNA. Bombardment parameters were optimized for a modified particle gun resulting in high levels of transient expression of the beta-glucuronidase gene in both banana and plantain cells. Bombarded banana cells were selected with hygromycin and regenerated into plants. Molecular and histochemical characterization of transformants revealed the stable integration of the transferred genes into the banana genome.

  20. Energy Reflected from Solid Targets Bombarded keV Protons and Helium Ions

    DEFF Research Database (Denmark)

    Andersen, Hans Henrik; Lenskjaer, T.; Sidenius, G.

    1976-01-01

    The energy‐reflection coefficient γ has been measured for keV protons impinging on Cu, Au, and Pb and helium impinging on Si, Ag, Ta, and Pb. The results are obtained by entirely independent techniques in three different laboratories. They agree within the stated accuracies of 10%. For a given...

  1. Ion-Bombardment of Thin-Layers - the Effect on the Interface Roughness and Its X-Ray Reflectivity

    NARCIS (Netherlands)

    Puik, E. J.; van der Wiel, M. J.; Zeijlemaker, H.; Verhoeven, J.

    1992-01-01

    In this paper we report on experiments which indicate the necessity of the use of ion-beam bombardment for e-beam deposited multilayer x-ray coatings. Measurements are described in which ion bombardment (200-300 eV Ar+) is used to ion etch metal layers after initial deposition and during deposition

  2. Modified morphology of graphene sheets by Argon-atom bombardment: molecular dynamics simulations.

    Science.gov (United States)

    Wei, Xiao-Lin; Zhang, Kai-Wang; Wang, Ru-Zhi; Liu, Wen-Liang; Zhong, Jian-Xin

    2011-12-01

    By a molecular dynamics method, we simulated the process of Argon-atom bombardment on a graphene sheet with 2720 carbon atoms. The results show that, the damage of the bombardment on the graphene sheet depends not only on the incident energy but also on the particle flux density of Argon atoms. To compare and analyze the effect of the incident energy and the particle flux density in the Argon-atom bombardment, we defined the impact factor on graphene sheet by calculating the broken-hole area. The results indicate that, there is an exponential accumulated-damage for the impact of both the incident energy and the particle flux density and there is a critical incident energy ranging from 20-30 eV/atom in Argon-atom bombardment. Different configurations, such as sieve-like and circle-like graphene can be formed by controlling of different particle flux density as the incident energy is more than the critical value. Our results supply a feasible method on fabrication of porous graphene-based materials for gas-storages and molecular sieves, and it also helps to understand the damage mechanism of graphene-based electronic devices under high particle radiation.

  3. Effect of Ar bombardment on the electrical and optical properties of ...

    Indian Academy of Sciences (India)

    The influence of low-energy Ar ion beam irradiation on both electrical and optical properties of low-density polyethylene (LDPE) films is presented. The polymer films were bombarded with 320 keV Ar ions with fuences up to 1 × 10 15 cm − 2 . Electrical properties of LDPE films were measured and the effect of ion ...

  4. Transient expression of GUS in bombarded embryogenic longleaf, loblolly, and eastern white pine

    Science.gov (United States)

    Alex M. Diner; Allan Zipf; Rufina Ward; Yinghua Huang; George Brown

    1999-01-01

    Embryogenic tissue cultures derived from immature zygotic embryos of longleaf, loblolly, and eastern white pine were maintained in culture for up to 2 years, then bombarded with gold particles coated with a gene construct containing the GUS reporter gene fused to an adenine methyltransferase promoter from an algal virus. Physiological expression of GUS was observed in...

  5. Direct thermal effects of the Hadean bombardment did not limit early subsurface habitability

    Science.gov (United States)

    Grimm, R. E.; Marchi, S.

    2018-03-01

    Intense bombardment is considered characteristic of the Hadean and early Archean eons, yet some detrital zircons indicate that near-surface water was present and thus at least intervals of clement conditions may have existed. We investigate the habitability of the top few kilometers of the subsurface by updating a prior approach to thermal evolution of the crust due to impact heating, using a revised bombardment history, a more accurate thermal model, and treatment of melt sheets from large projectiles (>100 km diameter). We find that subsurface habitable volume grows nearly continuously throughout the Hadean and early Archean (4.5-3.5 Ga) because impact heat is dissipated rapidly compared to the total duration and waning strength of the bombardment. Global sterilization was only achieved using an order of magnitude more projectiles in 1/10 the time. Melt sheets from large projectiles can completely resurface the Earth several times prior to ∼4.2 Ga but at most once since then. Even in the Hadean, melt sheets have little effect on habitability because cooling times are short compared to resurfacing intervals, allowing subsurface biospheres to be locally re-established by groundwater infiltration between major impacts. Therefore the subsurface is always habitable somewhere, and production of global steam or silicate-vapor atmospheres are the only remaining avenues to early surface sterilization by bombardment.

  6. The influence of argon ion bombardment on the electrical and optical properties of clean silicon surfaces

    NARCIS (Netherlands)

    Martens, J.W.D.; van den Bogert, W.F.; van Silfhout, Arend

    1981-01-01

    The effect of low energy noble gas ion bombardment on the electrical and optical properties of Si(211) surfaces has been investigated by surface conductivity and field effect measurements, ellipsometry and AES. With this combination of techniques, information is obtained concerning the electrical

  7. High depth resolution SIMS analysis using metal cluster complex ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, M; Kinno, T; Koike, M; Tanaka, H; Takeno, S [Corporate Research and Development Center, Toshiba Corporation, 8 Shinsugita-cho, Isogo-ku, Yokohama 235-8522 (Japan); Fujiwara, Y; Kondou, K; Teranishi, Y; Nonaka, H; Fujimoto, T; Kurokawa, A; Ichimura, S [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba-shi, Ibaraki-ken 305-8568 (Japan)], E-mail: mitsuhiro.tomita@toshiba.co.jp

    2008-03-15

    SIMS depth profiles were measured using metal cluster complex ions of Ir{sub 4}(CO){sub 7}{sup +} as a primary ion beam in order to obtain high depth resolution. Depth resolution was evaluated as a function of primary ion species, energy and incident angle using a multiple boron delta-doped silicon sample. The depth resolution obtained using cluster ion bombardment was considerably better than that obtained by oxygen ion bombardment under the same bombardment condition due to reduction of atomic mixing in the depth. The best depth resolution was 0.9 nm under the bombardment condition of 5 keV, 45 deg. with oxygen flooding, which approaches the value measured with state of the art SIMS analyses. However, depth resolution was not improved by decreasing the cluster ion energy (less than 5 keV), even though the roughness of the sputtered surface was suppressed. The limit of depth resolution improvement may be caused by a carbon cover-layer that prevents the formation of surface oxide that buffers atomic mixing. To overcome this issue, it will be necessary to eliminate carbon from the cluster ion.

  8. Bombardment of gas molecules on single graphene layer at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Murugesan, Ramki [School of Mechanical and Aerospace Engineering, Gyeongsang National University, Jinju, Gyeongnam 660-701 (Korea, Republic of); Park, Jae Hyun [Department of Aerospace and System Engineering and Research Center for Aircraft Parts Technology, Gyeongsang National University, Jinju, Gyeongnam 660-701 (Korea, Republic of); Ha, Dong Sung [Future Propulsion Center, Agency for Defense Development, Daejeon 305-600 (Korea, Republic of)

    2014-12-09

    Graphite is widely used as a material for rocket-nozzle inserts due to its excellent thermo-physical properties as well as low density. During the operation of rockets, the surface of the graphite nozzle is subjected to very high heat fluxes and the undesirable erosion of the surface occurs due to the bombardment of gas molecules with high kinetic energy, which causes a significant reduction of nozzle performance. However, the understanding and quantification of such bombardment is not satisfactory due to its complexity: The bond breaking-forming happens simultaneously for the carbon atoms of graphene, some gas molecules penetrate through the surface, some of them are reflected from the surface, etc. In the present study, we perform extensive molecular dynamics (MD) simulations to examine the bombardment phenomena in high temperature environment (several thousand Kelvin). Advanced from the previous studies that have focused on the bombardment by light molecules (e.g., H{sub 2}), we will concentrate on the impact by realistic molecules (e.g., CO{sub 2} and H{sub 2}O). LAMMPS is employed for the MD simulations with NVE ensemble and AIREBO potential for graphene. The molecular understanding of the interaction between graphene and highly energetic gas molecules will enable us to design an efficient thermo-mechanical protection system.

  9. Particle bombardment and the genetic enhancement of crops: myths and realities

    NARCIS (Netherlands)

    Altpeter, F.; Baisakh, N.; Beachy, R.; Bock, R.; Capell, T.; Christou, P.; Daniell, H.; Datta, K.; Datta, S.; Dix, P.J.; Fauquet, C.; Huang, N.; Kohli, A.; Mooibroek, H.; Nicholson, L.; Nguyen, T.T.; Nugent, G.; Raemakers, C.J.J.M.; Romano, A.; Somers, D.A.; Stoger, E.; Taylor, N.; Visser, R.G.F.

    2005-01-01

    DNA transfer by particle bombardment makes use of physical processes to achieve the transformation of crop plants. There is no dependence on bacteria, so the limitations inherent in organisms such as Agrobacterium tumefaciens do not apply. The absence of biological constraints, at least until DNA

  10. Angular and energy dependence of ion bombardment of Mo/Si multilayers

    DEFF Research Database (Denmark)

    Voorma, H.J.; Louis, E.; Bijkerk, F.

    1997-01-01

    The process of ion bombardment is investigated for the fabrication of Mo/Si multilayer x-ray mirrors using e-beam evaporation. The ion treatment is applied immediately after deposition of each of the Si layers to smoothen the layers by removing an additional thickness of the Si layer. In this study...

  11. Influence of ion-beam bombardment on the optical properties of LDPE polymer blends

    Science.gov (United States)

    Rizk, R. A. M.; Abdul-Kader, A. M.; Ali, M.; Ali, Z. I.

    2008-10-01

    Ion beams have been found to be widely applicable in improving the structure and physical properties of polymers. In this paper, the effect of ion bombardment on the optical properties of low density polyethylene (LDPE)/styrene butadiene rubber (SBR) blend (LDPE/SBR) was studied. Polymer samples were bombarded with 130 keV He and 320 keV Ar ions to fluencies ranging from 1 × 1013 to 2 × 1016 ions cm-2. The pristine and ion beam bombarded samples were investigated using ultraviolet-visible (UV-Vis) spectrophotometry. The optical band gap (Eg) was decreased from ~2.3 to ~1.22 eV for the pristine sample and those samples bombarded with He and Ar ions at the highest fluence. The change in the optical gap indicates the presence of a gradual phase transition for the polymer blends. With increasing ion fluence, a decrease in both the energy gap and the activation energy was observed. The number of carbon atoms (N) in a formed cluster is found to be directly proportional to ion fluence and is determined according to the modified Tauc equation.

  12. Linear and nonlinear effects at low energy ion bombardment of solid xenon

    DEFF Research Database (Denmark)

    Dutkiewicz, L.; Pedrys, R.; Schou, Jørgen

    1996-01-01

    Elastic sputtering of crystalline xenon by 20-750 eV Xe ions has been studied with molecular dynamics. The nonlinear effects are dominant at 250 eV ion bombardment. They result in a partly amorphization of the impact volume as well as in a considerable reduction of the surface binding energy...

  13. Particle bombardment and subcellular protein localization analysis in the aquatic plant Egeria densa

    Directory of Open Access Journals (Sweden)

    Yasuhide Osaki

    2017-09-01

    Full Text Available Particle bombardment is a powerful and relatively easy method for transient expression of genes of interest in plant cells, especially those that are recalcitrant to other transformation methods. This method has facilitated numerous analyses of subcellular localization of fluorescent fusion protein constructs. Particle bombardment delivers genes to the first layer of plant tissue. In leaves of higher plants, epidermal cells are the first cell layer. Many studies have used the epidermal cell layer of onion bulb (Allium cepa as the experimental tissue, because these cells are relatively large. However, onion epidermal cells lack developed plastids (i.e., chloroplasts, thereby precluding subcellular localization analysis of chloroplastic proteins. In this study, we developed a protocol for particle bombardment of the aquatic plant Egeria densa, and showed that it is a useful system for subcellular localization analysis of higher plant proteins. E. densa leaflets contain only two cell layers, and cells in the adaxial layer are sufficiently large for observation. The cells in both layers contain well-developed chloroplasts. We fused fluorescent proteins to conventional plant localization signals for the nucleus, cytosol, mitochondria, peroxisome, and chloroplast, and used particle bombardment to transiently express these fusion constructs in E. densa leaves. The plant subcellular localization signals functioned normally and displayed the expected distributions in transiently transformed E. densa cells, and even chloroplastic structures could be clearly visualized.

  14. Sputtering yields of Ru, Mo, and Si under low energy Ar+ bombardment

    NARCIS (Netherlands)

    Wu, S. M.; van de Kruijs, R.; Zoethout, E.; F. Bijkerk,

    2009-01-01

    Ion sputtering yields for Ru, Mo, and Si under Ar+ ion bombardment in the near-threshold energy range have been studied using an in situ weight-loss method with a Kaufman ion source, Faraday cup, and quartz crystal microbalance. The results are compared to theoretical models. The accuracy of the in

  15. Sputtering yields of Ru, Mo and Si under low energy Ar+ bombardment

    NARCIS (Netherlands)

    Wu, Shiou-Min; van de Kruijs, Robbert Wilhelmus Elisabeth; Zoethout, E.; Zoethout, E.; Bijkerk, Frederik

    2009-01-01

    Ion sputtering yields for Ru, Mo, and Si under Ar+ ion bombardment in the near-threshold energy range have been studied using an in situ weight-loss method with a Kaufman ion source, Faraday cup, and quartz crystal microbalance. The results are compared to theoretical models. The accuracy of the in

  16. Thermal stability of magnetic nanostructures in ion-bombardment-modified exchange-bias systems

    Science.gov (United States)

    Höink, V.; Sacher, M. D.; Schmalhorst, J.; Reiss, G.; Engel, D.; Weis, T.; Ehresmann, A.

    2006-06-01

    In magnetic bilayer systems consisting of a ferromagnet and an antiferromagnet the strength and direction of the exchange bias coupling can be set by ion bombardment in an external magnetic field. Magnetic nanostructures with a laterally varying exchange bias direction can be produced by local ion bombardment (ion bombardment induced magnetic patterning). We have investigated the thermal stability of these magnetic nanostructures by in situ x-ray photoemission electron microscopy while heating the samples above their blocking temperature. The investigations have been done at a 10.4μm×10.4μm large checkered pattern with a minimum size of the magnetic patterns of 800nm×800nm on a field cooled MnIr/CoFe stack and a pattern with 1.6μm wide lines with a periodicity of 5μm on an as-prepared MnIr/Co stack. The temperature dependence of the magnetization pattern can be explained by the temperature dependence of the exchange bias interaction, the exchange interaction energy, and the stray field energy. No substantial change of the thermal stability of magnetic patterns in remanence by the ion bombardment was found.

  17. SMART-1 highlights and relevant studies on early bombardment and geological processes on rocky planets

    Energy Technology Data Exchange (ETDEWEB)

    Foing, B H; Koschny, D; Frew, D; Almeida, M; Zender, J; Heather, D; Peters, S [ESA Research and Scientific Support Department, ESTEC/SCI-S, Postbus 299, 10 ESA Noordwijk (Netherlands); Racca, G D; Marini, A; Stagnaro, L [ESA Scientific Project Department, ESTEC/SCI-PD, Postbus 299, 10 ESA Noordwijk (Netherlands); Josset, J L [Space-X, Space Exploration Institute, Rue Jacquet Droz 1, CH 2007 Neuchatel (Switzerland); Beauvivre, S [Micro-Cameras SA, Neuchatel, Puits-godet 10a, CH-2000 Neuchatel (Switzerland); Grande, M [University of Wales, Aberystwyth, SY23 3BZ (United Kingdom); Kellett, B [Rutherford Appleton Labs, Harwell Science and Innovation Campus, Didcot, OX11 0QX (United Kingdom); Huovelin, J [Finnish Meteorology Institute, Helsinki International Airport, Helsinki (Finland); Nathues, A; Mall, U [Max-Planck-Institute for Solar System Research, Lindau (Germany); Ehrenfreund, P [Leiden University, PO Box 9500, 2300 RA Leiden (Netherlands); McCannon, P [ESA Directorate of Technology, ESTEC/TEC, 10 ESA Noordwjik (Netherlands)], E-mail: Bernard.Foing@esa.int

    2008-08-15

    We present results from SMART-1 science and technology payload, in the context of the Nobel symposium on 'Physics of Planetary Systems'. SMART-1 is Europe' first lunar mission (Foing et al 2000 LPSC XXXI Abstract 1677 (CDROM); Foing et al 2001 Earth, Moon Planets 85-86 523-31; Marini et al 2002 Adv. Space Res. 30 1895-900; Racca et al 2001 Earth Moon Planets 85-86 379-95, Racca et al 2002 Planet Space Sci. 50 1323-37) demonstrating technologies for future science and exploration missions, and providing advances in our understanding of lunar origin and evolution, and general planetary questions. The mission also contributes a step in developing an international program of lunar exploration. The spacecraft, launched on 27 September 2003 as an Ariane 5 Auxiliary passenger to geostationary transfer orbit (GTO), performed a 14-month long cruise using a tiny thrust of electric propulsion alone, reached lunar capture in November 2004, and lunar science orbit in March 2005. SMART-1 carried 7 hardware experiments (Foing et al 2003 Adv. Space Res. 31 2323, Foing et al 2005 LPI/LPSC XXXVI 2404 (CDROM)) performing 10 investigations, including 3 remote-sensing instruments, used during the cruise, the mission' nominal six-months and one-year extension in lunar science orbit. Three remote sensing instruments, D-CIXS, SIR and AMIE, have returned data that are relevant to a broad range of lunar studies. The mission provided regional and global x-ray measurements of the Moon, global high-spectral resolution NIR spectrometry, high spatial resolution colour imaging of selected regions. The South Pole-Aitken Basin (SPA) and other impact basins have been prime targets for studies using the SMART-1 suite of instruments. Combined, these should aid a large number of science studies, from bulk crustal composition and theories of lunar origin/evolution, the global and local crustal composition, to the search for cold traps at the lunar poles and the mapping of potential

  18. Secondary ion emission from A sup I sup I sup I B sup V compound semiconductors under MeV-energy heavy ion bombardment

    CERN Document Server

    Ninomiya, S; Nagai, M; Nakata, Y; Imai, M; Imanishi, N

    2003-01-01

    Mass and yields of secondary ions emitted from GaP, GaAs, GaSb and InSb targets bombarded by MeV-energy heavy ion have been investigated. Obtained feature of the secondary ion emission depends characteristically on the target species. Molecular and small cluster ions were emitted from the GaP and GaAs targets. On the other hand, pretty large cluster ions were emitted from the GaSb and InSb targets. Yields of clusters from the GaSb target increase with increasing the incident energy and decrease exponentially with the cluster size, while yields from the InSb target keep constant or decrease gently with increasing the incident energy and show the power law dependence on the cluster size. These results show that cluster ions from the GaSb target are formed through a coagulation of small molecules emitted from the target in the selvage region near the surface, and those from the InSb target are emitted directly from the surface as cluster.

  19. Erosion of Be and deposition of C and O due to bombardment with C{sup +} and CO{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Eckstein, W.; Goldstrass, P.; Linsmeier, Ch. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1998-01-01

    The bombardment of Be with 3 and 5 keV C{sup +} and CO{sup +} at normal incidence is investigated experimentally and by computer simulation with the program TRIDYN. The deposited amount of C and O is determined experimentally and found in good agreement with calculated data for C bombardment. Chemical erosion dominates at higher fluences for CO{sup +} bombardment. Calculations are then used to determine the sputter yield of Be at steady state conditions as a function of the plasma edge electron temperature for two C impurity concentrations in the incident D flux, typical for fusion plasmas. The fluence to reach steady state conditions is also investigated. (author)

  20. Successful expression in pollen of various plant species of in vitro synthesized mRNA introduced by particle bombardment.

    Science.gov (United States)

    Tanaka, T; Nishihara, M; Seki, M; Sakamoto, A; Tanaka, K; Irifune, K; Morikawa, H

    1995-05-01

    Gold particles coated with beta-glucuronidase (GUS) mRNA with a 5' cap structure that had been synthesized in vitro were introduced, by use of a pneumatic particle gun, into pollen grains of lily (Lilium longiflorum), freesia (Freesia refracta) and tulip (Tulipa gesneriana). A fluorometric assay for the GUS activity indicated that in vitro synthesized GUS mRNA introduced into these pollen cells by particle bombardment was successfully expressed. GUS activity in extracts of the bombarded lily pollen became detectable fluorometrically within 30 min after bombardment, peaked at 6 h, then gradually decreased. This activity changed as a function of the developmental stage of the pollen cell of lily.

  1. Initialization of unidirectional anisotropy in a ferromagnet-antiferromagnet bilayer by keV-He ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Engel, D. [Fachbereich Physik, Technische Universitaet Kaiserslautern, Erwin-Schroedinger-Str. D-67663 Kaiserslautern (Germany)]. E-mail: wengel@rhrk.uni-kl.de; Ehresmann, A. [Fachbereich Physik, Technische Universitaet Kaiserslautern, Erwin-Schroedinger-Str. D-67663 Kaiserslautern (Germany); Schmalhorst, J. [Fakultaet fuer Physik, Universitaet Bielefeld, D-33501 Bielefeld (Germany); Sacher, M. [Fakultaet fuer Physik, Universitaet Bielefeld, D-33501 Bielefeld (Germany); Hoeink, V. [Fakultaet fuer Physik, Universitaet Bielefeld, D-33501 Bielefeld (Germany); Reiss, G. [Fakultaet fuer Physik, Universitaet Bielefeld, D-33501 Bielefeld (Germany)

    2005-06-15

    A polycrystalline Cu/Ni{sub 80}Fe{sub 20}/Mn{sub 83}Ir{sub 17}/Co/AlO{sub x} ferromagnet-antiferromagnet layer system grown without applying an external magnetic field shows no unidirectional anisotropy in the as-prepared state. After 10keV-He ion bombardment in an external in-plane magnetic field, a clear unidirectional anisotropy collinear to the magnetic field direction during bombardment is observed, indicating that ion bombardment can be used for this system to initialize the unidirectional exchange anisotropy. The magnetization reversal processes for various ion doses are discussed, based on longitudinal magnetooptical Kerr-effect measurements.

  2. Quantitative multielement analysis using high energy particle bombardment

    Science.gov (United States)

    Clark, P. J.; Neal, G. F.; Allen, R. O.

    1975-01-01

    Charged particles ranging in energy from 0.8 to 4.0 MeV are used to induce resonant nuclear reactions, Coulomb excitation (gamma-rays), and X-ray emission in both thick and thin targets. Quantitative analysis is possible for elements from Li to Pb in complex environmental samples, although the matrix can severely reduce the sensitivity. It is necessary to use a comparator technique for the gamma-rays while for X-rays an internal standard can be used. A USGS standard rock is analyzed for a total of 28 elements. Water samples can be analyzed either by nebulizing the sample doped with Cs or Y a thin Formvar film or by extracting the sample onto ion exchange resin which is pressed into a pellet.

  3. Determine Neutron Yield From Beryllium Compounds Bombarding With Alpha Particles

    Directory of Open Access Journals (Sweden)

    Osamah Nawfal Oudah

    2015-04-01

    Full Text Available Abstract The chemical combination of Beryllium used in the amp945n reaction as a target materials. wherefore Beryllium has generally been the material of select when manufacturing a neutron source. Beryllium compounds has a significant impact on the scheme and manufacture of the 238Cm-9Be neutron source. In present work the Beryllium chemical combinations were considered as a producer of neutrons with different percentage of mass and the neutron yields were likewise determined using the outcomes of the ASTAR calculations per unit incident charge. The neutron yields of Beryllium Oxide Beryllium Carbide Beryllium Hydride Beryllium Hydroxide and Beryllium Nitride were calculated as 3.1006e-005 3.0365e-005 2.2866e-005 2.0464e-005 and 3.0386e-005respectively. The results show that the Beryllium Oxide is a suitable material to use in the 238Cm-9Be neutron source.

  4. Influence of the inert and active ion bombardment on structure of the transition metal thin films

    CERN Document Server

    Blazhevich, S; Martynov, I; Neklyudov, I

    2002-01-01

    The results of the experimental research of the inert (He, Ne, Ar, Kr, Xe) and active (O, N) ion impact on the transition metal structure are presented. Thin high-purity (99.999 at.%) films of nickel, chrome and iron were used in the experiment. The bombardment was realized under room temperature at high vacuum (P<1x10 sup - sup 7 Pa) by a separated ion beam of 10-10 sup 3 keV. As a main result of the experiment, the full absence of crystal matrix changes was ascertained for all the transition metals irradiated by inert gas ions. The chemical nature of the crystal structure changes observed in transition metals being under active ion bombardment was found out too.

  5. Rehabilitation and construction of bridges damaged in NATo-bombardment of SR Yugoslavia in 1999

    Directory of Open Access Journals (Sweden)

    Vlajić Ljubomir M.

    2014-01-01

    Full Text Available Structural engineers from Serbia and nearby countries have long tradition in area of design and construction of bridges. Beside ancient stone bridges from the past centuries, in the second half of the XX century, significant professional and science level in all areas of bridge construction have been achieved. Many of projects from that time have become famous all around the globe and were object of pride for everyone included in realization of those. Regretfully, during seventy eight days, in the period from 24th March till the 10th July 1999, in NATO bombardment of SR Yugoslavia, 44 road, 17 railway and one road railway bridge have been totally or partially destroyed. In this article have been described structural damages, rehabilitation and construction, with short description of characteristic cases of bridges, which have been object of bombardment.

  6. Adsorption Site of Gas Molecules on Defective Armchair Graphene Nanoribbon Formed Through Ion Bombardment

    Science.gov (United States)

    Auzar, Zuriana; Johari, Zaharah; Sakina, S. H.; Alias, N. Ezaila

    2018-02-01

    High sensitivity and selectivity is desired in sensing devices. The aim of this study is to investigate the use of the ion bombardment process in creating a defect on graphene nanoribbons (GNR), which significantly affects sensing properties, in particular adsorption energy, charge transfer and sensitivity. A process has been developed to form the defect on the GNR surface using molecular dynamic (MD) with a reactive force field with nitrogen ion. The sensing properties were calculated using the extended Huckel theory when oxygen (O2) and ammonia (NH3) molecules are exposed to different areas on the defective site. Through simulation, it was found that the ion bombardment process formed various types of defects on the GNR surface. Most notably, molecules adsorbed on the ripple area considerably improve the sensitivity by more than 50%. This indicates that the defect on the armchair graphene nanoribbon (AGNR) surface can be a method to enhance graphene-based sensing performance.

  7. Genetic transformation of Platymonas ( Tetraselmis) subcordiformis (Prasinophyceae, Chlorophyta) using particle bombardment and glass-bead agitation

    Science.gov (United States)

    Cui, Yulin; Jiang, Peng; Wang, Jinfeng; Li, Fuchao; Chen, Yingjie; Zheng, Guoting; Qin, Song

    2012-05-01

    Platymonas ( Tetraselmis) subcordiformis is a unicellular marine green alga. It was found to be very sensitive to the herbicide Basta through a sensitivity test indicating it could be employed as a selective agent. The bar gene is a practicable and selectable marker gene. The vector containing the expression cassette of the bar gene was transferred to P. subcordiformis by both particle bombardment and glass-bead agitation and transformants were then selected using Basta. Finally, Southern blotting analysis indicated that the bar gene had been successfully integrated into the nuclear genome of P. subcordiformis using both of the transgenic techniques, with the transformation efficiency of the glass-bead method being slightly higher than that of particle bombardment. This is the first report on stable transformation of P. subcordiformis, and will improve fundamental research and enlarge application of this alga.

  8. Films deposited from reactive sputtering of aluminum acetylacetonate under low energy ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Battaglin, Felipe Augusto Darriba; Prado, Eduardo Silva; Cruz, Nilson Cristino da; Rangel, Elidiane Cipriano, E-mail: elidiane@sorocaba.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sorocaba, SP (Brazil). Lab. de Plasmas Tecnologicos; Caseli, Luciano [Universidade Federal de Sao Paulo (UNIFESP), Diadema, SP (Brazil). Instituto de Ciencias Ambientais, Quimicas e Farmaceuticas; Silva, Tiago Fiorini da; Tabacniks, Manfredo Harri [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica

    2017-07-15

    Films were deposited from aluminum acetylacetonate (Al(acac)3 ) using a methodology involving reactive sputtering and low energy ion bombardment. The plasma was generated by the application of radiofrequency power to the powder containing electrode and simultaneously, negative pulses were supplied to the electrode where the substrates were attached. It was investigated the effect of the duty cycle of the pulses (Δ) on the properties of the coatings. Association of ion bombardment to the deposition process increased film thickness, structure reticulation and organic content. Ions from the deposition environment were implanted at the film-air interface or underneath it. Morphology and topography were altered depending on Δ. Considering the enhancement of Δ, it affected the flux of ions reaching the depositing interface and then the deposition rate, H content, crosslinking degree and surface microstructure. Alumina groups were detected in the infrared spectra, whereas the precipitation of amorphous alumina was confirmed by X-ray diffraction. (author)

  9. Highly ordered nanoscale patterns produced by masked ion bombardment of a moving solid surface

    Science.gov (United States)

    Gelfand, Martin P.; Bradley, R. Mark

    2012-09-01

    We introduce a fabrication method in which a mask with a long, narrow slit is placed between the source of an ion beam and the surface of a solid moving with constant speed. Numerical simulations reveal the method can generate surface ripples and arrays of nanoholes that are virtually defect free. In contrast, the patterns produced by ion bombardment with a broad, unmasked beam are typically rife with defects.

  10. A travelling wave model of ripple formation on ion bombarded surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Numazawa, Satoshi, E-mail: s.numazawa@hzdr.de; Smith, Roger, E-mail: R.Smith@lboro.ac.uk

    2013-05-15

    We present a mathematical model describing surface modification resulting from atomic motion after ion bombardment. The model considers only the defect production and recovery process induced by the local atom rearrangement and is essentially independent of surface topography changes formed by both sputtering and surface diffusion. A stable analytic, travelling wave solution is presented for a specific incident angle, which agrees with experimental observation excellently.

  11. A review of electron bombardment thruster systems/spacecraft field and particle interfaces

    Science.gov (United States)

    Byers, D. C.

    1978-01-01

    This paper collates and summarizes information on the field and particle interfaces of electron bombardment ion thruster systems. Major areas discussed are the nonpropellant particles, neutral propellant, ion beam, low energy plasma, and fields. Spacecraft functions and subsystems reviewed are solar arrays, thermal control systems, optical sensors, communications, science, structures and materials, and potential control. An appendix is included to facilitate identification of specific interaction areas.

  12. Non-thermodynamic approach to including bombardment-induced post-cascade redistribution of point defects in dynamic Monte Carlo code

    CERN Document Server

    Ignatova, V A; Katardjiev, I V

    2003-01-01

    The redistribution of the elements as a result of atomic relocations produced by the ions and the recoils due to the ballistic and transport processes is investigated by making use of a dynamic Monte Carlo code. Phenomena, such as radiation-enhanced diffusion (RED) and bombardment-induced segregation (BIS) triggered by the ion bombardment may also contribute to the migration of atoms within the target. In order to include both RED and BIS in the code, we suggest an approach which is considered as an extension of the binary collision approximation, i.e. it takes place 'simultaneously' with the cascade and acts as a correction to the particle redistribution for low energies. Both RED and BIS models are based on the common approach to treat the transport processes as a result of a random migration of point defects (vacancies and interstitials) according to a probability given by a pre-defined Gaussian. The models are tested and the influence of the diffusion and segregation is illustrated in the cases of 12 keV ...

  13. Segregation under low-energy oxygen bombardment in the near-surface region

    Science.gov (United States)

    Tada, Y.; Suzuki, K.; Kataoka, Y.

    2008-12-01

    We found that a transient region of SIMS profiles was suppressed to less than the native oxide in silicon, with O 2+ bombardment energy of less than 0.2 keV under an incident angle of 0° with respect to the surface normal without oxygen flooding. However, gallium segregated significantly due to oxidation caused by O 2+ bombardment in this condition. We also found that the segregation decreased as the incident angle increased, and that it disappeared at the angle of around 40°, which was verified by comparing SIMS profiles with the HR-RBS profile. These results suggested that the angle of around 40° was the critical angle to prevent segregation. The transient region was almost the same at angles of 0-40°. Therefore, we consider that the energy of 0.2 keV at the angle of around 40° under O 2+ bombardment without oxygen flooding is the optimum SIMS condition for depth profiling in the near-surface region. On the other hand, the profile shift of arsenic depending on the angle was quite different as compared with gallium, but the shift was a minimum at the same critical angle. We expect that more accurate profiles for other impurities can be obtained using this SIMS condition.

  14. On the history of the early meteoritic bombardment of the Moon: Was there a terminal lunar cataclysm?

    Science.gov (United States)

    Michael, Greg; Basilevsky, Alexander; Neukum, Gerhard

    2018-03-01

    the considered histograms and relative probability plots not only the 3.87 Ga peak (due to Imbrium basin), but also several secondary peaks caused by the formation of other basins distributed between 3.87 and 4.25 Ga. The lunar terminal cataclysm hypothesis is in disagreement with the distribution of K-Ar ages for the highland rocks of the lunar meteorites. The population of lunar meteorites representing localities randomly distributed over the lunar surface, and thus free from the mentioned sampling bias, shows no ∼3.9 Ga peak as it should, if the cataclysm did occur. We conclude that the statistics of sample ages contradict the terminal cataclysm scenario in the bombardment of the Moon. We also see evidence for the formation of several impact basins between 3.87 and 4.25 Ga which is likewise incompatible with the hypothesis of a short interval cataclysm. There remain other basins, including the largest South Pole - Aitken, the ages of which should be determined in future studies to further clarify the impact history. Sample-return missions targeted to date several key basins need to be planned, and the continued study of lunar meteorites may also bring new details to the general view of the impact bombardment of the Moon.

  15. Confirming the key role of Ar+ ion bombardment in the growth feature of nanostructured carbon materials by PECVD

    Science.gov (United States)

    Liu, Yulin; Lin, Jinghuang; Jia, Henan; Chen, Shulin; Qi, Junlei; Qu, Chaoqun; Cao, Jian; Feng, Jicai; Fei, Weidong

    2017-11-01

    In order to confirm the key role of Ar+ ion bombardment in the growth feature of nanostructured carbon materials (NCMs), here we report a novel strategy to create different Ar+ ion states in situ in plasma enhanced chemical vapor deposition (PECVD) by separating catalyst film from the substrate. Different bombardment environments on either side of the catalyst film were created simultaneously to achieve multi-layered structural NCMs. Results showed that Ar+ ion bombardment is crucial and complex for the growth of NCMs. Firstly, Ar+ ion bombardment has both positive and negative effects on carbon nanotubes (CNTs). On one hand, Ar+ ions can break up the graphic structure of CNTs and suppress thin CNT nucleation and growth. On the other hand, Ar+ ion bombardment can remove redundant carbon layers on the surface of large catalyst particles which is essential for thick CNTs. As a result, the diameter of the CNTs depends on the Ar+ ion state. As for vertically oriented few-layer graphene (VFG), Ar+ ions are essential and can even convert the CNTs into VFG. Therefore, by combining with the catalyst separation method, specific or multi-layered structural NCMs can be obtained by PECVD only by changing the intensity of Ar+ ion bombardment, and these special NCMs are promising in many fields.

  16. N(50) Crater Retention Ages for an Expanded Inventory of Lunar Basins: Evidence for an Early Heavy Bombardment and a Late Heavy Bombardment?

    Science.gov (United States)

    Frey, Herbert; Burgess, Emily

    2012-01-01

    LOLA topography and LOLA-derived crustal thickness data provide evidence for a population of impact basins on the Moon that is likely a factor 2 larger than the classical lists based on photogeology. Frey (2012) determined N(50) crater retention ages (CRAs) for 83 candidate basins > 300 km in diameter by counting LOLA-identified craters superimposed over the whole area of the basins. For some basins identified in topography or model crustal thickness it is not possible to unambiguously identify the crater rim as is traditionally done. Also, Quasi-Circular Depressions (QCDs) > 50 km in diameter are recognizable in the mare-filled centers of many basins. Even though these are not apparent in image data, they likely represent buried impact craters superimposed on the basin floor prior to mare infilling and so should be counted in determining the age of the basin. Including these as well as the entire area of the basins improves the statistics, though the error bars are still large when using only craters > 50 km in diameter. The distribution of N(50) CRAs had two distinct peaks which did not depend on whether the basins were named (based on photogeology) or recognized first in topography or crustal thickness data. It also did not depend on basin diameters (both larger and smaller basins made up both peaks) and both peaks persisted even when weaker candidates were excluded. Burgess (2012, unpublished data) redid the counts for 85 basins but improved on the earlier effort by adjusting the counting area where basins overlap. The two peak distribution of N(50) ages was confirmed, with a younger peak at N(50) 40-50 and an older peak at N(50) 80-90 (craters > 50 km diameter per million square km). We suggest this could represent two distinct populations of impactors on the Moon: one producing an Early Heavy Bombardment (EHB) that predates Nectaris and the second responsible for the more widely recognized Late Heavy Bombardment (LHB).

  17. Cosmic Bombardment IV: Averting catastrophe in the here-and-now

    Energy Technology Data Exchange (ETDEWEB)

    Wood, L.; Hyde, R.; Ishikawa, M.; Ledebuhr, A.

    1994-09-23

    At the present time, it is at least arguable that large-scale cosmic bombardment has been a major driver of the evolution of the terrestrialbiosphere. The fundamental motivation of the present paper is the (high) likelihood that the advent and rise of the human species hasn`t coincided with the cessation of soft and hard collisions in the Asteroid Belt or in the Oort Cloud, and that we will either stop the cosmic bombardment or it will eventually stop us. In the foregoing, briefly reviewed the prospects for active planetary defenses against cosmic bombardment in the very near-term, employing only technologies which exist now and could be brought-to-bear in a defensive system on a one-decade time-scale. We sketch various means and mechanisms from a physicist`s viewpoint by which such defensive systems might detect threat objects, launch interdiction machinery toward them and operate such machinery in their vicinity to alternately deflect, disperse or vaporize objects in the 0.1-10 km-diameter range, the ones whose size and population constitute the greatest threats to our biosphere. We conclude that active defenses of all types are readily feasible against 0.1 kmdiameter incoming cosmic bomblets and that even complete vaporization-class defenses are feasible against 1 km-diameter class objects of all compositions. When facing Great Extinctors of up to 10 km diameter, the feasible defensive methods depend upon the object`s size and composition. Dispersion defenses are feasible against all threat-classes, as are deflection approaches for bomblets up to {approximately} 10 km diameter; vaporization-level protection is, however, available only against dirty snowballs` of the {approximately} 1--2 km diameter class. Great Extinctors of sizes significantly greater than 10 km diameter challenge contemporary human technology ever more severely; fortunately, they appear to be rare on the several Aeon time-scales over which Sol will shift its spectral class.

  18. Investigation of energy thresholds of atomic and cluster sputtering of some elements under ion bombardment

    CERN Document Server

    Atabaev, B G; Lifanova, L F

    2002-01-01

    Threshold energies of sputtering of negative cluster ions from the Si(111) surface were measured at bombardment by Cs sup + , Rb sup + , and Na sup + ions with energy of 0.1-3.0 keV. These results are compared with the calculations of the similar thresholds by Bohdansky etc. formulas (3) for clusters Si sub n sup - and Cu sub n sup - with n=(1-5) and also for B, C, Al, Si, Fe, Cu atoms. Threshold energies of sputtering for the above elements were also estimated using the data from (5). Satisfactory agreement between the experimental and theoretical results was obtained. (author)

  19. Reducing Back-Bombardment Effect Using Thermionic Cathode in IAE RF Gun

    CERN Document Server

    Kii, Toshiteru; Masuda, Kai; Murakami, Shio; Ohgaki, Hideaki; Yamazaki, Tetsuo; Yoshikawa, Kiyoshi; Zen, Heishun

    2004-01-01

    We have numerically studied on improvement of electron beam macro-pulse properties from thermionic RF gun [1,2]. Beam properties, such as energy spectrum, macro-pulse duration and emittance were measured with a 2 mm diameter slim thermionic dispenser cathode. Effect of the transverse magnetic field to reduce back-streaming electrons to these properties was studied experimentally. Comparison with measured and numerical results will be discussed. Effect of a non-flat RF input to compensate a decreasing beam energy during macropulse due to a back-bombardment effect will be also presented.

  20. Chromium recoil implantation into SAE 1020 steel by nitrogen ion bombardment

    OpenAIRE

    Gomes, G. F.; Ueda, M.; Reuther, H.; Richter, E.; Beloto, A. F.

    2004-01-01

    SAE 1020 is a widely used plain carbon steel, as mortar reinforcement in buildings and small machine parts. But aside from good mechanical properties, its surface suffer from severe corrosion and high wear rate, due to modest hardness. Chromium (Cr) in excess of 12% in Fe alloys renders them resistant to several corrosive attacks. So we tried to introduce Cr in such amounts into the surface of that steel. Cr films were deposited by electron beam on SAE 1020 steel. Bombarding the Cr film eithe...

  1. Absorption of hydrogen in vanadium, enhanced by ion bombardment; Ionenbeschussunterstuetzte Absorption des Wasserstoffs in Vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Paulus, H.; Lammers, M. [Inst. fuer Technologie- und Wissenstransfer, Soest (Germany); Mueller, K.H. [Inst. fuer Technologie- und Wissenstransfer, Soest (Germany)]|[Paderborn Univ. (Gesamthochschule), Soest (Germany). Fachbereich 16 - Elektrische Energietechnik; Kiss, G.; Kemeny, Z. [Technical Univ. Budapest (Hungary)

    1998-12-31

    Prior to hydrogen implantation into vanadium, the vanadium specimen usually is exposed to an activation process and is then heated at 1 atm hydrogen to temperatures between 500 and 600 C, subsequently cooled down in several steps. Within this temperature range, hydrogen solubility increases with declining temperature. A decisive factor determining hydrogen absorption is the fact that at temperatures above 250 C, oxygen desorbs from the material surface and thus no longer inhibits hydrogen absorption. Therefore a different approach was chosen for the experiments reported: Hydrogen absorption under UHV conditions at room temperature. After the usual activation process, the vanadium surface was cleaned by 5 keV Ar{sup +} ion bombardment. Thus oxygen absorption at the specimen surface (and new reactions with oxygen from the remaining gas) could be avoided, or removed. By means of thermal desorption mass spectrometry (TDMS), hydrogen absorption as a function of argon ion dose was analysed. TDMS measurements performed for specimens treated by ion bombardment prior to H{sup 2} exposure showed two H{sup 2} desorption peaks, in contrast to the profiles measured with specimens not exposed to ion bombardment. It is assumed that the ion bombardment disturbs the crystal structure so that further sites for hydrogen absorption are produced. (orig./CB) [Deutsch] Bei der Beladung von Vandium mit Wasserstoff wird ueblicherweise die Probe nach einer Aktivierungsprozedur bei 1 atm Wasserstoff auf Temperaturen im Bereich von 500 bis 600 C hochgeheizt und danach schrittweise abgekuehlt. In diesem Temperaturbereich nimmt die Wasserstoffloeslichkeit mit abnehmender Temperatur zu. Entscheidend fuer die Beladung ist aber auch die Tatsache, dass bei Temperaturen groesser 250 C Sauerstoff von der Oberflaeche desorbiert und dadurch die Absorption von Wasserstoff nicht mehr blockieren kann. Im Rahmen der hier beschriebenen Untersuchungen sollte die Wasserstoffbeladung unter UHV-Bedingungen bei

  2. Surface layer evolution caused by the bombardment with ionized metal vapor

    Energy Technology Data Exchange (ETDEWEB)

    Döbeli, M., E-mail: doebeli@phys.ethz.ch [Ion Beam Physics, ETH Zurich, Schafmattstrasse 20, CH-8093 Zurich (Switzerland); Dommann, A.; Maeder, X.; Neels, A. [Centre Suisse d’Electronique et de Microtechnique CSEM SA, Rue Jaquet-Droz 1, CH-2002 Neuchâtel (Switzerland); Passerone, D. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Rudigier, H. [OC Oerlikon Balzers AG, Iramali 18, LI-9496 Balzers (Liechtenstein); Scopece, D. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Widrig, B.; Ramm, J. [OC Oerlikon Balzers AG, Iramali 18, LI-9496 Balzers (Liechtenstein)

    2014-08-01

    The evolution of the composition of tungsten carbide and silicon surfaces initiated by the bombardment with Zr and Cr ions has been investigated as a function of the substrate bias voltage. Surface composition profiles were measured by Rutherford backscattering and have been compared with the results obtained by the TRIDYN simulation program. It is found that the general dependence of film thickness on substrate bias is satisfactorily reproduced by this model. Deviations between experiment and simulation are attributed to possible partial oxidation of the surface or uncertainties in the charge state distribution of metal ions. The results confirm that TRIDYN facilitates the predictability of the nucleation of metallic vapor at substrate surfaces.

  3. Immediate fabrication of flower-like graphene oxide by ion beam bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Junjie [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Division of Nanobiomedicine, Key Laboratory for Nano-Bio Interface Research, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China); Zhang, Yuanyuan; Zhang, Guilong [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Xiong, Shiquan [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Pei, Renjun, E-mail: rjpei2011@sinano.ac.cn [Division of Nanobiomedicine, Key Laboratory for Nano-Bio Interface Research, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China); Cai, Dongqing, E-mail: dqcai@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Wu, Zhengyan, E-mail: zywu@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China)

    2015-12-01

    Graphical abstract: - Highlights: • Ion beam bombardment (IBB) could modify the microstructure of graphene oxide (GO). • IBB could transform a compact multi-layered GO to a few-layered flower-like GO. • IBB could effectively improve the dispersion and the related properties of GO. • The main mechanism was proposed to be the etching and charge effects of IBB. - Abstract: An effective and convenient method using ion beam bombardment (IBB) for separating a multi-layered compact graphene oxide (GO) piece into several small few-layered loose pieces was developed, and it was found that those small GO pieces had formed a flower-like structure. Therein, the main mechanism was proposed to be the etching and charge effects of IBB. This work could provide a facile and promising approach for improving the dispersion and the related properties of GO. Furthermore, X-ray diffraction and Raman spectrum determinations demonstrated that, with the increasing fluence, IBB could effectively decrease the chemical groups in the layers of GO, resulting in the decrease of the layer distance.

  4. Angular distribution of GaAs sputtered under oblique Cs{sup +} bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Verdeil, C. [Department ' Science and Analysis of Materials' (SAM), Centre de Recherche Public - Gabriel Lippmann, 41 rue du Brill, L-4422 Belvaux (Luxembourg); Wirtz, T. [Department ' Science and Analysis of Materials' (SAM), Centre de Recherche Public - Gabriel Lippmann, 41 rue du Brill, L-4422 Belvaux (Luxembourg)], E-mail: wirtz@lippmann.lu; Scherrer, H. [Laboratoire de Physique des Materiaux, Ecole des Mines, Parc de Saurupt, F-54042 Nancy Cedex (France)

    2009-08-15

    The angular distribution of Ga and As sputtered from Gallium Arsenide (1 0 0) by a Cs{sup +} ion beam was experimentally measured through a collector technique allowing modifications of the energy and incidence angle of the ion beam. The impact energy was varied in the range of 2-10 keV and the angle of incidence from 30 deg. to 60 deg. The angular distributions of emitted matter are determined by means of SIMS depth profiles. Our series of experiments show an evolution of the preferential direction of emission as well as the spreading around this direction in function of the characteristics of the ion beam. The second objective is the study of the evolution of the stoichiometry of the deposit in function of the emission angle. A decrease of the As/Ga ratio around the preferential direction of emission and an increase of this ratio for oblique emission are observed for different conditions of primary bombardment. Considering that the angular distribution depends on the depth of origin, our results suggest that the Cs{sup +} bombardment changes the stoichiometry of the near-surface layers of the sample with an enrichment of As in the outmost layers while the sub-surface region is impoverished in As due to preferential sputtering.

  5. Light emission of sputtered particles induced by ion bombardment on water-enriched molecular ices

    Science.gov (United States)

    Lee, Chin Shuang; Ip, Wing; Liu, S. H.; Hsu, G. Y.; Lee, Shyong

    2007-03-01

    We had measured the light of sputtered particles in a visible region induced by various projectiles bombarding water-enriched molecular ices, like mixed ices of CH4 + NH3 + H2O (1:1:1). In this experiment, each constituent contained in this iced sample was found to emit a characteristic wavelength of light. We believe this characteristic is due to certain ion attached to parent molecule (constituent) that are dissociated with parent molecule in the collision process. Some of those ions, before emerging out the iced film, will become neutralized and develop into excited states due to electron capture. Then the characteristic wavelengths of light will decay from these excited sputtered particles; hence, from the light emission, one can analyze the constituents of an unknown ice. On the other hand, the intensity of the distribution of light emission during ion bombardment can be interpreted as an ion-ice interaction following the similar collision mechanism as ion-metal interaction, i.e. mainly the linear-cascade collision model.

  6. Ion Fluence and Energy Effects on the Optical Properties of SS Mirrors Bombarded by Hydrogen Ions

    Energy Technology Data Exchange (ETDEWEB)

    Bardamid, A.F. [T. Shevchenko National Univ., Kiev (Ukraine); Belyaeva, A.I. [National Technical Univ. KhPI, Kharkov (Ukraine); Bondarenko, V.N. [NSC KIPT, Kharkov (Ukraine)] (and others)

    2003-04-01

    The effects of hydrogen ion (H{sub 3}{sup +}) bombardment on the optical properties of polycrystal stainless steel (SS) mirrors were investigated. Ellipsometry, profilometry, scanning electron microscopy, angle distribution of scattered light, and spectral reflectance were used to characterize the surfaces. Results for the bombardment of SS mirrors with ions of fixed energy (0.3, 0.65 and 1.5 keV/H), with ion flux density (0.5-2) x 10{sup 20} H/m{sup 2}/s up to fluences of (1.1-4.3) x 10{sup 24} H/m{sup 2} are presented. The data show that the surface roughness rises with both increasing ion energy and ion fluence, and that surface roughening leads to an increase of the scattered light with a corresponding decrease of reflectance at normal incidence. The thickness of the apparent layer, obtained by ellipsometry, was found to rise with increasing ion energy at fixed ion fluence and with increasing ion fluence at fixed ion energy. Possible mechanisms for the ion energy effect on the degradation rate of stainless steel mirrors and the origin of the apparent layer are discussed.

  7. Experiment and analysis on back-bombardment effect in thermionic RF gun

    CERN Document Server

    Kii, T; Ikeda, R; Dong, Z W; Masuda, K; Toku, H; Yoshikawa, K; Yamazaki, T

    2001-01-01

    A serious problem for RF guns with thermionic guns is the back-bombardment effect, which makes the operation of the RF guns unstable owing to the instability of the cathode temperature. To find out how to solve the problem, we tried to evaluate the effect of back-bombardment. We have measured the temperature of cathode surface by an infrared radiation thermometer during the generation of electron beams from our S-band thermionic RF gun with 4.5 cavities. As a consequence, it was found that the temperature of cathode surface increased about 15 deg. C while the beam was on. This implies that current density on cathode surface tends to be unstable because the back-streaming electrons give energy to the cathode. We calculated the amount of the energy transfer by means of an energy-balance equation of thermal transport. Then we compared the result with the total energy of back-streaming electrons calculated by a 2-D particle simulation code KUBLAI. By comparison of two results, we could roughly estimate the energy...

  8. Crater densities within young, large craters on Rhea and Dione: Towards understanding the recent Saturnian bombardment

    Science.gov (United States)

    Rodriguez Sanchez-Vahamonde, Carolina; Rivera-Valentin, Edgard G.; Kirchoff, Michelle

    2017-10-01

    The cratering flux for the inner Solar System is partially constrained by geochronological measurements of returned lunar samples and martian meteorites combined with cratering studies. For the outer Solar System, minimal constraints on the bombardment history are derived from dynamical simulations, historical observations of cometary impacts onto the gas giants, and cratering studies. Here, in order to specifically resolve the cratering flux experienced by the Saturnian system, we use high resolution Cassini Imaging Science Subsystem (ISS) data to conduct crater counts on the floors of young, large craters on Rhea and Dione to investigate their relative crater formation age. These two mid-sized moons of Saturn have been shown to have dissimilar crater distributions, which may imply impacts by different populations. Crater diameter and locations of observed small craters between ~100s of meters to ~10s of kilometers within large craters are recorded, where the limit of the smallest crater observable is constrained by the image resolution. Relative crater ages are compared through their cumulative crater density, and populations via the standard R-plot. Ultimately, crater densities within young, large craters on these moons can be compared with crater ages inferred from crystallinity studies using Cassini VIMS data to refine our understanding of the outer Solar System bombardment.

  9. Ion Back-Bombardment of GaAs Photocathodes Inside DC High Voltage Electron Guns

    CERN Document Server

    Grames, Joseph M; Brittian, Joshua; Charles, Daniel; Clark, Jim; Hansknecht, John; Lynn Stutzman, Marcy; Poelker, Matthew; Surles-Law, Kenneth E

    2005-01-01

    The primary limitation for sustained high quantum efficiency operation of GaAs photocathodes inside DC high voltage electron guns is ion back-bombardment of the photocathode. This process results from ionization of residual gas within the cathode/anode gap by the extracted electron beam, which is subsequently accelerated backwards to the photocathode. The damage mechanism is believed to be either destruction of the negative electron affinity condition at the surface of the photocathode or damage to the crystal structure by implantation of the bombarding ions. This work characterizes ion formation within the anode/cathode gap for gas species typical of UHV vacuum chambers (i.e., hydrogen, carbon monoxide and methane). Calculations and simulations are performed to determine the ion trajectories and stopping distance within the photocathode material. The results of the simulations are compared with test results obtained using a 100 keV DC high voltage GaAs photoemission gun and beamline at currents up to 10 mA D...

  10. Ion Fluence and Energy Effects on the Optical Properties of SS Mirrors Bombarded by Hydrogen Ions

    Science.gov (United States)

    Bardamid, A. F.; Belyaeva, A. I.; Bondarenko, V. N.; Davis, J. W.; Galuza, A. A.; Garkusha, I. E.; Haasz, A. A.; Konovalov, V. G.; Kudlenko, A. D.; Poon, M.; Ryzhkov, I. V.; Solodovchenko, S. I.; Shtan, A. F.; Voitsenya, V. S.; Yakimov, K. I.

    The effects of hydrogen ion (H3+) bombardment on the optical properties of polycrystal stainless steel (SS) mirrors were investigated. Ellipsometry, profilometry, scanning electron microscopy, angle distribution of scattered light, and spectral reflectance were used to characterize the surfaces. Results for the bombardment of SS mirrors with ions of fixed energy (0.3, 0.65 and 1.5 keV/H), with ion flux density >(0.5-2) · 1020 H/m2s up to fluences of (1.1-4.3) · 1024 H}/m2 are presented.  The data show that the surface roughness rises with both increasing ion energy and ion fluence, and that surface roughening leads to an increase of the scattered light with a corresponding decrease of reflectance at normal incidence. The thickness of the apparent layer, obtained by ellipsometry, was found to rise with increasing ion energy at fixed ion fluence and with increasing ion fluence at fixed ion energy.  Possible mechanisms for the ion energy effect on the degradation rate of stainless steel mirrors and the origin of the apparent layer are discussed.

  11. In situ spatial organization of Potato virus A coat protein subunits as assessed by tritium bombardment.

    Science.gov (United States)

    Baratova, L A; Efimov, A V; Dobrov, E N; Fedorova, N V; Hunt, R; Badun, G A; Ksenofontov, A L; Torrance, L; Järvekülg, L

    2001-10-01

    Potato virus A (PVA) particles were bombarded with thermally activated tritium atoms, and the intramolecular distribution of the label in the amino acids of the coat protein was determined to assess their in situ steric accessibility. This method revealed that the N-terminal 15 amino acids of the PVA coat protein and a region comprising amino acids 27 to 50 are the most accessible at the particle surface to labeling with tritium atoms. A model of the spatial arrangement of the PVA coat protein polypeptide chain within the virus particle was derived from the experimental data obtained by tritium bombardment combined with predictions of secondary-structure elements and the principles of packing alpha-helices and beta-structures in proteins. The model predicts three regions of tertiary structure: (i) the surface-exposed N-terminal region, comprising an unstructured N terminus of 8 amino acids and two beta-strands, (ii) a C-terminal region including two alpha-helices, as well as three beta-strands that form a two-layer structure called an abCd unit, and (iii) a central region comprising a bundle of four alpha-helices in a fold similar to that found in tobacco mosaic virus coat protein. This is the first model of the three-dimensional structure of a potyvirus coat protein.

  12. Ion bombardment induced buried lateral growth: the key mechanism for the synthesis of single crystal diamond wafers

    Science.gov (United States)

    Schreck, Matthias; Gsell, Stefan; Brescia, Rosaria; Fischer, Martin

    2017-03-01

    A detailed mechanism for heteroepitaxial diamond nucleation under ion bombardment in a microwave plasma enhanced chemical vapour deposition setup on the single crystal surface of iridium is presented. The novel mechanism of Ion Bombardment Induced Buried Lateral Growth (IBI-BLG) is based on the ion bombardment induced formation and lateral spread of epitaxial diamond within a ~1 nm thick carbon layer. Starting from one single primary nucleation event the buried epitaxial island can expand laterally over distances of several microns. During this epitaxial lateral growth typically thousands of isolated secondary nuclei are generated continuously. The unique process is so far only observed on iridium surfaces. It is shown that a diamond single crystal with a diameter of ~90 mm and a weight of 155 carat can be grown from such a carbon film which initially consisted of 2 · 1013 individual grains.

  13. Low-energy ion beam bombardment effect on the plant-cell-envelope mimetic membrane for DNA transfer

    Energy Technology Data Exchange (ETDEWEB)

    Prakrajang, K., E-mail: k.prakrajang@gmail.com [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sangwijit, K.; Anuntalabhochai, S. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wanichapichart, P. [Membrane Science and Technology Research Center, Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkla 90112 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2012-09-01

    This study is a systematic analysis of the mechanisms involved in ion-beam induced DNA transfer, an important application of ion beam biotechnology. Cellulose membranes were used to mimic the plant cell envelope. Ion beams of argon (Ar) or nitrogen (N) at an energy of 25 keV bombarded the cellulose membranes at fluences ranging from 10{sup 15} to 10{sup 16} ions/cm{sup 2}. The damage to the ion-beam-bombarded membranes was characterized using infrared spectroscopy, a micro tensile test and scanning electron microscopy (SEM). Chain scission was the dominant radiation damage type in the membrane. DNA diffusion across the membrane was significantly increased after ion beam bombardment. The increase in DNA transfer is therefore attributed to chain scission, which increases the permeability by increasing the number of pores in the membrane.

  14. Interaction of oxygen with an AISI 314 stainless steel surface studied by ellipsometry and auger electron spectroscopy in combination with ion bombardment

    NARCIS (Netherlands)

    Stokkers, G.J.; van Silfhout, Arend; Bootsma, G.A.; Fransen, T.; Gellings, P.J.

    1983-01-01

    The influence of pretreatment (ion bombardment) on the initial oxidation of AISI 314 stainless steel has been investigated in ultra high vacuum systems with ellipsometry and Auger electron spectroscopy. The bombardment was carried out with Ar+ ions with energies up to 2.2 keV at various doses and

  15. High energy irradiations simulating cosmic-ray-induced planetary gamma ray production. I - Fe target

    Science.gov (United States)

    Metzger, A. E.; Parker, R. H.; Yellin, J.

    1986-01-01

    Two thick Fe targets were bombarded by a series of 6 GeV proton irradiations for the purpose of simulating the cosmic ray bombardment of planetary objects in space. Gamma ray energy spectra were obtained with a germanium solid state detector during the bombardment, and 46 of the gamma ray lines were ascribed to the Fe targets. A comparison between observed and predicted values showed good agreement for Fe lines from neutron inelastic scattering and spallation reactions, and less satisfactory agreement for neutron capture reactions, the latter attributed to the difference in composition between the Fe target and the mean lunar abundance used in the modeling. Through an analysis of the irradiation results together with continuum data obtained in lunar orbit, it was found that 100 hours of measurement with a current instrument should generate a spectrum containing approximately 20 lines due to Fe alone, with a 2-sigma sensitivity for detection of about 0.2 percent.

  16. Compositional change induced by ion bombardement on binary alloys. [5 KeV Ar+

    Energy Technology Data Exchange (ETDEWEB)

    Morita, K.; Nakamura, H.; Hayashibara, M.; Itoh, N. (Nagoya Univ. (Japan). Dept. of Crystalline Materials Science)

    1982-03-01

    The compositional change, induced by 5 keV Ar/sup +/ ion bombardment, of self-supporting films of Ni-Si (10%) alloy has been studied at elevated temperatures. The results are compared with those of similar studies for Ni-Au alloy and are explained using the previously suggested two-stepped segregation mechanism: the segregation from grain boundaries to the surface and that from the grains to the grain boundaries. The theoretical calculation for the two-stepped mechanism has been made for a thin film and for a thicker material. It is pointed out that the compositional change induced by sputtering of alloys at high temperatures may cause important effects on physical properties of materials.

  17. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Barber, Matthew J.; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk

    2016-06-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, we have applied these algorithms for centroiding of photon events from an electron-bombarded CCD (EBCCD). We find that centroiding algorithms based on iterative fitting of the photon events yield excellent results and allow fitting of overlapping photon events, a feature not reported before and an important aspect to facilitate an increased count rate and shorter acquisition times.

  18. Low temperature magnetron sputter deposition of polycrystalline silicon thin films using high flux ion bombardment

    Science.gov (United States)

    Gerbi, Jennifer E.; Abelson, John R.

    2007-03-01

    We demonstrate that the microstructure of polycrystalline silicon thin films depends strongly on the flux of low energy ions that bombard the growth surface during magnetron sputter deposition. The deposition system is equipped with external electromagnetic coils which, through the unbalanced magnetron effect, provide direct control of the ion flux independent of the ion energy. We report the influence of low energy (thin films onto amorphous substrates. We use spectroscopic ellipsometry, Raman scattering, x-ray diffraction, and cross sectional transmission electron microscopy to analyze the film microstructure. We demonstrate that increasing the flux ratio of Ar+ ions to silicon neutrals (J+/J0) during growth by an order of magnitude (from 3 to 30) enables the direct nucleation of polycrystalline Si on glass and SiO2 coated Si at temperatures below 400°C. We discuss possible mechanisms for this enhancement of crystalline microstructure, including the roles of enhanced adatom mobility and the formation of shallow, mobile defects.

  19. Carbon monoxide production in low energy oxygen ion bombardment of pyrolytic graphite and Kapton surfaces

    Science.gov (United States)

    Horton, C. C.; Eck, T. G.; Hoffman, R. W.

    1986-01-01

    The results of an investigtion of the interaction of low energy oxygen ions with pyrolytic graphite and Kapton surface are reported. CO molecules emitted from the surface as a result of the ion bombardment were detected by a mass spectrometer. Because the ion-induced signals were small compared to that arising from the CO background pressure in the vacuum system, the ion beam was modulated and the modulated component of the CO signal measured with a lock-in amplifier. The quantum yield (CO molecules emitted per incident oxygen ion) for graphite rose from 1.9 at 4.5 eV ion energy to 6.6 at 465 eV. Comparable yields were obtained for Kapton. The large size of the yields suggests contributions to the reaction process from the background O2 molecules in the vacuum system.

  20. Ion-bombardment modification of the surface of mirrors fabricated of ZrTiCuNiBe amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Voitsenya, V S; Konovalov, V G; Kovtun, K V; Naidenkova, D I; Ryzhkov, V I; Shtan' , A F; Solodovchenko, S I; Trembach, O V; Vasil' ev, A A [National Science Center ' KIPT' , 61108 Kharkov (Ukraine); Bardamid, A F [Taras Shevchenko National University, 01033 Kyiv (Ukraine); Belyaeva, A I; Slatin, K A, E-mail: voitseny@ipp.kharkov.u [National Technical University ' KPI' , 61002 Kharkov (Ukraine)

    2010-01-01

    When preparing mirror samples of amorphous metal alloys some inhomogeneities of the structure became to be seen on the surface. These inhomogeneities were modified during bombardment with ions of deuterium and argon plasma. Besides, a new blister-like type of inhomogeneities was found on the mirror surface in one experiment. In the paper a short description of obtained results are presented.

  1. Enhancement of Reflectivity of Multilayer Mirrors for Soft-X-Ray Projection Lithography by Temperature Optimization and Ion-Bombardment

    NARCIS (Netherlands)

    E. Louis,; Voorma, H. J.; Koster, N. B.; Shmaenok, L.; F. Bijkerk,; Schlatmann, R.; Verhoeven, J.; Platonov, Y. Y.; van Dorssen, G. E.; Padmore, H. A.

    1994-01-01

    In this paper we discuss two techniques to optimize the quality of multilayer x-ray mirrors, namely optimization of the temperature of the substrates during deposition and ion-bombardment of the layers. We produced Mo/Si multilayers applying both methods and present the effect on the near normal

  2. Reactive magnetron sputtering of highly (001)-textured WS{sub 2-x} films: Influence of Ne{sup +}, Ar{sup +} and Xe{sup +} ion bombardment on the film growth

    Energy Technology Data Exchange (ETDEWEB)

    Ellmer, K.; Seeger, S.; Sieber, I. [Hahn-Meitner-Institut Berlin, Dept. Solare Energetik, Glienicker Str. 100, 14109 Berlin (Germany); Bohne, W.; Roehrich, J.; Strub, E. [Hahn-Meitner-Institut Berlin, Dept. Ionenstrahllabor, Glienicker Str. 100, 14109 Berlin (Germany); Mientus, R. [Opto-Transmitter-Umweltschutz-Technologie e.V., Koepenicker Str. 325b, 12555 Berlin (Germany)

    2006-02-01

    Layer-type van der Waals semiconductor WS{sub 2-x} films were grown by radio frequency reactive magnetron sputtering from a metallic tungsten target onto oxidized silicon substrates. The sputtering atmosphere consisted of 75% hydrogen sulfide and 25% neon, argon or xenon. The substrate voltage and hence the energy of the ions bombarding the growing film, was varied from about 20 V (floating potential) to -80 V. By in situ energy-dispersive X-ray diffraction the growth of the films was monitored and by elastic recoil detection analysis the film composition was measured. It was found that with xenon in the sputtering atmosphere a substrate voltage of -20 V is sufficient to suppress the crystalline film growth, while for argon as the sputtering rare gas this occurs only at -80 V. The disturbed film growth is accompanied by a sulfur loss of the growing WS{sub 2-x} films down to x = 1.1 for sputtering in Ar + H{sub 2}S at a substrate potential of -60 V. The results are tentatively explained by the different momentum transfers to sulfur atoms, which is highest for argon ions. It has also to be taken into account that the low-energy xenon bombardment is a many-body cascade process with a much higher local energy density compared to argon and neon bombardment and leading to a higher defect density and a supression of the crystalline growth. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Bacterial spore survival after exposure to HZE particle bombardment -implication for the lithopanspermia hypothesis.

    Science.gov (United States)

    Moeller, Ralf; Berger, Thomas; Matthiä, Daniel; Okayasu, Ryuichi; Kitamura, H.; Reitz, Guenther

    Based on their unique resistance to various space parameters, bacterial spores (mainly spores of Bacillus subtilis) are one of the model systems used for astrobiological studies. More re-cently, spores of B. subtilis have been applied for experimental research on the likelihood of interplanetary transfer of life. Since its first postulation by Arrhenius in 1903, the pansper-mia hypothesis has been revisited many-times, e.g. after the discovery of several lunar and Martian meteorites on Earth [1,2]. These information provided intriguing evidence that rocks may naturally be transferred between the terrestrial planets. The scenario of panspermia, now termed "lithopanspermia" involves three basic hypothetical steps: (i) the escape process, i.e. removal to space of biological material, which has survived being lifted from the surface to high altitudes; (ii) interim state in space, i.e., survival of the biological material over time scales comparable with interplanetary or interstellar passage; (iii) the entry process, i.e. nondestruc-tive deposition of the biological material on another planet [2]. In our research, spores of B. subtilis were used to study the effects of galactic cosmic radiation on spore survival and induced mutations. On an interplanetary journey, outside a protective magnetic field, spore-containing rocks would be exposed to bombardment by high-energy charged particle radiation from galac-tic sources and from the sun. Air-dried spore layers on three different host materials (i.e., non-porous igneous rocks (gabbro), quartz, and spacecraft analog material (aluminum)) were irradiated with accelerated heavy ions (Helium and Iron) with a LET (linear energy transfer) ˆ of 2 and 200 keV/Am, at the Heavy Ion Medical Accelerator (HIMAC) at the National In-stitute of Radiological Sciences, (NIRS), Chiba, Japan in the frame of the HIMAC research project 20B463 "Characterization of heavy ion-induced damage in Bacillus subtilis spores and their global

  4. Treatment of PVC using an alternative low energy ion bombardment procedure

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, Elidiane C., E-mail: elidiane@sorocaba.unesp.br [Laboratorio de Plasmas Tecnologicos, Universidade Estadual Paulista, Campus Experimental de Sorocaba, Av. Tres de Marco, 511 Alto da Boa Vista, 18087-180, Sorocaba, SP (Brazil); Santos, Nazir M. dos; Bortoleto, Jose Roberto R.; Durrant, Steven F. [Laboratorio de Plasmas Tecnologicos, Universidade Estadual Paulista, Campus Experimental de Sorocaba, Av. Tres de Marco, 511 Alto da Boa Vista, 18087-180, Sorocaba, SP (Brazil); Schreiner, Wido H. [Laboratorio de Interfaces e Filmes Finos, Universidade Federal de Parana (UFPR), C.P. 19044, 81531-990, Curitiba, PR (Brazil); Honda, Roberto Y. [Laboratorio de Plasmas, Universidade Estadual Paulista (UNESP), Departamento de Fisica e Quimica, 12516-410, Guaratingueta, SP (Brazil); Cassia C Rangel, Rita de; Cruz, Nilson C. [Laboratorio de Plasmas Tecnologicos, Universidade Estadual Paulista, Campus Experimental de Sorocaba, Av. Tres de Marco, 511 Alto da Boa Vista, 18087-180, Sorocaba, SP (Brazil)

    2011-12-15

    In many applications, polymers have progressively substituted traditional materials such as ceramics, glasses, and metals. Nevertheless, the use of polymeric materials is still limited by their surface properties. Frequently, selective modifications are necessary to suit the surface to a given application. Amongst the most common treatments, plasma immersion ion implantation (PIII) has attracted the attention of many researchers owing to its versatility and practicality. This method, however, requires a power supply to provide high voltage (tens of kV) negative pulses, with a controlled duty cycle, width and frequency. Owing to this, the implementation of PIII on the industrial scale can become economically inviable. In this work, an alternative plasma treatment that enables low energy ion bombardment without the need of a high voltage pulse generator is presented. To evaluate the efficiency of the treatment of polymers, polyvinylchloride, PVC, specimens were exposed to 5 Pa argon plasmas for 3600 s, at excitation powers, P, of between 10 and 125 W. Through contact angle and atomic force microscopy data, the influence of P on the wettability, surface free energy and roughness of the samples was studied. Surface chemical composition was measured by X-ray photoelectron spectroscopy, XPS. To evaluate the effect of aging under atmospheric conditions, contact angle and XPS measurements were performed one and 1334 days after the treatment. The plasma potential and ion density around the driven electrode were determined from Langmuir probe measurements while the self-bias potential was derived with the aid of an oscilloscope. From these data it was possible to estimate the mean energy of ions bombarding the PVC surface. Chlorine, carbon and oxygen contamination were detected on the surface of the as-received PVC. Upon exposure to the plasma, the proportion of chlorine was observed to decrease while that of oxygen increased. Consequently, the wettability and surface energy

  5. Saturn’s ring age from bombardment simulation and reflectance fit to Cassini UVIS spectra

    Science.gov (United States)

    Elliott, Joshua Peter; Esposito, Larry; Bradley, Eric Todd

    2017-10-01

    The age of Saturn’s rings is open question. Our understanding of this question depends heavily on the rate at which infalling meteoritic material impacts the rings, which is a matter of some debate. Recent estimates of this mass flux are between an order of magnitude higher and lower than the estimate given by Cuzzi and Estrada 1998. Given this range, we perform a meteoritic bombardment simulation, using our stochastic Markov-chain based model, which yields fractional-pollution curves over time for the B and C rings of Saturn. Next, using Hapke’s 2012 model for bidirectional reflectance for an intimate mixture of water-ice and pollutant grains, we perform a non-linear least-squares fit to Cassini UVIS data with two free parameters, fractional pollution and surface roughness of the ring particles, with a correction for the optical depth of the rings, to determine the estimated fractional pollution observed by UVIS. We perform this fit with two pollutants, amorphous carbon, and cometary material measured by the Rosetta Alice UV spectrometer of comet 67P/Churyumov-Gerasimenko. The fractional pollution value returned by our fit is then used to interpolate ring age along the fractional pollution curves returned by our Markov-chain simulation.

  6. Characterization of CdZnTe after argon ion beam bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Bensalah, H., E-mail: hakima.bensalah@uam.es [Departamento de Fisica de Materiales, Laboratorio de Crecimiento de Cristales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Hortelano, V. [GdS-Optronlab Group, Departamento Fisica Materia Condensada, Universidad de Valladolid, Edificio I-D, Paseo de Belen 1, 47011 Valladolid (Spain); Plaza, J.L. [Departamento de Fisica de Materiales, Laboratorio de Crecimiento de Cristales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Martinez, O. [GdS-Optronlab Group, Departamento Fisica Materia Condensada, Universidad de Valladolid, Edificio I-D, Paseo de Belen 1, 47011 Valladolid (Spain); Crocco, J.; Zheng, Q.; Carcelen, V.; Dieguez, E. [Departamento de Fisica de Materiales, Laboratorio de Crecimiento de Cristales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2012-12-05

    Highlights: Black-Right-Pointing-Pointer After argon irradiation using low fluence, the defects on surface were removed. Black-Right-Pointing-Pointer The PL intensity increases after irradiation. This increase should be related to the improved quality of the CdZnTe surfaces. Black-Right-Pointing-Pointer Irradiation process lead to an elimination of Te precipitates from the surfaces of the CdZnTe samples. - Abstract: The objective of this work is to analyze the effects of argon ion irradiation process on the structure and distribution of Te inclusions in Cd{sub 1-x}Zn{sub x}Te crystals. The samples were treated with different ion fluences ranging from 2 to 8 Multiplication-Sign 10{sup 17} cm{sup -2}. The state of the samples before and after irradiation were studied by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Cathodoluminescence, Photoluminescence, and micro-Raman spectroscopy. The effect of the irradiation on the surface of the samples was clearly observed by SEM or AFM. Even for small fluences a removal of polishing scratches on the sample surfaces was observed. Likely correlated to this effect, an important enhancement in the luminescence intensity of the irradiated samples was observed. An aggregation effect of the Te inclusions seems to occur due to the Ar bombardment, which are also eliminated from the surfaces for the highest ion fluences used.

  7. Modeling of evolution of shape of ductile metal disk for isotropic bombardment

    Science.gov (United States)

    Osipov, Dulustaan R.; Yakovlev, Boris V.; Matveev, Andrei I.; Osipov, Dulustan A.

    2017-11-01

    This work is devoted to a calculation of formation time of a toroidal shape of a flat piece of ductile metal in enrichment of minerals. Gold grains occurring in nature, in most cases, originally have a form of a flat plate (the scaly form). Continuous bombardment of the surface of a piece of gold with surrounding grains of sand during the enrichment of ores in various jigging, separation, and crusher devices results in the piece assuming a toroidal shape. When separating, the shape of the grains in the form of a torus is considered to be the most effective. Therefore, the problem of calculation of the formation time of the toroidal shape of the piece of gold is urgent. In this paper, we propose a physical model for the formation of the toroidal shape of the piece of ductile metal, in which an isotropic, homogeneous flow of particles deforming a plane body (disk) is introduced. Based on the proposed physical model, a mathematical model of evolution of the surface under deformation of a body was developed. A first-order differential equation is obtained with respect to the deformable surface, which is solved by the Runge-Kutta method. As a result of the study, the dependence of the deformed surface on the time was determined.

  8. Electronic and Optical Properties of Aluminum Oxide Before and After Surface Reduction by Ar+ Bombardment

    Directory of Open Access Journals (Sweden)

    D. Tahir

    2014-08-01

    Full Text Available The electronic and optical properties of a-Al2O3 after induced by 3-keV Ar+ sputtering have been studied quantitatively by use of reflection electron energy loss spectroscopy (REELS spectra. The band gap values of a-Al2O3 was determined from the onset values of the energy loss spectrum to the background level of REELS spectra as a function of time Ar+ bombardment. The bandgap changes from 8.4 eV before sputtering to 6.2 eV after 4 minutes of sputtering.The optical properties of α-Al2O3 thin films have been determined by comparing the experimental cross section obtained from reflection electron energy loss spectroscopy with the theoretical inelastic scattering cross section, deduced from the simulated energy loss function (ELF by using QUEELS-ε(k-REELS software. The peak assignments are based on ELF and compared with reported data on the electronic structure of α-Al2O3 obtained using different techniques. The results demonstrate that the electronic and optical properties before and after surface reduction will provide further understanding in the fundamental properties of α-Al2O3 which will be useful in the design, modeling and analysis of devices applications performance.

  9. Electron-bombarded 〈110〉-oriented tungsten tips for stable tunneling electron emission

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, T. K.; Abe, T.; Nazriq, N. M. K.; Irisawa, T. [Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)

    2016-03-15

    A clean tungsten (W) tip apex with a robust atomic plane is required for producing a stable tunneling electron emission under strong electric fields. Because a tip apex fabricated from a wire by aqueous chemical etching is covered by impurity layers, heating treatment in ultra-high vacuum is experimentally known to be necessary. However, strong heating frequently melts the tip apex and causes unstable electron emissions. We investigated quantitatively the tip apex and found a useful method to prepare a tip with stable tunneling electron emissions by controlling electron-bombardment heating power. Careful characterizations of the tip structures were performed with combinations of using field emission I–V curves, scanning electron microscopy, X-ray diffraction (transmitted Debye-Scherrer and Laue) with micro-parabola capillary, field ion microscopy, and field emission microscopy. Tips were chemically etched from (1) polycrystalline W wires (grain size ∼1000 nm) and (2) long-time heated W wires (grain size larger than 1 mm). Heating by 10-40 W (10 s) was found to be good enough to remove oxide layers and produced stable electron emission; however, around 60 W (10 s) heating was threshold power to increase the tip radius, typically +10 ± 5 nm (onset of melting). Further, the grain size of ∼1000 nm was necessary to obtain a conical shape tip apex.

  10. Influence of particle bombardment on microstructure and internal stresses of refractory metal suicides on silicon

    Science.gov (United States)

    Hardtke, Ch.; Schilling, W.; Ullmaier, H.

    1991-07-01

    First results on microstructural changes and stress relaxation in thin refractory metal suicide films (TaSi 2 and MoSi 2) caused by particle bombardment are reported. The polycrystalline films had initial tensile stresses of some 10 9 Pa. Exposed to irradiation with Ge ions of 400 keV, both suicides showed a similar stress relaxation behaviour as a function of dose. During room-temperature implantation the initial tensile stress rapidly decreased and turned into compressive stress. Continuous irradiation partly relaxed the compressive stress and resulted in a saturation value of some -10 8 Pa. With increasing implantation temperature, the buildup of compressive stress gradually vanished, leaving only the initial decrease of tensile stress which finally approached zero. Based on microstructural investigations (TEM and X-ray diffraction) it is proposed to explain this behaviour by the combined action of two processes: relaxation of tensile stress by a volume increase due to irradiation-induced amorphization, and Frenkel defect production and relaxation of compressive stress by irradiation-induced densification of amorphous regions and/or Frenkel defect elimination.

  11. Improvement of the magnetron sputtered coating adhesion through pulsed bombardment by high-energy ions

    Science.gov (United States)

    Melnik, Yu A.; Metel, A. S.

    2017-05-01

    Comparative study of titanium nitride deposition has been carried out, the growing coating being uninterruptedly bombarded by 100-eV ions or ions accelerated by high-voltage pulses applied to the substrate. The study revealed that microhardness of coatings synthesized using 25-kV pulses rises from 21 GPa to 29 GPa when percentage of nitrogen in the mixture with argon increases from 15% to 20%. With a further increase of nitrogen percentage to 30%, the microhardness slightly diminishes to 27 GPa. In contrast to golden coatings synthesized at low-voltage substrate biasing, the color of titanium nitride coating produced using high-voltage pulses is brown. The most striking difference of coating deposited using high-voltage pulses applied to the substrate is its perfect adhesion despite the interface formation at the room temperature without any preheating and activation. The adhesion characterization using a scratch-tester has revealed that critical loads of coatings synthesized using 25-kV pulses are several times higher than those of conventional nitride coatings synthesized at uninterrupted substrate biasing of 100 V. When the pulse amplitude diminishes to 5 kV, the critical loads and microhardness of the coating decrease to conventional values.

  12. ULTRAVIOLET AND INFRARED SPECTRA OF ELECTRON-BOMBARDED SOLID NITROGEN AND METHANE DILUTED IN SOLID NITROGEN

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yu-Jong; Chuang, Shiang-Jiun; Huang, Tzu-Ping [National Synchrotron Radiation Research Center, No. 101, Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Chen, Hui-Fen, E-mail: yjwu@nsrrc.org.tw [Department of Medical and Applied Chemistry, Kaohsiung Medical University, 100, Shih-Chuan 1 st Road, Kaohsiung 80708, Taiwan (China)

    2013-05-01

    The infrared (IR) and ultraviolet (UV) absorption spectra of pure solid N{sub 2} and CH{sub 4} diluted in solid N{sub 2} (1/100) irradiated with energetic electrons at 10 K were obtained. The IR absorption measurements of the electron-bombarded pure N{sub 2} solid reveal the formation of N{sub 3} and N{sub 3} {sup +}, which was confirmed by the observed electronic transitions A {sup 2}{Sigma}{sub u} {sup +}<- X {sup 2}{Pi}{sub g} of N{sub 3} and A {sup 3}{Pi}{sub u} <- X {sup 3}{Sigma}{sub g} {sup -} of N{sub 3} {sup +}. In the case of N{sub 2} ice containing a small proportion of CH{sub 4}, we have identified the products of irradiated CH{sub 4}/N{sub 2} ice, including N{sub 3}, C{sub n} N (n = 1-3), CN{sub 2}, (CN){sub 2}, CH{sub 3}N, HCN{sub 2}, HC{sub 2}N, C(NH){sub 2}, HNC, HCN, CH{sub 3}, C{sub 2}H, C{sub 2}H{sub 2}, CN{sup -}, NH{sub 3} {sup +}, and HC{sub 3}N{sup +}. UV absorption measurement of the ice sample was carried out and the possible carriers associated with the observed absorption bands were assigned and discussed.

  13. Characteristics of radiation damage in silicon bombarded with U/sup 235/ fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Takibaev, Z.S.; Gorelkinskii, Y.V.; Grishchenko, V.F.; Gerasimenko, N.N.

    1975-10-01

    The ESR method was used in a study of the properties of radiation defects in silicon bombarded with /sup 235/U fission fragments. The source of these fragments was uranium dioxide irradiated, together with silicon, by reactor neutrons. It was established that the main defects generated by fission fragments were tetravacancies (called Si--P3 centers) and centers associated with amorphization (VV centers). An analysis of the distribution function of the concentration of paramagnetic centers demonstrated that individual fission fragments were capable of creating point defects in densities sufficient for the formation of an isolated amorphous region in Si. A continuous amorphous layer near the surface of an Si crystal was observed when the fission fragment density was approx.10/sup 15/ cm/sup -2/. An estimate was obtained of the rate of introduction of paramagnetic centers whose average value was approx.10/sup 4/ cm/sup -1/ per fragment. The ESR signal disappeared completely after annealing at approx.600/sup 0/C. (AIP)

  14. Biological Effects of Low Energy Ar+ Ion Bombardment on Silkworm Eggs: a Novel Animal Model

    Science.gov (United States)

    Xu, Jiaping; Wu, Yuejin; Liu, Xuelan; Yuan, Hang; Yu, Zengliang

    2009-06-01

    In this study, we found for the first time that silkworm eggs were able to survive in vacuum for a long period of time. Subsequently, low energy Ar+ ions with different energies and fluences were used to bombard silkworm eggs so as to explore the resulting biological effects. Results showed that (i) the exposure of silkworm eggs to vacuum within 10 min did not cause significant impact on the hatching rates, while the irradiation of silkworm eggs by Ar+ ions of 25 keV or 30 keV with fluences ranging from 2.6×2.6 × 1015 ion/cm2 to 8×2.6 × 1015 ion/cm2 caused a significant impact on the hatching rates, and the hatching rates decreased with the increase in the fluence and energy level; (ii) the irradiation of silkworm eggs by Ar+ ions of 30 keV with a fluence of 8×2.6 × 1015 ion/cm2 or 9×2.6 × 1015 ion/cm2 resulted in a noticeable etching on the egg shell surface which could be observed by a scanning electron microscope; and (iii) the irradiation of silkworm eggs by Ar+ ions of 30 keV with a fluence of 9×2.6 × 1015 ion/cm2 generated several mutant phenotypes which were observed in the 5th instar silkworms and a moth.

  15. Low-energy ion bombardment to tailor the interfacial and mechanical properties of polycrystalline 3C-silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Liu Fang; Li, Carolina H.; Pisano, Albert P.; Carraro, Carlo; Maboudian, Roya [Department of Chemical Engineering and Berkeley Sensor and Actuator Center, University of California, Berkeley, Berkeley, California 94720 and Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230027 (China); Department of Chemical Engineering, University of California, Berkeley, Berkeley, California 94720 (United States); Department of Mechanical Engineering and Berkeley Sensor and Actuator Center, University of California, Berkeley, Berkeley, California 94720 (United States); Department of Chemical Engineering and Berkeley Sensor and Actuator Center, University of California, Berkeley, Berkeley, California 94720 (United States)

    2010-09-15

    Low-energy Ar{sup +} ion bombardment of polycrystalline 3C-silicon carbide (poly-SiC) films is found to be a promising surface modification method to tailor the mechanical and interfacial properties of poly-SiC. The film average stress decreases as the ion energy and the bombardment time increase. Furthermore, this treatment is found to change the strain gradient of the films from positive to negative values. The observed changes in stress and strain gradient are explained by ion peening and thermal spikes models. In addition, the poly-SiC films show a significant enhancement in corrosion resistance by this treatment, which is attributed to a reduction in surface energy and to an increase in the compressive stress in the near-surface region.

  16. Photon counting imaging with an electron-bombarded CCD: Towards wide-field time-correlated single photon counting (TCSPC)

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Jiggins, Stephen; Sergent, Nicolas; Zanda, Gianmarco; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk

    2015-07-01

    Single photon detecting capabilities of an electron-bombarded CCD (EBCCD), where a photon is converted into a photoelectron that is accelerated through a high voltage before hitting the CCD chip, were characterised. The photon event pulse height distribution was found to be linearly dependent on the gain voltage. Based on these results, we propose that a gain voltage sweep during exposure in an EBCCD or EBCMOS camera would allow photon arrival time determination from the photon event pulse height with sub-frame exposure time resolution. This effectively uses an electron-bombarded sensor as a parallel-processing photoelectronic time-to-amplitude converter (TAC), or a 2-dimensional streak camera. Several applications that require timing of photon arrival, including fluorescence lifetime imaging microscopy (FLIM), may benefit from this approach. Moreover, the EBCCD was used on a fluorescence microscope to image fluorescently labelled cells in single photon counting mode.

  17. X-ray absorption and magnetic circular dichroism studies of ion-bombarded ferromagnet-antiferromagnet bilayers

    Science.gov (United States)

    Schmalhorst, J.; Sacher, M.; Höink, V.; Reiss, G.; Engel, D.; Ehresmann, A.

    2004-11-01

    The influence of He ion bombardment on the structural and magnetic interface properties of a polycrystalline Mn83Ir17/Co antiferromagnet-ferromagnet bilayer system is investigated. For annealed as well as for not annealed samples an exchange bias field of up to 200Oe is induced by the ion bombardment for doses up to 5×1014ions/cm2 . The x-ray absorption and the x-ray magnetic circular dichroism of Co and Mn is not significantly altered by this ion dose. For higher doses the exchange bias field is strongly reduced and accompanied by an increase of the ratio of the Mn to Co x-ray absorption intensities and a reduction of the Co x-ray magnetic circular dichroism signal. A model with a Gaussian-like intermixing zone at the AF/FM interface is developed to account for the observed changes of the x-ray absorption spectra.

  18. ISOLDE back on target

    CERN Multimedia

    Anaïs Schaeffer

    2014-01-01

    Today, Friday 1 August, the ISOLDE installation, supplied by the beams of the PS Booster, restarted its physics programme. After a shutdown of almost a year and a half, there was a real buzz in the air as the first beam of protons hit the target of the first post-LS1 ISOLDE experiment.   One of the new target-handling robots installed by ISOLDE during LS1. Many improvements have been made to the ISOLDE installation during LS1. One of the main projects was the installation of new robots for handling the targets (see photo 1). “Our targets are bombarded by protons from the PS Booster’s beams and become very radioactive,” explains Maria Jose Garcia Borge, spokesperson for the ISOLDE collaboration. “They therefore need to be handled carefully, which is where the robots come in. The robots we had until now were already over 20 years old and were starting to suffer from the effects of radiation. So LS1 was a perfect opportunity to replace them with more moder...

  19. Deep inelastic reactions of /sup 32/S on /sup 27/Al at 130 MeV bombarding energy

    Energy Technology Data Exchange (ETDEWEB)

    Manduchi, C.; Russo-Manduchi, M.T.; Segato, G.F.; Andolfato, F.

    1985-10-01

    Deep inelastic reactions induced by /sup 32/S bombardment on /sup 27/Al were studied at 130 MeV incident energy. The experiment employed a coincidence spectrometer consisting of two ion chambers which measured the energy, position and nuclear charge of the heavy reaction products. Inclusive fragment measurements and fragment-fragment coincidences have been used to determine the production of fragments of different Z, and related Q-value distributions. (orig.).

  20. Fast atom bombardment mass spectrometric and tandem mass spectrometric studies of some functionalized tetrapyrroles derived from chlorophylls a and b

    Energy Technology Data Exchange (ETDEWEB)

    Keely, B.J.; Maxwell, J.R. (Univ. of Bristol (England))

    Fast atom bombardment (FAB) mass spectra of a number of functionalized tetrapyrroles derived from chlorophylls a and b have been obtained and MS/MS studies used to investigate aspects of the fragmentation behavior of some of them. The application of this approach is demonstrated by the assignment of pheophytin b isolated from a lake sediment where the amount and purity were insufficient for {sup 1}H nuclear magnetic resonance spectroscopic studies.

  1. Impact Characteristics of Different Rocks in a Pulsed Laser Irradiation Experiment: Simulation of Micrometeorite Bombardment on the Moon

    Science.gov (United States)

    Wu, Yanxue; Li, Xiongyao; Yao, Wenqing; Wang, Shijie

    2017-10-01

    Without the protection of the atmosphere, the soils on lunar surfaces undergo a series of optical, physical, and chemical changes during micrometeorite bombardment. To simulate the micrometeorite bombardment process and analyze the impact characteristics, four types of rocks, including terrestrial basalt and anorthosite supposed to represent lunar rock, an H-type chondrite (the Huaxi ordinary chondrite), and an iron meteorite (the Gebel Kamil iron meteorite) supposed to represent micrometeorite impactors, are irradiated by a nanosecond pulse laser in a high vacuum chamber. Based on laser irradiation experiments, the laser pits are found to be of different shapes and sizes which vary with the rock type. Many melt and vapor deposits are found on the mineral surfaces of all the samples, and nanophase iron (npFe) or Fe-Ni alloy particles are typically distributed on the surfaces of ilmenite, kamacite, or other minerals near kamacite. By analyzing the focused ion beam ultrathin slices of laser pits with a transmission electron microscope, the results show that the subsurface structures can be divided into three classes and that npFe can be easily found in Fe-bearing minerals. These differences in impact characteristics will help determine the source material of npFe and infer the type of micrometeorite impactors. During micrometeorite bombardment, in the mare regions, the npFe are probably produced simultaneously from lunar basalt and micrometeorites with iron-rich minerals, while the npFe in the highlands regions mainly come from micrometeorites.

  2. Photon counting imaging with an electron-bombarded CCD: Towards a parallel-processing photoelectronic time-to-amplitude converter

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Jiggins, Stephen; Sergent, Nicolas; Zanda, Gianmarco; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom)

    2014-12-15

    We have used an electron-bombarded CCD for optical photon counting imaging. The photon event pulse height distribution was found to be linearly dependent on the gain voltage. We propose on this basis that a gain voltage sweep during exposure in an electron-bombarded sensor would allow photon arrival time determination with sub-frame exposure time resolution. This effectively uses an electron-bombarded sensor as a parallel-processing photoelectronic time-to-amplitude converter, or a two-dimensional photon counting streak camera. Several applications that require timing of photon arrival, including Fluorescence Lifetime Imaging Microscopy, may benefit from such an approach. A simulation of a voltage sweep performed with experimental data collected with different acceleration voltages validates the principle of this approach. Moreover, photon event centroiding was performed and a hybrid 50% Gaussian/Centre of Gravity + 50% Hyperbolic cosine centroiding algorithm was found to yield the lowest fixed pattern noise. Finally, the camera was mounted on a fluorescence microscope to image F-actin filaments stained with the fluorescent dye Alexa 488 in fixed cells.

  3. Structure determination of adipokinetic hormones using fast atom bombardment tandem mass spectrometry; An unknown adipokinetic hormone (AKH-III) from Locusta migratoria

    Energy Technology Data Exchange (ETDEWEB)

    Heerma, W.; Versluis, C.; Lankhof, H. (Utrecht University (Netherlands). Faculty of Chemistry, Department of Analytical Molecular Spectrometry); Oudejans, R.C.H.M.; Kooiman, F.P.; Beenakkers, A.M.T. (Utrecht University (Netherlands). Department of Experimental Zoology)

    1991-08-01

    Fast atom bombardment mass spectrometry combined with various tandem mass spectrometric techniques and accurate mass measurement were used to elucidate the structure of an unknown biologically active peptide isolated from Locusa migratoria. (author). 23 refs.; 6 figs.; 2 schemes.

  4. Między znaczeniem leksykalnym a walencją – próba opracowania metody ekstrakcji ekwiwalentów na podstawie korpusu równoległego

    Directory of Open Access Journals (Sweden)

    Elżbieta Kaczmarska

    2015-06-01

    Full Text Available Between lexical meaning and valency – towards a method for extracting equivalents based on a parallel corpus Some entries in translation dictionaries (even in those for closely related languages offer multiple target equivalents with disparate meanings even when the meaning of the source word is not considered ambiguous within the source language. The translator’s task of choosing the best fitting text unit is made even more difficult by sparse exemplification and missing or sketchy valency information. Using a parallel corpus, we explore to what extent valency (seen in a broad sense both as a syntactic and semantic property can help to cope with a few difficult cases of Czech psych verbs in relation to Polish and how the lexical caps can be filled. Next, we compare the manually compiled lists of translation equivalents in context, annotated and sorted by their valency properties, with results of an automatic method, using word-to-word alignments in a lemmatised parallel corpus to build a list of equivalent pairs, annotated by their frequency. We conclude that valency is an important (though not omnipotent discriminant for the choice of the target equivalent and that the list of translation pairs extracted automatically from a parallel corpus can be a useful supplement to a standard translation dictionary.

  5. Seduction of Finding Universality in Sputtering Yields Due to Cluster Bombardment of Solids.

    Science.gov (United States)

    Paruch, Robert J; Postawa, Zbigniew; Garrison, Barbara J

    2015-09-15

    Universal descriptions are appealing because they simplify the description of different (but similar) physical systems, allow the determination of general properties, and have practical applications. Recently, the concept of universality has been applied to the dependence of the sputtering (ejection) yield due to energetic cluster bombardment versus the energy of the incident cluster. It was observed that the spread in data points can be reduced if the yield Y and initial projectile cluster kinetic energy E are expressed in quantities scaled by the number of cluster atoms n, that is, Y/n versus E/n. The convergence of the data points is, however, not perfect, especially when the results for molecular and atomic solids are compared. In addition, the physics underlying the apparent universal dependence in not fully understood. For the study presented in this Account, we performed molecular dynamics simulations of Arn cluster bombardment of molecular (benzene, octane, and β-carotene) and atomic (Ag) solids in order to address the physical basis of the apparent universal dependence. We have demonstrated that the convergence of the data points between molecular and atomic solids can be improved if the binding energy of the solid U0 is included and the dependence is presented as Y/(E/U0) versus (E/U0)/n. As a material property, the quantity U0 is defined per the basic unit of material, which is an atom for atomic solids and a molecule for molecular solids. Analogously, the quantity Y is given in atoms and molecules, respectively. The simulations show that, for almost 3 orders of magnitude variation of (E/U0)/n, there are obvious similarities in the ejection mechanisms between the molecular and atomic solids, thus supporting the concept of universality. For large (E/U0)/n values, the mechanism of ejection is the fluid flow from a cone-shaped volume. This regime of (E/U0)/n is generally accessed experimentally by clusters with hundreds of atoms and results in the largest

  6. Ages of Martian basins and their implication for the end of the heavy bombardment

    Science.gov (United States)

    Werner, S. C.; Neukum, G.

    2003-04-01

    Global stratigraphic schemes for planetary bodies are usually based on the most common resurfacing process: the impacts of planetesimals which remain as craters or crater-related features on planetary surfaces. Through this random cratering process, counting of the accumulated number of impact craters on planetary surface units offers a valuable procedure in understanding the chronostratigraphy of a certain object. Recent ground-based observational data indicate a wavy (deviating from a simple power law) size-frequency distribution (SFD) for main belt and near-Earth asteroid populations. Neukum proposed a non-power law SFD for the lunar cratering record (Neukum and Ivanov, 1994). This SFD has kept its shape over a period of more than 4 Gyr. The lunar crater SFD is used to estimate the crater-generating family of projectiles from the lunar crater production function since the imagery of the Moon is the most complete and best investigated among the terrestrial planets. Two lunar crater production functions (PF's) were proposed by W. Hartmann (HPF) and G. Neukum (NPF) (Hartmann and Neukum, 2001). The maximum discrepancy between the HPF and NPF is roughly a factor of 3 for crater diameters near D=6 km. For diameters Dage of these surfaces. The major conclusion is that terrestrial planets are most probably bombarded by a single projectile source, i.e. bodies derived from the asteroid belt. The current understanding of Mars's geologic history is based mainly on crater size-frequency measurements carried out on high-resolution Viking imagery and on an impact chronology model for Mars estimated from observations of planet-crossing asteroids and scaled by the lunar production function, which is the best investigated among terrestrial body surfaces. The similarity to crater size-frequency distributions found in the inner solar system suggests a similar origin of the projectiles, probably mainly stemming from the asteroid belt, and the impact rate Mars has had a lunar

  7. Fe embedded in ice: The impacts of sublimation and energetic particle bombardment

    Science.gov (United States)

    Frankland, Victoria L.; Plane, John M. C.

    2015-05-01

    Icy particles containing a variety of Fe compounds are present in the upper atmospheres of planets such as the Earth and Saturn. In order to explore the role of ice sublimation and energetic ion bombardment in releasing Fe species into the gas phase, Fe-dosed ice films were prepared under UHV conditions in the laboratory. Temperature-programmed desorption studies of Fe/H2O films revealed that no Fe atoms or Fe-containing species co-desorbed along with the H2O molecules. This implies that when noctilucent ice cloud particles sublimate in the terrestrial mesosphere, the metallic species embedded in them will coalesce to form residual particles. Sputtering of the Fe-ice films by energetic Ar+ ions was shown to be an efficient mechanism for releasing Fe into the gas phase, with a yield of 0.08 (Ar+ energy=600 eV). Extrapolating with a semi-empirical sputtering model to the conditions of a proton aurora indicates that sputtering by energetic protons (>100 keV) should also be efficient. However, the proton flux in even an intense aurora will be too low for the resulting injection of Fe species into the gas phase to compete with that from meteoric ablation. In contrast, sputtering of the icy particles in the main rings of Saturn by energetic O+ ions may be the source of recently observed Fe+ in the Saturnian magnetosphere. Electron sputtering (9.5 keV) produced no detectable Fe atoms or Fe-containing species. Finally, it was observed that Fe(OH)2 was produced when Fe was dosed onto an ice film at 140 K (but not at 95 K). Electronic structure theory shows that the reaction which forms this hydroxide from adsorbed Fe has a large barrier of about 0.7 eV, from which we conclude that the reaction requires both translationally hot Fe atoms and mobile H2O molecules on the ice surface.

  8. An Archaean heavy bombardment from a destabilized extension of the asteroid belt.

    Science.gov (United States)

    Bottke, William F; Vokrouhlický, David; Minton, David; Nesvorný, David; Morbidelli, Alessandro; Brasser, Ramon; Simonson, Bruce; Levison, Harold F

    2012-05-03

    The barrage of comets and asteroids that produced many young lunar basins (craters over 300 kilometres in diameter) has frequently been called the Late Heavy Bombardment (LHB). Many assume the LHB ended about 3.7 to 3.8 billion years (Gyr) ago with the formation of Orientale basin. Evidence for LHB-sized blasts on Earth, however, extend into the Archaean and early Proterozoic eons, in the form of impact spherule beds: globally distributed ejecta layers created by Chicxulub-sized or larger cratering events4. At least seven spherule beds have been found that formed between 3.23 and 3.47 Gyr ago, four between 2.49 and 2.63 Gyr ago, and one between 1.7 and 2.1 Gyr ago. Here we report that the LHB lasted much longer than previously thought, with most late impactors coming from the E belt, an extended and now largely extinct portion of the asteroid belt between 1.7 and 2.1 astronomical units from Earth. This region was destabilized by late giant planet migration. E-belt survivors now make up the high-inclination Hungaria asteroids. Scaling from the observed Hungaria asteroids, we find that E-belt projectiles made about ten lunar basins between 3.7 and 4.1 Gyr ago. They also produced about 15 terrestrial basins between 2.5 and 3.7 Gyr ago, as well as around 70 and four Chicxulub-sized or larger craters on the Earth and Moon, respectively, between 1.7 and 3.7 Gyr ago. These rates reproduce impact spherule bed and lunar crater constraints.

  9. Cometary impact rates on the Moon and planets during the late heavy bombardment

    Science.gov (United States)

    Rickman, H.; Wiśniowski, T.; Gabryszewski, R.; Wajer, P.; Wójcikowski, K.; Szutowicz, S.; Valsecchi, G. B.; Morbidelli, A.

    2017-02-01

    Context. The Nice model predicts that the trans-planetary planetesimal disk made a large or even dominant contribution to the cratering in the inner solar system during the late heavy bombardment (LHB). In the presence of evidence that lunar craters and mare basins may be mainly of asteroidal origin, there is a dilemma of the missing comets that is not yet resolved. Aims: We aim to revisit the problem of cometary impact rates on the Moon and the terrestrial planets during the LHB with a flexible model, allowing us to study the influences of physical destruction of comets, the mass of the primordial disk, and the distribution of this mass over the entire size range. Methods: We performed a Monte Carlo study of the dynamics of the cometary LHB projectiles and derive the impact rates by calculating individual collision probabilities for a huge sample of projectile orbits. We used Minimum Orbit Intersection Distances (MOIDs) according to a new scheme introduced here. Different calculations were performed using different models for the physical evolution of comet nuclei and for the properties of the primordial, trans-planetary disk. Results: Based on the capture probability of Jupiter Trojans, we find a best fit radius of the largest LHB comet impacting the Moon for a low-mass primordial disk. For this disk mass, the LHB cratering of the Moon, Mercury and Mars were dominated by asteroids. However, some smaller lunar maria were likely preceded by comet impacts. The volatile delivery to the Earth and Mars by LHB comets was much less than their water inventories. Conclusions: There is no excessive cometary cratering, if the LHB was caused by a late planetary instability in the Nice Model. The Earth and Mars obtained their water very early in their histories. The Noachian water flows on Mars cannot be attributed to the arrival of LHB-related H2O or CO2.

  10. Studies on physical characteristics of spallation neutron target

    CERN Document Server

    Wan Jun Sheng; Xia Hai Hong; Zhang Li; Zhang Ying

    2002-01-01

    The spallation target of ADS was studied using DCM/CEM program. The simulation of the lead target of 0.6 m length and 0.2 m in diameter bombarded with 0.1 - 1.6 GeV proton beams was carried out. The neutron spectra, neutron fluence distribution over the lead target, energy deposition and neutron production in the lead target were studied. Some former experimental results can be explained very well with the calculated results. The simulation results agree very well with the former theoretical and experimental results

  11. Post-Hadean transitions in Jack Hills zircon provenance: A signal of the Late Heavy Bombardment?

    Science.gov (United States)

    Bell, Elizabeth A.; Harrison, T. Mark

    2013-02-01

    system (i.e., Late Heavy Bombardment; 3.95-3.85) may have causal significance.

  12. The Impact Rate on Solar System Satellites During the Late Heavy Bombardment

    Science.gov (United States)

    Dones, Henry C. Luke; Levison, H. F.

    2012-10-01

    Nimmo and Korycansky (2012; henceforth NK12) found that if the outer Solar System underwent a Late Heavy Bombardment (LHB) in the Nice model, the mass striking the icy satellites at speeds up to tens of km/s would have vaporized so much ice that moons such as Mimas, Enceladus, and Miranda would have been devolatilized. NK12's possible explanations of this apparent discrepancy with observations include (1) the mass influx was a factor of 10 less than that in the Nice model; (2) the mass distribution of the impactors was top-heavy, so that luck might have saved some of the moons from suffering large, vapor-removing impacts; or (3) the inner moons formed after the LHB. NK12 calculated the mass influx onto the satellites from the lunar impact rate estimated by Gomes et al. (2005) and scaling factors calculated by Zahnle et al. (1998, 2003; also see Barr and Canup 2010). Production of vapor in hypervelocity impacts was calculated from Kraus et al. (2011). We are calculating impact rates onto the giant planets and their moons in the context of the "Nice II" model (Levison et al. 2011). We find that NK12's assumed influx is an overestimate, by an amount we are quantifying. We will discuss implications for the origin of icy satellites. We thank the NASA Lunar Science Institute (http://lunarscience.nasa.gov/) for support. Barr, A.C., Canup, R.M., Nature Geoscience 3, 164-167 (2010). Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A., Nature 435, 466-469 (2005). Kraus, R.G., Senft, L.E., Stewart, S.T., Icarus 214, 724-738 (2011). Levison, H.F., Morbidelli, A., Tsiganis, K., Nesvorný, D., Gomes, R., Astron. J. 142, article id. 152 (2011). Nimmo, F., Korycansky, D.G., Icarus 219, 508-510 (2012). Zahnle, K., Dones, L., Levison, H.F., Icarus 136, 202-222 (1998). Zahnle, K., Schenk, P., Levison, H.F., Dones, L., Icarus 163, 263-289 (2003).

  13. New constraints on the Paleoarchean meteorite bombardment of the Earth - Geochemistry and Re-Os isotope signatures of spherule layers in the BARB5 ICDP drill core from the Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Schulz, Toni; Koeberl, Christian; Luguet, Ambre; van Acken, David; Mohr-Westheide, Tanja; Ozdemir, Seda; Reimold, Wolf Uwe

    2017-08-01

    Archean spherule layers, resulting from impacts by large extraterrestrial objects, to date represent the only remnants of the early meteorite, asteroid, and comet bombardment of the Earth. Only few Archean impact debris layers have been documented, all of them embedded in the 3.23-3.47 billion year old successions of the Barberton Greenstone Belt (BGB) in South Africa and the Pilbara Craton in Western Australia. Some of them might be correlated with each other. Given the scarcity of Archean spherule deposits, four spherule layer intersections from the recently recovered BARB5 drill core from the central Barberton Greenstone Belt, analyzed in this study, provide an opportunity to gain new insight into the early terrestrial impact bombardment. Despite being hydrothermally overprinted, siderophile element abundance signatures of spherule-rich samples from the BARB5 drill core, at least in part, retained a meteoritic fingerprint. The impact hypothesis for the generation of the BARB5 spherule layers is supported by correlations between the abundances of moderately (Cr, Co, Ni) and highly siderophile (Re, Os, Ir, Pt, Ru and Pd) elements, whose peak concentrations and interelement ratios are within the range of those for chondrites. Rhenium-Osmium isotope evidence further support the impact hypothesis. Collectively, this study provides evidence for extraterrestrial admixtures ranging between ∼40 and up to 100% to three of the four analyzed BARB5 spherule layers, and a scenario for their genesis involving (i) impact of a chondritic bolide into a sedimentary target, (ii) varying admixtures of meteoritic components to target materials, (iii) spherule formation via condensation in an impact vapor plume, (iv) transportation of the spherules and sedimentation under submarine conditions, followed by (v) moderate post-impact remobilization of transition metals and highly siderophile elements.

  14. The in situ spatial arrangement of the influenza A virus matrix protein M1 assessed by tritium bombardment

    Science.gov (United States)

    Shishkov, Alexander V.; Goldanskii, Vitalii I.; Baratova, Ludmila A.; Fedorova, Natalia V.; Ksenofontov, Alexander L.; Zhirnov, Oleg P.; Galkin, Alexander V.

    1999-01-01

    Intact influenza A virions were bombarded with thermally activated tritium atoms, and the intramolecular distribution of the label in the matrix protein M1 was analyzed to determine the in situ accessibility of its tryptic fragments. These data were combined with the previously reported x-ray crystal structure of the M1 fragment 2–158 [Sha, B. & Luo, M. (1997) Nat. Struct. Biol. 4, 239–244] and the predicted topology of the C domain (159–252) to propose a model of M1 arrangement in the virus particle. PMID:10393906

  15. Gene transfer by particle bombardment to embryogenic cultures of Picea abies and the production of transgenic plantlets

    Energy Technology Data Exchange (ETDEWEB)

    Clapham, David; Elfstrand, Malin; Sabala, Izabela; Arnold, Sara von [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics; Demel, Petra; Koop, H.U. [Muenchen Univ., Muenchen (Germany). Botanisches Institut

    2000-07-01

    A particle inflow gun enabled efficient production of transgenic plantlets of Picea abies from embryogenic suspension cultures. In transient assays, the Zea ubiquitin promoter was 12-16 times as active as the 35S promoter. For stable transformation, the plasmid pAHC25 contained the bar gene and the gusA gene, both driven by the Zea ubiquitin promoter. Cells were maintained from 1 to 3 h before bombardment on proliferation medium supplemented with 0.25 M myoinositol and, from day 8, supplemented with Basta as selective agent. Embryogenic colonies resistant to Basta appeared from two months after bombardment. Of over 100 independent Basta-resistant sublines tested, 65% expressed the co-transformed reporter gene, even when it was not linked to the selectable marker. Over 80% of the sublines retained their embryogenic potential. Of 11 transformants analyzed, 4 contained transgenes in low copy number (1-3), the rest contained transgenes in up to 15-20 copies. Over 200 Basta-resistant sublines from four cell lines have been established, of which 138 are confirmed as transformed. Plantlets have been regenerated and grown on in pots.

  16. Particle Simulations of a Thermionic RF Gun with Gridded Triode Structure for Reduction of Back-Bombardment

    CERN Document Server

    Kusukame, K; Kii, T; Masuda, K; Nakai, Y; Ohgaki, H; Yamazaki, T; Yoshikawa, K; Zen, H

    2005-01-01

    Thermionic RF guns show advantageous features compared with photocathode ones such as easy operation and much higher repetition rate of micropulses, both of which are suitable for their application to high average power FELs. They however suffer from the back-bombardment effect [1], i.e., in conventional RF guns, electrons are extracted from cathode also in the latter half of accelerating phase and tend to back-stream to hit the cathode, and as a result the macropulse duration is limited down to severalμsec Against this adverse effect in thermionic RF guns, introduction of the triode structure has been proposed [2], where the accelerating phase and amplitude nearby the cathode can be controlled regardless of the phase of the first accelerating cell in the conventional RF gun. Our one-dimensional particle simulation results predict that the back-bombardment power can be reduced by 99 % only with 30-40 kW RF power fed to the grid in the present triode structure with an optimal phase difference from th...

  17. Modeling of metal nanocluster growth on patterned substrates and surface pattern formation under ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Numazawa, Satoshi

    2012-11-01

    are considered as local transition events constrained in potential energy wells over certain local time periods. These processes are represented by Markov chains of multi-dimensional Boolean valued functions in three dimensional lattice space. Consequently, the fluctuating system evolution process is implemented as a Markov chain of equivalence class objects. It is shown that the process can be characterized by the acceptance of metastable local transitions. The method is applied to a problem of Au and Ag cluster growth on a rippled surface. The simulation predicts the existence of a morphology dependent transition time limit from a local metastable to stable state for subsequent cluster growth by accretion. The third topic is the formation of ripple structures on ion bombarded semiconductor surfaces treated in the first topic as the prepatterned substrate of the metallic deposition. This intriguing phenomenon has been known since the 1960's and various theoretical approaches have been explored. These previous models are discussed and a new non-linear model is formulated, based on the local atomic flow and associated density change in the near surface region. Within this framework ripple structures are shown to form without the necessity to invoke surface diffusion or large sputtering as important mechanisms. The model can also be extended to the case where sputtering is important and it is shown that in this case, certain 'magic' angles can occur at which the ripple patterns are most clearly defined. The results including some analytic solutions of the nonlinear equation of motions are in very good agreement with experimental observation.

  18. Extended metastable Al solubility in cubic VAlN by metal-ion bombardment during pulsed magnetron sputtering: film stress vs subplantation

    Science.gov (United States)

    Greczynski, G.; Mráz, S.; Ruess, H.; Hans, M.; Lu, J.; Hultman, L.; Schneider, J. M.

    2017-07-01

    Dynamic ion-recoil mixing of near-film-surface atomic layers is commonly used to increase the metastable solubility limit xmax in otherwise immiscible thin film systems during physical vapor deposition. Recently, Al subplantation achieved by irradiating the film growth surface with Al+ metal-ion flux was shown to result in an unprecedented xmax for VAlN, far above values obtained with gas ion irradiation. However, it is reasonable to assume that ion irradiation necessary for subplantation also leads to a compressive stress σ buildup. In order to separate the effects of Al+ bombardment on σ and xmax, and realize low-stress high-xmax nitride alloys, we grow metastable cubic V1-xAlxN (0.17 ≤ x ≤ 0.74) films using reactive magnetron sputtering under different ion irradiation conditions. Al and V targets are operated in Ar/N2 discharges employing (i) conventional DC (Ar+, N2+), (ii) hybrid High-power pulsed magnetron sputtering (HIPIMS)/DC processing with one type of metal ion present (Al+ or V+/V2+), and (iii) HIPIMS with concurrent Al+ and V+/V2+ fluxes. Comparison to the ab initio calculated Al solubility limit reveals that xmax = 0.55 achieved with V+/V2+ irradiation is entirely accountable for by stress. In contrast, Al+ fluxes provide a substantial increase in xmax to 0.63, which is 12% higher than that expected based on the stress-induced increase in metastable solubility. Correlative stress and atom probe tomography data confirm that the metastable Al solubility enhancement is enabled by Al+ subplantation. The here proposed processing strategy allows for growth of single-phase cubic nitride alloys with significantly increased Al concentrations embodying tremendous promise for substantial improvements in high temperature oxidation resistance and mitigates the risk of stress-induced adhesive or cohesive coating failure.

  19. Development of a double plasma gun device for investigation of effects of vapor shielding on erosion of PFC materials under ELM-like pulsed plasma bombardment

    Science.gov (United States)

    Sakuma, I.; Iwamoto, D.; Kitagawa, Y.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2012-10-01

    It is considered that thermal transient events such as type I edge localized modes (ELMs) could limit the lifetime of plasma-facing components (PFCs) in ITER. We have investigated surface damage of tungsten (W) materials under transient heat and particle loads by using a magnetized coaxial plasma gun (MCPG) device at University of Hyogo. The capacitor bank energy for the plasma discharge is 144 kJ (2.88 mF, 10 kVmax). Surface melting of a W material was clearly observed at the energy density of ˜2 MJ/m2. It is known that surface melting and evaporation during a transient heat load could generate a vapor cloud layer in front of the target material [1]. Then, the subsequent erosion could be reduced by the vapor shielding effect. In this study, we introduce a new experiment using two MCPG devices (MCPG-1, 2) to understand vapor shielding effects of a W surface under ELM-like pulsed plasma bombardment. The capacitor bank energy of MCPG-2 is almost same as that of MCPG-1. The second plasmoid is applied with a variable delay time after the plasmoid produced by MCPG-1. Then, a vapor cloud layer could shield the second plasma load. To verify the vapor shielding effects, surface damage of a W material is investigated by changing the delay time. In the conference, the preliminary experimental results will be shown.[4pt] [1] A. Hassanein et al., J. Nucl. Mater. 390-391, pp. 777-780 (2009).

  20. Język Polaków na Bukowinie Karpackiej

    Directory of Open Access Journals (Sweden)

    Helena Krasowska

    2015-09-01

    Full Text Available The language of Polish people in Carpathian Bukovina The Polish group which was settling in Bukovina since 18th century was various as far as the place of origin is concerned. These are comers from Galicia, Lesser Poland and the region of Czadca in Slovakia. In this article the author presented linguistic situation in particular villages according to the division of Polish community which varies regarding the origin and present place of residence. In the Polish language of Bukovina – according to the research – relatively faint traces of the dialect of Lesser Poland can be found. The speech of comers from lesser Poland weakened due to the prestige of the speech of settlers from Eastern Galicia which developed mainly in conditions of Polish-Ukrainian bilinguism as well as Polish–Ukrainian–Romanian trilinguism or even Polish–Ukrainian–Romanian–German  polylinguism. The author circumstantiated linguistic contacts of the Polish group in Kaczyka, Nowy Sołoniec, Paltynoasa, Plesza, Pojana Mikuli (in Southern Bukovina as well as in Stara Huta, Dolne Piotrowce, Tereblecze (in Northern Bukovina and Czerniowce, Storożyniec and Panka. The most important linguistic features were named in the article. As a result, the Polish community in the Southern Bukovina region can be divided into four groups varying as far as the language and origin are concerned: the dialect of Kaczyka village, dialect of Bukovinian Highlanders; dialect of Ruda village; dialect of Bulaj and Michoweny villages. There is the Polish language, so called all-Bukovinian which is a variation of the Polish language of South-Eastern borderland and the dialect of Bukovinian Highlanders (with different features than the mentioned above.

  1. Sputtering layers of different materials on tungsten surface by light ions of medium energy bombardment

    Science.gov (United States)

    Manukhin, V. V.

    2017-11-01

    There is an analytical formula allows to calculate the sputtering yields of heterogonous solid targets with light ions, based on the model of sputtering layered surfaces with light ions. Of particular interest is the sputtering of layers of different materials with the tungsten surface, which can be a material for the first wall of fusion reactor. The results of the calculations are in good agreement with the data of computer simulation, and show that the sputtering yields layers with a certain thickness, higher than the sputtering yields of homogeneous material layer targets (“mirror effect”).

  2. Study of beryllium redeposition under bombardment by high intensity -low energy- hydrogen ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Gureev, V.M.; Guseva, M.I.; Danelyan, L.S. [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)] [and others

    1998-01-01

    The results of studying the erosion of beryllium under an effect of intense ion fluxes with the energy of 250 eV, at the fluences {approx}10{sup 2}1 cm{sup -2}, at the MAGRAS-stand are given. The operating conditions under which a practically-complete redeposition of the sputtered beryllium upon the target surface were experimentally-realized. A change in the microstructure of a beryllium target under sputtering and redeposition is analyzed. Some technological applications are considered. (author)

  3. From crater functions to partial differential equations: a new approach to ion bombardment induced nonequilibrium pattern formation.

    Science.gov (United States)

    Norris, Scott A; Brenner, Michael P; Aziz, Michael J

    2009-06-03

    We develop a methodology for deriving continuum partial differential equations for the evolution of large-scale surface morphology directly from molecular dynamics simulations of the craters formed from individual ion impacts. Our formalism relies on the separation between the length scale of ion impact and the characteristic scale of pattern formation, and expresses the surface evolution in terms of the moments of the crater function. We demonstrate that the formalism reproduces the classical Bradley-Harper results, as well as ballistic atomic drift, under the appropriate simplifying assumptions. Given an actual set of converged molecular dynamics moments and their derivatives with respect to the incidence angle, our approach can be applied directly to predict the presence and absence of surface morphological instabilities. This analysis represents the first work systematically connecting molecular dynamics simulations of ion bombardment to partial differential equations that govern topographic pattern-forming instabilities.

  4. Tungsten oxide thin film bombarded with a low energy He ion beam: evidence for a reduced erosion and W enrichment

    Science.gov (United States)

    Martin, C.; Hijazi, H.; Addab, Y.; Domenichini, B.; Bannister, M. E.; Meyer, F. W.; Pardanaud, C.; Giacometti, G.; Cabié, M.; Roubin, P.

    2017-12-01

    Nanocrystalline tungsten oxide (WO3) thin films synthesized by thermal oxidation of tungsten substrates were exposed to low energy helium ions (energy: 80 eV; flux: 1.4-1.7 × 1020 m-2 s-1) at room temperature and at 673 K. The structure and morphology changes of the oxide were studied using Raman spectroscopy and electron microscopy. Due to the low ion energy, no erosion is observed at room temperature. In contrast, at 673 K, a color change is observed and a significant erosion is measured (˜70 nm for a fluence of ˜4 × 1021 m-2) due to a synergetic effect between ion bombardment and heating. We show that erosion processes and structural changes strongly depend on the ion fluence and in particular the higher the fluence, the lower the erosion yield, most likely due to oxygen depletion in the oxide near-surface layers.

  5. Nano-scale pattern formation on the surface of HgCdTe produced by ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A.B.; Gudymenko, A.I.; Kladko, V.P.; Korchevyi, A.A.; Savkina, R.K.; Sizov, F.F.; Udovitska, R.S. [V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, Kiev (Ukraine)

    2015-08-15

    Presented in this work are the results concerning formation of nano-scale patterns on the surface of a ternary compound Hg{sub 1-x}Cd{sub x}Te (x ∝ 0.223). Modification of this ternary chalcogenide semiconductor compound was performed using the method of oblique-incidence ion bombardment with silver ions, which was followed by low-temperature treatment. The energy and dose of implanted ions were 140 keV and 4.8 x 10{sup 13} cm{sup -2}, respectively. Atomic force microscopy methods were used for the surface topography characterization. The structural properties of MCT-based structure was analyzed using double and triple crystal X-ray diffraction to monitor the disorder and strain of the implanted region as a function of processing conditions. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. The 30Si (ρ, γ) 31P reaction for bombarding energies between 1.00 and 1.53 MeV

    NARCIS (Netherlands)

    Rinsvelt, H. van; Smith, Philip B.

    Eighteen resonances have been identified as belonging to the 30Si(, γ)31P reaction for proton bombarding energies between 1.00 and 1.53 MeV. The gamma-ray yield of the corresponding excited states of 31P has been measured, and the principle features of the decay have been determined. Double and/or

  7. Selective atomic-level etching using two heating procedures, infrared irradiation and ion bombardment, for next-generation semiconductor device manufacturing

    Science.gov (United States)

    Shinoda, K.; Miyoshi, N.; Kobayashi, H.; Miura, M.; Kurihara, M.; Maeda, K.; Negishi, N.; Sonoda, Y.; Tanaka, M.; Yasui, N.; Izawa, M.; Ishii, Y.; Okuma, K.; Saldana, T.; Manos, J.; Ishikawa, K.; Hori, M.

    2017-05-01

    The demand for precisely controlled etching is increasing as semiconductor device geometries continue to shrink. To fulfill this demand, cyclic atomic level/layer etching will become one of the key technologies in semiconductor device manufacturing at nanometer dimensions. This review describes recent trends in semiconductor devices and some of the latest results on cyclic atomic-level etching. In particular, it focuses on two types of cyclic etching that use different heating procedures: infrared irradiation for isotropic etching and Ar+ ion bombardment for anisotropic etching. It describes how an inductively-coupled-plasma down-flow etching apparatus with infrared lamps can be used for isotropic cyclic etching. The isotropic cyclic etching of SiN involves the formation and thermal desorption of ammonium hexafluorosilicate-based surface modified layers. This method features high selectivity with respect to SiO2, atomic-level control of the amount of SiN etching, and isotropic etched features. On the other hand, the anisotropic cyclic etching with Ar+ ion bombardment uses a microwave electron-cyclotron-resonance plasma etching apparatus. The anisotropic process for poly Si is composed of cyclic repetitions of chlorine adsorption and Ar+ ion bombardment. The anisotropic process for SiN is composed of cyclic repetitions involving an adsorption step using hydrofluorocarbon chemistry and a desorption step using Ar+ ion bombardment. Potential applications of these isotropic/anisotropic cyclic etching processes are described.

  8. The influence of energetic bombardment on the structure formation of sputtered zinc oxide films. Development of an atomistic growth model and its application to tailor thin film properties

    Energy Technology Data Exchange (ETDEWEB)

    Koehl, Dominik

    2011-02-17

    The focus of this work is the investigation of the growth of zinc oxide (ZnO) thin films. It is demonstrated that with a modified, ion beam assisted sputtering (IBAS) process, zinc oxide films can be deposited which exhibit a markedly improved crystalline order. Furthermore, it is demonstrated that intense energetic oxygen ion bombardment can be utilized to change film texture from the typical (002)-self-texture to an a-axis texture where the (002)-planes are perpendicular to the substrate surface. An understanding of the underlying mechanisms is developed which also facilitates a more detailed understanding of the action of ion bombardment during zinc oxide film growth. It is shown that zinc oxide films are susceptible to the influence of ion bombardment particularly in the nucleation regime of growth and that this finding is generally true for all observed structural changes induced by ion bombardment with various species, energies and flux densities. It is demonstrated not only that the initial growth stage plays an important role in the formation of a preferred growth orientation but also that the action of texture forming mechanisms in subsequent growth stages is comparatively weak. (orig.)

  9. "I Feel like I'm Being Hit from All Directions": Enduring the Bombardment as a Mature-Age Learner Returning to Formal Learning

    Science.gov (United States)

    Willans, Julie; Seary, Karen

    2011-01-01

    The mature-age learner's re-engagement with a formal learning environment may be somewhat akin to the novice Paintball player who, unless well positioned and attuned to the rules of the combative game, is bombarded and worn down by constant "hits". For the mature-age learner, such "hits" may come in the form of tensions…

  10. Determination of the most efficient target tissue and helium pressure for biolistic transformation of oil palm (Elaeis guineensis Jacq.

    Directory of Open Access Journals (Sweden)

    Amornrat Phongdara

    2008-03-01

    Full Text Available An efficient genetic transformation system for oil palm using particle bombardment was established. The transformation was performed using the pCAMBIA 1302 DNA which contains the green fluorescent protein (mgfp5 reporter gene and the selectable marker hygromycin phosphotransferase (hph gene. Oil palm explants were bombarded under the following conditions: rupture disk to macrocarrier distance, 11 mm; macrocarrier to target tissue, 90 mm and using 1 μm gold particles as microcarrier. Four different pressures of helium were tested with three types of target tissues (mature embryo, embryogenic callus and young seedlings. From the transformation efficiency, calli were much more efficiently transformed in the biolistic process compared with mature embryos and seedlings. A 100% transformation efficiency for DNA delivery into callus oil palm explants was obtained at 850 psi helium pressures, for embryos a maximum 81.8% efficiency required 850 psi and for seedlings a maximum 75.9% efficiency required 1,550 psi. Using a confocal laser scanning microscope, and appropriate filters to block out the red fluorescence of chlorophyll, expression of the GFP gene was observed in all three bombarded explant types by a bright-green fluorescence. The mgfp5 gene was still present more than 8 months after bombardment, hence it indicated the stability of transgene in those transformants.

  11. Influence of substrate pre-treatments by Xe{sup +} ion bombardment and plasma nitriding on the behavior of TiN coatings deposited by plasma reactive sputtering on 100Cr6 steel

    Energy Technology Data Exchange (ETDEWEB)

    Vales, S., E-mail: sandra.vales@usp.br [Universidade de São Paulo (USP), Escola de Engenharia de São Carlos, Av. Trabalhador São Carlense 400, São Carlos, SP CEP 13566-590 (Brazil); Brito, P., E-mail: ppbrito@gmail.com [Pontifícia Universidade Católica de Minas Gerais (PUC-MG), Av. Dom José Gaspar 500, 30535-901 Belo Horizonte, MG (Brazil); Pineda, F.A.G., E-mail: pipe8219@gmail.com [Universidade de São Paulo (USP), Escola de Engenharia de São Carlos, Av. Trabalhador São Carlense 400, São Carlos, SP CEP 13566-590 (Brazil); Ochoa, E.A., E-mail: abigail_ochoa@hotmail.com [Universidade Estadual de Campinas (UNICAMP), Campus Universitário Zeferino Vaz, Barão Geraldo, Campinas, SP CEP 13083-970 (Brazil); Droppa, R., E-mail: roosevelt.droppa@ufabc.edu.br [Universidade Federal do ABC (UFABC), Av. dos Estados, 5001, Santo André, SP CEP 09210-580 (Brazil); Garcia, J., E-mail: jose.garcia@sandvik.com [Sandvik Coromant R& D, Lerkrogsvägen 19, SE-12680, Stockholm (Sweden); Morales, M., E-mail: monieriz@gmail.com [Universidade Estadual de Campinas (UNICAMP), Campus Universitário Zeferino Vaz, Barão Geraldo, Campinas, SP CEP 13083-970 (Brazil); Alvarez, F., E-mail: alvarez@ifi.unicamp.br [Universidade Estadual de Campinas (UNICAMP), Campus Universitário Zeferino Vaz, Barão Geraldo, Campinas, SP CEP 13083-970 (Brazil); and others

    2016-07-01

    In this paper the influence of pre-treating a 100Cr6 steel surface by Xe{sup +} ion bombardment and plasma nitriding at low temperature (380 °C) on the roughness, wear resistance and residual stresses of thin TiN coatings deposited by reactive IBAD was investigated. The Xe{sup +} ion bombardment was carried out using a 1.0 keV kinetic energy by a broad ion beam assistance deposition (IBAD, Kaufman cell). The results showed that in the studied experimental conditions the ion bombardment intensifies nitrogen diffusion by creating lattice imperfections, stress, and increasing roughness. In case of the combined pre-treatment with Xe{sup +} ion bombardment and subsequent plasma nitriding, the samples evolved relatively high average roughness and the wear volume increased in comparison to the substrates exposed to only nitriding or ion bombardment. - Highlights: • Effect of Xe ion bombardment and plasma nitriding on TiN coatings was investigated. • Xe ion bombardment with 1.0 KeV increases nitrogen retention in plasma nitriding. • 1.0 KeV ion impact energy causes sputtering, thus increasing surface roughness. • TiN coating wear is minimum after plasma nitriding due to lowest roughness.

  12. The production of ⁸²Sr using larger format RbCl targets.

    Science.gov (United States)

    Meulen, N P van der; Walt, T N van der; Steyn, G F; Raubenheimer, H G

    2013-02-01

    The production of (82)Sr at iThemba LABS is performed by the proton bombardment of a RbCl target using the facility's Vertical-Beam Target Station (VBTS). (82)Sr is separated from the target material using a method based on target dissolution, using dilute ammonium chloride solution, and the use of chromatographic methods on Purolite S950 ion exchange resin. After performing a further purification step using AG MP-50 macroporous cation exchange resin, the result is a product with a high radionuclidic purity and negligible Rb and Fe impurity content. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. A cryostat to hold frozen-spin polarized HD targets in CLAS: HDice-II

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, M.M., E-mail: mlowry@jlab.org [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Bass, C.D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); D' Angelo, A. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Universita' di Roma ‘Tor Vergata’, and INFN Sezione di Roma ‘Tor Vergata’, Via della Ricerca Scientifica, 1, I-00133 Roma (Italy); Deur, A.; Dezern, G. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Hanretty, C. [University of Virginia, 1400 University Avenue, Charlottesville, VA 22903 (United States); Ho, D. [Carnegie-Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Kageya, T.; Kashy, D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Khandaker, M. [Norfolk State University, 700 Park Avenue, Norfolk, VA 23504 (United States); Laine, V. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Université Blaise Pascal, 34 Avenue Carnot, 63000 Clermont-Ferrand (France); O' Connell, T. [University of Connecticut, 115 N Eagleville Road, Storrs-Mansfield, CT 06269 (United States); Pastor, O. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Peng, P. [University of Virginia, 1400 University Avenue, Charlottesville, VA 22903 (United States); Sandorfi, A.M. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Sokhan, D. [Institut de Physique Nucleaire, Bat 100 – M053, Orsay 91406 (France); and others

    2016-04-11

    The design, fabrication, operation, and performance of a {sup 3/4}He dilution refrigerator and superconducting magnet system for holding a frozen-spin polarized hydrogen deuteride target in the Jefferson Laboratory CLAS detector during photon beam running is reported. The device operates both vertically (for target loading) and horizontally (for target bombardment). The device proves capable of maintaining a base temperature of 50 mK and a holding field of 1 T for extended periods. These characteristics enabled multi-month polarization lifetimes for frozen spin HD targets having proton polarization of up to 50% and deuteron up to 27%.

  14. In-situ study of emerging metallicity and memory effect on ion-beam bombarded strontium titanate surface

    Science.gov (United States)

    Gross, Heiko

    In this work we present an investigation of the occurrence of conductivity on the surface of SrTiO3 due to argon ion bombardment. We created a model to describe this process and found that the temperature during the ion milling is a crucial factor for the conductivity. Depending on the temperatures we found surface carrier densities ranging from nS = 1:5 x 1018 to 2:6 x 1020 cm -3 by just analyzing the conductivity behavior. Clustering of vacancies goes along with temperature and affects the conductivity significantly. Furthermore we found that ion milling is a gentle way to create vacancies because the clustering rate is small compared to annealing samples in high vacuum. The amount of clusters at room temperature was measured to be around 3-4 times higher than at -140°C. We found that samples with a conducting surface change their resistance over time at room-temperature due to the ongoing process of oxygen vacancy clustering. This effect may be suppressed by decreasing the temperature. The bistable switching behavior in oxygen deficient SrTiO3 is shown without any additional doping. The vacancy migration is the major mechanism behind this memory effect. Comparing this behavior with annealed samples in high vacuum shows that the therein present amount of vacancy clusters must be much larger and has a negative effect on the bistable switching behavior.

  15. Metabolism of cycloate in radish leaf: metabolite identification by packed capillary flow fast atom bombardment tandem mass spectrometry.

    Science.gov (United States)

    Onisko, B C; Barnes, J P; Staub, R E; Walker, F H; Kerlinger, N

    1994-10-01

    The metabolism of cycloate, a thiocarbamate herbicide, was investigated in mature radish leaf. Twelve new metabolites were identified by liquid chromatographic/mass spectrometric analysis using fast atom bombardment and packed capillary liquid chromatography columns. Full-scan and tandem mass spectrometric methods were employed. Application of the on-column focusing technique resulted in identifications with injections of as little as 15 ng of metabolite (20 ppb in radish). This injection technique allows the practical use of packed capillary liquid chromatography/mass spectrometry in sample-limited applications. Cycloate is oxidized to several ring-hydroxylated isomers that are subsequently glucosylated and esterified with malonic acid. Cycloate is also conjugated with glutathione. Metabolic hydrolysis of the glutathione conjugate formed a cysteine conjugate that is further metabolized by amidation with either malonic or acetic acid. Transamination of the cysteine conjugate gave a thiolactic acid derivative. Metabolites were also identified that were the result of both ring-hydroxylation and conjugation with glutathione. One of these, an N-acetylcysteine conjugate, is the first report of a mercapturic acid in plants. The structures of two of the new metabolites were confirmed by chemical synthesis.

  16. Computer simulations of material ejection during C60 and Arm bombardment of octane and β-carotene

    Science.gov (United States)

    Palka, G.; Kanski, M.; Maciazek, D.; Garrison, B. J.; Postawa, Z.

    2015-06-01

    Molecular dynamics (MD) computer simulations are used to investigate material ejection and fragment formation during keV C60 and Arm (m = 60, 101, 205, 366, 872 and 2953) bombardment of organic solids composed from octane and β-carotene molecules at 0° and 45° impact angle. Both systems are found to sputter efficiently. For the octane system, material removal occurs predominantly by ejection of intact molecules, while fragment emission is a significant ejection channel for β-carotene. A difference in the molecular dimensions is proposed to explain this observation. It has been shown that the dependence of the sputtering yield Y on the primary kinetic energy E and the cluster size n can be expressed in a simplified form if represented in reduced units. A linear and nonlinear dependence of the Y/n on the E/n are identified and the position of the transition point from the linear to nonlinear regions depends on the size of the cluster projectile. The impact angle has a minor influence on the shape of the simplified representation.

  17. Effect of ion bombardment and substrate orientation on structure and properties of titanium nitride films deposited by unbalanced magnetron sputtering

    CERN Document Server

    Guruvenket, S

    2002-01-01

    The effect of substrate orientation and ion bombardment during the growth on the structure and properties of TiN films deposited by reactive unbalanced magnetron sputtering has been reported. Films deposited at a nitrogen partial pressure of 5x10 sup - sup 5 mbar and a current density of 2.50 mA cm-2 were golden yellow in color, characteristic of stoichiometric TiN. The effect of Si(100) and Si(111) substrates on the TiN film along with the substrate bias has been investigated. With an increase in the substrate bias on Si(111) substrate, TiN(111) is the most preferred orientation. On a Si(100) substrate with an increase in the substrate bias, TiN(220) orientation has been observed. The influence of the substrate on the growth of TiN films has been explained in terms of surface energy. The variation of grain size, resistivity, and the internal stress of TiN films as the function of substrate bias have also been investigated.

  18. Intensity distributions of reflected surface channeling protons scattered on surfaces of electron-bombarded alkali halide crystals

    Science.gov (United States)

    Fukazawa, Y.; Kihara, K.; Iwamoto, K.; Susuki, Y.

    2013-11-01

    We have examined the surface-channeling of 550 keV protons on electron-bombarded KBr(0 0 1) surfaces at grazing incidence. On the surface, electron-stimulated desorption (ESD) resulting from the irradiation of 5 keV electrons changes the surface morphology. In order to investigate the change of the surface morphology, the luminous intensity distributions observed on a fluorescent screen (scattering patterns) of the reflected protons under the surface-channeling conditions are measured. Normalized specular intensity of the protons oscillates, and the results of computer simulations show that the period of the intensity oscillation agrees with the period of layer-by-layer desorption. The measured period of the oscillation is comparable to the simulated one, i.e., the period of the desorption, however, the measured amplitude of the oscillation is weak. This shows that the layer-by-layer desorption of the experimental surface is observed but is not as remarkable as that of the perfect surface introduced in the simulation.

  19. Intensity distributions of reflected surface channeling protons scattered on surfaces of electron-bombarded alkali halide crystals

    Energy Technology Data Exchange (ETDEWEB)

    Fukazawa, Y., E-mail: yukofu@cc.osaka-kyoiku.ac.jp; Kihara, K.; Iwamoto, K.; Susuki, Y.

    2013-11-15

    We have examined the surface-channeling of 550 keV protons on electron-bombarded KBr(0 0 1) surfaces at grazing incidence. On the surface, electron-stimulated desorption (ESD) resulting from the irradiation of 5 keV electrons changes the surface morphology. In order to investigate the change of the surface morphology, the luminous intensity distributions observed on a fluorescent screen (scattering patterns) of the reflected protons under the surface-channeling conditions are measured. Normalized specular intensity of the protons oscillates, and the results of computer simulations show that the period of the intensity oscillation agrees with the period of layer-by-layer desorption. The measured period of the oscillation is comparable to the simulated one, i.e., the period of the desorption, however, the measured amplitude of the oscillation is weak. This shows that the layer-by-layer desorption of the experimental surface is observed but is not as remarkable as that of the perfect surface introduced in the simulation.

  20. Convenient recycling and reuse of bombarded [¹⁸O]H₂O for the production and the application of [¹⁸F]F⁻.

    Science.gov (United States)

    Rötering, Sven; Franke, Karsten; Zessin, Jörg; Brust, Peter; Füchtner, Frank; Fischer, Steffen; Steinbach, Jörg

    2015-07-01

    The limited availability and the increasing demands of [(18)O]H2O force the reuse of bombarded [(18)O]H2O for the production of [(18)F]F(-) at least for the purposes of research. Therefore, inorganic and organic contaminants have to be removed from the [(18)O]H2O after bombardment. We present a simple, effective, easy-handling and reliable method of [(18)O]H2O purification including oxidation and distillation. The obtained recycled [(18)O]H2O had comparable quality to commercially distributed [(18)O]water. This was confirmed by a detailed comparison of produced radionuclides and their activities and the application of [(18)F]F(-) for the automated synthesis of [(18)F]fluspidine. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Energy spectra of sputtered positive ions under Cs{sup +} bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Gnaser, Hubert, E-mail: gnaser@rhrk.uni-kl.d [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, D-67663 Kaiserslautern (Germany); Institute for Surface and Thin-Film Analysis IFOS, Trippstadter Str. 120, D-67663 Kaiserslautern (Germany)

    2011-05-01

    The emission-energy spectra of atomic and molecular secondary ions sputtered from various metals and semiconductors (Al, Cu, In, Si, InP, and InSb) under 5.5-keV Cs{sup +} irradiation were investigated. The emitted ions were detected in a high-sensitivity double-focusing secondary-ion mass spectrometer. Specifically, the energy distributions of Cs{sup +}, Cs{sub 2}{sup +}, MCs{sup +}, and M{sup +} ions (where M designates one of the target elements) were recorded for emission energies E {<=} 125 eV. All ion species exhibit a peak at low energy (E < 5 eV), but differ significantly in the respective fall-off to high emission energies. The influence of the oxygen partial pressure in the vicinity of the sputtered surface on the energy spectra was examined for Cs{sup +} ions emitted from Si. With an increase of the ratio r of the O{sub 2} flux to the Cs{sup +} flux, the spectra shift to higher emission-energy values, with the total shift amounting to {approx}0.45 eV at a value of r {approx} 3.3. Concurrently, the intensity of Cs{sup +} increases by {approx}30%. The measured emission distributions of Cs{sup +} ions from different samples were compared with the predictions of the electron-tunneling model of secondary-ion formation. It is found that the experimental spectra can be reproduced quite well when employing specific sets of parameters in that theoretical concept. The possible limitations of such a comparison are discussed.

  2. The unexpected formation of Au δ+ -Si δ- by the resonance neutralization of Ar + during the low energy bombardment of Au nanoparticles on c-Si

    Science.gov (United States)

    Yang, De-Quan; Sacher, Edward

    2009-05-01

    Nanoscale Au layers, with irregular porosities, have been formed by the low energy Ar + bombardment of Au nanoparticles that were sputter-deposited onto native oxide-covered Si surfaces. High-resolution field emission scanning electron microcopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS) have been used to characterize the formation and evolution of the nanoporous layer. Under Ar + bombardment, the Au nanoparticles that were initially deposited were observed to flatten and spread across the native oxide surface, without diffusing, finally coalescing at their edges to form a nanoporous film having irregular pore dimensions. XPS showed that this evolution was accompanied by the loss of Au as a result of sputtering. The formation of such porous films necessitates strong interfacial bonding to avoid the lateral diffusion of the Au nanoparticles, and their ultimate coalescence into larger nanoparticles. We demonstrated that Ar + beam bombardment invariably caused the formation of Au δ+ -Si δ- bonding, rather than the expected Au δ- -Si δ+ bonding, and we explain this to be due to the resonance neutralization of the Ar + beam on impacting the Au layer. We also reveal that the presumed formation of AuSi x is not quantifiable by XPS, due to the superposition of the chemical shift of the Au nanoparticles with that of the quantum size effect, during Au loss on sputtering.

  3. The SPES High Power ISOL production target

    Science.gov (United States)

    Andrighetto, A.; Corradetti, S.; Ballan, M.; Borgna, F.; Manzolaro, M.; Scarpa, D.; Monetti, A.; Rossignoli, M.; Silingardi, R.; Mozzi, A.; Vivian, G.; Boratto, E.; De Ruvo, L.; Sattin, N.; Meneghetti, G.; Oboe, R.; Guerzoni, M.; Margotti, A.; Ferrari, M.; Zenoni, A.; Prete, G.

    2016-11-01

    SPES (Selective Production of Exotic Species) is a facility under construction at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro), aimed to produce intense neutron-rich radioactive ion beams (RIBs). These will be obtained using the ISOL (Isotope Separation On-Line) method, bombarding a uranium carbide target with a proton beam of 40MeV energy and currents up to 200μA. The target configuration was designed to obtain a high number of fissions, up to 1013 per second, low power deposition and fast release of the produced isotopes. The exotic isotopes generated in the target are ionized, mass separated and re-accelerated by the ALPI superconducting LINAC at energies of 10AMeV and higher, for masses in the region of A = 130 amu , with an expected rate on the secondary target up to 109 particles per second. In this work, recent results on the R&D activities regarding the SPES RIB production target-ion source system are reported.

  4. Electromagnetic Dissociation of Target Nuclei by $^{208}$Pb Projectiles

    CERN Multimedia

    Petridis, A; Wohn, F K

    2002-01-01

    % NA53 \\\\ \\\\ The purpose of this experiment is to study the process of electromagnetic dissociation (ED) that occurs at impact parameters large enough so that there is no nuclear interaction. In these cases strong electromagnetic fields are produced for a short time at the nucleus. For large charges and ultrarelativistic energies, the intense electromagnetic pulse produces cross-sections much larger than the total hadronic cross-section. These effects place significant constraints on the storage times of the heavy ion beams planned for RHIC and LHC.\\\\ \\\\In this experiment we measure the cross-sections for the one- and two-neutron removal processes resulting from the interaction of 160 and 40~GeV/nucleon Pb beams on Au and Co targets. Thin Au targets were bombarded in the beam line of the NA50 experiment. Gamma rays from the residual nuclides produced in the bombardment were measured to determine the saturation activities of $^{196}$Au and $^{195}$Au resulting from ED of the Au target. This along with cross-se...

  5. SPITZER EVIDENCE FOR A LATE-HEAVY BOMBARDMENT AND THE FORMATION OF UREILITES IN {eta} CORVI At {approx}1 Gyr

    Energy Technology Data Exchange (ETDEWEB)

    Lisse, C. M. [JHU-APL, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Wyatt, M. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Chen, C. H. [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Morlok, A. [Department of Earth and Planetary Sciences, The Open University, Milton-Keynes (United Kingdom); Watson, D. M.; Manoj, P.; Sheehan, P. [Department of Physics and Astronomy, University of Rochester, Rochester, NY (United States); Currie, T. M. [NASA-GSFC, Code 667, Greenbelt, MD 20771 (United States); Thebault, P. [Observatoire de Paris, F-92195 Meudon Principal Cedex (France); Sitko, M. L., E-mail: carey.lisse@jhuapl.edu, E-mail: wyatt@ast.cam.ac.uk, E-mail: cchen@stsci.edu, E-mail: a.morlok@open.ac.uk, E-mail: dmw@pas.rochester.edu, E-mail: manoj@pas.rochester.edu, E-mail: psheeha2@mail.rochester.edu, E-mail: thayne.m.currie@nasa.gov, E-mail: philippe.thebault@obspm.fr, E-mail: sitko@spacescience.org [Space Science Institute, 475 Walnut Street, Suite 205, Boulder, CO 80301 (United States)

    2012-03-10

    We have analyzed Spitzer and NASA/IRTF 2-35 {mu}m spectra of the warm, {approx}350 K circumstellar dust around the nearby MS star {eta} Corvi (F2V, 1.4 {+-} 0.3 Gyr). The spectra show clear evidence for warm, water- and carbon-rich dust at {approx}3 AU from the central star, in the system's terrestrial habitability zone. Spectral features due to ultra-primitive cometary material were found, in addition to features due to impact produced silica and high-temperature carbonaceous phases. At least 9 Multiplication-Sign 10{sup 18} kg of 0.1-100 {mu}m warm dust is present in a collisional equilibrium distribution with dn/da {approx} a{sup -3.5}, the equivalent of a 130 km radius Kuiper Belt object (KBO) of 1.0 g cm{sup 3} density and similar to recent estimates of the mass delivered to the Earth at 0.6-0.8 Gyr during the late-heavy bombardment. We conclude that the parent body was a Kuiper Belt body or bodies which captured a large amount of early primitive material in the first megayears of the system's lifetime and preserved it in deep freeze at {approx}150 AU. At {approx}1.4 Gyr they were prompted by dynamical stirring of their parent Kuiper Belt into spiraling into the inner system, eventually colliding at 5-10 km s{sup -1} with a rocky planetary body of mass {<=}M{sub Earth} at {approx}3 AU, delivering large amounts of water (>0.1% of M{sub Earth'sOceans}) and carbon-rich material. The Spitzer spectrum also closely matches spectra reported for the Ureilite meteorites of the Sudan Almahata Sitta fall in 2008, suggesting that one of the Ureilite parent bodies was a KBO.

  6. STABILITY OF EXTRATERRESTRIAL GLYCINE UNDER ENERGETIC PARTICLE RADIATION ESTIMATED FROM 2 keV ELECTRON BOMBARDMENT EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Maté, B.; Tanarro, I.; Escribano, R.; Moreno, M. A.; Herrero, V. J. [Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, E-28006 Madrid (Spain)

    2015-06-20

    The destruction of solid glycine under irradiation with 2 keV electrons has been investigated by means of IR spectroscopy. Destruction cross sections, radiolysis yields, and half-life doses were determined for samples at 20, 40, 90, and 300 K. The thickness of the irradiated samples was kept below the estimated penetration depth of the electrons. No significant differences were obtained in the experiments below 90 K, but the destruction cross section at 300 K was larger by a factor of 2. The radiolysis yields and half-life doses are in good accordance with recent MeV proton experiments, which confirms that electrons in the keV range can be used to simulate the effects of cosmic rays if the whole sample is effectively irradiated. In the low temperature experiments, electron irradiation leads to the formation of residues. IR absorptions of these residues are assigned to the presence CO{sub 2}, CO, OCN{sup −}, and CN{sup −} and possibly to amide bands I to III. The protection of glycine by water ice is also studied. A water ice film of ∼150 nm is found to provide efficient shielding against the bombardment of 2 keV electrons. The results of this study show also that current Monte Carlo predictions provide a good global description of electron penetration depths. The lifetimes estimated in this work for various environments ranging from the diffuse interstellar medium to the inner solar system, show that the survival of hypothetical primeval glycine from the solar nebula in present solar system bodies is not very likely.

  7. Target Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — [Part of the ATLAS user facility.] The Physics Division operates a target development laboratory that produces targets and foils of various thickness and substrates,...

  8. Corrigendum to "Geant4 validation of neutron production on thick targets bombarded with 120 GeV protons" [Nucl. Instr. Meth. B 358 (2015) 245-250

    Science.gov (United States)

    Sabra, Mohammad S.

    2016-09-01

    In the paper by Mohammad S. Sabra, due to a mixup, wrong calculations for NEPR ratios, normalized to 20 cm-thick copper, for 40 cm and 60 cm-thick copper at 30° for QGSP-BIC, QGSP-BERT, QGSP-INCLXX, and SHIELDING were published in Table 2. The correct values are listed in the revised Table 2 as below.

  9. New insights from old spherules: Os-W isotope and HSE evidence for Paleoarchean meteorite bombardment of the Earth

    Science.gov (United States)

    Schulz, T.; Luguet, A. A.; Koeberl, C.

    2014-12-01

    Introduction: Although still debated, spherule beds in the Barberton Mountain Land (~3.4 Ga) are suspected to represent remnants of impact-generated and ballistically emplaced silicate melt droplets [e.g. 1]. Such deposits provide the only window into the late stages of the heavy meteorite bombardment on Earth as their source craters have long since been obliterated. In order to identify a possible meteoritic component and, if successful, to discuss potential projectile materials, we are performing a detailed Os-W isotope as well as HSE abundance study on spherule layers from the recently drilled ICDP BARB5 core (grid location 25°30`50.76``S, 31°33`10.08``E). Samples and Methods: Samples were taken from a spherule-containing meta-sedimentary core section discovered between 510 and 512 m depth. About 100 mg of homogenized sample powders were spiked with a mixed 190Os, 185Re, 191Ir and 194Pt tracer and treated in a high pressure asher using inverse aqua regia, followed by conventional extraction schemes for Os and the other HSEs [4]. Chemical and Os isotope measurements (via N-TIMS) were performed in Vienna, whereas HSE measurements were undertaken via ICP MS in Bonn. Results and Discussion: Our preliminary Os isotope data reveal a trend between samples exhibiting high spherule to matrix ratios (187Os/188Os ~0.106 and Os ~0.4 ppm) and samples with lower ones (187Os/188Os up to ~0.304 and Os ~0.008 ppm). Notably, the most unradiogenic samples exhibit carbonaceous-chondrite-like initial 187Os/188Os and HSE ratios, whereas all other samples are clear non-chondritic. These findings support an extraterrestrial contribution in the spherules and can be interpreted compared to conclusions drawn from a Cr isotope study performed on similar samples [3], possibly representing a different impact event and favouring a chondritic projectile. However, further considerations based on precise Os/W ratio determinations and high-precision 182W isotope data, will be presented at the

  10. Distributions of neutron yields and doses around a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, D., E-mail: satoh.daiki@jaea.go.jp [Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kajimoto, T. [Hiroshima University, Kagamiyama, Higashi-Hiroshima-shi, Hiroshima 739-8527 (Japan); Shigyo, N.; Itashiki, Y.; Imabayashi, Y. [Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Koba, Y.; Matsufuji, N. [National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Sanami, T. [High Energy Accelerator Research Organization, Oho-cho, Tsukuba-shi, Ibaraki 305-0801 (Japan); Nakao, N. [Shimizu Corporation, Etchujima, Koto-ku, Tokyo 135-8530 (Japan); Uozumi, Y. [Kyushu University, Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

    2016-11-15

    Double-differential neutron yields from a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions were measured at emission angles of 15°, 30°, 45°, 60°, 75°, and 90°, and angular distributions of neutron yields and doses around the phantom were obtained. The experimental data were compared with results of the Monte-Carlo simulation code PHITS. The PHITS results showed good agreement with the measured data. On the basis of the PHITS simulation, we estimated the angular distributions of neutron yields and doses from 0° to 180° including thermal neutrons.

  11. Measurements of neutron spectrum from stopping-length target irradiated by several tens-MeV/u particles

    Energy Technology Data Exchange (ETDEWEB)

    Meigo, Shin-ichiro; Takada, Hiroshi; Nakashima, Hiroshi; Sasa, Toshinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Tanaka, Susumu; Shin, Kazuo; Ono, Shinji

    1997-03-01

    Using a Time-of-Flight technique, we have measured neutron spectra from stopping-length targets bombarded with 68-MeV protons and 100-MeV {alpha}-particles. The measured spectra were used to validate the results calculated by the Quantum Molecular Dynamics (QMD) plus Statistical Decay Model (SDM). The results of QMD plus SDM code agreed fairly well with the experimental data for the light target. On the other hand, the QMD plus SDM gives a larger value than the experimental for the heavy target. (author)

  12. The Formation of Jupiter, the Jovian Early Bombardment and the Delivery of Water to the Asteroid Belt: The Case of (4 Vesta

    Directory of Open Access Journals (Sweden)

    Diego Turrini

    2014-01-01

    Full Text Available The asteroid (4 Vesta, parent body of the Howardite-Eucrite-Diogenite meteorites, is one of the first bodies that formed, mostly from volatile-depleted material, in the Solar System. The Dawn mission recently provided evidence that hydrated material was delivered to Vesta, possibly in a continuous way, over the last 4 Ga, while the study of the eucritic meteorites revealed a few samples that crystallized in presence of water and volatile elements. The formation of Jupiter and probably its migration occurred in the period when eucrites crystallized, and triggered a phase of bombardment that caused icy planetesimals to cross the asteroid belt. In this work, we study the flux of icy planetesimals on Vesta during the Jovian Early Bombardment and, using hydrodynamic simulations, the outcome of their collisions with the asteroid. We explore how the migration of the giant planet would affect the delivery of water and volatile materials to the asteroid and we discuss our results in the context of the geophysical and collisional evolution of Vesta. In particular, we argue that the observational data are best reproduced if the bulk of the impactors was represented by 1–2 km wide planetesimals and if Jupiter underwent a limited (a fraction of au displacement.

  13. The formation of jupiter, the jovian early bombardment and the delivery of water to the asteroid belt: the case of (4) vesta.

    Science.gov (United States)

    Turrini, Diego; Svetsov, Vladimir

    2014-01-28

    The asteroid (4) Vesta, parent body of the Howardite-Eucrite-Diogenite meteorites, is one of the first bodies that formed, mostly from volatile-depleted material, in the Solar System. The Dawn mission recently provided evidence that hydrated material was delivered to Vesta, possibly in a continuous way, over the last 4 Ga, while the study of the eucritic meteorites revealed a few samples that crystallized in presence of water and volatile elements. The formation of Jupiter and probably its migration occurred in the period when eucrites crystallized, and triggered a phase of bombardment that caused icy planetesimals to cross the asteroid belt. In this work, we study the flux of icy planetesimals on Vesta during the Jovian Early Bombardment and, using hydrodynamic simulations, the outcome of their collisions with the asteroid. We explore how the migration of the giant planet would affect the delivery of water and volatile materials to the asteroid and we discuss our results in the context of the geophysical and collisional evolution of Vesta. In particular, we argue that the observational data are best reproduced if the bulk of the impactors was represented by 1-2 km wide planetesimals and if Jupiter underwent a limited (a fraction of au) displacement.

  14. The Formation of Jupiter, the Jovian Early Bombardment and the Delivery of Water to the Asteroid Belt: The Case of (4) Vesta

    Science.gov (United States)

    Turrini, Diego; Svetsov, Vladimir

    2014-01-01

    The asteroid (4) Vesta, parent body of the Howardite-Eucrite-Diogenite meteorites, is one of the first bodies that formed, mostly from volatile-depleted material, in the Solar System. The Dawn mission recently provided evidence that hydrated material was delivered to Vesta, possibly in a continuous way, over the last 4 Ga, while the study of the eucritic meteorites revealed a few samples that crystallized in presence of water and volatile elements. The formation of Jupiter and probably its migration occurred in the period when eucrites crystallized, and triggered a phase of bombardment that caused icy planetesimals to cross the asteroid belt. In this work, we study the flux of icy planetesimals on Vesta during the Jovian Early Bombardment and, using hydrodynamic simulations, the outcome of their collisions with the asteroid. We explore how the migration of the giant planet would affect the delivery of water and volatile materials to the asteroid and we discuss our results in the context of the geophysical and collisional evolution of Vesta. In particular, we argue that the observational data are best reproduced if the bulk of the impactors was represented by 1–2 km wide planetesimals and if Jupiter underwent a limited (a fraction of au) displacement. PMID:25370027

  15. A review on advanced methods in plant gene targeting

    Directory of Open Access Journals (Sweden)

    Raghavendrarao Sanagala

    2017-12-01

    Full Text Available Plant genetic engineering is one of the most significant tools implemented in the modern molecular crop breeding techniques. The conventional approaches of plant genetic transformation include Agrobacterium tumefaciens, particle bombardment, DNA uptake into protoplast. The transgenic events derived by these methods carry the transgenes that are integrated at random sites in the plant genome. Novel techniques that mediate integration of foreign genes at specific pre-determined locations circumvent many problems associated with the existing methods of gene transfer. The recent years have witnessed the emergence of gene targeting techniques by employing zinc finger nucleases (ZFNs, transcription activator-like effector nucleases (TALENs, and clustered regularly interspaced short palindrome repeats (CRISPR. The present review focuses on the various approaches and their performance of plant gene targeting and suggests future directions in the important areas of plant molecular biology.

  16. Antiproton Target

    CERN Multimedia

    1980-01-01

    Antiproton target used for the AA (antiproton accumulator). The first type of antiproton production target used from 1980 to 1982 comprised a rod of copper 3mm diameter and 120mm long embedded in a graphite cylinder that was itself pressed into a finned aluminium container. This assembly was air-cooled and it was used in conjunction with the Van der Meer magnetic horn. In 1983 Fermilab provided us with lithium lenses to replace the horn with a view to increasing the antiproton yield by about 30%. These lenses needed a much shorter target made of heavy metal - iridium was chosen for this purpose. The 50 mm iridium rod was housed in an extension to the original finned target container so that it could be brought very close to the entrance to the lithium lens. Picture 1 shows this target assembly and Picture 2 shows it mounted together with the lithium lens. These target containers had a short lifetime due to a combination of beam heating and radiation damage. This led to the design of the water-cooled target in...

  17. Effect of substrate thickness on ejection of phenylalanine molecules adsorbed on free-standing graphene bombarded by 10 keV C60

    Science.gov (United States)

    Golunski, M.; Verkhoturov, S. V.; Verkhoturov, D. S.; Schweikert, E. A.; Postawa, Z.

    2017-02-01

    Molecular dynamics computer simulations have been employed to investigate the effect of substrate thickness on the ejection mechanism of phenylalanine molecules deposited on free-standing graphene. The system is bombarded from the graphene side by 10 keV C60 projectiles at normal incidence and the ejected particles are collected both in transmission and reflection directions. It has been found that the ejection mechanism depends on the substrate thickness. At thin substrates mostly organic fragments are ejected by direct collisions between projectile atoms and adsorbed molecules. At thicker substrates interaction between deforming topmost graphene sheet and adsorbed molecules becomes more important. As this process is gentle and directionally correlated, it leads predominantly to ejection of intact molecules. The implications of the results to a novel analytical approach in Secondary Ion Mass Spectrometry based on ultrathin free-standing graphene substrates and a transmission geometry are discussed.

  18. Directional effect on coloration in LiF crystal by H{sup +} and H{sub 2}{sup +} ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Gan Mingle; Naramoto, Hiroshi; Aoki, Yasushi; Yamamoto, Shunya; Zeng Jianer; Takeshita, Hidefumi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    In the present paper, the first results are reported about the coloration in LiF crystals induced by bombardments of single hydrogen ions (H{sup +}) and molecular hydrogen ions (H{sub 2}{sup +}) with the same velocity under the <100> aligned and random conditions. For the single hydrogen ion irradiation, the coloration is rather simple. The F-type color center absorption under the <100> aligned condition becomes larger than that under the random condition with the dose increase because of larger fraction of electronic energy loss under channeling condition. On the contrary, the coloration for the molecular ions does not show big channeling effect. In the low dose region some difference can be seen but the difference of coloration is not observed any more with the dose increase. The pronounced coloration for molecular ions under the channeling condition is observed in comparison with that for single ions. (author)

  19. Stratigraphy, Sequence, and Crater Populations of Lunar Impact Basins from Lunar Orbiter Laser Altimeter (LOLA) Data: Implications for the Late Heavy Bombardment

    Science.gov (United States)

    Fassett, C. I.; Head, J. W.; Kadish, S. J.; Mazarico, E.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.

    2012-01-01

    New measurements of the topography of the Moon from the Lunar Orbiter Laser Altimeter (LOLA)[1] provide an excellent base-map for analyzing the large crater population (D.20 km)of the lunar surface [2, 3]. We have recently used this data to calculate crater size-frequency distributions (CSFD) for 30 lunar impact basins, which have implications for their stratigraphy and sequence. These data provide an avenue for assessing the timing of the transitions between distinct crater populations characteristic of ancient and young lunar terrains, which has been linked to the late heavy bombardment (LHB). We also use LOLA data to re-examine relative stratigraphic relationships between key lunar basins.

  20. Mega-Impacts on Mars: Implications for the Late Heavy Bombardment in the Inner Solar System, and the Early Evolution of the Earth and Mars

    Science.gov (United States)

    Frey, Herbert

    2012-01-01

    There are about 30 very large impact basins on Mars, > 1000 km in diameter, most of which are revealed by their topographic and/or crustal thickness signatures. Crater retention ages and model absolute ages suggest these all formed in a relatively short time (100-200 million years?), perhaps during a "Late Heavy Bombardment" (LHB) caused by the evolution of the orbits of the giant planets. This so-called "Nice Model" of planetary formation may explain the LHB on the Moon at about 3.9 billion years ago and would have produced a similar bombardment throughout the inner solar system. The formation of 30 very large impact basins would have had catastrophic environmental consequences for Mars, which were further complicated by the demise of the global magnetic field at about the same time. If there are no very large basins on Mars older than the 30 we see and the LHB really lasted everywhere only a short time, there may have been a relatively longer time (400 million years?) during which Mars and the Earth suffered no major impact trauma and during which conditions on both worlds may have been far more habitable than during the LHB. However, if the formation of the Mars crustal dichotomy was due to an even larger giant impact that predated the very large basins, all record of this earlier and possibly more clement time on Mars may have been erased. Ages of the smaller but still very large basins can be used to approximately date the giant impact (if it occurred). Even the very large basins appear to have reset the crater retention ages of the entire crust of Mars and may have by themselves erased any record of an earlier time.

  1. Strongly reduced fragmentation and soft emission processes in sputtered ion formation from amino acid films under large Ar(n)+ (n ≤ 2200) cluster ion bombardment.

    Science.gov (United States)

    Gnaser, Hubert; Ichiki, Kazuya; Matsuo, Jiro

    2012-01-15

    The analysis of organic and biological substances by secondary-ion mass spectrometry (SIMS) has greatly benefited from the use of cluster ions as primary bombarding species. Thereby, depth profiling and three-dimensional (3D) imaging of such systems became feasible. Large Ar(n)(+) cluster ions may constitute a further improvement in this direction. To explore this option, size-selected Ar(n)(+) cluster ions with 300 ≤ n ≤ 2200 (bombarding energies 5.5 and 11 keV) were used to investigate the emission of positive secondary ions from four amino acid specimens (arginine, glycine, phenylalanine, and tyrosine) by time-of-flight SIMS. For all cluster sizes, the protonated molecule of the respective amino acid is observed in the mass spectra. With increasing cluster size the number of fragment ions decreases strongly in relation to the intact molecules, to the extent that the fraction of fragment ions amounts to less than 10% in some cases. Such 'soft' emission processes also lead the ejection of dimers and even multimers of the amino acid molecules. In the case of the phenylalanine, secondary ion species composed of up to at least seven phenylalanine moieties were observed. Tentatively, the ionization probability of the emitted molecules is envisaged to depend on the presence of free protons in the emission zone. Their number can be expected to decrease concurrently with the decreasing amount of fragmentation for large Ar(n)(+) cluster ions (i.e. for low energies per cluster atom). Copyright © 2011 John Wiley & Sons, Ltd.

  2. Thermal Analysis for the Dense Granular Target of CIADS

    Directory of Open Access Journals (Sweden)

    Kang Chen

    2016-01-01

    Full Text Available For the China Initiative Accelerator Driven System (CIADS, the energy of the protons is 250 MeV, and the current intensity will reach 10 milliamperes. A new concept of a dense granular spallation target is proposed for which the tungsten granules are chosen as the target material. After being bombarded with the accelerated protons from the accelerator, the tungsten granules with high-temperature flow out of the subcritical reactor and the heat is removed by the heat exchanger. One key issue of the target is to remove the 2.5 MW heat deposition safely. Another one is the heat exchange between the target and the subcritical reactor. Based on the model of effective thermal conductivity, a new thermal code is developed in Matlab. The new code is used to calculate the temperature field of the target area near active zone and it is partly verified by commercial CFD code Fluent. The result shows that the peak temperature of the target zone is nearly 740°C and the reactor and the target are proved to be uncoupled in thermal process.

  3. CNT welding through Ar bombardment using AIREBO potential and optimization of an extensionded AIREO potential for F atom to simulate hydrofluorocarbons

    Science.gov (United States)

    Kucukkal, Mustafa Umut

    Molecular Dynamics (MD) is an effective method to study diverse systems to gain atomistic level details from the trajectories of particles in the system. MD require a potential which describes the interaction of the particles within the system, which is then used to solve Newton's equation of motion to obtain the trajectories of the particles. For an accurate simulation of a system, an appropriate potential should be used for the MD simulations. The Adaptive Interactive Reactive Empirical Bond Order (AIREBO) potential is a promising potential for MD simulations of systems involving bond breakage or formation [1, 2]. The AIREBO potential is a Tersoff-style bond order potential which adds LJ and torsional interactions to REBO potential developed by Brenner et al [3, 4]. Currently, the AIREBO potential is well parameterized to study carbonaceous and hydrocarbon systems. In the first part of this study, the AIREBO potential is used in MD simulations to study the welding of single wall carbon nanotubes (SWCNTs) through Ar bombardment. SWCNTs have unique electronic properties which make them an appropriate candidate to use in nanoscale transistor and nanocomputer studies. An optimum conductivity through SWCNTs is required for these applications in electronic devices and it is achieved by the bonding arrangements of the carbon atoms in the junction area. This spatial bonding between SWCNTs can be obtained by various experimental methods such as electron beam radiation, fast atom bombardment and chemical vapor deposition. This study focuses on simulating Ar bombardment over cross junction of two SWCNTs placed on an imaginary Lennard-Jones surface perpendicular to each other. The cross junction area of SWCNTs was bombarded with Ar atoms of various kinetic energies in microcanical ensemble which is followed by annealing at various temperatures. The main goal of this study is to find optimum conditions to obtain the highest number of connections between the SWCNTs and the

  4. Targeted Learning

    CERN Document Server

    van der Laan, Mark J

    2011-01-01

    The statistics profession is at a unique point in history. The need for valid statistical tools is greater than ever; data sets are massive, often measuring hundreds of thousands of measurements for a single subject. The field is ready to move towards clear objective benchmarks under which tools can be evaluated. Targeted learning allows (1) the full generalization and utilization of cross-validation as an estimator selection tool so that the subjective choices made by humans are now made by the machine, and (2) targeting the fitting of the probability distribution of the data toward the targe

  5. Electrons on the HDice target: Results and analysis of test runs at JLab in 2012

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, Michael; Bass, Christopher; D' Angelo, Annalisa; Deur, Alexandre; Hanretty, Charles; Ho, Dao; Kageya, Tsuneo; Laine, Vivien; Peng, Peng; Sandorfi, Andrew; Wei, Xiangdong; Whisnant, Charles

    2014-06-01

    During the Jefferson Labaratory E06-101 (g14) experiment \\cite{g14} utilizing photons on solid HD and performed in Hall B, two opportunities arose for targets to be subjected to multi-GeV electron beams in week-long campaigns of dose accumulation and NMR polarization measurements. This was in preparation for conditionally approved electron experiments after the 12 GeV JLab upgrade\\cite{trans}. Besides the important thermal effects, evidence consistent with screening of the NMR and with decay of the target polarization was observed during bombardment and for a time afterwards. The solid hydrogens have been the subject of previous radiation damage studies, both for possible polarized DT fusion\\cite{Forrest97} and for production of dynamically polarized nuclear targets\\cite{Radtke04}. We synthesize all this information into an overall picture that can guide on-going development of the HDice target system for future use.

  6. Dynamic effects of energetic beam on solid target material for positron production

    Energy Technology Data Exchange (ETDEWEB)

    Adeyemi, Olufemi S.; Kovalenko, Valentyn; Ushakov, Andriy; Malysheva, Larisa I. [University of Hamburg (Germany); Moortgat-Pick, Gudrid A. [University of Hamburg (Germany); Deutsches Elektronen-Synchrotron, Hamburg (Germany); Hartin, Anthony F. [Deutsches Elektronen-Synchrotron, Hamburg (Germany); Riemann, Sabine; Staufenbiel, Friedrich [Deutsches Elektronen-Synchrotron, Zeuthen (Germany)

    2012-07-01

    One of the big challenges for any future linear collider projects is to generate enough positrons to provide the required high luminosity. The International Linear Collider (ILC) foresees to generate polarized positrons via undulator radiation where the produced photon beam hits a solid Titanium alloy target. The bombardment of such a high-intense photon beam on titanium alloy deposits a huge amount of energy unto a very small spot on the target. Instantaneously this process changes the dynamical behaviour and the physical characteristic of the target material. This work presents a preliminary investigation of the dynamical behaviour of different solid target materials under such intense beams. In particular changes in the temperature and the induced stress are evaluated and discussed.

  7. Vacuum calculation of the TBID (Target Beam Instrumentation Downstream) for CNGS

    CERN Document Server

    Chiggiato, P

    2006-01-01

    For the TBID (Target Beam Instrumentation Downstream) monitor of CNGS (CERN Neutrinos to Gran Sasso) a design identical to that of the TBIU (Target Beam Instrumentation Upstream) monitor of the SPS targets has been adopted. However the vacuum solution implemented in the SPS, namely ion pumping, cannot be trivially applied to CNGS; in fact the high radioactivity level expected for the latter could damage the electrical cables in the about 10 years of expected activity and hinder or delay any human intervention. In this note the possibility of NEG pumping, without any electrical feeding, is considered. The getter should ensure the demanded pressure limit of 10-4 Torr in conditions that are very harsh: temperature up to 150°C, 0.1 A electron bombardment and proton bombardment during the 10 years of working of the monitor. It is shown that the beam induced CH4 pumping speed is not enough at the beginning of the operation to ensure the pressure requirements. In addition, in the worst scenario when a uniform ele...

  8. An apparatus for in situ spectroscopy of radiation damage of polymers by bombardment with high-energy heavy ions

    OpenAIRE

    BAAKE, Olaf; SEIDL, Tim; HOSSAIN, Umme Habiba; DELGADO, A. O.; BENDER, Markus; SEVERIN, Daniel; ENSINGER, Wolfgang

    2011-01-01

    A new target station providing Fourier transform infrared (FT-IR) spectroscopy and residual gas analysis (RGA) for in situ observation of ion-induced changes in polymers has been installed at the GSI Helmholtz Centre for Heavy Ion Research. The installations as well as first in situ measurements at room temperature are presented here. A foil of polyimide Kapton HN (R) was irradiated with 1.1 GeV Au ions. During irradiation several in situ FT-IR spectra were recorded. Simultaneously outgassing...

  9. Off-line tests on pitting damage in mercury target

    CERN Document Server

    Futakawa, M; Ishikura, S; Kogawa, H; Tsai, C C

    2003-01-01

    A liquid-mercury target system for the MW-scale target is being developed in the world. The moment the proton beams bombard the target, stress waves will be imposed on the beam window and pressure waves will be generated in the mercury by the thermally shocked heat deposition. Provided that the negative pressure generates through its propagation in the mercury target and causes cavitation in the mercury, there is the possibility for the cavitation bubbles collapse to form pits on the interface between the mercury and the target vessel wall. In order to estimate the cavitation erosion damage due to pitting, two types of off-line tests were performed: Split Hopkinson Pressure Bar (SHPB), and Magnetic IMpact Testing Machine (MIMTM). The data on the piping damage at the high cycle impacts up to 10 million were given by the MIMTM. Additionally the data obtained were compared with classical vibratory horn tests. As a result, it is confirmed that the mean depth erosion is predictable using a homologous line in the s...

  10. Neutron yield of thick {sup 12}C and {sup 13}C targets with 20 and 30 MeV deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Lhersonneau, G.; Fadil, M. [GANIL, Caen (France); Malkiewicz, T. [CSC - IT Center for Science Ltd., Espoo (Finland); Gorelov, D.; Sorri, J.; Trzaska, W.H. [University of Jyvaskyla, Department of Physics, Jyvaskyla (Finland); Jones, P.; Ngcobo, P.Z. [iThemba Laboratory for Accelerator Based Science, Western Cape (South Africa)

    2016-12-15

    The neutron yield of thick targets of carbon, natural and enriched in {sup 13}C, bombarded by deuterons of 20 and 30 MeV has been measured by the activation method. The gain with respect to a {sup 12}C target is the same as with protons beams. The yield ratio is about 1.2 only and hardly can justify the use of a {sup 13}C target with deuteron beams. The data, apart from being of interest for the design of facilities where secondary neutron beams are used, provide a test case for calculations where both beam and target have a weakly bound neutron. The MCNPx code version 2.6.0, despite failing to reproduce some details of the experimental distributions, describes their global properties fairly well, especially the relative yields of the {sup 12}C and {sup 13}C targets. (orig.)

  11. Application of the Photomodeler software and Matlab environment for analysisof objects movement parameters based on image sequences. (Polish Title: Wykorzystanie pakietu Photomodeler oraz środowiska Matlab, do badania parametrów ruchu obiektów na podstawie obrazów sekwencyjnych)

    Science.gov (United States)

    Markowski, T.

    2013-12-01

    Analysis of objects movement parameters is the area of interest of scientists representing many disciplines. Technological progress provides improvement of research methods. One of them is photogrammetry, and more specifically, close-range image sequences processing. Much research on different approaches to this issue are conducted all over the world. Proposed solution is to carry out photogrammetric measurements using one of the standard programs for close-range objects 3D modeling - PhotoModeler software and their mathematical processing using popular computing environment - Matlab software. Application of existing software's functionality, in many cases seems to be less costly than development and then implementation of specialized measuring and computing applications, dedicated to analysis of movement parameters. Considered solution is based primarily on the appropriate transformations of the frame of reference with respect to which the movement takes place. Automatic coded targets measurements and bundle adjustment, carried out using PhotoModeler software, were used in the research. In order to calculate objects movements parameters, there were further repeated isometric coordinates transformations, numerical differentiation in method of difference quotient and orientation by iterative tabulation with intervals narrowing additionally applied by building own Matlab environment functions. A number of experiments were performed using registration in the form of films from JVC GZ-HD5 digital video camera and films and series of photographs from Nikon D5000 digital photographic camera. Accomplished experiments covered different objects of movement parameters analysis and also distinct movement types. There were also three different versions of established frame of reference -movement of the camera in relation to surroundings, movement of the object in relation to the camera and movement of the object in relation to surrounding. Carried out research revealed that

  12. Effect of substrate thickness on ejection of phenylalanine molecules adsorbed on free-standing graphene bombarded by 10 keV C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Golunski, M. [Institute of Physics, Jagiellonian University, ul. Lojasiewicza 11, 30-348 Krakow (Poland); Verkhoturov, S.V.; Verkhoturov, D.S.; Schweikert, E.A. [Department of Chemistry, Texas A& M University, College Station, TX 77840 (United States); Postawa, Z., E-mail: zbigniew.postawa@uj.edu.pl [Institute of Physics, Jagiellonian University, ul. Lojasiewicza 11, 30-348 Krakow (Poland)

    2017-02-15

    Highlights: • Substrate thickness has a prominent effect on the molecular ejection mechanism. • Collisions with projectile atoms leads to molecular ejection at thin substrates. • Interactions with deforming graphene sheet ejects molecules from thicker substrates. • Probability of fragmentation process decreases with the graphene substrate thickness. - Abstract: Molecular dynamics computer simulations have been employed to investigate the effect of substrate thickness on the ejection mechanism of phenylalanine molecules deposited on free-standing graphene. The system is bombarded from the graphene side by 10 keV C{sub 60} projectiles at normal incidence and the ejected particles are collected both in transmission and reflection directions. It has been found that the ejection mechanism depends on the substrate thickness. At thin substrates mostly organic fragments are ejected by direct collisions between projectile atoms and adsorbed molecules. At thicker substrates interaction between deforming topmost graphene sheet and adsorbed molecules becomes more important. As this process is gentle and directionally correlated, it leads predominantly to ejection of intact molecules. The implications of the results to a novel analytical approach in Secondary Ion Mass Spectrometry based on ultrathin free-standing graphene substrates and a transmission geometry are discussed.

  13. Gene Gun Bombardment with DNA-Coated Golden Particles Enhanced the Protective Effect of a DNA Vaccine Based on Thioredoxin Glutathione Reductase of Schistosoma japonicum

    Directory of Open Access Journals (Sweden)

    Yan Cao

    2013-01-01

    Full Text Available Schistosomiasis, caused by infection with Schistosoma species, remains an important parasitic zoonosis. Thioredoxin glutathione reductase of Schistosoma japonicum (SjTGR plays an important role in the development of the parasite and for its survival. Here we present a recombinant plasmid DNA vaccine, pVAX1/SjTGR, to estimate its protection against S. japonicum in BALB/c mice. The DNA vaccine administrated by particle bombardment induced higher protection than by intramuscular injection. All animals vaccinated with pVAX1/SjTGR developed significant specific anti-SjTGR antibodies than control groups. Moreover, animals immunized by gene gun exhibited a splenocyte proliferative response, with an increase in IFN-γ and IL-4. The recombinant plasmid administrated by gene gun achieved a medium protective efficacy of 27.83–38.83% ( of worm reduction and 40.38–44.51% ( of liver egg count reduction. It suggests that different modes of administering a DNA vaccine can influence the protective efficacy induced by the vaccine. Interestingly, from the enzymatic activity results, we found that worms obtained from pVAX1/SjTGR-vaccinated animals expressed lower enzymatic activity than the control group and the antibodies weakened the enzymatic activity of SjTGR in vitro, too. It implies that the high-level antibodies may contribute to the protective effects.

  14. Computer simulations of material ejection during C{sub 60} and Ar{sub m} bombardment of octane and β-carotene

    Energy Technology Data Exchange (ETDEWEB)

    Palka, G.; Kanski, M.; Maciazek, D. [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow (Poland); Garrison, B.J. [Department of Chemistry, 104 Chemistry Building, Penn State University, University Park, PA 16802 (United States); Postawa, Z., E-mail: zbigniew.postawa@uj.edu.pl [Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow (Poland)

    2015-06-01

    Molecular dynamics (MD) computer simulations are used to investigate material ejection and fragment formation during keV C{sub 60} and Ar{sub m} (m = 60, 101, 205, 366, 872 and 2953) bombardment of organic solids composed from octane and β-carotene molecules at 0° and 45° impact angle. Both systems are found to sputter efficiently. For the octane system, material removal occurs predominantly by ejection of intact molecules, while fragment emission is a significant ejection channel for β-carotene. A difference in the molecular dimensions is proposed to explain this observation. It has been shown that the dependence of the sputtering yield Y on the primary kinetic energy E and the cluster size n can be expressed in a simplified form if represented in reduced units. A linear and nonlinear dependence of the Y/n on the E/n are identified and the position of the transition point from the linear to nonlinear regions depends on the size of the cluster projectile. The impact angle has a minor influence on the shape of the simplified representation.

  15. A simple shoot multiplication procedure using internode explants, and its application for particle bombardment and Agrobacterium-mediated transformation in watercress.

    Science.gov (United States)

    Ogita, Shinjiro; Usui, Miki; Shibutani, Nanae; Kato, Yasuo

    2009-07-01

    A shoot multiplication system derived from internode explants was investigated with the aim of improving genetic characteristics of watercress (Nasturtium officinale R. Br.). Internodes of ca. 1 cm excised from in vitro stock shoot culture were placed on half-strength Murashige and Skoog (MS) medium supplemented with 3 muM 2,4-dichlorophenoxyacetic acid as a pre-treatment. Laser scanning microscopy indicated clearly that the first sign of meristematic cell division could be seen after 1-2 days of pre-culture, and meristematic tissues multiplied along the vascular cambium of the internode segment during 7 days of culture. Multiple shoots could be obtained from more than 90% of the pre-treated explants when they were subsequently transferred to MS medium supplemented with 1 muM thidiazuron for 3 weeks. These findings indicate that pre-treatment of the internodes for 7 days promoted their capacity for organogenesis. Using this pre-treatment, frequent generation of transgenic watercress plants was achieved by adapting particle bombardment and Agrobacterium-mediated transformation techniques with a construct expressing a synthetic green florescent protein gene.

  16. Comparison of electron ionization and fast atom bombardment-mass spectrometry for the determination of nickel, vanadyl and free-base porphyrins

    Energy Technology Data Exchange (ETDEWEB)

    Castro, A.J.; Van Berkel, G.J.; Doolittle, F.G.; Filby, R.H. (Washington State Univ., Pullman (USA))

    1989-01-01

    Fast Atom Bombardment-Mass Spectrometry (FAB-MS) and Electron Ionization-Mass Spectrometry (EI-MS) at 12 and 70 eV, were used to obtain mass spectra of mesoporphyrin IX dimethylester (DME), tetraphenylporphyrin (TPP), octaethylporphyrin (OEP), and the metal-loporphyrins, Ni(DME), Ni(TPP), Ni(OEP), VO(TPP), VO(OEP), as well as a VO(II) porphyrin concentrate obtained from the New Albany oil shale bitumen (Mississippian-Devonian). A mixture of dithiothreitol/dithioerythritol (Magic Bullet) was used as the FAB matrix. Greater fragmentation of free-base and metalloporphyrins was observed in FAB mass spectra compared to the EI mass spectra. Adduct ions formed by addition of sulfur and a matrix molecule to the porphyrins were observed. In FAB spectra of the VO(II) complexes, loss of oxygen was noted. The FAB mass spectra of mixtures of VO(II) geoporphyrins are much more complex than corresponding EI mass spectra because of the greater fragmentation and the multiplicity of ions (M{sup +}, M + H, M + 2H, etc.) observed in the FAB mode. Using the matrices investigated, FAB is less suitable for EI for the mass spectrometric analysis of the geoporphyrins.

  17. Characterization of ion-bombardment induced modifications of periodic La/B{sub 4}C-multilayer-mirrors for the reflection of soft X-ray radiation

    Energy Technology Data Exchange (ETDEWEB)

    Merschjohann, Fabian; Lass, Maike; Gorholt, Lennart; Sacher, Marc D.; Heinzmann, Ulrich [Molecular and Surface Physics, Bielefeld University (Germany); Schaefers, Franz [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Elektronenspeicherring BESSY II (Germany)

    2010-07-01

    The applicability of reflective optical components for the soft X-Ray region depends on the existence of multilayer-optics. Therefore stacks of alternating layers of two materials with different refractive index are applied. For the photon energy range of 100-190 eV Lanthanum (La) is favoured as the absorber material and Boroncarbide (B{sub 4}C) as the spacer material. Thin periodic layer systems of those materials with double layer periods of 5.6 nm have been produced by UHV Electron Beam Evaporation. The layer thickness is controlled by in-situ X-Ray Reflectometry. The purity and the stoichiometry of the layers has been analyzed by electron beam induced in-situ Auger Spectroscopy. Ion Polishing of each interface should diminish the interface roughness and thus enhance the reflectivity. The modification of the La- and B{sub 4}C-layers due to ion bombardment has been investigated by the in-situ Auger Spectroscopy, ex-situ X-Ray Diffraction and at-wavelength reflectivity measurements by use of Synchrotron radiation at the BESSY II facility. Effects of compaction, mixing, sputter-etching and smoothing have been found. The modifications can be influenced by varying the kinetic energy of the ions and/or the duration of the treatment.

  18. Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

    Energy Technology Data Exchange (ETDEWEB)

    Suyanto, Hery [Department of Physics, Faculty of Mathematics and Natural Sciences, Udayana University, Kampus Bukit Jimbaran, Denpasar 80361, Bali (Indonesia); Pardede, Marincan [Department of Electrical Engineering, University of Pelita Harapan, 1100 M.H. Thamrin Boulevard, Lippo Village, Tangerang 15811 (Indonesia); Hedwig, Rinda [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Marpaung, Alion Mangasi [Department of Physics, Faculty of Mathematics and Natural Sciences, Jakarta State University, Rawamangun, Jakarta 12440 (Indonesia); Ramli, Muliadi [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Lie, Tjung Jie; Kurniawan, Koo Hendrik, E-mail: kurnia18@cbn.net.id [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Abdulmadjid, Syahrun Nur [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Tjia, May On [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Physics of Magnetism and Photonics Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha,Bandung 40132 (Indonesia); Kagawa, Kiichiro [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Fukui Science Education Academy, Takagi Chuo 2 chome, Fukui 910-0804 (Japan)

    2016-08-15

    A time-resolved spectroscopic study is performed on the enhancement signals of He gas plasma emission using nanosecond (ns) and picosecond (ps) lasers in an orthogonal configuration. The ns laser is used for the He gas plasma generation and the ps laser is employed for the ejection of fast electrons from a metal target, which serves to excite subsequently the He atoms in the plasma. The study is focused on the most dominant He I 587.6 nm and He I 667.8 nm emission lines suggested to be responsible for the He-assisted excitation (HAE) mechanism. The time-dependent intensity enhancements induced by the fast electrons generated with a series of delayed ps laser ablations are deduced from the intensity time profiles of both He emission lines. The results clearly lead to the conclusion that the metastable excited triplet He atoms are actually the species overwhelmingly produced during the recombination process in the ns laser-induced He gas plasma. These metastable He atoms are believed to serve as the major energy source for the delayed excitation of analyte atoms in ns laser-induced breakdown spectroscopy (LIBS) using He ambient gas.

  19. Comparisons of the simulation results using different codes for ADS spallation target

    CERN Document Server

    Yu Hong Wei; Shen Qing Biao; Wan Jun Sheng; Zhao Zhi Xiang

    2002-01-01

    The calculations to the standard thick target were made by using different codes. The simulation of the thick Pb target with length of 60 cm, diameter of 20 cm bombarded with 800, 1000, 1500 and 2000 MeV energetic proton beam was carried out. The yields and the spectra of emitted neutron were studied. The spallation target was simulated by SNSP, SHIELD, DCM/CEM (Dubna Cascade Model /Cascade Evaporation Mode) and LAHET codes. The Simulation Results were compared with experiments. The comparisons show good agreement between the experiments and the SNSP simulated leakage neutron yield. The SHIELD simulated leakage neutron spectra are in good agreement with the LAHET and the DCM/CEM simulated leakage neutron spectra

  20. Investigation of the radionuclide inventory and the production yields of the target stacks at the PEFP radioisotope production facility

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Sang-Pil; Hong, In-Seok; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-06-15

    The Proton Engineering Frontier Project (PEFP) will construct a radioisotope production facility by using the nuclear reaction between the 100-MeV proton beam and the solid target. For investigating the radionuclide inventory and the production yield of the radioisotope production facility, we have optimized the thickness of the prototype target stacks by using a SRIM calculation. The target stacks consist of RbCl encapsulated in inconel alloy, Zn metal, and Ga metal encapsulated in niobium. Typical beam parameters were 300 {mu}A and 95 hours. An inventory of all generated radionuclide activities is mandatory in order to prepare the operation scenario and design the hot cell. The Monte Carlo code MCNPX was used to investigate what radionuclide is generated. The obtained radionuclide inventory indicated that about 100 radionuclides were generated and that the total radioactivity of the irradiated target stacks was 1324.1 Ci at the end of the bombardment. The production yields of Sr-82, Cu-67, and Ge-68 were 3.79 Ci, 2.74 Ci, and 1.23 Ci at the end of the bombardment.

  1. Production of copper-64 and gallium-68 with a medical cyclotron using liquid targets

    Science.gov (United States)

    Alves, F.; Alves, V. H. P.; Do Carmo, S. J. C.; Neves, A. C. B.; Silva, M.; Abrunhosa, A. J.

    2017-06-01

    This work describes the production of two clinically relevant metal radioisotopes 64Cu and 68Ga with a medical cyclotron by the irradiation of liquid targets. New results are presented for the implementation of this methodology in a fully automated system, using commercially available equipment. Liquid target solutions containing enriched 64Ni and 68Zn were loaded, bombarded and transferred to synthesis modules where a purified solution containing the desired radiometal is obtained and can then be used to further radiolabeling within only one hour after End-Of-Bombardment (EOB). Typical production runs using enriched material lead to the production of 5 GBq and 6 GBq (0.14 MBq/(μAh ṡ mg) and 1.5 MBq/(μAh ṡ mg)) of 64Cu and 68Ga; although the technique can be used to obtain up to 25 GBq and 40 GBq, respectively, by simply scaling up the amount of the enriched material. Purified solutions containing 64Cu and 68Ga were obtained within 30 min after EOB and used to produce 64Cu-ATSM and 68Ga-DOTA-NOC, respectively, with quality parameters suitable for human use.

  2. Olgunlaşmış Arpa (Hordeum vulgare L.) Embriyolarına Partikül Bombardımanı Tekniği İle Markör Gen Aktarımı

    OpenAIRE

    KOYUNCU, N.; ÖZGEN, M.

    2014-01-01

    Tahıllarda son yıllarda büyük aşama kaydeden partikül bombardımanı tekniğinin arpaya (H. vulgare L.) uygulanarak markör gen aktarımı olanaklarının araştırılması ve olgun embriyo bombardımanı için en uygun fiziksel parametrelerin (bombardıman basıncı ve mesafesi) belirlenmesi amacıyla yapılan bu çalışma 2000 yılında Ankara Üniversitesi Ziraat Fakültesi Tarla Bitkileri Bölümü Biyoteknoloji Laboratuvarında yürütülmüştür. Araştırmada bitki materyali olarak Türkiye’de yaygın olarak yetiştirilen “T...

  3. The unexpected formation of Au{sup {delta}+}-Si{sup {delta}-} by the resonance neutralization of Ar{sup +} during the low energy bombardment of Au nanoparticles on c-Si

    Energy Technology Data Exchange (ETDEWEB)

    Yang Dequan [Regroupement Quebecois de Materiaux de Pointe, Departement de Genie Physique, Ecole Polytechnique, C.P. 6079, succursale Centre-Ville, Montreal, Quebec H3C 3A7 (Canada); Sacher, Edward, E-mail: edward.sacher@polymtl.ca [Regroupement Quebecois de Materiaux de Pointe, Departement de Genie Physique, Ecole Polytechnique, C.P. 6079, succursale Centre-Ville, Montreal, Quebec H3C 3A7 (Canada)

    2009-05-15

    Nanoscale Au layers, with irregular porosities, have been formed by the low energy Ar{sup +} bombardment of Au nanoparticles that were sputter-deposited onto native oxide-covered Si surfaces. High-resolution field emission scanning electron microcopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS) have been used to characterize the formation and evolution of the nanoporous layer. Under Ar{sup +} bombardment, the Au nanoparticles that were initially deposited were observed to flatten and spread across the native oxide surface, without diffusing, finally coalescing at their edges to form a nanoporous film having irregular pore dimensions. XPS showed that this evolution was accompanied by the loss of Au as a result of sputtering. The formation of such porous films necessitates strong interfacial bonding to avoid the lateral diffusion of the Au nanoparticles, and their ultimate coalescence into larger nanoparticles. We demonstrated that Ar{sup +} beam bombardment invariably caused the formation of Au{sup {delta}+}-Si{sup {delta}-} bonding, rather than the expected Au{sup {delta}-}-Si{sup {delta}+} bonding, and we explain this to be due to the resonance neutralization of the Ar{sup +} beam on impacting the Au layer. We also reveal that the presumed formation of AuSi{sub x} is not quantifiable by XPS, due to the superposition of the chemical shift of the Au nanoparticles with that of the quantum size effect, during Au loss on sputtering.

  4. Development of an Automated Target Oscillator For Use in Reaction Studies

    Science.gov (United States)

    Martin, William; Bardayan, D. W.; Jones, K. L.; Cizewski, J. A.

    2009-10-01

    When a high current (greater than 10^6 particles per second) of heavy ion beam bombards a plastic target, the energy deposition and heat buildup can cause target degradation. In the case of calibration/pilot beams used on thin (100-250μg/cm2) deuterated polyethylene targets, even a short exposure has been found to result in damages such as cracking, burn through, and target carbonization/oxidation. One way to reduce the deleterious effects of this accumulated energy is to oscillate the target, thereby spreading the deposited energy over a larger area and allowing for an increased rate of heat dissipation. At the HRIBF in Oak Ridge, an automated target oscillation system has been developed using an electronic stepper motor and a control unit equipped with a custom Field Programmable Gated Array (FPGA) circuit board. Taking into consideration varying target sizes and beam densities, the algorithm loaded onto the FPGA allows the user to adjust both the frequency and amplitude of oscillation. Conclusive testing shows that incorporation of the target oscillator apparatus introduces no detectable electromagnetic noise to the detector array. Live beam testing is planned in the near future, and it is anticipated that the target oscillator will greatly assist HRIBF's efforts to maintain target integrity during calibration and experiments.

  5. Investigation of ground target detection methods in fully polarimetric wide angle synthetic aperture radar images

    Science.gov (United States)

    Laggan, Wayne B.

    1995-03-01

    Target detection is a high priority of the Air Force for the purpose of reconnaissance and bombardment. This research investigates and develops methods to distinguish ground targets from clutter (i.e. foliage, landscape etc.) in Wide Angle Synthetic Aperture Radar (WASAR) images. WASAR uses multiple aspect angle SAR images of the same target scene. The WASAR data was generated from a pre-release software package (XPATCH-ES) provided by the sponsor (WL-AARA). A statistical analysis and feature extraction is performed on the XPATCH-ES data. Polarimetric and wide angle covariance matrices are estimated and analyzed. From an analysis of the wide angle covariance matrix it is shown that natural clutter has in general a uniform radar return for changing aspect angles, whereas the radar return for a target varies. Based on this analysis, two new wide angle algorithms, the WASAR Whitening Filter and the Adaptive WASAR Whitening Filter (AWWF) are developed. The target detection performance of polarimetric and multi aspect angle image combining algorithms are quantified using Receiver Operating Characteristic curves and target to clutter ratios. It is shown that wide angle processing provides superior target detection performance over polarimetric processing. Combinations of wide angle and polarimetric algorithms were used to achieve a 13.7 dB processing gain in target to clutter ratio when compared to unprocessed images of the target scene. This represents a significant improvement in target detection capabilities.

  6. Dry Distillation of Radioiodine from TeO2 Targets

    Directory of Open Access Journals (Sweden)

    Jacek Koziorowski

    2013-10-01

    Full Text Available As medical cyclotrons are becoming more abundant, 123I and 124I are getting more attention as alternatives to 131I for diagnostics of thyroid disease. Both 123I and 124I provide better diagnostics, deliver less dose to patients and both reduce the risk of thyroid stunning, facilitating subsequent therapy. Dry distillation of radioiodine from tellurium dioxide targets has become the standard approach to producing these radioiodines. Setting up such a production of radioiodine is associated with a lengthy optimization of the process and for this purpose natural tellurium is often used for economical reasons. In this paper, the distillation parameters are scrutinized to ensure optimal distillation temperature, in order to minimize time spent and prevent loss of expensive target material. It is further demonstrated how the individual iodine isotopes, produced from proton bombardment of natTe, will diffuse out of the target in a time dependent ratio. We believe the effect is due to the isotopes having their maximum cross section at different energies. The individual isotopes produced will thus have their highest concentration at different depths in the target. This results in individual mean diffusion lengths and diffusion times for the different isotopes.

  7. Spallation Neutron Spectrum on a Massive Lead/Paraffin Target Irradiated with 1 GeV Protons

    CERN Document Server

    Adam, J; Barashenkov, V S; Brandt, R; Golovatiouk, V M; Kalinnikov, V G; Katovsky, K; Krivopustov, M I; Kumar, V; Kumawat, H; Odoj, R; Pronskikh, V S; Solnyshkin, A A; Stegailov, V I; Tsoupko-Sitnikov, V M; Westmeier, W

    2004-01-01

    The spectra of gamma-ray emitted by decaying residual nuclei, produced by spallation neutrons with (n, xn), (n,xnyp), (n,p), (n,gamma) reactions in activation threshold detectors - namely, ^{209}Bi, ^{197}Au, ^{59}Co, ^{115}In, ^{232}Th, were measured in the Laboratory of Nuclear Problems (LNP), JINR, Dubna, Russia. Spallation neutrons were generated by bombarding a 20 cm long cylindrical lead target, 8 cm in diameter, surrounded by a 6 cm thick layer of paraffin moderator, with a 1 GeV proton beam from the Nuclotron accelerator. Reaction rates and spallation neutron spectrum were measured and compared with CASCADE code calculations.

  8. Reactive Molecular Simulation of the Damage Mitigation Efficacy of POSS-, Graphene-, and Carbon Nanotube-Loaded Polyimide Coatings Exposed to Atomic Oxygen Bombardment.

    Science.gov (United States)

    Rahmani, Farzin; Nouranian, Sasan; Li, Xiaobing; Al-Ostaz, Ahmed

    2017-04-12

    Reactive molecular dynamics simulation was employed to compare the damage mitigation efficacy of pristine and polyimide (PI)-grafted polyoctahedral silsesquioxane (POSS), graphene (Gr), and carbon nanotubes (CNTs) in a PI matrix exposed to atomic oxygen (AO) bombardment. The concentration of POSS and the orientation of Gr and CNT nanoparticles were further investigated. Overall, the mass loss, erosion yield, surface damage, AO penetration depth, and temperature evolution are lower for the PI systems with randomly oriented CNTs and Gr or PI-grafted POSS compared to those of the pristine POSS or aligned CNT and Gr systems at the same nanoparticle concentration. On the basis of experimental early degradation data (before the onset of nanoparticle damage), the amount of exposed PI, which has the highest erosion yield of all material components, on the material surface is the most important parameter affecting the erosion yield of the hybrid material. Our data indicate that the PI systems with randomly oriented Gr and CNT nanoparticles have the lowest amount of exposed PI on the material surface; therefore, a lower erosion yield is obtained for these systems compared to that of the PI systems with aligned Gr and CNT nanoparticles. However, the PI/grafted-POSS system has a significantly lower erosion yield than that of the PI systems with aligned Gr and CNT nanoparticles, again due to a lower amount of exposed PI on the surface. When comparing the PI systems loaded with PI-grafted POSS versus pristine POSS at low and high nanoparticle concentrations, our data indicate that grafting the POSS and increasing the POSS concentration lower the erosion yield by a factor of about 4 and 1.5, respectively. The former is attributed to a better dispersion of PI-grafted POSS versus that of the pristine POSS in the PI matrix, as determined by the radial distribution function.

  9. Electrical characterization of deep levels created by bombarding nitrogen-doped 4H-SiC with alpha-particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Omotoso, Ezekiel, E-mail: ezekiel.omotoso@up.ac.za [Department of Physics, University of Pretoria, Private Bag X20, Hatfield 0028 (South Africa); Departments of Physics, Obafemi Awolowo University, Ile-Ife 220005 (Nigeria); Meyer, Walter E., E-mail: wmeyer@up.ac.za [Department of Physics, University of Pretoria, Private Bag X20, Hatfield 0028 (South Africa); Auret, F. Danie; Paradzah, Alexander T.; Legodi, Matshisa J. [Department of Physics, University of Pretoria, Private Bag X20, Hatfield 0028 (South Africa)

    2016-03-15

    Deep-level transient spectroscopy (DLTS) and Laplace-DLTS were used to investigate the effect of alpha-particle irradiation on the electrical properties of nitrogen-doped 4H-SiC. The samples were bombarded with alpha-particles at room temperature (300 K) using an americium-241 ({sup 241}Am) radionuclide source. DLTS revealed the presence of four deep levels in the as-grown samples, E{sub 0.09}, E{sub 0.11}, E{sub 0.16} and E{sub 0.65}. After irradiation with a fluence of 4.1 × 10{sup 10} alpha-particles-cm{sup −2}, DLTS measurements indicated the presence of two new deep levels, E{sub 0.39} and E{sub 0.62} with energy levels, E{sub C} – 0.39 eV and E{sub C} – 0.62 eV, with an apparent capture cross sections of 2 × 10{sup −16} and 2 × 10{sup −14} cm{sup 2}, respectively. Furthermore, irradiation with fluence of 8.9 × 10{sup 10} alpha-particles-cm{sup −2} resulted in the disappearance of shallow defects due to a lowering of the Fermi level. These defects re-appeared after annealing at 300 °C for 20 min. Defects, E{sub 0.39} and E{sub 0.42} with close emission rates were attributed to silicon or carbon vacancy and could only be separated by using high resolution Laplace-DLTS. The DLTS peaks at E{sub C} – (0.55–0.70) eV (known as Z{sub 1}/Z{sub 2}) were attributed to an isolated carbon vacancy (V{sub C}).

  10. Manufacturing W fibre-reinforced Cu composite pipes for application as heat sink in divertor targets of future nuclear fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Alexander v.; You, Jeong-Ha [Max-Planck-Institut fuer Plasmaphysik, 85748 Garching (Germany); Ewert, Dagmar [Institut fuer Textil- und Verfahrenstechnik Denkendorf, 73770 Denkendorf (Germany); Siefken, Udo [Louis Renner GmbH, 85221 Dachau (Germany)

    2016-07-01

    An important plasma-facing component (PFC) in future nuclear fusion reactors is the so-called divertor which allows power exhaust and removal of impurities from the main plasma. The most highly loaded parts of a divertor are the target plates which have to withstand intense particle bombardment. This intense particle bombardment leads to high heat fluxes onto the target plates which in turn lead to severe thermomechanical loads. With regard to future nuclear fusion reactors, an improvement of the performance of divertor targets is desirable in order to ensure reliable long term operation of such PFCs. The performance of a divertor target is most closely linked to the properties of the materials that are used for its design. W fibre-reinforced Cu (Wf/Cu) composites are regarded as promising heat sink materials in this respect. These materials do not only feature adequate thermophysical and mechanical properties, they do also offer metallurgical flexibility as their microstructure and hence their macroscopic properties can be tailored. The contribution will point out how Wf/Cu composites can be used to realise an advanced design of a divertor target and how these materials can be fabricated by means of liquid Cu infiltration.

  11. Analysis of an XADS Target with the System Code TRACE

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Wadim; Sanchez Espinoza, Victor H. [Forschungszentrum Karlsruhe GmbH, Institute for Reactor Safety, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Feng, Bo [Massachusetts Institute of Technology, 77 Massachusetts Avenue, NW12-219, Cambridge, MA 02139 (United States)

    2008-07-01

    Accelerator-driven systems (ADS) present an option to reduce the radioactive waste of the nuclear industry. The experimental Accelerator-Driven System (XADS) has been designed to investigate the feasibility of using ADS on an industrial scale to burn minor actinides. The target section lies in the middle of the subcritical core and is bombarded by a proton beam to produce spallation neutrons. The thermal energy produced from this reaction requires a heat removal system for the target section. The target is cooled by liquid lead-bismuth-eutectics (LBE) in the primary system which in turn transfers the heat via a heat exchanger (HX) to the secondary coolant, Diphyl THT (DTHT), a synthetic diathermic fluid. Since this design is still in development, a detailed investigation of the system is necessary to evaluate the behavior during normal and transient operations. Due to the lack of experimental facilities and data for ADS, the analyses are mostly done using thermal hydraulic codes. In addition to evaluating the thermal hydraulics of the XADS, this paper also benchmarks a new code developed by the NRC, TRACE, against other established codes. The events used in this study are beam power switch-on/off transients and a loss of heat sink accident. The obtained results from TRACE were in good agreement with the results of various other codes. (authors)

  12. Applications of electrical resistivity measurements to research into the purification of uranium using floating molten zone by electronic bombardment; Applications des mesures de resistivite electrique a l'etude de la purification de l'uranium par fusion de zone flottante par bombardement electronique

    Energy Technology Data Exchange (ETDEWEB)

    Pascal, J.L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-02-01

    The purification of uranium has been achieved by zone melting. Because of the high affinity of uranium towards elements such as oxygen, contamination has been avoided by adopting the floating zone technique and by working under high vacuum. The difficulties created by the deformations of uranium rod, which are caused by anisotropy of dilatation of phases {alpha} and {beta} and allotropic transformations {alpha} {r_reversible} {beta} and {beta} {r_reversible} {alpha}, have been overcome by the use of electron bombardment stabilized by feedback. A rough control of the purification was obtained by micrographic examination, microhardness measurements, and tests of secondary recrystallization, allowed us to appreciate the new degree of purity of the uranium obtained. The investigation of the purity degree was pursued by electrical resistivity measurements at 20 deg. K. But one had to take care in the interpretation of those measurements of the anisotropy of the uranium resistivity and the influence of structure on residual resistivity. Those measurements have led us, by determination of single crystal and uranium resistivity, to be able to distinguish between the principal resistivity against axis [100] and [010]. (author) [French] La purification de l'uranium a ete realisee par l'application de la methode dite de la zone fondue. L'uranium etant particulierement reactif vis-a-vis d'elements tels que l'oxygene, les risques de contamination ont ete supprimes en adoptant la technique de la zone flottante et en operant sous vide eleve. Les difficultes creees par les deformations du barreau d'uranium, dues a l'anisotropie de dilatation des phases {alpha} et {beta} et ou passage des deux points de transformation allotropiques {alpha} {r_reversible} {beta} et {beta} {r_reversible} {alpha}, ont pu etre surmontees par l'emploi du chauffage par bombardement electronique, stabilise par un systeme tres simple de contre reaction. Un premier

  13. MEET ISOLDE - Target Production

    CERN Multimedia

    2017-01-01

    MEET ISOLDE - Target Production. Everything at ISOLDE starts with a target and the target production team realise on more then 50 years of experience to build and develop new targets for ISOLDE’s wide physics program.

  14. Asteroids and Archaean crustal evolution: Tests of possible genetic links between major mantle/crust melting events and clustered extraterrestrial bombardments

    Science.gov (United States)

    Glikson, A. Y.

    1992-09-01

    Since the oldest intact terrestrial rocks of ca. 4.0 Ga and oldest zircon xenocrysts of ca. 4.3 Ga measured to date overlap with the lunar late heavy bombardment, the early Precambrian record requires close reexamination vis a vis the effects of megaimpacts. The identification of microtektite-bearing horizons containing spinals of chondritic chemistry and Ir anomalies in 3.5-3.4-Ga greenstone belts provides the first direct evidence for large-scale Archaean impacts. The Archaean crustal record contains evidence for several major greenstone-granite-forming episodes where deep upwelling and adiabatic fusion of the mantle was accompanied by contemporaneous crustal anatexis. Isotopic age studies suggest evidence for principal age clusters about 3.5, 3.0, and 2.7 (+/- 0.8) Ga, relics of a ca. 3.8-Ga event, and several less well defined episodes. These peak events were accompanied and followed by protracted thermal fluctuations in intracrustal high-grade metamorphic zones. Interpretations of these events in terms of internal dynamics of the Earth are difficult to reconcile with the thermal behavior of silicate rheologies in a continuously convecting mantle regime. A triggering of these episodes by mantle rebound response to intermittent extraterrestrial asteroid impacts is supported by (1) identification of major Archaean impacts from microtektite and distal ejecta horizons marked by Ir anomalies; (2) geochemical and experimental evidence for mantle upwelling, possibly from levels as deep as the transition zone; and (3) catastrophic adiabatic melting required to generate peridotitic komatites. Episodic differentiation/accretion growth of sial consequent on these events is capable of resolving the volume problem that arises from comparisons between modern continental crust and the estimated sial produced by continuous two-stage mantle melting processes. The volume problem is exacerbated by projected high accretion rates under Archaean geotherms. It is suggested that

  15. Circumplanetary Debris Disks in the Solar System and Beyond: Is the Fomalhaut System on the Verge of a Late Heavy Bombardment?

    Science.gov (United States)

    Tamayo, Daniel; Burns, J. A.

    2014-01-01

    it is the only object dynamically interacting with the belt, the debris disk’s eccentricity will continue rising to values near unity, perhaps causing an event analogous to the Late Heavy Bombardment hypothesized to have occurred in the early Solar System.

  16. The mechanisms of negative oxygen ion formation from Al-doped ZnO target and the improvements in electrical and optical properties of thin films using off-axis dc magnetron sputtering at low temperature

    Science.gov (United States)

    Nguyen, Huu Chi; Thuy Trinh, Thanh; Le, Tran; Tran, Cao Vinh; Tran, Tuan; Park, Hyeongsik; Dao, Vinh Ai; Yi, Junsin

    2011-10-01

    Transparent conducting aluminum-doped zinc oxide (AZO) films have been prepared on glass substrates by dc magnetron sputtering using ceramic ZnO with 2 wt% Al2O3 target. The mechanism of negative oxygen ion generation on an AZO target surface and its influence on the conductivity of films were discussed. The negative ion generation on an AZO target was contributed by the surface ionization leading to the spot emission from Al atoms adsorbed on the AZO target surface. The contribution of negative ions' current was mainly from the erosion area of the target due to its higher temperature. To reduce the damage caused by negative ion bombardment to film growth, an off-axis sputtering system was proposed, where the substrates were placed perpendicular to the target. The effects of distance (d) on the electrical properties of films were experimentally verified in detail. A low resistivity of 3.7 × 10-4 Ω cm, an average transmittance above 85% in the visible range (300-800 nm) and reflectance higher than 85% in the infrared range (2500-4000 nm) were obtained for the films deposited at d = 2.5 cm. The overall analysis revealed that the generation of negative ions on the AZO target has a great influence on film growth, especially in the ultra-low pressure deposition process. Our work demonstrates the feasibility of reducing the negative effects of ion bombardment on the quality of films, which would be of great merit for industrial applications.

  17. Metabolism of 15-(4'-[[sup 123]I]iodophenyl)pentadecanoic acid ([[sup 123]I]IPPA) in the rat heart; identification of new metabolites by high pressure liquid chromatography and fast atom bombardment-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhut, Michael; Suetterle, Andreas (Heidelberg Univ. (Germany). Abt. fuer Klinische Nuklearmedizin); Lehmann, W.D. (Deutsches Krebsforschungszentrum, Heidelberg (Germany))

    1993-08-01

    The metabolism of 15-(4'-iodophenyl)pentadecanoic acid (IPPA) in the heart muscle is commonly believed to end at 4-iodobenzoic acid as the main and final product of [beta]-oxidation. However, investigation of the metabolic fate of IPPA in Langendorff rat hearts using high pressure liquid chromatography (HPLC) and negative fast atom bombardment mass spectrometry (FAB-MS) revealed new results. This metabolic behaviour may be of importance for the interpretation of sequential heart scintigraphy performed with [[sup 123]I]IPPA. (author).

  18. Using MDECR-PECVD to study the impact of ion bombardment energy on microstructural properties of μc-Si:H thin film grown from an SiF{sub 4}/H{sub 2} chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junkang; Florea, Ileana; Bulkin, Pavel V.; Maurice, Jean-Luc; Johnson, Erik V. [LPICM, CNRS, Ecole Polytechnique, Universite Paris Saclay, 91128 Palaiseau (France)

    2016-12-15

    The matrix-distributed electron cyclotron resonance plasma-enhanced chemical vapor deposition (MDECR-PECVD) technique has been shown to achieve high deposition rates for hydrogenated microcrystalline silicon (μc-Si:H) thin film. Due to the fact that plasma is sustained by a microwave discharge, by biasing the substrate holder with additional power supply, one can achieve independent control over the plasma density and the maximum ion bombardment energy (IBE). In this work, we present studies of the impact of IBE on the microstructural properties of the μc-Si:H film deposited by MDECR-PECVD. Insufficient ion bombardment is found to be responsible for the substantial presence of nano-porous regions within the material, resulting in significant post-deposition oxidation. Good agreement between transmission electron microscopy (TEM) Fresnel contrast analysis and the results of infrared absorption and hydrogen effusion measurements for the deposited films suggest that moderate IBE is of vital importance to achieve high quality μc-Si:H. In doing so, denser films with significantly decreased nano-porous regions and better stability are obtained, which is of great interest to optimize the process parameters for solar cell applications. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Large scale and orientation-controllable nanotip structures on CuInS₂, Cu(In,Ga)S₂, CuInSe₂, and Cu(In,Ga)Se₂ by low energy ion beam bombardment process: growth and characterization.

    Science.gov (United States)

    Yen, Yu-Ting; Wang, Yi-Chung; Chen, Yu-Ze; Tsai, Hung-Wei; Hu, Fan; Lin, Shih-Ming; Chen, Yi-Ju; Lai, Chih-Chung; Liu, Wenlong; Wang, Tsang-Hsiu; Hong, Hwen-Fen; Chueh, Yu-Lun

    2014-06-11

    One-step facile methodology to create nanotip arrays on chalcopyrite materials (such as CuInS2, Cu(In,Ga)S2, CuInSe2, and Cu(In,Ga)Se2) via a low energy ion beam bombardment process has been demonstrated. The mechanism of formation for nanotip arrays has been proposed by sputtering yields of metals and reduction of metals induced by the ion beam bombardment process. The optical reflectance of these chalcopyrite nanotip arrays has been characterized by UV-vis spectrophotometer and the efficient light-trapping effect has been observed. Large scale (∼4'') and high density (10(10) tips/cm(2)) of chalcopyrite nanotip arrays have been obtained by using low ion energy (< 1 kV), short processing duration (< 30 min), and template-free. Besides, orientation and length of these chalcopyrite nanotip arrays are controllable. Our results can be the guide for other nanostructured materials fabrication by ion sputtering and are available for industrial production as well.

  20. Quantitative evaluation of high-energy O- ion particle flux in a DC magnetron sputter plasma with an indium-tin-oxide target

    Science.gov (United States)

    Suyama, Taku; Bae, Hansin; Setaka, Kenta; Ogawa, Hayato; Fukuoka, Yushi; Suzuki, Haruka; Toyoda, Hirotaka

    2017-11-01

    O- ion flux from the indium tin oxide (ITO) sputter target under Ar ion bombardment is quantitatively evaluated using a calorimetry method. Using a mass spectrometer with an energy analyzer, O- energy distribution is measured with spatial dependence. Directional high-energy O- ion ejected from the target surface is observed. Using a calorimetry method, localized heat flux originated from high-energy O- ion is measured. From absolute evaluation of the heat flux from O- ion, O- particle flux in order of 1018 m-2 s-1 is evaluated at a distance of 10 cm from the target. Production yield of O- ion on the ITO target by one Ar+ ion impingement at a kinetic energy of 244 eV is estimated to be 3.3  ×  10-3 as the minimum value.

  1. Target preparation and characterization for multielemental analysis of liquid samples by use of accelerators

    CERN Document Server

    Liendo, J A; Fletcher, N R; Gómez, J; Caussyn, D D; Myers, S H; Castelli, C; Sajo-Bohus, L

    1999-01-01

    Elastic scattering at forward angles is tested as a useful alternative method to characterize liquid samples of scientific and/or technological interest. Solid residues of such samples deposited on light backings have been bombarded with 16 MeV sup 7 Li and 24 MeV sup 1 sup 6 O beams in order to determine the experimental configuration giving the best elemental mass separation. The elastically scattered ions were detected at 16 deg. , 20 deg. and 28 deg. with surface barrier detectors. The ratios between the mass separation and the line width obtained in the spectral region between carbon and oxygen varied between 2 and 13. This method is particularly useful for an accurate elemental characterization below sodium which is beyond the scope of standard techniques such as PIXE and TXRF provided the ion beam type, its kinetic energy and the target thickness are considered simultaneously.

  2. Fast neutron scattering on Gallium target at 14.8 MeV

    CERN Document Server

    Han, R; Chen, Z; Nie, Y; Liu, X; Zhang, S; Ren, P; Jia, B; Tian, G; Luo, F; Lin, W; Liu, J; Shi, F; Huang, M; Ruan, X; Ren, J; Zhou, Z; Huang, H; Bao, J; Zhang, K; Hu, B

    2014-01-01

    Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

  3. Ion emission in solids bombarded with Au{sub n}{sup +} (n = 1 - 9) clusters accelerated within the 0.15 - 1.25 MeV energy range; Emission ionique des solides a l'impact d'agregats Au{sub n}{sup +} (n=1-9) acceleres entre 0,15 et 1,25 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Wehbe, Nimer [Universite Claude Bernard Lyon-I, 43 boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France)

    2006-06-15

    This experimental work is devoted to the study of the ion emission in solids at the impact of gold clusters of energies within 0.15 to 1.25 MeV range. The physics of ion-solid collisions and the theoretical models of sputtering of solids under ion bombardment are presented in the first chapter. The chapter no. 2 deals with the description of the experimental setup. The study of a gold target allowed to evidence the role of the size and energy of the clusters in determining the emission intensity and the mass distribution of the ions. The 4. chapter gives results from the study of cesium iodide in which the intense emission of CsI clusters could be investigated quantitatively due to multiplicity measurements. Finally, the chapter no. 5 was devoted to the study of a biologic molecule, the phenylalanine, and of a pesticide molecule, chlorosulfuron. This work evidenced the importance of clusters for surface analyses by mass spectrometry.

  4. Characterization of a mitochondrially targeted single-stranded DNA-binding protein in Arabidopsis thaliana.

    Science.gov (United States)

    Edmondson, Andrew C; Song, Daqing; Alvarez, Luis A; Wall, Melisa K; Almond, David; McClellan, David A; Maxwell, Anthony; Nielsen, Brent L

    2005-04-01

    A gene encoding a predicted mitochondrially targeted single-stranded DNA binding protein (mtSSB) was identified in the Arabidopsis thaliana genome sequence. This gene (At4g11060) codes for a protein of 201 amino acids, including a 28-residue putative mitochondrial targeting transit peptide. Protein sequence alignment shows high similarity between the mtSSB protein and single-stranded DNA binding proteins (SSB) from bacteria, including residues conserved for SSB function. Phylogenetic analysis indicates a close relationship between this protein and other mitochondrially targeted SSB proteins. The predicted targeting sequence was fused with the GFP coding region, and the organellar localization of the expressed fusion protein was determined. Specific targeting to mitochondria was observed in in-vitro import experiments and by transient expression of a GFP fusion construct in Arabidopsis leaves after microprojectile bombardment. The mature mtSSB coding region was overexpressed in Escherichia coli and the protein was purified for biochemical characterization. The purified protein binds single-stranded, but not double-stranded, DNA. MtSSB stimulates the homologous strand-exchange activity of E. coli RecA. These results indicate that mtSSB is a functional homologue of the E. coli SSB, and that it may play a role in mitochondrial DNA recombination.

  5. Cyclotron production of {sup 61}Cu using natural Zn and enriched {sup 64}Zn targets

    Energy Technology Data Exchange (ETDEWEB)

    Asad, A. H.; Smith, S. V.; Chan, S.; Jeffery, C. M.; Morandeau, L.; Price, R. I. [RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Australia, Imaging and Applied Physics, Curtin University, Perth, Australia, and Center of Excellence in Anti-matter Matter Studies, Australian National University, Can (Australia); Brookhaven National Laboratory, Upton, NY (United States) and Center of Excellence in Anti-matter Matter Studies, Australian National University, Canberra (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); Center of Excellence in Anti-matter Matter Studies, Australian National University, Canberra, Australia, and Chemistry, University of Western Australia, Pe (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Australia and Physics, University of Western Australia, Perth (Australia)

    2012-12-19

    Copper-61 ({sup 61}Cu) shares with {sup 64}Cu certain advantages for PET diagnostic imaging, but has a shorter half-life (3.4hr vs. 12.7hr) and a greater probability of positron production per disintegration (61% vs. 17.9%). One important application is for in vivo imaging of hypoxic tissue. In this study {sup 61}Cu was produced using the {sup 64}Zn(p,{alpha}){sup 61}Cu reaction on natural Zn or enriched {sup 64}Zn targets. The enriched {sup 64}Zn (99.82%) was electroplated onto high purity gold or silver foils or onto thin Al discs. A typical target bombardment used 30{mu}A; at 11.7, 14.5 or 17.6MeV over 30-60min. The {sup 61}Cu (radiochemical purity of >95%) was separated using a combination of cation and anion exchange columns. The {sup 64}Zn target material was recovered after each run, for re-use. In a direct comparison with enriched {sup 64}Zn-target results, {sup 61}Cu production using the cheaper {sup nat}Zn target proved to be an effective alternative.

  6. Hydrogen and helium recycling from a JxB-force convected liquid metal Ga{sub 67}In{sub 20.5}Sn{sub 12.5} under steady state plasma bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Hirooka, Yoshi, E-mail: hirooka.yoshihiko@nifs.ac.jp [National institute for Fusion Science, Oroshi, Toki, Gifu 509-5292 (Japan); Graduate University for Advanced Studies, Oroshi, Toki, Gifu 509-5292 (Japan); Bi, Hailin [Graduate University for Advanced Studies, Oroshi, Toki, Gifu 509-5292 (Japan); Shimada, Michiya [Japan Atomic Energy Agency, Rokkasho, Kamikita, Aomori 039-3212 (Japan); Ono, Masa [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States)

    2017-04-15

    A series of first-of-a-kind laboratory-scale experiments on the JxB-force convected liquid metal divertor concept have been carried out in the temperature range from room temperature to ∼200 °C, employing a eutectic alloy: Ga{sub 67}In{sub 20.5}Sn{sub 12.5}, the melting point of which is 10.5 °C. The electrical current conducted through the alloy is set at about 70A and the magnetic field is set at about 700 G. It has reproducibly been observed that hydrogen as well as helium particle recycling is noticeably reduced under steady state plasma bombardment when the liquid is convected by the JxB force.

  7. Neutron production in a thick target by means of a high energy proton beam; Production de neutrons en cible epaisse par un faisceau de protons de haute energie

    Energy Technology Data Exchange (ETDEWEB)

    Menard, S

    1998-01-06

    The energy and angular distributions of neutrons produced by bombarding thick targets with protons from 0.8 GeV up to 1.6 GeV have been measured at the Saturne synchrotron facility using time-of-flight technique. Measurements using targets of various lengths (40, 65 and 105 cm), various diameters (10 and 20 cm (lead, iron), 15 cm (tungsten)) and several compositions (iron, lead, tungsten) are discussed. These experimental data are compared with theoretical simulations carried out using the TIERCE code. The neutron spectra calculated by using TIERCE systematically underestimate the measured distributions. A simple model has been developed to calculate energy distributions and multiplicities of the neutrons emitted in the interaction of a high-energy proton beam with a thick target. The predictions of this model are compared with experimental data. (author) 72 refs.

  8. Targeted therapies for cancer

    Science.gov (United States)

    ... so they cannot spread. How Does Targeted Therapy Work? Targeted therapy drugs work in a few different ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  9. Reflectance Reference Targets (OTTER)

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Spectral reflectance measurements of flat field targets as reference points representative of pseudo-invariant targets as measured by Spectron SE590...

  10. Reflectance Reference Targets (OTTER)

    Data.gov (United States)

    National Aeronautics and Space Administration — Spectral reflectance measurements of flat field targets as reference points representative of pseudo-invariant targets as measured by Spectron SE590 spectrophotometer

  11. Intense ${^31-35}$Ar beams produced with a nanostructured CaO target at ISOLDE

    CERN Document Server

    Ramos, J P; Mendonça, T M; Seiffert, C; Senos, A M R; Fynbo, H O U; Tengblad, O; Briz, J A; Lund, M V; Koldste, G T; Carmona-Gallardo, M; Pesudo, V; Stora, T

    2014-01-01

    At the ISOLDE facility at CERN, thick targets are bombarded with highly energetic pulsed protons to produce radioactive ion beams (RIBs). The isotopes produced in the bulk of the material have to diffuse out of the grain and effuse throughout the porosity of the material to a transfer line which is connected to an ionizer, from which the charged isotopes are extracted and delivered for physics experiments. Calcium oxide (CaO) powder targets have been used to produce mainly neutron deficient argon and carbon RIBs over the past decades. Such targets presented unstable yields, either decaying over time or low from the beginning of operation. These problems were suspected to come from the degradation of the target microstructure (sintering due to high temperature and/or high proton intensity). In this work, a CaO microstructural study in terms of sintering was conducted on a nanostructured CaO powder synthesized from the respective carbonate. Taking the results of this study, several changes were made at ISOLDE i...

  12. Thick target yields of proton induced gamma-ray emission from Al, Si and P

    Energy Technology Data Exchange (ETDEWEB)

    Jokar, A., E-mail: arezajokar@gmail.com; Kakuee, O.; Lamehi-Rachti, M.; Fathollahi, V.

    2017-03-01

    Thick target excitation yield curves of gamma-rays from the reactions {sup 27}Al(p,p′γ){sup 27}Al (E{sub γ} = 844 and 1014 keV), {sup 27}Al(p,αγ){sup 27}Al (E{sub γ} = 1369 keV), {sup 28}Si(p,p′γ){sup 28}Si (E{sub γ} = 1779 keV), {sup 29}Si(p,p′γ){sup 29}Si (E{sub γ} = 1273 keV) and {sup 31}P(p,p′γ){sup 31}P (E{sub γ} = 1266 keV) were measured by bombarding pure-element targets with protons at energies below 3 MeV. Gamma-rays were detected with a High Purity Ge detector placed at an angle of 90° with respect to the beam direction. The obtained thick target gamma-ray yields were compared with the previously published data. The overall systematic uncertainty of the thick target yield values was estimated to be better than ±9%.

  13. Target irradiation facility and targetry development at 160 MeV proton beam of Moscow linac

    CERN Document Server

    Zhuikov, B L; Konyakhin, N A; Vincent, J

    1999-01-01

    A facility has been built and successfully operated with the 160 MeV proton beam of Moscow Meson factory LINAC, Institute for Nuclear Research (INR) of Russian Academy of Science, Troitsk. The facility was created for various isotope production goals as well as for fundamental nuclear investigations at high intensity beam (100 mu A and more). An important part of the facility targetry system is a high-intensity beam monitoring collimator device. Measurements of the temperature distribution between collimator sectors, cooling water flow and temperature, and the beam current, provide an opportunity to compute beam losses and beam position. The target holder design allows easy insertion by manipulator and simultaneous bombardment of several different targets of various types and forms, and variation of proton energy on each target over a wide range below 160 MeV. The main target utilized for commercial sup 8 sup 2 Sr isotope production is metallic rubidium in a stainless-steel container. A regular wet chemistry ...

  14. X-point target divertor concept and the Alcator DX high power divertor test facility

    Science.gov (United States)

    Labombard, B.; Marmar, E.; Irby, J.; Vieria, R.; Wolfe, S.; Bonoli, P.; Fiore, C.; Granetz, R.; Greenwald, M.; Hutchinson, I.; Hubbard, A.; Hughes, J.; Lin, Y.; Lipschultz, B.; Parker, R.; Porkolab, M.; Reinke, M.; Rice, J.; Shiraiwa, S.; Terry, J.; Theiler, C.; Wallace, G.; White, A.; Whyte, D.; Wukitch, S.

    2013-10-01

    Three critical challenges must be met before a steady-state, power-producing fusion reactor can be realized: (1) safely handle extreme plasma exhaust power, (2) completely suppress material erosion at divertor targets and (3) do this while maintaining a burning plasma core. Advanced divertors such as `Super X' and `X-point target' have the potential to solve all three challenges by producing a stable, fully detached, low temperature plasma in the divertor while maintaining a hot boundary layer around a clean plasma core. The X-point target divertor may be particularly effective. It places a second X-point in the pathway of the peak parallel heat flux with the intention of forming an X-point MARFE in the divertor volume, well away from the primary X-point that defines the last closed flux surface and at larger major radius, providing detachment front stability. Divertor heat dissipation is via volumetric processes (radiation, ion-neutral collisions), virtually eliminating erosion by ion bombardment and reducing peak heat flux and neutron fluence on remote divertor target components. Alcator DX is conceived as a national facility to test these ideas. It employs the high magnetic field technology of Alcator combined with high-power ICRH to investigate advanced divertors at reactor-level parallel heat flux densities.

  15. Targets for Precision Measurements

    Science.gov (United States)

    Loveland, W.; Yao, L.; Asner, D. M.; Baker, R. G.; Bundgaard, J.; Burgett, E.; Cunningham, M.; Deaven, J.; Duke, D. L.; Greife, U.; Grimes, S.; Heffner, M.; Hill, T.; Isenhower, D.; Klay, J. L.; Kleinrath, V.; Kornilov, N.; Laptev, A. B.; Massey, T. N.; Meharchand, R.; Qu, H.; Ruz, J.; Sangiorgio, S.; Selhan, B.; Snyder, L.; Stave, S.; Tatishvili, G.; Thornton, R. T.; Tovesson, F.; Towell, D.; Towell, R. S.; Watson, S.; Wendt, B.; Wood, L.

    2014-05-01

    The general properties needed in targets (sources) for high precision, high accuracy measurements are reviewed. The application of these principles to the problem of developing targets for the Fission TPC is described. Longer term issues, such as the availability of actinide materials, improved knowledge of energy losses and straggling and the stability of targets during irradiation are also discussed.

  16. Setting Asset Performance Targets

    NARCIS (Netherlands)

    Green, D.; Hodkiewicz, M.; Masschelein, S.; Schoenmaker, R.; Muruvan, S.

    2015-01-01

    Setting targets is a common way for organisations to establish performance expectations. However the validity of targets is challenged when performance is influenced by factors beyond the control of the manager. This project examines the issue of target setting for a single asset performance measure

  17. Development of distributed target

    CERN Document Server

    Yu Hai Jun; Li Qin; Zhou Fu Xin; Shi Jin Shui; Ma Bing; Chen Nan; Jing Xiao Bing

    2002-01-01

    Linear introduction accelerator is expected to generate small diameter X-ray spots with high intensity. The interaction of the electron beam with plasmas generated at the X-ray converter will make the spot on target increase with time and debase the X-ray dose and the imaging resolving power. A distributed target is developed which has about 24 pieces of thin 0.05 mm tantalum films distributed over 1 cm. due to the structure adoption, the distributed target material over a large volume decreases the energy deposition per unit volume and hence reduces the temperature of target surface, then reduces the initial plasma formalizing and its expansion velocity. The comparison and analysis with two kinds of target structures are presented using numerical calculation and experiments, the results show the X-ray dose and normalized angle distribution of the two is basically the same, while the surface of the distributed target is not destroyed like the previous block target

  18. Measurement of the $^{7}$Be$(p,\\gamma)^{8}$B Cross-Section with an Implanted Target

    CERN Multimedia

    2002-01-01

    % IS366\\\\ \\\\ The $^7$Be(p,$\\gamma)^8$B capture reaction is of major importance to the physics of the sun and the issues of the ``solar neutrino puzzle'' and neutrino masses. We report here on a new determination of the absolute cross section of this reaction, using a novel method which overcomes some of the major experimental uncertainties of previous measurements. We utilize an implanted $^7$Be target and a uniformly scanned particle beam larger than the target spot, eliminating issues of target homogeneity and backscattering loss of $^8$B reaction products. The target was produced using a beam of 1.8 10$^{10}$/s $^7$Be nuclei extracted at ISOLDE(CERN) from a graphite target bombarded by 1 GeV protons in a two-step resonant laser ionization source. The $^7$Be nuclei were directly implanted into a copper substrate to obtain a target of 2 mm diameter with a total of 3.10$^{15}$ atoms. The measurement of the $^8$B production cross section was carried out at the Van de Graaff laboratory of the Weizmann Institute...

  19. Cross sections for the formation of radioiodines in proton bombardment of natural tellerium with particular reference to the validation of data for the production of {sup 123}I

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, A.M.; Hassan, K.F.; Saleh, Z.A. [Atomic Energy Authority, Cairo (Egypt). Cyclotron Facility; Hassan, H.E. [Atomic Energy Authority, Cairo (Egypt). Cyclotron Facility; Taif Univ., Hawiya (Saudi Arabia). Physics Dept.; Khalaf, A.M. [Al-Azhar Univ., Cairo (Egypt). Physics Dept.

    2011-07-01

    The excitation functions of proton induced nuclear reactions on {sup nat}Te were measured using the stacked-foil technique up to 14.5 MeV. Samples of thin uniform layers of {sup nat}Te on Ti-backing were prepared by electro-deposition. Nuclear reaction cross sections for the formation of {sup 120g,121,123,124,125,126,128,130(m+g)}I were determined and their theoretical thick target yields were calculated. The obtained data were compared with the previously published experimental results and the values obtained theoretically using the ALICE-IPPE computer code. (orig.)

  20. High-power liquid-lithium jet target for neutron production.

    Science.gov (United States)

    Halfon, S; Arenshtam, A; Kijel, D; Paul, M; Berkovits, D; Eliyahu, I; Feinberg, G; Friedman, M; Hazenshprung, N; Mardor, I; Nagler, A; Shimel, G; Tessler, M; Silverman, I

    2013-12-01

    A compact liquid-lithium target (LiLiT) was built and tested with a high-power electron gun at the Soreq Nuclear Research Center. The lithium target, to be bombarded by the high-intensity proton beam of the Soreq Applied Research Accelerator Facility (SARAF), will constitute an intense source of neutrons produced by the (7)Li(p,n)(7)Be reaction for nuclear astrophysics research and as a pilot setup for accelerator-based Boron Neutron Capture Therapy. The liquid-lithium jet target acts both as neutron-producing target and beam dump by removing the beam thermal power (>5 kW, >1 MW/cm(3)) with fast transport. The target was designed based on a thermal model, accompanied by a detailed calculation of the (7)Li(p,n) neutron yield, energy distribution, and angular distribution. Liquid lithium is circulated through the target loop at ~200 °C and generates a stable 1.5 mm-thick film flowing at a velocity up to 7 m/s onto a concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power areal densities of >4 kW/cm(2) and volume power density of ~2 MW/cm(3) at a lithium flow of ~4 m/s while maintaining stable temperature and vacuum conditions. The LiLiT setup is presently in online commissioning stage for high-intensity proton beam irradiation (1.91-2.5 MeV, 1-2 mA) at SARAF.

  1. High-power liquid-lithium jet target for neutron production

    Energy Technology Data Exchange (ETDEWEB)

    Halfon, S.; Feinberg, G. [Soreq NRC, Yavne 81800 (Israel); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Arenshtam, A.; Kijel, D.; Berkovits, D.; Eliyahu, I.; Hazenshprung, N.; Mardor, I.; Nagler, A.; Shimel, G.; Silverman, I. [Soreq NRC, Yavne 81800 (Israel); Paul, M.; Friedman, M.; Tessler, M. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

    2013-12-15

    A compact liquid-lithium target (LiLiT) was built and tested with a high-power electron gun at the Soreq Nuclear Research Center. The lithium target, to be bombarded by the high-intensity proton beam of the Soreq Applied Research Accelerator Facility (SARAF), will constitute an intense source of neutrons produced by the {sup 7}Li(p,n){sup 7}Be reaction for nuclear astrophysics research and as a pilot setup for accelerator-based Boron Neutron Capture Therapy. The liquid-lithium jet target acts both as neutron-producing target and beam dump by removing the beam thermal power (>5 kW, >1 MW/cm{sup 3}) with fast transport. The target was designed based on a thermal model, accompanied by a detailed calculation of the {sup 7}Li(p,n) neutron yield, energy distribution, and angular distribution. Liquid lithium is circulated through the target loop at ∼200 °C and generates a stable 1.5 mm-thick film flowing at a velocity up to 7 m/s onto a concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power areal densities of >4 kW/cm{sup 2} and volume power density of ∼2 MW/cm{sup 3} at a lithium flow of ∼4 m/s while maintaining stable temperature and vacuum conditions. The LiLiT setup is presently in online commissioning stage for high-intensity proton beam irradiation (1.91–2.5 MeV, 1–2 mA) at SARAF.

  2. Thick target double differential neutron energy distribution from {sup 12}C+ {sup 27}Al at 115 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Suman, V. [Health Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sunil, C., E-mail: csunil11@gmail.com [Health Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Nair, Soumya; Paul, S.; Biju, K.; Sahoo, G.S. [Health Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sarkar, P.K. [Manipal Centre for Natural Sciences, Manipal University, Manipal 576104 (India)

    2015-11-11

    Neutron yield from 115 MeV {sup 12}C projectiles bombarding a thick {sup 27}Al target has been measured using the time of flight technique. Nuclear reaction model code PACE and the FLUKA Monte Carlo code are used to calculate the yield and the results are compared with the experimental data. The energy for maximum neutron emission in experimental measurement and reaction code output has a slight disagreement in the extreme forward emission angle but in all other angles it has a close match. The slope of the distribution in general shows good match between the experimental and the reaction code results as well as FLUKA calculations. The maximum energy of the emitted neutrons is observed to decrease with the increasing emission angles.

  3. Inertial Confinement fusion targets

    Science.gov (United States)

    Hendricks, C. D.

    1982-01-01

    Inertial confinement fusion (ICF) targets are made as simple flat discs, as hollow shells or as complicated multilayer structures. Many techniques were devised for producing the targets. Glass and metal shells are made by using drop and bubble techniques. Solid hydrogen shells are also produced by adapting old methods to the solution of modern problems. Some of these techniques, problems, and solutions are discussed. In addition, the applications of many of the techniques to fabrication of ICF targets is presented.

  4. Target Window Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-11

    The target window design implemented and tested in experiments at ANL have performed without failure for the available beam of 6 mm FWHM on a 12 mm diameter target. However, scaling that design to a 25 mm diameter target size for a 12 mm FWHM beam has proven problematic. Combined thermal and mechanical (pressure induced) stresses and strains are too high to maintain the small coolant gaps and provide adequate fatigue lifetime.

  5. The ISOLDE target robots

    CERN Multimedia

    Maximilein Brice

    2002-01-01

    ISOLDE targets need to be changed frequently, around 80 times per year. The high radiation levels do not permit this to be done by human hands and the target changes are effected by 2 industrial robots (picture _01). On the left, in the distance, the front-end of the GPS (General Purpose Separator) is seen, while the HRS (High Resolution Separator) is at the right. Also seen are the doors to the irradiated-target storage.

  6. Targeting the tumor microenvironment

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, P.A.; Lee, G.Y.; Bissell, M.J.

    2006-11-07

    Despite some notable successes cancer remains, for the most part, a seemingly intractable problem. There is, however, a growing appreciation that targeting the tumor epithelium in isolation is not sufficient as there is an intricate mutually sustaining synergy between the tumor epithelial cells and their surrounding stroma. As the details of this dialogue emerge, new therapeutic targets have been proposed. The FDA has already approved drugs targeting microenvironmental components such as VEGF and aromatase and many more agents are in the pipeline. In this article, we describe some of the 'druggable' targets and processes within the tumor microenvironment and review the approaches being taken to disrupt these interactions.

  7. Target Assembly Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Target Assembly Facility integrates new armor concepts into actual armored vehicles. Featuring the capability ofmachining and cutting radioactive materials, it...

  8. Transparent conducting ZnO-Based thin films deposited by magnetron sputtering of a ZnO:Ga-C composite target

    Science.gov (United States)

    Abduev, A. Kh.; Akhmedov, A. K.; Asvarov, A. Sh.

    2014-07-01

    We have studied the structure, electrical, and optical properties of thin transparent conducting films based on gallium-doped zinc oxide (ZnO:Ga), which were deposited by magnetron sputtering of a ZnO:Ga-C composite target. The ion-bombardment-induced interaction of ZnO with carbon in a thin surface layer of the target leads to an increase in the excess zinc content in the reagent flow. The formation of transparent conducting ZnO:Ga films at a substrate temperature above 100°C in the presence of excess zinc near the growth surface leads to improvement in the structure and conductivity of films without decreasing their transmission in the visible spectral range.

  9. Target visibility for multiple maneuvering target tracking

    Science.gov (United States)

    Sabordo, Madeleine G.; Aboutanios, Elias

    2015-05-01

    We present a recursion of the probability of target visibility and its applications to analysis of track life and termination in the context of Global Nearest Neighbour (GNN) approach and Probability Hypothesis Density (PHD) filter. In the presence of uncertainties brought about by clutter; decisions to retain a track, terminate it or initialise a new track are based on probability, rather than on distance criterion or estimation error. The visibility concept is introduced into a conventional data-association-oriented multitarget tracker, the GNN; and a random finite set based-tracker, the PHD filter, to take into account instances when targets become invisible or occluded by obstacles. We employ the natural logarithmof the Dynamic Error Spectrum to assess the performance of the trackers with and without probability of visibility incorporated. Simulation results show that the performance of the GNN tracker with visibility concept incorporated is significantly enhanced.

  10. Frozen spin targets

    CERN Document Server

    Parsons, A S L

    1976-01-01

    Describes six projects which use the frozen-spin principle: Helium-3 R.M.S. and longitudinally polarized frozen spin targets at Rutherford Laboratory, and the frozen spin targets at KEK, Saclay and the one used by the CERN-Helsinki collaboration. (7 refs).

  11. Seedling root targets

    Science.gov (United States)

    Diane L. Haase

    2011-01-01

    Roots are critical to seedling performance after outplanting. Although root quality is not as quick and simple to measure as shoot quality, target root characteristics should be included in any seedling quality assessment program. This paper provides a brief review of root characteristics most commonly targeted for operational seedling production. These are: root mass...

  12. Strategic Targeted Advertising

    NARCIS (Netherlands)

    A. Galeotti; J.L. Moraga-Gonzalez (José Luis)

    2003-01-01

    textabstractWe present a strategic game of pricing and targeted-advertising. Firms can simultaneously target price advertisements to different groups of customers, or to the entire market. Pure strategy equilibria do not exist and thus market segmentation cannot occur surely. Equilibria exhibit

  13. Segmented Target Design

    Science.gov (United States)

    Merhi, Abdul Rahman; Frank, Nathan; Gueye, Paul; Thoennessen, Michael; MoNA Collaboration

    2013-10-01

    A proposed segmented target would improve decay energy measurements of neutron-unbound nuclei. Experiments like this have been performed at the National Superconducting Cyclotron Laboratory (NSCL) located at Michigan State University. Many different nuclei are produced in such experiments, some of which immediately decay into a charged particle and neutron. The charged particles are bent by a large magnet and measured by a suite of charged particle detectors. The neutrons are measured by the Modular Neutron Array (MoNA) and Large Multi-Institutional Scintillation Array (LISA). With the current target setup, a nucleus in a neutron-unbound state is produced with a radioactive beam impinged upon a beryllium target. The resolution of these measurements is very dependent on the target thickness since the nuclear interaction point is unknown. In a segmented target using alternating layers of silicon detectors and Be-targets, the Be-target in which the nuclear reaction takes place would be determined. Thus the experimental resolution would improve. This poster will describe the improvement over the current target along with the status of the design. Work supported by Augustana College and the National Science Foundation grant #0969173.

  14. The CNGS target

    CERN Multimedia

    Patrice Loïez

    2005-01-01

    The CERN Neutrinos to Gran Sasso (CNGS) target ‘magazine’ of five target units. Each unit contains a series of 10-cm long graphite rods distributed over a length of 2 m. It is designed to maximize the number of secondary particles produced and hence the number of neutrinos. One unit is used at a time to prevent over heating.

  15. Targeted therapy in lymphoma

    Directory of Open Access Journals (Sweden)

    Cavalli Franco

    2010-11-01

    Full Text Available Abstract Discovery of new treatments for lymphoma that prolong survival and are less toxic than currently available agents represents an urgent unmet need. We now have a better understanding of the molecular pathogenesis of lymphoma, such as aberrant signal transduction pathways, which have led to the discovery and development of targeted therapeutics. The ubiquitin-proteasome and the Akt/mammalian target of rapamycin (mTOR pathways are examples of pathological mechanisms that are being targeted in drug development efforts. Bortezomib (a small molecule protease inhibitor and the mTOR inhibitors temsirolimus, everolimus, and ridaforolimus are some of the targeted therapies currently being studied in the treatment of aggressive, relapsed/refractory lymphoma. This review will discuss the rationale for and summarize the reported findings of initial and ongoing investigations of mTOR inhibitors and other small molecule targeted therapies in the treatment of lymphoma.

  16. Targets and teamwork

    DEFF Research Database (Denmark)

    Skinner, Timothy C; Lange, Karin S; Hoey, Hilary

    2017-01-01

    with less disagreement about recommended targets. Multiple regression analysis indicated that teams reporting higher HbA1c targets and more target disagreement had parents reporting higher treatment targets. This seemed to partially account for center differences in Hb1Ac. Conclusions: The diabetes care....... Research Design and Methods: Children, under the age of 11 with type 1 diabetes and their parents treated at the study centers participated. Clinical, medical, and demographic data were obtained, along with blood sample for centralized assay. Parents and all members of the diabetes care team completed...... questionnaires on treatment targets for hemoglobin A1c (HbA1c) and recommended frequency of blood glucose monitoring. Results: Totally 1113 (53% male) children (mean age 8.0±2.1years) from 18 centers in 17 countries, along with parents and 113 health-care professionals, participated. There were substantial...

  17. Self-terminated etching of GaN with a high selectivity over AlGaN under inductively coupled Cl2/N2/O2 plasma with a low-energy ion bombardment

    Science.gov (United States)

    Zhong, Yaozong; Zhou, Yu; Gao, Hongwei; Dai, Shujun; He, Junlei; Feng, Meixin; Sun, Qian; Zhang, Jijun; Zhao, Yanfei; DingSun, An; Yang, Hui

    2017-10-01

    Etching of GaN/AlGaN heterostructure by O-containing inductively coupled Cl2/N2 plasma with a low-energy ion bombardment can be self-terminated at the surface of the AlGaN layer. The estimated etching rates of GaN and AlGaN were 42 and 0.6 nm/min, respectively, giving a selective etching ratio of 70:1. To study the mechanism of the etching self-termination, detailed characterization and analyses were carried out, including X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS). It was found that in the presence of oxygen, the top surface of the AlGaN layer was converted into a thin film of (Al,Ga)Ox with a high bonding energy, which effectively prevented the underlying atoms from a further etching, resulting in a nearly self-terminated etching. This technique enables a uniform and reproducible fabrication process for enhancement-mode high electron mobility transistors with a p-GaN gate.

  18. Metabolism of 15-(4'-[123I]iodophenyl)pentadecanoic acid ([123I]IPPA) in the rat heart; identification of new metabolites by high pressure liquid chromatography and fast atom bombardment-mass spectrometry.

    Science.gov (United States)

    Eisenhut, M; Lehmann, W D; Sütterle, A

    1993-08-01

    The metabolism of 15-(4'-iodophenyl)pentadecanoic acid (IPPA) in the heart muscle is commonly believed to end at 4-iodobenzoic acid as the main and final product of beta-oxidation. However, investigation of the metabolic fate of IPPA in Langendorff rat hearts using high pressure liquid chromatography (HPLC) and negative fast atom bombardment mass spectrometry (FAB-MS) revealed new results. After perfusing isolated rat hearts with [123I]IPPA, metabolites were monitored by HPLC using simultaneous detection of gamma-radioactivity and u.v. absorbance. The identification of HPLC separated metabolites was based on their nominal molecular weights as determined by negative FAB-MS. According to these measurements five catabolites were identified with decreasing concentration: 3-(4'-iodophenyl)propanoic acid > 3-(4'-iodophenyl)propanoic acid = 5-(4'-iodophenyl)-3-hydroxypentanoic acid > 4-iodobenzoic acid. Additionally, an anabolic metabolite was found exclusively in the lipid ester fraction. From the hydrolysed heart lipids this compound was identified as 11-(4'-iodophenyl)undecanoic acid. Its formation is explained by the action of cytosolic fatty acid synthetase on IPPA catabolites. This metabolic behaviour may be of importance for the interpretation of sequential heart scintigraphy performed with [123I]IPPA.

  19. Damage of niobium surfaces caused by bombardment with /sup 4/He/sup +/ ions of different energies typical for T-20

    Energy Technology Data Exchange (ETDEWEB)

    Guseva, M.I.; Gusev, V.; Martynenko, Yu.V.; Das, S.K.; Kaminsky, N.

    1979-01-01

    The surface damage of cold worked and annealed polycrystalline Nb irradiated at room temperature with He/sup +/ ions sequentially at different energies over the range from 0.5 keV to 1.8 MeV has been investigated. The individual energy and the dose of the He/sup +/ ion was chosen to match the theoretically calculated He/sup +/ ion spectrum expected in the Tokamak T-20. In one set of irradiations, targets were irradiated at Kurchatov Institute starting with 0.5 keV /sup 4/He/sup +/ ions and extending up to 90 keV in eleven steps. Subsequently, the same area was irradiated at ANL starting at 150 keV and increased in eight steps up to 1.8 MeV. The irradiations were carried out for a total dose of 5.0 C/cm/sup 2/. In another set of irradiations the sequence was reversed. Scanning electron microscopy results show formation of blisters and exfoliation. For the same dose the broad energy implant (due to sequential irradiation) appears to decrease the blister diameter and density as compared to irradiation with monoenergetic He/sup +/ ions at a given energy (in the energy range considered). Some estimates of surface erosion yields due to blistering are given.

  20. Heavy-ion induced desorption yields of amorphous carbon films bombarded with 4.2 MeV/u lead ions

    CERN Document Server

    Mahner, E; Küchler, D; Scrivens, R; Costa Pinto, P; Yin Vallgren, C; Bender, M

    2011-01-01

    During the past decade, intense experimental studies on the heavy-ion induced molecular desorption were performed in several particle accelerator laboratories worldwide in order to understand and overcome large dynamic pressure rises caused by lost beam ions. Different target materials and various coatings were studied for desorption and mitigation techniques were applied to heavy-ion accelerators. For the upgrade of the CERN injector complex, a coating of the Super Proton Synchrotron (SPS) vacuum system with a thin film of amorphous carbon is under study to mitigate the electron cloud effect observed during SPS operation with the nominal proton beam for the Large Hadron Collider (LHC). Since the SPS is also part of the heavy-ion injector chain for LHC, dynamic vacuum studies of amorphous carbon films are important to determine their ion induced desorption yields. At the CERN Heavy Ion Accelerator (LINAC 3), carbon-coated accelerator-type stainless steel vacuum chambers were tested for desorption using 4.2 Me...

  1. AA antiproton production target

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    The first version of the antiproton production target was a tungsten rod, 11 cm long and 3 mm in diameter. The rod was embedded in graphite, pressure-seated into an outer casing of stainless steel. At the entrance to the target assembly was a scintillator screen, imprinted with circles every 5 mm in radius, which allowed to precisely aim the 26 GeV high-intensity proton beam from the PS onto the centre of the target rod. The scintillator screen was a 1 mm thick plate of Cr-doped alumina. See also 7903034 and 7905091.

  2. Intense {sup 31–35}Ar beams produced with a nanostructured CaO target at ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, J.P. [CERN, CH-1211 Genève 23 (Switzerland); Department of Materials and Ceramics Engineering, University of Aveiro, CICECO, 3810-193 Aveiro (Portugal); Gottberg, A. [CERN, CH-1211 Genève 23 (Switzerland); Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); Mendonça, T.M. [CERN, CH-1211 Genève 23 (Switzerland); IFIMUP-IN, Institute of Nanosciences and Nanotechnology, University of Porto, 4169-007 Porto (Portugal); Seiffert, C. [CERN, CH-1211 Genève 23 (Switzerland); Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt (Germany); Senos, A.M.R. [Department of Materials and Ceramics Engineering, University of Aveiro, CICECO, 3810-193 Aveiro (Portugal); Fynbo, H.O.U. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Åarhus (Denmark); Tengblad, O.; Briz, J.A. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); Lund, M.V.; Koldste, G.T. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Åarhus (Denmark); Carmona-Gallardo, M.; Pesudo, V. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); Stora, T., E-mail: thierry.stora@cern.ch [CERN, CH-1211 Genève 23 (Switzerland)

    2014-02-01

    Highlights: • A nanometric mesoporous CaO powder was developed and studied in terms of sintering. • For the first time a nanostructured target material was operated at ISOLDE. • Unlike past CaO targets, stable yields over time of n-deficient argon were delivered. • Higher (exotic) Ar yields were obtained at lower temperatures and proton intensities. -- Abstract: At the ISOLDE facility at CERN, thick targets are bombarded with highly energetic pulsed protons to produce radioactive ion beams (RIBs). The isotopes produced in the bulk of the material have to diffuse out of the grain and effuse throughout the porosity of the material to a transfer line which is connected to an ionizer, from which the charged isotopes are extracted and delivered for physics experiments. Calcium oxide (CaO) powder targets have been used to produce mainly neutron deficient argon and carbon RIBs over the past decades. Such targets presented unstable yields, either decaying over time or low from the beginning of operation. These problems were suspected to come from the degradation of the target microstructure (sintering due to high temperature and/or high proton intensity). In this work, a CaO microstructural study in terms of sintering was conducted on a nanostructured CaO powder synthesized from the respective carbonate. Taking the results of this study, several changes were made at ISOLDE in terms of the CaO target production, handling and operation in order to produce and maintain the nanostructured CaO. The new target, the first nanostructured target to be operated at ISOLDE, showed improved yields of (exotic) Ar and more importantly a stable yield over the whole operation time, while operating with lower temperatures. This contradicts the ISOL paradigm of using the highest possible temperature regardless of the target’s microstructure degradation.

  3. Target Price Accuracy

    Directory of Open Access Journals (Sweden)

    Alexander G. Kerl

    2011-04-01

    Full Text Available This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio. However, target price accuracy is positively related to the level of detail of each report, company size and the reputation of the investment bank. The potential conflicts of interests between an analyst and a covered company do not bias forecast accuracy.

  4. Optimal exploration target zones

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-09-01

    Full Text Available This research describes a quantitative methodology for deriving optimal exploration target zones based on a probabilistic mineral prospectivity map. In order to arrive at out objective, we provide a plausible answer to the following question: "Which...

  5. An ISOLDE target unit

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    A good dozen different targets are available for ISOLDE, made of different materials and equipped with different kinds of ion-sources, according to the needs of the experiments. Each separator (GPS: general purpose; HRS: high resolution) has its own target. Because of the high radiation levels, robots effect the target changes, about 80 times per year. In the standard unit shown in picture _01, the target is the cylindrical object in the front. It contains uranium-carbide kept at a temperature of 2200 deg C, necessary for the isotopes to be able to escape. At either end, one sees the heater current leads, carrying 700 A. The Booster beam, some 3E13 protons per pulse, enters the target from left. The evaporated isotope atoms enter a hot-plasma ion source (the black object behind the target). The whole unit sits at 60 kV potential (pulsed in synchronism with the arrival of the Booster beam) which accelerates the ions (away from the viewer) towards one of the 2 separators.

  6. Coupling of morphology to surface transport in ion-beam-irradiated surfaces: normal incidence and rotating targets

    Energy Technology Data Exchange (ETDEWEB)

    Munoz-Garcia, Javier [Grupo Interdisciplinar de Sistemas Complejos (GISC) and School of Mathematical Sciences and Complex and Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); Cuerno, Rodolfo [Departamento de Matematicas and GISC, Universidad Carlos III de Madrid, Avenida de la Universidad 30, E-28911 Leganes (Spain); Castro, Mario [GISC and Grupo de Dinamica No Lineal (DNL), Escuela Tecnica Superior de IngenierIa (ICAI), Universidad Pontificia Comillas de Madrid, E-28015 Madrid (Spain)], E-mail: javiermunozgarcia@gmail.com, E-mail: cuerno@math.uc3m.es, E-mail: mariocastro73@gmail.com

    2009-06-03

    Continuum models have proved their applicability to describe nanopatterns produced by ion-beam sputtering of amorphous or amorphizable targets at low and medium energies. Here we pursue the recently introduced 'hydrodynamic approach' in the cases of bombardment at normal incidence, or of oblique incidence onto rotating targets, known to lead to self-organized arrangements of nanodots. Our approach stresses the dynamical roles of material (defect) transport at the target surface and of local redeposition. By applying results previously derived for arbitrary angles of incidence, we derive effective evolution equations for these geometries of incidence, which are then numerically studied. Moreover, we show that within our model these equations are identical (albeit with different coefficients) in both cases, provided surface tension is isotropic in the target. We thus account for the common dynamics for both types of incidence conditions, namely formation of dots with short-range order and long-wavelength disorder, and an intermediate coarsening of dot features that improves the local order of the patterns. We provide for the first time approximate analytical predictions for the dependence of stationary dot features (amplitude and wavelength) on phenomenological parameters, that improve upon previous linear estimates. Finally, our theoretical results are discussed in terms of experimental data.

  7. Sputtering effect of low-energy ions on biological target: The analysis of sputtering product of urea and capsaicin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lili [Key Laboratory of Ion Beam Bio-Engineering, Institute of Technical Biology and Agriculture Engineering of Chinese Academy of Sciences, Shushanhu Road 350, Hefei 230031 (China); Xu, Xue [Rice Research Institute, Anhui Academy of Agricultural Sciences, Nongke South Road 40, Hefei 230031 (China); Wu, Yuejin, E-mail: yjwu@ipp.ac.cn [Key Laboratory of Ion Beam Bio-Engineering, Institute of Technical Biology and Agriculture Engineering of Chinese Academy of Sciences, Shushanhu Road 350, Hefei 230031 (China)

    2013-08-01

    Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. Recent years, ion implantation was successfully applied to biological research based on the fragments sputtering and form open paths in cell structure caused by ion sputtering. In this study, we focused on urea and chilli pepper pericarp samples implanted with N{sup +} and Ar{sup +} ions. To investigate the sputtering effect, we designed a collecting unit containing a disk sample and a glass pipe. The urea content and capsaicin content recovered from glass pipes were adopted to represent the sputtering product. The result of urea showed that the sputtering effect is positively correlated with the ion energy and dose, also affected by the ion type. The result of capsaicin was different from that of urea at 20 keV and possibly due to biological complex composition and structure. Therefore the sputtering yield depended on both the parameters of incident ions and the state of target materials. The sputtering yield of urea was also simulated by computational method achieved through the TRIM program. The trajectories of primary and recoiled atoms were calculated on the basis of the binary collision approximation using Monte Carlo method. The experimental results were much higher than the calculated results. The possible explanation is that in the physical model the target were assumed as a disordered lattice and independent atoms, which is much less complicated than that of the biological models.

  8. RF magnetron sputtering of a hydroxyapatite target: A comparison study on polytetrafluorethylene and titanium substrates

    Science.gov (United States)

    Surmenev, Roman A.; Surmeneva, Maria A.; Grubova, Irina Yu.; Chernozem, Roman V.; Krause, Bärbel; Baumbach, Tilo; Loza, Kateryna; Epple, Matthias

    2017-08-01

    A pure hydroxyapatite (HA) target was used to prepare the biocompatible coating of HA on the surface of a polytetrafluorethylene (PTFE) substrate, which was placed on the same substrate holder with technically pure titanium (Ti) in the single deposition runs by radio-frequency (RF) magnetron sputtering. The XPS, XRD and FTIR analyses of the obtained surfaces showed that for all substrates, instead of the HA coating deposition, the coating of a mixture of calcium carbonate and calcium fluoride was grown. According to SEM investigations, the surface of PTFE was etched, and the surface topography of uncoated Ti was preserved after the depositions. The FTIR results reveal no phosphate bonds; only calcium tracks were observed in the EDX-spectra on the surface of the coated PTFE substrates. Phosphate oxide (V), which originated from the target, could be removed using a vacuum pump system, or no phosphate-containing bonds could be formed on the substrate surface because of the severe substrate bombardment process, which prevented the HA coating deposition. The observed results may be connected with the surface re-sputtering effect of the growing film by high-energy negatively charged ions (most probably oxygen or fluorine), which are accelerated in the cathode dark sheath.

  9. Burglar Target Selection

    Science.gov (United States)

    Townsley, Michael; Bernasco, Wim; Ruiter, Stijn; Johnson, Shane D.; White, Gentry; Baum, Scott

    2015-01-01

    Objectives: This study builds on research undertaken by Bernasco and Nieuwbeerta and explores the generalizability of a theoretically derived offender target selection model in three cross-national study regions. Methods: Taking a discrete spatial choice approach, we estimate the impact of both environment- and offender-level factors on residential burglary placement in the Netherlands, the United Kingdom, and Australia. Combining cleared burglary data from all study regions in a single statistical model, we make statistical comparisons between environments. Results: In all three study regions, the likelihood an offender selects an area for burglary is positively influenced by proximity to their home, the proportion of easily accessible targets, and the total number of targets available. Furthermore, in two of the three study regions, juvenile offenders under the legal driving age are significantly more influenced by target proximity than adult offenders. Post hoc tests indicate the magnitudes of these impacts vary significantly between study regions. Conclusions: While burglary target selection strategies are consistent with opportunity-based explanations of offending, the impact of environmental context is significant. As such, the approach undertaken in combining observations from multiple study regions may aid criminology scholars in assessing the generalizability of observed findings across multiple environments. PMID:25866418

  10. The Sinuous Target

    Energy Technology Data Exchange (ETDEWEB)

    Zwaska, R. [Fermilab

    2015-06-01

    We report on the concept for a target material comprised of a multitude of interlaced wires of small dimension. This target material concept is primarily directed at high-power neutrino targets where the thermal shock is large due to small beam sizes and short durations; it also has applications to other high-power targets, particularly where the energy deposition is great or a high surface area is preferred. This approach ameliorates the problem of thermal shock by engineering a material with high strength on the micro-scale, but a very low modulus of elasticity on the meso-scale. The low modulus of elasticity is achieved by constructing the material of spring-like wire segments much smaller than the beam dimension. The intrinsic bends of the wires will allow them to absorb the strain of thermal shock with minimal stress. Furthermore, the interlaced nature of the wires provides containment of any segment that might become loose. We will discuss the progress on studies of analogue materials and fabrication techniques for sinuous target materials.

  11. Setting reference targets

    Energy Technology Data Exchange (ETDEWEB)

    Ruland, R.E.

    1997-04-01

    Reference Targets are used to represent virtual quantities like the magnetic axis of a magnet or the definition of a coordinate system. To explain the function of reference targets in the sequence of the alignment process, this paper will first briefly discuss the geometry of the trajectory design space and of the surveying space, then continue with an overview of a typical alignment process. This is followed by a discussion on magnet fiducialization. While the magnetic measurement methods to determine the magnetic centerline are only listed (they will be discussed in detail in a subsequent talk), emphasis is given to the optical/mechanical methods and to the task of transferring the centerline position to reference targets.

  12. Targeted Therapy of CLL.

    Science.gov (United States)

    Al-Sawaf, Othman; Fischer, Kirsten; Eichhorst, Barbara; Hallek, Michael

    2016-01-01

    The landscape of chronic lymphocytic leukemia (CLL) has undergone profound changes in the past years. First, the addition of CD20-targeting antibodies to conventional chemotherapy has improved the therapeutic outcome in the majority of CLL patients. Since the establishment of the critical role of the B cell receptor signaling pathway in the pathogenesis of CLL, several agents have been developed to target this pathway. Ibrutinib and idelalisib, 2 potent kinase inhibitors, have both become available for CLL therapy in the first and second line. Additionally, the observation of high expression levels of the anti-apoptotic mitochondrial protein Bcl-2 in CLL has led to the development of venetoclax, a BH3 mimetic compound that inhibits Bcl-2 and has shown high efficacy in CLL. This short review summarizes preclinical and clinical data on currently available agents in CLL and provides an outlook on upcoming new challenges in the targeted therapy of CLL. © 2016 S. Karger GmbH, Freiburg.

  13. Modelling Recycling Targets

    DEFF Research Database (Denmark)

    Hill, Amanda Louise; Leinikka Dall, Ole; Andersen, Frits M.

    2014-01-01

    Within the European Union (EU) a paradigm shift is currently occurring in the waste sector, where EU waste directives and national waste strategies are placing emphasis on resource efficiency and recycling targets. The most recent Danish resource strategy calculates a national recycling rate of 22......% for household waste, and sets an ambitious goal of a 50% recycling rate by 2020. This study integrates the recycling target into the FRIDA model to project how much waste and from which streams should be diverted from incineration to recycling in order to achieve the target. Furthermore, it discusses how...... the existing technological, organizational and legislative frameworks may affect recycling activities. The results of the analysis show that with current best practice recycling rates, the 50% recycling rate cannot be reached without recycling of household biowaste. It also shows that all Danish municipalities...

  14. Optimal exploration target zones

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-09-01

    Full Text Available , Carranza, Stein, van der Meer Introduction to Remote Sensing Background and Objective of the study Methodology Results Optimal Exploration Target Zones Pravesh Debba1, Emmanual M.J. Carranza2, Alfred Stein2, Freek D. van der Meer2 1CSIR, Logistics... and Quantitative Methods, CSIR Built Environment 2International Institute for Geo-Information Science and Earth Observation (ITC), Hengelosestraat 99, P.O. Box 6, 7500AA Enschede, The Netherlands Optimal Exploration Target Zones Debba, Carranza, Stein, van der Meer...

  15. AA antiproton production target

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    The first version of the antiproton production target was a tungsten rod, 11 cm long (actually a row of 11 rods, each 1 cm long) and 3 mm in diameter. The rod was embedded in graphite, pressure-seated into an outer casing made of stainless steel. The casing had fins for forced-air cooling. In this picture, the 26 GeV high-intensity beam from the PS enters from the right, where a scintillator screen, with circles every 5 mm in radius, permits precise aim at the target centre. See also 7903034 and 7905094.

  16. Aquaporin-2 membrane targeting

    DEFF Research Database (Denmark)

    Olesen, Emma T B; Fenton, Robert A

    2017-01-01

    The targeting of the water channel aquaporin-2 (AQP2) to the apical plasma membrane of kidney collecting duct principal cells is regulated mainly by the antidiuretic peptide hormone arginine vasopressin (AVP). This process is of crucial importance for the maintenance of body water homeostasis...

  17. Microenvironmental targets in sarcoma

    Directory of Open Access Journals (Sweden)

    Monika eEhnman

    2015-11-01

    Full Text Available Sarcomas are rare malignant tumors affecting all age groups. They are typically classified according to their resemblance to corresponding normal tissue. Their heterogeneous features, for example in terms of disease-driving genetic aberrations and body location, complicate both disease classification and development of novel treatment regimens. Many years of failure of improved patient outcome in clinical trials has lead to the conclusion that novel targeted therapies are likely needed in combination with current multimodality regimens. Sarcomas have not, in contrast to the common carcinomas, been the subject for larger systematic studies on how tumor behavior relates to characteristics of the tumor microenvironment. There is consequently an urgent need for identifying suitable molecular targets, not only in tumor cells, but also in the tumor microenvironment. This review discusses preclinical and clinical data about potential molecular targets in sarcomas. Studies on targeted therapies involving the tumor microenvironment are prioritized. A greater understanding of the biological context is expected to facilitate more successful design of future clinical trials in sarcoma.

  18. Target Heart Rates

    Science.gov (United States)

    ... is your level of intensity? When is the best time of day to work out? Target Heart Rates Warm Up, Cool Down See More >> Getting Active Getting Started - Tips for Long-term Exercise Success Get Moving: Easy Tips to Get Active! ...

  19. Targeted Therapy for Melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Thomas [Alphamed, Jackson, TN (United States); Moore, Herbert [Alphamed, Jackson, TN (United States)

    2016-12-05

    The research project, entitled ”Targeted Therapy for Melanoma,” was focused on investigating the use of kidney protection measures to lower the non-specific kidney uptake of the radiolabeled Pb-DOTA-ReCCMSH peptide. Previous published work demonstrated that the kidney exhibited the highest non-target tissue uptake of the 212Pb/203Pb radiolabeled melanoma targeting peptide DOTA-ReCCMSH. The radiolabeled alpha-melanocyte stimulating hormone (α-MSH) peptide analog DOTA-Re(Arg11)CCMSH, which binds the melanocortin-1 receptor over-expressed on melanoma tumor cells, has shown promise as a PRRT agent in pre-clinical studies. High tumor uptake of 212Pb labeled DOTA-Re(Arg11)CCMSH resulted in tumor reduction or eradication in melanoma therapy studies. Of particular note was the 20-50% cure rate observed when melanoma mice were treated with alpha particle emitter 212Pb. However, as with most PRRT agents, high radiation doses to the kidneys where observed. To optimize tumor treatment efficacy and reduce nephrotoxicity, the tumor to kidney uptake ratio must be improved. Strategies to reduce kidney retention of the radiolabeled peptide, while not effecting tumor uptake and retention, can be broken into several categories including modification of the targeting peptide sequence and reducing proximal tubule reabsorption.

  20. Target Chamber Manipulator

    Science.gov (United States)

    Tantillo, Anthony; Watson, Matthew

    2015-11-01

    A system has been developed to allow remote actuation of sensors in a high vacuum target chamber used with a particle accelerator. Typically, sensors of various types are placed into the target chamber at specific radial and angular positions relative to the beam line and target. The chamber is then evacuated and the experiments are performed for those sensor positions. Then, the chamber is opened, the sensors are repositioned to new angles or radii, and the process is repeated, with a separate pump-down cycle for each set of sensor positions. The new sensor positioning system allows scientists to pre-set the radii of up to a dozen sensors, and then remotely actuate their angular positions without breaking the vacuum of the target chamber. This reduces the time required to reposition sensors from 6 hours to 1 minute. The sensors are placed into one of two tracks that are separately actuated using vacuum-grade stepping motors. The positions of the sensors are verified using absolute optical rotary encoders, and the positions are accurate to 0.5 degrees. The positions of the sensors are electronically recorded and time-stamped after every change. User control is through a GUI using LabVIEW.

  1. Active Target Simulation

    Science.gov (United States)

    Smith, Nathan; Draznik, Peter; Frank, Nathan

    2012-10-01

    We have simulated an existing experimental design to determine the resolution improvement upon energy measurements of neutron unbound nuclei. A number of experiments of this type have been performed at the National Superconducting Cyclotron Laboratory (NSCL), located at Michigan State University. An excited nucleus is typically produced with a radioactive beam interacting with a passive Beryllium target. Many different nuclei are produced in experiment, each of which immediately decays into a charged particle and neutron. The charged particles are detected and the neutrons interact in scintillation detectors such as the Modular Neutron Array (MoNA) and Large Multi-Institutional Scintillation Array (LISA). In our simulation, we have constructed an active target that provides additional information such that the point of nuclear interaction within the target may be determined. This information improves the resolution in decay energy measurements of neutron unbound isotopes. This presentation will cover some aspects of the simulation process, as well as showing some of the results that demonstrate the simulated improvement over a passive target.

  2. Design upgrade of the ISOLDE target unit for HIE-ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Montaño, J., E-mail: Jacobo.Montano@cern.ch [CERN, ISOLDE, CH-1211 Geneva 23 (Switzerland); Giles, T. [CERN, ISOLDE, CH-1211 Geneva 23 (Switzerland); Gottberg, A. [CERN, ISOLDE, CH-1211 Geneva 23 (Switzerland); Instituto de Estructura de la Materia, CSIC, 28006 Madrid (Spain)

    2013-12-15

    Highlights: • Requirements for a new target-source system for the radioactive facility HIE-ISOLDE. • For the upgraded facility a higher radiation field will be present. • The new design has to take into account the radiation field of the upgraded facility. -- Abstract: The High Intensity and Energy HIE-ISOLDE project is a major upgrade of the existing ISOLDE and REX-ISOLDE facilities with the objective of increasing the energy and the intensity of the delivered radioactive ion beams (RIB) [1]. In order to accommodate the future increase of primary beam intensity delivered by the new LINAC4 H{sup −} driver to the Proton Synchrotron Booster (PSB) [2] and from this to ISOLDE, a major study is being carried out to upgrade the existing designs of the ISOLDE target and its supporting infrastructure. In particular, the extraction optics plays an important role in the initial beam transport and the quality of the beam supplied to the mass separators. Important factors include the emittance of the beam and the beam profile to avoid beam losses. A new double electrode extraction system has been developed for simplifying and improving the interface between the target unit and the frontend (target coupling table). Numerical and experimental studies have been performed in order to define the new extraction geometry, and the coupling table has been adapted to keep the compatibility. An alternative heating system is under study. An electron bombardment heating system is being developed as an option for avoiding the employment of big cross section cables. The results of these studies and the mechanical models developed are presented and discussed.

  3. Physics of polarized targets

    CERN Document Server

    Niinikoski, Tapio

    2014-01-01

    For developing, building and operating solid polarized targets we need to understand several fields of physics that have seen sub stantial advances during the last 50 years. W e shall briefly review a selection of those that are important today. These are: 1) quantum statistical methods to describe saturation and relaxation in magnetic resonance; 2) equal spin temperature model for dy namic nuclear polarization; 3 ) weak saturation during NMR polarization measurement; 4 ) refrigeration using the quantum fluid properties of helium isotopes. These, combined with superconducting magnet technologies, permit today to reach nearly complete pola rization of almost any nuclear spins. Targets can be operated in frozen spin mode in rather low and inhomogeneous field of any orientation, and in DNP mode in beams of high intensity. Beyond such experiments of nuclear and particle physics, applications a re also emerging in macromolecular chemistry and in magnetic resonance imaging. This talk is a tribute to Michel Borghini...

  4. Emerging Targets in Photopharmacology.

    Science.gov (United States)

    Lerch, Michael M; Hansen, Mickel J; van Dam, Gooitzen M; Szymanski, Wiktor; Feringa, Ben L

    2016-09-05

    The field of photopharmacology uses molecular photoswitches to establish control over the action of bioactive molecules. It aims to reduce systemic drug toxicity and the emergence of resistance, while achieving unprecedented precision in treatment. By using small molecules, photopharmacology provides a viable alternative to optogenetics. We present here a critical overview of the different pharmacological targets in various organs and a survey of organ systems in the human body that can be addressed in a non-invasive manner. We discuss the prospects for the selective delivery of light to these organs and the specific requirements for light-activatable drugs. We also aim to illustrate the druggability of medicinal targets with recent findings and emphasize where conceptually new approaches have to be explored to provide photopharmacology with future opportunities to bring "smart" molecular design ultimately to the realm of clinical use. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Inflation Targeting: Provisional Results

    Directory of Open Access Journals (Sweden)

    Cerna, Silviu

    2010-06-01

    Full Text Available Inflation targeting monetary policy framework that requires the central bank to achieve a low inflation has contributed to price stability in industrialized countries. As well as the other developing countries, ex communist countries have also tried to apply this strategy, which was susceptible to increase monetary policy transparency and to determine authorities to make necessary reforms in order to pass from a planned to a market economy. In Romania, inflation targeting has contributed, to a large extent, to price increase smoothening, without affecting economic growth. Knowing the factors that have determined this unquestionable success allows for not only understanding the Romanian transition process, but also draw some useful conclusions in view of the necessary actions for adopting the euro.

  6. Foucault on targets.

    Science.gov (United States)

    Lynch, John

    2004-01-01

    This paper seeks to gain an insight into the behavior of a large NHS trust, in its attempt to meet a 90 percent patient access target, in a week long national audit in March 2003. Why did individuals act in dramatically different ways to their norm over this period. The work of Michel Foucault is used to explore these issues. The discourses of power, knowledge, discipline and governmentality are identified as key foucaudian themes that offer an alternative interpretation of how individuals behave in their place of work. The importance of the historical context of discourse within the NHS cannot be underestimated in shaping the behavior of individuals and groups today. Power and knowledge permeate NHS organizations through disciplinary practices and dressage. Governmentality seeks to maintain the status quo through disciplinary processes such as national healthcare targets. The natural response of NHS organizations is therefore, to seek order and conformity rather than disorder and conflict.

  7. Antibodies Targeting EMT

    Science.gov (United States)

    2017-10-01

    VLDL uptake and redistribution of lipids to cells for energy metabolism and cell signaling. ApoE overexpression has shown to be associated with a...involved in testosterone and estradiol biosynthesis, as well as prostaglandin F synthesis and has previously been implicated in cancer progression, AKR1C2...is involved in androgen metabolism and is a potential drug target for prostate cancer. AKR1C4 is involved in bile acid synthesis but has not yet

  8. Explosive Target Balances

    OpenAIRE

    Potrafke, Niklas; Reischmann, Markus

    2013-01-01

    Using the new unit root test by Phillips et al. (2011) we show that the Target balances of the German Bundesbank have been exploding from the beginning of 2009 to the beginning of 2013. By implementing a full-allotment policy and reducing the required minimum quality of collaterals in October 2008, the European Central Bank (ECB) refinanced credits in the GIIPS countries to a large extent. Private capital flowed out of the GIIPS countries (Greece, Italy, Ireland, Portugal and Spain), and the ...

  9. Implementing Target Value Design.

    Science.gov (United States)

    Alves, Thais da C L; Lichtig, Will; Rybkowski, Zofia K

    2017-04-01

    An alternative to the traditional way of designing projects is the process of target value design (TVD), which takes different departure points to start the design process. The TVD process starts with the client defining an allowable cost that needs to be met by the design and construction teams. An expected cost in the TVD process is defined through multiple interactions between multiple stakeholders who define wishes and others who define ways of achieving these wishes. Finally, a target cost is defined based on the expected profit the design and construction teams are expecting to make. TVD follows a series of continuous improvement efforts aimed at reaching the desired goals for the project and its associated target value cost. The process takes advantage of rapid cycles of suggestions, analyses, and implementation that starts with the definition of value for the client. In the traditional design process, the goal is to identify user preferences and find solutions that meet the needs of the client's expressed preferences. In the lean design process, the goal is to educate users about their values and advocate for a better facility over the long run; this way owners can help contractors and designers to identify better solutions. This article aims to inform the healthcare community about tools and techniques commonly used during the TVD process and how they can be used to educate and support project participants in developing better solutions to meet their needs now as well as in the future.

  10. Det venskabelige bombardement

    DEFF Research Database (Denmark)

    -norske monarkis magt og velstand. Syv år senere gik Norge tabt. Danmark var blevet "et lidet, fattigt land". Briterne var i krig med franskmændene og ville forhindre dem i at få den danske flåde. Militært var aktionen en succes - det måtte selv Napoleon indrømme. Men den udløste en voldsom debat om mål og midler...

  11. Inflation targeting and core inflation

    OpenAIRE

    Julie Smith

    2005-01-01

    This paper examines the interaction of core inflation and inflation targeting as a monetary policy regime. Interest in core inflation has grown because of inflation targeting. Core inflation is defined in numerous ways giving rise to many potential measures; this paper defines core inflation as the best forecaster of inflation. A cross-country study finds before the start of inflation targeting, but not after, core inflation differs between non-inflation targeters and inflation targeters. Thr...

  12. Targeted therapy for sarcomas

    Directory of Open Access Journals (Sweden)

    Forscher C

    2014-03-01

    Full Text Available Charles Forscher,1 Monica Mita,2 Robert Figlin3 1Sarcoma Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA; 2Experimental Therapeutics Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA; 3Academic Development Program, Samuel Oschin Comprehensive Cancer Institute, and Division of Hematology/Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, USA Abstract: Sarcomas are tumors of mesenchymal origin that make up approximately 1% of human cancers. They may arise as primary tumors in either bone or soft tissue, with approximately 11,280 soft tissue tumors and 2,650 bone tumors diagnosed each year in the United States. There are at least 50 different subtypes of soft tissue sarcoma, with new ones described with ever-increasing frequency. One way to look at sarcomas is to divide them into categories on the basis of their genetic make-up. One group of sarcomas has an identifiable, relatively simple genetic signature, such as the X:18 translocation seen in synovial sarcoma or the 11:22 translocation seen in Ewing's sarcoma. These specific abnormalities often lead to the presence of fusion proteins, such as EWS-FLI1 in Ewing's sarcoma, which are helpful as diagnostic tools and may become therapeutic targets in the future. Another group of sarcomas is characterized by complex genetic abnormalities as seen in leiomyosarcoma, osteosarcoma, and undifferentiated sarcoma. It is important to keep these distinctions in mind when contemplating the development of targeted agents for sarcomas. Different abnormalities in sarcoma could be divided by tumor subtype or by the molecular or pathway abnormality. However, some existing drugs or drugs in development may interfere with or alter more than one of the presented pathways. Keywords: sarcoma, targeted agents, tyrosine kinase inhibitors, mTor inhibition

  13. Meeting the Aichi targets

    DEFF Research Database (Denmark)

    Funk, Stephan M; Conde, Dalia Amor; Lamoreux, John

    2017-01-01

    &s), is an excellent opportunity to achieve the Aichi 2020 Targets T11 (protected areas) and T12 (preventing species extinctions). AZE taxa have small, single-site populations that are especially vulnerable to human-induced extinctions, particularly for the many amphibians. We show that AZEs&s can be protected...... feasibly and cost-effectively, but action is urgent. We argue that the Alliance, whose initial main aim was to identify AZEs&s, must be followed up by a second-generation initiative that directs and co-ordinates AZE conservation activities on the ground. The prominent role of zoos, conservation NGOs...

  14. Polarized scintillator targets

    Science.gov (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Mango, S.

    2000-05-01

    The hydrogen nuclei in an organic scintillator have been polarized to more than 80% and the deuterons in its fully deuterated version to 24%. The scintillator, doped with TEMPO, has been polarized dynamically in a field of 2.5 T in a vertical dilution refrigerator in which a plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat. Sizeable solid samples with acceptable optical properties and light output have been prepared and successfully operated as "live" polarized targets in nuclear physics experiments.

  15. Polarized scintillator targets

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, B. van den E-mail: vandenbrandt@psi.ch; Bunyatova, E.I.; Hautle, P.; Konter, J.A.; Mango, S

    2000-05-21

    The hydrogen nuclei in an organic scintillator have been polarized to more than 80% and the deuterons in its fully deuterated version to 24%. The scintillator, doped with TEMPO, has been polarized dynamically in a field of 2.5 T in a vertical dilution refrigerator in which a plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat. Sizeable solid samples with acceptable optical properties and light output have been prepared and successfully operated as 'live' polarized targets in nuclear physics experiments.

  16. Targeting Prostate Cancer Metastasis

    Science.gov (United States)

    2015-09-01

    achieve this goal, we cultured high-invasive prostate cancer PC3 cells and treated them with the drugs/inhibitors that were proposed to target WASF3...groups (treated by DMSO), either treated by 100 μM CYT997 or 10 μM Dasatinib suppressed the cells to spread throughout the fish body (Fig. 4). As...have scr eened t he e f fect s o f mor e t han 40 drugs on invasion using cul tur ed prost ate cancer cells and f ound t hat tar geting multiple

  17. Targeting Nuclear Thymidylate Biosynthesis

    Science.gov (United States)

    Chon, James; Stover, Patrick J.; Field, Martha S.

    2016-01-01

    Thymidylate (dTMP) biosynthesis plays an essential and exclusive function in DNA synthesis and proper cell division, and therefore has been an attractive therapeutic target. Folate analogues, known as antifolates, and nucleotide analogs that inhibit the enzymatic action of the de novo thymidylate biosynthesis pathway and are commonly used in cancer treatment. In this review, we examine the mechanisms by which the antifolate 5-fluorouracil, as well as other dTMP synthesis inhibitors, function in cancer treatment in light of emerging evidence that dTMP synthesis occurs in the nucleus. Nuclear localization of the de novo dTMP synthesis pathway requires modification of the pathway enzymes by the small ubiquitin-like modifier (SUMO) protein. SUMOylation is required for nuclear localization of the de novo dTMP biosynthesis pathway, and disruption in the SUMO pathway inhibits cell proliferation in several cancer models. We summarize evidence that the nuclear localization of the dTMP biosynthesis pathway is a critical factor in the efficacy of antifolate-based therapies that target dTMP synthesis. PMID:27876557

  18. Targeted corneal transplantation.

    Science.gov (United States)

    Jhanji, Vishal; Mehta, Jod S; Sharma, Namrata; Sharma, Bhavana; Vajpayee, Rasik B

    2012-07-01

    Corneal transplantation surgery has moved from an era of conventional penetrating keratoplasty to selective replacement of the diseased corneal layer with complementary healthy donor corneal tissue. Anterior lamellar transplantation surgeries do not involve replacement of corneal endothelium, consequently eliminating the occurrence of endothelial rejection. Similarly, in diseases affecting the corneal endothelium, selective replacement with a lamellar lenticule bearing healthy endothelium provides better outcomes in terms of ocular surface, lesser astigmatism and quick visual recovery. In addition to the advantages of enhanced surgical outcomes, targeted corneal transplantation allows the use of one donor cornea for more than one recipient, thereby offering a viable solution to the problem of paucity of donor corneas. Evolving techniques of corneal transplantation have enabled better utilization of donor corneal tissue. Anterior lamellar as well as endothelial keratoplasty surgeries have become first-choice surgeries in appropriately selected cases. This review briefly discusses some of these novel surgical techniques. A better understanding of targeted corneal transplantation would lead to adaptation of the concept of component corneal surgery. This would further enable the corneal surgeons to circumvent the problem of donor corneal shortage especially in the developing world.

  19. Fixed target beams

    CERN Document Server

    Kain, V; Cettour-Cave, S; Cornelis, K; Fraser, M A; Gatignon, L; Goddard, B; Velotti, F

    2017-01-01

    The CERN SPS (Super Proton Synchrotron) serves asLHC injector and provides beam for the North Area fixedtarget experiments. At low energy, the vertical acceptancebecomes critical with high intensity large emittance fixed tar-get beams. Optimizing the vertical available aperture is a keyingredient to optimize transmission and reduce activationaround the ring. During the 2016 run a tool was developed toprovide an automated local aperture scan around the entirering.The flux of particles slow extracted with the1/3inte-ger resonance from the Super Proton Synchrotron at CERNshould ideally be constant over the length of the extractionplateau, for optimum use of the beam by the fixed target ex-periments in the North Area. The extracted intensity is con-trolled in feed-forward correction of the horizontal tune viathe main SPS quadrupoles. The Mains power supply noiseat 50 Hz and harmonics is also corrected in feed-forwardby small amplitude tune modulation at the respective fre-quencies with a dedicated additional quad...

  20. Old Drug, New Target

    Science.gov (United States)

    Andrews, William J.; Panova, Tatiana; Normand, Christophe; Gadal, Olivier; Tikhonova, Irina G.; Panov, Konstantin I.

    2013-01-01

    Transcription by RNA polymerase I (Pol-I) is the main driving force behind ribosome biogenesis, a fundamental cellular process that requires the coordinated transcription of all three nuclear polymerases. Increased Pol-I transcription and the concurrent increase in ribosome biogenesis has been linked to the high rates of proliferation in cancers. The ellipticine family contains a number of potent anticancer therapeutic agents, some having progressed to stage I and II clinical trials; however, the mechanism by which many of the compounds work remains unclear. It has long been thought that inhibition of Top2 is the main reason behind the drugs antiproliferative effects. Here we report that a number of the ellipticines, including 9-hydroxyellipticine, are potent and specific inhibitors of Pol-I transcription, with IC50 in vitro and in cells in the nanomolar range. Essentially, the drugs did not affect Pol-II and Pol-III transcription, demonstrating a high selectivity. We have shown that Pol-I inhibition occurs by a p53-, ATM/ATR-, and Top2-independent mechanism. We discovered that the drug influences the assembly and stability of preinitiation complexes by targeting the interaction between promoter recognition factor SL1 and the rRNA promoter. Our findings will have an impact on the design and development of novel therapeutic agents specifically targeting ribosome biogenesis. PMID:23293027

  1. Quantum state targeting

    Science.gov (United States)

    Rudolph, Terry; Spekkens, Robert W.

    2004-11-01

    We introduce a primitive for quantum cryptography that we term “state targeting.” We show that increasing one’s probability of success in this task above a minimum amount implies an unavoidable increase in the probability of a particular kind of failure. This is analogous to the unavoidable disturbance to a quantum state that results from gaining information about its identity, and can be shown to be a purely quantum effect. We solve various optimization problems for state targeting that are useful for the security analysis of two-party cryptographic tasks implemented between remote antagonistic parties. Although we focus on weak coin flipping, the results are significant for other two-party protocols, such as strong coin flipping, partially binding and concealing bit commitment, and bit escrow. Furthermore, the results have significance not only for the traditional notion of security in cryptography, that of restricting a cheater’s ability to bias the outcome of the protocol, but also for a different notion of security that arises only in the quantum context, that of cheat sensitivity. Finally, our analysis leads to some interesting secondary results, namely, a generalization of Uhlmann’s theorem and an operational interpretation of the fidelity between two mixed states.

  2. Target Housing Material Options

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-11

    With gas cooling, heat transfer coefficients are low compared to water. The benefit of gas from a heat transfer point of view is that there is really no upper temperature limit for the coolant, as compared to water, which is limited ultimately by the critical point, and in practice the critical heat flux. In our case with parallel flow channels, water is limited to even lower operating limits by nucleate boiling. So gas can get as hot as the containment material will allow, but to get the density and heat transfer up to something reasonable, we must also increase pressure, thus increasing stress on the containment, namely the front and back faces. We are designing to ASME BPVC, which, for most materials allows a maximum stress of UTS/3. So we want the highest possible UTS. For reference, the front face stress in the 12 mm target at 300 psi was about 90 MPa. The inconel 718 allowable stress at 900°C is 1/3 of 517 or 172 MPa. So we are in a very safe place, but the uTS is dropping rapidly with temperature above 900°C. As we increase target diameter, the challenge will be to keep the stress down. We are probably looking at keeping the allowable at or above the present value, and at as high a temperature as possible.

  3. Targeting adipose tissue

    Directory of Open Access Journals (Sweden)

    Haas Bodo

    2012-10-01

    Full Text Available Abstract Two different types of adipose tissues can be found in humans enabling them to respond to starvation and cold: white adipose tissue (WAT is generally known and stores excess energy in the form of triacylglycerol (TG, insulates against cold, and serves as a mechanical cushion. Brown adipose tissue (BAT helps newborns to cope with cold. BAT has the capacity to uncouple the mitochondrial respiratory chain, thereby generating heat rather than adenosine triphosphate (ATP. The previously widely held view was that BAT disappears rapidly after birth and is no longer present in adult humans. Using positron emission tomography (PET, however, it was recently shown that metabolically active BAT occurs in defined regions and scattered in WAT of the adult and possibly has an influence on whole-body energy homeostasis. In obese individuals adipose tissue is at the center of metabolic syndrome. Targeting of WAT by thiazolidinediones (TZDs, activators of peroxisome proliferator-activated receptor γ (PPARγ a ‘master’ regulator of fat cell biology, is a current therapy for the treatment of type 2 diabetes. Since its unique capacity to increase energy consumption of the body and to dissipate surplus energy as heat, BAT offers new perspectives as a therapeutic target for the treatment of obesity and associated diseases such as type 2 diabetes and metabolic syndrome. Recent discoveries of new signaling pathways of BAT development give rise to new therapeutic possibilities in order to influence BAT content and activity.

  4. Targeting adipose tissue.

    Science.gov (United States)

    Haas, Bodo; Schlinkert, Paul; Mayer, Peter; Eckstein, Niels

    2012-10-27

    Two different types of adipose tissues can be found in humans enabling them to respond to starvation and cold: white adipose tissue (WAT) is generally known and stores excess energy in the form of triacylglycerol (TG), insulates against cold, and serves as a mechanical cushion. Brown adipose tissue (BAT) helps newborns to cope with cold. BAT has the capacity to uncouple the mitochondrial respiratory chain, thereby generating heat rather than adenosine triphosphate (ATP). The previously widely held view was that BAT disappears rapidly after birth and is no longer present in adult humans. Using positron emission tomography (PET), however, it was recently shown that metabolically active BAT occurs in defined regions and scattered in WAT of the adult and possibly has an influence on whole-body energy homeostasis. In obese individuals adipose tissue is at the center of metabolic syndrome. Targeting of WAT by thiazolidinediones (TZDs), activators of peroxisome proliferator-activated receptor γ (PPARγ) a 'master' regulator of fat cell biology, is a current therapy for the treatment of type 2 diabetes. Since its unique capacity to increase energy consumption of the body and to dissipate surplus energy as heat, BAT offers new perspectives as a therapeutic target for the treatment of obesity and associated diseases such as type 2 diabetes and metabolic syndrome. Recent discoveries of new signaling pathways of BAT development give rise to new therapeutic possibilities in order to influence BAT content and activity.

  5. Low intensity beam target unit

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    This is a wheel fitted with many targets around its periphery (each with three longitudinally arranged thin rods) of which one is placed into the beam via a rotation of the wheel. Upstream of each target is placed a luminescent screen, aligbed on each target axis and viewed with a TV camera, to make sure that one is hitting the target. This target unit was probably used to study target's behaviour (like beam heating). Gualtiero Del Torre stands on the left, Pierre Gerdil on the right.

  6. Issues in Target Tracking

    Science.gov (United States)

    2010-05-01

    simulations we take as ground truth that the target moves at 10m/s heading west and 5m/s heading north, starting from ( 5000m , 35000m). The emitted frequency is... runs , the estimated initial and final positions fall into the 99% confidence region. −1 −0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.6 0.8 1 x 10 4 0 0.5 1 1.5 2 2.5...position of trajectories. “F”: final position of trajectories. Right: The true and estimated trajectories from 100 Monte Carlo runs for Johnson noise

  7. Bradycardia During Targeted Temperature Management

    DEFF Research Database (Denmark)

    Thomsen, Jakob Hartvig; Nielsen, Niklas; Hassager, Christian

    2016-01-01

    OBJECTIVES: Bradycardia is common during targeted temperature management, likely being a physiologic response to lower body temperature, and has recently been associated with favorable outcome following out-of-hospital cardiac arrest in smaller observational studies. The present study sought...... to confirm this finding in a large multicenter cohort of patients treated with targeted temperature management at 33°C and explore the response to targeted temperature management targeting 36°C. DESIGN: Post hoc analysis of a prospective randomized study. SETTING: Thirty-six ICUs in 10 countries. PATIENTS......: We studied 447 (targeted temperature management = 33°C) and 430 (targeted temperature management = 36°C) comatose out-of-hospital cardiac arrest patients with available heart rate data, randomly assigned in the targeted temperature management trial from 2010 to 2013. INTERVENTIONS: Targeted...

  8. Characterization of solid hydrogen targets

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, M.C. [British Columbia Univ., Vancouver, BC (Canada); Bailey, J.M.; Mulhauser, F. [Chester Technology (United Kingdom); Beer, G.A.; Douglas, J.L.; Knowles, P.E.; Maier, M.; Mason, G.R.; Olin, A.; Porcelli, T.A. [Victoria Univ., BC (Canada); Beveridge, J.L.; Marshall, G.M. [British Columbia Univ., Vancouver, BC (Canada). TRIUMF Facility; Huber, T.M. [Gustavus Adolphus Coll., St. Peter, MN (United States); Jacot-Guillarmod, R. [Fribourg Univ. (Switzerland); Kammel, P. [Lawrence Berkeley Lab., CA (United States); Kim, S.K. [Jeonbuk National Univ., Jeonju City (Korea, Republic of); Kunselman, A.R. [Wyoming Univ., Laramie, WY (United States); Martoff, C.J. [Temple Univ., Philadelphia, PA (United States); Petitjean, C. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Zmeskal, J. [Oesterreichische Akademie der Wissenschaften, Vienna (Austria)

    1996-10-01

    In experiments using the TRIUMF solid hydrogen target system, the knowledge of the target thickness and uniformity is often essential in order to extract physical parameters from the data. We have characterized the thickness and uniformity of frozen targets using the energy loss of alpha particles. An accuracy of {approx}5% was achieved, a limit imposed by the uncertainty in the stopping powers. The details of the method are described, and the thickness calibration of the target is presented. (orig.). 11 refs.

  9. Emission of low-energetic electrons in collisions of heavy ions with solid targets; Emission niederenergetischer Elektronen in Stoessen von schweren Ionen mit Festkoerpertargets

    Energy Technology Data Exchange (ETDEWEB)

    Lineva, Natallia

    2008-07-15

    At the UNILAC accelerator, we have initiated a project with the objective to investigate lowenergy electrons, emitted from solid, electrically conductive targets after the impact of swift light and heavy ions. For this purposes, we have installed, optimized, and put into operation an electrostatic toroidal electron spectrometer. First, investigations of electrons, emitted from solid-state targets after the bombardment with a monochromatic electron beam from an electron gun, has been carried out. The proposed method combines the results of the measurements with the results of dedicated Monte Carlo simulations. The method has been elaborated in a case study for carbon targets. The findings have been instrumental for the interpretation of our measurements of electrons emitted in collisions of swift ions with the same carbon targets. Our investigations focused on following ion beams: protons and (H{sup +}{sub 3})-molecules of the same energy, as well as on carbon ions with two different energies. Thin carbon, nickel, argon and gold foils has been used as targets. Electrons in the energy range between 50 eV and 1 keV have been investigated. The measured electron distributions, both integral as well as differential with respect to the polar angle, have been compared to simple standard theories for gases as well as to the results of TRAX simulations, the latter being based on data from gaseous targets. Dedicated TRAX simulations have been performed only for the carbon targets, applying the method mentioned above. Within our experimental uncertainties, we observe a good agreement of the measured and TRAX simulated data. That leads us to the conclusion that - as a first order approximation - the electron emission pattern from ion-atom collisions in solid-state targets and the one from single collisions in gases are similar. (orig.)

  10. Target noise in overlay metrology

    Science.gov (United States)

    Seligson, Joel L.; Adel, Mike E.; Izikson, Pavel; Levinski, Vladimir; Yaffe, Dan

    2004-05-01

    We have developed a method for calculating the statistical effects of spatial noise on the overlay measurement extracted from a given overlay target. The method has been applied to two kinds of overlay targets on three process layers, and the new metric, Target Noise, has been shown to correlate well to the random component of Overlay Mark Fidelity. A significant difference in terms of robustness has been observed between AIM targets and conventional Frame-in-Frame targets. The results fit well into the spatial noise hierarchy presented in this paper.

  11. EURISOL High Power Targets

    CERN Document Server

    Kadi, Y; Lindroos, M; Ridikas, D; Stora, T; Tecchio, L; CERN. Geneva. BE Department

    2009-01-01

    Modern Nuclear Physics requires access to higher yields of rare isotopes, that relies on further development of the In-flight and Isotope Separation On-Line (ISOL) production methods. The limits of the In-Flight method will be applied via the next generation facilities FAIR in Germany, RIKEN in Japan and RIBF in the USA. The ISOL method will be explored at facilities including ISAC-TRIUMF in Canada, SPIRAL-2 in France, SPES in Italy, ISOLDE at CERN and eventually at the very ambitious multi-MW EURISOL facility. ISOL and in-flight facilities are complementary entities. While in-flight facilities excel in the production of very short lived radioisotopes independently of their chemical nature, ISOL facilities provide high Radioisotope Beam (RIB) intensities and excellent beam quality for 70 elements. Both production schemes are opening vast and rich fields of nuclear physics research. In this article we will introduce the targets planned for the EURISOL facility and highlight some of the technical and safety cha...

  12. The target effect: visual memory for unnamed search targets.

    Science.gov (United States)

    Thomas, Mark D; Williams, Carrick C

    2014-01-01

    Search targets are typically remembered much better than other objects even when they are viewed for less time. However, targets have two advantages that other objects in search displays do not have: They are identified categorically before the search, and finding them represents the goal of the search task. The current research investigated the contributions of both of these types of information to the long-term visual memory representations of search targets. Participants completed either a predefined search or a unique-object search in which targets were not defined with specific categorical labels before searching. Subsequent memory results indicated that search target memory was better than distractor memory even following ambiguously defined searches and when the distractors were viewed significantly longer. Superior target memory appears to result from a qualitatively different representation from those of distractor objects, indicating that decision processes influence visual memory.

  13. Targeting regulatory T cells to improve vaccine immunogenicity in early life

    Directory of Open Access Journals (Sweden)

    Jorjoh eNdure

    2014-09-01

    Full Text Available Human newborns and infants are bombarded with multiple pathogens on leaving the sterile intra-uterine environment, and yet have suboptimal innate immunity and limited immunological memory, thus leading to increased susceptibility to infections in early life. They are thus the target age group for a host of vaccines against common bacterial and viral pathogens. They are also the target group for many vaccines in development, including those against tuberculosis (TB, malaria and HIV infection. However, neonatal and infant responses to many vaccines are suboptimal, and in the case of the polysaccharide vaccines, it has been necessary to develop the alternative conjugated formulations in order to induce immunity in early life. Immunoregulatory factors are an intrinsic component of natural immunity necessary to dampen or control immune responses, with the caveat that they may also decrease immunity to infections or lead to chronic infection. This review explores the key immunoregulatory factors at play in early life, with a particular emphasis on regulatory T cells (Tregs. It goes on to explore the role that Tregs play in limting vaccine immunogenicity, and describes animal and human studies in which Tregs have been depleted in order to enhance vaccine responses. A deeper understanding of the role that Tregs play in limiting or controlling vaccine induced immunity would provide strategies to improve vaccine immunogenicity in this critical age group. New adjuvants and drugs are being developed that can transiently suppress Treg function, and their use as part of human vaccination strategies against infections is becoming a real prospect for the future.

  14. Guidance and targeting for the Strategic Target System

    Science.gov (United States)

    White, John E.

    Guidance algorithms and targeting procedures for the Strategic Target System (STARS) launch vehicle are described. The STARS vehicle is a three stage booster, based partly upon retired Polaris A3 missile assets, which is intended to support development and testing of the Strategic Defense Initiative by delivering target payloads to the vicinity of the Kwajalein Atoll. STARS will be launched from the Kauai Test Facility located on Kauai, Hawaii. The STARS guidance objective is to deliver payloads to a prescribed target location with maximum accuracy at intercontinental ballistic missile velocities. Mission objectives are achieved with a combination of guidance algorithms.

  15. Oxide Fiber Targets at ISOLDE

    CERN Document Server

    Köster, U; Carminati, D; Catherall, R; Cederkäll, J; Correia, J G; Crepieux, B; Dietrich, M; Elder, K; Fedosseev, V; Fraile-Prieto, L M; Franchoo, S; Fynbo, H O U; Georg, U; Giles, T; Joinet, A; Jonsson, O C; Kirchner, R; Lau, C; Lettry, Jacques; Maier, H J; Mishin, V I; Oinonen, M; Peräjärvi, K; Ravn, H L; Rinaldi, T; Santana-Leitner, M; Wahl, U; Weissman, L

    2003-01-01

    Many elements are rapidly released from oxide matrices. Some oxide powder targets show a fast sintering, thus losing their favorable release characteristics. Loosely packed oxyde fiber targets are less critical since they may maintain their open structure even when starting to fuse together at some contact points. The experience with various oxyde fiber targets (titania, zirconia, ceria and thoria) used in the last years at ISOLDE is reviewed. For short-lived isotopes of Cu, Ga and Xe the zirconia and ceria targets respectively provided significantly higher yields than any other target (metal foils, oxide powders, etc.) tested before. Titania fibers, which were not commercially available, were produced in a relic process by impregnation of a rayon felt in a titanium chloride solution and subsequent calcination by heating the dried felt in air. Thoria fibers were obtained either by the same process or by burning commercial gas lantern mantle cloth. In the future a beryllia fiber target could be used to produce...

  16. Therapeutic Targeting of Telomerase

    Directory of Open Access Journals (Sweden)

    Kathrin Jäger

    2016-07-01

    Full Text Available Telomere length and cell function can be preserved by the human reverse transcriptase telomerase (hTERT, which synthesizes the new telomeric DNA from a RNA template, but is normally restricted to cells needing a high proliferative capacity, such as stem cells. Consequently, telomerase-based therapies to elongate short telomeres are developed, some of which have successfully reached the stage I in clinical trials. Telomerase is also permissive for tumorigenesis and 90% of all malignant tumors use telomerase to obtain immortality. Thus, reversal of telomerase upregulation in tumor cells is a potential strategy to treat cancer. Natural and small-molecule telomerase inhibitors, immunotherapeutic approaches, oligonucleotide inhibitors, and telomerase-directed gene therapy are useful treatment strategies. Telomerase is more widely expressed than any other tumor marker. The low expression in normal tissues, together with the longer telomeres in normal stem cells versus cancer cells, provides some degree of specificity with low risk of toxicity. However, long term telomerase inhibition may elicit negative effects in highly-proliferative cells which need telomerase for survival, and it may interfere with telomere-independent physiological functions. Moreover, only a few hTERT molecules are required to overcome senescence in cancer cells, and telomerase inhibition requires proliferating cells over a sufficient number of population doublings to induce tumor suppressive senescence. These limitations may explain the moderate success rates in many clinical studies. Despite extensive studies, only one vaccine and one telomerase antagonist are routinely used in clinical work. For complete eradication of all subpopulations of cancer cells a simultaneous targeting of several mechanisms will likely be needed. Possible technical improvements have been proposed including the development of more specific inhibitors, methods to increase the efficacy of vaccination

  17. Target Acquisition Methodology Enhancement (TAME)

    Science.gov (United States)

    1989-03-01

    acquisition probability from COMINT, PCOM , against all communications type targets, is determined offline by a stochastic model for subsequent...of PN over all replications. F-4 f. Computes overall acquisition probability, PCOM , against all communications type targets as C: PCOM = (1. - PN...NNET where NNET denotes the number of nets which the target is in. F-6. TOTAL ACQUISITION PROBABILITY. With PNCj and PCOM computed as above, the

  18. Guidance system for laser targets

    Science.gov (United States)

    Porter, Gary D.; Bogdanoff, Anatoly

    1978-01-01

    A system for guiding charged laser targets to a predetermined focal spot of a laser along generally arbitrary, and especially horizontal, directions which comprises a series of electrostatic sensors which provide inputs to a computer for real time calculation of position, velocity, and direction of the target along an initial injection trajectory, and a set of electrostatic deflection means, energized according to a calculated output of said computer, to change the target trajectory to intercept the focal spot of the laser which is triggered so as to illuminate the target of the focal spot.

  19. Targeted nanotechnology for cancer imaging.

    Science.gov (United States)

    Toy, Randall; Bauer, Lisa; Hoimes, Christopher; Ghaghada, Ketan B; Karathanasis, Efstathios

    2014-09-30

    Targeted nanoparticle imaging agents provide many benefits and new opportunities to facilitate accurate diagnosis of cancer and significantly impact patient outcome. Due to the highly engineerable nature of nanotechnology, targeted nanoparticles exhibit significant advantages including increased contrast sensitivity, binding avidity and targeting specificity. Considering the various nanoparticle designs and their adjustable ability to target a specific site and generate detectable signals, nanoparticles can be optimally designed in terms of biophysical interactions (i.e., intravascular and interstitial transport) and biochemical interactions (i.e., targeting avidity towards cancer-related biomarkers) for site-specific detection of very distinct microenvironments. This review seeks to illustrate that the design of a nanoparticle dictates its in vivo journey and targeting of hard-to-reach cancer sites, facilitating early and accurate diagnosis and interrogation of the most aggressive forms of cancer. We will report various targeted nanoparticles for cancer imaging using X-ray computed tomography, ultrasound, magnetic resonance imaging, nuclear imaging and optical imaging. Finally, to realize the full potential of targeted nanotechnology for cancer imaging, we will describe the challenges and opportunities for the clinical translation and widespread adaptation of targeted nanoparticles imaging agents. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Targets and Secondary Beam Extraction

    Science.gov (United States)

    Noah, Etam

    2014-02-01

    Several applications make use of secondary beams of particles generated by the interaction of a primary beam of particles with a target. Spallation neutrons, bremsstrahlung photon-produced neutrons, radioactive ions and neutrinos are available to users at state-of-the-art facilities worldwide. Plans for even higher secondary beam intensities place severe constraints on the design of targets. This article reports on the main targetry challenges and highlights a variety of solutions for targetry and secondary beam extraction. Issues related to target station layout, instrumentation at the beam-target interface, safety and radioprotection are also discussed.

  1. Achieving Plant CRISPR Targeting that Limits Off-Target Effects

    Directory of Open Access Journals (Sweden)

    Jeffrey D. Wolt

    2016-11-01

    Full Text Available The CRISPR-Cas9 system (clustered regularly interspaced short palindromic repeats with associated Cas9 protein has been used to generate targeted changes for direct modification of endogenous genes in an increasing number of plant species; but development of plant genome editing has not yet fully considered potential off-target mismatches that may lead to unintended changes within the genome. Assessing the specificity of CRISPR-Cas9 for increasing editing efficiency as well as the potential for unanticipated downstream effects from off-target mutations is an important regulatory consideration for agricultural applications. Increasing genome-editing specificity entails developing improved design methods that better predict the prevalence of off-target mutations as a function of genome composition and design of the engineered ribonucleoprotein (RNP. Early results from CRISPR-Cas9 genome editing in plant systems indicate that the incidence of off-target mutation frequencies is quite low; however, by analyzing CRISPR-edited plant lines and improving both computational tools and reagent design, it may be possible to further decrease unanticipated effects at potential mismatch sites within the genome. This will provide assurance that CRISPR-Cas9 reagents can be designed and targeted with a high degree of specificity. Improved and experimentally validated design tools for discriminating target and potential off-target positions that incorporate consideration of the designed nuclease fidelity and selectivity will help to increase confidence for regulatory decision making for genome-edited plants.

  2. Literature evidence in open targets - a target validation platform.

    Science.gov (United States)

    Kafkas, Şenay; Dunham, Ian; McEntyre, Johanna

    2017-06-06

    We present the Europe PMC literature component of Open Targets - a target validation platform that integrates various evidence to aid drug target identification and validation. The component identifies target-disease associations in documents and ranks the documents based on their confidence from the Europe PMC literature database, by using rules utilising expert-provided heuristic information. The confidence score of a given document represents how valuable the document is in the scope of target validation for a given target-disease association by taking into account the credibility of the association based on the properties of the text. The component serves the platform regularly with the up-to-date data since December, 2015. Currently, there are a total number of 1168365 distinct target-disease associations text mined from >26 million PubMed abstracts and >1.2 million Open Access full text articles. Our comparative analyses on the current available evidence data in the platform revealed that 850179 of these associations are exclusively identified by literature mining. This component helps the platform's users by providing the most relevant literature hits for a given target and disease. The text mining evidence along with the other types of evidence can be explored visually through https://www.targetvalidation.org and all the evidence data is available for download in json format from https://www.targetvalidation.org/downloads/data .

  3. Transverse target spin asymmetries on a proton target at COMPASS

    CERN Document Server

    Richter, Andreas

    2009-01-01

    Transversity and transverse momentum-dependent parton distribution functions (TMDs) are been measured in semi-inclusive deep inelastic scattering (SIDIS) by using a transversely polarized target at the COMPASS experiment. COMPASS is a fixed target experiment at the CERN M2 beamline, which provides a 160GeV/c polarized m+ beam. In the years 2002-2004 COMPASS has collected data with a transversely polarized deuteron 6LiD target. In 2007, COMPASS has used for the first time a proton NH3 target. To access transversity COMPASS has used three different quark polarimeters: the Collins effect, responsible for an azimuthal asymmetry in the single hadron distribution, azimuthal target spin asymmetries of charged hadron pairs and the transverse polarisation of L hyperons. Beside this also the Sivers asymmetry arising from the correlation between the transverse nucleon spin and the quark intrinsic transverse momentum was measured. European

  4. Treating rheumatoid arthritis to target

    DEFF Research Database (Denmark)

    Smolen, Josef S; Aletaha, Daniel; Bijlsma, Johannes W J

    2010-01-01

    BACKGROUND: Aiming at therapeutic targets has reduced the risk of organ failure in many diseases such as diabetes or hypertension. Such targets have not been defined for rheumatoid arthritis (RA). OBJECTIVE: /st> To develop recommendations for achieving optimal therapeutic outcomes in RA. METHODS...

  5. Treating rheumatoid arthritis to target

    DEFF Research Database (Denmark)

    Smolen, Josef S; Breedveld, Ferdinand C; Burmester, Gerd R

    2016-01-01

    BACKGROUND: Reaching the therapeutic target of remission or low-disease activity has improved outcomes in patients with rheumatoid arthritis (RA) significantly. The treat-to-target recommendations, formulated in 2010, have provided a basis for implementation of a strategic approach towards this t...

  6. Saccadic adaptation to moving targets.

    Directory of Open Access Journals (Sweden)

    Katharina Havermann

    Full Text Available Saccades are so called ballistic movements which are executed without online visual feedback. After each saccade the saccadic motor plan is modified in response to post-saccadic feedback with the mechanism of saccadic adaptation. The post-saccadic feedback is provided by the retinal position of the target after the saccade. If the target moves after the saccade, gaze may follow the moving target. In that case, the eyes are controlled by the pursuit system, a system that controls smooth eye movements. Although these two systems have in the past been considered as mostly independent, recent lines of research point towards many interactions between them. We were interested in the question if saccade amplitude adaptation is induced when the target moves smoothly after the saccade. Prior studies of saccadic adaptation have considered intra-saccadic target steps as learning signals. In the present study, the intra-saccadic target step of the McLaughlin paradigm of saccadic adaptation was replaced by target movement, and a post-saccadic pursuit of the target. We found that saccadic adaptation occurred in this situation, a further indication of an interaction of the saccadic system and the pursuit system with the aim of optimized eye movements.

  7. Saccadic adaptation to moving targets.

    Science.gov (United States)

    Havermann, Katharina; Volcic, Robert; Lappe, Markus

    2012-01-01

    Saccades are so called ballistic movements which are executed without online visual feedback. After each saccade the saccadic motor plan is modified in response to post-saccadic feedback with the mechanism of saccadic adaptation. The post-saccadic feedback is provided by the retinal position of the target after the saccade. If the target moves after the saccade, gaze may follow the moving target. In that case, the eyes are controlled by the pursuit system, a system that controls smooth eye movements. Although these two systems have in the past been considered as mostly independent, recent lines of research point towards many interactions between them. We were interested in the question if saccade amplitude adaptation is induced when the target moves smoothly after the saccade. Prior studies of saccadic adaptation have considered intra-saccadic target steps as learning signals. In the present study, the intra-saccadic target step of the McLaughlin paradigm of saccadic adaptation was replaced by target movement, and a post-saccadic pursuit of the target. We found that saccadic adaptation occurred in this situation, a further indication of an interaction of the saccadic system and the pursuit system with the aim of optimized eye movements.

  8. Target recognition by wavelet transform

    CERN Document Server

    Li Zheng Dong; He Wu Liang; Pei Chun Lan; Peng Wen; SongChen; Zheng Xiao Dong

    2002-01-01

    Wavelet transform has an important character of multi-resolution power, which presents pyramid structure, and this character coincides the way by which people distinguish object from coarse to fineness and from large to tiny. In addition to it, wavelet transform benefits to reducing image noise, simplifying calculation, and embodying target image characteristic point. A method of target recognition by wavelet transform is provided

  9. ISOLDE target zone control room

    CERN Multimedia

    2016-01-01

    Operating the ISOLDE target handling robots from the dedicated control room in building 197. Monitors showing the movements of the robots (GPS in this case) in the target zone. The footage shows the actual operation by the operator as well as the different equipment such as camera electronics, camera motor controls, camera monitors and Kuka robot controls touch panel.

  10. Targeted marketing and public health.

    Science.gov (United States)

    Grier, Sonya A; Kumanyika, Shiriki

    2010-01-01

    Targeted marketing techniques, which identify consumers who share common needs or characteristics and position products or services to appeal to and reach these consumers, are now the core of all marketing and facilitate its effectiveness. However, targeted marketing, particularly of products with proven or potential adverse effects (e.g., tobacco, alcohol, entertainment violence, or unhealthful foods) to consumer segments defined as vulnerable raises complex concerns for public health. It is critical that practitioners, academics, and policy makers in marketing, public health, and other fields recognize and understand targeted marketing as a specific contextual influence on the health of children and adolescents and, for different reasons, ethnic minority populations and other populations who may benefit from public health protections. For beneficial products, such understanding can foster more socially productive targeting. For potentially harmful products, understanding the nature and scope of targeted marketing influences will support identification and implementation of corrective policies.

  11. Oxide fiber targets at ISOLDE

    DEFF Research Database (Denmark)

    Köster, U.; Bergmann, U.C.; Carminati, D.

    2003-01-01

    Many elements are rapidly released from oxide matrices. Some oxide powder targets show a fast sintering, thus losing their favorable release characteristics. Loosely packed oxide fiber targets are less critical since they may maintain their open structure even when starting to fuse together at some...... contact points. The experience with various oxide fiber targets (titania, zirconia, ceria and thoria) used in the last years at ISOLDE is reviewed. For short-lived isotopes of Cu, Ga and Xe the zirconia and ceria targets respectively provided significantly higher yields than any other target (metal foils......, oxide powders, etc.) tested before. Titania fibers, which were not commercially available, were produced in a relic process by impregnation of a rayon felt in a titanium chloride solution and subsequent calcination by heating the dried felt in air. Thoria fibers were obtained either by the same process...

  12. The Bering Target Tracking Instrumentation

    DEFF Research Database (Denmark)

    Denver, Troelz; Jørgensen, John Leif; Betto, Maurizio

    2003-01-01

    The key science instrument on the Bering satellite mission is a relative small telescope with an entrance aperture of 300 mm and a focal length between 500 and 1000 mm. The detection of potential targets is performed by one of the target scanning advanced stellar compasses (ASCs). This procedure...... results in a simple prioritized list of right ascension, declination, proper motion and intensity of each prospective target. The telescope itself has a dedicated ASC Camera Head Unit (CHU) mounted on the secondary mirror, largely co-aligned with the telescope. This CHU accurately determines the telescope......'s pointing direction. To achieve fast tracking over a large solid angle, the telescope pointing is achieved by means of a folding mirror in the optical pathway. When a prospective target approaches the telescope FOV, the ASC on the secondary will guide the folding mirror into position such that the target...

  13. High speed cryogenic monodisperse targets

    Science.gov (United States)

    Boukharov, A.; Vishnevkii, E.

    2017-11-01

    The basic possibility of creation of high speed cryogenic monodisperse targets is shown. According to calculations at input of thin liquid cryogenic jets with a velocity of bigger 100 m/s in vacuum the jets don’t manage to freeze at distance to 1 mm and can be broken into monodisperse drops. Drops due to evaporation are cooled and become granules. High speed cryogenic monodisperse targets have the following advantages: direct input in vacuum (there is no need for a chamber of a triple point chamber and sluices), it is possible to use the equipment of a cluster target, it is possible to receive targets with a diameter of D 100m/s), exact synchronization of the target hitting moment in a beam with the moment of sensors turning on.

  14. Optimization of particle bombardment parameters for the genetic transformation of Brazilian maize inbred lines Otimização dos parâmetros de bombardeamento de partículas para a transformação genética de linhagens brasileiras de milho

    Directory of Open Access Journals (Sweden)

    Caroline Pereira Petrillo

    2008-03-01

    Full Text Available The objective of this work was to develop a genetic transformation system for tropical maize genotypes via particle bombardment of immature zygotic embryos. Particle bombardment was carried out using a genetic construct with bar and uidA genes under control of CaMV35S promoter. The best conditions to transform maize tropical inbred lines L3 and L1345 were obtained when immature embryos were cultivated, prior to the bombardment, in higher osmolarity during 4 hours and bombarded at an acceleration helium gas pressure of 1,100 psi, two shots per plate, and a microcarrier flying distance of 6.6 cm. Transformation frequencies obtained using these conditions ranged from 0.9 to 2.31%. Integration of foreign genes into the genome of maize plants was confirmed by Southern blot analysis as well as bar and uidA gene expressions. The maize genetic transformation protocol developed in this work will possibly improve the efficiency to produce new transgenic tropical maize lines expressing desirable agronomic characteristics.O objetivo deste trabalho foi desenvolver um sistema de transformação genética para genótipos tropicais de milho pelo bombardeamento de embriões imaturos com micropartículas. O bombardeamento com partículas foi realizado utilizando-se uma construção gênica contendo os genes bar e uidA sob o controle do promotor CaMV35S. As melhores condições para transformação das linhagens de milho tropical L3 e L1345 foram obtidas após o cultivo de embriões imaturos durante 4 horas, antes do bombardeamento, em alta osmolaridade, e bombardeados com a pressão de 1.100 psi de gás hélio, dois tiros por placa e uma distância de vôo da micropartícula de 6,6 cm. As freqüências de transformação obtidas variaram entre 0,9 e 2,31%. A integração dos genes heterólogos no genoma das plantas transgênicas de milho foi confirmada por análises de Southern blot e expressão dos genes bar e uidA. O protocolo de transformação genética de

  15. Tracking Target and Spiral Waves

    DEFF Research Database (Denmark)

    Jensen, Flemming G.; Sporring, Jon; Nielsen, Mads

    2002-01-01

    A new algorithm for analyzing the evolution of patterns of spiral and target waves in large aspect ratio chemical systems is introduced. The algorithm does not depend on finding the spiral tip but locates the center of the pattern by a new concept, called the spiral focus, which is defined...... by the evolutes of the actual spiral or target wave. With the use of Gaussian smoothing, a robust method is developed that permits the identification of targets and spirals foci independently of the wave profile. Examples of an analysis of long image sequences from experiments with the Belousov...

  16. Targeted intraoperative radiotherapy in oncology

    CERN Document Server

    Keshtgar, Mohammed; Wenz, Frederik

    2014-01-01

    Targeted intraoperative radiotherapy is a major advance in the management of cancer patients. With an emphasis on practical aspects, this book offers an ideal introduction to this innovative  technology for clinicians.

  17. Hyperspectral-Augmented Target Tracking

    National Research Council Canada - National Science Library

    Soliman, Neil A

    2008-01-01

    ... air with the capability to seek, monitor, and destroy mobile terrorist targets in hostile territory. One such capability recognizes and persistently tracks multiple moving vehicles in complex, highly ambiguous urban environments...

  18. After treat-to-target

    DEFF Research Database (Denmark)

    Wakefield, Richard J; D'Agostino, Maria Antonietta; Naredo, Esperanza

    2012-01-01

    have recently formed a research network - the Targeted Ultrasound Initiative (TUI) group. The statement proposes that targeting therapy to PD activity provides superior outcomes compared with treating to clinical targets alone and introduces the rationale for a new randomised trial using targeted...... defined by clinical remission criteria (disease activity score, simplified disease activity index, etc) does not always equate to the complete absence of inflammation as measured by new sensitive imaging techniques such as ultrasound (US) . There is evidence that imaging synovitis is frequently found...... in these patients and associated with adverse clinical and functional outcomes. This article reviews the data regarding remission, ultrasound imaging and outcomes in patients with RA to provide the background to a consensus statement from an international collaboration of ultrasonographers and rheumatologists who...

  19. After treat-to-target

    DEFF Research Database (Denmark)

    Wakefield, Richard J; D'Agostino, Maria Antonietta; Naredo, Esperanza

    2012-01-01

    have recently formed a research network--the Targeted Ultrasound Initiative (TUI) group. The statement proposes that targeting therapy to PD activity provides superior outcomes compared with treating to clinical targets alone and introduces the rationale for a new randomised trial using targeted...... defined by clinical remission criteria (disease activity score, simplified disease activity index, etc) does not always equate to the complete absence of inflammation as measured by new sensitive imaging techniques such as ultrasound (US) . There is evidence that imaging synovitis is frequently found...... in these patients and associated with adverse clinical and functional outcomes. This article reviews the data regarding remission, ultrasound imaging and outcomes in patients with RA to provide the background to a consensus statement from an international collaboration of ultrasonographers and rheumatologists who...

  20. Targeted therapy for pediatric glioma

    NARCIS (Netherlands)

    Olow, A.K.

    2015-01-01

    This thesis assesses molecular underpinnings of responses to promising targeted agents for pediatric tumors of Central Nervous System (CNS), incorporating preclinical testing of novel and translatable combination therapies to define the best therapy for each tumor cell specific molecular aberration.

  1. Physics of Automatic Target Recognition

    CERN Document Server

    Sadjadi, Firooz

    2007-01-01

    Physics of Automatic Target Recognition addresses the fundamental physical bases of sensing, and information extraction in the state-of-the art automatic target recognition field. It explores both passive and active multispectral sensing, polarimetric diversity, complex signature exploitation, sensor and processing adaptation, transformation of electromagnetic and acoustic waves in their interactions with targets, background clutter, transmission media, and sensing elements. The general inverse scattering, and advanced signal processing techniques and scientific evaluation methodologies being used in this multi disciplinary field will be part of this exposition. The issues of modeling of target signatures in various spectral modalities, LADAR, IR, SAR, high resolution radar, acoustic, seismic, visible, hyperspectral, in diverse geometric aspects will be addressed. The methods for signal processing and classification will cover concepts such as sensor adaptive and artificial neural networks, time reversal filt...

  2. National Ignition Facility Target Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-10-05

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This

  3. Theoretical aspects of inflation targeting

    Directory of Open Access Journals (Sweden)

    Obradović Jelena

    2014-01-01

    Full Text Available Inflation targeting is one of the possible strategies used by central banks during conducting monetary policy. The basic characteristics, advantages and disadvantages of inflation targeting will be presented in this paper. The focus is on the the presentation and interpretation of the understanding of this strategy from the perspective of monetarist and Keynesian theory, the theory of rational expectations, and methodological analysis of the strategy in light of the game theory using payoff matrix.

  4. Targeted immunotherapy in Hodgkin lymphoma

    DEFF Research Database (Denmark)

    Hutchings, Martin

    2015-01-01

    In this issue of Blood, Rothe et al introduce a new principle of targeted Hodgkin lymphoma (HL) immunotherapy in their report from a phase 1 study of the bispecific anti-CD30/CD16A antibody construct AFM13.......In this issue of Blood, Rothe et al introduce a new principle of targeted Hodgkin lymphoma (HL) immunotherapy in their report from a phase 1 study of the bispecific anti-CD30/CD16A antibody construct AFM13....

  5. Targeting the nuclear RNA exosome

    DEFF Research Database (Denmark)

    Meola, Nicola; Jensen, Torben Heick

    2017-01-01

    Centrally positioned in nuclear RNA metabolism, the exosome deals with virtually all transcript types. This 3'-5' exo- and endo-nucleolytic degradation machine is guided to its RNA targets by adaptor proteins that enable substrate recognition. Recently, the discovery of the 'Poly(A) tail exosome...... targeting (PAXT)' connection as an exosome adaptor to human nuclear polyadenylated transcripts has relighted the interest of poly(A) binding proteins (PABPs) in both RNA productive and destructive processes....

  6. 109Pd labeled 5,10,15,20-tetrakis[4-carboxymethyleneoxyphenyl]porphyrin: a potential agent for targeted tumor therapy.

    Science.gov (United States)

    Das, Tapas; Chakraborty, Sudipta; Sarma, H D; Banerjee, Sharmila

    2012-10-01

    Radiolabeled porphyrin derivatives could be envisaged as potential agents for targeted tumor therapy owing to the inherent tumor accumulation property exhibited by porphyrins. However, to achieve adequately high tumor accumulation and retention therein along with fast clearance from all non-target organs, an optimum balance between the hydrophilicity and lipophilicity must be achieved. Based on our prior experiences of working with (109)Pd-labeled porphyrins with variable lipophilicity and hydrophilicity, we have envisioned a suitable porphyrin derivative which could be expected to have the required balance between lipophilicity and hydrophilicity when complexed with (109)Pd. Towards this, 5,10,15,20- tetrakis[4-carboxymethyleneoxyphenyl]porphyrin (PHBEPH) was synthesized, radiolabeled with (109)Pd and its biological behavior in small animal model was studied. The porphyrin derivative was synthesized and characterized following the reported procedure and radiolabeled with (109)Pd [E β(max) = 1.12 MeV, E γ = 88 keV (3.6%), T1/2 = 13.7 h], which was produced by the thermal neutron bombardment on enriched (98% in (108)Pd) metallic Pd target at a flux of 3x1013 n/cm2.s for 3 d. Biological behavior of the radiolabeled agent was studied by biodistribution studies in Swiss mice bearing fibrosarcoma tumors. (109)Pd was produced with a specific activity of ∼1.85 GBq/mg (50 mCi/mg) and radionuclidic purity of 100%. (109)Pd complex of the synthesized porphyrin derivative was prepared with excellent radiochemical purity ( > 98%) and the complex was observed to exhibit Log P value of -1.29. Biodistribution studies revealed good tumor uptake [(3.55±0.49)% injected activity (IA)/g] within 30 min post-injection (p.i.) and retention therein till 24 h [(2.56±0.25)% IA)/g], upto which the study was continued. The complex exhibited fast clearance from the non-target organs with favorable tumor/blood and tumor/muscle ratios [(5.09±0.18)% and (284.44±3.25)% at 24 h p.i.]. The

  7. The Bering Autonomous Target Detection

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Denver, Troelz; Betto, Maurizio

    2003-01-01

    An autonomous asteroid target detection and tracking method has been developed. The method features near omnidirectionality and focus on high speed operations and completeness of search of the near space rather than the traditional faint object search methods, employed presently at the larger...... telescopes. The method has proven robust in operation and is well suited for use onboard spacecraft. As development target for the method and the associated instrumentation the asteroid research mission Bering has been used. Onboard a spacecraft, the autonomous detection is centered around the fully...... autonomous star tracker the Advanced Stellar Compass (ASC). One feature of this instrument is that potential targets are registered directly in terms of date, right ascension, declination, and intensity, which greatly facilitates both tracking search and registering. Results from ground and inflight tests...

  8. Pharmacogenomics of GPCR Drug Targets

    DEFF Research Database (Denmark)

    Hauser, Alexander Sebastian; Chavali, Sreenivas; Masuho, Ikuo

    2017-01-01

    Natural genetic variation in the human genome is a cause of individual differences in responses to medications and is an underappreciated burden on public health. Although 108 G-protein-coupled receptors (GPCRs) are the targets of 475 (∼34%) Food and Drug Administration (FDA)-approved drugs...... and account for a global sales volume of over 180 billion US dollars annually, the prevalence of genetic variation among GPCRs targeted by drugs is unknown. By analyzing data from 68,496 individuals, we find that GPCRs targeted by drugs show genetic variation within functional regions such as drug......- and effector-binding sites in the human population. We experimentally show that certain variants of μ-opioid and Cholecystokinin-A receptors could lead to altered or adverse drug response. By analyzing UK National Health Service drug prescription and sales data, we suggest that characterizing GPCR variants...

  9. INFLATION TARGETING IN EASTERN EUROPE

    Directory of Open Access Journals (Sweden)

    Laurian Lungu

    2006-05-01

    Full Text Available This paper addresses the inflation targeting approach in three transition economies, namely Hungary, Poland and the Czech Republic with the use of Taylor rules as benchmarks. The three economies considered have been successful at achieving disinflation, but deviations of inflation from its target have been persistent in all cases. Except for the Czech Republic, deviations from the Taylor rule are large and persistent, with Hungary displaying the largest fluctuations. Polish interest rates have consistently exceeded those suggested by the Taylor rule and given the prevalence of high unemployment, these undershootings do not augur well for the stability of monetary policy. Finally, the behaviour of Czech interest rates can be remarkably captured by the simple Taylor rule proposed in this paper, suggesting that the Czech National Bank has been the most successful at stabilising inflation and output around their target levels.

  10. Targeting Angiogenesis in Childhood Sarcomas

    Directory of Open Access Journals (Sweden)

    Hemant K. Bid

    2011-01-01

    Full Text Available Angiogenesis and vasculogenesis constitute two processes in the formation of new blood vessels and are essential for progression of solid tumors. Consequently, targeting angiogenesis, and to a lesser extent vasculogenesis, has become a major focus in cancer drug development. Angiogenesis inhibitors are now being tested in pediatric populations whereas inhibitors of vasculogenesis are in an earlier stage of development. Despite the initial enthusiasm for targeting angiogenesis for treatment of cancer, clinical trials have shown only incremental increases in survival, and agents have been largely cytostatic rather than inducing tumor regressions. Consequently, the role of such therapeutic approaches in the context of curative intent for childhood sarcomas is less clear. Here we review the literature on blood vessel formation in sarcomas with a focus on pediatric sarcomas and developments in targeting angiogenesis for treatment of these rare cancers.

  11. Ribosome Assembly as Antimicrobial Target

    Directory of Open Access Journals (Sweden)

    Rainer Nikolay

    2016-05-01

    Full Text Available Many antibiotics target the ribosome and interfere with its translation cycle. Since translation is the source of all cellular proteins including ribosomal proteins, protein synthesis and ribosome assembly are interdependent. As a consequence, the activity of translation inhibitors might indirectly cause defective ribosome assembly. Due to the difficulty in distinguishing between direct and indirect effects, and because assembly is probably a target in its own right, concepts are needed to identify small molecules that directly inhibit ribosome assembly. Here, we summarize the basic facts of ribosome targeting antibiotics. Furthermore, we present an in vivo screening strategy that focuses on ribosome assembly by a direct fluorescence based read-out that aims to identify and characterize small molecules acting as primary assembly inhibitors.

  12. Progress with developing a target for magnetized target fusion

    Energy Technology Data Exchange (ETDEWEB)

    Wysocki, F.J.; Chrien, R.E.; Idzorek, G.; Oona, H.; Whiteson, D.O.; Kirkpatrick, R.C.; Lindemuth, I.R.; Sheehey, P.T.

    1997-09-01

    Magnetized Target Fusion (MTF) is an approach to fusion where a preheated and magnetized plasma is adiabatically compressed to fusion conditions. Successful MTF requires a suitable initial target plasma with an embedded magnetic field of at least 5 T in a closed-field-line topology, a density of roughly 10{sup 18} cm{sup {minus}3}, a temperature of at least 50 eV, and must be free of impurities which would raise radiation losses. Target plasma generation experiments are underway at Los Alamos National Laboratory using the Colt facility; a 0.25 MJ, 2--3 {micro}s rise-time capacitor bank. The goal of these experiments is to demonstrate plasma conditions meeting the minimum requirements for a MTF initial target plasma. In the first experiments, a Z-pinch is produced in a 2 cm radius by 2 cm high conducting wall using a static gas-fill of hydrogen or deuterium gas in the range of 0.5 to 2 torr. Thus far, the diagnostics include an array of 12 B-dot probes, framing camera, gated OMA visible spectrometer, time-resolved monochrometer, filtered silicon photodiodes, neutron yield, and plasma-density interferometer. These diagnostics show that a plasma is produced in the containment region that lasts roughly 10 to 20 {micro}s with a maximum plasma density exceeding 10{sup 18} cm{sup {minus}3}. The experimental design and data are presented.

  13. Targeted Therapies for Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Idoroenyi Amanam

    2018-01-01

    Full Text Available Pancreatic cancer is the third leading cause of cancer related death and by 2030, it will be second only to lung cancer. We have seen tremendous advances in therapies for lung cancer as well as other solid tumors using a molecular targeted approach but our progress in treating pancreatic cancer has been incremental with median overall survival remaining less than one year. There is an urgent need for improved therapies with better efficacy and less toxicity. Small molecule inhibitors, monoclonal antibodies and immune modulatory therapies have been used. Here we review the progress that we have made with these targeted therapies.

  14. Harnessing off-target effects

    DEFF Research Database (Denmark)

    Saginc, Gaye; Voellmy, Franziska; Linding, Rune

    2017-01-01

    The 'off-targets' of a drug are often poorly characterized yet could be harnessed in the treatment of complex diseases. A recent study used a small-molecule screening in non-small-cell lung cancer to repurpose an FDA-approved ALK/IGF1R inhibitor and uncover its mechanism of action.......The 'off-targets' of a drug are often poorly characterized yet could be harnessed in the treatment of complex diseases. A recent study used a small-molecule screening in non-small-cell lung cancer to repurpose an FDA-approved ALK/IGF1R inhibitor and uncover its mechanism of action....

  15. The OPERA experiment Target Tracker

    CERN Document Server

    Adam, T; Borer, K.; Campagne, Jean-Eric; Con-Sen, N.; de La Taille, C.; Dick, N.; Dracos, M.; Gaudiot, G.; Goeltzenlichter, T.; Gornushkin, Y.; Grapton, J.-N.; Guyonnet, J.-L.; Hess, M.; Igersheim, R.; Janicsko Csathy, J.; Jollet, C.; Juget, F.; Kocher, H.; Krasnoperov, A.; Krumstein, Z.; Martin-Chassard, G.; Moser, U.; Nozdrin, A.; Olchevski, A.; Porokhovoi, S.; Raux, L.; Sadovski, A.; Schuler, J.; Schutz, H.-U.; Schwab, C.; Smolnikov, A.; Van Beek, G.; Vilain, P.; Walchli, T.; Wilquet, G.; Wurtz, J.

    2007-01-01

    The main task of the Target Tracker detector of the long baseline neutrino oscillation OPERA experiment is to locate in which of the target elementary constituents, the lead/emulsion bricks, the neutrino interactions have occurred and also to give calorimetric information about each event. The technology used consists in walls of two planes of plastic scintillator strips, one per transverse direction. Wavelength shifting fibres collect the light signal emitted by the scintillator strips and guide it to both ends where it is read by multi-anode photomultiplier tubes. All the elements used in the construction of this detector and its main characteristics are described.

  16. Target-Centric Network Modeling

    DEFF Research Database (Denmark)

    Mitchell, Dr. William L.; Clark, Dr. Robert M.

    In Target-Centric Network Modeling: Case Studies in Analyzing Complex Intelligence Issues, authors Robert Clark and William Mitchell take an entirely new approach to teaching intelligence analysis. Unlike any other book on the market, it offers case study scenarios using actual intelligence......, and collaborative sharing in the process of creating a high-quality, actionable intelligence product. The case studies reflect the complexity of twenty-first century intelligence issues by dealing with multi-layered target networks that cut across political, economic, social, technological, and military issues....... Working through these cases, students will learn to manage and evaluate realistic intelligence accounts....

  17. Speech-language pathologists' practices regarding assessment, analysis, target selection, intervention, and service delivery for children with speech sound disorders.

    Science.gov (United States)

    Mcleod, Sharynne; Baker, Elise

    2014-01-01

    A survey of 231 Australian speech-language pathologists (SLPs) was undertaken to describe practices regarding assessment, analysis, target selection, intervention, and service delivery for children with speech sound disorders (SSD). The participants typically worked in private practice, education, or community health settings and 67.6% had a waiting list for services. For each child, most of the SLPs spent 10-40 min in pre-assessment activities, 30-60 min undertaking face-to-face assessments, and 30-60 min completing paperwork after assessments. During an assessment SLPs typically conducted a parent interview, single-word speech sampling, collected a connected speech sample, and used informal tests. They also determined children's stimulability and estimated intelligibility. With multilingual children, informal assessment procedures and English-only tests were commonly used and SLPs relied on family members or interpreters to assist. Common analysis techniques included determination of phonological processes, substitutions-omissions-distortions-additions (SODA), and phonetic inventory. Participants placed high priority on selecting target sounds that were stimulable, early developing, and in error across all word positions and 60.3% felt very confident or confident selecting an appropriate intervention approach. Eight intervention approaches were frequently used: auditory discrimination, minimal pairs, cued articulation, phonological awareness, traditional articulation therapy, auditory bombardment, Nuffield Centre Dyspraxia Programme, and core vocabulary. Children typically received individual therapy with an SLP in a clinic setting. Parents often observed and participated in sessions and SLPs typically included siblings and grandparents in intervention sessions. Parent training and home programs were more frequently used than the group therapy. Two-thirds kept up-to-date by reading journal articles monthly or every 6 months. There were many similarities with

  18. TARGET Imbalances at Record Levels

    DEFF Research Database (Denmark)

    Hallett, Andrew Hughes

    TARGET is the payments system for making settlements between euro area economies and five other EU economies. Cross-border transactions generate claims/surpluses and liabilities/deficits among national central banks which “net out” for the system as a whole. These imbalances are manageable in rel...

  19. Targeted nanoparticles for colorectal cancer

    DEFF Research Database (Denmark)

    Cisterna, Bruno A.; Kamaly, Nazila; Choi, Won Il

    2016-01-01

    Colorectal cancer (CRC) is highly prevalent worldwide, and despite notable progress in treatment still leads to significant morbidity and mortality. The use of nanoparticles as a drug delivery system has become one of the most promising strategies for cancer therapy. Targeted nanoparticles could...

  20. Communicating to heterogeneous target groups

    DEFF Research Database (Denmark)

    Pedersen, Karsten

    very often have to communicate to rather heterogeneous target groups that have little more in common than a certain geographical habitat. That goes against most schoolbook teaching in the field of communication, but is none the less the terms with which that kind of communication has to live...

  1. Emerging targets in treating pain.

    Science.gov (United States)

    Chang, David S; Raghavan, Rahul; Christiansen, Sandy; Cohen, Steven P

    2015-08-01

    To provide an overview on drug targets and emerging pharmacological treatment options for chronic pain. Chronic pain poses an enormous socioeconomic burden for the more than 30% of people who suffer from it, costing over $600 billion per year in the USA. In recent years, there has been a surge in preclinical and clinical research endeavors to try to stem this epidemic. Preclinical studies have identified a wide array of potential targets, with some of the most promising translational research being performed on novel opioid receptors, cannabinoid receptors, selective ion channel blockers, cytokine inhibitors, nerve growth factor inhibitors, N-methyl-D-aspartate receptor antagonists, glial cell inhibitors, and bisphosphonates. There are many obstacles for the development of effective medications to treat chronic pain, including the inherent challenges in identifying pathophysiological mechanisms, the overlap and multiplicity of pain pathways, and off-target adverse effects stemming from the ubiquity of drug target receptor sites and the lack of highly selective receptor ligands. Despite these barriers, the number and diversity of potential therapies have continued to grow, to include disease-modifying and individualized drug treatments.

  2. Tumor targeting via integrin ligands

    Directory of Open Access Journals (Sweden)

    Udaya Kiran eMarelli

    2013-08-01

    Full Text Available Selective and targeted delivery of drugs to tumors is a major challenge for an effective cancer therapy and also to overcome the side effects associated with current treatments. Overexpression of various receptors on tumor cells is a characteristic structural and biochemical aspect of tumors and distinguishes them from physiologically normal cells. This abnormal feature is therefore suitable for selectively directing anticancer molecules to tumors by using ligands that can preferentially recognize such receptors. Several subtypes of integrin receptors that are crucial for cell adhesion, cell signaling, cell viability and motility have been shown to have an upregulated expression on cancer cells. Thus, ligands that recognize specific integrin subtypes represent excellent candidates to be conjugated to drugs or drug carrier systems and be targeted to tumors. In this regard, integrins recognizing the RGD cell adhesive sequence have been extensively targeted for tumor specific drug delivery. Here we review key recent examples on the presentation of RGD-based integrin ligands by means of distinct drug delivery systems, and discuss the prospects of such therapies to specifically target tumor cells.

  3. How are inflation targets set?

    Czech Academy of Sciences Publication Activity Database

    Horváth, R.; Matějů, Jakub

    -, č. 426 (2010), s. 1-35 ISSN 1211-3298 Grant - others:MŠk(CZ) SVV-2010-261801 Institutional research plan: CEZ:MSM0021620846 Keywords : inflation targeting * central bank * credibility Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp426.pdf

  4. High power neutron production targets

    Energy Technology Data Exchange (ETDEWEB)

    Wender, S. [Los Alamos National Lab., NM (United States)

    1996-06-01

    The author describes issues of concern in the design of targets and associated systems for high power neutron production facilities. The facilities include uses for neutron scattering, accelerator driven transmutation, accelerator production of tritium, short pulse spallation sources, and long pulse spallation sources. Each of these applications requires a source with different design needs and consequently different implementation in practise.

  5. Targeted nanoparticles for colorectal cancer

    DEFF Research Database (Denmark)

    Cisterna, Bruno A.; Kamaly, Nazila; Choi, Won Il

    2016-01-01

    Colorectal cancer (CRC) is highly prevalent worldwide, and despite notable progress in treatment still leads to significant morbidity and mortality. The use of nanoparticles as a drug delivery system has become one of the most promising strategies for cancer therapy. Targeted nanoparticles could ...

  6. Targeted Therapies in Endometrial Cancer

    Directory of Open Access Journals (Sweden)

    Selen Dogan

    2014-04-01

    Full Text Available Endometrial cancer is the most common genital cancer in developed world. It is generally diagnosed in early stage and it has a favorable prognosis. However, advanced staged disease and recurrences are difficult to manage. There are some common genetic alterations related to endometrial carcinogenesis in similar fashion to other cancers. Personalized medicine, which means selection of best suited treatment for an individual, has gain attention in clinical care of patients in recent years. Targeted therapies were developed as a part of personalized or %u201Ctailored%u201D medicine and specifically acts on a target or biologic pathway. There are quite a number of molecular alteration points in endometrial cancer such as PTEN tumor suppressor genes, DNA mismatch repair genes, PI3K/AKT/mTOR pathway and p53 oncogene which all might be potential candidates for tailored targeted therapy. In recent years targeted therapies has clinical application in ovarian cancer patients and in near future with the advent of new agents these %u201Ctailored%u201D drugs will be in market for routine clinical practice in endometrial cancer patients, in primary disease and recurrences as well.

  7. The Automatic Measurement of Targets

    DEFF Research Database (Denmark)

    Höhle, Joachim

    1997-01-01

    The automatic measurement of targets is demonstrated by means of a theoretical example and by an interactive measuring program for real imagery from a réseau camera. The used strategy is a combination of two methods: the maximum correlation coefficient and the correlation in the subpixel range...

  8. Polarized Scintillating Targets at Psi

    Science.gov (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Mango, S.

    2001-02-01

    Scintillating polarized targets are now routinely available: blocks of 18×18×5 mm scintillating organic polymer, doped with TEMPO, polarized dynamically in a field of 2.5 T in a vertical 3He-4He dilution refrigerator. A 19 mm diameter plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat.

  9. Aptamers for Targeted Drug Delivery

    Directory of Open Access Journals (Sweden)

    Partha Ray

    2010-05-01

    Full Text Available Aptamers are a class of therapeutic oligonucleotides that form specific three-dimensional structures that are dictated by their sequences. They are typically generated by an iterative screening process of complex nucleic acid libraries employing a process termed Systemic Evolution of Ligands by Exponential Enrichment (SELEX. SELEX has traditionally been performed using purified proteins, and cell surface receptors may be challenging to purify in their properly folded and modified conformations. Therefore, relatively few aptamers have been generated that bind cell surface receptors. However, improvements in recombinant fusion protein technology have increased the availability of receptor extracellular domains as purified protein targets, and the development of cell-based selection techniques has allowed selection against surface proteins in their native configuration on the cell surface. With cell-based selection, a specific protein target is not always chosen, but selection is performed against a target cell type with the goal of letting the aptamer choose the target. Several studies have demonstrated that aptamers that bind cell surface receptors may have functions other than just blocking receptor-ligand interactions. All cell surface proteins cycle intracellularly to some extent, and many surface receptors are actively internalized in response to ligand binding. Therefore, aptamers that bind cell surface receptors have been exploited for the delivery of a variety of cargoes into cells. This review focuses on recent progress and current challenges in the field of aptamer-mediated delivery.

  10. Targeted Advertising and Social Status

    NARCIS (Netherlands)

    N. Vikander (Nick)

    2010-01-01

    textabstractThis paper shows how a firm can use non-targeted advertising to exploit consumers' desire for social status. A monopolist sells multiple varieties of a good to consumers who each care about what others believe about his wealth. Advertising allows consumers both to buy different varieties

  11. Polarimetric imaging of underwater targets

    Science.gov (United States)

    Gilerson, Alex; Carrizo, Carlos; Tonizzo, Alberto; Ibrahim, Amir; El-Habashi, Ahmed; Foster, Robert; Ahmed, Samir

    2013-06-01

    Underwater imaging is challenging because of the significant attenuation of light due to absorption and scattering of light in water. Using polarization properties of light is one of the options for improving image quality. We present results of imaging of a polarized target in open ocean (Curacao) and coastal (NY Bight) waters. The target in the shape of a square is divided into several smaller squares, each of which is covered with a polarizing film with different polarization orientations or transmission coefficients was placed on a mirror and imaged under water by a green-band full-Stokes polarimetric video camera at the full range of azimuth angles against the Sun. The values of the Stokes vector components from the images are compared with the modeled image of the target using radiative transfer code for the atmosphere-ocean system combined with the simple imaging model. It is shown that even in clear water the impact of the water body on the polarized underwater image is very significant and retrieval of target polarization characteristics from the image is extremely challenging.

  12. Target selection for direct marketing.

    NARCIS (Netherlands)

    Bult, Jan Roelf

    1993-01-01

    In this thesis we concentrated on the use ol direct mail for targeting potential buyers. The major characteristics that influences the success of a plomotional direct mail campaign are the of-fbr,the communication elements, the timing or sequence of these communication elements, and the list of

  13. Uranium briquettes for irradiation target

    Energy Technology Data Exchange (ETDEWEB)

    Saliba-Silva, Adonis Marcelo; Garcia, Rafael Henrique Lazzari; Martins, Ilson Carlos; Carvalho, Elita Fontenele Urano de; Durazzo, Michelangelo, E-mail: saliba@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Direct irradiation on targets inside nuclear research or multiple purpose reactors is a common route to produce {sup 99}Mo-{sup 99m}Tc radioisotopes. Nevertheless, since the imposed limits to use LEU uranium to prevent nuclear armament production, the amount of uranium loaded in target meats has physically increased and new processes have been proposed for production. Routes using metallic uranium thin film and UAl{sub x} dispersion have been used for this purpose. Both routes have their own issues, either by bringing difficulties to disassemble the aluminum case inside hot cells or by generating great amount of alkaline radioactive liquid rejects. A potential route might be the dispersion of powders of LEU metallic uranium and nickel, which are pressed as a blend inside a die and followed by pulse electroplating of nickel. The electroplating provides more strength to the briquettes and creates a barrier for gas evolution during neutronic disintegration of {sup 235}U. A target briquette platted with nickel encapsulated in an aluminum case to be irradiated may be an alternative possibility to replace other proposed targets. This work uses pulse Ni-electroplating over iron powder briquette to simulate the covering of uranium by nickel. The following parameters were applied 10 times for each sample: 900Hz, -0.84A/square centimeters with duty cycle of 0.1 in Watts Bath. It also presented the optical microscopy analysis of plated microstructure section. (author)

  14. Collisional disruptions of rotating targets

    Science.gov (United States)

    Ševeček, Pavel; Broz, Miroslav

    2017-10-01

    Collisions are key processes in the evolution of the Main Asteroid Belt and impact events - i.e. target fragmentation and gravitational reaccumulation - are commonly studied by numerical simulations, namely by SPH and N-body methods. In our work, we extend the previous studies by assuming rotating targets and we study the dependence of resulting size-distributions on the pre-impact rotation of the target. To obtain stable initial conditions, it is also necessary to include the self-gravity already in the fragmentation phase which was previously neglected.To tackle this problem, we developed an SPH code, accelerated by SSE/AVX instruction sets and parallelized. The code solves the standard set of hydrodynamic equations, using the Tillotson equation of state, von Mises criterion for plastic yielding and scalar Grady-Kipp model for fragmentation. We further modified the velocity gradient by a correction tensor (Schäfer et al. 2007) to ensure a first-order conservation of the total angular momentum. As the intact target is a spherical body, its gravity can be approximated by a potential of a homogeneous sphere, making it easy to set up initial conditions. This is however infeasible for later stages of the disruption; to this point, we included the Barnes-Hut algorithm to compute the gravitational accelerations, using a multipole expansion of distant particles up to hexadecapole order.We tested the code carefully, comparing the results to our previous computations obtained with the SPH5 code (Benz and Asphaug 1994). Finally, we ran a set of simulations and we discuss the difference between the synthetic families created by rotating and static targets.

  15. Cellular Targets of Dietary Polyphenol Resveratrol

    National Research Council Canada - National Science Library

    Wu, Joseph M

    2006-01-01

    To test the hypothesis that resveratrol, a grape derived polyphenol, exerts its chemopreventive properties against prostate cancer by interacting with specific cellular targets, denoted resveratrol targeting proteins (RTPs...

  16. North Pacific Targets Program Environmental Assessment

    National Research Council Canada - National Science Library

    2001-01-01

    .... The STPO would provide the Strategic Target System launch vehicle for strategic target launch services from Kodiak Launch Complex, Kodiak Island, Alaska, a commercial rocket launch facility operated...

  17. Targeted nanosystems: Advances in targeted dendrimers for cancer therapy.

    Science.gov (United States)

    Yang, Hu

    2016-02-01

    Dendrimers possess discrete highly compact nanostructures constituted of successive branched layers. Soon after the inception of dendrimers, recognition of their tunable structures and biologically favorable properties provoked a great enthusiasm in delving deeply into the utility of dendrimers for biomedical and pharmaceutical applications. One of the most important nanotechnology applications is the development of nanomedicines for targeted cancer therapies. Tremendous success in targeted therapies has been achieved with the use of dendrimer-based nanomedicines. This article provides a concise review on latest advances in the utility of dendrimers in immunotherapies and hormone therapies. Much basic and clinical research has been done since the invention of dendrimers, which are highly branched nano-sized molecules with the ability to act as carriers in nanomedicine. In this concise review article, the authors highlighted the current use of dendrimers in immunotherapies and hormone therapies in the fight against cancers. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Targeted expression of redesigned and codon optimised synthetic gene leads to recrystallisation inhibition and reduced electrolyte leakage in spring wheat at sub-zero temperatures.

    Science.gov (United States)

    Khanna, Harjeet K; Daggard, Grant E

    2006-12-01

    Antifreeze proteins (AFPs) adsorb to ice crystals and inhibit their growth, leading to non-colligative freezing point depression. Crops like spring wheat, that are highly susceptible to frost damage, can potentially be made frost tolerant by expressing AFPs in the cytoplasm and apoplast where ice recrystallisation leads to cellular damage. The protein sequence for HPLC-6 alpha-helical antifreeze protein from winter flounder was rationally redesigned after removing the prosequences in the native protein. Wheat nuclear gene preferred amino acid codons were used to synthesize a recombinant antifreeze gene, rAFPI. Antifreeze protein was targeted to the apoplast using a Murine leader peptide sequence from the mAb24 light chain or retained in the endoplasmic reticulum using C-terminus KDEL sequence. The coding sequences were placed downstream of the rice Actin promoter and Actin-1 intron and upstream of the nopaline synthase terminator in the plant expression vectors. Transgenic wheat lines were generated through micro projectile bombardment of immature embryos of spring wheat cultivar Seri 82. Levels of antifreeze protein in the transgenic lines without any targeting peptide were low (0.06-0.07%). The apoplast-targeted protein reached a level of 1.61% of total soluble protein, 90% of which was present in the apoplast. ER-retained protein accumulated in the cells at levels up to 0.65% of total soluble proteins. Transgenic wheat line T-8 with apoplast-targeted antifreeze protein exhibited the highest levels of antifreeze activity and provided significant freezing protection even at temperatures as low as -7 degrees C.

  19. Emerging targets in human lymphoma: targeting the MYD88 mutation

    Directory of Open Access Journals (Sweden)

    Wang JQ

    2013-08-01

    Full Text Available James Q Wang,* Yogesh S Jeelall,* Keisuke Horikawa* Department of Immunology, The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia *All authors contributed equally to this manuscript Abstract: B cell neoplasms co-opt the molecular machinery of normal B cells for their survival. Technological advances in cancer genomics has significantly contributed to uncovering the root cause of aggressive lymphomas, revealing a previously unknown link between TLR signaling and B cell neoplasm. Recurrent oncogenic mutations in MYD88 have been found in 39% of the activated B cell-like subtype of diffuse large B cell lymphoma (ABC DLBCL. Interestingly, 29% of ABC DLBCL have a single amino acid substitution of proline for the leucine at position 265 (L265P, and the exact same variant has also been identified in a number of lymphoid malignancies. The MYD88 L265P variant was recently identified in 90% of Wadenstrom's macroglobulinemia patients. These recent developments warrant the need for novel diagnostic tools as well as targeted therapeutics. In this review, we discuss the physiological functions of MYD88 and focus on its role in B cell lymphomas, evaluating the potential for targeting oncogenic MYD88 in lymphoma. Keywords: MYD88, L265P mutation, lymphoma, targeted therapy

  20. Targeting an efficient target-to-target interval for P300 speller brain–computer interfaces

    Science.gov (United States)

    Sellers, Eric W.; Wang, Xingyu

    2013-01-01

    Longer target-to-target intervals (TTI) produce greater P300 event-related potential amplitude, which can increase brain–computer interface (BCI) classification accuracy and decrease the number of flashes needed for accurate character classification. However, longer TTIs requires more time for each trial, which will decrease the information transfer rate of BCI. In this paper, a P300 BCI using a 7 × 12 matrix explored new flash patterns (16-, 18- and 21-flash pattern) with different TTIs to assess the effects of TTI on P300 BCI performance. The new flash patterns were designed to minimize TTI, decrease repetition blindness, and examine the temporal relationship between each flash of a given stimulus by placing a minimum of one (16-flash pattern), two (18-flash pattern), or three (21-flash pattern) non-target flashes between each target flashes. Online results showed that the 16-flash pattern yielded the lowest classification accuracy among the three patterns. The results also showed that the 18-flash pattern provides a significantly higher information transfer rate (ITR) than the 21-flash pattern; both patterns provide high ITR and high accuracy for all subjects. PMID:22350331

  1. Newer targeted therapies in psoriasis

    Directory of Open Access Journals (Sweden)

    Sujay Khandpur

    2013-01-01

    Full Text Available Psoriasis is a common, chronic, inflammatory skin disease that can have a significant impact on the quality of life of those who are afflicted due to chronicity of the disease and frequent remissions and relapses. Many available systemic therapies, however, are unsuitable for chronic administration due to the risk of cumulative toxicity. Recent advances in the understanding of the pathophysiology of psoriasis have led to the development of new, genetically engineered, targeted therapies for this disease. These include approaches targeting antigen presentation and co-stimulation, T-cell activation and leukocyte adhesion, action on pro-inflammatory mediators, and modulating the cytokine balance. Although only preliminary data are available so far and there is limited data supporting their use, these trials contribute to a further understanding of the disease and will eventually lead to new therapeutic options for psoriasis.

  2. Moulding calixarenes for biomacromolecule targeting.

    Science.gov (United States)

    Giuliani, Marta; Morbioli, Ilaria; Sansone, Francesco; Casnati, Alessandro

    2015-09-28

    After their successful use as a preorganized platform for the preparation of receptors for metal ions and small neutral molecules over the last 15 years, calixarenes are enjoying a renaissance of popularity as scaffolds for ligands that are able to efficiently and selectively target macromolecules such as proteins/enzymes, nucleic acids and lipids. This feature article summarizes the peculiar factors characterizing the calixarene structure and properties, as well as outlines the main rules that can be used to turn such macrocycles into efficient and successful ligands for these classes of biomacromolecules. Factors that affect the multivalent properties of calixarenes, such as the size, conformation and stereochemical presentation of binding groups or their amphiphilicity and hybrid character, are described in detail with the use of a few selected examples from the literature. Perspectives and applications of these ligands in bionanotechnology and nanomedicine, such as protein sensing and inhibition, gene-delivery, targeted drug-delivery and cell imaging, are also discussed.

  3. Swimbladder on Fish Target Strength

    Directory of Open Access Journals (Sweden)

    Sunardi

    2008-08-01

    Full Text Available This paper discusses of target strength (TS for the Selar boops (Oxeye scad and Megalaspis cordyla (Torpedo scad, the most commercially fish in Malaysia. TS can be determined from in situ measurements and acoustic calculation of fish model. TS value, depth, and position (x-y-z of targeted fish can be viewed from echogram using FQ-80 Analyzer by in situ measurement. X-ray imaged can be deployed to develop the acoustic fish model. The percentage of length and upper surface area for swimbladder to body fish of Selar boops more than Megalaspis cordyla can be measured after X-ray process. The percentage of width and volume of swimbladders to its each body are no significantly difference for both fish. These data of swimbladder physic support the result of in situ measurement which TS of Megalaspis cordyla stronger Selar boops.

  4. Recurring Utterances - Targeting a Breakthrough

    Directory of Open Access Journals (Sweden)

    Jacqueline Stark

    2014-05-01

    The most interesting phenomenon is KB’s production of words from former sessions indicating that they are still ‘active’ and the production of completely novel incorrect words. The observable features indicate that immediate auditory processing is possible in the form of repeating target words. However, as soon as KB must retrieve information from the (semantic lexicon, even after being able to correctly ‘repeat’ the target word several times, he responds with a RU, perseveration, or paraphasia. Several of his productions can be characterized as aphasic confabulations which stem from a memory gap. Thus, although KB’s language impairment is severe, his responses across time indicate that step-by-step a breakthrough is being made.

  5. Remote moving target indication assessment

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1996-10-01

    The objective of this project was to design and test key components of a sensor to be used on remotely piloted vehicles, aircraft, or satellites for the detection of moving vehicles in cluttered backgrounds. The proposed sensor uses modern large-array focal planes to provide multiple infrared observations of moving targets and capable on-board computers to integrate multiple observations to detect moving targets in background clutter. This combination reduces the size, weight, and cost of the sensor to levels that can be flown on many small unmanned platforms. This effort selected the actual components, integrated them into a test bed, tested the performance of the sensor against realistic generated scenes, and designed a proof-of-concept prototype.

  6. Targeting vaccines to dendritic cells

    DEFF Research Database (Denmark)

    Foged, Camilla; Sundblad, Anne; Hovgaard, Lars

    2002-01-01

    to be far superior to that of B-cells and macrophages. DC are localized at strategic places in the body at sites used by pathogens to enter the organism, and are thereby in an optimal position to capture antigens. In general, vaccination strategies try to mimic the invasiveness of the pathogens. DC...... are considered to play a central role for the provocation of primary immune responses by vaccination. A rational way of improving the potency and safety of new and already existing vaccines could therefore be to direct vaccines specifically to DC. There is a need for developing multifunctional vaccine drug...... delivery systems (DDS) with adjuvant effect that target DC directly and induce optimal immune responses. This paper will review the current knowledge of DC physiology as well as the progress in the field of novel vaccination strategies that directly or indirectly aim at targeting DC....

  7. A novel [{sup 109}Pd] palladium labeled porphyrin for possible use in targeted radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Das, T.; Chakraborty, S.; Banerjee, S. [Bhabha Atomic Research Centre, Mumbai (India). Radiopharmaceuticals Div.; Sarma, H.D. [Bhabha Atomic Research Centre, Mumbai (India). Radiation Biology and Health Sciences Div.

    2008-07-01

    The preferential accumulation of porphyrins in malignant tumor cells has been adequately documented. Hence, porphyrin derivatives radiolabeled with a suitable therapeutic radionuclide could be envisaged as potential agents for targeted tumor radiotherapy. Working in this direction, we have radiolabeled a porphyrin derivative, namely, 5,10,15,20-tetrakis[3,4-bis(carboethoxymethyleneoxy)phenyl]-porphyrin, synthesized in-house, with {sup 109}Pd [E{sub {beta}}{sub (max)} = 1.12 MeV, E{sub {gamma}} = 88 keV (3.6%), T{sub 1/2} = 13.7 h]. The envisaged rationale towards designing of this agent is based on the assumption that {sup 109}Pd would complex with the tetrapyrrole donor array constituting the porphyrin core, thereby providing a highly stable chelated complex, and the peripheral ester groups would impart optimum lipophilicity needed for sufficiently high tumor accumulation and retention therein. {sup 109}Pd was produced with a specific activity of {proportional_to} 1.85 GBq/mg and radionuclidic purity of 100% by the thermal neutron bombardment of enriched (98% in {sup 108}Pd) metallic Pd target at a flux of 3 x 10{sup 13} n/cm{sup 2} s{sup 1} for 3 d. The porphyrin derivative was synthesized by a multi-step reaction and characterized by normal spectroscopic techniques. {sup 109}Pd complex of the synthesized porphyrin derivative was prepared with excellent radiochemical purity (> 98%) and the complex was observed to be stable up to 24 h at room temperature. Biodistribution studies carried out in Swiss mice bearing fibrosarcoma tumors revealed good tumor uptake [(5.28 {+-} 1.46)% injected activity (IA)/g] within 30 min post-injection (p.i.). The complex exhibited favorable tumor/blood and tumor/muscle ratios [1.69 {+-} 0.23 and 5.00 {+-} 1.54, respectively at 3 h p.i.], albeit with high liver uptake throughout the time of study (> 20% IA). (orig.)

  8. Poverty, inequality, and geographic targeting

    OpenAIRE

    Simler, Kenneth R.; Nhate, Virgulino

    2005-01-01

    "This paper applies small area estimation techniques to Mozambican data to develop high resolution (subdistrictlevel) poverty and inequality maps...The picture that emerges is one of considerable local-level economic heterogeneity, with the poor living alongside the nonpoor. Rather than finding stark pockets of intense poverty traps in one part of the country and a relative absence of poverty in other parts, the situation is much more nuanced. This suggests that targeting antipoverty efforts ...

  9. Targeting phenotypically tolerant Mycobacterium tuberculosis

    Science.gov (United States)

    Gold, Ben; Nathan, Carl

    2016-01-01

    While the immune system is credited with averting tuberculosis in billions of individuals exposed to Mycobacterium tuberculosis, the immune system is also culpable for tempering the ability of antibiotics to deliver swift and durable cure of disease. In individuals afflicted with tuberculosis, host immunity produces diverse microenvironmental niches that support suboptimal growth, or complete growth arrest, of M. tuberculosis. The physiological state of nonreplication in bacteria is associated with phenotypic drug tolerance. Many of these host microenvironments, when modeled in vitro by carbon starvation, complete nutrient starvation, stationary phase, acidic pH, reactive nitrogen intermediates, hypoxia, biofilms, and withholding streptomycin from the streptomycin-addicted strain SS18b, render M. tuberculosis profoundly tolerant to many of the antibiotics that are given to tuberculosis patients in a clinical setting. Targeting nonreplicating persisters is anticipated to reduce the duration of antibiotic treatment and rate of post-treatment relapse. Some promising drugs to treat tuberculosis, such as rifampicin and bedaquiline, only kill nonreplicating M. tuberculosis in vitro at concentrations far greater than their minimal inhibitory concentrations against replicating bacilli. There is an urgent demand to identify which of the currently used antibiotics, and which of the molecules in academic and corporate screening collections, have potent bactericidal action on nonreplicating M. tuberculosis. With this goal, we review methods of high throughput screening to target nonreplicating M. tuberculosis and methods to progress candidate molecules. A classification based on structures and putative targets of molecules that have been reported to kill nonreplicating M. tuberculosis revealed a rich diversity in pharmacophores. However, few of these compounds were tested under conditions that would exclude the impact of adsorbed compound acting during the recovery phase of

  10. Medium size polarised deuteron target

    Energy Technology Data Exchange (ETDEWEB)

    Kiselev, Yu.F.; Polyakov, V.V.; Kovalev, A.I.; Bunyatova, E.I.; Borisov, N.S.; Trautman, V.Yu.; Werner, K.; Kozlenko, N.G.

    1984-03-01

    A frozen polarised deuteron target based on ethanediol with a high percentage of deuterium is described. Analytical expressions for the NMR spectrum correction for non-linearity of the Q-meter are obtained and a method for the determination of the asymmetry is developed. Experimental results confirm the thermal mixing theory for deuteron and proton spin systems with a dipole-dipole reservoir of electron spins.

  11. Peptide-targeted polymer cancerostatics

    Czech Academy of Sciences Publication Activity Database

    Böhmová, Eliška; Pola, Robert

    2016-01-01

    Roč. 65, Suppl. 2 (2016), S153-S164 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : HPMA copolymers * tumor targeting * peptides Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.461, year: 2016 http://www.biomed.cas.cz/physiolres/pdf/65%20Suppl%202/65_S153.pdf

  12. Coherent Communications, Imaging and Targeting

    Energy Technology Data Exchange (ETDEWEB)

    Stappaerts, E; Baker, K; Gavel, D; Wilks, S; Olivier, S; Brase, J; Olivier, S; Brase, J

    2003-10-03

    Laboratory and field demonstration results obtained as part of the DARPA-sponsored Coherent Communications, Imaging and Targeting (CCIT) program are reviewed. The CCIT concept uses a Phase Conjugation Engine based on a quadrature receiver array, a hologram processor and a spatial light modulator (SLM) for high-speed, digital beam control. Progress on the enabling MEMS SLM, being developed by a consortium consisting of LLNL, academic institutions and small businesses, is presented.

  13. Theranostics Targeting Metastatic Breast Cancer

    Science.gov (United States)

    2016-10-01

    What opportunities for training and professional development has the project provided? Two graduate students and one postdoctoral research associate...hostile immune reaction toward FR-expressing tumors. A series of vaccinations with hapten fluorescein (EC90 vaccine ) admin- istrated with an adjuvant...FITC-conjugated (FITC is flu - orescein isothiocyanate) CA inhibitor acetalozamide (AAZ) targeted CA-IX positive cells (Kd = 12.6 nM). The biodistribution

  14. Targeting inflammation in metabolic syndrome.

    Science.gov (United States)

    Welty, Francine K; Alfaddagh, Abdulhamied; Elajami, Tarec K

    2016-01-01

    The metabolic syndrome (MetS) is comprised of a cluster of closely related risk factors, including visceral adiposity, insulin resistance, hypertension, high triglyceride, and low high-density lipoprotein cholesterol; all of which increase the risk for the development of type 2 diabetes and cardiovascular disease. A chronic state of inflammation appears to be a central mechanism underlying the pathophysiology of insulin resistance and MetS. In this review, we summarize recent research which has provided insight into the mechanisms by which inflammation underlies the pathophysiology of the individual components of MetS including visceral adiposity, hyperglycemia and insulin resistance, dyslipidemia, and hypertension. On the basis of these mechanisms, we summarize therapeutic modalities to target inflammation in the MetS and its individual components. Current therapeutic modalities can modulate the individual components of MetS and have a direct anti-inflammatory effect. Lifestyle modifications including exercise, weight loss, and diets high in fruits, vegetables, fiber, whole grains, and low-fat dairy and low in saturated fat and glucose are recommended as a first line therapy. The Mediterranean and dietary approaches to stop hypertension diets are especially beneficial and have been shown to prevent development of MetS. Moreover, the Mediterranean diet has been associated with reductions in total and cardiovascular mortality. Omega-3 fatty acids and peroxisome proliferator-activated receptor α agonists lower high levels of triglyceride; their role in targeting inflammation is reviewed. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone blockers comprise pharmacologic therapies for hypertension but also target other aspects of MetS including inflammation. Statin drugs target many of the underlying inflammatory pathways involved in MetS. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Targeting distress in rheumatic diseases

    OpenAIRE

    Vriezekolk, J.E.

    2011-01-01

    Psychological distress is highly prevalent in patients with rheumatic diseases. It is associated with a variety of negative outcomes, including pain, fatigue, disability, and maladaptive cognitive behavioural coping strategies. In this thesis, psychological distress was studied both as an outcome measure and as a therapeutic target in the context of multidisciplinary rehabilitation. The longitudinal role of coping in psychological distress was systematically reviewed, a questionnaire to asses...

  16. Novel therapies targeting vascular endothelium.

    Science.gov (United States)

    Tousoulis, Dimitris; Antoniades, Charalambos; Koumallos, Nikolaos; Marinou, Kyriakoula; Stefanadi, Elli; Latsios, George; Stefanadis, Christodoulos

    2006-01-01

    Endothelial dysfunction has been identified as a major mechanism involved in all the stages of atherogenesis. Evaluation of endothelial function seems to have a predictive role in humans, and therapeutic interventions improving nitric oxide bioavailability in the vasculature may improve the long-term outcome in healthy individuals, high-risk subjects, or patients with advanced atherosclerosis. Several therapeutic strategies are now available, targeting both the synthesis and oxidative inactivation of nitric oxide (NO) in human vasculature. Statins seem to be currently the most powerful category of these agents, improving endothelial function and decreasing cardiovascular risk after long-term administration. Other cardiovascular agents improving endothelial function in humans are angiotensin-converting enzyme inhibitors/angiotensin receptors blockers, which increase NO bioavailability by modifying the rennin-angiotensin-aldosterone system. Newer therapeutic approaches targeting endothelial dysfunction in specific disease states include insulin sensitizers, L-arginine (the substrate for endothelial NO synthase [eNOS]) as well as substances that target eNOS "coupling," such as folates or tetrahydrobiopterin. Although there are a variety of strategies to improve NO bioavailability in human endothelium, it is still unclear whether they have any direct benefit at a clinical level.

  17. Targeted gene flow for conservation.

    Science.gov (United States)

    Kelly, Ella; Phillips, Ben L

    2016-04-01

    Anthropogenic threats often impose strong selection on affected populations, causing rapid evolutionary responses. Unfortunately, these adaptive responses are rarely harnessed for conservation. We suggest that conservation managers pay close attention to adaptive processes and geographic variation, with an eye to using them for conservation goals. Translocating pre-adapted individuals into recipient populations is currently considered a potentially important management tool in the face of climate change. Targeted gene flow, which involves moving individuals with favorable traits to areas where these traits would have a conservation benefit, could have a much broader application in conservation. Across a species' range there may be long-standing geographic variation in traits or variation may have rapidly developed in response to a threatening process. Targeted gene flow could be used to promote natural resistance to threats to increase species resilience. We suggest that targeted gene flow is a currently underappreciated strategy in conservation that has applications ranging from the management of invasive species and their impacts to controlling the impact and virulence of pathogens. © 2015 Society for Conservation Biology.

  18. Targeted Treatment Options in Mastocytosis

    Directory of Open Access Journals (Sweden)

    Mélanie Vaes

    2017-07-01

    Full Text Available Mastocytosis refers to a heterogeneous group of disorders resulting from the clonal proliferation of abnormal mast cells and their accumulation in the skin (cutaneous mastocytosis when only in the skin, CM or in various organs (systemic mastocytosis, SM. This leads to a wide variety of clinical manifestations resulting from excessive mediator release in CM and benign forms of SM (indolent SM, ISM and from tissue mast cell infiltration causing multiorgan dysfunction and failure in more aggressive subtypes (aggressive SM, ASM, or mast cell leukemia. In addition, SM may be associated with hematological neoplasms (AHN. While treatment of ISM primarily aims at symptom management with anti-mediator therapies, cytoreductive and targeted therapies are needed to control the expansion of neoplastic mast cells in advanced forms of SM, in order to improve overall survival. Mast cell accumulation results from a gain-of-function mutation (mostly the D816V mutation within the KIT tyrosine kinase domain expressed by mast cells and additional genetic and epigenetic mutations may further determine the features of the disease (ASM and AHN. Consequently, tyrosine kinase inhibitors and targeted therapies directed against the oncogenic signaling machinery downstream of KIT are attractive therapeutic approaches. A better understanding of the relative contribution of these genetic and epigenetic events to the molecular pathogenesis of mastocytosis is of particular interest for the development of targeted therapies and therefore to better choose patient subgroups that would best benefit from a given therapeutic strategy.

  19. Unmanned Aircraft Systems (UAS) Sensor and Targeting

    Science.gov (United States)

    2010-07-27

    mission, a pre-determined number of different targets should be shuffled between the target locations in the array. Example targets for this subtest are...UNFOV Ultra Narrow Field of View UTM Universal Transverse Mercator VBLSS Video-Based Laser Scoring System VRT Vertical Reference Target WFOV

  20. Progress with developing a target for magnetized target fusion

    Energy Technology Data Exchange (ETDEWEB)

    Wysocki, F.J.; Chrien, B.E.; Idzorek, G.; Oona, H.; Whiteson, D.O.; Kirkpatrick, R.C.; Lindemuth, I.R.; Sheehey, P.T. [Los Alamos National Lab., NM (United States)

    1997-12-31

    Magnetized Target Fusion (MTF) is an approach to fusion where a preheated and magnetized plasma is adiabatically compressed to fusion conditions. Successful MTF requires a suitable initial target plasma with an embedded magnetic field of at least 5 T in a closed-field-line topology, a density of roughly 10{sup 18} cm{sup {minus}3}, a temperature of at least 50 eV, and must be free of impurities which would raise radiation losses. Target plasma generation experiments are underway at Los Alamos National Laboratory using the Colt facility; a 0.25 MJ, 2--3 {micro}s rise-time capacitor bank. In the first experiments, a Z-pinch is produced in a 2 cm radius by 2 cm high conducting wall using a static gas-fill of hydrogen or deuterium gas in the range of 0.5 to 2 torr. Follow-on experiments will use a frozen deuterium fiber along the axis (without a gas-fill). The diagnostics include B-dot probes, framing camera, gated OMA visible spectrometer, time-resolved monochrometer, silicon photodiodes, neutron yield, and plasma-density interferometer. Operation to date has been with drive current ranging from 0.8 MA to 1.9 MA. Optical diagnostics show that the plasma produced in the containment region lasts roughly 20 to 30 {micro}s, and the B-dot probes show a broad current-profile in the containment region. The experimental design and data will be presented.

  1. Targeted advertising, platform competition and privacy

    OpenAIRE

    Henk Kox; Bas Straathof; Gijsbert Zwart

    2014-01-01

    Targeted advertising can benefit consumers through lower prices for access to websites. Yet, if consumers dislike that websites collect their personal information, their welfare may go down. We study competition for consumers between websites that can show targeted advertisements. We find that more targeting increases competition and reduces the websites' profits, but yet in equilibrium websites choose maximum targeting as they cannot credibly commit to low targeting. A privacy protection pol...

  2. Hospitals: Soft Target for Terrorism?

    Science.gov (United States)

    De Cauwer, Harald; Somville, Francis; Sabbe, Marc; Mortelmans, Luc J

    2017-02-01

    In recent years, the world has been rocked repeatedly by terrorist attacks. Arguably, the most remarkable were: the series of four coordinated suicide plane attacks on September 11, 2001 on buildings in New York, Virginia, and Pennsylvania, USA; and the recent series of two coordinated attacks in Brussels (Belgium), on March 22, 2016, involving two bombings at the departure hall of Brussels International Airport and a bombing at Maalbeek Metro Station located near the European Commission headquarters in the center of Brussels. This statement paper deals with different aspects of hospital policy and disaster response planning that interface with terrorism. Research shows that the availability of necessary equipment and facilities (eg, personal protective clothing, decontamination rooms, antidotes, and anti-viral drugs) in hospitals clearly is insufficient. Emergency teams are insufficiently prepared: adequate and repetitive training remain necessary. Unfortunately, there are many examples of health care workers and physicians or hospitals being targeted in both political or religious conflicts and wars. Many health workers were kidnapped and/or killed by insurgents of various ideology. Attacks on hospitals also could cause long-term effects: hospital units could be unavailable for a long time and replacing staff could take several months, further compounding hospital operations. Both physical and psychological (eg, posttraumatic stress disorder [PTSD]) after-effects of a terrorist attack can be detrimental to health care services. On the other hand, physicians and other hospital employees have shown to be involved in terrorism. As data show that some offenders had a previous history with the location of the terror incident, the possibility of hospitals or other health care services being targeted by insiders is discussed. The purpose of this report was to consider how past terrorist incidents can inform current hospital preparedness and disaster response planning

  3. Targeted Therapy in Systemic Sclerosis

    Directory of Open Access Journals (Sweden)

    Murray Baron

    2016-10-01

    Full Text Available Targeted therapies use an understanding of the pathophysiology of a disease in an individual patient. Although targeted therapy for systemic sclerosis (SSc, scleroderma has not yet reached the level of patient-specific treatments, recent developments in the understanding of the global pathophysiology of the disease have led to new treatments based on the cells and pathways that have been shown to be involved in the disease pathogenesis. The presence of a B cell signature in skin biopsies has led to the trial of rituximab, an anti-CD20 antibody, in SSc. The well-known properties of transforming growth factor (TGF-β in promoting collagen synthesis and secretion has led to a small trial of fresolimumab, a human IgG4 monoclonal antibody capable of neutralizing TGF-β. Evidence supporting important roles for interleukin-6 in the pathogenesis of SSc have led to a large trial of tocilizumab in SSc. Soluble guanylate cyclase (sGC is an enzyme that catalyzes the production of cyclic guanosine monophosphate (cGMP upon binding of nitric oxide (NO to the sGC molecule. Processes such as cell growth and proliferation are regulated by cGMP. Evidence that sGC may play a role in SSc has led to a trial of riociguat, a molecule that sensitizes sGC to endogenous NO. Tyrosine kinases (TKs are involved in a wide variety of physiologic and pathological processes including vascular remodeling and fibrogenesis such as occurs in SSc. This has led to a trial of nintedanib, a next-generation tyrosine-kinase (TK inhibitor which targets multiple TKs, in SSc.

  4. Characterization of the energy distribution of neutrons generated by 5 MeV protons on a thick beryllium target at different emission angles

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, S. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Colautti, P., E-mail: paolo.colautti@lnl.infn.it [INFN, Laboratori Nazionali di Legnaro (LNL), Via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Esposito, J., E-mail: juan.esposito@tin.it [INFN, Laboratori Nazionali di Legnaro (LNL), Via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Fazzi, A.; Introini, M.V.; Pola, A. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2011-12-15

    Neutron energy spectra at different emission angles, between 0 Degree-Sign and 120 Degree-Sign from the Be(p,xn) reaction generated by a beryllium thick-target bombarded with 5 MeV protons, have been measured at the Legnaro Laboratories (LNL) of the Italian National Institute for Nuclear Physics research (INFN). A new and quite compact recoil-proton spectrometer, based on a monolithic silicon telescope, coupled to a polyethylene converter, was efficiently used with respect to the traditional Time-of-Flight (TOF) technique. The measured distributions of recoil-protons were processed through an iterative unfolding algorithm in order to determine the neutron energy spectra at all the angles accounted for. The neutron energy spectrum measured at 0 Degree-Sign resulted to be in good agreement with the only one so far available at the requested energy and measured years ago with TOF technique. Moreover, the results obtained at different emission angles resulted to be consistent with detailed past measurements performed at 4 MeV protons at the same angles by TOF techniques.

  5. Measurement of cross sections for alpha-induced reactions on 197Auand thick-target yields for the (alpha,gamma) process on 64Zn and63Cu

    Energy Technology Data Exchange (ETDEWEB)

    Basunia, M.S.; Shugart, H.A.; Smith, A.R.; Norman, E.B.

    2006-08-07

    We have measured the cross sections for the197Au(alpha,gamma)201Tl and 197Au(alpha,2n)199Tl reactions in the 17.9-to 23.9-MeV energy range, and 197Au(alpha,n)200Tl reaction in the 13.4-to 23.9-MeV energy range using an activation technique. Thick-targetyields for the 64Zn(alpha,gamma)68Ge (7- to 14-MeV) and63Cu(alpha,gamma)67Ga (7-MeV) reactions were measured. For allmeasurements, natural elements were bombarded with He+ beams from the88-inch Cyclotron at the Lawrence Berkeley National Laboratory (LBNL).Irradiated samples were counted using a gamma-spectrometry system at LBNLs Low Background Facility. Measured 197Au(alpha,gamma)201Tlcross-sections were compared with the NON-SMOKER theoretical values. Thethick-target yields for the 64Zn(alpha,gamma)68Ge and63Cu(alpha,gamma)67Ga reactions are also compared with the theoreticalyield, calculated numerically using the energy dependent NON-SMOKER crosssection data. In both cases, measured values are found to follow a trendof overlapping the predicted value near the alpha nucleus barrier heightand fall below with a slowly widening difference between them in the subbarrier energy points.

  6. Downstream targets of WRKY33

    DEFF Research Database (Denmark)

    Petersen, Klaus; Fiil, Berthe Katrine; Mundy, John

    2008-01-01

    Innate immunity signaling pathways in both animals and plants are regulated by mitogen-activated protein kinase (MAPK) cascades. In a recent publication we show that MPK4 and its substrate MKS1 interact with WRKY33 in vivo, and that WRKY33 is released from complexes with MPK4 upon infection. Tran...... immunoprecipitation confirmed that WRKY33 bound the promoter of PAD3 when plants were inoculated with pathogens. Here we further discuss the involvement of two other targets of WRKY33, NUDT6 and ROF2 in defense responses against invading pathogens....

  7. Performance Targets and External Benchmarking

    DEFF Research Database (Denmark)

    Friis, Ivar; Hansen, Allan; Vámosi, Tamás S.

    Research on relative performance measures, transfer pricing, beyond budgeting initiatives, target costing, piece rates systems and value based management has for decades underlined the importance of external benchmarking in performance management. Research conceptualises external benchmarking...... of the ‘inside’ costs of the sub-component, technical specifications of the product, opportunistic behavior from the suppliers and cognitive limitation. These are all aspects that easily can dismantle the market mechanism and make it counter-productive in the organization. Thus, by directing more attention...

  8. The challenge of targeting metastasis.

    Science.gov (United States)

    Fidler, Isaiah J; Kripke, Margaret L

    2015-12-01

    Metastases that are resistant to conventional therapy are the major cause of death from cancer. In most patients, metastasis has already occurred by the time of diagnosis. Thus, the prevention of metastasis is unlikely to be of therapeutic benefit. The biological heterogeneity of metastases presents a major obstacle to treatment. However, the growth and survival of metastases depend on interactions between tumor cells and host homeostatic mechanisms. Targeting these interactions, in addition to the tumor cells, can produce synergistic therapeutic effects against existing metastases.

  9. Introduction to radar target recognition

    CERN Document Server

    Tait, P

    2006-01-01

    This new text provides an overview of the radar target recognition process and covers the key techniques being developed for operational systems. It is based on the fundamental scientific principles of high resolution radar, and explains how the techniques can be used in real systems, taking into account the characteristics of practical radar system designs and component limitations. It also addresses operational aspects, such as how high resolution modes would fit in with other functions such as detection and tracking. Mathematics is kept to a minimum and the complex techniques and issues are

  10. Targeting α-synuclein oligomers

    DEFF Research Database (Denmark)

    van Diggelen, Femke

    2017-01-01

    Parkinson’s Disease (PD) is a complex disease, characterised by degeneration of neocortical, limbic and nigrostriatal neurons. It is unknown what initiates neurodegeneration, but soluble oligomers of the protein α-synuclein (αSn) seem to be particularly toxic, compared to insoluble fibrils....... Although there is currently no cure for PD, αSn oligomers (αSOs) are a potential therapeutic target, but a major drawback it that little is known about the nature of PD-associated αSOs. The scientific literature describes a wide variety of protocols to generate αSOs in vitro, with a subsequent...

  11. Ocena sprawności funkcjonalnej chorych na reumatoidalne zapalenie stawów na podstawie funkcjonalnego testu z wystandaryzowanym wyposażeniem

    OpenAIRE

    Grażyna Bączyk; Lucyna Gacek

    2011-01-01

    Reumatoidalne zapalenie stawów (RZS) jest przewlekle postępującymprocesem zapalnym błony maziowej, doprowadzającym doniszczenia tkanek stawowych i okołostawowych, w wyniku czegodochodzi do zniekształceń i upośledzenia funkcji stawów, co w konsekwencjiprowadzi do trwałego kalectwa. Celem badań była ocenasprawności funkcjonalnej chorych na RZS. Materiały i metody: Grupę badaną stanowiło 120 chorych na reumatoidalnezapalenie stawów leczonych w poradni reumatologicznejw Poznaniu. Kobiety stanowił...

  12. Ocena sprawności funkcjonalnej chorych na reumatoidalne zapalenie stawów na podstawie funkcjonalnego testu z wystandaryzowanym wyposażeniem

    Directory of Open Access Journals (Sweden)

    Grażyna Bączyk

    2011-02-01

    Full Text Available Reumatoidalne zapalenie stawów (RZS jest przewlekle postępującymprocesem zapalnym błony maziowej, doprowadzającym doniszczenia tkanek stawowych i okołostawowych, w wyniku czegodochodzi do zniekształceń i upośledzenia funkcji stawów, co w konsekwencjiprowadzi do trwałego kalectwa. Celem badań była ocenasprawności funkcjonalnej chorych na RZS. Materiały i metody: Grupę badaną stanowiło 120 chorych na reumatoidalnezapalenie stawów leczonych w poradni reumatologicznejw Poznaniu. Kobiety stanowiły 75% badanych. Średnia wiekubadanych to 52,15 roku (SD 12,73. Średni czas trwania chorobywynosił 13,47 roku, (SD 8,62 (tab. I.Objawy ze strony układu kostno-stawowego oceniano wg następującychzasad: czas trwania sztywności porannej, natężenie bólu wgskali VAS, bolesność uciskowa stawów z wykorzystaniem RitchieArticular Index, siła mięśniowa ręki na podstawie siły chwytu. Dooceny sprawności funkcjonalnej chorych wykorzystano funkcjonalnytest z wystandaryzowanym wyposażeniem (tab. II. Wyniki: Około 60% kobiet i 40% mężczyzn nie było zdolnych dowykonania takiego zadania, jak otwieranie słoika. Wykonanie większościzadań wymagało od badanych zastosowania pewnego rodzajupomocy technicznej albo wykonanie danej czynności odbywało siępowoli czy też z pomocą drugiej osoby (tab. III. Wnioski: Złe wyniki oceny funkcjonowania chorych na reumatoidalnezapalenie stawów, niezależnie od płci, świadczą o ograniczeniumożliwości wykonywania podstawowych aktywności życiowych.Wiązało się to z bólem stawów, czasem trwania objawu sztywnościporannej oraz słabą siłą mięśniową rąk.

  13. Dissolution of Ceramic Monolith of Spent Catalytic Converters by Using Hydrometallurgical Methods / Rozpuszczanie Monolitu Ceramicznego Zużytych Katalizatorów Na Drodze Hydrometalurgicznej

    Directory of Open Access Journals (Sweden)

    Willner J.

    2015-12-01

    Full Text Available Catalytic converters contain the catalytic substance in their structure, which is a mixture of Platinum Group Metals (PGMs: platinum, palladium and rhodium. The prices of these metals and a growing demand for them in the market, make it necessary to recycle spent catalytic converters and recovery of PGMs. The ceramic monolith of catalytic converters is still a predominant material in its construction among of multitude of catalytic converters which are in circulation. In this work attempts were made to leach additional metals (excluding Pt from comminuted ceramic monolith. Classic leachant oxidizing media 10M H2SO4, HCl and H3PO4 were used considering the possibility of dissolution of the ceramic monolith.

  14. KILKA UWAG O PRZEKŁADZIE TYTUŁÓW NA PODSTAWIE TUŁMACZEŃ NIEMIECKO-POLSKICH I POLSKO-NIEMIECKICH

    OpenAIRE

    Biaduń-Grabarek, Hanna; Grabarek, Józef

    2012-01-01

    The article discusses problems related to translating titles of films, literary works and academic publications from German to Polish and vice-versa. The authors emphasize aspects common to translation of all titles, and analyse typical problems occurring while rendering film and literary titles. In case of titles of academic publications formal and content-related changes are considerably smaller than, for instance, in film titles. This is due to the fact that while working on the latter tra...

  15. Raportowanie banków na temat zrównoważonego rozwoju według standardów Global Reporting Initiative

    Directory of Open Access Journals (Sweden)

    Ana Novokmet

    2016-09-01

    Full Text Available Rachunkowość zrównoważonego rozwoju, z jej ostatecznym produktem – raportami społecznej odpo-wiedzialności, jest nową dziedziną rachunkowości i koncentruje się na ocenie i monitorowaniu działań w zakresie zarządzania firmą, ochrony środowiska i integracji społecznej oraz interakcji z otoczeniem. Wśród kilku standardowych ram, firmy na całym świecie często wybierają wytyczne Sustainability Re-porting Global Reporting Initiative (GRI. Od roku 2000 wytyczne GRI ewoluowały i obecnie jest do-stępna czwarta ich generacja. Celem tego artykułu jest ocena raportowania społecznego w ramach zinte-growanych raportów w sektorze bankowym na przykładzie UniCredit Group, która działa w 15 krajach. Raportowanie zrównoważonego rozwoju stanie się obowiązkowe w Unii Europejskiej dla dużych firm, notowanych na giełdach spółek i jednostek interesu publicznego (na przykład banków ze średnim za-trudnieniem co najmniej 500 pracowników, począwszy od roku 2018 (dla działalności w 2017 r.. Wniniejszym artykule skoncentrowano się na krytycznej analizie treści raportu społecznego banku.

  16. LIFE Target Fabrication Research Plan Sept 2008

    Energy Technology Data Exchange (ETDEWEB)

    Miles, R; Biener, J; Kucheyev, S; Montesanti, R; Satcher, J; Spadaccini, C; Rose, K; Wang, M; Hamza, A; Alexander, N; Brown, L; Hund, J; Petzoldt, R; Sweet, W; Goodin, D

    2008-11-10

    The target-system for the baseline LIFE fast-ignition target was analyzed to establish a preliminary estimate for the costs and complexities involved in demonstrating the technologies needed to build a prototype LIFE plant. The baseline fast-ignition target upon which this analysis was developed is shown in Figure 1.0-1 below. The LIFE target-system incorporates requirements for low-cost, high throughput manufacture, high-speed, high accuracy injection of the target into the chamber, production of sufficient energy from implosion and recovery and recycle of the imploded target material residue. None of these functions has been demonstrated to date. Existing target fabrication techniques which lead to current 'hot spot' target costs of {approx}$100,000 per target and at a production rate of 2/day are unacceptable for the LIFE program. Fabrication techniques normally used for low-cost, low accuracy consumer products such as toys must be adapted to the high-accuracy LIFE target. This will be challenge. A research program resulting is the demonstration of the target-cycle technologies needed for a prototype LIFE reactor is expected to cost {approx}$51M over the course of 5 years. The effort will result in targets which will cost an estimated $0.23/target at a rep-rate of 20 Hz or about 1.73M targets/day.

  17. Targeting telomerase with radiolabeled inhibitors.

    Science.gov (United States)

    Waghorn, Philip A; Jackson, Mark R; Gouverneur, Veronique; Vallis, Katherine A

    2017-01-05

    The expression of telomerase in approximately 85% of cancers and its absence in the majority of normal cells makes it an attractive target for cancer therapy. However the lag period between initiation of telomerase inhibition and growth arrest makes direct inhibition alone an insufficient method of treatment. However, telomerase inhibition has been shown to enhance cancer cell radiosensitivity. To investigate the strategy of simultaneously inhibiting telomerase while delivering targeted radionuclide therapy to cancer cells, 123 I-radiolabeled inhibitors of telomerase were synthesized and their effects on cancer cell survival studied. An 123 I-labeled analogue of the telomerase inhibitor MST-312 inhibited telomerase with an IC 50 of 1.58 μM (MST-312 IC 50 : 0.23 μM). Clonogenic assays showed a dose dependant effect of 123 I-MST-312 on cell survival in a telomerase positive cell line, MDA-MB-435. Copyright © 2016 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

  18. Properties of Protein Drug Target Classes

    Science.gov (United States)

    Bull, Simon C.; Doig, Andrew J.

    2015-01-01

    Accurate identification of drug targets is a crucial part of any drug development program. We mined the human proteome to discover properties of proteins that may be important in determining their suitability for pharmaceutical modulation. Data was gathered concerning each protein’s sequence, post-translational modifications, secondary structure, germline variants, expression profile and drug target status. The data was then analysed to determine features for which the target and non-target proteins had significantly different values. This analysis was repeated for subsets of the proteome consisting of all G-protein coupled receptors, ion channels, kinases and proteases, as well as proteins that are implicated in cancer. Machine learning was used to quantify the proteins in each dataset in terms of their potential to serve as a drug target. This was accomplished by first inducing a random forest that could distinguish between its targets and non-targets, and then using the random forest to quantify the drug target likeness of the non-targets. The properties that can best differentiate targets from non-targets were primarily those that are directly related to a protein’s sequence (e.g. secondary structure). Germline variants, expression levels and interactions between proteins had minimal discriminative power. Overall, the best indicators of drug target likeness were found to be the proteins’ hydrophobicities, in vivo half-lives, propensity for being membrane bound and the fraction of non-polar amino acids in their sequences. In terms of predicting potential targets, datasets of proteases, ion channels and cancer proteins were able to induce random forests that were highly capable of distinguishing between targets and non-targets. The non-target proteins predicted to be targets by these random forests comprise the set of the most suitable potential future drug targets, and should therefore be prioritised when building a drug development programme. PMID

  19. Bioengineering Strategies for Designing Targeted Cancer Therapies

    Science.gov (United States)

    Wen, Xuejun

    2014-01-01

    The goals of bioengineering strategies for targeted cancer therapies are (1) to deliver a high dose of an anticancer drug directly to a cancer tumor, (2) to enhance drug uptake by malignant cells, and (3) to minimize drug uptake by nonmalignant cells. Effective cancer-targeting therapies will require both passive- and active targeting strategies and a thorough understanding of physiologic barriers to targeted drug delivery. Designing a targeted therapy includes the selection and optimization of a nanoparticle delivery vehicle for passive accumulation in tumors, a targeting moiety for active receptor-mediated uptake, and stimuli-responsive polymers for control of drug release. The future direction of cancer targeting is a combinatorial approach, in which targeting therapies are designed to use multiple targeting strategies. The combinatorial approach will enable combination therapy for delivery of multiple drugs and dual ligand targeting to improve targeting specificity. Targeted cancer treatments in development and the new combinatorial approaches show promise for improving targeted anticancer drug delivery and improving treatment outcomes. PMID:23768509

  20. TARGET 2 and Settlement Finality

    Directory of Open Access Journals (Sweden)

    Ivan MANGATCHEV

    2011-03-01

    Full Text Available This article examines how TARGET 2 as system implements the idea of settlement finality regulated by Directive 98/26 EC of the European parliament and of the Council of 19 May 1998 on settlement finality in payment and securities settlement systems (Settlement Finality Directive and Directive 2009/44/EC of the European parliament and of the Council of 6 May 2009 amending Directive 98/26/EC on settlement finality in payment and securities settlement systems and Directive 2002/47/EC on financial collateral arrangements as regards linked systems and credit claims (Directive 2009/44/EC. As the title of the arti and finality of the settlement in this system.

  1. Terahertz-based target typing.

    Energy Technology Data Exchange (ETDEWEB)

    Lyo, Sungkwun Kenneth; Wanke, Michael Clement; Reno, John Louis; Shaner, Eric Arthur; Grine, Albert D.; Barrick, Todd A.

    2008-09-01

    The purpose of this work was to create a THz component set and understanding to aid in the rapid analysis of transient events. This includes the development of fast, tunable, THz detectors, along with filter components for use with standard detectors and accompanying models to simulate detonation signatures. The signature effort was crucial in order to know the spectral range to target for detection. Our approach for frequency agile detection was to utilize plasmons in the channel of a specially designed field-effect transistor called the grating-gate detector. Grating-gate detectors exhibit narrow-linewidth, broad spectral tunability through application of a gate bias, and no angular dependence in their photoresponse. As such, if suitable sensitivity can be attained, they are viable candidates for Terahertz multi-spectral focal plane arrays.

  2. Gene Therapy Targeting HIV Entry

    Directory of Open Access Journals (Sweden)

    Chuka Didigu

    2014-03-01

    Full Text Available Despite the unquestionable success of antiretroviral therapy (ART in the treatment of HIV infection, the cost, need for daily adherence, and HIV-associated morbidities that persist despite ART all underscore the need to develop a cure for HIV. The cure achieved following an allogeneic hematopoietic stem cell transplant (HSCT using HIV-resistant cells, and more recently, the report of short-term but sustained, ART-free control of HIV replication following allogeneic HSCT, using HIV susceptible cells, have served to both reignite interest in HIV cure research, and suggest potential mechanisms for a cure. In this review, we highlight some of the obstacles facing HIV cure research today, and explore the roles of gene therapy targeting HIV entry, and allogeneic stem cell transplantation in the development of strategies to cure HIV infection.

  3. Targeting Persistent Human Papillomavirus Infection.

    Science.gov (United States)

    Shanmugasundaram, Srinidhi; You, Jianxin

    2017-08-18

    While the majority of Human papillomavirus (HPV) infections are transient and cleared within a couple of years following exposure, 10-20% of infections persist latently, leading to disease progression and, ultimately, various forms of invasive cancer. Despite the clinical efficiency of recently developed multivalent prophylactic HPV vaccines, these preventive measures are not effective against pre-existing infection. Additionally, considering that the burden associated with HPV is greatest in regions with limited access to preventative vaccination, the development of effective therapies targeting persistent infection remains imperative. This review discusses not only the mechanisms underlying persistent HPV infection, but also the promise of immunomodulatory therapeutic vaccines and small-molecular inhibitors, which aim to augment the host immune response against the viral infection as well as obstruct critical viral-host interactions.

  4. Targeting ECM Disrupts Cancer Progression

    DEFF Research Database (Denmark)

    Venning, Freja A; Wullkopf, Lena; Erler, Janine T

    2015-01-01

    Metastatic complications are responsible for more than 90% of cancer-related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multistep process, with each step involving intricate cross talk between the cancer cells and their non-cellular surroundings, the ex...... is summarized. In addition, we highlight the promising (pre-)clinical data showing benefits of targeting these ECM macromolecules to prevent cancer progression.......Metastatic complications are responsible for more than 90% of cancer-related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multistep process, with each step involving intricate cross talk between the cancer cells and their non-cellular surroundings......, the extracellular matrix (ECM). Many ECM proteins are significantly deregulated during the progression of cancer, causing both biochemical and biomechanical changes that together promote the metastatic cascade. In this review, the influence of several ECM proteins on these multiple steps of cancer spread...

  5. Obesity treatment: novel peripheral targets.

    Science.gov (United States)

    Field, Benjamin C T; Chaudhri, Owais B; Bloom, Stephen R

    2009-12-01

    Our knowledge of the complex mechanisms underlying energy homeostasis has expanded enormously in recent years. Food intake and body weight are tightly regulated by the hypothalamus, brainstem and reward circuits, on the basis both of cognitive inputs and of diverse humoral and neuronal signals of nutritional status. Several gut hormones, including cholecystokinin, glucagon-like peptide-1, peptide YY, oxyntomodulin, amylin, pancreatic polypeptide and ghrelin, have been shown to play an important role in regulating short-term food intake. These hormones therefore represent potential targets in the development of novel anti-obesity drugs. This review focuses on the role of gut hormones in short- and long-term regulation of food intake, and on the current state of development of gut hormone-based obesity therapies.

  6. Moringa oleifera Lam: Targeting Chemoprevention.

    Science.gov (United States)

    Karim, Nurul Ashikin Abd; Ibrahim, Muhammad Din; Kntayya, Saie Brindha; Rukayadi, Yaya; Hamid, Hazrulizawati Abd; Razis, Ahmad Faizal Abdull

    2016-01-01

    Moringa oleifera Lam, family Moringaceae, is a perennial plant which is called various names, but is locally known in Malaysia as "murungai" or "kelor". Glucomoringin, a glucosinolate with from M. oleifera is a major secondary metabolite compound. The seeds and leaves of the plant are reported to have the highest amount of glucosinolates. M. oleifera is well known for its many uses health and benefits. It is claimed to have nutritional, medicinal and chemopreventive potentials. Chemopreventive effects of M. oleifera are expected due to the existence of glucosinolate which it is reported to have the ability to induce apoptosis in anticancer studies. Furthermore, chemopreventive value of M. oleifera has been demonstrated in studies utilizing its leaf extract to inhibit the growth of human cancer cell lines. This review highlights the advantages of M. oleifera targeting chemoprevention where glucosinolates could help to slow the process of carcinogenesis through several molecular targets. It is also includes inhibition of carcinogen activation and induction of carcinogen detoxification, anti-inflammatory, anti-tumor cell proliferation, induction of apoptosis and inhibition of tumor angiogenesis. Finally, for synergistic effects of M. oleifera with other drugs and safety, essential for chemoprevention, it is important that it safe to be consumed by human body and works well. Although there is promising evidence about M. oleifera in chemoprevention, extensive research needs to be done due to the expected rise of cancer in coming years and to gain more information about the mechanisms involved in M. oleifera influence, which could be a good source to inhibit several major mechanisms involved in cancer development.

  7. Target therapies in pancreatic carcinoma.

    Science.gov (United States)

    Silvestris, Nicola; Gnoni, Antonio; Brunetti, Anna Elisabetta; Vincenti, Leonardo; Santini, Daniele; Tonini, Giuseppe; Merchionne, Francesca; Maiello, Evaristo; Lorusso, Vito; Nardulli, Patrizia; Azzariti, Amalia; Reni, Michele

    2014-01-01

    Pancreatic ductal adenocarcinoma (PDAC) occurs in the majority of cases with early locoregional spread and distant metastases at diagnosis, leading to dismal prognosis and limited treatment options. Traditional cytotoxic chemotherapy provides only modest benefit to patients with PDAC. Identification of different molecular pathways, overexpressed in pancreatic cancer cells, has provided the opportunity to develop targeted therapies (monoclonal antibodies and small-molecule inhibitors) and peculiar new class of taxanes with a crucial therapeutic role in this cancer setting. A phase III trial has shown that erlotinib in combination with gemcitabine was clinically irrelevant and skin toxicity can be a positive prognostic factor. Moreover, the combination of cetuximab or erlotinib with radiotherapy in advanced pancreatic cancer has shown to be synergistic and a reversal of radio-resistance has been suggested by inhibition of VEGF/EGFR pathway. To overcome EGFR-inhibition therapy resistance several alternative pathways targets are under investigation (IGF- 1R, MMPs, Hedgehog proteins, m-TOR, MEK, COX-2) and provide the rationale for clinical use in phase II/III studies. Also nab-paclitaxel, a new taxanes class, uses high pancreatic albumin-binding protein SPARC levels to act in cancer cells with a less toxic and more effective dose with respect to classic taxanes. Understanding of molecular pathogenesis of pancreatic adenocarcinoma continues to expand. However, many promising data in preclinic and phase I/II trials did not yield promise in phase III trials, suggesting that identification of predictive biomarkers for these new agents is mandatory. The knowledge of biologic and molecular aspects of pancreatic cancer can be the basis for future therapeutic developments.

  8. Combinatorial microRNA target predictions

    DEFF Research Database (Denmark)

    Krek, Azra; Grün, Dominic; Poy, Matthew N.

    2005-01-01

    MicroRNAs are small noncoding RNAs that recognize and bind to partially complementary sites in the 3' untranslated regions of target genes in animals and, by unknown mechanisms, regulate protein production of the target transcript1, 2, 3. Different combinations of microRNAs are expressed...... in different cell types and may coordinately regulate cell-specific target genes. Here, we present PicTar, a computational method for identifying common targets of microRNAs. Statistical tests using genome-wide alignments of eight vertebrate genomes, PicTar's ability to specifically recover published micro......RNA targets, and experimental validation of seven predicted targets suggest that PicTar has an excellent success rate in predicting targets for single microRNAs and for combinations of microRNAs. We find that vertebrate microRNAs target, on average, roughly 200 transcripts each. Furthermore, our results...

  9. Targets and processes for fabricating same

    Science.gov (United States)

    Cowna, Thomas; Malekos, Steven; Korgan, Grant; Adams, Jesse; Sentoku, Yasuhiko; LeGalloudec, Nathalie

    2014-06-10

    In particular embodiments, the present disclosure provides targets including a metal layer and defining a hollow inner surface. The hollow inner surface has an internal apex. The distance between at least two opposing points of the internal apex is less than about 15 .mu.m. In particular examples, the distance is less than about 1 .mu.m. Particular implementations of the targets are free standing. The targets have a number of disclosed shaped, including cones, pyramids, hemispheres, and capped structures. The present disclosure also provides arrays of such targets. Also provided are methods of forming targets, such as the disclosed targets, using lithographic techniques, such as photolithographic techniques. In particular examples, a target mold is formed from a silicon wafer and then one or more sides of the mold are coated with a target material, such as one or more metals.

  10. Cooperative tumour cell membrane targeted phototherapy

    Science.gov (United States)

    Kim, Heegon; Lee, Junsung; Oh, Chanhee; Park, Ji-Ho

    2017-06-01

    The targeted delivery of therapeutics using antibodies or nanomaterials has improved the precision and safety of cancer therapy. However, the paucity and heterogeneity of identified molecular targets within tumours have resulted in poor and uneven distribution of targeted agents, thus compromising treatment outcomes. Here, we construct a cooperative targeting system in which synthetic and biological nanocomponents participate together in the tumour cell membrane-selective localization of synthetic receptor-lipid conjugates (SR-lipids) to amplify the subsequent targeting of therapeutics. The SR-lipids are first delivered selectively to tumour cell membranes in the perivascular region using fusogenic liposomes. By hitchhiking with extracellular vesicles secreted by the cells, the SR-lipids are transferred to neighbouring cells and further spread throughout the tumour tissues where the molecular targets are limited. We show that this tumour cell membrane-targeted delivery of SR-lipids leads to uniform distribution and enhanced phototherapeutic efficacy of the targeted photosensitizer.

  11. Study Identifies New Lymphoma Treatment Target

    Science.gov (United States)

    NCI researchers have identified new therapeutic targets for diffuse large B-cell lymphoma. Drugs that hit these targets are under clinical development and the researchers hope to begin testing them in clinical trials of patients with DLBCL.

  12. On the large COMPASS polarized deuteron target

    CERN Document Server

    Finger, M; Baum, G; Doshita, N; Finger, M Jr; Gautheron, F; Goertz, St; Hasegawa, T; Heckmann, J; Hess, Ch; Horikawa, N; Ishimoto, S; Iwata, T; Kisselev, Y; Koivuniemi, J; Kondo, K; Le Goff, J-M; Magnon, A; Marchand, C; Matsuda, T; Meyer, W; Reicherz, G; Srnka, A

    2006-01-01

    The spin structure of the nucleons is investigated in deep inelastic scattering of a polarized muon beam and a polarized nucleon target in the COMPASS experiment at CERN since 2001. To achieve high luminosities a large solid polarized target is used. The COMPASS polarized target consists of a high cooling power $^{3}$He/$^{4}$He dilution refrigerator capable to maintain working temperature of the target material at about 50mK, a superconducting solenoid and dipole magnet system for longitudinal and transversal magnetic field on the target material, respectively, target cells containing polarizable material, microwave cavities and high power microwave radiation systems for dynamic nuclear polarization and the nuclear magnetic resonance system for nuclear spin polarization measurements. During 2001–2004 experiments superconducting magnet system with opening angle $\\pm$69 mrad, polarized target holder with two target cells and corresponding microwave and NMR systems have been used. For the data taking from 200...

  13. Targeting Cancer with Antisense Oligomers

    Energy Technology Data Exchange (ETDEWEB)

    Hnatowich, DJ

    2008-10-28

    With financial assistance from the Department of Energy, we have shown definitively that radiolabeled antisense DNAs and other oligomers will accumulate in target cancer cells in vitro and in vivo by an antisense mechanism. We have also shown that the number of mRNA targets for our antisense oligomers in the cancer cell types that we have investigated so far is sufficient to provide and antisense image and/or radiotherapy of cancer in mice. These studies have been reported in about 10 publications. However our observation over the past several years has shown that radiolabeled antisense oligomers administered intravenously in their native and naked form will accumulate and be retained in target xenografts by an antisense mechanism but will also accumulate at high levels in normal organs such as liver, spleen and kidneys. We have investigated unsuccessfully several commercially available vectors. Thus the use of radiolabeled antisense oligomers for the imaging of cancer must await novel approaches to delivery. This laboratory has therefore pursued two new paths, optical imaging of tumor and Auger radiotherapy. We are developing a novel method of optical imaging tumor using antisense oligomers with a fluorophore is administered while hybridized with a shorter complementary oligomer with an inhibitor. In culture and in tumored mice that the duplex remains intact and thus nonfluorescent until it encounters its target mRNA at which time it dissociates and the antisense oligomer binds along with its fluorophore to the target. Simultaneous with the above, we have also observed, as have others, that antisense oligomers migrate rapidly and quantitatively to the nucleus upon crossing cell membranes. The Auger electron radiotherapy path results from this observation since the nuclear migration properties could be used effectively to bring and to retain in the nucleus an Auger emitting radionuclide such as 111In or 125I bound to the antisense oligomer. Since the object becomes

  14. Targeted integration of genes in Xenopus tropicalis

    DEFF Research Database (Denmark)

    Shi, Zhaoying; Tian, Dandan; Xin, Huhu

    2017-01-01

    With the successful establishment of both targeted gene disruption and integration methods in the true diploid frog Xenopus tropicalis, this excellent vertebrate genetic model now is making a unique contribution to modelling human diseases. Here, we summarize our efforts on establishing homologous...... recombination-mediated targeted integration in Xenopus tropicalis, the usefulness, and limitation of targeted integration via the homology-independent strategy, and future directions on how to further improve targeted gene integration in Xenopus tropicalis....

  15. Capacitive Sensors And Targets Would Measure Alignments

    Science.gov (United States)

    Jenstrom, Del T.

    1994-01-01

    Multiple capacitive sensors and active targets used to measure distance between, and relative orientation of, two objects. Sensed target signals processed and used by control systems to align objects to be joined. Shapes, sizes, and layouts of sensors and targets optimized for specific application. Particular layout of targets and sensors enables determination of relative position and orientation of two objects in all six degrees of freedom.

  16. 40 CFR 35.9020 - Planning targets.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Planning targets. 35.9020 Section 35... STATE AND LOCAL ASSISTANCE Financial Assistance for the National Estuary Program § 35.9020 Planning targets. The EPA Assistant Administrator for Water develops planning targets each year to help each...

  17. Inflation Targeting and Business Cycle Synchronization

    OpenAIRE

    Flood, Robert P; Rose, Andrew K

    2009-01-01

    Inflation targeting seems to have a small but positive effect on the synchronization of business cycles; countries that target inflation seem to have cycles that move slightly more closely with foreign cycles. Thus the advent of inflation targeting does not explain the decoupling of global business cycles, for two reasons. Indeed business cycles have not in fact become less synchronized across countries.

  18. Starkweather Target Game for Preschool Children.

    Science.gov (United States)

    Starkweather, Elizabeth K.

    The Starkweather Target Game is designed to measure preschool children's willingness to try difficult tasks independent of ability. The game consists of a box-shaped target which responds, when the target is hit by a rolled ball, somewhat like a jack-in-a-box. When the bull's eye is hit, the lid opens and a surprise picture appears. After being…

  19. Vergence facility with stereoscopic and nonstereoscopic targets.

    Science.gov (United States)

    Momeni-Moghaddam, Hamed; Goss, David A; Dehvari, Abubakr

    2014-05-01

    To compare vergence facility with nonstereo and stereo targets in binocular symptomatic and asymptomatic subjects. Sixty-six students were divided into symptomatic and asymptomatic groups according to the Convergence Insufficiency Symptom Survey Questionnaire score. Vergence facility was tested at 40 cm by flipper prism 3Δ BI/12Δ BO (BI, base-in; BO, base-out). The targets used were a nonstereo target (a vertical column of small letter "E" of ~20/30 size), a stereo-local target (fifth set of circles of the Titmus test with stereoacuity of 100 arcsec), and a stereo-global target (page 6 of the TNO test with stereoacuity of 120 arcsec). Repeated-measures analysis of variance showed differences in the mean vergence facility with different targets in all subjects and separately in two symptom groups (p 0.05) but significant for the comparison of stereo-global targets with the other two targets. The receiver operating characteristic curve analysis showed the cutoff points 10.5, 10.5, and 9.75 cycles per minute with nonstereo, stereo-local, and stereo-global targets, respectively. The sensitivity of the three targets used was the same (97%). Specificity was 0.93 or higher with all three targets, with the highest specificity obtained with the stereo-global target (100%). The highest vergence facility was obtained with a nonstereo target and the lowest was obtained with a stereo-global target. High sensitivity with all three targets means that there are few false-negative results with them, and the high specificity is indicative of low false-positive results. Hence, the vergence facility predictive value would be high in diagnosing binocular symptomatic patients using a 3Δ BI/12Δ BO prism flipper at near and a response cutoff of about 10 cycles per minute or less.

  20. Targeted alpha therapy for cancer

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Barry J [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Raja, Chand [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Rizvi, Syed [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Li Yong [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Tsui, Wendy [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Zhang, David [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Song, Emma [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Qu, C F [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Kearsley, John [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Graham, Peter [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Thompson, John [Sydney Melanoma Unit, Royal Prince Alfred Hospital, Camperdown 2050 NSW (Australia)

    2004-08-21

    Targeted alpha therapy (TAT) offers the potential to inhibit the growth of micrometastases by selectively killing isolated and preangiogenic clusters of cancer cells. The practicality and efficacy of TAT is tested by in vitro and in vivo studies in melanoma, leukaemia, colorectal, breast and prostate cancers, and by a phase 1 trial of intralesional TAT for melanoma. The alpha-emitting radioisotope used is Bi-213, which is eluted from the Ac-225 generator and chelated to a cancer specific monoclonal antibody (mab) or protein (e.g. plasminogen activator inhibitor-2 PAI2) to form the alpha-conjugate (AC). Stable alpha-ACs have been produced which have been tested for specificity and cytotoxicity in vitro against melanoma (9.2.27 mab), leukaemia (WM60), colorectal (C30.6), breast (PAI2, herceptin), ovarian (PAI2, herceptin, C595), prostate (PAI2, J591) and pancreatic (PAI2, C595) cancers. Subcutaneous inoculation of 1-1.5 million human cancer cells into the flanks of nude mice causes tumours to grow in all mice. Tumour growth is compared for untreated controls, nonspecific AC and specific AC, for local (subcutaneous) and systemic (tail vein or intraperitoneal) injection models. The {sup 213}Bi-9.2.27 AC is injected into secondary skin melanomas in stage 4 patients in a dose escalation study to determine the effective tolerance dose, and to measure kinematics to obtain the equivalent dose to organs. In vitro studies show that TAT is one to two orders of magnitude more cytotoxic to targeted cells than non-specific ACs, specific beta emitting conjugates or free isotopes. In vivo local TAT at 2 days post-inoculation completely prevents tumour formation for all cancers tested so far. Intra-lesional TAT can completely regress advanced sc melanoma but is less successful for breast and prostate cancers. Systemic TAT inhibits the growth of sc melanoma xenografts and gives almost complete control of breast and prostate cancer tumour growth. Intralesional doses up to 450 {mu

  1. Tantalum/Copper X-Ray Targets

    Science.gov (United States)

    Waters, William J.; Edmonds, Brian

    1993-01-01

    Lewis Research Center developed unique solution to subsidiary problem of fabrication of x-ray target. Plasma spraying enabled fabrication of lightweight, high-performance targets. Power settings, atmosphere-control settings, rate of deposition, and other spraying parameters developed. Thin coats of tantalum successfully deposited on copper targets. Targets performed successfully in tests and satisfied all criteria expressed in terms of critical parameters. Significantly reduces projected costs of fabrication of targets and contributes to development of improved, long-lived, lightweight x-ray system.

  2. Targeting nominal income growth or inflation?

    DEFF Research Database (Denmark)

    Jensen, Henrik

    2002-01-01

    Within a simple New Keynesian model emphasizing forward-looking behavior of private agents, I evaluate optimal nominal income growth targeting versus optimal inflation targeting. When the economy is mainly subject to shocks that do not involve monetary policy trade-offs for society, inflation...... targeting is preferable. Otherwise, nominal income growth targeting may be superior because it induces inertial policy making, which improves the inflation-output-gap trade-off. Somewhat paradoxically, inflation targeting may be relatively less favorable the more society dislikes inflation, and the more...

  3. Improved Targeting of Cancers with Nanotherapeutics

    DEFF Research Database (Denmark)

    Foster, Christian; Watson, Andre; Kaplinsky, Joseph John

    2017-01-01

    Targeted cancer nanotherapeutics offers numerous opportunities for the selective uptake of toxic chemotherapies within tumors and cancer cells. The unique properties of nanoparticles, such as their small size, large surface-to-volume ratios, and the ability to achieve multivalency of targeting...... ligands on their surface, provide superior advantages for nanoparticle-based drug delivery to a variety of cancers. This review highlights various key concepts in the design of targeted nanotherapeutics for cancer therapy, and discusses physicochemical parameters affecting nanoparticle targeting, along...... with recent developments for cancer-targeted nanomedicines....

  4. Graphite target for the spiral project

    Energy Technology Data Exchange (ETDEWEB)

    Putaux, J.C.; Ducourtieux, M.; Ferro, A.; Foury, P.; Kotfila, L.; Mueller, A.C.; Obert, J.; Pauwels, N.; Potier, J.C.; Proust, J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Bertrand, P. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Loiselet, M. [Universite Catholique de Louvain, Louvain-La-Neuve (Belgium)] [and others

    1996-12-31

    A study of the thermal and physical properties of graphite targets for the SPIRAL project is presented. The main objective is to develop an optimized set-up both mechanically and thermally resistant, presenting good release properties (hot targets with thin slices). The results of irradiation tests concerning the mechanical and thermal resistance of the first prototype of SPIRAL target with conical geometry are presented. The micro-structural properties of the graphite target is also studied, in order to check that the release properties are not deteriorated by the irradiation. Finally, the results concerning the latest pilot target internally heated by an electrical current are shown. (author). 5 refs.

  5. The trajectory of the target probability effect.

    Science.gov (United States)

    Hon, Nicholas; Yap, Melvin J; Jabar, Syaheed B

    2013-05-01

    The effect of target probability on detection times is well-established: Even when detection accuracy is high, lower probability targets are detected more slowly than higher probability ones. Although this target probability effect on detection times has been well-studied, one aspect of it has remained largely unexamined: How the effect develops over the span of an experiment. Here, we investigated this issue with two detection experiments that assessed different target probability ratios. Conventional block segment analysis and linear mixed-effects modeling converged on two key findings. First, we found that the magnitude of the target probability effect increases as one progresses through a block of trials. Second, we found, by examining the trajectories of the low- and high-probability targets, that this increase in effect magnitude was driven by the low-probability targets. Specifically, we found that low-probability targets were detected more slowly as a block of trials progressed. Performance to high-probability targets, on the other hand, was largely invariant across the block. The latter finding is of particular interest because it cannot be reconciled with accounts that propose that the target probability effect is driven by the high-probability targets.

  6. Secondary anchor targeted cell release.

    Science.gov (United States)

    Ansari, Ali; Lee-Montiel, Felipe T; Amos, Jennifer R; Imoukhuede, P I

    2015-11-01

    Personalized medicine offers the promise of tailoring therapy to patients, based on their cellular biomarkers. To achieve this goal, cellular profiling systems are needed that can quickly and efficiently isolate specific cell types without disrupting cellular biomarkers. Here we describe the development of a unique platform that facilitates gentle cell capture via a secondary, surface-anchoring moiety, and cell release. The cellular capture system consists of a glass surface functionalized with APTES, d-desthiobiotin, and streptavidin. Biotinylated mCD11b and hIgG antibodies are used to capture mouse macrophages (RAW 264.7) and human breast cancer (MCF7-GFP) cell lines, respectively. The surface functionalization is optimized by altering assay components, such as streptavidin, d-desthiobiotin, and APTES, to achieve cell capture on 80% of the functionalized surface and cell release upon biotin treatment. We also demonstrate an ability to capture 50% of target cells within a dual-cell mixture. This engineering advancement is a critical step towards achieving cell isolation platforms for personalized medicine. © 2015 Wiley Periodicals, Inc.

  7. Targeting ceramide metabolism in obesity.

    Science.gov (United States)

    Aburasayn, Hanin; Al Batran, Rami; Ussher, John R

    2016-08-01

    Obesity is a major health concern that increases the risk for insulin resistance, type 2 diabetes (T2D), and cardiovascular disease. Thus, an enormous research effort has been invested into understanding how obesity-associated dyslipidemia and obesity-induced alterations in lipid metabolism increase the risk for these diseases. Accordingly, it has been proposed that the accumulation of lipid metabolites in organs such as the liver, skeletal muscle, and heart is critical to these obesity-induced pathologies. Ceramide is one such lipid metabolite that accumulates in tissues in response to obesity, and both pharmacological and genetic strategies that reduce tissue ceramide levels yield salutary actions on overall metabolic health. We will review herein why ceramide accumulates in tissues during obesity and how an increase in intracellular ceramide impacts cellular signaling and function as well as potential mechanisms by which reducing intracellular ceramide levels improves insulin resistance, T2D, atherosclerosis, and heart failure. Because a reduction in skeletal muscle ceramide levels is frequently associated with improvements in insulin sensitivity in humans, the beneficial findings reported for reducing ceramides in preclinical studies may have clinical application in humans. Therefore, modulating ceramide metabolism may be a novel, exciting target for preventing and/or treating obesity-related diseases. Copyright © 2016 the American Physiological Society.

  8. Resource implications of a national health target

    DEFF Research Database (Denmark)

    Jones, Peter; Sopina, Liza Elizaveta; Ashton, Toni

    2014-01-01

    Background The Shorter Stays in Emergency Departments health target was introduced in New Zealand in 2009. District Health Boards (DHBs) are expected to meet the target with no additional funding or incentives. The costs of implementing such targets have not previously been studied. Method A survey...... of clinical/service managers in ED throughout New Zealand determined the type and cost of resources used for the target. Responses to the target were classified according to their impact in ED, the hospital and the community. Quantifiable resource changes were assigned a financial value and grouped...... into categories: structure (facilities/beds), staff and processes. Simple statistics were used to describe the data, and the correlation between expenditure and target performance was determined. Results There was 100% response to the survey. Most DHBs reported some expenditure specifically on the target...

  9. Targeting dendritic cells--why bother?

    Science.gov (United States)

    Kreutz, Martin; Tacken, Paul J; Figdor, Carl G

    2013-04-11

    Vaccination is among the most efficient forms of immunotherapy. Although sometimes inducing lifelong protective B-cell responses, T-cell-mediated immunity remains challenging. Targeting antigen to dendritic cells (DCs) is an extensively explored concept aimed at improving cellular immunity. The identification of various DC subsets with distinct functional characteristics now allows for the fine-tuning of targeting strategies. Although some of these DC subsets are regarded as superior for (cross-) priming of naive T cells, controversies still remain about which subset represents the best target for immunotherapy. Because targeting the antigen alone may not be sufficient to obtain effective T-cell responses, delivery systems have been developed to target multiple vaccine components to DCs. In this Perspective, we discuss the pros and cons of targeting DCs: if targeting is beneficial at all and which vaccine vehicles and immunization routes represent promising strategies to reach and activate DCs.

  10. Preliminary study of mercury target structure

    Energy Technology Data Exchange (ETDEWEB)

    Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kumasaka, Katsuyuki; Uchida, Shoji; Nakagawa, Toshi; Mori, Seiji; Nishikawa, Akira

    1997-11-01

    Development of a proton accelerator based neutron source (1.5 GeV, 5.3 mA (for neutron source 3.3 mA), thermal power 8 MW) is currently conducted by the Special Task Force for Neutron Science Initiative, JAERI. Preliminary design studies and related R and D of a solid metal target for the first stage (1.5 GeV, 1 mA) and a liquid metal target for both the first and second stages (1.5 GeV, 3.3 mA) are conducted by the Target Group to develop both solid and liquid metal target systems. A few kinds of target structures have been investigated in FY 1996 and the preliminary results for the target structures are described in this paper. Investigation results of alternative materials for the target container are also described in this paper. (author)

  11. Governing by targets : Reductio ad unum and evolution of the two-degree climate target

    NARCIS (Netherlands)

    Morseletto, Piero; Biermann, Frank|info:eu-repo/dai/nl/176991662; Pattberg, Philipp

    2017-01-01

    Targets are widely employed in environmental governance. In this paper, we investigate the construction of the 2 °C climate target, one of the best known targets in global environmental governance. Our paper examines this target through a historical reconstruction that identifies four different

  12. Using the Dual-Target Cost to Explore the Nature of Search Target Representations

    Science.gov (United States)

    Stroud, Michael J.; Menneer, Tamaryn; Cave, Kyle R.; Donnelly, Nick

    2012-01-01

    Eye movements were monitored to examine search efficiency and infer how color is mentally represented to guide search for multiple targets. Observers located a single color target very efficiently by fixating colors similar to the target. However, simultaneous search for 2 colors produced a dual-target cost. In addition, as the similarity between…

  13. Target definition for shipwreck hunting

    Directory of Open Access Journals (Sweden)

    Kim Paul Kirsner

    2015-10-01

    Full Text Available The research described in the present article was implemented to define the locations of two World War II shipwrecks, the German raider Kormoran, and the Australian light cruiser HMAS Sydney. The paper describes the long and complex trail that led through inefficient oceanographic prediction to ambiguous historical prediction involving a single report and on to precise cognitive prediction based on nine reports from more than 70 survivors, a process that yielded a single target position or ‘mean’ just 2.7 NM (nautical miles from the wreck of Kormoran. Prediction for the position of the wreck of Sydney opened with wishful thinking that she had somehow reached the coast more than 100 NM away when cognitive analysis of the survivor’s reports actually provided the basis for accurate prediction in a position near to the wreck of Kormoran. In the account provided below, the focus on cognitive procedures emerged from, first, a review of a sample of the shipwreck hunts, and, second, growing awareness of the extraordinarily rich database available for this search, and the extent to which it was open to cognitive analysis. This review touches on both the trans-disciplinary and the cognitive or intra-disciplinary issues that so challenged the political entities responsible for supervising of the search for the wrecks of Kormoran and Sydney. One of the theoretical questions that emerged from these debate concerns the model of expertise advanced by Collins (2013. The decomposability of alleged forms of expertise is revealed as a fundamental problem for research projects that might or might not benefit from trans-disciplinary research. Where expertise can be decomposed for operational purposes, the traditional dividing lines between experts and novices, and fools for that matter, are much harder to discern, and require advanced and scientifically informed review.

  14. Target definition for shipwreck hunting.

    Science.gov (United States)

    Kirsner, Kim

    2015-01-01

    The research described in the present article was implemented to define the locations of two World War II shipwrecks, the German raider Kormoran, and the Australian light cruiser HMAS Sydney. The paper describes the long and complex trail that led through inefficient oceanographic prediction to ambiguous historical prediction involving a single report and on to precise cognitive prediction based on nine reports from more than 70 survivors, a process that yielded a single target position or "mean" just 2.7 NM (nautical miles) from the wreck of Kormoran. Prediction for the position of the wreck of Sydney opened with wishful thinking that she had somehow reached the coast more than 100 NM away when cognitive analysis of the survivor's reports actually provided the basis for accurate prediction in a position near to the wreck of Kormoran. In the account provided below, the focus on cognitive procedures emerged from, first, a review of a sample of the shipwreck hunts, and, second, growing awareness of the extraordinarily rich database available for this search, and the extent to which it was open to cognitive analysis. This review touches on both the trans-disciplinary and the cognitive or intra-disciplinary issues that so challenged the political entities responsible for supervising of the search for the wrecks of Kormoran and Sydney. One of the theoretical questions that emerged from these debate concerns the model of expertise advanced by Collins (2013). The decomposability of alleged forms of expertise is revealed as a fundamental problem for research projects that might or might not benefit from trans-disciplinary research. Where expertise can be decomposed for operational purposes, the traditional dividing lines between experts and novices, and fools for that matter, are much harder to discern, and require advanced and scientifically informed review.

  15. Therapeutic targeting of replicative immortality.

    Science.gov (United States)

    Yaswen, Paul; MacKenzie, Karen L; Keith, W Nicol; Hentosh, Patricia; Rodier, Francis; Zhu, Jiyue; Firestone, Gary L; Matheu, Ander; Carnero, Amancio; Bilsland, Alan; Sundin, Tabetha; Honoki, Kanya; Fujii, Hiromasa; Georgakilas, Alexandros G; Amedei, Amedeo; Amin, Amr; Helferich, Bill; Boosani, Chandra S; Guha, Gunjan; Ciriolo, Maria Rosa; Chen, Sophie; Mohammed, Sulma I; Azmi, Asfar S; Bhakta, Dipita; Halicka, Dorota; Niccolai, Elena; Aquilano, Katia; Ashraf, S Salman; Nowsheen, Somaira; Yang, Xujuan

    2015-12-01

    One of the hallmarks of malignant cell populations is the ability to undergo continuous proliferation. This property allows clonal lineages to acquire sequential aberrations that can fuel increasingly autonomous growth, invasiveness, and therapeutic resistance. Innate cellular mechanisms have evolved to regulate replicative potential as a hedge against malignant progression. When activated in the absence of normal terminal differentiation cues, these mechanisms can result in a state of persistent cytostasis. This state, termed "senescence," can be triggered by intrinsic cellular processes such as telomere dysfunction and oncogene expression, and by exogenous factors such as DNA damaging agents or oxidative environments. Despite differences in upstream signaling, senescence often involves convergent interdependent activation of tumor suppressors p53 and p16/pRB, but can be induced, albeit with reduced sensitivity, when these suppressors are compromised. Doses of conventional genotoxic drugs required to achieve cancer cell senescence are often much lower than doses required to achieve outright cell death. Additional therapies, such as those targeting cyclin dependent kinases or components of the PI3K signaling pathway, may induce senescence specifically in cancer cells by circumventing defects in tumor suppressor pathways or exploiting cancer cells' heightened requirements for telomerase. Such treatments sufficient to induce cancer cell senescence could provide increased patient survival with fewer and less severe side effects than conventional cytotoxic regimens. This positive aspect is countered by important caveats regarding senescence reversibility, genomic instability, and paracrine effects that may increase heterogeneity and adaptive resistance of surviving cancer cells. Nevertheless, agents that effectively disrupt replicative immortality will likely be valuable components of new combinatorial approaches to cancer therapy. Copyright © 2015 The Authors

  16. Target detection and tracking in infrared video

    Science.gov (United States)

    Deng, Zhihui; Zhu, Jihong

    2017-07-01

    In this paper, we propose a method for target detection and tracking in infrared video. The target is defined by its location and extent in a single frame. In the initialization process, we use an adaptive threshold to segment the target and then extract the fern feature and normalize it as a template. The detector uses the random forest and fern to detect the target in the infrared video. The random forest and fern is a random combination of 2bit Binary Pattern, which is robust to infrared targets with blurred and unknown contours. The tracker uses the gray-value weighted mean-Shift algorithm to track the infrared target which is always brighter than the background. And the tracker can track the deformed target efficiently and quickly. When the target disappears, the detector will redetect the target in the coming infrared image. Finally, we verify the algorithm on the real-time infrared target detection and tracking platform. The result shows that our algorithm performs better than TLD in terms of recall and runtime in infrared video.

  17. Fluid mechanics aspects of magnetic drug targeting.

    Science.gov (United States)

    Odenbach, Stefan

    2015-10-01

    Experiments and numerical simulations using a flow phantom for magnetic drug targeting have been undertaken. The flow phantom is a half y-branched tube configuration where the main tube represents an artery from which a tumour-supplying artery, which is simulated by the side branch of the flow phantom, branches off. In the experiments a quantification of the amount of magnetic particles targeted towards the branch by a magnetic field applied via a permanent magnet is achieved by impedance measurement using sensor coils. Measuring the targeting efficiency, i.e. the relative amount of particles targeted to the side branch, for different field configurations one obtains targeting maps which combine the targeting efficiency with the magnetic force densities in characteristic points in the flow phantom. It could be shown that targeting efficiency depends strongly on the magnetic field configuration. A corresponding numerical model has been set up, which allows the simulation of targeting efficiency for variable field configuration. With this simulation good agreement of targeting efficiency with experimental data has been found. Thus, the basis has been laid for future calculations of optimal field configurations in clinical applications of magnetic drug targeting. Moreover, the numerical model allows the variation of additional parameters of the drug targeting process and thus an estimation of the influence, e.g. of the fluid properties on the targeting efficiency. Corresponding calculations have shown that the non-Newtonian behaviour of the fluid will significantly influence the targeting process, an aspect which has to be taken into account, especially recalling the fact that the viscosity of magnetic suspensions depends strongly on the magnetic field strength and the mechanical load.

  18. Resistance to Antibiotics Mediated by Target Alterations

    Science.gov (United States)

    Spratt, Brian G.

    1994-04-01

    The development of resistance to antibiotics by reductions in the affinities of their enzymatic targets occurs most rapidly for antibiotics that inactivate a single target and that are not analogs of substrate. In these cases of resistance (for example, resistance to rifampicin), numerous single amino acid substitutions may provide large decreases in the affinity of the target for the antibiotic, leading to clinically significant levels of resistance. Resistance due to target alterations should occur much more slowly for those antibiotics (penicillin, for example) that inactivate multiple targets irreversibly by acting as close analogs of substrate. Resistance to penicillin because of target changes has emerged, by unexpected mechanisms, only in a limited number of species. However, inactivating enzymes commonly provide resistance to antibiotics that, like penicillin, are derived from natural products, although such enzymes have not been found for synthetic antibiotics. Thus, the ideal antibiotic would be produced by rational design, rather than by the modification of a natural product.

  19. High power target developments at ISAC

    CERN Document Server

    Bricault, P G; Dowling, A; Lane, M

    2003-01-01

    TRIUMF, Canada's national research facility for particle and nuclear physics is currently operating the ISAC facility. A high-energy proton beam from the H sup - TRIUMF cyclotron is used to generate short-lived radioactive species in a thick target. An ion source at the target creates a radioactive beam, which is then injected into the ISAC beam lines and accelerator system. The ISAC facility is designed to accept proton beam intensity up to 100 mu A at 500 MeV. At present our target design can only sustains 40 mu A at maximum. Beyond this point the target has to be cooled. A new target equipped with fins has been developed that may sustain proton beam up to 100 mu A. The fined target has been tested off-line and a thermal simulation using ANSYS[reg] has been conducted and the results are reported here.

  20. Neutronic characterization of the MEGAPIE target

    Energy Technology Data Exchange (ETDEWEB)

    Panebianco, Stefano; David, Jean-Christophe; Leray, Sylvie; Letourneau, Alain; Michel-Sendis, Franco; Stankunas, Gediminas [CEA/IRFU, Gif-sur-Yvette (France); Berg, Klara; Filges, Uwe; Groeschel, Friedrich; Luethy, Markus; Scazzi, Selene; Tobler, Leonhard; Zanini, Luca [PSI, Villigen (Switzerland); Eid, Mohamed [CEA/DEN/DM2S/SERMA, Gif-sur-Yvette (France); Guertin, Arnaud; Thiolliere, Nicolas [SUBATECH, Nantes (France); Konobeyev, Alexander Yu. [FZK/IRS, Karlsruhe (Germany); Latge, Christian [CEA/DEN/DTN/DIR, St. Paul Lez Durance (France); Lemaire, Sebastien [CEA/DAM/DCSA/SCGA, Bruyeres-le-Chatel (France)

    2008-07-01

    The MEGAPIE project aimed to design, build and operate a liquid metal spallation neutron target of 1 MW beam power in the SINQ facility at the Paul Scherrer Institut (Villigen, Switzerland). The project is an important step in the road-map towards the demonstration of the Accelerator Driven System (ADS) concept and high power liquid metal targets in general. Following the design phase, an experimental program was defined to provide a complete characterization of the facility by performing a 'mapping' of the neutron flux at different points, from the center of the target to the beam lines. The neutronic performance of the target was studied using different experimental techniques with the goals of validating the Monte Carlo codes used in the design of the target; additionally, the performance was compared with the solid lead targets used before and after the MEGAPIE experiment. (authors)