WorldWideScience

Sample records for carbon ion dosimetry

  1. Calculation of stopping power ratios for carbon ion dosimetry

    Science.gov (United States)

    Geithner, Oksana; Andreo, P.; Sobolevsky, N.; Hartmann, G.; Jäkel, O.

    2006-05-01

    Water-to-air stopping power ratio calculations for the ionization chamber dosimetry of clinical carbon ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 was used, which is a newly developed version where substantial modifications were implemented on its predecessor SHIELD-HIT v1 (Gudowska et al 2004 Phys. Med. Biol. 49 1933-58). The code was completely rewritten replacing formerly used single precision variables with double precision variables. The lowest particle transport specific energy was decreased from 1 MeV/u down to 10 keV/u by modifying the Bethe-Bloch formula, thus widening its range for medical dosimetry applications. In addition, the code includes optionally MSTAR and ICRU-73 stopping power data. The fragmentation model was verified and its parameters were also adjusted. The present code version shows excellent agreement with experimental data. It has been used to compute the physical quantities needed for the calculation of stopping power ratios, swater,air, of carbon beams. Compared with the recommended constant value given in the IAEA Code of Practice, the differences found in the present investigations varied between 0.5% and 1% at the plateau region, respectively for 400 MeV/u and 50 MeV/u beams, and up to 2.3% in the vicinity of the Bragg peak for 50 MeV/u.

  2. Ion storage dosimetry

    Science.gov (United States)

    Mathur, V. K.

    2001-09-01

    The availability of a reliable, accurate and cost-effective real-time personnel dosimetry system is fascinating to radiation workers. Electronic dosimeters are contemplated to meet this demand of active dosimetry. The development of direct ion storage (DIS) dosimeters, a member of the electronic dosimeter family, for personnel dosimetry is also an attempt in this direction. DIS dosimeter is a hybrid of the well-established technology of ion chambers and the latest advances in data storage using metal oxide semiconductor field effect transistor (MOSFET) analog memory device. This dosimeter is capable of monitoring legal occupational radiation doses of gamma, X-rays, beta and neutron radiation. Similar to an ion chamber, the performance of the dosimeter for a particular application can be optimized through the selection of appropriate wall materials. The use of the floating gate of a MOSFET as one of the electrodes of the ion chamber allows the miniaturization of the device to the size of a dosimetry badge and avoids the use of power supplies during dose accumulation. The concept of the device, underlying physics and the design of the DIS dosimeter are discussed. The results of preliminary testing of the device are also provided.

  3. Evaluation of plastic materials for range shifting, range compensation, and solid-phantom dosimetry for carbon-ion beams

    CERN Document Server

    Kanematsu, Nobuyuki; Ogata, Risa

    2012-01-01

    Purpose: Beam range control is the essence of radiotherapy with heavy charged particles. In conventional broad-beam delivery, fine range adjustment is achieved by insertion of range shifting and compensating materials. Ideally, such material should be water equivalent as well as that for dosimetry. In this study, we evaluated dosimetric water equivalency of four common plastics, HDPE, PMMA, PET, and POM, by uniformity of effective densities for carbon-ion-beam interactions. Methods: Using the Bethe formula for stopping, the Gottschalk formula for multiple scattering, and the Sihver formula for nuclear interactions, we calculated the effective densities of the plastics for these interactions. We tested HDPE, PMMA, and POM in carbon-ion-beam experiment and measured attenuations of carbon ions, which were compared with empirical linear-attenuation-model calculations. Results: The theoretical calculations resulted in reduced multiple scattering and increased nuclear interactions for HDPE compared to water, which ...

  4. Evaluation of plastic materials for range shifting, range compensation, and solid-phantom dosimetry in carbon-ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kanematsu, Nobuyuki; 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)

    2013-04-15

    Purpose: Beam range control is the essence of radiotherapy with heavy charged particles. In conventional broad-beam delivery, fine range adjustment is achieved by insertion of range shifting and compensating materials. In dosimetry, solid phantoms are often used for convenience. These materials should ideally be equivalent to water. In this study, the authors evaluated dosimetric water equivalence of four common plastics, high-density polyethylene (HDPE), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polyoxymethylene (POM). Methods: Using the Bethe formula for energy loss, the Gottschalk formula for multiple scattering, and the Sihver formula for nuclear interactions, the authors calculated the effective densities of the plastics for these interactions. The authors experimentally measured variation of the Bragg peak of carbon-ion beams by insertion of HDPE, PMMA, and POM, which were compared with analytical model calculations. Results: The theoretical calculation resulted in slightly reduced multiple scattering and severely increased nuclear interactions for HDPE, compared to water and the other plastics. The increase in attenuation of carbon ions for 20-cm range shift was experimentally measured to be 8.9% for HDPE, 2.5% for PMMA, and 0.0% for POM while PET was theoretically estimated to be in between PMMA and POM. The agreement between the measurements and the calculations was about 1% or better. Conclusions: For carbon-ion beams, POM was dosimetrically indistinguishable from water and the best of the plastics examined in this study. The poorest was HDPE, which would reduce the Bragg peak by 0.45% per cm range shift, although with marginal superiority for reduced multiple scattering. Between the two clear plastics, PET would be superior to PMMA in dosimetric water equivalence.

  5. Monte Carlo Simulations on the water-to-air stopping power ratio for carbon ion dosimetry

    DEFF Research Database (Denmark)

    Henkner, Katrin; Bassler, Niels; Sobolevsky, Nikolai;

    2009-01-01

    Many papers discussed the I value for water given by the ICRU, concluding that a value of about 80±2  eV instead of 67.2  eV would reproduce measured ion depth-dose curves. A change in the I value for water would have an effect on the stopping power and, hence, on the water-to-air stopping power ...

  6. Monte Carlo simulations for heavy ion dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Geithner, O.

    2006-07-26

    Water-to-air stopping power ratio (s{sub w,air}) calculations for the ionization chamber dosimetry of clinically relevant ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 was used which is a substantially modified version of its predecessor SHIELD-HIT v1. The code was partially rewritten, replacing formerly used single precision variables with double precision variables. The lowest particle transport specific energy was decreased from 1 MeV/u down to 10 keV/u by modifying the Bethe- Bloch formula, thus widening its range for medical dosimetry applications. Optional MSTAR and ICRU-73 stopping power data were included. The fragmentation model was verified using all available experimental data and some parameters were adjusted. The present code version shows excellent agreement with experimental data. Additional to the calculations of stopping power ratios, s{sub w,air}, the influence of fragments and I-values on s{sub w,air} for carbon ion beams was investigated. The value of s{sub w,air} deviates as much as 2.3% at the Bragg peak from the recommended by TRS-398 constant value of 1.130 for an energy of 50 MeV/u. (orig.)

  7. Recombination characteristics of therapeutic ion beams on ion chamber dosimetry

    Science.gov (United States)

    Matsufuji, Naruhiro; Matsuyama, Tetsuharu; Sato, Shinji; Kohno, Toshiyuki

    2016-09-01

    In heavy ion radiotherapy, ionization chambers are regarded as a standard for determining the absorbed dose given to patients. In ion dosimetry, it is necessary to correct the radiation quality, which depends on the initial recombination effect. This study reveals for the radiation quality dependence of the initial recombination in air in ion dosimetry. Ionization charge was measured for the beams of protons at 40-160 MeV, carbon at 21-400 MeV/n, and iron at 23.5-500 MeV/n using two identical parallel-plate ionization chambers placed in series along the beam axis. The downstream chamber was used as a monitor operated with a constant applied voltage, while the other chamber was used for recombination measurement by changing the voltage. The ratio of the ionization charge measured by the two ionization chambers showed a linear relationship with the inverse of the voltage in the high-voltage region. The initial recombination factor was estimated by extrapolating the obtained linear relationship to infinite voltage. The extent of the initial recombination was found to increase with decreasing incident energy or increasing atomic number of the beam. This behavior can be explained with an amorphous track structure model: the increase of ionization density in the core region of the track due to decreasing kinetic energy or increasing atomic number leads to denser initial ion production and results in a higher recombination probability. For therapeutic carbon ion beams, the extent of the initial recombination was not constant but changed by 0.6% even in the target region. This tendency was quantitatively well reproduced with the track-structure based on the initial recombination model; however, the transitional change in the track structure is considered to play an important role in further understanding of the characteristics of the initial recombination.

  8. 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...

  9. Carbon beam dosimetry using VIP polymer gel and MRI

    DEFF Research Database (Denmark)

    Kantemiris, I; Petrokokkinos, L; Angelopoulos, A;

    2009-01-01

    VIP polymer gel dosimeter was used for Carbon ion beam dosimetry using a 150 MeV/n beam with 10 Gy plateau dose and a SOBP irradiation scheme with 5 Gy Bragg peak dose. The results show a decrease by 8 mm in the expected from Monte Carlo simulation range in water, suggesting that the dosimeter...

  10. Monte Carlo simulations for heavy ion dosimetry

    OpenAIRE

    Geithner, Oksana

    2006-01-01

    Water-to-air stopping power ratio ( ) calculations for the ionization chamber dosimetry of clinically relevant ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 was used which is a substantially modified version of its predecessor SHIELD-HIT v1. The code was partially rewritten, replacing formerly used single precision variables with double precision variabl...

  11. Dosimetry for radiobiological experiments using energetic heavy ions

    International Nuclear Information System (INIS)

    The availability of the Bevalac facility of energetic heavy ions with range greater than the size of small mammals makes possible the determination of the biological effects of relatively well defined high LET, whole body irradiation. With the increasing application of high-energy heavy ions in radiobiology there is a corresponding need to develop reliable techniques of both relative and absolute absorbed dose measurement. This paper describes dosimetry studies by the Health Physics Department of the Lawrence Berkeley Laboratory with activation detectors, ionization chambers, nuclear emulsion, thermoluminescent dosimeters and X-ray film. The application of these techniques to an experiment designed to study the leukemogenic effect of the whole-body irradiation of mice by 250 MeV/amu carbon ions is briefly described. Values of absorbed dose in tissue, obtained during this experiment, with a nitrogen filled ionization chamber and 7LiF thermoluminescent dosimeters are compared and shown to be in good agreement. As a result of this work a value for the average energy to produce an ion pair (W) in nitrogen by 250 MeV/amu 6+C ions of 37 +- eV was determined. Values of the efficiency of 7LiF relative to 60Co γ-rays for ions with dE/dx in the range 110-260 MeV g-1 cm2 are reported

  12. Track detector based dosimetry for therapeutic carbon beams

    CERN Document Server

    Osinga, J -M; Brabcová, K Pachnerová; Akselrod, M S; Jäkel, O; Davídková, M; Greilich, S

    2013-01-01

    The ability of plastic and fluorescent nuclear track detectors (PNTDs and FNTDs) to measure fluence and the linear energy transfer (LET) of clinical carbon ion beams was investigated. We employed coincident measurements with both systems and registered the results at the level of single tracks. Irradiations were performed in the entrance channel of the monoenergetic carbon ion beam covering the therapeutically useful energy range from 80 to 425 MeV/u. About 99 % of all primary particle tracks detected by both detectors were successfully matched, while 1 % of the particles were only detected by the FNTDs because of their superior spatial resolution. We conclude that both PNTDs and FNTDs are suitable for clinical carbon beam dosimetry with a detection efficiency of at least 98.82 % and 99.83 % respectively, if irradiations are performed with low fluence in the entrance channel of the ion beam. Additionally, a relationship between the mean LET as determined with PNTDs and the mean fluorescence amplitude of the p...

  13. Fluence-based dosimetry of proton and heavier ion beams using single track detectors

    Science.gov (United States)

    Klimpki, G.; Mescher, H.; Akselrod, M. S.; Jäkel, O.; Greilich, S.

    2016-02-01

    Due to their superior spatial resolution, small and biocompatible fluorescent nuclear track detectors (FNTDs) open up the possibility of characterizing swift heavy charged particle fields on a single track level. Permanently stored spectroscopic information such as energy deposition and particle field composition is of particular importance in heavy ion radiotherapy, since radiation quality is one of the decisive predictors for clinical outcome. Findings presented within this paper aim towards single track reconstruction and fluence-based dosimetry of proton and heavier ion fields. Three-dimensional information on individual ion trajectories through the detector volume is obtained using fully automated image processing software. Angular distributions of multidirectional fields can be measured accurately within  ±2° uncertainty. This translates into less than 5% overall fluence deviation from the chosen irradiation reference. The combination of single ion tracking with an improved energy loss calibration curve based on 90 FNTD irradiations with protons as well as helium, carbon and oxygen ions enables spectroscopic analysis of a detector irradiated in Bragg peak proximity of a 270 MeV u-1 carbon ion field. Fluence-based dosimetry results agree with treatment planning software reference.

  14. Carbon nanotube dosimetry: from workplace exposure assessment to inhalation toxicology

    OpenAIRE

    Erdely, Aaron; Dahm, Matthew; Chen, Bean T.; Zeidler-Erdely, Patti C.; Fernback, Joseph E.; Birch, M. Eileen; Evans, Douglas E.; Kashon, Michael L; Deddens, James A.; Hulderman, Tracy; Bilgesu, Suzan A; Battelli, Lori; Schwegler-Berry, Diane; Leonard, Howard D.; McKinney, Walter

    2013-01-01

    Background Dosimetry for toxicology studies involving carbon nanotubes (CNT) is challenging because of a lack of detailed occupational exposure assessments. Therefore, exposure assessment findings, measuring the mass concentration of elemental carbon from personal breathing zone (PBZ) samples, from 8 U.S.-based multi-walled CNT (MWCNT) manufacturers and users were extrapolated to results of an inhalation study in mice. Results Upon analysis, an inhalable elemental carbon mass concentration ar...

  15. Twelfth Symposium on Neutron and Ion Dosimetry - NEUDOS-12. Editorial

    International Nuclear Information System (INIS)

    The 12. Neutron and Ion Dosimetry Symposium was hosted by the Institute for Radiological Protection and Nuclear Safety (IRSN), in France, from 3 to 7 June 2013, in co-operation with the European Dosimetry Group (EURADOS). The symposium venue was the Congress Centre in Aix-en-Provence. This 12. edition of the NEUDOS symposium was held in the northern hemisphere, after its original and successful organisation at the i-Themba Laboratory, in South Africa, in 2009. In the past (1995), France had already organised the NEUDOS-8, in Paris, after a series of seven symposia hosted by Germany from 1972 to 1991. Before South Africa, the Netherlands and then Sweden had, respectively, hosted the 9. and 10. editions. Neutron and ion dosimetry is of great importance for radiation protection purposes in various fields of activity and situations, such as the use of accelerators for research and medical applications, the operation of reactors and fuel cycle facilities and activities on-board aircraft leading to exposure to cosmic rays. The general aim of the NEUDOS symposia is to share knowledge, to exchange experience and to promote new ideas in the field of neutron and ion dosimetry, between scientists from research bodies, regulatory authorities and industry worldwide. Organised about every 4 y, this symposium has now become quite popular for a wide dosimetrists community, as is shown by the growing figures of attendance to this week-lasting event. NEUDOS-12 attracted ∼230 participants from 30 countries, from all continents, mainly from Europe (80 %), Asia (13 %) and America (4 %). There were a total of 61 oral presentations, 12 invited and 49 selected among the submitted abstracts. Around 134 posters were presented during two dedicated sessions. Two satellite meetings were held: a meeting related to the results of the EURADOS Intercomparison 2012 for whole-body neutron dosemeters (IC2012n), chaired by Elebna Fantuzzi from the Italian National Agency for New Technologies (ENEA

  16. Carbon Ion Therapy

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, David Christoffer; Herrmann, Rochus;

    On the importance of choice of target size for selective boosting of hypoxic tumor subvolumina in carbon ion therapy Purpose: Functional imaging methods in radiotherapy are maturing and can to some extent uncover radio resistant structures found within a tumour entity. Selective boost of identified...... effect. All cell lines investigated here did not reach an OER of 1, even for the smaller structures, which may indicate that the achievable dose average LET of carbon ions is too low, and heavier ions than carbon may be considered for functional LET-painting....

  17. Dosimetry auditing procedure with alanine dosimeters for light ion beam therapy

    DEFF Research Database (Denmark)

    Ableitinger, Alexander; Vatnitsky, Stanislav; Herrmann, Rochus;

    2013-01-01

    of the biological dose is out of scope of the current work. Materials and methods The audit procedure was based on a homogeneous phantom that mimics the dimension of a head (20 × 20 × 21 cm3). The phantom can be loaded either with an ionisation chamber or 20 alanine dosimeters plus 2 radiochromic EBT films. Dose......Background and purpose In the next few years the number of facilities providing ion beam therapy with scanning beams will increase. An auditing process based on an end-to-end test (including CT imaging, planning and dose delivery) could help new ion therapy centres to validate their entire logistic...... of about 3%. Conclusions Alanine dosimeters are suitable detectors for dosimetry audits in ion beam therapy and the presented end-to-end test is feasible. If further studies show similar results, this dosimetric audit could be implemented as a credentialing procedure for clinical proton and carbon beam...

  18. Dosimetry for ion-beam therapy using fluorescent nuclear track detectors and an automated reader

    CERN Document Server

    Greilich, Steffen; Klimpki, Grischa M; Kouwenberg, Jasper J M; Neuholz, Alexander; Pfeiler, Tina; Rahmanian, Shirin; Stadler, Alexander; Ulrich, Leonie

    2016-01-01

    For the assessment of effects of clinical ion-beams, dosimetry has to be complemented by information on particle-energy distribution or related quantities. Fluorescence nuclear track detectors made from C,Mg-doped alumina single crystals allow for the quantification of ion track density and energy loss on a single-track basis. In this study, their feasibility and accuracy to quantify fluence, linear-energy-transfer (LET) distributions, and eventually dose for a spread-out carbon ion Bragg peak was investigated. We found that while for the primary ions track densities agreed within a percent range with the reference data generated by Monte-Carlo radiation transport, the number of low-LET fragments in the beam was largely underestimated by approximately a factor three - the effect was most pronounced for protons where the measured fluence deviates at least an order of magnitude. Nevertheless, due to the dose major contribution of carbon ions, the determination of the individual detector sensitivity could be ide...

  19. DOSIMETRY

    CERN Multimedia

    2001-01-01

    From the month of May on, the neutron dosimeter will be worn in an extra package distinct from the usual film-badge. We will give you more ample information in Weekly Bulletin No. 18/2001 of April 30, 2001. In the week following Easter (17 - 20. 4. 2001) the Individual Dosimetry Service will be opened in the mornings from 8:30 to 11:30 h only. The Service will be closed on April 30.

  20. Dosimetry auditing procedure with alanine dosimeters for light ion beam therapy

    International Nuclear Information System (INIS)

    Background and purpose: In the next few years the number of facilities providing ion beam therapy with scanning beams will increase. An auditing process based on an end-to-end test (including CT imaging, planning and dose delivery) could help new ion therapy centres to validate their entire logistic chain of radiation delivery. An end-to-end procedure was designed and tested in both scanned proton and carbon ion beams, which may also serve as a dosimetric credentialing procedure for clinical trials in the future. The developed procedure is focused only on physical dose delivery and the validation of the biological dose is out of scope of the current work. Materials and methods: The audit procedure was based on a homogeneous phantom that mimics the dimension of a head (20 × 20 × 21 cm3). The phantom can be loaded either with an ionisation chamber or 20 alanine dosimeters plus 2 radiochromic EBT films. Dose verification aimed at measuring a dose of 10 Gy homogeneously delivered to a virtual-target volume of 8 × 8 × 12 cm3. In order to interpret the readout of the irradiated alanine dosimeters additional Monte Carlo simulations were performed to calculate the energy dependent detector response of the particle fluence in the alanine detector. A pilot run was performed with protons and carbon ions at the Heidelberg Ion Therapy facility (HIT). Results: The mean difference of the absolute physical dose measured with the alanine dosimeters compared with the expected dose from the treatment planning system was −2.4 ± 0.9% (1σ) for protons and −2.2 ± 1.1% (1σ) for carbon ions. The measurements performed with the ionisation chamber indicate this slight underdosage with a dose difference of −1.7% for protons and −1.0% for carbon ions. The profiles measured by radiochromic films showed an acceptable homogeneity of about 3%. Conclusions: Alanine dosimeters are suitable detectors for dosimetry audits in ion beam therapy and the presented end-to-end test is

  1. EPR dosimetry with synthetic A-type carbonated apatite

    International Nuclear Information System (INIS)

    Synthetic A-type carbonated apatite prepared in reproducible conditions were irradiated at room temperature with 60 Co γ rays. The EPR spectrum is associated to axial CO2- and orthorhombic CO3- species. Radicals used as dose marker in biological apatite are long live paramagnetic species. The stability of the post-irradiation signal of A-type apatite was investigated for more than one year. Measurements showed variations in the spectra attributed to unstable CO3- species, which can be eliminated by thermal treatments at 100 deg C for 24 hours. The CO2- spectrum can be identified in samples irradiated up to 0.2 Gy. All results indicate the A-type apatite as an appropriate material for radiotherapy dosimetry. (author)

  2. Reference dosimetry for light-ion beams based on graphite calorimetry.

    Science.gov (United States)

    Rossomme, S; Palmans, H; Thomas, R; Lee, N; Duane, S; Bailey, M; Shipley, D; Bertrand, D; Romano, F; Cirrone, P; Cuttone, G; Vynckier, S

    2014-10-01

    Developments in hadron therapy require efforts to improve the accuracy of the dose delivered to a target volume. Here, the determination of the absorbed dose under reference conditions was analysed. Based on the International Atomic Energy Agency TRS-398 code of practice, for hadron beams, the combined standard uncertainty on absorbed dose to water under reference conditions, derived from ionisation chambers, is too large. This uncertainty is dominated by the beam quality correction factors, [Formula: see text], mainly due to the mean energy to produce one ion pair in air, wair. A method to reduce this uncertainty is to carry out primary dosimetry, using calorimetry. A [Formula: see text]-value can be derived from a direct comparison between calorimetry and ionometry. Here, this comparison is performed using a graphite calorimeter in an 80-MeV A(-1) carbon ion beam. Assuming recommended TRS-398 values of water-to-graphite stopping power ratio and the perturbation factor for an ionisation chamber, preliminary results indicate a wair-value of 35.5 ± 0.9 J C(-1).

  3. Direct ion storage dosimetry systems for photon, beta and neutron radiation with instant readout capabilities

    International Nuclear Information System (INIS)

    The direct ion storage (DIS) dosemeter is a new type of electronic dosemeter from which the dose information for both Hp(10) and Hp(0.07) can be obtained instantly at the workplace by using an electronic reader unit. The number of readouts is unlimited and the stored information is not affected by the readout procedure. The accumulated dose can also be electronically reset by authorised personnel. The DIS dosemeter represents a potential alternative for replacing the existing film and thermoluminescence dosemeters (TLDs) used in occupational monitoring due to its ease of use and low operating costs. The standard version for normal photon and beta dosimetry, as well as a developmental version for neutron dosimetry, have been characterised in several field studies. Two new small size variations are also introduced including a contactless readout device and a militarised version optimised for field use. (author)

  4. Development of ion exchange membrane for possible use in radiation processing dosimetry

    International Nuclear Information System (INIS)

    Gamma radiation-induced polymerization of acrylic acid (AAc) onto polyvinylbutyral (PVB) film has been carried out under nitrogen atmosphere. The grafted film of PVB-g-PAAc was allowed to react with solutions of two ionic dyes (ion exchange), namely brilliant green (BG) or methylene green (MEG). The results show that these new dosimeter films of PVBBG and PVBMEG may be useful for high-dose radiation dosimetry applications. We concluded that, the useful absorbed dose range of the dyed films extends up to about 400 and 300 kGy respectively. (author)

  5. Mobile ions on carbonate surfaces

    Science.gov (United States)

    Kendall, Treavor A.; Martin, Scot T.

    2005-07-01

    Surface ions move during the dissolution and growth of minerals. The present study investigates the density and the mobility of surface ions and the structure of the adsorbed water layer with changes in relative humidity (RH). The time evolution of the polarization force, which is induced by an electrically biased tip of an atomic force microscope, shows that the density and the mobility of surface ions increase with rising humidity, a finding which is consistent with increasing surface hydration. A marked change in the observations above 55% RH indicates a transition from a water layer formed by heteroepitaxial two-dimensional growth at low RH to one formed by multilayer three-dimensional growth at high RH. A comparison of the results of several rhombohedral carbonates ( viz. CaCO 3, FeCO 3, ZnCO 3, MgCO 3, and MnCO 3) shows that a long relaxation time of the polarization force at high RH is predictive of a rapid dissolution rate. This finding is rationalized by long lifetimes in terrace positions and hence greater opportunities for detachment of the ion to aqueous solution (i.e., dissolution). Our findings on the density and the mobility of surface ions therefore help to better constrain mechanistic models of hydration, ion exchange, and dissolution/growth.

  6. Carbon ion radiotherapy for pancreatic cancer

    International Nuclear Information System (INIS)

    The Heavy Ion Medical Accelerator in Chiba (HIMAC) is the world's first heavy ion accelerator complex dedicated to medical use in a hospital environment. Carbon ion therapy offers the potential advantages of improved dose localization and enhanced biological effects. It has been suggested that carbon ion therapy is effective against radioresistant pancreatic cancer. In April 2000, clinical studies examining the treatment of pancreatic cancer with carbon ions were begun at the HIMAC. As of February 2010, 48 patients treated with preoperative carbon ion radiotherapy and 89 patients treated for locally advanced pancreatic cancer were enrolled into the clinical trials. Both protocols are still ongoing. The interim results of these clinical trials suggest that carbon ion radiotherapy provides good local control and offers a survival advantage for patients with otherwise hard to cure pancreatic cancer, without unacceptable morbidity. (author)

  7. Carbon ion radiotherapy for sarcomas

    International Nuclear Information System (INIS)

    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.)

  8. Time-resolved optically stimulated luminescence of Al2O3:C for ion beam therapy dosimetry.

    Science.gov (United States)

    Yukihara, Eduardo G; Doull, Brandon A; Ahmed, Md; Brons, Stephan; Tessonnier, Thomas; Jäkel, Oliver; Greilich, Steffen

    2015-09-01

    The objective of this study was to characterize the time-resolved (TR) optically stimulated luminescence (OSL) from Al2O3:C detectors and investigate methodologies to improve the accuracy of these detectors in ion beam therapy dosimetry, addressing the reduction in relative response to high linear energy transfer (LET) particles common to solid-state detectors. Al2O3:C OSL detectors (OSLDs) were exposed to proton, (4)He, (12)C and (16)O beams in 22 particle/energy combinations and read using a custom-built TR-OSL reader. The OSL response rOSL, relative to (60)Co gamma dose to water, and the ratio between the UV and blue OSL emission bands of Al2O3:C (UV/blue ratio) were determined as a function of the LET. Monte-Carlo simulations with the multi-purpose interaction and transport code FLUKA were used to estimate the absorbed doses and particle energy spectra in the different irradiation conditions. The OSL responses rOSL varied from 0.980 (0.73 keV μm(-1)) to 0.288 (120.8 keV μm(-1)). The OSL UV/blue ratio varied by a factor of two in the investigated LET range, but the variation for (12)C beams was only 11%. OSLDs were also irradiated at different depths of carbon ion spread-out Bragg peaks (SOBPs), where it was shown that doses could be obtained with an accuracy of ± 2.0% at the entrance channel and within the SOBP using correction factors calculated based on the OSL responses obtained in this study. The UV/blue ratio did not allow accurate estimation of the dose-averaged LET for (12)C SOBPs, although the values obtained can be explained with the data obtained in this study and the additional information provided by the Monte-Carlo simulations. The results demonstrate that accurate OSLD dosimetry can be performed in ion beam therapy using appropriate corrections for the OSL response. PMID:26270884

  9. Carbon nanostructures produced through ion irradiation

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Several nanostructures we produced by ion irradiation have been reviewed in this paper. By using ions to irradiate two ultrahigh molecular weight polyethylene targets respectively, it was found that small fullerenes C20 and C26 were grown, adding two members to the fullerene family. Meanwhile, crystalline diamonds also have been produced by Ar+ ions irradiation of graphite. In the experiment of double ions Ni+ and Ar+ irradiation, nanoscale argon bubbles formed. On the other side, when multi-wall carbon nanotubes were irradiated by C+, many MWCNTs evolved to amorphous carbon nanowires and amorphous carbon nanotubes. And there are possible welding in the crossed nanotubes.

  10. The ELIMED transport and dosimetry beamline for laser-driven ion beams

    Science.gov (United States)

    Romano, F.; Schillaci, F.; Cirrone, G. A. P.; Cuttone, G.; Scuderi, V.; Allegra, L.; Amato, A.; Amico, A.; Candiano, G.; De Luca, G.; Gallo, G.; Giordanengo, S.; Guarachi, L. Fanola; Korn, G.; Larosa, G.; Leanza, R.; Manna, R.; Marchese, V.; Marchetto, F.; Margarone, D.; Milluzzo, G.; Petringa, G.; Pipek, J.; Pulvirenti, S.; Rizzo, D.; Sacchi, R.; Salamone, S.; Sedita, M.; Vignati, A.

    2016-09-01

    A growing interest of the scientific community towards multidisciplinary applications of laser-driven beams has led to the development of several projects aiming to demonstrate the possible use of these beams for therapeutic purposes. Nevertheless, laser-accelerated particles differ from the conventional beams typically used for multiscipilinary and medical applications, due to the wide energy spread, the angular divergence and the extremely intense pulses. The peculiarities of optically accelerated beams led to develop new strategies and advanced techniques for transport, diagnostics and dosimetry of the accelerated particles. In this framework, the realization of the ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) beamline, developed by INFN-LNS (Catania, Italy) and that will be installed in 2017 as a part of the ELIMAIA beamline at the ELI-Beamlines (Extreme Light Infrastructure Beamlines) facility in Prague, has the aim to investigate the feasibility of using laser-driven ion beams for multidisciplinary applications. In this contribution, an overview of the beamline along with a detailed description of the main transport elements as well as the detectors composing the final section of the beamline will be presented.

  11. 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.

  12. Dosimetry; La dosimetrie

    Energy Technology Data Exchange (ETDEWEB)

    Le Couteulx, I.; Apretna, D.; Beaugerie, M.F. [Electricite de France (EDF), 75 - Paris (France)] [and others

    2003-07-01

    Eight articles treat the dosimetry. Two articles evaluate the radiation doses in specific cases, dosimetry of patients in radiodiagnosis, three articles are devoted to detectors (neutrons and x and gamma radiations) and a computer code to build up the dosimetry of an accident due to an external exposure. (N.C.)

  13. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Palmans, H. [Ghent Univ. (Belgium). Dept. of Biomedical Physics; Verhaegen, F.

    1995-12-01

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire`s multiple scattering theory and Vavilov`s energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program`s accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented.

  14. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    International Nuclear Information System (INIS)

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire's multiple scattering theory and Vavilov's energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program's accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented

  15. 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

  16. Indications of Carbon Ion Therapy at CNAO

    Science.gov (United States)

    Orecchia, Roberto; Rossi, Sandro; Fossati, Piero

    2009-03-01

    CNAO will be a dual center capable of providing therapeutic beams of protons and carbon ions with maximum energy of 400 MeV/u. At the beginning, it will be equipped with three treatment rooms with fixed horizontal and vertical beam lines. In a subsequent phase, two more rooms with a rotating gantry are foreseen. An active spot scanning dose delivery system will be employed. Initially, 80% of the treatments will be carried out with carbon ions. All patients will be treated within clinical trials to assess carbon ion indications with an evidence-based methodology. Seven disease-specific working groups have been developed: lung tumors, liver tumors, sarcomas, head and neck tumors, central nervous system lesions, eye tumors and pediatric tumors. The last two groups will be treated mainly with protons. In the first phase, CNAO will focus on head and neck cancers, treating inoperable, residual or recurrent malignant salivary gland tumors, mucosal melanoma, adenocarcinoma and unfavorably located SCC (nasal and paranasal sinuses). Carbon ions will be employed as a boost in the treatment of locally advanced, poor prognosis, SCC of the hypopharynx and tongue base. Bone and soft tissue sarcomas of the extremity will be treated with a limb-sparing approach, and trunk sarcomas will be treated with exclusive or post-operative irradiation. Skull base tumors (chordoma and chondrosarcoma), recurrent or malignant meningioma and glial tumors will be treated with carbon ions. After sufficient expertise has been gained in coping with organ motion, CNAO will start treating thoracic and abdominal targets. HCC will be treated in inoperable patients with one or more lesions that can be included in a single CTV. Early stage NSCLC will be treated. In the second phase, two more groups on gynecological malignancies and digestive tumors (esophageal cancer, rectal cancer, pancreatic cancer) will be created.

  17. Carbon-based ion and molecular channels

    Science.gov (United States)

    Sint, Kyaw; Wang, Boyang; Kral, Petr

    2008-03-01

    We design ion and molecular channels based on layered carboneous materials, with chemically-functionalized pore entrances. Our molecular dynamics simulations demonstrate that these ultra-narrow pores, with diameters around 1 nm, are highly selective to the charges and sizes of the passing (Na^+ and Cl^-) ions and short alkanes. We demonstrate that the molecular flows through these pores can be easily controlled by electrical and mechanical means. These artificial pores could be integrated in fluidic nanodevices and lab-on-a-chip techniques with numerous potential applications. [1] Kyaw Sint, Boyang Wang and Petr Kral, submitted. [2] Boyang Wang and Petr Kral, JACS 128, 15984 (2006).

  18. Reactions of carbon cluster ions stored in an RF trap

    International Nuclear Information System (INIS)

    Reactions of carbon cluster ions with O2 were studied by using an RF ion trap in which cluster ions of specific size produced by laser ablation could be stored selectively. Reaction rate constants for positive and negative carbon cluster ions were estimated. In the case of the positive cluster ions, these were consistent with the previous experimental results using FTMS. Negative carbon cluster ions C-n (n=4-8) were much less reactive than positive cluster ions. The CnO- products were seen only in n=4 and 6. (orig.)

  19. Treatment planning system for carbon ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Koyama-Ito, Hiroko [National Inst. of Radiological Sciences, Chiba (Japan)

    2002-06-01

    This paper describes the treatment planning (TP) and its peripheral system for carbon ion therapy that has been developed and in clinical use in recent two years at our institution. A new treatment planning system which is FOCUS customized to our irradiation system will be launched in clinical use soon. A new DICOM based PACS has been developed and in use. Now MRI, PET images are ready to be utilized for patient definition with image fusion functionality of radiotherapy TP. We implemented the exchange functionality of TP data specified by RTOG 3D QA Center in FOCUS, Pinnacle3 and heavy ion TP. Target volume and normal structure contours and dose distributions are exchangeable. A database system of carbon ion therapy dedicated to analysis of therapy data has been designed and implemented. All accessible planning data and treatment records of more than 1000 patients treated for seven and half years have been archived. The system has a DICOM RT sever and a database for miscellaneous text data. Limited numbers of private attributes were introduced for ion therapy specific objects. On-line as well as manual registration along with edit functionalities is prepared. Standard web browser is used to search and retrieve information. A DICOM RT viewer has been developed to view and retrieve RT images, dose distributions and structure set. These system described above are all designed to conform to the up-to-date standards of radiation therapy so as to be bases of the future development of the therapy at our institution. (author)

  20. Clinical advantages of carbon-ion radiotherapy

    Science.gov (United States)

    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

    2008-07-01

    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.

  1. Carbonate Ion Effects on Coccolith Carbon and Oxygen Isotopes

    Science.gov (United States)

    Ziveri, P.; Probert, I.; Stoll, H. M.

    2006-12-01

    conclusively distinguished whether C is taken up only as CO2 by passive diffusion or also by active transport of CO2 or HCO^{3-} . In reality, the patterns of stable isotopic variations in coccoliths may provide more constraints for unraveling the cellular C transport and the calcification mechanisms. We will present latest findings on these issues, both from culture experiments and sediment traps located in the Bay of Bengal. Coccolith species separated from these sediment traps also show evidence of carbonate ion effects.

  2. Carbon Ion Radiotherapy for Skull Base Chordoma

    OpenAIRE

    Mizoe, Jun–etsu; Hasegawa, Azusa; Takagi, Ryo; Bessho, Hiroki; Onda, Takeshi; Tsujii, Hirohiko

    2009-01-01

    Objective: To present the results of the clinical study of carbon ion radiotherapy (CIRT) for skull base and paracervical spine tumors at the National Institute of Radiological Sciences in Chiba, Japan. Methods: The study is comprised of three protocols: a pilot study, a phase I/II dose escalation study, and a phase II study. All the patients were treated by 16 fractions for 4 weeks with total doses of 48.0, 52.8, 57.6, and 60.8 Gy equivalents (GyE). Results: As a result of the dose escalatio...

  3. Dosimetric characterization of a microDiamond detector in clinical scanned carbon ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Marinelli, Marco; Prestopino, G., E-mail: giuseppe.prestopino@uniroma2.it; Verona, C.; Verona-Rinati, G. [INFN—Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata,” Via del Politecnico 1, Roma 00133 (Italy); Ciocca, M.; Mirandola, A.; Mairani, A. [Fondazione CNAO, Strada Campeggi 53, Pavia 27100 (Italy); Raffaele, L. [INFN—Laboratori Nazionali del Sud, Via S. Sofia 62, Catania 95123, Italy and Fondazione CNAO, Strada Campeggi 53, Pavia 27100 (Italy); Magro, G. [INFN—Dipartimento di Fisica, Università degli Studi di Pavia, Via U. Bassi 6, Pavia 27100, Italy and Fondazione CNAO, Strada Campeggi 53, Pavia 27100 (Italy)

    2015-04-15

    direction. A strong distortion in Bragg peak measurement was observed, confirming manufacturer recommendation on avoiding such configuration. Very good results were obtained for SOBP measurements, with a difference below 1% between measured and TPS-calculated doses. The stability of detector sensitivity in the observation period was within the experimental uncertainty. Conclusions: Dosimetric characterization of a PTW microDiamond detector in high-energy scanned carbon ion beams was performed. The results of the present study showed that this detector is suitable for dosimetry of clinical carbon ion beams, with a negligible LET and dose-rate dependence.

  4. 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.

  5. 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.

  6. Shunting arc plasma source for pure carbon ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y. [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2012-02-15

    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{sup 2} at the peak of the pulse.

  7. Shunting arc plasma source for pure carbon ion beama)

    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/mm2 at the peak of the pulse.

  8. 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.

  9. 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. PMID:22380206

  10. TL response of Eu activated LiF nanocubes irradiated by 85 MeV carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Salah, Numan, E-mail: nsalah@kau.edu.sa [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alharbi, Najlaa D. [Sciences Faculty for Girls, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Habib, Sami S. [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Lochab, S.P. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-09-01

    Carbon ions were found to be effective for cancer treatment. These heavy ions have a high relative biological effectiveness compared to those of photons. They have higher linear energy transfer and sharper Bragg peak with a very excellent local tumor control. However, the dose of these swift heavy ions needs to be measured with great accuracy. Lithium fluoride (LiF) is a highly sensitive phosphor widely used for radiation dosimetry. In this work Eu activated LiF nanocubes were exposed to 85 MeV C{sup 6+} ion beam and evaluated for their thermoluminescence (TL) response. Pellet forms of this nanomaterial were exposed to these ions in the fluence range 10{sup 9}–10{sup 13} ions/cm{sup 2}. The obtained result shows a prominent TL glow peak at around 320 °C, which is different than that induced by gamma rays. This glow peak exhibits a linear response in the range 10{sup 9}–10{sup 12} ions/cm{sup 2}, corresponding to the equivalent absorbed doses 0.273–273 kGy. The absorbed doses, penetration depths and main energy loss were calculated using TRIM code based on the Monte Carlo simulation. The supralinearity function and stopping power in this nanomaterial were also studied. The modification induced in the glow curve structure as a result of changing irradiation type might be utilized to use LiF:Eu nanocubes as a dosimeter for mixed filed radiations. Moreover, the wide linear response of LiF:Eu nanocubes along with the low fading are another imperative results suggesting that this nanomaterial might be a good candidate for carbon ions dosimetry.

  11. Intensive irradiation of carbon nanotubes by Si ion beam

    Institute of Scientific and Technical Information of China (English)

    NI Zhichun; LI Qintao; YAN Long; GONG Jinlong; ZHU Dezhang; ZHU Zhiyuan

    2007-01-01

    Multi-walled carbon nanotubes were irradiated with 40 keV Si ion beam to a dose of 1×1017 cm-2. The multiple-way carbon nanowire junctions and the Si doping in carbon nanowires were realized. Moreover, the formation processes of carbon nanowire junctions and the corresponding mechanism were studied.

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

    CERN Document Server

    Pang, Chengguo; 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 accident. The calculated results are compared with other reports. The agreement indicates that this method can be used for treatment plan in heavy ion radiotherapy.

  13. Fiber remote and real time optoelectronic dosimetry based on the optically stimulated luminescence phenomenon: Development of sensors based on aluminium oxide doped with carbon for applications in personal dosimetry

    International Nuclear Information System (INIS)

    An optical fiber sensor based on the use of classical technologies (optoelectronic, laser, optical fibers,...) can be connected to the Optically Stimulated Luminescence properties (or OSL) of the aluminium oxide doped with carbon in order to provide several new capabilities compared to usual dosimeters: remote dose measurements, quasi 'real time' dose measurements, applied to personal dosimetry thanks to a low fading level at room temperature. This thesis work shows the studies about: 1)the state of the art about dosimetry based on the aluminium oxide doped with carbon and its OSL properties (emission and stimulation spectra, glow curves, trap and recombination energy levels,...), 2)the state of the art about international standardization, not only, with regard to personal dosimetry (IEC 61066 Standard) but also to the description of operational quantities called personal dose equivalent Hp(10) and Hp(0,07), 3)the experimental development of a new sensor device based on aluminium oxide crystals (design, realization, tests,...), 4)the application of statistical Monte Carlo calculation methods (code MCNP4B) to the simulation of the sensor head in accordance with the IEC Standard 61066 with regard to the energy and angular response Hp(10). (author)

  14. Evaluation of neutron radiation field in carbon ion therapy

    Science.gov (United States)

    Xu, Jun-Kui; Su, You-Wu; Li, Wu-Yuan; Yan, Wei-Wei; Chen, Xi-Meng; Mao, Wang; Pang, Cheng-Guo

    2016-01-01

    Carbon ions have significant advantages in tumor therapy because of their physical and biological properties. In view of the radiation protection, the safety of patients is the most important issue in therapy processes. Therefore, the effects of the secondary particles produced by the carbon ions in the tumor therapy should be carefully considered, especially for the neutrons. In the present work, the neutron radiation field induced by carbon ions was evaluated by using the FLUKA code. The simulated results of neutron energy spectra and neutron dose was found to be in good agreement with the experiment data. In addition, energy deposition of carbon ions and neutrons in tissue-like media was studied, it is found that the secondary neutron energy deposition is not expected to exceed 1% of the carbon ion energy deposition in a typical treatment.

  15. Radiation dosimetry

    CERN Document Server

    Hine, Gerald J; Hine, Gerald J

    1956-01-01

    Radiation Dosimetry focuses on the advancements, processes, technologies, techniques, and principles involved in radiation dosimetry, including counters and calibration and standardization techniques. The selection first offers information on radiation units and the theory of ionization dosimetry and interaction of radiation with matter. Topics include quantities derivable from roentgens, determination of dose in roentgens, ionization dosimetry of high-energy photons and corpuscular radiations, and heavy charged particles. The text then examines the biological and medical effects of radiation,

  16. The influence of unstable signals for electron spin resonance dosimetry with synthetic A-type carbonated apatite

    International Nuclear Information System (INIS)

    Synthetic A-type carbonated apatite prepared in reproducible conditions was irradiated at room temperature with 60Co gamma rays. The ESR spectrum is associated to axial CO2- and orthorhombic CO3- species. Radicals used as dose markers in biological apatites are long-lived paramagnetic species. The stability of the post-irradiation signal of A-type apatite was investigated for more than one year. Measurements showed variations in the spectra attributed to unstable CO3- species, which can be eliminated by thermal treatments at 100 deg. C for 24 h. The CO2-spectrum can be identified in samples irradiated up to 0.2 Gy. All results indicate that the A-type apatite is an appropriate materials for radiotherapy dosimetry. (author)

  17. Sixth symposium on neutron dosimetry

    International Nuclear Information System (INIS)

    This booklet contains all abstracts of papers presented in 13 sessions. Main topics: Cross sections and Kerma factors; analytical radiobiology; detectors for personnel monitoring; secondary charged particles and microdosimetric basis of q-value for neutrons; personnel dosimetry; concepts for radiation protection; ambient monitoring; TEPC and ion chambers in radiation protection; beam dosimetry; track detectors (CR-39); dosimetry at biomedical irradiation facilities; health physics at therapy facilities; calibration for radiation protection; devices for beam dosimetry (TLD and miscellaneous); therapy and biomedical irradiation facilities; treatment planning. (HP)

  18. Study on dosimetry systems for a few tens MeV/u ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Takuji; Sunaga, Hiromi; Takizawa, Haruki; Tachibana, Hiroyuki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    A combined measurement system consisting of a total calorimeter, a Faraday cup and thin film dosimeters have been developed and tested using a simultaneous irradiation apparatus to measure absorbed dose for a few tens MeV/u ion beams of the TIARA AVF cyclotron. (author)

  19. Making junctions between carbon nanotubes using an ion beam

    CERN Document Server

    Krasheninnikov, A V; Keinonen, J; Banhart, F

    2003-01-01

    Making use of empirical potential molecular dynamics, we study ion bombardment of crossed single-walled carbon nanotubes as a tool to join the nanotubes. We demonstrate that ion irradiation should result in welding of crossed nanotubes, both suspended and deposited on substrates. We further predict optimum ion doses and energies for ion-mediated nanotube welding which may potentially be used for developing complicated networks of joined nanotubes.

  20. Dosimetry Service

    CERN Multimedia

    2006-01-01

    Cern Staff and Users can now consult their dose records for an individual or an organizational unit with HRT. Please see more information on our web page: http://cern.ch/rp-dosimetry Dosimetry Service is open every morning from 8.30 - 12.00. Closed in the afternoons. We would like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCT's) must always be returned to the Service after the use and must not be left on the racks in the experimental areas or in the secretariats. Dosimetry Service Tel. 7 2155 Dosimetry.service@cern.ch http://cern.ch/rp-dosimetry

  1. Electron string ion sources for carbon ion cancer therapy accelerators

    CERN Document Server

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

    2015-01-01

    The Electron String type of Ion Sources (ESIS) was developed, constructed and tested first in the Joint Institute for Nuclear Research. These ion sources can be the appropriate sources for production of pulsed C4+ and C6+ ion beams which can be used for cancer therapy accelerators. In fact the test ESIS Krion-6T already now at the solenoid magnetic field only 4.6 T provides more than 10^10 C4+ ions per pulse and about 5*10^9 C6+ ions per pulse. Such ion sources could be suitable for application at synchrotrons. It was also found, that Krion-6T can provide more than 10^11 C6+ ions per second at 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. As for production of 11C radioactive ion beams ESIS can be the most economic kind of ion source. To proof that the special cryogenic cell for pulse injection of gaseous species into electron string was successfully tested using the ESIS Krion-2M.

  2. Ion implantation inhibits cell attachment to glassy polymeric carbon

    International Nuclear Information System (INIS)

    Implantation of MeV gold, oxygen, carbon ions into GPC alters the surface topography of GPC and enhances the already strong tendency for cells to attach to GPC. We have shown that implantation of silver ions near the surface strongly inhibits cell growth on GPC. Both enhanced adhesion of and inhibition of cell growth are desirable improvements on cardiac implants that have long been successfully fabricated from biocompatible glassy polymeric carbon (GPC). In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that ion beam assisted deposition (IBAD) of silver, as well as silver ion bombardment, can favorably influence the surface of GPC for biomedical applications

  3. Modified carbon black materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Kostecki, Robert; Richardson, Thomas; Boesenberg, Ulrike; Pollak, Elad; Lux, Simon

    2016-06-14

    A lithium (Li) ion battery comprising a cathode, a separator, an organic electrolyte, an anode, and a carbon black conductive additive, wherein the carbon black has been heated treated in a CO.sub.2 gas environment at a temperature range of between 875-925 degrees Celsius for a time range of between 50 to 70 minutes to oxidize the carbon black and reduce an electrochemical reactivity of the carbon black towards the organic electrolyte.

  4. TL Dosimetry on the Tandetron Ion Accelerator area of the ININ

    International Nuclear Information System (INIS)

    For the fulfilment of the operation tests of the Positive Ions type Tandetron 4120 MC, 2 MV, it was obtained the permission consented by the National Commission of Nuclear safety and safeguards (CNSNS). During the stage of tests were arranged Tl dosemeters in the Tandetron Accelerator area, as well as toward to the beam exit. In this work, it was presented the results obtained of the measurement of radiation levels, as much in the area as in the beam exit. This Accelerator is useful in different fields of science such as: biology, radiochemistry, materials, solid state physics, archaeology and environmental sciences between others. (Author)

  5. 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.

  6. Study on neutron radiation field of carbon ions therapy

    CERN Document Server

    Xu, Jun-Kui; Li, Wu-Yuan; Yan, Wei-Wei; Chen, Xi-Meng; Mao, Wang; Pang, Cheng-Guo

    2015-01-01

    Carbon ions offer significant advantages for deep-seated local tumors therapy due to their physical and biological properties. Secondary particles, especially neutrons caused by heavy ion reactions should be carefully considered in treatment process and radiation protection. For radiation protection purposes, the FLUKA Code was used in order to evaluate the radiation field at deep tumor therapy room of HIRFL in this paper. The neutron energy spectra, neutron dose and energy deposition of carbon ion and neutron in tissue-like media was studied for bombardment of solid water target by 430MeV/u C ions. It is found that the calculated neutron dose have a good agreement with the experimental date, and the secondary neutron dose may not exceed one in a thousand of the carbon ions dose at Bragg peak area in tissue-like media.

  7. Field characterization and personal dosimetry at a high energy ion accelerator

    International Nuclear Information System (INIS)

    The response of a variety of dosimeters was evaluated in the radiation field outside the shielding of the Lawrence Berkeley Laboratory Bevalac Biomedical Facility. The primary beam was 580 MeV/center dot/A neon ions, incident upon a 30.5-cm polyethylene cube. The field was characterized by a neutron spectrometer consisting of Bonner spheres and other detectors and by estimates of charged particle fluences in NTA film and in the Berklet spectrometer. The responses of American Acrylics CR-39 track-etch plastic detectors and AECL (Canada) type BD-100 Bubble Detectors were compared to those of NTA film, Andersson-Braun remmeter and recombination-chamber results as well as to reference dose equivalents based upon the unfolded neutron spectrum. Evaluations of these dosimeters are discussed. 7 refs., 4 figs

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

    OpenAIRE

    Cavoto, G.; Cirillo, E. N. M.; Cocina, F.; Ferretti, J.; Polosa, A.D.

    2016-01-01

    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 lo...

  9. The fragment ion distribution of C60 in close collision with fast carbon ions

    International Nuclear Information System (INIS)

    We have measured the mass distribution of fragment ions of C60 produced by collisions with 15.6 MeV carbon ions in different charge states. Close collisions were selectively measured using the coincidence method with the change of the projectile charge state. For the electron capture and loss by C5+.6+ projectile ions, which are the K-electron processes, the multifragmentation was observed evidently. In L-electron loss channels of the C2+ projectile, the peaks of the multiply ionized C60 ions and the multiply ionized fullerene-like fragment ions are more intense or as intense as the small fragment ions. (author)

  10. 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

    Purpose: Compared to photons, using particle radiation in radiotherapy reduces the dose and irradiated volume of normal tissues, potentially reducing side effects. The biological effect of dose deposited by particles such as carbon ions, however, differs from that of dose deposited by photons. The inaccuracy in models to estimate the biological effects of particle radiation remains the most important source of uncertainties in particle therapy. Improving this requires high-precision studies on biological effects of particle radiation. Therefore, the authors aimed to develop a facility for reproducible and high-precision carbon-ion irradiation of cells in culture. The combined dose nonuniformity in the lateral and longitudinal direction should not exceed {+-}1.5%. Dose to the cells from particles than other carbon ions should not exceed 5%. Methods: A uniform lateral dose distribution was realized using a single scatter foil and quadrupole magnets. A modulator wheel was used to create a uniform longitudinal dose distribution. The choice of beam energy and the optimal design of these components was determined using GEANT4 and SRIM Monte Carlo simulations. Verification of the uniformity of the dose distribution was performed using a scintillating screen (lateral) and a water phantom (longitudinal). The reproducibility of dose delivery between experiments was assessed by repeated measurements of the spatial dose distribution. Moreover, the reproducibility of dose-response measurements was tested by measuring the survival of irradiated HEK293 cells in three independent experiments. Results: The relative contribution of dose from nuclear reaction fragments to the sample was found to be <5% when using 90 MeV/u carbon ions. This energy still allows accurate dosimetry conforming to the IAEA Report TRS-398, facilitating comparison to dose-effect data obtained with other radiation qualities. A 1.3 mm long spread-out Bragg peak with a diameter of 30 mm was created, allowing

  11. High temperature annealing studies of strontium ion implanted glassy carbon

    Science.gov (United States)

    Odutemowo, O. S.; Malherbe, J. B.; Prinsloo, L.; Langa, D. F.; Wendler, E.

    2016-03-01

    Glassy carbon samples were implanted with 200 keV strontium ions to a fluence of 2 × 1016 ions/cm2 at room temperature. Analysis with Raman spectroscopy showed that ion bombardment amorphises the glassy carbon structure. Partial recovery of the glassy carbon structure was achieved after the implanted sample was vacuum annealed at 900 °C for 1 h. Annealing the strontium ion bombarded sample at 2000 °C for 5 h resulted in recovery of the glassy carbon substrate with the intensity of the D peak becoming lower than that of the pristine glassy carbon. Rutherford backscattering spectroscopy (RBS) showed that the implanted strontium diffused towards the surface of the glassy carbon after annealing the sample at 900 °C. This diffusion was also accompanied by loss of the implanted strontium. Comparison between the as-implanted and 900 °C depth profiles showed that less than 30% of the strontium was retained in the glassy carbon after heat treatment at 900 °C. The RBS profile after annealing at 2000 °C indicated that no strontium ions were retained after heat treatment at this temperature.

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

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo;

    2011-01-01

    . 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......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...... of the detector geometry implemented in the Monte Carlo simulations....

  13. Study on organosilicon plasma polymers implanted by carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Radeva, E; Yourukova, L; Kolentsov, K; Balabanov, S; Zhechev, D; Steflekova, V [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Amov, B [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria)], E-mail: eradeva@issp.bas.bg

    2008-05-01

    In the present work plasma polymer films obtained from hexamethyldisiloxane have been implanted by carbon ions at three different doses. The photoluminescent properties of the implanted polymers were investigated. The optical transmission of these polymer layers was investigated in the visible spectral region. Their electrical parameters were also measured. It was found that the resulting changes do not worsen the protective properties of the implanted polymer layer. The variations in the properties studied might be ascribed to the nanostructured carbon clusters formed on the polymer surface. The results obtained could form the basis for further optimization of the polymer structure by carbon ion implantation in view of applications in electroluminescent display structures.

  14. Ion-exchange behavior of alkali metals on treated carbons

    International Nuclear Information System (INIS)

    The ion-exchange behavior of trace quantities of the alkali-metal ions sodium and cesium, on activated carbon impregnated with zirconium phosphate (referred to here as ZrP), was studied. Impregnated carbon had twice as much ion-exchange activity as unimpregnated, oxidized carbon, and 10 times as much as commercial activated carbons. The distribution coefficient of sodium increased with increasing pH; the distribution coefficient of cesium decreased with increasing pH. Sodium and cesium were separated with an electrolytic solution of 0.1 M HCl. Preliminary studies indicated that 0.2 M potassium and cesium can also be separated. Distribution coefficients of the supported ZrP were determined by the elution technique and agreed within 20% of the values for pure ZrP calculated from the literature

  15. ESR Dosimetry

    International Nuclear Information System (INIS)

    ESR dosimetry is widely used for several applications such as dose assessment in accidents, medical applications and sterilization of food and other materials. In this work the dosimetric properties of natural and synthetic Hydroxyapatite, Alanine, and 2-Methylalanine are presented. Recent results on the use of a K-Band (24 GHz) ESR spectrometer in dosimetry are also presented

  16. Dosimetry Service

    CERN Multimedia

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 72155 http://cern.ch/rp-dosimetry

  17. Dosimetry Service

    CERN Multimedia

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service Tel. 7 2155 http://cern.ch/rp-dosimetry

  18. Dosimetry Service

    CERN Multimedia

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 7 2155 http://cern.ch/rp-dosimetry

  19. Computational dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Siebert, B.R.L.; Thomas, R.H.

    1996-01-01

    The paper presents a definition of the term ``Computational Dosimetry`` that is interpreted as the sub-discipline of computational physics which is devoted to radiation metrology. It is shown that computational dosimetry is more than a mere collection of computational methods. Computational simulations directed at basic understanding and modelling are important tools provided by computational dosimetry, while another very important application is the support that it can give to the design, optimization and analysis of experiments. However, the primary task of computational dosimetry is to reduce the variance in the determination of absorbed dose (and its related quantities), for example in the disciplines of radiological protection and radiation therapy. In this paper emphasis is given to the discussion of potential pitfalls in the applications of computational dosimetry and recommendations are given for their avoidance. The need for comparison of calculated and experimental data whenever possible is strongly stressed.

  20. Single-ion adsorption and switching in carbon nanotubes

    Science.gov (United States)

    Bushmaker, Adam W.; Oklejas, Vanessa; Walker, Don; Hopkins, Alan R.; Chen, Jihan; Cronin, Stephen B.

    2016-01-01

    Single-ion detection has, for many years, been the domain of large devices such as the Geiger counter, and studies on interactions of ionized gasses with materials have been limited to large systems. To date, there have been no reports on single gaseous ion interaction with microelectronic devices, and single neutral atom detection techniques have shown only small, barely detectable responses. Here we report the observation of single gaseous ion adsorption on individual carbon nanotubes (CNTs), which, because of the severely restricted one-dimensional current path, experience discrete, quantized resistance increases of over two orders of magnitude. Only positive ions cause changes, by the mechanism of ion potential-induced carrier depletion, which is supported by density functional and Landauer transport theory. Our observations reveal a new single-ion/CNT heterostructure with novel electronic properties, and demonstrate that as electronics are ultimately scaled towards the one-dimensional limit, atomic-scale effects become increasingly important.

  1. Characterization of silicates and calcium carbonates applied to high-dose dosimetry

    International Nuclear Information System (INIS)

    The predominant isomorphous form in the biominerals studied in this work (oyster shell, coral, mother of pearl and shell) was aragonite. The appearance of the calcite phase occurred at 500 deg C at a heating rate of 10 deg C/s for all samples except for the coral sample, which was 400 deg C, independent of the heating rate. The most abundant element in the biominerals samples was Ca in the CaO form, and in the silicates (tremolite, diopside and rhodonite) Si in the SiO form. The most common trace element observed in the biominerals samples was Fe. The analyses of electron paramagnetic resonance showed lines of Mn2+ in the coral and mother-of-pearl samples before irradiation. In the case of the irradiated samples, the defects found were CO2-, CO33-, CO3- and SO2-, in the g range between 2.0010 and 2.0062. In the analyses by optical absorption of biominerals, transitions due to the presence of Mn in the samples were found. A thermoluminescent (TL) peak at approximately 140 deg C was found for the biominerals and at 180 deg C for silicates, which intensity depends directly on the dose. For samples exposed to different types of radiation, the TL peak occurred at lower temperatures. From the dose-response curves obtained for these materials, it was possible to determine a linear range for which their application in high dose dosimetry becomes possible. Taking into account the radiation type, among biominerals and silicates, the lowest detectable dose (40mGy) to gamma radiation was achieved for oyster shell samples using the measuring technique of optically stimulated luminescence (OSL). Using beta radiation, for diopside and tremolite samples the lowest detectable dose of 60mGy was obtained. For all samples, using the TL, OSL and thermally stimulated exoelectron emission (TSEE) techniques in alpha, beta and gamma radiation beans a good response reproducibility was obtained. Therefore, the samples characterized in this work are suitable to be used as high dose detectors

  2. Cross sections for bare and dressed carbon ions in water and neon.

    Science.gov (United States)

    Liamsuwan, Thiansin; Nikjoo, Hooshang

    2013-02-01

    than the other calculations at lower energies. The discrepancy arises from the inclusion of all carbon charge states and coupling between electron capture and target ionization channels, while other models use an average projectile charge. The CTMC model presented here provides a tool for cross section calculations for low and intermediate energy carbon projectiles. The calculated cross sections are required for Monte Carlo track structure simulations of full-slowing-down tracks of carbon ions. The work paves the way for biophysical studies and dosimetry at the cellular and subcellular levels in the Bragg peak area of a therapeutic carbon ion beam.

  3. Cross sections for bare and dressed carbon ions in water and neon

    Science.gov (United States)

    Liamsuwan, Thiansin; Nikjoo, Hooshang

    2013-02-01

    other calculations at lower energies. The discrepancy arises from the inclusion of all carbon charge states and coupling between electron capture and target ionization channels, while other models use an average projectile charge. The CTMC model presented here provides a tool for cross section calculations for low and intermediate energy carbon projectiles. The calculated cross sections are required for Monte Carlo track structure simulations of full-slowing-down tracks of carbon ions. The work paves the way for biophysical studies and dosimetry at the cellular and subcellular levels in the Bragg peak area of a therapeutic carbon ion beam.

  4. Response of SOI image sensor to therapeutic carbon ion beam

    CERN Document Server

    Matsumura, Akihiko

    2015-01-01

    Carbon ion radiotherapy is known as a less invasive cancer treatment. The radiation quality is an important parameter to evaluate the biological effect and the clinical dose from the measured physical dose. The performance of SOPHIAS detector, which is the SOI image sensor having a wide dynamic range and large active area, was tested by using therapeutic carbon ion beam at Gunma University Heavy Ion Medical Center (GHMC). It was shown that the primary carbon and secondary particles can be distinguishable by SOPHIAS detector. On the other hand, a LET dependence was observed especially at the high LET region. This phenomenon will be studied by using the device simulator together with Monte Carlo simulation.

  5. Carbon stripper foils for high current heavy ion operation

    International Nuclear Information System (INIS)

    For the proposed new heavy ion linac'at'GSI the installation of a carbon foil stripper section is under discussion. High duty factor as well as high current (but low duty factor) heavy ion beams were used for machine experiments. Long term tests were performed to check the carbon foil durability. Relevant beam parameters have been measured in three measurement campaigns. After beam testing stripper foils were analyzed with different offline methods. Additionally promising results of high current beam irradiation of rotating target wheels will be presented. In the transfer line to the SIS 18 the heavy ion beam is stripped to higher charge states in a thick carbon foil. The stripper foil is loaded with 3 % of the beam power. To avoid evaporation in a single beam pulse, the beam is rapidly swept over its width. Experiences collected during the last decade of foil stripper operation at GSI will be presented. (author)

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

    CERN Document Server

    Salonen, E; 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.

  7. Activated carbon is an electron-conducting amphoteric ion adsorbent

    OpenAIRE

    Biesheuvel, P. M.

    2015-01-01

    Electrodes composed of activated carbon (AC) particles can desalinate water by ion electrosorption. To describe ion electrosorption mathematically, accurate models are required for the structure of the electrical double layers (EDLs) that form within electrically charged AC micropores. To account for salt adsorption also in uncharged ACs, an "attraction term" was introduced in modified Donnan models for the EDL structure in ACs. Here it will be shown how instead of using an attraction term, c...

  8. 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.

  9. Small SRS photon field profile dosimetry performed using a PinPoint air ion chamber, a diamond detector, a novel silicon-diode array (DOSI), and polymer gel dosimetry. Analysis and intercomparison.

    Science.gov (United States)

    Pappas, E; Maris, T G; Zacharopoulou, F; Papadakis, A; Manolopoulos, S; Green, S; Wojnecki, C

    2008-10-01

    Small photon fields are increasingly used in modern radiotherapy and especially in IMRT and SRS/SRT treatments. The uncertainties related to small field profile measurements can introduce significant systematic errors to the overall treatment process. These measurements are challenging mainly due to the absence of charged particle equilibrium conditions, detector size and composition effects, and positioning problems. In this work four different dosimetric methods have been used to measure the profiles of three small 6 MV circular fields having diameters of 7.5, 15.0, and 30.0 mm: a small sensitive volume air ion chamber, a diamond detector, a novel silicon-diode array (DOSI), and vinyl-pyrrolidone based polymer gel dosimeter. The results of this work support the validity of previous findings, suggesting that (a) air ion chambers are not suitable for small field dosimetry since they result in penumbra broadening and require significant corrections due to severe charged particle transport alterations; (b) diamond detectors provide high resolution and rather accurate small field profile measurements, as long as positioning problems can be addressed and the necessary dose rate corrections are correctly applied; and (c) the novel silicon-diode array (DOSI) used in this study seems to be adequate for small field profile measurements overcoming positioning problems. Polymer gel data were assumed as reference data to which the other measurement data were compared both qualitatively and quantitatively using the gamma-index concept. Polymer gels are both phantom and dosimeter, hence there are no beam perturbation effects. In addition, polymer gels are tissue equivalent and can provide high-spatial density and high-spatial resolution measurements without positioning problems, which makes them useful for small field dosimetry measurements. This work emphasizes the need to perform beam profile measurements of small fields (for acceptance, commissioning, treatment planning

  10. Dosimetry Service

    CERN Multimedia

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once every month. A regular read-out is indispensable to ensure periodic monitoring of your personal dose. You must read your dosimeter even if you have not visited the controlled areas. Film badges are no longer valid at CERN and holders of film badges are no longer allowed to enter the controlled radiation areas or work with a source. Dosimetry Service Tel. 72155 http://cern.ch/rp-dosimetry

  11. Dosimetry methods

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, A.; Kovacs, A.;

    2003-01-01

    Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application.......Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application....

  12. Cost-effective pediatric head and body phantoms for computed tomography dosimetry and its evaluation using pencil ion chamber and CT dose profiler

    Directory of Open Access Journals (Sweden)

    A Saravanakumar

    2015-01-01

    Full Text Available In the present work, a pediatric head and body phantom was fabricated using polymethyl methacrylate (PMMA at a low cost when compared to commercially available phantoms for the purpose of computed tomography (CT dosimetry. The dimensions of head and body phantoms were 10 cm diameter, 15 cm length and 16 cm diameter, 15 cm length, respectively. The dose from a 128-slice CT machine received by the head and body phantom at the center and periphery were measured using a 100 mm pencil ion chamber and 150 mm CT dose profiler (CTDP. Using these values, the weighted computed tomography dose index (CTDIw and in turn the volumetric CTDI (CTDIv were calculated for various combinations of tube voltage and current-time product. A similar study was carried out using standard calibrated phantom and the results have been compared with the fabricated ones to ascertain that the performance of the latter is equivalent to that of the former. Finally, CTDIv measured using fabricated and standard phantoms were compared with respective values displayed on the console. The difference between the values was well within the limits specified by Atomic Energy Regulatory Board (AERB, India. These results indicate that the cost-effective pediatric phantom can be employed for CT dosimetry.

  13. Development and characterization of a 2D scintillation detector for quality assurance in scanned carbon ion beams

    Science.gov (United States)

    Tamborini, A.; Raffaele, L.; Mirandola, A.; Molinelli, S.; Viviani, C.; Spampinato, S.; Ciocca, M.

    2016-04-01

    At the Centro Nazionale di Adroterapia Oncologica (CNAO Foundation), a two-dimensional high resolution scintillating dosimetry system has been developed and tested for daily Quality Assurance measurements (QA) in carbon ion radiotherapy with active scanning technique, for both single pencil beams and scanned fields produced by a synchrotron accelerator. The detector consists of a thin plane organic scintillator (25×25 cm2, 2 mm thick) coupled with a high spatial resolution CCD camera (0.25 mm) in a light-tight box. A dedicated Labview software was developed for image acquisition triggered with the beam extraction, data post-processing and analysis. The scintillator system was preliminary characterized in terms of short-term reproducibility (found to be within±0.5%), linearity with the number of particles (linear fit χ2 = 0.996) and dependence on particle flux (measured to be < 1.5 %). The detector was then tested for single beam spot measurements (Full Width at Half Maximum and position) and for 6×6 cm2 reference scanned field (determination of homogeneity) for carbon ions with energy from 115 MeV/u up to 400 MeV/u. No major differences in the investigated beam parameters measured with scintillator system and the radiochromic EBT3 reference films were observed. The system allows therefore real-time monitoring of the carbon ion beam relevant parameters, with a significant daily time saving with respect to films currently used. The results of this study show the suitability of the scintillation detector for daily QA in a carbon ion facility with an active beam delivery system.

  14. 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.

  15. 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

  16. Ion chromatography detection of fluoride in calcium carbonate.

    Science.gov (United States)

    Lefler, Jamie E; Ivey, Michelle M

    2011-09-01

    Fluoride in aquatic systems is increasing due to anthropogenic pollution, but little is known about how this fluoride affects organisms that live in and around aquatic habitats. Fluoride can bioaccumulate in structures comprised of calcium carbonate, such as shells and skeletons of both freshwater and saltwater species as diverse as snails, corals, and coccolithophorid algae. In this article, ion chromatography (IC) techniques are developed to detect and quantify fluoride in a matrix of calcium carbonate. Solid samples are dissolved in hydrochloric acid, pretreated to remove the majority of the chloride ions, and then analyzed using IC. With these methods, the 3σ limit of detection is 0.2 mg of fluoride/kg of calcium carbonate. PMID:21859530

  17. Development of C{sup 6+} laser ion source and RFQ linac for carbon ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sako, T., E-mail: takayuki1.sako@toshiba.co.jp; Yamaguchi, A.; Sato, K. [Toshiba Corporation, Yokohama 235-8522 (Japan); Goto, A.; Iwai, T.; Nayuki, T.; Nemoto, K.; Kayama, T. [Cancer Research Center, Yamagata University Faculty of Medicine, Yamagata 990-9585 (Japan); Takeuchi, T. [Accelerator Engineering Corporation, Chiba 263-0043 (Japan)

    2016-02-15

    A prototype C{sup 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.

  18. 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.

  19. 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. PMID:26932119

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

    Energy Technology Data Exchange (ETDEWEB)

    Cavoto, G. [INFN Sezione di Roma, Rome (Italy); Cirillo, E.N.M. [Sapienza Universita di Roma, Dipartimento SBAI, Rome (Italy); Cocina, F. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); Ferretti, J. [Sapienza Universita di Roma, Dipartimento di Fisica (Italy); INFN Sezione di Roma, Rome (Italy); Polosa, A.D. [Sapienza Universita di Roma, Dipartimento di Fisica (Italy); CERN, Theory Division, Geneva (Switzerland); INFN Sezione di Roma, Rome (Italy)

    2016-06-15

    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 (∼ 11 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 respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the target channeling efficiency. (orig.)

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

    Science.gov (United States)

    Cavoto, G.; Cirillo, E. N. M.; Cocina, F.; Ferretti, J.; Polosa, A. D.

    2016-06-01

    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 (≈ 11 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 respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the target channeling efficiency.

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

    CERN Document Server

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

    2016-01-01

    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 ...

  3. Gated ion transport through dense carbon nanotube membranes.

    Science.gov (United States)

    Yu, Miao; Funke, Hans H; Falconer, John L; Noble, Richard D

    2010-06-23

    Gated ion diffusion is found widely in hydrophobic biological nanopores, upon changes in ligand binding, temperature, transmembrane voltage, and mechanical stress. Because water is the main media for ion diffusion in these hydrophobic biological pores, ion diffusion behavior through these nanochannels is expected to be influenced significantly when water wettability in hydrophobic biological nanopores is sensitive and changes upon small external changes. Here, we report for the first time that ion diffusion through highly hydrophobic nanopores (approximately 3 nm) showed a gated behavior due to change of water wettability on hydrophobic surface upon small temperature change or ultrasound. Dense carbon nanotube (CNT) membranes with both 3-nm CNTs and 3-nm interstitial pores were prepared by a solvent evaporation process and used as a model system to investigate ion diffusion behavior. Ion diffusion through these membranes exhibited a gated behavior. The ion flux was turned on and off, apparently because the water wettability of CNTs changed. At 298 K, ion diffusion through dense CNT membranes stopped after a few hours, but it dramatically increased when the temperature was increased 20 K or the membrane was subjected to ultrasound. Likewise, water adsorption on dense CNT membranes increased dramatically at a water activity of 0.53 when the temperature increased from 293 to 306 K, indicating capillary condensation. Water adsorption isotherms of dense CNT membranes suggest that the adsorbed water forms a discontinuous phase at 293 K, but it probably forms a continuous layer, probably in the interstitial CNT regions, at higher temperatures. When the ion diffusion channel was opened by a temperature increase or ultrasound, ions diffused through the CNT membranes at a rate similar to bulk diffusion in water. This finding may have implications for using CNT membrane for desalination and water treatment. PMID:20504021

  4. Dosimetry standards

    International Nuclear Information System (INIS)

    The following leaflets are contained in this folder concerning the National Physical Laboratory's measurement services available in relation to dosimetry standards: Primary standards of X-ray exposure and X-ray irradiation facilities, X-ray dosimetry at therapy levels, Protection-level X-ray calibrations, Therapy-level gamma-ray facility, Fricke dosemeter reference service, Low-dose-rate gamma-ray facility, Penetrameter and kV meter calibration, Measurement services for radiation processing, Dichromate dosemeter reference service, Electron linear accelerator. (U.K.)

  5. Three dimensional reconstruction of therapeutic carbon ion beams in phantoms using single secondary ion tracks

    CERN Document Server

    Reinhart, Anna Merle; Jakubek, Jan; Martisikova, Maria

    2016-01-01

    Carbon ion beam radiotherapy enables a very localised dose deposition. However, already small changes in the patient geometry or positioning errors can significantly distort the dose distribution. A live monitoring system of the beam delivery within the patient is therefore highly desirable and could improve patient treatment. We present a novel three-dimensional imaging method of the beam in the irradiated object, exploiting the measured tracks of single secondary ions emerging under irradiation. The secondary particle tracks are detected with a TimePix stack, a set of parallel pixelated semiconductor detectors. We developed a three-dimensional reconstruction algorithm based on maximum likelihood expectation maximisation. We demonstrate the applicability of the new method in an irradiation of a cylindrical PMMA phantom of human head size with a carbon ion pencil beam of 226MeV/u. The beam image in the phantom is reconstructed from a set of 9 discrete detector positions between -80 and 50 degrees from the bea...

  6. Precise measurement of prompt photon emission for carbon ion therapy

    CERN Document Server

    Agodi, C; Cirrone, G A P; Collamati, F; Cuttone, G; De Lucia, E; De Napoli, M; Di Domenico, A; Faccini, R; Ferroni, F; Fiore, S; Gauzzi, P; Iarocci, E; Marafini, M; Mattei, I; Paoloni, A; Patera, V; Piersanti, L; Romano, F; Sarti, A; Sciubba, A; Voena, C

    2011-01-01

    Proton and carbon ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments is still a matter of research. A possible technique exploits the information provided by single photon emission from nuclear decays induced by the irradiation. This paper reports the measurements of the spectrum and rate of such photons produced from the interaction of a 80 MeV/u fully stripped carbon ion beam at the Laboratori Nazionali del Sud of INFN, Catania, with a Poly-methyl methacrylate target. The differential production rate for photons with energy E > 2 MeV and emitted at 90 degree is found to be $dN_{\\gamma}/(dN_C d\\Omega)=(2.92\\pm 0.19)\\times 10^{-2}$sr$^{-1}$.

  7. (Biological dosimetry)

    Energy Technology Data Exchange (ETDEWEB)

    Preston, R.J.

    1990-12-17

    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  8. Kinetics of ion beam deposition of carbon at room temperature

    International Nuclear Information System (INIS)

    Growth rates of carbon films grown by ion beam deposition using methane gas were measured in situ as a function of deposition conditions. The methane pressure dependence of the growth rate was used to measure the cross-section for charge exchange. Variations in deposition rate per incident energetic particle found for each ion energy were related to ion current density. It was found that rates of growth per incident energetic specie were (i) largest for the smallest current densities, (ii) decreased monotonically with increasing current density, and (iii) were consistently larger than can be explained by deposition directly from the energetic flux alone. These observations were interpreted in terms of irradiation-induced surface interactions which promote chemisorption of methane physisorbed from the ambient atmosphere. (orig.)

  9. Biological systems: from water radiolysis to carbon ion radiotherapy

    Science.gov (United States)

    Beuve, Michael; Moreau, Jean-Michel; Rodriguez, Claire; Testa, Etienne

    2015-07-01

    Hadron therapy is an innovative cancer treatment method based on the acceleration of light ions at high energy. In addition to their interesting profile of dose deposition, which ensures accurate targeting of localized tumors, carbon ions offer biological properties that lead to an efficient treatment for radio- and chemo-resistant tumors and to provide a boost for tumors in hypoxia. This paper is a short review of the progress in theoretical, experimental, fundamental and applied research, aiming at understanding the origin of the biological benefits of light ions better. As a limit of such a vast and multidisciplinary domain, this review adopts the point of view of the physicists, leaning on results obtained in connection with CIMAP's IRRABAT platform.

  10. Alanine Radiation Detectors in Therapeutic Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo;

    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...... been simulated with FLUKA. We found an agreement between measured values of the relative efficiency with values predicted by the Hansen and Olsen model with divergence less than 4%. With the implementation in FLUKA we are able to simulate the detector response in the depth dose curves with precisions...

  11. Activated carbon is an electron-conducting amphoteric ion adsorbent

    CERN Document Server

    Biesheuvel, P M

    2015-01-01

    Electrodes composed of activated carbon (AC) particles can desalinate water by ion electrosorption. To describe ion electrosorption mathematically, accurate models are required for the structure of the electrical double layers (EDLs) that form within electrically charged AC micropores. To account for salt adsorption also in uncharged ACs, an "attraction term" was introduced in modified Donnan models for the EDL structure in ACs. Here it will be shown how instead of using an attraction term, chemical information of the surface structure of the carbon-water interface in ACs can be used to construct an alternative EDL model for ACs. This EDL model assumes that ACs contain both acidic groups, for instance due to carboxylic functionalities, and basic groups, due to the adsorption of protons to the carbon basal planes. As will be shown, this "amphoteric Donnan" model accurately describes various data sets for ion electrosorption in ACs, for solutions of NaCl, of CaCl2, and mixtures thereof, as function of the exter...

  12. Neutron imaging of ion transport in mesoporous carbon materials.

    Science.gov (United States)

    Sharma, Ketki; Bilheux, Hassina Z; Walker, Lakeisha M H; Voisin, Sophie; Mayes, Richard T; Kiggans, Jim O; Yiacoumi, Sotira; DePaoli, David W; Dai, Sheng; Tsouris, Costas

    2013-07-28

    Neutron imaging is presented as a tool for quantifying the diffusion of ions inside porous materials, such as carbon electrodes used in the desalination process via capacitive deionization and in electrochemical energy-storage devices. Monolithic mesoporous carbon electrodes of ∼10 nm pore size were synthesized based on a soft-template method. The electrodes were used with an aqueous solution of gadolinium nitrate in an electrochemical flow-through cell designed for neutron imaging studies. Sequences of neutron images were obtained under various conditions of applied potential between the electrodes. The images revealed information on the direction and magnitude of ion transport within the electrodes. From the time-dependent concentration profiles inside the electrodes, the average value of the effective diffusion coefficient for gadolinium ions was estimated to be 2.09 ± 0.17 × 10(-11) m(2) s(-1) at 0 V and 1.42 ± 0.06 × 10(-10) m(2) s(-1) at 1.2 V. The values of the effective diffusion coefficient obtained from neutron imaging experiments can be used to evaluate model predictions of the ion transport rate in capacitive deionization and electrochemical energy-storage devices. PMID:23756558

  13. Experimental study of the water-to-air stopping power ratio of monoenergetic carbon ion beams for particle therapy

    Science.gov (United States)

    Sánchez-Parcerisa, D.; Gemmel, A.; Jäkel, O.; Parodi, K.; Rietzel, E.

    2012-06-01

    Reference dosimetry with ionization chambers requires a number of chamber-specific and beam-specific calibration factors. For carbon ion beams, IAEA report TRS-398 yields a total uncertainty of 3% in the determination of the absorbed dose to water, for which the biggest contribution arises from the water-to-air stopping power ratio (sw, air), with an uncertainty of 2%. The variation of (sw, air) along the treatment field has been studied in several Monte Carlo works presented over the last few years. Their results were, in all cases, strongly dependent on the choice of mean ionization potentials (I-values) for air and water. A smaller dependence of (sw, air) with penetration depth was observed. Since a consensus on Iw, air and Iair has not yet been reached, the validity of such studies for clinical use cannot be assessed independently. Our approach is based on a direct experimental measurement of water-equivalent thicknesses of different air gaps at different beam energies. A theoretical expression describing the variation of the stopping power ratio with kinetic energy, sw,air(E), was derived from the Bethe-Bloch formula and fit to the measured data, yielding a coherent pair of Iw and Iair values with Iair/Iw = 1.157 ± 0.023. Additionally, the data from five different beam energies were combined in an average value of sw,air = 1.132 ± 0.003 (statistical) ± 0.003 (variation over energy range), valid for monoenergetic carbon ion beams at the plateau area of the depth dose distribution. A detailed uncertainty analysis was performed on the data, in order to assess the limitations of the method, yielding an overall standard uncertainty below 1% in sw,air(E). Therefore, when properly combined with the appropriate models for the fragment spectra, our experimental work can contribute to narrow the uncertainty margins currently in use in absorbed dose to water determination for dosimetry of carbon ion beam radiotherapy.

  14. Synthesis of amorphous carbon nitride by ion implantation

    Institute of Scientific and Technical Information of China (English)

    ChenZ.; OlofinjanaA.; BellJ

    2001-01-01

    N2+ were implanted into diamondlike carbon (DLC) films in an attempt to synthesizeamorphous carbon nitride. The DLC films were previously deposited on steel substrate by using anion beam sputtering deposition (IBSD) where a single Kaufman type ion gun with argon sourcewas used to sputter a graphite target and simultaneously bombard the growing film. Parallel to theion implantation route, amorphous carbon nitride films were also synthesized by directly using thereactive ion beam sputtering deposition (RIBSD) with nitrogen source to incorporate nitrogen intothe film. The structure and properties of the films were determined by using Raman spectroscopy,XPS and nano-indentation. The implantation of N2+ into a-C films offers a higher hardness thanthat directly synthesized by RIBSD, probably through an increase in sp3/sp2 ratio and in the pro-portion of nitrogen atoms chemically bonding to carbon atoms. The results show that althoughthere are differences in film composition, structure and properties between these two processes,both methods can be used for synthesis of nitrogen-containing amorphous DLC thin films whichsignificantly modify the substrate surface.

  15. Neutron personnel dosimetry

    International Nuclear Information System (INIS)

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments

  16. Carbon Ionic Conductors for use in Novel Carbon-Ion Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Franklin H. Cocks; W. Neal Simmons; Paul A. Klenk

    2005-11-01

    Carbon-consuming fuel cells have many potential advantages, including increased efficiency and reduced pollution in power generation from coal. A large amount of work has already been done on coal fuel cells that utilize yttria-stabilized zirconium carbide as an oxygen-ion superionic membrane material. But high-temperature fuel cells utilizing yttria-stabilized zirconium require partial combustion of coal to carbon monoxide before final oxidation to carbon dioxide occurs via utilization of the oxygen- ion zirconia membrane. A carbon-ion superionic membrane material would enable an entirely new class of carbon fuel cell to be developed, one that would use coal directly as the fuel source, without any intervening combustion process. However, a superionic membrane material for carbon ions has not yet been found. Because no partial combustion of coal would be required, a carbon-ion superionic conductor would allow the direct conversion of coal to electricity and pure CO{sub 2} without the formation of gaseous pollutants. The objective of this research was to investigate ionic lanthanide carbides, which have an unusually high carbon-bond ionicity as potential superionic carbide-ion conductors. A first step in this process is the stabilization of these carbides in the cubic structure, and this stabilization has been achieved via the preparation of pseudobinary lanthanide carbides. The diffusion rates of carbon have been measured in these carbides as stabilized to preserve the high temperature cubic structure down to room temperature. To prepare these new compounds and measure these diffusion rates, a novel, oxide-based preparation method and a new C{sup 13}/C{sup 12} diffusion technique have been developed. The carbon diffusion rates in La{sup 0.5}Er{sup 0.5}C{sub 2}, Ce{sup 0.5}Er{sup 0.5}C{sub 2}, and La{sup 0.5}Y{sup 0.5}C{sub 2}, and Ce{sup 0.5}Tm0.5C{sub 2} modified by the addition of 5 wt %Be{sub 2}C, have been determined at temperatures from 850 C to 1150 C. The

  17. Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes.

    Science.gov (United States)

    Licht, Stuart; Douglas, Anna; Ren, Jiawen; Carter, Rachel; Lefler, Matthew; Pint, Cary L

    2016-03-23

    The cost and practicality of greenhouse gas removal processes, which are critical for environmental sustainability, pivot on high-value secondary applications derived from carbon capture and conversion techniques. Using the solar thermal electrochemical process (STEP), ambient CO2 captured in molten lithiated carbonates leads to the production of carbon nanofibers (CNFs) and carbon nanotubes (CNTs) at high yield through electrolysis using inexpensive steel electrodes. These low-cost CO2-derived CNTs and CNFs are demonstrated as high performance energy storage materials in both lithium-ion and sodium-ion batteries. Owing to synthetic control of sp(3) content in the synthesized nanostructures, optimized storage capacities are measured over 370 mAh g(-1) (lithium) and 130 mAh g(-1) (sodium) with no capacity fade under durability tests up to 200 and 600 cycles, respectively. This work demonstrates that ambient CO2, considered as an environmental pollutant, can be attributed economic value in grid-scale and portable energy storage systems with STEP scale-up practicality in the context of combined cycle natural gas electric power generation. PMID:27163042

  18. 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.

  19. 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.

  20. Dosimetry Service

    CERN Multimedia

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter every month at least once and preferably during the first week. A regular read-out is indispensable in order to ensure a periodic monitoring of the personal dose. You should read your dosimeter even if you have not visited the controlled areas. If you still have the old dosimeter (film badge), please send it immediately for evaluation to us (Bdg 24 E-011). After January 2005 there will be no developing process for the old film system. Information for Contractors: Please remember also to bring the form ‘Confirm Reception of a CERN Dosimeter' signed with ‘Feuille d'enregistrement du CERN'. Without these forms the dosimeter cannot be assigned. Thank you for your cooperation. Dosimetry Service Tel 767 2155 http://cern.ch/rp-dosimetry

  1. Translational Research to Improve the Efficacy of Carbon Ion Radiotherapy: Experience of Gunma University.

    Science.gov (United States)

    Oike, Takahiro; Sato, Hiro; Noda, Shin-Ei; Nakano, Takashi

    2016-01-01

    Carbon ion radiotherapy holds great promise for cancer therapy. Clinical data show that carbon ion radiotherapy is an effective treatment for tumors that are resistant to X-ray radiotherapy. Since 1994 in Japan, the National Institute of Radiological Sciences has been heading the development of carbon ion radiotherapy using the Heavy Ion Medical Accelerator in Chiba. The Gunma University Heavy Ion Medical Center (GHMC) was established in the year 2006 as a proof-of-principle institute for carbon ion radiotherapy with a view to facilitating the worldwide spread of compact accelerator systems. Along with the management of more than 1900 cancer patients to date, GHMC engages in translational research to improve the treatment efficacy of carbon ion radiotherapy. Research aimed at guiding patient selection is of utmost importance for making the most of carbon ion radiotherapy, which is an extremely limited medical resource. Intratumoral oxygen levels, radiation-induced cellular apoptosis, the capacity to repair DNA double-strand breaks, and the mutational status of tumor protein p53 and epidermal growth factor receptor genes are all associated with X-ray sensitivity. Assays for these factors are useful in the identification of X-ray-resistant tumors for which carbon ion radiotherapy would be beneficial. Research aimed at optimizing treatments based on carbon ion radiotherapy is also important. This includes assessment of dose fractionation, normal tissue toxicity, tumor cell motility, and bystander effects. Furthermore, the efficacy of carbon ion radiotherapy will likely be enhanced by research into combined treatment with other modalities such as chemotherapy. Several clinically available chemotherapeutic drugs (carboplatin, paclitaxel, and etoposide) and drugs at the developmental stage (Wee-1 and heat shock protein 90 inhibitors) show a sensitizing effect on tumor cells treated with carbon ions. Additionally, the efficacy of carbon ion radiotherapy can be improved by

  2. Synthesis of lanthanum aluminate doped with carbon (LaAlO{sub 3}: C) by solid state reaction for application in thermoluminescent dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Alves, N.; Ferraz, W.B.; Faria, L.O., E-mail: alvesn@cdtn.br, E-mail: ferrazw@cdtn.br, E-mail: farialo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    One of the best TL materials ever discovered is α-Al2O3 single crystals doped with carbon atoms. Recently, LaAlO3:Ce,Dy crystals have been proposed to be used as a TL dosimeter for UV fields. Its crystalline structure is very similar to the Al2O3 ones. Thus, in this work, we explore the idea of introducing carbon atoms in the polycrystalline lattice of LaAlO3, in order to investigate its TL properties for X and gamma fields. In this study, the lanthanum aluminate was synthesized using the solid state reaction method by mixing aluminum and lanthanum oxide in a 1:1 molar ratio. The mixture with different concentrations of graphite was then first calcinated in the air and then sintered under reducing atmosphere at high temperature. The resulting powder was characterized by X-ray diffraction, confirming the attainment of the desired phase (LaAlO3). Among the different doping levels investigated all showed thermoluminescence, including the undoped LaAlO3. The best TL responses were obtained for pristine compositions and those doped with 0.5 at.% of carbon. An additional evaluation evidenced the presence of OSL peaks for samples doped with 2.0 at.% of carbon. The synthesis method has revealed to be effective for forming the lanthanum aluminate, with significant TL sensitivity. Because of these results, we believe that this new TL material has great potential for applications in radiation dosimetry. (author)

  3. Regeneration of spent powdered activated carbon saturated with inorganic ions by cavitation united with ion exchange method.

    Science.gov (United States)

    Li, Gang; Gao, Hong; Li, Yansheng; Yang, Huixin

    2011-06-01

    Using ion exchange resin as transfer media, regenerate powdered activated carbon (PAC) adsorbed inorganic ions by cavitation to enhance the transfer; we studied how the regeneration time and the mass ratio of resin and PAC influence the regeneration rate respectively through re-adsorption. The result showed that the effective regeneration of PAC saturated with inorganic ions was above 90% using ion exchange resin as media and transfer carrier, the quantity of PAC did not reduced but activated in the process. PMID:25084579

  4. Erythrocyte stiffness during morphological remodeling induced by carbon ion radiation.

    Directory of Open Access Journals (Sweden)

    Baoping Zhang

    Full Text Available The adverse effect induced by carbon ion radiation (CIR is still an unavoidable hazard to the treatment object. Thus, evaluation of its adverse effects on the body is a critical problem with respect to radiation therapy. We aimed to investigate the change between the configuration and mechanical properties of erythrocytes induced by radiation and found differences in both the configuration and the mechanical properties with involving in morphological remodeling process. Syrian hamsters were subjected to whole-body irradiation with carbon ion beams (1, 2, 4, and 6 Gy or X-rays (2, 4, 6, and 12 Gy for 3, 14 and 28 days. Erythrocytes in peripheral blood and bone marrow were collected for cytomorphological analysis. The mechanical properties of the erythrocytes were determined using atomic force microscopy, and the expression of the cytoskeletal protein spectrin-α1 was analyzed via western blotting. The results showed that dynamic changes were evident in erythrocytes exposed to different doses of carbon ion beams compared with X-rays and the control (0 Gy. The magnitude of impairment of the cell number and cellular morphology manifested the subtle variation according to the irradiation dose. In particular, the differences in the size, shape and mechanical properties of the erythrocytes were well exhibited. Furthermore, immunoblot data showed that the expression of the cytoskeletal protein spectrin-α1 was changed after irradiation, and there was a common pattern among its substantive characteristics in the irradiated group. Based on these findings, the present study concluded that CIR could induce a change in mechanical properties during morphological remodeling of erythrocytes. According to the unique characteristics of the biomechanical categories, we deduce that changes in cytomorphology and mechanical properties can be measured to evaluate the adverse effects generated by tumor radiotherapy. Additionally, for the first time, the current study

  5. Radiative transitions in highly-stripped carbon-like ions

    International Nuclear Information System (INIS)

    Transition energies and weighted absorption oscillator strength (gf) values are evaluated for a number of dipole-allowed transitions in highly-charged ions Ne4+, Si8+, Ar12+ and Ti16+ belong to the astrophysically important carbon series employing the time-dependent coupled Hartree-Fock (TDCHF) theory. Estimated values compare favourably with other existing results and the new ones repoted here may constitute a useful set for reference. The large-Z behaviour of the gf values is also examined. (orig.)

  6. 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.

  7. Characterization of carbon ion implantation induced graded microstructure and phase transformation in stainless steel

    International Nuclear Information System (INIS)

    Austenitic stainless steel 316L is ion implanted by carbon with implantation fluences of 1.2 × 1017 ions-cm− 2, 2.4 × 1017 ions-cm− 2, and 4.8 × 1017 ions-cm− 2. The ion implantation induced graded microstructure and phase transformation in stainless steel is investigated by X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. The corrosion resistance is evaluated by potentiodynamic test. It is found that the initial phase is austenite with a small amount of ferrite. After low fluence carbon ion implantation, an amorphous layer and ferrite phase enriched region underneath are formed. Nanophase particles precipitate from the amorphous layer due to energy minimization and irradiation at larger ion implantation fluence. The morphology of the precipitated nanophase particles changes from circular to dumbbell-like with increasing implantation fluence. The corrosion resistance of stainless steel is enhanced by the formation of amorphous layer and graphitic solid state carbon after carbon ion implantation. - Highlights: • Carbon implantation leads to phase transformation from austenite to ferrite. • The passive film on SS316L becomes thinner after carbon ion implantation. • An amorphous layer is formed by carbon ion implantation. • Nanophase precipitate from amorphous layer at higher ion implantation fluence. • Corrosion resistance of SS316L is improved by carbon implantation

  8. Particulate inverse opal carbon electrodes for lithium-ion batteries.

    Science.gov (United States)

    Kang, Da-Young; Kim, Sang-Ok; Chae, Yu Jin; Lee, Joong Kee; Moon, Jun Hyuk

    2013-01-29

    Inverse opal carbon materials were used as anodes for lithium ion batteries. We applied particulate inverse opal structures and their dispersion in the formation of anode electrodes via solution casting. We prepared aminophenyl-grafted inverse opal carbons (a-IOC), inverse opal carbons with mesopores (mIOC), and bare inverse opal carbons (IOC) and investigated the electrochemical behavior of these samples as anode materials. Surface modification by aminophenyl groups was confirmed by XPS measurements. TEM images showed mesopores, and the specific area of mIOC was compared with that of IOC using BET analysis. A half-cell test was performed to compare a-IOC with IOC and mIOC with IOC. In the case of the a-IOC structure, the cell test revealed no improvement in the reversible specific capacity or the cycle performance. The mIOC cell showed a reversible specific capacity of 432 mAh/g, and the capacity was maintained at 88%-approximately 380 mAh/g-over 20 cycles.

  9. EUD-based biological optimization for carbon ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brüningk, Sarah C., E-mail: sarah.brueningk@icr.ac.uk; Kamp, Florian; Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum rechts der Isar, Ismaninger Str. 22, München 81675, Germany and Physik-Department, Technische Universität München, James-Franck-Str. 1, Garching 85748 (Germany)

    2015-11-15

    Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

  10. Fabrication and Optimization of Carbon Nanomaterial-Based Lithium-Ion Battery Anodes

    OpenAIRE

    Somnhot, Parina

    2012-01-01

    Lithium-ion batteries possess high energy and power densities, making them ideal candidates for energy storage requirements in various military applications. Commercially produced lithium-ion battery anodes are commonly graphitic carbon-based. However, graphitic carbons are limited in surface area and possess slow intercalation kinetics. The energy and power density demands of future technologies require improved lithium-ion battery performance. Carbon nanomaterials, such as carbide-derived c...

  11. Metal carbonates as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Lianyi; Ma, Rui; Wu, Kaiqiang; Shui, Miao; Lao, Mengmeng; Wang, Dongjie; Long, Nengbing; Ren, Yuanlong; Shu, Jie, E-mail: sergio_shu@hotmail.com

    2013-12-25

    Highlights: •Metal carbonates are probable anode materials for lithium ion batteries. •CoCO{sub 3}/C composite can deliver an initial discharge capacity of 2096.6 mAh g{sup −1} . •Co, Li{sub 2}CO{sub 3}, Li{sub 2}O, and low-valence carbon are final lithiated products for CoCO{sub 3}. -- Abstract: Six metal carbonates (Li{sub 2}CO{sub 3}, Na{sub 2}CO{sub 3}, SrCO{sub 3}, BaCO{sub 3}, K{sub 2}CO{sub 3}, CoCO{sub 3}) are tested and compared as anode materials for lithium ion batteries. The electrochemical results show that only CoCO{sub 3} is electrochemically active material and can deliver a high initial capacity of 1425.9 mAh g{sup −1}. The lithium storage mechanism in CoCO{sub 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{sub 3} and Li firstly result in the formation of metal Co and Li{sub 2}CO{sub 3}, and then partial Li{sub 2}CO{sub 3} is further reduced into carbon (C{sup 0}), low-valence carbon (C{sup 2+}), and Li{sub 2}O. It also demonstrates that the electrochemical reaction between CoCO{sub 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{sub 3}/Li batteries by suppressing particle pulverization. Besides, the comparison of CoCO{sub 3}, ball-milled CoCO{sub 3} and ball-milled CoCO{sub 3}/C composite also indicates that smaller active particle and carbon buffer are beneficial to obtain better cycling performance and higher reversible capacity.

  12. Topics in radiation dosimetry radiation dosimetry

    CERN Document Server

    1972-01-01

    Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

  13. 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.

  14. TL dosimetry in the new Tandetron ion accelerator site of the National Institute of Nuclear Research (ININ)

    International Nuclear Information System (INIS)

    The National Institute of Nuclear Research (ININ) acquired a positive ions accelerator type Tandetron 2 MV of the dutch company High Voltage Engineering, Europe B.V., which was finished its installation this year (2000) in an already existing building in the Dr. Nabor Carrillo Flores Nuclear Centre, where it was prepared for the following purposes: the accelerator will be used to realize research through X-ray emission induced by charged particles, Rutherford backscattering analysis, nuclear reaction analysis, gamma ray emission induced by charged particles, resonant dispersion analysis, elastic backward detection analysis and by particle canalization analysis. The accelerator consists of an injection system with two ion sources, ion accelerator tank with voltage in terminal at 2 MV, recovery and recirculation system of charge interchange gas, iman selector analyzer system and with high energy focussing, control system through computer and management and recovery of isolator gas system. For the realization of operation tests of this accelerator, it was had the license authorizing by the National Commission of Nuclear Safety and Safeguards (CNSNS). During the test stage Tl dosemeters were arranged in the Tandetron accelerator area, and also in direction to the beam outlet. In this work, are presented the obtained results of the measurement of radiation levels, as in the area as in the beam outlet. (Author)

  15. Innershell ionization by fast protons, alpha particles and carbon ions

    International Nuclear Information System (INIS)

    The subject of this thesis is the study of inner-shell excitations of atoms induced by fast charged particle collisions. A new method is described for measuring the spectrum of delta-electrons emitted by 208Pb after excitation by 15 MeV protons or 50 MeV alpha particles. Experimental equipment is described. Results of both experiments are presented and compared with PWBA models and with calculations based on a semi-classical approximation. The small-impact-parameter ionization probabilities obtained are then compared with literature. Also small-impact-parameter measurements done with 100 MeV carbon ions are described. Besides K-shell measurements, the author also presents L-subshell ionization probability results for Pb. An appendix is added in which energy straggling problems in solid targets are treated. (Auth./G.J.P.)

  16. Carbon Ion Therapy for Early-Stage Non-Small-Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Yusuke Demizu

    2014-01-01

    Full Text Available Carbon ion therapy is a type of radiotherapies that can deliver high-dose radiation to a tumor while minimizing the dose delivered to the organs at risk; this profile differs from that of photon radiotherapy. Moreover, carbon ions are classified as high-linear energy transfer radiation and are expected to be effective for even photon-resistant tumors. Recently, high-precision radiotherapy modalities such as stereotactic body radiotherapy (SBRT, proton therapy, and carbon ion therapy have been used for patients with early-stage non-small-cell lung cancer, and the results are promising, as, for carbon ion therapy, local control and overall survival rates at 5 years are 80–90% and 40–50%, respectively. Carbon ion therapy may be theoretically superior to SBRT and proton therapy, but the literature that is currently available does not show a statistically significant difference among these treatments. Carbon ion therapy demonstrates a better dose distribution than both SBRT and proton therapy in most cases of early-stage lung cancer. Therefore, carbon ion therapy may be safer for treating patients with adverse conditions such as large tumors, central tumors, and poor pulmonary function. Furthermore, carbon ion therapy may also be suitable for dose escalation and hypofractionation.

  17. Relative biological effectiveness of carbon ions for causing fatal liver failure after partial hepatectomy in mice

    Energy Technology Data Exchange (ETDEWEB)

    Tomizawa, Minoru; Miyamoto, Tadaaki; Kato, Hirotoshi; Otsu, Hiroshi [National Inst. of Radiological Sciences, Chiba (Japan)

    2000-06-01

    To evaluate the acute phase damage to liver by carbon ions, BALB/c mice were irradiated with carbon ions or X-rays after two-thirds partial hepatectomy, and their survival was followed. The 50% lethal dose within 60 days (LD{sub 50/60}) was 42.2{+-}0.25 Gy (standard error) for X-rays, and 22.7{+-}0.25 Gy for carbon ions. The relative biological effectiveness (RBE) of carbon ions was 1.86 (95% confident limits: 1.69-2.04) as calculated from the LD{sub 50/60}. Mice irradiated at much higher doses, 60 Gy of X-rays or 24 Gy of carbon ions, showed significantly higher serum ammonia levels and lower serum albumin levels than normal, suggesting hepatic failure as a cause of death. Hepatocytes showed karyorrhexis and karyolysis in carbon ion irradiated and spotty necrosis in X-ray irradiated mice, suggesting nuclear damage. Mice irradiated with LD{sub 50} of X-rays or carbon ions had a remarkably lower bromodeoxyuridine (BrdU) labeling index and mitotic index than control. Treatments with both BrdU and vincristine showed that none of the hepatocytes that synthesized DNA after irradiation completed mitosis, indicating G2 arrest. The liver weight of irradiated mice significantly decreased depending on the dose. Carbon ions as well as X-rays damaged hepatocytes directly and suppressed liver regeneration leading to fatal liver failure. (author)

  18. Relative biological effectiveness of carbon ions for causing fatal liver failure after partial hepatectomy in mice

    International Nuclear Information System (INIS)

    To evaluate the acute phase damage to liver by carbon ions, BALB/c mice were irradiated with carbon ions or X-rays after two-thirds partial hepatectomy, and their survival was followed. The 50% lethal dose within 60 days (LD50/60) was 42.2±0.25 Gy (standard error) for X-rays, and 22.7±0.25 Gy for carbon ions. The relative biological effectiveness (RBE) of carbon ions was 1.86 (95% confident limits: 1.69-2.04) as calculated from the LD50/60. Mice irradiated at much higher doses, 60 Gy of X-rays or 24 Gy of carbon ions, showed significantly higher serum ammonia levels and lower serum albumin levels than normal, suggesting hepatic failure as a cause of death. Hepatocytes showed karyorrhexis and karyolysis in carbon ion irradiated and spotty necrosis in X-ray irradiated mice, suggesting nuclear damage. Mice irradiated with LD50 of X-rays or carbon ions had a remarkably lower bromodeoxyuridine (BrdU) labeling index and mitotic index than control. Treatments with both BrdU and vincristine showed that none of the hepatocytes that synthesized DNA after irradiation completed mitosis, indicating G2 arrest. The liver weight of irradiated mice significantly decreased depending on the dose. Carbon ions as well as X-rays damaged hepatocytes directly and suppressed liver regeneration leading to fatal liver failure. (author)

  19. 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 

  20. 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...

  1. SAGA-HIMAT project for carbon ion radiotherapy

    International Nuclear Information System (INIS)

    Project of SAGA Heavy Ion Medical Accelerator in Tosu (SAGA HIMAT) is promoted by Saga prefecture with private financial supports, investments, and also personal donations. With this funding, facility construction is conducted by a collaboration of SAGA-HIMAT foundation and SAGA HIMAT company. The facility is constructing in Tosu-shi near Shinn-Tosu shinkansen station, which has easy access from Kyushu island area and also south west Japan. In the facility, there are three treatment rooms, where first one has been equipped with horizontal and 45 degree oblique beam lines, second one has horizontal and vertical beam lines, and third one is for future preparation of spot scanning irradiation system. Design of an accelerator itself is same as a therapy facility at Gunma University, i.e., acceleration ion is carbon, maximum beam energy is 400MeV/u, and maximum beam intensity is 1.3x109pps. An injection line to a synchrotron and transport lines to three treatment rooms had been rearranged. Designs of the accelerator and an irradiation system have started at beginning of 2010, and the construction of a facility building has started at beginning of this year (2011). Installations of accelerator devices are expected to start at beginning of 2012, and the facility is planned to complete in 2013. In this paper, we present our project and current status of the facility construction. (author)

  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. Experimental studies of superhard materials carbon nitride CNx prepared by ion-beam synthesis method

    Institute of Scientific and Technical Information of China (English)

    辛火平; 林成鲁; 许华平; 邹世昌; 石晓红; 吴兴龙; 朱宏; P.L.FHemment

    1996-01-01

    Formation of superhard materials carbon nitride CNt by using ion-beam synthesis method is reported.100-keV high-dose N+ ions were implanted into carbon thin films at different temperatures.The samples were evaluated by X-ray photoelectron spectroscopy (XPS),Fourier transformation-infrared absorption spectroscopy (FTIR),Raman spectroscopy,cross-sectional transmission electron microscopy (XTEM),Rutherford backscattering spectroscopy (RBS).X-ray diffraction analysis (XRD) and Vickers microhardness measurement.The results show that the buried carbon nitride CN> layer has been successfully formed by using 100-keV high-dose N+ ions implantation into carbon thin film.Implantation of reactive ions into silicon (IRIS) computer program has been used to simulate the formation of the buried β-C3N4 layer as N+ ions are implanted into carbon.A good agreement between experimental measurements and IRIS simulation is found.

  4. 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.)

  5. 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

  6. Simulation of stripping injection into HITFiL with carbon ion

    CERN Document Server

    Xie, Xiucui; Zhang, Xiaohu

    2013-01-01

    Stripping injection is one of the crucial stages in the accumulation process of the hadron therapy synchrotron HITFiL (Heavy Ion Therapy Facility in Lanzhou). In order to simulate the stripping injection process of carbon ions for HITFiL, the interactions between carbon ions and foil has been studied, and simulated with a code developed by ourselves .The optimized parameters of the injecting beam and the scheme of the injection system have been presented for HITFiL.

  7. Simulation of stripping injection into HITFiL with carbon ion

    Institute of Scientific and Technical Information of China (English)

    XIE Xiu-Cui; SONG Ming-Tao; ZHANG Xiao-Hu

    2013-01-01

    Stripping injection is one of the crucial stages in the accumulation process of the hadron therapy synchrotron HITFiL (Heavy Ion Therapy Facility in Lanzhou).In order to simulate the stripping injection process of carbon ions for HITFiL,the interactions between carbon ions and foil has been studied,and simulated with a code developed by ourselves.The optimized parameters of the injecting beam and the scheme of the injection system have been presented for HITFiL.

  8. Topical Review: Polymer gel dosimetry

    OpenAIRE

    Baldock, C; De Deene, Y; Doran, S.; Ibbott, G; Jirasek, A.; Lepage, M.; McAuley, K B; Oldham, M; Schreiner, L J

    2010-01-01

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose ...

  9. 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.

  10. A disordered carbon as a novel anode material in lithium-ion cells

    Energy Technology Data Exchange (ETDEWEB)

    Bonino, F.; Brutti, S.; Reale, P.; Scrosati, B. [Dipartimento di Chimica, Universita ' ' La Sapienza' ' , I-00185 Rome (Italy); Gherghel, L.; Wu, J.; Muellen, K. [Max Planck Institute for Polymer Research, Ackermannweg 10, D-55124 Mainz (Germany)

    2005-03-22

    The electrochemical behavior of a disordered carbon used as the anode in a lithium battery has been tested. The characteristics of this carbon, especially its specific capacity and cycle life, are such that it is a potentially unique, high-performance anode material for new types of lithium-ion batteries. The Figure shows the specific capacity versus cycle number of the disordered carbon electrode in a lithium-ion cell. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  11. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  12. TL Dosimetry on the Tandetron Ion Accelerator area of the ININ; Dosimetria TL en el area del Acelerador de iones Tandetron del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Valdovinos A, M.A.; Gonzalez M, P.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    For the fulfilment of the operation tests of the Positive Ions type Tandetron 4120 MC, 2 MV, it was obtained the permission consented by the National Commission of Nuclear safety and safeguards (CNSNS). During the stage of tests were arranged Tl dosemeters in the Tandetron Accelerator area, as well as toward to the beam exit. In this work, it was presented the results obtained of the measurement of radiation levels, as much in the area as in the beam exit. This Accelerator is useful in different fields of science such as: biology, radiochemistry, materials, solid state physics, archaeology and environmental sciences between others. (Author)

  13. Numerical modeling of ion dynamics in a carbon nanotube field-ionized thruster

    OpenAIRE

    Michael, Sarah F.

    2011-01-01

    Approved for public release; distribution is unlimited Carbon nanotube field ionization technology has the potential to make ion propulsion feasible for use in micro and nano-satellites. To better understand the phenomenon and optimize the ion thruster design, it is useful to have an accurate model of the system. Numerical modeling of large-scale electron bombardment ion engines is a relatively mature field, but modeling of field-ionized ion engines is in its infancy. A simpler code may be...

  14. Neutron dosimetry - A review

    International Nuclear Information System (INIS)

    This review summarizes information on the following subjects: (1) physical processes of importance in neutron dosimetry; (2) biological effects of neutrons; (3) neutron sources; and (4) instruments and methods used in neutron dosimetry. Also, possible improvements in dosimetry instrumentation are outlined and discussed. (author)

  15. Effect of carbon ions on life span shortening and tumorigenesis in mice.

    Science.gov (United States)

    Kakinuma, Shizuko; Kubo, Ayumi; Amasaki, Yoshiko; Nohima, Kumie; Imaoka, Tatsuhiko; Nishimura, Mayumi; Shimada, Yoshiya

    2004-11-01

    One of the important concerns for astronauts in space is cancer risk associated with cosmic radiation, including heavy particle ions. But little information on cancer risk is available. We investigated the effect of carbon ions on life span shortening and tumor induction in B6C3F1 mice. The mice were exposed weekly to 0.4 and 2.0 Gy whole-body carbon-ion- or X-ray-irradiation for 4 consecutive weeks. The spectrum of induced tumors varied depending on the dose. The cause of death was thymic lymphomas and liver tumors at high and low dose, respectively. The life span shortening by X-rays was proportional to dose, while carbon ions produced a convex upward relationship. The relative biological effectiveness for the 50% life span shortening was about 1.4. The large effect of carbon ions encourages the study on tumor induction at low doses in the space. PMID:15900637

  16. Differential effects of irradiation with carbon ions and x-rays on macrophage function.

    Science.gov (United States)

    Conrad, Sandro; Ritter, Sylvia; Fournier, Claudia; Nixdorff, Kathryn

    2009-05-01

    Macrophages are potent elicitors of inflammatory reactions that can play both positive and negative roles in radiotherapy. While several studies have investigated the effects of X-rays or gamma-rays on macrophages, virtually no work has been done on the responses of these cells to irradiation with carbon ions. Investigations into the effects of carbon ion irradiation are of particular interest in light of the fact that this type of radiation is being used increasingly for cancer therapy. In the present investigation we compared the effects of 250 kV X-rays with those of 9.8 MeV/u carbon ions on RAW 264.7 macrophages over a wide range of radiation doses. Macrophage functions including vitality, phagocytic activity, production of the proinflammatory cytokines IL-1beta and TNFalpha and production of nitric oxide (NO) were measured. In comparison to lymphocytes and fibroblasts, macrophages showed only a small decrease in vitality after irradiation with either X-rays or carbon ions. Proinflammatory cytokines and NO were induced in macrophages by LPS but not by irradiation alone. X-rays or carbon ions had little modulating effect on LPS-induced TNFalpha production. However, LPS-induced NO increased in a dose dependent manner up to 6-fold after carbon ion irradiation, while X-ray irradiation did not have this effect. Carbon ion irradiation mediated a concomitant decrease in IL-1beta production. Carbon ions also had a greater effect than X-rays in enhancing the phagocytic activity of macrophages. These results underscore the greater potential of carbon ion irradiation with regard to radiobiological effectiveness.

  17. Natural variability in the surface ocean carbonate ion concentration

    Directory of Open Access Journals (Sweden)

    N. S. Lovenduski

    2015-08-01

    Full Text Available 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 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 timeseries 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

  18. Behavior of the extraction of metallic ions in carbonate medium, using N-benzoylphenylhydroxylamine (BPHA) - benzene

    International Nuclear Information System (INIS)

    The possibility of separating quantitatively trace impurities like Cu, Fe, In and Pb, present in uranium base materials of nuclear grade, is demonstrated. A solvent extraction is employed which makes use of -benzoylphenylhydroxylamine(BPHA)-benzene solution and separation is effected in a medium containing 252 moles per liter of sodium-uranyl tricarbonate at pH of 9,0. Carbonate ions under such conditions inhibit uranium extraction by masking uranyl ion-BPHA reaction. The uranyl ions show a demasking action, releasing, thereby, Pb(II) ions which are being extracted from carbonate medium. The Atomic Absorption Spectrophometry technique is used to obtain the experimental data

  19. Protons from carbon ion fragmentation at 0.3–2.0 GeV/nucleon: Comparison with models of ion-ion interactions

    International Nuclear Information System (INIS)

    Yields of protons at 3.5° from carbon ion fragmentation at energies of T0 = 0.3, 0.6, 0.95, and 2.0 GeV/nucleon on a Be target were measured in the FRAGM experiment at TWA-ITEP heavy-ion facility. Proton momentum spectra cover both the region of the fragmentation maximum and the cumulative region. The differential cross sections span six orders of its magnitude. The spectra are compared with the predictions of four models of ion-ion interactions: LAQGSM03.03, SHIELD-HIT, QMD, and BC

  20. Ion beam deposition of amorphous carbon films with diamond like properties

    Science.gov (United States)

    Angus, John C.; Mirtich, Michael J.; Wintucky, Edwin G.

    1982-01-01

    Carbon films were deposited on silicon, quartz, and potassium bromide substrates from an ion beam. Growth rates were approximately 0.3 micron/hour. The films were featureless and amorphous and contained only carbon and hydrogen in significant amounts. The density and carbon/hydrogen ratio indicate the film is a hydrogen deficient polymer. One possible structure, consistent with the data, is a random network of methylene linkages and tetrahedrally coordinated carbon atoms.

  1. 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...

  2. Centrifugally-spun carbon microfibers and porous carbon microfibers as anode materials for sodium-ion batteries

    Science.gov (United States)

    Dirican, Mahmut; Zhang, Xiangwu

    2016-09-01

    Natural abundance and low cost of sodium resources bring forward the sodium-ion batteries as a promising alternative to widely-used lithium-ion batteries. However, insufficient energy density and low cycling stability of current sodium-ion batteries hinder their practical use for next-generation smart power grid and stationary storage applications. Electrospun carbon microfibers have recently been introduced as a high-performance anode material for sodium-ion batteries. However, electrospinning is not feasible for mass production of carbon microfibers due to its complex processing condition, low production rate and high cost. Herein, we report centrifugal spinning, a high-rate and low-cost microfiber production method, as an alternative approach to electrospinning for carbon microfiber production and introduce centrifugally-spun carbon microfibers (CMFs) and porous carbon microfibers (PCMFs) as anode materials for sodium-ion batteries. Electrochemical performance results indicated that the highly porous nature of centrifugally-spun PCMFs led to increased Na+ storage capacity and improved cycling stability. The reversible capacity of centrifugally-spun PCMF anodes at the 200th cycle was 242 mAh g-1, which was much higher than that of centrifugally-spun CMFs (143 mAh g-1). The capacity retention and coulombic efficiency of the centrifugally-spun PCMF anodes were 89.0% and 99.9%, respectively, even at the 200th cycle.

  3. Carbon Ion Irradiation Inhibits Glioma Cell Migration Through Downregulation of Integrin Expression

    International Nuclear Information System (INIS)

    Purpose: To investigate the effect of carbon ion irradiation on glioma cell migration. Methods and Materials: U87 and Ln229 glioma cells were irradiated with photons and carbon ions. Migration was analyzed 24 h after irradiation. Fluorescence-activated cell sorting analysis was performed in order to quantify surface expression of integrins. Results: Single photon doses of 2 Gy and 10 Gy enhanced ανβ3 and ανβ5 integrin expression and caused tumor cell hypermigration on both vitronectin (Vn) and fibronectin (Fn). Compared to integrin expression in unirradiated cells, carbon ion irradiation caused decreased integrin expression and inhibited cell migration on both Vn and Fn. Conclusion: Photon radiotherapy (RT) enhances the risk of tumor cell migration and subsequently promotes locoregional spread via photon induction of integrin expression. In contrast to photon RT, carbon ion RT causes decreased integrin expression and suppresses glioma cell migration on both Vn and Fn, thus promising improved local control.

  4. Clinical results of carbon ion radiotherapy for bone and soft tissue tumors

    International Nuclear Information System (INIS)

    First choice of treatment for bone and soft tissue tumors is surgical tumor resection, but some cases have difficulties to resect radically because of tumor size, location, or their reduction in QOL after surgery. Carbon ion radiotherapy has been reported that have both good local tumor control and high QOL for patients with bone and soft tissue tumors, especially sacral chordoma and unresectable osteosarcoma of the tract. Some articles of the results with carbon ion radiotherapy for sacral chordoma show better local control and QOL than that of surgery. Moreover, several reports show good local control and preservation of QOL for patients with unresectable osteosarcoma of the tract, retroperitoneal sarcoma, and other situations of sarcomas. Now carbon ion radiotherapy can offer a promising alternative to surgery for patients with unresectable sarcomas. We will discuss about the results of carbon ion radiotherapy for bone and soft tissue tumors in this issue. (author)

  5. Effect of carbon coating on electrochemical performance of hard carbons as anode materials for lithium-ion batteries

    Science.gov (United States)

    Lee, Jong-Hyuk; Lee, Heon-Young; Oh, Seh-Min; Lee, Seo-Jae; Lee, Ki-Young; Lee, Sung-Man

    Surface modification by a soft-carbon coating is used to improve the electrochemical performance of hard carbons as the negative-electrode (anode) material in lithium-ion batteries. The coating process involves simple heat-treatment of a mixture of coal-tar pitch and hard carbon powders at 1000 °C. The carbon coating significantly reduces the reaction of lithium with surface functional groups or absorbed species caused by air exposure. This is attributed to the effective suppression of the diffusion of both air and water into the hard carbon by the soft-carbon coating, and the better resistance of soft carbon to air. As a result, the charge-discharge coulombic efficiency during cycling, as well as during the first cycle, is improved.

  6. 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.

  7. Unexpected radiation laryngeal necrosis after carbon ion therapy using conventional dose fractionation for laryngeal cancer.

    Science.gov (United States)

    Demizu, Yusuke; Fujii, Osamu; Nagano, Fumiko; Terashima, Kazuki; Jin, Dongcun; Mima, Masayuki; Oda, Naoharu; Takeuchi, Kaoru; Takeda, Makiko; Ito, Kazuyuki; Fuwa, Nobukazu; Okimoto, Tomoaki

    2015-11-01

    Carbon ion therapy is a type of radiotherapy that can deliver high-dose radiation to a tumor while minimizing the dose delivered to organs at risk. Moreover, carbon ions are classified as high linear energy transfer radiation and are expected to be effective for even photon-resistant tumors. A 73-year-old man with glottic squamous cell carcinoma, T3N0M0, refused laryngectomy and received carbon ion therapy of 70 Gy (relative biological effectiveness) in 35 fractions. Three months after the therapy, the patient had an upper airway inflammation, and then laryngeal edema and pain occurred. Five months after the therapy, the airway stenosis was severe and computed tomography showed lack of the left arytenoid cartilage and exacerbation of laryngeal necrosis. Despite the treatment, 5 and a half months after the therapy, the laryngeal edema and necrosis had become even worse and the surrounding mucosa was edematous and pale. Six months after the therapy, pharyngolaryngoesophagectomy and reconstruction with free jejunal autograft were performed. The surgical specimen pathologically showed massive necrosis and no residual tumor. Three years after the carbon ion therapy, he is alive without recurrence. The first reported laryngeal squamous cell carcinoma case treated with carbon ion therapy resulted in an unexpected radiation laryngeal necrosis. Tissue damage caused by carbon ion therapy may be difficult to repair even for radioresistant cartilage; therefore, hollow organs reinforced by cartilage, such as the larynx, may be vulnerable to carbon ion therapy. Caution should be exercised when treating tumors in or adjacent to such organs with carbon ion therapy.

  8. Clinical output factors for carbon-ion beams passing through polyethylene

    CERN Document Server

    Kanematsu, Nobuyuki; Ogata, Risa; Himukai, Takeshi

    2013-01-01

    Purpose: A recent study suggested that polyethylene (PE) range compensators would cause extra carbon-ion attenuation by 0.45%/cm due to limitations in water equivalence. The present study aims to assess its influence on tumor dose in carbon-ion radiotherapy. Methods: Carbon-ion radiation was modeled to be composed of primary carbon ions and secondary particles. For these components, tumor dose fraction and relative biological effectiveness (RBE) were estimated at a reference depth in the middle of spread-out Bragg peak. The PE effect was estimated for clinical carbon-ion beams and was partially tested by experiment. The two-component model was integrated into a treatment-planning system, with which the PE effect on tumor dose was investigated in two clinical cases. Results: The fluence and clinical attenuation coefficients for dose decrease per polyethylene thickness were estimated to be 0.1%-0.3%/cm and 0.2%-0.4%/cm, depending on energy and modulation of clinical carbon-ion beams. In the treatment-planning s...

  9. Collisions of fast, highly stripped carbon, niobium, and lead ions with molecular hydrogen

    International Nuclear Information System (INIS)

    The range of experimental confirmation of our scaling rule for electron loss from a hydrogen atom in collision with a heavy, highly stripped ion has been considerably broadened by new measurements on carbon-, niobium-, and lead-ion projectiles in molecular hydrogen

  10. Hypofractionated carbon ion therapy delivered with scanned ion beams for patients with hepatocellular carcinoma – feasibility and clinical response

    International Nuclear Information System (INIS)

    Photon-based radiation therapy does currently not play a major role as local ablative treatment for hepatocellular carcinoma (HCC). Carbon ions offer distinct physical and biological advantages. 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. Furthermore, carbon ions have an increased relative biological effectiveness (RBE) compared to photons. A total of six patients with one or more HCC-lesions were treated with carbon ions delivered by the raster-scanning technique according to our clinical trial protocol. Diagnosis of HCC was confirmed by histology or two different imaging modalities (CT and MRI) according to the AASLD-guidelines. Applied fractionation scheme was 4 × 10 Gy(RBE). Correct dose application was controlled by in-vivo PET measurement of β + −activity in the irradiated tissue shortly after treatment. Patients were observed for a median time period of 11.0 months (range, 3.4 – 12.7 months). Imaging studies showed a partial response in 4/7 lesions and a stable disease in 3/7 lesions in follow-up CT- and MRI scans. Local control was 100%. One patient with multifocal intrahepatic disease underwent liver transplantation 3 months after carbon ion therapy. During radiotherapy and the follow-up period no severe adverse events have occurred. We report the first clinical results of patients with HCC undergoing carbon ion therapy using the rasterscanning technique at our institution. All patients are locally controlled and experienced no higher toxicities in a short follow-up period. Further patients will be included in our prospective Phase-I clinical trial PROMETHEUS-01 (NCT01167374)

  11. 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.

  12. Modifying the electronic structure of semiconducting single-walled carbon nanotubes by Ar+ ion irradiation

    NARCIS (Netherlands)

    Tolvanen, A.; Buchs, G.; Ruffieux, P.; Gröning, P.; Gröning, O.; Krasheninnikov, A.V.

    2009-01-01

    Local controllable modification of the electronic structure of carbon nanomaterials is important for the development of carbon-based nanoelectronics. By combining density-functional theory simulations with Ar-ion-irradiation experiments and low-temperature scanning tunneling microscopy and spectrosc

  13. Metal Ions Extraction with Glucose Derivatives as Chelating Reagents in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    Guo Chen YANG; Hai Jian YANG

    2006-01-01

    A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-1-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives were selective for Sr2+ and Pb2+ extraction in supercritical carbon dioxide.

  14. Charge equilibrium of a laser-generated carbon-ion beam in warm dense matter

    International Nuclear Information System (INIS)

    Using ion carbon beams generated by high intensity short pulse lasers we perform measurements of single shot mean charge equilibration in cold or isochorically heated solid density aluminum matter. We demonstrate that plasma effects in such matter heated up to 1 eV do not significantly impact the equilibration of carbon ions with energies 0.045-0.5 MeV/nucleon. Furthermore, these measurements allow for a first evaluation of semiempirical formulas or ab initio models that are being used to predict the mean of the equilibrium charge state distribution for light ions passing through warm dense matter. (authors)

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

    OpenAIRE

    Jeongwoon Hwang; Jisoon Ihm; Kwang-Ryeol Lee; Seungchul Kim

    2015-01-01

    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 decrease...

  16. Tilting of carbon encapsulated metallic nanocolumns in carbon-nickel nanocomposite films by ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Matthias [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Technische Universitaet Dresden, D-01062 Dresden (Germany); Muecklich, Arndt; Zschornak, Matthias; Wintz, Sebastian; Gemming, Sibylle; Abrasonis, Gintautas [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Oates, Thomas W. H. [Leibniz-Institut fuer Analytische Wissenschaft, ISAS e.V., Albert-Einstein-Str. 9, 12489 Berlin (Germany); Luis Endrino, Jose [Surfaces and Coatings Department, Instituto de Ciencia de Materiales de Madrid, c/Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain); Baehtz, Carsten; Shalimov, Artem [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Rossendorf Beamline, European Synchrotron Radiation Facility, F-38043 Grenoble (France)

    2012-07-30

    The influence of assisting low-energy ({approx}50-100 eV) ion irradiation effects on the morphology of C:Ni ({approx}15 at. %) nanocomposite films during ion beam assisted deposition (IBAD) is investigated. It is shown that IBAD promotes the columnar growth of carbon encapsulated metallic nanoparticles. The momentum transfer from assisting ions results in tilting of the columns in relation to the growing film surface. Complex secondary structures are obtained, in which a significant part of the columns grows under local epitaxy via the junction of sequentially deposited thin film fractions. The influence of such anisotropic film morphology on the optical properties is highlighted.

  17. Measurement assurance in dosimetry

    International Nuclear Information System (INIS)

    The uses of radiation in medicine and industry are today wide in scope and diversity and there is a need for reliable dosimetry in most applications. In particular, high accuracy in dosimetry is required in the therapeutic use of radiation. Consequently, calibration procedures for radiotherapy generally meet also the accuracy requirements for applications in other fields, such as diagnostic radiology, radiation protection and industrial radiation processing. The emphasis at this symposium was therefore mainly or radiotherapy dosimetry, but the meeting also included one session devoted to dosimetry in diagnostic radiology. Refs, fig and tabs

  18. Electrochemical quartz crystal microbalance (EQCM) study of ion dynamics in nanoporous carbons.

    Science.gov (United States)

    Tsai, Wan-Yu; Taberna, Pierre-Louis; Simon, Patrice

    2014-06-18

    Electrochemical quartz crystal microbalance (EQCM) and cyclic voltammetry (CV) measurements were used to characterize ion adsorption in carbide-derived carbon (CDC) with two different average pore sizes (1 and 0.65 nm), from neat and solvated 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) electrolytes. From the electrode mass change in neat EMI-TFSI, it was shown that one net charge stored corresponds almost to one single ion at high polarization; in that case, no ion-pairing or charge screening by co-ions were observed. In 2 M EMI-TFSI in acetonitrile electrolyte, experimental solvation numbers were estimated for EMI(+) cation, showing a partial desolvation when cations were adsorbed in confined carbon pores. The extent of desolvation increased when decreasing the carbon pore size (from 1 down to 0.65 nm). The results also suggest that EMI(+) cation owns higher mobility than TFSI(-) anion in these electrolytes.

  19. Effect of p53 on lung carcinoma cells irradiated by carbon ions or X-rays

    Institute of Scientific and Technical Information of China (English)

    XIE Yi; ZHANG Hong; HAO Jifang; ZHAO Weiping; WU Zhenhua; QIU Rong; WANG Xiaohu

    2009-01-01

    The study is to investigate the feasibility and advantages of heavy ion beams on radiotherapy. The cellular cycle and apoptosis, cell reproductive death and p53 expression evaluated with flow cytometry, clonogenic survival assays and Western blot analysis were examined in lung carcinoma cells after exposure to 89.63 MeV/u carbon ion and 6 MV X-ray irradiations, respectively. The results showed that the number colonyforming assay of A549 was higher than that of H1299 cells in two radiation groups; A549 cellular cycle was arrested in G2/M in 12 h and the per-centage of apoptosis ascended at each time point of carbon ion radiation with doses, the expression of p53 upregulated with doses exposed to X-ray or carbon ion. The cell number in G2/M of H1299 and apoptosis were increasing at all time points with doses in 12C6+ ion irradiation group. The results suggested that the effects of carbon ions or X rays ir-radiation on lung carcinoma cells were different, 12C6+ ion irradiation could have more effect on upregulating the ex-pression of p53 than X-ray, and the upregulated expression of p53 might produce the cellular cycle G2/M arrested, apoptosis increasing; and p53 gene might affect the lung cancer cells radiosensitivity.

  20. 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.

  1. Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

    International Nuclear Information System (INIS)

    Highlights: ► Highly ordered three dimensional macroporous carbon spheres (MPCSs) were prepared. ► MPCS was covalently modified by cysteine (MPCS–CO–Cys). ► MPCS–CO–Cys was first time used in electrochemical detection of heavy metal ions. ► Heavy metal ions such as Pb2+ and Cd2+ can be simultaneously determined. -- Abstract: An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.

  2. The Anion Effect on Li+ Ion Coordination Structure in Ethylene Carbonate Solutions

    CERN Document Server

    Jiang, Bo; Shen, Yuneng; Yang, Xueming; Yuan, Kaijun; Vetere, Valentina; Mossa, Stefano; Skarmoutsos, Ioannis; Zhang, Yufan; Zheng, Junrong

    2016-01-01

    Rechargeable lithium ion batteries are an attractive alternative power source for a wide variety of applications. To optimize their performances, a complete description of the solvation properties of the ion in the electrolyte is crucial. A comprehensive understanding at the nanoscale of the solvation structure of lithium ions in nonaqueous carbonate electrolytes is, however, still unclear. We have measured by femtosecond vibrational spectroscopy the orientational correlation time of the CO stretching mode of Li+-bound and Li+-unbound ethylene carbonate molecules, in LiBF4, LiPF6, and LiClO4 ethylene carbonate solutions with different concentrations. Surprisingly, we have found that the coordination number of ethylene carbonate in the first solvation shell of Li+ is only two, in all solutions with concentrations higher than 0.5 M. Density functional theory calculations indicate that the presence of anions in the first coordination shell modifies the generally accepted tetrahedral structure of the complex, all...

  3. Successive ionization of positive ions of carbon and nitrogen by electron bombardment

    International Nuclear Information System (INIS)

    Experimental studies of deep ionization of heavy ions are described. The applications of such studies in atomic physics, plasma physics and space physics are discussed. Investigations using intersecting ion-electron beams, shifted beams and ion trap sources are described, and data are presented for multi-charged ions of carbon, oxygen and nitrogen. A detailed description of the development of the IEL (electron beam ionizer) source, and the KRION (cryogenic version) source is given, and further data for the multiple ionization of carbon and nitrogen are given for charge states up to C6+ and N7+. The advantages and disadvantages of the KRION source are discussed, and preliminary studies of a new torroidal ion trap source (HIRAC) are presented. (11 figs, 57 refs) (U.S.)

  4. Confinement, Desolvation, And Electrosorption Effects on the Diffusion of Ions in Nanoporous Carbon Electrodes.

    Science.gov (United States)

    Pean, Clarisse; Daffos, Barbara; Rotenberg, Benjamin; Levitz, Pierre; Haefele, Matthieu; Taberna, Pierre-Louis; Simon, Patrice; Salanne, Mathieu

    2015-10-01

    Supercapacitors are electrochemical devices which store energy by ion adsorption on the surface of a porous carbon. They are characterized by high power delivery. The use of nanoporous carbon to increase their energy density should not hinder their fast charging. However, the mechanisms for ion transport inside electrified nanopores remain largely unknown. Here we show that the diffusion is characterized by a hierarchy of time scales arising from ion confinement, solvation, and electrosorption effects. By combining electrochemistry experiments with molecular dynamics simulations, we determine the in-pore conductivities and diffusion coefficients and their variations with the applied potential. We show that the diffusion of the ions is slower by 1 order of magnitude compared to the bulk electrolyte. The desolvation of the ions occurs on much faster time scales than electrosorption.

  5. Field-effect ion-transport devices with carbon nanotube channels: schematics and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju Yul; Kang, Jeong Won; Byun, Ki Ryang; Kang, Eu Seok; Hwang, Ho Jung [Chung-Ang University, Seoul (Korea, Republic of); Lee, Jun Ha; Lee, Hoong Joo [Sangmyung University, Chonan (Korea, Republic of); Kwon, Oh Keun [Semyung University, Jecheon (Korea, Republic of); Kim, Young Min [Chung-Cheong University, Cheongwon (Korea, Republic of)

    2004-08-15

    We investigated field-effect ion-transport devices based on carbon nanotubes by using classical molecular dynamics simulations under applied external force fields, and we present model schematics that can be applied to the nanoscale data storage devices and unipolar ionic field-effect transistors. As the applied external force field is increased, potassium ions rapidly flow through the nanochannel. Under low external force fields, thermal fluctuations of the nanochannels affect tunneling of the potassium ions whereas the effects of thermal fluctuations are negligible under high external force fields. Since the electric current conductivity increases when potassium ions are inserted into fullerenes or carbon nanotubes, the field effect due to the gate, which can modify the position of the potassium ions, changes the tunneling current between the drain and the source.

  6. Confinement, Desolvation, And Electrosorption Effects on the Diffusion of Ions in Nanoporous Carbon Electrodes.

    Science.gov (United States)

    Pean, Clarisse; Daffos, Barbara; Rotenberg, Benjamin; Levitz, Pierre; Haefele, Matthieu; Taberna, Pierre-Louis; Simon, Patrice; Salanne, Mathieu

    2015-10-01

    Supercapacitors are electrochemical devices which store energy by ion adsorption on the surface of a porous carbon. They are characterized by high power delivery. The use of nanoporous carbon to increase their energy density should not hinder their fast charging. However, the mechanisms for ion transport inside electrified nanopores remain largely unknown. Here we show that the diffusion is characterized by a hierarchy of time scales arising from ion confinement, solvation, and electrosorption effects. By combining electrochemistry experiments with molecular dynamics simulations, we determine the in-pore conductivities and diffusion coefficients and their variations with the applied potential. We show that the diffusion of the ions is slower by 1 order of magnitude compared to the bulk electrolyte. The desolvation of the ions occurs on much faster time scales than electrosorption. PMID:26369420

  7. 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.

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

    International Nuclear Information System (INIS)

    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

  9. 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 in

  10. Monte Carlo simulations of the relative biological effectiveness for DNA double strand breaks from 300 MeV u−1 carbon-ion beams

    International Nuclear Information System (INIS)

    Monte Carlo simulations are used to calculate the relative biological effectiveness (RBE) of 300 MeV u−1 carbon-ion beams at different depths in a cylindrical water phantom of 10 cm radius and 30 cm long. RBE values for the induction of DNA double strand breaks (DSB), a biological endpoint closely related to cell inactivation, are estimated for monoenergetic and energy-modulated carbon ion beams. Individual contributions to the RBE from primary ions and secondary nuclear fragments are simulated separately. These simulations are based on a multi-scale modelling approach by first applying the FLUKA (version 2011.2.17) transport code to estimate the absorbed doses and fluence energy spectra, then using the MCDS (version 3.10A) damage code for DSB yields. The approach is efficient since it separates the non-stochastic dosimetry problem from the stochastic DNA damage problem. The MCDS code predicts the major trends of the DSB yields from detailed track structure simulations. It is found that, as depth is increasing, RBE values increase slowly from the entrance depth to the plateau region and change substantially in the Bragg peak region. RBE values reach their maxima at the distal edge of the Bragg peak. Beyond this edge, contributions to RBE are entirely from nuclear fragments. Maximum RBE values at the distal edges of the Bragg peak and the spread-out Bragg peak are, respectively, 3.0 and 2.8. The present approach has the flexibility to weight RBE contributions from different DSB classes, i.e. DSB0, DSB+ and DSB++. (paper)

  11. Spray-pyrolyzed silicon/disordered carbon nanocomposites for lithium-ion battery anodes

    Science.gov (United States)

    Ng, S. H.; Wang, J.; Konstantinov, K.; Wexler, D.; Chew, S. Y.; Guo, Z. P.; Liu, H. K.

    A new and effective approach to prepare carbon-coated Si nanocomposites as high capacity anode materials for lithium-ion batteries with markedly improved electrochemical performance is described. Initially, nanosized Si particles (citric acid in ethanol solution via ultrasonication. Spray pyrolysis of these mixtures at 400 °C in air resulted in an amorphous carbon coating on the spherical Si nanoparticles. High-resolution transmission electron microscopy (HRTEM) analysis confirms a homogeneous layer of amorphous carbon coating of ∼10 nm. These resultant nanocomposites show excellent cycling performance, especially when the disordered carbon (DC) content is above 50 wt.%. The 44Si/56DC nanocomposite shows the highest specific capacity retention of 1120 mAh g -1 after 100 cycles. The carbon-coating on the nanocrystalline Si particles appears to be the main reason for the good cyclability, suggesting the excellent potential of these Si/DC-based nanocomposites for use as alternative anodes for lithium-ion batteries.

  12. Ion-radical intermediates of the radiation-chemical transformations of organic carbonates

    Science.gov (United States)

    Shiryaeva, Ekaterina S.; Sosulin, Ilya S.; Saenko, Elizaveta V.; Feldman, Vladimir I.

    2016-07-01

    The spectral features and reactions of ion-radical intermediates produced from organic carbonates in low-temperature matrices were investigated by EPR spectroscopy and quantum-chemical calculations. It was shown that radical cations of diethyl carbonate and dimethyl carbonate underwent intramolecular hydrogen transfer to yield alkyl-type species, as was suggested previously. Meanwhile, radical cation of EC demonstrates a ring cleavage even at 77 K, while radical cation of PC is probably intrinsically stable and undergo an ion-molecule reaction with a neighboring neutral molecule in dimers or associates. Radical anions were obtained in glassy matrices of diethyl ether or perdeuteroethanol. The radical anions of linear carbonates show photoinduced fragmentation to yield the corresponding alkyl radicals; such process may also occur directly under radiolysis. Radical anions of cyclic carbonates are relatively stable and yield only trace amounts of fragmentation products under similar conditions.

  13. 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.

  14. Li-ion capacitors with carbon cathode and hard carbon/stabilized lithium metal powder anode electrodes

    Science.gov (United States)

    Cao, W. J.; Zheng, J. P.

    2012-09-01

    A lithium-ion capacitor was developed using a mixture of stabilized lithium metal powder and hard carbon as the anode electrode, while activated carbon was used as the cathode. A specific energy of approximately 82 Wh kg-1 was obtained based on the weight of electrode materials; however, when the electrolyte, separator, and current collectors were included, the specific energy of an assembled Li-ion capacitor was about 25 Wh kg-1. The capacitor was able to deliver over 60% of the maximum energy at a discharge C-rate of 44C. Through continuous galvanostatic charge/discharge cycling, the capacitance of the Li-ion capacitor degraded less than 3% over 600 cycles.

  15. Advanced carbon materials/olivine LiFePO4 composites cathode for lithium ion batteries

    Science.gov (United States)

    Gong, Chunli; Xue, Zhigang; Wen, Sheng; Ye, Yunsheng; Xie, Xiaolin

    2016-06-01

    In the past two decades, LiFePO4 has undoubtly become a competitive candidate for the cathode material of the next-generation LIBs due to its abundant resources, low toxicity and excellent thermal stability, etc. However, the poor electronic conductivity as well as low lithium ion diffusion rate are the two major drawbacks for the commercial applications of LiFePO4 especially in the power energy field. The introduction of highly graphitized advanced carbon materials, which also possess high electronic conductivity, superior specific surface area and excellent structural stability, into LiFePO4 offers a better way to resolve the issue of limited rate performance caused by the two obstacles when compared with traditional carbon materials. In this review, we focus on advanced carbon materials such as one-dimensional (1D) carbon (carbon nanotubes and carbon fibers), two-dimensional (2D) carbon (graphene, graphene oxide and reduced graphene oxide) and three-dimensional (3D) carbon (carbon nanotubes array and 3D graphene skeleton), modified LiFePO4 for high power lithium ion batteries. The preparation strategies, structure, and electrochemical performance of advanced carbon/LiFePO4 composite are summarized and discussed in detail. The problems encountered in its application and the future development of this composite are also discussed.

  16. Influence of bicarbonate and carbonate ions on sonochemical degradation of Rhodamine B in aqueous phase.

    Science.gov (United States)

    Merouani, Slimane; Hamdaoui, Oualid; Saoudi, Fethi; Chiha, Mahdi; Pétrier, Christian

    2010-03-15

    The influence of bicarbonate and carbonate ions on sonolytic degradation of cationic dye, Rhodamine B (RhB), in water was investigated. As a consequence of ultrasonic cavitation that generates .OH radicals, carbonate radicals were secondary products of water sonochemistry when it contains dissolved bicarbonate or carbonate ions. The results clearly demonstrated the significant intensification of sonolytic destruction of RhB in the presence of bicarbonate and carbonate, especially at lower dye concentrations. Degradation intensification occurs because carbonate radicals sonochemically formed undergo radical-radical recombination at a lesser extent than hydroxyl radicals. The generated carbonate radicals are likely able to migrate far from the cavitation bubbles towards the solution bulk and are suitable for degradation of an organic dye such as RhB. Therefore, at low dye concentrations, carbonate radical presents a more selective reactivity towards RhB molecules than hydroxyl radical. In the presence of bicarbonate, degradation rate reached a maximum at 3 g L(-1) bicarbonate, but subsequent addition retards the destruction process. In RhB solutions containing carbonate, the oxidation rate gradually increased with increasing carbonate concentration up to 10 g L(-1) and slightly decreased afterward. Carbonate radicals sonochemically generated are suitable for total removal of COD of sonicated RhB solutions. PMID:19910116

  17. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accclerated carbon ions with linear energy transfers of 125.5, 200 and 700 keV/μm were measured, respectively. Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves. They are 7.86±0.17, 10.44±1.11 and 32.32±3.58 μm2 in turn. With the surviving response of V79 cells to 60Co γ-rays as a reference value, relative biological effectiveness at 10%, 20%, 50% and 80% survival levels were given for the accelerated carbon ions. The results showed that carbon ions with LET of 125.5 keV/μm had a higher value of RBE at all the four survival levels than the carbon ions with other LETs. It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200 keV/μm for carbon ions.

  18. The Experimental Measurement of the Relative Biological Effectiveness of Carbon Ions with Different Qualities

    Institute of Scientific and Technical Information of China (English)

    WANG Jufang; LI Wenjian

    2008-01-01

    The relative biological effectiveness (RBE) of carbon ions with linear energy transfer (LET) of 172 keV/μm and 13.7 keV/μm were determined in this study. The clonogenic survival and premature terminal differentiation were measured on normal human fibroblasts AG01522C and NHDF after exposure of the cells to 250 kV X-rays and carbon ions with different qualities. RBE was determined for these two biological end points. The results showed that the measured RBE10 with a survival fraction of 10% was 3.2 for LET 172 keV/μm, and 1.33 for LET 13.7 keV/μm carbon ions. RBE for a doubling of post-mitotic fibroblasts (PMF) in the population was 2.8 for LET 172 keV/μm, and 1 for LET 13.7 keV/μm carbon ions. For the carbon ion therapy, a high RBE value on the Bragg peak results in a high biological dose on the tumour. The tumour cells can be killed effectively. At the same time, the dose on healthy tissue would be reduced accordingly. This will lighten the late effect such as fibrosis on normal tissue.

  19. Killing effect of Chinese hamster V79 cells exposed to accelerated carbon ions and RBE determination

    Institute of Scientific and Technical Information of China (English)

    LIQiang; ZHOUGuang-Ming; 等

    2002-01-01

    Survival curves of Chinese hamster V79 cells exposed to accelerated carbon ions with linear energy transfers of 125.5,200 and 700keV/um were measured,respectively,Inactivation cross sections corresponding to the irradiation above were deduced from the V79 cell survival curves.They are 7.86±0.17,10.44±1.11 and 32.32±3.59um2 in turn.With the surviving response of V79 cells to 60Co γ-rays as a reference value,relative biological effectiveness at 10%,20%,50%and 80% survival levels were given for the accelerated carbon ions,The results showed that carbon ions with LET of 125.5keV/um had a higher value of RBE at all the four survival levels than the carbon ions with other LETs.It was prompted that the maximum value of RBE for the V79 cell surviving as the biological endpoint emerged at the LET below 200keV/um for carbon ions.

  20. Experience With Carbon Ion Radiotherapy for WHO Grade 2 Diffuse Astrocytomas

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Azusa [Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba (Japan); Mizoe, Jun-Etsu, E-mail: junetsumizoe@gmail.com [Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba (Japan); Tsujii, Hirohiko; Kamada, Tadashi; Jingu, Keiichi [Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba (Japan); Iwadate, Yasuo [Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chiba (Japan); Nakazato, Youichi [Department of Human Pathology, Gunma University Graduate School of Medicine, Gunma (Japan); Matsutani, Masao [Department of Neurological Surgery, Saitama Medical University, Saitama (Japan); Takakura, Kintomo [Department of Neurological Surgery, Tokyo Women' s Medical University, Tokyo (Japan)

    2012-05-01

    Purpose: To assess outcomes of carbon ion radiotherapy for diffuse astrocytomas in adults. Methods and Materials: Between October 1994 and February 2002, 14 patients with diffuse astrocytoma, identified as eligible for carbon ion radiotherapy, were enrolled in a phase I/II clinical trial. Carbon ion radiotherapy was administered in 24 fractions over 6 weeks. The normal tissue morbidity was monitored carefully, and the carbon ion dose was escalated from 50.4 Gy equivalent (GyE) to 55.2 GyE. Patients were divided into two groups according to their carbon ion doses: a low-dose group in which 2 patients were irradiated with 46.2 GyE and 7 patients were irradiated with 50.4 GyE, and a high-dose group in which 5 patients were irradiated with 55.2 GyE. Results: Toxicities were within acceptable limits, and none of the patients developed Grade 3 or higher acute or late reactions. The median progression-free survival (PFS) time was 18 months for the low-dose group and 91 months for the high-dose group (p = 0.0030). The median overall survival (OS) time was 28 months for the low-dose group and not reached for the high-dose group (p = 0.0208). Conclusion: High-dose group patients showed significant improvement in PFS and OS rates compared to those in the low-dose group, and both dose groups showed acceptable toxicity.

  1. Experience With Carbon Ion Radiotherapy for WHO Grade 2 Diffuse Astrocytomas

    International Nuclear Information System (INIS)

    Purpose: To assess outcomes of carbon ion radiotherapy for diffuse astrocytomas in adults. Methods and Materials: Between October 1994 and February 2002, 14 patients with diffuse astrocytoma, identified as eligible for carbon ion radiotherapy, were enrolled in a phase I/II clinical trial. Carbon ion radiotherapy was administered in 24 fractions over 6 weeks. The normal tissue morbidity was monitored carefully, and the carbon ion dose was escalated from 50.4 Gy equivalent (GyE) to 55.2 GyE. Patients were divided into two groups according to their carbon ion doses: a low-dose group in which 2 patients were irradiated with 46.2 GyE and 7 patients were irradiated with 50.4 GyE, and a high-dose group in which 5 patients were irradiated with 55.2 GyE. Results: Toxicities were within acceptable limits, and none of the patients developed Grade 3 or higher acute or late reactions. The median progression-free survival (PFS) time was 18 months for the low-dose group and 91 months for the high-dose group (p = 0.0030). The median overall survival (OS) time was 28 months for the low-dose group and not reached for the high-dose group (p = 0.0208). Conclusion: High-dose group patients showed significant improvement in PFS and OS rates compared to those in the low-dose group, and both dose groups showed acceptable toxicity.

  2. Dosimetry service removal

    CERN Multimedia

    Safety Commission

    2010-01-01

    Dear personal dosimeter user, Please note that the Dosimetry service has moved in building 55, the service is now located in the main floor: 55-R-004. Main floor instead of second floor. On your right hand when accessing in the building. Thank you Dosimetry Service

  3. Dosimetry in process control

    International Nuclear Information System (INIS)

    Measurement of absorbed dose and dose distribution in irradiated medical products relies on the use of quality dosimetry systems, trained personnel and a thorough understanding of the energy deposition process. The interrelationship of these factors will be discussed with emphasis on the current and future practices of process control dosimetry. (author)

  4. Dosimetry of Low-Energy Beta Radiation

    DEFF Research Database (Denmark)

    Borg, Jette

    Useful techniques and procedures for derermination of absorbed doses from exposure in a low-energy beta radiation were studied and evaluated. The four techniques included were beta spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical...... low-energy beta radiation field a moderated spectrum from a carbon-14 source was used. The measured responce of a Si(Li) detector to photons (bremsstrahlung) showed fine agreemant with the MC calculated photon response, whereas the difference between measured and MC calculated response to electrons...

  5. Ion-implanted Mechanism of the Deposition Process for Diamond-Like Carbon Films

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-Min; WU Wei-Dong; WANG Yu-Ying; WANG Hai-Ping; GE Fang-Fang; TANG Yong-Jian; JU Xin

    2011-01-01

    Due to the local densification, high-energy C and doped ions can greatly affect the bonding configurations of diamond-like carbon films. We investigate the corresponding affection of different incident ions with energy from WeV to 600eV by Monte Carlo methods. The ion-implanted mechanism called the subplantation (for C, N, O, W, Y, etc.) is confirmed. Obvious thermal effect could be induced by the subplantation of the incident ions. Further, the subplantation of C ions is proved by in situ reflection high energy electron diffraction (RHEED). The observation from an atomic force microscope (AFM) indicates that the initial implantation of C ions might result in the final primitive-cell-like morphology of the smooth film (in an area of 1.2 mm × 0.9 mm, rms roughness smaller than 20 nm by Wyko).

  6. Removal of Lead (II Ions from Aqueous Solutions onto Activated Carbon Derived from Waste Biomass

    Directory of Open Access Journals (Sweden)

    Murat Erdem

    2013-01-01

    Full Text Available The removal of lead (II ions from aqueous solutions was carried out using an activated carbon prepared from a waste biomass. The effects of various parameters such as pH, contact time, initial concentration of lead (II ions, and temperature on the adsorption process were investigated. Energy Dispersive X-Ray Spectroscopy (EDS analysis after adsorption reveals the accumulation of lead (II ions onto activated carbon. The Langmuir and Freundlich isotherm models were applied to analyze equilibrium data. The maximum monolayer adsorption capacity of activated carbon was found to be 476.2 mg g−1. The kinetic data were evaluated and the pseudo-second-order equation provided the best correlation. Thermodynamic parameters suggest that the adsorption process is endothermic and spontaneous.

  7. Swift heavy ion irradiation of metal containing tetrahedral amorphous carbon films

    Science.gov (United States)

    Karaseov, P. A.; Protopopova, V. S.; Karabeshkin, K. V.; Shubina, E. N.; Mishin, M. V.; Koskinen, J.; Mohapatra, S.; Tripathi, A.; Avasthi, D. K.; Titov, A. I.

    2016-07-01

    Thin carbon films were grown at room temperature on (0 0 1) n-Si substrate using dual cathode filtered vacuum arc deposition system. Graphite was used as a source of carbon atoms and separate metallic electrode was simultaneously utilized to introduce Ni or Cu atoms. Films were irradiated by 100 MeV Ag7+ ions to fluences in the range 1 × 1010-3 × 1011 cm-2. Rutherford backscattering spectroscopy, Raman scattering, scanning electron microscopy and atomic force microscopy in conductive mode were used to investigate film properties and structure change under irradiation. Some conductive channels having metallic conductivity type were found in the films. Number of such channels is less than number of impinged ions. Presence of Ni and Cu atoms increases conductivity of those conductive channels. Fluence dependence of all properties studied suggests different mechanisms of swift heavy ion irradiation-induced transformation of carbon matrix due to different chemical effect of nickel and copper atoms.

  8. 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...

  9. 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.

  10. 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

    Directory of Open Access Journals (Sweden)

    Jensen Alexandra D

    2012-03-01

    Full Text Available Abstract 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.

  11. 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

    International Nuclear Information System (INIS)

    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

  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. Coupled, Nitrogen, Oxygen, Carbon and Ion Chemistry on Titan

    Science.gov (United States)

    Yelle, Roger; Vuitton, Veronique; Lavvas, Panayotis; Klippenstein, Stephen; Horst, Sarah

    2016-06-01

    We present simulations of the coupled nitrogen, oxygen, and ion chemistry on Titan using a state-of-the-art photochemical model. The model is one dimensional and extends from the surface to the exobase. The chemistry linking 160 neutral species and 172 ion species is described through networks including 1139 neutral reactions and 4361 ion reactions. UV photolysis of 59 species is included as well as dissociation and ionization of 16 species due to suprathermal electrons. Reaction rate coefficients are obtained from a thorough review of the literature supplemented by calculations of rates of important reactions when laboratory values are not available. Comparison of the model with available observational constraints helps to determine the fundamental chemical pathways in the atmosphere. We will discuss in particular the importance of recent measurements of HNC, HC15N, CO2, and H2O and the role of ion chemistry in the synthesis of neutral species. Key reactions that require further laboratory of theoretical study will be identified.

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

    International Nuclear Information System (INIS)

    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 (RBE10) 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

  15. Influence of anodic surface treatment of activated carbon on adsorption and ion exchange properties

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Kim, K.D.

    1999-10-01

    The effect of anodic surface treatment of activated carbon on adsorption and ion exchange characteristics was investigated in the condition of 35 wt% NaOH electrolyte for 60 s. The acid and base values were determined by a titration technique, and surface and pore structures were studied in terms of BET volumetric measurement with N{sub 2} adsorption. The ion exchange capacity of the anodized activated carbons was characterized by a dry weight capacity technique. It was observed that an increase in current intensity leads to an increase in the surface functional groups of activated carbons, resulting in increasing pH, acid-base values, and anion-cation exchange capacities, without significant change of surface and pore structures (i.e., specific surface area, total pore volume, micropore volume, and average pore diameter). Also, anodically treated activated carbons are more effectively evaluated on the base value or cation exchange capacity than on the oppose properties in this electrolytic system.

  16. The Anion Effect on Li(+) Ion Coordination Structure in Ethylene Carbonate Solutions.

    Science.gov (United States)

    Jiang, Bo; Ponnuchamy, Veerapandian; Shen, Yuneng; Yang, Xueming; Yuan, Kaijun; Vetere, Valentina; Mossa, Stefano; Skarmoutsos, Ioannis; Zhang, Yufan; Zheng, Junrong

    2016-09-15

    Rechargeable lithium ion batteries are an attractive alternative power source for a wide variety of applications. To optimize their performances, a complete description of the solvation properties of the ion in the electrolyte is crucial. A comprehensive understanding at the nanoscale of the solvation structure of lithium ions in nonaqueous carbonate electrolytes is, however, still unclear. We have measured by femtosecond vibrational spectroscopy the orientational correlation time of the CO stretching mode of Li(+)-bound and Li(+)-unbound ethylene carbonate molecules, in LiBF4, LiPF6, and LiClO4 ethylene carbonate solutions with different concentrations. Surprisingly, we have found that the coordination number of ethylene carbonate in the first solvation shell of Li(+) is only two, in all solutions with concentrations higher than 0.5 M. Density functional theory calculations indicate that the presence of anions in the first coordination shell modifies the generally accepted tetrahedral structure of the complex, allowing only two EC molecules to coordinate to Li(+) directly. Our results demonstrate for the first time, to the best of our knowledge, the anion influence on the overall structure of the first solvation shell of the Li(+) ion. The formation of such a cation/solvent/anion complex provides a rational explanation for the ionic conductivity drop of lithium/carbonate electrolyte solutions at high concentrations.

  17. Two-Dimensional Porous Carbon: Synthesis and Ion-Transport Properties.

    Science.gov (United States)

    Zheng, Xiaoyu; Luo, Jiayan; Lv, Wei; Wang, Da-Wei; Yang, Quan-Hong

    2015-09-23

    Their chemical stability, high specific surface area, and electric conductivity enable porous carbon materials to be the most commonly used electrode materials for electrochemical capacitors (also known as supercapacitors). To further increase the energy and power density, engineering of the pore structures with a higher electrochemical accessible surface area, faster ion-transport path and a more-robust interface with the electrolyte is widely investigated. Compared with traditional porous carbons, two-dimensional (2D) porous carbon sheets with an interlinked hierarchical porous structure are a good candidate for supercapacitors due to their advantages in high aspect ratio for electrode packing and electron transport, hierarchical pore structures for ion transport, and short ion-transport length. Recent progress on the synthesis of 2D porous carbons is reported here, along with the improved electrochemical behavior due to enhanced ion transport. Challenges for the controlled preparation of 2D porous carbons with desired properties are also discussed; these require precise tuning of the hierarchical structure and a clarification of the formation mechanisms. PMID:26207982

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

    International Nuclear Information System (INIS)

    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)

  19. Ferrous ion oxidation by Thiobacillus ferrooxidans immobilized on activated carbon

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ji-kui; QIN Wen-qing; NIU Yin-jian; LI Hua-xia

    2006-01-01

    The immobilization of Thiobacillus ferrooxidans on the activated carbon particles as support matrix was investigated. Cycling batch operation results in the complete oxidation of ferrous iron in 8 d when the modified 9 K medium is set to flow through the mini-bioreactor at a rate of 0.104 L/h at 25 ℃. The oxidation rate of ferrous iron with immobilized T. ferrooxidans is 9.38 g/(L·h). The results show that the immobilization of T. ferrooxidans on activated carbon can improve the rate of oxidation of ferrous iron. The SEM images show that a build-up of cells of T. ferrooxidans and iron precipitates is formed on the surface of activated carbon particles.

  20. 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.

  1. Highly stable linear carbonate-containing electrolytes with fluoroethylene carbonate for high-performance cathodes in sodium-ion batteries

    Science.gov (United States)

    Lee, Yongwon; Lee, Jaegi; Kim, Hyungsub; Kang, Kisuk; Choi, Nam-Soon

    2016-07-01

    Employing linear carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) as electrolyte solvents provides an opportunity to design appropriate electrolyte systems for high-performance sodium-ion batteries (SIBs). However, in practice, the use of linear carbonate-containing electrolytes is quite challenging because linear carbonates readily decompose at Na metal electrodes or sodiated anodes. One of the promising approaches is using an electrolyte additive to resolve the critical problems related to linear carbonates. Our investigation reveals that remarkable enhancement in electrochemical performance of Na4Fe3(PO4)2(P2O7) cathodes with linear carbonate-containing electrolytes is achieved by using a fluoroethylene carbonate (FEC) additive. Importantly, the initial Coulombic efficiency of the Na deposition/stripping on a stainless steel (SS) electrode is drastically improved from 16% to 90% by introducing the FEC additive into ethylene carbonate (EC)/propylene carbonate (PC)/DEC (5/3/2, v/v/v)/0.5 M NaClO4. The underlying mechanism of FEC at the electrode-electrolyte interface is clearly demonstrated by 13C nuclear magnetic resonance (NMR). In addition, the Na4Fe3(PO4)2(P2O7) cathode in EC/PC/DEC (5/3/2, v/v/v)/0.5 M sodium perchlorate (NaClO4) with FEC delivers a discharge capacity of 90.5 mAh g-1 at a current rate of C/2 and exhibits excellent capacity retention of 97.5% with high Coulombic efficiency of 99.6% after 300 cycles at 30 °C.

  2. 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.

  3. Metal ion binding with carbon nanotubes and graphene: Effect of chirality and curvature

    Science.gov (United States)

    Umadevi, Deivasigamani; Sastry, G. Narahari

    2012-10-01

    First principles calculations have been used to comprehensively study the binding of a series alkali (Li+, Na+, K+) and alkaline earth (Be2+, Mg2+, Ca2+) metal ions with carbon nanotubes (CNTs) and graphene. It is interesting to note that the mono-cationic systems prefer binding to armchair CNTs over zigzag CNTs, while the preference for the di-cationic systems is exactly opposite. We have also observed significant changes in the HOMO-LUMO energy gap of the CNTs on metal ion binding and these results indicate that the fine tuning of energy gap of the CNTs can be effected through metal ion binding.

  4. Thermal management of a Li-ion battery using carbon fiber-PCM composites

    International Nuclear Information System (INIS)

    A combination of latent and sensible heat capabilities has made phase change materials (PCMs) very useful in a variety of heat transfer applications. The main purpose of using the phase change material in lithium-ion (Li-ion) battery thermal management systems (BTMs) is to mitigate the excessive temperature rise in the cells and to create uniform temperature distribution within the battery pack. In this work, carbon fibers were added to a PCM to enhance its heat transfer potentials. Various strategies were adopted to manage temperature distribution around a single AA-battery-like simulator. The effects of carbon fiber size and weight percent within the PCM on thermal performance were studied. Experimental results have indicated that a mixture of PCM with 2-mm-long carbon fibers and mass percentage of 0.46% showed the best thermal performance for which the maximum temperature rise in the battery simulator can be reduced by up to 45%. - Graphical abstract: The schematic of the experimental setup and data acquisition system (1-power source 2-container 3-battery module 4-thermocouples 5-temperature indicator 6-data acquisition system). - Highlights: • Thermal performance of a Li-ion battery simulator is studied in the presence of PCM. • The effect of carbon fiber on heat transfer enhancement is examined. • Better thermal management can be achieved by the presence of carbon fiber in PCM. • Both carbon fiber mass fraction and length play crucial role in thermal management

  5. 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.

  6. Adsorption of rare earth ions using carbonized polydopamine nano carbon shells

    Institute of Scientific and Technical Information of China (English)

    孙晓琦; LUO Huimin; Shannon M. Mahurin; LIU Rui; HOU Xisen; DAI Sheng

    2016-01-01

    Herein we reported the structure effects of carbon nano-shells prepared by the carbonization of polydopamine for the ad-sorption of rare earth elements (REEs) for the first time. Solid carbon spheres, 60 nm carbon shells and 500 nm carbon shells were prepared and evaluated for adsorption and desorption of REEs. The adsorption performance of carbon nano-shells for REEs was far superior to the solid carbon spheres. In addition, the effect of acidity on the adsorption and desorption properties was discussed. The good adsorption performance of the carbon nano-shells could be attributed to their pore structure, specific surface area, and the pres-ence of both amine and carbonyl groups from the grafted dopamine.

  7. 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

  8. 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

  9. Ion implanted pyrolitic carbon for the hip prosthesis

    International Nuclear Information System (INIS)

    Full text: Hip joint arthroplasty is a successful surgical procedure, but loosening induced by polyethylene wear debris continues to be a problem. Fine grained isotropic graphite (POCO ZXF-5Q) coated with Pyrolite (trademark of Carbomedics Inc.) combines biocompatibility, strength and tribological properties which could be utilised in a hip prosthesis. Some preliminary work has been conducted on this material, and the effect nitrogen ion implantation has on its wear resistance. Finite element analysis was conducted on a femoral head of a canine hip prosthesis with diameter 19mm made from POCO ZXF-5Q . An optimum design was obtained after design variables such as taper angle and width, internal recess radius, crown thickness were varied so that internal stresses were minimised. This was then translated into an human sized femoral head with diameter 28mm, which was subjected to mechanical testing. Loading was at 20 deg C to the taper, with loading rate 10kN/s used in static loading, whilst fatigue testing was carried out between 300 - 3000N at 30Hz for 107 cycles. Pin-on-disc wear testing was carried out using a CSEM Tribometer. A 1N load was applied to 6mm diameter pins. Wear track radii were 11 and 13mm, with linear velocity 5cm/s and sliding distance 2.5km. Test temperature was 37±1degC with Ringer solution and bovine serum being used as lubricant. Nitrogen implanted samples were irradiated to a dose of 5x1016 ions.cm-2 at 50keV. Static testing was carried out to loads of 8000N and all five POCO ZXF-5Q femoral heads tested survived. Then three of these pre-tested femoral heads were subjected to fatigue testing and no failures occured before 107 cycles. Wear was reduced by nitrogen ion implantation only when an irradiated pin was tested against as polished Pyrolite. Nitrogen ion implanted Pyrolite on a POCO ZXF-5Q substrate may have clinical potential. The substrate has appropriate mechanical properties, and nitrogen ion implantation can improve the already

  10. Selective removal of nitrate ion using a novel composite carbon electrode in capacitive deionization.

    Science.gov (United States)

    Kim, Yu-Jin; Choi, Jae-Hwan

    2012-11-15

    We fabricated nitrate-selective composite carbon electrodes (NSCCEs) for use in capacitive deionization to remove nitrate ions selectively from a solution containing a mixture of anions. The NSCCE was fabricated by coating the surface of a carbon electrode with the anion exchange resin, BHP55, after grinding the resin into fine powder. BHP55 is known to be selective for nitrate ions. We performed desalination experiments on a solution containing 5.0 mM NaCl and 2.0 mM NaNO(3) using the NSCCE system constructed with the fabricated electrode. The selective removal of nitrate in the NSCCE system was compared to a membrane capacitive deionization (MCDI) system constructed with ion exchange membranes and carbon electrodes. The total quantity of chloride and nitrate ions adsorbed onto the unit area of the electrode in the MCDI system was 25 mmol/m(2) at a cell potential of 1.0 V. The adsorption of nitrate ions was 8.3 mmol/m(2), accounting for 33% of the total. In contrast, the total anion adsorption in the NSCCE system was 34 mmol/m(2), 36% greater than the total anion adsorption of the MCDI system. The adsorption of nitrate ions was 19 mmol/m(2), 2.3-times greater than the adsorption in the MCDI system. These results showed that the ions were initially adsorbed by an electrostatic force, and the ion exchange reactions then occurred between the resin powder in the coated layer and the solution containing mixed anions. PMID:22980574

  11. Field—ion microscopy observation of single—walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    张兆祥; 顾镇南; 等

    2002-01-01

    Field-ion microscopy(FIM),a tool for surface analysis with atomic resolution,has been employed to observe the end structure of single-walled carbon nanotubes(SWCNTs).FIM images revealed the existence of open SWCNT ends,Amorphous carbon atoms were also observed to occur around SWCNTs and traditional field evaporation failed to remove them.Heat treatment was found to be efficacious in altering the end structures of SWCNT bundles.Carbon and oxygen atoms released from heated tungsten filament are believed to be responsible for the decoration imposed on the SWCNT ends.

  12. 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

    2015-03-01

    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. PMID:25648453

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

    NARCIS (Netherlands)

    van Goethem, Marc-Jan; Niemantsverdriet, Maarten; Brandenburg, Sytze; Langendijk, Johannes A.; Coppes, Robert P.; van Luijk, Peter

    2011-01-01

    Purpose: Compared to photons, using particle radiation in radiotherapy reduces the dose and irradiated volume of normal tissues, potentially reducing side effects. The biological effect of dose deposited by particles such as carbon ions, however, differs from that of dose deposited by photons. The i

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

    International Nuclear Information System (INIS)

    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 and G4QMD are benchmarked together with some recently enhanced de-excitation models. For non-differential quantities, discrepancies of some tens of percent are found for both codes. For differential quantities, even larger deviations are found. Implications of these findings for the therapeutic use of carbon ions are discussed.

  15. The effects of high-voltage pulse electric discharges on ion adsorption on activated carbons

    Science.gov (United States)

    Gafurov, M. M.; Sveshnikova, D. A.; Larin, S. V.; Rabadanov, K. Sh.; Shabanova, Z. E.; Yusupova, A. A.; Ramazanov, A. Sh.

    2008-07-01

    The effects of high-voltage pulse electric discharges (HPED) on sorption of boron and sulfate ions on activated carbons of different kinds (KM-2, BAU, DAK) were investigated. The effect of HPED activation on the sorption characteristics of the systems was found to be similar to the temperature effect.

  16. Interfacial electrical properties of ion-beam sputter deposited amorphous carbon on silicon

    Science.gov (United States)

    Khan, A. A.; Woollam, J. A.; Chung, Y.; Banks, B.

    1983-01-01

    Amorphous, 'diamond-like' carbon films have been deposited on Si substrates, using ion-beam sputtering. The interfacial properties are studied using capacitance and conductance measurements. Data are analyzed using existing theories for interfacial electrical properties. The density of electronic states at the interface, along with corresponding time constants are determined.

  17. Cancer stem cells: The potential of carbon ion beam radiation and new radiosensitizers (Review).

    Science.gov (United States)

    Baek, Sung-Jae; Ishii, Hideshi; Tamari, Keisuke; Hayashi, Kazuhiko; Nishida, Naohiro; Konno, Masamitsu; Kawamoto, Koichi; Koseki, Jun; Fukusumi, Takahito; Hasegawa, Shinichiro; Ogawa, Hisataka; Hamabe, Atsushi; Miyo, Masaaki; Noguchi, Kozo; Seo, Yuji; Doki, Yuichiro; Mori, Masaki; Ogawa, Kazuhiko

    2015-11-01

    Cancer stem cells (CSCs) are a small population of cells in cancer with stem-like properties such as cell proliferation, multiple differentiation and tumor initiation capacities. CSCs are therapy-resistant and cause cancer metastasis and recurrence. One key issue in cancer therapy is how to target and eliminate CSCs, in order to cure cancer completely without relapse and metastasis. To target CSCs, many cell surface markers, DNAs and microRNAs are considered as CSC markers. To date, the majority of the reported markers are not very specific to CSCs and are also present in non-CSCs. However, the combination of several markers is quite valuable for identifying and targeting CSCs, although more specific identification methods are needed. While CSCs are considered as critical therapeutic targets, useful treatment methods remain to be established. Epigenetic gene regulators, microRNAs, are associated with tumor initiation and progression. MicroRNAs have been recently considered as promising therapeutic targets, which can alter the therapeutic resistance of CSCs through epigenetic modification. Moreover, carbon ion beam radiotherapy is a promising treatment for CSCs. Evidence indicates that the carbon ion beam is more effective against CSCs than the conventional X-ray beam. Combination therapies of radiosensitizing microRNAs and carbon ion beam radiotherapy may be a promising cancer strategy. This review focuses on the identification and treatment resistance of CSCs and the potential of microRNAs as new radiosensitizers and carbon ion beam radiotherapy as a promising therapeutic strategy against CSCs. PMID:26330103

  18. 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.

  19. Effects of main traits of sweet sorghum irradiated by carbon ions

    International Nuclear Information System (INIS)

    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 12C+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)

  20. A carbon cluster ion source for mass calibration at TRIGA-TRAP

    International Nuclear Information System (INIS)

    TRIGA-TRAP is a high-precision penning trap mass spectrometer installed at the research reactor TRIGA Mainz in order to determine the masses of short-lived fission products and - in addition to that - also the masses of actinide elements ranging from uranium up to californium. In order to determine precisely the masses of the nuclides of interest, the superconducting magnet providing the strong magnetic field for the Penning trap has to be calibrated by measuring the cyclotron frequency of an ion with well-known mass, which is, if possible, an isobaric nuclide of the ion of interest. Therefore, the best possible choice for mass calibration is to use carbon clusters as mass references, as demonstrated at the ISOLTRAP facility at ISOLDE/CERN. A laser ablation ion source for the production of carbon clusters has been developed using a frequency-doubled Nd:YAG laser. The design, current status, and results of the production of carbon cluster ions, using C60 and Sigradure registered samples, as well as other ions are presented

  1. Alternate dipping preparation of biomimetic apatite layers in the presence of carbonate ions

    International Nuclear Information System (INIS)

    The classical simulated body fluids method cannot be employed to prepare biomimetic apatites encompassing metallic ions that lead to very stable phosphates. This is the case for heavy metals such as uranium, whose presence in bone mineral after contamination deserves toxicological study. We have demonstrated that existing methods, based on alternate dipping into calcium and phosphate ions solutions, can be adapted to achieve this aim. We have also especially studied the impact of the presence of carbonate ions in the medium as these are necessary to avoid hydrolysis of the contaminating metallic cations. Both the apatite–collagen complex method and a standard chemical (STD) method employing only mineral solutions lead to biomimetic apatites when calcium and carbonate ions are introduced simultaneously. The obtained materials were fully characterized and we established that the STD method tolerates the presence of carbonate ions much better, and this leads to homogeneous samples. Emphasis was set on the repeatability of the method to ensure the relevancy of further work performed on series of samples. Finally, osteoblasts cultured on these samples also proved a similar yield and standard-deviation in their adenosine triphosphate content when compared to commercially available substrates designed to study of such cell cultures. (paper)

  2. 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.

  3. Geant4 Simulation Study of Dose Distribution and Energy Straggling for Proton and Carbon Ion Beams in Water

    Directory of Open Access Journals (Sweden)

    Zhao Qiang

    2016-01-01

    Full Text Available Dose distribution and energy straggling for proton and carbon ion beams in water are investigated by using a hadrontherapy model based on the Geant4 toolkit. By gridding water phantom in N×N×N voxels along X, Y and Z axes, irradiation dose distribution in all the voxels is calculated. Results indicate that carbon ion beams have more advantages than proton beams. Proton beams have bigger width of the Bragg peak and broader lateral dose distribution than carbon ion beams for the same position of Bragg peaks. Carbon ion has a higher local ionization density and produces more secondary electrons than proton, so carbon ion beams can achieve a higher value of relative biological effectiveness.

  4. Alanine-ESR in vivo dosimetry: a feasibility study and possible applications

    International Nuclear Information System (INIS)

    A new alanine-ESR dosimeter has been developed at AERIAL in order to study its potential use in radiotherapy. Alanine-ESR results are compared with ion chamber for depth-dose measurements. A good concordance has been found between provisional dosimetry and absorbed dose during high dose rate and intra operative treatments. The results of the experiments indicate that alanine-ESR dosimetry is suited to check dose optimisation routines and seems to be a promising in vivo dosimetry technique. (Author)

  5. Tribological properties of ion beam deposited diamond-like carbon film on silicon nitride

    International Nuclear Information System (INIS)

    The present article reports on the physical characterization and tribological properties of diamond-like carbon (DLC) films deposited on structural Si3N4 substrates. The films were deposited by the direct ion beam deposition technique. The ion beam was produced by plasma discharge of pre-mixed methane and hydrogen gas in a Kaufman-type ion source. The deposited films were found to be amorphous and contained about 70% carbon and 30% hydrogen. The friction coefficient of an uncoated Si3N4 ball on a DLC coated Si3N4 disc starts at about 0.2, then decreases rapidly to 0.1-0.15 with increasing sliding distance. Increasing humidity results in a slight increase in friction coefficient, but a significant decrease in wear factor. The wear factor for the tests at ≅60% rh (relative humidity) are about an order of magnitude smaller than the tests at 3% rh. (orig.)

  6. Adsorption of manganese(II) ions by EDTA-treated activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.Y.; Mazyck, D.W. [Jones Edmunds & Associates, Gainesville, FL (United States)

    2009-07-01

    The adsorption of manganese(II) ions from aqueous solution onto three different granular activated carbons treated with ethylenediamine tetraacetic acid (EDTA) and its sodium salt was investigated. Characterization of the chelate-treated carbons showed that EDTA altered the physical and chemical properties of the sorbents relative to their untreated counterparts. Furthermore, the modified sorbents exhibited a heightened capacity towards the adsorption of Mn(II) ions from aqueous media. Manganese(II) ion removal increased from 0 to 6.5 mg/g for the lignite coal-based sorbent, from 3.5 to 14.7 mg/g for the wood-based sorbent and from 1.3 to 7.9 mg/g for the bituminous coal-based sorbent. The increased removal is attributed, in part, to the creation of Lewis base sites that participate in covalent interactions and hydrolysis reactions.

  7. Electrosorptive desalination by carbon nanotubes and nanofibres electrodes and ion-exchange membranes.

    Science.gov (United States)

    Li, Haibo; Gao, Yang; Pan, Likun; Zhang, Yanping; Chen, Yiwei; Sun, Zhuo

    2008-12-01

    A novel membrane capacitive deionization (MCDI) device, integrating both the advantages of carbon nanotubes and carbon nanofibers (CNTs-CNFs) composite film and ion-exchange membrane, was proposed with high removal efficiency, low energy consumption and low cost. The CNTs-CNFs film was synthesized by low pressure and low temperature thermal chemical vapor deposition. Several experiments were conducted to compare desalination performance of MCDI with capacitive deionization (CDI), showing that salt removal of the MCDI system was 49.2% higher than that of the CDI system. The electrosorption isotherms of MCDI and CDI show both of them follow Langmuir adsorption, indicating no change in adsorption behavior when ion-exchange membranes are introduced into CDI system. The better desalination performance of MCDI than that of CDI is due to the minimized ion desorption during electrosorption. PMID:18929385

  8. Swift carbon ion irradiated Nd:YAG ceramic optical waveguide amplifier.

    Science.gov (United States)

    Tan, Yang; Luan, Qingfang; Liu, Fengqin; Akhmadaliev, Shavkat; Zhou, Shengqiang; Chen, Feng

    2013-06-17

    A high-gain optical waveguide amplifier has been realized in a channel waveguide platform of Nd:YAG ceramic produced by swift carbon ion irradiation with metal masking. The waveguide is single mode at wavelength of 810 and 1064 nm, and with the enhanced fluorescence intensity at around 1064 nm due to the Nd(3+) ion emissions. In conjunction with the low propagation loss of the waveguide, about 26.3 dB/cm of the small signal gain at 1064 nm is achieved with an 18 ns pulse laser as the seeder under the 810-nm laser excitation. This work suggests the carbon ion irradiated Nd:YAG waveguides could serve as efficient integrated amplifiers for the signal amplification. PMID:23787589

  9. Hydronium-dominated ion transport in carbon-dioxide-saturated electrolytes at low salt concentrations in nanochannels

    DEFF Research Database (Denmark)

    Lund Jensen, Kristian; Kristensen, Jesper Toft; Crumrine, Andrew Michael;

    2011-01-01

    Nanochannel ion transport is known to be governed by surface charge at low ionic concentrations. In this paper, we show that this surface charge is typically dominated by hydronium ions arising from dissolution of ambient atmospheric carbon dioxide. Taking the hydronium ions into account, we model...

  10. 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

  11. Kinetic-Energy Distributions of Positive and Negative Ions in DC Townsend Discharges of Carbon Dioxide

    Science.gov (United States)

    Rao, M. V. V. S.; van Brunt, R. J.; Olthoff, J. K.

    1997-10-01

    Ion kinetic-energy distributions (IEDs), mean energies, and relative abundances are measured for CO_2^+, CO^+, O_2^+, O^+, C^+, and O^- ions produced in dc Townsend discharges in pure carbon dioxide. The discharges are generated at electric field-to-gas density ratios (E/N) ranging from 3.5 x 10-18 Vm^2 to 20 x 10-18 Vm^2 (3.5 to 20 kTd). Ions sampled from the discharge through a small orifice in the center of the grounded electrode were energy and mass analyzed by an electrostatic energy analyzer attached to a quadrupole mass spectrometer.(M. V. V. S. Rao, R. J. Van Brunt, and J. K. Olthoff, Phys. Rev. E 54), 5641 (1996) In the present experiments, CO_2^+ was determined to be the dominant positive ion (greater than 85%) at all E/N. The IEDs of CO_2^+, O_2^+, and O^+ are Maxwellian at all E/N, with CO^+ exhibiting non-Maxwellian behavior above 10 kTd, and C^+ exhibiting non-Maxwellian behavior at all E/N. Negative ion fluxes were substantially lower than positive ion fluxes, with O^- being the only detectable negative ion. The IEDs for O^- are Maxwellian at 6 kTd and below. The fact that O^- is the only negative ion indicates that no asymmetric charge transfer exists for O^- in CO_2.

  12. Charge and Mass Effects on Low Energy Ion Channeling in Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    LI Yong; ZHENG Li-Ping; ZHANG Wei; XV Zi-Jian; REN Cui-Lan; HUAI Ping; ZHU Zhi-Yuan

    2011-01-01

    @@ Channeling phenomena of He, Ne, Ar and Kr ions at energy (200-5000eV) in single-wall carbon nanotubes (SWCNTs) are investigated by molecular dynamics simulation with analytical potentials.The critical angles for the particles to be channeled in an SWCNT are analyzed.In the incident energy range of 200-5000 eV, it is found that the ion energy dependence of the critical angle obeys an improved Lindhard equation which is closely related to the ratio of nuclear charge number to atomic mass Z/M.The critical angle for different types of ions channeling in SWCNTs is determined by both the atomic nuclear charge and mass.%Channeling phenomena of He, Ne, Ar and Kr ions at energy (200-5000eV) in single-wall carbon nanotubes (SWCNTs) are investigated by molecular dynamics simulation with analytical potentials. The critical angles for the particles to be channeled in an SWCNT are analyzed. In the incident energy range of 200-5000eV, it is found that the ion energy dependence of the critical angle obeys an improved Lindhard equation which is closely related to the ratio of nuclear charge number to atomic mass Z/M. The critical angle for different types of ions channeling in SWCNTs is determined by both the atomic nuclear charge and mass.

  13. Induction of apoptosis in murione spleen lymphocytes using carbon ion beam

    International Nuclear Information System (INIS)

    To assess the capacity of heavy ions to induce apoptosis in lymphocytes, mice have been irradiated with accelerated carbon ions (95 MeV/nucleon) at doses ranging from 0.1 to 4 Gy. Their spleens were removed 24 h later and gently dissociated to prepare a single cell suspension. Mononuclear cells were then maintained in culture at 37oC, and the occurrence of apoptosis in these cells was analysed 24 h later. Lymphocytes were also irradiated in vitro, in the presence of Ac-DEVD-CHO, a potent caspase-3 and -7 inhibitor. Results from three experiments performed at the Grand Accelerateur National d'Ions Lourds (GANIL, Caen, France) are reported here. They indicate that carbon ions induce a marked, dose-dependent, reduction of the spleen weight and cellularity. However, in sharp contrast with spleen cells prepared from X-ray irradiated mice, only a slight increase of apoptosis is evidenced in cultured lymphocytes from mice irradiated with heavy ions. The significance of such results is discussed. So far, few data exist concerning the biological effects of heavy ions, in particular their capacity to induce apoptosis in lymphocytes; the present study provides useful clues for further investigations. (author)

  14. Biological intercomparison using gut crypt survivals for proton and carbon-ion beams

    International Nuclear Information System (INIS)

    Charged particle therapy depends on biological information for the dose prescription. Relative biological effectiveness or RBE for this requirement could basically be provided by experimental data. As RBE values of protons and carbon ions depend on several factors such as cell/tissue type, biological endpoint, dose and fractionation schedule, a single RBE value could not deal with all different radiosensitivities. However, any biological model with accurate reproducibility is useful for comparing biological effectiveness between different facilities. We used mouse gut crypt survivals as endpoint, and compared the cell killing efficiency of proton beams at three Japanese facilities. Three Linac X-ray machines with 4 and 6 MeV were used as reference beams, and there was only a small variation (coefficient of variance<2%) in biological effectiveness among them. The RBE values of protons relative to Linac X-rays ranged from 1.0 to 1.11 at the middle of a 6-cm SOBP (spread-out Bragg peak) and from 0.96 to 1.01 at the entrance plateau. The coefficient of variance for protons ranged between 4.0 and 5.1%. The biological comparison of carbon ions showed fairly good agreement in that the difference in biological effectiveness between National Institute of Radiological Sciences (NIRS)/ Heavy Ion Medical Accelerator in Chiba (HIMAC) and Gesellschaft fur Schwerionenforschung (GSI)/Heavy Ion Synchrotron (SIS) was 1% for three positions within the 6-cm SOBP. The coefficient of variance was <1.7, <0.6 and <1.6% for proximal, middle and distal SOBP, respectively. We conclude that the inter-institutional variation of biological effectiveness is smaller for carbon ions than protons, and that beam-spreading methods of carbon ions do not critically influence gut crypt survival. (author)

  15. 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.

  16. Hardness and stress of amorphous carbon film deposited by glow discharge and ion beam assisting deposition

    CERN Document Server

    Marques, F C

    2000-01-01

    The hardness and stress of amorphous carbon films prepared by glow discharge and by ion beam assisting deposition are investigated. Relatively hard and almost stress free amorphous carbon films were deposited by the glow discharge technique. On the other hand, by using the ion beam assisting deposition, hard films were also obtained with a stress of the same order of those found in tetrahedral amorphous carbon films. A structural analysis indicates that all films are composed of a sp sup 2 -rich network. These results contradict the currently accepted concept that both stress and hardness are only related to the concentration of sp sup 3 sites. Furthermore, the same results also indicate that the sp sup 2 sites may also contribute to the hardness of the films.

  17. Hierarchical mesoporous/microporous carbon with graphitized frameworks for high-performance lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Yingying; Fang, Yin; Qian, Xufang; Tu, Bo [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Laboratory of Advanced Materials, Fudan University, Shanghai 200433 (China); Wu, Zhangxiong [Department of Chemical Engineering, Monash University, Clayton, VIC 3800 (Australia); Asiri, Abdullah M. [Chemistry Department and The Center of Excellence for Advanced Materials Research, King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia); Zhao, Dongyuan, E-mail: dyzhao@fudan.edu.cn [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Laboratory of Advanced Materials, Fudan University, Shanghai 200433 (China); Department of Chemical Engineering, Monash University, Clayton, VIC 3800 (Australia)

    2014-11-01

    A hierarchical meso-/micro-porous graphitized carbon with uniform mesopores and ordered micropores, graphitized frameworks, and extra-high surface area of ∼2200 m{sup 2}/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{sup +} 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.

  18. Double-ion imprinted polymer @magnetic nanoparticles modified screen printed carbon electrode for simultaneous analysis of cerium and gadolinium ions

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Bhim Bali, E-mail: prof.bbpd@yahoo.com; Jauhari, Darshika

    2015-05-22

    Highlights: • Synthesis of a double-ion imprinted polymer for analysis of Ce(IV) and Gd(III). • Imprinted nano-beads were grown on MNPs-modified SPCE surface. • Voltammetric determination of both templates was carried out simultaneously. • Ultra-trace analysis with LOD (ng mL{sup −1}) 0.07 for Ce(IV) and 0.19 for Gd(III) is achieved. - Abstract: A typical, reproducible, and rugged screen printed carbon electrode, modified with dual-ion imprinted beads, was fabricated employing the “surface grafting from” approach. For this, the acyl chloride functionalized magnetic nanoparticles were first immobilized and chemically attached with a typical functional monomer (but-2-enedioic acid bis-[(2-amino-ethyl)-amide]) on the electrode surface. This was subsequently subjected to the thermal polymerization in the presence of template ions (Ce(IV) and Gd(III)), cross-linker (ethylene glycol dimethacrylate), initiator (AIBN), and multiwalled carbon nanotubes. The modified sensor was used for the simultaneous analysis of both template ions in aqueous, blood serum, and waste-water samples, using differential pulse anodic stripping voltammetry which revealed two oxidation peaks for respective templates with resolution as much as 950 mV, without any cross reactivity, interferences and false-positives. The detection limits realized by the proposed sensor, under optimized conditions, were found to be as low as 0.07 ng mL{sup −1} for Ce(IV) and 0.19 ng mL{sup −1} for Gd(III) (S/N = 3) that could eventually be helpful for lanthanide estimation at stringent levels.

  19. 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.

  20. Enhanced mercury ion adsorption by amine-modified activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Jianzhong [Center of Environmental Sciences, Lincoln University of Missouri, Jefferson City, MO 65102 (United States); Yang, John, E-mail: yangj@lincolnu.edu [Center of Environmental Sciences, Lincoln University of Missouri, Jefferson City, MO 65102 (United States); Deng Baolin [Department of Civil and Environmental Engineering, University of Missouri, Columbia, MO 65211 (United States)

    2009-07-30

    Mercury (Hg) is one of the most toxic metals found in water and sediments. In an effort to develop an effective adsorbent for aqueous Hg removal, activated carbon (AC) was modified with an amino-terminated organosilicon (3-aminopropyltriethoxysilane, APTES). Surface properties of the APTES-modified AC (MAC) were characterized by the scanning electron microscopy in conjunction with the energy-dispersive spectroscopy (SEM-EDS), the Fourier transform infrared spectroscopy (FT-IR), and potentiometry. The impacts of solvent, APTES concentration, reactive time and temperature on the surface modification were evaluated. The aqueous Hg adsorptive kinetics and capacity were also determined. Results demonstrated that the strong Hg-binding amine ligands were effectively introduced onto the AC surfaces through the silanol reaction between carbon surface functional groups (-COOH, -COH) and APTES molecules. The modification lowered the pH at the point of zero charge (pH{sub pzc}) to 4.54 from 9.6, favoring cation adsorption. MAC presented a faster rate of the Hg (II) adsorption and more than double adsorptive capacity as compared with AC.

  1. Extraction of copper ions by supercritical carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Complexation combined with supercritical fluid extraction was used to extract Cu2+ in this study. The effects of pressure, temperature, volume of CO2 on the efficiency of extraction were systematically investigated. At the optimum condition a 57.32% recovery was achieved. Addition of suitable amount of methanol(v/v = 5 % ) to the supercritical CO2 can increase in the extraction of Cu2+ (72.69 %, RSD = 2.12 %, n = 3). And the recovery can further increase in the presence of non-ionic surfactant Triton X-100 because of its function of solubilization. Surfactant was first used in the extraction of metal ions in the present study, and the results are satisfied (90.52%, RSD=2.20%, n =3).

  2. 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...

  3. Cyclam Modified Carbon Paste Electrode as a Potentiometric Sensor For Determination of Cobalt(Ⅱ) Ions

    Institute of Scientific and Technical Information of China (English)

    Hamid Reza POURETEDAL; Mohammad Hossein KESHAVARZ

    2005-01-01

    A new modified carbon paste electrode based on cyclam as a modifier was prepared for the determination of Co(Ⅱ) ions. The proposed electrode shows a Nernstian slope 28.4 mV per decade over a wide concentration range 5.0×10-6_1.0×10-1 mol/L of Co2+ ions with detection limit 2.5×10-6 mol/L. The sensor exhibits good selectivities for Co2+ over a wide variety of other cations. It can be used as an indicator electrode in potentiometric titration of cobalt(Ⅱ) ions as well as in direct determination of cobalt(Ⅱ) ions in wastewater of acidic cobalt electroplating bath. The electrode shows Nernestian behavior in a solution of 25% ethanol.

  4. Nano-sized Fe3O4/carbon as anode material for lithium ion battery

    International Nuclear Information System (INIS)

    Nano-sized Fe3O4/carbon material is prepared via a simple citric-nitrate combustion method combining with a hydrothermal carbon coating technique. The synthesized Fe3O4/carbon composite shows a high reversible specific capacity (ca. 850 mAh g−1 at 100 mA g−1; ca. 600 mAh g−1 at 500 mA g−1), good rate-capability as well as superior cycling stability as anode for lithium-ion batteries. The ameliorated electrochemical performance of Fe3O4/carbon electrode is associated to the nano-sized particle feature and the continuous carbon coating layer. The former provides short lithium-ion/electron diffusion distance, while the latter enables the fast electron transport pathways. Besides, the carbon layer can act as a protective component to prevent the active particle Fe3O4 from aggregation and pulverization during the charge/discharge processes. - Highlights: • Nano-sized Fe3O4/C was prepared by a simple citric-nitrate combustion process. • Fe3O4/C particles show core–shell structure. • Fe3O4/C powder displays high specific capacity and good cycling stability. • Fe3O4/C composite exhibits a superior rate-capability

  5. Ion irradiation of electronic-type-separated single wall carbon nanotubes: A model for radiation effects in nanostructured carbon

    International Nuclear Information System (INIS)

    The structural and electrical properties of electronic-type-separated (metallic and semiconducting) single wall carbon nanotube (SWCNT) thin-films have been investigated after irradiation with 150 keV 11B+ and 150 keV 31P+ with fluences ranging from 1012 to 1015 ions/cm2. Raman spectroscopy results indicate that the ratio of the Raman D to G′ band peak intensities (D/G′) is a more sensitive indicator of SWCNT structural modification induced by ion irradiation by one order of magnitude compared to the ratio of the Raman D to G band peak intensities (D/G). The increase in sheet resistance (Rs) of the thin-films follows a similar trend as the D/G′ ratio, suggesting that the radiation induced variation in bulk electrical transport for both electronic-types is equal and related to localized defect generation. The characterization results for the various samples are compared based on the displacement damage dose (DDD) imparted to the sample, which is material and damage source independent. Therefore, it is possible to extend the analysis to include data from irradiation of transferred CVD-graphene films on SiO2/Si substrates using 35 keV C+ ions, and compare the observed changes at equivalent levels of ion irradiation-induced damage to that observed in the SWCNT thin-film samples. Ultimately, a model is developed for the prediction of the radiation response of nanostructured carbon materials based on the DDD for any incident ion with low-energy recoil spectra. The model is also related to the defect concentration, and subsequently the effective defect-to-defect length, and yields a maximum defect concentration (minimum defect-to-defect length) above which the bulk electrical transport properties in SWCNT thin-films and large graphene-based electronic devices rapidly degrade when exposed to harsh environments.

  6. Study of Exotic Ions in Superfluid Helium-4 Using a Carbon Nanotube Source

    International Nuclear Information System (INIS)

    We have extended our measurements of the properties of exotic negatively-charged ions in superfluid helium-4. We measured the ion mobility using the time-of-of-flight method at temperatures in the range between 1.03 and 1.16 K. Ions were generated by an electrical discharge produced by applying a voltage to sharp tips in the helium vapor above the liquid surface. Previous studies by Ihas and Sanders, Eden and McClintock, and by our group used tungsten tips and were able to detect at least twelve exotic ions in addition to the normal electron bubble. In the present work we have experimented with tips each consisting of a stainless steel wire coated with carbon nanotubes. We have found that with these tips the strength of the exotic ion signal is substantially increased making it possible to detect several ions which previously could not be seen. The present data combined with the results of the previous studies indicate that there are at least eighteen exotic ions with different mobility

  7. Carbon Ion Radiotherapy in Advanced Hypofractionated Regimens for Prostate Cancer: From 20 to 16 Fractions

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Tohru [National Institute of Radiological Sciences, Chiba (Japan); Tsuji, Hiroshi, E-mail: h_tsuji@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Kamada, Tadashi [National Institute of Radiological Sciences, Chiba (Japan); Akakura, Koichiro; Suzuki, Hiroyoshi; Shimazaki, Jun [Department of Urology, Graduate School of Medicine, Chiba University, Chiba (Japan); Tsujii, Hirohiko [National Institute of Radiological Sciences, Chiba (Japan)

    2012-11-15

    Purpose: To assess the effects of differences in dose fractionation on late radiation toxicity and biochemical control in patients with prostate cancer treated with carbon ion radiotherapy (C-ion RT). Methods and Materials: A total of 740 prostate cancer patients who received C-ion RT between April 2000 and February 2009 were analyzed. Of those, 664 patients followed for at least 1 year were analyzed with regard to late radiation toxicity. Biochemical relapse-free (BRF) and overall survival (OS) rates in patient subgroups with each dose-fractionation were analyzed. Results: Only 1 case of grade 3 genitourinary (GU) morbidity was observed in 20 fractions, and none of the patients developed higher grade morbidities. The incidence of late GU toxicity in patients treated with 16 fractions was lower than that of patients treated with 20 fractions. The OS rate and BRF rate of the entire group at 5 years were 95.2% and 89.7%, respectively. The 5-year BRF rate of the patients treated with 16 fractions of C-ion RT (88.5%) was comparable to that of the patients treated with 20 fractions (90.2%). Conclusion: C-ion RT of 57.6 GyE (the physical C-ion dose [Gy] Multiplication-Sign RBE) in 16 fractions could offer an even lower incidence of genitourinary toxicity and comparable BRF rate than that in 20 fractions. Advancement in hypofractionation could be safely achieved with C-ion RT for prostate cancer.

  8. Lithium iron phosphate/carbon nanocomposite film cathodes for high energy lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yanyi; Liu Dawei; Zhang Qifeng [Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195 (United States); Yu Danmei [Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195 (United States); College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Liu Jun [Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA 99352 (United States); Cao Guozhong, E-mail: gzcao@u.washington.ed [Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195 (United States)

    2011-02-01

    This paper reports sol-gel derived nanostructured LiFePO{sub 4}/carbon nanocomposite film cathodes exhibiting enhanced electrochemical properties and cyclic stabilities. LiFePO{sub 4}/carbon films were obtained by spreading sol on Pt coated Si wafer followed by ambient drying overnight and annealing/pyrolysis at elevated temperature in nitrogen. Uniform and crack-free LiFePO{sub 4}/carbon nanocomposite films were readily obtained and showed olivine phase as determined by means of X-Ray Diffractometry. The electrochemical characterization revealed that, at a current density of 200 mA/g (1.2 C), the nanocomposite film cathodes demonstrated an initial lithium-ion intercalation capacity of 312 mAh/g, and 218 mAh/g after 20 cycles, exceeding the theoretical storage capacity of conventional LiFePO{sub 4} electrode. Such enhanced Li-ion intercalation performance could be attributed to the nanocomposite structure with fine crystallite size below 20 nm as well as the poor crystallinity which provides a partially open structure allowing easy mass transport and volume change associated with Li-ion intercalation. Moreover the surface defect introduced by carbon nanocoating could also effectively facilitate the charge transfer and phase transitions.

  9. Lithium iron phosphate/carbon nanocomposite film cathodes for high energy lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanyi; Liu, Dawei; Zhang, Qifeng; Yu, Danmei; Liu, Jun; Cao, Guozhong

    2011-02-01

    This paper reports sol-gel derived nanostructured LiFePO4/carbon nanocomposite film cathodes exhibiting enhanced electrochemical properties and cyclic stabilities. LiFePO4/carbon films were obtained by spreading sol on Pt coated Si wafer followed by ambient drying overnight and annealing/pyrolysis at elevated temperature in nitrogen. Uniform and crack-free LiFePO4/carbon nanocomposite films were readily obtained and showed olivine phase as determined by means of X-Ray Diffractometry. The electrochemical characterization revealed that, at a current density of 200 mA/g (1.2 C), the nanocomposite film cathodes demonstrated an initial lithium-ion intercalation capacity of 312 mAh/g, and 218 mAh/g after 20 cycles, exceeding the theoretical storage capacity of conventional LiFePO4 electrode. Such enhanced Li-ion intercalation performance could be attributed to the nanocomposite structure with fine crystallite size below 20 nm as well as the poor crystallinity which provides a partially open structure allowing easy mass transport and volume change associated with Li-ion intercalation. Moreover the surface defect introduced by carbon nanocoating could also effectively facilitate the charge transfer and phase transitions.

  10. Lithium iron phosphate/carbon nanocomposite film cathodes for high energy lithium ion batteries

    International Nuclear Information System (INIS)

    This paper reports sol-gel derived nanostructured LiFePO4/carbon nanocomposite film cathodes exhibiting enhanced electrochemical properties and cyclic stabilities. LiFePO4/carbon films were obtained by spreading sol on Pt coated Si wafer followed by ambient drying overnight and annealing/pyrolysis at elevated temperature in nitrogen. Uniform and crack-free LiFePO4/carbon nanocomposite films were readily obtained and showed olivine phase as determined by means of X-Ray Diffractometry. The electrochemical characterization revealed that, at a current density of 200 mA/g (1.2 C), the nanocomposite film cathodes demonstrated an initial lithium-ion intercalation capacity of 312 mAh/g, and 218 mAh/g after 20 cycles, exceeding the theoretical storage capacity of conventional LiFePO4 electrode. Such enhanced Li-ion intercalation performance could be attributed to the nanocomposite structure with fine crystallite size below 20 nm as well as the poor crystallinity which provides a partially open structure allowing easy mass transport and volume change associated with Li-ion intercalation. Moreover the surface defect introduced by carbon nanocoating could also effectively facilitate the charge transfer and phase transitions.

  11. Response of a silicon telescope microdosimeter to 400 AMeV carbon ions

    International Nuclear Information System (INIS)

    A monolithic silicon telescope consisting of a surface ΔE detector 2 μm in thickness coupled to an E detector about 500 μm in thickness made out of a single silicon wafer was recently proposed for the microdosimetric characterization of hadron beams. This device and its pixelated version are intended to be irradiated at the Centro Nazionale di Adroterapia Oncologica (CNAO, National Centre for Oncological Hadrontherapy, Pavia, Italy) with a 400 AMeV carbon ion beam. The response of the silicon microdosimeter under these conditions was calculated with Monte Carlo simulations by using the FLUKA code, in order to have reference available for comparison with the experimental results. - Highlights: • FLUKA simulations performed to study the response of silicon telescope to carbon ions. • Energy distribution of ions from carbon fragmentation were calculated. • Microdosimetric spectra corrected for tissue-equivalence were derived. • Feasibility of the ΔE stage telescope in a 400 AMeV carbon beam was demonstrated

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ting [University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026 (China); Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li Fanghua [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Liu Qingfang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Bian Po, E-mail: bianpo@ipp.ac.cn [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Wang Jufang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Wu Yuejin; Wu Lijun [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agricultural Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li Wenjian [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China)

    2012-09-01

    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 {gamma}-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.

  13. A digital approach to neutron dosimetry and microdosimetry

    International Nuclear Information System (INIS)

    Work has begun in an effort to develop a new, digital approach to neutron dosimetry. In contrast to analogue methods in current use, digital information describes the track of a recoil charged particle produced by a neutron in a gas in terms of the numbers of ions that occur in given volume elements of a detector. It appears that a device based on the time-projection chamber used in particle physics would enable one to measure relevant data for neutron dosimetry. Such an instrument would also furnish data sought in microdosimetry. In this paper we will describe the digital approach to dosimetry and will report on the initial Monte Carlo calculations of the detailed transport of protons and electrons in Ar, CH4, and P-10 gases. These calculations are being used to assess the feasibility of constructing a practical chamber for use in neutron dosimetry and in microdosimetry

  14. Optimizing pyrolysis of resin carbon for anode of lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin.Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structures and characteristics of the carbon materials were determined by X-ray diffraction, Brunauer-Emmer-Teller surface area analysis and electrochemical measurements. With the increase of pyrolyzing temperature and soaking time,the resin carbon material has larger crystallite sizes of Lc and La, lower specific surface area, smaller irreversible capacity and higher initial coulombic efficiency. The pyrolyzing temperature and soaking time are optimized to be 1050℃ and 2 h. The resin carbon anode obtained under the optimum conditions shows good electrochemical performances with reversible capacity of 387 mA · h/g and initial coulombic efficiency of 69.1%.

  15. Ion exchange reactions in interaction of basic zirconium sulfate with sodium carbonate solution

    International Nuclear Information System (INIS)

    Basic zirconium sulfates, extracted from basic zirconium chloride solution and zirconium disulfate solution, as well as products of their interaction with sodium carbonate solution, which was exposed and not exposed to hydrolysis, were investigated by chemical and NMR spectroscopy methods. It has been established that the process of interaction of the basic zirconium sulfate with sodium carbonate solutions sulfatocarbonatozicrconates and carbonatozirconates of sodium are sequentially formed. In this case carbonate groups, due to different strenght of addition of hydroxogroups in initial basic sulfates, substitute either SOsub(h)sup(2)-)- groups and H2O or SO42--and OH--groups, and sodium ions substitute H3O+-groups. Carbonate groups, if they have substituted sulfato- or hydroxogroup, during hydrolysis of carbonatozirconates are splitted out to a less degree

  16. Transport of carbon ion test particles and hydrogen recycling in the plasma of the Columbia tokamak ''HBT'' [High Beta Tokamak

    International Nuclear Information System (INIS)

    Carbon impurity ion transport is studied in the Columbia High Beta Tokamak (HBT), using a carbon tipped probe which is inserted into the plasma (ne ∼ 1 - 5 x 1014 (cm-3), Te ∼ 4 - 10 (eV), Bt ∼ 0.2 - 0.4(T)). Carbon impurity light, mainly the strong lines of CII(4267A, emitted by the C+ ions) and CIII (4647A, emitted by the C++ ions), is formed by the ablation or sputtering of plasma ions and by the discharge of the carbon probe itself. The diffusion transport of the carbon ions is modeled by measuring the space-and-time dependent spectral light emission of the carbon ions with a collimated optical beam and photomultiplier. The point of emission can be observed in such a way as to sample regions along and transverse to the toroidal magnetic field. The carbon ion diffusion coefficients are obtained by fitting the data to a diffusion transport model. It is found that the diffusion of the carbon ions is ''classical'' and is controlled by the high collisionality of the HBT plasma; the diffusion is a two-dimensional problem and the expected dependence on the charge of the impurity ion is observed. The measurement of the spatial distribution of the Hα emissivity was obtained by inverting the light signals from a 4-channel polychromator, the data were used to calculate the minor-radial influx, the density, and the recycling time of neutral hydrogen atoms or molecules. The calculation shows that the particle recycling time τp is comparable with the plasma energy confinement time τE; therefore, the recycling of the hot plasma ions with the cold neutrals from the walls is one of the main mechanisms for loss of plasma energy

  17. Effective Stress Reduction in Diamond Films on Alumina by Carbon Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    方志军; 夏义本; 王林军; 张伟丽; 马哲国; 张明龙

    2002-01-01

    We show the effective stress reduction in diamond films by implanting carbon ions into alumina substrates prior to the diamond deposition. Residual stresses in the films are evaluated by Raman spectroscopy and a more reliable method for stress determination is presented for the quantitative measurement of stress evolution. It is found that compressive stresses in the diamond films can be partly offset by the compressive stresses in the alumina substrates, which are caused by the ion pre-implantation. At the same time, the difference between the offset by the pre-stressed substrates and the total stress reduction indicates that some other mechanisms are also active.

  18. The influence of ion bombardment on emission properties of carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Chepusov, Alexander, E-mail: chepusov@iep.uran.ru [The Institute of Electrophysics of the Ural Division of the Russian Academy of Sciences (IEP UD RAS), 620016, 106 Amundsen Street, Ekaterinburg (Russian Federation); Ural Federal University, 620002, 19 Mira Street, Ekaterinburg (Russian Federation); Komarskiy, Alexander, E-mail: aakomarskiy@gmail.com [The Institute of Electrophysics of the Ural Division of the Russian Academy of Sciences (IEP UD RAS), 620016, 106 Amundsen Street, Ekaterinburg (Russian Federation); Ural Federal University, 620002, 19 Mira Street, Ekaterinburg (Russian Federation); Kuznetsov, Vadim, E-mail: kuznetsov@iep.uran.ru [The Institute of Electrophysics of the Ural Division of the Russian Academy of Sciences (IEP UD RAS), 620016, 106 Amundsen Street, Ekaterinburg (Russian Federation)

    2014-07-01

    When electric-vacuum device works its cathode surface experiences bombardment with ions of residual gases. Effects of ion bombardment impact on surface of field emission cathodes made of carbon materials may essentially change emission properties of such cathodes. It changes emission start electric field strength, voltage vs. current characteristic of material, its relief and electron structure of the surface layer. Field emission cathode operating mode, variation of radiation doses allow to obtain both good effects: maximal electric current, surface recovery – and negative ones: the worst emission properties and surface destruction, amorphization.

  19. Nutrient and carbonate ion proxy calibrations in the deep sea coral D. dianthus (Invited)

    Science.gov (United States)

    Anagnostou, E.; Lavigne, M.; Gagnon, A. C.; Adkins, J. F.; McDonough, W. F.; Sherrell, R. M.

    2009-12-01

    Marine carbonates are among the most successful and reliable substrates for chemical paleoceanographic studies. Deep-sea corals are especially useful because they allow measurement of both 14C and U-Th dates in a single coral. Tracers, however, are needed to derive ventilation rates in the past from the mixing ratio of distinct endmember water masses. Reconstruction of nutrient abundances and carbonate ion distributions, even in regions where deep mixing is sluggish and regeneration is significant, could provide clues about basin-scale variations in export production, changes in whole-ocean nutrient inventory, and carbonate system equilibria on geological timescales. To fill this gap, we present modern calibrations of two paleo-nutrient proxies and a carbonate ion proxy in the deep sea coral D. dianthus. We demonstrate that P/Ca, Ba/Ca and U/Ca are direct proxies for phosphate (remineralized at shallow depths), dissolved barium (a deep-remineralized element with silicate-type distribution) and seawater carbonate ion, respectively. We analyzed 20, globally distributed, D. dianthus specimens using a 193nm excimer laser ablation HR-ICP-MS, along growth axis-oriented septal thick sections, which reveals the internal structure. Using an 80-100 μm spot size, data are collected from within the fibrous aragonite avoiding central band material as well as contamination and altered aragonite on the exterior of the septa. All seawater data used are derived from nearby WOCE/GEOSECS/CLIVAR stations. Plotting the coralline P/Ca against ambient seawater phosphate resulted in a calibration with an apparent partition coefficient (D= Element/Cacoral / Element/Caseawater) of 0.5 ± 0.1 (r=0.8, P<0.05, n=17). Similarly, the Ba/Ca in the coral versus dissolved seawater barium gave a DBa= 1.3 ± 0.3 (r= 0.8, P<0.05, n=15), and coralline U/Ca (µmol/mol) versus seawater carbonate ion (µmol/kg) gave a regression slope of -0.098 ± 0.002 (r=0.8, P<0.05, n=13). We tested potential

  20. In Situ Carbonized Cellulose-Based Hybrid Film as Flexible Paper Anode for Lithium-Ion Batteries.

    Science.gov (United States)

    Cao, Shaomei; Feng, Xin; Song, Yuanyuan; Liu, Hongjiang; Miao, Miao; Fang, Jianhui; Shi, Liyi

    2016-01-20

    Flexible free-standing carbonized cellulose-based hybrid film is integrately designed and served both as paper anode and as lightweight current collector for lithium-ion batteries. The well-supported heterogeneous nanoarchitecture is constructed from Li4Ti5O12 (LTO), carbonized cellulose nanofiber (C-CNF) and carbon nanotubes (CNTs) using by a pressured extrusion papermaking method followed by in situ carbonization under argon atmospheres. The in situ carbonization of CNF/CNT hybrid film immobilized with uniform-dispersed LTO results in a dramatic improvement in the electrical conductivity and specific surface area, so that the carbonized paper anode exhibits extraordinary rate and cycling performance compared to the paper anode without carbonization. The flexible, lightweight, single-layer cellulose-based hybrid films after carbonization can be utilized as promising electrode materials for high-performance, low-cost, and environmentally friendly lithium-ion batteries. PMID:26727586

  1. Chemically and biologically modified activated carbon sorbents for the removal of lead ions from aqueous media.

    Science.gov (United States)

    Mahmoud, Mohamed E; Abdel-Fattah, Tarek M; Osman, Maher M; Ahmed, Somia B

    2012-01-01

    A method is described for hybridization of the adsorption and biosorption characteristics of chemically treated commercial activated carbon and baker's yeast, respectively, for the formation of environmental friendly multifunctional sorbents. Activated carbon was loaded with baker's yeast after acid-base treatment. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) Spectroscopy were used to characterize these sorbents. Moreover, the sorption capabilities for lead (II) ions were evaluated. A value of 90 μmol g(-1) was identified as the maximum sorption capacity of activated carbon. Acid-base treatment of activated carbon was found to double the sorption capacity (140-180 μmol g(-1)). Immobilization of baker's yeast on the surface of activated carbon sorbents was found to further improve the sorption capacity efficiency of lead to 360, 510 and 560 μmol g(-1), respectively. Several important factors such as pH, contact time, sorbent dose, lead concentration and interfering ions were examined. Lead sorption process was studied and evaluated by several adsorption isotherms and found to follow the Langmuir and BET models. The potential applications of various chemically and biologically modified sorbents and biosorbents for removal of lead from real water matrices were also investigated via multistage micro-column technique and the results referred to excellent recovery values of lead (95.0-99.0 ± 3.0-5.0 %).

  2. Geant4 Simulation Study of Dose Distribution and Energy Straggling for Proton and Carbon Ion Beams in Water

    OpenAIRE

    Zhao Qiang; Zhang Zheng; Li Yang

    2016-01-01

    Dose distribution and energy straggling for proton and carbon ion beams in water are investigated by using a hadrontherapy model based on the Geant4 toolkit. By gridding water phantom in N×N×N voxels along X, Y and Z axes, irradiation dose distribution in all the voxels is calculated. Results indicate that carbon ion beams have more advantages than proton beams. Proton beams have bigger width of the Bragg peak and broader lateral dose distribution than carbon ion beams for the same position o...

  3. 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.

  4. Field-ion microscopy observation of single-walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    张兆祥; 张耿民; 杜民; 金新喜; 侯士敏; 孙建平; 顾镇南; 赵兴钰; 刘惟敏; 吴锦雷; 薛增泉

    2002-01-01

    Field-ion microscopy (FIM), a tool for surface analysis with atomic resolution, has been employed to observethe end structure of single-walled carbon nanotubes (SWCNTs). FIM images revealed the existence of open SWCNTends. Amorphous carbon atoms were also observed to occur around SWCNTs and traditional field evaporation failedto remove them. Heat treatment was found to be efficacious in altering the end structures of SWCNT bundles. Carbonand oxygen atoms released from heated tungsten filament are believed to be responsible for the decoration imposed onthe SWCNT ends.

  5. 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 monoxide were up to 50% larger than those calculated from gas-stopping data. The latter result...

  6. Probing the complex ion structure in liquid carbon at 100 GPa.

    Science.gov (United States)

    Kraus, D; Vorberger, J; Gericke, D O; Bagnoud, V; Blažević, A; Cayzac, W; Frank, A; Gregori, G; Ortner, A; Otten, A; Roth, F; Schaumann, G; Schumacher, D; Siegenthaler, K; Wagner, F; Wünsch, K; Roth, M

    2013-12-20

    We present the first direct experimental test of the complex ion structure in liquid carbon at pressures around 100 GPa, using spectrally resolved x-ray scattering from shock-compressed graphite samples. Our results confirm the structure predicted by ab initio quantum simulations and demonstrate the importance of chemical bonds at extreme conditions similar to those found in the interiors of giant planets. The evidence presented here thus provides a firmer ground for modeling the evolution and current structure of carbon-bearing icy giants like Neptune, Uranus, and a number of extrasolar planets. PMID:24483747

  7. Study on the thermoluminescent properties of K2YF5 and K2GdF5 crystals doped with optically active trivalent ions for gamma and neutrons dosimetry

    International Nuclear Information System (INIS)

    In this work, the thermoluminescent (TL) properties of both double potassium yttrium fluoride (K2YF5) and double potassium gadolinium fluoride (K2GdF5) crystals doped with optically active rare earth ions were investigated from the point of view of gamma and neutron dosimetry. Crystalline platelets with thickness of about 1 mm, synthesized under hydrothermal conditions, were irradiated in order to study TL sensitivity, as well as dose and energy response, reproducibility and fading, in terms of Ce3+, Tb3+, Dy3+, e Pr3+ concentrations. The K2YF5 crystals doped with 1.0 at por cent Dy3+ have been found to have an excellent linear TL response to X and gamma photons, in the range of 0.01 to 10 mGy. The TL output is comparable to that of CaS04:Mn dosemeters. The main peak at 130 deg C has been found to have a TL response for 41.1 keV X-ray energy 32 times higher than that for 662 keV gamma rays. This fact points out that the K2Y0.99Dy0.01F5 crystals have great potential for X-rays diagnostic and/or industrial radiography. On the other hand, the K2GdF5 crystals doped with 5.0 at por cent Dy3+ have been found to have the better TL response for gamma and fast neutron radiation, among the dopants studied. For gamma fields the TL response was linear for doses ranging from 0.1 to 200 mGy. The TL peak around 200 deg C can be deconvoluted into four individual peaks, all of them with linear behavior. For fast neutron radiation produced by an 241AmBe source, the TL responses for doses ranging from 0.6 to 12 mSv were also linear and comparable to that of commercial TLD-600, irradiated at same conditions. The TL emission due to neutrons was in the high temperature range, above 200 deg C. These results points out that K2Gd0.95Dy0.05F5 crystals are good candidates for use in neutron dosimetry applications. (author)

  8. 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.

  9. Synergistic strengthening of polyelectrolyte complex membranes by functionalized carbon nanotubes and metal ions.

    Science.gov (United States)

    Liu, Tao; An, Quan-Fu; Zhao, Qiang; Wu, Jia-Kai; Song, Yi-Hu; Zhu, Bao-Ku; Gao, Cong-Jie

    2015-01-01

    Hydrophilic polymers have garnered much attention due to their critical roles in various applications such as molecular separation membranes, bio-interfaces, and surface engineering. However, a long-standing problem is that their mechanical properties usually deteriorate at high relative humidity (RH). Through the simultaneous incorporation of functionalized carbon nanotubes and copper ions (Cu(2+)), this study introduces a facile method to fabricate high strength polyelectrolyte complex nanohybrid membranes resistant to high RH (90%). For example, the tensile strength of the nanohybrid membranes is 55 MPa at 90% RH (80% of the original value at 30% RH). These results are explained by copper ions depressing the swelling degree of the membrane, and functionalized carbon nanotubes promoting stress transfer between the polymer matrix and them. The nanohybrid membranes are efficient in separating water/alcohol mixtures containing relatively high water content (up to 30 wt%), whereas common hydrophilic polymer membranes usually suffer from excessive swelling under this condition. PMID:25586650

  10. Relationship between initial efficiency and structure parameters of carbon anode material for Li-ion battery

    Institute of Scientific and Technical Information of China (English)

    SHEN Jian-bin; TANG You-gen; LIANG Yi-zeng; TAN Xin-xin

    2008-01-01

    The initial efficiency is a very important criterion for carbon anode material of Li-ion battery. The relationship between initial efficiency and structure parameters of carbon anode material of Li-ion battery was investigated by an artificial intelligence approach called Random Forests using D10, D50, D90, BET specific surface area and TP density as inputs, initial efficiency as output.The results give good classification performance with 91% accuracy. The variable importance analysis results show the impact of 5 variables on the initial efficiency descends in the order of D90, TP density, BET specific surface area, D50 and D10; smaller D90 and larger TP density have positive impact on initial efficiency. The contribution of BET specific surface area on classification is only 18.74%, which indicates the shortcoming of BET specific surface area as a widely used parameter for initial efficiency evaluation.

  11. Carbon-coated silicon nanotube arrays on carbon cloth as a hybrid anode for lithium-ion batteries

    Science.gov (United States)

    Wang, Wei; Gu, Lin; Qian, Haolei; Zhao, Ming; Ding, Xi; Peng, Xinsheng; Sha, Jian; Wang, Yewu

    2016-03-01

    Silicon hollow nanostructure has been considered as one of the most promising material for commercial application in lithium-ion batteries due to its significant improvement of cycling stability. The fabricated hybrid structures, carbon-coated silicon nanotube arrays on carbon cloth substrate, with a high surface area and short electron collection pathway have been directly used as anode electrodes without any additional binder. The electrodes exhibit high capacity, excellent rate capability and good cycling stability. The discharge capacity of the hybrid electrode (the deposition time of silicon shell: 5 min) keeps stable, and after 100 cycles, the discharge capacities still remain 3654 mAh g-1 at the rate of 0.5 C.

  12. Carbon-Based Materials for Lithium-Ion Batteries, Electrochemical Capacitors, and Their Hybrid Devices.

    Science.gov (United States)

    Yao, Fei; Pham, Duy Tho; Lee, Young Hee

    2015-07-20

    A rapidly developing market for portable electronic devices and hybrid electrical vehicles requires an urgent supply of mature energy-storage systems. As a result, lithium-ion batteries and electrochemical capacitors have lately attracted broad attention. Nevertheless, it is well known that both devices have their own drawbacks. With the fast development of nanoscience and nanotechnology, various structures and materials have been proposed to overcome the deficiencies of both devices to improve their electrochemical performance further. In this Review, electrochemical storage mechanisms based on carbon materials for both lithium-ion batteries and electrochemical capacitors are introduced. Non-faradic processes (electric double-layer capacitance) and faradic reactions (pseudocapacitance and intercalation) are generally explained. Electrochemical performance based on different types of electrolytes is briefly reviewed. Furthermore, impedance behavior based on Nyquist plots is discussed. We demonstrate the influence of cell conductivity, electrode/electrolyte interface, and ion diffusion on impedance performance. We illustrate that relaxation time, which is closely related to ion diffusion, can be extracted from Nyquist plots and compared between lithium-ion batteries and electrochemical capacitors. Finally, recent progress in the design of anodes for lithium-ion batteries, electrochemical capacitors, and their hybrid devices based on carbonaceous materials are reviewed. Challenges and future perspectives are further discussed. PMID:26140707

  13. Biological dose representation for carbon-ion radiotherapy of unconventional fractionation

    OpenAIRE

    Kanematsu, Nobuyuki; Inaniwa, Taku

    2016-01-01

    In carbon-ion radiotherapy, single-beam delivery each day in alternate directions has been commonly practiced for operational efficiency, taking advantage of the Bragg peak and the relative biological effectiveness (RBE) for uniform dose conformation to a tumor. The treatment plans are usually evaluated with total RBE-weighted dose, which is however deficient in relevance to the biological effect in the linear-quadratic model due to its quadratic-dose term, or the dose-fractionation effect. I...

  14. Increased effectiveness of carbon ions in the production of reactive oxygen species in normal human fibroblasts

    International Nuclear Information System (INIS)

    The production of reactive oxygen species (ROS), especially superoxide anions (O2·-), is enhanced in many normal and tumor cell types in response to ionizing radiation. The influence of ionizing radiation on the regulation of ROS production is considered as an important factor in the long-term effects of irradiation (such as genomic instability) that might contribute to the development of secondary cancers. In view of the increasing application of carbon ions in radiation therapy, we aimed to study the potential impact of ionizing density on the intracellular production of ROS, comparing photons (X-rays) with carbon ions. For this purpose, we used normal human cells as a model for irradiated tissue surrounding a tumor. By quantifying the oxidization of Dihydroethidium (DHE), a fluorescent probe sensitive to superoxide anions, we assessed the intracellular ROS status after radiation exposure in normal human fibroblasts, which do not show radiation-induced chromosomal instability. After 3–5 days post exposure to X-rays and carbon ions, the level of ROS increased to a maximum that was dose dependent. The maximum ROS level reached after irradiation was specific for the fibroblast type. However, carbon ions induced this maximum level at a lower dose compared with X-rays. Within ∼1 week, ROS decreased to control levels. The time-course of decreasing ROS coincides with an increase in cell number and decreasing p21 protein levels, indicating a release from radiation-induced growth arrest. Interestingly, radiation did not act as a trigger for chronically enhanced levels of ROS months after radiation exposure. (author)

  15. Synthesis of Microspherical LiFePO4-Carbon Composites for Lithium-Ion Batteries

    OpenAIRE

    Maria-Magdalena Titirici; Haihui Wang; Dandan Cai; Linghui Yu

    2013-01-01

    This paper reports an “all in one” procedure to produce mesoporous, micro-spherical LiFePO4 composed of agglomerated crystalline nanoparticles. Each nanoparticle is individually coated with a thin glucose-derived carbon layer. The main advantage of the as-synthesized materials is their good performance at high charge-discharge rates. The nanoparticles and the mesoporosity guarantee a short bulk diffusion distance for both lithium ions and electrons, as well as additional active sites for the ...

  16. Energy loss of swift H3+-molecule ions in carbon foils

    OpenAIRE

    Denton Zanello, Cristian D.; Pérez Pérez, F. Javier; Abril Sánchez, Isabel; García Molina, Rafael; Arista, Néstor R.

    1996-01-01

    The energy loss of H3+-molecule beams interacting with amorphous carbon targets has been calculated, both as a function of the target thickness and the projectile velocity. We have considered the spatial changes, due to Coulomb repulsion, of the initial molecular configuration after the H3+ ion enters the target and then used a dielectric formalism to evaluate the stopping power of the correlated protons. The ratio between the stopping power of the H3+ molecule and that of its constituents co...

  17. In situ formed lithium sulfide/microporous carbon cathodes for lithium-ion batteries.

    Science.gov (United States)

    Zheng, Shiyou; Chen, Yvonne; Xu, Yunhua; Yi, Feng; Zhu, Yujie; Liu, Yihang; Yang, Junhe; Wang, Chunsheng

    2013-12-23

    Highly stable sulfur/microporous carbon (S/MC) composites are prepared by vacuum infusion of sulfur vapor into microporous carbon at 600 °C, and lithium sulfide/microporous carbon (Li2S/MC) cathodes are fabricated via a novel and facile in situ lithiation strategy, i.e., spraying commercial stabilized lithium metal powder (SLMP) onto a prepared S/MC film cathode prior to the routine compressing process in cell assembly. The in situ formed Li2S/MC film cathode shows high Coulombic efficiency and long cycling stability in a conventional commercial Li-ion battery electrolyte (1.0 M LiPF6 + EC/DEC (1:1 v/v)). The reversible capacities of Li2S/MC cathodes remain about 650 mAh/g even after 900 charge/discharge cycles, and the Coulombic efficiency is close to 100% at a current density of 0.1C, which demonstrates the best electrochemical performance of Li2S/MC cathodes reported to date. Furthermore, this Li2S/MC film cathode fabricated via our in situ lithiation strategy can be coupled with a Li-free anode, such as graphite, carbon/tin alloys, or Si nanowires to form a rechargeable Li-ion cell. As the Li2S/MC cathode is paired with a commercial graphite anode, the full cell of Li2S/MC-graphite (Li2S-G) shows a stable capacity of around 600 mAh/g in 150 cycles. The Li2S/MC cathodes prepared by high-temperate sulfur infusion and SLMP prelithiation before cell assembly are ready to fit into current Li-ion batteries manufacturing processes and will pave the way to commercialize low-cost Li2S-G Li-ion batteries. PMID:24251957

  18. Modeling Electrochemical Decomposition of Fluoroethylene Carbonate on Silicon Anode Surfaces in Lithium Ion Batteries

    OpenAIRE

    Leung, Kevin; Rempe, Susan B.; Foster, Michael E.; Ma, Yuguang; del la Hoz, Julibeth M. Martinez; Sai, Na; Balbuena, Perla B.

    2014-01-01

    Fluoroethylene carbonate (FEC) shows promise as an electrolyte additive for improving passivating solid-electrolyte interphase (SEI) films on silicon anodes used in lithium ion batteries (LIB). We apply density functional theory (DFT), ab initio molecular dynamics (AIMD), and quantum chemistry techniques to examine excess-electron-induced FEC molecular decomposition mechanisms that lead to FEC-modified SEI. We consider one- and two-electron reactions using cluster models and explicit interfac...

  19. Copper Nanoparticle-Incorporated Carbon Fibers as Free-Standing Anodes for Lithium-Ion Batteries

    OpenAIRE

    Han, Pan; Yuan, Tao; Yao, Long; Han, Zhuo; Yang, Junhe; Zheng, Shiyou

    2016-01-01

    Copper-incorporated carbon fibers (Cu/CF) as free-standing anodes for lithium-ion batteries are prepared by electrospinning technique following with calcination at 600, 700, and 800 °C. The structural properties of materials are characterized by X-ray diffraction (XRD), Raman, thermogravimetry (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectrometry (EDS). It is found that the Cu/CF composites have smooth, regular, and long fi...

  20. Nuclear medicine radiation dosimetry

    CERN Document Server

    McParland, Brian J

    2010-01-01

    Complexities of the requirements for accurate radiation dosimetry evaluation in both diagnostic and therapeutic nuclear medicine (including PET) have grown over the past decade. This is due primarily to four factors: growing consideration of accurate patient-specific treatment planning for radionuclide therapy as a means of improving the therapeutic benefit, development of more realistic anthropomorphic phantoms and their use in estimating radiation transport and dosimetry in patients, design and use of advanced Monte Carlo algorithms in calculating the above-mentioned radiation transport and

  1. INDIVIDUAL DOSIMETRY SERVICE

    CERN Multimedia

    2000-01-01

    Personnel in the distribution groups Aleph, Delphi, L3, Opal who also work for other experiments than at LEP, should contact their dispatchers to explain their activities for the future, after LEP dismantling in order to be maintained on the regular distribution list at Individual DosimetryWe inform all staff and users under regular dosimetric control that the dosimeters for the monitoring period MAY/JUNE will be available from their usual dispatchers on Tuesday 2 May.Please have your films changed before the 12 May.The colour of the dosimeter valid in is MAY/JUNE is YELLOW.Individual Dosimetry Service will be closed on Friday 28 April.

  2. Electrocatalytic Activity of Carbonized Nanostructured Polyanilines for Oxidation Reactions: Sensing of Nitrite Ions and Ascorbic Acid

    International Nuclear Information System (INIS)

    Highlights: • Carbonized PANIs prepared from various nanostructured PANI precursors • Electroanalytical performances of carbonized PANIs evaluated using voltammetry • Study of carbonized PANIs physico-chemical properties related to electroactivity • The lowest over-potential for NO2− oxidation at c-PANI (+0.87 V vs. SCE) • The lowest over-potential for ascorbic acid oxidation at both c-PANI and c-PANI-SSA - Abstract: A comparative study of the electrocatalytic activity of nitrogen-containing carbon nanomaterials, prepared by the carbonization of nanostructured polyaniline (PANI) salts, for the electrooxidation reactions is presented. Nanostructured PANI salts were synthesized by the oxidative polymerization of aniline with ammonium peroxydisulfate in an aqueous solution in the presence of 5-sulfosalicylic acid (PANI-SSA), 3,5-dinitrosalicylic acid (PANI-DNSA) as well as without added acid (PANI), and subsequently carbonized to c-PANI-SSA, c-PANI-DNSA and c-PANI, respectively. Glassy carbon tip was modified with nanostructured c-PANIs and used for the investigation of sensing of nitrite and ascorbic acid in aqueous solutions as model analytes by linear sweep voltammetry. All three types of the investigated c-PANIs gave excellent response to the nitrite ions and ascorbic acid electrooxidation. The lowest peak potential for nitrite ion oxidation exhibited c-PANI (+0.87 V vs. SCE), and for ascorbic acid oxidation both c-PANI and c-PANI-SSA (ca. + 0.13 V vs. SCE). Electrochemical data were correlated with structural and textural data obtained by Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, elemental and nitrogen sorption analysis

  3. Tl and OSL dosimetry of diamond films CVD pure and unpurified with boron-carbon; Dosimetria Tl y OSL de peliculas de diamante CVD puras e impurificadas con boro-carbono

    Energy Technology Data Exchange (ETDEWEB)

    Melendrez, R.; Pedroza M, M.; Chernov, V.; Ochoa N, J.D.; Bernal, R.; Barboza F, M. [CIF, UNISON, A.P. 5-088, 83190 Hermosillo, Sonora (Mexico); Castaneda, B. [Departamento de Fisica, Universidad de Sonora, Apdo. Postal 1626, Hermosillo, Sonora (Mexico); Goncalves, J.A.N.; Sandonato, G.M. [Laboratorio Associado de Plasma, Instituto Nacional de Pesquisas Espaciais C.P. 515- 12201 -970, Sao Jose dos Campos, SP (Brazil); Cruz Z, E. [Instituto de Ciencias Nucleares, UNAM, Apdo. Postal 70-543, 04510 Mexico D.F. (Mexico); Preciado F, S.; Cruz V, C.; Brown, F. [Departamento de Investigacion en Polimeros y Materiales de la Universidad de Sonora, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Schreck, M. [Universitaet Augsburg, Institut fuer Physik D-86135 Augsburg (Germany)

    2004-07-01

    The diamond is a material that possesses extreme physical properties, such as its hardness to the radiation, its low chemical reactivity besides its equivalence to the human tissue, which qualify him as an ideal material for radiation dosimetry. In this work, it was studied the thermal and optically stimulated response (Tl and OSL) of polycrystalline diamond films grown by the technique of CVD pure and contaminated with Boron-carbon (B/C) with the intention of characterizing their efficiency like a dosemeter for radiation in a range of 0 - 3000 Gy. For the case of the films without impurities, the Tl curve presents four main peaks, two of them in an interval of temperatures of 150-200 C and other two additional around of 250-400 C. The dependence of the response of integrated Tl and that of OSL always maintained a lineal relationship with the exhibition dose up to 100 Gy. The behavior of the films contaminated with B/C (2000 - 20000 ppm) was established through experiments that involved the signal of OSL and their relationship with the Tl response. It was found that this processes are correlated, since the electrons caught in the traps of low temperature (50 - 250 C) of the Tl they are the electrons that recombining with more probability to provide the signal of OSL. According to these results it is possible to propose the diamond films as a good candidate for dosimetry to, using the traditional technique of Tl so much as well as the but recent of OSL. (Author)

  4. The photodetachment cross-section and threshold energy of negative ions in carbon dioxide

    Science.gov (United States)

    Helmy, E. M.; Woo, S. B.

    1974-01-01

    Threshold energy and sunlight photodetachment measurements on negative carbon dioxide ions, using a 2.5 kw light pressure xenon lamp, show that: (1) Electron affinity of CO3(+) is larger than 2.7 e.V. and that an isomeric form of CO3(+) is likely an error; (2) The photodetachment cross section of CO3(-) will roughly be like a step function across the range of 4250 to 2500A, having its threshold energy at 4250A; (3) Sunlight photodetachment rate for CO3(-) is probably much smaller than elsewhere reported; and (4) The probability of having photodetached electrons re-attach to form negative ions is less than 1%. Mass identifying drift tube tests confirm that the slower ion is CO3(-), formed through the O(-) + 2CO2 yields CO3(-) + CO2 reaction.

  5. Raman Spectroscopy of Irradiation Effect in Three Carbon Allotropes Induced by Low Energy B Ions

    Institute of Scientific and Technical Information of China (English)

    FU Yun-Chong; JIN Yun-Fan; YAO Cun-Feng; ZHANG Chong-Hong

    2009-01-01

    Irradiation effect in three carbon allotropes C6o, diamond and highly oriented pyrolytic graphite (HOPG) induced by 170 keV B ions, mainly including the process of the damage creation, is investigated by means of Rarnan spectroscopy technique. The differences on irradiation sensitivity and structural stability for C6o, HOPG and diamond are compared. The analysis results indicate that C6o is the most sensitive for B ions irradiation, diamond is the second one and the structure of HOPG is the most stable under B ion irradiation. The damage cross sections σ of C6o, diamond and HOPG deduced from the Raman spectra are 7.78 × 10-15, 6.38 × 10-15 and 1.31 × 10-15 cm-2, respectively.

  6. Physical and chemical response of 70 MeV carbon ion irradiated Kapton-H polymer

    Indian Academy of Sciences (India)

    H S Virk; P S Chandi; A K Srivastava

    2001-10-01

    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, but for the higher fluences it showed a recovery characteristic. A decrease in band-gap energy of 0.07 eV was observed. The FTIR analysis indicated the high resistance to radiation induced degradation of polymer. The diffraction pattern of Kapton-H indicates that this polymer is semi-crystalline in its nature. In case of irradiated one, there was an average increase of crystallite size by 20%, but diffuse pattern indicates that there was a decrease in crystallinity, which may be attributed to the formation of complex structure induced by the cross-linking of the polymeric chains.

  7. Highly stretchable carbon nanotube transistors enabled by buckled ion gel gate dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Meng-Yin; Chang, Tzu-Hsuan; Ma, Zhenqiang [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Zhao, Juan [School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Xu, Feng; Jacobberger, Robert M.; Arnold, Michael S., E-mail: michael.arnold@wisc.edu [Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2015-08-03

    Deformable field-effect transistors (FETs) are expected to facilitate new technologies like stretchable displays, conformal devices, and electronic skins. We previously demonstrated stretchable FETs based on buckled thin films of polyfluorene-wrapped semiconducting single-walled carbon nanotubes as the channel, buckled metal films as electrodes, and unbuckled flexible ion gel films as the dielectric. The FETs were stretchable up to 50% without appreciable degradation in performance before failure of the ion gel film. Here, we show that by buckling the ion gel, the integrity and performance of the nanotube FETs are extended to nearly 90% elongation, limited by the stretchability of the elastomer substrate. The FETs maintain an on/off ratio of >10{sup 4} and a field-effect mobility of 5 cm{sup 2} V{sup −1} s{sup −1} under elongation and demonstrate invariant performance over 1000 stretching cycles.

  8. 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.

  9. Multi-reference configuration-interaction calculations on multiply charged ions of carbon monosulfide

    Institute of Scientific and Technical Information of China (English)

    Yan Bing; Zhang Yu-Juan

    2013-01-01

    The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell electrons with the scalar relativistic effects are included in the present computations.The spectroscopic constants,dissociation energies,ionization energies for ground and low-lying excited states together with corresponding electronic configurations of ions are obtained,and a good agreement between the present work and existing experiments is found.No theoretical evidence is found for the adiabatically stable CSq+ (q > 2) ions according to the present ab initio calculations.The calculated values for lst-6th ionization energies are 11.25,32.66,64.82,106.25,159.75,and 224.64 eV,respectively.The kinetic energy release data of fragments are provided by the present work for further experimental comparisons.

  10. Improvement on corrosion resistance of NiTi orthopedic materials by carbon plasma immersion ion implantation

    Science.gov (United States)

    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&D). Our corrosion and simulated body fluid tests indicate that either an ion-mixed amorphous carbon coating fabricated by PIII&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 C2H2-PIII&D and C2H2-PIII do not roughen the original flat surface to an extent that can lead to degradation in corrosion resistance.

  11. Mutagenic effects of carbon ion beam irradiations on dry Lotus japonicus seeds

    Science.gov (United States)

    Luo, Shanwei; Zhou, Libin; Li, Wenjian; Du, Yan; Yu, Lixia; Feng, Hui; Mu, Jinhu; Chen, Yuze

    2016-09-01

    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 M1 populations were explored and the dose of 400 Gy was selected as the median lethal dose (LD50) for a large-scale mutant screening. Among 2472 M2 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 M2 populations. No remarkable differences were detected between these two groups, and the total polymorphic rate was 0.567%.

  12. Carbonate ion-enriched hot spring water promotes skin wound healing in nude rats.

    Science.gov (United States)

    Liang, Jingyan; Kang, Dedong; Wang, Yingge; Yu, Ying; Fan, Jianglin; Takashi, En

    2015-01-01

    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. PMID:25671581

  13. 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.

  14. 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.

  15. 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.

  16. Optical properties and oxidation of carbonized and cross-linked structures formed in polycarbonate by plasma immersion ion implantation

    Science.gov (United States)

    Kosobrodova, E.; Kondyurin, A.; Chrzanowski, W.; McCulloch, D. G.; McKenzie, D. R.; Bilek, M. M. M.

    2014-06-01

    At ion fluences higher than 5 · 1015 ions/cm2, plasma immersion ion implantation (PIII) of polycarbonate (PC) results in a formation of a carbonized surface layer. The thickness of this layer is close to the depth of ion penetration. A comparison of PIII treated, spin-coated PC films with pre-treatment thicknesses designed to match and exceed the carbonized layer thickness is employed to study the properties of the carbonised layer independently from the less modified underlying structure. At ion fluencies higher than 1016 ions/cm2, the thinner PC film is completely transformed into an amorphous carbon-like material with no traces of the initial PC structure. The thicker films, however, incorporated two layers: a top carbonised layer and a cross-linked layer below. Compared to the two-layered PC film, the completely carbonized layer was found to have a much higher concentration of Cdbnd O bonds and much lower concentration of O-H bonds after exposure to atmospheric oxygen. The refractive index of the thicker PC films PIII treated with high ion fluencies is close to the refractive index of diamond-like carbon. Anomalous dispersion of the refractive index of the thicker PC films is observed after formation of the carbonised layer. The refractive index of the thinner PC film has normal dispersion at all ion fluences. At ion fluences of 2 · 1016 ions/cm2, both PC films were found to have the same etching rate as polystyrene. Washing in dichloromethane had no effect on the carbonised layer but affected the underlying material in the case of the thicker PC films leading to a wrinkled structure up to ion fluences of 2 · 1016 ions/cm2. At this and higher fluence, areas of an ordered island-like structure were observed.

  17. Radiation biophysical studies with mammalian cells and a modulated carbon ion beam

    International Nuclear Information System (INIS)

    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 G1-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

  18. Fluorescent carbon quantum dot hydrogels for direct determination of silver ions.

    Science.gov (United States)

    Cayuela, A; Soriano, M L; Kennedy, S R; Steed, J W; Valcárcel, M

    2016-05-01

    The paper reports for the first time the direct determination of silver ion (Ag(+)) using luminescent Carbon Quantum Dot hydrogels (CQDGs). Carbon Quantum Dots (CQDs) with different superficial moieties (passivate-CQDs with carboxylic groups, thiol-CQDs and amine-CQDs) were used to prepare hybrid gels using a low molecular weight hydrogelator (LMWG). The use of the gels results in considerable fluorescence enhancement and also markedly influences selectivity. The most selective CQDG system for Ag(+) ion detection proved to be those containing carboxylic groups onto their surface. The selectivity towards Ag(+) ions is possibly due to its flexible coordination sphere compared with other metal ions. This fluorescent sensing platform is based on the strong Ag-O interaction which can quench the photoluminescence of passivate-CQDs (p-CQDs) through charge transfer. The limit of detection (LOD) and quantification (LOQ) of the proposed method were 0.55 and 1.83µgmL(-1), respectively, being applied in river water samples. PMID:26946015

  19. Bucky-gel coated glassy carbon electrodes, for voltammetric detection of femtomolar leveled lead ions.

    Science.gov (United States)

    Wan, Qijin; Yu, Fen; Zhu, Lina; Wang, Xiaoxia; Yang, Nianjun

    2010-10-15

    Femtomolar (fM) leveled lead ions were electrochemically detected using a bucky-gel coated glassy carbon electrode and differential pulse anodic stripping voltammetry. The bucky-gel was composed of dithizone, ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate), and multi-walled carbon nanotubes (MWCNTs). The fabrication of the bucky-gel coated electrode was optimized. The modified electrode was characterized with voltammetry, electrochemical impedance spectroscopy, and chronoamperometry. After the accumulation of lead ions into the bucky-gel modified electrode at -1.2V vs. saturated calomel electrode (SCE) for 5 min in a pH 4.4 sodium acetate-acetate acid buffer solution, differential pulse anodic stripping voltammograms of the accumulated lead show an anodic wave at -0.58 V. The anodic peak current is detectable for lead ions in the concentration range from 1.0 μM down to 500 fM. The detection limit is calculated to be 100 fM. The proposed method was successfully applied for the detection of lead ions in lake water. PMID:20875583

  20. A numerical method to optimise the spatial dose distribution in carbon ion radiotherapy planning.

    Science.gov (United States)

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

    2015-09-01

    The authors describe a numerical algorithm to optimise the entrance spectra of a composition of pristine carbon ion beams which delivers a pre-assumed dose-depth profile over a given depth range within the spread-out Bragg peak. The physical beam transport model is based on tabularised data generated using the SHIELD-HIT10A Monte-Carlo code. Depth-dose profile optimisation is achieved by minimising the deviation from the pre-assumed profile evaluated on a regular grid of points over a given depth range. This multi-dimensional minimisation problem is solved using the L-BFGS-B algorithm, with parallel processing support. Another multi-dimensional interpolation algorithm is used to calculate at given beam depths the cumulative energy-fluence spectra for primary and secondary ions in the optimised beam composition. Knowledge of such energy-fluence spectra for each ion is required by the mixed-field calculation of Katz's cellular Track Structure Theory (TST) that predicts the resulting depth-survival profile. The optimisation algorithm and the TST mixed-field calculation are essential tools in the development of a one-dimensional kernel of a carbon ion therapy planning system. All codes used in the work are generally accessible within the libamtrack open source platform.

  1. Potential energy, force distribution and oscillatory motion of chloride ion inside electrically charged carbon nanotubes

    Science.gov (United States)

    Sadeghi, F.; Ansari, R.; Darvizeh, M.

    2016-06-01

    In this research, a continuum-based model is presented to explore potential energy, force distribution and oscillatory motion of ions, and in particular chloride ion, inside carbon nanotubes (CNTs) decorated by functional groups at two ends. To perform this, van der Waals (vdW) interactions between ion and nanotube are modeled by the 6-12 Lennard-Jones (LJ) potential, whereas the electrostatic interactions between ion and functional groups are modeled by the Coulomb potential and the total interactions are analytically derived by summing the vdW and electrostatic interactions. Making the assumption that carbon atoms and charge of functional groups are all uniformly distributed over the nanotube surface and the two ends of nanotube, respectively, a continuum approach is utilized to evaluate the related interactions. Based on the actual force distribution, the equation of motion is also solved numerically to arrive at the time history of displacement and velocity of inner core. With respect to the proposed formulations, comprehensive studies on the variations of potential energy and force distribution are carried out by varying functional group charge and nanotube length. Moreover, the effects of these parameters together with initial conditions on the oscillatory behavior of system are studied and discussed in detail. It is found out that chloride ion escapes more easily from negatively charged CNTs which is followed by uncharged and positively charged ones. It is further shown that the presence of functional groups leads to enhancing the operating frequency of such oscillatory systems especially when the electric charges of ion and functional groups have different signs.

  2. Status of radiation processing dosimetry

    DEFF Research Database (Denmark)

    Miller, A.

    1993-01-01

    Several milestones have marked the field of radiation processing dosimetry since IMRP 7. Among them are the IAEA symposium on High Dose Dosimetry for Radiation Processing and the international Workshops on Dosimetry for Radiation Processing organized by the ASTM. Several standards have been...... or are being published by the ASTM in this field, both on dosimetry procedures and on the proper use of specific dosimeter systems. Several individuals are involved in this international cooperation which contribute significantly to the broader understanding of the role of dosimetry in radiation processing....... The importance of dosimetry is emphasized in the standards on radiation sterilization which are currently drafted by the European standards organization CEN and by the international standards organization ISO. In both standards, dosimetry plays key roles in characterization of the facility, in qualification...

  3. Biomass carbon micro/nano-structures derived from ramie fibers and corncobs as anode materials for lithium-ion and sodium-ion batteries

    Science.gov (United States)

    Jiang, Qiang; Zhang, Zhenghao; Yin, Shengyu; Guo, Zaiping; Wang, Shiquan; Feng, Chuanqi

    2016-08-01

    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.

  4. Asymmetric catalytic formation of quaternary carbons by iminium ion trapping of radicals

    Science.gov (United States)

    Murphy, John J.; Bastida, David; Paria, Suva; Fagnoni, Maurizio; Melchiorre, Paolo

    2016-04-01

    An important goal of modern organic chemistry is to develop new catalytic strategies for enantioselective carbon–carbon bond formation that can be used to generate quaternary stereogenic centres. Whereas considerable advances have been achieved by exploiting polar reactivity, radical transformations have been far less successful. This is despite the fact that open-shell intermediates are intrinsically primed for connecting structurally congested carbons, as their reactivity is only marginally affected by steric factors. Here we show how the combination of photoredox and asymmetric organic catalysis enables enantioselective radical conjugate additions to β,β-disubstituted cyclic enones to obtain quaternary carbon stereocentres with high fidelity. Critical to our success was the design of a chiral organic catalyst, containing a redox-active carbazole moiety, that drives the formation of iminium ions and the stereoselective trapping of photochemically generated carbon-centred radicals by means of an electron-relay mechanism. We demonstrate the generality of this organocatalytic radical-trapping strategy with two sets of open-shell intermediates, formed through unrelated light-triggered pathways from readily available substrates and photoredox catalysts—this method represents the application of iminium ion activation (a successful catalytic strategy for enantioselective polar chemistry) within the realm of radical reactivity.

  5. MoS2 coated hollow carbon spheres for anodes of lithium ion batteries

    Science.gov (United States)

    Zhang, Yufei; Wang, Ye; Yang, Jun; Shi, Wenhui; Yang, Huiying; Huang, Wei; Dong, Xiaochen

    2016-06-01

    With the assistance of resorcinol-formaldehyde, MoS2 coated hollow carbon spheres (C@MoS2) were synthesized through a facile hydrothermal route followed by heat and alkali treatments. The measurements indicate that the hollow carbon spheres with an average diameter of 300 nm and shell thickness of 20 nm. And the hollow core are uniformly covered by ultrathin MoS2 nanosheets with a length increased to 400 nm. The unique hollow structure and the synergistic effect between carbon layer and MoS2 nanosheets significantly enhance the rate capability and electrochemical stability of C@MoS2 spheres as anode material of lithium-ion battery. The synthesized C@MoS2 delivered a capacity of 750 mAh g-1 at a current density of 100 mA g-1. More importantly, the C@MoS2 maintained a reversible capacity of 533 mAh g-1 even at a high current density of 1000 mA g-1. The study indicated that MoS2 coated hollow carbon spheres can be promising anode material for next generation high-performance lithium-ion batteries.

  6. Rice paper-derived 3D-porous carbon films for lithium-ion batteries

    International Nuclear Information System (INIS)

    Highlights: ► Carbonization of a rice paper (RP) results in a highly porous free-standing hard carbon film composed of carbon fibers. ► Free-standing LiFePO4@C laminate is prepared through a one-step co-sintering process. ► A RP-based full cell with reversible cycling characteristic is fabricated. -- Abstract: Rice paper (RP) is thermally carbonized in nitrogen to prepare three-dimensionally porous carbon films, which are used for the first time as both a free-standing active anode material and a current collector of a cathode (LiFePO4 here) for lithium-ion batteries. The latter is fabricated through a one-step co-sintering of a Li–Fe–P–O precursor top layer supported on the rice paper. The rate and cycling performances of both these electrodes are found to be rather good or even better than the traditional electrodes due to the three-dimensionally porous structure of the RP-derived carbon. We also design and fabricate an RP-based full cell constructed with the above mentioned anode and cathode together with an RP membrane as the separator. Without using traditional metallic current collectors and separator membranes, such a cell exhibits reversible cycling performance

  7. Carbon cluster ions for a study of the accuracy of ISOLTRAP

    CERN Document Server

    Kellerbauer, A G; Bollen, G; Herfurth, F; Kluge, H J; Kuckein, M; Sauvan, E; Scheidenberger, C; Schweikhard, L

    2003-01-01

    Cyclotron frequency measurements of singly charged carbon clusters $^{12}$C$_{n}^{+}$ were carried out with the ISOLTRAP apparatus. The carbon cluster ions were produced externally by use of laser- induced desorption, fragmentation, and ionization of C$_{60}$ fullerenes. They were injected into and stored in the Penning trap system. The observation of carbon clusters of different sizes has provided detailed insight into the final mass uncertainty achievable with ISOLTRAP and yielded a value of $u(m)/m = 8 \\times 10^{-9}$. Since the unified atomic mass unit is defined as 1/12 the mass of the $^{12}$C atom, ISOLTRAP can now be used to carry out absolute mass measurements.

  8. Fabrication and evaluation of an electrodialytic carbonate eluent generator for ion chromatography.

    Science.gov (United States)

    Shen, Guobin; Lu, Yifei; Chen, Feifei; Zhang, Feifang; Yang, Bingcheng

    2016-10-01

    An electrodialytic potassium carbonate eluent generator and its associated potassium bicarbonate eluent generator have been fabricated for ion chromatography (IC). The device can withstand high backpressure up to ∼32MPa and no observable leakage under such pressure is found during 2h. In the range of 0-13.7mM, potassium carbonate concentration can be generated linearly with the applied current with a slope that is essentially Faradaic. At least 10mM potassium carbonate can be online changed into 10mM potassium bicarbonate via a potassium bicarbonate eluent generator, which offers an easy way to manipulate the separation selectivity. When coupled with IC system, the device demonstrated good reproducibility indicated by less than 0.52% of the relative standard deviation of the retention times.

  9. Hard Carbon Fibers Pyrolyzed from Wool as High-Performance Anode for Sodium-Ion Batteries

    Science.gov (United States)

    Zhu, Xiaoming; Li, Qian; Qiu, Shen; Liu, Xiaoling; Xiao, Lifen; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2016-08-01

    In this paper, we first demonstrate that the wool from worn-out clothes can serve as a low-cost and easy-to-collect precursor to preparing high-performance hard carbons for Na-ion batteries. Morphological characterizations demonstrate that this wool-derived hard carbon presents well-defined and homogeneously dispersed fiber networks. X-ray diffraction results combined with high-resolution transmission electron microscopy analysis reveal that the interlayer space (d(002)) of the graphitic layers is 0.376 nm, sufficient for Na insertion into the stacked graphene layers. Electrochemical results show that the wool-derived hard carbon can deliver a high capacity of 303 mAh g-1 and excellent cycle stability over 80 cycles. This satisfactory electrochemical performance and easy synthetic procedure make it a promising anode material for practical SIBs.

  10. 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.

  11. Impact of electrochemical cycling on the tensile properties of carbon fibres for structural lithium-ion composite batteries

    OpenAIRE

    Jacques, Eric; Kjell, Maria H.; Zenkert, Dan; Lindbergh, Göran; Behm, Mårten; Willgert, Markus

    2012-01-01

    Carbon fibres are particularly well suited for use in a multifunctional lightweight design of a structural composite material able to store energy as a lithium-ion battery. The fibres will in this case act as both a high performance structural reinforcement and one of the battery electrodes. However, the electrochemical cycling consists of insertions and extractions of lithium ions in the microstructure of carbon fibres and its impact on the mechanical performance is unknown. This study inves...

  12. Fluence measurements applied to 5-20 MeV/amu ion beam dosimetry by simultaneous use of a total-absorption calorimeter and a Faraday cup

    CERN Document Server

    Kojima, T; Takizawa, H; Tachibana, H; Tanaka, R

    1998-01-01

    A Faraday cup was fabricated for measuring the beam current of a few tens MeV/amu ion beams of the TIARA AVF cyclotron. It has been applied as a beam monitor for studying the characteristics of film dosimeters that are well-established for high doses of sup 6 sup 0 Co gamma-rays and 1 to 10 MeV electrons. A total absorption calorimeter designed to measure energy fluence has also been tested for estimating the uncertainty in fluence measurement of 5-20 MeV/amu ion beams, by simultaneous use of the calorimeter and the Faraday cup in a broad uniform fluence field. The estimated fluence was evaluated on the basis of nominal particle energy values derived from the cyclotron acceleration parameters. The average ratio of the measured fluence values to the estimated values is 1.024, and the average precision is within +-2% at a 68% confidence level, for most of the ion beams with a range of kinetic energy per nucleon, 5-20 MeV/amu, at an integrated charge above 5 nC/cm sup 2.

  13. Mixed ion-exchanger chemically modified carbon paste ion-selective electrodes for determination of triprolidine hydrochloride

    OpenAIRE

    Yousry M. Issa; Fekria M. Abu Attia; Nahla S. Ismail

    2010-01-01

    Triprolidine hydrochloride (TpCl) ion-selective carbon paste electrodes were constructed using Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA as ion-exchangers. The two electrodes revealed Nernstian responses with slopes of 58.4 and 58.1 mV decade−1 at 25 °C in the ranges 6 × 10−6–1 × 10−2 and 2 × 10−5–1 × 10−2 M for Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA, respectively. The potentials of these electrodes were independent of pH in the ranges of 2.5–7.0 and 4.5–7.0, and detection limits were 6 × 10−6 and 1 × 10−5 M ...

  14. Dosimetry in diagnostic radiology

    International Nuclear Information System (INIS)

    Dosimetry is an area of increasing importance in diagnostic radiology. There is a realisation amongst health professionals that the radiation dose received by patients from modern X-ray examinations and procedures can be at a level of significance for the induction of cancer across a population, and in some unfortunate instances, in the acute damage to particular body organs such as skin and eyes. The formulation and measurement procedures for diagnostic radiology dosimetry have recently been standardised through an international code of practice which describes the methodologies necessary to address the diverging imaging modalities used in diagnostic radiology. Common to all dosimetry methodologies is the measurement of the air kerma from the X-ray device under defined conditions. To ensure the accuracy of the dosimetric determination, such measurements need to be made with appropriate instrumentation that has a calibration that is traceable to a standards laboratory. Dosimetric methods are used in radiology departments for a variety of purposes including the determination of patient dose levels to allow examinations to be optimized and to assist in decisions on the justification of examination choices. Patient dosimetry is important for special cases such as for X-ray examinations of children and pregnant patients. It is also a key component of the quality control of X-ray equipment and procedures.

  15. Dosimetry in diagnostic radiology.

    Science.gov (United States)

    Meghzifene, Ahmed; Dance, David R; McLean, Donald; Kramer, Hans-Michael

    2010-10-01

    Dosimetry is an area of increasing importance in diagnostic radiology. There is a realisation amongst health professionals that the radiation dose received by patients from modern X-ray examinations and procedures can be at a level of significance for the induction of cancer across a population, and in some unfortunate instances, in the acute damage to particular body organs such as skin and eyes. The formulation and measurement procedures for diagnostic radiology dosimetry have recently been standardised through an international code of practice which describes the methodologies necessary to address the diverging imaging modalities used in diagnostic radiology. Common to all dosimetry methodologies is the measurement of the air kerma from the X-ray device under defined conditions. To ensure the accuracy of the dosimetric determination, such measurements need to be made with appropriate instrumentation that has a calibration that is traceable to a standards laboratory. Dosimetric methods are used in radiology departments for a variety of purposes including the determination of patient dose levels to allow examinations to be optimized and to assist in decisions on the justification of examination choices. Patient dosimetry is important for special cases such as for X-ray examinations of children and pregnant patients. It is also a key component of the quality control of X-ray equipment and procedures. PMID:20655679

  16. Dosimetry and Calibration Section

    International Nuclear Information System (INIS)

    The two tasks of the Dosimetry and Calibration Section at CERN are the Individual Dosimetry Service which assures the personal monitoring of about 5000 persons potentially exposed to ionizing radiation at CERN, and the Calibration Laboratory which verifies all the instruments and monitors. This equipment is used by the sections of the RP Group for assuring radiation protection around CERN's accelerators, and by the Environmental Section of TISTE. In addition, nearly 250 electronic and 300 quartz fibre dosimeters, employed in operational dosimetry, are calibrated at least once a year. The Individual Dosimetry Service uses an extended database (INDOS) which contains information about all the individual doses ever received at CERN. For most of 1997 it was operated without the support of a database administrator as the technician who had assured this work retired. The Software Support Section of TIS-TE took over the technical responsibility of the database, but in view of the many other tasks of this Section and the lack of personnel, only a few interventions for solving immediate problems were possible

  17. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  18. Ion irradiation of electronic-type-separated single wall carbon nanotubes: A model for radiation effects in nanostructured carbon

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Jamie E. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Cress, Cory D.; Messenger, Scott R.; Weaver, Brad D. [Electronics Science and Technology Division, United States Naval Research Laboratory, Washington, D.C. 20375 (United States); Helenic, Alysha R.; Landi, Brian J. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Chemical and Biomedical Engineering, Rochester Institute of Technology, Rochester, New York 14623 (United States); Schauerman, Chris M. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Golisano Institute of Sustainability, Rochester Institute of Technology, Rochester, New York 14623 (United States); DiLeo, Roberta A.; Cox, Nathanael D. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Microsystems Engineering, Rochester Institute of Technology, Rochester, New York 14623 (United States); Hubbard, Seth M. [NanoPower Research Laboratory, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Microsystems Engineering, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Physics, Rochester Institute of Technology, Rochester, New York 14623 (United States)

    2012-08-01

    The structural and electrical properties of electronic-type-separated (metallic and semiconducting) single wall carbon nanotube (SWCNT) thin-films have been investigated after irradiation with 150 keV {sup 11}B{sup +} and 150 keV {sup 31}P{sup +} with fluences ranging from 10{sup 12} to 10{sup 15} ions/cm{sup 2}. Raman spectroscopy results indicate that the ratio of the Raman D to G Prime band peak intensities (D/G Prime ) is a more sensitive indicator of SWCNT structural modification induced by ion irradiation by one order of magnitude compared to the ratio of the Raman D to G band peak intensities (D/G). The increase in sheet resistance (R{sub s}) of the thin-films follows a similar trend as the D/G Prime ratio, suggesting that the radiation induced variation in bulk electrical transport for both electronic-types is equal and related to localized defect generation. The characterization results for the various samples are compared based on the displacement damage dose (DDD) imparted to the sample, which is material and damage source independent. Therefore, it is possible to extend the analysis to include data from irradiation of transferred CVD-graphene films on SiO{sub 2}/Si substrates using 35 keV C{sup +} ions, and compare the observed changes at equivalent levels of ion irradiation-induced damage to that observed in the SWCNT thin-film samples. Ultimately, a model is developed for the prediction of the radiation response of nanostructured carbon materials based on the DDD for any incident ion with low-energy recoil spectra. The model is also related to the defect concentration, and subsequently the effective defect-to-defect length, and yields a maximum defect concentration (minimum defect-to-defect length) above which the bulk electrical transport properties in SWCNT thin-films and large graphene-based electronic devices rapidly degrade when exposed to harsh environments.

  19. Electron emission and molecular fragmentation during hydrogen and deuterium ion impact on carbon surfaces

    Science.gov (United States)

    Qayyum, A.; Schustereder, W.; Mair, C.; Scheier, P.; Märk, T. D.; Cernusca, S.; Winter, HP.; Aumayr, F.

    2003-03-01

    Molecular fragmentation and electron emission during hydrogen ion impact on graphite surfaces has been investigated in the eV to keV impact energy region typical for fusion edge plasma conditions. As a target surface graphite tiles for the Tokamak experiment Tore Supra in CEA-Cadarache/France and highly oriented pyrolytic graphite (HOPG) have been used. For both surfaces studied, the experimentally observed threshold for electron emission is at about 50 eV/amu impact energy. Electron emission from the high conductivity side of the carbon tile is 15-20% less as compared to its low conductivity side, whereas results for HOPG are generally between these two cases. Deuterium and hydrogen ions are almost equally effective in liberating electrons from graphite when comparing results for the same impact velocity. Surface-induced dissociation of deuterium ions D 3+ upon impact on Tore Supra graphite tiles, in the collision energy range of 20-100 eV, produced only atomic fragment ions D +. The other possible fragment ion D 2+ could not be observed.

  20. 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.

  1. Electron emission and molecular fragmentation during hydrogen and deuterium ion impact on carbon surfaces

    International Nuclear Information System (INIS)

    Molecular fragmentation and electron emission during hydrogen ion impact on graphite surfaces has been investigated in the eV to keV impact energy region typical for fusion edge plasma conditions. As a target surface graphite tiles for the Tokamak experiment Tore Supra in CEA-Cadarache/France and highly oriented pyrolytic graphite (HOPG) have been used. For both surfaces studied, the experimentally observed threshold for electron emission is at about 50 eV/amu impact energy. Electron emission from the high conductivity side of the carbon tile is 15-20% less as compared to its low conductivity side, whereas results for HOPG are generally between these two cases. Deuterium and hydrogen ions are almost equally effective in liberating electrons from graphite when comparing results for the same impact velocity. Surface-induced dissociation of deuterium ions D3+ upon impact on Tore Supra graphite tiles, in the collision energy range of 20-100 eV, produced only atomic fragment ions D+. The other possible fragment ion D2+ could not be observed

  2. Removal of some metal ions by activated carbon prepared from Phaseolus aureus hulls

    Energy Technology Data Exchange (ETDEWEB)

    Rao, M. Madhava; Ramana, D.K.; Seshaiah, K. [Analytical and Environmental Chemistry Division, Department of Chemistry, Sri Venkateswara University, Tirupati 517 502 (India); Wang, M.C., E-mail: mcwang@cyut.edu.tw [Department of Environmental Engineering and Management, Chaoyang University of Technology, Wufong Township 41349, Taichung County, Taiwan (China); Chien, S.W. Chang [Department of Environmental Engineering and Management, Chaoyang University of Technology, Wufong Township 41349, Taichung County, Taiwan (China)

    2009-07-30

    Removal of lead [Pb(II)], zinc [Zn(II)], copper [Cu(II)], and cadmium [Cd(II)] from aqueous solutions using activated carbon prepared from Phaseolus aureus hulls (ACPAH), an agricultural waste was studied. The influence of various parameters such as effect of pH, contact time, adsorbent dose, and initial concentration of metal ions on the removal was evaluated by batch method. The removal of metal ions by ACPAH was pH dependent and the optimum pH values were 7.0, 8.0, 7.0 and 6.0 for Cu(II), Cd(II), Zn(II), and Pb(II), respectively. The sorption isotherms were studied using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models. The maximum adsorption capacity values of ACPAH for metal ions were 21.8 mg g{sup -1} for Pb(II), 21.2 mg g{sup -1} for Zn(II), 19.5 mg g{sup -1} for Cu(II), and 15.7 mg g{sup -1} for Cd(II). The experiments demonstrated that the removal of metal ions followed the pseudo-second-order kinetic model. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.

  3. 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.

  4. 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.

  5. 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.

  6. Low contact resistance carbon thin film modified current collectors for lithium Ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shi-Kun; Chiu, Kuo-Feng, E-mail: kfchiu@fcu.edu.tw; Su, Shih-Hsuan; Liu, Shih-Hsien; Hou, Kai Hsiang; Leu, Hoang-Jyh; Hsiao, Chung-Chun

    2014-12-01

    Carbon films have been synthesized by chemical vapor deposition (CVD) on AISI 304 stainless steel (304SS) sheets with various C{sub 2}H{sub 2}/H{sub 2} flow ratios at 810 °C. The films exhibit three different morphologies and structures: filament, sphere and transition types at different C{sub 2}H{sub 2}/H{sub 2} flow ratios, as characterized by scanning electron microscopy, X-ray diffraction and Raman spectroscopy. It was found that the degree of graphitization increased with decreasing C{sub 2}H{sub 2}/H{sub 2} flow ratios. The carbon film modified 304SS sheets were used as cathode current collectors and coated with an active layer containing LiMn{sub 2}O{sub 4} active materials, conducting additives and binders for lithium ion batteries. The electrochemical properties of these LiMn{sub 2}O{sub 4} cells with bare and carbon film modified current collectors were investigated. Under high current operation, such as 3000 mA/g, the capacity of the LiMn{sub 2}O{sub 4} cell with transition type carbon film modified current collector is 55% higher than the cell with bare current collector. The enhanced performances of high current density charge–discharge cycles can be attributed to the reduced contact resistance and improved charge transfer efficiency provided by the transition type carbon film modified current collectors. - Highlights: • Carbon films were synthesized by CVD on 304SS sheets. • The carbon film modified 304SS sheets were used as cathode current collectors. • The carbon film modified current collectors improved charge transfer efficiency.

  7. 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.

  8. Carbon matrix/SiNWs heterogeneous block as improved reversible anodes material for lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    Yao; Wang; Long; Ren; Yundan; Liu; Xuejun; Liu; Kai; Huang; Xiaolin; Wei; Jun; Li; Xiang; Qi; Jianxin; Zhong

    2014-01-01

    A novel carbon matrix/silicon nanowires(SiNWs) heterogeneous block was successfully produced by dispersing SiNWs into templated carbon matrix via a modified evaporation induced self-assembly method. The heterogeneous block was determined by X-ray diffraction, Raman spectra and scanning electron microscopy. As an anode material for lithium batteries, the block was investigated by cyclic voltammograms(CV), charge/discharge tests, galvanostatic cycling performance and A. C. impedance spectroscopy. We show that the SiNWs disperse into the framework, and are nicely wrapped by the carbon matrix. The heterogeneous block exhibits superior electrochemical reversibility with a high specific capacity of 529.3 mAh/g in comparison with bare SiNWs anode with merely about 52.6 mAh/g capacity retention. The block presents excellent cycle stability and capacity retention which can be attributed to the improvement of conductivity by the existence of carbon matrix and the enhancement of ability to relieve the large volume expansion of SiNWs during the lithium insertion/extraction cycle. The results indicate that the as-prepared carbon matrix/SiNWs heterogeneous block can be an attractive and potential anode material for lithium-ion battery applications.

  9. Microstructure of carbon derived from mangrove charcoal and its application in Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tao [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100083 (China); Luo Ruiying, E-mail: ryluo@buaa.edu.c [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100083 (China); Qiao Wenming [College of Chemical Engineering, East China University of Science and Technology, Shanghai 200237 (China); Yoon, Seong-Ho; Mochida, Isao [Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

    2010-02-01

    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{sup -1}, the high first-cycle coulombic efficiency of 73.7%, good rate and cyclic capability and PC-based electrolyte compatibility. {sup 7}Li nuclear magnetic resonance (NMR) spectra of fully lithiated mangrove charcoal-derived carbons indicated the co-existence of three Li species.

  10. Bio-Derived, Binderless, Hierarchically Porous Carbon Anodes for Li-ion Batteries.

    Science.gov (United States)

    Campbell, Brennan; Ionescu, Robert; Favors, Zachary; Ozkan, Cengiz S; Ozkan, Mihrimah

    2015-09-29

    Here we explore the electrochemical performance of pyrolyzed skins from the species A. bisporus, also known as the Portobello mushroom, as free-standing, binder-free, and current collector-free Li-ion battery anodes. At temperatures above 900 °C, the biomass-derived carbon nanoribbon-like architectures undergo unique processes to become hierarchically porous. During heat-treatment, the oxygen and heteroatom-rich organics and potassium compounds naturally present in the mushroom skins play a mutual role in creating inner void spaces throughout the resulting carbon nanoribbons, which is a process analogous to KOH-activation of carbon materials seen in literature. The pores formed in the pyrolytic carbon nanoribbons range in size from sub-nanometer to tens of nanometers, making the nanoribbons micro, meso, and macroporous. Detailed studies were conducted on the carbon nanoribbons using SEM and TEM to study morphology, as well as XRD and EDS to study composition. The self-supporting nanoribbon anodes demonstrate significant capacity increase as they undergo additional charge/discharge cycles. After a pyrolysis temperature of 1100 °C, the pristine anodes achieve over 260 mAh/g after 700 cycles and a Coulombic efficiency of 101.1%, without the use of harmful solvents or chemical activation agents.

  11. Comparison of Individual Radiosensitivity to γ-Rays and Carbon Ions.

    Science.gov (United States)

    Shim, Grace; Normil, Marie Delna; Testard, Isabelle; Hempel, William M; Ricoul, Michelle; Sabatier, Laure

    2016-01-01

    Carbon ions are an up-and-coming ion species, currently being used in charged particle radiotherapy. As it is well established that there are considerable interindividual differences in radiosensitivity in the general population that can significantly influence clinical outcomes of radiotherapy, we evaluate the degree of these differences in the context of carbon ion therapy compared with conventional radiotherapy. In this study, we evaluate individual radiosensitivity following exposure to carbon-13 ions or γ-rays in peripheral blood lymphocytes of healthy individuals based on the frequency of ionizing radiation (IR)-induced DNA double strand breaks (DSBs) that was either misrepaired or left unrepaired to form chromosomal aberrations (CAs) (simply referred to here as DSBs for brevity). Levels of DSBs were estimated from the scoring of CAs visualized with telomere/centromere-fluorescence in situ hybridization (TC-FISH). We examine radiosensitivity at the dose of 2 Gy, a routinely administered dose during fractionated radiotherapy, and we determined that a wide range of DSBs were induced by the given dose among healthy individuals, with highly radiosensitive individuals harboring more IR-induced breaks in the genome than radioresistant individuals following exposure to the same dose. Furthermore, we determined the relative effectiveness of carbon irradiation in comparison to γ-irradiation in the induction of DSBs at each studied dose (isodose effect), a quality we term "relative dose effect" (RDE). This ratio is advantageous, as it allows for simple comparison of dose-response curves. At 2 Gy, carbon irradiation was three times more effective in inducing DSBs compared with γ-irradiation (RDE of 3); these results were confirmed using a second cytogenetic technique, multicolor-FISH. We also analyze radiosensitivity at other doses (0.2-15 Gy), to represent hypo- and hyperfractionation doses and determined that RDE is dose dependent: high ratios at low doses

  12. Comparison of Individual Radiosensitivity to γ-Rays and Carbon Ions

    Science.gov (United States)

    Shim, Grace; Normil, Marie Delna; Testard, Isabelle; Hempel, William M.; Ricoul, Michelle; Sabatier, Laure

    2016-01-01

    Carbon ions are an up-and-coming ion species, currently being used in charged particle radiotherapy. As it is well established that there are considerable interindividual differences in radiosensitivity in the general population that can significantly influence clinical outcomes of radiotherapy, we evaluate the degree of these differences in the context of carbon ion therapy compared with conventional radiotherapy. In this study, we evaluate individual radiosensitivity following exposure to carbon-13 ions or γ-rays in peripheral blood lymphocytes of healthy individuals based on the frequency of ionizing radiation (IR)-induced DNA double strand breaks (DSBs) that was either misrepaired or left unrepaired to form chromosomal aberrations (CAs) (simply referred to here as DSBs for brevity). Levels of DSBs were estimated from the scoring of CAs visualized with telomere/centromere-fluorescence in situ hybridization (TC-FISH). We examine radiosensitivity at the dose of 2 Gy, a routinely administered dose during fractionated radiotherapy, and we determined that a wide range of DSBs were induced by the given dose among healthy individuals, with highly radiosensitive individuals harboring more IR-induced breaks in the genome than radioresistant individuals following exposure to the same dose. Furthermore, we determined the relative effectiveness of carbon irradiation in comparison to γ-irradiation in the induction of DSBs at each studied dose (isodose effect), a quality we term “relative dose effect” (RDE). This ratio is advantageous, as it allows for simple comparison of dose–response curves. At 2 Gy, carbon irradiation was three times more effective in inducing DSBs compared with γ-irradiation (RDE of 3); these results were confirmed using a second cytogenetic technique, multicolor-FISH. We also analyze radiosensitivity at other doses (0.2–15 Gy), to represent hypo- and hyperfractionation doses and determined that RDE is dose dependent: high ratios at low

  13. Carbon aerogel with 3-D continuous skeleton and mesopore structure for lithium-ion batteries application

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoqing, E-mail: yxq-886@163.com [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Huang, Hong [Instrumental Analysis and Research Center, Sun Yat-sen University, Guangzhou 510275 (China); Zhang, Guoqing; Li, Xinxi [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Wu, Dingcai [Materials Science Institute, PCFM Laboratory, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Fu, Ruowen, E-mail: cesfrw@mail.sysu.edu.cn [Materials Science Institute, PCFM Laboratory, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2015-01-15

    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{sup −1} for 80 cycles, much higher than the theoretical capacity of commercial graphite (372 mAh g{sup −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{sup 2} g{sup −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.

  14. 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...

  15. The effect of carbon impurities on molybdenum surface morphology evolution under high-flux low-energy helium ion irradiation

    Science.gov (United States)

    Tripathi, J. K.; Novakowski, T. J.; Gonderman, S.; Bharadwaj, N.; Hassanein, A.

    2016-09-01

    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 CH4 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 × 1024 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.

  16. Chemically Modulated Carbon Nitride Nanosheets for Highly Selective Electrochemiluminescent Detection of Multiple Metal-ions.

    Science.gov (United States)

    Zhou, Zhixin; Shang, Qiuwei; Shen, Yanfei; Zhang, Linqun; Zhang, Yuye; Lv, Yanqin; Li, Ying; Liu, Songqin; Zhang, Yuanjian

    2016-06-01

    Chemical structures of two-dimensional (2D) nanosheet can effectively control the properties thus guiding their applications. Herein, we demonstrate that carbon nitride nanosheets (CNNS) with tunable chemical structures can be obtained by exfoliating facile accessible bulk carbon nitride (CN) of different polymerization degree. Interestingly, the electrochemiluminescence (ECL) properties of as-prepared CNNS were significantly modulated. As a result, unusual changes for different CNNS in quenching of ECL because of inner filter effect/electron transfer and enhancement of ECL owing to catalytic effect were observed by adding different metal ions. On the basis of this, by using various CNNS, highly selective ECL sensors for rapid detecting multiple metal-ions such as Cu(2+), Ni(2+), and Cd(2+) were successfully developed without any labeling and masking reagents. Multiple competitive mechanisms were further revealed to account for such enhanced selectivity in the proposed ECL sensors. The strategy of preparing CNNS with tunable chemical structures that facilely modulated the optical properties would open a vista to explore 2D carbon-rich materials for developing a wide range of applications such as sensors with enhanced performances.

  17. Natural sisal fibers derived hierarchical porous activated carbon as capacitive material in lithium ion capacitor

    Science.gov (United States)

    Yang, Zhewei; Guo, Huajun; Li, Xinhai; Wang, Zhixing; Yan, Zhiliang; Wang, Yansen

    2016-10-01

    Lithium-ion capacitor (LIC) is a novel advanced electrochemical energy storage (EES) system bridging gap between lithium ion battery (LIB) and electrochemical capacitor (ECC). In this work, we report that sisal fiber activated carbon (SFAC) was synthesized by hydrothermal treatment followed by KOH activation and served as capacitive material in LIC for the first time. Different particle structure, morphology, specific surface area and heteroatoms affected the electrochemical performance of as-prepared materials and corresponding LICs. When the mass ratio of KOH to char precursor was 2, hierarchical porous structured SFAC-2 was prepared and exhibited moderate specific capacitance (103 F g-1 at 0.1 A g-1), superior rate capability and cyclic stability (88% capacity retention after 5000 cycles at 1 A g-1). The corresponding assembled LIC (LIC-SC2) with optimal comprehensive electrochemical performance, displayed the energy density of 83 Wh kg-1, the power density of 5718 W kg-1 and superior cyclic stability (92% energy density retention after 1000 cycles at 0.5 A g-1). It is worthwhile that the source for activated carbon is a natural and renewable one and the synthesis method is eco-friendly, which facilitate that hierarchical porous activated carbon has potential applications in the field of LIC and other energy storage systems.

  18. Chemically Modulated Carbon Nitride Nanosheets for Highly Selective Electrochemiluminescent Detection of Multiple Metal-ions.

    Science.gov (United States)

    Zhou, Zhixin; Shang, Qiuwei; Shen, Yanfei; Zhang, Linqun; Zhang, Yuye; Lv, Yanqin; Li, Ying; Liu, Songqin; Zhang, Yuanjian

    2016-06-01

    Chemical structures of two-dimensional (2D) nanosheet can effectively control the properties thus guiding their applications. Herein, we demonstrate that carbon nitride nanosheets (CNNS) with tunable chemical structures can be obtained by exfoliating facile accessible bulk carbon nitride (CN) of different polymerization degree. Interestingly, the electrochemiluminescence (ECL) properties of as-prepared CNNS were significantly modulated. As a result, unusual changes for different CNNS in quenching of ECL because of inner filter effect/electron transfer and enhancement of ECL owing to catalytic effect were observed by adding different metal ions. On the basis of this, by using various CNNS, highly selective ECL sensors for rapid detecting multiple metal-ions such as Cu(2+), Ni(2+), and Cd(2+) were successfully developed without any labeling and masking reagents. Multiple competitive mechanisms were further revealed to account for such enhanced selectivity in the proposed ECL sensors. The strategy of preparing CNNS with tunable chemical structures that facilely modulated the optical properties would open a vista to explore 2D carbon-rich materials for developing a wide range of applications such as sensors with enhanced performances. PMID:27187874

  19. Specification of carbon ion dose at the National Institute of Radiological Sciences (NIRS)

    International Nuclear Information System (INIS)

    The clinical dose distributions of therapeutic carbon beams, currently used at National Institute of Radiological Sciences (NIRS) Heavy Ion Medical Accelerator in Chiba (HIMAC), are based on in-vitro Human Salivary Gland (HSG) cell survival response and clinical experience from fast neutron radiotherapy. Moderate radiosensitivity of HSG cells is expected to be a typical response of tumours to carbon beams. At first, the biological dose distribution is designed so as to cause a flat biological effect on HSG cells in the spread-out Bragg peak (SOBP) region. Then, the entire biological dose distribution is evenly raised in order to attain a RBE (relative biological effectiveness)=3.0 at a depth where dose-averaged LET (linear energy transfer) is 80 keV/μm. At that point, biological experiments have shown that carbon ions can be expected to have a biological effect identical to fast neutrons, which showed a clinical RBE of 3.0 for fast neutron radiotherapy at NIRS. The resulting clinical dose distribution in this approximation is not dependent on dose level, tumour type or fractionation scheme and thus reduces the unknown parameters in the analysis of the clinical results. The width SOBP and the clinical/physical dose at the center of SOBP specify the dose distribution. The clinical results analyzed in terms of tumor control probability (TCP) were found to show good agreement with the expected RBE value at higher TCP levels. The TCP analysis method was applied for the prospective dose estimation of hypofractionation. (author)

  20. In vivo dosimetry for IMRT

    Science.gov (United States)

    Vial, Philip

    2011-05-01

    In vivo dosimetry has a well established role in the quality assurance of 2D radiotherapy and 3D conformal radiotherapy. The role of in vivo dosimetry for IMRT is not as well established. IMRT introduces a range of technical issues that complicate in vivo dosimetry. The first decade or so of IMRT implementation has largely relied upon pre-treatment phantom based dose verification. During that time, several new devices and techniques for in vivo dosimetry have emerged with the promise of providing the ultimate form of IMRT dose verification. Solid state dosimeters continue to dominate the field of in vivo dosimetry in the IMRT era. In this report we review the literature on in vivo dosimetry for IMRT, with an emphasis on clinical evidence for different detector types. We describe the pros and cons of different detectors and techniques in the IMRT setting and the roles that they are likely to play in the future.

  1. 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

  2. Inhibitory effect of tungstate, molybdate and nitrite ions on the carbon steel pitting corrosion in alkaline formation water containing Cl- ion

    International Nuclear Information System (INIS)

    The pitting corrosion of carbon steel in carbonate-formation water solution in the presence of chloride ions and the effect of addition WO42-, MoO42- and NO2- anions on the pitting corrosion were studied using cyclic voltammetry and potentiostatic current-time measurements and complemented by scan electron microscope (SEM), energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) investigations. Cyclic voltammograms of carbon steel in the presence of chloride ions in carbonate-formation water solution show one anodic peak, corresponding to the formation green rust carbonate and the two cathodic peaks. As the addition of Cl- ions concentration increases, the anodic peak current density increases and pitting potential Epit shifts to more negative potential. It is shown that the rate of pit initiation (ti-1) decreases and the pitting potential Epit moves to more positive direction upon the addition of inorganic anions. It was found that pitting inhibition of carbon steel increases in the sequence: (WO4)2- > (MoO4)2- > (NO2)-

  3. Chromosome inversions in lymphocytes of prostate cancer patients treated with X-rays and carbon ions

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. 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.

  6. The dosimetry of ionizing radiation

    CERN Document Server

    1990-01-01

    A continuation of the treatise The Dosimetry of Ionizing Radiation, Volume III builds upon the foundations of Volumes I and II and the tradition of the preceeding treatise Radiation Dosimetry. Volume III contains three comprehensive chapters on the applications of radiation dosimetry in particular research and medical settings, a chapter on unique and useful detectors, and two chapters on Monte Carlo techniques and their applications.

  7. SnSe/carbon nanocomposite synthesized by high energy ball milling as an anode material for sodium-ion and lithium-ion batteries

    International Nuclear Information System (INIS)

    Graphical abstract: A homogeneous nanocomposite of SnSe and carbon black was synthesised by high energy ball milling and empolyed as an anode material for sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs). The nanocomposite anode exhibits excellent electrochemical performances in both SIBs and LIBs. - Highlights: • A homogeneous nanocomposite of SnSe and carbon black was fabricated by high energy ball milling. • SnSe and carbon black are homogeneously mixed at the nanoscale level. • The SnSe/C anode exhibits excellent electrochemical performances in both SIBs and LIBs. - Abstract: A homogeneous nanocomposite of SnSe and carbon black, denoted as SnSe/C nanocomposite, was fabricated by high energy ball milling and empolyed as a high performance anode material for both sodium-ion batteries and lithium-ion batteries. The X-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy observations confirmed that SnSe in SnSe/C nanocomposite was homogeneously distributed within carbon black. The nanocomposite anode exhibited enhanced electrochemical performances including a high capacity, long cycling behavior and good rate performance in both sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs). In SIBs, an initial capacitiy of 748.5 mAh g−1 was obtained and was maintained well on cycling (324.9 mAh g−1 at a high current density of 500 mA g−1 in the 200 th cycle) with 72.5% retention of second cycle capacity (447.7 mAh g−1). In LIBs, high initial capacities of approximately 1097.6 mAh g−1 was obtained, and this reduced to 633.1 mAh g−1 after 100 cycles at 500 mA g−1

  8. Structure studies of carbon foils with the aim to improve the ability for heavy-ion stripping

    International Nuclear Information System (INIS)

    Slackened carbon stripper foils of 3 to 5 μg/cm2 produced by vacuum evaporation-condensation were graphitized by annealing at about 3300 K with a pulsed laser beam (1.06 μm). An average crystal size of 10 nm was measured by electron diffraction. The texture of the 002-plane is parallel to the surface of the foil as known from slightly annealed carbon foils. Radiation damages caused by high doses of heavy ions dramatically change the crystal structure. Electron diffraction patterns reveal newly formed graphite crystals with their 002-plane perpendicular to the texture. Compared to carbon foils of the same kind, but not graphitized, a lifetime prolongation of a factor of two was achieved for such foils tested in the terminal of the Munich MP tandem. The slope of the curve for heavy-ion transmission through carbon stripper foils varies for foils of the same kind and for different ion-beam conditions. (orig.)

  9. 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....

  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. Heavy metal ion inhibition studies of human, sheep and fish α-carbonic anhydrases.

    Science.gov (United States)

    Demirdağ, Ramazan; Yerlikaya, Emrah; Şentürk, Murat; Küfrevioğlu, Ö İrfan; Supuran, Claudiu T

    2013-04-01

    Carbonic anhydrases (CAs, EC 4.2.1.1) were purified from sheep kidney (sCA IV), from the liver of the teleost fish Dicentrarchus labrax (dCA) and from human erythrocytes (hCA I and hCA II). The purification procedure consisted of a single step affinity chromatography on Sepharose 4B-tyrosine-sulfanilamide. The kinetic parameters of these enzymes were determined for their esterase activity with 4-nitrophenyl acetate as substrate. The following metal ions, Pb(2+), Co(2+), Hg(2+), Cd(2+), Zn(2+), Se(2+), Cu(2+), Al(3+) and Mn(3+) showed inhibitory effects on these enzymes. The tested metal ions inhibited these CAs competitively in the low milimolar/submillimolar range. The susceptibility to various cations inhibitors differs significantly between these vertebrate α-CAs and is probably due to their binding to His64 or the histidine cluster. PMID:22145795

  12. DOSE TO RADIOLOGICAL TECHNOLOGISTS FROM INDUCED RADIONUCLIDES IN CARBON ION RADIOTHERAPY.

    Science.gov (United States)

    Yonai, S; Spano, V

    2016-09-01

    Radioactive nuclides are induced in irradiation devices and patients during high-energy photon and ion beam radiotherapies. These nuclides potentially become sources of exposure to radiation workers. Radiological technologists (RTs) are often required to enter an irradiation room and approach activated devices and patients. In this study, annual doses to RTs working in a carbon ion radiotherapy facility were estimated based on measurements with the Si-semiconductor personal dosemeter. In addition, the time decay of dose around a patient couch after irradiation was obtained by phantom experiments. The annual Hp(10) values for passive and scanned beams were estimated to be 61 and 2 μSv, respectively, when assuming the number of treatments in 2013. These are much lower than the ICRP recommended dose limit for radiation workers. The time-series data of dose to RTs during their work and the time decay of the dose should be helpful for reducing their dose further. PMID:27179122

  13. Dosimetric comparison of carbon ion and X-ray radiotherapy for Stage IIIA non–small cell lung cancer

    Science.gov (United States)

    Kubo, Nobuteru; Saitoh, Jun-ichi; Shimada, Hirofumi; Shirai, Katsuyuki; Kawamura, Hidemasa; Ohno, Tatsuya; Nakano, Takashi

    2016-01-01

    The present study compared the dose–volume histograms of patients with Stage IIIA non–small cell lung cancer (NSCLC) treated with carbon ion radiotherapy with those of patients treated with X-ray radiotherapy. Patients with Stage IIIA NSCLC (n = 10 patients for each approach) were enrolled. Both radiotherapy plans were calculated with the same targets and organs at risk on the same CT. The treatment plan for the prophylactic lymph node and primary tumor (PTV1) delivered 40 Gy for X-ray radiotherapy and 40 Gy (relative biological effectiveness; RBE) for carbon ion radiotherapy. The total doses for the primary tumor and clinically positive lymph nodes (PTV2) were 60 Gy for X-ray radiotherapy and 60 Gy (RBE) for carbon ion radiotherapy. The homogeneity indexes for PTV1 and PTV2 were superior for carbon ion radiotherapy in comparison with X-ray radiotherapy (PTV1, 0.57 vs 0.65, P = 0.009; PTV2, 0.07 vs 0.16, P = 0.005). The normal lung mean dose, V5, V10 and V20 for carbon ion radiotherapy were 7.7 Gy (RBE), 21.4%, 19.7% and 17.0%, respectively, whereas the corresponding doses for X-ray radiotherapy were 11.9 Gy, 34.9%, 26.6% and 20.8%, respectively. Maximum spinal cord dose, esophageal maximum dose and V50, and bone V10, V30 and V50 were lower with carbon ion radiotherapy than with X-ray radiotherapy. The present study indicates that carbon ion radiotherapy provides a more homogeneous target dose and a lower dose to organs at risk than X-ray radiotherapy for Stage IIIA non–small cell lung cancer. PMID:27242341

  14. 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

  15. Relative biological effects of carbon ion beams on mouse intestinal crypts

    Energy Technology Data Exchange (ETDEWEB)

    Basaki, Kiyoshi; Abe, Yoshinao [Hirosaki Univ., Aomori (Japan). School of Medicine; Tatsuzaki, Hideo; Akaizawa, Takashi; Ando, Soichiro; Ando, Koichi

    1998-03-01

    The relative biological effect (RBE) of carbon ion beams on mouse intestinal crypt cells were studied. Survival fractions of apoptotic sensitive cells, mitotic delay and colony assay were used for endpoints. Female C3H mice were total body irradiated using a carbon ion beam (290 MeV/u, 6 cm SOBP) at the National Institute of Radiological Science. For counting apoptosis and mitosis, the animals were irradiated either at LET of 70 keV/mm or 40 keV/mm. Fifteen minutes after irradiation, the mice received vincristine sulfate (0.8 mg/kg) and were sacrificed 2 hours and 45 minutes later. For colony assay, the animals were irradiated at an LET of 70 keV/mm and were sacrificed 3.5 days later. Jejunum were excised, fixed and cut into slices. The slides were stained with Hematoxylin and Eosin. Apoptosis-pyknotic cell- and mitosis were counted and survival fractions of apoptotic sensitive cells and mitotic delay time were obtained. The number of colonies were counted and survival fractions per circumference were obtained. Using these endpoints, RBEs were obtained. For survival fractions of apoptotic sensitive cells, no LET difference was observed and RBE was 1.7. For mitotic delay time, RBE was 2.3 and 1.7 at an LET of 70 keV/mm and 40 keV/mm, respectively. For colony assay, the RBE was 2.0-2.1. The different RBEs from three endpoints of the jejunal crypt may reflect each nature of the radiosensitivity to the carbon ion beam. In summary that mitotic delay time exhibited the same RBE as colony assay and RBE regarding apoptosis was less than those RBEs. (author)

  16. 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.

  17. Influence of Multiple Genetic Polymorphisms on Genitourinary Morbidity After Carbon Ion Radiotherapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Purpose: To investigate the genetic risk of late urinary morbidity after carbon ion radiotherapy in prostate cancer patients. Methods and Materials: A total of 197 prostate cancer patients who had undergone carbon ion radiotherapy were evaluated for urinary morbidity. The distribution of patients with dysuria was as follows: Grade 0, 165; Grade 1, 28; and Grade 2, 4 patients. The patients were divided (2:1) consecutively into the training and test sets and then categorized into control (Grade 0) and case (Grade 1 or greater) groups. First, 450 single nucleotide polymorphisms (SNPs) in 118 candidate genes were genotyped in the training set. The associations between the SNP genotypes and urinary morbidity were assessed using Fisher's exact test. Then, various combinations of the markers were tested for their ability to maximize the area under the receiver operating characteristics (AUC-ROC) curve analysis results. Finally, the test set was validated for the selected markers. Results: When the SNP markers in the SART1, ID3, EPDR1, PAH, and XRCC6 genes in the training set were subjected to AUC-ROC curve analysis, the AUC-ROC curve reached a maximum of 0.86. The AUC-ROC curve of these markers in the test set was 0.77. The SNPs in these five genes were defined as 'risk genotypes.' Approximately 90% of patients in the case group (Grade 1 or greater) had three or more risk genotypes. Conclusions: Our results have shown that patients with late urinary morbidity after carbon ion radiotherapy can be stratified according to the total number of risk genotypes they harbor

  18. Low pressure carbon dioxide solubility in pure electrolyte solvents for lithium-ion batteries as a function of temperature. Measurement and prediction

    OpenAIRE

    Anouti, M.; Dougassa, Y.R.; Tessier, C.; El Ouatani, L.; Johan JACQUEMIN

    2012-01-01

    Experimental values for the carbon dioxide solubility in eight pure electrolyte solvents for lithium ion batteries – such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), ?-butyrolactone (?BL), ethyl acetate (EA) and methyl propionate (MP) – are reported as a function of temperature from (283 to 353) K and atmospheric pressure. Based on experimental solubility data, the Henry’s law constant of the carbon dio...

  19. Study of secondary electron emission from thin carbon targets with swift charged particles: heavy ions, hydrogen ions

    International Nuclear Information System (INIS)

    The main subject of this work is the study of electron emission from the two surfaces of thin solid targets bombarded with swift charged particles. The slowing down of swift ions in matter is mainly due to inelastic interaction with target electrons (ionization, excitation): the energy transfer to target electrons is responsible for the secondary electron emission process. The phenomenological and theoretical descriptions of this phenomena are the subject of the first chapter. We focused on secondary electron emission induced by different kind of projectiles on thin carbon foils. In chapter two we describe hydrogen cluster induced electron emission measurement between 40 and 120 keV/proton. These projectiles, composed of several atoms, allowed us to study and highlight collective effects of the electron emission process. We extended our study of electron emission to molecular (H2+, H3+) and composite (H-, H0) projectiles at higher energies (<= 2 MeV): we have designed an experimental set-up devoted to electron emission statistics measurements which allowed us to study, among others things, the role of projectile electrons in secondary electron emission. This experiment is described in the third chapter. Finally, the fourth chapter describes new measurements of electron emission induced by energetic (13 MeV/u) and highly charged argon ion provided by the medium energy beam line (SME) of GANIL (Caen), which have been analyzed in the framework of a semi-empirical model of secondary electron emission. This set of experiments brings new results on composite projectile interaction with matter, and on the consequences of high energy deposition in solids. (author)

  20. Observations of energetic oxygen and carbon ions with charge states between 3 and 6 in the magnetosphere

    Science.gov (United States)

    Kremser, G.; Stuedemann, W.; Wilken, B.; Gloeckler, G.; Hamilton, D. C.

    1988-01-01

    Data obtained by the AMPTE/CCE charge-energy-mass spectrometer are used to study the average spatial distributions of oxygen and carbon ions with charge states between 3 and 6. The O(6+) and C(6+) ion fluxes are found to increase with the drift shell parameter L up to a constant level at L of not less than 7. It is suggested that the diurnal variations noted are related to the shape of the L profiles. The results support a model in which the solar wind origin O(6+) and C(6+) ions and the terrestrial origin O(+) and O(2+) ions are transported from the tail towards the earth. Charge exchange processes near the earth produce the oxygen and carbon ions with charge states between 3 and 5.

  1. Ambiguities in thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    On one hand, thermoluminescence dosimetry is one of most reliable, rugged and economical system of passive dosimetry but on the other hand there are several ambiguities, which need attention. The PTTL is a complex phenomenon and it is difficult to identify the source for the transfer of the charge carrier to repopulate the traps related to the glow peaks. For the photon energy dependence it is difficult to explain the change in the response for 662 keV gamma rays of 137Cs as compared to the response for 1.25 MeV gamma rays of 60Co. The increase in the response of a TLD with increasing heating rate poses another ambiguity and so is the case with the observations of the supra linearity of different glow peaks. To over come the ambiguities, efforts have to continue to enhance the understanding and to harmonize the protocol for reliable experimental data

  2. Neutron beam measurement dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Amaro, C.R. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-11-01

    This report describes animal dosimetry studies and phantom measurements. During 1994, 12 dogs were irradiated at BMRR as part of a 4 fraction dose tolerance study. The animals were first infused with BSH and irradiated daily for 4 consecutive days. BNL irradiated 2 beagles as part of their dose tolerance study using BPA fructose. In addition, a dog at WSU was irradiated at BMRR after an infusion of BPA fructose. During 1994, the INEL BNCT dosimetry team measured neutron flux and gamma dose profiles in two phantoms exposed to the epithermal neutron beam at the BMRR. These measurements were performed as a preparatory step to the commencement of human clinical trials in progress at the BMRR.

  3. 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.

  4. Quantitative imaging for clinical dosimetry

    Science.gov (United States)

    Bardiès, Manuel; Flux, Glenn; Lassmann, Michael; Monsieurs, Myriam; Savolainen, Sauli; Strand, Sven-Erik

    2006-12-01

    Patient-specific dosimetry in nuclear medicine is now a legal requirement in many countries throughout the EU for targeted radionuclide therapy (TRT) applications. In order to achieve that goal, an increased level of accuracy in dosimetry procedures is needed. Current research in nuclear medicine dosimetry should not only aim at developing new methods to assess the delivered radiation absorbed dose at the patient level, but also to ensure that the proposed methods can be put into practice in a sufficient number of institutions. A unified dosimetry methodology is required for making clinical outcome comparisons possible.

  5. Deposition of diamond like carbon films by using a single ion gun with varying beam source

    Institute of Scientific and Technical Information of China (English)

    JIANG Jin-qiu; Chen Zhu-ping

    2001-01-01

    Diamond like carbon films have been successfully deposited on the steel substrate, by using a single ion gun with varying beam source. The films may appear blue, yellow and transparent in color, which was found related to contaminants from the sample holder and could be avoided. The thickness of the films ranges from tens up to 200 nanometers, and the hardness is in the range 20 to 30 GPa. Raman analytical results reveal the films are in amorphous structure. The effects of different beam source on the films structure are further discussed.

  6. Hierarchically mesoporous CuO/carbon nanofiber coaxial shell-core nanowires for lithium ion batteries

    OpenAIRE

    Seok-Hwan Park; Wan-Jin Lee

    2015-01-01

    Hierarchically mesoporous CuO/carbon nanofiber coaxial shell-core nanowires (CuO/CNF) as anodes for lithium ion batteries were prepared by coating the Cu2(NO3)(OH)3 on the surface of conductive and elastic CNF via electrophoretic deposition (EPD), followed by thermal treatment in air. The CuO shell stacked with nanoparticles grows radially toward the CNF core, which forms hierarchically mesoporous three-dimensional (3D) coaxial shell-core structure with abundant inner spaces in nanoparticle-s...

  7. Carbonate Ion-Enriched Hot Spring Water Promotes Skin Wound Healing in Nude Rats

    OpenAIRE

    Jingyan Liang; Dedong Kang; Yingge Wang; Ying Yu; Jianglin Fan; En Takashi

    2015-01-01

    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 spee...

  8. 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)

  9. Equilibrium charge-state distributions of highly stripped ions in carbon foils

    International Nuclear Information System (INIS)

    Asymmetric equilibrium charge-state distributions observed for heavy ions (Z approx. >= 7) in carbon foils at high velocities (v > 3.6 x 108 Z0sup(.)45 cm s-1) are closely approximated by a simple statistical distribution: the reduced chi-squared model. The dependences of the mean charge and of the standard deviation of the charge on the projectile velocity are obtained by a previously-known and a newly-proposed relation, respectively. Finally charge-state fractions may be easily predicted using a simple formula depending only on the atomic number and on the velocity of the projectile. (orig.)

  10. Personnel radiation dosimetry

    International Nuclear Information System (INIS)

    The book contains the 21 technical papers presented at the Technical Committee Meeting to Elaborate Procedures and Data for the Intercomparison of Personnel Dosimeters organizaed by the IAEA on 22-26 April 1985. A separate abstract was prepared for each of these papers. A list of areas in which additional research and development work is needed and recommendations for an IAEA-sponsored intercomparison program on personnel dosimetry is also included

  11. INDIVIDUAL DOSIMETRY SERVICE

    CERN Multimedia

    1999-01-01

    Personnel in the distribution groups Aleph, Delphi, L3, Opal who also work for other experiments than at LEP, should contact the Individual Dosimetry ServiceWe inform all staff and users under regular dosimetric control that the dosimeters for the monitoring period JANUARY/FEBRUARY will be available from their usual dispatchers on Monday the third of January 2000.Please have your films changed:before the 12 January.The colour of the dosimeter valid in JANUARY/FEBRUARY is WHITE.

  12. INDIVIDUAL DOSIMETRY SERVICE

    CERN Multimedia

    2000-01-01

    Personnel in the distribution groups Aleph, Delphi, L3, Opal who also work for other experiments than at LEP, should contact the Individual Dosimetry Service.We inform all staff and users under regular dosimetric control that the dosimeters for the monitoring period MARCH/APRIL will be available from their usual dispatchers on the third of March 2000.Please have your films changed before the 13th of March.The colour of the dosimeter valid in MARCH/APRIL is BLUE.

  13. Personal radon daughter dosimetry

    International Nuclear Information System (INIS)

    The conventional means of radon daughter exposure estimatikn for uranium miners in Canada is by grab sampling and time weighting. Personal dosimetry is a possible alternative method with its own advantages and limitations. The author poses basic questions with regard to two methods of radon daughter detection, thermoluminescent chips and track-etch film. An historical review of previous and current research and development programs in Canada and in other countries is presented, as are brief results and conclusions of each dosimeter evaluation

  14. Heat generation of mechanically abused lithium-ion batteries modified by carbon black micro-particulates

    International Nuclear Information System (INIS)

    In the current study, we experimentally investigated the effects of carbon black micro-particulates (CBMP) on the temperature increase of lithium-ion battery coin cells subjected to nail penetration and blunt impact. The major difference between CBMP and regular carbon black additives is in particle size. The testing data showed that addition of 1 wt% of CBMP in the cathode and anode does not influence the cycle life, while can reduce the heat generation rate by nearly 50%, after the peak temperature is reached. Thermal treatment of the modified cells at 100 °C would further reduce the heat generate rate. The initial temperature increase rate, the maximum temperature, as well as the total energy dissipation are not affected. These findings shed light on thermal runaway mitigation of high-energy batteries. (paper)

  15. Carbon ion fragmentation effects on the nanometric level behind the Bragg peak depth

    International Nuclear Information System (INIS)

    In this study, fragmentation yields of carbon therapy beams are estimated using the Geant4 simulation toolkit version 9.5. Simulations are carried out in a step-by-step mode using the Geant4-DNA processes for each of the major contributing fragments. The energy of the initial beam is taken 400 MeV amu−1 as this is the highest energy, which is used for medical accelerators and this would show the integral role of secondary contributions in radiotherapy irradiations. The obtained results showed that 64% of the global dose deposition is initiated by carbon ions, while up to 36% is initiated by the produced fragments including all their isotopes. The energy deposition clustering yields of each of the simulated fragments are then estimated using the DBSCAN clustering algorithm and they are compared to the yields of the incident primary beam. (paper)

  16. Synthesis of Microspherical LiFePO4-Carbon Composites for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Maria-Magdalena Titirici

    2013-07-01

    Full Text Available This paper reports an “all in one” procedure to produce mesoporous, micro-spherical LiFePO4 composed of agglomerated crystalline nanoparticles. Each nanoparticle is individually coated with a thin glucose-derived carbon layer. The main advantage of the as-synthesized materials is their good performance at high charge-discharge rates. The nanoparticles and the mesoporosity guarantee a short bulk diffusion distance for both lithium ions and electrons, as well as additional active sites for the charge transfer reactions. At the same time, the thin interconnected carbon coating provides a conductive framework capable of delivering electrons to the nanostructured LiFePO4.

  17. Potential threshold of anode materials for foldable lithium-ion batteries featuring carbon nanotube current collectors

    Science.gov (United States)

    Wang, Qing Hui; Zhong, Sheng Wen; Hu, Jing Wei; Liu, Ting; Zhu, Xian Yan; Chen, Jing; Hong, Yin Yan; Wu, Zi Ping

    2016-04-01

    Flexible carbon nanotube macro-films (CMFs) are perfect current collectors for preparing foldable lithium-ion batteries (LIBs). However, selecting appropriate anodes for electrode is difficult because of the different potentials (vs. Li/Li+) of carbon nanotubes and traditional metallic current collector. This study demonstrated an additional reaction at potential below 0.9 V (vs. Li/Li+) caused by CMF, And Li+ will be constrained, which decreased capacity of anode/CMF electrode. Conversely, results changed when the anode potential exceeded 0.9 V (vs. Li/Li+) because Li+ passed the potential threshold, and the CMF retained its electrochemical inactivity. Consequently, the CMF-based foldable LIBs performed well. The potential threshold mechanism of anode is expected to provide new impetus to both academia and industry for exploring flexible or foldable LIBs.

  18. Transplantation of ES cells to Parkinson model rat irradiated with carbon ion beam

    International Nuclear Information System (INIS)

    The present study was designed to make a new Parkinson disease model using carbon ion beam. We irradiated right medial forebrain bundle of adult SD rats with charged carbon particles (290 MeV/nucleon, Mono peak, 150 Gy) and damaged right dopaminergic neurons pathway. To irradiate precisely, rats were set in the stereotactic frame with ear bars. Four weeks after the irradiation, behavioral test and in vitro autoradiography showed hemi-Parkinson model as well as 6-OHDA lesioned rats. Pathological examinations showed cell death, gliosis and inflammations at the irradiated area. However, no obvious alteration was observed at the surrounding normal tissue. These results indicated utility and validity of this method. (author)

  19. 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

  20. Dosimetry: an ARDENT topic

    CERN Multimedia

    CERN Bulletin

    2012-01-01

    The first annual ARDENT workshop took place in Vienna from 20 to 23 November. The workshop gathered together the Early-Stage Researchers (ESR) and their supervisors, plus other people involved from all the participating institutions.   “The meeting, which was organised with the local support of the Austrian Institute of Technology, was a nice opportunity for the ESRs to get together, meet each other, and present their research plans and some preliminary results of their work,” says Marco Silari, a member of CERN Radiation Protection Group and the scientist in charge of the programme. Two full days were devoted to a training course on radiation dosimetry, delivered by renowned experts. The workshop closed with a half-day visit to the MedAustron facility in Wiener Neustadt. ARDENT (Advanced Radiation Dosimetry European Network Training) is a Marie Curie ITN project funded under EU FP7 with €4 million. The project focuses on radiation dosimetry exploiting se...

  1. Optical properties and oxidation of carbonized and cross-linked structures formed in polycarbonate by plasma immersion ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Kosobrodova, E., E-mail: elenak@physics.usyd.edu.au [Department of Applied Plasma and Physics, School of Physics, University of Sydney, NSW 2006 (Australia); Kondyurin, A. [Department of Applied Plasma and Physics, School of Physics, University of Sydney, NSW 2006 (Australia); Chrzanowski, W. [Faculty of Pharmacy, University of Sydney, NSW 2006 (Australia); Department of Nanobiomedical Science and BK21 PLUS NBM Global Research, Center for Regenerative Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of); McCulloch, D.G. [School of Applied Sciences, RMIT University, Melbourne, Victoria 3001 (Australia); McKenzie, D.R.; Bilek, M.M.M. [Department of Applied Plasma and Physics, School of Physics, University of Sydney, NSW 2006 (Australia)

    2014-06-01

    Highlights: • Structure and properties of polycarbonate films spin-coated on silicon are studied. • The films have two thicknesses: thicker and thinner than a depth of ion penetration. • Effect of radio frequency plasma and plasma immersion ion implantation is compared. - Abstract: At ion fluences higher than 5 · 10{sup 15} ions/cm{sup 2}, plasma immersion ion implantation (PIII) of polycarbonate (PC) results in a formation of a carbonized surface layer. The thickness of this layer is close to the depth of ion penetration. A comparison of PIII treated, spin-coated PC films with pre-treatment thicknesses designed to match and exceed the carbonized layer thickness is employed to study the properties of the carbonised layer independently from the less modified underlying structure. At ion fluencies higher than 10{sup 16} ions/cm{sup 2}, the thinner PC film is completely transformed into an amorphous carbon-like material with no traces of the initial PC structure. The thicker films, however, incorporated two layers: a top carbonised layer and a cross-linked layer below. Compared to the two-layered PC film, the completely carbonized layer was found to have a much higher concentration of C=O bonds and much lower concentration of O–H bonds after exposure to atmospheric oxygen. The refractive index of the thicker PC films PIII treated with high ion fluencies is close to the refractive index of diamond-like carbon. Anomalous dispersion of the refractive index of the thicker PC films is observed after formation of the carbonised layer. The refractive index of the thinner PC film has normal dispersion at all ion fluences. At ion fluences of 2 · 10{sup 16} ions/cm{sup 2}, both PC films were found to have the same etching rate as polystyrene. Washing in dichloromethane had no effect on the carbonised layer but affected the underlying material in the case of the thicker PC films leading to a wrinkled structure up to ion fluences of 2 · 10{sup 16} ions/cm{sup 2}. At

  2. Influence of H2 reduction on lignin-based hard carbon performance in lithium ion batteries

    International Nuclear Information System (INIS)

    ABSTRACT: Lignin as a by-product of fuel alcohol industry is used to prepare hard carbon materials by acetone extraction, stabilization in N2 at 300 °C, carbonization in N2 and subsequent H2 reduction at 800 °C. The effect of H2 reduction after carbonization process on the performances of the prepared samples is systematically studied and a simple mechanism is proposed. Excitingly, it is demonstrated that the process of H2 reduction has a favorable influence on both structures and electrochemical performances of pyrolysis sample and an obvious improvement of capacity performance is obtained with reduction treatment. A first discharge/ charge capacity of 882.2/550.5 mA h g−1 (coulombic efficiency (CE) of 62.4%) is achieved at 0.1 C (1C = 372 mA g−1), and even after 200 cycles at 2 C a charge capacity of 228.8 mA h g−1 (about 92.8% retention ratio) remains and CE is above 99% during cycles for H2 reduced sample. The fabulous electrochemical performance could be attributed to high purity of acetone-extracted lignin, low surface oxygen-containing functional groups and relatively high graphitization degree of reduction sample. In a word, both the simple pyrolysis process and excellent electrochemical performance make lignin-based hard carbon a promising anode material for high-capacity and high-stability lithium ion batteries (LIBs)

  3. Thermoluminescence dosimetry of rare earth doped calcium aluminate phosphors

    Indian Academy of Sciences (India)

    K Madhukumar; K Rajendra Babu; K C Ajith Prasad; J James; T S Elias; V Padmanabhan; C M K Nair

    2006-04-01

    The thermoluminescence (TL) properties of calcium aluminate (CaAl2O4) doped with different rare earth ions have been studied and their suitability for radiation dosimetry applications is discussed. It is observed that monocalcium aluminate doped with cerium is a good dosimeter having linear response up to about 4 kGy of radiation doses. Dopant concentration of 0.25 mol% cerium gives maximum TL emission. The well-defined single peak observed at 295°C can be advantageously used for high temperature dosimetry applications.

  4. Thermal and electrochemical studies of carbons for Li-ion batteries. 2. Correlation of active sites and irreversible capacity loss

    Science.gov (United States)

    Tran, T.; Yebka, B.; Song, X.; Nazri, G.; Kinoshita, K.; Curtis, D.

    Thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) involving air oxidation of fluid coke, coal-tar pitch delayed coke and needle coke suggested that active sites are present which can be correlated to the crystallographic parameters, La and Lc, and the d(002) spacing. This finding was extended to determine the relationship between active sites on carbon and their role in catalyzing electrolyte decomposition leading to irreversible capacity loss (ICL) in Li-ion batteries. Electrochemical data from this study with graphitizable carbons and from published literature were analyzed to determine the relationship between the physical properties of carbon and the ICL during the first charge/discharge cycle. Based on this analysis, we conclude that the active surface area, and not the total BET surface area, has an influence on the ICL of carbons for Li-ion batteries. This conclusion suggests that the carbon surface structure plays a significant role in catalyzing electrolyte decomposition.

  5. Ion-Responsive Channels of Zwitterion-Carbon Nanotube Membrane for Rapid Water Permeation and Ultrahigh Mono-/Multivalent Ion Selectivity.

    Science.gov (United States)

    Liu, Tian-Yin; Yuan, Hao-Ge; Li, Qian; Tang, Yuan-Hui; Zhang, Qiang; Qian, Weizhong; Van der Bruggen, Bart; Wang, Xiaolin

    2015-07-28

    The rational combination of polymer matrix and nanostructured building blocks leads to the formation of composite membranes with unexpected capability of selectivity of monovalent electrolytes and water, which affords the feasibility to effeciently remove harmful ions and neutral molecules from the environment of concentrated salines. However, the multivalent ion rejection in salined water of routine nanocomposite membranes was less than 98% when ion strength is high, resulting in a poor ion selectivity far below the acceptable value. In this contribution, the ion-responsive membrane with zwitterion-carbon nanotube (ZCNT) entrances at the surface and nanochannels inside membrane has been proposed to obtain ultrahigh multivalent ion rejection. The mean effective pore diameter of ZCNT membrane was dedicated tuned from 1.24 to 0.54 nm with the rise in Na2SO4 concentration from 0 to 70 mol m(-3) as contrary to the conventional rejection drop in carbon nanotube (CNT) membrane. The ultrahigh selective permeabilities of monovalent anions against divalent anions of 93 and against glucose of 5.5 were obtained on ZCNT membrane, while such selectivities were only 20 and 1.6 for the pristine CNT membrane, respectively. The ZCNT membranes have potential applications in treatment of salined water with general NaCl concentration from 100 to 600 mol m(-3), which are widely applicable in desalination, food, and biological separation processes. PMID:26153719

  6. Biological dose representation for carbon-ion radiotherapy of unconventional fractionation

    CERN Document Server

    Kanematsu, Nobuyuki

    2016-01-01

    In carbon-ion radiotherapy, single-beam delivery each day in alternate directions has been commonly practiced for operational efficiency, taking advantage of the Bragg peak and the relative biological effectiveness (RBE) for uniform dose conformation to a tumor. The treatment plans are usually evaluated with total RBE-weighted dose, which is however deficient in relevance to the biological effect in the linear-quadratic model due to its quadratic-dose term, or the dose-fractionation effect. In this study, we reformulate the extrapolated response dose (ERD), or synonymously BED, which normalizes the dose-fractionation and cell-repopulation effects as well as the RBE of treating radiation, based on inactivation of a single model cell system and a typical treating radiation in carbon-ion RT. The ERD distribution virtually represents the biological effect of the treatment regardless of radiation modality or fractionation scheme. We applied the ERD formulation to simplistic model treatments and to a preclinical su...

  7. Transport of ions in mesoporous carbon electrodes during capacitive deionization of high-salinity solutions.

    Science.gov (United States)

    Sharma, K; Kim, Y-H; Gabitto, J; Mayes, R T; Yiacoumi, S; Bilheux, H Z; Walker, L M H; Dai, S; Tsouris, C

    2015-01-27

    Desalination of high-salinity solutions has been studied using a novel experimental technique and a theoretical model. Neutron imaging has been employed to visualize lithium ions in mesoporous carbon materials, which are used as electrodes in capacitive deionization (CDI) for water desalination. Experiments were conducted with a flow-through CDI cell designed for neutron imaging and with lithium-6 chloride ((6)LiCl) as the electrolyte. Sequences of neutron images have been obtained at a relatively high concentration of (6)LiCl solution to provide information on the transport of ions within the electrodes. A new model that computes the individual ionic concentration profiles inside mesoporous carbon electrodes has been used to simulate the CDI process. Modifications have also been introduced into the simulation model to calculate results at high electrolyte concentrations. Experimental data and simulation results provide insight into why CDI is not effective for desalination of high ionic-strength solutions. The combination of experimental information, obtained through neutron imaging, with the theoretical model will help in the design of CDI devices, which can improve the process for high ionic-strength solutions. PMID:25533167

  8. Porous Si spheres encapsulated in carbon shells with enhanced anodic performance in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui; Wu, Ping, E-mail: zjuwuping@njnu.edu.cn; Shi, Huimin; Lou, Feijian; Tang, Yawen; Zhou, Tongge; Zhou, Yiming, E-mail: zhouyiming@njnu.edu.cn; Lu, Tianhong

    2014-07-01

    Highlights: • In situ magnesiothermic reduction route for the formation of porous Si@C spheres. • Unique microstructural characteristics of both porous sphere and carbon matrix. • Enhanced anodic performance in term of cycling stability for lithium-ion batteries. - Abstract: A novel type of porous Si–C micro/nano-hybrids, i.e., porous Si spheres encapsulated in carbon shells (porous Si@C spheres), has been constructed through the pyrolysis of polyvinylidene fluoride (PVDF) and subsequent magnesiothermic reduction methodology by using SiO{sub 2} spheres as precursors. The as-synthesized porous Si@C spheres have been applied as anode materials for lithium-ion batteries (LIBs), and exhibit enhanced anodic performance in term of cycling stability compared with bare Si spheres. For example, the porous Si@C spheres are able to exhibit a high reversible capacity of 900.0 mA h g{sup −1} after 20 cycles at a current density of 0.05 C (1 C = 4200 mA g{sup −1}), which is much higher than that of bare Si spheres (430.7 mA h g{sup −1})

  9. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    International Nuclear Information System (INIS)

    Application of pulsed high negative voltage (∼10 μs pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron microscopy, and its structure characteristics are examined by XPS and laser Raman spectroscopy. Subsequent processing using acetylene or acetylene and Ar (20%) produced thin carbon layers that are confirmed to be graphite-dominated DLC. Also, this PSII method is employed in order to deposit the DLC layer on the inside surface of the PET bottle and to reduce oxygen permeation rate by 40%

  10. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    Science.gov (United States)

    Tanaka, T.; Yoshida, M.; Shinohara, M.; Takagi, T.

    2002-05-01

    Application of pulsed high negative voltage (~10 μs pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron microscopy, and its structure characteristics are examined by XPS and laser Raman spectroscopy. Subsequent processing using acetylene or acetylene and Ar (20%) produced thin carbon layers that are confirmed to be graphite-dominated DLC. Also, this PSII method is employed in order to deposit the DLC layer on the inside surface of the PET bottle and to reduce oxygen permeation rate by 40%.

  11. Monte Carlo simulations of prompt-gamma emission during carbon ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Le Foulher, F.; Bajard, M.; Chevallier, M.; Dauvergne, D.; Henriquet, P.; Ray, C.; Testa, E.; Testa, M. [Universite de Lyon 1, F-69003 Lyon (France); IN2P3/CNRS, UMR 5822, Institut de Physique Nucleaire de Lyon, F-69622 Villeurbanne (France); Freud, N.; Letang, J. M. [Laboratoire de Controles Non Destructifs Par Rayonnements Ionisants, INSA-Lyon, F-69621 Villeurbanne cedex (France); Karkar, S. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Plescak, R.; Schardt, D. [Gesellschaft fur Schwerionenforschung (GSI), D-64291 Darmstadt (Germany)

    2009-07-01

    Monte Carlo simulations based on the Geant4 tool-kit (version 9.1) were performed to study the emission of secondary prompt gamma-rays produced by nuclear reactions during carbon ion-beam therapy. These simulations were performed along with an experimental program and instrumentation developments which aim at designing a prompt gamma-ray device for real-time control of hadron therapy. The objective of the present study is twofold: first, to present the features of the prompt gamma radiation in the case of carbon ion irradiation; secondly, to simulate the experimental setup and to compare measured and simulated counting rates corresponding to various experiments. For each experiment, we found that simulations overestimate prompt gamma-ray detection yields by a factor of 12. Uncertainties in fragmentation cross sections and binary cascade model cannot explain such discrepancies. The so-called 'photon evaporation' model is therefore questionable and its modification is currently in progress. (authors)

  12. Particles that fight cancer: the use of protons and carbon ions in cancer therapy

    CERN Document Server

    CERN. Geneva

    2014-01-01

    Particles that fight cancer: the use of protons and carbon ions in cancer therapy Cancer is a major societal issue. A key challenge for cancer therapy is the complex and multifaceted nature of the disease, which calls for personalised treatment. Radiotherapy has been used to treat tumours for more than a century, and is still a staple in oncology: today, 50 % of cancer patients receive radiotherapy, half of them with curative intent. Hadrontherapy is one of the most technologically advanced methods of delivering radiation dose to the tumour while protecting surrounding healthy tissues. In addition, hadrontherapy can reach otherwise difficult to access deep-seated tumours and can be used for radio resistant tumours as in hypoxia. This year marks 60 years since the first patient was treated with protons in the US and 20 years since the use of carbon ions in Japan. Join us in learning about the journey of particle therapy in Japan and Europe, its challenges, clinical results and future prospects. Thursday 2...

  13. Lithium-ion capacitors with 2D Nb2CTx (MXene) - carbon nanotube electrodes

    Science.gov (United States)

    Byeon, Ayeong; Glushenkov, Alexey M.; Anasori, Babak; Urbankowski, Patrick; Li, Jingwen; Byles, Bryan W.; Blake, Brian; Van Aken, Katherine L.; Kota, Sankalp; Pomerantseva, Ekaterina; Lee, Jae W.; Chen, Ying; Gogotsi, Yury

    2016-09-01

    There is a growing interest to hybrid energy storage devices, such as lithium-ion capacitors, in which battery-type electrodes are combined with capacitor-type ones. It is anticipated that the energy density (either gravimetric or volumetric) of lithium-ion capacitors is improved if pseudocapacitive or fast insertion materials are used instead of conventional activated carbon (AC) in the capacitor-type electrode. MXenes, a new family of two-dimensional transition metal carbides, demonstrate metallic conductivity and fast charge-discharge behavior that make them suitable for this application. In this study, we move beyond single electrodes, half-cell studies and demonstrate three types of hybrid cells using Nb2CTx-carbon nanotube (CNT) films. It is shown that lithiated graphite/Nb2CTx-CNT, Nb2CTx-CNT/LiFePO4 and lithiated Nb2CTx-CNT/Nb2CTx-CNT cells are all able to operate within 3 V voltage windows and deliver capacities of 43, 24 and 36 mAh/g (per total weight of two electrodes), respectively. Moreover, the polarity of the electrodes can be reversed in the symmetric Nb2CTx-CNT cells from providing a positive potential between 0 and 3 V to a negative one from -3 to 0 V. It is shown that the volumetric energy density (50-70 Wh/L) of our first-generation devices with MXene electrodes exceeds that of a lithium titanate/AC capacitor.

  14. Water equivalent thickness values of materials used in beams of protons, helium, carbon and iron ions.

    Science.gov (United States)

    Zhang, Rui; Taddei, Phillip J; Fitzek, Markus M; Newhauser, Wayne D

    2010-05-01

    Heavy charged particle beam radiotherapy for cancer is of increasing interest because it delivers a highly conformal radiation dose to the target volume. Accurate knowledge of the range of a heavy charged particle beam after it penetrates a patient's body or other materials in the beam line is very important and is usually stated in terms of the water equivalent thickness (WET). However, methods of calculating WET for heavy charged particle beams are lacking. Our objective was to test several simple analytical formulas previously developed for proton beams for their ability to calculate WET values for materials exposed to beams of protons, helium, carbon and iron ions. Experimentally measured heavy charged particle beam ranges and WET values from an iterative numerical method were compared with the WET values calculated by the analytical formulas. In most cases, the deviations were within 1 mm. We conclude that the analytical formulas originally developed for proton beams can also be used to calculate WET values for helium, carbon and iron ion beams with good accuracy.

  15. Removal characteristics of Cd(II) ions from aqueous solution on ordered mesoporous carbon

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Linhang; Zhao, Haibo; Yan, Lu; Wang, Guowei; Mao, Yulin; Wang, Xin; Liu, Kai; Liu, Xiufang; Zhao, Qian; Jiang, Tingshun [Jiangsu University, Jiangsu (China)

    2015-10-15

    Ordered mesoporous carbon (CMK-3) was synthesized using SBA-15 mesoporous molecular sieve as a template and sucrose as carbon source. The materials were characterized by XRD, TEM and N2 physical adsorption technique. The resulting CMK-3 was used as adsorbent to remove Cd(II) ions from aqueous solution. The effect of pH, contact time and temperature on adsorption process was investigated in batch experiments. The results showed that the removal percentage could reach ca. 90% at the conditions of initial Cd(II) ions concentration of 20 mg/L, dose of 20mg, pH 6.5, contact time of 3h and 293K. Langmuir and Freundlich models were employed to describe the adsorption equilibrium. The kinetics data were described by the pseudo-first-order and pseudo-second-order models, respectively. The adsorption isotherm was well fitted to the Langmuir model, and the adsorption process was well described by the pseudo-second-order kinetic model.

  16. Copper Nanoparticle-Incorporated Carbon Fibers as Free-Standing Anodes for Lithium-Ion Batteries

    Science.gov (United States)

    Han, Pan; Yuan, Tao; Yao, Long; Han, Zhuo; Yang, Junhe; Zheng, Shiyou

    2016-03-01

    Copper-incorporated carbon fibers (Cu/CF) as free-standing anodes for lithium-ion batteries are prepared by electrospinning technique following with calcination at 600, 700, and 800 °C. The structural properties of materials are characterized by X-ray diffraction (XRD), Raman, thermogravimetry (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectrometry (EDS). It is found that the Cu/CF composites have smooth, regular, and long fibrous morphologies with Cu nanoparticles uniformly dispersed in the carbon fibers. As free-standing anodes, the unique structural Cu/CF composites show stable and high reversible capacities, together with remarkable rate and cycling capabilities in Li-ion batteries. The Cu/CF calcined at 800 °C (Cu/CF-800) has the highest charge/discharge capacities, long-term stable cycling performance, and excellent rate performance; for instance, the Cu/CF-800 anode shows reversible charge/discharge capacities of around 800 mAh g-1 at a current density of 100 mA g-1 with stable cycling performance for more than 250 cycles; even when the current density increases to 2 A g-1, the Cu/CF-800 anode can still deliver a capacity of 300 mAh g-1. This excellent electrochemical performance is attributed to the special 1D structure of Cu/CF composites, the enhanced electrical conductivity, and more Li+ active positions by Cu nanoinclusion.

  17. Water equivalent thickness values of materials used in beams of protons, helium, carbon and iron ions.

    Science.gov (United States)

    Zhang, Rui; Taddei, Phillip J; Fitzek, Markus M; Newhauser, Wayne D

    2010-05-01

    Heavy charged particle beam radiotherapy for cancer is of increasing interest because it delivers a highly conformal radiation dose to the target volume. Accurate knowledge of the range of a heavy charged particle beam after it penetrates a patient's body or other materials in the beam line is very important and is usually stated in terms of the water equivalent thickness (WET). However, methods of calculating WET for heavy charged particle beams are lacking. Our objective was to test several simple analytical formulas previously developed for proton beams for their ability to calculate WET values for materials exposed to beams of protons, helium, carbon and iron ions. Experimentally measured heavy charged particle beam ranges and WET values from an iterative numerical method were compared with the WET values calculated by the analytical formulas. In most cases, the deviations were within 1 mm. We conclude that the analytical formulas originally developed for proton beams can also be used to calculate WET values for helium, carbon and iron ion beams with good accuracy. PMID:20371908

  18. Evaluation of KTJT-1, an early-maturity of sweet sorghum acquired by carbon ions irradiation

    International Nuclear Information System (INIS)

    Sweet sorghum has the potential of becoming a useful energy crop. An early-maturity mutant of sweet sorghum, KFJT-1, was obtained by carbon ions irradiation of KFJT-CK, a wild plant. In this paper, we evaluate the mutant from the length and fresh weight of radicle and leaves after seed germination, the growth rate at the elongation stage, and the internodal parameters under field trail condition. The results showed that the seedling growth of KFJT-1 was inhibited by carbon ions irradiation, and the leaf length, the fresh weight of radicle and leaves from KFJT-1 decreased by 15.32%, 76.27%, and 27.08% than those of KFJT-CK, respectively. However, the growth rate of KFJT-1 on July 12, July 27 and August 1 increased by 16.19%, 59.28% and 26.87%, respectively, compared with the KFJT-CK. The stalk diameter, total biomass yield and sugar content of KFJT-1 was higher than those of KFJT-CK, despite that the plant height of KFJT-1 was significantly less than KFJT-CK (P<0.05). In addition, KFJT-1 differed from KFJT-CK in the internodal length, weight and sugar content. In conclusion, the early-maturity mutant of KFJT-1 will be a promising variety for sweet sorghum industrialization in Gansu province, China. (authors)

  19. Influence of 400 keV carbon ion implantation on structural, optical and electrical properties of PMMA

    International Nuclear Information System (INIS)

    Ion implantation is a useful technique to modify surface properties of polymers without altering their bulk properties. The objective of this work is to explore the 400 keV C+ ion implantation effects on PMMA at different fluences ranging from 5 × 1013 to 5 × 1015 ions/cm2. The surface topographical examination of irradiated samples has been performed using Atomic Force Microscope (AFM). The structural and chemical modifications in implanted PMMA are examined by Raman and Fourier Infrared Spectroscopy (FTIR) respectively. The effects of carbon ion implantation on optical properties of PMMA are investigated by UV–Visible spectroscopy. The modifications in electrical conductivity have been measured using a four point probe technique. AFM images reveal a decrease in surface roughness of PMMA with an increase in ion fluence from 5 × 1014 to 5 × 1015 ions/cm2. The existence of amorphization and sp2-carbon clusterization has been confirmed by Raman and FTIR spectroscopic analysis. The UV–Visible data shows a prominent red shift in absorption edge as a function of ion fluence. This shift displays a continuous reduction in optical band gap (from 3.13 to 0.66 eV) due to formation of carbon clusters. Moreover, size of carbon clusters and photoconductivity are found to increase with increasing ion fluence. The ion-induced carbonaceous clusters are believed to be responsible for an increase in electrical conductivity of PMMA from (2.14 ± 0.06) × 10−10 (Ω-cm)−1 (pristine) to (0.32 ± 0.01) × 10−5 (Ω-cm)−1 (irradiated sample)

  20. The anode performance of the hard carbon for the lithium ion battery derived from the oxygen-containing aromatic precursors

    Science.gov (United States)

    Fujimoto, Hiroyuki; Tokumitsu, Katsuhisa; Mabuchi, Akihiro; Chinnasamy, Natarajan; Kasuh, Takahiro

    The hard carbon is attractive for the Li ion secondary battery because of its higher capacity than the theoretical value of 372 Ah kg -1 based on the composition of stage 1 Li-intercalated graphite, LiC 6. However, the structure of hard carbon as an anode has not been optimized and the reaction mechanism also has not been clarified in detail. In the present study, the structure of hard carbon derived from oxygen-containing coal tar pitch was investigated by X-ray diffraction, small angle scattering and density measurement, and the relationship between the structure of hard carbon and its anode performance was discussed.

  1. Active raster scanning with carbon ions. Reirradiation in patients with recurrent skull base chordomas and chondrosarcomas

    Energy Technology Data Exchange (ETDEWEB)

    Uhl, Matthias; Welzel, Thomas; Oelmann, Jan; Habl, Gregor; Hauswald, Henrik; Jensen, Alexandra; Debus, Juergen; Herfarth, Klaus [University of Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Ellerbrock, Malte [Heidelberg Ion Therapy Center (HIT), Heidelberg (Germany)

    2014-07-15

    To evaluate the safety and efficacy of reirradiation with carbon ions in patients with relapse of skull base chordoma and chondrosarcoma. Reirradiation with carbon ions was performed on 25 patients with locally recurrent skull base chordoma (n = 20) or chondrosarcoma (n = 5). The median time between the last radiation exposure and the reirradiation with carbon ions was 7 years. In the past, 23 patients had been irradiated once, two patients twice. Reirradiation was delivered using the active raster scanning method. The total median dose was 51.0 GyE carbon ions in a weekly regimen of five to six fractions of 3 GyE. Local progression-free survival (LPFS) was evaluated using the Kaplan-Meier method; toxicity was evaluated using the NCI Common Terminology Criteria for Adverse Events (CTCAE v.4.03). The treatment could be finished in all patients without interruption. In 80 % of patients, symptom control was achieved after therapy. The 2-year-LPFS probability was 79.3 %. A PTV volume of < 100 ml or a total dose of > 51 GyE was associated with a superior local control rate. The therapy was associated with low acute toxicity. One patient developed grade 2 mucositis during therapy. Furthermore, 12 % of patients had tympanic effusion with mild hypacusis (grade 2), while 20 % developed an asymptomatic temporal lobe reaction after treatment (grade 1). Only one patient showed a grade 3 osteoradionecrosis. Reirradiation with carbon ions is a safe and effective method in patients with relapsed chordoma and chondrosarcoma of the skull base. (orig.) [German] Evaluierung der Sicherheit und Wirksamkeit einer Re-Bestrahlung mittels Kohlenstoffionen bei Patienten mit Lokalrezidiv eines Chordoms und Chondrosarkoms der Schaedelbasis. Bei 25 Patienten mit einem Lokalrezidiv eines Chordoms (n = 20) oder Chondrosarkoms (n = 5) der Schaedelbasis erfolgte eine Re-Bestrahlung mittels Kohlenstoffionen. Die mediane Zeit zwischen letzter Bestrahlung und Re-Bestrahlung mit Kohlenstoffionen

  2. Effects of carbon ion beam irradiation on the shoot regeneration from in vitro axillary bud explants of the Impatiens hawkeri

    Science.gov (United States)

    Zhou, Libin; Zhou, Libin; Li, Wenjian; Li, Ping; Dong, Xicun; Qu, Ying; Ma, Shuang; Li, Qiang

    Accelerated ion beams is an excellent mutagen in plant breeding which can induce higher mutation frequencies and wider mutation spectrum than those of low linear energy transfer (LET) irradiations, such as X-rays (Okamura et al. 2003, Yamaguchi et al. 2003). Mutation breeding operation of two Saintpaulia ionahta cultivars using the method combining plant tissue culture technique and carbon ion beam irradiations were set out at Institute of Modern Physics from 2005 (Zhou et al. 2006). The effects of 960 MeV carbon ion beam and 8 MeV X-ray irradiations on regenerated shoots of Impatiens hawkeri from another kind of explants named in vitro axillary buds explants were studied recently. The biology endpoints in this study included relative number of roots (RNR), relative length of roots (RLR), relative height of shoots (RHS), relative number of nodes (RNN), survival fraction (SF) and morphology changes in the regenerated shoots. The experimental results showed that carbon ion beams inhibited the root and stem developments of axillary bud explants more severely than X-rays did. And the 50% lethal dose (LD50 ) is about 23.3 Gy for the carbon ion beam and 49.1 Gy for the X-rays, respectively. Relative biological effectiveness (RBE) of Impatiens hawkeri with respect to X-rays according to 50% SF was about two. Secondly, the percentage of shoots regenerated with malformed shoots including curliness, carnification, nicks in all Impatiens hawkeri axillary bud explants irradiated with carbon ion beam at 20 Gy accounted for 55.6%, while the highest number for the 40 Gy X-ray irradiation was 40%. Last, many regenerated shoots whose vascular bundle fused together were obtained only from explants irradiated with carbon ion beams. Based on the results above, it can be concluded that the effect of mutation induction by carbon ion beam irradiation on the axillary explants of Impatiens hawkeri is better than that by X-ray irradiation; and the optimal mutagenic dose varies from 20 Gy

  3. Performances of a lithium-carbon ``lithium ion``battery for electric powered vehicle; Performances d`un accumulateur au lithium-carbone ``Lithium Ion`` pour vehicule electrique

    Energy Technology Data Exchange (ETDEWEB)

    Broussely, M.; Planchat, J.P.; Rigobert, G.; Virey, D.; Sarre, G. [SAFT, Advanced and Industrial Battery Group, 86 - Poitiers (France)

    1996-12-31

    The lithium battery, also called `lithium-carbon` or `lithium ion`, is today the most promising candidate that can reach the expected minimum traction performances of electric powered vehicles. Thanks to a more than 20 years experience on lithium generators and to a specific research program on lithium batteries, the SAFT company has developed a 100 Ah electrochemical system, and full-scale prototypes have been manufactured for this application. These prototypes use the Li{sub x}NiO{sub 2} lithiated graphite electrochemical pair and were tested in terms of their electrical performances. Energy characteristics of 125 Wh/kg and 265 Wh/dm{sup 3} could be obtained. The possibility of supplying a power greater than 200 W/kg, even at low temperature (-10 deg. C) has been demonstrated with these elements. A full battery set of about 20 kWh was built and its evaluation is in progress. It comprises the electronic control systems for the optimum power management during charge and output. (J.S.) 9 refs.

  4. Residual chromatin breaks as biodosimetry for cell killing by carbon ions

    Science.gov (United States)

    Suzuki, M.; Kase, Y.; Nakano, T.; Kanai, T.; Ando, K.

    1998-11-01

    We have studied the relationship between cell killing and the induction of residual chromatin breaks on various human cell lines and primary cultured cells obtained by biopsy from patients irradiated with either X-rays or heavy-ion beams to identify potential bio-marker of radiosensitivity for radiation-induced cell killing. The carbon-ion beams were accelerated with the Heavy Ion Medical Accelerator in Chiba (HIMAC). Six primary cultures obtained by biopsy from 6 patients with carcinoma of the cervix were irradiated with two different mono-LET beams (LET = 13 keV/μm, 76 keV/μm) and 200kV X rays. Residual chromatin breaks were measured by counting the number of non-rejoining chromatin fragments detected by the premature chromosome condensation (PCC) technique after a 24 hour post-irradiation incubation period. The induction rate of residual chromatin breaks per cell per Gy was the highest for 76 keV/μm beams on all of the cells. Our results indicated that cell which was more sensitive to the cell killing was similarly more susceptible to induction of residual chromatin breaks. Furthermore there is a good correlation between these two end points in various cell lines and primary cultured cells. This suggests that the detection of residual chromatin breaks by the PCC technique may be useful as a predictive assay of tumor response to cancer radiotherapy.

  5. Radiolysis and sputtering of carbon dioxide ice induced by swift Ti, Ni, and Xe ions

    Science.gov (United States)

    Mejía, C.; Bender, M.; Severin, D.; Trautmann, C.; Boduch, Ph.; Bordalo, V.; Domaracka, A.; Lv, X. Y.; Martinez, R.; Rothard, H.

    2015-12-01

    Solid carbon dioxide (CO2) is found in several bodies of the solar system, the interstellar medium (ISM) and young stellar objects, where it is exposed to cosmic and stellar wind radiation. Here, the chemical and physical modifications induced by heavy ion irradiation of pure solid CO2 at low temperature (T = 15-30 K) are analyzed. The experiments were performed with Ti (550 MeV) and Xe (630 MeV) ions at the UNILAC of GSI/Darmstadt and with Ni ions (46 and 52 MeV) at IRRSUD of GANIL/Caen. The evolution of the thin CO2 ice films (deposited on a CsI window) was monitored by mid-infrared absorption spectroscopy (FTIR). The dissociation rate of CO2, determined from the fluence dependence of the IR absorption peak intensity, is found to be proportional to the electronic stopping power Se. We also confirm that the sputtering yield shows a quadric increase with electronic stopping power. Furthermore, the production rates of daughter molecules such as CO, CO3 and O3 were found to be linear in Se.

  6. Microarray Analysis of Human Liver Cells irradiated by 80MeV/u Carbon Ions

    Science.gov (United States)

    Wang, Xiao; Tian, Xiaoling; Kong, Fuquan; Li, Qiang; Jin, Xiaodong; Dai, Zhongying; Zhang, Hong; Yang, Mingjian; Zhao, Kui

    Objective Biological effect of heavy ion beam has the important significance for cancer therapy and space exploring owing its high LET and RBE, low OER, especially forming Bragg spike at the end of the tracks of charged particles. More serious damage for cells are induced by heavy ions and difficult repair than other irradiation such as X-ray and ν-ray . To explore the molecular mechanism of biological effect caused by heavy ionizing radiation (HIR) and to construct the gene expression profile database of HIR-induced human liver cells L02 by microarray analysis. Methods In this study, L02 cells were irradiated by 80MeV/u carbon ions at 5 Gy delivered by HIRFL (Heavy Ion Research Facility in Lanzhou) at room temperature. Total RNAs of cells incubated 6 hours and 24hours after irradiation were extracted with Trizol. Unirradiated cells were used as a control. RNAs were transcripted into cDNA by reverse transcription and labelled with cy5-dCTP and cy3-dCTP respectively. A human genome oligonucleotide set consisting of 5 amino acid-modified 70-mer probes and representing 21,329 well-characterized Homo sapiens genes was selected for microarray analysis and printed on amino-silaned glass slides. Arrays were fabricated using an OmniGrid microarrayer. Only genes whose alteration tendency was consistent in both microarrays were selected as differentially expressed genes. The Affymetrix's short oligonucleotide (25-mer) HG U133A 2.0 array analyses were performed per the manufacturer's instructions. Results Of the 21,329 genes tested, 37 genes showed changes in expression level with ratio higher than 2.0 and lower than 0.5 at 6hrs after irradiation. There were 19 genes showing up-regulation in radiated L02 cells, whereas 18 genes showing down-regulation; At 24hrs after irradiation, 269 genes showed changes in expression level with ratio higher than 2.0 and lower than 0.5. There were 67 genes showing up-regulation in radiated L02 cells, whereas 202 genes showing down

  7. Beam commissioning 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.

    2016-10-01

    A superconducting rotating-gantry for carbon-ion radiotherapy was developed. This isocentric gantry can transport carbon ions having kinetic energies of between E=430 and 48 MeV/u to an isocenter over an angle of ±180°, and is further capable of performing three-dimensional raster-scanning irradiation. Construction of the entire rotating-gantry system was completed by the end of September 2015. Prior to beam commissioning, phase-space distributions of extracted carbon beams from the synchrotron were deduced by using an empirical method. In this method, phase-space distributions at the extraction channel of the synchrotron were modeled with 8 parameters, and the best parameters were determined so as to minimize a difference between the calculated and measured beam profiles by using a simplex method. Based on the phase-space distributions, beam optics through the beam-transport lines as well as the rotating gantry were designed. Since horizontal and vertical beam emittances, as extracted slowly from the synchrotron, generally differ with each other, a horizontal-vertical beam coupling would occur when the gantry rotates. Thus, the size and shape of beam spots at the isocenter should vary depending on the gantry angle. To compensate for the difference in the emittances, we employed a method to utilize multiple Coulomb scattering of the beam particles by a thin scatterer. Having compensated for the emittances and designed beam optics through the rotating gantry, beam commissioning over various combinations of gantry angles and beam energies was performed. By finely tuning the superconducting quadrupoles of the rotating gantry, we could successfully obtain the designed beam quality, which satisfies the requirements of scanning irradiation.

  8. Yields of positron and positron emitting nuclei for proton and carbon ion radiation therapy: a simulation study with GEANT4.

    Science.gov (United States)

    Lau, Andy; Chen, Yong; Ahmad, Salahuddin

    2012-01-01

    A Monte Carlo application is developed to investigate the yields of positron-emitting nuclei (PEN) used for proton and carbon ion range verification techniques using the GEANT4 Toolkit. A base physics list was constructed and used to simulate incident proton and carbon ions onto a PMMA or water phantom using pencil like beams. In each simulation the total yields of PEN are counted and both the PEN and their associated positron depth-distributions were recorded and compared to the incident radiation's Bragg Peak. Alterations to the physics lists are then performed to investigate the PEN yields dependence on the choice of physics list. In our study, we conclude that the yields of PEN can be estimated using the physics list presented here for range verification of incident proton and carbon ions.

  9. Mixed ion-exchanger chemically modified carbon paste ion-selective electrodes for determination of triprolidine hydrochloride

    Directory of Open Access Journals (Sweden)

    Yousry M. Issa

    2010-01-01

    Full Text Available Triprolidine hydrochloride (TpCl ion-selective carbon paste electrodes were constructed using Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA as ion-exchangers. The two electrodes revealed Nernstian responses with slopes of 58.4 and 58.1 mV decade−1 at 25 °C in the ranges 6 × 10−6–1 × 10−2 and 2 × 10−5–1 × 10−2 M for Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA, respectively. The potentials of these electrodes were independent of pH in the ranges of 2.5–7.0 and 4.5–7.0, and detection limits were 6 × 10−6 and 1 × 10−5 M for Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA, respectively. The electrodes showed a very good selectivity for TpCl with respect to a large number of inorganic cations and compounds. The standard addition, potentiometric titration methods and FIA were applied to the determination of TpCl in pure solutions and pharmaceutical preparations. The results obtained were in close agreement with those found by the official method. The mean recovery values were 100.91% and 97.92% with low coefficient of variation values of 0.94%, and 0.56% in pure solutions, 99.82% and 98.53% with coefficient of variation values of 2.20%, and 0.73% for Actifed tablet and Actifed syrup, respectively, using the Tp-TPB/Tp-CoN electrode, and 98.85%, and 99.18% with coefficient of variation values of 0.48% and 0.85% for Actifed tablet and Actifed syrup, respectively, using the Tp-TPB/Tp-PTA electrode.

  10. Characterization of silicates and calcium carbonates applied to high-dose dosimetry; Caracterizacao de silicatos e carbonatos de calcio aplicados a dosimetria de doses altas

    Energy Technology Data Exchange (ETDEWEB)

    Vila, Gustavo Barreto

    2012-07-01

    The predominant isomorphous form in the biominerals studied in this work (oyster shell, coral, mother of pearl and shell) was aragonite. The appearance of the calcite phase occurred at 500 deg C at a heating rate of 10 deg {sup C}/s for all samples except for the coral sample, which was 400 deg C, independent of the heating rate. The most abundant element in the biominerals samples was Ca in the CaO form, and in the silicates (tremolite, diopside and rhodonite) Si in the SiO form. The most common trace element observed in the biominerals samples was Fe. The analyses of electron paramagnetic resonance showed lines of Mn{sup 2+} in the coral and mother-of-pearl samples before irradiation. In the case of the irradiated samples, the defects found were CO{sub 2}{sup -}, CO{sub 3}{sup 3-}, CO{sub 3}{sup -} and SO{sub 2}{sup -}, in the g range between 2.0010 and 2.0062. In the analyses by optical absorption of biominerals, transitions due to the presence of Mn in the samples were found. A thermoluminescent (TL) peak at approximately 140 deg C was found for the biominerals and at 180 deg C for silicates, which intensity depends directly on the dose. For samples exposed to different types of radiation, the TL peak occurred at lower temperatures. From the dose-response curves obtained for these materials, it was possible to determine a linear range for which their application in high dose dosimetry becomes possible. Taking into account the radiation type, among biominerals and silicates, the lowest detectable dose (40mGy) to gamma radiation was achieved for oyster shell samples using the measuring technique of optically stimulated luminescence (OSL). Using beta radiation, for diopside and tremolite samples the lowest detectable dose of 60mGy was obtained. For all samples, using the TL, OSL and thermally stimulated exoelectron emission (TSEE) techniques in alpha, beta and gamma radiation beans a good response reproducibility was obtained. Therefore, the samples characterized

  11. Carbon Nanotubes Act as Conductive Additives in the cathode of Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    Wang Guoping; Zhou Gumin; Qu MeiZhen; Wang Guixing; Wang Yunshi; Zhong Hong; Yu Zuolong

    2004-01-01

    The layered compounds LiCoO2, LiNiO2 and spinel compound LiMn2O4 have served as very effective cathode active materials in lithium ion rechargeable batteries. Generally, their high conductive resistance easily results in a serious polarization and poor utilization of active materials.In order to make full use of the active materials and increase the capacity, the charge-discharge rate and the cycle life of lithium ion batteries, conductive additives are often added into the above cathode materials to form a conductive network. Carbon materials, such as carbon black, graphite powders and chemical vapor deposit carbon fibers have been widely used as conductive additives owing to their high electrical conductivity and chemical inertness. To effectively utilize the active materials, the contents of these carbon additives in the cathode often reach up to 10~20wt%. This leads to a great need for binder, for example, 10wt% or more. It follows therefore a considerable increase in volume of the lithium batteries and lower energy density because of the large amount of carbon additives and binder in the cathode.By substituting carbon nanotubes (CNTs) for carbon black, graphite powders or chemical vapor deposit carbon fibers, much conductive additives and binder are saved, and the cathode with only 3~5wt% of conductive additives CNTs shows excellent rate capacity. At the discharge rate 0.5C,2.0C and 3.0C, the LiCoO2 cathode with CNTs exhibits discharge capacity up to 134mAh/g, 126 and 120mAh/g, respectively. The explanation is given as follows. Firstly, their microstructure and graphitic crystallinity are very important for electron transport. CNTs employed in the experiments comprise an array of complete graphite sheets seamlessly wrapped into cylindrical tubes which are concentrically nested like the rings of a tree trunk. Thus, the process of -electrons transport occurs in graphite sheet in super-conjugative manner when they move from one end to the other end in CNTs

  12. Core-shell amorphous silicon-carbon nanoparticles for high performance anodes in lithium ion batteries

    Science.gov (United States)

    Sourice, Julien; Bordes, Arnaud; Boulineau, Adrien; Alper, John P.; Franger, Sylvain; Quinsac, Axelle; Habert, Aurélie; Leconte, Yann; De Vito, Eric; Porcher, Willy; Reynaud, Cécile; Herlin-Boime, Nathalie; Haon, Cédric

    2016-10-01

    Core-shell silicon-carbon nanoparticles are attractive candidates as active material to increase the capacity of Li-ion batteries while mitigating the detrimental effects of volume expansion upon lithiation. However crystalline silicon suffers from amorphization upon the first charge/discharge cycle and improved stability is expected in starting with amorphous silicon. Here we report the synthesis, in a single-step process, of amorphous silicon nanoparticles coated with a carbon shell (a-Si@C), via a two-stage laser pyrolysis where decomposition of silane and ethylene are conducted in two successive reaction zones. Control of experimental conditions mitigates silicon core crystallization as well as formation of silicon carbide. Auger electron spectroscopy and scanning transmission electron microscopy show a carbon shell about 1 nm in thickness, which prevents detrimental oxidation of the a-Si cores. Cyclic voltammetry demonstrates that the core-shell composite reaches its maximal lithiation during the first sweep, thanks to its amorphous core. After 500 charge/discharge cycles, it retains a capacity of 1250 mAh.g-1 at a C/5 rate and 800 mAh.g-1 at 2C, with an outstanding coulombic efficiency of 99.95%. Moreover, post-mortem observations show an electrode volume expansion of less than 20% and preservation of the nanostructuration.

  13. Enhancement of Electrochemical Stability about Silicon/Carbon Composite Anode Materials for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Wei Xiao

    2015-01-01

    Full Text Available Silicon/carbon (Si/C composite anode materials are successfully synthesized by mechanical ball milling followed by pyrolysis method. The structure and morphology of the composite are characterized by X-ray diffraction and scanning electron microscopy and transmission electron microscope, respectively. The results show that the composite is composed of Si, flake graphite, and phenolic resin-pyrolyzed carbon, and Si and flake graphite are enwrapped by phenolic resin-pyrolyzed carbon, which can provide not only a good buffering matrix but also a conductive network. The Si/C composite also shows good electrochemical stability, in which the composite anode material exhibits a high initial charge capacity of 805.3 mAh g−1 at 100 mA g−1 and it can still deliver a high charge capacity of 791.7 mAh g−1 when the current density increases to 500 mA g−1. The results indicate that it could be used as a promising anode material for lithium ion batteries.

  14. Dual-carbon enhanced silicon-based composite as superior anode material for lithium ion batteries

    Science.gov (United States)

    Wang, Jie; Liu, Dai-Huo; Wang, Ying-Ying; Hou, Bao-Hua; Zhang, Jing-Ping; Wang, Rong-Shun; Wu, Xing-Long

    2016-03-01

    Dual-carbon enhanced Si-based composite (Si/C/G) has been prepared via employing the widely distributed, low-cost and environmentally friendly Diatomite mineral as silicon raw material. The preparation processes are very simple, non-toxic and easy to scale up. Electrochemical tests as anode material for lithium ion batteries (LIBs) demonstrate that this Si/C/G composite exhibits much improved Li-storage properties in terms of superior high-rate capabilities and excellent cycle stability compared to the pristine Si material as well as both single-carbon modified composites. Specifically for the Si/C/G composite, it can still deliver a high specific capacity of about 470 mAh g-1 at an ultrahigh current density of 5 A g-1, and exhibit a high capacity of 938 mAh g-1 at 0.1 A g-1 with excellent capacity retention in the following 300 cycles. The significantly enhanced Li-storage properties should be attributed to the co-existence of both highly conductive graphite and amorphous carbon in the Si/C/G composite. While the former can enhance the electrical conductivity of the obtained composite, the latter acts as the adhesives to connect the porous Si particulates and conductive graphite flakes to form robust and stable conductive network.

  15. Mesoporous wormholelike carbon with controllable nanostructure for lithium ion batteries application

    International Nuclear Information System (INIS)

    Highlights: • Wormholelike carbon (WMC) with controllable nanostructure is prepared by sol–gel method. • The reversible capacity of WMC is much higher than that of many other reported nanocarbons. • The effect of pore diameter on Li storage capacity is investigated. - Abstract: A class of mesoporous wormholelike carbon (WMC) with controllable nanostructure was prepared by sol–gel method and then used as the anode material of lithium-ion batteries. Based on the experimental results, it is found that the nanostructure of the as-prepared WMC plays an important role in the electrochemical performances. A suitable mesopore size is necessary for a high performance carbon-based anode material since it can not only guarantee effective mass transport channels but also provide large surface area. As a result, F30 with a mesopore size of 4.4 nm coupled with high surface area of 1077 m2 g−1 shows a reversible capacity of 630 mAh g−1, much higher than commercial graphite and many other reported nanocarbons

  16. Electrochemical Performance of Iron Diphosphide/Carbon Tube Nanohybrids in Lithium-ion Batteries

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted -- Highlights: • Dehydrogenated FeP2/C nanohybrids were fabricated via a facile annealing process. • The nanohybrids as anode in LIB show excellent cycling stability and rate capability. • C-hybrid promotes buffering volume change and increasing electroconductibility. • The process can be applied for the fabrication of many more TMPs and nanohybrids. -- Abstract: Phosphorous-rich phase iron diphosphide/carbon tube (FeP2/C) nanohybrids, which are synthesized via a pyrolysis process and composed of heterostructures of orthorhombic FeP2 with conical carbon tubes, have been identified as a new anode in lithium-ion batteries. After an annealing treatment to eliminate the excessive hydrogen elements in the carbon tubes, the FeP2/C nanohybrids display good reversible capacity, long cycle life, and excellent rate capability. Specifically, the annealed hybrids exhibit a discharge capacity of 602 mA h g−1 on the second cycle and a discharge capacity of 435 mA h g−1 after 100 cycles at 0.1C (0.137 A g−1). Meanwhile, these annealed hybrids exhibit excellent rate capability, such as a reversible capability of 510 mA h g−1, 440 mA h g−1, 380 mA h g−1, 330 mA h g−1 and 240 mA h g−1 at 0.25C, 0.5C, 1C, 2.5C and 5C, respectively

  17. Asymmetric hydration structure around calcium ion restricted in micropores fabricated in activated carbons

    Science.gov (United States)

    Ohkubo, Takahiro; Kusudo, Tomoko; Kuroda, Yasushige

    2016-11-01

    The adsorbed phase and hydration structure of an aqueous solution of Ca(NO3)2 restricted in micropores fabricated in activated carbons (ACs) having different average pore widths (0.63 and 1.1 nm) were investigated with the analysis of adsorption isotherms and x-ray absorption fine structure (XAFS) spectra on Ca K-edge. The adsorbed density of Ca2+ per unit micropore volume in the narrower pore was higher than in the wider pore, while the adsorbed amount per unit mass of carbon with the narrower pore was half of the amount of ACs with the larger pore. On the other hand, variations in the bands assigned to double-electron (KM I) and 1s  →  3d excitations in XAFS spectra demonstrate the formation of a distorted hydration cluster around Ca2+ in the micropore, although the structural parameters of hydrated Ca2+ in the micropores were almost consistent with the bulk aqueous solution, as revealed by the analysis of extended XAFS (EXAFS) spectra. In contrast to the hydration structure of monovalent ions such as Rb+, which generally presents a dehydrated structure in smaller than 1 nm micropores in ACs, the present study clearly explains that the non-spherically-symmetric structure of hydrated Ca2+ restricted in carbon micropores whose sizes are around 1 nm is experimentally revealed where any dehydration phenomena from the first hydration shell around Ca2+ could not be observed.

  18. Optimization of carbon ion and proton treatment plans using the raster-scanning technique for patients with unresectable pancreatic cancer

    International Nuclear Information System (INIS)

    The aim of the thesis is to improve radiation plans of patients with locally advanced, unresectable pancreatic cancer by using carbon ion and proton beams. Using the treatment planning system Syngo RT Planning (Siemens, Erlangen, Germany) a total of 50 treatment plans have been created for five patients with the dose schedule 15 × 3 Gy(RBE). With reference to the anatomy, five field configurations were considered to be relevant. The plans were analyzed with respect to dose distribution and individual anatomy, and compared using a customized index. Within the index the three-field configurations yielded the best results, though with a high variety of score points (field setup 5, carbon ion: median 74 (range 48–101)). The maximum dose in the myelon is low (e.g. case 3, carbon ion: 21.5 Gy(RBE)). A single posterior field generally spares the organs at risk, but the maximum dose in the myelon is high (e.g. case 3, carbon ion: 32.9 Gy(RBE)). Two oblique posterior fields resulted in acceptable maximum doses in the myelon (e.g. case 3, carbon ion: 26.9 Gy(RBE)). The single-field configuration and the two oblique posterior fields had a small score dispersion (carbon ion: median 66 and 58 (range 62–72 and 40–69)). In cases with topographic proximity of the organs at risk to the target volume, the single-field configuration scored as well as the three-field configurations. In summary, the three-field configurations showed the best dose distributions. A single posterior field seems to be robust and beneficial in case of difficult topographical conditions and topographical proximity of organs at risk to the target volume. A setup with two oblique posterior fields is a reasonable compromise between three-field and single-field configurations

  19. Carbon-ion beam irradiation kills X-ray-resistant p53-null cancer cells by inducing mitotic catastrophe.

    Directory of Open Access Journals (Sweden)

    Napapat Amornwichet

    Full Text Available BACKGROUND AND PURPOSE: To understand the mechanisms involved in the strong killing effect of carbon-ion beam irradiation on cancer cells with TP53 tumor suppressor gene deficiencies. MATERIALS AND METHODS: DNA damage responses after carbon-ion beam or X-ray irradiation in isogenic HCT116 colorectal cancer cell lines with and without TP53 (p53+/+ and p53-/-, respectively were analyzed as follows: cell survival by clonogenic assay, cell death modes by morphologic observation of DAPI-stained nuclei, DNA double-strand breaks (DSBs by immunostaining of phosphorylated H2AX (γH2AX, and cell cycle by flow cytometry and immunostaining of Ser10-phosphorylated histone H3. RESULTS: The p53-/- cells were more resistant than the p53+/+ cells to X-ray irradiation, while the sensitivities of the p53+/+ and p53-/- cells to carbon-ion beam irradiation were comparable. X-ray and carbon-ion beam irradiations predominantly induced apoptosis of the p53+/+ cells but not the p53-/- cells. In the p53-/- cells, carbon-ion beam irradiation, but not X-ray irradiation, markedly induced mitotic catastrophe that was associated with premature mitotic entry with harboring long-retained DSBs at 24 h post-irradiation. CONCLUSIONS: Efficient induction of mitotic catastrophe in apoptosis-resistant p53-deficient cells implies a strong cancer cell-killing effect of carbon-ion beam irradiation that is independent of the p53 status, suggesting its biological advantage over X-ray treatment.

  20. Structure and properties of Mo-containing diamond-like carbon films produced by ion source assisted cathodic arc ion-plating

    International Nuclear Information System (INIS)

    Ion source assisted cathodic arc ion-plating was used to synthesize molybdenum containing diamond-like carbon films. The element of molybdenum is uniformly distributed in our sample as analyzed by Rutherford backscattering spectroscopy. The surface morphology of the films was analyzed by scanning electron microscope and atomic force microscope. The structure and bond state of the molybdenum containing diamond-like carbon films were characterized by X-ray diffraction, high resolution transmission electron microscopy, Raman spectra, and X-ray photoelectron spectroscopy. The Mo content in the films was controlled by varying of the acetylene gas flow rates. The root-mean square roughness of the as-deposited sample was found in the range of 1.5 nm. The hardness of 35 GPa has been achieved at the optimum conditions of synthesis. This can be attributed to formation multilayer structure during deposition process and the formation of hard molybdenum carbide phase with C=Mo bonding. The results show that ion source assisted cathodic arc ion-plating is an effective technique to fabricate metal-containing carbon films with controlled metal contents.

  1. A mechanical nanogate based on a carbon nanotube for reversible control of ion conduction.

    Science.gov (United States)

    He, Zhongjin; Corry, Ben; Lu, Xiaohua; Zhou, Jian

    2014-04-01

    Control of mass transport through nanochannels is of critical importance in many nanoscale devices and nanofiltration membranes. The gates in biological channels, which control the transport of substances across cell membranes, can provide inspiration for this purpose. Gates in many biological channels are formed by a constriction ringed with hydrophobic residues which can prevent ion conduction even when they are not completely physically occluded. In this work, we use molecular dynamics simulations to design a nanogate inspired by this hydrophobic gating mechanism. Deforming a carbon nanotube (12,12) with an external force can form a hydrophobic constriction in the centre of the tube that controls ion conduction. The simulation results show that increasing the magnitude of the applied force narrows the constriction and lowers the fluxes of K(+) and Cl(-) found under an electric field. With the exerted force larger than 5 nN, the constriction blocks the conduction of K(+) and Cl(-) due to partial dehydration while allowing for a noticeable water flux. Ion conduction can revert back to the unperturbed level upon force retraction, suggesting the reversibility of the nanogate. The force can be exerted by available experimental facilities, such as atomic force microscope (AFM) tips. It is found that partial dehydration in a continuous water-filled hydrophobic constriction is enough to close the channel, while full dewetting is not necessarily required. This mechanically deformed nanogate has many potential applications, such as a valve in nanofluidic systems to reversibly control ion conduction and a high-performance nanomachine for desalination and water treatment. PMID:24566473

  2. EVALUATION OF ADSORPTION OF COPPER IONS IN THE PERLITE USING DIFFERENTIAL PULSE VOLTAMMETRY EMPLOYING A CHITOSAN MODIFIED GLASSY CARBON ELECTRODE

    OpenAIRE

    NOGUEIRA, James Pyetro do Amaral; CARVALHO, Araújo Daniel; MARTINEZ-HUITLE, CarlosAlberto; FERNANDES, Nedja Suely

    2011-01-01

    In this work the perlite, an aluminosilicate constituted by 72.1% of SiO2 and 18.5% of Al2O3 was evaluated as an adsorbent of copper ions in aqueous solution using the differential pulse voltammetry technique employing a chitosan modified glassy carbon electrode (EMQ). The adsorption tests performed in the range from 5 to 30 min indicated that an adsorption of copper ions around 73% at time of 30 min was achivied.

  3. Fast neutron dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    DeLuca, P.M. Jr.; Pearson, D.W.

    1992-01-01

    This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period.

  4. INDIVIDUAL DOSIMETRY SERVICE

    CERN Multimedia

    2000-01-01

    Personnel in the distribution groups Aleph, Delphi, L3, Opal who also work for other experiments than at LEP, should contact their dispatchers to explain their activities for the future, after LEP dismantling in order to be maintained on the regular distribution list at Individual Dosimetry ServiceWe inform all staffs and users under regular dosimetric control that the dosimeters for the monitoring period JULY/AUGUST are available from their usual dispatchers.Please have your films changed before the 10th of July.The colour of the dosimeter valid in JULY/AUGUST is PINK.

  5. Individual dosimetry and calibration

    International Nuclear Information System (INIS)

    In 1995 both the Individual Dosimetry and Calibration Sections worked under the condition of a status quo and concentrated fully on the routine part of their work. Nevertheless, the machine for printing the bar code which will be glued onto the film holder and hence identify the people when entering into high radiation areas was put into operation and most of the holders were equipped with the new identification. As far as the Calibration Section is concerned the project of the new source control system that is realized by the Technical Support Section was somewhat accelerated

  6. Carbon-Confined SnO2-Electrodeposited Porous Carbon Nanofiber Composite as High-Capacity Sodium-Ion Battery Anode Material.

    Science.gov (United States)

    Dirican, Mahmut; Lu, Yao; Ge, Yeqian; Yildiz, Ozkan; Zhang, Xiangwu

    2015-08-26

    Sodium resources are inexpensive and abundant, and hence, sodium-ion batteries are promising alternative to lithium-ion batteries. However, lower energy density and poor cycling stability of current sodium-ion batteries prevent their practical implementation for future smart power grid and stationary storage applications. Tin oxides (SnO2) can be potentially used as a high-capacity anode material for future sodium-ion batteries, and they have the advantages of high sodium storage capacity, high abundance, and low toxicity. However, SnO2-based anodes still cannot be used in practical sodium-ion batteries because they experience large volume changes during repetitive charge and discharge cycles. Such large volume changes lead to severe pulverization of the active material and loss of electrical contact between the SnO2 and carbon conductor, which in turn result in rapid capacity loss during cycling. Here, we introduce a new amorphous carbon-coated SnO2-electrodeposited porous carbon nanofiber (PCNF@SnO2@C) composite that not only has high sodium storage capability, but also maintains its structural integrity while ongoing repetitive cycles. Electrochemical results revealed that this SnO2-containing nanofiber composite anode had excellent electrochemical performance including high-capacity (374 mAh g(-1)), good capacity retention (82.7%), and large Coulombic efficiency (98.9% after 100th cycle). PMID:26252051

  7. An Accelerated Test Method of Simultaneous Carbonation and Chloride Ion Ingress: Durability of Silica Fume Concrete in Severe Environments

    Directory of Open Access Journals (Sweden)

    S. A. Ghahari

    2016-01-01

    Full Text Available The effects of simultaneous carbonation and chloride ion attack on mechanical characteristics and durability of concrete containing silica fume have been investigated through an accelerated test method. Specimens containing different amounts of silica fume were maintained in an apparatus in which carbon dioxide pressure and concentration and relative humidity were kept constant, and wetting and drying cycles in saline water were applied. Surface resistivity, sorptivity, CO2 consumption, and carbonation and chloride ion ingress depths measurements were taken. Phase change due to carbonation and chloride ion attack was monitored by XRD analysis, and microstructures and interfacial transition zones were studied by implementing SEM as well as mercury intrusion porosimetry. It was expected to have a synergistic effect in the tidal zone where simultaneous carbonation and chloride ion attack happen. However, the observed reduced surface resistivity, compared to specimens maintained in CO2 gas, could be due to the moisture that is available near the surface, hindering CO2 from penetrating into the pores of the specimens. Moreover, the porosity analysis of the specimens showed that the sample containing silica fume cured in the tidal zone had 50.1% less total porosity than the plain cement paste cured in the same condition.

  8. Transition Metal Ion Implantation into Diamond-Like Carbon Coatings: Development of a Base Material for Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Andreas Markwitz

    2015-01-01

    Full Text Available Micrometre thick diamond-like carbon (DLC coatings produced by direct ion deposition were implanted with 30 keV Ar+ and transition metal ions in the lower percentage (<10 at.% range. Theoretical calculations showed that the ions are implanted just beneath the surface, which was confirmed with RBS measurements. Atomic force microscope scans revealed that the surface roughness increases when implanted with Ar+ and Cu+ ions, whereas a smoothing of the surface from 5.2 to 2.7 nm and a grain size reduction from 175 to 93 nm are measured for Ag+ implanted coatings with a fluence of 1.24×1016 at. cm−2. Calculated hydrogen and carbon depth profiles showed surprisingly significant changes in concentrations in the near-surface region of the DLC coatings, particularly when implanted with Ag+ ions. Hydrogen accumulates up to 32 at.% and the minimum of the carbon distribution is shifted towards the surface which may be the cause of the surface smoothing effect. The ion implantations caused an increase in electrical conductivity of the DLC coatings, which is important for the development of solid-state gas sensors based on DLC coatings.

  9. Structural and mechanical characterization of ion-irradiated glassy polymeric carbon for TRISO fuel nuclear application

    Science.gov (United States)

    Abunaemeh, Malek; Seif, Mohamed; Elsamadicy, Abdalla; Ila, Daryush

    2012-08-01

    Tristructural isotropic (TRISO) fuel is considered as the fuel design of choice for the next generation of nuclear reactors (Generation IV). Its design consists of a fuel kernel of UO x coated with several layers having different functions. One of these functions is a containment shell/diffusion barrier for the fission fragments. Normally, the material of choice for this shell is pyrolytic carbon (PyC). The material does not offer a perfect barrier, due to its inherent crystalline structure, which is planar (like graphite) and therefore impossible to mold in one continuous sheet around the spherical fuel bead. Plane boundaries allow fragment diffusion at a much higher rate than through the plane. In this study, we investigate the possibility of replacing PyC with a different form of carbon, glassy polymeric carbon (GPC). We prepared samples of GPC and studied the evolution of their physical properties and structure as a function of the radiation environment that they were exposed to. The temperature at which the samples were held during irradiation was very similar to the Generation IV nuclear reactor (∼1000°C). During the fission of U235, the fission fragment mass distribution has two maxima around 98 and 137 amu, which would best correspond to elements Rb and Cs, respectively. However, both ions are hard to produce from our SNICS ion source at the Center for Irradiation of Materials; therefore, we used 107Ag and 197Au as best replacements. The irradiation sessions consisted in various fluences of 5 MeV Ag, and 5 MeV Au. For elemental sample analysis, we used transmission electron microscopy. For mechanical analysis, we used nano-indentation. It is of prime importance to measure the penetration of the implanted 107Ag.and 197Au and the evolution of mechanical properties of GPC irradiated with these ions. A procedure for manufacturing GPC with analysis is presented. This will show how the GPC structure differs as the temperature that it is prepared at increases

  10. Particle beam radiation therapy using carbon ions and protons for oligometastatic lung tumors

    International Nuclear Information System (INIS)

    A study was undertaken to analyze the efficacy and feasibility of particle beam radiation therapy (PBRT) using carbon ions and protons for the treatment of patients with oligometastatic lung tumors. A total of 47 patients with 59 lesions who underwent PBRT for oligometastatic lung tumors between 2003 and 2011 were included in this study. Patient median age was 66 (range, 39–84) years. The primary tumor site was the colorectum in 11 patients (23.4%), lung in 10 patients (21.3%) and a variety of other sites in 26 patients (55.3%). Thirty-one patients (66%) received chemotherapy prior to PBRT. Thirty-three lesions were treated with 320-MeV carbon ions and 26 were treated with 150- or 210-Mev protons in 1–4 portals. A median total dose of 60 (range, 52.8–70.2) GyE was delivered at the isocenter in 8 (range, 4–26) fractions. The median follow-up time was 17 months. The local control, overall survival and progression-free survival rates at 2 years were 79%, 54 and 27% respectively. PBRT-related toxicities were observed; six patients (13%) had grade 2 toxicity (including grade 2 radiation pneumonitis in 2) and six patients (13%) had grade 3 toxicity. Univariate analysis indicated that patients treated with a biologically equivalent dose of 10 (BED10) <110 GyE10, had a significantly higher local recurrence rate. Local control rates were relatively lower in the subsets of patients with the colorectum as the primary tumor site. No local progression was observed in metastases from colorectal cancer irradiated with a BED10 ≥ 110 GyE10. There was no difference in treatment results between proton and carbon ion therapy. PRBT is well tolerated and effective in the treatment of oligometastatic lung tumors. To further improve local control, high-dose PBRT with a BED10 ≥ 110 GyE10 may be promising. Further investigation of PBRT for lung oligometastases is warranted

  11. An Accelerated Test Method of Simultaneous Carbonation and Chloride Ion Ingress: Durability of Silica Fume Concrete in Severe Environments

    OpenAIRE

    Ghahari, S. A.; Ramezanianpour, A. M.; Ramezanianpour, A. A.; Esmaeili, M

    2016-01-01

    The effects of simultaneous carbonation and chloride ion attack on mechanical characteristics and durability of concrete containing silica fume have been investigated through an accelerated test method. Specimens containing different amounts of silica fume were maintained in an apparatus in which carbon dioxide pressure and concentration and relative humidity were kept constant, and wetting and drying cycles in saline water were applied. Surface resistivity, sorptivity, CO2 consumption, and c...

  12. TL dosimetry in the new Tandetron ion accelerator site of the National Institute of Nuclear Research (ININ); Dosimetria TL en el area del nuevo acelerador de iones Tandetron del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Valdovinos A, M.; Gonzalez M, P.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The National Institute of Nuclear Research (ININ) acquired a positive ions accelerator type Tandetron 2 MV of the dutch company High Voltage Engineering, Europe B.V., which was finished its installation this year (2000) in an already existing building in the Dr. Nabor Carrillo Flores Nuclear Centre, where it was prepared for the following purposes: the accelerator will be used to realize research through X-ray emission induced by charged particles, Rutherford backscattering analysis, nuclear reaction analysis, gamma ray emission induced by charged particles, resonant dispersion analysis, elastic backward detection analysis and by particle canalization analysis. The accelerator consists of an injection system with two ion sources, ion accelerator tank with voltage in terminal at 2 MV, recovery and recirculation system of charge interchange gas, iman selector analyzer system and with high energy focussing, control system through computer and management and recovery of isolator gas system. For the realization of operation tests of this accelerator, it was had the license authorizing by the National Commission of Nuclear Safety and Safeguards (CNSNS). During the test stage Tl dosemeters were arranged in the Tandetron accelerator area, and also in direction to the beam outlet. In this work, are presented the obtained results of the measurement of radiation levels, as in the area as in the beam outlet. (Author)

  13. Study of small carbon and semiconductor clusters using negative ion threshold photodetachment spectroscopy

    International Nuclear Information System (INIS)

    The bonding and electronics of several small carbon and semiconductor clusters containing less than ten atoms are probed using negative ion threshold photodetachment (zero electron kinetic energy, or ZEKE) spectroscopy. ZEKE spectroscopy is a particularly advantageous technique for small cluster study, as it combines mass selection with good spectroscopic resolution. The ground and low-lying electronic states of small clusters in general can be accessed by detaching an electron from the ground anion state. The clusters studied using this technique and described in this work are C6-/C6, Sin-/Sin (n = 2, 3, 4), Ge2-/Ge2, In2P-/In2P,InP2-/InP2, and Ga2As-. The total photodetachment cross sections of several other small carbon clusters and the ZEKE spectrum of the I-·CH3I SN2 reaction complex are also presented to illustrate the versatility of the experimental apparatus. Clusters with so few atoms do not exhibit bulk properties. However, each specie exhibits bonding properties that relate to the type of bonding found in the bulk. C6, as has been predicted, exhibits a linear cumulenic structure, where double bonds connect all six carbon atoms. This double bonding reflects how important π bonding is in certain phases of pure carbon (graphite and fullerenes). The symmetric stretch frequencies observed in the C6- spectra, however, are in poor agreement with the calculated values. Also observed as sharp structure in total photodetachment cross section scans was an excited anion state bound by only ∼40 cm-1 relative to the detachment continuum. This excited anion state appears to be a valence bound state, possible because of the high electron affinity of C6, and the open shell of the anion

  14. Graphitized boron-doped carbon foams: Performance as anodes in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Elena; Camean, Ignacio; Garcia, Roberto [Instituto Nacional del Carbon (CSIC), C/Francisco Pintado Fe 26, 33011 Oviedo (Spain); Garcia, Ana B., E-mail: anabgs@incar.csic.es [Instituto Nacional del Carbon (CSIC), C/Francisco Pintado Fe 26, 33011 Oviedo (Spain)

    2011-05-30

    Highlights: > Because of the catalytic effect of boron, graphite-like foams were prepared. > The presence of substitutional boron in carbon foams improves their anodic performance. > The graphitized boron-doped foams provide reversible capacities of 310 mA h g{sup -1}. - Abstract: The electrochemical performance as potential anodes in lithium-ion batteries of several boron-doped and non-doped graphitic foams with different degree of structural order was investigated by galvanostatic cycling. The boron-doped foams were prepared by the co-pyrolysis of a coal and two boron sources (boron oxide and a borane-pyridine complex), followed by heat treatment in the 2400-2800 deg. C temperature interval. The extent of the graphitization process of the carbon foams depends on boron concentration and source. Because of the catalytic effect of boron, lightweight graphite-like foams were prepared. Boron in the foams was found to be present as carbide (B{sub 4}C), in substitutional positions in the carbon lattice (B-C), bonded to nitrogen (B-N) and forming clusters. Larger reversible lithium storage capacities with values up to {approx}310 mA h g{sup -1} were achieved by using the boron oxide-based carbon foams. Moreover, since the electrochemical anodic performance of these boron-doped foams with different degree of structural order is similar, the beneficial effect of the presence of the B-C boron phase was inferred. However, the bonding of boron with nitrogen in the pyridine borane-based has a negative effect on lithium intercalation.

  15. Stable cyclic performance of nickel oxide–carbon composite anode for lithium-ion batteries

    International Nuclear Information System (INIS)

    Nickel oxide (NiO) directly grown on nickel foam is regarded as a promising lithium ion battery anode material which shows good cyclic and rate performances with a theoretical specific capacity of 718 mA h g−1. In this study, we demonstrated a carbon-incorporated NiO anode (NiO–C) with a capacity per unit area of 2.11 mA h cm−2 and 1.76 mA h cm−2 at 0.2 C and 0.5 C rates, respectively, fabricated by thermal oxidation of carbon coated nickel foam. The specific capacity of our NiO–C composite samples at 0.5 C rate is found to be typically 389.16 mA h g−1, with a stable cyclic performance up to more than 100 cycles. This remarkable performance is apparently superior to the control samples of pure NiO samples. The improved performance is contributed to carbon incorporation which serves as a fluent channel for electrons and a flexible network preventing NiO nanostructures from structural deformation during charge and discharge processes. The advantage of using our approach is the easy preparation of the NiO–C composite using a simple two-step process: chemical vapor deposition of ethanol and annealing in air. - Highlights: • We demonstrated a directly grown NiO–C anode on nickel foam substrate. • NiO–C anode was made using simple processes: CVD of ethanol and annealing in air. • The NiO–C anode has a stable cycle life up to 102 cycles. • It has an acceptable areal capacity (1.76 mA h cm−2 at 0.5 C rate) for practical use. • Carbon provides electrons path and buffering matrix preventing NiO pulverization

  16. Analytical expressions for stopping-power ratios relevant for accurate dosimetry in particle therapy

    CERN Document Server

    Lühr, Armin; Jäkel, Oliver; Sobolevsky, Nikolai; Bassler, Niels

    2010-01-01

    In particle therapy, knowledge of the stopping-power ratios (STPRs) of the ion beam for air and water is necessary for accurate ionization chamber dosimetry. Earlier work has investigated the STPRs for pristine carbon ion beams, but here we expand the calculations to a range of ions (1 <= z <= 18) as well as spread out Bragg peaks (SOBPs) and provide a theoretical in-depth study with a special focus on the parameter regime relevant for particle therapy. The Monte Carlo transport code SHIELD-HIT is used to calculate complete particle-fluence spectra which are required for determining STPRs according to the recommendations of the International Atomic Energy Agency (IAEA). We confirm that the STPR depends primarily on the current energy of the ions rather than on their charge z or absolute position in the medium. However, STPRs for different sets of stopping-power data for water and air recommended by the International Commission on Radiation Units & Measurements (ICRU) are compared, including also the...

  17. New Insight into the Interaction between Carbonate-based Electrolyte and Cuprous Sulfide Electrode Material for Lithium Ion Batteries

    International Nuclear Information System (INIS)

    Cuprous sulfide (Cu2S) is attractive electrode material for lithium-ion battery because of its high capacity and energy density. Interestingly, the cycling stability of cuprous sulfide is poor in the carbonate-based electrolytes used in lithium ion battery industry but excellent in ether-based electrolyte. In this study, we have compared the electrochemical performance of commercially available cuprous sulfide in various kinds of carbonate-based electrolytes. Our results show that the specific capacity of Cu2S electrode fades quickly in cyclic carbonate-based electrolytes, but a much better electrochemical performance in linear carbonate-based electrolytes. In linear carbonate-based electrolyte (1 M LiPF6 in EMC), it exhibits a specific discharge capacity of 242.8 mAh g−1 after 50 cycles with coulombic efficiency of 99.6%. Our study suggests that the poor cycling performance of Cu2S in cyclic carbonate-based electrolytes is mainly due to the higher reactivity of cyclic carbonates with polysulfides on the surface of the electrode than linear carbonates, which was confirmed for the first time by our experiment studies and theoretical calculation

  18. Characteristics of a high brightness gaseous field ion source employing tungsten-carbon doped NiAl needles.

    Science.gov (United States)

    Mousa, Marwan S

    2011-05-01

    We report on the characterization of a high brightness gaseous field ion source using an emitter made of a NiAl needle containing tiny spherical tungsten-carbon precipitates. By field evaporation of such a multiphase alloy, a surface protrusion is formed out of a precipitate, which can act as a small source size field ion emitter. The emission current-voltage characteristics of this emitter were recorded for a variety of parameters. The results obtained suggest that its application as a stable ion source is possible even on long term operation. PMID:21296502

  19. Measurement of neutron-production double-differential cross-sections on carbon bombarded with 290-MeV/nucleon carbon and oxygen ions

    International Nuclear Information System (INIS)

    Neutron-production double-differential cross-sections on carbon-carbon and oxygen-carbon reactions with incident heavy-ion energy of 290 MeV/nucleon were measured by time-of-flight method using liquid organic scintillators. By use of a detection system specialized for low-energy neutrons, the cross-sections were obtained in a wide energy region from several hundred MeV down to 0.6 MeV for the oxygen-ion incidences. The experimental data were compared with the calculation results using the Monte-Carlo simulation code, PHITS. The PHITS results gave an overall agreement with the measured data within a factor of two.

  20. Imaging the interphase of carbon fiber composites using transmission electron microscopy:Preparations by focused ion beam, ion beam etching, and ultramicrotomy

    Institute of Scientific and Technical Information of China (English)

    Wu Qing; Li Min; Gu Yizhuo; Wang Shaokai; Zhang Zuoguang

    2015-01-01

    Three sample preparation techniques, focused ion beam (FIB), ion beam (IB) etching, and ultramicrotomy (UM) were used in comparison to analyze the interphase of carbon fiber/epoxy composites using transmission electron microscopy. An intact interphase with a relatively uniform thickness was obtained by FIB, and detailed chemical analysis of the interphase was investigated by electron energy loss spectroscopy. It shows that the interphase region is 200 nm wide with an increasing oxygen-to-carbon ratio from 10% to 19% and an almost constant nitrogen-to-carbon ratio of about 3%. However, gallium implantation of FIB tends to hinder fine structure analysis of the interphase. For IB etching, the interphase region is observed with transition morphology from amorphous resin to nano-crystalline carbon fiber, but the uneven sample thickness brings difficulty for quantitative chemical analysis. Moreover, UM tends to cause damage and/or deformation on the interphase. These results are meaningful for in-depth understanding on the interphase characteristic of carbon fiber composites.

  1. Internal Dosimetry. Chapter 18

    International Nuclear Information System (INIS)

    The Committee on Medical Internal Radiation Dose (MIRD) is a committee within the Society of Nuclear Medicine. The MIRD Committee was formed in 1965 with the mission to standardize internal dosimetry calculations, improve the published emission data for radionuclides and enhance the data on pharmacokinetics for radiopharmaceuticals [18.1]. A unified approach to internal dosimetry was published by the MIRD Committee in 1968, MIRD Pamphlet No. 1 [18.2], which was updated several times thereafter. Currently, the most well known version is the MIRD Primer from 1991 [18.3]. The latest publication on the formalism was published in 2009 in MIRD Pamphlet No. 21 [18.4], which provides a notation meant to bridge the differences in the formalism used by the MIRD Committee and the International Commission on Radiological Protection (ICRP) [18.5]. The formalism presented in MIRD Pamphlet No. 21 [18.4] will be used here, although some references to the quantities and parameters used in the MIRD primer [18.3] will be made. All symbols, quantities and units are presented

  2. Characteristics of a high brightness gaseous field ion source employing tungsten-carbon doped NiAl needles

    Energy Technology Data Exchange (ETDEWEB)

    Mousa, Marwan S., E-mail: mmousa@mutah.edu.jo [Department of Physics, Mu' tah University, P.O. Box 7, Al-Karak (Jordan)

    2011-05-15

    We report on the characterization of a high brightness gaseous field ion source using an emitter made of a NiAl needle containing tiny spherical tungsten-carbon precipitates. By field evaporation of such a multiphase alloy, a surface protrusion is formed out of a precipitate, which can act as a small source size field ion emitter. The emission current-voltage characteristics of this emitter were recorded for a variety of parameters. The results obtained suggest that its application as a stable ion source is possible even on long term operation. -- Research highlights: {yields} High brightness gaseous field ion source of precipitation hardened NiAl+W+C emitter. {yields} Emission current-voltage characteristics are recorded for a variety of parameters. {yields} Very small virtual source sizes and energy spreads can be attained. {yields} Results suggest that application as long term stable ion source is possible.

  3. Conductive additive content balance in Li-ion battery cathodes: Commercial carbon blacks vs. in situ carbon from LiFePO{sub 4}/C composites

    Energy Technology Data Exchange (ETDEWEB)

    Palomares, Veronica; Goni, Aintzane; Muro, Izaskun Gil de; Rojo, Teofilo [Departamento de Quimica Inorganica, Universidad del Pais Vasco UPV/EHU, P.O. Box. 644, 48080, Bilbao (Spain); de Meatza, Iratxe; Bengoechea, Miguel [Energy Department, CIDETEC-IK4, P Miramon 196, Parque Tecnologico de San Sebastian, 20009, San Sebastian (Spain); Cantero, Igor [Departamento I+D+i Nuevas Tecnologias, CEGASA, Artapadura, 11, 01013 Vitoria-Gasteiz (Spain)

    2010-11-15

    Two samples of commercial conducting carbon black and the carbon generated in situ during LiFePO{sub 4}/C composite synthesis from citric acid are studied, with the aim of finding out whether carbon from the composite can fulfil the same function as carbon black in the electrode blend for a Li-ion battery. For this purpose, the carbon samples are analyzed by several techniques, such as X-ray diffraction, Raman spectroscopy, transmission electron microscopy, granulometry, BET specific area and conductivity measurements. Different cathode compositions and component proportions are tested for pellet and cast electrodes. Electrochemical results show that a moderate reduction of commercial carbon black content in both kinds of cathodes, by adding more LiFePO{sub 4}/C composite, enhanced the electrochemical behaviour by around 10%. In situ generated carbon can partially replace commercial conducting carbon black because its high specific surface probably enhances electrolyte penetration into the cathode, but it is always necessary to maintain a minimum amount of carbon black that provides better conductivity in order to obtain a good electrochemical response. (author)

  4. Carbon-coated SnSb nanoparticles dispersed in reticular structured nanofibers for lithium-ion battery anodes

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Xiao [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education, Shanghai 201620 (China); Zhou, Huimin; Li, Zhiyong; Shan, Xiaohong [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Xia, Xin, E-mail: xjxiaxin@163.com [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education, Shanghai 201620 (China)

    2015-01-25

    Highlights: • Sn{sub 0.92}Sb{sub 0.08}O{sub 2.04} nanoparticles as SnSb alloy precursor. • Carbon-coated SnSb nanoparticles were prepared and then embedded in carbon nanofibers. • The synergic effect of carbon coating and special structure improved cycling stability. - Abstract: Carbon coating and carbon nanofiber processes were used to enhance the cycling performance of SnSb alloys. Carbon-coated SnSb alloys were firstly prepared by a simple hydrothermal method to build the first protection, and then carbon-coated SnSb nanoparticles were embedded in carbon nanofibers via single-spinneret electrospinning followed by carbonization. The crystal structure of carbon-coated SnSb/C hybrid nanofibers was characterized by X-ray diffraction (XRD). The morphologies of carbon-coated SnSb alloys and hybrid nanofibers were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The thermal stability of hybrid nanofibers were determined by thermogravimetric analysis (TGA). The electrochemical properties were investigated as a potential high-capacity anode material for lithium-ion batteries. The results showed that the hybrid nanofibers exhibited excellent electrochemical performance due to the special structure. The carbon shell can effectively hinder the agglomeration of SnSb alloys, while maintaining electronic conduction as well as accommodating drastic volume changes during lithium insertion and extraction and carbon nanofibers formed a further protection. The resultant carbon-coated SnSb nanoparticles dispersed in carbon nanofibers deliver a high capacity of 674 mA h g{sup −1} and a good capacity retention of 68.7% after 50 cycles.

  5. The effect of chloride ion on the iron elution from carbon steel in high temperature water

    International Nuclear Information System (INIS)

    In Hamaoka-5 nuclear power plant, the sea water entered into the reactor during the shutdown on May in 2011. The structural materials were exposed to the high temperature water containing chloride ion (Cl-). Carbon steel is less corrosion-resistant than stainless steel and the corrosion might be accelerated. Oxide growth of carbon steel may cause the change of Co-60 deposition behavior during the operation. Then the perceiving the state of oxide film on the surface of carbon steel is important. We conducted the corrosion tests for 24hrs with carbon steel under high temperature water containing Cl- to estimate the state of the surface and iron elution of the actual plant. In the cases of the prefilmed specimens, without Cl-, the amount of iron elution was small at 513 K. On the other hand, under the water condition containing Cl- iron elution from carbon steel occurred. The iron elution rate under the water condition of 423 K was slightly faster than 513 K. The average values of iron elution rate under the condition of 400ppm as Cl- were approximately 0.03 mg/cm2/h. The dependency of Cl- concentration on iron elution rate did not appear at the both of 423 and 513 K. In the case of the specimens without oxide film, the iron elution rate under the water condition of 423 K was much faster than 513 K under the water conditions with and without Cl-. The iron elution rate of the specimens without oxide film was affected by the concentration of Cl- with the exception of the test at 423 K. At the higher Cl- concentration, iron elution was accelerated. Furthermore, we conducted the corrosion tests at 323 K for 500 hours which simulated the water condition after the shutdown of the reactor. It was also confirmed that iron apparently eluted from the specimen in these tests. This result indicated that iron elution possibly occurred in the actual plant. The analyses of the oxide film on the surface of specimens after the several tests were conducted. We also discussed the

  6. Encapsulation of metal oxide nanocrystals into porous carbon with ultrahigh performances in lithium-ion battery.

    Science.gov (United States)

    Ming, Jun; Park, Jin-Bum; Sun, Yang-Kook

    2013-03-01

    A simple and industrial scalable approach was developed to encapsulate metal oxide nanocrystals into porous carbon (PC) with a high distribution. With this method, the composite of PC-metal oxide were prepared in a large amount with a low cost; particularly they exhibit ultrahigh performances in lithium-ion battery applications. For example, the PC-CoOx and PC-FeOx show a high capacity around 1021 mA h g(-1) and 1200 mA h g(-1) at the current density of 100 mA g(-1) respectively, together with an excellent cycling ability (>400 cycles) and rate capacity even at the high current densities of 3 A g(-1) and 5 A g(-1).

  7. Carbon ion beam treatment in patients with primary and recurrent sacrococcygeal chordoma

    Energy Technology Data Exchange (ETDEWEB)

    Uhl, Matthias; Jensen, Alexandra; Herfarth, Klaus [University of Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Heidelberg Ion Beam Therapy Center (HIT), Heidelberg (Germany); Welzel, Thomas [University of Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Ellerbrock, Malte; Haberer, Thomas [Heidelberg Ion Beam Therapy Center (HIT), Heidelberg (Germany); Jaekel, Oliver [University of Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Heidelberg Ion Beam Therapy Center (HIT), Heidelberg (Germany); German Cancer Research Center (dkfz), Heidelberg (Germany); Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); Debus, Juergen [University of Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Heidelberg Ion Beam Therapy Center (HIT), Heidelberg (Germany); German Cancer Research Center (dkfz), Heidelberg (Germany); Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); Deutsches Konsortium fuer Translationale Krebsforschung (DKTK), Heidelberg (Germany)

    2015-07-15

    The purpose of this work was to evaluate the results of high-dose radiation treatment using carbon ion therapy, alone or combined with intensity-modulated radiation treatment (IMRT), in patients with sacral chordoma. Between 2009 and 2012, 56 patients with sacral chordoma were treated in our center. The tumor was located above S3 in 33 patients and in S3 or below in 23 patients. In all, 41 patients received radiation therapy for the primary tumor, while 15 patients were treated for the recurrent tumor. Toxicity was measured using NCI CTCAE v.4.03. Local control (LC) and overall survival (OS) were evaluated with the Kaplan-Meier method. A total of 23 patients were irradiated with carbon ions in combination with photon IMRT, while 33 received carbon ion therapy only. Forty-three patients had a macroscopic tumor at treatment start with a median tumor size (GTV) of 244 ml (range 5-1188 ml). The median total dose was 66 Gy (range 60-74 Gy; RBE). After a median follow-up time of 25 months, the 2- and 3-year local control probability was 76 % and 53 %, respectively. The overall survival rate was 100 %. Treatment for primary tumor and male patients resulted in significant better local control. No higher toxicity occurred within the follow-up time. High-dose photon/carbon ion beam radiation therapy is safe and, especially for primary sacral chordomas, highly effective. A randomized trial is required to evaluate the role of primary definitive hypofractionated particle therapy compared with surgery with or without adjuvant radiotherapy. (orig.) [German] Evaluierung der Ergebnisse nach hochdosierter Kohlenstoffionentherapie, allein oder in Kombination mit einer intensitaetsmodulierten Photonenbestrahlung (IMRT), bei Patienten mit einem sakralen Chordom. Zwischen 2009 und 2012 wurden 56 Patienten mit sakralen Chordomen in unserem Zentrum behandelt. Der Tumor war bei 33 Patienten oberhalb von S3 und bei 23 Patienten auf Hoehe von S3 oder unterhalb davon lokalisiert. Insgesamt

  8. Preparation and Characterization of Carbon Coated Silicon Nanoparticle as Anode Material for Li-ion Batteries

    Institute of Scientific and Technical Information of China (English)

    T. Zhancg; L.J. Fu; J. Gao; Y. P. Wu; H.Q. Wu

    2005-01-01

    @@ 1Introduction Silicon has been regarded as one of the most promising anode materials for Li-ion batteries. Its theoretical capacity (4 000 mAh/g) is much higher than that of the commercialized graphite (372 mAh/g)[1]. However,the cycle performance of silicon is poor due to the severe volume expansion and shrinkage during Li+ insertion/extraction which results in pulverization of Si particles, eventually losing its Li+ storage ability[2]. To solve this problem, nanosized Si particles were utilized and achieved a partial improvement by reducing the absolute volume change. Nevertheless, a new problem was encountered with nanosized material that small Si particles were aggregated to be larger one during Li+ insertion/extraction, and then pulverized again[3]. In this work, we have succeeded to improve the cycle performance of nanosized Si particles by synthesis of carbon coated silicon nanoparticle.

  9. Fluorescent carbon dots for sensitive determination and intracellular imaging of zinc(II) ion

    International Nuclear Information System (INIS)

    We describe the preparation of carbon dots (CDs) from glucose that possess high stability, a quantum yield of 0.32, and low toxicity (according to an MTT assay). They were used, in combination with the fluorogenic zinc(II) probe quercetin to establish a fluorescence resonance energy transfer (FRET) system for the determination of Zn(II). The CDs are acting as the donor, and the quercetin-Zn(II) complex as the acceptor. This is possible because of the strong overlap between the fluorescence spectrum of CDs and the absorption spectrum of the complex. The method enables Zn(II) to be determined in the 2 to 100 μM concentration range, with a 2 μM detection limit. The method was applied to image the distribution of Zn(II) ions in HeLa cells. (author)

  10. Fabrication of Diamond-like Carbon Films by Ion Assisted Middle Frequency Unbalanced Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi-chen; SUN Shao-ni; ZHOU Yi; MA Sheng-ge; BA De-chun

    2006-01-01

    Diamond-like carbon (DLC) films are deposited by the Hall ion source assisted by the mid-frequency unbalanced magnetron sputtering technique. The effects of the substrate voltage bias, the substrate temperature, the Hall discharging current and the argon/nitrogen ratio on the DLC film's performance were studied. The experimental results show that the film's surface roughness, the hardness and the Young's modulus increase firstly and then decrease with the bias voltage incrementally increases. Also when the substrate temperature rises, the surface roughness of the film varies slightly, but its hardness and Young's modulus firstly increase followed by a sharp decrease when the temperature surpassing 120 ℃. With the Hall discharging current incrementally rising, the hardness and Young's modulus of the film decrease and the surface roughness of the film on 316L stainless steel firstly decreased and then remains constant.

  11. Understanding the Photoluminescence Mechanism of Nitrogen-Doped Carbon Dots by Selective Interaction with Copper Ions.

    Science.gov (United States)

    Ganiga, Manjunatha; Cyriac, Jobin

    2016-08-01

    Doped fluorescent carbon dots (CDs) have drawn widespread attention because of their diverse applications and attractive properties. The present report focusses on the origin of photoluminescence in nitrogen-doped CDs (NCDs), which is unraveled by the interaction with Cu(2+) ions. Detailed spectroscopic and microscopic studies reveal that the broad steady-state photoluminescence emission of the NCDs originates from the direct recombination of excitons (high energy) and the involvement of defect states (low energy). In addition, highly selective detection of Cu(2+) is achieved, with a detection limit of 10 μm and a dynamic range of 10 μm-0.4 mm. The feasibility of the present sensor for the detection of Cu(2+) in real water samples is also presented. PMID:27159128

  12. Single ionization of helium atoms by energetic fully stripped carbon ions

    Institute of Scientific and Technical Information of China (English)

    Ebrahim Ghanbari-Adivi; Sadjad Eskandari

    2015-01-01

    A four-body distorted wave approximation is presented for theoretical investigations of the single ionization of ground-state helium atoms by fully stripped carbon ions at impact energies of 2 MeV/amu and 100 MeV/amu. The nine-dimensional integrals for the partial quantum-mechanical transition amplitudes of the specified reaction are reduced to some analytical expressions or one-dimensional integrals over real variables. Fully differential cross sections (FDCSs) are calculated and compared with their experimental values as well as the results obtained from other theories. Despite the simplicity and quickness of the proposed quadrature, the comparison shows that the obtained results are in reasonable agreement with the experiment and are compatible with those of other complicated theories.

  13. Improved Lithium Ion Behavior Properties of TiO2@Graphitic-like Carbon Core@Shell Nanostructure

    International Nuclear Information System (INIS)

    Highlights: • The TiO2@C nanostructure (NS) consists of TiO2 as a core and carbon as a shell. • The carbon layer of TiO2@C NS shows graphitic-like properties. • The TiO2@C NS exhibits high electrical conductivity due to carbon layer. • The TiO2@C NS shows low charge transfer resistance and high diffusion coefficient. • The TiO2@C NS exhibits enhanced lithium ion intercalation properties. - Abstract: We demonstrate TiO2@graphitic-like carbon core@shell (TiO2@C) nanostructures using chemical vapor deposition as the heating process under a CH4 atmosphere at 700 °C (TiO2@C-700). The TiO2@C-700 nanostructure consists of a TiO2 core coated by a carbon shell. The carbon shells on TiO2 nanostructures generally have 2∼3 layers exhibiting graphitic-like properties. The TiO2@C-700 nanostructure is homogeneously covered with a graphite-like carbon layer, resulting in excellent contact between the TiO2 and carbon and improving the electrical conductivity. The improved specific capacity and electrochemical properties of the TiO2@C-700 nanostructure are attributed to the graphitic-like carbon acting as a conductive region, resulting in improved electron transport properties on the electrode surface and enhanced lithium ion intercalation, leading to lower charge transfer resistance and high diffusion coefficient. The combination of electrochemical data and structural properties of the TiO2@C-700 nanostructure makes it a promising candidate for the anode in lithium ion batteries

  14. Carbon ion radiotherapy for oligo-recurrent lung metastases from colorectal cancer: a feasibility study

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the efficacy and feasibility of carbon ion radiotherapy (CIRT) for oligo-recurrent lung tumors from colorectal cancer (CRC). From May 1997 to October 2012, 34 consecutive patients with oligo-recurrent pulmonary metastases from CRC were treated with CIRT. The patients were not surgical candidates for medical reasons or patient refusal. Using a respiratory-gated technique, carbon ion therapy was delivered with curative intent using 4 coplanar beam angles. A median dose of 60 GyE (range, 44–64.8 GyE) was delivered to the planning target volume (PTV), with a median daily dose of 15 GyE (range, 3.6–44 GyE). Treatment outcome was analyzed in terms of local control rate (LCR), survival rate, and treatment-related complications. In total, 34 patients with 44 oligo-recurrent pulmonary lesions were treated with CIRT. Median follow-up period was 23.7 months. The 2- and 3-year actuarial LCRs of the treated patients were 85.4% ± 6.2% and 85.4% ± 6.2%, respectively. Overall survival was 65.1% ± 9.5% at 2 years, and 50.1% ± 10.5% at 3 years. Although survival rates were relatively worse in the subsets of patients aged < 63 years or with early metastasis (< 36 months after resection of primary site), these factors were not significantly correlated with overall survival (P = 0.13 and 0.19, respectively). All treatment-related complications were self-limited, without any grade 3–5 toxicity. CIRT is one of the most effective nonsurgical treatments for colorectal lung metastases, which are relatively resistant to stereotactic body radiotherapy. CIRT is considered to be the least invasive approach even in patients who have undergone repeated prior thoracic metastasectomies

  15. Copper Nanoparticle-Incorporated Carbon Fibers as Free-Standing Anodes for Lithium-Ion Batteries.

    Science.gov (United States)

    Han, Pan; Yuan, Tao; Yao, Long; Han, Zhuo; Yang, Junhe; Zheng, Shiyou

    2016-12-01

    Copper-incorporated carbon fibers (Cu/CF) as free-standing anodes for lithium-ion batteries are prepared by electrospinning technique following with calcination at 600, 700, and 800 °C. The structural properties of materials are characterized by X-ray diffraction (XRD), Raman, thermogravimetry (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectrometry (EDS). It is found that the Cu/CF composites have smooth, regular, and long fibrous morphologies with Cu nanoparticles uniformly dispersed in the carbon fibers. As free-standing anodes, the unique structural Cu/CF composites show stable and high reversible capacities, together with remarkable rate and cycling capabilities in Li-ion batteries. The Cu/CF calcined at 800 °C (Cu/CF-800) has the highest charge/discharge capacities, long-term stable cycling performance, and excellent rate performance; for instance, the Cu/CF-800 anode shows reversible charge/discharge capacities of around 800 mAh g(-1) at a current density of 100 mA g(-1) with stable cycling performance for more than 250 cycles; even when the current density increases to 2 A g(-1), the Cu/CF-800 anode can still deliver a capacity of 300 mAh g(-1). This excellent electrochemical performance is attributed to the special 1D structure of Cu/CF composites, the enhanced electrical conductivity, and more Li(+) active positions by Cu nanoinclusion. PMID:27033848

  16. Information from the Dosimetry Service

    CERN Multimedia

    2006-01-01

    Please note the following opening hours of the Service: From 31st July onwards: Every morning from 8:30 to 12:00 The Service is closed in the afternoons. We should like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCTs) must always be returned to the Service after use and must not be left on the racks in the experimental areas or in the secretariats. Dosimetry Service Tel 72155 Bldg. 24 E 011 Dosimetry.service@cern.ch http://cern.ch/rp-dosimetry

  17. Friction and Wear of Ion-Beam-Deposited Diamondlike Carbon on Chemical-Vapor-Deposited, Fine-Grain Diamond

    Science.gov (United States)

    Miyoshi, Kazuhisa; Wu, Richard L. C.; Lanter, William C.

    1996-01-01

    Friction and wear behavior of ion-beam-deposited diamondlike carbon (DLC) films coated on chemical-vapor-deposited (CVD), fine-grain diamond coatings were examined in ultrahigh vacuum, dry nitrogen, and humid air environments. The DLC films were produced by the direct impact of an ion beam (composed of a 3:17 mixture of Ar and CH4) at ion energies of 1500 and 700 eV and an RF power of 99 W. Sliding friction experiments were conducted with hemispherical CVD diamond pins sliding on four different carbon-base coating systems: DLC films on CVD diamond; DLC films on silicon; as-deposited, fine-grain CVD diamond; and carbon-ion-implanted, fine-grain CVD diamond on silicon. Results indicate that in ultrahigh vacuum the ion-beam-deposited DLC films on fine-grain CVD diamond (similar to the ion-implanted CVD diamond) greatly decrease both the friction and wear of fine-grain CVD diamond films and provide solid lubrication. In dry nitrogen and in humid air, ion-beam-deposited DLC films on fine-grain CVD diamond films also had a low steady-state coefficient of friction and a low wear rate. These tribological performance benefits, coupled with a wider range of coating thicknesses, led to longer endurance life and improved wear resistance for the DLC deposited on fine-grain CVD diamond in comparison to the ion-implanted diamond films. Thus, DLC deposited on fine-grain CVD diamond films can be an effective wear-resistant, lubricating coating regardless of environment.

  18. Cyclability study of silicon-carbon composite anodes for lithium-ion batteries using electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Guo Juchen; Sun, Ann; Chen Xilin [Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742 (United States); Wang Chunsheng, E-mail: cswang@umd.ed [Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742 (United States); Manivannan, Ayyakkannu [US Department of Energy, National Energy Technology Laboratory, Morgantown, WV 26507 (United States)

    2011-04-15

    Research highlights: {yields} Silicon-carbon anode materials for Li-ion batteries were synthesized. {yields} Carbonization and annealing processes were used in electrode preparation. {yields} Capacity fading mechanism was investigated by electrochemical impedance spectroscopy. {yields} Impedance evolution revealed better stability of the carbonized anode material. - Abstract: The effects of carbonization process and carbon nanofiber/nanotube additives on the cycling stability of silicon-carbon composite anodes were investigated by monitoring the impedance evolution during charge/discharge cycles with electrochemical impedance spectroscopy (EIS). Three types of Si-C anodes were investigated: the first type consisted of Si nanoparticles incorporated into a network of carbon nanofibers (CNFs) and multi-walled carbon nanotubes (MWNTs), with annealed polymer binder. The second type of Si-C anodes was prepared by further heat treatment of the first Si-C anodes to carbonize the polymer binder. The third Si-C anode was as same as the second one except no CNFs and MWNTs being added. Impedance analysis revealed that the carbonization process stabilized the Si-C anode structure and decreased the charge transfer resistance, thus improving the cycling stability. On the other hand, although the MWNTs/CNFs additives could enhance the electronic conductivity of the Si-C anodes, the induced inhomogeneous structure decreased the integrity of the electrode, resulting in a poor long term cycling stability.

  19. Induction of apoptosis in murione spleen lymphocytes using carbon ion beam; Induction de l'apoptose dans les lymphocytes spleniques de souris par un faisceau d'ions carbone

    Energy Technology Data Exchange (ETDEWEB)

    Holl, V.; Coelho, D. [Lab. de Cancerologie Experimentale et de Radiobiologie, LCER, Inst. de Recherche contre les Cancers de l' Appareil Digestif, Hopitaux Universitaires, Strasbourg (France); Weltin, D. [Faculte de Medecine, Strasbourg (France); Dufour, P. [Lab. de Cancerologie Experimentale et de Radiobiologie, LCER, Inst. de Recherche contre les Cancers de l' Appareil Digestif, Hopitaux Universitaires, Strasbourg (France); Denis, J.M. [Faculte de Medecine, Univ. Catholique de Louvain, Bruxelles (Belgium); Florentin, I. [Centre National de la Recherche Scientifique, CNRS, Unite de Recherche Associee, Hopital Cochin, Paris (France); Mathieu, J. [Centre de Recherche du Service de Sante des Armees, CRSSA, La Tronche (France); Gueulette, J. [Faculte de Medecine, Univ. Catholique de Louvain, Bruxelles (Belgium); Bischoff, P. [Lab. de Cancerologie Experimentale et de Radiobiologie, LCER, Inst. de Recherche contre les Cancers de l' Appareil Digestif, Hopitaux Universitaires, Strasbourg (France)

    2001-02-01

    To assess the capacity of heavy ions to induce apoptosis in lymphocytes, mice have been irradiated with accelerated carbon ions (95 MeV/nucleon) at doses ranging from 0.1 to 4 Gy. Their spleens were removed 24 h later and gently dissociated to prepare a single cell suspension. Mononuclear cells were then maintained in culture at 37{sup o}C, and the occurrence of apoptosis in these cells was analysed 24 h later. Lymphocytes were also irradiated in vitro, in the presence of Ac-DEVD-CHO, a potent caspase-3 and -7 inhibitor. Results from three experiments performed at the Grand Accelerateur National d'Ions Lourds (GANIL, Caen, France) are reported here. They indicate that carbon ions induce a marked, dose-dependent, reduction of the spleen weight and cellularity. However, in sharp contrast with spleen cells prepared from X-ray irradiated mice, only a slight increase of apoptosis is evidenced in cultured lymphocytes from mice irradiated with heavy ions. The significance of such results is discussed. So far, few data exist concerning the biological effects of heavy ions, in particular their capacity to induce apoptosis in lymphocytes; the present study provides useful clues for further investigations. (author)

  20. Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium-Ion Batteries.

    Science.gov (United States)

    Yang, Fuhua; Yu, Fan; Zhang, Zhian; Zhang, Kai; Lai, Yanqing; Li, Jie

    2016-02-12

    Sodium-ion batteries (SIBs) are regarded as an attractive alternative to lithium-ion batteries (LIBs) for large-scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g(-1) after 100 cycles at 100 mA g(-1) . The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g(-1) are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g(-1) , respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres.

  1. Transition metal oxide-carbon composites as conversion anodes for sodium-ion battery

    International Nuclear Information System (INIS)

    Herein, we characterize various metal oxide-carbon composites, i.e. CuO-MCMB (mesocarbon microbeads), Fe2O3–MCMB and NiO-MCMB, as anode materials for application in sodium-ion battery. The electrodes, supposed to react through a conversion mechanism, are studied in terms of structure, morphology and electrochemical behavior in sodium cell. The results demonstrate a specific capacity of the order of 100 mAh g−1 for Fe2O3–MCMB and NiO-MCMB, and of about 300 mAh g−1 for CuO-MCMB. The remarkable performance of the latter suggests the copper oxide-based electrode as the preferred anode material for battery application. Indeed, further study aimed to clarify the Na/CuO-MCMB reaction mechanism is performed by ex-situ X-ray diffraction on electrode material cast onto aluminum support. The study suggests a partial conversion reaction for CuO-based anode that is considered suitable candidate in replacement of sodium metal, in efficient and safe Na-ion battery

  2. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    CERN Document Server

    Tanaka, T; Shinohara, M; Takagi, T

    2002-01-01

    Application of pulsed high negative voltage (approx 10 mu s pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N sub 2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N sub 2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron mic...

  3. Radiation effects on bipolar junction transistors induced by 25 MeV carbon ions

    Science.gov (United States)

    Liu, Chaoming; Li, Xingji; Geng, Hongbin; Zhao, Zhiming; Yang, Dezhuang; He, Shiyu

    2010-12-01

    The characteristic degradation in silicon NPN bipolar junction transistors (BJTs) of 3DG112 type is examined under the irradiation with 25 MeV carbon (C) ions and various bias conditions. Different electrical parameters were measured in-situ during the exposure under each bias condition. From the experimental data, larger variation of base current ( IB) is observed after irradiation at a given value of base-emitter voltage ( VBE), while the collector current is only slightly affected by irradiation at a given VBE. The gain degradation is mostly affected by the behavior of the base current. The change in the reciprocal of current gain (Δ(1/ β)) increases linearly with increasing the C ions fluence. The degradation of the NPN BJTs under various bias conditions during irradiation was studied. Compared to the case where the terminals are grounded, at a given fluence, the change in the reciprocal of current gain varies slightly less when the base-emitter junction is forward biased. On the other hand, there is no distinction for the change in the reciprocal of current gain between the case of reverse-biased base-emitter junction and that of all terminals grounded for the NPN BJTs at a given fluence.

  4. Study of the magnets used for a mobile isocenter carbon ion gantry.

    Science.gov (United States)

    Moreno, Jhonnatan Osorio; Pullia, Marco G; Priano, Cristiana; Lante, Valeria; Necchi, Monica M; Savazzi, Simone

    2013-07-01

    A conceptual design of a mobile isocenter carbon ion gantry was carried out in the framework of the Particle Training Network for European Radiotherapy (PARTNER) and Union of Light Ion Centres in Europe (ULICE) projects. To validate the magnets used in this gantry, Finite Element Method (FEM) simulations were performed with COMSOL multiphysics; the purpose was to evaluate the magnetic field quality and the influence of additional support structures for correctors, 90° bending dipole and quadrupoles, both in dynamic and static regimes. Due to the low ramp rates, the dynamic effects do not disturb the homogeneity and the magnetic field level. The differences between the stationary field and the corresponding dynamic field after the end of the ramps are in the order of 10(-4); it implies that the magnets can be operated without significant field lag at the nominal ramp rate. However, even in static regime the magnetic length of corrector magnet decreases by 5% when the rotator mechanical structure is considered. The simulations suggest an optimization phase of the correctors in the rotator.

  5. Effect of carbon ion irradiation on Ag diffusion in SiC

    Science.gov (United States)

    Leng, Bin; Ko, Hyunseok; Gerczak, Tyler J.; Deng, Jie; Giordani, Andrew J.; Hunter, Jerry L.; Morgan, Dane; Szlufarska, Izabela; Sridharan, Kumar

    2016-04-01

    Transport of Ag fission product through the silicon-carbide (SiC) diffusion barrier layer in TRISO fuel particles is of considerable interest given the application of this fuel type in high temperature gas-cooled reactor (HTGR) and other future reactor concepts. The reactor experiments indicate that radiation may play an important role in release of Ag; however so far the isolated effect of radiation on Ag diffusion has not been investigated in controlled laboratory experiments. In this study, we investigate the diffusion couples of Ag and polycrystalline 3C-SiC, as well as Ag and single crystalline 4H-SiC samples before and after irradiation with C2+ ions. The diffusion couple samples were exposed to temperatures of 1500 °C, 1535 °C, and 1569 °C, and the ensuing diffusion profiles were analyzed by secondary ion mass spectrometry (SIMS). Diffusion coefficients calculated from these measurements indicate that Ag diffusion was greatly enhanced by carbon irradiation due to a combined effect of radiation damage on diffusion and the presence of grain boundaries in polycrystalline SiC samples.

  6. Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium-Ion Batteries.

    Science.gov (United States)

    Yang, Fuhua; Yu, Fan; Zhang, Zhian; Zhang, Kai; Lai, Yanqing; Li, Jie

    2016-02-12

    Sodium-ion batteries (SIBs) are regarded as an attractive alternative to lithium-ion batteries (LIBs) for large-scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g(-1) after 100 cycles at 100 mA g(-1) . The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g(-1) are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g(-1) , respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres. PMID:26757402

  7. Study on elution ability of salicylic acid on ion exchange resins in supercritical carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    Ping YUAN; Jianguo CAI; Junjie GONG; Xiu DENG

    2009-01-01

    The elution ability of salicylic acid on ion exchange resins in supercritical carbon dioxide has been studied. Some factors influencing elution recovery,including entrainer, temperature, pressure and the flow rate of supercritical fluid CO2 are discussed in this work.The addition of a small amount of entrainer, such as ethanol, triethanolamine and their mixture to supercritical CO2 can cause dramatic effects on the elution ability. The results show that the salicylic acid can be only slightly eluted from the resin with supercritical CO2 alone with temperatures ranging from 307.15 to 323.15K and pressures ranging from 10 to 30MPa. Meanwhile, with the same T, P conditions, 40.58% and 73.08% salicylic acid can be eluted from the ion exchange resin with ethanol and ethanol + triethanolamine as the entrainer, respec-tively. An improved PR equation of state with VDWl mixing rules is used to calculate the elution recovery of salicylic acid in supercritical CO2 and the results agree well with the experimental data.

  8. Carbon Heavy-ion Radiation Induced Biological effects on Oryza sativa L.

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Li, Xishan; Gong, Ning; Meng, Qingmei; Liu, Jiawei; Wang, Ting

    2016-07-01

    Large number of researches on rice after spaceflights indicated that rice was a favorable model organism to study biological effects induced by space radiation. The stimulative effect could often be found on rice seedlings after irradiation by low-dose energetic heavy-ion radiation. Spaceflight also could induce stimulative effect on kinds of seeds. To further understand the mechanism of low-dose radiation biological effects and the dose range, the germinated rice seeds which were irradiated by different doses of carbon heavy-ion (0, 0.02, 0.1, 0.2, 1, 2, 5, 10, 15 and 20Gy, LET=27.3keV/µm) were used as materials to study. By investigating the variation of rice phenotype under different doses, we found that 2Gy radiation dose was a dividing point of the phenotypic variation. Transmission electron microscopy was used to observe the variation of mitochondria, chloroplast, endoplasmic reticulum, ribosome and nucleus in mesophyll cell of rice apical meristem at 24 hours after radiation with different doses. The cells were not apparently physiologically damaged when the dose of radiation was less than 2Gy. The number of chloroplast did not change significantly, but the number of mitochondria was significantly increased, and gathered around in the chloroplast and endoplasmic reticulum; the obvious lesion of chloroplast and mitochondria were found at the mesophyll cells when radiation dose was higher than 2Gy. The mitochondria were swelling and appearing blurred crest. The chloroplast and mitochondrial mutation rate increased significantly (pplant. Keywords: Heavy-ion radiation; Low dose; Stimulation effect; Inhibition effect; Rice.

  9. Aligned carbon nanotube-silicon sheets: a novel nano-architecture for flexible lithium ion battery electrodes.

    Science.gov (United States)

    Fu, Kun; Yildiz, Ozkan; Bhanushali, Hardik; Wang, Yongxin; Stano, Kelly; Xue, Leigang; Zhang, Xiangwu; Bradford, Philip D

    2013-09-25

    Aligned carbon nanotube sheets provide an engineered scaffold for the deposition of a silicon active material for lithium ion battery anodes. The sheets are low-density, allowing uniform deposition of silicon thin films while the alignment allows unconstrained volumetric expansion of the silicon, facilitating stable cycling performance. The flat sheet morphology is desirable for battery construction.

  10. Evidence of double layer/capacitive charging in carbon nanomaterial-based solid contact polymeric ion-selective electrodes.

    Science.gov (United States)

    Cuartero, Maria; Bishop, Josiah; Walker, Raymart; Acres, Robert G; Bakker, Eric; De Marco, Roland; Crespo, Gaston A

    2016-08-11

    This paper presents the first direct spectroscopic evidence for double layer or capacitive charging of carbon nanomaterial-based solid contacts in all-solid-state polymeric ion-selective electrodes (ISEs). Here, we used synchrotron radiation-X-ray photoelectron spectroscopy (SR-XPS) and SR valence band (VB) spectroscopy in the elucidation of the charging mechanism of the SCs.

  11. Evidence of double layer/capacitive charging in carbon nanomaterial-based solid contact polymeric ion-selective electrodes.

    Science.gov (United States)

    Cuartero, Maria; Bishop, Josiah; Walker, Raymart; Acres, Robert G; Bakker, Eric; De Marco, Roland; Crespo, Gaston A

    2016-08-11

    This paper presents the first direct spectroscopic evidence for double layer or capacitive charging of carbon nanomaterial-based solid contacts in all-solid-state polymeric ion-selective electrodes (ISEs). Here, we used synchrotron radiation-X-ray photoelectron spectroscopy (SR-XPS) and SR valence band (VB) spectroscopy in the elucidation of the charging mechanism of the SCs. PMID:27405722

  12. Corrosion Inhibiting Mechanism of Nitrite Ion on the Passivation of Carbon Steel and Ductile Cast Iron for Nuclear Power Plants

    Directory of Open Access Journals (Sweden)

    K. T. Kim

    2015-01-01

    Full Text Available While NaNO2 addition can greatly inhibit the corrosion of carbon steel and ductile cast iron, in order to improve the similar corrosion resistance, ca. 100 times more NaNO2 addition is needed for ductile cast iron compared to carbon steel. A corrosion and inhibition mechanism is proposed whereby NO2- ion is added to oxidize. The NO2- ion can be reduced to nitrogen compounds and these compounds may be absorbed on the surface of graphite. Therefore, since nitrite ion needs to oxidize the surface of matrix and needs to passivate the galvanic corroded area and since it is absorbed on the surface of graphite, a greater amount of corrosion inhibitor needs to be added to ductile cast iron compared to carbon steel. The passive film of carbon steel and ductile cast iron, formed by NaNO2 addition showed N-type semiconductive properties and its resistance, is increased; the passive current density is thus decreased and the corrosion rate is then lowered. In addition, the film is mainly composed of iron oxide due to the oxidation by NO2- ion; however, regardless of the alloys, nitrogen compounds (not nitrite were detected at the outermost surface but were not incorporated in the inner oxide.

  13. Charge-exchange measurements of fully-stripped oxygen and carbon ion radial density profiles in TFR

    International Nuclear Information System (INIS)

    Fully-ionized oxygen and carbon ions have been detected in TFR via charge-exchange recombination spectroscopy using a modulated auxiliary neutral beam, thus allowing their radial density profiles to be obtained. An impurity transport numerical code is then used to deduce the impurity transport parameters

  14. Bystander effects induced by the low-fluence irradiation of carbon and iron ions (6 MeV/n)

    International Nuclear Information System (INIS)

    Many reports are available regarding bystander effects after exposure to low fluences of alpha particles and helium ions. However, few studies have examined bystander cellular effects after exposure to low fluences of ion species heavier than helium. We has been investigating bystander effects using both human normal fibroblasts and tumor cell lines irradiated with low energy (6 MeV/n) carbon or iron ions generated with the Medium Energy Beam Course. This year we focused on the bystander cellular effects as follows; Bystander cell-killing effect in human tumor cell lines irradiated with carbon ions. Relationship of bystander lethal effect between p53-wild and p53-mutated cells. Bystander cell-killing effect was observed in human normal and tumor cells harboring wild-type p53, but not in p53-mutated tumor cells. Moreover, observed bystander effect was suppressed by treating with a specific inhibitor of gap-junction mediated cell-cell communication. There is evidence that p53- and gap-junction-related bystander effect is an important role of carbon-ion induced lethal effect. (author)

  15. Theoretical insight into oxidative decomposition of propylene carbonate in the lithium ion battery.

    Science.gov (United States)

    Xing, Lidan; Wang, Chaoyang; Li, Weishan; Xu, Mengqing; Meng, Xuliang; Zhao, Shaofei

    2009-04-16

    The detailed oxidative decomposition mechanism of propylene carbonate (PC) in the lithium ion battery is investigated using density functional theory (DFT) at the level of B3LYP/6-311++G(d), both in the gas phase and in solvent. The calculated results indicate that PC is initially oxidized on the cathode to a radical cation intermediate, PC(*+), and then decomposes through three pathways, generating carbon dioxide CO(2) and radical cations. These radical cations prefer to be reduced on the anode or by gaining one electron from PC, forming propanal, acetone, or relevant radicals. The radicals terminate by forming final products, including trans-2-ethyl-4-methyl-1,3-dioxolane, cis-2-ethyl-4-methyl-1,3-dioxolane, and 2,5-dimethyl-1,4-dioxane. Among all the products, acetone is most easily formed. The calculations in this paper give detailed explanations of the experimental findings that have been reported in the literature and clarify the role of intermediate propylene oxide in PC decomposition. Propylene oxide is one of the important intermediates. As propylene oxide is formed, it isomerizes forming a more stabile product, acetone.

  16. Silicon-Encapsulated Hollow Carbon Nanofiber Networks as Binder-Free Anodes for Lithium Ion Battery

    Directory of Open Access Journals (Sweden)

    Ding Nan

    2014-01-01

    Full Text Available Silicon-encapsulated hollow carbon nanofiber networks with ample space around the Si nanoparticles (hollow Si/C composites were successfully synthesized by dip-coating phenolic resin onto the surface of electrospun Si/PVA nanofibers along with the subsequent solidification and carbonization. More importantly, the structure and Si content of hollow Si/C composite nanofibers can be effectively tuned by merely varying the concentration of dip solution. As-synthesized hollow Si/C composites show excellent electrochemical performance when they are used as binder-free anodes for Li-ion batteries (LIBs. In particular, when the concentration of resol/ethanol solution is 3.0%, the product exhibits a large capacity of 841 mAh g−1 in the first cycle, prominent cycling stability, and good rate capability. The discharge capacity retention of it was ~90%, with 745 mAh g−1 after 50 cycles. The results demonstrate that the hollow Si/C composites are very promising as alternative anode candidates for high-performance LIBs.

  17. Heteroatom Doped-Carbon Nanospheres as Anodes in Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    George S. Pappas

    2016-01-01

    Full Text Available Long cycle performance is a crucial requirement in energy storage devices. New formulations and/or improvement of “conventional” materials have been investigated in order to achieve this target. Here we explore the performance of a novel type of carbon nanospheres (CNSs with three heteroatom co-doped (nitrogen, phosphorous and sulfur and high specific surface area as anode materials for lithium ion batteries. The CNSs were obtained from carbonization of highly-crosslinked organo (phosphazene nanospheres (OPZs of 300 nm diameter. The OPZs were synthesized via a single and facile step of polycondensation reaction between hexachlorocyclotriphosphazene (HCCP and 4,4′-sulphonyldiphenol (BPS. The X-ray Photoelectron Spectroscopy (XPS analysis showed a high heteroatom-doping content in the structure of CNSs while the textural evaluation from the N2 sorption isotherms revealed the presence of micro- and mesopores and a high specific surface area of 875 m2/g. The CNSs anode showed remarkable stability and coulombic efficiency in a long charge–discharge cycling up to 1000 cycles at 1C rate, delivering about 130 mA·h·g−1. This study represents a step toward smart engineering of inexpensive materials with practical applications for energy devices.

  18. Size Effect of Ordered Mesoporous Carbon Nanospheres for Anodes in Li-Ion Battery

    Directory of Open Access Journals (Sweden)

    Pei-Yi Chang

    2015-12-01

    Full Text Available The present work demonstrates the application of various sizes of ordered mesoporous carbon nanospheres (OMCS with diameters of 46–130 nm as an active anode material for Li-ion batteries (LIB. The physical and chemical properties of OMCS have been evaluated by performing scanning electron microscopy (SEM, transmission electron microscopy (TEM, N2 adsorption-desorption analysis; small-angle scattering system (SAXS and X-ray diffraction (XRD. The electrochemical analysis of using various sizes of OMCS as anode materials showed high capacity and rate capability with the specific capacity up to 560 mA·h·g−1 at 0.1 C after 85 cycles. In terms of performance at high current rate compared to other amorphous carbonaceous materials; a stable and extremely high specific capacity of 240 mA·h·g−1 at 5 C after 15 cycles was achieved. Such excellent performance is mainly attributed to the suitable particle size distribution of OMCS and intimate contact between OMCS and conductive additives; which can be supported from the TEM images. Results obtained from this study clearly indicate the excellence of size distribution of highly integrated mesoporous structure of carbon nanospheres for LIB application.

  19. Sb nanoparticles encapsulated into porous carbon matrixes for high-performance lithium-ion battery anodes

    Science.gov (United States)

    Yi, Zheng; Han, Qigang; Zan, Ping; Wu, Yaoming; Cheng, Yong; Wang, Limin

    2016-11-01

    A novel Sb/C polyhedra composite is successfully fabricated by a galvanic replacement reaction technique using metal organic frameworks as templates. In this composite, the ultrasmall Sb nanoparticles with an average size of 15 nm are homogeneously encapsulated into the carbon matrixes, forming a hierarchical porous structure with nanosized building blocks. Used as an anode material for lithium ion batteries, this composite exhibits high lithium storage capacities, excellent rate capability and superior cycle stability, higher than many reported results. Notably, a discharge capacity of 565 mAh g-1 at a current density of 0.2 A g-1 is delivered after 100 repeated cycles. Even at a high current density of 1 A g-1, a discharge capacity of 400.5 mAh g-1 is also maintained after 500 cycles. Such superior cycling stability and rate discharge performance of the designed Sb/C composite can be attributed to the synergistic effect between Sb nanoparticles and the porous carbon matrixes.

  20. The complex ion structure of warm dense carbon measured by spectrally resolved x-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, D.; Barbrel, B.; Falcone, R. W. [Department of Physics, University of California, Berkeley, California 94720 (United States); Vorberger, J. [Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden (Germany); Helfrich, J.; Frydrych, S.; Ortner, A.; Otten, A.; Roth, F.; Schaumann, G.; Schumacher, D.; Siegenthaler, K.; Wagner, F.; Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt (Germany); Gericke, D. O.; Wünsch, K. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Bachmann, B.; Döppner, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bagnoud, V.; Blažević, A. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); and others

    2015-05-15

    We present measurements of the complex ion structure of warm dense carbon close to the melting line at pressures around 100 GPa. High-pressure samples were created by laser-driven shock compression of graphite and probed by intense laser-generated x-ray sources with photon energies of 4.75 keV and 4.95 keV. High-efficiency crystal spectrometers allow for spectrally resolving the scattered radiation. Comparing the ratio of elastically and inelastically scattered radiation, we find evidence for a complex bonded liquid that is predicted by ab-initio quantum simulations showing the influence of chemical bonds under these conditions. Using graphite samples of different initial densities we demonstrate the capability of spectrally resolved x-ray scattering to monitor the carbon solid-liquid transition at relatively constant pressure of 150 GPa. Showing first single-pulse scattering spectra from cold graphite of unprecedented quality recorded at the Linac Coherent Light Source, we demonstrate the outstanding possibilities for future high-precision measurements at 4th Generation Light Sources.