Science.gov

Sample records for ion detachment processes

  1. Fluorine negative ion detachment kinetics

    NASA Technical Reports Server (NTRS)

    Burke, R. R.; Miller, W. J.; Gould, R. K.

    1971-01-01

    A study of the rate of F(-) detachment by O and H atoms via the reactions F(-) + O yields FO + e and F(-) + H yields FH+ e was undertaken using a drift tube to produce F(-) ions at various drift velocities and therefore different ion temperatures. Preliminary mobility measurements of F(-) ions in Ar were made, indicating that ion temperatures in the 300 K to 5000 K range could be achieved; however due to numerous difficulties experienced in obtaining a reliable F(-) ion source, the study could not be completed.

  2. Electron-impact detachment and dissociation of C4- ions

    NASA Astrophysics Data System (ADS)

    Le Padellec, A.; Rabilloud, F.; Pegg, D.; Neau, A.; Hellberg, F.; Thomas, R.; Schmidt, H. T.; Larsson, M.; Danared, H.; Källberg, A.; Andersson, K.; Hanstorp, D.

    2001-12-01

    CRYRING was used to study collision processes between an electron and a negative ion cluster C4-. The total detachment cross sections for the production of the neutral 4C, 3C, 2C, and C fragments were measured. The cross sections for pure detachment, and for detachment plus dissociation leading to the production of C3+C, 2C2, and C2+2C were extracted using a grid. It was found that the pure detachment process overwhelmingly dominates all other fragmentation processes. The threshold location for the detachment channel is found to be around 6.0 eV. Although the doubly charged negative ion C42- has received little previous attention, a defined near-threshold resonance observed in the detachment cross section curve, has been associated with the short-lived state C42- (0.7 fs lifetime).

  3. Electron collisional detachment processes for a 250 keV D- ion beam in a partially ionized hydrogen target

    NASA Astrophysics Data System (ADS)

    Savas, S. E.

    1981-08-01

    Neutral atom beams with energies above 200 keV are required for various purposes in magnetic fusion devices following TFTR, JET and MFTF-B. These beams are produced much more efficiently by electron detachment from negative ion beams than by electron capture by positive ions. The efficiency with which such neutral atoms can be produced by electron detachment in partially ionized hydrogen plasma neutralizers is investigated. Neutralization efficiencies for partially ionized hydrogen targets are calculated making use of cross sections. Previously calculated only for a pure electron gas neutralizer, this result was extended to conditions of arbitrary mixture of hydrogen gas and plasma using an averaging technique on the cross sections for the different target species. The effect of mixtures with contaminating gases and O2 and N2 on the neutralizer efficiency are also studied.

  4. Electron collisional detachment processes for a 250 2keV D(-) ion beam in a partially ionized hydrogen target

    NASA Astrophysics Data System (ADS)

    Savas, S. E.

    1980-09-01

    The efficiency with which neutral atoms can be produced by electron detachment in partially ionized hydrogen plasma neutralizers was investigated. Applications to magnetic fusion devices are discussed.

  5. Electron collisional detachment processes for a 250 keV D/sup -/ ion beam in a partially ionized hydrogen target

    SciTech Connect

    Savas, S.E.

    1980-09-01

    Neutral atom beams with energies above 200 keV may be required for various purposes in magnetic fusion devices following TFTR, JET and MFTF-B. These beams can be produced much more efficiently by electron detachment from negative ion beams than by electron capture by positive ions. We have investigated the efficiency with which such neutral atoms can be produced by electron detachment in partially ionized hydrogen plasma neutralizers.

  6. Observation of Plasma Recombination with the Negative Ions in Detached Plasma

    NASA Astrophysics Data System (ADS)

    Tonegawa, Akira; Shirota, Isao; Yoshida, Kenichi; Sugimoto, Tatunori; Kawamura, Kazutaka; Watanabe, Tsuguhiro; Ohyabu, Nobuyoshi; Takayama, Kazuo

    2000-10-01

    Detached divertors regimes are characterized by a low temperature (few eV) and high density plasma near the divertor plates. Recently, a new recombination process associated with excited hydrogen molecule, that is, molecular activated recombination (MAR), is expected to lead to an enhancement of the reduction of ion particle flux, and to modify the structure of detached recombining plasmas. In particular, negative ions play a key role in detached divertors regimes in charge exchange recombination of MAR. We present the experimental investigation of effects of the negative ions on detached plasma with MAR in the linear divertor plasma simulator, TPDSHEET-IV (Test Plasma produced by Directed current for SHEET plasma) device. The hydrogen plasma were generated with the hydrogen gas flow of 100 sccm at the discharge current of 50 A and the magnetic field of 0.7 kG. The negative ion density of hydrogen atom was measure by a probe-assisted laser photodetachment method. The reduction of the heat load to the target plate was clearly observed in hydrogen plasma with the hydrogen gas puff. At the same time, negative ions of hydrogen atom are localized in the region of cold electrons (2 eV) of the circumference of the sheet plasma. The charge exchange recombination rate of MAR is about 4 times of magnitude larger than three body recombination rate coefficients at this temperature. These experimental results suggest that the plasma recombination process comes from the negative ion of hydrogen atom.

  7. The detached haze layer in Titan's mesosphere: The formation process

    NASA Astrophysics Data System (ADS)

    Lavvas, P.; Yelle, R. V.; Vuitton, V.

    2008-09-01

    explanation for the Voyager detached haze fails by more than a factor of 50 for the detached layer at 520 km. The inefficiency of the above processes to provide enough mass flux to generate the detached layer along with the large mass flux retrieved by the observations [5,6] suggest that haze is formed in Titan's thermosphere by high-energy radical and ion chemistry. In this case the presence of the detached layer could be an optical illusion effect due to the increase of particles' size, along with the decrease of their settling velocity with decreasing altitude. In order to investigate this effect we used a microphysical model [15], which has been extended to describe both spherical and fractal particle growth [16]. We assume a gaussian production profile centered at 800 km and with a column mass production of 4.5 × 10-14 g cm-2 s-1. The particles grow as spheres or fractals depending on the fractal dimension, Df, (Df=2 for fractals and 3 for spheres). Using only spherical particle growth provides a good fit to the extinction observed by UVIS at 187.5 nm [3] above the detached haze layer, while the modeled extinction drops faster than the observed extinction at altitudes below the detached layer (Fig. 2). By setting the transition altitude of spherical to fractal growth at 510 km, the generated fractal particles provide an excellent fit to the observed extinction profile below the detached layer suggesting that the particles present there are indeed of fractal structure. At the same time, the transition from spheres to fractals aggregates, generates a well pronounced minimum in the total simulated extinction, which provides a very good fit to the observed detached haze layer extinction profile [3]. In addition, the calculated mass flux at 520 km is 3.1 × 10-14 g cm-2 s-1, which is within the limits defined by the optical analysis of the detached layer [5,6]. Finally, the calculated monomer size of the particles forming the fractal aggregates is 57 nm, is good agreement

  8. Electron detachment from negative ions in a short laser pulse

    SciTech Connect

    Shearer, S. F. C.; Smyth, M. C.; Gribakin, G. F.

    2011-09-15

    We present an efficient and accurate method to study electron detachment from negative ions by a few-cycle linearly polarized laser pulse. The adiabatic saddle-point method of Gribakin and Kuchiev [Phys. Rev. A 55, 3760 (1997)] is adapted to calculate the transition amplitude for a short laser pulse. Its application to a pulse with N optical cycles produces 2(N+1) saddle points in complex time, which form a characteristic 'smile.' Numerical calculations are performed for H{sup -} in a 5-cycle pulse with frequency 0.0043 a.u. and intensities of 10{sup 10}, 5x10{sup 10}, and 10{sup 11} W/cm{sup 2}, and for various carrier-envelope phases. We determine the spectrum of the photoelectrons as a function of both energy and emission angle, as well as the angle-integrated energy spectra and total detachment probabilities. Our calculations show that the dominant contribution to the transition amplitude is given by 5-6 central saddle points, which correspond to the strongest part of the pulse. We examine the dependence of the photoelectron angular distributions on the carrier-envelope phase and show that measuring such distributions can provide a way of determining this phase.

  9. Divertor detachment

    NASA Astrophysics Data System (ADS)

    Krasheninnikov, Sergei

    2015-11-01

    The heat exhaust is one of the main conceptual issues of magnetic fusion reactor. In a standard operational regime the large heat flux onto divertor target reaches unacceptable level in any foreseeable reactor design. However, about two decades ago so-called ``detached divertor'' regimes were found. They are characterized by reduced power and plasma flux on divertor targets and look as a promising solution for heat exhaust in future reactors. In particular, it is envisioned that ITER will operate in a partly detached divertor regime. However, even though divertor detachment was studied extensively for two decades, still there are some issues requiring a new look. Among them is the compatibility of detached divertor regime with a good core confinement. For example, ELMy H-mode exhibits a very good core confinement, but large ELMs can ``burn through'' detached divertor and release large amounts of energy on the targets. In addition, detached divertor regimes can be subject to thermal instabilities resulting in the MARFE formation, which, potentially, can cause disruption of the discharge. Finally, often inner and outer divertors detach at different plasma conditions, which can lead to core confinement degradation. Here we discuss basic physics of divertor detachment including different mechanisms of power and momentum loss (ionization, impurity and hydrogen radiation loss, ion-neutral collisions, recombination, and their synergistic effects) and evaluate the roles of different plasma processes in the reduction of the plasma flux; detachment stability; and an impact of ELMs on detachment. We also evaluate an impact of different magnetic and divertor geometries on detachment onset, stability, in- out- asymmetry, and tolerance to the ELMs. Supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award Number DE-DE-FG02-04ER54739 at UCSD.

  10. Shock detachment process on cones in hypervelocity flows

    NASA Astrophysics Data System (ADS)

    Leyva, Ivett Alejandra

    1999-11-01

    The shock detachment process on cones in hypervelocity flows is one of the most sensitive flows to relaxation effects. The critical angle for shock detachment under frozen conditions can be very different from the critical angle under chemical and thermal equilibrium. The rate of increase of the detachment distance with cone angle is also affected by the relaxation rate. The purpose of this study is to explain the effects of nonequilibrium on the shock detachment distance and its growth rate on cones in hypervelocity flows. The study consists of an experimental and a computational program. The experimental part has been carried out at Caltech's hypervelocity reflected shock tunnel. Six free-stream conditions were chosen, using both N2 and CO2 as test gases. The experimental data obtained are holographic interferograms, surface temperature, and pressure measurements. The code employed for the numerical simulations is a Navier-Stokes solver that can account for thermal and chemical nonequilibrium in axisymmetric flows. The data obtained for the shock detachment distance confirms a previous theoretical model that predicts the detachment distance will grow more slowly for relaxing flows than for frozen or equilibrium flows. This difference is due to the behavior of the sonic line inside the shock layer. Different growth rates result when the detachment distance is controlled by the diameter of the cone (frozen and equilibrium cases) than when it is controlled by the relaxation length (nonequilibrium flows). The behavior of the detachment distance from the frozen to equilibrium limits for a given cone half-angle and free-stream condition has also been studied. It was confirmed that the ratio of the detachment distance to the cone diameter is constant in the two extremes and rapidly switches from one value to the other for cone diameters of about 2 cm to 16 cm. The experimental interferograms are also compared with numerical ones in terms of the detachment distance, the

  11. General theory of electron detachment in negative ion collisions

    SciTech Connect

    Wang, T.S.

    1983-01-01

    In this thesis a general theory of electron detachment in slow collisions of negative ions with atoms is presented. The theory is based upon a semiclassical close-coupling framework, following the work of Taylor and Delos. The Schrodinger equation is reduced, under certain assumptions, to a non-denumerably infinite set of coupled equations. A new method for solving these equations is developed that is more general than the methods used by Taylor and Delos. A zero-order approximation of the solution is applied to the case of H-(D-) on Ne collisions, the results are compared with the experimental data, and good agreement between theory and experiment, particularly with regard to the isotope effect, is found. A first-order approximation of the solution is proved to be very close to the exact solution, and it is applied to the case of H-(D-) on He collisions. Quadratic and quartic approximations are used for the energy gap ..delta..(t) to calculate, among other things, the survival probability and electron energy spectrum. There are some interesting results of the electron energy spectrum which have not yet been observed in experiments.

  12. Racism: processes of detachment, dehumanization, and hatred.

    PubMed

    Dalal, Farhad

    2006-01-01

    The author looks at definitions of racism from the viewpoints of various theoretical frameworks, addressing the role of projection and other phenomena. Racism is then examined according to principles of psychoanalytic relational theory, attachment theory, and radical group analytic theory. Power relationships, the psychosocial process, a sense of us versus them, and the universal importance of a feeling of belonging are also taken into consideration. In examining the meaning of race, the author addresses the notions of black and white and their evolution over time, as well as the phenomenon of othering.

  13. Shock detachment process on cones in hypervelocity flows

    NASA Astrophysics Data System (ADS)

    Leyva, Ivett A.

    1999-11-01

    The shock detachment process on cones in hypervelocity flows is one of the most sensitive flows to relaxation effects. The critical angle for shock detachment under frozen conditions can be very different from the critical angle under chemical and thermal equilibrium. The rate of increase of the detachment distance with cone angle is also affected by the relaxation rate. The purpose of this study is to explain the effects of nonequilibrium on the shock detachment distance and its growth rate on cones in hypervelocity flows. The study consists of an experimental and a computational program. The experimental part has been carried out at Caltech's hypervelocity reflected shock tunnel (T5). Six different free-stream conditions have been chosen, four using N2 as the test gas and two using CO2. About 170 shots were performed on 24 cones. The cones range in diameter from 2 cm to 16 cm with half-angles varying from 55° to 75°. The experimental data obtained are holographic interferograms of every shot, and surface temperature and pressure measurements for the bigger cones. Extensive numerical simulations were made for the N2 flows and some were also made for the CO2 flows. The code employed is a Navier-Stokes solver that can account for thermal and chemical nonequilibrium in axisymmetric flows. The experimental and computational data obtained for the shock detachment distance confirms a previous theoretical model that predicts the detachment distance will grow more slowly for relaxing flows than for frozen or equilibrium flows. This difference is explained in terms of the behavior of the sonic line inside the shock layer. Different growth rates result when the detachment distance is controlled by the diameter of the cone (frozen and equilibrium cases) than when it is controlled by the extent of the relaxation zone inside the shock layer (nonequilibrium flows). The experimental data are also complemented with computational data to observe the behavior of the detachment

  14. Experimental studies on ion acceleration and stream line detachment in a diverging magnetic field

    PubMed Central

    Terasaka, K.; Yoshimura, S.; Ogiwara, K.; Aramaki, M.; Tanaka, M. Y.

    2010-01-01

    The flow structure of ions in a diverging magnetic field has been experimentally studied in an electron cyclotron resonance plasma. The flow velocity field of ions has been measured with directional Langmuir probes calibrated with the laser induced fluorescence spectroscopy. For low ion-temperature plasmas, it is concluded that the ion acceleration due to the axial electric field is important compared with that of gas dynamic effect. It has also been found that the detachment of ion stream line from the magnetic field line takes place when the parameter |fciLB∕Vi| becomes order unity, where fci, LB, and Vi are the ion cyclotron frequency, the characteristic scale length of magnetic field inhomogeneity, and the ion flow velocity, respectively. In the detachment region, a radial electric field is generated in the plasma and the ions move straight with the E×B rotation driven by the radial electric field. PMID:20838424

  15. Instability range of microsolvated multiply charged negative ions: prediction from detachment energy of stable hydrated clusters.

    PubMed

    Pathak, A K; Samanta, A K; Maity, D K; Mukherjee, T; Ghosh, S K

    2011-02-01

    We have presented a first-principle theory-based derivation of an exact expression for the solvent number-dependent electron-detachment energy of a solvated species in the thermodynamic limit. We also propose a generalized equation bridging the electron detachment energies for small and infinitely large clusters, thus providing a new route to calculate the ionization potential of a negatively charged ion from the electron-detachment energies of its stable hydrated clusters. Most importantly, it has the ability to predict the instability range of microhydrated anions. The calculated results for the ionization potential for a number of ions are found to be in good agreement with the available experimental results, and the predicted instability range for the doubly charged anions SO₄²⁻ and C₂O₄²⁻ is also consistent with experimental and ab initio results.

  16. Absence of the cusp in the single-electron detachment spectrum of the He{sup {minus}} ion

    SciTech Connect

    Vikor, L.; Sarkadi, L.

    1997-04-01

    The energy spectrum of electrons emitted in the single-electron detachment process in collisions of 200-keV He{sup {minus}} ions with He was measured. Taking advantage of the method of the 0{degree} electron spectroscopy carried out with good angular and energy resolution, the lines from the decay of the (1s2p2p{sup {prime}}) {sup 4}P{sup e} shape resonance of He{sup {minus}} were resolved, and the absence of the characteristic cusp peak in the double-differential cross section was established. {copyright} {ital 1997} {ital The American Physical Society}

  17. The Detached Bridgman Process: Application for the Growth of Low-Defect Germanium Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Croell, A.; Dold, P.; Szofran, F. R.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    During crystal growth in the vertical Bridgman process, both the melt and the growing crystal are in contact with the ampoule wall. The different thermal coefficients of expansion of the crystal and the ampoule wall can lead to stresses, crystal defects, and not rarely to cracks and/or polycrystalline growth in the crystal. The detached Bridgman process is characterized by the fact that the melt meniscus frees itself from the ampoule wall and the crystal can be grown without wall contact with the ampoule. After the effect of detachment was observed due to the reduced force of gravity during the early experiments under microgravity conditions, in the past few years the Bridgman process likewise has been successfully used to grow at least partially detached under 1g-condition. If the requirements for detaching the melt meniscus from the ampoule wall are not fulfilled by the material-specific parameters (like e.g. wetting behavior between ampoule and melt and the growth angle of the crystal), detachment can be obtained also by the imposition of suitable pressure ratios in the growth ampoule. In the context of this paper, the growth of germanium by the detached and vertical Bridgman processes in pyrolytic boron nitride crucibles will be reported, Typical gap widths between ampoule wall and detached grown crystals are approximately 10-50 microns. Compared to the crystals grown with wall contact, a reduction of the etch pit density of approximately two orders of magnitude could be obtained by growing with the detached process.

  18. The Detached Bridgman Process: Application for the Growth of Low-Defect Germanium Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Croell, A.; Dold, P.; Szofran, F. R.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    During crystal growth in the vertical Bridgman process, both the melt and the growing crystal are in contact with the ampoule wall. The different thermal coefficients of expansion of the crystal and the ampoule wall can lead to stresses, crystal defects, and not rarely to cracks and/or polycrystalline growth in the crystal. The detached Bridgman process is characterized by the fact that the melt meniscus frees itself from the ampoule wall and the crystal can be grown without wall contact with the ampoule. After the effect of detachment was observed due to the reduced force of gravity during the early experiments under microgravity conditions, in the past few years the Bridgman process likewise has been successfully used to grow at least partially detached under 1g-condition. If the requirements for detaching the melt meniscus from the ampoule wall are not fulfilled by the material-specific parameters (like e.g. wetting behavior between ampoule and melt and the growth angle of the crystal), detachment can be obtained also by the imposition of suitable pressure ratios in the growth ampoule. In the context of this paper, the growth of germanium by the detached and vertical Bridgman processes in pyrolytic boron nitride crucibles will be reported, Typical gap widths between ampoule wall and detached grown crystals are approximately 10-50 microns. Compared to the crystals grown with wall contact, a reduction of the etch pit density of approximately two orders of magnitude could be obtained by growing with the detached process.

  19. Numerical experiment to estimate the validity of negative ion diagnostic using photo-detachment combined with Langmuir probing

    SciTech Connect

    Oudini, N.; Sirse, N.; Ellingboe, A. R.; Benallal, R.; Taccogna, F.; Bendib, A.

    2015-07-15

    This paper presents a critical assessment of the theory of photo-detachment diagnostic method used to probe the negative ion density and electronegativity α = n{sub -}/n{sub e}. In this method, a laser pulse is used to photo-detach all negative ions located within the electropositive channel (laser spot region). The negative ion density is estimated based on the assumption that the increase of the current collected by an electrostatic probe biased positively to the plasma is a result of only the creation of photo-detached electrons. In parallel, the background electron density and temperature are considered as constants during this diagnostics. While the numerical experiments performed here show that the background electron density and temperature increase due to the formation of an electrostatic potential barrier around the electropositive channel. The time scale of potential barrier rise is about 2 ns, which is comparable to the time required to completely photo-detach the negative ions in the electropositive channel (∼3 ns). We find that neglecting the effect of the potential barrier on the background plasma leads to an erroneous determination of the negative ion density. Moreover, the background electron velocity distribution function within the electropositive channel is not Maxwellian. This is due to the acceleration of these electrons through the electrostatic potential barrier. In this work, the validity of the photo-detachment diagnostic assumptions is questioned and our results illustrate the weakness of these assumptions.

  20. Ion probe and fluid inclusion evidence for co-seismic fluid infiltration in a crustal detachment

    NASA Astrophysics Data System (ADS)

    Famin, V.; Hébert, R.; Philippot, P.; Jolivet, L.

    2005-10-01

    We have investigated the geochemical pattern of fluid infiltration in the extensional detachment of Tinos Island (Cyclades, Greece). Ion microprobe O-isotope analyses and fluid inclusion studies have been conducted in strain fringes developing around pyrite blasts in the mylonite of the shear zone. Micro-scale traverses in quartz and calcite fibres show that δ18O increases from 17-18 to 20-21‰ in 1 mm towards the blast, drops of 3‰ in ˜200 μm, then rises again in the direction of growth. δ18O variations are interpreted as transient influxes of exotic fluids into the shear zone between periods of closed system buffering by the host rock. Fluid inclusions trapped in the fibres show fluctuating salinities (0-4 wt% NaCl eq.) and densities that reflect drops of the pore pressure from lithostatic (λ=1) to hydrostatic (λ=0.4) values during fringe growth. Isotopic and microthermometric data are consistent with models of seismic pumping developed for compressive shear zones. We therefore suggest that co-seismic pore pressure variations developed suction forces sufficient to drive large-scale fluid migration in the Tinos detachment, as in convergent tectonic settings.

  1. Attachment and detachment processes as a typological index of relational systems.

    PubMed

    De Pascale, A; Gaetano, P; Gentili, N; Vella, G

    1992-01-01

    Attachment and detachment processes, as defined by modern attachment theories, place them as integrative between innate and acquired behaviors, like a regulatory system for every close relationship. As a consequence, family attachment styles, which proceed-throughout development-together with personal identity construction processes, stress the notion of relationship as a dialectical and interactive process, defining the irreducible duality of human experience, in which the personal individuality construction is linked, since the earliest phases of life, to the significant relationships. Dysfunctional patterns of attachment and detachment and self-construction processes interact in defining personal organizations one can observe in psychopathological situations; some clinical examples are proposed.

  2. Listeria monocytogenes attachment to and detachment from stainless steel surfaces in a simulated dairy processing environment.

    PubMed

    Poimenidou, Sofia; Belessi, Charalambia A; Giaouris, Efstathios D; Gounadaki, Antonia S; Nychas, George-John E; Skandamis, Panagiotis N

    2009-11-01

    The presence of pathogens in dairy products is often associated with contamination via bacteria attached to food-processing equipment, especially from areas where cleaning/sanitation is difficult. In this study, the attachment of Listeria monocytogenes on stainless steel (SS), followed by detachment and growth in foods, was evaluated under conditions simulating a dairy processing environment. Initially, SS coupons were immersed in milk, vanilla custard, and yogurt inoculated with the pathogen (10(7) CFU/ml or CFU/g) and incubated at two temperatures (5 and 20 degrees C) for 7 days. By the end of incubation, cells were mechanically detached from coupons and used to inoculate freshly pasteurized milk which was subsequently stored at 5 degrees C for 20 days. The suspended cells in all three products in which SS coupons were immersed were also used to inoculate freshly pasteurized milk (5 degrees C for 20 days). When SS coupons were immersed in milk, shorter lag phases were obtained for detached than for planktonically grown cells, regardless of the preincubation temperature (5 or 20 degrees C). The opposite was observed when custard incubated at 20 degrees C was used to prepare the two types of inocula. However, in this case, a significant increase in growth rate was also evident when the inoculum was derived from detached cells. In another parallel study, while L. monocytogenes was not detectable on SS coupons after 7 days of incubation (at 5 degrees C) in inoculated yogurt, marked detachment and growth were observed when these coupons were subsequently transferred and incubated at 5 degrees C in fresh milk or/and custard. Overall, the results obtained extend our knowledge on the risk related to contamination of dairy products with detached L. monocytogenes cells.

  3. Listeria monocytogenes Attachment to and Detachment from Stainless Steel Surfaces in a Simulated Dairy Processing Environment▿

    PubMed Central

    Poimenidou, Sofia; Belessi, Charalambia A.; Giaouris, Efstathios D.; Gounadaki, Antonia S.; Nychas, George-John E.; Skandamis, Panagiotis N.

    2009-01-01

    The presence of pathogens in dairy products is often associated with contamination via bacteria attached to food-processing equipment, especially from areas where cleaning/sanitation is difficult. In this study, the attachment of Listeria monocytogenes on stainless steel (SS), followed by detachment and growth in foods, was evaluated under conditions simulating a dairy processing environment. Initially, SS coupons were immersed in milk, vanilla custard, and yogurt inoculated with the pathogen (107 CFU/ml or CFU/g) and incubated at two temperatures (5 and 20°C) for 7 days. By the end of incubation, cells were mechanically detached from coupons and used to inoculate freshly pasteurized milk which was subsequently stored at 5°C for 20 days. The suspended cells in all three products in which SS coupons were immersed were also used to inoculate freshly pasteurized milk (5°C for 20 days). When SS coupons were immersed in milk, shorter lag phases were obtained for detached than for planktonically grown cells, regardless of the preincubation temperature (5 or 20°C). The opposite was observed when custard incubated at 20°C was used to prepare the two types of inocula. However, in this case, a significant increase in growth rate was also evident when the inoculum was derived from detached cells. In another parallel study, while L. monocytogenes was not detectable on SS coupons after 7 days of incubation (at 5°C) in inoculated yogurt, marked detachment and growth were observed when these coupons were subsequently transferred and incubated at 5°C in fresh milk or/and custard. Overall, the results obtained extend our knowledge on the risk related to contamination of dairy products with detached L. monocytogenes cells. PMID:19767476

  4. Role of pulsed winds on detachment of low salinity water from the Pearl River Plume: Upwelling and mixing processes

    NASA Astrophysics Data System (ADS)

    Chen, Zhaoyun; Pan, Jiayi; Jiang, Yuwu

    2016-04-01

    The detachment of low salinity water (LSW) from the Pearl River plume occurs frequently as revealed by in situ observations and satellite images, and plays an important role in cross-shore transport of the nutrient-rich plume water. In this study, the Regional Ocean Modeling System (ROMS) is used to simulate the LSW detachment process forced by realistic and idealized winds, and to explore its dynamical mechanisms. Modeling results show that the LSW detachment appears under a pulsed southwesterly wind, while tidal mixing modifies the size and salinity of the detached LSW. Strong pulsed wind causes the LSW to separate from the plume and move offshore quickly after the detachment. Under a pulsed northeasterly wind, however, the plume without separation of the LSW moves shoreward, indicating that the LSW detachment is sensitive to wind direction. In the plume region, upwelling develops under the forcing of the pulsed southwesterly wind, which transports high salinity bottom water to the surface layer, while the shear mixing in the upper layer further enhances the surface buoyancy flux, leading to appearance of high salinity water in the surface layer off the Pearl River estuary mouth, cutting off the eastward-spreading plume water, and resulting in the plume LSW detachment. Further analysis shows that the pulsed southwesterly wind induces positive local salinity change rate in the LSW detachment area. The pulsed upwelling-favorable wind with duration of 2-5 days is responsible for the detachment process.

  5. Growth Rate of Calcite Steps as a Function of Aqueous Calcium-to-Carbonate Ratio: Independent Attachment and Detachment of Calcium and Carbonate Ions

    SciTech Connect

    Stack, Andrew G; Grantham, Ms. Meg

    2010-01-01

    Growth rates of monolayer-height steps on the {1014} calcite surface have been measured as a function of the aqueous calcium-to-carbonate ratio. The maximum growth rates of the two common crystallographic orientations were found to deviate from the ideal stoichiometric ratio of 1:1, and dissolution features were observed under supersaturated solutions containing high calcium-to-carbonate ratios. To explain these phenomena, a theory is applied that treats the rates of attachment and detachment of aqueous calcium and carbonate ions separately. The resultant attachment rate constants are 1-3 orders of magnitude smaller than the water exchange rate of the constituent aqueous ions, suggesting that ligand-exchange processes may directly drive attachment. The broader implication is that the saturation state alone is not adequate to fully describe the rates of the multiple, independent reactions that occur on mineral surfaces under these conditions.

  6. Vitreous Detachment

    MedlinePlus

    ... of vision. Treatment How does vitreous detachment affect vision? Although a vitreous detachment does not threaten sight, ... hole or detached retina can lead to permanent vision loss in the affected eye. Those who experience ...

  7. Salix polaris growth responses to active layer detachment and solifluction processes in High Arctic.

    NASA Astrophysics Data System (ADS)

    Siekacz, Liliana

    2015-04-01

    The work is dedicated to demonstrate the potential of Salix polaris grow properties in the dendrogemorphologic image, analyzing periglacially induced slope processes in the high Arctic.. Observed anatomical and morphological plants responses to solifluction and active layer detachment processes are presented qualitatively and quantitatively as a summary of presented features frequency. The results are discussed against the background of the other research results in this field. The investigations was performed in Ebba valley, in the vicinity of Petunia Bay, northernmost part of Billefjorden in central Spitsbergen (Svalbard). Environmental conditions are characterized by annual precipitation sum lower than 200 mm (Hagen et al.,1993) and average summer temperature of about 5°C, with maximum daily temperatures rarely exceeding 10°C (Rachlewicz, 2009). Collected shrub material was prepared according to the methods presented by Schweingruber and Poschlod (2005). Thin (approx. 15-20μm) sections of the whole cross-section were prepared with a sledge microtome, stained with Safranine and Astra blue and finally permanently fixed on microslides with Canada balsam and dried. Snapshots were taken partially for each cross-section with digital camera (ColorView III, Olympus) connected to a microscope (Olympus BX41) and merged into one, high resolution image. After all, ring widths were measured in 3-4 radii in every single cross-section using ImageJ software. Analyzed plants revealed extremely harsh environmental conditions of their growth. Buchwał et al. (2013) provided quantitative data concerning missing rings and partially missing rings in shrubs growing on Ebba valley floor. Mean ring width at the level of 79μm represents one of the smallest values of yearly growth ever noted. The share of missing rings and partially missing rings was 11,2% and 13,6% respectively. Plants growing on Ebba valley slope indicate almost twice smaller values of ring width (41μm), and higher

  8. Model of detached plasmas

    SciTech Connect

    Yoshikawa, S.; Chance, M.

    1986-07-01

    Recently a tokamak plasma was observed in TFTR that was not limited by a limiter or a divertor. A model is proposed to explain this equilibrium, which is called a detached plasma. The model consists of (1) the core plasma where ohmic heating power is lost by anomalous heat conduction and (2) the shell plasma where the heat from the core plasma is radiated away by the atomic processes of impurity ions. A simple scaling law is proposed to test the validity of this model.

  9. Ion Beam Processing.

    DTIC Science & Technology

    1987-03-13

    ure are only those which had the greatest effect . Several features of this periodic chart are worth not- ing: i) some elements improve more than one...from nearly all the groups of the periodic table can have beneficial effects on a given property. iv) Ions which improve properties are highlighted...here, but ions which have deleterious effects may also be implanted which facilitates the study of mechanisms of wear and corrosion. v) Elements to

  10. High-Field Asymmetric-Waveform Ion Mobility Spectrometry and Electron Detachment Dissociation of Isobaric Mixtures of Glycosaminoglycans

    NASA Astrophysics Data System (ADS)

    Kailemia, Muchena J.; Park, Melvin; Kaplan, Desmond A.; Venot, Andre; Boons, Geert-Jan; Li, Lingyun; Linhardt, Robert J.; Amster, I. Jonathan

    2013-11-01

    High-field asymmetric waveform ion mobility spectrometry (FAIMS) is shown to be capable of resolving isomeric and isobaric glycosaminoglycan negative ions and to have great utility for the analysis of this class of molecules when combined with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and tandem mass spectrometry. Electron detachment dissociation (EDD) and other ion activation methods for tandem mass spectrometry can be used to determine the sites of labile sulfate modifications and for assigning the stereochemistry of hexuronic acid residues of glycosaminoglycans (GAGs). However, mixtures with overlapping mass-to-charge values present a challenge, as their precursor species cannot be resolved by a mass analyzer prior to ion activation. FAIMS is shown to resolve two types of mass-to-charge overlaps. A mixture of chondroitin sulfate A (CSA) oligomers with 4-10 saccharides units produces ions of a single mass-to-charge by electrospray ionization, as the charge state increases in direct proportion to the degree of polymerization for these sulfated carbohydrates. FAIMS is shown to resolve the overlapping charge. A more challenging type of mass-to-charge overlap occurs for mixtures of diastereomers. FAIMS is shown to separate two sets of epimeric GAG tetramers. For the epimer pairs, the complexity of the separation is reduced when the reducing end is alkylated, suggesting that anomers are also resolved by FAIMS. The resolved components were activated by EDD and the fragment ions were analyzed by FTICR-MS. The resulting tandem mass spectra were able to distinguish the two epimers from each other.

  11. High-Field Asymmetric-Waveform Ion Mobility Spectrometry and Electron Detachment Dissociation of Isobaric Mixtures of Glycosaminoglycans

    PubMed Central

    Kailemia, Muchena J.; Park, Melvin; Kaplan, Desmond A.; Venot, Andre; Boons, Geert-Jan; Li, Lingyun; Linhardt, Robert J.; Amster, I. Jonathan

    2014-01-01

    High-field asymmetric waveform ion mobility spectrometry (FAIMS) is shown to be capable of resolving isomeric and isobaric glycosaminoglycan negative ions, and to have great utility for the analysis of this class of molecules when combined with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and tandem mass spectrometry. Electron detachment dissociation (EDD) and other ion activation methods for tandem mass spectrometry can be used to determine the sites of labile sulfate modifications and for assigning the stereochemistry of hexuronic acid residues of GAGs. However, mixtures with overlapping mass-to-charge values present a challenge, as their precursor species cannot be resolved by a mass analyzer prior to ion activation. FAIMS is shown to resolve two types of mass-to-charge overlaps. A mixture of chondroitin sulfate A (CSA) oligomers with 4–10 saccharides units produces ions of a single mass-to-charge by electrospray ionization, as the charge state increases in direct proportion to the degree of polymerization for these sulfated carbohydrates. FAIMS is shown to resolve the overlapping charge. A more challenging type of mass-to-charge overlap occurs for mixtures of diastereomers. FAIMS is shown to separate two sets of epimeric GAG tetramers. For the epimer pairs, the complexity of the separation is reduced when the reducing end is alkylated, suggesting that anomers are also resolved by FAIMS. The resolved components were activated by EDD and the fragment ions were analyzed by FTICR-MS. The resulting tandem mass spectra were able to distinguish the two epimers from each other. PMID:24254578

  12. Dynamics of slab detachment

    NASA Astrophysics Data System (ADS)

    Duretz, T.; Schmalholz, S. M.; Gerya, T. V.

    2012-04-01

    Our study investigates the dynamics of slab detachment and evaluates the amount of time necessary for slabs to detach. We combine both the results of two-dimensional numerical modeling with the prediction of a one-dimensional analytical solution for viscous necking under gravity. This tidy suggest that the dominant deformation mechanisms leading to slab detachment is viscous necking, independently of the depth of slab detachment. Localised simple shear may also occur when the slab dip is moderate, especially in the colder parts of the slab. Brittle fracturing, or breaking, plays a minor role during the slab detachment process. 2D thermo-mechanical simulations indicate that the duration of slab detachment is short (< 4 Ma) and can occur in less than 0.5 Ma. No simple correlation between the slab detachment depth and duration was found. Our results suggest that deep slab detachments (> 250 km) can also occur within a short time (< 1 Ma). On the other hand, slab detachments taking place between 35 and 250 km depth may last less than 2 Ma. This aspect has implications for geodynamic interpretations using slab detachment as explanation for processes such as melting, exhumation or surface uplift.

  13. Effects of Near Soil Surface Characteristics on the Soil Detachment Process in a Chronological Series of Vegetation Restoration

    NASA Astrophysics Data System (ADS)

    Wang, Bing

    2017-04-01

    The effects of near soil surface characteristics on the soil detachment process might be different at different stages of vegetation restoration. This study was performed to investigate the effects of the near soil surface factors of plant litter, biological soil crusts (BSCs), dead roots and live roots on the soil detachment process by overland flow at different stages of restoration. Soil samples (1 m long, 0.1 m wide, and 0.05 m high) under four treatment conditions were collected from 1-yr-old and 24-yr-old natural grasslands and subjected to flow scouring under five different shear stresses ranging from 5.3 to 14.6 Pa. The results indicated that the effects of near soil surface characteristics on soil detachment were substantial during the process of vegetation restoration. The total reduction in the soil detachment capacity of the 1-yr-old grassland was 98.1%, and of this total, 7.9%, 30.0% and 60.2% was attributed to the litter, BSCs and plant roots, respectively. In the 24-yr-old grassland, the soil detachment capacity decreased by 99.0%, of which 13.2%, 23.5% and 62.3% was caused by the litter, BSCs and plant roots, respectively. Combined with the previously published data of a 7-yr-old grassland, the influence of plant litter on soil detachment was demonstrated to increase with restoration time, but soil detachment was also affected by the litter type and composition. The role of BSCs was greater than that of plant litter in reducing soil detachment during the early stages of vegetation recovery. However, its contribution weakened with time since restoration. The influence of plant roots accounted for at least half or up to two-thirds of the total near soil surface factors, of which more than 72.6% was attributed to the physical binding effects of the roots. The chemical bonding effect of the roots increased with time since restoration and was greater than the effect of the litter on soil detachment in the late stages of vegetation restoration. The

  14. Effects of surface processes on multilayer detachment folding: a numerical approach

    NASA Astrophysics Data System (ADS)

    Collignon, M.; May, D.; Kaus, B.; Fernandez, N.

    2013-12-01

    Over the past decades, the interaction between surface processes and development of mountain belts has been extensively studied. While syntectonic sedimentation appears to control the external development of the fold-and-thrust belts, erosion strongly influences the evolution of internal regions within mountain belts. The effects of surface processes on brittle deformation have been thoroughly studied using analogue and numerical models of accretionary wedges, however, most of the numerical studies used a 2D model of deformation and/or a simple formulation for the surface processes, where both sedimentation and erosion are rarely present together. Coupled analogue models of deformation and surface processes are challenging, due to material and scaling issues, and often only reproduce two end-member cases (no erosion vs very strong erosion, where all the material is removed), but fail to investigate the transitional cases. In contrast, interactions between surface processes and ductile deformation (e.g. multilayer detachment folding) have been poorly investigated. Thin-skinned fold and thrust belts are seen as the result of compressional deformation of a sediment pile over a weak layer acting as a décollement level. The resulting surface expression has often been interpreted, based on geometrical criteria in terms of fault bend folds, propagation folds and/or detachment folds. A few analogue studies have demonstrated that fold morphology can be influenced by erosion rates or preferential localization of sedimentation, and additionally, that the fold growth can be stopped by increasing the supply of sediments. Here we aim to numerically investigate the effects of surface processes and multilayer folding in three dimensions. For this purpose, we have developed a finite-element based landscape evolution model (both erosion and sedimentation) using PETSc, and coupled it to the 3D mechanical code LaMEM. The landscape evolution model uses a non-linear diffusion

  15. Retinal detachment.

    PubMed

    Cavallerano, A A

    1992-01-01

    Retinal detachment is a separation of the neurosensory retina from the retinal pigment epithelium. Most retinal detachments are rhegmatogenous, and identification of risk factors and predisposing lesions are important aspects of patient management. Retinal detachment is relatively rare, but can pose a significant threat to vision if there is macular involvement. Prompt diagnosis combined with patient education and appropriate intervention often can avert irrevocable visual impairment. This paper presents an overview of the categories of retinal detachment, discusses the pathogenesis of the various types of detachment, and provides recommendations for primary care of patients with predisposing factors and high-risk characteristics.

  16. Modeling Detached Plasmas in DIII-D

    NASA Astrophysics Data System (ADS)

    Porter, Gary D.; Rognlien, T. D.; Rensink, M. E.; DIII-D Team

    1996-11-01

    The ITER divertor design relies on operation of the machine with a detached divertor plasma as a means of reducing the divertor heat load to manageable levels. This operating mode has been seen on all of the world's diverted tokamaks, and is characterized by very low plate temperatures and ion currents. Experimental results on DIII-D have shown the plate electron temperature is between 1 and 2 eV. We describe the results of modeling these detached plasmas with the UEDGE code in this paper. Plasma detachment can be achieved in a variety of ways in the code as well as in experiment. Simulations indicate the detachment process occurs in two steps: a thermal collapse in which the plate temperature drops to 1 to 2 eV, followed by a decrease in the plate ion current. When the low temperature region extends off the plate, parallel momentum of the plasma is reduced by ion/neutral interactions. The plate ion current decreases when the parallel momentum is reduced sufficiently to permit volume recombination processes to compete with ion flow to the plate.

  17. A periodic freshwater patch detachment process from the Block Island Sound estuarine plume

    NASA Astrophysics Data System (ADS)

    Liu, Qianqian; Rothstein, Lewis M.; Luo, Yiyong

    2017-01-01

    Previous observations suggest periodic freshwater patches separating from the Block Island Sound (BIS) estuarine plume. In this study, the dynamics of the separation process is investigated through a series of numerical experiments using the Regional Ocean Modeling System (ROMS). In addition, we explore the seasonal variability of the freshwater patches and their response to river discharge and ambient current. The model results indicate that episodic freshwater patches are triggered by small changes in tidal currents over the spring-neap tidal cycle. The spring-neap variation in tidal currents causes significant, monthly fluctuations in turbulent mixing and vertical stratification in BIS, modulating the freshwater discharge thereby generating episodic freshwater patches that move both downstream along the southern shore of Long Island and toward Rhode Island Sound (RIS). The realistically configured model shows that the freshwater patches experience strong seasonal variability. They are largest in spring when the river discharge peaks, and smallest in summer due to the weak river discharge and a robust upstream ambient current from RIS. According to the analysis of the freshwater transport out of BIS, we conclude that such detachment occurs at tidal mixing fronts.

  18. Ion funnel ion trap and process

    DOEpatents

    Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

    2011-02-15

    An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

  19. Plasma detachment in linear devices

    NASA Astrophysics Data System (ADS)

    Ohno, N.

    2017-03-01

    Plasma detachment research in linear devices, sometimes called divertor plasma simulators, is reviewed. Pioneering works exploring the concept of plasma detachment were conducted in linear devices. Linear devices have contributed greatly to the basic understanding of plasma detachment such as volume plasma recombination processes, detached plasma structure associated with particle and energy transport, and other related issues including enhancement of convective plasma transport, dynamic response of plasma detachment, plasma flow reversal, and magnetic field effect. The importance of plasma detachment research using linear devices will be highlighted aimed at the design of future DEMO.

  20. A micromechanical approach of suffusion based on a length scale analysis of the grain detachment and grain transport processes.

    NASA Astrophysics Data System (ADS)

    Wautier, Antoine; Bonelli, Stéphane; Nicot, François

    2017-06-01

    Suffusion is the selective erosion of the finest particles of a soil subjected to an internal flow. Among the four types of internal erosion and piping identified today, suffusion is the least understood. Indeed, there is a lack of micromechanical approaches for identifying the critical microstructural parameters responsible for this process. Based on a discrete element modeling of non cohesive granular assemblies, specific micromechanical tools are developed in a unified framework to account for the two first steps of suffusion, namely the grain detachment and the grain transport processes. Thanks to the use of an enhanced force chain definition and autocorrelation functions the typical lengths scales associated with grain detachment are characterized. From the definition of transport paths based on a graph description of the pore space the typical lengths scales associated with grain transport are recovered. For a uniform grain size distribution, a separation of scales between these two processes exists for the finest particles of a soil

  1. Energy and angular distributions of detached electrons in a solvable model of ion-atom collisions

    SciTech Connect

    Macek, J.H.; Ovchinnikov, S.Y. |; Solovev, E.A.

    1999-08-01

    Electron energy and angular distributions are computed for a model of atom{endash}negative-ion collisions. In this model, electron-atom interactions are represented by zero-range potentials in an approximation where two identical atoms move along straight-line classical trajectories in head-on collisions. Analytic expressions for the ionization amplitudes are interpreted in terms of Sturmian eigenvalues and eigenfunctions. At high velocity, the computed distributions exhibit direct excitation and continuum capture cusps in addition to the binary encounter ridge. At low velocities, a single feature corresponding to an electron distribution centered midway between the target and projectile emerges. For initial conditions corresponding to gerade symmetry a single broad peak appears, while for ungerade symmetry there is a node at the midpoint so that the peak splits into two parts. It is confirmed that the advanced adiabatic approximation gives an accurate description of the ungerade distribution at low and intermediate velocities. {copyright} {ital 1999} {ital The American Physical Society}

  2. Energy and angular distributions of detached electrons in a solvable model of ion-atom collisions

    SciTech Connect

    Macek, J.H.; Ovchinnikov, S.Y. Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 ); Solovev, E.A. )

    1999-08-01

    Electron energy and angular distributions are computed for a model of atom[endash]negative-ion collisions. In this model, electron-atom interactions are represented by zero-range potentials in an approximation where two identical atoms move along straight-line classical trajectories in head-on collisions. Analytic expressions for the ionization amplitudes are interpreted in terms of Sturmian eigenvalues and eigenfunctions. At high velocity, the computed distributions exhibit direct excitation and continuum capture cusps in addition to the binary encounter ridge. At low velocities, a single feature corresponding to an electron distribution centered midway between the target and projectile emerges. For initial conditions corresponding to gerade symmetry a single broad peak appears, while for ungerade symmetry there is a node at the midpoint so that the peak splits into two parts. It is confirmed that the advanced adiabatic approximation gives an accurate description of the ungerade distribution at low and intermediate velocities. [copyright] [ital 1999] [ital The American Physical Society

  3. Retinal detachment

    MedlinePlus

    ... of the retina responsible for sharp, detailed vision. Symptoms Symptoms of detached retina can include: Bright flashes of ... right away or within a short time after diagnosis. Some types of surgery can be done in ...

  4. Retinal Detachment

    MedlinePlus

    ... immediately. Treatment How is retinal detachment treated? Small holes and tears are treated with laser surgery or ... laser surgery tiny burns are made around the hole to “weld” the retina back into place. Cryopexy ...

  5. Retinal Detachment

    MedlinePlus

    The retina is a layer of tissue in the back of your eye that senses light and sends images ... for reading, driving, and seeing fine detail. A retinal detachment lifts or pulls the retina from its ...

  6. Theoretical investigation of electron transfer and detachment processes in low energy H- + Li and Li- + H collisions

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Lin, X. H.; Yan, B.; Wang, J. G.; Janev, R. K.

    2016-02-01

    The charge exchange and collisional detachment processes in H- + Li and Li- + H collisions have been studied by using the quantal molecular orbital close-coupling (QMOCC) method in the energy ranges of about 0.12-1000 eV u-1 and 0.1 meV-1000 eV, respectively, and the inelastic collision cross sections and rate coefficients have been computed and presented. It is found that the electron transfer process in the H- + Li and Li- + H collisions is due to the Demkov coupling between the 12Σ+ and 22Σ+ states at internuclear distances of about 15a0. The collisional electron detachment in the considered collision system is due to the excitation of the remaining six states, which are all unstable against autodetachment. These states are populated through a series of Landau-Zener couplings of the 22Σ+ state with upper 2Σ+ states and by the rotational 2Σ+-2Π couplings at small internuclear distances. The cross sections for electron transfer in H- + Li and Li- + H collisions in the energy range of 10-1000 eV u-1 attain values in the range of 10-16-10-15 cm2 (reaching their maximum values of about 5 × 10-15 cm2 at 500-600 eV u-1), while the values of the corresponding electron detachment cross sections in this energy range attain generally smaller values.

  7. Retinal detachment

    PubMed Central

    2010-01-01

    Introduction Rhegmatogenous retinal detachment (RRD) is the most common form of retinal detachment, where a retinal "break" allows the ingress of fluid from the vitreous cavity to the subretinal space, resulting in retinal separation. It occurs in about 1 in 10,000 people a year. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent progression from retinal breaks or lattice degeneration to retinal detachment? What are the effects of different surgical interventions in people with rhegmatogenous retinal detachment? What are the effects of interventions to treat proliferative vitreoretinopathy occurring as a complication of retinal detachment or previous treatment for retinal detachment? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 21 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: corticosteroids, cryotherapy, daunorubicin, fluorouracil plus low molecular weight heparin, laser photocoagulation, pneumatic retinopexy, scleral buckling, short-acting or long-acting gas tamponade, silicone oil tamponade, and vitrectomy. PMID:21406128

  8. Retinal detachment

    PubMed Central

    2009-01-01

    Introduction Rhegmatogenous retinal detachment (RRD) is the most common form of retinal detachment, where a retinal "break" allows the ingress of fluid from the vitreous cavity to the subretinal space, resulting in retinal separation. It occurs in about 1 in 10,000 people a year. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent progression from retinal breaks or lattice degeneration to retinal detachment? What are the effects of different surgical interventions in people with rhegmatogenous retinal detachment? What are the effects of interventions to treat proliferative vitreoretinopathy occurring as a complication of retinal detachment or previous treatment for retinal detachment? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2009 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 20 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: corticosteroids; cryotherapy; daunorubicin; fluorouracil plus low-molecular-weight heparin; laser photocoagulation; pneumatic retinopexy; scleral buckling; short-acting or long-acting gas tamponade; silicone oil tamponade; and vitrectomy. PMID:19450333

  9. Bacteriophage PRD1 batch experiments to study attachment, detachment and inactivation processes

    NASA Astrophysics Data System (ADS)

    Sadeghi, Gholamreza; Schijven, Jack F.; Behrends, Thilo; Hassanizadeh, S. Majid; van Genuchten, Martinus Th.

    2013-09-01

    Knowledge of virus removal in subsurface environments is pivotal for assessing the risk of viral contamination of water resources and developing appropriate protection measures. Columns packed with sand are frequently used to quantify attachment, detachment and inactivation rates of viruses. Since column transport experiments are very laborious, a common alternative is to perform batch experiments where usually one or two measurements are done assuming equilibrium is reached. It is also possible to perform kinetic batch experiments. In that case, however, it is necessary to monitor changes in the concentration with time. This means that kinetic batch experiments will be almost as laborious as column experiments. Moreover, attachment and detachment rate coefficients derived from batch experiments may differ from those determined using column experiments. The aim of this study was to determine the utility of kinetic batch experiments and investigate the effects of different designs of the batch experiments on estimated attachment, detachment and inactivation rate coefficients. The experiments involved various combinations of container size, sand-water ratio, and mixing method (i.e., rolling or tumbling by pivoting the tubes around their horizontal or vertical axes, respectively). Batch experiments were conducted with clean quartz sand, water at pH 7 and ionic strength of 20 mM, and using the bacteriophage PRD1 as a model virus. Values of attachment, detachment and inactivation rate coefficients were found by fitting an analytical solution of the kinetic model equations to the data. Attachment rate coefficients were found to be systematically higher under tumbling than under rolling conditions because of better mixing and more efficient contact of phages with the surfaces of the sand grains. In both mixing methods, more sand in the container yielded higher attachment rate coefficients. A linear increase in the detachment rate coefficient was observed with increased

  10. Impurity ion flow and temperature measured in a detached divertor with externally applied non-axisymmetric fields on DIII-D

    DOE PAGES

    Briesemeister, A. R.; Isler, R. C.; Allen, S. L.; ...

    2014-11-15

    Externally applied non-axisymmetric magnetic fields are shown to have little effect on the impurity ion flow velocity and temperature as measured by the multichord divertor spectrometer in the DIII-D divertor for both attached and detached conditions. These experiments were performed in H-mode plasmas with the grad-B drift toward the target plates, with and without n = 3 resonant magnetic perturbations (RMPs). The flow velocity in the divertor is shown to change by as much as 30% when deuterium gas puffing is used to create detachment of the divertor plasma. No measurable changes in the C III flow were observed inmore » response to the RMP fields for the conditions used in this work. Images of the C III emission are used along with divertor Thomson scattering to show that the local electron and C III temperatures are equilibrated for the conditions shown.« less

  11. Impurity ion flow and temperature measured in a detached divertor with externally applied non-axisymmetric fields on DIII-D

    SciTech Connect

    Briesemeister, A. R.; Isler, R. C.; Allen, S. L.; Ahn, J. -W.; McLean, A. G.; Unterberg, E. A.; Hillis, D. L.; Fenstermacher, M. E.; Meyer, W. H.

    2014-11-15

    In this study, externally applied non-axisymmetric magnetic fields are shown to have little effect on the impurity ion flow velocity and temperature as measured by the multichord divertor spectrometer in the DIII-D divertor for both attached and detached conditions. These experiments were performed in H-mode plasmas with the grad-B drift toward the target plates, with and without n = 3 resonant magnetic perturbations (RMPs). The flow velocity in the divertor is shown to change by as much as 30% when deuterium gas puffing is used to create detachment of the divertor plasma. No measurable changes in the C III flow were observed in response to the RMP fields for the conditions used in this work. Images of the C III emission are used along with divertor Thomson scattering to show that the local electron and C III temperatures are equilibrated for the conditions shown.

  12. Impurity ion flow and temperature measured in a detached divertor with externally applied non-axisymmetric fields on DIII-D

    NASA Astrophysics Data System (ADS)

    Briesemeister, A. R.; Isler, R. C.; Allen, S. L.; Ahn, J.-W.; McLean, A. G.; Unterberg, E. A.; Hillis, D. L.; Fenstermacher, M. E.; Meyer, W. H.

    2015-08-01

    Externally applied non-axisymmetric magnetic fields are shown to have little effect on the impurity ion flow velocity and temperature as measured by the multichord divertor spectrometer in the DIII-D divertor for both attached and detached conditions. These experiments were performed in H-mode plasmas with the grad-B drift toward the target plates, with and without n = 3 resonant magnetic perturbations (RMPs). The flow velocity in the divertor is shown to change by as much as 30% when deuterium gas puffing is used to create detachment of the divertor plasma. No measurable changes in the C III flow were observed in response to the RMP fields for the conditions used in this work. Images of the C III emission are used along with divertor Thomson scattering to show that the local electron and C III temperatures are equilibrated for the conditions shown.

  13. Retinal detachment

    PubMed Central

    2014-01-01

    Introduction Rhegmatogenous retinal detachment (RRD) is the most common form of retinal detachment, where a retinal 'break' allows the ingress of fluid from the vitreous cavity to the subretinal space, resulting in retinal separation. It occurs in about 1 in 10,000 people a year. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of different surgical interventions in people with rhegmatogenous retinal detachment? What are the effects of interventions to treat proliferative vitreoretinopathy occurring as a complication of retinal detachment or previous treatment for retinal detachment? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2013 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 14 studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: corticosteroids, daunorubicin, fluorouracil plus low molecular weight heparin, pneumatic retinopexy, scleral buckling, short-acting or long-acting gas tamponade, silicone oil tamponade, and vitrectomy. PMID:24807890

  14. Negative ion formation processes: A general review

    SciTech Connect

    Alton, G.D.

    1990-01-01

    The principal negative ion formation processes will be briefly reviewed. Primary emphasis will be placed on the more efficient and universal processes of charge transfer and secondary ion formation through non-thermodynamic surface ionization. 86 refs., 20 figs.

  15. An Apparatus for the Measurement of Various Scattering Processes in Intermediate Energy, Ion - Atom Collisions

    SciTech Connect

    Kvale, T. J.; Seely, D. G.

    1998-07-01

    This paper summarizes the main features of an apparatus constructed at the University of Toledo for the study of various scattering processes in intermediate energy, ion - atom collisions. The main purpose of this facility is to provide experimental data which serve as benchmarks to test current scattering theories for those processes. Recent measurements of single electron detachment (SED) and double electron detachment (DED) total cross sections for 5-50 keV H{sup -} ions incident on noble gases and for 10-50 keV H{sup -} ions incident on CH{sub 4} molecules were conducted in this laboratory. As a result of an analysis of the scattered beam growth curves, information about other charge-changing cross sections in the hydrogen-atom (molecule) collision systems were obtain, as well.

  16. Metasomatic fault weakening processes in the Moresby Seamount detachment, Woodlark Basin (offshore Papua New Guinea)

    NASA Astrophysics Data System (ADS)

    Speckbacher, R.; Behrmann, J. H.; Stipp, M.; Nagel, T. J.; Mahlke, J.; Devey, C. W.

    2011-12-01

    The Woodlark Basin (east of Papua New Guinea) is a classic example of an active transition from continental rifting to seafloor spreading. The submerged Moresby Seamount detachment (MSD) is arguably the best exposed active detachment fault in the world, and is the candidate structure for future crustal breakup and ocean floor spreading. Nearly three decades of debate have failed to explain how initial crustal weakening and sustained operation of detachment faults occurs. While high fluid pressure has been shown to maintain faulting at low differential stress in the brittle regime, other effects have to induce weakening at greater depth allowing a transition from cataclastic (brittle) to plastic deformation. We suggest that a relative enrichment in "weak" minerals, i.e. calcite and quartz, plays a key role for mylonitization along the MSD. Based on a suite of protoliths, mylonites and cataclasites dredged from the MSD we show that deformation is accompanied by metasomatic changes, which are driven by a hydrothermal system connected to the fault zone. Immobile elements (essentially Zr, Y, and P) of the gabbroic protoliths and fault rocks provide a reference frame for the calculation of material gains and losses during syntectonic alteration. Si, Ca, and to a lesser extent K and Mn were syntectonically enriched throughout the MSD, while there is depletion in Fe, Ti, Mg, and Al. These metasomatic changes are interpreted to be associated with upward flow of mid-crustal fluids along the MSD. Mass balance calculations show that up to 56 % mass gain occurred during the formation of μm to cm-thick quartz and calcite veins and intermittent deformation. The enrichment in quartz and calcite allows a switch from dominant brittle to dominant plastic deformation. The resulting mylonites operate as relatively weak fault rocks at low differential stress. Maximum flow stress is approximately 72 +23/-10 MPa, inferred from the dynamically recrystallized quartz grain size. The MSD

  17. Adhesion Failure at 180 000 Frames per Second: Direct Observation of the Detachment Process of a Mushroom-Shaped Adhesive

    NASA Astrophysics Data System (ADS)

    Heepe, Lars; Kovalev, Alexander E.; Filippov, Alexander E.; Gorb, Stanislav N.

    2013-09-01

    Nature has successfully evolved the mushroom-shaped contact geometry in many organisms in order to solve the attachment problem. We studied the detachment process of individual bioinspired artificial mushroom-shaped adhesive microstructures (MSAMSs) resolving the failure dynamics at high spatiotemporal resolution. The experimental data provide strong evidence for a homogeneous stress distribution in MSAMS, which was recently proposed. Our results allow us to explain the advantage of such contact geometry and provide a suggestion for the widely observed mushroom-shaped contact geometry.

  18. Dielectric breakdown properties of N{sub 2}–O{sub 2} mixtures by considering electron detachments from negative ions

    SciTech Connect

    Zhao, Hu Lin, Hui

    2016-07-15

    The paper analyzes the dielectric breakdown properties of N{sub 2}–O{sub 2} mixtures at different O{sub 2} concentrations and gas pressures, taking into account electron detachments from negative ions. The reduced effective ionization coefficients α(eff)/N in N{sub 2}–O{sub 2} mixtures at different O{sub 2} concentrations and gas pressures were calculated and analyzed, by considering electron detachments. The critical reduced electric fields (E/N){sub cr} and the critical electron temperature T{sub b} were then determined. The result indicates a clear enhancement of α(eff)/N by collisional detachments, which causes a reduction in the (E/N){sub cr}. In addition, a synergistic effect in the N{sub 2}–O{sub 2} mixture was also observed in both (E/N){sub cr} and T{sub b}. The value of T{sub b} was decreased by the increase of pd product, however, T{sub b} tended to be constant at relatively high pd products.

  19. Orthogonal ion injection apparatus and process

    DOEpatents

    Kurulugama, Ruwan T; Belov, Mikhail E

    2014-04-15

    An orthogonal ion injection apparatus and process are described in which ions are directly injected into an ion guide orthogonal to the ion guide axis through an inlet opening located on a side of the ion guide. The end of the heated capillary is placed inside the ion guide such that the ions are directly injected into DC and RF fields inside the ion guide, which efficiently confines ions inside the ion guide. Liquid droplets created by the ionization source that are carried through the capillary into the ion guide are removed from the ion guide by a strong directional gas flow through an inlet opening on the opposite side of the ion guide. Strong DC and RF fields divert ions into the ion guide. In-guide orthogonal injection yields a noise level that is a factor of 1.5 to 2 lower than conventional inline injection known in the art. Signal intensities for low m/z ions are greater compared to convention inline injection under the same processing conditions.

  20. Stupidity in the analytic field: Vicissitudes of the detachment process in adolescence.

    PubMed

    Cassorla, Roosevelt M S

    2017-04-01

    This paper has the objective of broadening the understanding of technical aspects in working with adolescents who defend themselves against detachment from infantile aspects through defensive organizations. These organizations numb the adolescent toward both triangular reality and narcissistic defenses. The families of such young people may be part of the organization and the analyst can also be recruited to participate in it. But the analyst's perception can become blurry and this fact makes him appear stupid. Aspects of the myths of Narcissus and Oedipus are used here as models for studying stupidity. The analysis of a psychotic teenage girl who is symbiotic in relation to her family shows how the analytical field can be invaded by defensive configurations. Collusions of idealization and domination/submission involve the young person, her family and the analyst but the defensive organizations are only identified after their traumatic breakdown. The expansion of the symbolic network allows symbiotic transgenerational organizations to be identified, while models related to enactments prove helpful for understanding technical ups and downs. The paper ends with imaginative conjectures where Oedipus, as 'patient', is compared to the patient discussed here. These conjectures lead to reinterpretations of aspects of the Oedipus myth. The reinterpretations, together with the theoretical and clinical study, may serve as models for understanding the technical ups and downs in working with troubled teens.

  1. Pharmacotherapies for Retinal Detachment.

    PubMed

    Wubben, Thomas J; Besirli, Cagri G; Zacks, David N

    2016-07-01

    Retinal detachment is an important cause of visual loss. Currently, surgical techniques, including vitrectomy, scleral buckle, and pneumatic retinopexy, are the only means to repair retinal detachment and restore vision. However, surgical failure rates may be as high as 20%, and visual outcomes continue to vary secondary to multiple processes, including postoperative cystoid macular edema, epiretinal membrane formation, macular folds, and, ultimately, photoreceptor death. Therefore, pharmacotherapies are being sought to aid the success rates of modern surgical techniques and reduce or slow the degeneration of photoreceptors during retinal detachment. This review discusses potential therapeutic avenues that aid in retinal reattachment, reduce the rate of retinal redetachment by limiting proliferative vitreoretinopathy, and protect against photoreceptor cell death.

  2. The Detached Haze Layer in Titan's Mesosphere

    NASA Astrophysics Data System (ADS)

    Lavvas, P.; Yelle, R. V.; Vuitton, V.

    2008-12-01

    sedimentation and coagulation of particles in the detached layer. This is further supported from the particle size range retrieved for the detached layer (35-45 nm), being approximately equal to the radii of ~50 nm for the monomers of the aggregate aerosols in the main haze layer. It follows that aerosols on Titan are formed primarily in the thermosphere, rather than the stratosphere as assumed in many pre-Cassini studies. This is consistent with the detection of negatively charged aerosols in the thermosphere by Cassini/CAPS. These conclusions are supported by microphysical aerosol models that couple the detached haze layer and the main haze layer and extend into the thermosphere. Our calculations suggest that the detached haze layer is due to the transition in the growth of particles from spherical shape to aggregates of fractal structure. The rapid increase in the size of the particles with the onset of fractal growth, in combination with the decrease of their settling velocity, casts them invisible in the transition region. This optical illusion process explains the well-defined and symmetric structure of the detached layer, something difficult to explain under a pure advection scenario. Further investigation of the processes defining the growth of the particles is required in order to understand why the transition takes place at this region and how the particles produced at higher altitudes by high energy radical and ion chemistry, are defining the vertical haze opacity in Titan's atmosphere.

  3. Detachment of Tertiary Dendrite Arms during Controlled Directional Solidification in Aluminum - 7 wt Percent Silicon Alloys: Observations from Ground-based and Microgravity Processed Samples

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N.; Erdman, Robert; Van Hoose, James R.; Tewari, Surendra; Poirier, David

    2012-01-01

    Electron Back Scattered Diffraction results from cross-sections of directionally solidified aluminum 7wt% silicon alloys unexpectedly revealed tertiary dendrite arms that were detached and mis-oriented from their parent arm. More surprisingly, the same phenomenon was observed in a sample similarly processed in the quiescent microgravity environment aboard the International Space Station (ISS) in support of the joint US-European MICAST investigation. The work presented here includes a brief introduction to MICAST and the directional solidification facilities, and their capabilities, available aboard the ISS. Results from the ground-based and microgravity processed samples are compared and possible mechanisms for the observed tertiary arm detachment are suggested.

  4. Controlling marginally detached divertor plasmas

    DOE PAGES

    Eldon, David; Kolemen, Egemen; Barton, Joseph L.; ...

    2017-05-04

    A new control system at DIII-D has stabilized the inter-ELM detached divertor plasma state for H-mode in close proximity to the threshold for reattachment, thus demonstrating the ability to maintain detachment with minimal gas puffing. When the same control system was instead ordered to hold the plasma at the threshold (here defined as Te = 5 eV near the divertor target plate), the resulting Te profiles separated into two groups with one group consistent with marginal detachment, and the other with marginal attachment. The plasma dithers between the attached and detached states when the control system attempts to hold at the threshold. The control system is upgraded from the one described in and it handles ELMing plasmas by using real time Dα measurements to remove during-ELM slices from real time Te measurements derived from divertor Thomson scattering. The difference between measured and requested inter-ELM Te is passed to a PID (proportionalintegral-derivative) controller to determine gas puff commands. While some degree of detachment is essential for the health of ITER’s divertor, more deeply detached plasmas have greater radiative losses and, at the extreme, confinement degradation, making it desirable to limit detachment to the minimum level needed to protect the target plate. However, the observed bifurcation in plasma conditions at the outer strike point with the ion B ×more » $$\

  5. Ion processing element with composite media

    DOEpatents

    Mann, Nick R [Blackfoot, ID; Tranter, Troy J [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Sebesta, Ferdinand [Prague, CZ

    2009-03-24

    An ion processing element employing composite media disposed in a porous substrate, for facilitating removal of selected chemical species from a fluid stream. The ion processing element includes a porous fibrous glass substrate impregnated by composite media having one or more active components supported by a matrix material of polyacrylonitrile. The active components are effective in removing, by various mechanisms, one or more constituents from a fluid stream passing through the ion processing element. Due to the porosity and large surface area of both the composite medium and the substrate in which it is disposed, a high degree of contact is achieved between the active component and the fluid stream being processed. Further, the porosity of the matrix material and the substrate facilitates use of the ion processing element in high volume applications where it is desired to effectively process a high volume flows.

  6. Ion processing element with composite media

    DOEpatents

    Mann, Nick R.; Tranter, Troy J.; Todd, Terry A.; Sebesta, Ferdinand

    2003-02-04

    An ion processing element employing composite media disposed in a porous substrate, for facilitating removal of selected chemical species from a fluid stream. The ion processing element includes a porous fibrous glass substrate impregnated by composite media having one or more active components supported by a matrix material of polyacrylonitrile. The active components are effective in removing, by various mechanisms, one or more constituents from a fluid stream passing through the ion processing element. Due to the porosity and large surface area of both the composite medium and the substrate in which it is disposed, a high degree of contact is achieved between the active component and the fluid stream being processed. Further, the porosity of the matrix material and the substrate facilitates use of the ion processing element in high volume applications where it is desired to effectively process a high volume flows.

  7. Cluster Ions and Atmospheric Processes

    NASA Astrophysics Data System (ADS)

    D'Auria, R.; Turco, R. P.

    We investigate the properties and possible roles of naturally occurring ions under at- mospheric conditions. Among other things, the formation of stable charged molecular clusters represents the initial stages of aerosol nucleation [e.g., Keesee and Castle- man, 1982], while the conversion of vapor to aggregates is the first step in certain atmospheric phase transitions [e.g. Hamill and Turco, 2000]. We analyze the stability and size distributions of common ionic clusters by solving the differential equations describing their growth and loss. The necessary reaction rate coefficients are deter- mined using kinetic and thermodynamic data. The latter are derived from direct labo- ratory measurements of equilibrium constants, from the classical charged liquid drop model applied to large aggregates (i.e., the Thomson model [Thomson, 1906]), and from quantum mechanical calculations of the thermodynamic potentials associated with the cluster structures. This approach allows us to characterize molecular clusters across the entire size range from true molecular species to larger aggregates exhibiting macroscopic behavior [D'Auria, 2001]. Cluster systems discussed in this talk include the proton hydrates (PHs) and nitrate-water and nitrate-nitric acid series [D'Auria and Turco, 2001]. These ions have frequently been detected in the stratosphere and tropo- sphere [e.g., Arnold et al., 1977; Viggiano and Arnold, 1981]. We show how the pro- posed hybrid cluster model can be extended to a wide range of ion systems, including non-proton hydrates (NPHs), mixed-ligand clusters such as nitrate-water-nitric acid and sulfate-sulfuric acid-water, as well as more exotic species containing ammonia, pyridine and other organic compounds found on ions [e.g., Eisele, 1988; Tanner and Eisele, 1991]. References: Arnold, F., D. Krankowsky and K. H. Marien, First mass spectrometric measurements of posi- tive ions in the stratosphere, Nature, 267, 30-32, 1977. D'Auria, R., A study of ionic

  8. Experimental Characterization of Plasma Detachment from Magnetic Nozzles

    NASA Astrophysics Data System (ADS)

    Olsen, Christopher Scott

    Magnetic nozzles, like Laval nozzles, are observed in several natural systems and have application in areas such as electric propulsion and plasma processing. Plasma flowing through these nozzles is inherently tied to the field lines and must separate for momentum redirection or particle transport to occur. Plasma detachment and associated mechanisms from a magnetic nozzle are investigated. Experimental results are presented from the plume of the VASIMRRTM VX-200 device flowing along an axisymmetric magnetic nozzle and operated at two ion energies to explore momentum dependent detachment. The argon plume expanded into a 150m3 vacuum chamber where the background pressure was low enough that charge-exchange mean-free-paths were longer than experiment scale lengths. This magnetic nozzle system is demonstrated to hydrodynamically scale up to astrophysical plasmas, particularly the solar chromosphere, implying general relevance to many systems. Plasma parameters were mapped over a large spatial range using measurements from multiple plasma diagnostics. The data show that the plume does not follow the magnetic field lines. A mapped integration of the ion flux shows the plume may be divided into three regions where 1) the plume briefly follows the magnetic flux, 2) diverges quadratically before 3) expanding with linear trajectories. Transitioning from region 1→2, the ion flux departs from the magnetic flux suggesting ion detachment. An instability forms in region 2 driving an oscillating electric field that causes ions to expand before enhancing electron cross-field transport through anomalous resistivity. Transitioning from region 2→3 the electric field dissipates, the trajectories linearize, and the plume effectively detaches. A delineation of sub-to-super Alfvenic flow aligns well with the inflection points of the linearization without a change in magnetic topology. The detachment process is best described as a two part process: First, ions detach by a breakdown of

  9. Development of ion sources for materials processing in china

    SciTech Connect

    Zhao, W.J.; Ren, X.T.; Zhao, H.W.

    2006-03-15

    This article reviews the development of ion sources for materials processing and the progress of commercial product of ion sources in China. The various ion-beam processing and the relative needs to ion sources are mentioned and discussed, such as ion sources with ion implantation, plasma immersion ion implantation, ion-beam-assisted deposition, ion-beam deposition, and so on. The states of progress for different kinds of ion sources specially for electron cyclotron resonance/microwave, metal vapor vacuum arc, radio frequency (rf) ion source, end-Hall ion source, and cluster ion source, are given and discussed.

  10. Ion beam processing of advanced electronic materials

    SciTech Connect

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B.; International Business Machines Corp., Yorktown Heights, NY . Thomas J. Watson Research Center; Oak Ridge National Lab., TN )

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  11. The symbol detachment problem.

    PubMed

    Pezzulo, Giovanni; Castelfranchi, Cristiano

    2007-06-01

    In situated and embodied approaches it is commonly assumed that the dynamics of sensorimotor engagement between an adaptive agent and its environment are crucial in understanding natural cognition. This perspective permits to address the symbol grounding problem, since the aboutness of any mental state arising during agent-environment engagement is guaranteed by their continuous coupling. However, cognitive agents are also able to formulate representations that are detached from the current state of affairs, such as expectations and goals. Moreover, they can act on their representations before--or instead of--acting directly on the environment, for example building the plan of a bridge and not directly the bridge. On the basis of representations, actions such as planning, remembering or imagining are possible that are disengaged from the current sensorimotor cycle, and often functional to future-oriented conducts. A new problem thus has to be acknowledged, the symbol detachment problem: how and why do situated agents develop representations that are detached from their current sensorimotor interaction, but nevertheless preserve grounding and aboutness? How do cognitive agents progressively acquire a range of capabilities permitting them to deal not only with the current situation but also with alternative, in particular future states of affairs? How do they develop the capability of acting on their representations instead of acting directly on the world? In a theoretical and developmental perspective, we propose that anticipation plays a crucial role in the detachment process: anticipatory representations, originally detached from the sensorimotor cycle for the sake of action control, are successively exapted for bootstrapping increasingly complex cognitive capabilities.

  12. Process parameters optimization in ion exchange 238Pu aqueous processing

    NASA Astrophysics Data System (ADS)

    Pansoy-Hjelvik, M. E.; Nixon, J.; Laurinat, J.; Brock, J.; Silver, G.; Reimus, M.; Ramsey, K. B.

    2000-07-01

    This paper describes bench-scale efforts (5-7 grams of 238Pu) to optimize the ion exchange process for 234U separation with minimal 238Pu losses to the effluent and wash liquids. The bench-scale experiments also determine the methodology to be used for the full-scale process: 5 kg238Pu annual throughput. Heat transfer calculations used to determine the thermal gradients expected during ion exchange processing are also described. The calculations were performed in collaboration with Westinghouse Savannah River Technology Center (WSRTC) and provide information for the design of the full-scale ion exchange equipment.

  13. Fundamental Concepts of Ion-Beam Processing

    NASA Astrophysics Data System (ADS)

    Averback, R. S.; Bellon, P.

    The basic concepts underlying the response of materials to ion-beam irradiation are outlined. These include the slowing of energetic ions, the creation of defects, sputtering, ion-beam mixing, the acceleration of kinetic processes, and phase transformations. Several examples are cited to illustrate how each of these concepts can be exploited to modify materials in ways not easily achieved, or not even possible, by more conventional processing methods. The chapter attempts to provide a physical understanding of the basic effects of ion-beam irradiation on materials, to enable readers in other areas of research to better understand the more technical chapters that follow, and to develop ideas relevant to their own disciplines. We provide references to more quantitative treatments of the topics covered here.

  14. Composite media for ion processing

    DOEpatents

    Mann, Nick R.; Wood, Donald J.; Todd, Terry A.; Sebesta, Ferdinand

    2009-12-08

    Composite media, systems, and devices for substantially removing, or otherwise processing, one or more constituents of a fluid stream. The composite media comprise a plurality of beads, each having a matrix substantially comprising polyacrylonitrile (PAN) and supporting one or more active components which are effective in removing, by various mechanisms, one or more constituents from a fluid stream. Due to the porosity and large surface area of the beads, a high level of contact is achieved between composite media of the present invention and the fluid stream being processed. Further, the homogeneity of the beads facilitates use of the beads in high volume applications where it is desired to effectively process a large volume of flow per unit of time.

  15. Indirect processes in electron-ion scattering

    SciTech Connect

    Bottcher, C.; Griffin, D.C.; Pindzola, M.S.; Phaneuf, R.A.

    1983-10-01

    A summary is given of an informal workshop held at Oak Ridge National Laboratory on June 22-23, 1983, in which the current status of theoretical calculations of indirect processes in electron-ion scattering was reviewed. Processes of particular interest in astrophysical and fusion plasmas were emphasized. Topics discussed include atomic structure effects, electron-impact ionization, and dielectronic recombination.

  16. Measurements of Scattering Processes in Negative Ion- Atom Collisions

    SciTech Connect

    Kvale, T. J.

    2000-12-22

    The main research activity is to study various scattering processes which occur in H{sup -} collisions with atomic (specifically, noble gas and atomic hydrogen) targets in the intermediate energy region. These processes include: elastic scattering, single- and double-electron detachment, and target excitation/ionization.

  17. Plasma Detachment Study in VASIMR

    NASA Astrophysics Data System (ADS)

    Ilin, A. V.; Díaz, F. R. Chang; Squire, J. P.; Breizman, B. N.; Novakovski, S. V.; Sagdeev, R. Z.

    2000-10-01

    We present kinetic and MHD simulations of plasma detachment in the exhaust of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR). The detachment is associated with a transition from subalfvenic to superalfvenic plasma flow in the magnetic nozzle. As a result, the kinetic energy of the outgoing plasma flow is greater than the magnetic field energy in the exhaust area, so that the plasma is no longer confined by the magnetic field. We model the outgoing plasma flow under the assumptions that the plasma is collisionless and has a constant electron temperature. Particle simulations show that the ion motion may become nonadiabatic in the exhaust area as the magnetic field decreases downstream. This effect should facilitate the detachment.

  18. Vertical profiles and two-dimensional distributions of carbon line emissions from C2+-C5+ ions in attached and RMP-assisted detached plasmas of large helical device

    NASA Astrophysics Data System (ADS)

    Zhang, Hongming; Morita, Shigeru; Dai, Shuyu; Oishi, Tetsutarou; Goto, Motoshi; Huang, Xianli; Kawamura, Gakushi; Kobayashi, Masahiro; Liu, Yang; Murakami, Izumi; Narushima, Yoshiro

    2017-02-01

    RMP. It is found that the narrow strip-shaped impurity trace emitted along the edge X-point and its width are sensitive to the cross-field impurity diffusion coefficient, DZ⊥. As a result, the value of DZ⊥ of C3+ ions is evaluated to be 20 times larger than that of the bulk ions in the Rax = 3.90 m configuration, while the reason is unclear at present. The measured 2-D carbon distribution is also discussed and compared to the structure of the m/n = 1/1 magnetic island, which quickly expanded during the appearance of the plasma detachment.

  19. Particle Simulations of Plasma Detachment in VASIMR

    NASA Technical Reports Server (NTRS)

    Ilin, A. V.; ChangDiaz, F. R.; Squire, J. P.; Breizman, B. N.; Carter, M. D.; Novakovski, S. V.

    1999-01-01

    The particle simulations in a Variable Specific Impulse Magnetoplasma Rocket (VASIMR) currently include self-consistent calculation of. 1) stationary magnetic field in plasma, 2) ion density and velocity, 3) ion-cyclotron radio-frequency heating, 4) ambipolar electric field. The assumptions of quasineutral and collissionless plasma are based on the range of operating VASIMR parameters. The main motivation for the particle simulation in VASIMR is plasma detachment from the magnetic field in the exhaust area. The plasma detachment is caused mainly by the Larmor radius increase. The plasma beta effect on detachment is observed and investigated as well. The results of particle simulations are compared with those from MHD simulations.

  20. Particle Simulations of Plasma Detachment in VASIMR

    NASA Technical Reports Server (NTRS)

    Ilin, A. V.; ChangDiaz, F. R.; Squire, J. P.; Breizman, B. N.; Carter, M. D.; Novakovski, S. V.

    1999-01-01

    The particle simulations in a Variable Specific Impulse Magnetoplasma Rocket (VASIMR) currently include self-consistent calculation of. 1) stationary magnetic field in plasma, 2) ion density and velocity, 3) ion-cyclotron radio-frequency heating, 4) ambipolar electric field. The assumptions of quasineutral and collissionless plasma are based on the range of operating VASIMR parameters. The main motivation for the particle simulation in VASIMR is plasma detachment from the magnetic field in the exhaust area. The plasma detachment is caused mainly by the Larmor radius increase. The plasma beta effect on detachment is observed and investigated as well. The results of particle simulations are compared with those from MHD simulations.

  1. Controlling marginally detached divertor plasmas

    NASA Astrophysics Data System (ADS)

    Eldon, D.; Kolemen, E.; Barton, J. L.; Briesemeister, A. R.; Humphreys, D. A.; Leonard, A. W.; Maingi, R.; Makowski, M. A.; McLean, A. G.; Moser, A. L.; Stangeby, P. C.

    2017-06-01

    A new control system at DIII-D has stabilized the inter-ELM detached divertor plasma state for H-mode in close proximity to the threshold for reattachment, thus demonstrating the ability to maintain detachment with minimal gas puffing. When the same control system was instead ordered to hold the plasma at the threshold (here defined as T e  =  5 eV near the divertor target plate), the resulting T e profiles separated into two groups with one group consistent with marginal detachment, and the other with marginal attachment. The plasma dithers between the attached and detached states when the control system attempts to hold at the threshold. The control system is upgraded from the one described in Kolemen et al (2015 J. Nucl. Mater. 463 1186) and it handles ELMing plasmas by using real time D α measurements to remove during-ELM slices from real time T e measurements derived from divertor Thomson scattering. The difference between measured and requested inter-ELM T e is passed to a PID (proportional-integral-derivative) controller to determine gas puff commands. While some degree of detachment is essential for the health of ITER’s divertor, more deeply detached plasmas have greater radiative losses and, at the extreme, confinement degradation, making it desirable to limit detachment to the minimum level needed to protect the target plate (Kolemen et al 2015 J. Nucl. Mater. 463 1186). However, the observed bifurcation in plasma conditions at the outer strike point with the ion B   ×  \

  2. Stability of Detached Solidification

    NASA Technical Reports Server (NTRS)

    Mazuruk, K.; Volz, M. P.; Croell, A.

    2009-01-01

    Bridgman crystal growth can be conducted in the so-called "detached" solidification regime, where the growing crystal is detached from the crucible wall. A small gap between the growing crystal and the crucible wall, of the order of 100 micrometers or less, can be maintained during the process. A meniscus is formed at the bottom of the melt between the crystal and crucible wall. Under proper conditions, growth can proceed without collapsing the meniscus. The meniscus shape plays a key role in stabilizing the process. Thermal and other process parameters can also affect the geometrical steady-state stability conditions of solidification. The dynamic stability theory of the shaped crystal growth process has been developed by Tatarchenko. It consists of finding a simplified autonomous set of differential equations for the radius, height, and possibly other process parameters. The problem then reduces to analyzing a system of first order linear differential equations for stability. Here we apply a modified version of this theory for a particular case of detached solidification. Approximate analytical formulas as well as accurate numerical values for the capillary stability coefficients are presented. They display an unexpected singularity as a function of pressure differential. A novel approach to study the thermal field effects on the crystal shape stability has been proposed. In essence, it rectifies the unphysical assumption of the model that utilizes a perturbation of the crystal radius along the axis as being instantaneous. It consists of introducing time delay effects into the mathematical description and leads, in general, to stability over a broader parameter range. We believe that this novel treatment can be advantageously implemented in stability analyses of other crystal growth techniques such as Czochralski and float zone methods.

  3. Optimization of the ion implantation process

    NASA Astrophysics Data System (ADS)

    Maczka, D.; Latuszynski, A.; Kuduk, R.; Partyka, J.

    This work is devoted to the optimization of the ion implantation process in the implanter Unimas of the Institute of Physics, Maria Curie-Sklodowska University, Lublin. The results obtained during several years of operation allow us to determine the optimal work parameters of the device [1-3].

  4. Low-energy electron attachment and detachment in vibrationally excited oxygen

    NASA Astrophysics Data System (ADS)

    Aleksandrov, N. L.; Anokhin, E. M.

    2009-11-01

    Three-body electron attachment to O2 molecules and electron detachment from O_{2}^{-} ions have been theoretically studied in vibrationally excited oxygen and O2-containing mixtures. Assuming that electron attachment and detachment proceed via the formation of vibrationally excited temporary O_{2}^{-} ions, the rates of these processes were determined on the basis of the statistical approach for the vibrational transfer and relaxation in collisions between O_{2}^{-} ions and O2 molecules. The calculated attachment and detachment rate constants turned out to agree well with available measurements in unexcited oxygen. This method was extended to calculate attachment and detachment rates in vibrationally excited oxygen. It was shown that the effect of vibrational excitation on electron detachment is profound, whereas attachment of low-energy electrons to vibrationally excited O2 is inefficient. The calculated vibrational distribution of stable O_{2}^{-} ions turned out to be non-equilibrium in an excited gas and the effective vibrational temperature of the ions was much lower than the vibrational temperature of molecules. An analytical method was suggested to determine this distribution and the effective vibrational temperature. The calculated rate constants were used to simulate the formation and decay of an electron-beam-generated plasma in N2 : O2 mixtures at elevated vibrational temperatures. The calculations showed that vibrational excitation of molecules leads to orders of magnitude increase in the plasma density and in the plasma lifetime, in agreement with available observations.

  5. Dynamical processes in heavy ion reactions

    SciTech Connect

    Blann, M.; Remington, B.A.

    1988-07-25

    In this report I review the physical assumptions of the Boltzmann Master Equation (BME). Comparisons of the model with experimental neutron spectra gated on evaporation residues for a range of incident projectile energies and masses are presented; next, I compare n spectra gated on projectile-like fragments, followed by comparisons with ungated, inclusive proton spectra. I will then consider secondary effects from the nucleon-nucleon processes involved in the heavy ion relaxation processes, specifically the high energy ..gamma..-rays which have been observed at energies up to 140 MeV in collisions of heavy ions of 20/endash/84 MeV/..mu... Another secondary effect, subthreshold pion production, was covered in the XVII School and will not be repeated. 39 refs., 16 figs.

  6. Trapped Atomic Ions and Quantum Information Processing

    SciTech Connect

    Wineland, D. J.; Leibfried, D.; Bergquist, J. C.; Blakestad, R. B.; Bollinger, J. J.; Britton, J.; Chiaverini, J.; Epstein, R. J.; Hume, D. B.; Itano, W. M.; Jost, J. D.; Koelemeij, J. C. J.; Langer, C.; Ozeri, R.; Reichle, R.; Rosenband, T.; Schaetz, T.; Schmidt, P. O.; Seidelin, S.; Shiga, N.

    2006-11-07

    The basic requirements for quantum computing and quantum simulation (single- and multi-qubit gates, long memory times, etc.) have been demonstrated in separate experiments on trapped ions. Construction of a large-scale information processor will require synthesis of these elements and implementation of high-fidelity operations on a very large number of qubits. This is still well in the future. NIST and other groups are addressing part of the scaling issue by trying to fabricate multi-zone arrays of traps that would allow highly-parallel and scalable processing. In the near term, some simple quantum processing protocols are being used to aid in quantum metrology, such as in atomic clocks. As the number of qubits increases, Schroedinger's cat paradox and the measurement problem in quantum mechanics become more apparent; with luck, trapped ion systems might be able to shed light on these fundamental issues.

  7. Trapped Atomic Ions and Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Wineland, D. J.; Leibfried, D.; Bergquist, J. C.; Blakestad, R. B.; Bollinger, J. J.; Britton, J.; Chiaverini, J.; Epstein, R. J.; Hume, D. B.; Itano, W. M.; Jost, J. D.; Knill, M.; Koelemeij, J. C. J.; Langer, C.; Ozeri, R.; Reichle, R.; Rosenband, T.; Schaetz, T.; Schmidt, P. O.; Seidelin, S.; Shiga, N.; Wesenberg, J. H.

    2006-11-01

    The basic requirements for quantum computing and quantum simulation (single- and multi-qubit gates, long memory times, etc.) have been demonstrated in separate experiments on trapped ions. Construction of a large-scale information processor will require synthesis of these elements and implementation of high-fidelity operations on a very large number of qubits. This is still well in the future. NIST and other groups are addressing part of the scaling issue by trying to fabricate multi-zone arrays of traps that would allow highly-parallel and scalable processing. In the near term, some simple quantum processing protocols are being used to aid in quantum metrology, such as in atomic clocks. As the number of qubits increases, Schrödinger's cat paradox and the measurement problem in quantum mechanics become more apparent; with luck, trapped ion systems might be able to shed light on these fundamental issues.

  8. Posterior vitreous detachment.

    PubMed

    Thimons, J J

    1992-01-01

    Posterior vitreous detachment is an expected consequence of aging, but it can also be the initiating cause of a retinal detachment. To understand the mechanism of posterior vitreous detachment and its sequelae, it is necessary to appreciate the anatomy of the vitreous, its development, and the pathogenesis of vitreous degeneration. This paper is a discussion of these considerations, the types of complications that may result from vitreous detachment, the proper examination of patients who present with the symptoms of vitreous detachment, and appropriate patient management.

  9. Seismic analysis of linked geological processes in the transitional domain of gravity detachment systems: deepwater western Nigeria delta

    NASA Astrophysics Data System (ADS)

    Leduc, Amelie

    Two and three-dimensional seismic data are used to investigate some stratigraphic relationships between sedimentation, deformation and fluid flow at the lateral margin of a gravity detachment system. Three themes were studied. In the Niger Delta, a right-lateral strike-slip fault with a displacement of around 7 km occurs across 75 km. It is interpreted as the lateral strike-slip domain, linked to the updip extensional domain and the downdip compression zone of a gravity detachment system. Structural and kinematic evidence, such as present-day propagating strike-slip faults, for possible future lateral expansions of the lateral strike-slip domain, is described. We expect to observe similar domains at the margins of other preserved gravitational collapse sliding over a detachment whose efficiency in causing downdip slip may vary laterally. Using 3D data from both Mauritania and Nigeria, the interactions between tear faults and deepwater channels are studied. Structural observations combined with channel analysis are performed in four case studies, illustrating that tear faults influence channel development throughout their evolution. Some examples across tear fault zones are presented, and it is expected to find such interactions elsewhere in the world. A simple model of development of vertical fluid flow pipes is established using two examples that are 400 - 600 m wide and ~ 2000 - 2500 m high. Both examples are located at the crest of rollover anticlines and rooted in buried channel-complexes tilted during fold growth. At the crest of the structures and within the connected permeable reservoir intervals of the channel complexes, lateral pressure transfer caused the pore pressure to reach critical levels, leading to hydraulic fracturing of the overburden. Although hydrocarbons may migrate upwards through the consequent chimney systems, the pipes are not necessarily indicators of hydrocarbon charge of the channel complexes.

  10. Signal processing for ION mobility spectrometers

    NASA Technical Reports Server (NTRS)

    Taylor, S.; Hinton, M.; Turner, R.

    1995-01-01

    Signal processing techniques for systems based upon Ion Mobility Spectrometry will be discussed in the light of 10 years of experience in the design of real-time IMS. Among the topics to be covered are compensation techniques for variations in the number density of the gas - the use of an internal standard (a reference peak) or pressure and temperature sensors. Sources of noise and methods for noise reduction will be discussed together with resolution limitations and the ability of deconvolution techniques to improve resolving power. The use of neural networks (either by themselves or as a component part of a processing system) will be reviewed.

  11. ION EXCHANGE ADSORPTION PROCESS FOR PLUTONIUM SEPARATION

    DOEpatents

    Boyd, G.E.; Russell, E.R.; Taylor, M.D.

    1961-07-11

    Ion exchange processes for the separation of plutonium from fission products are described. In accordance with these processes an aqueous solution containing plutonium and fission products is contacted with a cation exchange resin under conditions favoring adsorption of plutonium and fission products on the resin. A portion of the fission product is then eluted with a solution containing 0.05 to 1% by weight of a carboxylic acid. Plutonium is next eluted with a solution containing 2 to 8 per cent by weight of the same carboxylic acid, and the remaining fission products on the resin are eluted with an aqueous solution containing over 10 per cent by weight of sodium bisulfate.

  12. Rhegmatogenous retinal detachment treatment guidelines.

    PubMed

    García-Arumí, J; Martínez-Castillo, V; Boixadera, A; Blasco, H; Marticorena, J; Zapata, M Á; Macià, C; Badal, J; Distéfano, L; Rafart, J M; Berrocal, M; Zambrano, A; Ruíz-Moreno, J M; Figueroa, M S

    2013-01-01

    This paper outlines general guidelines following the initial diagnosis of rhegmatogenous retinal detachment. These include preoperative evaluation, treatment, possible intra- and post-operative complications, retinal re-detachment, and all therapeutic options available for each case. Treatment of the traumatic retinal detachment is also described, due to its importance and peculiarities. Treatment or prophylactic guidelines are suggested for the different types of retinal detachment described. These are based on both the experience of the ophthalmologists that have participated in preparing the guidelines, and also on evidence-based grading linked to bibliographical sources. However, these guidelines should not be interpreted as being mandatory. Given that there is a wide spectrum of options for treatment of retinal detachment, the surgeons' experience with one or other surgical technique will be of utmost importance in obtaining the best surgical result. As guidelines, they are intended as an additional aid to the surgeon during the decision-making process, with the expectation that the final choice will still be left to the surgeon's judgment and past experience.

  13. A New Interpretation of the CrO-Photoelectron Detachment Experiment

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Gutsev, G. L.; Arnold, Jim (Technical Monitor)

    2001-01-01

    CASSCF/MRCI calculations are performed on CrO(-) and CrO. The ground state of CrO(-) is identified as 4-II, not 6-Epsilon(+), as recently suggested. We assign the experimental detachment features to the seven one-electron processes arising from the two ion states.

  14. Descemet membrane detachment.

    PubMed

    Mackool, R J; Holtz, S J

    1977-03-01

    Four eyes of three patients had extensive postoperative Descemet membrane (DM) detachment. Blood was present just anterior to the DM in three of the four eyes and later converted to and persisted as pigment. Haziness of the cornea at the level of the DM could be seen with reattachment. Detachments of the DM are classified as planar when there is 1 mm or less separation of the DM from its overlying stroma in all areas. Nonplanar DM detachments exceed 1 mm of separation. Planar detachments have a much better prognosis than nonplanar detachments do, with or without descemetopexy. Repair of DM detachments, when necessary, should include air injection, with the lease possible instrumentation of the DM.

  15. Electron detachment and relaxation of OH-(aq).

    PubMed

    Petersen, Christian; Thøgersen, Jan; Jensen, Svend Knak; Keiding, Søren R

    2007-11-15

    Femtosecond transient absorption spectroscopy is used to study the primary reaction dynamics of photoinduced electron detachment of the hydroxide ion in water, OH- (aq). The electron is detached by excitation of OH- (aq) to the charge-transfer-to-solvent (CTTS) state at 200 nm. The subsequent relaxation processes are probed in the spectral range from 193 to 800 nm with femtosecond time resolution. We determine both the time-dependent quantum yields of OH- (aq), OH(aq), and e-(aq), and we observe a transient spectral signature which is assigned to relaxation of hot (OH-)* ions formed via solvent-assisted conversion of the excited CTTS state to OH-. The primary quantum yield of OH(aq) is 65 +/- 5%, while recombination with e-(aq) reduces the yield to 34% after 5 ps and 12% after 200 ps. The yield of hot (OH-)* ions is 35 +/- 5%. Rotational anisotropy measurements of OH- (aq) and OH(aq) indicate a reorientation time for OH- (aq) of 1.9 ps, while no rotational anisotropy is resolved for the OH(aq) radical within our time resolution of 0.3 ps. This is consistent with the notion that OH(aq) radicals formed after electron detachment are only weakly bound to the hydrogen bond network of water. The assignment of the experimental data is supported by a series of electronic structure calculations of simple complexes of OH- (H(2)O)(n).

  16. Retinal detachment repair

    MedlinePlus

    Scleral buckling; Vitrectomy; Pneumatic retinopexy; Laser retinopexy; Rhegmatogenous retinal detachment repair ... it meets the hole in the retina. Scleral buckling can be done using numbing medicine while you ...

  17. Coherent and turbulent process analysis of the effects of a longitudinal vortex on boundary layer detachment on a NACA0015 foil

    NASA Astrophysics Data System (ADS)

    Prothin, Sebastien; Djeridi, Henda; Billard, Jean-Yves

    2014-05-01

    In this paper, the influence of a single tip vortex on boundary layer detachment is studied. This study offers a preliminary approach in order to better understand the interaction between a propeller hub vortex and the rudder installed in its wake. This configuration belongs to the field of marine propulsion and encompasses such specific problem as cavitation inception, modification of propulsive performances and induced vibrations. To better understand the complex mechanisms due to propeller-rudder interactions it was decided to emphasize configurations where the hub vortex is generated by an elliptical 3-D foil and is located upstream of a 2-D NACA0015 foil at high incidences for a Reynolds number of 5×105. The physical mechanisms were studied using Time Resolved Stereoscopic Particle Image Velocimetry (TR-SPIV) techniques. Particular attention was paid to the detachment at 25° incidence and a detailed cartography of the mean and turbulent properties of the wake is presented. Proper Orthogonal Decomposition (POD) analysis was applied in order to highlight the unsteady nature of the flow using phase averaging based on the first POD coefficients to characterize the turbulent and coherent process in the near wake of the rudder.

  18. Observation of mutual neutralization in detached plasma

    NASA Astrophysics Data System (ADS)

    Akira, Tonegawa; Isao, Shirota; Ken'ichi, Yoshida; Masataka, Ono; Kazutaka, Kawamura; Tuguhiro, Watanabe; Nobuyoshi, Ohyabu; Hajime, Suzuki; Kazuo, Takayama

    2001-10-01

    Mutual neutralization in collisions between negative ions and positive ions in molecular activated recombination (MAR) has been observed in a high density magnetized sheet plasma source TPDSHEET-IV(Test Plasma produced by Directed current for SHEET plasma) device. Measurements of the negative ion density of hydrogen atom, the electron density, electron temperature, and the heat load to the target plate were carried out in hydrogen high density plasma with hydrogen gas puff. A cylindrical probe made of tungsten ( 0.4 x 2 cm) was used to measure the spatial profiles of H- by a probe-assisted laser photodetachment The Balmer spectra of visible light emission from hydrogen or helium atoms were detected in front of the target plate. A small amount of secondary hydrogen gas puffing into a hydrogen plasma reduced strongly the heat flux to the target and increased rapidly the density of negative ions of hydrogen atom in the circumference of the plasma, while the conventional radiative and three-body recombination processes were disappeared. These results can be well explained by taking the charge exchange recombination of MAR in the detached plasma into account.

  19. Modeling of Detached Solidification

    NASA Technical Reports Server (NTRS)

    Regel, Liya L.; Wilcox, William R.; Popov, Dmitri

    1997-01-01

    Our long term goal is to develop techniques to achieve detached solidification reliably and reproducibly, in order to produce crystals with fewer defects. To achieve this goal it is necessary to understand thoroughly the physics of detached solidification. It was the primary objective of the current project to make progress toward this complete understanding. 'Me products of this grant are attached. These include 4 papers and a preliminary survey of the observations of detached solidification in space. We have successfully modeled steady state detached solidification, examined the stability of detachment, and determined the influence of buoyancy-driven convection under different conditions. Directional solidification in microgravity has often led to ingots that grew with little or no contact with the ampoule wall. When this occurred, crystallographic perfection was usually greatly improved -- often by several orders of magnitude. Indeed, under the Soviet microgravity program the major objective was to achieve detached solidification with its resulting improvement in perfection and properties. Unfortunately, until recently the true mechanisms underlying detached solidification were unknown. As a consequence, flight experiments yielded erratic results. Within the past three years, we have developed a new theoretical model that explains many of the flight results. This model gives rise to predictions of the conditions required to yield detached solidification.

  20. On plasma detachment in propulsive magnetic nozzles

    SciTech Connect

    Ahedo, Eduardo; Merino, Mario

    2011-05-15

    Three detachment mechanisms proposed in the literature (via resistivity, via electron inertia, and via induced magnetic field) are analyzed with an axisymmetric model of the expansion of a small-beta, weakly collisional, near-sonic plasma in a diverging magnetic nozzle. The model assumes cold, partially magnetized ions and hot, isothermal, fully magnetized electrons. Different conditions of the plasma beam at the nozzle throat are considered. A central feature is that a positive thrust gain in the nozzle of a plasma thruster is intimately related to the azimuthal current in the plasma being diamagnetic. Then, and contrary to existing expectations, the three aforementioned detachment mechanisms are divergent, that is, the plasma beam diverges outwards of the guide nozzle, further hindering its axial expansion and the thrust efficiency. The rate of divergent detachment is quantified for the small-parameter range of the three mechanisms. Alternative mechanisms for a convergent detachment of the plasma beam are suggested.

  1. Materials processing with intense pulsed ion beams

    SciTech Connect

    Rej, D.J.; Davis, H.A.; Olson, J.C.

    1996-12-31

    We review research investigating the application of intense pulsed ion beams (IPIBs) for the surface treatment and coating of materials. The short range (0.1-10 {mu}m) and high-energy density (1-50 J/cm{sup 2}) of these short-pulsed ({le} 1 {mu}s) beams (with ion currents I = 5 - 50 kA, and energies E = 100 - 1000 keV) make them ideal to flash-heat a target surface, similar to the more familiar pulsed laser processes. IPIB surface treatment induces rapid melt and solidification at up to 10{sup 10} K/s to cause amorphous layer formation and the production of non-equilibrium microstructures. At higher energy density the target surface is vaporized, and the ablated vapor is condensed as coatings onto adjacent substrates or as nanophase powders. Progress towards the development of robust, high-repetition rate IPIB accelerators is presented along with economic estimates for the cost of ownership of this technology.

  2. Prompt processes in heavy ion reactions

    SciTech Connect

    Blann, M.; Remington, B.A.

    1987-12-01

    We test a relaxation model based on two body nucleon-nucleon scattering processes to interpret phenomena observed in heavy ion reactions. We use the Boltzmann Master Equation to accomplish this. By assuming that the projectile nucleons partition the total excitation with equal a-priori probability of all configurations, we are able to reproduce several sets of neutron spectra from /sup 20/Ne and /sup 12/C induced reactions on /sup 165/Ho and from reactions of /sup 40/Ar or /sup 40/Ca. We point out ambiguities in deducing angle-integrated energy spectra from double differential spectra. With no additional free parameters, our model successfully reproduces a large body of high energy ..gamma..-ray spectra by assuming an incoherent n-p-bremsstrahlung mechanism. 45 refs., 13 figs.

  3. Development of industrial ion implantation and ion assisted coating processes: A perspective

    NASA Astrophysics Data System (ADS)

    Legg, Keith O.; Solnick-Legg, Hillary

    1989-04-01

    Ion beam processes have gone through a series of developmental stages, from being the mainstay of the semiconductor industry for production of integrated circuits, to new commercial processes for biomedical, aerospace and other industries. Although research is still continuing on surface modification using ion beam methods, ion implantation and ion assisted coatings for treatment of metals, ceramics, polymers and composites must now be considered viable industrial processes of benefit in a wide variety of applications. However, ion implantation methods face various barriers to acceptability, in terms not only of other surface treatment processes, but for implantation itself. This paper will discuss some of the challenges faced by a small company whose primary business is development and marketing of ion implantation and ion-assisted coating processes.

  4. Photodetachment process for beam neutralization

    DOEpatents

    Fink, Joel H. [Livermore, CA; Frank, Alan M. [Livermore, CA

    1979-02-20

    A process for neutralization of accelerated ions employing photo-induced charge detachment. The process involves directing a laser beam across the path of a negative ion beam such as to effect photodetachment of electrons from the beam ions. The frequency of the laser beam employed is selected to provide the maximum cross-section for the photodetachment process.

  5. Photodetachment process for beam neutralization

    DOEpatents

    Fink, J.H.; Frank, A.M.

    1979-02-20

    A process for neutralization of accelerated ions employing photo-induced charge detachment is disclosed. The process involves directing a laser beam across the path of a negative ion beam such as to effect photodetachment of electrons from the beam ions. The frequency of the laser beam employed is selected to provide the maximum cross-section for the photodetachment process. 2 figs.

  6. Plasma and ion beam processing at Los Alamos

    SciTech Connect

    Rej, D.J.; Davis, H.A.; Henins, I.

    1994-07-01

    Efforts are underway at Los Alamos National Laboratory to utilize plasma and intense ion beam science and technology of the processing of advanced materials. A major theme involves surface modification of materials, e.g., etching, deposition, alloying, and implantation. In this paper, we concentrate on two programs, plasma source ion implantation and high-intensity pulsed ion beam deposition.

  7. Secondary ion coincidence in highly charged ion based secondary ion mass spectroscopy for process characterization

    SciTech Connect

    Hamza, A.V.; Schenkel, T.; Barnes, A.V.; Schneider, D.H.

    1999-01-01

    Coincidence counting in highly charged ion based secondary ion mass spectroscopy has been applied to the characterization of selective tungsten deposition via disilane reduction of tungsten hexafluoride on a patterned SiO{sub 2}/Si wafer. The high secondary ion yield and the secondary ion emission from a small area produced by highly charged ions make the coincidence technique very powerful.

  8. Divertor plasma detachment

    SciTech Connect

    Krasheninnikov, S. I.; Kukushkin, A. S.; Pshenov, A. A.

    2016-05-15

    Regime with the plasma detached from the divertor targets (detached divertor regime) is a natural continuation of the high recycling conditions to higher density and stronger impurity radiation loss. Both the theoretical considerations and experimental data show clearly that the increase of the impurity radiation loss and volumetric plasma recombination causes the rollover of the plasma flux to the target when the density increases, which is the manifestation of detachment. Plasma-neutral friction (neutral viscosity effects), although important for the sustainment of high density/pressure plasma upstream and providing the conditions for efficient recombination and power loss, is not directly involved in the reduction of the plasma flux to the targets. The stability of detachment is also discussed.

  9. Divertor plasma detachment

    NASA Astrophysics Data System (ADS)

    Krasheninnikov, S. I.; Kukushkin, A. S.; Pshenov, A. A.

    2016-05-01

    Regime with the plasma detached from the divertor targets (detached divertor regime) is a natural continuation of the high recycling conditions to higher density and stronger impurity radiation loss. Both the theoretical considerations and experimental data show clearly that the increase of the impurity radiation loss and volumetric plasma recombination causes the rollover of the plasma flux to the target when the density increases, which is the manifestation of detachment. Plasma-neutral friction (neutral viscosity effects), although important for the sustainment of high density/pressure plasma upstream and providing the conditions for efficient recombination and power loss, is not directly involved in the reduction of the plasma flux to the targets. The stability of detachment is also discussed.

  10. Retinal detachment repair - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100132.htm Retinal detachment repair - series—Normal anatomy To use the ... to slide 6 out of 6 Overview The retina is the internal layer of the eye that ...

  11. Retinal detachment in pseudophakia.

    PubMed

    Galin, M A; Poole, T A; Obstbaum, S A

    1979-07-01

    In a series of cataract patients excluding myopic individuals, under age 60 years, and cases in which vitreous loss occurred, retinal detachment was no less frequent after intracapsular cataract extraction and Sputnik iris supported lenses than in controls. Both groups were followed up for a minimum of two years. The detachments predominantly occurred from retinal breaks in areas of the retina that looked normal preoperatively.

  12. Surface processing using water cluster ion beams

    NASA Astrophysics Data System (ADS)

    Takaoka, Gikan H.; Ryuto, Hiromichi; Takeuchi, Mitsuaki; Ichihashi, Gaku

    2013-07-01

    Vaporized water clusters were produced by an adiabatic expansion phenomenon, and various substrates such as Si(1 0 0), SiO2, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polycarbonate (PC) were irradiated by water cluster ion beams. The sputtered depth increased with increasing acceleration voltage, and the sputtering rate was much larger than that obtained using Ar monomer ion irradiation. The sputtering yield for PMMA was approximately 200 molecules per ion, at an acceleration voltage of 9 kV. X-ray photoelectron spectroscopy (XPS) measurements showed that high-rate sputtering for the PMMA surface can be ascribed to the surface erosion by the water cluster ion irradiation. Furthermore, the micropatterning was demonstrated on the PMMA substrate. Thus, the surface irradiation by water cluster ion beams exhibited a chemical reaction based on OH radicals, as well as excited hydrogen atoms, which resulted in a high sputtering rate and low irradiation damage of the substrate surfaces.

  13. Radiation hardened PMOS process with ion implanted threshold adjust

    NASA Technical Reports Server (NTRS)

    Jhabvala, M.

    1979-01-01

    By including specific process modifications the effect of ion implantation on radiation hardness can be minimized and radiation hard ion implanted MOS circuits can be fabricated. The experimental procedure followed was to examine key processing steps (with respect to radiation hardness) on ion-implanted individual PMOS transistors. The individual transistors were evaluated by continuously monitoring the threshold voltage as the transistors were being irradiated. By comparing runs it was possible to deduce what is considered a radiation hard ion implanted process. Tests with a complex LSI PMOS IC processor chip containing over 2000 transistors and resistors were also conducted

  14. Models of Plasma Processes in Electrostatic Ion Thrusters

    NASA Astrophysics Data System (ADS)

    Katz, Ira

    2004-11-01

    Under the Project Prometheus Program, NASA is studying the feasibility of large, interplanetary spacecraft using nuclear reactors to provide electricity for multi-kilowatt ion thrusters. For these missions, such as the proposed Jupiter Icy Moons Orbiter (JIMO), ion thrusters will be required to operate for as long as 15 years, several times the longest demonstrated ion thruster life. In order to predict thruster life, a team of researchers at JPL is developing a suite of computer models that describe in two and three dimensions the dominant plasma processes that take place in electrostatic ion xenon thrusters. These models are being developed in close coordination with researchers who measure the plasma properties inside the thruster components. This paper reviews the physics contained in models of plasma generation and current flow in the hollow cathode insert region, discharge chamber ionization processes, grid ion optics, and thruster plumes including primary beam ions, ion-neutral scattering, and charge exchange.

  15. Composition and process for separating cesium ions from an acidic aqueous solution also containing other ions

    DOEpatents

    Dietz, M.L.; Horwitz, E.P.; Bartsch, R.A.; Barrans, R.E. Jr.; Rausch, D.

    1999-03-30

    A crown ether cesium ion extractant is disclosed as is its synthesis. The crown ether cesium ion extractant is useful for the selective purification of cesium ions from aqueous acidic media, and more particularly useful for the isolation of radioactive cesium-137 from nuclear waste streams. Processes for isolating cesium ions from aqueous acidic media using the crown ether cesium extractant are disclosed as are processes for recycling the crown ether cesium extractant and processes for recovering cesium from a crown ether cesium extractant solution. 4 figs.

  16. Composition and process for separating cesium ions from an acidic aqueous solution also containing other ions

    DOEpatents

    Dietz, Mark L.; Horwitz, E. Philip; Bartsch, Richard A.; Barrans, Jr., Richard E.; Rausch, David

    1999-01-01

    A crown ether cesium ion extractant is disclosed as is its synthesis. The crown ether cesium ion extractant is useful for the selective purification of cesium ions from aqueous acidic media, and more particularly useful for the isolation of radioactive cesium-137 from nuclear waste streams. Processes for isolating cesium ions from aqueous acidic media using the crown ether cesium extractant are disclosed as are processes for recycling the crown ether cesium extractant and processes for recovering cesium from a crown ether cesium extractant solution.

  17. Detached rock evaluation device

    DOEpatents

    Hanson, David R.

    1986-01-01

    A rock detachment evaluation device (10) having an energy transducer unit 1) for sensing vibrations imparted to a subject rock (172) for converting the sensed vibrations into electrical signals, a low band pass filter unit (12) for receiving the electrical signal and transmitting only a low frequency segment thereof, a high band pass filter unit (13) for receiving the electrical signals and for transmitting only a high frequency segment thereof, a comparison unit (14) for receiving the low frequency and high frequency signals and for determining the difference in power between the signals, and a display unit (16) for displaying indicia of the difference, which provides a quantitative measure of rock detachment.

  18. The Meningo-Orbital Band: Microsurgical Anatomy and Surgical Detachment of the Membranous Structures through a Frontotemporal Craniotomy with Removal of the Anterior Clinoid Process.

    PubMed

    Fukuda, Hitoshi; Evins, Alexander I; Burrell, Justin C; Iwasaki, Koichi; Stieg, Philip E; Bernardo, Antonio

    2014-04-01

    Objective To describe the microanatomy of the meningo-orbital band (MOB) and its associated membranes, and propose a stepwise method for their detachment while minimizing potential complications. Design Cadaveric and prospective clinical. Setting Microneurosurgery Skull Base Laboratory, Weill Cornell Medical College (New York, NY) and Shiroyama Hospital (Osaka, Japan). Participants Five preserved cadaveric heads (10 sides) and five patients requiring surgical detachment of the MOB in 2012. Results MOB detachment and subsequent extradural anterior clinoidectomies were successfully performed on five clinical cases. Detachment of the MOB was accomplished using a four-step dissection based on the structure's detailed microanatomy and included (1) partial removal of the lateral wall of the superior orbital fissure, (2) incising of the lateral periosteal dura of the superior orbital fissure, (3) peeling off the dura propria of the temporal lobe from the inner cavernous membrane, and (4) fully detaching the exposed MOB from the periorbita. Conclusion Understanding the complex microanatomy of these structures enabled a safe and effective stepwise detachment of the MOB. We recommend that surgeons possess sufficient anatomical knowledge before surgically manipulating this structure.

  19. The Meningo-Orbital Band: Microsurgical Anatomy and Surgical Detachment of the Membranous Structures through a Frontotemporal Craniotomy with Removal of the Anterior Clinoid Process

    PubMed Central

    Fukuda, Hitoshi; Evins, Alexander I.; Burrell, Justin C.; Iwasaki, Koichi; Stieg, Philip E.; Bernardo, Antonio

    2013-01-01

    Objective To describe the microanatomy of the meningo-orbital band (MOB) and its associated membranes, and propose a stepwise method for their detachment while minimizing potential complications. Design Cadaveric and prospective clinical. Setting Microneurosurgery Skull Base Laboratory, Weill Cornell Medical College (New York, NY) and Shiroyama Hospital (Osaka, Japan). Participants Five preserved cadaveric heads (10 sides) and five patients requiring surgical detachment of the MOB in 2012. Results MOB detachment and subsequent extradural anterior clinoidectomies were successfully performed on five clinical cases. Detachment of the MOB was accomplished using a four-step dissection based on the structure's detailed microanatomy and included (1) partial removal of the lateral wall of the superior orbital fissure, (2) incising of the lateral periosteal dura of the superior orbital fissure, (3) peeling off the dura propria of the temporal lobe from the inner cavernous membrane, and (4) fully detaching the exposed MOB from the periorbita. Conclusion Understanding the complex microanatomy of these structures enabled a safe and effective stepwise detachment of the MOB. We recommend that surgeons possess sufficient anatomical knowledge before surgically manipulating this structure. PMID:24719799

  20. Fast ion swapping for quantum-information processing

    NASA Astrophysics Data System (ADS)

    Kaufmann, H.; Ruster, T.; Schmiegelow, C. T.; Luda, M. A.; Kaushal, V.; Schulz, J.; von Lindenfels, D.; Schmidt-Kaler, F.; Poschinger, U. G.

    2017-05-01

    We demonstrate a swap gate between laser-cooled ions in a segmented microtrap via fast physical swapping of the ion positions. This operation is used in conjunction with qubit initialization, manipulation, and readout and with other types of shuttling operations such as linear transport and crystal separation and merging. Combining these operations, we perform quantum process tomography of the swap gate, obtaining a mean process fidelity of 99.5(5)%. The swap operation is demonstrated with motional excitations below 0.05(1) quantum for all six collective modes of a two-ion crystal for a process duration of 42 μ s . Extending these techniques to three ions, we reverse the order of a three-ion crystal and reconstruct the truth table for this operation, resulting in a mean process fidelity of 99.96(13)% in the logical basis.

  1. Numerical simulation of plasma processes driven by transverse ion heating

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra; Chan, C. B.

    1993-01-01

    The plasma processes driven by transverse ion heating in a diverging flux tube are investigated with numerical simulation. The heating is found to drive a host of plasma processes, in addition to the well-known phenomenon of ion conics. The downward electric field near the reverse shock generates a doublestreaming situation consisting of two upflowing ion populations with different average flow velocities. The electric field in the reverse shock region is modulated by the ion-ion instability driven by the multistreaming ions. The oscillating fields in this region have the possibility of heating electrons. These results from the simulations are compared with results from a previous study based on a hydrodynamical model. Effects of spatial resolutions provided by simulations on the evolution of the plasma are discussed.

  2. Numerical analysis of H(-) ion transport processes in Cs-seeded negative ion sources.

    PubMed

    Matsushita, D; Takado, N; Hatayama, A; Inoue, T

    2008-02-01

    The H(-) ion transport processes are numerically simulated to understand the extraction process of surface-produced H(-) ions. The three-dimensional transport code using Monte Carlo method has been applied to calculate the H(-) ion extraction probabilities in the model geometry of the JAEA 10 ampere negative ion source. The roles of (1) filter magnetic field and (2) collisions with neutrals (H(0) atoms and H(2) molecules) on the H(-) ion extraction are systematically studied. The results show that H(-) ions are extracted mainly by the filter magnetic field under the low gas pressure condition. The simulation results of extracted H(-) ion beam intensity in the JAEA 10 ampere negative ion source without the magnetic filter tend to be smaller than the experimental results, especially under the low pressure condition. Further model improvements, e.g., modeling and implementation of the effects of the electric field near the extraction aperture, will be required to understand the extraction process of the H(-) ions under the low gas pressure condition.

  3. Measurement of electronegativity at different laser wavelengths: accuracy of Langmuir probe assisted laser photo-detachment

    NASA Astrophysics Data System (ADS)

    Sirse, N.; Oudini, N.; Bendib, A.; Ellingboe, A. R.

    2016-08-01

    Langmuir probe (LP) assisted pulsed laser photo-detachment (LPD) of negative ions is one of the frequently used diagnostic techniques in electronegative plasmas. The technique is based on measuring the rise in electron saturation current following photo-detachment. During the photo-detachment process it is assumed that the background electron parameters (temperature and density) remain unchanged in the laser channel and the photo-detached electrons thermalize instantaneously with the background electrons (same temperature). Therefore, the measured electronegativity should be independent of laser wavelengths. However, our recent simulation results (2015 Phys. Plasmas 22 073509) demonstrates a failure of these assumptions and suggests that the measured rise in electron saturation current has a dependence on the laser wavelength. This letter presents experimental evidence in support of these simulation results. In this work, photo-detachment is performed at two different laser wavelengths in an oxygen inductively coupled plasma discharge. Electronegativity measured by LP assisted LPD is compared with those obtained by the hairpin probe (HPP) assisted LPD which is based on quasi-neutrality assumption. The experimental results reveal that the electronegativities measured by LP assisted LPD are affected by the laser wavelength, whereas, electronegativities measured by HPP assisted LPD are almost independent. The discrepancy between the measurements is higher at high electronegativities. In conclusion, the experimental results validate the weakness of assumptions to estimate electronegativity from LPD combined with LP and therefore emphasizes the need of a more realistic model to analyze raw data or an alternate solution is to utilize HPP.

  4. Measurements of scattering processes in negative ion: Atom collisions. Technical progress report, 1 September 1991--31 December 1994

    SciTech Connect

    Kvale, T.J.

    1994-09-27

    This report describes the progress made on the research objectives during the past three years of the grant. This research project is designed to study various scattering processes which occur in H{sup {minus}} collisions with atomic (specifically, noble gas and atomic hydrogen) targets in the intermediate energy region. These processes include: elastic scattering, single- and double-electron detachment, and target excitation/ionization. For the elastic and target inelastic processes where H{sup {minus}} is scattered intact, the experimental technique of Ion Energy-Loss Spectroscopy (IELS) will be employed to identify the final target state(s). In most of the above processes, cross sections are unknown both experimentally and theoretically. The measurements will provide total cross sections (TCS) initially, and once the angular positioning apparatus is installed, will provide angular differential cross sections (ADCS).

  5. Status and directions of modified tribological surfaces by ion processes

    NASA Technical Reports Server (NTRS)

    Spalvins, Talivaldis

    1988-01-01

    An overview is presented of recent advances in modifying contacting surfaces in motion by the various ion assisted surface coating/modification processes to reduce and control tribological failures. The ion assisted coating processes and the surface modification processes offer the greatest potential to custom tailor and optimize the tribological performance. Hard, wear resistant and low shear coatings deposited by the ion assisted processes are discussed. Primarily the recent advances of sputtered MoS2 ion plated Au, Ag, Pb lubricating films and sputtered and ion plated hard, wear resistant TiN, HfN, TiC films are described in terms of structural property performance interrelationships which lead to improved adhesion, cohesion, nucleation, morphological growth, density, film thickness as determined by structural and chemical characterization and frictional and wear behavior. Also, the recent tribological advances using the surface modification processes such as ion implantation, ion beam mixing is discussed with emphasis on the development of lubricous high temperature ceramic surfaces.

  6. Influence of expanding and contracting magnetic field configurations on detached plasma formation in a linear plasma device

    NASA Astrophysics Data System (ADS)

    Hayashi, Y.; Ohno, N.; Kajita, S.; Tanaka, H.

    2017-06-01

    We investigated the effects of magnetic field structure on detached plasma formation by simulating magnetically expanding and contracting plasma in a linear plasma device. The present study helps to characterize the geometries of a conventional poloidal divertor and advanced divertors, e.g., super-X divertor. The total ion particle flux measured with a large-diameter target plate dramatically changed under the detached plasma condition compared to that in attached plasma. Under the detached plasma condition, the magnetically expanding plasma clearly exhibited a significant influence on the degradation of detached plasma formation. Further, the magnetically contracting plasma slightly enhanced the electron-ion recombination (EIR) processes. By changing the magnetic field structure from contraction to expansion, the electron density (ne) decreased and the electron temperature (Te) increased upstream from the recombination front, leading to the degradation of the EIR processes. The effect of the decrease in parallel flow velocity under the magnetically contracting plasma on the plasma detachment was not observed because the driven flow due to pressure gradient compensated the effect.

  7. Effects of van der Waals forces and salt ions on the growth of water films on ice and the detachment of CO2 bubbles

    NASA Astrophysics Data System (ADS)

    Thiyam, P.; Lima, E. R. A.; Malyi, O. I.; Parsons, D. F.; Buhmann, S. Y.; Persson, C.; Boström, M.

    2016-02-01

    We study the effect of salts on the thickness of wetting films on melting ice and interactions acting on CO2 bubble near ice-water and vapor-water interfaces. Governing mechanisms are the Lifshitz and the double-layer interactions in the respective three-layer geometries. We demonstrate that the latter depend on the Casimir-Polder interaction of the salt ions dissolved in water with the respective ice, vapor and CO2 interfaces, as calculated using different models for their effective polarizability in water. Significant variation in the predicted thickness of the equilibrium water film is observed for different salt ions and when using different models for the ions' polarizabilities. We find that CO2 bubbles are attracted towards the ice-water interface and repelled from the vapor-water interface.

  8. Use of energetic ion beams in materials synthesis and processing

    SciTech Connect

    Appleton, B R

    1991-01-01

    A brief review of the use energetic ion beams and related techniques for the synthesis, processing, and characterization of materials is presented. Selected opportunity areas are emphasized with examples, and references are provided for more extensive coverage.

  9. Toward Scalable Ion Traps for Quantum Information Processing

    DTIC Science & Technology

    2010-01-01

    Deterministic quantum teleportation of atomic qubits Nature 429 737 [15] Jost J D, Home J P, Amini J M, Hanneke D, Ozeri R, Langer C, Bollinger J J, Leibfried...Toward scalable ion traps for quantum information processing This article has been downloaded from IOPscience. Please scroll down to see the full...AND SUBTITLE Toward Scalable ion Traps For Quantum Information Processing 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

  10. High-energy ion processing of materials for improved hardcoatings

    SciTech Connect

    Williams, J.M.; Gorbatkin, S.M.; Rhoades, R.L.; Oliver, W.C.; Riester, L.; Tsui, T.Y.

    1994-02-01

    Research has been directed toward use of economically viable ion processing strategies for production and improvement of hardcoatings. Processing techniques were high-energy ion implantation and electron cyclotron resonance microwave plasma processing. Subject materials were boron suboxides, Ti-6Al-4V alloy, CoCrMo alloy (a Stellite{trademark}), and electroplated Cr. These materials may be regarded either as coatings themselves (which might be deposited by thermal spraying, plasma processing, etc.) or in some cases, as substrates whose surfaces can be improved. hardness and other properties in relation to process variables are reported.

  11. Power processing technology for spacecraft primary ion propulsion

    NASA Technical Reports Server (NTRS)

    Biess, J. J.; Inouye, L. Y.; Frye, R. J.

    1980-01-01

    Advanced technologies developed in support of Ion Propulsion power processing, including the power circuitry portion of the Series L-C Resonant Inverter, Beam Supply, power components, packaging and heat pipe cooling of the 30 cm Ion Engine Power Processor are described. Both the transistorized and SCR versions of the Series L-C Resonant Inverter Beam Supply are discussed. A BIMOD Ion Thruster/Power Processor Prototype Assembly is undergoing environmental and life testing. These advanced technologies can be applied advantageously to other applications of future high power space power processing equipment.

  12. Multiple-electron processes in fast ion-atom collisions

    SciTech Connect

    Schlachter, A.S.

    1989-03-01

    Research in atomic physics at the Lawrence Berkeley Laboratory Super-HILAC and Bevalac accelerators on multiple-electron processes in fast ion-atom collisions is described. Experiments have studied various aspects of the charge-transfer, ionization, and excitation processes. Examples of processes in which electron correlation plays a role are resonant transfer and excitation and Auger-electron emission. Processes in which electron behavior can generally be described as uncorrelated include ionization and charge transfer in high-energy ion-atom collisions. A variety of experiments and results for energies from 1 MeV/u to 420 MeV/u are presented. 20 refs., 15 figs.

  13. PIC Simulation of plasma detachment

    NASA Astrophysics Data System (ADS)

    Ishiguro, Seiji; Pianpanit, Theerasarn; Hasegawa, Hiroki; Kanno, Ryutaro

    2014-10-01

    The detached plasma, which is caused by gas puffing, has been proposed and it is the most promising way to reduce the heat load to the divertor plate of fusion oriented devices. Dynamical and kinetic behavior of the detached plasma is unresolved. So we are developing particle-in-cell simulation model with atomic processes such as line radiation, ionization, charge-exchange collision and recombination. As a first step, we have performed PIC simulation with Monte Carlo collisions, where spatial and velocity space distributions of charged particles, self-consistent electric field, and atomic processes such as ionization and charge exchange are included. Temperature decrease and density increase in front of the target is observed and electric potential structure along the axis is created. This work is performed with the support and under the auspices of NIFS Collaboration Research programs (NIFS14KNXN279 and 8 NIFS13KNSS038) and the Research Cooperation Program on Hierarchy and Holism in Natural Sciences at the NINS.

  14. Microfabrication techniques for trapped ion quantum information processing

    NASA Astrophysics Data System (ADS)

    Britton, Joe

    Quantum-mechanical principles can be used to process information. In one approach, linear arrays of trapped, laser cooled ion qubits (two-level quantum systems) are confined in segmented multi-zone electrode structures. Strong Coulomb coupling between ions is the basis for quantum gates mediated by phonon exchange. Applications of Quantum Information Processing (QIP) include solution of problems believed to be intractable on classical computers. The ion trap approach to QIP requires trapping and control of numerous ions in electrode structures with many trapping zones. In support of trapped ion QIP, I investigated microfabrication of structures to trap, transport and couple large numbers of ions. Using 24Mg + I demonstrated loading and transport between zones in microtraps made of boron doped silicon. This thesis describes the fundamentals of ion trapping, the characteristics of silicon-based traps amenable to QIP work and apparatus to trap ions and characterize traps. Microfabrication instructions appropriate for nonexperts are included. A key characteristic of ion traps is the rate at which ion motional modes heat. In my traps upper bounds on heating were determined; however, heating due to externally injected noise could not be completely ruled out. Noise on the RF potential responsible for providing confinement was identified as one source of injected noise. Using the microfabrication technology developed for ion traps, I made a cantilevered micromechanical oscillator and with coworkers demonstrated a method to reduce the kinetic energy of its lowest order mechanical mode via its capacitive coupling to a driven RF resonant circuit. Cooling results from a RF capacitive force, which is phase shifted relative to the cantilever motion. The technique was demonstrated by cooling a 7 kHz fundamental mode from room temperature to 45 K. Ground state cooling of the mechanical modes of motion of harmonically trapped ions is routine; equivalent cooling of a macroscopic

  15. Gelling process of sodium alginate with bivalent ions rich microsphere: Nature of bivalent ions

    NASA Astrophysics Data System (ADS)

    Mauri, Marco; Vicini, Silvia; Castellano, Maila

    2016-05-01

    In the paper we present a new approach for obtaining a controlled gelling process of sodium alginate, based on the quantity of bivalent ions rich alginate micro-beads added as crosslinkers. Typically, calcium ions are used in gelation of alginate solutions. In this study we present different gelling systems realized with alginate microspheres, made by electrospinning methodology, enriched with different bivalent ions (Ca2+, Ba2+ and Mg2+). The microspheres were characterized under the point of view of the morphology by OM and as the ions content. Realized gels were characterized in light of the amount of the ions added to the alginate solution, and in light of the different dimensions of the micro-beads, using rheological measurements to assess the variation in the storage modulus (G'), loss modulus (G″) and complex viscosity (η*).

  16. The use of ion implantation for materials processing

    NASA Astrophysics Data System (ADS)

    Smidt, F. A.

    1986-03-01

    This report is the sixth in a series of Progress Reports on work conducted at the Naval Research Laboratory (NRL) to investigate the use of ion implantation for materials processing. The objective of the program is to develop the capabilities of ion implantation and ion beam activated deposition for new and improved surface treatment techniques of interest to Navy and DOD applications. Attainment of this objective requires both fundamental research to provide an understanding of the physical and metallurgical changes taking place in the implanted region of a material and applications oriented research to demonstrate the benefits of ion implantation. The purpose of this report is to make available from one source the results of all studies at NRL related to the use of ion implantation for materials processing so as to provide a more comprehensive picture of the scope and interrelationship of the research and to expedite technology transfer to the civilian industrial sector. The report consists of four sections describing the research and a cummulative bibliography of published papers and reports. This report describes the important factors in ion implantation science and technology and reports progress in the use of ion implantation to modify friction, wear, fatigue, corrosion, optical and magnetic properties of materials.

  17. Evaluation of negative ion distribution changes by image processing diagnostic

    SciTech Connect

    Ikeda, K. Nakano, H.; Tsumori, K.; Kisaki, M.; Nagaoka, K.; Tokuzawa, T.; Osakabe, M.; Takeiri, Y.; Kaneko, O.; Geng, S.

    2015-04-08

    Distributions of hydrogen Balmer-α (H{sub α}) intensity and its reduction behavior close to a plasma grid (PG) surface have been observed by a spectrally selective imaging system in an arc discharge type negative hydrogen ion source in National Institute for Fusion Science. H{sub α} reduction indicates a reduction of negative hydrogen ions because the mutual neutralization process between H{sup +} and H{sup −} ions causes the dominant excitation process for H{sub α} emission in the rich H{sup −} condition such as in ionic plasma. We observed a significant change in H{sub α} reduction distribution due to change in the bias voltage, which is used to suppress the electron influx. Small H{sub α} reduction in higher bias is likely because the production of negative ions is suppressed by the potential difference between the plasma and PG surface.

  18. The Use of Ion Implantation for Materials Processing.

    DTIC Science & Technology

    1980-10-06

    IPreEEhhh I l...fflllffllff NRL Memorandum Report 4341 TheUseofIon Implantation for Materials Processing Semana Progres Report for the Period 1 Oct. 1979...beam current. The temperature was judged by observing of results to be expected from such a Gaussian distribution the color of the samples through a...light multiply tion." ion channeling,’ ’ Coates-Kikuchi lines,’ physical ap- reflected between the front surface and the interface between pearance ( color

  19. COLUMBIC OXIDE ADSORPTION PROCESS FOR SEPARATING URANIUM AND PLUTONIUM IONS

    DOEpatents

    Beaton, R.H.

    1959-07-14

    A process is described for separating plutonium ions from a solution of neutron irradiated uranium in which columbic oxide is used as an adsorbert. According to the invention the plutonium ion is selectively adsorbed by Passing a solution containing the plutonium in a valence state not higher than 4 through a porous bed or column of granules of hydrated columbic oxide. The adsorbed plutonium is then desorbed by elution with 3 N nitric acid.

  20. Ion Implanted GaAs I.C. Process Technology

    DTIC Science & Technology

    1981-07-01

    in ion implantation in GaAs, coupled with better control of the substrate material. 1 Once ion implantation became a reliable processing technology it... Processing Technology for Planar GaAs Integrated Circuits," GaAs IC Symposium, Lake Tahoe, CA., Sept. 1979. 20. R.C. Eden, "GaAs Integrated Circuit Device...1980. 25. B.M. Welch, "Advances in GaAs LSI!VLSI Processing Technology ," Sol. St. Tech., Feb. 1980, pp. 95-101. 27. R. Zucca, B.M. Welch, P.M

  1. Uniformity model for energetic ion processes using a Kaufman ion source

    SciTech Connect

    Smith, D.J.; Warner, J.A.; LeBarron, N.

    1998-12-01

    Processes that use energetic ions for large substrates require that the time-averaged erosion effects from the ion flux be uniform across the surface. A numerical model has been developed to determine this flux and its effects on surface etching of a silica/photoresist combination. The geometry of the source and substrate is very similar to a typical deposition geometry with single or planetary substrate rotation. The model was used to tune an inert ion-etching process that used single or multiple Kaufman sources to less than 3% uniformity over a 30-cm aperture after etching 8 {micro}m of material. The same model can be used to predict uniformity for ion-assisted deposition (IAD).

  2. Silicon solar cells by ion implantation and pulsed energy processing

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, A. R.; Minnucci, J. A.; Shaughnessy, T. S.; Greenwald, A. C.

    1976-01-01

    A new method for fabrication of silicon solar cells is being developed around ion implantation in conjunction with pulsed electron beam techniques to replace conventional furnace processing. Solar cells can be fabricated totally in a vacuum environment at room temperature. Cells with 10% AM0 efficiency have been demonstrated. High efficiency cells and effective automated processing capabilities are anticipated.

  3. Induction of rapid detachment in Shewanella oneidensis MR-1 biofilms.

    PubMed

    Thormann, Kai M; Saville, Renée M; Shukla, Soni; Spormann, Alfred M

    2005-02-01

    evidence we conclude that detachment is a biologically controlled process and that a rapid change in oxygen concentration is a critical factor in detachment and, consequently, in dispersal of S. oneidensis cells from biofilms. Similar mechanisms might also operate in other bacteria.

  4. Dissociative processes in electron-molecular ion collisions

    NASA Astrophysics Data System (ADS)

    Djuric, Nada; Dunn, Gordon H.

    1998-10-01

    There is renewed interest in dissociation of molecular ions, primarily due to needs for modeling plasma generators for etching and deposition and for modeling edge plasmas for fusion reactors. At the same time, there are improvements in experimental techniques; e.g. use of heavy-ion storage rings has opened possibilities in dissociation studies of vibrationally relaxed molecular ions. At electron energies below the dissociation energy (D_e) of a molecular ion, the most importanat process is dissociative recombination (DR). Once the energy is above D_e, dissociative excitation (DE) is allowed, and at even higher energies dissociative ionization (DI) is energetically possible. In JILA we set up an apparatus wherein light fragment ions from DE of heteronuclear molecular ions are detected. In the heavy-ion storage ring at Stockholm (CRYRING) detection of neutral fragments was used for DE and DR studies. We will discuss the techniques and give examples of DE and DI obtainet at JILA and CRYRING [1,2,3]. Work supported in part by the Office of Fusion Energy of the U. S. DOE under Contract No. DE-A105-86ER53237 with NIST and in part by the Swedish Natural Science Research Council. 1. N. Djuric et al., Phys. Rev. A 56, 2887 (1997). 2. J. Semaniak et al., Ap. J. 498, 886 (1998). 3. J. R. Peterson et al., J. Chem. Phys. 108, 1978 (1998)

  5. A closed loop process for recycling spent lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Gratz, Eric; Sa, Qina; Apelian, Diran; Wang, Yan

    2014-09-01

    As lithium ion (Li-ion) batteries continue to increase their market share, recycling Li-ion batteries will become mandatory due to limited resources. We have previously demonstrated a new low temperature methodology to separate and synthesize cathode materials from mixed cathode materials. In this study we take used Li-ion batteries from a recycling source and recover active cathode materials, copper, steel, etc. To accomplish this the batteries are shredded and processed to separate the steel, copper and cathode materials; the cathode materials are then leached into solution; the concentrations of nickel, manganese and cobalt ions are adjusted so NixMnyCoz(OH)2 is precipitated. The precipitated product can then be reacted with lithium carbonate to form LiNixMnyCozO2. The results show that the developed recycling process is practical with high recovery efficiencies (∼90%), and 1 ton of Li-ion batteries has the potential to generate 5013 profit margin based on materials balance.

  6. Control of ion energy at the substrates during plasma processing

    NASA Astrophysics Data System (ADS)

    Wang, Shiang-Bau

    1999-11-01

    Ion bombardment plays a significant role in many aspects of plasma processing in integrated circuit manufacturing, including etch rate, etch selectivity, etched feature profiles, differential charging, deposited film quality, damage, etc. Some of these have emerged as new challenges as device sizes continue shrinking. Since those challenges are somewhat related to the ion trajectory (or ion energy), more precise control of ion bombarding energy is critical and necessary. This study combined plasma model simulation and experimental implementation to develop an ion energy distribution function (IEDF) control technique by carefully tailoring the bias voltage waveform applied to the substrate. A time-dependent, spherical-shell, whole-region plasma fluid model was constructed first to investigate the factors that affect the ion energy distribution. The simulation results show that a greatly narrowed IEDF can be obtained by applying a specially tailored bias voltage waveform composed of a series of pulses and a slow negative linear slope between pulses. The simulation also demonstrates that the IEDF produced with this technique is independent of ion mass, the technique does not induce a non-uniform substrate potential, and does produce a more precisely controllable ion energy compared to the conventional sinusoidal bias voltage power supply design. Experiments in a helicon argon plasma show good agreement with simulation results. Not limited to electropositive plasmas, this technique also demonstrates similar performance in an electronegative SF6 plasma. Experiments related to the applications of this technique in a real-time non-intrusive ion bombarding flux measurement as well as to SiO2/Si etching selectivity improvement have also been performed. The real-time non-intrusive ion bombarding flux measurements show more accurate results than are obtainable with Langmuir probes and the output can serve as a meaningful control variable for etching processes. This technique

  7. Catalytic metal ions and enzymatic processing of DNA and RNA.

    PubMed

    Palermo, Giulia; Cavalli, Andrea; Klein, Michael L; Alfonso-Prieto, Mercedes; Dal Peraro, Matteo; De Vivo, Marco

    2015-02-17

    CONSPECTUS: Two-metal-ion-dependent nucleases cleave the phosphodiester bonds of nucleic acids via the two-metal-ion (2M) mechanism. Several high-resolution X-ray structures portraying the two-metal-aided catalytic site, together with mutagenesis and kinetics studies, have demonstrated a functional role of the ions for catalysis in numerous metallonucleases. Overall, the experimental data confirm the general mechanistic hypothesis for 2M-aided phosphoryl transfer originally reported by Steitz and Steitz ( Proc. Natl. Acad. Sci. U.S.A. 1993 , 90 ( 14 ), 6498 - 6502 ). This seminal paper proposed that one metal ion favors the formation of the nucleophile, while the nearby second metal ion facilitates leaving group departure during RNA hydrolysis. Both metals were suggested to stabilize the enzymatic transition state. Nevertheless, static X-ray structures alone cannot exhaustively unravel how the two ions execute their functional role along the enzymatic reaction during processing of DNA or RNA strands when moving from reactants to products, passing through metastable intermediates and high-energy transition states. In this Account, we discuss the role of multiscale molecular simulations in further disclosing mechanistic insights of 2M-aided catalysis for two prototypical enzymatic targets for drug discovery, namely, ribonuclease H (RNase H) and type II topoisomerase (topoII). In both examples, first-principles molecular simulations, integrated with structural data, emphasize a cooperative motion of the bimetal motif during catalysis. The coordinated motion of both ions is crucial for maintaining a flexible metal-centered structural architecture exquisitely tailored to accommodate the DNA or RNA sugar-phosphate backbone during phosphodiester bond cleavage. Furthermore, our analysis of RNase H and the N-terminal domain (PAN) of influenza polymerase shows that classical molecular dynamics simulations coupled with enhanced sampling techniques have contributed to describe

  8. Plasma-Ion Processing of Three-Dimensional Components

    SciTech Connect

    Yukimura, Ken; Wei Ronghua

    2004-12-01

    Plasma-based ion implantation and deposition (PBII and D) technology has been developed rapidly in the past decade. This technique is especially promising for modifying three-dimensional components. In PBII and D, plasma is generated in the entire processing chamber and then surrounds the components. When a train of negative voltage pulses are applied to the parts, ions are drawn to all the surfaces exposed to the plasma. At a high energy, ions are implanted to the surfaces, but at a low energy and with a proper precursor gases, ions are deposited to form a film. This technology has found applications in many areas including semiconductors, automotive, aerospace, energy and biomedical. This article reviews PBII and D fundamentals, describes features of various PBII and D systems and plasma sources, and discusses implantation and deposition techniques. The paper will also present application examples of this technology.

  9. Process for recovering pertechnetate ions from an aqueous solution also containing other ions

    DOEpatents

    Rogers, R.; Horwitz, E.P.; Bond, A.H.

    1997-02-18

    A solid/liquid process for the separation and recovery of TcO{sub 4}{sup {minus}1} ions from an aqueous solution is disclosed. The solid support comprises separation particles having surface-bonded poly(ethylene glycol) groups; whereas the aqueous solution from which the TcO{sub 4}{sup {minus}1} ions are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved salt. A solid/liquid phase admixture of separation particles containing bound TcO{sub 4}{sup {minus}1} ions in such an aqueous solution that is free from MoO{sub 4}{sup {minus}2} ions is also contemplated, as is a chromatography apparatus containing that solid/liquid phase admixture. 15 figs.

  10. Process for recovering pertechnetate ions from an aqueous solution also containing other ions

    DOEpatents

    Rogers, Robin; Horwitz, E. Philip; Bond, Andrew H.

    1997-01-01

    A solid/liquid process for the separation and recovery of TcO.sub.4.sup.-1 ions from an aqueous solution is disclosed. The solid support comprises separation particles having surface-bonded poly(ethylene glycol) groups; whereas the aqueous solution from which the TcO.sub.4.sup.-1 ions are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved salt. A solid/liquid phase admixture of separation particles containing bound TcO.sub.4.sup.-1 ions in such an aqueous solution that is free from MoO.sub.4.sup.-2 ions is also contemplated, as is a chromatography apparatus containing that solid/liquid phase admixture.

  11. On detachment asymmetry and stability

    NASA Astrophysics Data System (ADS)

    Pshenov, A. A.; Kukushkin, A. S.; Krasheninnikov, S. I.

    2017-07-01

    Three issues related to the physics of divertor detachment are analyzed in detail: the criteria for the onset of complete divertor detachment, the role of neutrals in "symmetryzation" of detachment in the inner and outer divertors, and the transition to divertor detachment. The results of comprehensive 2D numerical simulations with the SOLPS4.3 package are compared with some experimental data and predictions based on simplified analytical models. It is shown that it is the ratio of the upstream plasma pressure to the specific power flux entering the recycling region that controls the local onset of detachment on a specific flux tube. Pup/qreclycl≥(Pup/qreclycl) crit remains the valid criterion also in the presence of seeded impurity, if the impurity radiation and hydrogen recycling regions are spatially separated. Detailed analysis indicates that the reverse plasma flow forming on the most heat loaded flux tubes in the outer divertor under the influence of the neutrals coming from the deeply detached inner divertor plays the key role in the detachment "symmetryzation" and allows the outer divertor to reach the detached regime. Finally, it is demonstrated that a gradual increase of the perpendicular heat transport in the edge plasma during transition to the detached regime can make this transition bifurcation-like.

  12. Integrated optics architecture for trapped-ion quantum information processing

    NASA Astrophysics Data System (ADS)

    Kielpinski, D.; Volin, C.; Streed, E. W.; Lenzini, F.; Lobino, M.

    2016-12-01

    Standard schemes for trapped-ion quantum information processing (QIP) involve the manipulation of ions in a large array of interconnected trapping potentials. The basic set of QIP operations, including state initialization, universal quantum logic, and state detection, is routinely executed within a single array site by means of optical operations, including various laser excitations as well as the collection of ion fluorescence. Transport of ions between array sites is also routinely carried out in microfabricated trap arrays. However, it is still not possible to perform optical operations in parallel across all array sites. The lack of this capability is one of the major obstacles to scalable trapped-ion QIP and presently limits exploitation of current microfabricated trap technology. Here we present an architecture for scalable integration of optical operations in trapped-ion QIP. We show theoretically that diffractive mirrors, monolithically fabricated on the trap array, can efficiently couple light between trap array sites and optical waveguide arrays. Integrated optical circuits constructed from these waveguides can be used for sequencing of laser excitation and fluorescence collection. Our scalable architecture supports all standard QIP operations, as well as photon-mediated entanglement channels, while offering substantial performance improvements over current techniques.

  13. MODELING RESULTS FROM CESIUM ION EXCHANGE PROCESSING WITH SPHERICAL RESINS

    SciTech Connect

    Nash, C.; Hang, T.; Aleman, S.

    2011-01-03

    Ion exchange modeling was conducted at the Savannah River National Laboratory to compare the performance of two organic resins in support of Small Column Ion Exchange (SCIX). In-tank ion exchange (IX) columns are being considered for cesium removal at Hanford and the Savannah River Site (SRS). The spherical forms of resorcinol formaldehyde ion exchange resin (sRF) as well as a hypothetical spherical SuperLig{reg_sign} 644 (SL644) are evaluated for decontamination of dissolved saltcake wastes (supernates). Both SuperLig{reg_sign} and resorcinol formaldehyde resin beds can exhibit hydraulic problems in their granular (nonspherical) forms. SRS waste is generally lower in potassium and organic components than Hanford waste. Using VERSE-LC Version 7.8 along with the cesium Freundlich/Langmuir isotherms to simulate the waste decontamination in ion exchange columns, spherical SL644 was found to reduce column cycling by 50% for high-potassium supernates, but sRF performed equally well for the lowest-potassium feeds. Reduced cycling results in reduction of nitric acid (resin elution) and sodium addition (resin regeneration), therefore, significantly reducing life-cycle operational costs. These findings motivate the development of a spherical form of SL644. This work demonstrates the versatility of the ion exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. The value of a resin with increased selectivity for cesium over potassium can be assessed for further development.

  14. Dynamic stability of detached solidification

    NASA Astrophysics Data System (ADS)

    Mazuruk, K.; Volz, M. P.

    2016-06-01

    A dynamic stability analysis model is developed for meniscus-defined crystal growth processes. The Young-Laplace equation is used to analyze the response of a growing crystal to perturbations to its radius and a thermal transport model is used to analyze the effect of perturbations on the evolution of the crystal-melt interface. A linearized differential equation is used to analyze radius perturbations but a linear integro-differential equation is required for the height perturbations. The stability model is applied to detached solidification under zero-gravity and terrestrial conditions. A numerical analysis is supplemented with an approximate analytical analysis, valid in the limit of small Bond numbers. For terrestrial conditions, a singularity is found to exist in the capillary stability coefficients where, at a critical value of the pressure differential across the meniscus, there is a transition from stability to instability. For the zero-gravity condition, exact formulas for the capillary stability coefficients are derived.

  15. Microfilters for biomedicine obtained by swift ion processing.

    PubMed

    Torrisi, L

    1997-01-01

    Swift ions with 50 MeV energy are used to irradiate bio-polymeric films. Lithium, carbon and oxygen beams, with fluencies ranging between 10(8) and 10(13) ions/cm2, are swept on large surfaces of hydrogenated and fluorated polymers. The electronic stopping power of the ion induces high rates of ionization, excitation and radical formation along the ion path with production of chain-scission and cross-linking processes which can be investigated by the molecular emission from the irradiated polymer. The radiation damage increases the chemical solubility of the material around the ion track up to distances of the order of 100 nm. A suitable chemical etching removes the damaged material leaving micrometric holes in the polymeric film. This process gives rise to micro-perforated films which can be used as microfilters, with sub-micrometric pore dimension, high selectivity and controllable porosity. Their use is very interesting for special applications in ultra- and microfiltration of biological liquids.

  16. One- and two-photon detachment of O-

    NASA Astrophysics Data System (ADS)

    Génévriez, Matthieu; Urbain, Xavier; Dochain, Arnaud; Cyr, Alain; Dunseath, Kevin M.; Terao-Dunseath, Mariko

    2016-08-01

    Cross sections for one- and two-photon detachment of O-(1 s22 s22 p5P2o) have been determined in a joint experimental and theoretical study. The absolute measurement is based on the animated-crossed-beam technique, which is extended to the case of pulsed lasers, pulsed ion beams, and multiphoton detachment. The ab initio calculations employ R -matrix Floquet theory, with simple descriptions of the initial bound state and the residual oxygen atom which reproduce well the electron affinity and ground-state polarizability. For one-photon detachment, the measured and computed cross sections are in good mutual agreement, departing significantly from previous reference experiments and calculations. The generalized two-photon detachment cross section, measured at the Nd:YAG laser wavelength, is in good agreement with the R -matrix Floquet calculations. Long-standing discrepancies between theory and experiment are thus resolved.

  17. Process for modifying the metal ion sorption capacity of a medium

    DOEpatents

    Lundquist, Susan H.

    2002-01-01

    A process for modifying a medium is disclosed that includes treating a medium having a metal ion sorption capacity with a solution that includes: A) an agent capable of forming a complex with metal ions; and B) ions selected from the group consisting of sodium ions, potassium ions, magnesium ions, and combinations thereof, to create a medium having an increased capacity to sorb metal ions relative to the untreated medium.

  18. Influence of atomic physics on EDGE2D-EIRENE simulations of JET divertor detachment with carbon and beryllium/tungsten plasma-facing components

    NASA Astrophysics Data System (ADS)

    Guillemaut, C.; Pitts, R. A.; Kukushkin, A. S.; Gunn, J. P.; Bucalossi, J.; Arnoux, G.; Belo, P.; Brezinsek, S.; Brix, M.; Corrigan, G.; Devaux, S.; Flanagan, J.; Groth, M.; Harting, D.; Huber, A.; Jachmich, S.; Kruezi, U.; Lehnen, M.; Marchetto, C.; Marsen, S.; Meigs, A. G.; Meyer, O.; Stamp, M.; Strachan, J. D.; Wiesen, S.; Wischmeier, M.; EFDA Contributors, JET

    2014-09-01

    The EDGE2D-EIRENE code is applied for simulation of divertor detachment during matched density ramp experiments in high triangularity, L-mode plasmas in both JET-Carbon (JET-C) and JET-ITER-Like Wall (JET-ILW). The code runs without drifts and includes either C or Be as impurity, but not W, assuming that the W targets have been coated with Be via main chamber migration. The simulations reproduce reasonably well the observed particle flux detachment as density is raised in both JET-C and JET-ILW experiments and can better match the experimental in-out divertor target power asymmetry if the heat flux entering the outer divertor is artificially set at around 2-3 times that entering the inner divertor. A careful comparison between different sets of atomic physics processes used in EIRENE shows that the detachment modelled by EDGE2D-EIRENE relies only on an increase of the particle sinks and not on a decrease of the ionization source. For the rollover and the beginning of the partially detached phase, the particle losses by perpendicular transport and the molecular activated recombination processes are mainly involved. For a deeper detachment with significant target ion flux reduction, volume recombination appears to be the main contributor. The elastic molecule-ion collisions are also important to provide good neutral confinement in the divertor and thus stabilize the simulations at low electron temperature (Te), when the sink terms are strong. Comparison between EDGE2D-EIRENE and SOLPS4.3 simulations of the density ramp in C shows similar detachment trends, but the importance of the elastic ion-molecule collisions is reduced in SOLPS4.3. Both codes suggest that any process capable of increasing the neutral confinement in the divertor should help to improve the modelling of the detachment. A further outcome of this work has been to demonstrate that key JET divertor diagnostic signals—Langmuir probe Te and bolometric tomographic reconstructions—are running beyond

  19. Optical broadband monitoring of conventional and ion processes.

    PubMed

    Ristau, Detlev; Ehlers, Henrik; Gross, Tobias; Lappschies, Marc

    2006-03-01

    This contribution is focused on applications of spectroscopic methods for the precise control of deposition processes. Besides a monochromator system with a moving grating for the deep ultraviolet/vacuum ultraviolet (DUV/VUV) spectral range, two approaches are presented for online spectrophotometers with CCD arrays. The conventional spectrophotometer is considered for the operator-assisted deposition of fluoride coatings applied in the DUV/VUV range. The concepts with CCD arrays are combined with an advanced software tool for an automatic production of optical coatings. An ion-assisted deposition process and ion-beam sputtering are considered for rapid manufacturing of complex layer systems in the visible and near-infrared spectral ranges. The present contribution summarizes and discusses the major aspects of the described combinations.

  20. PIMASERTIB AND SEROUS RETINAL DETACHMENTS

    PubMed Central

    AlAli, Alaa; Bushehri, Ahmad; Park, Jonathan C.; Krema, Hatem

    2016-01-01

    Purpose: To report a case of multifocal serous retinal detachments associated with pimasertib. Methods: The authors report a 26-year-old patient who developed bilateral multifocal serous retinal detachments appearing 2 days after starting pimasertib (as part of a clinical trial investigating its use in low-grade metastatic ovarian cancer) and rapidly resolving 3 days after stopping it. Conclusion: The mechanism of MEK inhibitor induced visual toxicity remains unclear. The pathophysiology of multifocal serous retinal detachments as a complication of pimasertib is still poorly understood. PMID:26444523

  1. Shock detachment from curved wedges

    NASA Astrophysics Data System (ADS)

    Mölder, S.

    2017-03-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  2. Shock detachment from curved wedges

    NASA Astrophysics Data System (ADS)

    Mölder, S.

    2017-09-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  3. LSI/VLSI Ion Implanted GaAs IC Processing

    DTIC Science & Technology

    1982-02-10

    insulating High Speed Logic Ion Implantation GaAs IC FET Integrated Circuits MESFET 20. ABSTRACT (Coalki. on.. roersie if oookay and IdoeI by WOOe tw**, This...The goal of this program is to realize the full potential of GaAs digital integrated circuits employing depletion mode MESFETs by developing the...Processing. The main objective of this program is to realize the full potential of GaAs digital integrated circuits by expanding and improving

  4. Quantum Information Processing with Trapped 43Ca+ Ions

    DTIC Science & Technology

    2008-03-18

    state 11 Fig.3: Deterministic quantum teleportation protocol 12 Fig.4: Density matrix of an entangled eight-ion state 13 Fig.5: Quantum process...4.3.4 Deterministic quantum teleportation Teleportation of a quantum state encompasses the complete transfer of information from one particle to...allow quantum -state teleportation to be performed. We succeeded in demonstrating deterministic quantum -state teleportation between a pair of trapped

  5. Detachment of solids and nitrifiers in integrated, fixed-film activated sludge systems.

    PubMed

    Maas, Carol L A; Parker, Wayne J; Legge, Raymond L

    2008-12-01

    Despite the importance of detachment to biofilm processes, detachment phenomena are not well understood. In this study, researchers investigated biofilm detachment from free-floating biofilm carriers that were established in an integrated, fixed-film activated sludge (IFAS) installation in Mississauga, Ontario. A method for assessing detachment from biofilm carrier systems was devised, evaluated, and refined during this study. In the absence of substrate, superficial air velocity significantly affected the 24-hour detachment rates of total suspended solids from the carriers. Short-term growth conditions did not appear to significantly affect the rate of detachment of solids and nitrifiers. The measured solids-detachment rates were found to be described by a second order function of biofilm attached growth total solids with a detachment coefficient of 0.006 +/- 0.0008 (g/m x d)(-1).

  6. Detection and quantification of microtubule detachment from centrosomes and spindle poles.

    PubMed

    Ganguly, Anutosh; Yang, Hailing; Cabral, Fernando

    2013-01-01

    Microtubule detachment from microtubule organizing centers is an important cellular process required for normal cell proliferation. When cells enter mitosis, microtubule turnover increases along with a concurrent increase in microtubule detachment. MCAK, a kinesin-related protein whose abundance is highest during the early stages of mitosis, has been shown to regulate microtubule detachment. Abnormal increases or decreases in the frequency of detachment interfere with spindle function and inhibit cell division. It has been shown that drugs able to promote microtubule assembly (e.g., paclitaxel, epothilones) prevent cell division by suppressing microtubule detachment from centrosomes. Conversely, cytotoxic concentrations of microtubule destabilizing drugs (e.g., vinblastine, nocodazole), tubulin mutations that cause paclitaxel resistance, and specific β-tubulin isotypes increase the frequency of microtubule detachment. In this chapter, we describe a method to calculate the frequency of microtubule detachment by transfecting cells with EGFP-MAP4 and directly observing detachment by live cell imaging.

  7. A Scalable Microfabricated Ion Trap for Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Maunz, Peter; Haltli, Raymond; Hollowell, Andrew; Lobser, Daniel; Mizrahi, Jonathan; Rembetski, John; Resnick, Paul; Sterk, Jonathan D.; Stick, Daniel L.; Blain, Matthew G.

    2016-05-01

    Trapped Ion Quantum Information Processing (QIP) relies on complex microfabricated trap structures to enable scaling of the number of quantum bits. Building on previous demonstrations of surface-electrode ion traps, we have designed and characterized the Sandia high-optical-access (HOA-2) microfabricated ion trap. This trap features high optical access, high trap frequencies, low heating rates, and negligible charging of dielectric trap components. We have observed trap lifetimes of more than 100h, measured trap heating rates for ytterbium of less than 40quanta/s, and demonstrated shuttling of ions from a slotted to an above surface region and through a Y-junction. Furthermore, we summarize demonstrations of high-fidelity single and two-qubit gates realized in this trap. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work was supported by the Intelligence Advanced Research Projects Activity (IARPA).

  8. Experimental study of single-electron detachment for Cu{sup −}, Ag{sup −}, Au{sup −}, Co{sup −}, and Ir{sup −} in collisions with Kr and Xe

    SciTech Connect

    Ye, Jingru; Zhao, Zilong; Zhu, Yiyang; Li, Junqin; Zhang, Xuemei

    2014-09-15

    The single electron detachment (SED) cross sections for Cu{sup −}, Ag{sup −}, Au{sup −}, Co{sup −}, and Ir{sup −} in collisions with Kr and Xe in the energy range of 10keV≤E≤30keV are measured by using the growth rate method in our experiments. The SED cross sections increase as the incident velocity increases. These data are compared with other available experimental data for the corresponding negative ions colliding with Ar. The affinities of the negative ions and the mass relation between the projectile and the target seem important in the electron detachment process.

  9. Materials and processing for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Daniel, Claus

    2008-09-01

    Lithium-ion battery technology is projected to be the leapfrog technology for the electrification of the drivetrain and to provide stationary storage solutions to enable the effective use of renewable energy sources. The technology is already in use for low-power applications such as consumer electronics and power tools. Extensive research and development has enhanced the technology to a stage where it seems very likely that safe and reliable lithium-ion batteries will soon be on board hybrid electric and electric vehicles and connected to solar cells and windmills. However, the safety of the technology is still a concern, service life is not yet sufficient, and costs are too high. This paper summarizes the state of the art of lithium-ion battery technology for nonexperts. It lists materials and processing for batteries and summarizes the costs associated with them. This paper should foster an overall understanding of materials and processing and the need to overcome the remaining barriers for a successful market introduction.

  10. Ageing dynamics of ion bombardment induced self-organization processes

    PubMed Central

    Bikondoa, Oier; Carbone, Dina; Chamard, Virginie; Metzger, Till Hartmut

    2013-01-01

    Instabilities caused during the erosion of a surface by an ion beam can lead to the formation of self-organized patterns of nanostructures. Understanding the self-organization process requires not only the in-situ characterization of ensemble averaged properties but also probing the dynamics. This can be done with the use of coherent X-rays and analyzing the temporal correlations of the scattered intensity. Here, we show that the dynamics of a semiconductor surface nanopatterned by normal incidence ion beam sputtering are age-dependent and slow down with sputtering time. This work provides a novel insight into the erosion dynamics and opens new perspectives for the understanding of self-organization mechanisms. PMID:23685386

  11. ION EXCHANGE PROCESS FOR THE RECOVERY AND PURIFICATION OF MATERIALS

    DOEpatents

    Long, R.S.; Bailes, R.H.

    1958-04-15

    A process for the recovery of certain metallic ions from aqueous solutions by ion exchange techniques is described. It is applicable to elements such as vanadium, chromium, nnanganese, and the like, which are capable of forming lower valent cations soluble in aqueous solutions and which also form ldgher valent anions soluble in aqueous acidic solutions. For example, small amounts of vanadium occurring in phosphoric acid prepared from phosphate rock may be recovered by reducing the vanadium to a trivalent cation adsorbing; the vanadium in a cationic exchange resin, then treating the resin with a suitable oxidizing agent to convert the adsorbed vanadium to a higher valent state, and finally eluting; the vanadium as an anion from the resin by means of an aqueous acidic solution.

  12. Nano-scale processes behind ion-beam cancer therapy

    NASA Astrophysics Data System (ADS)

    Surdutovich, Eugene; Garcia, Gustavo; Mason, Nigel; Solov'yov, Andrey V.

    2016-04-01

    This topical issue collates a series of papers based on new data reported at the third Nano-IBCT Conference of the COST Action MP1002: Nanoscale Insights into Ion Beam Cancer Therapy, held in Boppard, Germany, from October 27th to October 31st, 2014. The Nano-IBCT COST Action was launched in December 2010 and brought together more than 300 experts from different disciplines (physics, chemistry, biology) with specialists in radiation damage of biological matter from hadron-therapy centres, and medical institutions. This meeting followed the first and the second conferences of the Action held in October 2011 in Caen, France and in May 2013 in Sopot, Poland respectively. This conference series provided a focus for the European research community and has highlighted the pioneering research into the fundamental processes underpinning ion beam cancer therapy.

  13. HAMLET Binding to α-Actinin Facilitates Tumor Cell Detachment

    PubMed Central

    Trulsson, Maria; Yu, Hao; Gisselsson, Lennart; Chao, Yinxia; Urbano, Alexander; Aits, Sonja; Mossberg, Ann-Kristin; Svanborg, Catharina

    2011-01-01

    Cell adhesion is tightly regulated by specific molecular interactions and detachment from the extracellular matrix modifies proliferation and survival. HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a protein-lipid complex with tumoricidal activity that also triggers tumor cell detachment in vitro and in vivo, suggesting that molecular interactions defining detachment are perturbed in cancer cells. To identify such interactions, cell membrane extracts were used in Far-western blots and HAMLET was shown to bind α-actinins; major F-actin cross-linking proteins and focal adhesion constituents. Synthetic peptide mapping revealed that HAMLET binds to the N-terminal actin-binding domain as well as the integrin-binding domain of α-actinin-4. By co-immunoprecipitation of extracts from HAMLET-treated cancer cells, an interaction with α-actinin-1 and -4 was observed. Inhibition of α-actinin-1 and α-actinin-4 expression by siRNA transfection increased detachment, while α-actinin-4-GFP over-expression significantly delayed rounding up and detachment of tumor cells in response to HAMLET. In response to HAMLET, adherent tumor cells rounded up and detached, suggesting a loss of the actin cytoskeletal organization. These changes were accompanied by a reduction in β1 integrin staining and a decrease in FAK and ERK1/2 phosphorylation, consistent with a disruption of integrin-dependent cell adhesion signaling. Detachment per se did not increase cell death during the 22 hour experimental period, regardless of α-actinin-4 and α-actinin-1 expression levels but adherent cells with low α-actinin levels showed increased death in response to HAMLET. The results suggest that the interaction between HAMLET and α-actinins promotes tumor cell detachment. As α-actinins also associate with signaling molecules, cytoplasmic domains of transmembrane receptors and ion channels, additional α-actinin-dependent mechanisms are discussed. PMID:21408150

  14. HAMLET binding to α-actinin facilitates tumor cell detachment.

    PubMed

    Trulsson, Maria; Yu, Hao; Gisselsson, Lennart; Chao, Yinxia; Urbano, Alexander; Aits, Sonja; Mossberg, Ann-Kristin; Svanborg, Catharina

    2011-03-08

    Cell adhesion is tightly regulated by specific molecular interactions and detachment from the extracellular matrix modifies proliferation and survival. HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a protein-lipid complex with tumoricidal activity that also triggers tumor cell detachment in vitro and in vivo, suggesting that molecular interactions defining detachment are perturbed in cancer cells. To identify such interactions, cell membrane extracts were used in Far-western blots and HAMLET was shown to bind α-actinins; major F-actin cross-linking proteins and focal adhesion constituents. Synthetic peptide mapping revealed that HAMLET binds to the N-terminal actin-binding domain as well as the integrin-binding domain of α-actinin-4. By co-immunoprecipitation of extracts from HAMLET-treated cancer cells, an interaction with α-actinin-1 and -4 was observed. Inhibition of α-actinin-1 and α-actinin-4 expression by siRNA transfection increased detachment, while α-actinin-4-GFP over-expression significantly delayed rounding up and detachment of tumor cells in response to HAMLET. In response to HAMLET, adherent tumor cells rounded up and detached, suggesting a loss of the actin cytoskeletal organization. These changes were accompanied by a reduction in β1 integrin staining and a decrease in FAK and ERK1/2 phosphorylation, consistent with a disruption of integrin-dependent cell adhesion signaling. Detachment per se did not increase cell death during the 22 hour experimental period, regardless of α-actinin-4 and α-actinin-1 expression levels but adherent cells with low α-actinin levels showed increased death in response to HAMLET. The results suggest that the interaction between HAMLET and α-actinins promotes tumor cell detachment. As α-actinins also associate with signaling molecules, cytoplasmic domains of transmembrane receptors and ion channels, additional α-actinin-dependent mechanisms are discussed.

  15. Mechanical and tribological properties of ion beam-processed surfaces

    SciTech Connect

    Kodali, Padma

    1998-01-01

    The intent of this work was to broaden the applications of well-established surface modification techniques and to elucidate the various wear mechanisms that occur in sliding contact of ion-beam processed surfaces. The investigation included characterization and evaluation of coatings and modified surfaces synthesized by three surface engineering methods; namely, beam-line ion implantation, plasma-source ion implantation, and DC magnetron sputtering. Correlation among measured properties such as surface hardness, fracture toughness, and wear behavior was also examined. This dissertation focused on the following areas of research: (1) investigating the mechanical and tribological properties of mixed implantation of carbon and nitrogen into single crystal silicon by beam-line implantation; (2) characterizing the mechanical and tribological properties of diamond-like carbon (DLC) coatings processed by plasma source ion implantation; and (3) developing and evaluating metastable boron-carbon-nitrogen (BCN) compound coatings for mechanical and tribological properties. The surface hardness of a mixed carbon-nitrogen implant sample improved significantly compared to the unimplanted sample. However, the enhancement in the wear factor of this sample was found to be less significant than carbon-implanted samples. The presence of nitrogen might be responsible for the degraded wear behavior since nitrogen-implantation alone resulted in no improvement in the wear factor. DLC coatings have low friction, low wear factor, and high hardness. The fracture toughness of DLC coatings has been estimated for the first time. The wear mechanism in DLC coatings investigated with a ruby slider under a contact stress of 1 GPa was determined to be plastic deformation. The preliminary data on metastable BCN compound coatings indicated high friction, low wear factor, and high hardness.

  16. Ion sponge: a 3-dimentional array of quadrupole ion traps for trapping and mass-selectively processing ions in gas phase.

    PubMed

    Xu, Wei; Li, Linfan; Zhou, Xiaoyu; Ouyang, Zheng

    2014-05-06

    In this study, the concept of ion sponge has been explored for developing 3D arrays of large numbers of ion traps but with simple configurations. An ion sponge device with 484 trapping units in a volume of 10 × 10 × 3.2 cm has been constructed by simply stacking 9 meshes together. A single rf was used for trapping ions and mass-selective ion processing. The ion sponge provides a large trapping capacity and is highly transparent for transfer of ions, neutrals, and photons for gas phase ion processing. Multiple layers of quadrupole ion traps, with 121 trapping units in each layer, can operate as a single device for MS or MS/MS analysis, or as a series of mass-selective trapping devices with interlayer ion transfers facilitated by AC and DC voltages. Automatic sorting of ions to different trapping layers based on their mass-to-charge (m/z) ratios was achieved with traps of different sizes. Tandem-in-space MS/MS has also been demonstrated with precursor ions and fragment ions trapped in separate locations.

  17. Ion Sponge: A 3-Dimentional Array of Quadrupole Ion Traps for Trapping and Mass-Selectively Processing Ions in Gas Phase

    PubMed Central

    2015-01-01

    In this study, the concept of ion sponge has been explored for developing 3D arrays of large numbers of ion traps but with simple configurations. An ion sponge device with 484 trapping units in a volume of 10 × 10 × 3.2 cm has been constructed by simply stacking 9 meshes together. A single rf was used for trapping ions and mass-selective ion processing. The ion sponge provides a large trapping capacity and is highly transparent for transfer of ions, neutrals, and photons for gas phase ion processing. Multiple layers of quadrupole ion traps, with 121 trapping units in each layer, can operate as a single device for MS or MS/MS analysis, or as a series of mass-selective trapping devices with interlayer ion transfers facilitated by AC and DC voltages. Automatic sorting of ions to different trapping layers based on their mass-to-charge (m/z) ratios was achieved with traps of different sizes. Tandem-in-space MS/MS has also been demonstrated with precursor ions and fragment ions trapped in separate locations. PMID:24758328

  18. Controlled Detachment of Chemically Glued Cells.

    PubMed

    Koo, Heebeom; Hahn, Sei Kwang; Yun, Seok Hyun

    2016-11-16

    We demonstrate a chemically detachable cell-glue system based on linkers containing disulfide bonds as well as functional groups for metabolic glycoengineering and bioorthogonal click chemistry. Azide groups are generated on the cell surface by metabolic glycoengineering, and they are further modified into tetrazine (Tz) or trans-cyclooctene (TCO) using rationally designed cross-linkers. When the Tz-modified and TCO-modified cells are mixed together, cell gluing between these two cell groups is established by Tz-TCO click chemistry. This artificial cell-cell adhesion can be broken by the administration of glutathione (5 mM), which triggers the degradation of disulfide bonds. Both the gluing and detachment processes are rapid (<10 min) and minimally cytotoxic.

  19. Treatment of chromium plating process effluents with ion exchange resins.

    PubMed

    Tenório, J A; Espinosa, D C

    2001-01-01

    The surface treatment industry deals with various heavy metals, including the elements Cr, Zn, Ni, Cd, and Cu. Conventional treatments of effluents generate class I solid residue. The aim of this investigation was to study the viability of ion exchange as an alternative process for treatment of rinse water and to determine the efficacy of two ion exchange systems, System 1: "strong" cationic resin-"strong" anionic resin and System 2: "strong" cationic resin-"weak" anionic resin. Commercial resins and solutions taken from rinse tanks of chromium plating companies were used in this investigation. A two-column system, one for the cationic resin and another for the anionic resin, both with 150 ml capacity was mounted. The solution was percolated at a rate of 10 ml/min. The following solutions were used for regeneration of the resins: 2% H2SO4 for the cationic and 4% NaOH for the anionic. The percolated solutions revealed chromium contents of less than 0.25 mg/l, independent of the system used. The "strong" cationic resin-"weak" anionic resin gave excellent regeneration results. The "strong" cationic-"strong" anionic resin presented problems during regeneration, and did not release the retained ions after percolation of 2000 ml of 4% NaOH solution. It is concluded that for this type of treatment, the system composed of "strong" cationic resin and "weak" anionic resin is more appropriate.

  20. Detached Growth of Germanium and Germaniumsilicon

    NASA Technical Reports Server (NTRS)

    Dold, P.; Schweizer, M.; Szofran, F.; Benz, K. W.

    1999-01-01

    Up to now, detached growth was observed mainly under microgravity, i.e. under the absence of hydrostatic pressure that hinders the formation of a free melt meniscus. the detached growth of germanium doped with gallium was obtained under 1 g conditions, the growth was performed in quartz-glass ampoule. Part of the crystal grew without wall contact, the detached growth was observed in-situ with a CCD-camera as well as after the growth process in form of growth lines and the formation of <111> facets on the crystal surface. GeSi crystal (oriientation: <111>, maximum silicon content: 4 at%, seed material: Ge) was grown in a pBN crucible (excluding the possibility of in-situ monitoring of the growth process). The grown crystal exhibits three growth facets, indicating also wall free growth. Surface analysis of the crystals (NDIC, SEM) and characterization of crystal segregation (EDAX, resistivity measurement) and defect structure (EPD, x-ray diffraction measurements) will be presented.

  1. Detached Growth of Germanium and Germaniumsilicon

    NASA Technical Reports Server (NTRS)

    Dold, P.; Schweizer, M.; Szofran, F.; Benz, K. W.

    1999-01-01

    Up to now, detached growth was observed mainly under microgravity, i.e. under the absence of hydrostatic pressure that hinders the formation of a free melt meniscus. the detached growth of germanium doped with gallium was obtained under 1 g conditions, the growth was performed in quartz-glass ampoule. Part of the crystal grew without wall contact, the detached growth was observed in-situ with a CCD-camera as well as after the growth process in form of growth lines and the formation of <111> facets on the crystal surface. GeSi crystal (oriientation: <111>, maximum silicon content: 4 at%, seed material: Ge) was grown in a pBN crucible (excluding the possibility of in-situ monitoring of the growth process). The grown crystal exhibits three growth facets, indicating also wall free growth. Surface analysis of the crystals (NDIC, SEM) and characterization of crystal segregation (EDAX, resistivity measurement) and defect structure (EPD, x-ray diffraction measurements) will be presented.

  2. Multistep ion exchange processes of gradient refractive index rod lens.

    PubMed

    Lv, Hao; Liu, Aimei; Tong, Jufang; Yi, Xunong; Li, Qianguang; Wang, Xinmin; Ding, Yaoming

    2011-01-01

    A mathematical model for research on the refractive index profile (RIP) of multistep ion exchange processes (IEPs) of gradient refractive index rod lenses (GRINs) is established by the different initial condition and boundary condition, based on the Fickian diffusion equation. GRIN rod lenses have been fabricated using the three-step IEPs. Research results indicate that the experimental deviations of refractive index (DRI) are in good agreement with the theoretical data. The DRI of three-step IEPs is superior to the one- and two-step IEPs and smaller than 10(-5).

  3. Comparative dissociation of peptide polyanions by electron impact and photo-induced electron detachment.

    PubMed

    Larraillet, Vincent; Vorobyev, Aleksey; Brunet, Claire; Lemoine, Jérôme; Tsybin, Yury O; Antoine, Rodolphe; Dugourd, Philippe

    2010-04-01

    We compare product-ion mass spectra produced by electron detachment dissociation (EDD) and electron photodetachment dissociation (EPD) of multi-deprotonated peptides on a Fourier transform and a linear ion trap mass spectrometer, respectively. Both methods, EDD and EPD, involve the electron emission-induced formation of a radical oxidized species from a multi-deprotonated precursor peptide. Product-ion mass spectra display mainly fragment ions resulting from backbone cleavages of C(alpha)-C bond ruptures yielding a and x ions. Fragment ions originating from N-C(alpha) backbone bond cleavages are also observed, in particular by EPD. Although EDD and EPD methods involve the generation of a charge-reduced radical anion intermediate by electron emission, the product ion abundance distributions are drastically different. Both processes seem to be triggered by the location and the recombination of radicals (both neutral and cation radicals). Therefore, EPD product ions are predominantly formed near tryptophan and histidine residues, whereas in EDD the negative charge solvation sites on the backbone seem to be the most favorable for the nearby bond dissociation. 2010. Published by Elsevier Inc.

  4. Prospects for reducing the processing cost of lithium ion batteries

    DOE PAGES

    Wood III, David L.; Li, Jianlin; Daniel, Claus

    2014-11-06

    A detailed processing cost breakdown is given for lithium-ion battery (LIB) electrodes, which focuses on: elimination of toxic, costly N-methylpyrrolidone (NMP) dispersion chemistry; doubling the thicknesses of the anode and cathode to raise energy density; and, reduction of the anode electrolyte wetting and SEI-layer formation time. These processing cost reduction technologies generically adaptable to any anode or cathode cell chemistry and are being implemented at ORNL. This paper shows step by step how these cost savings can be realized in existing or new LIB manufacturing plants using a baseline case of thin (power) electrodes produced with NMP processing and amore » standard 10-14-day wetting and formation process. In particular, it is shown that aqueous electrode processing can cut the electrode processing cost and energy consumption by an order of magnitude. Doubling the thickness of the electrodes allows for using half of the inactive current collectors and separators, contributing even further to the processing cost savings. Finally wetting and SEI-layer formation cost savings are discussed in the context of a protocol with significantly reduced time. These three benefits collectively offer the possibility of reducing LIB pack cost from $502.8 kWh-1-usable to $370.3 kWh-1-usable, a savings of $132.5/kWh (or 26.4%).« less

  5. Prospects for reducing the processing cost of lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Wood, David L.; Li, Jianlin; Daniel, Claus

    2015-02-01

    A detailed processing cost breakdown is given for lithium-ion battery (LIB) electrodes, which focuses on: 1) elimination of toxic, costly N-methylpyrrolidone (NMP) dispersion chemistry; 2) doubling the thicknesses of the anode and cathode to raise energy density; and 3) reduction of the anode electrolyte wetting and SEI-layer formation time. These processing cost reduction technologies generically adaptable to any anode or cathode cell chemistry and are being implemented at ORNL. This paper shows step by step how these cost savings can be realized in existing or new LIB manufacturing plants using a baseline case of thin (power) electrodes produced with NMP processing and a standard 10-14-day wetting and formation process. In particular, it is shown that aqueous electrode processing can cut the electrode processing cost and energy consumption by an order of magnitude. Doubling the thickness of the electrodes allows for using half of the inactive current collectors and separators, contributing even further to the processing cost savings. Finally wetting and SEI-layer formation cost savings are discussed in the context of a protocol with significantly reduced time. These three benefits collectively offer the possibility of reducing LIB pack cost from 502.8 kW h-1-usable to 370.3 kW h-1-usable, a savings of 132.5/kWh (or 26.4%).

  6. The North Cycladic Detachment System

    NASA Astrophysics Data System (ADS)

    Jolivet, Laurent; Lecomte, Emmanuel; Huet, Benjamin; Denèle, Yoann; Lacombe, Olivier; Labrousse, Loïc; Le Pourhiet, Laetitia; Mehl, Caroline

    2010-01-01

    Low-angle normal faults accommodate a large part of continental post-orogenic extension. Besides the intrinsic rheological characteristics of the continental crust that may lead to the formation of shallow-dipping shear zones at the brittle-ductile transition, the role of pre-existing low-angle structures such as large thrusts has been proposed by several authors. We explore this question with the example of the North Cycladic Detachment System (NCDS) that is composed of a series of distinct detachments cropping out on the islands of Andros, Tinos and Mykonos, separating the Cycladic Blueschists in the footwall from the Upper Cycladic Nappe in the hanging wall. We show that these extensional structures are part of a single large-scale structure (more than 200 km along strike) that reactivates the Vardar suture zone. It extends eastward on Ikaria and westward offshore Evia and Thessalia where it probably connects to recent shallow-dipping normal faults evidenced on published seismic reflection profiles. The NCDS started its activity in the Oligocene concommitantly with the Aegean extension, and was still active in the Late Miocene. It has exhumed a series of metamorphic domes from southern Evia to Mykonos below low-angle detachment systems, made of low-angle normal faults and low-angle ductile shear zones. The ductile shear zones and the faults were created with a low dip and they kept the same attitude throughout their exhumation. We identify three main detachments that are part of a continuum of extension on the NCDS : Tinos detachment, Livada detachment and Mykonos detachment. A fourth detachment (Vari detachment) is the reactivation of an Eocene exhumation-related structure. Deformation in the footwall is characterized by intense stretching and flattening. Using the spatial evolution observed along strike from Andros to Mykonos we construct a history of formation of the NCDS starting with the reactivation of former thrusts leading to the exhumation of high

  7. [Surgical managment of retinal detachment].

    PubMed

    Haritoglou, C; Wolf, A

    2015-05-01

    The detachment of the neurosensory retina from the underlying retinal pigment epithelium can be related to breaks of the retina allowing vitreous fluid to gain access to the subretinal space, to exudative changes of the choroid such as tumours or inflammatory diseases or to excessive tractional forces exerted by interactions of the collagenous vitreous and the retina. Tractional retinal detachment is usually treated by vitrectomy and exudative detachment can be addressed by treatment of the underlying condition in many cases. In rhegmatogenous retinal detachment two different surgical procedures, vitrectomy and scleral buckling, can be applied for functional and anatomic rehabilitation of our patients. The choice of the surgical procedure is not really standardised and often depends on the experience of the surgeon and other more ocular factors including lens status, the number of retinal breaks, the extent of the detachment and the amount of preexisting PVR. Using both techniques, anatomic success rates of over 90 % can be achieved. Especially in young phakic patients scleral buckling offers the true advantage to prevent the progression of cataract formation requiring cataract extraction and intraocular lens implantation. Therefore, scleral buckling should be considered in selected cases as an alternative surgical option in spite of the very important technical refinements in modern vitrectomy techniques. Georg Thieme Verlag KG Stuttgart · New York.

  8. Development of a four-zone carousel process packed with metal ion-imprinted polymer for continuous separation of copper ions from manganese ions, cobalt ions, and the constituent metal ions of the buffer solution used as eluent.

    PubMed

    Jo, Se-Hee; Park, Chanhun; Yi, Sung Chul; Kim, Dukjoon; Mun, Sungyong

    2011-08-19

    A three-zone carousel process, in which Cu(II)-imprinted polymer (Cu-MIP) and a buffer solution were employed as adsorbent and eluent respectively, has been developed previously for continuous separation of Cu²⁺ (product) from Mn²⁺ and Co²⁺ (impurities). Although this process was reported to be successful in the aforementioned separation task, the way of using a buffer solution as eluent made it inevitable that the product stream included the buffer-related metal ions (i.e., the constituent metal ions of the buffer solution) as well as copper ions. For a more perfect recovery of copper ions, it would be necessary to improve the previous carousel process such that it can remove the buffer-related metal ions from copper ions while maintaining the previous function of separating copper ions from the other 2 impure heavy-metal ions. This improvement was made in this study by proposing a four-zone carousel process based on the following strategy: (1) the addition of one more zone for performing the two-step re-equilibration tasks and (2) the use of water as the eluent of the washing step in the separation zone. The operating conditions of such a proposed process were determined on the basis of the data from a series of single-column experiments. Under the determined operating conditions, 3 runs of carousel experiments were carried out. The results of these experiments revealed that the feed-loading time was a key parameter affecting the performance of the proposed process. Consequently, the continuous separation of copper ions from both the impure heavy-metal ions and the buffer-related metal ions could be achieved with a purity of 91.9% and a yield of 92.8% by using the proposed carousel process based on a properly chosen feed-loading time.

  9. On Favorable Thermal Fields for Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Stelian, Carmen; Volz, Martin P.; Derby, Jeffrey J.

    2009-01-01

    The thermal fields of two Bridgman-like configurations, representative of real systems used in prior experiments for the detached growth of CdTe and Ge crystals, are studied. These detailed heat transfer computations are performed using the CrysMAS code and expand upon our previous analyses [14] that posited a new mechanism involving the thermal field and meniscus position to explain stable conditions for dewetted Bridgman growth. Computational results indicate that heat transfer conditions that led to successful detached growth in both of these systems are in accordance with our prior assertion, namely that the prevention of crystal reattachment to the crucible wall requires the avoidance of any undercooling of the melt meniscus during the growth run. Significantly, relatively simple process modifications that promote favorable thermal conditions for detached growth may overcome detrimental factors associated with meniscus shape and crucible wetting. Thus, these ideas may be important to advance the practice of detached growth for many materials.

  10. Decay Processes of Highly Excited Laser Ions in Solids.

    NASA Astrophysics Data System (ADS)

    Collins, John Michael

    Using the techniques of luminescence spectroscopy, we have investigated the luminescent properties of a number of systems following excitation with high-energy UV radiation. After revisiting the two-photon emission from Pr^{3+} in yttrium fluoride, an investigation into the possibility of energy transfer between Pr and other rare-earth ions was carried out in the systems YF_3:Pr,Tb; YF _3:Pr,Eu; LaF_3:Pr,Tb; and LaF_3:Pr,Eu. In all systems, spectroscopic and kinetic data shows no presence of energy transfer among the dopant ions. Investigation of the Pr -Eu doped systems were hindered by the presence of divalent Eu. The cross-relaxation process among Tb ions has been studied in Y_{rm 1-x} F_3:Tb_{ rm x}, with x =.001,.004 and.05, and is shown to increase with both concentration and temperature. Kinetic studies show that at high Tb concentration, the excitation migrates through the Tb sublattice at the ^5 D_3<=vel before the cross -relaxation can occur. The migration is quenched at low temperatures. Al_2O_3 :Ti, when excited with UV radiation shows the existence of as many as three previously unreported emissions. One of these bands, centered at 560 nm and extending throughout the visible region, was studied in more detail. The decay of this emission varies from 30 musec at 300^circK to 710 musec at 20^circK, while intensity actually decreases with temperature. A model is proposed which could explain this behavior. Laser action is also reported from this band and its application as a solid-state tunable laser is discussed. A previously unreported energy transfer from Gd ^{3+} to Er^ {3+} is shown to exist in the system Y _{.34}Gd_ {.65}Er_{.01} F_3. The energy transfer process is of the non-radiative type, and is quite efficient (~80%) in this system. Kinetic studies indicate that the transfer is more efficient at lower temperatures. This behavior is explained by a redistribution with temperature of the population of Gd and Er ions and its affect on the energy

  11. Rhegmatogenous retinal detachment and conventional surgical treatment.

    PubMed

    Golubovic, M

    2013-01-01

    . According to the present risk factor, high myopia was found in 5 patients, which has been emphasized to be a significant risk factor for onset of retinal detachment. Lattice degeneration was the most common peripheral degenerative change. The most frequently found was horseshoe retinal hole with vitreous traction and the break location was most common in the upper retinal quadrants. The most commonly applied type was limbus radial buckle with encircling band, depending on the pathological process in the eye. The retina was postoperatively attached in 31 eyes. In two cases, the retina was not attached; in one eye due to the inadequately inserted implant and in the other case due to the larger number of breaks (3) with more distinct PVR (C2), and postoperative inflammation and proliferative components were more intensified. In one patient who did not have a total detachment, but had a larger break placed posterior to the equator and PVR C1, redetachment appeared one month later due to a manifested fibroproliferative reaction, although the break was closed. Regarding visual acuity, the day following the surgery there was no improvement; moreover, there was a small decline of visual acuity due to exudates in the vitreous body and vitreous hemorrhage. After 3 months, there was a significant improvement in the largest number of eyes. Intraoperative complications included intravitreous hemorrhage, and postoperative more distinct proliferative component in the vitreous body was found in two patients. Timely diagnosis and intervention in retinal detachment by application of an adequate method and less invasive technique gives excellent results in postoperative morbidity rate and rehabilitation of the vision. The results of the conventional treatment of retinal detachment justify its application in the treatment of this disease.

  12. Time evolution of the particle and heat flux of the detached plasma

    NASA Astrophysics Data System (ADS)

    Pianpanit, Theerasarn; Ishiguro, Seiji; Hasegawa, Hiroki

    2016-10-01

    The detached plasma is a regime when the particle and heat flux of the plasma are largely reduced before reaching the divertor target. Linear devices experiment data show that when the neutral gas pressure in front of the target increases the heat flux to the target largely decreases. The 1D-3V particle simulation with Monte Carlo collision and cumulative scattering angle Coulomb collision has been developed to study the kinetic effect of the detached plasma. The simulation was performed with the constant temperature and pressure of neutral gas in front of the target. A large decrease in the electron temperature from 5eV to below 1 eV follows a large decrease in the ion temperature inside the neutral gas area in the case with high neutral gas pressure in front of the target. The energy flux at the target decreases in the process of attaining the detached state. This work was performed with the support and under the auspices of the NIFS Collaboration Research programs NIFS14KNXN279 and NIFS14KNSS059.

  13. Surface morphology evolution in silicon during ion beam processing

    SciTech Connect

    Bedrossian P; Caturla, M; Diaz de la Rubia, T; Johnson, M

    1999-08-01

    of predictive process simulators. The results were then used to develop kinetic Monte Carlo simulations that, when coupled to molecular dynamics studies, could be used to study and compare the long time and length scale behavior of ion implanted silicon to the predictions of experiments. The results of these kinetic Monte Carlo simulations were validated with experimental data and then used to predict boron activation fractions during annealing of ion implanted silicon under conditions similar to those encountered in the semiconductor manufacturing environment. The success of the work and promise of the approach are reflected in the number of publication and in the fact that following completion of the project we signed a funds-in CRADA with Intel corporation and Applied Materials Corporation to continue the research.

  14. Simplified power processing for inert gas ion thrusters

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Pinero, L. R.; Hamley, J. A.

    1993-01-01

    Significant simplifications to power processors for inert gas ion thrusters in the 1 to 5 kW range have been identified. They include elimination of all but three power supplies - one each for the neutralizer, main discharge, and beam. The neutralizer and discharge power supplies would provide both cathode heating and plasma generating functions. This dual-use power supply concept was validated via integration tests with a 30 cm diameter xenon ion thruster. The beam/accelerator power supply would have positive and negative outputs to allow a single power supply to provide both functions. The discharge and beam power supplies would incorporate full-bridge inverters similar to those proven for flight-ready arcjet propulsion systems. Operation of this simplified power processing scheme at an inverter frequency of 50 kHz results in a projected power processor design with low mass and high efficiency. A 2 kW reference point design has estimated values of specific mass of 5.4 kg/kW and an efficiency of 93 percent.

  15. Choroidal detachment and ocular hypotony: CT evaluation

    SciTech Connect

    Mafee, M.F.; Peyman, G.A.

    1984-12-01

    The computed tomographic (CT) findings in 20 patients with hemorrhagic choroidal detachment, serous choroidal detachment and/or ocular hypotony are described. Hemorrhagic choroidal detachment appeared as an area of high attenuation that was usually localized, uniformly hyperdense, and not position-dependent. Serous choroidal detachment appeared as a convex, thick line of increased density within the vitreous cavity. Inflammatory choroidal detachment produces a diffuse intrauveal and suprachoroidal accumulation of high-density, position-dependent fluid, and uveoscleral thickening and enhancement, which in cross section resembles a ring. CT has proved valuable in localizing and differentiating serous or hemorrhagic choroidal detachment and uveoscleral infolding.

  16. SOLPS5.1 analysis of detachment with drifts and gas pumping effects in EAST

    NASA Astrophysics Data System (ADS)

    Du, Hailong; Sang, Chaofeng; Wang, Liang; Bonnin, Xavier; Guo, Houyang; Sun, Jizhong; Wang, Dezhen

    2016-08-01

    The aim of this paper is to estimate the effects of usual drifts and gas puffing/pumping locations on divertor detachment and Ar ion transport in the Experimental Advanced Superconducting Tokamak (EAST) by using the edge plasma code package SOLPS5.1. The simulated results reveal that which target plate first detaches depends strongly on the usual drifts, but not on the location of impurity gas puffing, which could be one of the possible explanations for the experimentally observed phenomenon (Chen et al 2013 Phys. Plasmas 20 022311) that the lower inner target first detached compared to the lower outer target with the lower outer gas puffing. The physics behind this phenomenon is that drifts not only can induce background ion flux, plasma density and temperature redistribution in the scrape-off layer (SOL) and divertor region, but also can change the Ar impurity force balance leading to Ar ions being dragged from bottom to top. Furthermore, the simulated results illustrate that the Ar ion transport in the SOL and divertor region is similar for different gas puffing locations including upstream and divertor region before partial detachment. However, the Ar ions penetrate into the core more easily, giving rise to more discharge disruption during complete detachment with upstream gas puffing than with divertor region puffing. Finally, we also estimate the effect of gas pumping on the detachment in order to realize long-pulse partial detachment in EAST. The results indicate that long-pulse partial detachment could be obtained by improving the pumping speed to match the puffing speed in case the excess Ar atoms accumulate in the core plasma during partial detachment in EAST.

  17. All-ion-implantation process for integrated circuits

    NASA Technical Reports Server (NTRS)

    Woo, D. S.

    1979-01-01

    Simpler than diffusion fabrication, ion bombardment produces complementary-metal-oxide-semiconductor / silicon-on-sapphire (CMOS/SOS) circuits that are one-third faster. Ion implantation simplifies the integrated circuit fabrication procedure and produces circuits with uniform characteristics.

  18. Process for improving moisture resistance of epoxy resins by addition of chromium ions

    NASA Technical Reports Server (NTRS)

    St.clair, A. K.; Stoakley, D. M.; St.clair, T. L.; Singh, J. J. (Inventor)

    1985-01-01

    A process for improving the moisture resistance properties of epoxidized TGMDA and DGEBA resin system by chemically incorporating chromium ions is described. The addition of chromium ions is believed to prevent the absorption of water molecules.

  19. Detached Breakwaters for Shore Protection.

    DTIC Science & Technology

    1986-01-01

    Presque Isle , Pennsylvania . . . 13 6Detached breakwater at Venice, California .. ............. 15& 7 Shoreline response to...at Presque Isle , Pennsylvania .. ...... 24 *13 Breakwater project at Colonial Beach , Virginia. ........... 27 14 Small recreational beach project at...in Pope and Rowen (1983). Presque Isle , Pennsylvania 23. At Presque Isle on Lake Erie , a segmented system of over 50 de- tached breakwaters is

  20. The mechanics of retinal detachment

    NASA Astrophysics Data System (ADS)

    Chou, Tom; Siegel, Michael

    2013-03-01

    We present a model of the mechanical and fluid forces associated with exudative retinal detachments where the retinal photoreceptor cells separate typically from the underlying retinal pigment epithelium (RPE). By computing the total fluid volume flow arising from transretinal, vascular, and retinal pigment epithelium (RPE) pump currents, we determine the conditions under which the subretinal fluid pressure exceeds the maximum yield stress holding the retina and RPE together, giving rise to an irreversible, extended retinal delamination. We also investigate localized, blister-like retinal detachments by balancing mechanical tension in the retina with both the retina-RPE adhesion energy and the hydraulic pressure jump across the retina. For detachments induced by traction forces, we find a critical radius beyond which the blister is unstable to growth. Growth of a detached blister can also be driven by inflamed tissue within which e.g., the hydraulic conductivities of the retina or choroid increase, the RPE pumps fail, or the adhesion properties change. We determine the parameter regimes in which the blister either becomes unstable to growth, remains stable and finite-sized, or shrinks, allowing possible healing. This work supported by the Army Research Office through grant 58386MA

  1. IMPACT OF THE SMALL COLUMN ION EXCHANGE PROCESS ON THE DEFENSE WASTE PROCESSING FACILITY - 12112

    SciTech Connect

    Koopman, D.; Lambert, D.; Fox, K.; Stone, M.

    2011-11-07

    The Savannah River Site (SRS) is investigating the deployment of a parallel technology to the Salt Waste Processing Facility (SWPF, presently under construction) to accelerate high activity salt waste processing. The proposed technology combines large waste tank strikes of monosodium titanate (MST) to sorb strontium and actinides with two ion exchange columns packed with crystalline silicotitanate (CST) resin to sorb cesium. The new process was designated Small Column Ion Exchange (SCIX), since the ion exchange columns were sized to fit within a waste storage tank riser. Loaded resins are to be combined with high activity sludge waste and fed to the Defense Waste Processing Facility (DWPF) for incorporation into the current glass waste form. Decontaminated salt solution produced by SCIX will be fed to the SRS Saltstone Facility for on-site immobilization as a grout waste form. Determining the potential impact of SCIX resins on DWPF processing was the basis for this study. Accelerated salt waste treatment is projected to produce a significant savings in the overall life cycle cost of waste treatment at SRS.

  2. Plasma processing of spent nuclear fuel by two-frequency ion cyclotron resonance heating

    SciTech Connect

    Timofeev, A. V.

    2009-11-15

    A previously developed method for analyzing the plasma processing of spent nuclear fuel is generalized to a plasma containing multicharged fuel ions. In such a plasma, ion cyclotron resonance heating of nuclear ash ions should be carried out in two monochromatic RF fields of different frequencies, provided that the fraction of {xi} multicharged ions is small, {xi} {<=} 0.1, a condition that substantially restricts the productivity of systems for processing spent nuclear fuel. Ways of overcoming this difficulty are discussed.

  3. Space processing applications of ion beam technology. [surface finishing, welding, milling and film deposition

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.

    1977-01-01

    Ion thruster engines for spacecraft propulsion can serve as ion beam sources for potential space processing applications. The advantages of space vacuum environments and the possible gravity effects on thruster ion beam materials operations such as thin film growth, ion milling, and surface texturing were investigated. The direct gravity effect on sputter deposition and vapor deposition processes are discussed as well as techniques for cold and warm welding.

  4. Removal of heavy metal ions from oil shale beneficiation process water by ferrite process

    SciTech Connect

    Mehta, R.K.; Zhang, L.; Lamont, W.E.; Schultz, C.W.

    1991-12-31

    The ferrite process is an established technique for removing heavy metals from waste water. Because the process water resulting from oil shale beneficiation falls into the category of industrial waste water, it is anticipated that this process may turn out to be a potential viable treatment for oil shale beneficiation process water containing many heave metal ions. The process is chemoremedial because not only effluent water comply with quality standards, but harmful heavy metals are converted into a valuable, chemically stable by-product known as ferrite. These spinel ferrites have magnetic properties, and therefore can be use in applications such as magnetic marker, ferrofluid, microwave absorbing and scavenging material. Experimental results from this process are presented along with results of treatment technique such as sulfide precipitation.

  5. Removal of heavy metal ions from oil shale beneficiation process water by ferrite process

    SciTech Connect

    Mehta, R.K.; Zhang, L.; Lamont, W.E.; Schultz, C.W. . Mineral Resources Inst.)

    1991-01-01

    The ferrite process is an established technique for removing heavy metals from waste water. Because the process water resulting from oil shale beneficiation falls into the category of industrial waste water, it is anticipated that this process may turn out to be a potential viable treatment for oil shale beneficiation process water containing many heave metal ions. The process is chemoremedial because not only effluent water comply with quality standards, but harmful heavy metals are converted into a valuable, chemically stable by-product known as ferrite. These spinel ferrites have magnetic properties, and therefore can be use in applications such as magnetic marker, ferrofluid, microwave absorbing and scavenging material. Experimental results from this process are presented along with results of treatment technique such as sulfide precipitation.

  6. Detached Growth of Germanium by Directional Solidification

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Volz, M. P.; Cobb, S.; Motakef, S.; Szofran, F. R.

    2004-01-01

    The conditions of detached solidification under controlled pressure differential across the meniscus were investigated. Uncoated and graphite- or BN-coated silica and pBN crucibles were used. Detached and partly detached growth was achieved in pBN and BN-coated crucibles, respectively. The results of the experiments are discussed based on the theory of Duffar et al.

  7. Detached Growth of Germanium by Directional Solidification

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Volz, M. P.; Cobb, S.; Motakef, S.; Szofran, F. R.

    2004-01-01

    The conditions of detached solidification under controlled pressure differential across the meniscus were investigated. Uncoated and graphite- or BN-coated silica and pBN crucibles were used. Detached and partly detached growth was achieved in pBN and BN-coated crucibles, respectively. The results of the experiments are discussed based on the theory of Duffar et al.

  8. Kinematic Fitting of Detached Vertices

    SciTech Connect

    Mattione, Paul

    2007-05-01

    The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

  9. Correlation between the shape of the ion mobility signals and the stepwise folding process of polylactide ions.

    PubMed

    Duez, Q; Josse, T; Lemaur, V; Chirot, F; Choi, C M; Dubois, P; Dugourd, P; Cornil, J; Gerbaux, P; De Winter, J

    2017-03-01

    In the field of polymer characterization, the use of ion mobility mass spectrometry (IMMS) remains mainly devoted to the temporal separation of cationized oligomers according to their charge states, molecular masses and macromolecular architectures in order to probe the presence of different structures. When analyzing multiply charged polymer ions by IMMS, the most striking feature is the observation of breaking points in the evolution of the average collision cross sections with the number of monomer units. Those breaking points are associated to the folding of the polymer chain around the cationizing agents. Here, we scrutinize the shape of the arrival time distribution (ATD) of polylactide ions and associate the broadening as well as the loss of symmetry of the ATD signals to the coexistence of different populations of ions attributed to the transition from opened to folded stable structures. The observation of distinct distributions reveals the absence of folded/extended structure interconversion on the ion mobility time scale (1-10 ms) and then on the lifetime of ions within the mass spectrometer at room temperature. In order to obtain information on the possible interconversion between the different observed populations upon ion activation, we performed IM-IM-MS experiments (tandem ion mobility measurements). To do so, mobility-selected ions were activated by collisions before a second mobility measurement. Interestingly, the conversion by collisional activation from a globular structure into a (partially) extended structure, i.e. the gas phase unfolding of the ions, was not observed in the energetic regime available with the used experimental setup. The absence of folded/extended interconversion, even upon collisional activation, points to the fact that the polylactide ions are 'frozen' in their specific 3D structure during the desolvation/ionization electrospray processes. Copyright © 2017 John Wiley & Sons, Ltd.

  10. A study on the TAE-induced fast-ion loss process in LHD

    NASA Astrophysics Data System (ADS)

    Ogawa, K.; Isobe, M.; Toi, K.; Shimizu, A.; Spong, D. A.; Osakabe, M.; Yamamoto, S.; the LHD Experiment Group

    2013-05-01

    Characteristics of fast-ion losses induced by toroidal-Alfvén eigenmodes (TAEs) are investigated over wide parameter ranges of Large Helical Device (LHD) plasmas to reveal the fast-ion loss process. To study fast-ion losses, a scintillator-based lost-fast ion probe is used, and an increment of fast-ion loss flux due to TAEs from the neoclassical orbit loss level (ΔΓfast ion) is measured. The dependence of ΔΓfast ion on the TAE magnetic fluctuation amplitude (bθTAE) changes from a linear to a quadratic and finally a third power with an increase in the magnetic axis shift. It is found that the dependence of fast-ion loss flux on TAE magnetic fluctuation amplitudes changes at a certain fluctuation level in a fixed configuration. Experimental results show that in the small bθTAE regime, ΔΓfast ion is proportional to bθTAE, whereas ΔΓfast ion increases with the square of bθTAE in the larger bθTAE regime. A simulation by orbit-following codes that incorporate magnetic fluctuations with frequency chirping-down due to TAEs suggests the change in the fast-ion loss process from a convective (ΔΓfast ion ∝ bθTAE) to a diffusive (\\Delta \\Gamma_{fast\\ ion} \\propto b_{\\theta TAE}^{2} ) character as bθTAE increases.

  11. Unconventional secretory processing diversifies neuronal ion channel properties

    PubMed Central

    Hanus, Cyril; Geptin, Helene; Tushev, Georgi; Garg, Sakshi; Alvarez-Castelao, Beatriz; Sambandan, Sivakumar; Kochen, Lisa; Hafner, Anne-Sophie; Langer, Julian D; Schuman, Erin M

    2016-01-01

    N-glycosylation – the sequential addition of complex sugars to adhesion proteins, neurotransmitter receptors, ion channels and secreted trophic factors as they progress through the endoplasmic reticulum and the Golgi apparatus – is one of the most frequent protein modifications. In mammals, most organ-specific N-glycosylation events occur in the brain. Yet, little is known about the nature, function and regulation of N-glycosylation in neurons. Using imaging, quantitative immunoblotting and mass spectrometry, we show that hundreds of neuronal surface membrane proteins are core-glycosylated, resulting in the neuronal membrane displaying surprisingly high levels of glycosylation profiles that are classically associated with immature intracellular proteins. We report that while N-glycosylation is generally required for dendritic development and glutamate receptor surface expression, core-glycosylated proteins are sufficient to sustain these processes, and are thus functional. This atypical glycosylation of surface neuronal proteins can be attributed to a bypass or a hypo-function of the Golgi apparatus. Core-glycosylation is regulated by synaptic activity, modulates synaptic signaling and accelerates the turnover of GluA2-containing glutamate receptors, revealing a novel mechanism that controls the composition and sensing properties of the neuronal membrane. DOI: http://dx.doi.org/10.7554/eLife.20609.001 PMID:27677849

  12. Hexuronic acid stereochemistry determination in chondroitin sulfate glycosaminoglycan oligosaccharides by electron detachment dissociation.

    PubMed

    Leach, Franklin E; Ly, Mellisa; Laremore, Tatiana N; Wolff, Jeremy J; Perlow, Jacob; Linhardt, Robert J; Amster, I Jonathan

    2012-09-01

    Electron detachment dissociation (EDD) has previously provided stereo-specific product ions that allow for the assignment of the acidic C-5stereochemistry in heparan sulfate glycosaminoglycans (GAGs), but application of the same methodology to an epimer pair in the chondroitin sulfate glycoform class does not provide the same result. A series of experiments have been conducted in which glycosaminoglycan precursor ions are independently activated by electron detachment dissociation (EDD), electron induced dissociation (EID), and negative electron transfer dissociation (NETD) to assign the stereochemistry in chondroitin sulfate (CS) epimers and investigate the mechanisms for product ion formation during EDD in CS glycoforms. This approach allows for the assignment of electronic excitation products formed by EID and detachment products to radical pathways in NETD, both of which occur simultaneously during EDD. The uronic acid stereochemistry in electron detachment spectra produces intensity differences when assigned glycosidic and cross-ring cleavages are compared. The variations in the intensities of the doubly deprotonated (0,2)X(3) and Y(3) ions have been shown to be indicative of CS-A/DS composition during the CID of binary mixtures. These ions can provide insight into the uronic acid composition of binary mixtures in EDD, but the relative abundances, although reproducible, are low compared with those in a CID spectrum acquired on an ion trap. The application of principal component analysis (PCA) presents a multivariate approach to determining the uronic acid stereochemistry spectra of these GAGs by taking advantage of the reproducible peak distributions produced by electron detachment.

  13. Unresolved problems in cesiation processes of negative hydrogen ion sources

    NASA Astrophysics Data System (ADS)

    Wada, Motoi

    2013-09-01

    Attempts are being made to optimize negative hydrogen (H-) ion current by introducing Cs into an ion source, but there are some unanswered questions in properly handling Cs to realize stable extraction of H- ion beams. For example, Cs amount to optimize H- production often becomes much larger than the amount predicted to realize partial monolayer of Cs on the source wall. Additional charge of Cs into a source to recover reduced H- current by continuous operation does not necessarily realize the original value. Beam intensity of H- changes with the impurity content in the ion source. The purpose of the present paper is to list up these uncertainties and unknown factors in negative ion source performance operated with Cs. The paper tries to identify possible mechanisms causing these problems by running a simulation code ACAT (Atomic Collision in Amorphous Target). The code predicts that glancing injection of hydrogen ions doubles the numbers of both reflection coefficients and ion induced desorption yields from those for the normal incidence. It also indicates smaller hydrogen desorption yields for thick layer of adsorbed hydrogen on the surface. These results are compared with experimental data obtained in UHV conditions.

  14. Pre-equilibrium decay processes in energetic heavy ion reactions

    SciTech Connect

    Blann, M.

    1986-04-15

    The Boltzmann master equation (BME) is defined for application to precompound decay in heavy ion reactions in the 10 100 MeV/nucleon regime. Predicted neutron spectra are compared with measured results for central collisions of /sup 20/Ne and /sup 12/C with /sup 165/Ho target nuclei. Comparisons are made with subthreshold ..pi../sup 0/ yields in heavy ion reactions between 35 and 84 MeV/nucleon, and with the ..pi../sup 0/ spectra. The BME is found to be an excellent tool for investigating these experimentally observed aspects of non-equilibrium heavy ion reactions. 18 refs., 8 figs.

  15. Relevant ion time scales for electron impact processes of atoms in dense plasmas

    SciTech Connect

    Murillo, M.S.

    1997-12-31

    In this paper a new model for treating collisional atomic processes has been presented. This model simultaneously and self-consistently treats electron and ion processes. For transitions frequencies above the ion plasma frequency, it is argued that little ion motion occurs although the interaction is still strong; the ion microfield perturbs the atom. The electron impact processes may still be described by a DSF between levels of the perturbed atoms, suggesting the name Microfield Stochastic Model (MSM) for this method. Future work will be directed towards refining some of the approximations used here for application to realistic systems.

  16. Ion distribution measurements to probe target and plasma processes in electronegative magnetron discharges. II. Positive ions

    SciTech Connect

    Welzel, Th.; Ellmer, K.; Naumov, S.

    2011-04-01

    Spectra of the ion mass and energy distributions of positive ions in reactive (Ar/O{sub 2}) and nonreactive (Ar) dc magnetron sputtering discharges have been investigated by energy-resolved mass spectrometry. The results of three sputter target materials, i.e., Cu, In, and W are compared to each other. Besides the main gas constituents, mass spectra reveal a variety of molecular ions which are dependent on the target material. In reactive mode, ArO{sup +} is always observed in Ar/O{sub 2} but molecules containing Ar and the metal were exclusively found for the Cu target. The occurrence of the different ions is explained in the context of their bond strengths obtained from density functional theory calculations. The energy spectra generally contain the known low-energy peak corresponding to the plasma potential. Differently extended high-energy tails due to sputtered material were observed for the different targets. Besides these, high-energetic ions were detected with up to several 100 eV. Their energies are significantly different for Ar{sup +} and O{sup +} with Ar{sup +} strongly depending on the target material. The spectra are discussed together with results from transport of ions in matter (TRIM) calculation to elucidate the origin of these energetic ions.

  17. Characterization of secondary ion emission processes of sub-MeV C60 ion impacts via analysis of statistical distributions of the emitted ion number

    NASA Astrophysics Data System (ADS)

    Hirata, K.; Yamada, K.; Chiba, A.; Narumi, K.; Saitoh, Y.

    2016-12-01

    We report probability distributions of the number of secondary ions (SIs) emitted by sub-MeV C60 ion impacts on an organic polymer target and the characterization of their emission processes through the analysis of the distributions. The probability distributions were obtained by analyzing experimental SI counting data obtained by a time-of-flight SI mass spectrometer combined with pulsed primary ion beams, using an analytical model developed to derive the distributions from the experimental data. A series of probability distribution functions was investigated for ion impacts of C60 with sub-MeV energies (0.12-0.54 MeV), which can provide sufficient SIs per impact to determine the functions. Their complicated and undefined SI emission processes were characterized based on the determined functions.

  18. The Use of Ion Implantation for Materials Processing.

    DTIC Science & Technology

    1984-08-23

    Oxidized samples were studied using Rutherford backscattering, nuclear reaction analysis, Auger spectroscopy , secondary-ion mass spectroscopy , X-ray...attributable to sputtering. Auger spectroscopy showed that vacuum carburization of both carbide and matrix phases of the Stoody alloy occurred during...films and surface alloys formed by ion im,Iantation were determined by X-ray Photoelectron Spectroscopy (XPS) aril Auger Electron Specrroscopy (AES

  19. Binding of alkali metal ions by cyclic polyethers: significance in ion transport processes.

    PubMed

    Izatt, R M; Rytting, J H; Nelson, D P; Haymore, B L; Christensen, J J

    1969-04-25

    Values for the formation constant (log K), the change in enthalpy (triangle upH degrees ), and the change in entropy (triangle upS degrees ) have been determined for the interaction of lithium, sodium, potassium, rubidium, and cesium ions with the two isomers of the cyclic polyether, 2,5,8,15,18,21-hexaoxatricyclo[20.4.0.0(9,14)] hexacosane. The stability order of these metal ions with either isomer is identical to the permeability order for these same metal ions with the structurally related antibiotics, valinomycin and monactin.

  20. Numerical Investigation of Plasma Detachment in Magnetic Nozzle Experiments

    NASA Technical Reports Server (NTRS)

    Sankaran, Kamesh; Polzin, Kurt A.

    2008-01-01

    At present there exists no generally accepted theoretical model that provides a consistent physical explanation of plasma detachment from an externally-imposed magnetic nozzle. To make progress towards that end, simulation of plasma flow in the magnetic nozzle of an arcjet experiment is performed using a multidimensional numerical simulation tool that includes theoretical models of the various dispersive and dissipative processes present in the plasma. This is an extension of the simulation tool employed in previous work by Sankaran et al. The aim is to compare the computational results with various proposed magnetic nozzle detachment theories to develop an understanding of the physical mechanisms that cause detachment. An applied magnetic field topology is obtained using a magnetostatic field solver (see Fig. I), and this field is superimposed on the time-dependent magnetic field induced in the plasma to provide a self-consistent field description. The applied magnetic field and model geometry match those found in experiments by Kuriki and Okada. This geometry is modeled because there is a substantial amount of experimental data that can be compared to the computational results, allowing for validation of the model. In addition, comparison of the simulation results with the experimentally obtained plasma parameters will provide insight into the mechanisms that lead to plasma detachment, revealing how they scale with different input parameters. Further studies will focus on modeling literature experiments both for the purpose of additional code validation and to extract physical insight regarding the mechanisms driving detachment.

  1. Influence of hard water ions on the growth of salmonella in poultry processing water

    USDA-ARS?s Scientific Manuscript database

    The influence of magnesium and calcium ions in process water on the growth of Salmonella was evaluated and related to the contamination in process wastewater. Salmonella typhimurium was grown in the laboratory and exposed to 500 mg/kg and 1000 mg/kg of magnesium and calcium ions to simulate hard pr...

  2. Microfabricated Surface-Electrode Ion Trap for Scalable Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Seidelin, S.; Chiaverini, J.; Reichle, R.; Bollinger, J. J.; Leibfried, D.; Britton, J.; Wesenberg, J. H.; Blakestad, R. B.; Epstein, R. J.; Hume, D. B.; Itano, W. M.; Jost, J. D.; Langer, C.; Ozeri, R.; Shiga, N.; Wineland, D. J.

    2006-06-01

    Individual laser-cooled Mg+24 ions are confined in a linear Paul trap with a novel geometry where gold electrodes are located in a single plane and the ions are trapped 40μm above this plane. The relatively simple trap design and fabrication procedure are important for large-scale quantum information processing (QIP) using ions. Measured ion motional frequencies are compared to simulations. Measurements of ion recooling after cooling is temporarily suspended yield a heating rate of approximately 5 motional quanta per millisecond for a trap frequency of 2.83 MHz, sufficiently low to be useful for QIP.

  3. Induction of hyper-adhesion attenuates autoimmune-induced keratinocyte cell-cell detachment and processing of adhesion molecules via mechanisms that involve PKC.

    PubMed

    Cirillo, Nicola; Lanza, Alessandro; Prime, Stephen S

    2010-02-15

    In confluent keratinocyte monolayers, desmosomal adhesion gradually becomes calcium-independent and this is associated with an increase in the strength of intercellular adhesion (hyper-adhesion). In this study, we investigated the functional and molecular significance of hyper-adhesion in a system challenged by autoimmune sera from patients with Pemphigus Vulgaris (PV), a disease primarily targeting desmosomal adhesion. The results show that keratinocytes with calcium-independent desmosomes are resistant to disruption of intercellular contacts (acantholysis) in experimental PV. Furthermore, both the desmosomal cadherins desmoglein (Dsg) 1 and Dsg3 and the adherens junction protein E-cadherin were decreased in confluent keratinocytes at Day 1, but not in hyper-adhesive cells (Day 6) after incubation with PV serum. Pharmacological induction of the hyper-adhesive state with the PKC inhibitor Go6976 reduced both the acantholysis rate and the processing of cell adhesion molecules induced by PV serum. When the establishment of the hyper-adhesive state was prevented by cell adhesion recognition (CAR) peptides that perturbed desmosomal interactions, Go6976 could still partially attenuate PV acantholysis. Taken together, these data demonstrate that keratinocyte hyper-adhesion decreases the morphological, functional and biochemical dys-cohesive effects of PV serum via mechanisms that involve, at least in part, the function of PKC. This suggests that reinforcing keratinocyte adhesion may be a promising way to inhibit the effects of this most debilitating disorder. Crown Copyright 2009. Published by Elsevier Inc. All rights reserved.

  4. Crystal Shape Evolution in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2013-01-01

    Detached (or dewetted) Bridgman crystal growth defines that process in which a gap exists between a growing crystal and the crucible wall. Existence of the gap provides several advantages, including no sticking of the crystal to the crucible wall, reduced thermal and mechanical stresses, reduced dislocations, and no heterogeneous nucleation by the crucible. Numerical calculations are used to determine the conditions in which a gap can exist. According to crystal shape stability theory, only some of these gap widths will be dynamically stable. Beginning with a crystal diameter that differs from stable conditions, the transient crystal growth process is analyzed. In microgravity, dynamic stability depends only on capillary effects and is decoupled from heat transfer. Depending on the initial conditions and growth parameters, the crystal shape will evolve towards the crucible wall, towards a stable gap width, or towards the center of the crucible, collapsing the meniscus. The effect of a tapered crucible on dynamic stability is also described

  5. Crystal Shape Evolution in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2013-01-01

    Detached (or dewetted) Bridgman crystal growth defines that process in which a gap exists between a growing crystal and the crucible wall. Existence of the gap provides several advantages, including no sticking of the crystal to the crucible wall, reduced thermal and mechanical stresses, reduced dislocations, and no heterogeneous nucleation by the crucible. Numerical calculations are used to determine the conditions in which a gap can exist. According to crystal shape stability theory, only some of these gap widths will be dynamically stable. Beginning with a crystal diameter that differs from stable conditions, the transient crystal growth process is analyzed. In microgravity, dynamic stability depends only on capillary effects and is decoupled from heat transfer. Depending on the initial conditions and growth parameters, the crystal shape will evolve towards the crucible wall, towards a stable gap width, or towards the center of the crucible, collapsing the meniscus. The effect of a tapered crucible on dynamic stability is also described.

  6. Dynamic processes in heavy-ion collisions at intermediate energies

    NASA Astrophysics Data System (ADS)

    Prendergast, E. P.

    1999-03-01

    This thesis describes the study of the reaction dynamics in heavy-ion collisions of small nuclear systems at intermediate energies. For this, experiments were performed of 24Mg+27A1 at 45 and 95 AMeV. The experiments described in this thesis were performed at the GANIL accelerator facility in Caeri (France) using the Huygens detectors in conjunction with the ‘MUR’. The Huygens detectors consist of the CsI(Tl)-Wall (CIW) covering the backward hemisphere and, located at mid-rapidity, the central trigger detector (CTD), a gas chamber with microstrip read-out backed by 48 plastic scintillators. The forward region is covered by 16 of the plastic scintillators of the CTD and by the MUR, a time-of-flight wall consisting of 96 plastic scintillator sheets. In earlier experiments only fragments with atomic number, Z, greater then two could be identifled in the CTD. Therefore, an investigation was done into the properties of different drift gases. The use of freon (CF4) in the drift chamber, combined with an increase of the gas pressure to 150 mbar, makes it possible to identify all particles with Z ≥ 2. Under these conditions particles with Z = 1 can only be identifled to approximately 25 AMeV. The Isospin Quantum Molecular Dynamics (IQMD) model has been used, to interpret the measured data. This model gives a microscopical description of heavy-ion collisions and simulates collisions on an event by event basis. In IQMD all protons and neutrons are represented as individual Gaussian wave packets. After initialisation the path of each nucleon is calculated for 200 fm/c, after which the simulation is stopped. At this time, nucleons which are close in space are clustered into fragments. The events generated by IQMD can then be processed by a GEANT detector simulation. This calculation takes into account the effects of the detector on the incoming particles. By using the GEANT simulation it is possible to give a direct comparison between the results of IQMD and the

  7. In Situ Investigations of Ion Exchange Processes in Microporous Materials

    NASA Astrophysics Data System (ADS)

    Lee, Y.; Parise, J. B.; Hanson, J. C.

    2001-12-01

    The mechanism by which ions exchange in microporous and layered solids, such as zeolites and clays for example, has important implications in areas as diverse as soil fertility and environmental remediation. A detailed characterization of the ion-exchange pathway, the structural consequences of ion exchange and the specific sites involved in the course of exchange, is desirable. A probe that is both time- and structure-sensitive allows resolution of which specific sites are involved, along with the effects of different cation types on the uptake and release of ions. In order to discern the mechanism of ion exchange, it is necessary not only to observe the course of the reaction, which can now be done routinely using energy dispersive X-ray diffraction at synchrotron sources, but also to collect dynamic diffraction data of sufficient quality to allow structure refinement using Rietveld structure refinement techniques. This at present requires the collection of monochromatic data. Tradeoffs between time-resolution, peak-to-background discrimination and structural resolution are often required and depend on the problem at hand. We have developed a number of strategies for in situ ion exchange techniques that probe both structural and kinetic information from dynamic solid media. Examples include investigations of the site-specific ion-exchange mechanism in zeolite LSX using a combination of ex situ and in situ time-resolved synchrotron X-ray powder diffraction, Iterative Target Transformation Factor Analysis (ITTFA) and Rietveld structural refinements. Measurement of competitive ion depletion curves showed that the newly synthesized gallosilicate TsG-1 is more selective for Sr than mineral clinoptilolite, and the structural pathway of Sr-exchange in TsG-1 was monitored by in situ and ex situ synchrotron X-ray powder diffraction. In those cases where full structure refinement is desirable using less than optimal powder diffraction data, we found it necessary to first

  8. Micro structure processing on plastics by accelerated hydrogen molecular ions

    NASA Astrophysics Data System (ADS)

    Hayashi, H.; Hayakawa, S.; Nishikawa, H.

    2017-08-01

    A proton has 1836 times the mass of an electron and is the lightest nucleus to be used for accelerator in material modification. We can setup accelerator with the lowest acceleration voltage. It is preferable characteristics of Proton Beam Writer (PBW) for industrial applications. On the contrary ;proton; has the lowest charge among all nuclei and the potential impact to material is lowest. The object of this research is to improve productivity of the PBW for industry application focusing on hydrogen molecular ions. These ions are generated in the same ion source by ionizing hydrogen molecule. There is no specific ion source requested and it is suitable for industrial use. We demonstrated three dimensional (3D) multilevel micro structures on polyester base FPC (Flexible Printed Circuits) using proton, H2+ and H3+. The reactivity of hydrogen molecular ions is much higher than that of proton and coincident with the level of expectation. We can apply this result to make micro devices of 3D multilevel structures on FPC.

  9. Soil detachment by overland flow under different vegetation restoration models in the loess plateau of China

    USDA-ARS?s Scientific Manuscript database

    Land use change has significant effects on soil properties and vegetation cover and thus probably affects soil detachment by overland flow. Few studies were conducted to evaluate the effect of restoration models on the soil detachment process in the Loess Plateau in the past decade during which a Gr...

  10. Silicon surface-electrode ion traps for quantum information processing

    NASA Astrophysics Data System (ADS)

    Doret, S. Charles; Slusher, Richart

    2010-03-01

    The Georgia Tech Research Institute (GTRI) is designing, building, and testing scalable surface-electrode ion traps for quantum information applications, fabricated using silicon VLSI technology. A wide range of trap architectures have been developed, including a linear trap capable of holding long chains of equally spaced ions, a 90-degree X-junction, and an integrated micromirror with collection efficiency approaching 20%. Fabrication features that can be integrated with the surface electrodes include multilayer interconnects, optics for enhanced light collection, flexible optical access through beveled slots extending through the substrate, and recessed wire bonds for clear laser access across the trap surface. Traps are designed at GTRI using in-house codes that calculate trap fields, compute the full motion of ions confined in the trap, including micromotion, and optimize electrode shapes and transport waveforms using genetic algorithms. We will present designs and initial test results for several of these traps, as well as plans for their use in future experiments.

  11. Theoretical investigations of plasma processes in the ion bombardment thruster

    NASA Technical Reports Server (NTRS)

    Wilhelm, H. E.

    1975-01-01

    A physical model for a thruster discharge was developed, consisting of a spatially diverging plasma sustained electrically between a small ring cathode and a larger ring anode in a cylindrical chamber with an axial magnetic field. The associated boundary-value problem for the coupled partial differential equations with mixed boundary conditions, which describe the electric potential and the plasma velocity fields, was solved in closed form. By means of quantum-mechanical perturbation theory, a formula for the number S(E) of atoms sputtered on the average by an ion of energy E was derived from first principles. The boundary-value problem describing the diffusion of the sputtered atoms through the surrounding rarefied electron-ion plasma to the system surfaces of ion propulsion systems was formulated and treated analytically. It is shown that outer boundary-value problems of this type lead to a complex integral equation, which requires numerical resolution.

  12. Cluster ion beam process technology 20 years of R&D history

    NASA Astrophysics Data System (ADS)

    Yamada, Isao

    2007-04-01

    More than 20 years have passed since the author first began to explore the feasibility of processing by gas cluster ion beams at the Ion Beam Engineering Experimental Laboratory of Kyoto University. Processes employing ions of gaseous material clusters comprised of a few hundred to many thousand atoms are now being developed into a new field of ion beam technology. Cluster-surface collisions produce important non-linear effects which are being applied to shallow junction formation, to etching and smoothing of semiconductors, metals and dielectrics, to assisted formation of thin films with nano-scale accuracy and to other surface modification applications.

  13. The Use of Ion Implantation for Materials Processing.

    DTIC Science & Technology

    1981-06-24

    the Pourbaix diagram ’" for palladium at 25’C as an approximate guide, at zero pH Pd is polarized from a region of immunity into one of corrosion for...to match that of the silicon nitride layers. the most direct indicator was implanted nitrogen ions. To permit calculation of the formation of an...from a reacted, e.g., nitrided , surface layer, or from a more stable microstructure, e.g., nitrogen-stabilized austenite. D. The Effect of Ion

  14. Bacterial detachment from salivary conditioning films by dentifrice supernates.

    PubMed

    van der Mei, Henny C; White, Donald J; Cox, Ed R; Geertsema-Doornbusch, Gesinda I; Busscher, Henk J

    2002-01-01

    This study compared the detachment by supernates of nine different dentifrices of four oral bacterial strains adhering to a salivary pellicle in a parallel plate flow chamber. Ultra-thin bovine enamel slabs were coated for 1.5 h with human whole saliva. Following buffer rinsing, a bacterial suspension of Streptococcus oralis, Streptococcus sanguis, Streptococcus mutans or Actinomyces naeslundii was perfused through the flow chamber at a shear rate of 30 s-1 for four hours, and the number of adhering bacteria n4h was enumerated by image analysis after buffer rinsing at the same shear rate. Then, a 25 wt%-dentifrice/water supernate was perfused through the flow chamber for four minutes, followed by eight minutes of buffer rinsing and another enumeration of the number of bacteria that had remained adhering nad. Finally, an air-bubble was passed through the flow chamber to mimic the occasionally high detachment forces occurring in the oral cavity, and the adhering bacteria nab were counted again. On average, S. sanguis was the easiest to detach (73% averaged over all dentifrice supernates), while A. naeslundii was the most difficult (22% on average). The combined detachment of bacteria by dentifrice supernates and air-bubble ranged from a low of 16% to a high of 80%. Dentifrices containing pyrophosphate and polymeric polyphosphate (hexametaphosphate) surface active ingredients appeared to produce the most consistent and strongest desorption effects on plaque bacteria. Factors apparently important to bacterial detachment from pellicle-covered tooth surfaces by dentifrice formulations include the nature of adhesion of bacterial strains and chemical composition of the dentifrice formulations, including pH, surfactant system and the effect of added ingredients (dispersants, metal ions, peroxides, baking soda).

  15. Negative ion production and beam extraction processes in a large ion source (invited)

    SciTech Connect

    Tsumori, K. Nakano, H.; Goto, M.; Nagaoka, K.; Osakabe, M.; Takeiri, Y.; Kaneko, O.; Ikeda, K.; Kisaki, M.; Geng, S.; Wada, M.; Sasaki, K.; Nishiyama, S.; Serianni, G.; Agostinetti, P.; Sartori, E.; Brombin, M.; Veltri, P.; Wimmer, C.

    2016-02-15

    Recent research results on negative-ion-rich plasmas in a large negative ion source have been reviewed. Spatial density and flow distributions of negative hydrogen ions (H{sup −}) and positive hydrogen ions together with those of electrons are investigated with a 4-pin probe and a photodetachment (PD) signal of a Langmuir probe. The PD signal is converted to local H{sup −} density from signal calibration to a scanning cavity ring down PD measurement. Introduction of Cs changes the slope of plasma potential local distribution depending upon the plasma grid bias. A higher electron density H{sub 2} plasma locally shields the bias potential and behaves like a metallic free electron gas. On the other hand, the bias and extraction electric fields penetrate in a Cs-seeded electronegative plasma even when the electron density is similar. Electrons are transported by the penetrated electric fields from the driver region along and across the filter and electron deflection magnetic fields. Plasma ions exhibited a completely different response against the penetration of electric fields.

  16. Characterization of silicon-gate CMOS/SOS integrated circuits processed with ion implantation

    NASA Technical Reports Server (NTRS)

    Woo, D. S.

    1977-01-01

    Progress in developing the application of ion implantation techniques to silicon gate CMOS/SOS processing is described. All of the conventional doping techniques such as in situ doping of the epi-film and diffusion by means of doped oxides are replaced by ion implantation. Various devices and process parameters are characterized to generate an optimum process by the use of an existing SOS test array. As a result, excellent circuit performance is achieved. A general description of the all ion implantation process is presented.

  17. Electrolytic process to produce sodium hypochlorite using sodium ion conductive ceramic membranes

    DOEpatents

    Balagopal, Shekar; Malhotra, Vinod; Pendleton, Justin; Reid, Kathy Jo

    2012-09-18

    An electrochemical process for the production of sodium hypochlorite is disclosed. The process may potentially be used to produce sodium hypochlorite from seawater or low purity un-softened or NaCl-based salt solutions. The process utilizes a sodium ion conductive ceramic membrane, such as membranes based on NASICON-type materials, in an electrolytic cell. In the process, water is reduced at a cathode to form hydroxyl ions and hydrogen gas. Chloride ions from a sodium chloride solution are oxidized in the anolyte compartment to produce chlorine gas which reacts with water to produce hypochlorous and hydrochloric acid. Sodium ions are transported from the anolyte compartment to the catholyte compartment across the sodium ion conductive ceramic membrane. Sodium hydroxide is transported from the catholyte compartment to the anolyte compartment to produce sodium hypochlorite within the anolyte compartment.

  18. Espisodic detachment of Martian crustal magnetic fields leading to bulk atmospheric plasma escape

    SciTech Connect

    Brain, D A; Baker, A H; Briggs, J; Eastwood, J P; Halekas, J S; Phan, T

    2009-06-02

    We present an analysis of magnetic field and suprathermal electron measurements from the Mars Global Surveyor (MGS) spacecraft that reveals isolated magnetic structures filled with Martian atmospheric plasma located downstream from strong crustal magnetic fields with respect to the flowing solar wind. The structures are characterized by magnetic field enhancements and rotations characteristic of magnetic flux ropes, and characteristic ionospheric electron energy distributions with angular distributions distinct from surrounding regions. These observations indicate that significant amounts of atmosphere are intermittently being carried away from Mars by a bulk removal process: the top portions of crustal field loops are stretched through interaction with the solar wind and detach via magnetic reconnection. This process occurs frequently and may account for as much as 10% of the total present-day ion escape from Mars.

  19. Space Plasma Ion Processing of Ilmenite in the Lunar Soil: Insights from In-Situ TEM Ion Irradiation Experiments

    NASA Technical Reports Server (NTRS)

    Christoffersen, R.; Keller, L. P.

    2007-01-01

    Space weathering on the moon and asteroids results largely from the alteration of the outer surfaces of regolith grains by the combined effects of solar ion irradiation and other processes that include deposition of impact or sputter-derived vapors. Although no longer considered the sole driver of space weathering, solar ion irradiation remains a key part of the space weathering puzzle, and quantitative data on its effects on regolith minerals are still in short supply. For the lunar regolith, previous transmission electron microscope (TEM) studies performed by ourselves and others have uncovered altered rims on ilmenite (FeTiO3) grains that point to this phase as a unique "witness plate" for unraveling nanoscale space weathering processes. Most notably, the radiation processed portions of these ilmenite rims consistently have a crystalline structure, in contrast to radiation damaged rims on regolith silicates that are characteristically amorphous. While this has tended to support informal designation of ilmenite as a "radiation resistant" regolith mineral, there are to date no experimental data that directly and quantitatively compare ilmenite s response to ion radiation relative to lunar silicates. Such data are needed because the radiation processed rims on ilmenite grains, although crystalline, are microstructurally and chemically complex, and exhibit changes linked to the formation of nanophase Fe metal, a key space weathering process. We report here the first ion radiation processing study of ilmenite performed by in-situ means using the Intermediate Voltage Electron Microscope- Tandem Irradiation facility (IVEM-Tandem) at Argonne National Laboratory. The capability of this facility for performing real time TEM observations of samples concurrent with ion irradiation makes it uniquely suited for studying the dose-dependence of amorphization and other changes in irradiated samples.

  20. Retinal detachment following cataract surgery with capsulorhexis.

    PubMed Central

    Kelley, J S; Doxanas, M T

    1995-01-01

    PURPOSE: To estimate the incidence of retinal detachment after cataract surgery with capsulorhexis. METHODS: A consecutive series of 2,150 cataract operations were followed for incidence of retinal detachment. A series of 1,000 patients from this group were analyzed for high risk factors: myopia, age, sex, operative complications and capsulotomy. RESULTS: With minimum one year follow up in 90% of patients the incidence of retinal detachment was 0.25% (5 cases). CONCLUSION: The true incidence of retinal detachment after cataract surgery remains elusive. There is probably a trend toward lower incidence compared to previous reports. PMID:8719688

  1. Roller coaster-associated retinal detachments.

    PubMed

    Shaikh, Saad

    2011-01-01

    The purpose of this study was to report two cases of rhegmatogenous retinal detachment noted immediately after roller coaster riding in an at-risk population. In separate incidents, a 35-year-old woman and a 45-year-old woman, both significantly myopic, presented with visual symptoms after riding roller coasters. Both patients were found to have acute rhegmatogenous retinal detachments associated with myopic degenerative changes. The pathology supported an acute, traumatic etiology for the detachments. Roller coaster riding should be considered an adjunct risk factor for retinal detachment in predisposed patients.

  2. Characterization of Ion Implanted and Laser Processed Wear Surfaces.

    DTIC Science & Technology

    1986-04-22

    Cavitation erosion tests were performed on nonimplanted and ion implanted samples of a Co’based hardface alloy (Stoody 3). Erosion of the test samples was...implanted samples of a Co-based hardface alloy (Stoody 3). Erosion of the test samples was found to initiate by debonding at the carbide-matrix interfaces

  3. Dual ion beam processed diamondlike films for industrial applications

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.; Kussmaul, M. T.; Banks, B. A.; Sovey, J. S.

    1991-01-01

    Single and dual beam ion source systems are used to generate amorphous diamondlike carbon (DLC) films, which were evaluated for a variety of applications including protective coatings on transmitting materials, power electronics as insulated gates and corrosion resistant barriers. A list of the desirable properties of DLC films along with potential applications are presented.

  4. Microfabricated surface-electrode ion traps for scalable quantum information processing

    NASA Astrophysics Data System (ADS)

    Seidelin, Signe; Britton, Joe; Chiaverini, John; Reichle, Rainer; Bollinger, John; Leibfried, Didi; Wesenberg, Janus; Blakestad, Brad; Epstein, Ryan; Amini, Jason; Brown, Kenton; Home, Jonathan; Hume, David; Shiga, Nobu; Itano, Wayne; Jost, John; Knill, Emmanuel; Langer, Chris; Ozeri, Roee; Wineland, David

    2007-03-01

    We confine individual atomic ions in an rf Paul trap with a novel geometry where the electrodes are located in a single plane and the ions confined above this plane [1,2,3]. This device is realized with simple fabrication procedures, making it a potential candidate for a scalable ion trap for quantum information processing using large numbers of ions. We confine laser-cooled ions 40 micrometers above planar electrodes. These electrodes are fabricated from gold on a fused quartz substrate. The heating rate of the ions is low enough to make the trap useful for quantum information processing. [1] J. Chiaverini et al., Quantum Inf. Comput. 5, 419 (2005). [2] S. Seidelin et al., Phys. Rev. Lett. 96, 253003 (2006). [3] J. Britton et al., quant-ph/0605170.

  5. Analysis of Voltage and Current Signal Processing in a Li-ion Battery Management System

    DTIC Science & Technology

    2010-09-01

    SUBJECT TERMS Pulsed Power, Charger , Buck Converter, Field Programmable Gate Array (FPGA), Lithium - ion Batteries 16. PRICE CODE 17. SECURITY...Congressional Research Service. July 31, 2000. [3] F. E. Filler, “A Pulsed Power System Design Using Lithium - ion Batteries and One Charger per Battery ...AND CURRENT SIGNAL PROCESSING IN A LI- ION BATTERY MANAGEMENT SYSTEM by Jerome Sean McConnon September 2010 Thesis Co-Advisors

  6. Detached Solidification of Germanium-Silicon Crystals on the ISS

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.; Croell, A.

    2016-01-01

    A series of Ge(sub 1-x) Si(sub x) crystal growth experiments are planned to be conducted in the Low Gradient Furnace (LGF) onboard the International Space Station. The primary objective of the research is to determine the influence of containment on the processing-induced defects and impurity incorporation in germanium-silicon alloy crystals. A comparison will be made between crystals grown by the normal and "detached" Bridgman methods and the ground-based float zone technique. Crystals grown without being in contact with a container have superior quality to otherwise similar crystals grown in direct contact with a container, especially with respect to impurity incorporation, formation of dislocations, and residual stress in crystals. "Detached" or "dewetted" Bridgman growth is similar to regular Bridgman growth in that most of the melt is in contact with the crucible wall, but the crystal is separated from the wall by a small gap, typically of the order of 10-100 microns. Long duration reduced gravity is essential to test the proposed theory of detached growth. Detached growth requires the establishment of a meniscus between the crystal and the ampoule wall. The existence of this meniscus depends on the ratio of the strength of gravity to capillary forces. On Earth, this ratio is large and stable detached growth can only be obtained over limited conditions. Crystals grown detached on the ground exhibited superior structural quality as evidenced by measurements of etch pit density, synchrotron white beam X-ray topography and double axis X-ray diffraction.

  7. Numerical Optimization of the Thermal Field in Bridgman Detached Growth

    NASA Technical Reports Server (NTRS)

    Stelian, C.; Volz, M. P.; Derby, J. J.

    2009-01-01

    The global modeling of the thermal field in two vertical Bridgman-like crystal growth configurations, has been performed to get optimal thermal conditions for a successful detached growth of Ge and CdTe crystals. These computations are performed using the CrysMAS code and expand upon our previous analysis [1] that propose a new mechanism involving the thermal field and meniscus position to explain stable conditions for dewetted Bridgman growth. The analysis of the vertical Bridgman configuration with two heaters, used by Palosz et al. for the detached growth of Ge, shows, consistent with their results, that the large wetting angle of germanium on boron nitride surfaces was an important factor to promote a successful detached growth. Our computations predict that by initiating growth much higher into the hot zone of the furnace, the thermal conditions will be favorable for continued detachment even for systems that did not exhibit high contact angles. The computations performed for a vertical gradient freeze configuration with three heaters representative of that used for the detached growth of CdTe, show favorable thermal conditions for dewetting during the entirely growth run described. Improved thermal conditions are also predicted for coated silica crucibles when the solid-liquid interface advances higher into the hot zone during the solidification process. The second set of experiments on CdTe growth described elsewhere has shown the reattachment of the crystal to the crucible after few centimeters of dewetted growth. The thermal modeling of this configuration shows a second solidification front appearing at the top of the sample and approaching the middle line across the third heater. In these conditions, the crystal grows detached from the bottom, but will be attached to the crucible in the upper part because of the solidification without gap in this region. The solidification with two interfaces can be avoided when the top of the sample is positioned below

  8. Surface ion trap structures with excellent optical access for quantum information processing

    NASA Astrophysics Data System (ADS)

    Maunz, P.; Blain, M.; Benito, F.; Chou, C.; Clark, C.; Descour, M.; Ellis, R.; Haltli, R.; Heller, E.; Kemme, S.; Sterk, J.; Tabakov, B.; Tigges, C.; Stick, D.

    2013-05-01

    Microfabricated surface electrode ion traps are necessary for the advancement of trapped ion quantum information processing as it offers a scalable way for realizing complex trap structures capable of storing and controlling many ions. The most promising way of performing two-qubit quantum gates in a chain of trapped ions is to focus laser beams on individual ions of the chain to drive gates. However, in surface ion traps the close proximity of the ions to the surface and the size of the chips usually cannot accommodate the tightly focused laser beams necessary to address individual ions parallel to the chip surface. Here we present a surface electrode ion trap monolithically fabricated in standard silicon technology that implements a linear quadrupole trap on a bowtie shaped chip with a narrow section that is only 1.2 mm wide. Laser beams parallel to the surface can be focused down to a waist of 4 μm with enough separation from the trap chip to prevent light scattering. The trap structure incorporates two Y-junctions for reordering ions and is optimized for quantum information processing. This work was supported by the Intelligence Advanced Research Projects Activity (IARPA). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  9. Detachment of a single water drop

    NASA Astrophysics Data System (ADS)

    Chashechkin, Yu. D.; Prokhorov, V. E.

    2014-01-01

    The detachment process of a single water drop from a nozzle made of poorly wetted material is followed using high-speed video equipment. The formation and motion dynamics of various flow components are investigated. These are the drop itself; a liquid bridge (jumper), which connects the drop with the mother liquid; the primary satellite, which is formed from the jumper; and a microsatellite, which is thrown from the satellite and flies to the mother liquid. The strong influence of surface effects, under which the satellite initially moves upward and only at a certain time starts to fall along the ballistic trajectory, is established. Bounce of the microsatellite from the mother liquid, which precedes its absorption, is fixed. It is shown that a stable connection of the formation mechanism of satellites with the jumper dynamics opens the possibility of obtaining uniform-sized drops.

  10. Nanomaterials-Enhanced Electrically Switched Ion Exchange Process for Water Treatment

    SciTech Connect

    Lin, Yuehe; Choi, Daiwon; Wang, Jun; Bontha, Jagannadha R.

    2009-01-01

    The objective of our work is to develop an electrically switched ion exchange (ESIX) system based on conducting polymer/carbon nanotube (CNT) nanocomposites as a new and cost-effective approach for removal of radioactive cesium, chromate, and perchlorate from contaminated groundwater. The ESIX technology combines ion exchange and electrochemistry to provide a selective, reversible method for the removal of target species from wastewater. In this technique, an electroactive ion exchange layer is deposited on a conducting substrate, and ion uptake and elution are controlled directly by modulation of the potential of the layer. ESIX offers the advantages of highly-efficient use of electrical energy combined with no secondary waste generation. Recently, we have improved upon the ESIX process by modifying the conducting substrate with carbon nanotubes prior to the deposition of the electroactive ion exchanger. The nanomaterial-based electroactive ion exchange technology will remove cesium-137, chromate, and perchlorate rapidly from wastewater. The high porosity and high surface area of the electroactive ion exchange nanocomposites results in high loading capacity and minimize interferences for non-target species. Since the ion adsorption/desorption is controlled electrically without generating a secondary waste, this electrically active ion exchange process is a green process technology that will greatly reduce operating costs.

  11. Ion Beam Deposition of Thin Films: Growth Processes and Nanostructure Formation

    SciTech Connect

    Hofsaess, Hans C.

    2004-12-01

    Ion beam deposition is a process far from thermodynamic equilibrium and is in particular suited to grow metastable thin films with diamond-like properties, such as tetrahedral amorphous carbon (ta-C) and cubic boron nitride (c-BN). In this contribution the atomistic description of the deposition and growth processes are reviewed and compared to experimental results, obtained from mass selected ion beam deposition. The focus will be set to the nucleation and growth processes of boron nitride as a model system for ion based thin film formation. Furthermore, recent examples for nanostructure formation in ion deposited compound thin films will be presented. Ion beam deposited metal-carbon nano-composite thin films exhibit a variety of different morphologies such as rather homogeneous nanocluster distributions embedded in an a-C matrix, but also the self-organized formation of nanoscale multilayer structures.

  12. Ion Implanted GaAs I.C. Process Technology

    DTIC Science & Technology

    1979-03-01

    The first multiplexer results show operation at "moderate" speed, 254 MHz clock rate with low power dissipation, 80 mW, for the entire circuit...34moderate" speed, 254 MHz clock rate with low power dissipation, 80 n14, for the entire circuit. Testing of wafers which are expected to demonstrate...etching, and plasma etching. Sputter etching and reactive ion etching were not considered since they operate at pressures of several mTor , and the

  13. Changes in membrane conductance play a pathogenic role in osmotic glial cell swelling in detached retinas.

    PubMed

    Wurm, Antje; Pannicke, Thomas; Iandiev, Ianors; Bühner, Eva; Pietsch, Uta-Carolin; Reichenbach, Andreas; Wiedemann, Peter; Uhlmann, Susann; Bringmann, Andreas

    2006-12-01

    Detachment of the neural retina from the pigment epithelium may be associated with tissue edema; however, the mechanisms of fluid accumulation are not understood. Because retinal detachment is usually not accompanied by vascular leakage, we investigated whether the osmotic swelling characteristics of retinal glial (Müller) cells are changed after experimental detachment of the porcine retina. Osmotic stress, induced by application of a hypotonic bath solution to retinal slices, caused swelling of Müller cell bodies in 7-day-detached retinas, but no swelling was inducible in slices of control retinas. Müller cell somata in slices of retinal areas that surround local detachment in situ also showed osmotic swelling, albeit at a smaller amplitude. The amplitude of osmotic Müller cell swelling correlated with the decrease in the K+ conductance, suggesting a causal relationship between both gliotic alterations. Further factors implicated in Müller cell swelling were inflammatory mediators and oxidative stress. We propose that a dysregulation of the ion and water transport through Müller cells may impair the fluid absorption from the retinal tissue, resulting in chronic fluid accumulation after detachment. This knowledge may lead to a better understanding of the mechanisms involved in retinal degeneration after detachment.

  14. Ion-plasma processes of the production of diffusion aluminide coatings

    NASA Astrophysics Data System (ADS)

    Muboyadzhyan, S. A.

    2010-03-01

    A novel ion-plasma process for ecologically safe formation of diffusion aluminide coatings on a substrate made of a superalloy, which has advantages as compared to the well-known thermodiffusion processes of their production, is described. The ion-plasma process is shown to provide the formation of diffusion aluminide coatings on the surface of a superalloy substrate according to various technologies. Owing to alloying with one or several elements from the series Y, Si, Cr, Hf, B, Co, etc., ion-plasma diffusion coatings have higher protective properties than analogous coatings produced by the traditional methods of powder, slip, and gas-circulating aluminizing.

  15. Removal and recovery of metal ions from process and waste streams using polymer filtration

    SciTech Connect

    Jarvinen, G.D.; Smith, B.F.; Robison, T.W.; Kraus, K.M.; Thompson, J.A.

    1999-06-13

    Polymer Filtration (PF) is an innovative, selective metal removal technology. Chelating, water-soluble polymers are used to selectively bind the desired metal ions and ultrafiltration is used to concentrate the polymer-metal complex producing a permeate with low levels of the targeted metal ion. When applied to the treatment of industrial metal-bearing aqueous process streams, the permeate water can often be reused within the process and the metal ions reclaimed. This technology is applicable to many types of industrial aqueous streams with widely varying chemistries. Application of PF to aqueous streams from nuclear materials processing and electroplating operations will be described.

  16. Cenozoic Evolution of the West Cycladic Detachment System

    NASA Astrophysics Data System (ADS)

    Iglseder, Christoph; Grasemann, Bernhard; Schneider, Dave A.; Senkowski, Carley A.; Stöckli, Dani

    2010-05-01

    Extension in the Aegean led to the formation of metamorphic core complexes and domes, with multistage extensional detachments cutting rocks of the Attic-Cycladic Crystalline at different structural and lithostratigraphic levels. Four kinematic provenances are here distinguished in the Cycladic extensional detachment system: (1) The North (Andros-Ikaria) and (2) Central (Naxos-Paros) Cycladic Detachment Systems, showing top N/NE sense of shear; (3) the South Cycladic Detachment System (Ios-Amorgos), part of the South Cycladic Shear Zone, with evidence for two opposite kinematic domains, an older top S/SE and a younger top N/NW sense of shear. In contrast, the newly documented (4) West Cycladic Detachment System (Sifnos-Lavrion) is dominated by a top SW/SSW sense of shear. Low-angled extensional detachments nucleated in the ductile regime and show progressive overprinting by ductile-brittle and then brittle deformation processes on Kea, Kythnos and Serifos. On Sifnos, an older top NE and brittle-ductile younger event, with top SW kinematics has been documented. In comparison, on the Greek mainland in Attica, top SW/SSW sense of shear allows the regional structure to be expanded. At both Lavrion in Attica and Serifos, the extensional detachments were intruded by syn-tectonic Late Miocene granodiorites. Cenozoic extension in the Western Cyclades is suggested to begin in the Eocene, with early S-type granite intrusion on Serifos at 43-37 Ma (U-Pb zircon). This is supported by Eocene/Early Oligocene Rb/Sr and Ar/Ar (cooling) ages of hanging-wall schists and marbles. Similar cooling ages, (post-) dating high-pressure/low-temperature metamorphism, have been described from Sifnos. During the Oligocene/Miocene, a decrease in greenschist-facies ages has been determined on the Serifos-Kythnos-Kea transect. Similar ages of greenschist-facies metamorphism have also been found on Sifnos. Initial stages of the Serifos granodiorite intrusion, coeval with initiation of the main

  17. Experimental results from detached plasmas in TFTR

    SciTech Connect

    Strachan, J.D.; Boody, F.P.; Bush, C.E.; Cohen, S.A.; Grek, B.; Grisham, L.; Jobes, F.C.; Johnson, D.W.; Mansfield, D.K.; Medley, S.S.

    1986-10-01

    Detached plasmas are formed in TFTR which have the principal property of the boundary to the high temperature plasma core being defined by a radiating layer. This paper documents the properties of TFTR ohmic-detached plasmas with a range of plasma densities at two different plasma currents.

  18. Characterization of Surface Features in Detached Grown GeSi Crystals

    NASA Technical Reports Server (NTRS)

    Cobb, S. D.; Volz, M. P.; Schweizer, M.; Kaiser, N.; Carpenter, P. K.; Szofran, F. R.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    The growth of detached crystals by the Bridgman technique, in which the growing crystal is not in contact with the crucible wall, has been observed both on earth and in microgravity conditions. At present, the mechanisms contributing to the detachment are not completely understood and until recently detachment has not been reproducibly obtained. It is commonly understood that the main factors that promote the occurrence of detached growth include: high contact angle between the melt and the crucible material, high growth angle, and a pressure difference between the annular gap around the solid below the melt and the volume above the melt along the meniscus. These parameters were varied in Bridgman growth experiments to determine the conditions required to achieve detached growth terrestrially in Ge and GeSi alloys. These experiments are in preparation for experiments on the International Space Station (ISS). The detailed objectives of the flight experiments and a description of the growth methods employed are the subject of another presentation at this Congress. Detached crystals were achieved repeatedly in pyrolytic boron nitride ampoules when a pressure difference was employed. All crystals, except for those grown in fused silica ampoules, were easily removed from their containers; however, this fact alone is not sufficient to infer detached growth. Detachment was verified by comparing profilometer measurements of the radius of the samples with observations of the sample surfaces using optical and electron microscopy. The surfaces of the attached areas of the crystals had the same shape and surface texture as the interior crucible wall. Regions of detached growth contained many unique features and crystal facets could usually be observed. Several of these surface features have been correlated with mechanisms of detachment or free surface growth in general and others to processing events or conditions. These results will be compared with observations of surface

  19. A microfabricated surface-electrode ion trap for scalable quantum information processing

    NASA Astrophysics Data System (ADS)

    Seidelin, Signe; Chiaverini, John; Reichle, Rainer; Bollinger, John; Leibfried, Didi; Britton, Joe; Wesenberg, Janus; Blakestad, Brad; Epstein, Ryan; Hume, David; Jost, John; Langer, Chris; Ozeri, Roee; Shiga, Nobu; Wineland, David

    2006-05-01

    We demonstrate confinement of individual atomic ions in a radio-frequency Paul trap with a novel geometry where the electrodes are located in a single plane and the ions confined above this plane. This device is realized with a relatively simple fabrication procedure and has important implications for quantum state manipulation and quantum information processing using large numbers of ions. We confine laser-cooled Mg-24 ions approximately 40 micrometer above planar gold electrodes. We measure the ions' motional frequencies and compare them to simulations. From measurements of the escape time of ions from the trap, we also determine a heating rate of approximately five motional quanta per millisecond for a trap frequency of 5.3 MHz.

  20. Surface effects during ion beam processing of materials

    SciTech Connect

    Averback, R.S.; Ghaly, M.; Zhu, H.; Caturla, M.J.; Marques, L.; Diaz de la Rubia, T.

    1996-12-31

    Microstructural changes of surfaces during ion implantation have been investigated on the atomic level by molecular dynamics computer simulations. Unlike past surface studies, which have been focused on the problem of sputtering, the current work examines the effects of collective materials response on surface topography. Collective behavior has been noted for the crystal interior in the context of thermal spikes, but the authors show here that it can lead to far more dramatic consequences at the surface. The investigation includes implantation in several metals, but emphasizing Pt, Si and Ge. In addition, the study includes the first simulations of implantations of a metallic glass, CuTi, and amorphous Si.

  1. Solar Ion Processing of Itokawa Grains: Reconciling Model Predictions with Sample Observations

    NASA Technical Reports Server (NTRS)

    Christoffersen, Roy; Keller, L. P.

    2014-01-01

    Analytical TEM observations of Itokawa grains reported to date show complex solar wind ion processing effects in the outer 30-100 nm of pyroxene and olivine grains. The effects include loss of long-range structural order, formation of isolated interval cavities or "bubbles", and other nanoscale compositional/microstructural variations. None of the effects so far described have, however, included complete ion-induced amorphization. To link the array of observed relationships to grain surface exposure times, we have adapted our previous numerical model for progressive solar ion processing effects in lunar regolith grains to the Itokawa samples. The model uses SRIM ion collision damage and implantation calculations within a framework of a constant-deposited-energy model for amorphization. Inputs include experimentally-measured amorphization fluences, a Pi steradian variable ion incidence geometry required for a rotating asteroid, and a numerical flux-versus-velocity solar wind spectrum.

  2. Ion-Ion Neutralization.

    DTIC Science & Technology

    1982-05-31

    Accession No. 3. Recipient’s Catalog Number FGL -TR-82 -0202 b- /- 4. Title (and Subtitle) 5. Type of Report & Period Covered ION-ION NEUTRALIZATION Final...few years under the terms of the grant has been the detailed study of binary ion-ion neutralization reactions involving ions of atmospheric...2TT, England. 1. INTRODUCTION Binary positive-ion negative-ion mutual neutralization viz: A+ + B->C + D (1) can be an important loss process for

  3. Heavy-ion induced genetic changes and evolution processes

    NASA Technical Reports Server (NTRS)

    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.

  4. Heavy-ion induced genetic changes and evolution processes

    NASA Technical Reports Server (NTRS)

    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. Optical Performance And Process Characterizations Of Several High Contrast Metal-Ion-Free Developer Processes

    NASA Astrophysics Data System (ADS)

    Petersen, John S.; Kozlowski, Alan E.

    1984-05-01

    Projection print quality is dependent upon the response of the resist/developer system to the optically projected image. For this reason, it is critical, during process optimization, to relate final pattern quality to both the chemical and physical contrast terms. One method for doing this is to monitor resist/developer response in the absence and then the presence of diffracted light. These results are then compared to the predicted optical requirements. For best performance, the resist/developer (or chemical) contrast must ex-ceed that of the potential optical (or physical) contrast. To do rapid contrast compari-sons it is convenient to relate the chemical contrast term,r, to the physical contrast term MTF, via the CMTF1: where the CMTF = (1014- 1)/(lol* 1) = (Ethreshold Einitial)/ (Ethreshold Einitial) and the MTF=(Emax Emin)/(Emax + EmiA. Perfect imaging potential occurs chemically when the CMTF = 0, Einitial r-- Ethreshold, and physically when the MTF = 1.0, Emin = 0. As a result, acceptable patterning occurs when the MTF/CMTF ratio is greater than one. This ratio is a comparative, accept/reject test only; final nrocess optimization is done by monitoring the accepted resist/developer systems' performance on projected images. Optimum process latitude is predicted by determining focal tolerances at various mask sizing biases and by measuring linewidth necking over steps. This study demonstrates the dependence of the final print quality on the chemical con-trast. A method is examined for approximating minimum allowable chemical contrast required for adequately printing desired device design sizes. Then chemical contrast results for various metal-ion-free develop processes are shown. Next, the combined resist/developer/ optical performance is optimized by using focal tolerance and linewidth control over steps as process constraints. Finally, it is shown that focal tolerances are dependent on chemical contrast and that the focus budget is tunable.

  6. Retinal detachment after open globe injury

    PubMed Central

    Stryjewski, Tomasz P.; Andreoli, Christopher M.; Eliott, Dean

    2013-01-01

    Purpose To characterize the development of retinal detachment after open globe trauma. Design Case-control study Participants 892 patients comprising 893 open globe injuries, of which 255 were ultimately diagnosed with retinal detachment, with the remaining eyes serving as controls. Methods Retrospective chart review of open globe injuries presenting to the Massachusetts Eye and Ear Infirmary between 1999 and 2011. Kaplan-Meier analysis was used to estimate time to detachment and multivariable logistic regression was used to define clinical factors associated with retinal detachment after open globe injury. Main Outcome Measures Demographic and clinical characteristics at the time of presentation after open globe injury, date of retinal detachment diagnosis, and last date of follow-up. Results Primary repair of the open globe was typically undertaken within hours of presentation. 255 eyes were ultimately diagnosed with retinal detachment after open globe trauma, yielding an incidence of 29% (95% confidence interval: 26%-32%). For eyes that developed retinal detachment, 27% (69/255) detached within 24 hours of primary open globe repair, 47% (119/255) detached within one week, 72% (183/255) within one month. Multivariable regression analysis revealed presence of vitreous hemorrhage (odds ratio: 7.29, p<0.001), higher zone of injury (odds ratio: 2.51 per integer increase in zone number, odds ratio: 1.00-6.30, p<0.001), and poorer Logarithm of the Minimum Angle of Resolution visual acuity at the time of presentation after open globe injury (odds ratio: 2.41 per integer increase in Logarithm of the Minimum Angle of Resolution visual acuity, odds ratio: 1.00-81.30, p<0.001) to be associated with retinal detachment. A screening tool, named herein the Retinal Detachment after Open Globe Injury (RD-OGI) score, was created. Conclusions Retinal detachment is common after open globe trauma, though often not appearing until days to weeks after the initial traumatic event

  7. Existence and Stability of Menisci in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2011-01-01

    Detached growth, also referred to as dewetted growth, is a Bridgman crystal growth process in which the melt is in contact with the crucible wall but the crystal is not. A meniscus bridges the gap between the top of the crystal and the crucible wall. The Young-Laplace capillary equation was used to calculate the crystal radii of detached states as a function of the pressure differential across the meniscus. The detached states depend on the contact angle of the melt with the crucible wall, the growth angle of the melt with respect to the solidifying crystal, and the Bond number. A static stability analysis was performed on the calculated detached states. The stability criterion was the sign of the second variation of the potential energy upon admissible meniscus shape perturbations. The conditions considered corresponded to the growth of Ge and InSb, in both terrestrial and microgravity conditions. Stability was found to depend significantly on whether the interior surface was considered to be microscopically rough or smooth, corresponding to pinned or unpinned states. It was also found that all meniscus shapes which are single-valued functions of the radius are statically stable in a microgravity environment.

  8. Liquid Droplet Detachment and Entrainment in Microscale Flows

    NASA Astrophysics Data System (ADS)

    Hidrovo, Carlos

    2005-11-01

    In this talk we will present a first order study of liquid water detachment and entrainment into air flows in hydrophobic microchannels. Silicon based microstructures consisting of 23 mm long U-shaped channels of different geometry were used for this purpose. The structures are treated with a Molecular Vapor Deposition (MVD) process that renders them hydrophobic. Liquid water is injected through a side slot located 2/3 of the way downstream from the air channel inlet. The water entering the air channel beads up into slugs or droplets that grow in size at this injection location until they fill and flood the channel or are carried away by the air flow. The slugs/droplets dimensions at detachment are correlated against superficial gas velocity and proper dimensionless parameters are postulated and examined to compare hydrodynamic forces against surface tension. It is found that slug/droplet detachment is dominated by two main forces: pressure gradient drag, arising from confinement of a viscous flow in the channel, and inertial drag, arising from the stagnation of the air due to obstruction by the slugs/droplets. A detachment regime map is postulated based on the relative importance of these forces under different flow conditions.

  9. Threshold processes of sodium ion emission from NaAu surface alloy

    NASA Astrophysics Data System (ADS)

    Knat'ko, M. V.; Lapushkin, M. N.

    2015-04-01

    We have studied threshold processes of Na+ ion emission from a semiconductor Na x Au y film formed on the surface of a gold substrate. In contrast to the classical notions of threshold processes involved in the surface ionization of alkali metal ions from heated metal surfaces, the diffusion exchange of atomic species between the surface and volume of the Na x Au y film ensures stable emission of Na+ ions from the substrate in the region of threshold temperatures. A diffusion mechanism of self-regulation of the surface coverage of alkali metal in the Na x Au y film is proposed.

  10. Process for the displacement of cyanide ions from metal-cyanide complexes

    DOEpatents

    Smith, Barbara F.; Robinson, Thomas W.

    1997-01-01

    The present invention relates to water-soluble polymers and the use of such water-soluble polymers in a process for the displacement of the cyanide ions from the metal ions within metal-cyanide complexes. The process waste streams can include metal-cyanide containing electroplating waste streams, mining leach waste streams, mineral processing waste streams, and related metal-cyanide containing waste streams. The metal ions of interest are metals that give very strong complexes with cyanide, mostly iron, nickel, and copper. The physical separation of the water-soluble polymer-metal complex from the cyanide ions can be accomplished through the use of ultrafiltration. Once the metal-cyanide complex is disrupted, the freed cyanide ions can be recovered for reuse or destroyed using available oxidative processes rendering the cyanide nonhazardous. The metal ions are released from the polymer, using dilute acid, metal ion oxidation state adjustment, or competing chelating agents, and collected and recovered or disposed of by appropriate waste management techniques. The water-soluble polymer can then be recycled. Preferred water-soluble polymers include polyethyleneimine and polyethyleneimine having a catechol or hydroxamate group.

  11. Current and Prospective Li-Ion Battery Recycling and Recovery Processes

    NASA Astrophysics Data System (ADS)

    Heelan, Joseph; Gratz, Eric; Zheng, Zhangfeng; Wang, Qiang; Chen, Mengyuan; Apelian, Diran; Wang, Yan

    2016-10-01

    The lithium ion (Li-ion) battery industry has been growing exponentially since its initial inception in the late 20th century. As battery materials evolve, the applications for Li-ion batteries have become even more diverse. To date, the main source of Li-ion battery use varies from consumer portable electronics to electric/hybrid electric vehicles. However, even with the continued rise of Li-ion battery development and commercialization, the recycling industry is lagging; approximately 95% of Li-ion batteries are landfilled instead of recycled upon reaching end of life. Industrialized recycling processes are limited and only capable of recovering secondary raw materials, not suitable for direct reuse in new batteries. Most technologies are also reliant on high concentrations of cobalt to be profitable, and intense battery sortation is necessary prior to processing. For this reason, it is critical that a new recycling process be commercialized that is capable of recovering more valuable materials at a higher efficiency. A new technology has been developed by the researchers at Worcester Polytechnic Institute which is capable of recovering LiNi x Mn y Co z O2 cathode material from a hydrometallurgical process, making the recycling system as a whole more economically viable. By implementing a flexible recycling system that is closed-loop, recycling of Li-ion batteries will become more prevalent saving millions of pounds of batteries from entering the waste stream each year.

  12. Dynamics of Faceted Nanoparticles Formation in a Crystalline Matrix During Ion Implantation Processing.

    PubMed

    Li, Kun-Dar

    2016-02-01

    The faceted nanoparticle synthesized by ion implantation, such as Zn, Cu or Ag nanoparticles, is one of the promising materials for the next generation of optical devices. To understand and better control the manufacturing processes of ion implantation, a theoretical model is applied to investigate the formation and evolution of faceted nanoparticles under various experimental conditions of implantation processing. In this study, the mechanisms of the anisotropic interfacial energy and kinetics with different ion distributions are taken into consideration to demonstrate the role of the crystallographic symmetry, ion energy and temperature on the faceted nanoparticles formation in a crystalline matrix. As presented in the numerical results, the morphological shape of the nanoparticles is mainly affected by the crystallographic symmetry, while the distribution of the precipitates is principally determined by the ion energy. For the condition of high-temperature implantation, a high mobility of ions causes the characteristic length of nanostructures to increase and creates a coarsening morphology of nanoparticles. It is attributed to a longer diffusion distance during the nucleation and growth processes. This model can be widely used for the predictions of the nanostructures formation with various ion implantation processes.

  13. Balancing incident heat and ion flow for process optimization in plasma based ion implantation

    NASA Astrophysics Data System (ADS)

    Mändl, S.; Manova, D.; Rauschenbach, B.

    2002-06-01

    Plasma based ion implantation at elevated temperatures is a technology often used to obtain thick surface layers of several µm by thermally activated diffusion, e.g. nitrogen in steel, titanium or aluminium. By lowering the pulse voltage at constant temperature, the current density can be increased at a constant heat flow. However, an upper limit is given by the ratio of the diffusion rate transporting the implanted ions from the surface towards the bulk and the sputter yield. This sputtering of the surface dominates for very high current densities and limits the maximum achievable layer thickness. Different maximum current densities were found for the four investigated systems - nitrogen in different steel grades, aluminium and titanium, as well as oxygen in titanium - reflecting the varying diffusivities. Additional requirements, besides the maximum current density, as a conformal treatment for complex objects containing small holes or trenches, as well as short heating times, can be solved most effectively by pulsed voltages in the range of 2-5 kV and an additional heating of the sample. The problem of a sample cooling time of several hours after the treatment is recognized. A partial solution would be to increase the gas pressure during the cooling phase for a more effective heat dissipation.

  14. Dynamics of mussel plaque detachment.

    PubMed

    Desmond, Kenneth W; Zacchia, Nicholas A; Waite, J Herbert; Valentine, Megan T

    2015-09-14

    Mussels are well known for their ability to generate and maintain strong, long-lasting adhesive bonds under hostile conditions. Many prior studies attribute their adhesive strength to the strong chemical interactions between the holdfast and substrate. While chemical interactions are certainly important, adhesive performance is also determined by contact geometry, and understanding the coupling between chemical interactions and the plaque shape and mechanical properties is essential in deploying bioinspired strategies when engineering improved adhesives. To investigate how the shape and mechanical properties of the mussel's plaque contribute to its adhesive performance, we use a custom built load frame capable of fully characterizing the dynamics of the detachment. With this, we can pull on samples along any orientation, while at the same time measuring the resulting force and imaging the bulk deformations of the plaque as well as the holdfast-substrate interface where debonding occurs. We find that the force-induced yielding of the mussel plaque improves the bond strength by two orders of magnitude and that the holdfast shape improves bond strength by an additional order of magnitude as compared to other simple geometries. These results demonstrate that optimizing the contact geometry can play as important a role on adhesive performance as optimizing the chemical interactions as observed in other organisms and model systems.

  15. Adsorption and ion exchange: basic principles and their application in food processing.

    PubMed

    Kammerer, Judith; Carle, Reinhold; Kammerer, Dietmar R

    2011-01-12

    A comprehensive overview of adsorption and ion exchange technology applied for food and nutraceutical production purposes is given in the present paper. Emanating from these fields of application, the main adsorbent and ion-exchange resin materials, their historical development, industrial production, and the main parameters characterizing these sorbents are covered. Furthermore, adsorption and ion exchange processes are detailed, also providing profound insights into kinetics, thermodynamics, and equilibrium model assumptions. In addition, the most important industrial adsorber and ion exchange processes making use of vessels and columns are summarized. Finally, an extensive overview of selected industrial applications of these technologies is provided, which is divided into general applications, food production applications, and the recovery of valuable bio- and technofunctional compounds from the byproducts of plant food processing, which may be used as natural food additives or for their potential health-beneficial effects in functional or enriched foods and nutraceuticals.

  16. Stability of Detached Grown Germanium Single Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Vujisic, L.; Szofran, F. R.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Detachment of the melt meniscus from the crucible during semiconductor Bridgman growth experiments has been observed in recent years, especially under microgravity experiments. Under earth conditions, the hydrostatic pressure counteracts the mechanism, whereby it is more difficult to achieve detached Bridgman growth. Attempts to get stable detached growth under terrestrial conditions have been discussed in the literature and have been the subject of recent experiments in our own group. The advantage of crystals grown without wall contact is obvious: In general, they possess a higher crystal quality than conventional Bridgman grown crystals with wall contact. However, due to the interaction of different parameters such as the wetting behavior of the melt with the crucible, and the dependence of the growth angle with the shape of the melt meniscus, the mechanism leading to detachment is very complicated and not completely understood. We have grown several doped and undoped Germanium crystals with the detached Bridgman and the normal Bridgman growth technique. Pyrolytic boron nitride containers were used for all growth experiments. In the detached grown crystals the typical gap thickness between the pBN crucible and the crystal is in the range of 10 to 100 micrometers, which was determined by performing profilometer measurements. Etch pit density measurements were also performed and a comparison between detached and attached grown crystals will be given. An interesting feature was detected on the surface of a detached grown crystal. Strong surface striations with an average axial distance of 0.5 mm were observed around the whole circumference. The maximum fluctuation of the gap thickness is in the range of 5-10 micrometers. These variations of the detached gap along the crystal axis can be explained by a kind of stiction of the melt/crucible interface and thus by a variation of the meniscus shape. This phenomenon leading to the fluctuation of the gap thickness will be

  17. Stability of Detached Grown Germanium Single Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Motakef, S.; Szofran, F. R.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Detachment of the melt meniscus from the crucible during semiconductor Bridgman growth experiments has been observed in recent years especially, under microgravity experiments. Under earth conditions, the hydrostatic pressure counteracts the mechanism, whereby it is more difficult to achieve detached Bridgman growth. Attempts to get stable detached growth under terrestrial conditions have been discussed in the literature and have been the subject of recent experiments in our own group. The advantage of crystals grown without wall contact is obvious: In general, they possess a higher crystal quality than conventional Bridgman grown crystals with wall contact. However, due to the interaction of different parameters such as the wetting behavior of the melt with the crucible, and the dependence of the growth angle with the shape of the melt meniscus, the mechanism leading to detachment is very complicated and not completely understood. We have grown several doped and undoped Germanium crystals with the detached Bridgman and the normal Bridgman growth technique. Pyrolytic boron nitride containers were used for all growth experiments. In the detached grown crystals the typical gap thickness between the pBN crucible and the crystal is in the range of 10 to 100 microns, which was determined by performing profilometer measurements. Etch pit density measurements were also performed and a comparison between detached and attached grown crystals will be given. An interesting feature was detected on the surface of a detached grown crystal. Strong surface striations with an average axial distance of 0.5mm were observed around the whole circumference. The maximum fluctuation of the gap thickness is in the range of 5-10 microns. These variations of the detached gap along the crystal axis can be explained by a kind of stiction of the melt/crucible interface and thus by a variation of the meniscus shape. This phenomenon leading to the fluctuation of the gap thickness will be

  18. Stability of Detached Grown Germanium Single Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Motakef, S.; Szofran, F. R.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Detachment of the melt meniscus from the crucible during semiconductor Bridgman growth experiments has been observed in recent years especially, under microgravity experiments. Under earth conditions, the hydrostatic pressure counteracts the mechanism, whereby it is more difficult to achieve detached Bridgman growth. Attempts to get stable detached growth under terrestrial conditions have been discussed in the literature and have been the subject of recent experiments in our own group. The advantage of crystals grown without wall contact is obvious: In general, they possess a higher crystal quality than conventional Bridgman grown crystals with wall contact. However, due to the interaction of different parameters such as the wetting behavior of the melt with the crucible, and the dependence of the growth angle with the shape of the melt meniscus, the mechanism leading to detachment is very complicated and not completely understood. We have grown several doped and undoped Germanium crystals with the detached Bridgman and the normal Bridgman growth technique. Pyrolytic boron nitride containers were used for all growth experiments. In the detached grown crystals the typical gap thickness between the pBN crucible and the crystal is in the range of 10 to 100 microns, which was determined by performing profilometer measurements. Etch pit density measurements were also performed and a comparison between detached and attached grown crystals will be given. An interesting feature was detected on the surface of a detached grown crystal. Strong surface striations with an average axial distance of 0.5mm were observed around the whole circumference. The maximum fluctuation of the gap thickness is in the range of 5-10 microns. These variations of the detached gap along the crystal axis can be explained by a kind of stiction of the melt/crucible interface and thus by a variation of the meniscus shape. This phenomenon leading to the fluctuation of the gap thickness will be

  19. Stability of Detached Grown Germanium Single Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Vujisic, L.; Szofran, F. R.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Detachment of the melt meniscus from the crucible during semiconductor Bridgman growth experiments has been observed in recent years, especially under microgravity experiments. Under earth conditions, the hydrostatic pressure counteracts the mechanism, whereby it is more difficult to achieve detached Bridgman growth. Attempts to get stable detached growth under terrestrial conditions have been discussed in the literature and have been the subject of recent experiments in our own group. The advantage of crystals grown without wall contact is obvious: In general, they possess a higher crystal quality than conventional Bridgman grown crystals with wall contact. However, due to the interaction of different parameters such as the wetting behavior of the melt with the crucible, and the dependence of the growth angle with the shape of the melt meniscus, the mechanism leading to detachment is very complicated and not completely understood. We have grown several doped and undoped Germanium crystals with the detached Bridgman and the normal Bridgman growth technique. Pyrolytic boron nitride containers were used for all growth experiments. In the detached grown crystals the typical gap thickness between the pBN crucible and the crystal is in the range of 10 to 100 micrometers, which was determined by performing profilometer measurements. Etch pit density measurements were also performed and a comparison between detached and attached grown crystals will be given. An interesting feature was detected on the surface of a detached grown crystal. Strong surface striations with an average axial distance of 0.5 mm were observed around the whole circumference. The maximum fluctuation of the gap thickness is in the range of 5-10 micrometers. These variations of the detached gap along the crystal axis can be explained by a kind of stiction of the melt/crucible interface and thus by a variation of the meniscus shape. This phenomenon leading to the fluctuation of the gap thickness will be

  20. Identification of Potential Biomarkers for Rhegmatogenous Retinal Detachment Associated with Choroidal Detachment by Vitreous iTRAQ-Based Proteomic Profiling

    PubMed Central

    Wu, Zhifeng; Ding, Nannan; Yu, Mengxi; Wang, Ke; Luo, Shasha; Zou, Wenjun; Zhou, Ying; Yan, Biao; Jiang, Qin

    2016-01-01

    Rhegmatogenous retinal detachment associated with choroidal detachment (RRDCD) is a complicated and serious type of rhegmatogenous retinal detachment (RRD). In this study, we identified differentially expressed proteins in the vitreous humors of RRDCD and RRD using isobaric tags for relative and absolute quantitation (iTRAQ) combined with nano-liquid chromatography-electrospray ion trap-mass spectrometry-mass spectrometry (nano-LC-ESI-MS/MS) and bioinformatic analysis. Our result shows that 103 differentially expressed proteins, including 54 up-regulated and 49 down-regulated proteins were identified in RRDCD. Gene ontology (GO) analysis suggested that most of the differentially expressed proteins were extracellular.The Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis suggested that proteins related to complement and coagulation cascades were significantly enriched. iTRAQ-based proteomic profiling reveals that complement and coagulation cascades and inflammation may play important roles in the pathogenesis of RRDCD. This study may provide novel insights into the pathogenesis of RRDCD and offer potential opportunities for the diagnosis and treatment of RRDCD. PMID:27941623

  1. [Development of all-silicone detachable balloons].

    PubMed

    Machida, T; Aoki, S; Sasaki, Y; Sasaki, Y; Iio, M; Matsuno, A; Yoshida, S; Basugi, N

    1990-11-25

    Treatment of cerebral vascular lesions such as carotid cavernous sinus fistulas and giant aneurysms is now being performed with intravascular detachable balloon embolization techniques. We have developed several types of all-silicone detachable balloons. Our balloons have self-sealing valves (with or without collars) and detach with simple traction. The self-sealing valve is smaller than 0.6 mm and the balloon can easily be placed through a 7-F catheter. We started clinical trials and a representative case was reported.

  2. [Retinal pigment epithelial detachment in hyperviscosity syndrome].

    PubMed

    Müller, V C; Mihailovic, N; Clemens, C R; Alten, F; Eter, N

    2017-05-15

    We present a case of a 57-year-old woman who reported bilateral visual impairment since 2 weeks. She had a medical history of congenital, cyanotic heart failure. Funduscopic examination revealed serous retinal detachment on the left side, central subneurosensory detachment on the right side, retinal vessel tortuosity and multiple retinal haemorrhages in the periphery. As blood analysis showed a distinct increase in haemoglobin and haematocrit, hyperviscosity syndrome was suspected to have caused bilateral serous retinal detachment. Isovolemic haemodilution was performed in close cooperation with the cardiology department with repeated phlebotomy, which resulted in a significant reduction of subretinal fluid and, concurrently, an increase in visual acuity.

  3. Mass spectroscopy of the ion flux produced during inductively coupled plasma nitriding process

    NASA Astrophysics Data System (ADS)

    Kolodko, D. V.; Kaziev, A. V.; Ageychenkov, D. G.; Meshcheryakova, E. A.; Pisarev, A. A.; Tumarkin, A. V.

    2017-05-01

    Ion fluxes on the surface of sample embedded in inductively coupled plasma have been studied in conditions typical for titanium alloy nitriding: total pressure 0.44 Pa, Ar/N2 = 70%/30%, and RF power 1500 W. The gas composition was independently monitored by the quadrupole analyser. The ion fluxes were sampled using a specially designed electrostatic extractor and then analysed with a magnetic sector mass-separator. The extractor design allowed us to apply a bias voltage to the plasma facing electrode thus imitating interaction of ions with the surface during the plasma processing. The ion fluxes of Ar+, {{{N}}}2{}+, and N+ on the surface were measured. The mass spectroscopy diagnostics unit is suitable for extensive ion content studies in the plasma technology facilities.

  4. A review of silicon microfabricated ion traps for quantum information processing

    NASA Astrophysics Data System (ADS)

    Cho, Dong-Il "Dan"; Hong, Seokjun; Lee, Minjae; Kim, Taehyun

    2015-12-01

    Quantum information processing (QIP) has become a hot research topic as evidenced by S. Haroche and D. J. Wineland receiving the Nobel Prize in Physics in 2012. Various MEMS-based microfabrication methods will be a key enabling technology in implementing novel and scalable ion traps for QIP. This paper provides a brief introduction of ion trap devices, and reviews ion traps made using conventional precision machining as well as MEMS-based microfabrication. Then, microfabrication methods for ion traps are explained in detail. Finally, current research issues in microfabricated ion traps are presented. The QIP renders significant new challenges for MEMS, as various QIP technologies are being developed for secure encrypted communication and complex computing applications.

  5. Fast and slow ion diffusion processes in lithium ion pouch cells during cycling observed with fiber optic strain sensors

    NASA Astrophysics Data System (ADS)

    Sommer, Lars Wilko; Kiesel, Peter; Ganguli, Anurag; Lochbaum, Alexander; Saha, Bhaskar; Schwartz, Julian; Bae, Chang-Jun; Alamgir, Mohamed; Raghavan, Ajay

    2015-11-01

    Cell monitoring for safe capacity utilization while maximizing pack life and performance is a key requirement for effective battery management and encouraging their adoption for clean-energy technologies. A key cell failure mode is the build-up of residual electrode strain over time, which affects both cell performance and life. Our team has been exploring the use of fiber optic (FO) sensors as a new alternative for cell state monitoring. In this present study, various charge-cycling experiments were performed on Lithium-ion pouch cells with a particular class of FO sensors, fiber Bragg gratings (FBGs), that were externally attached to the cells. An overshooting of the volume change at high SOC that recovers during rest can be observed. This phenomenon originates from the interplay between a fast and a slow Li ion diffusion process, which leads to non-homogeneous intercalation of Li ions. This paper focuses on the strain relaxation processes that occur after switching from charge to no-load phases. The correlation of the excess volume and subsequent relaxation to SOC as well as temperature is discussed. The implications of being able to monitor this phenomenon to control battery utilization for long life are also discussed.

  6. Characterization of Surface Features in Detached Grown GeSi Crystals

    NASA Technical Reports Server (NTRS)

    Cobb, S. D.; Volz, M. P.; Schweizer, M.; Kaiser, N.; Carpenter, P. K.; Szofran, F. R.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    The growth of detached crystals by the Bridgman technique, in which the growing crystal is not in contact with the crucible wall, has been observed both on earth and in microgravity conditions. At present, the mechanisms contributing to the detachment are not completely understood and until recently detachment has not been reproducibly obtained. It is commonly understood that the main factors that promote the occurrence of detached growth include: high contact angle between the melt and the crucible material, high growth angle, and a pressure difference between the annular gap around the solid below the melt and the volume above the melt along the meniscus. These parameters were varied in Bridgman growth experiments to determine the conditions required to achieve detached growth terrestrially in Ge and GeSi alloys. These experiments are in preparation for experiments on the International Space Station (ISS). The detailed objectives of the flight experiments and a description of the growth methods employed are the subject of another presentation at this Conference. Detached crystals were achieved repeatedly in pyrolytic boron nitride ampoules when a pressure difference was employed. All crystals, except for those grown in fused silica ampoules, were easily removed from their containers, however, this fact alone is not sufficient to infer detached growth. Detachment was verified by comparing profilometer measurements of the radius of the samples with observations of the sample surfaces using optical and electron microscopy. The surfaces of the attached areas of the crystals had the same shape and surface texture as the interior crucible wall. Regions of detached growth contained many unique features and crystal facets could usually be observed. Several of these surface features have been correlated with mechanisms of detachment or free-surface growth and others to processing events or conditions.

  7. Hard surfaced polymeric materials by ion beam processing

    SciTech Connect

    Simandl, R.F.; Rose, D.

    1996-09-27

    Initially, both General Motors and Lockheed Martin Energy Systems, Inc. were interested in altering the surface properties of polymers using ion beam technologies. Specifically, GM wished to treat the nylon that is used to encapsulate automotive assemblies so that it would be impervious to the alcohols and ethers used in present day blends of gasoline. Fuel oxygenates such as methanol can rapidly permeate the nylon encapsulant and tend to corrode the components within the assemblies. Once the CRADA was initiated, GM learned about the cleaning/decontamination expertise that was available at the Oak Ridge Y-12 Plant. Because GM was also interested in solving contamination issues related to these assemblies, GM worked with Lockheed Martin Energy Systems, Inc. to amend the CRADA to include such issues. Y-12 was eager to share its environmentally friendly, cleaning/decontamination expertise and also to expand upon its knowledge in this area. GM provided funds into the CRADA in order to address these contamination issues. Further on into the CRADA, GM put even more emphasis on the decontamination issues. This change in direction resulted because of rapid progress on the decontamination issues and, secondly, because GM changed its component material from nylon to the highly impervious polyphenylene sulfide.

  8. Negative ion effects on hemispheric processing and selective attention in the mentally retarded.

    PubMed

    Morton, L L; Kershner, J R

    1987-06-01

    The effect of high concentrations of negative air ions on a dichotic digits task was investigated in 19 mentally retarded individuals. Subjects were assigned randomly to an ion or to an unmodified-air placebo condition under double-blind testing. Left and right ears were precued for report order and this order was reversed for the second set of trials. Negative ions promoted greater left hemisphere lateralization on the first set of trials, and enhanced recall when switching to the opposite channels, in the second set of trials. However, the ion-induced REA occurred at the expense of selective attention to the left channel and superior left ear recall after the right ear first condition is an anomalous dichotic listening pattern. Such paradoxical results suggest that negative ions are not necessarily beneficial or detrimental to processing. Negative ions may increase arousal, in this case amplifying a time-phased, information processing disorder in the retarded characterized by excessive right hemisphere inhibition during early processing of receptive speech and diffuse interhemispheric excitatory activation during later processing.

  9. The development of data acquisition and processing application system for RF ion source

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaodan; Wang, Xiaoying; Hu, Chundong; Jiang, Caichao; Xie, Yahong; Zhao, Yuanzhe

    2017-07-01

    As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency (RF) ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and high reliability. In addition, it easily achieves long-pulse steady-state operation. During the process of the development and testing of the RF ion source, a lot of original experimental data will be generated. Therefore, it is necessary to develop a stable and reliable computer data acquisition and processing application system for realizing the functions of data acquisition, storage, access, and real-time monitoring. In this paper, the development of a data acquisition and processing application system for the RF ion source is presented. The hardware platform is based on the PXI system and the software is programmed on the LabVIEW development environment. The key technologies that are used for the implementation of this software programming mainly include the long-pulse data acquisition technology, multi-threading processing technology, transmission control communication protocol, and the Lempel-Ziv-Oberhumer data compression algorithm. Now, this design has been tested and applied on the RF ion source. The test results show that it can work reliably and steadily. With the help of this design, the stable plasma discharge data of the RF ion source are collected, stored, accessed, and monitored in real-time. It is shown that it has a very practical application significance for the RF experiments.

  10. Shape Evolution of Detached Bridgman Crystals Grown in Microgravity

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2015-01-01

    Detached (or dewetted) Bridgman crystal growth defines that process in which a gap exists between a growing crystal and the crucible wall. In microgravity, the parameters that influence the existence of a stable gap are the growth angle of the solidifying crystal, the contact angle between the melt and the crucible wall, and the pressure difference across the meniscus. During actual crystal growth, the initial crystal radius will not have the precise value required for stable detached growth. Beginning with a crystal diameter that differs from stable conditions, numerical calculations are used to analyze the transient crystal growth process. Depending on the initial conditions and growth parameters, the crystal shape will either evolve towards attachment at the crucible wall, towards a stable gap width, or inwards towards eventual collapse of the meniscus. Dynamic growth stability is observed only when the sum of the growth and contact angles exceeds 180 degrees.

  11. [Ocular hypertension after surgery for retinal detachment].

    PubMed

    Muşat, O; Cristescu, R; Coman, Corina; Asandi, R

    2012-01-01

    This papers presents a case of a patient with retinal detachement, 3 days ago operated (posterior vitrectomy internal tamponament with silicon oil 1000) who develop increased ocular pressure following silicon oil output in the anterior chamber.

  12. [Intraocular hypertension after retinal detachment surgery].

    PubMed

    Muşat, O; Cristescu, R; Coman, Corina; Asandi, R

    2012-01-01

    This papers presents a case of a patient with retinal detachment, 3 days ago operated (posterior vitrectomy, internal tamponament with silicon oil 1000) who developed increased ocular pressure following silicon oil output in the anterior chamber.

  13. Quantifying micron-scale grain detachment during weathering experiments on limestone

    NASA Astrophysics Data System (ADS)

    Levenson, Yael; Emmanuel, Simon

    2016-01-01

    Weathering in carbonate rocks is often assumed to be governed by chemical dissolution. Nevertheless, chemical processes can be coupled to mechanical mechanisms, with small grains undergoing partial dissolution along grain boundaries, followed by detachment from the rock surface. Crucially, this process can even extend down to the micron-scale. Although chemo-mechanical detachment could be critical for the understanding of carbonate weathering at the global scale, the role it plays has not been directly quantified. To calculate the contribution of grain detachment to surface retreat rates, and to determine the impact of the flow regime, we carried out a series of flow-through weathering experiments on micritic limestone. Using atomic force microscopy, we obtained high resolution in situ data of surface topography for reacting rock surfaces. In all the experiments, both grain detachment and chemical dissolution were observed. Under the laminar flow conditions we explored, we found no clear correlation between flow rate and the size of detached grains, or between the flow rate and the frequency of grain detachment events. Importantly, our results establish that grain detachment contributes significantly to the overall surface retreat, on average accelerating mass loss by 38%. In addition to speeding up weathering, this micron-scale mechanism could also influence the evolution of porosity in aquifers and hydrocarbon reservoirs, and provide a natural flux of colloids that could transport heavy metals or radionuclides in groundwater.

  14. Electrowetting-on-dielectric assisted bubble detachment in a liquid film

    NASA Astrophysics Data System (ADS)

    Wang, S.; Chen, H. H.; Chen, C. L.

    2016-05-01

    Drawing inspiration from electrowetting-controlled droplets, the potential advantages of electrowetting for bubble dynamics are investigated experimentally. In this study, we present and characterize an open electrowetting-on-dielectric (EWOD) system for studying the bubble behavior. Both detachment and non-detachment processes of a small single bubble in a thick liquid film under EWOD were experimentally observed. The measurement of contact angle changes of the small air bubble shows relatively good agreement with Young-Lippmann's equation within the majority of the test voltage range, except for the saturation region. Meanwhile, we have experimentally demonstrated both the characteristics of single- and double-bubble detachment within a thin liquid film. Direct bubble detachment may occur when it touches the gas-liquid interface during the process of contact angle change, while indirect bubble detachment is highly possible due to the dramatic oscillation resulting from the detachment of adjacent bubbles. The experimental results demonstrate that EWOD can effectively facilitate the detachment of small air bubble in a thin liquid film.

  15. Microfabricated surface-electrode ion traps for scalable quantum information processing

    NASA Astrophysics Data System (ADS)

    Seidelin, S.; Britton, J.; Chiaverini, J.; Reichle, R.; Bollinger, J. J.; Leibfried, D.; Wesenberg, J. H.; Blakestad, R. B.; Epstein, R. J.; Amini, J. M.; Brown, K. R.; Home, J. P.; Hume, D. B.; Itano, W. M.; Jost, J. D.; Knill, E.; Langer, C.; Ozeri, R.; Shiga, N.; Wineland, D. J.

    2007-06-01

    We confine individual atomic ions in rf Paul traps with a novel geometry where the electrodes are located in a single plane and the ions are confined above this plane ootnotetextJ. Chiaverini et al., Quantum Inf. Comput. 5, 419 (2005).^, ootnotetextS. Seidelin et al., Phys. Rev. Lett. 96, 253003 (2006).^, ootnotetextJ. Britton et al., quant-ph/0605170.. These devices are realized with simple fabrication procedures, making them potentially scalable for quantum information processing using large numbers of ions. For traps fabricated from gold on fused quartz, the ions are 40 micrometers above the planar electrodes and their heating rate is low enough to make the traps useful for quantum information processing.

  16. Detachment of secondary dendrite arm in a directionally solidified Sn-Ni peritectic alloy under deceleration growth condition

    NASA Astrophysics Data System (ADS)

    Peng, Peng; Li, Xinzhong; Li, Jiangong; Su, Yanqing; Guo, Jingjie; Fu, Hengzhi

    2016-06-01

    In order to better understand the detachment mechanism of secondary dendrite arm during peritectic solidification, the detachment of secondary dendrite arm from the primary dendrite arms in directionally solidified Sn-36at.%Ni peritectic alloys is investigated at different deceleration rates. Extensive detachment of secondary dendrite arms from primary stem is observed below peritectic reaction temperature TP. And an analytical model is established to characterize the detachment process in terms of the secondary dendrite arm spacing λ2, the root radius of detached arms and the specific surface area (SV) of dendrites. It is found that the detachment mechanism is caused by not only curvature difference between the tips and roots of secondary branches, but also that between the thicker secondary branches and the thinner ones. Besides, this detachment process is significantly accelerated by the temperature gradient zone melting (TGZM) effect during peritectic solidification. It is demonstrated that the reaction constant (f) which is used to characterize the kinetics of peritectic reaction is crucial for the determination of the detachment process. The value of f not only changes with growth rate but also with solidification time at a given deceleration rate. In conclusion, these findings help the better understanding of the detachment mechanism.

  17. Detachment of secondary dendrite arm in a directionally solidified Sn-Ni peritectic alloy under deceleration growth condition

    PubMed Central

    Peng, Peng; Li, Xinzhong; Li, Jiangong; Su, Yanqing; Guo, Jingjie; Fu, Hengzhi

    2016-01-01

    In order to better understand the detachment mechanism of secondary dendrite arm during peritectic solidification, the detachment of secondary dendrite arm from the primary dendrite arms in directionally solidified Sn-36at.%Ni peritectic alloys is investigated at different deceleration rates. Extensive detachment of secondary dendrite arms from primary stem is observed below peritectic reaction temperature TP. And an analytical model is established to characterize the detachment process in terms of the secondary dendrite arm spacing λ2, the root radius of detached arms and the specific surface area (SV) of dendrites. It is found that the detachment mechanism is caused by not only curvature difference between the tips and roots of secondary branches, but also that between the thicker secondary branches and the thinner ones. Besides, this detachment process is significantly accelerated by the temperature gradient zone melting (TGZM) effect during peritectic solidification. It is demonstrated that the reaction constant (f) which is used to characterize the kinetics of peritectic reaction is crucial for the determination of the detachment process. The value of f not only changes with growth rate but also with solidification time at a given deceleration rate. In conclusion, these findings help the better understanding of the detachment mechanism. PMID:27270334

  18. Features of the processes of ion heating in polar boundary of the night auroral oval

    NASA Astrophysics Data System (ADS)

    Chugunin, Dmitriy; Lutsenko, Volt; Romantsova, Tatiana; Mogilevsky, Mikhail; Moiseenko, Irina

    Investigation of the processes of ion heating in polar boundary of the night auroral oval measured by INTERBALL-2 (Auroral probe) is presented. Measurements of particles and waves were made on altitude about 20000 км. Feature of the orbits was the satellite slid along auroral oval and stay long time in the auroral zone. It were cases chosen when the polar boundary moved and passed through satellite. Particular attention is given to ions heating at this border and to ion heating position in relation to polar boundary of particle precipitation.

  19. Fabrication 3D buried channel optical waveguide modulators on field-driven ion exchange process

    NASA Astrophysics Data System (ADS)

    Zhou, Zigang; Chen, Wenqiang; Zhu, Li; Li, Jing; Luo, Xiaoying

    2010-10-01

    A high electric field technique was developed to fabricate buried optical waveguide modulator on K9 optical glass. The 80V voltage was applied on the glass to accelerate the field-driven ion exchange process by expeditiously replacing host sodium ions in the glass with silver ions. As a result, the optical loss for optical waveguide modulator was measured using the edge coupling technique with a 0.6328μm He-Ne laser. Loss of 0.20 dB/cm was obtained for channel waveguides of 25μm in depth, relatively low for waveguides of such depth at red wavelength.

  20. Hexuronic Acid Stereochemistry Determination in Chondroitin Sulfate Glycosaminoglycan Oligosaccharides by Electron Detachment Dissociation

    PubMed Central

    Leach, Franklin E.; Ly, Mellisa; Laremore, Tatiana N.; Wolff, Jeremy J.; Perlow, Jacob; Linhardt, Robert J.; Amster, I. Jonathan

    2013-01-01

    Electron detachment dissociation (EDD) has previously provided stereo-specific product ions that allow for the assignment of the acidic C-5stereochemistry in heparan sulfate glycosaminoglycans (GAGs), but application of the same methodology to an epimer pair in the chondroitin sulfate glycoform class does not provide the same result. A series of experiments have been conducted in which glycosaminoglycan precursor ions are independently activated by electron detachment dissociation (EDD), electron induced dissociation (EID), and negative electron transfer dissociation (NETD) to assign the stereochemistry in chondroitin sulfate (CS) epimers and investigate the mechanisms for product ion formation during EDD in CS glycoforms. This approach allows for the assignment of electronic excitation products formed by EID and detachment products to radical pathways in NETD, both of which occur simultaneously during EDD. The uronic acid stereochemistry in electron detachment spectra produces intensity differences when assigned glycosidic and cross-ring cleavages are compared. The variations in the intensities of the doubly deprotonated 0,2X3 and Y3 ions have been shown to be indicative of CS-A/DS composition during the CID of binary mixtures. These ions can provide insight into the uronic acid composition of binary mixtures in EDD, but the relative abundances, although reproducible, are low compared with those in a CID spectrum acquired on an ion trap. The application of principal component analysis (PCA) presents a multivariate approach to determining the uronic acid stereochemistry spectra of these GAGs by taking advantage of the reproducible peak distributions produced by electron detachment. PMID:22825742

  1. Mechanics of Shale Detachments - insights from the Khao-Kwang fold-and-thrust belt, Thailand

    NASA Astrophysics Data System (ADS)

    von Hagke, C.; Morley, C. K.; Kanitpanyacharoen, W.

    2016-12-01

    Shale detachments are the key slip horizons in fold and thrust belts, accretionary prisms, gravity driven systems ranging from major deltas to mass transport complexes and hybrid gravity-lithospheric-stress driven systems. Despite our qualitative understanding of factors contributing to detachment weakness such as mineralogy, pore fluid pressure, or efficiency of structure localization, it is difficult to assess the contribution of the individual factors. Here we present multi-scale analysis of a clay detachment within carbonate rocks, where it is possible to study structures formed within a similar temperature and pressure regime, and thus only varying due to lithological contrasts. We mapped the detachment at outcrop scale, where it shows considerable variations in structural style, as well as localization within different clay and limestone horizons. Zones of low and high strain have been identified. We investigate these changes in macroscopic deformation style using Virtual Polarizing Microscopy, and the combined methods of Broad Ion Beam milling and Scanning Electron Microscopy. We characterize the detachment at all scales, from outcrop down to nano-meters. Results show strain localization in the detachment is heterogeneous, and shows strong variations along strike. Within the clay package, strain localizes along zones rich in organic matter. Highest strain does not only occur in the clay units, but partly is accommodated in the surrounding limestone. We speculate clays only form the weakest layer when sufficient organic matter is present.

  2. Ion-Exchanged Waveguides for Signal Processing Applications - A Novel Electrolytic Process.

    DTIC Science & Technology

    1987-03-07

    1986 . 3] R. K. Lagu and V. Ramaswamy, "Fabrication of Single Mode Glass Waveguide by Electrolytic Release of Silver Ions," Appl. Phys. Lett., 45, pp...Quantum Electron., QE-22, pp. 883-891, 1986 . 7 [111] P. Chludzinski, R. V. Ramaswamy, and T. J. Anderson, "Ion-Fxchange Between Sode-Lime Silicate Glass and...Parameter Relationships for the Design of Planar, Silver Ion-Exchanged Glass Waveguide," IEEE J. Lightwave Tech., LT-4, pp. 176-131, 1986 . [20] R. K. Lagu

  3. Detached plasma in Saturn's front side magnetosphere

    NASA Technical Reports Server (NTRS)

    Goertz, C. K.

    1983-01-01

    Plasma observations in the outer front side Saturnian magnetosphere are discussed which indicate the existence of dense flux tubes outside the plasma sheets. It is suggested that flux tubes are detached from the plasma sheet by a centifugally driven flute instability. The same instability leads to a dispersal of Titan-injected plasma. It is shown that the detached flux tubes will probably break open as they convect into the nightside magnetotail and lose their content in the form of a planetary wind.

  4. Demonstration of a Scalable, Multiplexed Ion Trap for Quantum Information Processing

    DTIC Science & Technology

    2009-07-09

    ion shuttling, storage, and manipulation, Appl. Phys. Letters 88, pp. 034101. 6. M. Riebe, et al. (2004), Deterministic quantum teleportation with atoms...Nature 429, pp. 734. 7. M. D. Barrett, et al. (2004), Deterministic quantum teleportation of atomic qubits, Nature 429, pp. 737. 8. J. Chiaverini...REPORT DEMONSTRATION OF A SCALABLE, MULTIPLEXED ION TRAPFOR QUANTUM INFORMATION PROCESSING 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: A scalable

  5. Charge exchange processes of high energy heavy ions channeled in crystals

    NASA Astrophysics Data System (ADS)

    Andriamonje, S.; Chevallier, M.; Cohen, C.; Dural, J.; Genre, R.; Girard, Y.; Groeneveld, K. O.; Kemmler, J.; Kirsch, R.; L'Hoir, A.; Maier, R.; Poizat, J. C.; Quéré, Y.; Remillieux, J.; Schmaus, D.; Toulemonde, M.

    The interaction of moving ions with single crystals is very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. The experiments show that high energy heavy ion channeling deeply modifies the slowing down and charge exchange processes. In this review, we describe the opportunity offered by channeling conditions to study the charge exchange processes. Some aspects of the charge exchange processes with high energy channeled heavy ions are selected from the extensive literature published over the past few years on this subject. Special attention is given to the work performed at the GANIL facility on the study of Radiative Electron Capture (REC), Electron Impact Ionisation (EII), and convoy electron emission. Finally we emphasize the interest of studying resonant charge exchange processes such as Resonant Coherent Excitation (RCE), Resonant Transfer and Excitation (RTE) or Dielectronic Recombination (DR) and the recently proposed Nuclear Excitation by Electron Capture (NEEC).

  6. Characterization of stainless steel surface processed using electrolytic oxidation and titanium complex ion solution

    NASA Astrophysics Data System (ADS)

    Kang, Yubin; Choi, Jaeyoung; Park, Jinju; Kim, Woo-Byoung; Lee, Kun-Jae

    2017-09-01

    This study attempts to improve the physical and chemical adhesion between metals and ceramics by using electrolytic oxidation and a titanium organic/inorganic complex ion solution on the SS-304 plate. Surface analysis confirmed the existence of the Tisbnd Osbnd Mx bonds formed by the bonding between the metal ions and the Ti oxide at the surface of the pre-processed SS plate, and improved chemical adhesion during ceramic coating was expected by confirming the presence of the carboxylic group. The adhesion was evaluated by using the ceramic coating solution in order to assess the improved adhesion of the SS plate under conditions. The results showed that both the adhesion and durability were largely improved in the sample processed with all the pre-processing steps, thus confirming that the physical and chemical adhesion between metals and ceramics can be improved by enhancing the physical roughness via electrolytic oxidation and pre-processing using a Ti complex ion solution.

  7. A model of ion transport processes along and across the neuronal membrane.

    PubMed

    Xiang, Z X; Liu, G Z; Tang, C X; Yan, L X

    2017-01-01

    In this study, we provide a foundational model of ion transport processes in the intracellular and extracellular compartments of neurons at the nanoscale. There are two different kinds of ionic transport processes: (i) ionic transport across the neuronal membrane (trans-membrane), and (ii) ionic transport along both the intracellular and extracellular surfaces of the membrane. Brownian dynamics simulations are used to give a description of ionic trans-membrane transport. Electro-diffusion is used to model ion transport along the membrane surface, and the two transport processes can be linked analytically. In our model, we found that the interactions between ions and ion channels result in high-frequency ionic oscillations during trans-membrane transport. In ion transport along the membrane, high-frequency ionic oscillations may be evoked on both the intracellular and extracellular surfaces of the plasma membrane. The electric field caused by Coulomb interactions between the ions is found to be the most likely origin of those ionic oscillations.

  8. Cancer cell survival during detachment from the ECM: multiple barriers to tumour progression.

    PubMed

    Buchheit, Cassandra L; Weigel, Kelsey J; Schafer, Zachary T

    2014-09-01

    Epithelial cells require attachment to the extracellular matrix (ECM) for survival. However, during tumour progression and metastasis, cancerous epithelial cells must adapt to and survive in the absence of ECM. During the past 20 years, several cellular changes, including anoikis, have been shown to regulate cell viability when cells become detached from the ECM. In this Opinion article, we review in detail how cancer cells can overcome or take advantage of these specific processes. Gaining a better understanding of how cancer cells survive during detachment from the ECM will be instrumental in designing chemotherapeutic strategies that aim to eliminate ECM-detached metastatic cells.

  9. Ion exchange membrane bioreactor for selective removal of nitrate from drinking water: control of ion fluxes and process performance.

    PubMed

    Velizarov, Svetlozar; Crespo, João G; Reis, Maria A

    2002-01-01

    An ion exchange membrane bioreactor (IEMB), consisting of a monoanion permselective membrane dialyzer coupled to a stirred anoxic vessel with an enriched mixed denitrifying culture, has been studied for nitrate removal from drinking water. The influence of nitrate and chloride concentrations on the selectivity of nitrate transport in the IEMB process was investigated. With appropriate dosing of chloride ions to the IEMB biocompartment, it was possible to regulate the net bicarbonate flux in the system, thus maintaining the bicarbonate concentration in the treated water at the desired level. The latter was not possible to achieve in Donnan dialysis, operated as a single process in which, besides the lower nitrate removal efficiency found, bicarbonate was co-extracted together with nitrate from the polluted water stream. Residual carbon source (ethanol) and nitrite were not detected in the treated water produced in the IEMB system. With a concentration of nitrate in the polluted water three times higher than the maximum contaminant level of 50 mg L(-1) allowed, the IEMB process was successfully operated for a period of 1 month before exceeding this limit.

  10. Characterization Modeling of the Flow Through Ion Gun: Applications to Nitride Processing

    SciTech Connect

    Dennis, Darcie

    2003-07-01

    The objective of this work was to characterize the flow through ion gun and verify the results with optimal production of cubic boron nitride thin film coatings. The experimental method involved characterizing the plasma produced by the ion source, calculating the operational capabilities of the ion source, correlating the ion source processing conditions to known deposition conditions for BN films, depositing BN films and characterizing the materials produced. In this manner, an understanding of the source operation and capabilities can be discerned as well as an observation of the unique features of this ion source. The plasma characterization was conducted with the use of a Hiden® Analytical electrostatic quadrupole plasma (EQP) analyzer. The resulting energy spectrum of the selected masses provided information about the population of ionic species present in the plasma during deposition under controlled conditions. Total ion flux was measured using a Faraday cup to correlate the two parameters. Measurements of the total ion flux combined with the information from the EQP were used to calculate the total ion flux of the individual species incident on the substrate during deposition. An oscillating quartz crystal monitor measured the deposition rate which was correlated to the atomic arrival rate at the substrate. Using the combination of this information, a momentum transfer parameter was calculated for optimal processing conditions of BN films using the FTIG. Characterization of the resulting films was challenging due to a number of difficulties with most common analytical techniques. However, XTEM revealed that the FTIG actually oscillates in and out of the necessary conditions for cBN deposition. The films also show non-uniformities, indicating the plasma was not continuously stable during the deposition. The cBN films formed consisted of 10-20 nm grain sizes. Electron diffraction was used to identify cBN crystallites and verify the processing parameters.

  11. Ion-induced Processing of Cosmic Silicates: A Possible Formation Pathway to GEMS

    NASA Astrophysics Data System (ADS)

    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.

  12. First Results From A Multi-Ion Beam Lithography And Processing System At The University Of Florida

    SciTech Connect

    Gila, Brent; Appleton, Bill R.; Fridmann, Joel; Sanabia, Jason E.; Mazarov, Paul; Bauerdick, S.; Bruchhaus, Lars; Mimura, Ryo; Jede, Ralf

    2011-06-01

    The University of Florida (UF) have collaborated with Raith to develop a version of the Raith ionLiNE IBL system that has the capability to deliver multi-ion species in addition to the Ga ions normally available. The UF system is currently equipped with a AuSi liquid metal alloy ion source (LMAIS) and ExB filter making it capable of delivering Au and Si ions and ion clusters for ion beam processing. Other LMAIS systems could be developed in the future to deliver other ion species. This system is capable of high performance ion beam lithography, sputter profiling, maskless ion implantation, ion beam mixing, and spatial and temporal ion beam assisted writing and processing over large areas (100 mm2)--all with selected ion species at voltages from 15-40 kV and nanometer precision. We discuss the performance of the system with the AuSi LMAIS source and ExB mass separator. We report on initial results from the basic system characterization, ion beam lithography, as well as for basic ion-solid interactions.

  13. Signals of strong electronic correlation in ion scattering processes

    NASA Astrophysics Data System (ADS)

    Bonetto, F.; Gonzalez, C.; Goldberg, E. C.

    2016-05-01

    Previous measurements of neutral atom fractions for S r+ scattered by gold polycrystalline surfaces show a singular dependence with the target temperature. There is still not a theoretical model that can properly describe the magnitude and the temperature dependence of the neutralization probabilities found. Here, we applied a first-principles quantum-mechanical theoretical formalism to describe the time-dependent scattering process. Three different electronic correlation approaches consistent with the system analyzed are used: (i) the spinless approach, where two charge channels are considered (S r0 and S r+ ) and the spin degeneration is neglected; (ii) the infinite-U approach, with the same charge channels (S r0 and S r+ ) but considering the spin degeneration; and (iii) the finite-U approach, where the first ionization and second ionization energy levels are considered very, but finitely, separated. Neutral fraction magnitudes and temperature dependence are better described by the finite-U approach, indicating that e -correlation plays a significant role in charge-transfer processes. However, none of them is able to explain the nonmonotonous temperature dependence experimentally obtained. Here, we suggest that small changes in the surface work function introduced by the target heating, and possibly not detected by experimental standard methods, could be responsible for that singular behavior. Additionally, we apply the same theoretical model using the infinite-U approximation for the Mg-Au system, obtaining an excellent description of the experimental neutral fractions measured.

  14. Stability of Menisci in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Mazuruk, Konstantin; Volz, Martin P.

    2013-01-01

    Detached growth, also referred to as dewetted growth, is a Bridgman crystal growth process in which the melt is in contact with the crucible wall but the crystal is not. A meniscus bridges the gap between the top of the crystal and the crucible wall. The meniscus shape depends on the contact angle of the melt with the crucible wall, the growth angle of the melt with respect to the solidifying crystal, the gas pressure differential, the Weber number describing the rotation rate of the crucible, and the Bond number. Only some of the meniscus shapes are stable and the stability criterion is the sign of the second variation of the potential energy upon admissible meniscus shape perturbations. The effects of confined gas volumes above and below the melt and crucible rotation are evaluated. The analysis is applicable to the non-stationary case where the crystal radius changes during growth. Static stability maps (crystal radius versus pressure differential) are obtained for a series of Bond numbers, growth angles and Weber numbers. Also, the specific cases of Ge and InSb, in both terrestrial and microgravity conditions, are analyzed. Stability was found to depend significantly on whether the interior surface was considered to be microscopically rough or smooth, corresponding to pinned or unpinned states. It was also found that all meniscus shapes are statically stable in a microgravity environment.

  15. An argon ion beam milling process for native AlOx layers enabling coherent superconducting contacts

    NASA Astrophysics Data System (ADS)

    Grünhaupt, Lukas; von Lüpke, Uwe; Gusenkova, Daria; Skacel, Sebastian T.; Maleeva, Nataliya; Schlör, Steffen; Bilmes, Alexander; Rotzinger, Hannes; Ustinov, Alexey V.; Weides, Martin; Pop, Ioan M.

    2017-08-01

    We present an argon ion beam milling process to remove the native oxide layer forming on aluminum thin films due to their exposure to atmosphere in between lithographic steps. Our cleaning process is readily integrable with conventional fabrication of Josephson junction quantum circuits. From measurements of the internal quality factors of superconducting microwave resonators with and without contacts, we place an upper bound on the residual resistance of an ion beam milled contact of 50 mΩ μm2 at a frequency of 4.5 GHz. Resonators for which only 6% of the total foot-print was exposed to the ion beam milling, in areas of low electric and high magnetic fields, showed quality factors above 106 in the single photon regime, and no degradation compared to single layer samples. We believe these results will enable the development of increasingly complex superconducting circuits for quantum information processing.

  16. Controlling Ion and UV/VUV Photon Fluxes in Pulsed Low Pressure Plasmas for Materials Processing

    NASA Astrophysics Data System (ADS)

    Tian, Peng; Kushner, Mark J.

    2012-10-01

    UV/VUV photon fluxes in plasma materials processing have a variety of effects ranging from damaging to synergistic. To optimize these processes, it is desirable to have separate control over the fluxes of ions and photons, or at least be able to control their relative fluxes or overlap in time. Pulsed plasmas may provide such control as the rates at which ion and photon fluxes respond to the pulse power deposition are different. Results from a computational investigation of pulsed plasmas will be discussed to determine methods to control the ratio of ion to photon fluxes. Simulations were performed using a 2-dimensional plasma hydrodynamics model which addresses radiation transport using a Monte Carlo Simulation. Radiation transport is frequency resolved using partial-frequency-redistribution algorithms. Results for low pressure (10s of mTorr) inductively and capacitively coupled plasmas in Ar/Cl2 mixtures will be discussed while varying duty cycle, reactor geometry, gas mixture and pressure. We found that the time averaged ratio of VUV photon-to-ion fluxes in ICPs can be controlled with duty cycle of the pulsed power. Even with radiation trapping, photon fluxes tend to follow the power pulse whereas due to their finite response times, fluxes of ions tend to average the power pulse. Due to the overshoot in electron temperature that occurs at the start of low-duty-cycle pulses, disproportionately large photon fluxes (compared to ion fluxes) can be generated.

  17. Recent developments on ion-exchange membranes and electro-membrane processes.

    PubMed

    Nagarale, R K; Gohil, G S; Shahi, Vinod K

    2006-02-28

    Rapid growth of chemical and biotechnology in diversified areas fuels the demand for the need of reliable green technologies for the down stream processes, which include separation, purification and isolation of the molecules. Ion-exchange membrane technologies are non-hazardous in nature and being widely used not only for separation and purification but their application also extended towards energy conversion devices, storage batteries and sensors etc. Now there is a quite demand for the ion-exchange membrane with better selectivities, less electrical resistance, high chemical, mechanical and thermal stability as well as good durability. A lot of work has been done for the development of these types of ion-exchange membranes during the past twenty-five years. Herein we have reviewed the preparation of various types of ion-exchange membranes, their characterization and applications for different electro-membrane processes. Primary attention has been given to the chemical route used for the membrane preparation. Several general reactions used for the preparation of ion-exchange membranes were described. Methodologies used for the characterization of these membranes and their applications were also reviewed for the benefit of readers, so that they can get all information about the ion-exchange membranes at one platform. Although there are large number of reports available regarding preparations and applications of ion-exchange membranes more emphasis were predicted for the usefulness of these membranes or processes for solving certain type of industrial or social problems. More efforts are needed to bring many products or processes to pilot scale and extent their applications.

  18. Oxygen-assisted purification of platinum structures deposited by ion and electron beam induced processes

    NASA Astrophysics Data System (ADS)

    Perez-Roldan, M. J.; Mulders, J. J. L.; Trompenaars, P. H. F.

    2017-05-01

    Purification in the presence of O2 flux is investigated in platinum structures grown by ion and electron beam induced deposition processes using a standard precursor, MeCpPtMe3. Two different room temperature purification processes are evaluated. In the first process, the purification is obtained by simultaneously supplying oxygen and precursor gas during the deposition. In the second process, an in situ post-treatment is performed on deposited structures by electron irradiation in the presence of oxygen. The first process applied to electron beam deposition requires a high flux of oxygen to improve the purification efficiency, while application to ion beam deposition requires a lower oxygen flux to enhance purification while avoiding an additional increase of the milling process. Both purification processes result in high purity Pt depositions and a reduction of deposition yields. For the ion beam, the electrical resistivity only drops for the first purification process: deposition supplying simultaneously oxygen and gas precursor. The second process of electron post irradiation does result in compositional changes, including reduced amounts of carbon but does not result in improvements in resistivity. For the electron beam, the resistivity shows a significant reduction applying both purification processes in sequence: in this way a resistivity of 22.5 µΩ cm has been obtained which is only twice the bulk value for Pt.

  19. Structural Development of an Oceanic Detachment Fault System, Atlantis Bank, Southwest Indian Ridge

    NASA Astrophysics Data System (ADS)

    Miranda, E. A.; John, B. E.; Hirth, G.; Dick, H.

    2002-12-01

    In slow-spreading environments, both magmatic and tectonic processes accommodate spreading, where the latter can be manifested in the form of an extensional detachment fault system. The detachment fault system of Atlantis Bank, an oceanic core complex formed at the intersection of the Southwest Indian Ridge and the Atlantis II transform, is dissected by transform-parallel normal faults that provide unique cross-sections through all levels of the detachment fault system. Gabbros and peridotite collected in ODP Hole 735B and with the manned submersible Shinkai 6500 were located structurally beneath, within, and above the main detachment fault surface along the exposed length of the detachment fault system that correspond to roughly 2 Ma of crustal accretion. The samples are ideal for interpreting the process of strain localization and fabric development associated with the formation of oceanic detachment faults. Analysis of the{ \\it in situ} dive samples and continuous core from Hole 735B indicate that the main shear zone associated with the detachment fault is at least 500m thick. The deepest levels of the shear zone are characterized by a 50-m thick zone of unfoliated or weakly foliated granulite grade rocks. The granulite deformation continues upward but is strongly overprinted by a 150-m zone of penetrative amphibolite facies protomylonitic and mylonitic fabrics. A 300-m thick zone of well-foliated amphibolite facies rocks lies above the overprinted granulite. The amphibolites contain 20-30 mm wide, fine-grained shear zones that increase in abundance upward towards the main, brittle detachment fault. These rocks exhibit a greenschist grade deformation characterized by a cataclastic overprint of crystal-plastically deformed plagioclase and brown amphibole within the layers of the mylonitic foliation, and the growth of green amphibole "coronas" around brown amphibole; these relationships preserve the transition from high-temperature ductile deformation to lower

  20. Folding of a detachment and fault - Modified detachment folding along a lateral ramp, southwestern Montana, USA

    NASA Astrophysics Data System (ADS)

    Schmidt, Christopher; Whisner, S. Christopher; Whisner, Jennifer B.

    2014-12-01

    The inversion of the Middle Proterozoic Belt sedimentary basin during Late Cretaceous thrusting in Montana produced a large eastwardly-convex salient, the southern boundary of which is a 200 km-long oblique to lateral ramp subtended by a detachment between the Belt rocks and Archean basement. A 10 km-long lateral ramp segment exposes the upper levels of the detachment where hanging wall Belt rocks have moved out over the Paleozoic and Mesozoic section. The hanging wall structure consists of a train of high amplitude, faulted, asymmetrical detachment folds. Initial west-east shortening produced layer parallel shortening fabrics and dominantly strike slip faulting followed by symmetrical detachment folding. 'Lock-up' of movement on the detachment surface produced regional simple shear and caused the detachment folds to become asymmetrical and faulted. Folding of the detachment surface after lock-up modified the easternmost detachment folds further into a southeast-verging, overturned fold pair with a ramp-related fault along the base of the stretched mutual limb.

  1. Results from recent detachment experiments in alternative divertor configurations on TCV

    NASA Astrophysics Data System (ADS)

    Theiler, C.; Lipschultz, B.; Harrison, J.; Labit, B.; Reimerdes, H.; Tsui, C.; Vijvers, W. A. J.; Boedo, J. A.; Duval, B. P.; Elmore, S.; Innocente, P.; Kruezi, U.; Lunt, T.; Maurizio, R.; Nespoli, F.; Sheikh, U.; Thornton, A. J.; van Limpt, S. H. M.; Verhaegh, K.; Vianello, N.; the TCV Team; the EUROfusion MST1 Team

    2017-07-01

    Divertor detachment is explored on the TCV tokamak in alternative magnetic geometries. Starting from typical TCV single-null shapes, the poloidal flux expansion at the outer strikepoint is varied by a factor of 10 to investigate the X-divertor characteristics, and the total flux expansion is varied by 70 % to study the properties of the super-X divertor. The effect of an additional X-point near the target is investigated in X-point target divertors. Detachment of the outer target is studied in these plasmas during Ohmic density ramps and with the ion \

  2. Effects of near soil surface characteristics on soil detachment by overland flow in a natural succession grassland

    USDA-ARS?s Scientific Manuscript database

    Vegetation restoration probably has great effects on the process of soil detachment. This study was conducted to investigate the effects of near soil surface characteristics on soil detachment by overland flow in a 7-year naturally restored grassland. Four treatments were designed to characterize th...

  3. A mechanical model of retinal detachment

    NASA Astrophysics Data System (ADS)

    Chou, Tom; Siegel, Michael

    2012-08-01

    We present a model of the mechanical and fluid forces associated with exudative retinal detachments where the retinal photoreceptor cells separate, typically from the underlying retinal pigment epithelium (RPE). By computing the total fluid volume flow arising from transretinal, vascular and RPE pump currents, we determine the conditions under which the subretinal fluid pressure exceeds the maximum yield stress holding the retina and RPE together, giving rise to an irreversible, extended retinal delamination. We also investigate localized, blister-like retinal detachments by balancing mechanical tension in the retina with both the retina-RPE adhesion energy and the hydraulic pressure jump across the retina. For detachments induced by traction forces, we find a critical radius beyond which the blister is unstable to growth. Growth of a detached blister can also be driven by inflamed lesions in which the tissue has a higher choroidal hydraulic conductivity, has insufficient RPE pump activity, or has defective adhesion bonds. We determine the parameter regimes in which the blister either becomes unstable to growth, remains stable and finite-sized, or shrinks, allowing possible healing. The corresponding stable blister radius and shape are calculated. Our analysis provides a quantitative description of the physical mechanisms involved in exudative retinal detachments and can help guide the development of retinal reattachment protocols or preventative procedures.

  4. Summary of Industry-Academia Collaboration Projects on Cluster Ion Beam Process Technology

    NASA Astrophysics Data System (ADS)

    Yamada, Isao; Matsuo, Jiro; Toyoda, Noriaki

    2008-11-01

    Processes employing clusters of ions comprised of a few hundred to many thousand atoms are now being developed into a new field of ion beam technology. Cluster-surface collisions produce important non-linear effects which are being applied to shallow junction formation, to etching and smoothing of semiconductors, metals, and dielectrics, to assisted formation of thin films with nano-scale accuracy, and to other surface modification applications. In 2000, a four year R&D project for development of industrial technology began in Japan under funding from the New Energy and Industrial Technology Development Organization (NEDO). Subjects of the projects are in areas of equipment development, semiconductor surface processing, high accuracy surface processing and high-quality film formation. In 2002, another major cluster ion beam project which emphasized nano-technology applications has started under a contract from the Ministry of Economy and Technology for Industry (METI). This METI project involved development related to size-selected cluster ion beam equipment and processes, and development of GCIB processes for very high rate etching and for zero damage etching of magnetic materials and compound semiconductor materials. This paper describes summery of the results.

  5. Defects creation in sapphire by swift heavy ions: A fluence depending process

    NASA Astrophysics Data System (ADS)

    Kabir, A.; Meftah, A.; Stoquert, J. P.; Toulemonde, M.; Monnet, I.

    2009-03-01

    Single crystals of sapphire (α-Al 2O 3) were irradiated at GANIL with 0.7 MeV/amu xenon ions corresponding to an electronic stopping power of 21 keV/nm. Several fluences were applied between 5 × 10 11 and 2 × 10 14 ions/cm 2. Irradiated samples were characterized using optical absorption spectroscopy. This technique exhibited the characteristic bands associated with F and F + centers defects. The F centers density was found to increase with the fluence following two different kinetics: a rapid increase for fluences less than 10 13 ions/cm 2 and then, a slow increase for higher fluences. For fluences less than 10 13 ions/cm 2, results are in good agreement with those obtained by Canut et al. [B. Canut, A. Benyagoub, G. Marest, A. Meftah, N. Moncoffre, S.M.M. Ramos, F. Studer, P. Thévenard, M. Toulemonde, Phys. Rev. B 51 (1995) 12194]. In the fluences range: 10 13-10 14 ions/cm 2, the F centers defects creation process is found to be different from the one evidenced for fluences less than 10 13 ions/cm 2.

  6. Influence of ion source configuration and its operation parameters on the target sputtering and implantation process.

    PubMed

    Shalnov, K V; Kukhta, V R; Uemura, K; Ito, Y

    2012-06-01

    In the work, investigation of the features and operation regimes of sputter enhanced ion-plasma source are presented. The source is based on the target sputtering with the dense plasma formed in the crossed electric and magnetic fields. It allows operation with noble or reactive gases at low pressure discharge regimes, and, the resulting ion beam is the mixture of ions from the working gas and sputtering target. Any conductive material, such as metals, alloys, or compounds, can be used as the sputtering target. Effectiveness of target sputtering process with the plasma was investigated dependently on the gun geometry, plasma parameters, and the target bias voltage. With the applied accelerating voltage from 0 to 20 kV, the source can be operated in regimes of thin film deposition, ion-beam mixing, and ion implantation. Multi-component ion beam implantation was applied to α-Fe, which leads to the surface hardness increasing from 2 GPa in the initial condition up to 3.5 GPa in case of combined N(2)-C implantation. Projected range of the implanted elements is up to 20 nm with the implantation energy 20 keV that was obtained with XPS depth profiling.

  7. Kinetic dynamics simulation of the detached plasma

    NASA Astrophysics Data System (ADS)

    Pianpanit, Theerasarn; Ishiguro, Seiji; Hasegawa, Hiroki

    2015-11-01

    The detached plasma has been proposed to reduce the heat flux to the divertor. Fluid code has been widely used to investigate the detached plasma but the cooling of plasma, trapped particle effects, and other kinetic dynamics in the detached plasma has not been well understood. Particle-in-Cell (PIC) simulation with the Monte Carlo collisions and the cumulative scattering angle coulomb collision are carried out to study dynamical kinetic behavior of the plasma. The constant pressure and temperature of neutral gas box in front of the divertor target model has been used in the simulation. The results show the decrease in electron temperature in front of the divertor plate strongly relate to the Coulomb collision frequency.

  8. Evaluation of the ion implantation process for production of solar cells from silicon sheet materials

    NASA Technical Reports Server (NTRS)

    Spitzer, M. B.

    1983-01-01

    The objective of this program is the investigation and evaluation of the capabilities of the ion implantation process for the production of photovoltaic cells from a variety of present-day, state-of-the-art, low-cost silicon sheet materials. Task 1 of the program concerns application of ion implantation and furnace annealing to fabrication of cells made from dendritic web silicon. Task 2 comprises the application of ion implantation and pulsed electron beam annealing (PEBA) to cells made from SEMIX, SILSO, heat-exchanger-method (HEM), edge-defined film-fed growth (EFG) and Czochralski (CZ) silicon. The goals of Task 1 comprise an investigation of implantation and anneal processes applied to dendritic web. A further goal is the evaluation of surface passivation and back surface reflector formation. In this way, processes yielding the very highest efficiency can be evaluated. Task 2 seeks to evaluate the use of PEBA for various sheet materials. A comparison of PEBA to thermal annealing will be made for a variety of ion implantation processes.

  9. Preface: Photon and fast Ion induced Processes in Atoms, MOlecules and Nanostructures (PIPAMON)

    NASA Astrophysics Data System (ADS)

    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.

  10. Single and multilayered materials processing by argon ion beam etching: study of ion angle incidence and defect formation

    NASA Astrophysics Data System (ADS)

    Gosset, N.; Boufnichel, M.; Bahette, E.; Khalfaoui, W.; Ljazouli, R.; Grimal-Perrigouas, V.; Dussart, R.

    2015-09-01

    Ion beam etching (IBE) is a very promising technique in microelectronics because of its capability to etch small patterns with a high resolution and inert materials. In this study, the angular incidence of an argon ion beam on the etch rate and uniformity is discussed in the case of several materials often used in microelectronics. The capability of the IBE technique to etch multilayered stack samples with positive anisotropic profiles was demonstrated on TiNiAu, TiNiCuAu, BST and PZT. Two typical defects involved in IBE processing (fences and not etched pattern foots) due to shadow masking and redeposition effect, are explained and solutions are presented to avoid them. Deep IBE was performed on GaN with an etch depth as high as 10 μm, using a 8 μm thick SiO2 mask. The etching of other mask materials, such as TiN, was investigated in order to improve the selectivity. Using a TiN mask, a selectivity to GaN as high as 5 is reported. Finally, the etch rate enhancement needed for deep etching was studied.

  11. Engineering study for the treatment of spent ion exchange resin resulting from nuclear process applications

    SciTech Connect

    Place, B.G.

    1990-09-01

    This document is an engineering study of spent ion exchange resin treatment processes with the purpose of identifying one or more suitable treatment technologies. Classifications of waste considered include all classes of low-level waste (LLW), mixed LLW, transuranic (TRU) waste, and mixed TRU waste. A total of 29 process alternatives have been evaluated. Evaluation parameters have included economic parameters (both total life-cycle costs and capital costs), demonstrated operability, environmental permitting, operational availability, waste volume reduction, programmatic consistency, and multiple utilization. The results of this study suggest that there are a number of alternative process configurations that are suitable for the treatment of spent ion exchange resin. The determinative evaluation parameters were economic variables (total life-cycle cost or capital cost) and waste volume reduction. Immobilization processes are generally poor in volume reduction. Thermal volume reduction processes tend to have high capital costs. There are immobilization processes and thermal volume reduction processes that can treat all classifications of spent ion exchange resin likely to be encountered. 40 refs., 19 figs., 17 tabs.

  12. Observation of thermal electron detachment from cyclo-C4F8- in FALP experiments

    NASA Astrophysics Data System (ADS)

    Miller, Thomas M.; Morris, Robert A.; Stevens Miller, Amy E.; Viggiano, A. A.; Paulson, John F.

    1994-08-01

    The methodology for use of a flowing afterglow--Langmuir probe apparatus to measure thermal electron detachment rate coefficients is described. We determined the thermal detachment rate coefficient (1010 ± 300 s-1) for cyclo-C4F8- ions and the rate coefficient (1.6 ± × 10-8 cm3 s-1) for electron attachment of cyclo-C4F8 at 375 K. The sole ionic product of attachment is cyclo-C4F8-. The equilibrium constant for the attachment/detachment reaction yields a free energy for attachment at 375 K of -0.63 ± 0.02 eV, from which we estimate the electron affinity (0 K value) of cyclo-C4F8 to be about 0.63 eV.

  13. [Binocular vision after treatment of retinal detachment].

    PubMed

    Maksymowicz, Małgorzata; Raczyńska, Krystyna; Maksymowicz, Jarosław

    2003-01-01

    The study covered 79 patients after treatment of retinal detachment. Double vision, strabismus and disturbances of eyeballs motility were found. Up to 12 months after intervention, the deterioration of binocular vision was observed in 48.28 to 89.66% of patients, depending on the method used. The majority of disturbances were observed during the first 3 months with tendency to gradual subsidence during consecutive 9 months. A patient, after treatment of retinal detachment, can be qualified to return to work where stereopsis is needed under condition that ophthalmologic examination is done every three months during the first year after operation and than once a year.

  14. A simple analytical solution for slab detachment

    NASA Astrophysics Data System (ADS)

    Schmalholz, Stefan M.

    2011-04-01

    An analytical solution is presented for the nonlinear dynamics of high amplitude necking in a free layer of power-law fluid extended in layer-parallel direction due to buoyancy stress. The solution is one-dimensional (1-D) and contains three dimensionless parameters: the thinning factor (i.e. ratio of current to initial layer thickness), the power-law stress exponent, n, and the ratio of time to the characteristic deformation time of a viscous layer under buoyancy stress, t/ tc. tc is the ratio of the layer's effective viscosity to the applied buoyancy stress. The value of tc/ n specifies the time for detachment, i.e. the time it takes until the layer thickness has thinned to zero. The first-order accuracy of the 1-D solution is confirmed with 2-D finite element simulations of buoyancy-driven necking in a layer of power-law fluid embedded in a linear or power-law viscous medium. The analytical solution is accurate within a factor about 2 if the effective viscosity ratio between the layer and the medium is larger than about 100 and if the medium is a power-law fluid. The analytical solution is applied to slab detachment using dislocation creep laws for dry and wet olivine. Results show that one of the most important parameters controlling the dynamics of slab detachment is the strength of the slab which strongly depends on temperature and rheological parameters. The fundamental conclusions concerning slab detachment resulting from both the analytical solution and from earlier published thermo-mechanical numerical simulations agree well, indicating the usefulness of the highly simplified analytical solution for better understanding slab detachment. Slab detachment resulting from viscous necking is a combination of inhomogeneous thinning due to varying buoyancy stress within the slab and a necking instability due to the power-law viscous rheology ( n > 1). Application of the analytical solution to the Hindu Kush slab provides no "order-of-magnitude argument" against

  15. Retinal detachment after open globe injury.

    PubMed

    Stryjewski, Tomasz P; Andreoli, Christopher M; Eliott, Dean

    2014-01-01

    To characterize the development of retinal detachment (RD) after open globe trauma. Case-control study. A total of 892 patients comprising 893 open globe injuries (OGIs), of whom 255 were ultimately diagnosed with RD, with the remaining eyes serving as controls. Retrospective chart review of patients with OGIs presenting to the Massachusetts Eye and Ear Infirmary between 1999 and 2011. Kaplan-Meier analysis was used to estimate the time to detachment, and multivariable logistic regression was used to define the clinical factors associated with RD after OGI. Demographic and clinical characteristics at the time of presentation after OGI, date of RD diagnosis, and last date of follow-up. Primary repair of the open globe was typically undertaken within hours of presentation. A total of 255 eyes were ultimately diagnosed with RD after open globe trauma, yielding an incidence of 29% (95% confidence interval, 26-32). For eyes that developed RD, 27% (69/255) detached within 24 hours of primary open globe repair, 47% (119/255) detached within 1 week, and 72% (183/255) detached within 1 month. Multivariable regression analysis revealed the presence of vitreous hemorrhage (odds ratio [OR], 7.29; P < 0.001), higher zone of injury (OR, 2.51 per integer increase in zone number; OR, 1.00-6.30; P < 0.001), and poorer logarithm of the minimum angle of resolution (logMAR) visual acuity at the time of presentation after OGI (OR, 2.41 per integer increase in logMAR visual acuity; OR, 1.00-81.30; P < 0.001) to be associated with RD. A screening tool was created: the Retinal Detachment after Open Globe Injury score. Retinal detachment is common after open globe trauma, although often not appearing until days to weeks after the initial traumatic event. Several clinical variables at the time of initial presentation can predict the future risk of detachment. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  16. Basis document for PFP plutonium nitrate ion exchange process in Room 228A

    SciTech Connect

    Risenmay, H.R.

    1997-04-23

    The PFP facility currently has approximately 4300 liters of plutonium nitrate solution in storage. This material will be calcined by the Vertical Denigration Calciner (VDC) located in room 230C. However, part of the material needs to be purified to remove constituents that will interfere with the calcination process. An Ion Exchange process using Reillex{trademark} HPQ anion exchange resin was tested by the Plutonium Process Support Laboratories (PPSL) (I). The Ion exchange process is to be installed in glovebox HC-7 in room 228A/234-5Z. The plutonium separated from the interfering constituents will be in a concentrated condition ready to be calcined by the VDC in room 230C. The oxide product of the VDC will be placed into the 2736-Z vaults for long term storage.

  17. Keratinocyte detachment-differentiation connection revisited, or anoikis-pityriasi nexus redux.

    PubMed

    Banno, Tomohiro; Blumenberg, Miroslav

    2014-01-01

    Epidermis, a continuously self-renewing and differentiating organ, produces a protective stratum corneum that shields us from external chemical, physical and microbial threats. Epidermal differentiation is a multi-step process regulated by influences, some unknown, others insufficiently explored. Detachment of keratinocytes from the basement membrane is one such pro-differentiation stimulus. Here, we define the transcriptional changes during differentiation, especially those caused by detachment from the substratum. Using comprehensive transcriptional profiling, we revisited the effects of detachment as a differentiation signal to keratinocytes. We identified the genes regulated by detachment, the corresponding ontological categories and, using metaanalysis, compared the genes and categories to those regulated by other pro-differentiating stimuli. We identified 762 genes overexpressed in suspended keratinocyte, including known and novel differentiation markers, and 1427 in attached cells, including basal layer markers. Detachment induced epidermis development, cornification and desmosomal genes, but also innate immunity, proliferation inhibitors, transcription regulators and MAPKs; conversely the attached cells overexpressed cell cycle, anchoring, motility, splicing and mitochondrial genes, and both positive and negative regulators of apoptosis. Metaanalysis identified which detachment-regulated categories overlap with those induced by suprabasal location in vivo, by reaching confluency in vitro, and by inhibition of JUN kinases. Attached and in vivo basal cells shared overexpression of mitochondrial components. Interestingly, melanosome trafficking components were also overexpressed in the attached and in vivo basal keratinocytes. These results suggest that specific pro-differentiation signals induce specific features of the keratinization process, which are in vivo orchestrated into harmonious epidermal homeostasis.

  18. Keratinocyte Detachment-Differentiation Connection Revisited, or Anoikis-Pityriasi Nexus Redux

    PubMed Central

    Banno, Tomohiro; Blumenberg, Miroslav

    2014-01-01

    Epidermis, a continuously self-renewing and differentiating organ, produces a protective stratum corneum that shields us from external chemical, physical and microbial threats. Epidermal differentiation is a multi-step process regulated by influences, some unknown, others insufficiently explored. Detachment of keratinocytes from the basement membrane is one such pro-differentiation stimulus. Here, we define the transcriptional changes during differentiation, especially those caused by detachment from the substratum. Using comprehensive transcriptional profiling, we revisited the effects of detachment as a differentiation signal to keratinocytes. We identified the genes regulated by detachment, the corresponding ontological categories and, using metaanalysis, compared the genes and categories to those regulated by other pro-differentiating stimuli. We identified 762 genes overexpressed in suspended keratinocyte, including known and novel differentiation markers, and 1427 in attached cells, including basal layer markers. Detachment induced epidermis development, cornification and desmosomal genes, but also innate immunity, proliferation inhibitors, transcription regulators and MAPKs; conversely the attached cells overexpressed cell cycle, anchoring, motility, splicing and mitochondrial genes, and both positive and negative regulators of apoptosis. Metaanalysis identified which detachment-regulated categories overlap with those induced by suprabasal location in vivo, by reaching confluency in vitro, and by inhibition of JUN kinases. Attached and in vivo basal cells shared overexpression of mitochondrial components. Interestingly, melanosome trafficking components were also overexpressed in the attached and in vivo basal keratinocytes. These results suggest that specific pro-differentiation signals induce specific features of the keratinization process, which are in vivo orchestrated into harmonious epidermal homeostasis. PMID:24960166

  19. Membrane permeation process for dehydration of organic liquid mixtures using sulfonated ion-exchange polyalkene membranes

    DOEpatents

    Cabasso, Israel; Korngold, Emmanuel

    1988-01-01

    A membrane permeation process for dehydrating a mixture of organic liquids, such as alcohols or close boiling, heat sensitive mixtures. The process comprises causing a component of the mixture to selectively sorb into one side of sulfonated ion-exchange polyalkene (e.g., polyethylene) membranes and selectively diffuse or flow therethrough, and then desorbing the component into a gas or liquid phase on the other side of the membranes.

  20. Neutron scattering for analysis of processes in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Balagurov, A. M.; Bobrikov, I. A.; Samoylova, N. Yu; Drozhzhin, O. A.; Antipov, E. V.

    2014-12-01

    The review is concerned with analysis and generalization of information on application of neutron scattering for elucidation of the structure of materials for rechargeable energy sources (mainly lithium-ion batteries) and on structural rearrangements in these materials occurring in the course of electrochemical processes. Applications of the main methods including neutron diffraction, small-angle neutron scattering, inelastic neutron scattering, neutron reflectometry and neutron introscopy are considered. Information on advanced neutron sources is presented and a number of typical experiments are outlined. The results of some studies of lithium-containing materials for lithium-ion batteries, carried out at IBR-2 pulsed reactor, are discussed. The bibliography includes 50 references.

  1. Planar optical coupling elements for multimode fibers with two-step ion migration process

    NASA Astrophysics Data System (ADS)

    Viljanen, J.; Leppihalme, M.

    1981-01-01

    An electric field assisted two-step ion migration process in soda-lime glass plates has been used to produce optical couple waveguides with semicircular and circular cross sections. The radius and the numerical aperture of the guides are approximately the same as those of the graded index multimode fibers. A new coupler structure, the edge reflecting element, which could be used as an integrated demultiplexer in wavelength division multiplexing, has been fabricated. The loss spectrum of the waveguides is analyzed and a theoretical treatment of the ion concentrations is given.

  2. Non-Contact Wafer Fabrication Process Using Gas Cluster Ion Beams

    SciTech Connect

    Toyoda, Noriaki; Yamada, Iaso; Isogai, Hiromichi

    2008-11-03

    Gas cluster ion beam (GCIB) was used for precise wafer fabrication process. GCIB realizes a quite low-energy ion beam and shows very precise and good repeatability. To obtain thickness uniformity of Si over the whole wafer, small beam diameter ({approx}4 mm) of GCIB was used. Thickness variations on the wafer can be reduced by location specific irradiation of collimated GCIB. By controlling the scan speed of GCIB irradiation based on the removal thickness at each irradiation position, thickness and height uniformity of Si can be improved to several tens of nm. In addition, etching enhancement by using Ar/SF{sub 6} mixed cluster was studied.

  3. A Novel Process for Recovering Valuable Materials from Spent Lithium-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Dodbiba, Gjergj; Yamaji, Yuta; Murata, Kenji; Okaya, Katsunori; Shibayama, Atsushi; Fujita, Toyohisa

    The demand for lithium-ion batteries has been increasing due to the increasing demand for laptop computers, cellular phones, automobiles, etc. The positive electrode of the lithium-ion secondary battery is mainly made of lithium oxides well as cobalt, nickel, manganese, etc. Thus, an effective recycling method not only would collect cobalt and lithium, but also would enable the separation of other materials from the spent batteries. In this work, a novel processing flow sheet is put forward and its efficiency is evaluated. The aim was to obtain pure fractions of various constituents.

  4. Simulating Divertor Detachment of Ohmic Discharges in ASDEX Upgrade Using SOLPS: the Role of Carbon

    SciTech Connect

    Wischmeier, M; Coster, D; Chankin, A; Fuchs, C; Groth, M; Harhausen, J; Kallenbach, A; Muller, H; Tsalas, M; Wolfrum, E

    2007-06-27

    With divertor detachment being a prerequisite for burning plasma operation in ITER, numerical codes such as SOLPS [1] have been developed for predicting and interpreting the divertor performance at all operational regimes in current tokamaks and ITER. In ITER complete detachment from the outer divertor target is not permitted as this might result in an X-point MARFE, imposing an upper limit for the upstream separatrix density, n{sub e}{sup sep}. Despite the knowledge of the basic mechanisms required for achieving detachment, such as radiative power exhaust, volumetric momentum and charge removal [1], a quantitative evaluation of experimentally observed detached regimes proves to be particularly difficult for several tokamaks. In particular the strong asymmetry of the ion flux density between the inner, {Lambda}{sub it}, and the outer target {Lambda}{sub ot} with increasing line averaged density, {bar n}{sub e}, and in particular ''vanishing'' of the ion flux, defined as full/complete detachment, at the inner target cannot be reproduced. It is unclear how this is related to divertor target plates or other plasma facing components containing carbon. As part of a combined effort at various experimental devices this paper contributes to the validation of the SOLPS code against experimental data from ASDEX Upgrade, AUG, at the onset of divertor detachment. In the framework established under the International Tokamak Physics Activity (ITPA) Divertor and SOL working group a series of ohmic discharges have been performed in AUG, which had as similar as possible plasma parameters as companion discharges undertaken in DIII-D [2]. The effect of activating drift terms, the influence of the chemical sputtering yield at the inner target and in addition to [3] the role of impurity influx from the inner heat shield are analyzed.

  5. Effect of Magnetic Field Gradient on Plasma Detachment Induced by Breaking of Adiabatic Plasma Expansion

    NASA Astrophysics Data System (ADS)

    Chung, K. S.; Kim, June Young; Chung, Kyoung-Jae; Hwang, Y. S.

    2016-10-01

    A magnetic field gradient that is a variation in the magnetic field around the ion flow has been investigated as a primary parameter for ion detachment in the magnetic nozzle geometries. Some scale lengths of magnetic field are controlled by two solenoid coils outside the diffusion chamber of a ECR-driven linear plasma device. The axial and radial profiles of the plasma potential and electron temperature are measured by a Langmuir probe array for the various magnetic field configurations in the downstream. The local adiabaticity, strong constant magnetic moment, is satisfied with a linear relationship between the change in effective electron temperature and the change in plasma potential in the low magnetic field gradient. Whereas, with an increasing non-homogeneity of the magnetic field in the direction of the flow, the breaking of adiabatic plasma expansion is identified to measure the nonlinear process which is the variation for an adiabatic exponent. Such the loss of adiabaticity is also explained in terms of non-adiabaticity parameter i.e. degree of demagnetization. This research was supported by National R&D Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (Nos. 2014M1A7A1A02030165 and 2014M1A7A1A03045367).

  6. TRANSIENT HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE WASTE REMOVAL PROCESS

    SciTech Connect

    Lee, S.

    2010-07-12

    The small column ion exchange (SCIX) process treats low curie salt (LCS) waste before feeding it to the saltstone facility to be made into grout. Through this process, radioactive cesium from the salt solution is absorbed into the CST bed. A CST column loaded with radioactive cesium will generate significant heat from radiolytic decay. If engineering designs of the CST sorption column can not handle this thermal load, hot spots may develop locally within the column and degrade the performance of the ion-exchange process. The CST starts to degrade at about 80 to 85 C, and the CST completely changes to another material above 120 C. In addition, the process solution will boil around 130 C. If the column boiled dry, the sorbent could plug the column and require replacement of the column module. The objective of the present work is to compute temperature distributions across the column as a function of transit time after the initiation of accidents when there is loss of the salt solution flow in the CST column under abnormal conditions of the process operations. In this situation, the customer requested that the calculations should be conservative in that the model results would show the maximum centerline temperatures achievable by the CST design configurations. The thermal analysis results will be used to evaluate the fluid temperature distributions and the process component temperatures within the ion exchange system. This information will also assist in the system design and maintenance.

  7. Two-stage Uplift of Granite-Gneiss-Migmatite Complex (GGMC) of Çataldaǧ Core Complex (Western Anatolia, Turkey): the role of detachment faults on uplift processes

    NASA Astrophysics Data System (ADS)

    Kamaci, Omer; Altunkaynak, Safak

    2016-04-01

    The most recently identified core complex of western Anatolia (Turkey), the Çataldaǧ Core Complex (ÇCC) consists of a granite-gneiss-migmatite complex (GGMC) representing deep crustal rocks of NW Turkey and a shallow level granodioritic body (ÇG: Çataldaǧ granodiorite). The GGMC is Latest Eocene-Early Oligocene and ÇG is Early Miocene in age, and both were exhumed in the footwall of the Çataldaǧ Detachment Fault Zone (ÇDFZ) in the Early Miocene. On the basis of correlation of age data and the closure temperatures of zircon, monazite, muscovite, biotite and K-feldspar, the T-time history of GGMC reveals that GGMC has experienced at least two stages of cooling and uplift, from 33.8 to 30.1 Ma and 21.3 to 20.7 Ma. In stage I, from 33.8 to 30.1 Ma, the cooling rate of GGMC was relatively slow (35°C/my) however cooling rate increase dramatically to ≥500°C/my in stage II between 21.3 and 20.7 Ma. T-time history also indicate that GGMC was elevated to the final location in at least 8-13 My according to the monazite and zircon and mica ages obtained from the same rock. Rapid slab rollback at the Hellenic trench at ca. 23 Ma may have increased extension rates leading to the development of detachment faults (i.e. ÇDFZ), core complexes and associated syn-extensional granitoids in Western Anatolia and the Aegean extensional province.

  8. Negative ion treatment increases positive emotional processing in seasonal affective disorder.

    PubMed

    Harmer, C J; Charles, M; McTavish, S; Favaron, E; Cowen, P J

    2012-08-01

    Antidepressant drug treatments increase the processing of positive compared to negative affective information early in treatment. Such effects have been hypothesized to play a key role in the development of later therapeutic responses to treatment. However, it is unknown whether these effects are a common mechanism of action for different treatment modalities. High-density negative ion (HDNI) treatment is an environmental manipulation that has efficacy in randomized clinical trials in seasonal affective disorder (SAD). The current study investigated whether a single session of HDNI treatment could reverse negative affective biases seen in seasonal depression using a battery of emotional processing tasks in a double-blind, placebo-controlled randomized study. Under placebo conditions, participants with seasonal mood disturbance showed reduced recognition of happy facial expressions, increased recognition memory for negative personality characteristics and increased vigilance to masked presentation of negative words in a dot-probe task compared to matched healthy controls. Negative ion treatment increased the recognition of positive compared to negative facial expression and improved vigilance to unmasked stimuli across participants with seasonal depression and healthy controls. Negative ion treatment also improved recognition memory for positive information in the SAD group alone. These effects were seen in the absence of changes in subjective state or mood. These results are consistent with the hypothesis that early change in emotional processing may be an important mechanism for treatment action in depression and suggest that these effects are also apparent with negative ion treatment in seasonal depression.

  9. Current understanding of divertor detachment: experiments and modelling

    SciTech Connect

    Wischmeier, W; Groth, M; Kallenbach, A; Chankin, A; Coster, D; Dux, R; Herrmann, A; Muller, H; Pugno, R; Reiter, D; Scarabosio, A; Watkins, J; Team, T D; Team, A U

    2008-05-23

    A qualitative as well as quantitative evaluation of experimentally observed plasma parameters in the detached regime proves to be difficult for several tokamaks. A series of ohmic discharges have been performed in ASDEX Upgrade and DIII-D at similar as possible plasma parameters and at different line averaged densities, {bar n}{sub e}. The experimental data represent a set of well diagnosed discharges against which numerical simulations are compared. For the numerical modeling the fluid-code B2.5 coupled to the Monte Carlo neutrals transport code EIRENE is used. Only the combined enhancement of effects, such as geometry, drift terms, neutral conductance, increased radial transport and divertor target composition, explains a significant fraction of the experimentally observed asymmetries of the ion fluxes as a function of {bar n}{sub e} to the inner and outer target plates in ASDEX Upgrade. The relative importance of the mechanisms leading to detachment are different in DIII-D and ASDEX Upgrade.

  10. Visual recovery after macula-off retinal detachment.

    PubMed

    Ross, W H

    2002-07-01

    With modern surgical techniques to repair retinal detachments, a greater than 90% primary anatomic success rate can be expected. Despite this high level of anatomic success, visual results remain compromised mainly because of permanent functional damage once the macula becomes detached. The most important predictor of visual recovery after retinal detachment surgery is preoperative visual acuity. Preoperative acuity appears to be directly related to the height of macular detachment. Shorter duration of detachment and younger age are also important in visual recovery. This paper will review the current literature that helps to improve our understanding of visual recovery after macula-off retinal detachments.

  11. Ion distributions in the vicinity of Mars: Signatures of heating and acceleration processes

    NASA Astrophysics Data System (ADS)

    Nilsson, H.; Stenberg, G.; Futaana, Y.; Holmström, M.; Barabash, S.; Lundin, R.; Edberg, N. J. T.; Fedorov, A.

    2012-02-01

    More than three years of data from the ASPERA-3 instrument on-board Mars Express has been used to compile average distribution functions of ions in and around the Mars induced magnetosphere. We present samples of average distribution functions, as well as average flux patterns based on the average distribution functions, all suitable for detailed comparison with models of the near-Mars space environment. The average heavy ion distributions close to the planet form thermal populations with a temperature of 3 to 10 eV. The distribution functions in the tail consist of two populations, one cold which is an extension of the low altitude population, and one accelerated population of ionospheric origin ions. All significant fluxes of heavy ions in the tail are tailward. The heavy ions in the magnetosheath form a plume with the flow aligned with the bow shock, and a more radial flow direction than the solar wind origin flow. Summarizing the escape processes, ionospheric ions are heated close to the planet, presumably through wave-particle interaction. These heated populations are accelerated in the tailward direction in a restricted region. Another significant escape path is through the magnetosheath. A part of the ionospheric population is likely accelerated in the radial direction, out into the magnetosheath, although pick up of an oxygen exosphere may also be a viable source for this escape. Increased energy input from the solar wind during CIR events appear to mainly increase the number flux of escaping particles, the average energy of the escaping particles is not strongly affected. Heavy ions on the dayside may precipitate and cause sputtering of the atmosphere, though fluxes are likely lower than 0.4 × 1023 s-1.

  12. Damage Processes In MgO Irradiated With Medium-energy Heavy Ions

    SciTech Connect

    Moll, Sandra J.; Zhang, Y.; Debelle, A.; Thome, Lionel; Crocombette, J.-P.; Zhu, Zihua; Jagielski, Jacek; Weber, William J.

    2015-04-01

    The micro-structural modifications produced in MgO single crystals exposed to medium-energy heavy ions (1.2-MeV Au) were investigated using Rutherford backscattering spectrometry in channeling geometry coupled to Monte-Carlo analyses, secondary ion mass spectrometry, X-ray diffraction and transmission electron microscopy. The damage accumulation and the elastic strain variation were interpreted in the framework of the multi-step damage accumulation (MSDA) model. Both build-ups follow a multi-step process similar to that recently observed for ion-irradiated yttria-stabilized zirconia (YSZ) single crystals. However, in MgO, an unexpectedly high disorder level occurs far beyond the theoretical damage distribution. These results strongly suggest that the migration of defects created in the near-surface layer is most likely at the origin of the broadening of the damage depth distribution in MgO.

  13. Damage processes in MgO irradiated with medium-energy heavy ions

    SciTech Connect

    Moll, Sandra; Zhang, Yanwen; Debelle, Aurelien; Thomé, Lionel; Crocombette, Jean-Paul; Zihua, Z.; Jagielski, Jacek; Weber, William J.

    2015-01-01

    In this research, the micro-structural modifications produced in MgO single crystals exposed to medium-energy heavy ions (1.2-MeV Au) were investigated using Rutherford backscattering spectrometry in channeling geometry coupled to Monte-Carlo analyses, secondary ion mass spectrometry, X-ray diffraction and transmission electron microscopy. The damage accumulation and the elastic strain variation were interpreted in the framework of the multi-step damage accumulation (MSDA) model. Both build-ups follow a multi-step process similar to that recently observed for ion-irradiated yttria-stabilized zirconia (YSZ) single crystals. However, in MgO, an unexpectedly high disorder level occurs far beyond the theoretical damage distribution. In conclusion, these results strongly suggest that the migration of defects created in the near-surface layer is most likely at the origin of the broadening of t he damage depth distribution in MgO.

  14. The use of ion flotation for detoxification of metal-contaminated waters and process effluents

    SciTech Connect

    Doyle, F.M.; Duyvesteyn, S.; Sreenivasarao, K.

    1995-12-31

    Toxic metals entering surface or ground water from sources such as metal finishing shop spills and abandoned mines can pose a significant threat to public health and the environment. Ion flotation and similar foam separation techniques show great promise for treating dilute, metal-contaminated solutions, and could also be used to treat effluents from many minerals and metallurgical processing operations prior to discharge. In ion flotation, an appropriate collector is added to the solution to form hydrophobic complexes with the metal ions. These metal-bearing species are then removed by flotation, usually with trace addition of a frother to stabilize the foam. In an effort to better understand the underlying scientific and engineering principles that determine the performance of ion flotation, the removal of Cu(II), Pb(II), Cd(II), Cr(III) and Cr(VI) has been studied using laboratory scale flotation columns in batch mode. The effects of the superficial air velocity, solution and froth height, nature of the collector, collector:metal-ion ratio, ionic strength and several frothers at low concentrations on the flotation kinetics are reported. Finally, results are presented on methods that might allow regeneration of collector and recovery of by-product metal from the foam product.

  15. Focused ion beam fabrication of spintronic nanostructures: an optimization of the milling process.

    PubMed

    Urbánek, M; Uhlír, V; Bábor, P; Kolíbalová, E; Hrncír, T; Spousta, J; Sikola, T

    2010-04-09

    Focused ion beam (FIB) milling has been used to fabricate magnetic nanostructures (wires, squares, discs) from single magnetic layers (Co, permalloy) and spin-valve (permalloy/Cu/Co) multilayers (thicknesses 5-50 nm) prepared by ion beam sputtering deposition. Milled surfaces of metallic thin films typically exhibit residual roughness, which is also transferred onto the edges of the milled patterns. This can lead to domain wall pinning and influence the magnetization behaviour of the nanostructures. We have investigated the milling process and the influence of the FIB parameters (incidence angle, dwell time, overlap and ion beam current) on the roughness of the milled surface. It has been found that the main reasons for increased roughness are different sputter yields for various crystallographic orientations of the grains in polycrystalline magnetic thin films. We have found that the oblique ion beam angle, long dwell time and overlap < 1 are favourable parameters for suppression of this intrinsic roughness. Finally, we have shown how to determine the ion dose necessary to mill through the whole thin film up to the silicon substrate from scanning electron microscopy (SEM) images only.

  16. Experimental progress with novel surface electrode ion trap structures for quantum information processing

    NASA Astrophysics Data System (ADS)

    Clark, Craig; Blain, Matthew; Benito, Francisco; Chou, Chin-Wen; Descour, Mike; Ellis, Rob; Haltli, Ray; Heller, Edwin; Kemme, Shanalyn; Sterk, Jon; Tabakov, Boyan; Tigges, Chris; Maunz, Peter; Stick, Daniel

    2013-05-01

    Segmented surface electrode ion traps are one of the most mature platforms among candidates for scalable quantum information processing. In this poster, an overview of current results from four specific projects will be presented. Two projects involve increased light collection from trapped ion for state detection and/or remote entangling of distant ions. The first involves cavity integration into a linear surface trap, and the second, involves integration of diffractive optical elements into a linear surface trap for increased light collection. Another project involves a trap with a ring geometry which could be used to trap long chains of equally spaced ions. Finally, we report on initial testing of a trap structure with vastly improved in-plane optical access. In this structure in-plane beams can be focused to less than 8 microns while keeping a distance of at least 5 beam radii to the trap structure. Along with these projects other relevant progress from Sandia National Laboratory's ion trap group will be presented. This work was supported by Sandia's Laboratory Directed Research and Development (LDRD) and the Intelligence Advanced Research Projects Activity (IARPA). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  17. Fundamental aspects on ion-beam surface modification: defect production and migration processes

    SciTech Connect

    Rehn, L.E.; Averback, R.S.; Okamoto, P.R.

    1984-09-01

    Ion-beam modification of metals is generating increasing scientific interest not only because it has exciting technological potential, but also because it has raised fundamental questions concerning radiation-induced diffusion processes. In addition to the implanted species, several defect production and migration mechanisms contribute to changes in the near-surface composition of an alloy during ion bombardment, e.g., atoms exchange positions via displacements and replacement sequences; preferential sputtering effects arise; radiation-enhanced diffusion and radiation-induced segregation occur. The latter two defect migration mechanisms are of particular significance since they can alter the composition to depths which are much greater than the implanted ion range. By altering various parameters such as irradiation temperature, ion mass, energy, and current density, and initial alloying distributions, a rich variety of near-surface composition profiles can be created. We have utilized changes in ion mass and energy, and irradiation temperature to distinguish defect production from defect migration effects. Experimental results are presented which provide a guide to the relative efficiencies of different mechanisms under various irradiation conditions. 46 references.

  18. Turbulent thermalization process in high-energy heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Berges, Jürgen; Schenke, Björn; Schlichting, Sören; Venugopalan, Raju

    2014-11-01

    We discuss the onset of the thermalization process in high-energy heavy-ion collisions from a weak-coupling perspective, using classical-statistical real-time lattice simulations as a first principles tool to study the pre-equilibrium dynamics. Most remarkably, we find that the thermalization process is governed by a universal attractor, where the space-time evolution of the plasma becomes independent of the initial conditions and exhibits the self-similar dynamics characteristic of wave turbulence [1]. We discuss the consequences of our weak-coupling results for the thermalization process in heavy-ion experiments and briefly comment on the use of weak-coupling techniques at larger values of the coupling.

  19. Electron-impact detachment from B-

    NASA Astrophysics Data System (ADS)

    Andersen, L. H.; Jensen, M. J.; Pedersen, H. B.; Vejby-Christensen, L.; Djurić, N.

    1998-10-01

    Cross sections for electron-impact single and double detachment from B- have been measured from 0 to 200 eV. The single-detachment cross section peaks at 4-5 eV with a cross-section maximum of about 10-14 cm2. A (2p3) 4S state has recently been predicted to give rise to a resonance state in the H2- dianion [T. Sommerfeld et al., Phys. Rev. A 55 1903 (1997)]. We observe no resonances in the detachment cross section of B- and hence no sign of an equivalent shortlived B2-(2p3) state. The ratio of the double- to single-detachment cross section reaches a constant value of 3% at energies above 50 eV. A simple model relates this number to a shake-off probability of about 90%. The ratio between double and single ionization of neutral atomic targets at high energy is also discussed, and the model relates this ratio to the shake-off probability in the sudden approximation.

  20. [Retinal detachment in various myopic refractions].

    PubMed

    Alimanović-Halilović, Emina

    2009-01-01

    The basic aim of this study was to find the group of "critical" myopic refraction with the highest occurrence of retinal detachment. In the study, 180 myopic eyes were analyzed. Upon the targeted ophthalmological anamnesis, definition of the objective refraction, and indirect binocular ophthalmoscopy, we analyzed the distribution of retinal detachment and the area affected in relation to refraction. All the eyes were divided into groups according to the refraction height. Average age of our patients ranged from 48.43 to 51.60 years with SD from 13.88 to 18.45. We did not find a statistically significant difference for a certain age. The study covered 102 (56.6%) male and 78 (43.3%) female patients. The highest occurrence of retinal detachment was found in Refraction Group from 3.5 to 7.49 dsph, total 21 (11.6%). The retinal detachments usually affected 2/4 or 3/4 of the eye fundus surface respectively.

  1. [Retinal detachment with retinoschisis--case report].

    PubMed

    Cristescu, R; Muşat, O; Toma, Oana; Coma, Corina; Gabej, Ioana; Burcea, M

    2013-01-01

    We present the case of a 43 year old patient diagnosed with rhegmatogenous retinal detachment and retinoschizis, a rare case of disease association. Surgery is recommended and we practice 23 gauge vitrectomy, laser retinopexy, criopexy in the periphery and internal heavy oil tamponade. Postoperatory evolution was favorable.

  2. Enzyme-free cell detachment mediated by resonance vibration with temperature modulation.

    PubMed

    Kurashina, Yuta; Hirano, Makoto; Imashiro, Chikahiro; Totani, Kiichiro; Komotori, Jun; Takemura, Kenjiro

    2017-10-01

    Cell detachment is an essential process in adherent cell culture. However, trypsinization, which is the most popular detachment technique used in culture, damages cellular membranes. Reducing cellular membrane damage during detachment should improve the quality of cell culture. In this article, we propose an enzyme-free cell detachment method based on resonance vibration with temperature modulation. We developed a culture device that can excite a resonance vibration and control temperature. We then evaluated the cell detachment ratio and the growth response, observed the morphology, and analyzed the cellular protein of the collected cells-mouse myoblast cell line (C2C12). With the temperature of 10°C and the maximum vibration amplitude of 2 μm, 77.9% of cells in number were successfully detached compared with traditional trypsinization. The 72-h proliferation ratio of the reseeded cells was similar to that with trypsinization, whereas the proliferation ratio of proposed method was 12.6% greater than that of trypsinization after freezing and thawing. Moreover, the cells can be collected relatively intact and both intracellular and cell surface proteins in the proposed method were less damaged than in trypsinization. These results show that this method has definite advantages over trypsinization, which indicates that it could be applied to subcultures of cells that are more susceptible to trypsin damage for mass culture of sustainable clinical use. Biotechnol. Bioeng. 2017;114: 2279-2288. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Analytical method for determining rill detachment rate of purple soil as compared with that of loess soil

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-yan; Huang, Yu-han; Zhao, Yu; Mo, Bin; Mi, Hong-xing; Huang, Chi-hua

    2017-06-01

    Rill detachment is an important process in rill erosion. The rill detachment rate is the fundamental basis for determination of the parameters of a rill erosion model. In this paper, an analytical method was proposed to estimate the rill detachment rate. The method is based on the exact analytical solution of rill erosion to the differential equation of rill detachment. The rill sediment concentration distribution as a function of rill length was identified through laboratory experiments under different slope gradients and flow rates. The sediment concentration processes from experiments on loess and purple rills were considered to estimate the rill detachment rates of both soils analytically. They were respectively used as a function of rill length and sediment concentration. The analytical detachment rates were compared with the numerically determined values to verify the analytical methods. The rill detachment rates of the two soils under different flow rates and slope gradients estimated by the analytical method were further compared on the basis of detachment-sediment function and detachment-rill length function. Results indicated that the analytically estimated values were very close to the numerically estimated values. Numerical and analytical methods were equally useful for rill detachment rate estimation. Therefore, the analytical method was verified to be rational and applicable for the rapid determination of the rill detachment rates based on either sediment concentration or rill length. The analytical detachment values of purple and loess soils suggested that the detachment rates of loess soil were significantly and considerably higher than those of purple soil. The erosion potentials of loess soil were also significant higher than those of purple soil. The differences in the erosion of the two soils decreased as the slope gradient and flow rate increased. These observations implied that the degree of loess soil erosion was greater than that of purple

  4. Change of pH and Iron Ion Concentration During Photodegradation of TCE with Ferrioxalate/UVvis Process

    NASA Astrophysics Data System (ADS)

    Hareyama, Wataru; Suto, Koichi; Inoue, Chihiro; Chida, Tadashi; Nakazawa, Hiroshi

    2006-05-01

    Recently, some studies show various organic compounds such as pesticides and dyes degraded with the irradiation of ultraviolet light and visible light in the presence of oxalic acid and ferric ion (ferrioxalate/UVvis process). The process has much advance than other technologies because it can utilize the wavelength of 300˜450nm and also under the condition of neutral pH. Chlorinated organic compounds such as trichloroethene (TCE), which have caused ground water pollution on a lot of sites, have never been applied by photodegradation with this process. In this study, we showed the degradation of TCE in the presence of oxalic acid and iron ion and the change of pH, ferric and ferrous ion concentration during the photodegradation of TCE with ferrioxalate/UV-vis process. TCE was degraded in the presence of oxalic acid and iron ion. In the reactions, the equilibrium of oxalate ion and iron ion is important since it determines the amount of ferrioxalate complex which absorbs light and induces the reactions of the degradation of TCE. Thus, the pH value and iron ion concentration are the important factors which determine the amount of ferrioxalate complex. The pH is nearly constant during the photodegradation of TCE. The ferrous ion concentration was decreased as soon as beginning photodegradation of TCE, and then the ferrous ion concentration and ferric ion concentration became constant.

  5. Making waves: Kinetic processes controlling surface evolution during low energy ion sputtering

    NASA Astrophysics Data System (ADS)

    Chan, Wai Lun; Chason, Eric

    2007-06-01

    When collimated beams of low energy ions are used to bombard materials, the surface often develops a periodic pattern or "ripple" structure. Different types of patterns are observed to develop under different conditions, with characteristic features that depend on the substrate material, the ion beam parameters, and the processing conditions. Because the patterns develop spontaneously, without applying any external mask or template, their formation is the expression of a dynamic balance among fundamental surface kinetic processes, e.g., erosion of material from the surface, ion-induced defect creation, and defect-mediated evolution of the surface morphology. In recent years, a comprehensive picture of the different kinetic mechanisms that control the different types of patterns that form has begun to emerge. In this article, we provide a review of different mechanisms that have been proposed and how they fit together in terms of the kinetic regimes in which they dominate. These are grouped into regions of behavior dominated by the directionality of the ion beam, the crystallinity of the surface, the barriers to surface roughening, and nonlinear effects. In sections devoted to each type of behavior, we relate experimental observations of patterning in these regimes to predictions of continuum models and to computer simulations. A comparison between theory and experiment is used to highlight strengths and weaknesses in our understanding. We also discuss the patterning behavior that falls outside the scope of the current understanding and opportunities for advancement.

  6. Ponderomotive processes as proxies for breaking of ion acoustic solitary waves

    NASA Astrophysics Data System (ADS)

    Kakad, Amar; Kakad, Bharati

    2016-12-01

    Wave breaking is a ubiquitous nonlinear phenomenon in plasma that is followed by sudden drop of wave amplitude after a wave steepening. We perform fluid simulation of the ion acoustic solitary waves (IASWs) to investigate the start time of the wave steepening and breaking process. This simulation demonstrates that a long wavelength perturbation in the electron and ion equilibrium densities evolves into two long wavelength IASWs. These IASWs steepens and breaks into short wavelength solitary structures, which become stable ion acoustic solitons at later time. From the detailed analysis of simulation output, we accomplish the criteria for steepening and breaking of the IASWs based on the (a) acceleration of IASWs (b) balance between maximum potential energy and the maximum electron kinetic energy. Furthermore, we examined the ponderomotive potential and the ponderomotive frequency of the electrons and ions during the process of the generation, steepening and breaking of these IASWs. It is observed that the maximum ponderomotive potential of both electrons and ions enhances during the steepening and attains the maximum close to the breaking of the IASWs. The simulation shows that the electron (ion) average ponderomotive frequency is considerably higher than the electron plasma frequency in the initial phase of generation of IASWs, which rapidly oscillates and approaches to frequencies much smaller than electron (ion) plasma frequency. These ponderomotive frequencies remain unchanged until the start of steepening of the IASWs; however, both frequencies are found to increase during the steepening and breaking of these IASWs. Based on this information, we propose that the ponderomotive potential and ponderomotive frequencies of electrons and ions can be used as proxies to determine the steepening and breaking time of the IASWs. We find that the onset time of the wave breaking varies inversely with the thermal velocity of the electrons and the amplitude of the initial

  7. Risk factors of rhegmatogenous retinal detachment associated with choroidal detachment in Chinese patients

    PubMed Central

    Gu, Yong-Hao; Ke, Gen-Jie; Wang, Lin; Gu, Qi-Hong; Zhou, En-Liang; Pan, Hong-Biao; Wang, Shi-Ying

    2016-01-01

    AIM To comprehensively analyze the risk factors of rhegmatogenous retinal detachment (RRD) associated with choroidal detachment (CD). METHODS A total of 265 eyes of 265 consecutive cases of RRD were retrospectively analyzed. All patients had systemic and ophthalmologic examination. CD was diagnosed by indirect ophthalmoscopy, B-scan ultrasonography, and ultrasound biomicroscope (UBM). Each parameter was compared between patients of RRD and rhegmatogenous retinal detachment associated with choroidal detachment (RRDCD). Logistic regression analysis was used to determine the independent risk factors of CD. RESULTS There were 52 eyes (19.62%) with CD. Pseudophakia was more commonly seen in RRDCD (21.15% vs 6.10%, P=0.002). Intraocular pressure (IOP) was lower (8.60±3.62 vs 12.96±3.55, P<0.001), best-corrected visual acuity was worse [3.00 (2.00 to 3.00) vs 1.92 (1.22 to 3.00), P=0.001], and refractive error was more myopic [-4 (-9 to -2) vs -2 (-6 to 0), P=0.007] in RRDCD. Eyes with RRDCD had larger extent of retinal detachment (P=0.007). In RRDCD, 34.62% of eyes presented with multiple holes (P=0.044) and 25.00% with macular holes (P=0.012), compared with 20.66% and 14.08% in RRD. High myopia (P=0.039), low IOP (P=0.017), and larger extent of retinal detachment (P<0.001) were significant and independent risk factors for developing CD. CONCLUSION For CD in RRD, related factors include BCVA, IOP, lens status, refractive error, extent of retinal detachment, number of holes, and macular hole. Larger extent of retinal detachment, high myopia, and low IOP are significant and independent risk factors. PMID:27500106

  8. Experimental determination of plasma detachment from the diverging magnetic nozzle of the VASIMR VX-200 Electric Thruster

    NASA Astrophysics Data System (ADS)

    Olsen, Christopher; Squire, Jared; Longmier, Benjamin; Ballenger, Maxwell; Cassady, Leonard; Carter, Mark; Ilin, Andrew; Cloutier, Paul; Bering, Edgar; Giambusso, Matthew; Ad Astra Rocket Company Team; Rice University Collaboration; University of Houston Collaboration

    2011-10-01

    Theories of magnetized plasma detachment in an expanding magnetic field have been lacking detailed experimental evidence. Recent experiments using a 200 kW class electric rocket (VX-200), run at 100 kW using argon and a peak magnetic field of 2 T, produced ion energies greater than 100 eV with a flux of 2x1022 ions/s in a 150 m3 vacuum facility. Ion-neutral charge exchange effects were reduced and the resultant data show evidence of plasma detachment in a diverging magnetic field on a scale length of 2 m. The detachment is confirmed using multiple plasma diagnostics and magnetic nozzle topologies. Spatial maps of the data are compared to simulations from a particle detachment model, ParTraj, as well as MHD detachment theory. ParTraj, when compared to experiment, is shown to be more consistent in describing the data. Unless the MHD models are modified to incorporation two-fluid effects, single fluid MHD theory is inconsistent with the observations.

  9. Process for ion-assisted laser deposition of biaxially textured layer on substrate

    DOEpatents

    Russo, R.E.; Reade, R.P.; Garrison, S.M.; Berdahl, P.

    1995-07-11

    A process for depositing a biaxially aligned intermediate layer over a non-single crystal substrate is disclosed which permits the subsequent deposition thereon of a biaxially oriented superconducting film. The process comprises depositing on a substrate by laser ablation a material capable of being biaxially oriented and also capable of inhibiting the migration of substrate materials through the intermediate layer into such a superconducting film, while simultaneously bombarding the substrate with an ion beam. In a preferred embodiment, the deposition is carried out in the same chamber used to subsequently deposit a superconducting film over the intermediate layer. In a further aspect of the invention, the deposition of the superconducting layer over the biaxially oriented intermediate layer is also carried out by laser ablation with optional additional bombardment of the coated substrate with an ion beam during the deposition of the superconducting film. 8 figs.

  10. Process for ion-assisted laser deposition of biaxially textured layer on substrate

    DOEpatents

    Russo, Richard E.; Reade, Ronald P.; Garrison, Stephen M.; Berdahl, Paul

    1995-01-01

    A process for depositing a biaxially aligned intermediate layer over a non-single crystal substrate is disclosed which permits the subsequent deposition thereon of a biaxially oriented superconducting film. The process comprises depositing on a substrate by laser ablation a material capable of being biaxially oriented and also capable of inhibiting the migration of substrate materials through the intermediate layer into such a superconducting film, while simultaneously bombarding the substrate with an ion beam. In a preferred embodiment, the deposition is carried out in the same chamber used to subsequently deposit a superconducting film over the intermediate layer. In a further aspect of the invention, the deposition of the superconducting layer over the biaxially oriented intermediate layer is also carried out by laser ablation with optional additional bombardment of the coated substrate with an ion beam during the deposition of the superconducting film.

  11. Adsorption Processes of Lead Ions on the Mixture Surface of Bentonite and Bottom Sediments.

    PubMed

    Hegedűsová, Alžbeta; Hegedűs, Ondrej; Tóth, Tomáš; Vollmannová, Alena; Andrejiová, Alena; Šlosár, Miroslav; Mezeyová, Ivana; Pernyeszi, Tímea

    2016-12-01

    The adsorption of contaminants plays an important role in the process of their elimination from a polluted environment. This work describes the issue of loading environment with lead Pb(II) and the resulting negative impact it has on plants and living organisms. It also focuses on bentonite as a natural adsorbent and on the adsorption process of Pb(II) ions on the mixture of bentonite and bottom sediment from the water reservoir in Kolíňany (SR). The equilibrium and kinetic experimental data were evaluated using Langmuir isotherm kinetic pseudo-first and pseudo-second-order rate equations the intraparticle and surface diffusion models. Langmuir isotherm model was successfully used to characterize the lead ions adsorption equilibrium on the mixture of bentonite and bottom sediment. The pseudo second-order model, the intraparticle and surface (film) diffusion models could be simultaneously fitted the experimental kinetic data.

  12. [Determination of sodium chlorite in processed herring roe by ion chromatography with a conductivity detector].

    PubMed

    Kawasaki, Yoko; Kubota, Hiroki; Yomota, Chikako; Tanamoto, Kenichi

    2005-08-01

    An analytical method for residual sodium chlorite in several kinds of processed herring roe treated with sodium chlorite was studied. Sodium chlorite was extracted with 9 mmol/L sodium carbonate. After centrifugation, the supernatant was filtered through a 0.2 microm nylon filter. The filtrate was deproteinized by ultrafiltration and chloride ion was removed with an On-Guard Ag cartridge column. The eluate was subjected to conductivity detector-ion chromatography. Recoveries of sodium chlorite from herring roe spiked at the level of 5 mg/kg were 88 +/- 3.7% (n = 5, CV 4.2%). The method had a quantitation limit of 5 mg/kg for processed herring roes.

  13. Amphitrite: A program for processing travelling wave ion mobility mass spectrometry data.

    PubMed

    Sivalingam, Ganesh N; Yan, Jun; Sahota, Harpal; Thalassinos, Konstantinos

    2013-07-01

    Since the introduction of travelling wave (T-Wave)-based ion mobility in 2007 a large number of research laboratories have embraced the technique, particularly those working in the field of structural biology. The development of software to process the data generated from this technique, however, has been limited. We present a novel software package that enables the processing of T-Wave ion mobility data. The program can deconvolute components in a mass spectrum and uses this information to extract corresponding arrival time distributions (ATDs) with minimal user intervention. It can also be used to automatically create a collision cross section (CCS) calibration and apply this to subsequent files of interest. A number of applications of the software, and how it enhances the information content extracted from the raw data, are illustrated using model proteins.

  14. ADVANCING THE ION BEAM THIN FILM PLANARIZATION PROCESS FOR THE SMOOTHING OF SUBSTRATE PARTICLES

    SciTech Connect

    Mirkarimi, P B; Spiller, E; Baker, S L; Robinson, J C; Stearns, D G; Liddle, J A; Salmassi, F; Liang, T; Stivers, A R

    2004-10-19

    For a number of technologies small substrate contaminants are undesirable, and for one technology in particular, extreme ultraviolet lithography (EUVL), they can be a very serious issue. We have demonstrated that the Ion Beam Thin Film Planarization Process, a coating process designed to planarize substrate asperities, can be extended to smooth {approx}70 nm and {approx}80 nm diameter particles on EUVL reticle substrates to a height of {approx}0.5 nm, which will render them noncritical in an EUVL printing process. We demonstrate this smoothing process using controlled nanoscale substrate particles and lines fabricated with an e-beam lithography process. The above smoothing process was also modified to yield an excellent reflectance/wavelength uniformity and a good EUV reflectivity for the multilayer, which is required for EUVL reticles. Cross-sectional TEM on a smoothed substrate line defect shows excellent agreement with results obtained from our multilayer growth model.

  15. Effect of preoperative posture and binocular occlusion on retinal detachment.

    PubMed Central

    Lean, J S; Mahmood, M; Manna, R; Chignell, A H

    1980-01-01

    In an unselected series of retinal detachments a 24-hour period of binocular occlusion and posture with a retinal hole dependent produces some resolution of subretinal fluid in 13% of cases. If only patients with acute, freely mobile detachments and retinal holes above the horizontal meridian were selected the proportion of detachments showing some resolution rose to 30%. In 8% of cases a paradoxical response occurred, the detachment increasing in depth or extending to involve an additional area of retina. PMID:7362818

  16. Quantum Control, Quantum Information Processing, and Quantum-Limited Metrology with Trapped Ions

    NASA Astrophysics Data System (ADS)

    Wineland, D. J.; Leibfried, D.; Barrett, M. D.; Ben-Kish, A.; Bergquist, J. C.; Blakestad, R. B.; Bollinger, J. J.; Britton, J.; Chiaverini, J.; Demarco, B.; Hume, D.; Itano, W. M.; Jensen, M.; Jost, J. D.; Knill, E.; Koelemeij, J.; Langer, C.; Oskay, W.; Ozeri, R.; Reichle, R.; Rosenband, T.; Schaetz, T.; Schmidt, P. O.; Seidelin, S.

    2005-12-01

    We briefly discuss recent experiments on quantum information processing using trapped ions at NIST. A central theme of this work has been to increase our capabilities in terms of quantum computing protocols, but we have also applied the same concepts to improved metrology, particularly in the area of frequency standards and atomic clocks. Such work may eventually shed light on more fundamental issues, such as the quantum measurement problem.

  17. Process for improving mechanical properties of epoxy resins by addition of cobalt ions

    NASA Technical Reports Server (NTRS)

    Stoakley, D. M.; St.clair, A. K. (Inventor)

    1984-01-01

    A resin product useful as an adhesive, composite or casting resin is described as well as the process used in its preparation to improve its flexural strength mechanical property characteristics. Improved flexural strength is attained with little or no change in density, thermal stability or moisture resistance by chemically incorporating 1.2% to 10.6% by weight Co(3) ions in an epoxidized resin system.

  18. Anaerobic-ion exchange (AN-IX) process for local-scale nitrogen recovery from wastewater.

    PubMed

    Smith, Daniel P; Smith, Nathaniel T

    2015-11-01

    An anaerobic-ion exchange (AN-IX) process was developed for point-of-origin recovery of nitrogen from household wastewater. The process features upflow solids-blanket anaerobic treatment (ammonification) followed by ammonium ion exchange onto natural zeolite. The AN-IX system is configured as a series of linked upflow chambers that operate passively without energy input, and is amenable to intermittent and seasonal operation. A 57L prototype was operated for over 1.8 years treating actual wastewater under field conditions. Total nitrogen removal exceeded 96% through the first 160 days of operation and effluent ammonium nitrogen remained below detection for 300 days. Ion exchange chambers exhibited sequential NH4(+)-N breakthrough over extended operation and complete media exhaustion was approached at Day 355. The ammonium capacity of zeolite was estimated as 13.5mg NH4(+)-N per gram dry weight. AN-IX is a resilient and cost effective process for local-scale nitrogen recovery and reuse, suitable for small scale and larger systems.

  19. Numerical simulations used for a validity check on the laser induced photo-detachment diagnostic method in electronegative plasmas

    SciTech Connect

    Oudini, N.; Taccogna, F.; Aanesland, A.

    2014-06-15

    Laser photo-detachment is used as a method to measure or determine the negative ion density and temperature in electronegative plasmas. In essence, the method consists of producing an electropositive channel (negative ion free region) via pulsed laser photo-detachment within an electronegative plasma bulk. Electrostatic probes placed in this channel measure the change in the electron density. A second pulse might be used to track the negative ion recovery. From this, the negative ion density and temperature can be determined. We study the formation and relaxation of the electropositive channel via a two-dimensional Particle-In-Cell/Mote Carlo collision model. The simulation is mainly carried out in a Hydrogen plasma with an electronegativity of α = 1, with a parametric study for α up to 20. The temporal and spatial evolution of the plasma potential and the electron densities shows the formation of a double layer (DL) confining the photo-detached electrons within the electropositive channel. This DL evolves into two fronts that move in the opposite directions inside and outside of the laser spot region. As a consequence, within the laser spot region, the background and photo-detached electron energy distribution function relaxes/thermalizes via collisionless effects such as Fermi acceleration and Landau damping. Moreover, the simulations show that collisional effects and the DL electric field strength might play a non-negligible role in the negative ion recovery within the laser spot region, leading to a two-temperature negative ion distribution. The latter result might have important effects in the determination of the negative ion density and temperature from laser photo detachment diagnostic.

  20. Dust charging processes with a Cairns-Tsallis distribution function with negative ions

    SciTech Connect

    Abid, A. A.; Khan, M. Z.; Yap, S. L.; Terças, H.; Mahmood, S.

    2016-01-15

    Dust grain charging processes are presented in a non-Maxwellian dusty plasma following the Cairns-Tsallis (q, α)–distribution, whose constituents are the electrons, as well as the positive/negative ions and negatively charged dust grains. For this purpose, we have solved the current balance equation for a negatively charged dust grain to achieve an equilibrium state value (viz., q{sub d} = constant) in the presence of Cairns-Tsallis (q, α)–distribution. In fact, the current balance equation becomes modified due to the Boltzmannian/streaming distributed negative ions. It is numerically found that the relevant plasma parameters, such as the spectral indexes q and α, the positive ion-to-electron temperature ratio, and the negative ion streaming speed (U{sub 0}) significantly affect the dust grain surface potential. It is also shown that in the limit q → 1 the Cairns-Tsallis reduces to the Cairns distribution; for α = 0 the Cairns-Tsallis distribution reduces to pure Tsallis distribution and the latter reduces to Maxwellian distribution for q → 1 and α = 0.

  1. Dust charging processes with a Cairns-Tsallis distribution function with negative ions

    NASA Astrophysics Data System (ADS)

    Abid, A. A.; Khan, M. Z.; Yap, S. L.; Terças, H.; Mahmood, S.

    2016-01-01

    Dust grain charging processes are presented in a non-Maxwellian dusty plasma following the Cairns-Tsallis (q, α)-distribution, whose constituents are the electrons, as well as the positive/negative ions and negatively charged dust grains. For this purpose, we have solved the current balance equation for a negatively charged dust grain to achieve an equilibrium state value (viz., qd = constant) in the presence of Cairns-Tsallis (q, α)-distribution. In fact, the current balance equation becomes modified due to the Boltzmannian/streaming distributed negative ions. It is numerically found that the relevant plasma parameters, such as the spectral indexes q and α, the positive ion-to-electron temperature ratio, and the negative ion streaming speed (U0) significantly affect the dust grain surface potential. It is also shown that in the limit q → 1 the Cairns-Tsallis reduces to the Cairns distribution; for α = 0 the Cairns-Tsallis distribution reduces to pure Tsallis distribution and the latter reduces to Maxwellian distribution for q → 1 and α = 0.

  2. Track damage and erosion of insulators by ion-induced electronic processes

    NASA Technical Reports Server (NTRS)

    Tombrello, T. A.

    1984-01-01

    Track damage and the associated ejection of atoms and molecules from insulators, which occur as a result of ion-induced electronic excitation, are of interest both in their own right and because of the mechanisms through which the energy in the excited electrons is transformed into atomic motion. In this paper an overview is given of the phenomena that are observed. We show that there is a remarkable similarity between the damage profile along the ion's track in the solid and the yield of ejected atoms at the energy that corresponds to each point on the track. It is also seen that the density of extended defects (or, correspondingly, the ejected particle yield) appears to have a 'universal' form that is weakly dependent on the type of material. In the model presented this is a consequence of the inner-shell ionization of light elements in the solid by the incident ion; the resulting Auger decay produces an intense ionization spike that locally triggers the track formation/erosion process. This model allows the estimation of erosion yields/damage profiles for different ions and materials.

  3. Sulfite oxidation catalyzed by cobalt ions in flue gas desulfurization processes.

    PubMed

    Karatza, Despina; Prisciandaro, Marina; Lancia, Amedeo; Musmarra, Dino

    2010-06-01

    This paper presents an experimental study of calcium bisulfite oxidation, a key step in the wet limestone-gypsum flue gas desulfurization (FGD) process, in the presence of catalysts (e.g., cobalt ions and a mixture of ferrous and cobalt ions). A fundamental approach is followed, by reproducing a simplified synthetic FGD liquor in which both catalyst ions, alone or mixed together, are present. A laboratory-scale apparatus is used, in which sulfurous solution is contacted with a gas phase at a fixed oxygen partial pressure (21.3 kPa) and at different temperature levels (25, 45, and 55 degrees C). The experimental results are analyzed using the theory of gas-liquid mass transfer with chemical reaction, showing that the slow reaction regime is explored and the transition from the kinetic to the diffusional subregime is identified. The experimental results are compared with those obtained in the presence of other catalytic species (manganese and ferrous ions), showing that cobalt is effective in catalyzing the oxidation of calcium bisulfite to sulfate, but to a minor extent with respect to iron and manganese.

  4. Extended ion exchange process for removal and recovery of technetium from soluble waste

    SciTech Connect

    Bibler, J.P.; Wallace, R.M.

    1984-05-22

    A well-established method of separation of /sup 99/Tc from soluble waste is sorption of pertechnetate ion, TcO/sub 4//sup -/, onto a strong base anion exchange resin such as Dowex 1x8. Pertechnetate ion can then be removed from the resin by elution with 4M HNO/sub 3/. An improved ion exchange method which encompasses removal and recovery of /sup 99/Tc from defense waste supernate has been demonstrated. The introduction of a second ion exchange step using a weak base resin allows for the reclamation and recycling of large volumes of nitric acid generated in the initial collection of TcO/sub 4//sup -/ on the strong base resin. Also, the total amount of waste NaNO/sub 3/ which is added to the system in the process of removing /sup 99/Tc from the supernate is significantly reduced from 8% to 1%. /sup 99/Tc can be recovered from solution by precipitation as Tc/sub 2/S/sub 7/ with sulfide or as TcO/sub 2/ following reduction with aluminum or zinc amalgam, affording the ultimate recovery of the pure metal.

  5. Mesospheric electron detachment and LORE recovery times

    NASA Astrophysics Data System (ADS)

    Gordillo-Vazquez, Francisco J.; Haldoupis, Christos; Luque, Alejandro

    2015-04-01

    We present new results concerning the recovery times (> 10 minutes) of LOng Recovery Early VLF events (LORE) in the upper mesosphere connected to electromagnetic pulses (EMP) of large (> 250 kA km) charge moment change (CMC) ± CG (cloud to ground) lightning capable of producing elves or elve-sprite pairs (in the case of +CG parent lightning) [1], [2]. We have modeled two possible scenarios considering first the relaxation of slightly perturbed ambient electron densities (ne0 + Δne) without an impulsive ionization source and another scenario where the ambient electron density is considerably enhanced due to an impulsive ionization source (the lightning EMP). The full non-equilibrium kinetic and 2D EMP modelling of the perturbed mesosphere in the 76 km - 92 km range during LORE occurring conditions indicates that the electron density relaxation time (defined as the time the perturbed electron density, Δne, takes to decay a factor 1/e of the way to the ambient electron density (ne0)) is critically controlled at each altitude by the relative importance of associative detachment (of O- by, respectively, O and CO and of O2- by O) with respect to electron loss mechanisms (mainly 3-body, 2-body attachment and electron-ion recombination at the highest altitudes). We found that the maximum electron density relaxation time (> 15000 s) occur between 80 km and 82 km while it decreases with increasing altitudes to 12000 s (at 85 km) and about 2000 s (at 92 km). However, LORES are presumably due to VLF scattering from electron density enhancements caused by lightning-induced EMPs in the uppermost D region ionosphere (85 - 92 km). Thus the observed VLF signal recoveries (LORE recovery times) should associate with the relaxation of the maximum enhanced electron densities produced by elves between 85 km and 92 km [3]. Finally, our results for the lowest altitudes considered (76 km and 77 km) are in good agreement with the recovery times (between 20 s and 120 s) of the typical

  6. Photo excitation and laser detachment of C60(-) anions in a storage ring.

    PubMed

    Støchkel, K; Andersen, J U

    2013-10-28

    We have studied the photo physics of C60(-) anions in the electrostatic storage ring ELISA with ions produced in a plasma source and cooled and bunched in a He filled ion trap. A previous study using delayed electron detachment as a signal of resonance-enhanced multiphoton electron detachment (REMPED) has been repeated both at room temperature and with the trap cooled to liquid nitrogen temperature. However, wavelength dependence of the overlap of the strongly focused laser beam with the ion beam introduces distortions of the absorption spectrum. We have therefore applied a new method, combining the IR light with a slightly delayed, powerful UV pulse (266 nm). After absorption of three UV photons, the ions decay by delayed (thermal) electron emission, and time spectra are recorded for varying wavelength. The fraction of ions heated by absorption of a single IR photon is then extracted from a principal component analysis of these spectra. In good agreement with the earlier REMPED experiment, an origin band for transitions between the two lowest electronic levels of the anion, with t1u and t1g symmetry, is observed at 9380 cm(-1), with strong sidebands from excitation of the two A(g) and eight H(g) vibrations. As before, a hot band is observed at about 9150 cm(-1) and assigned to a transition from an excited vibronic Jahn-Teller state. However, an earlier observed band at higher energy, interpreted as a transition from this excited state to an excited vibronic state in the t1g electronic level, is much weaker in the new measurements and could be an H(g) vibrational sideband. Also earlier studies of direct laser detachment from C60(-) in the storage ring ASTRID have been revisited, with ions cooled by liquid nitrogen in the ion trap. We confirm the previous measurement with a determination of the threshold for s-wave detachment at 2.664 ± 0.005 eV, slightly lower than a recent value of the electron binding, 2.683 ± 0.008 eV, obtained from the energy spectrum of

  7. Interference structure of above-threshold ionization versus above-threshold detachment

    NASA Astrophysics Data System (ADS)

    Korneev, Ph A.; Popruzhenko, S. V.; Goreslavski, S. P.; Becker, W.; Paulus, G. G.; Fetić, B.; Milošević, D. B.

    2012-05-01

    Laser-induced electron detachment or ionization of atoms and negative ions is considered. In the context of the saddle-point evaluation of the strong-field approximation (SFA), the velocity maps of the direct electrons (those that do not undergo rescattering) exhibit a characteristic structure due to the constructive and destructive interference of electrons liberated from their parent atoms/ions within certain windows of time. This structure is defined by the above-threshold ionization rings at fixed electron energy and by two sets of curves in momentum space on which destructive interference occurs. The spectra obtained with the SFA are compared with those obtained by numerical solution of the time-dependent Schrödinger equation. For detachment, the agreement is excellent. For ionization, the effect of the Coulomb field is most pronounced for electrons emitted in a direction close to laser polarization, while for near-perpendicular emission the qualitative appearance of the spectrum is unaffected.

  8. Formation of Non-Monotonic Potential Structure in the Detached Plasma

    NASA Astrophysics Data System (ADS)

    Ishiguro, Seiji; Pianpanit, Theerasarn; Hasegawa, Hiroki

    2016-10-01

    Plasma detachment has been investigated by means of PIC simulation which includes plasma-neutral collision and Coulomb collision. In our previous study, we have shown that a strong gradient in temperature appears in front of the target plate in the case that high density and low temperature neutral gas is introduced. It is observed that a potential hill is created in the neutral gas region where ions lose energy due to the elastic and charge exchange collision and, as a result, the ion density increases. This potential structure traps the low energy electrons and may play a role in the development of plasma detachment state. This work is supported by NIFS Collaboration Research Programs NIFS14KNXN279 and NIFS14KNSS059 and the NIFS/NINS project of Formation of International Scientific Base and Network.

  9. Crystallization depth beneath an oceanic detachment fault (ODP Hole 923A, Mid-Atlantic Ridge)

    NASA Astrophysics Data System (ADS)

    Lissenberg, C. Johan; Rioux, Matthew; MacLeod, Christopher J.; Bowring, Samuel A.; Shimizu, Nobumichi

    2016-01-01

    Oceanic detachment faults are increasingly recognized as playing an integral role in the seafloor spreading process at slow and ultraslow spreading mid-ocean ridges, with significant consequences for the architecture of the oceanic lithosphere. Although melt supply is considered to play a critical control on the formation and evolution of oceanic detachments, much less well understood is how melts and faults interact and influence each other. Few direct constraints on the locus and depth of melt emplacement in the vicinity of detachments are available. Gabbros drilled in ODP Hole 923A near the intersection of the Mid-Atlantic Ridge and the Kane transform fault (23°N; the MARK area) represent magmas emplaced into the footwall of such a detachment fault and unroofed by it. We here present U-Pb zircon dates for these gabbros and associated diorite veins which, when combined with a tectonic reconstruction of the area, allow us to calculate the depths at which the melts crystallized. Th-corrected single zircon U-Pb dates from three samples range from 1.138 ± 0.062 to 1.213 ± 0.021 Ma. We find a crystallization depth of 6.4 +1.7/-1.3 km, and estimate that the melts parental to the gabbros were initially emplaced up to 1.5 km deeper, at <8 km below the seafloor. The tectonic reconstruction implies that the detachment fault responsible for the exposure of the sampled sequence likely crossed the ridge axis at depth, suggesting that melt emplacement into the footwall of oceanic detachment faults is an important process. The deep emplacement depth we find associated with "detachment mode" spreading at ˜1.2 Ma appears to be significantly greater than the depth of magma reservoirs during the current "magmatic mode" of spreading in the area, suggesting that the northern MARK segment preserves a recent switch between two temporally distinct modes of spreading with fundamentally different lithospheric architecture.

  10. Detached Growth of Germanium by Directional Solidification

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Volz, M.; Cobb, S.; Motakef, S.; Szofran, F. R.

    2004-01-01

    Detached crystal growth technique (dewetting) offers improvement in the quality of the grown crystals by preventing sticking to the walls of the crucible and thus reducing the possibility of parasitic nucleation and formation of lattice defects upon cooling. One of the factors relevant for the phenomena is the pressure differential across the meniscus at the crystal-melt interface. We investigated this effect experimentally. The growth took place in closed ampoules under the pressure of an inert gas (forming gas: 96% Ar + 4% H2). The pressure above the melt was adjustable and allowed for a control of the pressure difference between the top and bottom menisci. The crystals were characterized, particularly by taking profilometer measurements along the grown crystals surface. The effects of the experimental conditions on the detachment were compared with those predicted based on the theory of Duffar et al.

  11. Detached Growth of Germanium by Directional Solidification

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Volz, M.; Cobb, S.; Motakef, S.; Szofran, F. R.

    2004-01-01

    Detached crystal growth technique (dewetting) offers improvement in the quality of the grown crystals by preventing sticking to the walls of the crucible and thus reducing the possibility of parasitic nucleation and formation of lattice defects upon cooling. One of the factors relevant for the phenomena is the pressure differential across the meniscus at the crystal-melt interface. We investigated this effect experimentally. The growth took place in closed ampoules under the pressure of an inert gas (forming gas: 96% Ar + 4% H2). The pressure above the melt was adjustable and allowed for a control of the pressure difference between the top and bottom menisci. The crystals were characterized, particularly by taking profilometer measurements along the grown crystals surface. The effects of the experimental conditions on the detachment were compared with those predicted based on the theory of Duffar et al.

  12. Mechanism of bubble detachment from vibrating walls

    SciTech Connect

    Kim, Dongjun; Park, Jun Kwon Kang, Kwan Hyoung; Kang, In Seok

    2013-11-15

    We discovered a previously unobserved mechanism by which air bubbles detach from vibrating walls in glasses containing water. Chaotic oscillation and subsequent water jets appeared when a wall vibrated at greater than a critical level. Wave forms were developed at water-air interface of the bubble by the wall vibration, and water jets were formed when sufficiently grown wave-curvatures were collapsing. Droplets were pinched off from the tip of jets and fell to the surface of the glass. When the solid-air interface at the bubble-wall attachment point was completely covered with water, the bubble detached from the wall. The water jets were mainly generated by subharmonic waves and were generated most vigorously when the wall vibrated at the volume resonant frequency of the bubble. Bubbles of specific size can be removed by adjusting the frequency of the wall's vibration.

  13. Responsive systems for cell sheet detachment.

    PubMed

    Patel, Nikul G; Zhang, Ge

    2013-01-01

    Cell sheet engineering has been progressing rapidly during the past few years and has emerged as a novel approach for cell based therapy. Cell sheet harvest technology enables fabrication of viable, transplantable cell sheets for various tissue engineering applications. Currently, the majority of cell sheet studies use thermo-responsive systems for cell sheet detachment. However, other responsive systems began showing their potentials for cell sheet harvest. This review provides an overview of current techniques in creating cell sheets using different types of responsive systems including thermo-responsive, electro-responsive, photo-responsive, pH-responsive and magnetic systems. Their mechanism, approach, as well as applications for cell detachment have been introduced. Further development of these responsive systems will allow efficient cell sheet harvesting and patterning of cells to reconstruct complex tissue for broad clinical applications.

  14. Solar Ion Processing of Itokawa Grains: Constraints on Surface Exposure Times

    NASA Technical Reports Server (NTRS)

    Christoffersen, R.; Keller, L. P.

    2015-01-01

    Analytical TEM observations obtained to date reveal that a significant sub-population of grains returned from the surface of asteroid Itokawa have had their outer 30-100 nm processed by space weathering effects. Although the effects include some surface deposition of condensed impact vapor and isolated impact melt splashes, much of the width of the space weathered outer margins or "rims" on grains is derived from solar wind processing of the original host grain. Similar to what has long been reported for some lunar grains, the ion-processed rims on Itokawa grains exhibit varing degrees and depths of penetration of atomic-displacement ion damage, resulting in complete amorphization for some rims (particularly in plagioclase), or formation of highly defective but still crystalline structures in others (particularly in pyroxene and olivine). Possibly different from lunar grains, however, is the presence of isolated internal cavities or voids in Itokawa grain rims, which may be implantation "bubbles" due to accumulating implanted solar wind H and/or He. For a given mineral exposed at a particular set of long term solar wind conditions, the level of ion damage in a given grain rim, the depth of damage penetration represented by the rim width, and the formation or lack of formation of implantation bubbles can all be linked to the time spent by the grain in an uncovered state on the topmost, space-exposed, regolith surface. For the lunar case, we have previously shown that with reasonable assumptions about solar wind characteristics over time, a model can be developed to estimate this exposure time based on the width of amorphous rims on lunar grains. Here we report on an expansion of the model to cover exposure time information contained in the array of solar ion-induced features in Itokawa grains.

  15. Induction and processing of oxidative clustered DNA lesions in 56Fe-ion-irradiated human monocytes.

    PubMed

    Tsao, Doug; Kalogerinis, Peter; Tabrizi, Isla; Dingfelder, Michael; Stewart, Robert D; Georgakilas, Alexandros G

    2007-07-01

    Space and cosmic radiation is characterized by energetic heavy ions of high linear energy transfer (LET). Although both low- and high-LET radiations can create oxidative clustered DNA lesions and double-strand breaks (DSBs), the local complexity of oxidative clustered DNA lesions tends to increase with increasing LET. We irradiated 28SC human monocytes with doses from 0-10 Gy of (56)Fe ions (1.046 GeV/ nucleon, LET = 148 keV/microm) and determined the induction and processing of prompt DSBs and oxidative clustered DNA lesions using pulsed-field gel electrophoresis (PFGE) and Number Average Length Analysis (NALA). The (56)Fe ions produced decreased yields of DSBs (10.9 DSB Gy(-1) Gbp(-1)) and clusters (1 DSB: approximately 0.8 Fpg clusters: approximately 0.7 Endo III clusters: approximately 0.5 Endo IV clusters) compared to previous results with (137)Cs gamma rays. The difference in the relative biological effectiveness (RBE) of the measured and predicted DSB yields may be due to the formation of spatially correlated DSBs (regionally multiply damaged sites) which result in small DNA fragments that are difficult to detect with the PFGE assay. The processing data suggest enhanced difficulty compared with gamma rays in the processing of DSBs but not clusters. At the same time, apoptosis is increased compared to that seen with gamma rays. The enhanced levels of apoptosis observed after exposure to (56)Fe ions may be due to the elimination of cells carrying high levels of persistent DNA clusters that are removed only by cell death and/or "splitting" during DNA replication.

  16. Process for the production of hydrogen utilizing a photogalvanic effect of a polyacid ion

    SciTech Connect

    Ikawa, T.; Yamase, T.

    1982-08-24

    A process for the production of hydrogen is disclosed. This process utilizes a photogalvanic effect of a polyacid ion and comprises immersing an anode into an aqueous solution of an alkylammonium salt of polytungstic acid or polyvanadic acid as an anode electrolyte, immersing a cathode into an aqueous solution of an acid as a cathode electrolyte, isolating both said aqueous solutions to each other, electrically connecting both said electrodes to each other, and irradiating a light onto said anode electrolyte, whereby hydrogen is evoluted at said cathode.

  17. Ferric ion as a scavenging agent in a solvent extraction process

    DOEpatents

    Bruns, Lester E.; Martin, Earl C.

    1976-01-01

    Ferric ions are added into the aqueous feed of a plutonium scrap recovery process that employs a tributyl phosphate extractant. Radiolytic degradation products of tributyl phosphate such as dibutyl phosphate form a solid precipitate with iron and are removed from the extraction stages via the waste stream. Consequently, the solvent extraction characteristics are improved, particularly in respect to minimizing the formation of nonstrippable plutonium complexes in the stripping stages. The method is expected to be also applicable to the partitioning of plutonium and uranium in a scrap recovery process.

  18. Concentration Polarisation in the Electrodialysis Process and the Polarisation Characteristics of Ion-selective Membranes

    NASA Astrophysics Data System (ADS)

    Balavadze, Elyusbar M.; Bobreshova, O. V.; Kulintsov, P. I.

    1988-06-01

    Complications in the electrodialysis process, due to the occurrence of concentration polarisation, are analysed. It is shown that most present-day methods for measuring the electrochemical characteristics of ion-selective membranes are not suitable for monitoring the behaviour of these membranes over a wide range of polarising current densities. An analysis of the polarisation characteristics of electromembrane systems shows the advantages of a system with a rotating membrane disc. It is shown that in the polarisation process there is a significant deterioration of the electrochemical properties of heterogeneous membranes whereas the properties of homogeneous perfluorinated sulpho-cation-exchange membranes remain almost unchanged. The bibliography includes 43 references.

  19. Tonic Shock Induces Detachment of Giardia lamblia

    PubMed Central

    Hansen, Wendy R.; Fletcher, Daniel A.

    2008-01-01

    Background The parasite Giardia lamblia must remain attached to the host small intestine in order to proliferate and subsequently cause disease. However, little is known about the factors that may cause detachment in vivo, such as changes in the aqueous environment. Osmolality within the proximal small intestine can vary by nearly an order of magnitude between host fed and fasted states, while pH can vary by several orders of magnitude. Giardia cells are known to regulate their volume when exposed to changes in osmolality, but the short-timescale effects of osmolality and pH on parasite attachment are not known. Methodology and Principal Findings We used a closed flow chamber assay to test the effects of rapid changes in media osmolality, tonicity, and pH on Giardia attachment to both glass and C2Bbe-1 intestinal cell monolayer surfaces. We found that Giardia detach from both surfaces in a tonicity-dependent manner, where tonicity is the effective osmolality experienced by the cell. Detachment occurs with a characteristic time constant of 25 seconds (SD = 10 sec, n = 17) in both hypo- and hypertonic media but is otherwise insensitive to physiologically relevant changes in media composition and pH. Interestingly, cells that remain attached are able to adapt to moderate changes in tonicity. By exposing cells to a timed pattern of tonicity variations and adjustment periods, we found that it is possible to maximize the tonicity change experienced by the cells, overcoming the adaptive response and resulting in extensive detachment. Conclusions and Significance These results, conducted with human-infecting Giardia on human intestinal epithelial monolayers, highlight the ability of Giardia to adapt to the changing intestinal environment and suggest new possibilities for treatment of giardiasis by manipulation of tonicity in the intestinal lumen. PMID:18270543

  20. [Treatment of retinal detachment with macular hole].

    PubMed

    Pikulski, Z; Nawrocki, J; Dziegielewski, K

    1993-01-01

    The methods and results of surgery in 6 cases of retinal detachment with macular hole are presented. In all 6 cases pars plana vitrectomy was performed, in 4 with subsequent SF6 and in 2 with silicone oil tamponade. Retinal attachment was achieved in 4 eyes. Visual acuity 1/50-2/50 was found after surgery in 5 cases. The follow-up ranged from 6 to 9 months.

  1. [Treatment of retinal detachment with macular hole].

    PubMed

    Pikulski, Z; Nawrocki, J; Dziegielewski, K

    1993-06-01

    The authors presented 6 cases of macular hole retinal detachment in which pars plana vitrectomy with endo-tamponade was performed; in 4 cases SF6 gas and in 2, with PVR silicone oil was used. Retina was completely attached in 4 eyes. Visual acuity 1/50 to 2/50 was achieved in 5 eyes. Follow-up ranged from 5 to 9 months.

  2. Retinal detachment: is reparative surgery always mandatory?

    PubMed Central

    Jarrett, W H

    1988-01-01

    The author reports 16 cases of rhegmatogenous retinal detachment in which, for a variety of reasons, immediate reparative surgery was not carried out. To date, one-half of these cases have not been operated, and four have been followed for 6 years or longer. No case suffered visual loss because of the delay in surgery, nor has chronic inflammation, glaucoma, or rubeosis been a problem. The clinical characteristics of this group of cases is defined. PMID:2979020

  3. Edge and divertor plasma: detachment, stability, and plasma-wall interactions

    NASA Astrophysics Data System (ADS)

    Krasheninnikov, S. I.; Kukushkin, A. S.; Lee, Wonjae; Phsenov, A. A.; Smirnov, R. D.; Smolyakov, A. I.; Stepanenko, A. A.; Zhang, Yanzeng

    2017-10-01

    The paper presents an overview of the results of studies on a wide range of the edge plasma related issues. The rollover of the plasma flux to the target during progressing detachment process is shown to be caused by the increase of the impurity radiation loss and volumetric plasma recombination, whereas the ion-neutral friction, although important for establishing the necessary edge plasma conditions, does not contribute per se to the rollover of the plasma flux to the target. The processes limiting the power loss by impurity radiation are discussed and a simple estimate of this limit is obtained. Different mechanisms of meso-scale thermal instabilities driven by impurity radiation and resulting in self-sustained oscillations in the edge plasma are identified. An impact of sheared magnetic field on the dynamics of the blobs and ELM filaments playing an important role in the edge and SOL plasma transport is discussed. Trapping of He, which is an intrinsic impurity for the fusion plasmas, in the plasma-facing tungsten material is considered. A newly developed model, accounting for the generation of additional He traps caused by He bubble growth, fits all the available experimental data on the layer of nano-bubbles observed in W under irradiation by low energy He plasma.

  4. WIDE-FIELD INFRARED IMAGING: A Descriptive Review of Characteristics of Retinoschisis, Retinal Detachment, and Schisis Detachments.

    PubMed

    Ho, Vincent Y; Wehmeier, Jarrod M; Shah, Gaurav K

    2016-08-01

    Retinoschisis and retinal detachments are primarily differentiated based on characteristic examination findings. In diagnostically challenging cases, noncontact wide-field infrared imaging can help diagnosis and visualize the extent/margins of retinoschisis, retinal detachment, or combined schisis detachments by comparing reflectivity patterns. This is a retrospective, observational, descriptive case series of 14 eyes of 14 nonconsecutive patients, ranging from 28 to 89 years old (mean 61), diagnosed with retinoschisis, retinal detachment, or schisis detachment from May 5, 2014 to March 4, 2015. Patients with secondary retinoschisis and/or retinal detachment from other causes were not included in the study. Heidelberg Wide-Field Module lens and Heidelberg Spectralis HRA+OCT machine (Heidelberg Engineering, Heidelberg, Germany) were used to obtain noncontact, wide-field infrared images on each study eye. Seven eyes with retinal detachments, four with retinoschises, and three with schisis detachments were imaged using this novel wide-field infrared technique. Retinoschisis appears light and translucent with prominent vasculature, retinal detachments appear dark and opaque, and combined retinoschisis/retinal detachment exhibit mixed reflectivity patterns. Wide-field infrared imaging provides a quick, noncontact, noninvasive method to accurately diagnose and to monitor for progression of retinoschisis, retinal detachment, or combined schisis detachments.

  5. LITERATURE REVIEWS TO SUPPORT ION EXCHANGE TECHNOLOGY SELECTION FOR MODULAR SALT PROCESSING

    SciTech Connect

    King, W

    2007-11-30

    This report summarizes the results of literature reviews conducted to support the selection of a cesium removal technology for application in a small column ion exchange (SCIX) unit supported within a high level waste tank. SCIX is being considered as a technology for the treatment of radioactive salt solutions in order to accelerate closure of waste tanks at the Savannah River Site (SRS) as part of the Modular Salt Processing (MSP) technology development program. Two ion exchange materials, spherical Resorcinol-Formaldehyde (RF) and engineered Crystalline Silicotitanate (CST), are being considered for use within the SCIX unit. Both ion exchange materials have been studied extensively and are known to have high affinities for cesium ions in caustic tank waste supernates. RF is an elutable organic resin and CST is a non-elutable inorganic material. Waste treatment processes developed for the two technologies will differ with regard to solutions processed, secondary waste streams generated, optimum column size, and waste throughput. Pertinent references, anticipated processing sequences for utilization in waste treatment, gaps in the available data, and technical comparisons will be provided for the two ion exchange materials to assist in technology selection for SCIX. The engineered, granular form of CST (UOP IE-911) was the baseline ion exchange material used for the initial development and design of the SRS SCIX process (McCabe, 2005). To date, in-tank SCIX has not been implemented for treatment of radioactive waste solutions at SRS. Since initial development and consideration of SCIX for SRS waste treatment an alternative technology has been developed as part of the River Protection Project Waste Treatment Plant (RPP-WTP) Research and Technology program (Thorson, 2006). Spherical RF resin is the baseline media for cesium removal in the RPP-WTP, which was designed for the treatment of radioactive waste supernates and is currently under construction in Hanford, WA

  6. Extinguishing ELMs in detached radiative divertor plasmas

    NASA Astrophysics Data System (ADS)

    Pigarov, Alexander; Krasheninnikov, Sergei; Rognlien, Thomas

    2016-10-01

    In order to avoid deleterious effects of ELMs on PFCs in next-step fusion devices it has been suggested to operate with small-sized ELMs naturally extinguishing in the divertor. Our modeling effort is focusing at extinguishing type-I ELMs: conditions for expelled plasma dissipation; efficiency of ELM power handling by detached radiative divertors; and the ELM impact on detachment state. Here time-dependent modeling of a sequence of many ELMs was performed with 2-D edge plasma transport code UEDGE-MB-W which incorporates the Macro-Blob (MB) approach to simulate non-diffusive filamentary transport and various ``Wall'' (W) models for time-dependent hydrogen wall inventory and recycling. Three cases were modeled, in which extinguishing ELMs are achieved due to: (i) intrinsic impurities via graphite sputtering, (ii) extrinsic impurity gas puff (Ne), and (iii) =(i) +(ii). For each case, we performed a series of UEDGE-MB-W runs scanning the deuterium and impurity inventories, pedestal losses and ELM frequency. Temporal variations of the degree of detachment, ionization front shape, recombination sink strength, radiated fraction, peak power loads, OSP, impurity charge states, and in/out asymmetries were analyzed. We discuss the onset of extinguishing ELMs, conditions for not burning through and enhanced plasma recombination as functions of scanned parameters. Efficiencies of intrinsic and extrinsic impurities in ELM extinguishing are compared.

  7. A new scaling for divertor detachment

    DOE PAGES

    Goldston, R. J.; Reinke, M. L.; Schwartz, J. A.

    2017-03-29

    The ITER design, and future reactor designs, depend on divertor `detachment,'whether partial, pronounced or complete, to limit heat flux to plasma-facing components and to limit surface erosion due to sputtering. It would be valuable to have a measure of the difficulty of achieving detachment as a function of machine parameters, such as input power, magnetic field, major radius, etc. Frequently the parallel heat flux, estimated typically as proportional to P-sep/R or PsepB/R, is used as a proxy for this difficulty. Here we argue that impurity cooling is dependent on the upstream density, which itself must be limited by a Greenwald-likemore » scaling. Taking this into account self-consistently, we find the impurity fraction required for detachment scales dominantly as power divided by poloidal magnetic field. The absence of any explicit scaling with machine size is concerning, as P-sep surely must increase greatly for an economic fusion system, while increases in the poloidal field strength are limited by coil technology and plasma physics. This result should be challenged by comparison with 2D divertor codes and with measurements on existing experiments. Nonetheless, it suggests that higher magnetic field, stronger shaping, double-null operation, `advanced' divertor configurations, as well as alternate means to handle heat flux such as metallic liquid and/or vapor targets merit greater attention.« less

  8. Axial eye length after retinal detachment surgery.

    PubMed

    Vukojević, Nenad; Sikić, Jakov; Curković, Tihomir; Juratovac, Zlatko; Katusić, Damir; Sarić, Borna; Jukić, Tomislav

    2005-01-01

    Changes in the eye axial diameter were studied to assess the eye globe impact of conventional operation for retinal detachment. The study included 69 eyes in 69 patients operated on for rhegmatogenous retinal detachment. There were 46.4% of men and 53.6% of women, mean age 52.7 (+/- 15.21) years. Results of preoperative and postoperative ultrasonographic measurement of axial diameter are presented. The mean preoperative and postoperative eye axial diameter was 23.69 (+/- 1.84) mm and 24.43 (+/- 1.91) mm, respectively. Postoperative results showed the axial eye length to increase by a mean of 0.74 (+/- 0.44) mm, yielding a statistically significant difference from the preoperative measurement (p < 0.001). The mean myopia induced by this eyeball elongation was 1.77 D. The encircling band with and without segmental buckling used in surgical repair of retinal detachment creates circular and segmental indentation of the eyeball, thus increasing its axial length. The myopia induced by elongation of the eyeball results in considerable myopia, which requires appropriate correction in the early postoperative period to achieve favorable vision rehabilitation.

  9. Interventions in pseudophakic rhegmatogenous retinal detachment.

    PubMed

    Lauritzen, Derek B; Avila, Marcos P; Buzney, Sheldon M; Weiter, John J

    2002-01-01

    With refinement of vitrectomy techniques over the past 30 years, the treatment of rhegmatogenous retinal detachment (RRD) has transitioned from the almost exclusive use of extraocular techniques to the present time in which intraocular interventions are available and, in some practices, enjoy almost exclusive use for primary repair of RRD. Except for those situations in which a retinal detachment is associated with obvious immediate complications related to the cataract surgery, the considerations for the treatment of pseudophakic RRD are quite similar to those of phakic RRD. The current options are: use of an extraocular buckling device, vitrectomy-related procedures, intraocular gas injection with associated retinopexy, and combinations of these. Disagreement on the ideal intervention for pseudophakic retinal detachment is not uncommon and particularly so in those RRDs which lie somewhere in the spectrum between complex and simple. As is so often the case in the surgical treatment of disease, there may not be one ideal technique for a particular type of RRD; but knowledge of alternatives logically increases the likelihood of a successful result. The goal of this paper is to outline the clinical factors shown to be of importance in deciding which technique will have the greatest chance at not only achieving retinal re-attachment but also in optimizing long-term vision.

  10. Experimental study on a new sterilization process using plasma source ion implantation with N2 gas

    NASA Astrophysics Data System (ADS)

    Yoshida, M.; Tanaka, T.; Watanabe, S.; Takagi, T.; Shinohara, M.; Fujii, S.

    2003-07-01

    Plasma source ion implantation (PSII) with negative high voltage pulses has been applied to the sterilization process as a technique suitable for sterilization of three-dimensional work pieces. Pulsed high negative voltage (0-10 μs pulse width, 900 pulses/s, -9 to -16 kV) was applied to the electrode in this process at a gas pressure of 2-7 Pa of N2. This process has been found to be capable of generating glow discharge plasma around a stainless electrode, on which quartz glass samples with biological materials are placed. We found that the PSII process reduced the numbers of active Bacillus pumilus cells using N2 gas plasma generated by pulsed dc voltages. The number of bacteria survivors was reduced by 105×with 5-10 min exposure. The state of cells on quartz glass was observed by scanning electron microscopy with and without exposure. We found that the ion energy is the most important processing parameter. The technique is demonstrated to be an effective means of low-temperature surface sterilization, with very little damage to the target.

  11. Inelastic processes in ion/surface collisions: Scattered ion fractions and VUV photon emission for Ne + and Ar + collisions with Mg and Y surfaces

    NASA Astrophysics Data System (ADS)

    Rabalais, J. Wayne; Chen, Jie-Nan; Kumar, R.; Narayana, M.

    1985-12-01

    Time-of-flight (TOF) scattering spectra and vacuum ultraviolet (VUV) photon emission spectra resulting from 1-10 keV Ne+ and Ar+ ions impinging on magnesium and yttrium surfaces and the corresponding oxidized and hydroxylated surfaces have been measured. Measurements of the scattered neutrals plus ions and neutrals only are used to calculate scattered ion fractions Y+ for the single scattering collisions. The Y+ values rise steeply at low ion energies E0 (˜1-2 keV), reaching values of 70% and 38% at 10 keV for Ne+/Mg and Ar+/Y, respectively, and are very sensitive to adsorbate coverage. The dominant photon emission observed from the clean metals in the VUV range 30-200 nm is 1,3P → 1S resonance radiation from the excited neutral projectile atoms; emission was also observed from excited H and O for adsorbate covered surfaces. A model is developed for electronic transitions in keV ion/surface collisions which considers Auger and resonant transitions along the ion trajectory and electron promotions in the quasidiatomic molecule of the close encounter. By making an assumption of equality in the close encounter, the model can be fitted to the experimental data, allowing determination of ionization PI and neutralization PN probabilities as a function of the distance of approach. The results show that electron promotions within MO's of the collision complex formed during encounter are significant, if not dominating, processes in keV ion surface collisions.

  12. Inelastic processes in ion/surface collisions: Direct recoil ion fractions as a function of kinetic energy

    NASA Astrophysics Data System (ADS)

    Rabalais, J. Wayne; Chen, Jie-Nan

    1986-09-01

    Time-of-flight (TOF) spectra of the scattered and recoiled particles resulting from 1-10 keV Ar+ ions impingent on surfaces of MgO, Mg(OH)2, graphite, Si, and SiO2 have been obtained. Measurements of directly recoiled (DR) neutrals plus ions and neutrals only are used to calculate positive and negative ion fractions Y+,- from DR events. These positive and negative ion yields observed for DR of H, C, O, and Si have distinctly different behavior as a function of ion kinetic energy. The Y+ values exhibit a ``threshold-type'' behavior with a steep rise followed by a slowly rising or plateau region at higher energy. The Y- values exhibit a maximum in the low energy region followed by a decreasing yield as energy increases. The Y-/Y+ ratio for C and O is very sensitive to the amount of hydrogen present, with the Y+ yields dropping as hydrogen concentration increases. The recently developed model for electronic transitions in keV ion/surface collisions which considers Auger and resonant transitions along the ion trajectory and electron promotions in the quasidiatomic molecule of the close atomic encounter is extended to include DR events. Analytical expressions for Y+,- are derived for the case of surface atoms in positive, neutral, and negative bonding environments. These model expressions are fitted to the experimental data, allowing determination of the probabilities of ionization in the close atomic encounter and of electron capture along the outgoing trajectory.

  13. Nanosecond Pulsed Laser Processing of Ion Implanted Single Crystal Silicon Carbide Thin Layers

    NASA Astrophysics Data System (ADS)

    Özel, Tuğrul; Thepsonthi, Thanongsak; Amarasinghe, Voshadhi P.; Celler, George K.

    The attractiveness of single crystal SiC in a variety of high power, high voltage, and high temperature device applications such as electric vehicles and jet engines is counteracted by the very high cost of substrates. Precision cutting of multiple micrometre thick SiC layers and transferring them to lower cost substrates would drive the cost down and allow expanding the use of single crystal SiC. In this study, laser beam processing has been utilized to exfoliate thin layers from a surface of single crystal SiC that was prepared with hydrogen and boron ion implantation. The layer thickness of 1 μm has been achieved by ion implantation that formed voids and microcracks under the surface at a layer of 150 nm thick. High energy laser pulses provided the layer removal and its transfer to bonded Si substrate has been shown. Exfoliated surfaces and topography have been evaluated with Scanning Electron Microscopy. Furthermore, thermal modelling of pulse laser irradiation of implanted multi-layer SiC material has been conducted and temperature profiles are obtained at different peak pulse intensity settings to optimize exfoliation process parameters. It was found that laser exfoliation mechanism can be further improved by higher optical absorptance of defect rich layer obtained with boron ion implantation.

  14. Non-aqueous Electrode Processing and Construction of Lithium-ion Coin Cells.

    PubMed

    Stein, Malcolm; Chen, Chien-Fan; Robles, Daniel J; Rhodes, Christopher; Mukherjee, Partha P

    2016-02-01

    Research into new and improved materials to be utilized in lithium-ion batteries (LIB) necessitates an experimental counterpart to any computational analysis. Testing of lithium-ion batteries in an academic setting has taken on several forms, but at the most basic level lies the coin cell construction. In traditional LIB electrode preparation, a multi-phase slurry composed of active material, binder, and conductive additive is cast out onto a substrate. An electrode disc can then be punched from the dried sheet and used in the construction of a coin cell for electrochemical evaluation. Utilization of the potential of the active material in a battery is critically dependent on the microstructure of the electrode, as an appropriate distribution of the primary components are crucial to ensuring optimal electrical conductivity, porosity, and tortuosity, such that electrochemical and transport interaction is optimized. Processing steps ranging from the combination of dry powder, wet mixing, and drying can all critically affect multi-phase interactions that influence the microstructure formation. Electrochemical probing necessitates the construction of electrodes and coin cells with the utmost care and precision. This paper aims at providing a step-by-step guide of non-aqueous electrode processing and coin cell construction for lithium-ion batteries within an academic setting and with emphasis on deciphering the influence of drying and calendaring.

  15. Mechanically Tunable, Readily Processable Ion Gels by Self-Assembly of Block Copolymers in Ionic Liquids.

    PubMed

    Lodge, Timothy P; Ueki, Takeshi

    2016-10-05

    Room temperature ionic liquids are of great interest for many advanced applications, due to the combination of attractive physical properties with essentially unlimited tunability of chemical structure. High chemical and thermal stability, favorable ionic conductivity, and complete nonvolatility are just some of the most important physical characteristics that make ionic liquids promising candidates for emerging technologies. Examples include separation membranes, actuators, polymer gel electrolytes, supercapacitors, ion batteries, fuel cell membranes, sensors, printable plastic electronics, and flexible displays. However, in these and other applications, it is essential to solidify the ionic liquid, while retaining the liquid state properties of interest. A broadly applicable solidification strategy relies on gelation by addition of suitable triblock copolymers with the ABA architecture, producing ion gels or ionogels. In this paradigm, the A end blocks are immiscible with the ionic liquid, and consequently self-assemble into micellar cores, while some fraction of the well-solvated B midblocks bridge between micelles, forming a percolating network. The chemical structures of the A and B repeat units, the molar mass of the blocks, and the concentration of the copolymer in the ionic liquid are all independently tunable to attain desired property combinations. In particular, the modulus of the resulting ion gel can be readily varied between 100 Pa and 1 MPa, with little sacrifice of the transport properties of the ionic liquid, such as ionic conductivity or gas diffusivity. Suitable A blocks can impart thermoreversible gelation (with solidification either on heating or cooling) or even photoreversible gelation. By virtue of the nonvolatility of ionic liquids, a wide range of processing strategies can be employed directly to prepare ion gels in thin or thick film forms, including solvent casting, spin coating, aerosol jet printing, photopatterning, and transfer

  16. Process for carbonaceous material conversion and recovery of alkali metal catalyst constituents held by ion exchange sites in conversion residue

    DOEpatents

    Sharp, David W.

    1980-01-01

    In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered for the particles by contacting or washing them with an aqueous solution containing calcium or magnesium ions in an alkali metal recovery zone at a low temperature, preferably below about 249.degree. F. During the washing or leaching process, the calcium or magnesium ions displace alkali metal ions held by ion exchange sites in the particles thereby liberating the ions and producing an aqueous effluent containing alkali metal constituents. The aqueous effluent from the alkali metal recovery zone is then recycled to the conversion process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

  17. Studies of acceleration processes in the corona using ion measurements on the solar probe mission

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.

    1978-01-01

    The energy spectra and composition of particles escaping from the Sun provide essential information on mechanisms responsible for their acceleration, and may also be used to characterize the regions where they are accelerated and confined and through which they propagate. The suprathermal energy range, which extends from solar wind energies (approximately 1 KeV) to about 1 MeV/nucleon, is of special interest to studies of nonthermal acceleration processes because a large fraction of particles is likely to be accelerated into this energy range. Data obtained from near earth observations of particles in the suprathermal energy range are reviewed. The necessary capabilities of an a ion composition experiment in the solar probe mission and the required ion measurements are discussed. A possible configuration of an instrument consisting of an electrostatic deflection system, modest post acceleration, and a time of flight versus energy system is described as well as its possible location on the spacecraft.

  18. Comparison between cylindrical and prismatic lithium-ion cell costs using a process based cost model

    NASA Astrophysics Data System (ADS)

    Ciez, Rebecca E.; Whitacre, J. F.

    2017-02-01

    The relative size and age of the US electric vehicle market means that a few vehicles are able to drive market-wide trends in the battery chemistries and cell formats on the road today. Three lithium-ion chemistries account for nearly all of the storage capacity, and half of the cells are cylindrical. However, no specific model exists to examine the costs of manufacturing these cylindrical cells. Here we present a process-based cost model tailored to the cylindrical lithium-ion cells currently used in the EV market. We examine the costs for varied cell dimensions, electrode thicknesses, chemistries, and production volumes. Although cost savings are possible from increasing cell dimensions and electrode thicknesses, economies of scale have already been reached, and future cost reductions from increased production volumes are minimal. Prismatic cells, which are able to further capitalize on the cost reduction from larger formats, can offer further reductions than those possible for cylindrical cells.

  19. Energetic ion beams in semiconductor processing: Summary of a DOE panel study

    SciTech Connect

    Picraux, S.T.; Cchason, E.; Poate, J.M.

    1995-12-31

    The trend toward smaller dimensions in integrated circuit technology presents severe physical and engineering challenges for ion implantation. These challenges, together with the need for physically-based models at exceedingly small dimensions, are leading to a new level of understanding of fundamental defect science in silicon. Recently the DOE Council on Materials requested that our panel examine the current status and future research opportunities in the area of ion beams in semiconductor processing. Particularly interesting are the emerging approaches to defect and dopant distribution modeling, transient enhanced diffusion, high energy implantation and defect accumulation, and metal impurity gettering. These topics were explored both from the perspective of emerging science issues and technology challenges.

  20. Critical problems of ion implantation in processing small geometry integrated devices

    NASA Astrophysics Data System (ADS)

    Tokuyama, Takashi

    1989-02-01

    A brief review is described on the critical problems of ion implantation in processing small geometry integrated devices. The commonly recognized critical paths of the technology, i.e. formation of shallow junctions, impurity doping of vertical side walls, shadowing and the scattering effect of the incident beam are discussed based on recent data. Discussion is also given of the annealing behavior and residual defects of small and isolated implanted regions, and the considerable difference from those of the continuous implanted layers is shown. These problems are more or less related to the fundamental principles of implantation that impurities are doped by the incidence of energetic ions. Based on these facts, attempts are made to estimate the final size of the future devices to which implantation can be applied.

  1. Optimizing the treatment of rhegmatogenous retinal detachment.

    PubMed

    Hajari, Javad Nouri

    2016-03-01

    Surgical approaches for rhegmatogenous retinal detachment (RRD) have evolved rapidly in the past century. This has resulted in an increase in the anatomical success rate from zero per cent in the beginning of the 1900s to now almost 100 per cent. Rhegmatogenous retinal detachment is regarded as an acute eye disease that needs immediate treatment. With the increasing number of cataract surgeries and an increased elderly population, the numbers of RRD occurrences are increasing. The aim of this thesis is to create knowledge on how treatment and care of RRD patients can be optimized. In the first paper, data on the incidence of RRD in Denmark are presented based on data from a nation register the National Patient Registry (NPR). It was discovered that the incidence of RRD in Denmark is similar to previous reported numbers and that the incidence has been increasing due to increasing numbers of cataract surgeries and an increased elderly population. Using data from the NPR, we estimated that the risk of a RRD occurring on the fellow eye is 100 times larger than on the first eye and that middle aged men have the highest risk. Having an increase in the incidence of RRD we need to ensure that the patients are also treated in the most optimal way. To ensure this, an indicator is needed to monitor the quality at the different centres. This indicator presented in the second paper is based in the occurrence of redetachment. We define a detachment to be caused by poor surgery if the retina detaches within one year after initial surgery with pneumatic retinopexy, scleral buckling and VTX with gas, and one and a half years after surgery with VTX with oil. Also lack of oil removal within the first year is a failed operation. It is widely accepted that RRD is an acute disease but when should surgery be performed to attain the most optimal result? In the third paper, we evaluated the progression of posterior RRD with an optical coherence tomography to make an objective assessment of

  2. Coastal Response, a system of detached breakwaters

    NASA Astrophysics Data System (ADS)

    García Ortiz, Isabelo; Negro Valdecantos, Vicente; Santos López, Jose; Esteban, María Dolores

    2017-04-01

    The coastline's sedimentary response in the form of a tombolo or semi-tombolo (salient) as a result of the construction of detached breakwaters is an aspect that should be known in the design phase so that these marine structures may be properly designed. In achieving an ecological, social and economic value, such areas must also be properly managed. All design methods in existence since Dean (1978) are mainly based on hypotheses formulated from geometric studies on existing formations. No relationship at all is established with climate and littoral dynamics typical of the location (only Suh and Darlymple (1987) and the Japanese Ministry of Construction (1986) present relationships depending on wave variables). Neither has the influence on systems with more than two breakwaters been studied. These methods are not fully adapted to the cases existing on the Spanish Mediterranean littoral. The lines of investigation as proposed by L. Bricio and V. Negro (2010) were continued with for this study. These researchers developed a method for dimensioning isolated, detached breakwaters and their semi-tombolo or tombolo associated formations using all the characteristics of the site (energy, geometric and structural), specific climate and geomorphology and littoral dynamics' characteristics. This methodology is currently acknowledged and accepted in works undertaken on the Spanish Mediterranean littoral. A linear regression was obtained in the investigation undertaken on the 18 detached breakwater systems along the whole of the 1670 km of the Spanish Mediterranean littoral using the proposals made by L. Bricio and V. Negro. The adjustment of R2 ≥ 0.90 was used for the sandy, tombolo formations behind all the detached breakwater systems between several non-dimensional monomials displaying the most representative characteristics of the site. L/H12 + (2ṡB)/G =12,15ṡ(X/Xc)+7,3231 X: Distance of breakwaters from coastline Xc: Distance from coastline where the closure depth

  3. Electron attachment and detachment: Electron affinities of isomers of trifluoromethylbenzonitrile

    NASA Astrophysics Data System (ADS)

    Miller, Thomas M.; Viggiano, A. A.; Friedman, Jeffrey F.; Van Doren, Jane M.

    2004-11-01

    Rate constants for electron attachment to the three isomers of trifluoromethylbenzonitrile [(CF3)(CN)C6H4, or TFMBN] were measured over the temperature range of 303-463 K in a 133-Pa He buffer gas, using a flowing-afterglow Langmuir-probe apparatus. At 303 K, the measured attachment rate constants are 9.0×10-8 (o-TFMBN), 5.5×10-8 (m-TFMBN), and 8.9×10-8 cm3 s-1 (p-TFMBN), estimated accurate to ±25%. The attachment process formed only the parent anion in all three cases. Thermal electron detachment was observed for all three anion isomers, and rate constants for this reverse process were also measured. From the attachment and detachment results, the electron affinities of the three isomers of TFMBN were determined to be 0.70(o-TFMBN), 0.67(m-TFMBN), and 0.83 eV (p-TFMBN), all ±0.05 eV. G3(MP2) [Gaussian-3 calculations with reduced Møller-Plesset orders (MP2)] calculations were carried out for the neutrals and anions. Electron affinities derived from these calculations are in good agreement with the experimental values.

  4. Electron attachment and detachment: electron affinities of isomers of trifluoromethylbenzonitrile.

    PubMed

    Miller, Thomas M; Viggiano, A A; Friedman, Jeffrey F; Van Doren, Jane M

    2004-11-22

    Rate constants for electron attachment to the three isomers of trifluoromethylbenzonitrile [(CF(3))(CN)C(6)H(4), or TFMBN] were measured over the temperature range of 303-463 K in a 133-Pa He buffer gas, using a flowing-afterglow Langmuir-probe apparatus. At 303 K, the measured attachment rate constants are 9.0 x 10(-8) (o-TFMBN), 5.5 x 10(-8) (m-TFMBN), and 8.9 x 10(-8) cm(3) s(-1) (p-TFMBN), estimated accurate to +/-25%. The attachment process formed only the parent anion in all three cases. Thermal electron detachment was observed for all three anion isomers, and rate constants for this reverse process were also measured. From the attachment and detachment results, the electron affinities of the three isomers of TFMBN were determined to be 0.70(o-TFMBN), 0.67(m-TFMBN), and 0.83 eV (p-TFMBN), all +/-0.05 eV. G3(MP2) [Gaussian-3 calculations with reduced Møller-Plesset orders (MP2)] calculations were carried out for the neutrals and anions. Electron affinities derived from these calculations are in good agreement with the experimental values.

  5. Electric Field Effect on Bubble Detachment in Variable Gravity Environment

    NASA Technical Reports Server (NTRS)

    Iacona, Estelle; Herman, Cila; Chang, Shinan

    2003-01-01

    The subject of the present study, the process of bubble detachment from an orifice in a plane surface, shows some resemblance to bubble departure in boiling. Because of the high heat transfer coefficients associated with phase change processes, boiling is utilized in many industrial operations and is an attractive solution to cooling problems in aerospace engineering. In terrestrial conditions, buoyancy is responsible for bubble removal from the surface. In space, the gravity level being orders of magnitude smaller than on earth, bubbles formed during boiling remain attached at the surface. As a result, the amount of heat removed from the heated surface can decrease considerably. The use of electric fields is proposed to control bubble behavior and help bubble removal from the surface on which they form. The objective of the study is to investigate the behavior of individual air bubbles injected through an orifice into an electrically insulating liquid under the influence of a static electric field. Bubble cycle life were visualized in terrestrial conditions and for several reduced gravity levels. Bubble volume, dimensions and contact angle at detachment were measured and analyzed for different parameters as gravity level and electric field magnitude. Situations were considered with uniform or non-uni form electric field. Results show that these parameters significantly affect bubble behavior, shape, volume and dimensions.

  6. Electron Spectroscopy In Heavy-Ion Storage Rings: Resonant and Non-Resonant Electron Transfer Processes

    SciTech Connect

    Hagmann, S.; Stoehlker, Th.; Trotsenko, S.; Kozhuharov, Ch.; Spillmann, U.; Bosch, F.; Liesen, D.; Winters, D.; Hillenbrand, P.-M.; Shabaev, V.; Tupitsyn, I.; Kozhedub, Y.; Rothard, H.; Reuschl, R.; Ullrich, J.; Moshammer, R.; Voitkiv, A.; Surzhykov, A.; Fischer, D.; Doerner, R.

    2011-06-01

    Whereas our understanding of total cross sections for ionization and capture processes in ion-atom collisions is widely viewed as having arrived at a state of adequate maturity, the same cannot be said at all about the dynamics of collisions, multi-electron processes or the electron continua (in target and projectile) which are at the origin of total cross sections. We depict how these processes can be studied favourably in storage ring environments. We present examples of resonant and non-resonant electron transfer processes, radiative and non-radiative. This is elucidated via the relation of the electron nucleus bremsstrahlung at the high energy tip of the bremsstrahlung spectrum to the radiative electron capture cusp (RECC) and a new approach to determining molecular orbital binding energies in superheavy quasi-molecules in resonant KK charge transfer.

  7. Numerical computational of fluid flow through a detached retina

    NASA Astrophysics Data System (ADS)

    Jiann, Lim Yeou; Ismail, Zuhaila; Shafie, Sharidan; Fitt, Alistair

    2015-02-01

    In this paper, a phenomenon of fluid flow through a detached retina is studied. Rhegmatogeneous retinal detachment happens when vitreous humour flow through a detached retina. The exact mechanism of Rhegmatogeneous retinal detachment is complex and remains incomplete. To understand the fluid flow, a paradigm mathematical model is developed and is approximated by the lubrication theory. The numerical results of the velocity profile and pressure distribution are computed by using Finite Element Method. The effects of fluid mechanical on the retinal detachment is discussed and analyzed. Based on the analysis, it is found that the retinal detachment deformation affects the pressure distribution. It is important to comprehend the development of the retinal detachment so that a new treatment method can be developed.

  8. Psychological Detachment in the Relationship between Job Stressors and Strain

    PubMed Central

    Safstrom, My; Hartig, Terry

    2013-01-01

    We investigated the mediating versus moderating role of psychological detachment in the relationship between job stressors and psychological strain. Our sample consisted of 173 university students invested in challenging programs of advanced professional studies, who could find it difficult to detach from work. Hierarchical regression analyses of cross-sectional survey data affirmed the role of psychological detachment as a mediator in the relationship between job demands and perceived stress. Detachment also mediated the relationship between job demands and satisfaction with life, although the association disappeared when controlling for negative affectivity. Detachment did not mediate relationships between job demands and cognitive failures. Psychological detachment did not moderate any of the investigated relationships. The study contributes to a view of psychological detachment as less subject to individual differences than to the imposition of stressors in the given context. PMID:25379246

  9. Field reversal effects on divertor plasmas under radiative and detached conditions in JT-60U

    NASA Astrophysics Data System (ADS)

    Asakura, N.; Hosogane, H.; Tsuji-Iio, S.; Itami, K.; Shimizu, K.; Shimada, M.

    1996-06-01

    Reversal effects of the toroidal field Bt on the principal divertor plasma parameters were investigated under radiative and detached divertor conditions in L mode discharges. The ion flux to the inboard separatrix strike point decreased before a MARFE occurred, irrespective of the ion Del B drift direction. The local electron temperature, Te, div, decreased to around 10 eV. The maximum fraction of power radiated in the divertor was comparable between the two directions of Bt. With the power flowing into the two divertor fans being slightly larger on the outboard than on the inboard, a nearly symmetric in-out heat load was observed for the ion Del B drift away from the target. This was due to the outboard enhanced asymmetries in the particle flux and radiation loss distributions. From the viewpoint of in-out symmetry in the target heat load and Te, div, operation with the ion Del B drift away from the target plate is desirable as long as the attached divertor condition is maintained. On the contrary, during the MARFE, although deterioration of the energy confinement as well as the increase in the fuelling efficiency were comparable, for the ion Del B drift towards the target the plasma did not detach completely, and the strong in-out asymmetry in the particle recycling was relaxed to a relatively symmetric distribution. From the viewpoint of particle exhaust to the divertor, operation with the ion Del B drift towards the target is favourable

  10. Detaching droplets in immiscible fluids from a solid substrate with the help of electrowetting.

    PubMed

    Hong, Jiwoo; Lee, Sang Joon

    2015-02-07

    The detachment (or removal) of droplets from a solid surface is an indispensable process in numerous practical applications which utilize digital microfluidics, including cell-based assay, chip cooling, and particle sampling. When a droplet that is fully stretched by impacting or electrowetting is released, the conversion of stored surface energy to kinetic energy can lead to the departure of the droplet from a solid surface. Here we firstly detach sessile droplets in immiscible fluids from a hydrophobic surface by electrowetting. The physical conditions for droplet detachment depend on droplet volume, viscosity of ambient fluid, and applied voltage. Their critical conditions are determined by exploring the retracting dynamics for a wide range of driving voltages and physical properties of fluids. The relationships between physical parameters and dynamic characteristics of retracting and jumping droplets, such as contact time and jumping height, are also established. The threshold voltage for droplet detachment in oil with high viscosity is largely reduced (~70%) by electrowetting actuations with a square pulse. To examine the applicability of three-dimensional digital microfluidic (3D-DMF) platforms to biological applications such as cell culture and cell-based assays, we demonstrate the detachment of droplets containing a mixture of human umbilical vein endothelial cells (HUVECs) and collagen (concentration of 4 × 10(4) cells mL(-1)) in silicone oil with a viscosity of 0.65 cSt. Furthermore, to complement the technical limitations due to the use of a needle electrode and to demonstrate the applicability of the 3D-DMF platform with patterned electrodes to chemical analysis and synthesis, we examine the transport, merging, mixing, and detachment of droplets with different pH values on the platform. Finally, by using DC and AC electrowetting actuations, we demonstrate the detachment of oil droplets with a very low contact angle (<~13°) in water on a hydrophobic

  11. The channeling effect of Al and N ion implantation in 4H-SiC during JFET integrated device processing

    NASA Astrophysics Data System (ADS)

    Lazar, M.; Laariedh, F.; Cremillieu, P.; Planson, D.; Leclercq, J.-L.

    2015-12-01

    A strong channeling effect is observed for the ions of Al and N implanted in 4H-SiC due to its crystalline structure. This effect causes difficulties in subsequent accurate estimation of the depth of junctions formed by multiple ion implantation steps. A variety of lateral JFET transistors integrated on the same 4H-SiC wafer have been fabricated. Secondary Ion Mass Spectrometry measurements and Monte-Carlo simulations were performed in order to quantify and control the channeling effect of the implanted ions. A technological process was established enabling to obtain devices working with the presence of the channeling effect.

  12. Aluminum-Cycle Ion Exchange Process for Hardness Removal: A New Approach for Sustainable Softening.

    PubMed

    Li, Jinze; Koner, Suman; German, Michael; SenGupta, Arup K

    2016-11-01

    From a sustainability viewpoint, sodium exchange softening, although used widely, is under scrutiny due to its production of excess Na-laden spent regenerant and subsequent discharge to the environment. Many arid regions are introducing regulations disallowing dumping of concentrated sodium salts, the residuals from popular Na-exchange softening. The sodium content of the softened water is, also, always higher than in the feed, which poses a dietary health concern when used for drinking or cooking. An efficient, easy-to-operate hardness removal process with reduced sodium in both the treated water and in the spent regenerant is an unmet global need. Use of a cation exchange resin in Al(3+)-form for hardness removal, that is, exchange of divalent Ca(2+) or Mg(2+) with trivalent Al(3+), is counterintuitive, and this is particularly so, because the aluminum ion to be exchanged has higher affinity than calcium. Nevertheless, ion exchange accompanied by precipitation of aluminum hydroxide allows progress of the cation exchange reaction leading to hardness removal. Experimental results demonstrated that calcium can be consistently removed for multiple cycles using a stoichiometric amount of AlCl3 as the regenerant. The process essentially operates at the maximum possible thermodynamic efficiency: removal of one equivalent of Ca(2+) corresponds to use of one equivalent of Al(3+) as a regenerant. During the Al-cycle process there is no increase in Na(+) concentration and partial reduction in the total dissolved solids (TDS) of the treated water. It is noteworthy that the ion-exchange resin used, components of the fixed-bed column and operational protocol are nearly the same as traditional softening processes on Na-cycle. Thus, existing Na-cycle systems can be retrofitted into Al-cycle operation without major difficulty.

  13. Measurements of lithium-ion concentration equilibration processes inside graphite electrodes

    NASA Astrophysics Data System (ADS)

    Kindermann, Frank M.; Osswald, Patrick J.; Klink, Stefan; Ehlert, Günter; Schuster, Jörg; Noel, Andreas; Erhard, Simon V.; Schuhmann, Wolfgang; Jossen, Andreas

    2017-02-01

    Methods for estimating inner states in a lithium-ion cell require steady state conditions or accurate models of the dynamic processes. Besides often used inner states such as state-of-charge, state-of-health or state-of-function, relaxation processes strongly influence the mentioned states. Inhomogeneous utilization of electrodes and consequent limitations in the operating conditions have recently been brought to attention. Relaxation measurements after an inhomogeneous current distribution through the thickness of an electrode have not been addressed so far. By using a previously developed laboratory cell, we are able to show an inhomogeneous retrieval of lithium-ions from a graphite electrode through the layer with spatial resolution. After this inhomogeneity caused by a constant current operation, equilibration processes are recorded and can be assigned to two different effects. One effect is an equilibration inside the particles (intra-particle) from surface to bulk and vice versa. The other effect is an assimilation between the particles (inter-particle) to reach a homogeneous state-of-charge in each particle throughout the electrode layer. While intra-particle relaxation is observed to be finished within 4 h, inter-particle relaxation through the layer takes more than 40 h. The overall time for both equilibration processes shows to be in the order of 48 h.

  14. The disappearance and reappearance of Titan's detached haze layer

    NASA Astrophysics Data System (ADS)

    West, Robert; Rannou, Pascal; Lavvas, Panayotis; Seignovert, Benoit; Turtle, Elizabeth P.; Perry, Jason; Ovanessian, Aida; Roy, Mou

    2016-10-01

    Titan's extended haze is a prominent and long-lived feature of the atmosphere that encompasses a rich variety of chemical, dynamical and microphysical processes operating over a wide range of temporal and spatial scales. The so-called 'detached' haze layer is easily seen in high-resolution short-wave (near-UV and blue wavelengths) images and is a consequence of a nearly global (outside of the winter polar hood region) layer depleted in aerosol content. It was first seen near 350 Km altitude in Voyager images (Rages and Pollack, 1983) and later observed by the Cassini ISS cameras (Porco et al., 2005; West et al., 2010) and UV stellar occultation profiles (Koskinen et al. 2011). A series of Cassini images from 2009 to 2010 revealed what appears to be a seasonally related altitude variation with remarkable regularity (comparing the Voyager and Cassini images). The drop in altitude is most rapid at equinox. Here we report on images of the upper haze layer over the period 2012 to early 2016. In the early part of this period the detached haze continued to drop in altitude and disappeared. There was no evidence for it beginning late in 2012 and extending to early 2016 when it was again detected with very low contrast at an altitude near 500 Km. We document this behavior and examine the evolution of the haze as functions of both latitude and time. These new details put additional constraints on models that attempt to account for the existence of the detached layer. Part of this work was done by the Jet Propulsion Laboratory, California Institute of Technology. References: Rages, K., and J. B. Pollack (1983), Vertical distribution of scattering hazes in Titan's upper atmosphere, Icarus, 55, 50-62, doi:10.1016/0019-1035 (83)90049-0; Porco, C. C. et al., Imaging Titan from the Cassini Spacecraft, Nature 434, 159-168 (2005); West, R. A. et al., The evolution of Titans detached haze layer near equinox in 2009", Geophys. Res. Lett. 38, L06204, doi:10.1029/2011GL046843, 2011

  15. A Case Study of Ion Implant In-Line Statistical Process Control

    NASA Astrophysics Data System (ADS)

    Zhao, Zhiyong; Ramczyk, Kenneth; Hall, Darcy; Wang, Linda

    2005-09-01

    Ion implantation is one of the most critical processes in the front-end-of-line for ULSI manufacturing. With more complexity in device layout, the fab cycle time can only be expected to be longer. To ensure yield and consistent device performance it is very beneficial to have a Statistical Process Control (SPC) practice that can detect tool issues to prevent excursions. Also, implanters may abort a process due to run-time issues. It requires human intervention to dispose of the lot. Since device wafers have a fixed flow plan and can only do anneal at certain points in the manufacturing process, it is not practical to use four-point probe to check such implants. Pattern recognition option on some of the metrology tools, such as ThermaWave (TWave), allows user to check an open area on device wafers for implant information. The two cited reasons prompted this work to look into the sensitivity of TWave with different implant processes and the possibility of setting up an SPC practice in a high-volume manufacturing fab. In this work, the authors compare the test wafer result with that of device wafers with variations in implant conditions such as dose, implant angle, energy, etc. The intention of this work is to correlate analytical measurement such as sheet resistance (Rs) and Secondary Ion Mass Spectrometry (SIMS) with device data such as electrical testing and sort yield. For a ± 1.5% TWave control limit with the tested implant processes in this work, this translates to about 0.5° in implant angle control or 2% to 8% dose change, respectively. It is understood that the dose sensitivity is not good since the tested processes are deep layer implants. Based on the statistics calculation, we assess the experimental error bar is within 1% of the measured values.

  16. Magnetic Nozzles for Plasma Thrusters: Acceleration, Thrust, and Detachment Mechanisms

    DTIC Science & Technology

    2011-10-01

    In the unmagnetized case the plasma is accelerated diffusively and some ion streamlines go backwards to the left dielectric wall , where ions are...processes related to the plasma wall interaction, virtual cathode considerations and anomalous diffusion. In this work, anomalous diffusion and virtual...demagnetized, which allows the development of the electric force and ion acceleration there, and increases the plasma flux to the wall . For β0 > 3 − 4

  17. Low pressure electrospray ionization system and process for effective transmission of ions

    DOEpatents

    Tang, Keqi [Richland, WA; Page, Jason S [Kennewick, WA; Kelly, Ryan T [West Richland, WA; Smith, Richard D [Richland, WA

    2012-05-08

    Systems and methods that provide up to complete transmission of ions between coupled stages with low effective ion losses. An "interfaceless" electrospray ionization system is further described that operates an electrospray at a reduced pressure such that standard electrospray sample solutions can be directly sprayed into an electrodynamic ion funnel which provides ion focusing and transmission of ions into a mass analyzer. Furthermore, chambers maintained at different pressures can allow for more optimal operating conditions for an electrospray emitter and an ion guide.

  18. Impact of natural organic matter properties on the kinetics of suspended ion exchange process.

    PubMed

    Bazri, Mohammad Mahdi; Mohseni, Madjid

    2016-03-15

    Removal kinetics of four standard organic matter isolates under the application of strongly basic ion exchange resins (IEX) in suspended mode was studied under commercial application conditions. Suwannee River natural organic matter (SRNOM), SR fulvic acid (SRFA), and Pony Lake fulvic acid (PLFA) were greatly removed (>90%) and highly preferred by IEX resins (α > 5, over Cl(-), and HCO3(-)) while SR humic acid (SRHA) was the least preferred organic structure among the four isolates studied (α ≈ 1). Moreover, the efficacy of removal for fulvic acids (i.e., SRFA, PLFA) was consistent over consecutive reuse of IEX resins (i.e., loading cycles) whereas it decreased for SRNOM and SRHA over the course of operation. The stoichiometric correlation between the chloride released from the resins as a result of organic molecules uptake indicated that ion exchange was the dominant mechanism. Results obtained indicated that molecular weight and charge density of isolates played a major role in the performance of ion exchange process for organic matter removal. Furthermore, various empirical and physical models were evaluated using the experimental data and pore diffusion was found to be the rate-liming step during the uptake of organic matters; hence, it was used as the appropriate model to predict the kinetics of removal. Consequently, free liquid diffusivities and effective pore diffusion coefficients of organic molecules were estimated and findings were in agreement with the literature data that were obtained from spectrophotometric methods.

  19. Purification process of natural graphite as anode for Li-ion batteries: chemical versus thermal

    NASA Astrophysics Data System (ADS)

    Zaghib, K.; Song, X.; Guerfi, A.; Rioux, R.; Kinoshita, K.

    The intercalation of Li ions in natural graphite that was purified by chemical and thermal processes was investigated. A new chemical process was developed that involved a mixed aqueous solution containing 30% H 2SO 4 and 30% NH xF y heated to 90 °C. The results of this process are compared to those obtained by heating the natural graphite from 1500 to 2400 °C in an inert environment (thermal process). The first-cycle coulombic efficiency of the purified natural graphite obtained by the chemical process is 91 and 84% after the thermal process at 2400 °C. Grinding the natural graphite before or after purification had no significant effect on electrochemical performance at low currents. However, grinding to a very small particle size before purification permitted optimization of the size distribution of the particles, which gives rise to a more homogenous electrode. The impurities in the graphite play a role as microabrasion agents during grinding which enhances its hardness and improves its mechanical properties. Grinding also modifies the particle morphology from a 2- to a 3-D structure (similar in shape to a potato). This potato-shaped natural graphite shows high reversible capacity at high current densities (about 90% at 1 C rate). Our analysis suggests that thermal processing is considerably more expensive than the chemical process to obtain purified natural graphite.

  20. Optimization of a plasma immersion ion implantation process for shallow junctions in silicon

    SciTech Connect

    Ray, Ashok; Nori, Rajashree; Bhatt, Piyush; Lodha, Saurabh; Pinto, Richard Rao, Valipe Ramgopal; Jomard, François; Neumann-Spallart, Michael

    2014-11-01

    A plasma immersion ion implantation (PIII) process has been developed for realizing shallow doping profiles of phosphorus and boron in silicon using an in-house built dual chamber cluster tool. High Si etch rates observed in a 5% PH{sub 3} in H{sub 2} plasma have been ascribed to high concentration of H(α) radicals. Therefore, subsequent work was carried out with 5% PH{sub 3} in He, leading to much smaller etch rates. By optical emission spectroscopy, the radical species H(α), PH*{sub 2}, and PH* have been identified. The concentration of all three species increased with pressure. Also, ion concentrations increased with pressure as evidenced by Langmuir data, with a maximum occurring at 0.12 mbar. The duty cycle of pulsed DC bias has a significant bearing on both the implantation and the etching process as it controls the leakage of positive charge collected at the surface of the silicon wafer during pulse on-time generated primarily due to secondary electron emission. The P implant process was optimized for a duty cycle of 10% or less at a pressure of 0.12 mbar with implant times as low as 30 s. Secondary ion mass spectroscopy showed a P dopant depth of 145 nm after rapid thermal annealing (RTA) at 950 °C for 5 s, resulting in a sheet resistance of 77 Ω/◻. Si n{sup +}/p diodes fabricated with phosphorus implantation using optimized PIII and RTA conditions exhibit J{sub on}/J{sub off} > 10{sup 6} with an ideality factor of nearly 1.2. Using similar conditions, shallow doping profiles of B in silicon have also been realized.

  1. Initial cost analysis of a desalination process utilizing hydrotalcite and permutite for ion sequestration.

    SciTech Connect

    Miller, James Edward; Evans, Lindsey R.

    2004-12-01

    An initial cost analysis of a proposed desalination process was performed. The proposed process utilizes tailored inorganic ion exchangers, hydrotalcite and permutite, to sequester anions and cations from a brackish water solution. Three different process scenarios were considered: (1) disposal of the spent exchangers as dry waste (2) conventional chemical regeneration, and (3) acid regeneration of permutite coupled with thermal (550 C) regeneration of hydrotalcite. Disposal of the resin and conventional regeneration are not viable options from an economic standpoint. Applying limited data and optimistic assumptions to the third scenario yielded an estimate of $2.34/kgal of product water. Published values for applying conventional reverse osmosis to similar water streams range from $0.70 to $2.65/kgal. Consistent with these baseline values, the Water Treatment Estimation Routine, WaTER, developed by the United States Department of the Interior, Bureau of Reclamation produced a cost estimate of $1.16/kgal for brackish water reverse osmosis.

  2. Remaining Useful Life Prediction for Lithium-Ion Batteries Based on Gaussian Processes Mixture

    PubMed Central

    Li, Lingling; Wang, Pengchong; Chao, Kuei-Hsiang; Zhou, Yatong; Xie, Yang

    2016-01-01

    The remaining useful life (RUL) prediction of Lithium-ion batteries is closely related to the capacity degeneration trajectories. Due to the self-charging and the capacity regeneration, the trajectories have the property of multimodality. Traditional prediction models such as the support vector machines (SVM) or the Gaussian Process regression (GPR) cannot accurately characterize this multimodality. This paper proposes a novel RUL prediction method based on the Gaussian Process Mixture (GPM). It can process multimodality by fitting different segments of trajectories with different GPR models separately, such that the tiny differences among these segments can be revealed. The method is demonstrated to be effective for prediction by the excellent predictive result of the experiments on the two commercial and chargeable Type 1850 Lithium-ion batteries, provided by NASA. The performance comparison among the models illustrates that the GPM is more accurate than the SVM and the GPR. In addition, GPM can yield the predictive confidence interval, which makes the prediction more reliable than that of traditional models. PMID:27632176

  3. Processing of silicon solar cells by ion implantation and laser annealing

    NASA Technical Reports Server (NTRS)

    Minnucci, J. A.; Matthei, K. W.; Greenwald, A. C.

    1981-01-01

    Methods to improve the radiation tolerance of silicon cells for spacecraft use are described. The major emphasis of the program was to reduce the process-induced carbon and oxygen impurities in the junction and base regions of the solar cell, and to measure the effect of reduced impurity levels on the radiation tolerance of cells. Substrates of 0.1, 1.0 and 10.0 ohm-cm float-zone material were used as starting material in the process sequence. High-dose, low-energy ion implantation was used to form the junction in n+p structures. Implant annealing was performed by conventional furnace techniques and by pulsed laser and pulsed electron beam annealing. Cells were tested for radiation tolerance at Spire and NASA-LeRC. After irradiation by 1 MeV electrons to a fluence of 10 to the 16th power per sq cm, the cells tested at Spire showed no significant process induced variations in radiation tolerance. However, for cells tested at Lewis to a fluence of 10 to the 15th power per sq cm, ion-implanted cells annealed in vacuum by pulsed electron beam consistently showed the best radiation tolerance for all cell resistivities.

  4. Focused ion-beam system for automated MEMS prototyping and processing

    NASA Astrophysics Data System (ADS)

    Athas, Gregory J.; Noll, Kathryn E.; Mello, Russell; Hill, Raymond; Yansen, Don E.; Wenners, Frank F.; Nadeau, James P.; Ngo, Tuan; Siebers, Michael

    1997-09-01

    We have developed a focused ion beam (FIB) system for automated MEMS processing. This product, the Micrion MicroMill, has been successfully used in production and prototype milling of over three million thin film heads (TFH) used in hard disk drives. The FIB column consists of a liquid gallium (Ga+) ion source, running at 50 kV, producing beam currents up to 50 nA. The milling rates achieved in the TFH application have been 0.5 - 4 micrometer3/sec with spot sizes ranging from 150 - 800 nm. This tool is designed to easily integrate into current FAB facilities and supports a wide range of navigational requirements. Different milling scenarios can be easily created or modified using the integrate CAD-like design tools, allowing for quick production line design modifications or rapid prototyping of new designs. The milling strategy can 'adapt' to dimensional changes caused by upstream process variations. On a real-time basis, the FIB system's pattern recognition/inspection software measures the individual part and precisely places the desired milling pattern. The flexible vector scan beam control can position the FIB, within sub-tenth micron dimensional control, to generate an endless variety of geometric milling patterns. This presentation will discuss the work currently done on inductive and magnetoresistive TFH devices as well as other potential MEMS processing applications.

  5. Focused-ion-beam post-processing technology for active devices

    NASA Astrophysics Data System (ADS)

    Tee, Chyng Wen; Lau, Fat Kit; Zhao, Xin; Penty, Richard; White, Ian

    2006-09-01

    Focused ion beam (FIB) etching technology is a highly efficient post-processing technique with the functionality to perform sputter etching and deposition of metals or insulators by means of a computer-generated mask. The high resolution and the ability to remove material directly from the sample in-situ make FIB etching the ideal candidate for device prototyping of novel micro-size photonic component design. Furthermore, the fact that arbitrary profile can be etched directly onto a sample without the need to prepare conventional mask and photolithography process makes novel device research with rapid feedback from characterisation to design activities possible. In this paper, we present a concise summary of the research work in Cambridge based on FIB technology. We demonstrate the applicability of focussed ion beam post processing technology to active photonic devices research. Applications include the integration of advanced waveguide architectures onto active photonic components. We documents details on the integration of lens structure on tapered lasers, photonic crystals on active SOA-integrated waveguides and surface profiling of low-cost gain-guided vertical-cavity surface-emitting lasers. Furthermore, we discuss additional functions of FIB in the measurement of buried waveguide structures or the integration of total-internal-reflection (TIR) mirror in optical interconnect structures.

  6. Contribution of charge-transfer processes to ion-induced electron emission

    SciTech Connect

    Roesler, M.

    1996-12-01

    Charge changing events of ions moving inside metals are shown to contribute significantly to electron emission in the intermediate velocity regime via electrons coming from projectile ionization. Inclusion of equilibrium charge state fractions, together with two-electron Auger processes and resonant-coherent electron loss from the projectile, results in reasonable agreement with previous calculations for frozen protons, though a significant part of the emission is now interpreted in terms of charge exchange. The quantal character of the surface barrier transmission is shown to play an important role. The theory compares well with experimental observations for {ital H} projectiles. {copyright} {ital 1996 The American Physical Society.}

  7. Charge exchange processes involving highly charged ions and targets of interest in astrophysics and fusion plasmas

    NASA Astrophysics Data System (ADS)

    Otranto, S.

    2012-11-01

    Renewed interest in charge exchange processes involving highly charged ions arises because of their crucial role in the planned ITER reactor as well as to recent X-ray observations in the astrophysical context. In this work, the classical trajectory Monte Carlo method (CTMC) is used to calculate state selective single charge exchange n-level cross sections and line emission cross sections pertinent to both fields. These are contrasted to recent laboratory data from KVI for the Xe18+ + Na(3s) collision system and NIST/BERLIN-EBIT data for the Ar18+ +Ar system.

  8. Multielectron Processes in Heavy Ion{endash}Atom Collisions at Intermediate Velocity

    SciTech Connect

    Vernhet, D.; Rozet, J.P.; Wohrer, K.; Chetioui, A.; Adoui, L.; Cassimi, A.; Grandin, J.P.; Ramillon, J.M.; Cornille, M.; Stephan, C.

    1997-11-01

    Using high resolution x-ray spectroscopy, we have measured projectile electron single and multiple cross sections when a two-electron Ar{sup 16+} ion collides with neutral target atoms. For a fixed impact velocity (v{sub p}=23 a.u. ) , but using various targets from He to Xe, a range from the perturbative regime to the strong interaction regime has been investigated. Double excitation cross sections are found to be well reproduced by an independent electron model. First measurements of capture-ionization cross sections are also reported and show the importance of this often-neglected process. {copyright} {ital 1997} {ital The American Physical Society}

  9. Oncogenic Ras differentially regulates metabolism and anoikis in extracellular matrix-detached cells.

    PubMed

    Mason, J A; Davison-Versagli, C A; Leliaert, A K; Pape, D J; McCallister, C; Zuo, J; Durbin, S M; Buchheit, C L; Zhang, S; Schafer, Z T

    2016-08-01

    In order for cancer cells to survive during metastasis, they must overcome anoikis, a caspase-dependent cell death process triggered by extracellular matrix (ECM) detachment, and rectify detachment-induced metabolic defects that compromise cell survival. However, the precise signals used by cancer cells to facilitate their survival during metastasis remain poorly understood. We have discovered that oncogenic Ras facilitates the survival of ECM-detached cancer cells by using distinct effector pathways to regulate metabolism and block anoikis. Surprisingly, we find that while Ras-mediated phosphatidylinositol (3)-kinase signaling is critical for rectifying ECM-detachment-induced metabolic deficiencies, the critical downstream effector is serum and glucocorticoid-regulated kinase-1 (SGK-1) rather than Akt. Our data also indicate that oncogenic Ras blocks anoikis by diminishing expression of the phosphatase PHLPP1 (PH Domain and Leucine-Rich Repeat Protein Phosphatase 1), which promotes anoikis through the activation of p38 MAPK. Thus, our study represents a novel paradigm whereby oncogene-initiated signal transduction can promote the survival of ECM-detached cells through divergent downstream effectors.

  10. Physiological and molecular changes of detached wheat leaves in responding to various treatments.

    PubMed

    Zhao, Lifeng; Zhang, Haoshan; Zhang, Bingjing; Bai, Xiaojuan; Zhou, Chunjiang

    2012-08-01

    Leaf senescence is induced or accelerated when leaves are detached. However, the senescence process and expression pattern of senescence-associated genes (SAGs) when leaves are detached are not clearly understood. To detect senescence-associated physiological changes and SAG expression, wheat (Triticum aestivum L.) leaves were detached and treated with light, darkness, low temperature (4 °C), jasmonic acid (JA), abscisic acid (ABA), and salicylic acid (SA). The leaf phenotypes, chlorophyll content, delayed fluorescence (DF), and expression levels of two SAGs, namely, TaSAG3 and TaSAG5, were analyzed. Under these different treatments, the detached leaves turned yellow with different patterns and varying chlorophyll content. DF significantly decreased after the dark, ABA, JA and SA treatments. TaSAG3 and TaSAG5, which are expressed in natural senescent leaves, showed different expression patterns under various treatments. However, both TaSAG3 and TaSAG5 were upregulated after leaf detachment. Our results revealed senescence-associated physiological changes and molecular differences in leaves, which induced leaf senescence during different stress treatments.

  11. Shear-Induced Detachment of Polystyrene Beads from SAM-Coated Surfaces.

    PubMed

    Cho, Kwun Lun; Rosenhahn, Axel; Thelen, Richard; Grunze, Michael; Lobban, Matthew; Karahka, Markus Leopold; Kreuzer, H Jürgen

    2015-10-13

    In this work we experimentally and theoretically analyze the detachment of microscopic polystyrene beads from different self-assembled monolayer (SAM) surfaces in a shear flow in order to develop a mechanistic model for the removal of cells from surfaces. The detachment of the beads from the surface is treated as a thermally activated process applying an Arrhenius Ansatz to determine the activation barrier and attempt frequency of the rate determing step in bead removal. The statistical analysis of the experimental shear detachment data obtained in phosphate-buffered saline buffer results in an activation energy around 20 kJ/mol, which is orders of magnitude lower than the adhesion energy measured by atomic force microscopy (AFM). The same order of magnitude for the adhesion energy measured by AFM is derived from ab initio calculations of the van der Waals interaction energy between the polystyrene beads and the SAM-covered gold surface. We conclude that the rate determing step for detachment of the beads is the initiation of rolling on the surface (overcoming static friction) and not physical detachment, i.e., lifting the particle off the surface.

  12. Importance of anisotropy in detachment rates for force production and cargo transport by a team of motor proteins.

    PubMed

    Takshak, Anjneya; Kunwar, Ambarish

    2016-05-01

    Many cellular processes are driven by collective forces generated by a team consisting of multiple molecular motor proteins. One aspect that has received less attention is the detachment rate of molecular motors under mechanical force/load. While detachment rate of kinesin motors measured under backward force increases rapidly for forces beyond stall-force; this scenario is just reversed for non-yeast dynein motors where detachment rate from microtubule decreases, exhibiting a catch-bond type behavior. It has been shown recently that yeast dynein responds anisotropically to applied load, i.e. detachment rates are different under forward and backward pulling. Here, we use computational modeling to show that these anisotropic detachment rates might help yeast dynein motors to improve their collective force generation in the absence of catch-bond behavior. We further show that the travel distance of cargos would be longer if detachment rates are anisotropic. Our results suggest that anisotropic detachment rates could be an alternative strategy for motors to improve the transport properties and force production by the team.

  13. Searching for heavy photons at Jefferson Lab using detached vertices

    NASA Astrophysics Data System (ADS)

    Weinstein, Lawrence; Szumila-Vance, Holly; HPS Collaboration Collaboration

    2017-01-01

    The Heavy Photon Search (HPS) experiment in Jefferson Lab Hall B will look for a new U(1) vector boson (called a ``heavy photon'', ``dark photon'', or A') in the mass range from 20 to 600 MeV/c2. This A' could potentially couple to the ordinary photon through kinetic mixing, which would create a coupling to electric charge of α' / α =ɛ2 . If so, then the A' can be produced through electron interactions with a heavy target through a process analogous to bremsstrahlung. The A' could then decay to e+e- . If the coupling ɛ is large, we can directly detect a peak in the e+e- mass spectrum above the dominant QED background. If ɛ is small, then we can look for e+e- events with a detached vertex resulting from A' decays downstream of the production target. In 2015 and 2016 we measured a few beam days each of 1.1 and 2.2 GeV electron scattering from tungsten using a large acceptance forward spectrometer consisting of a silicon vertex tracker located inside a dipole magnet and a lead tungstate electromagnetic calorimeter for triggering. This talk will present the detached vertex A' search, including preliminary results at 1.1 GeV if available.

  14. Slab detachment modelling: geodynamic regimes, topographic response, and rheological mechanisms

    NASA Astrophysics Data System (ADS)

    Duretz, Thibault; Gerya, Taras

    2010-05-01

    A set of numerical experiments were carried out to study the effect of slab breakoff on a subduction-collision system. The numerical code I2VIS (Gerya & Yuen, 2003) used for this purpose allows activation of plasticity, viscous creep and Peierls creep. A two-dimensional systematic study was performed by varying the oceanic slab age and initial plate convergence rate. In this parameter space, four different end-members were observed where breakoff depth can range from 40 to 400 km. Different combinations of rheological mechanisms lead to different breakoff modes. Activation of Peierls mechanism generally allows slabs to break faster and shallower. Each breakoff end-member has its own topographic signal evolution and always display a sharp breakoff signal. Averaged post-breakoff uplift rates ranges between 0,8 km/My for shallow detachment and 0,2 km/My for deep detachment in foreland and hinterland basins. Initiation of continental crust subduction was observed when using an oceanic lithosphere older than 30 My. Different exhumation processes such as slab retreat and eduction were observed. Large post-breakoff rebound associated with plate de- coupling occurs if the subducted oceanic slab is old enough. REFERENCES Gerya, T. V. & Yuen, D. A. 2003: Charaterictics-based marker method with conservative finite-difference schemes for modeling geological flows with strongly variable transport properties. Physics of the Earth an Planetary Interiors 140 (4), 293-318.

  15. Limestone weathering rates accelerated by micron-scale grain detachment

    NASA Astrophysics Data System (ADS)

    Emmanuel, S.; Levenson, Y.

    2014-12-01

    The weathering rates of carbonate rocks is often thought to be controlled by chemical dissolution, although some studies have suggested that mechanical erosion could also play an important role. Quantifying the rates of the different processes has proved challenging due to the high degree of variability encountered in both field and lab settings. To determine the rates and mechanisms controlling long-term limestone weathering, we analyse a lidar scan of the Western Wall, a Roman period edifice located in Jerusalem. Weathering rates in fine-grained micritic limestone blocks are up to 2 orders of magnitude higher than the average rates estimated for coarse-grained limestone blocks at the same site. In addition, in experiments that use atomic force microscopy to image dissolving micritic limestone, we show that these higher reaction rates could be due to rapid dissolution along micron-scale grain boundaries, followed by mechanical detachment of tiny particles from the surface. Our analysis indicates that micron-scale grain detachment, rather than pure chemical dissolution, could be the dominant erosional mode for fine-grained rocks in many carbonate terrains.

  16. Detachment-induced electron production in the early afterglow of pulsed cc-rf oxygen plasmas

    SciTech Connect

    Kuellig, C.; Dittmann, K.; Meichsner, J.

    2012-07-15

    Line integrated electron densities are measured by 160.28 GHz Gaussian beam microwave interferometry in a 10 Hz pulsed (50% duty cycle) cc-rf oxygen discharge, operating at 13.56 MHz. Depending on the processing parameters, the oxygen rf discharge displays two different operation modes regarding its electronegativity. For higher rf power with negative self-bias voltage above -220 V, the oxygen discharge acts as electropositive plasma (n{sub -}/n{sub e} Much-Less-Than 1), whereas at lower rf power and self-bias voltage the plasma becomes strongly electronegative (n{sub -}/n{sub e}>2). In the latter mode, a significant electron density increase is measured in the early afterglow (<100 {mu}s) within a pressure range from 20 to 100 Pa. By use of a simple rate equation model, the temporal behavior of the electron density could be reproduced for both modes of electronegativity. The electron production in the early afterglow is mainly caused due to the detachment of negative atomic oxygen ions by metastable oxygen molecules.

  17. The Plankogel detachment of the Eastern Alps: petrological evidence for an orogen-scale extraction fault

    NASA Astrophysics Data System (ADS)

    Schorn, Simon; Stüwe, Kurt

    2016-04-01

    The so-called Plankogel detachment is an east-west trending, south-dipping low-angle structure that juxtaposes the high-pressure rocks of the eclogite type locality of the eastern European Alps against amphibolite facies rocks to the south. It occurs in both the Saualpe and Koralpe Complex in eastern Austria. During Cretaceous intracontinental subduction, the footwall and the hangingwall units of the Plankogel detachment were buried to different crustal levels as inferred by pseudosection modelling and conventional thermobarometry: ~23-24 kbar and 640-690 °C for the eclogite facies units in the footwall of the detachment and ~12-14 kbar and 550-580 °C for the amphibolite facies metapelites in the hangingwall. Despite the different peak metamorphic conditions, both sides of the detachment display a common overprint at conditions around 10 kbar and 580-650 °C. From this, we infer a two-stage exhumation process and suggest that this two stage process is best interpreted tectonically in terms of slab extraction during Eoalpine subduction. The first stage of exhumation occurred due to the downward (southward) extraction of a lithospheric slab that was localized in the trace of the Plankogel detachment. The later stage, however, is attributed to more regional erosion- or extension-driven processes. Since the Plankogel detachment is geometrically related to a crustal-scale shear zone further north (the Plattengneiss shear zone), we suggest that both structures are part of the same extraction fault system along which the syn-collisional exhumation of the Eoalpine high-pressure units of the Eastern Alps occurred. The suggested model is consistent with both the mylonitic texture of the Plattengneiss shear zone and the overall ambiguous shear sense indicators present in the entire region.

  18. ``Detached'' deep earthquakes: are they really?

    NASA Astrophysics Data System (ADS)

    Okal, Emile A.

    2001-12-01

    We use primarily the generation of acoustic T waves into the ocean by deep seismic sources to investigate the propagation of high-frequency seismic energy from the bottom of subduction zones to the shoreline at the earth's surface. Conversion from shear waves to oceanic acoustic waves can be used as a proxy for the existence of a continuous slab featuring low anelastic attenuation. With the help of other techniques, such as the estimation of Q from S-to- P spectral amplitude ratios, we examine systematically a number of regions where earthquakes have been described as "detached". We establish the mechanical continuity of the slab to the hypocenters of the 1990 Sakhalin and 1982 Bonin events, which occurred several hundred kilometers in front of the mainstream seismic zone. The study of the 1989 Paraguay shock is inconclusive, probably due to its much smaller size. The vertical continuity of the South American slab through its aseismic depth range is verified, and a similar situation probably exists in Java. Attenuation data suggests that the deep Spanish earthquakes occur within a vertically large segment of colder material, and a similar situation may exist in Colombia. The only clearly detached deep events with no mechanical connection to the surface make up the Vityaz cluster, under the North Fiji Basin. Based on a variety of geophysical evidence, the small deep earthquakes under New Zealand are likely to take place in a detached blob at least 350 km below the termination of mainstream seismicity. These results support a model integrating buoyancy forces over a long continuous slab as the source of the down-dip compressional stresses observed in large earthquakes at the bottom of the transition zone.

  19. Near-threshold photoionization of hydrogenlike uranium studied in ion-atom collisions via the time-reversed process.

    PubMed

    Stöhlker, T; Ma, X; Ludziejewski, T; Beyer, H F; Bosch, F; Brinzanescu, O; Dunford, R W; Eichler, J; Hagmann, S; Ichihara, A; Kozhuharov, C; Krämer, A; Liesen, D; Mokler, P H; Stachura, Z; Swiat, P; Warczak, A

    2001-02-05

    Radiative electron capture, the time-reversed photoionization process occurring in ion-atom collisions, provides presently the only access to photoionization studies for very highly charged ions. By applying the deceleration mode of the ESR storage ring, we studied this process in low-energy collisions of bare uranium ions with low- Z target atoms. This technique allows us to extend the current information about photoionization to much lower energies than those accessible for neutral heavy elements in the direct reaction channel. The results prove that for high- Z systems, higher-order multipole contributions and magnetic corrections persist even at energies close to the threshold.

  20. A process for separating acid-sugar mixtures using ion exclusion chromatography

    SciTech Connect

    Hester, R.D.; Hartfield, S.W.; Farina, G.E.

    1994-10-01

    Work using a low-temperature concentrated sulfuric acid hydrolysis process to convert the cellulosic fraction of corn stover to monomeric sugars demonstrated the high conversion efficiencies possible with that process. The TVA work also confirmed the need for a cost-effective acid-sugar separation process. A preparative-scale ion-exclusion chromatography (IEC) system was designed, constructed, and tested with a variety of synthetic solutions and actual hydrolyzates. Although significant dispersion was observed initially, design changes were effective in minimizing this phenomenon. Data collected during the operation of the preparative-scale system were used in the design and construction of an IEC miniplant capable of processing larger volumes of synthetic solutions or hydrolyzates and in the design of an extraction-assisted IEC system. The data were also used to assess the viability of a continuous feed IEC system. This paper includes a discussion of the IEC process, provides overall material balances for various IEC process scenarios, and presents a discussion on process economics.

  1. Mediterranean detachment zones : thermicity vs heritage.

    NASA Astrophysics Data System (ADS)

    Labrousse, Loic; Huet, Benjamin; Le Pourhiet, Laetitia; Jolivet, Laurent; Burov, Evgenii

    2017-04-01

    Even if the seminal comprehensive descriptions of Metamorphic Core Complexes (MCCs) in the American Cordillera mentionned lower plates constituted of gneiss and intruded by granites (e. g. Snake Range, Whipple Mountains), the actual definition of MCCs : « Cordilleran metamorphic core complexes appear to be bodies from the middle crust that have been dragged out from beneath fracturing and extending upper crustal rocks, and exposed beneath shallow-dipping (normal slip) faults of large areal extent » {as in Lister & Davis, 1989, Journal of Structural Geology, v. 11, pp. 65-94} refers to rocks exhumed from the middle crust whatever their thermal history. The fundamental property of this middle crust resides in its ability fo flow lateraly toward the forming dome, to accommodate stretching of the upper plate and preserve a relatively flat moho. Even though thermal reequilibration can induce weakening of the lower crust, a similar strength profile can also be inherited from pre-extension evolution of the continental crust and promote development of the original structure of MCCs : their detachment. In order to unravel the rheological meaning of detachments, we propose here a review of extensional shear zones described as detachments in the Mediterranean realm, and establish a three end-members typology with « hot MCCs » as one end-member, and two cold MCC end-members with a weak middle crust due to stacking of high pressure metapelitic nappes or a strong upper crust responsible for the strength contrast exaggeration between the upper and lower crust. New fully coupled thermo-mechanical modeling experiments together with a review of comparable published results allow to test this three end-member typology and determine the critical strength constrast for the perennial development of a detachment zone. A 1000 ratio between the strength at the brittle-ductile transition and the strength at the base of the crust seems a boundary value between localized extensional modes

  2. Plasma Detachment Mechanisms in Propulsive Magnetic Nozzles

    DTIC Science & Technology

    2013-03-07

    Merino and E. Ahedo, Physics of Plasmas 20, 023502 (2013). 26E. Ahedo, J. Gallardo , and M. Mart́ınez-Sánchez, Physics of Plasmas 10, 3397 (2003...Wiley-Blackwell, 2005. 11Ahedo, E., Gallardo , J., and Mart́ınez-Sánchez, M., “Effects of the radial-plasma wall interaction on the axial Hall...detachment References [1] Ahedo, E., Gallardo , J. M., & Mart́ınez-Sánchez, M. (2003). Effects of the radial-plasma wall interaction on the axial Hall

  3. Hydrogeochemical processes controlling changes in fluoride ion concentration within alluvial and hard rock aquifers in a part of a semi-arid region of Northern India

    NASA Astrophysics Data System (ADS)

    Singh, Priyadarshini; Ashthana, Harshita; Rena, Vikas; Kumar, Pardeep; Mukherjee, Saumitra

    2017-04-01

    Geochemical signatures from alluvial and hard rock aquifers in a part of Northern India elucidate the chemical processes controlling fluctuations in fluoride ion concentration linked to changes in major ion groundwater chemistry. Majority of samples from the hard rock and the alluvial aquifers for pre-monsoon show both carbonate and silicate weathering, ion exchange, evaporation and rock water interaction as the processes controlling major ion chemistry whereas for post monsoon samples, contribution of silicate weathering and ion exchange process were observed. Evaporative processes causing the increase in Na+ ion concentration in premonsoon enhance the reverse ion exchange processes causing increase in Ca2+ ions which impedes fluorite mineral dissolution in the premonsoon groundwater samples within the study area. Alternately, it is observed that the removal of Ca2+ ion from solution plays a key role in increase in fluorite mineral dissolution despite its saturation in groundwater in the postmonsoon samples. Also, ion exchange process on clay surfaces is more pronounced in the postmonsoon samples leading to the uptake of Ca2+ ion upon release of Na+ and K+ ion in solution. Ca2+ ion concentration is inversely correlated with F- ion concentration in both the aquifers in the postmonsoon season validating the role of calcite precipitation as a major reason for the fluoride ion increase. Moreover, increase in silicate weathering in the postmonsoon samples leads to increase in clay particles acting as suitable sites for ion exchange enhancing Ca2+ removal from groundwater. Cationic dominance of Na+ ion in the post monsoon samples also validates the occurrence of this process. Collectively, these processes set the ideal conditions for increase in the fluoride ion concentration particularly in the alluvium aquifer waters in the postmonsoon season Keywords: geochemistry, ion-exchange, rock-water interaction, mineral dissolution, weathering.

  4. Detached Bridgman Growth of Germanium and Germanium-Silicon Alloy Crystals

    NASA Technical Reports Server (NTRS)

    Szofran, F. R.; Volz, M. P.; Schweizer, M.; Kaiser, N.; Cobb, S. D.; Motakef, S.; Vujisic, L. J.; Croell, A.; Dold, P.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Earth based experiments on the science of detached crystal growth are being conducted on germanium and germanium-silicon alloys (2at% Si average composition) in preparation for a series of experiments aboard the International Space Station (ISS) to differentiate among proposed mechanisms contributing to detachment. Sessile drop measurements were first carried out for a large number of substrates made of potential ampoule materials to determine the contact angles and the surface tension as a function of temperature and composition. The process atmosphere and duration of the experiment (for some cases) were also found to have significant influence on the wetting angle. Growth experiments have used pyrolytic boron nitride (pBN) and fused silica ampoules with the majority of the detached results occurring predictably in the pBN. The contact angles were 173 deg (Ge) and 165 deg (GeSi) for pBN. For fused silica, the contact angle decreases to an equilibrium value with duration of measurement ranging from 150 to 117 deg (Ge), 129 to 100 deg (GeSi). Forming gas (Ar + 2% H2) and vacuum have been used in the growth ampoules. With gas in the ampoule, a variation of the temperature profile during growth has been used to control the pressure difference between the top of the melt and the volume below the melt caused by detachment of the growing crystal. The stability of detachment has been modeled and substantial insight has been gained into the reasons that detachment has most often been observed in reduced gravity but nonetheless has occurred randomly even there. An empirical model for the conditions necessary to achieve sufficient stability to maintain detached growth for extended periods has been developed and will be presented. Methods for determining the nature and extent of detachment include profilometry and optical and electron microscopy. This surface study is the subject of another presentation at this Congress. Results in this presentation will show that we have

  5. Estradiol Uptake in a Combined Magnetic Ion Exchange - Ultrafiltration (MIEX-UF) Process During Water Treatment.

    PubMed

    Imbrogno, Alessandra; Biscarat, Jennifer; Schafer, Andrea Iris

    2017-01-01

    Estrogens and their synthetic analogues are widely used as pharmaceuticals. Upon oral administration these drugs are eventually excreted via urine. The persistence of these pharmaceuticals and inefficient removal by water treatment lead to accumulation in surface water and effluents with negative effects for aquatic life and human health. In this study, the uptake of estradiol by a combined magnetic ion exchange resin - ultrafiltration process (MIEX-UF) was investigated. This is a relatively common process used in drinking water treatment for the removal of natural organic matter. However, uptake of micropollutants, such as steroidal pharmaceuticals, may occur as a side effect of water treatment due to the high affinity for polymeric materials. To elucidate the mechanism governing estradiol partitioning between water, resin and membrane, the influence of different parameters, such as pH, humic acid concentration and membrane molecular-weight-cut-off (MWCO) was studied. Humic acid concentration and pH affected estradiol uptake most. At pH 11 the most significant increase of estradiol uptake was observed for MIEX-UF process (30 ng/g corresponding to 80%) compared with individual UF (17 ng/g corresponding to 12%). The presence of humic acid slightly reduced estradiol uptake at pH 11 (about 55%) due to competition for the ion exchange binding sites. Results demonstrated that the uptake of estradiol, which is amongst the most potent EDCs detected in surface water, in the MIEX-UF process can reach significant quantities (30 ng/g of resin) leading to uncontrolled accumulation of this micropollutant during drinking water treatment. This study gives a novel contribution in the understanding the mechanism of the unanticipated accumulation of pharmaceuticals, such as estradiol, in the drinking water treatment process. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. Receptor-mediated cell attachment and detachment kinetics. II. Experimental model studies with the radial-flow detachment assay.

    PubMed Central

    Cozens-Roberts, C; Quinn, J A; Lauffenburger, D A

    1990-01-01

    Quantitative information regarding the kinetics of receptor-mediated cell adhesion to a ligand-coated surface are crucial for understanding the role of certain key parameters in many physiological and biotechnology-related processes. Here, we use the probabilistic attachment and detachment models developed in the preceding paper to interpret transient data from well-defined experiments. These data are obtained with a simple model cell system that consists of receptor-coated latex beads (prototype cells) and a Radial-Flow Detachment Assay (RFDA) using a ligand-coated glass disc. The receptors and ligands used in this work are complementary antibodies. The beads enable us to examine transient behavior with particles that possess fairly uniform properties that can be varied systematically, and the RFDA is designed for direct observation of adhesion to the ligand-coated glass surface over a range of shear stresses. Our experiments focus on the effects of surface shear stress, receptor density, and ligand density. These data provide a crucial test of the probabilistic framework. We show that these data can be explained with the probabilistic analyses, whereas they cannot be readily interpreted on the basis of a deterministic analysis. In addition, we examine transient data on cell adhesion reported from other assays, demonstrating the consistency of these data with the predictions of the probabilistic models. Images FIGURE 2 PMID:2174272

  7. Characterization of focused ion beam induced processes (etching and metal deposition)

    SciTech Connect

    Gandhi, A.

    1991-01-01

    Significant gains have been made in recent years in deployment of focused ion beams (FIBs) for submicron surface-topology modification. As the scope and complexity of this technology increases, a need has arisen to understand and characterize the phenomena responsible for metal deposition and etching using FIBs. To facilitate such characterization, a parametric model was developed by analyzing the relationship between the various input and output quantities. Etch rate and deposition rate are the primary output variables while the independent or adjustable variables are gas flux, scanning speed, and temperature. The process parameters, derived from the best fit between the data and the model, provide a test basis for evaluation of surface mechanisms. Additionally, the model is used to optimize the process to efficiently manipulate the desired outputs (for instance, deposition rate, etch rate, saturation factor, etc.). A key aspect of the accurate modeling procedure used here is what is called the spiked (current) delivery approach where the instantaneous value as opposed to the time-averaged value of the ion-flux impact on the target is considered.

  8. An ion-beam-assisted process for high-T{sub c} Josephson junctions

    SciTech Connect

    Huang, M.Q.; Chen, L.; Zhao, Z.X.; Yang, T.; Nie, J.C.; Wu, P.J.; Xiong, X.M.

    1997-10-01

    We have developed a non-ion-etching ion-beam-assisted-deposition (IBAD) process for fabricating high critical-temperature (T{sub c}) grain boundary Josephson junctions through a photoresist liftoff mask. The YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) junctions fabricated through this process exhibited the resistively-shunted-junction (RSJ)-like I{endash}V characteristics. The well-defined Shapiro steps have been seen on the I{endash}V curves under microwave radiation. The magnetic modulation of critical current of a 4 {mu}m width YBCO junction tallied with the prior simulated Fraunhofer diffraction pattern of a Josephson junction with a spatially homogeneous critical current density. The maximum peak-to-peak modulation voltage across the dc superconducting quantum interference device (SQUID) fabricated by using these junctions reached up to 32 {mu}V at 77 K. The magnetic modulation of the SQUID exhibited periodic behavior with the observed modulation period of 5.0{times}10{sup {minus}4}G. {copyright} {ital 1997 American Institute of Physics.}

  9. In-situ monitoring of plasma ion assisted deposition (PIAD) processes

    NASA Astrophysics Data System (ADS)

    Harhausen, Jens; Foest, Rüdiger; Loffhagen, Detlef

    2015-09-01

    Present photonics applications depend on accurate production techniques. Plasma based processes might be termed the backbone of multilayer optical coatings which are the key components of dielectric mirrors, filters or antireflectives. However, the sector strongly relies on process recipies based on empirical optimization of thin film properties. Limitations in quality, repeatability and yield are faced. In this contribution results of efforts on plasma characterization of a beam source employed for PIAD are presented. Data on electron and ion kinetics as well as optical emission facilitated a comprehensive understanding of underlying physics of ion beam generation and propagation in an industrial type batch coater. In order to promote the development of next generation production plants, concepts for in-situ diagnostics are investigated. Results from monitoring of optical radiance of the plasma plume near the source and electron density near the substrates are discussed. The novel concept of the multipole resonance probe is applied during deposition in order to trace variations not only in magnitude of plasma density, but also its spatial distribution. Coating materials comprise TiO2, Ta2O5, Al2O3 and SiO2. Funded by the German Federal Ministry of Education and Research (BMBF) under Grant 13N13213).

  10. An Improved Process for Precipitating Cyanide Ions from the Barren Solution at Different pHs

    NASA Astrophysics Data System (ADS)

    Figueroa, Gabriela V.; Parga, José R.; Valenzuela, Jesus L.; Vázquez, Victor; Valenzuela, Alejandro; Rodriguez, Mario

    2016-02-01

    In recent decades, the use of metal sulfides instead of hydroxide precipitation in hydrometallurgical processes has gained prominence. Some arguments for its preferential use are as follows: a high degree of metal removal at relatively low pH values, the sparingly soluble nature of sulfide precipitates, favorable dewatering characteristics, and the stability of the formed metal sulfides. The Merrill-Crowe zinc-precipitation process has been applied worldwide in a large number of operations for the recovery of gold and silver from cyanide solutions. However, in some larger plants, the quality of this precious precipitate is low because copper, zinc and especially lead are precipitated along with gold and silver. This results in higher consumption of zinc dust and flux during the smelting of the precipitate, the formation of the matte, and a shorter crucible life. The results show that pH has a significant effect on the removal efficiency of zinc and copper cyanide ions. The optimal pH range was determined to be 3-4, and the removal efficiency of zinc and copper cyanide ions was up to 99%.

  11. Properties of ion implanted Ti-6Al-4V processed using beamline and PSII techniques

    SciTech Connect

    Walter, K.C.; Woodring, J.S.; Nastasi, M.; Munson, C.M.; Williams, J.M.; Poker, D.B.

    1996-12-31

    The surface of Ti-6Al-4V (Ti64) alloy has been modified using beamline implantation of boron. In separate experiments, Ti64 has been implanted with nitrogen using a plasma source ion implantation (PSII) technique utilizing either ammonia (NH{sub 3}), nitrogen (N{sub 2}), or their combinations as the source of nitrogen ions. Beamline experiments have shown the hardness of the N-implanted surface saturates at a dose level of {approximately} 4 {times} 10{sup 17} at/cm{sup 2} at {approximately} 10 GPa. The present work makes comparisons of hardness and tribological tests of (1) B implantation using beamline techniques, and (2) N implanted samples using ammonia and/or nitrogen gas in a PSII process. The results show that PSII using N{sub 2} or NH{sub 3} gives similar hardness as N implantation using a beamline process. The presence of H in the Ti alloy surface does not affect the hardness of the implanted surface. Boron implantation increased the surface hardness by as much as 2.5x at the highest dose level. Wear testing by a pin-on-disk method indicated that nitrogen implantation reduced the wear rate by as much as 120x, and boron implantation reduced the wear rate by 6.5x. Increased wear resistance was accompanied by a decreased coefficient of friction.

  12. Application of the hybrid complexation-ultrafiltration process for metal ion removal from aqueous solutions.

    PubMed

    Zeng, Jianxian; Ye, Hongqi; Hu, Zhongyu

    2009-01-30

    Complexation-ultrafiltration process was investigated for mercury and cadmium removal from aqueous solutions by using poly(acrylic acid) sodium salt (PAASS) as a complexing agent. The kinetics of complexation reactions of PAASS with the metal ions were studied under a large excess PAASS and pH 5.5. It takes 25 and 50 min for mercury and cadmium to get the complexation equilibrium, respectively, and the reaction kinetics can be described by a pseudo-first-order equation. Effects of various operating parameters such as loading ratios, pH values, etc. on metal rejection coefficients (R) were investigated. In the process of concentration, membrane fluxes decline slowly and R values are about 1. The concentrated retentates were used further for the decomplexation. The decomplexation ratio of mercury-PAASS complex is about 30%, whereas that of cadmium-PAASS complex reaches 93.5%. After the decomplexation, diafiltration experiments were carried out at pH 2.5. Cadmium can be diafiltrated satisfactorily from the retentate, but for mercury it is the contrary. Selective separation of the both metal ions was studied from a binary solution at pH 5. When mercury, cadmium and PAASS concentrations are 30, 30 and 40 mg L(-1), respectively, mercury is retained by ultrafiltration while almost all cadmium passes through the membrane.

  13. Recycling of spent lithium-ion battery with polyvinyl chloride by mechanochemical process.

    PubMed

    Wang, Meng-Meng; Zhang, Cong-Cong; Zhang, Fu-Shen

    2017-09-01

    In the present study, cathode materials (C/LiCoO2) of spent lithium-ion batteries (LIBs) and waste polyvinyl chloride (PVC) were co-processed via an innovative mechanochemical method, i.e. LiCoO2/PVC/Fe was co-grinded followed by water-leaching. This procedure generated recoverable LiCl from Li by the dechlorination of PVC and also generated magnetic CoFe4O6 from Co. The effects of different additives (e.g. alkali metals, non-metal oxides, and zero-valent metals) on (i) the conversion rates of Li and Co and (ii) the dechlorination rate of PVC were investigated, and the reaction mechanisms were explored. It was found that the chlorine atoms in PVC were mechanochemically transformed into chloride ions that bound to the Li in LiCoO2 to form LiCl. This resulted in reorganization of the Co and Fe crystals to form the magnetic material CoFe4O6. This study provides a more environmentally-friendly, economical, and straightforward approach for the recycling of spent LIBs and waste PVC compared to traditional processes. Copyright © 2017. Published by Elsevier Ltd.

  14. Kinematic evidence for downdip movement on the Mormon Peak detachment

    NASA Astrophysics Data System (ADS)

    Walker, Christopher D.; Anders, Mark H.; Christie-Blick, Nicholas

    2007-03-01

    The Mormon Peak detachment is considered to be one of the best examples of a rooted upper crustal detachment fault that propagated through the brittle crust at a low angle. The hanging wall of the detachment today consists of a number of isolated blocks that have been interpreted as remnants of a once-contiguous extensional allochthon. Here we present the results of a new study of directional indicators from the basal surfaces beneath these blocks. These measurements do not agree with the long-standing interpretation of a S75°W movement direction for the detachment hanging wall. Instead, the most recent movement on each section of the detachment took place approximately parallel to the present downdip direction. We conclude that the Mormon Peak detachment is best explained as the basal surfaces to a series of rootless gravity slides.

  15. Effect of lanthanum ions (La3+) on ferritin-regulated antioxidant process under PEG stress.

    PubMed

    Zhang, Lijing; Yang, Tongwen; Gao, Yongsheng; Liu, Yubing; Zhang, Tengguo; Xu, Shijian; Zeng, Fuli; An, Lizhe

    2006-11-01

    The physiological effects of lanthanum(III) ions on the ferritin-regulated antioxidant process were studied in wheat (Triticum aestivum L.) seedlings under polyethylene glycol (PEG) stress. Treatment with 0.1 mM La3+ resulted in increased levels of chlorophyll, carotenoid, proline, ascorbate, and reduced glutathione. The activities of superoxide dismutase, catalase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase, and peroxidase were also increased after La3+ treatment. Treatment with La3+ seems to enhance the capacity of the reactive oxygen species scavenging system, affect the Fe2+ and Fe3+ electron-transfer process in ferritin, and restrain the formation of hydroxyl radical (OH.), alleviating the oxidative damage induced by PEG stress.

  16. Bifunctional phenyl monophosphonic/sulfonic acid ion exchange resin and process for using the same

    DOEpatents

    Alexandratos, Spiro; Shelley, Christopher A.; Horwitz, E. Philip; Chiarizia, Renato

    2001-01-01

    A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

  17. Bifunctional phenyl monophosphonic/sulfonic acid ion exchange resin and process for using the same

    DOEpatents

    Alexandratos, Spiro; Shelley, Christopher A.; Horwitz, E. Philip; Chiarizia, Renato; Gula, Michael J.; Xue, Sui; Harvey, James T.

    2002-01-01

    A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

  18. Nanometer-scale mapping of irreversible electrochemical nucleation processes on solid Li-ion electrolytes.

    PubMed

    Kumar, Amit; Arruda, Thomas M; Tselev, Alexander; Ivanov, Ilia N; Lawton, Jamie S; Zawodzinski, Thomas A; Butyaev, Oleg; Zayats, Sergey; Jesse, Stephen; Kalinin, Sergei V

    2013-01-01

    Electrochemical processes associated with changes in structure, connectivity or composition typically proceed via new phase nucleation with subsequent growth of nuclei. Understanding and controlling reactions requires the elucidation and control of nucleation mechanisms. However, factors controlling nucleation kinetics, including the interplay between local mechanical conditions, microstructure and local ionic profile remain inaccessible. Furthermore, the tendency of current probing techniques to interfere with the original microstructure prevents a systematic evaluation of the correlation between the microstructure and local electrochemical reactivity. In this work, the spatial variability of irreversible nucleation processes of Li on a Li-ion conductive glass-ceramics surface is studied with ~30 nm resolution. An increased nucleation rate at the boundaries between the crystalline AlPO4 phase and amorphous matrix is observed and attributed to Li segregation. This study opens a pathway for probing mechanisms at the level of single structural defects and elucidation of electrochemical activities in nanoscale volumes.

  19. Redox processes at surfaces of manganese oxide and their effects on aqueous metal ions

    USGS Publications Warehouse

    Hem, J.D.

    1978-01-01

    Mn oxides precipitated from aerated solutions of Mn2+ by raising the pH are reported in various publications to have the approximate composition Mn3O4 or MnOOH. These oxyhydroxides in turn can disproportionate to Mn2+ and MnO2 resulting in a substantial decrease in equilibrium Mn solubility. The disproportionation can catalyze the oxidation of Mn2+ and other metals by facilitating electron-transfer processes. Diversion of some electron transfers from Mn species to other metal ions can greatly decrease the equilibrium solubility of Co, Pb, Ni and some other elements in the presence of mixed-valence Mn oxides. Some scavenging and coprecipitation effects involving Mn oxides may be attributable to redox processes. Equilibrium solubilities for Mn, Co and Pb are summarized in four graphs. ?? 1978.

  20. Low pressure electrospray ionization system and process for effective transmission of ions

    DOEpatents

    Tang, Keqi [Richland, WA; Page, Jason S [Kennewick, WA; Kelly, Ryan T [Wet Richland, WA; Smith, Richard D [Richland, WA

    2010-03-02

    A system and method are disclosed that provide up to complete transmission of ions between coupled stages with low effective ion losses. A novel "interfaceless" electrospray ionization system is further described that operates the electrospray at a reduced pressure such that standard electrospray sample solutions can be directly sprayed into an electrodynamic ion funnel which provides ion focusing and transmission of ions into a mass analyzer.

  1. Meniscus Shapes in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K

    2010-01-01

    In detached Bridgman crystal growth, most of the melt is in contact with the ampoule wall, but the crystal is separated from the wall by a small gap, typically 1-100 micrometers. A liquid free surface, or meniscus, bridges across this gap at the position of the melt-crystal interface. Meniscus shapes have been calculated for the case of detached Bridgman growth in cylindrical ampoules by solving the Young-Laplace equation. Key parameters affecting meniscus shapes are the growth angle, contact angle of the meniscus to the ampoule wall, the pressure differential across the meniscus, and the Bond number, a measure of the ratio of gravitational to capillary forces. In general, for specified values of growth and contact angles, solutions exist only over a finite range of pressure differentials. For intermediate values of the Bond number, there are multiple solutions to the Young-Laplace equations. There are also cases where, as a function of pressure differential, existence intervals alternate with intervals where no solutions exist. The implications of the meniscus shape calculations on meniscus stability are discussed.

  2. Management of Giant Retinal Tear Detachments

    PubMed Central

    Berrocal, Maria H.; Chenworth, Megan L.; Acaba, Luis A.

    2017-01-01

    Giant retinal tears (GRTs) are full-thickness circumferential tears of more than 90 degrees of the retina that are associated with vitreous detachment. They are related to ocular trauma, high myopia, aphakia, pseudophakia, genetic mutations involving collagen and young age. GRTs comprise 1.5% of all rhegmatogenous retinal detachments and the average age of incidence is 42 years. GRTs are more common in males, as 72% of all cases occur in males. The incidence of GRTs in the general population is estimated to be 0.05 per 100,000 individuals. Common techniques used in the management of GRTs include fluid-air exchange, pneumatic retinopexy, scleral buckling, primary vitrectomy with gas or silicone oil tamponade, and combined scleral buckle-vitrectomies. However, management of GRTs poses a great challenge to physicians due to the high risk of intra- and post-operative complications and the many technical difficulties involved. The advent of perfluorocarbon liquids (PFCL) and the use of micro-incisional surgery for the treatment of GRTs has provided new opportunities for the management of GTRs. Today, retinal reattachment can be achieved in 94-100% of cases. PMID:28299011

  3. A Sensitivity Analysis of SOLPS Plasma Detachment

    NASA Astrophysics Data System (ADS)

    Green, D. L.; Canik, J. M.; Eldon, D.; Meneghini, O.; AToM SciDAC Collaboration

    2016-10-01

    Predicting the scrape off layer plasma conditions required for the ITER plasma to achieve detachment is an important issue when considering divertor heat load management options that are compatible with desired core plasma operational scenarios. Given the complexity of the scrape off layer, such predictions often rely on an integrated model of plasma transport with many free parameters. However, the sensitivity of any given prediction to the choices made by the modeler is often overlooked due to the logistical difficulties in completing such a study. Here we utilize an OMFIT workflow to enable a sensitivity analysis of the midplane density at which detachment occurs within the SOLPS model. The workflow leverages the TaskFarmer technology developed at NERSC to launch many instances of the SOLPS integrated model in parallel to probe the high dimensional parameter space of SOLPS inputs. We examine both predictive and interpretive models where the plasma diffusion coefficients are chosen to match an empirical scaling for divertor heat flux width or experimental profiles respectively. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility, and is supported under Contracts DE-AC02-05CH11231, DE-AC05-00OR22725 and DE-SC0012656.

  4. The ironic detachment of Edward Gibbon.

    PubMed

    Trosman, Harry

    2009-06-01

    Edward Gibbon, the author of The History of the Decline and Fall of the Roman Empire, has been widely recognized as a master of irony. The historian's early life with parents he found self-serving and unreliable, his reaction to the events surrounding the death of his mother at the age of 9 and the decline of his father, left an impact on his personality and played a role in determining his choice of his life work. Irony has been approached from a psychoanalytic perspective as a mode of communication, as a stylistic device, as a modality through which one might view reality and as a way of uncovering the linkage between pretense and aspiration, between the apparent and the real. Gibbon's ironic detachment can be understood as rooted in his life history. He felt detached from his family of origin, in need of a protective device which would enable him to deal with passion. Sexual and aggressive impulses mobilized defensive postures that were later transformed into an attitude of skepticism and an interest in undercutting false beliefs and irrational authority, positions he attributes to religious ideation which served to instigate historical decline.

  5. Photometric orbits of seven detached eclipsing binaries

    NASA Astrophysics Data System (ADS)

    Popper, D. M.; Etzel, P. B.

    1981-01-01

    Photoelectric light curves of the detached eclipsing binaries V805 Aql, TV Cet, MY Cyg, V478 Cyg, V1143 Cyg, BS Dra, and BK Peg are analyzed. The systems are among those with good spectrographic orbits of both components that are in need of good photometric solutions in order to obtain the absolute properties of the components. The analyses are carried out with a computer program valid for detached systems of spherical or slightly oblate stars in orbits of arbitrary eccentricity. A range of solutions much greater than implied by the internal mean errors of the parameters, is found to give satisfactory fits to the observations. Some of the fits are displayed for a variety of solutions for each system. For the three systems with measurable light variation between eclipses - V478 Cyg, V805 Aql, and MY Cyg - the effect of reflection appears to be substantially less than predicted. Very small, but nonzero, orbital eccentricities are found for four of the systems. The variations of limb darkening with wavelength and with spectral type are found to be in reasonable agreement with predictions from atmospheric theory.

  6. Responses of hydrochemical inorganic ions in the rainfall-runoff processes of the experimental catchments and its significance for tracing

    USGS Publications Warehouse

    Gu, W.-Z.; Lu, J.-J.; Zhao, X.; Peters, N.E.

    2007-01-01

    Aimed at the rainfall-runoff tracing using inorganic ions, the experimental study is conducted in the Chuzhou Hydrology Laboratory with special designed experimental catchments, lysimeters, etc. The various runoff components including the surface runoff, interflow from the unsaturated zone and the groundwater flow from saturated zone were monitored hydrometrically. Hydrochemical inorganic ions including Na+, K+, Ca2+, Mg2+, Cl-, SO42-, HCO3- + CO32-, NO3-, F-, NH4-, PO42-, SiO2 and, pH, EC, 18O were measured within a one month period for all processes of rainfall, various runoff components and groundwater within the catchment from 17 boreholes distributed in the Hydrohill Catchment, few soil water samples were also included. The results show that: (a) all the runoff components are distinctly identifiable from both the relationships of Ca2+ versus Cl-/SO42-, EC versus Na+/(Na+ + Ca2+) and, from most inorganic ions individually; (b) the variation of inorganic ions in surface runoff is the biggest than that in other flow components; (c) most ions has its lowermost concentration in rainfall process but it increases as the generation depths of runoff components increased; (d) quantitatively, ion processes of rainfall and groundwater flow display as two end members of that of other runoff components; and (e) the 18O processes of rainfall and runoff components show some correlation with that of inorganic ions. The results also show that the rainfall input is not always the main source of inorganic ions of various runoff outputs due to the process of infiltration and dissolution resulted from the pre-event processes. The amount and sources of Cl- of runoff components with various generation mechanisms challenge the current method of groundwater recharge estimation using Cl-.

  7. Papers presented to the Conference on Heat and Detachment in Crustal Extension on Continents and Planets

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Several topics relative to heat and detachment in crustal extension on continents and planets are discussed. Rifting on Venus, heat flow and continental breakup, magnetism, the mountains and tectonic processes of Io, and the ductile extension of planetary lithospheres are among the topics covered.

  8. Detection of detachments and inhomogeneities in frescos by Compton scattering

    NASA Astrophysics Data System (ADS)

    Castellano, A.; Cesareo, R.; Buccolieri, G.; Donativi, M.; Palamà, F.; Quarta, S.; De Nunzio, G.; Brunetti, A.; Marabelli, M.; Santamaria, U.

    2005-07-01

    A mobile instrument has been developed for the detection and mapping of detachments in frescos by using Compton back scattered photons. The instrument is mainly composed of a high energy X-ray tube, an X-ray detection system and a translation table. The instrument was first applied to samples simulating various detachment situations, and then transferred to the Vatican Museum to detect detachments and inhomogeneities in the stanza di Eliodoro, one of the "Raphael's stanze".

  9. Detachments of the retinal pigment epithelium at the posterior pole.

    PubMed

    Noble, K G; Levitzky, M J; Carr, R E

    1976-08-01

    Multiple vitelliform cysts of the retina, a disorder of unknown cause in which there are multiple detachments of the retinal pigment epithelium at the posterior pole, occurred in five patients. In four patients all lesions were located outside the parafoveal area while one patient showed bilateral foveal elevations associated with more eccentric detachments. Several patients showed slow resolution of some of the detachments with mild disturbances of the pigment epithelium.

  10. Structural analysis of how podocytes detach from the glomerular basement membrane under hypertrophic stress.

    PubMed

    Kriz, Wilhelm; Hähnel, Brunhilde; Hosser, Hiltraud; Rösener, Sigrid; Waldherr, Rüdiger

    2014-01-01

    Podocytes are lost by detachment from the GBM as viable cells; details are largely unknown. We studied this process in the rat after growth stimulation with FGF-2. Endothelial and mesangial cells responded by hyperplasia, podocytes underwent hypertrophy, but, in the long run, developed various changes that could either be interpreted showing progressing stages in detachment from the GBM or stages leading to a tighter attachment by foot process effacement (FPE). This occurred in microdomains within the same podocyte; thus, features of detachment and of reinforced attachment may simultaneously be found in the same podocyte. (1) Initially, hypertrophied podocytes underwent cell body attenuation and formed large pseudocysts, i.e., expansions of the subpodocyte space. (2) Podocytes entered the process of FPE starting with the retraction of foot processes (FPs) and the replacement of the slit diaphragm by occluding junctions, thereby sealing the filtration slits. Successful completion of this process led to broad attachments of podocyte cell bodies to the GBM. (3) Failure of sealing the slits led to gaps of varying width between retracting FPs facilitating the outflow of the filtrate from the GBM. (4) Since those gaps are frequently overarched by broadened primary processes, the drainage of the filtrate into the Bowman's space may be hindered leading to the formation of small pseudocysts associated with bare areas of GBM. (5) The merging of pseudocysts created a system of communicating chambers through which the filtrate has to pass to reach Bowman's space. Multiple flow resistances in series likely generated an expansile force on podocytes contributing to detachment. (6) Such a situation appears to proceed to complete disconnection generally of a group of podocytes owing to the junctional connections between them. (7) Since such groups of detaching podocytes generally make contact to parietal cells, they start the formation of tuft adhesions to Bowman's capsule.

  11. Structural Analysis of How Podocytes Detach from the Glomerular Basement Membrane Under Hypertrophic Stress

    PubMed Central

    Kriz, Wilhelm; Hähnel, Brunhilde; Hosser, Hiltraud; Rösener, Sigrid; Waldherr, Rüdiger

    2014-01-01

    Podocytes are lost by detachment from the GBM as viable cells; details are largely unknown. We studied this process in the rat after growth stimulation with FGF-2. Endothelial and mesangial cells responded by hyperplasia, podocytes underwent hypertrophy, but, in the long run, developed various changes that could either be interpreted showing progressing stages in detachment from the GBM or stages leading to a tighter attachment by foot process effacement (FPE). This occurred in microdomains within the same podocyte; thus, features of detachment and of reinforced attachment may simultaneously be found in the same podocyte. (1) Initially, hypertrophied podocytes underwent cell body attenuation and formed large pseudocysts, i.e., expansions of the subpodocyte space. (2) Podocytes entered the process of FPE starting with the retraction of foot processes (FPs) and the replacement of the slit diaphragm by occluding junctions, thereby sealing the filtration slits. Successful completion of this process led to broad attachments of podocyte cell bodies to the GBM. (3) Failure of sealing the slits led to gaps of varying width between retracting FPs facilitating the outflow of the filtrate from the GBM. (4) Since those gaps are frequently overarched by broadened primary processes, the drainage of the filtrate into the Bowman’s space may be hindered leading to the formation of small pseudocysts associated with bare areas of GBM. (5) The merging of pseudocysts created a system of communicating chambers through which the filtrate has to pass to reach Bowman’s space. Multiple flow resistances in series likely generated an expansile force on podocytes contributing to detachment. (6) Such a situation appears to proceed to complete disconnection generally of a group of podocytes owing to the junctional connections between them. (7) Since such groups of detaching podocytes generally make contact to parietal cells, they start the formation of tuft adhesions to Bowman’s capsule

  12. Hybrid flotation--membrane filtration process for the removal of heavy metal ions from wastewater.

    PubMed

    Blöcher, C; Dorda, J; Mavrov, V; Chmiel, H; Lazaridis, N K; Matis, K A

    2003-09-01

    A promising process for the removal of heavy metal ions from aqueous solutions involves bonding the metals firstly to a special bonding agent and then separating the loaded bonding agents from the wastewater stream by separation processes. For the separation stage, a new hybrid process of flotation and membrane separation has been developed in this work by integrating specially designed submerged microfiltration modules directly into a flotation reactor. This made it possible to combine the advantages of both flotation and membrane separation while overcoming the limitations. The feasibility of this hybrid process was proven using powdered synthetic zeolites as bonding agents. Stable fluxes of up to 80l m(-2)h(-1) were achieved with the ceramic flat-sheet multi-channel membranes applied at low transmembrane pressure (<100 mbar). The process was applied in lab-scale to treat wastewater from the electronics industry. All toxic metals in question, namely copper, nickel and zinc, were reduced from initial concentrations of 474, 3.3 and 167mg x l(-1), respectively, to below 0.05 mg x l(-1), consistently meeting the discharge limits.

  13. Evolution of the combat and operational stress control detachment.

    PubMed

    Dailey, Jason I; Ijames, Victoria L

    2014-01-01

    Medical units designed to provide combat and operational stress control services have evolved since World War II into the current Combat and Operational Stress Control (COSC) detachments. Yet the structure of these COSC detachments differ greatly between what is authorized in the table of organization and equipment (TO&E) and what is doctrinally described in the current field manual guiding combat and operational stress control operations. We therefore explore the evolution of the COSC detachment, compare the organizations found in current doctrine with that currently authorized on the TO&E, and conclude with a proposed structure of a modern COSC detachment that is functionally modular with more clear chains of command.

  14. Unusual Li-Ion Transfer Mechanism in Liquid Electrolytes: A First-Principles Study.

    PubMed

    Tang, Zhen-Kun; Tse, John S; Liu, Li-Min

    2016-11-17

    Liquid electrolytes play an important role in commercial lithium-ion (Li-ion) batteries as a conduit for Li-ion transfer between anodes and cathodes. It is generally believed that the Li-ions move along with the salt ions; thus, Li-ion diffusion is only affected by the viscosity and salt concentration in the liquid electrolytes based on the Stokes-Einstein equation. In this study, a novel and faster Li-ion diffusion mechanism in electrolytes containing a cyanogen group is identified from first-principles molecular dynamics (FPMD) simulations. In this mechanism, the Li-ions are first detached from the Li-salt and then diffuse along with the solvent molecules, and the Li-ion diffusion does not obey the traditional Stokes-Einstein equation. The ionic conductivity of the electrolyte systems with this "solvent-assisted Li-ion diffusion" mechanism is further enhanced through Li-ion hopping. This novel Li-ion diffusion process explains recent findings of high Li-ion conductivity in electrolytes with cyanogen groups and furnishes a new paradigm for the design of fast-charging liquid electrolyte for Li-ion batteries.

  15. An Evaluation of Solution Algorithms and Numerical Approximation Methods for Modeling an Ion Exchange Process

    PubMed Central

    Bu, Sunyoung; Huang, Jingfang; Boyer, Treavor H.; Miller, Cass T.

    2010-01-01

    The focus of this work is on the modeling of an ion exchange process that occurs in drinking water treatment applications. The model formulation consists of a two-scale model in which a set of microscale diffusion equations representing ion exchange resin particles that vary in size and age are coupled through a boundary condition with a macroscopic ordinary differential equation (ODE), which represents the concentration of a species in a well-mixed reactor. We introduce a new age-averaged model (AAM) that averages all ion exchange particle ages for a given size particle to avoid the expensive Monte-Carlo simulation associated with previous modeling applications. We discuss two different numerical schemes to approximate both the original Monte Carlo algorithm and the new AAM for this two-scale problem. The first scheme is based on the finite element formulation in space coupled with an existing backward-difference-formula-based ODE solver in time. The second scheme uses an integral equation based Krylov deferred correction (KDC) method and a fast elliptic solver (FES) for the resulting elliptic equations. Numerical results are presented to validate the new AAM algorithm, which is also shown to be more computationally efficient than the original Monte Carlo algorithm. We also demonstrate that the higher order KDC scheme is more efficient than the traditional finite element solution approach and this advantage becomes increasingly important as the desired accuracy of the solution increases. We also discuss issues of smoothness, which affect the efficiency of the KDC-FES approach, and outline additional algorithmic changes that would further improve the efficiency of these developing methods for a wide range of applications. PMID:20577570

  16. An Evaluation of Solution Algorithms and Numerical Approximation Methods for Modeling an Ion Exchange Process.

    PubMed

    Bu, Sunyoung; Huang, Jingfang; Boyer, Treavor H; Miller, Cass T

    2010-07-01

    The focus of this work is on the modeling of an ion exchange process that occurs in drinking water treatment applications. The model formulation consists of a two-scale model in which a set of microscale diffusion equations representing ion exchange resin particles that vary in size and age are coupled through a boundary condition with a macroscopic ordinary differential equation (ODE), which represents the concentration of a species in a well-mixed reactor. We introduce a new age-averaged model (AAM) that averages all ion exchange particle ages for a given size particle to avoid the expensive Monte-Carlo simulation associated with previous modeling applications. We discuss two different numerical schemes to approximate both the original Monte Carlo algorithm and the new AAM for this two-scale problem. The first scheme is based on the finite element formulation in space coupled with an existing backward-difference-formula-based ODE solver in time. The second scheme uses an integral equation based Krylov deferred correction (KDC) method and a fast elliptic solver (FES) for the resulting elliptic equations. Numerical results are presented to validate the new AAM algorithm, which is also shown to be more computationally efficient than the original Monte Carlo algorithm. We also demonstrate that the higher order KDC scheme is more efficient than the traditional finite element solution approach and this advantage becomes increasingly important as the desired accuracy of the solution increases. We also discuss issues of smoothness, which affect the efficiency of the KDC-FES approach, and outline additional algorithmic changes that would further improve the efficiency of these developing methods for a wide range of applications.

  17. An evaluation of solution algorithms and numerical approximation methods for modeling an ion exchange process

    SciTech Connect

    Bu Sunyoung Huang Jingfang Boyer, Treavor H. Miller, Cass T.

    2010-07-01

    The focus of this work is on the modeling of an ion exchange process that occurs in drinking water treatment applications. The model formulation consists of a two-scale model in which a set of microscale diffusion equations representing ion exchange resin particles that vary in size and age are coupled through a boundary condition with a macroscopic ordinary differential equation (ODE), which represents the concentration of a species in a well-mixed reactor. We introduce a new age-averaged model (AAM) that averages all ion exchange particle ages for a given size particle to avoid the expensive Monte-Carlo simulation associated with previous modeling applications. We discuss two different numerical schemes to approximate both the original Monte-Carlo algorithm and the new AAM for this two-scale problem. The first scheme is based on the finite element formulation in space coupled with an existing backward difference formula-based ODE solver in time. The second scheme uses an integral equation based Krylov deferred correction (KDC) method and a fast elliptic solver (FES) for the resulting elliptic equations. Numerical results are presented to validate the new AAM algorithm, which is also shown to be more computationally efficient than the original Monte-Carlo algorithm. We also demonstrate that the higher order KDC scheme is more efficient than the traditional finite element solution approach and this advantage becomes increasingly important as the desired accuracy of the solution increases. We also discuss issues of smoothness, which affect the efficiency of the KDC-FES approach, and outline additional algorithmic changes that would further improve the efficiency of these developing methods for a wide range of applications.

  18. Inhibition effect of chlorine ion on hydroxyl radical generation in UV-H2O2 process.

    PubMed

    Tsuneda, S; Ishihara, Y; Hamachi, M; Hirata, A

    2002-01-01

    UV-H2O2 process is widely used as an advanced oxidation process (AOP) for the treatment of chlorine volatile organic compounds (CVOCs) such as dichloromethane (DCM) with strong oxidativity of hydroxyl radical generated from photolysis of H2O2. The result of DCM degradation rate at different initial concentrations in UV-H2O2 processes indicated the inhibition effect of produced chlorine ions on DCM oxidation processes, because the first-order degradation rate constant increased with lower initial concentrations. A spin trapping adduct of hydroxyl radical with 5,5-dimethyl-1-pyrroline-n-oxide (DMPO) was quantified by ESR spectrometer after UV irradiation in the presence of different amounts of chlorine ion, and as a result, the chlorine ion was found to act as a hydroxyl radical scavenger, which resulted in decreasing DCM degradation rate. An UV-H2O2 reactor equipped with ion exchangers for removing chlorine ion achieved higher DCM degradation rate than that without ion exchangers.

  19. A copper-catalyzed bioleaching process for enhancement of cobalt dissolution from spent lithium-ion batteries.

    PubMed

    Zeng, Guisheng; Deng, Xiaorong; Luo, Shenglian; Luo, Xubiao; Zou, Jianping

    2012-01-15

    A copper-catalyzed bioleaching process was developed to recycle cobalt from spent lithium-ion batteries (mainly LiCoO(2)) in this paper. The influence of copper ions on bioleaching of LiCoO(2) by Acidithiobacillus ferrooxidans (A.f) was investigated. It was shown that almost all cobalt (99.9%) went into solution after being bioleached for 6 days in the presence of 0.75 g/L copper ions, while only 43.1% of cobalt dissolution was obtained after 10 days without copper ions. EDX, XRD and SEM analyses additionally confirmed that the cobalt dissolution from spent lithium-ion batteries could be improved in the presence of copper ions. The catalytic mechanism was investigated to explain the enhancement of cobalt dissolution by copper ions, in which LiCoO(2) underwent a cationic interchange reaction with copper ions to form CuCo(2)O(4) on the surface of the sample, which could be easily dissolved by Fe(3+).

  20. Applicability of Different Hydraulic Parameters to Describe Soil Detachment in Eroding Rills

    PubMed Central

    Wirtz, Stefan; Seeger, Manuel; Zell, Andreas; Wagner, Christian; Wagner, Jean-Frank; Ries, Johannes B.

    2013-01-01

    This study presents the comparison of experimental results with assumptions used in numerical models. The aim of the field experiments is to test the linear relationship between different hydraulic parameters and soil detachment. For example correlations between shear stress, unit length shear force, stream power, unit stream power and effective stream power and the detachment rate does not reveal a single parameter which consistently displays the best correlation. More importantly, the best fit does not only vary from one experiment to another, but even between distinct measurement points. Different processes in rill erosion are responsible for the changing correlations. However, not all these procedures are considered in soil erosion models. Hence, hydraulic parameters alone are not sufficient to predict detachment rates. They predict the fluvial incising in the rill's bottom, but the main sediment sources are not considered sufficiently in its equations. The results of this study show that there is still a lack of understanding of the physical processes underlying soil erosion. Exerted forces, soil stability and its expression, the abstraction of the detachment and transport processes in shallow flowing water remain still subject of unclear description and dependence. PMID:23717669