A Quantum Non-Demolition Parity measurement in a mixed-species trapped-ion quantum processor

Science.gov (United States)

Marinelli, Matteo; Negnevitsky, Vlad; Lo, Hsiang-Yu; Flühmann, Christa; Mehta, Karan; Home, Jonathan

2017-04-01

Quantum non-demolition measurements of multi-qubit systems are an important tool in quantum information processing, in particular for syndrome extraction in quantum error correction. We have recently demonstrated a protocol for quantum non-demolition measurement of the parity of two beryllium ions by detection of a co-trapped calcium ion. The measurement requires a sequence of quantum gates between the three ions, using mixed-species gates between beryllium hyperfine qubits and a calcium optical qubit. Our work takes place in a multi-zone segmented trap setup in which we have demonstrated high fidelity control of both species and multi-well ion shuttling. The advantage of using two species of ion is that we can individually manipulate and read out the state of each ion species without disturbing the internal state of the other. The methods demonstrated here can be used for quantum error correcting codes as well as quantum metrology and are key ingredients for realizing a hybrid universal quantum computer based on trapped ions. Mixed-species control may also enable the investigation of new avenues in quantum simulation and quantum state control. left the group and working in a company now.

Temperature dependence and the moving species during ion mixing

International Nuclear Information System (INIS)

Xia, W.; Fernandes, M.; Hewett, C.A.; Lau, S.S.; Poker, D.B.; Biersack, J.P.

1988-01-01

In this paper, the authors review the experimental observations of the temperature dependence and the moving species in ion mixing, emphasizing the metal-semiconductor systems. Ion mixing is the combined effect of two components. One component is temperature independent and is primarily due to events in the prompt regime, the other component is temperature dependent and has the characteristics of the associated thermal reactions. The moving species during ion mixing are influenced by collisional effects, either due to secondary recoils, or due to local hot spots, or both. The secondary recoil concept is consistent with experimental observations that the motion of the lighter element in a bilayer sample is enhanced. There is ample evidence that while the a thermal regime is caused by particle-solid interactions, thermodynamical forces are important in deciding the magnitude of mixing. In the thermally activated regime, the ion induced reaction product should be influenced by the heats of formation of various compounds. We also indicate areas where satisfactory explanations are not available at present

Undesirable compounds in oils and fats: analysis and regulation

Directory of Open Access Journals (Sweden)

Lacoste Florence

2003-03-01

Full Text Available The aim of this paper is to present, for some undesirable compounds representative of the major origins, a comparison between the efficiency of the analytical methods used (sensitivity, precision and existing regulations. An idea of the different origins of the presence of undesirable compounds in oils and fats is given. Then a focus is done on guidelines on contaminant analysis provided by European directives or Codex Alimentarius. The reliability of some existing test methods compared to regulations is also examined: lead, hexane, polycyclic aromatic hydrocarbons, and pesticide residues.

Numerical analysis on the ion species ratios in a steady state hydrogen plasma

International Nuclear Information System (INIS)

Fukumasa, Osamu; Saeki, Setsuo; Osaki, Katashi; Sakiyama, Satoshi; Itatani, Ryohei.

1984-07-01

Ion species ratios in a hydrogen plasma are calculated systematically as a function of plasma parameters, i.e. the electron density, the electron temperature, the pressure of hydrogen gas and the plasma volume. Furthermore, in the present analysis, the recombination factor for hydrogen atoms at the wall surface of a vacuum vessel is treated as another plasma parameter. The most significant point is that ion species ratios depend strongly not only on plasma parameters, but also on the recombination factor. The proton ratio increases with decreasing value of the recombination factor. Primary electrons also play an important role for ion species ratios, and the presence of primary electrons causes the proton ratio to decrease. (author)

Cycles of undesirable substances in the food chain

International Nuclear Information System (INIS)

2012-01-01

The working group ''Carry over of undesirable substances in animal feed'' at the Federal Ministry of Food, Agriculture and Forestry (BMELV) in cooperation with the Institute of Animal Nutrition of the Friedrich-Loeffler-Institute (FLI) performed on 27 and 28 October 2011 in Braunschweig a workshop on ''cycles of undesirable substances in Food Chain ''. The aim of the workshop was to present the latest findings of research and Carry over Recommendations of the Carry over - Working Group on undesirable substances in feed and production processes of the feed industry, to evaluate and discuss about this with representatives from science, business and management and to work out the further research and action need. The focus of the considerations were the pathways, the carry over and the Exposure to dioxins and other halogenated hydrocarbons, the effects of Mycotoxins in feed and starting points for preventive measures, the soil contamination and the exposure of humans and animals by cadmium and case studies on Nitrite in feed, antibiotics in plants and residues of pesticides and radionuclides in feed. Furthermore the risks associated with specified manufacturing processes of feed are considered, especially the used materials that come into contact with animal feed, and the risks from nanotechnology. [de

The presence of undesirable mould species on the surface of dry sausages

Directory of Open Access Journals (Sweden)

Vesković-Moračanin Slavica M.

2008-01-01

Full Text Available Transition from manufacture to the industrial way of meat production and processing, as well as contemporary concept of food quality and safety, have led to the application of starter cultures. Their application leads towards the streamlining of the production process in the desired direction, quality improvement and its harmonization, and thereby to its standardization. Application of moulds in the meat industry is based on positive effects of their proteolytic and lipolytic egzoenzymes which, as a consequence, leads to the creation of characteristic sensory properties ('flavor' of fermented products. Penicillium nalgiovense is a typical representative of moulds used in the production of fermented sausages-salamis from our region. Samples of 'zimska salama' (dry sausage, produced with Penicillium nalgiovense, were evaluated as hygienically unacceptable. Their sensory properties changed due to contamination of this mould during the ripening process. Micological analysis discovered the presence of Penicillium aurantiogriseum, which is a frequent mould contaminant in the meat industry. At the same time, thin layer chromatography revealed no possibility of metabolic activity of this mould in the creation of mycotoxins. However, the presence of this mould on the surface of 'zimska salama' is considered as undesirable due to formation of 'off flavor' in products. Such product is considered as hygienically unacceptable and cannot be used for the human consumption.

Interventional radiology and undesirable effects

International Nuclear Information System (INIS)

Benderitter, M.

2009-01-01

As some procedures of interventional radiology are complex and long, doses received by patients can be high and cause undesired effects, notably on the skin or in underlying tissues (particularly in the brain as far as interventional neuroradiology is concerned and in lungs in the case of interventional cardiology). The author briefly discusses some deterministic effects in interventional radiology (influence of dose level, delay of appearance of effects, number of accidents). He briefly comments the diagnosis and treatment of severe radiological burns

Undesired Behaviors Faced in Classroom by Physics Teachers in High Schools

Science.gov (United States)

Bayar, Adem; Kerns, James H.

2015-01-01

The aim of this study is to define undesired behaviors in the classroom, to better understand the reasons of these undesired behaviors, and to offer strategies to overcome these behaviors. The researchers have used a qualitative research approach in this study. For this aim, the researchers have purposefully selected 12 physics teachers who work…

Energy efficiency of selected OECD countries: A slacks based model with undesirable outputs

International Nuclear Information System (INIS)

Apergis, Nicholas; Aye, Goodness C.; Barros, Carlos Pestana; Gupta, Rangan; Wanke, Peter

2015-01-01

This paper presents an efficiency assessment of selected OECD countries using a Slacks Based Model with undesirable or bad outputs (SBM-Undesirable). In this research, SBM-Undesirable is used first in a two-stage approach to assess the relative efficiency of OECD countries using the most frequent indicators adopted by the literature on energy efficiency. Besides, in the second stage, GLMM–MCMC methods are combined with SBM-Undesirable results as part of an attempt to produce a model for energy performance with effective predictive ability. The results reveal different impacts of contextual variables, such as economic blocks and capital–labor ratio, on energy efficiency levels. - Highlights: • We analyze the energy efficiency of selected OECD countries. • SBM-Undesirable and MCMC–GLMM are combined for this purpose. • Find that efficiency levels are high but declining over time. • Analysis with contextual variables shows varying efficiency levels across groups. • Capital-intensive countries are more energy efficient than labor-intensive countries.

Risk sectors for undesirable behaviour and mobbing

NARCIS (Netherlands)

Hubert, A.B.; Veldhoven, M.J.P.M. van

2001-01-01

The aim of this short note was to get an impression of risk sectors for the prevalence of undesirable behaviour and mobbing in The Netherlands. Data were collected from 1995 to 1999 with the Questionnaire on The Assessment and Experience of Work (Vragenlijst Beleving en Beoordeling van de Arbeid;

Transport of secondary electrons and reactive species in ion tracks

Science.gov (United States)

Surdutovich, Eugene; Solov'yov, Andrey V.

2015-08-01

The transport of reactive species brought about by ions traversing tissue-like medium is analysed analytically. Secondary electrons ejected by ions are capable of ionizing other molecules; the transport of these generations of electrons is studied using the random walk approximation until these electrons remain ballistic. Then, the distribution of solvated electrons produced as a result of interaction of low-energy electrons with water molecules is obtained. The radial distribution of energy loss by ions and secondary electrons to the medium yields the initial radial dose distribution, which can be used as initial conditions for the predicted shock waves. The formation, diffusion, and chemical evolution of hydroxyl radicals in liquid water are studied as well. COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy.

High resolution Thomson Parabola Spectrometer for full spectral capture of multi-species ion beams

International Nuclear Information System (INIS)

Alejo, A.; Kar, S.; Ahmed, H.; Doria, D.; Borghesi, M.; Tebartz, A.; Ding, J.; Neumann, N.; Astbury, S.; Carroll, D. C.; Scott, G. G.; Higginson, A.; McKenna, P.; Wagner, F.; Roth, M.

2016-01-01

We report on the experimental characterisation of laser-driven ion beams using a Thomson Parabola Spectrometer (TPS) equipped with trapezoidally shaped electric plates, proposed by Gwynne et al. [Rev. Sci. Instrum. 85, 033304 (2014)]. While a pair of extended (30 cm long) electric plates was able to produce a significant increase in the separation between neighbouring ion species at high energies, deploying a trapezoidal design circumvented the spectral clipping at the low energy end of the ion spectra. The shape of the electric plate was chosen carefully considering, for the given spectrometer configuration, the range of detectable ion energies and species. Analytical tracing of the ion parabolas matches closely with the experimental data, which suggests a minimal effect of fringe fields on the escaping ions close to the wedged edge of the electrode. The analytical formulae were derived considering the relativistic correction required for the high energy ions to be characterised using such spectrometer.

High resolution Thomson Parabola Spectrometer for full spectral capture of multi-species ion beams

Energy Technology Data Exchange (ETDEWEB)

Alejo, A.; Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.; Doria, D.; Borghesi, M. [Centre for Plasma Physics, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN (United Kingdom); Tebartz, A.; Ding, J.; Neumann, N. [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstrasse 9, D-64289 Darmstadt (Germany); Astbury, S.; Carroll, D. C.; Scott, G. G. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Higginson, A.; McKenna, P. [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Wagner, F. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstraße 9, D-64289 Darmstadt (Germany)

2016-08-15

We report on the experimental characterisation of laser-driven ion beams using a Thomson Parabola Spectrometer (TPS) equipped with trapezoidally shaped electric plates, proposed by Gwynne et al. [Rev. Sci. Instrum. 85, 033304 (2014)]. While a pair of extended (30 cm long) electric plates was able to produce a significant increase in the separation between neighbouring ion species at high energies, deploying a trapezoidal design circumvented the spectral clipping at the low energy end of the ion spectra. The shape of the electric plate was chosen carefully considering, for the given spectrometer configuration, the range of detectable ion energies and species. Analytical tracing of the ion parabolas matches closely with the experimental data, which suggests a minimal effect of fringe fields on the escaping ions close to the wedged edge of the electrode. The analytical formulae were derived considering the relativistic correction required for the high energy ions to be characterised using such spectrometer.

High resolution Thomson Parabola Spectrometer for full spectral capture of multi-species ion beams

Science.gov (United States)

Alejo, A.; Kar, S.; Tebartz, A.; Ahmed, H.; Astbury, S.; Carroll, D. C.; Ding, J.; Doria, D.; Higginson, A.; McKenna, P.; Neumann, N.; Scott, G. G.; Wagner, F.; Roth, M.; Borghesi, M.

2016-08-01

We report on the experimental characterisation of laser-driven ion beams using a Thomson Parabola Spectrometer (TPS) equipped with trapezoidally shaped electric plates, proposed by Gwynne et al. [Rev. Sci. Instrum. 85, 033304 (2014)]. While a pair of extended (30 cm long) electric plates was able to produce a significant increase in the separation between neighbouring ion species at high energies, deploying a trapezoidal design circumvented the spectral clipping at the low energy end of the ion spectra. The shape of the electric plate was chosen carefully considering, for the given spectrometer configuration, the range of detectable ion energies and species. Analytical tracing of the ion parabolas matches closely with the experimental data, which suggests a minimal effect of fringe fields on the escaping ions close to the wedged edge of the electrode. The analytical formulae were derived considering the relativistic correction required for the high energy ions to be characterised using such spectrometer.

Free-Will and the Undesirability of Moral Education

Science.gov (United States)

Gordon, David

1975-01-01

This paper makes two arguments: (1) that education does not imply determinism; and (2) that if one takes the libertarian position with regard to the free-will/determinism issue, one is forced to the conclusion that moral education is undesirable. (RC)

High-frequency heating of plasma with two ion species

International Nuclear Information System (INIS)

Klima, R.; Longinov, A.V.; Stepanov, K.N.

1975-01-01

The authors consider the penetration of electromagnetic waves with a frequency of the order of the ion cyclotron frequencies and with a fixed longitudinal wave number ksub(long), so that Nsub(long)=ksub(long)c/ω>>1 deep into an inhomogeneous plasma with two ion species. The propagation of two kinds of waves (fast and slow) with widely differing polarization and transverse refraction index is possible. For both types of waves there is an evanescence region at the plasma periphery. The evanescence region is narrow for slow waves and they easily penetrate the plasma. In a dense plasma they become electrostatic and can reach the ion-ion hybrid resonance region. However, the damping of these waves due to Cherenkov interaction with electrons in a high-temperature plasma is strong and therefore they are not suitable for heating plasma of large dimensions, as they are absorbed at the plasma periphery. The fast waves have a wider evanescence region and can be excited effectively only if N 2 is not too high. These waves can be completely absorbed in the plasma (due to Cherenkov interaction with electrons) if xi approximately (v 2 sub(Ti)/v 2 sub(A))Zsub(e)(ωsub(pi)a/c)exp(-Zsub(e) 2 ) > 1, where a is the plasma radius and Zsub(e) = ω/(√2 ksub(long)vsub(Te)). Fast waves can also reach the region where they are transformed into slow waves. In this region their damping increases considerably. It is shown that the transformation region in an inhomogeneous plasma with two ion species in a non-uniform magnetic field may be at the centre of the plasma. Fast waves can be used effectively for heating plasma of large dimensions. (author)

Theory for nonlinear magnetosonic waves in a two-ion-species plasma

International Nuclear Information System (INIS)

Toida, Mieko; Ohsawa, Yukiharu

1997-01-01

Magnetosonic waves propagating perpendicular to a magnetic field in a plasma containing two ion species is studied theoretically. The magnetosonic wave is split into two modes in a two-ion-species plasma; low- and high- frequency modes. The frequency of the low-frequency mode tends to zero as the wave number k goes to zero. A KdV equation is derived for this mode by the conventional reductive perturbation method. The frequency of high-frequency mode does not go to zero as k → 0. However, using a new expansion scheme, a KdV equation for the nonlinear high-frequency mode has also been derived. This shows that KdV equations are not limited to waves whose frequencies tend to zero as k → 0. The KdV equation for the low-frequency mode is valid when the amplitudes ε are quite small, while that for the high-frequency mode is valid when (m. e /m. i ) 1/2 e /m. i is a measure of electron-to-ion mass ratios. The characteristic soliton widths are the ion inertia length for the low-frequency mode and the electron skin depth for the high-frequency mode. (author)

A Case of Undesired Bleb Developed After Penetrating Injury

Directory of Open Access Journals (Sweden)

Cem Ozgonul

2014-03-01

Full Text Available Eighty-year-old male patient was admitted to our policlinic with stinging, burning and itching in both eyes. Ophthalmological examination revealed avascular undesired bleb that releated with anterior chamber at 2-3 hour quadrant nasal limbus with the surrounding corneal and conjunctival epithelium was vascularized and the dimension was 3x3x3 mm. Towards these findings, we questioned the patient again and we found that, 40 years ago, a broken part of the shaving razor had injured his eye. After penetrating injury of the eye, because of the sutured wound leakage, undesired bleb formations can be seen. We suggest that kind of patient shold be followed up to prevent late complications of penetrating injury.

Recent developments in the Thomson Parabola Spectrometer diagnostic for laser-driven multi-species ion sources

International Nuclear Information System (INIS)

Alejo, A.; Gwynne, D.; Doria, D.; Ahmed, H.; Borghesi, M.; Kar, S.; Carroll, D.C.; Clarke, R.J.; Neely, D.; Scott, G.G.

2016-01-01

Ongoing developments in laser-driven ion acceleration warrant appropriate modifications to the standard Thomson Parabola Spectrometer (TPS) arrangement in order to match the diagnostic requirements associated to the particular and distinctive properties of laser-accelerated beams. Here we present an overview of recent developments by our group of the TPS diagnostic aimed to enhance the capability of diagnosing multi-species high-energy ion beams. In order to facilitate discrimination between ions with same Z / A , a recursive differential filtering technique was implemented at the TPS detector in order to allow only one of the overlapping ion species to reach the detector, across the entire energy range detectable by the TPS. In order to mitigate the issue of overlapping ion traces towards the higher energy part of the spectrum, an extended, trapezoidal electric plates design was envisaged, followed by its experimental demonstration. The design allows achieving high energy-resolution at high energies without sacrificing the lower energy part of the spectrum. Finally, a novel multi-pinhole TPS design is discussed, that would allow angularly resolved, complete spectral characterization of the high-energy, multi-species ion beams.

Recent developments in the Thomson Parabola Spectrometer diagnostic for laser-driven multi-species ion sources

Science.gov (United States)

Alejo, A.; Gwynne, D.; Doria, D.; Ahmed, H.; Carroll, D. C.; Clarke, R. J.; Neely, D.; Scott, G. G.; Borghesi, M.; Kar, S.

2016-10-01

Ongoing developments in laser-driven ion acceleration warrant appropriate modifications to the standard Thomson Parabola Spectrometer (TPS) arrangement in order to match the diagnostic requirements associated to the particular and distinctive properties of laser-accelerated beams. Here we present an overview of recent developments by our group of the TPS diagnostic aimed to enhance the capability of diagnosing multi-species high-energy ion beams. In order to facilitate discrimination between ions with same Z/A, a recursive differential filtering technique was implemented at the TPS detector in order to allow only one of the overlapping ion species to reach the detector, across the entire energy range detectable by the TPS. In order to mitigate the issue of overlapping ion traces towards the higher energy part of the spectrum, an extended, trapezoidal electric plates design was envisaged, followed by its experimental demonstration. The design allows achieving high energy-resolution at high energies without sacrificing the lower energy part of the spectrum. Finally, a novel multi-pinhole TPS design is discussed, that would allow angularly resolved, complete spectral characterization of the high-energy, multi-species ion beams.

Desirable and undesirable future thoughts call for different scene construction processes.

Science.gov (United States)

de Vito, S; Neroni, M A; Gamboz, N; Della Sala, S; Brandimonte, M A

2015-01-01

Despite the growing interest in the ability of foreseeing (episodic future thinking), it is still unclear how healthy people construct possible future scenarios. We suggest that different future thoughts require different processes of scene construction. Thirty-five participants were asked to imagine desirable and less desirable future events. Imagining desirable events increased the ease of scene construction, the frequency of life scripts, the number of internal details, and the clarity of sensorial and spatial temporal information. The initial description of general personal knowledge lasted longer in undesirable than in desirable anticipations. Finally, participants were more prone to explicitly indicate autobiographical memory as the main source of their simulations of undesirable episodes, whereas they equally related the simulations of desirable events to autobiographical events or semantic knowledge. These findings show that desirable and undesirable scenarios call for different mechanisms of scene construction. The present study emphasizes that future thinking cannot be considered as a monolithic entity.

Enhanced DEA model with undesirable output and interval data for rice growing farmers performance assessment

Energy Technology Data Exchange (ETDEWEB)

Khan, Sahubar Ali Mohd. Nadhar, E-mail: sahubar@uum.edu.my; Ramli, Razamin, E-mail: razamin@uum.edu.my; Baten, M. D. Azizul, E-mail: baten-math@yahoo.com [School of Quantitative Sciences, UUM College of Arts and Sciences, Universiti Utara Malaysia, 06010 Sintok, Kedah (Malaysia)

2015-12-11

Agricultural production process typically produces two types of outputs which are economic desirable as well as environmentally undesirable outputs (such as greenhouse gas emission, nitrate leaching, effects to human and organisms and water pollution). In efficiency analysis, this undesirable outputs cannot be ignored and need to be included in order to obtain the actual estimation of firms efficiency. Additionally, climatic factors as well as data uncertainty can significantly affect the efficiency analysis. There are a number of approaches that has been proposed in DEA literature to account for undesirable outputs. Many researchers has pointed that directional distance function (DDF) approach is the best as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, it has been found that interval data approach is the most suitable to account for data uncertainty as it is much simpler to model and need less information regarding its distribution and membership function. In this paper, an enhanced DEA model based on DDF approach that considers undesirable outputs as well as climatic factors and interval data is proposed. This model will be used to determine the efficiency of rice farmers who produces undesirable outputs and operates under uncertainty. It is hoped that the proposed model will provide a better estimate of rice farmers’ efficiency.

Enhanced DEA model with undesirable output and interval data for rice growing farmers performance assessment

International Nuclear Information System (INIS)

Khan, Sahubar Ali Mohd. Nadhar; Ramli, Razamin; Baten, M. D. Azizul

2015-01-01

Agricultural production process typically produces two types of outputs which are economic desirable as well as environmentally undesirable outputs (such as greenhouse gas emission, nitrate leaching, effects to human and organisms and water pollution). In efficiency analysis, this undesirable outputs cannot be ignored and need to be included in order to obtain the actual estimation of firms efficiency. Additionally, climatic factors as well as data uncertainty can significantly affect the efficiency analysis. There are a number of approaches that has been proposed in DEA literature to account for undesirable outputs. Many researchers has pointed that directional distance function (DDF) approach is the best as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, it has been found that interval data approach is the most suitable to account for data uncertainty as it is much simpler to model and need less information regarding its distribution and membership function. In this paper, an enhanced DEA model based on DDF approach that considers undesirable outputs as well as climatic factors and interval data is proposed. This model will be used to determine the efficiency of rice farmers who produces undesirable outputs and operates under uncertainty. It is hoped that the proposed model will provide a better estimate of rice farmers’ efficiency

Enhanced DEA model with undesirable output and interval data for rice growing farmers performance assessment

Science.gov (United States)

Khan, Sahubar Ali Mohd. Nadhar; Ramli, Razamin; Baten, M. D. Azizul

2015-12-01

Agricultural production process typically produces two types of outputs which are economic desirable as well as environmentally undesirable outputs (such as greenhouse gas emission, nitrate leaching, effects to human and organisms and water pollution). In efficiency analysis, this undesirable outputs cannot be ignored and need to be included in order to obtain the actual estimation of firms efficiency. Additionally, climatic factors as well as data uncertainty can significantly affect the efficiency analysis. There are a number of approaches that has been proposed in DEA literature to account for undesirable outputs. Many researchers has pointed that directional distance function (DDF) approach is the best as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, it has been found that interval data approach is the most suitable to account for data uncertainty as it is much simpler to model and need less information regarding its distribution and membership function. In this paper, an enhanced DEA model based on DDF approach that considers undesirable outputs as well as climatic factors and interval data is proposed. This model will be used to determine the efficiency of rice farmers who produces undesirable outputs and operates under uncertainty. It is hoped that the proposed model will provide a better estimate of rice farmers' efficiency.

Electrochemical evidences and consequences of significant differences in ions diffusion rate in polyacrylate-based ion-selective membranes.

Science.gov (United States)

Woźnica, Emilia; Mieczkowski, Józef; Michalska, Agata

2011-11-21

The origin and effect of surface accumulation of primary ions within the ion-selective poly(n-butyl acrylate)-based membrane, obtained by thermal polymerization, is discussed. Using a new method, based on the relation between the shape of a potentiometric plot and preconditioning time, the diffusion of copper ions in the membrane was found to be slow (the diffusion coefficient estimated to be close to 10(-11) cm(2) s(-1)), especially when compared to ion-exchanger counter ions--sodium cations diffusion (a diffusion coefficient above 10(-9) cm(2) s(-1)). The higher mobility of sodium ions than those of the copper-ionophore complex results in exposed ion-exchanger role leading to undesirably exposed sensitivity to sodium or potassium ions.

Modified Thomson spectrometer design for high energy, multi-species ion sources

International Nuclear Information System (INIS)

Gwynne, D.; Kar, S.; Doria, D.; Ahmed, H.; Hanton, F.; Cerchez, M.; Swantusch, M.; Willi, O.; Fernandez, J.; Gray, R. J.; MacLellan, D. A.; McKenna, P.; Green, J. S.; Neely, D.; Najmudin, Z.; Streeter, M.; Ruiz, J. A.; Schiavi, A.; Zepf, M.; Borghesi, M.

2014-01-01

A modification to the standard Thomson parabola spectrometer is discussed, which is designed to measure high energy (tens of MeV/nucleon), broad bandwidth spectra of multi-species ions accelerated by intense laser plasma interactions. It is proposed to implement a pair of extended, trapezoidal shaped electric plates, which will not only resolve ion traces at high energies, but will also retain the lower energy part of the spectrum. While a longer (along the axis of the undeflected ion beam direction) electric plate design provides effective charge state separation at the high energy end of the spectrum, the proposed new trapezoidal shape will enable the low energy ions to reach the detector, which would have been clipped or blocked by simply extending the rectangular plates to enhance the electrostatic deflection

Coupled Membrane Transport Parameters for Ionic Species in All-Vanadium Redox Flow Batteries

International Nuclear Information System (INIS)

Ashraf Gandomi, Yasser; Aaron, D.S.; Mench, M.M.

2016-01-01

Highlights: • Real-time crossover of vanadium species was investigated with a novel system. • Concentration and electrostatic potential gradient-induced crossover was separated. • Interaction coefficients were introduced to account for state of charge dependence. • Electric-field-induced crossover is asymmetric for charge and discharge processes. • Net vanadium crossover is from negative to positive half-cell at open-circuit. - Abstract: One of the major sources of capacity loss in all-vanadium redox flow batteries (VRFBs) is the undesired transport of active vanadium species across the ion-exchange membrane, generically termed crossover. In this work, a novel system has been designed and built to investigate the concentration- and electrostatic potential gradient-driven crossover for all vanadium species through the membrane in real-time. For this study, a perfluorosulphonic acid membrane separator (Nafion ® 117) was used. The test system utilizes ultraviolet/visible (UV/Vis) spectroscopy to differentiate vanadium ion species and separates contributions to crossover stemming from concentration and electrostatic potential gradients. It is shown that the rate of species transport through the ion-exchange membrane is state of charge dependent and, as a result, interaction coefficients have been deduced which can be used to better estimate expected crossover over a range of operating conditions. The electric field was shown to increase the negative-to-positive transport of V(II)/V(III) and suppress the positive-to-negative transport of V(IV)/V(V) during discharge, with an inverse trend during charging conditions. Electric-field-induced transport coefficients were deduced directly from experimental data.

An analytic expression for the sheath criterion in magnetized plasmas with multi-charged ion species

International Nuclear Information System (INIS)

Hatami, M. M.

2015-01-01

The generalized Bohm criterion in magnetized multi-component plasmas consisting of multi-charged positive and negative ion species and electrons is analytically investigated by using the hydrodynamic model. It is assumed that the electrons and negative ion density distributions are the Boltzmann distribution with different temperatures and the positive ions enter into the sheath region obliquely. Our results show that the positive and negative ion temperatures, the orientation of the applied magnetic field and the charge number of positive and negative ions strongly affect the Bohm criterion in these multi-component plasmas. To determine the validity of our derived generalized Bohm criterion, it reduced to some familiar physical condition and it is shown that monotonically reduction of the positive ion density distribution leading to the sheath formation occurs only when entrance velocity of ion into the sheath satisfies the obtained Bohm criterion. Also, as a practical application of the obtained Bohm criterion, effects of the ionic temperature and concentration as well as magnetic field on the behavior of the charged particle density distributions and so the sheath thickness of a magnetized plasma consisting of electrons and singly charged positive and negative ion species are studied numerically

A two stage data envelopment analysis model with undesirable output

Science.gov (United States)

Shariff Adli Aminuddin, Adam; Izzati Jaini, Nur; Mat Kasim, Maznah; Nawawi, Mohd Kamal Mohd

2017-09-01

The dependent relationship among the decision making units (DMU) is usually assumed to be non-existent in the development of Data Envelopment Analysis (DEA) model. The dependency can be represented by the multi-stage DEA model, where the outputs from the precedent stage will be the inputs for the latter stage. The multi-stage DEA model evaluate both the efficiency score for each stages and the overall efficiency of the whole process. The existing multi stage DEA models do not focus on the integration with the undesirable output, in which the higher input will generate lower output unlike the normal desirable output. This research attempts to address the inclusion of such undesirable output and investigate the theoretical implication and potential application towards the development of multi-stage DEA model.

Application of TXRF for ion implanter dose matching experiments

Science.gov (United States)

Frost, M. R.; French, M.; Harris, W.

2004-06-01

Secondary ion mass spectrometry (SIMS) has been utilized for many years to measure the dose of ion implants in silicon for the purpose of verifying the ability of ion implantation equipment to accurately and reproducibly implant the desired species at the target dose. The development of statistically and instrumentally rigorous protocols has lead to high confidence levels, particularly with regard to accuracy and short-term repeatability. For example, high-dose, high-energy B implant dosimetry can be targeted to within ±1%. However, performing dose determination experiments using SIMS does have undesirable aspects, such as being highly labor intensive and sample destructive. Modern total reflection X-ray fluorescence (TXRF) instruments are equipped with capabilities for full 300 mm wafer handling, automated data acquisition software and intense X-ray sources. These attributes enable the technique to overcome the SIMS disadvantages listed above, as well as provide unique strengths that make it potentially highly amenable to implanter dose matching. In this paper, we report on data collected to date that provides confidence that TXRF is an effective and economical method to perform these measurements within certain limitations. We have investigated a number of ion implanted species that are within the "envelope" of TXRF application. This envelope is defined by a few important parameters. Species: For the anode materials used in the more common X-ray sources on the market, each has its own set of elements that can be detected. We have investigated W and Mo X-ray sources, which are the most common in use in commercial instrumentation. Implant energy: In general, if the energy of the implanted species is too high (or more specifically, the distribution of the implanted species is too deep), the amount of dopant not detected by TXRF may be significant, increasing the error of the measurement. Therefore, for each species investigated, the implant energy cannot exceed a

Picomolar detection limits with current-polarized Pb2+ ion-selective membranes.

Science.gov (United States)

Pergel, E; Gyurcsányi, R E; Tóth, K; Lindner, E

2001-09-01

Minor ion fluxes across ion-selective membranes bias submicromolar activity measurements with conventional ion-selective electrodes. When ion fluxes are balanced, the lower limit of detection is expected to be dramatically improved. As proof of principle, the flux of lead ions across an ETH 5435 ionophore-based lead-selective membrane was gradually compensated by applying a few nanoamperes of galvanostatic current. When the opposite ion fluxes were matched, and the undesirable leaching of primary ions was eliminated, Nernstian response down to 3 x 10(-12) M was achieved.

Measurements of ion velocity separation and ionization in multi-species plasma shocks

Science.gov (United States)

Rinderknecht, Hans G.; Park, H.-S.; Ross, J. S.; Amendt, P. A.; Wilks, S. C.; Katz, J.; Hoffman, N. M.; Kagan, G.; Vold, E. L.; Keenan, B. D.; Simakov, A. N.; Chacón, L.

2018-05-01

The ion velocity structure of a strong collisional shock front in a plasma with multiple ion species is directly probed in laser-driven shock-tube experiments. Thomson scattering of a 263.25 nm probe beam is used to diagnose ion composition, temperature, and flow velocity in strong shocks ( M ˜6 ) propagating through low-density ( ρ˜0.1 mg/cc) plasmas composed of mixtures of hydrogen (98%) and neon (2%). Within the preheat region of the shock front, two velocity populations of ions are observed, a characteristic feature of strong plasma shocks. The ionization state of the Ne is observed to change within the shock front, demonstrating an ionization-timescale effect on the shock front structure. The forward-streaming proton feature is shown to be unexpectedly cool compared to predictions from ion Fokker-Planck simulations; the neon ionization gradient is evaluated as a possible cause.

Theoretical calculations of the self-reflection coefficients for some species of ions

Energy Technology Data Exchange (ETDEWEB)

Luo, Z.M. E-mail: luozm@scu.edu.cn; Gou, C.; Hou, Q

2002-06-01

The bipartition model of ion transport has been applied to study the self-reflection coefficients of some species of ion beams which are normally incident to a surface. The computational results has been compared with the results taken from Eckstein and Biersack and the compilation data given by Thomas, Janev and Smith. It was found that there are in reasonable agreement between the results given by the bipartition model and the results given by Monte Carlo method.

Transport of a multiple ion species plasma in the Pfirsch--Schluter regime

International Nuclear Information System (INIS)

Hirshman, S.P.

1976-10-01

The classical parallel friction coefficients, which relate the collisional friction forces to the flow of particles and heat along the magnetic field, are calculated for a multiple ion species plasma. In the short mean free path regime, the neoclassical Pfirsch--Schlueter transport coefficients for a toroidally confined multispecies plasma are computed in terms of the classical friction coefficients. The dependence of the neoclassical cross-field transport on the equilibration of the parallel ion temperature profiles is determined

Data Envelopment Analysis with Fixed Inputs, Undesirable Outputs and Negative Data

Directory of Open Access Journals (Sweden)

F. Seyed Esmaeili

2017-03-01

Full Text Available In Data Envelopment Analysis (DEA, different models have been measured to evaluate the performance of decision making units with multiple inputs and outputs. Revised model of Slack-based measures known as MBSM of collective models family has been introduced by Sharp et al. Slack-based measure has been introduced by Ton. In this study, a model is proposed that is able to estimate the efficiency when a number of outputs of decision making units are undesirable, inputs are fixed and some of outputs and inputs are negative. So that, level of undesirable output is reduced at the constant level of inputs in the evaluation unit and by conserving the efficiency.

Ion acoustic solitons/double layers in two-ion plasma revisited

International Nuclear Information System (INIS)

Lakhina, G. S.; Singh, S. V.; Kakad, A. P.

2014-01-01

Ion acoustic solitons and double layers are studied in a collisionless plasma consisting of cold heavier ion species, a warm lighter ion species, and hot electrons having Boltzmann distributions by Sagdeev pseudo-potential technique. In contrast to the previous results, no double layers and super-solitons are found when both the heavy and lighter ion species are treated as cold. Only the positive potential solitons are found in this case. When the thermal effects of the lighter ion species are included, in addition to the usual ion-acoustic solitons occurring at M > 1 (where the Mach number, M, is defined as the ratio of the speed of the solitary wave and the ion-acoustic speed considering temperature of hot electrons and mass of the heavier ion species), slow ion-acoustic solitons/double layers are found to occur at low Mach number (M < 1). The slow ion-acoustic mode is actually a new ion-ion hybrid acoustic mode which disappears when the normalized number density of lighter ion species tends to 1 (i.e., no heavier species). An interesting property of the new slow ion-acoustic mode is that at low number density of the lighter ion species, only negative potential solitons/double layers are found whereas for increasing densities there is a transition first to positive solitons/double layers, and then only positive solitons. The model can be easily applicable to the dusty plasmas having positively charged dust grains by replacing the heavier ion species by the dust mass and doing a simple normalization to take account of the dust charge

The Possibility of Ce3+ and Mn2+ Complex Ions Formation With Iodine Species in a Dushman Reaction

Directory of Open Access Journals (Sweden)

Iurie Ungureanu

2018-06-01

Full Text Available This contribution presents investigations into possible effects of Ce3+ and Mn2+ on the reduction of UV-spectral signal for I3- observed e.g. in the Dushman reaction. The potential of the metal ions to form complexes with iodine-containing species was analysed. It was shown that no complex ions are formed between Ce3+ and Mn2+ metals ions with IO3-, I-, I2 species. Only the formation of a very weak CeI32+ complex ion was found to occur. An effect of a complex formation on the studied systems could be excluded.

Operation condition for continuous anti-solvent crystallization of CBZ-SAC cocrystal considering deposition risk of undesired crystals

Science.gov (United States)

Nishimaru, Momoko; Nakasa, Miku; Kudo, Shoji; Takiyama, Hiroshi

2017-07-01

Crystallization operation of cocrystal production has deposition risk of undesired crystals. Simultaneously, continuous manufacturing processes are focused on. In this study, conditions for continuous cocrystallization considering risk reduction of undesired crystals deposition were investigated on the view point of thermodynamics and kinetics. The anti-solvent cocrystallization was carried out in four-component system of carbamazepine, saccharin, methanol and water. From the preliminary batch experiment, the relationships among undesired crystal deposition, solution composition decided by mixing ratio of solutions, and residence time for the crystals were considered, and then the conditions of continuous experiment were decided. Under these conditions, the continuous experiment was carried out. The XRD patterns of obtained crystals in the continuous experiment showed that desired cocrystals were obtained without undesired crystals. This experimental result was evaluated by using multi-component phase diagrams from the view point of the operation point's movement. From the evaluation, it was found that there is a certain operation condition which the operation point is fixed with time in the specific domain without the deposition risk of undesired single component crystals. It means the possibility of continuous production of cocrystals without deposition risk of undesired crystals was confirmed by using multi-component phase diagrams.

Automated identification and quantification of glycerophospholipid molecular species by multiple precursor ion scanning

DEFF Research Database (Denmark)

Ejsing, Christer S.; Duchoslav, Eva; Sampaio, Julio

2006-01-01

We report a method for the identification and quantification of glycerophospholipid molecular species that is based on the simultaneous automated acquisition and processing of 41 precursor ion spectra, specific for acyl anions of common fatty acids moieties and several lipid class-specific fragment...... of glycerophospholipids. The automated analysis of total lipid extracts was powered by a robotic nanoflow ion source and produced currently the most detailed description of the glycerophospholipidome....

Undesirable substances in vegetable oils: anything to declare?

Directory of Open Access Journals (Sweden)

Lacoste Florence

2014-01-01

Full Text Available The presence of undesirable compounds in vegetable and animal oils and fats may have many different origins. Although the potential toxicity of most of these undesirable compounds is real, poisoning risks are rather limited due to the efficient elimination during oil-refining steps, careful conditioning, choice of efficient packaging and industrial quality control management. However the research of contaminants is part of multiple controls conducted by fat and oil industry to verify the conformity of products placed on the market in relation to regulations such as the European commission regulation EC No. 1881/2006 setting maximum levels for some contaminants in food as lead, some mycotoxins, dioxins, polychlorobiphenyls, benzo[a]pyrene. In the absence of regulation, the detection of contaminants must be addressed in partnership with authorities according to the toxicity of molecules. The controls are not confined to environmental contaminants. They also include compounds that can be formed during the production process of vegetable oils such as esters of 3-monochloropropanediol. This article focuses more particularly on heavy metals, polycyclic aromatic hydrocarbons, mineral oils, phthalates and 3-MCPD or glycidyl esters. Aspects such as methods for analysis, limits fixed by EC regulation and occurrence in vegetable oils are discussed.

Ranking of bank branches with undesirable and fuzzy data: A DEA-based approach

Directory of Open Access Journals (Sweden)

Sohrab Kordrostami

2016-07-01

Full Text Available Banks are one of the most important financial sectors in order to the economic development of each country. Certainly, efficiency scores and ranks of banks are significant and effective aspects towards future planning. Sometimes the performance of banks must be measured in the presence of undesirable and vague factors. For these reasons in the current paper a procedure based on data envelopment analysis (DEA is introduced for evaluating the efficiency and complete ranking of decision making units (DMUs where undesirable and fuzzy measures exist. To illustrate, in the presence of undesirable and fuzzy measures, DMUs are evaluated by using a fuzzy expected value approach and DMUs with similar efficiency scores are ranked by using constraints and the Maximal Balance Index based on the optimal shadow prices. Afterwards, the efficiency scores of 25 branches of an Iranian commercial bank are evaluated using the proposed method. Also, a complete ranking of bank branches is presented to discriminate branches.

Wall effects on the propagation of compressional Alfven waves in a cylindrical plasma with two-ion species

International Nuclear Information System (INIS)

Akiyama, H.; Hayler, M.O.; Kristiansen, M.

1985-01-01

The dispersion relations for the compressional Alfven waves in a two-ion species plasma of deuterium and hydrogen are calculated for a configuration which includes a vacuum layer between the cylindrical plasma and the conducting wall. The presence of the vacuum layer strongly affects the propagation of the compressional Alfven wave, permitting some branches to propagate and penetrate the plasma column over most frequencies in the ion-cyclotron range. Basic Alfven-wave propagation and heating experiments in two-ion species consequently should be possible using tokamak and mirror devices with minor radii smaller than the Alfven wavelength

Pesticides Curbing Soil Fertility: Effect of Complexation of Free Metal Ions

Science.gov (United States)

Kaur, Sukhmanpreet; Kumar, Vijay; Chawla, Mohit; Cavallo, Luigi; Poater, Albert; Upadhyay, Niraj

2017-07-01

Researchers have suggested that the reason behind infertility is pernicious effect of broad spectrum pesticides on non target, beneficial microorganism of soil. Here, studying the chelating effect of selective organophosphate and carbamate pesticides with essential metal ions, at all possible combinations of three different pH (4±0.05, 7±0.05 and 9±0.05) and three different temperatures (15±0.5°C, 30±0.5°C and 45±0.5°C), shows very fast rate of reaction which further increases with increase of pH and temperature. Carbonyl oxygen of carbamate and phosphate oxygen of organophosphate were found to be common ligating sites among all the complexes. Formed metal complexes were found to be highly stable and water insoluble on interaction with essential metal ions in solvent medium as well as over silica. Density functional theory (DFT) calculations not only reinforced the experimental observations, but, after a wide computational conformational analysis, unraveled the nature of the high stable undesired species that consist of pesticides complexed by metal ions from the soil. All in all, apart from the direct toxicity of pesticides, the indirect effect by means of complexation of free metal ions impoverishes the soil.

Pesticides Curbing Soil Fertility: Effect of Complexation of Free Metal Ions

KAUST Repository

Kaur, Sukhmanpreet

2017-07-04

Researchers have suggested that the reason behind infertility is pernicious effect of broad spectrum pesticides on non target, beneficial microorganism of soil. Here, studying the chelating effect of selective organophosphate and carbamate pesticides with essential metal ions, at all possible combinations of three different pH (4 ± 0.05, 7 ± 0.05 and 9 ± 0.05) and three different temperatures (15 ± 0.5°C, 30 ± 0.5°C and 45 ± 0.5°C), shows very fast rate of reaction which further increases with increase of pH and temperature. Carbonyl oxygen of carbamate and phosphate oxygen of organophosphate were found to be common ligating sites among all the complexes. Formed metal complexes were found to be highly stable and water insoluble on interaction with essential metal ions in solvent medium as well as over silica. Density functional theory (DFT) calculations not only reinforced the experimental observations, but, after a wide computational conformational analysis, unraveled the nature of the high stable undesired species that consist of pesticides complexed by metal ions from the soil. All in all, apart from the direct toxicity of pesticides, the indirect effect by means of complexation of free metal ions impoverishes the soil.

Pesticides Curbing Soil Fertility: Effect of Complexation of Free Metal Ions

KAUST Repository

Kaur, Sukhmanpreet; Kumar, Vijay; Chawla, Mohit; Cavallo, Luigi; Poater, Albert; Upadhyay, Niraj

2017-01-01

Researchers have suggested that the reason behind infertility is pernicious effect of broad spectrum pesticides on non target, beneficial microorganism of soil. Here, studying the chelating effect of selective organophosphate and carbamate pesticides with essential metal ions, at all possible combinations of three different pH (4 ± 0.05, 7 ± 0.05 and 9 ± 0.05) and three different temperatures (15 ± 0.5°C, 30 ± 0.5°C and 45 ± 0.5°C), shows very fast rate of reaction which further increases with increase of pH and temperature. Carbonyl oxygen of carbamate and phosphate oxygen of organophosphate were found to be common ligating sites among all the complexes. Formed metal complexes were found to be highly stable and water insoluble on interaction with essential metal ions in solvent medium as well as over silica. Density functional theory (DFT) calculations not only reinforced the experimental observations, but, after a wide computational conformational analysis, unraveled the nature of the high stable undesired species that consist of pesticides complexed by metal ions from the soil. All in all, apart from the direct toxicity of pesticides, the indirect effect by means of complexation of free metal ions impoverishes the soil.

32 CFR 887.7 - Persons separated under other than honorable conditions (undesirable or bad conduct) or...

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Persons separated under other than honorable conditions (undesirable or bad conduct) or dishonorable discharge. 887.7 Section 887.7 National Defense... honorable conditions (undesirable or bad conduct) or dishonorable discharge. Those persons whose character...

Worry and perceived threat of proximal and distal undesirable outcomes.

Science.gov (United States)

Bredemeier, Keith; Berenbaum, Howard; Spielberg, Jeffrey M

2012-04-01

Individuals who are prone to worry tend to overestimate the likelihoods and costs of future undesirable outcomes. However, it is unclear whether these relations vary as a function of the timeframe of the event in question. In the present study, 342 undergraduate students completed a self-report measure of worry and rated the perceived probabilities and costs of 40 undesirable outcomes. Specifically, each participant estimated the probability that each of these outcomes would occur within three different timeframes: the next month, the next year, and the next 10 years. We found that the strength of the association between worry and probability estimates was strongest for the most proximal timeframe. Probability estimates were more strongly associated with worry for participants with elevated cost estimates, and this interactive effect was strongest for the most distal timeframe. Implications of these findings for understanding the etiology and treatment of excessive worry are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

The kick-out mass selection technique for ions stored in an Electrostatic Ion Beam Trap

International Nuclear Information System (INIS)

Toker, Y; Altstein, N; Aviv, O; Rappaport, M L; Heber, O; Schwalm, D; Strasser, D; Zajfman, D

2009-01-01

A simple mass selection technique which allows one to clean a keV ion beam of undesirable masses while stored in an Electrostatic Ion Beam Trap (EIBT) is described. The technique is based on the time-of-flight principle and takes advantage of the long storage times and self-bunching that are possible in this type of traps (self bunching being the effect that keeps ions of the same mass bunched in spite of their finite distributions of velocities and trajectories). As the oscillation period is proportional to the square root of the ion mass, bunches containing ions of different masses will separate in space with increasing storage time and can be kicked out by a pulsed deflector mounted inside the trap. A mass selector of this type has been implemented successfully in an EIBT connected to an Even-Lavie supersonic expansion source and is routinely used in ongoing cluster experiments.

Suppression of Stimulated Brillouin Scattering in multiple-ion species inertial confinement fusion Hohlraum Plasmas

International Nuclear Information System (INIS)

Neumayer, P

2007-01-01

A long-standing problem in the field of laser-plasma interactions is to successfully employ multiple-ion species plasmas to reduce stimulated Brillouin scattering (SBS) in inertial confinement fusion (ICF) hohlraum conditions. Multiple-ion species increase significantly the linear Landau damping for acoustic waves. Consequently, recent hohlraum designs for indirect-drive ignition on the National Ignition Facility investigate wall liner material options so that the liner gain for parametric instabilities will be below threshold for the onset SBS. Although the effect of two-ion species plasmas on Landau damping has been directly observed with Thomson scattering, early experiments on SBS in these plasmas have suffered from competing non-linear effects or laser beam filamentation. In this study, a reduction of SBS scattering to below the percent level has been observed in hohlraums at Omega that emulate the plasma conditions in an indirect drive ICF experiments. These experiments have measured the laser-plasma interaction processes in ignition-relevant high-electron temperature regime demonstrating Landau damping as a controlling process for SBS. The hohlraums have been filled with various fractions of CO 2 and C 3 H 8 varying the ratio of the light (H) to heavy (C and O) ion density from 0 to 2.6. They have been heated by 14.5 kJ of 351-nm light, thus increasing progressively Landau damping by an order of magnitude at constant electron density and temperature. A delayed 351-nm interaction beam, spatially smoothed to produce a 200-(micro)m laser spot at best focus, has propagated along the axis of the hohlraum. The backscattered light, both into the lens and outside, the transmitted light through the hohlraum plasma and the radiation temperature of the hohlraum has been measured. For ignition relevant laser intensities (3-9 10 14 Wcm -2 ), we find that the SBS reflectivity scales as predicted with Landau damping from >30% to <1%. Simultaneously, the hohlraum radiation

Role of Fault Attributions and Other Factors in Adults' Attitudes Toward Hypothetical Children With an Undesirable Characteristic.

Science.gov (United States)

Wadian, Taylor W; Sonnentag, Tammy L; Jones, Tucker L; Barnett, Mark A

2018-01-01

A total of 184 adults read descriptions of six hypothetical children with various undesirable characteristics (i.e., being extremely overweight, extremely aggressive, extremely shy, a poor student, a poor athlete, displaying symptoms of attention deficit hyperactivity disorder). Following each description, the participants were asked to rate how much they disagree or agree that the child, the child's parents, and the child's biological condition (i.e., "something wrong inside the child's body or brain") are at fault for the onset and the perpetuation of the undesirable characteristic. In addition, the participants were asked to rate their attitude toward each child using a 100-point "feeling thermometer." Analyses of the participants' various fault attribution ratings revealed that they tended to agree more strongly that a child's parents and his/her biological condition are at fault for the onset and the perpetuation of the child's undesirable characteristic than is the child him/herself. Despite the participants' reluctance to blame a hypothetical child for his/her undesirable characteristic, regression analyses revealed that, in general, the more they blamed the child for the onset of his/her undesirable characteristic, the more negative their attitude was toward the child. However, the participants' ratings of the extent to which the child's parents or biological condition are at fault for the onset and the perpetuation of the child's undesirable characteristic were not found to be associated with their attitude toward any of the children. Similarities and differences between the present findings and those reported in prior studies involving younger individuals are addressed.

Adjustable liquid aperture to eliminate undesirable light in holographic projection.

Science.gov (United States)

Wang, Di; Liu, Chao; Li, Lei; Zhou, Xin; Wang, Qiong-Hua

2016-02-08

In this paper, we propose an adjustable liquid aperture to eliminate the undesirable light in a holographic projection. The aperture is based on hydrodynamic actuation. A chamber is formed with a cylindrical tube. A black droplet is filled in the sidewall of the cylinder tube and the outside space is the transparent oil which is immiscible with the black droplet. An ultrathin glass sheet is attached on the bottom substrate of the device and a black shading film is secured to the central area of the glass sheet. By changing the volume of the black droplet, the black droplet will move to the middle or sidewall due to hydrodynamic actuation, so the device can be used as an adjustable aperture. A divergent spherical wave and a solid lens are used to separate the focus planes of the reconstructed image and diffraction beams induced by the liquid crystal on silicon in the holographic projection. Then the aperture is used to eliminate the diffraction beams by adjusting the size of the liquid aperture and the holographic projection does not have undesirable light.

Temperature screening effect in two-ion species Pfirsch--Schlueter transport

International Nuclear Information System (INIS)

Tsang, K.T.; Crume, E.C.

1976-04-01

The particle and heat flux problems were solved in the collisional or Pfirsch-Schluter regime for a two-ion species tokamak plasma using a kinetic approach with exact Fokker-Planck collision operators. These solutions are appropriate for analyzing the behavior of impurities in the low temperature plasma edge region where impurities first enter the plasma from the outside. One finds that low charge states of low mass impurities can be screened effectively from further penetration of the plasma

Anode plasma dynamics in an extraction applied-B ion diode: effects on divergence, ion species and parasitic load

International Nuclear Information System (INIS)

Greenly, J.B.; Appartaim, R.K.; Olson, J.C.

1996-01-01

Analysis of data from the LION (1.2 MV, 300 kA, 40 ns) extraction applied-B diode allows a number of inferences regarding the effect of anode plasma dynamics on ion beam divergence, ion species composition, and diode impedance and power coupling. The two dominant features of anode plasma dynamics observed on LION are (1) plasma expansion away from the solid anode surface and into the accelerating gap during the beam pulse, and (2) evolution of the composition of the plasma during the pulse. The data presented in this paper characterize the plasma expansion, and suggest a possible picture of the mechanism of the plasma dynamics that could produce these basic features. (J.U.). 2 figs., 5 refs

Anode plasma dynamics in an extraction applied-B ion diode: effects on divergence, ion species and parasitic load

Energy Technology Data Exchange (ETDEWEB)

Greenly, J B; Appartaim, R K; Olson, J C [Cornell Univ., Ithaca, NY (United States). Lab. of Plasma Studies

1997-12-31

Analysis of data from the LION (1.2 MV, 300 kA, 40 ns) extraction applied-B diode allows a number of inferences regarding the effect of anode plasma dynamics on ion beam divergence, ion species composition, and diode impedance and power coupling. The two dominant features of anode plasma dynamics observed on LION are (1) plasma expansion away from the solid anode surface and into the accelerating gap during the beam pulse, and (2) evolution of the composition of the plasma during the pulse. The data presented in this paper characterize the plasma expansion, and suggest a possible picture of the mechanism of the plasma dynamics that could produce these basic features. (J.U.). 2 figs., 5 refs.

Comparing the Richtmyer-Meshkov instability of thermal and ion-species interfaces in two-fluid plasmas

Science.gov (United States)

Wheatley, Vincent; Bond, Daryl; Li, Yuan; Samtaney, Ravi; Pullin, Dale

2017-11-01

The Richtmyer-Meshkov instability (RMI) of a shock accelerated perturbed density interface is important in both inertial confinement fusion and astrophysics, where the materials involved are typically in the plasma state. Initial density interfaces can be due to either temperature or ion-species discontinuities. If the Atwood number of the interfaces and specific heat ratios of the fluids are matched, these two cases behave similarly when modeled using the equations of either hydrodynamics or magnetohydrodynamics. In the two-fluid ion-electron plasma model, however, there is a significant difference between them: In the thermal interface case, there is a discontinuity in electron density that is also subject to the RMI, while for the ion-species interface case there is not. It will be shown via ideal two-fluid plasma simulations that this causes substantial differences in the dynamics of the flow between the two cases. This work was partially supported by the KAUST Office of Sponsored Research under Award URF/1/2162-01.

Redox Species-Based Electrolytes for Advanced Rechargeable Lithium Ion Batteries

KAUST Repository

Ming, Jun

2016-08-15

Seeking high-capacity cathodes has become an intensive effort in lithium ion battery research; however, the low energy density still remains a major issue for sustainable handheld devices and vehicles. Herein, we present a new strategy of integrating a redox species-based electrolyte in batteries to boost their performance. Taking the olivine LiFePO4-based battery as an example, the incorporation of redox species (i.e., polysulfide of Li2S8) in the electrolyte results in much lower polarization and superior stability, where the dissociated Li+/Sx2– can significantly speed up the lithium diffusion. More importantly, the presence of the S82–/S2– redox reaction further contributes extra capacity, making a completely new LiFePO4/Li2Sx hybrid battery with a high energy density of 1124 Wh kgcathode–1 and a capacity of 442 mAh gcathode–1. The marriage of appropriate redox species in an electrolyte for a rechargeable battery is an efficient and scalable approach for obtaining higher energy density storage devices.

The effect of copper ions, aluminium ions and their mixtures on separation of pectin from the sugar beet juice

Directory of Open Access Journals (Sweden)

Kuljanin Tatjana A.

2013-01-01

Full Text Available In sugar industry there is a problem of the presence of undesirable macromolecules compounds such as pectin in sugar beet juice. The affinity of calcium ions commonly used in the sugar industry for the removal of pectin from the sugar beet juice is relatively small. Coagulation and precipitation of pectin can be performed by process of discharging that is chemically induced. Compounds with di- and trivalent cations such as pure CuSO4, Al2(SO43 or their mixtures can be applied for clarification of pectin colloidal systems. According to data from the order of pectin selectivity to divalent metal ions, Cu2+ ions are the first order of ion binding. Also, aluminum sulfate is commonly used in the waste water treatment. Two model solutions of pectin whose concentration corresponds to the concentration of these macromolecules in sugar beet juice (0.1% w/w are investigated. Using a method of measuring zeta potential, it was proven for both investigated pectin that fewer quantities of Cu2+ ions compared to the values of Al3+ ions are needed to reach zero zeta potential. In all the investigated coagulants and their mixtures, zeta potential has changed the sign. In experiments with mixtures has been shown that pure salts showed better coagulation properties. The reduced strength of binding of cations in the case of most of the applied mixture of Cu2+ and Al3+ ions, can be explained by the mutual competition of these ions for the adsorption site (COO- groups on the surface of macromolecules. Mixture with approximately equal shares of ions Cu2+ and Al3+ had the most unfavorable coagulation ability (ion antagonism. Mechanism of discharge as well as the model of double electric layer surrounding pectin macromolecules in the presence of mixtures of Cu2+ and Al3+ ions are suggested. However, due to possible undesirable effects of CuSO4 on food processing, Al2(SO43 is proposed instead of traditional coagulant CaO, not only because of lower consumptions of

The undesirable effects of neuromuscular blocking drugs

DEFF Research Database (Denmark)

Claudius, C; Garvey, L H; Viby-Mogensen, J

2009-01-01

Neuromuscular blocking drugs are designed to bind to the nicotinic receptor at the neuromuscular junction. However, they also interact with other acetylcholine receptors in the body. Binding to these receptors causes adverse effects that vary with the specificity for the cholinergic receptor...... in question. Moreover, all neuromuscular blocking drugs may cause hypersensitivity reactions. Often the symptoms are mild and self-limiting but massive histamine release can cause systematic reactions with circulatory and respiratory symptoms and signs. At the end of anaesthesia, no residual effect...... of a neuromuscular blocking drug should be present. However, the huge variability in response to neuromuscular blocking drugs makes it impossible to predict which patient will suffer postoperative residual curarization. This article discusses the undesirable effects of the currently available neuromuscular blocking...

Rice growing farmers efficiency measurement using a slack based interval DEA model with undesirable outputs

Science.gov (United States)

Khan, Sahubar Ali Mohd. Nadhar; Ramli, Razamin; Baten, M. D. Azizul

2017-11-01

In recent years eco-efficiency which considers the effect of production process on environment in determining the efficiency of firms have gained traction and a lot of attention. Rice farming is one of such production processes which typically produces two types of outputs which are economic desirable as well as environmentally undesirable. In efficiency analysis, these undesirable outputs cannot be ignored and need to be included in the model to obtain the actual estimation of firm's efficiency. There are numerous approaches that have been used in data envelopment analysis (DEA) literature to account for undesirable outputs of which directional distance function (DDF) approach is the most widely used as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, slack based DDF DEA approaches considers the output shortfalls and input excess in determining efficiency. In situations when data uncertainty is present, the deterministic DEA model is not suitable to be used as the effects of uncertain data will not be considered. In this case, it has been found that interval data approach is suitable to account for data uncertainty as it is much simpler to model and need less information regarding the underlying data distribution and membership function. The proposed model uses an enhanced DEA model which is based on DDF approach and incorporates slack based measure to determine efficiency in the presence of undesirable factors and data uncertainty. Interval data approach was used to estimate the values of inputs, undesirable outputs and desirable outputs. Two separate slack based interval DEA models were constructed for optimistic and pessimistic scenarios. The developed model was used to determine rice farmers efficiency from Kepala Batas, Kedah. The obtained results were later compared to the results obtained using a deterministic DDF DEA model. The study found that 15 out of 30 farmers are efficient in all cases. It

Analysis of intensities of positive and negative ion species from silicon dioxide films using time-of-flight secondary ion mass spectrometry and electronegativity of fragments

International Nuclear Information System (INIS)

Chiba, Kiyoshi

2010-01-01

Intensities of positive and negative ion species emitted from thermally oxidized and plasma-enhanced chemical vapor deposited (PECVD) SiO 2 films were analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS) and the Saha-Boltzmann equation. Intensities of positive and negative secondary ion species were normalized to those of 28 Si + and 28 Si - ions, respectively, and an effective temperature of approximately (7.2 ± 0.1) x 10 3 K of the sputtered region bombarded with pulsed 22 kV Au 3 + primary ions was determined. Intensity spectra showed polarity dependence on both n and m values of Si n O m fragments, and a slight shift to negative polarity for PECVD SiO 2 compared to thermally oxidized SiO 2 films. By dividing the intensity ratios of negative-to-positive ions for PECVD SiO 2 by those for thermally oxidized SiO 2 films to cancel statistical factors, the difference in absolute electronegativity (half the sum of ionization potential and electron affinity of fragments) between both films was obtained. An increase in electronegativity for SiO m (m = 1, 2) and Si 2 O m (m = 1-4) fragments for PECVD SiO 2 films compared to thermally oxidized films was obtained to be 0.1-0.2 Pauling units, indicating a more covalent nature of Si-O bonds for PECVD SiO 2 films compared to the thermally oxidized SiO 2 films.

An Assessment of the Impact of Climate Change on Plant Species ...

African Journals Online (AJOL)

Lazie

Abstract. This study assesses the effects of climate change on vegetative species diversity ... and mitigation strategies that are ecosystem and species specific. .... seasonality and values below detection limit. ... Pre-whitening is the process of removing undesirable autocorrelations ..... vegetation, carbon and fire in California.

Dynamic behaviour of interphases and its implication on high-energy-density cathode materials in lithium-ion batteries

Science.gov (United States)

Li, Wangda; Dolocan, Andrei; Oh, Pilgun; Celio, Hugo; Park, Suhyeon; Cho, Jaephil; Manthiram, Arumugam

2017-01-01

Undesired electrode–electrolyte interactions prevent the use of many high-energy-density cathode materials in practical lithium-ion batteries. Efforts to address their limited service life have predominantly focused on the active electrode materials and electrolytes. Here an advanced three-dimensional chemical and imaging analysis on a model material, the nickel-rich layered lithium transition-metal oxide, reveals the dynamic behaviour of cathode interphases driven by conductive carbon additives (carbon black) in a common nonaqueous electrolyte. Region-of-interest sensitive secondary-ion mass spectrometry shows that a cathode-electrolyte interphase, initially formed on carbon black with no electrochemical bias applied, readily passivates the cathode particles through mutual exchange of surface species. By tuning the interphase thickness, we demonstrate its robustness in suppressing the deterioration of the electrode/electrolyte interface during high-voltage cell operation. Our results provide insights on the formation and evolution of cathode interphases, facilitating development of in situ surface protection on high-energy-density cathode materials in lithium-based batteries. PMID:28443608

On the interpretation of different flow vectors of different ion species in the magnetospheric boundary layer

International Nuclear Information System (INIS)

Lundin, R.; Stasiewicz, K.; Hultqvist, B.

1986-05-01

Recent measurements of the ion composition in the magnetospheric boundary layer indicate that the boundary layer may contain clouds of magnetosheath plasma which are gradually becoming mixed with the magnetospheric plasma. A significant difference between flow vectors of different ion species (ca50-100 km/s) implies that an ideal MHD equation E+VxB=0, does not describe the macroscopic plasma flow inside such inhomogeneities. An analysis based on the first order drift theory indicates that gradients of the partial ion pressure and of the magnetic field could induce differential ion drifts comparable in magnitude to the electric drift velocity. We discuss some implications of these results on the physics of solar wind-magnetosphere interactions. (authors)

Studies on the surface modification of TiN coatings using MEVVA ion implantation with selected metallic species

International Nuclear Information System (INIS)

Ward, L.P.; Purushotham, K.P.; Manory, R.R.

2016-01-01

Highlights: • Reduced surface roughness was observed after ion implantation. • W implantation increased residual stress. • Reduced friction and wear accompanied Mo implantation. • Mo implanted layer was more resistant to breakdown during wear testing. • Ion implantation effects can be complex on various implanting species properties. - Abstract: Improvement in the performance of TiN coatings can be achieved using surface modification techniques such as ion implantation. In the present study, physical vapor deposited (PVD) TiN coatings were implanted with Cr, Zr, Nb, Mo and W using the metal evaporation vacuum arc (MEVVA) technique at a constant nominal dose of 4 × 10 16 ions cm −2 for all species. The samples were characterized before and after implantation, using Rutherford backscattering (RBS), glancing incident angle X-ray diffraction (GIXRD), atomic force microscopy (AFM) and optical microscopy. Friction and wear studies were performed under dry sliding conditions using a pin-on-disc CSEM Tribometer at 1 N load and 450 m sliding distance. A reduction in the grain size and surface roughness was observed after implantation with all five species. Little variation was observed in the residual stress values for all implanted TiN coatings, except for W implanted TiN which showed a pronounced increase in compressive residual stress. Mo-implanted samples showed a lower coefficient of friction and higher resistance to breakdown during the initial stages of testing than as-received samples. Significant reduction in wear rate was observed after implanting with Zr and Mo ions compared with unimplanted TiN. The presence of the Ti 2 N phase was observed with Cr implantation.

Equilibrium of field reversed configurations with rotation. II. One space dimension and many ion species

International Nuclear Information System (INIS)

Qerushi, Artan; Rostoker, Norman

2002-01-01

In a previous paper [N. Rostoker and A. Qerushi, Phys. Plasmas 9, 3057 (2002)] it was shown that a complete description of equilibria of field reversed configurations with rotation can be obtained by solving a generalized Grad-Shafranov equation for the flux function. In this paper we show how to solve this equation in the case of one space dimension and many ion species. The following fusion fuels are considered: D-T, D-He 3 , and p-B 11 . Using a Green's function the generalized Grad-Shafranov equation is converted to an equivalent integral equation. The integral equation can be solved by iteration. Approximate analytic solutions for a plasma with many ion species are found. They are used as starting trial functions of the iterations. They turn out to be so close to the true solutions that only a few iterations are needed

Functional implications of species differences in the size and morphology of the isthmo optic nucleus (ION in birds.

Directory of Open Access Journals (Sweden)

Cristián Gutiérrez-Ibáñez

Full Text Available In birds, there is a retinofugal projection from the brain to the retina originating from the isthmo optic nucleus (ION in the midbrain. Despite a large number of anatomical, physiological and histochemical studies, the function of this retinofugal system remains unclear. Several functions have been proposed including: gaze stabilization, pecking behavior, dark adaptation, shifting attention, and detection of aerial predators. This nucleus varies in size and organization among some species, but the relative size and morphology of the ION has not been systematically studied. Here, we present a comparison of the relative size and morphology of the ION in 81 species of birds, representing 17 different orders. Our results show that several orders of birds, besides those previously reported, have a large, well-organized ION, including: hummingbirds, woodpeckers, coots and allies, and kingfishers. At the other end of the spectrum, parrots, herons, waterfowl, owls and diurnal raptors have relatively small ION volumes. ION also appears to be absent or unrecognizable is several taxa, including one of the basal avian groups, the tinamous, which suggests that the ION may have evolved only in the more modern group of birds, Neognathae. Finally, we demonstrate that evolutionary changes in the relative size and the cytoarchitectonic organization of ION have occurred largely independent of phylogeny. The large relative size of the ION in orders with very different lifestyles and feeding behaviors suggest there is no clear association with pecking behavior or predator detection. Instead, our results suggest that the ION is more complex and enlarged in birds that have eyes that are emmetropic in some parts of the visual field and myopic in others. We therefore posit that the ION is involved in switching attention between two parts of the retina i.e. from an emmetropic to a myopic part of the retina.

The diffusion properties of ion implanted species in selected target materials

International Nuclear Information System (INIS)

Alton, G.D.; Dellwo, J.; Carter, H.K.; Kormicki, J.; Bartolo, G. di; Batchelder, J.C.; Breitenbach, J.; Chediak, J.A.; Jentoff-Nilsen, K.; Ichikawa, S.

1995-01-01

Experiments important to the future success of the Holifield Radioactive Ion Beam Facility (HRIBF) are in progress at the Oak Ridge National Laboratory which are designed to select the most appropriate target material for generating a particular radioactive ion beam (RIB). The 25-MV HHIRF tandem accelerator is used to implant stable complements of interesting radioactive elements into refractory targets mounted in a high-temperature FEBIAD ion source which is open-quotes on-lineclose quotes at the UNISOR facility. The intensity versus time of implanted species, which diffuse from the high-temperature target material (∼1700 degrees C) and are ionized in the FEBIAD ion source, is used to determine release times for a particular projectile/target material combination. From such release data, diffusion coefficients can be derived by fitting the theoretical results obtained by computational solution of Fick's second equation to experimental data. The diffusion coefficient can be used subsequently to predict the release properties of the particular element from the same material in other target geometries and at other temperatures, provided that the activation energy is also known. Diffusion coefficients for Cl implanted into and diffused from CeS and Zr 5 Si 3 and As, Br, and Se implanted into and diffused from Zr 5 Ge 3 have been derived from the resulting intensity versus time profiles. Brief descriptions of the experimental apparatus and procedures utilized in the present experiments and plans for future related experiments are presented

Ion optics of RHIC EBIS

Energy Technology Data Exchange (ETDEWEB)

Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Okamura, M.; Raparia, D.; Ritter, J.; Tan, Y.; Kuznetsov, G.

2011-09-10

RHIC EBIS has been commissioned to operate as a versatile ion source on RHIC injection facility supplying ion species from He to Au for Booster. Except for light gaseous elements RHIC EBIS employs ion injection from several external primary ion sources. With electrostatic optics fast switching from one ion species to another can be done on a pulse to pulse mode. The design of an ion optical structure and the results of simulations for different ion species are presented. In the choice of optical elements special attention was paid to spherical aberrations for high-current space charge dominated ion beams. The combination of a gridded lens and a magnet lens in LEBT provides flexibility of optical control for a wide range of ion species to satisfy acceptance parameters of RFQ. The results of ion transmission measurements are presented.

Evaluation of input output efficiency of oil field considering undesirable output —A case study of sandstone reservoir in Xinjiang oilfield

Science.gov (United States)

Zhang, Shuying; Wu, Xuquan; Li, Deshan; Xu, Yadong; Song, Shulin

2017-06-01

Based on the input and output data of sandstone reservoir in Xinjiang oilfield, the SBM-Undesirable model is used to study the technical efficiency of each block. Results show that: the model of SBM-undesirable to evaluate its efficiency and to avoid defects caused by traditional DEA model radial angle, improve the accuracy of the efficiency evaluation. by analyzing the projection of the oil blocks, we find that each block is in the negative external effects of input redundancy and output deficiency benefit and undesirable output, and there are greater differences in the production efficiency of each block; the way to improve the input-output efficiency of oilfield is to optimize the allocation of resources, reduce the undesirable output and increase the expected output.

Lanthanide ions (III) as sensitizers of melatonin oxidation in reaction mixtures providing reactive species of oxygen and nitrogen

Energy Technology Data Exchange (ETDEWEB)

Kaczmarek, Małgorzata, E-mail: mkaczmar@amu.edu.pl

2015-06-15

Chemiluminescence (CL) of the reactive systems providing strong oxidants (reactive species of oxygen and nitrogen) containing lanthanide ions (III) and melatonin, was studied. Kinetic curves of emission decay and spectral distributions of chemiluminescence were obtained. Analysis of differences in the intensity of chemiluminescence and CL spectra proved that excitation of Tb(III) and Dy(III) ions takes place with the energy transfer from the products of melatonin oxidation: N{sup 1}-acetyl-N{sup 2}-formyl-5-methoxykynuramine (AFMK) and N{sup 1}-acetyl-5-methoxykynuramine (AMK) to the lanthanide ions. In the system Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) a linear correlation was established between the integrated CL intensity and melatonin concent. - Highlights: • Chemiluminescence (CL) of melatonin (Mel) oxidation by reactive species of oxygen and nitrogen. • Tb(III) and Dy(III) ions as sensitizers of a melatonin oxidation process. • New CL method for determination of melatonin in pharmaceutical preparations based on CL of Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) system.

Elimination of carbon vacancies in 4H-SiC epi-layers by near-surface ion implantation: Influence of the ion species

Science.gov (United States)

Ayedh, H. M.; Hallén, A.; Svensson, B. G.

2015-11-01

The carbon vacancy (VC) is a prevailing point defect in high-purity 4H-SiC epitaxial layers, and it plays a decisive role in controlling the charge carrier lifetime. One concept of reducing the VC-concentration is based on carbon self-ion implantation in a near surface layer followed by thermal annealing. This leads to injection of carbon interstitials (Ci's) and annihilation of VC's in the epi-layer "bulk". Here, we show that the excess of C atoms introduced by the self-ion implantation plays a negligible role in the VC annihilation. Actually, employing normalized implantation conditions with respect to displaced C atoms, other heavier ions like Al and Si are found to be more efficient in annihilating VC's. Concentrations of VC below ˜2 × 1011 cm-3 can be reached already after annealing at 1400 °C, as monitored by deep-level transient spectroscopy. This corresponds to a reduction in the VC-concentration by about a factor of 40 relative to the as-grown state of the epi-layers studied. The negligible role of the implanted species itself can be understood from simulation results showing that the concentration of displaced C atoms exceeds the concentration of implanted species by two to three orders of magnitude. The higher efficiency for Al and Si ions is attributed to the generation of collision cascades with a sufficiently high energy density to promote Ci-clustering and reduce dynamic defect annealing. These Ci-related clusters will subsequently dissolve during the post-implant annealing giving rise to enhanced Ci injection. However, at annealing temperatures above 1500 °C, thermodynamic equilibrium conditions start to apply for the VC-concentration, which limit the net effect of the Ci injection, and a competition between the two processes occurs.

Experimental investigation of undesired stable equilibria in pumpkin shape super-pressure balloon designs

Science.gov (United States)

Schur, W. W.

2004-01-01

Excess in skin material of a pneumatic envelope beyond what is required for minimum enclosure of a gas bubble is a necessary but by no means sufficient condition for the existence of multiple equilibrium configurations for that pneumatic envelope. The very design of structurally efficient super-pressure balloons of the pumpkin shape type requires such excess. Undesired stable equilibria in pumpkin shape balloons have been observed on experimental pumpkin shape balloons. These configurations contain regions with stress levels far higher than those predicted for the cyclically symmetric design configuration under maximum pressurization. Successful designs of pumpkin shape super-pressure balloons do not allow such undesired stable equilibria under full pressurization. This work documents efforts made so far and describes efforts still underway by the National Aeronautics and Space Administration's Balloon Program Office to arrive on guidance on the design of pumpkin shape super-pressure balloons that guarantee full and proper deployment.

Ion beam monitoring

International Nuclear Information System (INIS)

McKinney, C.R.

1980-01-01

An ion beam analyzer is specified, having an ion source for generating ions of a sample to be analyzed, means for extracting the sample ions, means for focusing the sample ions into a beam, separation means positioned along the ion beam for selectively deflecting species of ions, and means for detecting the selected species of ions. According to the specification, the analyzer further comprises (a) means for disabling at least a portion of the separation means, such that the ion beam from the source remains undeflected; (b) means located along the path of the undeflected ion beam for sensing the sample ions; and (c) enabling means responsive to the sensing means for automatically re-enabling the separation means when the sample ions reach a predetermined intensity level. (author)

Undesirable Behaviors Elementary School Classroom Teachers Encounter in the Classroom and Their Reasons

Directory of Open Access Journals (Sweden)

E.G. Balcik

2011-12-01

Full Text Available The present study aims to determine how often elementary school teachers encounter undesirable behaviors in the classroom and what their thoughts regarding possible reasons of these behaviors are. The teachers’ opininon about the prevalence of these behaviors and their possible reasons were evaluated according to gender, marital status, level of class being taught, size of class being taught and it was tried to be determined if there were significant differences between variables. The measurement tool was applied to a total of 54 teachers at 5 schools in Gölcük district of the Kocaeli province. The data collection tool is composed of three sections. The first section is for establishing teachers’ personal information. In this study, as a data collection tool, a questionnaire was used. When preparing questions for the questionnaire, following the examination of resources available, the questionnaire prepared by Aksoy (1999 and used in the thesis study entitled “Classroom Management and Student Discipline in Elementary Schools of Ankara” and also used in the thesis study by Boyraz (2007 entitled “Discipline Problems that Candidate Teachers Servicing at Elementary Schools Encounter in the Classroom” was employed. Although the validity and reliability of the questionnaire was tested by Aksoy (1999 and Boyraz (2007, the reliability study for the questionnaire was retested and found to be 0,9. The questionnaire include 42 items. 19 of them are related to the reasons of undesirable behaviors observed in the classroom and 23 of them are related to undesirable behaviors observed in the classroom.

Effect of radical species density and ion bombardment during ashing of extreme ultralow-κ interlevel dielectric materials

International Nuclear Information System (INIS)

Worsley, M. A.; Bent, S. F.; Fuller, N. C. M.; Tai, T. L.; Doyle, J.; Rothwell, M.; Dalton, T.

2007-01-01

The significance of ion impact and radical species density on ash-induced modification of an extreme ultralow-κ interlevel dielectric (ILD) material (κ 2 and Ar/N 2 dual frequency capacitive discharges is determined by combining plasma diagnostics, modeling of the ion angular distribution function, and material characterization such as angle resolved x-ray photoelectron spectroscopy. Radical species density was determined by optical emission actinometry under the same conditions and in the same reactor in a previous study by the present authors. ILD modification is observed and correlated with changes in the plasma for a range of pressures (5-60 mTorr), bias powers (0-350 W), and percent Ar in the source gas (0%, 85%). For the Ar/O 2 discharge, extensive modification of the ILD sidewall was observed for significant ion scattering conditions, whereas minimal modification of the ILD sidewall was observed under conditions of minimal or no ion scattering. Further, for an identical increase in the O-radical density (∼ an order of magnitude), a different degree of modification was induced at the ILD trench bottom surface depending on whether pressure or percent Ar was used to increase the radical density. The different degrees of modification seemingly correlated with the relative changes in the ion current for increasing pressure or percent Ar. For the Ar/N 2 discharge, reduced damage of the ILD sidewall and trench bottom surfaces was observed for increasing pressure (increasing N-radical density) and decreasing ion current to both surfaces. It is, thus, proposed that the mechanism for modification of the porous ILD is dominated by the creation of reactive sites by ion impact under the present conditions. A detailed discussion of the results which support this proposal is presented

Light-regulated leaf expansion in two Populus species: dependence on developmentally controlled ion transport.

Science.gov (United States)

Stiles, Kari A; Van Volkenburgh, Elizabeth

2002-07-01

Leaf growth responses to light have been compared in two species of Populus, P. deltoides and P. trichocarpa. These species differ markedly in morphology, anatomy, and dependence on light during leaf expansion. Light stimulates the growth rate and acidification of cell walls in P. trichocarpa but not in P. deltoides, whereas leaves of P. deltoides maintain growth in the dark. Light-induced growth is promoted in P. deltoides when cells are provided 50-100 mM KCl. In both species, light initially depolarizes, then hyperpolarizes mesophyll plasma membranes. However, in the dark, the resting E(m) of mesophyll cells in P. deltoides, but not in P. trichocarpa, is relatively insensitive to decade changes in external [K+]. Results suggest that light-stimulated leaf growth depends on developmentally regulated cellular mechanisms controlling ion fluxes across the plasma membrane. These developmental differences underlie species-level differences in growth and physiological responses to the photoenvironment.

Ion Colliders

CERN Document Server

Fischer, W

2014-01-01

High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

Descriptors for ions and ion-pairs for use in linear free energy relationships.

Science.gov (United States)

Abraham, Michael H; Acree, William E

2016-01-22

The determination of Abraham descriptors for single ions is reviewed, and equations are given for the partition of single ions from water to a number of solvents. These ions include permanent anions and cations and ionic species such as carboxylic acid anions, phenoxide anions and protonated base cations. Descriptors for a large number of ions and ionic species are listed, and equations for the prediction of Abraham descriptors for ionic species are given. The application of descriptors for ions and ionic species to physicochemical processes is given; these are to water-solvent partitions, HPLC retention data, immobilised artificial membranes, the Finkelstein reaction and diffusion in water. Applications to biological processes include brain permeation, microsomal degradation of drugs, skin permeation and human intestinal absorption. The review concludes with a section on the determination of descriptors for ion-pairs. Copyright © 2015 Elsevier B.V. All rights reserved.

Ion mobility spectrometry-mass spectrometry (IMS-MS) for on- and offline analysis of atmospheric gas and aerosol species

Science.gov (United States)

Krechmer, Jordan E.; Groessl, Michael; Zhang, Xuan; Junninen, Heikki; Massoli, Paola; Lambe, Andrew T.; Kimmel, Joel R.; Cubison, Michael J.; Graf, Stephan; Lin, Ying-Hsuan; Budisulistiorini, Sri H.; Zhang, Haofei; Surratt, Jason D.; Knochenmuss, Richard; Jayne, John T.; Worsnop, Douglas R.; Jimenez, Jose-Luis; Canagaratna, Manjula R.

2016-07-01

Measurement techniques that provide molecular-level information are needed to elucidate the multiphase processes that produce secondary organic aerosol (SOA) species in the atmosphere. Here we demonstrate the application of ion mobility spectrometry-mass spectrometry (IMS-MS) to the simultaneous characterization of the elemental composition and molecular structures of organic species in the gas and particulate phases. Molecular ions of gas-phase organic species are measured online with IMS-MS after ionization with a custom-built nitrate chemical ionization (CI) source. This CI-IMS-MS technique is used to obtain time-resolved measurements (5 min) of highly oxidized organic molecules during the 2013 Southern Oxidant and Aerosol Study (SOAS) ambient field campaign in the forested SE US. The ambient IMS-MS signals are consistent with laboratory IMS-MS spectra obtained from single-component carboxylic acids and multicomponent mixtures of isoprene and monoterpene oxidation products. Mass-mobility correlations in the 2-D IMS-MS space provide a means of identifying ions with similar molecular structures within complex mass spectra and are used to separate and identify monoterpene oxidation products in the ambient data that are produced from different chemical pathways. Water-soluble organic carbon (WSOC) constituents of fine aerosol particles that are not resolvable with standard analytical separation methods, such as liquid chromatography (LC), are shown to be separable with IMS-MS coupled to an electrospray ionization (ESI) source. The capability to use ion mobility to differentiate between isomers is demonstrated for organosulfates derived from the reactive uptake of isomers of isoprene epoxydiols (IEPOX) onto wet acidic sulfate aerosol. Controlled fragmentation of precursor ions by collisionally induced dissociation (CID) in the transfer region between the IMS and the MS is used to validate MS peak assignments, elucidate structures of oligomers, and confirm the

Collective ion acceleration

International Nuclear Information System (INIS)

Godfrey, B.B.; Faehl, R.J.; Newberger, B.S.; Shanahan, W.R.; Thode, L.E.

1977-01-01

Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed

Hydrogen ion species analysis and related neutral beam injection power assessment in the Heliotron E neutral beam injection system

International Nuclear Information System (INIS)

Sano, Fumimichi; Obiki, Tokuhiro; Sasaki, Akihiko; Iiyoshi, Atsuo; Uo, Koji

1982-01-01

The hydrogen ion species in a Heliotron E neutral beam injection system of maximum electric power 6.3 MW were analyzed in order to assess the neutral beam power injected into the torus. The masimum p roton ratio of the cylindrical bucket type ion source used was observed to be more than 90 percent assuming that the angular divergences for the respective species in the beam are the same. The experimental data are compared with calculations using a particle balance model. The analysis indicates that the net injection power reaches nearly 2.7 MW at the optimal conditions of the system considering the geometrical limitation of the neutral beam path. (author)

Children's Perceptions of Hypothetical Peers With Undesirable Characteristics: Role of the Peers' Desire to Change, Source of Effort to Change, and Outcome.

Science.gov (United States)

Barnett, Mark A; Sonnentag, Tammy L; Wadian, Taylor W; Jones, Tucker L; Langley, Courtney A

2015-01-01

The present study, involving sixth- to eighth-grade students, is an extension of a prior investigation (Barnett, Livengood, Sonnentag, Barlett, & Witham, 2010) that examined children's perceptions of hypothetical peers with various undesirable characteristics. Results indicate that children's perceptions of hypothetical peers with an undesirable characteristic are influenced by the peers' desire to change, the source of effort to change, and the peers' success or failure in changing the characteristic. The children anticipated responding more favorably to peers who were successful in overcoming an undesirable characteristic than peers who were unsuccessful. Regardless of the peers' outcome, the children anticipated responding more favorably to peers who tried to change than peers who relied on the effort of adult authorities to motivate change. The children perceived successful peers as experiencing more positive affect than their unsuccessful counterparts, especially if the success was presented as a fulfillment of the peers' desire to change their undesirable characteristic. Finally, the children's ratings reflected the belief that, among peers who failed to change their undesirable characteristic, lacking the desire to change increases the relative likelihood that the characteristic will be permanent.

Elimination of carbon vacancies in 4H-SiC epi-layers by near-surface ion implantation: Influence of the ion species

Energy Technology Data Exchange (ETDEWEB)

Ayedh, H. M.; Svensson, B. G. [University of Oslo, Department of Physics/Center for Materials Science and Nanotechnology, P.O. Box 1048 Blindern, N-0316 Oslo (Norway); Hallén, A. [School of Information and Communication Technology (ICT), Royal Institute of Technology, SE-164 40 Kista-Stockholm (Sweden)

2015-11-07

The carbon vacancy (V{sub C}) is a prevailing point defect in high-purity 4H-SiC epitaxial layers, and it plays a decisive role in controlling the charge carrier lifetime. One concept of reducing the V{sub C}-concentration is based on carbon self-ion implantation in a near surface layer followed by thermal annealing. This leads to injection of carbon interstitials (C{sub i}'s) and annihilation of V{sub C}'s in the epi-layer “bulk”. Here, we show that the excess of C atoms introduced by the self-ion implantation plays a negligible role in the V{sub C} annihilation. Actually, employing normalized implantation conditions with respect to displaced C atoms, other heavier ions like Al and Si are found to be more efficient in annihilating V{sub C}'s. Concentrations of V{sub C} below ∼2 × 10{sup 11} cm{sup −3} can be reached already after annealing at 1400 °C, as monitored by deep-level transient spectroscopy. This corresponds to a reduction in the V{sub C}-concentration by about a factor of 40 relative to the as-grown state of the epi-layers studied. The negligible role of the implanted species itself can be understood from simulation results showing that the concentration of displaced C atoms exceeds the concentration of implanted species by two to three orders of magnitude. The higher efficiency for Al and Si ions is attributed to the generation of collision cascades with a sufficiently high energy density to promote C{sub i}-clustering and reduce dynamic defect annealing. These C{sub i}-related clusters will subsequently dissolve during the post-implant annealing giving rise to enhanced C{sub i} injection. However, at annealing temperatures above 1500 °C, thermodynamic equilibrium conditions start to apply for the V{sub C}-concentration, which limit the net effect of the C{sub i} injection, and a competition between the two processes occurs.

Elucidating the Performance Limitations of Lithium-ion Batteries due to Species and Charge Transport through Five Characteristic Parameters

Science.gov (United States)

Jiang, Fangming; Peng, Peng

2016-01-01

Underutilization due to performance limitations imposed by species and charge transports is one of the key issues that persist with various lithium-ion batteries. To elucidate the relevant mechanisms, two groups of characteristic parameters were proposed. The first group contains three characteristic time parameters, namely: (1) te, which characterizes the Li-ion transport rate in the electrolyte phase, (2) ts, characterizing the lithium diffusion rate in the solid active materials, and (3) tc, describing the local Li-ion depletion rate in electrolyte phase at the electrolyte/electrode interface due to electrochemical reactions. The second group contains two electric resistance parameters: Re and Rs, which represent respectively, the equivalent ionic transport resistance and the effective electronic transport resistance in the electrode. Electrochemical modeling and simulations to the discharge process of LiCoO2 cells reveal that: (1) if te, ts and tc are on the same order of magnitude, the species transports may not cause any performance limitations to the battery; (2) the underlying mechanisms of performance limitations due to thick electrode, high-rate operation, and large-sized active material particles as well as effects of charge transports are revealed. The findings may be used as quantitative guidelines in the development and design of more advanced Li-ion batteries. PMID:27599870

Numerical investigation of depth profiling capabilities of helium and neon ions in ion microscopy

Directory of Open Access Journals (Sweden)

Patrick Philipp

2016-11-01

Full Text Available The analysis of polymers by secondary ion mass spectrometry (SIMS has been a topic of interest for many years. In recent years, the primary ion species evolved from heavy monatomic ions to cluster and massive cluster primary ions in order to preserve a maximum of organic information. The progress in less-damaging sputtering goes along with a loss in lateral resolution for 2D and 3D imaging. By contrast the development of a mass spectrometer as an add-on tool for the helium ion microscope (HIM, which uses finely focussed He+ or Ne+ beams, allows for the analysis of secondary ions and small secondary cluster ions with unprecedented lateral resolution. Irradiation induced damage and depth profiling capabilities obtained with these light rare gas species have been far less investigated than ion species used classically in SIMS. In this paper we simulated the sputtering of multi-layered polymer samples using the BCA (binary collision approximation code SD_TRIM_SP to study preferential sputtering and atomic mixing in such samples up to a fluence of 1018 ions/cm2. Results show that helium primary ions are completely inappropriate for depth profiling applications with this kind of sample materials while results for neon are similar to argon. The latter is commonly used as primary ion species in SIMS. For the two heavier species, layers separated by 10 nm can be distinguished for impact energies of a few keV. These results are encouraging for 3D imaging applications where lateral and depth information are of importance.

Invasive species: Ocean ecosystem case studies for earth systems and environmental sciences

Science.gov (United States)

Schofield, Pam; Brown, Mary E.

2016-01-01

Marine species are increasingly transferred from areas where they are native to areas where they are not. Some nonnative species become invasive, causing undesirable impacts to environment, economy and/or human health. Nonnative marine species can be introduced through a variety of vectors, including shipping, trade, inland corridors (such as canals), and others. Effects of invasive marine species can be dramatic and irreversible. Case studies of four nonnative marine species are given (green crab, comb jelly, lionfish and Caulerpa algae).

Undesirable Effects of Media on Children: Why Limitation is Necessary?

Science.gov (United States)

Karaagac, Aysu Turkmen

2015-06-01

Pervasive media environment is a social problem shared by most of the countries around the world. Several studies have been performed to highlight the undesired effects of media on children. Some of these studies have focused on the time spent by children watching television, playing with computers or using mobile media devices while some others have tried to explain the associations between the obesity, postural abnormalities or psychological problems of children, and their media use. This article discusses the recent approaches to curb influence of media on children, and the importance of family media literacy education programs with particular relevance to developing countries.

Ion colliders

Energy Technology Data Exchange (ETDEWEB)

Fischer, W.

2011-12-01

Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions [77Asb1, 81Bou1]. The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

Ion colliders

International Nuclear Information System (INIS)

Fischer, W.

2010-01-01

Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions (77Asb1, 81Bou1). The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

Osmoregulation in larvae and juveniles of two recently separated Macrobrachium species: Expression patterns of ion transporter genes.

Science.gov (United States)

Boudour-Boucheker, Nesrine; Boulo, Viviane; Charmantier-Daures, Mireille; Anger, Klaus; Charmantier, Guy; Lorin-Nebel, Catherine

2016-05-01

In this comparative study, osmoregulatory mechanisms were analyzed in two closely related species of palaemonid shrimp from Brazil, Macrobrachium pantanalense and Macrobrachium amazonicum. A previous investigation showed that all postembryonic stages of M. pantanalense from inland waters of the Pantanal are able to hyper-osmoregulate in fresh water, while this species was not able to hypo-osmoregulate at high salinities. In M. amazonicum originating from the Amazon estuary, in contrast, all stages are able to hypo-osmoregulate, but only first-stage larvae, late juveniles and adults are able to hyper-osmoregulate in fresh water. The underlying molecular mechanisms of these physiological differences have not been known. We therefore investigated the expression patterns of three ion transporters (NKA α-subunit, VHA B-subunit and NHE3) following differential salinity acclimation in different ontogenetic stages (stage-V larvae, juveniles) of both species. Larval NKAα expression was at both salinities significantly higher in M. pantanalense than in M. amazonicum, whereas no difference was noted in juveniles. VHA was also more expressed in larvae of M. pantanalense than in those of M. amazonicum. When NHE3 expression is compared between the larvae of the two species, further salinity-related differences were observed, with generally higher expression in the inland species. Overall, a high expression of ion pumps in M. pantanalense suggests an evolutionary key role of these transporters in freshwater invasion. Copyright © 2016 Elsevier Inc. All rights reserved.

School Social Workers' Perceived Efficacy at Tasks Related to Curbing Suspension and Undesirable Behaviors

Science.gov (United States)

Teasley, Martell L.; Miller, Christina R.

2011-01-01

This study explores school social workers' perceptions of their ability to successfully engage in practice tasks that reduce the likelihood of school suspension and undesirable behaviors among racial and ethnic groups within diverse geographical locations (urban, suburban, and rural). Using survey research methods with a convenience sample, 201…

Separation of seven arsenic species by ion-pair and ion-exchange high performance liquid chromatography

DEFF Research Database (Denmark)

Larsen, Erik Huusfeldt; Hansen, Sven Hedegaard

1992-01-01

Arsenite, arsenate, monomethylarsonate, dimethylarsinate, arsenobetaine, arsenocholine and the tetramethylarsonium ion were subjected to ion-exchange and ion-pair reversed phase HPLC. The ion exchange method was superior in selectivity and time of analysis for the arsenic anions. The ammonium ions...... used for the ion-pair method only resulted in separation of some of the anionic arsenic compounds. Flame atomic absorption spectrometry was used for on-line arsenic-specific detection....

A nonlocal species concentration theory for diffusion and phase changes in electrode particles of lithium ion batteries

Science.gov (United States)

Zhang, Tao; Kamlah, Marc

2018-01-01

A nonlocal species concentration theory for diffusion and phase changes is introduced from a nonlocal free energy density. It can be applied, say, to electrode materials of lithium ion batteries. This theory incorporates two second-order partial differential equations involving second-order spatial derivatives of species concentration and an additional variable called nonlocal species concentration. Nonlocal species concentration theory can be interpreted as an extension of the Cahn-Hilliard theory. In principle, nonlocal effects beyond an infinitesimal neighborhood are taken into account. In this theory, the nonlocal free energy density is split into the penalty energy density and the variance energy density. The thickness of the interface between two phases in phase segregated states of a material is controlled by a normalized penalty energy coefficient and a characteristic interface length scale. We implemented the theory in COMSOL Multiphysics^{circledR } for a spherically symmetric boundary value problem of lithium insertion into a Li_xMn_2O_4 cathode material particle of a lithium ion battery. The two above-mentioned material parameters controlling the interface are determined for Li_xMn_2O_4 , and the interface evolution is studied. Comparison to the Cahn-Hilliard theory shows that nonlocal species concentration theory is superior when simulating problems where the dimensions of the microstructure such as phase boundaries are of the same order of magnitude as the problem size. This is typically the case in nanosized particles of phase-separating electrode materials. For example, the nonlocality of nonlocal species concentration theory turns out to make the interface of the local concentration field thinner than in Cahn-Hilliard theory.

Nectar sugars and amino acids in day- and night-flowering Nicotiana species are more strongly shaped by pollinators' preferences than organic acids and inorganic ions.

Science.gov (United States)

Tiedge, Kira; Lohaus, Gertrud

2017-01-01

Floral nectar contains mainly sugars but also amino acids, organic acids, inorganic ions and secondary compounds to attract pollinators. The genus Nicotiana exhibits great diversity among species in floral morphology, flowering time, nectar compositions, and predominant pollinators. We studied nectar samples of 20 Nicotiana species, composed equally of day- and night-flowering plants and attracting different groups of pollinators (e.g. hummingbirds, moths or bats) to investigate whether sugars, amino acids, organic acids and inorganic ions are influenced by pollinator preferences. Glucose, fructose and sucrose were the only sugars found in the nectar of all examined species. Sugar concentration of the nectar of day-flowering species was 20% higher and amino acid concentration was 2-3-fold higher compared to the nectar of night-flowering species. The sucrose-to-hexose ratio was significantly higher in night-flowering species and the relative share of sucrose based on the total sugar correlated with the flower tube length in the nocturnal species. Flowers of different tobacco species contained varying volumes of nectar which led to about 150-fold higher amounts of total sugar per flower in bat- or sunbird-pollinated species than in bee-pollinated or autogamous species. This difference was even higher for total amino acids per flower (up to 1000-fold). As a consequence, some Nicotiana species invest large amounts of organic nitrogen for certain pollinators. Higher concentrations of inorganic ions, predominantly anions, were found in nectar of night-flowering species. Therefore, higher anion concentrations were also associated with pollinator types active at night. Malate, the main organic acid, was present in all nectar samples but the concentration was not correlated with pollinator type. In conclusion, statistical analyses revealed that pollinator types have a stronger effect on nectar composition than phylogenetic relations. In this context, nectar sugars and amino

Nectar sugars and amino acids in day- and night-flowering Nicotiana species are more strongly shaped by pollinators’ preferences than organic acids and inorganic ions

Science.gov (United States)

Tiedge, Kira; Lohaus, Gertrud

2017-01-01

Floral nectar contains mainly sugars but also amino acids, organic acids, inorganic ions and secondary compounds to attract pollinators. The genus Nicotiana exhibits great diversity among species in floral morphology, flowering time, nectar compositions, and predominant pollinators. We studied nectar samples of 20 Nicotiana species, composed equally of day- and night-flowering plants and attracting different groups of pollinators (e.g. hummingbirds, moths or bats) to investigate whether sugars, amino acids, organic acids and inorganic ions are influenced by pollinator preferences. Glucose, fructose and sucrose were the only sugars found in the nectar of all examined species. Sugar concentration of the nectar of day-flowering species was 20% higher and amino acid concentration was 2-3-fold higher compared to the nectar of night-flowering species. The sucrose-to-hexose ratio was significantly higher in night-flowering species and the relative share of sucrose based on the total sugar correlated with the flower tube length in the nocturnal species. Flowers of different tobacco species contained varying volumes of nectar which led to about 150-fold higher amounts of total sugar per flower in bat- or sunbird-pollinated species than in bee-pollinated or autogamous species. This difference was even higher for total amino acids per flower (up to 1000-fold). As a consequence, some Nicotiana species invest large amounts of organic nitrogen for certain pollinators. Higher concentrations of inorganic ions, predominantly anions, were found in nectar of night-flowering species. Therefore, higher anion concentrations were also associated with pollinator types active at night. Malate, the main organic acid, was present in all nectar samples but the concentration was not correlated with pollinator type. In conclusion, statistical analyses revealed that pollinator types have a stronger effect on nectar composition than phylogenetic relations. In this context, nectar sugars and amino

Nectar sugars and amino acids in day- and night-flowering Nicotiana species are more strongly shaped by pollinators' preferences than organic acids and inorganic ions.

Directory of Open Access Journals (Sweden)

Kira Tiedge

Full Text Available Floral nectar contains mainly sugars but also amino acids, organic acids, inorganic ions and secondary compounds to attract pollinators. The genus Nicotiana exhibits great diversity among species in floral morphology, flowering time, nectar compositions, and predominant pollinators. We studied nectar samples of 20 Nicotiana species, composed equally of day- and night-flowering plants and attracting different groups of pollinators (e.g. hummingbirds, moths or bats to investigate whether sugars, amino acids, organic acids and inorganic ions are influenced by pollinator preferences. Glucose, fructose and sucrose were the only sugars found in the nectar of all examined species. Sugar concentration of the nectar of day-flowering species was 20% higher and amino acid concentration was 2-3-fold higher compared to the nectar of night-flowering species. The sucrose-to-hexose ratio was significantly higher in night-flowering species and the relative share of sucrose based on the total sugar correlated with the flower tube length in the nocturnal species. Flowers of different tobacco species contained varying volumes of nectar which led to about 150-fold higher amounts of total sugar per flower in bat- or sunbird-pollinated species than in bee-pollinated or autogamous species. This difference was even higher for total amino acids per flower (up to 1000-fold. As a consequence, some Nicotiana species invest large amounts of organic nitrogen for certain pollinators. Higher concentrations of inorganic ions, predominantly anions, were found in nectar of night-flowering species. Therefore, higher anion concentrations were also associated with pollinator types active at night. Malate, the main organic acid, was present in all nectar samples but the concentration was not correlated with pollinator type. In conclusion, statistical analyses revealed that pollinator types have a stronger effect on nectar composition than phylogenetic relations. In this context

The effect of copper ions, aluminum ions and their mixtures on separation of pectin from the sugar beet juice

OpenAIRE

Kuljanin, Tatjana A.; Mišljenović, Nevena M.; Koprivica, Gordana B.; Jevrić, Lidija R.; Grbić, Jasna P.

2013-01-01

In sugar industry there is a problem of the presence of undesirable macromolecules compounds such as pectin in sugar beet juice. The affinity of calcium ions commonly used in the sugar industry for the removal of pectin from the sugar beet juice is relatively small. Coagulation and precipitation of pectin can be performed by process of discharging that is chemically induced. Compounds with di- and trivalent cations such as pure CuSO4, Al2(SO4)3 or their mixtures can be applied for clari...

Array diagnostics, spatial resolution, and filtering of undesired radiation with the 3D reconstruction algorithm

DEFF Research Database (Denmark)

Cappellin, C.; Pivnenko, Sergey; Jørgensen, E.

2013-01-01

This paper focuses on three important features of the 3D reconstruction algorithm of DIATOOL: the identification of array elements improper functioning and failure, the obtainable spatial resolution of the reconstructed fields and currents, and the filtering of undesired radiation and scattering...

Multi-species Ionic Diffusion in Concrete with Account to Interaction Between Ions in the Pore Solution and the Cement Hydrates

DEFF Research Database (Denmark)

Johannesson, Björn

2007-01-01

results concerning the multi-species action during chloride penetration. In the model the chemical interaction between ions in solids and in pore solution is assumed governed by simple ion exchange processes only. The drawback using this approach is that the chemical part is lacking important physical...... relevance in terms of standard solubility thermodynamics. On the other hand the presented model is capable of accurately simulate the well documented peak behavior of the chloride profiles and the measured high content of calcium ions in pore solution under conditions when also chlorides is present...

Distribution of species and Ga–N bonds in silicon co-implanted with gallium and nitrogen ions

International Nuclear Information System (INIS)

Surodin, S. I.; Nikolitchev, D. E.; Kryukov, R. N.; Belov, A. I.; Korolev, D. S.; Mikhaylov, A. N.; Tetelbaum, D. I.

2016-01-01

The concentration profiles of species in silicon subjected to gallium and nitrogen co-implantation and subsequent annealing have been investigated by the method of X-ray photoelectron spectroscopy combined with the layer-by-layer ion etching of the implanted layer. It is shown that practically entire implanted gallium undergoes out-diffusion, but the preliminary implantation of nitrogen for the synthesis of a barrier SiN_x layer makes it possible to avoid the essential loss of gallium. In this case, about 14 % of implanted gallium bond to nitrogen. The obtained data are discussed from the viewpoint of the possibility of ion synthesis of GaN inclusions in silicon matrix.

Distribution of species and Ga–N bonds in silicon co-implanted with gallium and nitrogen ions

Energy Technology Data Exchange (ETDEWEB)

Surodin, S. I., E-mail: surodin.bsn@mail.ru; Nikolitchev, D. E.; Kryukov, R. N.; Belov, A. I.; Korolev, D. S.; Mikhaylov, A. N.; Tetelbaum, D. I., E-mail: tetelbaum@phys.unn.ru [Lobachevsky University, 23 Prospekt Gagarina, Nizhny Novgorod, 603950 (Russian Federation)

2016-06-17

The concentration profiles of species in silicon subjected to gallium and nitrogen co-implantation and subsequent annealing have been investigated by the method of X-ray photoelectron spectroscopy combined with the layer-by-layer ion etching of the implanted layer. It is shown that practically entire implanted gallium undergoes out-diffusion, but the preliminary implantation of nitrogen for the synthesis of a barrier SiN{sub x} layer makes it possible to avoid the essential loss of gallium. In this case, about 14 % of implanted gallium bond to nitrogen. The obtained data are discussed from the viewpoint of the possibility of ion synthesis of GaN inclusions in silicon matrix.

UNDESIRED REACTIONS AT THE UROGRAPHY IN THE CORRELATION OF THE IODIC AND THE NON-TODIC CONTRAST MEDIA

Directory of Open Access Journals (Sweden)

Rade R. Babić

2000-07-01

Full Text Available The paper analyzes the undesired reactions at 6053 urographies (IVU in thecorrelation of the iodic and the non-iodic contrast media (ICM.Depending on the allergological status the ICM (iodic or non-iodic is chosenfor the sake of carrying out an urographic examination as well as the necessarypremedication measures.The undesired reactions to the TCM are registered in 4,87% (1:20 TVU,namely in 5,6% (1:17 TVU to the iodic and in 2,39% (1:41 IVU to the non-iodicICM.At the intravenous application of the iodic ICM at the IVU the undesiredreactions are registered for2,4 times more often than at the application of the non-iodicICM.

A survey on the presence of undesirable botanical substances in feed in the European Union

Directory of Open Access Journals (Sweden)

van Raamsdonk LWD.

2009-01-01

Full Text Available Directive 2002/32/EC of the European Parliament and of the Council of 7 May 2002 on undesirable substances in animal feed lists a range of substances from botanical origin (weed seeds and additionally some chemical compounds directly originating from specific weeds. In order to examine the actual status of enforcement and of the present occurrence of these botanical substances, a survey was carried out. A questionnaire was sent to 103 laboratories, including official control labs from all member states of the European Union. The results, indicating the frequency of occurrence as far as reported, are compared to the publications of the EU Rapid Alert System for Food and Feed (RASFF. A total of 44 questionnaires was returned (42.7% from 22 member states. Ten member states predominantly from north-western Europe appeared to have an active monitoring of botanical undesirable substances. The questionnaire results did not indicate that the other member states enforce this part of Directive 2002/32/EC. Reports on the frequency of occurrence include: a few to 25-50% of the samples contain traces of ergot (8 member states, a few to 24% contain at least some traces of thorn apple (6 member states, zero to 17% contain some castor oil plant seeds (3 member states, zero to a few samples contain Crotalaria seeds (3 member states, and zero to 6% contain traces of Sareptian mustard (4 member states. One member state conducted extra surveillance since several cases of animal intoxications have been reported. In some cases a coincidence with undesirable botanical substances was found.

Using Ion Exchange Chromatography to Separate and Quantify Complex Ions

Science.gov (United States)

Johnson, Brian J.

2014-01-01

Ion exchange chromatography is an important technique in the separation of charged species, particularly in biological, inorganic, and environmental samples. In this experiment, students are supplied with a mixture of two substitution-inert complex ions. They separate the complexes by ion exchange chromatography using a "flash"…

Field quality evaluation of the superconducting magnets of the relativistic heavy ion collider

International Nuclear Information System (INIS)

Wei, J.; Gupta, R.C.; Jain, A.; Peggs, S.G.; Trahern, C.G.; Trbojevic, D.; Wanderer, P.

1995-01-01

In this paper, the authors first present the procedure established to evaluate the field quality, quench performance, and alignment of the superconducting magnets manufactured for the Relativistic Heavy Ion Collider (RHIC), and then discuss the strategies used to improve the field quality and to minimize undesirable effects by sorting the magnets. The field quality of the various RHIC magnets is briefly summarized

A Au82Si18 liquid metal field-ion emitter for the production of Si ions: fundamental properties and mechanisms

International Nuclear Information System (INIS)

Bischoff, L.; Mair, G.L.R.; Aidinis, C.J.; Londos, C.A.; Akhmadaliev, C.; Ganetsos, Th.

2004-01-01

Focused silicon beams are useful for direct write applications, e.g., lithography on silicon without the undesirable effect of substrate contamination. However, since pure silicon is not amenable to liquid metal ion source (LMIS) manufacture, a suitable alloy containing silicon has to be produced. This paper covers almost all fundamental aspects of a Au 82 Si 18 eutectic, including the most detailed beam mass spectra reported to date of a AuSi source. A finding worthy of note in this investigation, manifested in the behaviour of the ion extraction voltage with temperature, is the abnormal behaviour of the surface tension coefficient of the alloy with temperature. An important deduction from this work, however, concerns the mechanisms responsible for the creation of doubly charged ions: reasons of self-consistency indicate that while Si 2+ is directly field evaporated, Au 2+ must form by the post-ionization of Au + . Finally, two different mechanisms seem to co-exist, as far as the production of cluster ions is concerned. While for cluster ions containing only a few atoms some sort of surface field-ionization mechanism might be responsible for their creation, for larger clusters, a droplet break-up mechanism, possibly by ion capture, seems very likely

DEREGULATION, FINANCIAL CRISIS, AND BANK EFFICIENCY IN TAIWAN: AN ESTIMATION OF UNDESIRABLE OUTPUTS

OpenAIRE

Liao, Chang-Sheng

2018-01-01

Purpose- This study investigates the undesirable impacts of outputson bank efficiency and contributes to the literature by assessing howregulation policies and other events impact bank efficiency in Taiwan inregards to deregulation, financial crisis, and financial reform from 1993 to2011. Methodology- In order to effectively deal with both undesirableand desirable outputs, this study follows Seiford and Zhu (2002), who recommendusing the standard data envelopment analysis model to measure per...

Mass-selective isolation of ions stored in a quadrupole ion trap. A simulation study

Science.gov (United States)

March, Raymond E.; Londry, Frank A.; Alfred, Roland L.; Franklin, Anthony M.; Todd, John F. J.

1992-01-01

Trajectories of single ions stored in the quadrupole ion trap have been calculated using a simulation program described as the specific program for quadrupolar resonance (SPQR). Previously, the program has been used for the investigation of quadrupolar resonance excitation of ions with a static working point (or co-ordinates) in the stability diagram. The program has been modified to accommodate continuous d.c. and/or r.f. voltage ramps so as to permit calculation of ion trajectories while the working point is being changed. The modified program has been applied to the calculation of ion trajectories during ion isolation, or mass-selective storage, in the ion trap. The quadrupolar resonance excitation aspect of SPQR was not used in this study. Trajectories are displayed as temporal variations of ion kinetic energy, and axial and radial excursions from the centre of the ion trap. The working points of three ion species (m/z 144, 146 and 148), located initially on the qz, axis with qz [approximate] 0.12, were moved to the vicinity of the upper apex by a combination of r.f. and d.c. voltages applied in succession. Stable trajectories were maintained only for the ion species of m/z 146 for which the working point lay within this apex; the other ion species were ejected either radially or axially. The d.c. voltage was then reduced to zero so as to restore the working point of the isolated ion species to the qz axis. The amplitude of the r.f voltage was reduced to its initial value so as to retrieve the initial working point for m/z 146. The process extended over a real time of 2.9 ms, and was collision-free. The trajectory of the isolated ion was stable during this process; the ion species with m/z value lower than that of the target ion, that is, m/z 144, was ejected axially at the [beta]z = 1 boundary, while that with higher m/z value, that is, m/z 148, was ejected radially at the [beta]r = 0 boundary, as expected. The moderating effects of buffer gas were not taken

Development of Data Envelopment Analysis for the Performance Evaluation of Green Supply Chain with Undesirable Outputs

Directory of Open Access Journals (Sweden)

Alireza Alinezhad

2016-08-01

Full Text Available A fundamental problem is the use of DEA in multistep or multilevel processes such as supply chain, lack of attention to processes’ internal communications in a way that the recent studies on DEA in the context of serial processes have focused on closed systems that the outputs of one level become the inputs of the next level and none of the inputs enter the mediator process. The present study aimed to examine the general dimensions of an open multilevel process. Here, some of the data such as inputs and outputs are supposed to leave the system while other outputs turn into the inputs of the next level. The new inputs can enter the next level as well. We expand this mode for network structures. The overall performance of such a structure is considered as a weighted average of sectors’ performance or distinct steps. Therefore, this suggested model in this study, not only provides the possibility to evaluate the performance of the entire network, but creates the performance analysis for each of the sub-processes. On the other hand, considering the data with undesirable structure leads to more correct performance estimation. In the real world, all productive processes do not comprise desirable factors. Therefore, presenting a structure that is capable of taking into account the undesirable structure is of crucial importance. In this study, a new model in the DEA by network structure is offered that can analyze the performance considering undesirable factors.

A survey on the presence of undesirable botanical substances in feed in the European Union

NARCIS (Netherlands)

Raamsdonk, van L.W.D.; Vancutsem, J.; Jorgensen, J.S.

2009-01-01

Directive 2002/32/EC of the European Parliament and of the Council of 7 May 2002 on undesirable substances in animal feed lists a range of substances from botanical origin (weed seeds) and additionally some chemical compounds directly originating from specific weeds. In order to examine the actual

Variable eigenmode excitation in the beach heating of two-ion-species mirror plasmas

International Nuclear Information System (INIS)

Roberts, D.R.

1990-01-01

Variable eigenmode excitation scans of the ion species ratio of hydrogen-helium and hydrogen-deuterium plasmas has been examined in the bench-heating configuration of the Phaedrus-B central cell. m = -1 fields were selectively excited by a ''rotating-field'' antenna array at ω/Ω H = 0.8. The coupled wave energy propagates through a steep axial magnetic gradient into a region of strong ion-cyclotron resonance absorption which is located triangle z = 50cm from the antenna. Evidence of varied fast- and slow-wave eigenmode excitation and absorption, including variations in the radial profiles of waves magnetic field and plasma parameters, was observed during the scans. Optimal peak parameters in the plasma core, n e = 1.0 x 10 13 cm -3 , T eparallel = 20eV, T iparallel = 140eV, T iperpendicular = 450eV, and β = 0.2, were obtained for moderate helium or deuterium ion fractions (puffed n He /n e = n D /n e ∼ 0.25). These parameters exceed those obtained under the same conditions with ''pure'' hydrogen plasmas: n e = 7.0 x 10 12 cm -3 , T eparallel = 25eV, T iparallel = 80eV, T iperpendicular = 300eV, and β = 0.1. These variations are in agreement with those expected from antenna-eigenmode coupling considerations

Undesirable Behaviors Elementary School Classroom Teachers Encounter in the Classroom and Their Reasons

OpenAIRE

E.G. Balcik; S. Gulec

2011-01-01

The present study aims to determine how often elementary school teachers encounter undesirable behaviors in the classroom and what their thoughts regarding possible reasons of these behaviors are. The teachers’ opininon about the prevalence of these behaviors and their possible reasons were evaluated according to gender, marital status, level of class being taught, size of class being taught and it was tried to be determined if there were significant differences between variables. The measure...

Electron collector and ion species experiments on the LION extractor ion diode

International Nuclear Information System (INIS)

Rondeau, G.; Greenly, J.B.; Hammer, D.A.; Horioka, K.; Meyerhofer, D.D.

1987-01-01

Studies of the effects of an electron collector on the electron flow in an ion diode and on diode impedance history are being done with an extractor geometry ion diode (B/sub r/ magnetic insulation field) on the LION accelerator (1.5 MV, 4Ω, 40 ns). The collector is a flux-penetrable metal protrusion on the inner radius of the anode that collects electrons. This device increases the diode operating impedance particularly during the later part of the pulse when the diode impedance collapses without the collector. In the present set of experiments, several thin wires are inserted into the anode and allowed to protrude a few millimeters into the A-K gap. These wires are damaged by the electron flow during the pulse and by measuring the length of the remaining wire, the distance of the electron layer from the anode can be inferred. The ion current density is also measured in three radial locations across the diode, giving a measure, through the Child-Langmuir law, of the effective gap spacing between the anode and the electron sheath. A simple model is proposed to account for the scaling of ion current density with the diode voltage observed in the experiment

Productivity Growth-Accounting for Undesirable Outputs and Its Influencing Factors: The Case of China

Directory of Open Access Journals (Sweden)

Junfeng Zhang

2016-11-01

Full Text Available Presently, China’s social development is facing the dilemma of supporting economic growth and reducing emissions. Therefore, it is crucial to analyse productivity growth and examine its relationship with influencing factors in China. This study evaluated the total factor productivity (TFP growth of 30 provinces in China by adopting the Malmquist-Luenberger (ML productivity index and incorporating undesirable outputs from 2011–2014. Then, a Tobit regression model was employed to explore the factors that influence China’s TFP growth. The results show that the average annual growth of the Malmquist-Luenberger productivity index was lower than that of the traditional Malmquist (M productivity index growth during the research period. The findings reveal several key conclusions: First, the true TFP growth in China will be overestimated if undesirable outputs are ignored. Second, technical changes are the main contributor to TFP growth. Third, there are huge regional disparities of productivity growth in China. Fourth, coal intensity, environmental regulations, and industrial structure have significantly negative effects on productivity growth, while real per capita gross domestic product (GDP and foreign direct investment (FDI have strongly positive effects on productivity growth.

Pig herd monitoring and undesirable tripping and stepping prevention

DEFF Research Database (Denmark)

Gronskyte, Ruta; Clemmensen, Line Katrine Harder; Hviid, Marchen Sonja

2015-01-01

Humane handling and slaughter of livestock are of major concern in modern societies. Monitoring animal wellbeing in slaughterhouses is critical in preventing unnecessary stress and physical damage to livestock, which can also affect the meat quality. The goal of this study is to monitor pig herds...... at the slaughterhouse and identify undesirable events such as pigs tripping or stepping on each other. In this paper, we monitor pig behavior in color videos recorded during unloading from transportation trucks. We monitor the movement of a pig herd where the pigs enter and leave a surveyed area. The method is based...... on optical flow, which is not well explored for monitoring all types of animals, but is the method of choice for human crowd monitoring. We recommend using modified angular histograms to summarize the optical flow vectors. We show that the classification rate based on support vector machines is 93% of all...

A comparative analysis of China’s regional energy and emission performance: Which is the better way to deal with undesirable outputs?

International Nuclear Information System (INIS)

Wang Ke; Wei Yiming; Zhang Xian

2012-01-01

Measuring and improving the energy performance with considering emission constraints is an important issue for China’s energy conservation, pollutant emissions reduction and environment protection. This study utilizes several data envelopment analysis (DEA) based models to evaluate the total-factor energy and emission performance of China’s 30 regions within a joint production framework of considering desirable and undesirable outputs as well as separated energy and non-energy inputs. DEA window analysis is applied in this study to deal with cross-sectional and time-varying data, so as to measure the performance during the period of 2000–2009. Two treatments for undesirable outputs are combined with DEA models and the associated indicators for simplex energy performance and unified energy and emission performance measurement are proposed and compared. The evaluation results indicate that the treatment of undesirable outputs transformation is more appropriate for China’s regional energy and emission performance evaluation because it has stronger discriminating power and can provide more reasonable evaluation results that characterize China’s regions. The empirical result shows that east China has the highest and the most balanced energy and emission performance. The energy and emission performance of China remained stable during 2000–2003, decreased slightly during 2004–2006, and has continuously increased since 2007. - Highlights: ► We evaluate China’s regional energy and emission performance using DEA based models. ► We compare two undesirable outputs treatments according to the evaluation results. ► To treat undesirable outputs as inputs has weaker discriminating power in evaluation. ► Simplex energy performance, without environmental factors, is a biased evaluation. ► China’s energy and emission performance is approximately stable during study period.

Relationships between College Students' Credit Card Debt, Undesirable Academic Behaviors and Cognitions, and Academic Performance

Science.gov (United States)

Hogan, Eileen A.; Bryant, Sarah K.; Overymyer-Day, Leslie E.

2013-01-01

The acquisition of credit card debt by college students has long been a topic of concern. This study explores relationships among debt, undesirable academic behaviors and cognitions, and academic performance, through surveys of 338 students in a public university, replicating two past measures of credit card debt and creating new measures of…

The STABALID project: Risk analysis of stationary Li-ion batteries for power system applications

International Nuclear Information System (INIS)

Soares, F.J.; Carvalho, L.; Costa, I.C.; Iria, J.P.; Bodet, J.-M.; Jacinto, G.; Lecocq, A.; Roessner, J.; Caillard, B.; Salvi, O.

2015-01-01

This work presents a risk analysis performed to stationary Li-ion batteries within the framework of the STABALID project. The risk analysis had as main objective analysing the variety of hazards and dangerous situations that might be experienced by the battery during its life cycle and providing useful information on how to prevent or manage those undesired events. The first task of the risk analysis was the identification of all the hazards (or risks) that may arise during the battery life cycle. Afterwards, the hazards identified were mapped in the different stages of the battery life cycle and two analyses were performed for each stage: an internal problem analysis and an external peril analysis. For both, the dangerous phenomena and the undesirable events resulting from each hazard was evaluated in terms of probability of occurrence and severity. Then, a risk assessment was carried out according to a predefined risk matrix and a preliminary set of risk mitigation measures were proposed to reduce their probability of occurrence and/or their severity level. The results obtained show that it is possible to reduce the probability of occurrence/severity of all the risks associated to the battery life cycle to acceptable or tolerable levels. - Highlights: • Methodology for a detailed risk analysis of stationary Li-ion batteries. • Various hazards and dangerous situations are analysed with high detail. • Useful information on how to prevent or manage the undesired events is provided. • Measures to reduce probability of occurrence/severity of the risks are presented

Novel lanthanide doped micro- and mesoporous solids. Characterization of ion-host-interactions, species distribution and luminescence properties using time-resolved luminescence spectroscopy

International Nuclear Information System (INIS)

Gessner, Andre

2010-12-01

In this work lanthanide-doped microporous zeolites, microporous-mesoporous hybrid materials and mesoporous silicates were investigated regarding their luminescence properties and the ion-host-interactions using time-resolved luminescence spectroscopy. Thereby, time-resolved emission spectra (TRES) provide information in the wavelength and time domain. For the analysis of the TRES a broad set of analytic methods was applied and thus a corresponding ''toolbox'' developed. Fitting of the luminescence decays was performed with a discrete number of exponentials and supported by luminescence decay times distributions. Time-resolved area normalized emission spectra (TRANES), an advancement of TRES, could be used for the determination of the number of emissive lanthanide species in porous materials for the first time. Calculation of the decay-associated spectra (DAS) allowed the correlation of spectral information with luminescence decay times and thus delivered the luminescence spectra of the different europium species. For europium(III) we could use in addition the time-dependent asymmetry ratio and spectral evolution of the 5 D 0 - 7 F 0 -transition with time to obtain further information about the distribution of the lanthanide ions in the host material. Luminescence decay times and spectra allowed conclusions on the number of OH-oscillators in and the symmetry of the first coordination sphere. For the microporous and microporous-mesoporous materials were found different lanthanide species, which were characterized by the above mentioned methods. These lanthanide species can be found on different positions in the host material. One position is located deep in the pore system. Here, lanthanide ions are hardly accessible for water and mainly coordinated by framework oxygens. This results in long luminescence decay times and distorted coordination spheres. The second position can be found near or on the outer surface or in the mesopores. Lanthanide ions located here, are

reSpect: Software for Identification of High and Low Abundance Ion Species in Chimeric Tandem Mass Spectra

Science.gov (United States)

Shteynberg, David; Mendoza, Luis; Hoopmann, Michael R.; Sun, Zhi; Schmidt, Frank; Deutsch, Eric W.; Moritz, Robert L.

2015-11-01

Most shotgun proteomics data analysis workflows are based on the assumption that each fragment ion spectrum is explained by a single species of peptide ion isolated by the mass spectrometer; however, in reality mass spectrometers often isolate more than one peptide ion within the window of isolation that contribute to additional peptide fragment peaks in many spectra. We present a new tool called reSpect, implemented in the Trans-Proteomic Pipeline (TPP), which enables an iterative workflow whereby fragment ion peaks explained by a peptide ion identified in one round of sequence searching or spectral library search are attenuated based on the confidence of the identification, and then the altered spectrum is subjected to further rounds of searching. The reSpect tool is not implemented as a search engine, but rather as a post-search engine processing step where only fragment ion intensities are altered. This enables the application of any search engine combination in the iterations that follow. Thus, reSpect is compatible with all other protein sequence database search engines as well as peptide spectral library search engines that are supported by the TPP. We show that while some datasets are highly amenable to chimeric spectrum identification and lead to additional peptide identification boosts of over 30% with as many as four different peptide ions identified per spectrum, datasets with narrow precursor ion selection only benefit from such processing at the level of a few percent. We demonstrate a technique that facilitates the determination of the degree to which a dataset would benefit from chimeric spectrum analysis. The reSpect tool is free and open source, provided within the TPP and available at the TPP website.

The application of transition metal ion chromatography to the determination of elemental and radiochemical species in PWR primary coolant

International Nuclear Information System (INIS)

Bridle, D.A.; Brown, G.R.; Johnson, P.A.V.

1992-01-01

The accurate determination of both elemental and radiochemical transition metal corrosion products, particularly cobalt and nickel, in PWR coolants is necessary if the transport mechanisms and their role in the development of out-of-core radiation fields are to be fully understood. AEA Technology, Winfrith, has collaborated for several years with a number of PWR utilities in Europe, developing advanced sampling and analytical techniques for the determination of both soluble and insoluble corrosion products in primary coolant. The design and installation of continuously flowing isokinetic capillary modifications to the existing sampling systems has been shown to be an effective method of providing a low, but representative, sample flow from high pressure systems for on-line determination of corrosion product species. Transition metal ion chromatography coupled with gamma-spectrometry has been used to determine both insoluble and soluble elemental and radiochemical species in reactor coolant, with particular attention being given to the determination of soluble elemental cobalt at levels as low as 1 ng per kg. Soluble species were determined directly following their concentration from up to 1 litre of coolant. Insoluble species collected on 0.45 micron filter membranes, following filtration of up to 1500 litres of coolant, were solubilised by fusion with potassium hydrogen sulphate before the application of ion chromatography. In each case the eluant from the chromatographic column was collected and the radionuclides determined by gamma-spectrometry

Design study of primary ion provider for relativistic heavy ion collider electron beam ion source.

Science.gov (United States)

Kondo, K; Kanesue, T; Tamura, J; Okamura, M

2010-02-01

Brookhaven National Laboratory has developed the new preinjector system, electron beam ion source (EBIS) for relativistic heavy ion collider (RHIC) and National Aeronautics and Space Administration Space Radiation Laboratory. Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ion beam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented.

1+-n+ ECR ION SOURCE DEVELOPMENT TEST STAND

International Nuclear Information System (INIS)

Donald P. May

2006-01-01

A test stand for the investigation of 1+-n+ charge boosting using an ECR ion sources is currently being assembled at the Texas A and M Cyclotron Institute. The ultimate goal is to relate the charge-boosting of ions of stable species to possible charge-boosting of ions of radioactive species extracted from the diverse, low-charge-state ion sources developed for radioactive ion beams

reSpect: software for identification of high and low abundance ion species in chimeric tandem mass spectra.

Science.gov (United States)

Shteynberg, David; Mendoza, Luis; Hoopmann, Michael R; Sun, Zhi; Schmidt, Frank; Deutsch, Eric W; Moritz, Robert L

2015-11-01

Most shotgun proteomics data analysis workflows are based on the assumption that each fragment ion spectrum is explained by a single species of peptide ion isolated by the mass spectrometer; however, in reality mass spectrometers often isolate more than one peptide ion within the window of isolation that contribute to additional peptide fragment peaks in many spectra. We present a new tool called reSpect, implemented in the Trans-Proteomic Pipeline (TPP), which enables an iterative workflow whereby fragment ion peaks explained by a peptide ion identified in one round of sequence searching or spectral library search are attenuated based on the confidence of the identification, and then the altered spectrum is subjected to further rounds of searching. The reSpect tool is not implemented as a search engine, but rather as a post-search engine processing step where only fragment ion intensities are altered. This enables the application of any search engine combination in the iterations that follow. Thus, reSpect is compatible with all other protein sequence database search engines as well as peptide spectral library search engines that are supported by the TPP. We show that while some datasets are highly amenable to chimeric spectrum identification and lead to additional peptide identification boosts of over 30% with as many as four different peptide ions identified per spectrum, datasets with narrow precursor ion selection only benefit from such processing at the level of a few percent. We demonstrate a technique that facilitates the determination of the degree to which a dataset would benefit from chimeric spectrum analysis. The reSpect tool is free and open source, provided within the TPP and available at the TPP website. Graphical Abstract ᅟ.

Status report on electron cyclotron resonance ion sources at the Heavy Ion Medical Accelerator in Chiba

CERN Document Server

Kitagawa, A; Sekiguchi, M; Yamada, S; Jincho, K; Okada, T; Yamamoto, M; Hattori, T G; Biri, S; Baskaran, R; Sakata, T; Sawada, K; Uno, K

2000-01-01

The Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences (NIRS) is not only dedicated to cancer therapy, it is also utilized with various ion species for basic experiments of biomedical science, physics, chemistry, etc. Two electron cyclotron resonance (ECR) ion sources are installed for production of gaseous ions. One of them, the NIRS-ECR, is a 10 GHz ECR ion source, and is mainly operated to produce C/sup 4+/ ions for daily clinical treatment. This source realizes good reproducibility and reliability and it is easily operated. The other source, the NIRS-HEC, is an 18 GHz ECR ion source that is expected to produce heavier ion species. The output ion currents of the NIRS-ECR and the NIRS-HEC are 430e mu A for C/sup 4+/ and 1.1e mA for Ar/sup 8+/, respectively. (14 refs).

Focused Ion Beam Analysis of Banana Peel and Its Application for Arsenate Ion Removal

Directory of Open Access Journals (Sweden)

Jamil R. Memon

2015-06-01

Full Text Available Banana peel, a common fruit waste, has been investigated for its ability to remove arsenate ions from ground water as a function of pH, contact time, and initial metal ion concentration. Focused ion beam (FIB analysis revealed the internal morphology of the banana peels. Arsenate ions were entered into micropores of banana peel. pH was seen to have no effect on the sorption process. Retained species were eluted using 5 mL of 2 M H2SO4. The kinetics of sorption were observed to follow the pseudo first order rate equation. The sorption data followed Freundlich and D-R isotherms. The energy value obtained from the D-R isotherms indicated that the sorption was physical in nature for arsenate species. Our study has shown that banana peel has the ability to remove arsenate species from ground water samples.

Focused ion beam analysis of banana peel and its application for arsenate ion removal

International Nuclear Information System (INIS)

Memon, J.R.

2015-01-01

Banana peel, a common fruit waste, has been investigated for its ability to remove arsenate ions from ground water as a function of pH, contact time, and initial metal ion concentration. Focused ion beam (FIB) analysis revealed the internal morphology of the banana peels. Arsenate ions were entered into micropores of banana peel. pH was seen to have no effect on the sorption process. Retained species were eluted using 5 mL of 2 M H/sub 2/SO/sub 4/. The kinetics of sorption were observed to follow the pseudo first order rate equation. The sorption data followed Freundlich and D-R isotherms. The energy value obtained from the D-R isotherms indicated that the sorption was physical in nature for arsenate species. Our study has shown that banana peel has the ability to remove arsenate species from ground water samples. (author)

[Undesired treatment effects in behavior group therapy: Frequency and spectrum].

Science.gov (United States)

Linden, M; Walter, M; Fritz, K; Muschalla, B

2015-11-01

Psychotherapy not only has positive but also negative effects, which is especially true for group psychotherapy due to psychodynamic and interactional processes. Using the UE-G questionnaire 71 patients who participated in cognitive behavioral group psychotherapy reported on negative experiences in the context of the group therapy. The answers were then validated in a qualitative interview. Of the patients 98.6% reported about at least one negative experience and 43.7% about severe or extremely severe negative experiences. Most prominent was the induction of hopelessness and demoralization by what patients saw and heard from other patients in the group. Burdensome and therefore undesired treatment effects are regularly seen in group psychotherapy, because of treatment or patient related factors. In any case they must be taken into account during treatment, in the training of group psychotherapists and in quality control.

Ion-Ion Plasmas Produced by Electron Beams

Science.gov (United States)

Fernsler, R. F.; Leonhardt, D.; Walton, S. G.; Meger, R. A.

2001-10-01

The ability of plasmas to etch deep, small-scale features in materials is limited by localized charging of the features. The features charge because of the difference in electron and ion anisotropy, and thus one solution now being explored is to use ion-ion plasmas in place of electron-ion plasmas. Ion-ion plasmas are effectively electron-free and consist mainly of positive and negative ions. Since the two ion species behave similarly, localized charging is largely eliminated. However, the only way to produce ion-ion plasmas at low gas pressure is to convert electrons into negative ions through two-body attachment to neutrals. While the electron attachment rate is large at low electron temperatures (Te < 1 eV) in many of the halogen gases used for processing, these temperatures occur in most reactors only during the afterglow when the heating fields are turned off and the plasma is decaying. By contrast, Te is low nearly all the time in plasmas produced by electron beams, and therefore electron beams can potentially produce ion-ion plasmas continuously. The theory of ion-ion plasmas formed by pulsed electron beams is examined in this talk and compared with experimental results presented elsewhere [1]. Some general limitations of ion-ion plasmas, including relatively low flux levels, are discussed as well. [1] See the presentation by D. Leonhardt et al. at this conference.

Analysis of molecular species of triacylglycerols from vegetable oils containing fatty acids with non-methylene-interrupted double bonds, by HPLC in the silver-ion mode

Energy Technology Data Exchange (ETDEWEB)

Joh, Y.; Kim, S. [Dong A Univ., Pusan (Korea, Republic of)

1998-10-20

The possibilities for application of silver ion HPLC to analysis of the triacylglycerols containing conjugate trienoic acids and {Delta}{sup 5}-polymethylene-interrupted acids and proportions of triacylglycerol fractions obtained by silver-ion HPLC from the seed oil of Momordica charantia double bonds were examined, respectively. The triacylglycerols of seed oils containing conjugate trienoic acids such as {alpha}-eleostearic acid (C{sub 18:3 9c,11t,13t}) and punicic acid (C{sub 18:3} {sub 9c,11t,13c}) were resolved by silver-ion HPLC. Fractions were fractionated on the basis of the number and configuration of double bonds in the species, and the elution profile is quite different from that of the species comprising exclusively saturated and unsaturated fatty acids with methylene-interrupted double bonds ; for instance, the species (DT(c2)) composed of one dienoic acid and two conjugate trienoic acids eluted much earlier than the species (D{sub 2}T{sub c}) composed of two dienoic acids and one conjugate trienoic acid, in spite of having larger number of double bonds. This means that the interaction of conjugate double bonds with silver ions is weaker than that of methylene-interrupted double bonds, presumably because of the delocalization of {pi}-electrons in conjugate double bonds. In this instance, the strength of interaction of a conjugate trienoic double bond system with silver ions seemed to be between that of methylene-interrupted dienoic and monoenoic double bond systems. Triacylglycerols of the seeds of Ginkgo biloba have been resolved by HPLC in the silver-ion mode according to the number and position of double bonds. In this instance, the strength of interaction between the {pi}-electrons of double bonds in the fatty acyl residues and silver ions is in the order; C{sub 18:3{omega}3}>C(20:3){Delta}{sup 5,11,14}C{sub 18:3}{Delta}{sup 5,9,12}>= C{sub 18:2{omega}6}>C{sub 18:2}{Delta}{sup 5,9}>C{sub 18:1{omega}9}>C{sub 18:1ome= ga7}. 49 refs., 2 figs., 2 tabs.

High-energy ion implantation of materials

International Nuclear Information System (INIS)

Williams, J.M.

1991-11-01

High-energy ion implantation is an extremely flexible type of surface treatment technique, in that it offers the possibility of treating almost any type of target material or product with ions of almost any chemical species, or combinations of chemical species. In addition, ion implantations can be combined with variations in temperature during or after ion implantation. As a result, the possibility of approaching a wide variety of surface-related materials science problems exists with ion implantation. This paper will outline factors pertinent to application of high-energy ion implantation to surface engineering problems. This factors include fundamental advantages and limitations, economic considerations, present and future equipment, and aspects of materials science

Analytical methods for determination of free metal ion concentration, labile species fraction and metal complexation capacity of environmental waters: a review.

Science.gov (United States)

Pesavento, Maria; Alberti, Giancarla; Biesuz, Raffaela

2009-01-12

Different experimental approaches have been suggested in the last few decades to determine metal species in complex matrices of unknown composition as environmental waters. The methods are mainly focused on the determination of single species or groups of species. The more recent developments in trace elements speciation are reviewed focusing on methods for labile and free metal determination. Electrochemical procedures with low detection limit as anodic stripping voltammetry (ASV) and the competing ligand exchange with adsorption cathodic stripping voltammetry (CLE-AdCSV) have been widely employed in metal distribution studies in natural waters. Other electrochemical methods such as stripping chronopotentiometry and AGNES seem to be promising to evaluate the free metal concentration at the low levels of environmental samples. Separation techniques based on ion exchange (IE) and complexing resins (CR), and micro separation methods as the Donnan membrane technique (DMT), diffusive gradients in thin-film gels (DGT) and the permeation liquid membrane (PLM), are among the non-electrochemical methods largely used in this field and reviewed in the text. Under appropriate conditions such techniques make possible the evaluation of free metal ion concentration.

Modulation of biodiversity-invasion relationships by resource availability : commensal species defend invaders in a changing world

NARCIS (Netherlands)

Yang, T.

2017-01-01

Biological invasion brings disturbance to localenvironment, such as reducing available niches or altering species interactions. In order to reduce the undesired consequences brought by invasion, the determining factors suppressing invasion become important. The success of invasion depends on

Emission of positive oxygen ions from ion bombardment of adsorbate-covered metal surfaces

International Nuclear Information System (INIS)

Kaurin, M.G.

1989-01-01

During ion bombardment of metal surfaces, collision cascades can result in the emission of sputtered secondary ions. Recent experiments, however, have suggested that the emission of positive ions of electronegative adsorbates can result from electronic processes rather than from processes involving elastic collisions. This dissertation presents the results of experiments studying the emission of positive oxygen ions from oxygen- and carbon-monoxide-covered transition metal surfaces during bombardment by 25-250 keV ions of neon, argon, and krypton. The systems studied may be grouped into four categories. For a nickel substrate with adsorbed oxygen, the emission of positive oxygen ions proceeds through collision cascades. For titanium and niobium with adsorbed oxygen, the emission of positive oxygen ions is proportional to the primary ion velocity, consistent with emission from electronic processes; for a given primary ion velocity, the oxygen ion yield is independent of primary ion species. For substrates of molybdenum and tungsten, the oxygen yield is proportional to primary ion velocity, but the yield also depends on the primary ion species for a given primary ion velocity in a manner that is consistent with emission resulting from electronic processes. For these two groups, except for titanium, the yields during neon ion bombardment do not extrapolate (assuming linearity with primary ion velocity) to a nonzero value at zero beam velocity. The magnitude of the oxygen ion yields from these targets is not consistent with that expected if the emission were induced by secondary electrons emitted during the ion bombardment

[Application of simultaneous determination of inorganic ionic species by advanced ion chromatography for water quality monitoring of river water and wastewater].

Science.gov (United States)

Nakatani, Nobutake; Kozaki, Daisuke; Tanaka, Kazuhiko

2012-04-01

In this study, our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions (SO4(2-), Cl(-) and NO3(-)) and cations (Na+, NH4+, K+, Mg2+, and Ca2+), nutrients (phosphate and silicate) and hydrogen ion/alkalinity are summarized first. Then, the applications using these methods for monitoring environmental water quality are also presented. For the determination of common anions and cations with nutrients, the separation was successfully performed by a polymethacrylate-based weakly acidic cation-exchange column of TSKgel Super IC-A/C (Tosoh, 150 mm x 6.0 mm i. d.) and a mixture solution of 100 mmol/L ascorbic acid and 4 mmol/L 18-crown-6 as acidic eluent with dual detection of conductivity and spectrophotometry. For the determination of hydrogen ion/alkalinity, the separation was conducted by TSKgel ODS-100Z column (Tosoh, 150 mm x 4.5 mm i. d.) modified with lithium dodecylsulfate and an eluent of 40 mmol/L LiCl/0.1 mmol/L lithium dodecylsulfate/0.05 mmol/L H2SO4 with conductivity detector. The differences of ion concentration between untreated and treated wastewater showed the variation of ionic species during biological treatment process in a sewage treatment plant. Occurrence and distribution of water-quality conditions were related to the bioavailability and human activity in watershed. From these results, our advanced ion chromatographic methods have contributed significantly for water quality monitoring of environmental waters.

Ion sources for initial use at the Holifield radioactive ion beam facility

International Nuclear Information System (INIS)

Alton, G.D.

1994-01-01

The Holifield Radioactive Ion Beam Facility (HRIBF) now under construction at the Oak Ridge National Laboratory will use the 25-MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility; the choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. A high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the HRIBF because of its low emittance, relatively high ionization efficiencies and species versatility, and because it has been engineered for remote installation, removal and servicing as required for safe handling in a high-radiation-level ISOL facility. Prototype plasma-sputter negative ion sources and negative surfaceionization sources are also under design consideration for generating negative radioactive ion beams from high electron-affinity elements. A brief review of the HRIBF will be presented, followed by a detailed description of the design features, operational characteristics, ionization efficiencies, and beam qualities (emittances) of these sources

Equilibrium of field reversed configurations with rotation. IV. Two space dimensions and many ion species

International Nuclear Information System (INIS)

Qerushi, Artan; Rostoker, Norman

2003-01-01

In a previous paper [N. Rostoker and A. Qerushi, Phys. Plasmas 9, 3057 (2002)] a generalized Grad-Shafranov equation for the plasma flux function was derived which provides a complete description of equilibria of field reversed configurations with rotation. In this paper this fundamental equation is solved for two space dimensions and many ion species. The following fusion fuels are considered: D-T, D-He 3 , and p-B 11 . Using periodic boundary conditions the original differential equation is converted to an equivalent integral equation which involves a Green's function. The integral equation is solved by iteration. Approximate solutions are found for all the fusion fuels considered using a two-dimensional equilibrium model for one type of ion [A. Qerushi and N. Rostoker, Phys. Plasmas 9, 5001 (2002)]. They are used as starting trial functions of the iterations. They turn out to be so close to the real solutions that only a few iterations are needed

Experiments on secondary ion emission with multicharged keV ion bombardement

International Nuclear Information System (INIS)

Della Negra, S.; Depauw, J.; Joret, H.; Le Beyec, Y.; Schweikert, E.A.

1987-01-01

An electron cyclotron resonance ion source was used to study the influence of the incident charge state of keV ions on secondary ion emission. The experiments were run with 18 keV Arn+ (1 < n < 11) beams produced by a minimafios source. Various types of targets were bombarded by the ion beam and the sputtered ionized species were identified by time of flight mass spectrometry. The experimental arrangement is detailed and preliminary results are indicated

Species separation and kinetic effects in collisional plasma shocks

Energy Technology Data Exchange (ETDEWEB)

Bellei, C., E-mail: bellei1@llnl.gov; Wilks, S. C.; Amendt, P. A. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Rinderknecht, H.; Zylstra, A.; Rosenberg, M.; Sio, H.; Li, C. K.; Petrasso, R. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-05-15

The properties of collisional shock waves propagating in uniform plasmas are studied with ion-kinetic calculations, in both slab and spherical geometry and for the case of one and two ion species. Despite the presence of an electric field at the shock front—and in contrast to the case where an interface is initially present [C. Bellei et al., Phys. Plasmas 20, 044702 (2013)]—essentially no ion reflection at the shock front is observed due to collisions, with a probability of reflection ≲10{sup −4} for the cases presented. A kinetic two-ion-species spherical convergent shock is studied in detail and compared against an average-species calculation, confirming effects of species separation and differential heating of the ion species at the shock front. The effect of different ion temperatures on the DT and D{sup 3}He fusion reactivity is discussed in the fluid limit and is estimated to be moderately important.

Method of eliminating undesirable gaseous products resulting in underground uranium ore leaching

International Nuclear Information System (INIS)

Krizek, J.; Dedic, K.; Johann, J.; Haas, F.; Sokola, K.

1980-01-01

The method described is characteristic of the fact that gases being formed or dissolved are oxidized using a combined oxidation-reduction system consisting of airborne oxygen, oxygen carriers and a strong irreversible oxidant. The oxygen carrier system consists of a mixture of Fe 2+ and Fe 3+ cations or of Cu + and Cu 2+ cations introduced in solutions in form of iron salts at a concentration of 0.0001 to 0.003 M, or copper salts maximally of 0.0003 M. The irreversible oxidant shows a standard redox potential of at least +1.0 V. In addition to undesirable product elimination, the method allows increasing the leaching process yield. (J.B.)

Novel metal ion surface modification technique

International Nuclear Information System (INIS)

Brown, I.G.; Godechot, X.; Yu, K.M.

1990-10-01

We describe a method for applying metal ions to the near-surface region of solid materials. The added species can be energetically implanted below the surface or built up as a surface film with an atomically mixed interface with the substrate; the metal ion species can be the same as the substrate species or different from it, and more than one kind of metal species can be applied, either simultaneously or sequentially. Surface structures can be fabricated, including coatings and thin films of single metals, tailored alloys, or metallic multilayers, and they can be implanted or added onto the surface and ion beam mixed. We report two simple demonstrations of the method: implantation of yttrium into a silicon substrate at a mean energy of 70 keV and a dose of 1 x 10 16 atoms/cm 2 , and the formation of a titanium-yttrium multilayer structure with ion beam mixing to the substrate. 17 refs., 3 figs

Concepts for the magnetic design of the MITICA neutral beam test facility ion accelerator.

Science.gov (United States)

Chitarin, G; Agostinetti, P; Marconato, N; Marcuzzi, D; Sartori, E; Serianni, G; Sonato, P

2012-02-01

The megavolt ITER injector concept advancement neutral injector test facility will be constituted by a RF-driven negative ion source and by an electrostatic Accelerator, designed to produce a negative Ion with a specific energy up to 1 MeV. The beam is then neutralized in order to obtain a focused 17 MW neutral beam. The magnetic configuration inside the accelerator is of crucial importance for the achievement of a good beam efficiency, with the early deflection of the co-extracted and stripped electrons, and also of the required beam optic quality, with the correction of undesired ion beamlet deflections. Several alternative magnetic design concepts have been considered, comparing in detail the magnetic and beam optics simulation results, evidencing the advantages and drawbacks of each solution both from the physics and engineering point of view.

Ion sources in AMS

International Nuclear Information System (INIS)

Iyer, Indira S.

1997-01-01

Accelerator Mass Spectrometry (AMS) entails the sputtering of various samples in an ion source followed by high precision mass analysis of the sputtered ion species in a Tandem Electrostatic Accelerator. A brief account is given

Are undesirable contact kinematics minimized after kinematically aligned total knee arthroplasty? An intersurgeon analysis of consecutive patients.

Science.gov (United States)

Howell, Stephen M; Hodapp, Esther E; Vernace, Joseph V; Hull, Maury L; Meade, Thomas D

2013-10-01

Tibiofemoral contact kinematics or knee implant motions have a direct influence on patient function and implant longevity and should be evaluated for any new alignment technique such as kinematically aligned total knee arthroplasty (TKA). Edge loading of the tibial liner and external rotation (reverse of normal) and adduction of the tibial component on the femoral component are undesirable contact kinematics that should be minimized. Accordingly, this study determined whether the overall prevalence of undesirable contact kinematics during standing, mid kneeling near 90 degrees and full kneeling with kinematically aligned TKA are minimal and not different between groups of consecutive patients treated by different surgeons. Three surgeons were asked to perform cemented, kinematically aligned TKA with patient-specific guides in a consecutive series of patients with their preferred cruciate-retaining (CR) implant. In vivo tibiofemoral contact positions were obtained using a 3- to 2-dimensional image registration technique in 69 subjects (Vanguard CR-TKA N = 22, and Triathlon CR-TKA N = 47). Anterior or posterior edge loading of the tibial liner was not observed. The overall prevalence of external rotation of the tibial component on the femoral component of 6 % was low and not different between surgeons (n.s.). The overall prevalence of adduction of the tibial component on the femoral component of 4 % was low and not different between surgeons (n.s.). Kinematically aligned TKA minimized the undesirable contact kinematics of edge loading of the tibial liner, and external rotation and adduction of the tibial component on the femoral component during standing and kneeling, which suggests an optimistic prognosis for durable long-term function. III.

Surface charge compensation for a highly charged ion emission microscope

International Nuclear Information System (INIS)

McDonald, J.W.; Hamza, A.V.; Newman, M.W.; Holder, J.P.; Schneider, D.H.G.; Schenkel, T.

2003-01-01

A surface charge compensation electron flood gun has been added to the Lawrence Livermore National Laboratory (LLNL) highly charged ion (HCI) emission microscope. HCI surface interaction results in a significant charge residue being left on the surface of insulators and semiconductors. This residual charge causes undesirable aberrations in the microscope images and a reduction of the Time-Of-Flight (TOF) mass resolution when studying the surfaces of insulators and semiconductors. The benefits and problems associated with HCI microscopy and recent results of the electron flood gun enhanced HCI microscope are discussed

Anomalous microstructural changes in III-nitrides under ion bombardment

International Nuclear Information System (INIS)

Kucheyev, S.O.; Williams, J.S.; Jagadish, C.

2002-01-01

Full text: Group-III nitrides (GaN, AlGaN, and InGaN) are currently a 'hot topic' in the physics and material research community due to very important technological applications of these materials in (opto)electronics. In the fabrication of III-nitride-based devices, ion bombardment represents a very attractive processing tool. However, ion-beam-produced lattice disorder and its undesirable consequences limit technological applications of ion implantation. Hence, studies of ion-beam-damage processes in Ill-nitrides are not only physically interesting but also technologically important. In this study, wurtzite GaN, AlGaN, and InGaN films exposed to ion bombardment under a wide range of irradiation conditions are studied by a combination of transmission electron microscopy (TEM), environmental scanning electron microscopy (ESEM), energy dispersive x-ray spectrometry (EDS), atomic force microscopy (AFM), cathodoluminescence (CL), and Rutherford backscattering/channeling (RBS/C) spectrometry. Results show that, unlike the situation for mature semiconductors such as Si and GaAs, Ill-nitrides exhibit a range of intriguing behavior involving extreme microstructural changes under ion bombardment. In this presentation, the following aspects are discussed: (i) formation of lattice defects during ion bombardment, (ii) ion-beam-induced phase transformations, (iii) ion-beam-produced stoichiometric imbalance and associated material decomposition, and (iv) an application of charging phenomena during ESEM imaging for studies of electrical isolation in GaN by MeV light ion irradiation. Emphasis is given to the (powerful) application of electron microscopy techniques for the understanding of physical processes occurring in Ill-nitrides under ion bombardment. Copyright (2002) Australian Society for Electron Microscopy Inc

Allylic ionic liquid electrolyte-assisted electrochemical surface passivation of LiCoO2 for advanced, safe lithium-ion batteries

Science.gov (United States)

Mun, Junyoung; Yim, Taeeun; Park, Jang Hoon; Ryu, Ji Heon; Lee, Sang Young; Kim, Young Gyu; Oh, Seung M.

2014-01-01

Room-temperature ionic liquid (RTIL) electrolytes have attracted much attention for use in advanced, safe lithium-ion batteries (LIB) owing to their nonvolatility, high conductivity, and great thermal stability. However, LIBs containing RTIL-electrolytes exhibit poor cyclability because electrochemical side reactions cause problematic surface failures of the cathode. Here, we demonstrate that a thin, homogeneous surface film, which is electrochemically generated on LiCoO2 from an RTIL-electrolyte containing an unsaturated substituent on the cation (1-allyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide, AMPip-TFSI), can avert undesired side reactions. The derived surface film comprised of a high amount of organic species from the RTIL cations homogenously covered LiCoO2 with a <25 nm layer and helped suppress unfavorable thermal reactions as well as electrochemical side reactions. The superior performance of the cell containing the AMPip-TFSI electrolyte was further elucidated by surface, electrochemical, and thermal analyses. PMID:25168309

pH and ion strength modulated ionic species loading in mesoporous silica nanoparticles

International Nuclear Information System (INIS)

Liu, Wei; Liu, Jianbo; Yang, Xiaohai; Wang, Kemin; Wang, Qing; Yang, Meng; Li, Li; Xu, Jianguo

2013-01-01

Mesoporous silica nanoparticles (MSN) have emerged as appealing host materials to accommodate guest molecules for biomedical applications, and recently various methods have been developed to modulate the loading of guest molecules in the silica matrix. Herein, it was demonstrated that pH and ion strength showed great influence on the loading of charged species into the nanoparticles, taking MCM-41 as a host MSN model and methylviologen (MV 2+ ) and 1,5-naphthalene disulfonate (NDS 2− ) as typical charged ionic guest molecules. As the pH increased from 3.0 to 8.0, the loading amount of MV 2+ increased gradually, while on the contrary, it decreased gradually for NDS 2− , for the solution pH changed the electrostatic interaction between the silica matrix and the ionic guest molecules. Additionally, the adding of NaCl reduced the electrostatic interaction, which resulted in a decreasing of the electrostatic rejection and electrostatic accumulation for the molecules carrying the same and the opposite charge to the particle respectively. Thus, pH and ion strength can be employed as simple approaches to modulate the loading of charged molecules and permselectivity in MSN. This work has a definite guidance function for molecule loading, transport modulation, controlled release as well as sensors based on MSN. (paper)

On the undesired frequency chirping in photonic time-stretch systems

Science.gov (United States)

Xu, Yuxiao; Chi, Hao; Jin, Tao; Zheng, Shilie; Jin, Xiaofeng; Zhang, Xianmin

2017-12-01

The technique of photonic time stretch (PTS) has been intensively investigated in the past decade due to its potential in the acquisition of ultra-high speed signals. The frequency-related RF power fading in the PTS systems with double sideband (DSB) modulation has been well-known, which limits the maximum modulation frequency. Some solutions have been proposed to solve this problem. In this paper, we report another effect, i.e., undesired frequency chirping, which also relates to the performance degradation of PTS systems with DSB modulation, for the first time to our knowledge. Distinct from the nonlinearities caused by nonlinear modulation and square-law photodetection, which is common in radio frequency analog optical links, this frequency chirping originates from the addition of two beating signals with a relative delay after photodetection. A theoretical model for exactly describing the frequency chirping is presented, and is then verified by simulations. Discussion on the method to avoid the frequency chirping is also presented.

Novel imaging and quality assurance techniques for ion beam therapy a Monte Carlo study

CERN Document Server

Rinaldi, I; Jäkel, O; Mairani, A; Parodi, K

2010-01-01

Ion beams exhibit a finite and well defined range in matter together with an “inverted” depth-dose profile, the so-called Bragg peak. These favourable physical properties may enable superior tumour-dose conformality for high precision radiation therapy. On the other hand, they introduce the issue of sensitivity to range uncertainties in ion beam therapy. Although these uncertainties are typically taken into account when planning the treatment, correct delivery of the intended ion beam range has to be assured to prevent undesired underdosage of the tumour or overdosage of critical structures outside the target volume. Therefore, it is necessary to define dedicated Quality Assurance procedures to enable in-vivo range verification before or during therapeutic irradiation. For these purposes, Monte Carlo transport codes are very useful tools to support the development of novel imaging modalities for ion beam therapy. In the present work, we present calculations performed with the FLUKA Monte Carlo code and pr...

1H and 23Na MAS NMR spectroscopy of cationic species in CO2 selective alkaline earth metal porous silicoaluminophosphates prepared via liquid and solid state ion exchange

International Nuclear Information System (INIS)

Arévalo-Hidalgo, Ana G.; Dugar, Sneha; Fu, Riqiang; Hernández-Maldonado, Arturo J.

2012-01-01

The location of extraframework cations in Sr 2+ and Ba 2+ ion-exchanged SAPO-34 was estimated by means of 1 H and 23 Na MAS NMR spectroscopy and spectral deconvolution. Incorporation of the alkaline earth metal cations onto the SAPO framework was achieved via liquid state ion exchange, coupled partial detemplation/solid-state ion exchange, and combination of both techniques. MAS NMR revealed that the level of ion exchange was limited by the presence of protons and sodium cations near hexagonal prisms (site SI), which are relatively difficult to exchange with the alkaline earth metal due to steric and charge repulsion criteria. In addition, the presence of ammonium cations in the supercages facilitated the exchange of otherwise tenacious hydrogen as corroborated by unit cell compositional data as well as enhanced CO 2 adsorption at low partial pressures. The extraframework ammonium species were produced from partial detemplation of the structure-directing agent employed for the SAPO-34 synthesis, tetraethylammonium. - Graphical abstract: MAS NMR was used to elucidate the position the cationic species in alkaline earth metal exchanged silicoaluminophosphates. These species played a significant role during the ion exchange process and, therefore, the materials ultimate CO 2 adsorption performance. Highlights: ► Location of extraframework Sr 2+ or Ba 2+ cations was estimated by means of 1 H and 23 Na MAS NMR. ► Level of Sr 2+ or Ba 2+ ion exchange was limited by the presence of protons and sodium cations. ► Presence of ammonium cations in the supercages facilitated the exchange. ► Sr 2+ and Ba 2+ ion exchanged SAPOs are outstanding CO 2 adsorbents.

Negative symbolic aspects in destination branding: exploring the role of the 'undesired self' on web-based vacation information search intentions among potential first-time visitors

OpenAIRE

Bosnjak, Michael

2010-01-01

Tourist destination choices depend, among other factors, on the match between the destination’s personality image and consumers’ self-concept, in line with self-image congruence theory. Motives also mediate this relationship, yet tourism research largely neglects the influence of avoidance motives. This study applies the product-based construct of undesired congruity, or consumers’ tendency to avoid undesired stereotypical images, to the context of web-based vacation destination information s...

Cycles of undesirable substances in the food chain; Kreislaeufe unerwuenschter Stoffe in der Lebensmittelkette

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

The working group ''Carry over of undesirable substances in animal feed'' at the Federal Ministry of Food, Agriculture and Forestry (BMELV) in cooperation with the Institute of Animal Nutrition of the Friedrich-Loeffler-Institute (FLI) performed on 27 and 28 October 2011 in Braunschweig a workshop on ''cycles of undesirable substances in Food Chain ''. The aim of the workshop was to present the latest findings of research and Carry over Recommendations of the Carry over - Working Group on undesirable substances in feed and production processes of the feed industry, to evaluate and discuss about this with representatives from science, business and management and to work out the further research and action need. The focus of the considerations were the pathways, the carry over and the Exposure to dioxins and other halogenated hydrocarbons, the effects of Mycotoxins in feed and starting points for preventive measures, the soil contamination and the exposure of humans and animals by cadmium and case studies on Nitrite in feed, antibiotics in plants and residues of pesticides and radionuclides in feed. Furthermore the risks associated with specified manufacturing processes of feed are considered, especially the used materials that come into contact with animal feed, and the risks from nanotechnology. [German] Die Arbeitsgruppe ''Carry over unerwuenschter Stoffe in Futtermitteln'' beim Bundesministerium fuer Ernaehrung, Landwirtschaft und Forsten (BMELV) hat in Zusammenarbeit mit dem Institut fuer Tierernaehrung des Friedrich-Loeffler-Instituts (FLI) am 27. und 28. Oktober 2011 in Braunschweig einen Workshop zum Thema ''Kreislaeufe unerwuenschter Stoffe in der Lebensmittelkette'' durchgefuehrt. Ziel des Workshops war es, die aktuellen Erkenntnisse der Carry over Forschung und die Empfehlungen der Carry over - Arbeitsgruppe zu unerwuenschten Stoffen in Futtermitteln und Produktionsverfahren in

Performance Limitations in High-Energy Ion Colliders

CERN Document Server

Fischer, Wolfram

2005-01-01

High-energy ion colliders (hadron colliders operating with species other than protons) are premier research tools for nuclear physics. The collision energy and high luminosity are important design and operations considerations. However, the experiments also expect flexibility with frequent changes in the collision energy, lattice configuration, and ion species, including asymmetric collisions. For the creation, acceleration, and storage of bright intense ion beams, attention must be paid to space charge, charge exchange, and intra-beam scattering effects. The latter leads to luminosity lifetimes of only a few hours for heavy ions. Ultimately cooling at full energy is needed to overcome this effect. Currently, the Relativistic Heavy Ion Collider at BNL is the only operating high-energy ion collider. The Large Hadron Collider, under construction at CERN, will also run with heavy ions.

Ultrathin and Ion-Selective Janus Membranes for High-Performance Osmotic Energy Conversion.

Science.gov (United States)

Zhang, Zhen; Sui, Xin; Li, Pei; Xie, Ganhua; Kong, Xiang-Yu; Xiao, Kai; Gao, Longcheng; Wen, Liping; Jiang, Lei

2017-07-05

The osmotic energy existing in fluids is recognized as a promising "blue" energy source that can help solve the global issues of energy shortage and environmental pollution. Recently, nanofluidic channels have shown great potential for capturing this worldwide energy because of their novel transport properties contributed by nanoconfinement. However, with respect to membrane-scale porous systems, high resistance and undesirable ion selectivity remain bottlenecks, impeding their applications. The development of thinner, low-resistance membranes, meanwhile promoting their ion selectivity, is a necessity. Here, we engineered ultrathin and ion-selective Janus membranes prepared via the phase separation of two block copolymers, which enable osmotic energy conversion with power densities of approximately 2.04 W/m 2 by mixing natural seawater and river water. Both experiments and continuum simulation help us to understand the mechanism for how membrane thickness and channel structure dominate the ion transport process and overall device performance, which can serve as a general guiding principle for the future design of nanochannel membranes for high-energy concentration cells.

The Emperor’s New Clothing: National Responses to “Undesirable and Unreturnable” Aliens under Asylum and Immigration Law

NARCIS (Netherlands)

Cantor, David James; van Wijk, J.; Singer, Sarah; Bolhuis, M.P.

2017-01-01

The “scandal” of foreign criminals whom our governments cannot send back to their own countries has become something of a tabloid obsession. Yet, while suspected or convicted of serious crimes or considered to pose a danger to society, such “undesirable and unreturnable” aliens equally often

Effect of negative ions on the formation of weak ion acoustic double layers

International Nuclear Information System (INIS)

Kalita, M.K.; Bujarbarua, S.

1985-01-01

Using kinetic theory, small amplitude double layers associated with ion acoustic waves in a plasma containing negative species of ions were investigated. Analytic solution for the double layer potential was carried out. The limiting values of the negative ion density for the existence of this type of DL were calculated and the application of this result to space plasmas is discussed. (author)

Drift wave in pair-ion plasma

Indian Academy of Sciences (India)

ion plasma are discussed. It is shown that the temperature and/or mass difference of both species could produce drift wave in a pair-ion plasma. The results are discussed in the context of the fullerene pair-ion plasma experiment.

Enhanced electron/fuel-ion equilibration through impurity ions: Studies applicable to NIF and Omega

Science.gov (United States)

Petrasso, R. D.; Sio, H.; Kabadi, N.; Lahmann, B.; Simpson, R.; Parker, C.; Frenje, J.; Gatu Johnson, M.; Li, C. K.; Seguin, F. H.; Rinderknecht, H.; Casey, D.; Grabowski, P.; Graziani, F.; Taitano, W.; Le, A.; Chacon, L.; Hoffman, N.; Kagan, G.; Simakov, A.; Zylstra, A.; Rosenberg, M.; Betti, R.; Srinivasan, B.; Mancini, R.

2017-10-01

In shock-driven exploding-pushers, a platform used extensively to study multi-species and kinetic effects, electrons and fuel ions are far out of equilibrium, as reflected by very different temperatures. However, impurity ions, even in small quantities, can couple effectively to the electrons, because of a Z2 dependence, and in turn, impurity ions can then strongly couple to the fuel ions. Through this mechanism, electrons and fuel-ions can equilibrate much faster than they otherwise would. This is a quantitative issue, depending upon the amount and Z of the impurity. For NIF and Omega, we consider the role of this process. Coupled non-linear equations, reflecting the temperatures of the three species, are solved for a range of conditions. Consideration is also given to ablatively driven implosions, since impurities can similarly affect the equilibration. This work was supported in part by DOE/NNSA DE-NA0002949 and DE-NA0002726.

Diagnostics for studies of novel laser ion acceleration mechanisms

OpenAIRE

Senje, Lovisa; Yeung, Mark; Aurand, Bastian; Kuschel, Stephan; Rödel, Christian; Wagner, Florian; Li, Kun; Dromey, Brendan; Bagnoud, Vincent; Neumayer, Paul; Roth, Markus; Wahlström, Claes-Göran; Zepf, Matthew; Kuehl, Thomas; Jung, Daniel

2014-01-01

Diagnostic for investigating and distinguishing different laser ion acceleration mechanisms has been developed and successfully tested. An ion separation wide angle spectrometer can simultaneously investigate three important aspects of the laser plasma interaction: (1) acquire angularly resolved energy spectra for two ion species, (2) obtain ion energy spectra for multiple species, separated according to their charge to mass ratio, along selected axes, and (3) collect laser radiation reflecte...

Multi stage electrodialysis for separation of two metal ion species

Energy Technology Data Exchange (ETDEWEB)

Takahashi, K.; Sakurai, H.; Nii, S.; Sugiura, K. [Nagoya Univ., Nagoya (Japan)

1995-04-20

In this article, separation of two metal ions by electrodialysis with a cation exchange membrane has been investigated. In other words, separation of potassium ion and sodium ion has been investigated by using batch dialysis with and without an electric field and continuous electrodialysis with a four-stage dialyzer. As a result, the difference in the permselectivity between the dialysis with and without an electric field has not been appreciable for the system of potassium and sodium ions with the cation exchange membrane. Concerning the continuous electrodialysis, the concentration ratio between potassium and sodium ions in the outlet solution from the recovery side of the dialyzer has increased with the reflux flow rate and the number of stages. In case when the reflux flow rate has been zero, the concentration ratio with the four-stage dialyzer has become 1.5 which is almost the same as with that with a two-stage dialyzer consisting of a simple membrane. When the reflux flow ratio has been 0.7, the concentration ratio has reached 3.6. 20 refs., 8 figs.

Specific ion effects on membrane potential and the permselectivity of ion exchange membranes.

Science.gov (United States)

Geise, Geoffrey M; Cassady, Harrison J; Paul, Donald R; Logan, Bruce E; Hickner, Michael A

2014-10-21

Membrane potential and permselectivity are critical parameters for a variety of electrochemically-driven separation and energy technologies. An electric potential is developed when a membrane separates electrolyte solutions of different concentrations, and a permselective membrane allows specific species to be transported while restricting the passage of other species. Ion exchange membranes are commonly used in applications that require advanced ionic electrolytes and span technologies such as alkaline batteries to ammonium bicarbonate reverse electrodialysis, but membranes are often only characterized in sodium chloride solutions. Our goal in this work was to better understand membrane behaviour in aqueous ammonium bicarbonate, which is of interest for closed-loop energy generation processes. Here we characterized the permselectivity of four commercial ion exchange membranes in aqueous solutions of sodium chloride, ammonium chloride, sodium bicarbonate, and ammonium bicarbonate. This stepwise approach, using four different ions in aqueous solution, was used to better understand how these specific ions affect ion transport in ion exchange membranes. Characterization of cation and anion exchange membrane permselectivity, using these ions, is discussed from the perspective of the difference in the physical chemistry of the hydrated ions, along with an accompanying re-derivation and examination of the basic equations that describe membrane potential. In general, permselectivity was highest in sodium chloride and lowest in ammonium bicarbonate solutions, and the nature of both the counter- and co-ions appeared to influence measured permselectivity. The counter-ion type influences the binding affinity between counter-ions and polymer fixed charge groups, and higher binding affinity between fixed charge sites and counter-ions within the membrane decreases the effective membrane charge density. As a result permselectivity decreases. The charge density and polarizability

"Should I or shouldn't I?" Imitation of undesired versus allowed actions from peer and adult models by 18- and 24-month-old toddlers.

Science.gov (United States)

Seehagen, Sabine; Schneider, Silvia; Miebach, Kristin; Frigge, Katharina; Zmyj, Norbert

2017-11-01

Imitation is a common way of acquiring novel behaviors in toddlers. However, little is known about toddlers' imitation of undesired actions. Here we investigated 18- and 24-month-olds' (N=110) imitation of undesired and allowed actions from televised peer and adult models. Permissiveness of the demonstrated actions was indicated by the experimenter's response to their execution (angry or neutral). Analyses revealed that toddlers' imitation scores were higher after demonstrations of allowed versus undesired actions, regardless of the age of the model. In agreement with prior research, these results suggest that third-party reactions to a model's actions can be a powerful cue for toddlers to engage in or refrain from imitation. In the context of the present study, third-party reactions were more influential on imitation than the model's age. Considering the relative influence of different social cues for imitation can help to gain a fuller understanding of early observational learning. Copyright © 2017 Elsevier Inc. All rights reserved.

Method and apparatus for selective filtering of ions

Science.gov (United States)

Page, Jason S [Kennewick, WA; Tang, Keqi [Richland, WA; Smith, Richard D [Richland, WA

2009-04-07

An adjustable, low mass-to-charge (m/z) filter is disclosed employing electrospray ionization to block ions associated with unwanted low m/z species from entering the mass spectrometer and contributing their space charge to down-stream ion accumulation steps. The low-mass filter is made by using an adjustable potential energy barrier from the conductance limiting terminal electrode of an electrodynamic ion funnel, which prohibits species with higher ion mobilities from being transmitted. The filter provides a linear voltage adjustment of low-mass filtering from m/z values from about 50 to about 500. Mass filtering above m/z 500 can also be performed; however, higher m/z species are attenuated. The mass filter was evaluated with a liquid chromatography-mass spectrometry analysis of an albumin tryptic digest and resulted in the ability to block low-mass, "background" ions which account for 40-70% of the total ion current from the ESI source during peak elution.

SERS analysis of Ag nanostructures produced by ion-beam deposition

Science.gov (United States)

Atanasov, P. A.; Nedyalkov, N. N.; Nikov, Ru G.; Grüner, Ch; Rauschenbach, B.; Fukata, N.

2018-03-01

This study deals with the development of a novel technique for formation of advanced Ag nanostructures (NSs) to be applied to high-resolution analyses based on surface enhanced Raman scattering (SERS). It has direct bearing on human health and food quality, e.g., monitoring small amount or traces of pollutants or undesirable additives. Three types of nanostructured Ag samples were produced using ion-beam deposition at glancing angle (GLAD) on quartz. All fabricated structures were covered with BI-58 pesticide (dimethoate) or Rhodamine 6G (R6G) for testing their potential for use as substrates for (SERS).

Invasive non-native species' provision of refugia for endangered native species.

Science.gov (United States)

Chiba, Satoshi

2010-08-01

The influence of non-native species on native ecosystems is not predicted easily when interspecific interactions are complex. Species removal can result in unexpected and undesired changes to other ecosystem components. I examined whether invasive non-native species may both harm and provide refugia for endangered native species. The invasive non-native plant Casuarina stricta has damaged the native flora and caused decline of the snail fauna on the Ogasawara Islands, Japan. On Anijima in 2006 and 2009, I examined endemic land snails in the genus Ogasawarana. I compared the density of live specimens and frequency of predation scars (from black rats [Rattus rattus]) on empty shells in native vegetation and Casuarina forests. The density of land snails was greater in native vegetation than in Casuarina forests in 2006. Nevertheless, radical declines in the density of land snails occurred in native vegetation since 2006 in association with increasing predation by black rats. In contrast, abundance of Ogasawarana did not decline in the Casuarina forest, where shells with predation scars from rats were rare. As a result, the density of snails was greater in the Casuarina forest than in native vegetation. Removal of Casuarina was associated with an increased proportion of shells with predation scars from rats and a decrease in the density of Ogasawarana. The thick and dense litter of Casuarina appears to provide refugia for native land snails by protecting them from predation by rats; thus, eradication of rats should precede eradication of Casuarina. Adaptive strategies, particularly those that consider the removal order of non-native species, are crucial to minimizing the unintended effects of eradication on native species. In addition, my results suggested that in some cases a given non-native species can be used to mitigate the impacts of other non-native species on native species.

Rotation characteristics of main ions and impurity ions in H-mode tokamak plasma

International Nuclear Information System (INIS)

Kim, J.; Burrell, K.H.; Gohil, P.; Groebner, R.J.; Kim, Y.; St. John, H.E.; Seraydarian, R.P.; Wade, M.R.

1994-01-01

Poloidal and toroidal rotation of the main ions (He 2+ ) and the impurity ions (C 6+ and B 5+ ) in H-mode helium plasmas have been measured via charge exchange recombination spectroscopy in the DIII-D tokamak. It was discovered that the main ion poloidal rotation is in the ion diamagnetic drift direction while the impurity ion rotation is in the electron diamagnetic drift direction, in qualitative agreement with the neoclassical theory. The deduced radial electric field in the edge is of the same negative-well shape regardless of which ion species is used, validating the fundamental nature of the electric field in L-H transition phenomenology

Multiple ion species fluid modeling of sprite halos and the role of electron detachment from O- in their dynamics

Science.gov (United States)

Liu, N.

2011-12-01

Sprite halos are brief descending glows appearing at the lower ionosphere boundary, which follow impulsive cloud-to-ground lightning discharges [e.g., Barrington-Leigh et al., JGR, 106, 1741, 2001, Wescott et al., JGR, 106, 10467, 2001; Pasko, JGR, 115, A00E35, 2010]. They last for a few milliseconds, with horizontal extension of tens of kilometers and vertical thickness of several kilometers. According to global survey of the occurrence of transient luminous events by the ISUAL instruments on the FORMOSAT-2 satellite, on average sprite halos occur once every minute on Earth [Chen et al., JGR, 113, A08306, 2008]. It has been established that sprite halos are caused by electron heating, and molecule excitation and ionization in the lower ionosphere due to lightning quasi-electrostatic field [e.g., Pasko et al., JGR, 102, 4529, 1997; Barrington-Leigh et al., 2001; Pasko, 2010]. Past modeling work on sprite halos was conducted using either a two dimensional (2D) model of at most three charged species or a zero dimensional model of multiple ion species. In this talk, we report a modeling study of sprite halos using a recently developed 2D fluid model of multiple charged species. The model charged species include the ion species set used in [Lehtinen and Inan, GRL, 34, L08804, 2007] to study the dynamics of ionization perturbations produced by gigantic jets in the middle and upper atmosphere. In addition, another charged species, O-, is added to this set, because electron detachment of O- can proceed very fast under moderate electric field [Rayment and Moruzzi, Int. J. Mass Spectrom., 26, 321, 1978], requiring a separate treatment from the other light negative ions. The modeling results of a sprite halo driven by positive cloud-to-ground lightning indicate that the halo can descend to lower altitude with much higher electron density behind its front when the O- detachment process is included. Electron density ahead of the halo front is not significantly reduced from the

Novel lanthanide doped micro- and mesoporous solids. Characterization of ion-host-interactions, species distribution and luminescence properties using time-resolved luminescence spectroscopy; Neuartige Lanthanoid-dotierte mikro- und mesoporoese Feststoffe. Charakterisierung von Ion-Wirt-Wechselwirkungen, Speziesverteilung und Lumineszenzeigenschaften mittels zeitaufgeloester Lumineszenzspektroskopie

Energy Technology Data Exchange (ETDEWEB)

Gessner, Andre

2010-12-15

In this work lanthanide-doped microporous zeolites, microporous-mesoporous hybrid materials and mesoporous silicates were investigated regarding their luminescence properties and the ion-host-interactions using time-resolved luminescence spectroscopy. Thereby, time-resolved emission spectra (TRES) provide information in the wavelength and time domain. For the analysis of the TRES a broad set of analytic methods was applied and thus a corresponding ''toolbox'' developed. Fitting of the luminescence decays was performed with a discrete number of exponentials and supported by luminescence decay times distributions. Time-resolved area normalized emission spectra (TRANES), an advancement of TRES, could be used for the determination of the number of emissive lanthanide species in porous materials for the first time. Calculation of the decay-associated spectra (DAS) allowed the correlation of spectral information with luminescence decay times and thus delivered the luminescence spectra of the different europium species. For europium(III) we could use in addition the time-dependent asymmetry ratio and spectral evolution of the {sup 5}D{sub 0}-{sup 7}F{sub 0}-transition with time to obtain further information about the distribution of the lanthanide ions in the host material. Luminescence decay times and spectra allowed conclusions on the number of OH-oscillators in and the symmetry of the first coordination sphere. For the microporous and microporous-mesoporous materials were found different lanthanide species, which were characterized by the above mentioned methods. These lanthanide species can be found on different positions in the host material. One position is located deep in the pore system. Here, lanthanide ions are hardly accessible for water and mainly coordinated by framework oxygens. This results in long luminescence decay times and distorted coordination spheres. The second position can be found near or on the outer surface or in the

Faraday cup for analyzing multi-ion plasma

International Nuclear Information System (INIS)

Fujita, Takao

1987-01-01

A compact and convenient ion analyzer (a kind of a Faraday cup) is developed in order to analyze weakly ionized multi-ion plasmas. This Faraday cup consists of three mesh electrodes and a movable ion collector. With a negative gate pulse superimposed on the ion retarding bias, ions are analyzed by means of time-of-flight. The identification of ion species and measurements of ion density and ion temperature are studied. (author)

Ion sources for industrial use

International Nuclear Information System (INIS)

Sakudo, Noriyuki

1994-01-01

Industrial applications of ion beams began in the 1970's with their application in fabrication of semiconductor devices. Since then, various improvements have been carried out for source lifetimes, current levels and diversification of ion species. Nowadays, ion beams are expected to be used for surface modification of materials as well as semiconductor fabrication. In this report, some of the typical ion sources are reviewed from the viewpoint of future industrial use. (author)

Simulation studies of acceleration of heavy ions and their elemental compositions

International Nuclear Information System (INIS)

Toida, Mieko; Ohsawa, Yukiharu

1996-07-01

By using a one-dimensional, electromagnetic particle simulation code with full ion and electron dynamics, we have studied the acceleration of heavy ions by a nonlinear magnetosonic wave in a multi-ion-species plasma. First, we describe the mechanism of heavy ion acceleration by magnetosonic waves. We then investigate this by particle simulations. The simulation plasma contains four ion species: H, He, O, and Fe. The number density of He is taken to be 10% of that of H, and those of O and Fe are much lower. Simulations confirm that, as in a single-ion-species plasma, some of the hydrogens can be accelerated by the longitudinal electric field formed in the wave. Furthermore, they show that magnetosonic waves can accelerate all the particles of all the heavy species (He, O, and Fe) by a different mechanism, i.e., by the transverse electric field. The maximum speeds of the heavy species are about the same, of the order of the wave propagation speed. These are in good agreement with theoretical prediction. These results indicate that, if high-energy ions are produced in the solar corona through these mechanisms, the elemental compositions of these heavy ions can be similar to that of the background plasma, i.e., the corona

Development of intense high-energy noble gas ion beams from in-terminal ion injector of tandem accelerator using an ECR ion source

Energy Technology Data Exchange (ETDEWEB)

Matsuda, M., E-mail: matsuda.makoto@jaea.go.jp [Japan Atomic Energy Agency (JAEA), Tokai Research and Development Center, 2-4 Shirakata-shirane, Tokai, Naka, Ibaraki 319-1195 (Japan); Nakanoya, T.; Hanashima, S.; Takeuchi, S. [Japan Atomic Energy Agency (JAEA), Tokai Research and Development Center, 2-4 Shirakata-shirane, Tokai, Naka, Ibaraki 319-1195 (Japan)

2011-10-21

An ECRIS-based heavy ion injector was constructed in the high-voltage terminal of JAEA-Tokai Tandem Accelerator to develop new beam species of highly charged noble gas ions. This work was associated with a lot of development to operate the ion source on the 20UR Pelletron high voltage terminal in high pressure SF{sub 6} gas environment. Highly charged ions of N, O, Ne, Ar, Kr and Xe have been accelerated satisfactorily. Operating data integrated during many years long beam delivery service are summarized.

BETWEEN THE RIGHT AND THE COMMON. HOW GROUPS REACT TO SOCIALLY UNDESIRABLE BEHAVIOUR

Directory of Open Access Journals (Sweden)

Komendant-Brodowska Agata

2017-06-01

Full Text Available The aim of the paper is to analyse the relationship between group characteristics and the scope of reaction of the group to socially undesirable behaviour. Sometimes small groups or communities fail to react to undesirable or violent behaviour and their apathy can have devastating consequences. Such a situation can occur among co-workers witnessing workplace mobbing, or neighbours who do not react to a suspicion of domestic violence. Reasons for their inaction are diverse and can include fear, doubts concerning the necessity of such a reaction, and also conformity. In the paper I examine a seemingly favourable situation: I assume that reaction is costless and all the members of the group would like to react (internalised norm, but they also want to conform. In order to analyse the factors that can influence the scope of group reaction, a structurally embedded sequential coordination game was played for different initial conditions. Computer simulations were conducted for networks of a specific type (Erd¨os-R´enyi random graph. The main aim of the analysis was to identify non-structural and structural features of the group that can impede or even block the intervention of the group. There is a positive relationship between the scope of group reaction and the strength of the internalized norm, whereas the level of conformity affects the chances of group intervention in a negative way. Heterogeneity of the group is an important factor - the scope of reaction is higher when members of the group have different levels of norm internalisation and conformity. There is a non-linear relationship between network density and the scope of reaction. Both low and high density can make it harder for people to act.

Spectrometric determination of the species distribution of hydrogen and deuterium in the multi-megawatt ion sources (PINI) of the neutral beam injectors NI-1 and NI-2 of TEXTOR

International Nuclear Information System (INIS)

Rotter, H.; Uhlemann, R.

1990-11-01

The ion species fractions of hydrogen H + , H 2 + , H 3 + and deuterium D + , D 2 + , D 3 + in the extracted beam of the multi-megawatt ion sources (PINI) of the neutral beam injectors of TEXTOR are determined. The measurements are obtained from two grating spectrometers of 0.5 m focal length with a light guiding system of 50 mm aperture using the Doppler shifted H α /D α -light of the accelerated beam particles. The spectral resolution obtained is 0.76 A with a 50 μm entrance slit. The ion source is a bucket source (modified JET PINI) with a multipole magnetic field in checkerboard arrangement. The species fraction measurements are performed as function of beam current, ion source pressure and beam pulse length. The results for hydrogen and deuterium at particle energies of 20-55 keV and beam currents of 13-87 A show no significant difference between neutral injector I and II. For 55 keV and a beam current of 87 A in hydrogen and 63 A in deuterium a species mix of 67.2:24.5:8.4% (H + :H 2 + :H 3 + ) and of 69.1:23.8:7.1% (D + :D 2 + :D 3 + ) is obtained. (orig.) [de

Dissolution of granulated wood ash examined by in situ incubation: Effects of tree species and soil type

DEFF Research Database (Denmark)

Callesen, Ingeborg; Ingerslev, M.; Raulund-Rasmussen, K.

2007-01-01

handling and to avoid undesired effects on vegetation and leaching of nutrients. Forest ecosystems with different tree species and soils provide variable conditions for mineral dissolution with respect to pH, amount of organic ligands and humidity in the forest floor and the top soil. To study the effects...

Selection and design of ion sources for use at the Holifield radioactive ion beam facility

International Nuclear Information System (INIS)

Alton, G.D.; Haynes, D.L.; Mills, G.D.; Olsen, D.K.

1994-01-01

The Holifield Radioactive Ion Beam Facility now under construction at the Oak Ridge National Laboratory will use the 25 MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility. The choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. Although direct-extraction negative ion sources are clearly desirable, the ion formation efficiencies are often too low for practical consideration; for this situation, positive ion sources, in combination with charge exchange, are the logical choice. The high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the facility because of its low emittance, relatively high ionization efficiencies, and species versatility, and because it has been engineered for remote installation, removal, and servicing as required for safe handling in a high-radiation-level ISOL facility. The source will be primarily used to generate ion beams from elements with intermediate to low electron affinities. Prototype plasma-sputter negative ion sources and negative surface-ionization sources are under design consideration for generating radioactive ion beams from high-electron-affinity elements. The design features of these sources and expected efficiencies and beam qualities (emittances) will be described in this report

Ion implantation technology

CERN Document Server

Downey, DF; Jones, KS; Ryding, G

1993-01-01

Ion implantation technology has made a major contribution to the dramatic advances in integrated circuit technology since the early 1970's. The ever-present need for accurate models in ion implanted species will become absolutely vital in the future due to shrinking feature sizes. Successful wide application of ion implantation, as well as exploitation of newly identified opportunities, will require the development of comprehensive implant models. The 141 papers (including 24 invited papers) in this volume address the most recent developments in this field. New structures and possible approach

Specific ion effects on membrane potential and the permselectivity of ion exchange membranes

KAUST Repository

Geise, Geoffrey M.

2014-08-26

© the Partner Organisations 2014. Membrane potential and permselectivity are critical parameters for a variety of electrochemically-driven separation and energy technologies. An electric potential is developed when a membrane separates electrolyte solutions of different concentrations, and a permselective membrane allows specific species to be transported while restricting the passage of other species. Ion exchange membranes are commonly used in applications that require advanced ionic electrolytes and span technologies such as alkaline batteries to ammonium bicarbonate reverse electrodialysis, but membranes are often only characterized in sodium chloride solutions. Our goal in this work was to better understand membrane behaviour in aqueous ammonium bicarbonate, which is of interest for closed-loop energy generation processes. Here we characterized the permselectivity of four commercial ion exchange membranes in aqueous solutions of sodium chloride, ammonium chloride, sodium bicarbonate, and ammonium bicarbonate. This stepwise approach, using four different ions in aqueous solution, was used to better understand how these specific ions affect ion transport in ion exchange membranes. Characterization of cation and anion exchange membrane permselectivity, using these ions, is discussed from the perspective of the difference in the physical chemistry of the hydrated ions, along with an accompanying re-derivation and examination of the basic equations that describe membrane potential. In general, permselectivity was highest in sodium chloride and lowest in ammonium bicarbonate solutions, and the nature of both the counter- and co-ions appeared to influence measured permselectivity. The counter-ion type influences the binding affinity between counter-ions and polymer fixed charge groups, and higher binding affinity between fixed charge sites and counter-ions within the membrane decreases the effective membrane charge density. As a result permselectivity decreases. The

Quantitative profiling of PE, MMPE, DMPE, and PC lipid species by multiple precursor ion scanning: A tool for monitoring PE metabolism

DEFF Research Database (Denmark)

Bilgin, Mesut; Markgraf, Daniel F; Duchoslav, Eva

2011-01-01

We report a method for the simultaneous identification and quantification of phosphatidylethanolamine (PE), monomethyl-phosphatidylethanolamine (MMPE), dimethyl-phosphatidylethanolamine (DMPE), and phosphatidylcholine (PC) species in lipid extracts. The method employs a specific "mass-tag" strategy...... where DMPE, MMPE, and PE species are chemically methylated with deuterated methyliodide (CD(3)I) to produce PC molecules having class-specific mass offsets of 3, 6 and 9Da, respectively. The derivatized aminoglycerophospholipids release characteristic phosphorylcholine-like fragment ions having specific...... and DMPE, and abundant PE and PC species in a single mass spectrometric analysis. We demonstrated the efficacy of the methodology by conducting a series of biochemical experiments using stable isotope labeled ethanolamine to survey the activities and substrate specificities of enzymes involved in PE...

ELECTRON BEAM ION SOURCE PRE-INJECTOR DIGNOSTICS

International Nuclear Information System (INIS)

WILINSKI, M.; ALESSI, J.; BEEBE, E.; BELLAVIA, S.; PIKIN, A.

2006-01-01

A new ion pre-injector line is currently under design at Brookhaven National Laboratory (BNL) for the Relativistic Heavy Ion Collider (RHIC) and the NASA Space Radiation Laboratory (NSRL,). Collectively, this new line is referred to as the EBIS project. This pre-injector is based on an Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (R-FQ) accelerator, and a linear accelerator. The new EBIS will be able to produce a wide range of heavy ion species as well as rapidly switching between species. To aid in operation of the pre-injector line, a suite of diagnostics is currently proposed which includes faraday cups, current transformers, profile monitors, and a pepperpot emittance measurement device

Numerical modelling of ion transport in flames

KAUST Repository

Han, Jie

2015-10-20

This paper presents a modelling framework to compute the diffusivity and mobility of ions in flames. The (n, 6, 4) interaction potential is adopted to model collisions between neutral and charged species. All required parameters in the potential are related to the polarizability of the species pair via semi-empirical formulas, which are derived using the most recently published data or best estimates. The resulting framework permits computation of the transport coefficients of any ion found in a hydrocarbon flame. The accuracy of the proposed method is evaluated by comparing its predictions with experimental data on the mobility of selected ions in single-component neutral gases. Based on this analysis, the value of a model constant available in the literature is modified in order to improve the model\\'s predictions. The newly determined ion transport coefficients are used as part of a previously developed numerical approach to compute the distribution of charged species in a freely propagating premixed lean CH4/O2 flame. Since a significant scatter of polarizability data exists in the literature, the effects of changes in polarizability on ion transport properties and the spatial distribution of ions in flames are explored. Our analysis shows that changes in polarizability propagate with decreasing effect from binary transport coefficients to species number densities. We conclude that the chosen polarizability value has a limited effect on the ion distribution in freely propagating flames. We expect that the modelling framework proposed here will benefit future efforts in modelling the effect of external voltages on flames. Supplemental data for this article can be accessed at http://dx.doi.org/10.1080/13647830.2015.1090018. © 2015 Taylor & Francis.

When can efforts to control nuisance and invasive species backfire?

Science.gov (United States)

Zipkin, Elise F; Kraft, Clifford E; Cooch, Evan G; Sullivan, Patrick J

2009-09-01

Population control through harvest has the potential to reduce the abundance of nuisance and invasive species. However, demographic structure and density-dependent processes can confound removal efforts and lead to undesirable consequences, such as overcompensation (an increase in abundance in response to harvest) and instability (population cycling or chaos). Recent empirical studies have demonstrated the potential for increased mortality (such as that caused by harvest) to lead to overcompensation and instability in plant, insect, and fish populations. We developed a general population model with juvenile and adult stages to help determine the conditions under which control harvest efforts can produce unintended outcomes. Analytical and simulation analyses of the model demonstrated that the potential for overcompensation as a result of harvest was significant for species with high fecundity, even when annual stage-specific survivorship values were fairly low. Population instability as a result of harvest occurred less frequently and was only possible with harvest strategies that targeted adults when both fecundity and adult survivorship were high. We considered these results in conjunction with current literature on nuisance and invasive species to propose general guidelines for assessing the risks associated with control harvest based on life history characteristics of target populations. Our results suggest that species with high per capita fecundity (over discrete breeding periods), short juvenile stages, and fairly constant survivorship rates are most likely to respond undesirably to harvest. It is difficult to determine the extent to which overcompensation and instability could occur during real-world removal efforts, and more empirical removal studies should be undertaken to evaluate population-level responses to control harvests. Nevertheless, our results identify key issues that have been seldom acknowledged and are potentially generic across taxa.

Determination of inorganic ions in natural water by ion chromatography

International Nuclear Information System (INIS)

Nazaratul Ashifa Abdullah Salim; Mohd Suhaimi Hamzah; Eewiat Edin Put; Abdul Khalik Wood; Shamsiah Abdul Rahman; Md Suhaimi Elia

2010-01-01

Ion chromatography (IC) is a well established methodology for analysis of ionic species. The concentration of ionic species was determined using suppressed IC with conductivity detection. Anion species were determined in a single 15-min run with Na 2 CO 3 and NaHCO 3 eluent. Cation species were analysed by direct injection of 1 ml and isocratic elution with a methanesulfonic acid (MSA) eluent. Natural water were collected from various sources such as rainwater, lake, river and groundwater. Analysis performance of IC system was validated by evaluating the linear regression of calibration curve, recovery of spike sample and quality control sample. (author)

Method and apparatus for removing ions from soil

Science.gov (United States)

Bibler, Jane P.

1993-01-01

A method and apparatus for selectively removing species of ions from an area of soil. Permeable membranes 14 and 18 impregnated with an ion exchange resin that is specific to one or more species of chemical ions are inserted into ground 12 in close proximity to, and on opposing sides of, a soil area of interest 22. An electric potential is applied across electrodes 26 and 28 to cause the migration of ions out of soil area 22 toward the membranes 14 and 18. Preferably, the resin exchanges ions of sodium or hydrogen for ions of mercury that it captures from soil area 22. Once membranes 14 and 18 become substantially saturated with mercury ions, the potential applied across electrodes 26 and 28 is discontinued and membranes 14 and 18 are preferably removed from soil 12 for storage or recovery of the ions. The membranes are also preferably impregnated with a buffer to inhibit the effect of the hydrolysis of water by current from the electrodes.

Study on surface modification of M2 steel induced by Cu ions and Al ions implantation

International Nuclear Information System (INIS)

Wang Chao; Liu Zhengmin

2001-01-01

Changes of surface hardness and wear resistances in M2 type steel implanted by Cu Al ions were reported. The dependence of surface strengthening on ion species and dose was studied by X-ray diffraction (XRD) and Rutherford Backscattering Spectroscopy (RBS) for microhardness and wear resistances measurement. It is shown that both hardness and wear resistance increases apparently after ion implantation. XRD analysis indicates that different phases formed after Al Cu ions implanted. It is also suggested that Cu, Al ions have different role in surface strengthening

Plasma ion sources and ion beam technology in microfabrications

International Nuclear Information System (INIS)

Ji, Lili

2007-01-01

For over decades, focused ion beam (FIB) has been playing a very important role in microscale technology and research, among which, semiconductor microfabrication is one of its biggest application area. As the dimensions of IC devices are scaled down, it has shown the need for new ion beam tools and new approaches to the fabrication of small-scale devices. In the meanwhile, nanotechnology has also deeply involved in material science research and bioresearch in recent years. The conventional FIB systems which utilize liquid gallium ion sources to achieve nanometer scale resolution can no longer meet the various requirements raised from such a wide application area such as low contamination, high throughput and so on. The drive towards controlling materials properties at nanometer length scales relies on the availability of efficient tools. In this thesis, three novel ion beam tools have been developed and investigated as the alternatives for the conventional FIB systems in some particular applications. An integrated focused ion beam (FIB) and scanning electron microscope (SEM) system has been developed for direct doping or surface modification. This new instrument employs a mini-RF driven plasma source to generate focused ion beam with various ion species, a FEI two-lens electron (2LE) column for SEM imaging, and a five-axis manipulator system for sample positioning. An all-electrostatic two-lens column has been designed to focus the ion beam extracted from the source. Based on the Munro ion optics simulation, beam spot sizes as small as 100 nm can be achieved at beam energies between 5 to 35 keV if a 5 (micro)m-diameter extraction aperture is used. Smaller beam spot sizes can be obtained with smaller apertures at sacrifice of some beam current. The FEI 2LE column, which utilizes Schottky emission, electrostatic focusing optics, and stacked-disk column construction, can provide high-resolution (as small as 20 nm) imaging capability, with fairly long working distance

The physics and technology of ion sources

International Nuclear Information System (INIS)

Brown, I.G.

1989-01-01

New applications call for ion beams of unprecedented energy, current, species, focus, uniformity, size, and charge states. This comprehensive, up-to-date review and reference for the rapidly evolving field of ion source technology relates improvements to traditional ion sources and describes the development of the new kinds of ion sources. Also provides background material on the physics of ion sources. Chapters are self-contained, making for easy reference

Ion-induced particle desorption in time-of-flight medium energy ion scattering

Science.gov (United States)

Lohmann, S.; Primetzhofer, D.

2018-05-01

Secondary ions emitted from solids upon ion impact are studied in a time-of-flight medium energy ion scattering (ToF-MEIS) set-up. In order to investigate characteristics of the emission processes and to evaluate the potential for surface and thin film analysis, experiments employing TiN and Al samples were conducted. The ejected ions exhibit a low initial kinetic energy of a few eV, thus, requiring a sufficiently high acceleration voltage for detection. Molecular and atomic ions of different charge states originating both from surface contaminations and the sample material are found, and relative yields of several species were determined. Experimental evidence that points towards a predominantly electronic sputtering process is presented. For emitted Ti target atoms an additional nuclear sputtering component is suggested.

Environmentally Clean Mitigation of Undesirable Plant Life Using Lasers

Energy Technology Data Exchange (ETDEWEB)

Rubenchik, A M; McGrann, T J; Yamamoto, R M; Parker, J M

2009-07-01

This concept comprises a method for environmentally clean destruction of undesirable plant life using visible or infrared radiation. We believe that during the blossom stage, plant life is very sensitive to electromagnetic radiation, with an enhanced sensitivity to specific spectral ranges. Small doses of irradiation can arrest further plant growth, cause flower destruction or promote plant death. Surrounding plants, which are not in the blossoming stage, should not be affected. Our proposed mechanism to initiate this effect is radiation produced by a laser. Tender parts of the blossom possess enhanced absorptivity in some spectral ranges. This absorption can increase the local tissue temperature by several degrees, which is sufficient to induce bio-tissue damage. In some instances, the radiation may actually stimulate plant growth, as an alternative for use in increased crop production. This would be dependent on factors such as plant type, the wavelength of the laser radiation being used and the amount of the radiation dose. Practical, economically viable realization of this concept is possible today with the advent of high efficiency, compact and powerful laser diodes. The laser diodes provide an efficient, environmentally clean source of radiation at a variety of power levels and radiation wavelengths. Figure 1 shows the overall concept, with the laser diodes mounted on a movable platform, traversing and directing the laser radiation over a field of opium poppies.

Targets for ion sources for RIB generation at the Holifield Radioactive Ion Beam Facility

International Nuclear Information System (INIS)

Alton, G.D.

1995-01-01

The Holifield Radioactive Ion Beam Facility (HRIBF), now under construction at the Oak Ridge National Laboratory, is based on the use of the well-known on-line isotope separator (ISOL) technique in which radioactive nuclei are produced by fusion type reactions in selectively chosen target materials by high-energy proton, deuteron, or He ion beams from the Oak Ridge Isochronous Cyclotron (ORIC). Among several major challenges posed by generating and accelerating adequate intensities of radioactive ion beams (RIBs), selection of the most appropriate target material for production of the species of interest is, perhaps, the most difficult. In this report, we briefly review present efforts to select target materials and to design composite target matrix/heat-sink systems that simultaneously incorporate the short diffusion lengths, high permeabilities, and controllable temperatures required to effect maximum diffusion release rates of the short-lived species that can be realized at the temperature limits of specific target materials. We also describe the performance characteristics for a selected number of target ion sources that will be employed for initial use at the HRIBF as well as prototype ion sources that show promise for future use for RIB applications

Self-similar solutions for multi-species plasma mixing by gradient driven transport

Science.gov (United States)

Vold, E.; Kagan, G.; Simakov, A. N.; Molvig, K.; Yin, L.

2018-05-01

Multi-species transport of plasma ions across an initial interface between DT and CH is shown to exhibit self-similar species density profiles under 1D isobaric conditions. Results using transport theory from recent studies and using a Maxwell–Stephan multi-species approximation are found to be in good agreement for the self-similar mix profiles of the four ions under isothermal and isobaric conditions. The individual ion species mass flux and molar flux profile results through the mixing layer are examined using transport theory. The sum over species mass flux is confirmed to be zero as required, and the sum over species molar flux is related to a local velocity divergence needed to maintain pressure equilibrium during the transport process. The light ion species mass fluxes are dominated by the diagonal coefficients of the diffusion transport matrix, while for the heaviest ion species (C in this case), the ion flux with only the diagonal term is reduced by about a factor two from that using the full diffusion matrix, implying the heavy species moves more by frictional collisions with the lighter species than by its own gradient force. Temperature gradient forces were examined by comparing profile results with and without imposing constant temperature gradients chosen to be of realistic magnitude for ICF experimental conditions at a fuel-capsule interface (10 μm scale length or greater). The temperature gradients clearly modify the relative concentrations of the ions, for example near the fuel center, however the mixing across the fuel-capsule interface appears to be minimally influenced by the temperature gradient forces within the expected compression and burn time. Discussion considers the application of the self-similar profiles to specific conditions in ICF.

Sawtooth activity of the ion cloud in an electron-beam ion trap

International Nuclear Information System (INIS)

Radtke, R.; Biedermann, C.

2003-01-01

The dynamics of an ensemble of highly charged Ar and Ba ions in an electron-beam ion trap (EBIT) was studied by recording time-resolved x-ray spectra emitted from trapped ions. Sawtoothlike signatures manifest in the spectra for a variety of EBIT operating conditions indicating a sudden collapse of the ion inventory in the trap. The collapse occurs on a time scale of approximately 100 ms and the evolution of the sawteeth is very sensitive to parameters such as electron-beam current and axial trap depth. Analysis of the measurements is based on a time-dependent calculation of the trapping process showing that sawtooth activity is caused by the feedback between the low-Z argon and high-Z barium ions. This unexpected behavior demonstrates the importance of nonlinear effects in electron-beam traps containing more than a single ion species

Behavior of cationic, anionic and colloidal species of titanium, zirconium and thorium in presence of ion exchange resins

International Nuclear Information System (INIS)

Souza Filho, G. de; Abrao, A.

1976-01-01

The distribution of titanium, zirconium and thorium is aqueous and resin phases has been studied using strong cationic resin in the R-NH 4 form. Solutions of the above elements in perchloric, nitric, hydrochloric and suphuric media were used. Each set of experiments was made by separately varying one of the five parameters - type of anion present, acidity of solution, temperature of percolation, age of solution and concentration of the element. It was found that, depending on the particular balance of these parameters, the elements investigated may be found in acidic solutions either as cationic, anionic or colloidal species. It is emphasized that the colloidal species of titanium, zirconium or thorium are not retained by the ion exchangers, and from this property a method for the separation and purification of the above elements has been outlined [pt

Quantum Simulation of a Lattice Schwinger Model in a Chain of Trapped Ions

Directory of Open Access Journals (Sweden)

P. Hauke

2013-11-01

Full Text Available We discuss how a lattice Schwinger model can be realized in a linear ion trap, allowing a detailed study of the physics of Abelian lattice gauge theories related to one-dimensional quantum electrodynamics. Relying on the rich quantum-simulation toolbox available in state-of-the-art trapped-ion experiments, we show how one can engineer an effectively gauge-invariant dynamics by imposing energetic constraints, provided by strong Ising-like interactions. Applying exact diagonalization to ground-state and time-dependent properties, we study the underlying microscopic model and discuss undesired interaction terms and other imperfections. As our analysis shows, the proposed scheme allows for the observation in realistic setups of spontaneous parity- and charge-symmetry breaking, as well as false-vacuum decay. Besides an implementation aimed at larger ion chains, we also discuss a minimal setting, consisting of only four ions in a simpler experimental setup, which enables us to probe basic physical phenomena related to the full many-body problem. The proposal opens a new route for analog quantum simulation of high-energy and condensed-matter models where gauge symmetries play a prominent role.

Suppression of self-organized surface nanopatterning on GaSb/InAs multilayers induced by low energy oxygen ion bombardment by using simultaneously sample rotation and oxygen flooding

Science.gov (United States)

Beainy, Georges; Cerba, Tiphaine; Bassani, Franck; Martin, Mickaël; Baron, Thierry; Barnes, Jean-Paul

2018-05-01

Time of flight secondary ion mass spectrometry (ToF-SIMS) is a well-adapted analytical method for the chemical characterization of concentration profiles in layered or multilayered materials. However, under ion beam bombardment, initially smooth material surface becomes morphologically unstable. This leads to abnormal secondary ion yields and depth profile distortions. In this contribution, we explore the surface topography and roughening evolution induced by O2+ ion bombardment on GaSb/InAs multilayers. We demonstrate the formation of nanodots and ripples patterning according to the ion beam energy. Since the latter are undesirable for ToF-SIMS analysis, we managed to totally stop their growth by using simultaneously sample rotation and oxygen flooding. This unprecedented coupling between these two latter mechanisms leads to a significant enhancement in depth profiles resolution.

Toxicity of common ions to marine organisms

International Nuclear Information System (INIS)

Pillard, D.A.; DuFresne, D.L.; Evans, J.

1995-01-01

Produced waters from oil and gas drilling operations are typically very saline, and these may cause acute toxicity to marine organisms due to osmotic imbalances as well as to an excess or deficiency of specific common ions. In order to better understand the relationship between toxicity and ion concentration, laboratory toxicity tests were conducted using mysid shrimp (Mysidopsis bahia), sheepshead minnow (Cyprinodon variegatus), and inland silverside (Menidia beryllina). For each species the ionic concentration of standard laboratory water was proportionally increased or decreased to produce test solutions with a range of salinities. Organisms were exposed for 48 hours. Individual ions (sodium, potassium, calcium, magnetsium, strontium, chloride, bromide, sulfate, bicarbonate, and borate) were also manipulated to examine individual ion toxicity. The three test species differ in their tolerance of salinity. Mysid shrimp show a marked decrease in survival at salinities less than approximately 5 ppt. Both fish species tolerated low salinity water, however, silversides were less tolerant of saline waters (salinity greater than 40 ppt). There were also significant differences in the responses of the organisms to different ions. The results show that the salinity of the test solution may play an important role in the responses of the organisms to the produced water effluent. Predictable toxicity/ion relationships developed in this study can be used to estimate whether toxicity in a produced water is a result of common ions, salinity, or some other unknown toxicant

{sup 1}H and {sup 23}Na MAS NMR spectroscopy of cationic species in CO{sub 2} selective alkaline earth metal porous silicoaluminophosphates prepared via liquid and solid state ion exchange

Energy Technology Data Exchange (ETDEWEB)

Arevalo-Hidalgo, Ana G. [Department of Chemical Engineering, University of Puerto Rico-Mayagueez Campus, Mayagueez, PR 00681-9000 (Puerto Rico); Dugar, Sneha; Fu, Riqiang [National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310 (United States); Hernandez-Maldonado, Arturo J., E-mail: arturoj.hernandez@upr.edu [Department of Chemical Engineering, University of Puerto Rico-Mayagueez Campus, Mayagueez, PR 00681-9000 (Puerto Rico)

2012-07-15

The location of extraframework cations in Sr{sup 2+} and Ba{sup 2+} ion-exchanged SAPO-34 was estimated by means of {sup 1}H and {sup 23}Na MAS NMR spectroscopy and spectral deconvolution. Incorporation of the alkaline earth metal cations onto the SAPO framework was achieved via liquid state ion exchange, coupled partial detemplation/solid-state ion exchange, and combination of both techniques. MAS NMR revealed that the level of ion exchange was limited by the presence of protons and sodium cations near hexagonal prisms (site SI), which are relatively difficult to exchange with the alkaline earth metal due to steric and charge repulsion criteria. In addition, the presence of ammonium cations in the supercages facilitated the exchange of otherwise tenacious hydrogen as corroborated by unit cell compositional data as well as enhanced CO{sub 2} adsorption at low partial pressures. The extraframework ammonium species were produced from partial detemplation of the structure-directing agent employed for the SAPO-34 synthesis, tetraethylammonium. - Graphical abstract: MAS NMR was used to elucidate the position the cationic species in alkaline earth metal exchanged silicoaluminophosphates. These species played a significant role during the ion exchange process and, therefore, the materials ultimate CO{sub 2} adsorption performance. Highlights: Black-Right-Pointing-Pointer Location of extraframework Sr{sup 2+} or Ba{sup 2+} cations was estimated by means of {sup 1}H and {sup 23}Na MAS NMR. Black-Right-Pointing-Pointer Level of Sr{sup 2+} or Ba{sup 2+} ion exchange was limited by the presence of protons and sodium cations. Black-Right-Pointing-Pointer Presence of ammonium cations in the supercages facilitated the exchange. Black-Right-Pointing-Pointer Sr{sup 2+} and Ba{sup 2+} ion exchanged SAPOs are outstanding CO{sub 2} adsorbents.

Development of a compact ECR ion source for various ion production

Energy Technology Data Exchange (ETDEWEB)

Muramatsu, M., E-mail: m-mura@nirs.go.jp; Hojo, S.; Iwata, Y.; Katagiri, K.; Sakamoto, Y.; Kitagawa, A. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Takahashi, N. [Sumitomo Heavy Industries, Ltd., 19 Natsushima, Yokosuka, Kanagawa 237-8555 (Japan); Sasaki, N.; Fukushima, K.; Takahashi, K.; Suzuki, T.; Sasano, T. [Accelerator Engineering Corporation, 3-8-5 Konakadai, Inage, Chiba 263-0043 (Japan); Uchida, T.; Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585 (Japan); Hagino, S.; Nishiokada, T.; Kato, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

2016-02-15

There is a desire that a carbon-ion radiotherapy facility will produce various ion species for fundamental research. Although the present Kei2-type ion sources are dedicated for the carbon-ion production, a future ion source is expected that could provide: (1) carbon-ion production for medical use, (2) various ions with a charge-to-mass ratio of 1/3 for the existing Linac injector, and (3) low cost for modification. A prototype compact electron cyclotron resonance (ECR) ion source, named Kei3, based on the Kei series has been developed to correspond to the Kei2 type and to produce these various ions at the National Institute of Radiological Sciences (NIRS). The Kei3 has an outer diameter of 280 mm and a length of 1120 mm. The magnetic field is formed by the same permanent magnet as Kei2. The movable extraction electrode has been installed in order to optimize the beam extraction with various current densities. The gas-injection side of the vacuum chamber has enough space for an oven system. We measured dependence of microwave frequency, extraction voltage, and puller position. Charge state distributions of helium, carbon, nitrogen, oxygen, and neon were also measured.

Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung Woo; Chung, Byung Yeoup [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, In Chul [Youngdong University, Youngdong (Korea, Republic of)

2011-10-15

Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

International Nuclear Information System (INIS)

Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung Woo; Chung, Byung Yeoup; Lee, In Chul

2011-01-01

Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

Characterization of Lactobacillus brevis L62 strain, highly tolerant to copper ions.

Science.gov (United States)

Mrvčić, Jasna; Butorac, Ana; Solić, Ema; Stanzer, Damir; Bačun-Družina, Višnja; Cindrić, Mario; Stehlik-Tomas, Vesna

2013-01-01

Lactic acid bacteria (LAB) as starter culture in food industry must be suitable for large-scale industrial production and possess the ability to survive in unfavorable processes and storage conditions. Approaches taken to address these problems include the selection of stress-resistant strains. In food industry, LAB are often exposed to metal ions induced stress. The interactions between LAB and metal ions are very poorly investigated. Because of that, the influence of non-toxic, toxic and antioxidant metal ions (Zn, Cu, and Mn) on growth, acid production, metal ions binding capacity of wild and adapted species of Leuconostoc mesenteroides L3, Lactobacillus brevis L62 and Lactobacillus plantarum L73 were investigated. The proteomic approach was applied to clarify how the LAB cells, especially the adapted ones, protect themselves and tolerate high concentrations of toxic metal ions. Results have shown that Zn and Mn addition into MRS medium in the investigated concentrations did not have effect on the bacterial growth and acid production, while copper ions were highly toxic, especially in static conditions. Leuc. mesenteroides L3 was the most efficient in Zn binding processes among the chosen LAB species, while L. plantarum L73 accumulated the highest concentration of Mn. L. brevis L62 was the most copper resistant species. Adaptation had a positive effect on growth and acid production of all species in the presence of copper. However, the adapted species incorporated less metal ions than the wild species. The exception was adapted L. brevis L62 that accumulated high concentration of copper ions in static conditions. The obtained results showed that L. brevis L62 is highly tolerant to copper ions, which allows its use as starter culture in fermentative processes in media with high concentration of copper ions.

Diagnostics for studies of novel laser ion acceleration mechanisms

Energy Technology Data Exchange (ETDEWEB)

Senje, Lovisa; Aurand, Bastian; Wahlström, Claes-Göran [Department of Physics, Lund University, P. O. Box 118, S-221 00 Lund (Sweden); Yeung, Mark; Kuschel, Stephan; Rödel, Christian [Helmholtz-Institut Jena, D-07743 Jena (Germany); Wagner, Florian; Roth, Markus [Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Li, Kun; Neumayer, Paul [ExtreMe Matter Institut, D-64291 Darmstadt (Germany); Dromey, Brendan; Jung, Daniel [Department of Physics and Astronomy, Queen' s University, Belfast BT7 1NN (United Kingdom); Bagnoud, Vincent [Helmholtz-Institut Jena, D-07743 Jena (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Zepf, Matthew [Helmholtz-Institut Jena, D-07743 Jena (Germany); Department of Physics and Astronomy, Queen' s University, Belfast BT7 1NN (United Kingdom); Kuehl, Thomas [ExtreMe Matter Institut, D-64291 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Universität Mainz, D-55099 Mainz (Germany)

2014-11-15

Diagnostic for investigating and distinguishing different laser ion acceleration mechanisms has been developed and successfully tested. An ion separation wide angle spectrometer can simultaneously investigate three important aspects of the laser plasma interaction: (1) acquire angularly resolved energy spectra for two ion species, (2) obtain ion energy spectra for multiple species, separated according to their charge to mass ratio, along selected axes, and (3) collect laser radiation reflected from and transmitted through the target and propagating in the same direction as the ion beam. Thus, the presented diagnostic constitutes a highly adaptable tool for accurately studying novel acceleration mechanisms in terms of their angular energy distribution, conversion efficiency, and plasma density evolution.

Diagnostics for studies of novel laser ion acceleration mechanisms

International Nuclear Information System (INIS)

Senje, Lovisa; Aurand, Bastian; Wahlström, Claes-Göran; Yeung, Mark; Kuschel, Stephan; Rödel, Christian; Wagner, Florian; Roth, Markus; Li, Kun; Neumayer, Paul; Dromey, Brendan; Jung, Daniel; Bagnoud, Vincent; Zepf, Matthew; Kuehl, Thomas

2014-01-01

Diagnostic for investigating and distinguishing different laser ion acceleration mechanisms has been developed and successfully tested. An ion separation wide angle spectrometer can simultaneously investigate three important aspects of the laser plasma interaction: (1) acquire angularly resolved energy spectra for two ion species, (2) obtain ion energy spectra for multiple species, separated according to their charge to mass ratio, along selected axes, and (3) collect laser radiation reflected from and transmitted through the target and propagating in the same direction as the ion beam. Thus, the presented diagnostic constitutes a highly adaptable tool for accurately studying novel acceleration mechanisms in terms of their angular energy distribution, conversion efficiency, and plasma density evolution

When carbon nanotubes encounter the immune system: desirable and undesirable effects.

Science.gov (United States)

Dumortier, Hélène

2013-12-01

The role of our immune system is to bring efficient protection against invasion by foreign elements, not only pathogens but also any material it may be in contact with. Nanoparticles may enter the body and encounter the immune system either intentionally (e.g. administration for biomedical application) or not (e.g. respiratory occupational exposure). Therefore, it is of fundamental importance to get a thorough knowledge of the way they interact with immune cells and all related consequences. Among nanomaterials, carbon nanotubes (CNTs) are of special interest because of their tremendous field of applications. Consequently, their increasing production, processing and eventual incorporation into new types of composites and/or into biological systems have raised fundamental issues regarding their potential impact on health. This review aims at giving an overview of the known desirable and undesirable effects of CNTs on the immune system, i.e. beneficial modulation of immune cells by CNTs engineered for biomedical applications versus toxicity, inflammation and unwanted immune reactions triggered by CNTs themselves. © 2013 Elsevier B.V. All rights reserved.

Amorphization of metals by ion implantation and ion beam mixing

International Nuclear Information System (INIS)

Rauschenbach, B.; Heera, V.

1988-01-01

Amorphous metallic systems can be formed either by high-fluence ion implantation of glassforming species or by irradiation of layered metal systems with inert gas ions. Both techniques and experimental examples are presented. Empirical rules are discussed which predict whether a given system can be transformed into an amorphous phase. Influence of temperature, implantation dose and pre-existing crystalline metal composition on amorphization is considered. Examples are given of the implantation induced amorphous structure, recrystallization and formation of quasicrystalline structures. (author)

Prices and species diversity

DEFF Research Database (Denmark)

Sauer, Johannes

of biodiversity and the appropriate incorporation in stochastic fron-tier models to achieve more realistic measures of production efficiency. We use the empirical example of tobacco production drawing from as well as affecting species diversity in the surrounding forests. We apply a shadow profit distance......In recent decades a significant amount of literature has been produced concerned with establishing a link between production efficiency and environmental efficiency with respect to quantitative modelling. This has been mainly addressed by focusing on the incorporation of undesirable outputs...... or the incorporation of environmentally det-rimental inputs. However, while the debate with respect to linear programming based DEA modelling is already at an advanced stage the corresponding one with respect to stochastic frontier modelling still needs considerable efforts. This contribution fo-cuses on the case...

Compact microwave ion source

International Nuclear Information System (INIS)

Leung, K.N.; Walther, S.; Owren, H.W.

1985-05-01

A small microwave ion source has been fabricated from a quartz tube with one end enclosed by a two grid accelerator. The source is also enclosed by a cavity operated at a frequency of 2.45 GHz. Microwave power as high as 500 W can be coupled to the source plasma. The source has been operated with and without multicusp fields for different gases. In the case of hydrogen, ion current density of 200 mA/cm -2 with atomic ion species concentration as high as 80% has been extracted from the source

Generation lifetime investigation of ion-damage gettered silicon using MOS structure

International Nuclear Information System (INIS)

Nassibian, A.G.; Browne, V.A.; Perkins, K.D.

1976-01-01

Gettering of undesirable generation impurities by O and Ar implant damage layer has been investigated by transient response of MOS capacitors. One-half of each Si wafer was masked against the implanting ion beam and comparison was made between the two halves of each wafer by deducing the generation lifetime from the C-t measurements. The implant dosage was 10 16 cm -2 and ion energy 200 keV. The gettering anneal at 1070 0 C was also the gate oxidation. The generation lifetime from 1 to 15 μs of the control half was increased to as high as 200 μs after both O and Ar implants. The results with O were more reproducible than with the Ar-implanted Si wafers; however, the largest increase in generation lifetime was observed with the Ar getterered wafer. It is proposed that there are generation centers other than the generation impurity centers that cannot be removed by gettering methods

Characteristics of a multidipole ion source

International Nuclear Information System (INIS)

Leung, K.N.; Collier, R.D.; Marshall, L.B.; Gallaher, T.N.; Ingham, W.H.; Kribel, R.E.; Taylor, G.R.

1978-01-01

The properties of a steady-state, dc discharge multidipole ion source have been investigated. The plasma density in the source depends on the magnet geometries, the discharge voltage, and the bias voltage on the first extraction grid. Different schemes to reduce the loss of ions to the chamber wall are described. Hydrogen ion species in the extracted beam are studied by a mass analyzer

New Insights of Graphite Anode Stability in Rechargeable Batteries: Li-Ion Coordination Structures Prevail over Solid Electrolyte Interphases

KAUST Repository

Ming, Jun

2018-01-04

Graphite anodes are not stable in most noncarbonate solvents (e.g., ether, sulfoxide, sulfone) upon Li ion intercalation, known as an urgent issue in present Li ions and next-generation Li–S and Li–O2 batteries for storage of Li ions within the anode for safety features. The solid electrolyte interphase (SEI) is commonly believed to be decisive for stabilizing the graphite anode. However, here we find that the solvation structure of the Li ions, determined by the electrolyte composition including lithium salts, solvents, and additives, plays a more dominant role than SEI in graphite anode stability. The Li ion intercalation desired for battery operation competes with the undesired Li+–solvent co-insertion, leading to graphite exfoliation. The increase in organic lithium salt LiN(SO2CF3)2 concentration or, more effectively, the addition of LiNO3 lowers the interaction strength between Li+ and solvents, suppressing the graphite exfoliation caused by Li+–solvent co-insertion. Our findings refresh the knowledge of the well-known SEI for graphite stability in metal ion batteries and also provide new guidelines for electrolyte systems to achieve reliable and safe Li–S full batteries.

Effects of the instability enhanced friction on relative ion densities in a two-ion species low-temperature plasma

Science.gov (United States)

Vukovic, Mirko

2011-10-01

The instability enhanced friction theory of Baalrud & Hegna (Phys. Plasmas 18, 023505 (2011)) predicts that for comparable ion densities the ions nearly reach a common velocity near the sheath edge in a low temperature plasma. The theory was experimentally confirmed by Yip, Hershkowitz, & Severn (Phys. Rev. Letters 104, 225003 (2010)). We will explore the effects of the theory on relative ion densities in a numerical simulation of an Ar/Xe plasma. Results for a 0D plasma model (Lieberman, Lichtenberg, Principles of Plasma Discharges and Materials Processing, 2005) will be presented.

Observations of Heavy Ions in the Magnetosphere

Science.gov (United States)

Kistler, L. M.

2017-12-01

There are two sources for the hot ions in the magnetosphere: the solar wind and the ionosphere. The solar wind is predominantly protons, with about 4% He++ and less than 1% other high charge state heavy ions. The ionospheric outflow is also predominantly H+, but can contain a significant fraction of heavy ions including O+, N+, He+, O++, and molecular ions (NO+, N2+, O2+). The ionospheric outflow composition varies significantly both with geomagnetic activity and with solar EUV. The variability in the contribution of the two sources, the variability in the ionospheric source itself, and the transport paths of the different species are all important in determining the ion composition at a given location in the magnetosphere. In addition to the source variations, loss processes within the magnetosphere can be mass dependent, changing the composition. In particular, charge exchange is strongly species dependent, and can lead to heavy ion dominance at some energies in the inner magnetosphere. In this talk we will review the current state of our understanding of the composition of the magnetosphere and the processes that determine it.

Ion-exclusion/cation-exchange chromatography with dual detection of the conductivity and spectrophotometry for the simultaneous determination of common inorganic anionic species and cations in river and wastewater.

Science.gov (United States)

Nakatani, Nobutake; Kozaki, Daisuke; Mori, Masanobu; Hasebe, Kiyoshi; Nakagoshi, Nobukazu; Tanaka, Kazuhiko

2011-01-01

Simultaneous determinations of common inorganic anionic species (SO(4)(2-), Cl(-), NO(3)(-), phosphate and silicate) and cations (Na(+), NH(4)(+), K(+), Mg(2+) and Ca(2+)) were conducted using an ion-chromatography system with dual detection of conductivity and spectrophotometry in tandem. The separation of ionic species on a weakly acidic cation-exchange resin was accomplished using a mixture of 100 mM ascorbic acid and 4 mM 18-crown-6 as an acidic eluent (pH 2.6), after which the ions were detected using a conductivity detector. Subsequently, phosphate and silicate were analyzed based on derivatization with molybdate and spectrophotometry at 700 nm. The detection limits at S/N = 3 ranged from 0.11 to 2.9 µM for analyte ionic species. This method was applied to practical river water and wastewater with acceptable criteria for the anion-cation balance and comparisons of the measured and calculated electrical conductivity, demonstrating the usefulness of the present method for water quality monitoring.

Plasma immersion surface modification with metal ion plasma

International Nuclear Information System (INIS)

Brown, I.G.; Yu, K.M.; Godechot, X.

1991-04-01

We describe here a novel technique for surface modification in which metal plasma is employed and by which various blends of plasma deposition and ion implantation can be obtained. The new technique is a variation of the plasma immersion technique described by Conrad and co-workers. When a substrate is immersed in a metal plasma, the plasma that condenses on the substrate remains there as a film, and when the substrate is then implanted, qualitatively different processes can follow, including' conventional' high energy ion implantation, recoil implantation, ion beam mixing, ion beam assisted deposition, and metallic thin film and multilayer fabrication with or without species mixing. Multiple metal plasma guns can be used with different metal ion species, films can be bonded to the substrate through ion beam mixing at the interface, and multilayer structures can be tailored with graded or abrupt interfaces. We have fabricated several different kinds of modified surface layers in this way. 22 refs., 4 figs

Mutation induction of orchids by ion beams

International Nuclear Information System (INIS)

Affrida Abu Hassan; Zaiton Ahmad; Sakinah Ariffin; Oono, Yutaka; Hase, Yoshihiro; Shikazono; Naoya; Narumi, Issay; Tanaka, Atsushi

2010-01-01

Mutation induction using ionizing radiation provides an effective alternative means for improvement of orchids. In this study, ion beams were used because they have much higher linear energy transfer (LET) than X-rays or gamma rays, and subsequently lead to higher mutation frequency and broad mutation spectrum. The proto corm-like bodies (PLBs) of three orchid species (Dendrobium crumenatum, Dendrobium mirbellianum) were irradiated at various doses with 320 MeV 12 C 6+ ions accelerated by Azimuthally Varying Field (AVF) cyclotron at JAEAs Takasaki Ion Accelerators for Advanced Radiation Application (TIARA). The optimum irradiation condition and the effect of irradiation on each species were studied, particularly on flower colour and morphology, flowering habit and insect resistance. Dose effects on plantlet regeneration for each species were also obtained. Some morphological changes were observed in flowers of Dendrobium crumenatum, whilst one insect resistant mutant was obtained in Dendrobium mirbellianum. (author)

Thorium molecular negative ion production in a cesium sputter source at BARC-TIFR pelletron accelerator ion source test set up

International Nuclear Information System (INIS)

Gupta, A.K.; Mehrotra, N.; Kale, R.M.; Alamelu, D.; Aggarwal, S.K.

2005-01-01

Ion source test set up at Pelletron Accelerator facility has been utilized extensively for the production and characterization of negative ions, with particular emphasis being place at the species of experimental users interest. The attention have been focussed towards the formation of rare earth negative ions, due to their importance in the ongoing accelerator mass spectroscopy program and isotopic abundance measurements using secondary negative ion mass spectrometry

Ion beam application for improved polymer surface properties

International Nuclear Information System (INIS)

Lee, E.H.; Rao, G.R.; Lewis, M.B.; Mansur, L.K.

1992-01-01

Various polymeric materials were subjected to bombardment by different energetic ions with energies ranging from 200 to 1000 keV. Tests showed substantial improvements in hardness, wear resistance, oxidation resistance, resistance to chemicals, and electrical conductivity. The magnitude of property changes was strongly dependent upon ion species, energy, dose, and polymer structure. Both hardness and electrical conductivity increased with ion energy and dose. These properties were apparently related to the effectiveness of cross-linking. Ion species with a large electronic stopping cross-section are expected to produce more crosslinking. It is believed that the polymer property improvements are commensurate with the extent of crosslinking, which is responsible for the formation of three-dimensionally-connected, carbon-rich, rigid networks. 22 refs, 5 figs

Ion irradiation studies of oxide ceramics

International Nuclear Information System (INIS)

Zinkle, S.J.

1988-01-01

This paper presents the initial results of an investigation of the depth-dependent microstructures of three oxide ceramics following ion implantation to moderate doses. The implantations were performed using ion species that occur as cations in the target material; for example, Mg + ions were used for MgO and MgAl 2 O 4 (spinel) irradiations. This minimized chemical effects associated with the implantation and allowed a more direct evaluation to be made of the effects of implanted ions on the microstructure. 11 refs., 14 figs

Adhesion of silver films to ion-bombarded alumina

International Nuclear Information System (INIS)

Erck, R.A.; Fenske, G.R.

1990-01-01

This paper reports on silver films deposited on alumina substrates using ion bombardment. Adhesion strength was measured as a function of deposition conditions, sputter-cleaning time, and bombarding ion species, using a pull-type adhesion tester. Argon- and argon/oxygen-ion sputtering produced large increases in adhesion strength, with the greatest increases occurring for oxygen-ion bombardment. Adhesion strength increased monotonically as a function of ion sputtering time. At a given deposition rate, further enhancement of adhesion is seen with concurrent ion bombardment

Kinetic effects in Alfven and ion-cyclotron-wave propagation: Surface eigenmodes and impurity effects

International Nuclear Information System (INIS)

Li Wannquan.

1989-01-01

In a circular cylindrical geometry, the author solves a fourth-order set of differential equations numerically for the perturbed fields E τ and E perpendicular . The model takes into account the equilibrium current, magnetic shear, finite ω/ω c1 effect, mode conversion effects like finite ion gyroradius and electron inertia, and various dissipative mechanisms such as electron Landau and collisional damping, and minority fundamental and majority second harmonic cyclotron absorption. To illustrate the results, the author plots the perturbed electric fields and the energy absorbed by each species. He first examines cold plasma surface Alfven eigenmodes analytically and numerically in a pure plasma. The motivation for this work is to investigate how to avoid the undesirable edge absorption and introduce the methods for the study of impurity effects. In the two-species plasmas, he considers three special examples: (1) minority oxygen in hydrogen in PRETEXT, (2) minority T or H in deuterium in TFTR. He adopts two models: (i) a radially varying minority charge, or (ii) a radially varying magnetic field to investigate the minority gyroresonance heating. The model (ii) is used to examine these three examples. But the model (i) is only applied to the first one. In model (i), it is found that surface modes can induce the eigenmodes and dissipate substantial energy near the hybrid layer in the interior. Some cases analytically manageable are given an interpretation of why there is large or small energy deposition in this layer. It is shown that this strongly depends on poloidal mode numbers, minority concentrations, and minority charge profiles

Electron string ion sources for carbon ion cancer therapy accelerators

Science.gov (United States)

Boytsov, A. Yu.; Donets, D. E.; Donets, E. D.; Donets, E. E.; Katagiri, K.; Noda, K.; Ponkin, D. O.; Ramzdorf, A. Yu.; Salnikov, V. V.; Shutov, V. B.

2015-08-01

The type of the Electron String Ion Sources (ESIS) is considered to be the appropriate one to produce pulsed C4+ and C6+ ion beams for cancer therapy accelerators. In fact, the new test ESIS Krion-6T already now provides more than 1010 C4+ ions per pulse and about 5 × 109 C6+ ions per pulse. Such ion sources could be suitable to apply at synchrotrons. It has also been found that Krion-6T can provide more than 1011 C6+ ions per second at the 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. ESIS can be also a suitable type of ion source to produce the 11C radioactive ion beams. A specialized cryogenic cell was experimentally tested at the Krion-2M ESIS for pulse injection of gaseous species into the electron string. It has been shown in experiments with stable methane that the total conversion efficiency of methane molecules to C4+ ions reached 5%÷10%. For cancer therapy with simultaneous irradiation and precise dose control (positron emission tomography) by means of 11C, transporting to the tumor with the primary accelerated 11C4+ beam, this efficiency is preliminarily considered to be large enough to produce the 11C4+ beam from radioactive methane and to inject this beam into synchrotrons.

Super TOF secondary ion mass spectroscopy using very highly charged primary ions up to Th70+

International Nuclear Information System (INIS)

Briere, M.A.; Schenkel, T.; Schneider, D.

1995-01-01

The LLNL Electron Beam Ion Trap (EBIT) has made low emittance beams of slow highly charged ions available for ion-solid interaction studies. Such interactions feature the dominance of electronic over collisional effects, and the shock waves generated by the ionized target atoms can desorb large numbers of large molecular species from the surface. This paper presents the first systematic study of the sputtering process due to the incidence of slow very highly charged ions; Th 70+ ions are extracted from EBIT at 7 keV * q and directed onto thin SiO 2 films on Si. Results suggest secondary ion yields of up to 25 per incident ion for Th 70+ (secondary ion yield is increased over that for singly or moderately charged ions). Correlations of the negative, positive, and negative cluster ion yields show promise for application of highly charged ion induced sputtering for enhanced sensitivity and quantitative (absolute) SIMS analysis of deep submicron scale surface layers and polymeric and biomolecular material analysis

An equation for the prediction of human skin permeability of neutral molecules, ions and ionic species.

Science.gov (United States)

Zhang, Keda; Abraham, Michael H; Liu, Xiangli

2017-04-15

Experimental values of permeability coefficients, as log K p , of chemical compounds across human skin were collected by carefully screening the literature, and adjusted to 37°C for the effect of temperature. The values of log K p for partially ionized acids and bases were separated into those for their neutral and ionic species, forming a total data set of 247 compounds and species (including 35 ionic species). The obtained log K p values have been regressed against Abraham solute descriptors to yield a correlation equation with R 2 =0.866 and SD=0.432 log units. The equation can provide valid predictions for log K p of neutral molecules, ions and ionic species, with predictive R 2 =0.858 and predictive SD=0.445 log units calculated by the leave-one-out statistics. The predicted log K p values for Na + and Et 4 N + are in good agreement with the observed values. We calculated the values of log K p of ketoprofen as a function of the pH of the donor solution, and found that log K p markedly varies only when ketoprofen is largely ionized. This explains why models that neglect ionization of permeants still yield reasonable statistical results. The effect of skin thickness on log K p was investigated by inclusion of two indicator variables, one for intermediate thickness skin and one for full thickness skin, into the above equation. The newly obtained equations were found to be statistically very close to the above equation. Therefore, the thickness of human skin used makes little difference to the experimental values of log K p . Copyright © 2017 Elsevier B.V. All rights reserved.

Compact ion accelerator source

Science.gov (United States)

Schenkel, Thomas; Persaud, Arun; Kapadia, Rehan; Javey, Ali

2014-04-29

An ion source includes a conductive substrate, the substrate including a plurality of conductive nanostructures with free-standing tips formed on the substrate. A conductive catalytic coating is formed on the nanostructures and substrate for dissociation of a molecular species into an atomic species, the molecular species being brought in contact with the catalytic coating. A target electrode placed apart from the substrate, the target electrode being biased relative to the substrate with a first bias voltage to ionize the atomic species in proximity to the free-standing tips and attract the ionized atomic species from the substrate in the direction of the target electrode.

Fully nonlinear heavy ion-acoustic solitary waves in astrophysical degenerate relativistic quantum plasmas

Science.gov (United States)

Sultana, S.; Schlickeiser, R.

2018-05-01

Fully nonlinear features of heavy ion-acoustic solitary waves (HIASWs) have been investigated in an astrophysical degenerate relativistic quantum plasma (ADRQP) containing relativistically degenerate electrons and non-relativistically degenerate light ion species, and non-degenerate heavy ion species. The pseudo-energy balance equation is derived from the fluid dynamical equations by adopting the well-known Sagdeev-potential approach, and the properties of arbitrary amplitude HIASWs are examined. The small amplitude limit for the propagation of HIASWs is also recovered. The basic features (width, amplitude, polarity, critical Mach number, speed, etc.) of HIASWs are found to be significantly modified by the relativistic effect of the electron species, and also by the variation of the number density of electron, light ion, and heavy ion species. The basic properties of HIASWs, that may propagated in some realistic astrophysical plasma systems (e.g., in white dwarfs), are briefly discussed.

Production of rare-earth atomic negative ion beams in a cesium-sputter-type negative ion source

International Nuclear Information System (INIS)

Davis, V.T.; Covington, A.M.; Duvvuri, S.S.; Kraus, R.G.; Emmons, E.D.; Kvale, T.J.; Thompson, J.S.

2007-01-01

The desire to study negative ion structure and negative ion-photon interactions has spurred the development of ion sources for use in research and industry. The many different types of negative ion sources available today differ in their characteristics and abilities to produce anions of various species. Thus the importance of choosing the correct type of negative ion source for a particular research or industrial application is clear. In this study, the results of an investigation on the production of beams composed of negatively-charged rare-earth ions from a cylindrical-cathode-geometry, cesium-sputter-type negative ion source are presented. Beams of atomic anions have been observed for most of the first-row rare-earth elements, with typical currents ranging from hundreds of picoamps to several nanoamps

Heating of Solar Wind Ions via Cyclotron Resonance

Science.gov (United States)

Navarro, R.; Moya, P. S.; Figueroa-Vinas, A.; Munoz, V.; Valdivia, J. A.

2017-12-01

Remote and in situ observations in the solar wind show that ion and electron velocity distributions persistently deviate from thermal equilibrium in the form of relative streaming between species components, temperature anisotropy, etc. These non-thermal features represent a source of free energy for the excitation of kinetic instabilities and fluctuations in the plasma. In this regard, it is believed that plasma particles can be heated, through a second order Fermi acceleration process, by multiple resonances with unstable counter-propagating field-aligned Ion-cyclotron waves. For multi-species plasmas, several collective wave modes participate in this process. In this work, we test this model by studying the percentage of ions that resonate with the waves modes described by the proper kinetic multi-species dispersion relation in a solar-wind-like plasma composed of electrons, protons, and alpha particles. Numerical results are compared with WIND spacecraft data to test its relevance for the existence of thresholds for the preferential perpendicular heating of He+2 ions as observed in the solar wind fast streams.

[Determination of iodine and its species in plant samples using ion chromatography-inductively coupled plasma mass spectrometry].

Science.gov (United States)

Lin, Li; Chen, Guang; Chen, Yuhong

2011-07-01

A method was established for the determination of iodine and its species in plant samples using ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP/ MS). Alkaline extraction and IC-ICP/MS were applied as the sample pre-treatment method and the detection technique respectively, for iodate and iodide determination. Moreover, high-temperature pyrolysis absorption was adopted as the pre-treatment method for total iodine analysis, which finally converted all the iodine species into iodide and measured the iodide by IC-ICP/MS. The recoveries of iodine for alkaline extraction and high-temperature pyrolysis absorption were 89.6%-97.5% and 95.2%-111.2%, respectively. The results were satisfactory. The detection limit of iodine was 0.010 mg/kg. The iodine and its speciation contents in several kinds of plant samples such as seaweeds, kelp, cabbage, tea leaf and spinach were investigated. It was shown that the iodine in seaweeds mainly existed as organic iodine; while the ones in kelp, cabbage, tea leaf and spinach mainly existed as inorganic iodine.

Ions in carbon dioxide at an atmospheric pressure

International Nuclear Information System (INIS)

Ikezoe, Yasumasa; Onuki, Kaoru; Shimizu, Saburo; Nakajima, Hayato; Sato, Shoichi; Matsuoka, Shingo; Nakamura, Hirone; Tamura, Takaaki

1985-01-01

The formation and the subsequent reactions of positive and negative ions were observed by a time resolved atmospheric pressure ionization mass spectrometer (TRAPI) in an atmospheric pressure carbon dioxide added with small amounts of carbon monoxide and oxygen. A relatively stable ion of (44 x n) + (n >= 2) having a different reactivity from that of (CO 2 ) + sub(n) was found to be one of major ionic species in this gas system. This species was tentatively assigned as [O 2 (CO) 2 ] + (CO 2 )sub(n-2). A new reaction sequence of positive ions is proposed which can be operative in the radiolysis of carbon dioxide at 1 atm. (author)

Redox-assisted Li+-storage in lithium-ion batteries

International Nuclear Information System (INIS)

Huang Qizhao; Wang Qing

2016-01-01

Interfacial charge transfer is the key kinetic process dictating the operation of lithium-ion battery. Redox-mediated charge propagations of the electronic (e − and h + ) and ionic species (Li + ) at the electrode–electrolyte interface have recently gained increasing attention for better exploitation of battery materials. This article briefly summarises the energetic and kinetic aspects of lithium-ion batteries, and reviews the recent progress on various redox-assisted Li + storage approaches. From molecular wiring to polymer wiring and from redox targeting to redox flow lithium battery, the role of redox mediators and the way of the redox species functioning in lithium-ion batteries are discussed. (topical review)

Pick-Up Ion Instabilities at Planetary Magnetospheres

Science.gov (United States)

Strangeway, Robert J.; Sharber, James (Technical Monitor)

2001-01-01

This effort involved the analysis of low frequency waves as observed by the Galileo spacecraft near the Galilean moon, Io. Io is a significant source of material, especially SO2, and various products of dissociation, and further these atoms and molecules are readily ionized. The initial velocity of the ions is essentially that of the neutral species, i.e., the Keplerian velocity. The plasma, on the other hand is co-rotating, and there is a differential flow of the order 57 km/s between the plasma and the neutral particles. Thus pick-up ion instabilities are Rely to occur within the Jovian magnetosphere. Indeed, magnetometer observations from the Galileo spacecraft clearly show ion cyclotron waves that have been identified with a large variety of plasma species, such as O+, S++ (which has the same gyro-frequency as O+), S+, and SO2+. Typically, however, the dominant frequency is near the SO2+ gyro-frequency. The research effort was originally planned to be a team effort between Robert J. Strangeway as the Principal Investigator, and Debbie Huddleston, who was an Assistant Research Geophysicist at UCLA. Unfortunately, Dr. Huddleston took a position within Industry. The effort was therefore descoped, and Dr. Strangeway instead pursued a collaboration with Dr. Xochitl Blanco-Cano, of the Instituto de Geofisica, Universidad Nacional Autonoma de Mexico. This has proved to be a productive collaboration, with several papers and publications arising out of the effort. The magnetic field oscillations near lo generally fall into two types: ion cyclotron waves, with frequencies near an ion gyro-frequency, and lower frequency mirror-mode waves. The ion cyclotron waves are mainly transverse, and frequently propagate along the ambient magnetic field. The mirror-mode waves are compressional waves, and they have essentially zero frequency in the plasma rest frame. One of the purposes of our investigation is to understand what controls the types of wave modes that occur, since both

Luminescence enhancement of uranyl ion by benzoic acid in acetonitrile

International Nuclear Information System (INIS)

Satendra Kumar; Maji, S.; Joseph, M.; Sankaran, K.

2014-01-01

Uranyl ion is known for its characteristic green luminescence and therefore luminescence spectroscopy is a suitable technique for characterizing different uranyl species. In aqueous medium, luminescence of uranyl ion is generally weak due to its quenching by water molecules and therefore in order to enhance the luminescence of uranyl ion in aqueous medium, luminescence enhancing reagents such as H 3 PO 4 , H 2 SO 4 , HCIO 4 have been widely used. The other method to enhance the uranyl luminescence is by ligand sensitized luminescence, a method well established for lanthanides. In this work, luminescence of uranyl ion is found to be enhanced by benzoic acid in acetonitrile medium. In aqueous medium benzoic acid does not enhance the uranyl luminescence although it forms 1:1 and 1:2 complexes with uranyl ion. Luminescence spectra of uranyl benzoate revealed that enhancement is due to sensitization of uranyl luminescence by benzoate ions. UV-Vis spectroscopy has been utilized to characterize the specie formed in the in acetonitrile medium. UV-Vis spectroscopy along with luminescence spectra revealed that the specie to be tribenzoate complex of uranyl (UO 2 (C 6 H 5 COO) 3 ) - having D 3 h symmetry. (author)

Electron string ion sources for carbon ion cancer therapy accelerators

Energy Technology Data Exchange (ETDEWEB)

Boytsov, A. Yu.; Donets, D. E.; Donets, E. D.; Donets, E. E.; Ponkin, D. O.; Ramzdorf, A. Yu.; Salnikov, V. V.; Shutov, V. B. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Katagiri, K.; Noda, K. [National Institute of Radiological Science, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

2015-08-15

The type of the Electron String Ion Sources (ESIS) is considered to be the appropriate one to produce pulsed C{sup 4+} and C{sup 6+} ion beams for cancer therapy accelerators. In fact, the new test ESIS Krion-6T already now provides more than 10{sup 10} C{sup 4+} ions per pulse and about 5 × 10{sup 9} C{sup 6+} ions per pulse. Such ion sources could be suitable to apply at synchrotrons. It has also been found that Krion-6T can provide more than 10{sup 11} C{sup 6+} ions per second at the 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. ESIS can be also a suitable type of ion source to produce the {sup 11}C radioactive ion beams. A specialized cryogenic cell was experimentally tested at the Krion-2M ESIS for pulse injection of gaseous species into the electron string. It has been shown in experiments with stable methane that the total conversion efficiency of methane molecules to C{sup 4+} ions reached 5%÷10%. For cancer therapy with simultaneous irradiation and precise dose control (positron emission tomography) by means of {sup 11}C, transporting to the tumor with the primary accelerated {sup 11}C{sup 4+} beam, this efficiency is preliminarily considered to be large enough to produce the {sup 11}C{sup 4+} beam from radioactive methane and to inject this beam into synchrotrons.

Asymmetric ion trap

Science.gov (United States)

Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

1997-01-01

An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

Long range implantation by MEVVA metal ion source

International Nuclear Information System (INIS)

Zhang Tonghe; Wu Yuguang; Ma Furong; Liang Hong

2001-01-01

Metal vapor vacuum arc (MEVVA) source ion implantation is a new technology used for achieving long range ion implantation. It is very important for research and application of the ion beam modification of materials. The results show that the implanted atom diffusion coefficient increases in Mo implanted Al with high ion flux and high dose. The implanted depth is 311.6 times greater than that of the corresponding ion range. The ion species, doses and ion fluxes play an important part in the long-range implantation. Especially, thermal atom chemistry have specific effect on the long-range implantation during high ion flux implantation at transient high target temperature

Tracking Progress in Improving Diagnosis: A Framework for Defining Undesirable Diagnostic Events.

Science.gov (United States)

Olson, Andrew P J; Graber, Mark L; Singh, Hardeep

2018-01-29

Diagnostic error is a prevalent, harmful, and costly phenomenon. Multiple national health care and governmental organizations have recently identified the need to improve diagnostic safety as a high priority. A major barrier, however, is the lack of standardized, reliable methods for measuring diagnostic safety. Given the absence of reliable and valid measures for diagnostic errors, we need methods to help establish some type of baseline diagnostic performance across health systems, as well as to enable researchers and health systems to determine the impact of interventions for improving the diagnostic process. Multiple approaches have been suggested but none widely adopted. We propose a new framework for identifying "undesirable diagnostic events" (UDEs) that health systems, professional organizations, and researchers could further define and develop to enable standardized measurement and reporting related to diagnostic safety. We propose an outline for UDEs that identifies both conditions prone to diagnostic error and the contexts of care in which these errors are likely to occur. Refinement and adoption of this framework across health systems can facilitate standardized measurement and reporting of diagnostic safety.

Multivalent ion conducting solids

Energy Technology Data Exchange (ETDEWEB)

Imanaka, N. [Osaka Univ., Suita, Osaka (Japan). Dept. of Applied Chemistry

2008-07-01

Solid electrolytes possess important characteristics for industrial applications. Only a single ionic species can macroscopically migrate in these solids. This paper described a the new NASICON (M-Zr-Nb-P-O) type system, exhibiting an exceptionally high level of trivalent M3+ ion conductivity on polycrystalline solids. The partial substitution of the smaller higher valent Nb5+ ion for Zr4+ stabilized the NASICON phase and realized the M3+ ion conduction in the NASICON structure. It was concluded that the conductivities of the series are comparable to those of the practically applied solid electrolytes of oxide anion conductors of YSZ and CSZ. 3 refs., 2 figs.

Recent developments of ion sources for life-science studies at the Heavy Ion Medical Accelerator in Chiba (invited)

Energy Technology Data Exchange (ETDEWEB)

Kitagawa, A.; Drentje, A. G.; Fujita, T.; Muramatsu, M. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Fukushima, K.; Shiraishi, N.; Suzuki, T.; Takahashi, K.; Takasugi, W. [Accelerator Engineering Corporation, Chiba (Japan); Biri, S.; Rácz, R. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Kato, Y. [Graduate School of Engineering, Osaka University, Osaka (Japan); Uchida, T.; Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe (Japan)

2016-02-15

With about 1000-h of relativistic high-energy ion beams provided by Heavy Ion Medical Accelerator in Chiba, about 70 users are performing various biology experiments every year. A rich variety of ion species from hydrogen to xenon ions with a dose rate of several Gy/min is available. Carbon, iron, silicon, helium, neon, argon, hydrogen, and oxygen ions were utilized between 2012 and 2014. Presently, three electron cyclotron resonance ion sources (ECRISs) and one Penning ion source are available. Especially, the two frequency heating techniques have improved the performance of an 18 GHz ECRIS. The results have satisfied most requirements for life-science studies. In addition, this improved performance has realized a feasible solution for similar biology experiments with a hospital-specified accelerator complex.

Effect of Ion Flux (Dose Rate) in Source-Drain Extension Ion Implantation for 10-nm Node FinFET and Beyond on 300/450mm Platforms

Science.gov (United States)

Shen, Ming-Yi

The improvement of wafer equipment productivity has been a continuous effort of the semiconductor industry. Higher productivity implies lower product price, which economically drives more demand from the market. This is desired by the semiconductor manufacturing industry. By raising the ion beam current of the ion implanter for 300/450mm platforms, it is possible to increase the throughput of the ion implanter. The resulting dose rate can be comparable to the performance of conventional ion implanters or higher, depending on beam current and beam size. Thus, effects caused by higher dose rate must be investigated further. One of the major applications of ion implantation (I/I) is source-drain extension (SDE) I/I for the silicon FinFET device. This study investigated the dose rate effects on the material properties and device performance of the 10-nm node silicon FinFET. In order to gain better understanding of the dose rate effects, the dose rate study is based on Synopsys Technology CAD (TCAD) process and device simulations that are calibrated and validated using available structural silicon fin samples. We have successfully shown that the kinetic monte carlo (KMC) I/I simulation can precisely model both the silicon amorphization and the arsenic distribution in the fin by comparing the KMC simulation results with TEM images. The results of the KMC I/I simulation show that at high dose rate more activated arsenic dopants were in the source-drain extension (SDE) region. This finding matches with the increased silicon amorphization caused by the high dose-rate I/I, given that the arsenic atoms could be more easily activated by the solid phase epitaxial regrowth process. This increased silicon amorphization led to not only higher arsenic activation near the spacer edge, but also less arsenic atoms straggling into the channel. Hence, it is possible to improve the throughput of the ion implanter when the dopants are implanted at high dose rate if the same doping level

Influence of ion beam and geometrical parameters on properties of Si thin films grown by Ar ion beam sputtering

Energy Technology Data Exchange (ETDEWEB)

Bundesmann, Carsten; Feder, Rene; Neumann, Horst [Leibniz-Institut fuer Oberflaechenmodifizierung e.V., Leipzig (Germany)

2012-07-01

Ion beam sputtering (IBS) offers, in contrast to other physical vapour deposition techniques, such as magnetron sputtering or electron beam evaporation, the opportunity to change the properties of the layer forming particles (sputtered and scattered particles) by varying ion beam parameters (ion species, ion energy) and geometrical parameters (ion incidence angle, emission angle). Consequently, these effects can be utilized to tailor thin film properties [1]. The goal is to study systematically the correlations between the primary and secondary parameters and, at last, the effects on the properties of Si thin films, such as optical properties, stress, surface topography and composition. First experimental results are presented for Ar-ion sputtering of Si.

Simultaneous determination of arsenic and mercury species in rice by ion-pairing reversed phase chromatography with inductively coupled plasma mass spectrometry.

Science.gov (United States)

Fang, Yong; Pan, Yushi; Li, Peng; Xue, Mei; Pei, Fei; Yang, Wenjian; Ma, Ning; Hu, Qiuhui

2016-12-15

An analytical method using reversed phase chromatography-inductively coupled plasma mass spectrometry for arsenic and mercury speciation analysis was described. The effect of ion-pairing reagent on simultaneous separation of four arsenic (arsenite, arsenate, monomethlyarsonate and dimethylarsinate) and three mercury species (inorganic mercury (Hg(II)), methylmecury and ethylmercury) was investigated. Parameters including concentrations and pH of the mobile phase were optimized. The separation and re-equilibration time was attained within 20min. Meanwhile, a sequential extraction method for arsenic and mercury in rice was tested. Subsequently, 1% HNO3 microwave-assisted extraction was chosen. Calibration curves based on peak area measurements were linear with correlation coefficient greater than 0.9958 for each species in the range studied. The detection limits of the species were in the range of 0.84-2.41μg/L for arsenic and 0.01-0.04μg/L for mercury, respectively. The proposed method was then successfully applied for the simultaneous determination of arsenic and mercury species in rice flour standard material and two kinds of rice from local markets. Copyright © 2016 Elsevier Ltd. All rights reserved.

Landau damping in bi-dust ion-acoustic waves

International Nuclear Information System (INIS)

Castro, E.; Puerta, J.; Martin, P.; Cereceda, C.

2006-01-01

Ion acoustic dust waves in a bi-dust plasma are analyzed in this paper. In order to model this system, we assume the existence of two different kinds of grains, each characterized by a different radius. Relative velocities between grains and charge fluctuations are neglected. In order to derive the dispersion relation of this system, we use the well known hybrid fluid-kinetic model, in which ions are treated kinetically and other species as fluids. In this plasma, waves with non-relative velocities between species leads to damped waves with frequency modes, defined by the grain radius. The induced damping ratio is studied as a function of the grain and ion densities. (Author)

Parametrics for Molecular Deuterium Concentrations in the Source Region of the UW-IEC Device Using an Ion Acoustic Wave Diagnostic

Science.gov (United States)

Boris, D. R.; Emmert, G. A.

2007-11-01

The ion source region of the UW-Inertial Electrostatic Confinement device is comprised of a filament assisted DC discharge plasma that exists between the wall of the IEC vacuum chamber and the grounded spherical steel grid that makes up the anode of the IEC device. A 0-dimensional rate equation calculation of the molecular deuterium ion species concentration has been applied utilizing varying primary electron energy, and neutral gas pressure. By propagating ion acoustic waves in the source region of the IEC device the concentrations of molecular deuterium ion species have been determined for these varying plasma conditions, and high D3^+ concentrations have been verified. This was done by utilizing the multi-species ion acoustic wave dispersion relation, which relates the phase speed of the multi-species ion acoustic wave, vph, to the sum in quadrature of the concentration weighted ion acoustic sound speeds of the individual ion species.

Two Contemporary Problems in Magnetized Plasmas: the ion-ion hybrid resonator and MHD stability in a snowflake divertor

Energy Technology Data Exchange (ETDEWEB)

Farmer, William Anthony [Univ. of California, Los Angeles, CA (United States)

2014-01-01

The rst part of the dissertation investigates the e ects of multiple-ions on the propagation of shear Alfv en waves. It is shown that the presence of a second ion-species allows for the formation of an ion-ion hybrid resonator in the presence of a magnetic well. A fullwave description is shown to explain the measured eigenfrequencies and spatial form of the resonator modes identi ed in experiments in the Large Plasma Device (LAPD) at UCLA. However, it is determined that neither electron collisions or radial convection of the mode due to coupling to either the compressional or ion-Bernstein wave can explain the observed dissipation.

Filamentation of a converging heavy ion beam

International Nuclear Information System (INIS)

Lee, E.P.; Buchanan, H.L.; Rosenbluth, M.N.

1980-01-01

A major concern in the use of heavy ion beams as igniters in pellet fusion systems is the vulnerability of the beam to the transverse flamentation instability. The undesirable consequence of this mode is the transverse heating of the beam to the extent that convergence on the pellet becomes impossible. This work considers the case of a beam injected into a gas filled reactor vessel, where finite pulse length and propagation distance play an important role in limiting growth. Two geometries are analyzed: a nonconverging case where the radius at injection is nearly equal to the desired radius at the pellet, and a converging case in which the injection radius is large and the beam is pre-focused to converge at the target. It is found that a cold beam will be severely disrupted if the product of the magnetic plasma frequency and the propagation distance is much larger than unity

Ion separation from dilute electrolyte solutions by nanofiltration

International Nuclear Information System (INIS)

Garcia, Corazon M.

2000-03-01

Nanofiltration (NF) is a pressure-driven process which is considered potential for the separation of ionic species selectively from solutions containing mixture of electrolyte solutes. The lower operating pressure requirement of NF than reverse osmosis (RO) makes the earlier potentially economical. In the separation of ions, many authors believed that there are membranes with characteristic fixed surface charge and that the mechanism of separation of ions is by the differences in valences of the ions. In this study, experiments involving dilute single-solute and multiple-solute electrolyte solutions were performed using three different NF membranes. Permeate fluxes and ion rejections of the different species of ions in samples of permeate solutions were measured at varied conditions. The mechanism of separation in NF was determined based on the analysis of the trends and behavior of ion rejection relative to the solution temperature, pressure, type of solute, feed concentration and feed solution pH. The results of the experiments show that there is no evidence of the presence of fixed surface charge on the NF membranes. Ion separation was made possible by the combination of sieve effect and ion-hydration effect. Ions having higher hydration numbers showed higher ion rejection than those having lower hydration numbers. A method to determine the effective membrane pore size of NF membranes using hydrodynamic model was proposed. The proposed method is based on the assumptions that the membrane is neutral and that the separation is based on sieving effect. (Author)

Ion sensing method

Science.gov (United States)

Smith, Richard Harding; Martin, Glenn Brian

2004-05-18

The present invention allows the determination of trace levels of ionic substances in a sample solution (ions, metal ions, and other electrically charged molecules) by coupling a separation method, such as liquid chromatography, with ion selective electrodes (ISE) prepared so as to allow detection at activities below 10.sup.-6 M. The separation method distributes constituent molecules into fractions due to unique chemical and physical properties, such as charge, hydrophobicity, specific binding interactions, or movement in an electrical field. The separated fractions are detected by means of the ISE(s). These ISEs can be used singly or in an array. Accordingly, modifications in the ISEs are used to permit detection of low activities, specifically, below 10.sup.-6 M, by using low activities of the primary analyte (the molecular species which is specifically detected) in the inner filling solution of the ISE. Arrays constructed in various ways allow flow-through sensing for multiple ions.

Status of ion sources at HIMAC

International Nuclear Information System (INIS)

Kitagawa, A.; Fujita, T.; Muramatsu, M.; Sakamoto, Y.; Sakuma, T.; Sasaki, N.; Sasano, T.; Takasugi, W.; Biri, S.; Drentje, A.G.

2012-01-01

The Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS) was designed as a clinical dedicated facility. The carbon ions are utilized for the heavy-ion radiotherapy, so its production is the most important aim for ion sources at HIMAC. However HIMAC has a second essential task to operate as a facility for basic experiments. In that scope it accelerates many ions. In order to serve all HIMAC users at best, three ion sources have been installed. This report summarizes the status of the ion sources to produce carbon ions and to extend the range of ion species. It appears that the improvement of the cooling system gave good stability and reproducibility although the carbon depositions on the surface of all parts is unavoidable. An almost maintenance free ion source for carbon ion radiotherapy has been developed. It also appears that a 2 frequency heating improved the beam intensity under the conditions of enough power and precise frequency tuning for the additional microwave. The paper is followed by the slides of the presentation. (A.C.)

Integral Transport Analysis Results for Ions Flowing Through Neutral Gas

Science.gov (United States)

Emmert, Gilbert; Santarius, John

2017-10-01

Results of a computational model for the flow of energetic ions and neutrals through a background neutral gas will be presented. The method models reactions as creating a new source of ions or neutrals if the energy or charge state of the resulting particle is changed. For a given source boundary condition, the creation and annihilation of the various species is formulated as a 1-D Volterra integral equation that can quickly be solved numerically by finite differences. The present work focuses on multiple-pass, 1-D ion flow through neutral gas and a nearly transparent, concentric anode and cathode pair in spherical, cylindrical, or linear geometry. This has been implemented as a computer code for atomic (3He, 3He +, 3He + +) and molecular (D, D2, D-, D +, D2 +, D3 +) ion and neutral species, and applied to modeling inertial-electrostatic connement (IEC) devices. The code yields detailed energy spectra of the various ions and energetic neutral species. Calculations for several University of Wisconsin IEC and ion implantation devices will be presented. Research supported by US Dept. of Homeland Security Grant 2015-DN-077-ARI095, Dept. of Energy Grant DE-FG02-04ER54745, and the Grainger Foundation.

Molecular carbon nitride ion beams for enhanced corrosion resistance of stainless steel

Science.gov (United States)

Markwitz, A.; Kennedy, J.

2017-10-01

A novel approach is presented for molecular carbon nitride beams to coat stainless surfaces steel using conventional safe feeder gases and electrically conductive sputter targets for surface engineering with ion implantation technology. GNS Science's Penning type ion sources take advantage of the breaking up of ion species in the plasma to assemble novel combinations of ion species. To test this phenomenon for carbon nitride, mixtures of gases and sputter targets were used to probe for CN+ ions for simultaneous implantation into stainless steel. Results from mass analysed ion beams show that CN+ and a variety of other ion species such as CNH+ can be produced successfully. Preliminary measurements show that the corrosion resistance of stainless steel surfaces increased sharply when implanting CN+ at 30 keV compared to reference samples, which is interesting from an application point of view in which improved corrosion resistance, surface engineering and short processing time of stainless steel is required. The results are also interesting for novel research in carbon-based mesoporous materials for energy storage applications and as electrode materials for electrochemical capacitors, because of their high surface area, electrical conductivity, chemical stability and low cost.

Ion beam induces nitridation of silicon

International Nuclear Information System (INIS)

Petravic, M.; Williams, J.S.; Conway, M.

1998-01-01

High dose ion bombardment of silicon with reactive species, such as oxygen and nitrogen, has attracted considerable interest due to possible applications of beam-induced chemical compounds with silicon. For example, high energy oxygen bombardment of Si is now routinely used to form buried oxide layers for device purposes, the so called SIMOX structures. On the other hand, Si nitrides, formed by low energy ( 100 keV) nitrogen beam bombardment of Si, are attractive as oxidation barriers or gate insulators, primarily due to the low diffusivity of many species in Si nitrides. However, little data exists on silicon nitride formation during bombardment and its angle dependence, in particular for N 2 + bombardment in the 10 keV range, which is of interest for analytical techniques such as SIMS. In SIMS, low energy oxygen ions are more commonly used as bombarding species, as oxygen provides stable ion yields and enhances the positive secondary ion yield. Therefore, a large body of data can be found in the literature on oxide formation during low energy oxygen bombardment. Nitrogen bombardment of Si may cause similar effects to oxygen bombardment, as nitrogen and oxygen have similar masses and ranges in Si, show similar sputtering effects and both have the ability to form chemical compounds with Si. In this work we explore this possibility in some detail. We compare oxide and nitride formation during oxygen and nitrogen ion bombardment of Si under similar conditions. Despite the expected similar behaviour, some large differences in compound formation were found. These differences are explained in terms of different atomic diffusivities in oxides and nitrides, film structural differences and thermodynamic properties. (author)

Selection of targets and ion sources for RIB generation at the Holifield Radioactive Ion Beam Facility

International Nuclear Information System (INIS)

Alton, G.D.

1995-01-01

In this report, the authors describe the performance characteristics for a selected number of target ion sources that will be employed for initial use at the Holifield Radioactive Ion Beam Facility (HRIBF) as well as prototype ion sources that show promise for future use for RIB applications. A brief review of present efforts to select target materials and to design composite target matrix/heat-sink systems that simultaneously incorporate the short diffusion lengths, high permeabilities, and controllable temperatures required to effect fast and efficient diffusion release of the short-lived species is also given

Electron spectroscopy with fast heavy ions

International Nuclear Information System (INIS)

Schneider, D.

1983-01-01

Since about 1970 the spectroscopy of Auger-electrons and characteristic x-rays following energetic ion-atom collisions has received a great deal of attention. An increasing number of accelerators, capable of providing a large number of projectile ion species over a wide range of projectile energies, became available for studying ion-atom collision phenomena. Many charged particles from protons up to heavy ions like uranium can be accelerated to energies ranging over six orders of magnitude. This allows us to study systematically a great variety of effects accompanied by dynamic excitation processes of the atomic shells in either the projectile- or target-atoms. The studies yield fundamental information regarding the excitation mechanism (e.g., Coulomb and quasi-molecular excitation) and allow sensitive tests of atomic structure theories. This information in turn is valuable to other fields in physics like plasma-, astro-, or solid-state (surface) physics. It is a characteristic feature of fast heavy-ion accelerators that they can produce highly stripped ion species which have in turn the capability to highly ionize neutral target atoms or molecules in a single collision. The ionization process, mainly due to the strong electrical fields that are involved, allows us to study few-electron atoms with high atomic numbers Z. High resolution spectroscopy performed with these atoms allows a particularly good test of relativistic and QED effects. The probability of producing these few electron systems is determined by the charge state and the velocity of the projectile ions. In this contribution the possibilities of using electron spectroscopy as a tool to investigate fast ion-atom collisions is discussed and demonstrated with a few examples. 30 references

Ion beam enhancement in magnetically insulated ion diodes for high-intensity pulsed ion beam generation in non-relativistic mode

Energy Technology Data Exchange (ETDEWEB)

Zhu, X. P. [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Zhang, Z. C.; Lei, M. K., E-mail: surfeng@dlut.edu.cn [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Pushkarev, A. I. [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Laboratory of Beam and Plasma Technology, High Technologies Physics Institute, Tomsk Polytechnic University, 30, Lenin Ave, 634050 Tomsk (Russian Federation)

2016-01-15

High-intensity pulsed ion beam (HIPIB) with ion current density above Child-Langmuir limit is achieved by extracting ion beam from anode plasma of ion diodes with suppressing electron flow under magnetic field insulation. It was theoretically estimated that with increasing the magnetic field, a maximal value of ion current density may reach nearly 3 times that of Child-Langmuir limit in a non-relativistic mode and close to 6 times in a highly relativistic mode. In this study, the behavior of ion beam enhancement by magnetic insulation is systematically investigated in three types of magnetically insulated ion diodes (MIDs) with passive anode, taking into account the anode plasma generation process on the anode surface. A maximal enhancement factor higher than 6 over the Child-Langmuir limit can be obtained in the non-relativistic mode with accelerating voltage of 200–300 kV. The MIDs differ in two anode plasma formation mechanisms, i.e., surface flashover of a dielectric coating on the anode and explosive emission of electrons from the anode, as well as in two insulation modes of external-magnetic field and self-magnetic field with either non-closed or closed drift of electrons in the anode-cathode (A-K) gap, respectively. Combined with ion current density measurement, energy density characterization is employed to resolve the spatial distribution of energy density before focusing for exploring the ion beam generation process. Consistent results are obtained on three types of MIDs concerning control of neutralizing electron flows for the space charge of ions where the high ion beam enhancement is determined by effective electron neutralization in the A-K gap, while the HIPIB composition of different ion species downstream from the diode may be considerably affected by the ion beam neutralization during propagation.

Scaffold Diversity from N-Acyliminium Ions

DEFF Research Database (Denmark)

Wu, Peng; Nielsen, Thomas E

2017-01-01

N-Acyliminium ions are powerful reactive species for the formation of carbon-carbon and carbon-heteroatom bonds. Strategies relying on intramolecular reactions of N-acyliminium intermediates, also referred to as N-acyliminium ion cyclization reactions, have been employed for the construction...... of structurally diverse scaffolds, ranging from simple bicyclic skeletons to complex polycyclic systems and natural-product-like compounds. This review aims to provide an overview of cyclization reactions of N-acyliminium ions derived from various precursors for the assembly of structurally diverse scaffolds...

A simple alkali-metal and noble gas ion source for SIMS equipments with mass separation of the primary ions

International Nuclear Information System (INIS)

Duesterhoeft, H.; Pippig, R.

1986-01-01

An alkali-metal ion source working without a store of alkali-metals is described. The alkali-metal ions are produced by evaporation of alkali salts and ionization in a low-voltage arc discharge stabilized with a noble gas plasma or in the case of small alkali-metal ion currents on the base of the well known thermic ionization at a hot tungsten wire. The source is very simple in construction and produces a stable ion current of 0.3 μA for more than 100 h. It is possible to change the ion species in a short time. This source is applicable to all SIMS equipments using mass separation for primary ions. (author)

Preparation and cooling of magnesium ion crystals for sympathetic cooling of highly charged ions in a Penning trap

Energy Technology Data Exchange (ETDEWEB)

Murboeck, Tobias

2017-07-01

In this work, laser-cooled ion crystals containing 10{sup 3} to 10{sup 5} singly charged magnesium ions (Mg{sup +}) were prepared in a Penning trap. The properties of the ion crystals and their structure displaying long-range ordering were analyzed by various nondestructive techniques. After creation of the Mg{sup +} ions in the form of ion bunches in an external source, the ions were injected into the Penning trap where their temperature was reduced by eight orders of magnitude within seconds using a combination of buffer gas cooling and Doppler laser cooling. The achieved temperatures in the millikelvin-regime were close to the theoretical Doppler-cooling limit and sufficiently low to induce the transition to a crystal phase exhibiting long-range ordering. The structure of these mesoscopic ion crystals is in agreement with a model describing the crystal as a set of planar shells. This allows for a derivation of properties such as the charge density or the temperature of the observed crystals. For the process of combined buffer-gas and Doppler laser cooling an analytical model has been developed, which explains the time development of the temperature and the fluorescence signal in agreement with the experimental results. The external ion source for the production of singly charged magnesium ions was developed and characterized. A SIMION simulation of the ion creation and extraction process allows to describe the ion bunch structure and to increase the Mg{sup +} number by three orders of magnitude to 10{sup 6} Mg{sup +} ions per bunch. Other ion species with charge states between one (H{sup +}{sub 2}, C{sup +}, N{sup +}{sub 2}, CO{sup +}{sub 2}) and three (Ar{sup 3+}) were injected into the Mg{sup +} crystals. Ion crystals containing more than one ion species were observed with structures in agreement with the theory of centrifugal separation, which indicates sympathetic cooling of the non-fluorescing ion species. This preparation of mixed ion crystals is an

Production of Endohedral Fullerenes by Ion Implantation

Energy Technology Data Exchange (ETDEWEB)

Diener, M.D.; Alford, J. M.; Mirzadeh, S.

2007-05-31

The empty interior cavity of fullerenes has long been touted for containment of radionuclides during in vivo transport, during radioimmunotherapy (RIT) and radioimaging for example. As the chemistry required to open a hole in fullerene is complex and exceedingly unlikely to occur in vivo, and conformational stability of the fullerene cage is absolute, atoms trapped within fullerenes can only be released during extremely energetic events. Encapsulating radionuclides in fullerenes could therefore potentially eliminate undesired toxicity resulting from leakage and catabolism of radionuclides administered with other techniques. At the start of this project however, methods for production of transition metal and p-electron metal endohedral fullerenes were completely unknown, and only one method for production of endohedral radiofullerenes was known. They therefore investigated three different methods for the production of therapeutically useful endohedral metallofullerenes: (1) implantation of ions using the high intensity ion beam at the Oak Ridge National Laboratory (ORNL) Surface Modification and Characterization Research Center (SMAC) and fullerenes as the target; (2) implantation of ions using the recoil energy following alpha decay; and (3) implantation of ions using the recoil energy following neutron capture, using ORNL's High Flux Isotope Reactor (HFIR) as a thermal neutron source. While they were unable to obtain evidence of successful implantation using the ion beam at SMAC, recoil following alpha decay and neutron capture were both found to be economically viable methods for the production of therapeutically useful radiofullerenes. In this report, the procedures for preparing fullerenes containing the isotopes {sup 212}Pb, {sup 212}Bi, {sup 213}Bi, and {sup 177}Lu are described. None of these endohedral fullerenes had ever previously been prepared, and all of these radioisotopes are actively under investigation for RIT. Additionally, the chemistry for

High Energy Ion Acceleration by Extreme Laser Radiation Pressure

Science.gov (United States)

2017-03-14

published in the internationally leading journal Physical Review Letters. We continued to progress this pionee 15.  SUBJECT TERMS ion therapy, heavy ion ...Thomson parabola spectrometer: To separate and provide a measurement of the charge -to-mass ratio and energy spectrum of the different ion species...AFRL-AFOSR-UK-TR-2017-0015 High energy ion acceleration by extreme laser radiation pressure Paul McKenna UNIVERSITY OF STRATHCLYDE VIZ ROYAL COLLEGE

Adsorption of sulfide ions on cerussite surfaces and implications for flotation

International Nuclear Information System (INIS)

Feng, Qicheng; Wen, Shuming; Zhao, Wenjuan; Deng, Jiushuai; Xian, Yongjun

2016-01-01

Highlights: • A new discussion on the lead sulfide species is introduced. • The Na_2S concentration determines cerussite sulfidization. • The activity of lead sulfide species also determines cerussite sulfidization. • Disulfide and polysulfide in lead sulfide species affect its activity. - Abstract: The adsorption of sulfide ions on cerussite surfaces and implications for flotation were studied by X-ray photoelectron spectroscopy (XPS) analysis, micro-flotation tests, and surface adsorption experiments. The XPS analysis results indicated that lead sulfide species formed on the mineral surface after treatment by Na_2S, and the increase in the Na_2S concentration was beneficial for sulfidization. In addition to the content of lead sulfide species, its activity, which was determined by the proportion of sulfide, disulfide and polysulfide, also played an important role in cerussite sulfidization. Micro-flotation tests results demonstrated that insufficient or excessive addition of Na_2S in pulp solutions has detrimental effects on flotation performance, which was attributed to the dosage of Na_2S and the activity of lead sulfide species formed on the mineral surface. Surface adsorption experiments of sulfide ions determined the residual S concentrations in pulp solutions and provided a quantitative illustration for the inhibition of cerussite flotation by excessive sulfide ions. Moreover, it also revealed that sulfide ions in the pulp solution were transformed onto the mineral surface and formed lead sulfide species. These results showed that both of lead sulfide species and its activity acted as an important role in sulfidization flotation process of cerussite.

Adsorption of sulfide ions on cerussite surfaces and implications for flotation

Energy Technology Data Exchange (ETDEWEB)

Feng, Qicheng [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Wen, Shuming, E-mail: fqckmust@126.com [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Zhao, Wenjuan [Kunming Metallurgical Research Institute, Kunming 650031 (China); Deng, Jiushuai; Xian, Yongjun [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093 (China)

2016-01-01

Highlights: • A new discussion on the lead sulfide species is introduced. • The Na{sub 2}S concentration determines cerussite sulfidization. • The activity of lead sulfide species also determines cerussite sulfidization. • Disulfide and polysulfide in lead sulfide species affect its activity. - Abstract: The adsorption of sulfide ions on cerussite surfaces and implications for flotation were studied by X-ray photoelectron spectroscopy (XPS) analysis, micro-flotation tests, and surface adsorption experiments. The XPS analysis results indicated that lead sulfide species formed on the mineral surface after treatment by Na{sub 2}S, and the increase in the Na{sub 2}S concentration was beneficial for sulfidization. In addition to the content of lead sulfide species, its activity, which was determined by the proportion of sulfide, disulfide and polysulfide, also played an important role in cerussite sulfidization. Micro-flotation tests results demonstrated that insufficient or excessive addition of Na{sub 2}S in pulp solutions has detrimental effects on flotation performance, which was attributed to the dosage of Na{sub 2}S and the activity of lead sulfide species formed on the mineral surface. Surface adsorption experiments of sulfide ions determined the residual S concentrations in pulp solutions and provided a quantitative illustration for the inhibition of cerussite flotation by excessive sulfide ions. Moreover, it also revealed that sulfide ions in the pulp solution were transformed onto the mineral surface and formed lead sulfide species. These results showed that both of lead sulfide species and its activity acted as an important role in sulfidization flotation process of cerussite.

Highly Stripped Ion Sources for MeV Ion Implantation

Energy Technology Data Exchange (ETDEWEB)

Hershcovitch, Ady

2009-06-30

manufacturing industry by lowering power consumption by as much as 30 kW per ion implanter. Major problem was meeting commercialization goals did not succeed for the following reasons (which were discovered after R&D completion): record output of high charge state phosphorous would have thermally damage wafers; record high charge state of antimony requires tool (ion implanting machine in ion implantation jargon) modification, which did not make economic sense due to the small number of users. High fraction boron ion was delivered to PVI client Axcelis for retrofit and implantation testing; the source could have reduced beam preinjector power consumption by a factor of 3.5. But, since the source generated some lithium (though in miniscule amounts); last minute decision was made not to employ the source in implanters. An additional noteworthy reason for failure to commercialize is the fact that the ion implantation manufacturing industry had been in a very deep bust cycle. BNL, however, has benefited from advances in high-charge state ion generation, due to the need high charge state ions in some RHIC preinjectors. Since the invention of the transistor, the trend has been to miniaturize semiconductor devices. As semiconductors become smaller (and get miniaturized), ion energy needed for implantation decreases, since shallow implantation is desired. But, due to space charge (intra-ion repulsion) effects, forming and transporting ion beams becomes a rather difficult task. A few small manufacturers of low quality semiconductors use plasma immersion to circumvent the problem. However, in plasma immersion undesired plasma impurity ions are also implanted; hence, the quality of those semiconductors is poor. For high quality miniature semiconductor manufacturing, pure, low energy ion beams are utilized. But, low energy ion implanters are characterized by low current (much lower than desirable) and, therefore, low production rates. Consequently, increasing the current of pure low energy

Modeling of ion beam surface treatment

Energy Technology Data Exchange (ETDEWEB)

Stinnett, R W [Quantum Manufacturing Technologies, Inc., Albuquerque, NM (United States); Maenchen, J E; Renk, T J [Sandia National Laboratories, Albuquerque, NM (United States); Struve, K W [Mission Research Corporation, Albuquerque, NM (United States); Campbell, M M [PASTDCO, Albuquerque, NM (United States)

1997-12-31

The use of intense pulsed ion beams is providing a new capability for surface engineering based on rapid thermal processing of the top few microns of metal, ceramic, and glass surfaces. The Ion Beam Surface Treatment (IBEST) process has been shown to produce enhancements in the hardness, corrosion, wear, and fatigue properties of surfaces by rapid melt and re-solidification. A new code called IBMOD was created, enabling the modeling of intense ion beam deposition and the resulting rapid thermal cycling of surfaces. This code was used to model the effect of treatment of aluminum, iron, and titanium using different ion species and pulse durations. (author). 3 figs., 4 refs.

Calibration and fluctuation of the secular frequency peak amplitude versus initial condition distribution of the ion cloud confined into a three-dimensional quadrupole ion trap using a fourier transform operating mode and a steady ion flow injection mode

International Nuclear Information System (INIS)

Janulyte, A.; Andre, J.; Carette, M.; Mercury, M.; Reynard, C; Zerega, Y.

2009-01-01

A specific Fourier transform operating mode is applied to a 3-dimensional quadrupolar ion trap for mass analysis (Fourier Transform Quadrupolar Ion Trap (FTQIT) Operating Mode or Mass Spectrometer). With this operating mode, an image signal, which is representative of the collective motion of simultaneously confined ions, is made up from a set of recorded time-of-flight histograms. In an ion trap, the secular frequency of ion motion depends on m/Z ratio of the ion. By Fourier transformation of the image signal, one observes the frequency peak of each confined ionic species. When only one ionic species is confined, the peak amplitude is proportional to the maximal amplitude of the image signal. The maximal amplitude of the image signal is expressed according to the operating parameters, the initial conditions of the ions and the number of ions. Simulation tools lead to fluctuation calculation of the maximal amplitude of the image signal. Two origins are explored: (1) the fluctuation of the numbers of ions according to the steady ion flow injection mode (SIFIM) used with this operating mode and (2) the distribution fluctuation of the initial positions and velocities. Initial confinement conditions, obtained with SIFIM injection mode, lead to optimal detection with small fluctuations of the peak amplitude for Fourier transform operating mode applied to an ion trap. (authors)

Damage accumulation in ceramics during ion implantation

International Nuclear Information System (INIS)

McHargue, C.J.; Farlow, G.C.; Begun, G.M.; Williams, J.M.; White, C.W.; Appleton, B.R.; Sklad, P.S.; Angelini, P.

1985-01-01

The damage structures of α-Al 2 O 3 and α-SiC were examined as functions of ion implantation parameters using Rutherford backscattering-channeling, analytical electron microscopy, and Raman spectroscopy. Low temperatures or high fluences of cations favor formation of the amorphous state. At 300 0 K, mass of the bombarding species has only a small effect on residual damage, but certain ion species appear to stabilize the damage microstructure and increase the rate of approach to the amorphous state. The type of chemical bonding present in the host lattice is an important factor in determining the residual damage state

An ion displacement membrame model.

Science.gov (United States)

Hladky, S B; Harris, J D

1967-09-01

The usual assumption in treating the diffusion of ions in an electric field has been that the movement of each ion is independent of the movement of the others. The resulting equation for diffusion by a succession of spontaneous jumps has been well stated by Parlin and Eyring. This paper will consider one simple case in which a different assumption is reasonable. Diffusion of monovalent positive ions is considered as a series of jumps from one fixed negative site to another. The sites are assumed to be full (electrical neutrality). Interaction occurs by the displacement of one ion by another. An ion leaves a site if and only if another ion, not necessarily of the same species, attempts to occupy the same site. Flux ratios and net fluxes are given as functions of the electrical potential, concentration ratios, and number of sites encountered in crossing the membrane. Quantitative comparisons with observations of Hodgkin and Keynes are presented.

Laser-induced fluorescence measurements of argon ion velocities near the sheath boundary of an argon-xenon plasma

International Nuclear Information System (INIS)

Lee, Dongsoo; Severn, Greg; Oksuz, Lutfi; Hershkowitz, Noah

2006-01-01

The Bohm sheath criterion in single- and two-ion species plasma is studied with laser-induced fluorescence using a diode laser. Xenon is added to a low pressure unmagnetized dc hot filament argon discharge confined by surface multidipole magnetic fields. The Ar II transition at 668.614 nm is adopted for optical pumping to detect the fluorescence from the plasma and to measure the argon ion velocity distribution functions with respect to positions relative to a negatively biased boundary plate. The structures of the plasma sheath and presheath are measured by an emissive probe. The ion concentrations of the two-species in the bulk plasma are calculated from ion acoustic wave experiments. Results are compared with previous experiments of Ar-He plasmas in which the argon ions were the heavier ion species. Unlike the previous results, the argon speed is slower than its own Bohm velocity near the sheath-presheath boundary in the Ar-Xe plasma where argon ions are the lighter ion species. We argue that this result is consistent with the behaviour of the helium ion required by the generalized Bohm criterion in the previous experiments with Ar-He plasmas. Further, our results suggest that the measured argon ion speed approaches the ion sound speed of the system

Large acoustic solitons and double layers in plasmas with two positive ion species

International Nuclear Information System (INIS)

Verheest, Frank; Hellberg, Manfred A.; Saini, Nareshpal Singh; Kourakis, Ioannis

2011-01-01

Large nonlinear acoustic waves are discussed in a plasma made up of cold supersonic and adiabatic subsonic positive ions, in the presence of hot isothermal electrons, with the help of Sagdeev pseudopotential theory. In this model, no solitons are found at the acoustic speed, and no compositional parameter ranges exist where solutions of opposite polarities can coexist. All nonlinear modes are thus super-acoustic, but polarity changes are possible. The upper limits on admissible structure velocities come from different physical arguments, in a strict order when the fractional cool ion density is increased: infinite cold ion compression, warm ion sonic point, positive double layers, negative double layers, and finally, positive double layers again. However, not all ranges exist for all mass and temperature ratios. Whereas the cold and warm ion sonic point limitations are always present over a wide range of mass and temperature ratios, and thus positive polarity solutions can easily be obtained, double layers have a more restricted existence range, specially if polarity changes are sought.

Operation of low-energy ion implanters for Si, N, C ion implantation into silicon and glassy carbon

International Nuclear Information System (INIS)

Carder, D.A.; Markwitz, A.

2009-01-01

This report details the operation of the low-energy ion implanters at GNS Science for C, N and Si implantations. Two implanters are presented, from a description of the components through to instructions for operation. Historically the implanters have been identified with the labels 'industrial' and 'experimental'. However, the machines only differ significantly in the species of ions available for implantation and sample temperature during implantation. Both machines have been custom designed for research purposes, with a wide range of ion species available for ion implantation and the ability to implant two ions into the same sample at the same time from two different ion sources. A fast sample transfer capability and homogenous scanning profiles are featured in both cases. Samples up to 13 mm 2 can be implanted, with the ability to implant at temperatures down to liquid nitrogen temperatures. The implanters have been used to implant 28 Si + , 14 N + and 12 C + into silicon and glassy carbon substrates. Rutherford backscattering spectroscopy has been used to analyse the implanted material. From the data a Si 30 C 61 N 9 layer was measured extending from the surface to a depth of about 77 ± 2 nm for (100) silicon implanted with 12 C + and 14 N + at multiple energies. Silicon and nitrogen ion implantation into glassy carbon produced a Si (40.5 %), C (38 %), N (19.5 %) and O (2%) layer centred around a depth of 50 ± 2 nm from the surface. (author). 8 refs., 20 figs

Study of algae's adsorption to uranium ion in water solution

International Nuclear Information System (INIS)

Du Yang; Qiu Yongmei; Dan Guiping; Zhang Dong; Lei Jiarong

2007-01-01

The adsorption efficiencies of the algae to uranium ion were determined at various pH, uranium ion concentrations, adsorption temperatures and the species of coexisted metal ions, and the effect of coexisted metal ion on the adsorption efficiency was researched. The experimental results at pH= 5-8 are as follows. 1) the adsorption capacity is a constant to be about 1.40 μg/g for the Yantai red alga and the sea spinach, and is changeable in the range of 1.03-2.23 μg/g with pH for the sea edible fungus; 2) for the algae the adsorption efficiency and adsorption capacity are related to uranium ion concentration, and the maximum adsorption efficiency and capacity is 95.8% and 65.4 μg/g, respectively; 3) the adsorption process for 24 h is not dependent on the temperature; 4) the effect of the species of coexisted metal ions on the adsorption capacity of uranium ion is various with the time during adsorption process. (authors)

Undesired small RNAs originate from an artificial microRNA precursor in transgenic petunia (Petunia hybrida.

Directory of Open Access Journals (Sweden)

Yulong Guo

Full Text Available Although artificial microRNA (amiRNA technology has been used frequently in gene silencing in plants, little research has been devoted to investigating the accuracy of amiRNA precursor processing. In this work, amiRNAchs1 (amiRchs1, based on the Arabidopsis miR319a precursor, was expressed in order to suppress the expression of CHS genes in petunia. The transgenic plants showed the CHS gene-silencing phenotype. A modified 5' RACE technique was used to map small-RNA-directed cleavage sites and to detect processing intermediates of the amiRchs1 precursor. The results showed that the target CHS mRNAs were cut at the expected sites and that the amiRchs1 precursor was processed from loop to base. The accumulation of small RNAs in amiRchs1 transgenic petunia petals was analyzed using the deep-sequencing technique. The results showed that, alongside the accumulation of the desired artificial microRNAs, additional small RNAs that originated from other regions of the amiRNA precursor were also accumulated at high frequency. Some of these had previously been found to be accumulated at low frequency in the products of ath-miR319a precursor processing and some of them were accompanied by 3'-tailing variant. Potential targets of the undesired small RNAs were discovered in petunia and other Solanaceae plants. The findings draw attention to the potential occurrence of undesired target silencing induced by such additional small RNAs when amiRNA technology is used. No appreciable production of secondary small RNAs occurred, despite the fact that amiRchs1 was designed to have perfect complementarity to its CHS-J target. This confirmed that perfect pairing between an amiRNA and its targets is not the trigger for secondary small RNA production. In conjunction with the observation that amiRNAs with perfect complementarity to their target genes show high efficiency and specificity in gene silencing, this finding has an important bearing on future applications of ami

Undesired small RNAs originate from an artificial microRNA precursor in transgenic petunia (Petunia hybrida).

Science.gov (United States)

Guo, Yulong; Han, Yao; Ma, Jing; Wang, Huiping; Sang, Xianchun; Li, Mingyang

2014-01-01

Although artificial microRNA (amiRNA) technology has been used frequently in gene silencing in plants, little research has been devoted to investigating the accuracy of amiRNA precursor processing. In this work, amiRNAchs1 (amiRchs1), based on the Arabidopsis miR319a precursor, was expressed in order to suppress the expression of CHS genes in petunia. The transgenic plants showed the CHS gene-silencing phenotype. A modified 5' RACE technique was used to map small-RNA-directed cleavage sites and to detect processing intermediates of the amiRchs1 precursor. The results showed that the target CHS mRNAs were cut at the expected sites and that the amiRchs1 precursor was processed from loop to base. The accumulation of small RNAs in amiRchs1 transgenic petunia petals was analyzed using the deep-sequencing technique. The results showed that, alongside the accumulation of the desired artificial microRNAs, additional small RNAs that originated from other regions of the amiRNA precursor were also accumulated at high frequency. Some of these had previously been found to be accumulated at low frequency in the products of ath-miR319a precursor processing and some of them were accompanied by 3'-tailing variant. Potential targets of the undesired small RNAs were discovered in petunia and other Solanaceae plants. The findings draw attention to the potential occurrence of undesired target silencing induced by such additional small RNAs when amiRNA technology is used. No appreciable production of secondary small RNAs occurred, despite the fact that amiRchs1 was designed to have perfect complementarity to its CHS-J target. This confirmed that perfect pairing between an amiRNA and its targets is not the trigger for secondary small RNA production. In conjunction with the observation that amiRNAs with perfect complementarity to their target genes show high efficiency and specificity in gene silencing, this finding has an important bearing on future applications of amiRNAs in gene

Distribution of positive ion species above a diffuse midnight aurora

International Nuclear Information System (INIS)

Moore, T.E.

1978-01-01

The origin of the hot plasma in the Earth's magnetosphere is still open to investigation. Mass composition is an indicator of source region, while the distribution functions bear the signatures of transport and energization processes. Only ions identified as H + and He ++ were detected, and the He ++ was statistically marginal. Coincident magnetic storms are likely to play a crucial role in populating the magnetosphere with energized ionospheric ions. The measured proton distribution was nearly isotropic over downcoming pitch angles at all energies and showed a depleted atmospheric source cone. The high-altitude proton energy distribution had a best fit temperature of 4.5 keV and a number density of 0.17 cm- 3 , corresponding to a peak intensity just over 10 5 cm -2 s -1 sr -1 keV -1 . Altitudinal variations are consistent with the theory of charge exchange of a time-steady incident proton population. Simultaneous electron measurements can be interpreted in terms of an incident electron distribution that is also thermal wih a similar number density but a temperature of 2.5 keV. Taken together, the ion and electron data are consistent with the model of diffuse auroras in which plasma convecting in from the magnetospheric tail precipitates due to strong pitch angle diffusion on auroral field lines linking the near Earth plasma sheet

Ion implantation and ion assisted coatings for wear resistance in metals

International Nuclear Information System (INIS)

Dearnaley, G.

1986-01-01

The implantation of electrically accelerated ions of chosen elements into the surface of material provides a method for improving surface properties such as wear resistance. High concentrations of nitrogen implanted into metals create obstacles to dislocation movement, and certain combinations of metallic and non-metallic species will also strengthen the surface. The process is best applied to situations involving mild abrasive wear and operating temperatures that are not too high. Some dramatic increases in life have been reported under such favourable conditions. A more recent development has been the combination of a thin coating with reactive ion bombardment designed to enhance adhesion by ion mixing at the interface and so provide hardness by the formation of finely dispersed nitrides, including cubic boron nitride. These coatings often possess vivid and decorative colours as an added benefit. Developments in the equipment for industrial ion implantation now offer more attractive costs per unit area and a potentially greater throughput of work. A versatile group of related hard vacuum treatments is now emerging, involving the use of intense beams of nitrogen ions for the purpose of tailoring metal surfaces to resist wear. (author)

Development of Functional Surfaces on High-Density Polyethylene (HDPE) via Gas-Assisted Etching (GAE) Using Focused Ion Beams.

Science.gov (United States)

Sezen, Meltem; Bakan, Feray

2015-12-01

Irradiation damage, caused by the use of beams in electron and ion microscopes, leads to undesired physical/chemical material property changes or uncontrollable modification of structures. Particularly, soft matter such as polymers or biological materials is highly susceptible and very much prone to react on electron/ion beam irradiation. Nevertheless, it is possible to turn degradation-dependent physical/chemical changes from negative to positive use when materials are intentionally exposed to beams. Especially, controllable surface modification allows tuning of surface properties for targeted purposes and thus provides the use of ultimate materials and their systems at the micro/nanoscale for creating functional surfaces. In this work, XeF2 and I2 gases were used in the focused ion beam scanning electron microscope instrument in combination with gallium ion etching of high-density polyethylene surfaces with different beam currents and accordingly different gas exposure times resulting at the same ion dose to optimize and develop new polymer surface properties and to create functional polymer surfaces. Alterations in the surface morphologies and surface chemistry due to gas-assisted etching-based nanostructuring with various processing parameters were tracked using high-resolution SEM imaging, complementary energy-dispersive spectroscopic analyses, and atomic force microscopic investigations.

Relationships between nitric oxide, nitroxyl ion, nitrosonium cation and peroxynitrite.

Science.gov (United States)

Hughes, M N

1999-05-05

This review is concerned mainly with the three redox-related, but chemically distinct, species NO-, NO. and NO+, with greatest emphasis being placed on the chemistry and biology of the nitroxyl ion. Biochemical routes for the formation of nitroxyl ion and methods for showing the intermediacy of this species are discussed, together with chemical methods for generating nitroxyl ion in solution. Reactions of nitroxyl ion with NO., thiols, iron centres in haem and with dioxygen are reviewed The significance of the reaction between NO- and dioxygen as a source of peroxynitrite is assessed, and attention drawn to the possible significance of the spin state of the nitroxyl ion in this context. The biological significance of nitrosation and the importance of S-nitrosothiols and certain metal nitrosyl complexes as carriers of NO+ at physiological pH is stressed. Some features in the chemistry of peroxynitrite are noted.

Nanomaterials-Enhanced Electrically Switched Ion Exchange Process for Water Treatment

International Nuclear Information System (INIS)

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

High current ion sources

International Nuclear Information System (INIS)

Brown, I.G.

1989-06-01

The concept of high current ion source is both relative and evolutionary. Within the domain of one particular kind of ion source technology a current of microamperers might be 'high', while in another area a current of 10 Amperes could 'low'. Even within the domain of a single ion source type, what is considered high current performance today is routinely eclipsed by better performance and higher current output within a short period of time. Within their fields of application, there is a large number of kinds of ion sources that can justifiably be called high current. Thus, as a very limited example only, PIGs, Freemen sources, ECR sources, duoplasmatrons, field emission sources, and a great many more all have their high current variants. High current ion beams of gaseous and metallic species can be generated in a number of different ways. Ion sources of the kind developed at various laboratories around the world for the production of intense neutral beams for controlled fusion experiments are used to form large area proton deuteron beams of may tens of Amperes, and this technology can be used for other applications also. There has been significant progress in recent years in the use of microwave ion sources for high current ion beam generation, and this method is likely to find wide application in various different field application. Finally, high current beams of metal ions can be produced using metal vapor vacuum arc ion source technology. After a brief consideration of high current ion source design concepts, these three particular methods are reviewed in this paper

Plasma-laser ion discrimination by TOF technique applied to coupled SiC detectors.

Science.gov (United States)

Cavallaro, Salvatore

2018-01-01

The rate estimation of nuclear reactions induced in high intensity laser-target interaction (≥1016 W/cm2), is strongly depending on the neutron detection efficiency and ion charge discrimination, according to particles involved in exit open-channels. Ion discrimination is basically performed by means of analysis of pits observed on track detector, which is critically dependent on calibration and/or fast TOF devices based on SiC and diamond detectors. Last setup is used to determine the ion energy and to obtain a rough estimation of yields. However, for each TOF interval, the dependence of yield from the energy deposited in the detector sensitive region, introduces a distortion in the ion spectra. Moreover, if two ion species are present in the same spectrum, the discrimination of their contribution is not attainable. In this paper a new method is described which allows to discriminate the contribution of two ion species in the wide energy range of nuclear reactions induced in laser-target interactions. The method is based on charge response of two TOF-SiC detectors, of suitable thicknesses, placed in adjacent positions. In presence of two ion species, the response of the detectors, associated with different energy losses, can determine the ion specific contribution to each TOF interval.

Metal Ion Controlled Polymorphism of a Peptide

DEFF Research Database (Denmark)

Hemmingsen, Lars Bo Stegeager; Jancso, Attila; Szunyogh, Daniel

2011-01-01

ions on fully or partially unstructured proteins, or the effect of metal ions on protein aggregation. Metal ions may be employed to fold (or misfold) individual peptides in a controlled manner depending on the potential metal ion coordinating amino acid side chains (Cys, His, Asp, Glu......In this work a metal ion binding model dodecapeptide was investigated in terms of its capacity to adopt different structures depending on the metal ion to peptide stoichiometry. The dodecapeptide is much simpler than real proteins, yet displays sufficient complexity to model the effect of metal......, …) in the peptide, and the ligand and structural preferences of the metal ion (in our studies Zn2+, Cd2+, Hg2+, Cu+/2+). Simultaneously, new species such as metal ion bridged ternary complexes or even oligomers may be formed. In recent previous studies we have observed similar polymorphism of zinc finger model...

Redox Species-Based Electrolytes for Advanced Rechargeable Lithium Ion Batteries

KAUST Repository

Ming, Jun; Li, Mengliu; Kumar, Pushpendra; Lu, Ang-Yu; Wahyudi, Wandi; Li, Lain-Jong

2016-01-01

Seeking high-capacity cathodes has become an intensive effort in lithium ion battery research; however, the low energy density still remains a major issue for sustainable handheld devices and vehicles. Herein, we present a new strategy

Current generation by minority-species heating

International Nuclear Information System (INIS)

Fisch, N.J.

1981-01-01

It is proposed that electric currents be generated from the preferential heating of ions travelling in one direction but with no net momentum injected into the system. This can be accomplished with, for example, travelling waves in a two-ion-species plasma. The current can be generated efficiently enough for the scheme to be of interest in maintaining steady-state toroidal currents in a reactor. (author)

Current generation by minority species heating

International Nuclear Information System (INIS)

Fisch, N.J.

1980-07-01

It is proposed that electric currents be generated from the preferential heating of ions traveling in one direction but with no net momentum injected into the system. This can be accomplished with, for example, traveling waves in a two-ion-species plasma. The current can be generated efficiently enough for the scheme to be of interest in maintaining steady-state toroidal currents in a reactor

Laser-ablation-based ion source characterization and manipulation for laser-driven ion acceleration

Science.gov (United States)

Sommer, P.; Metzkes-Ng, J.; Brack, F.-E.; Cowan, T. E.; Kraft, S. D.; Obst, L.; Rehwald, M.; Schlenvoigt, H.-P.; Schramm, U.; Zeil, K.

2018-05-01

For laser-driven ion acceleration from thin foils (∼10 μm–100 nm) in the target normal sheath acceleration regime, the hydro-carbon contaminant layer at the target surface generally serves as the ion source and hence determines the accelerated ion species, i.e. mainly protons, carbon and oxygen ions. The specific characteristics of the source layer—thickness and relevant lateral extent—as well as its manipulation have both been investigated since the first experiments on laser-driven ion acceleration using a variety of techniques from direct source imaging to knife-edge or mesh imaging. In this publication, we present an experimental study in which laser ablation in two fluence regimes (low: F ∼ 0.6 J cm‑2, high: F ∼ 4 J cm‑2) was applied to characterize and manipulate the hydro-carbon source layer. The high-fluence ablation in combination with a timed laser pulse for particle acceleration allowed for an estimation of the relevant source layer thickness for proton acceleration. Moreover, from these data and independently from the low-fluence regime, the lateral extent of the ion source layer became accessible.

Analysis of particle species evolution in neutral beam injection lines

International Nuclear Information System (INIS)

Kim, J.; Haselton, H.H.

1978-07-01

Analytic solutions to the rate equations describing the species evolution of a multispecies positive ion beam of hydrogen due to charge exchange and molecular dissociation are derived as a function of the background gas (H 2 ) line density in the neutralizing gas cell and in the drift tube. Using the solutions, calculations are presented for the relative abundance of each species as a function of the gas cell thickness, the reionization loss rates in the drift tube, and the neutral beam power as a function of the beam energy and the species composition of the original ion beam

Ion bombardment techniques - recent developments in SIMS

International Nuclear Information System (INIS)

Konarski, P.; Miśnik, M.

2013-01-01

We present a short review of cluster ion bombardment technique recently applied in SIMS. Many advantages of using cluster ion beams are specified over monoatomic ion species. Cluster ions open really new perspectives especially in organic based structures analysis. Nevertheless cluster ions are not the perfect solution and still new ideas of ion erosion in SIMS are needed. Another issue discussed is 'storing matter' technique applied for quantitative analysis in SIMS. Simple idea of sputter deposition of eroded material onto rotating substrate and then analysing the stored material allows to avoid strong matrix effects in SIMS. Presented are the results performed in Tele and Radio Research Institute, Warszawa, Poland. These are the first results of ‘storing matter’ technique performed in one analytical chamber of SIMS instrument. (authors)

Ion irradiation of CH4-containing icy mixtures

International Nuclear Information System (INIS)

Baratta, G.A.; Domingo, M.; Ferini, G.; Leto, G.; Palumbo, M.E.; Satorre, M.A.; Strazzulla, G.

2003-01-01

We have studied by infrared absorption spectroscopy the effects of ion irradiation with 60 keV Ar 2+ ions on pure methane (CH 4 ) ice at 12 K and mixtures with water (H 2 O) and nitrogen (N 2 ). Ion irradiation, among other effects, causes the rupture of original molecular bonds and the formation of molecular species not present in the initial ice. Here we present the experimental results and discuss their astrophysical relevance

High charge state metal ion production in vacuum arc ion sources

International Nuclear Information System (INIS)

Brown, I.G.; Anders, A.; Anders, S.

1994-01-01

The vacuum arc is a rich source of highly ionized metal plasma that can be used to make a high current metal ion source. Vacuum arc ion sources have been developed for a range of applications including ion implantation for materials surface modification, particle accelerator injection for fundamental nuclear physics research, and other fundamental and applied purposes. Typically the source is repetitively pulsed with pulse length of order a millisecond and duty cycle or order 1% and operation of a dc embodiment has been demonstrated also. Beams have been produced from over 50 of the solid metals of the periodic table, with mean ion energy up to several hundred keV and with peak (pulsed) beam current up to several amperes. The ion charge state distribution has been extensively studied. Ion spectra have been measured for a wide range of metallic cathode materials, including Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm, Yb, Hf, Ta, W, Ir, Pt, Au, Pb, Bi, Th and U, as well as compound and alloy cathode materials such as TiC, SiC, UC, PbS, brass, and stainless steel. The ions generated are in general multiply-stripped with a mean charge state of from 1 to 3, depending on the particular metal species, and the charge state distribution can have components from Q = 1+ to 6+. Here the authors review the characteristics of vacuum arc ion sources from the perspective of their high charge state metal ion production

SUERC AMS ion detection

International Nuclear Information System (INIS)

Maden, C.; Anastasi, P.A.F.; Dougans, A.; Freeman, S.P.H.T.; Kitchen, R.; Klody, G.; Schnabel, C.; Sundquist, M.; Vanner, K.; Xu, S.

2007-01-01

In a short time Be, C, Al, Cl, Ca and I accelerator mass spectrometry (AMS) have been established on the National Electrostatics Corporation (NEC) 5 MV pelletron system at the Scottish Universities Environmental Research Centre (SUERC). While summarising the present performance of the system, this report will focus on the details of ion detection, which sample materials are used and the analytical procedures employed for each individual species during routine analysis. All rare isotope detection is with a single flexible detector and ion event analysis system, but switching of analysed species typically requires a detector reconfiguration. Configurations for routine 10 Be, 14 C, 26 Al, 36 Cl, 41 Ca and 129 I detection have been established and will be presented here. Notably, there has proven to be sufficient suppression of the isobaric interferences of 36 Cl and 41 Ca in the 5+ charge state using an argon gas stripper at a terminal voltage of 5.0 MV to allow for routine analysis of these isotopes

Metal ion separations with proton-ionizable Lariat Ethers and their polymers

International Nuclear Information System (INIS)

Bartsch, R.A.

1993-01-01

The preparation of novel and specific organic complexing agents may lead to the development of new separation systems for aqueous metal ions. Thus the introduction of highly lipophilic oximes led to the current utilization of these compounds as commercial extractants for the hydrometallurgy of nonferrous metals. Crown ethers (macrocyclic polyethers) have been employed in the laboratory-scale solvent extraction of alkali-metal, alkaline-earth, and other metal cations into organic phases. Attachment of side arms to crown ethers gives lariat ethers. The presence of one or more potential coordination sites in the side arm of the lariat ether may produce substantial changes in the selectivity and efficiency of metal ion complexation. It has been demonstrated that concomitant transfer of an aqueous phase anion into the organic medium is not required for metal ion extraction. This factor is of immense importance to potential practical applications of these proton-ionizable crown ethers in which the common, hard, aqueous phase anions would be involved. Another advantage of proton-ionizable lariat ethers is the ease with which extracted metal ions may be stripped from the organic phase by shaking with aqueous mineral acid. Thus both metal ion extraction and stripping are facilitated by pendent proton-ionizable groups. Most of the hazardous metal ion species in the Hanford Site tank wastes are members of the alkali-metal, alkaline-earth, lanthanide, and actinide families. These hard metal ion species prefer association with hard donor atoms, such as oxygens. Therefore, crown and lariat ethers are well-suited for complexation with such metal ion species

The application of game theory and cognitive economy to analyze the problem of undesired location

International Nuclear Information System (INIS)

Villani, S.

2008-01-01

The analysts of the processes of public bodies decision - taking have long been discussing on the establishment of proper strategies to manage environmental conflicts - above all the so-called problems of undesired location of public works and facilities - efficiently (i.e. on a short-period basis so as to grant decision and agreement stability) and fairly (the parties' satisfaction is itself a further guarantee of decision and agreement stability). Each strategy, anyway, is still in progress, like a universe to create and explore. Therefore, in this paper, we will focus on the analysis of the problem and provide as well some theoretical proposals to arrange a new interpreting model of public bodies decision-taking processes based on the achievements of two new subject-matters: evolutionary game theory and cognitive economy. Both sciences share their investigation field with law and economic science. [it

Structure of Ion Outflow in the Martian Magnetotail

Science.gov (United States)

McFadden, J. P.; Mitchell, D.; Luhmann, J. G.; Connerney, J. E. P.; Jakosky, B. M.

2017-12-01

The Suprathermal And Thermal Ion Composition (STATIC) sensor on the MAVEN spacecraft provides a detailed look at the structure of ion outflow in the Martian magnetotail including ion composition, energization, and flow. Mars' magnetotail contains a mixture of cold (multi-species ions, tailward-moving cold multi-species ions, suprathermal ions of a few tens of eV, warm (about 100 eV) proton populations, and heavy (primarily O+) pickup ions at energies from 1 to 10 keV which may display several simultaneous peaks in energy flux. The cold tailward-moving ions represent a significant fraction of the Martian ion loss, perhaps comparable to loses from molecular oxygen dissociation. The suprathermal tail that accompanies the cold ions varies greatly and provides clues to ion escape. The warm protons, on first examination, appear to be of sheath origin, displaying a similar energy distribution and accompanied by a tenuous warm population at M/Q=2 (which could be either solar wind alphas or molecular hydrogen ions of ionospheric origin). STATIC produces a weak ghost peak at M/Q=11-12 when observing molecular hydrogen ions, but not alphas, often allowing the instrument to distinguish the source of protons. Measurements show the warm protons are of ionospheric origin in the central tail and transition to sheath plasma in the umbra. Energetic (1-10 keV) pickup oxygen in the magnetotail is produced on the nightside, near the pole where the IMF convection electric field points toward the planet, the same hemisphere where sputtering occurs. When two spectral peaks are observed, these tailward-moving ions differ in direction by relatively small angles (about 20 degrees). These peaks can persist for tens of minutes indicating approximately time-stationary acceleration, and therefore acceleration in potential fields. Magnetotail structure and geometry can be inferred not only from the local magnetic field, but also from the measured electron distributions which indicate source

Ion detectors for isotopic measurements

Energy Technology Data Exchange (ETDEWEB)

McCormick, A.

1978-12-15

Detector development over the past two decades has been such that this is now the least likely part of the mass spectrometry equipment to give rise to the sort of measurement errors to cause concern. It is now possible to choose from a number of different types of device which can provide more or less 100% efficiency in ion beam detection under all conceivable experimental conditions required for isotopic analysis, from measurement of large samples using the traditional Faraday cage to measurement of exceedingly small ion currents by ion counting techniques. There are even methods of distinguishing one type of ionic species from another in the detector, thus improving the accuracy when unwanted isobaric species might otherwise grossly distort the measurement. Notable contributions to detector development for nuclear measurements have been made by Dietz at the Knolls Atomic Power Laboratory, by Barnett at Oak Ridge and by Daly at Atomic Weapons Research Establishment (AWRE), Aldermaston. This paper describes the detection methods which are currently in use at AWRE for isotopic analysis of solid samples for routine applications as well as non-routine applications. Other methods are merely mentioned as a stimulus for discussion.

Assessment of ion-atom collision data for magnetic fusion plasma edge modelling

International Nuclear Information System (INIS)

Phaneuf, R.A.

1990-01-01

Cross-section data for ion-atom collision processes which play important roles in the edge plasma of magnetically-confined fusion devices are surveyed and reviewed. The species considered include H, He, Li, Be, C, O, Ne, Al, Si, Ar, Ti, Cr, Fe, Ni, Cu, Mo, W and their ions. The most important ion-atom collision processes occurring in the edge plasma are charge-exchange reactions. Excitation and ionization processes are also considered. The scope is limited to atomic species and to collision velocities corresponding to plasma ion temperatures in the 2-200 eV range. Sources of evaluated or recommended data are presented where possible, and deficiencies in the data base are indicated. 42 refs., 1 fig., 4 tabs

An examination of medical linear accelerator ion-chamber performance

International Nuclear Information System (INIS)

Karolis, C.; Lee, C.; Rinks, A.

1996-01-01

Full text: The company ( Radiation Oncology Physics and Engineering Services Pty Ltd) provides medical physics services to four radiotherapy centres in NSW with a total of 6 high energy medical linear accelerators manufactured by three different companies. As part of the services, the stability of the accelerator ion chamber system is regularly examined for constancy and periodically for absolute calibration. Each accelerator ion chamber has exhibited undesirable behaviour from time to time, sometimes leading to its replacement. This presentation describes the performance of the ion chambers for some of the linacs over a period of 12-18 months and the steps taken by the manufacturer to address the problems encountered. As part of our commissioning procedure of new linacs, an absolute calibration of the accelerator output (photon and electron beams) is repeated several times over the period following examination of the physical properties of the radiation beams. These calibrations were undertaken in water using the groups calibrated ion chamber/electrometer system and were accompanied by constancy checks using an acrylic phantom and field instruments. Constancy checks were performed daily for a period of 8 weeks during the initial life of the accelerator and thereafter weekly. For one accelerator, the ion chamber was replaced 6 times in the first eighteen months of its life due to severe drifts in output, found to be due to pressure changes in one half of the chamber In another accelerator, erratic swings of 2% were observed for a period of nine months, particularly with the electron beams, before the manufacturer offered to change the chamber with another constructed from different materials. In yet another accelerator the ion chamber has shown consistent erratic behaviour, but this has not been addressed by the manufacturer. In another popular accelerator, the dosimetry was found to be very stable until some changes in the tuning were introduced resulting in small

Molecular Dynamics Simulations of Collisional Cooling and Ordering of Multiply Charged Ions in a Penning Trap

International Nuclear Information System (INIS)

Holder, J.P.; Church, D.A.; Gruber, L.; DeWitt, H.E.; Beck, B.R.; Schneider, D.

2000-01-01

Molecular dynamics simulations are used to help design new experiments by modeling the cooling of small numbers of trapped multiply charged ions by Coulomb interactions with laser-cooled Be + ions. A Verlet algorithm is used to integrate the equations of motion of two species of point ions interacting in an ideal Penning trap. We use a time step short enough to follow the cyclotron motion of the ions. Axial and radial temperatures for each species are saved periodically. Direct heating and cooling of each species in the simulation can be performed by periodically rescaling velocities. Of interest are Fe 11+ due to a EUV-optical double resonance for imaging and manipulating the ions, and Ca 14+ since a ground state fine structure transition has a convenient wavelength in the tunable laser range

Quantum ion-acoustic solitary waves in weak relativistic plasma

Indian Academy of Sciences (India)

Abstract. Small amplitude quantum ion-acoustic solitary waves are studied in an unmagnetized two- species relativistic quantum plasma system, comprised of electrons and ions. The one-dimensional quantum hydrodynamic model (QHD) is used to obtain a deformed Korteweg–de Vries (dKdV) equation by reductive ...

Influence of Membrane Equivalent Weight and Reinforcement on Ionic Species Crossover in All-Vanadium Redox Flow Batteries.

Science.gov (United States)

Ashraf Gandomi, Yasser; Aaron, Doug S; Mench, Matthew M

2017-06-06

One of the major sources of lost capacity in all-vanadium redox flow batteries (VRFBs) is the undesired transport (usually called crossover) of water and vanadium ions through the ion-exchange membrane. In this work, an experimental assessment of the impact of ion-exchange membrane properties on vanadium ion crossover and capacity decay of VRFBs has been performed. Two types of cationic membranes (non-reinforced and reinforced) with three equivalent weights of 800, 950 and 1100 g·mol -1 were investigated via a series of in situ performance and capacity decay tests along with ex situ vanadium crossover measurement and membrane characterization. For non-reinforced membranes, increasing the equivalent weight (EW) from 950 to 1100 g·mol -1 decreases the V(IV) permeability by ~30%, but increases the area-specific resistance (ASR) by ~16%. This increase in ASR and decrease in V(IV) permeability was accompanied by increased through-plane membrane swelling. Comparing the non-reinforced with reinforced membranes, membrane reinforcement increases ASR, but V(IV) permeability decreases. It was also shown that there exists a monotonic correlation between the discharge capacity decay over long-term cycling and V(IV) permeability values. Thus, V(IV) permeability is considered a representative diagnostic for assessing the overall performance of a particular ion-exchange membrane with respect to capacity fade in a VRFB.

Electron and ion currents relevant to accurate current integration in MeV ion backscattering spectrometry

International Nuclear Information System (INIS)

Matteson, S.; Nicolet, M.A.

1979-01-01

The magnitude and characteristics of the currents which flow in the target and the chamber of an MeV ion backscattering spectrometer are examined. Measured energy distributions and the magnitude of high-energy secondary electron currents are reported. An empirical universal curve is shown to fit the energy distribution of secondary electrons for several combinations of ion energy, targets and ion species. The magnitude of tertiary electron currents which arise at the vacuum vessel walls is determined for various experimental situations and is shown to be non-negligible in many cases. An experimental arrangement is described which permits charge integrations to 1% arruracy without restricting access to the target as a Faraday cage does. (Auth.)

Double chamber ion source

International Nuclear Information System (INIS)

Uman, M.F.; Winnard, J.R.; Winters, H.F.

1978-01-01

The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

Fabrication of nano porous with heavy ions in plastics for the oil industry; Fabricacion de nano poros con iones pesados en plasticos para la industria petrolera

Energy Technology Data Exchange (ETDEWEB)

Balcazar, M.; Tavera, L.; Mendoza, D.; Mut, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: mbg@nuclear.inin.mx

2003-07-01

The natural gas has undesirable concentrations of other gases like the nitrogen that reduces the heat capacity of the gas. It is required to develop separation technology to increase the caloric value of the gas. Among the technology in development for the separation of these gases there are the nano membranes; these are polymeric material that when synthesizing them form nano pores that allow the selective separation of the gas. Another form of creating these nano pores with uniform and controlled pore size, is irradiating a polymeric material with heavy ions. The energy loss of the heavy ion produces cylindrical damages around its trajectory in a diameter among 30 x 10{sup -10} m and 100 x 10{sup -10} m. This damage breaks the chains of the polymer making it susceptible to the corrosion of appropriate chemical agents that allow to create a pore of the size of some nanometers in the polymer. The basic mechanisms of the interaction of the ions with the polymer are important for the controlled creation, the observation and analysis of these nano pores. One of the more appropriate techniques for the visualization and analysis of the geometry of the produced damages, it is the scanning electron and of the atomic force microscopies. The present work has as objective to define the basic parameters of the interaction of the ion with the polymer that intervene in the fabrication of this nano pores. The conditions of the chemical corrosion process are presented for the creation of micro pores in two polymers CR39 and Makrofol produced by fission fragments and alpha particles. A characterization of the diameters and of the damages profile is make. The obtained results are related with the mechanisms of loss of energy of the ions in the matter and the particles identification in function of the damage geometry. (Author)

Heavy-ion collimation at the Large Hadron Collider. Simulations and measurements

Energy Technology Data Exchange (ETDEWEB)

Hermes, Pascal Dominik

2016-12-19

The CERN Large Hadron Collider (LHC) stores and collides proton and {sup 208}Pb{sup 82+} beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets can still scatter out of the collimation system. When they irradiate the superconducting LHC magnets, the latter risk to quench (lose their superconducting property). These secondary collimation losses can potentially impose a limitation for the stored heavy-ion beam energy. Therefore, their distribution in the LHC needs to be understood by sophisticated simulations. Such simulation tools must accurately simulate the particle motion of many different nuclides in the magnetic LHC lattice and simulate their interaction with the collimators. Previous simulation tools used simplified models for the simulation of particle-matter interaction and showed discrepancies compared to the measured loss patterns. This thesis describes the development and application of improved heavy-ion collimation simulation tools. Two different approaches are presented to provide these functionalities. In the first presented tool, called STIER, fragmentation at the primary collimator is simulated with the Monte-Carlo event generator FLUKA. The ion fragments scattered out of the primary collimator are subsequently tracked as protons with ion-equivalent rigidities in the existing proton tracking tool SixTrack. This approach was used to prepare the collimator settings for the 2015 LHC heavy-ion run and its predictions allowed reducing undesired losses. More accurate simulation results are obtained with the second presented simulation tool, in which SixTrack is extended to track arbitrary heavy ions. This new

Heavy-ion collimation at the Large Hadron Collider. Simulations and measurements

International Nuclear Information System (INIS)

Hermes, Pascal Dominik

2016-01-01

The CERN Large Hadron Collider (LHC) stores and collides proton and 208 Pb 82+ beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets can still scatter out of the collimation system. When they irradiate the superconducting LHC magnets, the latter risk to quench (lose their superconducting property). These secondary collimation losses can potentially impose a limitation for the stored heavy-ion beam energy. Therefore, their distribution in the LHC needs to be understood by sophisticated simulations. Such simulation tools must accurately simulate the particle motion of many different nuclides in the magnetic LHC lattice and simulate their interaction with the collimators. Previous simulation tools used simplified models for the simulation of particle-matter interaction and showed discrepancies compared to the measured loss patterns. This thesis describes the development and application of improved heavy-ion collimation simulation tools. Two different approaches are presented to provide these functionalities. In the first presented tool, called STIER, fragmentation at the primary collimator is simulated with the Monte-Carlo event generator FLUKA. The ion fragments scattered out of the primary collimator are subsequently tracked as protons with ion-equivalent rigidities in the existing proton tracking tool SixTrack. This approach was used to prepare the collimator settings for the 2015 LHC heavy-ion run and its predictions allowed reducing undesired losses. More accurate simulation results are obtained with the second presented simulation tool, in which SixTrack is extended to track arbitrary heavy ions. This new tracking

MIAMI: Microscope and ion accelerator for materials investigations

International Nuclear Information System (INIS)

Hinks, J. A.; Berg, J. A. van den; Donnelly, S. E.

2011-01-01

A transmission electron microscope (TEM) with in situ ion irradiation has been built at the University of Salford, U.K. The system consists of a Colutron G-2 ion source connected to a JEOL JEM-2000FX TEM via an in-house designed and constructed ion beam transport system. The ion source can deliver ion energies from 0.5 to 10 keV for singly charged ions and can be floated up to 100 kV to allow acceleration to higher energies. Ion species from H to Xe can be produced for the full range of energies allowing the investigation of implantation with light ions such as helium as well as the effects of displacing irradiation with heavy inert or self-ions. The ability to implant light ions at energies low enough such that they come to rest within the thickness of a TEM sample and to also irradiate with heavier species at energies sufficient to cause large numbers of atomic displacements makes this facility ideally suited to the study of materials for use in nuclear environments. TEM allows the internal microstructure of a sample to be imaged at the nanoscale. By irradiating in situ it is possible to observe the dynamic evolution of radiation damage which can occur during irradiation as a result of competing processes within the system being studied. Furthermore, experimental variables such as temperature can be controlled and maintained throughout both irradiation and observation. This combination of capabilities enables an understanding of the underlying atomistic processes to be gained and thus gives invaluable insights into the fundamental physics governing the response of materials to irradiation. Details of the design and specifications of the MIAMI facility are given along with examples of initial experimental results in silicon and silicon carbide.

Shielding data for hadron-therapy ion accelerators: Attenuation of secondary radiation in concrete

CERN Document Server

Agosteo, S; Sagia, E; Silari, M

2014-01-01

The secondary radiation field produced by seven different ion species (from hydrogen to nitrogen), impinging onto thick targets made of either iron or ICRU tissue, was simulated with the FLUKA Monte Carlo code, and transported through thick concrete shields: the ambient dose equivalent was estimated and shielding parameters evaluated. The energy for each ion beam was set in order to reach a maximum penetration in ICRU tissue of 290 mm (equivalent to the therapeutic range of 430 MeV/amu carbon ions). Source terms and attenuation lengths are given as a function of emission angle and ion species, along with fits to the Monte Carlo data, for shallow depth and deep penetration in the shield. Trends of source terms and attenuation lengths as a function of neutron emission angle and ion species impinging on tar- get are discussed. A comparison of double differential distributions of neutrons with results from similar simulation works reported in the literature is also included. The aim of this work is to provide shi...

Characterization of the internal ion environment of biofilms based on charge density and shape of ion.

Science.gov (United States)

Kurniawan, Andi; Tsuchiya, Yuki; Eda, Shima; Morisaki, Hisao

2015-12-01

Biofilm polymers contain both electrically positively and negatively charged sites. These charged sites enable the biofilm to trap and retain ions leading to an important role of biofilm such as nutrient recycling and pollutant purification. Much work has focused on the ion-exchange capacity of biofilms, and they are known to adsorb ions through an exchange mechanism between the ions in solution and the ions adsorbed to the charged sites on the biofilm polymer. However, recent studies suggest that the adsorption/desorption behavior of ions in a biofilm cannot be explained solely by this ion exchange mechanism. To examine the possibility that a substantial amount of ions are held in the interstitial region of the biofilm polymer by an electrostatic interaction, intact biofilms formed in a natural environment were immersed in distilled water and ion desorption was investigated. All of the detected ion species were released from the biofilms over a short period of time, and very few ions were subsequently released over more time, indicating that the interstitial region of biofilm polymers is another ion reserve. The extent of ion retention in the interstitial region of biofilms for each ion can be determined largely by charge density, |Z|/r, where |Z| is the ion valence as absolute value and r is the ion radius. The higher |Z|/r value an ion has, the stronger it is retained in the interstitial region of biofilms. Ion shape is also a key determinant of ion retention. Spherical and non-spherical ions have different correlations between the condensation ratio and |Z|/r. The generality of these findings were assured by various biofilm samples. Thus, the internal regions of biofilms exchange ions dynamically with the outside environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Positive ion mobilities in normal liquid 3He at ultralow temperatures

International Nuclear Information System (INIS)

Alexander, P.W.

1978-11-01

The mobility has been measured of positive ions in liquid 3 he in the range 2.5 mK 3 sub(m)/sup(V) 5 sub(m)/sup(V). The effects of 500 p.p.m. 4 He in the 3 He were investigated. It was found that, at low temperatures, several stable ion species could be produced for 3 He pressures of 23 bar and above and, between 25 mK and 60 mK, time dependent conversion from one species of ion to another was observed at all pressures. The creation mechanism, mobility and stability of multiple positive ions were studied. Possible explanations of the phenomena are discussed. The measured drift field dependence of mobility is used to test the quasiparticle scattering model assumed for the liquid. (U.K.)

Sorption of uranyl ions on hydrous oxides

International Nuclear Information System (INIS)

Gupta, A.R.; Venkataramani, B.

1988-01-01

Sorption of uranyl ions on hydrous titanium oxide (HTiO), magnetite (MAG), and hydrous thorium oxide (HThO) has been studied as a function of pH. Hydrous oxides have been characterized by their pH-titration curves, intrinsic dissociation constants (pK ai * ) and point of zero charge (pH pzc ). The fraction of protonated surface hydroxyl groups as well as the surface pH (pH surf ) as a function of solution pH have been computed. The distribution of various hydrolyzed species of uranyl ions with solution pH have been compared with uranyl sorption isotherm on these oxides. Sorption edge in all the cases occurs when free hydroxyl groups are available on the surface and pH surf is sufficiently high to favor the formation of dimer-like species on the surface. A new model for the sorption process, called surface hydrolysis model, which explains these and other features of uranyl sorption on hydrous oxides has been proposed. The model visualizes the sorption process as linking of uranyl ions with two adjacent free surface hydroxyl groups without deprotonation (provided the surface pH is high for the hydrolysis of uranyl ions) and formation of dimer-like structures on the surface. The new model has been successfully applied to the present and other available data on uranyl ion sorption on hydrous oxides. (author)

Magnetospheric Multiscale (MMS) Observations of Energetic Ion Response to Magnetotail Dipolarization Events

Science.gov (United States)

Cohen, I. J.; Mauk, B.; Anderson, B. J.; Sitnov, M. I.; Motoba, T.; Ohtani, S.; Gkioulidou, M.; Fuselier, S. A.; Giles, B. L.; Strangeway, R. J.; Torbert, R. B.; Burch, J. L.

2017-12-01

Observations from the Energetic Ion Spectrometer (EIS) instruments aboard MMS have shown angular (pitch, elevation, azimuthal) asymmetries of energetic (>10s of keV) ions corresponding to dipolarization events in the near-Earth and distant magnetotail. In particular, EIS distinguishes the species composition of these ions (protons, helium, oxygen) and reveals apparent species-based differences in their response. This study presents analysis of the dynamic injection and mass-dependent response of energetic ions that likely result from the kinetic response of the ions to the time-varying electric and magnetic fields associated with injection process. Analysis is focused on discriminating between truly kinetic responses to the dynamics and the features that arise from large gyro-radii particles in the vicinity of strong spatial gradients. The study will focus on EIS measurements and include supplementary data from the FIELDS, FPI, and HPCA instruments.

Applications of ion scattering in surface analysis

International Nuclear Information System (INIS)

Armour, D.G.

1981-01-01

The study of ion scattering from surfaces has made an increasingly important contribution both to the development of highly surface specific analysis techniques and to the understanding of the atomic collision processes associated with ion bombardment of solid surfaces. From an analysis point of view, by appropriate choice of parameters such as ion energy and species, scattering geometry and target temperature, it is possible to study not only the composition of the surface layer but also the detailed atomic arrangement. The ion scattering technique is thus particularly useful for the study of surface compositional and structural changes caused by adsorption, thermal annealing or ion bombardment treatments of simple or composite materials. Ion bombardment induced desorption, damage or atomic mixing can also be effectively studied using scattering techniques. By reviewing the application of the technique to a variety of these technologically important surface investigations, it is possible to illustrate the way in which ion scattering has developed as the understanding of the underlying physics has improved. (author)

Chemistry of sprite discharges through ion-neutral reactions

Science.gov (United States)

Hiraki, Y.; Kasai, Y.; Fukunishi, H.

2008-07-01

We estimate the concentration changes, caused by streamer discharge in sprites, of ozone and related minor species as odd nitrogen (NOx) and hydrogen (HOx) families in the upper stratosphere and mesosphere. The streamer has an intense electric field and high electron density at its head, where a large number of chemically-radical ions and atoms are produced through electron impact on neutral molecules. After its propagation, densities of minor species can be perturbed through ion-neutral chemical reactions initiated by the relaxation of these radical products. We evaluate the production rates of ions and atoms using an electron kinetics model and by assuming that the electric field and electron density are in the head region. We calculate the density variations mainly for NOx, Ox, and HOx species using a one-dimensional model of the neutral and ion composition of the middle atmosphere, including the effect of the sprite streamer. Results at the nighttime condition show that the densities of NO, O3, H, and OH increase suddenly through reactions triggered by the first atomic nitrogen and oxygen product, and electrons just after streamer initiation. It is shown that NO and NO2 still remain for 1 h by a certain order of increase with their source-sink balance, predominantly around 60 km; for other species, increases in O3, OH, HO2, and H2O2 still remain in the range of 40 70 km. From this affirmative result of long-time behavior previously not presented, we emphasize that sprites would have the power to impact local chemistry at night. We also discuss the consistency with previous theoretical and observational studies, along with future suggestions.

Kinetic Framework for the Magnetosphere-Ionosphere-Plasmasphere-Polar Wind System: Modeling Ion Outflow

Science.gov (United States)

Schunk, R. W.; Barakat, A. R.; Eccles, V.; Karimabadi, H.; Omelchenko, Y.; Khazanov, G. V.; Glocer, A.; Kistler, L. M.

2014-12-01

A Kinetic Framework for the Magnetosphere-Ionosphere-Plasmasphere-Polar Wind System is being developed in order to provide a rigorous approach to modeling the interaction of hot and cold particle interactions. The framework will include ion and electron kinetic species in the ionosphere, plasmasphere and polar wind, and kinetic ion, super-thermal electron and fluid electron species in the magnetosphere. The framework is ideally suited to modeling ion outflow from the ionosphere and plasmasphere, where a wide range for fluid and kinetic processes are important. These include escaping ion interactions with (1) photoelectrons, (2) cusp/auroral waves, double layers, and field-aligned currents, (3) double layers in the polar cap due to the interaction of cold ionospheric and hot magnetospheric electrons, (4) counter-streaming ions, and (5) electromagnetic wave turbulence. The kinetic ion interactions are particularly strong during geomagnetic storms and substorms. The presentation will provide a brief description of the models involved and discuss the effect that kinetic processes have on the ion outflow.

Ions generated from uranyl nitrate solutions by electrospray ionization (ESI) and detected with Fourier transform ion-cyclotron resonance (FT-ICR) mass spectrometry.

Science.gov (United States)

Pasilis, Sofie; Somogyi, Arpád; Herrmann, Kristin; Pemberton, Jeanne E

2006-02-01

Electrospray ionization (ESI) of uranyl nitrate solutions generates a wide variety of positively and negatively charged ions, including complex adducts of uranyl ions with methoxy, hydroxy, and nitrate ligands. In the positive ion mode, ions detected by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry are sensitive to instrumental tuning parameters such as quadrupole operating frequency and trapping time. Positive ions correspond to oligomeric uranyl nitrate species that can be characterized as having a general formula of [(UO(2))(n)(A)(m)(CH(3)OH)(s)](+) or [(UO(2))(n)(O)(A)(m)(CH(3)OH)(s)](+) with n = 1-4, m = 1-7, s = 0 or 1, and A = OH, NO(3), CH(3)O or a combination of these, although the formation of NO(3)-containing species is preferred. In the negative ion mode, complexes of the form [(UO(2))(NO(3))(m)](-) (m = 1-3) are detected, although the formation of the oxo-containing ions [(UO(2))(O)(n)(NO(3))(m)](-) (n = 1-2, m = 1-2) and the hydroxy-containing ions [(UO(2))(OH)(n)(NO(3))(m)](-) (n = 1-2, m = 0-1) are also observed. The extent of coordinative unsaturation of both positive and negative ions can be determined by ligand association/exchange and H/D exchange experiments using D(2)O and CD(3)OD as neutral reaction partners in the gas-phase. Positive ions are of varying stability and reactivity and may fragment extensively upon collision with D(2)O, CD(3)OD and N(2) in sustained off-resonance irradiation/collision-induced dissociation (SORI-CID) experiments. Electron-transfer reactions, presumably occurring during electrospray ionization but also in SORI-CID, can result in reduction of U(VI) to U(V) and perhaps even U(IV).

Very broad beam metal ion source for large area ion implantation application

International Nuclear Information System (INIS)

Brown, I.; Anders, S.; Dickinson, M.R.; MacGill, R.A.; Yao, X.

1993-01-01

The authors have made and operated a very broad beam version of vacuum arc ion source and used it to carry out high energy metal ion implantation of a particularly large substrate. A multiple-cathode vacuum arc plasma source was coupled to a 50 cm diameter beam extractor (multiple aperture, accel-decel configuration) operated at a net extraction voltage of up to 50 kV. The metal ion species chosen were Ni and Ta. The mean ion charge state for Ni and Ta vacuum arc plasmas is 1.8 and 2.9, respectively, and so the mean ion energies were up to about 90 and 145 keV, respectively. The ion source was operated in a repetitively pulsed mode with pulse length 250 μs and repetition rate several pulses per second. The extracted beam had a gaussian profile with FWHM about 35 cm, giving a nominal beam area of about 1,000 cm 2 . The current of Ni or Ta metal ions in the beam was up to several amperes. The targets for the ion implantation were a number of 24-inch long, highly polished Cu rails from an electromagnetic rail gun. The rails were located about 80 cm away from the ion source extractor grids, and were moved across a diameter of the vessel in such a way as to maximize the uniformity of the implant along the rail. The saturation retained dose for Ta was limited to about 4 x 10 16 cm -2 because of the rather severe sputtering, in accordance with the theoretical expectations for these implantation conditions. Here they describe the ion source, the implantation procedure, and the kinds of implants that can be produced in this way

Radioisotope labeling technique for vapor density measurements of volatile inorganic species

International Nuclear Information System (INIS)

Peterson, E.J.; Caird, J.A.; Hessler, J.P.; Hoekstra, H.R.; Williams, C.W.

1979-01-01

A new method for complexed metal ion vapor density measurement involving labeling the metal ions of interest with a radioactive isotope is described. The isotope chosen in the present work is unstable and leads to emission of a characteristic γ ray. Thus the γ-counting rate was related to the number density of complexed metal ions in the vapor phase. This technique is applicable to the study of any volatile inorganic species, but in the present study has been used to measure vapor densities of complex species in the TbCl 3 -AlCl 3 system by using tracer 160 Tb. 4 figures, 2 tables

Structure of very heavy few-electron ions - new results from the heavy ion storage ring, ESR

International Nuclear Information System (INIS)

Mokler, P.H.; Stoehlker, T.; Kozhuharov, C.; Moshammer, R.; Rymuza, P.; Bosch, F.; Kandler, T.

1993-08-01

The heavy ion synchrotron/storage ring facility at GSI, SIS/ESR, provides intense beams of cooled, highly-charged ions up to naked uranium (U 92+ ). By electron capture during ion-atom collisions in the gas target of the ESR or by recombination at ion-electron encounters in the ''electron cooler'' excited states are populated. The detailed structure of very heavy one-, two- and three-electron ions is studied. The different mechanisms leading to the excited states are described, as well as the new experimental tools now available for a detailed spectroscopy of these interesting systems. Special emphasis is given to X-ray transitions to the groundstates in H- and He-like systems. For the heaviest species the groundstate Lambshift can now be probed on an accuracy level of better than 10% using solid-state X-ray detectors. Applying dispersive X-ray analyzing techniques, this accuracy will certainly be improved in future. However, utilizing the dielectronic resonances for a spectroscopy, the structure in Li-like heavy ions can already be probed now on the sub eV level. (orig.)

Fluorescence lifetime measurement of radical ions

International Nuclear Information System (INIS)

Ichinose, Nobuyuki; Kinugasa, Jun-ichiro; Hagiri, Masahide; Nakayama, Toshihiro; Murakami, Hiroshi; Kishimoto, Maki; Daido, Hiroyuki

2004-01-01

One-photonic excitation of a charge transfer complex of hexamethoxybenzene (HMB) and nitrosonium tetrafluoroborate (NO + BF 4 - ) in acetonitrile afforded fluorescences emission from excited radical cation of HMB (HMB + *). Lifetime of the excited radical ion species was measured to be 7 ps by the pump-probe transient absorption technique. The lifetime was much shorter than that of free radical ion (63 ps), indicating the presence of an interaction between HMB + * and NO in the excited complex. (author)

A 2-100 keV, UHV ion impact spectrometer for ion-solid interaction studies

International Nuclear Information System (INIS)

Berg, J.A. Van den; Armour, D.G.; Verheij, L.K.

1978-01-01

A 2 to 100 keV ion accelerator has been constructed as part of an ion impact spectrometer in which a number of analytical techniques have been combined to allow a comprehensive study of the interaction of low- and medium-energy ions with solids to be carried out under carefully controlled conditions. The overall requirements of the ion beam system in terms of ion species, beam purity, uniformity, energy spread and intensity were dictated by the interest in carrying out low-energy ion scattering, Rutherford back-scattering and thermal desorption experiments. The accelerator design utilises the principle of low-energy extraction and mass analysis, and post-acceleration up to the required high energy. The ions are produced in a duoplasmatron ion source and a parallel beam is obtained after mass selection, utilising a quadrupole triplet lens in conjunction with a 60 0 stigmatic focusing magnetic analyser. Proton and rare gas ion beams of 1 to 100 nA are routinely obtained on target. The 54 cm diameter, UHV target chamber is pumped by a 270 1 s -1 turbo-molecular pump in conjunction with an in-line titanium sublimator, and typical base pressures of 1 to 4 x 10 -11 Torr are achieved. The target is supported in a precision, three-axis goniometer and the detection system, at present comprising a 90 mm mean diameter hemispherical energy analyser and channel electron multiplier, is mounted on a two-axis manipulator. Preliminary measurements using the system have employed the low-energy ion scattering technique to study the oxidation of a Ni(110) surface. (author)

Sterile mutant of Verbena hybrida induced by heavy ion beam irradiation and wild species V. peruviana exhibit self-incompatible phenotype

International Nuclear Information System (INIS)

Saito, H.; Hayashi, Y.; Abe, T.; Kanaya, T.; Suzuki, K.

2005-01-01

Full text: Garden verbenas (Verbena hybrida) belonging to the Verbenaceae family are originated from interspecific hybridization among several species, many cultivars frequently produce seeds. Recently, a sterile mutant has been isolated in the verbena cultivar 'Coral Pink' of Temari series (Suntory Flowers Ltd., Tokyo, Japan) by mutation induction using heavy-ion beams at RIKEN Accelarator Research Facility (RARF, Saitama, Japan). We investigated pollen and ovule fertility assessed by acetocarmin staining, seed-set following controlled-pollination tests and behavior of pollen tubes in pistils with the sterile mutant of 'Coral Pink' (SC) and its original fertile one (FC). As the results, although SC has functional male and female gametes, few self-pollinated flowers carry out seed-set, leading to sterile phenotype. Additionally, the sterile mechanism of SC was compared with the wild species V. peruviana (VP) which is one of origin of Temari series and exhibits sterility. Interestingly, similar phenotype was observed in PV. We further investigated, therefore, whether there are differences on self-incompatible reaction between SC and VP. (author)

Sterile mutant of Verbena hybrida induced by heavy ion beam irradiation and wild species V. peruviana exhibit self-incompatible phenotype

Energy Technology Data Exchange (ETDEWEB)

Saito, H; Hayashi, Y; Abe, T [RIKEN, Wako (Japan); Kanaya, T; Suzuki, K [Suntory Flowers Ltd., Higashiomi (Japan)

2005-07-01

Full text: Garden verbenas (Verbena hybrida) belonging to the Verbenaceae family are originated from interspecific hybridization among several species, many cultivars frequently produce seeds. Recently, a sterile mutant has been isolated in the verbena cultivar 'Coral Pink' of Temari series (Suntory Flowers Ltd., Tokyo, Japan) by mutation induction using heavy-ion beams at RIKEN Accelarator Research Facility (RARF, Saitama, Japan). We investigated pollen and ovule fertility assessed by acetocarmin staining, seed-set following controlled-pollination tests and behavior of pollen tubes in pistils with the sterile mutant of 'Coral Pink' (SC) and its original fertile one (FC). As the results, although SC has functional male and female gametes, few self-pollinated flowers carry out seed-set, leading to sterile phenotype. Additionally, the sterile mechanism of SC was compared with the wild species V. peruviana (VP) which is one of origin of Temari series and exhibits sterility. Interestingly, similar phenotype was observed in PV. We further investigated, therefore, whether there are differences on self-incompatible reaction between SC and VP. (author)

Computer simulation of scattered ion and sputtered species effects in ion beam sputter-deposition of high temperature superconducting thin films

International Nuclear Information System (INIS)

Krauss, A.R.; Auciello, O.

1992-01-01

Ion beam sputter-deposition is a technique currently used by many groups to produce single and multicomponent thin films. This technique provides several advantages over other deposition methods, which include the capability for yielding higher film density, accurate stoichiometry control, and smooth surfaces. However, the relatively high kinetic energies associated with ion beam sputtering also lead to difficulties if the process is not properly controlled. Computer simulations have been performed to determine net deposition rates, as well as the secondary erosion, lattice damage, and gas implantation in the films, associated with primary ions scattered from elemental Y, Ba and Cu targets used to produce high temperature superconducting Y-Ba-Cu-O films. The simulations were performed using the TRIM code for different ion masses and kinetic energies, and different deposition geometries. Results are presented for primary beams of Ar + , Kr + and Xe + incident on Ba and Cu targets at 0 degrees and 45 degrees with respect to the surface normal, with the substrate positioned at 0 degrees and 45 degrees. The calculations indicate that the target composition, mass and kinetic energy of the primary beam, angle of incidence on the target, and position and orientation of the substrate affect the film damage and trapped primary beam gas by up to 5 orders of magnitude

Patents on Membranes Based on Non-Fluorinated Polymers for Vanadium Redox Flow Batteries.

Science.gov (United States)

Choi, So-Won; Kim, Tae-Ho; Cha, Sang-Ho

2017-07-10

Vanadium redox flow batteries (VRFBs) have received considerable attention as large-scale electrochemical energy storage systems. In particular, VRFBs offer a higher power and energy density than other RFBs and mitigate undesirable performance fading, such as inevitable ion crossover, because of the unique advantage that only the vanadium ion is employed as the active species in the two electrolytes. The key constituent of VRFBs is a separator to conduct protons and prevent cross-mixing of the positive and negative electrolytes. For this purpose, ion exchange membranes like sulfonated polymer membranes can be used. Although this type of membrane does not have ion exchange groups, it can achieve an ion exchange capacity by the formation of pores. This review highlights the patents on the preparation of non-fluorinated membranes (sulfonated aromatic polymer membranes and porous membranes) as alternatives to high-cost perfluorinated polymers and their VRFB performance. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Kinetic Monte Carlo Study of Ambipolar Lithium Ion and Electron-Polaron Diffusion into Nanostructured TiO2

International Nuclear Information System (INIS)

Yu, Jianguo; Sushko, Maria L.; Kerisit, Sebastien N.; Rosso, Kevin M.; Liu, Jun

2012-01-01

Nanostructured titania (TiO2) polymorphs have proved to be promising electrode materials for next generation lithium-ion batteries. However, there is still a lack of understanding of the fundamental microscopic processes that control charge transport in these materials. Here we present microscopic simulations of the collective dynamics of lithium-ion (Li+) and charge compensating electron polarons (e-) in rutile TiO2 nanoparticles in contact with idealized conductive matrix and electrolyte. Kinetic Monte Carlo simulations are used, parameterized by molecular dynamics-based predictions of activation energy barriers for Li+ and e- diffusion. Simulations reveal the central role of electrostatic coupling between Li+ and e- on their collective drift diffusion at the nanoscale. They also demonstrate that high contact area between conductive matrix and rutile nanoparticles leads to undesirable coupling-induced surface saturation effects during Li+ insertion, which limits the overall capacity and conductivity of the material. These results help provide guidelines for design of nanostructured electrode materials with improved electrochemical performance.

TRANSP modeling of minority ion sawtooth mixing in ICRF + NBI heated discharges in TFTR

International Nuclear Information System (INIS)

Goldfinger, R.C.; Batchelor, D.B.; Murakami, M.; Phillips, C.K.; Budny, R.; Hammett, G.W.; McCune, D.M.; Wilson, J.R.; Zarnstorff, M.C.

1995-01-01

Time independent code analysis indicates that the sawtooth relaxation phenomenon affects RF power deposition profiles through the mixing of fast ions. Predicted central electron heating rates are substantially above experimental values unless sawtooth relaxation is included. The PPPL time dependent transport analysis code, TRANSP, currently has a model to redistribute thermal electron and ion species, energy densities, plasma current density, and fast ions from neutral beam injection at each sawtooth event using the Kadomtsev (3) prescription. Results are presented here in which the set of models is extended to include sawtooth mixing effects on the hot ion population generated from ICRF heating. The ICRF generated hot ion distribution function, line-integral(ν parallel , ν perpendicular ), which is strongly peaked at the center before each sawtooth, is replaced throughout the sawtooth mixing volume by its volume averaged value at each sawtooth. The modified line-integral(ν parallel ,ν perpendicular ) is then used to recalculate the collisional transfer of power from the minority species to the background species. Results demonstrate that neglect of sawtooth mixing of ICRF-induced fast ions leads to prediction of faster central electron reheat rates than are measured experimentally

[Feasibility, in general practice, to give to the patients clear, loyal and appropriate information about the undesirable side effects of the medicines prescribed. EICLAT study].

Science.gov (United States)

Arnould, Pascale; Raineri, François; Hebbrecht, Gilles; Duhot, Didier

2011-12-01

Drug prescription in general practice is present in 78 to 83% of consultations; practitioners must give to their patient clear loyal and appropriate information about the undesirable side effects of the medicines prescribed. The object of the EICLAT study was to give some light on the feasibility to respect this obligation. To that effect the study evaluates, for a normal prescription activity, the average number of potential undesirable side effects (USE) in relation with the number of lines of different medicines prescribed in each doctor's prescription. A total of 8,382 doctor's prescriptions, generating 34,427 lines of prescriptions given by 175 general practitioners, were analysed. Amongst these prescriptions, 11% included only one line, 55% from 2 to 4 lines and 34% 5 lines or more. The average doctor's prescription was of 4 lines of medicines generating 407 potential USE, of which 194 were different (the same undesirable effect may be present twice or more in the same doctor's prescription), and 293 frequent or serious potential USE, of which 166 were different. The patent medicines with a major or important added medical value (AMV), present in 7,840 doctor's prescriptions for a total of 24,127 lines exposed the patient, in the average, to 151 frequent or serious USE different. The patent medicines with an insufficient AMV, present in 2,292 prescriptions for a total of 3,887 lines, exposed the patient to 37 frequent and/or serious potential USE. Supposing that the information provided by the legal authority is sufficiently adequate, precise and exhaustive, the volume of information that must be given to the patient is not compatible with the present conditions of exercise of the profession.

Low charge state heavy ion production with sub-nanosecond laser.

Science.gov (United States)

Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

2016-02-01

We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

Low charge state heavy ion production with sub-nanosecond laser

Energy Technology Data Exchange (ETDEWEB)

Kanesue, T., E-mail: tkanesue@bnl.gov; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Kumaki, M. [Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Ikeda, S. [Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Kanagawa 226-8503 (Japan)

2016-02-15

We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

Evolution of charged species in propane/air flames: mass-spectrometric analysis and modelling

International Nuclear Information System (INIS)

Rodrigues, J M; Agneray, A; Jaffrezic, X; Bellenoue, M; Labuda, S; Leys, C; Chernukho, A P; Migoun, A N; Cenian, A; Savel'ev, A M; Titova, N S; Starik, A M

2007-01-01

Experimental and modelling studies of ion formation during combustion of propane/air mixtures are presented. The positive and negative ions mass/charge spectra in propane/air stoichiometric flame at atmospheric pressure are recorded in the range from 0 to 512 atomic mass units. The C 2 H 3 O + and HCO 2 - ions are found to be the most abundant ionic species in the flame front region. By increasing the distance from the flame front the ion composition changes significantly. In the burnt gas region the H 3 O + , NO + , CO 3 - , HCO 3 - ions are found to be the major charged species. To explain the experimental results the extended kinetic model describing the ion formation in flame and in the extraction system of the mass-spectrometer as well as ion-soot interaction is developed. It is shown that the ionic clusters, which are observed experimentally, form during the adiabatic expansion in the extraction system, and the presence of soot particles may change the total positive and negative ion concentrations in the gas phase

Industrial ion source technology

Science.gov (United States)

Kaufman, H. R.; Robinson, R. S.

1978-01-01

An analytical model was developed to describe the development of a coned surface texture with ion bombardment and simultaneous deposition of an impurity. A mathematical model of sputter deposition rate from a beveled target was developed in conjuction with the texturing models to provide an important input to that model. The establishment of a general procedure that will allow the treatment of manay different sputtering configurations is outlined. Calculation of cross sections for energetic binary collisions was extened to Ar, Kr.. and Xe with total cross sections for viscosity and diffusion calculated for the interaction energy range from leV to 1000eV. Physical sputtering and reactive ion etching experiments provided experimental data on the operating limits of a broad beam ion source using CF4 as a working gas to produce reactive species in a sputtering beam. Magnetic clustering effects are observed when Al is seeded with Fe and sputtered with Ar(?) ions. Silicon was textured at a micron scale by using a substrate temperature of 600 C.

A three-scale model for ionic solute transport in swelling clays incorporating ion-ion correlation effects

Science.gov (United States)

Le, Tien Dung; Moyne, Christian; Murad, Marcio A.

2015-01-01

A new three-scale model is proposed to describe the movement of ionic species of different valences in swelling clays characterized by three separate length scales (nano, micro, and macro) and two levels of porosity (nano- and micropores). At the finest (nano) scale the medium is treated as charged clay particles saturated by aqueous electrolyte solution containing monovalent and divalent ions forming the electrical double layer. A new constitutive law is constructed for the disjoining pressure based on the numerical resolution of non-local problem at the nanoscale which, in contrast to the Poisson-Boltzmann theory for point charge ions, is capable of capturing the short-range interactions between the ions due to their finite size. At the intermediate scale (microscale), the two-phase homogenized particle/electrolyte solution system is represented by swollen clay clusters (or aggregates) with the nanoscale disjoining pressure incorporated in a modified form of Terzaghi's effective principle. At the macroscale, the electro-chemical-mechanical couplings within clay clusters is homogenized with the ion transport in the bulk fluid lying in the micro pores. The resultant macroscopic picture is governed by a three-scale model wherein ion transport takes place in the bulk solution strongly coupled with the mechanics of the clay clusters which play the role of sources/sinks of mass to the bulk fluid associated with ion adsorption/desorption in the electrical double layer at the nanoscale. Within the context of the quasi-steady version of the multiscale model, wherein the electrolyte solution in the nanopores is assumed at instantaneous thermodynamic equilibrium with the bulk fluid in the micropores, we build-up numerically the ion-adsorption isotherms along with the constitutive law of the retardation coefficients of monovalent and divalent ions. In addition, the constitutive law for the macroscopic swelling pressure is reconstructed numerically showing patterns of

Heavy ion acceleration at the AGS

International Nuclear Information System (INIS)

Lee, Y.Y.

1989-01-01

The Brookhaven AGS is alternating gradient synchrotron, 807 meters in circumference, which was originally designed for only protons. Using the 15 MV Brookhaven Tandem Van de Graaff as an injector, the AGS started to accelerate heavy ions of mass lighter than sulfur. Because of the relatively poor vacuum (∼10 -8 Torr), the AGS is not able to accelerate heavier ions which could not be fully stripped of electrons at the Tandem energy. When the AGS Booster, which is under construction, is completed the operation will be extended to all species of heavy ions including gold and uranium. Because ultra-high vacuum (∼10 -11 Torr) is planned, the Booster can accelerate partially stripped elements. The operational experience, the parameters, and scheme of heavy ion acceleration will be presented in detail from injection to extraction, as well as future injection into the new Relativistic Heavy Ion Collider (RHIC). A future plan to improve intensity of the accelerator will also be presented. 5 figs., 4 tabs

Ion induced Auger spectroscopy

International Nuclear Information System (INIS)

Thomas, E.W.; Legg, K.O.; Metz, W.A.

1980-01-01

Auger electron spectra are induced by impact of heavy ions (e.g. Ar + ) on surfaces; it has been suggested that analysis of such spectra would be a useful technique for surface analysis. We have examined the Auger spectra for various projectile-target combinations and present as representative data the spectra for 100 keV Ar + impact on Al, Cr, Mn, Fe and Co. For a projectile incident on a species of higher nuclear charge the spectrum is dominated by Auger lines from the projectile, broadened considerably by the Doppler effect due to the projectile's motion. The spectra are not characteristic of the target and therefore offer no opportunity for surface analysis. For a projectile incident on a target of lower nuclear charge the spectrum is that of the target species but the spectrum is consistent with the source being sputtered excited atoms; the Auger electrons do not come from the surface. We conclude that the ion induced Auger spectra are in general not a convenient method for surface analysis. (orig.)

Initial use of the positive-ion injector of ATLAS

International Nuclear Information System (INIS)

Bollinger, L.M.; Billquist, P.J.; Bogaty, J.M.; Clifft, B.E.; Den Hartog, P.K.; Munson, F.H. Jr.; Pardo, R.C.; Shepard, K.W.; Zinkann, G.P.

1989-01-01

The positive-ion injector of ATLAS consists of an ECR heavy-ion source coupled to a 12-MV superconducting injector linac. The ECR source and a 3-MV version of the partially completed linac have been used to accelerate successfully several species of heavy ions. The operating experience is summarized, with emphasis on the excellent beam quality of beams from the new injector. Two new fast-timing detectors are described. 9 refs., 5 figs., 1 tab

Secondary ion yield changes in Si and GaAs due to topography changes during O+2 or Cs+ ion bombardment

International Nuclear Information System (INIS)

Stevie, F.A.; Kahora, P.M.; Simons, D.S.; Chi, P.

1988-01-01

Changes in secondary ion yields of matrix and dopant species have been correlated with changes in surface topography during O + 2 bombardment of Si and GaAs. In Si, profiles were measured in (100) wafers at 6- and 8-keV impact energy. At 6 keV, a yield increase of about 70% occurred for Si + over a depth range of 2.5 to 3.5 μm, with changes in other species ranging from a decrease of ∼20% for Si + 3 to an increase of more than 25% for O + . The development of a rippled surface topography was observed in scanning electron micrographs over the same depth range. Similar effects occurred over a 3--5 μm depth range for 8-keV ions, and in (111) silicon at a depth of 3 to 4 μm for 6-keV ions. No differences were noted between p- and n-type silicon, or implanted and unimplanted silicon. In GaAs, profiles were measured in (100) wafers at 2.5-, 5.5-, and 8-keV impact energies. At 8 keV, a yield increase of about 70% was found for GaO + in the range 0.6--1.0 μm, with smaller changes for other matrix species. At 5.5 keV, similar effects were observed, but over a depth interval of 0.3 to 0.7 μm. No yield changes were detected at 2.5-keV impact energy. The yield changes at the higher energies were again correlated with the onset of changes in topography. No change in ion yield or surface topography was noted for Cs + bombardment of Si or GaAs. The topography and ion yield changes are affected by the angle of incidence and, for Si, the oxygen coverage. The results show that the practice of normalizing secondary ion mass spectrometry dopant profiles to a matrix signal must be modified for situations where matrix yield changes occur

Lifetime measurements in an electrostatic ion beam trap using image charge monitoring

International Nuclear Information System (INIS)

Rahinov, Igor; Toker, Yoni; Heber, Oded; Rappaport, Michael; Zajfman, Daniel; Strasser, Daniel; Schwalm, Dirk

2012-01-01

A technique for mass-selective lifetime measurements of keV ions in a linear electrostatic ion beam trap is presented. The technique is based on bunching the ions using a weak RF potential and non-destructive ion detection by a pick-up electrode. This method has no mass-limitation, possesses the advantage of inherent mass-selectivity, and offers a possibility of measuring simultaneously the lifetimes of different ion species with no need for prior mass-selection.

Sulfate radical-based degradation of polychlorinated biphenyls: Effects of chloride ion and reaction kinetics

Energy Technology Data Exchange (ETDEWEB)

Fang, Guo-Dong [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Dionysiou, Dionysios D. [Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0071 (United States); Wang, Yu [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Al-Abed, Souhail R. [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States); Zhou, Dong-Mei, E-mail: dmzhou@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

2012-08-15

Highlights: Black-Right-Pointing-Pointer A kinetic model was used to predict the radical species and their distributions. Black-Right-Pointing-Pointer The generated radical species were identified by EPR. Black-Right-Pointing-Pointer The second-order rate constants of sulfate radical with PCBs were determined. - Abstract: Advanced oxidation processes (AOPs) based on sulfate radical (SO{sub 4}{center_dot}{sup -}) have been recently used for soil and groundwater remediation. The presence of chloride ion in natural or wastewater decreases the reactivity of sulfate radical system, but explanations for this behavior were inconsistent, and the mechanisms are poorly understood. Therefore, in this paper we investigated the effect of chloride ion on the degradation of 2,4,4 Prime -CB (PCB28) and biphenyl (BP) by persulfate, based on the produced SO{sub 4}{center_dot}{sup -}. The results showed that the presence of chloride ion greatly inhibited the transformation of PCB28 and BP. Transformation intermediates of BP were monitored, suggesting that the chloride ion can react with SO{sub 4}{center_dot}{sup -} to produce chlorine radical, which reacts with BP to generate chlorinated compounds. To better understand the underlying mechanisms of these processes, a kinetic model was developed for predicting the effect of chloride ion on the types of radical species and their distributions. The results showed that chloride ion could influence the selectivity of radical species and their distribution, and increase the concentration of the sum of radical species. In addition, the second-order rate constants of sulfate radical with PCBs were determined, and quantum-chemical descriptors were introduced to predict the rate constants of other PCBs based on our experimental data.

Statistical characterization of surface defects created by Ar ion bombardment of crystalline silicon

International Nuclear Information System (INIS)

Ghazisaeidi, M.; Freund, J. B.; Johnson, H. T.

2008-01-01

Ion bombardment of crystalline silicon targets induces pattern formation by the creation of mobile surface species that participate in forming nanometer-scale structures. The formation of these mobile species on a Si(001) surface, caused by sub-keV argon ion bombardment, is investigated through molecular dynamics simulation of Stillinger-Weber [Phys. Rev. B 31, 5262 (1985)] silicon. Specific criteria for identifying and classifying these mobile atoms based on their energy and coordination number are developed. The mobile species are categorized based on these criteria and their average concentrations are calculated

Interaction of Hydroxyproline with Bivalent Metal Ions in Chemical ...

African Journals Online (AJOL)

NICO

The stability constants of the ML and ML2 complex species of some metal ions, namely beryllium(II) and cobalt(II), with hydroxyproline were ... metal ions have several significant applications in biological systems.3–20 Beryllium is one ... 1 filter paper for chromatography was used for the purpose of electrophoresis. An Elico ...

Organic positive ions in aircraft gas-turbine engine exhaust

Science.gov (United States)

Sorokin, Andrey; Arnold, Frank

Volatile organic compounds (VOCs) represent a significant fraction of atmospheric aerosol. However the role of organic species emitted by aircraft (as a consequence of the incomplete combustion of fuel in the engine) in nucleation of new volatile particles still remains rather speculative and requires a much more detailed analysis of the underlying mechanisms. Measurements in aircraft exhaust plumes have shown the presence of both different non-methane VOCs (e.g. PartEmis project) and numerous organic cluster ions (MPIK-Heidelberg). However the link between detected organic gas-phase species and measured mass spectrum of cluster ions is uncertain. Unfortunately, up to now there are no models describing the thermodynamics of the formation of primary organic cluster ions in the exhaust of aircraft engines. The aim of this work is to present first results of such a model development. The model includes the block of thermodynamic data based on proton affinities and gas basicities of organic molecules and the block of non-equilibrium kinetics of the cluster ions evolution in the exhaust. The model predicts important features of the measured spectrum of positive ions in the exhaust behind aircraft. It is shown that positive ions emitted by aircraft engines into the atmosphere mostly consist of protonated and hydrated organic cluster ions. The developed model may be explored also in aerosol investigations of the background atmosphere as well as in the analysis of the emission of fine aerosol particles by automobiles.

Chemistry of sprite discharges through ion-neutral reactions

Directory of Open Access Journals (Sweden)

Y. Hiraki

2008-07-01

Full Text Available We estimate the concentration changes, caused by streamer discharge in sprites, of ozone and related minor species as odd nitrogen (NO_x and hydrogen (HO_x families in the upper stratosphere and mesosphere. The streamer has an intense electric field and high electron density at its head, where a large number of chemically-radical ions and atoms are produced through electron impact on neutral molecules. After its propagation, densities of minor species can be perturbed through ion-neutral chemical reactions initiated by the relaxation of these radical products. We evaluate the production rates of ions and atoms using an electron kinetics model and by assuming that the electric field and electron density are in the head region. We calculate the density variations mainly for NO_x, O_x, and HO_x species using a one-dimensional model of the neutral and ion composition of the middle atmosphere, including the effect of the sprite streamer. Results at the nighttime condition show that the densities of NO, O₃, H, and OH increase suddenly through reactions triggered by the first atomic nitrogen and oxygen product, and electrons just after streamer initiation. It is shown that NO and NO₂ still remain for 1 h by a certain order of increase with their source-sink balance, predominantly around 60 km; for other species, increases in O₃, OH, HO₂, and H₂O₂ still remain in the range of 40–70 km. From this affirmative result of long-time behavior previously not presented, we emphasize that sprites would have the power to impact local chemistry at night. We also discuss the consistency with previous theoretical and observational studies, along with future suggestions.

Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries.

Science.gov (United States)

Yabuuchi, Naoaki; Nakayama, Masanobu; Takeuchi, Mitsue; Komaba, Shinichi; Hashimoto, Yu; Mukai, Takahiro; Shiiba, Hiromasa; Sato, Kei; Kobayashi, Yuki; Nakao, Aiko; Yonemura, Masao; Yamanaka, Keisuke; Mitsuhara, Kei; Ohta, Toshiaki

2016-12-23

Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn 4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g -1 based on solid-state redox reaction of oxide ions.

Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries

Science.gov (United States)

Yabuuchi, Naoaki; Nakayama, Masanobu; Takeuchi, Mitsue; Komaba, Shinichi; Hashimoto, Yu; Mukai, Takahiro; Shiiba, Hiromasa; Sato, Kei; Kobayashi, Yuki; Nakao, Aiko; Yonemura, Masao; Yamanaka, Keisuke; Mitsuhara, Kei; Ohta, Toshiaki

2016-01-01

Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g−1 based on solid-state redox reaction of oxide ions. PMID:28008955

Cathodoluminescence and ion beam analysis of ion-implanted combinatorial materials libraries on thermally grown SiO2

International Nuclear Information System (INIS)

Chen, C.-M.; Pan, H.C.; Zhu, D.Z.; Hu, J.; Li, M.Q.

1999-01-01

A method combining ion implantation and physical masking technique has been used to generate material libraries of various ion-implanted samples. Ion species of C, Ga, N, Pb, Sn, Y have been sequentially implanted to an SiO 2 film grown on a silicon wafer through combinatorial masks and consequently a library of 64 (2 6 ) samples is generated by 6 masking combinations. This approach offers rapid synthesis of samples with potential new compounds formed in the matrix, which may have specific luminescent properties. The depth-resolved cathodoluminescence (CL) measurements revealed some specific optical property in the samples correlated with implanted ion distributions. A marker-based technique is developed for the convenient location of sample site in the analysis of Rutherford backscattering spectrometry (RBS) and proton elastic scattering (PES), intended to characterize rapidly the ion implanted film libraries. These measurements demonstrate the power of nondestructively and rapidly characterizing composition and the inhomogeneity of the combinatorial film libraries, which may determine their physical properties

Comprehensive Peptide Ion Structure Studies Using Ion Mobility Techniques: Part 3. Relating Solution-Phase to Gas-Phase Structures.

Science.gov (United States)

Kondalaji, Samaneh Ghassabi; Khakinejad, Mahdiar; Valentine, Stephen J

2018-06-01

Molecular dynamics (MD) simulations have been utilized to study peptide ion conformer establishment during the electrospray process. An explicit water model is used for nanodroplets containing a model peptide and hydronium ions. Simulations are conducted at 300 K for two different peptide ion charge configurations and for droplets containing varying numbers of hydronium ions. For all conditions, modeling has been performed until production of the gas-phase ions and the resultant conformers have been compared to proposed gas-phase structures. The latter species were obtained from previous studies in which in silico candidate structures were filtered according to ion mobility and hydrogen-deuterium exchange (HDX) reactivity matches. Results from the present study present three key findings namely (1) the evidence from ion production modeling supports previous structure refinement studies based on mobility and HDX reactivity matching, (2) the modeling of the electrospray process is significantly improved by utilizing initial droplets existing below but close to the calculated Rayleigh limit, and (3) peptide ions in the nanodroplets sample significantly different conformers than those in the bulk solution due to altered physicochemical properties of the solvent. Graphical Abstract ᅟ.

Effect of ion composition on oblique magnetosonic waves

International Nuclear Information System (INIS)

Kondo, Yuichi; Toida, Mieko

2011-01-01

The effects of ion composition on oblique magnetosonic waves in a two-ion-species plasma are studied theoretically and numerically. First, it is analytically shown that the KdV equation for the low-frequency mode, the lower branch of magnetosonic waves, is valid for amplitudes ε max (l-) , where ε max (l-) is a measure of the upper limit of the amplitude of the rarefactive solitary pulse of the low-frequency mode and is given as a function of the propagation angle of the wave θ, the density ratio and cyclotron frequency ratio of two ion species. The value of ε max (l-) increases with decreasing θ. Next, with electromagnetic particle simulations, the nonlinear evolution of the low- and high-frequency modes is examined. It is demonstrated that shorter-wavelength low- and high-frequency-mode waves are generated from a long-wavelength low-frequency-mode pulse if its amplitude ε exceeds ε max (l-) . (author)

Cocktail ion beams for SEE testing at TIARA

International Nuclear Information System (INIS)

Okumura, Susumu; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Yokota, Wataru; Tamura, Hiroyuki

1998-01-01

A cocktail ion beam, a mixture of ion species of nearly the same mass-to-charge ratio(M/Q), provides a time-saving method for switching one ion species to another using a cyclotron as a mass analyzer. This method is useful for Single Event Effect (SEE) testing to perform irradiations over a wide range of linear energy transfers (LETs) within one experimental time because the beam switching time diminishes from 1 or 2 hours to less than ten minutes, and one cocktail covers a wide LET range. A cocktail of M/Q = 5 covering a range of high LETs (3.3-40 MeV/(mg/cm 2 )) and a cocktail of M/Q=4 covering a range of low LETs (0.2-36 MeV/(mg/cm 2 )) have been developed. Impurities in the extracted beam caused by insufficient separation, which give ambiguity to the LET data, have been eliminated by specific methods. (author)

Mixed ion beams near transition energy

International Nuclear Information System (INIS)

Hancock, S.

1991-01-01

The standard derivations of the energy and phase of the synchronous particle in a proton accelerator assume, as if by definition, that said synchronous particle lies on the central orbit of the machine. This is manifestly unjustified in the particular case of the acceleration near transition of a mixture of ions, when a small difference in charge-to-mass ratio can produce a large radial separation of the different ion species. The development of a simple derivation of the parameters of the synchronous particle that involves no such a priori constraint has yielded some surprises; not, least, a belated explanation for an apparent anomaly encountered in 1987, when a mixture of oxygen and sulphur ions was accelerated in the CERN Proton Synchrotron for the first time. These ideas are supported by measurements performed in 1990 during a second ion run

Ejection of Coulomb Crystals from a Linear Paul Ion Trap for Ion-Molecule Reaction Studies.

Science.gov (United States)

Meyer, K A E; Pollum, L L; Petralia, L S; Tauschinsky, A; Rennick, C J; Softley, T P; Heazlewood, B R

2015-12-17

Coulomb crystals are being increasingly employed as a highly localized source of cold ions for the study of ion-molecule chemical reactions. To extend the scope of reactions that can be studied in Coulomb crystals-from simple reactions involving laser-cooled atomic ions, to more complex systems where molecular reactants give rise to multiple product channels-sensitive product detection methodologies are required. The use of a digital ion trap (DIT) and a new damped cosine trap (DCT) are described, which facilitate the ejection of Coulomb-crystallized ions onto an external detector for the recording of time-of-flight (TOF) mass spectra. This enables the examination of reaction dynamics and kinetics between Coulomb-crystallized ions and neutral molecules: ionic products are typically cotrapped, thus ejecting the crystal onto an external detector reveals the masses, identities, and quantities of all ionic species at a selected point in the reaction. Two reaction systems are examined: the reaction of Ca(+) with deuterated isotopologues of water, and the charge exchange between cotrapped Xe(+) with deuterated isotopologues of ammonia. These reactions are examples of two distinct types of experiment, the first involving direct reaction of the laser-cooled ions, and the second involving reaction of sympathetically-cooled heavy ions to form a mixture of light product ions. Extensive simulations are conducted to interpret experimental results and calculate optimal operating parameters, facilitating a comparison between the DIT and DCT approaches. The simulations also demonstrate a correlation between crystal shape and image shape on the detector, suggesting a possible means for determining crystal geometry for nonfluorescing ions.

New developments in metal ion implantation by vacuum arc ion sources and metal plasma immersion

International Nuclear Information System (INIS)

Brown, I.G.; Anders, A.; Anders, S.

1996-01-01

Ion implantation by intense beams of metal ions can be accomplished using the dense metal plasma formed in a vacuum arc discharge embodied either in a vacuum arc ion source or in a metal plasma immersion configuration. In the former case high energy metal ion beams are formed and implantation is done in a more-or-less conventional way, and in the latter case the substrate is immersed in the plasma and repetitively pulse-biased so as to accelerate the ions at the high voltage plasma sheath formed at the substrate. A number of advances have been made in the last few years, both in plasma technology and in the surface modification procedures, that enhance the effectiveness and versatility of the methods, including for example: controlled increase of the in charge states produced; operation in a dual metal-gaseous ion species mode; very large area beam formation; macroparticle filtering; and the development of processing regimes for optimizing adhesion, morphology and structure. These complementary ion processing techniques provide the plasma tools for doing ion surface modification over a very wide parameter regime, from pure ion implantation at energies approaching the MeV level, through ion mixing at energies in the ∼1 to ∼100 keV range, to IBAD-like processing at energies from a few tens of eV to a few keV. Here the authors review the methods, describe a number of recent developments, and outline some of the surface modification applications to which the methods have been put. 54 refs., 9 figs

The effect of metal ion implantation on the surface mechanical properties of Mylar (PET)

Energy Technology Data Exchange (ETDEWEB)

Zhou, W.; Sood, D.K. [Royal Melbourne Inst. of Tech., VIC (Australia); Yao, X.; Brown, I.G. [California Univ., Berkeley, CA (United States). Lawrence Berkeley Lab.

1993-12-31

Ion implantation of polymers leads to the formation of new carbonaceous materials, the revolution during implantation of various species consists of (1) ion beam induced damage: chain scission, crosslinking, molecular emission of volatile elements and compounds, stoichiometric change in the surface layer of pristine polymers; and (2) chemical effect between ion and target materials: microalloying and precipitation. Literature regarding ion implanted polymers shows that the reorganisation of the carbon network after implantation can dramatically modify several properties of pristine polymers solubility, molecular weight, and electrical, optical and mechanical properties. However, ion implantation of polymers is actually a very complex interaction which depends on not only ion species, implantation condition, but also polymer type and specific structure. In this paper the effect of Ag or Ti ions implantation on surface mechanical properties of PET (polyethylenne terephthalate) polymer is reported. There was a clear deterioration in wear resistance after implantation of both Ag and Ti ions. It is suggested that the increment of wear after implantation may result from not only ion damage but also chemical effect between ion and target material. 3 refs., 1 tab., 2 figs.

The effect of metal ion implantation on the surface mechanical properties of Mylar (PET)

Energy Technology Data Exchange (ETDEWEB)

Zhou, W; Sood, D K [Royal Melbourne Inst. of Tech., VIC (Australia); Yao, X; Brown, I G [California Univ., Berkeley, CA (United States). Lawrence Berkeley Lab.

1994-12-31

Ion implantation of polymers leads to the formation of new carbonaceous materials, the revolution during implantation of various species consists of (1) ion beam induced damage: chain scission, crosslinking, molecular emission of volatile elements and compounds, stoichiometric change in the surface layer of pristine polymers; and (2) chemical effect between ion and target materials: microalloying and precipitation. Literature regarding ion implanted polymers shows that the reorganisation of the carbon network after implantation can dramatically modify several properties of pristine polymers solubility, molecular weight, and electrical, optical and mechanical properties. However, ion implantation of polymers is actually a very complex interaction which depends on not only ion species, implantation condition, but also polymer type and specific structure. In this paper the effect of Ag or Ti ions implantation on surface mechanical properties of PET (polyethylenne terephthalate) polymer is reported. There was a clear deterioration in wear resistance after implantation of both Ag and Ti ions. It is suggested that the increment of wear after implantation may result from not only ion damage but also chemical effect between ion and target material. 3 refs., 1 tab., 2 figs.

Establishment of an ASEAN Ion Beam Analysis Centre for Material Characterizations at Chiang Mai University

International Nuclear Information System (INIS)

Kamwanna, T.; Junphong, P.; Yu, L.D.; Singkarat, S.; Intarasiri, S.; Suwannakachorn, D.

2015-01-01

A comprehensive ion beam analysis centre unique in the ASEAN (Association of Southeast Asian Nations) region has been established at Chiang Mai University, Thailand. The centre is equipped with a 1.7 MV Tandetron tandem accelerator and a 300 kV medium energy ion beam accelerator for ion beam analysis. The Tandetron accelerator employs two ion sources, a duoplasmatron ion source and a sputter ion source, capable of producing ion beams of both light species (hydrogen and helium) and heavy species. The beamline is currently able to perform ion beam analysis techniques, such as Rutherford backscattering spectrometry (RBS), RBS/channelling, elastic backscattering (EBS), particle induced x ray emission (PIXE) and ionoluminescence (IL) with the assistance of commercial and self-developed software. The medium energy ion accelerator features an ns pulsed beam so that time of flight (ToF) RBS analysis using medium energy ion beams is available for detailed analysis of materials. Ion beam analysis experiments and applications have been vigorously developed for the real time characterization of various materials. Examples are presented and qualities of the ion beam analysis techniques are discussed. (author)

The influence of anode/target ion species on the magnetically immersed

International Nuclear Information System (INIS)

Rovang, Dean Curtis; Welch, Dale Robert; Puetz, Elizabeth A.; Oliver, Bryan Velten; Rose, David Vincent; Bruner, Nichelle Lee

2005-01-01

The magnetically immersed (B z ) diode is being investigated as a source for pulsed-power driven flash radiography. Experiments fielding this diode have revealed a limit on its achievable current density on target. Either a small spot produces a low dose, or a high dose is achieved with a large spot. It has been proposed that this limit is due to non-protonic ions liberated from the anode surface and subsequently ionizing to higher states. The three-dimensional particle-in-cell code LSP is used to investigate this proposal. Data from the recent immersed diode experiments conducted on the RITS-3 accelerator are compared to LSP models of the experimental configuration, including the B z field map. We report on how the non-protonic and protonic ion models compare to data, and proposals for future investigation.

Present status of FLNR (JINR) ECR ion sources

International Nuclear Information System (INIS)

Bogomolov, S.; Efremov, A.; Loginov, V.; Lebedev, A.; Yazvitsy, N.; Bekhterev, V.; Kostukhov, Y.; Gulbekian, G.; Gikal, B.; Drobin, V.; Seleznev, V.; Seleznev, V.

2012-01-01

Six ECR ion sources have been operated in the Flerov Laboratory of Nuclear Reactions (JINR). Two 14 GHz ECR ion sources (ECR4M and DECRIS-2) supply various ion species for the U400 and U400M cyclotrons correspondingly for experiments on the synthesis of heavy and exotic nuclei using ion beams of stable and radioactive isotopes. The 18 GHz DECRIS-SC ion source with superconducting magnet system produces ions from Ar up to W for solid state physics experiments and polymer membrane fabrication at the IC-100 cyclotron. The third 14 GHz ion source DECRIS-4 with 'flat' minimum of the axial magnetic field is used as a stand alone machine for test experiments and also for experiments on ion modification of materials. The other two compact ECR ion sources with all permanent magnet configuration have been developed for the production of single charged ions and are used at the DRIBs installation and at the MASHA mass-spectrometer. In this paper, present status of the ion sources, recent developments and plans for modernization are reported. The paper is followed by the slides of the presentation. (authors)

Grafting: a technique to modify ion accumulation in horticultural crops

Directory of Open Access Journals (Sweden)

Muhammad Azher Nawaz

2016-10-01

Full Text Available Grafting is a centuries-old technique used in plants to obtain economic benefits. Grafting increases nutrient uptake and utilization efficiency in a number of plant species, including fruits, vegetables, and ornamentals. Selected rootstocks of the same species or close relatives are utilized in grafting. Rootstocks absorb more water and ions than self-rooted plants and transport these water and ions to the aboveground scion. Ion uptake is regulated by a complex communication mechanism between the scion and rootstock. Sugars, hormones, and miRNAs function as long-distance signaling molecules and regulate ion uptake and ion homeostasis by affecting the activity of ion transporters. This review summarizes available information on the effect of rootstock on nutrient uptake and utilization and the mechanisms involved. Information on specific nutrient-efficient rootstocks for different crops of commercial importance is also provided. Several other important approaches, such as interstocking (during double grafting, inarching, use of plant-growth-promoting rhizobacteria, use of arbuscular mycorrhizal fungi, use of plant growth substances (e.g., auxin and melatonin, and use of genetically engineered rootstocks and scions (transgrafting, are highlighted; these approaches can be combined with grafting to enhance nutrient uptake and utilization in commercially important plant species. Whether the rootstock and scion affect each other’s soil microbiota and their effect on the nutrient absorption of rootstocks remain largely unknown. Similarly, the physiological and molecular bases of grafting, crease formation, and incompatibility are not fully identified and require investigation. Grafting in horticultural crops can help reveal the basic biology of grafting, the reasons for incompatibility, sensing, and signaling of nutrients, ion uptake and transport, and the mechanism of heavy metal accumulation and restriction in rootstocks. Ion transporter and mi

Contribution to the coordination chemistry of penta, hexa and heptavalent ions of 5f elements

International Nuclear Information System (INIS)

Musikas, Claude.

1978-01-01

This report has two main parts in which are discussed results dealing with: - aquo and hydroxo complexes of penta, hexa and heptavalent ions of 5f elements - pseuso halides complexes of these ions (SCN - , N 3 - , CN - ). It has been shown, by spectrophotometric and electrochemical measurements that U (V) possesses an aquo ion more acid than the known UO 2 + ion. This form is observed as insoluble hydroxid near pH 3.0 or as soluble polynuclear hydroxo complexes at lower pH. Hydroxo anionic complexes of U (VI) have been observed and one can precise the mecanism of hydrolysis of UO 2 ++ ions beyond he hydroxid UO 2 (OH) 2 . At pH 9 to 12, polynuclear species with low negative charge have been observed. At pH 13, others OH - ions enter in the coordination sphere of UO 2 ++ and mononuclear species are obtained. Reduction of polynuclear species leads to mixed hydroxo complexes of 'blue type'. Studies of hydrolysis of NpO 2 + allow to propose an hydrolysis mechanism similar to UO 2 ++ one. With electrochemical methods that in acidic media Np (VII) is present as NpO 3 + ions. Solubility product of NpO 3 OH has been measured. The second part is devoted to pseudohalides complexes of UO 2 ++ , UO 2 + and NpO 2 + ions [fr

Relativistic heavy ions from the BNL [Brookhaven National Laboratory] booster medical research and technological applications

International Nuclear Information System (INIS)

Thieberger, P.

1990-05-01

The BNL Booster, now nearing completion, was designed to inject protons and heavy ions into the Alternating Gradient Synchrotron (AGS) for further acceleration. In the future, ion beams from the AGS will in turn be further accelerated in the Relativistic Heavy Ion Collider (RHIC). Given the wide range of ion masses, energies and beam intensities the Booster will generate, other important applications should be considered. Dedicated use of the Booster for such applications may be possible during limited periods. However shared use would be preferable from the points of view of availability, affordability and efficiency. While heavy ions of a given isotope are injected into the AGS, the same or other ion species from the Booster could be simultaneously delivered to a new irradiation area for treatment of patients, testing of electronic devices or other applications and research. To generate two different beam species, ion sources on both Tandem accelerators would be used; one for AGS injection and the other one for a time-sharing application. Since the beam transport from the Tandems to the Booster can not be rapidly adjusted, it will be necessary to select beams of identical magnetic rigidity. The present study was performed to determine to what extent this compatibility requirement imposes limitations on the available ion species, energies and/or intensities

Acoustic solitary waves in dusty and/or multi-ion plasmas with cold, adiabatic, and hot constituents

International Nuclear Information System (INIS)

Verheest, Frank; Hellberg, Manfred A.; Kourakis, Ioannis

2008-01-01

Large nonlinear acoustic waves are discussed in a four-component plasma, made up of two superhot isothermal species, and two species with lower thermal velocities, being, respectively, adiabatic and cold. First a model is considered in which the isothermal species are electrons and ions, while the cooler species are positive and/or negative dust. Using a Sagdeev pseudopotential formalism, large dust-acoustic structures have been studied in a systematic way, to delimit the compositional parameter space in which they can be found, without restrictions on the charges and masses of the dust species and their charge signs. Solitary waves can only occur for nonlinear structure velocities smaller than the adiabatic dust thermal velocity, leading to a novel dust-acoustic-like mode based on the interplay between the two dust species. If the cold and adiabatic dust are oppositely charged, only solitary waves exist, having the polarity of the cold dust, their parameter range being limited by infinite compression of the cold dust. However, when the charges of the cold and adiabatic species have the same sign, solitary structures are limited for increasing Mach numbers successively by infinite cold dust compression, by encountering the adiabatic dust sonic point, and by the occurrence of double layers. The latter have, for smaller Mach numbers, the same polarity as the charged dust, but switch at the high Mach number end to the opposite polarity. Typical Sagdeev pseudopotentials and solitary wave profiles have been presented. Finally, the analysis has nowhere used the assumption that the dust would be much more massive than the ions and hence, one or both dust species can easily be replaced by positive and/or negative ions and the conclusions will apply to that plasma model equally well. This would cover a number of different scenarios, such as, for example, very hot electrons and ions, together with a mix of adiabatic ions and dust (of either polarity) or a very hot electron

Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry

International Nuclear Information System (INIS)

Chang, C.S.; Hammett, G.W.; Goldston, R.J.

1990-01-01

Neoclassical transport of energetic minority tail ions, which are generated by high powered electromagnetic waves of the Ion Cyclotron Range of Frequencies (ICRF) at the fundamental harmonic resonance, is studied analytically in tokamak geometry. The effect of Coulomb collisions on the tail ion transport is investigated in the present work. The total tail ion transport will be the sum of the present collision-driven transport and the wave-driven transport, which is due to the ICRF-wave scattering of the tail particles as reported in the literature. The transport coefficients have been calculated kinetically, and it is found that the large tail ion viscosity, driven by the localized ICRF-heating and Coulomb slowing-down collisions, induces purely convective particle transport of the tail species, while the energy transport is both convective and diffusive. The rate of radial particle transport is shown to be usually small, but the rate of radial energy transport is larger and may not be negligible compared to the Coulomb slowing-down rate. 18 refs., 2 figs

Accumulation of some metal ions on Bacillus licheniformis

International Nuclear Information System (INIS)

Hafez, M.B.; El-Desouky, W.; Fouad, A.

2001-01-01

Pure species of Bacillus licheniformis was used to remove ions from aqueous and simulated waste solutions. Metal ion accumulation on B. licheniformis was fast. Maximum uptake occurred at pH 4± 0.5 and at 25 ± 3 deg C. One gram of dry B. licheniformis was found to accumulate 115 mg cerium, 34 mg copper and 11 mg cobalt from aqueous solutions. The presence of certain foreign ions such as calcium, sodium and potassium decreased the uptake of ions by B. licheniformis, while citrate and EDTA prevent the uptake. Electron microscopic investigations showed that cerium (III), copper (II) and cobalt (II) accumulated extracellulary around the surface wall of B. licheniformis cells. A bio-adsorption mechanism between the metal ions and B. licheniformis cell wall was proposed. (author)

Ion beam studies - part 4. The use of multiply-charged and polyatomic ions in an implantation accelerator

International Nuclear Information System (INIS)

Freeman, J.H.; Chivers, D.J.; Gard, G.A.

1976-12-01

Polyatomic and multiply-charged ion provide a convenient means of extending the energy range of an implanted accelerator. The molecular species are also of interest in certain special bombardment studies. This report considers some of the factors which affect the production and utilisation of such beams. It introduces the concepts of hetero- and auto-contamination, and particular attention is given to the modification of the charge or mass of the ions resulting from inelastic collisions in the various beams transport regions of the accelerator. (author)

Differentiating Fragmentation Pathways of Cholesterol by Two-Dimensional Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

Science.gov (United States)

van Agthoven, Maria A; Barrow, Mark P; Chiron, Lionel; Coutouly, Marie-Aude; Kilgour, David; Wootton, Christopher A; Wei, Juan; Soulby, Andrew; Delsuc, Marc-André; Rolando, Christian; O'Connor, Peter B

2015-12-01

Two-dimensional Fourier transform ion cyclotron resonance mass spectrometry is a data-independent analytical method that records the fragmentation patterns of all the compounds in a sample. This study shows the implementation of atmospheric pressure photoionization with two-dimensional (2D) Fourier transform ion cyclotron resonance mass spectrometry. In the resulting 2D mass spectrum, the fragmentation patterns of the radical and protonated species from cholesterol are differentiated. This study shows the use of fragment ion lines, precursor ion lines, and neutral loss lines in the 2D mass spectrum to determine fragmentation mechanisms of known compounds and to gain information on unknown ion species in the spectrum. In concert with high resolution mass spectrometry, 2D Fourier transform ion cyclotron resonance mass spectrometry can be a useful tool for the structural analysis of small molecules. Graphical Abstract ᅟ.

Co2+ ion exchange with NaY

International Nuclear Information System (INIS)

Garcia, I.; Solache-Rios, M.; Bulbulian, S.; Bosch, P.

1993-01-01

Co 2+ ion exchange from aqueous cobalt chloride-sodium chloride solutions with NaY zeolite has been investigated. The effect of contact time on the sorption of Co 2+ by dehydrated Y zeolite at 150 degrees C is unusual. A fast sorption uptake is observed in which 1.73 mequiv/g of zeolite of Na + ions is replaced by cobalt ions, followed by a desorption process where the uptake decreases to 1.56 mequiv/g of zeolite. This behavior is explained by the location and coordination of cobalt in Y zeolite sites. It is suggested that the maximum uptake corresponds to cobalt ions being simultaneously in two sites; tetrahedrally coordinated in the sodalite units and octahedrally coordinated in the large cavities. It is also suggested that the desorption process is a consequence of a reaction between Cl - ions and the tetrahedral species. 20 refs., 4 figs

Bioleaching of UO22+ ions from a Romanian poor uranium ore

International Nuclear Information System (INIS)

Cecal, Al.; Popa, K.; Moraru, R.T.; Patachia, S.

2002-01-01

An experimental study on the bioleaching of a poor uranium ore by means of hydrophytic plants Lemna minor and Riccia fluitans, under various operating conditions is discussed. The maximum degree of bioleaching (42%) of the reduced uranium species to U(VI) has been attained for the ore-Lemna minor-alkaline carbonate solution system. The UO 2 2+ ions amount accumulated in the plants is negligible as compared to the dissolved quantity, owing to the ionic competition between uranyl ions and the cations necessary to the mineral nutrition. The X-ray diffraction patterns prove that the uranium species in pyrochlore mineral are completely oxidized to U(VI), while thucolite is only partially turned into UO 2 2+ ions, in the presence of living plants. (author)

The changes in contents of Salt Marsh Species and the importance of Edaphic Physiochemical Factors

International Nuclear Information System (INIS)

Kutbay, Hamdi G.; Demir, M.

2001-01-01

The changes in nutrient contents of some halophytic plants which occurred in a salt marsh located in the vicinity of Bafra town, on the north coast of Turkey during the growing seasons were investigated. Contents of So4, Cl, Na, K, Ca and Mg changed during the growing season in most species. High correlation coefficients were obtained between plant ion and soil ion contents. It has been found that the most prevalent ion was Na in the plant and soil samples. It was also shown that species diversity was quite low in the study area, and species diversity was highly correlated with so4/Cl ratio, electrical conductivity and pH. (author)

Measurement of two ion components in a plasma by collective scattering

International Nuclear Information System (INIS)

Kasparek, W.; Hirsch, K.; Holzhauer, E.

With collective laser scattering a clear separation of the ion features of two ion species with large mass ratio was experimentally realized. Furthermore demixing effects in a H 2 /A mixture as well as a temperature difference were observed. (orig.) 891 HT/orig. 892 HIS

Ultraviolet spectroscopy and metal ions detection

International Nuclear Information System (INIS)

Chaudry, M.A.

1995-01-01

The spectrochemical analysis is based on the interaction of radiation with the chemical species and depends on their nature, having pi, sigma or electrons, or d and f electrons, UV. Visible spectrophotometry has been used extensively in the detection and determination of both organics and inorganics. In UV detection the sensitivity is proportional to the bath length and the excitation coefficient of the given sample. It may be insensitive to many species unless these are converted to UV, absorbing derivatives. The technique has been applied for the monitoring of the effluents from HPLC, as chlorides or other complexes of various elements in this article the utility of HCl as reagent for the spectrophotometric determination of the metal ions like Al(III), As(III,IV), Ba(II), Cd(II), Ca(II) Ce(III), Cs(i), Cr(III,VI), Co(II), Cu(II), Dy(III), Eu(III), Gd(III), Au(III), Hf(IV), Ho(III), In(III), Fe(III), La(III), Pb(II), Lu (III), Mg(II), Mn(II), Hg(II), Mo(VI), Ni(II), Pd(II), Pt(IV), K(I), Pr(III), Re(VII), Ru(IV), Sm(III), Sc(III), Ag(I), Sr(II) Te(III), Th(IV), Sn(II,IV), Ti(III,IV), W(VI), U(VI), V(IV,V), Yb(III), Zn(II) AND Zr(IV) Ions i.e. for meta ions from d of the most of these metal ions has been found sufficient permit their detection in HPLC. Their molar absorptive have also been reported. Reference has also been provided to post column derivatization of some metal ions from d and f block elements for their detection in HPLC. (author) 12 figs.; 6 tabs.; 27 refs

Ion energy/momentum effects during ion assisted growth of niobium nitride films

Science.gov (United States)

Klingenberg, Melissa L.

The research described herein was performed to better understand and discern ion energy vs. ion momentum effects during ion beam assisted (IBAD) film growth and their effects on residual stress, crystalline structure, morphology, and composition, which influence film tribological properties. NbxN y was chosen for this research because it is a refractory material that can possess a large number of crystalline structures, and it has been found to have good tribological properties. To separate the effects of momentum transfer per arriving atom (p/a), which considers bombarding species mass, energy, and ion-to-atom transport ratio, from those of energy deposition per arriving atom (E/a), a mass independent parameter, different inert ion beams (krypton, argon, and neon) were used to create a matrix of coatings formed using similar energy deposition, but different momentum transfer and vice versa. Deposition was conducted in a research-scale IBAD system using electron beam evaporation, a radio frequency ion source, and a neutral nitrogen gas backfill. Films were characterized using x-ray diffraction, atomic force microscopy, Rutherford backscattering spectrometry, and residual stress analysis. Direct and quantifiable effects of bombardment were observed; however, energy deposition and momentum transfer effects could not be completely separated, confirming that thin film processes are complex. Complexities arose from ion-specific interactions (ion size, recoil energy, per cent reflected neutrals, Penning ionization, etc.) and chemistry effects that are not considered by the simple models. Overall, it can be stated that bombardment promoted nitride formation, nanocrystallinity, and compressive stress formation; influenced morphology (which influenced post-deposition oxygen uptake) and stress evolution; increased lattice parameter; modified crystalline phase and texture; and led to inert gas incorporation. High stress levels correlated strongly with material disorder and

The Relativistic Heavy Ion Collider at Brookhaven

International Nuclear Information System (INIS)

Hahn, H.

1989-01-01

The conceptual design of a collider capable of accelerating and colliding heavy ions and to be constructed in the existing 3.8 km tunnel at Brookhaven has been developed. The collider has been designed to provide collisions of gold ions at six intersection points with a luminosity of about 2 x 10 26 cm -2 sec -1 at an energy per nucleon of 100 GeV in each beam. Collisions with different ion species, including protons, will be possible. The salient design features and the reasons for major design choices of the proposed machine are discussed in this paper. 28 refs., 2 figs., 1 tab

An enhanced production of highly charged ions in the ECR ion sources

International Nuclear Information System (INIS)

Schaechter, L.; Dobrescu, S.; Badescu- Singureanu, Al.I.; Stiebing, K.E.; Runkel, S.; Hohn, O.; Schmidt, L.; Schempp, A.; Schmidt - Boecking, H.

2000-01-01

The electron cyclotron resonance (ECR) ion source (ECRIS) are the ideal sources of highly charged heavy ions. Highly charged heavy ions are widely used in atomic physics research where they constitute a very efficient tool due to their very high electric potential of collision. The highly charged ions are also used in fusion plasma physics studies, in solid state surface physics investigations and are very efficient when injected in particle accelerators. More than 50 ECR ion sources are presently working in the whole world. Stable and intense highly charged heavy ions beams are extracted from ECR ion sources, in a wide range of ion species. RECRIS, the Romanian 14 GHz ECR Ion Source, developed in IFIN-HH, designed as a facility for atomic physics and materials studies, has been recently completed. The research field concerning the development of advanced ECRIS and the study of the physical processes of the ECR plasma are presently very dynamical , a fact well proved by the great number of scientific published works and the numerous dedicated international conferences and workshops. It is well established that the performance of ECRIS can substantially be enhanced if special techniques like a 'biased disk' or a special wall coating of the plasma chamber are employed. In the frame of a cooperation project between IFIN-HH ,Bucharest, Romania and the Institut fuer Kernphysik of the J. W. Goethe University, Frankfurt/Main, Germany we developed, on the basis of previous research carried out in IFIN-HH, a new method to strongly increase the intensity of the ion beams extracted from the 14.4 GHz ECRIS in Frankfurt. In our method a special metal-dielectric structure (MD cylinder) was introduced in the ECRIS plasma chamber. In the experiment analyzed beams of Ar 16+ ions were increased in intensity by a factor of 50 as compared to the standard set up with stainless steel chamber. These results have been communicated at the International Conference on Ion Sources held at

Removal of Cobalt Ions by Precipitate Foam Flotation

Energy Technology Data Exchange (ETDEWEB)

Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

1998-09-30

Simulated waste liquid containing 50 ppm cobalt ion was tested by precipitate flotation using a sodium lauryl sulfate as a collector. The effects of initial cobalt ion concentration, pH, surfactant concentration, flotation time, gas flow rate and foreign ions on removal efficiency of cobalt ion were studied. Pretreatment of the waste liquid with 35% H{sub 2}O{sub 2} prior to precipitate flotation made shift of optimal flotation pH from the strong alkalinity to weak alkaline range and made a favorable flotation of cobalt ion in wide range of pH. For the result of this experiment, 99.8% removal efficiency was obtained on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, flotation time 30 min. The simulate ion was formed to be the most harmful ion against removal of cobalt by precipitate flotation of the species which were tested. The presence of 0.1 M of SO{sub 4}{sup 2-} ion decreased removal efficiency of cobalt to 90% while the cobalt were almost entirely removed in the absence of sulfate ion. (author). 11 refs., 8 figs.

Use of ion chromatography for monitoring microbial spoilage in the fruit juice industry.

Science.gov (United States)

Trifirò, A; Saccani, G; Gherardi, S; Vicini, E; Spotti, E; Previdi, M P; Ndagijimana, M; Cavalli, S; Reschiotto, C

1997-05-16

Fruit juices and purees are defined as fermentable, but unfermented, products obtained by mechanical processing of fresh fruits. The presence of undesired metabolites derived from microbial growth can arise from the use of unsuitable fruit or from defects in the production line or subsequent contamination. This involves a loss in the overall quality that cannot be resolved by thermal treatment following the start of fermentation. With these considerations, together with microbiological control, the analysis of different metabolites, which can be considered as microbial growth markers, such as alcohols (i.e. ethanol, etc.), acids (i.e. acetic, fumaric, lactic, etc.) is fundamental in order to achieve a better evaluation of product quality. Enzymatic determination and other single-component analytical techniques are often used for the determination of these metabolites. When the microbial spoilage is not well known, this results in a long and cumbersome procedure. A versatile technique that is capable of determining many metabolites in one analysis could be helpful in improving routine quality control. For this purpose, an ion chromatographic technique, such as ion exclusion, for separation, and diode array spectrophotometry and conductivity, for detection, were evaluated. Both different industrial samples and inoculated samples were analyzed.

Osmoregulation in three species of Ambassidae (Osteichthyes ...

African Journals Online (AJOL)

1989-07-25

Jul 25, 1989 ... the temperature tolerance ranges of the three species (Martin. 1988) suggest that ..... dependent on the period spent in freshwater (Holliday 1971;. Nordlie 1985). .... GILLES, R. 1975. Mechanisms of ion and osmoregulation.

Heavy ion source support gas mixing experiments

International Nuclear Information System (INIS)

Hudson, E.D.; Mallory, M.L.

1977-01-01

Experiments on mixing an easily ionized support gas with the primary ion source gas have produced large beam enhancements for high charge state light ions (masses less than or equal to 20). In the Oak Ridge Isochronous Cyclotron (ORIC), the beam increase has been a factor of 5 or greater, depending on ion species and charge state. Approximately 0.1 cc/min of the easily ionized support gas (argon, krypton, or xenon) is supplied to the ion source through a separate gas line and the primary gas flow is reduced by approximately 30 percent. The proposed mechanism for increased intensity is as follows: The heavier support gas ionizes readily to a higher charge state, providing increased cathode heating. The increased heating permits a reduction in primary gas flow (lower pressure) and the subsequent beam increase

Development of ECR ion source for VEC

International Nuclear Information System (INIS)

Bose, D.K.; Taki, G.S.; Nabhiraj, P.Y.; Pal, G.; Mallik, C.; Bhandari, R.K.

1997-01-01

A 6.4 GHz Electron Cyclotron Resonance Ion Source (ECRIS) was developed at the VEC centre to enable acceleration of heavy ions with the K=130, Variable Energy Cyclotron (VEC). Heavy ions which will be sufficiently energetic after acceleration from the cyclotron will be utilised to explore new fields of research. VEC ECRIS was first made operational in April 1991. Initially the stability and intensity of high charge state (z) beam were poor. Constant efforts were paid to improve source performance. Finally going to high field operation that is improving the plasma confinement, desired stability and high output current were achieved. At present stable 16 O beam up to 50 eμA maximum is available from VEC ECRIS. Many other high- z ion beam of gaseous species are also available. (author)

In situ ion-beam analysis and modification of sol-gel zirconia thin films

International Nuclear Information System (INIS)

Levine, T.E.; Mayer, J.W.

1995-01-01

We report the investigation of ion-beam-induced densification of sol-gel zirconia thin films via in situ ion backscattering spectrometry. We have irradiated three regions of a sample with neon, argon, and krypton ions. For each ion species, a series of irradiation and analysis steps were performed using an interconnected 3 MV tandem accelerator. The technique offers the advantages of minimizing the variation of experimental parameters and sequentially monitoring the densification phenomenon with increasing ion dose

Tumour control in ion beam radiotherapy with different ions in the presence of hypoxia: an oxygen enhancement ratio model based on the microdosimetric kinetic model

Science.gov (United States)

Strigari, L.; Torriani, F.; Manganaro, L.; Inaniwa, T.; Dalmasso, F.; Cirio, R.; Attili, A.

2018-03-01

Few attempts have been made to include the oxygen enhancement ratio (OER) in treatment planning for ion beam therapy, and systematic studies to evaluate the impact of hypoxia in treatment with the beam of different ion species are sorely needed. The radiobiological models used to quantify the OER in such studies are mainly based on the dose-averaged LET estimates, and do not explicitly distinguish between the ion species and fractionation schemes. In this study, a new type of OER modelling, based on the microdosimetric kinetic model, taking into account the specificity of the different ions, LET spectra, tissues and fractionation schemes, has been developed. The model has been benchmarked with published in vitro data, HSG, V79 and CHO cells in aerobic and hypoxic conditions, for different ion irradiation. The model has been included in the simulation of treatments for a clinical case (brain tumour) using proton, lithium, helium, carbon and oxygen ion beams. A study of the tumour control probability (TCP) as a function of oxygen partial pressure, dose per fraction and primary ion type has been performed. The modelled OER depends on both the LET and ion type, also showing a decrease for an increased dose per fraction with a slope that depends on the LET and ion type, in good agreement with the experimental data. In the investigated clinical case, a significant increase in TCP has been found upon increasing the ion charge. Higher OER variations as a function of dose per fraction have also been found for low-LET ions (up to 15% varying from 2 to 8 Gy(RBE) for protons). This model could be exploited in the identification of treatment condition optimality in the presence of hypoxia, including fractionation and primary particle selection.

Determination of trimethylselenonium ion in urine by ion chromatography and inductively coupled plasma mass spectrometry detection

DEFF Research Database (Denmark)

Gammelgaard, Bente; Jessen, K.D.; Kristensen, F.H.

2000-01-01

The selenium species selenite, selenate, selenomethionine (SeMet), and trimethylselenonium iodide (TMSe+) were separated in aqueous solution by ion chromatography. The separation was performed on an Ionpac CS5 cation exchange column by elution with 10 mM oxalic acid and 20 mM potassium sulphate, p...

Ion transport in turbulent edge plasmas

International Nuclear Information System (INIS)

Helander, P.; Massachusetts Inst. of Tech., Cambridge, MA; Hazeltine, R.D.; Catto, P.J.

1996-02-01

Edge plasmas, such as the tokamak scrape-off layer, exist as a consequence of a balance between cross-field diffusion and parallel losses. The former is usually anomalous, and is widely thought to be driven by strong electrostatic turbulence. It is shown that the anomalous diffusion affects the parallel ion transport by giving rise to a new type of thermal force between different ion species. This force is parallel to the magnetic field, but arises entirely because of perpendicular gradients, and could be important for impurity retention in the tokamak divertor. (author)

Realistic modeling of chamber transport for heavy-ion fusion

International Nuclear Information System (INIS)

Sharp, W.M.; Grote, D.P.; Callahan, D.A.; Tabak, M.; Henestroza, E.; Yu, S.S.; Peterson, P.F.; Welch, D.R.; Rose, D.V.

2003-01-01

Transport of intense heavy-ion beams to an inertial-fusion target after final focus is simulated here using a realistic computer model. It is found that passing the beam through a rarefied plasma layer before it enters the fusion chamber can largely neutralize the beam space charge and lead to a usable focal spot for a range of ion species and input conditions

Evidence for radical anion formation during liquid secondary ion mass spectrometry analysis of oligonucleotides and synthetic oligomeric analogues: a deconvolution algorithm for molecular ion region clusters.

Science.gov (United States)

Laramée, J A; Arbogast, B; Deinzer, M L

1989-10-01

It is shown that one-electron reduction is a common process that occurs in negative ion liquid secondary ion mass spectrometry (LSIMS) of oligonucleotides and synthetic oligonucleosides and that this process is in competition with proton loss. Deconvolution of the molecular anion cluster reveals contributions from (M-2H).-, (M-H)-, M.-, and (M + H)-. A model based on these ionic species gives excellent agreement with the experimental data. A correlation between the concentration of species arising via one-electron reduction [M.- and (M + H)-] and the electron affinity of the matrix has been demonstrated. The relative intensity of M.- is mass-dependent; this is rationalized on the basis of base-stacking. Base sequence ion formation is theorized to arise from M.- radical anion among other possible pathways.

Mercuric ions inhibit mitogen-activated protein kinase dephosphorylation by inducing reactive oxygen species

International Nuclear Information System (INIS)

Haase, Hajo; Engelhardt, Gabriela; Hebel, Silke; Rink, Lothar

2011-01-01

Mercury intoxication profoundly affects the immune system, in particular, signal transduction of immune cells. However, the mechanism of the interaction of mercury with cellular signaling pathways, such as mitogen activated protein kinases (MAPK), remains elusive. Therefore, the objective of this study is to investigate three potential ways in which Hg 2+ ions could inhibit MAPK dephosphorylation in the human T-cell line Jurkat: (1) by direct binding to phosphatases; (2) by releasing cellular zinc (Zn 2+ ); and (3) by inducing reactive oxygen species (ROS). Hg 2+ causes production of ROS, measured by dihydrorhodamine 123, and triggers ROS-mediated Zn 2+ release, detected with FluoZin-3. Yet, phosphatase-inhibition is not mediated by binding of Zn 2+ or Hg 2+ . Rather, phosphatases are inactivated by at least two forms of thiol oxidation; initial inhibition is reversible with reducing agents such as Tris(2-carboxyethyl)phosphine. Prolonged inhibition leads to non-reversible phosphatase oxidation, presumably oxidizing the cysteine thiol to sulfinic- or sulfonic acid. Notably, phosphatases are a particularly sensitive target for Hg 2+ -induced oxidation, because phosphatase activity is inhibited at concentrations of Hg 2+ that have only minor impact on over all thiol oxidation. This phosphatase inhibition results in augmented, ROS-dependent MAPK phosphorylation. MAPK are important regulators of T-cell function, and MAPK-activation by inhibition of phosphatases seems to be one of the molecular mechanisms by which mercury affects the immune system.

Neutralization of H-- in energetic collisions with multiply charged ions

International Nuclear Information System (INIS)

Melchert, F.; Benner, M.; Kruedener, S.; Schulze, R.; Meuser, S.; Huber, K.; Salzborn, E.; Uskov, D.B.; Presnyakov, L.P.

1995-01-01

Employing the crossed-beam technique, we have measured absolute cross sections for neutralization of H -- ions in collisions with multiply charged ions Ne q+ (q≤4) and Ar q+ , Xe q+ (q≤8) at center-of-mass energies ranging from 20 to 200 keV. . . It is found that th cross sections are independent of the target ion species. The data are in excellent agreement with quantum calculations. A universal scaling law for the neutralization cross section is given

The Reduction of TED in Ion Implanted Silicon

International Nuclear Information System (INIS)

Jain, Amitabh

2008-01-01

The leading challenge in the continued scaling of junctions made by ion implantation and annealing is the control of the undesired transient enhanced diffusion (TED) effect. Spike annealing has been used as a means to reduce this effect and has proven successful in previous nodes. The peak temperature in this process is typically 1050 deg. C and the time spent within 50 deg. C of the peak is of the order of 1.5 seconds. As technology advances along the future scaling roadmap, further reduction or elimination of the enhanced diffusion effect is necessary. We have shown that raising the peak temperature to 1175 deg. C or more and reduction of the anneal time at peak temperature to less than a millisecond is effective in eliminating enhanced diffusion. We show that it is possible to employ a sequence of millisecond anneal followed by spike anneal to obtain profiles that do not exhibit gradient degradation at the junction and have junction depth and sheet resistance appropriate to the needs of future technology nodes. We have implemented millisecond annealing using a carbon dioxide laser to support high-volume manufacturing of 65 nm microprocessors and system-on-chip products. We further show how the use of molecular ion implantation to produce amorphousness followed by laser annealing to produce solid phase epitaxial regrowth results in junctions that meet the shallow depth and abruptness requirements of the 32 nm node.

The Reduction of TED in Ion Implanted Silicon

Science.gov (United States)

Jain, Amitabh

2008-11-01

The leading challenge in the continued scaling of junctions made by ion implantation and annealing is the control of the undesired transient enhanced diffusion (TED) effect. Spike annealing has been used as a means to reduce this effect and has proven successful in previous nodes. The peak temperature in this process is typically 1050 °C and the time spent within 50 °C of the peak is of the order of 1.5 seconds. As technology advances along the future scaling roadmap, further reduction or elimination of the enhanced diffusion effect is necessary. We have shown that raising the peak temperature to 1175 °C or more and reduction of the anneal time at peak temperature to less than a millisecond is effective in eliminating enhanced diffusion. We show that it is possible to employ a sequence of millisecond anneal followed by spike anneal to obtain profiles that do not exhibit gradient degradation at the junction and have junction depth and sheet resistance appropriate to the needs of future technology nodes. We have implemented millisecond annealing using a carbon dioxide laser to support high-volume manufacturing of 65 nm microprocessors and system-on-chip products. We further show how the use of molecular ion implantation to produce amorphousness followed by laser annealing to produce solid phase epitaxial regrowth results in junctions that meet the shallow depth and abruptness requirements of the 32 nm node.

Ion-pairing reversed-phase chromatography coupled to inductively coupled plasma mass spectrometry as a tool to determine mercurial species in freshwater fish.

Science.gov (United States)

Cheng, Heyong; Chen, Xiaopan; Shen, Lihuan; Wang, Yuanchao; Xu, Zigang; Liu, Jinhua

2018-01-05

Most of analytical community is focused on reversed phase high performance liquid chromatography (RP-HPLC) for mercury speciation by employing mobile phases comprising of high salts and moderate amounts of organic solvents. This study aims at rapid mercury speciation analysis by ion-pairing RP-HPLC with inductively coupled plasma mass spectrometry (ICP-MS) detection only using low salts for the sake of green analytical chemistry. Two ion-pairing HPLC methods were developed on individual usage of positively and negatively charged ion-pairing reagents (tetrabutylammonium hydroxide -TBAH and sodium dodecylbenzene sulfonate -SDBS), where sodium 3-mercapto-1-propysulfonate (MPS) and l-cysteine (Cys) were individually added in mobile phases to transform mercury species into negative and positive Hg-complexes for good resolution. Addition of phenylalanine was also utilized for rapid baseline separation in combination of short C 18 guard columns. Optimum mobile phases of 2.0mM SDBS+2.0mM Cys+1.0mM Phe (pH 3.0) and 4.0mM TBAH+2.0mM MPS+2.0mM Phe (pH 6.0) both achieved baseline separation of inorganic mercury (Hg 2+ ), methylmercury (MeHg), ethylmercury (EtHg) and phenylmercury (PhHg) on two consecutive 12.5-mm C 18 columns. The former mobile phase was selected for mercury speciation in freshwater fish because of short separation time (3.0min). Detection limits of 0.015 for Hg 2+ , 0.014 for MeHg, 0.028 for EtHg and 0.042μgL -1 for PhHg were obtained along with satisfactory precisions of peak height and area (1.0-2.8% for 5.0μgL -1 Hg-mixture standard). Good accordance of determined values of MeHg and total mercury in certified reference materials of fish tissue (GBW 10029) and tuna fish (BCR-463) with certified values as well as good recoveries (91-106%) proved good accuracy of the proposed method. An example application to freshwater fish indicated its potential in routine analysis, where MeHg was presented at 3.7-20.3μgkg -1 as the dominate species. Copyright © 2017

Analytical method for the determination of various arsenic species in rice, rice food products, apple juice, and other juices by ion chromatography-inductively coupled plasma/mass spectrometry.

Science.gov (United States)

Ellingson, David; Zywicki, Richard; Sullivan, Darryl

2014-01-01

Recent studies have shown that there are detectable levels of arsenic (As) in rice, rice food products, and apple juice. This has created significant concern to the public, the food industry, and various regulatory bodies. Classic test methods typically measure total As and are unable to differentiate the various As species. Since different As species have greatly different toxicities, an analytical method was needed to separate and quantify the different inorganic and organic species of As. The inorganic species arsenite [As(+3)] and arsenate [As(+5)] are highly toxic. With this in mind, an ion chromatography-inductively coupled plasma (IC-ICP/MS) method was developed and validated for rice and rice food products that can separate and individually measure multiple inorganic and organic species of As. This allows for the evaluation of the safety or risk associated with any product analyzed. The IC-ICP/MS method was validated on rice and rice food products, and it has been used successfully on apple juice. This paper provides details of the validated method as well as some lessons learned during its development. Precision and accuracy data are presented for rice, rice food products, and apple juice.

Numerical modelling of ion transport in flames

KAUST Repository

Han, Jie; Belhi, Memdouh; Bisetti, Fabrizio; Sarathy, Mani

2015-01-01

that changes in polarizability propagate with decreasing effect from binary transport coefficients to species number densities. We conclude that the chosen polarizability value has a limited effect on the ion distribution in freely propagating flames. We expect

Isotopic exchange rate of cobalt ions between hydrous tin(IV) oxide and aqueous solutions

International Nuclear Information System (INIS)

Inoue, Yasushi; Yamazaki, Hiromichi; Itami, Akira

1989-01-01

The isotopic exchange rate of cobalt ions between hydrous tin(IV) oxide ion exchanger and aqueous solutions was radiochemically measured to obtain fundamental data which are useful for elucidating the ion-exchange kinetics of the material for the transition metal elements. The rate can be understood by considering that the cobalt ions were present in the exchanger as three kinds of species: (A 1 ) Free ions which can diffuse in the exchanger particles, (A 2 ) Weakly bound ions to the exchange sites which exchange rapidly with A 1 , and (B) Covalently fixed ions to the exchange sites which exchange very slowly with A 1 . At low fraction of B, the rate is controlled by the diffusion of A 1 with the effective diffusion coefficient, D eff , the values of which depend on the concentration ratios of A 2 to A 1 . When B predominates over the A species, the concentration ratios of B to A 1 affect greatly D eff . The values of D eff and their activation energy(20 kJ/mol) were also estimated

f-Element Ion Chelation in Highly Basic Media

International Nuclear Information System (INIS)

Paine, R.T.

2000-01-01

A large body of data has been collected over the last fifty years on the chemical behavior of f-element ions. The ions undergo rapid hydrolysis reactions in neutral or basic aqueous solutions that produce poorly understood oxide-hydroxide species; therefore, most of the fundamental f-element solution chemistry has allowed synthetic and separations chemists to rationally design advanced organic chelating ligands useful for highly selective partitioning and separation of f-element ions from complex acidic solution matrices. These ligands and new examples under development allow for the safe use and treatment of solutions containing highly radioactive species. This DOE/EMSP project was undertaken to address the following fundamental objectives: (1) study the chemical speciation of Sr and lanthanide (Ln) ions in basic aqueous media containing classical counter anions found in waste matrices; (2) prepare pyridine N-oxide phosphonates and phosphonic acids that might act as selective chelators for Ln ions in model basic pH waste streams; (3) study the binding of the new chelators toward Ln ions and (4) examine the utility of the chelators as decontamination and dissolution agents under basic solution conditions. The project has been successful in attacking selected aspects of the very difficult problems associated with basic pH solution f-element waste chemistry. In particular, the project has (1) shed additional light on the initial stages of Ln ion sol-gel-precipitate formulation under basic solution conditions; (2) generated new families of pyridine phosphonic acid chelators; (3) characterized the function of the chelators and (4) examined their utility as oxide-hydroxide dissolution agents. These findings have contributed significantly to an improved understanding of the behavior of Ln ions in basic media containing anions found in typical waste sludges as well as to the development of sludge dissolution agents. The new chelating reagents are easily made and could be

Fabrication of nano porous with heavy ions in plastics for the oil industry

International Nuclear Information System (INIS)

Balcazar, M.; Tavera, L.; Mendoza, D.; Mut, A.

2003-01-01

The natural gas has undesirable concentrations of other gases like the nitrogen that reduces the heat capacity of the gas. It is required to develop separation technology to increase the caloric value of the gas. Among the technology in development for the separation of these gases there are the nano membranes; these are polymeric material that when synthesizing them form nano pores that allow the selective separation of the gas. Another form of creating these nano pores with uniform and controlled pore size, is irradiating a polymeric material with heavy ions. The energy loss of the heavy ion produces cylindrical damages around its trajectory in a diameter among 30 x 10 -10 m and 100 x 10 -10 m. This damage breaks the chains of the polymer making it susceptible to the corrosion of appropriate chemical agents that allow to create a pore of the size of some nanometers in the polymer. The basic mechanisms of the interaction of the ions with the polymer are important for the controlled creation, the observation and analysis of these nano pores. One of the more appropriate techniques for the visualization and analysis of the geometry of the produced damages, it is the scanning electron and of the atomic force microscopies. The present work has as objective to define the basic parameters of the interaction of the ion with the polymer that intervene in the fabrication of this nano pores. The conditions of the chemical corrosion process are presented for the creation of micro pores in two polymers CR39 and Makrofol produced by fission fragments and alpha particles. A characterization of the diameters and of the damages profile is make. The obtained results are related with the mechanisms of loss of energy of the ions in the matter and the particles identification in function of the damage geometry. (Author)

Does carbonate ion control planktonic foraminifera shell calcification in upwelling regions?

Digital Repository Service at National Institute of Oceanography (India)

Naik, S.S.; Godad, S.P.; Naidu, P.D.

are still debated and to utilize shell weights of a particular species as a surface water carbonate ion proxy, it is important to understand whether [CO = 3 ] controls shell calcification in that species over a period of time. We therefore utilize...

Spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources. Experimental results

International Nuclear Information System (INIS)

Panitzsch, Lauri

2013-01-01

The experimental determination of the spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources (ECRIS) defines the focus of this thesis. The spatial distributions of different ion species were obtained in the object plane of the bending magnet (∼45 cm downstream from the plasma electrode) and in the plane of the plasma electrode itself, both in high spatial resolution. The results show that each of the different ion species forms a bloated, triangular structure in the aperture of the plasma electrode. The geometry and the orientation of these structures are defined by the superposition of the radial and axial magnetic fields. The radial extent of each structure is defined by the charge of the ion. Higher charge states occupy smaller, more concentrated structures. The total current density increases towards the center of the plasma electrode. The circular and star-like structures that can be observed in the beam profiles of strongly focused, extracted ion beams are each dominated by ions of a single charge state. In addition, the spatially resolved current density distribution of charged particles in the plasma chamber that impinge on the plasma electrode was determined, differentiating between ions and electrons. The experimental results of this work show that the electrons of the plasma are strongly connected to the magnetic field lines in the source and thus spatially well confined in a triangular-like structure. The intensity of the electrons increases towards the center of the plasma electrode and the plasma chamber, as well. These electrons are surrounded by a spatially far less confined and less intense ion population. All the findings mentioned above were already predicted in parts by simulations of different groups. However, the results presented within this thesis represent the first (and by now only) direct experimental verification of those predictions and are qualitatively transferable to other

Spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources. Experimental results

Energy Technology Data Exchange (ETDEWEB)

Panitzsch, Lauri

2013-02-08

The experimental determination of the spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources (ECRIS) defines the focus of this thesis. The spatial distributions of different ion species were obtained in the object plane of the bending magnet ({approx}45 cm downstream from the plasma electrode) and in the plane of the plasma electrode itself, both in high spatial resolution. The results show that each of the different ion species forms a bloated, triangular structure in the aperture of the plasma electrode. The geometry and the orientation of these structures are defined by the superposition of the radial and axial magnetic fields. The radial extent of each structure is defined by the charge of the ion. Higher charge states occupy smaller, more concentrated structures. The total current density increases towards the center of the plasma electrode. The circular and star-like structures that can be observed in the beam profiles of strongly focused, extracted ion beams are each dominated by ions of a single charge state. In addition, the spatially resolved current density distribution of charged particles in the plasma chamber that impinge on the plasma electrode was determined, differentiating between ions and electrons. The experimental results of this work show that the electrons of the plasma are strongly connected to the magnetic field lines in the source and thus spatially well confined in a triangular-like structure. The intensity of the electrons increases towards the center of the plasma electrode and the plasma chamber, as well. These electrons are surrounded by a spatially far less confined and less intense ion population. All the findings mentioned above were already predicted in parts by simulations of different groups. However, the results presented within this thesis represent the first (and by now only) direct experimental verification of those predictions and are qualitatively transferable to

Quantification of the Relative Biological Effectiveness for Ion Beam Radiotherapy: Direct Experimental Comparison of Proton and Carbon Ion Beams and a Novel Approach for Treatment Planning

International Nuclear Information System (INIS)

Elsaesser, Thilo; Weyrather, Wilma K.; Friedrich, Thomas; Durante, Marco; Iancu, Gheorghe; Kraemer, Michael; Kragl, Gabriele; Brons, Stephan; Winter, Marcus; Weber, Klaus-Josef; Scholz, Michael

2010-01-01

Purpose: To present the first direct experimental in vitro comparison of the biological effectiveness of range-equivalent protons and carbon ion beams for Chinese hamster ovary cells exposed in a three-dimensional phantom using a pencil beam scanning technique and to compare the experimental data with a novel biophysical model. Methods and Materials: Cell survival was measured in the phantom after irradiation with two opposing fields, thus mimicking the typical patient treatment scenario. The novel biophysical model represents a substantial extension of the local effect model, previously used for treatment planning in carbon ion therapy for more than 400 patients, and potentially can be used to predict effectiveness of all ion species relevant for radiotherapy. A key feature of the new approach is the more sophisticated consideration of spatially correlated damage induced by ion irradiation. Results: The experimental data obtained for Chinese hamster ovary cells clearly demonstrate that higher cell killing is achieved in the target region with carbon ions as compared with protons when the effects in the entrance channel are comparable. The model predictions demonstrate agreement with these experimental data and with data obtained with helium ions under similar conditions. Good agreement is also achieved with relative biological effectiveness values reported in the literature for other cell lines for monoenergetic proton, helium, and carbon ions. Conclusion: Both the experimental data and the new modeling approach are supportive of the advantages of carbon ions as compared with protons for treatment-like field configurations. Because the model predicts the effectiveness for several ion species with similar accuracy, it represents a powerful tool for further optimization and utilization of the potential of ion beams in tumor therapy.

Negative secondary ion emission from oxidized surfaces

International Nuclear Information System (INIS)

Gnaser, H.; Kernforschungsanlage Juelich G.m.b.H.

1984-01-01

The emission of negative secondary ions from 23 elements was studied for 10 keV O 2 + and 10 keV In + impact at an angle of incidence of 45 0 . Partial oxidation of the sample surfaces was achieved by oxygen bombardment and/or by working at a high oxygen partial pressure. It was found that the emission of oxide ions shows an element-characteristic pattern. For the majority of the elements investigated these features are largely invariant against changes of the surface concentration of oxygen. For the others admission of oxygen strongly changes the relative intensities of oxide ions: a strong increase of MO 3 - signals (M stands for the respective element) is accompanied by a decrease of MO - and M - intensities. Different primary species frequently induce changes of both the relative and the absolute negative ion intensities. Carbon - in contrast to all other elements - does not show any detectable oxide ion emission but rather intense cluster ions Csub(n) - (detected up to n=12) whose intensities oscillate in dependence on n. (orig./RK)

A future, intense source of negative hydrogen ions

Science.gov (United States)

Siefken, Hugh; Stein, Charles

1994-01-01

By directly heating lithium hydride in a vacuum, up to 18 micro-A/sq cm of negative hydrogen has been obtained from the crystal lattice. The amount of ion current extracted and analyzed is closely related to the temperature of the sample and to the rate at which the temperature is changed. The ion current appears to be emission limited and saturates with extraction voltage. For a fixed extraction voltage, the ion current could be maximized by placing a grid between the sample surface and the extraction electrode. Electrons accompanying the negative ions were removed by a magnetic trap. A Wein velocity filter was designed and built to provide definitive mass analysis of the extracted ion species. This technique when applied to other alkali hydrides may produce even higher intensity beams possessing low values of emittance.

Pulse radiolysis of alkanes in the gas-phase, ion-molecule reactions and neutralization mechanisms of hydrocarbon ions

International Nuclear Information System (INIS)

Ausloos, P.

1975-01-01

A discussion is presented of the fate of unreactive hydrocarbon ions in various selected gaseous systems. It is shown that experiments performed with the high radiation dose rates obtained in pulse radiolysis experiments have several advantages over conventional low dose rate experiments for the elucidation of the mechanism of homogeneous neutralization of unreactive hydrocarbon ions. This is so because the charged species has a much shorter lifetime with respect to neutralization under high dose rate (pulse radiolysis) conditions, so that the reaction of the ions with minor impurities or accumulated products is much less probable than in low dose rate experiments. It is further shown through a few examples, that quantitative information about the rate contants of neutralization events and ion-molecule reactions can be obtained when the dose rate is high enough for neutralization and chemical reaction to be in competition. Once reliable rate constants for neutralization and ion-molecule reactions are derived, one can obtain a quantitative evaluation of the products which will by formed in the pulse radiolysis of a hydrocarbon gas mixture from a computer calculation. (author)

Acceleration of heavy-ion beams at the SF cyclotron

International Nuclear Information System (INIS)

Sakurada, Yuzo; Yamazaki, Tsutomu.

1984-10-01

With the development of the new arc-heated cathode PIG type source, heavy-ion acceleration in the SF cyclotron has been drastically augmented, which means that a stable routine operation is being realized as well as the number of ion species is increasing. Excellent performance is also being exhibited with the arc power supply and gas feeding system required for the operation of the heavy-ion source. At present, the gaseous ions which are being accelerated are as follows: He, B, C, N, O, F, Ne, S, Ar and Xe. In the meantime, the metallic ions which are being accelerated likewise are Li, Be, Na, Mg, Al, Si, Cl, Ca, Ti, Fe and Cu. In this paper, results of mainly the research of heavy-ion acceleration conducted during the period from 1983 to July 1984 are described. (author)