WorldWideScience

Sample records for tracked carbon ion

  1. Non-invasive monitoring of therapeutic carbon ion beams in a homogeneous phantom by tracking of secondary ions

    Science.gov (United States)

    Gwosch, K.; Hartmann, B.; Jakubek, J.; Granja, C.; Soukup, P.; Jäkel, O.; Martišíková, M.

    2013-06-01

    Radiotherapy with narrow scanned carbon ion beams enables a highly accurate treatment of tumours while sparing the surrounding healthy tissue. Changes in the patient’s geometry can alter the actual ion range in tissue and result in unfavourable changes in the dose distribution. Consequently, it is desired to verify the actual beam delivery within the patient. Real-time and non-invasive measurement methods are preferable. Currently, the only technically feasible method to monitor the delivered dose distribution within the patient is based on tissue activation measurements by means of positron emission tomography (PET). An alternative monitoring method based on tracking of prompt secondary ions leaving a patient irradiated with carbon ion beams has been previously suggested. It is expected to help in overcoming the limitations of the PET-based technique like physiological washout of the beam induced activity, low signal and to allow for real-time measurements. In this paper, measurements of secondary charged particle tracks around a head-sized homogeneous PMMA phantom irradiated with pencil-like carbon ion beams are presented. The investigated energies and beam widths are within the therapeutically used range. The aim of the study is to deduce properties of the primary beam from the distribution of the secondary charged particles. Experiments were performed at the Heidelberg Ion Beam Therapy Center, Germany. The directions of secondary charged particles emerging from the PMMA phantom were measured using an arrangement of two parallel pixelated silicon detectors (Timepix). The distribution of the registered particle tracks was analysed to deduce its dependence on clinically important beam parameters: beam range, width and position. Distinct dependencies of the secondary particle tracks on the properties of the primary carbon ion beam were observed. In the particular experimental set-up used, beam range differences of 1.3 mm were detectable. In addition, variations

  2. Homologous recombination in Arabidopsis seeds along the track of energetic carbon ions

    International Nuclear Information System (INIS)

    Wang Ting; Li Fanghua; Liu Qingfang; Bian Po; Wang Jufang; Wu Yuejin; Wu Lijun; Li Wenjian

    2012-01-01

    Heavy ion irradiation has been used as radiotherapy of deep-seated tumors, and is also an inevitable health concern for astronauts in space mission. Unlike photons such as X-rays and γ-rays, a high linear energy transfer (LET) heavy ion has a varying energy distribution along its track. Therefore, it is important to determine the correlation of biological effects with the Bragg curve energy distribution of heavy ions. In this study, a continuous biological tissue equivalent was constructed using a layered cylinder of Arabidopsis seeds, which was irradiated with carbon ions of 87.5 MeV/nucleon. The position of energy loss peak in the seed pool was determined with CR-39 track detectors. The mutagenic effect in vivo along the path of carbon ions was investigated with the seeds in each layer as an assay unit, which corresponded to a given position in physical Bragg curve. Homologous recombination frequency (HRF), expression level of AtRAD54 gene, germination rate of seeds, and survival rate of young seedlings were used as checking endpoints, respectively. Our results showed that Arabidopsis S0 and S1 plants exhibited significant increases in HRF compared to their controls, and the expression level of AtRAD54 gene in S0 plants was significantly up-regulated. The depth-biological effect curves for HRF and the expression of AtRAD54 gene were not consistent with the physical Bragg curve. Differently, the depth-biological effect curves for the developmental endpoints matched generally with the physical Bragg curve. The results suggested a different response pattern of various types of biological events to heavy ion irradiation. It is also interesting that except for HRF in S0 plants, the depth-biological effect curves for each biological endpoint were similar for 5 Gy and 30 Gy of carbon irradiation.

  3. Nuclear tracks in CR-39 produced by carbon, oxygen, aluminium and titanium ions.

    Science.gov (United States)

    Rickards, J; Romo, V; Golzarri, J I; Espinosa, G

    2002-01-01

    This work describes the response of CR-39 (allyl diglycol polycarbonate) to different ions (C, O, Al and Ti) produced by the Instituto de Fisica 3 MV 9SDH-2 Pelletron accelerator and backscattered from a thin Au film on a C support. The ion energies were chosen in series such that the ranges of the different ions in the detector were 2, 3, 4, 5, 6, 7 and 8 microm respectively for each series. Once exposed, the detectors were etched with a solution of 6.25 M KOH at 60 degrees C, and the reading was carried out using a digital image analysis system. An analysis of the measured track diameters of all the types of ions indicates that, for a given range, track kinetics are independent of type of ion, energy and stopping power.

  4. Measurement of track structure parameters of low and medium energy helium and carbon ions in nanometric volumes.

    Science.gov (United States)

    Hilgers, G; Bug, M U; Rabus, H

    2017-09-12

    Ionization cluster size distributions produced in the sensitive volume of an ion-counting wall-less nanodosimeter by monoenergetic carbon ions with energies between 45 MeV and 150 MeV were measured at the TANDEM-ALPI ion accelerator facility complex of the LNL-INFN in Legnaro. Those produced by monoenergetic helium ions with energies between 2 MeV and 20 MeV were measured at the accelerator facilities of PTB and with a 241 Am alpha particle source. C 3 H 8 was used as the target gas. The ionization cluster size distributions were measured in narrow beam geometry with the primary beam passing the target volume at specified distances from its centre, and in broad beam geometry with a fan-like primary beam. By applying a suitable drift time window, the effective size of the target volume was adjusted to match the size of a DNA segment. The measured data were compared with the results of simulations obtained with the PTB Monte Carlo code PTra. Before the comparison, the simulated cluster size distributions were corrected with respect to the background of additional ionizations produced in the transport system of the ionized target gas molecules. Measured and simulated characteristics of the particle track structure are in good agreement for both types of primary particles and for both types of the irradiation geometry. As the range in tissue of the ions investigated is within the typical extension of a spread-out Bragg peak, these data are useful for benchmarking not only 'general purpose' track structure simulation codes, but also treatment planning codes used in hadron therapy. Additionally, these data sets may serve as a data base for codes modelling the induction of radiation damages at the DNA-level as they almost completely characterize the ionization component of the nanometric track structure.

  5. Measurement of track structure parameters of low and medium energy helium and carbon ions in nanometric volumes

    Science.gov (United States)

    Hilgers, G.; Bug, M. U.; Rabus, H.

    2017-10-01

    Ionization cluster size distributions produced in the sensitive volume of an ion-counting wall-less nanodosimeter by monoenergetic carbon ions with energies between 45 MeV and 150 MeV were measured at the TANDEM-ALPI ion accelerator facility complex of the LNL-INFN in Legnaro. Those produced by monoenergetic helium ions with energies between 2 MeV and 20 MeV were measured at the accelerator facilities of PTB and with a 241Am alpha particle source. C3H8 was used as the target gas. The ionization cluster size distributions were measured in narrow beam geometry with the primary beam passing the target volume at specified distances from its centre, and in broad beam geometry with a fan-like primary beam. By applying a suitable drift time window, the effective size of the target volume was adjusted to match the size of a DNA segment. The measured data were compared with the results of simulations obtained with the PTB Monte Carlo code PTra. Before the comparison, the simulated cluster size distributions were corrected with respect to the background of additional ionizations produced in the transport system of the ionized target gas molecules. Measured and simulated characteristics of the particle track structure are in good agreement for both types of primary particles and for both types of the irradiation geometry. As the range in tissue of the ions investigated is within the typical extension of a spread-out Bragg peak, these data are useful for benchmarking not only ‘general purpose’ track structure simulation codes, but also treatment planning codes used in hadron therapy. Additionally, these data sets may serve as a data base for codes modelling the induction of radiation damages at the DNA-level as they almost completely characterize the ionization component of the nanometric track structure.

  6. A study of V79 cell survival after for proton and carbon ion beams as represented by the parameters of Katz' track structure model

    DEFF Research Database (Denmark)

    Grzanka, Leszek; Waligórski, M. P. R.; Bassler, Niels

    Katz’s theory of cellular track structure (1) is an amorphous analytical model which applies a set of four cellular parameters representing survival of a given cell line after ion irradiation. Usually the values of these parameters are best fitted to a full set of experimentally measured survival...... carbon irradiation. 1. Katz, R., Track structure in radiobiology and in radiation detection. Nuclear Track Detection 2: 1-28 (1978). 2. Furusawa Y. et al. Inactivation of aerobic and hypoxic cells from three different cell lines by accelerated 3He-, 12C- and 20Ne beams. Radiat Res. 2012 Jan; 177...... curves available for a variety of ions. Once fitted, using these parameter values and the analytical formulae of the model calculations, cellular survival curves and RBE may be predicted for that cell line after irradiation by any ion, including mixed ion fields. While it is known that the Katz model...

  7. Determination of absorbed dose to water in a clinical carbon ion beam by means of fluorescent nuclear track detectors, ionization chambers, and water calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Osinga-Blaettermann, Julia-Maria

    2016-12-20

    Until now, dosimetry of carbon ions with ionization chambers has not reached the same level of accuracy as of high-energy photons. This is mainly caused by the threefold higher uncertainty of the k{sub Q,Q{sub 0}}-factor of ionization chambers, which is derived by calculations due to a lack of experimental data. The current thesis comprises two major aims with respect to the dosimetry of carbon ion beams: first, the investigation of the potential of fluorescent nuclear track detectors for fluence-based dosimetry and second, the experimental determination of the k{sub Q,Q{sub 0}}-factor. The direct comparison of fluence- and ionization-based measurements has shown a significant discrepancy of 4.5 %, which re-opened the discussion on the accuracy of calculated k{sub Q,Q{sub 0}}-factors. Therefore, absorbed dose to water measurements by means of water calorimetry have been performed allowing for the direct calibration of ionization chambers and thus for the experimental determination of k{sub Q,Q{sub 0}}. For the first time it could be shown that the experimental determination of k{sub Q,Q{sub 0}} for carbon ion beams is achievable with a standard measurement uncertainty of 0.8 %. This corresponds to a threefold reduction of the uncertainty compared to calculated values and therefore enables to significantly decrease the overall uncertainty related to ionization-based dosimetry of clinical carbon ion beams.

  8. Spectrometry of linear energy transfer with track-etched detectors in carbon ion beams, MONO and SOBP

    Czech Academy of Sciences Publication Activity Database

    Pachnerová Brabcová, Kateřina; Ambrožová, Iva; Spurný, František

    2011-01-01

    Roč. 143, 2-4 (2011), s. 440-444 ISSN 0144-8420. [International Symposium on Microdosimetry/15./. Verona, 25.10.2009-30.10.2009] R&D Projects: GA ČR GA205/09/0171; GA AV ČR IAA100480902 Institutional research plan: CEZ:AV0Z10480505 Keywords : particles * HIMAC * track-etched detectors Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.822, year: 2011

  9. Proton and carbon ion therapy

    CERN Document Server

    Lomax, Tony

    2013-01-01

    Proton and Carbon Ion Therapy is an up-to-date guide to using proton and carbon ion therapy in modern cancer treatment. The book covers the physics and radiobiology basics of proton and ion beams, dosimetry methods and radiation measurements, and treatment delivery systems. It gives practical guidance on patient setup, target localization, and treatment planning for clinical proton and carbon ion therapy. The text also offers detailed reports on the treatment of pediatric cancers, lymphomas, and various other cancers. After an overview, the book focuses on the fundamental aspects of proton and carbon ion therapy equipment, including accelerators, gantries, and delivery systems. It then discusses dosimetry, biology, imaging, and treatment planning basics and provides clinical guidelines on the use of proton and carbon ion therapy for the treatment of specific cancers. Suitable for anyone involved with medical physics and radiation therapy, this book offers a balanced and critical assessment of state-of-the-art...

  10. Conducting swift heavy ion track networks

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Kiv, A.; Fuks, D.; Vacík, Jiří; Hnatowicz, Vladimír; Chandra, A.; Saad, A.

    2010-01-01

    Roč. 165, č. 3 (2010), s. 227-244 ISSN 1042-0150 R&D Projects: GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z10480505 Keywords : ion tracks * negative differential resistance * neural networks Subject RIV: JJ - Other Materials Impact factor: 0.660, year: 2010

  11. Single track regime in ion implanted polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Licciardello, A.; Puglisi, O.; Calcagno, L.; Foti, G.

    1988-05-01

    The molecular weight distribution (MWD) of nearly monodisperse polystyrene thin films is heavily affected by ion bombardment. The main effect is an increase of the MW and is detectable at fluences as low as 10/sup 11/ ions cm/sup -2/ for 400 keV Ar/sup +/ bombardment. A statistical model, here outlined for the first time, allows us the predict the size distribution of these high MW components. From the analysis of the MWD curves one can extract useful information concerning the lateral dimensions of the ion tracks.

  12. Environment-sensitive ion-track membranes

    International Nuclear Information System (INIS)

    Yoshida, Masaru

    1996-01-01

    Development of an environment-sensitive porous membrane from ion-track membranes may realize by combining the techniques of ion beam radiation and those of molecular designing and synthesis for intelligent materials. Now, the development of such membrane is progressing with an aim at selecting some specific substances and accurately control its pore size in response to any small environmental stimulus such as temperature change. The authors have been studying the molecular design, synthesis and functional expression of intelligent materials, which are called here as environment-sensitive gels. In this report, the outlines of the apparatus for the production of such porous membrane was described. An organic polymer membrane was irradiated with an ion beam and followed by chemical etching to make ion track pores. Scanning electron microscopic observation for the cross section of the membrane showed that the pore shape varies greatly depending on the ion nuclide used. The characteristics of newly produced porous membranes consisting of CR-30/A-ProDMe and polyethylene-telephtharate were investigated in respect of pore size change responding to temperature. These studies of design, synthesis and functions of such gels would enable to substitute artificial materials for the functions of human sensors. (M.N.). 54 refs

  13. Industrial applications of ion track technology

    Science.gov (United States)

    Hanot, H.; Ferain, E.

    2009-03-01

    It4ip sa is a spin out from the Université Catholique de Louvain (Belgium) dedicated to the development and production of unique templates and membranes based on the combination of ion track technology of polymers. It supplies customers with hi-tech products, state-of-the-art research and product development services with template capability to make high value added membranes. Notably based on results coming from several collaborative R&D projects supported by European and Regional funding, recent improvements of ion track technology open new doors for fast growing applications in niche markets. This paper reviews some of these Hi-Tec applications in different fields such as in healthcare (oncology, drug control release combined to implant and artificial organs etc.), energy (fuel cells and batteries etc.), water de-contamination and electronics (OLED etc.).

  14. Ion track pores in intelligent films

    International Nuclear Information System (INIS)

    Asano, Masaharu; Yoshida, Masaru; Omichi, Hideki; Nagaoka, Noriyasu; Kubota, Hitoshi; Katakai, Ryoichi; Reber, N.; Spohr, R.

    1996-01-01

    To create an intelligent chemical valve which behaves to biological membranes, we combined the following technologies: (1) creation of intelligent gels based on pendant α-amino acids or their oligomers, (2) preparation of nuclear track films by etching chemically after heavy ion irradiation, especially preparation of cylindrical pores passed through the film, and (3) a combination of (1) and (2). The two factors, REL (Restricted Energy Loss) and radiation sensitivity [(V t /V b )-1] play an important role in formation of such cylindrical track films. In the case of CR-39 film, there were found to be REL>1.6x10 4 MeV cm 2 g -1 and (V t /V b )-1>100, respectively. The cylindrical tracks films with intelligent functions, which consist of a combination of (1) and (2), can be fabricated by two techniques, copolymerization and grafting. (author)

  15. Heavy-ion irradiation tracks in zircon

    International Nuclear Information System (INIS)

    Bursill, L.A.; Braunshausen, G.

    1989-01-01

    Heavy-ion irradiation (14 MeV/u Pb ions) of zircon crystals gives rise to linear latent tracks of 80x10 -10 m diameter and length 140 μm. Direct observation of the track core, by high-voltage high-resolution electron microscopy at atomic resolution, reveals a core having roughly circular cross-section, with some facetting of the core/matrix interface on [101] planes of zircon. The core diameter appears quite uniform. Conventional transmission electron microscopy (bright- and dark-field imaging) reveals an elastic strain field extending for a short distance into the zircon matrix. This appears to drop off more rapidly with distance, say 1/R 2 , than do dislocation strain fields (∼ 1/R). Analysis of the various contrast mechanisms yields the result that the core is essentially amorphous. The observations confirm directly earlier conclusions based on track etching and electrical conductivity measurements, that the irradiation damage is confirmed to a 50-100 Aangstroem core region of atomically-disordered material, with virtually no damage outside this region. Mechanisms for track production are discussed briefly, but it is concluded that the problem, which is now defined by this structural analysis, has not been fully-appreciated by condensed matter physicists. In particular a damage confinement mechanism is required, which is not intuitively obvious. Some tentative suggestions along this direction are proposed. 33 refs., 9 figs

  16. CR-39 track detector for multi-MeV ion spectroscopy.

    Science.gov (United States)

    Jeong, T W; Singh, P K; Scullion, C; Ahmed, H; Hadjisolomou, P; Jeon, C; Yun, H; Kakolee, K F; Borghesi, M; Ter-Avetisyan, S

    2017-05-19

    We present the characteristics of track formation on the front and rear surfaces of CR-39 produced by laser-driven protons and carbon ions. A methodological approach, based on bulk etch length, is proposed to uniquely characterize the particle tracks in CR-39, enabling comparative description of the track characteristics in different experiments. The response of CR-39 to ions is studied based on the energy dependent growth rate of the track diameter to understand the intrinsic particle stopping process within the material. A large non-uniformity in the track diameter is observed for CR-39 with thickness matching with the stopping range of particles. Simulation and experimental results show the imprint of longitudinal range straggling for energetic protons. Moreover, by exploiting the energy dependence of the track diameter, the energy resolution (δE/E) of CR-39 for few MeV protons and Carbon ion is found to be about 3%.

  17. Track structure for low energy ions including charge exchange processes

    International Nuclear Information System (INIS)

    Uehara, S.; Nikjoo, H.

    2002-01-01

    The model and development is described of a new generation of Monte Carlo track structure codes. The code LEAHIST simulates full slowing down of low-energy proton history tracks in the range 1 keV-1 MeV and the code LEAHIST simulates low-energy alpha particle history tracks in the range 1 keV-8 MeV in water. All primary ion interactions are followed down to 1 keV and all electrons to 1 eV. Tracks of secondary electrons ejected by ions were traced using the electron code KURBUC. Microdosimetric parameters derived by analysis of generated tracks are presented. (author)

  18. Dose Response of Alanine Detectors Irradiated with Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo

    2011-01-01

    Purpose: The dose response of the alanine detector shows a dependence on particle energy and type, when irradiated with ion beams. The purpose of this study is to investigate the response behaviour of the alanine detector in clinical carbon ion beams and compare the results with model predictions....... Methods: Alanine detectors have been irradiated with carbon ions with an energy range of 89-400 MeV/u. The relative effectiveness of alanine has been measured in this regime. Pristine and spread out Bragg peak depth-dose curves have been measured with alanine dosimeters. The track-structure based alanine...

  19. Morphology and annealing kinetics of ion tracks in minerals

    Directory of Open Access Journals (Sweden)

    Ewing R. C.

    2012-10-01

    Full Text Available We have studied the morphology and annealing kinetics of ion tracks in Durango apatite using synchrotron small angle X-ray scattering. The non-destructive, artefact-free technique enables us to determine the track radii with a resolution of fractions of a nanometre. The tracks were generated using different heavy ions with energies between 185 MeV and 2.6 GeV. The track morphology is consistent with the formation of long cylindrical amorphous tracks. The annealing kinetics, measured by SAXS in combination with ex situ and in situ annealing experiments, suggests structural relaxation followed by recrystallisation of the damaged material. The measurement methodology shown here provides a new means for in-depth studies of ion-track formation in minerals under a wide variety of geological conditions.

  20. Iterative reconstruction with boundary detection for carbon ion computed tomography

    Science.gov (United States)

    Shrestha, Deepak; Qin, Nan; Zhang, You; Kalantari, Faraz; Niu, Shanzhou; Jia, Xun; Pompos, Arnold; Jiang, Steve; Wang, Jing

    2018-03-01

    In heavy ion radiation therapy, improving the accuracy in range prediction of the ions inside the patient’s body has become essential. Accurate localization of the Bragg peak provides greater conformity of the tumor while sparing healthy tissues. We investigated the use of carbon ions directly for computed tomography (carbon CT) to create the relative stopping power map of a patient’s body. The Geant4 toolkit was used to perform a Monte Carlo simulation of the carbon ion trajectories, to study their lateral and angular deflections and the most likely paths, using a water phantom. Geant4 was used to create carbonCT projections of a contrast and spatial resolution phantom, with a cone beam of 430 MeV/u carbon ions. The contrast phantom consisted of cranial bone, lung material, and PMMA inserts while the spatial resolution phantom contained bone and lung material inserts with line pair (lp) densities ranging from 1.67 lp cm-1 through 5 lp cm-1. First, the positions of each carbon ion on the rear and front trackers were used for an approximate reconstruction of the phantom. The phantom boundary was extracted from this approximate reconstruction, by using the position as well as angle information from the four tracking detectors, resulting in the entry and exit locations of the individual ions on the phantom surface. Subsequent reconstruction was performed by the iterative algebraic reconstruction technique coupled with total variation minimization (ART-TV) assuming straight line trajectories for the ions inside the phantom. The influence of number of projections was studied with reconstruction from five different sets of projections: 15, 30, 45, 60 and 90. Additionally, the effect of number of ions on the image quality was investigated by reducing the number of ions/projection while keeping the total number of projections at 60. An estimation of carbon ion range using the carbonCT image resulted in improved range prediction compared to the range calculated using a

  1. High energy heavy ion tracks in bubble detectors

    CERN Document Server

    Guo, S L; Guo, H Y; Tu, C Q; Wang, Y L; Doke, T; Kato, T; Ozaki, K; Kyan, A; Piao, Y; Murakami, T

    1999-01-01

    Bubble detectors which are commonly used as neutron detectors have been demonstrated through this study to be good detectors for registration of high energy heavy ion tracks. Large size bubble detectors made in China Institute of Atomic Energy were irradiated to heavy ions Ar and C up to 650 MeV/u and 400 MeV/u, respectively. Very clear features of stringy tracks of high energy heavy ions and their fragmentations are manifested and distinguishable. A single track created by a specific high energy heavy ion is composed of a line of bubbles, which is visible by naked eyes and retained for months without reduction in size. The creation of heavy ion tracks in bubble detectors is governed by a threshold whose essence is approximately a critical value of energy loss rate (dE/dX) sub c similar to that of etch track detectors. Ranges of heavy ions in bubble detectors are apparent and predictable by existing formulas. Identification of high energy heavy ions and the applications to heavy ion physics, cosmic rays, exot...

  2. On the structure of etched ion tracks in polymers

    Czech Academy of Sciences Publication Activity Database

    Hnatowicz, Vladimír; Vacík, Jiří; Apel, P. Yu.

    2016-01-01

    Roč. 121, APR (2016), s. 106-109 ISSN 0969-806X R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(CZ) LM2011019 Institutional support: RVO:61389005 Keywords : polymers * ion tracks * track etching Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.315, year: 2016

  3. Carbon ion radiotherapy for sarcomas

    International Nuclear Information System (INIS)

    Imai, Reiko

    2013-01-01

    Principles of heavy ion therapy, its application to bone and soft tissue sarcomas and outline of its general state are described. The heavy ion therapy has advantages of its high dose distribution to the target and strong biological effect due to the Bragg peak formation and high linear energy transfer, respectively. The authors use carbon ion generated by Heavy Ion Medical Accelerator in Chiba (HIMAC) for the therapy of performance state 0-2 patients with the sarcomas unresectable, diagnosed pathologically, and of 60 y, 45% and teens, 8%) have been treated, whose tumor site has been the pelvis in 73%, volume >600 mL in 63%, tissue type of bone tumor in 70% (where cordoma has amounted to>200 cases). Five-year local control rate is found 71% and survival, 59%. In 175 therapeutically fresh cases with sacral cordoma of median age 67 y, with median clinical target volume 9 cm, treated with median dose 70.4 GyE/16 irradiations, the 8-y local control rate is found to be 69% and survival, 74%, within the median follow-up 54 months; with severe skin ulcer in 2 cases and deterioration of nervous dysfunction in 15 cases; suggesting the therapy is as effective and useful as surgical resection. At present, the therapy is not applicable to Japan health insurance. In the author's hospital, the heavy ion therapy has been conducted to total of >6,000 patients, which amounting to the largest number in the world. Now, 3 Japanese facilities can do the therapy as well and 3 countries in the world.(T.T.)

  4. Heavy ions track structure in a PETP

    Science.gov (United States)

    Ciesla, K.; Starosta, W.

    1995-11-01

    Differential scanning calorimetry (DSC) studies of poly(ethylenetherephtalate) (PETP) film irradiated with high energy heavy ions at high ions fluencies are reported. Thin Mylar and Hostaphan PETP films (23 μm or 19 μm thick) were irradiated with Ar, Dy and Pb ions of the following energies and ions fluencies: Ar - 5.5 MeV/amu, 6 × 10 11ions/cm 2; Dy - 13 MeV/amu, 5 × 10 10ions/cm 2 and ca. 10 11 ions/cm 2; Pb - 11.4 MeV/amu, 10 10 ions/cm 2. DSC measurements were performed in nitrogen during heating-cooling-heating cycles at heating-cooling-heating rates of: 10-10-10°/min and 2-20-2°/min. Significant differences between pristine and the irradiated material were observed during melting and recrystallization processes occurring on primary heating, cooling and secondary heating. They have been attributed to film amorphization during heavy ion irradiation as a result of degradation and crosslinking, confirmed by gel permeation chromatography (GPC). The decrease in crystallinity and disappearance of long range order in the highly irradiated samples have been confirmed by wide and small angle X-ray scattering (WAXS, SAXS) results and density measurements. This can also be concluded on the basis of IR spectroscopy patterns. The DSC method can be applied in studies of structural changes occurring in thin polymer films after heavy ion irradiation.

  5. Preparation of fluoropolymer-based ion-track membranes. Structure of latent tracks and pretreatment effect

    International Nuclear Information System (INIS)

    Yamaki, Tetsuya; Nuryanthi, Nuryanthi; Koshikawa, Hiroshi; Sawada, Shinichi; Hakoda, Teruyuki; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari

    2012-01-01

    High-energy heavy-ion induced damage, called latent tracks m organic polymers can sometimes be etched out chemically to give submicro- and nano-sized pores. Our focus is placed on ion-track membranes of poly(vinylidene fluoride) (PVDF), a type of fluoropolymer, which were previously considered as a matrix of polymer electrolyte fuel-cell membranes. There have been no optimized methods of preparing the PVDF-based ion-track membranes. We thus examined chemical structures of the defects created in the track, and accordingly, presented a pretreatment technique for achieving more efficient track etching. A 25 μm-thick PVDF film was bombarded with 1.1 GeV 238 U or 450 MeV 129 Xe ions. In the multi-purpose chamber, degradation processes were monitored in-situ by FT-IR spectroscopy and residual gas analysis as a function of the fluence up to 6.0 x 10 11 ions/cm 2 . The films irradiated at 8 ions/cm 2 were etched in a 9 M KOH aqueous solution at 80degC. We also performed the conductometric etching, which allows monitoring of pore evolution versus etching time by recording the electrical conductance through the membrane. At fluences above 1 x 10 10 ions/cm 2 , the film showed two new absorption bands identified as double-bond stretching vibrations of in-chain unsaturations -CH=CF- and fluorinated vinyl groups -CF 2 CH=CF 2 . These defects would result from the evolution of HF. The knowledge of the solubility in a permanganate alkaline solution and our preliminary experiment suggested the importance of oxidized tracks for the easy introduction of the etching agent. We finally found that the pretreatment with ozone could oxidize the double bonds in the tracks, thereby vigorously promoting track etching before breakthrough. (author)

  6. Monte-Carlo Simulations of Heavy Ions Track Structures and Applications

    Science.gov (United States)

    Plante, Ianik; Cucinotta, Francia A.

    2013-01-01

    In space, astronauts are exposed to protons, high ]energy heavy (HZE) ions that have a high charge (Z) and energy (E), and secondary radiation, including neutrons and recoil nuclei produced by nuclear reactions in spacecraft walls or in tissue. The astronauts can only be partly shielded from these particles. Therefore, on travelling to Mars, it is estimated that every cell nucleus in an astronaut fs body would be hit by a proton or secondary electron (e.g., electrons of the target atoms ionized by the HZE ion) every few days and by an HZE ion about once a month. The risks related to these heavy ions are not well known and of concern for long duration space exploration missions. Medical ion therapy is another situation where human beings can be irradiated by heavy ions, usually to treat cancer. Heavy ions have a peculiar track structure characterized by high levels of energy ]deposition clustering, especially in near the track ends in the so ]called eBragg peak f region. In radiotherapy, these features of heavy ions can provide an improved dose conformation with respect to photons, also considering that the relative biological effectiveness (RBE) of therapeutic ions in the plateau region before the peak is sufficiently low. Therefore, several proton and carbon ion therapy facilities are under construction at this moment

  7. Tracking Progress in Carbon Capture and Storage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-06

    At the second Clean Energy Ministerial in Abu Dhabi, April 2011 (CEM 2), the Carbon Capture, Use and Storage Action Group (CCUS AG) presented seven substantive recommendations to Energy Ministers on concrete, near-term actions to accelerate global carbon capture and storage (CCS) deployment. Twelve CCUS AG governments agreed to advance progress against the 2011 recommendations by the third Clean Energy Ministerial (London, 25-26 April 2012) (CEM 3). Following CEM 2, the CCUS AG requested the IEA and the Global CCS Institute to report on progress made against the 2011 recommendations at CEM 3. Tracking Progress in Carbon Capture and Storage: International Energy Agency/Global CCS Institute report to the third Clean Energy Ministerial responds to that request. The report considers a number of key questions. Taken as a whole, what advancements have committed CCUS AG governments made against the 2011 recommendations since CEM 2? How can Energy Ministers continue to drive progress to enable CCS to fully contribute to climate change mitigation? While urgent further action is required in all areas, are there particular areas that are currently receiving less policy attention than others, where efforts could be redoubled? The report concludes that, despite developments in some areas, significant further work is required. CCS financing and industrial applications continue to represent a particularly serious challenge.

  8. Ion tracking in photocathode rf guns

    Directory of Open Access Journals (Sweden)

    John W. Lewellen

    2002-02-01

    Full Text Available Projected next-generation linac-based light sources, such as PERL or the TESLA free-electron laser, generally assume, as essential components of their injector complexes, long-pulse photocathode rf electron guns. These guns, due to their design rf pulse durations of many milliseconds to continuous wave, may be more susceptible to ion bombardment damage of their cathodes than conventional rf guns, which typically use rf pulses of microsecond duration. This paper explores this possibility in terms of ion propagation within the gun, and presents a basis for future study of the subject.

  9. Structural analysis of simulated swift heavy ion tracks in quartz

    International Nuclear Information System (INIS)

    Leino, Aleksi A.; Daraszewicz, Szymon L.; Pakarinen, Olli H.; Djurabekova, Flyura; Nordlund, Kai; Afra, Boshra; Kluth, Patrick

    2014-01-01

    Swift heavy ions (SHI), of specific kinetic energies in the excess of 1 MeV/u, can create cylindrical regions of structural transformation in SiO 2 targets, also known as SHI tracks. Recent measurements of the track cross-sections in α-quartz show significant and consistent discrepancies across different experimental techniques used. In particular, the track radii obtained from channelling experiments based on the Rutherford Backscattering Spectrometry (RBS-c) method increase monotonically with the electronic stopping power, whereas the track radii obtained from the Small Angle X-ray scattering (SAXS) saturate past a certain stopping power threshold. We perform a systematic study of the structure of the α-quartz tracks obtained from the molecular dynamics (MD) simulations incorporating a time-dependent energy deposition based on the inelastic thermal spike model, which allows us to discuss the possible origins of these experimental discrepancies

  10. Ion range measurements using fluorescent nuclear track detectors

    DEFF Research Database (Denmark)

    Klimpki, G.; Osinga, J.-M.; Herrmann, R.

    2013-01-01

    Fluorescent nuclear track detectors (FNTDs) show excellent detection properties for heavy charged particles and have, therefore, been investigated in this study in terms of their potential for in-vivo range measurements. We irradiated FNTDs with protons as well as with C, Mg, S, Fe and Xe ion beams...

  11. Ion track structure in poly(di-n-hexylsilane)

    International Nuclear Information System (INIS)

    Seki, S.; Maeda, K.; Kunimi, Y.

    2000-01-01

    Solid films of poly(di-n-hexylsilane) were irradiated with a variety of high energy ion beams, electron beams, and 60 Co γ-rays of which LET ranges from 0.2 to 1620 eV/nm. The beams caused non-homogeneous reactions of crosslinking and main chain scission in the films. The relative efficiency of the crosslinking was drastically changed in comparison with that of main chain scission. The anomalous change in the molecular weight distribution was analyzed with increasing irradiation fluence, and the ion beam induced reaction radius: track radius was determined for the radiation sources by the function of molecular weight dispersion. The molecular weight of the polymer was also traced to give the efficiency of crosslinking reactions: G(x) based on Charlesby-Pinner relationship. The value of G(x) increases from 0.042 to 0.91 with increasing values of LET. We adopt a reaction model in a single ion track to the crosslinking reactions, and the expanding chemical track along an ion trajectory is responsible for the increasing crosslinking G-values. The theoretical aspects of the energy distribution in penumbra area give a good interpretation to the chemical track radii obtained in this study. (author)

  12. Ion track structure in poly(di-n-hexylsilane)

    Energy Technology Data Exchange (ETDEWEB)

    Seki, S.; Maeda, K.; Kunimi, Y. [Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research] [and others

    2000-03-01

    Solid films of poly(di-n-hexylsilane) were irradiated with a variety of high energy ion beams, electron beams, and {sup 60}Co {gamma}-rays of which LET ranges from 0.2 to 1620 eV/nm. The beams caused non-homogeneous reactions of crosslinking and main chain scission in the films. The relative efficiency of the crosslinking was drastically changed in comparison with that of main chain scission. The anomalous change in the molecular weight distribution was analyzed with increasing irradiation fluence, and the ion beam induced reaction radius: track radius was determined for the radiation sources by the function of molecular weight dispersion. The molecular weight of the polymer was also traced to give the efficiency of crosslinking reactions: G(x) based on Charlesby-Pinner relationship. The value of G(x) increases from 0.042 to 0.91 with increasing values of LET. We adopt a reaction model in a single ion track to the crosslinking reactions, and the expanding chemical track along an ion trajectory is responsible for the increasing crosslinking G-values. The theoretical aspects of the energy distribution in penumbra area give a good interpretation to the chemical track radii obtained in this study. (author)

  13. Study of ion tracks by micro-probe ion energy loss spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Vacík, Jiří; Havránek, Vladimír; Hnatowicz, Vladimír; Horák, Pavel; Fink, Dietmar; Apel, P. Yu.

    2014-01-01

    Roč. 332, AUG (2014), s. 308-311 ISSN 0168-583X. [21st International Conference on Ion Beam Analysis (IBA). Seattle, 23.06.2013-28.06.2013] R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : ion energy loss spectrometry * single ion track * microprobe * tomography Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.124, year: 2014

  14. Controlled fabrication of ion track nanowires and channels

    Science.gov (United States)

    Spohr, Reimar; Zet, Cristian; Eberhard Fischer, Bernd; Kiesewetter, Helge; Apel, Pavel; Gunko, Igor; Ohgai, Takeshi; Westerberg, Lars

    2010-03-01

    We describe a system for fabricating prescribed numbers of ion track nanochannels and nanowires from a few hundred down to one. It consists of two parts: first, a mobile tape transport system, which, in connection with an ion beam from a heavy-ion accelerator (nuclear charge Z above 18 and specific energy between 1 and 10 MeV/nucleon) tuned down to low flux density by means of defocusing and a set of sensitive fluorescence screens, can fabricate a series of equidistant irradiation spots on a tape, whereby each spot corresponds to a preset number of ion tracks. The tape transport system uses films of 36 mm width and thicknesses between 5 and 100 μm. The aiming precision of the system depends on the diameter of the installed beam-defining aperture, which is between 50 and 500 μm. The distance between neighboring irradiation spots on the tape is variable and typically set to 25 mm. After reaching the preset number of ion counts the irradiation is terminated, the tape is marked and moved to the next position. The irradiated frames are punched out to circular membranes with the irradiation spot in the center. The second part of the setup is a compact conductometric system with 10 picoampere resolution consisting of a computer controlled conductometric cell, sealing the membrane hermetically between two chemically inert half-chambers containing electrodes and filling/flushing openings, and is encased by an electrical shield and a thermal insulation. The ion tracks can be etched to a preset diameter and the system can be programmed to electroreplicate nanochannels in a prescribed sequence of magnetic/nonmagnetic metals, alloys or semiconductors. The goal of our article is to make the scientific community aware of the special features of single-ion fabrication and to demonstrate convincingly the significance of controlled etching and electro-replication.

  15. Ion track etching revisited: I. Correlations between track parameters in aged polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Munoz, G. H.; García Arellano, H.; Vacík, Jiří; Hnatowicz, Vladimír; Kiv, A.; Alfonta, L.

    2018-01-01

    Roč. 420, č. 4 (2018), s. 57-68 ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : ion track * polymer * etching Subject RIV: BG - Nuclear, Atomic and Molecular Physics , Colliders OBOR OECD: Nuclear physics Impact factor: 1.109, year: 2016

  16. Recent Developments in the Code RITRACKS (Relativistic Ion Tracks)

    Science.gov (United States)

    Plante, Ianik; Ponomarev, Artem L.; Blattnig, Steve R.

    2018-01-01

    The code RITRACKS (Relativistic Ion Tracks) was developed to simulate detailed stochastic radiation track structures of ions of different types and energies. Many new capabilities were added to the code during the recent years. Several options were added to specify the times at which the tracks appear in the irradiated volume, allowing the simulation of dose-rate effects. The code has been used to simulate energy deposition in several targets: spherical, ellipsoidal and cylindrical. More recently, density changes as well as a spherical shell were implemented for spherical targets, in order to simulate energy deposition in walled tissue equivalent proportional counters. RITRACKS is used as a part of the new program BDSTracks (Biological Damage by Stochastic Tracks) to simulate several types of chromosome aberrations in various irradiation conditions. The simulation of damage to various DNA structures (linear and chromatin fiber) by direct and indirect effects has been improved and is ongoing. Many improvements were also made to the graphic user interface (GUI), including the addition of several labels allowing changes of units. A new GUI has been added to display the electron ejection vectors. The parallel calculation capabilities, notably the pre- and post-simulation processing on Windows and Linux machines have been reviewed to make them more portable between different systems. The calculation part is currently maintained in an Atlassian Stash® repository for code tracking and possibly future collaboration.

  17. Mechanical Design of Carbon Ion Optics

    Science.gov (United States)

    Haag, Thomas

    2005-01-01

    Carbon Ion Optics are expected to provide much longer thruster life due to their resistance to sputter erosion. There are a number of different forms of carbon that have been used for fabricating ion thruster optics. The mechanical behavior of carbon is much different than that of most metals, and poses unique design challenges. In order to minimize mission risk, the behavior of carbon must be well understood, and components designed within material limitations. Thermal expansion of the thruster structure must be compatible with thermal expansion of the carbon ion optics. Specially designed interfaces may be needed so that grid gap and aperture alignment are not adversely affected by dissimilar material properties within the thruster. The assembled thruster must be robust and tolerant of launch vibration. The following paper lists some of the characteristics of various carbon materials. Several past ion optics designs are discussed, identifying strengths and weaknesses. Electrostatics and material science are not emphasized so much as the mechanical behavior and integration of grid electrodes into an ion thruster.

  18. Ion track etching revisited: I. Correlations between track parameters in aged polymers

    Science.gov (United States)

    Fink, D.; Muñoz H., G.; García A., H.; Vacik, J.; Hnatowicz, V.; Kiv, A.; Alfonta, L.

    2018-04-01

    Some yet poorly understood problems of etching of pristine and swift heavy ion track-irradiated aged polymers were treated, by applying conductometry across the irradiated foils during etching. The onset times of etchant penetration across pristine foils, and the onset times of the different etched track regimes in irradiated foils were determined for polymers of various proveniences, fluences and ages, as well as their corresponding etching speeds. From the results, correlations of the parameters with each other were deduced. The normalization of these parameters enables one to compare irradiated polymer foils of different origin and treatment with one another. In a number of cases, also polymeric gel formation and swelling occur which influence the track etching behaviour. The polymer degradation during aging influences the track etching parameters, which differ from each other on both sides of the foils. With increasing sample age, these differences increase.

  19. Single track coincidence measurements of fluorescent and plastic nuclear track detectors in therapeutic carbon beams

    Czech Academy of Sciences Publication Activity Database

    Osinga, J. M.; Ambrožová, Iva; Pachnerová Brabcová, Kateřina; Akselrod, M. S.; Jäkel, O.; Davídková, Marie; Greilich, S.

    2014-01-01

    Roč. 9, APR (2014), P04013 ISSN 1748-0221 R&D Projects: GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : instrumentation for heavy-ion therapy * particle tracking detectors * solid-state detectors * heavy-ion detectors * hybrid detectors Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.399, year: 2014

  20. Investigations of heavy ion tracks in polyethylene naphthalate films

    CERN Document Server

    Starosta, W; Sartowska, B; Buczkowski, M

    1999-01-01

    The heavy ion beam (with fluence 3x10 sup 8 ion/cm sup 2) from a cyclotron has been used for irradiation of thin polyethylene naphthalate (PEN) films. Latent tracks in these polymeric films have been sensitized by UV radiation and then chemically etched in NaOH solution. The etching process parameters have been controlled by the electroconductivity method. After etching, parameters of samples have been examined by SEM and bubble point methods (Coulter[reg] Porometer II instrument). Results have shown good quality of PEN track membranes with pore sizes in the range: 0.1 - 0.5 mu m. The described procedure is known for thin polyethylene terephthalate (PET) films. Taking into consideration that PEN films have got better mechanical, thermal, gas barrier as well as better chemical resistance properties in comparison with PET films, the possibility of application of such membranes is much wider.

  1. Ion track filters in imaging X-ray astronomy

    Science.gov (United States)

    Mitrofanov, A. V.; Apel, P. Yu.

    2006-04-01

    The application of ion track filters as blocking cut-off filters for solar telescopes in imaging X-ray astronomy is presented. Ion track membranes (ITMs) of high-porosity constitute a randomly inhomogeneous medium with sub-micrometer or micrometer open pores which not only transmits X-ray or extreme ultra violet (EUV) radiation and blocks long-wavelength UV radiation, but also transfers a focused imaging pattern with high-quality for further registration by means of CCD or imaging detectors of other types. X-ray and EUV filters based on ITMs with cylindrical parallel pores were successfully used as detector filters in the solar X-ray telescopes designed and manufactured at the Lebedev Physical Institute of the Russian Academy of Sciences (LPI, Moscow).

  2. Radiation dose-response curves: cell repair mechanisms vs. ion track overlapping

    Science.gov (United States)

    Kowalska, Agata; Czerski, Konrad; Nasonova, Elena; Kutsalo, Polina; Krasavin, Eugen

    2017-12-01

    Chromosome aberrations in human lymphocytes exposed to different doses of particle radiation: 150 MeV and spread out Bragg peak proton beams, 22 MeV/u boron beam and 199 V/u carbon beam were studied. For comparison, an experiment with 60Co γ-rays was also performed. We investigated distributions of aberration frequency and the shape of dose-response curves for the total aberration yield as well as for exchange and non-exchange aberrations, separately. Applying the linear-quadratic model, we could derive a relation between the fitted parameters and the ion track radius which could explain experimentally observed curvature of the dose-response curves. The results compared with physical expectations clearly show that the biological effects of cell repair are much more important than the ion track overlapping. Contribution to the Topical Issue "Dynamics of Systems at the Nanoscale", edited by Andrey Solov'yov and Andrei Korol.

  3. Alanine Radiation Detectors in Therapeutic Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo

    of the depth dose curves. Solid state detectors, such as diamond detectors, radiochromic films, TLDs and the amino acid alanine are used due to there good spatial resolution. If used in particle beams their response often exhibits a dependence on particle energy and type, so the acquired signal is not always...... proportional to absorbed dose. A model by Hansen and Olsen, based on the Track Structure Theory is available, which can predict the relative efficiency of some detectors, when the particle spectrum is known. For alanine detectors the model was successfully validated by Hansen and Olsen for several ion species...... at energies below 20 MeV/u. We implemented this model in the Monte Carlo code FLUKA. At the GSI heavy ion facility in Darmstadt, Germany, alanine has been irradiated with carbon ions at energies between 88 an 400 MeV/u, which is the energy range used for therapy. The irradiation and the detector response have...

  4. Visualization of complex DNA damage along accelerated ions tracks

    Science.gov (United States)

    Kulikova, Elena; Boreyko, Alla; Bulanova, Tatiana; Ježková, Lucie; Zadneprianetc, Mariia; Smirnova, Elena

    2018-04-01

    The most deleterious DNA lesions induced by ionizing radiation are clustered DNA double-strand breaks (DSB). Clustered or complex DNA damage is a combination of a few simple lesions (single-strand breaks, base damage etc.) within one or two DNA helix turns. It is known that yield of complex DNA lesions increases with increasing linear energy transfer (LET) of radiation. For investigation of the induction and repair of complex DNA lesions, human fibroblasts were irradiated with high-LET 15N ions (LET = 183.3 keV/μm, E = 13MeV/n) and low-LET 60Co γ-rays (LET ≈ 0.3 keV/μm) radiation. DNA DSBs (γH2AX and 53BP1) and base damage (OGG1) markers were visualized by immunofluorecence staining and high-resolution microscopy. The obtained results showed slower repair kinetics of induced DSBs in cells irradiated with accelerated ions compared to 60Co γ-rays, indicating induction of more complex DNA damage. Confirming previous assumptions, detailed 3D analysis of γH2AX/53BP1 foci in 15N ions tracks revealed more complicated structure of the foci in contrast to γ-rays. It was shown that proteins 53BP1 and OGG1 involved in repair of DNA DSBs and modified bases, respectively, were colocalized in tracks of 15N ions and thus represented clustered DNA DSBs.

  5. Carbon Mineralization Using Phosphate and Silicate Ions

    Science.gov (United States)

    Gokturk, H.

    2013-12-01

    Carbon dioxide (CO2) reduction from combustion of fossil fuels has become an urgent concern for the society due to marked increase in weather related natural disasters and other negative consequences of global warming. CO2 is a highly stable molecule which does not readily interact with other neutral molecules. However it is more responsive to ions due to charge versus quadrupole interaction [1-2]. Ions can be created by dissolving a salt in water and then aerosolizing the solution. This approach gives CO2 molecules a chance to interact with the hydrated salt ions over the large surface area of the aerosol. Ion containing aerosols exist in nature, an example being sea spray particles generated by breaking waves. Such particles contain singly and doubly charged salt ions including Na+, Cl-, Mg++ and SO4--. Depending on the proximity of CO2 to the ion, interaction energy can be significantly higher than the thermal energy of the aerosol. For example, an interaction energy of 0.6 eV is obtained with the sulfate (SO4--) ion when CO2 is the nearest neighbor [2]. In this research interaction between CO2 and ions which carry higher charges are investigated. The molecules selected for the study are triply charged phosphate (PO4---) ions and quadruply charged silicate (SiO4----) ions. Examples of salts which contain such molecules are potassium phosphate (K3PO4) and sodium orthosilicate (Na4SiO4). The research has been carried out with first principle quantum mechanical calculations using the Density Functional Theory method with B3LYP functional and Pople type basis sets augmented with polarization and diffuse functions. Atomic models consist of the selected ions surrounded by water and CO2 molecules. Similar to the results obtained with singly and doubly charged ions [1-2], phosphate and silicate ions attract CO2 molecules. Energy of interaction between the ion and CO2 is 1.6 eV for the phosphate ion and 3.3 eV for the silicate ion. Hence one can expect that the selected

  6. Etching behaviour of alpha-recoil tracks in natural dark mica studied via artificial ion tracks

    International Nuclear Information System (INIS)

    Lang, M.; Glasmacher, U.A.; Neumann, R.; Wagner, G.A.

    2003-01-01

    Alpha-recoil tracks (ARTs) created by the α-decay of U, Th, and their daughter nuclei, are used by a new dating method to determine the formation age of dark mica bearing Quaternary and Neogene volcanic rocks and the cooling age of plutonic and metamorphic rocks [Chem. Geol. 166 (2000) 127, Science 155 (1967) 1103]. The age equation combines the volumetric density of ARTs with the U and Th contents. Etching latent ARTs (diameter 30-100 nm) in the mica mineral phlogopite by HF and measuring the areal density of triangular etch pits by optical and scanning force microscopy (SFM) leads to a linear growth of ART areal density versus etching time. The ART volume density is a function of the slope of the areal density and the etching rate (v eff ). Therefore, the determination of v eff is essential for the calculation of an age value. To determine the etching parameters such as etching efficiency and v eff , phlogopite samples were irradiated with 80 keV Au ions. Irradiated surfaces were etched with 4% HF at 23±2 deg. C during successive time intervals and after each interval studied with SFM. The etching rate v eff was determined by different techniques. To evaluate the threshold of etchability, the energy losses of the Au ions and α-recoil nuclei in phlogopite were calculated with the SRIM00 code. The etching efficiency of the Au ion tracks was then used to predict the corresponding etching efficiency of the natural radioactive nuclei

  7. Focused ion beam milling of carbon fibres

    International Nuclear Information System (INIS)

    Huson, Mickey G.; Church, Jeffrey S.; Hillbrick, Linda K.; Woodhead, Andrea L.; Sridhar, Manoj; Van De Meene, Allison M.L.

    2015-01-01

    A focused ion beam has been used to mill both individual carbon fibres as well as fibres in an epoxy composite, with a view to preparing flat surfaces for nano-indentation. The milled surfaces have been assessed for damage using scanning probe microscopy nano-indentation and Raman micro-probe analysis, revealing that FIB milling damages the carbon fibre surface and covers surrounding areas with debris of disordered carbon. The debris is detected as far as 100 μm from the milling site. The energy of milling as well as the orientation of the beam was varied and shown to have an effect when assessed by Raman spectroscopy. - Highlights: • Focused ion beam (FIB) milling was used to mill flat surfaces on carbon fibres. • Raman spectroscopy showed amorphous carbon was generated during FIB milling. • The amorphous debris is detected as far as 100 μm from the milling site. • This surface degradation was confirmed by nano-indentation experiments.

  8. Radial dose distribution around an energetic heavy ion and an ion track structure model

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Katsutoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ohno, Shin-ichi; Namba, Hideki; Taguchi, Mitsumasa; Watanabe, Ritsuko

    1997-03-01

    Ionization currents produced in a small wall-less ionization chamber located at varying distance from the 200 MeV Ni{sup 12+} ion`path traversing Ar gas were measured and utilized to construct a track structure model. Using the LET value of 200 MeV Ni{sup 12+} and G(Fe{sup 3+}) in Fricke solutions (= 15.4) for fast electrons, we estimate G(Fe{sup 3+}) for this ion to be 5.0. (author)

  9. Clinical advantages of carbon-ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tsujii, Hirohiko; Kamada, Tadashi; Baba, Masayuki; Tsuji, Hiroshi; Kato, Hirotoshi; Kato, Shingo; Yamada, Shigeru; Yasuda, Shigeo; Yanagi, Takeshi; Kato, Hiroyuki; Hara, Ryusuke; Yamamoto, Naotaka; Mizoe, Junetsu [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Inage-ku, Anagawa 4-9-1, Chiba-shi, Chiba 263-8555 (Japan)], E-mail: tsujii@nirs.go.jp

    2008-07-15

    Carbon-ion radiotherapy (C-ion RT) possesses physical and biological advantages. It was started at NIRS in 1994 using the Heavy Ion Medical Accelerator in Chiba (HIMAC); since then more than 50 protocol studies have been conducted on almost 4000 patients with a variety of tumors. Clinical experiences have demonstrated that C-ion RT is effective in such regions as the head and neck, skull base, lung, liver, prostate, bone and soft tissues, and pelvic recurrence of rectal cancer, as well as for histological types including adenocarcinoma, adenoid cystic carcinoma, malignant melanoma and various types of sarcomas, against which photon therapy could be less effective. Furthermore, when compared with photon and proton RT, a significant reduction of overall treatment time and fractions has been accomplished without enhancing toxicities. Currently, the number of irradiation sessions per patient averages 13 fractions spread over approximately three weeks. This means that in a carbon therapy facility a larger number of patients than is possible with other modalities can be treated over the same period of time.

  10. Visualization of air and metal inhomogeneities in phantoms irradiated by carbon ion beams using prompt secondary ions.

    Science.gov (United States)

    Gaa, T; Reinhart, M; Hartmann, B; Jakubek, J; Soukup, P; Jäkel, O; Martišíková, M

    2017-06-01

    Non-invasive methods for monitoring of the therapeutic ion beam extension in the patient are desired in order to handle deteriorations of the dose distribution related to changes of the patient geometry. In carbon ion radiotherapy, secondary light ions represent one of potential sources of information about the dose distribution in the irradiated target. The capability to detect range-changing inhomogeneities inside of an otherwise homogeneous phantom, based on single track measurements, is addressed in this paper. Air and stainless steel inhomogeneities, with PMMA equivalent thickness of 10mm and 4.8mm respectively, were inserted into a PMMA-phantom at different positions in depth. Irradiations of the phantom with therapeutic carbon ion pencil beams were performed at the Heidelberg Ion Beam Therapy Center. Tracks of single secondary ions escaping the phantom under irradiation were detected with a pixelized semiconductor detector Timepix. The statistical relevance of the found differences between the track distributions with and without inhomogeneities was evaluated. Measured shifts of the distal edge and changes in the fragmentation probability make the presence of inhomogeneities inserted into the traversed medium detectable for both, 10mm air cavities and 1mm thick stainless steel. Moreover, the method was shown to be sensitive also on their position in the observed body, even when localized behind the Bragg-peak. The presented results demonstrate experimentally, that the method using distributions of single secondary ion tracks is sensitive to the changes of homogeneity of the traversed material for the studied geometries of the target. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  11. SU-D-BRB-02: Investigations of Secondary Ion Distributions in Carbon Ion Therapy Using the Timepix Detector.

    Science.gov (United States)

    Gwosch, K; Hartmann, B; Jakubek, J; Granja, C; Soukup, P; Jaekel, O; Martisikova, M

    2012-06-01

    Due to the high conformity of carbon ion therapy, unpredictable changes in the patient's geometry or deviations from the planned beam properties can result in changes of the dose distribution. PET has been used successfully to monitor the actual dose distribution in the patient. However, it suffers from biological washout processes and low detection efficiency. The purpose of this contribution is to investigate the potential of beam monitoring by detection of prompt secondary ions emerging from a homogeneous phantom, simulating a patient's head. Measurements were performed at the Heidelberg Ion-Beam Therapy Center (Germany) using a carbon ion pencil beam irradiated on a cylindrical PMMA phantom (16cm diameter). For registration of the secondary ions, the Timepix detector was used. This pixelated silicon detector allows position-resolved measurements of individual ions (256×256 pixels, 55μm pitch). To track the secondary ions we used several parallel detectors (3D voxel detector). For monitoring of the beam in the phantom, we analyzed the directional distribution of the registered ions. This distribution shows a clear dependence on the initial beam energy, width and position. Detectable were range differences of 1.7mm, as well as vertical and horizontal shifts of the beam position by 1mm. To estimate the clinical potential of this method, we measured the yield of secondary ions emerging from the phantom for a beam energy of 226MeV/u. The differential distribution of secondary ions as a function of the angle from the beam axis for angles between 0 and 90° will be presented. In this setup the total yield in the forward hemisphere was found to be in the order of 10 -1 secondary ions per primary carbon ion. The presented measurements show that tracking of secondary ions provides a promising method for non-invasive monitoring of ion beam parameters for clinical relevant carbon ion fluences. Research with the pixel detectors was carried out in frame of the Medipix

  12. Carbonate ions and arsenic dissolution by groundwater

    Science.gov (United States)

    Kim, M.-J.; Nriagu, J.; Haack, S.

    2000-01-01

    Samples of Marshall Sandstone, a major source of groundwater with elevated arsenic levels in southeast Michigan, were exposed to bicarbonate ion under controlled chemical conditions. In particular, effects of pH and redox conditions on arsenic release were evaluated. The release of arsenic from the aquifer rock was strongly related to the bicarbonate concentration in the leaching solution. The results obtained suggest that the carbonation of arsenic sulfide minerals, including orpiment (As2S3) and realgar (As2S2), is an important process in leaching arsenic into groundwater under anaerobic conditions. The arseno-carbonate complexes formed, believed to be As(CO3)2-, As(CO3)(OH)2-, and AsCO3+, are stable in groundwater. The reaction of ferrous ion with the thioarsenite from carbonation process can result in the formation of arsenopyrite which is a common mineral in arsenic-rich aquifers.Samples of Marshall Sandstone, a major source of groundwater with elevated arsenic levels in southeast Michigan, were exposed to bicarbonate ion under controlled chemical conditions. In particular, effects of pH and redox conditions on arsenic release were evaluated. The release of arsenic from the aquifer rock was strongly related to the bicarbonate concentration in the leaching solution. The results obtained suggest that the carbonation of arsenic sulfide minerals, including orpiment (As2S3) and realgar (As2S2), is an important process in leaching arsenic into groundwater under anaerobic conditions. The arseno-carbonate complexes formed, believed to be As(CO3)2-, As(CO3)(OH)2-, and AsCO3+, are stable in groundwater. The reaction of ferrous ion with the thioarsenite from carbonation process can result in the formation of arsenopyrite which is a common mineral in arsenic-rich aquifers.The role of bicarbonate in leaching arsenic into groundwater was investigated by conducting batch experiments using core samples of Marshall Sandstone from southeast Michigan and different bicarbonate

  13. The separation of heavy ion tracks in nuclear emulsions by means of the pulsed electric field

    International Nuclear Information System (INIS)

    Akopova, A.B.; Magradze, N.V.; Melkumyan, L.V.; Prokhorenko, Y.P.

    1976-01-01

    The pulsed electric field (PEF) technique is developed for the separation of heavy ion tracks from the intense background caused by high energy electrons, protons and γ-radiation. The tracks of Ne, Cr, Ar-ions accelerated at the Dubna Nuclear Reactions Laboratory have been separated from the background, the voltage of the applied PEF being 10 5 V/cm. (orig.) [de

  14. Electrochemical synthesis of metallic microstructures using etched ion tracks in nuclear track filters

    International Nuclear Information System (INIS)

    Sanjeev Kumar; Shyam Kumar; Rajesh Kumar; Chakravarti, K.

    2004-01-01

    Interest in nano/microstructures results from their numerous potential applications in various areas such as materials and biomedical sciences, electronics, optics, magnetism, energy storage and electrochemistry. Materials with micro/nanoscopic dimensions not only have potential technological applications in areas such as device technology and drug delivery, but also are of fundamental interest in that the properties of a material can change in this regime of transition between the bulk and molecular scales. Electrodeposition is a versatile technique combining low processing cost with ambient conditions that can be used to prepare metallic, polymeric and semiconducting microstructures. In the present work ion track membranes of Makrofol (KG) have been used as templates for synthesis of metallic microstructures using the technique of electrodeposition. (author)

  15. Resolution of the carbon contamination problem in ion irradiation experiments

    Science.gov (United States)

    Was, G. S.; Taller, S.; Jiao, Z.; Monterrosa, A. M.; Woodley, D.; Jennings, D.; Kubley, T.; Naab, F.; Toader, O.; Uberseder, E.

    2017-12-01

    The widely experienced problem of carbon uptake in samples during ion irradiation was systematically investigated to identify the source of carbon and to develop mitigation techniques. Possible sources of carbon included carbon ions or neutrals incorporated into the ion beam, hydrocarbons in the vacuum system, and carbon species on the sample and fixture surfaces. Secondary ion mass spectrometry, atom probe tomography, elastic backscattering spectrometry, and principally, nuclear reaction analysis, were used to profile carbon in a variety of substrates prior to and following irradiation with Fe2+ ions at high temperature. Ion irradiation of high purity Si and Ni, and also of alloy 800H coated with a thin film of alumina eliminated the ion beam as the source of carbon. Hydrocarbons in the vacuum and/or on the sample and fixtures was the source of the carbon that became incorporated into the samples during irradiation. Plasma cleaning of the sample and sample stage, and incorporation of a liquid nitrogen cold trap both individually and especially in combination, completely eliminated the uptake of carbon during heavy ion irradiation. While less convenient, coating the sample with a thin film of alumina was also effective in eliminating carbon incorporation.

  16. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  17. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  18. Shunting arc plasma source for pure carbon ion beam.

    Science.gov (United States)

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

  19. The geometry of etched heavy ion tracks in phlogopite mica; a clear dependence on energy deposited

    International Nuclear Information System (INIS)

    Hashemi-Nezhad, S.R.

    2005-01-01

    It is shown that the etched track contour geometry in phlogopite mica depends on the extent of the radiation damage present in the track core. At low stopping power values (i.e. low radiation damage), the tracks have triangular (T) geometries while at high damage densities, track contours become polygons which are hexagonal (H) for normally incident fission fragments. For these tracks, the track contour geometry along the track can change from H to T or vice versa due to variations in the extent of radiation damage. Such geometry changes are abrupt and sudden. For fragments with dip angles less than 90 deg. , the track contour geometry can be hexagonal, irregular polygon and triangular. The observed etch figures can be explained on the basis of energy deposited by the heavy ions and thermodynamic quantities of the track-crystal system

  20. Detection of coloured tracks of heavy ion particles using photographic colour film

    International Nuclear Information System (INIS)

    Kuge, K.; Yasuda, N.; Kumagai, H.; Nakazawa, K.; Kobayashi, T.; Aoki, N.; Hasegawa, A.

    2001-01-01

    A photographic colour film, which was exposed to heavy ions, reveals a coloured dye image of the ion tracks. Since the colour film consists of several layers and different colours appear on each layer, three-dimensional information on the tracks in the layers can be obtained by the colour image. Previously, we have reported the method for which the tracks in different colours represented differences of track depth and we also discussed the disadvantages of using commercial colour films. Here we present the procedure for a self-made photographic coating and the development formula which can overcome the disadvantages

  1. Radial dose distributions from carbon ions of therapeutic energies calculated with Geant4-DNA.

    Science.gov (United States)

    Wang, He; Vassiliev, Oleg N

    2017-05-21

    We report on radial dose distributions [Formula: see text] for carbon ions calculated with Geant4-DNA code. These distributions characterize ion tracks on a nanoscale and are important for understanding the biological effects of ion beams. We present data for carbon ion beams in the energy range from 20 to 400 MeV u -1 . To approximate the Monte Carlo results, we developed a simple formula that combines the well-known inverse square distance dependence with a factor correcting [Formula: see text] for small [Formula: see text]. The proposed formula can be used to calculate [Formula: see text] for any energy within the above range and for distances [Formula: see text] from 1 nm to 2 μm with a maximum error not exceeding 14%. This range of distances corresponds to a dose range of over seven orders of magnitude. Differences between our results and those of previously published analytical models are discussed.

  2. A simple and rapid method for high-resolution visualization of single-ion tracks

    Directory of Open Access Journals (Sweden)

    Masaaki Omichi

    2014-11-01

    Full Text Available Prompt determination of spatial points of single-ion tracks plays a key role in high-energy particle induced-cancer therapy and gene/plant mutations. In this study, a simple method for the high-resolution visualization of single-ion tracks without etching was developed through the use of polyacrylic acid (PAA-N, N’-methylene bisacrylamide (MBAAm blend films. One of the steps of the proposed method includes exposure of the irradiated films to water vapor for several minutes. Water vapor was found to promote the cross-linking reaction of PAA and MBAAm to form a bulky cross-linked structure; the ion-track scars were detectable at a nanometer scale by atomic force microscopy. This study demonstrated that each scar is easily distinguishable, and the amount of generated radicals of the ion tracks can be estimated by measuring the height of the scars, even in highly dense ion tracks. This method is suitable for the visualization of the penumbra region in a single-ion track with a high spatial resolution of 50 nm, which is sufficiently small to confirm that a single ion hits a cell nucleus with a size ranging between 5 and 20 μm.

  3. Carbon Ion Radiotherapy for Unresectable Retroperitoneal Sarcomas

    International Nuclear Information System (INIS)

    Serizawa, Itsuko; Kagei, Kenji; Kamada, Tadashi; Imai, Reiko; Sugahara, Shinji; Okada, Tohru; Tsuji, Hiroshi; Ito, Hisao; Tsujii, Hirohiko

    2009-01-01

    Purpose: To evaluate the applicability of carbon ion radiotherapy (CIRT) for unresectable retroperitoneal sarcomas with regard to normal tissue morbidity and local tumor control. Methods and Materials: From May 1997 to February 2006, 24 patients (17 male and 7 female) with unresectable retroperitoneal sarcoma received CIRT. Age ranged from 16 to 77 years (median, 48.6 years). Of the patients, 16 had primary disease and 8 recurrent disease. Histologic diagnoses were as follows: malignant fibrous histiocytoma in 6, liposarcoma in 3, malignant peripheral nerve sheath tumor in 3, Ewing/primitive neuroectodermal tumor (PNET) in 2, and miscellaneous in 10 patients. The histologic grades were as follows: Grade 3 in 15, Grade 2-3 in 2, Grade 2 in 3, and unknown in 4. Clinical target volumes ranged between 57 cm 3 and 1,194 cm 3 (median 525 cm 3 ). The delivered carbon ion dose ranged from 52.8 to 73.6 GyE in 16 fixed fractions over 4 weeks. Results: The median follow-up was 36 months (range, 6-143 months). The overall survival rates at 2 and 5 years were 75% and 50%, respectively. The local control rates at 2 and 5 years were 77% and 69%. No complications of the gastrointestinal tract were encountered. No other toxicity greater than Grade 2 was observed. Conclusions: Use of CIRT is suggested to be effective and safe for retroperitoneal sarcomas. The results obtained with CIRT were a good overall survival rate and local control, notwithstanding the fact that most patients were not eligible for surgical resection and had high-grade sarcomas.

  4. Coupled chemical reactions in dynamic nanometric confinement: Ag2O membrane formation during ion track etching

    Czech Academy of Sciences Publication Activity Database

    Hernandez, G. M.; Cruz, S. A.; Quintero, R.; Arellano, H. G.; Fink, Dietmar; Alfonta, L.; Mandabi, Y.; Kiv, A.; Vacík, Jiří

    2013-01-01

    Roč. 168, č. 9 (2013), s. 675-695 ISSN 1042-0150 Institutional support: RVO:61389005 Keywords : track * polymers * etching * chemistry * ions * nanostructure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.603, year: 2013

  5. Glucose determination using a re-usable enzyme-modified ion track membrane sensor

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Klinkovich, I.; Bukelman, O.; Marks, R.S.; Kiv, A.; Fuks, D.; Fahrner, W. R.; Alfonta, L.

    2009-01-01

    Roč. 24, č. 8 (2009), s. 2702-2706 ISSN 0956-5663 Institutional research plan: CEZ:AV0Z10480505 Keywords : Glucose sensor * etched tracks * Ion track membranes Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 5.429, year: 2009

  6. SAXS investigation of un-etched and etched ion tracks in polycarbonate

    Science.gov (United States)

    Hossain, U. H.; Rodriguez, M. D.; Schauries, D.; Hadley, A.; Schleberger, M.; Trautmann, C.; Mudie, S.; Kluth, P.

    2017-10-01

    Investigation of the ion track morphologies and track etching behaviour in polycarbonate (PC) films was carried out using synchrotron based small-angle X-ray scattering (SAXS) measurements. The tracks were induced by Au ions with kinetic energies of 1.7 and 2.2 GeV with applied fluences between 1 × 1010 and 1 × 1012 ions/cm2. The average radii of the un-etched tracks were studied as a function of the irradiation fluence, indicating a general ion induced degradation of the polymer, with a simultaneous increase in ion track radius from 2.6 ± 0.002 nm to 3.4 ± 0.03 nm. Chemical etching of the ion tracks in PC leads to the formation of cylindrical pores. The pore radius increases linearly with etching time. In 3 M NaOH at 55 °C, a radial etching rate of 9.2 nm/min is observed.

  7. Characterization of carbon ion-induced mutations in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Shikazono, N.; Suzuki, C.; Kitamura, S.; Watanabe, H.; Tano, S.; Tanaka, A.

    2003-01-01

    Full text: Irradiation of Arabidopsis thaliana by carbon ions was carried out to investigate the mutational effect of ion particles in higher plants. The averaged mutation rate of carbon ions was 2.0 X 10 -6 / Gy, which was 18-fold higher than that of electrons. PCR analysis of the carbon ion-induced mutants showed that, out of 28 mutant alleles, 14 had point-like mutations within the gene, while 14 contained large structural alterations. In the case of 12 electron-induced mutants, 9 had point-like mutations within the gene, while 3 contained large structural alterations. These results suggest that carbon ions are more likely to induce large structural alterations compared with electrons. Further sequence analysis revealed that most of the point-like mutations induced by carbon ions were short deletions. In the case of rearrangements, DNA strand breaks were found to be rejoined using, if present, short homologous sequences for both types of radiation. After carbon ion-irradiation, small deletions were frequently observed around the breakpoints, whereas duplications of terminal sequence were found after electron-irradiation. These results suggest that non-homologous end joining (NHEJ) pathway operates after plant cells are exposed to both ion particles and electrons but that different mode of rejoining deals with the broken ends produced by each radiation. From the present results, it seems reasonable to assume that carbon ions could predominantly induce null mutations in Arabidopsis. The fact that the molecular nature of carbon ion-induced mutation was different from that of electrons and that the molecular mechanisms of cells to induce mutations appeared to be also different implicates that ion particle is not only valuable as a new mutagen but also useful as a new tool to study repair mechanisms of certain types of DNA damage

  8. Carbon contaminant in the ion processing of aluminum oxide film

    International Nuclear Information System (INIS)

    Chaug, Y.; Roy, N.

    1989-01-01

    Ion processing can induce contamination on the bombarded surface. However, this process is essential for the microelectronics device fabrication. Auger electron spectroscopy has been used to study the simultaneous deposition of carbon impurity during ion bombardment of magnetron rf-sputtering deposited aluminum oxide film. Ion bombardment on aluminum oxide results in a preferential removal of surface oxygen and a formation of a metastable state of aluminum suboxide. Cosputtered implanted carbon contaminant appears to have formed a new state of stoichiometry on the surface of the ion bombarded aluminum oxide and existed as an aluminum carbide. This phase has formed due to the interaction of the implanted carbon and the aluminum suboxide. The Ar + ion sputter etching rate is reduced for the carbon contaminated oxide. The electrical resistance of the aluminum oxide between two gold strips has been measured. It is found that the electrical resistance is also reduced due to the formation of the new stoichiometry on the surface

  9. Monte Carlo simulation of carbon ion radiotherapy for Human Eye

    OpenAIRE

    Pang, Chengguo; Su, Youwu; Yao, Zeen; Xu, Junkui; Li, Wuyuan; Yuan, Jiao

    2014-01-01

    Carbon ion is the mostly common used particle in heavy ion radiotherapy. In this paper, carbon ion dose in tumor treatment for human eye was simulated with FLUKA code, 80 MeV/u carbon beam was irradiated into the human eye from two directions, The first is from the lateral-forward direction which was a typical therapeutic condition, maximum dose was deposited in the tumor volume. The second one was that beam irradiated into eyes from the forward direction which may cause certain medical accid...

  10. An Ion Beam Tracking System based on a Parallel Plate Avalanche Counter

    Directory of Open Access Journals (Sweden)

    Carter I. P.

    2013-12-01

    Full Text Available A pair of twin position-sensitive parallel plate avalanche counters have been developed at the Australian National University as a tracking system to aid in the further rejection of unwanted beam particles from a 6.5 T super conducting solenoid separator named SOLEROO. Their function is to track and identify each beam particle passing through the detectors on an event-by-event basis. In-beam studies have been completed and the detectors are in successful operation, demonstrating the tracking capability. A high efficiency 512-pixelwide-angle silicon detector array will then be integrated with the tracking system for nuclear reactions studies of radioactive ions.

  11. Damage morphology of Kr ion tracks in apatite: Dependence on dE/dX

    CERN Document Server

    Villa, F; Rebetez, M; Dubois, C; Chambaudet, A; Chevarier, A; Martin, P; Brossard, F; Blondiaux, G; Sauvage, T; Toulemonde, M

    1999-01-01

    With the aim of characterizing damage along nuclear tracks in apatite, Durango fluoroapatite monocrystals were irradiated under a high fluence sup 8 sup 6 Kr ion beam at the G.A.N.I.L. (Grand Accelerateur National d'Ions Lourds, Caen, France). The resulting irradiation damage was studied by associating CRBS spectrometry and chemical etching. By applying Poisson's law to the backscattering results, the nuclear track average effective radius R sub e was calculated for different steps along the ion path. On the other hand, the chemical etching experiments allowed us to deduce three different damaging morphologies in correspondence to the R sub e values. For the first time in apatite, it has been shown that a defect fragmentation produced along the ion paths may be detected by chemical etching. These results were also applied to fission tracks in order to quantify the damage rate and to describe the damage morphology evolution along fission fragment paths.

  12. Lead ions removal from aqueous solution using modified carbon ...

    Indian Academy of Sciences (India)

    33

    modified carbon nanotubes. 1. Introduction. Recently, in Vietnam and many other countries, the pollution of water by inorganic and organic compounds has increased with the development of industry. The presence of heavy metal ions in.

  13. Heavy metal ion adsorption onto polypyrrole-impregnated porous carbon.

    Science.gov (United States)

    Choi, Moonjung; Jang, Jyongsik

    2008-09-01

    Polypyrrole-impregnated porous carbon was readily synthesized using vapor infiltration polymerization of pyrrole monomers. The results show that the functionalized polymer layer was successfully coated onto the pore surface of carbon without collapse of mesoporous structure. The modified porous carbon exhibited an improved complexation affinity for heavy metal ions such as mercury, lead, and silver ions due to the amine group of polypyrrole. The introduced polypyrrole layer could provide the surface modification to be applied for heavy metal ion adsorbents. Especially, polymer-impregnated porous carbon has an enhanced heavy metal ion uptake, which is 20 times higher than that of adsorbents with amine functional groups. Furthermore, the relationship between the coated polymer amount and surface area was also investigated in regard to adsorption capacity.

  14. Ionization of RNA-uracil by highly charged carbon ions

    Science.gov (United States)

    Champion, C.; Galassi, M. E.; Fojón, O.; Lekadir, H.; Hanssen, J.; Rivarola, R. D.; Weck, P. F.; Agnihotri, A. N.; Nandi, S.; Tribedi, L. C.

    2012-07-01

    We present a theoretical description of highly charged carbon ion-induced ionization of isolated RNA-uracil molecules. A comparison between recent experimental and theoretical total cross sections is provided.

  15. Surface modification of commercial tin coatings by carbon ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, L.J.; Sood, D.K.; Manory, R.R. [Royal Melbourne Inst. of Tech., VIC (Australia)

    1993-12-31

    Commercial TiN coatings of about 2 {mu}m thickness on high speed steel substrates were implanted at room temperature with 95 keV carbon ions at nominal doses between 1 x 10{sup 17} - 8x10{sup 17} ions cm{sup -2}. Carbon ion implantation induced a significant improvement in ultramicrohardness, friction coefficient and wear properties. The surface microhardness increases monotonically by up to 115% until a critical dose is reached. Beyond this dose the hardness decreases, but remains higher than that of unimplanted sample. A lower friction coefficient and a longer transition period towards a steady state condition were obtained by carbon ion implantation. The changes in tribomechanical properties are discussed in terms of radiation damage and possible formation of a second phase rich in carbon. 6 refs., 3 figs.

  16. Track structure based modelling of light ion radiation effects on nuclear and mitochondrial DNA

    Science.gov (United States)

    Schmitt, Elke; Ottolenghi, Andrea; Dingfelder, Michael; Friedland, Werner; Kundrat, Pavel; Baiocco, Giorgio

    2016-07-01

    Space radiation risk assessment is of great importance for manned spaceflights in order to estimate risks and to develop counter-measures to reduce them. Biophysical simulations with PARTRAC can help greatly to improve the understanding of initial biological response to ionizing radiation. Results from modelling radiation quality dependent DNA damage and repair mechanisms up to chromosomal aberrations (e.g. dicentrics) can be used to predict radiation effects depending on the kind of mixed radiation field exposure. Especially dicentric yields can serve as a biomarker for an increased risk due to radiation and hence as an indicator for the effectiveness of the used shielding. PARTRAC [1] is a multi-scale biophysical research MC code for track structure based initial DNA damage and damage response modelling. It integrates physics, radiochemistry, detailed nuclear DNA structure and molecular biology of DNA repair by NHEJ-pathway to assess radiation effects on cellular level [2]. Ongoing experiments with quasi-homogeneously distributed compared to sub-micrometre focused bunches of protons, lithium and carbon ions allow a separation of effects due to DNA damage complexity on nanometre scale from damage clustering on (sub-) micrometre scale [3, 4]. These data provide an unprecedented benchmark for the DNA damage response model in PARTRAC and help understand the mechanisms leading to cell killing and chromosomal aberrations (e.g. dicentrics) induction. A large part of space radiation is due to a mixed ion field of high energy protons and few heavier ions that can be only partly absorbed by the shielding. Radiation damage induced by low-energy ions significantly contributes to the high relative biological efficiency (RBE) of ion beams around Bragg peak regions. For slow light ions the physical cross section data basis in PARTRAC has been extended to investigate radiation quality effects in the Bragg peak region [5]. The resulting range and LET values agree with ICRU data

  17. 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.

  18. Funnel-type etched ion tracks in polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Vacík, Jiří; Hnatowicz, Vladimír; Munoz, G. H.; Alfonta, L.; Klinkovich, I.

    2010-01-01

    Roč. 165, č. 5 (2010), s. 343-361 ISSN 1042-0150 R&D Projects: GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z10480505 Keywords : tracks * polymers * etching Subject RIV: JJ - Other Materials Impact factor: 0.660, year: 2010

  19. Three kinds of high-energy Pb ion tracks on the LiF crystal surface at grazing angles of incidence

    CERN Document Server

    Vorobyova, I V

    2002-01-01

    Tracks induced on a surface of a LiF crystal by Pb ions with energy of 4.46 MeV/u were studied by the method of shadow replica electron microscopy. The irradiation was carried out at angles of 0.5 deg. and 2 deg. relative to the surface plane of the crystal. Lengths and widths of three kinds of tracks were compared: (1) surface tracks which are formed on a pure crystal surface; (2) island tracks which are formed in an island film of gold (with island radius and separation of <=5 nm) deposited on the crystal surface prior to irradiation and (3) island tracks which are formed in the same island film pressed against the crystal surface by the carbon layer. It was established: (1) At angle of irradiation of 0.5 deg. , the surface track formation is initiated at a point where the ion has not yet crossed the crystal surface, but rather moves above the surface plane at a distance of <=1 nm. (2) When the island track is formed in the free island film, the islands completely removed from the track zone. (3) When...

  20. Ion from Aqueous Solution using Magnetite, Activated Carbon

    African Journals Online (AJOL)

    ADOWIE PERE

    investigated using batch adsorption experiment at room temperature. The effects of initial metal ion concentration, contact time, adsorbent dosage, and temperature were evaluated. The activated carbon shows a structure like a honeycomb with a pattern of hollows and ridges, while the EDX shows an abundance of carbon.

  1. Simulation and dosimetric analysis of proton and carbon ion therapy in the treatment of uveal melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Christovao, Marilia Tavares, E-mail: marilia@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Campos, Tarcisio Passos Ribeiro de; Trindade, Bruno Machado [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2011-11-15

    The present paper addresses the dosimetric evaluation of carbon ion radiotherapy as compared with proton therapy. Materials and methods: computer simulations were undertaken with the Geant4 (GEometry ANd Tracking) code. An eye model discretized into voxels and implemented in the Siscodes system (computer system for dosimetry in radiation therapy) was utilized to generate and superimpose depth dose profiles and isodose curves. Different values for beam energy were adopted in the simulations of carbon ion beams, while in the simulation with proton beams irradiation line devices were included with different absorbing material thicknesses. Results: the simulations outputs were processed and integrated into the Siscodes to generate the spatial dose distribution in the eye model, considering changes in the beam entrance position. The dose rates were normalized as a function of the maximum dose for a beam at a specific entrance position, incident particle energy and number of incident carbon ions and protons. Conclusion: the described benefits together with the presented results contribute to the development of clinical applications and researches on carbon ion and proton therapy. (author)

  2. Strategies towards advanced ion track-based biosensors

    Czech Academy of Sciences Publication Activity Database

    Alfonta, L.; Bukelman, O.; Chandra, A.; Fahrner, W. R.; Fink, D.; Fuks, D.; Golovanov, V.; Hnatowicz, Vladimír; Hoppe, K.; Kiv, A.; Klinkovich, I.; Landau, M.; Morante, J.R.; Tkachenko, N.V.; Vacík, Jiří; Valden, M.

    2009-01-01

    Roč. 164, 7-8 (2009), s. 431-437 ISSN 1042-0150. [2nd International Meeting on Recent Developments in the Study of Radiation Effects in Matters. Fodele, 07.09.2008-11.09.2008] Institutional research plan: CEZ:AV0Z10480505 Keywords : biosensors * etched tracks * enzymes Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.550, year: 2009

  3. Artificial ion tracks in volcanic dark mica simulating natural radiation damage: A scanning force microscopy study

    International Nuclear Information System (INIS)

    Lang, M.; Glasmacher, U.A.; Moine, B.; Mueller, C.; Neumann, R.; Wagner, G.A.

    2002-01-01

    A new dating technique uses alpha-recoil tracks (ART), formed by the natural α-decay of U, Th and their daughter products, to determine the formation age of Quaternary volcanic rocks ( 6 a). Visualization of etched ART by scanning force microscopy (SFM) enables to access track densities beyond 10 8 cm -2 and thus extend the new ART-dating technique to an age range >10 6 a. In order to simulate natural radiation damage, samples of phlogopite, originating from Quaternary and Tertiary volcanic rocks of the Eifel (Germany) and Kerguelen Islands (Indian Ocean) were irradiated with U, Ni (11.4 MeV/u), Xe, Cr, Ne (1.4 MeV/u) and Bi (200 keV) ions. After irradiation and etching with HF at various etching times, phlogopite surfaces were visualized by SFM. Hexagonal etch pits are typical of U, Xe and Cr ion tracks, but the etch pits of Ni, Ne and Bi ion tracks are triangular. Surfaces irradiated with U, Xe, Cr and Ni ions do not show any significant difference between etch pit density and irradiation fluence, whereas the Ne-irradiated surface show ∼14 times less etch pit density. The etching rate v H (parallel to cleavage) depends on the chemical composition of the phlogopite. The etching rate v T ' (along the track) increases with energy loss

  4. ADSORPTION OF STRONTIUM IONS FROM WATER ON MODIFIED ACTIVATED CARBONS

    Directory of Open Access Journals (Sweden)

    Mihai Ciobanu

    2016-12-01

    Full Text Available Adsorption of strontium ions from aqueous solutions on active carbons CAN-7 and oxidized CAN-8 has been studied. It has been found that allure of the adsorption isotherms for both studied active carbons are practically identical. Studies have shown that the adsorption isotherms for strontium ions from aqueous solutions are well described by the Langmuir and Dubinin-Radushkevich equations, respectively. The surface heterogeneity of activated carbons CAN-7 and oxidized CAN-8 has been assessed by using Freundlich equation.

  5. Laser radiation effect on radiation-induced defects in heavy ion tracks in dielectrics

    International Nuclear Information System (INIS)

    Egorov, A.N.; Zhiryakov, B.M.; Kushin, V.V.; Lyapidevskij, V.K.; Khokhlov, N.B.

    1988-01-01

    Possibility of laser radiation resonance effect on radiation-induced defects in heavy ion tracks in dielectric materials is investigated. Absorption spectra in infrared, visible and ultraviolet ranges for cellulose nitrate samples irradiated by 6 MeV/nucleon 58 Ni ions and reactor gamma radiation are measured. Absorption spectra for irradiated and reference samples are presented. Two absorption bands λ 1 =0.33 μm (E 1 =3.9 eV) and λ 2 =0.72 μm (E 2 =1.7 eV) are detected. Etching rate decrease in a track under laser radiation effect is noticed. 3 refs.; 1 fig

  6. Comprehensive track-structure based evaluation of DNA damage by light ions from radiotherapy-relevant energies down to stopping

    Science.gov (United States)

    Friedland, W.; Schmitt, E.; Kundrát, P.; Dingfelder, M.; Baiocco, G.; Barbieri, S.; Ottolenghi, A.

    2017-01-01

    Track structures and resulting DNA damage in human cells have been simulated for hydrogen, helium, carbon, nitrogen, oxygen and neon ions with 0.25–256 MeV/u energy. The needed ion interaction cross sections have been scaled from those of hydrogen; Barkas scaling formula has been refined, extending its applicability down to about 10 keV/u, and validated against established stopping power data. Linear energy transfer (LET) has been scored from energy deposits in a cell nucleus; for very low-energy ions, it has been defined locally within thin slabs. The simulations show that protons and helium ions induce more DNA damage than heavier ions do at the same LET. With increasing LET, less DNA strand breaks are formed per unit dose, but due to their clustering the yields of double-strand breaks (DSB) increase, up to saturation around 300 keV/μm. Also individual DSB tend to cluster; DSB clusters peak around 500 keV/μm, while DSB multiplicities per cluster steadily increase with LET. Remarkably similar to patterns known from cell survival studies, LET-dependencies with pronounced maxima around 100–200 keV/μm occur on nanometre scale for sites that contain one or more DSB, and on micrometre scale for megabasepair-sized DNA fragments. PMID:28345622

  7. Carbon ion radiation therapy for high-risk meningiomas

    International Nuclear Information System (INIS)

    Combs, Stephanie E.; Hartmann, Christian; Nikoghosyan, Anna; Jaekel, Oliver; Karger, Christian P.; Haberer, Thomas; Deimling, Andreas von; Muenter, Marc W.; Huber, Peter E.; Debus, Juergen; Schulz-Ertner, Daniela

    2010-01-01

    Background: We analyzed outcome after a carbon ion boost in combination with precision photon radiation therapy in patients with meningiomas. Patients and methods: Ten patients with meningiomas were treated with carbon ion RT as part of a Phase I/II trial. Carbon ion RT was conducted in conjunction with fractionated stereotactic RT (FSRT) or intensity-modulated RT (IMRT). Eight patients were treated as primary RT, in 2 patients carbon ion RT was performed as re-irradiation. Carbon ion RT was applied with a median dose of 18 Gy E, and photon RT was applied with a median dose of 50.4 Gy. Two patients with a history of former irradiation received 18 Gy E of carbon ion RT and a reduced dose of photon treatment. Results: The median follow-up time was 77 months. Five patients died during follow-up, of which four died of tumor progression. In the group treated in the primary situation, actuarial survival rates after RT were 75% and 63% at 5 and 7 years. After re-irradiation, both patients died at 10 and 67 months, respectively. Actuarial local control rates after primary RT were 86% and 72% at 5 and 7 years. Two patients developed tumor recurrence after re-irradiation, 6 and 67 months after treatment. Conclusion: In conclusion, carbon ion radiation shows promising results in patients with atypical or anaplastic meningiomas. Further evaluation in a larger, prospective study in comparison to proton RT or modern photon RT is needed to corroborate these results.

  8. Evaluation of Additional Track Parameters from Fluorescent Nuclear Track Detectors to Determine the LET of Individual Ions.

    Science.gov (United States)

    Greilich, Steffen; Jansen, Jeannette; Neuholz, Alexander; Stadler, Alexander; Mescher, Henning; Klimpki, Grischa

    2017-10-27

    The measurement of single-track intensity in fluorescence nuclear track detectors can yield relative linear energy transfer (LET)-spectra with small line-width. The absolute determination of LET is, however, currently hampered by the inter-detector variability of crystal coloration and hence detector sensitivity. We therefore investigated the LET response of three additional quantities (average width and the variation of intensity and width along single tracks) using detectors irradiated with mono-energetic ion beams with LETs from 1.5 to 150 keV/μm in alumina. All quantities showed in fact smaller inter-detector variability, but at the same time larger line-width and limited dynamic range as the average intensity along a track. The additional quantities might therefore serve as a helpful complement, but not as a replacement for the current approach. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Detection and Investigation of Carbon Ions Induced by Nd:YAG laser using SSNTDs

    International Nuclear Information System (INIS)

    Qindeel, Rabia; Ali, Jalil Bin; Chaudhary, K. T.; Hussain, M. S.

    2011-01-01

    A Q-Switched Nd:YAG laser pulse of pulsed width of 9∼14 ns, wavelength of 1064 nm, repetition rate of 0.5 Hz, power of 1.1 MW and energy of 10 mJ has been used to ablate the 4N pure graphite target through IR lens. Solid state nuclear track detector (SSNTD) CR-39 has been used to calculate the energy of carbon ions produced as a result of laser ablation and the whole experiment has been performed under pressure ∼10 -3 Torr in stainless steel vacuum chamber. The minimum and maximum energy of carbon ions observed are 0.2 KeV to 250 KeV respectively.

  10. Ion conducting fluoropolymer carbonates for alkali metal ion batteries

    Science.gov (United States)

    DeSimone, Joseph M.; Pandya, Ashish; Wong, Dominica; Balsara, Nitash P.; Thelen, Jacob; Devaux, Didier

    2017-09-05

    Liquid or solid electrolyte compositions are described that comprise a homogeneous solvent system and an alkali metal salt dissolved in said solvent system. The solvent system may comprise a fluoropolymer, having one or two terminal carbonate groups covalently coupled thereto. Batteries containing such electrolyte compositions are also described.

  11. Secondary ion mass spectrometry combined with alpha track detection for isotope abundance ratio analysis of individual uranium-bearing particles.

    Science.gov (United States)

    Esaka, Fumitaka; Magara, Masaaki

    2014-03-01

    Secondary ion mass spectrometry (SIMS) was used in combination with alpha track detection for the efficient analysis of uranium-bearing particles with higher (235)U abundances in environmental samples. A polycarbonate film containing particles was prepared and placed in contact with a CR-39 plastic detector. After exposure for 28 days, the detector was etched in a NaOH solution and each uranium-bearing particle was identified through observation of the alpha tracks recorded in the detector. A portion of the film containing each uranium-bearing particle was cut out and put onto a glassy carbon planchet. The films on the planchet were decomposed through plasma ashing for subsequent uranium abundance ratio analysis with SIMS. The alpha track-SIMS analysis of 10 uranium-bearing particles in a sample taken from a nuclear facility enabled n((235)U)/n((238)U) abundance ratios in the range 0.0072-0.25 to be detected, which were significantly higher than those obtained by SIMS without alpha track detection. The duration of the whole analytical process for analysis of 10 particles was about 32 days. The detection efficiency was calculated to be 27.1±6.5%, based on the analysis of the particles in uranium reference materials. The detection limits, defined as the diameter of the particle which produces alpha tracks more than one for a 28-days exposure, were estimated to be 0.8, 0.9, 1.1, 2.1 and 3.0 μm for the particles having the same uranium abundance ratios with NBL CRM U850, U500, U350, U050 and U010 reference materials, respectively. The use of alpha track detection for subsequent SIMS analysis is an inexpensive and an efficient way to measure uranium-bearing particles with higher (235)U abundances. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Intense heavy ion beam-induced effects in carbon-based stripper foils

    Energy Technology Data Exchange (ETDEWEB)

    Kupka, Katharina

    2016-08-15

    -ray scattering (SAXS) were used. The changes of physical properties, in particular the electrical resistivity, thermal conductivity and stiffness of the foils were studied by in-situ 4-point probe, laser flash analysis and atomic force microscopy, respectively. A technique for measuring temperature of very thin, semitransparent and free-standing stripper foils during irradiation by means of an infrared (IR) camera was developed and applied. The experimental investigations were complemented by molecular dynamics simulations of amorphous carbon exposed to different swift heavy ions. The simulations provide information on the structural changes in the tracks at atomic scale. Virtual amorphous carbon cells were created by simulating liquid quenching and plasma deposition, yielding cells with different degrees of clustering of sp{sup 2} and sp{sup 3} bonding. The impacts of swift heavy ions were modeled by an instantaneous energy deposition deduced from inelastic thermal spike model calculations. Results of experiments and simulations provide evidence for the beam-induced transformation of amorphous carbon to a defected graphitic structure and for clustering of sp{sup 2} and sp{sup 3} bonds. These structural changes result in severe property changes. The electrical and thermal properties of amorphous carbon seem to improve during beam exposure, but the mechanical properties degrade severely. The beam conditions have a strong influence on the evolution of induced structure and property changes. A better understanding of the response of (amorphous) carbon stripper foils to swift heavy ion beams as revealed by dedicated irradiation and characterization experiments performed within this thesis, provides criteria for material requirements for future stripper foils used in high-power heavy ion accelerators such as FAIR.

  13. Intense heavy ion beam-induced effects in carbon-based stripper foils

    International Nuclear Information System (INIS)

    Kupka, Katharina

    2016-08-01

    -ray scattering (SAXS) were used. The changes of physical properties, in particular the electrical resistivity, thermal conductivity and stiffness of the foils were studied by in-situ 4-point probe, laser flash analysis and atomic force microscopy, respectively. A technique for measuring temperature of very thin, semitransparent and free-standing stripper foils during irradiation by means of an infrared (IR) camera was developed and applied. The experimental investigations were complemented by molecular dynamics simulations of amorphous carbon exposed to different swift heavy ions. The simulations provide information on the structural changes in the tracks at atomic scale. Virtual amorphous carbon cells were created by simulating liquid quenching and plasma deposition, yielding cells with different degrees of clustering of sp 2 and sp 3 bonding. The impacts of swift heavy ions were modeled by an instantaneous energy deposition deduced from inelastic thermal spike model calculations. Results of experiments and simulations provide evidence for the beam-induced transformation of amorphous carbon to a defected graphitic structure and for clustering of sp 2 and sp 3 bonds. These structural changes result in severe property changes. The electrical and thermal properties of amorphous carbon seem to improve during beam exposure, but the mechanical properties degrade severely. The beam conditions have a strong influence on the evolution of induced structure and property changes. A better understanding of the response of (amorphous) carbon stripper foils to swift heavy ion beams as revealed by dedicated irradiation and characterization experiments performed within this thesis, provides criteria for material requirements for future stripper foils used in high-power heavy ion accelerators such as FAIR.

  14. RBE and related modeling in carbon-ion therapy

    Science.gov (United States)

    Karger, Christian P.; Peschke, Peter

    2018-01-01

    Carbon ion therapy is a promising evolving modality in radiotherapy to treat tumors that are radioresistant against photon treatments. As carbon ions are more effective in normal and tumor tissue, the relative biological effectiveness (RBE) has to be calculated by bio-mathematical models and has to be considered in the dose prescription. This review (i) introduces the concept of the RBE and its most important determinants, (ii) describes the physical and biological causes of the increased RBE for carbon ions, (iii) summarizes available RBE measurements in vitro and in vivo, and (iv) describes the concepts of the clinically applied RBE models (mixed beam model, local effect model, and microdosimetric-kinetic model), and (v) the way they are introduced into clinical application as well as (vi) their status of experimental and clinical validation, and finally (vii) summarizes the current status of the use of the RBE concept in carbon ion therapy and points out clinically relevant conclusions as well as open questions. The RBE concept has proven to be a valuable concept for dose prescription in carbon ion radiotherapy, however, different centers use different RBE models and therefore care has to be taken when transferring results from one center to another. Experimental studies significantly improve the understanding of the dependencies and limitations of RBE models in clinical application. For the future, further studies investigating quantitatively the differential effects between normal tissues and tumors are needed accompanied by clinical studies on effectiveness and toxicity.

  15. Measurement of energy deposition near heavy ion tracks

    International Nuclear Information System (INIS)

    Metting, N.F.; Brady, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Wong, M.; Schimmerling, W.; Rapkin, M.

    1985-01-01

    In November of 1982 work was begun in collaboration with Columbia University and Lawrence Berkeley Laboratory to use microdosimetric methods to measure energy deposition of heavy ions produced at LBL's Bevalac Biomedical Facility. Last year the authors reported preliminary results indicating that secondary charged particle equilibrium was probably obtained using this experimental setup, but that there seemed to be poor spatial resolution in the solid state position-sensitive detector. Further analysis of the measurements taken in August 1983 shows that because of this electronic noise in the position-sensitive detector, only the 56 Fe data yielded useful microdosimetric spectra

  16. Influence of asymmetric etching on ion track shapes in polycarbonate

    International Nuclear Information System (INIS)

    Clochard, M.-C.; Wade, T.L.; Wegrowe, J.-E.; Balanzat, E.

    2007-01-01

    By combining low-energy ion irradiation with asymmetric etching, conical nanopores of controlled geometry can be etched in polycarbonate (PC). Cone bases vary from 0.5 to 1 μm. Top diameters down to 17 nm are reached. When etching from one side, the pH on the other side (bathed in neutral or acidic buffer) was monitored. Etching temperature ranged from 65 deg. C to 80 deg. C. Pore shape characterization was achieved by electro replication combined with SEM observation. The tip shape depended on whether an acidic buffer was used or not on the stopped side

  17. Amorphous track predictions in ‘libamtrack’ for alanine relative effectiveness in ion beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Greilich, Steffen; Grzanka, Leszek

    2011-01-01

    Solid state dosimetery in therapeutic ion beams is seriously hampered by ionisation density effects. In most cases the use of empirical corrections is limited and therefore model predictions, especially from amorphous track models (ATMs), play a major role. Due to its high saturation dose...

  18. Symphony and cacophony in ion track etching: how to control etching results

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Kiv, A.; Cruz, S. A.; Munoz, G. H.; Vacík, Jiří

    2012-01-01

    Roč. 167, č. 7 (2012), s. 527-540 ISSN 1042-0150 R&D Projects: GA AV ČR IAA200480702 Institutional support: RVO:61389005 Keywords : ion tracks * polymers * etching * diodes * resistances Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.502, year: 2012

  19. Investigation on heavy ion irradiation for producing nuclear track membrane at HI-13 tandem accelerator at CIAE

    International Nuclear Information System (INIS)

    Zhang Canzhe

    1997-10-01

    Some technical parameters and experimental results of heavy ion irradiation to produce nuclear track membrane at HI-13 tandem accelerator at CIAE are given, including the selection of heavy ions, the effect of energy and beam intensity on properties of nuclear track membrane, and the means for increasing irradiation uniformity. For production of nuclear track membrane, S ion beam with energy of 3.5∼4.5 MeV/N were used. The pore density and uniformity of nuclear track membrane produced at HI-13 Tandem Accelerator are 10 5 ∼10 8 cm -2 and ∼80% respectively. (9 refs., 4 figs., 1 tab.)

  20. Impact of time and space evolution of ion tracks in nonvolatile memory cells approaching nanoscale

    International Nuclear Information System (INIS)

    Cellere, G.; Paccagnella, A.; Murat, M.; Barak, J.; Akkerman, A.; Harboe-Sorensen, R.; Virtanen, A.; Visconti, A.; Bonanomi, M.

    2010-01-01

    Swift heavy ions impacting on matter lose energy through the creation of dense tracks of charges. The study of the space and time evolution of energy exchange allows understanding the single event effects behavior in advanced microelectronic devices. In particular, the shrinking of minimum feature size of most advanced memory devices makes them very interesting test vehicles to study these effects since the device and the track dimensions are comparable; hence, measured effects are directly correlated with the time and space evolution of the energy release. In this work we are studying the time and space evolution of ion tracks by using advanced non volatile memories and Monte Carlo simulations. Experimental results are very well explained by the theoretical calculations.

  1. Stoichiometric carbon nitride synthesized by ion beam sputtering and post nitrogen ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Valizadeh, R.; Colligon, J.S. [Salford Univ. (United Kingdom). DMM Institute; Katardiev, I.V. [Uppsala Univ. (Sweden). Angstrom Laboratory; Faunce, C.A.; Donnelly, S.E. [Salford Univ. (United Kingdom). Science Institute

    1998-06-01

    Full text: Carbon nitride films have been deposited on Si (100) by ion beam sputtering a vitreous graphite target with nitrogen and argon ions with and without concurrent N2 ion bombardment at room temperature. The sputtering beam energy was 1000 eV and the assisted beam energy was 300 eV with ion / atom arrival ratio ranging from 0.5 to 5. The carbon nitride films were deposited both as single layer directly on silicon substrate and as multilayer between two layers of stoichiometric amorphous silicon nitride and polycrystalline titanium nitride. The deposited films were implanted ex-situ with 30 keV nitrogen ions with various doses ranging from 1E17 to 4E17 ions.cm{sup -2} and 2 GeV xenon ion with a dose of 1E12 ions.cm{sup -2} . The nitrogen concentration of the films was measured with Rutherford Backscattering (RBS), Secondary Neutral Mass Spectrometry (SNMS) and Parallel Electron Energy Loss Spectroscopy (PEELS). The nitrogen concentration for as deposited sample was 34 at% and stoichiometric carbon nitride C{sub 3}N{sub 4} was achieved by post nitrogen implantation of the multi-layered films. Post bombardment of single layer carbon nitride films lead to reduction in the total nitrogen concentration. Carbon K edge structure obtained from PEELS analysis suggested that the amorphous C{sub 3}N{sub 4} matrix was predominantly sp{sup 2} bonded. This was confirmed by Fourier Transforrn Infra-Red Spectroscopy (FTIR) analysis of the single CN layer which showed the nitrogen was mostly bonded with carbon in nitrile (C{identical_to}N) and imine (C=N) groups. The microstructure of the film was determined by Transmission Electron Microscopy (TEM) which indicated that the films were amorphous.

  2. Ion-irradiation-induced defects in bundles of carbon nanotubes

    International Nuclear Information System (INIS)

    Salonen, E.; Krasheninnikov, A.V.; Nordlund, K.

    2002-01-01

    We study the structure and formation yields of atomic-scale defects produced by low-dose Ar ion irradiation in bundles of single-wall carbon nanotubes. For this, we employ empirical potential molecular dynamics and simulate ion impact events over an energy range of 100-1000 eV. We show that the most common defects produced at all energies are vacancies on nanotube walls, which at low temperatures are metastable but long-lived defects. We further calculate the spatial distribution of the defects, which proved to be highly non-uniform. We also show that ion irradiation gives rise to the formations of inter-tube covalent bonds mediated by carbon recoils and nanotube lattice distortions due to dangling bond saturation. The number of inter-tube links, as well as the overall damage, linearly grows with the energy of incident ions

  3. Damage threshold and structure of swift heavy ion tracks in Al2O3

    Science.gov (United States)

    Rymzhanov, R. A.; Medvedev, N.; Volkov, A. E.

    2017-11-01

    Structure changes and their formation threshold in swift heavy ion (SHI) tracks in Al2O3 are studied using a combined start-to-end numerical model. The hybrid approach consists of the Monte-Carlo code TREKIS, describing kinetics of the electronic subsystem, and classical Molecular Dynamics for lattice atoms. The developed approach is free from a posteriori fitting parameters. Simulations of Xe 167 MeV ion impacts show that relaxation of an excess lattice energy results in formation of a cylindrical discontinuous disordered region of about 2 nm in diameter. Recent transmission electron microscopy observations agree with these results. The threshold of an SHI track formation is estimated to be ~6.1 keV nm‑1. Calculated x-ray diffraction patterns of irradiated material demonstrate more pronounced damage of the Al atoms sublattice near SHI trajectories. Modeling of Xe ion tracks overlapping demonstrates that the damaged area can be restored to a near virgin state. Estimations give 6.5 nm as the minimal distance between the Xe ion trajectories resulting in recovery of the transformed structure produced by the previous ion.

  4. Retention of ion-implanted deuterium in tungsten pre-irradiated with carbon ions

    International Nuclear Information System (INIS)

    Alimov, V.Kh.; Ertl, K.; Roth, J.; Schmid, K.

    2000-01-01

    Deuterium (D) ion implantation and retention at room temperature was studied in pure and carbon (C) implanted tungsten single crystals. Pre-implantation with C was done at 40 keV and D implantation at 10 keV with the range confined in the carbon modified layer and at 100 keV with the range exceeding the carbon modified layer. The range distributions were investigated in situ using 1 MeV 3 He ions analysing the energy distributions of α particles from the D( 3 He,p)α reaction while the total amount of retained D was obtained from the p-integral. The range distribution of carbon was obtained from the backscattered 3 He energy distribution. C pre-impantation influences the D retention only if the range of the D ions is confined within the carbon modified surface layer. In this case, D diffusion beyond the ion range distribution does not occur and the retained D amount is smaller than in the pure W crystal. At D energies exceeding the carbon modified layer the retention occurs in the dislocation zone up to 1 μm and the total retained amount is the same for carbon implanted and pure W samples

  5. Adsorption dynamics of copper ion by low cost activated carbon

    International Nuclear Information System (INIS)

    Arivoli, S.; Saravanan, S.; Nandhakumar, V.; Nagarajan, Sulochana

    2009-01-01

    The activated carbon was prepared using solid waste called Terminalia Catappa Linn shell and the physicochemical properties of carbon were investigated to explore the adsorption process. The effectiveness of such carbon in adsorbing copper ion from aqueous solution has been studied as a function of agitation time, adsorbent dosage, initial metal ion concentration, temperature, pH, and desorption. Adsorption equilibrium studies were carried out in order to optimize the experimental conditions. The adsorption of copper ion onto carbon followed a first order kinetic model. Adsorption data were modeled using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity Qm was 30.60, 33.85, 35.87, and 38.35 at initial PH 7.0. The equilibrium time was found to be 40 min for all initial concentrations studied. Desorption studies were performed with dilute HCl and show that ion exchange is the predominant copper ion adsorption mechanism. The adsorbent was found to be both effective and economically viable. (author)

  6. A novel technique to estimate the track dimensions induced by heavy ions on UHMWPE

    International Nuclear Information System (INIS)

    Grosso, M.F. del; Chappa, V.C.; Garcia Bermudez, G.; Mazzei, R.O.

    2006-01-01

    The energy deposition of a heavy ion in a latent track gives rise to a central partially melting core zone surrounded by a larger region where some physico-chemical modifications take place. When these latent tracks start to overlap some interference effect occurs. A previous irradiated zone of one latent track can be eliminated by the core zone of others. In the present, work a Monte Carlo simulation program that permits us to determine the track dimensions is described. The core and chemical radii are obtained from fitting the FTIR absorption as a function of fluence. This new method was applied specifically on ultra-high molecular weight polyethylene (UHMWPE) irradiated with a 72 MeV S beam. The inner core radius value obtained was 5 ± 1 nm

  7. Application of ion beams for polymeric carbon based biomaterials

    Science.gov (United States)

    Evelyn, A. L.

    2001-07-01

    Ion beams have been shown to be quite suitable for the modification and analysis of carbon based biomaterials. Glassy polymeric carbon (GPC), made from cured phenolic resins, has a high chemical inertness that makes it useful as a biomaterial in medicine for drug delivery systems and for the manufacture of heart valves and other prosthetic devices. Low and high-energy ion beams have been used, with both partially and fully cured phenolic resins, to enhance biological cell/tissue growth on, and to increase tissue adhesion to GPC surfaces. Samples bombarded with energetic ion beams in the keV to MeV range exhibited increased surface roughness, measured using optical microscopy and atomic force microscopy. Ion beams were also used to perform nuclear reaction analyses of GPC encapsulated drugs for use in internal drug delivery systems. The results from the high energy bombardment were more dramatic and are shown in this paper. The interaction of energetic ions has demonstrated the useful application of ion beams to enhance the properties of carbon-based biomaterials.

  8. Tracking of Polycarbonate Films using Low-energy Ions Final Report CRADA No. TC-774-94

    Energy Technology Data Exchange (ETDEWEB)

    Musket, R. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2018-01-24

    Ion tracking is performed almost exclusively using ions with energies near or above the maximum in electronic stopping. For the present study, we have examined the results of etching ion tracks created by ions bombarding polycarbonate films with energies corresponding to stopping well below the maximum and just above the anticipated threshold for creating etchable latent tracks. Low-energy neon and argon ions with 18-60 keV /amu and fluences of about 108/cm2 were used to examine the limits for producing etchable tracks in polycarbonate films. By concentrating on the early stages of etching (i.e., -20 nm < SEM hole diameter < -100 nm), we can directly relate the energy deposition calculated for the incident ion to the creation of etchable tracks. The experimental results will be discussed with regard to the energy losses of the ions in the polycarbonate films and to the formation of continuous latent tracks through the entire thickness the films. These results have significant implications with respect to the threshold for formation of etchable tracks and to the use of low-energy ions for lithographic applications.

  9. Kinetics of Electrons from Plasma Discharge in a Latent Track Region Induced by Swift Heavy ION Irradiation

    Directory of Open Access Journals (Sweden)

    Minárik Stanislav

    2015-08-01

    Full Text Available While passing swift heavy ion through a material structure, it produces a region of radiation affected material which is known as a "latent track". Scattering motions of electrons interacting with a swift heavy ion are dominant in the latent track region. These phenomena include the electron impurity and phonon scattering processes modified by the interaction with the ion projectile as well as the Coulomb scattering between two electrons.

  10. Glass-like carbon, pyrolytic graphite or nanostructured carbon for electrochemical sensing of bismuth ion?

    Directory of Open Access Journals (Sweden)

    Jadranka Milikić

    2016-06-01

    Full Text Available Different carbon electrodes were explored for application in electroanalysis, namely for sensing of bismuth ion as model analyte. Carbon materials tested included glassy carbon, basal and edge plane pyrolytic graphite, as well as nanostructured carbonized polyaniline prepared in the presence of 3,5-dinitrosalicylic acid. Bismuth ion was chosen as model analyte as protocol for its detection and quantifications is still to be determined. Herein, anodic stripping voltammetry was used with study of effect of several parameters such as scan rate and deposition time. Electrode based on carbonized polyaniline showed the highest activity for bismuth ion sensing in terms of the highest current densities recorded both in a laboratory and in real sample, while basal plane pyrolytic graphite electrode gave the lowest limit of detection.

  11. Mutagenic effects of nitrogen and carbon ions on stevia

    International Nuclear Information System (INIS)

    Wang Cailian; Chen Qiufang; Shen Mei; Lu Ting; Shu Shizhen

    1998-06-01

    Dry seeds of stevia were implanted by 60∼100 keV nitrogen ion and 75 keV carbon ion with various doses. The biological effects in M 1 and mutation in M 2 were studied. The results showed that ion beam was able to induce variation on chromosome structure and inhibited mitosis action in root tip cells. The rate of cells with chromosome aberration was increased with the increase of ion beam energy and dose. Energy effects of mitosis were presented between 75 keV and 60, 100 keV. As compared with γ-rays, the effects of ion beam were lower on chromosomal aberration but were higher on frequency of the mutation. The rate of cell with chromosome aberration and M 2 useful mutation induced by implantation of carbon ion was higher than those induced by implantation of nitrogen ion. Mutagenic effects of Feng 1 x Ri Yuan and of Ri Yuan x Feng 2 are higher than that of Ji Ning and Feng 2

  12. Effect of valence holes kinetics on material excitation in tracks of swift heavy ions

    International Nuclear Information System (INIS)

    Rymzhanov, R.A.; Medvedev, N.A.; Volkov, A.E.

    2015-01-01

    A considerable part of the excess energy of the electronic subsystem of a solid penetrated by a swift heavy ion (SHI) is accumulated in valence holes. Spatial redistribution of these holes can affect subsequent relaxation, resulting in ionizations of new electrons by hole impacts as well as energy transfer to the target lattice. A new version of the Monte Carlo code TREKIS is applied to study this effect in Al 2 O 3 for SHI tracks. The complex dielectric function (CDF) formalism is used to calculate the cross sections of interaction of involved charged particles (an ion, electrons, holes) with the target giving us ability to take into account collective response of a target to excitations. We compare the radial distributions of the densities and energies of excited electrons and valence holes at different times to those obtained under the assumption of immobile holes used in earlier works. The comparison shows a significant difference between these distributions within the track core, where the majority of slow electrons and valence holes are located at femtosecond timescales after the ion impact. The study demonstrates that the energy deposited by valence holes into the lattice in nanometric tracks is comparable to the energy transferred by excited electrons. Radii of structure transformations in tracks produced by these energy exchange channels are in a good agreement with experiments.

  13. Adsorption studies of phosphate ions on alginate-calcium carbonate ...

    African Journals Online (AJOL)

    Alginate-calcium carbonate composite beads was prepared by the sol-gel method and characterized by Fourier transform infra-red spectroscopy (FT-IR) and scanning electron microscope (SEM) instruments. Adsorption potential of phosphate ions have been studied on laboratory scale. The effects of contact time, adsorbent ...

  14. Lead ions removal from aqueous solution using modified carbon ...

    Indian Academy of Sciences (India)

    2018-02-02

    Feb 2, 2018 ... Abstract. Surface-modified carbon nanotubes (CNTs) were prepared in order to remove lead ions (Pb2+) from aqueous solution. The modification of CNTs was conducted by oxidation, using a mixture of nitric acid (HNO3) and sulphuric acid. (H2SO4). The adsorption behaviour was well fitted to the ...

  15. Carbon Cryogel Silicon Composite Anode Materials for Lithium Ion Batteries

    Science.gov (United States)

    Woodworth James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 10 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-4,9 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  16. Study on LET distribution and dose distribution in heterogeneity for therapeutic carbon ion beams

    International Nuclear Information System (INIS)

    Kohno, Ryosuke; Yasuda, Nakahiro; Komori, Masataka; Matsufuji, Naruhiro; Kanematsu, Nobuyuki; Kanai, Tatsuaki; Himukai, Takeshi; Kase, Yuki; Ochiai, Keiko

    2005-01-01

    In order to develop and verify dose averaged linear energy transfer (LET) calculation algorithm for carbon ion radiotherapy, we used a CR-39 solid state track detector as an LET distribution detector. First, depth dose averaged LET distributions in water obtained using the CR-39 for mono-energetic beam and spread-out Bragg peak beam were compared with calculations by treatment planning. We confirmed that the CR-39 could measure the high LET particles which contribute dominantly to dose averaged LET. On the other hand, the CR-39 overestimated in tail region of distal fall-off in depth-dose distributions, since its detection limits for lower LET particles. However, as physical dose in the region is considerably small, effect of this discrepancy on the biological dose distribution turn out to be small. Therefore, we conclude that it is useful for LET distribution measurements in carbon ion radiotherapy to use the CR-39 detector. Then, we would like to modify into more precise carbon ion dose calculation algorithm to be able to predict lateral dose averaged LET distributions. Therefore, lateral dose averaged LET distributions for collimated beams were also measured using the CR-39 detectors and analyzed. (author)

  17. Ion Exclusion by Sub 2-nm Carbon Nanotube Pores

    Energy Technology Data Exchange (ETDEWEB)

    Fornasiero, F; Park, H G; Holt, J K; Stadermann, M; Grigoropoulos, C P; Noy, A; Bakajin, O

    2008-04-09

    Carbon nanotubes offer an outstanding platform for studying molecular transport at nanoscale, and have become promising materials for nanofluidics and membrane technology due to their unique combination of physical, chemical, mechanical, and electronic properties. In particular, both simulations and experiments have proved that fluid flow through carbon nanotubes of nanometer size diameter is exceptionally fast compared to what continuum hydrodynamic theories would predict when applied on this length scale, and also, compared to conventional membranes with pores of similar size, such as zeolites. For a variety of applications such as separation technology, molecular sensing, drug delivery, and biomimetics, selectivity is required together with fast flow. In particular, for water desalination, coupling the enhancement of the water flux with selective ion transport could drastically reduce the cost of brackish and seawater desalting. In this work, we study the ion selectivity of membranes made of aligned double-walled carbon nanotubes with sub-2 nm diameter. Negatively charged groups are introduced at the opening of the carbon nanotubes by oxygen plasma treatment. Reverse osmosis experiments coupled with capillary electrophoresis analysis of permeate and feed show significant anion and cation rejection. Ion exclusion declines by increasing ionic strength (concentration) of the feed and by lowering solution pH; also, the highest rejection is observed for the A{sub m}{sup Z{sub A}} C{sub n}{sup Z{sub C}} salts (A=anion, C=cation, z= valence) with the greatest Z{sub A}/Z{sub C} ratio. Our results strongly support a Donnan-type rejection mechanism, dominated by electrostatic interactions between fixed membrane charges and mobile ions, while steric and hydrodynamic effects appear to be less important. Comparison with commercial nanofiltration membranes for water softening reveals that our carbon nanotube membranes provides far superior water fluxes for similar ion

  18. IODA - a fast, automated and flexible system for ion track analysis on film detectors

    International Nuclear Information System (INIS)

    Guth, H.; Hellmann, A.

    1995-02-01

    The IODA System (Ion Density Analysis) is used to analyse detector films, resulting from experiments at the pulse power generator KALIF (Karlsruhe Light Ion Facility). The system consists of evaluation software and a microcomputer, which controls a microscope, a video interface, and a multiprocessor subsystem. The segmentation of ion tracks is done automatically by means of digital image processing and pattern recognition. After defining an evaluation range and selecting a suitable analysis method, the film is scanned by the microscope for counting the impacts of the underlying image. According to the appearance of the ion tracks on the film, different methods can be selected. The evaluation results representing the ion density are stored in a matrix. The time needed for an evaluation at a high resolution can be shortened by shipping time consuming pattern recognition calculations to the multiprocessor subsystem. The bottlenecks of the system are the data transfer and the speed of the microscope stage. Simple handling of the system even on alphanumeric terminals had been an important design issue. This was implemented by a logically structured menue system including online help features. This report can be used a s a manual to support the user with system operation. (orig.) [de

  19. Preliminary results of ion trajectory tracking in the acceleration region of the VINCY cyclotron

    Directory of Open Access Journals (Sweden)

    Ilić Anđelija Ž.

    2006-01-01

    Full Text Available In an accelerating region of a cyclotron, an ion makes a large number of turns; thus, its n the Runge-Kutta method of the fourth order with the adaptive time step has been developed. The accuracy requirement is simultaneously set on position and momentum calculation. Magnetic fields used as inputs, have been evaluated in terms of the radial fluctuations of the orbital frequency, i.e. their isochronisms. Ion trajectory tracking has been performed for the following four test beams: H-, H+3, 4He+, He+, and 40Ar6+.

  20. Track etching model for normal incident heavy ion recording in isotropic dielectric detectors

    International Nuclear Information System (INIS)

    Membrey, F.; Chambaudet, A.; Fromm, M.; Saouli, R.

    1990-01-01

    Heavy ion recording in dielectric isotropic detectors has a wide range of applications in such areas as uranium cartography, neutron activation and fission track dating using the external detector method (EDM). It is important to have a good understanding of etch pit evolution during chemical etching. The conical model, which is very often used, is based on a constant track etching velocity (VT). Numerous experiments have shown, however, that VT varies along the damage trail. In this paper, we propose a computer-generated model which simulates the etching process for normal incident ions. The analytical form of VT must be chosen in order to describe as precisely as possible the relationship between etching time (residual range) and the VT value. The conical model only provides a primary approximation which is generally insufficient, especially when performing cartography. (author)

  1. RBE of cells irradiated by carbon ions

    International Nuclear Information System (INIS)

    Li Wenjian; Zhou Guangming; Wei Zengquan; Wang Jufang; Dang Bingrong; Li Qiang; Xie Hongmei

    2002-01-01

    The mouse melanoma cells (B16), human cervical squamous carcinoma cells (HeLa), Chinese hamster pulmonary cells V79, and human hepatoma cells (SMMC-7721) were collected for studying. The cells of 5 x 10 5 /ml were seeded in 35 mm diameter petri dish and allowed to grow one day, and then the medium in petri dishes was removed away, the cells were washed once with phosphate-buffered saline (PBS), petri dishes was covered with 4μm thickness Mylar film. The cells were irradiated by 12 C ion beam with LETs of 125.5, 200, 700 keV/μm in water generated from HIRFL (Heavy Ion Research Facility in Lanzhou). For 60 Co γ-ray experiment, the cells of 5 x 10 4 /ml were grown in 20 ml culture flasks including 1.5 ml cell suspension and directly used for irradiation. Following irradiation, the cells were trypsinized, counted, plated at appropriate densities in growth medium and then seeded in 60 mm diameter culture dishes. Each dish was filled 4 ml standard medium, and incubated for 8-12 days at 37 degree C incubator containing 5% CO 2 . The cultures were then rinsed with PBS buffer at pH 6.8, fixed with Carnoy's fluid, stained for 8 min with Giemsa (1:20, pH 6.8), and colonies containing more than 50 cells were scored. Their relative biological effectivenesses (RBE) were investigated. The results show that RBE depends on cellular types and increases with increasing of cellular survival level when LET is at 125.5 keV/μm, and decreases with increasing LET when LET ≥ 125.5 keV/μm

  2. Induction of reproductive cell death in Caenorhabditis elegans across entire linear-energy-transfer range of carbon-ion irradiation.

    Science.gov (United States)

    Chen, Liangwen; Tang, Huangqi; Du, Yan; Dai, Zhangyu; Wang, Ting; Wu, Lijun; Zhou, Libin; Bian, Po

    2018-03-01

    Heavy-ion radiation has attracted extensive attention as an effective cancer therapy because of the varying energy deposition along its track and its high cell-killing effect. Reproductive cell death (RCD), also known as clonogenic death, is an important mode of death of the cancer cells after radiotherapy. Although RCD induced by heavy-ion irradiation with various linear energy transfers has been demonstrated using clonogenic assay in vitro, little is known about the distribution of RCD across the range of heavy-ion irradiation at the level of whole organisms. In this study, a vulval tissue model of Caenorhabditis elegans was for the first time used to assess RCD in vivo induced by carbon-ion irradiation. A polymethyl methacrylate wedge was designed to provide a gradually varying thickness of shielding, so worms could be exposed to the entire range of carbon-ion irradiation. The carbon-ion irradiation led to a significant induction of RCD over the entire range in a dose-dependent manner. The biological peak did not correspond to the physical Bragg peak and moved forward, rather than spread forward, as radiation dose increased. The degree and shape of the range-distribution of RCD were also affected by the developmental stages of the worms. The gene mutations in DNA-damage checkpoints did not affect the responses of mutant worms positioned in biological peaks, compared to wild-type worms, but decreased radio-sensitivity in the entrance region. An increased induction of RCD was observed in the worms impaired in homologous recombination (HR), but not in non-homologous end jointing pathway, suggesting a crucial role of HR repair in vulval cells of C. elegans in dealing with the carbon-ion-induced DNA damage. These unique manifestations of RCD in vivo in response to carbon-ion irradiation might provide new clues for further investigating the biological effects of heavy-ion irradiation. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Modification of polyacrylonitrile carbon fibers by highfluence ion irradiation

    Science.gov (United States)

    Andrianova, N. N.; Borisov, A. M.; Kazakov, V. A.; Mashkova, E. S.; Ovchinnikov, M. A.; Savushkina, S. V.; Chernenko, N. M.

    2017-12-01

    The Raman spectroscopy has been used to analyse ion-induced modifications of carbon PAN-fiber shell due to 10-30 keV Ar+ high fluence ion irradiation at normal and oblique incidence in the temperature range from RT to 400 °C. It has shown that formed in ion-induced processes of amorphization, recrystallization and crimping the modifications of PAN-fiber shell are characterized by the presence of the amorphous phase with the A peak in the Raman spectra and the increased intensity of the D peak relative to the G peak in comparison with non-irradiated fiber. Amorphous phase in the PAN-fiber shell is the highest in case of amorphization and the least at the crimping. The increased intensity of the D peak in the Raman spectra and the G peak shift towards higher frequencies during recrystallization and crimping indicates ion-induced nanostructuring of the PAN- fiber shell.

  4. Carbon nanowires generated by ion irradiation of hydrocarbon ices

    Energy Technology Data Exchange (ETDEWEB)

    Puglisi, O., E-mail: opuglisi@unict.it [Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, Catania 95125 (Italy); Compagnini, G.; D’Urso, L. [Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, Catania 95125 (Italy); Baratta, G.A.; Palumbo, M.E.; Strazzulla, G. [Istituto Nazionale di Astrofisica, Osservatorio Astrofisico di Catania, Via S. Sofia 78, Catania 95123 (Italy)

    2014-05-01

    In this paper we present the formation of carbon nanowires (polyynes and polycumulenes) in the solid state by ion irradiation of frozen hydrocarbons (C{sub 6}H{sub 6} and C{sub 2}H{sub 2}). Irradiations have been performed using H{sup +} ions in the 100’s keV energy regime using fluences up to 5 × 10{sup 14} ions/cm{sup 2}. Beyond the intrinsic significance of these results in the field of material science, this work has been motivated by the fact that ion beam irradiation of hydrocarbon ices is one of the most important process thought to happen in several extraterrestrial environments where many spectroscopic features of polyyne molecules have been identified.

  5. ION EXCHANGE PERFORMANCE OF TITANOSILICATES, GERMANATES AND CARBON NANOTUBES

    Energy Technology Data Exchange (ETDEWEB)

    Alsobrook, A. N.; Hobbs, D. T.

    2013-04-24

    This report presents a summary of testing the affinity of titanosilicates (TSP), germanium-substituted titanosilicates (Ge-TSP) and multiwall carbon nanotubes (MWCNT) for lanthanide ions in dilute nitric acid solution. The K-TSP ion exchanger exhibited the highest affinity for lanthanides in dilute nitric acid solutions. The Ge-TSP ion exchanger shows promise as a material with high affinity, but additional tests are needed to confirm the preliminary results. The MWCNT exhibited much lower affinities than the K-TSP in dilute nitric acid solutions. However, the MWCNT are much more chemically stable to concentrated nitric acid solutions and, therefore, may candidates for ion exchange in more concentrated nitric acid solutions. This technical report serves as the deliverable documenting completion of the FY13 research milestone, M4FT-13SR0303061 – measure actinide and lanthanide distribution values in nitric acid solutions with sodium and potassium titanosilicate materials.

  6. Development of C⁶⁺ laser ion source and RFQ linac for carbon ion radiotherapy.

    Science.gov (United States)

    Sako, T; Yamaguchi, A; Sato, K; Goto, A; Iwai, T; Nayuki, T; Nemoto, K; Kayama, T; Takeuchi, T

    2016-02-01

    A prototype C(6+) injector using a laser ion source has been developed for a compact synchrotron dedicated to carbon ion radiotherapy. The injector consists of a laser ion source and a 4-vane radio-frequency quadrupole (RFQ) linac. Ion beams are extracted from plasma and directly injected into the RFQ. A solenoid guides the low-energy beams into the RFQ. The RFQ is designed to accelerate high-intensity pulsed beams. A structure of monolithic vanes and cavities is adopted to reduce its power consumption. In beam acceleration tests, a solenoidal magnetic field set between the laser ion source and the RFQ helped increase both the peak currents before and after the RFQ by a factor of 4.

  7. Development of C6+ laser ion source and RFQ linac for carbon ion radiotherapy

    Science.gov (United States)

    Sako, T.; Yamaguchi, A.; Sato, K.; Goto, A.; Iwai, T.; Nayuki, T.; Nemoto, K.; Kayama, T.; Takeuchi, T.

    2016-02-01

    A prototype C6+ injector using a laser ion source has been developed for a compact synchrotron dedicated to carbon ion radiotherapy. The injector consists of a laser ion source and a 4-vane radio-frequency quadrupole (RFQ) linac. Ion beams are extracted from plasma and directly injected into the RFQ. A solenoid guides the low-energy beams into the RFQ. The RFQ is designed to accelerate high-intensity pulsed beams. A structure of monolithic vanes and cavities is adopted to reduce its power consumption. In beam acceleration tests, a solenoidal magnetic field set between the laser ion source and the RFQ helped increase both the peak currents before and after the RFQ by a factor of 4.

  8. Development of C6+ laser ion source and RFQ linac for carbon ion radiotherapy

    International Nuclear Information System (INIS)

    Sako, T.; Yamaguchi, A.; Sato, K.; Goto, A.; Iwai, T.; Nayuki, T.; Nemoto, K.; Kayama, T.; Takeuchi, T.

    2016-01-01

    A prototype C 6+ injector using a laser ion source has been developed for a compact synchrotron dedicated to carbon ion radiotherapy. The injector consists of a laser ion source and a 4-vane radio-frequency quadrupole (RFQ) linac. Ion beams are extracted from plasma and directly injected into the RFQ. A solenoid guides the low-energy beams into the RFQ. The RFQ is designed to accelerate high-intensity pulsed beams. A structure of monolithic vanes and cavities is adopted to reduce its power consumption. In beam acceleration tests, a solenoidal magnetic field set between the laser ion source and the RFQ helped increase both the peak currents before and after the RFQ by a factor of 4

  9. Multi-scale simulation of structural heterogeneity of swift-heavy ion tracks in complex oxides

    Science.gov (United States)

    Wang, Jianwei; Lang, Maik; Ewing, Rodney C.; Becker, Udo

    2013-04-01

    Tracks formed by swift-heavy ion irradiation, 2.2 GeV Au, of isometric Gd2Ti2O7 pyrochlore and orthorhombic Gd2TiO5 were modeled using the thermal-spike model combined with a molecular-dynamics simulation. The thermal-spike model was used to calculate the energy dissipation over time and space. Using the time, space, and energy profile generated from the thermal-spike model, the molecular-dynamics simulations were performed to model the atomic-scale evolution of the tracks. The advantage of the combination of these two methods, which uses the output from the continuum model as an input for the atomistic model, is that it provides a means of simulating the coupling of the electronic and atomic subsystems and provides simultaneously atomic-scale detail of the track structure and morphology. The simulated internal structure of the track consists of an amorphous core and a shell of disordered, but still periodic, domains. For Gd2Ti2O7, the shell region has a disordered pyrochlore with a defect fluorite structure and is relatively thick and heterogeneous with different degrees of disordering. For Gd2TiO5, the disordered region is relatively small as compared with Gd2Ti2O7. In the simulation, ‘facets’, which are surfaces with definite crystallographic orientations, are apparent around the amorphous core and more evident in Gd2TiO5 along [010] than [001], suggesting an orientational dependence of the radiation response. These results show that track formation is controlled by the coupling of several complex processes, involving different degrees of amorphization, disordering, and dynamic annealing. Each of the processes depends on the mass and energy of the energetic ion, the properties of the material, and its crystallographic orientation with respect to the incident ion beam.

  10. Registration threshold for tracks of 40Ar ions in muscovite mica

    International Nuclear Information System (INIS)

    Dwivedi, K.K.; Ghosh, S.; Raju, J.

    1993-01-01

    A simple technique has been described to measure both upper and lower energy registration threshold for tracks of 40 Ar ions in muscovite mica. The etchable portions of the damage trails were etched by an inter-layer (INLAY) etching procedure. The mean value of (dE/dx) c was found to be 15.5 ± 0.5 MeV.mg -1 .cm 2 . (Author)

  11. Investigation of Nuclear Fragmentation in Relativistic Heavy Ion Collisions Using Plastic - Nuclear - Track Detectors

    CERN Multimedia

    2002-01-01

    In this experiment CR39 plastic nuclear track detectors will be used which are sensitive to detect relativistic nuclear fragments with charges Z@$>$5. They will be analyzed using an automatic track measuring system which was developed at the University of Siegen.\\\\ \\\\ This allows to measure large quantities of tracks in these passive detectors and to perform high statistics experiments. We intend to measure cross sections for the production of nuclear fragments from heavy ion beams at the SPS. \\\\ \\\\ The energy independence of the cross sections predicted by the idea of limiting fragmentation will be tested at high energies. In exposures with different targets we plan to analyze the factorization of the fragmentation cross sections into a target depending factor and a factor depending on the beam particle and the fragment. The cross sections for one proton remov Coulomb dissociation. \\\\ \\\\ We plan to investigate Coulomb dissociation for different targets and different energies. Fragment and projectile charges ...

  12. Coprecipitation of alkali metal ions with calcium carbonate

    International Nuclear Information System (INIS)

    Okumura, Minoru; Kitano, Yasushi

    1986-01-01

    The coprecipitation of alkali metal ions Li + , Na + , K + and Rb + with calcium carbonate has been studied experimentally and the following results have been obtained: (1) Alkali metal ions are more easily coprecipitated with aragonite than with calcite. (2) The relationship between the amounts of alkali metal ions coprecipitated with aragonite and their ionic radii shows a parabolic curve with a peak located at Na + which has approximately the same ionic radius as Ca 2+ . (3) However, the amounts of alkali metal ions coprecipitated with calcite decrease with increasing ionic radius of alkali metals. (4) Our results support the hypothesis that (a) alkali metals are in interstitial positions in the crystal structure of calcite and do not substitute for Ca 2+ in the lattice, but (b) in aragonite, alkali metals substitute for Ca 2+ in the crystal structure. (5) Magnesium ions in the parent solution increase the amounts of alkali metal ions (Li + , Na + , K + and Rb + ) coprecipitated with calcite but decrease those with aragonite. (6) Sodium-bearing aragonite decreases the incorporation of other alkali metal ions (Li + , K + and Rb + ) into the aragonite. (author)

  13. Optical emission spectroscopy of carbon laser plasma ion source

    Science.gov (United States)

    Balki, Oguzhan; Rahman, Md. Mahmudur; Elsayed-Ali, Hani E.

    2018-04-01

    Carbon laser plasma generated by an Nd:YAG laser (wavelength 1064 nm, pulse width 7 ns, fluence 4-52 J cm-2) is studied by optical emission spectroscopy and ion time-of-flight. Up to C4+ ions are detected with the ion flux strongly dependent on the laser fluence. The increase in ion charge with the laser fluence is accompanied by observation of multicharged ion lines in the optical spectra. The time-integrated electron temperature Te is calculated from the Boltzmann plot using the C II lines at 392.0, 426.7, and 588.9 nm. Te is found to increase from ∼0.83 eV for a laser fluence of 22 J cm-2 to ∼0.90 eV for 40 J cm-2. The electron density ne is obtained from the Stark broadened profiles of the C II line at 392 nm and is found to increase from ∼ 2 . 1 × 1017cm-3 for 4 J cm-2 to ∼ 3 . 5 × 1017cm-3 for 40 J cm-2. Applying an external electric field parallel to the expanding plume shows no effect on the line emission intensities. Deconvolution of ion time-of-flight signal with a shifted Maxwell-Boltzmann distribution for each charge state results in an ion temperature Ti ∼4.7 and ∼6.0 eV for 20 and 36 J cm-2, respectively.

  14. Diffusion kinetics of the glucose/glucose oxidase system in swift heavy ion track-based biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Dietmar, E-mail: fink@xanum.uam.mx [Nuclear Physics Institute, 25068 Řež (Czech Republic); Departamento de Fisica, Universidad Autónoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 México, DF (Mexico); Vacik, Jiri; Hnatowicz, V. [Nuclear Physics Institute, 25068 Řež (Czech Republic); Muñoz Hernandez, G. [Departamento de Fisica, Universidad Autónoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 México, DF (Mexico); Garcia Arrelano, H. [Departamento de Ciencias Ambientales, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Lerma, Av. de las Garzas No. 10, Col. El Panteón, Lerma de Villada, Municipio de Lerma, Estado de México CP 52005 (Mexico); Alfonta, Lital [Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105 (Israel); Kiv, Arik [Department of Materials Engineering, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105 (Israel)

    2017-05-01

    Highlights: • Application of swift heavy ion tracks in biosensing. • Obtaining yet unknown diffusion coefficients of organic matter across etched ion tracks. • Obtaining diffusion coefficients of organics in etched ion tracks of biosensors. • Comparison with Renkin’s equation to predict the effective etched track diameter in the given experiments. - Abstract: For understanding of the diffusion kinetics and their optimization in swift heavy ion track-based biosensors, recently a diffusion simulation was performed. This simulation aimed at yielding the degree of enrichment of the enzymatic reaction products in the highly confined space of the etched ion tracks. A bunch of curves was obtained for the description of such sensors that depend only on the ratio of the diffusion coefficient of the products to that of the analyte within the tracks. As hitherto none of these two diffusion coefficients is accurately known, the present work was undertaken. The results of this paper allow one to quantify the previous simulation and hence yield realistic predictions of glucose-based biosensors. At this occasion, also the influence of the etched track radius on the diffusion coefficients was measured and compared with earlier prediction.

  15. WIMP detection and slow ion dynamics in carbon nanotube arrays

    CERN Document Server

    Cavoto, G.; Cocina, F.; Ferretti, J.; Polosa, A.D.

    2016-06-24

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (~ 10 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with ...

  16. Neon ion beam induced pattern formation on amorphous carbon surfaces

    Directory of Open Access Journals (Sweden)

    Omar Bobes

    2018-02-01

    Full Text Available We investigate the ripple pattern formation on amorphous carbon surfaces at room temperature during low energy Ne ion irradiation as a function of the ion incidence angle. Monte Carlo simulations of the curvature coefficients applied to the Bradley-Harper and Cater-Vishnyakov models, including the recent extensions by Harrison-Bradley and Hofsäss predict that pattern formation on amorphous carbon thin films should be possible for low energy Ne ions from 250 eV up to 1500 eV. Moreover, simulations are able to explain the absence of pattern formation in certain cases. Our experimental results are compared with prediction using current linear theoretical models and applying the crater function formalism, as well as Monte Carlo simulations to calculate curvature coefficients using the SDTrimSP program. Calculations indicate that no patterns should be generated up to 45° incidence angle if the dynamic behavior of the thickness of the ion irradiated layer introduced by Hofsäss is taken into account, while pattern formation most pronounced from 50° for ion energy between 250 eV and 1500 eV, which are in good agreement with our experimental data.

  17. Novel polysulphonates and poly(sulphonate-co-carbonate) polymers for nuclear track detection

    Energy Technology Data Exchange (ETDEWEB)

    Mandrekar, Vinod K.; Tilve, S.G. [Department of Chemistry, Goa University, Taliegao Plateau, Goa 403 206 (India); Nadkarni, V.S. [Department of Chemistry, Goa University, Taliegao Plateau, Goa 403 206 (India)], E-mail: nitin@unigoa.ac.in

    2008-09-15

    Preparation of homopolymer from diethylene glycol bis(allyl sulphonate) (DEAS) and its several copolymers with allyl diglycol carbonate (ADC) and their preliminary evaluation as nuclear track detector is described. The monomer is synthesized by reacting diethylene glycol with allyl sulphonyl chloride in presence of pyridine as a base. Spectral characteristics of the monomer are also given for the first time. The designed polymers were successfully tested for detection of {sup 239}Pu alpha particles and {sup 252}Cf fission fragment tracks after etching with 6 N NaOH at 70 deg. C. Some of the polymers prepared showed even better sensitivity than (SR-86)(20) track detectors for track detection properties. The polymers are also compared with commercial CR-39 track detectors for its track detection properties.

  18. Novel polysulphonates and poly(sulphonate-co-carbonate) polymers for nuclear track detection

    International Nuclear Information System (INIS)

    Mandrekar, Vinod K.; Tilve, S.G.; Nadkarni, V.S.

    2008-01-01

    Preparation of homopolymer from diethylene glycol bis(allyl sulphonate) (DEAS) and its several copolymers with allyl diglycol carbonate (ADC) and their preliminary evaluation as nuclear track detector is described. The monomer is synthesized by reacting diethylene glycol with allyl sulphonyl chloride in presence of pyridine as a base. Spectral characteristics of the monomer are also given for the first time. The designed polymers were successfully tested for detection of 239 Pu alpha particles and 252 Cf fission fragment tracks after etching with 6 N NaOH at 70 deg. C. Some of the polymers prepared showed even better sensitivity than (SR-86)(20) track detectors for track detection properties. The polymers are also compared with commercial CR-39 track detectors for its track detection properties

  19. Tracking Carbon along the Urban Watershed Continuum to Coastal Zones

    Science.gov (United States)

    Kaushal, S.

    2015-12-01

    Watersheds experiencing urbanization are constantly evolving in their structure and function, and their carbon cycle subsequently evolves across both space and time. We investigate how urbanization influences spatial and temporal evolution of the carbon cycle from small streams to major rivers in the Chesapeake Bay watershed using a variety of approaches such as stable isotopes, in situ water quality sensors, and remote sensing. Along the urban watershed continuum, we show that there is spatial evolution in: (1) the amount, chemical form, and reactivity of carbon, and (2) ecosystem metabolism and transformation of carbon sources from headwaters to coastal waters. Over shorter time scales, the interaction between land use and climate variability alters magnitude and sources of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) as revealed by stable isotopes and in situ sensors. Over longer time scales, land use change has altered particulate carbon transport in coastal waters and the evolution of river sediment plumes as suggested by remote sensing data. Furthermore, there are increased long-term bicarbonate alkalinity concentrations in streams and rivers, and we present new analytical approaches for studying river alkalinization due to human inputs and accelerated chemical weathering. In summary, urbanization alters carbon over space and time with major implications for downstream ecosystem metabolism, biological oxygen demand, carbon dioxide production, and river alkalinization.

  20. Bystander effects on mammalian cells induced by carbon ions

    International Nuclear Information System (INIS)

    Wang Jufang; Zhao Jing; Ma Qiufeng; Chinese Academy of Sciences, Beijing; Li Weijian; Zhou Guangming; Dang Bingrong; Mao Limin; Feng Yan

    2004-01-01

    Bystander effects on unirradiated V79 cells were observed by irradiated conditioned medium (ICM) method and co-cultured with carbon-ion-irradiated V79 cells. The results showed that the colony formation efficiency of unirradiated cells is obviously decreased by ICM. After co-culture with carbon-ion-irradiated cells for some time, the colony formation efficiency of co-cultured cells was lower than expected results assuming no bystander effects. The micronucleus frequency and hprt gene mutation rate was almost the same as expected results. Cytotoxic factor(s), which was effective for cell growth but not for micronucleus and mutation on unirradiated cells, might be released by irradiated cells. (authors)

  1. Natural variability in the surface ocean carbonate ion concentration

    OpenAIRE

    N. S. Lovenduski; M. C. Long; K. Lindsay

    2015-01-01

    We investigate variability in the surface ocean carbonate ion concentration ([CO32−]) on the basis of a long control simulation with a fully-coupled Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical...

  2. Natural variability in the surface ocean carbonate ion concentration

    OpenAIRE

    Lovenduski, N. S.; Long, M. C.; Lindsay, K.

    2015-01-01

    We investigate variability in the surface ocean carbonate ion concentration ([CO32−]) on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical Pacific and ...

  3. Water track distribution and effects on carbon dioxide flux in an eastern Siberian upland tundra landscape

    International Nuclear Information System (INIS)

    Curasi, Salvatore R; Loranty, Michael M; Natali, Susan M

    2016-01-01

    Shrub expansion in tundra ecosystems may act as a positive feedback to climate warming, the strength of which depends on its spatial extent. Recent studies have shown that shrub expansion is more likely to occur in areas with high soil moisture and nutrient availability, conditions typically found in sub-surface water channels known as water tracks. Water tracks are 5–15 m wide channels of subsurface water drainage in permafrost landscapes and are characterized by deeper seasonal thaw depth, warmer soil temperatures, and higher soil moisture and nutrient content relative to adjacent tundra. Consequently, enhanced vegetation productivity, and dominance by tall deciduous shrubs, are typical in water tracks. Quantifying the distribution of water tracks may inform investigations of the extent of shrub expansion and associated impacts on tundra ecosystem carbon cycling. Here, we quantify the distribution of water tracks and their contribution to growing season CO 2 dynamics for a Siberian tundra landscape using satellite observations, meteorological data, and field measurements. We find that water tracks occupy 7.4% of the 448 km 2 study area, and account for a slightly larger proportion of growing season carbon uptake relative to surrounding tundra. For areas inside water tracks dominated by shrubs, field observations revealed higher shrub biomass and higher ecosystem respiration and gross primary productivity relative to adjacent upland tundra. Conversely, a comparison of graminoid-dominated areas in water tracks and inter-track tundra revealed that water track locations dominated by graminoids had lower shrub biomass yet increased net uptake of CO 2 . Our results show water tracks are an important component of this landscape. Their distribution will influence ecosystem structural and functional responses to climate, and is therefore of importance for modeling. (letter)

  4. Equilibrium charge state distributions for boron and carbon ions emerging from carbon and aluminum targets

    International Nuclear Information System (INIS)

    Schmitt, Chris; LaVerne, Jay A.; Robertson, Daniel; Bowers, Matthew; Lu Wenting; Collon, Philippe

    2010-01-01

    Equilibrium charge state distributions of boron and carbon ions through carbon and aluminum targets were measured with an energy range of 3-6 MeV. Comparisons of the data with relevant semi-empirical models for the equilibrium mean charge states and for the charge state distribution widths could provide valuable insight on the underlying mechanisms for a fast ion to lose or capture electrons. In-depth examinations of the experimental results in combination with semi-empirical models suggest that equilibrium charge state distributions are well represented by Gaussian distributions.

  5. Surfactant-controlled etching of ion track nanopores and its practical applications in membrane technology

    International Nuclear Information System (INIS)

    Apel, P.Yu.; Blonskaya, I.V.; Dmitriev, S.N.; Mamonova, T.I.; Orelovitch, O.L.; Sartowska, B.; Yamauchi, Yu.

    2008-01-01

    The effect of surfactants on chemical development of ion tracks in polymers has been studied. It has been shown that surface-active agents added to an alkaline etching solution adsorb on the polymer surface at the pore entrances. This reduces the etch rate, which leads to the formation of pores tapered toward the surface. Self-assembly of surfactant molecules at the pore entrance creates a barrier for their penetration into the etched-out nanopores, whereas hydroxide ions diffuse freely. Due to this, the internal pore volume grows faster than the pore surface diameter. The ability to control pore shape is demonstrated with the fabrication of profiled nano- and micropores in polyethylene terephthalate, polycarbonate. Some earlier published data on small track-etched pores in polycarbonate (in particular, the pore diameter vs. etching time curves measured conductometrically) have been revised in light of the above findings. Adding surfactants to chemical etchants makes it possible to optimize the structure of track membranes, thus improving their retention and permeation properties. Asymmetric membranes with thin skin retention layers have been produced and their performance studied

  6. Surfactant-controlled etching of ion track nanopores and its practical applications in membrane technology

    Energy Technology Data Exchange (ETDEWEB)

    Apel, P.Yu. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)], E-mail: apel@nrmail.jinr.ru; Blonskaya, I.V.; Dmitriev, S.N.; Mamonova, T.I.; Orelovitch, O.L. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Sartowska, B. [Institute of Nuclear Chemistry and Technology, Dorodna Street 16, 03-195 Warsaw (Poland); Yamauchi, Yu. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

    2008-08-15

    The effect of surfactants on chemical development of ion tracks in polymers has been studied. It has been shown that surface-active agents added to an alkaline etching solution adsorb on the polymer surface at the pore entrances. This reduces the etch rate, which leads to the formation of pores tapered toward the surface. Self-assembly of surfactant molecules at the pore entrance creates a barrier for their penetration into the etched-out nanopores, whereas hydroxide ions diffuse freely. Due to this, the internal pore volume grows faster than the pore surface diameter. The ability to control pore shape is demonstrated with the fabrication of profiled nano- and micropores in polyethylene terephthalate, polycarbonate. Some earlier published data on small track-etched pores in polycarbonate (in particular, the pore diameter vs. etching time curves measured conductometrically) have been revised in light of the above findings. Adding surfactants to chemical etchants makes it possible to optimize the structure of track membranes, thus improving their retention and permeation properties. Asymmetric membranes with thin skin retention layers have been produced and their performance studied.

  7. Charge identification in CR-39 nuclear track detector using relativistic lead ion fragmentation

    CERN Document Server

    Manzoor, S; Rana, M A; Shahzad, M I; Sher, G; Sajid, M; Khan, H A; Giacomelli, G; Giorgini, M; Mandrioli, G; Patrizii, L; Popa, V; Serra, P; Togo, V

    2000-01-01

    Three stacks of plastic CR-39 Nuclear Track Detectors (NTD) were exposed to 158 A GeV /sup 207/Pb ions at the CERN-SPS beam facility. The main purpose of this experiment was the calibration of the CR-39 for the search of atmospheric magnetic monopoles. Different targets (Al, Cu and Pb) were used to produce a large spectrum of charge ions for the purpose of calibration as well as the study of ultrarelativistic lead ion fragmentation. The exposure of each stack was performed at normal incidence with a fluence of about 1500 ion/cm /sup 2/. The total number of lead ions in each spill was about 7.8*10 /sup 4/ and there were eight spills incident on each stack. For the stack with the Cu target, the lengths of etched cones on one face of the CR-39 were measured. From this measurement procedure, a new calibration curve has been generated for the extended charge region 63or=2, and a large dynamical range in counting rates of up to 10/sup 9/ s/sup -1/ due to single particle or current readout, respectively. (2 refs).

  8. Lithium ion battery peformance of silicon nanowires with carbon skin.

    Science.gov (United States)

    Bogart, Timothy D; Oka, Daichi; Lu, Xiaotang; Gu, Meng; Wang, Chongmin; Korgel, Brian A

    2014-01-28

    Silicon (Si) nanomaterials have emerged as a leading candidate for next generation lithium-ion battery anodes. However, the low electrical conductivity of Si requires the use of conductive additives in the anode film. Here we report a solution-based synthesis of Si nanowires with a conductive carbon skin. Without any conductive additive, the Si nanowire electrodes exhibited capacities of over 2000 mA h g(-1) for 100 cycles when cycled at C/10 and over 1200 mA h g(-1) when cycled more rapidly at 1C against Li metal. In situ transmission electron microscopy (TEM) observation reveals that the carbon skin performs dual roles: it speeds lithiation of the Si nanowires significantly, while also constraining the final volume expansion. The present work sheds light on ways to optimize lithium battery performance by smartly tailoring the nanostructure of composition of materials based on silicon and carbon.

  9. Effects of track structure and cell inactivation on the calculation of heavy ion mutation rates in mammalian cells

    Science.gov (United States)

    Cucinotta, F. A.; Wilson, J. W.; Shavers, M. R.; Katz, R.

    1996-01-01

    It has long been suggested that inactivation severely effects the probability of mutation by heavy ions in mammalian cells. Heavy ions have observed cross sections of inactivation that approach and sometimes exceed the geometric size of the cell nucleus in mammalian cells. In the track structure model of Katz the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated using the dose-response of the system to gamma-rays and the radial dose of the ions and may be equal to unity at small impact parameters for some ions. We show how the effects of inactivation may be taken into account in the evaluation of the mutation cross sections from heavy ions in the track structure model through correlation of sites for gene mutation and cell inactivation. The model is fit to available data for HPRT mutations in Chinese hamster cells and good agreement is found. The resulting calculations qualitatively show that mutation cross sections for heavy ions display minima at velocities where inactivation cross sections display maxima. Also, calculations show the high probability of mutation by relativistic heavy ions due to the radial extension of ions track from delta-rays in agreement with the microlesion concept. The effects of inactivation on mutations rates make it very unlikely that a single parameter such as LET or Z*2/beta(2) can be used to specify radiation quality for heavy ion bombardment.

  10. Metal carbonates as anode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Shao, Lianyi; Ma, Rui; Wu, Kaiqiang; Shui, Miao; Lao, Mengmeng; Wang, Dongjie; Long, Nengbing; Ren, Yuanlong; Shu, Jie

    2013-01-01

    Highlights: •Metal carbonates are probable anode materials for lithium ion batteries. •CoCO 3 /C composite can deliver an initial discharge capacity of 2096.6 mAh g −1 . •Co, Li 2 CO 3 , Li 2 O, and low-valence carbon are final lithiated products for CoCO 3 . -- Abstract: Six metal carbonates (Li 2 CO 3 , Na 2 CO 3 , SrCO 3 , BaCO 3 , K 2 CO 3 , CoCO 3 ) are tested and compared as anode materials for lithium ion batteries. The electrochemical results show that only CoCO 3 is electrochemically active material and can deliver a high initial capacity of 1425.9 mAh g −1 . The lithium storage mechanism in CoCO 3 is studied by ex situ X-ray diffraction technique, ex situ infrared method, ex situ X-ray photoelectron spectroscopy and in situ X-ray diffraction technique. It is found that the electrochemical reactions between CoCO 3 and Li firstly result in the formation of metal Co and Li 2 CO 3 , and then partial Li 2 CO 3 is further reduced into carbon (C 0 ), low-valence carbon (C 2+ ), and Li 2 O. It also demonstrates that the electrochemical reaction between CoCO 3 and Li is a partially reversible process. Based on these electrochemical results, it is obvious that narrow potential range can acquire a better reversibility for CoCO 3 /Li batteries by suppressing particle pulverization. Besides, the comparison of CoCO 3 , ball-milled CoCO 3 and ball-milled CoCO 3 /C composite also indicates that smaller active particle and carbon buffer are beneficial to obtain better cycling performance and higher reversible capacity

  11. X-ray photochemistry of carbon hydride molecular ions.

    Science.gov (United States)

    Puglisi, Alessandra; Miteva, Tsveta; Kennedy, Eugene T; Mosnier, Jean-Paul; Bizau, Jean-Marc; Cubaynes, Denis; Sisourat, Nicolas; Carniato, Stéphane

    2018-02-07

    Hydride molecular ions are key ingredients of the interstellar chemistry since they are precursors of more complex molecules. In regions located near a soft X-ray source these ions may resonantly absorb an X-ray photon which triggers a complex chain of reactions. In this work, we simulate ab initio the X-ray absorption spectrum, Auger decay processes and the subsequent fragmentation dynamics of two hydride molecular ions, namely CH 2 + and CH 3 + . We show that these ions feature strong X-ray absorption resonances which relax through Auger decay within 7 fs. The doubly-charged ions thus formed mostly dissociate into smaller ionic carbon fragments: in the case of CH 2 + , the dominant products are either C + /H + /H or CH + /H + . For CH 3 + , the system breaks primary into CH 2 + and H + , which provides a new route to form CH 2 + near a X-ray source. Furthermore, our simulations provide the branching ratios of the final products formed after the X-ray absorption as well as their kinetic and internal energy distributions. Such data can be used in the chemistry models of the interstellar medium.

  12. Development of a facility for high-precision irradiation of cells with carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Goethem, Marc-Jan van; Niemantsverdriet, Maarten; Brandenburg, Sytze; Langendijk, Johannes A.; Coppes, Robert P.; Luijk, Peter van [Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713AV Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands); Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747AA Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands); Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713AV Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands)

    2011-01-15

    the irradiation of cell samples with the specified accuracy. Measurements of the transverse and longitudinal dose distribution showed that the dose variation over the sample volume was {+-}0.8% and {+-}0.7% in the lateral and longitudinal directions, respectively. The track-averaged LET of 132{+-}10 keV/{mu}m and dose-averaged LET of 189{+-}15 keV/{mu}m at the position of the sample were obtained from a GEANT4 simulation, which was validated experimentally. Three separately measured cell-survival curves yielded nearly identical results. Conclusions: With the new facility, high-precision carbon-ion irradiations of biological samples can be performed with highly reproducible results.

  13. Synthesis of environmentally responsive organic materials by application of ion track holes in polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Omichi, Hideki; Yoshida, Masaru; Asano, Masaharu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Katakai, Ryoichi; Spohr, R.; Vetter, J.

    1997-03-01

    Polymer films were irradiated by heavy ion beams and etched by a concentrated alkali solution to produce particle track membranes (PTMs). Then the PTMs were chemically modified by grafting such monomers as amino acid group containing methacryloyl and N-isopropylacrylamide the polymers of which are known as environmentally responsive hydrogels. The size of pores of the modified PTMs under different temperatures in water was followed by electron microscopy. The pore was controlled from an open state to a completely closed state by changing temperature. The conductivity through the membrane was measured by changing the temperature of the cell. (author)

  14. Controlled Structure of Electrochemically Deposited Pd Nanowires in Ion-Track Templates

    Science.gov (United States)

    Duan, Jinglai; Lyu, Shuangbao; Yao, Huijun; Mo, Dan; Chen, Yonghui; Sun, Youmei; Maaz, K.; Maqbool, M.; Liu, Jie

    2015-12-01

    Understanding and controlling structural properties of the materials are crucial in materials research. In this paper, we report that crystallinity and crystallographic orientation of Pd nanowires can be tailored by varying the fabrication conditions during electrochemical deposition in polycarbonate ion-track templates. By changing the deposition temperature during the fabrication process, the nanowires with both single- and poly-crystallinities were obtained. The wires with preferred crystallographic orientations along [111], [100], and [110] directions were achieved via adjusting the applied voltage and temperature during electrochemical deposition.

  15. Ion track symmetric and asymmetric nanopores in polyethylene terephthalate foils for versatile applications

    Energy Technology Data Exchange (ETDEWEB)

    Apel, P.Yu., E-mail: apel@nrmail.jinr.ru [Flerov Laboratory of Nuclear Reactions, JINR, Joliot-Curie Str. 6, 141980 Dubna (Russian Federation); The International University “Dubna”, Universitetskaya Str. 19, Dubna 141980 (Russian Federation); Blonskaya, I.V.; Dmitriev, S.N.; Orelovich, O.L. [Flerov Laboratory of Nuclear Reactions, JINR, Joliot-Curie Str. 6, 141980 Dubna (Russian Federation); Sartowska, B.A. [Institute of Nuclear Chemistry and Technology, Dorodna Str. 16, 03-195 Warsaw (Poland)

    2015-12-15

    In this report we present several fabrication methods which allow production of ion track nanopore membranes with different pore configurations. Polymer foils, typically polyethylene terephthalate with a thickness of 5–23 μm, are irradiated with accelerated heavy ions (energy of 1–10 MeV/u) and then subjected to different physico-chemical treatments. Depending on the procedure, symmetric or asymmetric pores with nanoscale-sized narrowing are obtained. The asymmetric configurations include conical, funnel-like and bullet-like shapes. In electrolyte solutions the asymmetric nanopores exhibit diode-like properties which strongly depend on the pore shape. The peculiar features of such pores provide a basis for various applications.

  16. Silicon Composite Anode Materials for Lithium Ion Batteries Based on Carbon Cryogels and Carbon Paper

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nanofoams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  17. Carbon Cryogel and Carbon Paper-Based Silicon Composite Anode Materials for Lithium-Ion Batteries

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 6 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-5 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  18. Nanoparticle Traffic on Helical Tracks: Thermophoretic Mass Transport through Carbon Nanotubes

    DEFF Research Database (Denmark)

    Schoen, Philipp A.E.; Walther, Jens Honore; Arcidiacono, Salvatore

    2006-01-01

    Using molecular dynamics simulations, we demonstrate and quantify thermophoretic motion of solid gold nanoparticles inside carbon nanotubes subject to wall temperature gradients ranging from 0.4 to 25 K/nm. For temperature gradients below 1 K/nm, we find that the particles move "on tracks......" in a predictable fashion as they follow unique helical orbits depending on the geometry of the carbon nanotubes. These findings markedly advance our knowledge of mass transport mechanisms relevant to nanoscale applications....

  19. Hydrogenated carbon clusters produced by highly charged ion impact on solid C-84

    NARCIS (Netherlands)

    Schlatholter, T; Newman, MW; Niedermayr, TR; Machicoane, GA; McDonald, JW; Schenkel, T; Hoekstra, R; Hamza, AV

    2000-01-01

    The emission of small (hydrogenated) carbon cluster ions: CnHm+ (n = 2-22) upon highly charged Xeq+ (q = 20- 14) impact on C-84 surfaces is studied by means of time-of-flight secundary ion mass spectrometry. The respective stage of hydrogenation/protonation of a certain carbon cluster ion C-n(+) is

  20. Carbon nanotube/carbon nanotube composite AFM probes prepared using ion flux molding

    Science.gov (United States)

    Chesmore, Grace; Roque, Carrollyn; Barber, Richard

    The performance of carbon nanotube-carbon nanotube composite (CNT/CNT composite) atomic force microscopy (AFM) probes is compared to that of conventional Si probes in AFM tapping mode. The ion flux molding (IFM) process, aiming an ion beam at the CNT probe, aligns the tip to a desired angle. The result is a relatively rigid tip that is oriented to offset the cantilever angle. Scans using these probes reveal an improvement in image accuracy over conventional tips, while allowing higher aspect ratio imaging of 3D surface features. Furthermore, the lifetimes of CNT-CNT composite tips are observed to be longer than both conventional tips and those claimed for other CNT technologies. Novel applications include the imaging of embiid silk. Supported by the Clare Boothe Luce Research Scholars Award and Carbon Design Innovations.

  1. Bird specimens track 135 years of atmospheric black carbon and environmental policy

    Science.gov (United States)

    DuBay, Shane G.; Fuldner, Carl C.

    2017-10-01

    Atmospheric black carbon has long been recognized as a public health and environmental concern. More recently, black carbon has been identified as a major, ongoing contributor to anthropogenic climate change, thus making historical emission inventories of black carbon an essential tool for assessing past climate sensitivity and modeling future climate scenarios. Current estimates of black carbon emissions for the early industrial era have high uncertainty, however, because direct environmental sampling is sparse before the mid-1950s. Using photometric reflectance data of >1,300 bird specimens drawn from natural history collections, we track relative ambient concentrations of atmospheric black carbon between 1880 and 2015 within the US Manufacturing Belt, a region historically reliant on coal and dense with industry. Our data show that black carbon levels within the region peaked during the first decade of the 20th century. Following this peak, black carbon levels were positively correlated with coal consumption through midcentury, after which they decoupled, with black carbon concentrations declining as consumption continued to rise. The precipitous drop in atmospheric black carbon at midcentury reflects policies promoting burning efficiency and fuel transitions rather than regulating emissions alone. Our findings suggest that current emission inventories based on predictive modeling underestimate levels of atmospheric black carbon for the early industrial era, suggesting that the contribution of black carbon to past climate forcing may also be underestimated. These findings build toward a spatially dynamic emission inventory of black carbon based on direct environmental sampling.

  2. Molecular Ultrasound Imaging of Early Vascular Response in Prostate Tumors Irradiated with Carbon Ions

    Directory of Open Access Journals (Sweden)

    Moritz Palmowski

    2009-09-01

    Full Text Available Individualized treatments with combination of radiotherapy and targeted drugs require knowledge about the behavior of molecular targets after irradiation. Angiogenic marker expression has been studied after conventional radiotherapy, but little is known about marker response to charged particles. For the very first time, we used molecular ultrasound imaging to intraindividually track changes in angiogenic marker expression after carbon ion irradiation in experimental tumors. Expression of intercellular adhesion molecule-1 (ICAM-1 and of αvβ3-integrin in subcutaneous AT-1 prostate cancers in rats treated with carbon ions (16 Gy was studied using molecular ultrasound and immunohistochemistry. For this purpose, cyanoacrylate microbubbles were synthesized and linked to specific ligands. The accumulation of targeted microbubbles in tumors was quantified before and 36 hours after irradiation. In addition, tumor vascularization was analyzed using volumetric Doppler ultrasound. In tumors, the accumulation of targeted microbubbles was significantly higher than in nonspecific ones and could be inhibited competitively. Before irradiation, no difference in binding of αvβ3-integrin-specific or ICAM-1-specific microbubbles was observed in treated and untreated animals. After irradiation, however, treated animals showed a significantly higher binding of αvβ3-integrin-specific microbubbles and an enhanced binding of ICAM-1-specific microbubbles than untreated controls. In both groups, a decrease in vascularization occurred during tumor growth, but no significant difference was observed between irradiated and nonirradiated tumors. In conclusion, carbon ion irradiation upregulates ICAM-1 and αvβ3-integrin expression in tumor neovasculature. Molecular ultrasound can indicate the regulation of these markers and thus may help to identify the optimal drugs and time points in individualized therapy regimens.

  3. Crystallization of lysozyme in pores of etched heavy-ion tracks

    International Nuclear Information System (INIS)

    Dobrev, D.; Baur, D.; Neumann, R.

    2005-01-01

    Intensive studies of protein crystallization are provoked by the need to accumulate structural information and to open up novel potential applications in science and technology. This work focuses on the crystallization of hen egg white lysozyme (HEWL) in micrometer-size templates of etched swift-ion tracks produced in foils of polycarbonate, polyimide, and mica. HEWL deposition was accomplished by the salting with sodium chloride method at 20 and 6 C. The crystals overgrowing the pore orifices showed no orientation when crystallized at room temperature. At 6 C, they presented a regular habit and were uniaxially oriented on a polycarbonate substrate. Biaxial orientation was observed on polyimide membranes, and epitaxial orientation dominated on mica. However, no crystallization was observed on the mica membrane covered with a thin gold layer. The epitaxial growth of HEWL was particularly pronounced in the case of ordered substrates and low crystallization temperature, i.e. at higher supersaturation. By computer simulation it was possible to determine the surface lattice planes and thus provide the preferential crystal-growth orientation. Crystallization of lysozyme and other proteins in ion-track templates of submicrometer channels should be of high practical interest. (orig.)

  4. Protontherapy versus carbon ion therapy advantages, disadvantages and similarities

    CERN Document Server

    d’Ávila Nunes, Marcos

    2015-01-01

    This book presents a comparison analysis of two cancer treatment therapies: carbon ion therapy and protontherapy. It is divided in 5 sections. The first ones gives the reader a brief history of Radiotherapy and types of radiation. In the second section, the techniques and equipments, including new ones in development such as Cyclinac , Laser and DWA, are described. The third section describes biophysical (such as stopping power and LET) and biological (such as RBE and OER) properties, the fundamental experiments and clinical area. The fourth section presents models and the fifth section compares both techniques, showing advantages and disadvantages of each, and their similarities.

  5. Ion beam analysis of hydrogen retained in carbon nanotubes and carbon films

    International Nuclear Information System (INIS)

    McDaniel, F.D.; Holland, O.W.; Naab, F.U.; Mitchell, L.J.; Dhoubhadel, M.; Duggan, J.L.

    2006-01-01

    Carbon nanotubes (CNTs) are studied as a possible hydrogen storage medium for future energy needs. Typically, hydrogen is stored in the CNTs by exposure of the material to a high-pressure H 2 atmosphere at different temperatures. The maximum hydrogen concentrations stored following this method and measured using ion beam analysis do not exceed 1 wt.%. Introduction of defects by ion irradiation (i.e. implantation) prior to high-pressure H 2 treatment, offers an alternative method to activate H adsorption and enhance the chemisorption of hydrogen. This is a preliminary work where hydrogen was introduced into single-wall nanotubes and carbon films by low-energy (13.6 keV) hydrogen ion implantation. Elastic recoil detection was used to measure the quantity and depth distribution of hydrogen retained in the carbonaceous materials. Results show that there are substantial differences in the measured profiles between the CNT samples and the vitreous carbon. On another hand, only ∼43% of the implanted hydrogen in the CNTs is retained in the region where it should be located according to the SRIM simulations for a solid carbon sample

  6. Red mud carbonation using carbon dioxide: Effects of carbonate and calcium ions on goethite surface properties and settling.

    Science.gov (United States)

    Liang, Gaojie; Chen, Wenmi; Nguyen, Anh V; Nguyen, Tuan A H

    2018-05-01

    Carbonation using CO 2 appears as an attractive solution for disposing of red mud suspensions, an aluminum industry hazardous waste since it also offers an option for CO 2 sequestration. Here we report the novel findings that CO 3 2- together with Ca 2+ can significantly affect the surface properties and settling of goethite, a major component of red mud. Specifically, their effects on the goethite surface chemistry, colloidal interaction forces and settling in alkaline solutions are investigated. The surface potential becomes more negative by the formation of carbonate inner-sphere complexes on goethite surface. It is consistent with the strong repulsion, decreased particle size and settling velocity with increased carbonate concentrations as measured by atomic force microscopy, particle size analysis, and particle settling. Adding Ca 2+ that forms outer-sphere complexes with pre-adsorbed carbonate changes goethite surface charge negligibly. Changing repulsion to the attraction between goethite surfaces by increasing calcium dosage indicates the surface bridging, in accordance with the increased settling velocity. The adverse effect of carbonate on goethite flocculation is probably due to its specific chemisorption and competition with flocculants. By forming outer-sphere complexes together with the flocculant-calcium bridging effect, calcium ions can eliminate the negative influence of carbonate and improve the flocculation of goethite particles. These findings contribute to a better understanding of goethite particle interaction with salt ions and flocculants in controlling the particle behavior in the handling processes, including the red mud carbonation. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Study of carbon ion behavior by using collisional radiative model in the GAMMA 10 tandem mirror

    International Nuclear Information System (INIS)

    Kobayashi, Takayuki; Yoshikawa, Masayuki; Kubota, Yuusuke; Saito, Masashi; Matama, Ken; Itakura, Akiyoshi; Cho, Teruji; Kato, Takako

    2006-01-01

    In a plasma experiment, collisional radiative model (CRM) is very useful model to evaluate impurity behaviors and plasma parameters with line emission from a plasma. CRMs for carbon and oxygen have been developed. However verification and application of the model for analysis of experimental results are not enough. Then we applied CRM calculation results to observed impurity spectra in the GAMMA 10 tandem mirror to evaluate the impurity density profile and the particle balance of each charge state of carbon ion. We calculated the effective ionization rate for each charge state of carbon ion and obtained the density profile of each ion. Moreover, we calculated absolute emission intensities from all carbon ions. (author)

  8. Contributions of secondary fragmentation by carbon ion beams in water phantom: Monte Carlo simulation

    International Nuclear Information System (INIS)

    Ying, C K; Bolst, David; Tran, Linh T.; Guatelli, Susanna; Rosenfeld, A. B.; Kamil, W A

    2017-01-01

    Heavy-particle therapy such as carbon ion therapy is currently very popular because of its superior conformality in terms of dose distribution and higher Relative Biological Effectiveness (RBE). However, carbon ion beams produce a complex mixed radiation field, which needs to be fully characterised. In this study, the fragmentation of a 290 MeV/u primary carbon ion beam was studied using the Geant4 Monte Carlo Toolkit. When the primary carbon ion beam interacts with water, secondary light charged particles (H, He, Li, Be, B) and fast neutrons are produced, contributing to the dose, especially after the distal edge of the Bragg peak. (paper)

  9. Diffusion kinetics of the glucose/glucose oxidase system in swift heavy ion track-based biosensors

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Vacík, Jiří; Hnatowicz, Vladimír; Hernandez, G. M.; Arrelano, H. G.; Alfonta, L.; Kiv, A.

    2017-01-01

    Roč. 398, MAY (2017), s. 21-26 ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : etched ion tracks * track radius * polymer * enzyme * diffusion * biosensors Subject RIV: EI - Biotechnology ; Bionics OBOR OECD: Bioremediation, diagnostic biotechnologies (DNA chips and biosensing devices) in environmental management Impact factor: 1.109, year: 2016

  10. Large area diamond-like carbon coatings by ion implantation

    International Nuclear Information System (INIS)

    McCabe, A.R.; Proctor, G.; Jones, A.M.; Bull, S.J.; Chivers, D.J.

    1993-01-01

    Diamond-like Carbon (DLC) coatings have been deposited onto large geometry components in the Harwell Blue Tank ion implantation facility. To modify the substrate surface and to crack the low vapour pressure oil which is evaporated and condensed onto the surface, a 40 Kev nitrogen ion bucket ion source is used. The coating of areas up to 1 metre in diameter is common and with component manipulation larger areas may be coated. Since the component temperature never exceeds 80 o C during the process, a wide range of materials may be coated including specialist tool steels and even certain high density polymers. In order to produce hard wear resistant coatings with extremely low coefficients of friction (0.02-0.15) and a range of mechanical and electrical properties, various oil precursors have been investigated. The production and assessment of such coatings, including measurements of their tribiological performance, is presented. Applications for wear resistance, corrosion protection and electrically conducting coatings are discussed with examples drawn from engineering, electronics and biomedicine. (7 figures, 13 references). (UK)

  11. Nano mechanical properties of carbon films modified by ion radiation

    International Nuclear Information System (INIS)

    Foerster, C.E.; Serbena, F.C.; Lepienski, C.M.; Odo, G.Y.; Zawislak, F.C.; Lopes, J.M.J.; Baptista, D.L.; Garcia, I.T.S.

    2000-01-01

    In present work it is measured hardness, Young modulus and friction coefficient values for different types of carbon films. These films were submitted to different ion bombardment conditions (energy and fluencies). The mechanical behavior was obtained by nano indentation technique and analyzed by the Oliver/Pharr method. For friction coefficient determination the nano scratch procedure is used. Pristine C 60 films (fullerenes) has a hardness of 0.33 GPa. After irradiation with different ions (He, N and Bi), the hardness raise to about 14 GPa and the Young modulus change from 20 to about 200 GPa. For photoresist film AZ-1350J irradiation with Ar and He change the hardness from 0.4 to about 14 GPa and the Young modulus raise from 4 to 80 GPa. In a-C-H the hardness change from 3.5 to 11 GPa when submitted to N irradiation. In PPA films the hardness value raise from 0.5 to 11 GPa after irradiation with Ar. These mechanical and tribological results were analyzed in terms of deposited energy by the ion irradiation and compared with those presented in the literature. (author)

  12. CR-39 track detector calibration for H, He, and C ions from 0.1-0.5 MeV up to 5 MeV for laser-induced nuclear fusion product identification.

    Science.gov (United States)

    Baccou, C; Yahia, V; Depierreux, S; Neuville, C; Goyon, C; Consoli, F; De Angelis, R; Ducret, J E; Boutoux, G; Rafelski, J; Labaune, C

    2015-08-01

    Laser-accelerated ion beams can be used in many applications and, especially, to initiate nuclear reactions out of thermal equilibrium. We have experimentally studied aneutronic fusion reactions induced by protons accelerated by the Target Normal Sheath Acceleration mechanism, colliding with a boron target. Such experiments require a rigorous method to identify the reaction products (alpha particles) collected in detectors among a few other ion species such as protons or carbon ions, for example. CR-39 track detectors are widely used because they are mostly sensitive to ions and their efficiency is near 100%. We present a complete calibration of CR-39 track detector for protons, alpha particles, and carbon ions. We give measurements of their track diameters for energy ranging from hundreds of keV to a few MeV and for etching times between 1 and 8 h. We used these results to identify alpha particles in our experiments on proton-boron fusion reactions initiated by laser-accelerated protons. We show that their number clearly increases when the boron fuel is preformed in a plasma state.

  13. Method and apparatus for recovering uranium from a carbonate solution containing uranium ions

    International Nuclear Information System (INIS)

    Kunin, R.; Laterra, T.

    1982-01-01

    A process and apparatus for recovering uranium from a carbonate solution containing uranium ions whereby the carbonate solution containing uranium ions is brought in contact with a cation exchanger so that a uranium cation is removed from solution and absorbed by the cation exchanger, and the uranium cation is then removed from the cation exchanger. The treated carbonate solution from which uranium ions have been removed by cation exchange is then further processed by removing carbon dioxide from the treated carbonate solution to produce a decarbonated solution, and passing the decarbonated solution through a membrane process to remove some remaining impurities

  14. Strategy Selection of Film Irradiation by Accelerated ^{40}Ar^{8+} Ions for Manufacturing of Track Membranes

    CERN Document Server

    Denisov, Yu N; Kalinichenko, V V; Karamysheva, G A; Fedorenko, S B

    2004-01-01

    The industrial cyclotron CYTRACK is dedicated to the production of the track membranes. It is the basic instrument for the industry of membrane products to be consumed in medicine, biotechnology, pharmacology, microelectronics and many other industries. The cyclotron CYTRACK started working in the August of 2002. Argon ions were accelerated to a project energy of 2.4 MeV/nucleon, the extracted beam intensity was about 200 nA, the extraction efficiency totaled \\sim 50 %. In starting up operation the film was exposed in various controlled ways to charged particles with a view to achieving the values of parameters required for production of "Rosa" membranous plasmafilters. The pore uniformity in transverse direction was provided by beam scanning with a scanning magnet voltage of 73 V, the one in the longitudinal direction was provided by constancy of the film motion rate and stability of beam intensity during all the time of exposition.

  15. The co-effect of collagen and magnesium ions on calcium carbonate biomineralization

    International Nuclear Information System (INIS)

    Jiao Yunfeng; Feng Qingling; Li Xiaoming

    2006-01-01

    The process of calcium carbonate biomineralization in the solution containing collagen and magnesium ions was studied in this paper. The results were characterized by using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect rules were obtained by the cooperation of collagen and magnesium ions in different concentration. The experiment results showed that in the presence of both collagen and magnesium ions, aragonite and vaterite were precipitated at low Mg/Ca ion concentration ratio, while only aragonite with regular spherical morphology was precipitated at high Mg/Ca ion concentration ratio. It indicated that collagen has a promotional effect on magnesium ions in controlling the polymorph of calcium carbonate crystal. A much wider range of calcium carbonate morphologies was observed in the presence of both collagen and magnesium ions. The experiments suggested that collagen acts in combination with magnesium ions to inhibit calcite crystal growth, while favoring the formation of aragonite crystals

  16. Ionization of neon by intermediate energy carbon ions

    International Nuclear Information System (INIS)

    McLawhorn, S.L.; Toburen, L.H.; Shinpaugh, J.L.; Justiniano, E.L.B.; Dingfelder, M.; Toekesi, K.; Sulik, B.; Sigmund, P.; Schinner, A.; Reinhold, C.; Schultz, D.

    2007-01-01

    Complete text of publication follows. During the past few years there has been increasing interest in ionization of atomic and molecular targets by intermediate-energy dressed and partially dressed ions. These systems are particularly challenging to describe theoretically owing to screening of the projectile nuclear charge by bound electrons, interactions of projectile electrons with target electrons, and the large number of possible exit channels. At ECU we have initiated measurements of the doubly-differential ionization cross sections, differential in ejected electron energy and emission energy, for carbon ions of different initial charge states with atomic and molecular targets. In this presentation we compare those results with calculations being conducted at several institutions. For this presentation we will focus on electron emission from neon following interactions with carbon ions with energies from 0.067 MeV/u to 0.35 MeV/u and incident charge states from C + to C 3+ . Electron energies from 10 to 1500 eV are observed at emission angles from 20 to 120 degrees. The calculations separate the process into ionization of the target by the screened incident nucleus and the ionization of the target by the screened target nucleus. By summing these components in the rest frame of the target we can compare to the measured electron spectra. Figure 1 shows the single differential cross sections for ejection of electrons in C + -Ne collisions. Note the small contribution from ionization of the projectile. As the energy increases the contribution from projectile ionization increases; likewise as the ion energy decreases that contribution decreases. The excellent agreement shown in Figure 1 provides confidence to our use of Bohr theory for this energy range for this target. Doubly-differential cross sections based on the Classical Trajectory Monte Carlo (CTMC) techniques are compared with measurements in Fig. 2 for electron emission at 30 degrees. Again, excellent

  17. Anomalous effect of ion velocity on track formation in GeS

    Energy Technology Data Exchange (ETDEWEB)

    Szenes, G., E-mail: szenesgyorgy@caesar.elte.hu [Department of Materials Physics, Eötvös University, P.O. Box 32, H-1518 Budapest (Hungary); Pécz, B. [Institute for Technical Physics and Materials Science, Hungarian Academy of Sciences, 1525 Budapest, P.O. Box 49 (Hungary)

    2016-12-15

    Systematic experiments were performed for studying the effect of the projectile velocity (velocity effect, VE) in GeS which has a highly anisotropic conductivity. The prethinned specimens were irradiated by Bi, Au, W, Xe, Ag, Kr, Ni and Fe ions of about E ≈ 1 MeV/nucleon energy. Track radii were measured by transmission electron microscopy. Compared to previous experiments performed with high velocity projectile, there is a marked VE for S{sub e} > 20 keV/nm (S{sub e} – electronic stopping power). However, the VE is gradually reduced and finally disappears as S{sub e} decreases. This effect is described for the first time. The predictions according to the Analytical Thermal Spike Model are in excellent quantitative agreement with the experiments in the range S{sub e} > 20 keV/nm. The anomalous behavior of track evolution at lower values of S{sub e} is attributed to the combination of semiconducting and insulating properties. An explanation of the VE is given based on the Coulomb explosion model.

  18. Transport of Carbonate Ions by Novel Cellulose Fiber Supported Solid Membrane

    Directory of Open Access Journals (Sweden)

    A. G. Gaikwad

    2012-06-01

    Full Text Available Transport of carbonate ions was explored through fiber supported solid membrane. A novel fiber supported solid membrane was prepared by chemical modification of cellulose fiber with citric acid, 2′2-bipyridine and magnesium carbonate. The factors affecting the permeability of carbonate ions such as immobilization of citric acid-magnesium metal ion -2′2-bipyridine complex (0 to 2.5 mmol/g range over cellulose fiber, carbon-ate ion concentration in source phase and NaOH concentration in receiving phase were investigated. Ki-netic of carbonate, sulfate, and nitrate ions was investigated through fiber supported solid membrane. Transport of carbonate ions with/without bubbling of CO2 (0 to 10 ml/min in source phase was explored from source to receiving phase. The novel idea is to explore the adsorptive transport of CO2 from source to receiving phase through cellulose fiber containing magnesium metal ion organic framework. Copyright © 2012 BCREC UNDIP. All rights reserved.Received: 25th November 2011; Revised: 17th December 2011; Accepted: 19th December 2011[How to Cite: A.G. Gaikwad. (2012. Transport of Carbonate Ions by Novel Cellulose Fiber Supported Solid Membrane. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (1: 49– 57.  doi:10.9767/bcrec.7.1.1225.49-57][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.1.1225.49-57 ] | View in 

  19. A TPS kernel for calculating survival vs. depth: distributions in a carbon radiotherapy beam, based on Katz's cellular Track Structure Theory.

    Science.gov (United States)

    Waligórski, M P R; Grzanka, L; Korcyl, M; Olko, P

    2015-09-01

    An algorithm was developed of a treatment planning system (TPS) kernel for carbon radiotherapy in which Katz's Track Structure Theory of cellular survival (TST) is applied as its radiobiology component. The physical beam model is based on available tabularised data, prepared by Monte Carlo simulations of a set of pristine carbon beams of different input energies. An optimisation tool developed for this purpose is used to find the composition of pristine carbon beams of input energies and fluences which delivers a pre-selected depth-dose distribution profile over the spread-out Bragg peak (SOBP) region. Using an extrapolation algorithm, energy-fluence spectra of the primary carbon ions and of all their secondary fragments are obtained over regular steps of beam depths. To obtain survival vs. depth distributions, the TST calculation is applied to the energy-fluence spectra of the mixed field of primary ions and of their secondary products at the given beam depths. Katz's TST offers a unique analytical and quantitative prediction of cell survival in such mixed ion fields. By optimising the pristine beam composition to a published depth-dose profile over the SOBP region of a carbon beam and using TST model parameters representing the survival of CHO (Chinese Hamster Ovary) cells in vitro, it was possible to satisfactorily reproduce a published data set of CHO cell survival vs. depth measurements after carbon ion irradiation. The authors also show by a TST calculation that 'biological dose' is neither linear nor additive. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. A TPS kernel for calculating survival vs. depth: distributions in a carbon radiotherapy beam, based on Katz's cellular track structure theory

    International Nuclear Information System (INIS)

    Waligorski, M.P.R.; Grzanka, L.; Korcyl, M.; Olko, P.

    2015-01-01

    An algorithm was developed of a treatment planning system (TPS) kernel for carbon radiotherapy in which Katz's Track Structure Theory of cellular survival (TST) is applied as its radiobiology component. The physical beam model is based on available tabularised data, prepared by Monte Carlo simulations of a set of pristine carbon beams of different input energies. An optimisation tool developed for this purpose is used to find the composition of pristine carbon beams of input energies and fluences which delivers a pre-selected depth-dose distribution profile over the spread-out Bragg peak (SOBP) region. Using an extrapolation algorithm, energy-fluence spectra of the primary carbon ions and of all their secondary fragments are obtained over regular steps of beam depths. To obtain survival vs. depth distributions, the TST calculation is applied to the energy-fluence spectra of the mixed field of primary ions and of their secondary products at the given beam depths. Katz's TST offers a unique analytical and quantitative prediction of cell survival in such mixed ion fields. By optimising the pristine beam composition to a published depth-dose profile over the SOBP region of a carbon beam and using TST model parameters representing the survival of CHO (Chinese Hamster Ovary) cells in vitro, it was possible to satisfactorily reproduce a published data set of CHO cell survival vs. depth measurements after carbon ion irradiation. The authors also show by a TST calculation that 'biological dose' is neither linear nor additive. (authors)

  1. Measurements of energetic ions produced by high-energy laser pulses by means of solid-state nuclear track detectors

    Czech Academy of Sciences Publication Activity Database

    Szydlowski, A.; Badziak, A.; Parys, P.; Wolowski, J.; Woryna, E.; Jungwirth, Karel; Králiková, Božena; Krása, Josef; Láska, Leoš; Pfeifer, Miroslav; Rohlena, Karel; Skála, Jiří; Ullschmied, Jiří; Boody, F. D.; Gammino, S.; Torrisi, L.

    2004-01-01

    Roč. 7, č. 3 (2004), s. 327-332 ISSN 1093-3611 Institutional research plan: CEZ:AV0Z1010921 Keywords : iodine laser * nuclear track detectors * ions Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.194, year: 2004

  2. Imaging of carbon nanomembranes with helium ion microscopy

    Directory of Open Access Journals (Sweden)

    André Beyer

    2015-08-01

    Full Text Available Carbon nanomembranes (CNMs prepared from aromatic self-assembled monolayers constitute a recently developed class of 2D materials. They are made by a combination of self-assembly, radiation-induced cross-linking and the detachment of the cross-linked SAM from its substrate. CNMs can be deposited on arbitrary substrates, including holey and perforated ones, as well as on metallic (transmission electron microscopy grids. Therewith, freestanding membranes with a thickness of 1 nm and macroscopic lateral dimensions can be prepared. Although free-standing CNMs cannot be imaged by light microscopy, charged particle techniques can visualize them. However, CNMs are electrically insulating, which makes them sensitive to charging. We demonstrate that the helium ion microscope (HIM is a good candidate for imaging freestanding CNMs due to its efficient charge compensation tool. Scanning with a beam of helium ions while recording the emitted secondary electrons generates the HIM images. The advantages of HIM are high resolution, high surface sensitivity and large depth of field. The effects of sample charging, imaging of multilayer CNMs as well as imaging artefacts are discussed.

  3. Glass carbon surface modified by the fluorine ion irradiation

    International Nuclear Information System (INIS)

    Teranishi, Yoshikazu; Ishizuka, Masanori; Kobayashi, Tomohiro; Nakamura, Isao; Uematu, Takahiko; Yasuda, Takeshi; Mitsuo, Atsushi; Morikawa, Kazuo

    2012-01-01

    Application of nano and micro fabrication techniques in industry requires solution to some crucial problems. One of the significant problems is the sticking interface between mold surface and imprinted polymer. In this study, we report a solution to the sticking interface problem by modification of nano imprinting mold using fluorine ion implantation. After the fluorine implantation, anti sticking layer appeared on the nano imprinting mold surface. After the implantation, a mold made from glass like carbon was patterned by focused ion beam lithography. The pattern was made up of word “TIRI”. The line width was varied with 300 nm, 500 nm, and 1 μm. The line depth was about 200 ∼ 300 nm. The average depth of implanted fluorine was approximately 90 nm. After imprinting, the resin was removed from the mold by mechanical lift-off process. Transferred pattern was observed and confirmed by a scanning electron microscope (SEM) and an atomic force microscope (AFM). The pattern transferred from mold to resin was found to be successful.

  4. Visualization of complex DNA double-strand breaks in a tumor treated with carbon ion radiotherapy.

    Science.gov (United States)

    Oike, Takahiro; Niimi, Atsuko; Okonogi, Noriyuki; Murata, Kazutoshi; Matsumura, Akihiko; Noda, Shin-Ei; Kobayashi, Daijiro; Iwanaga, Mototaro; Tsuchida, Keisuke; Kanai, Tatsuaki; Ohno, Tatsuya; Shibata, Atsushi; Nakano, Takashi

    2016-03-01

    Carbon ion radiotherapy shows great potential as a cure for X-ray-resistant tumors. Basic research suggests that the strong cell-killing effect induced by carbon ions is based on their ability to cause complex DNA double-strand breaks (DSBs). However, evidence supporting the formation of complex DSBs in actual patients is lacking. Here, we used advanced high-resolution microscopy with deconvolution to show that complex DSBs are formed in a human tumor clinically treated with carbon ion radiotherapy, but not in a tumor treated with X-ray radiotherapy. Furthermore, analysis using a physics model suggested that the complexity of radiotherapy-induced DSBs is related to linear energy transfer, which is much higher for carbon ion beams than for X-rays. Visualization of complex DSBs in clinical specimens will help us to understand the anti-tumor effects of carbon ion radiotherapy.

  5. Physical and chemical response of 70 MeV carbon ion irradiated ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Physical and chemical responses of 70 MeV carbon ion irradiated Kapton-H polymer were studied by using UV-visible, FTIR and XRD techniques. The ion fluences ranging from 9⋅3 × 1011–9 × 1013 ions cm–2 were used. Recorded UV-visible spectra clearly showed a decrease in absorption initially with fluence, ...

  6. Generation of quasi-monoenergetic carbon ions accelerated parallel to the plane of a sandwich target

    Science.gov (United States)

    Wang, J. W.; Murakami, M.; Weng, S. M.; Xu, H.; Ju, J. J.; Luan, S. X.; Yu, W.

    2014-12-01

    A new ion acceleration scheme, namely, target parallel Coulomb acceleration, is proposed in which a carbon plate sandwiched between gold layers is irradiated with intense linearly polarized laser pulses. The high electrostatic field generated by the gold ions efficiently accelerates the embedded carbon ions parallel to the plane of the target. The ion beam is found to be collimated by the concave-shaped Coulomb potential. As a result, a quasi-monoenergetic and collimated C6+-ion beam with an energy exceeding 10 MeV/nucleon is produced at a laser intensity of 5 × 1019 W/cm2.

  7. Adsorption efficiencies of calcium (II ion and iron (II ion on activated carbon obtained from pericarp of rubber fruit

    Directory of Open Access Journals (Sweden)

    Orawan Sirichote

    2008-03-01

    Full Text Available Determination of adsorption efficiencies of activated carbon from pericarp of rubber fruit for calcium (II ion and iron (II ion has been performed by flowing the solutions of these ions through a column of activated carbon. The weights of activated carbon in 500 mL buret column (diameter 3.2 cm for flowing calcium (II ion and iron (II ion solutions were 15 g and 10 g, respectively. The initial concentration of calcium ion was prepared to be about eight times more diluted than the true concentration found in the groundwater from the lower part of southern Thailand. Calcium (II ion concentrations were analysed by EDTA titration and its initial concentration was found to be 23.55 ppm. With a flow rate of 26 mL/min, the adsorption efficiency was 11.4 % with passed through volume 4.75 L. Iron (II ion concentrations were analysed by spectrophotometric method; its initial concentration was found to be 1.5565 ppm. At a flow rate of 22 mL/min, the adsorption efficiency was 0.42 % with passed through volume of 34.0 L.

  8. Mouse skin damages caused by fractionated irradiation with carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Ando, K.; Chen, Y.J.; Ohira, C.; Nojima, K.; Ando, S.; Kobayashi, N.; Ohbuchi, T.; Shimizu, W. [Space and Particle Radiation Science Research Group, Chiba (Japan); Koike, S.; Kanai, T. [National Inst. of Radiological Sciences, Chiba (Japan). Div. of Accelerator Physics

    1997-09-01

    We have investigated carbon-dose responses of early and late skin damages after daily fractionations to the mouse leg. Depilated legs were irradiated with 7 different positions within 290 MeV/u carbon beams. Fractionation schedules were 1, 2, 4 and 8 daily fractions. Skin reaction was scored every other day for 32 days. Five highest scores in individual mice were averaged, and used as averaged peak reaction. The isoeffect doses to produce an averaged peak skin reaction of 3.0 (moist desquamation) on dose-response curves were calculated with 95% confidence limit. The isoeffect dose for control gamma rays constantly increased with an increase in the number of fraction. The isoeffect doses in low LET carbon ions of 14- and 20 keV/{mu}m also increased up to 4 fractions, but did not increase when 4 fractions increased to 8 fractions. The saturation of isoeffect dose was more prominently observed for 40 keV/{mu}m in such that the isoeffect doses did not change among 2, 4 and 8 fractions. The isoeffect doses for LET higher than 50 keV/{mu}m were smaller than those for lower LET. However, the isoeffect doses for 50-, 60-, 80- and 100 keV/{mu} steadily increased with an increase in the number of fraction and did not show any saturation up to 8 fractions. Relation between LET and RBE was linear for all fractionation schedules. The slope of regression line in 4 fractions was steepest, and significantly (P<0.05) different from that in 1 fraction. (orig.)

  9. Mouse skin damages caused by fractionated irradiation with carbon ions

    International Nuclear Information System (INIS)

    Ando, K.; Chen, Y.J.; Ohira, C.; Nojima, K.; Ando, S.; Kobayashi, N.; Ohbuchi, T.; Shimizu, W.; Koike, S.; Kanai, T.

    1997-01-01

    We have investigated carbon-dose responses of early and late skin damages after daily fractionations to the mouse leg. Depilated legs were irradiated with 7 different positions within 290 MeV/u carbon beams. Fractionation schedules were 1, 2, 4 and 8 daily fractions. Skin reaction was scored every other day for 32 days. Five highest scores in individual mice were averaged, and used as averaged peak reaction. The isoeffect doses to produce an averaged peak skin reaction of 3.0 (moist desquamation) on dose-response curves were calculated with 95% confidence limit. The isoeffect dose for control gamma rays constantly increased with an increase in the number of fraction. The isoeffect doses in low LET carbon ions of 14- and 20 keV/μm also increased up to 4 fractions, but did not increase when 4 fractions increased to 8 fractions. The saturation of isoeffect dose was more prominently observed for 40 keV/μm in such that the isoeffect doses did not change among 2, 4 and 8 fractions. The isoeffect doses for LET higher than 50 keV/μm were smaller than those for lower LET. However, the isoeffect doses for 50-, 60-, 80- and 100 keV/μ steadily increased with an increase in the number of fraction and did not show any saturation up to 8 fractions. Relation between LET and RBE was linear for all fractionation schedules. The slope of regression line in 4 fractions was steepest, and significantly (P<0.05) different from that in 1 fraction. (orig.)

  10. Natural variability in the surface ocean carbonate ion concentration

    Directory of Open Access Journals (Sweden)

    N. S. Lovenduski

    2015-11-01

    Full Text Available We investigate variability in the surface ocean carbonate ion concentration ([CO32−] on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical Pacific and at the boundaries between the subtropical and subpolar gyres in the Northern Hemisphere, and relatively low interannual variability in the centers of the subtropical gyres and in the Southern Ocean. Statistical analysis of modeled [CO32−] variance and autocorrelation suggests that significant anthropogenic trends in the saturation state of aragonite (Ωaragonite are already or nearly detectable at the sustained, open-ocean time series sites, whereas several decades of observations are required to detect anthropogenic trends in Ωaragonite in the tropical Pacific, North Pacific, and North Atlantic. The detection timescale for anthropogenic trends in pH is shorter than that for Ωaragonite, due to smaller noise-to-signal ratios and lower autocorrelation in pH. In the tropical Pacific, the leading mode of surface [CO32−] variability is primarily driven by variations in the vertical advection of dissolved inorganic carbon (DIC in association with El Niño–Southern Oscillation. In the North Pacific, surface [CO32−] variability is caused by circulation-driven variations in surface DIC and strongly correlated with the Pacific Decadal Oscillation, with peak spectral power at 20–30-year periods. North Atlantic [CO32−] variability is also driven by variations in surface DIC, and exhibits weak correlations with both the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. As the scientific community seeks to detect the anthropogenic influence on ocean carbonate chemistry, these results

  11. Natural variability in the surface ocean carbonate ion concentration

    Science.gov (United States)

    Lovenduski, N. S.; Long, M. C.; Lindsay, K.

    2015-11-01

    We investigate variability in the surface ocean carbonate ion concentration ([CO32-]) on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32-] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32-] in the tropical Pacific and at the boundaries between the subtropical and subpolar gyres in the Northern Hemisphere, and relatively low interannual variability in the centers of the subtropical gyres and in the Southern Ocean. Statistical analysis of modeled [CO32-] variance and autocorrelation suggests that significant anthropogenic trends in the saturation state of aragonite (Ωaragonite) are already or nearly detectable at the sustained, open-ocean time series sites, whereas several decades of observations are required to detect anthropogenic trends in Ωaragonite in the tropical Pacific, North Pacific, and North Atlantic. The detection timescale for anthropogenic trends in pH is shorter than that for Ωaragonite, due to smaller noise-to-signal ratios and lower autocorrelation in pH. In the tropical Pacific, the leading mode of surface [CO32-] variability is primarily driven by variations in the vertical advection of dissolved inorganic carbon (DIC) in association with El Niño-Southern Oscillation. In the North Pacific, surface [CO32-] variability is caused by circulation-driven variations in surface DIC and strongly correlated with the Pacific Decadal Oscillation, with peak spectral power at 20-30-year periods. North Atlantic [CO32-] variability is also driven by variations in surface DIC, and exhibits weak correlations with both the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. As the scientific community seeks to detect the anthropogenic influence on ocean carbonate chemistry, these results will aid the interpretation of trends

  12. Novel high sensitivity poly (sulphonate-carbonate) nuclear track detector-I: poly (PECS-co-ADC)

    International Nuclear Information System (INIS)

    Mandrekar, V.K.; Kotkar, S.M.; Tilve, S.G.; Nadkarni, V.S.

    2009-01-01

    The paper describes synthesis of a novel monomer Pentaerythritol bis (allyl carbonate)bis (allyl sulphonate) (PECS) and its cast copolymerization with Allyl Diglycol Carbonate (ADC) monomer for use as solid state nuclear track detector (SSNTD). The polymer obtained was successfully used to reveal 239 Pu alpha and 252 Cf fission fragment tracks. The polymer could be conveniently etched using 6N NaOH at 70 deg C. (author)

  13. Na-ion capacitor using sodium pre-doped hard carbon and activated carbon

    International Nuclear Information System (INIS)

    Kuratani, Kentaro; Yao, Masaru; Senoh, Hiroshi; Takeichi, Nobuhiko; Sakai, Tetsuo; Kiyobayashi, Tetsu

    2012-01-01

    We assembled a sodium-ion capacitor (Na-IC) by combining sodium pre-doped hard carbon (HC) as the negative- and activated carbon (AC) as the positive-electrode. The electrochemical properties were compared with two lithium-ion capacitors (Li-ICs) in which the negative electrodes were prepared with Li pre-doped HC and mesocarbon microbeads (MCMB). The positive and negative electrodes were prepared using the established doctor blade method. The negative electrodes were galvanostatically pre-doped with Na or Li to 80% of the full capacity of carbons. The potential of the negative electrodes after pre-doping was around 0.0 V vs. Na/Na + or Li/Li + , which resulted in the higher output potential difference of the Na-IC and Li-ICs than that of the conventional electrochemical double-layer capacitors (EDLCs) because AC positive electrode works in the same principle both in the ion capacitors and in the EDLC. The state-of-charge of the negative electrode varied 80 ± 10% during the electrochemical charging and discharging. The capacity of the cell was evaluated using galvanostatic charge–discharge measurement. At the discharge current density of 10 mA cm −2 , the Na-IC maintained 70% of the capacity that obtained at the current density of 0.5 mA cm −2 , which was comparable to the Li-ICs. At 50 mA cm −2 , the capacities of the Li-IC(MCMB) and the Na-IC dropped to 20% whereas the Li-IC(HC) retained 30% of the capacity observed at 0.5 mA cm −2 . The capacities of the Na-IC and Li-ICs decreased by 9% and 3%, respectively, after 1000 cycles of charging and discharging.

  14. Method for fabricating carbon/lithium-ion electrode for rechargeable lithium cell

    Science.gov (United States)

    Huang, Chen-Kuo (Inventor); Surampudi, Subbarao (Inventor); Attia, Alan I. (Inventor); Halpert, Gerald (Inventor)

    1995-01-01

    The method includes steps for forming a carbon electrode composed of graphitic carbon particles adhered by an ethylene propylene diene monomer binder. An effective binder composition is disclosed for achieving a carbon electrode capable of subsequent intercalation by lithium ions. The method also includes steps for reacting the carbon electrode with lithium ions to incorporate lithium ions into graphitic carbon particles of the electrode. An electrical current is repeatedly applied to the carbon electrode to initially cause a surface reaction between the lithium ions and to the carbon and subsequently cause intercalation of the lithium ions into crystalline layers of the graphitic carbon particles. With repeated application of the electrical current, intercalation is achieved to near a theoretical maximum. Two differing multi-stage intercalation processes are disclosed. In the first, a fixed current is reapplied. In the second, a high current is initially applied, followed by a single subsequent lower current stage. Resulting carbon/lithium-ion electrodes are well suited for use as an anode in a reversible, ambient temperature, lithium cell.

  15. Hollow carbon-nanotube/carbon-nanofiber hybrid anodes for Li-ion batteries.

    Science.gov (United States)

    Chen, Yuming; Li, Xiaoyan; Park, Kyusung; Song, Jie; Hong, Jianhe; Zhou, Limin; Mai, Yiu-Wing; Huang, Haitao; Goodenough, John B

    2013-11-06

    By a novel in situ chemical vapor deposition, activated N-doped hollow carbon-nanotube/carbon-nanofiber composites are prepared having a superhigh specific Brunauer–Emmett–Teller (BET) surface area of 1840 m(2) g(–1) and a total pore volume of 1.21 m(3) g(–1). As an anode, this material has a reversible capacity of ~1150 mAh g(–1) at 0.1 A g(–1) (0.27 C) after 70 cycles. At 8 A g(–1) (21.5 C), a capacity of ~320 mAh g(–1) fades less than 20% after 3500 cycles, which makes it a superior anode material for a Li-ion battery.

  16. Binding of nickel and zinc ions with activated carbon prepared from ...

    African Journals Online (AJOL)

    Activated carbon was prepared from sugar cane fibre by carbonizing at 500 oC for 30 minutes. This was followed by activation with ammonium chloride. The activated carbon was characterised in terms of pH, bulk density, ash content, surface area and surface charge. Equilibrium sorption of nickel and zinc ions by the ...

  17. Development and tests of an anode readout TPC with high track separability for large solid angle relativistic ion experiments

    International Nuclear Information System (INIS)

    Lindenbaum, S.J.; Foley, K.J.; Eiseman, S.E.

    1988-01-01

    We have developed, constructed and tested an anode readout TPC with high track separability which is suitable for large solid angle relativistic ion experiments. The readout via rows of short anode wires parallel to the beam has been found in tests to allow two-track separability of ∼2-3 mm. The efficiency of track reconstruction for events from a target, detected inside the MPS 5 KG magnet, is estimated to be >90% for events made by incident protons and pions. 15 GeV/c x A Si ion beams at a rate of ∼25 K per AGS pulse were permitted to course through the chamber and did not lead to any problems. When the gain was reduced to simulate the total output of a minimum ionizing particle, many Si ion tracks were also detected simultaneously with high efficiency. The resolution along the drift direction (parallel to the MPS magnetic field and perpendicular to the beam direction) was <1 mm and the resolution along the other direction /perpendicular/ to the beam direction was <1 mm also. 3 refs., 5 figs

  18. Cell survival in carbon beams - comparison of amorphous track model predictions

    DEFF Research Database (Denmark)

    Grzanka, L.; Greilich, S.; Korcyl, M.

    distribution models, and gamma response models was developed. This software can be used for direct numerical comparison between the models, submodels and their parameters and experimental data. In the present paper, we look at 10%-survival data from cell lines irradiated in vitro with carbon and proton beams...... neutrons, stopped pions, and heavy ion beams. Nucl Instrum Meth. 1973;111:93-116. 2.Weyrather WK, Kraft G. RBE of carbon ions: experimental data and the strategy of RBE calculation for treatment planning. Radiother Oncol. 2004;73(Suppl 2):161-9. 3.Greilich S, Grzanka L, Bassler N, Andersen CE, Jäkel O...... irradiation. The aim of this paper is to compare the predictions from different amorphous approaches found in the literature - more specifically the phenomenological, analytical model by Katz and co-workers [1] and a Monte-Carlo based full as implemented for example in the local effect model by Scholz et al...

  19. Strong matrix effect in low-energy He+ ion scattering from carbon

    International Nuclear Information System (INIS)

    Mikhailov, S.N.; Van den Oetelaar, L.C.A.; Brongersma, H.H.

    1994-01-01

    In low-energy ion scattering the contribution of neutralization processes to the scattered ion yield is very important in quantification. Neutralization of low-energy (1-3.5 keV) He + ions by carbon is found to be much stronger for graphitic than for carbidic carbon. The ion fraction for graphitic carbon for 2.5 keV 3 He + scattering over 136 is about 60 times lower than that for carbidic carbon. For the 4 He + isotope the effect is even larger. Such a strong matrix effect for one element has not been measured before in low-energy (1-3.5 keV) inert-gas ion scattering. The neutralization behaviour is discussed in terms of a special quasi-resonant neutralization process for graphite. ((orig.))

  20. Impact of Various Beam Parameters on Lateral Scattering in Proton and Carbon-ion Therapy.

    Science.gov (United States)

    Ebrahimi Loushab, M; Mowlavi, A A; Hadizadeh, M H; Izadi, R; Jia, S B

    2015-12-01

    In radiation therapy with ion beams, lateral distributions of absorbed dose in the tissue are important. Heavy ion therapy, such as carbon-ion therapy, is a novel technique of high-precision external radiotherapy which has advantages over proton therapy in terms of dose locality and biological effectiveness. In this study, we used Monte Carlo method-based Geant4 toolkit to simulate and calculate the effects of energy, shape and type of ion beams incident upon water on multiple scattering processes. Nuclear reactions have been taken into account in our calculation. A verification of this approach by comparing experimental data and Monte Carlo methods will be presented in an upcoming paper. Increasing particle energies, the width of the Bragg curve becomes larger but with increasing mass of particles, the width of the Bragg curve decreases. This is one of the advantages of carbon-ion therapy to treat with proton. The transverse scattering of dose distribution is increased with energy at the end of heavy ion beam range. It can also be seen that the amount of the dose scattering for carbon-ion beam is less than that of proton beam, up to about 160mm depth in water. The distortion of Bragg peak profiles, due to lateral scattering of carbon-ion, is less than proton. Although carbon-ions are primarily scattered less than protons, the corresponding dose distributions, especially the lateral dose, are not much less.

  1. Primary result of application of carbon ion beam and gamma ray for rice breeding improvement

    International Nuclear Information System (INIS)

    Dao Thanh Bang; Nguyen Hong Nhung; Nguyen Pham Hung; Le Thi Lieu; Le Huy Tam

    2011-01-01

    Recently, Carbon ion beam have been recently attracted as mutagens. A characteristic feature of ion beams is their ability to deposit high energy on a target, densely and locally, as opposed to low linear energy transfer radiation such as gamma rays and X rays. In Vietnam, application of carbon ion beam just starting through cooperation FNCA between Japan and ASEAN countries from 2009. In this report, we want to report primary result of application carbon ion beam and gamma ray for rice breeding improvement of Khang dan 18. Through primary experimental for optimum dose for carbon ion beam we found that the dose of 40 and 60 Gy was suitable for Khang dan variety treatment. Based on optimum dose 40 and 60 Gy of carbon ion beam and 150 and 200 Gy of gamma ray we irradiated for Khang dan variety. The higher dose, the lower seed set ratio were determined both ion beam and gamma ray. Especial in carbon ion beam experiment at the dose of 60 Gy was 39.18% in small experiment and more than 20% seed set ratio at the real experiment. At M4 generation, in the experiment with carbon ion beam at the dose of 60 Gy we received mutant which increase the weight of 1000 seeds (23.0 g) compare to the control 19.7 g meanwhile experiment with gamma ray at the dose of 200 Gy we received some mutant not much change in the seed weight. This may show that carbon ion beam more effective than gamma ray in term of change some characteristics of rice. (author)

  2. Anodic stripping voltammetric determination of silver ion at a carbon paste electrode modified with carbon nanotubes

    International Nuclear Information System (INIS)

    Tashkhourian, J.; Javadi, S.; Ana, F.N.

    2011-01-01

    A carbon paste electrode (CPE) was modified with multi-wall carbon nanotubes and successfully applied to the determination of silver ion by differential pulse anodic stripping voltammetry. Compared to a conventional CPE, a remarkably improved peak current response and sensitivity is observed. The analytical procedure consisted of an open circuit accumulation step for 2 min in -0.4 V, this followed by an anodic potential scan between +0.2 and + 0.6 V to obtain the voltammetric peak. The oxidation peak current is proportional to the concentration of silver ion in the range from 1.0 x 10 -8 to 1.0 x 10 -5 mol L -1 , with a detection limit of 1.8 x 10 -9 mol L -1 after an accumulation time of 120 s. The relative standard deviation for 7 successive determinations of Ag(I) at 0.1 μM concentration is 1.99%. The procedure was validated by determining Ag(I) in natural waters. (author)

  3. [Composition of organic carbon/elemental carbon and water-soluble ions in rice straw burning].

    Science.gov (United States)

    Hong, Lei; Liu, Gang; Yang, Meng; Xu, Hui; Li, Jiu-hai; Chen, Hui-yu; Huang, Ke; Yang, Wei-zong; Wu, Dan

    2015-01-01

    Six types of rice straw were selected in China in this paper, the homemade biomass combustion devices were used to simulate the outdoor burning. The concentrations of organic carbon (OC), elemental carbon (C) and water-soluble ions in particular matter produced by the flaming and smoldering were analyzed using Thermal Optical Carbon Analyzer (Model 2001A) and Ion Chromatography(ISC 2000/ISC 3000). The results showed that the mean value of OC (EFoc) and EC (EFEC) emission factors were (6.37 +/- 1.86) g x kg(-1) and (1.07 +/- 0.30) g x kg(-1) under the flaming conditions, respectively, while under the smoldering conditions the two mean values were (37.63 +/- 6.26) g x kg(-1) and (4.98 x 1.42) g x kg(-1). PM, OC and EC emitted from the same kind of rice straw had similar change trends. The average values of OC/EC under flaming and smoldering were 5.96 and 7.80, and the value of OC/PM was almost unchanged along with the combustion state. Nevertheless, the values of EC/PM under flaming and smoldering were 0.06-0.08 and 0.08-0.11, respectively. The trend of combustion state could be determined using the ratio of EC/PM and the RZ of emitted OC and EC through those two types of combustion reached 0. 97, which was significantly correlated at the 0. 01 level. Among the anions, Cl- showed the highest concentration, the results indicated that the average value of of Cl- emission factor was (0.246 +/- 0.150) g x kg(-1) under flaming, while it was (0.301 +/- 0.274) g x kg(-1) under smoldering. However, A big difference between flaming and smoldering was found in the average value of K+ emission factor, where (0.118 +/- 0.051) g x kg(-1) of the former was significantly higher than the latter (0.053 +/- 0.031) g x kg(-1). When it came to Na, the result of smoldering was significantly higher than that of flaming. The correlation between water-soluble ions in flaming was more significant than smoldering. Rice straw burning could be distinguished from fossil fuels and some other

  4. Uranium Distribution in Some Carbonate and Phosphate Rocks Using Fission Track Registration

    International Nuclear Information System (INIS)

    Jubeli, Y.M

    1998-01-01

    An integrated geochemical and petrological procedure was used to investigate the controls on uranium distribution in some carbonate, phosphate and other sedimentary rocks. The fission track registration technique, along with geochemical analysis of uranium was applied to effectively locate, evaluate and identify the patterns of uranium distribution within these rocks and their constituents. Differences in the density of the tracks were found in isotropic and anisotropic grains of coprolite, ovulite, glauconite, calcite and cellophane, as well as, apatite and other phosphatic particles. The variations in uranium concentrations seem to be related to more than one type of uranium incorporation mechanism, particularly caused by syngenetic and epigenetic processes. It was concluded that the obtained variations in U content are due to a combination of sedimentological, textural, geochemical, physiochemical and a few other controls and mechanisms

  5. Carbon Quantum Dots and Their Derivative 3D Porous Carbon Frameworks for Sodium-Ion Batteries with Ultralong Cycle Life.

    Science.gov (United States)

    Hou, Hongshuai; Banks, Craig E; Jing, Mingjun; Zhang, Yan; Ji, Xiaobo

    2015-12-16

    A new methodology for the synthesis of carbon quantum dots (CQDs) for large production is proposed. The as-obtained CQDs can be transformed into 3D porous carbon frameworks exhibiting superb sodium storage properties with ultralong cycle life and ultrahigh rate capability, comparable to state-of-the-art carbon anode materials for sodium-ion batteries. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Proton induced target fragmentation studies on solid state nuclear track detectors using Carbon radiators

    Science.gov (United States)

    Szabó, J.; Pálfalvi, J. K.; Strádi, A.; Bilski, P.; Swakoń, J.; Stolarczyk, L.

    2018-04-01

    One of the limiting factors of an astronaut's career is the dose received from space radiation. High energy protons, being the main components of the complex radiation field present on a spacecraft, give a significant contribution to the dose. To investigate the behavior of solid state nuclear track detectors (SSNTDs) if they are irradiated by such particles, SSNTD stacks containing carbon blocks were exposed to high energy proton beams (70, 100, 150 and 230 MeV) at the Proteus cyclotron, IFJ PAN -Krakow. The incident protons cannot be detected directly; however, tracks of secondary particles, recoils and fragments of the constituent atoms of the detector material and of the carbon radiator are formed. It was found that as the proton energy increases, the number of tracks induced in the PADC material by secondary particles decreases. From the measured geometrical parameters of the tracks the linear energy transfer (LET) spectrum and the dosimetric quantities were determined, applying appropriate calibration. In the LET spectra the LET range of the most important secondary particles could be identified and their abundance showed differences in the spectra if the detectors were short or long etched. The LET spectra obtained on the SSNTDs irradiated by protons were compared to LET spectra of detectors flown on the International Space Station (ISS): they were quite similar, resulting in a quality factor difference of only 5%. Thermoluminescent detectors (TLDs) were applied in each case to measure the dose from primary protons and other lower LET particles present in space. Comparing and analyzing the results of the TLD and SSNTD measurements, it was obtained that proton induced target fragments contributed to the total absorbed dose in 3.2% and to the dose equivalent in 14.2% in this particular space experiment.

  7. Molecular analysis of carbon ion-induced mutations in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Shikazono, Naoya; Tanaka, Atsushi; Watanabe, Hiroshi; Tano, Shigemitsu; Yokota, Yukihiko

    1998-01-01

    In order to elucidate the characteristics of the mutations induced by ion particles at the molecular level in plants, mutated loci in carbon ion-induced mutants of Arabidopsis were investigated by PCR and Southern blot analyses. In the present study, two lines of gl1 mutant and two lines of tt4 mutant were isolated after carbon ion-irradiation. Out of four mutants, one had a deletion, other two contained rearrangements, and one had a point-like mutation. From the present result, it was suggested that ion particles induced different kinds of alterations of the DNA and therefore they could produce various types of mutant alleles in plants. (author)

  8. Characterization of surface enhancement of carbon ion-implanted TiN coatings by metal vapor vacuum arc ion implantation

    CERN Document Server

    Chang, C L

    2002-01-01

    The modification of the surfaces of energetic carbon-implanted TiN films using metal vapor vacuum arc (MEVVA) ion implantation was investigated, by varying ion energy and dose. The microhardness, microstructure and chemical states of carbon, implanted on the surface layer of TiN films, were examined, as functions of ion energy and dose, by nanoindenter, transmission electron microscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. Results revealed that the microhardness increased from 16.8 up to 25.3 GPa and the friction coefficient decreased to approximately 0.2, depending on the implanted ion energy and dose. The result is attributed to the new microcrystalline phases of TiCN and TiC formed, and carbon concentration saturation of the implanted matrix can enhance the partial mechanical property of TiN films after MEVVA treatment. The concentration distribution, implantation depth and chemical states of carbon-implanted TiN coatings depended strongly on the ion dose and...

  9. Selective removal of carbon-14 from ion exchange resins using supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Dias, S.A.; Krasznai, J.P.

    1996-01-01

    Ion exchange resins (IX) are used extensively in CANDU-PHWR (Canada Deuterium Uranium - Pressurized Heavy Water Reactor) and other reactor systems worldwide to remove ionic contaminants from various coolant circuits. Spent IX resins represent a significant volume of low and intermediate level radioactive waste. The presence of long-lived C-14 which is found in significant quantities in IX resins from CANDU reactors, complicates the disposal of these resins. Several experiments were conducted with carbon dioxide under subcritical and supercritical conditions to determine the feasibility of removing C-14 present as carbonate and/or bicarbonate on IX resins. It has been established that resins containing inorganic C-14 undergo rapid isotopic exchange when exposed to inactive carbon dioxide under supercritical conditions. This treatment reduces the C-14 to the limits of detection and leaves other radioisotopes on the resins largely unaffected. This selective and highly efficient means to remove long-lived C-14 activity from CANDU spent IX resins allows the resin waste to be reclassified as low level waste. This lower classification simplifies the handling, transportation and eventual disposal of IX resins which translates to a very significant cost saving. Since the process is selective the C-14 can be enriched and recovered for commercial purposes

  10. Simulating radial dose of ion tracks in liquid water simulated with Geant4-DNA: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Incerti, S., E-mail: incerti@cenbg.in2p3.fr [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Université de Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); Psaltaki, M. [National Technical University of Athens, Athens (Greece); Gillet, P.; Barberet, Ph. [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Université de Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); Bardiès, M. [CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse (France); Bernal, M.A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, SP (Brazil); Bordage, M.-C. [CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse (France); Breton, V. [Clermont Université, CNRS/IN2P3, Laboratoire de Physique Corpusculaire, UMR6533, Aubière (France); Davidkova, M. [Department of Radiation Dosimetry, Nuclear Physics Institute ASCR, Na Truhlářce 39/64, Praha 8 (Czech Republic); Delage, E. [Clermont Université, CNRS/IN2P3, Laboratoire de Physique Corpusculaire, UMR6533, Aubière (France); El Bitar, Z. [Institut Pluridisciplinaire Hubert Curien, 23 rue du Loess, BP28, 67037 Strasbourg Cedex 2 (France); Francis, Z. [Université Saint Joseph, Faculty of Sciences, Department of Physics, Beirut (Lebanon); Guatelli, S. [Centre for Medical Radiation Physics, University of Wollongong, NSW (Australia); Ivanchenko, A. [Geant4 Associates International Ltd (United Kingdom); Ivanchenko, V. [Geant4 Associates International Ltd (United Kingdom); Ecoanalytica, 119899 Moscow (Russian Federation); and others

    2014-08-15

    An accurate modeling of radial energy deposition around ion tracks is a key requirement of radiation transport software used for simulations in radiobiology at the sub-cellular scale. The work presented in this paper is part of the on-going benchmarking of the “Geant4-DNA” physics processes and models, which are available in the Geant4 Monte Carlo simulation toolkit for the low energy transport of particles in liquid water. We present for the first time radial dose distributions of incident ion tracks simulated with “Geant4-DNA”. Simulation results are compared to other results available in the literature, obtained from analytical calculations, step-by-step Monte Carlo simulations and measurements. They show a reasonable agreement with reference data.

  11. Tracking small mountainous river derived terrestrial organic carbon across the active margin marine environment

    Science.gov (United States)

    Childress, L. B.; Blair, N. E.; Orpin, A. R.

    2015-12-01

    Active margins are particularly efficient in the burial of organic carbon due to the close proximity of highland sources to marine sediment sinks and high sediment transport rates. Compared with passive margins, active margins are dominated by small mountainous river systems, and play a unique role in marine and global carbon cycles. Small mountainous rivers drain only approximately 20% of land, but deliver approximately 40% of the fluvial sediment to the global ocean. Unlike large passive margin systems where riverine organic carbon is efficiently incinerated on continental shelves, small mountainous river dominated systems are highly effective in the burial and preservation of organic carbon due to the rapid and episodic delivery of organic carbon sourced from vegetation, soil, and rock. To investigate the erosion, transport, and burial of organic carbon in active margin small mountainous river systems we use the Waipaoa River, New Zealand. The Waipaoa River, and adjacent marine depositional environment, is a system of interest due to a large sediment yield (6800 tons km-2 yr-1) and extensive characterization. Previous studies have considered the biogeochemistry of the watershed and tracked the transport of terrestrially derived sediment and organics to the continental shelf and slope by biogeochemical proxies including stable carbon isotopes, lignin phenols, n-alkanes, and n-fatty acids. In this work we expand the spatial extent of investigation to include deep sea sediments of the Hikurangi Trough. Located in approximately 3000 m water depth 120 km from the mouth of the Waipaoa River, the Hikurangi Trough is the southern extension of the Tonga-Kermadec-Hikurangi subduction system. Piston core sediments collected by the National Institute of Water and Atmospheric Research (NIWA, NZ) in the Hikurangi Trough indicate the presence of terrestrially derived material (lignin phenols), and suggest a continuum of deposition, resuspension, and transport across the margin

  12. 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

  13. Coupled chemical reactions in dynamic nanometric confinement: VII. Biosensors based on swift heavy ion tracks with membranes

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Munoz, G. H.; García Arellano, H.; Alfonta, L.; Vacík, Jiří; Kiv, A.; Hnatowicz, Vladimír

    2017-01-01

    Roč. 172, 1-2 (2017), s. 159-173 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : biotechnology * tracks * swift heavy ions * polymers * etching Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nano-materials (production and properties) Impact factor: 0.443, year: 2016

  14. Effect of ion velocity on creation of point defects halos of latent tracks in LiF

    Czech Academy of Sciences Publication Activity Database

    Volkov, A.E.; Schwartz, K.; Medvedev, Nikita; Trautmann, C.

    2017-01-01

    Roč. 407, Sep (2017), s. 80-85 ISSN 0168-583X R&D Projects: GA MŠk LG15013; GA MŠk(CZ) LM2015083 Institutional support: RVO:68378271 Keywords : swift heavy ion * electronic stopping * track * LiF * color centers * defect halo Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.109, year: 2016

  15. Tuning the Solid Electrolyte Interphase for Selective Li- and Na-Ion Storage in Hard Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Fernando A. [Department of Chemical Engineering, Texas A& M University, College Station TX 77843-3122 USA; Yan, Pengfei [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Engelhard, Mark H. [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Marzouk, Asma [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, P.O. Box 5825 Doha Qatar; Wang, Chongmin [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Xu, Guiliang [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue Argonne IL 60439 USA; Chen, Zonghai [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue Argonne IL 60439 USA; Amine, Khalil [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue Argonne IL 60439 USA; Liu, Jun [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Sprenkle, Vincent L. [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; El-Mellouhi, Fedwa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, P.O. Box 5825 Doha Qatar; Balbuena, Perla B. [Department of Chemical Engineering, Texas A& M University, College Station TX 77843-3122 USA; Li, Xiaolin [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA

    2017-03-07

    Solid-electrolyte interphase (SEI) with controllable properties are highly desirable to improve battery performance. In this paper, we use a combined experimental and simulation approach to study the SEI formation on hard carbon in Li and Na-ion batteries. We show that with proper additives, stable SEI can be formed on hard carbon by pre-cycling the electrode materials in Li or Na-ion electrolyte. Detailed mechanistic studies suggest that the ion transport in the SEI layer is kinetically controlled and can be tuned by the applied voltage. Selective Na and Li-ion SEI membranes are produced using the Na or Li-ion based electrolytes respectively. The large Na ion SEI allows easy transport of Li ions, while the small Li ion SEI shuts off the Na-ion transport. Na-ion storage can be manipulated by tuning the SEI with film-forming electrolyte additives or preforming a SEI on the electrodes’ surface. The Na specific capacity can be controlled to <25 mAh/g, ~1/10 of the normal capacity (250 mAh/g). Unusual selective/preferential transport of Li-ion is demonstrated by preforming a SEI on the electrode’s surface and corroborated with a mixed electrolyte. This work may provide new guidance for preparing good ion selective conductors using electrochemical approaches in the future.

  16. A Monte Carlo track structure simulation code for the full-slowing-down carbon projectiles of energies 1 keV u(-1)-10 MeV u(-1) in water.

    Science.gov (United States)

    Liamsuwan, T; Nikjoo, H

    2013-02-07

    The paper presents a new Monte Carlo track structure code (KURBUC_carbon) for simulations of full-slowing-down carbon projectiles C(0)-C(6+) of energies 1 keV u(-1)-10 MeV u(-1) in water vapour. The code facilitates investigation of the spatial resolution effect for scoring track parameters under the Bragg peak of a carbon ion beam. Interactions of carbon projectiles and secondary electrons were followed interaction-by-interaction down to a 1 keV u(-1) cutoff for primary ions and down to 10 eV for electrons. Electronic interactions and nuclear elastic scattering were taken into account, including charge exchange reactions and double electronic interactions for the carbon projectiles. The reliability of the code was tested for radial dose, range and W-value. The calculated results were compared with the published experimental data and other model calculations. The results obtained showed good agreement in most cases where comparisons could be made. Depth dose profiles for 1-10 MeV u(-1) C(6+) were used to form a spread-out Bragg peak (SOBP) of 0.35 mm width in water. At all depths of the SOBP, the energy distributions of the carbon projectiles varied appreciably with the change in the scoring volume. The corresponding variation was nearly negligible for the track average linear energy transfer (LET), except at the distal end of the SOBP. By varying the scoring slab thickness from 1 to 100 µm, the maximum track average LET decreased by ∼30%. The Monte Carlo track structure simulation in the full-slowing-down mode is a powerful tool for investigation of the biophysical properties of radiation tracks under the Bragg peak and SOBP of a carbon ion beam. For estimation of radiation effectiveness under the Bragg peak the new Monte Carlo track structure code provides yet another accurate and effective dosimetry tool at a single cell level. This is because radiobiology within tissue elements can be understood better with dosimetry at cellular and subcellular

  17. 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.

    Planktonic foraminifera shell weights have been recognized as possible proxy for surface water carbonate ion concentration [CO sup(=) sub(3)] and atmospheric CO sub(2). However, to utilize this proxy, it is important to understand whether shell...

  18. Peripheral nerve regeneration through a silicone chamber implanted with negative carbon ions: Possibility to clinical application

    Science.gov (United States)

    Ikeguchi, Ryosuke; Kakinoki, Ryosuke; Tsuji, Hiroshi; Yasuda, Tadashi; Matsuda, Shuichi

    2014-08-01

    We investigated whether a tube with its inner surface implanted with negative-charged carbon ions (C- ions) would enable axons to extend over a distance greater than 10 mm. The tube was found to support nerves regenerating across a 15-mm-long inter-stump gap. We also investigated whether a C- ion-implanted tube pretreated with basic fibroblast growth factor (bFGF) promotes peripheral nerve regeneration. The C- ion implanted tube accelerated nerve regeneration, and this effect was enhanced by bFGF. Silicone treated with C- ions showed increased hydrophilic properties and cellular affinity, and axon regeneration was promoted with this increased biocompatibility.

  19. Thermal property tuning in aligned carbon nanotube films and random entangled carbon nanotube films by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Chen, Di; Wang, Xuemei [Department of Nuclear Engineering, Texas A& M University, College Station, Texas 77843 (United States); Bykova, Julia S.; Zakhidov, Anvar A. [The Alan G. MacDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75080 (United States); Shao, Lin, E-mail: lshao@tamu.edu [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Department of Nuclear Engineering, Texas A& M University, College Station, Texas 77843 (United States)

    2015-10-12

    Ion irradiation effects on thermal property changes are compared between aligned carbon nanotube (A-CNT) films and randomly entangled carbon nanotube (R-CNT) films. After H, C, and Fe ion irradiation, a focusing ion beam with sub-mm diameter is used as a heating source, and an infrared signal is recorded to extract thermal conductivity. Ion irradiation decreases thermal conductivity of A-CNT films, but increases that of R-CNT films. We explain the opposite trends by the fact that neighboring CNT bundles are loosely bonded in A-CNT films, which makes it difficult to create inter-tube linkage/bonding upon ion irradiation. In a comparison, in R-CNT films, which have dense tube networking, carbon displacements are easily trapped between touching tubes and act as inter-tube linkage to promote off-axial phonon transport. The enhancement overcomes the phonon transport loss due to phonon-defect scattering along the axial direction. A model is established to explain the dependence of thermal conductivity changes on ion irradiation parameters including ion species, energies, and current.

  20. Carbon Ion Implantation: A Good Method to Enhance the Biocompatibility of Silicone Rubber.

    Science.gov (United States)

    Zhou, Xin; Chen, Xing; Mao, Tong-cun; Li, Xiang; Shi, Xiao-hua; Fan, Dong-li; Zhang, Yi-ming

    2016-04-01

    Silicone rubber and silicone rubber-based materials have been used as medical tissue implants in the field of plastic surgery for many years, but there are still some reports of adverse reactions to long-term implants. Earlier studies have shown that ion implantation could enhance the biocompatibility of biomaterials. However, whether ion implantation has a good effect on silicone rubber is unknown. Three types of carbon ion silicone rubber were obtained by implanting three doses of carbon ions. Then, the antibacterial adhesion properties and the in vivo host responses were evaluated. The antibacterial adhesion properties were examined by plate colony counting, fluorescence staining, and scanning electron microscopic observation. The host responses were evaluated by surveying inflammation and fiber capsule formation that developed after subcutaneous implantation in Sprague-Dawley rats for 7, 30, 90, and 180 days. In addition, the possible mechanism by which ion implantation enhanced the biocompatibility of the biomaterial was investigated and discussed. Carbon ion silicone rubber exhibits less bacterial adhesion, less collagen deposition, and thinner and weaker tissue capsules. Immunohistochemical staining results for CD4, tumor necrosis factor-α, α-smooth muscle actin, and elastin showed the possible mechanism enhancing the biocompatibility of silicone rubber. These data indicate that carbon ion silicone rubber exhibits good antibacterial adhesion properties and triggers thinner and weaker tissue capsules. In addition, high surface roughness and high zeta potential may be the main factors that induce the unique biocompatibility of carbon ion silicone rubber. Ion implantation should be considered for further investigation and application, and carbon ion silicone rubber could be a better biomaterial to decrease silicone rubber-initiated complications.

  1. First report on preparation of poly (nitro-carbonate) thermoset polymers for nuclear track detection

    Energy Technology Data Exchange (ETDEWEB)

    Mascarenhas, Adlete A.A.; Mandrekar, V.K. [Department of Chemistry, Goa University, Taleigao Plateau, North Goa, PIN 403 206 (India); Kalsi, P.C. [Radiochemistry Division, B.A.R.C., Trombay 400 085 (India); Tilve, S.G. [Department of Chemistry, Goa University, Taleigao Plateau, North Goa, PIN 403 206 (India); Nadkarni, V.S. [Department of Chemistry, Goa University, Taleigao Plateau, North Goa, PIN 403 206 (India)], E-mail: nitin@unigoa.ac.in

    2009-01-15

    In an attempt to study the effect of various radiation sensitive groups in the polymer matrix and their relation to the sensitivity towards charged particles, we have designed two new monomers Allyl bis-(2-nitroxy-ethyl) carbamate (ABNEC) and prepared its copolymer with ADC. Since, the ABNEC monomer was not thermally much stable, we designed another novel monomer containing (-CNO{sub 2}) group, called tris-(2,4-dioxa-3-oxohept-6-en-1-yl)nitromethane (TDONM) and prepared its homopolymer as well as copolymer with ADC. These are thermoset poly(nitro-carbonate) materials and are being reported as track detectors for the first time. The kinetics of polymerization for these monomers was studied. Due to thermal instability of ABNEC and TDONM monomers, special care is required during their polymerization. The preliminary studies carried out show that, the copolymers ABNEC-ADC and TDONM-ADC are almost comparable to PADC track detectors. A brief description of the study of some of the etching conditions, the effect of initiator concentration on the alpha sensitivity of the materials and also track detection efficiency studies in comparison with commercially available PADC (Pershore Moldings, UK) are reported.

  2. First report on preparation of poly (nitro-carbonate) thermoset polymers for nuclear track detection

    International Nuclear Information System (INIS)

    Mascarenhas, Adlete A.A.; Mandrekar, V.K.; Kalsi, P.C.; Tilve, S.G.; Nadkarni, V.S.

    2009-01-01

    In an attempt to study the effect of various radiation sensitive groups in the polymer matrix and their relation to the sensitivity towards charged particles, we have designed two new monomers Allyl bis-(2-nitroxy-ethyl) carbamate (ABNEC) and prepared its copolymer with ADC. Since, the ABNEC monomer was not thermally much stable, we designed another novel monomer containing (-CNO 2 ) group, called tris-(2,4-dioxa-3-oxohept-6-en-1-yl)nitromethane (TDONM) and prepared its homopolymer as well as copolymer with ADC. These are thermoset poly(nitro-carbonate) materials and are being reported as track detectors for the first time. The kinetics of polymerization for these monomers was studied. Due to thermal instability of ABNEC and TDONM monomers, special care is required during their polymerization. The preliminary studies carried out show that, the copolymers ABNEC-ADC and TDONM-ADC are almost comparable to PADC track detectors. A brief description of the study of some of the etching conditions, the effect of initiator concentration on the alpha sensitivity of the materials and also track detection efficiency studies in comparison with commercially available PADC (Pershore Moldings, UK) are reported

  3. Carbon nanotubes in Li-ion batteries: A review

    Energy Technology Data Exchange (ETDEWEB)

    Sehrawat, Poonam [Centre for Nanoscience and Nanotechnology, Jamia Millia Islamia (A Central University), Jamia Nagar, New Delhi 110025 (India); Julien, C. [Sorbonne Universities, University Pierre and Marie CURIE – Paris-6, Paris (France); Islam, S.S., E-mail: sislam@jmi.ac.in [Centre for Nanoscience and Nanotechnology, Jamia Millia Islamia (A Central University), Jamia Nagar, New Delhi 110025 (India)

    2016-11-15

    Highlights: • LIBs are gaining immense attention among rechargeable battery systems. • HEVs and portables demand higher power and life than the conventional systems. • CNTs owing to their unique 1D structure can enhance performance of LIBs. • We report contemporary advancements in CNTs technology as applicable to LIBs. • CNTs-composite systems have also been reviewed. - Abstract: Portable-electronics epitomizing technological breakthrough in history of mankind, are universal reality thanks to rechargeable batteries. LIBs, lithium-ion batteries, owing to high-reversible capacity, high-power capability, good-safety, long-life and zero-memory effects are at the heart of this revolution. Nonetheless, longer-battery-life, higher-current- and power-density, better-safety, and flexibility, crucial for portables and hybrid-electric-vehicles further fuel the research to better their electrochemistry. Electrode materials are vital for performance of batteries. Recent developments in nanoscience and nanotechnology offer potential prospects to devise novel-nanostructured electrode materials for next-generation better-performing LIBs. Nanostructured materials are pivotal to these progresses due to their manageable surface-area, stunted mass and charge-diffusion span, and volume change acclimatization during charging/discharging. CNTs, carbon-nanotubes, with distinct 1D-tubular structure, excellent electrical and thermal conductivities, mechanical flexibility and significantly large surface-area, are considered ideal additives to enrich electrodes’ chemistry. Here, we observe contemporary developments in synthesis and characterization of CNTs and CNTs-based nanostructured composite-electrodes for utilization in LIBs.

  4. Carbon nanotubes in Li-ion batteries: A review

    International Nuclear Information System (INIS)

    Sehrawat, Poonam; Julien, C.; Islam, S.S.

    2016-01-01

    Highlights: • LIBs are gaining immense attention among rechargeable battery systems. • HEVs and portables demand higher power and life than the conventional systems. • CNTs owing to their unique 1D structure can enhance performance of LIBs. • We report contemporary advancements in CNTs technology as applicable to LIBs. • CNTs-composite systems have also been reviewed. - Abstract: Portable-electronics epitomizing technological breakthrough in history of mankind, are universal reality thanks to rechargeable batteries. LIBs, lithium-ion batteries, owing to high-reversible capacity, high-power capability, good-safety, long-life and zero-memory effects are at the heart of this revolution. Nonetheless, longer-battery-life, higher-current- and power-density, better-safety, and flexibility, crucial for portables and hybrid-electric-vehicles further fuel the research to better their electrochemistry. Electrode materials are vital for performance of batteries. Recent developments in nanoscience and nanotechnology offer potential prospects to devise novel-nanostructured electrode materials for next-generation better-performing LIBs. Nanostructured materials are pivotal to these progresses due to their manageable surface-area, stunted mass and charge-diffusion span, and volume change acclimatization during charging/discharging. CNTs, carbon-nanotubes, with distinct 1D-tubular structure, excellent electrical and thermal conductivities, mechanical flexibility and significantly large surface-area, are considered ideal additives to enrich electrodes’ chemistry. Here, we observe contemporary developments in synthesis and characterization of CNTs and CNTs-based nanostructured composite-electrodes for utilization in LIBs.

  5. Fission track dating of authigenic quartz in red weathering crusts of carbonate rocks in Guizhou province

    International Nuclear Information System (INIS)

    Liu Xiuming; Wang Shijie; Zhang Feng

    2004-01-01

    The Cenozoic evolution history of Guizhou Province, which is located on the southeastern flank of the Qinghai-Tibet Plateau, is unclear because of the lack of sedimentation records. The red weathering crusts widespread on the Yunnan-Guizhou Plateau may bear critical information about their evolution history. This work firstly determined the ages of four red weathering crusts in eastern, central and northern Guizhou. The material used in fission track dating is well-crystallized quartz occurring in many in-situ weathering crusts of carbonate rocks. The results showed that the fission track ages of quartz vary over a wide range from 1 Ma to 25 Ma in the four profiles, significantly younger than the ages of Triassic and Cambrian parent rocks. In combination with the regionally geological evolution history during the period from 25 Ma to 1 Ma, the ages of quartz can exclude the possibility that the origin of quartz has nothing to do with primary clastic minerals in parent rocks, authigenesis during diagenesis and hydrothermal precipitation or replacement by volcanic activities. It is deduced that the well-crystallized quartz was precipitated from Si-rich weathering fluids during weathering processes of carbonate rocks. The recorded ages of quartz from the four profiles are consistent with the episodes of planation surfaces on the Qinghai-Tibet Plateau, the stages of red soil in the tropics of South China, the tectonically stable periods in Guizhou, and the ages of weathering in other parts of the world during the Cenozoic era. That is to say, the ages of authigenic quartz dated by the fission track method are well feasible and credible. (authors)

  6. Correlated radiative double electron capture (RDEC) in collisions of bare oxygen ions with carbon targets

    Science.gov (United States)

    Simon, A.; Tanis, J. A.; ElKafrawy, T.; Warczak, A.

    2009-11-01

    Multielectron capture processes observed in low energy collisions of bare ions give insight into electron-electron correlations in strong fields. The main intention of this experiment is to observe radiative double electron capture (RDEC) in collisions of bare oxygen ions at energies of a few MeV/u with carbon targets. Measured results are to be compared with recent theoretical calculations.

  7. Interaction of small hydrocarbon ions and Ar(+) with carbon-fibre-composite surfaces at room temperature

    Czech Academy of Sciences Publication Activity Database

    Keim, A.; Rasul, B.; Endstrasser, N.; Scheier, P.; Märk, T. D.; Herman, Zdeněk

    2011-01-01

    Roč. 306, 2-3 (2011), s. 204-209 ISSN 1387-3806 Institutional research plan: CEZ:AV0Z40400503 Keywords : ion-surface collisions * Ar+ and hydrocarbon ions * carbon-fibre-composite surface Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.549, year: 2011

  8. Physical and chemical response of 70 MeV carbon ion irradiated ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 24; Issue 5. Physical and ... Physical and chemical responses of 70 MeV carbon ion irradiated Kapton-H polymer were studied by using UV-visible, FTIR and XRD techniques. The ion ... Department of Physics, Guru Nanak Dev University, Amritsar 143 005, India ...

  9. The electrochemical performance of super P carbon black in reversible Li/Na ion uptake

    NARCIS (Netherlands)

    Peng, B.; Xu, Y.; Wang, Xiaoqun; Shi, Xinghua; Mulder, F.M.

    2017-01-01

    Super P carbon black (SPCB) has been widely used as a conducting additive in Li/Na ion batteries to improve the electronic conductivity. However, there has not yet been a comprehensive study on its structure and electrochemical properties for Li/Na ion uptake, though it is important to

  10. Ion coordination significantly enhances the photocatalytic activity of graphitic-phase carbon nitride.

    Science.gov (United States)

    Gao, Honglin; Yan, Shicheng; Wang, Jiajia; Zou, Zhigang

    2014-06-14

    Here we report a facile surface modification route, metal ion coordination, to improve the photoactivity of carbon nitride. The metal ions coordinating into the plane of g-C3N4 significantly contribute to a drastic increase of the photocatalytic activity in solar hydrogen production as well as in the photodegradation of organic pollutants.

  11. Visualisation of γH2AX Foci Caused by Heavy Ion Particle Traversal; Distinction between Core Track versus Non-Track Damage

    Science.gov (United States)

    Nakajima, Nakako Izumi; Brunton, Holly; Watanabe, Ritsuko; Shrikhande, Amruta; Hirayama, Ryoichi; Matsufuji, Naruhiro; Fujimori, Akira; Murakami, Takeshi; Okayasu, Ryuichi; Jeggo, Penny; Shibata, Atsushi

    2013-01-01

    Heavy particle irradiation produces complex DNA double strand breaks (DSBs) which can arise from primary ionisation events within the particle trajectory. Additionally, secondary electrons, termed delta-electrons, which have a range of distributions can create low linear energy transfer (LET) damage within but also distant from the track. DNA damage by delta-electrons distant from the track has not previously been carefully characterised. Using imaging with deconvolution, we show that at 8 hours after exposure to Fe (∼200 keV/µm) ions, γH2AX foci forming at DSBs within the particle track are large and encompass multiple smaller and closely localised foci, which we designate as clustered γH2AX foci. These foci are repaired with slow kinetics by DNA non-homologous end-joining (NHEJ) in G1 phase with the magnitude of complexity diminishing with time. These clustered foci (containing 10 or more individual foci) represent a signature of DSBs caused by high LET heavy particle radiation. We also identified simple γH2AX foci distant from the track, which resemble those arising after X-ray exposure, which we attribute to low LET delta-electron induced DSBs. They are rapidly repaired by NHEJ. Clustered γH2AX foci induced by heavy particle radiation cause prolonged checkpoint arrest compared to simple γH2AX foci following X-irradiation. However, mitotic entry was observed when ∼10 clustered foci remain. Thus, cells can progress into mitosis with multiple clusters of DSBs following the traversal of a heavy particle. PMID:23967070

  12. Visualisation of γH2AX foci caused by heavy ion particle traversal; distinction between core track versus non-track damage.

    Directory of Open Access Journals (Sweden)

    Nakako Izumi Nakajima

    Full Text Available Heavy particle irradiation produces complex DNA double strand breaks (DSBs which can arise from primary ionisation events within the particle trajectory. Additionally, secondary electrons, termed delta-electrons, which have a range of distributions can create low linear energy transfer (LET damage within but also distant from the track. DNA damage by delta-electrons distant from the track has not previously been carefully characterised. Using imaging with deconvolution, we show that at 8 hours after exposure to Fe (∼200 keV/µm ions, γH2AX foci forming at DSBs within the particle track are large and encompass multiple smaller and closely localised foci, which we designate as clustered γH2AX foci. These foci are repaired with slow kinetics by DNA non-homologous end-joining (NHEJ in G1 phase with the magnitude of complexity diminishing with time. These clustered foci (containing 10 or more individual foci represent a signature of DSBs caused by high LET heavy particle radiation. We also identified simple γH2AX foci distant from the track, which resemble those arising after X-ray exposure, which we attribute to low LET delta-electron induced DSBs. They are rapidly repaired by NHEJ. Clustered γH2AX foci induced by heavy particle radiation cause prolonged checkpoint arrest compared to simple γH2AX foci following X-irradiation. However, mitotic entry was observed when ∼10 clustered foci remain. Thus, cells can progress into mitosis with multiple clusters of DSBs following the traversal of a heavy particle.

  13. Heavy Ion Track Temperature with the High Level of Specific Inelastic Energy Loss in Materials at the Thermal Spike Model

    CERN Document Server

    Didyk, A Yu; Semina, V K

    2003-01-01

    The thermal spike model in materials under the irradiation by swift heavy ions with high specific energy loss is considered taking into account the temperature dependence along the ion trajectrory. The numerical solutions of the temperature system equations for the temperatures of lattice and electrons are obtained, takinig into account the possible heating of lattice up to the melting and evaporation points, i.e., with the two phase transitions are obtained. The pressure in the volume of heavy ion track and their influence on the changes of thermodynamical parameters are introduced. The influence of defects on the "hot" electron free path is discussed. The numerical analysis of the lattice temperature at low and high temperatures of the thermal conductivity and heat capacity parameter values was carried out.

  14. Heavy ion track temperature with the high level of specific inelastic energy loss in materials at the thermal spike model

    International Nuclear Information System (INIS)

    Didyk, A.Yu.; Robuk, V.N.; Semina, V.K.

    2003-01-01

    The thermal spike model in materials under the irradiation by swift heavy ions with high specific energy loss is considered taking into account the temperature dependence along the ion trajectory. The numerical solutions of the temperature system equations for the temperatures of lattice up to the melting and evaporation points, i.e., with the two phase transitions are obtained. The pressure in the volume of heavy ion track and its influence on the changes of thermodynamical parameters are introduced. The influence of defects on the 'hot' electron free path is discussed. The numerical analysis of the lattice temperature at low and high temperatures of the thermal conductivity and heat capacity parameter values was carried out. (author)

  15. Method for intercalating alkali metal ions into carbon electrodes

    Science.gov (United States)

    Doeff, Marca M.; Ma, Yanping; Visco, Steven J.; DeJonghe, Lutgard

    1995-01-01

    A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.

  16. Carbon ion irradiation induced surface modification of polypropylene

    International Nuclear Information System (INIS)

    Saha, A.; Chakraborty, V.; Dutta, R.K.; Chintalapudi, S.N.

    2001-01-01

    Polypropylene was irradiated with 12 C ions of 3.6 and 5.4 MeV energies in the fluence range of 5x10 13 -5x10 14 ions/cm 2 using 3 MV tandem accelerator. Ion penetration was limited to a few microns and surface modifications were investigated by scanning electron microscopy. At the lowest ion fluence only blister formation of various sizes (1-6 μm) were observed, but at higher fluence (1x10 14 ions/cm 2 ) a three-dimensional network structure was found to form. A gradual degradation in the network structure was observed with further increase in the ion fluence. The dose dependence of the changes on surface morphology of polypropylene is discussed

  17. Carbon ion irradiation induced surface modification of polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Saha, A. E-mail: abhijit@alpha.iuc.res.in; Chakraborty, V.; Dutta, R.K.; Chintalapudi, S.N

    2001-12-01

    Polypropylene was irradiated with {sup 12}C ions of 3.6 and 5.4 MeV energies in the fluence range of 5x10{sup 13}-5x10{sup 14} ions/cm{sup 2} using 3 MV tandem accelerator. Ion penetration was limited to a few microns and surface modifications were investigated by scanning electron microscopy. At the lowest ion fluence only blister formation of various sizes (1-6 {mu}m) were observed, but at higher fluence (1x10{sup 14} ions/cm{sup 2}) a three-dimensional network structure was found to form. A gradual degradation in the network structure was observed with further increase in the ion fluence. The dose dependence of the changes on surface morphology of polypropylene is discussed.

  18. Enhancement of SPHK1 in vitro by carbon ion irradiation in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Higo, Morihiro; Uzawa, Katsuhiro; Kawata, Tetsuya; Kato, Yoshikuni; Kouzu, Yukinao; Yamamoto, Nobuharu; Shibahara, Takahiko; Mizoe, Jun-etsu; Ito, Hisao; Tsujii, Hirohiko; Tanzawa, Hideki

    2006-01-01

    Purpose The purpose of this study was to assess the gene expression changes in oral squamous cell carcinoma (OSCC) cells after carbon ion irradiation. Methods and Materials Three OSCC cell lines (HSC2, Ca9-22, and HSC3) were irradiated with accelerated carbon ion beams or X-rays using three different doses. The cellular sensitivities were determined by clonogenic survival assay. To identify genes the expression of which is influenced by carbon ion irradiation in a dose-dependent manner, we performed Affymetrix GeneChip analysis with HG-U133 plus 2.0 arrays containing 54,675 probe sets. The identified genes were analyzed using the Ingenuity Pathway Analysis Tool to investigate the functional network and gene ontology. Changes in mRNA expression in the genes were assessed by real-time reverse transcriptase-polymerase chain reaction. Results We identified 98 genes with expression levels that were altered significantly at least twofold in each of the three carbon-irradiated OSCC cell lines at all dose points compared with nonirradiated control cells. Among these, SPHK1, the expression of which was significantly upregulated by carbon ion irradiation, was modulated little by X-rays. The function of SPHK1 related to cellular growth and proliferation had the highest p value (p = 9.25e-7 to 2.19e-2). Real-time reverse transcriptase-polymerase chain reaction analysis showed significantly elevated SPHK1 expression levels after carbon ion irradiation (p < 0.05), consistent with microarray data. Clonogenic survival assay indicated that carbon ion irradiation could induce cell death in Ca9-22 cells more effectively than X-rays. Conclusions Our findings suggest that SPHK1 helps to elucidate the molecular mechanisms and processes underlying the biologic response to carbon ion beams in OSCC

  19. Poultry litter-based activated carbon for removing heavy metal ions in water.

    Science.gov (United States)

    Guo, Mingxin; Qiu, Guannan; Song, Weiping

    2010-02-01

    Utilization of poultry litter as a precursor material to manufacture activated carbon for treating heavy metal-contaminated water is a value-added strategy for recycling the organic waste. Batch adsorption experiments were conducted to investigate kinetics, isotherms, and capacity of poultry litter-based activated carbon for removing heavy metal ions in water. It was revealed that poultry litter-based activated carbon possessed significantly higher adsorption affinity and capacity for heavy metals than commercial activated carbons derived from bituminous coal and coconut shell. Adsorption of metal ions onto poultry litter-based carbon was rapid and followed Sigmoidal Chapman patterns as a function of contact time. Adsorption isotherms could be described by different models such as Langmuir and Freundlich equations, depending on the metal species and the coexistence of other metal ions. Potentially 404 mmol of Cu2+, 945 mmol of Pb2+, 236 mmol of Zn2+, and 250-300 mmol of Cd2+ would be adsorbed per kg of poultry litter-derived activated carbon. Releases of nutrients and metal ions from litter-derived carbon did not pose secondary water contamination risks. The study suggests that poultry litter can be utilized as a precursor material for economically manufacturing granular activated carbon that is to be used in wastewater treatment for removing heavy metals.

  20. Molecular dynamics study of radiation damage and microstructure evolution of zigzag single-walled carbon nanotubes under carbon ion incidence

    Science.gov (United States)

    Li, Huan; Tang, Xiaobin; Chen, Feida; Huang, Hai; Liu, Jian; Chen, Da

    2016-07-01

    The radiation damage and microstructure evolution of different zigzag single-walled carbon nanotubes (SWCNTs) were investigated under incident carbon ion by molecular dynamics (MD) simulations. The radiation damage of SWCNTs under incident carbon ion with energy ranging from 25 eV to 1 keV at 300 K showed many differences at different incident sites, and the defect production increased to the maximum value with the increase in incident ion energy, and slightly decreased but stayed fairly stable within the majority of the energy range. The maximum damage of SWCNTs appeared when the incident ion energy reached 200 eV and the level of damage was directly proportional to incident ion fluence. The radiation damage was also studied at 100 K and 700 K and the defect production decreased distinctly with rising temperature because radiation-induced defects would anneal and recombine by saturating dangling bonds and reconstructing carbon network at the higher temperature. Furthermore, the stability of a large-diameter tube surpassed that of a thin one under the same radiation environments.

  1. Electrochemical performances and capacity fading behaviors of activated carbon/hard carbon lithium ion capacitor

    International Nuclear Information System (INIS)

    Sun, Xianzhong; Zhang, Xiong; Liu, Wenjie; Wang, Kai; Li, Chen; Li, Zhao; Ma, Yanwei

    2017-01-01

    Highlights: • Three-electrode pouch cell is used to investigate the capacity fading of AC/HC LIC. • the electrode potential swing is critical for the cycleability of a LIC cell. • Different capacity fading behaviors are discussed. • A large-capacity LIC pouch cell has been assembled with a specific energy of 18.1 Wh kg −1 based on the total weight. - Abstract: Lithium ion capacitor (LIC) is one of the most promising electrochemical energy storage devices, which offers rapid charging-discharging capability and long cycle life. We have fabricated LIC pouch cells using an electrochemically-driven lithium pre-doping method through a three-electrode pouch cell structure. The active materials of cathode and anode of LIC cell are activated carbon and pre-lithiated hard carbon, respectively. The electrochemical performances and the capacity fading behaviors of LICs in the voltage range of 2.0 − 4.0 V have been studied. The specific energy and specific power reach 73.6 Wh kg −1 and 11.9 kW kg −1 based on the weight of the active materials in both cathode and anode, respectively. Since the cycling performance is actually determined by hard carbon anode, the anode potential swings are emphasized. The capacity fading of LIC upon cycling is proposed to be caused by the increases of internal resistance and the consumption of lithium stored in anode. Finally, a large-capacity LIC pouch cell has been assembled with a maximum specific energy of 18.1 Wh kg −1 and a maximum specific power of 3.7 kW kg −1 based on the weight of the whole cell.

  2. Ion pairing as a strategy for extraction by modified supercritical carbon dioxide: extraction of radioactive metal ions.

    Science.gov (United States)

    Gawenis, J A; Kauffman, J F; Jurisson, S S

    2001-05-01

    Supercritical fluid carbon dioxide was investigated for its potential to extract perrhenate ion pairs. This has implications for radioactive waste processing because Tc-99, the second row congener of Re, is produced in approximately 6% fission yield from nuclear fuel and pertechnetate is its most common chemical form in aqueous environments. The variables examined to maximize extraction of the perrhenate ion pair were temperature, pressure, solvent modification, and ion-pairing agents. The tetrabutyl-ammonium cation was found to form the most efficient ion pair for extracting perrhenate using methanol-modified (approximately 10%) SFCO2 at 70 degrees C and 477 atm, with 0.083 mg of Re/g of SFCO2 extracted.

  3. Isotopic anomaly for carbon ions in an electron cyclotron resonance ion source

    NARCIS (Netherlands)

    Drentje, A. G.; Kitagawa, A.; Muramatsu, M.

    In many experiments methods were applied to increase the highly charged ion output from an electron cyclotron resonance ion source; the gas-mixing method is still generally being applied. The dominant role of the masses of the ions in the gas-mixture was apparent. Two basically differing mechanisms

  4. Compact ECR ion source with permanent magnets for Carbon therapy

    NARCIS (Netherlands)

    Muramatsu, M; Kitagawa, A; Sakamoto, Y; Sato, Y; Yamada, S; Ogawa, H; Drentje, AG; Biri, S; Yoshida, Y

    Ion sources for the medical facilities should have the following characteristics of easy maintenance, low electric power, good stability, and long operation time without trouble (1 year or longer). For this, a 10 GHz compact electron cyclotron resonance ion source (ECRIS) with all permanent magnets

  5. Monte Carlo simulation of carbon ion radiotherapy for the human eye

    Science.gov (United States)

    Pang, Cheng-Guo; Su, You-Wu; Wang, Wen-Jun; Luo, Xiao-Ming; Xu, Jun-Kui; Li, Wu-Yuan; Yuan, Jiao; Yao, Ze-En

    2015-01-01

    Carbon ion is the mostly common used particle in heavy ion radiotherapy. In this paper, the carbon ion dose in tumor treatment for human eye was calculated with FLUKA code. An 80 MeV/u carbon beam was irradiated into the human eye from two directions. The first was from the lateral-forward direction, which was a typical therapeutic condition. In this case, a maximum dose was deposited in the tumor volume. In the second a beam was irradiated into eyes from the forward direction to simulate a patient gazing directly into treatment beam during therapy, which may cause a certain medical accident. This method can be used for a treatment plan in heavy ion radiotherapy.

  6. [Involvement of carbonate/bicarbonate ions in the superoxide-generating reaction of adrenaline autoxidation].

    Science.gov (United States)

    Sirota, T V

    2015-01-01

    An important role of carbonate/bicarbonate ions has been recognized in the superoxide generating reaction of adrenaline autooxidation in an alkaline buffer (a model of quinoid adrenaline oxidation in the body). It is suggested that these ions are directly involved not only in formation of superoxide anion radical (О(2)(-)) but also other radicals derived from the carbonate/bicarbonate buffer. Using various buffers it was shown that the rate of accumulation of adrenochrome, the end product of adrenaline oxidation, and the rate of О(2)(-)· formation depend on concentration of carbonate/bicarbonate ions in the buffer and that these ions significantly accelerate adrenaline autooxidation thus demonstrating prooxidant properties. The detectable amount of diformazan, the product of nitro blue tetrazolium (NBT) reduction, was significantly higher than the amount of adrenochrome formed; taking into consideration the literature data on О(2)(-)· detection by NBT it is suggested that adrenaline autooxidation is accompanied by one-electron reduction not only of oxygen dissolved in the buffer and responsible for superoxide formation but possible carbon dioxide also dissolved in the buffer as well as carbonate/bicarbonate buffer components leading to formation of corresponding radicals. The plots of the dependence of the inhibition of adrenochrome and diformazan formation on the superoxide dismutase concentration have shown that not only superoxide radicals are formed during adrenaline autooxidation. Since carbonate/bicarbonate ions are known to be universally present in the living nature, their involvement in free radical processes proceeding in the organism is discussed.

  7. In vitro evaluation of photon and carbon ion radiotherapy in combination with chemotherapy in glioblastoma cells

    Directory of Open Access Journals (Sweden)

    Combs Stephanie E

    2012-01-01

    Full Text Available Abstract Background To evaluate the cytotoxic effect of carbon ion radiotherapy and chemotherapy in glioblastoma cells in vitro. Methods and Materials The human glioblastoma (GBM cell line U87 was irradiated with photon radiotherapy (RT doses of 2 Gy, 4 Gy and 6 Gy. Likewise, irradiation with carbon ions was performed with single carbon doses of 0.125, 0.5, 2 and 3 Gy. Four chemotherapeutic substances, camptothecin, gemcitabine, paclitaxel and cisplatinum, were used for single and combination experiments. The assessment of the effect of single and double treatment on cell viability was performed using the clonogenic growth assay representing the radiobiological gold standard. Results The RBE of carbon ions ranges between 3.3 and 3.9 depending on survival level and dose. All chemotherapeutic substances showed a clear does-response relationhips. in their characteristic concentrations. For subsequent combination experiments, two dose levels leading to low and medium reduction of cell survival were chosen. Combination experiments showed additive effects independently of the drugs' mechanisms of action. Paclitaxel and campthothecin demonstrated the most prominent cytotoxic effect in combination with carbon ion radiotherapy. Conclusion In conclusion, combination of carbon ion radiotherapy with chemotherapies of different mechanisms of action demonstrates additive effects. The most dominant effect was produced by paclitaxel, followed by camptothecin, as espected from previously published work. The present data serve as an important radiobiological basis for further combination experiments, as well as clinical studies on combination treatments.

  8. Effect of ion concentrations on uranium absorption from sodium carbonate solutions

    International Nuclear Information System (INIS)

    Traut, D.E.; El Hazek, N.M.T.; Palmer, G.R.; Nichols, I.L.

    1979-01-01

    The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated in order to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach solutions by ion exchange. The effects of carbonate, bicarbonate, chloride, and sulfate ions were examined. Relatively low (less than 5 g/l) concentrations of chloride, sulfate, and bicarbonate were found to be detrimental to the absorption of uranium. High (greater than 10 g/l) carbonate concentrations also adversely affected the uranium absorption. In addition, the effect of initial resin form was investigated in tests of the chloride, carbonate, and bicarbonate forms; resin form was shown to have no effect on the absorption of uranium

  9. The preferential permeation of ions across carbon and boron nitride nanotubes

    International Nuclear Information System (INIS)

    Sardroodi, Jaber Jahanbin; Azamat, Jafar; Rastkar, Alireza; Yousefnia, Negar Rad

    2012-01-01

    Highlights: ► The permeation of ions through carbon and boron nitride nanotubes has been investigated by molecular dynamics simulation. ► The considered ions have been included Ca 2+ and Cl − . ► It has been shown that the ions permeate selectively. ► The radial distribution functions and the potential of mean force of the ions have been evaluated. -- Abstract: The preferential permeation of Ca 2+ and Cl − ions across (7, 7) and (8, 8) carbon and boron nitride nanotubes have been investigated by molecular dynamics simulation method. The simulated systems composed from a carbon, or boron nitride nanotube inserted in a silicon nitride membrane immersed in the aqueous ionic solution, in the presence of an electrical field. The water structure inside nanotubes has been analyzed and the retention time of the ions, the radial distribution functions and normalized transport rate of water with respect to the number of transported ions have been calculated. The results show that the permeation of ions across the nanotubes is dependent on the diameter of the considered nanotubes. The considered nanotubes have been fixed in a silicon-nitride membrane and an external electrical field has been applied on the systems along the axis of nanotubes.

  10. Separation of uranium from sodium carbonate-sodium bicarbonate eluate by ion exchange method

    International Nuclear Information System (INIS)

    Sakane, Kohji; Hirotsu, Takahiro; Fujii, Ayako; Katoh, Shunsaku; Sugasaka, Kazuhiko

    1982-01-01

    The ion exchange method was used for separating uranium from the eluate (0.5 N Na 2 CO 3 -0.5 N NaHCO 3 ) that was obtained in the extraction process of uranium from natural sea water by using the titanium-activated carbon composite adsorbent. Uranium in the eluate containing 3 mg/l uranium was adsorbed by ion exchange resin (Amberlite IRA-400), and was eluted with the eluent (5% NaCl-0.5% Na 2 CO 3 ). The concentration ratio of uranium in the final concentrated-eluate became more than 20 times. The eluting solution to the adsorbent and the eluant to the resin could be repeatedly used in the desorption-ion exchange process. Sodium carbonate was consumed at the desorption step, and sodium bicarbonate was consumed at the ion exchange step. The concentration ratio of uranium was found to decrease as chloride ion in the eluate increased. (author)

  11. Separation of uranium from sodium carbonate - sodium bicarbonate eluate by ion exchange method

    International Nuclear Information System (INIS)

    Sakane, Kohji; Hirotsu, Takahiro; Fujii, Ayako; Katoh, Shunsaku; Sugasaka, Kazuhiko

    1982-01-01

    The ion exchange method was used for separating uranium from the eluate (0.5 N Na 2 CO 3 -0.5 N NaHCO 3 ) that was obtained in the extraction process of uranium from natural sea water by using the titanium-activated carbon composite adsorbent. Uranium in the eluate containing 3 mg/1 uranium was adsorbed by ion exchange resin (Amberlite IRA-400), and was eluted with the eluant (5 % NaCl-0.5 % Na 2 CO 3 ). The concentration ratio of uranium in the final concentrated-eluate became more than 20 times. The eluting solution to the adsorbent and the eluant to the resin could be repeatedly used in the desorption-ion exchange process. Sodium carbonate was consumed at the desorption step, and sodium bicarbonate was consumed at the ion exchange step. The concentration ratio of uranium was found to decrease as chloride ion in the eluate increased. (author)

  12. Relative clinical effectiveness of carbon ion radiotherapy. Theoretical modelling for H and N tumours

    International Nuclear Information System (INIS)

    Antonovic, Laura; Toma-Dasu, Iuliana; Dasu, Alexandru; Furusawa, Yoshiya

    2015-01-01

    Comparison of the efficiency of photon and carbon ion radiotherapy (RT) administered with the same number of fractions might be of limited clinical interest, since a wide range of fractionation patterns are used clinically today. Due to advanced photon treatment techniques, hypofractionation is becoming increasingly accepted for prostate and lung tumours, whereas patients with head and neck tumours still benefit from hyperfractionated treatments. In general, the number of fractions is considerably lower in carbon ion RT. A clinically relevant comparison would be between fractionation schedules that are optimal within each treatment modality category. In this in silico study, the relative clinical effectiveness (RCE) of carbon ions was investigated for human salivary gland tumours, assuming various radiation sensitivities related to their oxygenation. The results indicate that, for hypoxic tumours in the absence of reoxygenation, the RCE (defined as the ratio of D 50 for photons to carbon ions) ranges from 3.5 to 5.7, corresponding to carbon ion treatments given in 36 and 3 fractions, respectively, and 30 fractions for photons. Assuming that interfraction local oxygenation changes take place, results for RCE are lower than that for an oxic tumour if only a few fractions of carbon ions are used. If the carbon ion treatment is given in more than 12 fractions, the RCE is larger for the hypoxic than for the well-oxygenated tumour. In conclusion, this study showed that in silico modelling enables the study of a wide range of factors in the clinical considerations and could be an important step towards individualisation of RT treatments. (author)

  13. Chromosomal aberrations in peripheral blood lymphocytes of prostate cancer patients treated with IMRT and carbon ions

    International Nuclear Information System (INIS)

    Hartel, Carola; Nikoghosyan, Anna; Durante, Marco; Sommer, Sylwester; Nasonova, Elena; Fournier, Claudia; Lee, Ryonfa; Debus, Juergen; Schulz-Ertner, Daniela; Ritter, Sylvia

    2010-01-01

    Background and purpose: To investigate the cytogenetic damage in blood lymphocytes of patients treated for prostate cancer with different radiation qualities and target volumes. Materials and methods: Twenty patients receiving carbon-ion boost irradiation followed by IMRT or IMRT alone for the treatment of prostate cancer entered the study. Cytogenetic damage induced in peripheral blood lymphocytes of these patients was investigated at different times during the radiotherapy course using Giemsa staining and mFISH. A blood sample from each patient was taken before initiation of radiation therapy and irradiated in vitro to test for individual radiosensitivity. In addition, in vitro dose-effect curves for the induction of chromosomal exchanges by X-rays and carbon ions of different energies were measured. Results: The yield of chromosome aberrations increased during the therapy course, and the frequency was lower in patients irradiated with carbon ions as compared to patients treated with IMRT with similar target volumes. A higher frequency of aberrations was measured by increasing the target volume. In vitro, high-LET carbon ions were more effective than X-rays in inducing aberrations and yielded a higher fraction of complex exchanges. The yield of complex aberrations observed in vivo was very low. Conclusion: The investigation showed no higher aberration yield induced by treatment with a carbon-ion boost. In contrast, the reduced integral dose to the normal tissue is reflected in a lower chromosomal aberration yield when a carbon-ion boost is used instead of IMRT alone. No cytogenetic 'signature' of exposure to densely ionizing carbon ions could be detected in vivo.

  14. Copper ions removal from water using functionalized carbon nanotubes–mullite composite as adsorbent

    International Nuclear Information System (INIS)

    Tofighy, Maryam Ahmadzadeh; Mohammadi, Toraj

    2015-01-01

    Highlights: • CNTs–mullite composite was prepared via chemical vapor deposition (CVD) method. • The prepared composite was modified with concentrated nitric acid and chitosan. • The modified CNTs–mullite composites were used as novel adsorbents. • Copper ion removal from water by the prepared adsorbents was performed. • Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. - Abstract: Carbon nanotubes–mullite composite was synthesized by direct growth of carbon nanotubes on mullite particles via chemical vapor deposition method using cyclohexanol and ferrocene as carbon precursor and catalyst, respectively. The carbon nanotubes–mullite composite was oxidized with concentrated nitric acid and functionalized with chitosan and then used as a novel adsorbent for copper ions removal from water. The results demonstrated that modification with concentrated nitric acid and chitosan improves copper ions adsorption capacity of the prepared composite, significantly. Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. The carbon nanotubes growth on mullite particles to form the carbon nanotubes–mullite composite with further modification is an inherently safe approach for many promising environmental applications to avoid some concerns regarding environment, health and safety. It was found that the modified carbon nanotubes–mullite composite can be considered as an excellent adsorbent for copper ions removal from water

  15. Copper ions removal from water using functionalized carbon nanotubes–mullite composite as adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Tofighy, Maryam Ahmadzadeh; Mohammadi, Toraj, E-mail: torajmohammadi@iust.ac.ir

    2015-08-15

    Highlights: • CNTs–mullite composite was prepared via chemical vapor deposition (CVD) method. • The prepared composite was modified with concentrated nitric acid and chitosan. • The modified CNTs–mullite composites were used as novel adsorbents. • Copper ion removal from water by the prepared adsorbents was performed. • Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. - Abstract: Carbon nanotubes–mullite composite was synthesized by direct growth of carbon nanotubes on mullite particles via chemical vapor deposition method using cyclohexanol and ferrocene as carbon precursor and catalyst, respectively. The carbon nanotubes–mullite composite was oxidized with concentrated nitric acid and functionalized with chitosan and then used as a novel adsorbent for copper ions removal from water. The results demonstrated that modification with concentrated nitric acid and chitosan improves copper ions adsorption capacity of the prepared composite, significantly. Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. The carbon nanotubes growth on mullite particles to form the carbon nanotubes–mullite composite with further modification is an inherently safe approach for many promising environmental applications to avoid some concerns regarding environment, health and safety. It was found that the modified carbon nanotubes–mullite composite can be considered as an excellent adsorbent for copper ions removal from water.

  16. Advanced Electron Beam Ion Sources (EBIS) for 2-nd generation carbon radiotherapy facilities

    CERN Document Server

    Shornikov, A.

    2016-01-01

    In this work we analyze how advanced Electron Beam Ion Sources (EBIS) can facilitate the progress of carbon therapy facilities. We will demonstrate that advanced ion sources enable operation of 2-nd generation ion beam therapy (IBT) accelerators. These new accelerator concepts with designs dedicated to IBT provide beams better suited for therapy and, are more cost efficient than contemporary IBT facilities. We will give a sort overview of the existing new IBT concepts and focus on those where ion source technology is the limiting factor. We will analyse whether this limitation can be overcome in the near future thanks to ongoing EBIS development.

  17. Monte Carlo Calculations of Dose to Medium and Dose to Water for Carbon Ion Beams in Various Media

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Petersen, Jørgen B.B.; Jäkel, Oliver

    treatment plans. Here, we quantisize the effect of dose to water vs. dose to medium for a series of typical target materials found in medical physics. 2     Material and Methods The Monte Carlo code FLUKA [Battistioni et al. 2007] is used to simulate the particle fluence spectrum in a series of target...... materials exposed to carbon ion beams. The scored track-length fluence spectrum Φi for a given particle i at the energy E, is multiplied with the mass stopping power for target material for calculating Dm . Similarly, Dw is calculated by multiplying the same fluence spectrum with the mass stopping power...... the PSTAR, ASTAR stopping power routines available at NIST1 and MSTAR2 provided by H. Paul et al. 3     Results For a pristine carbon ion beam we encountered a maximum deviation between Dw and Dm up to 8% for bone. In addition we investigate spread out Bragg peak configurations which dilutes the effect...

  18. Surface modifications of polypropylene by high energy carbon ions

    International Nuclear Information System (INIS)

    Saha, A.; Chakraborty, V.; Dutta, R.K.; Chintalapudi, S.N.

    2000-01-01

    Polypropylene was irradiated with 12 C ions of 3.6 and 5.4 MeV energies using 3 MV tandem accelerator. The surface modification was investigated by Scanning Electron Microscopy (SEM). Optical changes were monitored by UV-VIS and FTIR spectroscopy. At the lowest ion fluence, only blister formation of various sizes (1-6 μm) was observed. Polymer when irradiated at a fluence of 1x10 14 ions/cm 2 exhibited a network structure. A comparative study on dose dependence of surface and bulk modification has been described. (author)

  19. Cumulative approaches to track formation under swift heavy ion (SHI) irradiation: Phenomenological correlation with formation energies of Frenkel pairs

    International Nuclear Information System (INIS)

    Crespillo, M.L.; Agulló-López, F.; Zucchiatti, A.

    2017-01-01

    Highlights: • Extensive survey formation energies Frenkel pairs and electronic stopping thresholds. • Correlation: track formation thresholds and the energies for Frenkel pair formation. • Formation energies Frenkel pairs discussed in relation to the cumulative mechanisms. • Amorphous track formation mechanisms: defect accumulation models versus melting. • Advantages cumulative models to deal with new hot topics: nuclear-electronic synergy. - Abstract: An extensive survey for the formation energies of Frenkel pairs, as representative candidates for radiation-induced point defects, is presented and discussed in relation to the cumulative mechanisms (CM) of track formation in dielectric materials under swift heavy ion (SHI) irradiation. These mechanisms rely on the generation and accumulation of point defects during irradiation followed by collapse of the lattice once a threshold defect concentration is reached. The physical basis of those approaches has been discussed by Fecht as a defect-assisted transition to an amorphous phase. Although a first quantitative analysis of the CM model was previously performed for LiNbO 3 crystals, we have, here, adopted a broader phenomenological approach. It explores the correlation between track formation thresholds and the energies for Frenkel pair formation for a broad range of materials. It is concluded that the threshold stopping powers can be roughly scaled with the energies required to generate a critical Frenkel pair concentration in the order of a few percent of the total atomic content. Finally, a comparison with the predictions of the thermal spike model is discussed within the analytical Szenes approximation.

  20. Cumulative approaches to track formation under swift heavy ion (SHI) irradiation: Phenomenological correlation with formation energies of Frenkel pairs

    Energy Technology Data Exchange (ETDEWEB)

    Crespillo, M.L., E-mail: mcrespil@utk.edu [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Department of Materials Science & Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Agulló-López, F., E-mail: fal@uam.es [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Zucchiatti, A. [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain)

    2017-03-01

    Highlights: • Extensive survey formation energies Frenkel pairs and electronic stopping thresholds. • Correlation: track formation thresholds and the energies for Frenkel pair formation. • Formation energies Frenkel pairs discussed in relation to the cumulative mechanisms. • Amorphous track formation mechanisms: defect accumulation models versus melting. • Advantages cumulative models to deal with new hot topics: nuclear-electronic synergy. - Abstract: An extensive survey for the formation energies of Frenkel pairs, as representative candidates for radiation-induced point defects, is presented and discussed in relation to the cumulative mechanisms (CM) of track formation in dielectric materials under swift heavy ion (SHI) irradiation. These mechanisms rely on the generation and accumulation of point defects during irradiation followed by collapse of the lattice once a threshold defect concentration is reached. The physical basis of those approaches has been discussed by Fecht as a defect-assisted transition to an amorphous phase. Although a first quantitative analysis of the CM model was previously performed for LiNbO{sub 3} crystals, we have, here, adopted a broader phenomenological approach. It explores the correlation between track formation thresholds and the energies for Frenkel pair formation for a broad range of materials. It is concluded that the threshold stopping powers can be roughly scaled with the energies required to generate a critical Frenkel pair concentration in the order of a few percent of the total atomic content. Finally, a comparison with the predictions of the thermal spike model is discussed within the analytical Szenes approximation.

  1. Tracking bio-hydrogen-mediated production of commodity chemicals from carbon dioxide and renewable electricity.

    Science.gov (United States)

    Puig, Sebastià; Ganigué, Ramon; Batlle-Vilanova, Pau; Balaguer, M Dolors; Bañeras, Lluís; Colprim, Jesús

    2017-03-01

    This study reveals that reduction of carbon dioxide (CO 2 ) to commodity chemicals can be functionally compartmentalized in bioelectrochemical systems. In the present example, a syntrophic consortium composed by H 2 -producers (Rhodobacter sp.) in the biofilm is combined with carboxidotrophic Clostridium species, mainly found in the bulk liquid. The performance of these H 2 -mediated electricity-driven systems could be tracked by the activity of a biological H 2 sensory protein identified at cathode potentials between -0.2V and -0.3V vs SHE. This seems to point out that such signal is not strain specific, but could be detected in any organism containing hydrogenases. Thus, the findings of this work open the door to the development of a biosensor application or soft sensors for monitoring such systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Tracking the Path of Carbon from Plants to Rhizobiomes using Protein Stable Isotope Probing

    Science.gov (United States)

    Lipton, M. S.; Nicora, C.; Shaw, J. B.; Karaoz, U.; Nuccio, E. E.; Zhalnina, K.; Paša-Tolić, L.; Brodie, E.; Pett-Ridge, J.; Firestone, M.

    2016-12-01

    Plants and microorganisms have complex relationships that mediate terrestrial carbon fluxes. Understanding the functional roles of belowground biotic communities and their interactions with plant roots is critical to understanding the fate of plant carbon in soil. Currently many `omics-driven technologies reveal only a static snap shot of functionality in biological communities, but temporally-resolved tools are necessary describe biological processes that change and evolve over time. Stable isotope probing (SIP) experiments are temporal in nature, and can track the flow of carbon from the atmosphere through the plant and into the soil microbial community through space and time, and ultimately reveal both plant-microbe interactions and the fate of the carbon within the system. The combination of 'omics approaches with SIP allows us to selectively target and characterize metabolically active organisms in a community, and elucidate functional potential over time-scales relevant to biological processes. Protein stable isotope probing (Pro-SIP) offers a unique perspective into the interaction between plants and microbial communities, and potentially links taxonomic, functional and metabolic information. We developed a Pro-SIP approach amenable for use in soil systems using soils collected from an annual grassland in Northern CA amended with 13C labeled glucose. Using this approach we determined the overall proteomic profile and recently synthesized proteins within the plant-associated microbial community. The mass spectrometric analysis of the proteins extracted from the soil identified over 60,000 proteins that correspond to about 2200 protein functions. Of these functions, over 500 were found to contain a labeled peptide. Proteins related to glucose metabolism, carbohydrate storage, sugar transport and sulfur metabolism were found to be actively synthesized after glucose amendment. In systems where plants were grown with 13CO2 revealed synthesis of central metabolism

  3. Facile synthesis of carbon dot and residual carbon nanobeads: Implications for ion sensing, medicinal and biological applications.

    Science.gov (United States)

    Gaddam, Rohit Ranganathan; Mukherjee, Sudip; Punugupati, Neelambaram; Vasudevan, D; Patra, Chitta Ranjan; Narayan, Ramanuj; Vsn Kothapalli, Raju

    2017-04-01

    Synthesis of carbon dots (Cdots) via chemical route involves disintegration of carbon materials into nano-domains, wherein, after extraction of Cdots, the remaining carbon material is discarded. The present work focuses on studying even the leftover carbon residue namely, carbon nanobeads (CNBs) as an equally important material for applications on par with that of carbon dot. It employs oxidative treatment of carbonised gum olibanum resin (GOR) to produce the carbons namely Cdots and CNBs (as the residue). The Cdots (~5-10nm) exhibit blue-green fluorescence with an optical absorption at ~300nm unlike the CNBs (40-50nm) which fail to exhibit fluorescence. The fluorescence behaviour exhibited by Cdots were utilized for heavy metal ion sensing of Pb 2+ , Hg 2+ and Cd 2+ ions in aqueous media. Interestingly, both Cdots and CNBs are biocompatible to normal cell lines but cytotoxic to cancer cell lines, observed during several in vitro experiments (cell viability assay, cell cycle assay, apoptosis assay, ROS determination assay, caspase-9 activity assay). Additionally, Cdots exhibit bright green fluorescence in B16F10 cells. The Cdots and CNB's demonstrate multifunctional activities (sensor, cellular imaging and cancer therapy) in biomedical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Modified granular activated carbon: A carrier for the recovery of nickel ions from aqueous wastes

    Energy Technology Data Exchange (ETDEWEB)

    Satapathy, D.; Natarajan, G.S.; Sen, R. [Central Fuel Research Inst., Nagpur (India)

    2004-07-01

    Granular Activated Carbon (GAC) is widely used for the removal and recovery of toxic pollutants including metals because of its low cost and high affinity towards the scavenging of metal ions. Activated carbon derived from bituminous coal is preferred for wastewater treatment due to its considerable hardness, a characteristic needed to keep down handling losses during re-activation. Commercial grade bituminous coal based carbon, viz. Filtrasorb (F-400), was used in the present work. The scavenging of precious metals such as nickel onto GAC was studied and a possible attempt made to recover the adsorbed Ni{sup 2+} ions through the use of some suitable leaching processes. As part of the study, the role of complexing agents on the surface of the carbon was also investigated. The use of organic complexing agents such as oxine and 2-methyloxine in the recovery process was found to be promising. In addition, the surface of the carbon was modified with suitable oxidising agents that proved to be more effective than chelating agents. Several attempts were made to optimise the recovery of metal ions by carrying out experiments with oxidising agents in order to obtain maximum recovery from the minimum quantity of carbon. Experiments with nitric acid indicated that not only was the carbon surface modified but such modification also helped in carbon regeneration.

  5. Detecting carbon uptake and cellular allocation by individual algae in multispecies assemblages: Tracking carbon into single algal cells

    Energy Technology Data Exchange (ETDEWEB)

    Murdock, Justin N. [USDA Agricultural Research Service, National Sedimentation Laboratory, Oxford Mississippi; Department of Biology, Tennessee Technological University, Cookeville Tennessee

    2015-11-03

    Algal species vary in carbon (C) need and uptake rates. Understanding differences in C uptake and cellular allocation among species from natural communities will bring new insight into many ecosystem process questions including how species changes will alter energy availability and C sequestration in aquatic ecosystems. A major limitation of current methods that measure algal C incorporation is the inability to separate the response of individual species from mixed-species assemblages. I used Fourier-transform infrared microspectroscopy to qualitatively measure inorganic 13C isotope incorporation into individual algal cells in single species, two species, and natural phytoplankton assemblages. Lateral shifts in spectral peaks from 13C treatments were observed in all species. Comparison of peaks associated with carbohydrates, proteins, and lipids allowed for the detection of which individuals took in C, and which macromolecules the C was used to make. For example, shifts in Spirogyra spectral peaks showed substantial C incorporation in carbohydrates. Further, shifts in peaks at 1160 cm-1, 1108 cm-1, 1080 cm-1, 1048 cm-1, and 1030 cm-1 suggested C was being allocated into cellulose. The natural phytoplankton assemblage demonstrated how C could be tracked into co-occurring species. A diatom had large shifts in protein and carbohydrate peaks, while a green alga and euglenoid had only a few shifts in protein related peaks. Fourier-transform infrared microspectroscopy is an established, label free method for measuring the chemical composition of algal cells. However, adding a label such as 13C isotope can greatly expand the technique's capabilities by qualitatively tracking C movement between inorganic and organic states within single cells.

  6. Performance of Novel Randomly Oriented High Graphene Carbon in Lithium Ion Capacitors

    Directory of Open Access Journals (Sweden)

    Rahul S. Kadam

    2018-01-01

    Full Text Available The structure of carbon material comprising the anode is the key to the performance of a lithium ion capacitor. In addition to determining the capacity, the structure of the carbon material also determines the diffusion rate of the lithium ion into the anode which in turn controls power density which is vital in high rate applications. This paper covers details of systematic investigation of the performance of a structurally novel carbon, called Randomly Oriented High Graphene (ROHG carbon, and graphite in a high rate application device, that is, lithium ion capacitor. Electrochemical impedance spectroscopy shows that ROHG is less resistive and has faster lithium ion diffusion rates (393.7 × 10−3 S·s(1/2 compared to graphite (338.1 × 10−3 S·s(1/2. The impedance spectroscopy data is supported by the cell data showing that the ROHG carbon based device has energy density of 22.8 Wh/l with a power density of 4349.3 W/l, whereas baseline graphite based device has energy density of 5 Wh/l and power density of 4243.3 W/l. This data clearly shows advantage of the randomly oriented graphene platelet structure of ROHG in lithium ion capacitor performance.

  7. Effects of beer administration in mice on acute toxicities induced by X rays and carbon ions

    International Nuclear Information System (INIS)

    Monobe, Manami

    2003-01-01

    We have investigated the tissue specificity of radioprotection by beer, which was previously found for human lymphocytes. C3H/He female mice, aged 14 weeks, received an oral administration of beer, ethanol or saline at a dose of 1 ml/mouse 30 min before whole-body irradiation with 137 Cs γ rays or 50 keV/μm carbon ions. The dicentrics of chromosome aberrations in spleen cells were significantly (p 0 (slope of a dose-survival curve) for γ rays and carbon ions as well. Beer administration significantly (p 50/30 (radiation dose required to kill 50% of mice within 30 days) for γ rays and carbon ions. Ethanol-administration also significantly (p 50/30 value for γ rays, but not for carbon ions. It is concluded that beer administration reduces the radiation injury caused by photons and carbon ions, depending on the tissue type. Radioprotection by beer administration is not solely due to OH radical-scavenging action by the ethanol contained in beer. (author)

  8. Enhanced Lithium- and Sodium-Ion Storage in an Interconnected Carbon Network Comprising Electronegative Fluorine.

    Science.gov (United States)

    Hong, Seok-Min; Etacheri, Vinodkumar; Hong, Chulgi Nathan; Choi, Seung Wan; Lee, Ki Bong; Pol, Vilas G

    2017-06-07

    Fluorocarbon (C x F y ) anode materials were developed for lithium- and sodium-ion batteries through a facile one-step carbonization of a single precursor, polyvinylidene fluoride (PVDF). Interconnected carbon network structures were produced with doped fluorine in high-temperature carbonization at 500-800 °C. The fluorocarbon anodes derived from the PVDF precursor showed higher reversible discharge capacities of 735 mAh g -1 and 269 mAh g -1 in lithium- and sodium-ion batteries, respectively, compared to the commercial graphitic carbon. After 100 charge/discharge cycles, the fluorocarbon showed retentions of 91.3% and 97.5% in lithium (at 1C) and sodium (at 200 mA g -1 ) intercalation systems, respectively. The effects of carbonization temperature on the electrochemical properties of alkali metal ion storage were thoroughly investigated and documented. The specific capacities in lithium- and sodium-ion batteries were dependent on the fluorine content, indicating that the highly electronegative fluorine facilitates the insertion/extraction of lithium and sodium ions in rechargeable batteries.

  9. 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.

  10. Mesoporous activated carbon from corn stalk core for lithium ion batteries

    Science.gov (United States)

    Li, Yi; Li, Chun; Qi, Hui; Yu, Kaifeng; Liang, Ce

    2018-04-01

    A novel mesoporous activated carbon (AC) derived from corn stalk core is prepared via a facile and effective method which including the decomposition and carbonization of corn stalk core under an inert gas atmosphere and further activation process with KOH solution. The mesoporous activated carbon (AC) is characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) measurements. These biomass waste derived from activated carbon is proved to be promising anode materials for high specific capacity lithium ion batteries. The activated carbon anode possesses excellent reversible capacity of 504 mAh g-1 after 100 cycles at 0.2C. Compared with the unactivated carbon (UAC), the electrochemical performance of activated carbon is significantly improved due to its mesoporous structure.

  11. The effect of Argon ion irradiation on the thickness and structure of ultrathin amorphous carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Xie, J.; Komvopoulos, K., E-mail: kyriakos@me.berkeley.edu [Department of Mechanical Engineering, University of California, Berkeley, California 94720 (United States)

    2016-03-07

    Carbon films synthesized by plasma-enhanced chemical vapor deposition (PECVD) and filtered cathodic vacuum arc (FCVA) exhibit a layered structure consisting of a bottom (interface) and a top (surface) layer rich in sp{sup 2} atomic carbon bonding and a middle (bulk) layer of much higher sp{sup 3} content. Because of significant differences in the composition, structure, and thickness of these layers, decreasing the film thickness may negatively affect its properties. In this study, transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) were used to examine the effect of Ar{sup +} ion irradiation on the structure and thickness of ultrathin films of hydrogenated amorphous carbon (a-C:H) and hydrogen-free amorphous carbon (a-C) deposited by PECVD and FCVA, respectively. The TEM and EELS results show that 2-min ion irradiation decreases the film thickness without markedly changing the film structure and composition, whereas 4-min ion irradiation results in significant film thinning and a moderate decrease of the sp{sup 3} content of the bulk layer. This study demonstrates that Ar{sup +} ion irradiation is an effective post-deposition process for reducing the thickness and tuning the structure of ultrathin carbon films. This capability has direct implications in the synthesis of ultrathin protective carbon overcoats for extremely high-density magnetic recording applications.

  12. Effects of ion implantation on the electrochemical characteristics of carbon electrodes

    International Nuclear Information System (INIS)

    Takahashi, Katsuo; Iwaki, Masaya

    1994-01-01

    Various carbon materials are important electrode materials for electrochemical field. By ion implantation, the surface layer reforming of carbon materials (mainly galssy carbon) was carried out, and the effect that it exerts to their electrode characteristics was investigated. As the results of the ion implantation of Li, N, O, K, Ti, Zn, Cd and others performed so far, it was found that mainly by the change of the surface layer to amorphous state, there were the effects of the lowering of base current and the lowering of electrode reaction rate, and it was known that the surface layers of carbon materials doped with various kinds of ions showed high chemical stability. The use of carbon materials as electrodes in electrochemistry is roughly divided into the electrodes for electrolytic industry and fuel cells for large current and those for the measurement in electrochemical reaction for small current. The structure of carbon materials and electrode characteristics, and the reforming effect by ion implantation are reported. (K.I.)

  13. Carbon nanotube: nanodiamond Li-ion battery cathodes with increased thermal conductivity

    Science.gov (United States)

    Salgado, Ruben; Lee, Eungiee; Shevchenko, Elena V.; Balandin, Alexander A.

    2016-10-01

    Prevention of excess heat accumulation within the Li-ion battery cells is a critical design consideration for electronic and photonic device applications. Many existing approaches for heat removal from batteries increase substantially the complexity and overall weight of the battery. Some of us have previously shown a possibility of effective passive thermal management of Li-ion batteries via improvement of thermal conductivity of cathode and anode material1. In this presentation, we report the results of our investigation of the thermal conductivity of various Li-ion cathodes with incorporated carbon nanotubes and nanodiamonds in different layered structures. The cathodes were synthesized using the filtration method, which can be utilized for synthesis of commercial electrode-active materials. The thermal measurements were conducted with the "laser flash" technique. It has been established that the cathode with the carbon nanotubes-LiCo2 and carbon nanotube layered structure possesses the highest in-plane thermal conductivity of 206 W/mK at room temperature. The cathode containing nanodiamonds on carbon nanotubes structure revealed one of the highest cross-plane thermal conductivity values. The in-plane thermal conductivity is up to two orders-of-magnitude greater than that in conventional cathodes based on amorphous carbon. The obtained results demonstrate a potential of carbon nanotube incorporation in cathode materials for the effective thermal management of Li-ion high-powered density batteries.

  14. Biophysical calculations of cell killing probability by the amorphous track structure model for heavy-ion beams

    International Nuclear Information System (INIS)

    Kase, Yuki; Matsufuji, Naruhiro; Furusawa, Yoshiya; Kanai, Tatsuaki

    2007-01-01

    In a treatment planning of heavy-ion radiotherapy, it is necessary to estimate the biological effect of the heavy-ion beams. Physical dose should be associated with the relative biological effectiveness (RBE) at each point. Presently, carbon ion radiotherapy has been carried out at the National Institute Radiological Sciences (NIRS) in Japan and the Gesellschaft fuer Schwerionenforschung mbH (GSI) in Germany. Both facilities take individual approach for the calculation of the RBE value. At NIRS, the classical LQ model has been used while the local effect model (LEM) has been incorporated into the treatment planning system at GSI. The first aim of this study is to explain the RBE model of NIRS by the microdosimetric kinetic model (MKM). In addition, the clarification of similarities and differences between the MKM and the LEM was also investigated. (author)

  15. Pilot production of track etch membranes (TEMS) using heavy ion beam scanner

    International Nuclear Information System (INIS)

    Nair, J.P.; Surendran, P.; Sparrow, Hillary; Ninawe, N.G.; Bhagwat, P.V.; Acharya, N.; Kulshreshta, V.; Rajesh Kumar; Vijay, Y.K.; Kurup, M.B.

    2005-01-01

    Various methods for making TEMs were conducted at Pelletron Accelerator Facility. The technique for production using ion beam scattering was also established. This is an effort to make TEMs on pilot basis at BARC- TIFR Pelletron Accelerator using Heavy Ion Beam Scanner till large rolling mechanism is implemented

  16. Electron capture from a metal surface by slow, multicharged aluminum and carbon ions

    International Nuclear Information System (INIS)

    Hughes, R.H.; Miller, R.D.; Wattuhewa, G.; Ye, X.M.; Pederson, D.O.

    1989-01-01

    A time-of-flight technique has been used to measure residual charge in the scattering of laser-produced pulses of C/sup k+/ (k=1 to 4) and Al/sup m+/ (m=2 to 5) ions from a well-outgassed amorphous gold-iridium surface under UHV conditions (2 x 10/sup -9/ Torr). Ions incident at 7 degree to the surface were specularly reflected. The analysis showed the survival of singly charged ions in the case of scattering 300-, 400-, and 500-eV/charge Al ions with neutrals representing the majority species. This is equivalent to a kinetic energy in a direction transverse to the surface of 4.5, 5.9, and 7.4 eV/charge, respectively, which ensures only minimal surface penetration. In the case of 280-eV/charge carbon ions, only neutrals were detected. No residual ions were detected in either Al or C ions scattered through an angle of deviation equal to or greater than 45 degree within experimental error. In a separate experiment no residual ions were detected in the case of 400-eV/charge Al ions incident at 22.5 degree to a gold surface and specularly reflected. The results are explained in terms of Auger neutralization of the multicharged ions on the incoming pass and resonance ionization and neutralization of low-charge-state ions that emerge from the surface and change their charge on the outgoing pass. Under near adiabatic conditions, no residual charge is expected for either the aluminum or carbon projectiles. The presence of Al + undergrazing-incidence and specular reflection is analyzed and discussed in terms of the nonadiabatic behavior of Al + ions emerging from the surface

  17. Chemical modification of polypropylene induced by high energy carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Saha, A.; Chakraborty, V.; Chintalapudi, S.N. E-mail: snc@gamma.iuc.res.in

    2000-06-01

    Polypropylene was irradiated with {sup 12}C{sup +} ions of 3.6 and 5.4 MeV energy using 3 MV Pelletron. The spectral changes owing to ion bombardment were investigated by UV-VIS and Fourier-transform infrared (FTIR) spectroscopy. A gradual increase in absorbance was observed around visible and near visible region with increase in fluence of bombarding ions. The difference absorption spectra show formation of chromophoric groups with wavelength maximum near 380 nm at lower fluence, but at high fluence a shift in peak is observed. The chromophoric groups are likely to be the extended conjugated polyene system and the red shift in peak position at high fluence may be attributed to the greater degree of conjugation. The formation of unsaturated linkage is confirmed by the FTIR spectra with observed stretching band around 1650 cm{sup -1} and its intensity was found to increase with increase in ion fluence studied. The gases (in the range 2-80 amu) which were evolved due to interaction of polypropylene with {sup 12}C{sup +} ions were measured with Residual Gas Analyzer (RGA). A large number of gaseous components were detected. This shows that polymer chains break into some smaller fragments which concomitantly leads to extended conjugation.

  18. Structural phenomena in glassy carbon induced by cobalt ion implantation

    Czech Academy of Sciences Publication Activity Database

    Lavrentiev, Vasyl; Vacík, Jiří; Naramoto, H.

    2008-01-01

    Roč. 92, č. 3 (2008), s. 673-680 ISSN 0947-8396. [15th International Conference on Vacuum Ultraviolet Radiation Physics. Berlin, 29.07.2007-03.08.2007] Institutional research plan: CEZ:AV0Z10480505 Keywords : DIAMOND-LIKE CARBON * AMORPHOUS-CARBON * RAMAN-SCATTERING Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.884, year: 2008

  19. Clinical oxygen enhancement ratio of tumors in carbon ion radiotherapy: the influence of local oxygenation changes

    DEFF Research Database (Denmark)

    Antonovic, Laura; Lindblom, Emely; Dasu, Alexandru

    2014-01-01

    The effect of carbon ion radiotherapy on hypoxic tumors has recently been questioned because of low linear energy transfer (LET) values in the spread-out Bragg peak (SOBP). The aim of this study was to investigate the role of hypoxia and local oxygenation changes (LOCs) in fractionated carbon ion...... radiotherapy. Three-dimensional tumors with hypoxic subvolumes were simulated assuming interfraction LOCs. Different fractionations were applied using a clinically relevant treatment plan with a known LET distribution. The surviving fraction was calculated, taking oxygen tension, dose and LET into account...... to LOCs did not compensate for the increase in total dose required for tumor control. In conclusion, our results suggest that hypoxia can influence the outcome of carbon ion radiotherapy because of the non-negligible oxygen effect at the low LETs in the SOBP. However, if LOCs occur, a relatively high...

  20. Benchmarking nuclear models of FLUKA and GEANT4 for carbon ion therapy

    CERN Document Server

    Bohlen, TT; Quesada, J M; Bohlen, T T; Cerutti, F; Gudowska, I; Ferrari, A; Mairani, A

    2010-01-01

    As carbon ions, at therapeutic energies, penetrate tissue, they undergo inelastic nuclear reactions and give rise to significant yields of secondary fragment fluences. Therefore, an accurate prediction of these fluences resulting from the primary carbon interactions is necessary in the patient's body in order to precisely simulate the spatial dose distribution and the resulting biological effect. In this paper, the performance of nuclear fragmentation models of the Monte Carlo transport codes, FLUKA and GEANT4, in tissue-like media and for an energy regime relevant for therapeutic carbon ions is investigated. The ability of these Monte Carlo codes to reproduce experimental data of charge-changing cross sections and integral and differential yields of secondary charged fragments is evaluated. For the fragment yields, the main focus is on the consideration of experimental approximations and uncertainties such as the energy measurement by time-of-flight. For GEANT4, the hadronic models G4BinaryLightIonReaction a...

  1. Electrochemically Controlled Ion-exchange Property of Carbon Nanotubes/Polypyrrole Nanocomposite in Various Electrolyte Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Daiwon [Pacific Northwest National Laboratory, 902 Battelle Boulevard P.O. Box 999 Richland WA 99352 USA; Zhu, Chengzhou [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 United States; Fu, Shaofang [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 United States; Du, Dan [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 United States; Engelhard, Mark H. [Pacific Northwest National Laboratory, 902 Battelle Boulevard P.O. Box 999 Richland WA 99352 USA; Lin, Yuehe [Pacific Northwest National Laboratory, 902 Battelle Boulevard P.O. Box 999 Richland WA 99352 USA; School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920 United States

    2016-09-15

    The electrochemically controlled ion-exchange properties of multi-wall carbon nanotube (MWNT)/electronically conductive polypyrrole (PPy) polymer composite in the various electrolyte solutions have been investigated. The ion-exchange behavior, rate and capacity of the electrochemically deposited polypyrrole with and without carbon nanotube (CNT) were compared and characterized using cyclic voltammetry (CV), chronoamperometry (CA), electrochemical quartz crystal microbalance (EQCM), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It has been found that the presence of carbon nanotube backbone resulted in improvement in ion-exchange rate, stability of polypyrrole, and higher anion loading capacity per PPy due to higher surface area, electronic conductivity, porous structure of thin film, and thinner film thickness providing shorter diffusion path. Chronoamperometric studies show that electrically switched anion exchange could be completed more than 10 times faster than pure PPy thin film. The anion selectivity of CNT/PPy film is demonstrated using X-ray photoelectron spectroscopy (XPS).

  2. Determination of low-energy ion-induced electron yields from thin carbon foils

    International Nuclear Information System (INIS)

    Allegrini, Frederic; Wimmer-Schweingruber, Robert F.; Wurz, Peter; Bochsler, Peter

    2003-01-01

    Ion beams crossing thin carbon foils can cause electron emission from the entrance and exit surface. Thin carbon foils are used in various types of time-of-flight (TOF) mass spectrometers to produce start pulses for TOF measurements. The yield of emitted electrons depends, among other parameters, on the energy of the incoming ion and its mass, and it has been experimentally determined for a few projectile elements. The electron emission yield is of great importance for deriving abundance ratios of elements and isotopes in space plasmas using TOF mass spectrometers. We have developed a detector for measuring ion-induced electron yields, and we have extended the electron yield measurements for oxygen to energies relevant for solar wind research. We also present first measurements of the carbon foil electron emission yield for argon and iron in the solar wind energy range

  3. Influence of nuclear interactions in polyethylene range compensators for carbon-ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kanematsu, Nobuyuki, E-mail: nkanemat@nirs.go.jp; Koba, Yusuke; Ogata, Risa [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Himukai, Takeshi [Ion Beam Therapy Center, SAGA HIMAT Foundation, 415 Harakoga-machi, Tosu, Saga 841-0071 (Japan)

    2014-07-15

    Purpose: A recent study revealed that polyethylene (PE) would cause extra carbon-ion attenuation per range shift by 0.45%/cm due to compositional differences in nuclear interactions. The present study aims to assess the influence of PE range compensators on tumor dose in carbon-ion radiotherapy. Methods: Carbon-ion radiation was modeled to be composed of primary carbon ions and secondary particles, for each of which the dose and the relative biological effectiveness (RBE) were estimated at a tumor depth in the middle of spread-out Bragg peak. Assuming exponential behavior for attenuation and yield of these components with depth, the PE effect on dose was calculated for clinical carbon-ion beams and was partly tested by experiment. The two-component model was integrated into a treatment-planning system and the PE effect was estimated in two clinical cases. Results: The attenuation per range shift by PE was 0.1%–0.3%/cm in dose and 0.2%–0.4%/cm in RBE-weighted dose, depending on energy and range-modulation width. This translates into reduction of RBE-weighted dose by up to 3% in extreme cases. In the treatment-planning study, however, the effect on RBE-weighted dose to tumor was typically within 1% reduction. Conclusions: The extra attenuation of primary carbon ions in PE was partly compensated by increased secondary particles for tumor dose. In practical situations, the PE range compensators would normally cause only marginal errors as compared to intrinsic uncertainties in treatment planning, patient setup, beam delivery, and clinical response.

  4. Radiative Double Electron Capture in Collisions of O8+ Ions with Carbon

    Science.gov (United States)

    Simon, A.; Warczak, A.; Elkafrawy, T.; Tanis, J. A.

    2010-03-01

    Multielectron capture processes observed in low energy collisions of bare ions with target atoms open insight into electron correlations in electromagnetic fields. Radiative double electron capture (RDEC) provides the simplest tool for investigation of such processes. Here, the experimental observation of the RDEC process in collisions of O8+ ions with thin carbon films is presented and the RDEC cross section value obtained is compared with recent theoretical calculations.

  5. Robotic-based carbon ion therapy and patient positioning in 6 degrees of freedom: setup accuracy of two standard immobilization devices used in carbon ion therapy and IMRT.

    Science.gov (United States)

    Jensen, Alexandra D; Winter, Marcus; Kuhn, Sabine P; Debus, Jürgen; Nairz, Olaf; Münter, Marc W

    2012-03-29

    To investigate repositioning accuracy in particle radiotherapy in 6 degrees of freedom (DOF) and intensity-modulated radiotherapy (IMRT, 3 DOF) for two immobilization devices (Scotchcast masks vs thermoplastic head masks) currently in use at our institution for fractionated radiation therapy in head and neck cancer patients. Position verifications in patients treated with carbon ion therapy and IMRT for head and neck malignancies were evaluated. Most patients received combined treatment regimen (IMRT plus carbon ion boost), immobilization was achieved with either Scotchcast or thermoplastic head masks. Position corrections in robotic-based carbon ion therapy allowing 6 DOF were compared to IMRT allowing corrections in 3 DOF for two standard immobilization devices. In total, 838 set-up controls of 38 patients were analyzed. Robotic-based position correction including correction of rotations was well tolerated and without discomfort. Standard deviations of translational components were between 0.5 and 0.8 mm for Scotchcast and 0.7 and 1.3 mm for thermoplastic masks in 6 DOF and 1.2-1.4 mm and 1.0-1.1 mm in 3 DOF respectively. Mean overall displacement vectors were between 2.1 mm (Scotchcast) and 2.9 mm (thermoplastic masks) in 6 DOF and 3.9-3.0 mm in 3 DOF respectively. Displacement vectors were lower when correction in 6 DOF was allowed as opposed to 3 DOF only, which was maintained at the traditional action level of >3 mm for position correction in the pre-on-board imaging era. Setup accuracy for both systems was within the expected range. Smaller shifts were required when 6 DOF were available for correction as opposed to 3 DOF. Where highest possible positioning accuracy is required, frequent image guidance is mandatory to achieve best possible plan delivery and maintenance of sharp gradients and optimal normal tissue sparing inherent in carbon ion therapy.

  6. Robotic-based carbon ion therapy and patient positioning in 6 degrees of freedom: setup accuracy of two standard immobilization devices used in carbon ion therapy and IMRT

    Science.gov (United States)

    2012-01-01

    Purpose To investigate repositioning accuracy in particle radiotherapy in 6 degrees of freedom (DOF) and intensity-modulated radiotherapy (IMRT, 3 DOF) for two immobilization devices (Scotchcast masks vs thermoplastic head masks) currently in use at our institution for fractionated radiation therapy in head and neck cancer patients. Methods and materials Position verifications in patients treated with carbon ion therapy and IMRT for head and neck malignancies were evaluated. Most patients received combined treatment regimen (IMRT plus carbon ion boost), immobilization was achieved with either Scotchcast or thermoplastic head masks. Position corrections in robotic-based carbon ion therapy allowing 6 DOF were compared to IMRT allowing corrections in 3 DOF for two standard immobilization devices. In total, 838 set-up controls of 38 patients were analyzed. Results Robotic-based position correction including correction of rotations was well tolerated and without discomfort. Standard deviations of translational components were between 0.5 and 0.8 mm for Scotchcast and 0.7 and 1.3 mm for thermoplastic masks in 6 DOF and 1.2 - 1.4 mm and 1.0 - 1.1 mm in 3 DOF respectively. Mean overall displacement vectors were between 2.1 mm (Scotchcast) and 2.9 mm (thermoplastic masks) in 6 DOF and 3.9 - 3.0 mm in 3 DOF respectively. Displacement vectors were lower when correction in 6 DOF was allowed as opposed to 3 DOF only, which was maintained at the traditional action level of > 3 mm for position correction in the pre-on-board imaging era. Conclusion Setup accuracy for both systems was within the expected range. Smaller shifts were required when 6 DOF were available for correction as opposed to 3 DOF. Where highest possible positioning accuracy is required, frequent image guidance is mandatory to achieve best possible plan delivery and maintenance of sharp gradients and optimal normal tissue sparing inherent in carbon ion therapy. PMID:22458824

  7. Recent progress of a superconducting rotating-gantry for carbon-ion radiotherapy

    Science.gov (United States)

    Iwata, Y.; Fujimoto, T.; Matsuba, S.; Fujita, T.; Sato, S.; Furukawa, T.; Hara, Y.; Mizushima, K.; Saraya, Y.; Tansho, R.; Saotome, N.; Shirai, T.; Noda, K.

    2017-09-01

    A superconducting rotating-gantry for carbon-ion radiotherapy was developed. This isocentric rotating gantry can transport carbon ions having the maximum kinetic energy of E = 430 MeV/u to an isocenter with irradiation angles of over ±180°, and is further capable of performing three-dimensional raster-scanning irradiation. By using combined-function superconducting magnets, we could design a compact rotating gantry for carbon-ion radiotherapy. Construction of the gantry structure began since early 2014, and the installation of the entire gantry system to the Heavy Ion Medical Accelerator in Chiba (HIMAC) complex was completed by the end of September, 2015. Beam tuning subsequently began since October, 2015, and carbon ions, as accelerated by the HIMAC upper synchrotron, having kinetic energies of between E = 430-48 MeV/u were successfully transported with the rotating gantry to the isocenter. The size and shape of the beam spots at the isocenter is being tuned over various combinations of the beam energies and the gantry angle. We will present the recent progress as well as the current status of the superconducting rotating-gantry.

  8. Manipulating Adsorption-Insertion Mechanisms in Nanostructured Carbon Materials for High-Efficiency Sodium Ion Storage

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Shen [College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072 China; Xiao, Lifen [College of Chemistry, Central China Normal University, Wuhan 430079 China; Pacific Northwest National Laboratory, Richland WA 99352 USA; Sushko, Maria L. [Pacific Northwest National Laboratory, Richland WA 99352 USA; Han, Kee Sung [Pacific Northwest National Laboratory, Richland WA 99352 USA; Shao, Yuyan [Pacific Northwest National Laboratory, Richland WA 99352 USA; Yan, Mengyu [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070 China; Liang, Xinmiao [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071 China; Mai, Liqiang [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070 China; Feng, Jiwen [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071 China; Cao, Yuliang [College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072 China; Ai, Xinping [College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072 China; Yang, Hanxi [College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072 China; Liu, Jun [Pacific Northwest National Laboratory, Richland WA 99352 USA

    2017-05-12

    Hard carbon is one of the most promising anode materials for sodium-ion batteries, but the low coulombic efficiency is still a key barrier. In this paper we synthesized a series of nanostructured hard carbon materials with controlled architectures. Using a combination of in-situ XRD mapping, ex-situ NMR, EPR, electrochemical techniques and simulations, an “adsorption-intercalation” (A-I) mechanism is established for Na ion storage. During the initial stages of Na insertion, Na ions adsorb on the defect sites of hard carbon with a wide adsorption energy distribution, producing a sloping voltage profile. In the second stage, Na ions intercalate into graphitic layers with suitable spacing to form NaCx compounds similar to the Li ion intercalation process in graphite, producing a flat low voltage plateau. The cation intercalation with a flat voltage plateau should be enhanced and the sloping region should be avoided. Guided by this knowledge, non-porous hard carbon material has been developed which has achieved high reversible capacity and coulombic efficiency to fulfill practical application.

  9. Comparison of the effects of photon versus carbon ion irradiation when combined with chemotherapy in vitro

    International Nuclear Information System (INIS)

    Schlaich, Fabian; Brons, Stephan; Haberer, Thomas; Debus, Jürgen; Combs, Stephanie E; Weber, Klaus-Josef

    2013-01-01

    Characterization of combination effects of chemotherapy drugs with carbon ions in comparison to photons in vitro. The human colon adenocarcinoma cell line WiDr was tested for combinations with camptothecin, cisplatin, gemcitabine and paclitaxel. In addition three other human tumour cell lines (A549: lung, LN-229: glioblastoma, PANC-1: pancreas) were tested for the combination with camptothecin. Cells were irradiated with photon doses of 2, 4, 6 and 8 Gy or carbon ion doses of 0.5, 1, 2 and 3 Gy. Cell survival was assessed using the clonogenic growth assay. Treatment dependent changes in cell cycle distribution (up to 12 hours post-treatment) were measured by FACS analysis after propidium-iodide staining. Apoptosis was monitored for up to 36 hours post-treatment by Nicoletti-assay (with qualitative verification using DAPI staining). All cell lines exhibited the well-known increase of killing efficacy per unit dose of carbon ion exposure, with relative biological efficiencies at 10% survival (RBE 10 ) ranging from 2.3 to 3.7 for the different cell lines. In combination with chemotherapy additive toxicity was the prevailing effect. Only in combination with gemcitabine or cisplatin (WiDr) or camptothecin (all cell lines) the photon sensitivity was slightly enhanced, whereas purely independent toxicities were found with the carbon ion irradiation, in all cases. Radiation-induced cell cycle changes displayed the generally observed dose-dependent G2-arrest with little effect on S-phase fraction for all cell lines for photons and for carbon ions. Only paclitaxel showed a significant induction of apoptosis in WiDr cell line but independent of the used radiation quality. Combined effects of different chemotherapeutics with photons or with carbon ions do neither display qualitative nor substantial quantitative differences. Small radiosensitizing effects, when observed with photons are decreased with carbon ions. The data support the idea that a radiochemotherapy with common

  10. Ion irradiation-induced, localized sp2 to sp3 hybridized carbon transformation in walls of multiwalled carbon nanotubes

    Science.gov (United States)

    Kumari, Reetu; Singh, Fouran; Yadav, Brajesh S.; Kotnala, Ravinder K.; Peta, Koteswara Rao; Tyagi, Pawan K.; Kumar, Sanjeev; Puri, Nitin K.

    2017-12-01

    In this report, ion irradiation-induced localized sp2 to sp3 hybridized carbon transformation in multiwalled carbon nanotubes (MWCNTs) was observed after irradiating MWCNTs with high-energy Au+8 ions (100 MeV). The used MWCNTs were grown using cobaltocene and benzene as catalyst and carbon source, respectively by the thermal CVD technique and consist of both unfilled and Co-filled tubes. Prior to irradiation, the MWCNT sample was characterized using scanning electron microscope and micro-Raman and photoluminescence spectrometers. The effect of ion fluence on MWCNT walls and transformation of sp2 to sp3 sites was analyzed by Raman spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. We found that as the fluence increased, the localized transformation from sp2 to sp3 sites occurred in the walls of MWCNTs, which was evident by the emergence of peak at approximately 1543 cm-1 associated with the G peak in tetrahedral amorphous carbon (ta-C) and the vanishing of 2D band (2700 cm-1). Furthermore, we observed broadening in D and G, with slight shift in their positions and consistent decrease in 2D band intensity, as fluence increased.

  11. Operation of KeiGM for the carbon ion therapy facility at Gunma University

    International Nuclear Information System (INIS)

    Muramatsu, M.; Kitagawa, A.; Hojo, S.; Miyazaki, H.; Ueno, T.; Sawada, K.; Tsuchiyama, M.; Ueda, S.; Kijima, Y.; Torikai, K.; Yamada, S.

    2012-01-01

    Carbon-ion radiotherapy is being carried out at Gunma University Heavy Ion Medical Centre (GHMC) since March 2010. A compact electron cyclotron resonance ion source (ECRIS) for GHMC, so-called KeiGM, supplies carbon 4+ ions for treatment. The general structure of KeiGM was copied from a prototype compact source, so-called Kei2. Based on experimental studies for production of carbon 4+ ions with a 10 GHz ECR source at the Heavy Ion Medical Accelerator in Chiba (HIMAC), so-called NIRS-ECR, the field distribution of the mirror magnet for Kei2 and KeiGM was designed. A microwave source with the traveling-wave-tube (TWT) was adopted for KeiGM, with a frequency range and maximum power of 9.75 - 10.25 GHz and 750 W, respectively. The KeiGM was installed in the GHMC facility in December 2008. The paper is followed by the associated poster. (authors)

  12. Effects of Carbon Structure and Surface Oxygen on the Carbon's Performance as the Anode in Lithium-Ion Battery Determined

    Science.gov (United States)

    Hung, Ching-Cheh

    2000-01-01

    Four carbon materials (C1, C2, C3, and C4) were tested electrochemically at the NASA Glenn Research Center at Lewis Field to determine their performance in lithium-ion batteries. They were formed as shown in the figure. This process caused very little carbon loss. Products C1 and C3 contained very little oxygen because of the final overnight heating at 540 C. Products C2 and C4, on the other hand, contained small amounts of basic oxide. The electrochemical test involved cycles of lithium intercalation and deintercalation using C/saturated LiI-50/50 (vol %) ethylene carbonate (EC) and dimethyl carbonate (DMC)/Li half cell. The cycling test, which is summarized in the table, resulted in three major conclusions. The capacity of the carbon with a basic oxide surface converges to a constant 1. value quickly (within 4 cycles), possibly because the oxide prevents solvent from entering the carbon structure and, therefore, prolongs the carbon s cycle life. Under certain conditions, the disordered carbon can store more lithium than its 2. precursor. These samples and their precursor can intercalate at 200 mA/g and deintercalate at 3. a rate of 2000 mA/g without significant capacity loss.

  13. Role of carbon impurities on the surface morphology evolution of tungsten under high dose helium ion irradiation

    International Nuclear Information System (INIS)

    Al-Ajlony, A.; Tripathi, J.K.; Hassanein, A.

    2015-01-01

    The effect of carbon impurities on the surface evolution (e.g., fuzz formation) of tungsten (W) surface during 300 eV He ions irradiation was studied. Several tungsten samples were irradiated by He ion beam with a various carbon ions percentage. The presence of minute carbon contamination within the He ion beam was found to be effective in preventing the fuzz formation. At higher carbon concentration, the W surface was found to be fully covered with a thick graphitic layer on the top of tungsten carbide (WC) layer that cover the sample surface. Lowering the ion beam carbon percentage was effective in a significant reduction in the thickness of the surface graphite layer. Under these conditions the W surface was also found to be immune for the fuzz formation. The effect of W fuzz prevention by the WC formation on the sample surface was more noticeable when the He ion beam had much lower carbon (C) ions content (0.01% C). In this case, the fuzz formation was prevented on the vast majority of the W sample surface, while W fuzz was found in limited and isolated areas. The W surface also shows good resistance to morphology evolution when bombarded by high flux of pure H ions at 900 °C. - Highlights: • Reporting formation of W nanostructure (fuzz) due to low energy He ion beam irradiation. • The effect of adding various percentage of carbon impurity to the He ion beam on the trend of W fuzz formation was studied. • Mitigation of W fuzz formation due to addition of small percentage of carbon to the He ion beam is reported. • The formation of long W nanowires due to He ion beam irradiation mixed with 0.01% carbon ions is reported.

  14. A Monte-Carlo code for the detailed simulation of electron and light-ion tracks in condensed matter

    International Nuclear Information System (INIS)

    Emfietzoglou, D.; Papamichael, G.; Karava, K.; Androulidakis, I.; Pathak, A.; Phillips, G. W.; Moscovitch, M.; Kostarelos, K.

    2006-01-01

    In an effort to understand the basic mechanism of the action of charged particles in solid radiation dosimeters, we extend our Monte-Carlo code (MC4) to condensed media (liquids/solids) and present new track-structure calculations for electrons and protons. Modeling the energy dissipation process is based on a model dielectric function, which accounts in a semi-empirical and self-consistent way for condensed-phase effects which are computationally intractable. Importantly, these effects mostly influence track-structure characteristics at the nano-meter scale, which is the focus of radiation action models. Since the event-by-event scheme for electron transport is impractical above several kilo-electron volts, a condensed-history random-walk scheme has been implemented to transport the energetic delta rays produced by energetic ions. Based on the above developments, new track-structure calculations are presented for two representative dosimetric materials, namely, liquid water and silicon. Results include radial dose distributions in cylindrical and spherical geometries, as well as, clustering distributions, which, among other things, are important in predicting irreparable damage in biological systems and prompt electric-fields in microelectronics. (authors)

  15. Oxidation processes on conducting carbon additives for lithium-ion batteries

    KAUST Repository

    La Mantia, Fabio

    2012-11-21

    The oxidation processes at the interface between different types of typical carbon additives for lithium-ion batteries and carbonates electrolyte above 5 V versus Li/Li+ were investigated. Depending on the nature and surface area of the carbon additive, the irreversible capacity during galvanostatic cycling between 2.75 and 5.25 V versus Li/Li+ could be as high as 700 mAh g-1 (of carbon). In the potential region below 5 V versus Li/Li+, high surface carbon additives also showed irreversible plateaus at about 4.1-4.2 and 4.6 V versus Li/Li+. These plateaus disappeared after thermal treatments at or above 150 °C in inert gas. The influence of the irreversible capacity of carbon additives on the overall performances of positive electrodes was discussed. © 2012 Springer Science+Business Media Dordrecht.

  16. Deciphering the Ethylene Carbonate-Propylene Carbonate Mystery in Li-Ion Batteries.

    Science.gov (United States)

    Xing, Lidan; Zheng, Xiongwen; Schroeder, Marshall; Alvarado, Judith; von Wald Cresce, Arthur; Xu, Kang; Li, Qianshu; Li, Weishan

    2018-02-20

    As one of the landmark technologies, Li-ion batteries (LIBs) have reshaped our life in the 21stcentury, but molecular-level understanding about the mechanism underneath this young chemistry is still insufficient. Despite their deceptively simple appearances with just three active components (cathode and anode separated by electrolyte), the actual processes in LIBs involve complexities at all length-scales, from Li + migration within electrode lattices or across crystalline boundaries and interfaces to the Li + accommodation and dislocation at potentials far away from the thermodynamic equilibria of electrolytes. Among all, the interphases situated between electrodes and electrolytes remain the most elusive component in LIBs. Interphases form because no electrolyte component (salt anion, solvent molecules) could remain thermodynamically stable at the extreme potentials where electrodes in modern LIBs operate, and their chemical ingredients come from the sacrificial decompositions of electrolyte components. The presence of an interphase on electrodes ensures reversibility of Li + intercalation chemistry in anode and cathode at extreme potentials and defines the cycle life, power and energy densities, and even safety of the eventual LIBs device. Despite such importance and numerous investigations dedicated in the past two decades, we still cannot explain why, nor predict whether, certain electrolyte solvents can form a protective interphase to support the reversible Li + intercalation chemistries while others destroy the electrode structure. The most representative example is the long-standing "EC-PC Disparity" and the two interphasial extremities induced therefrom: differing by only one methyl substituent, ethylene carbonate (EC) forms almost ideal interphases on the graphitic anode, thus becoming the indispensable solvent in all LIBs manufactured today, while propylene carbonate (PC) does not form any protective interphase, leading to catastrophic exfoliation of the

  17. Stability and kinetics of uranyl ion complexation by macrocycles in propylene carbonate

    International Nuclear Information System (INIS)

    Fux, P.

    1984-06-01

    A thermodynamic study of uranyl ion complexes formation with different macrocyclic ligands was realized in propylene carbonate as solvent using spectrophotometric and potentiometric techniques. Formation kinetics of two UO 2 complexes: a crown ether (18C6) and a coronand (22) was studied by spectrophotometry in propylene carbonate with addition of tetraethylammonium chlorate 0.1M at 25 0 C. Possible structures of complexes in solution are discussed [fr

  18. SU-F-T-144: Analytical Closed Form Approximation for Carbon Ion Bragg Curves in Water

    Energy Technology Data Exchange (ETDEWEB)

    Tuomanen, S; Moskvin, V; Farr, J [St. Jude Children’s Research Hospital, Memphis, TN (United States)

    2016-06-15

    Purpose: Semi-empirical modeling is a powerful computational method in radiation dosimetry. A set of approximations exist for proton ion depth dose distribution (DDD) in water. However, the modeling is more complicated for carbon ions due to fragmentation. This study addresses this by providing and evaluating a new methodology for DDD modeling of carbon ions in water. Methods: The FLUKA, Monte Carlo (MC) general-purpose transport code was used for simulation of carbon DDDs for energies of 100–400 MeV in water as reference data model benchmarking. Based on Thomas Bortfeld’s closed form equation approximating proton Bragg Curves as a basis, we derived the critical constants for a beam of Carbon ions by applying models of radiation transport by Lee et. al. and Geiger to our simulated Carbon curves. We hypothesized that including a new exponential (κ) residual distance parameter to Bortfeld’s fluence reduction relation would improve DDD modeling for carbon ions. We are introducing an additional term to be added to Bortfeld’s equation to describe fragmentation tail. This term accounts for the pre-peak dose from nuclear fragments (NF). In the post peak region, the NF transport will be treated as new beams utilizing the Glauber model for interaction cross sections and the Abrasion- Ablation fragmentation model. Results: The carbon beam specific constants in the developed model were determined to be : p= 1.75, β=0.008 cm-1, γ=0.6, α=0.0007 cm MeV, σmono=0.08, and the new exponential parameter κ=0.55. This produced a close match for the plateau part of the curve (max deviation 6.37%). Conclusion: The derived semi-empirical model provides an accurate approximation of the MC simulated clinical carbon DDDs. This is the first direct semi-empirical simulation for the dosimetry of therapeutic carbon ions. The accurate modeling of the NF tail in the carbon DDD will provide key insight into distal edge dose deposition formation.

  19. Characteristics of shunting arc discharge for carbon ion source

    International Nuclear Information System (INIS)

    Takaki, K.; Mukaigawa, S.; Fujiwara, T.; Kumagai, M.; Yukimura, K.

    2003-01-01

    The criteria of initial resistance of carbon rod for shunting arc ignition are described in this article. The five different resistances were used. The rods are 40 mm in length and 2 mm in diameter. The carbon rod was set in the vacuum and was initially heated up with a pulsed current supplied by a charged capacitor with a capacitance of 20 μF, followed by a self-ignition. The heating energy is almost independent of the charging voltage of the capacitor. The heating energy increases with decreasing the rod resistance, whereas the energy deposited in the plasma and the utilizing efficiency of the charged energy in the capacitor decreases

  20. Quantum ion-acoustic oscillations in single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Khan, S.A. [Kyoto Univ., Katsura (Japan). Graduate School of Engineering; Quaid-i-Azam Univ., Islamabad (Pakistan). National Centre for Physics; Iqbal, Z. [University of Management and Technology, Sialkot (Pakistan); Wazir, Z. [Riphah International Univ., Islamabad (Pakistan). Dept. of Basic Sciences; Rehman, Aman ur [Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad (Pakistan)

    2016-08-01

    Quantum ion-acoustic oscillations in single-walled carbon nanotubes are studied by employing a quantum hydrodynamics model. The dispersion equation is obtained by Fourier transformation, which exhibits the existence of quantum ion-acoustic wave affected by change of density balance due to presence of positive or negative heavy species as stationary ion clusters and wave potential at equilibrium. The numerical results are presented, and the role of quantum degeneracy, nanotube geometry, electron exchange-correlation effects, and concentration and polarity of heavy species on wave dispersion is pointed out for typical systems of interest.

  1. Quantum Ion-Acoustic Oscillations in Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Khan, S. A.; Iqbal, Z.; Wazir, Z.; Aman-ur-Rehman

    2016-05-01

    Quantum ion-acoustic oscillations in single-walled carbon nanotubes are studied by employing a quantum hydrodynamics model. The dispersion equation is obtained by Fourier transformation, which exhibits the existence of quantum ion-acoustic wave affected by change of density balance due to presence of positive or negative heavy species as stationary ion clusters and wave potential at equilibrium. The numerical results are presented, and the role of quantum degeneracy, nanotube geometry, electron exchange-correlation effects, and concentration and polarity of heavy species on wave dispersion is pointed out for typical systems of interest.

  2. Water purification from metal ions using carbon nanoparticle-conjugated polymer nanocomposites.

    Science.gov (United States)

    Khaydarov, Rashid A; Khaydarov, Renat R; Gapurova, Olga

    2010-03-01

    The paper deals with a novel method of obtaining nanocarbon-conjugated polymer nanocomposites (NCPC) using nanocarbon colloids (NCC) and polyethylenimine (PEI) for water purification from metal ions. Size of NCC, process of NCPC synthesis, its chemical characteristics, ratio of NCC and PEI in NCPC, speed of coagulation of NCPC, mechanism of interaction of metal ions with NCPC, ability of removing metal ions from water by NCPC against pH have been studied. NCPC has a bonding capacity of 4.0-5.7mmol/g at pH 6 for most of the divalent metal ions. Percent of sorption of Zn(2+), Cd(2+), Cu(2+), Hg(2+), Ni(2+), Cr(6+) ions is higher than 99%. Lifetime of NCPC before coagulation in the treated water is 1s-1000min and depends on the ratio of polymeric molecules and carbon nanoparticle concentrations. Results of laboratory tests of the method are described. Copyright 2009 Elsevier Ltd. All rights reserved.

  3. Structure and polarization near the Li+ ion in ethylene and propylene carbonates

    Science.gov (United States)

    Pollard, Travis P.; Beck, Thomas L.

    2017-10-01

    Research on fundamental interactions in Li-ion batteries is accelerating due to the importance of developing batteries with enhanced energy and power densities while maintaining safety. Improving electrode materials and controlling the formation of the solid electrolyte interphase during the first battery charge have been the main focus areas for research. Ion-solvent interactions in the electrolyte are also of great importance in tuning solvation and transport properties, however. Here we present ab initio density functional theory simulations of a Li+ ion in ethylene and propylene carbonates. The aim is to obtain a detailed analysis of local solvation structure and solvent polarization near the ion and in the bulk. The results indicate the significance of molecular polarization for developing accurate solvation models. The simulations illustrate the substantial differences between ion solvation in water and in organic materials.

  4. Computational Evaluation of Amorphous Carbon Coating for Durable Silicon Anodes for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jeongwoon Hwang

    2015-10-01

    Full Text Available We investigate the structural, mechanical, and electronic properties of graphite-like amorphous carbon coating on bulky silicon to examine whether it can improve the durability of the silicon anodes of lithium-ion batteries using molecular dynamics simulations and ab-initio electronic structure calculations. Structural models of carbon coating are constructed using molecular dynamics simulations of atomic carbon deposition with low incident energies (1–16 eV. As the incident energy decreases, the ratio of sp2 carbons increases, that of sp3 decreases, and the carbon films become more porous. The films prepared with very low incident energy contain lithium-ion conducting channels. Also, those films are electrically conductive to supplement the poor conductivity of silicon and can restore their structure after large deformation to accommodate the volume change during the operations. As a result of this study, we suggest that graphite-like porous carbon coating on silicon will extend the lifetime of the silicon anodes of lithium-ion batteries.

  5. Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries

    Science.gov (United States)

    Badi, Nacer; Erra, Abhinay Reddy; Hernandez, Francisco C. Robles; Okonkwo, Anderson O.; Hobosyan, Mkhitar; Martirosyan, Karen S.

    2014-07-01

    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low working potential. However, pure silicon electrodes have shown poor mechanical integrity due to the dramatic expansion of the material during battery operation. This results in high irreversible capacity and short cycle life. We report on the synthesis and use of carbon and hybrid carbon-silicon nanostructures made by a simplified thermo-mechanical milling process to produce low-cost high-energy lithium ion battery anodes. Our work is based on an abundant, cost-effective, and easy-to-launch source of carbon soot having amorphous nature in combination with scrap silicon with crystalline nature. The carbon soot is transformed in situ into graphene and graphitic carbon during mechanical milling leading to superior elastic properties. Micro-Raman mapping shows a well-dispersed microstructure for both carbon and silicon. The fabricated composites are used for battery anodes, and the results are compared with commercial anodes from MTI Corporation. The anodes are integrated in batteries and tested; the results are compared to those seen in commercial batteries. For quick laboratory assessment, all electrochemical cells were fabricated under available environment conditions and they were tested at room temperature. Initial electrochemical analysis results on specific capacity, efficiency, and cyclability in comparison to currently available AC counterpart are promising to advance cost-effective commercial lithium ion battery technology. The electrochemical performance observed for

  6. Experimental control of the beam properties of laser-accelerated protons and carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Amin, Munib

    2008-12-15

    The laser generation of energetic high quality beams of protons and heavier ions has opened up the door to a plethora of applications. These beams are usually generated by the interaction of a short pulse high power laser with a thin metal foil target. They could already be applied to probe transient phenomena in plasmas and to produce warm dense matter by isochoric heating. Other applications such as the production of radioisotopes and tumour radiotherapy need further research to be put into practice. To meet the requirements of each application, the properties of the laser-accelerated particle beams have to be controlled precisely. In this thesis, experimental means to control the beam properties of laser-accelerated protons and carbon ions are investigated. The production and control of proton and carbon ion beams is studied using advanced ion source designs: Experiments concerning mass-limited (i.e. small and isolated) targets are conducted. These targets have the potential to increase both the number and the energy of laser-accelerated protons. Therefore, the influence of the size of a plane foil target on proton beam properties is measured. Furthermore, carbon ion sources are investigated. Carbon ions are of particular interest in the production of warm dense matter and in cancer radiotherapy. The possibility to focus carbon ion beams is investigated and a simple method for the production of quasi-monoenergetic carbon ion beams is presented. This thesis also provides an insight into the physical processes connected to the production and the control of laser-accelerated ions. For this purpose, laser-accelerated protons are employed to probe plasma phenomena on laser-irradiated targets. Electric fields evolving on the surface of laser-irradiated metal foils and hollow metal foil cylinders are investigated. Since these fields can be used to displace, collimate or focus proton beams, understanding their temporal and spatial evolution is crucial for the design of

  7. Experimental control of the beam properties of laser-accelerated protons and carbon ions

    International Nuclear Information System (INIS)

    Amin, Munib

    2008-12-01

    The laser generation of energetic high quality beams of protons and heavier ions has opened up the door to a plethora of applications. These beams are usually generated by the interaction of a short pulse high power laser with a thin metal foil target. They could already be applied to probe transient phenomena in plasmas and to produce warm dense matter by isochoric heating. Other applications such as the production of radioisotopes and tumour radiotherapy need further research to be put into practice. To meet the requirements of each application, the properties of the laser-accelerated particle beams have to be controlled precisely. In this thesis, experimental means to control the beam properties of laser-accelerated protons and carbon ions are investigated. The production and control of proton and carbon ion beams is studied using advanced ion source designs: Experiments concerning mass-limited (i.e. small and isolated) targets are conducted. These targets have the potential to increase both the number and the energy of laser-accelerated protons. Therefore, the influence of the size of a plane foil target on proton beam properties is measured. Furthermore, carbon ion sources are investigated. Carbon ions are of particular interest in the production of warm dense matter and in cancer radiotherapy. The possibility to focus carbon ion beams is investigated and a simple method for the production of quasi-monoenergetic carbon ion beams is presented. This thesis also provides an insight into the physical processes connected to the production and the control of laser-accelerated ions. For this purpose, laser-accelerated protons are employed to probe plasma phenomena on laser-irradiated targets. Electric fields evolving on the surface of laser-irradiated metal foils and hollow metal foil cylinders are investigated. Since these fields can be used to displace, collimate or focus proton beams, understanding their temporal and spatial evolution is crucial for the design of

  8. Ion dynamics in porous carbon electrodes in supercapacitors using in situ infrared spectroelectrochemistry.

    Science.gov (United States)

    Richey, Francis W; Dyatkin, Boris; Gogotsi, Yury; Elabd, Yossef A

    2013-08-28

    Electrochemical double layer capacitors (EDLCs), or supercapacitors, rely on electrosorption of ions by porous carbon electrodes and offer a higher power and a longer cyclic lifetime compared to batteries. Ionic liquid (IL) electrolytes can broaden the operating voltage window and increase the energy density of EDLCs. Herein, we present direct measurements of the ion dynamics of 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide in an operating EDLC with electrodes composed of porous nanosized carbide-derived carbons (CDCs) and nonporous onion-like carbons (OLCs) with the use of in situ infrared spectroelectrochemistry. For CDC electrodes, IL ions (both cations and anions) were directly observed entering and exiting CDC nanopores during charging and discharging of the EDLC. Conversely, for OLC electrodes, IL ions were observed in close proximity to the OLC surface without any change in the bulk electrolyte concentration during charging and discharging of the EDLC. This provides experimental evidence that charge is stored on the surface of OLCs in OLC EDLCs without long-range ion transport through the bulk electrode. In addition, for CDC EDLCs with mixed electrolytes of IL and propylene carbonate (PC), the IL ions were observed entering and exiting CDC nanopores, while PC entrance into the nanopores was IL concentration dependent. This work provides direct experimental confirmation of EDLC charging mechanisms that previously were restricted to computational simulations and theories. The experimental measurements presented here also provide deep insights into the molecular level transport of IL ions in EDLC electrodes that will impact the design of the electrode materials' structure for electrical energy storage.

  9. Technical Note: Experimental carbon ion range verification in inhomogeneous phantoms using prompt gammas

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, M.; Dauvergne, D.; Dedes, G.; Krimmer, J.; Ray, C.; Testa, E., E-mail: e.testa@ipnl.in2p3.fr; Testa, M. [IPNL, Université de Lyon, Lyon F-69003 |(France); Université Lyon 1, Villeurbanne F-69622 (France); CNRS/IN2P3, UMR 5822, Villeurbanne F-69622 (France); De Rydt, M. [IPNL, Université de Lyon, Lyon F-69003 (France); Université Lyon 1, Villeurbanne F-69622 (France); CNRS/IN2P3, UMR 5822, Villeurbanne F-69622 (France); Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200D, Leuven B-3001 (Belgium); Freud, N.; Létang, J. M. [CREATIS, Université de Lyon, Lyon F-69003 (France); Université Lyon 1, Villeurbanne F-69622 (France); CNRS UMR 5220, INSERM U1044, INSA-Lyon, Centre Léon Bérard, 69008 Lyon (France)

    2015-05-15

    Purpose: The purpose of this study was to experimentally assess the possibility to monitor carbon ion range variations—due to tumor shift and/or elongation or shrinking—using prompt-gamma (PG) emission with inhomogeneous phantoms. Such a study is related to the development of PG monitoring techniques to be used in a carbon ion therapy context. Methods: A 95 MeV/u carbon ion beam was used to irradiate phantoms with a variable density along the ion path to mimic the presence of bone and lung in homogeneous humanlike tissue. PG profiles were obtained after a longitudinal scan of the phantoms. A setup comprising a narrow single-slit collimator and two detectors placed at 90° with respect to the beam axis was used. The time of flight technique was applied to allow the selection between PG and background events. Results: Using the positions at 50% entrance and 50% falloff of the PG profiles, a quantity called prompt-gamma profile length (PGPL) is defined. It is possible to observe shifts in the PGPL when there are absolute ion range shifts as small as 1–2 mm. Quantitatively, for an ion range shift of −1.33 ± 0.46 mm (insertion of a Teflon slab), a PGPL difference of −1.93 ± 0.58 mm and −1.84 ± 1.27 mm is obtained using a BaF{sub 2} and a NaI(Tl) detector, respectively. In turn, when an ion range shift of 4.59 ± 0.42 mm (insertion of a lung-equivalent material slab) is considered, the difference is of 4.10 ± 0.54 and 4.39 ± 0.80 mm for the same detectors. Conclusions: Herein, experimental evidence of the usefulness of employing PG to monitor carbon ion range using inhomogeneous phantoms is presented. Considering the homogeneous phantom as reference, the results show that the information provided by the PG emission allows for detecting ion range shifts as small as 1–2 mm. When considering the expected PG emission from an energy slice in a carbon ion therapy scenario, the experimental setup would allow to retrieve the same PGPL as the high statistics of

  10. A GEM-TPC in twin configuration for the Super-FRS tracking of heavy ions at FAIR

    Science.gov (United States)

    García, F.; Grahn, T.; Hoffmann, J.; Jokinen, A.; Kaya, C.; Kunkel, J.; Rinta-Antila, S.; Risch, H.; Rusanov, I.; Schmidt, C. J.; Simon, H.; Simons, C.; Turpeinen, R.; Voss, B.; Äystö, J.; Winkler, M.

    2018-03-01

    The GEM-TPC described herein will be part of the standard beam-diagnostics equipment of the Super-FRS. This chamber will provide tracking information for particle identification at rates up to 1 MHz on an event-by-event basis. The key requirements of operation for these chambers are: close to 100% tracking efficiency under conditions of high counting rate, spatial resolution below 1 mm and a superb large dynamic range covering projectiles from Z = 1 up to Z = 92. The current prototype consists of two GEM-TPCs inside a single vessel, which are operating independently and have electrical drift fields in opposite directions. The twin configuration is done by flipping one of the GEM-TPCs on the middle plane with respect to the second one. In order to put this development in context, the evolution of previous prototypes will be described and its performances discussed. Finally, this chamber was tested at the University of Jyväskylä accelerator with proton projectiles and at GSI with Uranium, Xenon, fragments and Carbon beams. The results obtained have shown a position resolution between 120 to 300 μm at moderate counting rate under conditions of full tracking efficiency.

  11. A Monte Carlo study for the calculation of the average linear energy transfer (LET) distributions for a clinical proton beam line and a radiobiological carbon ion beam line.

    Science.gov (United States)

    Romano, F; Cirrone, G A P; Cuttone, G; Rosa, F Di; Mazzaglia, S E; Petrovic, I; Fira, A Ristic; Varisano, A

    2014-06-21

    Fluence, depth absorbed dose and linear energy transfer (LET) distributions of proton and carbon ion beams have been investigated using the Monte Carlo code Geant4 (GEometry ANd Tracking). An open source application was developed with the aim to simulate two typical transport beam lines, one used for ocular therapy and cell irradiations with protons and the other for cell irradiations with carbon ions. This tool allows evaluation of the primary and total dose averaged LET and predict their spatial distribution in voxelized or sliced geometries. In order to reproduce the LET distributions in a realistic way, and also the secondary particles' contributions due to nuclear interactions were considered in the computations. Pristine and spread-out Bragg peaks were taken into account both for proton and carbon ion beams, with the maximum energy of 62 MeV/n. Depth dose distributions were compared with experimental data, showing good agreement. Primary and total LET distributions were analysed in order to study the influence of contributions of secondary particles in regions at different depths. A non-negligible influence of high-LET components was found in the entrance channel for proton beams, determining the total dose averaged LET by the factor 3 higher than the primary one. A completely different situation was obtained for carbon ions. In this case, secondary particles mainly contributed in the tail that is after the peak. The results showed how the weight of light and heavy secondary ions can considerably influence the computation of LET depth distributions. This has an important role in the interpretation of results coming from radiobiological experiments and, therefore, in hadron treatment planning procedures.

  12. Gamma and Ion-Beam Irradiation of DNA: Free Radical Mechanisms, Electron Effects, and Radiation Chemical Track Structure

    Science.gov (United States)

    Sevilla, Michael D.; Becker, David; Kumar, Anil; Adhikary, Amitava

    2016-01-01

    The focus of our laboratory’s investigation is to study the direct-type DNA damage mechanisms resulting from γ-ray and ion-beam radiation-induced free radical processes in DNA which lead to molecular damage important to cellular survival. This work compares the results of low LET (γ−) and high LET (ion-beam) radiation to develop a chemical track structure model for ion-beam radiation damage to DNA. Recent studies on protonation states of cytosine cation radicals in the N1-substituted cytosine derivatives in their ground state and 5-methylcytosine cation radicals in ground as well as in excited state are described. Our results exhibit a radical signature of excitations in 5-methylcytosine cation radical. Moreover, our recent theoretical studies elucidate the role of electron-induced reactions (low energy electrons (LEE), presolvated electrons (epre−), and aqueous (or, solvated) electrons (eaq−)). Finally DFT calculations of the ionization potentials of various sugar radicals show the relative reactivity of these species. PMID:27695205

  13. Recording of heavy ion tracks in silicates. Application to the determination of the abundance of ultra-heavy elements in old solar cosmic radiation

    International Nuclear Information System (INIS)

    Duraud, J.-P.

    1978-12-01

    The aim of this thesis is to determine the abundance A(Z) and energy spectrum of the elements of atomic number Z present in cosmic radiation, by means of fossil traces recorded in moon and meteorite minerals. The difficulties due amongst other things to natural annealing are examined in detail in part one, of this paper, the outcome being a thorough study of the processes responsible for the formation, chemical attack and annealing of heavy ion tracks. Part two describes an original approach used here and consisting of a combined analysis as a function of annealing for a given track, of the microscopic structure of the latent track and its attack rate. Part three uses the new rules established beforehand to propose a new method of studying the UH ion (Z>30) to VH ion (20 [fr

  14. Selective capillary diffusion of equimolar H2/D2 gas mixtures through etched ion track membranes prepared from polyethylene terephthalate and polyimide

    International Nuclear Information System (INIS)

    Schmidt, K.; Angert, N.; Trautmann, C.

    1996-01-01

    The selective capillary diffusion of equimolar H 2 /D 2 gas mixtures through ion track membranes prepared from polyethylene terephthalate and polyimide was investigated at a temperature of 293 K, a primary pressure of 0.15 MPa and a secondary pressure of 10 -4 MPa. Different values of the separation factor Z(H 2 /D 2 ) between experiment and computer simulation exists in the case of polyethylene terephthalate ion track membranes because of multiple pores. Membranes for which multiple pores were reduced by varying the irradiation angle showed an increased separation factor. The separation factor is a function of the pore diameter. This is shown for polyimide ion track membranes with a pore size in the range of 0.17 and 0.5 μm. After grafting with styrene the separation factor increased, indicating grafting within the pores. (orig.)

  15. Carbonation of wollastonite(001) competing hydration: microscopic insights from ion spectroscopy and density functional theory.

    Science.gov (United States)

    Longo, Roberto C; Cho, Kyeongjae; Brüner, Philipp; Welle, Alexander; Gerdes, Andreas; Thissen, Peter

    2015-03-04

    In this paper, we report about the influence of the chemical potential of water on the carbonation reaction of wollastonite (CaSiO3) as a model surface of cement and concrete. Total energy calculations based on density functional theory combined with kinetic barrier predictions based on nudge elastic band method show that the exposure of the water-free wollastonite surface to CO2 results in a barrier-less carbonation. CO2 reacts with the surface oxygen and forms carbonate (CO3(2-)) complexes together with a major reconstruction of the surface. The reaction comes to a standstill after one carbonate monolayer has been formed. In case one water monolayer is covering the wollastonite surface, the carbonation is no more barrier-less, yet ending in a localized monolayer. Covered with multilayers of water, the thermodynamic ground state of the wollastonite completely changes due to a metal-proton exchange reaction (also called early stage hydration) and Ca(2+) ions are partially removed from solid phase into the H2O/wollastonite interface. Mobile Ca(2+) reacts again with CO2 and forms carbonate complexes, ending in a delocalized layer. By means of high-resolution time-of-flight secondary-ion mass spectrometry images, we confirm that hydration can lead to a partially delocalization of Ca(2+) ions on wollastonite surfaces. Finally, we evaluate the impact of our model surface results by the meaning of low-energy ion-scattering spectroscopy combined with careful discussion about the competing reactions of carbonation vs hydration.

  16. Construction of a Unique Two-Dimensional Hierarchical Carbon Architecture for Superior Lithium-Ion Storage.

    Science.gov (United States)

    Wang, Zhijie; Yu, Xiaoliang; He, Wenhui; Kaneti, Yusuf Valentino; Han, Da; Sun, Qi; He, Yan-Bing; Xiang, Bin

    2016-12-14

    Two-dimensional nanocarbons are intriguing functional materials for energy storage. However, the serious aggregation problems hinder their wider applications. To address this issue, we developed a unique two-dimensional hierarchical carbon architecture (2D-HCA) with ultrasmall graphene-like carbon nanosheets uniformly grown on hexagonal carbon nanoplates. The obtained 2D-HCA shows an interconnected porous structure and abundant heteroelement doping. When employed as anode for lithium ion batteries, it exhibits a high discharge capacity of 748 m Ah g -1 even after 400 cycles at 2 A g -1 .

  17. Ion microprobe analyses of carbon in Fe-Ni metal in iron meteorites and mesosiderites

    Science.gov (United States)

    Goldstein, Joseph I.; Huss, Gary R.; Scott, Edward R. D.

    2017-03-01

    Carbon concentrations in kamacite, taenite, and plessite (kamacite-taenite intergrowths) were measured in 18 iron meteorites and 2 mesosiderites using the Cameca ims 1280 ion microprobe at the University of Hawai'i with a 5-7 μm beam and a detection limit of metal phases and other carbon-bearing minerals (graphite, haxonite, cohenite) in various meteorite groups. Carbon concentrations range from ∼100 to ∼1000 ppm in taenite and plessite in groups IAB, IIICD, and IIIAB, which contain graphite and/or carbides, but only 2-6 ppm in groups IVA, IVB and the ungrouped iron, Tishomingo, which lack graphite and carbides. Carbon contents in kamacite range from ∼2 to ∼10 ppm in most studied meteorites, including IIAB, but higher abundances were found in kamacite from IAB Pitts subgroup meteorites Pitts and Woodbine (12-15 ppm). Our carbon abundances for kamacite are lower than most published ion probe data, indicating that earlier carbon measurements had contamination problems. Grains of taenite and fine-grained plessite in carbon-rich meteorites, which all have normal M-shaped nickel profiles due to slow cooling, have diverse carbon contents and zoning profiles. This is because taenite decomposed by diverse mechanisms over a range of temperatures, when nickel could only diffuse over sub-μm distances. Carbon diffusion through taenite to growing carbides was rapid at the upper end of this temperature range, but was very limited at the lower end of the temperature range. In mesosiderites, carbon increases from 12 ppm in tetrataenite to 40-115 ppm in cloudy taenite as nickel decreases from 50% to 35%. Low carbon levels in tetrataenite may reflect ordering of iron and nickel; higher carbon in cloudy taenite is attributed to metastable bcc phase, possibly martensite, with ∼300 ppm carbon intergrown with tetrataenite. Pearlitic plessite, which only forms in carbon-rich irons, contains much less carbon than martensitic plessite: 10-20 ppm and 300-500, respectively, in

  18. Effects of main traits of sweet sorghum irradiated by carbon ions

    International Nuclear Information System (INIS)

    Li Wenjian; He Jingyu; Liu Qingfang; Yu Lixia; Dong Xicun

    2009-01-01

    To investigate the influence of carbon ion irradiation on important agronomic characters of sweet sorghum, dry seeds of Sweet Sorghum BJ0601 and BJ0602 were irradiated by 100 MeV/u 12 C +6 ion beam to different doses at Heavy Ion Accelerator National Laboratory in Lanzhou (HIANLL). When matured, the main traits of sweet sorghum were measured. The correlation coefficient of five main agronomic characters, i.e. number of node, plant height, stalk diameter, sugar content and stem weight per plant, were analyzed using the SPSS 13.0 software. The results indicated that the obvious influence of sweet sorghum irradiated by carbon ion beam was observed. In addition, the correlation of main traits was studied. This study may provide rudimental data to select novel variety of sweet sorghum suited for fuel ethanol production. In addition, the average of sugar content of early mutant BJ0601-1 is higher than BJ0601 in M2, and the sugar content of sweet sorghum may be improved by carbon ion beam irradiation. (authors)

  19. Removal of heavy metal ions from wastewaters using dendrimer-functionalized multi-walled carbon nanotubes.

    Science.gov (United States)

    Iannazzo, Daniela; Pistone, Alessandro; Ziccarelli, Ida; Espro, Claudia; Galvagno, Signorino; Giofré, Salvatore V; Romeo, Roberto; Cicero, Nicola; Bua, Giuseppe D; Lanza, Giuseppe; Legnani, Laura; Chiacchio, Maria A

    2017-06-01

    Dendrimer-functionalized multi-walled carbon nanotubes (MWCNT) for heavy metal ion removal from wastewaters were developed. Triazole dendrimers (TD) were built directly onto the carbon nanotube surface by successive click chemistry reactions affording the zero- and first-generation dendrimer-functionalized MWCNT (MWCNT-TD1 and MWCNT-TD2). The Moedritzer-Irani reaction carried out on the amino groups present on the MWCNT-TD2 sample gave the corresponding α-aminophosphonate nanosystem MWCNT-TD2P. Both MWCNT-TD2 and MWCNT-TD2P nanosystems have been characterized by physical, chemical, and morphological analyses. Their chelating abilities towards the toxic metal ions Pb 2+ , Hg 2+ , and Ni 2+ and the harmless Ca 2+ ion have been experimentally evaluated in the two different sets of experiments and at the salt concentrations of 1 mg/mL or 1 μg/mL by inductively coupled plasma mass spectrometry (ICP-MS). The results of these studies pointed out the interesting chelating behavior for the phosphonated nanosystem towards the Hg 2+ ion. The complexation mode of the best chelating system MWCNT-TD2P with mercury was investigated through density functional theory (DFT) calculations, suggesting a chelation mechanism involving the two oxygen atoms of the phosphate group. The synthesized dendrimers, supported on the multi-walled carbon nanotubes, have shown the potential to be used for the selective toxic metal ion removal and recovery.

  20. Rigid versus Flexible Ligands on Carbon Nanotubes for the Enhanced Sensitivity of Cobalt Ions

    Energy Technology Data Exchange (ETDEWEB)

    Gou, Pingping; Kraut, Nadine D.; Feigel, Ian Matthew; Star, Alexander

    2013-02-26

    Carbon nanotubes have shown great promise in the fabrication of ultra-compact and highly sensitive chemical and biological sensors. Additional chemical functionalization schemes can controllably improve selectivity of the carbon nanotube-based sensors; however the exact transduction mechanism is still under debate. In this article we detail the synthesis and selective response of single-walled carbon nanotubes (SWNTs) functionalized with polyazomethine (PAM) polymer towards the application of a specific trace metal ion detector. The response of the polymer system was compared to shape persistent macrocycle (MAC) comprised of identical ion coordination ligands. While ion detection with rigid MAC/SWNT chemiresistor was comparable to bare SWNT, flexible PAM offers significant SWNT signal amplification, allowing for picomolar detection of Co{sup 2+} ions with both selectivity and a fast response. We hypothesized that rearrangement of the flexible PAM on the SWNT network is a sensing mechanism which allows for ultrasensitive detection of metal ions. The electron transfer and polymer rearrangement on the SWNT was studied by a combination of optical spectroscopy and electrical measurements - ultimately allowing for a better understanding of fundamental mechanisms that prompt device response.

  1. Radioprotective effects of melatonin on carbon-ion and X ray irradiation in mice

    International Nuclear Information System (INIS)

    Saito, Masayoshi; Kawata, Tetsuya; Liu, C.; Sakurai, Akiko; Ito, Hisao; Ando, Koichi

    2004-01-01

    The radioprotective ability of melatonin was investigated in C3H mice irradiated to a whole-body X-ray (150 Kv, 20 mA) and carbon-ion (290 MeV/u). Mice exposed to X-ray, 13 KeV/μm and 50 KeV/μm carbon-ion dose of 7.0-7.5 Gy, 6.5-7.25 Gy and 6.0-6.5 Gy, respectively. One hour before the irradiation, mice were given an intraperitoneal injection of 0.2 ml of either solvent (soybean oil) or melatonin (250 mg/kg, uniform suspension in soybean oil). Mice were observed for mortality over a period of 30 days following irradiation. Results obtained the first year are as follows. The toxicity of melatonin (at a dose 250 mg/kg) intraperitoneal administered to mice could not be observed. A pretreatment of melatonin is effective in protecting mice from lethal damage of low-linear energy transfer (LET) irradiation (X-ray and 13 KeV/μm carbon-ion). In the high-LET irradiated mice with 50 KeV/μm carbon-ion, melatonin exhibited a slight increase in their survival. (author)

  2. Nanofluidic carbon-dioxide sensor using nanoscale hydronium-dominated ion transport theory

    DEFF Research Database (Denmark)

    Crumrine, A.M.; Shah, D.; Andersen, Mathias Bækbo

    2011-01-01

    We demonstrate a nanofluidic-based carbon dioxide sensor through corroboration with our nanochannel hydroniumdominated ion transport model. We verify the predictive power of our model by comparing calculated and measured conductances of solutions with added HCl in both bulk and in nanochannel...

  3. Histological study of choroidal malignant melanoma treated by carbon ion radiotherapy

    International Nuclear Information System (INIS)

    Tsuji, Masatoshi; Kimura, Katsuaki; Goto, Masamichi; Sakamoto, Taiji; Tsuji, Hiroshi; Yoshikawa, Hiroshi

    2007-01-01

    The purpose of this study was to report, we believe for the first time, a histological study of choroidal malignant melanoma treated by carbon ion beam radiotherapy. A 75-year-old Japanese man was diagnosed as having a choroidal melanoma after undergoing magnetic resonance imaging (MRI). Positron emission tomography (PET) revealed a hot spot in the same location as the intraocular mass seen in MRI. Carbon ion radiotherapy was performed with a total dose of 77 Gy, and the hot spot seen by PET disappeared completely. At 15 months after carbon ion therapy, the eye had to be enucleated because of uncontrollable ocular hypertension. It was examined histologically in serial sections. A large tumor mass (15 x 12 mm) with high pigmentation was found in the vitreous space. Almost all tumor cells showed necrosis in every section. A small number of intact tumor cells were present at the periphery. The overlying retina did not show any necrosis, but showed mild to moderate gliosis. No intraretinal hemorrhage, lipid deposit, or protein exudate was apparent. Almost all tumor cells showed necrosis after radiotherapy with a carbon ion beam. However, the effect on the adjacent tissues was determined as minimal in histological analysis. (author)

  4. Three-Dimensional Carbon Nanostructures for Advanced Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Chiwon Kang

    2016-10-01

    Full Text Available Carbon nanostructural materials have gained the spotlight as promising anode materials for energy storage; they exhibit unique physico-chemical properties such as large surface area, short Li+ ion diffusion length, and high electrical conductivity, in addition to their long-term stability. However, carbon-nanostructured materials have issues with low areal and volumetric densities for the practical applications in electric vehicles, portable electronics, and power grid systems, which demand higher energy and power densities. One approach to overcoming these issues is to design and apply a three-dimensional (3D electrode accommodating a larger loading amount of active anode materials while facilitating Li+ ion diffusion. Furthermore, 3D nanocarbon frameworks can impart a conducting pathway and structural buffer to high-capacity non-carbon nanomaterials, which results in enhanced Li+ ion storage capacity. In this paper, we review our recent progress on the design and fabrication of 3D carbon nanostructures, their performance in Li-ion batteries (LIBs, and their implementation into large-scale, lightweight, and flexible LIBs.

  5. An ion-optical design study of a carbon-ion rotating gantry with a superconducting final bending magnet

    International Nuclear Information System (INIS)

    Bokor, J.; Pavlovič, M.

    2016-01-01

    Ion-optical designs of an isocentric ion gantry with a compact curved superconducting final bending magnet are presented. The gantry is designed for transporting carbon-therapy beams with nominal kinetic energy of 400 MeV/u, which corresponds to the penetration range of C 6+ beam in water of about 28 cm. In contrast to other existing designs, we present a “hybrid” beam transport system containing a single superconducting element – the last bending magnet. All other elements are based on conventional warm technology. Ion-optical properties of such a hybrid system are investigated in case of transporting non-symmetric (i.e. different emittance patterns in the horizontal and vertical plane) beams. Different conditions for transporting the non-symmetric beams are analyzed aiming at finding the optimal, i.e. the most compact, gantry version. The final gantry layout is presented including a 2D parallel scanning. The ion-optical and scanning properties of the final gantry design are described, discussed and illustrated by computer simulations performed by WinAGILE.

  6. A novel track imaging system as a range counter

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z. [National Institute of Radiological Sciences (Japan); Matsufuji, N. [National Institute of Radiological Sciences (Japan); Tokyo Institute of Technology (Japan); Kanayama, S. [Chiba University (Japan); Ishida, A. [National Institute of Radiological Sciences (Japan); Tokyo Institute of Technology (Japan); Kohno, T. [Tokyo Institute of Technology (Japan); Koba, Y.; Sekiguchi, M.; Kitagawa, A.; Murakami, T. [National Institute of Radiological Sciences (Japan)

    2016-05-01

    An image-intensified, camera-based track imaging system has been developed to measure the tracks of ions in a scintillator block. To study the performance of the detector unit in the system, two types of scintillators, a dosimetrically tissue-equivalent plastic scintillator EJ-240 and a CsI(Tl) scintillator, were separately irradiated with carbon ion ({sup 12}C) beams of therapeutic energy from HIMAC at NIRS. The images of individual ion tracks in the scintillators were acquired by the newly developed track imaging system. The ranges reconstructed from the images are reported here. The range resolution of the measurements is 1.8 mm for 290 MeV/u carbon ions, which is considered a significant improvement on the energy resolution of the conventional ΔE/E method. The detector is compact and easy to handle, and it can fit inside treatment rooms for in-situ studies, as well as satisfy clinical quality assurance purposes.

  7. Adsorption of aqueous metal ions on cattle-manure-compost based activated carbons.

    Science.gov (United States)

    Zaini, Muhammad Abbas Ahmad; Okayama, Reiko; Machida, Motoi

    2009-10-30

    The objective of this study is to examine the suitability and performance of cattle-manure-compost (CMC) based activated carbons in removing heavy metal ions from aqueous solution. The influence of ZnCl(2) activation ratios and solution pH on the removal of Cu(II) and Pb(II) were studied. Pore texture, available surface functional groups, pH of point zero charge (pH(PZC)), thermogravimetric analysis and elemental compositions were obtained to characterize the activated carbons. Batch adsorption technique was used to determine the metal-binding ability of activated carbons. The equilibrium data were characterized using Langmuir, Freundlich and Redlich-Peterson models. It was found that the uptake of aqueous metal ions by activated carbons could be well described by Langmuir equation. It is suggested that the increase of surface area and mesopore ratio as a result of increasing activation ratios favored the removal of Cu(II), while activated carbon rich in acidic groups showed selective adsorption towards Pb(II). The preferable removal of Cu(II) over Pb(II) could be due to the rich nitrogen content as well as the higher mesoporous surface area in the CMC activated carbons. The impregnated CMC activated carbons also showed a better performance for Cu(II) removal at varying solution pH than Filtrasorb 400 (F400), while a similar performance was observed for Pb(II) removal.

  8. CoSn/carbon composite nanofibers for applications as anode in lithium-ion batteries

    International Nuclear Information System (INIS)

    Lu, Weili; Luo, Chenghao; Li, Yu; Feng, Yiyu; Feng, Wei; Zhao, Yunhui; Yuan, Xiaoyan

    2013-01-01

    CoSn/carbon composite nanofibers were prepared by electrospinning followed by heat treatment. Uniform morphologies and microstructures were observed by scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray diffraction. The results demonstrated that well-dispersed nanoparticles of CoSn intermetallic compound and Sn with diameter of about 30–50 nm embedded in carbon nanofibers were prepared after carbonization at 850 °C. Compared with pure carbon nanofibers without the nanoparticles, CoSn/carbon composite nanofibers showed a high reversible capacity and excellent cycling performance, resulting from the formation of CoSn intermetallic nanoparticles and buffering by the carbon nanofiber matrix. The nanofiber mats with good flexibility were utilized as anodes in lithium-ion batteries, and the CoSn/carbon composite nanofibers exhibited a good fibrous morphology after the discharge/charge processes. Results indicated that electrospinning could be a feasible method to prepare Co–Sn–C composite nanofibers as anodes in lithium-ion batteries

  9. Calibration of BAS-TR image plate response to high energy (3-300 MeV) carbon ions.

    Science.gov (United States)

    Doria, D; Kar, S; Ahmed, H; Alejo, A; Fernandez, J; Cerchez, M; Gray, R J; Hanton, F; MacLellan, D A; McKenna, P; Najmudin, Z; Neely, D; Romagnani, L; Ruiz, J A; Sarri, G; Scullion, C; Streeter, M; Swantusch, M; Willi, O; Zepf, M; Borghesi, M

    2015-12-01

    The paper presents the calibration of Fuji BAS-TR image plate (IP) response to high energy carbon ions of different charge states by employing an intense laser-driven ion source, which allowed access to carbon energies up to 270 MeV. The calibration method consists of employing a Thomson parabola spectrometer to separate and spectrally resolve different ion species, and a slotted CR-39 solid state detector overlayed onto an image plate for an absolute calibration of the IP signal. An empirical response function was obtained which can be reasonably extrapolated to higher ion energies. The experimental data also show that the IP response is independent of ion charge states.

  10. Efficient adsorption of Hg (II) ions in water by activated carbon modified with melamine

    Science.gov (United States)

    Qin, Hangdao; Meng, Jingling; Chen, Jing

    2018-04-01

    Removal of Hg (II) ions from industrial wastewater is important for the water treatment, and adsorption is an efficient treatment process. Activated carbon (AC) was modified with melamine, which introduced nitrogen-containing functional groups onto AC surface. Original AC and melamine modified activated carbon (ACM) were characterized by elemental analysis, N2 adsorption-desorption, determination of the pH of the point of zero charge (pHpzc) and X-ray photoelectron spectroscopy (XPS) and their performance in the adsorption of Hg(II) ions was investigated. Langmuir model fitted the experimental data of equilibrium isotherms well. ACM showed the higher Hg (II) ions adsorption capacity, increasing more than more than 1.8 times compared to the original one. Moreover, ACM showed a wider pH range for the maximum adsorption than the parent AC.

  11. Hydrophobization of track membrane surface by ion-plasma sputtering method

    Science.gov (United States)

    Kuklin, I. E.; Khlebnikov, N. A.; Barashev, N. R.; Serkov, K. V.; Polyakov, E. V.; Zdorovets, M. V.; Borgekov, D. B.; Zhidkov, I. S.; Cholakh, S. O.; Kozlovskiy, A. L.

    2017-09-01

    This article reviews the possibility of applying inorganic coatings of metal compounds on PTM by ion-plasma sputtering. The main aim of this research is to increase the contact angle of PTM surfaces and to impart the properties of a hydrophobic material to it. After the modification, the initial contact angle increased from 70° to 120°.

  12. Effects of model approximations for electron, hole, and photon transport in swift heavy ion tracks

    Czech Academy of Sciences Publication Activity Database

    Rymzhanov, R.A.; Medvedev, Nikita; Volkov, A.E.

    2016-01-01

    Roč. 388, Dec (2016), s. 41-52 ISSN 0168-583X R&D Projects: GA MŠk LG15013 Institutional support: RVO:68378271 Keywords : swift heavy ion * electronic stopping * TREKIS * Monte Carlo * electronic kinetics * photon transport Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.109, year: 2016

  13. Electronic excitation induced modifications in elongated iron nanoparticle encapsulated multiwalled carbon nanotubes under ion irradiation

    Science.gov (United States)

    Saikiran, V.; Bazylewski, P.; Sameera, I.; Bhatia, Ravi; Pathak, A. P.; Prasad, V.; Chang, G. S.

    2018-05-01

    Multi-wall carbon nanotubes (MWCNT) filled with Fe nanorods were shown to have contracted and deformed under heavy ion irradiation. In this study, 120 MeV Ag and 80 MeV Ni ion irradiation was performed to study the deformation and defects induced in iron filled MWCNT under heavy ion irradiation. The structural modifications induced due to electronic excitation by ion irradiation were investigated employing high-resolution transmission electron microscopy, micro-Raman scattering experiments, and synchrotron-based X-ray absorption and emission spectroscopy. We understand that the ion irradiation causes modifications in the Fe nanorods which result in compressions and expansions of the nanotubes, and in turn leads to the buckling of MWCNT. The G band of the Raman spectra shifts slightly towards higher wavenumber and the shoulder G‧ band enhances with the increase of ion irradiation fluence, where the buckling wavelength depends on the radius 'r' of the nanotubes as exp[(r)0.5]. The intensity ratio of the D to G Raman modes initially decreases at the lowest fluence, and then it increases with the increase in ion fluence. The electron diffraction pattern and the high resolution images clearly show the presence of ion induced defects on the walls of the tube and encapsulated iron nanorods.

  14. Differential Bystander Signaling Between Radioresistant Chondrosarcoma Cells and Fibroblasts After X-Ray, Proton, Iron Ion and Carbon Ion Exposures

    Energy Technology Data Exchange (ETDEWEB)

    Wakatsuki, Masaru, E-mail: wa@mbe.nifty.com [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts (United States); Magpayo, Nicole; Kawamura, Hidemasa; Held, Kathryn D. [Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts (United States)

    2012-09-01

    Purpose: Chondrosarcoma is well known as a radioresistant tumor, but the mechanisms underlying that resistance are still unclear. The bystander effect is well documented in the field of radiation biology. We investigated the bystander response induced by X-rays, protons, carbon ions, and iron ions in chondrosarcoma cells using a transwell insert co-culture system that precludes physical contact between targeted and bystander cells. Methods and Materials: Human chondrosarcoma cells were irradiated with 0.1-, 0.5-, 1-, and 2-Gy X-rays, protons, carbon ions or iron ions using a transwell insert co-culture system. Formation of micronuclei and p53 binding protein 1 staining in bystander and irradiated cells were analyzed and bystander signaling between mixed cultures of chondrosarcoma cells, and normal human skin fibroblasts was investigated. Results: In this study, we show that the fraction of cells with DNA damages in irradiated chondrosarcoma cells showed dose-dependent increases with all beams. However, the fraction of cells with DNA damages in all bystander chondrosarcoma cells did not show any change from the levels in control cells. In the bystander signaling between mixed cultures of chondrosarcoma cells and fibroblasts, the amount of micronucleus formation in all bystander chondrosarcoma cells co-cultured with irradiated fibroblasts were the same as the levels for control cells. However, all bystander fibroblasts co-cultured with irradiated chondrosarcoma cells showed significant increases in the fraction of micronucleated cells compared to the rate of control cells. Conclusions: We conclude that chondrosarcoma cells in the transwell insert co-culture system could release bystander stimulations but could not develop bystander responses.

  15. Adsorption Efficiency of Iron Modified Carbons for Removal of Pb(II Ions from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Salmani

    2016-06-01

    Full Text Available Abstract Introduction: The Lead causes severe damage to several systems of the body, especially to bony tissues. Until now, several low-cost biosorbents have been studied for removal of heavy metal ions from aqueous solutions. In the present study, carbonized pomegranate peels modified with Fe2+ and Fe3+ ions and then it was investigated for removal of Pb(II ions from aqueous solution. Materials and methods: the washed granola of pomegranate peel was separately socked with FeCl3 and FeCl2 solutions for 24 h. Then, the granules were carbonized at 400 ºC for 3 h in a programmable furnace in the atmosphere of nitrogen. The adsorption experiments were carried out for two types of iron-modified carbons by batch adsorption using one variable at a time procedures. Results: The optimum conditions were found as contact time 90 min, initial concentration 50 mg/l, and adsorbent dose, 1.00 g/100 ml solution. Maximum removal efficiency was calculated as 84% and 89% for Fe3+ and Fe2+ impregnated pomegranate peel carbons respectively. Conclusion: The iron treatment pomegranate peel carbons modified their surfaces for adsorption of heavy metals. The results showed that chemical modification of the low-cost adsorbents originating from agricultural waste has stood out for metal removal capabilities.

  16. Integrated carbon nanospheres arrays as anode materials for boosted sodium ion storage

    Directory of Open Access Journals (Sweden)

    Wangjia Tang

    2018-01-01

    Full Text Available Developing cost-effective advanced carbon anode is critical for innovation of sodium ion batteries. Herein, we develop a powerful combined method for rational synthesis of free-standing binder-free carbon nanospheres arrays via chemical bath plus hydrothermal process. Impressively, carbon spheres with diameters of 150–250 nm are randomly interconnected with each other forming highly porous arrays. Positive advantages including large porosity, high surface and strong mechanical stability are combined in the carbon nanospheres arrays. The obtained carbon nanospheres arrays are tested as anode material for sodium ion batteries (SIBs and deliver a high reversible capacity of 102 mAh g−1 and keep a capacity retention of 95% after 100 cycles at a current density of 0.25 A g−1 and good rate performance (65 mAh g−1 at a high current density of 2 A g−1. The good electrochemical performance is attributed to the stable porous nanosphere structure with fast ion/electron transfer characteristics.

  17. Kinetics of Adsorption of Ferrous Ion onto Acid Activated Carbon from Zea Mays Dust

    Directory of Open Access Journals (Sweden)

    P. K. Baskaran

    2011-01-01

    Full Text Available The batch removal of ferrous ion from aqueous solution using low cost adsorbents such as zea mays dust carbon(ZDC under different experimental conditions were investigated in this study. The process parameters studied include agitation time, initial metal ion concentration, carbon dose, pH and temperature. The adsorption followed first order reaction equation and the rate is mainly controlled by intraparticle diffusion. Freundlich and Langmuir isotherm models were applied to the equilibrium data. The adsorption capacity (Qm obtained from the Langmuir isotherm plot were found to 37.17, 38.31, 39.37 and 40.48 mg/g. The temperature variation study showed that the ferrous ions adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. Significant effect on adsorption was observed on varying the pH of the ferrous ion solutions. The Langmuir and Freundlich adsorption isotherms obtained positive ΔH0 value, pH dependent results and desorption of metal ions in mineral acid suggest that the adsorption of ferrous ion on ZDC involves physisorption mechanism.

  18. Dose and linear energy transfer distributions of primary and secondary particles in carbon ion radiation therapy: A Monte Carlo simulation study in water.

    Science.gov (United States)

    Johnson, Daniel; Chen, Yong; Ahmad, Salahuddin

    2015-01-01

    The factors influencing carbon ion therapy can be predicted from accurate knowledge about the production of secondary particles from the interaction of carbon ions in water/tissue-like materials, and subsequently the interaction of the secondary particles in the same materials. The secondary particles may have linear energy transfer (LET) values that potentially increase the relative biological effectiveness of the beam. Our primary objective in this study was to classify and quantify the secondary particles produced, their dose averaged LETs, and their dose contributions in the absorbing material. A 1 mm diameter carbon ion pencil beam with energies per nucleon of 155, 262, and 369 MeV was used in a geometry and tracking 4 Monte Carlo simulation to interact in a 27 L water phantom containing 3000 rectangular detector voxels. The dose-averaged LET and the dose contributions of primary and secondary particles were calculated from the simulation. The results of the simulations show that the secondary particles that contributed a major dose component had LETs 600 keV/µm contributed only <0.3% of the dose.

  19. Dose and linear energy transfer distributions of primary and secondary particles in carbon ion radiation therapy: A Monte Carlo simulation study in water

    Directory of Open Access Journals (Sweden)

    Daniel Johnson

    2015-01-01

    Full Text Available The factors influencing carbon ion therapy can be predicted from accurate knowledge about the production of secondary particles from the interaction of carbon ions in water/tissue-like materials, and subsequently the interaction of the secondary particles in the same materials. The secondary particles may have linear energy transfer (LET values that potentially increase the relative biological effectiveness of the beam. Our primary objective in this study was to classify and quantify the secondary particles produced, their dose averaged LETs, and their dose contributions in the absorbing material. A 1 mm diameter carbon ion pencil beam with energies per nucleon of 155, 262, and 369 MeV was used in a geometry and tracking 4 Monte Carlo simulation to interact in a 27 L water phantom containing 3000 rectangular detector voxels. The dose-averaged LET and the dose contributions of primary and secondary particles were calculated from the simulation. The results of the simulations show that the secondary particles that contributed a major dose component had LETs 600 keV/µm contributed only <0.3% of the dose.

  20. Self-organized formation of metal-carbon nanostructures by hyperthermal ion deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hannstein, I.K.

    2006-04-26

    The quasi-simultaneous deposition of mass-selected hyperthermal carbon and metal ions results in a variety of interesting film morphologies, depending on the metal used and the deposition conditions. The observed features are of the order of a few nanometres and are therefore interesting for future potential applications in the various fields of nanotechnology. The present study focuses on the structural analysis of amorphous carbon films containing either copper, silver, gold, or iron using amongst others Rutherford Backscattering Spectroscopy, High Resolution Transmission Electron Microscopy, and Energy Dispersive X-Ray Spectroscopy. The film morphologies found are as follows: copper-containing films consist of copper nanoclusters with sizes ranging from about 3 to 9 nm uniformly distributed throughout the amorphous carbon matrix. The cluster size hereby rises with the copper content of the films. The silver containing films decompose into a pure amorphous carbon film with silver agglomerates at the surface. Both, the gold- and the iron-containing films show a multilayer structure of metal-rich layers with higher cluster density separated by metal-depleted amorphous carbon layers. The layer distances are of the order of up to 15 nm in the case of gold-carbon films and 7 nm in the case of iron-carbon films. The formation of theses different structures cannot be treated in the context of conventional self-organization mechanisms basing upon thermal diffusion and equilibrium thermodynamics. Instead, an ion-induced atomic transport, sputtering effects, and the stability of small metal clusters were taken into account in order to model the structure formation processes. A similar multilayer morphology was recently also reported in the literature for metal-carbon films grown by magnetron sputtering techniques. In order to investigate, whether the mechanisms are the same as in the case of the ion beam deposited films described above, first experiments were conducted

  1. BEAM DYNAMICS STUDIES FOR A COMPACT CARBON ION LINAC FOR THERAPY

    Energy Technology Data Exchange (ETDEWEB)

    Plastun, A.; Mustapha, B.; Nassiri, A.; Ostroumov, P.

    2016-05-01

    Feasibility of an Advanced Compact Carbon Ion Linac (ACCIL) for hadron therapy is being studied at Argonne National Laboratory in collaboration with RadiaBeam Technologies. The 45-meter long linac is designed to deliver 109 carbon ions per second with variable energy from 45 MeV/u to 450 MeV/u. S-band structure provides the acceleration in this range. The carbon beam energy can be adjusted from pulse to pulse, making 3D tumor scanning straightforward and fast. Front end accelerating structures such as RFQ, DTL and coupled DTL are designed to operate at lower frequencies. The design of the linac was accompanied with extensive end-to-end beam dynamics studies which are presented in this paper.

  2. Hierarchical mesoporous/microporous carbon with graphitized frameworks for high-performance lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Yingying Lv

    2014-11-01

    Full Text Available A hierarchical meso-/micro-porous graphitized carbon with uniform mesopores and ordered micropores, graphitized frameworks, and extra-high surface area of ∼2200 m2/g, was successfully synthesized through a simple one-step chemical vapor deposition process. The commercial mesoporous zeolite Y was utilized as a meso-/ micro-porous template, and the small-molecule methane was employed as a carbon precursor. The as-prepared hierarchical meso-/micro-porous carbons have homogeneously distributed mesopores as a host for electrolyte, which facilitate Li+ ions transport to the large-area micropores, resulting a high reversible lithium ion storage of 1000 mA h/g and a high columbic efficiency of 65% at the first cycle.

  3. Influence of carbonate ions on the micellization behavior in triblock copolymer solution

    CERN Document Server

    Thiyagarajan, P

    2002-01-01

    SANS was used to investigate the micellization behavior of triblock copolymers (F68, F88 and F108) as functions of carbonate ion concentration and temperature. SANS data were fitted to determine the sizes of the core and corona, inter-micelle distance, association number and the volume fraction of the micelles. As the polymer molecular weight increases, the core radius and the radius of gyration (R sub g) of the corona and the inter-micelle distance increase. The carbonate ion concentration and polymer molecular weight have dramatic influence on the temperatures at which the micellization and spherical-to-cylindrical micelle transformation occur. The mechanism by which this phenomenon occurs in these solutions is through a gradual dehydration of polymers with increasing carbonate concentration and/or temperature. (orig.)

  4. A comparative study of track registration response of Makrofol-(KG, KL and N) polycarbonate to sup 4 sup 0 Ar ions

    CERN Document Server

    Kumar, A

    1999-01-01

    In the present work a comparative study of track registration response of sup 4 sup 0 Ar ions in different types of Makrofol polycarbonates viz. Makrofol-KG, KL and N have been done. The etched track parameters viz. bulk etch rate, track etch rate, etch rate ratio, cone angle and etching efficiency were calculated. The variation of etching rates with temperature were found to be exponential and follow the Arrhenius equation. The values of activation energy for bulk and track etching were also calculated. Maximum etchable track length/range were also obtained and compared with the theoretical values obtained from computer program RANGE. From the results it is found that the polycarbonates having same chemical composition manufactured by different chemical processes have slightly different behavior

  5. Biomass carbon micro/nano-structures derived from ramie fibers and corncobs as anode materials for lithium-ion and sodium-ion batteries

    International Nuclear Information System (INIS)

    Jiang, Qiang; Zhang, Zhenghao; Yin, Shengyu; Guo, Zaiping; Wang, Shiquan; Feng, Chuanqi

    2016-01-01

    Highlights: • Ramie fibers and corncobs are used as precursors to prepare the biomass carbons. • The ramie fiber carbon (RFC) took on morphology of 3D micro-rods. • The corncob carbon (CC) possessed a 2D nanosheets structure. • Both RFC and CC exhibited outstanding electrochemical performances in LIBs and SIBs systems. - Abstract: Three-dimensional (3D) rod-like carbon micro-structures derived from natural ramie fibers and two-dimensional (2D) carbon nanosheets derived from corncobs have been fabricated by heat treatment at 700 °C under argon atomsphere. The structure and morphology of the as-obtained ramie fiber carbon (RFC) and corncob carbon (CC) were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) technique. The electrochemical performances of the biomass carbon-based anode in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) were investigated. When tested as anode material for lithium ion batteries, both the RFC microrods and CC nanosheets exhibited high capacity, excellent rate capability, and stable cyclability. The specific capacity were still as high as 489 and 606 mAhg −1 after 180 cycles when cycled at room temperature in a 3.0–0.01 V potential (vs. Li/Li + ) window at current density of 100 mAg −1 , respectively, which are much higher than that of graphite (375 mAhg −1 ) under the same current density. Although the anodes in sodium ion batteries showed poorer specific capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 122 and 139 mAhg −1 with similar cycling stability. The feature of stable cycling performance makes the biomass carbon derived from natural ramie fibers and corncobs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries.

  6. Removal of nitrate ions from water by activated carbons (ACs)—Influence of surface chemistry of ACs and coexisting chloride and sulfate ions

    Science.gov (United States)

    Ota, Kazunari; Amano, Yoshimasa; Aikawa, Masami; Machida, Motoi

    2013-07-01

    Adsorptive removal of nitrate ions in aqueous solution using activated carbons (ACs) was examined. After ash was removed from Filtrasorb 400 AC, oxidation and outgassing and several heat treatments were carried out to modify the textural and surface properties of ACs. AC oxidized with 8 M nitric acid followed by outgassing at 900 °C (Ox-9OG) exhibited the greatest Langmuir adsorption capacity and affinity for nitrate removal among the total 7 ACs examined. Influence of coexisting chloride and sulfate ions was investigated as well to inspect the nitrate adsorption sites. The highest amount of sites which adsorbed nitrate ions exclusively could be observed for Ox-9OG adsorbent even though as great as 250 times greater number of chloride or sulfate ions over nitrate ions were present in the same aqueous system. Some basic oxygen species on carbon were estimated to work as selective adsorption sites for nitrate ions.

  7. Removal of Heavy Metal Ions with Acid Activated Carbons Derived from Oil Palm and Coconut Shells.

    Science.gov (United States)

    Rahman, Mokhlesur M; Adil, Mohd; Yusof, Alias M; Kamaruzzaman, Yunus B; Ansary, Rezaul H

    2014-05-07

    In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II), lead(II) and chromium(VI). Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hydrated iron oxide. The adsorption equilibrium data for nickel(II) and lead(II) were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II) and lead(II). The removal of chromium(VI) was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II), Pb(II) and Cr(VI) by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model.

  8. Removal of Heavy Metal Ions with Acid Activated Carbons Derived from Oil Palm and Coconut Shells

    Directory of Open Access Journals (Sweden)

    Mokhlesur M. Rahman

    2014-05-01

    Full Text Available In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II, lead(II and chromium(VI. Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hydrated iron oxide. The adsorption equilibrium data for nickel(II and lead(II were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II and lead(II. The removal of chromium(VI was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II, Pb(II and Cr(VI by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model.

  9. Removal of Heavy Metal Ions with Acid Activated Carbons Derived from Oil Palm and Coconut Shells

    Science.gov (United States)

    Rahman, Mokhlesur M.; Adil, Mohd; Yusof, Alias M.; Kamaruzzaman, Yunus B.; Ansary, Rezaul H.

    2014-01-01

    In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II), lead(II) and chromium(VI). Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hydrated iron oxide. The adsorption equilibrium data for nickel(II) and lead(II) were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II) and lead(II). The removal of chromium(VI) was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II), Pb(II) and Cr(VI) by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model. PMID:28788640

  10. Comparison of DMSP cross-track ion drifts and SuperDARN line-of-sight velocities

    Directory of Open Access Journals (Sweden)

    R. A. Drayton

    2005-10-01

    Full Text Available Cross-track ion drifts measured by the DMSP satellites are compared with line-of-sight SuperDARN HF velocities in approximately the same directions. Good overall agreement is found for a data set comprising of 209 satellite passes over the field of view of nine SuperDARN radars in both the Northern and Southern Hemispheres. The slope of the best linear fit line relating the SuperDARN and DMSP velocities is of the order of 0.7 with a tendency for SuperDARN velocities to be smaller. The agreement implies that the satellite and radar data can be merged into a common set provided that spatial and temporal variations of the velocity as measured by both instruments are smooth.

    Keywords. Ionosphere (Ionospheric irregularities; Plasma convection; Auroral ionosphere

  11. Experimental investigations on carbon ion scanning radiography using a range telescope

    International Nuclear Information System (INIS)

    Rinaldi, I; Jäkel, O; Parodi, K; Brons, S; Voss, B

    2014-01-01

    Ion beams offer an excellent tumor-dose conformality due to their inverted depth-dose profile and finite range in tissue, the Bragg peak (BP). However, they introduce sensitivity to range uncertainties. Imaging techniques play an increasingly important role in ion beam therapy to support precise diagnosis and identification of the target volume at the planning stage as well as to ensure the correspondence between the planning and treatment situation at the actual irradiation. For the purpose of improved treatment quality, ion-based radiographic images could be acquired at the treatment site before or during treatment and be employed to monitor the patient positioning and to check the patient-specific ion range. This work presents the initial experimental investigations carried out to address the feasibility of carbon ion radiography at the Heidelberg ion therapy center using a prototype range telescope set-up and an active raster scanning ion beam delivery system. Bragg curves are measured with a stack of ionization chambers (IC) synchronously to the beam delivery. The position of the BP is extracted from the data by locating the channel of maximum current signal for each delivered beam. Each BP is associated to the lateral and vertical positions of the scanned raster point extrapolated from the beam monitor system to build up a radiography. The radiographic images are converted into water equivalent thickness (WET) based on two calibrations of the detector. Radiographies of two phantoms of different complexities are reconstructed and their image quality is analyzed. A novel method proposed to increase the nominal range resolution of the IC stack is applied to the carbon ion radiography of an Alderson head phantom. Moreover, an x-ray digitally reconstructed radiography of the same anthropomorphic head phantom is converted in WET through the clinically used ion range calibration curve and compared with the carbon ion radiography based on a γ-index approach

  12. Validation of recent Geant4 physics models for application in carbon ion therapy

    CERN Document Server

    Lechner, A; Ivanchenko, V N

    2010-01-01

    Cancer treatment with energetic carbon ions has distinct advantages over proton or photon irradiation. In this paper we present a simulation model integrated into the Geant4 Monte Carlo toolkit (version 9.3) which enables the use of ICRU 73 stopping powers for ion transport calculations. For a few materials, revised ICRU 73 stopping power tables recently published by ICRU (P. Sigmund, A. Schinner, H. Paul, Errata and Addenda: ICRU Report 73 (Stopping of Ions Heavier than Helium), International Commission on Radiation Units and Measurements, 2009) were incorporated into Geant4, also covering media like water which are of importance in radiotherapeutical applications. We examine, with particular attention paid to the recent developments, the accuracy of current Geant4 models for simulating Bragg peak profiles of C-12 ions incident on water and polyethylene targets. Simulated dose distributions are validated against experimental data available in the literature, where the focus is on beam energies relevant to io...

  13. Fluid breakup in carbon nanotubes: An explanation of ultrafast ion transport

    Science.gov (United States)

    Gao, Xiang; Zhao, Tianshou; Li, Zhigang

    2017-09-01

    Ultrafast ion transport in carbon nanotubes (CNTs) has been experimentally observed, but the underlying mechanism is unknown. In this work, we investigate ion transport in CNTs through molecular dynamics (MD) simulations. It is found that the flow in CNTs undergoes a transition from the passage of a continuous liquid chain to the transport of isolated ion-water clusters as the CNT length or the external electric filed strength is increased. The breakup of the liquid chain in CNTs greatly reduces the resistance caused by the hydrogen bonds of water and significantly enhances the ionic mobility, which explains the two-order-magnitude enhancement of ionic conductance in CNTs reported in the literature. A theoretical criterion for fluid breakup is proposed, which agrees well with MD results. The fluid breakup phenomenon provides new insights into enhancing ion transport in nanoconfinements.

  14. Measuring the radial density distribution of light emission around the track of fast ions in nitrogen

    International Nuclear Information System (INIS)

    Ibach, T.

    1983-01-01

    For analysing the emission and stopping of ionization electrons (σ-electrons) emitted by fast ions passing through a gas, the radial density distribution of the light emission of the (0,0) transition of two optical bands in nitrogen have been measured. The systems selected for the epxeriments are the 2nd positive system (2.PS) at 337.1 nm primarily excited by low-energy electrons of about 20 eV, and the first negative system (1.NS) at 391.4 nm excited by faster electrons and simultaneous ionization. The equipment developed for the experiments records the light emission with a telescope-type optical arrangement including interference filters, allowing high local resolution and dynamics of the measured range. The measurements have been carried out at pressures between 0.133 and 13.3 mbar, using photons of energies ranging from 270 keV to 2.8 MeV, helium 3 beams of 270 keV/u and 500 keV/u, and neon beams of 270 keV/u. Abel's inversion applied to the distance functions allows calculation of the spatial light emission density which is normalized for a gas density of 1 g/cm 3 . The profiles of the two bands indicate that the σ-electron spectrum gets harder in outward direction. Next to the beam the impact density decreases faster with increasing ion energy than the stopping power (increasing interaction range of the σ-electrons). With photon beams, about half of the whole light emission in the 1. NS, and of the ionization, is induced by primary interactions of the ion beam. This proportion decreases at constant energy per nucleon with increasing atomic number of the ions as compared with the σ-electrons. The primary σ-emission gets harder with higher atomic numbers. (orig./HP) [de

  15. Femto-clock for the electron kinetics in swift heavy ion tracks

    Czech Academy of Sciences Publication Activity Database

    Medvedev, Nikita; Volkov, A.E.

    2017-01-01

    Roč. 50, č. 44 (2017), s. 1-11, č. článku 445302. ISSN 0022-3727 R&D Projects: GA MŠk LG15013; GA MŠk(CZ) LM2015083 Institutional support: RVO:68378271 Keywords : swift heavy ions * electron kinetics * femto-clock * femtosecond resolution * spectroscopy * radiative decay Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.588, year: 2016

  16. Diode-like single-ion track membrane prepared by electro-stopping

    International Nuclear Information System (INIS)

    Apel, P.Yu.; Korchev, Yu.E.; Siwy, Z.; Spohr, R.; Yoshida, M.

    2001-01-01

    The preparation of an asymmetric membrane in poly(ethylene terephthalate) (PET) is described, using a combination of chemical and electro-stopping. For this purpose, a single-ion-irradiated PET film is inserted into an electrolytic cell and etched from one side in 9 M sodium hydroxide while bathing the other side in a mixture of 2 M KCl and 2 M HCOOH (1:1 by volume), electrically retracting the OH - ions from the tip of the etch pit during pore break-through. When a preset current has been reached, the etch process is interrupted by replacing the etching solution with acidic 1 M potassium chloride solution. After etching, the current-voltage (I-V) characteristic is determined under symmetric bathing conditions, immersing both sides of the membrane in KCl solutions of identical concentration (0.01-1 M) and pH (3-8). The I-V characteristic is strongly non-linear, comparable to that of an electrical diode. If the polarity during etching is reversed, pushing the OH - ions into the tip of the etch pit, the resulting pores are larger and the degree of asymmetry smaller. The importance of electro-stopping is compared with chemical stopping

  17. SU-E-T-334: Track Structure Simulations of Charged Particles at Low and Intermediate Energies: Cross Sections Needs for Light and Heavy Ions

    Energy Technology Data Exchange (ETDEWEB)

    Dingfelder, M [East Carolina University, Greenville, NC (United States)

    2014-06-01

    Purpose/Methods: Monte Carlo (MC) track structure simulations follow the primary as well as all produced secondary particles in an event-by-event manner, from starting or ejection energy down to total stopping. They provide useful information on physics and chemistry of the biological response to radiation. They depend on reliable interaction cross sections and transport models of the considered radiation quality with biologically relevant materials. Most transport models focus on sufficiently fast and bare (i.e., fully ionized) ions and cross sections calculated within the (relativistic) first Born or Bethe approximations. These theories consider the projectile as a point particle and rely on proton cross sections and simple charge-scaling methods; they neglect the atomic nature of the ion and break down at low and intermediate ion energies. Heavier ions are used in particle therapy and slow to intermediate and low energies in the biologically interesting Bragg peak. Lighter and slower fragment ions, including alpha particles, protons, and neutrons are also produced in nuclear and break up reactions of charged particles. Secondary neutrons also produce recoil protons and ions, mainly in the intermediate energy range. Results/Conclusion: This work reviews existing models for track structure simulations and cross section calculations for light and heavy ions focusing on the low and intermediate energy range. It also presents new and updated aspects on cross section calculations and simulation techniques for ions and discusses the need for new models, calculations, and experimental data.

  18. Limitations of disordered carbons obtained from biomass as anodes for real lithium-ion batteries.

    Science.gov (United States)

    Caballero, Alvaro; Hernán, Lourdes; Morales, Julián

    2011-05-23

    Two disordered microporous carbons were obtained from two different types of biomass residues: olive and cherry stones. The former (OS) was activated physically under steam while the latter (CS) chemically with an aqueous solution of ZnCl(2). Their structural and textural properties were studied by X-ray diffraction, scanning electron microscopy, and N(2) adsorption/desorption. Although the samples possess similar textural properties (BET surface areas, micropore surfaces and volumes), the CS carbon is more disordered than the OS carbon. Their electrochemical response in half-cells (CS[OS]/Li) is good; the values are comparable to those obtained from mesocarbon microbeads commonly used in commercial lithium-ion batteries, which consist of highly graphitized carbon. However, cells featuring the OS or CS carbon as anode and LiMn(2)O(4) as cathode perform poorly. Electrochemical activation of the electrodes against lithium metal, a recommended procedure for boosting the electrochemical properties of real lithium-ion batteries, improves cell performance (particularly with OS) but is ultimately ineffective: the delivered average capacity of the activated cell made from OS was less than half its theoretical value. The high irreversible capacity, high polarization between the charge and discharge curves, combined with the presence of various functional groups and the high disorder of the studied carbons which may facilitate side reactions such as electrolyte decomposition, results in a degraded cell performance. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. submitter Next generation multi-scale biophysical characterization of high precision cancer particle radiotherapy using clinical proton, helium-, carbon- and oxygen ion beams

    CERN Document Server

    Dokic, Ivana; Niklas, Martin; Zimmermann, Ferdinand; Chaudhri, Naved; Krunic, Damir; Tessonnier, Thomas; Ferrari, Alfredo; Parodi, Katia; Jäkel, Oliver; Debus, Jürgen; Haberer, Thomas; Abdollahi, Amir

    2016-01-01

    The growing number of particle therapy facilities worldwide landmarks a novel era of precision oncology. Implementation of robust biophysical readouts is urgently needed to assess the efficacy of different radiation qualities. This is the first report on biophysical evaluation of Monte Carlo simulated predictive models of prescribed dose for four particle qualities i.e., proton, helium-, carbon- or oxygen ions using raster-scanning technology and clinical therapy settings at HIT. A high level of agreement was found between the in silico simulations, the physical dosimetry and the clonogenic tumor cell survival. The cell fluorescence ion track hybrid detector (Cell-Fit-HD) technology was employed to detect particle traverse per cell nucleus. Across a panel of radiobiological surrogates studied such as late ROS accumulation and apoptosis (caspase 3/7 activation), the relative biological effectiveness (RBE) chiefly correlated with the radiation species-specific spatio-temporal pattern of DNA double strand break ...

  20. Ion Beam Optimized Mechanical Characteristics of Glassy Polymeric Carbon for Medical Applications

    International Nuclear Information System (INIS)

    Rodrigues, M.G.; Cruz, N.C. da; Rangel, E.C.; Zimmerman, R.L.; Ila, D.; Poker, D.B.; Hensley, D.K.

    2003-01-01

    Glassy Polymeric Carbon (GPC) has medical applications owing to its inertness and biocompatible characteristics. Commercial GPC prosthetics include mitral, aortic and hydrocephalic valves. Surface treatment of GPC increases the adhesion of endothelic tissue on GPC and avoids the occurrence of thrombus in cardiac implant. In this work, ion beam was used to improve the mechanical characteristics of GPC surface. Hardness was measured as a function of depth in precursor and GPC samples heat treated from 300 to 2500 deg. C before and after bombardment with energetic ions of silicon, carbon, oxygen and gold at energies of 5, 6, 8 and 10 MeV and fluences between 1.0x1013 and 1.0x1016 ions/cm2. Comparison shows that hardness increases of the bombarded samples depend on heat treatment temperature. We verify that ion bombardment promotes carbonization due to an increased linkage between the chains of the polymeric material in lateral groups that are more numerous for samples heat treated to 700 deg. C

  1. Comparative Risk Predictions of Second Cancers After Carbon-Ion Therapy Versus Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Eley, John G., E-mail: jeley@som.umaryland.edu [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); University of Texas Graduate School of Biomedical Sciences, Houston, Texas (United States); Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland (United States); Friedrich, Thomas [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Homann, Kenneth L.; Howell, Rebecca M. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); University of Texas Graduate School of Biomedical Sciences, Houston, Texas (United States); Scholz, Michael; Durante, Marco [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Newhauser, Wayne D. [Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, Louisiana (United States); Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana (United States)

    2016-05-01

    Purpose: This work proposes a theoretical framework that enables comparative risk predictions for second cancer incidence after particle beam therapy for different ion species for individual patients, accounting for differences in relative biological effectiveness (RBE) for the competing processes of tumor initiation and cell inactivation. Our working hypothesis was that use of carbon-ion therapy instead of proton therapy would show a difference in the predicted risk of second cancer incidence in the breast for a sample of Hodgkin lymphoma (HL) patients. Methods and Materials: We generated biologic treatment plans and calculated relative predicted risks of second cancer in the breast by using two proposed methods: a full model derived from the linear quadratic model and a simpler linear-no-threshold model. Results: For our reference calculation, we found the predicted risk of breast cancer incidence for carbon-ion plans-to-proton plan ratio, , to be 0.75 ± 0.07 but not significantly smaller than 1 (P=.180). Conclusions: Our findings suggest that second cancer risks are, on average, comparable between proton therapy and carbon-ion therapy.

  2. Surface changes of nanotopography by carbon ion implantation to enhance the biocompatibility of silicone rubber: an in vitro study of the optimum ion fluence and adsorbed protein.

    Science.gov (United States)

    Li, Xianhui; Zhou, Xin; Chen, Yao; Yu, Shu; Chen, Xin; Xia, Xin; Shi, Xiaohua; Zhang, Yiming; Fan, Dongli

    2017-09-15

    Lower cellular adhesion and dense fibrous capsule formation around silicone breast implants caused by lower biocompatibility is a serious clinical problem. Preliminary work has shown that ion implantation enhances cell adhesion. Whether the biocompatibility is further enhanced by higher doses of carbon ion implantation and the mechanism by which ion implantation enhances biocompatibility remain unclear. In this study, five doses of carbon ions, which gradually increase, were implanted on the surface of silicone rubber and then the surface characteristics were surveyed. Then, cell adhesion, proliferation and migration were investigated. Furthermore, the vitronectin (VN) protein was used as a model protein to investigate whether the ion implantation affected the adsorbed protein on the surface. The obtained results indicate that enhanced cytocompatibility is dose dependent when the doses of ion implantation are less than 1 × 10 16  ions/cm 2 . However, when the doses of ion implantation are more than 1 × 10 16  ions/cm 2 , enhanced cytocompatibility is not significant. In addition, surface physicochemical changes by ion implantation induced a conformational change of the adsorbed vitronectin protein that enhanced cytocompatibility. Together, these results suggest that the optimum value of carbon ion implantation in silicone rubber to enhance biocompatibility is 1 × 10 16  ions/cm 2 , and ion implantation regulates conformational changes of adsorbed ECM proteins, such as VN, and mediates the expression of intracellular signals that enhance the biocompatibility of silicone rubber. The results herein provide new insights into the surface modification of implant polymer materials to enhance biocompatibility. It has potentially broad applications in the biomedical field.

  3. Synthesis and application of ion imprinting polymer coated magnetic multi-walled carbon nanotubes for selective adsorption of nickel ion

    Science.gov (United States)

    He, Junnan; Shang, Hongzhou; Zhang, Xing; Sun, Xiaoran

    2018-01-01

    A novel nickel ion imprinted polymers (IIPs) based on multi-walled carbon nanotubes (MWCNTs) were synthesized inverse emulsion system, using chitosan(CS) and acrylic acid as the functional monomers, Ni (II) as the template, and N' N-methylene bis-acrylamide as the cross-linker. The chemical structure and morphological feature of the IIPs were characterized by scanning electron microscopy (SEM), Thermogravimetry (TG), X-ray diffraction (XRD), and Fourier transform infrared spectrometer (FTIR). The studies indicated that the gel layer was well grafted on the surface of MWCNTs. Studies on the adsorption ability of the IIPs, by atomic absorption spectrophotometry, demonstrated that IIPs possessed excellent adsorption and selective ability towards Ni (II), fitting to pseudo second-order kinetic isotherms and with a maximum capacity of 19.86 mg/g, and selectivity factor of 13.09 and 4.42. The electrochemical performance of ion imprinting carbon paste electrode (CPE/IIPs) was characterized by Cyclic voltammetry (CV). Studies have shown that CPE/IIPs showed excellent electrochemical performance.

  4. 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.

  5. Vertebrate tracks in Late Pleistocene-Holocene (?) carbonate aeolianites, Pafos, Cyprus

    DEFF Research Database (Denmark)

    Milàn, Jesper; Theodorou, Georgios; Loope, David B.

    2015-01-01

    , the dwarf elephant Elephas cypriotes Bate, 1902, a small carnivore Genetta plesictoides Bate, 1903, and (possibly) humans. Theexposed tracks are 5–15 cm in diameter, with a few tracks up to 23 cm in size. This range of size correlates well with the estimated foot size of dwarf hippopotami and dwarf...... elephants. This low-diversity, endemic is land fauna provides a unique opportunity to correlate tracks with trackmakers....

  6. Binding of nickel and zinc ions with activated carbon prepared from sugar cane fibre (Saccharum officinarum L.

    Directory of Open Access Journals (Sweden)

    E.U. Ikhuoria

    2007-04-01

    Full Text Available Activated carbon was prepared from sugar cane fibre by carbonizing at 500 oC for 30 minutes. This was followed by activation with ammonium chloride. The activated carbon was characterised in terms of pH, bulk density, ash content, surface area and surface charge. Equilibrium sorption of nickel and zinc ions by the activated carbon was studied using a range of metal ion concentrations. The sorption data was observed to have an adequate fit for the Langmuir isotherm equation. The level of metal ion uptake was found to be of the order: Ni2+ > Zn2+. The difference in the removal efficiency could be explained in terms of the hydration energy of the metal ions. The distribution coefficient for a range of concentration of the metal ions at the sorbent water interface is found to be higher than the concentration in the continuous phase.

  7. Effect of oxide ion concentration on the electrochemical oxidation of carbon in molten LiCl

    International Nuclear Information System (INIS)

    Yun, J. W.; Choi, I. K.; Park, Y. S.; Kim, W. H.

    2001-01-01

    The continuous measurement of lithium oxide concentration was required in DOR (Direct Oxide Reduction) process, which converts spent nuclear fuel to metal form, for the reactivity monitor and effective control of the process. The concentration of lithium oxide was measured by the electrochemical method, which was based on the phenomenon that carbon atoms of glassy carbon electrode electrochemically react with oxygen ions of lithium oxide in molten LiCl medium. From the results of electrode polarization experiments, the trend of oxidation rate of carbon atoms was classified into two different regions, which were proportional and non-proportional ones, dependent on the amount of lithium oxide. Below about 2.5 wt % Li 2 O, as the carbon atom ionization rate was fast enough for reacting with diffusing lithium oxide to the surface of carbon electrode. In this concentration range, the oxidation rate of carbon atoms was controlled by the diffusion of lithium oxide, and the concentration of lithium oxide could be measured by electrochemical method. But, above 2.5 wt % Li 2 O, the oxidation rate of carbon atoms was controlled by the applied electrochemical potential, because the carbon atom ionization rate was suppressed by the huge amounts of diffusing Li 2 O. Above this concentration, the electrochemical method was not applicable to determine the concentration of lithium oxide

  8. Room temperature diamond-like carbon coatings produced by low energy ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Markwitz, A., E-mail: a.markwitz@gns.cri.nz [Department for Ion Beam Technologies, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Mohr, B.; Leveneur, J. [Department for Ion Beam Technologies, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand)

    2014-07-15

    Nanometre-smooth diamond-like carbon coatings (DLC) were produced at room temperature with ion implantation using 6 kV C{sub 3}H{sub y}{sup +} ion beams. Ion beam analysis measurements showed that the coatings contain no heavy Z impurities at the level of 100 ppm, have a homogeneous stoichiometry in depth and a hydrogen concentration of typically 25 at.%. High resolution TEM analysis showed high quality and atomically flat amorphous coatings on wafer silicon. Combined TEM and RBS analysis gave a coating density of 3.25 g cm{sup −3}. Raman spectroscopy was performed to probe for sp{sup 2}/sp{sup 3} bonds in the coatings. The results indicate that low energy ion implantation with 6 kV produces hydrogenated amorphous carbon coatings with a sp{sup 3} content of about 20%. Results highlight the opportunity of developing room temperature DLC coatings with ion beam technology for industrial applications.

  9. Near-surface hydrogen depletion of diamond-like carbon films produced by direct ion deposition

    Science.gov (United States)

    Markwitz, Andreas; Gupta, Prasanth; Mohr, Berit; Hübner, René; Leveneur, Jerome; Zondervan, Albert; Becker, Hans-Werner

    2016-03-01

    Amorphous atomically flat diamond-like carbon (DLC) coatings were produced by direct ion deposition using a system based on a Penning ion source, butane precursor gas and post acceleration. Hydrogen depth profiles of the DLC coatings were measured with the 15N R-NRA method using the resonant nuclear reaction 1H(15N, αγ)12C (Eres = 6.385 MeV). The films produced at 3.0-10.5 kV acceleration voltage show two main effects. First, compared to average elemental composition of the film, the near-surface region is hydrogen depleted. The increase of the hydrogen concentration by 3% from the near-surface region towards the bulk is attributed to a growth model which favours the formation of sp2 hybridised carbon rich films in the film formation zone. Secondly, the depth at which the maximum hydrogen concentration is measured increases with acceleration voltage and is proportional to the penetration depth of protons produced by the ion source from the precursor gas. The observed effects are explained by a deposition process that takes into account the contributions of ion species, hydrogen effusion and preferential displacement of atoms during direct ion deposition.

  10. Near-surface hydrogen depletion of diamond-like carbon films produced by direct ion deposition

    Energy Technology Data Exchange (ETDEWEB)

    Markwitz, Andreas, E-mail: A.Markwitz@gns.cri.nz [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Gupta, Prasanth [GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Mohr, Berit [GNS Science, Lower Hutt (New Zealand); Hübner, René [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Leveneur, Jerome; Zondervan, Albert [GNS Science, Lower Hutt (New Zealand); Becker, Hans-Werner [RUBION, Ruhr-University Bochum (Germany)

    2016-03-15

    Amorphous atomically flat diamond-like carbon (DLC) coatings were produced by direct ion deposition using a system based on a Penning ion source, butane precursor gas and post acceleration. Hydrogen depth profiles of the DLC coatings were measured with the 15N R-NRA method using the resonant nuclear reaction {sup 1}H({sup 15}N, αγ){sup 12}C (E{sub res} = 6.385 MeV). The films produced at 3.0–10.5 kV acceleration voltage show two main effects. First, compared to average elemental composition of the film, the near-surface region is hydrogen depleted. The increase of the hydrogen concentration by 3% from the near-surface region towards the bulk is attributed to a growth model which favours the formation of sp{sup 2} hybridised carbon rich films in the film formation zone. Secondly, the depth at which the maximum hydrogen concentration is measured increases with acceleration voltage and is proportional to the penetration depth of protons produced by the ion source from the precursor gas. The observed effects are explained by a deposition process that takes into account the contributions of ion species, hydrogen effusion and preferential displacement of atoms during direct ion deposition.

  11. Carbon Contamination During Ion Irradiation - Accurate Detection and Characterization of its Effect on Microstructure of Ferritic/Martensitic Steels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing; Toloczko, Mychailo B.; Kruska, Karen; Schreiber, Daniel K.; Edwards, Danny J.; Zhu, Zihua; Zhang, Jiandong

    2017-11-17

    Accelerator-based ion beam techniques have been used to study radiation effects in materials for decades. Although carbon contamination induced by ion beam in target materials is a well-known issue, it has not been fully characterized nor quantified for studies in ferritic/martensitic (F/M) steels that are candidate materials for applications such as core structural components in advanced nuclear reactors. It is an especially important issue for this class of material because of the effect of carbon level on precipitate formation. In this paper, the ability to quantify carbon contamination using three common techniques, namely time-of-flight secondary ion mass spectroscopy (ToF-SIMS), atom probe tomography (APT) and transmission electron microscopy (TEM) is compared. Their effectiveness and short-comings in determining carbon contamination will be presented and discussed. The corresponding microstructural changes related to carbon contamination in ion irradiated F/M steels are also presented and briefly discussed.

  12. Coupled chemical reactions in dynamic nanometric confinement: IV. Ion transmission spectrometric analysis of nanofluidic behavior and membrane formation during track etching in polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Vacík, Jiří; Hnatowicz, Vladimír; Munoz, G. H.; Arellano, H. G.; Kiv, A.; Alfonta, L.

    2015-01-01

    Roč. 170, č. 3 (2015), s. 155-174 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : ions * etching * tracks Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.472, year: 2015

  13. Coupled chemical reactions in dynamic nanometric confinement: V. The influence of Li+ and F- ions on etching of nuclear tracks in polymers

    Czech Academy of Sciences Publication Activity Database

    Fink, Dietmar; Hernandez, G. M.; Ruiz, N. L.; Vacík, Jiří; Hnatowicz, Vladimír; Garcia-Arellano, H.; Alfonta, L.; Kiv, A.

    2014-01-01

    Roč. 169, č. 5 (2014), s. 396-417 ISSN 1042-0150 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : tracks * biotechnology * nanostruct * ions * etching Subject RIV: BO - Biophysics Impact factor: 0.513, year: 2014

  14. Highly stable carbon coated Mg2Si intermetallic nanoparticles for lithium-ion battery anode

    Science.gov (United States)

    Tamirat, Andebet Gedamu; Hou, Mengyan; Liu, Yao; Bin, Duan; Sun, Yunhe; Fan, Long; Wang, Yonggang; Xia, Yongyao

    2018-04-01

    Silicon is an ideal candidate anode material for Li-ion batteries (LIBs). However, it suffers from rapid capacity fading due to large volume expansion upon lithium insertion. Herein, we design and fabricate highly stable carbon coated porous Mg2Si intermetallic anode material using facile mechano-thermal technique followed by carbon coating using thermal vapour deposition (TVD), toluene as carbon source. The electrode exhibits an excellent first reversible capacity of 726 mAh g-1 at a rate of 100 mA g-1. More importantly, the electrode demonstrates high rate capability (380 mAh g-1 at high rate of 2 A g-1) as well as high cycle stability, with capacity retentions of 65% over 500 cycles. These improvements are attributable to both Mg supporting medium and the uniform carbon coating, which can effectively increase the conductivity and electronic contact of the active material and protects large volume alterations during the electrochemical cycling process.

  15. Characterization of the passivation layer on disordered carbons in lithium-ion cells

    Energy Technology Data Exchange (ETDEWEB)

    Guidotti, R.; Johnson, B.

    1995-12-01

    Intercalation anodes of graphite or disordered carbon in rechargeable Li-ion batteries (based on aprotic organic solvents) develop a passivating film during the first intercalation of Li{sup +}. The formation of this film reduces the cycling efficiency and results in excessive consumption of Li{sup +}. The exact nature of this film is not well defined, although there are many similarities in properties to the films that form on Li anodes under similar cycling conditions. In this study we report on characterization studies of films formed during galvanostatic cycling of disordered carbons derived from polymethylacryolintrile (PMAN) in a 1M LiPF{sub 6} solution in ethylene carbonateldimethyl carbonate solution (1:1 by vol.). Complementary tests were also conducted with glass carbon, where intercalation cannot occur. Complex-impedance spectroscopy was the primary measurement technique, supplemented by cyclic voltammetry.

  16. A Monte Carlo evaluation of carbon and lithium ions dose distributions in water.

    Science.gov (United States)

    Taleei, Reza; Hultqvist, Martha; Gudowska, Irena; Nikjoo, Hooshang

    2012-01-01

    To compare dose distributions on the central- and off-axis for (12)C and (7)Li ion beams simulated by the codes SHIELD-HIT (Heavy Ion Transport) and FLUKA (FLUKtuierende KAskade), and compare with experimental data for 300 MeV/u (12)C and 185 MeV/u (7)Li ion beams. The general purpose Monte Carlo codes, SHIELD-HIT10 and FLUKA 2008.3d.1 were used for the ion dose distribution calculations. SHIELD-HIT transports hadrons and atomic nuclei of arbitrary charge and mass number in an energy range from 1 keV/u up to 1 GeV/u. Similarly, FLUKA transports charged hadrons in an energy range from 100 keV up to 20 TeV. Neutrons are transported down to thermal energies in both codes. Inelastic nuclear interactions are modelled in SHIELD-HIT by the Many Stage Dynamical Model (MSDM), whereas in FLUKA the Pre-Equilibrium Approach to Nuclear Thermalisation (PEANUT) package which includes a Generalized Intra-Nuclear Cascade model was used. The dose distributions in water irradiated with 300 MeV/u (12)C and 185 MeV/u (7)Li ion beams were simulated with the two codes. Studies were performed of the energy deposition both on the central axis and at lateral distances up to 10 cm off-axis. The dose distributions calculated by SHIELD-HIT and FLUKA were compared with published experimental data. The dose mean lineal energy [Formula: see text], frequency mean lineal energy [Formula: see text], dose mean specific energy [Formula: see text], and frequency mean specific energy [Formula: see text] were calculated with the ion track-structure code PITS99 (Positive Ion Track Structure 99), coupled with the electron code KURBUC for the primary and secondary ions average energies at 1 mm before the Bragg peak. The Monte Carlo codes show good agreement with experimental results for off-axis dose distributions. The disagreements in the Bragg peak region for the central-axis dose distributions imply that further improvements especially in the nuclear interaction models are required to increase the

  17. Tailoring the pore alignment for rapid ion transport in microporous carbons.

    Science.gov (United States)

    Kajdos, Adam; Kvit, Alexander; Jones, Frank; Jagiello, Jacek; Yushin, Gleb

    2010-03-17

    The power density and charge-discharge time of electrical double layer capacitors are largely determined by how fast the electrolyte ions can travel within the carbon electrode particles. Our systematic studies using zeolite-templated carbons show that an enhancement in ion transport rate by more than 2 orders of magnitude is possible by minimizing the micropore tortuosity. Very uniform carbon deposition was achieved using a well-controlled process involving the decomposition of acetylene precursor at a reduced pressure of 10 Torr and under a constant flow rate of 100 sccm. Selected carbon samples with well-aligned, straight micropores demonstrate high specific capacitance of up to 300 F/g and outstanding frequency response of up to 10 Hz for 250 microm thick electrodes, indicating an attractive combination of high specific energy and high specific power in electrical double layer capacitors. Such properties are critical for many peak-power hungry applications, such as the leveling of subsecond disturbances in power lines. Our findings provide guidance for the optimal design of porous carbons with greatly improved power storage characteristics.

  18. Nitrogen-Doped Carbon for Red Phosphorous Based Anode Materials for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jiaoyang Li

    2018-01-01

    Full Text Available Serving as conductive matrix and stress buffer, the carbon matrix plays a pivotal role in enabling red phosphorus to be a promising anode material for high capacity lithium ion batteries and sodium ion batteries. In this paper, nitrogen-doping is proved to effective enhance the interface interaction between carbon and red phosphorus. In detail, the adsorption energy between phosphorus atoms and oxygen-containing functional groups on the carbon is significantly reduced by nitrogen doping, as verified by X-ray photoelectron spectroscopy. The adsorption mechanisms are further revealed on the basis of DFT (the first density functional theory calculations. The RPNC (red phosphorus/nitrogen-doped carbon composite material shows higher cycling stability and higher capacity than that of RPC (red phosphorus/carbon composite anode. After 100 cycles, the RPNC still keeps discharge capacity of 1453 mAh g−1 at the current density of 300 mA g−1 (the discharge capacity of RPC after 100 cycles is 1348 mAh g−1. Even at 1200 mA g−1, the RPNC composite still delivers a capacity of 1178 mAh g−1. This work provides insight information about the interface interactions between composite materials, as well as new technology develops high performance phosphorus based anode materials.

  19. Nitrogen-Doped Carbon for Red Phosphorous Based Anode Materials for Lithium Ion Batteries

    Science.gov (United States)

    Li, Jiaoyang; Qian, Yumin

    2018-01-01

    Serving as conductive matrix and stress buffer, the carbon matrix plays a pivotal role in enabling red phosphorus to be a promising anode material for high capacity lithium ion batteries and sodium ion batteries. In this paper, nitrogen-doping is proved to effective enhance the interface interaction between carbon and red phosphorus. In detail, the adsorption energy between phosphorus atoms and oxygen-containing functional groups on the carbon is significantly reduced by nitrogen doping, as verified by X-ray photoelectron spectroscopy. The adsorption mechanisms are further revealed on the basis of DFT (the first density functional theory) calculations. The RPNC (red phosphorus/nitrogen-doped carbon composite) material shows higher cycling stability and higher capacity than that of RPC (red phosphorus/carbon composite) anode. After 100 cycles, the RPNC still keeps discharge capacity of 1453 mAh g−1 at the current density of 300 mA g−1 (the discharge capacity of RPC after 100 cycles is 1348 mAh g−1). Even at 1200 mA g−1, the RPNC composite still delivers a capacity of 1178 mAh g−1. This work provides insight information about the interface interactions between composite materials, as well as new technology develops high performance phosphorus based anode materials. PMID:29342917

  20. Anodic polymerization of vinyl ethylene carbonate in Li-Ion battery electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Guoying; Zhuang, Guorong V.; Richardson, Thomas J.; Gao, Liu; Ross Jr., Philip N.

    2005-02-28

    A study of the anodic oxidation of vinyl ethylene carbonate (VEC) was conducted with post-mortem analysis of reaction products by ATR-FTIR and gel permeation chromatography (GPC). The half-wave potential (E1/2) for oxidation of VEC is ca. 3.6 V producing a resistive film on the electrode surface. GPC analysis of the film on a gold electrode produced by anodization of a commercial Li-ion battery electrolyte containing 2 percent VEC at 4.1 V showed the presence of a high molecular weight polymer. IR analysis indicated polycarbonate with alkyl carbonate rings linked by aliphatic methylene and methyl branches.

  1. Carbon-Coated SnO2 Nanorod Array for Lithium-Ion Battery Anode Material

    Directory of Open Access Journals (Sweden)

    Ji Xiaoxu

    2010-01-01

    Full Text Available Abstract Carbon-coated SnO2 nanorod array directly grown on the substrate has been prepared by a two-step hydrothermal method for anode material of lithium-ion batteries (LIBs. The structural, morphological and electrochemical properties were investigated by means of X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM and electrochemical measurement. When used as anodes for LIBs with high current density, as-obtained array reveals excellent cycling stability and rate capability. This straightforward approach can be extended to the synthesis of other carbon-coated metal oxides for application of LIBs.

  2. Fabrication of carbon nanotube nanogap electrodes by helium ion sputtering for molecular contacts

    International Nuclear Information System (INIS)

    Thiele, Cornelius; Vieker, Henning; Beyer, André; Gölzhäuser, Armin; Flavel, Benjamin S.; Hennrich, Frank; Muñoz Torres, David; Eaton, Thomas R.; Mayor, Marcel; Kappes, Manfred M.; Löhneysen, Hilbert v.

    2014-01-01

    Carbon nanotube nanogaps have been used to contact individual organic molecules. However, the reliable fabrication of a truly nanometer-sized gap remains a challenge. We use helium ion beam lithography to sputter nanogaps of only (2.8 ± 0.6) nm size into single metallic carbon nanotubes embedded in a device geometry. The high reproducibility of the gap size formation provides a reliable nanogap electrode testbed for contacting small organic molecules. To demonstrate the functionality of these nanogap electrodes, we integrate oligo(phenylene ethynylene) molecular rods, and measure resistance before and after gap formation and with and without contacted molecules

  3. Tetrapropylammonium ion influence on the synthesis of Pt Ru/carbon hybrids by hydrothermal carbonization

    International Nuclear Information System (INIS)

    Tusi, M.M.; Polanco, N.S.O.; Brandalise, M.; Correa, O.V.; Silva, A.C.; Oliveira Neto, A.; Linardi, M.; Spinace, E.V.

    2010-01-01

    PtRu/Carbon hybrid materials were prepared by hydrothermal carbonization using starch as carbon source and reducing agent and H 2 PtCl 6 .6H 2 O e RuCl 3 .xH 2 O as metals source and catalyst of the carbonization process. The materials were prepared in the following conditions: without pH adjustment, in the absence and in the presence of tetrapropylammonium chloride (TPACl), and adjusting the pH using potassium hydroxide (KOH) or tetrapropylammonium hydroxide (TPAOH). The obtained materials were treated under argon atmosphere at 900 deg C and characterized by SEM/EDX, BET isotherm, XRD and TEM. The electro-oxidation of methanol was studied by chronoamperometry. The material prepared using TPAOH showed the best performance for methanol electro-oxidation. (author)

  4. Adsorption of Chromium Ions by Acid Activated Low Cost Carbon-Kinetic,Thermodynamic and Equilibrium Studies

    Directory of Open Access Journals (Sweden)

    B. R. Venkatraman

    2009-01-01

    Full Text Available A carbonaceous adsorbent prepared from an indigenous waste, by acid treatment was tested for its efficiency in removing metal ions. The process parameters studied include agitation time, initial metal ions concentration, carbon dose, pH and temperature. The adsorption followed first order reaction equation and the rate is mainly controlled by intra-particle diffusion. Freundlich and Langmuir isotherm models were applied to the equilibrium data. The adsorption capacity (Qm obtained from the Langmuir isotherm plot were found to around 30 mg/g at an initial pH of 7.0. The temperature variation study showed that the metal ions adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. Significant effect on adsorption was observed on varying the pH of the metal ion solutions. The Langmuir and Freundlich adsorption isotherms obtained, positive ΔH0 value, pH dependent results and desorption of metal ions in mineral acid suggest that the adsorption of metal ions on BBC involves chemisorption as well as physisorption mechanism.

  5. Micro Li-ion capacitor with activated carbon/graphite configuration for energy storage

    Science.gov (United States)

    Li, Siwei; Wang, Xiaohong

    2015-05-01

    This paper presents an asymmetric micro Li-ion capacitor which is the integration of a supercapacitor electrode and a Li-ion battery electrode. It exploits the power of supercapacitor and the capacity of Li-ion battery, together with an extended cell potential. Activated carbon (AC) of the supercapacitor material is used to construct the positive electrode, graphite of the anode material in Li-ion battery is adopted in the negative electrode, and an electrolyte used in Li-ion battery, 1 M LiPF6 in organic solvent serves as the electrolyte in the device. The micro three-dimensional (3D) electrodes with separator are fabricated by using micro electro mechanical systems (MEMS) fabrication technology. A pre-lithiation of graphite electrode is then carried out to reduce the electrolyte needed when packaging the prototype and improve its performance. Measurements show that the Li-ion capacitor prototype with 100-μm-thick interdigital electrodes has a capacity of 180 μA h/cm2 and an energy density of about 1750 mJ/cm2 at a charge/discharge current of 0.5 mA/cm2. The energy density is much higher than the symmetric AC supercapacitor at the same size.

  6. Tuning the Solid Electrolyte Interphase for Selective Li- and Na-Ion Storage in Hard Carbon.

    Science.gov (United States)

    Soto, Fernando A; Yan, Pengfei; Engelhard, Mark H; Marzouk, Asma; Wang, Chongmin; Xu, Guiliang; Chen, Zonghai; Amine, Khalil; Liu, Jun; Sprenkle, Vincent L; El-Mellouhi, Fedwa; Balbuena, Perla B; Li, Xiaolin

    2017-05-01

    Solid-electrolyte interphase (SEI) films with controllable properties are highly desirable for improving battery performance. In this paper, a combined experimental and theoretical approach is used to study SEI films formed on hard carbon in Li- and Na-ion batteries. It is shown that a stable SEI layer can be designed by precycling an electrode in a desired Li- or Na-based electrolyte, and that ionic transport can be kinetically controlled. Selective Li- and Na-based SEI membranes are produced using Li- or Na-based electrolytes, respectively. The Na-based SEI allows easy transport of Li ions, while the Li-based SEI shuts off Na-ion transport. Na-ion storage can be manipulated by tuning the SEI layer with film-forming electrolyte additives, or by preforming an SEI layer on the electrode surface. The Na specific capacity can be controlled to Li ions is demonstrated by preforming an SEI layer on the electrode surface and corroborated with a mixed electrolyte. This work may provide new guidance for preparing good ion-selective conductors using electrochemical approaches. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Tuning the Solid Electrolyte Interphase for Selective Li- and Na-Ion Storage in Hard Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Fernando A. [Department of Chemical Engineering, Texas A& M University, College Station TX 77843-3122 USA; Yan, Pengfei [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Engelhard, Mark H. [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Marzouk, Asma [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, P.O. Box 5825 Doha Qatar; Wang, Chongmin [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Xu, Guiliang [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue Argonne IL 60439 USA; Chen, Zonghai [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue Argonne IL 60439 USA; Amine, Khalil [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue Argonne IL 60439 USA; Liu, Jun [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Sprenkle, Vincent L. [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; El-Mellouhi, Fedwa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, P.O. Box 5825 Doha Qatar; Balbuena, Perla B. [Department of Chemical Engineering, Texas A& M University, College Station TX 77843-3122 USA; Li, Xiaolin [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA

    2017-03-07

    Solid-electrolyte interphase (SEI) films with controllable properties are highly desirable for improving battery performance. In this paper, a combined experimental and theoretical approach is used to study SEI films formed on hard carbon in Li- and Na-ion batteries. It is shown that a stable SEI layer can be designed by precycling an electrode in a desired Li- or Na-based electrolyte, and that ionic transport can be kinetically controlled. Selective Li- and Na-based SEI membranes are produced using Li- or Na-based electrolytes, respectively. The Na-based SEI allows easy transport of Li ions, while the Li-based SEI shuts off Na-ion transport. Na-ion storage can be manipulated by tuning the SEI layer with film-forming electrolyte additives, or by preforming an SEI layer on the electrode surface. The Na specific capacity can be controlled to < 25 mAh g(-1); approximate to 1/10 of the normal capacity (250 mAh g(-1)). Unusual selective/ preferential transport of Li ions is demonstrated by preforming an SEI layer on the electrode surface and corroborated with a mixed electrolyte. This work may provide new guidance for preparing good ion-selective conductors using electrochemical approaches.

  8. Adsorption of Nickel Ion by Low Cost Carbon-Kinetic, Thermodynamic and Equilibrium Studies

    Directory of Open Access Journals (Sweden)

    V. Vijayakumaran

    2009-01-01

    Full Text Available A carbonaceous adsorbent prepared from an indigenous waste, by acid treatment was tested for its efficiency in removing nickel ion. The process parameters studied include agitation time, initial metal ion concentration, carbon dose, pH and temperature. The adsorption followed first order reaction equation and the rate is mainly controlled by intraparticle diffusion. Freundlich and Langmuir isotherm models were applied to the equilibrium data. The adsorption capacity (Qm obtained from the Langmuir isotherm plot were found to around 43 mg/g at an initial pH of 7.0. The temperature variation study showed that the nickel ions adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. Significant effect on adsorption was observed on varying the pH of the nickel ion solutions. The Langmuir and Freundlich adsorption isotherms obtained, positive ΔH0 value, pH dependent results and desorption of metal ions in mineral acid suggest that the adsorption of nickel ion on MCC involves chemisorption as well as physisorption mechanism.

  9. New anode material for lithium-ion cells produced by catalytic graphitization of glassy carbon at 1000 degrees C

    Energy Technology Data Exchange (ETDEWEB)

    Skowronski, J.M. [Poznan Univ. of Technology, Poznan (Poland). Inst. of Chemistry and Technical Electrochemistry; Central Lab. of Batteries and Cells, Poznan (Poland); Knofczynski, K. [Central Lab. of Batteries and Cells, Poznan (Poland)

    2006-10-15

    This study investigated the conversion of glassy carbon into graphite at relatively low temperature of 1000 degrees C under ambient pressure using iron powder as the catalyst. The composite product of reaction was a graphite and turbostratic carbon whose use was then examined in terms of application in lithium-ion cells. Glassy, hard carbon spheres of 10 to 15 {iota}m were prepared from phenolic resin in a nitrogen atmosphere and then subjected to heat treatment with an iron powder mixture. After cooling down to ambient temperature, the carbon/iron mixture was treated with diluted HCl solution to remove metallic additives. The modified carbon was then washed with distilled water until chloride ions disappeared in a filtrate. All samples were characterized using XRD analysis. Working electrodes for electrochemical measurements were made by mixing carbons with PVDF. Cyclic voltammograms recorded for unmodified and modified carbons were consistent with XRD measurements. SEM analysis revealed that the process of graphitization begins at the external regions of glassy carbon spheres where erosion occurs when the carbon reacts with iron particles. The surface destruction of carbon spheres progresses into the interior of the spheres, resulting in their collapse followed by the transformation into pallets resembling a stack of graphite sheets. It was noted that not all unorganized carbon was conversed to graphite. Rather, only 50 per cent of turbostratic carbon existed in the product of heat treatment. The product of graphitization appeared to be a promising material for the preparation of anodes for lithium-ion cells. The discharge capacity for carbon produced by catalytic treatment was found to be approximately 5 times higher, while the discharge/charge reversibility was 23 per cent higher than values obtained for untreated carbon. The study showed that the uptake of lithium ions by the original carbon depends on the insertion/deinsertion mechanism of hard carbon as well

  10. Lithium storage performance of carbon nanotubes prepared from polyaniline for lithium-ion batteries

    International Nuclear Information System (INIS)

    Xiang Xiaoxia; Huang Zhengzheng; Liu Enhui; Shen Haijie; Tian Yingying; Xie Hui; Wu Yuhu; Wu Zhilian

    2011-01-01

    Highlights: → Polyaniline nanotube is synthesized by the self-assembly method in aqueous media. → Carbon nanotubes were prepared from polyaniline nanotube by physical activation. → Activation leads to large surface area, and surface nitrogen and oxygen functional groups. → Such physical and chemical properties lead to the good electrochemical properties. → After 20 cycles, a reversible capacity of 728 mAh g -1 was obtained. - Abstract: Carbon nanotubes with large surface area and surface nitrogen and oxygen functional groups are prepared by carbonizing and activating of polyaniline nanotubes, which is synthesized by polymerization of aniline with the self-assembly method in aqueous media. The physicochemical properties of the carbon nanotubes are characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller, elemental analyses and X-ray photoelectron spectroscopy measurements. The surface area and pore diameter are 618.9 m 2 g -1 and 3.10 nm. The electrochemical properties of the carbon nanotubes as anode materials in lithium ion batteries are evaluated. At a current density of 100 mA g -1 , the activated carbon nanotube shows an enormously first discharge capacity of about 1370 mAh g -1 and a charge capacity of 907 mAh g -1 . After 20 cycling tests, the activated carbon nanotube retains a reversible capacity of 728 mAh g -1 . These indicate it may be a promising candidate for an anode material for lithium secondary batteries.

  11. Adsorption of naphthalene onto a high-surface-area carbon from waste ion exchange resin.

    Science.gov (United States)

    Shi, Qianqian; Li, Aimin; Zhu, Zhaolian; Liu, Bing

    2013-01-01

    A high-surface-area carbon (KC-1) was prepared from waste polystyrene-based ion exchange resin by KOH activation and used for naphthalene adsorption. The carbon exhibited a good hydrophobic nature with developed porous structure, favoring the adsorption of organic compounds. The Brunauer-Emmett-Teller surface area and total pore volume of KC-1 were 3442.2 and 1.68 cm3/g, respectively, which can be compared with those of KOH-activated carbons prepared from other precursors. Batch experiments were carried out to investigate the adsorption of naphthalene onto KC-1. The equilibrium data were analyzed by the Langmuir, Freundlich, and Polanyi-Manes isotherms and agreed with the Polanyi-Manes Model. The adsorption of naphthalene depended greatly on the porosity of the carbon, and the dispersive interactions between naphthalene and carbon could be relatively weak. The pH variation in aqueous solution had little effect on the adsorption process. The equilibrium time for 0.04 g/L of carbon dose was around 5 hr. Different models were used to evaluate the kinetic data and the pseudo second-order model was suitable to describe the kinetic process of naphthalene adsorption onto KC-1. Regeneration of spent carbon could be carried out effectively by alcohol treatment. The results indicated that KC-1 was a promising adsorbent for the removal of polycyclic aromatic hydrocarbons from aqueous solutions.

  12. Transformation from hollow carbon octahedra to compressed octahedra and their use in lithium-ion batteries

    International Nuclear Information System (INIS)

    Mei, Tao; Li, Na; Li, Qianwen; Xing, Zheng; Tang, Kaibin; Zhu, Yongchun; Qian, Yitai; Shen, Xiaoyan

    2012-01-01

    Graphical abstract: Schematic illustration of the transformation process from hollow carbon octahedra into deflated balloon-like compressed hollow carbon octahedra ▪. Highlights: ► We demonstrate the in situ template synthesis of hollow carbon octahedra. ► The shell thickness of hollow carbon octahedra is only 2.5 nm. ► Morphology transformation could be realized by extending of reaction time. ► The hollow structures show reversible capacity as 353 mAh g −1 after 100 cycles. -- Abstract: Hollow carbon octahedra with an average size of 300 nm and a shell thickness of 2.5 nm were prepared by a reaction starting from ferrocene and Mg(CH 3 COO) 2 ·4H 2 O at 700 °C for 10 h. They became compressed and turned into deflated balloon-like octahedra when the reaction time was increased to 16 h. It was proposed that the gas pressure generated during the reaction process induced the transformation from broken carbon hollow octahedra into deflated balloon-like compressed octahedra. X-ray powder diffraction and Raman spectroscopy indicate that the as-obtained carbon products possess a graphitic structure and high-resolution transmission electron microscopy images indicate that they have low crystallinity. Their application as an electrode shows reversible capacity of 353 mAh g −1 after 100 cycles in the charge/discharge experiments of secondary lithium ion batteries.

  13. Spectroscopic and redox properties of curium and californium ions in concentrated aqueous carbonate-bicarbonate media

    International Nuclear Information System (INIS)

    Hobart, D.E.; Varlashkin, P.G.; Samhoun, K.; Haire, R.G.; Peterson, J.R.

    1983-01-01

    Multimilligram quantities of trivalent curium-248 and californium-249 were investigated by absorption spectroscopy, cyclic voltammetry, and bulk solution electrolysis in concentrated aqueous carbonate-bicarbonate solution. Actinide concentrations between 10 -4 and 10 -2 M were studied in 2 M sodium carbonate and 5.5 M potassium carbonate solutions at pH values from 8 to 14. The solution absorption spectra of Cm(III) and Cf(III) in carbonate media are presented for the first time and compared to literature spectra of these species in noncomplexing aqueous solution. It was anticipated that carbonate complexation of the actinide ions could provide a sufficient negative shift in the formal potentials of the M(IV)/M(III) couples of Cm and Cf to permit the generation and stabilization of their tetravalent states in aqueous carbonate-bicarbonate medium. No conclusive evidence was found in the present work to indicate the existence of any higher oxidation states of curium or californium in carbonate solution. Some possible reasons for our inability to generate and detect oxidized species of curium and californium in this medium are discussed

  14. Swift heavy ion induced modifications of single walled carbon nanotube thin films

    Energy Technology Data Exchange (ETDEWEB)

    Vishalli, E-mail: vishalli_2008@yahoo.com [Department of Physics, Panjab University, Chandigarh 160014 (India); Raina, K.K. [Materials Research Laboratory, School of Physics and Materials Science, Thapar University, P.O. Box 32, Patiala 147004, Punjab (India); Avasthi, D.K. [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, P.O. Box 10502, New Delhi 110067 (India); Srivastava, Alok [Department of Chemistry, Panjab University, Chandigarh 160014 (India); Dharamvir, Keya [Department of Physics, Panjab University, Chandigarh 160014 (India)

    2016-04-15

    Thin films of single walled carbon nanotubes (SWCNTs) were prepared by Langmuir–Blodgett method and irradiated with swift heavy ions, carbon and nickel each of energy 60 MeV. The ion beams have different electronic energy loss (S{sub e}) values and the samples were exposed to various irradiation doses. The irradiated films were characterized using Raman and optical absorption spectroscopy. Raman spectroscopy results indicate the competing processes of defect creation and healing (annealing) of SWCNTs at lower fluences, while at higher fluences defect creation or damage dominates. In UV–Vis–NIR spectroscopy we find that there is decrease in the intensity of characteristic peaks with every increasing fluence, indicating decrease in the optically active states with irradiation.

  15. Diamond-Like Carbon Film Deposition Using DC Ion Source with Cold Hollow Cathode

    Directory of Open Access Journals (Sweden)

    E. F. Shevchenko

    2014-01-01

    Full Text Available Carbon diamond-like thin films on a silicon substrate were deposited by direct reactive ion beam method with an ion source based on Penning direct-current discharge system with cold hollow cathode. Deposition was performed under various conditions. The pressure (12–200 mPa and the plasma-forming gas composition consisting of different organic compounds and hydrogen (C3H8, CH4, Si(CH32Cl2, H2, the voltage of accelerating gap in the range 0.5–5 kV, and the substrate temperature in the range 20–850°C were varied. Synthesized films were researched using nanoindentation, Raman, and FTIR spectroscopy methods. Analysis of the experimental results was made in accordance with a developed model describing processes of growth of the amorphous and crystalline carbon materials.

  16. Silver(I Ions Ultrasensitive Detection at Carbon Electrodes―Analysis of Waters, Tobacco Cells and Fish Tissues

    Directory of Open Access Journals (Sweden)

    Sona Krizkova

    2009-09-01

    Full Text Available We used carbon paste electrodes and a standard potentiostat to detect silver ions. The detection limit (3 Signal/Noise ratio was estimated as 0.5 μM. A standard electrochemical instrument microanalysis of silver(I ions was suggested. As a working electrode a carbon tip (1 mL or carbon pencil was used. Limits of detection estimated by dilution of a standard were 1 (carbon tip or 10 nM (carbon pencil. Further we employed flow injection analysis coupled with carbon tip to detect silver(I ions released in various beverages and mineral waters. During first, second and third week the amount of silver(I ions releasing into water samples was under the detection limit of the technique used for their quantification. At the end of a thirteen weeks long experiment the content of silver(I ions was several times higher compared to the beginning of release detected in the third week and was on the order of tens of nanomoles. In subsequent experiments the influence of silver(I ions (0, 5 and 10 μM on a plant model system (tobacco BY-2 cells during a fourday exposition was investigated. Silver(I ions were highly toxic to the cells, which was revealed by a double staining viability assay. Moreover we investigated the effect of silver(I ions (0, 0.3, 0.6, 1.2 and 2.5 μM on guppies (Poecilia reticulata. Content of Ag(I increased with increasing time of the treatment and applied concentrations in fish tissues. It can be concluded that a carbon tip or carbon pencil coupled with a miniaturized potentiostat can be used for detection of silver(I ions in environmental samples and thus represents a small, portable, low cost and easy-to-use instrument for such purposes.

  17. Diamond-like carbon and nanocrystalline diamond film surfaces sputtered by argon cluster ion beams

    Czech Academy of Sciences Publication Activity Database

    Zemek, Josef; Jiříček, Petr; Houdková, Jana; Artemenko, Anna; Jelínek, Miroslav

    2016-01-01

    Roč. 68, Sep (2016), s. 37-41 ISSN 0925-9635 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2015088 Institutional support: RVO:68378271 Keywords : diamond-like carbon * nanocrystalline diamond * argon cluster ion beam * XPS * C sp2 * C sp3 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.561, year: 2016

  18. Structure of ion-plated amorphous hydrogenated carbon films investigated by electron energy loss spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Muehling, I.; Bewilogua, K.; Breuer, K. (Sektion Physik/Elektronische Bauelemente, Technische Univ., Karl-Marx-Stadt (German Democratic Republic))

    1990-05-15

    Thin ion-plated amorphous hydrogenated carbon films were investigated by electron energy loss spectroscopy. From an analysis of the dielectric function, information on the film structure could be obtained. The results will be compared with those of electron diffraction studies. Differences between insulating and conducting substrates could be verified in the film structure and are related to surface charging effects. From an analysis of the oscillator strength sum rule the content of C sp{sup 2} atoms was estimated. (orig.).

  19. Demonstrated Efficient Quasi-Monoenergetic Carbon-Ion Beams Approaching Fast Ignition (FI) Requirements

    Science.gov (United States)

    Fernández, Juan C.; Palaniyappan, S.; Huang, C.; Gautier, D. C.; Santiago, M.

    2015-11-01

    Using massive computer simulations of relativistic laser-plasma interactions, we have identified a self-organizing scheme that exploits persisting self-generated plasma electric (~TV/m) and magnetic (~104 Tesla) fields to reduce the ion energy spread of intense laser-driven ion beams after the laser exits the plasma. Consistent with the scheme, we have demonstrated on the LANL Trident laser carbon-ion beams with narrow spectral peaks at 220 MeV, with high conversion efficiency (~ 5%). These parameters are within a factor of 2 of FI requirements. The remaining gap may be bridged by increasing the laser intensity by a factor of 4, according to our data. We also discuss how this beam may be focused, to address the remaining requirement for FI, besides the total laser energy. This work is sponsored by the LANL LDRD Program.

  20. Ion field-evaporation from ionic liquids infusing carbon xerogel microtips

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Martinez, C. S., E-mail: carlita@mit.edu; Lozano, P. C. [Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-07-27

    Ionic liquid ion sources capable of producing positive and negative molecular ion beams from room-temperature molten salts have applications in diverse fields, from materials science to space propulsion. The electrostatic stressing of these ionic liquids places the liquid surfaces in a delicate balance that could yield unwanted droplet emission when not properly controlled. Micro-tip emitter configurations are required to guarantee that these sources will operate in a pure ionic regime with no additional droplets. Porous carbon based on resorcinol-formaldehyde xerogels is introduced as an emitter substrate. It is demonstrated that this material can be shaped to the required micron-sized geometry and has appropriate transport properties to favor pure ionic emission. Time-of-flight mass spectrometry is used to verify that charged particle beams contain solvated ions exclusively.

  1. Moist synoptic transport of carbon dioxide along midlatitude storm tracks, transport uncertainty, and implications for carbon dioxide flux estimation

    Science.gov (United States)

    Parazoo, Nicholas C.

    Mass transport along moist isentropic surfaces on baroclinic waves represents an important component of the atmospheric heat engine that operates between the equator and poles. This is also an important vehicle for tracer transport, and is correlated with ecosystem metabolism because large-scale baroclinicity and photosynthesis are both driven seasonally by variations in solar radiation. In this research, I pursue a dynamical framework for explaining atmospheric transport of CO2 by synoptic weather systems at middle and high latitudes. A global model of atmospheric tracer transport, driven by meteorological analysis in combination with a detailed description of surface fluxes, is used to create time varying CO2 distributions in the atmosphere. Simulated mass fluxes of CO2 are then decomposed into a zonal monthly mean component and deviations from the monthly mean in space and time. Mass fluxes of CO2 are described on moist isentropic surfaces to represent frontal transport along storm tracks. Forward simulations suggest that synoptic weather systems transport large amounts of CO2 north and south in northern mid-latitudes, up to 1 PgC month-1 during winter when baroclinic wave activity peaks. During boreal winter when northern plants respire, warm moist air, high in CO2, is swept upward and poleward along the east side of baroclinic waves and injected into the polar vortex, while cold dry air, low in CO 2, that had been transported into the polar vortex earlier in the year is advected equatorward. These synoptic eddies act to strongly reduce seasonality of CO2 in the biologically active mid-latitudes by 50% of that implied by local net ecosystem exchange while correspondingly amplifying seasonality in the Arctic. Transport along stormtracks is correlated with rising, moist, cloudy air, which systematically hides this CO2 transport from satellite observing systems. Meridional fluxes of CO2 are of comparable magnitude as surface exchange of CO2 in mid-latitudes, and

  2. Carbon-Ion Radiation Therapy for Pelvic Recurrence of Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Shigeru, E-mail: s_yamada@nirs.go.jp [Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Kamada, Tadashi [Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Ebner, Daniel K. [Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Brown University Alpert Medical School, Providence, Rhode Island (United States); Shinoto, Makoto [Ion Beam Therapy Center, SAGA HIMAT Foundation, Saga (Japan); Terashima, Kotaro [Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Isozaki, Yuka; Yasuda, Shigeo; Makishima, Hirokazu; Tsuji, Hiroshi; Tsujii, Hirohiko [Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Isozaki, Tetsuro; Endo, Satoshi [Graduate School of Medicine, Chiba University, Chiba (Japan); Takahashi, Keiichi [Tokyo Metropolitan Cancer and Infectious Disease Center, Komagome, Tokyo (Japan); Sekimoto, Mitsugu [National Hospital Organization Osaka National Hospital, Osaka (Japan); Saito, Norio [National Cancer Center Hospital East, Kashiwa, Chiba (Japan); Matsubara, Hisahiro [Graduate School of Medicine, Chiba University, Chiba (Japan)

    2016-09-01

    Purpose: Investigation of the treatment potential of carbon-ion radiation therapy in pelvic recurrence of rectal cancer. Methods and Materials: A phase 1/2 dose escalation study was performed. One hundred eighty patients (186 lesions) with locally recurrent rectal cancer were treated with carbon-ion radiation therapy (CIRT) (phase 1/2: 37 and 143 patients, respectively). The relapse locations were 71 in the presacral region, 82 in the pelvic sidewalls, 28 in the perineum, and 5 near the colorectal anastomosis. A 16-fraction in 4 weeks dose regimen was used, with total dose ranging from 67.2 to 73.6 Gy(RBE); RBE-weighted absorbed dose: 4.2 to 4.6 Gy(RBE)/fraction. Results: During phase 1, the highest total dose, 73.6 Gy(RBE), resulted in no grade >3 acute reactions in the 13 patients treated at that dose. Dose escalation was halted at this level, and this dose was used for phase 2, with no other grade >3 acute reactions observed. At 5 years, the local control and survival rates at 73.6 Gy(RBE) were 88% (95% confidence interval [CI], 80%-93%) and 59% (95% CI, 50%-68%), respectively. Conclusion: Carbon-ion radiation therapy may be a safe and effective treatment option for locally recurrent rectal cancer and may serve as an alternative to surgery.

  3. Improvement on corrosion resistance of NiTi orthopedic materials by carbon plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Poon, Ray W.Y.; Ho, Joan P.Y.; Luk, Camille M.Y.; Liu Xuanyong; Chung, Jonathan C.Y.; Chu, Paul K.; Yeung, Kelvin W.K.; Lu, William W.; Cheung, Kenneth M.C.

    2006-01-01

    Nickel-titanium shape memory alloys (NiTi) have potential applications as orthopedic implants because of their unique super-elastic properties and shape memory effects. However, the problem of out-diffusion of harmful Ni ions from the alloys during prolonged use inside a human body must be overcome before they can be widely used in orthopedic implants. In this work, we enhance the corrosion resistance of NiTi using carbon plasma immersion ion implantation and deposition (PIII and D). Our corrosion and simulated body fluid tests indicate that either an ion-mixed amorphous carbon coating fabricated by PIII and D or direct carbon PIII can drastically improve the corrosion resistance and block the out-diffusion of Ni from the materials. Results of atomic force microscopy (AFM) indicate that both C 2 H 2 -PIII and D and C 2 H 2 -PIII do not roughen the original flat surface to an extent that can lead to degradation in corrosion resistance

  4. Fate of D3 mouse embryonic stem cells exposed to X-rays or carbon ions.

    Science.gov (United States)

    Luft, S; Pignalosa, D; Nasonova, E; Arrizabalaga, O; Helm, A; Durante, M; Ritter, S

    2014-01-15

    The risk of radiation exposure during embryonic development is still a major problem in radiotoxicology. In this study we investigated the response of the murine embryonic stem cell (mESC) line D3 to two radiation qualities: sparsely ionizing X-rays and densely ionizing carbon ions. We analyzed clonogenic cell survival, proliferation, induction of chromosome aberrations as well as the capability of cells to differentiate to beating cardiomyocytes up to 3 days after exposure. Our results show that, for all endpoints investigated, carbon ions are more effective than X-rays at the same radiation dose. Additionally, in long term studies (≥8 days post-irradiation) chromosomal damage and the pluripotency state were investigated. These studies reveal that pluripotency markers are present in the progeny of cells surviving the exposure to both radiation types. However, only in the progeny of X-ray exposed cells the aberration frequency was comparable to that of the control population, while the progeny of carbon ion irradiated cells harbored significantly more aberrations than the control, generally translocations. We conclude that cells surviving the radiation exposure maintain pluripotency but may carry stable chromosomal rearrangements after densely ionizing radiation. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Recent Progress in Design of Biomass-Derived Hard Carbons for Sodium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Joanna Górka

    2016-12-01

    Full Text Available Sodium ion batteries (SIBs have attracted lots of attention over last few years due to the abundance and wide availability of sodium resources, making SIBs the most cost-effective alternative to the currently used lithium ion batteries (LIBs. Many efforts are underway to find effective anodes for SIBs since the commercial anode for LIBs, graphite, has shown very limited capacity for SIBs. Among many different types of carbons, hard carbons—especially these derived from biomass—hold a great deal of promise for SIB technology thanks to their constantly improving performance and low cost. The main scope of this mini-review is to present current progress in preparation of negative electrodes from biomass including aspects related to precursor types used and their impact on the final carbon characteristics (structure, texture and composition. Another aspect discussed is how certain macro- and microstructure characteristics of the materials translate to their performance as anode for Na-ion batteries. In the last part, current understanding of factors governing sodium insertion into hard carbons is summarized, specifically those that could help solve existing performance bottlenecks such as irreversible capacity, initial low Coulombic efficiency and poor rate performance.

  6. CONSIDERATIONS REGARDING THE INFLUENCE OF METALIC IONS OF THE STABILITY OF CARBONATES FROM SOILS

    Directory of Open Access Journals (Sweden)

    D. Bulgariu

    2005-10-01

    Full Text Available The distribution of minor elements in heterogeneous mineral / aqueous solutions systems represent one of important problem, with many applications in environmental geochemistry field. Ours studies was focus on the metal ions distribution in carbonate (CaCO3 / solution systems, from applicability point of view to the estimation of formation conditions and of carbonates stability from soils. On the base of our results obtained by sequential solid / liquid extraction for 17 soil samples and theoretical modeling of CaCO3 / solution systems, and the results from literature we try to develop the McIntire prognosis models and the free Gibbs enthalpy linear correlation model, by the inclusion in calculus relations of distribution coefficients a higher number of factors which effective influenced the thermodynamics and kinetics of interphase distribution processes of metal ions. The established correlations has been used to the estimation of time evolution of carbonate / solution equilibrium under the influence of some metal ions (Cd, Zn, Cu, Pb, Bi, which appear usual as pollutants in soils. The prognosis realized on the base of the established correlations are in agreement with the theoretical modelling results and studies of case for different types of polluted soils with heavy metals.

  7. Carbonate ion-enriched hot spring water promotes skin wound healing in nude rats.

    Directory of Open Access Journals (Sweden)

    Jingyan Liang

    Full Text Available Hot spring or hot spa bathing (Onsen is a traditional therapy for the treatment of certain ailments. There is a common belief that hot spring bathing has therapeutic effects for wound healing, yet the underlying molecular mechanisms remain unclear. To examine this hypothesis, we investigated the effects of Nagano hot spring water (rich in carbonate ion, 42°C on the healing process of the skin using a nude rat skin wound model. We found that hot spring bathing led to an enhanced healing speed compared to both the unbathed and hot-water (42°C control groups. Histologically, the hot spring water group showed increased vessel density and reduced inflammatory cells in the granulation tissue of the wound area. Real-time RT-PCR analysis along with zymography revealed that the wound area of the hot spring water group exhibited a higher expression of matrix metalloproteinases-2 and -9 compared to the two other control groups. Furthermore, we found that the enhanced wound healing process induced by the carbonate ion-enriched hot spring water was mediated by thermal insulation and moisture maintenance. Our results provide the evidence that carbonate ion-enriched hot spring water is beneficial for the treatment of skin wounds.

  8. Mutagenic effects of carbon ion beam irradiations on dry Lotus japonicus seeds

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Shanwei [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhou, Libin, E-mail: libinzhou@impcas.ac.cn [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Li, Wenjian; Du, Yan [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Yu, Lixia; Feng, Hui; Mu, Jinhu [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Yuze [College of Life Science and Technology, Gansu Agricultural University, No. 1 Yingmen Village, Anning District, Lanzhou, Gansu Province 730070 (China)

    2016-09-15

    Carbon ion beam irradiation is a powerful method for creating mutants and has been used in crop breeding more and more. To investigate the effects of carbon ion beams on Lotus japonicus, dry seeds were irradiated by 80 MeV/u carbon ion beam at dosages of 0, 100, 200, 300, 400, 500 and 600 Gy. The germination rate, survival rate and root length of M{sub 1} populations were explored and the dose of 400 Gy was selected as the median lethal dose (LD{sub 50}) for a large-scale mutant screening. Among 2472 M{sub 2} plants, 127 morphological mutants including leaf, stem, flower and fruit phenotypic variation were found, and the mutation frequency was approximately 5.14%. Inter simple sequence repeat (ISSR) assays were utilized to investigate the DNA polymorphism between seven mutants and eight plants without phenotypic variation from M{sub 2} populations. No remarkable differences were detected between these two groups, and the total polymorphic rate was 0.567%.

  9. Intra-operative radiation therapy with laser-accelerated carbon ions

    Science.gov (United States)

    Mur, P.; Bellido, P.; Seimetz, M.; Lera, R.; Ruiz-de la Cruz, A.; Galán, M.; Roso, L.; Sánchez, F.; Benlloch, J. M.

    2017-03-01

    Laser accelerators have long been proposed as beam source for hadron therapy. However, the high energies necessary for the treatment of deep-lying tumours, combined with stringent requirements on the beam quality, are still a severe challenge. In the present work, we discuss the applicability of laser-accelerated carbon ions at moderate energies (100-480 MeV) to the irradiation of superficial lesions. We propose a new therapeutic modality which combines the versatility of Intra-Operative Radiation Therapy with the advantages of carbon ions as compared to photon and electron radiation. To justify this idea a feasibility study has been carried out, focused on the uniformity of dose deposition inside the treatment volume. Physical and biological aspects characteristic to laser-accelerated carbon ion beams are considered. A GATE simulation has been performed, showing an approximately uniform depth-dose profile up to a maximum penetration depth of 5 mm for a single radiation boost of 10 GyE.

  10. Effect of swift heavy ion irradiation on single- and multiwalled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Olejniczak, Andrzej, E-mail: aolejnic@chem.uni.torun.pl [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Faculty of Chemistry, Nicolaus Copernicus University, ul. Gagarina 7, 87-100 Toruń (Poland); Skuratov, Vladimir A. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation)

    2014-05-01

    The effect of irradiation with swift heavy ions on the structure and properties of carbon nanotubes was investigated by Raman spectroscopy. It was found that disordering of the system occurred mainly at the surface. No ordering phenomena have been observed over a whole range of both fluences and electronic stopping powers studied. The disorder parameter (i.e., the ratio of the D and G band intensities (I{sub D}/I{sub G})) increases non-linearly with the irradiation dose, showing a tendency to saturate at high fluences. The increase in the disorder parameter upon irradiation was proportional to the square root of the ion fluence. The radiation stability of the few-walled nanotubes was ca. 1.6 higher than that of the single-walled ones. The irradiation with both the Xe and Kr ions leads to essentially the same increase in the I{sub D}/I{sub G} ratio with respect to the deposited electronic energy density. In the case of the Ar ion irradiation, the observed increase in the I{sub D}/I{sub G} ratio is much lower, suggesting that the electronic stopping power threshold for defects creation in carbon nanotubes is lower than that for graphite.

  11. Development of the removal technology for toxic heavy metal ions by surface-modified activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Park, Geun Il; Song, Kee Chan; Kim, Kwang Wook; Kim, In Tae; Cho, Il Hoon; Kim, Joon Hyung

    2001-01-01

    Adsorption capacities of both radionuclides(uranium, cobalt) and toxic heavy metals (lead, cadmium and chromium) using double surface-modified activated carbon in wide pH ranges are extensively evaluated. Surface-modified activated carbons are classified as AC(as-received carbon), OAC(single surface-modified carbon with nitric acid solution) and OAC-Na(double surface-modified carbon with various alkali solutions). It is established that optimal condition for the second surface modification of OAC is to use the mixed solution of both NaOH and NaCl with total concentration of 0.1 N based on adsorption efficiencies of uranium and cobalt. Variations of adsorption efficiencies in pH ranges of 2{approx}10 and the adsorption capacities in batch adsorber and fixed bed for removal of both radionuclides and toxic heavy metals using OAC-Na were shown to be superior to that of the AC and OAC even in a low pH range. Capacity factors of OAC-Na for the removal of various metal ions are also excellent to that of AC or OAC. Quantitative analysis of capacity factors for each ions showed that adsorption capacity of OAC-Na increased by 30 times for uranium, 60 times for cobalt, 9 times for lead, 30 times for cadmium, 3 times for chromium compared to that of AC at pH 5, respectively. Adsorption capacity of OAC-Na is comparable to that of XAD-16-TAR used as commercial ion exchange resin.

  12. Radiation biophysical studies with mammalian cells and a modulated carbon ion beam

    International Nuclear Information System (INIS)

    Chapman, J.D.; Blakely, E.A.; Smith, K.C.; Urtasun, R.C.; Lyman, J.T.; Tobias, C.A.

    1978-01-01

    Chinese hamster (V-79) and human kidney (T-1) cells were irradiated in stirred suspensions placed at various positions in the plateau and extended Bragg peak of a 400-MeV/amu carbon ion beam. The range of the ions was modulated by a lead (translational) ridge filter and a brass (spiral) ridge filter designed to produce extended peaks of approximately 4 and 10 cm, respectively. Stationary-phase and G 1 -phase populations of Chinese hamster cells were found to have different absolute radiosensitivities which, in turn, were different from that of asynchronous human kidney cells. The increase in relative biological effectiveness (RBE) observed as carbon ions were slowed down and stopped in water was similar for the three cell populations at doses greater than 400 rad. At lower doses the RBE was greater for the hamster cell populations than for the human kidney cells. The gain in RBE (at the 50% survival level) between the plateaus and the middle region of the extended peaks was approximately 2.0 and 1.7 for the 4- and 10-cm extended peaks, respectively. Oxygen enhancement ratios (OER) were determined at the 10% survival levels with stationary-phase populations of hamster cells. Values of 2.8, 2.65, and 1.65 were obtained for the OER of 220-kV x rays, plateau carbon, and the middle region of the 4-cm carbon peak, respectively. Across the 10-cm carbon peak the OER was found to vary between values of 2.4 to 1.55 from the proximal to distal positions

  13. Adsorption of Cu2+ Ions From Aqueous Solutions Using Oxidized Multi-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Soheil Sobhanardakani

    2015-06-01

    Full Text Available Copper ion (Cu2+ is one of the heavy metal ions that cause environmental pollution specifically in water. Copper ion cations are not biodegradable and tend to cumulate in living organisms. Consequently, the removal of Cu2+ in environmental samples plays an important role in environmental pollution monitoring. The purpose of the present work was to prepare oxidized Multi-Walled Carbon Nano Tubes (MWCNTs for removal of Cu2+ ions from aqueous solutions. This study was conducted under laboratory conditions. Multi-Walled Carbon Nano Tubes were oxidized and characterized by Fourier Transform Infrared Spectroscopy (FTIR, Scanning Electron Microscope (SEM and the Brunauer, Emmett, and Teller (BET methods. The effects of various factors, such as solution pH (3 - 9, adsorbent dose (0.006 - 0.06 g and contact time (10 - 120 minutes were investigated. Results showed that the suitable pH for Cu2+ ions removal was about 6.0, and the optimal dose was 0.03 g. Isotherm studies indicated that the Langmuir model fits the experimental data better than the Freundlich model. Maximum Cu2+ adsorption capacity was calculated as 200 mg g-1. The kinetics of the adsorption process was tested for the pseudo-first-order and pseudo-second-order models. The comparison among the models showed that the pseudo-second order model best described the adsorption kinetics. The results showed that oxidized MWCNTs can be used as a low cost adsorbent for the removal of Cu2+ ions from aqueous solutions.

  14. Mechanical and tribological properties of carbon thin film with tungsten interlayer prepared by Ion beam assisted deposition

    Czech Academy of Sciences Publication Activity Database

    Vlčák, P.; Černý, F.; Tolde, Z.; Sepitka, J.; Gregora, Ivan; Daniš, S.

    2013-01-01

    Roč. 2013, FEB (2013) ISSN 2314-4874 Institutional support: RVO:68378271 Keywords : carbon coatings * ion beam deposition * XRD * nanoindentation Subject RIV: BM - Solid Matter Physics ; Magnetism http://dx.doi.org/10.1155/2013/630156

  15. Optical, structural, and chemical properties of CR-39 implanted with 5.2 MeV doubly charged carbon ions

    Science.gov (United States)

    Ali, Dilawar; Butt, M. Z.; Ishtiaq, Mohsin; Waqas Khaliq, M.; Bashir, Farooq

    2016-11-01

    Poly-allyl-diglycol-carbonate (CR-39) specimens were irradiated with 5.2 MeV doubly charged carbon ions using Pelletron accelerator. Ion dose was varied from 5 × 1013 to 5 × 1015 ions cm-2. Optical, structural, and chemical properties were investigated by UV-vis spectroscopy, x-ray diffractometer, and FTIR/Raman spectroscopy, respectively. It was found that optical absorption increases with increasing ion dose. Absorption edge shifts from UV region to visible region. The measured opacity values of pristine and ion implanted CR-39 range from 0.0519 to 4.7959 mm-1 following an exponential growth (9141%) with the increase in ion dose. The values of direct and indirect band gap energy decrease exponentially with an increase in ion dose by 59% and 71%, respectively. However, average refractive index in the visible region increases from 1.443 to 2.864 with an increase in ion dose, by 98%. A linear relation between band gap energy and crystallite size was observed. Both the number of carbon atoms in conjugation length and the number of carbon atoms per cluster increase linearly with the increase in ion dose. FTIR spectra showed that on C+2 ions irradiation, the intensity of all bands decreases gradually without appearance of any new band, indicating degradation of polymer after irradiation. Raman spectra revealed that the density of -CH2- group decreases on C+2 ions irradiation. However, the structure of CR-39 is completely destroyed on irradiation with ion dose 1 × 1015 and 5 × 1015 ions cm-2.

  16. Factors Affecting the Adsorption of Trivalent Chromium Ions by Activated Carbon Prepared from Waste Rubber Tyres

    Directory of Open Access Journals (Sweden)

    Sylvia E. Benjamin

    2017-08-01

    Full Text Available Economic gains are generally the outcome of industrialization and consequently urbanization. However, positive fiscal index generates a negative impact on natural environment sources heaving pollutant burden on soil, air and water. Industries throw tones of contaminated water into soil and water bodies without proper treatment and create a potential threat for both living and non-living species. Chromium in trivalent state (Cr3+ is added in water bodies and soil through waste water from tanneries, cooling water systems, chemical and pulp and paper industries. The present research work aims at the preparation of an inexpensive activated carbon prepared from non- degradable waste scrap rubber tyres. The carbon produced from scrap rubber tyres was activated by 5% solution of BaCl2 and 0.4 N solution of HCl and verified by ethylene blue solution. The adsorption capacity of the Tyre activated carbon (TAC was investigated for different parameters i.e., initial chromium (III ion concentration, activated carbon dosage, contact/ stirring time and pH. The adsorption capacity of TAC depends on the initial metal ion concentration and the TAC dose. pH of the chromium solution effects the adsorption capacity of TAC due to the formation of tetra hydroxochromate(III complexes,. The results show that TAC offers a cost effective reclamation process for the removal of Cr3+ from effluent waters.

  17. Resistance of blended concrete containing an industrial petrochemical residue to chloride ion penetration and carbonation

    Directory of Open Access Journals (Sweden)

    Nancy Torres Castellanos

    2014-01-01

    Full Text Available In this study, the resistance of blended concrete containing catalytic cracking residue (FCC to chloride ion penetration and carbonation was examined. FCC was added at the levels of 10%, 20%, and 30% as partial replacement for cement. Concretes with 10% of silica fume (SF, 10% of metakaolin (MK, and without additives were evaluated as reference materials. The rapid chloride permeability test (RCPT performed according to ASTM C1202 standards and an accelerated carbonation test in a climatic chamber under controlled conditions (23 °C, 60% RH and 4.0% CO2, were used in order to evaluate the performance of these concretes. Additionally, their compressive strength was determined. The results indicate that binary blends with 10% FCC had similar compressive strength to concrete without additives and had lower chloride permeability. 10% SF and 10% MK exhibited better mechanical behavior and a significant decrease in chloride penetration when compared to 10% FCC. It is noted that there was an increase in concrete carbonation when FCC or MK were used as additives. It was also observed that with longer curing time, the samples with and without additives, presented higher resistance to carbonation. The accelerated corrosion test by impressed voltage was also performed to verify the findings and to investigate the characteristics of corrosion using a 3.5% NaCl solution as electrolyte. The mixtures that contained 10% FCC were highly resistant to chloride ion penetration and did not present cracking within the testing period.

  18. Sponge-like reduced graphene oxide/silicon/carbon nanotube composites for lithium ion batteries

    Science.gov (United States)

    Fang, Menglu; Wang, Zhao; Chen, Xiaojun; Guan, Shiyou

    2018-04-01

    Three-dimensional sponge-like reduced graphene oxide/silicon/carbon nanotube composites were synthesized by one-step hydrothermal self-assembly using silicon nanoparticles, graphene oxide and amino modified carbon nanotubes to develop high-performance anode materials of lithium ion batteries. Scanning electron microscopy and transmission electron microscopy images show the structure of composites that Silicon nanoparticles are coated with reduced graphene oxide while amino modified carbon nanotubes wrap around the reduced graphene oxide in the composites. When applied to lithium ion battery, these composites exhibit high initial specific capacity of 2552 mA h/g at a current density of 0.05 A/g. In addition, reduced graphene oxide/silicon/carbon nanotube composites also have better cycle stability than bare Silicon nanoparticles electrode with the specific capacity of 1215 mA h/g after 100 cycles. The three-dimension sponge-like structure not only ensures the electrical conductivity but also buffers the huge volume change, which has broad potential application in the field of battery.

  19. Molecular characterization of organic matter mobilized from Bangladeshi aquifer sediment: tracking carbon compositional change during microbial utilization

    Directory of Open Access Journals (Sweden)

    L. E. Pracht

    2018-03-01

    Full Text Available Bioavailable organic carbon in aquifer recharge waters and sediments can fuel microbial reactions with implications for groundwater quality. A previous incubation experiment showed that sedimentary organic carbon (SOC mobilized off sandy sediment collected from an arsenic-contaminated and methanogenic aquifer in Bangladesh was bioavailable; it was transformed into methane. We used high-resolution mass spectrometry to molecularly characterize this mobilized SOC, reference its composition against dissolved organic carbon (DOC in surface recharge water, track compositional changes during incubation, and advance understanding of microbial processing of organic carbon in anaerobic environments. Organic carbon mobilized off aquifer sediment was more diverse, proportionately larger, more aromatic, and more oxidized than DOC in surface recharge. Mobilized SOC was predominately composed of terrestrially derived organic matter and had characteristics signifying that it evaded microbial processing within the aquifer. Approximately 50 % of identified compounds in mobilized SOC and in DOC from surface recharge water contained sulfur. During incubation, after mobilized SOC was converted into methane, new organosulfur compounds with high S-to-C ratios and a high nominal oxidation state of carbon (NOSC were detected. We reason that these detected compounds formed abiotically following microbial reduction of sulfate to sulfide, which could have occurred during incubation but was not directly measured or that they were microbially synthesized. Most notably, microbes transformed all carbon types during incubation, including those currently considered thermodynamically unviable for microbes to degrade in anaerobic conditions (i.e., those with a low NOSC. In anaerobic environments, energy yields from redox reactions are small and the amount of energy required to remove electrons from highly reduced carbon substrates during oxidation decreases the thermodynamic

  20. Molecular characterization of organic matter mobilized from Bangladeshi aquifer sediment: tracking carbon compositional change during microbial utilization

    Science.gov (United States)

    Pracht, Lara E.; Tfaily, Malak M.; Ardissono, Robert J.; Neumann, Rebecca B.

    2018-03-01

    Bioavailable organic carbon in aquifer recharge waters and sediments can fuel microbial reactions with implications for groundwater quality. A previous incubation experiment showed that sedimentary organic carbon (SOC) mobilized off sandy sediment collected from an arsenic-contaminated and methanogenic aquifer in Bangladesh was bioavailable; it was transformed into methane. We used high-resolution mass spectrometry to molecularly characterize this mobilized SOC, reference its composition against dissolved organic carbon (DOC) in surface recharge water, track compositional changes during incubation, and advance understanding of microbial processing of organic carbon in anaerobic environments. Organic carbon mobilized off aquifer sediment was more diverse, proportionately larger, more aromatic, and more oxidized than DOC in surface recharge. Mobilized SOC was predominately composed of terrestrially derived organic matter and had characteristics signifying that it evaded microbial processing within the aquifer. Approximately 50 % of identified compounds in mobilized SOC and in DOC from surface recharge water contained sulfur. During incubation, after mobilized SOC was converted into methane, new organosulfur compounds with high S-to-C ratios and a high nominal oxidation state of carbon (NOSC) were detected. We reason that these detected compounds formed abiotically following microbial reduction of sulfate to sulfide, which could have occurred during incubation but was not directly measured or that they were microbially synthesized. Most notably, microbes transformed all carbon types during incubation, including those currently considered thermodynamically unviable for microbes to degrade in anaerobic conditions (i.e., those with a low NOSC). In anaerobic environments, energy yields from redox reactions are small and the amount of energy required to remove electrons from highly reduced carbon substrates during oxidation decreases the thermodynamic favorability of

  1. A novel method for observation by unaided eyes of nitrogen ion tracks and angular distribution in a plasma focus device using 50 Hz–HV electrochemically-etched polycarbonate detectors

    International Nuclear Information System (INIS)

    Sohrabi, M.; Habibi, M.; Roshani, G.H.; Ramezani, V.

    2012-01-01

    A novel ion detection method has been developed and studied in this paper for the first time to detect and observe tracks of nitrogen ions and their angular distribution by unaided eyes in the Amirkabir 4 kJ plasma focus device (PFD). The method is based on electrochemical etching (ECE) of nitrogen ion tracks in 1 mm thick large area polycarbonate (PC) detectors. The ECE method employed a specially designed and constructed large area ECE chamber by applying a 50 Hz–high voltage (HV) generator under optimized ECE conditions. The nitrogen ion tracks and angular distribution were efficiently (constructed for this study) amplified to a point observable by the unaided eyes. The beam profile and angular distribution of nitrogen ion tracks in the central axes of the beam and two- and three-dimensional iso-ion track density distributions showing micro-beam spots were determined. The distribution of ion track density along the central axes versus angular position shows double humps around a dip at the 0° angular positions. The method introduced in this paper proved to be quite efficient for ion beam profile and characteristic studies in PFDs with potential for ion detection studies and other relevant dosimetry applications.

  2. Health-related quality of life after carbon-ion radiotherapy for prostate cancer. A 3-year prospective study

    International Nuclear Information System (INIS)

    Katoh, Hiroyuki; Tsuji, Hiroshi; Ishikawa, Hitoshi

    2014-01-01

    To assess 3-year health-related quality of life of patients treated with carbon ion radiotherapy for prostate cancer. A total of 213 patients received carbon-ion radiotherapy at a total dose of 66 Gy equivalent in 20 fractions over 5 weeks, and neoadjuvant and adjuvant androgen deprivation therapy were administered for high-risk patients for at least 12 months. A health-related quality of life assessment was carried out at four time-points (immediately before the initiation of carbon-ion radiotherapy, immediately after, 12 and 36 months after completion of carbon-ion radiotherapy) using Functional Assessment of Cancer Therapy General and for Prostate Cancer Patients. The evaluable response rates among all responses were more than 94%. Overall, a significant decrease in the scores of the health-related quality of life 12 months after carbon-ion radiotherapy returned to their baseline levels at 36 months. Additionally, no significant decrease was observed in the scores at any of the assessment time-points compared with their baseline scores in the group of carbon-ion radiotherapy without androgen deprivation therapy; however, the presence of morbidity and biochemical failure significantly worsened the scores, and the decreases in the scores did not improve even at 36 months after carbon-ion radiotherapy. An assessment based on a subjective scoring system shows a significant decrease in health-related quality of life at 12 months after carbon-ion radiation therapy, which tends to return to baseline levels at 36 months. The presence of morbidity and bio-chemical failure significantly worsen health-related quality of life scores. Further controlled studies focusing on health-related quality of life assessment in patients with prostate cancer are warranted. (author)

  3. Synthesis of silicon–carbon black composite as anode material for lithium ion battery

    Science.gov (United States)

    Kim, Hanvin; Yun, Yongsub; Lee, Young-Chan; Lee, Myeong-Hoon; Saito, Nagahiro; Kang, Jun

    2018-01-01

    Silicon has been attracting attention as an anode material that can be used for the design of high-capacity lithium ion batteries (LIB). However, the long-term cycling performance of silicon is limited owing to exfoliation from the current collector, resulting from volumetric expansion upon alloying with lithium in the charging process. However, carbon black is an agglomerate of primary particles that form a network and can incorporate a sufficient void space between network structures to accommodate the volumetric expansion of silicon. In this study, we propose the possibility of preventing the volume expansion and exfoliation of silicon by capturing silicon nanoparticles in the void space of the carbon black network. A silicon–carbon black composite material with this structure was successfully synthesized by solution plasma processing.

  4. Dodecahedron-Shaped Porous Vanadium Oxide and Carbon Composite for High-Rate Lithium Ion Batteries.

    Science.gov (United States)

    Zhang, Yifang; Pan, Anqiang; Wang, Yaping; Wei, Weifeng; Su, Yanhui; Hu, Jimei; Cao, Guozhong; Liang, Shuquan

    2016-07-13

    Carbon-based nanocomposites have been extensively studied in energy storage and conversion systems because of their superior electrochemical performance. However, the majority of metal oxides are grown on the surface of carbonaceous material. Herein, we report a different strategy of constructing V2O5 within the metal organic framework derived carbonaceous dodecahedrons. Vanadium precursor is absorbed into the porous dodecahedron-shaped carbon framework first and then in situ converted into V2O5 within the carbonaceous framework in the annealing process in air. As cathode materials for lithium ion batteries, the porous V2O5@C composites exhibit enhanced electrochemical performance, due to the synergistic effect of V2O5 and carbon composite.

  5. A Combustion Chemistry Analysis of Carbonate Solvents in Li-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Harris, S J; Timmons, A; Pitz, W J

    2008-11-13

    Under abusive conditions Li-ion batteries can rupture, ejecting electrolyte and other flammable gases. In this paper we consider some of the thermochemical properties of these gases that will determine whether they ignite and how energetically they burn. We show that flames of carbonate solvents are fundamentally less energetic than those of conventional hydrocarbons. An example of this difference is given using a recently developed mechanism for dimethyl carbonate (DMC) combustion, where we show that a diffusion flame burning DMC has only half the peak energy release rate of an analogous propane flame. We find a significant variation among the carbonate solvents in the factors that are important to determining flammability, such as combustion enthalpy and vaporization enthalpy. This result suggests that thermochemical and kinetic factors might well be considered when choosing solvent mixtures.

  6. Adsorption of pertechnetate ion on various active carbons from mineral acid solutions

    International Nuclear Information System (INIS)

    Ito, K.

    1991-01-01

    The adsorption behavior of pertechnetate ion (TcO 4 - ) on active carbon has been studied for various acid solutions, taking as indicative value the distribution coefficient K d of Tc between active carbon surface and solution. In a system where the total anion concentration of the acid and its sodium salt was maintained constant, modifying the pH of the solution proved distinctly to influence the Tc adsorption behavior of active carbon: taking the case of active carbon derived from coconut shell, increasing the acidity raised K d ; around neutrality there occurred a level stage; in the alkali region, K d declined. The rise of K d in the acid region, however, was observed only with active carbon derived from coconut shell, from oil pitch or from saw dust; it failed to occur when the active carbon was derived from coal or from bone. With a hydrochloric acid system, the rise of K d started around 1 M (mol dm -1 ) HCl. Beyond 3 M, on the other hand, a breakthrough occurred, and K d declined with increasing acidity. With a nitric acid system, K d rose from 1 M, and the breakthrough occurred at 2 M. When the adsorption was left to equilibrate beyond 4 h, desorption displacement of TcO 4 - by a coexisting other anion was observed in the case of perchloric acid solutions of concentration above 0.1 M and with sulfuric acid solutions above 0.5 M. (author)

  7. Synthesis carbon foams prepared from gelatin (CFG) for cadmium ion adsorption

    Science.gov (United States)

    Ulfa, M.; Ulfa, D. K.

    2018-01-01

    In this paper, carbon foam from gelatin (CFG) was synthesized by acid-catalyzed carbonization of gelatin solution on mild condition by the simple method. Gelatin (Ge) were used as sacrificial template and source of carbon. Sulphuric acid was used as acid catalyst. Carbon foam CFG sample were characterized by scanning electron microscope (SEM), nitrogen adsorption desorption and FTIR for knowing textural and structural properties of the sample. Carbon foam CFG sample demonstrated macro pipes-channel like with pore size that varies between 30-40 μ and surface area m 60-100 m2g-1. The carbon foams CFG sample were tested by using adsorption process for obtained their performance for decreasing Cd(II) ions from aqueous solutions. The adsorption capacities for cadmium was 46.7 mg/g obtained by using adsorbent dose 50 mg, initial concentration 50 ppm, contact time, 3 h; room temperature, stirring rate 150 rpm) which reached equilibrium at 55 min. Adsorption process fits using using Lagergren and Ho and McKay equation and measuring data

  8. Microdosimetry for a carbon ion beam using track-etched detectors

    Czech Academy of Sciences Publication Activity Database

    Ambrožová, Iva; Vondráček, V.; Šefl, M.; Štěpán, Václav; Pachnerová Brabcová, Kateřina; Ploc, Ondřej; Incerti, S.; Davídková, Marie

    2015-01-01

    Roč. 166, 1-4 (2015), s. 247-252 ISSN 0144-8420 R&D Projects: GA MŠk LD12008; GA MŠk(CZ) LG13031 Grant - others:GA MŠk(CZ) LM2010005 Institutional support: RVO:61389005 Keywords : linear energy transfer * spectra * HIMAC * SOBP Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.894, year: 2015

  9. Dosimetric verification in water of a Monte Carlo treatment planning tool for proton, helium, carbon and oxygen ion beams at the Heidelberg Ion Beam Therapy Center

    Science.gov (United States)

    Tessonnier, T.; Böhlen, T. T.; Ceruti, F.; Ferrari, A.; Sala, P.; Brons, S.; Haberer, T.; Debus, J.; Parodi, K.; Mairani, A.

    2017-08-01

    The introduction of ‘new’ ion species in particle therapy needs to be supported by a thorough assessment of their dosimetric properties and by treatment planning comparisons with clinically used proton and carbon ion beams. In addition to the latter two ions, helium and oxygen ion beams are foreseen at the Heidelberg Ion Beam Therapy Center (HIT) as potential assets for improving clinical outcomes in the near future. We present in this study a dosimetric validation of a FLUKA-based Monte Carlo treatment planning tool (MCTP) for protons, helium, carbon and oxygen ions for spread-out Bragg peaks in water. The comparisons between the ions show the dosimetric advantages of helium and heavier ion beams in terms of their distal and lateral fall-offs with respect to protons, reducing the lateral size of the region receiving 50% of the planned dose up to 12 mm. However, carbon and oxygen ions showed significant doses beyond the target due to the higher fragmentation tail compared to lighter ions (p and He), up to 25%. The Monte Carlo predictions were found to be in excellent geometrical agreement with the measurements, with deviations below 1 mm for all parameters investigated such as target and lateral size as well as distal fall-offs. Measured and simulated absolute dose values agreed within about 2.5% on the overall dose distributions. The MCTP tool, which supports the usage of multiple state-of-the-art relative biological effectiveness models, will provide a solid engine for treatment planning comparisons at HIT.

  10. Dosimetric verification in water of a Monte Carlo treatment planning tool for proton, helium, carbon and oxygen ion beams at the Heidelberg Ion Beam Therapy Center.

    Science.gov (United States)

    Tessonnier, T; Böhlen, T T; Ceruti, F; Ferrari, A; Sala, P; Brons, S; Haberer, T; Debus, J; Parodi, K; Mairani, A

    2017-07-31

    The introduction of 'new' ion species in particle therapy needs to be supported by a thorough assessment of their dosimetric properties and by treatment planning comparisons with clinically used proton and carbon ion beams. In addition to the latter two ions, helium and oxygen ion beams are foreseen at the Heidelberg Ion Beam Therapy Center (HIT) as potential assets for improving clinical outcomes in the near future. We present in this study a dosimetric validation of a FLUKA-based Monte Carlo treatment planning tool (MCTP) for protons, helium, carbon and oxygen ions for spread-out Bragg peaks in water. The comparisons between the ions show the dosimetric advantages of helium and heavier ion beams in terms of their distal and lateral fall-offs with respect to protons, reducing the lateral size of the region receiving 50% of the planned dose up to 12 mm. However, carbon and oxygen ions showed significant doses beyond the target due to the higher fragmentation tail compared to lighter ions (p and He), up to 25%. The Monte Carlo predictions were found to be in excellent geometrical agreement with the measurements, with deviations below 1 mm for all parameters investigated such as target and lateral size as well as distal fall-offs. Measured and simulated absolute dose values agreed within about 2.5% on the overall dose distributions. The MCTP tool, which supports the usage of multiple state-of-the-art relative biological effectiveness models, will provide a solid engine for treatment planning comparisons at HIT.

  11. Immobilization of extracellular matrix on polymeric materials by carbon-negative-ion implantation

    Science.gov (United States)

    Tsuji, Hiroshi; Sommani, Piyanuch; Muto, Takashi; Utagawa, Yoshiyuki; Sakai, Shun; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo

    2005-08-01

    Effects of ion implantation into polystyrene (PS), silicone rubber (SR) and poly-L-lactic acid (PLA) have been investigated for immobilization of extracellular matrix. Carbon negative ions were implanted into PS and SR sheets at various energies between 5-30 keV and various doses between 1.0 × 1014-1.0 × 1016 ions/cm2. Contact angles of pure water on C-implanted surfaces of PS and SR were decreased as increase in ion energy and in dose due to formation of functional groups such as OH and C-O. Selective attachment of nerve cells was observed on C-implanted them at 10 keV and 3 × 1015 ions/cm2 after in vitro cell culture of nerve cells of PC-12 h. Neurite outgrowth also extended over the implanted area. After dipping in a serum medium and in a fibronectin solution for 2 h, the detection of N 1s electrons by X-ray induced photoelectron spectroscopic (XPS) revealed a significant distinction of protein adhesion on the implanted area. Thus, immobilization of proteins on surface is used for considering the selective cell-attachment. For PLA, the selective attachment of cells and protein depended on the implantation conditions.

  12. Ion-Assisted Pulsed Laser Deposition of amorphous tetrahedral-coordinated carbon films

    Science.gov (United States)

    Friedmann, T. A.; Tallant, D. R.; Sullivan, J. P.; Siegal, M. P.; Simpson, R. L.

    1994-04-01

    A parametric study has been performed of amorphous tetrahedral carbon (a-tC) films produced by ion-assisted pulsed laser deposition (IAPLD). The ion voltage, current density, and feed gas composition (nitrogen in argon) have been varied. The resultant films were characterized by thickness, residual stress, Raman spectroscopy, and electrical resistivity. The Raman spectra have been fit to two gaussian peaks, the so called graphitic (G) peak and the disorder (D) peak. It has been found that the magnitude of the D peak and the residual compressive stress are inversely correlated. At low beam voltages and currents, the magnitude of the D peak is low, increasing as the ion beam voltage and current are raised. The ion beam voltage has the most dramatic effect on the magnitude of the D peak. At low voltages (200-500 V) the magnitude of the D peak is greater for ion beams with high percentages of nitrogen possibly indicative of C-N bonding in the films. At higher voltages (500-1500 V) the D peak intensity is less sensitive to the nitrogen content of the beam.

  13. Determination of Mercury (II Ion on Aryl Amide-Type Podand-Modified Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Sevgi Güney

    2011-01-01

    Full Text Available A new voltammetric sensor based on an aryl amide type podand, 1,8-bis(o-amidophenoxy-3,6-dioxaoctane, (AAP modified glassy carbon electrode, was described for the determination of trace level of mercury (II ion by cyclic voltammetry (CV and differential pulse voltammetry (DPV. A well-defined anodic peak corresponding to the oxidation of mercury on proposed electrode was obtained at 0.2 V versus Ag/AgCl reference electrode. The effect of experimental parameters on differential voltammetric peak currents was investigated in acetate buffer solution of pH 7.0 containing 1 × 10−1 mol L−1 NaCl. Mercury (II ion was preconcentrated at the modified electrode by forming complex with AAP under proper conditions and then reduced on the surface of the electrode. Interferences of Cu2+, Pb2+, Fe3+, Cd2+, and Zn2+ ions were also studied at two different concentration ratios with respect to mercury (II ions. The modified electrode was applied to the determination of mercury (II ions in seawater sample.

  14. Long-term Autophagy and Nrf2 Signaling in the Hippocampi of Developing Mice after Carbon Ion Exposure

    Science.gov (United States)

    Ye, Fei; Zhao, Ting; Liu, Xiongxiong; Jin, Xiaodong; Liu, Xinguo; Wang, Tieshan; Li, Qiang

    2015-12-01

    To explore charged particle radiation-induced long-term hippocampus damage, we investigated the expression of autophagy and antioxidant Nrf2 signaling-related proteins in the mouse hippocampus after carbon ion radiation. Heads of immature female Balb/c mice were irradiated with carbon ions of different LETs at various doses. Behavioral tests were performed on the mice after maturation. Acute and chronic expression of LC3-II, p62/SQSTM1, nuclear Nrf2, activated caspase-3 and the Bax/Bcl-2 ratio were measured in the hippocampi. Secondary X-ray insult was adopted to amplify potential damages. Long-term behavioral changes were observed in high-LET carbon ion-irradiated mice. There were no differences in the rates of LC3-II induction and p62/SQSTM1 degradation compared to the control group regardless of whether the mice received the secondary X-ray insult. A high nuclear Nrf2 content and low apoptosis level in hippocampal cells subjected to secondary X-rays were observed for the mice exposed to relatively low-LET carbon ions. Therefore, carbon ion exposure in the immature mouse led to an LET-dependent behavioral change after maturation. Although autophagy was intact, the persistently high nuclear Nrf2 content in the hippocampus might account for the unchanged behavioral pattern in mice exposed to the relatively low-LET carbon ions and the subsequent increased radioresistance of the hippocampus.

  15. 3D Hollow Sn@Carbon-Graphene Hybrid Material as Promising Anode for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Xiaoyu Zheng

    2014-01-01

    Full Text Available A 3D hollow Sn@C-graphene hybrid material (HSCG with high capacity and excellent cyclic and rate performance is fabricated by a one-pot assembly method. Due to the fast electron and ion transfer as well as the efficient carbon buffer structure, the hybrid material is promising in high-performance lithium-ion battery.

  16. Development of carbon and metallic nano particle composite materials for the determination of uranium and other heavy metal ions

    International Nuclear Information System (INIS)

    Sahoo, S.; Dey, M.K.; Satpati, A.K.; Reddy, A.V.R.

    2014-01-01

    Carbon and metallic nano particle based composite materials were developed and characterised for the determination of heavy metal ions and uranium in trace concentration levels. Composite material were electrodeposited on the substrate electrode and applied for the electrochemical determination of metal ions. Electrodeposition parameters to synthesise the composite material and the analytical parameters for determination were optimised. (author)

  17. Quality of Life in Men Treated With Carbon Ion Therapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Wakatsuki, Masaru; Tsuji, Hiroshi; Ishikawa, Hitoshi; Yanagi, Takeshi; Kamada, Tadashi; Nakano, Takashi; Suzuki, Hiroyoshi; Akakura, Koichiro; Shimazaki, Jun; Tsujii, Hirohiko

    2008-01-01

    Purpose: To prospectively assess patient quality of life (QOL) after carbon ion radiotherapy (C-ion RT) for prostate cancer, using established questionnaires. Methods and Material: The subjects were 150 patients who underwent C-ion RT. Of these, 25 patients with low-risk prostate cancer received C-ion RT alone, whereas the remaining 125 patients with a high-risk tumor also received androgen deprivation therapy. Quality of life was assessed using the self-administered Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire in all patients three times. In addition, University of California-Los Angeles Prostate Cancer Index (UCLA-PCI) was conducted in the low-risk patients. Results: The FACT-General (FACT-G) and FACT-P scores at 12 months after treatment averaged over all 150 patients showed no significant change compared with those before C-ion RT. In FACT-P subscales, emotional well-being increased significantly just after and 12 months after treatment. In contrast, physical well-being (PWB) and social/family well-being (S/FWB) decreased significantly at 12 months, whereas the prostate cancer subscale (PCS) decreased significantly just after treatment. Average scores for FACT-G, FACT-P, PWB, S/FWB, and PCS for the 125 patients receiving hormone therapy showed substantial detrimental changes at 12 months. In contrast, those of the 25 low-risk patients who had no hormone therapy showed no significant change. Similarly no significant change in the average of the UCLA-PCI scores in the low-risk patients was seen at 12 months. Conclusions: Average QOL parameters reported by patients with localized prostate cancer treated with C-ion RT, in the absence of hormone therapy, showed no significant decrease 12 months after C-ion RT

  18. Solar-wind ion interaction with carbonates on the surface of Ceres: Laboratory Experiments

    Science.gov (United States)

    Dukes, C. A.; Bu, C.; Lopez, G. R.; McFadden, L. A.; Ruesch, O.; Li, J. Y.

    2017-12-01

    Bright carbonates deposits on the dark background of Ceres have been identified by Dawn's VIR spectrometer [1, 2], with a composition that varies from Na2CO3 at Oxo crater and the Cerealia and Vinalia Faculae where carbonates are most abundant, to MgCO3 or CaCO3 in other regions [2, 3]. Solar-wind plasma impacts the surface of airless planetary bodies with 1 keV/amu H and He ( 107 ions cm-2 s-1at 2.8 A.U.), causing chemical and physical changes that influence the optical spectra. We investigate the stability of carbonate salts under ion irradiation, monitoring the spectral and compositional change. Anhydrous Na2CO3 (natrite) powders (grains 80% original material reflectance. Both hydrous and anhydrous Na2CO3 show blue/green radio-luminescence under ion impact. Ion-induced darkening of Ceres' natrite deposits is expected to occur on a time-scale of 100 - 1000 years, significantly less than the age of Cerealia facula 7 Ma [4]; darkening can be reversed by exposure to water vapor. For Ceres bright regions of varied albedo, this suggests that the brightest areas are the more recent deposits or the most recently exposed to water by upwelling, venting, or sublimation of subsurface ice [5]. [1] DeSanctis et al (2016) Nature 536, 54 - 57 [2] Palumbo et al (2016) LPSC 47, 2166 [3] Tosi et al (2016) DPS48, 511.06 [4] Nathues et al (2017) APJ 153, 112-124 [5] Titus (2015) GRL 42, 2130-2136

  19. Proton and carbon ion radiotherapy for primary brain tumors and tumors of the skull base

    International Nuclear Information System (INIS)

    Combs, Stephanie E.; Kessel, Kerstin; Habermehl, Daniel; Debus, Jurgen; Haberer, Thomas; Jaekel, Oliver

    2013-01-01

    To analyze clinical concepts, toxicity and treatment outcome in patients with brain and skull base tumors treated with photons and particle therapy. Material and methods: In total 260 patients with brain tumors and tumors of the skull base were treated at the Heidelberg Ion Therapy Center (HIT). Patients enrolled in and randomized within prospective clinical trials as well as bony or soft tissue tumors are not included in this analysis. Treatment was delivered as protons, carbon ions, or combinations of photons and a carbon ion boost. All patients are included in a tight follow-up program. The median follow-up time is 12 months (range 2-39 months). Results: Main histologies included meningioma (n = 107) for skull base lesions, pituitary adenomas (n = 14), low-grade gliomas (n = 51) as well as high-grade gliomas (n = 55) for brain tumors. In all patients treatment could be completed without any unexpected severe toxicities. No side effects > CTC Grade III were observed. To date, no severe late toxicities were observed, however, for endpoints such as secondary malignancies or neuro cognitive side effects follow-up time still remains too short. Local recurrences were mainly seen in the group of high-grade gliomas or atypical meningiomas; for benign skull base meningiomas, to date, no recurrences were observed during follow-up. Conclusion: The specific benefit of particle therapy will potentially reduce the risk of secondary malignancies as well as improve neuro cognitive outcome and quality of life (QOL); thus, longer follow-up will be necessary to confirm these endpoints. Indication-specific trials on meningiomas and gliomas are underway to elucidate the role of protons and carbon ions in these indications

  20. Proton and carbon ion radiotherapy for primary brain tumors and tumors of the skull base

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Stephanie E.; Kessel, Kerstin; Habermehl, Daniel; Debus, Jurgen [Univ. Hospital of Heidelberg, Dept. of Radiation Oncology, Heidelberg (Germany)], e-mail: Stephanie.Combs@med.uni-heidelberg.de; Haberer, Thomas [Heidelberger Ionenstrahl Therapiezentrum (HIT), Heidelberg (Germany); Jaekel, Oliver [Univ. Hospital of Heidelberg, Dept. of Radiation Oncology, Heidelberg (Germany); Heidelberger Ionenstrahl Therapiezentrum (HIT), Heidelberg (Germany)

    2013-10-15

    To analyze clinical concepts, toxicity and treatment outcome in patients with brain and skull base tumors treated with photons and particle therapy. Material and methods: In total 260 patients with brain tumors and tumors of the skull base were treated at the Heidelberg Ion Therapy Center (HIT). Patients enrolled in and randomized within prospective clinical trials as well as bony or soft tissue tumors are not included in this analysis. Treatment was delivered as protons, carbon ions, or combinations of photons and a carbon ion boost. All patients are included in a tight follow-up program. The median follow-up time is 12 months (range 2-39 months). Results: Main histologies included meningioma (n = 107) for skull base lesions, pituitary adenomas (n = 14), low-grade gliomas (n = 51) as well as high-grade gliomas (n = 55) for brain tumors. In all patients treatment could be completed without any unexpected severe toxicities. No side effects > CTC Grade III were observed. To date, no severe late toxicities were observed, however, for endpoints such as secondary malignancies or neuro cognitive side effects follow-up time still remains too short. Local recurrences were mainly seen in the group of high-grade gliomas or atypical meningiomas; for benign skull base meningiomas, to date, no recurrences were observed during follow-up. Conclusion: The specific benefit of particle therapy will potentially reduce the risk of secondary malignancies as well as improve neuro cognitive outcome and quality of life (QOL); thus, longer follow-up will be necessary to confirm these endpoints. Indication-specific trials on meningiomas and gliomas are underway to elucidate the role of protons and carbon ions in these indications.

  1. Synthesis of carbon nanoparticles using one step green approach and their application as mercuric ion sensor

    Energy Technology Data Exchange (ETDEWEB)

    Roshni, V.; Ottoor, Divya, E-mail: divya@chem.unipune.ac.in

    2015-05-15

    Carbon nanoparticles (CNPs) have been evolved as a promising candidate for the metal sensing applications due to their synthesis from naturally occurring and easily available non-toxic molecular precursors by green chemistry. A simple and one step procedure is reported here for the synthesis of CNPs from coconut milk by thermal pyrolysis at a temperature of 120–150 °C for 2–5 min without using any carbonizing or passivating agent. On pyrolysis the coconut oil is separated from the carbon rich residue and the residue when dissolved in water showed blue fluorescence under UV light. The CNPs produced are found to show an emission maximum at 440 nm when excited at 360 nm. Synthesis by green approach makes CNPs a promising substitute for the metal sensing applications. Series of metal ions which have a hazardous impact on the ecological system have been taken for the analysis and it is observed that the fluorescence of CNPs gets remarkably quenched by mercuric ions. Fluorescence quenching was studied using standard Stern–Volmer quenching model. Limit of detection was found to be 16.5 nM Hg{sup 2+} concentration. - Highlights: • Green and economical synthesis of carbon nanoparticles (CNPs) from naturally abundant material. • Coconut milk is used as molecular precursor, which on thermal pyrolysis at 120 °C yielded CNPs. • Highly fluorescent CNPs show an emission maxima of 440 nm when excited at 360 nm. • Application of CNPs for metal ion sensing using fluorescence quenching phenomena. • Hg{sup 2+} is most effectively sensed with a detection limit of 16.5 nM.

  2. Synthesis of carbon nanoparticles using one step green approach and their application as mercuric ion sensor

    International Nuclear Information System (INIS)

    Roshni, V.; Ottoor, Divya

    2015-01-01

    Carbon nanoparticles (CNPs) have been evolved as a promising candidate for the metal sensing applications due to their synthesis from naturally occurring and easily available non-toxic molecular precursors by green chemistry. A simple and one step procedure is reported here for the synthesis of CNPs from coconut milk by thermal pyrolysis at a temperature of 120–150 °C for 2–5 min without using any carbonizing or passivating agent. On pyrolysis the coconut oil is separated from the carbon rich residue and the residue when dissolved in water showed blue fluorescence under UV light. The CNPs produced are found to show an emission maximum at 440 nm when excited at 360 nm. Synthesis by green approach makes CNPs a promising substitute for the metal sensing applications. Series of metal ions which have a hazardous impact on the ecological system have been taken for the analysis and it is observed that the fluorescence of CNPs gets remarkably quenched by mercuric ions. Fluorescence quenching was studied using standard Stern–Volmer quenching model. Limit of detection was found to be 16.5 nM Hg 2+ concentration. - Highlights: • Green and economical synthesis of carbon nanoparticles (CNPs) from naturally abundant material. • Coconut milk is used as molecular precursor, which on thermal pyrolysis at 120 °C yielded CNPs. • Highly fluorescent CNPs show an emission maxima of 440 nm when excited at 360 nm. • Application of CNPs for metal ion sensing using fluorescence quenching phenomena. • Hg 2+ is most effectively sensed with a detection limit of 16.5 nM

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

    CERN Document Server

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

    2011-01-01

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

  4. Electrode fabrication for Lithium-ion batteries by intercalating of carbon nano tubes inside nano metric pores of silver foam

    International Nuclear Information System (INIS)

    Khoshnevisan, B.

    2011-01-01

    Here there is an on effort to improve working electrode (Ag + carbon nano tubes) preparation for Li-Ion batteries applications. Nano scaled silver foam with high specific area has been employed as a frame for loading carbon nano tubes by electrophoretic deposition method. In this ground, the prepared electrodes show a very good stability and also charge-discharge cycles reversibility.

  5. Hierarchically porous carbon with high-speed ion transport channels for high performance supercapacitors

    Science.gov (United States)

    Lu, Haoyuan; Li, Qingwei; Guo, Jianhui; Song, Aixin; Gong, Chunhong; Zhang, Jiwei; Zhang, Jingwei

    2018-01-01

    Hierarchically porous carbons (HPC) are considered as promising electrode materials for supercapacitors, due to their outstanding charge/discharge cycling stabilities and high power densities. However, HPC possess a relatively low ion diffusion rate inside the materials, which challenges their application for high performance supercapacitor. Thus tunnel-shaped carbon pores with a size of tens of nanometers were constructed by inducing the self-assembly of lithocholic acid with ammonium chloride, thereby providing high-speed channels for internal ion diffusion. The as-formed one-dimensional pores are beneficial to the activation process by KOH, providing a large specific surface area, and then facilitate rapid transport of electrolyte ions from macropores to the microporous surfaces. Therefore, the HPC achieve an outstanding gravimetric capacitance of 284 F g-1 at a current density of 0.1 A g-1 and a remarkable capacity retention of 64.8% when the current density increases by 1000 times to 100 A g-1.

  6. Carbon aerogel with 3-D continuous skeleton and mesopore structure for lithium-ion batteries application

    International Nuclear Information System (INIS)

    Yang, Xiaoqing; Huang, Hong; Zhang, Guoqing; Li, Xinxi; Wu, Dingcai; Fu, Ruowen

    2015-01-01

    Carbon aerogel (CA) with 3-D continuous skeleton and mesopore structure was prepared via a microemulsion-templated sol–gel polymerization method and then used as the anode materials of lithium-ion batteries. It was found that the reversible specific capacity of the as-prepared CAs could stay at about 470 mA h g −1 for 80 cycles, much higher than the theoretical capacity of commercial graphite (372 mAh g −1 ). In addition, CA also showed a better rate capacity compared to commercial graphite. The good electrochemical properties could be ascribed to the following three factors: (1) the large BET surface area of 620 m 2  g −1 , which can provide more lithium ion insertion sites, (2) 3-D continuous skeleton of CAs, which favors the transport of the electrons, (3) 3-D continuous mesopore structure with narrow mesopore size distribution and high mesopore ratio of 87.3%, which facilitates the diffusion and transport of the electrolyte and lithium ions. - Highlights: • Carbon aerogel (CA) was prepared via a microemulsion-templated sol–gel method. • The CA presents high surface area, 3D continuous skeleton and mesopore structure. • The reversible capacity of CA is much higher than that of graphite

  7. Evaluation of an empirical monitor output estimation in carbon ion radiotherapy.

    Science.gov (United States)

    Matsumura, Akihiko; Yusa, Ken; Kanai, Tatsuaki; Mizota, Manabu; Ohno, Tatsuya; Nakano, Takashi

    2015-09-01

    A conventional broad beam method is applied to carbon ion radiotherapy at Gunma University Heavy Ion Medical Center. According to this method, accelerated carbon ions are scattered by various beam line devices to form 3D dose distribution. The physical dose per monitor unit (d/MU) at the isocenter, therefore, depends on beam line parameters and should be calibrated by a measurement in clinical practice. This study aims to develop a calculation algorithm for d/MU using beam line parameters. Two major factors, the range shifter dependence and the field aperture effect, are measured via PinPoint chamber in a water phantom, which is an identical setup as that used for monitor calibration in clinical practice. An empirical monitor calibration method based on measurement results is developed using a simple algorithm utilizing a linear function and a double Gaussian pencil beam distribution to express the range shifter dependence and the field aperture effect. The range shifter dependence and the field aperture effect are evaluated to have errors of 0.2% and 0.5%, respectively. The proposed method has successfully estimated d/MU with a difference of less than 1% with respect to the measurement results. Taking the measurement deviation of about 0.3% into account, this result is sufficiently accurate for clinical applications. An empirical procedure to estimate d/MU with a simple algorithm is established in this research. This procedure allows them to use the beam time for more treatments, quality assurances, and other research endeavors.

  8. All-carbon-based porous topological semimetal for Li-ion battery anode material.

    Science.gov (United States)

    Liu, Junyi; Wang, Shuo; Sun, Qiang

    2017-01-24

    Topological state of matter and lithium batteries are currently two hot topics in science and technology. Here we combine these two by exploring the possibility of using all-carbon-based porous topological semimetal for lithium battery anode material. Based on density-functional theory and the cluster-expansion method, we find that the recently identified topological semimetal bco-C 16 is a promising anode material with higher specific capacity (Li-C 4 ) than that of the commonly used graphite anode (Li-C 6 ), and Li ions in bco-C 16 exhibit a remarkable one-dimensional (1D) migration feature, and the ion diffusion channels are robust against the compressive and tensile strains during charging/discharging. Moreover, the energy barrier decreases with increasing Li insertion and can reach 0.019 eV at high Li ion concentration; the average voltage is as low as 0.23 V, and the volume change during the operation is comparable to that of graphite. These intriguing theoretical findings would stimulate experimental work on topological carbon materials.

  9. Microstructure of carbon derived from mangrove charcoal and its application in Li-ion batteries

    International Nuclear Information System (INIS)

    Liu Tao; Luo Ruiying; Qiao Wenming; Yoon, Seong-Ho; Mochida, Isao

    2010-01-01

    In this study, the microstructure of mangrove-charcoal-derived carbon (MC) was studied using XRD, STM and TEM. MC was found to consist of aligned quasi-spherical structural units with diameters of around 5-20 nm. It shows typical hard carbon characteristics, including a strongly disoriented single graphene layer and BSU, formed by two or three graphene layers stacked nearly parallel. Some curved and faceted graphene layers, especially closed carbon nanoparticles with fullerene-like, were observed in the as-prepared samples. MC was also evaluated as an anodic material for Li-ion batteries. MC carbonized at 1000 deg. C possessed the highest available discharge capacity (below 0.5 V) of 335 mAh g -1 , the high first-cycle coulombic efficiency of 73.7%, good rate and cyclic capability and PC-based electrolyte compatibility. 7 Li nuclear magnetic resonance (NMR) spectra of fully lithiated mangrove charcoal-derived carbons indicated the co-existence of three Li species.

  10. Corrosion of Carbon Steel and Corrosion-Resistant Rebars in Concrete Structures Under Chloride Ion Attack

    Science.gov (United States)

    Mohamed, Nedal; Boulfiza, Mohamed; Evitts, Richard

    2013-03-01

    Corrosion of reinforced concrete is the most challenging durability problem that threatens reinforced concrete structures, especially structures that are subject to severe environmental conditions (i.e., highway bridges, marine structures, etc.). Corrosion of reinforcing steel leads to cracking and spalling of the concrete cover and billions of dollars are spent every year on repairing such damaged structures. New types of reinforcements have been developed to avoid these high-cost repairs. Thus, it is important to study the corrosion behavior of these new types of reinforcements and compare them to the traditional carbon steel reinforcements. This study aimed at characterizing the corrosion behavior of three competing reinforcing steels; conventional carbon steel, micro-composite steel (MMFX-2) and 316LN stainless steel, through experiments in carbonated and non-carbonated concrete exposed to chloride-laden environments. Synthetic pore water solutions have been used to simulate both cases of sound and carbonated concrete under chloride ions attack. A three-electrode corrosion cell is used for determining the corrosion characteristics and rates. Multiple electrochemical techniques were applied using a Gamry PC4™ potentiostat manufactured by Gamry Instruments (Warminster, PA). DC corrosion measurements were applied on samples subjected to fixed chloride concentration in the solution.

  11. Biomass carbon composited FeS2 as cathode materials for high-rate rechargeable lithium-ion battery

    Science.gov (United States)

    Xu, Xin; Meng, Zhen; Zhu, Xueling; Zhang, Shunlong; Han, Wei-Qiang

    2018-03-01

    Pyrite FeS2 has long been used as commercial primary lithium batteries at room temperature. To achieve rechargeable FeS2 battery, biomass-carbon@FeS2 composites are prepared using green and renewable auricularia auricula as carbon source through the process of carbonization and sulfuration. The auricularia auricula has strong swelling characteristics to absorb aqueous solution which can effectively absorb Fe ions into its body. FeS2 homogeneously distributed in biomass carbon matrix performs high electronic and ionic conductivity. The specific capacity of biomass-carbon@FeS2 composites remains 850 mAh g-1 after 80 cycles at 0.5C and 700 mAh g-1 at the rate of 2C after 150 cycles. Biomass-carbon@FeS2 composites exhibit high-rate capacity in lithium-ion battery.

  12. Annealing effects on the migration of ion-implanted cadmium in glassy carbon

    Energy Technology Data Exchange (ETDEWEB)

    Hlatshwayo, T.T., E-mail: thulani.hlatshwayo@up.ac.za [Physics Department, University of Pretoria, Pretoria (South Africa); Sebitla, L.D. [Physics Department, University of Pretoria, Pretoria (South Africa); Physics Department, University of Botswana, Gaborone (Botswana); Njoroge, E.G.; Mlambo, M.; Malherbe, J.B. [Physics Department, University of Pretoria, Pretoria (South Africa)

    2017-03-15

    The migration behaviour of cadmium (Cd) implanted into glassy carbon and the effects of annealing on radiation damage introduced by ion implantation were investigated. The glassy carbon substrates were implanted with Cd at a dose of 2 × 10{sup 16} ions/cm{sup 2} and energy of 360 keV. The implantation was performed at room temperature (RT), 430 °C and 600 °C. The RT implanted samples were isochronally annealed in vacuum at 350, 500 and 600 °C for 1 h and isothermally annealed at 350 °C up to 4 h. The as-implanted and annealed samples were characterized by Raman spectroscopy and Rutherford backscattering spectrometry (RBS). Raman results revealed that implantation at room temperature amorphized the glassy carbon structure while high temperature implantations resulted in slightly less radiation damage. Isochronal annealing of the RT implanted samples resulted in some recrystallization as a function of increasing temperature. The original glassy carbon structure was not achieved at the highest annealing temperature of 600 °C. Diffusion of Cd in glassy carbon was already taking place during implantation at 430 °C. This diffusion of Cd was accompanied by significant loss from the surface during implantation at 600 °C. Isochronal annealing of the room temperature implanted samples at 350 °C for 1 h caused Cd to diffuse towards the bulk while isothermal annealing at 500 and 600 °C resulted in the migration of implanted Cd toward the surface accompanied by a loss of Cd from the surface. Isothermal annealing at 350 °C for 1 h caused Cd to diffuse towards the bulk while for annealing time >1 h Cd diffused towards the surface. These results were interpreted in terms of trapping and de-trapping of implanted Cd by radiation damage.

  13. Using the Orbit Tracking Code Z3CYCLONE to Predict the Beam Produced by a Cold Cathode PIG Ion Source for Cyclotrons under DC Extraction

    CERN Document Server

    Forringer, Edward

    2005-01-01

    Experimental measurements of the emittance and luminosity of beams produced by a cold-cathode Phillips Ionization Guage (PIG) ion source for cyclotrons under dc extraction are reviewed. (The source being studied is of the same style as ones that will be used in a series of 250 MeV proton cyclotrons being constructed for cancer therapy by ACCEL Inst, Gmbh, of Bergisch Gladbach, Germany.) The concepts of 'plasma boundary' and 'plasma temperature' are presented as a useful set of parameters for describing the initial conditions used in computational orbit tracking. Experimental results for r-pr and z-pz emittance are compared to predictions from the MSU orbit tracking code Z3CYCLONE with results indicating that the code is able to predict the beam produced by these ion sources with adequate accuracy such that construction of actual cyclotrons can proceed with reasonably prudent confidence that the cyclotron will perform as predicted.

  14. Hydrazinylpyridine based highly selective optical sensor for aqueous source of carbonate ions: Electrochemical and DFT studies

    Science.gov (United States)

    Thimaradka, Vikram; Pangannaya, Srikala; Mohan, Makesh; Trivedi, Darshak R.

    2018-03-01

    A series of new receptors PDZ1-3 based on 2-(arylidenehydrazinyl)pyridines have been designed and synthesized for the detection of biologically and environmentally important ions. The colorimetric detection of CO32 - using neutral organic receptor PDZ-1 has been achieved with characteristic visual colour change from yellow to green accompanied by a large redshift of 215 nm in absorption maxima. UV-Vis spectroscopic and cyclic voltammetric studies reveal the stoichiometry of binding and electrochemistry of host-guest complex formation. The binding constant was found to be 0.77 × 104 M- 2. In addition, electrochemical studies provide an insight into the stability of the complex. DFT studies performed on the PDZ-1 and PDZ-1 - CO32 - complex reveal the binding mechanism involved in the anion detection process. PDZ-1 is highly selective for carbonate and does not show any colorimetric response towards any other anions or cations, while PDZ-2 and PDZ-3 remain inactive in the ion detection process. The limit of detection (LOD) and limit of quantification (LOQ) of PDZ-1 for carbonate was found to be 0.11 mM and 0.36 mM respectively. Considerable binding constant and limit of detection make PDZ-1 to be used as a real time sensor for the detection of carbonate in environmental and biological samples.

  15. Effects of gamma-ray and high energy carbon ion irradiation on swimming velocity of Euglena gracilis

    Science.gov (United States)

    Sakashita, T.; Doi, M.; Yasuda, H.; Fuma, S.; Häder, D.-P.

    The effects of gamma-ray and high energy carbon ion irradiation on the swimming velocity of the photosynthetic flagellate Euglena gracilis strain Z were studied, focusing on a dose-effect relationship. Cells were exposed to 60Co gamma-rays at 6 doses of 10, 15, 20, 40, 100 and 200 Gy for water, and also to 290 MeV/amu carbon ions from the Heavy Ion Medical Accelerator in Chiba at 7 doses (5, 10, 15, 20, 50, 100 and 200 Gy for water). The swimming velocity was measured by a biomonitoring system, called ECOTOX. The swimming velocities of Euglena gracilis cells were significantly decreased by >40 Gy gamma-rays and >5 Gy carbon ions, respectively. The 50% effective doses for inhibition, 34±4 Gy (gamma-rays) and 13±1 Gy (290 MeV/amu carbon ions), were estimated from the best fit to data of the logistic model. The relative biological effectiveness (2.6±0.4) was calculated by the ratio of 50% effective doses. The inhibition of the swimming velocity of the cells irradiated with gamma-rays was still present after 3 days, while recovery of the swimming velocity was shown in the cells exposed to 290 MeV/amu carbon ions. It is suggested that ionizing radiation inhibits ATP production and/or increases frictional drag on beating of the flagellum, thus decreasing swimming velocity.

  16. Evaluation of Different Single-Walled Carbon Nanotube Surface Coatings for Single-Particle Tracking Applications in Biological Environments.

    Science.gov (United States)

    Gao, Zhenghong; Danné, Noémie; Godin, Antoine Guillaume; Lounis, Brahim; Cognet, Laurent

    2017-11-16

    Fluorescence imaging of biological systems down to the single-molecule level has generated many advances in cellular biology. For applications within intact tissue, single-walled carbon nanotubes (SWCNTs) are emerging as distinctive single-molecule nanoprobes, due to their near-infrared photoluminescence properties. For this, SWCNT surfaces must be coated using adequate molecular moieties. Yet, the choice of the suspension agent is critical since it influences both the chemical and emission properties of the SWCNTs within their environment. Here, we compare the most commonly used surface coatings for encapsulating photoluminescent SWCNTs in the context of bio-imaging applications. To be applied as single-molecule nanoprobes, encapsulated nanotubes should display low cytotoxicity, and minimal unspecific interactions with cells while still being highly luminescent so as to be imaged and tracked down to the single nanotube level for long periods of time. We tested the cell proliferation and cellular viability of each surface coating and evaluated the impact of the biocompatible surface coatings on nanotube photoluminescence brightness. Our study establishes that phospholipid-polyethylene glycol-coated carbon nanotube is the best current choice for single nanotube tracking experiments in live biological samples.

  17. The effects of silicon doping on the performance of PMAN carbon anodes in Li-ion cells

    Energy Technology Data Exchange (ETDEWEB)

    Guidotti, R.A.; Johnson, B.J. [Sandia National Labs., Albuquerque, NM (United States); Even, W. Jr. [Sandia National Labs., Livermore, CA (United States)

    1996-05-01

    Carbons derived from polymethylacrylonitrile (PMAN) have been studied for use as intercalation anodes in Li-ion cells. The effect of Si doping upon the electrochemical performance of PMAN carbons was studied using tetravinylsilane (TVS) and tetramethysilane (TMS) as sources of Si during the formation of the PMAN precursors. The carbons were characterized by galvanostatic cycling, cyclic voltammetry, and complex impedance. The presence of 9 to 11 w/o Si in the PMAN lattice greatly increased the irreversible capacity of these materials.

  18. Strain-dependent Damage in Mouse Lung After Carbon Ion Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Moritake, Takashi [Advanced Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Proton Medical Research Center, University of Tsukuba, Tsukuba (Japan); Fujita, Hidetoshi; Yanagisawa, Mitsuru; Nakawatari, Miyako; Imadome, Kaori; Nakamura, Etsuko; Iwakawa, Mayumi [Advanced Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Imai, Takashi, E-mail: imait@nirs.go.jp [Advanced Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan)

    2012-09-01

    Purpose: To examine whether inherent factors produce differences in lung morbidity in response to carbon ion (C-ion) irradiation, and to identify the molecules that have a key role in strain-dependent adverse effects in the lung. Methods and Materials: Three strains of female mice (C3H/He Slc, C57BL/6J Jms Slc, and A/J Jms Slc) were locally irradiated in the thorax with either C-ion beams (290 MeV/n, in 6 cm spread-out Bragg peak) or with {sup 137}Cs {gamma}-rays as a reference beam. We performed survival assays and histologic examination of the lung with hematoxylin-eosin and Masson's trichrome staining. In addition, we performed immunohistochemical staining for hyaluronic acid (HA), CD44, and Mac3 and assayed for gene expression. Results: The survival data in mice showed a between-strain variance after C-ion irradiation with 10 Gy. The median survival time of C3H/He was significantly shortened after C-ion irradiation at the higher dose of 12.5 Gy. Histologic examination revealed early-phase hemorrhagic pneumonitis in C3H/He and late-phase focal fibrotic lesions in C57BL/6J after C-ion irradiation with 10 Gy. Pleural effusion was apparent in C57BL/6J and A/J mice, 168 days after C-ion irradiation with 10 Gy. Microarray analysis of irradiated lung tissue in the three mouse strains identified differential expression changes in growth differentiation factor 15 (Gdf15), which regulates macrophage function, and hyaluronan synthase 1 (Has1), which plays a role in HA metabolism. Immunohistochemistry showed that the number of CD44-positive cells, a surrogate marker for HA accumulation, and Mac3-positive cells, a marker for macrophage infiltration in irradiated lung, varied significantly among the three mouse strains during the early phase. Conclusions: This study demonstrated a strain-dependent differential response in mice to C-ion thoracic irradiation. Our findings identified candidate molecules that could be implicated in the between-strain variance to early

  19. Impedance study of the ion-to-electron transduction process for carbon cloth as solid-contact material in potentiometric ion sensors

    International Nuclear Information System (INIS)

    Mattinen, Ulriika; Rabiej, Sylwia; Lewenstam, Andrzej; Bobacka, Johan

    2011-01-01

    Carbon cloth was studied as solid-contact material in potentiometric ion sensors by using electrochemical impedance spectroscopy and potentiometry. The ion-to-electron transduction process was studied by electrochemical impedance spectroscopy by using a two-electrode symmetrical cell where a liquid electrolyte was sandwiched between two solid electrodes, including bare glassy carbon (GC), GC/carbon cloth and GC/poly(3,4-ethylenedioxythiophene). Impedance data for different electrode/electrolyte combinations were evaluated and compared. Solid-contact K + -selective electrodes were fabricated by coating the carbon cloth with a conventional plasticized PVC-based K + -selective membrane via drop casting. These K + -sensors showed proper analytical performance and acceptable long-term potential stability (potential drift ≈ 1 mV/day). Solid contact reference electrodes were fabricated in an analogous manner by coating the carbon cloth with a plasticized PVC membrane containing a moderately lipophilic salt. The results indicate that carbon cloth can be used as a solid-contact material in potentiometric ion sensors and pseudo-reference electrodes.

  20. The Incorporation of Lithium Alloying Metals into Carbon Matrices for Lithium Ion Battery Anodes

    Science.gov (United States)

    Hays, Kevin A.

    arsenic particles that were synthesized on melt away carbon nanotubes by akalide reduction. The performance of these anodes proved sensitive to electrolyte composition, which was significantly improved by using fluorinated ethylene carbonate. Additionally, further gains in capacity retention can be made by limiting the loading voltage to 0.75 V vs lithium metal. The arsenic and melt away carbon nanotube composite was found to have excellent cycle life and capacity at high mass loading (80% arsenic) when the nanoparticles were directly synthesized on the melt away carbon nanotubes. Gallium arsenide is well known for its semiconducting properties, but its performance as in Li-ion battery anodes is first reported here. Gallium is a metal with a low melting point that has been touted as a possible self-healing material for lithium ion anodes. Alone, gallium proves to be unstable as a lithium ion battery anode, but when synthesized as gallium arsenide nanoparticles and mixed with melt away carbon nanotubes it can charge and discharge in a battery 100 times with approximately twice the capacity of graphite anodes. This first study of gallium arsenide shows dramatic cycle life improvements by using nanoscale rather that micron size gallium arsenide.

  1. Electrochemical Performance of Electrospun carbon nanofibers as free-standing and binder-free anodes for Sodium-Ion and Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Jin, Juan; Shi, Zhi-qiang; Wang, Cheng-yang

    2014-01-01

    Highlights: • Electrospun carbon nanofiber webs were prepared by pyrolysis of polyacrylonitrile. • The webs as binder-free and current collector-free electrodes for SIBs and LIBs. • Different layer spacing and pore size for Li and Na lead different electrochemical behavior. • Electrochemical performances of the electrodes were high. - Abstract: A series of hard carbon nanofiber-based electrodes derived from electrospun polyacrylonitrile (PAN) nanofibers (PAN-CNFs) have been fabricated by stabilization in air at about 280 °C and then carbonization in N 2 at heat treatment temperatures (HTT) between 800 and 1500 °C. The electrochemical performances of the binder-free, current collector-free carbon nanofiber-based anodes in lithium-ion batteries and sodium-ion batteries are systematically investigated and compared. We demonstrate the presence of similar alkali metal insertion mechanisms in both cases, but just the differences of the layer spacing and pore size available for lithium and sodium ion lead the discharge capacity delivered at sloping region and plateau region to vary from the kinds of alkali elements. Although the anodes in sodium-ion batteries show poorer rate capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 275 mAh g −1 and similar cycling stability due to the conductive 3-D network, weakly ordered turbostratic structure and a large interlayer spacing between graphene sheets. The feature of high capacity and stable cycling performance makes PAN-CNFs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries

  2. Optical properties of K9 glass waveguides fabricated by using carbon-ion implantation

    Science.gov (United States)

    Liu, Chun-Xiao; Wei, Wei; Fu, Li-Li; Zhu, Xu-Feng; Guo, Hai-Tao; Li, Wei-Nan; Lin, She-Bao

    2016-07-01

    K9 glass is a material with promising properties that make it attractive for optical devices. Ion implantation is a powerful technique to form waveguides with controllable depth and refractive index profile. In this work, optical planar waveguide structures were fabricated in K9 glasses by using 6.0-MeV C3+-ion implantation with a fluence of 1.0 × 1015 ions/cm2. The effective refractive indices of the guided modes were measured by using a prism-coupling system. The refractive index change in the ion-irradiated region was simulated by using the intensity calculation method. The modal intensity profile of the waveguide was calculated and measured by using the finite difference beam propagation method and the end-face coupling technique, respectively. The transmission spectra before and after the implantation showed that the main absorption band was not influenced by the low fluence dopants. The optical properties of the carbon-implanted K9 glass waveguides show promise for use as integrated photonic devices.

  3. Dose profile monitoring with carbon ions by means of prompt-gamma measurements

    Energy Technology Data Exchange (ETDEWEB)

    Testa, E. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France)], E-mail: e.testa@ipnl.in2p3.fr; Bajard, M.; Chevallier, M.; Dauvergne, D.; Le Foulher, F. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France); Freud, N.; Letang, J.M. [Institut National des Sciences Appliquees de Lyon, Laboratoire de Controle Non-Destructif par Rayonnements Ionisants (France); Poizat, J.C.; Ray, C.; Testa, M. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France)

    2009-03-15

    A key point in the quality control of ion therapy is real-time monitoring and imaging of the dose delivered to the patient. Among the possible signals that can be used to make such a monitoring, prompt gamma-rays issued from nuclear fragmentation are possible candidates, provided the correlation between the emission profile and the primary beam range can be established. By means of simultaneous energy and time-of-flight discrimination, we could measure the longitudinal profile of the prompt gamma-rays emitted by 73 MeV/u carbon ions stopping inside a PMMA target. This technique allowed us to minimize the shielding against neutrons and scattered gamma rays, and to find a good correlation between the prompt-gamma profile and the ion range. This profile was studied as a function of the observation angle. By extrapolating our results to higher energies and realistic detection efficiencies, we showed that prompt gamma-ray measurements make it feasible to control in real time the longitudinal dose during ion therapy treatments.

  4. Development of NIRS pencil beam scanning system for carbon ion radiotherapy

    Science.gov (United States)

    Furukawa, T.; Hara, Y.; Mizushima, K.; Saotome, N.; Tansho, R.; Saraya, Y.; Inaniwa, T.; Mori, S.; Iwata, Y.; Shirai, T.; Noda, K.

    2017-09-01

    At Heavy Ion Medical Accelerator in Chiba (HIMAC) in National Institute of Radiological Sciences (NIRS), more than 9000 patients have been successfully treated by carbon ion beams since 1994. The successful results of treatments have led us to construct a new treatment facility equipped with a three-dimensional pencil beam scanning irradiation system, which is one of sophisticated techniques for cancer therapy with high energetic ion beam. This new facility comprises two treatment rooms having fixed beam lines and one treatment room having rotating gantry line. The challenge of this project is to realize treatment of a moving target by scanning irradiation. Thus, to realize this, the development of the fast scanning system is one of the most important issues in this project. After intense commissioning and quality assurance tests, the treatment with scanned ion beam was started in May 2011. After treatment of static target starts, we have developed related technologies. As a result, we can start treatment of moving target and treatment without range shifter plates since 2015. In this paper, the developments of the scanning irradiation system are described.

  5. Chromosome inversions in lymphocytes of prostate cancer patients treated with X-rays and carbon ions

    International Nuclear Information System (INIS)

    Pignalosa, Diana; Lee, Ryonfa; Hartel, Carola; Sommer, Sylvester; Nikoghosyan, Anna; Debus, Jürgen; Ritter, Sylvia; Durante, Marco

    2013-01-01

    Background and purpose: To investigate the cytogenetic damage of the intrachange type in peripheral blood lymphocytes of patients treated for prostate cancer with different radiation qualities. Material and methods: Prostate cancer patients were enrolled in a clinical trial based at the Heidelberg University Hospital and at the GSI Helmholtz Centre for Heavy Ion Research in 2006. Patients were treated either with intensity-modulated radiation therapy (IMRT) alone or with a carbon-ion boost followed by IMRT. Blood samples were collected at the end of the therapy and the mBAND technique was used to investigate the cytogenetic damage of the inter and intrachange types. Moreover, the mBAND analysis was performed on healthy donor cells irradiated in vitro with X-rays or C-ions. Results: Our results show no statistically significant differences in the yield and the spectrum of chromosome aberrations among patients treated only with IMRT and patients receiving the combined treatment when similar target volumes and doses to the target are compared. Conclusion: The study suggests that the risks of normal tissue late effects and second malignancies in prostate cancer patients are comparable when heavy ions or IMRT radiotherapy are applied

  6. Radiosensitizing effect of gold nanoparticles in carbon ion irradiation of human cervical cancer cells

    Science.gov (United States)

    Kaur, Harminder; Avasthi, D. K.; Pujari, Geetanjali; Sarma, Asitikantha

    2013-07-01

    Noble metal nanoparticles have received considerable attention in biotechnology for their role in bio sensing due to surface plasmon resonance, medical diagnostics due to better imaging contrast and therapy. The radiosensitization effect of gold nanoparticles (AuNP) has been gaining popularity in radiation therapy of cancer cells. The better depth dose profile of energetic ion beam proves its superiority over gamma radiation for fighting against cancer. In the present work, the glucose capped gold nanoparticles (Glu-AuNP) were synthesised and internalized in the HeLa cells. Transmission electron microscopic analysis of ultrathin sections of Glu-AuNP treated HeLa cells confirmed the internalization of Glu-AuNPs. Control HeLa cells and Glu-AuNp treated HeLa cells were irradiated at different doses of 62 MeV 12C ion beam (LET - 290keV/μm) at BIO beam line of using 15UD Pelletron accelerator at Inter University Accelerator Centre, New Delhi, India. The survival fraction was assessed by colony forming assay which revealed that the dose of carbon ion for 90% cell killing in Glu-AuNP treated HeLa cells and control HeLa cells are 2.3 and 3.2 Gy respectively. This observation shows ˜ 28% reduction of 12C6+ ion dose for Glu-AuNP treated HeLa cells as compared to control HeLa cells.

  7. Radiosensitizing effect of gold nanoparticles in carbon ion irradiation of human cervical cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Harminder; Avasthi, D. K.; Pujari, Geetanjali; Sarma, Asitikantha [Inter University Accelerator Centre, Aruna Asaf Ali Marg, Post box-10502, New Delhi-110067 (India)

    2013-07-18

    Noble metal nanoparticles have received considerable attention in biotechnology for their role in bio sensing due to surface plasmon resonance, medical diagnostics due to better imaging contrast and therapy. The radiosensitization effect of gold nanoparticles (AuNP) has been gaining popularity in radiation therapy of cancer cells. The better depth dose profile of energetic ion beam proves its superiority over gamma radiation for fighting against cancer. In the present work, the glucose capped gold nanoparticles (Glu-AuNP) were synthesised and internalized in the HeLa cells. Transmission electron microscopic analysis of ultrathin sections of Glu-AuNP treated HeLa cells confirmed the internalization of Glu-AuNPs. Control HeLa cells and Glu-AuNp treated HeLa cells were irradiated at different doses of 62 MeV 12C ion beam (LET - 290keV/{mu}m) at BIO beam line of using 15UD Pelletron accelerator at Inter University Accelerator Centre, New Delhi, India. The survival fraction was assessed by colony forming assay which revealed that the dose of carbon ion for 90% cell killing in Glu-AuNP treated HeLa cells and control HeLa cells are 2.3 and 3.2 Gy respectively. This observation shows {approx} 28% reduction of {sup 12}C{sup 6+} ion dose for Glu-AuNP treated HeLa cells as compared to control HeLa cells.

  8. Quantitative evaluation of potential irradiation geometries for carbon-ion beam grid therapy.

    Science.gov (United States)

    Tsubouchi, Toshiro; Henry, Thomas; Ureba, Ana; Valdman, Alexander; Bassler, Niels; Siegbahn, Albert

    2018-03-01

    Radiotherapy using grids containing cm-wide beam elements has been carried out sporadically for more than a century. During the past two decades, preclinical research on radiotherapy with grids containing small beam elements, 25 μm-0.7 mm wide, has been performed. Grid therapy with larger beam elements is technically easier to implement, but the normal tissue tolerance to the treatment is decreasing. In this work, a new approach in grid therapy, based on irradiations with grids containing narrow carbon-ion beam elements was evaluated dosimetrically. The aim formulated for the suggested treatment was to obtain a uniform target dose combined with well-defined grids in the irradiated normal tissue. The gain, obtained by crossfiring the carbon-ion beam grids over a simulated target volume, was quantitatively evaluated. The dose distributions produced by narrow rectangular carbon-ion beams in a water phantom were simulated with the PHITS Monte Carlo code. The beam-element height was set to 2.0 cm in the simulations, while the widths varied from 0.5 to 10.0 mm. A spread-out Bragg peak (SOBP) was then created for each beam element in the grid, to cover the target volume with dose in the depth direction. The dose distributions produced by the beam-grid irradiations were thereafter constructed by adding the dose profiles simulated for single beam elements. The variation of the valley-to-peak dose ratio (VPDR) with depth in water was thereafter evaluated. The separation of the beam elements inside the grids were determined for different irradiation geometries with a selection criterion. The simulated carbon-ion beams remained narrow down to the depths of the Bragg peaks. With the formulated selection criterion, a beam-element separation which was close to the beam-element width was found optimal for grids containing 3.0-mm-wide beam elements, while a separation which was considerably larger than the beam-element width was found advantageous for grids containing 0.5-mm

  9. Electrochemical lithium-ion storage properties of quinone molecules encapsulated in single-walled carbon nanotubes.

    Science.gov (United States)

    Ishii, Yosuke; Tashiro, Kosuke; Hosoe, Kento; Al-Zubaidi, Ayar; Kawasaki, Shinji

    2016-04-21

    We investigated the electrochemical lithium-ion storage properties of 9,10-anthraquinone (AQ) and 9,10-phenanthrenequinone (PhQ) molecules encapsulated in the inner hollow core of single-walled carbon nanotubes (SWCNTs). The structural properties of the obtained encapsulated systems were characterized by electron microscopy, synchrotron powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. We found that almost all quinone molecules encapsulated in the SWCNTs can store Li-ions reversibly. Interestingly, the undesired capacity fading, which comes from the dissolution of quinone molecules into the electrolyte, was suppressed by the encapsulation. It was also found that the overpotential of AQ was decreased by the encapsulation, probably due to the high-electric conductivity of SWCNTs.

  10. Investigation on optical absorption properties of ion irradiated single walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Vishalli,, E-mail: vishalli-2008@yahoo.com; Dharamvir, Keya, E-mail: keya@pu.ac.in [Department of Physics, Panjab University, Chandigarh (India); Kaur, Ramneek; Raina, K. K. [Materials Research Laboratory, School of Physics and Materials Science, Thapar University, Patiala (India); Avasthi, D. K. [Materials Science Group, Inter University Accelerator Centre, ArunaAsaf Ali Marg, NewDelhi (India); Jeet, Kiran [Electron Microscopy and Nanoscience laboratory, Punjab Agriculture University, Ludhiana (India)

    2015-08-28

    In the present study change in the optical absorption properties of single walled carbon nanotubes (SWCNTs) under nickel ion (60 MeV) irradiation at various fluences has been investigated. Langmuir Blodgett technique is used to deposit SWCNT thin film of uniform thickness. AFM analysis shows a network of interconnected bundles of nanotubes. UV-Vis-NIR absorption spectra indicate that the sample mainly contain SWCNTs of semiconducting nature. It has been found in absorption spectra that there is decrease in the intensity of the characteristic SWCNT peaks with increase in fluence. At fluence value 1×10{sup 14} ions/cm{sup 2} there is almost complete suppression of the characteristic SWCNTs peaks.The decrease in the optical absorption with increase in fluence is due to the increase in the disorder in the system which leads to the decrease in optically active states.

  11. Molecular effect on equilibrium charge-state distributions. [of nitrogen ions injected through carbon foil

    Science.gov (United States)

    Wickholm, D.; Bickel, W. S.

    1976-01-01

    The paper describes an experiment consisting of the acceleration of N(+) and N2(+) ions to energies between 0.25 and 1.75 MeV and their injection through a thin carbon foil, whereupon they were charge-state analyzed with an electrostatic analyzer. A foil-covered electrically suppressed Faraday cup, connected to a stepping motor, moved in the plane of the dispersed beams. The Faraday cup current, which was proportional to the number of incident ions, was sent to a current digitizer and computer programmed as a multiscaler. The energy-dependent charge-state fractions, the mean charge and the distribution width were calculated. It was shown that for incident atoms, the charge state distribution appeared to be spread over more charge states, while for the incident molecules, there was a greater fraction of charge states near the mean charge.

  12. Doubly differential cross sections for electron emission in ionization of hydrogen by bare carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Richard, P.; Tribedi, L.; Wang, Y.D.; Ling, D.; Lin, C.D. [and others

    1996-05-01

    The doubly differential cross sections (DDCS) for soft electron emission can provide a stringent test of the theoretical models for ionization in ion-atom collisions. The authors have measured the electron DDCS (d{sup 2}{sigma}/d{epsilon}{sub e}d{Omega}{sub e}) of soft electron emission in the ionization of H{sub 2} bombarded by bare Carbon ions of energy 30 MeV. The energy and angular distribution of the electron DDCS have been carried out for ten different angles ({theta}{sub e}) and for electron energies ({epsilon}{sub e}) varying between 0.1 to 300 eV. The single differential cross sections in terms of electron energy ({epsilon}{sub e}) and angle ({theta}{sub e}) are obtained. The angular distribution is found to peak at {approximately}75{degrees}. The data have been compared to FBA and CDWEIS calculations.

  13. Double differential cross sections for soft electron emission in ionization of hydrogen by bare carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Tribedi, L.C.; Richard, P.; Ling, D.; DePaola, B.; Wang, Y.D.; Lin, C.D. [Kansas State Univ., Manhattan, KS (United States). J.R. MacDonald Lab.; Rudd, M.E. [Nebraska Univ., Lincoln, NE (United States). Dept. of Physics and Astronomy

    1997-12-31

    The double differential cross sections (DDCS) for low energy electron emission can provide stringent tests of the theoretical models for ionization in ion-atom collisions. We have measured the DDCS (d{sup 2}{sigma}/d{Omega} d{epsilon}) of soft electron emission in the ionization of H{sub 2} bombarded by bare Carbon ions of energy 1.84 and 2.5 MeV/u. The measurements have been carried out for different emission angles ({theta}) and for electron energies ({epsilon}) between 0.1 and 300 eV. The angular distributions of the DDCS for electrons with fixed energies were found to peak around 70-75 . The data have been compared with CDW-EIS and FBA calculations. (orig.). 10 refs.

  14. High Voltage Surface Degradation on Carbon Blacks in Lithium Ion Batteries

    DEFF Research Database (Denmark)

    Younesi, Reza

    In order to increase the power density of Li-ion batteries, much research is focused on developing cathode materials that can operate at high voltages above 4.5 V with a high capacity, high cycling stability, and rate capability. However, at high voltages all the components of positive electrodes...... including carbon black (CB) additives have a potential risk of degradation. Though the weight percentage of CB in commercial batteries is generally very small, the volumetric amount and thus the surface area of CB compose a rather large part of a cathode due to its small particle size (≈ 50 nm) and high...... surface area. In this work, the performance of Super P in Li-ion cells at high voltages up to 4.9 V is studied using electrochemical measurements as well as surface characterizations....

  15. X-Ray Absorption in Carbon Ions Near the K-Edge

    Science.gov (United States)

    Hasoglu, M. F.; Abdel-Naby, Sh. A.; Nikolic, D.; Gorczyca, T. W.; McLaughlin, B. M.

    2007-06-01

    K-shell photoabsorption calculations are important for determining the elemental abundances of the interstellar medium (ISM) from observed X-ray absorption spectra. Previously, we performed reliable K-shell photoabsorption calculations for oxygen [1-3] and neon [4,5] ions. We have executed detailed R-matrix calculations for carbon ions, including Auger broadening, by using an optical potential, and relaxation effects, by using pseudoorbitals with the necessary pseudoresonance elimination. This work was funded by NASA's Astronomy Physics Research and Analysis (APRA) and Solar and Heliospheric Physics (SHP) Supporting Research and Technology (SR&T) programs. References: [1] T. W. Gorczyca and B. M. McLaughlin. J Phys. B. 33 L859 (2000) [2] A. M. Juett, et al., Astrophys. J. 612, 308 (2004) [3] J. Garcia et al., Astrophys. J. Supp. S. 158, 68 (2005) [4] T. W. Gorczyca., Phys. Rev. A. 61, 024702 (2000) [5] A. M. Juett, et al., Astrophys. J. 648, 1066 (2006)

  16. Kinetics and thermodynamics studies of silver ions adsorption onto coconut shell activated carbon.

    Science.gov (United States)

    Silva-Medeiros, Flávia V; Consolin-Filho, Nelson; Xavier de Lima, Mateus; Bazzo, Fernando Previato; Barros, Maria Angélica S D; Bergamasco, Rosângela; Tavares, Célia R G

    2016-12-01

    The presence of silver in the natural water environment has been of great concern because of its toxicity, especially when it is in the free ion form (Ag(+)). This paper aims to study the adsorption kinetics of silver ions from an aqueous solution onto coconut shell activated carbon using batch methods. Batch kinetic data were fitted to the first-order model and the pseudo-second-order model, and this last equation fits correctly the experimental data. Equilibrium experiments were carried out at 30°C, 40°C, and 50°C. The adsorption isotherms were reasonably fit using Langmuir model, and the adsorption process was slightly influenced by changes in temperature. Thermodynamic parameters (ΔH°, ΔG°, and ΔS°) were determined. The adsorption process seems to be non-favorable, exothermic, and have an increase in the orderness.

  17. Superhydrophobic to hydrophilic transition of multi-walled carbon nanotubes induced by Na+ ion irradiation

    Science.gov (United States)

    Das, Pritam; Dhal, Satyanarayan; Ghosh, Susanta; Chatterjee, Sriparna; Rout, Chandra S.; Ramgir, Niranjan; Chatterjee, Shyamal

    2017-12-01

    Multi-walled carbon nanotubes (MWCNT) having diameter in the range of 5-30 nm were coated on silicon wafer using spray coating technique. The coated film was irradiated with 5 keV Na+ at a fluence of 1 × 1016 ions·cm-2. A large-scale welding is observed in the post-irradiated nanotube assembly under scanning electron microscope. We have studied dynamic wetting properties of the nanotubes. While the pristine MWCNT shows superhydrophobic nature, the irradiated MWCNT turns into hydrophilic. Our simulation based on iradina and experimental evidences show defect formation in MWCNT due to ion irradiation. We have invoked mechanism based on defect mediated adsorption of water, which plays major role for transition from superhydrophobic to hydrophilic.

  18. Persistent cyclestability of carbon coated Zn–Sn metal oxide/carbon microspheres as highly reversible anode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Fang, Guoqing; Kaneko, Shingo; Liu, Weiwei; Xia, Bingbo; Sun, Hongdan; Zhang, Ruixue; Zheng, Junwei; Li, Decheng

    2013-01-01

    Development of high-capacity anode materials equipped with strong cyclestability is a great challenge for use as practical electrode for high-performance lithium-ion rechargeable battery. In this study, we synthesized a carbon coated Zn–Sn metal nanocomposite oxide and carbon spheres (ZTO@C/CSs) via a simple glucose hydrothermal reaction and subsequent carbonization approach. The carbon coated ZTO/carbon microspheres composite maintained a reversible capacity of 680 mAh g −1 after 345 cycles at a current density of 100 mA g −1 , and furthermore the cell based on the composite exhibited an excellent rate capability of 470 mAh g −1 even when the cell was cycled at 2000 mA g –1 . The thick carbon layer formed on the ZTO nanoparticles and carbon spheres effectively buffered the volumetric change of the particles, which thus prolonged the cycling performance of the electrodes

  19. Phase i study evaluating the treatment of patients with hepatocellular carcinoma (HCC) with carbon ion radiotherapy: the PROMETHEUS-01 trial.

    Science.gov (United States)

    Combs, Stephanie E; Habermehl, Daniel; Ganten, Tom; Schmidt, Jan; Edler, Lutz; Burkholder, Iris; Jäkel, Oliver; Haberer, Thomas; Debus, Jürgen

    2011-02-12

    Treatment options for patients with advanced hepatocellular carcinoma (HCC) are often limited. In most cases, they are not amenable to local therapies including surgery or radiofrequency ablation. The multi-kinase inhibitor sorafenib has shown to increase overall survival in this patient group for about 3 months.Radiation therapy is a treatment alternative, however, high local doses are required for long-term local control. However, due to the relatively low radiation tolerance of liver normal tissue, even using stereotactic techniques, delivery of sufficient doses for successful local tumor control has not be achieved to date.Carbon ions offer physical and biological characteristics. Due to their inverted dose profile and the high local dose deposition within the Bragg peak precise dose application and sparing of normal tissue is possible. Moreover, in comparison to photons, carbon ions offer an increased relative biological effectiveness (RBE), which can be calculated between 2 and 3 depending on the HCC cell line as well as the endpoint analyzed.Japanese Data on the evaluation of carbon ion radiation therapy showed promising results for patients with HCC. In the current Phase I-PROMETHEUS-01-Study, carbon ion radiotherapy will be evaluated for patients with advanced HCC. The study will be performed as a dose-escalation study evaluating the optimal carbon ion dose with respect to toxicity and tumor control.Primary endpoint is toxicity, secondary endpoint is progression-free survival and response. The Prometheus-01 trial ist the first trial evaluating carbon ion radiotherapy delivered by intensity-modulated rasterscanning for the treatment of HCC. Within this Phase I dose escalation study, the optimal dose of carbon ion radiotherapy will be determined. NCT 01167374.

  20. Phase i study evaluating the treatment of patients with hepatocellular carcinoma (HCC with carbon ion radiotherapy: The PROMETHEUS-01 trial

    Directory of Open Access Journals (Sweden)

    Jäkel Oliver

    2011-02-01

    Full Text Available Abstract Background Treatment options for patients with advanced hepatocellular carcinoma (HCC are often limited. In most cases, they are not amenable to local therapies including surgery or radiofrequency ablation. The multi-kinase inhibitor sorafenib has shown to increase overall survival in this patient group for about 3 months. Radiation therapy is a treatment alternative, however, high local doses are required for long-term local control. However, due to the relatively low radiation tolerance of liver normal tissue, even using stereotactic techniques, delivery of sufficient doses for successful local tumor control has not be achieved to date. Carbon ions offer physical and biological characteristics. Due to their inverted dose profile and the high local dose deposition within the Bragg peak precise dose application and sparing of normal tissue is possible. Moreover, in comparison to photons, carbon ions offer an increased relative biological effectiveness (RBE, which can be calculated between 2 and 3 depending on the HCC cell line as well as the endpoint analyzed. Japanese Data on the evaluation of carbon ion radiation therapy showed promising results for patients with HCC. Methods/Design In the current Phase I-PROMETHEUS-01-Study, carbon ion radiotherapy will be evaluated for patients with advanced HCC. The study will be performed as a dose-escalation study evaluating the optimal carbon ion dose with respect to toxicity and tumor control. Primary endpoint is toxicity, secondary endpoint is progression-free survival and response. Discussion The Prometheus-01 trial ist the first trial evaluating carbon ion radiotherapy delivered by intensity-modulated rasterscanning for the treatment of HCC. Within this Phase I dose escalation study, the optimal dose of carbon ion radiotherapy will be determined. Trial registration NCT 01167374

  1. Feasibility of carbon-ion radiotherapy for re-irradiation of locoregionally recurrent, metastatic, or secondary lung tumors.

    Science.gov (United States)

    Hayashi, Kazuhiko; Yamamoto, Naoyoshi; Karube, Masataka; Nakajima, Mio; Tsuji, Hiroshi; Ogawa, Kazuhiko; Kamada, Tadashi

    2018-03-02

    Intrathoracic recurrence after carbon-ion radiotherapy for primary or metastatic lung tumors remains a major cause of cancer-related deaths. However, treatment options are limited. Herein, we report on the toxicity and efficacy of re-irradiation with carbon-ion radiotherapy for locoregionally recurrent, metastatic, or secondary lung tumors. Data of 95 patients with prior intrathoracic carbon-ion radiotherapy who were treated with re-irradiation with carbon-ion radiotherapy at our institution between 2006 and 2016 were retrospectively analyzed. Seventy-three patients (76.8%) had primary lung tumors and 22 patients (23.2%) had metastatic lung tumors. The median dose of initial carbon-ion radiotherapy was 52.8 Gy (relative biological effectiveness) and the median dose of re-irradiation was 66.0 Gy (relative biological effectiveness). None of the patients received concurrent chemotherapy. The median follow-up period after re-irradiation was 18 months. In terms of grade ≥3 toxicities, one patient experienced each of the following: grade 5 bronchopleural fistula, grade 4 radiation pneumonitis, grade 3 chest pain, and grade 3 radiation pneumonitis. The 2-year local control and overall survival rates were 54.0% and 61.9%, respectively. In conclusion, re-irradiation with carbon-ion radiotherapy was associated with relatively low toxicity and moderate efficacy. Re-irradiation with carbon-ion radiotherapy might be an effective treatment option for patients with locoregionally recurrent, metastatic, or secondary lung tumors. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  2. Tumor induction in mice after local irradiation with single doses of either carbon-ion beams or gamma rays.

    Science.gov (United States)

    Ando, Koichi; Koike, Sachiko; Ohmachi, Yasushi; Ando, Yutaka; Kobashi, Gen

    2014-12-01

    To determine the dose-dependent relative biological effectiveness (RBE) for tumor prevalence in mice receiving single localized doses to their right leg of either carbon ions (15, 45 or 75 keV/μm) or 137Cs gamma rays. A total of 1647 female C3H mice were irradiated to their hind legs with a localized dose of either reference gamma rays or 15, 45 or 75 keV/μm carbon-ion beams. Irradiated mice were evaluated for tumors twice a month during their three-year life span, and the dimensions of any tumors found were measured with a caliper. The tumor induction frequency was calculated by Kaplan-Meier analysis. The incidence of tumors from 50 Gy of 45 keV/μm carbon ions was marginally higher than those from 50 Gy of gamma rays. However, 60 Gy of 15 keV/μm carbon ions induced significantly fewer tumors than did gamma rays. RBE values of 0.87 + 0.12, 1.29 + 0.08 or 2.06 + 0.39 for lifetime tumorigenesis were calculated for 15, 45 or 75 keV/μm carbon-ion beams, respectively. Fibrosarcoma predominated, with no Linear Energy Transfer (LET)-dependent differences in the tumor histology. Experiments measuring the late effect of leg skin shrinkage suggested that the carcinogenic damage of 15 keV/μm carbon ions would be less than that of gamma rays. We conclude that patients receiving radiation doses to their normal tissues would face less risk of secondary tumor induction by carbon ions of intermediate LET values compared to equivalent doses of photons.

  3. The effect of carbon impurities on molybdenum surface morphology evolution under high-flux low-energy helium ion irradiation

    International Nuclear Information System (INIS)

    Tripathi, J.K.; Novakowski, T.J.; Gonderman, S.; Bharadwaj, N.; Hassanein, A.

    2016-01-01

    We report on the role of carbon (C) impurities, in molybdenum (Mo) fuzz evolutions on Mo surface during 100 eV He + ion irradiations. In this study we considered 0.01, 0.05, and 0.5% C + ion impurities in He + ion irradiations. For introducing such tiny C + ion impurities, gas mixtures of He and CH 4 have been chosen in following ratios; 99.95: 0.05, 99.75: 0.25, and 97.5: 2.5. Apart from these three cases, two additional cases, 100% He + ion (for Mo fuzz growth due to only He + ions) and 100% H + ion (for confirming the significance of tiny 0.04–2.0% H + ions in terms of Mo fuzz evolutions on Mo surface, if any), have also been considered. Ion energy (100 eV), ion fluence (2.6 × 10 24  ions m −2 ), and target temperature (923 K) were kept constant for each experiment and their selections were based on our previous studies [1,2]. Our study shows homogeneously populated and highly dense Mo fuzz evolutions on entire Mo surface for 100% He + ion irradiation case. Enhancement of C + ion impurities in He + ions causes a sequential reduction in Mo fuzz evolutions, leading to almost complete prevention of Mo fuzz evolutions for 0.5% C + ion impurity concentrations. Additionally, no fuzz formation for 100% H + ion irradiation at all, were seen (apart from some tiny nano-structuring, in very limited regions). This indicates that there is no significant role of H + ions in Mo fuzz evolutions (at least for such tiny amount, 0.04–2.0% H + ions). The study is significant to understand the behavior of potential high-Z plasma facing components (PFCs), in the, presence of tiny amount of C impurities, for nuclear fusion relevant applications. - Highlights: • Mo Fuzz evolutions due to low-energy high-flux 100% He + ion irradiation. • Sequential reduction in Mo fuzz evolutions with increasing C + ion impurities in He + ions. • Almost complete prevention of Mo fuzz evolutions for 0.5% C + ion impurity in He + ions. • No Mo fuzz formation for 100% H + ion

  4. Palladium Nanoparticle Incorporated Porous Activated Carbon: Electrochemical Detection of Toxic Metal Ions.

    Science.gov (United States)

    Veerakumar, Pitchaimani; Veeramani, Vediyappan; Chen, Shen-Ming; Madhu, Rajesh; Liu, Shang-Bin

    2016-01-20

    A facile method has been developed for fabricating selective and sensitive electrochemical sensors for the detection of toxic metal ions, which invokes incorporation of palladium nanoparticles (Pd NPs) on porous activated carbons (PACs). The PACs, which were derived from waste biomass feedstock (fruit peels), possess desirable textural properties and porosities favorable for dispersion of Pd NPs (ca. 3-4 nm) on the graphitic PAC substrate. The Pd/PAC composite materials so fabricated were characterized by a variety of different techniques, such as X-ray diffraction, field-emission transmission electron microscopy, gas physisorption/chemisorption, thermogravimetric analysis, and Raman, Fourier-transform infrared, and X-ray photon spectroscopies. The Pd/PAC-modified glassy carbon electrodes (GCEs) were exploited as electrochemical sensors for the detection of toxic heavy metal ions, viz., Cd(2+), Pb(2+), Cu(2+), and Hg(2+), which showed superior performances for both individual as well as simultaneous detections. For simultaneous detection of Cd(2+), Pb(2+), Cu(2+), and Hg(2+), a linear response in the ion concentration range of 0.5-5.5, 0.5-8.9, 0.5-5.0, and 0.24-7.5 μM, with sensitivity of 66.7, 53.8, 41.1, and 50.3 μA μM(-1) cm(-2), and detection limit of 41, 50, 66, and 54 nM, respectively, was observed. Moreover, the Pd/PAC-modified GCEs also show perspective applications in detection of metal ions in real samples, as illustrated in this study for a milk sample.

  5. High-rate capability silicon decorated vertically aligned carbon nanotubes for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Gohier, Aurelien; Kim, Ki-Hwan; Maurice, Jean-Luc; Cojocaru, Costel Sorin [Laboratoire de Physique des Interfaces et des Couches Minces, LPICM, Ecole Polytechnique, route de Saclay, 91128 Palaiseau Cedex (France); Laik, Barbara; Pereira-Ramos, Jean-Pierre [Institut de Chimie et des Materiaux Paris-Est, ICMPE/GESMAT, UMR 7182 CNRS-UPEC, 2 rue Henri Dunant, 94320 Thiais (France); Van, Pierre Tran [Renault SAS, DREAM/DETA/SEE, 1, avenue du Golf, 78288 Guyancourt (France)

    2012-05-15

    The concept of a hybrid nanostructured collector made of thin vertically aligned carbon nanotubes (CNTs) decorated with Si nanoparticles provides high power density anodes in lithium-ion batteries. An impressive rate capability is achieved due to the efficient electronic conduction of CNTs combined with well defined electroactive Si nanoparticles: capacities of 3000 mAh g{sup -1} at 1.3C and 800 mAh g{sup -1} at 15C are achieved. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. The comparison of calculated and experimental microdosimetric distributions for carbon ions

    Czech Academy of Sciences Publication Activity Database

    Palajová, Zdenka; Spurný, František; Davídková, Marie

    2007-01-01

    Roč. 122, 1-4 (2007), s. 491-493 ISSN 0144-8420. [Symposium on Microdosimetry /14./. Venezia, 13.11.2005-18.11.2005] R&D Projects: GA ČR GA202/04/0795; GA ČR(CZ) GD202/05/H031 Institutional research plan: CEZ:AV0Z10480505 Keywords : microdosimetry distributions * carbon ions * theoretical calculation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.528, year: 2007

  7. FTIR study of carbon monoxide adsorption on ion-exchanged X, Y and mordenite type zeolites

    Directory of Open Access Journals (Sweden)

    R. HERCIGONJA

    2003-05-01

    Full Text Available In this work Fourier transform infrared (FTIR study has been applied to study the adsorption of carbon monoxide on transition metal (Mn+, Co2+, Ni2+ ion-exchanged zeolites type Y, X and mordenites. The adsorption of CO at room temperature produces overlapping IR absorption bands in the 2120–2200 cm-1 region. The frequency of the band around 2200 cm-1 is found to be dependent not only on the charge-balancing transition metal cation, but also on the framework composition. The frequencies of the band near 1600 cm-1 was found to be dependent on the Si/Al ratio of the investigated zeolites.

  8. Phase space generation for proton and carbon ion beams for external users’ applications at the Heidelberg Ion Therapy Center

    Directory of Open Access Journals (Sweden)

    Thomas eTessonnier

    2016-01-01

    Full Text Available In the field of radiation therapy, accurate and robust dose calculation is required. For this purpose, precise modeling of the irradiation system and reliable computational platforms are needed. At the Heidelberg Ion Therapy Center (HIT, the beamline has been already modeled in the FLUKA Monte Carlo code. However, this model was kept confidential for disclosure reasons and was not available for any external team. The main goal of this study was to create efficiently phase space (PS files for proton and carbon ion beams, for all energies and foci available at HIT. PS are representing the characteristics of each particle recorded (charge, mass, energy, coordinates, direction cosines, generation at a certain position along the beam path. In order to achieve this goal, keeping a reasonable data size but maintaining the requested accuracy for the calculation, we developed a new approach of beam PS generation with the Monte-Carlo code FLUKA. The generated PS were obtained using an infinitely narrow beam and recording the desired quantities after the last element of the beamline, with a discrimination of primaries or secondaries. In this way, a unique PS can be used for each energy to accommodate the different foci by combining the narrow-beam scenario with a random sampling of its theoretical Gaussian beam in vacuum. PS can also reproduce the different patterns from the delivery system, when properly combined with the beam scanning information. MC simulations using PS have been compared to simulations including the full beamline geometry and have been found in very good agreement for several cases (depth dose distributions, lateral dose profiles, with relative dose differences below 0.5%. This approach has also been compared with measured data of ion beams with different energies and foci, resulting in a very satisfactory agreement. Hence, the proposed approach was able to fulfill the different requirements and has demonstrated its capability for

  9. Investigation of optical properties of Cu/Ni multilayer nanowires embedded in etched ion-track template

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Lu [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Yao, Huijun, E-mail: Yaohuijun@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Duan, Jinglai; Chen, Yonghui [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Lyu, Shuangbao [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Maaz, Khan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Nanomaterials Research Group, Physics Division, PINSTECH, Nilore 45650, Islamabad (Pakistan); Mo, Dan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, Jie, E-mail: J.Liu@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Sun, Youmei; Hou, Mingdong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-12-01

    Graphical abstract: The schematic diagram of measurement of extinction spectra of Cu/Ni multilayer nanowire arrays embedded in the template after removing the gold/copper substrate. - Highlights: • The optical properties of Cu/Ni multilayer nanowire arrays were first investigated by UV/Vis/NIR spectrometer and it was confirmed that the extinction peaks strongly related to the periodicity of the multilayer nanowire. • The Ni segment was thought as a kind of impurity which can change the surface electron distribution and thereby the extinction peaks of nanowire. • Current work supplied the clear layer thickness information of Cu and Ni in Cu/Ni multilayer nanowire with TEM and EDS line-scan profile analysis. - Abstract: For understanding the interaction between light and noble/magnetism multilayer nanowires, Cu/Ni multilayer nanowires are fabricated by a multi-potential step deposition technique in etched ion-track polycarbonate template. The component and the corresponding layer thickness of multilayer nanowire are confirmed by TEM and EDS line-scan analysis. By tailoring the nanowire diameter, the Cu layer thickness and the periodicity of the nanowire, the extinction spectral of nanowire arrays exhibit an extra sensitivity to the change of structural parameters. The resonance wavelength caused by surface plasmon resonance increases obviously with increasing the nanowire diameter, the Cu layer thickness and the periodicity. The observations in our work can be explained by the “impurity effect” and coupled effect and can also be optimized for developing optical devices based on multilayer nanowires.

  10. Range Measurements of keV Hydrogen Ions in Solid Oxygen and Carbon Monoxide

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.; Andersen, H.H.

    1984-01-01

    Ranges of 1.3–3.5 keV/atom hydrogen and deuterium molecular ions have been measured by a thin-film reflection method. The technique, used here for range measurements in solid oxygen and carbon monoxide targets, is identical to the one used previously for range measurements in hydrogen and nitrogen....... The main aim was to look for phase-effects, i.e. gas-solid differences in the stopping processes. While measured ranges in solid oxygen were in agreement with known gas data, the ranges in solid carbon<