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Sample records for aluminum ions induce

  1. A novel method for study of the aggregation of protein induced by metal ion aluminum(III) using resonance Rayleigh scattering technique

    Science.gov (United States)

    Long, Xiufen; Zhang, Caihua; Cheng, Jiongjia; Bi, Shuping

    2008-01-01

    We present a novel method for the study of the aggregation of protein induced by metal ion aluminum(III) using resonance Rayleigh scattering (RRS) technique. In neutral Tris-HCl medium, the effect of this aggregation of protein results in the enhancement of RRS intensity and the relationship between the enhancement of the RRS signal and the Al concentration is nonlinear. On this basis, we established a new method for the determination of the critical induced-aggregation concentrations ( CCIAC) of metal ion Al(III) inducing the protein aggregation. Our results show that many factors, such as, pH value, anions, salts, temperature and solvents have obvious effects. We also studied the extent of aggregation and structural changes using ultra-violet spectrometry, protein intrinsic fluorescence and circular dichroism to further understand the exact mechanisms of the aggregation characteristics of proteins induced by metal ion Al(III) at the molecular level, to help us to develop effective methods to investigate the toxicity of metal ion Al, and to provide theoretical and quantitative evidences for the development of appropriate treatments for neurodementia such as Parkinson's disease, Alzheimer's disease and dementia related to dialysis.

  2. Aluminum-induced granulomas in a tattoo

    Energy Technology Data Exchange (ETDEWEB)

    McFadden, N.; Lyberg, T.; Hensten-Pettersen, A.

    1989-05-01

    A patient who developed localized, granulomatous reactions in a tattoo is described. With the use of scanning electron microscopy and energy dispersive x-ray microanalysis, both aluminum and titanium particles were found in the involved skin sections. Intradermal provocation testing with separate suspensions of aluminum and titanium induced a positive response only in the case of aluminum. Examination by scanning electron microscopy and energy dispersive x-ray microanalysis of the provoked response established aluminum as the only nonorganic element present in the test site tissue. This is the first report of confirmed aluminum-induced, delayed-hypersensitivity granulomas in a tattoo.

  3. Energy transfer among rare earth ions induced by annealing process of Tm sbnd Er codoped aluminum oxide thin films

    Science.gov (United States)

    Xiao, Zhisong; Zhou, Bo; Xu, Fei; Zhu, Fang; Yan, Lu; Zhang, Feng; Huang, Anping

    2009-02-01

    Er sbnd Tm codoped amorphous aluminum oxide (a-Al 2O 3) thin films have been prepared by pulsed laser deposition. Efficient photoluminescence (PL) in the region of 1400-1700 nm with two peaks centered at 1533 nm and 1620 nm were observed with pumping at the wavelength of 791 nm. The PL performance has been investigated as a function of annealing temperature, which was varied from 650 to 850 °C in air. Infrared emission was improved by annealing, and energy transfer processes occurred obviously for annealing temperatures between 800 and 850 °C. All possible energy transfer channels were investigated and our results suggest that the quasi-resonant energy transfer and cross relaxation between Tm 3+ and Er 3+ play an important role in the evolution of the luminescent response.

  4. Fabrication of anodic aluminum oxide with incorporated chromate ions

    Science.gov (United States)

    Stępniowski, Wojciech J.; Norek, Małgorzata; Michalska-Domańska, Marta; Bombalska, Aneta; Nowak-Stępniowska, Agata; Kwaśny, Mirosław; Bojar, Zbigniew

    2012-10-01

    The anodization of aluminum in 0.3 M chromic acid is studied. The influence of operating conditions (like anodizing voltage and electrolyte's temperature) on the nanoporous anodic aluminum oxide geometry (including pore diameter, interpore distance, the oxide layer thickness and pores density) is thoroughly investigated. The results revealed typical correlations of the anodic alumina nanopore geometry with operating conditions, such as linear increase of pore diameter and interpore distance with anodizing voltage. The anodic aluminum oxide is characterized by a low pores arrangement, as determined by Fast Fourier transforms analyses of the FE-SEM images, which translates into a high concentration of oxygen vacancies. Moreover, an optimal experimental condition where chromate ions are being successfully incorporated into the anodic alumina walls, have been determined: the higher oxide growth rate the more chromate ions are being trapped. The trapped chromate ions and a high concentration of oxygen vacancies make the anodic aluminum oxide a promising luminescent material.

  5. Poly-Si films with low aluminum dopant containing by aluminum-induced crystallization

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Typically, highly p-doped (2×10 18 cm -3 ) poly-Si films fabricated by the aluminum induced layer exchange (ALILE) process are not suitable for solar cell absorber layers. In this paper, the fabrication of high-quality, continuous polycrystalline silicon (poly-Si) films with lower doping concentrations (2×10 16 cm -3 ) using aluminum-induced crystallization (AIC) is reported. Secondary-ion-mass spectroscopy (SIMS) results showed that annealing at different temperature profiles leads to a variety of Al concentrations. Hall Effect measurements revealed that Al dopant concentration depends on the annealing temperature and temperature profile. Raman spectral analysis indicated that samples prepared via AIC contain some regions with small grains.

  6. Aluminum ion electrolyte for enhanced electrochromism of polyaniline

    Science.gov (United States)

    Yao, Peijian; Ye, Meidan; Guo, Wenxi; Liu, Xiangyang

    2017-08-01

    Electrolytes influence the electrochemical behaviors of active materials in the electrochromism. In our work, it is demonstrated that the trivalent ion, aluminum ion (Al3+), can be used as an efficient insertion ion of polyaniline (PANI) electrodeposited on the FTO-coated glass, which brings the desired large optical contrast (ΔT), long-term cyclic (coloration/bleaching) stability and high coloration efficiency compared with that based on the H+ electrolyte. Differing from the usual degradation by repeated doping/dedoping, the Al3+ insertion may introduce strong electrostatic forces, which on some degree stabilize the polymer chain structure and consequently yield enhanced electrochromic performances.

  7. The rechargeable aluminum-ion battery.

    Science.gov (United States)

    Jayaprakash, N; Das, S K; Archer, L A

    2011-12-21

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl(3) in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V(2)O(5) nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g(-1) in the first cycle and 273 mAh g(-1) after 20 cycles, with very stable electrochemical behaviour.

  8. The rechargeable aluminum-ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Navaneedhakrishnan, Jayaprakash; Das, Shyamal K; Archer, Lynden A.

    2011-01-01

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl₃ in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V₂O₅ nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g⁻¹ in the first cycle and 273 mAh g⁻¹ after 20 cycles, with very stable electrochemical behaviour.

  9. The rechargeable aluminum-ion battery

    KAUST Repository

    Jayaprakash, N.

    2011-01-01

    We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl3 in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V2O5 nano-wire cathode against an aluminium metal anode. The battery delivered a discharge capacity of 305 mAh g-1 in the first cycle and 273 mAh g-1 after 20 cycles, with very stable electrochemical behaviour. © The Royal Society of Chemistry 2011.

  10. Poly-crystalline thin-film by aluminum induced crystallization on aluminum nitride substrate

    Science.gov (United States)

    Bhopal, Muhammad Fahad; Lee, Doo Won; Lee, Soo Hong

    2016-09-01

    Thin-film polycrystalline silicon ( pc-Si) on foreign (non-silicon) substrates has been researched by various research groups for the production of photovoltaic cells. High quality pc-Si deposition on foreign substrates with superior optical properties is considered to be the main hurdle in cell fabrication. Metal induced crystallization (MIC) is one of the renowned techniques used to produce this quality of material. In the current study, an aluminum induced crystallization (AIC) method was adopted to produce pc-Si thin-film on aluminum nitride (AlN) substrate by a seed layer approach. Aluminum and a-Si layer were deposited using an e-beam evaporator. Various annealing conditions were used in order to investigate the AIC grown pc-Si seed layers for process optimization. The effect of thermal annealing on grain size, defects preferentially crystallographic orientation of the grains were analyzed. Surface morphology was studied using an optical microscope. Poly-silicon film with a crystallinity fraction between 95-100% and an FWHM between 5-6 cm-1 is achievable at low temperatures and for short time intervals. A grain size of about 10 micron can be obtained at a low deposition rate on an AIN substrate. Similarly, Focused ion beam (FIB) also showed that at 425 °C sample B and at 400 °C sample A were fully crystallized. The crystalline quality of pc-Si was evaluated using μ-Raman spectroscopy as a function of annealed conditions and Grazing incidence X-ray diffraction (GIXRD) was used to determine the phase direction of the pc-Si layer. The current study implicates that a poly-silicon layer with good crystallographic orientation and crystallinity fraction is achievable on AIN substrate at low temperatures and short time frames.

  11. The Corrosion Protection of Metals by Ion Vapor Deposited Aluminum

    Science.gov (United States)

    Danford, M. D.

    1993-01-01

    A study of the corrosion protection of substrate metals by ion vapor deposited aluminum (IVD Al) coats has been carried out. Corrosion protection by both anodized and unanodized IVD Al coats has been investigated. Base metals included in the study were 2219-T87 Al, 7075-T6 Al, Titanium-6 Al-4 Vanadium (Ti-6Al-4V), 4130 steel, D6AC steel, and 4340 steel. Results reveal that the anodized IVD Al coats provide excellent corrosion protection, but good protection is also achieved by IVD Al coats that have not been anodized.

  12. Two-dimensional thermal simulations of aluminum and carbon ion strippers for experiments at SPIRAL2 using the highest beam intensities

    Energy Technology Data Exchange (ETDEWEB)

    Tahir, N.A., E-mail: n.tahir@gsi.de [GSI Helmholzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Kim, V. [Institute of Problems of Chemical Physics, Chernogolovka (Russian Federation); Lamour, E. [Institut des NanoSciences de Paris, UPMC-Sorbonne Universite, CNRS-UMR 7588, 75252 Paris (France); Lomonosov, I.V. [Institute of Problems of Chemical Physics, Chernogolovka (Russian Federation); Piriz, A.R. [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Rozet, J.P. [Institut des NanoSciences de Paris, UPMC-Sorbonne Universite, CNRS-UMR 7588, 75252 Paris (France); Stoehlker, Th. [GSI Helmholzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Helmholz-Institut Jena, 07743 Jena (Germany); Sultanov, V. [Institute of Problems of Chemical Physics, Chernogolovka (Russian Federation); Vernhet, D. [Institut des NanoSciences de Paris, UPMC-Sorbonne Universite, CNRS-UMR 7588, 75252 Paris (France)

    2012-11-01

    In this paper we report on two-dimensional numerical simulations of heating of a rotating, wheel shaped target impacted by the full intensity of the ion beam that will be delivered by the SPIRAL2 facility at Caen, France. The purpose of this work is to study heating of solid targets that will be used to strip the fast ions of SPIRAL2 to the required high charge state for the FISIC (Fast Ion-Slow Ion Collision) experiments. Strippers of aluminum with different emissivities and of carbon are exposed to high beam current of different ion species as oxygen, neon and argon. These studies show that carbon, due to its much higher sublimation temperature and much higher emissivity, is more favorable compared to aluminum. For the highest beam intensities, an aluminum stripper does not survive. However, problem of the induced thermal stresses and long term material fatigue needs to be investigated before a final conclusion can be drawn.

  13. The Substitution of IVD (Ion Vapor Deposition) Aluminum for Cadmium

    Science.gov (United States)

    1989-08-01

    Additional information on the usage of IVU aluminum in contact with fuels , oils, and other fluids is found in Section VIF). Cadmium coatings are also...RESTRICTIVE MARKINGS UNCLASSIFIED 2a. SECUR :7Y CLASSIFICATION AU7-77RI7 3 DiSTRIBUTION , AVAILABILTY OF REPORT Approved for public release. 2b...FiUURES (CUNTINULD) Figure Pa’te 37 IVO Aluminum-Coated Aluminum Alloy Fuel and Pneumatic Line Fittings ............ ............................ 7b 38

  14. Inhibition of transducin activation and guanosine triphosphatase activity by aluminum ion.

    Science.gov (United States)

    Miller, J L; Hubbard, C M; Litman, B J; Macdonald, T L

    1989-01-05

    Aluminum ion perturbs the activity of a number of physiologically important enzymes, including members of a family of guanine nucleotide-binding proteins (G-proteins). G-proteins couple cellular receptor proteins to a variety of effector enzymes (including adenylate cyclase, phospholipase C, and the rod photoreceptor phosphodiesterase). We show herein that subnanomolar concentrations of free aluminum ion, produced in a carefully defined and kinetically stable manner through the buffering of total aluminum at 0.1-1.0 mM with calculated ratios of chelating agents, inhibit both the receptor-mediated activation and the self-inactivating GTPase activity of the rod photoreceptor G-protein, Gv. In the presence of 4 X 10(-10) M free aluminum ion, GTPase activity is inhibited from about 25-60% as the magnesium ion concentration is reduced from 10(-3) to about 5 X 10(-5) M. The principal effect of aluminum ion upon Gv is to inhibit receptor catalyzed nucleotide exchange. Binding of the GTP analog 5'-guanylyl imidodiphosphate can be reduced by as much as 90% by aluminum ion following subsaturating rhodopsin stimulation. Aluminum ion can produce either competitive or mixed noncompetitive inhibition of rhodopsin-catalyzed Gv activation and GTPase activity, as a function of whether Gv undergoes single (competitive), or multiple (mixed noncompetitive) nucleotide exchanges. The rod photoreceptor phosphodiesterase is only slightly inhibited by similar aluminum ion activities. Light- and Gv-coupled phosphodiesterase activation exhibits both a lower maximum rate of cyclic guanosine monophosphate hydrolysis and a slower inactivation in the presence of aluminum ion activities from about 10(-12) - 10(-10) M. These data suggest that intracellular free aluminum ion concentrations in the subnanomolar range could markedly affect the ability of cells to transduce extracellular signals. Interestingly, the combination of Al3+ and F- to produce the fluoro-aluminate species (AlFx) also inhibits

  15. Role of low-energy ion irradiation in the formation of an aluminum germanate layer on a germanium substrate by radical-enhanced atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Yukio, E-mail: y-fukuda@rs.suwa.tus.ac.jp; Yamada, Daichi; Yokohira, Tomoya; Yanachi, Kosei [Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino, Nagano 391-0292 (Japan); Yamamoto, Chiaya; Yoo, Byeonghak; Sato, Tetsuya [University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Yamanaka, Junji [University of Yamanashi, 7-32 Miyamae, Kofu, Yamanashi 400-8511 (Japan); Takamatsu, Toshiyuki [SST Inc., 989-6 Shimadadai, Yachiyo, Chiba 276-0004 (Japan); Okamoto, Hiroshi [Hirosaki University, 3 Bunkyo, Hirosaki 036-8561 (Japan)

    2016-03-15

    Radical-enhanced atomic layer deposition uses oxygen radicals generated by a remote microwave-induced plasma as an oxidant to change the surface reactions of the alternately supplied trimethylaluminum precursor and oxygen radicals on a Ge substrate, which leads to the spontaneous formation of an aluminum germanate layer. In this paper, the effects that low-energy ions, supplied from a remote microwave plasma to the substrate along with the oxygen radicals, have on the surface reactions were studied. From a comparative study of aluminum oxide deposition under controlled ion flux irradiation on the deposition surface, it was found that the ions enhance the formation of the aluminum germanate layer. The plasma potential measured at the substrate position by the Langmuir probe method was 5.4 V. Assuming that the kinetic energy of ions arriving at the substrate surface is comparable to that gained by this plasma potential, such ions have sufficient energy to induce exchange reactions of surface-adsorbed Al atoms with the underlying Ge atoms without causing significant damage to the substrate. This ion-induced exchange reaction between Al and Ge atoms is inferred to be the background kinetics of the aluminum germanate formation by radical-enhanced atomic layer deposition.

  16. SPS Ion Induced Desorption Experiment

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    This experiment will give a study about the induced desorption from heavy ion (Indium ion run from week 45 in SPS T4-H8 area) impacting LHC type graphite collimator. 4 different samples are located in the 4 chambers 90° one to each other: pure graphite, graphite with copper coating, graphite with NEG coating, 316LN stainless steal (reference).

  17. Revisiting the Corrosion of the Aluminum Current Collector in Lithium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Tianyuan; Xu, Gui-Liang; Li, Yan; Wang, Li; He, Xiangming; Zheng, Jianming; Liu, Jun; Engelhard, Mark H.; Zapol, Peter; Curtiss, Larry A.; Jorne, Jacob; Amine, Khalil; Chen, Zonghai

    2017-02-20

    The corrosion of aluminum current collectors and the oxidation of solvents at a relatively high potential have been widely investigated with an aim to stabilize the electrochemical performance of lithium-ion batteries using such components. The corrosion behavior of aluminum current collectors was revisited using a home-build high-precision electrochemical measurement system, and the impact of electrolyte components and the surface protection layer on aluminum foil was systematically studied. The electrochemical results showed that the corrosion of aluminum foil was triggered by the electrochemical oxidation of solvent molecules, like ethylene carbonate, at a relative high potential. The organic radical cations generated from the electrochemical oxidation are energetically unstable, and readily undergo a deprotonation reaction that generates protons and promote the dissolution of Al3+ from the aluminum foil. This new reaction mechanism can also shed light on the dissolution of transitional metal at high potentials.

  18. Aluminum work function: Effect of oxidation, mechanical scraping and ion bombardment

    Science.gov (United States)

    Vinet, P.; Lemogne, T.; Montes, H.

    1985-01-01

    Surface studies have been performed on aluminum polycrystalline surfaces which have been mechanically scraped. Such studies were initiated in order to understand surface effects occurring in tribological processes which involve rubbing surfaces and the effects of adsorption of oxygen. To characterize the surfaces, the following three different experimental approaches have been used: (1) X.P.S. (X-ray photoelectron spectroscopy), in order to check the cleanliness of the surfaces and follow the adsorption and oxidation kinetics; (2) Analysis of the work function changes by following the energy spectra of secondary electrons emitted under low energy electron bombardment; and (3) Analysis of photoemission intensities under U.V. excitation. The reference state being chosen to be the surface cleaned by ion bombardment and exposures to oxygen atmospheres have been shown to lower the work function of clean polycrystalline aluminum by 1.2 eV. The oxygen pressure is found to affect only the kinetics of these experiments. Mechanical scraping has been shown to induce a decrease ( 0.3 eV) in the work function, which could sharply modify the kinetics of adsorption on the surface.

  19. Ion Flux in Roots of Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook) under Aluminum Stress

    OpenAIRE

    2016-01-01

    Chinese fir is a tall, fast-growing species that is unique to southern China. In Chinese fir plantations, successive plantings have led to a decline in soil fertility, and aluminum toxicity is thought to be one of the main reasons for this decline. In this study, Non-invasive Micro-test Technology was used to study the effect of aluminum stress on the absorption of 4 different ions in the roots of the Chinese fir clone FS01. The results are as follows: with increased aluminum concentration an...

  20. High-Performance Aluminum-Ion Battery with CuS@C Microsphere Composite Cathode.

    Science.gov (United States)

    Wang, Shuai; Jiao, Shuqiang; Wang, Junxiang; Chen, Hao-Sen; Tian, Donghua; Lei, Haiping; Fang, Dai-Ning

    2017-01-24

    On the basis of low-cost, rich resources, and safety performance, aluminum-ion batteries have been regarded as a promising candidate for next-generation energy storage batteries in large-scale energy applications. A rechargeable aluminum-ion battery has been fabricated based on a 3D hierarchical copper sulfide (CuS) microsphere composed of nanoflakes as cathode material and room-temperature ionic liquid containing AlCl3 and 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl) as electrolyte. The aluminum-ion battery with a microsphere electrode exhibits a high average discharge voltage of ∼1.0 V vs Al/AlCl4(-), reversible specific capacity of about 90 mA h g(-1) at 20 mA g(-1), and good cyclability of nearly 100% Coulombic efficiency after 100 cycles. Such remarkable electrochemical performance is attributed to the well-defined nanostructure of the cathode material facilitating the electron and ion transfer, especially for chloroaluminate ions with large size, which is desirable for aluminum-ion battery applications.

  1. Combustion Characteristics of Hydrocarbon Droplets Induced by Photoignition of Aluminum Nanoparticles (Conference Paper with Briefing Charts)

    Science.gov (United States)

    2017-04-23

    Hydrocarbon Droplets Induced by Photoignition of Aluminum Nanoparticles (Conference Paper with Briefing Charts) John Bennewitz, Alireza Badakhshan, and...droplets has been achieved through photoignition (PI) utilizing sub milligram of aluminum nanoparticles (Al NPs). For diesel fuel, a reliable ignition...Droplets Induced by Photoignition of Aluminum Nanoparticles Alireza Badakhshan1,*, John W. Bennewitz2, Douglas G. Talley3 1Engineering Research

  2. Aluminum Ion Removal from Monoaluminum Ovotransferrin by Pyrophosphate

    Institute of Scientific and Technical Information of China (English)

    LI,Ying-Qi(李英奇); YANG,Bin-Sheng(杨斌盛)

    2004-01-01

    The rates at which aluminum was removed from the N- and C-terminal monoaluminum ovotransferrins by pyrophosphate were evaluated by UV difference spectra in 0.01 mol/L Hepes, pH=7.4 and at 37 ℃. Pesudo first-order rate constants as a function of pyrophosphate concentration were measured. The results indicate that the pathways of aluminum removal are different. For the N-terminal binding site, aluminum removal follows simple saturation kinetics, while the removal of aluminum from the C-terminal binding site reverts to the combination of saturation and first-order kinetics. The saturation component is consistent with a rate-limiting conformational change in the protein as has been reported. We propose that the first-order kinetics mechanism is attributed to a pre-equilibrium process. The rate constants of saturation kinetics are accelerated from both terminals with the addition of 0.1 mol/L chloride to the monoaluminum ovotransferrin solutions, whereas the rates of the first-order kinetics are decreased for the C-terminal binding site. The effect of chloride ionic strength causes a continuing increase on kobs for the N- and C-terminal binding sites. Moreover, the kinetics behavior of the N-terminal is more easily affected by chloride than that of the C-terminal. In the experiment presumably the N-terminal site is apparently kinetically more labile than the C-terminal site.

  3. 5-lipoxygenase expression in a brain damage model induced by chronic oral administration of aluminum

    Institute of Scientific and Technical Information of China (English)

    Yongquan Pan; Peng Zhang; Junqing Yang; Qiang Su

    2010-01-01

    A preliminary study has found that the 5-lipoxygenase inhibitor, caffeic acid, has a marked protective effect on acute brain injury induced by intracerebroventricular microinjection of aluminum.In this experiment, chronic brain injury and neuronal degeneration model was established in rats by chronic oral administration of aluminum, and then intervened using caffeic acid. Results showed that caffeic acid can downregulate chronic aluminum overload-induced 5-lipoxygenase mRNA and protein expression, and repair the aluminum overload-induced hippocampal neuronal damage andspatial orientation impairment. It is suggested that direct intervention of 5-lipoxygenase expression has a neuroprotective role in the degeneration induced by chronic aluminum overload brain injury model.

  4. Time-resolved laser-induced breakdown spectroscopy of aluminum

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-yun; ZHANG Wei-jun; WANG Zhen-ya; HAO Li-qing; HUANG Ming-qiang; ZHAO Wen-wu; LONG Bo; Zhao Wei

    2008-01-01

    We develop a system to measure the elemental composition of unprepared samples using laser-induced breakdown spectroscopy (LIBS) in our laboratory, which can be used for the determination of elements in solids, liquids and aerosols. A description of the instrumentation, including laser, sample chamber and detection, is followed by a brief discussion. The time-resolved LIBS of aluminum at atmospheric pressure is presented. At the end, the possibilities and later uses of this technique are briefly discussed.

  5. Temperature simulation of EMC aluminum ingot with induced heat

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The numerical simulation of temperature field of electromagnetic casting (EMC) aluminum ingots is an effective and also necessary approach to study the temperature field and forecast the quality of EMC ingot, or optimize the technological parameters. In EMC, the alternating electromagnetic field can produce induced current and heat within the surface layer. To calculate the temperature field precisely, the induced heat should be taken into account. The induced heat has been coupled into the calculation formula of temperature field of unit volume per unit time, which provides a convenient and also precise method to calculate the temperature field. Besides, the effect of induced heat on the temperature field of ingot has been simulated and discussed. The results show that the induced heat has large influences on the height of liquid column and the surface temperature of ingot.

  6. Radiation induced defects and thermoluminescence mechanism in aluminum oxide

    Energy Technology Data Exchange (ETDEWEB)

    Atobe, K.; Kobayashi, T.; Awata, T. [Naruto Univ. of Education, Tokushima (Japan); Okada, M. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst; Nakagawa, M. [Kagawa Univ., Faculty of Education, Takamatsu, Kagawa (Japan)

    2001-01-01

    The thermoluminescence of the irradiated aluminum oxides were measured to study the radiation induced defects and their behaviors. Neutron and {gamma}-ray irradiation were performed for a shingle crystal of the high purity aluminum oxide. The thermoluminescence glow curve and its activation energy were measured. The spectroscopy measurement on the thermoluminescence and the absorption are also carried out. The observed 430 and 340 nm peaks are discussed relating to the F{sup +} and F centers, respectively. Activation state of the F center transits to 3P state through 1P state by emitting phonons. Trapped electron on 3P state emits phonon of 2.9 eV (430 nm) during transition to the ground state. The above reaction can be written by the equation. F{sup +} + e {yields} (F){sup *} {yields} F + h{nu}(2.9 eV, 470 nm). (Katsuta, H.)

  7. On novel mechanisms of slow ion induced electron emission

    CERN Document Server

    Eder, H

    2000-01-01

    impact of singly and doubly charged ions on poly- and monocrystalline aluminum surfaces were performed. From the results we conclude that direct plasmon excitation by slow ions occurs due to the potential energy of the projectile in a quasi-resonant fashion. The highest relative plasmon intensities were found for impact of 5 keV Ne+ on Al(111) with 5 % of the total yield. For impact of H + and H sub 2 + characteristical differences were observed for Al(111) and polycrystalline aluminum. We show that structures in the spectrum for monocrystalline aluminum arise from diffraction of ejected electrons instead of plasmon excitation as previously assumed. The present work has contributed in new ways to the field of slow ion induced electron emission. First, measurements of the total electron yield gamma for impact of slow singly and multiply charged ions on atomically clean polycrystalline gold and graphite have been made. The respective yields were determined by current measurements and measurements of the electro...

  8. Binary collision model for neon Auger spectra from neon ion bombardment of the aluminum surface

    Science.gov (United States)

    Pepper, S. V.

    1986-01-01

    A model is developed to account for the angle-resolved Auger spectra from neon ion bombardment of the aluminum surface recently obtained by Pepper and Aron. The neon is assumed to be excited in a single asymmetric neon-aluminum-collision and scattered back into the vacuum where it emits an Auger electron. The velocity of the Auger electron acquires a Doppler shift by virtue of the emission from a moving source. The dependence of the Auger peak shape and energy on the incident ion energy, angle of incidence and on the angle of Auger electron emission with respect to the surface is presented. Satisfactory agreement with the angle resolved experimental observations is obtained. The dependence of the angle-integrated Auger yield on the incident ion energy and angle of incidence is also obtained and shown to be in satisfactory agreement with available experimental evidence.

  9. Computer simulations of laser-induced melting of aluminum

    Science.gov (United States)

    Tang, Hong; Bai, Mingze; Dou, Yusheng; Ran, Qi; Lo, Glenn V.

    2013-04-01

    Laser-induced solid-to-liquid phase transitions in 100 nm aluminum film were simulated using a hybrid model that combines molecular dynamics (MD) with a continuum description of the laser excitation and a two-temperature method (TTM) to model the relaxation of conduction band electrons. When the laser fluence provides more energy than needed for a complete melting of the film, the phase transition is characterized by an ultrafast collapse of the crystal structure within 2-3 ps. Otherwise, the transition involves a homogeneous nucleation and growth of liquid zones inside the crystal and a heterogeneous propagation of transition fronts from the external surfaces or nucleated liquid zones.

  10. Binding and removal of aluminum ions in water by an algal biomass

    Energy Technology Data Exchange (ETDEWEB)

    Zimnik, P.R.; Sneddon, J.

    1988-08-01

    A preliminary study on the binding and removal of trace concentrations of aluminum ions in waters by two species of algae, Chlorella Pyrenoidosa and Chlorella Vulgaris, were investigated. Binding by the former was minimal over all pH ranges, but binding by the latter was effective with a maximum binding of 68% occurring at pH 5. Binding was lowered drastically below pH 2, and this may be used to remove aluminum from the algae. Optimum binding occurred after 20 minutes exposure time of algae to aluminum solution and 450 mg algae mass to 100 mL solution. Binding was reproducible and more efficient in waters with low suspended solids. High salt concentrations interfere with binding, and the Chlorella Vulgaris could be reused 7 times with washings between each binding before a noticeable decrease in binding efficiency was found.

  11. Vibration Durability Testing of Nickel Cobalt Aluminum Oxide (NCA Lithium-Ion 18650 Battery Cells

    Directory of Open Access Journals (Sweden)

    James Michael Hooper

    2016-04-01

    Full Text Available This paper outlines a study undertaken to determine if the electrical performance of Nickel Cobalt Aluminum Oxide (NCA 3.1 Ah 18650 battery cells can be degraded by road induced vibration typical of an electric vehicle (EV application. This study investigates if a particular cell orientation within the battery assembly can result in different levels of cell degradation. The 18650 cells were evaluated in accordance with Society of Automotive Engineers (SAE J2380 standard. This vibration test is synthesized to represent 100,000 miles of North American customer operation at the 90th percentile. This study identified that both the electrical performance and the mechanical properties of the NCA lithium-ion cells were relatively unaffected when exposed to vibration energy that is commensurate with a typical vehicle life. Minor changes observed in the cell’s electrical characteristics were deemed not to be statistically significant and more likely attributable to laboratory conditions during cell testing and storage. The same conclusion was found, irrespective of cell orientation during the test.

  12. Theoretical Studies of Dielectronic Recombination of Aluminum-Like Ions

    Science.gov (United States)

    Gorczyca, Tom; Abdel Naby, S. A.; Nikolic, D.; Badnell, N. R.; Savin, D. W.

    2008-05-01

    Dielectronic recombination (DR) is an important process occurring in astrophysical plasmas. DR is responsible for the charge state balance as well as the cooling of astrophysical plasmas, and it is the dominant electron-ion recombination process in both photoionized and collisionally-ionized plasmas. Accurate and reliable calculations for DR rate coefficients are needed to analyze the spectra obtained from astrophysical observations. Over the past few years, our group has computed reliable DR data for all isoelectronic sequences up through Mg-like ions using a state-of-the-art multiconfiguration Breit-Pauli (MCBP) distorted wave method. Recently, we have focused our work on the complex third-row M-shell isoelectronic sequences, especially Al-like. Although there exist some DR calculations for S IV, those were performed only within a non-relativistic LS-coupling approximation and for higher temperatures more suitable for collisionally-ionized plasmas but not for the lower temperatures appropriate for photoionized plasmas. Fe XIV DR calculations have been completed and tested against the Heidelberg heavy-ion Test Storage Ring facility measurements. MCBP cross sections and rate coefficients of a wide range of Al-like ions, computed using the AUTOSTRUCTURE suite of atomic structure and collision codes, will be presented. The effect of fine structure splitting in the ground state will be discussed, and comparisons against all available data, theoretical as well as experimental, will be shown. Our results are fitted into a simple formula for easier implementation into modeling codes used by the astrophysics community. This work was funded in part by NASA (APRA), NASA (SHP) SR&T, and UK PPARC grants.

  13. Supersonic laser-induced jetting of aluminum micro-droplets

    Energy Technology Data Exchange (ETDEWEB)

    Zenou, M. [Racah Institute of Physics and the Harvey M. Kruger Family Center for Nano-science and Nanotechnology, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Additive Manufacturing Lab, Orbotech Ltd., P.O. Box 215, 81101 Yavne (Israel); Sa' ar, A. [Racah Institute of Physics and the Harvey M. Kruger Family Center for Nano-science and Nanotechnology, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Kotler, Z. [Additive Manufacturing Lab, Orbotech Ltd., P.O. Box 215, 81101 Yavne (Israel)

    2015-05-04

    The droplet velocity and the incubation time of pure aluminum micro-droplets, printed using the method of sub-nanosecond laser induced forward transfer, have been measured indicating the formation of supersonic laser-induced jetting. The incubation time and the droplet velocity were extracted by measuring a transient electrical signal associated with droplet landing on the surface of the acceptor substrate. This technique has been exploited for studying small volume droplets, in the range of 10–100 femto-litters for which supersonic velocities were measured. The results suggest elastic propagation of the droplets across the donor-to-acceptor gap, a nonlinear deposition dynamics on the surface of the acceptor and overall efficient energy transfer from the laser beam to the droplets.

  14. Effects of Metal Ions on the Aluminum Electrodeposition from Ionic Liquids

    Science.gov (United States)

    Caporali, Stefano; Martinuzzi, Stefano M.; Von Czarnecki, Peter; Schubert, Thomas J. S.; Bardi, Ugo

    2017-01-01

    In this study, we report on the effects of three common transition metal ions, i.e., Ni2+, Cu2+ and Fe3+ on the electrodeposition of aluminum from a chloroaluminate ionic liquid, evaluated by means of electrochemical and morphological investigation. Aiming at the determination of the morphological and chemical effects on the aluminum coatings, variable amounts of ions were introduced into the electroplating bath. Thick (about 20 μm) Al coatings were obtained by direct deposition (galvanostatic, 10 mA cm2, 2 h) on brass or carbon steel substrates (10 mm diameter disks), and their morphology was examined via rugosimetry, optical and electron microscopy. The chemical composition of the deposits was provided by EDX analysis. Nickel and iron resulted to have only moderate effects on the coatings properties, but copper affected the process even in tiny amounts being detected in the deposits for bath content as low as 10 ppm.

  15. Iss observations of aluminum surfaces under hydrogen ion bombardment

    Science.gov (United States)

    Sagara, A.; Kamada, K.; Higashida, Y.

    1984-12-01

    The shadowing effect of ISS was applied to observe the surface behavior of H atoms implanted with 500 eV/atom on a high-purity A1 sample. This study confirmed that this technique is powerful to observe the retention kinetics of H atoms especially on the topmost material surface with simultaneous analysis for surface contaminants such as oxygen during irradiation with hydrogen ions. The result obtained from the initially cleaned surface showed a remarkable increase in the H retention with increasing fluence of H2+ up to about 1018 H/cm2 at room temperature, depending on the fluence of predamage given by He+ ions, but showed no increase in the retention at the temperatures above 100 ° C. Therefore, because Al is a metal well known to be passive for chemisorption of H2 molecules and H atoms, it was concluded that the observed H retention originates from the traps produced by radiation damage. The activation energy for thermal desorption of the trapped H atoms was estimated to be 1.1±0.4 eV by ISS measurements. The oxygen-covered surface showed a rapid increase in the retention at fluence of less than 1017 H/cm2.

  16. [Aluminum induces chromosome aberrations in wheat root meristem cells].

    Science.gov (United States)

    Bulanova, N V; Synzynys, B I; Koz'min, G V

    2001-12-01

    The yield and pattern of chromosome structure aberrations in wheat seedlings treated with aluminum nitrate and aluminum sulfate at various concentrations have been determined by the anaphase method. Aluminum has a genotoxic effect causing genome, chromatid, and chromosome aberrations in apical root meristem cells. The relationship between the total yield of structural mutations and the aluminum concentration follows a bell-shaped curve. The mutagenic activity of aluminum nitrate peaks at 10(-3) mg/ml, which is twice as high as the permissible concentration limit (PCL) of aluminum in potable water. The maximum of the mutagenic activity of aluminum sulfate is observed at 5 x 10(-4) mg/ml, i.e., one PCL. Tap water boiled for 2 h in an aluminum vessel has virtually no genotoxic effect on wheat cells.

  17. Photoluminescence and Raman studies in swift heavy ion irradiated polycrystalline aluminum oxide

    Indian Academy of Sciences (India)

    K R Nagabhushana; B N Lakshminarasappa; Fouran Singh

    2009-10-01

    Polycrystalline aluminum oxide is synthesized by combustion technique and XRD studies of the sample revealed the -phase. The synthesized sample is irradiated with 120 MeV swift Au9+ ions for the fluence in the range from 1 × 1011 to 1 × 1013 ions cm-2. A broad photoluminescence (PL) emission with peak at ∼447 nm and two sharp emissions with peak at ∼ 679 and ∼ 695 nm are observed in pristine when sample was excited with 326 nm. However, in the irradiated samples the PL intensity at ∼ 447, 679 and 695 nm decreases with increase in ion fluence. The -Al2O3 gives rise to seven Raman modes with Raman intensity with peaks at ∼ 253, 396, 417, 546, 630, 842, 867 cm-1 observed in pristine. The intensity of these modes decreases with increase in ion fluence. However, the Raman modes observed at lower fluences are found to disappear at higher fluence.

  18. Intercalation of gaseous thiols and sulfides into Ag+ ion-exchanged aluminum dihydrogen triphosphate.

    Science.gov (United States)

    Hayashi, Aki; Saimen, Hiroki; Watanabe, Nobuaki; Kimura, Hitomi; Kobayashi, Ayumi; Nakayama, Hirokazu; Tsuhako, Mitsutomo

    2005-08-02

    Ag(+) ion-exchanged layered aluminum dihydrogen triphosphate (AlP) with the interlayer distance of 0.85 nm was synthesized by the ion-exchange of proton in triphosphate with Ag(+) ion. The amount of exchanged Ag(+) ion depended on the concentration of AgNO(3) aqueous solution. Ag(+) ion-exchanged AlP adsorbed gaseous thiols and sulfides into the interlayer region. The adsorption amounts of thiols were more than those of sulfides, thiols with one mercapto group > thiol with two mercapto groups > sulfides, and depended on the amount of exchanged Ag(+) ion in the interlayer region. The thiols with one mercapto group were intercalated to expand the interlayer distance of Ag(+) ion-exchanged AlP, whereas there was no expansion in the adsorption of sulfide. In the case of thiol with two mercapto groups, there was observed contraction of the interlayer distance through the bridging with Ag(+) ions of the upper and lower sides of the interlayer region.

  19. Astaxanthin ameliorates aluminum chloride-induced spatial memory impairment and neuronal oxidative stress in mice.

    Science.gov (United States)

    Al-Amin, Md Mamun; Reza, Hasan Mahmud; Saadi, Hasan Mahmud; Mahmud, Waich; Ibrahim, Abdirahman Adam; Alam, Musrura Mefta; Kabir, Nadia; Saifullah, A R M; Tropa, Sarjana Tarannum; Quddus, A H M Ruhul

    2016-04-15

    Aluminum chloride induces neurodegenerative disease in animal model. Evidence suggests that aluminum intake results in the activation of glial cells and generation of reactive oxygen species. By contrast, astaxanthin is an antioxidant having potential neuroprotective activity. In this study, we investigate the effect of astaxanthin on aluminum chloride-exposed behavioral brain function and neuronal oxidative stress (OS). Male Swiss albino mice (4 months old) were divided into 4 groups: (i) control (distilled water), (ii) aluminum chloride, (iii) astaxanthin+aluminum chloride, and (iv) astaxanthin. Two behavioral tests; radial arm maze and open field test were conducted, and OS markers were assayed from the brain and liver tissues following 42 days of treatment. Aluminum exposed group showed a significant reduction in spatial memory performance and anxiety-like behavior. Moreover, aluminum group exhibited a marked deterioration of oxidative markers; lipid peroxidation (MDA), nitric oxide (NO), glutathione (GSH) and advanced oxidation of protein products (AOPP) in the brain. To the contrary, co-administration of astaxanthin and aluminum has shown improved spatial memory, locomotor activity, and OS. These results indicate that astaxanthin improves aluminum-induced impaired memory performances presumably by the reduction of OS in the distinct brain regions. We suggest a future study to determine the underlying mechanism of astaxanthin in improving aluminum-exposed behavioral deficits.

  20. Influence of Aluminum Ions Implantation on Corrosion Behavior of Zircaloy-2 Alloy in 1 M H2SO4

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The specimens were implanted with aluminum ions with fluence ranging from 1×1016 to 1×1017 ions/cm2 to study the effect of aluminum ion implantation on the aqueous corrosion behavior of zircaloy-2 by metal vapor vacuum arc source (MEWA) at an extraction voltage of 40 kV. The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES), respectively. Transmission electron microscopy (TEM) was used to examine the microstructure of the aluminum-implanted samples. Glancing angle X-ray diffraction (GAXRD)was employed to examine the phase transformation due to the aluminum ion implantation. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted zircaloy-2 in a 1 M H2SO4 solution. It is found that a significant improvement was achieved in the aqueous corrosion resistance of zircaloy-2 implanted with aluminum ions. Finally, the mechanism of the corrosion behavior of aluminum-implanted zircaloy-2 was discussed.

  1. Protective effect of citicoline against aluminum-induced cognitive impairments in rats.

    Science.gov (United States)

    Abdel-Zaher, Ahmed O; Hamdy, Mostafa M; Abdel-Rahman, Mahran S; Abd El-Hamid, Doaa H

    2017-04-01

    The potential protective effect of citicoline on aluminum chloride-induced cognitive deficits was investigated in rats. In a Morris water maze, administration of aluminum chloride to rats for 90 days resulted in increased escape latency to reach the platform and decreased swimming speed in acquisition trials. Similarly, in probe trials, the time required to reach the hidden platform was increased and the time spent in the target quadrant was reduced. Also, administration of aluminum chloride to rats for 90 days increased the reference and working memory errors and time required to end the task in the radial arm maze. In addition, this treatment decreased the step-through latency in the passive avoidance test. Concurrently, treatment of rats with aluminum chloride for 90 days increased hippocampal glutamate, malondialdehyde, and nitrite levels and decreased intracellular reduced glutathione level. In the citicoline-treated group, aluminum chloride-induced learning and memory impairments as assessed by the Morris water maze, radial arm maze, and passive avoidance tests were inhibited. At the same time, treatment of rats with citicoline prevented the biochemical alterations induced by aluminum chloride in the hippocampus. It can be concluded that elevation of hippocampal glutamate level with consequent oxidative stress and nitric oxide (NO) overproduction may play an important role in aluminum-induced cognitive impairments. Also, our results suggest, for the first time, that citicoline can protect against the development of these cognitive deficits through inhibition of aluminum-induced elevation of glutamate level, oxidative stress, and NO overproduction in the hippocampus.

  2. Improving the Cycling Life of Aluminum and Germanium Thin Films for use as Anodic Materials in Li-Ion Batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Hudak, Nicholas [Dominican Univ., River Forest, IL (United States); Huber, Dale L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gulley, Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    The cycling of high-capacity electrode materials for lithium-ion batteries results in significant volumetric expansion and contraction, and this leads to mechanical failure of the electrodes. To increase battery performance and reliability, there is a drive towards the use of nanostructured electrode materials and nanoscale surface coatings. As a part of the Visiting Faculty Program (VFP) last summer, we examined the ability of aluminum oxide and gold film surface coatings to improve the mechanical and cycling properties of vapor-deposited aluminum films in lithium-ion batteries. Nanoscale gold coatings resulted in significantly improved cycling behavior for the thinnest aluminum films whereas aluminum oxide coatings did not improve the cycling behavior of the aluminum films. This summer we performed a similar investigation on vapor-deposited germanium, which has an even higher theoretical capacity per unit mass than aluminum. Because the mechanism of lithium-alloying is different for each electrode material, we expected the effects of coating the germanium surface with aluminum oxide or gold to differ significantly from previous observations. Indeed, we found that gold coatings gave only small or negligible improvements in cycling behavior of germanium films, but aluminum oxide (Al2O3) coatings gave significant improvements in cycling over the range of film thicknesses tested.

  3. Influence of argon and oxygen on charge-state-resolved ion energydistributions of filtered aluminum arcs

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil; Schneider, Jochen M.

    2006-03-23

    The charge-state-resolved ion energy distributions (IEDs) in filtered aluminum vacuum arc plasmas were measured and analyzed at different oxygen and argon pressures in the range 0.5 8.0 mTorr. A significant reduction of the ion energy was detected as the pressure was increased, most pronounced in an argon environment and for the higher charge states. The corresponding average charge state decreased from 1.87 to 1.0 with increasing pressure. The IEDs of all metal ions in oxygen were fitted with shifted Maxwellian distributions. The results show that it is possible to obtain a plasma composition with a narrow charge-state distribution as well as a narrow IED. These data may enable tailoring thin-film properties through selecting growth conditions that are characterized by predefined charge state and energy distributions.

  4. Retardation of surface corrosion of biodegradable magnesium-based materials by aluminum ion implantation

    Science.gov (United States)

    Wu, Guosong; Xu, Ruizhen; Feng, Kai; Wu, Shuilin; Wu, Zhengwei; Sun, Guangyong; Zheng, Gang; Li, Guangyao; Chu, Paul K.

    2012-07-01

    Aluminum ion implantation is employed to modify pure Mg as well as AZ31 and AZ91 magnesium alloys and their surface degradation behavior in simulated body fluids is studied. Polarization tests performed in conjunction with scanning electron microscopy (SEM) reveal that the surface corrosion resistance after Al ion implantation is improved appreciably. This enhancement can be attributed to the formation of a gradient surface structure with a gradual transition from an Al-rich oxide layer to Al-rich metal layer. Compared to the high Al-content magnesium alloy (AZ91), a larger reduction in the degradation rate is achieved from pure magnesium and AZ31. Our results reveal that the surface corrosion resistance of Mg alloys with no or low Al content can be improved by Al ion implantation.

  5. Optimization study of the femtosecond laser-induced forward-transfer process with thin aluminum films.

    Science.gov (United States)

    Bera, Sudipta; Sabbah, A J; Yarbrough, J M; Allen, C G; Winters, Beau; Durfee, Charles G; Squier, Jeff A

    2007-07-20

    The parameters for an effective laser-induced forward-transfer (LIFT) process of aluminum thin films using a femtosecond laser are studied. Deposited feature size as a function of laser fluence, donor film thickness, quality of focus, and the pulse duration are varied, providing a metric of the most desirable conditions for femtosecond LIFT with thin aluminum films.

  6. Hydrolysis Studies and Quantitative Determination of Aluminum Ions Using [superscript 27]Al NMR: An Undergraduate Analytical Chemistry Experiment

    Science.gov (United States)

    Curtin, Maria A.; Ingalls, Laura R.; Campbell, Andrew; James-Pederson, Magdalena

    2008-01-01

    This article describes a novel experiment focused on metal ion hydrolysis and the equilibria related to metal ions in aqueous systems. Using [superscript 27]Al NMR, the students become familiar with NMR spectroscopy as a quantitative analytical tool for the determination of aluminum by preparing a standard calibration curve using standard aluminum…

  7. Quercetin attenuates neuronal death against aluminum-induced neurodegeneration in the rat hippocampus.

    Science.gov (United States)

    Sharma, D R; Wani, W Y; Sunkaria, A; Kandimalla, R J; Sharma, R K; Verma, D; Bal, A; Gill, K D

    2016-06-02

    Aluminum is a light weight and toxic metal present ubiquitously on earth, which has gained considerable attention due to its neurotoxic effects. It also has been linked ecologically and epidemiologically to several neurological disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Guamanian-Parkinsonian complex and Amyotrophic lateral sclerosis (ALS). The mechanism of aluminum neurotoxicity is poorly understood, but it is well documented that aluminum generates reactive oxygen species (ROS). Enhanced ROS production leads to disruption of cellular antioxidant defense systems and release of cytochrome c (cyt-c) from mitochondria to cytosol resulting in apoptotic cell death. Quercetin (a natural flavonoid) protects it from oxidative damage and has been shown to decrease mitochondrial damage in various animal models of oxidative stress. We hypothesized that if oxidative damage to mitochondria does play a significant role in aluminum-induced neurodegeneration, and then quercetin should ameliorate neuronal apoptosis. Administration of quercetin (10 mg/kg body wt/day) reduced aluminum (10 mg/kg body wt/day)-induced oxidative stress (decreased ROS production, increased mitochondrial superoxide dismutase (MnSOD) activity). In addition, quercetin also prevents aluminum-induced translocation of cyt-c, and up-regulates Bcl-2, down-regulates Bax, p53, caspase-3 activation and reduces DNA fragmentation. Quercetin also obstructs aluminum-induced neurodegenerative changes in aluminum-treated rats as seen by Hematoxylin and Eosin (H&E) staining. Further electron microscopic studies revealed that quercetin attenuates aluminum-induced mitochondrial swelling, loss of cristae and chromatin condensation. These results indicate that treatment with quercetin may represent a therapeutic strategy to attenuate the neuronal death against aluminum-induced neurodegeneration.

  8. Aluminum induces tau aggregation in vitro but not in vivo.

    Science.gov (United States)

    Mizoroki, Tatsuya; Meshitsuka, Shunsuke; Maeda, Sumihiro; Murayama, Miyuki; Sahara, Naruhiko; Takashima, Akihiko

    2007-07-01

    Etiological studies suggest that aluminum (Al) intake might increase an individual's risk of developing Alzheimer's disease (AD). Biochemical analysis data on the effects of Al, however, are inconsistent. Hence, the pathological involvement of Al in AD remains unclear. If Al is involved in AD, then it is reasonable to hypothesize that Al might be involved in the formation of either amyloid plaques or neurofibrillary tangles (NFTs). Here, we investigated whether Al might be involved in NFT formation by using an in vitro tau aggregation paradigm, a tau-overexpressing neuronal cell line (N2a), and a tau-overexpressing mouse model. Although Al induced tau aggregation in a heparin-induced tau assembly assay, these aggregates were neither thioflavin T positive nor did they resemble tau fibrils seen in human AD brains. With cell lysates from stable cell lines overexpressing tau, the accumulation of SDS-insoluble tau increased when the lysates were treated with at least 100 muM Al-maltolate. Yet Al-maltolate caused illness or death in transgenic mice overexpressing human tau and in non-transgenic littermates well before the Al concentration in the brain reached 100 muM. These results indicate that Al has no direct link to AD pathology.

  9. Aqueous Rechargeable Zinc/Aluminum Ion Battery with Good Cycling Performance.

    Science.gov (United States)

    Wang, Faxing; Yu, Feng; Wang, Xiaowei; Chang, Zheng; Fu, Lijun; Zhu, Yusong; Wen, Zubiao; Wu, Yuping; Huang, Wei

    2016-04-13

    Developing rechargeable batteries with low cost is critically needed for the application in large-scale stationary energy storage systems. Here, an aqueous rechargeable zinc//aluminum ion battery is reported on the basis of zinc as the negative electrode and ultrathin graphite nanosheets as the positive electrode in an aqueous Al2(SO4)3/Zn(CHCOO)2 electrolyte. The positive electrode material was prepared through a simple electrochemically expanded method in aqueous solution. The cost for the aqueous electrolyte together with the Zn negative electrode is low, and their raw materials are abundant. The average working voltage of this aqueous rechargeable battery is 1.0 V, which is higher than those of most rechargeable Al ion batteries in an ionic liquid electrolyte. It could also be rapidly charged within 2 min while maintaining a high capacity. Moreover, its cycling behavior is also very good, with capacity retention of nearly 94% after 200 cycles.

  10. Effect on thickness of Al layer in poly-crystalline Si thin films using aluminum(Al) induced crystallization method.

    Science.gov (United States)

    Jeong, Chaehwan; Na, Hyeon Sik; Lee, Suk Ho

    2011-02-01

    The polycrystalline silicon (poly-Si) thin films were prepared by aluminum induced crystallization. Aluminum (Al) and amorphous silicon (a-Si) layers were deposited using DC sputtering and plasma enhanced chemical vapor deposition method, respectively. For the whole process Al properties of bi-layers can be one of the important factors. In this paper we investigated the structural and electrical properties of poly-crystalline Si thin films with a variation of Al thickness through simple annealing process. All samples showed the polycrystalline phase corresponding to (111), (311) and (400) orientation. Process time, defined as the time required to reach 95% of crystalline fraction, was within 60 min and Al(200 nm)/a-Si(400 nm) structure of bi-layer showed the fast response for the poly-Si films. The conditions with a variation of Al thickness were executed in preparing the continuous poly-Si films for solar cell application.

  11. Grain size effect on yield strength of titanium alloy implanted with aluminum ions

    Energy Technology Data Exchange (ETDEWEB)

    Popova, Natalya, E-mail: natalya-popova-44@mail.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); Institute of Strength Physics and Materials Science, SB RAS, 2/4, Akademicheskii Ave., 634021, Tomsk (Russian Federation); Nikonenko, Elena, E-mail: vilatomsk@mail.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30, Lenin Str., 634050, Tomsk (Russian Federation); Yurev, Ivan, E-mail: yiywork@mail.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); Kalashnikov, Mark, E-mail: kmp1980@mail.ru [Institute of Strength Physics and Materials Science, SB RAS, 2/4, Akademicheskii Ave., 634021, Tomsk (Russian Federation); Kurzina, Irina, E-mail: kurzina99@mail.ru [National Research Tomsk State University, 36, Lenin Str., 634050, Tomsk (Russian Federation)

    2016-01-15

    The paper presents a transmission electron microscopy (TEM) study of the microstructure and phase state of commercially pure titanium VT1-0 implanted by aluminum ions. This study has been carried out before and after the ion implantation for different grain size, i.e. 0.3 µm (ultra-fine grain condition), 1.5 µm (fine grain condition), and 17 µm (polycrystalline condition). This paper presents details of calculations and analysis of strength components of the yield stress. It is shown that the ion implantation results in a considerable hardening of the entire thickness of the implanted layer in the both grain types. The grain size has, however, a different effect on the yield stress. So, both before and after the ion implantation, the increase of the grain size leads to the decrease of the alloy hardening. Thus, hardening in ultra-fine and fine grain alloys increased by four times, while in polycrystalline alloy it increased by over six times.

  12. Prophylactic and therapeutic effects of taurine against aluminum-induced acute hepatotoxicity in mice.

    Science.gov (United States)

    El-Sayed, Wael M; Al-Kahtani, Mohamed A; Abdel-Moneim, Ashraf M

    2011-08-30

    Aluminum is a well known neurotoxin and a possible candidate of hepatotoxins to humans. Using natural antioxidants against metal-induced hepatotoxicity is a modern approach. In the present study, Aluminum (AlCl(3)) intoxication (a single injection of 25mg Al(3+)/kg, i.p.) for 24h in mice resulted in elevations in serum alanine aminotransferase activity and serum tumor necrosis factor and hepatic malondialdehyde levels. Aluminum reduced the activities of glutathione peroxidase, glutathione S-transferase, quinone oxidoreductase, and catalase in liver. In addition, Al caused hepatic hemorrhage, cellular degeneration as well as necrosis of hepatocytes. Ultrastructure examination showed swelling of mitochondria, derangement of rough endoplasmic reticulum cisternae and pleomorphic nuclei with abnormal chromatin distribution. Taurine, a sulfur-containing amino acid was administered to mice daily for 5 days before (at 100mg/kg, i.p.) or 2h after (a single dose of 1g/kg, i.p.) aluminum administration. Treating mice with taurine at either dosing regimens, pre- or post-aluminum administration alleviated aluminum oxidative damaging effects. The rate of recovery was better when taurine was administered prior to Al. Taurine had anaphylactic and therapeutic activity against hepatotoxicity induced by aluminum in mice.

  13. Comparison of electromagnetically induced transparency between silver, gold, and aluminum metamaterials at visible wavelengths.

    Science.gov (United States)

    Hokari, Ryohei; Kanamori, Yoshiaki; Hane, Kazuhiro

    2014-02-10

    Electromagnetically induced transparency (EIT)-like effects in silver, gold, and aluminum metamaterials consisting of dipole resonators and quadrupole resonators were demonstrated at visible wavelengths. Optical characteristics of the metamaterials could be controlled by the gap distance between the two resonators. EIT-like effects were observed at wavelengths between 603 and 789 nm, 654 and 834 nm, and 462 and 693 nm for the silver, gold, and aluminum EIT metamaterials, respectively. At wavelengths longer than around 650 nm, the silver metamaterials had better EIT-like features. At wavelengths shorter than around 650 nm, on the other hand, the aluminum metamaterials showed promising EIT-like results.

  14. Pulmonary sarcoid-like granulomatosis induced by aluminum dust: report of a case and literature review

    Institute of Scientific and Technical Information of China (English)

    CAI Hou-rong; CAO Min; MENG Fan-qing; WEI Jing-yi

    2007-01-01

    @@ Awide range of pulmonary pathology is attributed to aluminum dust exposure, including interstitial fibrosis,1-5 desquamative interstitial pneumonia,6 and pulmonary alveolar proteinosis.7 To our knowledge,granulomatous lung disease induced by aluminum dust is rare, only two cases were reported in literatures.8,9 We had the opportunity to make a diagnosis of pulmonary sarcoid-like granulomatosis in a patient exposed to aluminum dust. Herein, we report the clinical history,radiographic and histopathological findings in this patient,and the detailed mineralogical analyses performed on lung tissue obtained by open lung biopsy.

  15. Titanium conversion coatings on the aluminum foil AA 8021 used for lithium-ion battery package

    Science.gov (United States)

    Xia, Xu-Feng; Gu, Ying-Ying; Xu, Shi-Ai

    2017-10-01

    In this study, an environment-friendly titanium (Ti) conversion coating was successfully deposited on the aluminum foil AA 8021 in the solution containing hexafluorotitanic acid (H2TiF6), and its morphology, composition, growth process, hydrophilicity and corrosion resistance were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), X-ray photoelectric spectroscopy (XPS), contact-angle measurements (CAM) and salt spray exposure. The peeling strength between the Ti treated Al foil and the modified polypropylene (PP) film (PP grafted with maleic anhydride, PP-g-MAH) (Al/PP-g-MAH) was measured by T-peeling test. The results show that the Ti conversion coating is a multi-component coating composed primarily of metal oxides (TiO2 and Al2O3) and metal fluoride (AlF3). Ti treated Al foil shows better corrosion resistance than untreated and alkali-cleaned Al foils. The peeling strength of PP-g-MAH film with Ti treated Al foils is approximately 30 times higher than that with untreated Al foils. Thus, Ti treatment is a promising approach to improve the corrosion resistance and peeling strength of aluminum/polymer composite film (Al/P) used in the lithium-ion battery package.

  16. ACO-zeotype iron aluminum phosphates with variable Al/Fe ratios controlled by F⁻ ions.

    Science.gov (United States)

    Wang, Yanyan; Li, Yi; Wang, Lei; Zhang, Jingzhe; Yan, Yan; Li, Jiyang; Yu, Jihong; Wang, Jincheng; Xu, Ruren

    2011-03-01

    Three new iron aluminum phosphates |(C(2)H(10)N(2))(4)|[Fe(8 - x)Al(x)F(x)(H(2)O)(2 - x)(PO(4))(8)]·2H(2)O (χ = 1.64, 1.33, 0.80) with ACO-zeotype structures denoted as FeAPO-CJ66(a), FeAPO-CJ66(b), and FeAPO-CJ66(c), respectively, have been synthesized in the fluoride ion system. Their framework structures are made of double 4-ring (D4R) building units formed by the alternating connection of Fe(Al)O(4)F(O) trigonal bipyramids and PO(4) tetrahedra, which possess 3D intersecting 8-ring channels running along the [001], [010], and [100] directions. Fluoride ions or water molecules reside in the center of D4Rs, and diprotonated ethylenediamine cations and water molecules are occluded in the free space of channels to stabilize the whole structure. Notably, the Al/Fe ratios in the frameworks can be effectively controlled from 1/3.9 to 1/5.0 to 1/9.0 by adjusting the amounts of phosphoric acid and hydrofluoric acid added to the initial reaction mixture. Mössbauer and magnetic measurements show that the Fe ions in the compounds are bivalent and undergo antiferromagnetic ordering at room temperature.

  17. Alkaline aluminum phosphate glasses for thermal ion-exchanged optical waveguide

    Science.gov (United States)

    Wang, Fei; Chen, Baojie; Pun, Edwin Yue Bun; Lin, Hai

    2015-04-01

    Alkaline aluminum phosphate glasses (NMAP) with excellent chemical durability for thermal ion-exchanged optical waveguide have been designed and investigated. The transition temperature Tg (470 °C) is higher than the ion-exchange temperature (390 °C), which is favorable to sustain the stability of the glass structure for planar waveguide fabrication. The effective diffusion coefficient De of K+-Na+ ion exchange in NMAP glasses is 0.110 μm2/min, indicating that ion exchange can be achieved efficiently in the optical glasses. Single-mode channel waveguide has been fabricated on Er3+/Yb3+ doped NMAP glass substrate by standard micro-fabrication and K+-Na+ ion exchange. The mode field diameter is 9.6 μm in the horizontal direction and 6.0 μm in the vertical direction, respectively, indicating an excellent overlap with a standard single-mode fiber. Judd-Ofelt intensity parameter Ω2 is 5.47 × 10-20 cm2, implying a strong asymmetrical and covalent environment around Er3+ in the optical glasses. The full width at half maximum and maximum stimulated emission cross section of the 4I13/2 → 4I15/2 are 30 nm and 6.80 × 10-21 cm2, respectively, demonstrating that the phosphate glasses are potential glass candidates in developing compact optoelectronic devices. Pr3+, Tm3+ and Ho3+ doped NMAP glasses are promising candidates to fabricate waveguide amplifiers and lasers operating at special telecommunication windows.

  18. Tm3+-doped ion-exchanged aluminum germanate glass waveguide for S-band amplification

    Science.gov (United States)

    Yang, D. L.; Pun, E. Y. B.; Lin, H.

    2009-10-01

    K+-Na+ ion-exchanged channel waveguide amplifiers have been fabricated in Tm3+-doped acid-resistant aluminum germanate glasses. The optical and relative gains of a 3.15-cm-long waveguide channel were achieved to be 4.05 and 2.29 dB at 1.482 μm wavelength under 110 mW 793 nm laser excitation, respectively. After compensating the propagation loss, an internal gain of 1.50 dB and a remarkable gain coefficient of 0.48 dB/cm were obtained, which reveals a definite S-band signal amplification in the low phonon energy glass waveguide. As an expectation, UV-radiation-sensitive glass waveguide should promote the developments of gain-flatten S-band waveguide amplifiers, infrared UV-writing grating waveguide lasers, and compact multifunctional integrated optical devices.

  19. High Aluminum Tolerance of Rhodotorula sp.RS1 is Associated with Thickening of the Cell Wall Rather than Chelation of Aluminum Ions*1

    Institute of Scientific and Technical Information of China (English)

    WANG Chao; ZHAO Xue-Qiang; T.AIZAWA; M.SUNAIRI; SHEN Ren-Fang

    2013-01-01

    Aluminum (Al) is very toxic to many living organisms,including plants,animals and microorganisms.However,despite many studies on Al tolerance in plants,little has been reported concerning these mechanisms in microorganisms.In this study,a red yeast,which could tolerate Al3+ concentrations as high as 200 mmol L-1,was isolated from acidic soils,identified as Rhodotorula sp.and designated as RS1.As the medium compositions can greatly affect the responses of microorganisms to Al,two culture mediums,glucose medium (GM) and lysogeny broth medium containing soil extract (S-LBM),were used.During growth of RS1,the pH of medium decreased in GM but increased in S-LBM.These changes in the pH of the media were not induced by Al addition.No or little secretion of organic acids was observed in RS1 growth media.Importantly,the thickness of the cell walls and the ratio of cell wall to biomass of RS1 significantly increased in GM with high Al3+ concentrations.In the presence of 100 mmol Al L-1,78.0% of the total Al of whole cells was present in the thickened cell walls.The Al in cell walls was mostly bound to OH,amide and CO groups of polysaccharides.These results suggest that thickening of the cell wall in response to the high Al3+ concentrations may play an important role in the high tolerance of RS1 to Al and that pH increase of the medium and chelation of Al ions are not involved in Al tolerance of this organism.

  20. Sex-Dependent Depression-Like Behavior Induced by Respiratory Administration of Aluminum Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2015-12-01

    Full Text Available Ultrafine aluminum oxide, which are abundant in ambient and involved occupational environments, are associated with neurobehavioral alterations. However, few studies have focused on the effect of sex differences following exposure to environmental Al2O3 ultrafine particles. In the present study, male and female mice were exposed to Al2O3 nanoparticles (NPs through a respiratory route. Only the female mice showed depression-like behavior. Although no obvious pathological changes were observed in mice brain tissues, the neurotransmitter and voltage-gated ion channel related gene expression, as well as the small molecule metabolites in the cerebral cortex, were differentially modulated between male and female mice. Both mental disorder-involved gene expression levels and metabolomics analysis results strongly suggested that glutamate pathways were implicated in sex differentiation induced by Al2O3 NPs. Results demonstrated the potential mechanism of environmental ultrafine particle-induced depression-like behavior and the importance of sex dimorphism in the toxic research of environmental chemicals.

  1. Electron and ion induced electron emission from metals and insulators

    CERN Document Server

    Steinbatz, M

    2001-01-01

    gradually exposed to oxygen as an experimental probe. The experimental data are fitted with an analytical model, that is able to describe the observed kinetics. The fit parameters give absolute values of sticking probabilities and of surface reaction rates. During oxidation of aluminum and magnesium also spontaneous emission of electrons (exoelectrons) is observed. This effect is quantitatively studied for different oxygen partial pressures. The experimental data also indicate a significant influence of the surface morphology on the exoemission process. An important consequence of atomic collisions in solids is ionization leading to electron ejection from the target atoms with subsequent migration through the solid. A certain fraction of these electrons finally reaches the surface and is ejected into vacuum. A standard measurement of this phenomenon is the observation of the particle (electron, ion) induced electron emission yield g, defined as the average number of ejected electrons per incoming projectile. ...

  2. Atmospheric Ion-induced Aerosol Nucleation

    Science.gov (United States)

    Curtius, J.; Lovejoy, E. R.; Froyd, K. D.

    2006-08-01

    Ion-induced nucleation has been suggested to be a potentially important mechanism for atmospheric aerosol formation. Ions are formed in the background atmosphere by galactic cosmic rays. A possible connection between galactic cosmic rays and cloudiness has been However, the predictions of current atmospheric nucleation models are highly uncertain because the models are usually based on the liquid drop model that estimates cluster thermodynamics based on bulk properties (e.g., liquid drop density and surface tension). Sulfuric acid (H2SO4) and water are assumed to be the most important nucleating agents in the free troposphere. Measurements of the molecular thermodynamics for the growth and evaporation of cluster ions containing H2SO4 and H2O were performed using a temperature-controlled laminar flow reactor coupled to a linear quadrupole mass spectrometer as well as a temperature-controlled ion trap mass spectrometer. The measurements were complemented by quantum chemical calculations of the cluster ion structures. The analysis yielded a complete set of H2SO4 and H2O binding thermodynamics extending from molecular cluster ions to the bulk, based on experimental thermodynamics for the small clusters. The data were incorporated into a kinetic aerosol model to yield quantitative predictions of the rate of ion-induced nucleation for atmospheric conditions. The model predicts that the negative ion-H2SO4-H2O nucleation mechanism is an efficient source of new particles in the middle and upper troposphere.

  3. Neuronal gene expression in aluminum-induced neurofibrillary pathology: an in situ hybridization study.

    Science.gov (United States)

    Chambers, C B; Muma, N A

    1997-01-01

    Alterations in cytoskeletal proteins such as the perikaryal accumulation of neurofilaments (NFs) occur in a number of human neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis and may contribute to their debilitating effects. The administration of aluminum salts to rabbits induces the aberrant accumulation of NFs within the proximal axons and perikarya of vulnerable neurons and is one animal model which has been extensively studied in an attempt to gain insight into the mechanism(s) of NF perturbations in human disease. Previous studies using Northern blotting techniques to examine mRNA levels in the aluminum-induced neuropathy model have led to seemingly contradictory results. We have used in situ hybridization which provides the cellular resolution needed to: 1) determine whether there are generalized decreases in the levels of mRNA expression or decreases in mRNA encoding specific proteins; 2) determine whether alterations in mRNA levels occur specifically in neurons with NF accumulations; and 3) begin to resolve some of the apparent contradictions in the literature. A moderate dose of aluminum lactate administered on two consecutive days produced neurofibrillary tangles in spinal cord neurons seven days after the first dose. Polyadenylated mRNA levels were not altered in spinal cord neurons in aluminum-treated compared to saline-treated control animals or in tangle-bearing compared to non tangle-bearing neurons in aluminum-treated animals. Middle and high NF subunit (NFH) mRNA levels were not significantly different from polyadenylated mRNA levels in spinal cord neurons in aluminum-treated/control animals. NFH mRNA levels were decreased in neurons containing aluminum-induced NF accumulations. These results suggest that NFH gene expression may be down regulated by an inhibitory feedback mechanism induced by perikaryal accumulations of NFs. This inhibitory feedback regulation for NFH may have

  4. High temperature reactive ion etching of iridium thin films with aluminum mask in CF4/O2/Ar plasma

    Directory of Open Access Journals (Sweden)

    Chia-Pin Yeh

    2016-08-01

    Full Text Available Reactive ion etching (RIE technology for iridium with CF4/O2/Ar gas mixtures and aluminum mask at high temperatures up to 350 °C was developed. The influence of various process parameters such as gas mixing ratio and substrate temperature on the etch rate was studied in order to find optimal process conditions. The surface of the samples after etching was found to be clean under SEM inspection. It was also shown that the etch rate of iridium could be enhanced at higher process temperature and, at the same time, very high etching selectivity between aluminum etching mask and iridium could be achieved.

  5. Do toxic ions induce hormesis in plants?

    Science.gov (United States)

    Poschenrieder, Charlotte; Cabot, Catalina; Martos, Soledad; Gallego, Berta; Barceló, Juan

    2013-11-01

    The concept of hormesis in plants is critically reviewed, taking growth stimulation by low concentrations of toxic trace elements as a reference. The importance of both non-adaptive and adaptive mechanisms underlying ion-induced hormetic growth responses is highlighted. The activation of defense mechanisms by metal ions and pathogenic elicitors and the cross talk between the signals induced by metal ions and biotic stressors are considered. The production of reactive oxygen species and, consequently, the induction of stress-induced antioxidants, are key mechanisms in metal ion-induced hormesis in plants. It is concluded that in the current scientific literature, hormesis is used as an "umbrella" term that includes a wide range of different mechanisms. It is recommended that the term hormesis be used in plant toxicology as a descriptive term for the stimulated phase in growth response curves that is induced by low concentrations of toxic metal ions without evidence of the underlying mechanisms. If the mechanisms underlying the stimulated growth phase have been identified, specific terms, such as amelioration, defense gene activation, priming or acclimation, should be used. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Ion irradiation induced direct damage to DNA

    CERN Document Server

    Wang, Wei; Su, Wenhui

    2008-01-01

    Ion beams have been widely applied in a few biological research fields such as radioactive breeding, health protection, and tumor therapy. Up to now many interesting and impressive achievements in biology and agriculture have been made. Over the past several decades, scientists in biology, physics, and chemistry have pursued investigations focused on understanding the mechanisms of these radiobiological effects of ion beams. From the chemical point of view, these effects are due to the ion irradiation induced biomolecular damage, direct or indirect. In this review, we will present a chemical overview of the direct effects of ion irradiation upon DNA and its components, based on a review of literature combined with recent experimental results. It is suggested that, under ion bombardment, a DNA molecule undergoes a variety of processes, including radical formation, atomic displacement, intramolecular bond-scissions, emission of fragments, fragment recombination and molecular crosslink, which may lead to genetic...

  7. Heavy ion induced mutation in arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Tano, Shigemitsu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Heavy ions, He, C, Ar and Ne were irradiated to the seeds of Arabidopsis thaliana for inducing the new mutants. In the irradiated generation (M{sub 1}), germination and survival rate were observed to estimate the relative biological effectiveness in relation to the LET including the inactivation cross section. Mutation frequencies were compared by using three kinds of genetic loci after irradiation with C ions and electrons. Several interesting new mutants were selected in the selfed progenies of heavy ion irradiated seeds. (author)

  8. Formation of aluminum films on silicon by ion beam deposition: A comparison with ionized cluster beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zuhr, R.A.; Haynes, T.E.; Galloway, M.D. (Oak Ridge National Lab., TN (USA)); Tanaka, S.; Yamada, A.; Yamada, I. (Kyoto Univ. (Japan). Ion Beam Engineering Lab.)

    1990-01-01

    The direct ion beam deposition (IBD) technique has been used to study the formation of oriented aluminum films on single crystal silicon substrates. In the IBD process, thin film growth is accomplished by decelerating a magnetically-analyzed ion beam to low energies (10--200 eV) for direct deposition onto the substrate under UHV conditions. The energy of the incident ions can be selected to provide the desired growth conditions, and the mass analysis ensures good beam purity. The aluminum on silicon system is one which has been studied extensively by ionized cluster beam (ICB) deposition. In this work, we have studied the formation of such films by IBD with emphasis on the effects of ion energy, substrate temperature, and surface cleanliness. Oriented films have been grown on Si(111) at temperatures from 40{degree} to 300{degree}C and with ion energies from 30 to 120 eV per ion. Completed films were analyzed by ion scattering, x-ray diffraction, scanning electron microscopy, and optical microscopy. Results achieved for thin films grown by IBD are compared with results for similar films grown by ICB deposition. 15 refs., 3 figs.

  9. Focused helium-ion-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Alkemade, P.F.A.; Miro, H. [Delft University of Technology, Kavli Institute of Nanoscience, Delft (Netherlands)

    2014-12-15

    The recent introduction of the helium ion microscope (HIM) offers new possibilities for materials modification and fabrication with spatial resolution below 10 nm. In particular, the specific interaction of He{sup +} ions in the tens of keV energy range with materials - i.e., minimal deflection and mainly energy loss via electronic excitations - renders the HIM a special tool for ion-beam-induced deposition. In this work, an overview is given of all studies of helium-ion-beam-induced deposition (He-IBID) that appeared in the literature before summer 2014. Continuum models that describe the deposition processes are presented in detail, with emphasis on precursor depletion and replenishment. In addition, a Monte Carlo model is discussed. Basic experimental He-IBID studies are critically examined. They show deposition rates of up to 0.1 nm{sup 3}/ion. Analysis by means of a continuum model yields the precursor diffusion constant and the cross sections for beam-induced precursor decomposition and beam-induced desorption. Moreover, it is shown that deposition takes place only in a small zone around the beam impact point. Furthermore, the characterization of deposited materials is discussed in terms of microstructure and resistivity. It is shown that He-IBID material resembles more electron-beam-induced-deposition (EBID) material than Ga-ion-beam-induced-deposition (Ga-IBID) material. Nevertheless, the spatial resolution for He-IBID is in general better than for EBID and Ga-IBID; in particular, proximity effects are minimal. (orig.)

  10. Classification of wrought aluminum alloys by Artificial Neural Networks evaluation of Laser Induced Breakdown Spectroscopy spectra from aluminum scrap samples

    Science.gov (United States)

    Campanella, B.; Grifoni, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Sorrentino, F.; Palleschi, V.

    2017-08-01

    Every year throughout the world > 50 million vehicles reach the end of their life, producing millions of tons of automotive waste. The current strategies for the separation of the non-ferrous waste fraction, contain mainly aluminum, magnesium, zinc and copper alloys, involve high investment and operational costs, and pose environmental concerns. The European project SHREDDERSORT, in which our research group was actively involved, aimed to overcome this issue by developing a new dry sorting technology for the shredding of non-ferrous automotive wastes. This work represents one step of the complex SHREDDERSORT project, dedicated to the development of a strategy based on Laser Induced Breakdown Spectroscopy (LIBS) for the sorting of light alloys. LIBS was here applied in laboratory for the analysis of stationary aluminum shredder samples. To process the LIBS spectra a methodological approach based on artificial neural networks was used. Although separation could in principle be based on simple emission line ratios, the neural networks approach enables more reproducible results, which can accommodate the unavoidable signal variations due to the low intrinsic reproducibility of the LIBS systems. The neural network separated samples into different clusters and estimates their elemental concentrations.

  11. Surface modifications induced by high fluxes of low energy helium ions.

    Science.gov (United States)

    Tanyeli, İrem; Marot, Laurent; Mathys, Daniel; van de Sanden, Mauritius C M; De Temmerman, Gregory

    2015-04-28

    Several metal surfaces, such as titanium, aluminum and copper, were exposed to high fluxes (in the range of 10(23) m(-2) s(-1)) of low energy (pillars, are observed on these metals. The differences and similarities in the development of surface morphologies are discussed in terms of the material properties and compared with the results of similar experimental studies. The results show that He ions induced void growth and physical sputtering play a significant role in surface modification using high fluxes of low energy He ions.

  12. Effects of aluminum on growth, polyamine metabolism, and inorganic ions in suspension cultures of red spruce (Picea rubens)

    Science.gov (United States)

    Rakesh Minocha; Walter C. Shortle; Daniel J. Jr. Coughin; Subhash C. Minocha

    1996-01-01

    The influence of age of red spruce (Picea rubens Sarg.) cell suspensions on aluminum (Al) effects was studied by adding AICI3 (0.2, 0.5, and 1.0 mM) to the media on each day of a 7-day culture period and analyzing for changes in total cell mass, polyamines, arginine decarboxylase activity, and inorganic ions after 24 h of...

  13. Aluminum induced crystallization of strongly (111) oriented polycrystalline silicon thin film and nucleation analysis

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A polycrystalline silicon thin film was fabricated on glass substrate by means of aluminum induced crystallization (AIC). Al and α-Si layers were deposited by magnetron sputtering respectively and annealed at 480°C for 1 h to realize layer exchange. The polycrystalline silicon thin film was continuous and strongly (111) oriented. By analyzing the structure variation of the oxidation membrane and lattice mismatch between γ-Al2O3 and Si, it was concluded that aluminum promoted the formation of (111) oriented silicon nucleus by controlling the orientation of γ-Al2O3, which was formed at the early stage of annealing.

  14. Ion irradiation induced effects in polyamidoimide

    Energy Technology Data Exchange (ETDEWEB)

    Merhari, L.; Belorgeot, C.; Moliton, J.P. (Laboratoire d' Electronique des Polymeres sous Faisceaux Ioniques 123, avenue Albert Thomas, 87060 Limoges Cedex (France))

    1991-09-01

    The interaction between ion beam and polyamidoimide (PAI) is studied by means of low-temperature infrared spectroscopy. 200 keV Ar{sup +} and 250 keV He{sup +} beams with fluences ranging from 10{sup 13} ions cm{sup {minus}2} to 5{times}10{sup 16} ions cm{sup {minus}2} are found to induce atomic bond breaks leading to absorption bands at 2344, 2261, and 2125 cm{sup {minus}1} corresponding respectively to CO{sub 2}, C=N=N and C=N--R vibrations. Shrinkage of the polymer along with a drastic decrease of the resistivity during Ar{sup +} and He{sup +} irradiation are observed. Speculations on the respective role of electronic processes and atomic collisions in the evolution of the polymer are made. No evidence of PAI modification through knock-on mechanism for fluences lower than 5{times}10{sup 15} ions cm{sup {minus}2} is noticed. In fact, our results would suggest a predominant role of the electronic processes for the low fluences (up to 5{times}10{sup 15} ions cm{sup {minus}2} ), whereas a degradation mechanism based on atomic collisions is more likely to take place for higher fluences. A theoretical mechanism of reactions based upon our Fourier transform infrared (FTIR) and secondary ion mass spectroscopies (SIMS) results, describing the chemical changes occurring in the PAI, is presented and briefly discussed.

  15. Microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system.

    Science.gov (United States)

    Yang, S S; Lin, J Y; Lin, Y T

    1998-09-01

    To investigate the microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system, aluminum alloys A356, AA 5052, AA 5083 and AA 6061 were chosen as the test alloys and Cladosporium and several fuel-oil contaminated microbes isolated in Taiwan were used as test organisms. Aluminum alloy AA 5083 in fuel-oil/aqueous system was the most susceptible material for microbial corrosion, then followed by aluminum alloys AA 5052 and A356, and AA 6061 was more resistant to microbial aggression. Mixed culture had high capability of corrosion, then followed by Penicillium sp. AM-F5, Fusarium sp. AM-F1, Pseudomonas aeruginosa AM-B5, Ps. fluorescens AM-B9, C. resinae ATCC 22712, Penicillium sp. AM-F2, Candida sp. AM-Y1 and Ps. aeruginosa AM-B11. From energy dispersive spectrometer analysis, aluminum and magnesium contents decreased in the corrosion area, while chlorine and sulfur contents increased. The major organic acid produced in fuel-oil/aqueous system was acetic acid, and the total organic acids content had a positive correlation with the degree of microbial corrosion.

  16. High energy density aluminum battery

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  17. High energy density aluminum battery

    Science.gov (United States)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  18. Anti-oxidative effect of resveratrol on aluminum induced toxicity in rat cerebral tissue.

    Science.gov (United States)

    Zakaria, M M H; Hajipour, B; Estakhri, R; Saleh, B M

    2017-01-01

    The direct protective effects of resveratrol against oxidative stress have been demonstrated in neuroglial cells, the mechanisms of these effects are not fully understood. The aim of this research was to study the effect of resveratrol on AL induced cerebral injury in rat. We divided the groups as follows with 10 animals each: a) Group I - served as control receiving normal drinking water and diet ad libitum. b) Group II - animals were administered aluminum at a dose level of 100 mg/kg body weight for a period of 6 weeks daily through oral gavage. c) Group III - animals were administered aluminum at a dose level of 100 mg/kg body weight and resveratrol at a dose of 10 mg/kg body weight intraperitoneally for a period of 6 weeks daily. After 6 weeks rats were anesthetized and decapitated. Brains were removed immediately and frozen in liquid nitrogenRESULTS: The levels of SOD and GPx antioxidant enzymes were decreased in all of the groups receiving aluminium, but it was less severe in resveratrol treated group. SOD and GPx levels in aluminium + resveratrol group were higher than in the aluminum group (p resveratrol group compared to aluminum group and the difference was significant (p resveratrol is effective in preventing AL induced toxicity by reducing MDA production in cerebral tissue. Resveratrol also attenuated SOD and GPx suppression in cerebral tissue significantly. Our findings provide the rationale for further studies directed to understanding the mechanism of resveratrol in preventing neurodeterioration (Tab. 1, Ref. 35).

  19. Ion induced deformation of soft tissue.

    Science.gov (United States)

    Myers, T G; Aldis, G K; Naili, S

    1995-01-01

    In this paper the effects of changing the ion concentration in and around a sample of soft tissue are investigated. The triphasic theory developed by Lai et al. (1990, Biomechanics of Diarthrodial Joints, Vol. 1, Berlin, Springer-Verlag) is reduced to two coupled partial differential equations involving fluid ion concentration and tissue solid deformation. These equations are given in general form for Cartesian, cylindrical and spherical geometries. After solving the two equations quantities such as fluid velocity, fluid pressure, chemical potentials and chemical expansion stress may be easily calculated. In the Cartesian geometry comparison is made with the experimental and theoretical work of Myers et al. (1984, ASME J. biomech. Engng, 106, 151-158). This dealt with changing the ion concentration of a salt shower on a strip of bovine articular cartilage. Results were obtained in both free swelling and isometric tension states, using an empirical formula to account for ion induced deformation. The present theory predicts lower ion concentrations inside the tissue than this earlier work. A spherical sample of tissue subjected to a change in salt bath ion concentration is also considered. Numerical results are obtained for both hypertonic and hypotonic bathing solutions. Of particular interest is the finding that tissue may contract internally before reaching a final swollen equilibrium state or swell internally before finally contracting. By considering the relative magnitude, and also variation throughout the time course of terms in the governing equations, an even simpler system is deduced. As well as being linear the concentration equation in the new system is uncoupled. Results obtained from the linear system compare well with those from the spherical section. Thus, biological swelling situations may be modelled by a simple system of equations with the possibility of approximate analytic solutions in certain cases.

  20. Effect of the ion-beam bombardment and annealing temperature on sol-gel derived yttrium aluminum oxide film as liquid crystal alignment layer

    Science.gov (United States)

    Jeong, Hae-Chang; Heo, Gi-Seok; Kim, Eun-Mi; Lee, Ju Hwan; Han, Jeong-Min; Seo, Dae-Shik

    2017-02-01

    We demonstrated a homogeneous liquid-crystal (LC) alignment state on yttrium aluminum oxide (YAlO) films, where the alignment was induced by ion-beam (IB) irradiation. Topographical analysis was performed by atomic force microscopy as a function of annealing temperature. Higher annealing temperatures yielded a smoother surface, accompanied by reduced light scattering. Transparency in the visible region increased on the surface fabricated at higher annealing temperatures. LC alignment mechanism was determined by X-ray diffraction (XRD) analysis. Moreover, IB-irradiated YAlO films annealed at temperatures greater than 200 °C exhibited good thermal stability and low capacitance-voltage hysteresis. The IB-irradiated YAlO films are suitable as alternative alignment layers in advanced LC display applications.

  1. Unexpected temporal evolution of atomic spectral lines of aluminum in a laser induced breakdown spectroscopy experiment

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Rawad, E-mail: rawad.saad@cea.fr [CEA, DEN, DPC, SEARS, LANIE, 91191 Gif-sur-Yvette (France); L' Hermite, Daniel, E-mail: daniel.lhermite@cea.fr [CEA, DEN, DPC, SEARS, LANIE, 91191 Gif-sur-Yvette (France); Bousquet, Bruno, E-mail: bruno.bousquet@u-bordeaux1.fr [LOMA, Université de Bordeaux, CNRS, 351 Cours de la Libération, 33405 Talence Cedex (France)

    2014-11-01

    The temporal evolution of the laser induced breakdown (LIBS) signal of a pure aluminum sample was studied under nitrogen and air atmospheres. In addition to the usual decrease of signal due to plasma cooling, unexpected temporal evolutions were observed for a spectral lines of aluminum, which revealed the existence of collisional energy transfer effects. Furthermore, molecular bands of AlN and AlO were observed in the LIBS spectra, indicating recombination of aluminum with the ambient gas. Within the experimental conditions reported in this study, both collisional energy transfer and recombination processes occurred around 1.5 μs after the laser shot. This highlights the possible influence of collisional and chemical effects inside the plasma that can play a role on LIBS signals. - Highlights: • Persistence of two Al I lines related to the 61,844 cm{sup −1} energy level only under nitrogen atmosphere. • Collisional energy transfer effect exists between aluminum and nitrogen. • Observation of molecular band of AlN (under nitrogen) and AlO (under air) after a delay time of 1.5 µs. • 20% of oxygen in air is sufficient to annihilate both the collisional energy transfer effect and the AlN molecular formation.

  2. Stability of fluorinated parylenes to oxygen reactive-ion etching under aluminum, aluminum oxide, and tantalum nitride overlayers

    Science.gov (United States)

    Senkevich, Jay J.; Wang, B.; Fortin, J. B.; Nielsen, M. C.; McDonald, J. F.; Lu, T.-M.; Nuesca, G. M.; Peterson, G. G.; Selbrede, S. C.; Weise, M. T.

    2003-09-01

    The fluorine stability of two parylenes, aliphatic-fluorinated AF-4 (α, α, α', α' poly(p-tetrafluoroxylylene) and aromatic-fluorinated VT-4 (2, 3, 5, 6 poly(p-tetrafluoroxylylene), were investigated underneath Al, Al2O3, and TaNX overlayers with and without exposure to oxygen reactive-ion etching (RIE). No fluorine diffusion was observed for Al films deposited onto the as-received parylenes. However, after oxygen RIE, x-ray photoelectron spectroscopy (XPS) depth profiling detected fluorine diffusion throughout Al and to a lesser extent Al2O3 but in contrast to Ta2.67N. Metal-fluoride bonding was evident at the metal/parylene interface for all the overlayers after the parylene was exposed to oxygen RIE and annealed.

  3. Heavy-Ion-Induced Electronic Desorption of Gas from Metals

    CERN Document Server

    Molvik, A W; Mahner, E; Kireeff Covo, M; Bellachioma, M C; Bender, M; Bieniosek, F M; Hedlund, E; Krämer, A; Kwan, J; Malyshev, O B; Prost, L; Seidl, P A; Westenskow, G; Westerberg, L

    2007-01-01

    During heavy-ion operation in several particle accelerators worldwide, dynamic pressure rises of orders of magnitude were triggered by lost beam ions that bombarded the vacuum chamber walls. This ion-induced molecular desorption, observed at CERN, GSI, and BNL, can seriously limit the ion beam lifetime and intensity of the accelerator. From dedicated test stand experiments we have discovered that heavy-ion-induced gas desorption scales with the electronic energy loss (dEe/dx) of the ions slowing down in matter; but it varies only little with the ion impact angle, unlike electronic sputtering.

  4. Heavy-ion induced electronic desorption of gas from metals

    Energy Technology Data Exchange (ETDEWEB)

    Molvik, A W; Kollmus, H; Mahner, E; Covo, M K; Bellachioma, M C; Bender, M; Bieniosek, F M; Hedlund, E; Kramer, A; Kwan, J; Malyshev, O B; Prost, L; Seidl, P A; Westenskow, G; Westerberg, L

    2006-12-19

    During heavy ion operation in several particle accelerators world-wide, dynamic pressure rises of orders of magnitude were triggered by lost beam ions that bombarded the vacuum chamber walls. This ion-induced molecular desorption, observed at CERN, GSI, and BNL, can seriously limit the ion beam lifetime and intensity of the accelerator. From dedicated test stand experiments we have discovered that heavy-ion induced gas desorption scales with the electronic energy loss (dE{sub e}/d/dx) of the ions slowing down in matter; but it varies only little with the ion impact angle, unlike electronic sputtering.

  5. K+-Na+ ion-exchanged sodium magnesium aluminum germanate glass waveguide amplifier operating in the first telecommunications window

    Science.gov (United States)

    Yang, Dianlai; Zhang, Jie; Pun, Edwin Yue-Bun; Lin, Hai

    2010-12-01

    Potassium-sodium (K+-Na+) ion-exchanged multimode channel waveguide amplifiers have been fabricated based on Tm3+/Yb3+ codoped sodium magnesium aluminum germanate (NMAG) glass substrates. The normalized optical and relative gain coefficients of a 2.20 cm long device were identified to be 3.65 dB/cm and 1.58 dB/cm, respectively, at a signal wavelength of 810 nm under 457 mW 980 nm laser diode excitation. These are the highest values reported, and the results indicate that Tm3+/Yb3+ codoped NMAG glasses are an attractive material for optical amplification in the first telecommunications window.

  6. Asparagus cochinchinensis Extract Alleviates Metal Ion-Induced Gut Injury in Drosophila: An In Silico Analysis of Potential Active Constituents

    Directory of Open Access Journals (Sweden)

    Weiyu Zhang

    2016-01-01

    Full Text Available Metal ions and sulfate are components of atmospheric pollutants that have diverse ways of entering the human body. We used Drosophila as a model to investigate the effect of Asparagus cochinchinensis (A. cochinchinensis extracts on the gut and characterized gut homeostasis following the ingestion of metal ions (copper, zinc, and aluminum. In this study, we found that the aqueous A. cochinchinensis extract increased the survival rate, decreased epithelial cell death, and attenuated metal ion-induced gut morphological changes in flies following chronic exposure to metal ions. In addition, we screened out, by network pharmacology, six natural products (NPs that could serve as putative active components of A. cochinchinensis that prevented gut injury. Altogether, the results of our study provide evidence that A. cochinchinensis might be an effective phytomedicine for the treatment of metal ion-induced gut injury.

  7. ASR prevention — Effect of aluminum and lithium ions on the reaction products

    Energy Technology Data Exchange (ETDEWEB)

    Leemann, Andreas, E-mail: andreas.leemann@empa.ch [Laboratory for Concrete/Construction Chemistry, Empa, Swiss Federal Laboratories for Material Science and Technology, Überlandstr. 129, 8600 Dübendorf (Switzerland); Bernard, Laetitia [Laboratory for Nanoscale Materials Science, Empa, Swiss Federal Laboratories for Material Science and Technology, Überlandstr. 129, 8600 Dübendorf (Switzerland); Alahrache, Salaheddine; Winnefeld, Frank [Laboratory for Concrete/Construction Chemistry, Empa, Swiss Federal Laboratories for Material Science and Technology, Überlandstr. 129, 8600 Dübendorf (Switzerland)

    2015-10-15

    In spite of the recent progress in the understanding of the mechanisms enabling aluminum-containing SCM like metakaolin and added LiNO{sub 3} to limit the extent of ASR in mortar and concrete, some gaps still remain. They concern mainly the effect of aluminum-containing SCM on the formed ASR products and the influence of aggregate characteristics on the effectiveness of LiNO{sub 3}. In this study, a model system, concrete and mortar were investigated by pore solution analysis, TGA, XRD, NMR, SEM combined with EDX and ToF-SIMS to address these questions. The amount of aluminum present in the pore solution of concrete and mortar is only able to slow down SiO{sub 2} dissolution but not to alter morphology, structure and composition of the reaction products. LiNO{sub 3} can suppress ASR by forming dense products protecting reactive minerals from further reaction. But its effectiveness is decreasing with increasing specific surface area of the reactive minerals in aggregates. - Highlights: • Aluminum of SCM slows down SiO{sub 2} dissolution. • Aluminum of SCM does not alter morphology and structure of ASR product. • ASR suppressing effect of LiNO{sub 3} depends on specific surface area of the aggregates.

  8. Collective effects in deuteron induced reactions of aluminum

    Science.gov (United States)

    Canbula, Bora

    2017-01-01

    Cross sections of 27 Al (d,x)22 Na , 27 Al (d,x)24 Na , and 27 Al (d,x)27 Mg reactions are calculated by using TALYS 1.6 computer code with different nuclear level density models, which are composite Gilbert-Cameron model, back-shifted Fermi gas model, generalized superfluid model, and recently proposed collective semi-classical Fermi gas model in the energy range of 3-180 MeV. The results are compared with the experimental data taken from EXFOR library. In these deuteron induced reactions, collective effects are investigated by means of nuclear level density models. Collective semi-classical Fermi gas model including the collective effects via the level density parameter represents the best agreement with the experimental data compared to the other level density models, especially in the low deuteron bombarding energies where the collective effects dominate.

  9. Ion beam induced stress formation and relaxation in germanium

    Energy Technology Data Exchange (ETDEWEB)

    Steinbach, T., E-mail: Tobias.Steinbach@uni-jena.de [Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, D-07743 Jena (Germany); Reupert, A.; Schmidt, E.; Wesch, W. [Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, D-07743 Jena (Germany)

    2013-07-15

    Ion irradiation of crystalline solids leads not only to defect formation and amorphization but also to mechanical stress. In the past, many investigations in various materials were performed focusing on the ion beam induced damage formation but only several experiments were done to investigate the ion beam induced stress evolution. Especially in microelectronic devices, mechanical stress leads to several unwanted effects like cracking and peeling of surface layers as well as changing physical properties and anomalous diffusion of dopants. To study the stress formation and relaxation process in semiconductors, crystalline and amorphous germanium samples were irradiated with 3 MeV iodine ions at different ion fluence rates. The irradiation induced stress evolution was measured in situ with a laser reflection technique as a function of ion fluence, whereas the damage formation was investigated by means of Rutherford backscattering spectrometry. The investigations show that mechanical stress builds up at low ion fluences as a direct consequence of ion beam induced point defect formation. However, further ion irradiation causes a stress relaxation which is attributed to the accumulation of point defects and therefore the creation of amorphous regions. A constant stress state is reached at high ion fluences if a homogeneous amorphous surface layer was formed and no further ion beam induced phase transition took place. Based on the results, we can conclude that the ion beam induced stress evolution seems to be mainly dominated by the creation and accumulation of irradiation induced structural modification.

  10. Role of Chloride Ion and Dissolved Oxygen in Electrochemical Corrosion of AA5083-H321 Aluminum-Magnesium Alloy in NaCl Solutions under Flow Conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Flow-induced corrosion consists electrochemical and mechanical components. The present paper has to assessed the role of chloride ion and dissolved oxygen in the electrochemical component of flow induced corrosion for AA5083-H321 aluminum-magnesium alloy which is extensively used in the construction of high-speed boats, submarines, hovercrafts, and desalination systems, in NaCl solutions. Electrochemical tests were carried out at flow velocities of 0, 2, 5, 7 and 10 m/s, in aerated and deaerated NaCl solutions with different sodium chloride concentrations. The results showed that the high rate of oxygen reduction under hydrodynamic conditions causes an increase in the density of pits on the surface. The increase of chloride ions concentration under flow conditions accelerates the rate of anodic reactions, but have no influence on the cathodic reactions. Thus, in the current work, it was found that under flow conditions, due to the elimination of corrosion products inside the pits, corrosion resistance of the alloy is increased.

  11. Cytotoxicity of glass ionomer cement on human exfoliated deciduous teeth stem cells correlates with released fluoride, strontium and aluminum ion concentrations

    Directory of Open Access Journals (Sweden)

    Kanjevac Tatjana V.

    2015-01-01

    Full Text Available Stem cells from human exfoliated deciduous teeth (SHED can be used as a cell-based therapy in regenerative medicine and in immunomodulation. Pulp from human deciduous teeth can be stored as a source of SHED. Glass ionomer cements (GICs are commonly used in restorative dentistry and in cavity lining. GICs have lower biocompatibility and are cytotoxic for dental pulp cells. In this study, seven commonly used GICs were tested for their cytotoxic effects on SHED, for their potential to arrest mitosis in cells and induce chromosome aberrations, and were compared with the effects of composite. Fuji II, Fuji VIII, Fuji IX, Fuji plus and Vitrebond had significantly higher cytotoxic effects on SHED than composite. Only SHEDs that have been treated with Fuji I, Fuji IX, Fuji plus and composite recovered the potential for proliferation, but no chromosome aberrations were found after treatment with GICs. The cytotoxic effects of GICs on SHEDs were in strong correlation with combined concentrations of released fluoride, aluminum and strontium ions. Fuji I exhibited the lowest activity towards SHEDs; it did not interrupt mitosis and did not induce chromosome aberrations, and was accompanied by the lowest levels of released F, Al and Sr ions. Projekat Ministarstva nauke Republike Srbije, br. ON175069, br. ON175071 i br. ON175103

  12. Quantitative analysis of impurities in aluminum alloys by laser-induced breakdown spectroscopy without internal calibration

    Institute of Scientific and Technical Information of China (English)

    LI Hong-kun; LIU Ming; CHEN Zhi-jiang; LI Run-hua

    2008-01-01

    To develop a fast and sensitive alloy elemental analysis method, a laser-induced breakdown spectroscopy(LIBS) system was established and used to carry out quantitative analysis of impurities in aluminum alloys in air at atmospheric pressure. A digital storage oscilloscope was used as signal recording instrument, instead of traditional gate integrator or Boxcar averager, to reduce the cost of the whole system. Linear calibration curves in the concentration range of 4×10-5-10-2 are built for Mg, Cr, Mn, Cu and Zn using absolute line intensity without internal calibrations. Limits of detection for these five elements in aluminum alloy are determined to be (2-90)×10-6. It is demonstrated that LIBS can provide quantitative trace elemental analysis in alloys even without internal calibration. This approach is easy to use in metallurgy industries and relative research fields.

  13. Analysis of time phase of characteristic rad iation in plasma induced by laser ablating aluminum

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With time- and space-resolved technique, we have recorde d time-resolved spectra of irradiation of the plasma induced by Nd: YAG laser a blating metal Aluminum in Ar, in which, laser pulse-energy was set up to 145 mJ /pulse and the buffer pressure 100 kpa. The continuum radiation and special emis sion of Aluminum plasma were studied based on the records. According to time dis tribution of Al Ⅰ396.15 nm emission, we analyzed the time differences between c haracteristic and continuum radiation evolving. We tried to explain the time pha ses of characteristic radiation evolving with traditional theoretical model of a tomic transition. As the result, we found that it was difficult to explain our e xperimental results with the model. In order to explain our experimental results , we need new model or to improve the traditional theoretical model of atomic tr ansition.

  14. Ginkgo biloba extract alleviates oxidative stress and some neurotransmitters changes induced by aluminum chloride in rats.

    Science.gov (United States)

    Mohamed, Naglaa El-Shahat; Abd El-Moneim, Ahmed E

    2017-03-01

    In the present study, twenty four adult male albino rats were classified into four groups. The control group received normal diet and water; the second group was treated daily with oral dose of Ginkgo biloba (200 mg/kg body weight [b.wt]) for 3 mo; the third group was treated daily with oral dose of aluminum chloride (10 mg/kg b.wt) for 3 mo; and the fourth group was treated with both Ginkgo biloba and aluminum chloride (200 and 10 mg/kg b.wt, respectively) using a stomach tube for 3 mo. The results showed that administration of AlCl3 to rats induced significant increase (P Ginkgo biloba group. It could be concluded that the protective effect of Ginkgo biloba may be attributed to its antioxidant properties.

  15. Laser induced forward transfer aluminum layers: Process investigation by time resolved imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mattle, Thomas [General Energies Research Department, Paul Scherrer Institut, CH-5232 Villigen-PSI (Switzerland); Shaw-Stewart, James [General Energies Research Department, Paul Scherrer Institut, CH-5232 Villigen-PSI (Switzerland); Laboratory for Functional Polymers, Empa Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Schneider, Christof W. [General Energies Research Department, Paul Scherrer Institut, CH-5232 Villigen-PSI (Switzerland); Lippert, Thomas, E-mail: thomas.lippert@psi.ch [General Energies Research Department, Paul Scherrer Institut, CH-5232 Villigen-PSI (Switzerland); Wokaun, Alexander [General Energies Research Department, Paul Scherrer Institut, CH-5232 Villigen-PSI (Switzerland)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Side- and front-on shadowgraphy. Black-Right-Pointing-Pointer Aluminum flyer is ejected intact for all tested energies. Black-Right-Pointing-Pointer Indications of bending of the aluminum flyer are shown. - Abstract: Laser induced forward transfer of an aluminum thin film on a triazene polymer as a sacrificial layer has been studied with time resolved imaging. Both side- and front-on imaging of the process give a more detailed understanding of the stability of the ejected material during flight. For high fluence ablation (800 mJ/cm{sup 2}) the flyer is stable for 400 ns and gets decomposed completely when interacting with the shockwave after 1 {mu}s. Material detachments on the edges of the flyer are observed at an early stage of the ablation process (<200 ns) which leads to a pixel smaller than its ablation cross section. For low laser fluence (200 mJ/cm{sup 2}) the flyer has the size of the ablation spot and keeps its shape for nearly 1 {mu}s. The back pressure of the decomposed triazene polymer bends the flyer towards the direction of flight and indications for folding are observed.

  16. Protective effects of low-intensity pulsed ultrasound on aluminum-induced cerebral damage in Alzheimer's disease rat model

    OpenAIRE

    Lin, Wei-Ting; Chen, Ran-Chou; Lu, Wen-Wei; Liu,Shing-Hwa; Yang, Feng-Yi

    2015-01-01

    The protein expressions of neurotrophic factors can be enhanced by low-intensity pulsed ultrasound (LIPUS) stimulation in the brain. The purpose of this study was to demonstrate the protective effect of LIPUS stimulation against aluminum-induced cerebral damage in Alzheimer's disease rat model. LIPUS was administered 7 days before each aluminum chloride (AlCl3) administration, and concomitantly given with AlCl3 daily for a period of 6 weeks. Neurotrophic factors in hippocampus were measured b...

  17. Protective effects of Ginkgo biloba leaf extract on model rats of brain dysfunction induced by aluminum salt

    Institute of Scientific and Technical Information of China (English)

    Qi-haiGONG; QinWU; Dan-liYANG; Xie-nanHUANG; An-shengSUN; Jing-shanSHI

    2004-01-01

    AIM: To examine the protective effects of Ginkgo biloba leaf extract (GbE) on the learning and memory in brain dysfunction model induced by aluminum salt in rats, and to investigate potential mechanisms. METHODS: Wistar rats were given daily aluminum chloride 500 mg·kg·d-1 ig, for one month, followed by continuous exposure via the drinking water containing 1600 ppm

  18. Dietary protein restriction causes modification in aluminum-induced alteration in glutamate and GABA system of rat brain

    Directory of Open Access Journals (Sweden)

    Chatterjee Ajay K

    2003-02-01

    Full Text Available Abstract Background Alteration of glutamate and γ-aminobutyrate system have been reported to be associated with neurodegenerative disorders and have been postulated to be involved in aluminum-induced neurotoxicity as well. Aluminum, an well known and commonly exposed neurotoxin, was found to alter glutamate and γ-aminobutyrate levels as well as activities of associated enzymes with regional specificity. Protein malnutrition also reported to alter glutamate level and some of its metabolic enzymes. Thus the region-wise study of levels of brain glutamate and γ-aminobutyrate system in protein adequacy and inadequacy may be worthwhile to understand the mechanism of aluminum-induced neurotoxicity. Results Protein restriction does not have any significant impact on regional aluminum and γ-aminobutyrate contents of rat brain. Significant interaction of dietary protein restriction and aluminum intoxication to alter regional brain glutamate level was observed in the tested brain regions except cerebellum. Alteration in glutamate α-decarboxylase and γ-aminobutyrate transaminase activities were found to be significantly influenced by interaction of aluminum intoxication and dietary protein restriction in all the tested brain regions. In case of regional brain succinic semialdehyde content, this interaction was significant only in cerebrum and thalamic area. Conclusion The alterations of regional brain glutamate and γ-aminobutyrate levels by aluminum are region specific as well as dependent on dietary protein intake. The impact of aluminum exposure on the metabolism of these amino acid neurotransmitters are also influenced by dietary protein level. Thus, modification of dietary protein level or manipulation of the brain amino acid homeostasis by any other means may be an useful tool to find out a path to restrict amino acid neurotransmitter alterations in aluminum-associated neurodisorders.

  19. Local brain heavy ion irradiation induced Immunosuppression

    Science.gov (United States)

    Lei, Runhong; Deng, Yulin; Huiyang Zhu, Bitlife.; Zhao, Tuo; Wang, Hailong; Yu, Yingqi; Ma, Hong; Wang, Xiao; Zhuang, Fengyuan; Qing, Hong

    Purpose: To investigate the long term effect of acute local brain heavy ion irradiation on the peripheral immune system in rat model. Methodology: Only the brain of adult male Wistar rats were radiated by heavy ions at the dose of 15 Gy. One, two and three months after irradiation, thymus and spleen were analyzed by four ways. Tunel assay was performed to evaluate the percentage of apoptotic cells in thymus and spleen, level of Inflammatory cytokines (IL-2, IL-6, SSAO, and TNF-α) was detected by ELISA assay, the differentiation of thymus T lymphocyte subsets were measured by flow cytometry and the relative expression levels of genes related to thymus immune cell development were measured by using quantitative real-time PCR. Results: Thymus and spleen showed significant atrophy from one month to three months after irradiation. A high level of apoptosis in thymus and spleen were obtained and the latter was more vulnerable, also, high level of inflammatory cytokines were found. Genes (c-kit, Rag1, Rag2 and Sca1) related to thymus lymphocytes’ development were down-regulated. Conclusion: Local area radiation in the rat brain would cause the immunosuppression, especially, the losing of cell-mediated immune functions. In this model, radiation caused inflammation and then induced apoptosis of cells in the immune organs, which contributed to immunosuppression.

  20. Persistent ion beam induced conduction in semiconductor nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Johannes, Andreas; Niepelt, Raphael; Gnauck, Martin; Slowik, Irma; Thielmann, Andreas; Geburt, Sebastian; Schroeder, Ulrich; Stoll, David; Ronning, Carsten [Institut fuer Festkoerper Physik, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 (Germany)

    2011-07-01

    The electrical conductance of single, semiconductor nanowires is investigated in-situ during ion beam exposure. A stark increase in conductance proportional to ion flux and ion energy is observed. The increase in conductance shows remarkable similarities to the persistent photoconduction effect (PPC), which is well known yet not comprehensively understood. Especially ZnO nanowires show a strong increase in conductance (photo and ion induced) that only decays over days. Experiments are performed to investigate the parallels between ion and photo induced conductivity and to examine the underlying mechanisms. The decay rate is very sensitive to the external environment so that surface effects are considered to cause the conduction enhancement.

  1. Study of the wear resistance of ion-plasma coatings based on titanium and aluminum and obtained by magnetron sputtering

    Science.gov (United States)

    Kachalin, G. V.; Mednikov, A. F.; Tkhabisimov, A. B.; Sidorov, S. V.

    2017-05-01

    The paper presents the results of metallographic researches and erosion tests of ion-plasma coatings (based on titanium, aluminum and their nitrides), which were formed on samples of 12Kh13 and EI961 blade steels. Erosion tests and studies of characteristics of obtained by magnetron sputtering coatings were carried out by using a set of research equipment UNU “Erosion-M” NRU “MPEI”. It was found that the formed Ti/Al-TiN/AlN coatings increase the duration of blade steels erosion wear incubation period by at least in 1.5 times and have a layered structure with thicknesses of nitride layers 1.3-1.6 μm and intermediate metallic layers 0.3-0.5 μm, with a total thickness of coatings of 10-14 μm for 12Kh13steel samples and 19-21 μm for EI961 steel samples.

  2. Optimal dose of zinc supplementation for preventing aluminum-induced neurotoxicity in rats****

    Institute of Scientific and Technical Information of China (English)

    Hao Lu; Yugang Jiang; Jianyang Hu; Jing Li; Wei Pang; Yandan Hu; Hongpeng Yang; Wenjie Li; Chengyu Huang; Mingman Zhang

    2013-01-01

    Zinc supplementation can help maintain learning and memory function in rodents. In this study, we hypothesized that zinc supplementation could antagonize the neurotoxicity induced by aluminum in rats. Animals were fed a diet containing different doses of zinc (50, 100, 200 mg/kg) for 9 weeks, and oral y administered aluminum chloride (300 mg/kg daily) from the third week for 7 consecutive weeks. Open-field behavioral test results showed that the number of rearings in the group given the 100 mg/kg zinc supplement was significantly increased compared with the group given the 50 mg/kg zinc supplement. Malondialdehyde content in the cerebrum was significantly decreased, while dopamine and 5-hydroxytryptamine levels were increased in the groups given the diet plemented with 100 and 200 mg/kg zinc, compared with the group given the diet supplemented with 50 mg/kg zinc. The acetylcholinesterase activity in the cerebrum was significantly decreased in the group given the 100 mg/kg zinc supplement. Hematoxylin-eosin staining revealed evident patho-logical damage in the hippocampus of rats in the group given the diet supplemented with 50 mg/kg zinc, but the damage was attenuated in the groups given the diet supplemented with 100 and 200 mg/kg zinc. Our findings suggest that zinc is a potential neuroprotective agent against alumi-num-induced neurotoxicity in rats, and the optimal dosages are 100 and 200 mg/kg.

  3. Oxaliplatin-Induced Peripheral Neuropathy via TRPA1 Stimulation in Mice Dorsal Root Ganglion Is Correlated with Aluminum Accumulation.

    Directory of Open Access Journals (Sweden)

    Jin-Hee Park

    Full Text Available Oxaliplatin is a platinum-based anticancer drug used to treat metastatic colorectal, breast, and lung cancers. While oxaliplatin kills cancer cells effectively, it exhibits several side effects of varying severity. Neuropathic pain is commonly experienced during treatment with oxaliplatin. Patients describe symptoms of paresthesias or dysesthesias that are triggered by cold (acute neuropathy, or as abnormal sensory or motor function (chronic neuropathy. In particular, we found that aluminum levels were relatively high in some cancer patients suffering from neuropathic pain based on clinical observations. Based on these findings, we hypothesized that aluminum accumulation in the dorsal root ganglion (DRG in the course of oxaliplatin treatment exacerbates neuropathic pain. In mice injected with oxaliplatin (three cycles of 3 mg/kg i.p. daily for 5 days, followed by 5 days of rest, we detected cold allodynia using the acetone test, but not heat hyperalgesia using a hot plate. However, co-treatment with aluminum chloride (AlCl3∙6H2O; 7 mg/kg i.p. for 14 days: equivalent 0.78 mg/kg of elemental Al and oxaliplatin (1 cycle of 3 mg/kg i.p. daily for 5 days, followed by 5 days of rest synergistically induced cold allodynia as well as increased TRPAl mRNA and protein expression. Inductively Coupled Plasma Mass Spectrometry (ICP-MS analysis showed a significant increase in aluminum concentrations in the DRG of mice treated with aluminum chloride and oxaliplatin compared to aluminum chloride alone. Similarly, in a mouse induced-tumor model, aluminum concentrations were increased in DRG tissue and tumor cells after oxaliplatin treatment. Taken together, these findings suggest that aluminum accumulation in the DRG may exacerbate neuropathic pain in oxaliplatin-treated mice.

  4. Microstructure and Wear Behaviour of Laser-Induced Thermite Reaction Al2O3 Ceramic Coatings on Pure Aluminum and AA7075 Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    HUANG Kaijin; LIN Xin; XIE Changsheng; T M Yue

    2008-01-01

    Wear-resistant laser-induced thermite reaction Al2O3 ceramic coatings can be fabricated on pure Al and AA7075 aluminum alloy by laser cladding(one-step method)and laser cladding followed by laser re-melting(two-step method)using mixed powders CuO-Al-SiO2 in order to improve the wear properties of aluminum and aluminum alloy,respectively.The microstructure of the coatings was characterized by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The wear resistance of the coatings was evaluated under dry sliding wear test condition at room temperature.Owing to the presence of hard a-Al2O3 and γ-Al2O,3phases,the coatings exhibited excellent wear resistance.In addition,the wear resistance of the coatings fabricated by two-step method is superior to that of the coatings fabricated by one-step method.

  5. The study of corrosion behavior of laser induced surface improvement (LISI) on steel and aluminum substrates

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, N.; Vasanth, K.L.

    1999-07-01

    Laser Induced Surface Improvement (LISI) is a new process developed by University of Tennessee Space Institute (UTSI) which employs lasers to melt precursor coatings and portions of the substrate to form a durable corrosion resistant surface. The LISI surface can be tailored to yield a composition that provides minimum impact to the base substrate material while giving good corrosion characteristics. The LISI surface treatment of tungsten carbide was applied on 7075 and 6061 aluminum alloys. The LISI treatment uses a chromium/nickel mixture and a stainless steel type mixture (pseudo stainless steel of 18 wt% chromium, 8 wt% nickel and a trace amount of manganese and silicon) on steel alloy 1010. The corrosion characteristics of these samples were determined in 3.5 wt% NaCl aqueous solution using linear polarization resistance technique. Potentiodynamic scans were run to determine the corrosion rates and optical microscopy was used to examine pitting characteristics of the different surface coatings. The effectiveness of the LISI modified surfaces to protect both steel and aluminum substrates is discussed.

  6. Note: Ion-induced secondary electron emission from oxidized metal surfaces measured in a particle beam reactor

    Science.gov (United States)

    Marcak, Adrian; Corbella, Carles; de los Arcos, Teresa; von Keudell, Achim

    2015-10-01

    The secondary electron emission of metals induced by slow ions is characterized in a beam chamber by means of two coaxial semi-cylindrical electrodes with different apertures. The voltages of the outer electrode (screening), inner electrode (collector), and sample holder (target) were set independently in order to measure the effective yield of potential and kinetic electron emissions during ion bombardment. Aluminum samples were exposed to quantified beams of argon ions up to 2000 eV and to oxygen atoms and molecules in order to mimic the plasma-surface interactions on metallic targets during reactive sputtering. The variation of electron emission yield was correlated to the ion energy and to the oxidation state of Al surfaces. This system provides reliable measurements of the electron yields in real time and is of great utility to explore the fundamental surface processes during target poisoning occurring in reactive magnetron sputtering applications.

  7. Note: Ion-induced secondary electron emission from oxidized metal surfaces measured in a particle beam reactor

    Energy Technology Data Exchange (ETDEWEB)

    Marcak, Adrian; Corbella, Carles, E-mail: carles.corbella@rub.de; Keudell, Achim von [Research Group Reactive Plasmas, Ruhr-University Bochum, 44801 Bochum (Germany); Arcos, Teresa de los [Technical and Macromolecular Chemistry, Paderborn University, 33098 Paderborn (Germany)

    2015-10-15

    The secondary electron emission of metals induced by slow ions is characterized in a beam chamber by means of two coaxial semi-cylindrical electrodes with different apertures. The voltages of the outer electrode (screening), inner electrode (collector), and sample holder (target) were set independently in order to measure the effective yield of potential and kinetic electron emissions during ion bombardment. Aluminum samples were exposed to quantified beams of argon ions up to 2000 eV and to oxygen atoms and molecules in order to mimic the plasma-surface interactions on metallic targets during reactive sputtering. The variation of electron emission yield was correlated to the ion energy and to the oxidation state of Al surfaces. This system provides reliable measurements of the electron yields in real time and is of great utility to explore the fundamental surface processes during target poisoning occurring in reactive magnetron sputtering applications.

  8. Effect of lithium or aluminum substitution on the characteristics of graphite for anode of lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    GUO Huajun; LI Xinhai; WANG Zhixing; PENG Wenjie; GUO Yongxing

    2003-01-01

    Modification of graphite for anode of lithium ion batteries is investigated. Results of X-ray diffraction shows lithium and aluminum exists as Li compound (CH3COOLi@2H2O) and Al compound (AlD3) in the graphite, respectiovely.The Bmnauer-Emmer-Teller (BET) surface area of the modified graphite increases. According to the electrochemical measurements of Li/C cell and prototype Li-ion batteries, the Li-doped graphite has large reversible capacity of 312.2mA@h/g, low irreversible capacity of 52.9 mA@h/g, and high initial coulombic efficiency of 85.51%. The 063448 size prototype battery with Li-doped graphite anode has large discharge capacity of 845 mA@h and good cycling performance. The initial charge/discharge characteristic of Al-doped graphite is close to those of undoped graphite, but the prototype battery with Al-doped anode shows the best cycling performance with capacity retention ratio of 94.06% at the 200th cycle.

  9. Local charge exchange of He{sup +} ions at Aluminum surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Riccardi, P., E-mail: pierfrancesco.riccardi@fis.unical.it [Dipartimento di Fisica, Università della Calabria and INFN – Gruppo collegato di Cosenza, Via P. Bucci cubo 33C, Arcavacata di Rende, Cosenza (Italy); Sindona, A. [Dipartimento di Fisica, Università della Calabria and INFN – Gruppo collegato di Cosenza, Via P. Bucci cubo 33C, Arcavacata di Rende, Cosenza (Italy); Dukes, C.A. [Laboratory for Astrophysics and Surface Physics, Materials Science and Engineering University of Virginia, Charlottesville, VA 22904 (United States)

    2017-04-04

    We report on experiments designed to observe the correlation between the autoionization of doubly excited helium atoms and the Auger decay of 2p vacancies in Al. The autoionizing states are formed when incident He{sup +*} and He{sup ++} are neutralized by resonant electron capture at the surface. 2p excitation in Al occurs in dielectronic charge transfer during the close encounter of an excited helium ion and an Al atom. These results clarify the mechanism for Al-2p excitation in the case of singly charged ground state He{sup +}(1s) ion impact, where the dielectronic transition occurs after promotion of the 1s electron of incoming ions. - Highlights: • We observe the correlation between autoionization of doubly excited helium atoms and the Auger decay of 2p vacancies in Al. • 2p excitation in Al occurs in dielectronic charge transfer during the close encounter of an excited helium ion and an Al atom. • These results clarify the mechanism for Al-2p excitation in the case of singly charged ground state He{sup +}(1s) ion impact.

  10. Determination of Aluminum in Nickel-Based Superalloys by Using Laser-Induced Breakdown Spectroscopy%Determination of Aluminum in Nickel-Based Superalloys by Using Laser-Induced Breakdown Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    朱德华; 王茜; 倪晓武; 陈建平; 陆建

    2011-01-01

    Laser-induced breakdown spectroscopy (LIBS) was developed to detect aluminum in nickel-based superalloys (K417, GH4033, DZ125L, З ∏742y) using a non-intensified, non-gated, low-cost detection system. The precision of LIBS depends strongly on the experimental conditions. The calibration curves of Al(I)394.4 nm and Al(I)396.2 nm under the optimum experimental parameters are presented. Finally the limit of detection (LOD) for aluminum is calculated from the experimental data, which is in the range of 0.09% to 0.1% by weight.

  11. Molecular characterization of microbial mutations induced by ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ichida, Hiroyuki [Graduate School of Science and Technology, Chiba University, Matsudo, Chiba 271-8510 (Japan); Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)], E-mail: ichida@riken.jp; Matsuyama, Tomoki [Cellular Biochemistry Laboratory, Discovery Research Institute, RIKEN, Wako, Saitama 351-0198 (Japan); Ryuto, Hiromichi [Accelerator Operation Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Hayashi, Yoriko [Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Fukunishi, Nobuhisa [Accelerator Operation Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Abe, Tomoko [Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Koba, Takato [Graduate School of Science and Technology, Chiba University, Matsudo, Chiba 271-8510 (Japan)

    2008-03-01

    A positive selection system for gene disruption using a sucrose-sensitive transgenic rhizobium was established and used for the molecular characterization of mutations induced by ion beam irradiations. Single nucleotide substitutions, insertions, and deletions were found to occur in the sucrose sensitivity gene, sacB, when the reporter line was irradiated with highly accelerated carbon and iron ion beams. In all of the insertion lines, fragments of essentially the same sequence and of approximately 1188 bp in size were identified in the sacB regions. In the deletion lines, iron ions showed a tendency to induce larger deletions than carbon ions, suggesting that higher LET beams cause larger deletions. We found also that ion beams, particularly 'heavier' ion beams, can produce single gene disruptions and may present an effective alternative to transgenic approaches.

  12. Copper ion implanted aluminum nitride dilute magnetic semiconductors (DMS) prepared by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A., E-mail: attaullah77@yahoo.com [National Institute of Lasers and Optronics (NILOP), PO Nilore, Islamabad (Pakistan); DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Ahmad, Jamil [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Ahmad, Ishaq [Experimental Physics Lab, National Center for Physics (NCP), Islamabad (Pakistan); Mehmood, Mazhar [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan); Mahmood, Arshad [National Institute of Lasers and Optronics (NILOP), PO Nilore, Islamabad (Pakistan); Rasheed, Muhammad Asim [DMME, Pakistan Institute of Engineering and Applied Science (PIEAS), PO Nilore, Islamabad (Pakistan)

    2014-10-30

    Highlights: • AlN:Cu dilute magnetic semiconductors were successfully prepared by molecular beam epitaxy followed by Cu{sup +} implantation. • Room temperature ferromagnetism was observed after annealing the samples at appropriate temperature. • XRD and Raman spectrometry excluded the possibility of formation of any secondary phases. • By doping intrinsically nonmagnetic dopants (Cu), it has been proved experimentally that their precipitates do not contribute to ferromagnetism. • The reason for ferromagnetism in Cu-doped AlN as observed was explained on the basis of p–d hybridization mechanism (Wu et al.). - Abstract: Diluted magnetic semiconductor (DMS) AlN:Cu films were fabricated by implanting Cu{sup +} ions into AlN thin films at various ion fluxes. AlN films were deposited on c-plane sapphire by molecular beam epitaxy followed by Cu{sup +} ion implantation. The structural and magnetic characterization of the samples was performed through Rutherford backscattering and channeling spectrometry (RBS/C), X-ray diffraction (XRD), Raman spectroscopy, vibrating sample magnetometer (VSM) and SQUID. Incorporation of copper into the AlN lattice was confirmed by RBS, while XRD revealed that no new phase was formed as a result of ion implantation. RBS also indicated formation of defects as a result of implantation process and the depth and degree of damage increased with an increase in ion fluence. Raman spectra showed only E{sub 2} (high) and A{sub 1} (LO) modes of wurtzite AlN crystal structure and confirmed that no secondary phases were formed. It was found that both Raman modes shift with Cu{sup +} fluences, indicating that Cu ion may go to interstitial or substitutional sites resulting in distortion or damage of lattice. Although as implanted samples showed no magnetization, annealing of the samples resulted in appearance of room temperature ferromagnetism. The saturation magnetization increased with both the annealing temperature as well as with ion

  13. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    Science.gov (United States)

    Ahmad, S. B.; McNeill, F. E.; Byun, S. H.; Prestwich, W. V.; Seymour, C.; Mothersill, C. E.

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced "bystander effects" studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 × 1013 H+/cm2 s. The average saturation value for the photon output was found to be 40 × 106 cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 × 103, 10 × 106, and 35 × 106 cps for wavelengths of 280 ± 5 nm, 320 ± 5 nm and 340 ± 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a "damage cross section" of the order of 10-14 cm2. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  14. Effect of ECR on the Expression of Tau from the Brain of the Mice Induced by Overload Aluminum Salt

    Institute of Scientific and Technical Information of China (English)

    YANGSu-Fen; WUZhong-Jun; YANGZheng-Qin; LIYu; WuQin; ZHOUQi-Xin; SHIJing-Shan

    2004-01-01

    Aim: To study the effect of Ecdysterone (ECR) on the expression of Tau from the cerebral cortice and hippocampus and behaviors in passive avoidance reaction and spatial discrimination of the mice induced by overload aluminum salt.Methods Fourty-five NIH mice were randomly divided into five groups, the control group, the model group, the treated

  15. Modeling of radiation-induced sink evolution in 6061 aluminum alloy in nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sang Il; Kim, Ji Hyun [Department of Nuclear Science and Engineering, School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan (Korea, Republic of); Lee, Gyeong-Geun; Kwon, Junhyun [Division of Nuclear Materials Research, Korea Atomic Energy Research Institute (KAERI), Daejeon (Korea, Republic of)

    2016-11-15

    The objective of this study is a detailed analysis of the radiation effects on sink generation and growth in order to understand the phenomenon of irradiation hardening of 6061 aluminum alloy in research reactor conditions. In order to have a fundamental understanding, various sink behavior characteristics such as size and number density of dislocation loop, void, and precipitation were calculated and examined. Thereafter, theoretical assessment of various sink effects on irradiation hardening was conducted based on the mean field rate theory (MFRT). Dislocation loop, void, and precipitation were examined by defect flux. For the quantitative analysis of radiation-induced degradation, change in sink size was calculated using number density. 6061 Alloy showed great dependence on precipitation generation and growth. However, dislocation loop and void did not have any significant effect on irradiation hardening. Finally, the behavior of sinks was compared with the experimental results for validation. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Study of polycrystalline silicon obtained by aluminum-induced crystallization depending on process conditions

    Science.gov (United States)

    Pereyaslavtsev, Alexander; Sokolov, Igor; Sinev, Leonid

    2016-11-01

    In this paper, we have decided to consider an alternative method of producing polycrystalline silicon and study change of its electrophysical characteristics depending on process parameters. As an alternative low-pressure chemical vapor deposition method appears aluminum-induced crystallization (AIC), which allows to obtain a polycrystalline silicon film is significantly larger grain size, thereby reducing contribution of grain boundaries. A comprehensive study of polycrystalline silicon was carried out using a variety of microscopic (OM, SEM) and spectroscopic (RAMAN, XPS) and diffraction (EBSD, XRD) analytic methods. We also considered possibility of self-doping in AIC, result of which was obtained polycrystalline silicon with different resistance. Additionally considered changes in temperature coefficient of resistance depending on technological parameters of AIC process.

  17. Threshold for plasma phase transition of aluminum single crystal induced by hypervelocity impact

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Yuanyuan; Zhang, Qingming, E-mail: qmzhang@bit.edu.cn [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2015-12-15

    Molecular dynamics method is used to study the threshold for plasma phase transition of aluminum single crystal induced by hypervelocity impact. Two effective simulation methods, piston-driven method and multi-scale shock technique, are used to simulate the shock wave. The simulation results from the two methods agree well with the experimental data, indicating that the shock wave velocity is linearly dependent on the particle velocity. The atom is considered to be ionized if the increase of its internal energy is larger than the first ionization energy. The critical impact velocity for plasma phase transition is about 13.0 km/s, corresponding to the threshold of pressure and temperature which is about 220 GPa and 11.0 × 10{sup 3 }K on the shock Hugoniot, respectively.

  18. Calculation of power consumption and induced heat for EMC aluminum ingots

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The electrical parameters and power consumption in electromagnetic casting of aluminum ingots were calculated and discussed in detail. Moreover, the induced heat was calculated with the eddy current within the liquid column. It is found that the calculated values agree with the measured results. Once the inductor current was given, the magnetic flux density in electromagnetic casting could be calculated and the electromagnetic pressure could be obtained. The key to the EMC is the balance between the electromagnetic pressure and the metallostatic pressure. As the liquid column, controlled by the casting speed and pouring speed through a magnetic sensor, is kept away from the inductor, a gap forms linear relationship between the inductor and ingot. The bigger the current is, the smaller the ingot size is.

  19. Ion beam induced luminescence from diamond using an MeV ion microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A.; Jamieson, D. N.; Prawer, S.; Allen, M.G. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1993-12-31

    Analysis of the luminescence induced by a MeV ion beam offers the potential to provide useful information about the chemical properties of atoms in crystals to complement the information provided by more traditional Ion Beam Analysis (IBA) such as Rutherford Backscattering Spectrometry (RBS), ion channeling and Particle Induced X-ray Emission (PIXE). Furthermore, the large penetration depth of the MeV ion beam offers several advantages over the relatively shallow penetration of keV electrons typically employed in cathodoluminescence. An Ion Beam Induced Luminescence (IBIL) detection system was developed for the Melbourne microprobe that allows the spatial mapping of the luminescence signal along with the signals from RBS and PIXE. Homoepitaxial diamond growth has been studied and remarkable shifts in the characteristic blue luminescence of diamond towards the green were observed in the overgrowth. This has been tentatively identified as being due to transition metal inclusions in the epitaxial layers. 8 refs., 2 refs.

  20. Deposition and characterization of silicon thin-films by aluminum-induced crystallization

    Science.gov (United States)

    Ebil, Ozgenc

    Polycrystalline silicon (poly-Si) as a thin-film solar cell material could have major advantages compared to non-silicon thin-film technologies. In theory, thin-film poly-Si may retain the performance and stability of c-Si while taking advantage of established manufacturing techniques. However, poly-Si films deposited onto foreign substrates at low temperatures typically have an average grain size of 10--50 nm. Such a grain structure presents a potential problem for device performance since it introduces an excessive number of grain boundaries which, if left unpassivated, lead to poor solar cell properties. Therefore, for optimum device performance, the grain size of the poly-Si film should be at least comparable to the thickness of the films. For this project, the objectives were the deposition of poly-Si thin-films with 2--5 mum grain size on glass substrates using in-situ and conventional aluminum-induced crystallization (AIC) and the development of a model for AIC process. In-situ AIC experiments were performed using Hot-Wire Chemical Vapor Deposition (HWCVD) both above and below the eutectic temperature (577°C) of Si-Al binary system. Conventional AIC experiments were performed using a-Si layers deposited on aluminum coated glass substrates by Electron-beam deposition, Plasma Enhanced Chemical Vapor Deposition (PECVD) and HWCVD. Continuous poly-Si films with an average grain size of 10 mum on glass substrates were achieved by both in-situ and conventional aluminum-induced crystallization of Si below eutectic temperature. The grain size was determined by three factors; the grain structure of Al layer, the nature of the interfacial oxide, and crystallization temperature. The interface oxide was found to be crucial for AIC process but not necessary for crystallization itself. The characterization of interfacial oxide layer formed on Al films revealed a bilayer structure containing Al2O3 and Al(OH)3 . The effective activation energy for AIC process was determined

  1. S-Allyl-Cysteines Reduce Amelioration of Aluminum Induced Toxicity in Rats

    Directory of Open Access Journals (Sweden)

    Sadhana Shrivastava

    2011-01-01

    Full Text Available Problem statement: Aluminum (Al is a trivalent cation found in its ionic form in most kinds of animal tissues and in natural waters everywhere. Approach: It is a potent neurotoxin and has been associated in the pathogenesis of several clinical disorders including Alzheimer’s disease. Results: The aim of the study was to demonstrate the protective effect of S-Allyl-Cysteines (SAC against Al-induced toxicity in rat model on certain biochemical parameters, lipid peroxidation and oxidative stress enzymes of white albino rats. Six rats per group were divided into various treatment groups. Group one rats were given normal saline and served as control group. Group two animals received Al as aluminum nitrate 32.5 mg (i.p. for the induction of toxicity. Group three to five received different doses of SAC (25, 50 and 100 mg kg-1 for 3 days after 24 h of Al toxicity. Rats were orally administered their respective doses every day for 3 days. Evaluations were made in blood and tissues. The activity of Acetylcholinesterase (AchE was inhibited in all the parts of brain after Al intoxication. Significant rise were observed the Activities of Serum Transaminases (AST and ALT after toxicant exposure. The activity of â-Aminolevulinic acid Dehydratase (ALAD in blood and â-Aminolevulinic Acid Synthetase (ALAS in brain was decreased after Al exposure. Al significant increased cholesterol, triglyceride, creatinine and urea level in serum. TBARS level was significantly higher and GSH content were significantly lower during toxicity. Total and esterified cholesterol in liver, kidney and brain were increased after Al exposure. Histopathological changes in liver, kidney and brain were also recouped with the therapy. Conclusion/Recommendations: Our data proved that SAC which is a bioactive and bioavailable component of garlic has organosulfur compounds which regulates the thiol status of the cell and scavenges free radicals and work as an antioxidant. Thus SAC

  2. Investigation of the local thermodynamic equilibrium of laser-induced aluminum plasma by Thomson scattering technique

    Energy Technology Data Exchange (ETDEWEB)

    Mendys, A., E-mail: agata.mendys@uj.edu.pl [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. Reymonta 4, 30-059 Kraków (Poland); Kański, M. [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. Reymonta 4, 30-059 Kraków (Poland); Farah-Sougueh, A. [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. Reymonta 4, 30-059 Kraków (Poland); GREMI — site de Bourges, Université d' Orléans, CNRS, rue Gaston Berger BP 4043, 18028 Bourges (France); Pellerin, S. [GREMI — site de Bourges, Université d' Orléans, CNRS, rue Gaston Berger BP 4043, 18028 Bourges (France); Pokrzywka, B. [Obserwatorium Astronomiczne na Suhorze, Uniwersytet Pedagogiczny, ul. Podchorażych 2, 30-084 Kraków (Poland); Dzierżęga, K. [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagielloński, ul. Reymonta 4, 30-059 Kraków (Poland)

    2014-06-01

    A laser Thomson scattering method was applied to investigate the local Saha–Boltzmann equilibrium in aluminum laser-induced plasma. Plasma was created in ambient air using 4.5 ns pulses from a Nd:YAG laser at 532 nm, focused on an Al target. Spatially resolved measurements, performed for the time interval between 600 ns and 3 μs, show electron density and temperature to decrease from 3.4 × 10{sup 23} m{sup −3} to 0.5 × 10{sup 23} m{sup −3} and from 61,000 K to 13,000 K in the plasma core. The existence of local thermodynamic equilibria in the plasma was verified by comparing the rates of the collisional to radiative processes (the McWhirter criterion), as well as relaxation times and diffusion lengths of different plasma species, with the appropriate rate of electron density evolution and its gradients at given, experimentally determined, electron temperatures. We found these criteria to be much easier to satisfy for metallic plasma species than for nitrogen. The criteria are also easier to satisfy in the plasma core of higher electron density. - Highlights: • Laser Thomson scattering method was applied to investigate aluminum laser-induced plasma. • Spatio-temporal evolution of electron temperature and density was determined. • Three criteria for existence of local thermodynamic equilibrium were verified. • Criteria are much easier to satisfy for metallic plasma species than for nitrogen. • Criteria are easier to satisfy at earlier times and in the plasma core.

  3. Thermal Effect on Structure of Silver in Ion-Exchanged Soda-Lime Glasses and Aluminum-Doped Zinc Oxide Films

    Directory of Open Access Journals (Sweden)

    Paul W. Wang

    2011-01-01

    Full Text Available Heat treatment is commonly used during device processing in order to achieve specific functionalities of the devices. How a series of heat treatment applies to accomplish this goal can be found in the literature. However, specific properties of the devices after the treatment are more emphasized than the details of the structural modifications in the industrial applications. In this paper, it is intended to illustrate the fundamental changes in the structure due to heat treatment which result in the desired physical properties of the devices. Two study cases, Ag ion-exchanged soda-lime glasses and aluminum doped ZnO (AZO films, were illustrated. The changes in chemical states, the structural modification during and after heat treatment are explored. By understanding how the metallic Ag formed and accumulated during annealing, an optimum heat treatment to grow the proper size and density of silver quantum dots in the films are possible. Post annealing effect on the AZO films shows that the crystallinity, the peak positions shifts, and grain sizes were changed after annealing. Both illustrated cases indicate thermally induced changes in chemical state, the stress release, and rearrangement of atoms in materials during and after annealing.

  4. Gold ion beams induced desorption studies for Booster Nuclotron

    Science.gov (United States)

    Kuznetsov, A. B.; Tuzikov, A. V.; Philippov, A. V.

    2016-12-01

    Heavy ions induced pressure rise is one of the machine limits. The calculation results of the gold ion beam 197Au31+ losses due to residual gas interaction in view of desorption of adsorbed particles on the Booster Nuclotron vacuum chamber surface are discussed.

  5. Peptide fragmentation by keV ion-induced dissociation

    NARCIS (Netherlands)

    Bari, S.; Hoekstra, R.A.; Schlathölter, T.A.

    2010-01-01

    We have studied multiple ionization and dissociation of a trapped protonated peptide (leucine enkephalin) as induced by keV singly and doubly charged ions (H(+), He(+,) (2+)) to demonstrate the potential of keV ions as a future tool for peptide identification. In contrast to conventional excitation

  6. Aluminum ions alter the function of non-specific phospholipase C through the changes in plasma membrane physical properties.

    Science.gov (United States)

    Pejchar, Přemysl; Martinec, Jan

    2015-01-01

    The first indication of the aluminum (Al) toxicity in plants growing in acidic soils is the cessation of root growth, but the detailed mechanism of Al effect is unknown. Here we examined the impact of Al stress on the activity of non-specific phospholipase C (NPC) in the connection with the processes related to the plasma membrane using fluorescently labeled phosphatidylcholine. We observed a rapid and significant decrease of labeled diacylglycerol (DAG), product of NPC activity, in Arabidopsis seedlings treated with AlCl₃. Interestingly, an application of the membrane fluidizer, benzyl alcohol, restored the level of DAG during Al treatment. Our observations suggest that the activity of NPC is affected by Al-induced changes in plasma membrane physical properties.

  7. Heavy metal ion removal by thiol functionalized aluminum oxide hydroxide nanowhiskers

    Science.gov (United States)

    Xia, Zhiyong; Baird, Lance; Zimmerman, Natasha; Yeager, Matthew

    2017-09-01

    In this study, we developed a cost effective method of using thiol functionalized γ-aluminum oxide hydroxide (γ-AlOOH) filters for removing three key heavy metals from water: mercury, lead, and cadmium under non-concomitant conditions. Compared to non-thiol treated γ-AlOOH filters, the introduction of thiol functional groups greatly improved the heavy metal removal efficiency under both static and dynamic filtration conditions. The adsorption kinetics of thiol functionalized γ-AlOOH were investigated using the Lagergren first order and pseudo-second order kinetics models; whereas the isothermal adsorption behavior of these membranes was revealed through the Langmuir and Freundlich models. Heavy metal concentration was quantified by Inductively Coupled Plasma-Mass Spectroscopy, and the thiol level on γ-AlOOH surface was measured by a colorimetric assay using Ellman's reagent. X-ray photoelectron spectroscopy was used to further address the surface sulfur state on the membranes after heavy metal exposure. Mechanisms for heavy metal adsorption were also discussed.

  8. Protective effects of low-intensity pulsed ultrasound on aluminum-induced cerebral damage in Alzheimer's disease rat model

    Science.gov (United States)

    Lin, Wei-Ting; Chen, Ran-Chou; Lu, Wen-Wei; Liu, Shing-Hwa; Yang, Feng-Yi

    2015-04-01

    The protein expressions of neurotrophic factors can be enhanced by low-intensity pulsed ultrasound (LIPUS) stimulation in the brain. The purpose of this study was to demonstrate the protective effect of LIPUS stimulation against aluminum-induced cerebral damage in Alzheimer's disease rat model. LIPUS was administered 7 days before each aluminum chloride (AlCl3) administration, and concomitantly given with AlCl3 daily for a period of 6 weeks. Neurotrophic factors in hippocampus were measured by western blot analysis. Behavioral changes in the Morris water maze and elevated plus maze were examined in rats after administration of AlCl3. Various biochemical analyses were performed to evaluate the extent of brain damages. LIPUS is capable of prompting levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and vascular endothelial growth factor (VEGF) in rat brain. AlCl3 administration resulted in a significant increase in the aluminum concentration, acetylcholinesterase activity and beta-amyloid (Aβ) deposition in AlCl3 treated rats. LIPUS stimulation significantly attenuated aluminum concentration, acetylcholinesterase activity, Aβ deposition and karyopyknosis in AlCl3 treated rats. Furthermore, LIPUS significantly improved memory retention in AlCl3-induced memory impairment. These experimental results indicate that LIPUS has neuroprotective effects against AlCl3-induced cerebral damages and cognitive dysfunction.

  9. On the characteristics of ion implanted metallic surfaces inducing dropwise condensation of steam.

    Science.gov (United States)

    Rausch, Michael H; Leipertz, Alfred; Fröba, Andreas P

    2010-04-20

    The present work provides new information on the characteristics of ion implanted metallic surfaces responsible for the adjustment of stable dropwise condensation (DWC) of steam. The results are based on condensation experiments and surface analyses via contact angle (CA) and surface free energy (SFE) measurements as well as scanning electron microscopy (SEM). For studying possible influences of the base material and the implanted ion species, commercially pure titanium grade 1, aluminum alloy Al 6951, and stainless steel AISI 321 were treated with N(+), C(+), O(+), or Ar(+) using ion beam implantation technology. The studies suggest that chemically inhomogeneous surfaces are instrumental in inducing DWC. As this inhomogeneity is apparently caused by particulate precipitates bonded to the metal surface, the resulting nanoscale surface roughness may also influence the condensation form. On such surfaces nucleation mechanisms seem to be capable of maintaining DWC even when CA and SFE measurements indicate increased wettability. The precipitates are probably formed due to the supersaturation of ion implanted metal surfaces with doping elements. For high-alloyed materials like AISI 321 or Hastelloy C-276, oxidation stimulated by the condensation process obviously tends to produce similar surfaces suitable for DWC.

  10. 换流站内冷水中铝离子的监测%The monitor of Aluminum ion in cooling water of converter stations

    Institute of Scientific and Technical Information of China (English)

    田兴旺; 张蓬鹤; 吴巍; 乐文静

    2012-01-01

    All of the inside cooling water dispose system of DC project in converter stations exist the problem of serious canker and aggradation, according to a mass of analyzing, the scale formation of aluminum ion is serious, in order to prevent in time, it needs online monitoring. This paper mainly introduce the method about monitoring of Aluminum ion in cooling water of converter stations.%各换流站直流工程内冷水处理系统均存在严重的腐蚀和沉积问题,经多方面分析,铝离子结垢比较严重,需要通过在线监测来进行及时预防.本文主要介绍内冷水中铝离子的在线监测方法.

  11. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, S.B., E-mail: ahmad.rabilal@gmail.com [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); McNeill, F.E., E-mail: fmcneill@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); Byun, S.H., E-mail: soohyun@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); Prestwich, W.V., E-mail: prestwic@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); Seymour, C., E-mail: seymouc@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); Mothersill, C.E., E-mail: mothers@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada)

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced 'bystander effects' studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 Multiplication-Sign 10{sup 13} H{sup +}/cm{sup 2} s. The average saturation value for the photon output was found to be 40 Multiplication-Sign 10{sup 6} cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 Multiplication-Sign 10{sup 3}, 10 Multiplication-Sign 10{sup 6}, and 35 Multiplication-Sign 10{sup 6} cps for wavelengths of 280 {+-} 5 nm, 320 {+-} 5 nm and 340 {+-} 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a 'damage cross section' of the order of 10{sup -14} cm{sup 2}. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  12. Investigation of thermodynamic equilibrium in laser-induced aluminum plasma using the H{sub α} line profiles and Thomson scattering spectra

    Energy Technology Data Exchange (ETDEWEB)

    Cvejić, M., E-mail: marko.cvejic@ipb.ac.rs, E-mail: krzysztof.dzierzega@uj.edu.pl [Institute of Physics, University of Belgrade, P.O. Box 68, 11080 Belgrade (Serbia); Faculty of Physics, Weizmann Institute of Science, Rehovot 7610001 (Israel); Dzierżęga, K., E-mail: marko.cvejic@ipb.ac.rs, E-mail: krzysztof.dzierzega@uj.edu.pl; Pięta, T. [M. Smoluchowski Institute of Physics, Jagellonian University, ul. Łojasiewicza 11, 30-348 Kraków (Poland)

    2015-07-13

    We have studied isothermal equilibrium in the laser-induced plasma from aluminum pellets in argon at pressure of 200 mbar by using a method which combines the standard laser Thomson scattering and analysis of the H{sub α}, Stark-broadened, line profiles. Plasma was created using 4.5 ns, 4 mJ pulses from a Nd:YAG laser at 1064 nm. While electron density and temperature were determined from the electron feature of Thomson scattering spectra, the heavy particle temperature was obtained from the H{sub α} full profile applying computer simulation including ion-dynamical effects. We have found strong imbalance between these two temperatures during entire plasma evolution which indicates its non-isothermal character. At the same time, according to the McWhirter criterion, the electron density was high enough to establish plasma in local thermodynamic equilibrium.

  13. Experimental Investigation of DNA Damage Induced by Heavy Ions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    DNA is considered the critical target for radiobiological effects. It is highly important to study DNAdamage induced by ionizing radiation. Especially DNA double strand breaks have been identified as themost initial damage. In this experiment, DNA double strand breaks induced by heavy ions wereinvestigated with atomic force microscopy (AFM).

  14. Failure analysis of an aluminum alloy material framework component induced by casting defects

    Science.gov (United States)

    Li, Bo; Hu, Weiye

    2017-09-01

    Failure analysis on a fractured radome framework component was carried out through visual observations, metallographic examination using optical microscope, fractog-raphy inspections using scanning electron microscope and chemical composition analysis. The failed frame was made of casting Al–Si7–Mg0.4 aluminum alloy. It had suffered a former vi-bration performance tests. It was indicated that the fractures were attributed to fatigue cracks which were induced by casting porosities at the outer surfaces of frame. Failure analysis was carefully conducted for the semi-penetrating crack appearing on the framework. According to the fractography inspected by scanning electron microscope, it was indicated that numerous casting porosities at the outer surface of the framework played the role of multiple fracture sources due to some applied stresses. Optical microstructure observations suggested that the dendrite-shaped casting porosities largely contributed to the crack-initiation. The groove-shaped structure at roots of spatial convex-bodies on the edge of casting porosities supplied the preferred paths of the crack-propagation. Besides, the brittle silicon eutectic particles distrib-uting along grain boundaries induced the intergranular fracture mode in the region of the over-load final fracture surface.

  15. Aluminum chloride induces neuroinflammation, loss of neuronal dendritic spine and cognition impairment in developing rat.

    Science.gov (United States)

    Cao, Zheng; Yang, Xu; Zhang, Haiyang; Wang, Haoran; Huang, Wanyue; Xu, Feibo; Zhuang, Cuicui; Wang, Xiaoguang; Li, Yanfei

    2016-05-01

    Aluminum (Al) is present in the daily life of humans, and the incidence of Al contamination increased in recent years. Long-term excessive Al intake induces neuroinflammation and cognition impairment. Neuroinflammation alter density of dendritic spine, which, in turn, influence cognition function. However, it is unknown whether increased neuroinflammation is associated with altered density of dendritic spine in Al-treated rats. In the present study, AlCl3 was orally administrated to rat at 50, 150 and 450 mg/kg for 90d. We examined the effects of AlCl3 on the cognition function, density of dendritic spine in hippocampus of CA1 and DG region and the mRNA levels of IL-1β, IL-6, TNF-α, MHC II, CX3CL1 and BNDF in developing rat. These results showed exposure to AlCl3 lead to increased mRNA levels of IL-1β, IL-6, TNF-α and MCH II, decreased mRNA levels of CX3CL1 and BDNF, decreased density of dendritic spine and impaired learning and memory in developing rat. Our results suggest AlCl3 can induce neuroinflammation that may result in loss of spine, and thereby leads to learning and memory deficits.

  16. Citrate-release-mediated aluminum resistance is coupled to the inducible expression of mitochondrial citrate synthase gene in Paraserianthes falcataria.

    Science.gov (United States)

    Osawa, Hiroki; Kojima, Katsumi

    2006-05-01

    Aluminum (Al) resistance in some leguminous plants is achieved by enhanced citrate release from roots. Enhancement requires several hours for complete activation and is postulated to involve Al-responsive genes or components. We examined the mechanism of Al-induced citrate release by studying the relationship between citrate release and expression of the mitochondrial citrate synthase (mCS) gene in three leguminous trees. Root elongation in Leucaena leucocephala (Lam.) de Wit was arrested within 24 h by 30 microM Al, whereas root elongation in Paraserianthes falcataria (L.) Neilson and Acacia mangium Willd. was inhibited mangium maintained enhanced release and accumulation of citrate for at least 28 days in response to Al treatment. Aluminum increased the accumulation of mCS transcripts in P. falcataria roots, but not in L. leucocephala roots, and thus up-regulation decreased following removal of Al. Lanthanum did not alter the expression level of mCS. Aluminum increased mCS activity concomitantly with enhanced mCS gene expression in P. falcataria, whereas it did not affect mCS activity in L. leucocephala. Aluminum content in root apices of P. falcataria was increased by cycloheximide, supporting the idea that de novo synthesis of proteins is a prerequisite for Al resistance. Our findings suggest that Al-inducible expression of mCS coupled with enhanced citrate release mediates Al resistance in P. falcataria.

  17. Approach for determination of detonation performance and aluminum percentage of aluminized-based explosives by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Rezaei, Amir Hossein; Keshavarz, Mohammad Hossein; Tehrani, Masoud Kavosh; Reza Darbani, Seyyed Mohammad; Farhadian, Amir Hossein; Mousavi, Seyyed Jabbar; Mousaviazar, Ali

    2016-04-20

    Energetic materials containing aluminum powder are hazardous compounds, which have wide applications as propellants, explosives, and pyrotechnics. This work introduces a new method on the basis of the laser-induced breakdown spectroscopy technique in air and argon atmospheres to investigate determination of aluminum content and detonation performance of 1,3,5-trinitro-1,3,5-triazine (RDX)-based aluminized explosives. Plasma emission of aluminized RDX explosives are recorded where atomic lines of Al, C, H, N, and O, as well as molecular bands of AlO and CN are identified. The formation mechanism of AlO and CN molecular bands is affected by the aluminum percentage and oxygen content present in the composition and plasma. Relative intensity of the Al/O is used to determine detonation velocity and pressure of the RDX/Al samples. The released energy in the laser-induced plasma of aluminized RDX composition is related to the heat of explosion and percentage of aluminum.

  18. Immobilization of 60Co and 90Sr ions using red mud from aluminum industry

    Directory of Open Access Journals (Sweden)

    Milenković Aleksandra S.

    2014-01-01

    Full Text Available The removal of 60Co and 90Sr from the aqueous phase was tested using red mud - the fine grained residue from bauxite ore processing. This industrial waste represents a mixture of numerous minerals, mainly oxides and hydroxides of Fe, Al, Si, and Ti. Experiments were conducted as a function of contact time, pH, and pollutant concentrations. Kinetic data were well fitted with a pseudo-second order equation. The calculated rate constants and initial sorption rates indicated faster sorption of Sr2+ ions. Removal of both cations rapidly increased with the initial pH increase from 2.5 to 3.5. With the further increase of pH, Co2+ sorption was nearly constant (98%-100%, whereas Sr2+ removal remained at the same level to initial pH ~8 and gradually increased to 100% at pH 12. Equilibrium sorption data followed the Langmuir model, with the maximum sorption capacities of 0.52 mmol/g for Co2+ and 0.31 mmol/g for Sr2+. Sorbed cations exhibited high stability in distilled water. Desorption of Co2+ was also negligible in the presence of the competing Ca2+ cation, while 42%-25% of Sr2+ ions were desorbed depending on the previously sorbed amount. The results indicate that red mud is of potential significance as Co2+ and Sr2+ immobilization agent due to its high efficiency, abundance, and low-cost. [Projekat Ministarstva nauke Republike Srbije, br. 43009

  19. Axial- and radial-resolved electron density and excitation temperature of aluminum plasma induced by nanosecond laser: Effect of the ambient gas composition and pressure

    Directory of Open Access Journals (Sweden)

    Mahmoud S. Dawood

    2015-11-01

    Full Text Available The spatial variation of the characteristics of an aluminum plasma induced by a pulsed nanosecond XeCl laser is studied in this paper. The electron density and the excitation temperature are deduced from time- and space- resolved Stark broadening of an ion line and from a Boltzmann diagram, respectively. The influence of the gas pressure (from vacuum up to atmospheric pressure and compositions (argon, nitrogen and helium on these characteristics is investigated. It is observed that the highest electron density occurs near the laser spot and decreases by moving away both from the target surface and from the plume center to its edge. The electron density increases with the gas pressure, the highest values being occurred at atmospheric pressure when the ambient gas has the highest mass, i.e. in argon. The excitation temperature is determined from the Boltzmann plot of line intensities of iron impurities present in the aluminum target. The highest temperature is observed close to the laser spot location for argon at atmospheric pressure. It decreases by moving away from the target surface in the axial direction. However, no significant variation of temperature occurs along the radial direction. The differences observed between the axial and radial direction are mainly due to the different plasma kinetics in both directions.

  20. Ion channel mimetic membranes and silica nanotubes prepared from porous aluminum oxide templates

    Science.gov (United States)

    Mitchell, David Tanner

    Chapter 1 provides background information on the template synthesis of nanomaterials. The template synthesis method is examined with special attention to the use of membranes containing monodisperse cylindrical pores as templates. Several examples of the utility of template-synthesized nanomaterials are given. The production of one type of template membrane, nanopore alumina, is reviewed. Reviews of sol-gel and silane chemistry are also provided. In Chapter 2, a sol-gel template synthesis process is used to produce silica nanotubes within the pores of alumina templates. The nanotubes can be modified using a variety of chemistries, typically via a silanization process. Because the nanotubes are formed in a template, the interior and exterior surface can be modified independently. Modified nanotubes can be used for drug detoxification or as extractants for the removal of metal ions. The nanotube surface can also be biotinylated, which causes binding to avidinated surfaces. Composite microtubes of silica and various polymers are also prepared. Additionally, Au nanowires are shown to assemble with colloidal Au particles using dithiols as linkers. Chapter 3 describes the attachment of proteins onto template-synthesized silica nanotubes. The proteins are covalently linked via an aldehyde silane bridge that binds to pendant primary amino moieties on the protein. Protein-modified nanotubes function as highly specific extractants. Avidin-modified nanotubes extract biotin-coated Au nanoparticles from solution with high extraction efficiency. Immunoprotein-modified nanotubes extract the corresponding antibody from solution with high specificity. Antibody-modified nanotubes extract one enantiomer from a racemic mix. Enzymes, including drug detoxification enzymes, were also attached to the nanotubes and were shown to retain their catalytic activity. Immunoproteins on the outside of nanotubes can be used to direct nanotube binding, creating specific labeling agents. Chapter 4

  1. Study of ion beam induced depolymerization using positron annihilation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Puglisi, O. E-mail: opuglisi@dipchi.unict.it; Fragala, M.E.; Lynn, K.G.; Petkov, M.; Weber, M.; Somoza, A.; Dupasquier, A.; Quasso, F

    2001-04-01

    Ion beam induced depolymerization of polymers is a special class of ion beam induced chemical reaction which gives rise to catastrophic 'unzipping' of macromolecules with production of large amounts of the monomer, of the order of many hundreds monomer molecules per each macromolecule. The possible modification of the density at microscopic level prompted us to undertake a study of this effect utilizing positron annihilation techniques in Poly(methylmethacrylate) (PMMA) before and after bombardment with He{sup +} 300 keV ions at 200 deg. C. Preliminary results shown here indicate that before bombardment there is a reproducible dependence of nano-hole distribution on the sample history. Moreover at 200 deg. C we do not detect formation of new cavities as a consequence of the strong depolymerization that occurs under the ion beam. The possible correlation of these findings with transport properties of PMMA at temperature higher than the glass transition temperature will be discussed.

  2. Involvement of CD300a Phosphatidylserine Immunoreceptor in Aluminum Salt Adjuvant-Induced Th2 Responses.

    Science.gov (United States)

    Miki, Haruka; Nakahashi-Oda, Chigusa; Sumida, Takayuki; Shibuya, Akira

    2015-06-01

    Aluminum salt (alum) has been widely used for vaccinations as an adjuvant. Alum not only enhances immunogenicity but also induces Th2 cell immune responses. However, the mechanisms of how alum enhances Th2 cell immune responses have been controversial. In an experimental allergic airway inflammation model, in which alum in conjunction with OVA Ag was i.p. injected for immunization, we found that apoptotic cells and inflammatory dendritic cells (iDC) expressing CD300a, an inhibitory immunoreceptor for phosphatidylserine (PS), significantly increased in number in the peritoneal cavity after the immunization. In contrast, apoptotic cells and iDCs were scarcely observed in the peritoneal cavity after injection of OVA alone. In CD300a-deficient mice, eosinophil infiltration in bronchoalveolar lavage fluid, serum IgE levels, and airway hyperreactivity were significantly decreased after immunization with alum plus OVA compared with wild-type mice. In vitro, iDCs purified from CD300a-deficient mice after the immunization induced significantly less IL-4 production from OT-II naive CD4(+) T cells after coculture with OVA Ag. CD300a expressed on iDCs bound PS on apoptotic cells in the peritoneal cavity after injection of OVA plus alum. Blocking CD300a interaction with PS by injection of a neutralizing anti-CD300a Ab resulted in inhibition of the development of allergic airway inflammation. These results suggest that CD300a is involved in alum-induced Th2 skewing. Copyright © 2015 by The American Association of Immunologists, Inc.

  3. Oxidation and corrosion behavior of titanium aluminum nitride coatings by arc ion plating

    Institute of Scientific and Technical Information of China (English)

    LI Ming-sheng; FENG Chang-jie; ZHANG Zhi-feng; WANG Fu-hui

    2006-01-01

    Composite metastable TiN and Ti1-xAlxN coatings with different Al content were deposited on 1Cr11Ni2W2MoV stainless steel for aero-engine compressor blades by arc ion plating. The results show that all coatings have a B1NaCl structure and the preferred orientation changes from (111) to (220) with increasing Al content; the lattice parameter of Ti1-xAlxN decreases with the increase of Al content. The oxidation-resistance of (Ti,Al)N coatings is significantly improved owing to the formation of Al-riched oxide on the surface of the coatings. The nitride coatings can significantly improve the corrosion-resistance of 1Cr11Ni2W2MoV stainless steel under the synergistic of water vapor and NaCl, and the corrosion-resistance becomes better when the Al content increases, because not only the quick formation of thin alumina layer prevents the further corrosion but also the formation of alumina seals the pinholes or defects in the coatings, which prevents the occurrence of localized nodules-like corrosion.

  4. Characteristics of Ion Activation and Collision Induced Dissociation Using Digital Ion Trap Technology

    Science.gov (United States)

    Xu, Fuxing; Dang, Qiankun; Dai, Xinhua; Fang, Xiang; Wang, Yuanyuan; Ding, Li; Ding, Chuan-Fan

    2016-08-01

    Collision induced dissociation (CID) is one of the most established techniques for tandem mass spectrometry analysis. The CID of mass selected ion could be realized by ion resonance excitation with a digital rectangular waveform. The method is simple, and highly efficient CID result could be obtained by optimizing the experimental parameters, such as digital waveform voltage, frequency, and q value. In this work, the relationship between ion trapping waveform voltage and frequency at preselected q value, the relationship between waveform frequency and the q value at certain ion trapping voltage for optimum CID efficiency were investigated. Experiment results showed that the max CID efficiency of precursor reserpine ions can be obtained at different trapping waveform voltage and frequency when q and β are different. Based on systematic experimental analysis, the optimum experimental conditions for high CID efficiency can be calculated at any selected β or q. By using digital ion trap technology, the CID process and efficient fragmentation of parent ions can be realized by simply changing the trapping waveform amplitude, frequency, and the β values in the digital ion trap mass spectrometry. The technology and method are simple. It has potential use in ion trap mass spectrometry.

  5. Ion irradiation-induced structure damage to botanic samples using the ion transmission energy spectrum

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to study the mechanism of irradiation-induced damage ofbotanic samples caused by low energy heavy ions, transmission energy spectrum mea-surement was performed. Kidney bean slice samples 100μm in thickness were irradi-ated by 50 kev N+ ions. The irradiation beam current density was about 30μA/cm2,and the irradiation ion doses were 1×1015, 1×1016, 3×1016 and 1×1017 ions@cm-2,respectively. A target set up that could greatly reduce the incident ion current densitywas designed to achieve the damage-free measurement. The 3.2 MeV H+ transmittedion energy spectrum measurement was carried out before and after the irradiation.From the transmission ion energy spectrum, it was found that the kidney bean sliceitself was structurally inhomogeneous compared with the PET films (C10HsO4). Ourresults indicated that the average mass thickness changed little when the N+ iondose was below 3×1016 ions.cm-2, but changed obviously whcn ion dose was beyond3×1016 ions.cm-2.

  6. Nanopillar growth by focused helium ion-beam-induced deposition

    NARCIS (Netherlands)

    Chen, P.; Veldhoven, E. van; Sanford, C.A.; Salemink, H.W.M.; Maas, D.J.; Smith, D.A.; Rack, P.D.; Alkemade, P.F.A.

    2010-01-01

    A 25 keV focused helium ion beam has been used to grow PtC nanopillars on a silicon substrate by beam-induced decomposition of a (CH3) 3Pt(CPCH3) precursor gas. The ion beam diameter was about 1 nm. The observed relatively high growth rates suggest that el

  7. Ion implantation induced blistering of rutile single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Bing-Xi [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Jiao, Yang [College of Physics and Electronics, Shandong Normal University, Jinan, Shandong 250100 (China); Guan, Jing [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Wang, Lei [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China)

    2015-07-01

    The rutile single crystals were implanted by 200 keV He{sup +} ions with a series fluence and annealed at different temperatures to investigate the blistering behavior. The Rutherford backscattering spectrometry, optical microscope and X-ray diffraction were employed to characterize the implantation induced lattice damage and blistering. It was found that the blistering on rutile surface region can be realized by He{sup +} ion implantation with appropriate fluence and the following thermal annealing.

  8. Agrobacterium-mediated transformation of kabocha squash (Cucurbita moschata Duch) induced by wounding with aluminum borate whiskers.

    Science.gov (United States)

    Nanasato, Yoshihiko; Konagaya, Ken-ichi; Okuzaki, Ayako; Tsuda, Mai; Tabei, Yutaka

    2011-08-01

    An efficient genetic transformation method for kabocha squash (Cucurbita moschata Duch cv. Heiankogiku) was established by wounding cotyledonary node explants with aluminum borate whiskers prior to inoculation with Agrobacterium. Adventitious shoots were induced from only the proximal regions of the cotyledonary nodes and were most efficiently induced on Murashige-Skoog agar medium with 1 mg/L benzyladenine. Vortexing with 1% (w/v) aluminum borate whiskers significantly increased Agrobacterium infection efficiency in the proximal region of the explants. Transgenic plants were screened at the T(0) generation by sGFP fluorescence, genomic PCR, and Southern blot analyses. These transgenic plants grew normally and T(1) seeds were obtained. We confirmed stable integration of the transgene and its inheritance in T(1) generation plants by sGFP fluorescence and genomic PCR analyses. The average transgenic efficiency for producing kabocha squashes with our method was about 2.7%, a value sufficient for practical use.

  9. Anomalous deep ion-induced modification of HOPG

    Science.gov (United States)

    Andrianova, N. N.; Borisov, A. M.; Mashkova, E. S.; Sevostyanova, V. S.; Virgiliev, Yu. S.

    2013-11-01

    The temperature dependences ion-induced processes of HOPG (UPV-1T) basal plane modification under high-fluence (1018 ion/cm2) 10-30 keV Ar+ ion irradiation have been studied in temperature range from room temperature to 400 °C. The RBS has been applied to estimate the modified layer depth. The morphology changes have been studied by SEM. It has been found that at sufficiently high ion energy the modified layer depth can be ten times more then the ion projected range Rp. The two different effects of deep modification with depth >1000 nm are observed. Firstly, at the temperatures smaller then the temperature of ion-induced texture transition T channelling geometry. Secondly, at Tt ion irradiation at temperature of texture transition Tt, as the irradiation at sufficiently high T ⩾ 400 °C, does not lead to deep modification effect and the depth h of disordered layer is about Rp. There are the energy thresholds of deep modification which correspond to threshold mean values of stationary level of radiation damage - about 50 and 65 displacements per atom accordingly for deep modification at RT and at T ∼ 250 °C.

  10. L X-ray emission induced by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Pajek, M. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Banaś, D., E-mail: d.banas@ujk.edu.pl [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Braziewicz, J.; Majewska, U.; Semaniak, J. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Fijał-Kirejczyk, I. [The Institute of Atomic Energy, 05-400 Otwock-Świerk (Poland); Jaskóła, M.; Czarnacki, W.; Korman, A. [The National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Kretschmer, W. [Physikalisches Institut, Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Mukoyama, T. [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), H-4026 Debrecen (Hungary); Trautmann, D. [Institut für Physik, Universität Basel, Basel (Switzerland)

    2015-11-15

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster–Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L{sub 2}-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

  11. L X-ray emission induced by heavy ions

    Science.gov (United States)

    Pajek, M.; Banaś, D.; Braziewicz, J.; Majewska, U.; Semaniak, J.; Fijał-Kirejczyk, I.; Jaskóła, M.; Czarnacki, W.; Korman, A.; Kretschmer, W.; Mukoyama, T.; Trautmann, D.

    2015-11-01

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster-Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L2-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

  12. Hydrolysis of Aluminum Ions in Kaolinite and Oxisol Suspensions as Influenced by Organic Anions

    Institute of Scientific and Technical Information of China (English)

    XU Ren-Kou; XIAO Shuang-Cheng; LI Jiu-Yu; D. TIWARI; JI Guo-Liang

    2007-01-01

    To evaluate the role of kaolinite and variable charge soils on the hydrolytic reaction of Al, the hydrolysis of Al ions in suspensions of a kaolinite and an Oxisol influenced by organic anions was investigated using changes of pH, Al adsorption, and desorption of pre-adsorbed Al. Kaolinite and the Oxisol promoted the hydrolytic reaction of Al above a certain initial Al concentration (0.1 mmol L-1 for kaolinite and 0.3 mmol L-1 for the Oxisol). The Al hydrolysis accelerated by kaolinite and the Oxisol increased with an increase in initial concentration of Al and was observed in the range of pH from 3.7 to 4.7 for kaolinite and 3.9 to 4.9 for the Oxisol. The acceleration of Al hydrolysis also increased with the increase of solution pH, reached a maximum value at pH 4.5, and then decreased sharply. Al hydrolysis was promoted mainly through selective adsorption for hydroxy-Al. Soil free iron oxides compensated a portion of the soil negative charge or masked some soil surface negative sites leading to a decrease in Al adsorption, which retarded acceleration to some extent. For the Oxisol organic anions increased the proportion of adsorbed Al3+ in total adsorbed Al with the increase in soil negative surface charge and eliminated or reduced the acceleration of Al hydrolysis. Different organic anions inhibited the hydrolysis of Al in the order:citrate > oxalate > acetate (under initial pH of 4.5). The formation of Al-organic complexes in solution also inhibited the hydrolysis of Al.

  13. Advanced ion beam analysis of materials using ion-induced fast electron

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Hiroshi; Tanabe, Atsushi; Ishihara, Toyoyuki [Tsukuba Univ., Ibaraki (Japan)] [and others

    1997-03-01

    Recent progress in the study of high-energy shadowing effect using ion-induced electron spectroscopy is reported with emphasis on a possibility of determination of local electronic structure in solids, which has been a difficult problem to approach with other experimental techniques. We demonstrate real-space determination of covalent-bond electron distribution in Si crystal. The analysis technique may provide a new field of ion beam analysis of solids. (author)

  14. Ion beam induced charge characterisation of a silicon microdosimeter using a heavy ion microprobe

    Science.gov (United States)

    Cornelius, Iwan; Siegele, Rainer; Rosenfeld, Anatoly B.; Cohen, David D.

    2002-05-01

    An ion beam induced charge (IBIC) facility has been added to the existing capabilities of the ANSTO heavy ion microprobe and the results of the first measurements are presented. Silicon on insulator (SOI) diode arrays with microscopic junction sizes have recently been proposed as microdosimeters for hadron therapy. A 20 MeV carbon beam was used to perform IBIC imaging of a 10 μm thick SOI device.

  15. Ultrafast laser induced periodic sub-wavelength aluminum surface structures and nanoparticles in air and liquids

    Energy Technology Data Exchange (ETDEWEB)

    Kuladeep, Rajamudili; Dar, Mudasir H.; Rao, D. Narayana, E-mail: dnrsp@uohyd.ac.in, E-mail: dnr-laserlab@yahoo.com [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Deepak, K. L. N. [Department of Physics and Center for Research in Photonics, University of Ottawa, 150 Louis Pasteur, Ottawa K1N6N5, Ontario (Canada)

    2014-09-21

    In this communication, we demonstrate the generation of laser-induced periodic sub-wavelength surface structures (LIPSS) or ripples on a bulk aluminum (Al) and Al nanoparticles (NPs) by femtosecond (fs) laser direct writing technique. Laser irradiation was performed on Al surface at normal incidence in air and by immersing in ethanol (C₂H₅OH) and water (H₂O) using linearly polarized Ti:sapphire fs laser pulses of ~110 fs pulse duration and ~800 nm wavelength. Field emission scanning electron microscope is utilized for imaging surface morphology of laser written structures and it reveals that the spatial periodicity as well as the surface morphology of the LIPSS depends on the surrounding dielectric medium and also on the various laser irradiation parameters. The observed LIPSS have been classified as low spatial frequency LIPSS which are perpendicularly oriented to the laser polarization with a periodicity from 460 to 620 nm and high spatial frequency LIPSS which spectacles a periodicity less than 100 nm with the orientation parallel to the polarization of the incident laser beam. Fabricated colloidal solutions, which contain the Al NPs, were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). TEM results reveal the formation of internal cavities in Al NPs both in ethanol and water. Formation mechanism of LIPSS and cavities inside the nanoparticles are discussed in detail.

  16. High-power laser shock-induced dynamic fracture of aluminum and microscopic observation of samples

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2015-01-01

    Full Text Available High-power laser induced shocks generated by “ShenGuang II” laser facility has been used to study spall fracture of polycrystalline aluminum at strain rates more than 106/s. The free surface velocity histories of shock-loaded samples, 150 μm thick and with initial temperature from 293 K to 873 K, have been recorded using velocity interferometer system for any reflector (VISAR. From the free surface velocity profile, spall strength and yield stress are calculated, it demonstrates that spall strength will decline and yield strength increase with initial temperature. The loaded samples are recovered to obtain samples' section and free surface metallographic pictures through Laser Scanning Confocal Microscopy. It is found that there are more micro-voids and more opportunity to appear bigger voids near the spall plane and the grain size increases with temperature slowly but smoothly except the sharply change at 893 K (near melting point. Besides, the fracture mechanisms change from mainly intergranular fracture to transgranular fracture with the increase of initial temperature.

  17. Peri-nuclear clustering of mitochondria is triggered during aluminum maltolate induced apoptosis.

    Science.gov (United States)

    Dewitt, David A; Hurd, Jennifer A; Fox, Nena; Townsend, Brigitte E; Griffioen, Kathleen J S; Ghribi, Othman; Savory, John

    2006-07-01

    Synapse loss and neuronal death are key features of Alzheimer's disease pathology. Disrupted axonal transport of mitochondria is a potential mechanism that could contribute to both. As the major producer of ATP in the cell, transport of mitochondria to the synapse is required for synapse maintenance. However, mitochondria also play an important role in the regulation of apoptosis. Investigation of aluminum (Al) maltolate induced apoptosis in human NT2 cells led us to explore the relationship between apoptosis related changes and the disruption of mitochondrial transport. Similar to that observed with tau over expression, NT2 cells exhibit peri-nuclear clustering of mitochondria following treatment with Al maltolate. Neuritic processes largely lacked mitochondria, except in axonal swellings. Similar, but more rapid results were observed following staurosporine administration, indicating that the clustering effect was not specific to Al maltolate. Organelle clustering and transport disruption preceded apoptosis. Incubation with the caspase inhibitor zVAD-FMK effectively blocked apoptosis, however failed to prevent organelle clustering. Thus, transport disruption is associated with the initiation, but not necessarily the completion of apoptosis. These results, together with observed transport defects and apoptosis related changes in Alzheimer disease brain suggest that mitochondrial transport disruption may play a significant role in synapse loss and thus the pathogenesis or Alzheimer's disease.

  18. Aluminum Trichloride Induces Hypertension and Disturbs the Function of Erythrocyte Membrane in Male Rats.

    Science.gov (United States)

    Zhang, Qiuyue; Cao, Zheng; Sun, Xudong; Zuang, Cuicui; Huang, Wanyue; Li, Yanfei

    2016-05-01

    Aluminum (Al) is the most abundant metal in the earth's crust. Al accumulates in erythrocyte and causes toxicity on erythrocyte membrane. The dysfunction of erythrocyte membrane is a potential risk to hypertension. The high Al content in plasma was associated with hypertension. To investigate the effect of AlCl3 on blood pressure and the function of erythrocyte membrane, the rats were intragastrically exposed to 0, 64(1/20 LD50), 128(1/10 LD50), and 256(1/5 LD50) mg/kg body weight AlCl3 in double distilled water for 120 days, respectively. Then, we determined the systolic and mean arterial blood pressures of rats, the osmotic fragility, the percentage of membrane proteins, the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-pX), and malondialdehyde (MDA) content of the erythrocyte membrane in this experiment. The results showed that AlCl3 elevated the systolic and mean arterial blood pressure of rats, increased the osmotic fragility, decreased the percentage of membrane protein, inhibited the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, CAT, SOD and GSH-pX, and increased the MDA content of erythrocyte membrane. These results indicate that AlCl3 may induce hypertension by disturbing the function of erythrocyte membrane.

  19. Ultrafast laser induced periodic sub-wavelength aluminum surface structures and nanoparticles in air and liquids

    Science.gov (United States)

    Kuladeep, Rajamudili; Dar, Mudasir H.; Deepak, K. L. N.; Rao, D. Narayana

    2014-09-01

    In this communication, we demonstrate the generation of laser-induced periodic sub-wavelength surface structures (LIPSS) or ripples on a bulk aluminum (Al) and Al nanoparticles (NPs) by femtosecond (fs) laser direct writing technique. Laser irradiation was performed on Al surface at normal incidence in air and by immersing in ethanol (C2H5OH) and water (H2O) using linearly polarized Ti:sapphire fs laser pulses of ˜110 fs pulse duration and ˜800 nm wavelength. Field emission scanning electron microscope is utilized for imaging surface morphology of laser written structures and it reveals that the spatial periodicity as well as the surface morphology of the LIPSS depends on the surrounding dielectric medium and also on the various laser irradiation parameters. The observed LIPSS have been classified as low spatial frequency LIPSS which are perpendicularly oriented to the laser polarization with a periodicity from 460 to 620 nm and high spatial frequency LIPSS which spectacles a periodicity less than 100 nm with the orientation parallel to the polarization of the incident laser beam. Fabricated colloidal solutions, which contain the Al NPs, were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). TEM results reveal the formation of internal cavities in Al NPs both in ethanol and water. Formation mechanism of LIPSS and cavities inside the nanoparticles are discussed in detail.

  20. Pretreatment with H2O2 Alleviates Aluminum-induced Oxidative Stress in Wheat Seedlings

    Institute of Scientific and Technical Information of China (English)

    Fang Jie Xu; Chong Wei Jin; Wen Jing Liu; Yong Song Zhang; Xian Yong Lin

    2011-01-01

    Hydrogen peroxide(H2O2)is a key reactive oxygen species(ROS)in signal transduction pathways Ieading to activation of plant defenses against biotic and abiotic stresses.In this study,we investigated the effects of H2O2 pretreatment on aluminum (Al)induced antioxidant responses in root tips of two wheat(Triticum aestivum L.)genotypes,Yangmai-5(Al-sensitive)and Jian-864(Al-tolerant).Al increased and root elongation inhibition in Yangmai-5 than in Jian-864.However,H2O2 pretreatment alleviated Alinduced deleterious effects in both genotypes.Under Al stress,H2O2 pretreatment increased the activities of superoxide dismutase,catalase,peroxidase,ascorbate peroxidase and monodehydroascorbate reductase,glutathione reductase and giutathione peroxidase as well as the levels of ascorbate and glutathione more significantly in Yangmai-5 than in Jian-864.Furthermore,H2O2 pretreatment also increased the total antioxidant capacity evaluated as the 2,2-diphenyl-1-picrylhydrazyl-radical scavenging activity and the ferric reducing/antioxidant power more significantly in Yangmai-5 than in Jian-864.Therefore,we conclude that H2O2 pretreatment improves wheat Al acclimation during subsequent Al exposure by enhancing the antioxidant defense capacity,which prevents ROS accumulation,and that the enhancement is greater in the Al-sensitive genotype than in the Al-tolerant genotype.

  1. Quantum explanation for time-phase relations in radiation of the plasma induced by laser ablating aluminum

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    According to time distribution of Al Ⅰ396.15 nm emission in the plasma induced by laser ablating Aluminum, based on quantum mechanics, we have suggested a hypothesis of transient steady state of atom, which could give our experimental results overall and reasonable explanation in quantum. We suggested that there should be a certain atomic state between ground and excited state of Aluminum atom, so called transient steady state. The transient steady state was that aluminum atom had already absorbed a certain photon, but the valence electron had not transited to external orbit. That is to say, aluminum atom had not transited into excited state, but changed into a certain state called transient steady state between ground and excited state. Seen from the point of atomic energy level, the transient steady state is identical to the level of excited state. The transient steady state was one of the most important models storing energy. The hypothesis could roundly and reasonably explain our experimental results.

  2. Effect of deposition parameters on mechanical properties of TiN films coated on 2A12 aluminum alloys by arc ion plating (AIP)

    Institute of Scientific and Technical Information of China (English)

    AWAD Samir Hamid; QIAN Han-cheng

    2005-01-01

    TiN films were deposited on 2A12 aluminum alloy by arc ion plating (AIP). The Vickers hardness of the films deposited at different bias voltages and different nitrogen gas pressures, and that of the substrate were measured. The surface roughness of the TiN films diposited at -30 V and -80 V respectively and at different nitrogen gas pressure was measured also. The mass loss of TiN films deposited at 0 V, -30 V and -80 V respectively were analyzed in dry sand rubber wheel abrasive wear tests and wet ones in comparison with uncoated Al alloy and austenitic stainless steel (AISI 316L). It is revealed that the highest hardness of the TiN film is obtained at a bias voltage of -30 V and a N2 gas pressure of 0.5 Pa. The surface roughness of the film is larger at -80 V than that at -30 V and reduces as the increase of the N2 gas pressure. The mass loss of TiN-film coated 2A12 aluminum alloy is remarkably less than that of uncoated Al alloy and also that of AISI 316L, which indicates that the abrasive wear rate is greatly reduced by the application of TiN coating. TiN coating deposited by arc ion plating (AIP) technique on aluminum alloy can be a potential coating for machine parts requiring preciseness and lightness.

  3. Melt quality induced failure of electrical conductor (EC grade aluminum wires

    Directory of Open Access Journals (Sweden)

    Khaliq A.

    2017-01-01

    Full Text Available The failure of electrical conductor grade (EC aluminum during wire drawing process was investigated. The fractured aluminum wires were subjected to Scanning Electron Microscopy (SEM and Energy Dispersive X-ray (EDX analyses for an initial examination. Thermodynamic analyses of molten aluminum interaction with refractories was also carried out using FactSage at 710°C to predict the stable phases. The SEM/EDX analyses has revealed the inclusions in aluminum matrix. The typical inclusions observed were Al2O3, Al3C4 (Al-Carbide and oxides of refractories elements (Al, Mg, Si and O that have particle size ranging up to 5 μm. The transition metal boride particles were not identified during SEM/EDX analyses these might be too fine to be detected with this microscope. The overall investigation suggested that the possible cause of this failure is second phase particles presence as inclusions in the aluminum matrix, and this was associated with the poor quality of melt. During wire drawing process, these inclusions were pulled out of the aluminum matrix by the wiredrawing forces to produce micro-voids which led to ductile tearing and final fracture of wires. It was recommended to use ceramic foam filters to segregate inclusions from molten aluminum.

  4. Aspects of aluminum toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, C.D.; Savory, J.; Wills, M.R. (Univ. of Virginia Health Sciences Center, Charlottesville (USA))

    1990-06-01

    Aluminum is the most abundant metal in the earth's crust. The widespread occurrence of aluminum, both in the environment and in foodstuffs, makes it virtually impossible for man to avoid exposure to this metal ion. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago, but was dismissed as a toxic agent as recently as 15 years ago. The accumulation of aluminum, in some patients with chronic renal failure, is associated with the development of toxic phenomena; dialysis encephalopathy, osteomalacic dialysis osteodystrophy, and an anemia. Aluminum accumulation also occurs in patients who are not on dialysis, predominantly infants and children with immature or impaired renal function. Aluminum has also been implicated as a toxic agent in the etiology of Alzheimer's disease, Guamiam amyotrophic lateral sclerosis, and parkinsonism-dementia. 119 references.

  5. Simulation of induced radioactivity for Heavy Ion Medical Machine

    CERN Document Server

    Jun-Kui, Xu; Wu-Yuan, Li; Wang, Mao; Jia-Wen, Xia; Xi-Meng, Chen; Wei-Wei, Yan; Chong, Xu

    2013-01-01

    For radiation protection and environmental impact assessment purpose, the radioactivity induced by carbon ion of Heavy Ion Medical Machine (HIMM) was studied. Radionuclides in accelerator component, cooling water and air at target area which are induced from primary beam and secondary particles are simulated by FLUKA Monte Carlo code. It is found that radioactivity in cooling water and air is not very important at the required beam intensity and energy which is needed for treatment, radionuclides in accelerator component may cause some problem for maintenance work, suitable cooling time is needed after the machine are shut down.

  6. Involvement of pentraxin-3 in anti-neutrophil cytoplasmic antibody production induced by aluminum salt adjuvant.

    Science.gov (United States)

    Nagai, Kei; Aratani, Yasuaki; Shibuya, Akira; Yamagata, Kunihiro

    2017-01-01

    Pentraxin 3 (PTX3) is a multifunctional soluble factor. PTX3 can be involved in the regulation of vasculitis and is expressed in the cytoplasm of neutrophils. As anti-neutrophil cytoplasmic antibody (ANCA) is recognised as a cause of vasculitis, we aimed to discover the role of PTX3 in ANCA production in vivo. To this end, we used aluminum salt (alum), which induces neutrophil extracellular traps, as an adjuvant for producing anti-myeloperoxidase-ANCA (MPO-ANCA). Specifically, we intraperitoneally injected alum and recombinant MPO (rMPO) into MPO-deficient mice and then measured the concentration of anti-MPO IgG in their blood. To show the involvement of extracellular PTX3 in this model, we assessed PTX3 protein content and host double-stranded DNA levels in the mice's peritoneal fluid after alum injection. In addition, we simultaneously administered recombinant PTX3, rMPO and alum to MPO-deficient mice to assess the function of PTX3 in producing anti-MPO IgG in vivo. Anti-MPO IgG was produced by the alum + rMPO immunisation model in MPO-deficient but not wildtype mice. Injection of alum induced extracellular PTX3 as well as double-stranded DNA and dead cells in MPO-deficient mice. Simultaneous injection of recombinant PTX3 with rMPO and alum attenuated the production of anti-MPO IgG in MPO-deficient mice. Our current findings provide evidence that PTX3 attenuates the production of murine MPO-ANCA.

  7. Single ion induced surface nanostructures: a comparison between slow highly charged and swift heavy ions.

    Science.gov (United States)

    Aumayr, Friedrich; Facsko, Stefan; El-Said, Ayman S; Trautmann, Christina; Schleberger, Marika

    2011-10-05

    This topical review focuses on recent advances in the understanding of the formation of surface nanostructures, an intriguing phenomenon in ion-surface interaction due to the impact of individual ions. In many solid targets, swift heavy ions produce narrow cylindrical tracks accompanied by the formation of a surface nanostructure. More recently, a similar nanometric surface effect has been revealed for the impact of individual, very slow but highly charged ions. While swift ions transfer their large kinetic energy to the target via ionization and electronic excitation processes (electronic stopping), slow highly charged ions produce surface structures due to potential energy deposited at the top surface layers. Despite the differences in primary excitation, the similarity between the nanostructures is striking and strongly points to a common mechanism related to the energy transfer from the electronic to the lattice system of the target. A comparison of surface structures induced by swift heavy ions and slow highly charged ions provides a valuable insight to better understand the formation mechanisms.

  8. Ion beam induced optical and surface modification in plasmonic nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Udai B., E-mail: udaibhansingh123@gmail.com; Gautam, Subodh K.; Kumar, Sunil; Hooda, Sonu; Ojha, Sunil; Singh, Fouran

    2016-07-15

    In present work, ion irradiation induced nanostructuring has been exploited as an efficient and effective tool for synthesis of coupled plasmonics nanostructures by using 1.2 MeV Xe ions on Au/ZnO/Au system deposited on glass substrate. The results are correlated on the basis of their optical absorption, surface morphologies and enhanced sensitivity of evolved phonon modes by using UV Visible spectroscopy, scanning electron microscopy (SEM), and Raman spectroscopy (RS), respectively. Optical absorbance spectra of plasmonic nanostructures (NSs) show a decrease in band gap, which may be ascribed to the formation of defects with ion irradiation. The surface morphology reveals the formation of percolated NSs upon ion irradiation and Rutherford backscattering spectrometry (RBS) study clearly shows the formation of multilayer system. Furthermore, RS measurements on samples are studied to understand the enhanced sensitivity of ion irradiation induced phonon mode at 573 cm{sup −1} along with other modes. As compared to pristine sample, a stronger and pronounced evolution of these phonon modes is observed with further ion irradiation, which indicates localized surface plasmon results with enhanced intensity of phonon modes of Zinc oxide (ZnO) material. Thus, such plasmonic NSs can be used as surface enhanced Raman scattering (SERS) substrates.

  9. Direct Observation of Lattice Aluminum Environments in Li Ion Cathodes LiNi1-y-zCoyAlzO2 and Al-Doped LiNixMnyCozO2 via (27)Al MAS NMR Spectroscopy.

    Science.gov (United States)

    Dogan, Fulya; Vaughey, John T; Iddir, Hakim; Key, Baris

    2016-07-06

    Direct observations of local lattice aluminum environments have been a major challenge for aluminum-bearing Li ion battery materials, such as LiNi1-y-zCoyAlzO2 (NCA) and aluminum-doped LiNixMnyCozO2 (NMC). (27)Al magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy is the only structural probe currently available that can qualitatively and quantitatively characterize lattice and nonlattice (i.e., surface, coatings, segregation, secondary phase etc.) aluminum coordination and provide information that helps discern its effect in the lattice. In the present study, we use NMR to gain new insights into transition metal (TM)-O-Al coordination and evolution of lattice aluminum sites upon cycling. With the aid of first-principles DFT calculations, we show direct evidence of lattice Al sites, nonpreferential Ni/Co-O-Al ordering in NCA, and the lack of bulk lattice aluminum in aluminum-"doped" NMC. Aluminum coordination of the paramagnetic (lattice) and diamagnetic (nonlattice) nature is investigated for Al-doped NMC and NCA. For the latter, the evolution of the lattice site(s) upon cycling is also studied. A clear reordering of lattice aluminum environments due to nickel migration is observed in NCA upon extended cycling.

  10. Heavy-ion radiation induced bystander effect in mice

    Science.gov (United States)

    Liang, Shujian; Sun, Yeqing; Zhang, Meng; Wang, Wei; Cui, Changna

    2012-07-01

    Radiation-induced bystander effect is defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, Low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic, metabolomics and proteomics play significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male mice head were exposed to 2000mGy dose of 12C heavy-ion radiation and the distant organ liver was detected on 1h, 6h, 12h and 24h after radiation, respectively. MSAP was used to monitor the level of polymorphic DNA methylation changes. The results show that heavy-ion irradiate mouse head can induce liver DNA methylation changes significantly. The percent of DNA methylation changes are time-dependent and highest at 6h after radiation. We also prove that the hypo-methylation changes on 1h and 6h after irradiation. But the expression level of DNA methyltransferase DNMT3a is not changed. UPLC/Synapt HDMS G2 was employed to detect the proteomics of bystander liver 1h after irradiation. 64 proteins are found significantly different between treatment and control group. GO process show that six of 64 which were unique in irradiation group are associated with apoptosis and DNA damage response. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo.

  11. Characteristics of Ions Emitted from Laser-Induced Silver Plasma

    Institute of Scientific and Technical Information of China (English)

    M. S. RAFIQUE; M. KHALEEQ-UR-RAHMAN; Shakoor MUNAZZA; K. A. BHATTI

    2008-01-01

    In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd:YAG laser, with a wavelength of 1064 nm, a pulsed width of 9~14 ns, a power of 1.1 MW and energy of 10 mJ, on silver target in vacuum (10'-3> Torr = 1.3332 Pa). The charac-teristics of ion streams were investigated by CR-39 detectors located at angles of 0°, 30°, 60° and 90° with respect to normal of the target. The distance between the silver target and each detector was 11 cm. The energy of silver ions was found ranging from 1.5 eV to 1.06E4 eV. There was a high concentration of ions with low energy as compared to those with high energy, showing the energy distribution amongst the ions. The flux of ions was maximum in the axial direction which was decreasing with the angle increase with respect to normal of the target, and finally became minimum in the radial direction. Hence the silver ions have shown anisotropic behaviour.

  12. Ion beam induced luminescence characterisation of CVD diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A.; Gonon, P.; Jamieson, D.N. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    The characterisation of the band structure properties of materials and devices by ion microprobe techniques has been made possible at the Melbourne MeV ion microprobe facility with the development of Ion Beam Induced Luminescence (IBIL). A number of diamond films grown by Microwave Plasma Chemical Vapour Deposition (MPCVD) on silicon substrates are analysed. A preliminary study of the luminescence properties of these samples has revealed information not previously obtainable via traditional microprobe techniques. The optical effects of incorporating dopants during the deposition process is determined using IBIL. The presence of trace element impurities introduced during growth is examined by Particle Induced X-ray Emission (PIXE), and a measurement of the film thickness is made using Rutherford Backscattering Spectrometry (RBS). 7 refs., 2 figs.

  13. Proximity effect in ion-beam-induced deposition of nanopillars

    NARCIS (Netherlands)

    Chen, P.; Salemink, H.W.M.; Alkemade, P.F.A.

    2009-01-01

    Ion-beam-induced deposition (IBID) is a powerful technique for prototyping three-dimensional nanostructures. To study its capability for this purpose, the authors investigate the proximity effect in IBID of nanopillars. In particular, the changes in shape and dimension of pillars are studied when a

  14. Deuterium ion irradiation induced blister formation and destruction

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jaemin; Kim, Nam-Kyun; Kim, Hyun-Su; Jin, Younggil; Roh, Ki-Baek; Kim, Gon-Ho, E-mail: ghkim@snu.ac.kr

    2016-11-01

    Highlights: • The areal number density of blisters on the grain with (1 1 1) plane orientation increased with increasing ion fluence. • No more blisters were created above the temperature about 900 K due to high thermal mobility of ions and inactivity of traps. • The destruction of blister at the boundary induced by sputtering is proposed. • The blisters were destructed at the position about the boundary by high sputtering yield of oblique incident ions and thin thickness due to plastic deformation at the boundary. - Abstract: The blisters formation and destruction induced by the deuterium ions on a polycrystalline tungsten were investigated with varying irradiation deuterium ion fluence from 3.04 × 10{sup 23} to 1.84 × 10{sup 25} D m{sup −2} s{sup −1} and an fixed irradiated ion energy of 100 eV in an electron cyclotron resonance plasma source, which was similar to the far-scrape off layer region in the nuclear fusion reactors. Target temperature was monitored during the irradiation. Most of blisters formed easily on the grain with (1 1 1) plane orientation which had about 250 nm in diameter. In addition, the areal number density of blisters increased with increasing the ion fluence under the surface temperature reaching to about 900 K. When the fluence exceeded 4.6 × 10{sup 24} D m{sup −2}, the areal number density of the blister decreased. It could be explained that the destruction of the blister was initiated by erosion at the boundary region where the thickness of blister lid was thin and the sputtering yield was high by oblique incident ions, resulting in remaining the lid open, e.g., un-eroded center dome. It is possible to work as a tungsten dust formation from the plasma facing divertor material at far-SOL region of fusion reactor.

  15. Aluminum-induced changes in properties and fouling propensity of DOM solutions revealed by UV-vis absorbance spectral parameters.

    Science.gov (United States)

    Zhou, Minghao; Meng, Fangang

    2016-04-15

    The integration of pre-coagulation with ultrafiltration (UF) is expected to not only reduce membrane fouling but also improve natural organic matter (NOM) removal. However, it is difficult to determine the proper coagulant dosage for different water qualities. The objective of this study was to probe the potential of UV-vis spectroscopic analysis to reveal the coagulant-induced changes in the fouling potentials of dissolved organic matter (DOM) and to determine the optimal coagulant dosage. The Zeta potentials (ZPs) and average particle size of the four DOM solutions (Aldrich humic acid (AHA), AHA-sodium alginate (SA), AHA-bovine serum albumin (BSA) and AHA-dextran (DEX)) coagulated with aluminum chloride (AlCl3) were measured. Results showed that increasing the aluminum coagulant dosage induced the aggregation of DOM. Meanwhile, the addition of aluminum coagulant resulted in an increase in DSlope(325-375) (the slope of the log-transformed absorbance spectra from 325 to 375 nm) and a decrease in S(275-295) (the slope of the log-transformed absorption coefficient from 275 to 295 nm) and SR (the ratio of Slope(275-295) and Slope(350-400)). The variations of these spectral parameters (i.e., DSlope(325-375), S(275-295) and SR) correlated well with the aluminum-caused changes in ZPs and average particle size. This implies that spectral parameters have the potential to indicate DOM aggregation. In addition, good correlations of spectral parameters and membrane fouling behaviors (i.e., unified membrane fouling index (UMFI)) suggest that the changes in DSlope(325-375), S(275-295) and SR were indicative of the aluminum-caused alterations of fouling potentials of all DOM solutions. Interestingly, the optimal dosage of aluminum (40 μM for AHA, AHA-BSA, and AHA-DEX) was obtained based on the relation between spectral parameters and fouling behaviors. Overall, the spectroscopic analysis, particularly for the utilization of spectral parameters, provided a convenient approach

  16. Influence of surrounding gas, composition and pressure on plasma plume dynamics of nanosecond pulsed laser-induced aluminum plasmas

    Directory of Open Access Journals (Sweden)

    Mahmoud S. Dawood

    2015-10-01

    Full Text Available In this article, we present a comprehensive study of the plume dynamics of plasmas generated by laser ablation of an aluminum target. The effect of both ambient gas composition (helium, nitrogen or argon and pressure (from ∼5 × 10−7 Torr up to atmosphere is studied. The time- and space- resolved observation of the plasma plume are performed from spectrally integrated images using an intensified Charge Coupled Device (iCCD camera. The iCCD images show that the ambient gas does not significantly influence the plume as long as the gas pressure is lower than 20 Torr and the time delay below 300 ns. However, for pressures higher than 20 Torr, the effect of the ambient gas becomes important, the shortest plasma plume length being observed when the gas mass species is highest. On the other hand, space- and time- resolved emission spectroscopy of aluminum ions at λ = 281.6 nm are used to determine the Time-Of-Flight (TOF profiles. The effect of the ambient gas on the TOF profiles and therefore on the propagation velocity of Al ions is discussed. A correlation between the plasma plume expansion velocity deduced from the iCCD images and that estimated from the TOF profiles is presented. The observed differences are attributed mainly to the different physical mechanisms governing the two diagnostic techniques.

  17. Kinetic model of stimulated emission created by resonance pumping of aluminum laser-induced plasma

    Science.gov (United States)

    Gornushkin, I. B.; Kazakov, A. Ya.

    2017-06-01

    Stimulated emission observed experimentally in an aluminum laser induced plasma is modeled via a kinetic approach. The simulated emission at several cascade transitions is created by a pump laser guided through the plasma at several microseconds after its creation and tuned in resonance with the strong 3s23p-3s24s transition at 266 nm. A two-dimensional space-time collisional radiative plasma model explains the creation of the population inversion and lasing at wavelengths of 2100 n m and 396.1 nm. The population inversion for lasing at 2100 n m is created by depopulation of the ground 3s23p state and population of the 3s25s state via the absorption of the resonant radiation at 266 nm. The population inversion for lasing at 396.1 nm occurs during the laser pulse via the decay of the population of the pumped 3s25s state to the excited 3s24s state via cascade transitions driven optically and by collisions. In particular, efficient are the mixing transitions between neighboring states separated by small gaps on the order of k T at plasma temperatures of 5000-10 000 K. The model predicts that the population inversion and corresponding gain may reach high values even at very moderate pump energy of several μJ per pulse. The efficiency of lasing at 2100 n m and 396.1 nm is estimated to be ˜3% and 0.05%, correspondingly with respect to the pump laser intensity. The gain for lasing at 396.1 nm can reach as high as ˜40 cm-1. The polarization effect that the pump radiation at 266 nm imposes on the stimulated emission at 396.1 nm is discussed. The calculated results are favorably compared to experimental data.

  18. The metal transporter SMF-3/DMT-1 mediates aluminum-induced dopamine neuron degeneration.

    Science.gov (United States)

    VanDuyn, Natalia; Settivari, Raja; LeVora, Jennifer; Zhou, Shaoyu; Unrine, Jason; Nass, Richard

    2013-01-01

    Aluminum (Al(3+)) is the most prevalent metal in the earth's crust and is a known human neurotoxicant. Al(3+) has been shown to accumulate in the substantia nigra of patients with Parkinson's disease (PD), and epidemiological studies suggest correlations between Al(3+) exposure and the propensity to develop both PD and the amyloid plaque-associated disorder Alzheimer's disease (AD). Although Al(3+) exposures have been associated with the development of the most common neurodegenerative disorders, the molecular mechanism involved in Al(3+) transport in neurons and subsequent cellular death has remained elusive. In this study, we show that a brief exposure to Al(3+) decreases mitochondrial membrane potential and cellular ATP levels, and confers dopamine (DA) neuron degeneration in the genetically tractable nematode Caenorhabditis elegans (C. elegans). Al(3+) exposure also exacerbates DA neuronal death conferred by the human PD-associated protein α-synuclein. DA neurodegeneration is dependent on SMF-3, a homologue to the human divalent metal transporter (DMT-1), as a functional null mutation partially inhibits the cell death. We also show that SMF-3 is expressed in DA neurons, Al(3+) exposure results in a significant decrease in protein levels, and the neurodegeneration is partially dependent on the PD-associated transcription factor Nrf2/SKN-1 and caspase Apaf1/CED-4. Furthermore, we provide evidence that the deletion of SMF-3 confers Al(3+) resistance due to sequestration of Al(3+) into an intracellular compartment. This study describes a novel model for Al(3+)-induced DA neurodegeneration and provides the first molecular evidence of an animal Al(3+) transporter.

  19. Formation Mechanism of Micropores on the Surface of Pure Aluminum Induced by High-Current Pulsed Electron Beam Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZOU Yang; CAI Jie; WAN Ming-Zhen; LV Peng; GUAN Qing-Feng

    2011-01-01

    The mechanism of micropores formed on the surface of polycrystalline pure aluminum under high-current pulsed electron beam (HCPEB) irradiation is explained. It is discovered that dispersed micropores with sizes of 0.1-1μm on the irradiated surface of pure aluminum can be successfully fabricated after HCPEB irradiation. The dominant formation mechanism of the surface micropores should be attributed to the formation of supersaturation vacancies within the near surface during the HCPEB irradiation and the migration of vacancies along gra,in boundaries and/or dislocations towards the irradiated surface. It is expected that the HCPEB technique will become a new method for the rapid synthesis of surface porous materials.%The mechanism of micropores formed on the surface of polycrystalline pure aluminum under high-current pulsed electron beam (HCPEB) irradiation is explained.It is discovered that dispersed micropores with sizes of 0.1-1μm on the irradiated surface of pure aluminum can be successfully fabricated after HCPEB irradiation.The dominant formation mechanism of the surface micropores should be attributed to the formation of supersaturation vacancies within the near surface during the HCPEB irradiation and the migration of vacancies along grain boundaries and/or dislocations towards the irradiated surface.It is expected that the HCPEB technique will become a new method for the rapid synthesis of surface porous materials.High-current pulsed electron beams (HCPEBs)have attracted much attention in the field of material surface modification.[1-7] During the transient bombardment process a high energy (108-109 W·cm-2) is deposited only in a very thin layer (less than tens of micrometers) within a very short time (a few microseconds) and thereby causes ultrafast heating and cooling on the irradiated surface of materials.The dynamic stress fields induced in these processes can induce intense deformation on the material surface.

  20. Influence of Orientation and Radiative Heat Transfer on Aluminum Foams in Buoyancy-Induced Convection

    Directory of Open Access Journals (Sweden)

    Marijn Billiet

    2015-10-01

    Full Text Available Two differently-produced open-cell aluminum foams were compared to a commercially available finned heat sink. Further, an aluminum plate and block were tested as a reference. All heat sinks have the same base plate dimensions of four by six inches. The first foam was made by investment casting of a polyurethane preform and has a porosity of 0.946 and a pore density of 10 pores per linear inch. The second foam is manufactured by casting over a solvable core and has a porosity of 0.85 and a pore density of 2.5 pores per linear inch. The effects of orientation and radiative heat transfer are experimentally investigated. The heat sinks are tested in a vertical and horizontal orientation. The effect of radiative heat transfer is investigated by comparing a painted/anodized heat sink with an untreated one. The heat flux through the heat sink for a certain temperature difference between the environment and the heat sink’s base plate is used as the performance indicator. For temperature differences larger than 30 °C, the finned heat sink outperforms the in-house-made aluminum foam heat sink on average by 17%. Furthermore, the in-house-made aluminum foam dissipates on average 12% less heat than the other aluminum foam for a temperature difference larger than 40 °C. By painting/anodizing the heat sinks, the heat transfer rate increased on average by 10% to 50%. Finally, the thermal performance of the horizontal in-house-made aluminum foam heat sink is up to 18% larger than the one of the vertical aluminum foam heat sink.

  1. Signal transduction events in aluminum-induced cell death in tomato suspension cells.

    Science.gov (United States)

    Yakimova, Elena T; Kapchina-Toteva, Veneta M; Woltering, Ernst J

    2007-06-01

    In this study, some of the signal transduction events involved in AlCl(3)-induced cell death in tomato (Lycopersicon esculentum Mill.) suspension cells were elucidated. Cells treated with 100 microM AlCl(3) showed typical features of programmed cell death (PCD) such as nuclear and cytoplasmic condensation. Cell death was effectively inhibited by protease and human caspase inhibitors indicating a cell death execution mechanism with similarities to animal apoptosis. Cell death was suppressed by application of antoxidants and by inhibitors of phospholipase C (PLC), phospholipase D (PLD) and ethylene signalling pathways. The results suggest that low concentrations of heavy metal ions stimulate both PLC and PLD signalling pathways leading to the production of reactive oxygen species (ROS) and subsequent cell death executed by caspase-like proteases.

  2. Ion induced spinodal dewetting of thin solid films

    Energy Technology Data Exchange (ETDEWEB)

    Repetto, Luca; Setina Batic, Barbara; Firpo, Giuseppe; Piano, Emanuele; Valbusa, Ugo [Dipartimento di Fisica, Universita di Genova, Via Dodecaneso 33, 16146 Genova (Italy)

    2012-05-28

    We present experimental data and numerical simulations in order to show that the mechanism of spinodal dewetting is active during ion beam irradiation of thin solid films. The expected scaling law for the characteristic wavelengths versus the initial film thickness is modified by the presence of sputtering. The conclusion is fully supported by model simulation which shows a square law dependence for null sputtering yield and a bimodal trend when sputtering is included. This result is in contrast to earlier studies and opens the possibility to control and use ion induced dewetting for the fabrication of functional nanostructures.

  3. Ion implantation induced nanotopography on titanium and bone cell adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Braceras, Iñigo, E-mail: inigo.braceras@tecnalia.com [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Vera, Carolina; Ayerdi-Izquierdo, Ana [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Muñoz, Roberto [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); Lorenzo, Jaione; Alvarez, Noelia [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Maeztu, Miguel Ángel de [Private Practice, P° San Francisco, 43 A-1°, 20400 Tolosa (Spain)

    2014-08-15

    Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm{sup 2}) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

  4. Aluminum thin film enhanced IR nanosecond laser-induced frontside etching of transparent materials

    Science.gov (United States)

    Nieto, Daniel; Cambronero, Ferran; Flores-Arias, María Teresa; Farid, Nazar; O'Connor, Gerard M.

    2017-01-01

    Laser processing of glass is of significant commercial interest for microfabrication of precision optical engineering devices. In this work, a laser ablation enhancement mechanism for microstructuring of glass materials is presented. The method consists of depositing a thin film of aluminum on the front surface of the glass material to be etched. The laser beam modifies the glass material by being incident on this front-side. The influence of ablation fluence in the nanosecond regime, in combination with the deposition of the aluminum layer of various thicknesses, is investigated by determining the ablation threshold for different glass materials including soda-lime, borosilicate, fused silica and sapphire. Experiments are performed using single laser pulse per shot in an air environment. The best enhancement in terms of threshold fluence reduction is obtained for a 16 nm thick aluminum layer where a reduction of two orders of magnitude in the ablation threshold fluence is observed for all the glass samples investigated in this work.

  5. Effect of an absorbent overlay on the residual stress field induced by laser shock processing on aluminum samples

    Energy Technology Data Exchange (ETDEWEB)

    Rubio-Gonzalez, C. [Centro de Ingenieria y Desarrollo Industrial, Pie de la Cuesta No. 702, Desarrollo San Pablo, Queretaro, Qro. 76130 (Mexico)]. E-mail: crubio@cidesi.mx; Gomez-Rosas, G. [Departamento de Ciencias Exactas y Tecnologicas, Centro Universitario de los Lagos, Universidad de Guadalajara. Lagos de Moreno Jal. (Mexico); Ocana, J.L. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Molpeceres, C. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Banderas, A. [Centro de Ingenieria y Desarrollo Industrial, Pie de la Cuesta No. 702, Desarrollo San Pablo, Queretaro, Qro. 76130 (Mexico); Porro, J. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Morales, M. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain)

    2006-07-15

    Laser shock processing (LSP) or laser shock peening is a new technique for strengthening metals. This process induces a compressive residual stress field, which increases fatigue crack initiation life and reduces fatigue crack growth rate. Specimens of 6061-T6 aluminum alloy are used in this investigation. A convergent lens is used to deliver 2.5 J, 8 ns laser pulses by a Q-switch Nd:YAG laser, operating at 10 Hz. The pulses are focused to a diameter of 1.5 mm onto aluminum samples. Density of 2500 pulses/cm{sup 2} with infrared (1064 nm) radiation was used. The effect of an absorbent overlay on the residual stress field using this LSP setup and this energy level is evaluated. Residual stress distribution as a function of depth is assessed by the hole drilling method. It is observed that the overlay makes the compressive residual stress profile move to the surface. This effect is explained on the basis of the vaporization of the coat layer suppressing thermal effects on the metallic substrate. The effect of coating the specimen surface before LSP treatment may have advantages on improving wear and contact fatigue properties of this aluminum alloy.

  6. Aluminum film microdeposition at 775 nm by femtosecond laser-induced forward transfer

    Institute of Scientific and Technical Information of China (English)

    Li Yang; Chingyue Wang; Xiaochang Ni; Yinzhong Wu; Wei Jia; Lu Chai

    2007-01-01

    Micro-deposition of an aluminum film of 500-nm thickness on a quartz substrate was demonstrated by laserinduced forward transfer (LIFT) using a femtosecond laser pulse. With the help of atomic force microscopy (AFM) and scanning electron microscopy (SEM), the dependence of the morphology of deposited aluminum film on the irradiated laser pulse energy was investigated. As the laser fluence was slightly above the threshold fluence, the higher pressure of plasma for the thicker film made the free surface of solid phase burst out, which resulted in that not only the solid material was sputtered but also the deposited film in the liquid state was made irregularly.

  7. Neurofibrillary pathology and aluminum in Alzheimer's disease

    OpenAIRE

    Shin, R. W.; Lee, V.M.Y.; Trojanowski, J.Q.

    1995-01-01

    Since the first reports of aluminum-induced neurofibrillary degeneration in experimental animals, extensive studies have been performed to clarify the role played by aluminum in the pathogenesis of Alzheimer's disease (AD). Additional evidence implicating aluminum in AD includes elevated levels of aluminum in the AD brain, epidemiological data linking aluminum exposure to AD, and interactions between aluminum and protein components in the pathological lesions o...

  8. White upconversion luminescence in Tm3+/Ho3+/Yb3+ triply doped K+-Na+ ion-exchanged aluminum germanate glass channel waveguide

    Science.gov (United States)

    Liu, Xiao; Chen, Baojie; Pun, Edwin Yue Bun; Lin, Hai

    2013-01-01

    Rare-earth ions doped K+-Na+ ion-exchanged aluminum germanate (NMAG) glass channel waveguides have been designed and fabricated. Under 980 nm laser pumping, an intense upconversion white light transmission trace was observed in Tm3+/Ho3+/Yb3+ triply doped NMAG glass channel waveguide and a high-brightness light spot was achieved from the output end of the fiber connected to the waveguide channel. The fluorescent colors were diverse and located within or near the white region in CIE chromaticity diagram under various pumping powers. These admirable results indicate that Tm3+/Ho3+/Yb3+ triply doped NMAG channel waveguide is a promising light source for medical and high-precision processing illumination.

  9. Focused Ion Beam Induced Effects on MOS Transistor Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Abramo, Marsha T.; Antoniou, Nicholas; Campbell, Ann N.; Fleetwood, Daniel M.; Hembree, Charles E.; Jessing, Jeffrey R.; Soden, Jerry M.; Swanson, Scot E.; Tangyunyong, Paiboon; Vanderlinde, William E.

    1999-07-28

    We report on recent studies of the effects of 50 keV focused ion beam (FIB) exposure on MOS transistors. We demonstrate that the changes in value of transistor parameters (such as threshold voltage, V{sub t}) are essentially the same for exposure to a Ga+ ion beam at 30 and 50 keV under the same exposure conditions. We characterize the effects of FIB exposure on test transistors fabricated in both 0.5 {micro}m and 0.225 {micro}m technologies from two different vendors. We report on the effectiveness of overlying metal layers in screening MOS transistors from FIB-induced damage and examine the importance of ion dose rate and the physical dimensions of the exposed area.

  10. Rapid hardening induced by electric pulse annealing in nanostructured pure aluminum

    DEFF Research Database (Denmark)

    Zeng, Wei; Shen, Yao; Zhang, Ning

    2012-01-01

    Nanostructured pure aluminum was fabricated by heavy cold-rolling and then subjected to recovery annealing either by applying electric pulse annealing or by traditional air furnace annealing. Both annealing treatments resulted in an increase in yield strength due to the occurrence of a “dislocation...

  11. Alloying of metal nanoparticles by ion-beam induced sputtering

    Science.gov (United States)

    Magudapathy, P.; Srivastava, S. K.; Gangopadhyay, P.; Amirthapandian, S.; Saravanan, K.; Das, A.; Panigrahi, B. K.

    2017-01-01

    Ion-beam sputtering technique has been utilized for controlled synthesis of metal alloy nanoparticles of compositions that can be tuned. Analysis of various experimental results reveals the formation of Ag-Cu alloy nanoparticles on a silica substrate. Surface-plasmon optical resonance positions and observed shifts of Ag Bragg angles in X-ray diffraction pattern particularly confirm formation of alloy nanoparticles on glass samples. Sputtering induced nano-alloying mechanism has been discussed and compared with thermal mixing of Ag and Cu thin films on glass substrates. Compositions and sizes of alloy nanoparticles formed during ion-beam induced sputtering are found to exceed far from the values of thermal mixing.

  12. The role of ammonia in sulfuric acid ion induced nucleation

    Directory of Open Access Journals (Sweden)

    I. K. Ortega

    2008-06-01

    Full Text Available We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good accuracy-to-computational effort ratio. We have applied this strategy to evaluate the relevance of ternary ion induced nucleation; we have also performed calculations for neutral ternary nucleation for comparison. The results for neutral ternary nucleation agree with previous results, and confirm the important role of ammonia in enhancing the growth of sulfuric acid clusters. On the other hand, we have found that ammonia does not enhance the growth of ionic sulfuric acid clusters. The results also confirm that ion-induced nucleation is a barrierless process at high altitudes, but at ground level there exists a barrier due to the presence of a local minimum on the free energy surface.

  13. Confinement-Induced Resonances in Ultracold Atom-Ion Systems

    CERN Document Server

    Melezhik, Vladimir S

    2016-01-01

    We investigate confinement-induced resonances in a system composed by a tightly trapped ion and a moving atom in a waveguide. We determine the conditions for the appearance of such resonances in a broad region -- from the "long-wavelength" limit to the opposite case when the typical length scale of the atom-ion interaction essentially exceeds the transverse waveguide width. We find considerable dependence of the resonance position on the atomic mass which, however, disappears in the "long-wavelength" limit, where the result for the confined atom-atom scattering is reproduced. We also derive an analytic formula for the resonance position in the "long-wavelength zero-energy" limit. Our results, which can be investigated in current experiments, indicate a strategy to determine the atom-ion scattering length, the temperature of the atomic ensemble in the presence of an ion impurity, and a pathway to control the atom-phonon coupling in a one dimensional ion crystal in interaction with an atomic quantum gas.

  14. Ion-Induced Surface Modification of Magnetically Operated Contacts

    Directory of Open Access Journals (Sweden)

    Karen Arushanov

    2012-02-01

    Full Text Available A study has been made of permalloy (iron-nickel contacts of reed switches before and after ion-induced surface modification using atomic force and optical microscopy, Auger electron and X-ray photoelectron spectroscopy. It has been found that the formation of surface nitride layers enhances corrosion and erosion resistance of contacts. We proposed to produce such layers directly into sealed reed switches by means of pulsing glow-discharge nitrogen plasma.

  15. Controlling the profile of ion-cyclotron-resonant ions in JET with the wave-induced pinch effect

    NARCIS (Netherlands)

    Mantsinen, M. J.; Ingesson, L. C.; Johnson, T.; Kiptily, V. G.; Mayoral, M. L.; Sharapov, S. E.; Alper, B.; Bertalot, L.; Conroy, S.; Eriksson, L. G.; Hellsten, T.; Noterdaeme, J. M.; Popovichev, S.; Righi, E.; Tuccillo, A. A.

    2002-01-01

    Experiments on the JET tokamak show that the wave-induced pinch in the presence of toroidally asymmetric waves can provide a tool for controlling the profile of ion-cyclotron-resonant He-3 ions. Direct evidence for the wave-induced pinch has been obtained from the measured gamma-ray emission profile

  16. Neutron-induced reaction studies using stored ions

    Science.gov (United States)

    Glorius, Jan; Litvinov, Yuri A.; Reifarth, René

    2015-11-01

    Storage rings provide unique possibilities for investigations of nuclear reactions. Radioactive ions can be stored if the ring is connected to an appropriate facility and reaction studies are feasible at low beam intensities because of the recycling of beam particles. Using gas jet or droplet targets, charged particle-induced reactions on short-lived isotopes can be studied in inverse kinematics. In such a system a high-flux reactor could serve as a neutron target extending the experimental spectrum to neutron-induced reactions. Those could be studied over a wide energy range covering the research fields of nuclear astrophysics and reactor safety, transmutation of nuclear waste and fusion.

  17. Molecular Dynamics of XFEL-Induced Photo-Dissociation, Revealed by Ion-Ion Coincidence Measurements

    Directory of Open Access Journals (Sweden)

    Edwin Kukk

    2017-05-01

    Full Text Available X-ray free electron lasers (XFELs providing ultrashort intense pulses of X-rays have proven to be excellent tools to investigate the dynamics of radiation-induced dissociation and charge redistribution in molecules and nanoparticles. Coincidence techniques, in particular multi-ion time-of-flight (TOF coincident experiments, can provide detailed information on the photoabsorption, charge generation, and Coulomb explosion events. Here we review several such recent experiments performed at the SPring-8 Angstrom Compact free electron LAser (SACLA facility in Japan, with iodomethane, diiodomethane, and 5-iodouracil as targets. We demonstrate how to utilize the momentum-resolving capabilities of the ion TOF spectrometers to resolve and filter the coincidence data and extract various information essential in understanding the time evolution of the processes induced by the XFEL pulses.

  18. Development of the positron-induced ion-desorption apparatus

    CERN Document Server

    Kanazawa, I

    2002-01-01

    The principle of the positron-induced ion-desorption, which is developed recently, and experimental apparatus are explained and study of desorption of positron-induced hydrogen ion from surface of Ni is reported as an example. The slow positron beam system in the positron-induced ion-desorption spectroscopy is consisted of two stages, moderator and transformation from magnetic transport type to electrostatic transport type. Positron is antiparticle of electron and localized both outside and monolayer of surface, which is special futures and used to analyze the surface. The number of emission positive charge particles from the clean Ni surface was changed by coil current at 1.9 keV and 2.9 keV incident positron energy. The number of re-emission positron at 1.9 keV was larger than at 2.9 keV. The number of emission positive charge particles from the clean Ni surface adsorbed monolayer hydrogen atom were decreased with coil current at 1.9 keV and 2.9 keV. The number of desorption hydrogen particle at 1.9 keV was...

  19. Sulfur Dioxide Enhances Endogenous Hydrogen Sulfide Accumulation and Alleviates Oxidative Stress Induced by Aluminum Stress in Germinating Wheat Seeds

    Directory of Open Access Journals (Sweden)

    Dong-Bo Zhu

    2015-01-01

    Full Text Available Aluminum ions are especially toxic to plants in acidic soils. Here we present evidences that SO2 protects germinating wheat grains against aluminum stress. SO2 donor (NaHSO3/Na2SO3 pretreatment at 1.2 mM reduced the accumulation of superoxide anion, hydrogen peroxide, and malondialdehyde, enhanced the activities of guaiacol peroxidase, catalase, and ascorbate peroxidase, and decreased the activity of lipoxygenase in germinating wheat grains exposed to Al stress. We also observed higher accumulation of hydrogen sulfide (H2S in SO2-pretreated grain, suggesting the tight relation between sulfite and sulfide. Wheat grains geminated in water for 36 h were pretreated with or without 1 mM SO2 donor for 12 h prior to exposure to Al stress for 48 h and the ameliorating effects of SO2 on wheat radicles were studied. SO2 donor pretreatment reduced the content of reactive oxygen species, protected membrane integrity, and reduced Al accumulation in wheat radicles. Gene expression analysis showed that SO2 donor pretreatment decreased the expression of Al-responsive genes TaWali1, TaWali2, TaWali3, TaWali5, TaWali6, and TaALMT1 in radicles exposed to Al stress. These results suggested that SO2 could increase endogenous H2S accumulation and the antioxidant capability and decrease endogenous Al content in wheat grains to alleviate Al stress.

  20. Gas evolution behavior of aluminum in mortar

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, Shuji; Matsumoto, Junko; Banba, Tsunetaka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-10-01

    As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs.

  1. Beam Energy Scaling of Ion-Induced Electron Yield from K+ Ions Impact on Stainless Steel Surfaces

    CERN Document Server

    Kireeff-Covo, Michel; Barnard, John J; Bieniosek, Frank; Celata, C M; Cohen, Ronald; Friedman, Alex; Grote, D P; Kwan, Joe W; Lund, Steven M; Molvik, Arthur; Seidl, Peter; Vay, Jean-Luc; Vujic, Jasmina L; Westenskow, Glen

    2005-01-01

    The cost of accelerators for heavy-ion inertial fusion energy (HIF) can be reduced by using the smallest possible clearance between the beam and the wall from the beamline. This increases beam loss to the walls, generating ion-induced electrons that could be trapped by beam space charge potential into an "electron cloud," which can cause degradation or loss of the ion beam. In order to understand the physical mechanism of production of ion-induced electrons we have measured impact of K+ ions with energies up to 400 KeV on stainless steel surfaces near grazing incidence, using the ion source test stand (STS-500) at LLNL. The electron yield will be discussed and compared with experimental measurements from 1 MeV K+ ions in the High-Current Experiment at LBNL.*

  2. The LILIA (laser induced light ions acceleration) experiment at LNF

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, S. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Anania, M.P. [INFN LNF Frascati, Frascati (Italy); Caresana, M. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Cirrone, G.A.P. [INFN LNS Catania, Catania (Italy); De Martinis, C. [Physics Department, University of Milan and INFN, Milan (Italy); Delle Side, D. [LEAS, University of Salento and INFN, Lecce (Italy); Fazzi, A. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Gatti, G. [INFN LNF Frascati, Frascati (Italy); Giove, D. [Physics Department, University of Milan and INFN, Milan (Italy); Giulietti, D. [Physics Department, University of Pisa and INFN, Pisa (Italy); Gizzi, L.A.; Labate, L. [INO-CNR and INFN, Pisa (Italy); Londrillo, P. [Physics Department, University of Bologna and INFN, Bologna (Italy); Maggiore, M. [INFN LNL, Legnaro (Italy); Nassisi, V., E-mail: vincenzo.nassisi@le.infn.it [LEAS, University of Salento and INFN, Lecce (Italy); Sinigardi, S. [Physics Department, University of Bologna and INFN, Bologna (Italy); Tramontana, A.; Schillaci, F. [INFN LNS Catania, Catania (Italy); Scuderi, V. [INFN LNS Catania, Catania (Italy); Institute of Physics of the ASCR, Prague (Czech Republic); Turchetti, G. [Physics Department, University of Bologna and INFN, Bologna (Italy); and others

    2014-07-15

    Laser-matter interaction at relativistic intensities opens up new research fields in the particle acceleration and related secondary sources, with immediate applications in medical diagnostics, biophysics, material science, inertial confinement fusion, up to laboratory astrophysics. In particular laser-driven ion acceleration is very promising for hadron therapy once the ion energy will attain a few hundred MeV. The limited value of the energy up to now obtained for the accelerated ions is the drawback of such innovative technique to the real applications. LILIA (laser induced light ions acceleration) is an experiment now running at LNF (Frascati) with the goal of producing a real proton beam able to be driven for significant distances (50–75 cm) away from the interaction point and which will act as a source for further accelerating structure. In this paper the description of the experimental setup, the preliminary results of solid target irradiation and start to end simulation for a post-accelerated beam up to 60 MeV are given.

  3. Monte Carlo modeling of ion beam induced secondary electrons

    Energy Technology Data Exchange (ETDEWEB)

    Huh, U., E-mail: uhuh@vols.utk.edu [Biochemistry & Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996-0840 (United States); Cho, W. [Electrical and Computer Engineering, University of Tennessee, Knoxville, TN 37996-2100 (United States); Joy, D.C. [Biochemistry & Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996-0840 (United States); Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2016-09-15

    Ion induced secondary electrons (iSE) can produce high-resolution images ranging from a few eV to 100 keV over a wide range of materials. The interpretation of such images requires knowledge of the secondary electron yields (iSE δ) for each of the elements and materials present and as a function of the incident beam energy. Experimental data for helium ions are currently limited to 40 elements and six compounds while other ions are not well represented. To overcome this limitation, we propose a simple procedure based on the comprehensive work of Berger et al. Here we show that between the energy range of 10–100 keV the Berger et al. data for elements and compounds can be accurately represented by a single universal curve. The agreement between the limited experimental data that is available and the predictive model is good, and has been found to provide reliable yield data for a wide range of elements and compounds. - Highlights: • The Universal ASTAR Yield Curve was derived from data recently published by NIST. • IONiSE incorporated with the Curve will predict iSE yield for elements and compounds. • This approach can also handle other ion beams by changing basic scattering profile.

  4. The LILIA (laser induced light ions acceleration) experiment at LNF

    Science.gov (United States)

    Agosteo, S.; Anania, M. P.; Caresana, M.; Cirrone, G. A. P.; De Martinis, C.; Delle Side, D.; Fazzi, A.; Gatti, G.; Giove, D.; Giulietti, D.; Gizzi, L. A.; Labate, L.; Londrillo, P.; Maggiore, M.; Nassisi, V.; Sinigardi, S.; Tramontana, A.; Schillaci, F.; Scuderi, V.; Turchetti, G.; Varoli, V.; Velardi, L.

    2014-07-01

    Laser-matter interaction at relativistic intensities opens up new research fields in the particle acceleration and related secondary sources, with immediate applications in medical diagnostics, biophysics, material science, inertial confinement fusion, up to laboratory astrophysics. In particular laser-driven ion acceleration is very promising for hadron therapy once the ion energy will attain a few hundred MeV. The limited value of the energy up to now obtained for the accelerated ions is the drawback of such innovative technique to the real applications. LILIA (laser induced light ions acceleration) is an experiment now running at LNF (Frascati) with the goal of producing a real proton beam able to be driven for significant distances (50-75 cm) away from the interaction point and which will act as a source for further accelerating structure. In this paper the description of the experimental setup, the preliminary results of solid target irradiation and start to end simulation for a post-accelerated beam up to 60 MeV are given.

  5. Ion Beam Induced Charge analysis of diamond diodes

    Science.gov (United States)

    Lehnert, J.; Meijer, J.; Ronning, C.; Spemann, D.; Vittone, E.

    2017-08-01

    Diamond based p-i-n light-emitting diodes, developed to electrically drive single-photon sources in the visible spectral region at room temperature, have the potential to play a key role in quantum based technologies. In order to gain more insight into the charge injection mechanism occurring in these diodes, we carried out an experiment aimed to investigate the electrostatics and the charge carrier transport by the Ion Beam Induced Charge (IBIC) technique, using 1 MeV He microbeam raster scanning of p-i-n structures fabricated in a high purity diamond substrate, using lithographic masking and P and B ion implantation doping. Charge Collection Efficiency (CCE) maps obtained at low ion fluence, show that induced charge pulses arise only from the P-implanted region, whereas no IBIC signals arise from the B-implanted region. This result suggests the formation of a slightly p-type doped substrate, forming a n+-p-p+, rather than the expected p-i-n, structure. However, for high fluence scans of small areas covering the intrinsic gap, CCE maps are more uniform and compatible with a p-i-n structure, suggesting the occurrence of a ;priming effect;, which saturates acceptor levels resulting in a decrease of the effective doping of the diamond substrate.

  6. Identity of Passive Film Formed on Aluminum in Li-ion BatteryElectrolytes with LiPF6

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xueyuan; Devine, T.M.

    2006-09-01

    The passive film that forms on aluminum in 1:1 ethylene carbonate + ethylmethyl carbonate with 1.2M LiPF{sub 6} and 1:1 ethylene carbonate + dimethyl carbonate with 1.0M LiPF{sub 6} was investigated by a combination of electrochemical quartz crystal microbalance measurements (EQCM), electrochemical impedance spectroscopy (EIS), and x-ray photoelectron spectroscopy. During anodic polarization of aluminum a film of AlF{sub 3} forms on top of the air-formed oxide, creating a duplex, or two-layered film. The thickness of the AlF{sub 3} increases with the applied potential. Independent measurements of film thickness by EQCM and EIS indicate that at a potential of 5.5V vs. Li/Li{sup +}, the thickness of the AlF{sub 3} is approximately 1 nm.

  7. Ion-irradiation-induced hardening in Inconel 718

    Science.gov (United States)

    Hunn, J. D.; Lee, E. H.; Byun, T. S.; Mansur, L. K.

    2001-07-01

    Inconel 718 is a material under consideration for areas in the target region of the spallation neutron source (SNS), now under construction at Oak Ridge National Laboratory (ORNL) in the US. In these positions, displacement damage from protons and neutrons will affect the mechanical properties. In addition, significant amounts of helium and hydrogen will build up in the material due to transmutation reactions. Nanoindentation measurements of solution-annealed (SA) Inconel 718 specimens, implanted with Fe-, He-, and H-ions to simulate SNS target radiation conditions, have shown that hardening occurs due to ion-induced displacement damage as well as due to the build-up of helium bubbles in the irradiated layer. Precipitation-hardened (PH) Inconel 718 also exhibited hardening by helium build-up but showed softening as a function of displacement damage due to dissolution of the γ ' and γ″ precipitates.

  8. Semiconductor characterization by scanning ion beam induced charge (IBIC) microscopy

    CERN Document Server

    Vittone, E; Olivero, P; Manfredotti, C; Jaksic, M; Giudice, A Lo; Fizzotti, F; Colombo, E

    2016-01-01

    The acronym IBIC (Ion Beam Induced Charge) was coined in early 1990's to indicate a scanning microscopy technique which uses MeV ion beams as probes to image the basic electronic properties of semiconductor materials and devices. Since then, IBIC has become a widespread analytical technique to characterize materials for electronics or for radiation detection, as testified by more than 200 papers published so far in peer-reviewed journals. Its success stems from the valuable information IBIC can provide on charge transport phenomena occurring in finished devices, not easily obtainable by other analytical techniques. However, IBIC analysis requires a robust theoretical background to correctly interpret experimental data. In order to illustrate the importance of using a rigorous mathematical formalism, we present in this paper a benchmark IBIC experiment aimed to test the validity of the interpretative model based on the Gunn's theorem and to provide an example of the analytical capability of IBIC to characteriz...

  9. Multivariate analysis of Ion Beam Induced Luminescence spectra of irradiated silver ion-exchanged silicate glasses

    Science.gov (United States)

    Valotto, Gabrio; Quaranta, Alberto; Cattaruzza, Elti; Gonella, Francesco; Rampazzo, Giancarlo

    A multivariate analysis is used for the identification of the spectral features in Ion Beam Induced Luminescence (IBIL) spectra of soda-lime silicate glasses doped with silver by Ag+-Na+ ion exchange. Both Principal Component Analysis and multivariate analysis were used to characterize time-evolving IBIL spectra of Ag-doped glasses, by means of the identification of the number and of the wavelength positions of the main luminescent features and the study of their evolution during irradiation. This method helps to identify the spectral features of the samples spectra, even when partially overlapped or less intense. This analysis procedure does not require additional input such as the number of peaks.

  10. Recent studies in heavy ion induced fission reactions

    Science.gov (United States)

    Choudhury, R. K.

    2001-08-01

    Nuclear fission process involves large scale shape changes of the nucleus, while it evolves from a nearly spherical configuration to two separated fission fragments. The dynamics of these shape changes in the nuclear many body system is governed by a strong interplay of the collective and single particle degrees of freedom. With the availability of heavy ion accelerators, there has been an impetus to study the nuclear dynamics through the investigations of nucleus--nucleus collisions involving fusion and fission process. From the various investigations carried out in the past years, it is now well recognized that there is large scale damping of collective modes in heavy ion induced fission reactions, which in other words implies that nuclear motion is highly viscous. In recent years, there have been many experimental observations in heavy ion induced fission reactions at medium bombarding energies, which suggest possible occurrence of various non-equilibrium modes of fission such as quasi-fission, fast fission and pre-equilibrium fission, where some of the internal degrees of freedom of the nucleus is not fully equilibrated. We have carried out extensive investigations on the fission fragment angular distributions at near barrier bombarding energies using heavy fissile targets. The measured fragment anisotropies when compared with the standard saddle point model (SSPM) calculations show that for projectile-target systems having zero or low ground state spins, the angular anisotropy exhibits a peak-like behaviour at the sub barrier energies, which cannot be explained by the SSPM calculations. For projectiles or targets with large ground state spins, the anomalous peaking gets washed out due to smearing of the K-distribution by the intrinsic entrance channel spins. Recently studies have been carried out on the spin distributions of fission fragments through the gamma ray multiplicity measurements. The fission fragments acquire spin mainly from two sources: (i) due to

  11. AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors with reduced leakage current and enhanced breakdown voltage using aluminum ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Shichuang [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Fu, Kai, E-mail: kfu2009@sinano.ac.cn, E-mail: cqchen@mail.hust.edu.cn; Yu, Guohao; Zhang, Zhili; Song, Liang; Deng, Xuguang; Li, Shuiming; Sun, Qian; Cai, Yong; Zhang, Baoshun [Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Qi, Zhiqiang; Dai, Jiangnan; Chen, Changqing, E-mail: kfu2009@sinano.ac.cn, E-mail: cqchen@mail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2016-01-04

    This letter has studied the performance of AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors on silicon substrate with GaN buffer treated by aluminum ion implantation for insulating followed by a channel regrown by metal–organic chemical vapor deposition. For samples with Al ion implantation of multiple energies of 140 keV (dose: 1.4 × 10{sup 14} cm{sup −2}) and 90 keV (dose: 1 × 10{sup 14} cm{sup −2}), the OFF-state leakage current is decreased by more than 3 orders and the breakdown voltage is enhanced by nearly 6 times compared to the samples without Al ion implantation. Besides, little degradation of electrical properties of the 2D electron gas channel is observed where the maximum drain current I{sub DSmax} at a gate voltage of 3 V was 701 mA/mm and the maximum transconductance g{sub mmax} was 83 mS/mm.

  12. A new prompt heavy-ion-induced fission mode

    Indian Academy of Sciences (India)

    W Udo Schröder

    2015-08-01

    Fission instabilities induced by mechanical and thermal stresses on intermediate nuclear systems in heavy-ion reactions are poorly understood but should reveal independent evidence for the nuclear equation of state (EoS), notably the tensile strength of finite nuclei. Experimental evidence is presented in support of a new mode of prompt fission of the composite nucleus formed in central 78Kr+40Ca collisions at only a few MeV per nucleon above the interaction barrier. The new process recalls the ‘L-window for fusion’ phenomenon, which was predicted by the early reaction theory and reappears in modern DFT model calculations.

  13. Optically induced structural phase transitions in ion Coulomb crystals

    DEFF Research Database (Denmark)

    Horak, Peter; Dantan, Aurelien Romain; Drewsen, Michael

    2012-01-01

    , such as body-centered cubic and face-centered cubic, can be suppressed by a proper choice of the potential depth and periodicity. Furthermore, by varying the harmonic trap parameters and/or the optical potential in time, controlled transitions between crystal structures can be obtained with close to unit......We investigate numerically the structural dynamics of ion Coulomb crystals confined in a three-dimensional harmonic trap when influenced by an additional one-dimensional optically induced periodical potential. We demonstrate that transitions between thermally excited crystal structures...

  14. Investigation of phase explosion in aluminum induced by nanosecond double pulse technique

    Energy Technology Data Exchange (ETDEWEB)

    Jafarabadi, Marzieh Akbari; Mahdieh, Mohammad Hossein, E-mail: mahdm@iust.ac.ir

    2015-08-15

    Highlights: • Single and collinear double pulse configurations were used for laser ablation of aluminum target in air. • The 5, 10, 15 and 20 ns delay times between pre pulse and main pulse in double pulse arrangement was investigated. • In comparison between single and double pulse regimes, the phase explosion threshold fluence is decreased in double pulse configuration. • The plasma shielding effect reduces the crater depth in lower laser fluence in double pulse configuration rather that its in single pulse configuration. - Abstract: In this paper, the influence of double pulse technique on phase explosion threshold in laser ablation of an aluminum target is investigated. Single and double pulse laser ablation of aluminum target was performed by a high power Nd:YAG laser beam in ambient air. In the double pulse excitation, the two pulses were from a single laser source which separated by a delay time in the range of 5–20 ns. Measuring ablation depth and rate, the phase explosion threshold was estimated in double pulse configuration as well as in the single pulse regime. The results show that in comparison between single and double pulse regimes, the phase explosion threshold fluence is decreased in double pulse configuration. The lowest phase explosion threshold fluence of 0.9 J/cm{sup 2} was obtained at 5 ns delay time. The results also show that plasma shielding effect reduced crater depth at a laser fluence which depended on the laser ablation configuration (single pulse or double pulse). The reduction of crater depth occurs at lower laser fluences for double pulse regime.

  15. Molecular understanding of aluminum-induced topological changes in (CCG)12 triplet repeats: relevance to neurological disorders.

    Science.gov (United States)

    Latha, Kallur Siddaramaiah; Anitha, Suram; Rao, Kosagi Sharaf Jagannatha; Viswamitra, Mysore Ananthamurthy

    2002-10-09

    Recent studies have shown that gene mutations are involved in the pathology of neurological disorders. CCG repeats cause genetic instability and are localized at the 5' end of the non-coding regions of the FMR1 gene in fragile X syndrome. Our studies for the first time showed that aluminum (Al) levels were elevated in the serum samples of fragile X syndrome and also provide evidence for the interaction of aluminum with (CCG)12-repeats. Circular dichroism spectroscopic studies of (CCG)12 indicated B-DNA conformation and in the presence of Al (10(-5) M) CCG repeats attained Z-DNA conformation. Further spectroscopic studies, which included melting profiles, ethidium bromide binding patterns and interaction of Z-DNA specific polyclonal antibodies confirmed the Z-conformation in (CCG)12-repeats in the presence of Al (10(-5) M). It is interesting to mention that Al-induced Z-conformation is stable even after the total removal of Al from CCG by desferoximine, a chelating drug. This is the first report to proof the role of Al in modulating the DNA (CCG repeats) topology and this information provides a clue about the possible involvement of Al at a molecular level in neurological/neurodegenerative disorders.

  16. The study of laser induced fluorescence of tooth hard tissues with aluminum phthalocyanine nanoparticles

    Science.gov (United States)

    Farrakhova, D. S.; Kuznetsova, J. O.; Loschenov, V. B.

    2016-08-01

    This work is about the possibility of fluorescence diagnosis application with the use of aluminum phthalocyanine nanoparticles (nAlPc) in order to detect enamel microdamage. For the investigation, five human teeth samples of various age groups were removed for various reasons. The autofluorescence spectrums of these samples hard tissues and fluorescence spectrums of nAlPc mixed with enamel powder were obtained during the experiment. The research shows that sample pathogenic microflora causes nAlPc fluorescence. This fact will allow detecting enamel microdamage in future studies.

  17. Pressure-induced hydrogen-dominant metallic state in aluminum hydride.

    Science.gov (United States)

    Goncharenko, Igor; Eremets, M I; Hanfland, M; Tse, J S; Amboage, M; Yao, Y; Trojan, I A

    2008-02-01

    Two structural transitions in covalent aluminum hydride AlH3 were characterized at high pressure. A metallic phase stable above 100 GPa is found to have a remarkably simple cubic structure with shortest first-neighbor H-H distances ever measured except in H2 molecule. Although the high-pressure phase is predicted to be superconductive, this was not observed experimentally down to 4 K over the pressure range 120-164 GPa. The results indicate that the superconducting behavior may be more complex than anticipated.

  18. Fatigue Induced Alteration of the Superficial Strength Properties of 2024 Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    K.-D. Bouzakis; I. Mirisidis; Sp. G. Pantelakis; A.N. Chamos

    2011-01-01

    aluminum alloy 2024 T3 specimens have been subjected to constant amplitude fatigue loading at R=0.1. During fatigue, an appreciable increase of the surface hardness of the material at the meso-scale can be observed and captured by means of nanoindentations. Surface hardness increases with increasing fatigue stress amplitude and advancing number of applied fatigue cycles. Observed increase of specimen surface hardening degree during fatigue causes an evolution of superficial mechanical strength properties of the alloy. Stress-strain curves associated with the evoluting superficial mechanical properties are derived, employing a developed finite element method (FEM)-supported evaluation procedure of nanoindentation experimental results.

  19. Hesperidin and Silibinin Ameliorate Aluminum-Induced Neurotoxicity: Modulation of Antioxidants and Inflammatory Cytokines Level in Mice Hippocampus.

    Science.gov (United States)

    Jangra, Ashok; Kasbe, Prajapati; Pandey, Surya Narayan; Dwivedi, Shubham; Gurjar, Satendra S; Kwatra, Mohit; Mishra, Murli; Venu, Athira K; Sulakhiya, Kunjbihari; Gogoi, Ranadeep; Sarma, Nitul; Bezbaruah, Babul K; Lahkar, Mangala

    2015-12-01

    Mounting evidence suggests that long-term aluminum exposure results in severe toxic effects, including neurobehavioral and neurochemical anomalies. The present study was performed to examine the neuroprotective potential of hesperidin and silibinin against aluminum chloride (AlCl3)-induced neurotoxicity in mice. AlCl3 (100 mg/kg/day) was injected daily through oral gavage for 42 days. Concomitantly, hesperidin (50 and 100 mg/kg/day, p.o.) and silibinin (100 and 200 mg/kg/day, p.o.) was administered for 42 days in different groups. The extent of cognitive impairment was assessed by Morris water maze and novel object recognition test on the 43rd day. Neurotoxicity was assessed by measuring oxido-nitrosative stress and proinflammatory cytokines in the hippocampus of mice. Six weeks treatment with AlCl3 caused cognitive impairment as indicated by an increase in the retention latency time and reduction in the percentage of recognition index. AlCl3-treated group showed oxido-nitrosative stress as indicated by increase in the level of lipid peroxidation, nitrite and depleted reduced glutathione, catalase activity in the hippocampus. Moreover, the chronic AlCl3 administration raised the proinflammatory cytokines (interleukin-1β and tumor necrosis factor-α) level and increased acetylcholinesterase activity and reduced the BDNF content in the hippocampus of AlCl3-treated animals. However, chronic treatment with hesperidin and silibinin at higher doses significantly ameliorated the AlCl3-induced cognitive impairment and hippocampal biochemical anomalies. The present study clearly indicated that hesperidin and silibinin exert neuroprotective effects against AlCl3-induced cognitive impairment and neurochemical changes. Amelioration of cognitive impairment may be attributed to the impediment of oxido-nitrosative stress and inflammation in the hippocampus.

  20. Ion beam induced luminescence analysis of painting pigments

    Energy Technology Data Exchange (ETDEWEB)

    Quaranta, A. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy); E-mail: quaranta@ing.unitn.it; Salomon, J. [Centre de Recherche et de Restauration des Musees de France, CNRS UMR 171, rue des Pyramides, 75041 Paris Cedex 01 (France); Dran, J.C. [Centre de Recherche et de Restauration des Musees de France, CNRS UMR 171, rue des Pyramides, 75041 Paris Cedex 01 (France); Tonezzer, M. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy); Della Mea, G. [Universita di Trento, Dipartimento di Ingegneria dei Materiali e, delle Tecnologie Inustriali (DIMTI), via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via Universita 2, I-35020, Legnaro, Padova (Italy)

    2007-01-15

    Ion beam induced luminescence (IBIL) has been exploited for the first time in the analysis of inorganic painting pigments. The elemental constituents of the different compounds have been determined by particle induced X-ray emission (PIXE). The acquisition time of each spectrum ranges from 100 ms to a few seconds, depending on the luminescence intensity. The luminescence features are fingerprints of the different compounds, thus identifying the provenience of pigments of the same nominal composition. Organic varnish layers do not affect the IBIL features, allowing the identification of pigments, like lapis-lazuli, whose identification with PIXE is hindered by the varnish. IBIL proved to be a technique complementary to PIXE in the archeometry and cultural heritage analysis fields.

  1. Nonelastic nuclear reactions induced by light ions with the BRIEFF code

    CERN Document Server

    Duarte, H

    2010-01-01

    The intranuclear cascade (INC) code BRIC has been extended to compute nonelastic reactions induced by light ions on target nuclei. In our approach the nucleons of the incident light ion move freely inside the mean potential of the ion in its center-of-mass frame while the center-of-mass of the ion obeys to equations of motion dependant on the mean nuclear+Coulomb potential of the target nucleus. After transformation of the positions and momenta of the nucleons of the ion into the target nucleus frame, the collision term between the nucleons of the target and of the ion is computed taking into account the partial or total breakup of the ion. For reactions induced by low binding energy systems like deuteron, the Coulomb breakup of the ion at the surface of the target nucleus is an important feature. Preliminary results of nucleon production in light ion induced reactions are presented and discussed.

  2. Understanding pH and ionic strength effects on aluminum sulfate-induced microalgae flocculation.

    Science.gov (United States)

    Cui, Y; Yuan, W; Cheng, J

    2014-08-01

    The objective of this study was to understand the effect of pH and ionic strength of aluminum sulfate on the flocculation of microalgae. It was found that changing pH and ionic strength influenced algal flocculation by changing the zeta potential of cells, which was described by the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO). For both algal species of Scenedesmus dimorphus and Nannochloropsis oculata, cells with lower total DLVO interaction energy had higher flocculation efficiency, indicating that the DLVO model was qualitatively accurate in predicting the flocculation of the two algae. However, the two algae responded differently to changing pH and ionic strength. The flocculation of N. oculata increased with increasing aluminum sulfate concentration and favored either low (pH 5) or high (pH 10) pH where cells had relatively low negative surface charges. For S. dimorphus, the highest flocculation was achieved at low ionic strength (1 μM) or moderate pH (pH 7.5) where cell surface charges were fully neutralized (zero zeta potential).

  3. Micronuclei induction in human lymphocytes induced by carbon ions exposion along the penetrate depth of ions in water

    Science.gov (United States)

    Wang, Z. Z.; Li, W. J.; Zhi, D. J.; Qu, Y.; Jing, X. G.

    2009-08-01

    Here we used cytokinesis-block micronucleus assay to measure the biological response along the penetrate depth of ions in water in human lymphocytes exposed to 100 MeV/u incident carbon ions in vitro. Polyethylene shielding was used to change the penetration depth of ions in water. A quantitative biological response curve was generated for micronuclei induction. The results showed a marked increase with the penetrate depth of ions in water in the micronuclei formation, which was consistent with a linear-energy-transfer dependent increase in biological effectiveness. The dose-response relationship for MN information was different at different penetrate depth of ions in water, at the 6 and 11.2 mm penetrate depth of ions in water, the dose-response relationships for the micronucleus frequencies induced by carbon ions irradiation were linear; while it was power function at 17.1 mm penetrate depth.

  4. Heavy-ion induced genetic changes and evolution processes

    Science.gov (United States)

    Yang, C. H.; Craise, L. M.; Durante, M.; Mei, M.

    1994-01-01

    On Moon and Mars, there will be more galactic cosmic rays and higher radiation doses than on Earth. Our experimental studies showed that heavy ion radiation can effectively cause mutation and chromosome aberrations and that high Linear Energy Transfer (LET) heavy-ion induced mutants can be irreversible. Chromosome translocations and deletions are common in cells irradiated by heavy particles, and ionizing radiations are effective in causing hyperploidy. The importance of the genetic changes in the evolution of life is an interesting question. Through evolution, there is an increase of DNA content in cells from lower forms of life to higher organisms. The DNA content, however, reached a plateau in vertebrates. By increasing DNA content, there can be an increase of information in the cell. For a given DNA content, the quality of information can be changed by rearranging the DNA. Because radiation can cause hyperploidy, an increase of DNA content in cells, and can induce DNA rearrangement, it is likely that the evolution of life on Mars will be effected by its radiation environment. A simple analysis shows that the radiation level on Mars may cause a mutation frequency comparable to that of the spontaneous mutation rate on Earth. To the extent that mutation plays a role in adaptation, radiation alone on Mars may thus provide sufficient mutation for the evolution of life.

  5. Removal of aluminum, iron and manganese ions from industrial wastes using granular activated carbon and Amberlite IR-120H

    Directory of Open Access Journals (Sweden)

    Mohamed E. Goher

    2015-01-01

    Full Text Available The removal of aluminum, iron and manganese from some pollution sources that drain into Ismailia Canal has been investigated using two different sorbents; granular activated carbon (GAC and Amberlite IR-120H (AIR-120H. Batch equilibrium experiments showed that the two sorbents have maximum removal efficiency for aluminum and iron pH 5 and 10 min contact time in ambient room temperature, while pH 7 and 30 min were the most appropriate for manganese removal. Dosage of 2 g/l for both GAC and AIR-120H was established to give the maximum removal capacity. At optimum conditions, the removal trend was in order of Al+3 > Fe+2 > Mn+2 with 99.2, 99.02 and 79.05 and 99.55, 99.42 and 96.65% of metal removal with GAC and AIR-120H, respectively. For the three metals, Langmuir and Freundlich isotherms showed higher R2 values, with a slightly better fitting for the Langmuir model. In addition, separation factors (RL and exponent (n values indicated favorable Langmuir (0 < RL < 1 and Freundlich (1 < n < 10 approach. GAC and AIR-120H can be used as excellent alternative, effective and inexpensive materials to remove high amounts of heavy metals from waste water.

  6. Protective Effect of Ginkgo Biloba Leaf Extract on Learning and Memory Deficit Induced by Aluminum in Model Rats

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To examine the protective effect of Ginkgo biloba leaf extract (GbE) on learning and memory deficit induced by aluminum chloride (AlCl3), and explore its mechanisms. Methods: The rat models with learning and memory deficit were induced by administering via gastrogavage and drinking of AlCl3 solution. And the model rats were treated with GbE at the dose of 50, 100, 200 mg/kg every day for 2months accompanied with drinking of AlCl3 solution, respectively. Their abilities of spatial learning and memory were tested by Morris water maze, and the acetylcholinesterase (AChE) activity in serum was assayed with chemical method, the AChE expression in hippocampus was observed by immunohistochemistry assay,and then quantitative analysis was done by BI 2000 image analysis system. Results: Learning and memory deficit of rats could be induced by AlCl3 solution (P<0.01), and AChE expressions in rats hippocampus were increased (P<0.01); GbE ameliorated learning and memory deficit and reduced AChE expression in rats hippocampus in a dose-dependent manner, while GbE significantly increased serum AChE activity at the dose of 200 mg/kg each day (P<0.05). Conclusion: GbE can ameliorate learning and memory deficit induced by AlCl3, which may be due to its inhibition of the AChE expression in hippocampus.

  7. Advances in aluminum pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Sudour, Michel; Maintier, Philippe [PPG Industries France, 3 Z.A.E. Les Dix Muids, B.P. 89, F-59583 Marly (France); Simpson, Mark [PPG Industries Inc., 1200 Piedmont Troy, Michigan 48083 (United States); Quaglia, Paolo [PPG Industries Italia, Via Garavelli 21, I-15028 Quattordio (Italy)

    2004-07-01

    As automotive manufacturers continue to look for ways to reduce vehicle weight, aluminum is finding more utility as a body panel component. The substitution of cold-rolled steel and zinc-coated substrates with aluminum has led to new challenges in vehicle pretreatment. As a result, changes to traditional pretreatment chemistries and operating practices are necessary in order to produce an acceptable coating on aluminum body panels. These changes result in increased sludging and other undesirable characteristics. In addition to the chemistry changes, there are also process-related problems to consider. Many existing automotive pretreatment lines simply were not designed to handle aluminum and its increased demands on filtration and circulation equipment. To retrofit such a system is capital intensive and in addition to requiring a significant amount of downtime, may not be totally effective. Thus, the complexities of pre-treating aluminum body panels have actually had a negative effect on efforts to introduce more aluminum into new vehicle design programs. Recent research into ways of reducing the negative effects has led to a new understanding of the nature of zinc phosphate bath -aluminum interactions. Many of the issues associated with the pretreatment of aluminum have been identified and can be mitigated with only minor changes to the zinc phosphate bath chemistry. The use of low levels of soluble Fe ions, together with free fluoride, has been shown to dramatically improve the efficiency of a zinc phosphate system processing aluminum. Appearance of zinc phosphate coatings, coating weights and sludge are all benefited by this chemistry change. (authors)

  8. Microstructural Development during Welding of Silicon- and Aluminum-Based Transformation-Induced Plasticity Steels—Inclusion and Elemental Partitioning Analysis

    NARCIS (Netherlands)

    Amirthalingam, M.; Hermans, M.; Richardson, I.

    2009-01-01

    Microstructural development in gas tungsten arc (GTA) welded silicon- and aluminum-based transformation-induced plasticity (TRIP) steels was studied by optical and electron microscopy. The fusion zone (FZ) of both welds contained complex inclusions. Energy-dispersive spectroscopic (EDS) analysis on

  9. X-ray analysis of mechanical and thermal effects induced by femtosecond laser treatment of aluminum single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Valette, S. [Laboratoire Traitement du Signal et Instrumentation, Universite Jean Monnet, UMR CNRS 5516, 10 rue Barrouin 42000 Saint-Etienne (France)]. E-mail: stephane.valette@ec-lyon.fr; Le Harzic, R. [Laboratoire Traitement du Signal et Instrumentation, Universite Jean Monnet, UMR CNRS 5516, 10 rue Barrouin 42000 Saint-Etienne (France); Audouard, E. [Laboratoire Traitement du Signal et Instrumentation, Universite Jean Monnet, UMR CNRS 5516, 10 rue Barrouin 42000 Saint-Etienne (France); Huot, N. [Laboratoire Traitement du Signal et Instrumentation, Universite Jean Monnet, UMR CNRS 5516, 10 rue Barrouin 42000 Saint-Etienne (France); Fillit, R. [Ecole Nationale Superieure des Mines de Saint-Etienne, 158 Cours Fauriel, 42023 Saint-Etienne Cedex 2 (France); Fortunier, R. [Ecole Nationale Superieure des Mines de Saint-Etienne, 158 Cours Fauriel, 42023 Saint-Etienne Cedex 2 (France)

    2006-04-30

    Surface marking of aluminum single crystal is performed with femtosecond laser pulses. X-ray analysis allows to measure thermal and mechanical effects induced by the femtosecond laser pulses. These effects are estimated by comparing the pole figures (crystallinity) and the broadening of the diffraction peaks (mechanical contribution) before and after the laser irradiation. The results show that the femtosecond laser treatment ensures a re-crystallization of the structure and the presence of mechanical residual stresses. The analysis of the pole figures provides the sign of a re-crystallization on smaller volumes compared to initial ones. After the laser irradiation, the crystallization is perfectly oriented like the (1 1 0) orientation of the massive sample. Moreover, following the laser treatment, we show that the crystallographic structure is purer than the initial one. We also prove that the laser effect is persistent on a typical scale of 10 {mu}m beyond the surface.

  10. 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.

  11. Investigation of the crater-like microdefects induced by laser shock processing with aluminum foil as absorbent layer

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Y.X., E-mail: yeyunxia@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 21203 (China); Jiangsu Provincial Key Laboratory for Science and Technology of Photon Manufacturing, Jiangsu University, Zhenjiang 212013 (China); Xuan, T.; Lian, Z.C.; Feng, Y.Y.; Hua, X.J. [School of Mechanical Engineering, Jiangsu University, Zhenjiang 21203 (China)

    2015-06-01

    Highlights: • Crater-like microdefects formed on metal surface during laser shock process. • The air bubbles in the bonding material are responsible for forming microdefects. • Adiabatic compression of the air bubbles increases the temperature effectively. • Secondary shock wave induced by air bubbles is responsible for forming the defects. • Temperature increases due to shock heat and plastic deformation are limited. - Abstract: This paper reports that 3D crater-like microdefects form on the metal surface when laser shock processing (LSP) is applied. LSP was conducted on pure copper block using the aluminum foil as the absorbent material and water as the confining layer. There existed the bonding material to attach the aluminum foil on the metal target closely. The surface morphologies and metallographs of copper surfaces were characterized with 3D profiler, the optical microscopy (OM) or the scanning electron microscopy (SEM). Temperature increases of metal surface due to LSP were evaluated theoretically. It was found that, when aluminum foil was used as the absorbent material, and if there existed air bubbles in the bonding material, the air temperatures within the bubbles rose rapidly because of the adiabatic compression. So at the locations of the air bubbles, the metal materials melted and micromelting pool formed. Then under the subsequent expanding of the air bubbles, a secondary shock wave was launched against the micromelting pool and produced the crater-like microdefects on the metal surface. The temperature increases due to shock heat and high-speed deformation were not enough to melt the metal target. The temperature increase induced by the adiabatic compression of the air bubbles may also cause the gasification of the metal target. This will also help form the crater-like microdefects. The results of this paper can help to improve the surface quality of a metal target during the application of LSP. In addition, the results provide another

  12. Single and double long pulse laser ablation of aluminum induced in air and water ambient

    Science.gov (United States)

    Akbari Jafarabadi, Marzieh; Mahdieh, Mohammad Hossein

    2017-02-01

    In this paper, single pulse and double pulse laser ablation of an aluminum target in two interaction ambient was investigated experimentally. The interaction was performed by nanosecond Nd:YAG laser beam in air and four depths (i.e. 9, 13, 17, and 21 mm) of distilled water ambient. The irradiation was carried out in single and collinear double pulse configurations in both air and liquid ambient. Crater geometry (depth and diameter) was measured by an optical microscope. The results indicated that the crater geometry strongly depends on both single pulse and double pulse configurations and interaction ambient. In single pulse regime, the crater diameter is higher for all water depths compared to that of air. However, the crater depth, depend on water depth, is higher or lower than the crater depth in air. In double pulse laser ablation, there are greater values for both crater diameters and crater depths in the water.

  13. Oxidation-Induced Surface Roughening of Aluminum Nanoparticles Formed in an Ablation Plume

    Science.gov (United States)

    Förster, Georg Daniel; Girault, Marie; Menneveux, Jérôme; Lavisse, Luc; Jouvard, Jean-Marie; Marco de Lucas, Maria del Carmen; Potin, Valérie; Ouf, François-Xavier; Kerkar, Moussa; Le Garrec, Jean-Luc; Carvou, Erwann; Carles, Sophie; Rabilloud, Franck; Calvo, Florent; Yu, Jin; Mitchell, James Brian

    2015-12-01

    Nanoparticles formed within an ablation plume produced by the impact of a nanosecond laser pulse on the surface of an aluminum target have been directly measured using small-angle x-ray scattering. The target was immersed in an oxygen-nitrogen gas mixture at atmospheric pressure with the O2/N2 ratio being precisely controlled. The results for an increasing oxygen content reveal remarkable effects on the morphology of the generated particles, which include a decrease in the particle volume but a marked increase in its surface ruggedness. Molecular dynamics simulations using a reactive potential and performed under similar conditions as the experiment reproduce the experimental trends and show in detail how the shape and surface structure of the nanoparticles evolve with increasing oxygen content. This good agreement between in situ observations in the plume and atomistic simulations emphasizes the key role of chemical reactivity together with thermodynamic conditions on the morphology of the particles thus produced.

  14. 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.

  15. Detection of DNA damage induced by heavy ion irradiation in the individual cells with comet assay

    Science.gov (United States)

    Wada, S.; Natsuhori, M.; Ito, N.; Funayama, T.; Kobayashi, Y.

    2003-05-01

    Investigating the biological effects of high-LET heavy ion irradiation at low fluence is important to evaluate the risk of charged particles. Especially it is important to detect radiation damage induced by the precise number of heavy ions in the individual cells. Thus we studied the relationship between the number of ions traversing the cell and DNA damage produced by the ion irradiation. We applied comet assay to measure the DNA damage in the individual cells. Cells attached on the ion track detector CR-39 were irradiated with ion beams at TIARA, JAERI-Takasaki. After irradiation, the cells were stained with ethidium bromide and the opposite side of the CR-39 was etched. We observed that the heavy ions with higher LET values induced the heavier DNA damage. The result indicated that the amount of DNA damage induced by one particle increased with the LET values of the heavy ions.

  16. Structure and tribological properties of modified layer on 2024 aluminum alloy by plasma-based ion implantation with nitrogen/titanium/carbon

    Institute of Scientific and Technical Information of China (English)

    张玲召; 廖家轩; 夏立芳; 刘维民; 徐洮; 薛群基

    2003-01-01

    2024 aluminum alloy was implanted with nitrogen then titanium finally carbon by plasma-based ion implantatio to form a gradient layer.The structure and tribological properties of the layer were investigated.Its composition profiles and chemical states were analyzed with X-ray photoelectron spectroscopy(XPS).The surface carbonlayer was analyzed by Raman spectrum.The appearances were observed by atomic force microscope(AFM).Thesurface hardness was measured with the mechanical property microprobe.The dry wear tests against GCr15 steelball at various sliding loads were performed with a ball-on-disk wear tester in ambient environment.The resultsshow that the thickness of the modified layer is 1 200 nm,the carbon layer is a smooth and compact diamond-likecarbon(DLC)films,and the carbon-titanium interface is broadened due to carbon ions implantation,resulting in agood composition and structure transition between DLC films and titanium layer.Surface hardness is improvedmarkedly,with a slow and uniform change.Tribological properties are improved greatly although they reduce withthe increase of sliding loads because the modified layer becomes thin rapidly.

  17. High Coulombic efficiency aluminum-ion battery using an AlCl3-urea ionic liquid analog electrolyte.

    Science.gov (United States)

    Angell, Michael; Pan, Chun-Jern; Rong, Youmin; Yuan, Chunze; Lin, Meng-Chang; Hwang, Bing-Joe; Dai, Hongjie

    2017-01-31

    In recent years, impressive advances in harvesting renewable energy have led to a pressing demand for the complimentary energy storage technology. Here, a high Coulombic efficiency (∼99.7%) Al battery is developed using earth-abundant aluminum as the anode, graphite as the cathode, and a cheap ionic liquid analog electrolyte made from a mixture of AlCl3 and urea in a 1.3:1 molar ratio. The battery displays discharge voltage plateaus around 1.9 and 1.5 V (average discharge = 1.73 V) and yielded a specific cathode capacity of ∼73 mAh g(-1) at a current density of 100 mA g(-1) (∼1.4 C). High Coulombic efficiency over a range of charge-discharge rates and stability over ∼150-200 cycles was easily demonstrated. In situ Raman spectroscopy clearly showed chloroaluminate anion intercalation/deintercalation of graphite (positive electrode) during charge-discharge and suggested the formation of a stage 2 graphite intercalation compound when fully charged. Raman spectroscopy and NMR suggested the existence of AlCl4(-), Al2Cl7(-) anions and [AlCl2·(urea)n](+) cations in the AlCl3/urea electrolyte when an excess of AlCl3 was present. Aluminum deposition therefore proceeded through two pathways, one involving Al2Cl7(-) anions and the other involving [AlCl2·(urea)n](+) cations. This battery is a promising prospect for a future high-performance, low-cost energy storage device.

  18. Improving the Microstructure and Electrical Properties of Aluminum Induced Polysilicon Thin Films Using Silicon Nitride Capping Layer

    Directory of Open Access Journals (Sweden)

    Min-Hang Weng

    2014-01-01

    Full Text Available We investigated the capping layer effect of SiNx (silicon nitride on the microstructure, electrical, and optical properties of poly-Si (polycrystalline silicon prepared by aluminum induced crystallization (AIC. The primary multilayer structure comprised Al (30 nm/SiNx (20 nm/a-Si (amorphous silicon layer (100 nm/ITO coated glass and was then annealed in a low annealing temperature of 350°C with different annealing times, 15, 30, 45, and 60 min. The crystallization properties were analyzed and verified by X-ray diffraction (XRD and Raman spectra. The grain growth was analyzed via optical microscope (OM and scanning electron microscopy (SEM. The improved electrical properties such as Hall mobility, resistivity, and dark conductivity were investigated by using Hall and current-voltage (I-V measurements. The results show that the amorphous silicon film has been effectively induced even at a low temperature of 350°C and a short annealing time of 15 min and indicate that the SiNx capping layer can improve the grain growth and reduce the metal content in the induced poly-Si film. It is found that the large grain size is over 20 μm and the carrier mobility values are over 80 cm2/V-s.

  19. Hydrogen-rich water alleviates aluminum-induced inhibition of root elongation in alfalfa via decreasing nitric oxide production.

    Science.gov (United States)

    Chen, Meng; Cui, Weiti; Zhu, Kaikai; Xie, Yanjie; Zhang, Chunhua; Shen, Wenbiao

    2014-02-28

    One of the earliest and distinct symptoms of aluminum (Al) toxicity is the inhibition of root elongation. Although hydrogen gas (H2) is recently described as an important bio-regulator in plants, whether and how H2 regulates Al-induced inhibition of root elongation is largely unknown. To address these gaps, hydrogen-rich water (HRW) was used to investigate a physiological role of H2 and its possible molecular mechanism. Individual or simultaneous (in particular) exposure of alfalfa seedlings to Al, or a fresh but not old nitric oxide (NO)-releasing compound sodium nitroprusside (SNP), not only increased NO production, but also led to a significant inhibition of root elongation. Above responses were differentially alleviated by pretreatment with 50% saturation of HRW. The addition of HRW also alleviated the appearance of Al toxicity symptoms, including the improvement of seedling growth and less accumulation of Al. Subsequent results revealed that the removal of NO by the NO scavenger, similar to HRW, could decrease NO production and alleviate Al- or SNP-induced inhibition of root growth. Thus, we proposed that HRW alleviated Al-induced inhibition of alfalfa root elongation by decreasing NO production. Such findings may be applicable to enhance crop yield and improve stress tolerance. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Ion-induced gammas for photofission interrogation of HEU.

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Barney Lee (Sandia National Laboratories, Albuquerque, NM); Antolak, Arlyn J.; Morse, Daniel H.; Provencio, Paula Polyak (Sandia National Laboratories, Albuquerque, NM)

    2006-03-01

    High-energy photons and neutrons can be used to actively interrogate for heavily shielded special nuclear material (SNM), such as HEU (highly enriched uranium), by detecting prompt and/or delayed induced fission signatures. In this work, we explore the underlying physics for a new type of photon source that generates high fluxes of mono-energetic gamma-rays from low-energy (<500 keV) proton-induced nuclear reactions. The characteristic energies (4- to 18-MeV) of the gamma-rays coincide with the peak of the photonuclear cross section. The source could be designed to produce gamma-rays of certain selected energies, thereby improving the probability of detecting shielded HEU or providing a capability to determine enrichment inside sealed containers. The fundamental physics of such an interrogation source were studied in this LDRD through scaled ion accelerator experiments and radiation transport modeling. The data were used to assess gamma and neutron yields, background, and photofission-induced signal levels from several (p,{gamma}) target materials under consideration.

  1. Incoherent twin boundary migration induced by ion irradiation in Cu

    Energy Technology Data Exchange (ETDEWEB)

    Li, N.; Misra, A. [Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Wang, J.; Wang, Y. Q. [Materials Science and Technology Division, MST-8, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Serruys, Y. [CEA, DEN, Service de Recherches de Metallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Nastasi, M. [Nebraska Center for Energy Sciences Research, University of Nebraska, Lincoln, Nebraska 68588 (United States)

    2013-01-14

    Grain boundaries can act as sinks for radiation-induced point defects. The sink capability is dependent on the atomic structures and varies with the type of point defects. Using high-resolution transmission electron microscopy, we observed that {Sigma}3{l_brace}112{r_brace} incoherent twin boundary (ITB) in Cu films migrates under Cu{sup 3+} ion irradiation. Using atomistic modeling, we found that {Sigma}3{l_brace}112{r_brace} ITB has the preferred sites for adsorbing interstitials and the preferential diffusion channels along the Shockley partial dislocations. Coupling with the high mobility of grain boundary Shockley dislocations within {Sigma}3{l_brace}112{r_brace} ITB, we infer that {Sigma}3{l_brace}112{r_brace} ITB migrates through the collective glide of grain boundary Shockley dislocations, driven by a concurrent reduction in the density of radiation-induced defects, which is demonstrated by the distribution of nearby radiation-induced defects.

  2. Recent studies in heavy ion induced fission reactions

    Indian Academy of Sciences (India)

    R K Choudhury

    2001-08-01

    Nuclear fission process involves large scale shape changes of the nucleus, while it evolves from a nearly spherical configuration to two separated fission fragments. The dynamics of these shape changes in the nuclear many body system is governed by a strong interplay of the collective and single particle degrees of freedom. With the availability of heavy ion accelerators, there has been an impetus to study the nuclear dynamics through the investigations of nucleus–nucleus collisions involving fusion and fission process. From the various investigations carried out in the past years, it is now well recognized that there is large scale damping of collective modes in heavy ion induced fission reactions, which in other words implies that nuclear motion is highly viscous. In recent years, there have been many experimental observations in heavy ion induced fission reactions at medium bombarding energies, which suggest possible occurrence of various non-equilibrium modes of fission such as quasi-fission, fast fission and pre-equilibrium fission, where some of the internal degrees of freedom of the nucleus is not fully equilibrated. We have carried out extensive investigations on the fission fragment angular distributions at near barrier bombarding energies using heavy fissile targets. The measured fragment anisotropies when compared with the standard saddle point model (SSPM) calculations show that for projectile-target systems having zero or low ground state spins, the angular anisotropy exhibits a peak-like behaviour at the sub barrier energies, which cannot be explained by the SSPM calculations. For projectiles or targets with large ground state spins, the anomalous peaking gets washed out due to smearing of the -distribution by the intrinsic entrance channel spins. Recently studies have been carried out on the spin distributions of fission fragments through the gamma ray multiplicity measurements. The fission fragments acquire spin mainly from two

  3. Potential protective effects of extra virgin olive oil on the hepatotoxicity induced by co-exposure of adult rats to acrylamide and aluminum.

    Science.gov (United States)

    Ghorbel, Imen; Elwej, Awatef; Jamoussi, Kamel; Boudawara, Tahia; Kamoun, Naziha Grati; Zeghal, Najiba

    2015-04-01

    Extra virgin olive oil has been shown to be effective against oxidative stress associated diseases. In addition to the high quantities of oleic acid, it is rich in phenolic compounds. We investigated the protective efficacy of extra virgin olive oil (EVOO) against the hepatotoxicity induced by both aluminum and acrylamide. Animals were divided into four groups containing six rats each: group 1, serving as controls, received distilled water; group 2 received drinking water containing aluminum chloride (50 mg kg(-1) body weight) and acrylamide (20 mg kg(-1) body weight) by gavage; group 3 received both aluminum and acrylamide in the same ways as well as EVOO (300 μl) by gavage; group 4 received only EVOO by gavage for 3 weeks. The rats exposed to both aluminum and acrylamide exhibited oxidative stress observed by an increase in MDA, AOPP and a decrease in GSH, NPSH and vitamin C levels. The activities of CAT and GPx were decreased, while SOD activity was increased. The liver metallothioneins, such as MT1 and MT2 genes expression, were also increased. EVOO supplementation improved all the parameters mentioned above. The plasma transaminases (AST and ALT), LDH activities, glucose and albumin levels, TC, LDL-C levels, TC/HDL-C and LDL-C/HDL-C ratios were increased, while high density lipoprotein-cholesterol (HDL-C) and TG decreased. The co-administration of EVOO to acrylamide and aluminum treated rats restored their hepatic markers to near-normal values. Liver histological studies confirmed the biochemical parameters and the beneficial role of EVOO. These results suggest that extra virgin olive oil, when added to the diet, may have a beneficial role in decreasing the liver damage induced by both aluminum and acrylamide.

  4. Plasma-ion Induced Sputtering and Heating of Titan's Atmosphere

    Science.gov (United States)

    Johnson, R. E.; Tucker, O. J.

    2007-05-01

    Titan is unique among the outer solar system icy satellites in having an atmosphere with a column density about ten times that of the Earth's atmosphere and an atmospheric mass to solid mass ratio comparable to that of Venus. Atmospheres equivalent in size to that at Titan would have been removed from the icy Galilean satellites by the plasma trapped in the Jovian magnetosphere (Johnson 2004). Therefore, the use of Cassini data to determine the present erosion rate of Titan's atmosphere provides an important end point for studying the erosion and heating of planetary and satellite atmospheres by an ambient plasma. In this paper we describe the deposition of energy, the erosion and the expansion of the upper atmosphere of Titan using Direct Simulation Monte Carlo models (Shematovich et al. 2003; Michael et al. 2005; Michael and Johnson 2005). These calculations are used to calibrate semi-empirical models of atmospheric sputtering (Johnson 1994) that are used to interpret Cassini data at Titan. Using a number of plasma conditions, the temperature and density vs. altitude above the exobase and the rate of escape are calculated. References: Johnson, R.E. "Plasma-induced Sputtering of an Atmosphere" in Space Science Reviews 69 215-253 (1994). Johnson. R.E., " The magnetospheric plasmadriven evolution of satellite atmospheres" Astrophys. J. 609, L99-L102 (2004). Michael, M. and R.E. Johnson, "Energy deposition of pickup ions and heating of Titan's atmosphere", Planetary & Space Sci.53, 1510-1514 (2005). Michael M., R.E. Johnson, F. Leblanc, M. Liu, J.G. Luhmann, and V.I. Shematovich, "Ejection of nitrogen from Titan's atmosphere by magnetospheric ions and pick-up ions", Icarus 175, 263-267 (2005). Shematovich, V.I., R.E. Johnson, M. Michael, and J.G. Luhmann, "Nitrogen loss from Titan", JGR 108, No. E8, 5087, doi:10.1029/2003JE002094 (2003).

  5. Heavy ion induced double strand breaks in bacteria and bacteriophages

    Science.gov (United States)

    Micke, U.; Schäfer, M.; Anton, A.; Horneck, G.; Bücker, H.

    DNA damage induced by heavy ions in bacterial cells and bacteriophages such as Bacillus subtilis, E. coli and Bacteriophage Tl were investigated by analyzing the double strand breaks in the chromosomal DNA. This kind of lesion is considered as one of the main reasons for lethal events. To analyze double strand breaks in long molecules of DNA - up to some Mbp in length - the technique of pulse field agarose gel electrophoresis has been used. This allows the detection of one double strand break per genome. Cell lysis and DNA isolation were performed in small agarose blocks directly. This procedure secured minimum DNA destruction by shearing forces. After running a gel, the DNA was stained with ethidium bromide. The light intensity of ethidium bromide fluorescence for both the outcoming (running) DNA and the remaining intact DNA were measured by scanning. The mean number of double strand breaks was calculated by determining the quotient of these intensities. Strand break induction after heavy ion and X-ray irradiation was compared.

  6. Cluster-jet targets for laser induced ion acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Grieser, S.; Bonaventura, D.; Hergemoeller, A.K.; Koehler, E.; Taeschner, A.; Khoukaz, A. [Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet Muenster (Germany); Buescher, M.; Schlueter, F. [Peter Gruenberg Institut (PGI), FZ Juelich (Germany); Engin, I. [Institut fuer Kernphysik, (IKP), FZ Juelich (Germany)

    2014-07-01

    The directed ion acceleration induced by high-energy laser pulses is a strongly increasing research field. In such experiments ultra-short laser pulses focussed on a target create a plasma, in which strong secondary electric fields can accelerate protons and ions to multi-MeV energies. A major drawback of the commonly used targets, like gas-jets or foils, is their low density or the need to be replaced after each laser pulse. An innovative perspective for high-flux and high-repetition-rate experiments is the application of a cluster-jet source, which continuously produces a flux of cryogenic solid clusters by the expansion of pre-cooled gases within fine Laval nozzles. Therefore, a cluster-jet target was built up and set successfully into operation at the University of Muenster and will be used for experiments on laser and plasma physics at the University of Duesseldorf. Systematic measurements were done to determine the target beam thickness, possible beam structures, the stability, and the position within the scattering chamber to ensure the ideal requirements for the experiments. For this purpose, the cluster beam was illuminated by a diode laser 33 cm behind the Laval nozzle and observed by a CCD camera. The results on the cluster beam properties are presented and discussed.

  7. Ion Induced Changes in Phosphoinositide Monolayers at Phisiological Concentrations

    Science.gov (United States)

    Kazadi Badiambile, Adolphe; Forstner, Martin

    2013-03-01

    Phosphoinositides (PIPs) play a crucial role in many cellular process that occur at the plasma membrane such as calcium release, exocytosis or endocytosis. In order to specifically regulate these functions PIPs must segregate in pools at the plasma membrane. A possible mechanism that could induce and regulate such organization of phosphoinositides is their interaction with bivalent cations. Understanding the physicochemical mechanism that can regulate membrane structure is a crucial step in the development of adaptive biomimetic membrane systems. Using Langmuir monolayers, we investigated the effect of calcium and magnesium on the surface pressure-area/lipid isotherm of monolayer of phosphatidylinositol (PI), phosphatidylinositol bisphosphate (PIP2), dioleoylphosphatidylglycerol (DOPG) and palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). It is found that the decrease of area per lipid, i.e. the increase in aggregation, is mostly dependent on the lipid's head group charge but ion specific. In addition, we discuss changes in free energy and compressibility of these monolayer-ion systems. NSF

  8. Folic Acid Protected Neural Cells Against Aluminum-Maltolate-Induced Apoptosis by Preventing miR-19 Downregulation.

    Science.gov (United States)

    Zhu, Mingming; Li, Bingfei; Ma, Xiao; Huang, Cong; Wu, Rui; Zhu, Weiwei; Li, Xiaoting; Liang, Zhaofeng; Deng, Feifei; Zhu, Jianyun; Xie, Wei; Yang, Xue; Jiang, Ye; Wang, Shijia; Wu, Jieshu; Geng, Shanshan; Xie, Chunfeng; Zhong, Caiyun; Liu, Haiyan

    2016-08-01

    Aluminum (Al)-induced apoptosis is considered as the major cause of its neurotoxicity. Folic acid possesses neuroprotective function by preventing neural cell apoptosis. microRNAs (miRNAs) are important regulators of gene expression participating in cellular processes. As a key component of the miR-17-92 cluster, miR-19 is implicated in regulating apoptotic process, while its role in the neuroprotective effect of folic acid has not been investigated. The present study aimed to investigate the potential involvement and function of miR-19 in the protective action of folic acid against Al-induced neural cell apoptosis. Human SH-SY5Y cells were treated with Al-maltolate (Al-malt) in the presence or absence of folic acid. Results showed that Al-malt-induced apoptosis of SH-SY5Y cells was effectively prevented by folic acid. Al-malt suppressed the expression of miR-19a/19b, along with alterations of miR-19 related apoptotic proteins including PTEN, p-AKT, p53, Bax, Bcl-2, caspase 9 and caspase 3; and these effects were ameliorated by folic acid. miR-19 inhibitor alone induced apoptosis of SH-SY5Y cells. Combination treatment of folic acid and miR-19 inhibitor diminished the neuroprotective effect of folic acid. These findings demonstrated that folic acid protected neuronal cells against Al-malt-induced apoptosis by preventing the downregulation of miR-19 and modulation of miR-19 related downstream PTEN/AKT/p53 pathway.

  9. Swift heavy ion induced modification of aliphatic polymers

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Umme Habiba

    2015-01-15

    In this thesis, the high energy heavy ion induced modification of aliphatic polymers is studied. Two polymer groups, namely polyvinyl polymers (PVF, PVAc, PVA and PMMA) and fluoropolymers (PVDF, ETFE, PFA and FEP) were used in this work. Polyvinyl polymers were investigated since they will be used as insulating materials in the superconducting magnets of the new ion accelerators of the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz-Centre of Heavy Ion Research (GSI) in Darmstadt. In order to study ion-beam induced degradation, all polymer foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (U, Au, Sm, Xe) and experimentation sites (beam lines X0 and M3) over a large fluence regime (1 x 10{sup 10} - 5 x 10{sup 12} ions/cm{sup 2}). Five independent techniques, namely infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopy, residual gas analysis (RGA), thermal gravimetric analysis (TGA), and mass loss analysis (ML), were used to analyze the irradiated samples. FT-IR spectroscopy revealed that ion irradiation led to the decrease of characteristic band intensities showing the general degradation of the polymers, with scission of side groups and the main backbone. As a consequence of the structural modification, new bands appeared. UV-Vis transmission analysis showed an absorption edge shift from the ultraviolet region towards the visible region indicating double bond and conjugated double bond formation. On-line massspectrometric residual gas analysis showed the release of small gaseous fragment molecules. TGA analysis gave evidence of a changed thermal stability. With ML analysis, the considerable mass loss was quantified. The results of the five complementary analytical methods show how heavy ion irradiation changes the molecular structure of the polymers. Molecular degradation mechanisms are postulated. The amount of radiation damage is found to be sensitive to the used type of ionic

  10. P-type poly-Si prepared by low-temperature aluminum-induced crystallization and doping for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yasuhiro; Yu, Zhenrui; Morales-Acevedo, Arturo [CINVESTAV-IPN, Mexico, D.F. (Mexico)

    2000-07-01

    P-type poly-Si thin films prepared by low temperature aluminum-induced crystallization and doping are reported. The starting material was boron-doped a-Si:H prepared by PECVD on glass substrates. Aluminum layers with different thickness were evaporated on a-Si:H surface and conventional thermal annealing was performed at temperatures ranging from 300 to 550 Celsius degrees. XRD, SIMS, and Hall effect measurements were carried out to characterize the annealed Al could be crystallized at temperature as low as 300 Celsius degrees in 60 minutes. This material has high carrier concentration as well as high Hall mobility and can be used as a p-layer of seed layer for thin film poly-Si solar cells. The technique reported here is compatible with PECVD process. [Spanish] Se informa sobre la preparacion de peliculas delgadas tipo P y Poli-Si mediante la cristalizacion inducida de aluminio a baja temperatura y el dopado. El material inicial era de boro dopado y a-Si:H preparado PECVD sobre substratos de vidrio. Se evaporaron capas de aluminio de diferente espesor sobre una superficie de a-Si:H y se llevo a cabo un destemplado termico convencional a temperaturas que varian entre 300 y 500 grados Celsius. Se llevaron a cabo mediciones de XRB, SIMS y del efecto Hall para caracterizar el aluminio destemplado para que pudiera ser cristalizado a temperaturas tan bajas como 300 grados Celsius en 60 minutos. Este material tiene una alta concentracion portadora asi como una alta movilidad Hall y puede usarse como una capa de semilla para celdas solares de pelicula delgada Poli-Si. La tecnica reportada aqui es compatible con el proceso PECVD.

  11. Aluminum-Ion-Intercalation Supercapacitors with Ultrahigh Areal Capacitance and Highly Enhanced Cycling Stability: Power Supply for Flexible Electrochromic Devices.

    Science.gov (United States)

    Li, Kerui; Shao, Yuanlong; Liu, Shiyi; Zhang, Qinghong; Wang, Hongzhi; Li, Yaogang; Kaner, Richard B

    2017-05-01

    Electrochemical capacitor systems based on Al ions can offer the possibilities of low cost and high safety, together with a three-electron redox-mechanism-based high capacity, and thus are expected to provide a feasible solution to meet ever-increasing energy demands. Here, highly efficient Al-ion intercalation into W18 O49 nanowires (W18 O49 NWs) with wide lattice spacing and layered single-crystal structure for electrochemical storage is demonstrated. Moreover, a freestanding composite film with a hierarchical porous structure is prepared through vacuum-assisted filtration of a mixed dispersion containing W18 O49 NWs and single-walled carbon nanotubes. The as-prepared composite electrode exhibits extremely high areal capacitances of 1.11-2.92 F cm(-2) and 459 F cm(-3) at 2 mA cm(-2) , enhanced electrochemical stability in the Al(3+) electrolyte, as well as excellent mechanical properties. An Al-ion-based, flexible, asymmetric electrochemical capacitor is assembled that displays a high volumetric energy density of 19.0 mWh cm(-3) at a high power density of 295 mW cm(-3) . Finally, the Al-ion-based asymmetric supercapacitor is used as the power source for poly(3-hexylthiophene)-based electrochromic devices, demonstrating their promising capability in flexible electronic devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Expanded graphite embedded with aluminum nanoparticles as superior thermal conductivity anodes for high-performance lithium-ion batteries.

    Science.gov (United States)

    Zhao, Tingkai; She, Shengfei; Ji, Xianglin; Guo, Xinai; Jin, Wenbo; Zhu, Ruoxing; Dang, Alei; Li, Hao; Li, Tiehu; Wei, Bingqing

    2016-09-27

    The development of high capacity and long-life lithium-ion batteries is a long-term pursuing and under a close scrutiny. Most of the researches have been focused on exploring electrode materials and structures with high store capability of lithium ions and at the same time with a good electrical conductivity. Thermal conductivity of an electrode material will also have significant impacts on boosting battery capacity and prolonging battery lifetime, which is, however, underestimated. Here, we present the development of an expanded graphite embedded with Al metal nanoparticles (EG-MNPs-Al) synthesized by an oxidation-expansion process. The synthesized EG-MNPs-Al material exhibited a typical hierarchical structure with embedded Al metal nanoparticles into the interspaces of expanded graphite. The parallel thermal conductivity was up to 11.6 W·m(-1)·K(-1) with a bulk density of 453 kg·m(-3) at room temperature, a 150% improvement compared to expanded graphite (4.6 W·m(-1)·K(-1)) owing to the existence of Al metal nanoparticles. The first reversible capacity of EG-MNPs-Al as anode material for lithium ion battery was 480 mAh·g(-1) at a current density of 100 mA·g(-1), and retained 84% capacity after 300 cycles. The improved cycling stability and system security of lithium ion batteries is attributed to the excellent thermal conductivity of the EG-MNPs-Al anodes.

  13. Expanded graphite embedded with aluminum nanoparticles as superior thermal conductivity anodes for high-performance lithium-ion batteries

    Science.gov (United States)

    Zhao, Tingkai; She, Shengfei; Ji, Xianglin; Guo, Xinai; Jin, Wenbo; Zhu, Ruoxing; Dang, Alei; Li, Hao; Li, Tiehu; Wei, Bingqing

    2016-09-01

    The development of high capacity and long-life lithium-ion batteries is a long-term pursuing and under a close scrutiny. Most of the researches have been focused on exploring electrode materials and structures with high store capability of lithium ions and at the same time with a good electrical conductivity. Thermal conductivity of an electrode material will also have significant impacts on boosting battery capacity and prolonging battery lifetime, which is, however, underestimated. Here, we present the development of an expanded graphite embedded with Al metal nanoparticles (EG-MNPs-Al) synthesized by an oxidation-expansion process. The synthesized EG-MNPs-Al material exhibited a typical hierarchical structure with embedded Al metal nanoparticles into the interspaces of expanded graphite. The parallel thermal conductivity was up to 11.6 W·m-1·K-1 with a bulk density of 453 kg·m-3 at room temperature, a 150% improvement compared to expanded graphite (4.6 W·m-1·K-1) owing to the existence of Al metal nanoparticles. The first reversible capacity of EG-MNPs-Al as anode material for lithium ion battery was 480 mAh·g-1 at a current density of 100 mA·g-1, and retained 84% capacity after 300 cycles. The improved cycling stability and system security of lithium ion batteries is attributed to the excellent thermal conductivity of the EG-MNPs-Al anodes.

  14. Aluminum-Induced Entropy in Biological Systems: Implications for Neurological Disease

    Directory of Open Access Journals (Sweden)

    Christopher A. Shaw

    2014-01-01

    Full Text Available Over the last 200 years, mining, smelting, and refining of aluminum (Al in various forms have increasingly exposed living species to this naturally abundant metal. Because of its prevalence in the earth’s crust, prior to its recent uses it was regarded as inert and therefore harmless. However, Al is invariably toxic to living systems and has no known beneficial role in any biological systems. Humans are increasingly exposed to Al from food, water, medicinals, vaccines, and cosmetics, as well as from industrial occupational exposure. Al disrupts biological self-ordering, energy transduction, and signaling systems, thus increasing biosemiotic entropy. Beginning with the biophysics of water, disruption progresses through the macromolecules that are crucial to living processes (DNAs, RNAs, proteoglycans, and proteins. It injures cells, circuits, and subsystems and can cause catastrophic failures ending in death. Al forms toxic complexes with other elements, such as fluorine, and interacts negatively with mercury, lead, and glyphosate. Al negatively impacts the central nervous system in all species that have been studied, including humans. Because of the global impacts of Al on water dynamics and biosemiotic systems, CNS disorders in humans are sensitive indicators of the Al toxicants to which we are being exposed.

  15. Nitric oxide alleviates aluminum-induced oxidative damage through regulating the ascorbate-glutathione cycle in roots of wheat

    Institute of Scientific and Technical Information of China (English)

    Chengliang Sun; Lijuan Liu; Yan Yu; Wenjing Liu; Lingli Lu; Chongwei Jin; Xianyong Lin

    2015-01-01

    The possible association with nitric oxide (NO) and ascorbate-glutathione (AsA-GSH) cycle in regulating aluminum (Al) tolerance of wheat (Triticum aestivum L.) was investigated using two genotypes with different Al resistance. Exposure to Al inhibited root elongation, and triggered lipid peroxidation and oxidation of AsA to dehydroascorbate and GSH to glutathione disulfide in wheat roots. Exogenous NO significantly increased endogenous NO levels, and subsequently al eviated Al-induced inhibition of root elongation and oxidation of AsA and GSH to maintain the redox molecules in the reduced form in both wheat genotypes. Under Al stress, significantly increased activities and gene transcriptional levels of ascorbate peroxi-dase, glutathione reductase, and dehydroascorbate reductase, were observed in the root tips of the Al-tolerant genotype Jian-864. Nitric oxide application enhanced the activity and gene transcriptional level of these enzymes in both wheat geno-types. g-Glutamylcysteine synthetase was not significantly affected by Al or NO, but NO treatments increased the activity of glutathione peroxidase and glutathione S-transferase to a greater extent than the Al-treated wheat seedlings. Proline was significantly decreased by Al, while it was not affected by NO. These results clearly suggest that NO protects wheat root against Al-induced oxidative stress, possibly through its regulation of the AsA-GSH cycle.

  16. Aluminum induces neurodegeneration and its toxicity arises from increased iron accumulation and reactive oxygen species (ROS) production.

    Science.gov (United States)

    Wu, Zhihao; Du, Yumei; Xue, Hua; Wu, Yongsheng; Zhou, Bing

    2012-01-01

    The neurotoxicity of aluminum (Al) - the most abundant metal element on earth - has been known for years. However, the mechanism of Al-induced neurodegeneration and its relationship to Alzheimer's disease are still controversial. In particular, in vivo functional data are lacking. In a Drosophila model with chronic dietary Al overloading, general neurodegeneration and several behavioral changes were observed. Al-induced neurodegeneration is independent of β-amyloid or tau-associated toxicity, suggesting they act in different molecular pathways. Interestingly, Drosophila frataxin (dfh), which causes Friedreich's ataxia if mutated in humans, displayed an interacting effect with Al, suggesting Friedreich's ataxia patients might be more susceptible to Al toxicity. Al-treated flies accumulated large amount of iron and reactive oxygen species (ROS), and exhibited elevated SOD2 activity. Genetic and pharmacological efforts to reduce ROS or chelate excess Fe significantly mitigated Al toxicity. Our results indicate that Al toxicity is mediated through ROS production and iron accumulation and suggest a remedial route to reduce toxicity due to Al exposure.

  17. The simultaneous removal of calcium, magnesium and chloride ions from industrial wastewater using magnesium-aluminum oxide.

    Science.gov (United States)

    Hamidi, Roya; Kahforoushan, Davood; Fatehifar, Esmaeil

    2013-01-01

    In this article, a method for simultaneous removal of calcium, magnesium and chloride by using Mg0.80Al0.20O1.10 as a Magnesium-Aluminum oxide (Mg‒Al oxide) was investigated. Mg‒Al oxide obtained by thermal decomposition of the Mg-Al layered double hydroxide (Mg-Al LDH). The synthesized Mg‒Al oxide were characterized with respect to nitrogen physicosorption, X-ray diffraction (XRD) and field emission scan electron microscopy (FESEM) morphology. Due to high anion-exchange capacity of Mg‒Al oxide, it was employed in simultaneously removal of Cl(-), Mg(+2) and Ca(+2) from distiller waste of a sodium carbonate production factory. For this purpose, experiments were designed to evaluate the effects of quantity of Mg‒Al oxide, temperature and time on the removal process. The removal of Cl(-), Mg(+2) and Ca(+2) from wastewater was found 93.9%, 93.74% and 93.25% at 60°C after 0.5 h, respectively. Results showed that the removal of Cl(-), Mg(+2) and Ca(+2) by Mg‒Al oxide increased with increasing temperature, time and Mg‒Al oxide quantity.

  18. A High Efficiency Aluminum-Ion Battery Using an AlCl3-Urea Ionic Liquid Analogue Electrolyte

    CERN Document Server

    Angell, Michael; Rong, Youmin; Yuan, Chunze; Lin, Meng-Chang; Hwang, BingJoe; Dai, Hongjie

    2016-01-01

    In recent years, impressive advances in harvesting renewable energy have led to pressing demand for the complimentary energy storage technology. Here, a high coulombic efficiency (~ 99.7%) Al battery is developed using earth-abundant aluminum as the anode, graphite as the cathode, and a cheap ionic liquid analogue electrolyte made from a mixture of AlCl3 and urea in 1.3 : 1 molar ratio. The battery displays discharge voltage plateaus around 1.9 V and 1.5 V (average discharge = 1.73 V) and yielded a specific cathode capacity of ~73 mAh g-1 at a current density of 100 mA g-1 (~ 1.4 C). High coulombic efficiency over a range of charge-discharge rates and stability over ~150-200 cycles was easily demonstrated. In-situ Raman spectroscopy clearly showed chloroaluminate anion intercalation/deintercalation of graphite in the cathode side during charge/discharge and suggested the formation of a stage 2 graphite intercalation compound when fully charged. Raman spectroscopy and nuclear magnetic resonance suggested the e...

  19. Up-regulation of heme oxygenase-1 contributes to the amelioration of aluminum-induced oxidative stress in Medicago sativa.

    Science.gov (United States)

    Cui, Weiti; Zhang, Jing; Xuan, Wei; Xie, Yanjie

    2013-10-15

    In this report, pharmacological, histochemical and molecular approaches were used to investigate the effect of heme oxygenase-1 (HO-1) up-regulation on the alleviation of aluminum (Al)-induced oxidative stress in Medicago sativa. Exposure of alfalfa to AlCl3 (0-100 μM) resulted in a dose-dependent inhibition of root elongation as well as the enhancement of thiobarbituric acid reactive substances (TBARS) content. 1 and 10 μM (in particular) Al(3+) increased alfalfa HO-1 transcript or its protein level, and HO activity in comparison with the decreased changes in 100 μM Al-treated samples. After recuperation, however, TBARS levels in 1 and 10 μM Al-treated alfalfa roots returned to control values, which were accompanied with the higher levels of HO activity. Subsequently, exogenous CO, a byproduct of HO-1, could substitute for the cytoprotective effects of the up-regulation of HO-1 in alfalfa plants upon Al stress, which was confirmed by the alleviation of TBARS and Al accumulation, as well as the histochemical analysis of lipid peroxidation and loss of plasma membrane integrity. Theses results indicated that endogenous CO generated via heme degradation by HO-1 could contribute in a critical manner to its protective effects. Additionally, the pretreatments of butylated hydroxytoluene (BHT) and hemin, an inducer of HO-1, exhibited the similar cytoprotective roles in the alleviation of oxidative stress, both of which were impaired by the potent inhibitor of HO-1, zinc protoporphyrin IX (ZnPP). However, the Al-induced inhibition of root elongation was not influenced by CO, BHT and hemin, respectively. Together, the present results showed up-regulation of HO-1 expression could act as a mechanism of cell protection against oxidative stress induced by Al treatment.

  20. Mitochondrial dysfunction induced by different concentrations of gadolinium ion.

    Science.gov (United States)

    Zhao, Jie; Zhou, Zhi-Qiang; Jin, Jian-Cheng; Yuan, Lian; He, Huan; Jiang, Feng-Lei; Yang, Xiao-Gang; Dai, Jie; Liu, Yi

    2014-04-01

    Gadolinium-based compounds are the most widely used paramagnetic contrast agents in magnetic resonance imaging on the world. But the tricationic gadolinium ion (Gd(3+)) could induce cell apoptosis probably because of its effects on mitochondria. Until now, the mechanism about how Gd(3+) interacts with mitochondria is not well elucidated. In this work, mitochondrial swelling, collapsed transmembrane potential and decreased membrane fluidity were observed to be important factors for mitochondrial permeability transition pore (mtPTP) opening induced by Gd(3+). The protection effect of CsA (Cyclosporin A) could confirm high concentration of Gd(3+) (500 μM) would trigger mtPTP opening. Moreover, mitochondrial outer membrane breakdown and volume expansion observed clearly by transmission electron microscopy and the release of Cyt c (Cytochrome c) could explain the mtPTP opening from another aspect. In addition, MBM(+) (monobromobimane(+)) and DTT (dithiothreitol) could protect thiol (-SH) groups from oxidation so that the toxicity of Gd(3+) might be resulted from the chelation of -SH of membrane proteins by free Gd(3+). Gd(3+) could inhibit the initiation of mitochondrial membrane lipid peroxidation, so it might interact with anionic lipids too. These findings will highly contribute to the safe applications of Gd-based agents.

  1. Expanded graphite embedded with aluminum nanoparticles as superior thermal conductivity anodes for high-performance lithium-ion batteries

    Science.gov (United States)

    Zhao, Tingkai; She, Shengfei; Ji, Xianglin; Guo, Xinai; Jin, Wenbo; Zhu, Ruoxing; Dang, Alei; Li, Hao; Li, Tiehu; Wei, Bingqing

    2016-01-01

    The development of high capacity and long-life lithium-ion batteries is a long-term pursuing and under a close scrutiny. Most of the researches have been focused on exploring electrode materials and structures with high store capability of lithium ions and at the same time with a good electrical conductivity. Thermal conductivity of an electrode material will also have significant impacts on boosting battery capacity and prolonging battery lifetime, which is, however, underestimated. Here, we present the development of an expanded graphite embedded with Al metal nanoparticles (EG-MNPs-Al) synthesized by an oxidation-expansion process. The synthesized EG-MNPs-Al material exhibited a typical hierarchical structure with embedded Al metal nanoparticles into the interspaces of expanded graphite. The parallel thermal conductivity was up to 11.6 W·m−1·K−1 with a bulk density of 453 kg·m−3 at room temperature, a 150% improvement compared to expanded graphite (4.6 W·m−1·K−1) owing to the existence of Al metal nanoparticles. The first reversible capacity of EG-MNPs-Al as anode material for lithium ion battery was 480 mAh·g−1 at a current density of 100 mA·g−1, and retained 84% capacity after 300 cycles. The improved cycling stability and system security of lithium ion batteries is attributed to the excellent thermal conductivity of the EG-MNPs-Al anodes. PMID:27671848

  2. Crystallization of calcium sulfate dihydrate under simulated conditions of phosphoric acid production in the presence of aluminum and magnesium ions

    Science.gov (United States)

    Rashad, M. M.; Mahmoud, M. H. H.; Ibrahim, I. A.; Abdel-Aal, E. A.

    2004-06-01

    The effect of Al 3+ and Mg 2+ ions, as additives, on the crystallization of gypsum was studied under simulated conditions of the phosphoric acid production. Calcium hydrogen phosphate and sulfuric acid were mixed with dilute phosphoric acid at 80°C, and the turbidity of the reaction mixture was measured at different time periods to calculate the induction time of gypsum crystals formation. Addition of Al 3+ ions up to 2% decreased the induction time and increased the growth efficiency while addition of Mg 2+ increased the induction time and decreased the growth efficiency compared with in absence of additives. Interestingly, the crystals mean and median diameters were found to increase in the presence of Al 3+ and decrease in the presence of Mg 2+. The surface energy increased with Al 3+ and decreased with Mg 2+ compared to the baseline (without additives). Gypsum morphology changed from needle-like type in absence of additives to thick-rhombic in the presence of Al 3+ ions.

  3. Proteome modification in tomato plants upon long-term aluminum treatment

    Science.gov (United States)

    This study aimed to identify the aluminum (Al)-induced proteomes in tomato (Solanum lycopersicum, “Micro-Tom”) after long-term exposure to the stress factor. Plants were treated in Magnavaca’s solution (pH 4.5) supplemented with 7.5 uM Al3+ ion activity over a 4 month period beginning at the emergen...

  4. Camel's Milk Protects against Aluminum Chloride-Induced Toxicity in the Liver and Kidney of White Albino Rats

    Directory of Open Access Journals (Sweden)

    Fahaid Al-Hashem

    2009-01-01

    Full Text Available Problem statement: Aluminum chloride (AlCl3 is commonly used in daily life but it can be potentially toxic. Therefore, the present study was carried out to investigate the protective effects of camel' milk against aluminum-induced biochemical alterations and oxidative stress in the liver and kidney of white albino rats. Approach: White albino male rats (230-250 g were divided into three groups of 10 rats: a control group treated with normal saline, the AlCl3-treated group and the camel's milk-AlCl3-treated group. The AlCl3 treated group received 0.5 mg kg-1 of AlCl3 orally. The camel's milk-AlCl3-treated group was fed 1 mL of fresh camel's milk 10 minutes prior to the administration of oral AlCl3. All rats were treated every day for 30 days. Liver and kidney biochemical serum parameters were analyzed. Lipid peroxidation, as determined by the tissue concentrations of thiobarbituric acid reactive substances (TBARS and hydrogen peroxide (HP, and the oxidative stress status, as measured by glutathione (GSH, superoxide dismutase (SOD and catalase (CAT activity, were evaluated in the kidney and liver of treated rats. Results: Data showed that the oral administration of AlCl3 resulted in statistically significant increases in the serum levels of urea, creatinine, bilirubin, aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, lactate dehydrogenase (LDH, cholesterol and triglycerides; the total amount of protein and albumin were also significantly decreased. However, these parameters were within normal levels in the rats given camel's milk prior to AlCl3. Additionally, oral administration of AlCl3 induced lipid peroxidation in the liver and kidney, which was indicated by a significant increase in lipid peroxidation biomarkers (TBARS and HP and a significant decrease in the activities of GSH, SOD and CAT. In all rats treated with camel's milk before being given AlCl3, lipid peroxidation and oxidative stress

  5. Therapeutic effect of taurine against aluminum-induced impairment on learning, memory and brain neurotransmitters in rats.

    Science.gov (United States)

    Wenting, Lu; Ping, Liu; Haitao, Jiao; Meng, Qiao; Xiaofei, Ren

    2014-10-01

    The aim of the study was to demonstrate the therapeutic effect of taurine against aluminum (Al)-induced neurological disorders in rats. Forty-two Wistar rats were randomly allotted into six groups: control (saline only), Al exposure (281.4 mg/kg/day for 1 month), Al + taurine (Al administration as previously plus taurine, doses were 200, 400 and 800 mg/kg/day, respectively, for the next 1 month) and prevention group (along with the Al administration as previously, 400 mg/kg/day taurine was treated for 1 month. During the next 1 month, rats were given taurine 400 mg/kg/day only). Starting from the sixth week, the body weight gain was significantly reduced in Al exposure group compared with saline (P < 0.05), and at the eighth week, the gain in prevention group was increased compared with Al (P < 0.05). Brain coefficient was gained in Al exposure compared with saline or prevention group (P < 0.05). Al exposure resulted in learning and memory impairment by increasing the escape latency and searching distance, meanwhile, decreasing the swimming time in the quadrant of platform and the numbers of crossing the platform (P < 0.05). Unsurprisingly, taurine treatment (400, 800 mg/kg/day and prevention) significantly protected against Al-induced brain dysfunction (P < 0.05). The Al exposure led to significant decreases in levels of γ-GABA and Tau, meanwhile, increased in level of Asp and Glu compared with saline (P < 0.05). And yet, taurine treatment partially reversed the deteriorated changes. The results suggested that taurine probably has neuroprotective effect against Al-induced learning, memory and brain neurotransmitters dysfunction.

  6. Effect of Aluminum and Silicon on Transformation Induced Plasticity of the TRIP Steel

    Institute of Scientific and Technical Information of China (English)

    Lin LI; B.C. De Cooman; P. Wollants; Yanlin HE; Xiaodong ZHOU

    2004-01-01

    With the sublattice model, equilibrium compositions of ferrite (α) and austenite (γ) phases, as well as the volume percent of austenite (γ) at 780℃ in different TRIP steels were calculated. Concentration profiles of carbon, Mn, Al and Si in the steels were also estimated under the lattice fixed frame of reference so as to understand the complex mechanical behavior of TRIP steels after different isothermal bainitic transformation treatments. The effect of Si and Mn on transformation induced plasticity (TRIP) was discussed according to thermodynamic and kinetic analyses. It is recognized that Al also induces phase transformation in the steels but its TRIP effect is not as strong as that of Si.

  7. Ion-induced nucleation of dibutyl phthalate vapors on spherical and nonspherical singly and multiply charged polyethylene glycol ions.

    Science.gov (United States)

    Nasibulin, Albert G; de la Mora, Juan Fernandez; Kauppinen, Esko I

    2008-02-14

    Dibutyl phthalate vapor nucleation induced by positive polyethylene glycol (PEG) ions with controlled sizes and charges was experimentally studied. The ions were produced by electrospray ionization, classified in a high-resolution differential mobility analyzer, and studied in a nano condensation nucleus counter of the mixing type. Ionic radii of PEG varied from 0.52 to 1.56 nm, including from singly to quadruply charged ions. Some of these ions are fully stretched chains, other are spherical, and others have intermediate forms, all of them having been previously characterized by mobility and mass spectrometry studies. Activation of PEG1080(+2) requires a supersaturation almost as high as that required for small singly charged ions and higher than for PEG1080(+). This anomaly is explained by the Coulombic stretching of the ion into a long chain, where the two charged centers appear to be relatively decoupled from each other. The critical supersaturation for singly charged spherical ions falls below Thomson's (capillary) theory and even below the already low values seen previously for tetraheptyl ammonium bromide clusters. Spherical PEG4120(+2) falls close to the Thomson curve. The trends observed for slightly nonspherical PEG4120(+3) and highly nonspherical (but not quite linear) PEG4120(+4) are intermediate between those of multiply charged spheres and small singly charged ions.

  8. Pattern of aluminum-induced secretion of organic acids differs between rye and wheat.

    Science.gov (United States)

    Li, X F; Ma, J F; Matsumoto, H

    2000-08-01

    Al-Induced secretion of organic acids from the roots has been considered as a mechanism of Al tolerance, but the processes leading to the secretion of organic acids are still unknown. In this study, the secretion pattern and alteration in the metabolism of organic acids under Al stress were examined in rye (Secale cereale L. cv King) and wheat (Triticum aestivum L. cv Atlas 66). Al induced rapid secretion of malate in the wheat, but a lag (6 and 10 h for malic and citric acids, respectively) between the exposure to Al and the secretion of organic acids was observed in the rye. The activities of isocitrate dehydrogenase, phosphoenolpyruvate carboxylase, and malate dehydrogenase were not affected by Al in either plant. The activity of citrate synthase was increased by the exposure to Al in the rye, but not in the wheat. The secretion of malate was not suppressed at low temperature in the wheat, but that of citrate was stopped in the rye. The Al-induced secretion of citrate from roots of the rye was inhibited by the inhibitors of a citrate carrier, which transports citrate from the mitochondria to the cytoplasm. All of these results suggest that alteration in the metabolism of organic acids is involved in the Al-induced secretion of organic acids in rye, but only activation of an anion channel seems to be responsible for the rapid secretion of malate in the wheat.

  9. Signal transduction events in aluminum-induced cell death in tomato suspension cells

    NARCIS (Netherlands)

    Iakimova, E.T.; Kapchina-Toteva, V.M.; Woltering, E.J.

    2007-01-01

    In this study, some of the signal transduction events involved in AlCl3-induced cell death in tomato (Lycopersicon esculentum Mill.) suspension cells were elucidated. Cells treated with 100 ¿M AlCl3 showed typical features of programmed cell death (PCD) such as nuclear and cytoplasmic condensation.

  10. Signal transduction events in aluminum-induced cell death in tomato suspension cells

    NARCIS (Netherlands)

    Iakimova, E.T.; Kapchina-Toteva, V.M.; Woltering, E.J.

    2007-01-01

    In this study, some of the signal transduction events involved in AlCl3-induced cell death in tomato (Lycopersicon esculentum Mill.) suspension cells were elucidated. Cells treated with 100 ¿M AlCl3 showed typical features of programmed cell death (PCD) such as nuclear and cytoplasmic condensation.

  11. Oxide-cladding aluminum nitride photonic crystal slab: Design and investigation of material dispersion and fabrication induced disorder

    Energy Technology Data Exchange (ETDEWEB)

    Melo, E. G., E-mail: emerdemelo@usp.br; Alvarado, M. A.; Carreño, M. N. P.; Alayo, M. I. [Electronic Systems Engineering Department, University of São Paulo, CEP 05508-010 São Paulo, SP (Brazil); Carvalho, D. O. [UNESP - São Paulo State University, CEP 13874-149 São João da Boa Vista, SP (Brazil); Ferlauto, A. S. [Department of Physics, Federal University of Minas Gerais, CEP 31270-901 Belo Horizonte, MG (Brazil)

    2016-01-14

    Photonic crystal slabs with a lower-index material surrounding the core layer are an attractive choice to circumvent the drawbacks in the fabrication of membranes suspended in air. In this work we propose a photonic crystal (PhC) slab structure composed of a triangular pattern of air holes in a multilayer thin film of aluminum nitride embedded in silicon dioxide layers designed for operating around 450 nm wavelengths. We show the design of an ideal structure and analyze the effects of material dispersion based on a first-order correction perturbation theory approach using dielectric functions obtained by experimental measurements of the thin film materials. Numerical methods were used to investigate the effects of fabrication induced disorder of typical nanofabrication processes on the bandgap size and spectral response of the proposed device. Deviation in holes radii and positions were introduced in the proposed PhC slab model with a Gaussian distribution profile. Impacts of slope in holes sidewalls that might result from the dry etching of AlN were also evaluated. The results show that for operation at the midgap frequency, slope in holes sidewalls is more critical than displacements in holes sizes and positions.

  12. Analysis of fast ion induced instabilities in tokamak plasmas

    CERN Document Server

    Horváth, László

    2015-01-01

    In magnetic confinement fusion devices like tokamaks, it is crucial to confine the high energy fusion-born helium nuclei ($\\alpha$-particles) to maintain the energy equilibrium of the plasma. However, energetic ions can excite various instabilities which can lead to their enhanced radial transport. Consequently, these instabilities may degrade the heating efficiency and they can also cause harmful power loads on the plasma-facing components of the device. Therefore, the understanding of these modes is a key issue regarding future burning plasma experiments. One of the main open questions concerning energetic particle (EP) driven instabilities is the non-linear evolution of the mode structure. In this thesis, I present my results on the investigation of $\\beta$-induced Alfv\\'{e}n eigenmodes (BAEs) and EP-driven geodesic acoustic modes (EGAMs) observed in the ramp-up phase of off-axis NBI heated plasmas in the ASDEX Upgrade tokamak. These modes were well visible on several line-of-sights (LOSs) of the soft X-ra...

  13. Light-Ion-Induced Multifragmentation: The ISiS Project

    CERN Document Server

    Viola, V E

    2006-01-01

    An extensive study of GeV light-ion-induced multifragmentation and its possible interpretation in terms of a nuclear liquid-gas phase transition has been performed with the Indiana Silicon Sphere (ISiS)4 pi detector array. Measurements were performed with 5-15 GeV/c p, pbar, and pion beams incident on $^{197}$Au and 2-5 GeV $^3$He incident on $^{nat}$Ag and $^{197}$Au targets. Both the reaction dynamics and the subsequent decay of the heavy residues have been explored. The data provide evidence for a dramatic change in the reaction observables near an excitation energy of E*/A = 4-5 MeV per residue nucleon. In this region, fragment multiplicities and energy spectra indicate emission from an expanded/dilute source on a very short time scale (20-50 fm/c). These properties, along with caloric curve and scaling-law behavior, yield a pattern that is consistent with a nuclear liquid-gas phase transition.

  14. Light-ion-induced multifragmentation: The ISiS project

    Science.gov (United States)

    Viola, V. E.; Kwiatkowski, K.; Beaulieu, L.; Bracken, D. S.; Breuer, H.; Brzychczyk, J.; de Souza, R. T.; Ginger, D. S.; Hsi, W.-C.; Korteling, R. G.; Lefort, T.; Lynch, W. G.; Morley, K. B.; Legrain, R.; Pienkowski, L.; Pollacco, E. C.; Renshaw, E.; Ruangma, A.; Tsang, M. B.; Volant, C.; Wang, G.; Yennello, S. J.; Yoder, N. R.

    2006-11-01

    An extensive study of GeV light-ion-induced multifragmentation and its possible interpretation in terms of a nuclear liquid-gas phase transition has been performed with the Indiana Silicon Sphere (ISiS) 4π detector array. Measurements were performed with 5-15 GeV/ c p, pbar, and π- beams incident on 197Au and 2-5 GeV 3He incident on natAg and 197Au targets. Both the reaction dynamics and the subsequent decay of the heavy residues have been explored. The data provide evidence for a dramatic change in the reaction observables near an excitation energy of E*/A=4-5 MeV/residue nucleon. In this region, fragment multiplicities and energy spectra indicate emission from an expanded/dilute source on a very short time scale (20-50 fm/ c). These properties, along with caloric curve and scaling-law behavior, yield a pattern that is consistent with a nuclear liquid-gas phase transition.

  15. Ion-induced erosion of organic self-assembled monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Cyganik, P. E-mail: cyganik@castor.if.uj.edu.pl; Postawa, Z.; Meserole, C.A.; Vandeweert, E.; Winograd, N

    1999-01-02

    Laser post-ionization mass spectrometry combined with Scanning Tunneling Microscopy (STM) has been used to investigate processes of ion-stimulated erosion of self-assembled monolayers (SAM) of phenethyl mercaptan C{sub 6}H{sub 5}CH{sub 2}CH{sub 2}S (PEM) deposited on gold. Results indicate that only PEM fragments are emitted from the surface. Most of the PEM fragments (predominantly C{sub 6}H{sub 5}CH{sub 2}CH{sub 3} with m/z=106) are emitted with thermal kinetic energies. STM images collected on 8 keV H{sup +}{sub 2}-irradiated surfaces with a system tuned to probe electronic states of sulfur atoms show no additional damage induced by irradiation. This indicates that sulfur atoms are not removed from the surface during hydrogen bombardment. It is proposed that the emission of SAM molecules is initiated by chemical reactions which gently break C-S bonds.

  16. Analysis of heavy-ion-induced DNA strand breaks in plasmid pUC18

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Plasmid DNA was irradiated or implanted by mixed particle field(CR) or lithium-ion-beam to detect strand breaks.The primary results showed that mixed particle field could induce single and double strand breaks with positive linear-dose-effects;most of sequence changes induced by CR were point mutant.Lithium-ion-beam could induce strand breaks also,but it was only at dose of 20Gy.

  17. Protective effect of selenium against aluminum chloride-induced Alzheimer's disease: behavioral and biochemical alterations in rats.

    Science.gov (United States)

    Lakshmi, B V S; Sudhakar, M; Prakash, K Surya

    2015-05-01

    In present study, selenium was selected for evaluating effect of selenium on aluminum chloride (AlCl3)-induced Alzheimer's disease in rats. Thirty Wistar rats were divided into five groups of six in each. Group I (control) received distilled water, group II-AlCl3 (100 mg/kg, p.o.), group III-selenium (1 mg/kg, p.o.), group IV-AlCl3 + vitamin E (100 mg/kg, p.o. + 100 mg/kg, p.o.), and group V-AlCl3 + selenium (100 mg/kg, p.o. + 1 mg/kg, p.o.) for 21 days. At end of experiment, various behavioral, biochemical, and histopathological assessments were carried out. The animals showed increase in time to reach platform in Morris water maze and decreased step-down latencies in passive avoidance test indicating learning and memory impairment in aluminum chloride-treated group, but administration of selenium decreased time to reach platform in Morris water maze, increased step-down latencies, and strengthened its memory action in drug-treated animals. There was decrease in muscle strength measured by rotarod test indicating motor incoordination and decrease in locomotor activity assessed by actophotometer test in AlCl3 control group, whereas in selenium-AlCl3 group, there was improvement in muscle strength and locomotion. Biochemical analysis of the brain revealed that chronic administration of AlCl3 significantly increased lipid peroxidation and decreased levels of acetyl cholinesterase, catalase, reduced glutathione and glutathione reductase, an index of oxidative stress process. Administration of selenium attenuated lipid peroxidation and ameliorated the biochemical changes. There were marked changes at subcellular level observed by histopathology studies in AlCl3 group, and better improvement in these changes was observed in selenium + AlCl3group. Therefore, this study strengthens the hypothesis that selenium helps to combat oxidative stress produced by accumulation of AlCl3 in the brain and helps in prophylaxis of Alzheimer's diseases.

  18. Technology basis and perspectives on focused electron beam induced deposition and focused ion beam induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rius, Gemma, E-mail: rius.gemma@nitech.ac.jp

    2014-12-15

    The main characteristics of focused electron beam induced deposition (FEBID) and focused ion beam induced deposition (FIBID) are presented. FEBID and FIBID are two nanopatterning techniques that allow the fabrication of submicron patterns with nanometer resolution on selected locations of any kind of substrate, even on highly structured supports. The process consists of mask less serial deposition and can be applied to a wide variety of materials, depending strictly on the precursor material source used. The basic mechanism of FEBID and FIBID is the adsorption of volatile precursor molecules onto the sample surface and decomposition of the molecules induced by the energetic electron and ion focused beams. The essential similarities of the two techniques are presented and especial emphasis is dedicated to highlighting their main differences, such as aspects related to resolution, deposition rate, deposits purity, substrate integrity, etc. In both cases, the factors interplay and complex mechanisms are still understood in a qualitative basis, so much work can still be done in terms of modeling and simulating the processes involved in FEBID and FIBID. Current work on FEBID and FIBID is presented through examples of achievements, interesting results and novel approaches.

  19. Synthesis of nanowires via helium and neon focused ion beam induced deposition with the gas field ion microscope.

    Science.gov (United States)

    Wu, H M; Stern, L A; Chen, J H; Huth, M; Schwalb, C H; Winhold, M; Porrati, F; Gonzalez, C M; Timilsina, R; Rack, P D

    2013-05-03

    The ion beam induced nanoscale synthesis of platinum nanowires using the trimethyl (methylcyclopentadienyl)platinum(IV) (MeCpPt(IV)Me3) precursor is investigated using helium and neon ion beams in the gas field ion microscope. The He(+) beam induced deposition resembles material deposited by electron beam induced deposition with very small platinum nanocrystallites suspended in a carbonaceous matrix. The He(+) deposited material composition was estimated to be 16% Pt in a matrix of amorphous carbon with a large room-temperature resistivity (∼3.5 × 10(4)-2.2 × 10(5) μΩ cm) and temperature-dependent transport behavior consistent with a granular material in the weak intergrain tunnel coupling regime. The Ne(+) deposited material has comparable composition (17%), however a much lower room-temperature resistivity (∼600-3.0 × 10(3) μΩ cm) and temperature-dependent electrical behavior representative of strong intergrain coupling. The Ne(+) deposited nanostructure has larger platinum nanoparticles and is rationalized via Monte Carlo ion-solid simulations which show that the neon energy density deposited during growth is much larger due to the smaller ion range and is dominated by nuclear stopping relative to helium which has a larger range and is dominated by electronic stopping.

  20. Magnetic Configuration Effects on Fast Ion Losses Induced by Fast Ion Driven Toroidal Alfven Eigenmodes in the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, K. [Nagoya University, Japan; Isobe, M. [National Institute for Fusion Science, Toki, Japan; Watanabe, F. [Kyoto University, Japan; Spong, Donald A [ORNL; Shimizu, A. [National Institute for Fusion Science, Toki, Japan; Osakabe, M. [National Institute for Fusion Science, Toki, Japan; Ohdachi, S. [National Institute for Fusion Science, Toki, Japan; Sakakibara, S. [National Institute for Fusion Science, Toki, Japan

    2012-01-01

    Beam-ion losses induced by fast-ion-driven toroidal Alfven eigenmodes (TAE) were measured with a scintillator-based lost fast-ion probe (SLIP) in the large helical device (LHD). The SLIP gave simultaneously the energy E and the pitch angle chi = arccos(v(parallel to)/v) distribution of the lost fast ions. The loss fluxes were investigated for three typical magnetic configurations of R{sub ax{_}vac} = 3.60 m, 3.75 m, and 3.90 m, where R{sub ax{_}vac} is the magnetic axis position of the vacuum field. Dominant losses induced by TAEs in these three configurations were observed in the E/chi regions of 50 similar to 190 keV/40 degrees, 40 similar to 170 keV/25 degrees, and 30 similar to 190 keV/30 degrees, respectively. Lost-ion fluxes induced by TAEs depend clearly on the amplitude of TAE magnetic fluctuations, R{sub ax{_}vac} and the toroidal field strength B{sub t}. The increment of the loss fluxes has the dependence of (b{sub TAE}/B{sub t}){sup s}. The power s increases from s = 1 to 3 with the increase of the magnetic axis position in finite beta plasmas.

  1. Characterization of local thermodynamic equilibrium in a laser-induced aluminum alloy plasma.

    Science.gov (United States)

    Zhang, Yong; Zhao, Zhenyang; Xu, Tao; Niu, GuangHui; Liu, Ying; Duan, Yixiang

    2016-04-01

    The electron temperature was evaluated using the line-to-continuum ratio method, and whether the plasma was close to the local thermodynamic equilibrium (LTE) state was investigated in detail. The results showed that approximately 5 μs after the plasma formed, the changes in the electron and excitation temperatures, which were determined using a Boltzmann plot, overlapped in the 15% error range, which indicated that the LTE state was reached. The recombination of electrons and ions and the free electron expansion process led to the deviation from the LTE state. The plasma's expansion rate slowed over time, and when the expansion time was close to the ionization equilibrium time, the LTE state was almost reached. The McWhirter criterion was adopted to calculate the threshold electron density for different species, and the results showed that experimental electron density was greater than the threshold electron density, which meant that the LTE state may have existed. However, for the nonmetal element N, the threshold electron density was greater than the value experimental value approximately 0.8 μs after the plasma formed, which meant that LTE state did not exist for N.

  2. Argon ion beam induced surface pattern formation on Si

    Energy Technology Data Exchange (ETDEWEB)

    Hofsäss, H.; Bobes, O.; Zhang, K. [2nd Institute of Physics, Faculty of Physics, University Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany)

    2016-01-21

    The development of self-organized surface patterns on Si due to noble gas ion irradiation has been studied extensively in the past. In particular, Ar ions are commonly used and the pattern formation was analyzed as function of ion incidence angle, ion fluence, and ion energies between 250 eV and 140 keV. Very few results exist for the energy regime between 1.5 keV and 10 keV and it appears that pattern formation is completely absent for these ion energies. In this work, we present experimental data on pattern formation for Ar ion irradiation between 1 keV and 10 keV and ion incidence angles between 50° and 75°. We confirm the absence of patterns at least for ion fluences up to 10{sup 18} ions/cm{sup 2}. Using the crater function formalism and Monte Carlo simulations, we calculate curvature coefficients of linear continuum models of pattern formation, taking into account contribution due to ion erosion and recoil redistribution. The calculations consider the recently introduced curvature dependence of the erosion crater function as well as the dynamic behavior of the thickness of the ion irradiated layer. Only when taking into account these additional contributions to the linear theory, our simulations clearly show that that pattern formation is strongly suppressed between about 1.5 keV and 10 keV, most pronounced at 3 keV. Furthermore, our simulations are now able to predict whether or not parallel oriented ripple patterns are formed, and in case of ripple formation the corresponding critical angles for the whole experimentally studied energies range between 250 eV and 140 keV.

  3. Removal of Aluminum from Water and Industrial Waste Water

    Directory of Open Access Journals (Sweden)

    Parisa Ghashghaiee pour

    2014-09-01

    Full Text Available This study attempts to introduce a procedure to remove Aluminum ions from drinking water and industrial effluents by using active carbon with different grading as absorbent. Absorption of Aluminum ions were discussed in different conditions of Aluminum concentration, contact time, impact of electrolytes and pH on Aluminum ions absorbency. Both Freundlich and Langmuir isotherms used to investigate the adsorption. Thermodynamics relations governing process, such as specification of ( , ( and the enthalpy of adsorption, were calculated, which showed that Aluminum absorption on active carbon is an endothermic and spontaneous process.

  4. Effects of Simulated Acid Rain on the Release of Aluminum Ion in the Soil%模拟酸雨对土壤释放铝离子的影响

    Institute of Scientific and Technical Information of China (English)

    万俊丽; 周小苹; 孙伟

    2016-01-01

    该研究用不同pH的溶液模拟酸雨淋洗土壤,不同时间同一pH的溶液模拟酸雨交换出铝离子,再用铝离子在醋酸-醋酸钠缓冲介质中与铬天青-S(CAS)及溴化十六烷基三甲基铵(CTMAB)反应生成蓝色三元铬合物在610nm处测其吸光度。结果表明:溶液的pH影响土壤淋洗液中的铝含量,随着酸雨pH的降低,淋出液中铝含量增加;同一pH溶液的淋浴时间越长,淋出液中铝离子浓度增大。酸雨使土壤的溶出铝量增加,从而危害植物的生长。%In solution of different pH of simulated acid rain solution leaching of soil, unequal time in the same pH of simulated acid rain solution aluminum ion was exchanged , aluminum ion in acetic acid sodium acetate buffer medi⁃um and chromium Azure-S(CAS)and cetyl trimethyl ammonium bromide(CTMAB)reaction to generate blue ternary chromium complexes and measuring the absorbance at 610 nm. The pH of the solution affected the aluminum con⁃tent in the soil leaching solution. With the decrease of the acid rain pH, the aluminum content in the leaching solu⁃tion was increased;the longer the bath time of the same pH solution , the greater the concentration of aluminum ion in the leaching solution. Acid rain increases the amount of dissolved aluminum in the soil, which is harmful to the growth of plants.

  5. Birefringence and polarization rotator induced by electromagnetically induced transparency in rare earth ion-doped crystals

    Science.gov (United States)

    Li, Zhixiang; Liu, Jianji; Yu, Ping; Zhang, Guoquan

    2016-05-01

    The birefringence induced by the electromagnetically induced transparency effect in a {Pr}^{3+}:{Y}_2 {SiO}_5 crystal was studied by using a balanced polarimeter technique. The results show that it is possible to control the polarization state of the output probe beam by adjusting the experimental conditions. Particularly, the coherently prepared {Pr}^{3+}:{Y}_2 {SiO}_5 crystal can serve as a polarization rotator for a linearly polarized input probe beam at the two-photon resonant condition. Such coherent control on the polarization of light should be useful for polarization-based classical and quantum information processing such as all-optical switching, polarization preserving light pulse memory and polarization qubits based on rare earth ion-doped solids.

  6. Charge-exchange Induced Modulation of the Heliosheath Ion Distribution Downstream of the Termination Shock

    Science.gov (United States)

    Fahr, H. J.; Fichtner, H.; Scherer, K.

    2015-12-01

    We consider the evolution of the solar wind ion distribution function alongthe plasma flow downstream from the termination shock induced by chargeexchange processes with cold interstellar H-atoms. We start from a kineticphase space transport equation valid in the bulk frame of the plasma flowthat takes into account convective changes, cooling processes, energydiffusion and ion injection, and describes solar wind and pick-up ionsas a co-moving, isotropic, joint ion population. From this kinetic transportequation one can ascend to an equation for the pressure moment of the iondistribution function, a so-called pressure transport equation, describingthe evolution of the ion pressure in the comoving rest frame. Assuming thatthe local ion distribution can be represented by an adequate kappa functionwith a kappa parameter that varies with the streamline coordinate, weobtain an ordinary differential equation for kappa as function of thestreamline coordinate s. With this result then we gain the heliosheath iondistribution function downstream of the termination shock. The latter thencan be used to predict the Voyager-2 measured moments of the distributionfunction like ion density and ion temperature, and it can also be used topredict spectral fluxes of ENA`s originating from these ions and registeredby IBEX-Hi and IBEX-Lo.We especially analyse the solar wind ion temperature decreasemeasured by Voyager-2 between the years 2008 to 2011 and try to explain itas a charge-exchange induced cooling of the ion distribution function duringthe associated ion convection period.

  7. Application of aluminum diffusion coatings to mitigate the KCl-induced high-temperature corrosion

    DEFF Research Database (Denmark)

    Kiamehr, Saeed; Lomholt, T. N.; Dahl, Kristian Vinter

    2017-01-01

    Pack cementation was used to produce Fe1−xAl and Fe2Al5 diffusion coatings on ferritic-martensitic steel P91 and a Ni2Al3 diffusion coating on pure nickel. The performance of diffusion coatings against high-temperature corrosion induced by potassium chloride (KCl) was evaluated by exposing......-ray diffractometry (XRD) before and after the exposures. It was found that all the diffusion coatings formed protective oxides under salt-free exposure in air. Under the salt deposit, Fe1−xAl showed local failure while on large parts of the sample a protective layer had formed. Fe2Al5 was attacked over the entire...

  8. Gamma-radiation-induced corrosion of aluminum alloy: low dose effect

    Science.gov (United States)

    Kanjana, K.; Ampornrat, P.; Channuie, J.

    2017-06-01

    Gamma-radiation-induced corrosion of aluminium alloy 6061 (AA6061) immersed in demineralized water was studied at radiation dose up to 206 kGy using a Co-60 gamma radiation source. The surface morphology and chemical composition of the oxide produced on the post-irradiated samples were investigated using SEM-EDS. The electrochemical corrosion potentials (Ecorr ) of the post-irradiated samples were measured. The corrosion behavior of AA6061 appeared to be dose dependent under the experimental conditions. A dramatic change in surface morphology was observed in the samples exposed to gamma radiation at 206 kGy. At this radiation dose the aluminium oxide scale developed can be clearly seen. The results from electrochemical corrosion tests have shown that the corrosion potentials (Ecorr ) can be undoubtedly decreased by gamma irradiation, giving corrosion rate of 7 × 10-4 mm/yr.

  9. Specificity of mutations induced by carbon ions in budding yeast Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Matuo, Youichirou [Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka 565-0871 (Japan); Nishijima, Shigehiro [Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka 565-0871 (Japan); Hase, Yoshihiro [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Sakamoto, Ayako [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Tanaka, Atsushi [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Shimizu, Kikuo [Radioisotope Research Center, Osaka University, Yamada-oka 2-4, Suita, Osaka 565-0871 (Japan)]. E-mail: shimizu@rirc.osaka-u.ac.jp

    2006-12-01

    To investigate the nature of mutations induced by accelerated ions in eukaryotic cells, the effects of carbon-ion irradiation were compared with those of {gamma}-ray irradiation in the budding yeast Saccharomyces cerevisiae. The mutational effect and specificity of carbon-ion beams were studied in the URA3 gene of the yeast. Our experiments showed that the carbon ions generated more than 10 times the number of mutations induced by {gamma}-rays, and that the types of base changes induced by carbon ions include transversions (68.7%), transitions (13.7%) and deletions/insertions (17.6%). The transversions were mainly G:C {sup {yields}} T:A, and all the transitions were G:C {sup {yields}} A:T. In comparison with the surrounding sequence context of mutational base sites, the C residues in the 5'-AC(A/T)-3' sequence were found to be easily changed. Large deletions and duplications were not observed, whereas ion-induced mutations in Arabidopsis thaliana were mainly short deletions and rearrangements. The remarkable feature of yeast mutations induced by carbon ions was that the mutation sites were localized near the linker regions of nucleosomes, whereas mutations induced by {gamma}-ray irradiation were located uniformly throughout the gene.

  10. Fractioning electrodialysis: a current induced ion exchange process

    NARCIS (Netherlands)

    Galama, A.H.; Daubaras, G.; Burheim, O.S.; Rijnaarts, H.; Post, J.W.

    2014-01-01

    In desalination often multi ionic compositions are encountered. A preferential removal of multivalent ions over monovalent ions can be of interest to prevent scaling in the desalination process. Recently, a novel fractionating electrodialysis stack is described by Zhang et al., 2012 (in Sep. purify.

  11. Fractioning electrodialysis : a current induced ion exchange process

    NARCIS (Netherlands)

    Galama, A. H.; Daubaras, G.; Burheim, O. S.; Rijnaarts, H. H. M.; Post, J. W.

    2014-01-01

    In desalination often multi ionic compositions are encountered. A preferential removal of multivalent ions over monovalent ions can be of interest to prevent scaling in the desalination process. Recently, a novel fractionating electrodialysis stack is described by Zhang et al., 2012 (in Sep. purify.

  12. Zinc-dependent protection of tobacco and rice cells from Aluminum-induced superoxide-mediated cytotoxicity

    Directory of Open Access Journals (Sweden)

    Cun eLin

    2015-12-01

    Full Text Available Al3+ toxicity in growing plants is considered as one of the major factors limiting the production of crops on acidic soils worldwide. In the last 15 years, it has been proposed that Al3+ toxicity are mediated with distortion of the cellular signaling mechanisms such as calcium signaling pathways, and production of cytotoxic reactive oxygen species (ROS causing oxidative damages. On the other hand, zinc is normally present in plants at high concentrations and its deficiency is one of the most widespread micronutrient deficiencies in plants. Earlier studies suggested that lack of zinc often results in ROS-mediated oxidative damage to plant cells. Previously, inhibitory action of Zn2+ against lanthanide-induced superoxide generation in tobacco cells have been reported, suggesting that Zn2+ interferes with the cation-induced ROS production via stimulation of NADPH oxidase. In the present study, the effect of Zn2+ on Al3+-induced superoxide generation in the cell suspension cultures of tobacco (Nicotiana tabacum L., cell-line, BY-2 and rice (Oryza sativa L., cv. Nipponbare, was examined. The Zn2+-dependent inhibition of the Al3+-induced oxidative burst was observed in both model cells selected from the monocots and dicots (rice and tobacco, suggesting that this phenomenon (Al3+/Zn2+ interaction can be preserved in higher plants. Subsequently induced cell death in tobacco cells was analyzed by lethal cell staining with Evans blue. Obtained results indicated that presence of Zn2+ at physiological concentrations can protect the cells by preventing the Al3+-induced superoxide generation and cell death. Furthermore, the regulation of the Ca2+ signaling, i.e. change in the cytosolic Ca2+ ion concentration, and the cross-talks among the elements which participate in the pathway were further explored.

  13. Heterogeneous oligonucleotide-hybridization assay based on hot electron-induced electrochemiluminescence of a rhodamine label at oxide-coated aluminum and silicon electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Spehar-Deleze, Anna-Maria [Laboratory of Sensors, Actuators and Microsystems, Institute of Microtechnology, University of Neuchatel, Rue Jaquet-Droz 1, CH-2007 Neuchatel (Switzerland) and Laboratory of Inorganic and Analytical Chemistry, Helsinki University of Technology, Kemistintie 1, FIN-02015 HUT (Finland)]. E-mail: anna-maria.spehar@unine.ch; Suomi, Johanna [Laboratory of Inorganic and Analytical Chemistry, Helsinki University of Technology, Kemistintie 1, FIN-02015 HUT (Finland); Jiang Qinghong [Laboratory of Inorganic and Analytical Chemistry, Helsinki University of Technology, Kemistintie 1, FIN-02015 HUT (Finland); Rooij, Nico de [Laboratory of Sensors, Actuators and Microsystems, Institute of Microtechnology, University of Neuchatel, Rue Jaquet-Droz 1, CH-2007 Neuchatel (Switzerland); Koudelka-Hep, Milena [Laboratory of Sensors, Actuators and Microsystems, Institute of Microtechnology, University of Neuchatel, Rue Jaquet-Droz 1, CH-2007 Neuchatel (Switzerland); Kulmala, Sakari [Laboratory of Inorganic and Analytical Chemistry, Helsinki University of Technology, Kemistintie 1, FIN-02015 HUT (Finland)

    2006-07-28

    This paper describes a heterogeneous oligonucleotide-hybridization assay based on hot electron-induced electrochemiluminescence (HECL) of a rhodamine label. Thin oxide-film coated aluminum and silicon electrodes were modified with an aminosilane layer and derivatized with short, 15-mer oligonucleotides via diisothiocyanate coupling. Target oligonucleotides were conjugated with tetramethylrhodamine (TAMRA) dye at their amino modified 5' end and hybridization was detected using HECL of TAMRA. Preliminary results indicate sensitivity down to picomolar level and low nonspecific adsorption. The sensitivity was better on oxide-coated silicon compared to oxide-coated aluminum electrodes and two-base pair mismatched hybrids were successfully discriminated. The experimental results presented here might be useful for the design of disposable electrochemiluminescent DNA biosensors.

  14. ION-BEAM INDUCED GENERATION OF CU ADATOMS ON CU(100)

    NARCIS (Netherlands)

    BREEMAN, M; BOERMA, DO

    1992-01-01

    Low-energy ion scattering was used to study on-beam induced adatom generation during irradiation of a Cu(100) surface with 6 keV Ne ions at a sample temperature of 60 K. It was found that the number of adatoms produced per incoming ion decreases from an average of 3.5 to a saturation level of 1.8 af

  15. Laser-induced back-ablation of aluminum thin films using picosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    BULLOCK, A B

    1999-05-26

    Experiments were performed to understand laser-induced back-ablation of Al film targets with picosecond laser pulses. Al films deposited on the back surface of BK-7 substrates are ablated by picosecond laser pulses propagating into the Al film through the substrate. The ablated Al plume is transversely probed by a time-delayed, two-color sub-picoseond (500 fs) pulse, and this probe is then used to produce self-referencing interferograms and shadowgraphs of the Al plume in flight. Optical emission from the Al target due to LIBA is directed into a time-integrated grating spectrometer, and a time-integrating CCD camera records images of the Al plume emission. Ablated Al plumes are also redeposited on to receiving substrates. A post-experimental study of the Al target and recollected deposit characteristics was also done using optical microscopy, interferometry, and profilometry. In this high laser intensity regime, laser-induced substrate ionization and damage strongly limits transmitted laser fluence through the substrate above a threshold fluence. The threshold fluence for this ionization-based transmission limit in the substrate is dependent on the duration of the incident pulse. The substrate ionization can be used as a dynamic control of both transmitted spatial pulse profile and ablated Al plume shape. The efficiency of laser energy transfer between the laser pulse incident on the Al film and the ablated Al plume is estimated to be of order 5% and is a weak function of laser pulsewidth. The Al plume is highly directed. Low plume divergence ({theta}{sub divergence} < 5{sup o}) shows the ablated plume temperature to be very low at long time delays ( T << 0.5 eV at delays of 255 ns). Spectroscopic observations and calculations indicate that, in early time (t < 100 ps), the Al film region near the substrate/metal interface is at temperatures of order 0.5 eV. Interferograms of Al plumes produced with 0.1 {micro}m films show these plumes to be of high neutral atom

  16. Aluminum-induced cell wall peroxidase activity and lignin synthesis are differentially regulated by jasmonate and nitric oxide.

    Science.gov (United States)

    Xue, Yao Juan; Tao, Ling; Yang, Zhi Min

    2008-10-22

    Cassia tora is an annual legume and cultivated as a traditional medicinal herb for multiple therapies including regulation of blood pressure and blood lipid. Because of naturally occurring acidic soils in southeastern China, this plant species may possess strategies for tolerance to low pH and aluminum toxicity. In the search for the regulatory basis of biochemical response to Al, cell wall-bound peroxidases, including lignin-generated peroxidases and NADH oxidases, were investigated in the root tips of C. tora. Activities of both types of peroxidases significantly increased with Al concentrations. Analysis with native PAGE also demonstrated the strong induction of cell wall peroxidases by Al. The Al-induced increasing activities of peroxidases were closely correlated with lignin accumulation and H 2O 2 production. The biochemical effect of exogenous nitric oxide (NO) and methyl jasmonic acid (MJ) was examined to investigate signal properties and lignin synthesis under Al stress. Application of MJ at 10 microM promoted root sensitivity to Al by activating apoplastic peroxidase activity and accumulating H 2O 2 and lignin, whereas the opposite action was found for NO. The sensitivity of apoplastic peroxidases under Al stress was associated with the cross-talk of MJ and NO signals. The analysis reveals that the activity of lipoxygenase (an enzyme for MJ biosynthesis), with its transcripts increased in Al-exposed roots, was depressed by NO exposure. The effect of MJ on intracellular NO production was also investigated. It is shown that NO staining with 4,5-diaminofluorescein diacetate fluorescence was intensified by Al but was suppressed by MJ. These results suggest that NO and MJ may interplay in signaling the cell wall peroxidase activity and lignin synthesis in the roots exposed to Al.

  17. Effects of Aluminum Addition on Tensile and Cup Forming Properties of Three Twinning Induced Plasticity Steels

    Science.gov (United States)

    Hong, Seokmin; Shin, Sang Yong; Kim, Hyoung Seop; Lee, Sunghak; Kim, Sung-Kyu; Chin, Kwang-Geun; Kim, Nack J.

    2012-06-01

    In the present study, a high Mn twinning induced plasticity (TWIP) steel and two Al-added TWIP steels were fabricated, and their microstructures, tensile properties, and cup formability were analyzed to investigate the effects of Al addition on deformation mechanisms in tensile and cup forming tests. In the high Mn steel, the twin formation was activated to increase the strain hardening rate and ultimate tensile strength, which needed the high punch load during the cup forming test. In the Al-added TWIP steels, the twin formation was reduced, while the slip activation increased, thereby leading to the decrease in strain hardening rate and ultimate tensile strength. As twins and slips were homogeneously formed during the tensile or cup forming test, the punch load required for the cup forming and residual stresses were relatively low, and the tensile ductility was sufficiently high even after the cup forming test. This indicated that making use of twins and slips simultaneously in TWIP steels by the Al addition was an effective way to improve overall properties including cup formability.

  18. Amelioration of iron toxicity: A mechanism for aluminum-induced growth stimulation in tea plants.

    Science.gov (United States)

    Hajiboland, Roghieh; Barceló, Juan; Poschenrieder, Charlotte; Tolrà, Roser

    2013-11-01

    Tea plants (Camellia sinensis) are well adapted to acid soils with high Al availability. These plants not only accumulate high leaf Al concentrations, but also respond to Al with growth stimulation. Decreased oxidative stress has been associated with this effect. Why tea plants not exposed to Al suffer from oxidative stress has not been clarified. In this study, hydroponically grown tea plants treated with 0 to 300 μM Al were analyzed for growth, Al and Fe accumulation, and Al distribution by means of morin and hematoxylin staining. Roots of control plants stained black with hematoxylin. This indicates the formation of a Fe-hematoxylin complex. Young leaves of controls accumulated more than 1000 mg Fe kg(-1) dry weight. This concentration is above the Fe-toxicity threshold in most species. Supply of Al stimulated growth and reduced Fe uptake and transport. These results indicate that Al-induced growth stimulation might be due to alleviation of a latent Fe toxicity occurring in tea plants without Al supply.

  19. Study of transient current induced by heavy-ion microbeams in Si and GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Hirao, Toshio; Nashiyama, Isamu; Kamiya, Tomihiro; Suda, Tamotu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Heavy-ion microbeams were applied to the study of mechanism of single event upset (SEU). Transient current induced in p{sup +}n junction diodes by strike of heavy ion microbeam were measured by using a high-speed digitizing sampling system. (author)

  20. Focused helium and neon ion beam induced etching for advanced extreme ultraviolet lithography mask repair

    NARCIS (Netherlands)

    Gonzalez, Carlos M.; Timilsina, Rajendra; Li, Guoliang; Duscher, Gerd; Rack, Philip D.; Slingenbergh, Winand; van Dorp, Willem F.; De Hosson, Jeff T. M.; Klein, Kate L.; Wu, Huimeng M.; Stern, Lewis A.

    2014-01-01

    The gas field ion microscope was used to investigate helium and neon ion beam induced etching of nickel as a candidate technique for extreme ultraviolet (EUV) lithography mask editing. No discernable nickel etching was observed for room temperature helium exposures at 16 and 30 keV in the dose range

  1. Formulation and method for preparing gels comprising hydrous aluminum oxide

    Science.gov (United States)

    Collins, Jack L.

    2014-06-17

    Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.

  2. Structural modification of tantalum crystal induced by nitrogen ion implantation

    Indian Academy of Sciences (India)

    A H RAMEZANI; M R HANTEHZADEH; M GHORANNEVISS; E DARABI

    2016-06-01

    This paper investigates the effect of nitrogen ion implantation on tantalum surface structure. In this experiment, nitrogen ions which had an energy of 30 keV and doses of $1 \\times 10^{17}$ to $10 \\times 10^{17}$ ions cm$^{−2}$ were used. X-ray diffraction analysis (XRD) was applied for both the metallic Ta substrate and the study of new structures that have been created through the nitrogen ion implantation. Atomic force microscopy (AFM) was also used tocheck the roughness variations prior to and also after the implantation phase. The experimental results show the formation of hexagonal tantalum nitride (TaN$_{0.43}$) in addition to the fact that by increasing the ion dose, the nitrogen atoms occupy more interstitial spaces in the target crystal. The nitride phase also seen for $3\\times 10^{17}$ and $5\\times 10^{17}$ ions cm$^{−2}$, while it disappeared for higher dose of $7\\times 10^{17}$ and $1\\times 10^{18}$ ions cm$^{−2}$. The FWHM of the dominant peak of tantalum nitride suggest the growth of the crystallite’s size, which is in agreement with the AFM results ofthe grains.

  3. Decomposition of cyclohexane ion induced by intense femtosecond laser fields by ion-trap time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Takao; Watanabe, Yusuke; Kanya, Reika [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Yamanouchi, Kaoru, E-mail: kaoru@chem.s.u-tokyo.ac.jp [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); NANOQUINE, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2016-01-14

    Decomposition of cyclohexane cations induced by intense femtosecond laser fields at the wavelength of 800 nm is investigated by ion-trap time-of-flight mass spectrometry in which cyclohexane cations C{sub 6}H{sub 12}{sup +} stored in an ion trap are irradiated with intense femtosecond laser pulses and the generated fragment ions are recorded by time-of-flight mass spectrometry. The various fragment ion species, C{sub 5}H{sub n}{sup +} (n = 7, 9), C{sub 4}H{sub n}{sup +} (n = 5–8), C{sub 3}H{sub n}{sup +} (n = 3–7), C{sub 2}H{sub n}{sup +} (n = 2–6), and CH{sub 3}{sup +}, identified in the mass spectra show that decomposition of C{sub 6}H{sub 12}{sup +} proceeds efficiently by the photo-irradiation. From the laser intensity dependences of the yields of the fragment ion species, the numbers of photons required for producing the respective fragment ions are estimated.

  4. EPR of Nd{sup 3+} and Er{sup 3+} ions in aluminum borates YAl{sub 3}(BO{sub 3}){sub 4} and EuAl{sub 3}(BO{sub 3}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Prokhorov, A.D. [A. A. Galkin Donetsk Physico-Technical Institute, NANU, 83114 Donetsk, R. Luxembourg Street 72 (Ukraine); Prokhorov, A.A., E-mail: prohorov@pr.fti.ac.donetsk.ua [A. A. Galkin Donetsk Physico-Technical Institute, NANU, 83114 Donetsk, R. Luxembourg Street 72 (Ukraine); Chernysh, L.F. [A. A. Galkin Donetsk Physico-Technical Institute, NANU, 83114 Donetsk, R. Luxembourg Street 72 (Ukraine); Aleshkevich, P. [Institute of Physics, PAS, 02-668 Warsaw, Al. Lotnikow 32/46 (Poland); Dyakonov, V. [A. A. Galkin Donetsk Physico-Technical Institute, NANU, 83114 Donetsk, R. Luxembourg Street 72 (Ukraine); Institute of Physics, PAS, 02-668 Warsaw, Al. Lotnikow 32/46 (Poland); Szymczak, H. [Institute of Physics, PAS, 02-668 Warsaw, Al. Lotnikow 32/46 (Poland)

    2013-01-15

    EPR spectra of impurity Nd{sup 3+} and Er{sup 3+} ions in aluminum borates YAl{sub 3}(BO{sub 3}){sub 4} and EuAl{sub 3}(BO{sub 3}){sub 4} have been studied. Dependences of g-factors and linewidth as a function of temperature are established, and the hyperfine interaction constants are determined. Temperature dependences of linewidth of Nd{sup 3+} and Er{sup 3+} ions in both crystals are identical. The absorption line broadening with increasing temperature is caused by strong spin-phonon interaction and is described by the Orbach-Aminov process. Unlike Nd{sup 3+} ion, an anisotropy of temperature dependence of Er{sup 3+} ion linewidth is observed. The relaxation velocity of Er{sup 3+} ions is lower then that of Nd{sup 3+} ions. The anisotropy of spin-lattice relaxation observed for Er{sup 3} ion is due to a large g-factor anisotropy which is larger in the EuAl{sub 3}(BO{sub 3}){sub 4} crystal than in YAl{sub 3}(BO{sub 3}){sub 4} one. A decrease of g-factor of Er{sup 3+} ion in both crystals with increasing temperature is shown to result from spin-phonon interaction. - Highlights: Black-Right-Pointing-Pointer The absorption lines broadening is described by the Orbach-Aminov process. Black-Right-Pointing-Pointer A decrease of g-factor of Er{sup 3+} ion in crystals is caused by spin-phonon interaction. Black-Right-Pointing-Pointer The hyperfine interaction constants are determined. Black-Right-Pointing-Pointer The relaxation velocity of Er{sup 3+} ions is lower than that of Nd{sup 3+} ions.

  5. Charge collection efficiency degradation induced by MeV ions in semiconductor devices: Model and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vittone, E., E-mail: ettore.vittone@unito.it [Department of Physics, NIS Research Centre and CNISM, University of Torino, via P. Giuria 1, 10125 Torino (Italy); Pastuovic, Z. [Centre for Accelerator Science (ANSTO), Locked bag 2001, Kirrawee DC, NSW 2234 (Australia); Breese, M.B.H. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Garcia Lopez, J. [Centro Nacional de Aceleradores (CNA), Sevilla University, J. Andalucia, CSIC, Av. Thomas A. Edison 7, 41092 Sevilla (Spain); Jaksic, M. [Department for Experimental Physics, Ruder Boškovic Institute (RBI), P.O. Box 180, 10002 Zagreb (Croatia); Raisanen, J. [Department of Physics, University of Helsinki, Helsinki 00014 (Finland); Siegele, R. [Centre for Accelerator Science (ANSTO), Locked bag 2001, Kirrawee DC, NSW 2234 (Australia); Simon, A. [International Atomic Energy Agency (IAEA), Vienna International Centre, P.O. Box 100, 1400 Vienna (Austria); Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Vizkelethy, G. [Sandia National Laboratories (SNL), PO Box 5800, Albuquerque, NM (United States)

    2016-04-01

    Highlights: • We study the electronic degradation of semiconductors induced by ion irradiation. • The experimental protocol is based on MeV ion microbeam irradiation. • The radiation induced damage is measured by IBIC. • The general model fits the experimental data in the low level damage regime. • Key parameters relevant to the intrinsic radiation hardness are extracted. - Abstract: This paper investigates both theoretically and experimentally the charge collection efficiency (CCE) degradation in silicon diodes induced by energetic ions. Ion Beam Induced Charge (IBIC) measurements carried out on n- and p-type silicon diodes which were previously irradiated with MeV He ions show evidence that the CCE degradation does not only depend on the mass, energy and fluence of the damaging ion, but also depends on the ion probe species and on the polarization state of the device. A general one-dimensional model is derived, which accounts for the ion-induced defect distribution, the ionization profile of the probing ion and the charge induction mechanism. Using the ionizing and non-ionizing energy loss profiles resulting from simulations based on the binary collision approximation and on the electrostatic/transport parameters of the diode under study as input, the model is able to accurately reproduce the experimental CCE degradation curves without introducing any phenomenological additional term or formula. Although limited to low level of damage, the model is quite general, including the displacement damage approach as a special case and can be applied to any semiconductor device. It provides a method to measure the capture coefficients of the radiation induced recombination centres. They can be considered indexes, which can contribute to assessing the relative radiation hardness of semiconductor materials.

  6. Effect of Nitrite Ions on Steel Corrosion Induced by Chloride or Sulfate Ions

    Directory of Open Access Journals (Sweden)

    Zhonglu Cao

    2013-01-01

    Full Text Available The influence of nitrite concentration on the corrosion of steel immersed in three simulated pH environments containing chloride ions or sulfate ions has been investigated by comparing and analyzing the change of half-cell potential, the change of threshold level of Cl- or SO42-, the change of threshold level of NO2-/Cl- or NO2-/SO42- mole ratio, and the changes of anodic/cathodic polarization curves and Stern-Geary constant B. The corrosivity of chloride ions against sulfate ions also has been discussed in pH 12.6, pH 10.3, and pH 8.1 environments containing 0, 0.053, and 0.2 mol/L NO2, respectively.

  7. Effect of ion velocity on SHI-induced mixing in Ti/Bi system

    Science.gov (United States)

    Bansal, Nisha; Kumar, Sarvesh; Khan, Saif Ahmad; Chauhan, R. S.

    2016-03-01

    Energetic ion beams are proving to be versatile tools for modification and depth profiling of materials. The energy and ion species are the deciding factor in the ion-beam-induced materials modification. Among the various parameters such as electronic energy loss, fluence and heat of mixing, velocity of the ions used for irradiation plays an important role in mixing at the interface. The present study is carried out to find the effect of the velocity of swift heavy ions on interface mixing of a Ti/Bi bilayer system. Ti/Bi/C was deposited on Si substrate at room temperature by an electron gun in a high-vacuum deposition system. Carbon layer is deposited on top to avoid oxidation of the samples. Eighty mega electron volts Au ions and 100 MeV Ag ions with same value of Se for Ti are used for the irradiation of samples at the fluences 1 × 1013-1 × 1014 ions/cm2. Different techniques like Rutherford backscattering spectroscopy, atomic force microscopy and grazing incidence X-ray diffraction were used to characterize the pristine and irradiated samples. The mixing effect is explained in the framework of the thermal spike model. It has been found that the mixing rate is higher for low-velocity Au ions in comparison to high-velocity Ag ions. The result could be explained as due to less energy deposition in thermal spike by high-velocity ions.

  8. A New Method of Measuring Electron Emission Induced by Low Energy Ions from Solids

    Institute of Scientific and Technical Information of China (English)

    ZHANG Heng-Da; A. Breskin; R. Chechik; S. Shckemelinin; E. Cheifetz

    2005-01-01

    @@ A new mathematical method of measuring electron emission induced by low energy ions from solids is described and used to calculate secondary electron emission according to the recorded pulse-height spectra of ions and ultraviolet (UV) photons. Using the UV single secondary electron spectra, we predict the shape of many secondary electron distributions under consideration of detection efficiency of MCP detector. These calculated distributions allow us to characterize the secondary electrons yield, and to give a secondary electron distribution for measured data. It seems rather feasible to determine secondary electron yield emitted by low energy ions at very low ion fluxes.

  9. Collision induced fragmentation of fast molecular ions in solids and gases. [Review, wake effects, excited states

    Energy Technology Data Exchange (ETDEWEB)

    Gemmell, D S

    1979-01-01

    A brief review is given of recent high resolution measurements on fragments arising from the collision-induced dissociation of fast (MeV) molecular ions. For solid targets, strong wake effects are observed. For gaseous targets, excited electronic states of the projectile ions play an important role. Measurements of this type provide useful information on the charge states of fast ions traversing matter. The experimental techniques show promise as a unique method for determining the geometrical structures of the molecular-ion projectiles. 41 references.

  10. Characterisation of Swift Heavy Ion-induced Mixing using Secondary Ion Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    B. R. Chakraborty

    2009-07-01

    Full Text Available Swift heavy ions of Au at 120 MeV are irradiated at the interface of Si/Me/Si (Me=V,Fe,Co and the behaviour of mixing examined wrt to different ion doses. The fluences were varied from 1x1013 ions/cm2 to 1x1014 ions/cm2 on the multilayers of Si/Me/Se (Me=V,Fe,Co and the interface of Si/Me(Me=V,Fe,Co were characterised using Rutherford backscattering spectroscopy(RBS and secondary ion mass spectrometry (SIMS. The atomic mixing width was found to be increasing monotonically with ion fluence in all the three cases,. The mixing rate and efficiency calculations were made and the diffusivity values thus obtained suggested a transient melt phase at the interface according to thermal spike model. In case of Me=Co, it was further probed with XRD and Raman spectroscopy to confirm the formation of cobalt silicides even at room temperature.Defence Science Journal, 2009, 59(4, pp.356-362, DOI:http://dx.doi.org/10.14429/dsj.59.1534

  11. Evolution of ion-induced nanoparticle arrays on GaAs surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kang, M.; Al-Heji, A. A.; Shende, O.; Huang, S.; Jeon, S.; Goldman, R. S., E-mail: rsgold@umich.edu [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Beskin, I. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)

    2014-05-05

    We have examined the evolution of irradiation-induced Ga nanoparticle (NP) arrays on GaAs surfaces. Focused-ion-beam irradiation of pre-patterned GaAs surfaces induces monotonic increases in the NP volume and aspect ratio up to a saturation ion dose, independent of NP location within the array. Beyond the saturation ion dose, the NP volume continues to increase monotonically while the NP aspect ratio decreases monotonically. In addition, the NP volumes (aspect ratios) are highest (lowest) for the corner NPs. We discuss the relative influences of bulk and surface diffusion on the evolution of Ga NP arrays.

  12. Evolution of ion-induced nanoparticle arrays on GaAs surfaces

    Science.gov (United States)

    Kang, M.; Beskin, I.; Al-Heji, A. A.; Shende, O.; Huang, S.; Jeon, S.; Goldman, R. S.

    2014-05-01

    We have examined the evolution of irradiation-induced Ga nanoparticle (NP) arrays on GaAs surfaces. Focused-ion-beam irradiation of pre-patterned GaAs surfaces induces monotonic increases in the NP volume and aspect ratio up to a saturation ion dose, independent of NP location within the array. Beyond the saturation ion dose, the NP volume continues to increase monotonically while the NP aspect ratio decreases monotonically. In addition, the NP volumes (aspect ratios) are highest (lowest) for the corner NPs. We discuss the relative influences of bulk and surface diffusion on the evolution of Ga NP arrays.

  13. Ion irradiation induced disappearance of dislocations in a nickel-based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.C.; Li, D.H.; Lui, R.D.; Huang, H.F.; Li, J.J.; Lei, G.H.; Huang, Q.; Bao, L.M.; Yan, L., E-mail: yanlong@sinap.ac.cn; Zhou, X.T., E-mail: zhouxingtai@sinap.ac.cn; Zhu, Z.Y.

    2016-06-15

    Under Xe ion irradiation, the microstructural evolution of a nickel based alloy, Hastelloy N (US N10003), was studied. The intrinsic dislocations are decorated with irradiation induced interstitial loops and/or clusters. Moreover, the intrinsic dislocations density reduces as the irradiation damage increases. The disappearance of the intrinsic dislocations is ascribed to the dislocations climb to the free surface by the absorption of interstitials under the ion irradiation. Moreover, the in situ annealing experiment reveals that the small interstitial loops and/or clusters induced by the ion irradiation are stable below 600 °C.

  14. The influence of projectile ion induced chemistry on surface pattern formation

    Science.gov (United States)

    Karmakar, Prasanta; Satpati, Biswarup

    2016-07-01

    We report the critical role of projectile induced chemical inhomogeneity on surface nanostructure formation. Experimental inconsistency is common for low energy ion beam induced nanostructure formation in the presence of uncontrolled and complex contamination. To explore the precise role of contamination on such structure formation during low energy ion bombardment, a simple and clean experimental study is performed by selecting mono-element semiconductors as the target and chemically inert or reactive ion beams as the projectile as well as the source of controlled contamination. It is shown by Atomic Force Microscopy, Cross-sectional Transmission Electron Microscopy, and Electron Energy Loss Spectroscopy measurements that bombardment of nitrogen-like reactive ions on Silicon and Germanium surfaces forms a chemical compound at impact zones. Continuous bombardment of the same ions generates surface instability due to unequal sputtering and non-uniform re-arrangement of the elemental atom and compound. This instability leads to ripple formation during ion bombardment. For Argon-like chemically inert ion bombardment, the chemical inhomogeneity induced boost is absent; as a result, no ripples are observed in the same ion energy and fluence.

  15. A large area position-sensitive ionization chamber for heavy-ion-induced reaction studies

    Energy Technology Data Exchange (ETDEWEB)

    Pant, L.M. E-mail: lalit.pant@exp2.physik.uni-giessen.de; Biswas, D.C.; Dinesh, B.V.; Thomas, R.G.; Saxena, A.; Sawant, Y.S.; Choudhury, R.K

    2002-12-11

    A large area position-sensitive ionization chamber with a wide dynamic range has been developed to measure the mass, charge and energy of the heavy ions and the fission fragments produced in heavy-ion-induced reactions. The split anode geometry of the detector makes it suitable for both particle identification and energy measurements for heavy ions and fission fragments. The detector has been tested with {alpha} particles from {sup 241}Am-{sup 239}Pu source, fission fragments from {sup 252}Cf and the heavy-ion beams from the 14UD Mumbai Pelletron accelerator facility. Using this detector, measurements on mass and total kinetic energy distributions in heavy-ion-induced fusion-fission reactions have been carried out for a wide range of excitation energies. Results on deep inelastic collisions and mass-energy correlations on different systems using this detector setup are discussed.

  16. A large area position-sensitive ionization chamber for heavy-ion-induced reaction studies

    CERN Document Server

    Pant, L M; Dinesh, B V; Thomas, R G; Saxena, A; Sawant, Y S; Choudhury, R K

    2002-01-01

    A large area position-sensitive ionization chamber with a wide dynamic range has been developed to measure the mass, charge and energy of the heavy ions and the fission fragments produced in heavy-ion-induced reactions. The split anode geometry of the detector makes it suitable for both particle identification and energy measurements for heavy ions and fission fragments. The detector has been tested with alpha particles from sup 2 sup 4 sup 1 Am- sup 2 sup 3 sup 9 Pu source, fission fragments from sup 2 sup 5 sup 2 Cf and the heavy-ion beams from the 14UD Mumbai Pelletron accelerator facility. Using this detector, measurements on mass and total kinetic energy distributions in heavy-ion-induced fusion-fission reactions have been carried out for a wide range of excitation energies. Results on deep inelastic collisions and mass-energy correlations on different systems using this detector setup are discussed.

  17. Aluminum alloy

    Science.gov (United States)

    Blackburn, Linda B. (Inventor); Starke, Edgar A., Jr. (Inventor)

    1989-01-01

    This invention relates to aluminum alloys, particularly to aluminum-copper-lithium alloys containing at least about 0.1 percent by weight of indium as an essential component, which are suitable for applications in aircraft and aerospace vehicles. At least about 0.1 percent by weight of indium is added as an essential component to an alloy which precipitates a T1 phase (Al2CuLi). This addition enhances the nucleation of the precipitate T1 phase, producing a microstructure which provides excellent strength as indicated by Rockwell hardness values and confirmed by standard tensile tests.

  18. Ion-beam-induced nanodots formation from Au/Si thin films on quartz surface

    Energy Technology Data Exchange (ETDEWEB)

    Datta, D.P.; Siva, V.; Singh, A. [School of Physical Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Jatni - 752050, Odisha (India); Joshi, S.R. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005, Odisha (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Sahoo, P.K., E-mail: pratap.sahoo@niser.ac.in [School of Physical Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Jatni - 752050, Odisha (India)

    2016-07-15

    We report the synthesis of Si nanodots on quartz surface using ion irradiation. When a bi-layer of ultrathin Au and Si on quartz surface is irradiated by 500 keV Xe-ion beam, the bi-layer spontaneously transforms into nanodots at a fluence of 5 × 10{sup 14} ions cm{sup −2}. The spatial density and diameter of the nanodots are reduced with increase in applied ion fluence. The nanostructures exhibit photoluminescence in the visible range at room temperature where the intensity and wavelength depends upon ion fluence. The observed evolution seems to be correlated to ion beam mixing induced silicide formation at Au–Si interface.

  19. Method of ions acceleration for laser-induced implantation of semiconductor materials

    Science.gov (United States)

    Czarnecka, A.; Badziak, J.; Parys, P.; Rosinski, M.; Wołowski, J.

    The application of electrostatic fields for the formation of laser-generated ions makes it possible to control the ion stream parameters in broad energy and current density ranges. It also permits to remove the useless ions from the ion stream designed for laser-induced implantation and deposition of layers of semiconductor materials. For acceleration of ions a special electrostatic system has been completed and tested at the Institute of Plasma Physics and Laser Microfusion (IPPLM). A repetitive Nd: glass laser with energy of ˜0.5 J in a 3.5 ns pulse, wavelength of 1.06 μm, repetition rate of up to 10 Hz and intensity on the target of up to 1011 W cm-2, has been recently employed to produce ions emitted from irradiated solid targets. The movable target holder was located inside the cylindrical box connected with a high-voltage source (up to 50 kV). The ions passing through the diaphragm in this box were accelerated in the system of electrodes in the electrostatic field formed in the gap between the box and a grid mounted at the end of the grounded cylindrical electrode. The parameters of the ion streams were measured with the use of several ion collectors and an electrostatic ion energy analyzer (IEA). The Ge ion stream attained energy of up to 30 keV and ion fluency 1011 ions/cm2 for one laser shot. The maximum ion charge state measured with the use of IEA was 3+.

  20. Multiscale physics of ion-induced radiation damage.

    Science.gov (United States)

    Surdutovich, Eugene; Solov'yov, A V

    2014-01-01

    This is a review of a multiscale approach to the physics of ion-beam cancer therapy, an approach suggested in order to understand the interplay of a large number of phenomena involved in the radiation damage scenario occurring on a range of temporal, spatial, and energy scales. We describe different effects that take place on different scales and play major roles in the scenario of interaction of ions with tissue. The understanding of these effects allows an assessment of relative biological effectiveness that relates the physical quantities, such as dose, to the biological values, such as the probability of cell survival.

  1. Ion-Induced Beam Instability in an Electron Storage Ring

    Institute of Scientific and Technical Information of China (English)

    LI Yong-Jun; JIN Yu-Ming; LI Wei-Min; LIU Zu-Ping

    2000-01-01

    In a small electron storage ring, such as the Hefei Light Source (HLS) ring, the newly generated ions, which can not escape from the beam potential and then are trapped from turn to turn, will lead to the beam instability. The ions created by the leading bunches can perturb the trailing bunches and also themselves during their subsequent passage, which will make the amplitude of beam oscillation be damped and anti-damped periodically. A computer simulation based on the strong-weak model shows a good agreement with our analytical model using the linear theory.

  2. Injection to the pick-up ion regime from high energies and induced ion power laws

    CERN Document Server

    Fahr, H -J; Verscharen, D

    2008-01-01

    Though pick-up ions (PUIs) are a well known phenomenon in the inner heliosphere, their phase-space distribution nevertheless is a theoretically unsettled problem. Especially the question of how pick-up ions form their suprathermal tails, extending to far above their injection energies, still now is unsatistactorily answered. Though Fermi-2 velocity diffusion theories have revealed that such tails are populated, they nevertheless show that resulting population densities are much less than seen in observations showing power-laws with a velocity index of ``-5''. We first investigate here, whether or not observationally suggested power-laws can be the result of a quasi-equilibrium state between suprathermal ions and magnetohydrodynamic turbulences in energy exchange with eachother. We demonstrate that such an equilibrium cannot be established. We furthermore show that Fermi-2 type energy diffusion in the outer heliosphere is too inefficient to determine the shape of the distribution function there. As we can show...

  3. Ion-Sputter-Induced Nanodots on Si(11O): Ion Energy Dependence

    Institute of Scientific and Technical Information of China (English)

    LI Wei-Qing; LING Li; QI Le-Jun; YANG Xin-Ju; FAN Wen-Bin; GU Chang-Xin; LU Ming

    2005-01-01

    @@ Nanodot arrays were formed on Si(110) surface under normal-incident Ar+ ion sputtering at substrate temperature of 800 ℃.Theion flux was 20μA/cm2, and the ion energies were 1-5keV.The surface was imaged by an atomic force microscope (AFM).It was found that with the increasing ion energy, the average ellipticity of the dots changes in an oscillating manner; meanwhile the average dot size increases monotonously.Based on a dynamic continuum model, and taking into consideration the asymmetry of the Ehrlich-Schwoebel diffusions along the and crystallographic directions, we carry out the simulations, which reproduce the experimental results qualitatively.

  4. Comparative Evaluation of Aluminum Sulfate and Ferric Sulfate-Induced Coagulations as Pretreatment of Microfiltration for Treatment of Surface Water.

    Science.gov (United States)

    Song, Yali; Dong, Bingzhi; Gao, Naiyun; Deng, Yang

    2015-06-12

    Two coagulants, aluminum sulfate and ferric chloride, were tested to reduce natural organic matter (NOM) as a pretreatment prior to polyvinylidene fluoride (PVDF) microfiltration (MF) membranes for potable water treatment. The results showed that the two coagulants exhibited different treatment performance in NOM removal. Molecular weight (MW) distributions of NOM in the tested surface raw water were concentrated at 3-5 kDa and approximately 0.2 kDa. Regardless of the coagulant species and dosages, the removal of 0.2 kDa NOM molecules was limited. In contrast, NOM at 3-5 kDa were readily removed with increasing coagulant dosages. In particular, aluminum sulfate favorably removed NOM near 5 kDa, whereas ferric chloride tended to reduce 3 kDa organic substances. Although aluminum sulfate and ferric chloride could improve the flux of the ensuing MF treatment, the optimal coagulant dosages to achieve effective pretreatment were different: 2-30 mg/L for aluminum sulfate and >15 mg/L for ferric chloride. The scanning electron microscope (SEM) image of the membrane-filtered coagulated raw water showed that coagulation efficiency dramatically affected membrane flux and that good coagulation properties can reduce membrane fouling.

  5. Comparative Evaluation of Aluminum Sulfate and Ferric Sulfate-Induced Coagulations as Pretreatment of Microfiltration for Treatment of Surface Water

    Directory of Open Access Journals (Sweden)

    Yali Song

    2015-06-01

    Full Text Available Two coagulants, aluminum sulfate and ferric chloride, were tested to reduce natural organic matter (NOM as a pretreatment prior to polyvinylidene fluoride (PVDF microfiltration (MF membranes for potable water treatment. The results showed that the two coagulants exhibited different treatment performance in NOM removal. Molecular weight (MW distributions of NOM in the tested surface raw water were concentrated at 3–5 kDa and approximately 0.2 kDa. Regardless of the coagulant species and dosages, the removal of 0.2 kDa NOM molecules was limited. In contrast, NOM at 3–5 kDa were readily removed with increasing coagulant dosages. In particular, aluminum sulfate favorably removed NOM near 5 kDa, whereas ferric chloride tended to reduce 3 kDa organic substances. Although aluminum sulfate and ferric chloride could improve the flux of the ensuing MF treatment, the optimal coagulant dosages to achieve effective pretreatment were different: 2–30 mg/L for aluminum sulfate and >15 mg/L for ferric chloride. The scanning electron microscope (SEM image of the membrane-filtered coagulated raw water showed that coagulation efficiency dramatically affected membrane flux and that good coagulation properties can reduce membrane fouling.

  6. Structural changes of DNA in heavy ion-induced mutants on Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Tano, S.; Shikazono, N.; Tanaka, A.; Yokota, Y.; Watanabe, H. [Japan Atomic Research Research Inst., Watanuki, Takasaki (Japan). Advanced Science Research Center

    1997-09-01

    In order to investigate the frequency of structural changes induced by high LET radiation in plants, a comparison was made between DNA fragments amplified by the polymerase chain reaction (PCR) from C ion- and electron-induced Arabidopsis mutants at GL and TT loci. (orig./MG)

  7. Measurements of induced activity in concrete by secondary particles at forward direction produced by intermediate energy heavy ions on an Fe target

    Science.gov (United States)

    Ogawa, T.; Morev, M. N.; Iimoto, T.; Kosako, T.

    2011-09-01

    Spallation and neutron capture reaction rate distributions were measured using activation detectors inside a 90-cm thick ordinary concrete pile exposed to a field of secondary particles escaping a thick (stopping length) iron target bombarded with various intermediate energy ions, 230 MeV/u He, 400 MeV/u C, and 800 MeV/u Si. Activation detectors of aluminum, bismuth, gold, and gold covered with cadmium were inserted at various depths in the concrete pile. In addition, the distributions of activation reaction rate were simulated by FLUKA and PHITS Monte-Carlo codes. Generally, comparison of measured and calculated reaction rates show agreement within a factor of two. The experimental data will be useful for benchmarking Monte-Carlo radiation transport simulation code capabilities in estimating radioactivity induced in accelerator radiation shielding.

  8. ION-IMPACT-INDUCED FRAGMENTATION OF WATER-MOLECULES

    NARCIS (Netherlands)

    WERNER, U; BECKORD, K; BECKER, J; FOLKERTS, HO; LUTZ, HO

    1995-01-01

    The multiple ionization and fragmentation of H2O by fast H+, He+, O6+ and O7+ ions was studied utilizing a position- and time-sensitive multi-particle detector which allows the coincident measurement of the momenta of correlated fragments. Thereby, the fragmentation energy and angular correlations f

  9. Electron dynamics at surfaces induced by highly charged ions

    NARCIS (Netherlands)

    Morgenstern, R

    1998-01-01

    Energy spectra of electrons resulting from hydrogen-like multiply charged N6+ and Q(7+) ions on various surfaces are presented and discussed. Por metal target surfaces thr formation and decay of hollow atoms during the approach towards the surface is rather well understood in terms of the classical

  10. Electron dynamics at surfaces induced by highly charged ions

    NARCIS (Netherlands)

    Morgenstern, R

    Energy spectra of electrons resulting from hydrogen-like multiply charged N6+ and Q(7+) ions on various surfaces are presented and discussed. Por metal target surfaces thr formation and decay of hollow atoms during the approach towards the surface is rather well understood in terms of the classical

  11. Complexation-induced supramolecular assembly drives metal-ion extraction.

    Science.gov (United States)

    Ellis, Ross J; Meridiano, Yannick; Muller, Julie; Berthon, Laurence; Guilbaud, Philippe; Zorz, Nicole; Antonio, Mark R; Demars, Thomas; Zemb, Thomas

    2014-09-26

    Combining experiment with theory reveals the role of self-assembly and complexation in metal-ion transfer through the water-oil interface. The coordinating metal salt Eu(NO3)3 was extracted from water into oil by a lipophilic neutral amphiphile. Molecular dynamics simulations were coupled to experimental spectroscopic and X-ray scattering techniques to investigate how local coordination interactions between the metal ion and ligands in the organic phase combine with long-range interactions to produce spontaneous changes in the solvent microstructure. Extraction of the Eu(3+)-3(NO3(-)) ion pairs involves incorporation of the "hard" metal complex into the core of "soft" aggregates. This seeds the formation of reverse micelles that draw the water and "free" amphiphile into nanoscale hydrophilic domains. The reverse micelles interact through attractive van der Waals interactions and coalesce into rod-shaped polynuclear Eu(III) -containing aggregates with metal centers bridged by nitrate. These preorganized hydrophilic domains, containing high densities of O-donor ligands and anions, provide improved Eu(III) solvation environments that help drive interfacial transfer, as is reflected by the increasing Eu(III) partitioning ratios (oil/aqueous) despite the organic phase approaching saturation. For the first time, this multiscale approach links metal-ion coordination with nanoscale structure to reveal the free-energy balance that drives the phase transfer of neutral metal salts.

  12. Oxygen ion implantation induced microstructural changes and electrical conductivity in Bakelite RPC detector material

    Science.gov (United States)

    Kumar, K. V. Aneesh; Ranganathaiah, C.; Kumarswamy, G. N.; Ravikumar, H. B.

    2016-05-01

    In order to explore the structural modification induced electrical conductivity, samples of Bakelite Resistive Plate Chamber (RPC) detector materials were exposed to 100 keV Oxygen ion in the fluences of 1012, 1013, 1014 and 1015 ions/cm2. Ion implantation induced microstructural changes have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and X-Ray Diffraction (XRD) techniques. Positron lifetime parameters viz., o-Ps lifetime and its intensity shows the deposition of high energy interior track and chain scission leads to the formation of radicals, secondary ions and electrons at lower ion implantation fluences (1012 to1014 ions/cm2) followed by cross-linking at 1015 ions/cm2 fluence due to the radical reactions. The reduction in electrical conductivity of Bakelite detector material is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate implantation energy and fluence of Oxygen ion on polymer based Bakelite RPC detector material may reduce the leakage current, improves the efficiency, time resolution and thereby rectify the aging crisis of the RPC detectors.

  13. Oxygen ion implantation induced microstructural changes and electrical conductivity in Bakelite RPC detector material

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, K. V. Aneesh, E-mail: aneesh1098@gmail.com; Ravikumar, H. B., E-mail: hbr@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Mysore-570006 (India); Ranganathaiah, C., E-mail: cr@physics.uni-mysore.ac.in [Govt. Research Centre, Sahyadri Educational Institutions, Mangalore-575007 (India); Kumarswamy, G. N., E-mail: kumy79@gmail.com [Department of Studies in Physics, Amrita Vishwa Vidyapeetham, Bangalore-560035 (India)

    2016-05-06

    In order to explore the structural modification induced electrical conductivity, samples of Bakelite Resistive Plate Chamber (RPC) detector materials were exposed to 100 keV Oxygen ion in the fluences of 10{sup 12}, 10{sup 13}, 10{sup 14} and 10{sup 15} ions/cm{sup 2}. Ion implantation induced microstructural changes have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and X-Ray Diffraction (XRD) techniques. Positron lifetime parameters viz., o-Ps lifetime and its intensity shows the deposition of high energy interior track and chain scission leads to the formation of radicals, secondary ions and electrons at lower ion implantation fluences (10{sup 12} to10{sup 14} ions/cm{sup 2}) followed by cross-linking at 10{sup 15} ions/cm{sup 2} fluence due to the radical reactions. The reduction in electrical conductivity of Bakelite detector material is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate implantation energy and fluence of Oxygen ion on polymer based Bakelite RPC detector material may reduce the leakage current, improves the efficiency, time resolution and thereby rectify the aging crisis of the RPC detectors.

  14. Dynamics of planetary ions in the induced magnetospheres of Venus and Mars

    Science.gov (United States)

    Jarvinen, R.; Brain, D. A.; Luhmann, J. G.

    2016-08-01

    We compare dynamics of planetary ions in the induced magnetospheres of Venus and Mars in a global hybrid simulation to study factors controlling the ion escape at unmagnetized planets. In the simulation we find that the finite Larmor radius (FLR) effects of escaping heavy ions are stronger at Mars than Venus under nominal solar wind conditions. But, varying upstream conditions, especially the IMF, affects the strength of the FLR effects. We classify three basic types of planetary ion dynamics in an induced magnetosphere. First, light ions such as hydrogen follow the E×B drift, and escape in the wake in the hemisphere where the solar wind convection electric field is pointing towards the planet. Second, heavy ions like oxygen undergo FLR effects, and escape mainly outside of the wake in the hemisphere where the solar wind convection electric field is pointing away from the planet. Third, ion species between light and heavy ions can have both the E×B and FLR type dynamics in the same time.

  15. Ion-beam induced atomic mixing in isotopically controlled silicon multilayers

    Science.gov (United States)

    Radek, M.; Bracht, H.; Liedke, B.; Böttger, R.; Posselt, M.

    2016-11-01

    Implantation of germanium (Ge), gallium (Ga), and arsenic (As) into crystalline and preamorphized isotopically controlled silicon (Si) multilayer structures at temperatures between 153 K and 973 K was performed to study the mechanisms mediating ion-beam induced atomic mixing. Secondary-ion-mass-spectrometry was applied to determine concentration-depth profiles of the stable isotopes before and after ion implantation. The intermixing is analytically described by a depth-dependent displacement function. The maximum displacement is found to depend not only on temperature and microstructure but also on the doping type of the implanted ion. Molecular dynamics calculations evaluate the contribution of cascade mixing, i.e., thermal-spike mixing, to the overall observed atomic mixing. Calculated and experimental results on the temperature dependence of ion-beam mixing in the amorphous and crystalline structures provide strong evidence for ion-beam induced enhanced crystallization and enhanced self-diffusion, respectively. On the other hand, the former process is confirmed by channeling Rutherford backscattering analyses of the amorphous layer thickness remaining after implantation, the latter process is consistently attributed to the formation of highly mobile Si di-interstitials formed under irradiation and in the course of damage annealing. The observed ion-beam mixing in Si is compared to recent results on ion-beam mixing of Ge isotope multilayers that, in contrast to Si, are fully described by thermal-spike mixing only.

  16. Estimation of Sputtering Damages on a Magnetron H- Ion Source Induced by Cs+ and H+ Ions

    CERN Document Server

    Pereira, H; Alessi, J; Kalvas, t

    2013-01-01

    An H− ion source is being developed for CERN’s Linac4 accelerator. A beam current requirement of 80 mA and a reliability above 99% during 1 year with 3 month uninterrupted operation periods are mandatory. To design a low-maintenance long life-time source, it is important to investigate and understand the wear mechanisms. A cesiated plasma discharge ion source, such as the BNL magnetron source, is a good candidate for the Linac4 ion source. However, in the magnetron source operated at BNL, the removal of material from the molybdenum cathode and the stainless steel anode cover plate surfaces is visible after extended operation periods. The observed sputtering traces are shown to result from cesium vapors and hydrogen gas ionized in the extraction region and subsequently accelerated by the extraction field. This paper presents a quantitative estimate of the ionization of cesium and hydrogen by the electron and H− beams in the extraction region of BNL’s magnetron ion source. The respective contributions o...

  17. Swift heavy ion irradiation induced nanograin formation in CdTe thin films

    Science.gov (United States)

    Survase, Smita; Narayan, Himanshu; Sulania, I.; Thakurdesai, Madhavi

    2016-11-01

    Swift Heavy Ion (SHI) irradiation is a unique technique for nanograin formation through grain fragmentation. Contrary to the generally reported SHI irradiation induced grain growth on CdTe thin films, we report fragmentation leading to nanograin formation. Thermally evaporated polycrystalline CdTe thin films were irradiated with 100 MeV 197Au, 107Ag and 58Ni ions beams up to a fluence of 5 × 1012 ions/cm2. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were carried out for surface analysis before and after irradiation. SEM micrographs indicate that the larger grains in the as-deposited films were fragmented into smaller grains due to irradiation. The extent of fragmentation was found to increase with increasing electronic energy loss (Se). AFM pictures also supported the irradiation induced fragmentation. Structural characterization was done using X-ray Diffraction (XRD) technique. The ion induced strain and dislocation density were calculated from the XRD data. Both the strain and dislocation density were found to increase with increasing Se . The observed grain fragmentation is explained on the basis of a combined effect of strain induced disintegration of grains after the Coulomb explosion, and an 'incomplete' re-crystallization of the molten thermal spikes. Moreover, the optical band gap Eg (1.5 eV for as-deposited film), determined from UV-vis spectroscopy, increased with Se, and possibly because of ion induced strain and defect annealing.

  18. Ion-induced nucleation of pure biogenic particles

    CERN Document Server

    Kirkby, Jasper; Sengupta, Kamalika; Frege, Carla; Gordon, Hamish; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K; Wagner, Robert; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill; Dias, antonio; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Krapf, Manuel; Kürten, andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Onnela, antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P; Pringle, Kirsty; Rap, Alexandru; Richards, Nigel A D; Riipinen, Ilona; Rissanen, Matti P; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E; Seinfeld, John H; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander L; Wagner, Andrea C; Wagner, Paul E; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M; Worsnop, Douglas R; Baltensperger, Urs; Kulmala, Markku; Carslaw, Kenneth S; Curtius, Joachim

    2016-01-01

    Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood. Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours. It is thought that sulfuric acid is essential to initiate most particle formation in the atmosphere and that ions have a relatively minor role. Some laboratory studies, however, have reported organic particle formation without the intentional addition of sulfuric acid, although contamination could not be excluded. Here we present evidence for the formation of aerosol particles from highly oxidized biogenic vapours in the absence of sulfuric acid in a large chamber under atmospheric conditions. The highly oxygenated molecules (HOMs) are produced by ozonolysis of $\\alpha$-pinene. We find that ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation. Our experimental findings are supported...

  19. The enhanced anticoagulation for graphene induced by COOH(+) ion implantation.

    Science.gov (United States)

    Liu, Xiaoqi; Cao, Ye; Zhao, Mengli; Deng, Jianhua; Li, Xifei; Li, Dejun

    2015-01-01

    Graphene may have attractive properties for some biomedical applications, but its potential adverse biological effects, in particular, possible modulation when it comes in contact with blood, require further investigation. Little is known about the influence of exposure to COOH(+)-implanted graphene (COOH(+)/graphene) interacting with red blood cells and platelets. In this paper, COOH(+)/graphene was prepared by modified Hummers' method and implanted by COOH(+) ions. The structure and surface chemical and physical properties of COOH(+)/graphene were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle measurement. Systematic evaluation of anticoagulation, including in vitro platelet adhesion assays and hemolytic assays, proved that COOH(+)/graphene has significant anticoagulation. In addition, at the dose of 5 × 10(17) ions/cm(2), COOH(+)/graphene responded best on platelet adhesion, aggregation, and platelet activation.

  20. Dynamics of microvortices induced by ion concentration polarization

    CERN Document Server

    de Valenca, Joeri; Lammertink, Rob G H; Tsai, Peichun Amy

    2015-01-01

    We investigate the coupled dynamics of the local hydrodynamics and global electric response of an electrodialysis system, which consists of an electrolyte solution adjacent to a charge selective membrane under electric forcing. Under a DC electric current, counterions transport through the charged membrane while the passage of co-ions is restricted, thereby developing ion concentration polarization (ICP) or gradients. At sufficiently large currents, simultaneous measurements of voltage drop and flow field reveal several distinct dynamic regimes. Initially, the electrodialysis system displays a steady Ohmic voltage difference ($\\Delta V_{ohm}$), followed by a constant voltage jump ($\\Delta V_c$). Immediately after this voltage increase, micro-vortices set in and grow both in size and speed with time. After this growth, the resultant voltage levels off around a fixed value. The average vortex size and speed stabilize as well, while the individual vortices become unsteady and dynamic. These quantitative results ...

  1. Surface induced reactivity for titanium by ion implantation.

    Science.gov (United States)

    Pham, M T; Reuther, H; Matz, W; Mueller, R; Steiner, G; Oswald, S; Zyganov, I

    2000-06-01

    Calcium and phosphorus storage in a thin layer of titanium surface was achieved by ion implantation. We study the reactivity of this surface in response to a hydrothermal treatment. The incipient implanted species are observed to convert to Ca(2+) and PO(4)(3-), the precursors for generating calcium phosphate polymorphs. Hydroxyapatite is formed from these precursors by an interface-liquid mediated mineralization preceded by the hydrolysis of oxygen compounds of Ca and P from the solid phase. The morphology and organization of apatite mineral is controlled by the fluid dynamics reflecting the surface remodeling to adapt to the available local environment. Exposed to calcium and phosphate ion containing solution, the hydrothermally treated surface templates hydroxyapatite deposition. Ca and P implanted Ti surface was shown to be chemically and morphologically actively involved in the interfacial reactions.

  2. Degradation of the solid electrolyte interphase induced by the deposition of manganese ions

    Science.gov (United States)

    Shin, Hosop; Park, Jonghyun; Sastry, Ann Marie; Lu, Wei

    2015-06-01

    The deposition of manganese ions dissolved from the cathode onto the interface between the solid electrolyte interphase (SEI) and graphite causes severe capacity fading in manganese oxide-based cells. The evolution of the SEI layer containing these Mn compounds and the corresponding instability of the layer are thoroughly investigated by artificially introducing soluble Mn ions into a 1 mol L-1 LiPF6 electrolyte solution. Deposition of dissolved Mn ions induces an oxygen-rich SEI layer that results from increased electrolyte decomposition, accelerating SEI growth. The spatial distribution of Mn shows that dissolved Mn ions diffuse through the porous layer and are deposited mostly at the inorganic layer/graphite interface. The Mn compound deposited on the anode, identified as MnF2, originates from a metathesis reaction between LiF and dissolved Mn ion. It is confirmed that ion-exchange reaction occurs in the inorganic layer, converting SEI species to Mn compounds. Some of the Mn is observed inside the graphite; this may cause surface structural disordering in the graphite, limiting lithium-ion intercalation. The continuous reaction that occurs at the inorganic layer/graphite interfacial regions and the modification of the original SEI layer in the presence of Mn ions are critically related to capacity fade and impedance rise currently plaguing Li-ion cells.

  3. Ion beam damage assessment and waveguide formation induced by energetic Si-ion irradiation in lanthanum aluminate crystal

    Science.gov (United States)

    Liu, Y.; Huang, Q.; Crespillo, M. L.; Qiao, M.; Liu, P.; Wang, X. L.

    2017-02-01

    Lanthanum aluminate (LaAlO3) crystal has emerged as one of the most valuable functional-materials, and its physical, electronic and optical properties strongly depend on the crystal structure, which can be easily altered in an irradiation environment and therefore affect the performance of LaAlO3-based devices. On the other hand, the preparation of LaAlO3 waveguide is also a scientific challenge for its potential application prospects in optoelectronics field. In this work, the damage evolution behavior of LaAlO3 crystal under Si-ion irradiation has been discussed in detail utilizing complementary characterization techniques, and then, single-mode waveguide of LaAlO3 crystal in the visible band can be obtained based on ion-irradiation-induced lattice damage behavior. Waveguide optical-coupling techniques are used to show its competitive features. Thus, novel optical waveguides with optimized features in LaAlO3 crystals can be tailored by a proper selection of ion mass, energy and fluence using the modification of the target material during ion irradiation process.

  4. Monte Carlo simulation of K ionization induced by ions in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    L`Hoir, A.; Chetioui, A.; Guiraud, L.; Herve du Penhoat, M.A.; Politis, M.F.; Touati, A. [GPS, Universite, CNRS, 75 - Paris (France); Bouffard, S.; Gervais, B. [CIRIL, UMR, CEA-CNRS, 14 - Caen (France); Sabatier, L. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France)

    1997-03-01

    A simple analytical model has evidences a strong correlation between experimental cross sections of inactivation by heavy ions and K-vacancy cross sections in C, O atoms of DNA. We present here a more detailed analysis based on a full Monte-Carlo simulation of K ionizations induced by the primary ion itself and by secondary electrons. This simulation has been used to perform further tests of the K-model for inactivation, especially: comparison of lethal efficiencies of K ionizations induced either by ions or by electrons: these are extracted from a fit of experimental inactivation cross sections electron contributions) dominate; comparison of experimental and calculated inactivation cross sections as a function of the impact parameter of the ion with respect to cell nucleus. (authors)

  5. Dependence of ion-induced Pd-silicide formation on nuclear energy deposition density

    Energy Technology Data Exchange (ETDEWEB)

    Horino, Yuji; Matsunami, Noriaki; Itoh, Noriaki

    1986-05-01

    Pd/sub 2/Si formation at the Pd-Si interface induced by irradiation with ions having a wide range of nuclear energy of deposition density has been investigated. It is found that the thickness of the silicide layer formed by irradiation is proportional to the ion fluence for irradiation with ions having low energy-deposition densities, while it is proportional to the square root of the fluence for irradiation with ions having energy-deposition densities. The results indicate that Pd/sub 2/Si formation is reaction limited when the energy-deposition density at the interface is low and is diffusion limited when it is high. The results are compared with the phenomenological theory developed by Horino et al. and it is shown that such a dependence of the limiting processes on the energy depositon density is induced when the diffusion is thermally activated while the reaction at the interface is radiation-enhanced.

  6. Transfer and transport of aluminum in filtration unit

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Aluminum salt coagulants were used prevalently in various water works. In this article, the effects of filtration on residual aluminum concentration and species distribution were researched by determining the concentration of different Aluminum species before and after single layer filter, double layer filter, and membrane filtration units. In the research, size exclusion chromatography (SEC) was used to separate colloidal and soluble aluminum, ion exchange chromatography (IEC) was used to separate organic and inorganic aluminum, and inductivity coupled plasma-atomic emission spectrometry (ICP-AES) was used to determine the aluminum concentration. The results showed that the rapid filtration process had the ability of removing residual aluminum from coagulant effluent water, and that double layer filtration was more effective in residual aluminum removal than single layer filtration, while Nano filtration was more effective than micro filtration. It was found that when the residual aluminum concentration was below 1mg/L in sediment effluent, the residual aluminum concentration in treated water was above 0.2 mg/L. The direct rapid filtration process mainly removed the suspended aluminum. The removal of soluble and colloidal aluminum was always less than 10% and the natural small particles that adsorbed the amount of soluble or small particles aluminum on their surface were difficult to be removed in this process. Micro filtration and nano filtration were good technologies for removing aluminum; the residual aluminum concentration in the effluent was less than 0.05 mg/L.

  7. Heavy-ion-induced desorption of organic molecules studied with Langmuir-Blodgett multilayer systems (DE)

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.; Schoppmann, C.; Brandl, D.; Ostrowski, A.; Voit, H. (Physikalisches Institut der Universitaet Erlangen-Nuernberg D-8520 Erlangen, (Germany)); Johannsmann, D.; Knoll, W. (Max-Planck-Institut fuer Polymerforschung Mainz D-6500 Mainz, (Germany))

    1991-07-01

    Heavy-ion-induced desorption has been studied with samples consisting of Langmuir-Blodgett films made from Cd salts of fatty acids. The experiments confirm the result of previous works that heavy ions drill a crater into the sample surface. The explicit dependence of the crater depth on the electronic energy loss could be determined from the experiments. The craters exhibit the shape of a symmetric cone as obtained from a desorption model applied to the experimental data.

  8. Blood-brain barrier flux of aluminum, manganese, iron and other metals suspected to contribute to metal-induced neurodegeneration.

    Science.gov (United States)

    Yokel, Robert A

    2006-11-01

    The etiology of many neurodegenerative diseases has been only partly attributed to acquired traits, suggesting environmental factors may also contribute. Metal dyshomeostasis causes or has been implicated in many neurodegenerative diseases. Metal flux across the blood-brain barrier (the primary route of brain metal uptake) and the choroid plexuses as well as sensory nerve metal uptake from the nasal cavity are reviewed. Transporters that have been described at the blood-brain barrier are listed to illustrate the extensive possibilities for moving substances into and out of the brain. The controversial role of aluminum in Alzheimer's disease, evidence suggesting brain aluminum uptake by transferrin-receptor mediated endocytosis and of aluminum citrate by system Xc;{-} and an organic anion transporter, and results suggesting transporter-mediated aluminum brain efflux are reviewed. The ability of manganese to produce a parkinsonism-like syndrome, evidence suggesting manganese uptake by transferrin- and non-transferrin-dependent mechanisms which may include store-operated calcium channels, and the lack of transporter-mediated manganese brain efflux, are discussed. The evidence for transferrin-dependent and independent mechanisms of brain iron uptake is presented. The copper transporters, ATP7A and ATP7B, and their roles in Menkes and Wilson's diseases, are summarized. Brain zinc uptake is facilitated by L- and D-histidine, but a transporter, if involved, has not been identified. Brain lead uptake may involve a non-energy-dependent process, store-operated calcium channels, and/or an ATP-dependent calcium pump. Methyl mercury can form a complex with L-cysteine that mimics methionine, enabling its transport by the L system. The putative roles of zinc transporters, ZnT and Zip, in regulating brain zinc are discussed. Although brain uptake mechanisms for some metals have been identified, metal efflux from the brain has received little attention, preventing integration of

  9. Plasmon-induced selective carbon dioxide conversion on earth-abundant aluminum-cuprous oxide antenna-reactor nanoparticles.

    Science.gov (United States)

    Robatjazi, Hossein; Zhao, Hangqi; Swearer, Dayne F; Hogan, Nathaniel J; Zhou, Linan; Alabastri, Alessandro; McClain, Michael J; Nordlander, Peter; Halas, Naomi J

    2017-06-21

    The rational combination of plasmonic nanoantennas with active transition metal-based catalysts, known as 'antenna-reactor' nanostructures, holds promise to expand the scope of chemical reactions possible with plasmonic photocatalysis. Here, we report earth-abundant embedded aluminum in cuprous oxide antenna-reactor heterostructures that operate more effectively and selectively for the reverse water-gas shift reaction under milder illumination than in conventional thermal conditions. Through rigorous comparison of the spatial temperature profile, optical absorption, and integrated electric field enhancement of the catalyst, we have been able to distinguish between competing photothermal and hot-carrier driven mechanistic pathways. The antenna-reactor geometry efficiently harnesses the plasmon resonance of aluminum to supply energetic hot-carriers and increases optical absorption in cuprous oxide for selective carbon dioxide conversion to carbon monoxide with visible light. The transition from noble metals to aluminum based antenna-reactor heterostructures in plasmonic photocatalysis provides a sustainable route to high-value chemicals and reaffirms the practical potential of plasmon-mediated chemical transformations.Plasmon-enhanced photocatalysis holds promise for the control of chemical reactions. Here the authors report an Al@Cu2O heterostructure based on earth abundant materials to transform CO2 into CO at significantly milder conditions.

  10. Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)

    Energy Technology Data Exchange (ETDEWEB)

    Sideras-Haddad, E.; Schenkel, T.; Shrivastava, S.; Makgato, T.; Batra, A.; Weis, C. D.; Persaud, A.; Erasmus, R.; Mwakikunga, B.

    2009-01-06

    The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highly oriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosizeareas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.

  11. Synthetic ion transporters can induce apoptosis by facilitating chloride anion transport into cells.

    Science.gov (United States)

    Ko, Sung-Kyun; Kim, Sung Kuk; Share, Andrew; Lynch, Vincent M; Park, Jinhong; Namkung, Wan; Van Rossom, Wim; Busschaert, Nathalie; Gale, Philip A; Sessler, Jonathan L; Shin, Injae

    2014-10-01

    Anion transporters based on small molecules have received attention as therapeutic agents because of their potential to disrupt cellular ion homeostasis. However, a direct correlation between a change in cellular chloride anion concentration and cytotoxicity has not been established for synthetic ion carriers. Here we show that two pyridine diamide-strapped calix[4]pyrroles induce coupled chloride anion and sodium cation transport in both liposomal models and cells, and promote cell death by increasing intracellular chloride and sodium ion concentrations. Removing either ion from the extracellular media or blocking natural sodium channels with amiloride prevents this effect. Cell experiments show that the ion transporters induce the sodium chloride influx, which leads to an increased concentration of reactive oxygen species, release of cytochrome c from the mitochondria and apoptosis via caspase activation. However, they do not activate the caspase-independent apoptotic pathway associated with the apoptosis-inducing factor. Ion transporters, therefore, represent an attractive approach for regulating cellular processes that are normally controlled tightly by homeostasis.

  12. Trapped-ion probing of light-induced charging effects on dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Harlander, M; Brownnutt, M; Haensel, W; Blatt, R, E-mail: max.harlander@uibk.ac.a [Institut fuer Experimentalphysik, Universitaet Innsbruck, Technikerstrasse 25, A-6020 Innsbruck (Austria)

    2010-09-15

    We use a string of confined {sup 40}Ca{sup +} ions to measure perturbations to a trapping potential which are caused by the light-induced charging of an antireflection-coated window and of insulating patches on the ion-trap electrodes. The electric fields induced at the ions' position are characterized as a function of distance to the dielectric and as a function of the incident optical power and wavelength. The measurement of the ion-string position is sensitive to as few as 40 elementary charges per {radical}(Hz) on the dielectric at distances of the order of millimetres, and perturbations are observed for illuminations with light of wavelengths as large as 729 nm. This has important implications for the future of miniaturized ion-trap experiments, notably with regard to the choice of electrode material and the optics that must be integrated in the vicinity of the ion. The method presented here can be readily applied to the investigation of charging effects beyond the context of ion-trap experiments.

  13. Ultrafast opacity in borosilicate glass induced by picosecond bursts of laser-driven ions

    CERN Document Server

    Dromey, B; Adams, D; Prasad, R; Kakolee, K F; Stefanuik, R; Nersisyan, G; Sarri, G; Yeung, M; Ahmed, H; Doria, D; Dzelzainis, T; Jung, D; Kar, S; Marlow, D; Romagnani, L; Correa, A A; Dunne, P; Kohanoff, J; Schleife, A; Borghesi, M; Currell, F; Riley, D; Zepf, M; Lewis, C L S

    2014-01-01

    Direct investigation of ion-induced dynamics in matter on picosecond (ps, 10-12 s) timescales has been precluded to date by the relatively long nanosecond (ns, 10-9 s) scale ion pulses typically provided by radiofrequency accelerators1. By contrast, laser-driven ion accelerators provide bursts of ps duration2, but have yet to be applied to the study of ultrafast ion-induced transients in matter. We report on the evolution of an electron-hole plasma excited in borosilicate glass by such bursts. This is observed as an onset of opacity to synchronised optical probe radiation and is characterised by the 3.0 +/- 0.8 ps ion pump rise-time . The observed decay-time of 35 +/- 3 ps i.e. is in excellent agreement with modelling and reveals the rapidly evolving electron temperature (>10 3 K) and carrier number density (>10 17cm-3). This result demonstrates that ps laser accelerated ion bursts are directly applicable to investigating the ultrafast response of matter to ion interactions and, in particular, to ultrafast pu...

  14. A synthetic ion transporter that disrupts autophagy and induces apoptosis by perturbing cellular chloride concentrations

    Science.gov (United States)

    Busschaert, Nathalie; Park, Seong-Hyun; Baek, Kyung-Hwa; Choi, Yoon Pyo; Park, Jinhong; Howe, Ethan N. W.; Hiscock, Jennifer R.; Karagiannidis, Louise E.; Marques, Igor; Félix, Vítor; Namkung, Wan; Sessler, Jonathan L.; Gale, Philip A.; Shin, Injae

    2017-07-01

    Perturbations in cellular chloride concentrations can affect cellular pH and autophagy and lead to the onset of apoptosis. With this in mind, synthetic ion transporters have been used to disturb cellular ion homeostasis and thereby induce cell death; however, it is not clear whether synthetic ion transporters can also be used to disrupt autophagy. Here, we show that squaramide-based ion transporters enhance the transport of chloride anions in liposomal models and promote sodium chloride influx into the cytosol. Liposomal and cellular transport activity of the squaramides is shown to correlate with cell death activity, which is attributed to caspase-dependent apoptosis. One ion transporter was also shown to cause additional changes in lysosomal pH, which leads to impairment of lysosomal enzyme activity and disruption of autophagic processes. This disruption is independent of the initiation of apoptosis by the ion transporter. This study provides the first experimental evidence that synthetic ion transporters can disrupt both autophagy and induce apoptosis.

  15. Changes in Storage Properties of Hydrides Induced by Ion Irradiation

    Directory of Open Access Journals (Sweden)

    Jasmina GRBOVIĆ NOVAKOVIĆ

    2013-05-01

    Full Text Available The influence of structural changes caused by irradiation with different ions, their energies and fluences on sorption properties has been investigated. Results suggest that there are several mechanisms of desorption depending on defect concentration, their interaction and ordering. It has been also demonstrated that the changes in near-surface area play the crucial role in hydrogen desorption kinetics. It is confirmed that there is possibility to control the thermodynamic parameters of these systems by controlling vacancies depth profile and concentration. DOI: http://dx.doi.org/10.5755/j01.ms.19.2.1579

  16. Ion-beam induced isolation of gallium arsenide layers

    Science.gov (United States)

    Sengupta, D.; Zemanski, J. M.; Williams, J. S.; Johnson, S. T.; Pogany, A. P.

    1989-07-01

    Epitaxial (n +-n) layers on semi-insulating GaAs samples were implanted with 60 keV He + ions at elevated temperatures. Samples were analysed to provide sheet resistivity, Hall mobility and carrier depth profiles using electrical measurement techniques and damage distributions using TEM and Rutherford backscattering and channeling. All of the data were correlated to identify the optimum conditions to achieve electrical isolation. Elevated temperature He + implants have been found to create uniform, single step isolation of GaAs layers. Isolation of the GaAs layers can be enhanced and stabilised further by a suitable post-implantation annealing process.

  17. Changes in Storage Properties of Hydrides Induced by Ion Irradiation

    Directory of Open Access Journals (Sweden)

    Jasmina GRBOVIĆ NOVAKOVIĆ

    2013-05-01

    Full Text Available The influence of structural changes caused by irradiation with different ions, their energies and fluences on sorption properties has been investigated. Results suggest that there are several mechanisms of desorption depending on defect concentration, their interaction and ordering. It has been also demonstrated that the changes in near-surface area play the crucial role in hydrogen desorption kinetics. It is confirmed that there is possibility to control the thermodynamic parameters of these systems by controlling vacancies depth profile and concentration. DOI: http://dx.doi.org/10.5755/j01.ms.19.2.1579

  18. Combined Use of Post-Ion Mobility/Collision-Induced Dissociation and Chemometrics for b Fragment Ion Analysis

    Science.gov (United States)

    Zekavat, Behrooz; Miladi, Mahsan; Becker, Christopher; Munisamy, Sharon M.; Solouki, Touradj

    2013-09-01

    Although structural isomers may yield indistinguishable ion mobility (IM) arrival times and similar fragment ions in tandem mass spectrometry (MS), it is demonstrated that post-IM/collision-induced dissociation MS (post-IM/CID MS) combined with chemometrics can enable independent study of the IM-overlapped isomers. The new approach allowed us to investigate the propensity of selected b type fragment ions from AlaAlaAlaHisAlaAlaAla-NH2 (AAA(His)AAA) heptapeptide to form different isomers. Principle component analysis (PCA) of the unresolved post-IM/CID profiles indicated the presence of two different isomer types for b4 +, b5 +, and b6 + and a single isomer type for b7 + fragments of AAA(His)AAA. We employed a simple-to-use interactive self-modeling mixture analysis (SIMPLISMA) to calculate the total IM profiles and CID mass spectra of b fragment isomers. The deconvoluted CID mass spectra showed discernible fragmentation patterns for the two isomers of b4 +, b5 +, and b6 + fragments. Under our experimental conditions, calculated percentages of the "cyclic" isomers (at the 95 % confidence level for n = 3) for b4 +, b5 +, and b6 + were 61 (± 5) %, 36 (± 5) %, and 48 (± 2) %, respectively. Results from the SIMPLISMA deconvolution of b5 + species resembled the CID MS patterns of fully resolved IM profiles for the two b5 + isomers. The "cyclic" isomers for each of the two-component b fragment ions were less susceptible to ion fragmentation than their "linear" counterparts.

  19. Ion induced changes in the structure of bordered pit membranes.

    Science.gov (United States)

    Lee, Jinkee; Holbrook, N Michele; Zwieniecki, Maciej A

    2012-01-01

    Ion-mediated changes in xylem hydraulic resistance are hypothesized to result from hydrogel like properties of pectins located in the bordered pit membranes separating adjacent xylem vessels. Although the kinetics of the ion-mediated changes in hydraulic resistance are consistent with the swelling/deswelling behavior of pectins, there is no direct evidence of this activity. In this report we use atomic force microscopy (AFM) to investigate structural changes in bordered pit membranes associated with changes in the ionic concentration of the surrounding solution. When submerged in de-ionized water, AFM revealed bordered pit membranes as relatively smooth, soft, and lacking any sharp edges surface, in contrast to pictures from scanning electron microscope (SEM) or AFM performed on air-dry material. Exposure of the bordered pit membranes to 50 mM KCl solution resulted in significant changes in both surface physical properties and elevation features. Specifically, bordered pit membranes became harder and the fiber edges were clearly visible. In addition, the membrane contracted and appeared much rougher due to exposed microfibers. In neither solution was there any evidence of discrete pores through the membrane whose dimensions were altered in response to the ionic composition of the surrounding solution. Instead the variable hydraulic resistance appears to involve changes in the both the permeability and the thickness of the pit membrane.

  20. Hydrogen-induced defects in ion-implanted Si

    Science.gov (United States)

    Socher, S.; Lavrov, E. V.; Weber, J.

    2012-09-01

    Single crystalline silicon implanted with 28Si ions and subsequently hydrogenated from an rf plasma at 200∘C is studied by Raman and photoluminescence spectroscopy. A broad Raman band at 3830 cm-1 previously assigned to the rovibrational transitions of hydrogen molecules trapped in Si multivacancies [Ishioka , Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.60.10852 60, 10852 (1999)] reveals a complex line shape at 60 K. In contrast, our study correlates the Raman band to three different localized traps for hydrogen molecules which are identified from the dependence on the ion dose and annealing behavior. Each of these traps, which is saturated with H2, gives rise to three Raman transitions due to para- and ortho-H2. The H2 signals are shown to correlate with the Si-H vibrational modes at 1888, 1930, and 1964 cm-1. Ortho to para conversion rates of H2 at 77 K and room temperature were found to be 62±15 and 8±2 h, respectively.

  1. 化学增强铝硅酸盐玻璃扩散性能研究%The Diffusion Performance of Potassium and Sodium in Ion Exchanged Aluminum Silicate Glass

    Institute of Scientific and Technical Information of China (English)

    程金树; 赵薇; 肖子凡

    2012-01-01

    了解碱金属离子在玻璃表面的扩散对生产高强度铝硅酸盐系统离子交换玻璃具有重要意义.通过外加Al,讨论不同Al/Na对碱离子扩散影响.采用EPMA测得玻璃断面K+、Na+分布曲线,根据Boltzmann- Matano计算方法得到K+、Na+的扩散系数,根据Arrhenius公式计算得到K+、Na+的扩散活化能.实验证明,随着Al/Na的增加,K+、Na+扩散深度逐渐增加,互扩散系数逐渐增加,K+、Na+平均活化能逐渐增加.讨论玻璃体内Al/Na比例是研究高强度离子交换玻璃的一个重要方向.%In the production of ion exchanged aluminum silicate system glass, the alkali ion diffusion on the glass surface is an important process which must be considered. In this paper, we discussed the impact of additional Al on the diffusion of alkali ions. The penetration depth profiles of alkali ions were obtained by EPMA methods. The diffusion coefficients of alkali ions were calculated by Boltzmann-Matano equation. And the active energy of alkali ions were gotten by Arrhenius equation. The results showed that the penetration depth, the interdiffusion coefficient and the average active energy increased with the increase of Al/Na ratios. It means the Al/Na ratios have a great effect on the diffusion of alkali i-ons.

  2. Simulation of grain growth in nanocrystalline nickel induced by ion irradiation

    CERN Document Server

    Voegeli, W; Hahn, H

    2003-01-01

    Molecular dynamics simulations of 5 keV cascades in nanocrystalline nickel with grain sizes of 5 and 10 nm are presented. If the spike volume is exceeding the grain size or overlapping the grain boundary (GB) area we observe ion-beam induced grain growth for both grain sizes. In contrast cascades located in the grain volume lead to the formation of vacancies and interstitials, where the latter are mostly accommodated by the GBs upon annealing. Finally, we show that ion-beam induced grain growth is a direct result of recrystallisation of the thermal spike and therefore inherently different to grain growth observed in long time thermal annealing simulations.

  3. Nanomolar aluminum induces expression of the inflammatory systemic biomarker C-reactive protein (CRP) in human brain microvessel endothelial cells (hBMECs).

    Science.gov (United States)

    Alexandrov, Peter N; Kruck, Theodore P A; Lukiw, Walter J

    2015-11-01

    C-reactive protein (CRP; also known as pentraxin 1, PTX1), a 224 amino acid soluble serum protein organized into a novel pentameric ring-shaped structure, is a highly sensitive pathogenic biomarker for systemic inflammation. High CRP levels are found in practically every known inflammatory state, and elevated CRP levels indicate an increased risk for several common age-related human degenerative disorders, including cardiovascular disease, cancer, diabetes, and Alzheimer's disease (AD). While the majority of CRP is synthesized in the liver for secretion into the systemic circulation, it has recently been discovered that an appreciable amount of CRP is synthesized in highly specialized endothelial cells that line the vasculature of the brain and central nervous system (CNS). These highly specialized cells, the major cell type lining the human CNS vasculature, are known as human brain microvessel endothelial cells (hBMECs). In the current pilot study we examined (i) CRP levels in human serum obtained from AD and age-matched control patients; and (ii) analyzed the effects of nanomolar aluminum sulfate on CRP expression in primary hBMECs. The three major findings in this short communication are: (i) that CRP is up-regulated in AD serum; (ii) that CRP serum levels increased in parallel with AD progression; and (iii) for the first time show that nanomolar aluminum potently up-regulates CRP expression in hBMECs to many times its 'basal abundance'. The results suggest that aluminum-induced CRP may in part contribute to a pathophysiological state associated with a chronic systemic inflammation of the human vasculature.

  4. Ion-induced Processing of Cosmic Silicates: A Possible Formation Pathway to GEMS

    Science.gov (United States)

    Jäger, C.; Sabri, T.; Wendler, E.; Henning, Th.

    2016-11-01

    Ion-induced processing of dust grains in the interstellar medium and in protoplanetary and planetary disks plays an important role in the entire dust cycle. We have studied the ion-induced processing of amorphous MgFeSiO4 and Mg2SiO4 grains by 10 and 20 keV protons and 90 keV Ar+ ions. The Ar+ ions were used to compare the significance of the light protons with that of heavier, but chemically inert projectiles. The bombardment was performed in a two-beam irradiation chamber for in situ ion-implantation at temperatures of 15 and 300 K and Rutherford Backscattering Spectroscopy to monitor the alteration of the silicate composition under ion irradiation. A depletion of oxygen from the silicate structure by selective sputtering of oxygen from the surface of the grains was observed in both samples. The silicate particles kept their amorphous structure, but the loss of oxygen caused the reduction of ferrous (Fe2+) ions and the formation of iron inclusions in the MgFeSiO4 grains. A few Si inclusions were produced in the iron-free magnesium silicate sample pointing to a much less efficient reduction of Si4+ and formation of metallic Si inclusions. Consequently, ion-induced processing of magnesium-iron silicates can produce grains that are very similar to the glassy grains with embedded metals and sulfides frequently observed in interplanetary dust particles and meteorites. The metallic iron inclusions are strong absorbers in the NIR range and therefore a ubiquitous requirement to increase the temperature of silicate dust grains in IR-dominated astrophysical environments such as circumstellar shells or protoplanetary disks.

  5. Ion irradiation induced effects and magnetization reversal mechanism in (Ni{sub 80}Fe{sub 20}){sub 1−x}Co{sub x} nanowires and nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Naeem, E-mail: naeem.ahmad@iiu.edu.pk [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing 100090 (China); Spintronics Laboratory, Department of Physics, Faculty of Basic and Applied Sciences (FBAS), International Islamic University H-10, Islamabad 44000 (Pakistan); Iqbal, Javed [Laboratory of Nanoscience and Technology, Department of Physics, International Islamic University, H-10, Islamabad,Pakistan (Pakistan); Chen, J.Y. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing 100090 (China); Hussain, Asim [Spintronics Laboratory, Department of Physics, Faculty of Basic and Applied Sciences (FBAS), International Islamic University H-10, Islamabad 44000 (Pakistan); Shi, D.W.; Han, X.F. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing 100090 (China)

    2015-03-15

    The effect of Co on the ferromagnetic characteristics of the Ni{sub 80}Fe{sub 20} nanocylinders having zero magnetostriction and soft magnetic nature is an interesting field of research. The (Ni{sub 80}Fe{sub 20}){sub 1−x}Co{sub x} nanocylinders have been prepared by electrodeposition into commercially available anodized aluminum oxide (AAO) nanoporous templates. The analysis of magnetization reversal from the angular dependence of coercivity has been studied in detail. This angular dependence of coercivity has shown a transition from curling to nucleation mode as a function of field angle for all (Ni{sub 80}Fe{sub 20}){sub 1−x}Co{sub x} nanocylinders depending upon the critical angle. The shape anisotropy, dipole–dipole interactions, surface effects and magnetocrystalline anisotropy have been found to play an effective role for the spontaneous magnetization in nanowires and nanotubes. It has been interestingly observed that the magnetostatic interactions or dipole–dipole interactions are dominant in nanocylinders regardless of its geometry. Furthermore, the prepared samples have been irradiated with He{sup 2+} ions (energy E=2 MeV, fluence=10{sup 14} ions/cm{sup 2} and ion current=16 nA) at room temperature using a 5-UDH-2pelletron tandem accelerator. The irradiations have created defects and these defects have induced changes in magnetization as a result an increase in coercivity as function of the ion fluences is observed. Such kind of behavior in coercivity enhancement and magnetization reduction can also be attributed to the stress relaxation and percolation in nonuniform states of ferromagnetic alloys, respectively. - Highlights: • We have prepared the ferromagnetic NiFeCo nanowires and nanotubes into anodized aluminum oxide templates (AAO) by electrodeposition method. • We have studied the magnetization reversal mechanism from the angle dependent coercivity measured by a hysteresis loop. • The ion irradiation effects on these nanostructures

  6. Low-energy plasma immersion ion implantation to induce DNA transfer into bacterial E. coli

    Energy Technology Data Exchange (ETDEWEB)

    Sangwijit, K. [Biotechnology Unit, University of Phayao, Muang, Phayao 56000 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [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); Sarapirom, S. [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, Bang Khen, Chiang Mai 50290 (Thailand); Pitakrattananukool, S. [School of Science, University of Phayao, Muang, Phayao 56000 (Thailand); Anuntalabhochai, S. [Biotechnology Unit, University of Phayao, Muang, Phayao 56000 (Thailand)

    2015-12-15

    Plasma immersion ion implantation (PIII) at low energy was for the first time applied as a novel biotechnology to induce DNA transfer into bacterial cells. Argon or nitrogen PIII at low bias voltages of 2.5, 5 and 10 kV and fluences ranging from 1 × 10{sup 12} to 1 × 10{sup 17} ions/cm{sup 2} treated cells of Escherichia coli (E. coli). Subsequently, DNA transfer was operated by mixing the PIII-treated cells with DNA. Successes in PIII-induced DNA transfer were demonstrated by marker gene expressions. The induction of DNA transfer was ion-energy, fluence and DNA-size dependent. The DNA transferred in the cells was confirmed functioning. Mechanisms of the PIII-induced DNA transfer were investigated and discussed in terms of the E. coli cell envelope anatomy. Compared with conventional ion-beam-induced DNA transfer, PIII-induced DNA transfer was simpler with lower cost but higher efficiency.

  7. Light-Induced Ion Rectification in Zigzag Nanochannels.

    Science.gov (United States)

    Li, Chuanshuai; Hu, Shimin; Yang, Lei; Fan, Jiajie; Yao, Zhiqiang; Zhang, Yiqiang; Shao, Guosheng; Hu, Junhua

    2015-12-01

    Ion transport through nanoporous systems has attracted broad interest due to its crucial role in physiological processes in living organisms and artificial bionic devices. In this work, a nanochannel system with a zigzag inner surface was fabricated by using a two-step anodizing technique. The rectification performance of the zigzag channels was observed by I-V measurement in KCl solution. Unlike channels with asymmetric geometry, the mechanism was analyzed based on the "point effect" of charge distribution and "shape effect" of the zigzag channel. The current rectification ratio decreases from nearly 3.0 to 1.0 when the KCl concentration increased from 0.1 mM to 100 mM. The fabrication of different nanopore systems and exploration of novel mechanisms will help to develop biomimetic membranes for practical applications.

  8. Stabilization of polymer gels against divalent ion-induced syneresis

    Energy Technology Data Exchange (ETDEWEB)

    Albonico, Paola; Lockhart, Thomas P. [Eniricerche SpA, San Donato, Milan (Italy)

    1997-07-15

    Polymer solutions and polymer gels are unstable to extended ageing in divalent cation-rich brines at elevated temperature. This paper shows that low-molecular-weight compounds that complex strongly with Ca{sup 2+} and Mg{sup 2+} are capable of neutralizing their destabilizing influence on polymer solubility and of inhibiting the syneresis of crosslinked acrylamide polymer gels in hard brines. The solubility of the inhibitor-divalent ion complexes formed in hard brine at elevated temperature have also been examined. The results obtained offer the possibility to extend significantly the upper temperature limit for the use of polyacrylamides and acrylamide copolymers in brines in both polymer flooding and polymer gel treatments

  9. Helium ion beam induced growth of hammerhead AFM probes

    NARCIS (Netherlands)

    Nanda, G.; Veldhoven, E. van; Maas, D.J.; Sadeghian Marnani, H.; Alkemade, P.F.A.

    2015-01-01

    The authors report the direct-write growth of hammerhead atomic force microscope (AFM) probes by He+ beam induced deposition of platinum-carbon. In order to grow a thin nanoneedle on top of a conventional AFM probe, the authors move a focused He+ beam during exposure to a PtC precursor gas. In the f

  10. Resonance activation and collision-induced-dissociation of ions using rectangular wave dipolar potentials in a digital ion trap mass spectrometer.

    Science.gov (United States)

    Xu, Fuxing; Wang, Liang; Dai, Xinhua; Fang, Xiang; Ding, Chuan-Fan

    2014-04-01

    Collision-induced dissociation (CID) of ions by resonance activation in a quadrupole ion trap is usually accomplished by resonance exciting the ions to higher kinetic energy, whereby the high kinetic energy ions collide with a bath gas, such as helium or argon, inside the trap and dissociate to fragments. A new ion activation method using a well-defined rectangular wave dipolar potential formed by dividing down the trapping rectangular waveform is developed and examined herein. The mass-selected parent ions are resonance excited to high kinetic energies by simply changing the frequency of the rectangular wave dipolar potential and dissociation proceeds. A relationship between the ion mass and the activation waveform frequency is also identified and described. This highly efficient (CID) procedure can be realized by simply changing the waveform frequency of the dipolar potential, which could certainly simplify tandem mass spectrometry analysis methods.

  11. How Hot are Your Ions Really? A Threshold Collision-Induced Dissociation Study of Substituted Benzylpyridinium "Thermometer" Ions

    Science.gov (United States)

    Carpenter, John E.; McNary, Christopher P.; Furin, April; Sweeney, Andrew F.; Armentrout, P. B.

    2017-05-01

    The first absolute experimental bond dissociation energies (BDEs) for the main heterolytic bond cleavages of four benzylpyridinium "thermometer" ions are measured using threshold collision-induced dissociation in a guided ion beam tandem mass spectrometer. In this experiment, substituted benzylpyridinium ions are introduced into the apparatus using an electrospray ionization source, thermalized, and collided with Xe at varied kinetic energies to determine absolute cross-sections for these reactions. Various effects are accounted for, including kinetic shifts, multiple collisions, and internal and kinetic energy distributions. These experimentally measured 0 K BDEs are compared with computationally predicted values at the B3LYP-GD3BJ, M06-GD3, and MP2(full) levels of theory with a 6-311+G(2d,2p) basis set using vibrational frequencies and geometries determined at the B3LYP/6-311+G(d,p) level. Additional dissociation pathways are observed for nitrobenzylpyridinium experimentally and investigated using these same levels of theory. Experimental BDEs are also compared against values in the literature at the AM1, HF, B3LYP, B3P86, and CCSD(T) levels of theory. Of the calculated values obtained in this work, the MP2(full) level of theory with counterpoise corrections best reproduces the experimental results, as do the similar literature CCSD(T) values. Lastly, the survival yield method is used to determine the characteristic temperature (Tchar) of the electrospray source prior to the thermalization region and to confirm efficient thermalization.

  12. Doping effects induced by potassium ion implantation in solid C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Trouillas, P. [Faculte des Sci., Limoges (France). Lab. d`Electronique des Polymers sous Faisceau Ionique; Moliton, A. [Faculte des Sci., Limoges (France). Lab. d`Electronique des Polymers sous Faisceau Ionique; Ratier, B. [Faculte des Sci., Limoges (France). Lab. d`Electronique des Polymers sous Faisceau Ionique

    1995-08-01

    Ion implantation is presented here as another technique for investigating the electrical properties of doped solid C{sub 60}. The conductivity and the thermopower have been studied versus the implantation parameters in order to investigate electrical transport phenomena which occur in implanted solid C{sub 60}, and thus prove doping effects. First results on ion implantation in C{sub 60} show a strong competition between damaging (induced by energetic ions) and doping effect (induced by charge transfer). Generally, electron transfers between the potassium atoms and the C{sub 60} molecules produce a conducting phase: up to x{approx} =0.1, metallic K{sub 3}C{sub 60} islands are dispersed in an insulating phase (virgin C{sub 60}); then, for x>0.1, damage plays a major role, leading to conduction paths through the samples (the saturation threshold x{approx} =0.1 is lower than in chemical doping due to the degradations). Potassium ion implantation with low energy (E{approx} =30 keV) and low fluence (D<10{sup 15} ions/cm{sup 2}) seems to provide the best implantation parameters for doping. Indeed, small ion size, low energy and low fluence are necessary in order to diminish the degradation effects. (orig.)

  13. Ion-induced ionization and capture cross sections for DNA nucleobases impacted by light ions

    Science.gov (United States)

    Champion, Christophe; Galassi, Mariel E.; Weck, Philippe F.; Fojón, Omar; Hanssen, Jocelyn; Rivarola, Roberto D.

    2012-11-01

    Two quantum mechanical models (CB1 and CDW-EIS) are here presented for describing electron ionization and electron capture induced by heavy charged particles in DNA bases. Multiple differential and total cross sections are determined and compared with the scarce existing experimental data.

  14. The Effect of Applied Stress on Environment-Induced Cracking of Aluminum Alloy 5052-H3 in 0.5 M NaCl Solution

    Directory of Open Access Journals (Sweden)

    Osama M. Alyousif

    2012-01-01

    Full Text Available The environment-induced cracking (EIC of aluminum alloy 5052-H3 was investigated as a function of applied stress and orientation (Longitudinal rolling direction—Transverse: LT and Transverse—Longitudinal rolling direction: TL in 0.5 M sodium chloride solution (NaCl using a constant load method. The applied stress dependence of the three parameters (time to failure; tf, steady-state elongation rate, Iss, and transition time at which a linear increase in elongation starts to deviate, tss obtained from the corrosion elongation curve showed that these relationships were divided into three regions, the stress-dominated region, the EIC- dominated region, and the corrosion-dominated region. Aluminum alloy 5052-H3 with both orientations showed the same EIC behavior. The value of tss/tf in the EIC-dominated region was almost constant with 0.57±0.02 independent of applied stress and orientation. The fracture mode was transgranular for 5052-H3 with both orientations in the EIC-dominated region. The relationships between log Iss and log tf for 5052-H3 in the EIC-dominated region became a good straight line with a slope of −2 independent of orientation.

  15. EC-18, a synthetic monoacetyldiglyceride (1-palmitoyl-2-linoleoyl-3-acetylglycerol), attenuates the asthmatic response in an aluminum hydroxide/ovalbumin-induced model of asthma.

    Science.gov (United States)

    Shin, In-Sik; Shin, Na-Rae; Jeon, Chan-Mi; Kwon, Ok-Kyoung; Sohn, Ki-Young; Lee, Tae-Suk; Kim, Jae-Wha; Ahn, Kyung-Seop; Oh, Sei-Ryang

    2014-01-01

    EC-18 is a synthetic monoacetyldiaglyceride that is a major constituent in antlers of Sika deer (Cervus nippon Temmenick). In this study, we evaluated the protective effects of EC-18 on Th2-type cytokines, eosinophil infiltration, and other factors in an aluminum hydroxide/ovalbumin (OVA)-induced murine asthma model. Mice were sensitized on days 0 and 14 by intraperitoneal injection of OVA with aluminum hydroxide. On days 21, 22 and 23 after the initial sensitization, the mice received an airway challenge with OVA for 1h using an ultrasonic nebulizer. EC-18 was administered to mice by oral gavage at doses of 30mg/kg and 60mg/kg once daily from day 18 to 23. Methacholine responsiveness was measured 24h after the final OVA challenge, and the bronchoalveolar lavage fluid (BALF) was collected 48h after the final OVA challenge. EC-18 significantly reduced methacholine responsiveness, T helper type 2 (Th2) cytokines, eotaxin-1, immunoglobulin (Ig) E, IgG, and the number of inflammatory cells. In addition, EC-18-treated mice exhibited the reduction in the expression of inducible nitric oxide synthase (iNOS) in lung tissue. In the histological analysis using hematoxylin-eosin stain and periodic acid-Schiff stain, EC-18 attenuated the infiltration of inflammatory cells into the airway and reduced the level of mucus production. Our results showed that EC-18 effectively suppressed the asthmatic response induced by OVA challenge. These effects were considered to be associated with iNOS suppression. In conclusion, this study suggests that EC-18 may be a therapeutic agent for allergic asthma.

  16. Investigation of DNA Damage Induced by 7Li and 12C Ions

    Institute of Scientific and Technical Information of China (English)

    SUILi; ZHAOKui; NIMei-nan; GUOJi-yu; LUOHong-bing; MEIJun-ping; KONGFu-quan; LUXiu-qin; ZHOUPing

    2003-01-01

    Deoxyribonucleic acid(DNA) is an important biomacromolecule. It is a carrier of genetic information and a critical target for radiobiological effects. Numerous lesions have been identified in irradiated DNA.DNA double strand breaks (DSBs) are considered as the most important initial damage of all biological effects induced by ionizing radiation. The goal of this experiment is to investigate DNA DSBs induced by heavy ions with atomic force microscopy (AFM).

  17. Effect of divalent ions in acrosome reaction induced by glycosamineglycans in porcine spermatozoa.

    Science.gov (United States)

    Delgado, N M; Carranco, A; Merchant, H; Reyes, R

    1985-01-01

    Magnesium, calcium, and zinc at the concentration of 10 microM are capable of inducing a "true" acrosome reaction in the pig spermatozoa judged by the criteria of the fusion of the acrosome and the plasmatic membrane at the anterior region or the sperm nucleus. The optimal percent of acrosome reaction reached by any of the ions tested as a whole was 50%. When glycosamineglycan sulfate (GAGs) plus 10 microM of Mg++, Ca++, or Zn++ was added, they reach to 70-80% of acrosome reaction. At the electrom microscope, thin sections taken from pig spermatozoa treated with ions, GAGs, or ion + GAGs under optimal experimental conditions revealed the same pattern of acrosomal reaction. Results suggest the important role that divalent cations play in general in the induction of the acrosome reaction and question the so-called essential role of calcium ions.

  18. Swift Heavy Ion Beam-induced Recrystallisation of Buried Silicon Nitride Layer (Review Paper

    Directory of Open Access Journals (Sweden)

    T. Som

    2009-07-01

    Full Text Available Studies on MeV heavy ion beam-induced epitaxial crystallisation of a buried silicon nitride layer are reported. Transmission electron micrographs and selected area diffraction patterns have been used to study the recrystallisation of an ion beam-synthesised layer. Complete recrystallisation of the silicon nitride layer having good quality interfaces with the top- and the substrate-Si has been obsorved. Recrystallisation is achieved at significantly lower temperatures of 100 and 200OC for oxygen and silver ions, respectively. The fact that recrystallisation is achieved at the lowest temperature for the oxygen ions is discussed on the basis of energy loss processes.Defence Science Journal, 2009, 59(4, pp.351-355, DOI:http://dx.doi.org/10.14429/dsj.59.1533

  19. Prooxidant and antioxidant effects of Trolox on ferric ion-induced oxidation of erythrocyte membrane lipids.

    Science.gov (United States)

    Ko, K M; Yick, P K; Poon, M K; Ip, S P

    1994-12-07

    The prooxidant and antioxidant actions of Trolox were examined in an in vitro system measuring ferric ion-induced oxidation of erythrocyte membrane lipids. Trolox was found to produce a concentration-dependent biphasic effect on the ferric ion-stimulated lipid peroxidation, with the mode of action being similar to those produced by reducing-agent antioxidants, such as ascorbic acid and reduced glutathione, and iron chelator, such as desferrioxamine. Phytic acid, a potent iron chelator, could suppress the prooxidant actions of Trolox and desferrioxamine, but not those of ascorbic acid and reduced glutathione. The ability of Trolox to stimulate ferric ion-catalyzed ascorbate oxidation, as similar to the action produced by ethylenediaminetetraacetic acid, indicates the presence of iron-chelating activity. The ensemble of results suggests the possible involvement of iron chelation in the prooxidant action of Trolox in ferric ion-stimulated lipid peroxidation reactions.

  20. Rotating Magnetohydrodynamic and Trapped Hot-Ion Induced Internal Kinks.

    Science.gov (United States)

    Varadarajan, V.

    1993-01-01

    As a new and significant contribution to the tokamak literature, the linear internal MHD kink modes in finite aspect-ratio axisymmetric toroidally rotating tokamak equilibria and their kinetic modifications owing to the presence of hot ions are computationally studied herein using a bilinear form derived using a Lagrangian perturbation procedure. As a practical application, the rotating MHD and kinetic internal kinks are calculated in finite aspect-ratio TFTR- and ITER -like geometries. The MHD and kinetic modes of the rotating tokamak plasmas are found to be significantly destabilized by the centrifugal effects at rotation speeds in the range of 10^4-10^5 rad/s at normal discharge densities. The kinetic instability model provides a unified description of several features of the 'fishbone'-like oscillations such as the slow mode rotating at the plasma rotation frequency, the fast mode with high rotation frequency, and variation of the slow as well as fast mode frequencies with plasma rotation. The slow kinetic modes rotate close to mean plasma rotation speeds, and the fast kinetic modes rotate at about 10 ^5 rad/s. The fast mode rotation frequencies are in the range of the magnetic-precession frequencies of the deeply trapped ions. Also, the kinetic kink modes are found to be excitable in ITER-like ignited tokamak configurations owing to hot fusion products such as alphas. Also, a feasibility study of adaptive distributed parameter control of thermokinetics is demonstrated. Fast transport simulation and control are explored using a nonlinear Galerkin procedure, and a MIMO self-tuning control algorithm. It is found that only the density control can achieve reasonable power set-point follow-up, and that more popular control schemes such as auxiliary power control are not adequate to provide real-world power swings greater than 50-100 MW around the set point. The several computational modules developed for this thesis are as follows. The equilibrium calculations are

  1. Phenomenological understanding of dewetting and embedding of noble metal nanoparticles in thin films induced by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Jai, E-mail: jai.gupta1983@gmail.com [Department of Chemistry, MMH College (Ch. Charan Singh University Meerut), Ghaiziabad 201001 (India); Chemical Physics of Materials, Université Libre de Bruxelles, Campus de la Plaine, CP 243, B-1050 Bruxelles (Belgium); Tripathi, A. [Inter University Accelerator Centre, Aruna Asif Ali Marg, New Delhi 110067 (India); Gautam, Sanjeev; Chae, K.H.; Song, Jonghan [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136–791 (Korea, Republic of); Rigato, V. [INFN Laboratori Nazionali di Legnaro, Via Romea. 4, 35020 Legnaro, Padova (Italy); Tripathi, Jalaj [Department of Chemistry, MMH College (Ch. Charan Singh University Meerut), Ghaiziabad 201001 (India); Asokan, K. [Inter University Accelerator Centre, Aruna Asif Ali Marg, New Delhi 110067 (India)

    2014-10-15

    The present experimental work provides the phenomenological approach to understand the dewetting in thin noble metal films with subsequent formation of nanoparticles (NPs) and embedding of NPs induced by ion irradiation. Au/polyethyleneterepthlate (PET) bilayers were irradiated with 150 keV Ar ions at varying fluences and were studied using scanning electron microscopy (SEM) and cross-sectional transmission electron microscopy (X-TEM). Thin Au film begins to dewet from the substrate after irradiation and subsequent irradiation results in spherical nanoparticles on the surface that at a fluence of 5 × 10{sup 16} ions/cm{sup 2} become embedded into the substrate. In addition to dewetting in thin films, synthesis and embedding of metal NPs by ion irradiation, the present article explores fundamental thermodynamic principles that govern these events systematically under the effect of irradiation. The results are explained on the basis of ion induced sputtering, thermal spike inducing local melting and of thermodynamic driving forces by minimization of the system free energy where contributions of surface and interfacial energies are considered with subsequent ion induced viscous flow in substrate. - Highlights: • Phenomenological interpretation of dewetting and embedding of metal NPs in thin film. • Exploring fundamental thermodynamic principles under influence of ion irradiation. • Ion induced surface/interface microstructural changes using SEM/X-TEM. • Ion induced sputtering, thermal spike induced local melting. • Thermodynamic driving forces relate to surface and interfacial energies.

  2. Suppression of ion-implantation induced porosity in germanium by a silicon dioxide capping layer

    Science.gov (United States)

    Tran, Tuan T.; Alkhaldi, Huda S.; Gandhi, Hemi H.; Pastor, David; Huston, Larissa Q.; Wong-Leung, Jennifer; Aziz, Michael J.; Williams, J. S.

    2016-08-01

    Ion implantation with high ion fluences is indispensable for successful use of germanium (Ge) in the next generation of electronic and photonic devices. However, Ge readily becomes porous after a moderate fluence implant ( ˜1 ×1015 ion cm-2 ) at room temperature, and for heavy ion species such as tin (Sn), holding the target at liquid nitrogen (LN2) temperature suppresses porosity formation only up to a fluence of 2 ×1016 ion cm-2 . We show, using stylus profilometry and electron microscopy, that a nanometer scale capping layer of silicon dioxide significantly suppresses the development of the porous structure in Ge during a S n - implant at a fluence of 4.5 ×1016 ion cm-2 at LN2 temperature. The significant loss of the implanted species through sputtering is also suppressed. The effectiveness of the capping layer in preventing porosity, as well as suppressing sputter removal of Ge, permits the attainment of an implanted Sn concentration in Ge of ˜15 at.% , which is about 2.5 times the maximum value previously attained. The crystallinity of the Ge-Sn layer following pulsed-laser-melting induced solidification is also greatly improved compared with that of uncapped material, thus opening up potential applications of the Ge-Sn alloy as a direct bandgap material fabricated by an ion beam synthesis technique.

  3. Review of Heavy-ion Induced Desorption Studies for Particle Accelerators

    CERN Document Server

    Mahner, E

    2008-01-01

    During high-intensity heavy-ion operation of several particle accelerators worldwide, large dynamic pressure rises of orders of magnitude were caused by lost beam ions that impacted under grazing angle onto the vacuum chamber walls. This ion-induced desorption, observed, for example, at CERN, GSI, and BNL, can seriously limit the ion intensity, luminosity, and beam lifetime of the accelerator. For the heavyion program at CERN's Large Hadron Collider collisions between beams of fully stripped lead (208Pb82+) ions with a beam energy of 2.76 TeV/u and a nominal luminosity of 10**27 cm**-2 s**-1 are foreseen. The GSI future project FAIR (Facility for Antiproton and Ion Research) aims at a beam intensity of 10**12 uranium (238U28+) ions per second to be extracted from the synchrotron SIS18. Over the past years an experimental effort has been made to study the observed dynamic vacuum degradations, which are important to understand and overcome for present and future particle accelerators. The paper reviews the resu...

  4. Heavy-ion induced modification of lithium fluoride observed by scanning force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, A.; Neumann, R.; Schwartz, K.; Steckenreiter, T.; Trautmann, C.

    1997-12-01

    To study ion-induced damages in single crystals of lithium fluoride with scanning force microscopy (SFM), samples were irradiated with several heavy-ion species of a kinetic energy of 11.4 MeV per nucleon at the linear accelerator UNILAC of GSI. As concluded from a previous analysis of ion tracks in LiF by optical absorption spectroscopy and small-angle X-ray scattering, single point defects occur in a track halo with a radius of about 15-30 nm, whereas defect aggregates are formed in a track core region possessing a radius of only about 1-2 nm. These aggregates can be attacked by chemical etching if the energy loss along the ion trajectory surpasses a critical value of about 1 keV/Aa. SFM images of etched as well as unetched sample surfaces revealed new damage characteristics: Etched ion track profiles directed parallel to the ion trajectories exhibit a sequence of single etch pits with an average distance of about 140 nm. After exposure to heavy-ion irradiation at normal incidence, the unetched LiF surface is covered with round hillocks with a mean diameter of 55(8) nm and heights in the order of 3 nm. (orig.)

  5. Spontaneous Ion Depletion and Accumulation Phenomena Induced by Imbibition through Permselective Medium

    Science.gov (United States)

    Lee, Hyomin; Jung, Yeonsu; Park, Sungmin; Kim, Ho-Young; Kim, Sung Jae

    2016-11-01

    Generally, an ion depletion region near a permselective medium is induced by predominant ion flux through the medium. External electric field or hydraulic pressure has been reported as the driving forces. Among these driving forces, an imbibition through the nanoporous medium was chosen as the mechanism to spontaneously generate the ion depletion region. The water-absorbing process leads to the predominant ion flux so that the spontaneous formation of the ion depletion zone is expected even if there are no additional driving forces except for the inherent capillary action. In this presentation, we derived the analytical solutions using perturbation method and asymptotic analysis for the spontaneous phenomenon. Using the analysis, we found that there is also spontaneous accumulation regime depending on the mobility of dissolved electrolytic species. Therefore, the rigorous analysis of the spontaneous ion depletion and accumulation phenomena would provide a key perspective for the control of ion transportation in nanofluidic system such as desalinator, preconcentrator, and energy harvesting device, etc. Samsung Research Funding Center of Samsung Electronics (SRFC-MA1301-02) and BK21 plus program of Creative Research Engineer Development IT, Seoul National University.

  6. Pressure-gradient-induced Alfven eigenmodes: 2. Kinetic excitation with ion temperature gradient

    CERN Document Server

    Bierwage, Andreas; Zonca, Fulvio

    2009-01-01

    The kinetic excitation of ideal magnetohydrodynamic (MHD) discrete Alfven eigenmodes in the second MHD ballooning stable domain is studied in the presence of a thermal ion temperature gradient (ITG), using linear gyrokinetic particle-in-cell simulations of a local flux tube in shifted-circle tokamak geometry. The instabilities are identified as alpha-induced toroidal Alfven eigenmodes (alphaTAE); that is, bound states trapped between pressure-gradient-induced potential barriers of the Schroedinger equation for shear Alfven waves. Using numerical tools, we examine in detail the effect of kinetic thermal ion compression on alphaTAEs; both non-resonant coupling to ion sound waves and wave-particle resonances. It is shown that the Alfvenic ITG instability thresholds (e.g., the critical temperature gradient) are determined by two resonant absorption mechanisms: Landau damping and continuum damping. The numerical results are interpreted on the basis of a theoretical framework previously derived from a variational f...

  7. Pulsed laser irradiation-induced microstructures in the Mn ion implanted Si

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Muneyuki, E-mail: naito22@center.konan-u.ac.jp [Department of Chemistry, Konan University, Okamoto, Higashi-Nada, Kobe, Hyogo 658-8501 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Yamada, Ryo; Machida, Nobuya [Department of Chemistry, Konan University, Okamoto, Higashi-Nada, Kobe, Hyogo 658-8501 (Japan); Koshiba, Yusuke; Sugimura, Akira; Aoki, Tamao; Umezu, Ikurou [Department of Physics, Konan University, Okamoto, Higashi-Nada, Kobe, Hyogo 658-8501 (Japan)

    2015-12-15

    We have examined microstructures induced by pulsed-laser-melting for the Mn ion implanted Si using transmission electron microscopy. Single crystalline Si(0 0 1) wafers were irradiated with 65 keV and 120 keV Mn ions to a fluence of 1.0 × 10{sup 16}/cm{sup 2} at room temperature. The ion beam-induced amorphous layers in the as-implanted samples were melted and resolidified by pulsed YAG laser irradiation. After laser irradiation with appropriate laser fluence, the surface amorphous layers recrystallize into the single crystalline Si. The Mn concentration becomes higher in the near-surface region with increasing the number of laser shots. The migrated Mn atoms react with Si atoms and form the amorphous Mn–Si in the Si matrix.

  8. Equivalence of displacement radiation damage in superluminescent diodes induced by protons and heavy ions

    Science.gov (United States)

    Li, Xingji; Liu, Chaoming; Lan, Mujie; Xiao, Liyi; Liu, Jianchun; Ding, Dongfa; Yang, Dezhuang; He, Shiyu

    2013-07-01

    The degradation of optical power for superluminescent diodes is in situ measured under exposures of protons with various energies (170 keV, 3 MeV and 5 MeV), and 25 MeV carbon ions for several irradiation fluences. Experimental results show that the optical power of the SLDs decreases with increasing fluence. The protons with lower energies cause more degradation in the optical power of SLDs than those with higher energies at a given fluence. Compared to the proton irradiation with various energies, the 25 MeV carbon ions induce more severe degradation to the optical power. To characterize the radiation damage of the SLDs, the displacement doses as a function of chip depth in the SLDs are calculated by SRIM code for the protons and carbon ions. Based on the irradiation testing and calculation results, an approach is given to normalize the equivalence of displacement damage induced by various charged particles in SLDs.

  9. Carbon ion induced DNA double-strand breaks in melanophore B{sub 16}

    Energy Technology Data Exchange (ETDEWEB)

    Wei Zengquan; Zhou Guangming; Wang Jufang; He Jing; Li Qiang; Li Wenjian; Xie Hongmei; Cai Xichen; Tao Huang; Dang Bingrong; Han Guangwu [Chinese Academy of Sciences, Lanzhou (China). Inst. of Modern Physics; Gao Qingxiang [Lanzhou Univ. (China)

    1997-09-01

    DNA double-strand breaks (DSBs) in melanophore B{sub 16} induced by plateau and extended Bragg peak of 75 MeV/u {sup 12}C{sup 6+} ions were studied by using a technique of inverse pulsed-field gel electrophoresis (PIGE). DNA fragment lengths were distributed in two ranges: the larger in 1.4 Mbp-3.2 Mbp and the smaller in less than 1.2 Mbp. It indicates that distribution of DNA fragments induced by heavy ion irradiation is not stochastic and there probably are sensitive sites to heavy ions in DNA molecules of B{sub 16}. Percentage of DNA released from plug (PR) increased and trended towards a quasi-plateau {proportional_to}85% as dose increased. Content of the larger fragments decreased and flattened with increasing dose while content of the smaller ones increased and trended towards saturation. (orig.)

  10. Role of substrate morphology in ion induced dewetting of thin solid films

    Energy Technology Data Exchange (ETDEWEB)

    Repetto, Luca, E-mail: luca.repetto@unige.it [Physics Department and Nanomed Labs, Università di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Lo Savio, Roberto [Physics Department and Nanomed Labs, Università di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Šetina Batič, Barbara [Inštitut Za Kovinske Materiale in Tehnologije, Lepi pot 11, 1000 Ljubljana (Slovenia); Firpo, Giuseppe; Valbusa, Ugo [Physics Department and Nanomed Labs, Università di Genova, Via Dodecaneso 33, 16146 Genova (Italy)

    2014-10-01

    Highlights: • We have created by ion bombardment silicon substrates with different topographies. • The substrates have been characterized by ellipsometry, AFM, SEM and EDX. • The substrates have been used for experiments of ion induced Cr films. • We show that different substrate topographies can induce different dewetted patterns. • Substrate topography can favor spinodal dewetting against heterogeneous nucleations. - Abstract: We investigate the role of the substrate morphology in the dewetting of ultrathin chromium films irradiated with 30 keV Ga ions. Silicon surfaces with different roughness were used as substrates for the films. The results of the irradiation experiments and of related simulations indicate that the chromium films can undergo a dewetting-like process through the two standard channels that show up for liquids, namely the spinodal channel, and the dewetting by heterogeneous nucleation. The two processes are competitive, and the prevailing one can be predicted and selected according to the characteristics of the substrate.

  11. Changes in the surface electronic states of semiconductor fine particles induced by high energy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yamaki, Tetsuya; Asai, Keisuke; Ishigure, Kenkichi [Tokyo Univ. (Japan); Shibata, Hiromi

    1997-03-01

    The changes in the surface electronic states of Q-sized semiconductor particles in Langmuir-Blodgett (LB) films, induced by high energy ion irradiation, were examined by observation of ion induced emission and photoluminescence (PL). Various emission bands attributed to different defect sites in the band gap were observed at the initial irradiation stage. As the dose increased, the emissions via the trapping sites decreased in intensity while the band-edge emission developed. This suggests that the ion irradiation would remove almost all the trapping sites in the band gap. The low energy emissions, which show a multiexponential decay, were due to a donor-acceptor recombination between the deeply trapped carriers. It was found that the processes of formation, reaction, and stabilization of the trapping sites would predominantly occur under the photooxidizing conditions. (author)

  12. Evidence for enhanced aluminum concentration in brain tissue from Alzheimer's disease patients using PIXE

    Science.gov (United States)

    Debray, M. E.; Kreiner, A. J.; Buhler, M.; Cardona, M. A.; Hojman, D.; Kesque, J. M.; Levinton, G.; Menéndez, J. J.; Naab, F.; Ozafrán, M. J.; Somacal, H.; Vázquez, M. E.; Grahmann, H.; Davidson, M.; Davidson, J.; Levin, M. E.; Mangone, C. A.; Caccuri, R. L.; Tokuda, A.; Eurnekian, A. A.; González, D.; López, C.; Roses, O. E.

    1997-02-01

    The Particle Induced X-Ray Emission (PIXE) analytical technique with 16O ion beams (18 MeV) was applied to the study of elemental composition at different brain regions of patients with a confirmed post-mortem diagnosis of Alzheimer's disease and in samples from control subjects. The results obtained in the actual study show a clear correlation between occurrence of Alzheimer's disease and the presence and increased concentration of aluminum (Al).

  13. Preface: Photon and fast Ion induced Processes in Atoms, MOlecules and Nanostructures (PIPAMON)

    Science.gov (United States)

    Kövér, László

    2016-02-01

    This Special Issue contains selected papers of contributions presented in the International Workshop on Photon and fast Ion induced Processes in Atoms, MOlecules and Nanostructures (PIPAMON), held between March 24 and 26, 2015 in Debrecen, Hungary. The venue, the Aquaticum Thermal and Wellness Hotel provided a pleasant "all-under-one-roof" environment for the event.

  14. Cavity electromagnetically induced transparency and all-optical switching using ion Coulomb crystals

    DEFF Research Database (Denmark)

    Albert, Magnus; Dantan, Aurelien Romain; Drewsen, Michael

    2011-01-01

    nonlinear interactions, such as those based on electromagnetic induced transparency (EIT)2, 3, 4, 5, 6, 9, 10, 11, 12. Here, we demonstrate for the first time EIT as well as all-optical EIT-based light switching using ion Coulomb crystals situated in an optical cavity. Changes from essentially full...

  15. Roles of secondary electrons and sputtered atoms in ion-beam-induced deposition

    NARCIS (Netherlands)

    Chen, P.; Salemink, H.W.M.; Alkemade, P.F.A.

    2009-01-01

    The authors report the results of investigating two models for ion-beam-induced deposition (IBID). These models describe IBID in terms of the impact of secondary electrons and of sputtered atoms, respectively. The yields of deposition, sputtering, and secondary electron emission, as well as the ener

  16. Three-dimensional Nanostructures Fabricated by Ion-Beam-Induced Deposition

    NARCIS (Netherlands)

    Chen, P.

    2010-01-01

    The direct writing technology known as ion-beam-induced deposition (IBID) has been attracting attention mainly because of its high degree of flexibility of locally prototyping three-dimensional (3D) nanostructures. These high-resolution nanostructures have various research applications. However, no

  17. Analyses on Radiation Effects in Solid Amino Acids Induced by Low Energy Fe~+ Ion Beams

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Radiation effects in Solid samples of L(+)-cysteine and L(+)-cysteine hydroehloride monohydrate induced by 110 keV Fe~+ion implantation were characterized with FTIR, ESR,HPLC and ESI-FTMS.It was validated that solid samples of the irradiated amino acids were damaged to a certain extent,and some new groups or molecular products formed.

  18. Ion effects in hydrogen-induced blistering of Mo/Si multilayers

    NARCIS (Netherlands)

    Kuznetsov, A. S.; Gleeson, M. A.; F. Bijkerk,

    2013-01-01

    The role that energetic (>800 eV) hydrogen ions play in inducing and modifying the formation of blisters in nanoscale Mo/Si multilayer samples is investigated. Such samples are confirmed to be susceptible to blistering by two separate mechanisms. The first is attributed to the segregation of

  19. Ion effects in hydrogen-induced blistering of Mo/Si multilayers

    NARCIS (Netherlands)

    Kuznetsov, A.; Gleeson, M.A.; Bijkerk, F.

    2013-01-01

    The role that energetic (>800 eV) hydrogen ions play in inducing and modifying the formation of blisters in nanoscale Mo/Si multilayer samples is investigated. Such samples are confirmed to be susceptible to blistering by two separate mechanisms. The first is attributed to the segregation of H atom

  20. Ion-Induced Fragmentation of Amino Acids : Effect of the Environment

    NARCIS (Netherlands)

    Maclot, Sylvain; Capron, Michael; Maisonny, Remi; Lawicki, Arkadiusz; Mery, Alain; Rangama, Jimmy; Chesnel, Jean-Yves; Bari, Sadia; Hoekstra, Ronnie; Schlatholter, Thomas; Manil, Bruno; Adoui, Lamri; Rousseau, Patrick; Huber, Bernd A.

    2011-01-01

    In general, radiation-induced fragmentation of small amino acids is governed by the cleavage of the C-C(alpha) bond. We present results obtained with 300 keV Xe(20+) ions that allow molecules (glycine and valine) to be ionised at large distances without appreciable energy transfer. Also in the prese

  1. Fast-ion transport induced by Alfvén eigenmodes in the ASDEX Upgrade tokamak

    DEFF Research Database (Denmark)

    Garcia-Munoz, M.; Classen, I.G.J.; Geiger, B.

    2011-01-01

    A comprehensive suite of diagnostics has allowed detailed measurements of the Alfvén eigenmode (AE) spatial structure and subsequent fast-ion transport in the ASDEX Upgrade (AUG) tokamak [1]. Reversed shear Alfvén eigenmodes (RSAEs) and toroidal induced Alfvén eigenmodes (TAEs) have been driven u...

  2. Fission fragment angular distribution in heavy-ion-induced fission with anomalous behavior

    Science.gov (United States)

    Soheyli, S.; Feizi, B.

    2014-08-01

    Fission fragment angular distribution in heavy-ion-induced fission reactions is of particular importance. Transition state theory is provided to determine the angular distribution of fission fragments which includes standard saddle-point statistical and standard scission-point statistical models. The standard saddle-point statistical model was not able to reproduce the experimental fission fragment angular anisotropies for several heavy-ion-induced fission systems. In contrast to the standard saddle-point model, the standard scission-point statistical model was fairly successful in the prediction of angular anisotropy in heavy-ion-induced fission reaction systems with an anomalous behavior in angular anisotropy of fission fragments, but this model is not widely used as the standard saddle-point statistical model. In this research, a generalized model is introduced for the prediction of fission fragments angular anisotropy in the heavy-ion-induced fission reaction systems having an anomalous behavior. For this purpose, we study the N14,O16,F19+Th232;O16,F19+U238;Mg24,Si28,S32+Pb208;S32+Au197; and O16+Cm248 reaction systems. Finally, it is shown that the presented model is much more successful than previous models.

  3. Observation of energetic-ion losses induced by various MHD instabilities in the Large Helical Device (LHD)

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, K. [Nagoya University, Japan; Isobe, M. [National Institute for Fusion Science, Toki, Japan; Toi, K. [National Institute for Fusion Science, Toki, Japan; Watanabe, F. [Kyoto University, Japan; Spong, Donald A [ORNL; Shimizu, A. [National Institute for Fusion Science, Toki, Japan; Osakabe, M. [National Institute for Fusion Science, Toki, Japan; Ohdachi, S. [National Institute for Fusion Science, Toki, Japan; Sakakibara, S. [National Institute for Fusion Science, Toki, Japan

    2010-01-01

    Energetic-ion losses induced by toroidicity-induced Alfven eigenmodes (TAEs) and resistive interchange modes (RICs) were observed in neutral-beam heated plasmas of the Large Helical Device (LHD) at a relatively low toroidal magnetic field level (<= 0.75 T). The energy and pitch angle of the lost ions are detected using a scintillator-based lost-fast ion probe. Each instability increases the lost ions having a certain energy/pitch angle. TAE bursts preferentially induce energetic beam ions in co-passing orbits having energy from the injection energy E = 190keV down to 130 keV, while RICs expel energetic ions of E = 190 keV down to similar to 130 keV in passing-toroidally trapped boundary orbits. Loss fluxes induced by these instabilities increase with different dependences on the magnetic fluctuation amplitude: nonlinear and linear dependences for TAEs and RICs, respectively.

  4. Ion induced changes in the structure of bordered pit membranes

    Directory of Open Access Journals (Sweden)

    Jinkee eLee

    2012-03-01

    Full Text Available Xylem hydraulic resistance varies with ion concentration in sap solution. It is assumed that this variation in resistance results from hydrogel like properties of pectins located in bordered pit membranes separating adjacent vessels. Although kinetics of the resistance change suggests swelling/deswelling behavior of the pectins, there is no direct evidence of this activity. In this report we provide evidence of structural changes in bordered pit membranes responding to variation in ionic concentration of solute around it using atomic force microscopy (AFM. AFM revealed bordered pit membranes as relatively smooth, soft and lacking any sharp edges surface when submerged in de-ionized water, in contrast to pictures from scanning electron microscope (SEM or AFM performed on air dry material. Exposure of the bordered pit membranes to 50 mM KCl solution resulted in significant changes in both surface physical properties with and elevation features as bordered pit membrane became harder, with visible edges of fibers and collapsed, while no change in porosity was observed. Analysis suggests a need for a major shift in our understanding to the physical bases of variable xylem resistance from change in porosity to change in pathway length. Findings support the role of actuating properties of hybrid hydrogel-cellulose materials in water redistribution and embolism resistance.

  5. Study on swift heavy ions induced modifications of Ag-ZnO nanocomposite thin film

    Science.gov (United States)

    Singh, S. K.; Singhal, R.; Siva Kumar, V. V.

    2017-03-01

    In the present work, swift heavy ion (SHI) irradiation induced modifications in structural and optical properties of Ag-ZnO nanocomposite thin films have been investigated. Ag-ZnO nanocomposite (NCs) thin films were synthesized by RF magnetron sputtering technique and irradiated with 100 MeV Ag7+ ions at three different fluences 3 × 1012, 1 × 1013 and 3 × 1013 ions/cm2. Rutherford Backscattering Spectrometry revealed Ag concentration to be ∼8.0 at.%, and measured thickness of the films was ∼55 nm. Structural properties of pristine and irradiated films have been analyzed by X-ray diffraction analysis and found that variation in crystallite size of the film with ion irradiation. X-ray photoelectron spectroscopy (XPS) indicates the formation of Ag-ZnO nanocomposite thin film with presence of Ag, Zn and O elements. Oxidation state of Ag and Zn also estimated by XPS analysis. Surface plasmon resonance (SPR) of Ag nanoparticle has appeared at ∼475 nm in the pristine thin film, which is blue shifted by ∼30 nm in film irradiated at fluence of 3 × 1012 ions/cm2 and completely disappeared in film irradiated at higher fluences, 1 × 1013 and 3 × 1013 ions/cm2. A marginal change in the optical band gap of Ag-ZnO nanocomposite thin film is also found with increasing ion fluence. Surface morphology of pristine and irradiated films have been studied using Atomic Force Microscopy (AFM). Raman and Photo-luminance (PL) spectra of nanocomposite thin films have been investigated to understand the ion induced modifications such as lattice defects and disordering in the nanocomposite thin film.

  6. Effect of hardening induced by cold expansion on damage fatigue accumulation and life assessment of Aluminum alloy 6082 T6

    Directory of Open Access Journals (Sweden)

    Bendouba Mostefa

    2012-12-01

    Full Text Available Hole cold expansion (HCE is an effective method to extend the fatigue life of mechanical structures. During cold expansion process compressive residual stresses around the expanded hole are generated. The enhancement of fatigue life and the crack initiation and growth behavior of a holed specimen were investigated by using the 6082 Aluminum alloy. The present study suggests a simple technical method for enhancement of fatigue life by a cold expansion hole of pre-cracked specimen. Fatigue damage accumulation of cold expanded hole in aluminum alloy which is widely used in transportation and in aeronautics was analyzed. Experimental tests were carried out using pre-cracked SENT specimens. Tests were performed in two and four block loading under constant amplitude. These tests were performed by using two and four blocks under uniaxial constant amplitude loading. The increasing and decreasing loading were carried. The experimental results were compared to the damage calculated by the Miner's rule and a new simple fatigue damage indicator. This comparison shows that the 'damaged stress model', which takes into account the loading history, yields a good estimation according to the experimental results. Moreover, the error is minimized in comparison to the Miner's model.

  7. Size-to-charge dispersion of collision-induced dissociation product ions for enhancement of structural information and product ion identification.

    Science.gov (United States)

    Zinnel, Nathanael F; Russell, David H

    2014-05-20

    Ion mobility is used to disperse product ions formed by collision-induced dissociation (CID) on the basis of charge state and size-to-charge ratio. We previously described an approach for combining CID with ion mobility mass spectrometry (IM-MS) for dispersing fragment ions along charge state specific trend lines (Zinnel, N. F.; Pai, P. J.; Russell, D. H. Anal. Chem. 2012, 84, 3390; Sowell, R. A.; Koeniger, S. L.; Valentine, S. J.; Moon, M. H.; Clemmer, D. E. J. Am. Soc. Mass Spectrom. 2004, 15, 1341; McLean, J. A.; Ruotolo, B. T.; Gillig, K. J.; Russell, D. H. Int. J. Mass Spectrom. 2005, 240, 301), and this approach was used to assign metal ion binding sites for human metallothionein protein MT-2a (Chen, S. H.; Russell, W. K.; Russell, D. H. Anal. Chem. 2013, 85, 3229). Here, we use this approach to distinguish b-type N-terminal fragment ions from both internal fragment ions and y-type C-terminal fragment ions. We also show that in some cases specific secondary structural elements, viz., extended coils or helices, can be obtained for the y-type fragment ions series. The advantage of this approach is that product ion identity can be correlated to gas-phase ion structure, which provides rapid identification of the onset and termination of extended coil structure in peptides.

  8. Aluminum recovery as a product with high added value using aluminum hazardous waste

    Energy Technology Data Exchange (ETDEWEB)

    David, E., E-mail: david@icsi.ro [National Institute for Research and Development for Cryogenic and Isotopic Technologies, Street Uzinei, No. 4, P.O. Râureni, P.O. Box 7, 240050 Rm. Vâlcea (Romania); Kopac, J. [Faculty of Mechanical Engineering, University of Ljubljana, Askerceva 6, SI-1000 Ljubljana (Slovenia)

    2013-10-15

    Highlights: • Granular and compact aluminum dross were physically and chemically characterized. • A relationship between density, porosity and metal content from dross was established. • Chemical reactions involving aluminum in landfill and negative consequences are shown. • A processing method for aluminum recovering from aluminum dross was developed. • Aluminum was recovered as an value product with high grade purity such as alumina. -- Abstract: The samples of hazardous aluminum solid waste such as dross were physically and chemically characterized. A relationship between density, porosity and metal content of dross was established. The paper also examines the chemical reactions involving aluminum dross in landfill and the negative consequences. To avoid environmental problems and to recovery the aluminum, a processing method was developed and aluminum was recovered as an added value product such as alumina. This method refers to a process at low temperature, in more stages: acid leaching, purification, precipitation and calcination. At the end of this process aluminum was extracted, first as Al{sup 3+} soluble ions and final as alumina product. The composition of the aluminum dross and alumina powder obtained were measured by applying the leaching tests, using atomic absorption spectrometry (AAS) and chemical analysis. The mineralogical composition of aluminum dross samples and alumina product were determined by X-ray diffraction (XRD) and the morphological characterization was performed by scanning electron microscopy (SEM). The method presented in this work allows the use of hazardous aluminum solid waste as raw material to recover an important fraction from soluble aluminum content as an added value product, alumina, with high grade purity (99.28%)

  9. Catalytic Behaviour of Mesoporous Cobalt-Aluminum Oxides for CO Oxidation

    Directory of Open Access Journals (Sweden)

    Ankur Bordoloi

    2014-01-01

    Full Text Available Ordered mesoporous materials are promising catalyst supports due to their uniform pore size distribution, high specific surface area and pore volume, tunable pore sizes, and long-range ordering of the pore packing. The evaporation-induced self-assembly (EISA process was applied to synthesize mesoporous mixed oxides, which consist of cobalt ions highly dispersed in an alumina matrix. The characterization of the mesoporous mixed cobalt-aluminum oxides with cobalt loadings in the range from 5 to 15 wt% and calcination temperatures of 673, 973, and 1073 K indicates that Co2+ is homogeneously distributed in the mesoporous alumina matrix. As a function of the Co loading, different phases are present comprising poorly crystalline alumina and mixed cobalt aluminum oxides of the spinel type. The mixed cobalt-aluminum oxides were applied as catalysts in CO oxidation and turned out to be highly active.

  10. Study of the degradation process of polyimide induced by high energetic ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Severin, Daniel

    2008-09-19

    The dissertation focuses on the radiation hardness of Kapton under extreme radiation environment conditions. To study ion-beam induced modifications, Kapton foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (e.g. Ti, Mo, Au, and U) within a large fluence regime (1 x 10{sup 10}-5 x 10{sup 12} ions/cm{sup 2}). The irradiated Kapton foils were analysed by means of infrared and UV/Vis spectroscopy, tensile strength measurement, mass loss analysis, and dielectric relaxation spectroscopy. For testing the radiation stability of Kapton at the cryogenic operation temperature (5-10 K) of the superconducting magnets, additional irradiation experiments were performed at the Grand Accelerateur National d' Ions Lourds (GANIL, France) focusing on the online analysis of the outgassing process of small volatile degradation fragments. The investigations of the electrical properties analysed by dielectric relaxation spectroscopy exhibit a different trend: high fluence irradiations with light ions (e.g. Ti) lead to a slight increase of the conductivity, whereas heavy ions (e.g. Sm, Au) cause a drastic change already in the fluence regime of nonoverlapping tracks (5 x 10{sup 10} ions/cm{sup 2}). Online analysis of the outgassing process during irradiation at cryogenic temperatures shows the release of a variety of small gaseous molecules (e.g. CO, CO{sub 2}, and short hydro carbons). Also a small amount of large polymer fragments is identified. The results allow the following conclusions which are of special interest for the application of Kapton as insulating material in a high-energetic particle radiation environment. a) The material degradation measured with the optical spectroscopy and tensile strength tests are scalable with the dose deposited by the ions. The high correlation of the results allows the prediction of the mechanical degradation with the simple and non-destructive infrared spectroscopy. The degradation curve points to a

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

    Directory of Open Access Journals (Sweden)

    E. Mahner

    2011-05-01

    Full Text Available 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 gold-coated copper, were bombarded under perpendicular impact with 4.2  MeV/u Pb^{54+} ions. Partial pressure rises of H_{2}, CH_{4}, CO, and CO_{2} 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.

  12. Ion-beam-induced modifications in the structural and electrical properties of copper oxide selenite nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Pallavi, E-mail: prana.phy@gmail.com; Chauhan, R.P.

    2015-04-15

    Highlights: •Nanowires were synthesized via template-assisted electrodeposition method. •Copper oxide selenite nanowires were irradiated with 160 MeV, Ni{sup +12} ion beam. •XRD confirmed no change in phase of irradiated nanowires. •Electrical resistivity of nanowires was found to decrease with the ion fluence. -- Abstract: Irradiation with swift heavy ions (SHIs) with energy in the MeV range is a unique tool for engineering the properties of materials. In this context, the objective of the present work is to study the conduction of charge carriers in pre- and post-ion-irradiated semiconducting nanowires. Copper oxide selenite nanowires were synthesized using a template-assisted electrodeposition technique from an aqueous solution of 0.8 M CuSO{sub 4}·5H{sub 2}O and 8 mM SeO{sub 2}. The synthesized nanowires were observed to have a monoclinic structure with linear I–V characteristics (IVC). The effect of irradiation with 160 MeV Ni{sup +12} ions on the properties of the copper oxide selenite nanowires was investigated for fluences varying from 10{sup 11} to 10{sup 13} ions/cm{sup 2}. XRD spectra confirmed no change in the phase of the swift-heavy-ion-irradiated nanowires, but a modification in the orientation of the planes was observed that depended on the ion fluence. The electrical resistivity of the semiconducting nanowires also varied with the ion fluence. Simultaneous irradiation-induced modifications to the electro-chemical potential gradient and the granular properties of the material may have been the origin of the alteration in the structural and electrical properties of the nanowires.

  13. Ion-beam induced structure modifications in amorphous germanium; Ionenstrahlinduzierte Strukturmodifikationen in amorphem Germanium

    Energy Technology Data Exchange (ETDEWEB)

    Steinbach, Tobias

    2012-05-03

    Object of the present thesis was the systematic study of ion-beam induced structure modifications in amorphous germanium (a-Ge) layers due to low- (LEI) and high-energetic (SHI) ion irradiation. The LEI irradiation of crystalline Ge (c-Ge) effects because the dominating nuclear scattering of the ions on the solid-state atoms the formation of a homogeneous a-Ge Layer. Directly on the surface for fluences of two orders of magnitude above the amorphization fluence the formation of stable cavities independently on the irradiation conditions was observed. For the first time for the ion-beam induced cavity formation respectively for the steady expansion of the porous layer forming with growing fluence a linear dependence on the energy {epsilon}{sub n} deposed in nuclear processes was detected. Furthermore the formation of buried cavities was observed, which shows a dependence on the type of ions. While in the c-Ge samples in the range of the high electronic energy deposition no radiation defects, cavities, or plastic deformations were observed, the high electronic energy transfer in the 3.1 {mu}m thick pre-amorphized a-Ge surface layers leads to the formation of randomly distributed cavities. Basing on the linear connection between cavity-induced vertical volume expansion and the fluence determined for different energy transfers for the first time a material-specific threshold value of {epsilon}{sub e}{sup HRF}=(10.5{+-}1.0) kev nm{sup -1} was determined, above which the ion-beam induced cavity formation in a-Ge sets on. The anisotropic plastic deformation of th a-Ge layer superposed at inclined SHI irradiation on the cavity formation was very well described by an equation derived from the viscoelastic Maxwell model, but modified under regardment of the experimental results. The positive deformation yields determined thereby exhibit above a threshold value for the ion-beam induced plastic deformation {epsilon}{sub e}{sup S{sub a}}=(12{+-}2) keV nm{sup -1} for the first

  14. Optical Transmittance of Anodically Oxidized Aluminum Alloy

    Science.gov (United States)

    Saito, Mitsunori; Shiga, Yasunori; Miyagi, Mitsunobu; Wada, Kenji; Ono, Sachiko

    1995-06-01

    Optical transmittance and anisotropy of anodic oxide films that were made from pure aluminum and an aluminum alloy (A5052) were studied. The alloy oxide film exhibits an enhanced polarization function, particularly when anodization is carried out at a large current density. It was revealed by chemical analysis that the alloy oxide film contains a larger amount of unoxidized aluminum than the pure-aluminum oxide film. The polarization function can be elucidated by considering unoxidized aluminum particles that are arranged in the columnar structure of the alumina film. Electron microscope observation showed that many holes exist in the alloy oxide film, around which columnar cells are arranged irregularly. Such holes and irregular cell arrangement cause the increase in the amount of unoxidized aluminum, and consequently induces scattering loss.

  15. Ion beam induced luminescence of germano-silicate optical fiber preform

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hyunkyu; Kim, Jongyeol; Lee, Namho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Youngwoong; Han, Wontaek [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Markovic, Nikola; Jaksic, Milko [Ruder Boskovic Institute, Zagred (Croatia)

    2014-05-15

    When an optical fiber is exposed to radiation, the attenuation (RIA, Radiation Induced Attenuation) in the optical fiber (OF) is increased because of the color centers which deteriorate the transmission property and generate the absorption loss. In order to understand the radiation induced defect, Ion Beam induced luminescence (IBIL) was introduced to investigate it. IBIL technique is to analyze IR/VIS/UV luminescence related to ion beam interaction with outer shell electrons involved in chemical bonds and structure defects of target atoms. So IBIL is sensitive to its chemical composition and has been used in analysis of material characterization, geological samples and cultural heritage objects. In silica material, four O atoms are surrounding one Si atom in tetrahedral coordination. In this study, the influence of Copper (Cu) and Cerium (Ce) dopants to germano silica core optical fibers were investigated under proton irradiation at RBI using Ion Beam induced luminescence (IBIL) method. To understand the radiation induced defect of optical fibers, IBIL were tested to a germano-silica core fiber under 2 MeV proton irradiation. Although a Cu or Ce dopant was not detected by IBIL technique, the relation between the amount of radiation and luminescence can be established. This experiment showed a potential technique of studying the effects and behavior of additive elements for silica core fiber. To increase the radiation resistance of optical fibers, further investigations are needed, i. e. the proper additives and its contents and an interaction mechanism between Ge-related defects and additives.

  16. Room Temperature Ion-Beam-Induced Recrystallization and Large Scale Nanopatterning.

    Science.gov (United States)

    Satpati, Biswarup; Ghosh, Tanmay

    2015-02-01

    We have studied ion-induced effects in the near-surface region of two eutectic systems. Gold and Silver nanodots on Silicon (100) substrate were prepared by thermal evaporation under high vacuum condition at room temperature (RT) and irradiated with 1.5 MeV Au2+ ions at flux ~1.25 x 10(11) ions cm-2 s-1 also at RT. These samples were characterized using cross-sectional transmission electron microscopy (XTEM) and associated techniques. We have observed that gold act as catalysis in the recrystallization process of ion-beam-induced amorphous Si at room temperature and also large mass transport up to a distance of about 60 nm into the substrate. Mass transport is much beyond the size (~ 6-20 nm) of these Au nanodots. Ag nanoparticles with diameter 15-45 nm are half-way embedded into the Si substrate and does not stimulate in recrystallization. In case of Au nanoparticles upon ion irradiation, mixed phase formed only when the local composition and transient temperature during irradiation is sufficient to cause mixing in accordance with the Au-Si stable phase diagram. Spectroscopic imaging in the scanning TEM using spatially resolved electron energy loss spectroscopy provides one of the few ways to measure the real-space nanoscale mixing.

  17. Difference of soft error rates in SOI SRAM induced by various high energy ion species

    Energy Technology Data Exchange (ETDEWEB)

    Abo, Satoshi, E-mail: abo@cqst.osaka-u.ac.jp [Center for Quantum Science and Technology Under Extreme Conditions, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Masuda, Naoyuki; Wakaya, Fujio; Lohner, Tivadar [Center for Quantum Science and Technology Under Extreme Conditions, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Onoda, Shinobu; Makino, Takahiro; Hirao, Toshio; Ohshima, Takeshi [Semiconductor Analysis and Radiation Effects Group, Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Iwamatsu, Toshiaki; Oda, Hidekazu [Advanced Device Technology Department, Production and Technology Unit, Devices and Analysis Technology Division, Renesas Electronics Corporation, 751, Horiguchi, Hitachinaka, Ibaraki 312-8504 (Japan); Takai, Mikio [Center for Quantum Science and Technology Under Extreme Conditions, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2012-02-15

    Soft error rates in silicon-on-insulator (SOI) static random access memories (SRAMs) with a technology node of 90 nm have been investigated by beryllium and carbon ion probes. The soft error rates induced by beryllium and carbon probes started to increase with probe energies of 5.0 and 8.5 MeV, in which probes slightly penetrated the over-layer, and were saturated with energies at and above 7.0 and 9.0 MeV, in which the generated charge in the SOI body was more than the critical charge. The soft error rates in the SOI SRAMs by various ion probes were also compared with the generated charge in the SOI body. The soft error rates induced by hydrogen and helium ion probes were 1-2 orders of magnitude lower than those by beryllium, carbon and oxygen ion probes. The soft error rates depend not only on the generated charge in the SOI body but also on the incident ion species.

  18. Subsurface Aluminum Nitride Formation in Iron-Aluminum Alloys

    Science.gov (United States)

    Bott, June H.

    Transformation-induced plasticity (TRIP) steels containing higher amounts of aluminum than conventional steels are ideal for structural automotive parts due to their mechanical properties. However, the aluminum tends to react with any processing environment at high temperatures and therefore presents significant challenges during manufacturing. One such challenge occurs during secondary cooling, reheating, and hot-rolling and is caused by a reaction with nitrogen-rich atmospheres wherein subsurface aluminum nitride forms in addition to internal and external oxides. The nitrides are detrimental to mechanical properties and cause surface cracks. It is important to understand how these nitrides and oxides form and their consequences for the quality of steel products. This study looks at model iron-aluminum (up to 8 wt.% aluminum) alloys and uses confocal laser scanning microscopy, x-ray diffraction, scanning electron microscopy with energy dispersive x-ray spectrometry, and transmission electron microscopy to study the effect of various conditions on the growth and development of these precipitates in a subsurface oxygen-depleted region. By using model alloys and controlling the experimental atmosphere, this study is able to understand some of the more fundamental materials science behind aluminum nitride formation in aluminum-rich iron alloys and the relationship between internal nitride and oxide precipitation and external oxide scale morphology and composition. The iron-aluminum alloys were heated in N2 atmospheres containing oxygen impurities. It was found that nitrides formed when bulk aluminum content was below 8 wt.% when oxygen was sufficiently depleted due to the internal oxidation. In the samples containing 1 wt.% aluminum, the depth of the internal oxide and nitride zones were in agreement with a diffusion-based model. Increasing aluminum content to 3 and 5 wt% had the effects of modifying the surface-oxide scale composition and increasing its continuity

  19. Long-term follow-up of cognitive dysfunction in patients with aluminum hydroxide-induced macrophagic myofasciitis (MMF).

    Science.gov (United States)

    Passeri, Elodie; Villa, Chiara; Couette, Maryline; Itti, Emmanuel; Brugieres, Pierre; Cesaro, Pierre; Gherardi, Romain K; Bachoud-Levi, Anne-Catherine; Authier, François-Jérôme

    2011-11-01

    Macrophagic myofasciitis (MMF) is characterized by specific muscle lesions assessing long-term persistence of aluminum hydroxide within macrophages at the site of previous immunization. Affected patients are middle-aged adults, mainly presenting with diffuse arthromyalgias, chronic fatigue, and cognitive dysfunction. Representative features of MMF-associated cognitive dysfunction (MACD) include (i) dysexecutive syndrome; (i) visual memory; (iii) left ear extinction at dichotic listening test. In present study we retrospectively evaluated the progression of MACD in 30 MMF patients. Most patients fulfilled criteria for non-amnestic/dysexecutive mild cognitive impairment, even if some cognitive deficits seemed unusually severe. MACD remained stable over time, although dysexecutive syndrome tended to worsen. Long-term follow-up of a subset of patients with 3 or 4 consecutive neuropsychological evaluations confirmed the stability of MACD with time, despite marked fluctuations.

  20. Segregation and evaporation behaviors of aluminum and calcium in silicon during solidification process induced by electron beam

    Science.gov (United States)

    Jiang, Dachuan; Shi, Shuang; Tan, Yi; Asghar, H. M. Noor ul Huda Khan; Qin, Shiqiang

    2015-03-01

    An experimental investigation into the removal of aluminum (Al) and calcium (Ca) from molten silicon by using electron beam melting was carried out. Based on the distributions of Al and Ca along the growth direction of the ingot under different solidification conditions, the influence of segregation and evaporation behaviors on the removal of such impurities with both high saturated vapor pressure and low segregation coefficients was investigated. The results showed that the distributions of impurities depend upon the interaction between segregation and evaporation, so that the removal efficiency can be further improved by adjusting the melting parameters. Compared with the traditional electron beam melting process, the energy consumption decreases by 20% during the whole melting and solidification process. It is considered to be a more effective way for the purification of silicon and the reduction of energy consumption by electron beam melting.

  1. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    Science.gov (United States)

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  2. Epigenetic Analysis of Heavy-ion Radiation Induced Bystander Effects in Mice

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Cui, Changna; Xue, Bei

    Abstract: Radiation-induced bystander effect was defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic and proteomics plays significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male Balb/c and C57BL mice were exposed head-only to 40, 200, 2000mGy dose of (12) C heavy-ion radiation, while the rest of the animal body was shielded. Directly radiation organ ear and the distant organ liver were detected on 1h, 6h, 12h and 24h after radiation, respectively. Methylation-sensitive amplification polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that heavy-ion irradiated mouse head could induce genomic DNA methylation changes significantly in both the directly radiation organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate was highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation. The global DNA methylation changes tended to occur in the CG sites. The results illustrated that genomic methylation changes of heavy ion radiation-induced bystander effect in liver could be obvious 1 h after radiation and achieved the maximum at 6 h, while the changes could recover gradually at 12 h. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in both directly radiation organ ear and distant organ liver. Moreover, our findings are important to understand the molecular mechanism of

  3. Modification of magnetic anisotropy induced by swift heavy ion irradiation in cobalt ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nongjai, Razia [Department of Applied Physics, Zakir Hussain College of Engineering & Technology, A.M.U., Aligarh 202002 (India); Khan, Shakeel, E-mail: skhanapad@gmail.com [Department of Applied Physics, Zakir Hussain College of Engineering & Technology, A.M.U., Aligarh 202002 (India); Ahmed, Hilal; Khan, Imran [Department of Applied Physics, Zakir Hussain College of Engineering & Technology, A.M.U., Aligarh 202002 (India); Annapoorni, S. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Gautam, Sanjeev [Advanced Analysis Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Lin, Hong-Ji; Chang, Fan-Hsiu [National Synchrotron Radiation Research Center (NSRRC), Hsinchu 30076, Taiwan (China); Hwa Chae, Keun [Advanced Analysis Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Asokan, K. [Material Science Division, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-11-15

    The present study demonstrates the modification of magnetic anisotropy in cobalt ferrite (CoFe{sub 2}O{sub 4}) thin films induced by swift heavy ion irradiations of 200 MeV Ag-ion beams. The study reveals that both magnetizations and coercive field are sensitive to Ag-ions irradiation and to the fluences. The magnetic anisotropy enhanced at low fluence of Ag-ions due to domain wall pinning at defect sites created by ion bombardment and at high fluence, this magnetic anisotropy ceases and changes to isotropic behavior which is explained based on the significant structural and morphological changes. An X-ray absorption and x-ray magnetic circular dichroism studies confirms the inverse spinel structure of these compounds. - Highlights: • CoFe{sub 2}O{sub 4} thin films have been deposited on Silicon substrate by pulsed laser deposition technique. • Swift heavy ion irradiation of thin films at three different fluences. • Studied the structural and magnetic properties of the samples. • XRD and Raman studies indicate strain in the films. • Observed perpendicular magnetic anisotropy.

  4. Xenon-ion-induced and thermal mixing of Co/Si bilayers and their interplay

    Science.gov (United States)

    Novaković, M.; Zhang, K.; Popović, M.; Bibić, N.; Hofsäss, H.; Lieb, K. P.

    2011-05-01

    Studies on ion-irradiated transition-metal/silicon bilayers demonstrate that interface mixing and silicide phase formation depend sensitively on the ion and film parameters, including the structure of the metal/Si interface. Thin Co layers e-gun evaporated to a thickness of 50 nm on Si(1 0 0) wafers were bombarded at room temperature with 400-keV Xe + ions at fluences of up to 3 × 10 16 cm -2. We used either crystalline or pre-amorphized Si wafers the latter ones prepared by 1.0-keV Ar-ion implantation. The as-deposited or Xe-ion-irradiated samples were then isochronally annealed at temperatures up to 700 °C. Changes of the bilayer structures induced by ion irradiation and/or annealing were investigated with RBS, XRD and HRTEM. The mixing rate for the Co/c-Si couples, Δ σ2/ Φ = 3.0(4) nm 4, is higher than the value expected for ballistic mixing and about half the value typical for spike mixing. Mixing of pre-amorphized Si is much weaker relative to crystalline Si wafers, contrary to previous results obtained for Fe/Si bilayers. Annealing of irradiated samples produces very similar interdiffusion and phase formation patterns above 400 °C as in the non-irradiated Co/Si bilayers: the phase evolution follows the sequence Co 2Si → CoSi → CoSi 2.

  5. Sign preference in ion-induced nucleation: contributions to the free energy barrier.

    Science.gov (United States)

    Keasler, Samuel J; Kim, Hyunmi; Chen, Bin

    2012-11-07

    We have performed a series of computer simulations using the AVUS-HR approach to better understand the origin of the sign preference in ion-induced nucleation. In particular, we emphasize the importance of distinguishing between the total formation free energy of a cluster, and the nucleation free energy, which involves only those steps contributing to the free energy barrier. We have separately considered how the ion-water potential energy, the water-water potential energy, and the entropy contribute to both the cluster formation free energy, and the nucleation free energy. These simulations have shown that while the ion-water potential energies make the largest contribution to the formation free energy difference between positive and negative ions, the entropy is the contribution leading to lower nucleation free energy barriers for negative ions. The primary reason for this is the larger stable (but precritical) clusters formed around negative ions. We have further shown that the distinction between formation and nucleation free energies is of particular importance when comparing small cations with larger anions where the formation free energies can be much lower for the cationic clusters, even though the nucleation barriers are lower for the anionic clusters.

  6. Light and Electron Microscopic Evaluation of Hydrogen Ion-Induced Brain Necrosis

    OpenAIRE

    Petito, C. K.; Kraig, R.P.; Pulsinelli, W. A.

    1987-01-01

    Excessive accumulation of hydrogen ions in the brain may play a pivotal role in initiating the necrosis seen in infarction and following hyperglycemic augmentation of ischemic brain damage. To examine possible mechanisms involved in hydrogen ion-induced necrosis, sequential structural changes in rat brain were examined following intracortical injection of sodium lactate solution (pH 4.5), as compared with injections at pH 7.3. Following pH 7.3 injection, neuronal swelling developed between 1 ...

  7. Photo and Collision Induced Isomerization of a Cyclic Retinal Derivative: An Ion Mobility Study.

    Science.gov (United States)

    Coughlan, Neville J A; Scholz, Michael S; Hansen, Christopher S; Trevitt, Adam J; Adamson, Brian D; Bieske, Evan J

    2016-09-01

    A cationic degradation product, formed in solution from retinal Schiff base (RSB), is examined in the gas phase using ion mobility spectrometry, photoisomerization action spectroscopy, and collision induced dissociation (CID). The degradation product is found to be N-n-butyl-2-(β-ionylidene)-4-methylpyridinium (BIP) produced through 6π electrocyclization of RSB followed by protonation and loss of dihydrogen. Ion mobility measurements show that BIP exists as trans and cis isomers that can be interconverted through buffer gas collisions and by exposure to light, with a maximum response at λ = 420 nm.Graphical Abstract.

  8. Electron emission induced by resonant coherent ion-surface interaction at grazing incidence

    Energy Technology Data Exchange (ETDEWEB)

    Garcia de Abajo, F.J. (Departamento de Ciencias de la Computacion e Inteligencia Artificial, Facultad de Informatica, Universidad del Pais Vasco, Apartado 649, 20080 San Sebastian (Spain)); Ponce, V.H. (Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche, Rio Negro (Argentina)); Echenique, P.M. (Departamento de Fisica de Materiales, Facultad de Quimica, Universidad del Pais Vasco, Apartado 1072, 20080 San Sebastian (Spain))

    1992-10-19

    A new spectroscopy based on the resonant coherently induced electron loss to the continuum in ion-surface scattering under grazing incidence is proposed. A series of peaks, corresponding to the energy differences determined by the resonant interaction with the rows of atoms in the surface, is predicted to appear in the energy distribution of electrons emitted from electronic states bound to the probe. Calculations for MeV He{sup +} ions scattered at a W(001) surface along the {l angle}100{r angle} direction with a glancing angle of 0--2 mrad show a total yield close to 1.

  9. Evaluation of Optical Depths and Self-Absorption of Strontium and Aluminum Emission Lines in Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Alfarraj, Bader A; Bhatt, Chet R; Yueh, Fang Yu; Singh, Jagdish P

    2017-04-01

    Laser-induced breakdown spectroscopy (LIBS) is a widely used laser spectroscopic technique in various fields, such as material science, forensic science, biological science, and the chemical and pharmaceutical industries. In most LIBS work, the analysis is performed using radiative transitions from atomic emissions. In this study, the plasma temperature and the product [Formula: see text] (the number density N and the absorption path length [Formula: see text]) were determined to evaluate the optical depths and the self-absorption of Sr and Al lines. A binary mixture of strontium nitrate and aluminum oxide was used as a sample, consisting of variety of different concentrations in powder form. Laser-induced breakdown spectroscopy spectra were collected by varying various parameters, such as laser energy, gate delay time, and gate width time to optimize the LIBS signals. Atomic emission from Sr and Al lines, as observed in the LIBS spectra of different sample compositions, was used to characterize the laser induced plasma and evaluate the optical depths and self-absorption of LIBS.

  10. Mitochondrial response and calcium ion change in apoptotic insect cells induced by SfaMNPV

    Institute of Scientific and Technical Information of China (English)

    XIU Meihong; PENG Jianxin; HONG Huazhu

    2005-01-01

    Mitochondrial responses and changes of calcium ions in apoptotic insect SL-1 cells induced by Syngrapha falcifera multiple nuclear polyhedrosis virus (SfaMNPV) are reported in this paper. By using Rhodamine 123 as a fluorescent labeling probe, flow cytometry analysis and confocal laser scanning microscope observation we observed that the mitochondrial transmembrane potential (△Ψm) began to decrease in SL-1 cells at 4 h post infection and △Ψm reduced continuously with the extension of virus infection. Western blotting indicated that the Bcl-2 level in the mitochondria gradually declined and was down- regulated. Cells undergoing apoptosis were found to have an elevation of cytochrome c in the cytosol and a corresponding decrease in the mitochondria, which indicated that cytochrome c was released from mitochondria into cytosol. These results suggest that mitochondrion-mediated apoptotic signal transduction pathway exists in apoptotic insect cell induced by SfaMNPV. Cytosolic free calcium ([Ca2+]i) concentration rapidly increased after SfaMNPV infection and the elevated calcium was tested to come partly from extracelllular calcium ion influx. Flow cytometry analysis indicated that the apoptosis in SL-1 cells was not influenced by established cytosolic calcium clamped conditions and the EGTA inhibiting calcium influx. Therefore, neither the elevation of cytosolic calcium ion nor extracellular calcium entry was the inducing factor of apoptosis, which hinted that the depletion of ER Ca2+ store contributed to SL-1 cell apoptosis induced by SfaMNPV.

  11. Modifications in surface, structural and mechanical properties of brass using laser induced Ni plasma as an ion source

    Directory of Open Access Journals (Sweden)

    Shahbaz Ahmad

    2016-03-01

    Full Text Available Laser induced Ni plasma has been employed as source of ion implantation for surface, structural and mechanical properties of brass. Excimer laser (248 nm, 20 ns, 120mJ and 30 Hz was used for the generation of Ni plasma. Thomson parabola technique was employed to estimate the energy of generated ions using CR39 as a detector. In response to stepwise increase in number of laser pulses from 3000 to 12000, the ion dose varies from 60 × 1013 to 84 × 1016 ions/cm2 with constant energy of 138 KeV. SEM analysis reveals the growth of nano/micro sized cavities, pores, pits, voids and cracks for the ion dose ranging from 60 × 1013 to 70 × 1015 ions/cm2. However, at maximum ion dose of 84 × 1016 ions/cm2 the granular morphology is observed. XRD analysis reveals that new phase of CuZnNi (200 is formed in the brass substrate after ion implantation. However, an anomalous trend in peak intensity, crystallite size, dislocation line density and induced stresses is observed in response to the implantation with various doses. The increase in ion dose causes to decrease the Yield Stress (YS, Ultimate Tensile Strength (UTS and hardness. However, for the maximum ion dose the highest values of these mechanical properties are achieved. The variations in the mechanical properties are correlated with surface and crystallographical changes of ion implanted brass.

  12. Raman Spectroscopy of Irradiation Effect in Three Carbon Allotropes Induced by Low Energy B Ions

    Institute of Scientific and Technical Information of China (English)

    FU Yun-Chong; JIN Yun-Fan; YAO Cun-Feng; ZHANG Chong-Hong

    2009-01-01

    Irradiation effect in three carbon allotropes C6o, diamond and highly oriented pyrolytic graphite (HOPG) induced by 170 keV B ions, mainly including the process of the damage creation, is investigated by means of Rarnan spectroscopy technique. The differences on irradiation sensitivity and structural stability for C6o, HOPG and diamond are compared. The analysis results indicate that C6o is the most sensitive for B ions irradiation, diamond is the second one and the structure of HOPG is the most stable under B ion irradiation. The damage cross sections σ of C6o, diamond and HOPG deduced from the Raman spectra are 7.78 × 10-15, 6.38 × 10-15 and 1.31 × 10-15 cm-2, respectively.

  13. Electromagnetically-induced-transparency ground-state cooling of long ion strings

    Science.gov (United States)

    Lechner, Regina; Maier, Christine; Hempel, Cornelius; Jurcevic, Petar; Lanyon, Ben P.; Monz, Thomas; Brownnutt, Michael; Blatt, Rainer; Roos, Christian F.

    2016-05-01

    Electromagnetically-induced-transparency (EIT) cooling is a ground-state cooling technique for trapped particles. EIT offers a broader cooling range in frequency space compared to more established methods. In this work, we experimentally investigate EIT cooling in strings of trapped atomic ions. In strings of up to 18 ions, we demonstrate simultaneous ground-state cooling of all radial modes in under 1 ms. This is a particularly important capability in view of emerging quantum simulation experiments with large numbers of trapped ions. Our analysis of the EIT cooling dynamics is based on a technique enabling single-shot measurements of phonon numbers, by rapid adiabatic passage on a vibrational sideband of a narrow transition.

  14. Discussion of the metric in characterizing the single-event effect induced by heavy ions

    Institute of Scientific and Technical Information of China (English)

    Zhang Ke-Ying; Zhang Feng-Qi; Luo Yin-Hong; Guo Hong-Xia

    2013-01-01

    The single-event effect (SEE) is the most serious problem in space environment.The modern semiconductor technology is concerned with the feasibility of the linear energy transfer (LET) as metric in characterizing SEE induced by heavy ions.In this paper,we calibrate the detailed static random access memory (SRAM) cell structure model of an advanced field programmable gate array (FPGA) device using the computer-aided design tool,and calculate the heavy ion energy loss in multi-layer metal utilizing Geant4.Based on the heavy ion accelerator experiment and numerical simulation,it is proved that the metric of LET at the device surface,ignoring the top metal material in the advanced semiconductor device,would underestimate the SEE.In the SEE evaluation in space radiation environment the top-layers on the semiconductor device must be taken into consideration.

  15. Cobalt ions induce chemokine secretion in a variety of systemic cell lines

    Science.gov (United States)

    2010-01-01

    Background and purpose Metal ion toxicity both locally and systemically following MoM hip replacements remains a concern. Cobalt ions have been shown to induce secretion of proinflammatory chemokines locally; however, little is known about their effect systemically. We investigated the in vitro effect of cobalt ions on a variety of cell lines by measuring production of the proinflammatory chemokines IL-8 and MCP-1. Method Renal, gastrointestinal, and respiratory epithelium and also neutrophils and monocytes were exposed to cobalt ions at 4, 12, 24, and 48 hours. Results We found that cobalt ions enhanced the secretion of IL-8 and MCP-1 in renal epithelial cells, gastric and colon epithelium, monocytes and neutrophils, and small airway epithelial cells but not in alveolar cells. Secretion of IL-8 and MCP-1 was markedly elevated in renal epithelium, where a 16-fold and 7-fold increase occurred compared to controls. There was a 6-fold and 4-fold increase in IL-8 and MCP-1 secretion in colon epithelium and a 4-fold and 3-fold increase in gastric epithelium. Small airway epithelial cells showed a maximum increase in secretion of 8-fold (IL-8) and of 4-fold (MCP-1). The increase in chemokine secretion observed in alveolar cells was moderate and did not reach statistical significance. Monocytes and neutrophils showed a 2.5-fold and 2-fold increase in IL-8 secretion and a 6-fold and 4-fold increase in MCP-1 secretion at 48 and 24 hours, respectively. Interpretation These data demonstrate the potent bioactivity of cobalt ions in a variety of cell types and the potential to induce a proinflammatory response. PMID:21110705

  16. Experimental evaluation of the pressure and temperature dependence of ion-induced nucleation.

    Science.gov (United States)

    Munir, Muhammad Miftahul; Suhendi, Asep; Ogi, Takashi; Iskandar, Ferry; Okuyama, Kikuo

    2010-09-28

    An experimental system for the study of ion-induced nucleation in a SO(2)/H(2)O/N(2) gas mixture was developed, employing a soft x-ray at different pressure and temperature levels. The difficulties associated with these experiments included the changes in physical properties of the gas mixture when temperature and pressure were varied. Changes in the relative humidity (RH) as a function of pressure and temperature also had a significant effect on the different behaviors of the mobility distributions of particles. In order to accomplish reliable measurement and minimize uncertainties, an integrated on-line control system was utilized. As the pressure decreased in a range of 500-980 hPa, the peak concentration of both ions and nanometer-sized particles decreased, which suggests that higher pressure tended to enhance the growth of particles nucleated by ion-induced nucleation. Moreover, the modal diameters of the measured particle size distributions showed a systematic shift to larger sizes with increasing pressure. However, in the temperature range of 5-20 °C, temperature increases had no significant effects on the mobility distribution of particles. The effects of residence time, RH (7%-70%), and SO(2) concentration (0.08-6.7 ppm) on ion-induced nucleation were also systematically investigated. The results show that the nucleation and growth were significantly dependent on the residence time, RH, and SO(2) concentration, which is in agreement with both a previous model and previous observations. This research will be inevitable for a better understanding of the role of ions in an atmospheric nucleation mechanism.

  17. Early and Late Chromosome Damages in Human Lymphocytes Induced by Gamma Rays and Fe Ions

    Science.gov (United States)

    Sunagawa, Mayumi; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2014-01-01

    Chromosomal translocations and inversions are considered stable, and cells containing these types of chromosome aberrations can survive multiple cell divisions. An efficient method to detect an inversion is multi-color banding fluorescent in situ hybridization (mBAND) which allows identification of both inter- and intrachromosome aberrations simultaneously. Post irradiation, chromosome aberrations may also arise after multiple cell divisions as a result of genomic instability. To investigate the stable or late-arising chromosome aberrations induced after radiation exposure, we exposed human lymphocytes to gamma rays and Fe ions ex vivo, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis and at several time intervals during the culture period post irradiation. With gamma irradiation, about half of the damages observed at first mitosis remained after 7 day- and 14 day- culture, suggesting the transmissibility of damages to the surviving progeny. Detailed analysis of chromosome break ends participating in exchanges revealed a greater fraction of break ends involved in intrachromosome aberrations in the 7- and 14-day samples in comparison to the fraction at first mitosis. In particular, simple inversions were found at 7 and 14 days, but not at the first mitosis, suggesting that some of the aberrations might be formed days post irradiation. In contrast, at the doses that produced similar frequencies of gamma-induced chromosome aberrations as observed at first mitosis, a significantly lower yield of aberrations remained at the same population doublings after Fe ion exposure. At these equitoxic doses, more complex type aberrations were observed for Fe ions, indicating that Fe ion-induced initial chromosome damages are more severe and may lead to cell death. Comparison between low and high doses of Fe ion irradiation in the induction of late damages will also be discussed.

  18. Direct Observation of Lattice Aluminum Environments in Li Ion Cathodes LiNi 1–yz Co y Al z O 2 and Al-Doped LiNi x Mn y Co z O 2 via 27 Al MAS NMR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, Fulya; Vaughey, John T.; Iddir, Hakim; Key, Baris

    2016-07-06

    Direct observations of local lattice aluminum environments have been a major challenge for aluminum -bearing Li ion battery materials, such as LiNi1-y-zCoyAlzO2 Al(NCA) and aluminum-doped LiNixMnyCozO2 (NMC). Al-27 magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy is the only structural probe currently available that can qualitatively and quantitatively characterize lattice and nonlattice (i.e., surface, coatings, segregation, secondary phase etc.) aluminum coordination and provide information that helps discern its effect in the lattice. In the present study, we use NMR to gain new insights into transition metal (TM)-O-Al coordination and evolution of lattice aluminum sites upon cycling. With the aid of first-principles DFT calculations, we show direct evidence of lattice Al sites, nonpreferential Ni/Co-O-Al ordering in NCA, and the lack of bulk lattice aluminum in aluminum -"doped" NMC. Aluminum coordination of the paramagnetic (lattice) and diamagnetic (nonlattice) nature is investigated for Al-doped NMC and NCA. For the latter, the evolution of the lattice site(s) upon cycling is also studied. A clear reordering of lattice aluminum environments due to nickel migration is observed in NCA upon extended cycling.

  19. Laser-induced fluorescence from N2(+) ions generated by a corona discharge in ambient air.

    Science.gov (United States)

    Konthasinghe, Kumarasiri; Fitzmorris, Kristin; Peiris, Manoj; Hopkins, Adam J; Petrak, Benjamin; Killinger, Dennis K; Muller, Andreas

    2015-09-01

    In this work, we present the measurement of laser-induced fluorescence from N2(+) ions via the B(2)Σu(+)-X(2)Σg(+) band system in the near-ultraviolet. The ions were generated continuously by a plasma glow discharge in low pressure N2 and by a corona discharge in ambient air. The fluorescence decay time was found to rapidly decrease with increasing pressure leading to an extrapolated decay rate of ≍10(10) s(-1) at atmospheric pressure. In spite of this quenching, we were able to observe laser induced fluorescence in ambient air by means of a time-gated spectral measurement. In the process of comparing the emission signal with that of N2 spontaneous Raman scattering, ion concentrations in ambient air of order 10(8-)10(10) cm(-3) were determined. With moderate increases in laser power and collection efficiency, ion concentrations of less than 10(6) cm(-3) may be measurable, potentially enabling applications in atmospheric standoff detection of ionizing radiation from hazardous radioactive sources.

  20. Aluminum phosphate shows more adjuvanticity than Aluminum hydroxide in recombinant hepatitis –B vaccine formulation

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Background: Although a number of investigation have been carried out to find alternative adjuvants to aluminum salts in vaccine formulations, they are still extensively used due to their good track record of safety, low cost and proper adjuvanticity with a variety of antigens. Adsorption of antigens onto aluminum compounds depends heavily on electrostatic forces between adjuvant and antigen. Commercial recombinant protein hepatitis B vaccines containing aluminum hydroxide as adjuvant is facing low induction of immunity in some sections of the vaccinated population. To follow the current global efforts in finding more potent hepatitis B vaccine formulation, adjuvanticity of aluminum phosphate has been compared to aluminum hydroxide. Materials and methods: The adjuvant properties of aluminum hydroxide and aluminum phosphate in a vaccine formulation containing a locally manufactured hepatitis B (HBs surface antigen was evaluated in Balb/C mice. The formulations were administered intra peritoneally (i.p. and the titers of antibody which was induced after 28 days were determined using ELISA technique. The geometric mean of antibody titer (GMT, seroconversion and seroprotection rates, ED50 and relative potency of different formulations were determined. Results: All the adjuvanicity markers obtained in aluminum phosphate formulation were significantly higher than aluminum hydroxide. The geometric mean of antibody titer of aluminum phosphate was approximately three folds more than aluminum hydroxide. Conclusion: Aluminum phosphate showed more adjuvanticity than aluminum hydroxide in hepatitis B vaccine. Therefore the use of aluminum phosphate as adjuvant in this vaccine may lead to higher immunity with longer duration of effects in vaccinated groups.

  1. Multicharged ion-induced emission from metal- and insulator surfaces related to magnetic fusion research

    Energy Technology Data Exchange (ETDEWEB)

    Winter, H.P. [Technische Univ., Vienna (Austria). Inst. fuer Allgemeine Physik

    1997-01-01

    The edge region of magnetically confined plasmas in thermonuclear fusion experiments couples the hot plasma core with the cold first wall. We consider the dependence of plasma-wall interaction processes on edge plasma properties, with particular emphasis on the role of slow multicharged ions (MCI). After a short survey on the physics of slow MCI-surface interaction we discuss recent extensive studies on MCI-induced electron emission from clean metal surfaces conducted at impact velocities << 1 a.u., from which generally reliable total electron yields can be obtained. We then demonstrate the essentially different role of the MCI charge for electron emission from metallic and insulator surfaces, respectively. Furthermore, we present recent results on slow MCI-induced `potential sputtering` of insulators which, in contrast to the well established kinetic sputtering, already occurs at very low ion impact energy and strongly increases with the MCI charge state. (J.P.N.). 55 refs.

  2. Solar cycle dynamic of the Martian induced magnetosphere. Planetary ions acceleration zones and escape.

    Science.gov (United States)

    Fedorov, Andrey; Modolo, Ronan; Jarvinen, Riku; Barabash, Stas

    2016-10-01

    This work presents a massive statistical analysis of the ion flows in the Martian induced magnetosphere. We performed this analysis using Mars Express ion mass spectrometer data taken during 2008 - 2013 time interval. This data allows to make an enhanced study of the induced magnetosphere variations as a response of the solar activity level. Since Mars Express has no onboard magnetometer, we used the hybrid models of the Martian plasma environment to get a proper frame to make an adequate statistics of the magnetospheric response. In this paper we present a spatial distribution of the planetary plasma properties in the planetary wake as well as the ionosospheric escape as a function of the solar activity.

  3. Microbeam Studies of Diffusion Time Resolved Ion Beam Induced Charge Collection from Stripe-Like Junctions

    Energy Technology Data Exchange (ETDEWEB)

    GUO,B.N.; BOUANANI,M.E.; RENFROW,S.N.; WALSH,DAVID S.; DOYLE,BARNEY L.; ATON,T.J.; SMITH,E.B.; BAUMANN,R.C.; DUGGAN,J.L.; MCDANIEL,F.D.

    2000-06-14

    To design more radiation tolerant Integrated Circuits (ICs), it is essential to create and test accurate models of ionizing radiation induced charge collection dynamics within microcircuits. A new technique, Diffusion Time Resolved Ion Beam Induced Charge Collection (DTRIBICC), is proposed to measure the average arrival time of the diffused charge at the junction. Specially designed stripe-like junctions were experimentally studied using a 12 MeV carbon microbeam with a spot size of 1 {micro}m. The relative arrival time of ion-generated charge is measured along with the charge collection using a multiple parameter data acquisition system. The results show the importance of the diffused charge collection by junctions, which is especially significant in accounting for Multiple Bit Upset (MBUs) in digital devices.

  4. Probing the nuclear symmetry energy with heavy-ion reactions induced by neutron-rich nuclei

    Institute of Scientific and Technical Information of China (English)

    CHEN Lie-wen; KO Che-Ming; LI Bao-an; YONG Gao-chan

    2007-01-01

    Heavy-ion reactions induced by neutron-rich nuclei provide a unique means to investigate the equation of state of isospin-asymmetric nuclear matter,especially the density dependence of the nuclear symmetry energy.In particular,recent analyses of the isospin diffusion data in heavyion reactions have already put a stringent constraint on thenuclear symmetry energy around the nuclear matter saturation density.We review this exciting result and discuss its implications on nuclear effective interactions and the neutron skin thickness of heavy nuclei.In addition,we also review the theoretical progress on probing the high density behaviors of the nuclear symmetry energy in heavy-ion reactions induced by high energy radioactive beams.

  5. Energetic-particle-driven instabilities and induced fast-ion transport in a reversed field pinch

    Science.gov (United States)

    Lin, Liang

    2013-10-01

    Multiple bursty energetic-particle (EP) modes with fishbone-like structures are observed during 1 MW tangential neutral-beam injection into MST reversed field pinch (RFP) plasmas. The distinguishing features of the RFP, including large magnetic shear (tending to add stability) and weak toroidal magnetic field (leading to large fast ion beta and stronger drive), provide a complementary environment to tokamak and stellarator configurations for exploring basic understanding of these instabilities. Detailed measurements of the EP mode characteristics and temporal-spatial dynamics reveal their influence on fast ion transport and interaction with global tearing modes. Internal magnetic field fluctuations associated with the EP modes are directly observed for the first time by Faraday-effect polarimetry (frequency ~ 90 kHz and amplitude ~ 2 G). Simultaneously measured density fluctuations exhibit a dynamically evolving and asymmetric spatial structure that peaks near the core where fast ions reside and shifts outward as the instability evolves. Furthermore, the EP mode frequencies appear at ~k∥VA , consistent with continuum modes destabilized by strong drive. The fast-ion temporal dynamics, measured by a neutral particle analyzer, resemble a classical predator-prey relaxation oscillation. It contains a slow-growing phase arising from the beam fueling followed by a rapid drop (~ 15 %) when the EP modes peak, indicating the fluctuation-induced transport maintains a stiff fast-ion density profile. The inferred transport rate is strongly enhanced (× 2) with the onset of multiple nonlinearly-interacting EP modes. The fast ions also impact global tearing modes, reducing their amplitudes by up to 65%. This mode reduction is lessened following the EP-bursts, further evidence for fast ion redistribution that weakens the suppression mechanism. Possible tearing mode suppression mechanisms will be discussed. Work supported by US DoE.

  6. Multi-shell model of ion-induced nucleic acid condensation

    Science.gov (United States)

    Tolokh, Igor S.; Drozdetski, Aleksander V.; Pollack, Lois; Baker, Nathan A.; Onufriev, Alexey V.

    2016-04-01

    We present a semi-quantitative model of condensation of short nucleic acid (NA) duplexes induced by trivalent cobalt(iii) hexammine (CoHex) ions. The model is based on partitioning of bound counterion distribution around single NA duplex into "external" and "internal" ion binding shells distinguished by the proximity to duplex helical axis. In the aggregated phase the shells overlap, which leads to significantly increased attraction of CoHex ions in these overlaps with the neighboring duplexes. The duplex aggregation free energy is decomposed into attractive and repulsive components in such a way that they can be represented by simple analytical expressions with parameters derived from molecular dynamic simulations and numerical solutions of Poisson equation. The attractive term depends on the fractions of bound ions in the overlapping shells and affinity of CoHex to the "external" shell of nearly neutralized duplex. The repulsive components of the free energy are duplex configurational entropy loss upon the aggregation and the electrostatic repulsion of the duplexes that remains after neutralization by bound CoHex ions. The estimates of the aggregation free energy are consistent with the experimental range of NA duplex condensation propensities, including the unusually poor condensation of RNA structures and subtle sequence effects upon DNA condensation. The model predicts that, in contrast to DNA, RNA duplexes may condense into tighter packed aggregates with a higher degree of duplex neutralization. An appreciable CoHex mediated RNA-RNA attraction requires closer inter-duplex separation to engage CoHex ions (bound mostly in the "internal" shell of RNA) into short-range attractive interactions. The model also predicts that longer NA fragments will condense more readily than shorter ones. The ability of this model to explain experimentally observed trends in NA condensation lends support to proposed NA condensation picture based on the multivalent "ion binding

  7. Bombardment induced ion transport - part IV: ionic conductivity of ultra-thin polyelectrolyte multilayer films.

    Science.gov (United States)

    Wesp, Veronika; Hermann, Matthias; Schäfer, Martin; Hühn, Jonas; Parak, Wolfgang J; Weitzel, Karl-Michael

    2016-02-14

    The dependence of the ionic conductance of ultra-thin polyelectrolyte multilayer (PEM) films on the temperature and the number of bilayers has been investigated by the recently developed low energy bombardment induced ion transport (BIIT) method. To this end multilayers of alternating poly(sodium 4-styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) layers were deposited on a metal electrode and subsequently bombarded by a low energy potassium ion beam. Ions are transported through the film according to the laws of electro-diffusion towards a grounded backside electrode. They are neutralized at the interface between the polymer film and the metal electrode. The detected neutralization current scales linearly with the acceleration potential of the ion beam indicating Ohmic behavior for the (PAH/PSS)x multilayer, where x denotes the number of bilayers. The conductance exhibits a non-monotonic dependence on the number of bilayers, x. For 2 ≤ x ≤ 8 the conductance increases non-linearly with the number of bilayers. For x ≥ 8 the conductance decreases with increasing number of bilayers. The variation of the conductance is rationalized by a model accounting for the structure dependence of the conductivity. The thinnest sample for which the conductance has been measured is the single bilayer reflecting properties dominated by the interface. The activation energy for the ion transport is 0.49 eV.

  8. Global change induced trends in ion composition of the troposphere to the lower thermosphere

    Directory of Open Access Journals (Sweden)

    G. Beig

    2008-05-01

    Full Text Available In this paper a brief overview of the changes in atmospheric ion compositions driven by the human-induced changes in related neutral species, and temperature from the troposphere to lower thermosphere has been made. It is found that ionic compositions undergo significant variations. The variations calculated for the double-CO2 scenario are both long-term and permanent in nature. Major neutrals which take part in the lower and middle atmospheric ion chemical schemes and undergo significant changes due to anthropogenic activities are: O, O2, H2O, NO, acetonitrile, pyridinated compounds, acetone and aerosol. The concentration of positive ion/electron density does not change appreciably in the middle atmosphere but indicates a marginal decrease above about 75 km until about 85 km, above which the magnitude of negative trend decreases and becomes negligible at 93 km. Acetonitrile cluster ions in the upper stratosphere are likely to increase, whereas NO+ and NO+(H2O in the mesosphere and lower thermosphere (MLT region are expected to decrease for the double CO2 scenario. It is also found that the atmospheric density of pyridinated cluster ions is fast rising in the troposphere.

  9. Heavy-ion radiation induced Photosynthesis changes in Oryza sativa L.

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Li, Xishan; Meng, Qingmei

    The abnormal development of rice was observed frequently after the seed was exposed to heavy-ion radiation. The heavy-ion radiation could change the chloroplast structure in mesophyll cell by decreasing chloroplast grana and loosing the thylakoid lamellas. To study the mechanism of heavy-ion radiation induced photosynthesis changes, rice seed was exposed to 0-20 Gy dose of (12) C radiation. By measuring the changes of chlorophyll fluorescence parameters, the content of chlorophyll as well as the expression of CP24 in the leaves of rice at the three-leaf stage, we analyzed the influence mechanism of heavy-ion radiation on photosynthesis in rice. The results indicated that chlorophyll fluorescence parameter Fv/Fm and content of chlorophyll (including chlorophyll a, chlorophyll b and total chlorophyll) changed significantly in different doses. Both the relative expression of CP24 and its encoding gene lhcb6 altered after exposed to different dose of radiation. By using Pearson correlation analysis, we found that the 1 Gy was the bound of low-dose radiation. The possible molecular mechanisms and biological consequences of the observed changes are discussed. Key Words: Heavy-ion Radiation; Rice; Photosynthesis; Fv/Fm; CP24.

  10. Ion beam induced single phase nanocrystalline TiO{sub 2} formation

    Energy Technology Data Exchange (ETDEWEB)

    Rukade, Deepti A. [Department of Physics, University of Mumbai, Mumbai 400098 (India); Tribedi, L.C. [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India); Bhattacharyya, Varsha, E-mail: varsha.b1.physics@gmail.com [Department of Physics, University of Mumbai, Mumbai 400098 (India)

    2014-06-15

    Single phase TiO{sub 2} nanostructures are fabricated by oxygen ion implantation (60 keV) at fluence ranging from 1×10{sup 16} ions/cm{sup 2} to 1×10{sup 17} ions/cm{sup 2} in titanium thin films deposited on fused silica substrate and subsequent thermal annealing in argon atmosphere. GAXRD and Raman spectroscopy study reveals formation of single rutile phases of TiO{sub 2}. Particle size is found to vary from 29 nm to 35 nm, establishing nanostructure formation. Nanostructure formation is also confirmed by the quantum confinement effect manifested by the blueshift of the UV–vis absorption spectra. Photoluminescence spectra show peaks corresponding to TiO{sub 2} rutile phase and reveal the presence of oxygen defects due to implantation. The controlled synthesis of single phase nanostructure is attributed to ion induced defects and post-implantation annealing. It is observed that the size of the nanostructures formed is strongly dependent on the ion fluence.

  11. The Solubilization of Model Alzheimer Tangles: Reversing the β-Sheet Conformation Induced by Aluminum with Silicates

    Science.gov (United States)

    Fasman, Gerald D.; Moore, Cathy D.

    1994-11-01

    Neurofibrillary tangles are one of two lesions found in the brain of Alzheimer disease victims. With synthetic peptide fragments of human neurofilament NF-M17 (Glu-Glu-Lys-Gly-Lys-Ser-Pro-Val-Pro-Lys-Ser-Pro-Val-Glu-Glu-Lys-Gly, phosphorylated and unphosphorylated), CD studies were done to examine the effect of sodium orthosilicate on the conformational state produced by Al3+ on fragments of neuronal proteins. Previous studies had shown a conformational transition from α-helix and random to β-pleated sheet upon addition of Al3+ to both phosphorylated and unphosphorylated peptides. If sufficient quantities of Al3+ are added, the peptide precipitates from solution. The ability to reverse or slow the progression of aggregation was examined. Al3+ binding was reversed with 1-2 molar equivalents of sodium orthosilicate (with respect to Al3+), altering the conformation from β-sheet to random coil and resulting in a CD spectrum similar to that of the initial peptide. The tight binding of the SiO4-_4 with the Al3+ provides the mechanism for this transition. These results provide additional information toward understanding the role of aluminum in the Alzheimer diseased brain and suggest the investigation of the possible use of silicates as a therapeutic agent.

  12. Radiation hardness of polysiloxane scintillators analyzed by ion beam induced luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Quaranta, A., E-mail: quaranta@ing.unitn.i [University of Trento, Dipartimento di Ingegneria dei Materiali e delle Tecnologie Industriali - DIMTI, Via Mesiano 77, I-38050 Povo, Trento (Italy); INFN, Laboratori Nazionali di Legnaro, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy); Carturan, S. [Universita di Padova, Laboratori Nazionali di Legnaro, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy); Marchi, T.; Antonaci, A. [INFN, Laboratori Nazionali di Legnaro, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy); Scian, C. [Universita di Padova, Laboratori Nazionali di Legnaro, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy); Kravchuk, V.L. [Universita di Bologna, Dipartimento di Fisica, Viale Carlo Berti Pichat 6, I-40127 Bologna (Italy); Degerlier, M.; Gramegna, F. [INFN, Laboratori Nazionali di Legnaro, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy); Maggioni, G. [Universita di Padova, Laboratori Nazionali di Legnaro, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy)

    2010-10-01

    The radiation hardness of polysiloxane based scintillators has been measured by ion beam induced luminescence (IBIL). The light intensity as a function of the irradiation fluence with an He{sup +} beam at 1.8 MeV (1.0 {mu}A/cm{sup 2}) has been measured on undoped polymers synthesized with different amounts of phenyl units and on polysiloxanes doped with two different dye molecules (BBOT and Lumogen Violet) sensitizing the scintillation yield.

  13. Polystyrene nanoparticle exposure induces ion-selective pores in lipid bilayers

    Science.gov (United States)

    Negoda, Alexander; Kim, Kwang-Jin; Crandall, Edward D.; Worden, Robert M.

    2014-01-01

    A diverse range of molecular interactions can occur between engineered nanomaterials (ENM) and biomembranes, some of which could lead to toxic outcomes following human exposure to ENM. In this study, we adapted electrophysiology methods to investigate the ability of 20 nm polystyrene nanoparticles (PNP) to induce pores in model bilayer lipid membranes (BLM) that mimic biomembranes. PNP charge was varied using PNP decorated with either positive (amidine) groups or negative (carboxyl) groups, and BLM charge was varied using dioleoyl phospholipids having cationic (ethylphosphocholine), zwitterionic (phosphocholine), or anionic (phosphatidic acid) headgroups. Both positive and negative PNP induced BLM pores for all lipid compositions studied, as evidenced by current spikes and integral conductance. Stable PNP-induced pores exhibited ion selectivity, with the highest selectivity for K+ (PK/PCl ~ 8.3) observed when both the PNP and lipids were negatively charged, and the highest selectivity for Cl− (PK/PCl ~ 0.2) observed when both the PNP and lipids were positively charged. This trend is consistent with the finding that selectivity for an ion in channel proteins is imparted by oppositely charged functional groups within the channel’s filter region. The PK/PCl value was unaffected by the voltage-ramp method, the pore conductance, or the side of the BLM to which the PNP were applied. These results demonstrate for the first time that PNP can induce ion-selective pores in BLM, and that the degree of ion selectivity is influenced synergistically by the charges of both the lipid headgroups and functional groups on the PNP. PMID:23747366

  14. Ion-Irradiation-Induced Ferromagnetism in Undoped ZnO Thin Films

    Science.gov (United States)

    2013-01-01

    Ion-irradiation-induced ferromagnetism in undoped ZnO thin filmsq Siddhartha Mal a,⇑, Sudhakar Nori a, J. Narayan a, J.T. Prater b, D.K. Avasthi c...S, Narayan J, Nori S, Prater JT, Kumar D. Solid State Commun 2010;150:1660. [8] Mal S, Nori S, Jin C, Narayan J, Nellutla S, Smirnov AI, et al. J

  15. Aluminum recovery as a product with high added value using aluminum hazardous waste.

    Science.gov (United States)

    David, E; Kopac, J

    2013-10-15

    The samples of hazardous aluminum solid waste such as dross were physically and chemically characterized. A relationship between density, porosity and metal content of dross was established. The paper also examines the chemical reactions involving aluminum dross in landfill and the negative consequences. To avoid environmental problems and to recovery the aluminum, a processing method was developed and aluminum was recovered as an added value product such as alumina. This method refers to a process at low temperature, in more stages: acid leaching, purification, precipitation and calcination. At the end of this process aluminum was extracted, first as Al(3+) soluble ions and final as alumina product. The composition of the aluminum dross and alumina powder obtained were measured by applying the leaching tests, using atomic absorption spectrometry (AAS) and chemical analysis. The mineralogical composition of aluminum dross samples and alumina product were determined by X-ray diffraction (XRD) and the morphological characterization was performed by scanning electron microscopy (SEM). The method presented in this work allows the use of hazardous aluminum solid waste as raw material to recover an important fraction from soluble aluminum content as an added value product, alumina, with high grade purity (99.28%). Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Ion irradiation induced enhancement of out-of-plane magnetic anisotropy in ultrathin Co films

    Energy Technology Data Exchange (ETDEWEB)

    Mazalski, P.; Kurant, Z.; Maziewski, A. [Faculty of Physics, University of Bialystok, Bialystok (Poland); Liedke, M. O.; Fassbender, J. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Baczewski, L. T.; Wawro, A. [Institute of Physics, Polish Academy of Science, Warszawa (Poland)

    2013-05-07

    Ga{sup +} or He{sup +} irradiated MBE grown ultrathin films of sapphire/Pt/Co(d{sub Co})/Pt(d{sub Pt}) were studied using polar Kerr effect in wide ranges of both cobalt d{sub Co} and platinum d{sub Pt} thicknesses as well as ion fluences F. Two branches of increased magnetic anisotropy and enhanced Kerr rotation angle induced by Ga{sup +} or He{sup +} irradiation are clearly visible in two-dimensional (d{sub Co}, LogF) diagrams. Only Ga{sup +} irradiation induces two branches of out-of-plane magnetization state.

  17. Nitrate reductase-mediated early nitric oxide burst alleviates oxidative damage induced by aluminum through enhancement of antioxidant defenses in roots of wheat (Triticum aestivum).

    Science.gov (United States)

    Sun, Chengliang; Lu, Lingli; Liu, Lijuan; Liu, Wenjing; Yu, Yan; Liu, Xiaoxia; Hu, Yan; Jin, Chongwei; Lin, Xianyong

    2014-03-01

    • Nitric oxide (NO) is an important signaling molecule involved in the physiological processes of plants. The role of NO release in the tolerance strategies of roots of wheat (Triticum aestivum) under aluminum (Al) stress was investigated using two genotypes with different Al resistances. • An early NO burst at 3 h was observed in the root tips of the Al-tolerant genotype Jian-864, whereas the Al-sensitive genotype Yang-5 showed no NO accumulation at 3 h but an extremely high NO concentration after 12 h. Stimulating NO production at 3 h in the root tips of Yang-5 with the NO donor relieved Al-induced root inhibition and callose production, as well as oxidative damage and ROS accumulation, while elimination of the early NO burst by NO scavenger aggravated root inhibition in Jian-864. • Synthesis of early NO in roots of Jian-864 was mediated through nitrate reductase (NR) but not through NO synthase. Elevated antioxidant enzyme activities were induced by Al stress in both wheat genotypes and significantly enhanced by NO donor, but suppressed by NO scavenger or NR inhibitor. • These results suggest that an NR-mediated early NO burst plays an important role in Al resistance of wheat through modulating enhanced antioxidant defense to adapt to Al stress.

  18. Studies on the optimum conditions using acid-washed zero-valent iron/aluminum mixtures in permeable reactive barriers for the removal of different heavy metal ions from wastewater.

    Science.gov (United States)

    Han, Weijiang; Fu, Fenglian; Cheng, Zihang; Tang, Bing; Wu, Shijiao

    2016-01-25

    The method of permeable reactive barriers (PRBs) is considered as one of the most practicable approaches in treating heavy metals contaminated surface and groundwater. The mixture of acid-washed zero-valent iron (ZVI) and zero-valent aluminum (ZVAl) as reactive medium in PRBs to treat heavy metal wastewater containing Cr(VI), Cd(2+), Ni(2+), Cu(2+), and Zn(2+) was investigated. The performance of column filled with the mixture of acid-washed ZVI and ZVAl was much better than the column filled with ZVI or ZVAl alone. At initial pH 5.4 and flow rates of 1.0 mL/min, the time that the removal efficiencies of Cr(VI), Cd(2+), Ni(2+), Cu(2+), and Zn(2+) were all above 99.5% can keep about 300 h using 80 g/40 g acid-washed ZVI/ZVAl when treating wastewater containing each heavy metal ions (Cr(VI), Cd(2+), Ni(2+), Cu(2+), and Zn(2+)) concentration of 20.0 mg/L. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize ZVI/ZVAl before and after reaction and the reaction mechanism of the heavy metal ions with ZVI/ZVAl was discussed.

  19. Characterization of radiation damage induced by swift heavy ions in graphite

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, Christian

    2016-05-15

    Graphite is a classical material in neutron radiation environments, being widely used in nuclear reactors and power plants as a moderator. For high energy particle accelerators, graphite provides ideal material properties because of the low Z of carbon and its corresponding low stopping power, thus when ion projectiles interact with graphite is the energy deposition rather low. This work aims to improve the understanding of how the irradiation with swift heavy ions (SHI) of kinetic energies in the range of MeV to GeV affects the structure of graphite and other carbon-based materials. Special focus of this project is given to beam induced changes of thermo-mechanical properties. For this purpose the Highly oriented pyrolytic graphite (HOPG) and glassy carbon (GC) (both serving as model materials), isotropic high density polycrystalline graphite (PG) and other carbon based materials like carbon fiber carbon composites (CFC), chemically expanded graphite (FG) and molybdenum carbide enhanced graphite composites (MoC) were exposed to different ions ranging from {sup 131}Xe to {sup 238}U provided by the UNILAC accelerator at GSI in Darmstadt, Germany. To investigate structural changes, various in-situ and off-line measurements were performed including Raman spectroscopy, x-ray diffraction and x-ray photo-electron spectroscopy. Thermo-mechanical properties were investigated using the laser-flash-analysis method, differential scanning calorimetry, micro/nano-indentation and 4-point electrical resistivity measurements. Beam induced stresses were investigated using profilometry. Obtained results provided clear evidence that ion beam-induced radiation damage leads to structural changes and degradation of thermal, mechanical and electrical properties of graphite. PG transforms towards a disordered sp2 structure, comparable to GC at high fluences. Irradiation-induced embrittlement is strongly reducing the lifetime of most high-dose exposed accelerator components. For

  20. Effect of co-existing ions during the preparation of alumina by electrolysis with aluminum soluble electrodes: Structure and defluoridation activity of electro-synthesized adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Tchomgui-Kamga, Eric, E-mail: etchomgui@yahoo.fr [UMR CNRS n°6226 Institut des Sciences Chimiques de Rennes, ENSCR, Avenue du Général Leclerc, CS 50837 - 35708 Rennes Cedex 7 (France); Laboratoire de Chimie Analytique, Faculté des Sciences, Université de Yaoundé-I, BP 812 Yaoundé (Cameroon); Audebrand, Nathalie, E-mail: nathalie.audebrand@univ-rennes1.fr [UMR CNRS n°6226 Institut des Sciences Chimiques de Rennes, Université de Rennes-1, Avenue du Général Leclerc, 35042 Rennes Cedex (France); Darchen, André, E-mail: Andre.Darchen@ensc-rennes.fr [UMR CNRS n°6226 Institut des Sciences Chimiques de Rennes, ENSCR, Avenue du Général Leclerc, CS 50837 - 35708 Rennes Cedex 7 (France)

    2013-06-15

    Highlights: • pH increases during electrocoagulation with aluminum electrodes are rationalized. •Composition of electrogenerated aluminas is dependent upon the electrolyte used. • All the electrogenerated aluminas contained nanoparticles of boehmite AlOOH. • The defluoridation activity of the aluminas was dependent upon the electrolyte used. -- Abstract: The electrochemical dissolution of aluminum was carried out to prepare hydrated aluminas which were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), chemical titrations and defluoridation activities. Aluminas were obtained at controlled pH depending upon the counter cations of the electrolyte. A boehmite AlOOH phase was isolated mainly in ammonium solution, while aluminas synthesized in the other media contained a mixture of phases, usually both boehmite and bayerite γ-Al(OH){sub 3}. All the boehmite phases contained nano-crystallites of less than 3 nm. Batch defluoridation experiments revealed a second influence of the original electrolyte. Aluminas were very effective in defluoridation with abatement rates of 99.5%, 98.5% and 97.3% from neutral fluoride solution at 10 mg L{sup −1} when they were prepared in solution of (NH{sub 4}){sub 2}SO{sub 4}, (NH{sub 4})HCO{sub 2} and NH{sub 4}Cl, respectively. The maximum fluoride capacities were 46.94; 10.25 and 12.18 mg g{sup −1} for aluminas prepared in solution of (NH{sub 4}){sub 2}SO{sub 4}; (NH{sub 4})HCO{sub 2} and NH{sub 4}Cl, respectively. The amount of dissolved Al was found to be less than 0.19 mg L{sup −1} at neutral pH. These results show that a defluoridation with electro-synthesized aluminas would be more efficient and safe than a direct electrocoagulation.

  1. Intense heavy ion beam-induced effects in carbon-based stripper foils

    Energy Technology Data Exchange (ETDEWEB)

    Kupka, Katharina

    2016-08-15

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

  2. Understanding Aspects of Aluminum Exposure in Alzheimer's Disease Development.

    Science.gov (United States)

    Kandimalla, Ramesh; Vallamkondu, Jayalakshmi; Corgiat, Edwin B; Gill, Kiran Dip

    2016-03-01

    Aluminum is a ubiquitously abundant nonessential element. Aluminum has been associated with neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis, and dialysis encephalopathy. Many continue to regard aluminum as controversial although increasing evidence supports the implications of aluminum in the pathogenesis of AD. Aluminum causes the accumulation of tau protein and Aβ protein in the brain of experimental animals. Aluminum induces neuronal apoptosis in vivo and in vitro, either by endoplasmic stress from the unfolded protein response, by mitochondrial dysfunction, or a combination of them. Some, people who are exposed chronically to aluminum, either from through water and/or food, have not shown any AD pathology, apparently because their gastrointestinal barrier is more effective. This article is written keeping in mind mechanisms of action of aluminum neurotoxicity with respect to AD.

  3. Linkage determination of linear oligosaccharides by MS(n) (n > 2) collision-induced dissociation of Z₁ ions in the negative ion mode.

    Science.gov (United States)

    Konda, Chiharu; Bendiak, Brad; Xia, Yu

    2014-02-01

    Obtaining unambiguous linkage information between sugars in oligosaccharides is an important step in their detailed structural analysis. An approach is described that provides greater confidence in linkage determination for linear oligosaccharides based on multiple-stage tandem mass spectrometry (MS(n), n >2) and collision-induced dissociation (CID) of Z1 ions in the negative ion mode. Under low energy CID conditions, disaccharides (18)O-labeled on the reducing carbonyl group gave rise to Z1 product ions (m/z 163) derived from the reducing sugar, which could be mass-discriminated from other possible structural isomers having m/z 161. MS(3) CID of these m/z 163 ions showed distinct fragmentation fingerprints corresponding to the linkage types and largely unaffected by sugar unit identities or their anomeric configurations. This unique property allowed standard CID spectra of Z1 ions to be generated from a small set of disaccharide samples that were representative of many other possible isomeric structures. With the use of MS(n) CID (n = 3 - 5), model linear oligosaccharides were dissociated into overlapping disaccharide structures, which were subsequently fragmented to form their corresponding Z1 ions. CID data of these Z1 ions were collected and compared with the standard database of Z1 ion CID using spectra similarity scores for linkage determination. As the proof-of-principle tests demonstrated, we achieved correct determination of individual linkage types along with their locations within two trisaccharides and a pentasaccharide.

  4. A new setup for the investigation of swift heavy ion induced particle emission and surface modifications

    Energy Technology Data Exchange (ETDEWEB)

    Meinerzhagen, F.; Breuer, L.; Bukowska, H.; Herder, M.; Schleberger, M.; Wucher, A. [Fakultät für Physik, Universität Duisburg-Essen and Cenide, 47057 Duisburg (Germany); Bender, M.; Severin, D. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Lebius, H. [CIMAP (CEA-CNRS-ENSICAEN-UCN), 14070 Caen Cedex 5 (France)

    2016-01-15

    The irradiation with fast ions with kinetic energies of >10 MeV leads to the deposition of a high amount of energy along their trajectory (up to several ten keV/nm). The energy is mainly transferred to the electronic subsystem and induces different secondary processes of excitations, which result in significant material modifications. A new setup to study these ion induced effects on surfaces will be described in this paper. The setup combines a variable irradiation chamber with different techniques of surface characterizations like scanning probe microscopy, time-of-flight secondary ion, and neutral mass spectrometry, as well as low energy electron diffraction under ultra high vacuum conditions, and is mounted at a beamline of the universal linear accelerator (UNILAC) of the GSI facility in Darmstadt, Germany. Here, samples can be irradiated with high-energy ions with a total kinetic energy up to several GeVs under different angles of incidence. Our setup enables the preparation and in situ analysis of different types of sample systems ranging from metals to insulators. Time-of-flight secondary ion mass spectrometry enables us to study the chemical composition of the surface, while scanning probe microscopy allows a detailed view into the local electrical and morphological conditions of the sample surface down to atomic scales. With the new setup, particle emission during irradiation as well as persistent modifications of the surface after irradiation can thus be studied. We present first data obtained with the new setup, including a novel measuring protocol for time-of-flight mass spectrometry with the GSI UNILAC accelerator.

  5. A new setup for the investigation of swift heavy ion induced particle emission and surface modifications

    Science.gov (United States)

    Meinerzhagen, F.; Breuer, L.; Bukowska, H.; Bender, M.; Severin, D.; Herder, M.; Lebius, H.; Schleberger, M.; Wucher, A.

    2016-01-01

    The irradiation with fast ions with kinetic energies of >10 MeV leads to the deposition of a high amount of energy along their trajectory (up to several ten keV/nm). The energy is mainly transferred to the electronic subsystem and induces different secondary processes of excitations, which result in significant material modifications. A new setup to study these ion induced effects on surfaces will be described in this paper. The setup combines a variable irradiation chamber with different techniques of surface characterizations like scanning probe microscopy, time-of-flight secondary ion, and neutral mass spectrometry, as well as low energy electron diffraction under ultra high vacuum conditions, and is mounted at a beamline of the universal linear accelerator (UNILAC) of the GSI facility in Darmstadt, Germany. Here, samples can be irradiated with high-energy ions with a total kinetic energy up to several GeVs under different angles of incidence. Our setup enables the preparation and in situ analysis of different types of sample systems ranging from metals to insulators. Time-of-flight secondary ion mass spectrometry enables us to study the chemical composition of the surface, while scanning probe microscopy allows a detailed view into the local electrical and morphological conditions of the sample surface down to atomic scales. With the new setup, particle emission during irradiation as well as persistent modifications of the surface after irradiation can thus be studied. We present first data obtained with the new setup, including a novel measuring protocol for time-of-flight mass spectrometry with the GSI UNILAC accelerator.

  6. 废旧锂离子电池正极材料中钴铝同浸过程研究%Study on Cobalt and Aluminum Leaching Process from Spent Lithium Ion Batteries Cathode Materials

    Institute of Scientific and Technical Information of China (English)

    尹晓莹; 满瑞林; 赵鹏飞; 常伟; 徐筱群

    2013-01-01

    Through calculation of basic thermodynamics data and drawing of E-pH diagram of reaction system , the leaching process of recovery of cobalt and aluminum from spent lithium ion battery cathode materials was carried out. The effects of sulfuric acid concentration, leaching time, leaching temperature, hydrogen peroxide dosage and ratio of solid to liquid (L/S) on leaching rate of cobalt and aluminum were investigated. The results show that under the conditions including 273 K, - 0. 277 < E < (1. 612 -0. 1182pH) , and pH<2. 17, aluminum can transform LiCoO2 into Co2+. As the leaching rate of cobalt was relatively low due to the limit in dynamics, a proper auxiliary reductant was necessary in the leaching process. The leaching rate of cobalt is 98. 5% and the recovery of aluminum foil is 76. 5% under the optimum leaching conditions including concentration of H2SO4 of 5 mol/L, reacting time of 120 min, temperature of 85 ℃ , and dosage of hydrogen peroxide of 0. 5 mL/g, 98. 6% of aluminum in lixivium is removed by ammonium hydrogen carbonate with the end pH value of 4. 5.%通过基础热力学数据计算以及绘制反应体系的E-pH图,对废旧锂离子电池正极材料回收中钴铝同浸过程进行研究,考察了硫酸浓度、浸出时间、浸出温度、双氧水用量及液固比对钴、铝浸出率的影响.结果表明,在273 K,-0.277<E<(1.612-0.1182pH),pH<2.17时,铝可以将LiCoO2转化为Co2+,但由于动力学原因,钴的浸出并不完全,需要加入辅助还原剂双氧水.正极在1.5 mol/L H2SO4、反应时间120 min、反应温度85℃、双氧水0.5 mL/g的条件下浸出,钴浸出率可以达到98.5%,同时可以回收76.5%的铝箔.使用碳酸氢铵除铝,终点pH为4.5时,可以除去浸出液中98.6%的铝.

  7. IMF-induced escape of molecular ions from the Martian ionosphere

    Directory of Open Access Journals (Sweden)

    Y. Kubota

    2013-08-01

    Full Text Available Since Mars does not possess a significant global intrinsic magnetic field, the solar wind interacts directly with the Martian ionosphere and can induce ion escapes from it. Phobos-2 and recent Mars Express (MEX observations have shown that the escaping ions are O+ as well as molecular O2+ and CO2+. While O+ escape can be understood by the ion pick-up of non-thermal O corona extended around the planet, regarding the heavy molecular O2+ and CO2+, which are buried in the lower ionosphere, a novel escape mechanism needs to considered. Here we attack this problem by global magnetohydrodynamic (MHD simulations. First, we clarify the global structure of the streamlines that result from the interaction with the solar wind. Then, by focusing on the streamlines that dip into the low-altitude part of the dayside ionosphere, we investigate the escape path of the molecular ions. The effects of the interplanetary magnetic field (IMF on the molecular ion escape process are investigated by comparing the results with and without IMF. IMF has little effect on O+ escape via ion pick-up mediated by solar wind electron impact ionization of the O corona. O2+ and CO2+ are shoveled from the low-altitude regions of the dayside ionosphere by magnetic tension in the presence of IMF. These ions are pulled by the U-shaped field lines to the north and south poles, and at the terminator, they are concentrated in the noon–midnight meridian plane. These ions remain confined to the noon–midnight plane as they are transported to the nightside to form the tail ray. Then they escape along the streamlines open to the interplanetary space. Under a typical solar wind and IMF condition expected at Mars, O+, O2+ and CO2+ escape fluxes are 8.0 × 1023, 3.5 × 1023 and 5.0 × 1022 ion s−1, respectively, which are in good agreement with the MEX observations.

  8. Drug-induced Inhibition and Trafficking Disruption of ion Channels: Pathogenesis of QT Abnormalities and Drug-induced Fatal Arrhythmias.

    Science.gov (United States)

    Cubeddu, Luigi X

    2016-01-01

    Risk of severe and fatal ventricular arrhythmias, presenting as Torsade de Pointes (TdP), is increased in congenital and acquired forms of long QT syndromes (LQTS). Drug-induced inhibition of K+ currents, IKs, IKr, IK1, and/or Ito, delay repolarization, prolong QT, and increase the risk of TdP. Drug-induced interference with IKr is the most common cause of acquired LQTS/TdP. Multiple drugs bind to KNCH2-hERG-K+ channels affecting IKr, including antiarrythmics, antibiotics, antivirals, azole-antifungals, antimalarials, anticancer, antiemetics, prokinetics, antipsychotics, and antidepressants. Azithromycin has been recently added to this list. In addition to direct channel inhibition, some drugs interfere with the traffic of channels from the endoplasmic reticulum to the cell membrane, decreasing mature channel membrane density; e.g., pentamidine, geldalamicin, arsenic trioxide, digoxin, and probucol. Other drugs, such as ketoconazole, fluoxetine, norfluoxetine, citalopram, escitalopram, donepezil, tamoxifen, endoxifen, atazanavir, and roxitromycin, induce both direct channel inhibition and impaired channel trafficking. Although many drugs prolong the QT interval, TdP is a rare event. The following conditions increase the risk of drug-induced TdP: a) Disease states/electrolyte levels (heart failure, structural cardiac disease, bradycardia, hypokalemia); b) Pharmacogenomic variables (presence of congenital LQTS, subclinical ion-channel mutations, history of or having a relative with history of drug-induced long QT/TdP); c) Pharmacodynamic and kinetic factors (high doses, women, elderly, metabolism inhibitors, combining two or more QT prolonging drugs, drugs that prolong the QT and increase QT dispersion, and drugs with multiple actions on ion channels). Because most of these conditions are preventable, careful evaluation of risk factors and increased knowledge of drug use associated with repolarization abnormalities are strongly recommended.

  9. An Ideal System for Analysis and Interpretation of Ion Beam Induced Luminescence

    Science.gov (United States)

    Townsend, P. D.; Crespillo, M. L.

    Luminescence is produced during ion beam implantation or ion-solid interaction for most insulators, and contains rich information. Surprisingly, the information extracted is often far from optimum. Rather than summarizing literature work, the focus here is to design an optimized and feasible target chamber that could offer far more information than what has currently been obtained. Such an improved and multi-probe approach opens a range of options to simultaneously record luminescence spectra generated by the ion beam, explore transient and excited state signals via probes of secondary excitation methods (such as ionisation or photo-stimulation). In addition, one may monitor optical absorption, reflectivity and lifetime dependent features, plus stress and polarization factors. A particularly valuable addition to conventional measurements is to have the ability to modulate both the ion beam and the probes. These features allow separation of transient lifetimes, as well as sensing intermediate steps in the defect formation and/or relaxation, and growth of new phases and nanoparticle inclusions. While luminescence methods are the most sensitive probes of defect and imperfection sites in optically active materials, less work has been performed at controlled low and high temperatures. Measurement with controlled cooling or heating of the samples is effective to reveal phase transitions (both of host and inclusions). Furthermore, simultaneous excitations (e.g. ions and photons) at different temperatures may lead to different end-phase or stale structure under extreme ionization conditions and enable fabrication of unique material structures. References to the existing literature will underline that the overall benefits of studying ion beam induced luminescence can be far more fruitful than that has normally been considered.

  10. Xenon-ion-induced and thermal mixing of Co/Si bilayers and their interplay

    Energy Technology Data Exchange (ETDEWEB)

    Novakovic, M. [VINCA Institute of Nuclear Sciences, 11001 Belgrade (Serbia); II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Zhang, K. [II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Popovic, M.; Bibic, N. [VINCA Institute of Nuclear Sciences, 11001 Belgrade (Serbia); II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Hofsaess, H. [II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Lieb, K.P., E-mail: plieb@gwdg.d [II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

    2011-05-01

    Studies on ion-irradiated transition-metal/silicon bilayers demonstrate that interface mixing and silicide phase formation depend sensitively on the ion and film parameters, including the structure of the metal/Si interface. Thin Co layers e-gun evaporated to a thickness of 50 nm on Si(1 0 0) wafers were bombarded at room temperature with 400-keV Xe{sup +} ions at fluences of up to 3 x 10{sup 16} cm{sup -2}. We used either crystalline or pre-amorphized Si wafers the latter ones prepared by 1.0-keV Ar-ion implantation. The as-deposited or Xe-ion-irradiated samples were then isochronally annealed at temperatures up to 700 {sup o}C. Changes of the bilayer structures induced by ion irradiation and/or annealing were investigated with RBS, XRD and HRTEM. The mixing rate for the Co/c-Si couples, {Delta}{sigma}{sup 2}/{Phi} = 3.0(4) nm{sup 4}, is higher than the value expected for ballistic mixing and about half the value typical for spike mixing. Mixing of pre-amorphized Si is much weaker relative to crystalline Si wafers, contrary to previous results obtained for Fe/Si bilayers. Annealing of irradiated samples produces very similar interdiffusion and phase formation patterns above 400 {sup o}C as in the non-irradiated Co/Si bilayers: the phase evolution follows the sequence Co{sub 2}Si {yields} CoSi {yields} CoSi{sub 2}.

  11. Melting, growth, and faceting of lead precipitates in aluminum

    DEFF Research Database (Denmark)

    Gråbæk, L.; Bohr, J.; Andersen, H.H.

    1992-01-01

    Aluminum single crystals cut in the direction were implanted with 2 x 10(20) m-2 Pb+ ions at 75 or 150 keV. The implanted insoluble lead precipitated as epitaxially oriented crystallites in the aluminum matrix. The precipitates were studied by x-ray diffraction at Riso, DESY, and Brookhaven...

  12. Radiation damage mechanisms in CsI(Tl) studied by ion beam induced luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Quaranta, Alberto [Dipartimento di Ingegneria dei Materiali e delle Tecnologie Industriali - DIMTI, Universita di Trento, Via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy)], E-mail: quaranta@ing.unitn.it; Gramegna, Fabiana; Kravchuk, Vladimir [Laboratori Nazionali di Legnaro - INFN, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy); Scian, Carlo [Dipartimento di Ingegneria dei Materiali e delle Tecnologie Industriali - DIMTI, Universita di Trento, Via Mesiano 77, I-38050 Povo, Trento (Italy); Laboratori Nazionali di Legnaro - INFN, Via dell' Universita 2, I-35020 Legnaro, Padova (Italy)

    2008-06-15

    Ion beam induced luminescence (IBIL) has been used to study the kinetics of defect production under ion beam irradiation in CsI(Tl) crystals with different Tl{sup +} concentrations (250, 560, 3250 and 6500 ppm). The crystals have been irradiated with H{sup +} and {sup 4}He{sup +} at 1.8 MeV. Both the scintillator spectra after irradiation and the intensity decrease at different wavelengths as a function of the fluence have been measured. The emission bands shift to higher wavelengths after irradiation, and the light decrease has been interpolated following a saturation model for the point defect concentration. Crystals with low Tl{sup +} concentrations present the UV emission peak of pure CsI at 300 nm whose intensity during H{sup +} irradiation and reaches a maximum under He{sup +} irradiation. At low Tl{sup +} concentrations the damage rate depends on the ion stopping power, while at higher concentrations it depends on the activator concentration. The results can be interpreted by assuming that the defects affecting the light emission are point defects nearby Tl{sup +} ions.

  13. Ion-induced effects on metallic nanoparticles; Ioneninduzierte Effekte an metallischen Nanoteilchen

    Energy Technology Data Exchange (ETDEWEB)

    Klimmer, Andreas

    2010-02-25

    This work deals with the ion-irradiation of metallic nanoparticles in combination with various substrates. Particle diameters were systematically varied within the range of 2.5-14 nm, inter-particle distances range from 30-120 nm. Irradiations were performed with various inert gas ions with energies of 200 keV, resulting in an average ion range larger than the particle dimensions and therefore the effects of irradiation are mainly due to creation of structural defects within the particles and the underlying substrate as well. The main part of this work deals with ion-induced burrowing of metallic nanoparticles into the underlying substrate. The use of micellar nanoparticles with sharp size distribution combined with AFM and TEM analysis allows a much more detailed look at this effect than other works on that topic so far. With respect to the particle properties also a detailed look on the effect of irradiation on the particle structure would be interesting, which might lead to a deliberate influence on magnetic properties, for example. Within the context of this work, first successful experiments were performed on FePt particles, showing a significant reduction of the ordering temperature leading to the magnetically interesting, ordered L1{sub 0} phase. (orig.)

  14. Parameterization of ion-induced nucleation rates based on ambient observations

    Directory of Open Access Journals (Sweden)

    T. Nieminen

    2011-04-01

    Full Text Available Atmospheric ions participate in the formation of new atmospheric aerosol particles, yet their exact role in this process has remained unclear. Here we derive a new simple parameterization for ion-induced nucleation or, more precisely, for the formation rate of charged 2-nm particles. The parameterization is semi-empirical in the sense that it is based on comprehensive results of one-year-long atmospheric cluster and particle measurements in the size range ~1–42 nm within the EUCAARI (European Integrated project on Aerosol Cloud Climate and Air Quality interactions project. Data from 12 field sites across Europe measured with different types of air ion and cluster mobility spectrometers were used in our analysis, with more in-depth analysis made using data from four stations with concomitant sulphuric acid measurements. The parameterization is given in two slightly different forms: a more accurate one that requires information on sulfuric acid and nucleating organic vapor concentrations, and a simpler one in which this information is replaced with the global radiation intensity. These new parameterizations are applicable to all large-scale atmospheric models containing size-resolved aerosol microphysics, and a scheme to calculate concentrations of sulphuric acid, condensing organic vapours and cluster ions.

  15. Nano-ranged low-energy ion-beam-induced DNA transfer in biological cells

    Science.gov (United States)

    Yu, L. D.; Wongkham, W.; Prakrajang, K.; Sangwijit, K.; Inthanon, K.; Thongkumkoon, P.; Wanichapichart, P.; Anuntalabhochai, S.

    2013-06-01

    Low-energy ion beams at a few tens of keV were demonstrated to be able to induce exogenous macromolecules to transfer into plant and bacterial cells. In the process, the ion beam with well controlled energy and fluence bombarded living cells to cause certain degree damage in the cell envelope in nanoscales to facilitate the macromolecules such as DNA to pass through the cell envelope and enter the cell. Consequently, the technique was applied for manipulating positive improvements in the biological species. This physical DNA transfer method was highly efficient and had less risk of side-effects compared with chemical and biological methods. For better understanding of mechanisms involved in the process, a systematic study on the mechanisms was carried out. Applications of the technique were also expanded from DNA transfer in plant and bacterial cells to DNA transfection in human cancer cells potentially for the stem cell therapy purpose. Low-energy nitrogen and argon ion beams that were applied in our experiments had ranges of 100 nm or less in the cell envelope membrane which was majorly composed of polymeric cellulose. The ion beam bombardment caused chain-scission dominant damage in the polymer and electrical property changes such as increase in the impedance in the envelope membrane. These nano-modifications of the cell envelope eventually enhanced the permeability of the envelope membrane to favor the DNA transfer. The paper reports details of our research in this direction.

  16. Swelling of SiO{sub 2} quartz induced by energetic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Trautmann, C.; Schwartz, K. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Costantini, J.M. [CEA Centre d`Etudes de Bruyeres-le-Chatel, 91 (France). DPTA/PMC; Meftah, A. [ENSET, Skikda (Algeria); Stoquert, J.P. [Centre National de la Recherche Scientifique, 67 - Strasbourg (France). Lab. PHASE; Toulemonde, M. [Centre Interdisciplinaire de Recherches avec les Ions Lourds (CIRIL), 14 - Caen (France)

    1997-12-01

    A pronounced swelling effect occurs when irradiating SiO{sub 2} quartz with heavy ions (F, S, Cu, Kr, Xe, Ta, and Pb) in the electronic energy loss regime. Using a profilometer, the out-of-plane swelling was measured by scanning over the border line between an irradiated and a virgin area of the sample surface. The step height varied between 20 and 300 nm depending on the fluence, the electronic energy loss and the total range of the ions. From complementary Rutherford backscattering experiments under channelling condition (RBS-C), the damage fraction and corresponding track radii were extracted. Normalising the step height per incoming ion and by the projected range, a critical energy loss of 1.8{+-}0.5 keV/nm was found which is in good agreement with the threshold observed by RBS-C. Swelling can be explained by the amorphisation induced along the ion trajectories. The experimental results in quartz are compared to swelling data obtained under similar irradiation conditions in LiNbO{sub 3}. (orig.)

  17. Molecule modification andmass deposition induced bythe implantation of lowenergy Fe+ ion beamsinto amino acids

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Fe+ ion beams with the energy of 110 keV were implanted into films of L(+)-cysteine (HSCH2CH(NH2)COOH). One of the single crystals grown in hydrochloric acid solution with the implanted samples through slow evaporation was structurally characterized by the X-ray crystallography. The crystal is monoclinic, space group C2, with a = 1.8534(4) nm, b = 0.5234(1) nm, c = 0.7212(1) nm, β= 103.72°, V = 0.67965(3) nm3, Z = 4, F(000) = 144.0, Dclac = 1.763 g@cm-3, μ(MoKα) = 1.06 mm-1, T = 293(2) K. R = 0.0379, wR = 0.0835 for 660 observed reflections (I > 2σ(I)). The structural formula of the crystal compound is (CH2CH(NH2)NO2)ClFe (Mr = 180.38 u). Products of heavy ion beam irradiation were purified and it was directly confirmed that the implanted Fe+ ions had been deposited in the novel molecules. The same doses of Fe+ ion beams of the same energy were implanted into films of L(+)-cysteine hydrochloride monohydrate. FTIR spectroscopy of the implanted samples proved that some of the original molecules were seriously damaged and significant modifications were induced.

  18. Cation disordering in magnesium aluminate spinel crystals induced by electron or ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Soeda, Takeshi E-mail: soeda@regroup5.nucl.kyushu-u.ac.jp; Matsumura, Syo; Kinoshita, Chiken; Zaluzec, Nestor J

    2000-12-01

    Structural changes in magnesium aluminate spinel (MgO {center_dot} nAl{sub 2}O{sub 3}) single crystals, which were irradiated with 900 keV electrons or 1 MeV Ne{sup +} ions at 873 K, were examined by electron channeling enhanced X-ray microanalysis. Unirradiated MgO {center_dot} Al{sub 2}O{sub 3} has a tendency to form the normal spinel configuration, where Mg{sup 2+} ions and Al{sup 3+} ions occupy mainly the tetrahedral and the octahedral sites, respectively. Electron irradiation induces simple cation disordering between the tetrahedral sites and the octahedral sites in MgO {center_dot} Al{sub 2}O{sub 3}. In addition to cation disordering, slight evacuation of cations from the tetrahedral sites to the octahedral sites occurs in a peak-damaged area in MgO {center_dot} Al{sub 2}O{sub 3} irradiated with Ne{sup +} ions. In contrast, cation disordering is suppressed in MgO {center_dot} 2.4Al{sub 2}O{sub 3} irradiated with electrons. The structural vacancies, present in the non-stoichiometric compound, appear to be effective in promoting irradiation damage recovery through interstitial-vacancy recombination.

  19. A comparison of neon versus helium ion beam induced deposition via Monte Carlo simulations.

    Science.gov (United States)

    Timilsina, Rajendra; Smith, Daryl A; Rack, Philip D

    2013-03-22

    The ion beam induced nanoscale synthesis of PtCx (where x ∼ 5) using the trimethyl (methylcyclopentadienyl)platinum(IV) (MeCpPt(IV)Me3) precursor is investigated by performing Monte Carlo simulations of helium and neon ions. The helium beam leads to more lateral growth relative to the neon beam because of its larger interaction volume. The lateral growth of the nanopillars is dominated by molecules deposited via secondary electrons in both the simulations. Notably, the helium pillars are dominated by SE-I electrons whereas the neon pillars are dominated by SE-II electrons. Using a low precursor residence time of 70 μs, resulting in an equilibrium coverage of ∼4%, the neon simulation has a lower deposition efficiency (3.5%) compared to that of the helium simulation (6.5%). At larger residence time (10 ms) and consequently larger equilibrium coverage (85%) the deposition efficiencies of helium and neon increased to 49% and 21%, respectively; which is dominated by increased lateral growth rates leading to broader pillars. The nanoscale growth is further studied by varying the ion beam diameter at 10 ms precursor residence time. The study shows that total SE yield decreases with increasing beam diameters for both the ion types. However, helium has the larger SE yield as compared to that of neon in both the low and high precursor residence time, and thus pillars are wider in all the simulations studied.

  20. Nano-ranged low-energy ion-beam-induced DNA transfer in biological cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-15

    Low-energy ion beams at a few tens of keV were demonstrated to be able to induce exogenous macromolecules to transfer into plant and bacterial cells. In the process, the ion beam with well controlled energy and fluence bombarded living cells to cause certain degree damage in the cell envelope in nanoscales to facilitate the macromolecules such as DNA to pass through the cell envelope and enter the cell. Consequently, the technique was applied for manipulating positive improvements in the biological species. This physical DNA transfer method was highly efficient and had less risk of side-effects compared with chemical and biological methods. For better understanding of mechanisms involved in the process, a systematic study on the mechanisms was carried out. Applications of the technique were also expanded from DNA transfer in plant and bacterial cells to DNA transfection in human cancer cells potentially for the stem cell therapy purpose. Low-energy nitrogen and argon ion beams that were applied in our experiments had ranges of 100 nm or less in the cell envelope membrane which was majorly composed of polymeric cellulose. The ion beam bombardment caused chain-scission dominant damage in the polymer and electrical property changes such as increase in the impedance in the envelope membrane. These nano-modifications of the cell envelope eventually enhanced the permeability of the envelope membrane to favor the DNA transfer. The paper reports details of our research in this direction.

  1. 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...

  2. Chemical modifications of polymer films induced by high energy heavy ions

    Science.gov (United States)

    Zhu, Zhiyong; Sun, Youmei; Liu, Changlong; Liu, Jie; Jin, Yunfan

    2002-06-01

    Polymer films including polyethylene terephthalate (PET), polystyrene (PS) and polycarbonate (PC) were irradiated at room temperature with ions of 35 MeV/u 40Ar, 25 MeV/u 84Kr, 15.1 MeV/u 136Xe and 11.4 MeV/u 238U to fluences ranging from 9×10 9 to 5.5×10 12 ions/cm 2. The radiation-induced chemical changes of the materials were investigated by Fourier-transform infrared (FTIR) and ultraviolet/visible spectroscopies. It is found that the absorbance in the ultraviolet and visible range induced by all irradiations follows a linear relationship with fluence. The radiation-induced absorbance normalized to one particle increases slowly with increasing of electronic energy loss below about 8 keV/nm followed by a sharp increase up to about 15 keV/nm above which saturation is reached. FTIR measurements reveal that the materials suffer serious degradation through bond breaking. The absorbance of the typical infrared bands decays exponentially with increase of ion fluence and the bond-disruption cross-section shows a sigmoid variation with electronic energy loss. In PET loss of crystallinity is attributed to the configuration transformation of the ethylene glycol residue from trans into the gauche. Alkyne end groups are induced in all the materials above certain electronic energy loss threshold, which is found to be about 0.8 keV/nm for PS and 0.4 keV/nm for PC. The production cross-section of alkyne end group increases with increasing of electronic energy loss and shows saturation at high electronic energy loss values. It is concluded that not only the physical processes but also the chemical processes of the energy deposition determine the modification of polymer.

  3. Chemical modifications of polymer films induced by high energy heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhiyong E-mail: zyzhu@impcas.ac.cn; Sun Youmei; Liu Changlong; Liu Jie; Jin Yunfan

    2002-06-01

    Polymer films including polyethylene terephthalate (PET), polystyrene (PS) and polycarbonate (PC) were irradiated at room temperature with ions of 35 MeV/u {sup 40}Ar, 25 MeV/u {sup 84}Kr, 15.1 MeV/u {sup 136}Xe and 11.4 MeV/u {sup 238}U to fluences ranging from 9x10{sup 9} to 5.5x10{sup 12} ions/cm{sup 2}. The radiation-induced chemical changes of the materials were investigated by Fourier-transform infrared (FTIR) and ultraviolet/visible spectroscopies. It is found that the absorbance in the ultraviolet and visible range induced by all irradiations follows a linear relationship with fluence. The radiation-induced absorbance normalized to one particle increases slowly with increasing of electronic energy loss below about 8 keV/nm followed by a sharp increase up to about 15 keV/nm above which saturation is reached. FTIR measurements reveal that the materials suffer serious degradation through bond breaking. The absorbance of the typical infrared bands decays exponentially with increase of ion fluence and the bond-disruption cross-section shows a sigmoid variation with electronic energy loss. In PET loss of crystallinity is attributed to the configuration transformation of the ethylene glycol residue from trans into the gauche. Alkyne end groups are induced in all the materials above certain electronic energy loss threshold, which is found to be about 0.8 keV/nm for PS and 0.4 keV/nm for PC. The production cross-section of alkyne end group increases with increasing of electronic energy loss and shows saturation at high electronic energy loss values. It is concluded that not only the physical processes but also the chemical processes of the energy deposition determine the modification of polymer.

  4. Proton and Fe Ion-Induced Early and Late Chromosome Aberrations in Different Cell Types

    Science.gov (United States)

    Lu, Tao; Zhang, Ye; Yeshitla, Samrawit; Bowler, Deborah; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2016-01-01

    Genomic instability, induced by various metabolic, genetic, and environmental factors, is the driving force of tumorigenesis. Radiation exposure from different types of radiation sources induces different types of DNA damages, increases mutation and chromosome aberration rates, and increases cellular transformation in vitro and in vivo experiments. The cell survival rates and frequency of chromosome aberrations depend on the genetic background and radiation sources. To further understand genomic instability induced by charged particles, we exposed human lymphocytes ex vivo, human fibroblast cells, human mammary epithelial cells, and bone marrow cells isolated from CBA/CaH and C57BL/6 mice to high energy protons and Fe ions, and collected chromosomes at different generations after exposure. Chromosome aberrations were analyzed with fluorescent in situ hybridization with whole chromosome specific probes.

  5. Inhibition of aluminum corrosion using Opuntia extract

    Energy Technology Data Exchange (ETDEWEB)

    El-Etre, A.Y

    2003-11-01

    The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions.

  6. Magnetic Configuration Effects on Fast Ion Losses Induced by Fast Ion Driven Toroidal Alfv~n Eigenmodes in the Large Helical Device

    Institute of Scientific and Technical Information of China (English)

    K. OGAWA; M. ISOBE; K. TOI; F. WATANABE; D. A. SPONG; A. SHIMIZU; M. OSAKABE; D. S. DARROW; S. OHDACHI; S. SAKAKIBARA; LHD Experiment -Group

    2012-01-01

    Beam-ion losses induced by fast-ion-driven toroidal Alfven eigenmodes (TAE) were measured with a scintillator-based lost fast-ion probe (SLIP) in the large helical device (LHD). The SLIP gave simultaneously the energy E and the pitch angle X=arccos(v///v) distribution of the lost fast ions. The loss fluxes were investigated for three typical magnetic configurations of Rax-vac=3.60 m, 3.75 m. and 3.90 m, where Rax-vac is the magnetic axis position of the vacuum field. Dominant losses induced by TAEs in these three configurations were observed in the E/X regions of 50-190 keV/40°, 40-170 keV/25°, and 30-190 keV/30°, respectively. Lost-ion fluxes induced by TAEs depend clearly on the amplitude of TAE magnetic fluctuations, Rax-vac and the toroidal field strength Bt. The increment of the loss fluxes has the dependence of (bTAE/Bt)s. The power s increases from s = 1 to 3 with the increase of the magnetic axis position in finite beta plasmas.

  7. Swift heavy ion induced structural and luminescence characterization of Y₂O₃:Eu³⁺ phosphor: a comparative study.

    Science.gov (United States)

    Som, S; Sharma, S K; Lochab, S P

    2014-08-01

    We report a comparative study on structural and thermoluminescence modifications of Y2O3:Eu(3+) phosphor induced by 150 MeV Ni(7+), 120 MeV Ag(9+) and 110 MeV Au(8+) swift heavy ions (SHI) in the fluence range 1 × 10(11) to 1 × 10(13) ions/cm(2). X-Ray diffraction and transition electron microscopy studies confirm the loss of crystallinity of the phosphors after ion irradiation, which is greater in the case of Au ion irradiation. Structural refinement using the Rietveld method yields the various structural parameters of ion-irradiated phosphors. Thermoluminescence glow curves of ion-irradiated phosphors show a small shift in the position of the peaks, along with an increase in intensity with ion fluence. Stopping range of ions in Matter (SRIM) calculations were performed to correlate the change in thermoluminescence properties of various ion-irradiated phosphors. It shows that the defects created by 110 MeV Au(8+) ions are greater in number. Trapping parameters of ion-irradiated phosphors were calculated from thermoluminescence data using various glow curve analysis methods.

  8. Laser-induced fluorescence measurement of the ion-energy-distribution function in a collisionless reconnection experiment.

    Science.gov (United States)

    Stark, A; Fox, W; Egedal, J; Grulke, O; Klinger, T

    2005-12-02

    Observations in space and laboratory plasmas suggest magnetic reconnection as a mechanism for ion heating and formation of non-Maxwellian ion velocity distribution functions (IVDF). Laser-induced fluorescence measurements of the IVDF parallel to the X line of a periodically driven reconnection experiment are presented. A time-resolved analysis yields the evolution of the IVDF within a reconnection cycle. It is shown that reconnection causes a strong increase of the ion temperature, where the strongest increase is found at the maximum reconnection rate. Monte Carlo simulations demonstrate that ion heating is a consequence of the in-plane electric field that forms around the X line in response to reconnection.

  9. Comparison of plasma parameters and line emissions of laser-induced plasmas of an aluminum target using single and orthogonal double nanosecond/picosecond pulses

    Energy Technology Data Exchange (ETDEWEB)

    Sobral, H., E-mail: martin.sobral@ccadet.unam.mx; Sanginés, R.

    2014-04-01

    The emission of laser-induced plasma on aluminum targets in air was investigated with nanosecond- and picosecond-pulsed Nd:YAG laser emitting at the fundamental wavelength. Orthogonal double pulse in pre-ablation and reheating configurations was also performed where the picosecond laser was employed to ablate the target. Ablation fluences were kept fixed at 100 J cm{sup −2} regardless of the laser pulse duration. Time integrated emission spectroscopy was employed to determine the plasma emission; thus, picosecond laser ablation provided larger figures than the nanosecond one. The emission was further enhanced when double pulse schemes were used. This enhancement was analyzed as a function of interpulse delays. Electron density and temperature evolutions were determined from time delays of 150 ns after the ablation plasma onset. Results are discussed in terms of the ablation rate. - Highlights: • A comparison of LIBS signal keeping constant the ablation fluence is performed. • Emission of ps laser ablation is up to four-fold enlarged compared with ns pulses. • Drilling ablation efficiency is 6 times larger with ps compared with ns pulses. • LIBS sensitivity with ps pulse ablation is equivalent to that of ns double pulse configuration.

  10. Sorbents based on xerogels of zirconium, aluminum and manganese oxyhydroxides

    National Research Council Canada - National Science Library

    R.V. Smotraiev; E.O. Sorochkina; А.V. Dzuba; Y.D. Galivets

    2016-01-01

    ...: The aim of this work is to determine the impact of aluminum and manganese ions additives on surface and sorption properties of zirconium oxyhydroxide based sorbents during their production process...

  11. Effects of electrode properties and fabricated pressure on Li ion diffusion and diffusion-induced stresses in cylindrical Li-ion batteries

    Science.gov (United States)

    Zhang, Tao; Guo, Zhansheng

    2014-03-01

    The effects of electrode properties and fabricated pressure on Li ion diffusion and diffusion-induced stress in a cylindrical Li-ion battery are studied. It is found that hydrostatic pressure or elastic modulus variation in the active layer have little effect on the distribution of Li ions for a higher diffusivity coefficient, but both can facilitate Li ion diffusion for a lower diffusivity coefficient. The elastic modulus variation has a significant effect on the distribution of stress and hydrostatic pressure can reduce the surface stress for the lower diffusivity coefficient. A higher charging rate causes a more transient response in the stress history, but a linear charging history is observed for slow charging rates. A higher charging rate would not inflict extra damage on the electrode for the higher diffusivity coefficient and the stress history becomes highly transient and charging rate dependent for the lower diffusivity coefficient. The effect of fabricated pressure can be neglected.

  12. Effects of size and concentration on diffusion-induced stress in lithium-ion batteries

    Science.gov (United States)

    Ma, Zengsheng; Gao, Xiang; Wang, Yan; Lu, Chunsheng

    2016-07-01

    Capacity fade of lithium-ion batteries induced by chemo-mechanical degradation during charge-discharge cycles is the bottleneck in design of high-performance batteries, especially high-capacity electrode materials. Stress generated due to diffusion-mechanical coupling in lithium-ion intercalation and deintercalation is accompanied by swelling, shrinking, and even micro-cracking. In this paper, we propose a theoretical model for a cylindrical nanowire electrode by combining the bond-order-length-strength and diffusion theories. It is shown that size and concentration have a significant influence on the stress fields in radial, hoop, and axial directions. This can explain why a smaller electrode with a huge volume change survives in the lithiation/delithiation process.

  13. UV-induced mutagenesis of oxidation activity of ferrous ion of Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An excellent strain named T. f6 was isolated and screened, the dose and other condition for the UV-induced mutagenesis were studied and the richened positive mutant m+ T. f6 was applied in the column leaching of copper-contain ing sulfides. The results show that T. f6 is characterized by rapid oxidation of ferrous ion and cupric sulfide, high tolerance of toxic ion and short generation time. The best mutagenic effectiveness can be obtained under the dose of low kill rate of UV and low temperature treatment, under which the best richened m+ T. f6 can be shortened 1.4h. It was shown by the column leaching of copper that the leaching rate can be enhanced by at least 11% compared with the original one by the mutants.

  14. X-ray spectra induced by slow highly charged Arq+ ions in collision with Nb surface

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The X-ray spectra of Nb surface induced by Arq+ (q =16,17) ions with the energy range from 10 to 20 keV/q were studied by the optical spectrum technology. The experimental results indicate that the multi-electron excitation occurred as a highly charged Ar16+ ion was neutralized below the metal surface. The K shell electron of Ar16+ was excited and then de-excited cascadly to emit K X-ray. The intensity of the X-ray emitted from K shell of the hollow Ar atom decreased with the increase of projectile kinetic energy. The intensity of the X-ray emitted from L shell of the target atom Nb increased with the increase of projectile kinetic energy. The X-ray yield of Ar17+ is three magnitude orders larger than that of Ar16+.

  15. Recent developments of ion beam induced luminescence: radiation hardness study of thin film plastic scintillators

    Science.gov (United States)

    Quaranta, Alberto

    2005-10-01

    Ion beam induced luminescence (IBIL) measurements have been performed on thin film scintillators based on polyvinyltoluene (PVT) and 6FDA-DAD and BPDA-3F polyimides with H+ (1.85 MeV) and He+ (1.8-2.2 MeV) ion beams. The radiation hardness of the undoped polymers has been verified to depend mainly on the deposited energy density, polyimides exhibiting a higher resistance with respect to PVT. In PVT a new fluorescence band, attributed to the radical precursors of the network crosslinking, has been observed. The efficiency of doped polymers degradates with a higher rate, depending on the dye intrinsic lability. At high radiation fluences, the relative efficiency to NE102 of doped polyimides scintillators increases owing to the intrinsic host improved resistance.

  16. Nanolesions induced by heavy ions in human tissues: Experimental and theoretical studies

    Directory of Open Access Journals (Sweden)

    Marcus Bleicher

    2012-07-01

    Full Text Available The biological effects of energetic heavy ions are attracting increasing interest for their applications in cancer therapy and protection against space radiation. The cascade of events leading to cell death or late effects starts from stochastic energy deposition on the nanometer scale and the corresponding lesions in biological molecules, primarily DNA. We have developed experimental techniques to visualize DNA nanolesions induced by heavy ions. Nanolesions appear in cells as “streaks” which can be visualized by using different DNA repair markers. We have studied the kinetics of repair of these “streaks” also with respect to the chromatin conformation. Initial steps in the modeling of the energy deposition patterns at the micrometer and nanometer scale were made with MCHIT and TRAX models, respectively.

  17. Molecular dynamics study of accelerated ion-induced shock waves in biological media

    CERN Document Server

    de Vera, Pablo; Currell, Fred J; Solov'yov, Andrey V

    2016-01-01

    We present a molecular dynamics study of the effects of carbon- and iron-ion induced shock waves in DNA duplexes in liquid water. We use the CHARMM force field implemented within the MBN Explorer simulation package to optimize and equilibrate DNA duplexes in liquid water boxes of different sizes and shapes. The translational and vibrational degrees of freedom of water molecules are excited according to the energy deposited by the ions and the subsequent shock waves in liquid water are simulated. The pressure waves generated are studied and compared with an analytical hydrodynamics model which serves as a benchmark for evaluating the suitability of the simulation boxes. The energy deposition in the DNA backbone bonds is also monitored as an estimation of biological damage, something which lies beyond the possibilities of the analytical model.

  18. A Structures for Lossless Ion Manipulations (SLIM) Module for Collision Induced Dissociation.

    Science.gov (United States)

    Webb, Ian K; Garimella, Sandilya V B; Norheim, Randolph V; Baker, Erin S; Ibrahim, Yehia M; Smith, Richard D

    2016-07-01

    A collision induced dissociation (CID) structure for lossless ion manipulations (SLIM) module is introduced and coupled to a quadrupole time-of-flight (QTOF) mass spectrometer. The SLIM CID module was mounted after an ion mobility (IM) drift tube to enable IM/CID/MS studies. The efficiency of CID was studied by using the model peptide leucine enkephalin. CID efficiencies (62%) compared favorably with other beam-type CID methods. Additionally, the SLIM CID module was used to fragment a mixture of nine peptides after IM separation. This work also represents the first application of SLIM in the 0.3 to 0.5 Torr pressure regime, an order of magnitude lower in pressure than previously studied. Graphical Abstract ᅟ.

  19. A Structures for Lossless Ion Manipulations (SLIM) Module for Collision Induced Dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Ian K.; Garimella, Venkata BS; Norheim, Randolph V.; Baker, Erin Shammel; Ibrahim, Yehia M.; Smith, Richard D.