WorldWideScience

Sample records for carbon ions

  1. 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...... to the surface where the beam enters) are examined. For each plan the minimum,  maximum and the dose averaged LET of the PTV is calculated. The numbers are translated to OER using several sets of data found in literature for various cell lines. Results: We find a strong dependence of the dose average LET and OER...... 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....

  2. 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...

  3. 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.

  4. 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)

  5. 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.)

  6. 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.

  7. Enhanced lithium ion storage in nanoimprinted carbon

    International Nuclear Information System (INIS)

    Disordered carbons processed from polymers have much higher theoretical capacity as lithium ion battery anode than graphite, but they suffer from large irreversible capacity loss and have poor cyclic performance. Here, a simple process to obtain patterned carbon structure from polyvinylpyrrolidone was demonstrated, combining nanoimprint lithography for patterning and three-step heat treatment process for carbonization. The patterned carbon, without any additional binders or conductive fillers, shows remarkably improved cycling performance as Li-ion battery anode, twice as high as the theoretical value of graphite at 98 cycles. Localized electrochemical strain microscopy reveals the enhanced lithium ion activity at the nanoscale, and the control experiments suggest that the enhancement largely originates from the patterned structure, which improves surface reaction while it helps relieving the internal stress during lithium insertion and extraction. This study provides insight on fabricating patterned carbon architecture by rational design for enhanced electrochemical performance

  8. Enhanced lithium ion storage in nanoimprinted carbon

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peiqi; Chen, Qian Nataly; Li, Jiangyu, E-mail: jjli@uw.edu [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195-2600 (United States); Xie, Shuhong [Faculty of Materials, Optoelectronics and Physics, and Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan University, Xiangtan 411105, Hunan (China); Liu, Xiaoyan [College of Metallurgy and Materials Engineering, and Advanced Materials for Energy Institute, Chongqing University of Science and Technology, Chongqing 401331 (China)

    2015-07-27

    Disordered carbons processed from polymers have much higher theoretical capacity as lithium ion battery anode than graphite, but they suffer from large irreversible capacity loss and have poor cyclic performance. Here, a simple process to obtain patterned carbon structure from polyvinylpyrrolidone was demonstrated, combining nanoimprint lithography for patterning and three-step heat treatment process for carbonization. The patterned carbon, without any additional binders or conductive fillers, shows remarkably improved cycling performance as Li-ion battery anode, twice as high as the theoretical value of graphite at 98 cycles. Localized electrochemical strain microscopy reveals the enhanced lithium ion activity at the nanoscale, and the control experiments suggest that the enhancement largely originates from the patterned structure, which improves surface reaction while it helps relieving the internal stress during lithium insertion and extraction. This study provides insight on fabricating patterned carbon architecture by rational design for enhanced electrochemical performance.

  9. 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.

  10. Structural disorder in ion irradiated carbon materials

    International Nuclear Information System (INIS)

    The effects of ion irradiation on carbon based materials are reviewed laying emphasis on the well known ability of carbon to have different kinds of bonding configuration with the surrounding atoms. It was found that two kinds of bonding configuration of the carbon atoms are allowed in solid amorphous carbon phases. These rearrange the four valence electrons of carbon into sp2 (trigonal bond) and sp3 (tetrahedral bond) hybridizations. Driving the trigonal carbon fraction (x), the physical and chemical nature of solid carbon materials can change in a dramatic way ranging from metallic (x∼100%) to insulating (x∼0%) through semiconductor properties. The amount of the tetrahedral (or trigonal) carbon atoms can be controlled by ion beam irradiation, using suitable conditions and/or introducing foreign species such as hydrogen or silicon by the implantation technique. In hydrogenated amorphous carbon (a-C:H) and hydrogenated amorphous silicon-carbon alloys (a-Si1-xCx:H), the ion beam effects are able to produce stable and reproducible compounds, achieved by tuning the hydrogen (silicon) concentration with well defined equilibrium curves between the trigonal carbon fraction and hydrogen (silicon) content. Raman spectroscopy and temperature dependent conductivity experiments performed on these alloys suggest clustering effects in samples with high carbon content (x∼0.5) due to the strong binding energy of the C-C double bond with respect to C-Si and Si-Si. Several models and theoretical studies such as the 'random covalent network' (RCN) and molecular dynamics calculations have been used to fit the experimental results. It is shown that, while RCN models are highly inaccurate because of the clustering effects, molecular dynamics calculation data are very close to the experimental measured physical properties and confirm the ability of the trigonal carbon to cluster in graphite-like aggregate

  11. 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

  12. F values for isoelectronic ions of carbon

    Science.gov (United States)

    Ganas, P. S.

    1981-10-01

    An analytic atomic independent particle model is used to generate wave functions for the valence and excited states of isoelectronic ions of carbon up to Z = 20. Using these wave functions in conjunction with the Born approximation and the Russell-Saunders LS-coupling scheme, f values are calculated for various transitions from the 2p2(3P0) ground state. The results are compared with those from other works.

  13. Recent innovations in carbon-ion radiotherapy

    International Nuclear Information System (INIS)

    In the last few years, hospital-based facilities for carbon-ion radiotherapy are being constructed and proposed in Europe and Asia. During the next few years, several new facilities will be opened for carbon-ion radiotherapy in the world. These facilities in operation or under construction are categorized in two types by the beam shaping method used. One is the passive beam shaping method that is mainly improved and systematized for routine clinical use at Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. The other method is active beam shaping which is also known as beam scanning adopted at Gesellschaft fur Schwerionenforschung (GSI)/Heidelberg Ion Therapy Center (HIT), Germany. In this paper an overview of some technical aspects for beam shaping is reported. The technique of passive beam shaping is established for stable clinical application and has clinical result of over 4000 patients in HIMAC. In contrast, clinical experience of active beam shaping is about 400 patients, and there is no clinical experience to respiratory moving target. A great advantage of the active beam shaping method is patient-specific collimator-less and compensator-less treatment. This may be an interesting potential for adaptive radiotherapy. (author)

  14. Treatment planning system for carbon ion radiotherapy

    International Nuclear Information System (INIS)

    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)

  15. 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.)

  16. Carbonate ions and arsenic dissolution by groundwater

    Science.gov (United States)

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

    2000-01-01

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

  17. 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.

  18. Carbon ion radiotherapy of skull base chondrosarcomas

    International Nuclear Information System (INIS)

    Purpose: To evaluate the effectiveness and toxicity of carbon ion radiotherapy in chondrosarcomas of the skull base. Patients and Methods: Between November 1998 and September 2005, 54 patients with low-grade and intermediate-grade chondrosarcomas of the skull base have been treated with carbon ion radiation therapy (RT) using the raster scan technique at the Gesellschaft fuer Schwerionenforschung in Darmstadt, Germany. All patients had gross residual tumors after surgery. Median total dose was 60 CGE (weekly fractionation 7 x 3.0 CGE). All patients were followed prospectively in regular intervals after treatment. Local control and overall survival rates were calculated using the Kaplan-Meier method. Toxicity was assessed according to the Common Terminology Criteria (CTCAE v.3.0) and Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) score. Results: Median follow-up was 33 months (range, 3-84 months). Only 2 patients developed local recurrences. The actuarial local control rates were 96.2% and 89.8% at 3 and 4 years; overall survival was 98.2%at 5 years. Only 1 patient developed a mucositis CTCAE Grade 3; the remaining patients did not develop any acute toxicities >CTCAE Grade 2. Five patients developed minor late toxicities (RTOG/EORTC Grades 1-2), including bilateral cataract (n = 1), sensory hearing loss (n = 1), a reduction of growth hormone (n = 1), and asymptomatic radiation-induced white matter changes of the adjacent temporal lobe (n = 2). Grade 3 late toxicity occurred in 1 patient (1.9%) only. Conclusions: Carbon ion RT is an effective treatment for low- and intermediate-grade chondrosarcomas of the skull base offering high local control rates with low toxicity

  19. Carbon ion radiotherapy for uveal melanoma

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the applicability of carbon ion beams in the treatment of choroidal melanoma, with regard to normal tissue morbidity and local tumor control. Between January 2001 and August 2006, 67 patients with locally advanced or unfavorable-site choroidal melanoma were enrolled in a phase I/II clinical trial of carbon-ion radiotherapy (C-ion RT) at the National Institute of Radiological Sciences (NIRS). Primary endpoint of this study was normal tissue morbidity and secondary endpoints were local tumor control and patient survival. Fifty-nine of the patients were followed up for more than 6 months and analyzed. Twenty-three patients (39%) developed neovascular glaucoma (NVG) and 3 of them underwent enucleation because of the eye pain due to elevated intraocular pressure. The incidence of neovascular glaucoma was dependent on tumor size and site. Five patients had died by the date of analysis, 3 of distant metastasis and 2 of intercurrent diseases. All patients but one, who developed marginal recurrence, were controlled locally. Eight patients developed distant metastasis, 5 in the liver and 3 in the lung. Three-year overall survival, disease-free survival, and local control rates were 87.1%, 81.6%, and 98.0%, respectively. No apparent dose-response relationship was observed either in tumor control or in normal tissue morbidity with the dose range applied. C-ion RT can be applied to choroidal melanoma with an acceptable morbidity and sufficient anti-tumor effect, even in tumors of unfavorable size or site. (author)

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. Damage to plasmid DNA induced by low energy carbon ions

    International Nuclear Information System (INIS)

    The damage induced in supercoiled plasmid DNA molecules by 1-6 keV carbon ions has been investigated as a function of ion exposure, energy and charge state. The production of short linear fragments through multiple double strand breaks has been demonstrated and exponential exposure responses for each of the topoisomers have been found. The cross section for the loss of supercoiling was calculated to be (2.2 ± 0.5) x 10-14 cm2 for 2 keV C+ ions. For singly charged carbon ions, increased damage was observed with increasing ion energy. In the case of 2 keV doubly charged ions, the damage was greater than for singly charged ions of the same energy. These observations demonstrate that ion induced damage is a function of both the kinetic and potential energies of the ion

  9. 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.

  10. 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.

  11. 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

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

    Science.gov (United States)

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

    2015-08-01

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

  13. 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.

  14. 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.

  15. 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...

  16. 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)

  17. 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.

  18. 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

  19. Separation of Carbon Dioxide from Flue Gas Using Ion Pumping

    Energy Technology Data Exchange (ETDEWEB)

    Aines, R; Bourcier, W L; Johnson, M R

    2006-04-21

    We are developing a new way of separating carbon dioxide from flue gas based on ionic pumping of carbonate ions dissolved in water. Instead of relying on large temperature or pressure changes to remove carbon dioxide from solvent used to absorb it from flue gas, the ion pump increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, which can be removed from the downstream side of the ion pump as a nearly pure gas. This novel approach to increasing the concentration of the extracted gas permits new approaches to treating flue gas. The slightly basic water used as the extraction medium is impervious to trace acid gases that destroy existing solvents, and no pre-separation is necessary. The simple, robust nature of the process lends itself to small separation plants. Although the energy cost of the ion pump is significant, we anticipate that it will be compete favorably with the current 35% energy penalty of chemical stripping systems in use at power plants. There is the distinct possibility that this simple method could be significantly more efficient than existing processes.

  20. 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.

  1. Fabrication of carbon nanostructures (nanodots, nanowires) by energetic ion irradiation

    International Nuclear Information System (INIS)

    Carbon nanostructures were synthesized by energetic ion irradiation of Si-based gel films. These polymer-like films with different side groups and C concentrations were prepared by sol-gel chemistry and irradiated with Si or Au ions of different energies in the range 3 MeV-2 GeV. The shape and size of the formed carbon nanostructures was studied by energy filtered transmission electron microscopy. They exhibited a visible photoluminescence emission, due to their semiconducting nature and the confinement of excitons. The changes in the optical properties were correlated with the structural transformation of films, investigated by means of Fourier transformed infrared (FTIR) and Raman spectroscopies. The role of carbon concentration, structure and energy transferred by ions on the luminescence properties are discussed

  2. 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)

  3. 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.

  4. 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...

  5. On influence of irradiation by carbon ions on tantalum structure

    International Nuclear Information System (INIS)

    Data of experimental studies on tantalum surface structure change and it microhardness in the result of carbon ion implantation are presented. The tantalum samples with purity 99.96 % having cylindrical shape (height 55 mm and diameter 4.5-5 mm) after polish were irradiated by carbon ions with energy 60 keV in the range 5·1016-5·1018 cm-2 at the DIANA facility. The microhardness measurement has been conducted on the PMT-3 device on the irradiated surface and along samples cross section. The microstructure has been examined on the NEOFOT-21 optical microscope, and phase-structural transformations were studied on the 3.0 DRON X-ray diffractometer with application of CuKα radiation. It is determined, that under carbon ion implantation into tantalum surface layers the texture tantalum carbide phases and tantalum monocarbide arise. Post-radiation thermal annealing leads to tantalum monocarbide decay and tantalum carbide particle sizes increase. It is determined, that phases got under C+ implantation have introduction phase structure with dense atom packing. Ion doping leads to tantalum surface hardening. Hardening rate depends on the irradiation fluence. Maximal hardening has been observed on the surface, the maximal microhardness increase extension along whole samples thickness. Due to carbon ions implantation the microhardness is increasing in 3 times near surface, and up to 1.5-3 times over samples thickness

  6. Conducting carbon nanopatterns (nanowire) by energetic ion irradiation

    International Nuclear Information System (INIS)

    This work reports the formation of conducting carbon nanopatterns (nano-wires) in a semi-inorganic polymer by irradiation with energetic ions. The conducting nano-patterns/wires are evidenced by conducting atomic force microscopy. The typical diameter of the conducting wires is observed to be about ∼50-200 nm. The density (spacing), growth direction and length of these carbon nanowires can be changed simply by ion fluence, angle of irradiation and the film thickness, respectively. The formation of conducting nanopatterns in an insulating matrix (polymers/gels) is correlated with the structural transformation of films, investigated by means of Raman spectroscopy

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

    International Nuclear Information System (INIS)

    Full text: Carbon nitride films have been deposited on Si (100) by ion beam sputtering a vitreous graphite target with nitrogen and argon ions with and without concurrent N2 ion bombardment at room temperature. The sputtering beam energy was 1000 eV and the assisted beam energy was 300 eV with ion / atom arrival ratio ranging from 0.5 to 5. The carbon nitride films were deposited both as single layer directly on silicon substrate and as multilayer between two layers of stoichiometric amorphous silicon nitride and polycrystalline titanium nitride. The deposited films were implanted ex-situ with 30 keV nitrogen ions with various doses ranging from 1E17 to 4E17 ions.cm-2 and 2 GeV xenon ion with a dose of 1E12 ions.cm-2 . The nitrogen concentration of the films was measured with Rutherford Backscattering (RBS), Secondary Neutral Mass Spectrometry (SNMS) and Parallel Electron Energy Loss Spectroscopy (PEELS). The nitrogen concentration for as deposited sample was 34 at% and stoichiometric carbon nitride C3N4 was achieved by post nitrogen implantation of the multi-layered films. Post bombardment of single layer carbon nitride films lead to reduction in the total nitrogen concentration. Carbon K edge structure obtained from PEELS analysis suggested that the amorphous C3N4 matrix was predominantly sp2 bonded. This was confirmed by Fourier Transforrn Infra-Red Spectroscopy (FTIR) analysis of the single CN layer which showed the nitrogen was mostly bonded with carbon in nitrile (C≡N) and imine (C=N) groups. The microstructure of the film was determined by Transmission Electron Microscopy (TEM) which indicated that the films were amorphous

  8. Mutagenic effects of nitrogen and carbon ions on stevia

    International Nuclear Information System (INIS)

    Dry seeds of stevia were implanted by 60∼100 keV nitrogen ion and 75 keV carbon ion with various doses. The biological effects in M1 and mutation in M2 were studied. The results showed that ion beam was able to induce variation on chromosome structure and inhibited mitosis action in root tip cells. The rate of cells with chromosome aberration was increased with the increase of ion beam energy and dose. Energy effects of mitosis were presented between 75 keV and 60, 100 keV. As compared with γ-rays, the effects of ion beam were lower on chromosomal aberration but were higher on frequency of the mutation. The rate of cell with chromosome aberration and M2 useful mutation induced by implantation of carbon ion was higher than those induced by implantation of nitrogen ion. Mutagenic effects of Feng1 x Ri Yuan and of Ri Yuan x Feng2 are higher than that of Ji Ning and Feng2

  9. Gunma University Heavy Ion Medical Center. Evolution of carbon therapy

    International Nuclear Information System (INIS)

    Cancer treatments with high energy carbon beams have been initiated at Gunma University Heavy Ion Medical Center, GHMC, in March of this year. Aiming the wide spread of the carbon therapy, the grand design of the facility and a variety of R and D studies were conducted by HIMAC group of National Institute of Radiological Sciences, NIRS, in collaboration with Gunma University. The design concepts of the facility include the high reliability, high efficiency, and low construction and operation cost. The success of the facility will open up new era of the carbon therapy. (author)

  10. Processing of diamondlike carbon using plasma immersion ion deposition

    International Nuclear Information System (INIS)

    Plasma immersion ion deposition (PIID) has been used to synthesize hard amorphous hydrogenated carbon or diamondlike carbon (DLC) thin films on Si substrates with rf inductive plasmas of various Ar and C2H2 gas mixtures. The surface hardness and stress of the films were highly dependent on the magnitude of the total rf power and the pulse-bias duty factor. The ratios of the ion flux and the film deposition flux, Ji/Jd, were estimated and correlated with DLC film stress, hardness, and the amount of argon and hydrogen content retained. The DLC properties (hardness and film stress) were maximal when the Ji/Jd value ranged between 0.6 and 0.8. The balance between ion-energy transfer and relaxation in the surface and subsurface carbon atoms may explain the DLC growth in this work. The role of ion-current flux in the PIID process was found to be as important as it is in conventional ion beam assisted deposition processing. copyright 1999 American Vacuum Society

  11. 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.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    Purpose: The dose response of the alanine detector shows a dependence on particle energy and type, when irradiated with ion beams. The purpose of this study is to investigate the response behaviour of the alanine detector in clinical carbon ion beams and compare the results with model predictions....... Methods: Alanine detectors have been irradiated with carbon ions with an energy range of 89-400 MeV/u. The relative effectiveness of alanine has been measured in this regime. Pristine and spread out Bragg peak depth-dose curves have been measured with alanine dosimeters. The track-structure based alanine...... response model developed by J. Hansen and K. Olsen has been implemented in the Monte Carlo code FLUKA, and calculations were compared with experimental results. Results: Calculations of the relative effectiveness deviate less than 5% from the measured values for mono energetic beams. Measured depth...

  13. 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

  14. Investigation of physiologically active products obtained from carbon-ion irradiated actinomycetes

    International Nuclear Information System (INIS)

    Charged particles such as carbon-ions are superior to X-rays or gamma-rays in the physical and biological characteristics. The propose research project is aimed to provide new insights on antibiotic development. Carbon-ion exposure reduced cell growth. Product(s) from carbon-ion irradiated microorganera suppressed growth of human leukemia cells. We suggested that carbon-ion irradiated actinomycetes produce antitumor active product(s) for leukemia cells. (author)

  15. Modification of diamond-like carbon by ion irradiation

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) films were irradiated with swift heavy ion beams of varying energy and angles of incidence. The irradiation created electrically conducting tracks in the DLC-films by transforming sp3 into sp2 bonds. The DLC-films were analyzed by conductive atomic force microscopy. The images were used to identify ion impact sites, and I-V-Spectroscopy was applied to determine the conductivity of the tracks. High energy ions (2.2 GeV, Au25+) created tracks with ohmic conductivity in the case of perpendicular bombardment, whereas grazing irradiation results in tracks that show mainly tunneling behavior. Low energy ions (100 MeV, Xe23+) created tracks which exhibit tunneling behaviour after perpendicular incidence irradiation, but irradiation under 1 did not result in conductive tracks.

  16. 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 ...

  17. 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.

  18. 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.

  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 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.

  20. 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

  1. 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

  2. Coprecipitation of alkali metal ions with calcium carbonate

    International Nuclear Information System (INIS)

    The coprecipitation of alkali metal ions Li+, Na+, K+ and Rb+ with calcium carbonate has been studied experimentally and the following results have been obtained: (1) Alkali metal ions are more easily coprecipitated with aragonite than with calcite. (2) The relationship between the amounts of alkali metal ions coprecipitated with aragonite and their ionic radii shows a parabolic curve with a peak located at Na+ which has approximately the same ionic radius as Ca2+. (3) However, the amounts of alkali metal ions coprecipitated with calcite decrease with increasing ionic radius of alkali metals. (4) Our results support the hypothesis that (a) alkali metals are in interstitial positions in the crystal structure of calcite and do not substitute for Ca2+ in the lattice, but (b) in aragonite, alkali metals substitute for Ca2+ in the crystal structure. (5) Magnesium ions in the parent solution increase the amounts of alkali metal ions (Li+, Na+, K+ and Rb+) coprecipitated with calcite but decrease those with aragonite. (6) Sodium-bearing aragonite decreases the incorporation of other alkali metal ions (Li+, K+ and Rb+) into the aragonite. (author)

  3. Pore-size ion-size correlations for carbon supercapacitors

    Science.gov (United States)

    Chmiola, John

    2009-08-01

    Carbon supercapacitors, which are energy storage devices that use ion adsorption on the surface of highly porous materials to store charge, have numerous advantages over other power-source technologies, but could realize further gains if their electrodes were properly optimized. This could lead to fleet-wide improvements in economy, performance, lifetime and environmental impact of Hybrid Electric Vehicles (HEVs), as well as enable or advance many other applications. To determine correlations between ion-size and pore-size in carbon supercapacitors, we generated a well-characterized set of porous carbide-derived carbons (CDC) with average pore sizes from 0.6 to 2.25 nm and used them to probe the limits of understanding. Performing the first systematic study of the effect of pore size on capacitance showed that, in general, decreasing the pore size below the size of the solvated ion, or to precisely the size of the ionic liquid ion, allowed higher accumulation of charge. Using CDC with properly tuned porosity showed excellent performance in H2SO 4, ˜200 F/g, and performance superior to all prior reported results in organic (CH3CH2)4NBF4 (TEABF 4) electrolytes as well as l-ethyl-3-methyl immidazolium bis-(trifluoromethanesulfonyl)imide (EMI-TFSI) ionic liquid, ˜150 F/g. This work conclusively showed that precisely matching the pore size with the ion size is the key factor for maximizing capacitance. Understanding that pores significantly larger than the effective ion size do not have large contributions to energy storage, work on dense porous CDC films on conductive substrates showed ˜100% larger volumetric capacitance than any previously reported. Depositing patterned films of carbide and electrical contacts could lead to microfabricated energy storage devices directly on a chip, or built up in layers for performances yet unrealized.

  4. Dual ion beam deposition of carbon films with diamondlike properties

    Science.gov (United States)

    Mirtich, M. J.; Swec, D. M.; Angus, J. C.

    1984-01-01

    A single and dual ion beam system was used to generate amorphous carbon films with diamond like properties. A methane/argon mixture at a molar ratio of 0.28 was ionized in the low pressure discharge chamber of a 30-cm-diameter ion source. A second ion source, 8 cm in diameter was used to direct a beam of 600 eV Argon ions on the substrates (fused silica or silicon) while the deposition from the 30-cm ion source was taking place. Nuclear reaction and combustion analysis indicate H/C ratios for the films to be 1.00. This high value of H/C, it is felt, allowed the films to have good transmittance. The films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Although the measured density of the films was approximately 1.8 gm/cu cm, a value lower than diamond, the films exhibited other properties that were relatively close to diamond. These films were compared with diamondlike films generated by sputtering a graphite target.

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

    Science.gov (United States)

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

    2010-02-01

    In many experiments methods were applied to increase the highly charged ion output from an electron cyclotron resonance ion source; the gas-mixing method is still generally being applied. The dominant role of the masses of the ions in the gas-mixture was apparent. Two basically differing mechanisms could to first order explain most of the observations. A significant mass effect showed up in a mixture of oxygen isotopes, the so-called oxygen anomaly; so far that effect could be explained in zeroth order only. The anomaly was observed later for nitrogen isotopes as well. In the present experiment it is shown that the anomaly also exists for carbon isotopes, where the necessity of feeding the source with carbon-hydrogen compounds brings about an essential different experimental fact. PMID:20192439

  6. The temperature and carbonate ion influence on Pleistocene high latitude planktonic foraminiferal carbon isotopic records

    Science.gov (United States)

    Charles, C.; Foreman, A. D.; Munson, J.; Slowey, N. C.; Hodell, D. A.

    2014-12-01

    Establishing a credible record of the carbon isotopic composition of high latitude surface ocean DIC over ice ages has been an enormous challenge, because the possible archives of this important variable in deep sea sediments all incorporate complex effects of the biomineralization process. For example, culture experiments (by Spero and colleagues) demonstrate a strong temperature and carbonate ion effect on the carbon isotopic composition of G. bulloides--the taxon of planktonic foraminifera that is most abundant in the majority of subpolar sediment sequences. Here we capitalize on the fortuitous observation of exceptionally strong covariation between the oxygen and carbon isotopic composition of G. bulloides in multiple sediment sequences from the Benguela upwelling region. The covariation is most clear during Marine Isotopic Stage 3 (an interval when the isotopic composition of the seawater was least variable) and undoubtedly results from the precipitation of tests under variable conditions of temperature and carbonate ion. The unusually clear isotopic relationship in planktonic foraminifera observed off Namibia constitutes a field calibration of the biomineralization effects observed in culture, and we apply it to previously published high latitude carbon isotopic records throughout the Southern Ocean. We find that many of the excursions toward lower planktonic foraminiferal δ13C that have been interpreted previously as the upwelling of nutrient rich water during deglaciations are better explained as increases in upper ocean temperature and carbonate ion. Conversely, the excursions toward high δ13C during ice age intervals that have been interpreted previously as increased export production (purportedly stimulated by dust) are also better explained by temperature and carbonate ion variability. After removal of the inferred temperature and carbonate ion signal from the planktonic foraminiferal time series, the residual is essentially (but not exactly) the same

  7. Carbon ion radiotherapy. Clinical study and future prospect

    International Nuclear Information System (INIS)

    At present, most of the patients receiving carbon ion radiotherapy at National Institute of Radiological Sciences (NIRS) visit the clinic seeking this specific modality, and it is difficult to obtain consent for a randomized controlled study from these patients and it may be unnecessary to conduct a phase III trial. However, in selected tumors where the high-linear energy transfer (LET) benefit could be appreciated, we can participate in randomized studies. Finally, studies aimed at clarifying the usefulness of carbon ion radiotherapy and elucidating any advantages from hypo-fractionation should be considered. A multi-institutional prospective non-randomized concurrent phase II clinical trial is one such new approach, and it will be proposed not only to the Japanese, but also to the international community of particle therapy and radiation oncology. (author)

  8. 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$^{-1}$.

  9. 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...

  10. 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.

  11. 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.)

  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. 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

  14. 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.

  15. 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.

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

    Science.gov (United States)

    2016-01-01

    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 sp3 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.

  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. Production of defects in supported carbon nanotubes under ion irradiation

    International Nuclear Information System (INIS)

    Ion irradiation of individual carbon nanotubes deposited on substrates may be used for making metallic nanowires and studying effects of disorder on the electronic transport in low-dimensional systems. In order to understand the basic physical mechanisms of radiation damage production in supported nanotubes, we employ molecular dynamics and simulate ion impacts on nanotubes lying on different substrates, such as platinum and graphite. We show that defect production depends on the type of the substrate and that the damage is higher for metallic heavy-atom substrates than for light-atom substrates, since in the former case sputtered metal atoms and backscattered recoils produce extra damage in the nanotube. We further study the behavior of defects upon high-temperature annealing and demonstrate that although ions may severely damage nanotubes in a local region, the nanotube carbon network can heal such a strong localized damage due to defect migration and dangling-bond saturation. We also show that after annealing the residual damage in nanotubes is independent of the substrate type. We predict the pinning of nanotubes to substrates through nanotube-substrate bonds that appear near irradiation-induced defects

  19. Ion solvation in propylene carbonate and its mixtures with water and methanol

    International Nuclear Information System (INIS)

    Solvodynamic radii and solvation numbers of some ions (including I-) in propylene carbonate as well as their solvodynamic radii in mixtures of propylene carbonate-water and propylene carbonate-methanol were determined. Effect of medium components and solvated ion characteristics on the process of ion solvation was considered. It is shown that small size anions in propylene carbonate are weakly solvated, whereas bulky lightly polarized anions interact strongly with the solvent. Addition of water or methanol to propylene carbonate leads to intensification of ion solvation

  20. Carbon-cluster formation from polymers caused by MeV-ion impacts and keV-cluster-ion impacts

    Science.gov (United States)

    Diehnelt, C. W.; van Stipdonk, M. J.; Schweikert, E. A.

    1999-06-01

    It has been observed that under MeV-ion bombardment of a polymer, such as polycarbonate (PC) or polyvinylidene fluoride (PVDF), large quantities of carbon clusters (C-n and CnH-) are generated. However, when PC or PVDF is bombarded with keV atomic ions, very few carbon-cluster ions are produced. This different behavior was attributed to the different sputtering/desorption mechanisms for keV- and MeV-ion impacts. Low-energy keV ions deposit their energy into a solid through nuclear stopping, while MeV ions deposit their energy mainly through electronic stopping. The formation of carbon clusters is thought to be facilitated by the high-temperatures and high-energy densities produced in the region nearest the point of MeV-ion impact, the infratrack region. We have observed extensive carbon-cluster formation from PC and PVDF under keV-cluster-ion bombardment. Despite the vastly different velocities of the high- and low-energy projectiles, identical carbon-cluster trends are produced from MeV 252Cf fission fragments and 20-keV C+60 projectile impacts on the same target. This leads us to the conclusion that a polyatomic ion impact, which deposits its kinetic energy near the surface, may create a region of high-temperature and high-energy density that is similar to the infratrack of a MeV-ion impact.

  1. 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

  2. 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.

  3. 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.)

  4. 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

  5. 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

  6. EUD-based biological optimization for carbon ion therapy

    International Nuclear Information System (INIS)

    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

  7. 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

  8. 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...

  9. 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.

  10. Complexation of europium(III) with carbonate ions in groundwater

    International Nuclear Information System (INIS)

    The equilibrium extraction behavior of Eu(III) studied in chloroform solutions containing 1-nitroso-2-naphthol (HA), either alone or combined with 2,2'-dipyridyl, 1,10-phenanthroline (phen), or trioctylphosphine oxide (TOPO) shows that the metal ion is extracted as either EuA3, EuA3.2,2'-dipyridyl, EuA3.phen, or EuA32TOPO, respectively. The synergic effect of phen or TOPO on the extraction of EU(III) with 1-nitrose-2-naphthol is more pronounced over that of 2,2'-dipyridyl. The carbonate complexation of EU(III) has been studied in 1.0 M ionic strength solutions at pH 8.0-9.0 and 250C using the synergic extraction system of 1-nitroso-2-naphthol and phen. The following complexes have been identified: EuCo+3, Eu(CO3)-2, Eu(CO3)3-3, and Eu(CO3)5-4; the results suggest that the first two species predominate at carbonate concentrations and pH similar to those found in most groundwaters. The formation constants of these species have been calculated at zero ionic strength using both SIT and ion pairing models

  11. Irradiation with carbon ions for locally recurrent rectal cancer

    International Nuclear Information System (INIS)

    A female patient in her 70s underwent an abdominoperineal resection and bilateral lymph node dissection for advanced lower rectal cancer. The patient did not receive neoadjuvant therapy. In the Japanese classification of colorectal carcinoma (8th Edition), the tumor was a moderately differentiated type 2 adenocarcinoma, and was 4.5 cm in size. Histologically, the tumor was considered to be Stage 3b (T3N0M0). She received no adjuvant chemotherapy. After 39 months, pelvic computed tomography (CT) revealed a 29 mm tumor in the right pelvic wall. The patient declined surgery for recurrence so radiotherapy was planned. First, chemotherapy with mFOLFOX6 was administered for 4 courses to reduce tumor size. Consequently, irradiation with carbon ions was given to the site of recurrence at a total dose of 74 GyE in 37 fractions. There were no severe complications. Carcinoembryonic antigen (CEA) level decreased to the lower limit of the normal range from a maximum of 4.9, and no progression of the recurrent tumor was detected on CT for approximately 4 years. Systemic chemotherapy followed by irradiation with carbon ions may be effective for recurrent rectal cancer. (author)

  12. Mass spectrometry of refractory black carbon particles from six sources: carbon-cluster and oxygenated ions

    Directory of Open Access Journals (Sweden)

    J. C. Corbin

    2013-10-01

    Full Text Available We discuss the major mass spectral features of different types of refractory carbonaceous particles, ionized after laser vapourization with an Aerodyne High-Resolution Soot-Particle Aerosol Mass Spectrometer (SP-AMS. The SP-AMS was operated with a switchable 1064 nm laser and a 600 °C thermal vapourizer, yielding respective measurements of the refractory and non-refractory particle components. Six samples were investigated, all of which were composed primarily of refractory material: fuel-rich and fuel-lean propane/air diffusion-flame combustion particles; graphite-spark-generated particles; a commercial Fullerene-enriched Soot; Regal Black, a commercial carbon black; and nascent aircraft-turbine combustion particles. All samples exhibited a spectrum of carbon-cluster ions Cxn+ in their refractory mass spectrum. Smaller clusters (xxn+ distribution. For Fullerene Soot, fuel-rich-flame particles and spark-generated particles, significant Cxn+ clusters at x≫6 were present, with significant contributions from multiply-charged ions (n>1. In all six cases, the ions C1+ and C3+ contributed over 60% to the total C1x+ intensity. Furthermore, the ratio of these major ions C1+/C3+ could be used to predict whether significant Cxn+ signals with x>5 were present. When such signals were present, C1+/C3+ was close to 1. When absent, C1+/C3+ was Significant refractory oxygenated ions such as CO+ and CO2+ were also observed for all samples. We discuss these signals in detail for Regal Black, and describe their formation via decomposition of oxygenated moieties incorporated into the refractory carbon structure. These species may be of importance in atmospheric processes such as water uptake, aging and heterogeneous chemistry.

  13. Nanodosimetric descriptors of the radiation quality of carbon ions

    International Nuclear Information System (INIS)

    In view of the emerging interest of carbon ions in radiotherapy and of the strong correlation between the track structure and the radiobiological effectiveness of ionising radiations, the track-structure properties of 12C-ions were studied at particle energies close to the Bragg peak. To perform the investigations, ionisation-cluster-size distributions for nanometre-sized target volumes were measured with the track-nano-dosimeter installed at the TANDEM-ALPI accelerator complex at LNL, and calculated using a dedicated Monte Carlo simulation code. The resulting cluster-size distributions are used to derive particular descriptors of particle track structure. Here, the main emphasis is laid on the mean ionisation-cluster size M1 and the cumulative probability Fk of measuring cluster sizes ν≥k. From the radiobiological point of view, Fk is of particular interest because an increasing k corresponds to an increase of damages of higher complexity. In addition, Fk saturates with increasing radiation quality like radiobiological cross sections as a function of linear energy transfer. Results will be presented and discussed for 12C-ions at 96 and 240 MeV. (authors)

  14. Exploration of using CT values for treatment planning system to calculate the carbon ion incident energy

    International Nuclear Information System (INIS)

    Objective: To explore the methods of using CT value for Carbon ion treatment planning system to calculate the Carbon ion incident energy. Methods: Bethe-Block formula and the formula for calculating the Car- bon ion range were analyzed to study the relationship of the range of Carbon ion beam (Single nuclear energy 80 MeV -50 MeV) in a variety of radiation equivalent material and the range of this energy Carbon ion beam in water. Procedure of Monte Carlo SRIM 2008 was used to verify the possibility of a constant range of proportional coefficient (Ci). The range of proportional coefficient (Ci) of radiation equivalent material and the CT value were fitted through Origin 8.0 software to study the of CT value and the range of proportional coefficient (Ci). The actual range of Carbon ion is equivalent to a range of water to incident Carbon ion energy. Results: There is a constant range of proportional coefficient (Ci) of the range of Carbon ion beam (Single nuclear energy 80 MeV ∼50 MeV) in a variety of radiation equivalent material and the range of this energy Carbon ion beam in water. There is a of CT value and the range of proportional coefficient (Ci) (r=0.999). The actual range of Carbon ion in radiation equivalent material can be equivalent to a range of the water. Conclusion: In this study, using CT values and a range of proportional coefficient (Ci), the actual required range of the tumor can accurately calculate the water equivalent range, and incident Carbon ion energy to the of Bragg peak. By the study, a new exploration for using CT technology, for Carbon ion treatment planning system was obtained. (authors)

  15. Clinical trial of carbon ion radiotherapy for gynecological melanoma

    International Nuclear Information System (INIS)

    Carbon ion radiotherapy (C-ion RT) is an advanced modality for treating malignant melanoma. After we treated our first case of gynecological melanoma using C-ion RT in November 2004, we decided to conduct a clinical trial to evaluate its usefulness for the treatment of gynecological melanoma. The eligibility criteria for enrollment in this study were histologically proven malignant melanoma of the gynecological regions with lymph node metastasis remaining in the inguinal and pelvic regions. The small pelvic space, including the GTV and the metastatic lymph node, was irradiated with up to a total dose of 36 GyE followed by a GTV boost of up to a total dose of 57.6 GyE or 64 GyE in 16 fractions. A series of 23 patients were treated between November 2004 and October 2012. Patient age ranged from 51-80 with a median of 71. Of the tumor sites, 14 were located in the vagina, 6 in the vulva, and 3 in the cervix uteri. Of the 23 patients, 22 were irradiated with up to a total dose of 57.6 GyE, and 1 patient was irradiated with up to a total dose of 64 GyE. Chemotherapy and interferon-β were also used to treat 11 of the patients. Acute and late toxicities of Grade 3 or higher were observed in 1 patient treated with concurrent interferon-β. The median follow-up time was 17 months (range, 6-53 months). There was recurrence in 14 patients, and the 3-year local control and overall survival rates were 49.9% and 53.0%, respectively. C-ion RT may become a non-invasive treatment option for gynecological melanoma. (author)

  16. Ion Transport Characteristics of Individual Single-walled Carbon Nanotubes Mimic Those of Biological Ion Channels

    Science.gov (United States)

    Amiri, Hasti; Shepard, Kenneth; Nuckolls, Colin

    2014-03-01

    Transmembrane ionic channels play a crucial role in vital cellular activities by regulating the transport of ions and fluid across the cell membrane. Their structural complexity and flexibility as well as their many unique operational features, however, make their investigation extremely difficult. The simple, atomically smooth and well-defined structure of carbon nanotubes (CNTs) provides an excellent template for studying molecular transport at nanoscale. Additionally, CNTs have been suggested as analogues to biological pores since they share several common features such as nanometer size diameter, hydrophobic core and ultrafast water flow. Functionalizing the nanotube entrance can also mimic the selectivity filter of ion channels. In this work, we experimentally study ionic transport through individual single-walled CNTs connecting two fluid reservoirs as a function of pore properties and electrolyte type and concentration. We provide strong evidence that the electrostatic potentials arising from the ionized carboxyl groups at the pore entrance significantly influence the ion permeation in a manner consistent with a simple electrostatic mechanism. Lastly, the similarities of ionic transport mechanisms between individual single-walled CNTs and protein ion channels are discussed.

  17. Optical properties of ion-beam-deposited ion-modified diamondlike (a-C:H) carbon

    International Nuclear Information System (INIS)

    Diamondlike carbon (DLC) is a hard, semitransparent material usually containing varying amounts of hydrogen. These materials have numerous potential applications, including use as coatings for infrared optics, and as such, the effects of damaging irradiation is of practical interest. In this paper we present results of variable angle spectroscopic ellipsometric (VASE) studies of ion-beam-deposited DLC films. These films have been further modified by directing 1-MeV gold ions, as well as 6.4-MeV fluorine ions, through the DLC and into the underlying silicon substrates, and the percentage of hydrogen in the film was measured versus fluence using proton recoil analysis. Optical analysis was performed assuming the Lorentz oscillator model. Three versions were used: one oscillator, two oscillator (with one fixed in energy), and two oscillator with all parameter variable. The latter model fits the VASE data extremely well, and the two oscillators can be interpreted as involving π to π* and σ to σ* band transitions. With ion modification the oscillators shift to lower photon energy, consistent with reduction in hydrogen concentration and possible increased graphitization

  18. Clinical Outcome of Sacral Chordoma With Carbon Ion Radiotherapy Compared With Surgery

    International Nuclear Information System (INIS)

    Purpose: To evaluate the efficacy, post-treatment function, toxicity, and complications of carbon ion radiotherapy (RT) for sacral chordoma compared with surgery. Methods and Materials: The records of 17 primary sacral chordoma patients treated since 1990 with surgery (n = 10) or carbon ion RT (n = 7) were retrospectively analyzed for disease-specific survival, local recurrence-free survival, complications, and functional outcome. The applied carbon ion dose ranged from 54.0 Gray equivalent (GyE) to 73.6 GyE (median 70.4). Results: The mean age at treatment was 55 years for the surgery group and 65 years for the carbon ion RT group. The median duration of follow-up was 76 months for the surgery group and 49 months for the carbon ion RT group. The local recurrence-free survival rate at 5 years was 62.5% for the surgery and 100% for the carbon ion RT group, and the disease-specific survival rate at 5 years was 85.7% and 53.3%, respectively. Urinary-anorectal function worsened in 6 patients (60%) in the surgery group, but it was unchanged in all the patients who had undergone carbon ion RT. Postoperative wound complications requiring reoperation occurred in 3 patients (30%) after surgery and in 1 patient (14%) after carbon ion RT. The functional outcome evaluated using the Musculoskeletal Tumor Society scoring system revealed 55% in the surgery group and 75% in the carbon ion RT group. Of the six factors in this scoring system, the carbon ion RT group had significantly greater scores in emotional acceptance than did the surgery group. Conclusion: Carbon ion RT results in a high local control rate and preservation of urinary-anorectal function compared with surgery.

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

    International Nuclear Information System (INIS)

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

  20. Electron impact excitation of carbon and oxygen ions

    International Nuclear Information System (INIS)

    This report is an attempt at a comprehensive compilation of currently available theoretical data on electron impact excitation of carbon and oxygen ions. It is designed to be of use primarily to theoretical atomic physicists, allowing them a broader than usual view of how various approximations compare. We do not attempt to place an estimate on the accuracy to which any of the collision strengths are known. The reader may obtain some idea of the accuracy from the spread in the calculations. Further, we do not evaluate rate coefficients or make any comparison with observed results. We do provide simple analytic fits to the data, where possible, thus allowing the reader to make comparison with observation or evaluate rate coefficients if he desires. The present data contains little about resonance effects, due to the difficulty of their presentation. It is possible that resonances could make a considerable change in the average collision strength near threshold, and this topic requires further study

  1. 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.)

  2. 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.

  3. 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)

  4. 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...

  5. 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 

  6. 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)

  7. Investigation of physiologically active products obtained from carbon-ion irradiated actinomycetes

    International Nuclear Information System (INIS)

    Charged particles such as carbon-ions are superior to X-rays or gamma-rays in the physical and biological characteristics. The propose research project is aimed to provide new insights on antibiotic development. Mutants were prepared by heavy ion irradiation, examined the effect of physiologically active substances produced. Product(s) from carbon-ion irradiated microorganera suppressed growth of human cololectal cancer cells and breast cancer cells. We suggested that carbon-ion irradiated actinomycetes produce antitumor active product(s) for cololectal and breast cancer cells. (author)

  8. 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)

  9. Glass carbon surface modified by the fluorine ion irradiation

    Science.gov (United States)

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

    2012-02-01

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

  10. Glass carbon surface modified by the fluorine ion irradiation

    International Nuclear Information System (INIS)

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

  11. 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.

  12. Glass carbon surface modified by the fluorine ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Teranishi, Yoshikazu, E-mail: teranishi.yoshikazu@iri-tokyo.jp [Tokyo Metropolitan Industrial Technology Research Institute (TIRI), Nishigaoka 3-13-10, Kitaku, Tokyo 115-8586 (Japan); Ishizuka, Masanori [Tokyo University, Inst. of Phys. and Chem. Res., RIKEN (Japan); Kobayashi, Tomohiro [Chuo University, Inst. of Phys. and Chem. Res., RIKEN (Japan); Nakamura, Isao; Uematu, Takahiko; Yasuda, Takeshi; Mitsuo, Atsushi; Morikawa, Kazuo [Tokyo Metropolitan Industrial Technology Research Institute (TIRI), Nishigaoka 3-13-10, Kitaku, Tokyo 115-8586 (Japan)

    2012-02-01

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

  13. Effects of Carbon Ions on Primary Cultures of Mouse Brain Cells

    Science.gov (United States)

    Nojima, K.; Ando, K.; Fujiwara, H.; Ando, S.

    Primary mixed cultures of astrocytes and microglia were obtained from neonatal mice, and were irradiated with high-LET carbon ions. Immunohistochemical staining showed astrocytes survived more prominently than microglia. Tagged with specific antibodies, astrocytes and microglia surviving after irradiation were counted by flow cytometry. Decreases in the number of microglia and astrocytes were detected at a dose as small as 2 Gy when Day 5 cultures were irradiated with 13 keV/μm carbon ions. When the cultures were irradiated on Day 10, the dose-dependent decrease of microglia was more prominent for 13 keV/μun carbon ions than 70 keV/μm carbon ions. Astrocytes showed a marginal decrease at Day 10 and Day 14. We concluded that microglia are more sensitive than astrocytes to carbon ions and X-rays, and that the radiosensitivity of microglia depends on both differentiation/proliferation status and radiation quality

  14. Carbon nanotube film anodes for flexible lithium ion batteries

    Science.gov (United States)

    Yoon, Sora; Lee, Sehyun; Kim, Soyoung; Park, Kyung-Won; Cho, Daehwan; Jeong, Youngjin

    2015-04-01

    In this study, carbon nanotube (CNT) film anodes are prepared for use in flexible lithium ion batteries, and the electrochemical performance of the CNT film anodes is evaluated. The CNT films are synthesized via chemical vapor deposition and direct spinning. The films are heat-treated under a nitrogen atmosphere at a high temperature to study the effects of heat treatment on the battery performance. The electrodes made with the CNT films are characterized via charge-discharge test, cyclic voltammetry, and impedance measurement. The results indicate that batteries with films heat-treated under a nitrogen atmosphere show a higher capacity, which can be a result of their high crystalline perfection. The impedance analysis shows that a lower resistance at the interface can be obtained by using heat-treated films. The charge-discharge tests are carried out by adjusting the rate from C/2 to 10C, and when the rate slows from 10C to 1C, the capacity of the samples largely recovers. The nitrogen/heat-treated CNT film electrodes present a capacity that is twice as high, such as 2C, 5C, and 10C, than untreated CNT film electrodes. These results indicate that the carbon nanotube film anodes have high potential for use in portable and wearable computers due to their flexibility.

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

    International Nuclear Information System (INIS)

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

  16. 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.)

  17. Effect of intense laser and energetic ion irradiation on Raman modes of Multiwalled Carbon Nanotubes

    International Nuclear Information System (INIS)

    The effects of intense laser and energetic ion irradiation on Raman vibrational modes of Multiwalled Carbon Nanotubes have been investigated. The intensity ratio of D and G modes decreases with increase in laser power density and remains almost constant with decrease of laser power density. The intensity ratio of D mode to G mode for ion irradiated Multiwalled Carbon Nanotubes decreases at low fluence (4 x 1011 ions/cm2) and increases further with increase in ion fluence. The results show that ion irradiation at low fluence and laser irradiation lead to purification/ordering of the nanotubes.

  18. Generation of intense pulsed ion beam by a Br type magnetically insulated ion diode with carbon plasma gun

    International Nuclear Information System (INIS)

    To apply the pulsed heavy ion beam (PHIB) to an implantation process of semiconductor, purity of the ion beam is very important. To obtain a pure PHIB we have proposed a new type of accelerator using bipolar pulse. To develop the accelerator we are developing a new type of Br ion diode using a carbon plasma gun. By using the plasma gun, ion source plasma of ion current density approx. = 30 A/cm2 was obtained. The Br ion diode was successfully operated with plasma gun at diode voltage approx. = 100 kV, diode current approx. = 1 kA, pulse duration approx. = 200 ns and 3 A/cm2 of ion current density was obtained. (author)

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

    OpenAIRE

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

    2014-01-01

    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low wo...

  20. Late quaternary fluctuations in carbonate and carbonate ion content in the northern Indian ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.S.

    =] of the water bathing the core tops, were computed from different GEOSECS staions for the Westrn and Eastern Indian Ocean separately (Table 2,3 & 4, Fig. 9 &14). GEOSECS taion Nos. 417,420 and 425 whic lie along a transect in the westrn Indian Ocean...-normalized carbonate ion (CO3=*) range from 90 to 125µmol kg-1 in the tropical region of the world oceans with a weight los of 0.3 ± 0.05µg mol -1kg-1 (Broecker and Clark, 201d). Botm water CO3=* concentration bathing the core tops are in the range of 88 to 13 μmolkg-1...

  1. Development of Compact Electron Cyclotron Resonance Ion Source with Permanent Magnets for High-Energy Carbon-Ion Therapy

    Science.gov (United States)

    Muramatsu, M.; Kitagawa, A.; Iwata, Y.; Hojo, S.; Sakamoto, Y.; Sato, S.; Ogawa, Hirotsugu; Yamada, S.; Ogawa, Hiroyuki; Yoshida, Y.; Ueda, T.; Miyazaki, H.; Drentje, A. G.

    2008-11-01

    Heavy-ion cancer treatment is being carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) with 140 to 400 MeV/n carbon ions at National Institute of Radiological Sciences (NIRS) since 1994. At NIRS, more than 4,000 patients have been treated, and the clinical efficiency of carbon ion radiotherapy has been demonstrated for many diseases. A more compact accelerator facility for cancer therapy is now being constricted at the Gunma University. In order to reduce the size of the injector (consists of ion source, low-energy beam transport and post-accelerator Linac include these power supply and cooling system), an ion source requires production of highly charged carbon ions, lower electric power for easy installation of the source on a high-voltage platform, long lifetime and easy operation. A compact Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets is one of the best types for this purpose. An ECRIS has advantage for production of highly charged ions. A permanent magnet is suitable for reduce the electric power and cooling system. For this, a 10 GHz compact ECRIS with all permanent magnets (Kei2-source) was developed. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas-injection side, while the minimum B strength is 0.25 T. These parameters have been optimized for the production of C4+ based on experience at the 10 GHz NIRS-ECR ion source. The Kei2-source has a diameter of 320 mm and a length of 295 mm. The beam intensity of C4+ was obtained to be 618 eμA under an extraction voltage of 30 kV. Outline of the heavy ion therapy and development of the compact ion source for new facility are described in this paper.

  2. Development of Compact Electron Cyclotron Resonance Ion Source with Permanent Magnets for High-Energy Carbon-Ion Therapy

    International Nuclear Information System (INIS)

    Heavy-ion cancer treatment is being carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) with 140 to 400 MeV/n carbon ions at National Institute of Radiological Sciences (NIRS) since 1994. At NIRS, more than 4,000 patients have been treated, and the clinical efficiency of carbon ion radiotherapy has been demonstrated for many diseases. A more compact accelerator facility for cancer therapy is now being constricted at the Gunma University. In order to reduce the size of the injector (consists of ion source, low-energy beam transport and post-accelerator Linac include these power supply and cooling system), an ion source requires production of highly charged carbon ions, lower electric power for easy installation of the source on a high-voltage platform, long lifetime and easy operation. A compact Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets is one of the best types for this purpose. An ECRIS has advantage for production of highly charged ions. A permanent magnet is suitable for reduce the electric power and cooling system. For this, a 10 GHz compact ECRIS with all permanent magnets (Kei2-source) was developed. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas-injection side, while the minimum B strength is 0.25 T. These parameters have been optimized for the production of C4+ based on experience at the 10 GHz NIRS-ECR ion source. The Kei2-source has a diameter of 320 mm and a length of 295 mm. The beam intensity of C4+ was obtained to be 618 eμA under an extraction voltage of 30 kV. Outline of the heavy ion therapy and development of the compact ion source for new facility are described in this paper.

  3. 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.

  4. Application of Carbon Nanomaterials in Lithium-Ion Battery Electrodes

    Science.gov (United States)

    Jaber-Ansari, Laila

    Carbon nanomaterials such as single-walled carbon nanotubes (SWCNTs) and graphene have emerged as leading additives for high capacity nanocomposite lithium ion battery electrodes due to their ability to improve electrode conductivity, current collection efficiency, and charge/discharge rate for high power applications. In this work, the these nanomaterials have been developed and their properties have been fine-tuned to help solve fundamental issues in conventional lithium ion battery electrodes. Towards this end, the application of SWCNTs in lithium-ion anodes has been studied. As-grown SWCNTs possess a distribution of physical and electronic structures, and it is of high interest to determine which subpopulations of SWCNTs possess the highest lithiation capacity and to develop processing methods that can enhance the lithiation capacity of underperforming SWCNT species. Towards this end, SWCNT electronic type purity is controlled via density gradient ultracentrifugation, enabling a systematic study of the lithiation of SWCNTs as a function of metal versus semiconducting content. Experimentally, vacuum filtered freestanding films of metallic SWCNTs are found to accommodate lithium with an order of magnitude higher capacity than their semiconducting counterparts. In contrast, SWCNT film densification leads to the enhancement of the lithiation capacity of semiconducting SWCNTs to levels comparable to metallic SWCNTs, which is corroborated by theoretical calculations. To understand the interaction of the graphene with lithium ions and electrolyte species during electrochemical we use Raman spectroscopy in a model system of monolayer graphene transferred on a Si(111) substrate and density functional theory (DFT) to investigate defect formation as a function of lithiation. This model system enables the early stages of defect formation to be probed in a manner previously not possible with commonly-used reduced graphene oxide or multilayer graphene substrates. Using ex

  5. 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.

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

    International Nuclear Information System (INIS)

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

  7. Carbon ion radiotherapy with epidermal growth factor receptor (EGFR) inhibitor for refractory gastrointestinal carcinomas in mice

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate the combined effect of carbon ion radiotherapy with epidermal growth factor receptor (EGFR) inhibitor on refractory gastrointestinal carcinomas in mice. As a preliminary experiment, we assessed the sensitization effect of gemcitabine (GEM) on carbon ion radiotherapy for tumor cells and the normal tissues by using SCCVII of C3H mice. Tumor cells treated with low linear energy transfer (LET) carbon ion irradiation showed the sensitizing effect of GEM. However, no sensitizating effect was shown for the normal tissue irradiated with either low LET or with high LET. (author)

  8. Investigation of physiologically active products obtained from carbon-ion irradiated actinomycetes

    International Nuclear Information System (INIS)

    Charged particles such as carbon-ions are superior to X-rays or gamma-rays in the physical and biological characteristics. The propose research project is aimed to provide new insights on antibiotic development. Product(s) from carbon-ion irradiated microorganera suppressed growth of human leukemia cells and mammary tumor cells. This product(s) induced apoptosis in human leukemia cells. We suggested that carbon-ion irradiated actinomycetes produce antitumor active product(s) for leukemia cells and mammary tumor cells. (author)

  9. 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.

  10. 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

  11. A Binary Cyclic Carbonates-Based Electrolyte Containing Propylene Carbonate and Trifluoropropylene Carbonate for 5 V Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Graphical abstract: A binary cyclic carbonates-based electrolyte containing propylene carbonate and trifluoropropylene carbonate with an optimized volume ratio is successfully applied for 5 V lithium-ion batteries. Display Omitted -- Highlights: •A binary solvent electrolyte containing TFPC and PC is used for high-voltage LIBs. •Volume ratio of TFPC/PC is a crucial factor affecting the physical and electrochemical properties. •The binary solvent can maintain a stable liquid phase in a broad temperature range. •Graphite anode works well in the electrolyte of 1 mol dm−3 LiPF6-TFPC/PC (1:2). •The optimized electrolyte has good compatibility with 5 V LiNi0.5Mn1.5O4 cathode. -- Abstract: To widen the operating potential window of electrolyte used for lithium-ion batteries, a binary cyclic carbonates-based electrolyte containing propylene carbonate (PC) and trifluoropropylene carbonate (TFPC) with an optimized volume ratio has been successfully proposed. The main function of additive TFPC is to establish a stable SEI layer on graphite electrode and suppress the intercalation reaction of PC molecules. Unlike the previous works, where the TFPC/PC involved electrolyte was simply estimated at a certain volume ration and recognized as an unfavorable system, in this work, the physical properties of the electrolyte solutions with a series of volume ratios of TFPC/PC and their electrochemical performances in a graphite/Li cell and 5 V LiNi0.5Mn1.5O4/Li cell have been systematically studied. The electrolyte of 1 mol dm−3 LiPF6-TFPC/PC (1:2) is adopted as the optimized system due to its high ionic conductivity, low viscosity, broad operating potential window, wide liquid temperature range (−50 ∼ 240 °C) and suitable film-forming property. Both the graphite and LiNi0.5Mn1.5O4 electrodes were found to exhibit high reversible capacity and superb rate performance in the optimized electrolyte, making us have a new recognition of this important binary solvent

  12. 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...

  13. Carbonized-leaf Membrane with Anisotropic Surfaces for Sodium-ion Battery.

    Science.gov (United States)

    Li, Hongbian; Shen, Fei; Luo, Wei; Dai, Jiaqi; Han, Xiaogang; Chen, Yanan; Yao, Yonggang; Zhu, Hongli; Fu, Kun; Hitz, Emily; Hu, Liangbing

    2016-01-27

    A simple one-step thermal pyrolysis route has been developed to prepare carbon membrane from a natural leaf. The carbonized leaf membrane possesses anisotropic surfaces and internal hierarchical porosity, exhibiting a high specific capacity of 360 mAh/g and a high initial Coulombic efficiency of 74.8% as a binder-free, current-collector-free anode for rechargeable sodium ion batteries. Moreover, large-area carbon membranes with low contact resistance are fabricated by simply stacking and carbonizing leaves, a promising strategy toward large-scale sodium-ion battery developments. PMID:26727650

  14. 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

  15. 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.

  16. 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)

  17. 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.

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

    International Nuclear Information System (INIS)

    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

  19. The morphology and structure of one-dimensional carbon-carbon composite under high-fluence ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Andrianova, N.N.; Borisov, A.M. [Institute of Nuclear Physics, Moscow State University, Leninsky Gori, 119991 Moscow (Russian Federation); Mashkova, E.S. [Institute of Nuclear Physics, Moscow State University, Leninsky Gori, 119991 Moscow (Russian Federation)], E-mail: es_mashkova@mail.ru; Virgiliev, Yu.S. [NIIgraphite, Electrodnaya 2, 111141 Moscow (Russian Federation)

    2009-08-15

    The temperature dependences of the ion-induced electron emission yield {gamma}(T), the crystal structure, and the morphology of a surface layer of the one-dimensional carbon fiber composite KUP-VM (1D) under high-fluence (10{sup 18}-10{sup 19} ion/cm{sup 2}) irradiation with 30 keV N{sub 2}{sup +} ions at normal incidence both perpendicular and parallel to the fiber directions have been studied. The target temperature has been varied during continuous irradiation from T = -180 to 400 deg. C. The surface analysis has been performed by the RHEED, SEM and RBS techniques. The surface microgeometry was studied using laser goniophotometry (LGP). It has been found that ion irradiation results in a loss of anisotropy of the surface layer structure because of amorphization at room temperature or recrystallization at a temperature higher than the ion-induced annealing temperature. The fiber morphology anisotropy remains under ion irradiation.

  20. The morphology and structure of one-dimensional carbon-carbon composite under high-fluence ion irradiation

    International Nuclear Information System (INIS)

    The temperature dependences of the ion-induced electron emission yield γ(T), the crystal structure, and the morphology of a surface layer of the one-dimensional carbon fiber composite KUP-VM (1D) under high-fluence (1018-1019 ion/cm2) irradiation with 30 keV N2+ ions at normal incidence both perpendicular and parallel to the fiber directions have been studied. The target temperature has been varied during continuous irradiation from T = -180 to 400 deg. C. The surface analysis has been performed by the RHEED, SEM and RBS techniques. The surface microgeometry was studied using laser goniophotometry (LGP). It has been found that ion irradiation results in a loss of anisotropy of the surface layer structure because of amorphization at room temperature or recrystallization at a temperature higher than the ion-induced annealing temperature. The fiber morphology anisotropy remains under ion irradiation.

  1. Electrical resistance of diamond implanted at liquid nitrogen temperature with carbon ions

    International Nuclear Information System (INIS)

    Carbon ion implantation of diamond to high fluence, below the temperature at which diamond growth can occur, usually leads to black layers of high conductivity. This study shows that for a low enough temperature of the diamond during implantation, a black layer with high electrical resistance can develop. In particular, carbon ion implantation at liquid nitrogen temperature, leads to an implanted layer with electrical resistance about one million times higher than the resistance obtained for implantation at temperatures above room temperature. (author)

  2. Electron spin resonance investigations on ion beam irradiated single-wall carbon nanotubes

    International Nuclear Information System (INIS)

    ESR investigations on single-wall carbon nanotubes irradiated with accelerated protons, helium ions, and neon ions are reported. All spectra were accurately simulated assuming that the resonance line is a convolution of up to 4 lines originating from catalyst residues, amorphous carbon, and electrons delocalized over the conducting domains of nanotubes. The faint line observed in irradiated nanotubes at g > 2.25 was assigned to magnetic impurities. However, there are no sufficient data to confirm that this line is connected to radiation-induced magnetism in carbon nanotubes. The generation of paramagnetic defects due to the bombardment of single-wall carbon nanotubes by accelerated ions is reported. These data correlate with previous Raman and thermal investigations on the same single-wall carbon nanotubes and reveals their sensitivity to ionizing radiation. The temperature dependence of ESR spectra in the range 25-250 K was used to identify the components of the ESR spectra

  3. Feasibility of carbon ion radiotherapy for locally advanced sinonasal adenocarcinoma

    International Nuclear Information System (INIS)

    Background and purpose: To evaluate the safety and efficacy of carbon ion radiotherapy (CIRT) for locally advanced sinonasal adenocarcinoma. Material and methods: Twenty-two patients with sinonasal adenocarcinoma were treated with CIRT. CIRT was the primary treatment for 16 patients. Four patients received CIRT for local recurrence after surgery and two for residual tumour after surgery or chemotherapy. At the start of CIRT, 1 patient had T-classification (T) 2 disease, 2 had T3 disease, 5 had T4a disease, and 14 had T4b disease. Fourteen patients were treated with 57.6 Gy equivalent (GyE)/16 fractions, and 8, with 64.0 GyE/16 fractions. Results: The median follow-up period was 43 months for all patients. The 3-year local control and loco-regional control rates for all patients were 76.9% (95% confidence interval [CI] = 56.7–97.1%) and 61.3% (95% CI = 38.5–84.1%), respectively. The 3-year overall survival and disease-specific survival rates were 59.1% (95% CI = 38.6–79.6%) and 65.6% (95% CI = 44.9–86.3%), respectively. Acute reactions of grade 3 of the skin and mucosa were observed in 2 and 4 patients, respectively. Late reactions included lateral visual loss (5 patients), mucosal ulceration (1 patient), and brain necrosis with clinical symptoms (1 patient). In the 5 patients who developed visual loss, the optic nerve was close to the tumour. Conclusions: CIRT was effective and generally safe for locally advanced sinonasal adenocarcinoma

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

    Science.gov (United States)

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

    2014-08-01

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

  5. 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...

  6. Electrochemical properties of carbon materials implanted with high energy heavy ions

    International Nuclear Information System (INIS)

    Carbon materials have some allotropes such as diamond, graphite and amorphous carbon. These allotropes show significantly different natures depending on their structures. Ion implantation has two different effects on the modification of material surface layers, that is, the structural modification induced by the energy radiation accompanying ion beam bombardment, and the composition change introduced by doping surface layers with different elements. Carbon materials have been used as fuel, tools, electrical conductors, chemical instruments, electrochemical electrodes and composite materials because of their natures, such as the brightness and hardness of diamond and the chemical stability and electro-conductivity of black carbon. For all these uses, the surface properties are important, accordingly, ion implantation is an important technique for modifying the surface layers. In this paper, the main features of the ion implantation on the surface modification of diamond and glassy carbon substrates, and the chemical and electrochemical properties of glassy carbon implanted with various elements are reported. The electrode characteristics of ion-implanted glassy carbon are affected by the composition change and the change to amorphous form. (K.I.)

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

    Czech Academy of Sciences Publication Activity Database

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

    2011-01-01

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

  8. 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

  9. 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.

  10. 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.

  11. 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

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

    International Nuclear Information System (INIS)

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

  13. 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)

  14. A moderator ion exchange model to predict carbon-14 behaviour during operations

    International Nuclear Information System (INIS)

    Carbon-14 emissions from CANDU 6 stations are reduced through the removal of inorganic carbon ions by the ion exchange (IX) columns in the moderator purification system. A model has been developed to simulate the ion exchange behaviour of anions and cations present in the moderator. The model can be used to generate breakthrough curves for IX columns. Results from the program were compared to breakthrough curves generated by a small-scale experimental facility as well as data collected from Wolsong-3 where the IX column remained in service well past the recommended time. In both cases, the breakthrough curves were similar to the collected data. (author)

  15. 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)

  16. 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...

  17. 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.

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

    International Nuclear Information System (INIS)

    To evaluate the cytotoxic effect of carbon ion radiotherapy and chemotherapy in glioblastoma cells in vitro. 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. 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. 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

  19. 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.

  20. 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...

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

    International Nuclear Information System (INIS)

    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

  2. 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.

  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. Improvement of polydimethylsiloxane guide tube for nerve regeneration treatment by carbon negative-ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, H. E-mail: tsuji@kuee.kyoto-u.ac.jp; Izukawa, M.; Ikeguchi, R.; Kakinoki, R.; Sato, H.; Gotoh, Y.; Ishikawa, J

    2003-05-01

    Modification of polydimethylsiloxane (PDMS) rubber by negative ion-implantation was investigated for improvement of nerve regeneration property. The PDMS rubber surface was found to have more hydrophilic property after carbon negative-ion implantation than before. At the conditions of 10 keV and 3.0 x 10{sup 15} ions/cm{sup 2}, the contact angle decreased to 83 deg. from 100 deg. . The reason of the hydrophilic modification is due to hydrophilic functional groups such as hydroxyl formed at the surface by radiation effect of ion implantation. The in vivo regeneration test of rat sciatic nerve was performed by using 18-mm-long PDMS rubber tubes with inner diameter of 2 mm, the inner surface of which was implanted with carbon negative ions at the above conditions. At 24 weeks after the clinical surgery, the sciatic nerve was regenerated through the tube between the proximal and distal nerve stumps.

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

    International Nuclear Information System (INIS)

    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. 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.

  7. 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

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

    Science.gov (United States)

    Shornikov, A.; Wenander, F.

    2016-04-01

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

  9. 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.

  10. 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.

  11. Nucleation and growth of carbon onions by means of simultaneous electron microscopic observation under ion implantation

    International Nuclear Information System (INIS)

    In-situ and ex-situ TEM observation was performed in copper implanted with carbon ions at temperature from 570 K to 973 K. Carbon clusters, such as carbon onions (concentric graphic spheres) and nanocapsules (concentric graphitic spheres with cavities), were observed with amorphous carbon layers. Statistics of cluster size as a function of implantation temperature, ion fluence and substrate crystallinity revealed the nucleation processes of the clusters. One is the formation of graphitic layers on grain boundaries. The other is the nucleation of graphitic cages, probably fullerenes, due to both high concentration of carbon atoms and high amount of radiation damage. Simultaneous observation of microstructural evolution under implantation revealed that onions were formed inside the substrate not surface and that they segregate at surface due to radiation-enhanced evaporation. (author)

  12. 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

  13. 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.

  14. Secondary Ion Mass Spectrometry of Small-Molecule Solids at Cryogenic Temperatures. 1. Nitrogen and Carbon Monoxide

    OpenAIRE

    Jonkman, Harry T.; Michl, Josef

    1981-01-01

    Secondary ion mass spectra of solid nitrogen and carbon monoxide were observed at 15 K. The effects of the nature and energy of the primary probe ion were investigated. Direct charge transfer, inelastic momentum transfer, association reactions, and ion-molecule reactions all seem to contribute to the formation of the secondary charged particles. With the heavier probe ions extensive cluster formation was observed.

  15. 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.

  16. Calculation of Lifetime of Charge-Exchanging Carbon Targets in Intense Heavy Ion Beams

    CERN Document Server

    Gikal, B N; Kazacha, V I; Kamanin, D V

    2005-01-01

    Influence of the radiation damage and sublimation effects on the lifetime of carbon targets used for the accelerated ion beam extraction from cyclotrons by the charge-exchanging method is considered. The theoretical models permitting evaluation of the carbon target lifetime depending on their and ion beam parameters are presented both for the radiation damage and sublimation effects. It is shown that for the U-400 cyclotron carbon targets 50 $\\mu$g/cm$^{2}$ thick and for the ion beam flux density up to 100 p$\\mu$A/cm$^{2}$ the main effect defining the carbon target lifetime is the radiation damage. If the carbon target thickness and the ion beam flux density are greater, the target lifetime is defined already by the sublimation effect. In this connection "casting pipes" can be formed in the target, affecting on the mean energy and the energy distribution dispersion of the ion beam flied through the target. Comparison of measured and calculated target lifetimes is carried out

  17. 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.

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

    International Nuclear Information System (INIS)

    We have investigated the tissue specificity of radioprotection by beer, which was previously found for human lymphocytes. C3H/He female mice, aged 14 weeks, received an oral administration of beer, ethanol or saline at a dose of 1 ml/mouse 30 min before whole-body irradiation with 137Cs γ rays or 50 keV/μm carbon ions. The dicentrics of chromosome aberrations in spleen cells were significantly (p0 (slope of a dose-survival curve) for γ rays and carbon ions as well. Beer administration significantly (p50/30 (radiation dose required to kill 50% of mice within 30 days) for γ rays and carbon ions. Ethanol-administration also significantly (p50/30 value for γ rays, but not for carbon ions. It is concluded that beer administration reduces the radiation injury caused by photons and carbon ions, depending on the tissue type. Radioprotection by beer administration is not solely due to OH radical-scavenging action by the ethanol contained in beer. (author)

  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. 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.

  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. Determination of carbon distributions in quenched and partitioned microstructures using nanoscale secondary ion mass spectroscopy

    International Nuclear Information System (INIS)

    A multi-modal characterization technique, which combines nanoscale secondary ion mass spectroscopy (Nano-SIMS) with a spatial resolution of ∼100 nm and electron back scatter diffraction (EBSD) to determine carbon distributions in austenite and martensite in a quenched and partitioned (Q&P) Fe–0.29C–2.95Mn–1.59Si steel is presented. Significant carbon enrichment of austenite was measured with decreased levels of carbon in martensite, supporting the carbon partitioning mechanism. Fresh untempered martensite could be identified, and different degrees of enrichment were observed for blocky and lath austenite

  3. Characterization of silicon- and carbon-based composite anodes for lithium-ion batteries

    International Nuclear Information System (INIS)

    In recent years development of active materials for negative electrodes has been of great interest. Special attention has been focused on the active materials possessing higher reversible capacity than that of conventional graphite. In the present work the electrochemical performance of some carbon/silicon-based materials has been analyzed. For this purpose various silicon-based composites were prepared using such carbon materials as graphite, hard carbon and graphitized carbon black. An analysis of charging-discharging processes at electrodes based on different carbon materials has shown that graphite modified with silicon is the most promising anode material. It has also been revealed that the irreversible capacity mainly depends on the content of Si. An optimum content of Si has been determined with taking into account that high irreversible capacity is not suitable for practical application in lithium-ion batteries. This content falls within the range of 8-10 wt%. The reversible capacity of graphite modified with 8 wt% carbon-coated Si was as high as 604 mAh g-1. The irreversible capacity loss with this material was as low as 8.1%. The small irreversible capacity of the material allowed developing full lithium-ion rechargeable cells in the 2016 coin cell configuration. Lithium-ion batteries based on graphite modified with silicon show gravimetric and volumetric specific energy densities which are higher by approximately 20% than those for a lithium-ion battery based on natural graphite

  4. Characterization of silicon and carbon dual ion-implanted metals with a nano-indentation

    International Nuclear Information System (INIS)

    The dual ion implantation of silicon and carbon into copper (99.9%), iron (99.9%), SKD11 steel and SUS304 austenitic stainless steels was carried out with a MeV energy ion accelerator. The cross-section of the implanted layer were observed with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The surface layers of the implanted substrates were investigated with X-ray photoelectron spectroscopy (XPS) and a transmission electron microscope (TEM). The hardness of the samples was tested with a nano-indentation. It was found with XPS Si (2p) spectra and TEM that a part of the Si ions and C ions formed an amorphous layer of SiC, carbide and metals by dual ion-implantation. The hardness of the dual ion-implanted steels were improved. The mechanism of hardness was suggested by cross-sectional TEM images. (author)

  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. 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.

  7. Carbon plasma immersion ion implantation of nickel-titanium shape memory alloys.

    Science.gov (United States)

    Poon, R W Y; Yeung, K W K; Liu, X Y; Chu, P K; Chung, C Y; Lu, W W; Cheung, K M C; Chan, D

    2005-05-01

    Nickel-titanium (NiTi) shape memory alloys possess super-elasticity in addition to the well-known shape memory effect and are potentially suitable for orthopedic implants. However, a critical concern is the release of harmful Ni ions from the implants into the living tissues. We propose to enhance the corrosion resistance and other surface and biological properties 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. Our tribological tests show that the treated surfaces are mechanically more superior and cytotoxicity tests reveal that both sets of plasma-treated samples favor adhesion and proliferation of osteoblasts. PMID:15585228

  8. 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.

  9. 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...

  10. 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.

  11. Formation of carbon nanostructures containing single-crystalline cobalt carbides by ion irradiation method

    Science.gov (United States)

    Wang, Zhipeng; Yusop, Zamri; Ghosh, Pradip; Hayashi, Yasuhiko; Tanemura, Masaki

    2011-02-01

    Carbon nanofibers (CNFs) with a diameter of 17 nm, and carbon nanoneedles (CNNs) with sharp tips have been synthesized on graphite substrates by ion irradiation of argon ions with the Co supplies rate of 1 and 3.4 nm/min, respectively. Energy dispersive X-ray spectrometry, combined with selected area electron diffraction patterns has been used to identify the chemical composition and crystallinity of these carbon nanostructures. The CNFs were found to be amorphous in nature, while the structures of the CNNs consisted of cubic CoCx, orthorhombic Co2C and Co3C depending on the cobalt content in the CNNs. The diameter of the carbide crystals was almost as large as the diameter of the CNN. Compared to the ion-induced nickel carbides and iron carbides, the formation of single-crystalline cobalt carbides might be due to the high temperature produced by the irradiation.

  12. Formation of carbon nanostructures containing single-crystalline cobalt carbides by ion irradiation method

    International Nuclear Information System (INIS)

    Carbon nanofibers (CNFs) with a diameter of 17 nm, and carbon nanoneedles (CNNs) with sharp tips have been synthesized on graphite substrates by ion irradiation of argon ions with the Co supplies rate of 1 and 3.4 nm/min, respectively. Energy dispersive X-ray spectrometry, combined with selected area electron diffraction patterns has been used to identify the chemical composition and crystallinity of these carbon nanostructures. The CNFs were found to be amorphous in nature, while the structures of the CNNs consisted of cubic CoCx, orthorhombic Co2C and Co3C depending on the cobalt content in the CNNs. The diameter of the carbide crystals was almost as large as the diameter of the CNN. Compared to the ion-induced nickel carbides and iron carbides, the formation of single-crystalline cobalt carbides might be due to the high temperature produced by the irradiation.

  13. Alanine Radiation Detectors in Therapeutic Carbon Ion Beams

    DEFF Research Database (Denmark)

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

        Radiotherapy with particles is getting more attention in Europe. New facilities for protons and heavier ions are finished, or near to the final status, some more are planed. Particle therapy with heavy ions is a challenge to dosimetry, since mixed particle fields occur in the peak region...... of the depth dose curves. Solid state detectors, such as diamond detectors, radiochromic films, TLDs and the amino acid alanine are used due to there good spatial resolution. If used in particle beams their response often exhibits a dependence on particle energy and type, so the acquired signal is not always...... proportional to absorbed dose. A model by Hansen and Olsen, based on the Track Structure Theory is available, which can predict the relative efficiency of some detectors, when the particle spectrum is known. For alanine detectors the model was successfully validated by Hansen and Olsen for several ion species...

  14. Modeling of Sheath Ion-Molecule Reactions in Plasma Enhanced Chemical Vapor Deposition of Carbon Nanotubes

    Science.gov (United States)

    Hash, David B.; Govindan, T. R.; Meyyappan, M.

    2004-01-01

    In many plasma simulations, ion-molecule reactions are modeled using ion energy independent reaction rate coefficients that are taken from low temperature selected-ion flow tube experiments. Only exothermic or nearly thermoneutral reactions are considered. This is appropriate for plasma applications such as high-density plasma sources in which sheaths are collisionless and ion temperatures 111 the bulk p!asma do not deviate significantly from the gas temperature. However, for applications at high pressure and large sheath voltages, this assumption does not hold as the sheaths are collisional and ions gain significant energy in the sheaths from Joule heating. Ion temperatures and thus reaction rates vary significantly across the discharge, and endothermic reactions become important in the sheaths. One such application is plasma enhanced chemical vapor deposition of carbon nanotubes in which dc discharges are struck at pressures between 1-20 Torr with applied voltages in the range of 500-700 V. The present work investigates The importance of the inclusion of ion energy dependent ion-molecule reaction rates and the role of collision induced dissociation in generating radicals from the feedstock used in carbon nanotube growth.

  15. Preparation of graphene on Cu foils by ion implantation with negative carbon clusters

    International Nuclear Information System (INIS)

    We report on few-layer graphene synthesized on Cu foils by ion implantation using negative carbon cluster ions, followed by annealing at 950 °C in vacuum. Raman spectroscopy reveals IG/I2D values varying from 1.55 to 2.38 depending on energy and dose of the cluster ions, indicating formation of multilayer graphene. The measurements show that the samples with more graphene layers have fewer defects. This is interpreted by graphene growth seeded by the first layers formed via outward diffusion of C from the Cu foil, though nonlinear damage and smoothing effects also play a role. Cluster ion implantation overcomes the solubility limit of carbon in Cu, providing a technique for multilayer graphene synthesis. (paper)

  16. Investigation of different-ligand complexes of holmium and erbium with NTA and carbonate ion

    International Nuclear Information System (INIS)

    Found out have been the optimum conditions for the formation of the lantanides (Ln) multiligand complexes with the nitriletriacetic acid (NTA) and the carbonate-ion. It has been established that the components correlation in complex compounds is equal to 1:1:1. Computed have been the values of the oscillator forces of the absorption bands, that conform to the ''supersensitive'' migration of the multiligand complexes, It is shown that the increment in the oscillator forces, the induced entering of one carbonate-ion into the Ln-NTA complex molecule conforms to about 1/4 of the oscillator forces increment during the migration from the aquo ion to the [Ln(CO3)4]5- complex carbonaceous ion

  17. 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.

  18. Photoluminescence and reflectivity of polymethylmethacrylate implanted by low-energy carbon ions at high fluences

    International Nuclear Information System (INIS)

    Highlights: ► Photoluminescence was studied in carbon implanted polymethylmethacrylate (PMMA). ► A significant photoluminescence enhancement occurred at ion fluence of 5 × 1016 cm−2. ► Photoluminescence and Raman responses revealed carbon nanoclustered structures. ► Reflectivity of carbon implanted PMMA depended on both ion fluence and wavelength. ► A noticeable reflectivity modification appeared at ion fluence of 1 × 1016 cm−2. - Abstract: Polymethylmethacrylate (PMMA) specimens were implanted with 30 keV carbon ions in a fluence range of 1 × 1016 to 2 × 1017 cm−2, and photoluminescence (PL) and reflectivity of the implanted samples were examined. A luminescent band with one peak was found in PL spectra excited by 480 nm line, but its intensity did not vary in parallel with ion fluence. The strongest PL occurred at the fluence of 5 × 1016 cm−2. Results from visible-light-excited micro-Raman spectra indicated that the formation of hydrogenated amorphous carbon structures in subsurface layer and their evolutions with ion fluence could be responsible for the observed PL responses. Measurements of the small-angle reflectance spectra from both the implanted and rear surfaces of samples in the ultraviolet–visible (UV–vis) range demonstrated a kind of both fluence-dependent and wavelength-related reflectivity variations, which were attributed to the structural changes induced by ion implantation. A noticeable reflectivity modification, which may be practically used, could be found at the fluence of 1 × 1016 cm−2.

  19. Photoluminescence and reflectivity of polymethylmethacrylate implanted by low-energy carbon ions at high fluences

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jun; Zhu Fei; Zhang Bei; Liu Huixian; Jia Guangyi [School of Science, Tianjin University, Tianjin 300072 (China); Liu Changlong, E-mail: liuchanglong@tju.edu.cn [School of Science, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Institute of Advanced Materials Physics Faculty of Science, Tianjin 300072 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Photoluminescence was studied in carbon implanted polymethylmethacrylate (PMMA). Black-Right-Pointing-Pointer A significant photoluminescence enhancement occurred at ion fluence of 5 Multiplication-Sign 10{sup 16} cm{sup -2}. Black-Right-Pointing-Pointer Photoluminescence and Raman responses revealed carbon nanoclustered structures. Black-Right-Pointing-Pointer Reflectivity of carbon implanted PMMA depended on both ion fluence and wavelength. Black-Right-Pointing-Pointer A noticeable reflectivity modification appeared at ion fluence of 1 Multiplication-Sign 10{sup 16} cm{sup -2}. - Abstract: Polymethylmethacrylate (PMMA) specimens were implanted with 30 keV carbon ions in a fluence range of 1 Multiplication-Sign 10{sup 16} to 2 Multiplication-Sign 10{sup 17} cm{sup -2}, and photoluminescence (PL) and reflectivity of the implanted samples were examined. A luminescent band with one peak was found in PL spectra excited by 480 nm line, but its intensity did not vary in parallel with ion fluence. The strongest PL occurred at the fluence of 5 Multiplication-Sign 10{sup 16} cm{sup -2}. Results from visible-light-excited micro-Raman spectra indicated that the formation of hydrogenated amorphous carbon structures in subsurface layer and their evolutions with ion fluence could be responsible for the observed PL responses. Measurements of the small-angle reflectance spectra from both the implanted and rear surfaces of samples in the ultraviolet-visible (UV-vis) range demonstrated a kind of both fluence-dependent and wavelength-related reflectivity variations, which were attributed to the structural changes induced by ion implantation. A noticeable reflectivity modification, which may be practically used, could be found at the fluence of 1 Multiplication-Sign 10{sup 16} cm{sup -2}.

  20. Unity yield conditions for sputtering of graphite by carbon ions

    International Nuclear Information System (INIS)

    Selfsputtering yields for graphite have been investigated as function of ion energy, target temperature and angle of incidence. While the yield for normal incidence at room temperature never exceeds unity, both enhanced temperature and grazing angle of incidence can lead to a selfsputtering larger than one. Theoretical predictions of 100% ion reflection at angles of incidence above 850 could not be observed for energies smaller than 300 eV. The data are interpolated to construct regions of selfsputtering larger than unity in the energy versus angle-of-incidence space for temperatures up to 1900 K. (orig.)

  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. 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

  3. Carbon nanotubes as masks against ion irradiation: An insight from atomistic simulations

    International Nuclear Information System (INIS)

    Recent experiments show that carbon nanotubes can be used as masks against ion irradiation to make metallic nanowires of a few nanometers in width. In order to ascertain the limitations of this technique, we use molecular dynamics and simulate ion irradiation of multiwalled nanotubes. We derive an equation which for a given nanowire material allows one to estimate the theoretical limit on the minimum width of the wire which can be made using this technique

  4. Regularities of ion-electron emission of one-dimensional carbon-based composite materials

    International Nuclear Information System (INIS)

    The temperature dependence of ion-electron emission yield, γ(T), developed topography and surface crystalline structure of carbon-based composite material KUP- VM under high-fluence 30 keV N2+ ion irradiation has been studied. Complex two-stage nature of γ(T) dependence is formed due to the process of dynamic annealing of the radiation damage in structural components of composite material

  5. Electron impact excitation of carbon-like ions: An assessment of the available theoretical data

    International Nuclear Information System (INIS)

    Electron impact excitation of ions of the carbon-like isoelectronic sequence from O III to Fe XXI is reviewed starting from previous critical compilations. Comparisons between results obtained from the distorted-wave and the R-matrix methods have been made. The effective collision strengths have been compared along the sequence. The isoelectronic trends should be useful in interpolating data for ions where no specific calculations are available. 24 refs., 23 figs., 6 tabs

  6. Encapsulation of α-Particle–Emitting 225Ac3+ Ions Within Carbon Nanotubes

    Science.gov (United States)

    Matson, Michael L.; Villa, Carlos H.; Ananta, Jeyarama S.; Law, Justin J.; Scheinberg, David A.; Wilson, Lon J.

    2016-01-01

    225Ac3+ is a generator of α-particle–emitting radionuclides with 4 net α-particle decays that can be used therapeutically. Targeting 225Ac3+ by use of ligands conjugated to traditional bifunctional chelates limits the amount of 225Ac3+ that can be delivered. Ultrashort, single-walled carbon nanotubes (US-tubes), previously demonstrated as sequestering agents of trivalent lanthanide ions and small molecules, also successfully incorporate 225Ac3+. Methods Aqueous loading of both 225Ac3+ ions and Gd3+ ions via bath sonication was used to construct 225Ac@gadonanotubes (225Ac@GNTs). The 225Ac@GNTs were subsequently challenged with heat, time, and human serum. Results US-tubes internally loaded with both 225Ac3+ ions and Gd3+ ions show 2 distinct populations of 225Ac3+ ions: one rapidly lost in human serum and one that remains bound to the US-tubes despite additional challenge with heat, time, and serum. The presence of the latter population depended on cosequestration of Gd3+ and 225Ac3+ ions. Conclusion US-tubes successfully sequester 225Ac3+ ions in the presence of Gd3+ ions and retain them after a human serum challenge, rendering 225Ac@GNTs candidates for radioimmunotherapy for delivery of 225Ac3+ ions at higher concentrations than is currently possible for traditional ligand carriers. PMID:25931476

  7. 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

  8. The first French randomized prospective study of the economic and medical benefit of carbon ion radiotherapy

    International Nuclear Information System (INIS)

    Carbon ion therapy is an innovative radiotherapy modality for non-operable radio-resistant or resected cancers. Its efficiency is due to improved ballistic accuracy and biological efficiency. The authors present the first phase III study of carbon ion therapy in France. This technique concerns some sarcomas and adenoid cystic carcinomas of head and neck. The authors indicate the possible treatment procedures (doses, sessions) for the different types of cancers, and how the study is to be performed (number of patients, randomization, and multicentre approach). Short communication

  9. 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.

  10. MnO-carbon hybrid nanofiber composites as superior anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    MnO-carbon hybrid nanofiber composites are fabricated by electrospinning polyimide/manganese acetylacetonate precursor and a subsequent carbonization process. The composition, phase structure and morphology of the composites are characterized by scanning and transmission electron microscopy, X-ray diffraction and thermogravimetric analysis. The results indicate that the composites exhibit good nanofibrous morphology with MnO nanoparticles uniformly encapsulated by carbon nanofibers. The hybrid nanofiber composites are used directly as freestanding anodes for lithium-ion batteries to evaluate their electrochemical properties. It is found that the optimized MnO-carbon nanofiber composite can deliver a high reversible capacity of 663 mAh g−1, along with excellent cycling stability and good rate capability. The superior performance enables the composites to be promising candidates as an anode alternative for high-performance lithium-ion batteries

  11. 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

  12. 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)

  13. Irradiation effect of carbon negative-ion implantation on polytetrafluoroethylene for controlling cell-adhesion property

    Science.gov (United States)

    Sommani, Piyanuch; Tsuji, Hiroshi; Kojima, Hiroyuki; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo; Takaoka, Gikan H.

    2010-10-01

    We have investigated the irradiation effect of negative-ion implantation on the changes of physical surface property of polytetrafluoroethylene (PTFE) for controlling the adhesion property of stem cells. Carbon negative ions were implanted into PTFE sheets at fluences of 1 × 10 14-1 × 10 16 ions/cm 2 and energies of 5-20 keV. Wettability and atomic bonding state including the ion-induced functional groups on the modified surfaces were investigated by water contact angle measurement and XPS analysis, respectively. An initial value of water contact angles on PTFE decreased from 104° to 88° with an increase in ion influence to 1 × 10 16 ions/cm 2, corresponding to the peak shifting of XPS C1s spectra from 292.5 eV to 285 eV with long tail on the left peak-side. The change of peak position was due to decrease of C-F 2 bonds and increase of C-C bonds with the formation of hydrophilic oxygen functional groups of OH and C dbnd O bonds after the ion implantation. After culturing rat mesenchymal stem cells (MSC) for 4 days, the cell-adhesion properties on the C --patterned PTFE were observed by fluorescent microscopy with staining the cell nuclei and their actin filament (F-actin). The clear adhesion patterning of MSCs on the PTFE was obtained at energies of 5-10 keV and a fluence of 1 × 10 15 ions/cm 2. While the sparse patterns and the uncontrollable patterns were found at a low fluence of 3 × 10 14 ions/cm 2 and a high fluence of 3 × 10 15 ions/cm 2, respectively. As a result, we could improve the surface wettability of PTFE to control the cell-adhesion property by carbon negative-ion implantation.

  14. Determination of total dissolved inorganic carbon in freshwaters by reagent-free ion chromatography.

    Science.gov (United States)

    Polesello, Stefano; Tartari, Gabriele; Giacomotti, Paola; Mosello, Rosario; Cavalli, Silvano

    2006-06-16

    Studies of inorganic carbon cycle in natural waters provide important information on the biological productivity and buffer capacity. Determination of total inorganic carbon, alkalinity and dissolved carbon dioxide gives an indication of the balance between photosynthesis and respiration by biota, both within the water column and sediments, and carbon dioxide transfers from the water column to the atmosphere. There are few methods to measure and distinguish the different forms of inorganic carbon, but all require a measure or an indirect quantification of total inorganic carbon. A direct measurement of TIC in water is made possible by the introduction of electrolytic generated hydroxide eluent in ion chromatography which allows to detect a chromatographic peak for carbonate. The advantage of this method is that all the inorganic forms of carbon are converted in carbonate at eluent pH and can be detected as a single peak by conductivity detection. Repeatability of carbonate peak was evaluated at different levels from 0.02 to 6 mequiv.l(-1) both in high purity water and in real samples and ranged from 1 to 9%. The calibration curve was not linear and has to be fitted by a quadratic curve. Limit of detection was estimated to be 0.02 mequiv.l(-1). Accuracy has been estimated by comparing ion chromatography method with total inorganic carbon calculated from alkalinity and pH. The correlation between the two methods was good (R(2)=0.978, n=141). The IC method has been applied to different typologies of surface waters (alpine and subalpine lakes and rivers) characterised by different chemical characteristics (alkalinity from 0.05 to 2 mequiv.l(-1) and pH from 6.7 to 8.5) and low total organic carbon concentrations. This analytical method allowed to describe the distribution of TIC along the water column of two Italian deep lakes. PMID:16620857

  15. Coaxial carbon/metal oxide/aligned carbon nanotube arrays as high-performance anodes for lithium ion batteries.

    Science.gov (United States)

    Lou, Fengliu; Zhou, Haitao; Tran, Trung Dung; Melandsø Buan, Marthe Emelie; Vullum-Bruer, Fride; Rønning, Magnus; Walmsley, John Charles; Chen, De

    2014-05-01

    Coaxial carbon/metal oxide/aligned carbon nanotube (ACNT) arrays over stainless-steel foil are reported as high-performance binder-free anodes for lithium ion batteries. The coaxial arrays were prepared by growth of ACNTs over stainless-steel foil followed by coating with metal oxide and carbon. The carbon/manganese oxide/ACNT arrays can deliver an initial capacity of 738 mAh g(-1) with 99.9 % capacity retention up to 100 cycles and a capacity of 374 mAh g(-1) at a high current density of 6000 mA g(-1). The external carbon layer was recognized as a key component for high performance, and the mechanism of performance enhancement was investigated by electrochemical impedance spectroscopy, electron microscopy, and X-ray diffraction analysis. The layer increases rate capability by enhancing electrical conductivity and maintaining a low mass-transfer resistance and also improves cyclic stability by avoiding aggregation of metal-oxide particles and stabilizing the solid electrolyte interface. The resultant principle of rational electrode design was applied to an iron oxide-based system, and similar improvements were found. These coaxial nanotube arrays present a promising strategy for the rational design of high-performance binder-free anodes for lithium ion batteries. PMID:24578068

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

    International Nuclear Information System (INIS)

    A thermodynamic study of uranyl ion complexes formation with different macrocyclic ligands was realized in propylene carbonate as solvent using spectrophotometric and potentiometric techniques. Formation kinetics of two UO2 complexes: a crown ether (18C6) and a coronand (22) was studied by spectrophotometry in propylene carbonate with addition of tetraethylammonium chlorate 0.1M at 250C. Possible structures of complexes in solution are discussed

  17. 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.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-07-01

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

  20. 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

  1. Blister formation in tungsten by hydrogen and carbon mixed ion beam irradiation

    International Nuclear Information System (INIS)

    Blister formation in tungsten has been studied by mixed carbon and hydrogen ion beam irradiation. The beam ion energies were 1.0 keV and 300 eV, and the fluence was in the range of 1024-1025 ions m-2. It was found that a little amount of carbon impurity in the beam affected blister formation. A large number of blisters with various sizes were observed on the surface of tungsten at 653 K when the carbon concentration was more than 0.35%. When the carbon concentration was 0.11%, no blisters larger than 1.0 μm were observed. When the carbon concentration was 2.35%, a carbon layer developed on the tungsten surface, and again, no blisters were observed. The effect of target temperature on blister formation was also investigated: the sizes and numbers of the blisters were the largest when the tungsten was irradiated at 653 K; when the sample was irradiated at 388 or 873 K, no blisters larger than 1.0 μm were observed

  2. 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.

  3. Thin film Li-Ion batteries with carbon anode

    Czech Academy of Sciences Publication Activity Database

    Merta, J.; Bludská, Jana; Jakubec, Ivo

    Brno: University of Technology Brno, 2003, s. 37-40. ISBN 80-214-2298-X. [Advanced Batteries and Accumulators /4./. Brno (CZ), 15.06.2003-19.06.2003] Institutional research plan: CEZ:AV0Z4032918 Keywords : carbon anode Subject RIV: CA - Inorganic Chemistry

  4. Generation of MeV carbon and fluorine ions by subnanosecond laser pulses

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Velyhan, Andriy; Jungwirth, Karel; Krouský, Eduard; Láska, Leoš; Rohlena, Karel; Pfeifer, Miroslav; Ullschmied, Jiří

    Paris : European Physical Society, 2008 - (Lalousis, P.; Moustaizis, S.), P4.133/1-P4.133/4 ISBN 2-914771-52-5. - (ECA. 32D). [EPS Plasma Physics Conference /35./. Hersonissos (GR), 09.06.2008-13.06.2008] R&D Projects: GA MŠk(CZ) LC528; GA AV ČR IAA100100715 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser ion sources * carbon ions * fluorine ions * effective accelerating voltage Subject RIV: BH - Optics, Masers, Lasers

  5. Optical and Scratch Resistant Properties of Diamondlike Carbon Films Deposited with Single and Dual Ion Beams

    Science.gov (United States)

    Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

    1993-01-01

    Amorphous diamond-like carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance, frictional, and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

  6. 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

    Purpose: To investigate for the first time the dosimetric properties of a new commercial synthetic diamond detector (PTW microDiamond) in high-energy scanned clinical carbon ion beams generated by a synchrotron at the CNAO facility. Methods: The detector response was evaluated in a water phantom with actively scanned carbon ion beams ranging from 115 to 380 MeV/u (30–250 mm Bragg peak depth in water). Homogeneous square fields of 3 × 3 and 6 × 6 cm{sup 2} were used. Short- and medium-term (2 months) detector response stability, dependence on beam energy as well as ion type (carbon ions and protons), linearity with dose, and directional and dose-rate dependence were investigated. The depth dose curve of a 280 MeV/u carbon ion beam, scanned over a 3 × 3 cm{sup 2} area, was measured with the microDiamond detector and compared to that measured using a PTW Advanced Markus ionization chamber, and also simulated using FLUKA Monte Carlo code. The detector response in two spread-out-Bragg-peaks (SOBPs), respectively, centered at 9 and 21 cm depths in water and calculated using the treatment planning system (TPS) used at CNAO, was measured. Results: A negligible drift of detector sensitivity within the experimental session was seen, indicating that no detector preirradiation was needed. Short-term response reproducibility around 1% (1 standard deviation) was found. Only 2% maximum variation of microDiamond sensitivity was observed among all the evaluated proton and carbon ion beam energies. The detector response showed a good linear behavior. Detector sensitivity was found to be dose-rate independent, with a variation below 1.3% in the evaluated dose-rate range. A very good agreement between measured and simulated Bragg curves with both microDiamond and Advanced Markus chamber was found, showing a negligible LET dependence of the tested detector. A depth dose curve was also measured by positioning the microDiamond with its main axis oriented orthogonally to the beam

  7. B and N ion implantation into carbon nanotubes: Insight from atomistic simulations

    International Nuclear Information System (INIS)

    By employing atomistic computer simulations with empirical potential and density functional force models, we study B/N ion implantation onto carbon nanotubes. We simulate irradiation of single-walled nanotubes with B and N ions and show that up to 40% of the impinging ions can occupy directly the sp2 positions in the nanotube atomic network. We further estimate the optimum ion energies for direct substitution. Ab initio simulations are used to get more insight into the structure of the typical atomic configurations which appear under the impacts of the ions. As annealing should further increase the number of sp2 impurities due to dopant atom migration and annihilation with vacancies, we also study migration of impurity atoms over the tube surface. Our results indicate that irradiation-mediated doping of nanotubes is a promising way to control the nanotube electronic and even mechanical properties due to impurity-stimulated crosslinking of nanotubes

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

    International Nuclear Information System (INIS)

    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

  9. 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

  10. Beam test of compact ECR ion source for carbon therapy

    International Nuclear Information System (INIS)

    Ion source for medical facilities should have characteristics of easy maintenance, low electric power, good stability and long operation time without maintenance (one year or more). Based on the proto type compact source, a 10 GHz compact ECR ion source with all permanent magnets has been developed. Peaks of the mirror magnetic field along the beam axis are 0.59 T at the extraction side and 0.87 T at the gas injection side, respectively, while the minimum B strength is 0.25 T. The source has a diameter of 320 mm and a length of 295 mm. The result of beam tests shows that a C4+ intensity of 530 μA was obtained under an extraction voltage of 45 kV. This paper describes the design detail and the experimental results for the new source. (author)

  11. 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

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

    International Nuclear Information System (INIS)

    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 BaF2 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 the

  13. 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.

  14. V2O5/Mesoporous Carbon Composite as a Cathode Material for Lithium-ion Batteries

    International Nuclear Information System (INIS)

    ABSTRACT: V2O5/mesoporous carbon composite has been prepared by an ultrasonically assisted method followed by a sintering process. The as-prepared V2O5/mesoporous carbon material containing 90 wt% V2O5 shows better electrochemical performance, with capacity of 163 mA h g−1 after 100 cycles at the current density of 500 mA g−1, as well as better charge/discharge rate capability for lithium storage than V2O5 nanoparticles. The improved electrochemical performance indicates that the V2O5/mesoporous carbon composite could be used as a promising cathode material for lithium ion batteries

  15. Development of an electrohydrodynamic ion-drag micropump using three-dimensional carbon micromesh electrodes

    International Nuclear Information System (INIS)

    An electrohydrodynamic (EHD) ion-drag micropump using three-dimensional carbon micromesh electrodes was developed. The carbon micromesh electrodes were created by the pyrolysis of SU-8 structures. The carbon electrodes and microchannel were formed on a quartz substrate, and the microchannel was sealed by an SU-8 slab structure. The pumping behaviors were evaluated using Fluorinert as a non-conductive sample solution. The maximum pressure and volume flow rate were approximately 23 Pa and 400 nL/min, respectively, under an applied voltage of 500 V. (paper)

  16. 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

  17. 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

  18. 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

  19. Ion exclusion by sub-2-nm carbon nanotube pores

    OpenAIRE

    Fornasiero, Francesco; Park, Hyung Gyu; Holt, Jason K.; Stadermann, Michael; Grigoropoulos, Costas P.; Noy, Aleksandr; Bakajin, Olgica

    2008-01-01

    Biological pores regulate the cellular traffic of a large variety of solutes, often with high selectivity and fast flow rates. These pores share several common structural features: the inner surface of the pore is frequently lined with hydrophobic residues, and the selectivity filter regions often contain charged functional groups. Hydrophobic, narrow-diameter carbon nanotubes can provide a simplified model of membrane channels by reproducing these critical features in a simpler and more robu...

  20. CoSn/carbon composite nanofibers for applications as anode in lithium-ion batteries

    International Nuclear Information System (INIS)

    CoSn/carbon composite nanofibers were prepared by electrospinning followed by heat treatment. Uniform morphologies and microstructures were observed by scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray diffraction. The results demonstrated that well-dispersed nanoparticles of CoSn intermetallic compound and Sn with diameter of about 30–50 nm embedded in carbon nanofibers were prepared after carbonization at 850 °C. Compared with pure carbon nanofibers without the nanoparticles, CoSn/carbon composite nanofibers showed a high reversible capacity and excellent cycling performance, resulting from the formation of CoSn intermetallic nanoparticles and buffering by the carbon nanofiber matrix. The nanofiber mats with good flexibility were utilized as anodes in lithium-ion batteries, and the CoSn/carbon composite nanofibers exhibited a good fibrous morphology after the discharge/charge processes. Results indicated that electrospinning could be a feasible method to prepare Co–Sn–C composite nanofibers as anodes in lithium-ion batteries

  1. CoSn/carbon composite nanofibers for applications as anode in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Weili; Luo, Chenghao; Li, Yu; Feng, Yiyu; Feng, Wei, E-mail: weifeng@tju.edu.cn; Zhao, Yunhui; Yuan, Xiaoyan, E-mail: yuanxy@tju.edu.cn [Tianjin University, School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials (China)

    2013-09-15

    CoSn/carbon composite nanofibers were prepared by electrospinning followed by heat treatment. Uniform morphologies and microstructures were observed by scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray diffraction. The results demonstrated that well-dispersed nanoparticles of CoSn intermetallic compound and Sn with diameter of about 30-50 nm embedded in carbon nanofibers were prepared after carbonization at 850 Degree-Sign C. Compared with pure carbon nanofibers without the nanoparticles, CoSn/carbon composite nanofibers showed a high reversible capacity and excellent cycling performance, resulting from the formation of CoSn intermetallic nanoparticles and buffering by the carbon nanofiber matrix. The nanofiber mats with good flexibility were utilized as anodes in lithium-ion batteries, and the CoSn/carbon composite nanofibers exhibited a good fibrous morphology after the discharge/charge processes. Results indicated that electrospinning could be a feasible method to prepare Co-Sn-C composite nanofibers as anodes in lithium-ion batteries.

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

    Science.gov (United States)

    Prasad, Bhim Bali; Jauhari, Darshika

    2015-05-22

    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(-1) for Ce(IV) and 0.19 ng mL(-1) for Gd(III) (S/N=3) that could eventually be helpful for lanthanide estimation at stringent levels. PMID:25937109

  3. Histological study of choroidal malignant melanoma treated by carbon ion radiotherapy

    International Nuclear Information System (INIS)

    The purpose of this study was to report, we believe for the first time, a histological study of choroidal malignant melanoma treated by carbon ion beam radiotherapy. A 75-year-old Japanese man was diagnosed as having a choroidal melanoma after undergoing magnetic resonance imaging (MRI). Positron emission tomography (PET) revealed a hot spot in the same location as the intraocular mass seen in MRI. Carbon ion radiotherapy was performed with a total dose of 77 Gy, and the hot spot seen by PET disappeared completely. At 15 months after carbon ion therapy, the eye had to be enucleated because of uncontrollable ocular hypertension. It was examined histologically in serial sections. A large tumor mass (15 x 12 mm) with high pigmentation was found in the vitreous space. Almost all tumor cells showed necrosis in every section. A small number of intact tumor cells were present at the periphery. The overlying retina did not show any necrosis, but showed mild to moderate gliosis. No intraretinal hemorrhage, lipid deposit, or protein exudate was apparent. Almost all tumor cells showed necrosis after radiotherapy with a carbon ion beam. However, the effect on the adjacent tissues was determined as minimal in histological analysis. (author)

  4. 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

  5. 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.

  6. 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.

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

    Science.gov (United States)

    Böhlen, T T; Cerutti, F; Dosanjh, M; Ferrari, A; Gudowska, I; Mairani, A; Quesada, J M

    2010-10-01

    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 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. PMID:20844337

  8. Carbon ion beam focusing using laser irradiated heated diamond hemispherical shells

    Energy Technology Data Exchange (ETDEWEB)

    Offermann, Dustin T [Los Alamos National Laboratory; Flippo, Kirk A [Los Alamos National Laboratory; Gaillard, Sandrine A [Los Alamos National Laboratory

    2009-01-01

    Experiments preformed at the Los Alamos National Laboratory's Trident Laser Facility were conducted to observe the acceleration and focusing of carbon ions via the TNSA mechanism using hemispherical diamond targets. Trident is a 200TW class laser system with 80J of 1 {micro}m, short-pulse light delivered in 0.5ps, with a peak intensity of 5 x 10{sup 20} W/cm{sup 2}. Targets where Chemical Vapor Deposition (CVD) diamonds formed into hemispheres with a radius of curvature of 400{micro}m and a thickness of 5{micro}m. The accelerated ions from the hemisphere were diagnosed by imaging the shadow of a witness copper mesh grid located 2mm behind the target onto a film pack located 5cm behind the target. Ray tracing was used to determine the location of the ion focal spot. The TNSA mechanism favorably accelerates hydrogen found in and on the targets. To make the carbon beam detectable, targets were first heated to several hundred degrees Celsius using a CW, 532nm, 8W laser. Imaging of the carbon beam was accomplished via an auto-radiograph of a nuclear activated lithium fluoride window in the first layer of the film pack. The focus of the carbon ion beam was determined to be located 630 {+-} 110 {micro}m from the vertex of the hemisphere.

  9. Reduction of friction and wear by ion-implanted carbonized photoresist

    International Nuclear Information System (INIS)

    The influence of ion-implanted carbonized photoresist layers (AZ 5210) on wear and friction is discussed in this paper. Photoresist, an organic resin, was used because of the simplicity of coating the sample, accurate control of the layer thickness, and high amount of carbon. The samples investigated were coated by conventional spin-on techniques with layer thicknesses varying from 0.2 μm to 2.2μm. Subsequent ion bombardment at energies of 200 keV and 1.4 MeV with doses ranging from 1x1016 cm-2 to 1x1017 cm-2 caused carburization, densification, and a mixing of the layer with the steel substrate. Transmission electron microscopy investigations, Raman spectroscopy, elastic recoil detection analysis, and microhardness measurements confirmed the production of a hard, amorphous, hydrogen-containing (about 17%) carbon layer after implantation. The layers were deposited onto different steels (AISI 52100, AISI 440 B unhardened, and AISI M2) and after implantation of boron, aluminium, phosphorus, arsenic and titanium, showed a strongly reduced friction coefficient (lower than 0.2) and drastically reduced wear behaviour. The duration of the wear reduction depended on both the thickness of the carbonized photoresist layer and on the implanted ion dose. Doses of 5x1016 cm-2 for hard steels and doses of 1x1017 cm-2 for soft steels are necessary to produce a sufficient layer adhesion by ion beam mixing. (orig.)

  10. Enhanced wear resistance of production tools and steel samples by implantation of nitrogen and carbon ions

    International Nuclear Information System (INIS)

    In recent years ion implantation has become a feasible technique for obtaining improved wear resistance of production tools. However, basic knowledge of how and in which cases ion implantation is working at its best is still needed. The present paper discusses structural and tribological investigations of carbon and nitrogen implanted steels. The nitrogen data were obtained mainly from field tests and the investigation of carbon implantations took place mainly in the laboratory. A study was made of how the tribological behaviour of implanted steels changes with different implantation parameters. The tribological laboratory investigations were carried out using pin-on-disc equipment under controlled test conditions, and deal with high dose carbon implantation (approximately (1-2)x1018 ions cm-2). The wear resistance of steels was enhanced dramatically, by up to several orders of magnitude. The field test results cover a broad range of ion implanted production tools, which showed a marked improvement in wear resistance. Nitrogen implanted tools are also compared with carbon and titanium implanted tools. (orig.)

  11. 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

  12. Wafer-scale synthesis of multi-layer graphene by high-temperature carbon ion implantation

    International Nuclear Information System (INIS)

    We report on the synthesis of wafer-scale (4 in. in diameter) high-quality multi-layer graphene using high-temperature carbon ion implantation on thin Ni films on a substrate of SiO2/Si. Carbon ions were bombarded at 20 keV and a dose of 1 × 1015 cm−2 onto the surface of the Ni/SiO2/Si substrate at a temperature of 500 °C. This was followed by high-temperature activation annealing (600–900 °C) to form a sp2-bonded honeycomb structure. The effects of post-implantation activation annealing conditions were systematically investigated by micro-Raman spectroscopy and transmission electron microscopy. Carbon ion implantation at elevated temperatures allowed a lower activation annealing temperature for fabricating large-area graphene. Our results indicate that carbon-ion implantation provides a facile and direct route for integrating graphene with Si microelectronics

  13. 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.

  14. 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.

  15. 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)

  16. 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

  17. Effects of Mo ion implantation on rolling contact fatigue behavior of carbon steel

    International Nuclear Information System (INIS)

    Rolling Contact Fatigue (RCF) is one of the most serious material surface damage problems encountered by many critical components, especially in ball-bearing applications. RCF is sensitive to the material strength, hardness, surface morphology, microstructure and stress status, which may be dramatically changed by surface modifications. In present work, the surface modification of molybdenum ion implantation into quenched carbon steel was employed, and RCF tests on the implanted specimens, as well as the unimplanted, were performed. It was found out that carbon steel specimens, with and without ion implantation, have the same fatigue damage characteristics. They both have circular and fan-like pits on the fatigue failed surfaces, with many spherical debris existing in the fan-like pits. However, molybdenum ion implantation reduced the rolling contact fatigue life of quenched carbon steel. The possible reasons are the following: the ion beam current is too large, which causes the specimen to undergo the annealing process and soften during the implantation process; the incident angles of ions are different for different spots of curve specimen surface, which causes the uneven distribution of residual stress. These will promote the crack initiation and propagation

  18. 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)

  19. Development of compact ECR ion source for carbon therapy facility

    International Nuclear Information System (INIS)

    A 10 GHz compact Electron Cyclotron Resonance (ECR) ion source with all permanent magnets has been developed. Peaks of the mirror magnetic field along the beam axis are 0.59 T at the extraction side and 0.87 T at the gas injection side, respectively, while the minimum B strength is 0.25 T. The source has a diameter of 320 mm and a length of 295 mm. The result of beam tests shows that a C4+ intensity of 500 μA was obtained under an extraction voltage of 30 kV. This paper describes the design detail and the experimental results for the new source. (author)

  20. Self-organized formation of metal-carbon nanostructures by hyperthermal ion deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hannstein, I.K.

    2006-04-26

    The quasi-simultaneous deposition of mass-selected hyperthermal carbon and metal ions results in a variety of interesting film morphologies, depending on the metal used and the deposition conditions. The observed features are of the order of a few nanometres and are therefore interesting for future potential applications in the various fields of nanotechnology. The present study focuses on the structural analysis of amorphous carbon films containing either copper, silver, gold, or iron using amongst others Rutherford Backscattering Spectroscopy, High Resolution Transmission Electron Microscopy, and Energy Dispersive X-Ray Spectroscopy. The film morphologies found are as follows: copper-containing films consist of copper nanoclusters with sizes ranging from about 3 to 9 nm uniformly distributed throughout the amorphous carbon matrix. The cluster size hereby rises with the copper content of the films. The silver containing films decompose into a pure amorphous carbon film with silver agglomerates at the surface. Both, the gold- and the iron-containing films show a multilayer structure of metal-rich layers with higher cluster density separated by metal-depleted amorphous carbon layers. The layer distances are of the order of up to 15 nm in the case of gold-carbon films and 7 nm in the case of iron-carbon films. The formation of theses different structures cannot be treated in the context of conventional self-organization mechanisms basing upon thermal diffusion and equilibrium thermodynamics. Instead, an ion-induced atomic transport, sputtering effects, and the stability of small metal clusters were taken into account in order to model the structure formation processes. A similar multilayer morphology was recently also reported in the literature for metal-carbon films grown by magnetron sputtering techniques. In order to investigate, whether the mechanisms are the same as in the case of the ion beam deposited films described above, first experiments were conducted

  1. Sorption of uranium and thorium ions from nitric acid solution using HDEHP-Impregnated activated carbon

    International Nuclear Information System (INIS)

    Equilibrium measurements on the sorption of uranium and thorium ions from nitric acid solutions using di(2-ethyl hexyl) phosphoric (HDEHP) impregnated activated carbon have been done using batch technique. Experimental isotherms, Ferundlish, and Dubinin-Radushkevich (D-R) isotherm models. Of the models tested, D-R expression was found to represent the isotherms of both ions better over Th entire concentration range investigated than either Langmuir or Freundlish model. The changes in standard thermodynamic quantities (viz. Δ H, Δ S, and Δ G) were calculated and the maximum adsorption capacity of HDEHP impregnated carbon together with the mean free energy of both studied ions were determined using D-R approach

  2. 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.)

  3. 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

  4. Investigation of response of CR-39, PM-355 and PM-500 types of nuclear track detectors to energetic carbon ions

    CERN Document Server

    Szydlowski, A; Jaskola, M; Sadowski, M; Korman, A; Kedzierski, J T; Kretschmer, W

    1999-01-01

    Samples of CR-39, PM-355, and PM-500 plastic detectors were irradiated with carbon ions of energy ranging from 0.9 MeV to 14.7 MeV. After the irradiation the detector samples were etched for a period from 2 hrs to 10 hrs. Dependence of track diameters on the ion energy values for different etching times, and dependence of V sub T /V sub B as a function of incident carbon-ion energy, are presented.

  5. Calibration of BAS-TR image plate response to high energy (3-300 MeV) carbon ions

    Science.gov (United States)

    Doria, D.; Kar, S.; Ahmed, H.; Alejo, A.; Fernandez, J.; Cerchez, M.; Gray, R. J.; Hanton, F.; MacLellan, D. A.; McKenna, P.; Najmudin, Z.; Neely, D.; Romagnani, L.; Ruiz, J. A.; Sarri, G.; Scullion, C.; Streeter, M.; Swantusch, M.; Willi, O.; Zepf, M.; Borghesi, M.

    2015-12-01

    The paper presents the calibration of Fuji BAS-TR image plate (IP) response to high energy carbon ions of different charge states by employing an intense laser-driven ion source, which allowed access to carbon energies up to 270 MeV. The calibration method consists of employing a Thomson parabola spectrometer to separate and spectrally resolve different ion species, and a slotted CR-39 solid state detector overlayed onto an image plate for an absolute calibration of the IP signal. An empirical response function was obtained which can be reasonably extrapolated to higher ion energies. The experimental data also show that the IP response is independent of ion charge states.

  6. 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...

  7. Adsorption of Cd(II and Pb(II Ions from Aqueous Solution byActivated Carbon

    Directory of Open Access Journals (Sweden)

    Hayder Mohammed Abdul-Hameed

    2009-01-01

    Full Text Available Heavy metal consider as major environmental pollutants. Many of industrial wastewater effluents contain a wide range of these heavy metals. The adsorption of Cd2+ and Pb2+ metal ions from aqueous solution by activated carbon was studied. The results showed that maximum adsorption capacity occurred at 486.9×10-3 mg/kg for Pb2+ ion and 548.8×10-3 mg/kg for Cd2+ ion. The adsorption in a mixture of the metal ions had a balancing effect on the adsorption capacity of the activated carbon. The adsorption capacity of each metal ion was affected by the presence of other metal ions rather than its presence individually. The study showed the presence of other heavy metals attribute to the reduction in the activated carbon capacity, and the adsorption process was found to obeys the Freundlich isotherm for both ions.

  8. Removal of Heavy Metal Ions with Acid Activated Carbons Derived from Oil Palm and Coconut Shells

    Directory of Open Access Journals (Sweden)

    Mokhlesur M. Rahman

    2014-05-01

    Full Text Available In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II, lead(II and chromium(VI. Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hydrated iron oxide. The adsorption equilibrium data for nickel(II and lead(II were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II and lead(II. The removal of chromium(VI was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II, Pb(II and Cr(VI by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model.

  9. 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.

  10. 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.

  11. Etoile: Rhone-Alpes project for carbon-ion treatment of radioresistant tumours

    International Nuclear Information System (INIS)

    Hadron-therapy using carbon ions appears to be very efficient for the treatment of tumours, due to its ballistic precision and to its biological effects that are much higher than in the case of conventional radiotherapy. The experience gained in experimental facilities in Japan (HIMAC) and Germany (GSI) shows that carbon beams provide both efficiency and tolerance and then are the most promising tool for a rapid increase of the recovery rate in the treatment of radioresistant tumours. Dedicated centres using carbon ions will start operation in 2002 in Hyogo (Japan) and in 2005 in Heidelberg (Germany), and each of them will treat about 1000 patients per year. We give here a short description of the project ETOILE to be built in Lyon. The technical proposal will be available beginning of 2002. (authors)

  12. Compact ECR ion source with permanent magnets for carbon therapy

    International Nuclear Information System (INIS)

    Ion sources for the medical facilities should have the following characteristics of easy maintenance, low electric power, good stability, and long operation time without trouble (1 year or longer). For this, a 10 GHz compact electron cyclotron resonance ion source (ECRIS) with all permanent magnets was developed. The beam intensity and stability for C4+ were 280 e μA and better than 6% during 20 h with no adjustment of any source parameters. These results were acceptable for the medical requirements. Recently, many plans were proposed to construct the next generation cancer treatment facility. For such a facility we have designed an all permanent magnet ECRIS, in which a high magnetic field is chosen for increasing the beam intensity. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas injection side, while the minimum B strength is 0.25 T. The source has a diameter of 32 cm and a length of 29.5 cm. Details of the design of this source and its background are described in this article

  13. Track structure of carbon ions: measurements and simulations.

    Science.gov (United States)

    Conte, V; Colautti, P; Moro, D; Grosswendt, B

    2014-10-01

    The likelihood of radiation to produce clustered damages in irradiated biological tissue and the reparability of such damages are closely related to the stochastics of localised ionising interactions within small volumes of nanometre sizes, determined by the particle track structure. Track structure investigations in nanometre-sized volumes have been subject of research for several decades, mainly by means of Monte Carlo simulations. Today, the 'track-nanodosimeter', installed at the TANDEM-ALPI accelerator complex of LNL, is a measuring device able to count the electrons produced in a 20-nm equivalent sensitive site (De Nardo et al. A detector for track-nanodosimetry. Nucl. Instrum. Methods. Phys. Res. A 484: , 312-326 (2002)). It allows studying track structure properties both in the near neighbourhood of a primary particle trajectory and separately in the penumbra region. An extended study for different ionising particles of medical interest has been recently performed with the track-nanodosimeter (Conte et al. Track structure of light ions: experiments and simulations. New J. Phys. 14: , 093010, (2012)). Here, new experimental data and results of Monte Carlo simulations for 240- and 96-MeV (12)C-ions are presented and discussed. PMID:24249779

  14. Preparation of re-constructed carbon nanosheet powders and their efficient lithium-ion storage mechanism

    International Nuclear Information System (INIS)

    Highlights: • Novel folding re-constructed carbon nanosheet powders (re-CNSs) with unique microstructure and higher lithium-ion storage capacity than prototype graphite powders are prepared. • The wrinkles on the surface of the re-CNSs play an important role on the enhanced lithium-ions storage and provide a new way to improve the capacity of anode materials for lithium ion batteries (LIBs). • A dislocation mechanism is used to describe the role of the wrinkles for the enhanced lithium-ion storage. - Abstract: Based on the re-construction idea of carbon nanomaterials, novel folding re-constructed carbon nanosheets (re-CNSs) with unique microstructure and higher lithium-ion storage capacity than prototype graphite powders are prepared. The nanoscale carbon-fragment suspension is firstly prepared through a successive chemical oxidation of graphite and ultrasonic crushing operation, and the re-CNS powders are then obtained by spray drying the suspension and a subsequent high-temperature reducing process. The as-prepared re-CNSs exhibit a folding appearance with a width of several micrometers, with a maximum initial specific capacity of 903 mAh g−1 for the re-CNSs sample thermally reduced at 500 °C (re-CNSs500). After 100 cycles, the reversible capacity is maintained at about 400 mAh g−1 for the re-CNSs500. The abundant carboxylic and hydroxide groups, edges, and defective sites of individual graphite oxide fragments facilitate the dislocation formation in the re-CNSs. In addition, a dislocation mechanism is thus used to describe the enhanced lithium-ion storage

  15. 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)

  16. Nuclear point mass effects in the interaction of energetic ion with carbon nanotubes

    Science.gov (United States)

    Zheng, Li-Ping; Yan, Long; Zhu, Zhi-Yong; Ma, Guo-Liang

    2016-03-01

    We have calculated deposited energies of various energetic ions in carbon nanotubes, to study nuclear point mass effects, with the help of a static Monte Carlo (MC) simulation program. As a result of nuclear point mass effects, we show that at the same incident energy, the ion-deposited energy maximizes, while its mass has intermediate mass values, such as 11B, 12C and 14N ion masses, under hundreds keV 4He, 11B, 12C, 14N, 20Ne, 28Si and 40Ar ion irradiations of a thin-walled carbon nanotube. We also show that at the same incident energy, the coordination defect number maximizes, while its mass has an intermediate mass (20Ne) value, under hundreds keV 4He, 20Ne and 40Ar ion irradiations of the thin-walled nanotube. We derive an ion-deposited energy formula to analyze these maximum phenomena, and compare the MC simulation results with the MD (molecular dynamics) ones.

  17. 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)

  18. 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.

  19. 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.

  20. 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.

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

    International Nuclear Information System (INIS)

    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−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−1 for Ce(IV) and 0.19 ng mL−1 for Gd(III) (S/N = 3) that could eventually be helpful for lanthanide estimation at stringent levels

  2. Experimental investigations on carbon ion scanning radiography using a range telescope.

    Science.gov (United States)

    Rinaldi, I; Brons, S; Jäkel, O; Voss, B; Parodi, K

    2014-06-21

    Ion beams offer an excellent tumor-dose conformality due to their inverted depth-dose profile and finite range in tissue, the Bragg peak (BP). However, they introduce sensitivity to range uncertainties. Imaging techniques play an increasingly important role in ion beam therapy to support precise diagnosis and identification of the target volume at the planning stage as well as to ensure the correspondence between the planning and treatment situation at the actual irradiation. For the purpose of improved treatment quality, ion-based radiographic images could be acquired at the treatment site before or during treatment and be employed to monitor the patient positioning and to check the patient-specific ion range. This work presents the initial experimental investigations carried out to address the feasibility of carbon ion radiography at the Heidelberg ion therapy center using a prototype range telescope set-up and an active raster scanning ion beam delivery system. Bragg curves are measured with a stack of ionization chambers (IC) synchronously to the beam delivery. The position of the BP is extracted from the data by locating the channel of maximum current signal for each delivered beam. Each BP is associated to the lateral and vertical positions of the scanned raster point extrapolated from the beam monitor system to build up a radiography. The radiographic images are converted into water equivalent thickness (WET) based on two calibrations of the detector. Radiographies of two phantoms of different complexities are reconstructed and their image quality is analyzed. A novel method proposed to increase the nominal range resolution of the IC stack is applied to the carbon ion radiography of an Alderson head phantom. Moreover, an x-ray digitally reconstructed radiography of the same anthropomorphic head phantom is converted in WET through the clinically used ion range calibration curve and compared with the carbon ion radiography based on a γ-index approach

  3. Track structure of carbon ions: measurements and simulations

    International Nuclear Information System (INIS)

    The likelihood of radiation to produce clustered damages in irradiated biological tissue and the reparability of such damages are closely related to the stochastics of localised ionising interactions within small volumes of nanometre sizes, determined by the particle track structure. Track structure investigations in nanometre-sized volumes have been subject of research for several decades, mainly by means of Monte Carlo simulations. Today, the 'track-nano-dosimeter', installed at the TANDEM-ALPI accelerator complex of LNL, is a measuring device able to count the electrons produced in a 20-nm equivalent sensitive site (De Nardo et al. A detector for track-nanodosimetry. Nucl. Instrum. Methods. Phys. Res. A 484, 312-326 (2002)). It allows studying track structure properties both in the near neighbourhood of a primary particle trajectory and separately in the penumbra region. An extended study for different ionising particles of medical interest has been recently performed with the track-nano-dosimeter (Conte et al. Track structure of light ions: experiments and simulations. New J. Phys. 14, 093010, (2012)). Here, new experimental data and results of Monte Carlo simulations for 240- and 96-MeV 12C-ions are presented and discussed. In conclusion, it can be stated that the shape of the ionisation cluster-size distributions in the track-core region of particles' tracks results to be mainly determined by the mean free ionisation-path length of the primary particles. In the penumbra region, the shape of the distributions is almost independent of the impact parameter and also of the particle type and velocity. The probability of target hits changes with the quality of the primary particles, but the hit target experiences the same ionisation clustering, irrespectively of particle type and velocity. The relative frequency of target hits results to be proportional to the mean number of ionizations produced by the primary particle along a path length D. (authors)

  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. 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...

  7. Interaction of Li{sup +} ions with ethylene carbonate (EC): Density functional theory calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bhatt, Mahesh Datt; Cho, Maenghyo [WCU Multiscale Mechanical Design Division, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Cho, Kyeongjae, E-mail: kjcho@utdallas.edu [WCU Multiscale Mechanical Design Division, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Department of Materials Science and Engineering and Department of Physics, University of Texas at Dallas, Richardson, TX 75080 (United States)

    2010-12-15

    Electronic structures of Li{sup +} ion-ethylene carbonate (EC) complexes were studied by density functional theory. The structural, electronic and dynamical properties of Li{sup +}-EC complexes were studied for both an isolated EC molecule and clusters including Li{sup +} ion. Our structural analysis showed only one type of Li{sup +} coordination with EC through Li{sup +}...O=C which was supported by the vibration spectral analysis for interaction between Li{sup +} ion and a solvent (EC) molecule. It was analyzed that the solvation energy and Mulliken charge of Li+ ion solvated by EC molecule decrease with increase in number of EC molecule. However, electron affinity shows the opposite change. This analysis with solvation energy, electron affinity and Mulliken charge supported the stabilization of 4-coordinated solvation shell among [Li{sup +}(EC){sub n}]{sub n=1-5} complexes.

  8. Removal of nitrate ions from water by activated carbons (ACs)—Influence of surface chemistry of ACs and coexisting chloride and sulfate ions

    Science.gov (United States)

    Ota, Kazunari; Amano, Yoshimasa; Aikawa, Masami; Machida, Motoi

    2013-07-01

    Adsorptive removal of nitrate ions in aqueous solution using activated carbons (ACs) was examined. After ash was removed from Filtrasorb 400 AC, oxidation and outgassing and several heat treatments were carried out to modify the textural and surface properties of ACs. AC oxidized with 8 M nitric acid followed by outgassing at 900 °C (Ox-9OG) exhibited the greatest Langmuir adsorption capacity and affinity for nitrate removal among the total 7 ACs examined. Influence of coexisting chloride and sulfate ions was investigated as well to inspect the nitrate adsorption sites. The highest amount of sites which adsorbed nitrate ions exclusively could be observed for Ox-9OG adsorbent even though as great as 250 times greater number of chloride or sulfate ions over nitrate ions were present in the same aqueous system. Some basic oxygen species on carbon were estimated to work as selective adsorption sites for nitrate ions.

  9. Bringing the heavy: carbon ion therapy in the radiobiological and clinical context

    International Nuclear Information System (INIS)

    Radiotherapy for the treatment of cancer is undergoing an evolution, shifting to the use of heavier ion species. For a plethora of malignancies, current radiotherapy using photons or protons yields marginal benefits in local control and survival. One hypothesis is that these malignancies have acquired, or are inherently radioresistant to low LET radiation. In the last decade, carbon ion radiotherapy facilities have slowly been constructed in Europe and Asia, demonstrating favorable results for many of the malignancies that do poorly with conventional radiotherapy. However, from a radiobiological perspective, much of how this modality works in overcoming radioresistance, and extending local control and survival are not yet fully understood. In this review, we will explain from a radiobiological perspective how carbon ion radiotherapy can overcome the classical and recently postulated contributors of radioresistance (α/β ratio, hypoxia, cell proliferation, the tumor microenvironment and metabolism, and cancer stem cells). Furthermore, we will make recommendations on the important factors to consider, such as anatomical location, in the future design and implementation of clinical trials. With the existing data available we believe that the expansion of carbon ion facilities into the United States is warranted

  10. 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.

  11. 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.

  12. 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.

  13. Influence of electrolyte ion-solvent interactions on the performances of supercapacitors porous carbon electrodes

    Science.gov (United States)

    Decaux, C.; Matei Ghimbeu, C.; Dahbi, M.; Anouti, M.; Lemordant, D.; Béguin, F.; Vix-Guterl, C.; Raymundo-Piñero, E.

    2014-10-01

    The development of advanced and safe electrochemical supercapacitors or hybrid supercapacitors combining a battery electrode material such as graphite and a porous carbon electrode implies the use of new electrolytes containing a tetra-alkylammonium or lithium salt dissolved preferentially in a safe and environmentally friendly solvent such as alkylcarbonates. In those systems, the carbon porosity of the activated carbon electrode controls the electrochemical behavior of the whole device. In this work, it is demonstrated that electrolytes containing highly polarizing ions such as Li+ dissolved in polar solvents such as alkylcarbonates do not completely loss their solvation shell at the opposite of what is observed for poorly solvated cations like TEABF4. As a consequence, the optimal carbon pore size for obtaining the largest energy density, while keeping a high power density, is wider when strongly solvated cations, like Li+ are used than for conventional organic electrolytes using acetonitrile as solvent and TEA+ as salt cations. TEA+ cations are easily desolvated and hence are able to penetrate in small pores matching the dimensions of bare ions. The dissimilarity of behavior of alkylcarbonates and acetonitrile based electrolytes highlights the importance of ion-solvent interactions when searching the optimal porous texture for the electrode material.

  14. 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

  15. Carbon cloth supported vanadium pentaoxide nanoflake arrays as high-performance cathodes for lithium ion batteries

    International Nuclear Information System (INIS)

    Highlights: • Construct a carbon cloth supported V2O5 nanoflake arrays. • V2O5 nanoflake arrays show high Li-storage properties. • Nanoflake arrays structure is favorable for fast ion and electron transfer - Abstract: Carbon cloth supported vanadium pentoxide (V2O5) nanoflake arrays are synthesized by a facile solvothermal deposition method. The V2O5 nanoflakes grow quasi-vertically to the carbon cloth and show a star-fruit like hierarchical structure composed of 3 − 4 secondary flakes with a thickness of ∼20 nm. When applied as cathode material for lithium ion batteries, the V2O5 nanoflake arrays exhibit a high capacity of 292 mAh g−1 at 0.5 C, and 94% capacity (275 mAh g−1) retained after 100 cycles. In addition, the V2O5 nanoflakes present an impressive high-rate capability with 62% capacity (181 mAh g−1) retention when the rate changes from 0.5 C to 10 C. The noticeable electrochemical performances are mainly due to the carbon cloth supported thin nanoflake array structure, which provides fast ion/electron transfer, sufficient contact between active materials and electrolyte, and alleviates the structure degradation caused by volume expansion during the cycling process

  16. Dynamic polarization effects in ion channeling through single-wall carbon nanotubes

    Science.gov (United States)

    Zhou, Da-Peng; Wang, You-Nian; Wei, Li; Mišković, Z. L.

    2005-08-01

    Ion channeling through a single-wall carbon nanotube is simulated by solving Newton’s equations for ion motion at intermediate energies, under the action of both the surface-atom repulsive forces and the polarization forces due to the dynamic perturbation of the nanotube electrons. The atomic repulsion is described by a continuum potential based on the Thomas-Fermi-Moliere model, whereas the dynamic polarization of the nanotube electrons is described by a two-dimensional hydrodynamic model, giving rise to the transverse dynamic image force and the longitudinal stopping force. In the absence of centrifugal forces, a balance between the image force and the atomic repulsion is found to give rise to ion trajectories which oscillate over peripheral radial regions in the nanotube, provided the ion impact position is not too close to the nanotube wall, the impact angle is sufficiently small, and the incident speed is not too high. Otherwise, the ion is found to oscillate between the nanotube walls, passing over a local maximum of the potential in the center of the nanotube, which results from the image interaction. The full statistical analysis of 103 ion trajectories has been made to further demonstrate the actual effect of dynamic polarization on the ion channeling.

  17. 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

  18. Effects of evolving surface morphology on yield during focused ion beam milling of carbon

    International Nuclear Information System (INIS)

    We investigate evolving surface morphology during focused ion beam bombardment of C and determine its effects on sputter yield over a large range of ion dose (1017-1019 ions/cm2) and incidence angles (Θ = 0-80o). Carbon bombarded by 20 keV Ga+ either retains a smooth sputtered surface or develops one of two rough surface morphologies (sinusoidal ripples or steps/terraces) depending on the angle of ion incidence. For conditions that lead to smooth sputter-eroded surfaces there is no change in yield with ion dose after erosion of the solid commences. However, for all conditions that lead to surface roughening we observe coarsening of morphology with increased ion dose and a concomitant decrease in yield. A decrease in yield occurs as surface ripples increase wavelength and, for large Θ, as step/terrace morphologies evolve. The yield also decreases with dose as rippled surfaces transition to have steps and terraces at Θ = 75o. Similar trends of decreasing yield are found for H2O-assisted focused ion beam milling. The effects of changing surface morphology on yield are explained by the varying incidence angles exposed to the high-energy beam.

  19. 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.

  20. 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

  1. Formation and growth mechanisms of ion-induced iron-carbon nanocomposites at room temperature

    International Nuclear Information System (INIS)

    The irradiation of graphite surfaces with a simultaneous Fe supply have resulted into the development of various types of carbon nanocomposites. Their morphologies - diameter, density, length and apex angle strongly depend on the ratios of Fe deposition rate (DFe) to ion sputtering rate (Sion). By optimizing the ratio of DFe/Sion (2.40%), the denser and well-aligned Fe-carbon nanocomposite fibers (Fe-CNFs) could be obtained, whose average length and diameter were 0.95 μm and 17 nm, respectively. As confirmed by energy-dispersive X-ray analysis, the Fe-CNFs with amorphous-like or fine-polycrystalline phase were surely composed of carbon and Fe. Two types of growth models have been employed to explain the formation of metal-carbon nanocomposites.

  2. 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.

  3. Neuron attachment properties of carbon negative-ion implanted bioabsorbable polymer of poly-lactic acid

    International Nuclear Information System (INIS)

    Modification of a bioabsorbable polymer of poly-lactic acid (PLA) by negative carbon ion implantation was investigated with resect to radiation effects on surface physical properties and nerve-cell attachment properties. Carbon negative ions were implanted to PLA at energy of 5-30 keV with a dose of 1014-1016 ions/cm2. Most C-implanted PLA samples showed contact angles near 80 deg. and almost same as that of unimplanted PLA, although a few samples at 5 keV and less 3x1014 ions/cm2 had contact angles larger than 90 deg. The attachment properties of nerve cells of PC-12h (rat adrenal phechromocytoma) in vitro were studied. PC-12h cells attached on the unimplanted region in C-implanted PLA samples at 5 and 10 keV. On the contrary, the nerve cells attached on only implanted region for the C-implanted PLA sample at 30 keV and 1x1015 ions/cm2

  4. Interaction vertex imaging (IVI) for carbon ion therapy monitoring: a feasibility study

    International Nuclear Information System (INIS)

    Proton imaging can be seen as a powerful technique for online monitoring of ion range during carbon ion therapy irradiations. Indeed, a large number of secondary protons are created during nuclear reactions, and many of these protons are likely to escape from the patient even for deep-seated tumors, carrying accurate information on the reaction vertex position. Two detection techniques have been considered: (i) double-proton detection by means of two forward-located trackers and (ii) single-proton detection in coincidence with the incoming carbon ion detected by means of a beam hodoscope. Geant4 simulations, validated by proton yield measurements performed at GANIL and GSI, show that ion-range monitoring is accessible on a pencil-beam basis with the single-proton imaging technique. Millimetric precision on the Bragg peak position is expected in the ideal case of homogeneous targets. The uncertainties in more realistic conditions should be investigated, in particular the influence of tissue heterogeneity in the very last part of the ion path (about 20 mm). (paper)

  5. Dual-ion-beam deposition of carbon films with diamond-like properties

    Science.gov (United States)

    Mirtich, M. J.; Swec, D. M.; Angus, J. C.

    1985-01-01

    A single and dual ion beam system was used to generate amorphous carbon films with diamond like properties. A methane/argon mixture at a molar ratio of 0.28 was ionized in the low pressure discharge chamber of a 30-cm-diameter ion source. A second ion source, 8 cm in diameter was used to direct a beam of 600 eV Argon ions on the substrates (fused silica or silicon) while the deposition from the 30-cm ion source was taking place. Nuclear reaction and combustion analysis indicate H/C ratios for the films to be 1.00. This high value of H/C, it is felt, allowed the films to have good transmittance. The films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Although the measured density of the films was approximately 1.8 gm/cu cm, a value lower than diamond, the films exhibited other properties that were relatively close to diamond. These films were compared with diamond like films generated by sputtering a graphite target.

  6. Tetrapropylammonium ion influence on the synthesis of Pt Ru/carbon hybrids by hydrothermal carbonization

    International Nuclear Information System (INIS)

    PtRu/Carbon hybrid materials were prepared by hydrothermal carbonization using starch as carbon source and reducing agent and H2PtCl6.6H2O e RuCl3.xH2O as metals source and catalyst of the carbonization process. The materials were prepared in the following conditions: without pH adjustment, in the absence and in the presence of tetrapropylammonium chloride (TPACl), and adjusting the pH using potassium hydroxide (KOH) or tetrapropylammonium hydroxide (TPAOH). The obtained materials were treated under argon atmosphere at 900 deg C and characterized by SEM/EDX, BET isotherm, XRD and TEM. The electro-oxidation of methanol was studied by chronoamperometry. The material prepared using TPAOH showed the best performance for methanol electro-oxidation. (author)

  7. Matrix elimination ion chromatography for determination of trace levels of anions in high purity lithium carbonate

    International Nuclear Information System (INIS)

    Lithium carbonate is used as a precursor in the synthesis of lithium-based ceramic, Li2TiO3, which is being considered as a promising solid breeder material in the tritium breeding blanket of thermonuclear fusion reactors . The presence of unwanted impurities in the precursor material can alter the ceramic properties of lithium titanate. Therefore a simple, rapid and accurate method for the determination of anionic impurities in high purity lithium carbonate has been developed. The quantitative determination of various anionic impurities (fluoride, chloride and sulphate) simultaneously was carried out by anion exchange chromatography with suppressed conductometric detection. The large concentration of carbonate anion in the solution poses a challenge in the determination of other anions present at trace level. Therefore the matrix elimination was accomplished by adopting a sample pretreatment for the removal of large excess of carbonate from the sample matrix. Onguard H-cartridges were found most suitable for this purpose. The H-guard cartridge has a packing of high capacity strong acid cation exchange resin in the H form. During the pretreatment procedure, the lithium ion in the sample exchange with H+ of the resin while the carbonate is converted to carbonic acid with the help of H+ ions. The Onguard H-cartridges could be successfully used to remove the interfering carbonate quantitatively from the salt solution provided that the concentration of carbonate is well below the total capacity of the packing material of the cartridges. The developed method was validated for its accuracy and precision. The limit of detection for various anions was in the range 0.02-0.4 μg g-1 and the relative standard deviation was 3-5 % for the overall method

  8. 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

  9. Adsorption of Ferricyanide Ion onActivated Carbon and γ-Alumina

    OpenAIRE

    J. Ketcha Mbadcam; G. F. Tchatat Wouaha; V. Hambate Gomdje

    2010-01-01

    Iron-cyanide complexes are present in soil and ground water due to anthropogenic inputs. We compared the adsorption of ferricyanide ion, on two commercial activated carbons (COM3 and COM4) and γ-alumina (A1G) in aqueous solution. Isotherm parameters obtained from batch experiments of iron-cyanide complex adsorption on these adsorbents were carried-out. The mass of the adsorbents were varied at 40 mg, 60 mg and 100 mg and the inorganic ion initial concentrations, Co also varied between 3.04×10...

  10. 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.

  11. Equilibrium thickness of carbon target interacting with nitrogen and neon ion beams

    Science.gov (United States)

    Belkova, Yu. A.; Novikov, N. V.; Teplova, Ya. A.

    2016-04-01

    The method for calculation of the target thickness which is required for the formation of equilibrium charge distribution of ions is proposed. The description of nonequilibrium processes is based on empirical estimations of charge-exchange cross sections, taking the density effect for solids into account. The variation of the average charge and the width of the nonequilibrium charge distribution as a function of the target thickness is analyzed. The results of calculations for nitrogen and neon ions in carbon are compared with experimental data.

  12. 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.

  13. L-shell ionization in high-z targets by carbon and silicon ions

    International Nuclear Information System (INIS)

    L-shell ionization in Ho, Er, Tm, Ta, W, Tl, Pb and Bi by 20 Mev carbon ions and 37.5 Mev silicon ions has been investigated. The observed L/sub //alpha/sub L//gamma/ x-ray intensity ratios are compared with the estimates based on PWBA and BEA calculations. The energy shifts in the L/sub //alpha/, L/sub //gamma/sub //1 and L/sub //gamma/sub //4 x-rays are attributed to the presence of M shell spectator vacancies. 7 refs

  14. 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

  15. Hard Carbon Wrapped in Graphene Networks as Lithium Ion Battery Anode

    International Nuclear Information System (INIS)

    Hard carbon enveloped with graphene networks was fabricated by a facile and scalable method. In the constructed architecture, hard carbon offers large lithium storage and flexible graphene layers can provide a highly conductive matrix for enabling good contact between particles and facilitate the diffusion and transport of electrons and ions. As a consequence, the hybrid anode exhibits enhanced reversible capacity (500 mAh g−1 at current density of 20 mA g−1), rate capability (400 mAh g−1 at 0.2 C, 290 mAh g−1 at 1 C, 250 mAh g−1 at 2 C, and 200 mAh g−1 at 5 C, 1C = 400 mA g−1) and cycle performance. We believe that the outstanding synergetic effect between the graphene networks and the hard carbon structures induces the superior lithium storage performance of the overall electrode by maximally utilizing the electrochemically active graphene and hard carbon particles. As far as we know, the hard carbon/graphene hybrids were firstly fabricated as anode in lithium-ion batteries

  16. 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

    2016-04-14

    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. PMID:27075098

  17. Influence of the incident angle of energetic carbon ions on the properties of tetrahedral amorphous carbon (ta-C) films

    Science.gov (United States)

    Liu, Dongping; Benstetter, Günther; Lodermeier, Edgar; Vancea, Johann

    2003-09-01

    Tetrahedral amorphous carbon (ta-C) films have been grown on Ar+-beam-cleaned silicon substrates by changing the incident angle of energetic carbon ions produced in the plasma of pulsed cathodic vacuum arc discharge. Their surface roughness, deposition rate, composition, and mechanical and frictional properties as a function of the incident angle of energetic carbon ions were reported. The substrate holder can be rotated, and so an angle of deposition was defined as the angle of ion flux with respect to the substrate surface. While the deposition angle is varied from 20° to 59°, the root-mean-square (rms) roughness decreases from 0.5 to 0.1 nm, then it turns to increase at a slow rate when the deposition angle is over 77°. The variation correlates well with the one of hardness with the deposition angle and the films with lower rms roughness exhibit the higher hardness. The soft graphite-like surface layers existing at the surfaces of these films were revealed by atomic force microscopy-based nanowear tests and their thickness increases from 0.35 to 2.9 nm with the deposition angle decreasing from 90° to 30°. The soft surface layer thickness can have a great effect on the sp3 contents measured by x-ray photoelectron spectra. Nanoscale friction coefficient measurements were performed from lateral force microscopy by using a V-shaped Si3N4 cantilever. The low friction coefficients (0.076-0.093) of ta-C films can be attributed to their graphite-like surface structure. The implications of these results on the mechanisms proposed for the film formation were discussed.

  18. 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...

  19. Investigations on the quality of treatment plans for carbon ion radiotherapy. Beam delivery systems and radiobiological models

    Energy Technology Data Exchange (ETDEWEB)

    Gillmann, Clarissa

    2014-07-01

    In a worldwide effort in research and development, radiation therapy with carbon ions has evolved to a technologically challenging but clinically very promising treatment option for cancer patients. To further improve patient benefit, optimal use of the physical and biological characteristics of carbon ions as well as of the available technologies should be made. The present thesis investigates the impact of different beam delivery systems and radiobiological models on the quality of treatment plans in carbon ion radiotherapy. The results of the study may provide pointers as to the role and the possible future implementation of the different techniques and radiobiological models in existing and upcoming particle therapy centers.

  20. 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...

  1. 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.

  2. 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

  3. Transformation from hollow carbon octahedra to compressed octahedra and their use in lithium-ion batteries

    International Nuclear Information System (INIS)

    Graphical abstract: Schematic illustration of the transformation process from hollow carbon octahedra into deflated balloon-like compressed hollow carbon octahedra ▪. Highlights: ► We demonstrate the in situ template synthesis of hollow carbon octahedra. ► The shell thickness of hollow carbon octahedra is only 2.5 nm. ► Morphology transformation could be realized by extending of reaction time. ► The hollow structures show reversible capacity as 353 mAh g−1 after 100 cycles. -- Abstract: Hollow carbon octahedra with an average size of 300 nm and a shell thickness of 2.5 nm were prepared by a reaction starting from ferrocene and Mg(CH3COO)2·4H2O at 700 °C for 10 h. They became compressed and turned into deflated balloon-like octahedra when the reaction time was increased to 16 h. It was proposed that the gas pressure generated during the reaction process induced the transformation from broken carbon hollow octahedra into deflated balloon-like compressed octahedra. X-ray powder diffraction and Raman spectroscopy indicate that the as-obtained carbon products possess a graphitic structure and high-resolution transmission electron microscopy images indicate that they have low crystallinity. Their application as an electrode shows reversible capacity of 353 mAh g−1 after 100 cycles in the charge/discharge experiments of secondary lithium ion batteries.

  4. 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.

  5. Carbon ion and high intensity acceleration test of TIT heavy ion RFQ linac

    International Nuclear Information System (INIS)

    The RFQ Linac at Tokyo Institute of Technology (TIT-RFQ) was constructed and acceleration test of ion beams 4He+ and 12C2+ was performed. The linac was designed to accelerate particles with charge to mass ratio(q/A) of 1-1/16 injected at 5 keV/u up to 214 keV/u. As the result of acceleration test, beam transmission was 89% for a low beam current. It is nearly design data 91% and the acceleration characteristic agrees well with a computer simulation. (author)

  6. A novel silicon/carbon nanocomposite anode for high performance lithium-ion micro-battery

    International Nuclear Information System (INIS)

    This paper reports a novel nanocomposite anode for lithium-ion battery, with high initial specific capacity (1200mAh/g) and good capacity retention (850mAh/g remaining after 30 cycles). Sufficient silicon nanoparticles (SiNPs) at anode make a significant contribution to specific capacity increase. Moreover, nano void space between SiNPs and carbon scaffold provide enough space for expansion and contraction of SiNPs during the process of lithium ion intercalation and deintercalation to ensure a long cycle life. The porous carbon scaffold is obtained from Si/SiO2-templated SU-8 photoresist. As such, this design and fabrication makes it possible to implement direct prototyping of three dimensional (3D) micro-battery on chip

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

    International Nuclear Information System (INIS)

    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)

  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. Swift heavy ion induced modifications of single walled carbon nanotube thin films

    Science.gov (United States)

    Vishalli; Raina, K. K.; Avasthi, D. K.; Srivastava, Alok; Dharamvir, Keya

    2016-04-01

    Thin films of single walled carbon nanotubes (SWCNTs) were prepared by Langmuir-Blodgett method and irradiated with swift heavy ions, carbon and nickel each of energy 60 MeV. The ion beams have different electronic energy loss (Se) values and the samples were exposed to various irradiation doses. The irradiated films were characterized using Raman and optical absorption spectroscopy. Raman spectroscopy results indicate the competing processes of defect creation and healing (annealing) of SWCNTs at lower fluences, while at higher fluences defect creation or damage dominates. In UV-Vis-NIR spectroscopy we find that there is decrease in the intensity of characteristic peaks with every increasing fluence, indicating decrease in the optically active states with irradiation.

  11. Silver(I Ions Ultrasensitive Detection at Carbon Electrodes―Analysis of Waters, Tobacco Cells and Fish Tissues

    Directory of Open Access Journals (Sweden)

    Sona Krizkova

    2009-09-01

    Full Text Available We used carbon paste electrodes and a standard potentiostat to detect silver ions. The detection limit (3 Signal/Noise ratio was estimated as 0.5 μM. A standard electrochemical instrument microanalysis of silver(I ions was suggested. As a working electrode a carbon tip (1 mL or carbon pencil was used. Limits of detection estimated by dilution of a standard were 1 (carbon tip or 10 nM (carbon pencil. Further we employed flow injection analysis coupled with carbon tip to detect silver(I ions released in various beverages and mineral waters. During first, second and third week the amount of silver(I ions releasing into water samples was under the detection limit of the technique used for their quantification. At the end of a thirteen weeks long experiment the content of silver(I ions was several times higher compared to the beginning of release detected in the third week and was on the order of tens of nanomoles. In subsequent experiments the influence of silver(I ions (0, 5 and 10 μM on a plant model system (tobacco BY-2 cells during a fourday exposition was investigated. Silver(I ions were highly toxic to the cells, which was revealed by a double staining viability assay. Moreover we investigated the effect of silver(I ions (0, 0.3, 0.6, 1.2 and 2.5 μM on guppies (Poecilia reticulata. Content of Ag(I increased with increasing time of the treatment and applied concentrations in fish tissues. It can be concluded that a carbon tip or carbon pencil coupled with a miniaturized potentiostat can be used for detection of silver(I ions in environmental samples and thus represents a small, portable, low cost and easy-to-use instrument for such purposes.

  12. 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

  13. 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

  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. 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...

  16. Carbon ion therapy for advanced sinonasal malignancies: feasibility and acute toxicity

    Directory of Open Access Journals (Sweden)

    Ellerbrock Malte

    2011-04-01

    Full Text Available Abstract Purpose To evaluate feasibility and toxicity of carbon ion therapy for treatment of sinonasal malignancies. First site of treatment failure in malignant tumours of the paranasal sinuses and nasal cavity is mostly in-field, local control hence calls for dose escalation which has so far been hampered by accompanying acute and late toxicity. Raster-scanned carbon ion therapy offers the advantage of sharp dose gradients promising increased dose application without increase of side-effects. Methods Twenty-nine patients with various sinonasal malignancies were treated from 11/2009 to 08/2010. Accompanying toxicity was evaluated according to CTCAE v.4.0. Tumor response was assessed according to RECIST. Results Seventeen patients received treatment as definitive RT, 9 for local relapse, 2 for re-irradiation. All patients had T4 tumours (median CTV1 129.5 cc, CTV2 395.8 cc, mostly originating from the maxillary sinus. Median dose was 73 GyE mostly in mixed beam technique as IMRT plus carbon ion boost. Median follow- up was 5.1 months [range: 2.4 - 10.1 months]. There were 7 cases with grade 3 toxicity (mucositis, dysphagia but no other higher grade acute reactions; 6 patients developed grade 2 conjunctivits, no case of early visual impairment. Apart from alterations of taste, all symptoms had resolved at 8 weeks post RT. Overall radiological response rate was 50% (CR and PR. Conclusion Carbon ion therapy is feasible; despite high doses, acute reactions were not increased and generally resolved within 8 weeks post radiotherapy. Treatment response is encouraging though follow-up is too short to estimate control rates or evaluate potential late effects. Controlled trials are warranted.

  17. 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...

  18. Targeting head and neck cancer stem cells to overcome resistance to photon and carbon ion radiation.

    Science.gov (United States)

    Bertrand, Gérald; Maalouf, Mira; Boivin, Antony; Battiston-Montagne, Priscillia; Beuve, Michael; Levy, Antonin; Jalade, Patrice; Fournier, Claudia; Ardail, Dominique; Magné, Nicolas; Alphonse, Gersende; Rodriguez-Lafrasse, Claire

    2014-02-01

    Although promising new radiation therapy techniques such as hadrontherapy are currently being evaluated in the treatment of head and neck malignancies, local control of head and neck squamous cell carcinoma (HNSCC) remains low. Here, we investigated the involvement of cancer stem-like cells (CSCs) in a radioresistant HNSCC cell line (SQ20B). Stem-like cells SQ20B/SidePopulation(SP)/CD44(+)/ALDH(high) were more resistant to both photon and carbon ion irradiation compared with non-CSCs. This was confirmed by a BrdU labeling experiment, which suggests that CSCs were able to proliferate and to induce tumorigenicity after irradiation. SQ20B/SP/CD44(+)/ALDH(high) were capable of an extended G2/M arrest phase in response to photon or carbon ion irradiation compared with non-CSCs. Moreover, our data strongly suggest that resistance of CSCs may result from an imbalance between exacerbated self-renewal and proliferative capacities and the decrease in apoptotic cell death triggering. In order to modulate these processes, two targeted pharmacological strategies were tested. Firstly, UCN-01, a checkpoint kinase (Chk1) inhibitor, induced the relapse of G2/M arrest and radiosensitization of SQ20B-CSCs. Secondly, all-trans retinoic acid (ATRA) resulted in an inhibition of ALDH activity, and induction of the differentiation and radiosensitization of SQ20B/SP/CD44(+)/ALDH(high) cells. The combination of ATRA and UCN-01 treatments with irradiation drastically decreased the surviving fraction at 2Gy of SQ20B-CSCs from 0.85 to 0.38 after photon irradiation, and from 0.45 to 0.21 in response to carbon ions. Taken together, our results suggest that the combination of UCN-01 and ATRA represent a promising pharmacological-targeted strategy that significantly sensitizes CSCs to photon or carbon ion radiation. PMID:23955575

  19. 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 ...

  20. 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

  1. 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...

  2. Carbon ion therapy for advanced sinonasal malignancies: feasibility and acute toxicity

    International Nuclear Information System (INIS)

    To evaluate feasibility and toxicity of carbon ion therapy for treatment of sinonasal malignancies. First site of treatment failure in malignant tumours of the paranasal sinuses and nasal cavity is mostly in-field, local control hence calls for dose escalation which has so far been hampered by accompanying acute and late toxicity. Raster-scanned carbon ion therapy offers the advantage of sharp dose gradients promising increased dose application without increase of side-effects. Twenty-nine patients with various sinonasal malignancies were treated from 11/2009 to 08/2010. Accompanying toxicity was evaluated according to CTCAE v.4.0. Tumor response was assessed according to RECIST. Seventeen patients received treatment as definitive RT, 9 for local relapse, 2 for re-irradiation. All patients had T4 tumours (median CTV1 129.5 cc, CTV2 395.8 cc), mostly originating from the maxillary sinus. Median dose was 73 GyE mostly in mixed beam technique as IMRT plus carbon ion boost. Median follow- up was 5.1 months [range: 2.4 - 10.1 months]. There were 7 cases with grade 3 toxicity (mucositis, dysphagia) but no other higher grade acute reactions; 6 patients developed grade 2 conjunctivits, no case of early visual impairment. Apart from alterations of taste, all symptoms had resolved at 8 weeks post RT. Overall radiological response rate was 50% (CR and PR). Carbon ion therapy is feasible; despite high doses, acute reactions were not increased and generally resolved within 8 weeks post radiotherapy. Treatment response is encouraging though follow-up is too short to estimate control rates or evaluate potential late effects. Controlled trials are warranted

  3. Carbon Ion Radiotherapy for Peripheral Stage I Non-Small Cell Lung Cancer

    Science.gov (United States)

    Kamada, Tadashi; Yamamoto, Naoyoshi; Baba, Masayuki

    The National Institute of Radiological Sciences in Chiba, Japan (NIRS) has the highest number of patients with lung cancer treated with carbon ion beams in the world. This report describes the techniques and clinical trials that have been undertaken at NIRS and preliminary results of a current study on single-fraction irradiation. The data are compared to recent results for the treatment of peripheral stage I lung cancer from the literature.

  4. 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...

  5. Physicochemical, mechanical and vacuum properties of carbon glass ceramics and its surface erosion under hydrogen and helium ions bombardment

    International Nuclear Information System (INIS)

    Results of investigations and review of properties of new high-temperature high-strength chemically resistant carbon- containing material-carbon glass ceramics, having fine-grained quasiisotropic structure, are presented. It is established that gas permeability of carbon glass ceramics is 104-105 times less than that of graphite. Carbon glass ceramics, properly heat treated has elevated radiation resistance in fast neutron flux. Threshold automization energy of carbon glass ceramics with Hg+ ions 2-3 times surpasses the graphite automization threshold. Carbon glass ceramics degasses well in vacuum at 660-840 deg C

  6. Tire-derived carbon composite anodes for sodium-ion batteries

    Science.gov (United States)

    Li, Yunchao; Paranthaman, M. Parans; Akato, Kokouvi; Naskar, Amit K.; Levine, Alan M.; Lee, Richard J.; Kim, Sang-Ok; Zhang, Jinshui; Dai, Sheng; Manthiram, Arumugam

    2016-06-01

    Hard-carbon materials are considered as one of the most promising anodes for the emerging sodium-ion batteries. Here, we report a low-cost, scalable waste tire-derived carbon as an anode for sodium-ion batteries (SIBs). Tire-derived carbons obtained by pyrolyzing acid-treated tire at 1100 °C, 1400 °C and 1600 °C show capacities of 179, 185 and 203 mAh g-1, respectively, after 100 cycles at a current density of 20 mA g-1 in sodium-ion batteries with good electrochemical stability. The portion of the low-voltage plateau region in the charge-discharge curves increases as the heat-treatment temperature increases. The low-voltage plateau is beneficial to enhance the energy density of the full cell. This study provides a new pathway for inexpensive, environmentally benign and value-added waste tire-derived products towards large-scale energy storage applications.

  7. 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.

  8. Ion microprobe measurement of strontium isotopes in calcium carbonate with application to salmon otoliths

    Science.gov (United States)

    Weber, P.K.; Bacon, C.R.; Hutcheon, I.D.; Ingram, B.L.; Wooden, J.L.

    2005-01-01

    The ion microprobe has the capability to generate high resolution, high precision isotopic measurements, but analysis of the isotopic composition of strontium, as measured by the 87Sr/ 86Sr ratio, has been hindered by isobaric interferences. Here we report the first high precision measurements of 87Sr/ 86Sr by ion microprobe in calcium carbonate samples with moderate Sr concentrations. We use the high mass resolving power (7000 to 9000 M.R.P.) of the SHRIMP-RG ion microprobe in combination with its high transmission to reduce the number of interfering species while maintaining sufficiently high count rates for precise isotopic measurements. The isobaric interferences are characterized by peak modeling and repeated analyses of standards. We demonstrate that by sample-standard bracketing, 87Sr/86Sr ratios can be measured in inorganic and biogenic carbonates with Sr concentrations between 400 and 1500 ppm with ???2??? external precision (2??) for a single analysis, and subpermil external precision with repeated analyses. Explicit correction for isobaric interferences (peak-stripping) is found to be less accurate and precise than sample-standard bracketing. Spatial resolution is ???25 ??m laterally and 2 ??m deep for a single analysis, consuming on the order of 2 ng of material. The method is tested on otoliths from salmon to demonstrate its accuracy and utility. In these growth-banded aragonitic structures, one-week temporal resolution can be achieved. The analytical method should be applicable to other calcium carbonate samples with similar Sr concentrations. Copyright ?? 2005 Elsevier Ltd.

  9. 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.

  10. 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

  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. 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.

  13. The effect of carbon ion irradiation on tumor cells of mitosis

    International Nuclear Information System (INIS)

    To explore how tumor cells of mitosis respond to carbon ion irradiation, HeLa cells of prometaphase were pretreated with 65 ng/ml nocodazole for 18 h before introducing 5 Gy carbon ions. At different time point following radiation and drug release, the viability and proliferation of cells were detected with MTT. Cell cycle distribution was detected with flow cytometric analysis. Cell death modality of apoptosis was determined with TdT-mediated dUTP-biotin nick end-labeling (TUNEL) assay. The obtained results show that synchronized cells could not proliferate any more from day 2 till day 7 after irradiation. A transient G1 arrest was detected but no observable G2 arrest was obtained. Apoptotic cell death increased slowly with time at the expense of live cells in every cell cycle. From above results, we can conclude that the introduction of carbon ions to mitotic cells certainly inhibited the capacity of cell viability and proliferation, disturbed cell cycle distribution and enhanced apoptotic cell death. (author)

  14. 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

  15. Current State Of Proton And Carbon-Ion Radiotherapy At The Hyogo Ion Beam Medical Center (HIBMC)

    Science.gov (United States)

    Murakami, Masao; Demizu, Yusuke; Niwa, Yasue; Fujii, Osamu; Terashima, Kazuki; Mima, Masayuki; Miyawaki, Daisuke; Sasaki, Ryohei; Hishikawa, Yoshio; Abe, Mitsuyuki

    2011-06-01

    HIBMC is the world's first facility to be able to use both proton (PRT) and carbon-ion radiotherapy (CiRT). The medically dedicated synchrotron can accelerate protons up to 230 MeV and carbon ions up to 320 MeV. From April 2001 to March 2010, the facility treated 3275 patients, with 2487 patients treated using PRT and 788 using CiRT. Particle radiotherapy was delivered to patients suffering from malignant tumors originating in the head and neck (502 patients), lungs (330), liver (539), prostate (1283), and the bone & soft tissue (130). The clinical results are as follows: (1) H & N tumors: The 2-year overall survival (OS) rates of patients with olfactory neuroblastoma, mucoepidermoid cancer, adenoid cystic cancer, adenocarcinoma, squamous cell carcinoma, and malignant melanoma was 100%, 86%, 78%, 78%, 66%, and 62%, respectively. (2) Lung cancer: For all 80 patients, the 3-year OS rate was 75% (Stage IA: 74%; Stage IB: 76%) and local control (LC) rate was 82% (IA: 87%; IB: 77%). Grade 3 pulmonary toxicity was observed in only 1 patient. These results are comparable to those obtained by surgery, and indicate proton therapy and carbon-ion therapy are safe and effective for stage I lung cancer. (3) Liver cancer: The 5-year LC rate for 429 tumor patient was 90%, and the 5-year OS rate for 364 patients was 38%. These results seem equivalent to those obtained by surgery or radio-frequency ablation. (4) Prostate cancer: In 290 patients treated by proton radiotherapy, five patients died from other disease in the median follow-up period of 62 months. Biochemical disease-free survival and OS rate at 5 years was 88.2% and 96.5%, respectively. Our proton radiotherapy showed excellent OS and biochemical disease-free survival rates with minimum late morbidities. PRT VS CiRT: From our retrospective analysis, it seems that there is no significant difference in the LC and OS rate in H&N, lung and liver cancer between PRT and CiRT.

  16. Current State Of Proton And Carbon-Ion Radiotherapy At The Hyogo Ion Beam Medical Center (HIBMC)

    International Nuclear Information System (INIS)

    HIBMC is the world's first facility to be able to use both proton (PRT) and carbon-ion radiotherapy (CiRT). The medically dedicated synchrotron can accelerate protons up to 230 MeV and carbon ions up to 320 MeV. From April 2001 to March 2010, the facility treated 3275 patients, with 2487 patients treated using PRT and 788 using CiRT. Particle radiotherapy was delivered to patients suffering from malignant tumors originating in the head and neck (502 patients), lungs (330), liver (539), prostate (1283), and the bone and soft tissue (130). The clinical results are as follows: (1) H and N tumors: The 2-year overall survival (OS) rates of patients with olfactory neuroblastoma, mucoepidermoid cancer, adenoid cystic cancer, adenocarcinoma, squamous cell carcinoma, and malignant melanoma was 100%, 86%, 78%, 78%, 66%, and 62%, respectively. (2) Lung cancer: For all 80 patients, the 3-year OS rate was 75%(Stage IA: 74%; Stage IB: 76%) and local control (LC) rate was 82%(IA: 87%; IB: 77%). Grade 3 pulmonary toxicity was observed in only 1 patient. These results are comparable to those obtained by surgery, and indicate proton therapy and carbon-ion therapy are safe and effective for stage I lung cancer. (3) Liver cancer: The 5-year LC rate for 429 tumor patient was 90%, and the 5-year OS rate for 364 patients was 38%. These results seem equivalent to those obtained by surgery or radio-frequency ablation. (4) Prostate cancer: In 290 patients treated by proton radiotherapy, five patients died from other disease in the median follow-up period of 62 months. Biochemical disease-free survival and OS rate at 5 years was 88.2% and 96.5%, respectively. Our proton radiotherapy showed excellent OS and biochemical disease-free survival rates with minimum late morbidities. PRT VS CiRT: From our retrospective analysis, it seems that there is no significant difference in the LC and OS rate in H and N, lung and liver cancer between PRT and CiRT.

  17. 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.

  18. 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.

  19. Ion field-evaporation from ionic liquids infusing carbon xerogel microtips

    Science.gov (United States)

    Perez-Martinez, C. S.; Lozano, P. C.

    2015-07-01

    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.

  20. Antimony/Graphitic Carbon Composite Anode for High-Performance Sodium-Ion Batteries.

    Science.gov (United States)

    Zhao, Xin; Vail, Sean A; Lu, Yuhao; Song, Jie; Pan, Wei; Evans, David R; Lee, Jong-Jan

    2016-06-01

    Although the room-temperature rechargeable sodium-ion battery has emerged as an attractive alternative energy storage solution for large-scale deployment, major challenges toward practical sodium-ion battery technology remain including identification and engineering of anode materials that are both technologically feasible and economical. Herein, an antimony-based anode is developed by incorporating antimony into graphitic carbon matrices using low-cost materials and scalable processes. The composite anode exhibits excellent overall performance in terms of packing density, fast charge/discharge capability and cyclability, which is enabled by the conductive and compact graphitic network. A full cell design featuring this composite anode with a hexacyanometallate cathode achieves superior power output and low polarization, which offers the potential for realizing a high-performance, cost-effective sodium-ion battery. PMID:27172376

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

    International Nuclear Information System (INIS)

    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 >104 and a field-effect mobility of 5 cm2 V−1 s−1 under elongation and demonstrate invariant performance over 1000 stretching cycles

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Embedding tin nanoparticles in micron-sized disordered carbon for lithium- and sodium-ion anodes

    International Nuclear Information System (INIS)

    Herein, a new and facile synthesis of a tin-carbon nanocomposite and its electrochemical characterization is presented. Tin nanoparticles were embedded in micron-sized carbonaceous particles, thus successfully preventing the aggregation of tin nanoparticles and buffering the occurring volume strain, which accompanies the reversible (de-)alloying process. Such active material presents specific capacities of around 440 and 390 mAh g−1 for applied specific currents of 0.1 and 0.2 A g−1, respectively, as lithium-ion anode using environmentally friendly and cost-efficient carboxymethyl cellulose as binder. Even more remarkably, at very high specific currents of 2, 5, and 10 A g−1, electrodes based on this composite still offer specific capacities of about 280, 240, and 187 mAh g−1, respectively. In addition, this tin-carbon nanocomposite appears highly promising as anode material for sodium-ion batteries, showing very stable cycling performance in a suitable potential range, and specific capacities of more than 180, 150, 130, and 90 mAh g−1 for an applied specific current of 12.2, 122, 244, and 610 mA g−1, respectively, thus highlighting the high versatility of this composite active material for both Li-ion and Na-ion battery technologies

  8. 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

  9. 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.

  10. Study on Microdosimetric Characteristics of 120MeV/u to 430MeV/u Carbon Ions

    CERN Document Server

    Pang, Chengguo; Li, Wuyuan; Yan, Weiwei; Yao, Zeen; Su, Youwu

    2015-01-01

    Microdosimetric single event spectra is a significant parameter in radiotherapy, which can be used to evaluate the biological effect of radiation fields. This paper simulated microscopic patterns of energy depositions for mixed radiation fields which are created by carbon ions with general purpose Monte Carlo code FLUKA. . Experimental measured lineal energy spectra produced by carbon ions of about 300MeV/u were chosen from literature to compared with the results from simulation one of the measurement set-up. In addition, the dose-weighted lineal energy spectra, frequency averaged lineal energy values and dose averaged lineal energy values of carbon ions from 120MeV/u to 430MeV/u of the measurement set-up were calculated, too. The results of this paper are meaningful for making treatment planning in carbon ion radiotherapy.

  11. Mechanical and tribological properties of carbon thin film with tungsten interlayer prepared by Ion beam assisted deposition

    Czech Academy of Sciences Publication Activity Database

    Vlčák, P.; Černý, F.; Tolde, Z.; Sepitka, J.; Gregora, Ivan; Daniš, S.

    2013-01-01

    Roč. 2013, FEB (2013). ISSN 2314-4874 Institutional support: RVO:68378271 Keywords : carbon coatings * ion beam deposition * XRD * nanoindentation Subject RIV: BM - Solid Matter Physics ; Magnetism http://dx.doi.org/10.1155/2013/630156

  12. 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

  13. 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.

  14. 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.

  15. Improvement of cycle performance for silicon/carbon composite used as anode for lithium ion batteries

    International Nuclear Information System (INIS)

    The silicon/carbon composite was prepared by mixing the silicon, graphite and pitch in the tetra-hydrofuran solution followed by pyrolyzing the blends after the evaporation of solvent. The electrochemical performance of the silicon/carbon anode for lithium ion batteries was improved by the treatment of composite powders with KCl aqueous solutions. Scanning electron microscope (SEM) observation and electrochemical impedance spectroscopy (EIS) results showed that the morphology stability of the composite electrodes can be kept during the electrochemical charge/discharge process. The composite electrode of silicon/carbon composite showed an initial reversible capacity of 575 mAh g-1 and still maintained a high reversible capacity of 506 mAh g-1 after 40 cycles with the capacity loss of ∼0.3% per cycle.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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.

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

    International Nuclear Information System (INIS)

    Carbon films have been synthesized by chemical vapor deposition (CVD) on AISI 304 stainless steel (304SS) sheets with various C2H2/H2 flow ratios at 810 °C. The films exhibit three different morphologies and structures: filament, sphere and transition types at different C2H2/H2 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 C2H2/H2 flow ratios. The carbon film modified 304SS sheets were used as cathode current collectors and coated with an active layer containing LiMn2O4 active materials, conducting additives and binders for lithium ion batteries. The electrochemical properties of these LiMn2O4 cells with bare and carbon film modified current collectors were investigated. Under high current operation, such as 3000 mA/g, the capacity of the LiMn2O4 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Two cases of intrapelvic recurrence after radical resection of rectal cancer, treated with carbon ion radiotherapy

    International Nuclear Information System (INIS)

    We report two cases of intrapelvic recurrence after radical resection of rectal cancer, which were successfully treated with Carbon Ion Radiotherapy (C-ion RT). The first case is of a 71-year-old man who underwent abdominoperineal resection (APR) with D2 lymphadenectomy for rectal cancer in December 2010, followed by adjuvant chemotherapy with S-1 plus oxaliplatin. The patient was diagnosed with a recurrence on the left pelvic wall in August 2012, and underwent C-ion RT (73.6 Gray equivalent) for this lesion in October 2012. Three months after this treatment, the lesion had regressed significantly, as ascertained by computed tomography (CT). He remains alive with no signs of recurrence. The second case is of a 63-year-old man who underwent APR with D3 lymphadenectomy for rectal cancer, followed by adjuvant chemotherapy with uracil-tegafur (UFT). The patient was diagnosed with a recurrence on the right pelvic wall in January 2013, and underwent C-ion RT(73.6 Gray equivalent) for this lesion in March 2013. Three months after this treatment, the lesion reduced significantly, and the patient is alive with no signs of recurrence. Although the long-term outcomes need to be assessed, C-ion RT could be a safe and effective therapy. (author)

  8. 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.

  9. 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 ...

  10. Facile Synthesis of Non-Graphitizable Polypyrrole-Derived Carbon/Carbon Nanotubes for Lithium-ion Batteries

    Science.gov (United States)

    Jin, Bo; Gao, Fan; Zhu, Yong-Fu; Lang, Xing-You; Han, Gao-Feng; Gao, Wang; Wen, Zi; Zhao, Ming; Li, Jian-Chen; Jiang, Qing

    2016-01-01

    Graphite is usually used as an anode material in the commercial lithium ion batteries (LIBs). The relatively low lithium storage capacity of 372 mAh g-1 and the confined rate capability however limit its large-scale applications in electrical vehicles and hybrid electrical vehicles. As results, exploring novel carbon-based anode materials with improved reversible capacity for high-energy-density LIBs is urgent task. Herein we present TNGC/MWCNTs by synthesizing tubular polypyrrole (T-PPy) via a self-assembly process, then carbonizing T-PPy at 900 °C under an argon atmosphere (TNGC for short) and finally mixing TNGC with multi-walled carbon nanotubes (MWCNTs). As for TNGC/MWCNTs, the discharge capacity of 561 mAh g-1 is maintained after 100 cycles at a current density of 100 mA g-1. Electrochemical results demonstrate that TNGC/MWCNTs can be considered as promising anode materials for high-energy-density LIBs.

  11. 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.

  12. Proton and carbon ion radiotherapy for primary brain tumors and tumors of the skull base

    International Nuclear Information System (INIS)

    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

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

    DEFF Research Database (Denmark)

    Pennathur, Sumita; Kristensen, Jesper; Crumrine, Andrew;

    2011-01-01

    Nanochannel ion transport is known to be governed by surface charge at low ionic concentrations. In this talk, we show that this surface charge is dominated by hydronium ions arising from dissolution of ambient atmospheric carbon dioxide. By refining the electrokinetic model of the nanochannel...

  14. 3D Hollow Sn@Carbon-Graphene Hybrid Material as Promising Anode for Lithium-Ion Batteries

    OpenAIRE

    Xiaoyu Zheng; Wei Lv; Yan-Bing He; Chen Zhang; Wei Wei; Ying Tao; Baohua Li; Quan-Hong Yang

    2014-01-01

    A 3D hollow Sn@C-graphene hybrid material (HSCG) with high capacity and excellent cyclic and rate performance is fabricated by a one-pot assembly method. Due to the fast electron and ion transfer as well as the efficient carbon buffer structure, the hybrid material is promising in high-performance lithium-ion battery.

  15. 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.

  16. Synthesis of carbon nanoparticles using one step green approach and their application as mercuric ion sensor

    International Nuclear Information System (INIS)

    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 Hg2+ 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. • Hg2+ is most effectively sensed with a detection limit of 16.5 nM

  17. Quality of Life in Men Treated With Carbon Ion Therapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Purpose: To prospectively assess patient quality of life (QOL) after carbon ion radiotherapy (C-ion RT) for prostate cancer, using established questionnaires. Methods and Material: The subjects were 150 patients who underwent C-ion RT. Of these, 25 patients with low-risk prostate cancer received C-ion RT alone, whereas the remaining 125 patients with a high-risk tumor also received androgen deprivation therapy. Quality of life was assessed using the self-administered Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire in all patients three times. In addition, University of California-Los Angeles Prostate Cancer Index (UCLA-PCI) was conducted in the low-risk patients. Results: The FACT-General (FACT-G) and FACT-P scores at 12 months after treatment averaged over all 150 patients showed no significant change compared with those before C-ion RT. In FACT-P subscales, emotional well-being increased significantly just after and 12 months after treatment. In contrast, physical well-being (PWB) and social/family well-being (S/FWB) decreased significantly at 12 months, whereas the prostate cancer subscale (PCS) decreased significantly just after treatment. Average scores for FACT-G, FACT-P, PWB, S/FWB, and PCS for the 125 patients receiving hormone therapy showed substantial detrimental changes at 12 months. In contrast, those of the 25 low-risk patients who had no hormone therapy showed no significant change. Similarly no significant change in the average of the UCLA-PCI scores in the low-risk patients was seen at 12 months. Conclusions: Average QOL parameters reported by patients with localized prostate cancer treated with C-ion RT, in the absence of hormone therapy, showed no significant decrease 12 months after C-ion RT

  18. Effect of ion irradiation induced structure changes in glass-carbon materials on the temperature dependence of ion-electron emission

    International Nuclear Information System (INIS)

    An experimental study is made into the effect of high-dose irradiation with normal incident with 30 keV molecular nitrogen ions on temperature dependences of an ion-electron emission yield γ(T) and the structure of a modified surface layer in glassy carbons. It is revealed that for glassy carbon specimens prepared within a temperature range of 1300-2500 Deg C the temperature curves γ(T) demonstrate step-by-step changes of γ at temperatures ranging from 20 to 300 Deg C that permits monitoring ion-induced structural transformations in a surface layer of the material. For the glassy carbon material with a lower temperature of preparation analogous step-by-step changes are not observed

  19. Corrosion of Carbon Steel and Corrosion-Resistant Rebars in Concrete Structures Under Chloride Ion Attack

    Science.gov (United States)

    Mohamed, Nedal; Boulfiza, Mohamed; Evitts, Richard

    2013-03-01

    Corrosion of reinforced concrete is the most challenging durability problem that threatens reinforced concrete structures, especially structures that are subject to severe environmental conditions (i.e., highway bridges, marine structures, etc.). Corrosion of reinforcing steel leads to cracking and spalling of the concrete cover and billions of dollars are spent every year on repairing such damaged structures. New types of reinforcements have been developed to avoid these high-cost repairs. Thus, it is important to study the corrosion behavior of these new types of reinforcements and compare them to the traditional carbon steel reinforcements. This study aimed at characterizing the corrosion behavior of three competing reinforcing steels; conventional carbon steel, micro-composite steel (MMFX-2) and 316LN stainless steel, through experiments in carbonated and non-carbonated concrete exposed to chloride-laden environments. Synthetic pore water solutions have been used to simulate both cases of sound and carbonated concrete under chloride ions attack. A three-electrode corrosion cell is used for determining the corrosion characteristics and rates. Multiple electrochemical techniques were applied using a Gamry PC4™ potentiostat manufactured by Gamry Instruments (Warminster, PA). DC corrosion measurements were applied on samples subjected to fixed chloride concentration in the solution.

  20. 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.

  1. 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.

  2. Rapid localization of carbon 14-labeled molecules in biological samples by ion mass microscopy

    International Nuclear Information System (INIS)

    We report here on the ability of secondary ion mass spectrometry (SIMS) to provide rapid imaging of the intracellular distribution of 14C-labeled molecules. The validity of this method, using mass discrimination of carbon 14 atoms, was assessed by imaging the distribution of two molecules of well-known metabolism, [14C]-thymidine and [14C]-uridine, incorporated by human fibroblasts in culture. As expected, 14C ion images showed the presence of [14C]-thymidine in the nucleus of dividing cells, whereas [14C]-uridine was present in the cytoplasm as well as the nucleus of all cells, with a large concentration in the nucleoli. The time required to obtain the distribution images with the SMI 300 microscope was less than 6 min, whereas microautoradiography, the classical method for mapping the tissue distribution of 14C-labeled molecules, usually requires exposure times of several months. Secondary ion mass spectrometry using in situ mass discrimination is proposed here as a very sensitive method which permits rapid imaging of the subcellular distribution of molecules labeled with carbon 14

  3. 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.

  4. Persistent cyclestability of carbon coated Zn–Sn metal oxide/carbon microspheres as highly reversible anode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Development of high-capacity anode materials equipped with strong cyclestability is a great challenge for use as practical electrode for high-performance lithium-ion rechargeable battery. In this study, we synthesized a carbon coated Zn–Sn metal nanocomposite oxide and carbon spheres (ZTO@C/CSs) via a simple glucose hydrothermal reaction and subsequent carbonization approach. The carbon coated ZTO/carbon microspheres composite maintained a reversible capacity of 680 mAh g−1 after 345 cycles at a current density of 100 mA g−1, and furthermore the cell based on the composite exhibited an excellent rate capability of 470 mAh g−1 even when the cell was cycled at 2000 mA g–1. The thick carbon layer formed on the ZTO nanoparticles and carbon spheres effectively buffered the volumetric change of the particles, which thus prolonged the cycling performance of the electrodes

  5. An ancient pathway combining carbon dioxide fixation with the generation and utilization of a sodium ion gradient for ATP synthesis

    OpenAIRE

    Poehlein, Anja; Schmidt, Silke; Kaster, Anne-Kristin; Goenrich, Meike; Vollmers, John; Thürmer, Andrea; Bertsch, Johannes; Schuchmann, Kai; Voigt, Birgit; Hecker, Michael; Daniel, Rolf; Thauer, Rudolf K.; Gottschalk, Gerhard; Müller, Volker

    2012-01-01

    Synthesis of acetate from carbon dioxide and molecular hydrogen is considered to be the first carbon assimilation pathway on earth. It combines carbon dioxide fixation into acetyl-CoA with the production of ATP via an energized cell membrane. How the pathway is coupled with the net synthesis of ATP has been an enigma. The anaerobic, acetogenic bacterium Acetobacterium woodii uses an ancient version of this pathway without cytochromes and quinones. It generates a sodium ion potenti...

  6. 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

  7. 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)

  8. 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...

  9. Carbon/SnO2/carbon core/shell/shell hybrid nanofibers: tailored nanostructure for the anode of lithium ion batteries with high reversibility and rate capacity

    Science.gov (United States)

    Kong, Junhua; Liu, Zhaolin; Yang, Zhengchun; Tan, Hui Ru; Xiong, Shanxin; Wong, Siew Yee; Li, Xu; Lu, Xuehong

    2012-01-01

    A carbon/SnO2/carbon core/shell/shell hybrid nanofibrous mat was successfully prepared via single-spinneret electrospinning followed by carbonization and hydrothermal treatment. The morphology and structure of carbon/SnO2/carbon hybrid nanofibers were characterized by field-emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, wide-angle X-ray diffraction and X-ray photoelectron spectroscopy, and their electrochemical properties were studied as an anode in lithium ion batteries (LIBs). It is shown that the designed hybrid nanofibrous mat exhibits excellent electrochemical properties, including high reversible capacity with high columbic efficiency and impressive rate capacity. The greatly enhanced electrochemical performance is mainly due to the morphological stability and reduced diffusion resistance, which are induced by both the carbon core and deposited carbon skin. Furthermore, the embedded and de-aggregated SnO2 nanoparticles in the carbon phase, which are less than 10 nm in size, provide large numbers of reaction sites for lithium ions and ensure complete alloying with them.A carbon/SnO2/carbon core/shell/shell hybrid nanofibrous mat was successfully prepared via single-spinneret electrospinning followed by carbonization and hydrothermal treatment. The morphology and structure of carbon/SnO2/carbon hybrid nanofibers were characterized by field-emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, wide-angle X-ray diffraction and X-ray photoelectron spectroscopy, and their electrochemical properties were studied as an anode in lithium ion batteries (LIBs). It is shown that the designed hybrid nanofibrous mat exhibits excellent electrochemical properties, including high reversible capacity with high columbic efficiency and impressive rate capacity. The greatly enhanced electrochemical performance is mainly due to the morphological stability and reduced diffusion

  10. 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.

  11. 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...

  12. Sorption of lead, mercury and cadmium ions in multi-component system using carbon aerogel as adsorbent

    International Nuclear Information System (INIS)

    In the present study, adsorption of three metal ions Pb(II), Hg(II) and Cd(II) on carbon aerogel a new form of activated carbon has been investigated in mono- and multi-component (binary and tertiary) system. Batch experiments were also carried out for mono- and multi-component systems with varying metal ion concentration (mg/l) to investigate the competitive adsorption characteristics. Many adsorbents have been studied for their adsorption properties pertaining to mono-component solutions of metal ions. However, to treat wastewater with new materials, their performance needs to be ascertained in multi-component system. The scanning electron micrographs (SEM) and EDAX spectrum of carbon aerogel surfaces before and after the adsorbent was equilibrated with the metal ion solution clearly establishes the presence of the metal ions and some surface modifications can be observed on the carbon aerogel particles adsorption with (i) surface chemistry of the pellets on the surface of carbon aerogel and (ii) inside layers of the carbon aerogel. Applicability of the isotherm models namely Freundlich and Langmuir to predict the equilibrium uptake of Pb(II), Hg(II) and Cd(II) in mono-component, binary and tertiary system has also been tested. Langmuir and Freundlich models are found to generally represent the experimental though but not consistently

  13. 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)-

  14. Tailored Recovery of Carbons from Waste Tires for Enhanced Performance as Anodes in Lithium-ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit K [ORNL; Bi, [ORNL; Saha, Dipendu [ORNL; Chi, Miaofang [ORNL; Bridges, Craig A [ORNL; Paranthaman, Mariappan Parans [ORNL

    2014-01-01

    Morphologically tailored pyrolysis-recovered carbon black is utilized in lithium-ion batteries as a potential solution for adding value to waste tire-rubber-derived materials. Micronized tire rubber was digested in a hot oleum bath to yield a sulfonated rubber slurry that was then filtered, washed, and compressed into a solid cake. Carbon was recovered from the modified rubber cake by pyrolysis in a nitrogen atmosphere. The chemical pretreatment of rubber produced a carbon monolith with higher yield than that from the control (a fluffy tire-rubber-derived carbon black). The carbon monolith showed a very small volume fraction of pores of widths 3 4 nm, reduced specific surface area, and an ordered assembly of graphitic domains. Electrochemical studies on the recovered-carbon-based anode revealed an improved Li-ion battery performance with higher reversible capacity than that of commercial carbon materials. Anodes made with a sulfonated tire-rubber-derived carbon and a control tire-rubber-derived carbon, respectively, exhibited an initial coulombic efficiency of 80% and 45%, respectively. The reversible capacity of the cell with the sulfonated carbon as anode was 400 mAh/g after 100 cycles, with nearly 100% coulombic efficiency. Our success in producing higher performance carbon material from waste tire rubber for potential use in energy storage applications adds a new avenue to tire rubber recycling.

  15. Nuclear-interaction correction of integrated depth dose in carbon-ion radiotherapy treatment planning

    International Nuclear Information System (INIS)

    In treatment planning of charged-particle therapy, tissue heterogeneity is conventionally modeled as water with various densities, i.e. stopping effective densities ρS, and the integrated depth dose measured in water (IDD) is applied accordingly for the patient dose calculation. Since the chemical composition of body tissues is different from that of water, this approximation causes dose calculation errors, especially due to difference in nuclear interactions. Here, we propose and validate an IDD correction method for these errors in patient dose calculations. For accurate handling of nuclear interactions, ρS of the patient is converted to nuclear effective density ρN, defined as the ratio of the probability of nuclear interactions in the tissue to that in water using a recently formulated semi-empirical relationship between the two. The attenuation correction factor ϕwp, defined as the ratio of the attenuation of primary carbon ions in a patient to that in water, is calculated from a linear integration of ρN along the beam path. In our treatment planning system, a carbon-ion beam is modeled to be composed of three components according to their transverse beam sizes: primary carbon ions, heavier fragments, and lighter fragments. We corrected the dose contribution from primary carbon ions to IDD as proportional to ϕwp, and corrected that from lighter fragments as inversely proportional to ϕwp. We tested the correction method for some non-water materials, e.g. milk, lard, ethanol and water solution of potassium phosphate (K2HPO4), with un-scanned and scanned carbon-ion beams. In un-scanned beams, the difference in IDD between a beam penetrating a 150 mm-thick layer of lard and a beam penetrating water of the corresponding thickness amounted to −4%, while it was +6% for a 150 mm-thick layer of 40% K2HPO4. The observed differences were accurately predicted by the correction method. The corrected IDDs agreed with the measurements within ±1% for all

  16. 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.)

  17. 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

  18. Phase i study evaluating the treatment of patients with hepatocellular carcinoma (HCC) with carbon ion radiotherapy: The PROMETHEUS-01 trial

    International Nuclear Information System (INIS)

    Treatment options for patients with advanced hepatocellular carcinoma (HCC) are often limited. In most cases, they are not amenable to local therapies including surgery or radiofrequency ablation. The multi-kinase inhibitor sorafenib has shown to increase overall survival in this patient group for about 3 months. Radiation therapy is a treatment alternative, however, high local doses are required for long-term local control. However, due to the relatively low radiation tolerance of liver normal tissue, even using stereotactic techniques, delivery of sufficient doses for successful local tumor control has not be achieved to date. Carbon ions offer physical and biological characteristics. Due to their inverted dose profile and the high local dose deposition within the Bragg peak precise dose application and sparing of normal tissue is possible. Moreover, in comparison to photons, carbon ions offer an increased relative biological effectiveness (RBE), which can be calculated between 2 and 3 depending on the HCC cell line as well as the endpoint analyzed. Japanese Data on the evaluation of carbon ion radiation therapy showed promising results for patients with HCC. In the current Phase I-PROMETHEUS-01-Study, carbon ion radiotherapy will be evaluated for patients with advanced HCC. The study will be performed as a dose-escalation study evaluating the optimal carbon ion dose with respect to toxicity and tumor control. Primary endpoint is toxicity, secondary endpoint is progression-free survival and response. The Prometheus-01 trial ist the first trial evaluating carbon ion radiotherapy delivered by intensity-modulated rasterscanning for the treatment of HCC. Within this Phase I dose escalation study, the optimal dose of carbon ion radiotherapy will be determined.

  19. 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

  20. 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

  1. Dose profile monitoring with carbon ions by means of prompt-gamma measurements

    International Nuclear Information System (INIS)

    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.

  2. 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.

  3. Radiosensitizing effect of gold nanoparticles in carbon ion irradiation of human cervical cancer cells

    International Nuclear Information System (INIS)

    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

  4. Surface activated carbon nanospheres for fast adsorption of silver ions from aqueous solutions.

    Science.gov (United States)

    Song, Xianghua; Gunawan, Poernomo; Jiang, Rongrong; Leong, Susanna Su Jan; Wang, Kean; Xu, Rong

    2011-10-30

    We report the synthesis and activation of colloidal carbon nanospheres (CNS) for adsorption of Ag(I) ions from aqueous solutions. CNS (400-500 nm in diameter) was synthesized via simple hydrothermal treatment of glucose solution. The surface of nonporous CNS after being activated by NaOH was enriched with -OH and -COO(-) functional groups. Despite the low surface area (nanoparticles on the external surface of CNS. The kinetic data can be well fitted to the pseudo-second-order kinetics model. The adsorbed silver can be easily recovered by dilute acid solutions and the CNS can be reactivated by the same treatment with NaOH solution. The excellent adsorption performance and reusability have also been demonstrated in a continuous mode. The NaOH activated CNS reported here could represent a new type of low-cost and efficient adsorbent nanomaterials for removal of trace Ag(I) ions for drinking water production. PMID:21862215

  5. Investigation on optical absorption properties of ion irradiated single walled carbon nanotubes

    International Nuclear Information System (INIS)

    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 1×1014 ions/cm2 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

  6. Electrochemical lithium-ion storage properties of quinone molecules encapsulated in single-walled carbon nanotubes.

    Science.gov (United States)

    Ishii, Yosuke; Tashiro, Kosuke; Hosoe, Kento; Al-Zubaidi, Ayar; Kawasaki, Shinji

    2016-04-21

    We investigated the electrochemical lithium-ion storage properties of 9,10-anthraquinone (AQ) and 9,10-phenanthrenequinone (PhQ) molecules encapsulated in the inner hollow core of single-walled carbon nanotubes (SWCNTs). The structural properties of the obtained encapsulated systems were characterized by electron microscopy, synchrotron powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. We found that almost all quinone molecules encapsulated in the SWCNTs can store Li-ions reversibly. Interestingly, the undesired capacity fading, which comes from the dissolution of quinone molecules into the electrolyte, was suppressed by the encapsulation. It was also found that the overpotential of AQ was decreased by the encapsulation, probably due to the high-electric conductivity of SWCNTs. PMID:27030581

  7. 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.

  8. 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

  9. Waveguiding properties in Yb:YAG crystals implanted with protons and carbon ions.

    Science.gov (United States)

    Vázquez, G V; Ramírez, D; Márquez, H; Flores-Romero, E; Rickards, J; Trejo-Luna, R

    2012-08-01

    We report the fabrication and analysis of optical waveguides in Yb:YAG crystals using either proton or carbon ion implantation. Planar waveguides were obtained by implanting the whole surface of the crystals. Channel waveguides were defined using an electroformed mask with apertures of 10, 15, and 20 micrometers in width. The waveguiding properties of the structures were analyzed, showing good light confinement based on the transversal mode distribution and optical transmission measurements. The spectroscopic properties of the Yb ions in the YAG host are preserved after the implantation process, which demonstrates the potential of this technique for tailoring microcomponents for integrated optics applications. In particular, the Yb:YAG waveguides have the potential to operate as miniature lasers. PMID:22859050

  10. 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)

  11. 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.

  12. Clinical oxygen enhancement ratio of tumors in carbon ion radiotherapy. The influence of local oxygenation changes

    International Nuclear Information System (INIS)

    The effect of carbon ion radiotherapy on hypoxic tumors has recently been questioned because of low linear energy transfer (LET) values in the spread-out Bragg peak (SOBP). The aim of this study was to investigate the role of hypoxia and local oxygenation changes (LOCs) in fractionated carbon ion radiotherapy. Three-dimensional tumors with hypoxic subvolumes were simulated assuming interfraction LOCs. Different fractionations were applied using a clinically relevant treatment plan with a known LET distribution. The surviving fraction was calculated, taking oxygen tension, dose and LET into account, using the repairable-conditionally repairable (RCR) damage model with parameters for human salivary gland tumor cells. The clinical oxygen enhancement ratio (OER) was defined as the ratio of doses required for a tumor control probability of 50% for hypoxic and well-oxygenated tumors. The resulting OER was well above unity for all fractionations. For the hypoxic tumor, the tumor control probability was considerably higher if LOCs were assumed, rather than static oxygenation. The beneficial effect of LOCs increased with the number of fractions. However, for very low fraction doses, the improvement related to LOCs did not compensate for the increase in total dose required for tumor control. In conclusion, our results suggest that hypoxia can influence the outcome of carbon ion radiotherapy because of the non-negligible oxygen effect at the low LETs in the SOBP. However, if LOCs occur, a relatively high level of tumor control probability is achievable with a large range of fractionation schedules for tumors with hypoxic subvolumes, but both hyperfractionation and hypofractionation should be pursued with caution. (author)

  13. 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

  14. 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

  15. Sorption of Ni(II), Cu(II) and Fe(III) ions from Aqueous Solutions Using Activated Carbon

    International Nuclear Information System (INIS)

    An activated carbon was tested for its ability to remove transition metal ions from aqueous solutions. Physical, chemical and liquid-phase adsorption characterizations of the carbon were done following standard procedures. Studies on the removal of Ni(II), Cu(II) and Fe(III) ions were attempted by varying adsorbate dose, pH of the metal ion solution and time in batch mode. The equilibrium adsorption data were fitted with Freundlich and Langmuir and the isotherm constants were evaluated, equilibrium time of the different three metal ions were determined. pH was found to have a significant role to play in the adsorption. The processes were endothermic and the thermodynamic parameters were evaluated. Desorption studies indicate that ion-exchange mechanism is operating

  16. 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.

  17. Energy loss and charge state distribution of calcium ions in dense moderately coupled carbon plasma

    International Nuclear Information System (INIS)

    In this thesis the interaction of swift calcium ions (Energy: 3.5 MeV/u) with a dense and moderately coupled carbon plasma (Coupling parameter: Γ=0.1-0.5) is investigated. The plasma state is generated by heating a thin carbon foil volumetrically by thermal X-ray radiation. The thermal X-ray radiation itself is generated by the conversion of a high energy laser beam in a hohlraum cavity. Compared to earlier ion stopping experiments the electron density and the plasma coupling parameter could be increased by an order of magnitude. This work provides the first time experimental energy loss and charge state distribution data in this moderately coupled interaction regime. The thesis consists of a theoretical part where the ion beam plasma interaction is studied for a broad range of plasma parameters and an experimental part where the ion beam interaction with the hohlraum plasma target is measured. All the described experiments were carried out at the GSI Helmholtzzentrum fuer Schwerionenforschung in Darmstadt. This facility offers the unique possibility to combine a heavy ion beam from an accelerator with a high energy laser beam in one interaction chamber. An intense laser pulse (150 J of laser energy in 1 ns at λL=527 nm) is focused inside a 600 μm diameter spherical cavity and generates a hot gold plasma that emits X-rays. The absorbed and reemitted radiation establishes a spatially uniform temperature distribution in the cavity and serves as an intense, isotropic X-ray source with a quasi-thermal spectral distribution. These thermal X-rays with a radiation temperature of Tr=98±6 eV then propagate into a secondary cylindrical hohlraum (diameter: 1000 μm, length: 950 μm) where they volumetrically heat two thin carbon foils to the plasma state. The radiation temperature in the secondary hohlraum is Tr=33±5 eV. This indirect laser heating scheme has the advantage that the whole sample volume is instantaneously heated and that the plasma is inertially and

  18. 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.

  19. The comparison of calculated and experimental microdosimetric distributions for carbon ions

    Czech Academy of Sciences Publication Activity Database

    Palajová, Zdenka; Spurný, František; Davídková, Marie

    2007-01-01

    Roč. 122, 1-4 (2007), s. 491-493. ISSN 0144-8420. [Symposium on Microdosimetry /14./. Venezia, 13.11.2005-18.11.2005] R&D Projects: GA ČR GA202/04/0795; GA ČR(CZ) GD202/05/H031 Institutional research plan: CEZ:AV0Z10480505 Keywords : microdosimetry distributions * carbon ions * theoretical calculation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.528, year: 2007

  20. 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...

  1. Mutational effects of γ-rays and carbon ion beams on Arabidopsis seedlings

    OpenAIRE

    Yoshihara, Ryouhei; Nozawa, Shigeki; Hase, Yoshihiro; Narumi, Issay; Hidema, Jun; Sakamoto, Ayako N

    2013-01-01

    To assess the mutational effects of radiation on vigorously proliferating plant tissue, the mutation spectrum was analyzed with Arabidopsis seedlings using the plasmid-rescue method. Transgenic plants containing the Escherichia coli rpsL gene were irradiated with γ-rays and carbon ion beams (320-MeV 12C6+), and mutations in the rpsL gene were analyzed. Mutant frequency increased significantly following irradiation by γ-rays, but not by 320-MeV 12C6+. Mutation spectra showed that both radiatio...

  2. 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...

  3. Electrospun carbon-cobalt composite nanofiber as an anode material for lithium ion batteries

    International Nuclear Information System (INIS)

    Carbon-cobalt (C/Co) composite nanofibers with diameters from 100 to 300 nm were prepared by electrospinning and subsequent heat treatment. They were characterized by X-ray diffraction, scanning electron microscopy, galvanostatic cell cycling and impedance spectroscopy. As a lithium storage material, these fibers exhibit excellent electrochemical properties with high reversible capacity (>750 mA h g-1) and good rate capability (578 mA h g-1 at 1 C rate). These composite fibers are a promising anode material for high-power Li-ion batteries

  4. 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.)

  5. Mechanical properties of nickel ion-implanted with titanium and carbon and their relation to microstructure

    International Nuclear Information System (INIS)

    Dual ion implantation of titanium and carbon into nickel was shown to produce an amorphous layer with exceptionally high strength and hardness and substantially improved tribological properties. Indentation testing at submicrometer penetrations combined with finite-element modeling permitted quantification of the intrinsic elastic and plastic properties of the amorphous layer, which was found to have a yield strength near 5 GPa. During unlubricated sliding contact with a steel pin, the implantation treatment reduced friction, suppressed adhesion-and-fracture wear, and reduced wear depth. These tribological effects may enhance the performance and lifetime of microelectromechanical systems constructed from nickel

  6. Carbon-coated mesoporous SnO2 nanospheres as anode material for lithium ion batteries

    International Nuclear Information System (INIS)

    In this paper mesoporous SnO2 nanospheres with an average diameter of about 83 nm, composed of many tiny primary particles (∼10 nm) and holes, are synthesized on a large scale by a simple hydrothermal route. The as-prepared mesoporous SnO2 nanospheres were uniformly coated with carbon by a further hydrothermal treatment in glucose aqueous solution. As anode materials for lithium-ion batteries, the core–shell SnO2/C nanocomposites exhibit a markedly improved cycling performance.

  7. Electrochemical Performance of Electrospun carbon nanofibers as free-standing and binder-free anodes for Sodium-Ion and Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Highlights: • Electrospun carbon nanofiber webs were prepared by pyrolysis of polyacrylonitrile. • The webs as binder-free and current collector-free electrodes for SIBs and LIBs. • Different layer spacing and pore size for Li and Na lead different electrochemical behavior. • Electrochemical performances of the electrodes were high. - Abstract: A series of hard carbon nanofiber-based electrodes derived from electrospun polyacrylonitrile (PAN) nanofibers (PAN-CNFs) have been fabricated by stabilization in air at about 280 °C and then carbonization in N2 at heat treatment temperatures (HTT) between 800 and 1500 °C. The electrochemical performances of the binder-free, current collector-free carbon nanofiber-based anodes in lithium-ion batteries and sodium-ion batteries are systematically investigated and compared. We demonstrate the presence of similar alkali metal insertion mechanisms in both cases, but just the differences of the layer spacing and pore size available for lithium and sodium ion lead the discharge capacity delivered at sloping region and plateau region to vary from the kinds of alkali elements. Although the anodes in sodium-ion batteries show poorer rate capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 275 mAh g−1 and similar cycling stability due to the conductive 3-D network, weakly ordered turbostratic structure and a large interlayer spacing between graphene sheets. The feature of high capacity and stable cycling performance makes PAN-CNFs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries

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

    Science.gov (United States)

    Francis, Z.; Seif, E.; Incerti, S.; Champion, C.; Karamitros, M.; Bernal, M. A.; Ivanchenko, V. N.; Mantero, A.; Tran, H. N.; El Bitar, Z.

    2014-12-01

    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.

  9. 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.

  10. Range measurements of keV hydrogen ions in solid oxygen and carbon monoxide

    International Nuclear Information System (INIS)

    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 agrees with that previously found for solid nitrogen. (orig.)

  11. 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)

  12. Extraction of cobalt ion from textile using a complexing macromolecular surfactant in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Cobalt ion under the form of cobalt nitrate is removed from a textile lab coat using supercritical carbon dioxide extraction. The process involves a macromolecular additive of well-defined architecture, acting both as a surfactant and a complexing agent. The extraction efficiency of cobalt reaches 66% when using a poly(1,1,2,2-tetrahydroperfluoro-decyl-acrylate-co-vinyl-benzylphosphonic diacid) gradient copolymer in the presence of water at 160 bar and 40 C. The synergy of the two additives, namely the copolymer and water which are useless if used separately, is pointed out. The potential of the supercritical carbon dioxide process using complexing macromolecular surfactant lies in the ability to modulate the complexing unit as a function of the metal as well as the architecture of the surface-active agent for applications ranging for instance from nuclear decontamination to the recovery of strategic metals. (authors)

  13. 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)

  14. 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.

  15. 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)

  16. 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)

  17. 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)

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

    International Nuclear Information System (INIS)

    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 · 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 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 · 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

  19. 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

  20. Hard Carbon-coated Natural Graphite Electrodes for High-Energy and Power Lithium-Ion Capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Young-Geun; Park, Jung Woo; Park, Min-Sik; Yu, Ji-Sang; Jo, Yong Nam; Kim, Young-Jun [Advanced Batteries Research Center, Korea Electronics Technology Institute, Incheon (Korea, Republic of); Byun, Dongjin [Korea University, Seoul (Korea, Republic of)

    2015-01-15

    Hard carbon-coated natural graphite materials have been prepared and evaluated as a negative electrode for high-energy and high-power lithium-ion capacitors. The graphite surface was coated with hard carbon by using polyacrylonitrile as a precursor, which was confirmed by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. The hard carbon coating on natural graphite particles significantly affects the electrochemical characteristics of lithium-ion capacitors. The full-cell using the hard carbon-coated graphite electrode showed much higher energy and power densities than those with pristine natural graphite and hard carbon electrodes, respectively. Furthermore, the hard carbon-coated graphite electrode exhibited an enhanced cycle performance with a capacity retention of 74.6% after 10,000 cycles, higher than those of pristine natural graphite (33.3%) and the mixture of hard carbon and natural graphite (51.4%). The results clearly indicate that the hard carbon-coated graphite electrode is suitable as a negative electrode material for high-energy and highpower lithium-ion capacitors.

  1. Formation of low friction and wear-resistant carbon coatings on tool steel by 75keV, high-dose carbon ion implantation

    International Nuclear Information System (INIS)

    Hardened AISI D2 steel samples were subjected to mass-separated C+ ion bombardment at 75keV with ion doses in the range 0.5-15x1018C+cm-2. It was observed that sputtering was still limited, and the system exhibited internal growth, because most of the ions penetrated more than 0.1μm into the growing carbon film. At the lowest ion doses applied, carbon was implanted into the steel, while higher doses resulted in the implanted carbon concentration near the surface being almost 100%. For the highest doses applied, Rutherford backscattering spectrometry and surface profilometry analyses showed that layers about 0.5-1μm thick of almost pure carbon grew outward from the steel substrate. Transmission electron microscopy showed that the carbon layers were amorphous and exhibited an intermixed layer-substrate interface. The layers were hard and exhibited pronounced elastic recovery when subjected to ultralow load indentation. Low friction and excellent wear properties were measured when tested under dry conditions with a ball-on-disc tribometer. ((orig.))

  2. Fabrication of carbon microcapsules containing silicon nanoparticles-carbon nanotubes nanocomposite by sol-gel method for anode in lithium ion battery

    International Nuclear Information System (INIS)

    Carbon microcapsules containing silicon nanoparticles (Si NPs)-carbon nanotubes (CNTs) nanocomposite (Si-CNT-C) have been fabricated by a surfactant mediated sol-gel method followed by a carbonization process. Silicon nanoparticles-carbon nanotubes (Si-CNT) nanohybrids were produced by a wet-type beadsmill method. To obtain Si-CNT nanocomposites with spherical morphologies, a silica precursor (tetraethylorthosilicate, TEOS) and polymer (PMMA) mixture was employed as a structure-directing medium. Thus the Si-CNT/Silica-Polymer microspheres were prepared by an acid catalyzed sol-gel method. Then a carbon precursor such as polypyrrole (PPy) was incorporated onto the surfaces of pre-existing Si-CNT/silica-polymer to generate Si-CNT/Silica-Polymer-PPy microspheres. Subsequent thermal treatment of the precursor followed by wet etching of silica produced Si-CNT-C microcapsules. The intermediate silica/polymer must disappear during the carbonization and etching process resulting in the formation of an internal free space. The carbon precursor polymer should transform to carbon shell to encapsulate remaining Si-CNT nanocomposites. Therefore, hollow carbon microcapsules containing Si-CNT nanocomposites could be obtained (Si-CNT-C). The successful fabrication was confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). These final materials were employed for anode performance improvement in lithium ion battery. The cyclic performances of these Si-CNT-C microcapsules were measured with a lithium battery half cell tests. - Graphical Abstract: Carbon microcapsules containing silicon nanoparticles (Si NPs)-carbon nanotubes (CNTs) nanocomposite (Si-CNT-C) have been fabricated by a surfactant mediated sol-gel method. Highlights: → Polymeric microcapsules containing Si-CNT transformed to carbon microcapsules. → Accommodate volume changes of Si NPs during Li ion charge/discharge. → Sizes of microcapsules were controlled by experimental parameters.

  3. Ion induced transformation of polymer films into diamond-like carbon incorporating silver nano particles

    International Nuclear Information System (INIS)

    Silver containing diamond-like carbon (DLC) is an interesting material for medical engineering from several points of view. On the one hand DLC provides high mechanical robustness. It can be used as biocompatible and wear resistant coating for joint replacing implants. On the other hand silver has antimicrobial properties, which could reduce post-operative inflammations. However conventional production of Ag-DLC by co-deposition of silver and carbon in a plasma process is problematic since it does not allow for a separate control of nano particle morphology and matrix properties. In this work an alternative production method has been developed to circumvent this problem. In metall-DLC-production by ion implantation into a nano composite, silver nano particles are initially formed in solution and then incorporated within a polymer matrix. Finally the polymer is transformed into DLC by ion implantation. The aspects and single steps of this method were investigated with regard to the resulting material's properties. The goal was to design an economically relevant deposition method. Based on experimental results a model of the transformation process has been established, which has also been implemented in a computer simulation. Finally the antibacterial properties of the material have been checked in a biomedical test. Here a bacterial killing rate of 90% could be achieved. (orig.)

  4. 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...

  5. 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.

  6. 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)

  7. Association of serum reactive oxygen metabolite levels with normal tissue damages by carbon-ion radiotherapy

    International Nuclear Information System (INIS)

    Oxygen is required for respiration and the energetic processes that enable aerobic life. Free radical and reactive oxygen metabolite (ROM) formations create oxidative stress and contribute to various processes including aging, degenerative diseases and cancer. Additionally, they may have a role in the radiotherapy for various types of cancer. In this study, we aimed to investigate the degree of oxidative stress for carbon-ion radiotherapy in locally recurrent rectal cancer and pancreas cancer, and to find out whether the degree of oxidative stress shows any difference among different grade of normal tissue damages. It can be used as an index for their differential diagnosis. Sixteen patients with locally recurrent rectal cancer and 6 pancreas cancers were included in the study. The BAP levels were lower before carbon-ion treatment than after treatment. The ROM levels were significantly lower before treatment than after treatment. It might be possible to conclude that the serum BAP and ROM levels may be an index parameter for normal tissue damages. (author)

  8. 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

  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. 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

  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. 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)

  14. Rectal cancer with local re-recurrence successfully treated by carbon ion radiotherapy

    International Nuclear Information System (INIS)

    A 61 year-old male with rectal cancer underwent anterior resection with D2 lymph node dissection in August 2007. Carcinoembryonic antigen (CEA) level was 5.6 before the operation. Pathological findings were Rs, tub2>>tub1, type 3, pSE, ly1, v2, pN1 (1/23), H0, P0, M0, pStage 3A. Adjuvant chemotherapy with tegafur-uracil (UFT) 600 mg/Leucovorin (LV) 75 mg was administered for 1 year. A recurrence at a site of anastomosis developed and lower anterior resection was required in September 2010. CEA level was 5.4 before the operation. After 7 courses of capecitabine plus oxaliplatin (XELOX) treatment, the right no. 283 lymph node increased to 8 mm in October 2011 and the patient was diagnosed with a re-recurrence of the original tumor (CEA level, 4.6). Carbon ion radiotherapy (73.6 Gy/16 Fr/4 weeks) was performed between November 28 and December 22, 2011. Although the right no. 283 lymph node had shrunk by January 2012, a single node in the S3 domain of the right lung was observed and became progressively larger, indicating a lung metastasis (CEA level, 5.4). The patient received carbon ion radiotherapy (60.0 Gy/4 Fr) for the lung metastasis between July 30 and August 2, 2012. No additional recurrences have been seen through February 2014. (author)

  15. Tubular electrodeposition of chitosan-carbon nanotube implants enriched with calcium ions.

    Science.gov (United States)

    Nawrotek, Katarzyna; Tylman, Michał; Rudnicka, Karolina; Gatkowska, Justyna; Balcerzak, Jacek

    2016-07-01

    A new approach for obtaining chitosan-carbon nanotube implants enriched with calcium ions in the form of tubular hydrogels is fostered. The intended application of the hydrogels is tissue engineering, especially peripheral nervous tissue regeneration. The fabrication method, based on an electrodeposition phenomenon, shows significant advantages over current solutions as implants can now be obtained rapidly at any required dimensions. Thus, it may open a new avenue to treat patients with peripheral nerve injuries. Either single walled or multiwalled carbon nanotubes enhance the mechanical properties of the tubular hydrogels. The controlled presence of calcium ions, sourced from hydroxyapatite, is also expected to augment the regenerative response. Because in vitro cytotoxic assays on mouse cell lines (L929 fibroblasts and mHippoE-18 hippocampal cells) as well as pro-inflammatory tests on THP-1XBlue™ cells show that the manufactured implants are biocompatible, we next intend to evaluate their immune- and nervous-safety on an animal model. PMID:26913639

  16. A comparative study on micronuclei production induced by carbon ion versus 60Co γ-rays in human peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Objective: To compare the effectiveness of carbon ion versus 60Co γ-rays in producing micronuclei in human peripheral blood lymphocytes. Method: Heparinized whole blood samples were exposed to carbon ion and 60Co γ-rays, respectively. Micronuclei in binuclear lymphocytes (CB method) were scored. Relative biological effectiveness (RBE) values were calculated. Results: RBE values of carbon ion decreased with increasing dose (ranged from 1.78 to 4.19 ). The average RBE value is 2.56. Conclusion: Carbon ion has higher biological effectiveness in inducing micronuclei than 60Co γ-rays do

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

    Energy Technology Data Exchange (ETDEWEB)

    Arif, Shafaq, E-mail: sarif2005@gmail.com [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Rafique, M. Shahid [Department of Physics, University of Engineering & Technology, Lahore 54000 (Pakistan); Saleemi, Farhat; Sagheer, Riffat [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Naab, Fabian; Toader, Ovidiu [Department of Nuclear Engineering and Radiological Sciences, Michigan Ion Beam Laboratory, University of Michigan, MI 48109-2104 (United States); Mahmood, Arshad; Rashid, Rashad [National Institute of Lasers and Optronics (NILOP), P.O. Nilore, Islamabad (Pakistan); Mahmood, Mazhar [Department of Metallurgy & Materials Engineering, Pakistan Institute of Engineering & Applied Sciences (PIEAS), Islamabad (Pakistan)

    2015-09-01

    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{sup +} ion implantation effects on PMMA at different fluences ranging from 5 × 10{sup 13} to 5 × 10{sup 15} ions/cm{sup 2}. 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 × 10{sup 14} to 5 × 10{sup 15} ions/cm{sup 2}. The existence of amorphization and sp{sup 2}-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{sup −10} (Ω-cm){sup −1} (pristine) to (0.32 ± 0.01) × 10{sup −5} (Ω-cm){sup −1} (irradiated sample)

  18. 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)

  19. 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

  20. The development of chloride ion selective polypyrrole thin film on a layer-by-layer carbon nanotube working electrode

    Science.gov (United States)

    Liu, Yang; Lynch, Jerome

    2011-04-01

    A chloride ion selective thin film sensor is proposed for measuring chloride ion concentration, which is an environmental parameter correlated to corrosion. In this work, electrochemical polymerization of Polypyrrole (PPy) doped with chloride ions was achieved on the top of a carbon nanotube (CNT) thin film as a working electrode in an electrochemical cell. The underlying CNT layer conjugated with doped PPy thin film can form a multifunctional "selfsensing" material platform for chloride ion detection in a concrete environment. The paper presents the first type of work using CNT and PPy as hybrid materials for chloride ion sensing. Electrochemical polymerization of PPy results in oxidation that yields an average of one positive charge distributed over four pyrrole units. This positive charge is compensated by negatively-charged chloride ions in the supporting electrolyte. In effect, the chloride ion-doped PPy has become molecularly imprinted with chloride ions thereby providing it with some degree of perm-selectivity for chloride ions. The detection limit of the fabricated chloride ion-doped PPy thin film can reach 10-8 M and selectivity coefficients are comparable to those in the literature. The reported work aims to lay a strong foundation for detecting chloride ion concentrations in the concrete environment.

  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. The first French randomized prospective study of the economic and medical benefit of carbon ion radiotherapy; Premiere etude francaise prospective randomisee de l'interet medical et economique de la radiotherapie par ions carbone

    Energy Technology Data Exchange (ETDEWEB)

    Pommier, P. [Centre Leon-Berard, Lyon (France); Patin, S.; Vogin, G.; Hu, Y. [GCS-etoile, Lyon (France); Buron van de Voorde, C. [Hospices civils de Lyon (France); Baron, M.H. [CHUde Besancon (France); Lievre, M. [Universite Claude-Bernard, Lyon (France); Balosso, J. [Universite Joseph-Fourier, Grenoble (France)

    2011-10-15

    Carbon ion therapy is an innovative radiotherapy modality for non-operable radio-resistant or resected cancers. Its efficiency is due to improved ballistic accuracy and biological efficiency. The authors present the first phase III study of carbon ion therapy in France. This technique concerns some sarcomas and adenoid cystic carcinomas of head and neck. The authors indicate the possible treatment procedures (doses, sessions) for the different types of cancers, and how the study is to be performed (number of patients, randomization, and multicentre approach). Short communication

  5. 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

  6. Detection of fission products in carbon dioxide by instantaneous ion collection

    International Nuclear Information System (INIS)

    This report describes a fission product detector with instantaneous electric collection, capable of analyzing carbon dioxide up to a pressure of 60 bars and at a temperature of 200 C. In contrast to delayed collection detectors, this apparatus makes it possible to collect rubidium and cesium ions as soon as they are formed; this avoids losses due to recombination. The detector has been tested with a fission product source made up of a uranium oxide sample subjected to a neutron flux. The activity of the ions collected as a function of an electric field has been measured for different parameters: pressure, temperature, CO2 gas flow rate, and the volume of the ion-formation chamber. The sensitivity of this apparatus is compared to that of other fission product detectors. For a low volume-flow rate, e.g. 100 cm3 sec-1, its sensitivity for krypton 88 is better than that of a delayed collection detector. An apparatus of this type could be used as a can rupture detector on a reactor with a large number of channels, with a low gas sampling rate per channel. The equipment will be included in the can rupture detector installations in the Fessenheim reactor. (authors)

  7. 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 ...

  8. Antimony nanoparticles anchored in three-dimensional carbon network as promising sodium-ion battery anode

    Science.gov (United States)

    Luo, Wen; Zhang, Pengfei; Wang, Xuanpeng; Li, Qidong; Dong, Yifan; Hua, Jingchen; Zhou, Liang; Mai, Liqiang

    2016-02-01

    A novel composite with antimony (Sb) nanoparticles anchored in three-dimensional carbon network (denoted as SbNPs@3D-C) is successfully synthesized via a NaCl template-assisted self-assembly strategy, followed by freeze-drying and one-step in-situ carbonization. The three-dimensional interconnected macroporous carbon framework can not only stabilize the architecture and buffer the volume expansion for Sb nanoparticles, but also provide high electrical conductivity for the whole electrode. Consequently, as a sodium-ion battery anode, the SbNPs@3D-C delivers a high reversible capacity (456 mAh g-1 at 100 mA g-1), stable cycling performance (94.3% capacity retention after 500 cycles at 100 mA g-1) as well as superior rate capability (270 mAh g-1 at 2000 mA g-1). When compared with commercial Sb particles, the SbNPs@3D-C exhibits dramatically enhanced electrochemical performance. Free from expensive template sources and complex manipulation, this work might shed some light on the synthesis of low-cost and high-performance materials for the next "beyond lithium" battery generation.

  9. 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

  10. Characterization of ion-irradiation-induced defects in multi-walled carbon nanotubes

    Science.gov (United States)

    Lehtinen, Ossi; Nikitin, Timur; Krasheninnikov, Arkady V.; Sun, Litao; Banhart, Florian; Khriachtchev, Leonid; Keinonen, Juhani

    2011-07-01

    We study the effects of Ar+, He+ and C+ ion irradiation on multi-walled carbon nanotubes at room and elevated temperatures with transmission electron microscopy (TEM) and Raman spectroscopy. Based on the TEM data, we introduce a universal damage scale for the visual analysis and characterization of irradiated nanotubes. We show for the first time that the amount of irradiation-induced damage in nanotubes is larger than the value predicted for bulk materials using the simple binary collision approximation, which may be associated with higher defect production due to electronic stopping in these nanoscale systems. The Raman spectra of the irradiated samples are in qualitative agreement with the TEM data and indicate the presence of irradiation-induced defects. However, it is difficult to obtain quantitative information on defect concentration due to non-uniform distribution of defects in the nanotube films and in part due to the presence of other carbon nanosystems in the samples, such as graphitic crystallites and carbon onions.

  11. 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.

  12. 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.

  13. 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

  14. Modification of tribomechanical properties of commercial TiN coatings by carbon ion implantation

    International Nuclear Information System (INIS)

    Physical vapour deposited commercial TiN coatings of about 2μm thickness on high speed steel substrates were implanted at room temperature with 95keV carbon ions at nominal doses between 1x1017 and 8x1017ionscm-2. An ultra-microhardness apparatus (UMIS-2000) was used to measure hardness, and a pin-on-disc machine (CSEM tribometer) with a sapphire ball was used to measure wear, friction and adhesion. Carbon implantation induced a significant improvement in ultra-microhardness, friction coefficient and wear properties. The surface microhardness increases monotonically by up to 115% until a critical dose φcrit 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 implantation. Proton elastic scattering (PES) measurements show loss of nitrogen after implantation by up to 27%. Rutherford backscattering (RBS) analysis indicated that some implanted carbon has diffused out from the implanted region towards the TiN surface. The changes in tribomechanical properties are discussed in terms of radiation damage and possible second phase formation. ((orig.))

  15. 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

  16. 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.

  17. Raster-scanned carbon ion therapy for malignant salivary gland tumors: acute toxicity and initial treatment response

    International Nuclear Information System (INIS)

    To investigate toxicity and efficacy in high-risk malignant salivary gland tumors (MSGT) of the head and neck. Local control in R2-resected adenoid cystic carcinoma was already improved with a combination of IMRT and carbon ion boost at only mild side-effects, hence this treatment was also offered to patients with MSGT and microscopic residual disease (R1) or perineural spread (Pn+). From November 2009, all patients with MSGT treated with carbon ion therapy were evaluated. Acute side effects were scored according to CTCAE v.4.03. Tumor response was assessed according to RECIST where applicable. 103 patients were treated from 11/2009 to 03/2011, median follow-up is 6 months. 60 pts received treatment following R2 resections or as definitive radiation, 43 patients received adjuvant radiation for R1 and/or Pn+. 16 patients received carbon ion treatment for re-irradiation. Median total dose was 73.2 GyE (23.9 GyE carbon ions + 49,9 Gy IMRT) for primary treatment and 44.9 GyE carbon ions for re-irradiation. All treatments were completed as planned and generally well tolerated with no > CTC°III toxicity. Rates of CTC°III toxicity (mucositis and dysphagia) were 8.7% with side-effects almost completely resolved at first follow-up. 47 patients showed good treatment responses (CR/PR) according to RECIST. Acute toxicity remains low in IMRT with carbon ion boost also in R1-resected patients and patients undergoing re-irradiation. R2-resected patients showed high rates of treatment response, though follow-up is too short to assess long-term disease control

  18. A Mechanism-Based Approach to Predict the Relative Biological Effectiveness of Protons and Carbon Ions in Radiation Therapy

    International Nuclear Information System (INIS)

    Purpose: The physical and potential biological advantages of proton and carbon ions have not been fully exploited in radiation therapy for the treatment of cancer. In this work, an approach to predict proton and carbon ion relative biological effectiveness (RBE) in a representative spread-out Bragg peak (SOBP) is derived using the repair-misrepair-fixation (RMF) model. Methods and Materials: Formulas linking dose-averaged linear-quadratic parameters to DSB induction and processing are derived from the RMF model. The Monte Carlo Damage Simulation (MCDS) software is used to quantify the effects of radiation quality on the induction of DNA double-strand breaks (DSB). Trends in parameters α and β for clinically relevant proton and carbon ion kinetic energies are determined. Results: Proton and carbon ion RBE are shown to increase as particle energy, dose, and tissue α/β ratios decrease. Entrance RBE is ∼1.0 and ∼1.3 for protons and carbon ions, respectively. For doses in the range of 0.5 to 10 Gy, proton RBE ranges from 1.02 (proximal edge) to 1.4 (distal edge). Over the same dose range, the RBE for carbon ions ranges from 1.5 on the proximal edge to 6.7 on the distal edge. Conclusions: The proposed approach is advantageous because the RBE for clinically relevant particle distributions is guided by well-established physical and biological (track structure) considerations. The use of an independently tested Monte Carlo model to predict the effects of radiation quality on DSB induction also minimizes the number of ad hoc biological parameters that must be determined to predict RBE. Large variations in predicted RBE across an SOBP may produce undesirable biological hot and cold spots. These results highlight the potential for the optimization of physical dose for a uniform biological effect.

  19. 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.

  20. 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