WorldWideScience

Sample records for carbon 11 beams

  1. Carbon Fiber Damage in Accelerator Beam

    CERN Document Server

    Sapinski, M; Guerrero, A; Koopman, J; Métral, E

    2009-01-01

    Carbon fibers are commonly used as moving targets in Beam Wire Scanners. Because of their thermomechanical properties they are very resistant to particle beams. Their strength deteriorates with time due to radiation damage and low-cycle thermal fatigue. In case of high intensity beams this process can accelerate and in extreme cases the fiber is damaged during a single scan. In this work a model describing the fiber temperature, thermionic emission and sublimation is discussed. Results are compared with fiber damage test performed on SPS beam in November 2008. In conclusions the limits of Wire Scanner operation on high intensity beams are drawn.

  2. Carbon beams, production and acceleration

    International Nuclear Information System (INIS)

    Belmont M, E.

    1979-01-01

    Installation, test and working conditions of a new negative-ion facility of the Salazar EN tandem are briefly described. Carbon is the material used for the test and the heavy ion stripping phenomenon is reviewed. (author)

  3. Carbon Fiber Damage in Particle Beam

    CERN Document Server

    Dehning, B; Kroyer, T; Meyer, M; Sapinski, M

    2011-01-01

    Carbon fibers are commonly used as moving targets in beam wire scanners. The heating of the fiber due to energy loss of the particles travelling through is simulated with Geant4. The heating induced by the beam electromagnetic field is estimated with ANSYS. The heat transfer and sublimation processes are modelled. Due to the model nonlinearity, a numerical approach based on discretization of the wire movement is used to solve it for particular beams. Radiation damage to the fiber is estimated with SRIM. The model is tested with available SPS and LEP data and a dedicated damage test on the SPS beam is performed followed by a post-mortem analysis of the wire remnants. Predictions for the LHC beams are made.

  4. Focused ion beam milling of carbon fibres

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  5. Development of stereotactic radiosurgery using carbon beams (carbon-knife)

    Science.gov (United States)

    Keawsamur, Mintra; Matsumura, Akihiko; Souda, Hikaru; Kano, Yosuke; Torikoshi, Masami; Nakano, Takashi; Kanai, Tatsuaki

    2018-02-01

    The aim of this research is to develop a stereotactic-radiosurgery (SRS) technique using carbon beams to treat small intracranial lesions; we call this device the carbon knife. A 2D-scanning method is adapted to broaden a pencil beam to an appropriate size for an irradiation field. A Mitsubishi slow extraction using third order resonance through a rf acceleration system stabilized by a feed-forward scanning beam using steering magnets with a 290 MeV/u initial beam energy was used for this purpose. Ridge filters for spread-out Bragg peaks (SOBPs) with widths of 5 mm, 7.5 mm, and 10 mm were designed to include fluence-attenuation effects. The collimator, which defines field shape, was used to reduce the lateral penumbra. The lateral-penumbra width at the SOBP region was less than 2 mm for the carbon knife. The penumbras behaved almost the same when changing the air gap, but on the other hand, increasing the range-shifter thickness mostly broadened the lateral penumbra. The physical-dose rates were approximate 6 Gy s-1 and 4.5 Gy s-1 for the 10  ×  10 mm2 and 5  ×  5 mm2 collimators, respectively.

  6. Electron beam processing of carbon fibre reinforced braided composites beams

    International Nuclear Information System (INIS)

    Halasz, L.; Zsigmond, B.; Czvikovszky, T.

    2002-01-01

    Complete text of publication follows. In this paper the possibility of producing a new type carbon fiber reinforced composite is examined by applying braiding, a well-known process of textile technology. The appearance of the new Hungarian carbon fiber with excellent mechanical properties in the market enables the development of newer type carbon fiber reinforced composites in the continuously widening range of engineering applications. Advanced hollow profiles, pipes and other composite products can be manufactured in continuous operation. A new way of composite production of this kind is the manufacturing of reinforcing structure by braiding technology producing a composite with sufficient mechanical properties from this cross directional fabric-like textile structure by impregnation. This manufacturing process can complete the variety of hollow products serving the same purpose as pultrusion or filament winding. This way a profile type framework element with a hollow cross section is manufactured having favorable mechanical properties. Owing to its small mass and high specific strength this product can be applied in dynamically loaded structures e.g. in the automotive industry. For crosslinking of the matrix the method of high-speed electron beam curing has been examined in order to reach continuous operation. The field of use and application of carbon fiber braided structures has a great chance especially in machine engineering and in the automotive industry. The main reason for this is that braiding processes are capable of producing structures having good mechanical properties at a low processing price. The mass of the composite load-bearing structure produced this way is one fifth of the steel product having similar geometry, and its specific mechanical properties are nearly as good as that of the most commonly applied semiproduct and structural component, the welded steel profile

  7. Carbon-11 in Bone and Lung Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Myers, W. G.; Hunter, Jr., W. W. [Ohio State University Health Center, Columbus, OH (United States)

    1969-05-15

    Radiocarbon-11 decays with 20.3-min half-life by emitting positrons with 1.0-MeV maximum energy. Two 511-keV {sup {+-}}{gamma}-photons almost always are emitted coincidentally with each disintegration, at 180 Degree-Sign to each other. This 'back-to-back' relationship makes it possible readily to locate small accumulations of {sup 11}C in vivo by opposed detectors connected by coincidence circuitry. The calculated narrow-beam half-thickness in water is more than 7 cm, to provide good penetration from deep organs, and with little scatter. Multimillicurie amounts of a mixture of {sup 11}CO and {sup 11}CO{sub 2} are generated readily in our small cyclotron when probe targets of B{sub 2}O{sub 3} are bombarded with protons, deuterons, or {sup 3}He{sup ++} ions. The {sup 11}CO is oxidized to {sup 11}CO{sub 2} by hopcalite placed in the vacuum line. Dogs with primary or metastatic bone tumours received {sup 11}CO{sub 2}, either by inhalation in a closed system, or in slightly basic solution in travenously. Scintigraphs, that were obtained within 10-20 min by means of a Nuclear-Chicago focused-collimator scanning machine, revealed significant accumulations of {sup 11}C at sites where bone erosion was demonstrable roentgenographically. Good pictures of dog lungs were obtained either with the mechanical scanner, or with our Nuclear-Chicago scintillation camera, after intravenous injection of 4-12 {mu}m diam. smoothly-rounded aggregates of SrCO{sub 3} that were formed in dextran-saline solution. These 'photon-carrier' aggregates have been made either with {sup 11}C; or with 2.8-h {sup 87m}Sr, which emits 388-keV gamma-rays. Alternatively, they might be made to 'carry' the 231-keV gamma-rays of 70-m in {sup 85m}Sr, that are advantageous for scintigraphy. The advent of Anger's positron camera, with choice of plane of prime interest, will provide opportunities to emphasize the maximum target/nontarget ratio in pictures of localized accumulations of {sup 11}C, as well as of {sup

  8. 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.

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

    Science.gov (United States)

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

    2012-02-01

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

  10. RC T beams strengthened to shear with carbon fiber composites

    Directory of Open Access Journals (Sweden)

    L. A. Spagnolo JR

    Full Text Available This paper presents the experimental data of the behavior of reinforced concrete beams strengthened to shear with carbon fiber composites. The tests were composed of eight T beams, b w=15 cm, h=40 cm, flange width 40 cm, flange height 8 cm, and length 300 cm, divided into two series with the same longitudinal steel reinforcement and a reference beam without strengthening in each series. The beams had two types of arrangement of internal steel stirrups. The test variables were the internal and external geometric ratio of the transverse reinforcement and the mechanical ratio of carbon fiber composites stirrups. All the beams were loaded at two points. The strengthened beams were submitted to a preloading and the strengthening was applied to the cracked beam. All the beams were designed in order to guarantee shear failure, and the ultimate load of the strengthened beams was 36% to 54% greater than the reference beams. The Cracking Sliding Model applied to the strengthened beams was evaluated and showed good agreement with the experimental results.

  11. Carbon beam dosimetry using VIP polymer gel and MRI

    DEFF Research Database (Denmark)

    Kantemiris, I; Petrokokkinos, L; Angelopoulos, A

    2009-01-01

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

  12. Regeneration of used activated carbon by electron beam irradiation

    International Nuclear Information System (INIS)

    Arai, H.; Hosono, M.; Zhu, G.; Miyata, T.

    1992-01-01

    The adsorbing power of granular activated carbons which adsorbed sodium laurylsulfate were most effectively recovered by irradiation of high energy electron beams in nitrogen stream, and the carbon was hardly lost by irradiation. The regeneration was induced mainly by microscopic heating of adsorption sites. Regeneration was also confirmed by adsorption endotherms. Regeneration cost was tentatively evaluated. (author)

  13. Selection of carbon beam therapy: biophysical models of carbon beam therapy.

    Science.gov (United States)

    Matsufuji, Naruhiro

    2018-03-01

    Variation in the relative biological effectiveness (RBE) within the irradiation field of a carbon beam makes carbon-ion radiotherapy unique and advantageous in delivering the therapeutic dose to a deep-seated tumor, while sparing surrounding normal tissues. However, it is crucial to consider the RBE, not only in designing the dose distribution during treatment planning, but also in analyzing the clinical response retrospectively. At the National Institute of Radiological Sciences, the RBE model was established based on the response of human salivary gland cells. The response was originally handled with a linear-quadratic model, and later with a microdosimetric kinetic model. Retrospective analysis with a tumor-control probability model of non-small cell cancer treatment revealed a steep dose response in the tumor, and that the RBE of the tumor was adequately estimated using the model. A commonly used normal tissue complication probability model has not yet fully been accountable for the variable RBE of carbon ions; however, analysis of rectum injury after prostate cancer treatment suggested a highly serial-organ structure for the rectum, and a steep dose response similar to that observed for tumors.

  14. Carbon 11 labelled phosgene: a new synthesis - medical interest

    International Nuclear Information System (INIS)

    Landais, P.

    1985-01-01

    This thesis describes a new synthesis of high specific radioactivity carbon-11 labelled phosgene. The latter is an important precursor for the labelling of radiopharmaceuticals used in Positron Emission Tomography. The synthesis is carried out in 10 minutes. First, the carbon-11 labelled methane ( 11 CH 4 ) is chlorinated into carbon tetrachloride on pumice impregnated with copper (II) chloride. A photochemical process had previously been studied but this reaction was strongly inhibited. Then the 11 C-carbon tetrachloride is oxidized into 11 C-phosgene on hot stainless. The 11 C-CGP 12177 has been labelled from this new 11 C-Phosgene synthesis for receptor studies which require high specific radioactivity. (author) [fr

  15. Carbon-11 labelled phosgene new synthesis - medical interest

    International Nuclear Information System (INIS)

    Landais, P.

    1985-09-01

    This thesis describes a new synthesis of high specific radioactivity carbon-11 labelled phosgene. The latter is an important precursor for the labelling of radiopharmaceuticals used in Positron Emission Tomography. The synthesis is carried out in 10 minutes. First, the carbon-11 labelled methane ( 11 CH 4 ) is chlorinated into carbon tetrachloride on pumice impregnated with copper (II) chloride. A photochemical process had previously been studied but this reaction was strongly inhibited. Then the 11 C-carbon tetrachloride is oxidized into 11 C-phosgene on hot stainless. The 11 C-CGP 12177 has been labelled from this new 11 C-Phosgene synthesis for receptor studies which require high specific radioactivity [fr

  16. New developments of 11C post-accelerated beams for hadron therapy and imaging

    Science.gov (United States)

    Augusto, R. S.; Mendonca, T. M.; Wenander, F.; Penescu, L.; Orecchia, R.; Parodi, K.; Ferrari, A.; Stora, T.

    2016-06-01

    Hadron therapy was first proposed in 1946 and is by now widespread throughout the world, as witnessed with the design and construction of the CNAO, HIT, PROSCAN and MedAustron treatment centres, among others. The clinical interest in hadron therapy lies in the fact that it delivers precision treatment of tumours, exploiting the characteristic shape (the Bragg peak) of the energy deposition in the tissues for charged hadrons. In particular, carbon ion therapy is found to be biologically more effective, with respect to protons, on certain types of tumours. Following an approach tested at NIRS in Japan [1], carbon ion therapy treatments based on 12C could be combined or fully replaced with 11C PET radioactive ions post-accelerated to the same energy. This approach allows providing a beam for treatment and, at the same time, to collect information on the 3D distributions of the implanted ions by PET imaging. The production of 11C ion beams can be performed using two methods. A first one is based on the production using compact PET cyclotrons with 10-20 MeV protons via 14N(p,α)11C reactions following an approach developed at the Lawrence Berkeley National Laboratory [2]. A second route exploits spallation reactions 19F(p,X)11C and 23Na(p,X)11C on a molten fluoride salt target using the ISOL (isotope separation on-line) technique [3]. This approach can be seriously envisaged at CERN-ISOLDE following recent progresses made on 11C+ production [4] and proven post-acceleration of pure 10C3/6+ beams in the REX-ISOLDE linac [5]. Part of the required components is operational in radioactive ion beam facilities or commercial medical PET cyclotrons. The driver could be a 70 MeV, 1.2 mA proton commercial cyclotron, which would lead to 8.1 × 10711C6+ per spill. This intensity is appropriate using 11C ions alone for both imaging and treatment. Here we report on the ongoing feasibility studies of such approach, using the Monte Carlo particle transport code FLUKA [6,7] to simulate

  17. New developments of {sup 11}C post-accelerated beams for hadron therapy and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Augusto, R.S., E-mail: r.s.augusto@cern.ch [European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland); Ludwig Maximilians – University of Munich, Munich (Germany); Mendonca, T.M.; Wenander, F. [European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland); Penescu, L. [MedAustron GmbH, Wiener Neustadt (Austria); Orecchia, R. [CNAO – Centro Nazionale di Adroterapia Oncologica per il trattamento dei tumori, Pavia (Italy); Parodi, K. [Ludwig Maximilians – University of Munich, Munich (Germany); Ferrari, A.; Stora, T. [European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland)

    2016-06-01

    Hadron therapy was first proposed in 1946 and is by now widespread throughout the world, as witnessed with the design and construction of the CNAO, HIT, PROSCAN and MedAustron treatment centres, among others. The clinical interest in hadron therapy lies in the fact that it delivers precision treatment of tumours, exploiting the characteristic shape (the Bragg peak) of the energy deposition in the tissues for charged hadrons. In particular, carbon ion therapy is found to be biologically more effective, with respect to protons, on certain types of tumours. Following an approach tested at NIRS in Japan [1], carbon ion therapy treatments based on {sup 12}C could be combined or fully replaced with {sup 11}C PET radioactive ions post-accelerated to the same energy. This approach allows providing a beam for treatment and, at the same time, to collect information on the 3D distributions of the implanted ions by PET imaging. The production of {sup 11}C ion beams can be performed using two methods. A first one is based on the production using compact PET cyclotrons with 10–20 MeV protons via {sup 14}N(p,α){sup 11}C reactions following an approach developed at the Lawrence Berkeley National Laboratory [2]. A second route exploits spallation reactions {sup 19}F(p,X){sup 11}C and {sup 23}Na(p,X){sup 11}C on a molten fluoride salt target using the ISOL (isotope separation on-line) technique [3]. This approach can be seriously envisaged at CERN-ISOLDE following recent progresses made on {sup 11}C{sup +} production [4] and proven post-acceleration of pure {sup 10}C{sup 3/6+} beams in the REX-ISOLDE linac [5]. Part of the required components is operational in radioactive ion beam facilities or commercial medical PET cyclotrons. The driver could be a 70 MeV, 1.2 mA proton commercial cyclotron, which would lead to 8.1 × 10{sup 711}C{sup 6+} per spill. This intensity is appropriate using {sup 11}C ions alone for both imaging and treatment. Here we report on the ongoing feasibility

  18. Production and characterization of supersonic carbon cluster beams

    International Nuclear Information System (INIS)

    Rohlfing, E.A.; Cox, D.M.; Kaldor, A.

    1984-01-01

    Laser vaporization of a substrate within the throat of a pulsed nozzle is used to generate a supersonic beam of carbon clusters. The neutral cluster beam is probed downstream by UV laser photoionization with time-of-flight mass analysis of the resulting photoions. Using graphite as the substrate, carbon clusters C/sub n/ for n = 1--190 have been produced having a distinctly bimodal cluster size distribution: (i) Both even and odd clusters for C/sub n/, 1 + /sub n/ signals are interpreted on the basis of cluster formation and stability arguments. Ionizing laser power dependences taken at several different photon energies are used to roughly bracket the carbon cluster ionization potentials, and, at high laser intensity, to observe the onset of multiphoton fragmentation. By treating the graphite rod with KOH, a greatly altered carbon cluster distribution with mixed carbon/potassium clusters of formula K 2 C/sub 2n/ is produced

  19. Improvement of carbon fiber surface properties using electron beam irradiation

    International Nuclear Information System (INIS)

    Pino, E.S.; Machado, L.D.B.; Giovedi, C.

    2007-01-01

    Carbon fiber-reinforced advance composites have been used for structural applications, mainly on account of their mechanical properties. The main factor for a good mechanical performance of carbon fiber-reinforced composite is the interfacial interaction between its components, which are carbon fiber and polymeric matrix. The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite. EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests. Experimental results showed that EB irradiation improved the tensile strength of carbon fiber samples. The maximum value in tensile strength was reached using doses of about 250 kGy. After breakage, the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated car- bon fibers were evaluated. SEM micrographs showed modifications on the carbon fiber surface. (authors)

  20. New developments of 11C post-accelerated beams for hadron therapy and imaging

    CERN Document Server

    Augusto, R S; Wenander, F; Penescu, L; Orecchia, R; Parodi, K; Ferrari, A; Stora, T

    2016-01-01

    Hadron therapy was first proposed in 1946 and is by now widespread throughout the world, as witnessed with the design and construction of the CNAO, HIT, PROSCAN and MedAustron treatment centres, among others. The clinical interest in hadron therapy lies in the fact that it delivers precision treatment of tumours, exploiting the characteristic shape (the Bragg peak) of the energy deposition in the tissues for charged hadrons. In particular, carbon ion therapy is found to be biologically more effective, with respect to protons, on certain types of tumours. Following an approach tested at NIRS in Japan [1], carbon ion therapy treatments based on 12C could be combined or fully replaced with 11C PET radioactive ions post-accelerated to the same energy. This approach allows providing a beam for treatment and, at the same time, to collect information on the 3D distributions of the implanted ions by PET imaging. The production of 11C ion beams can be performed using two methods. A first one is based on the production...

  1. Investigation of industrial-scale carbon dioxide reduction using pulsed electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, G. M.; Apruzese, J. P.; Petrova, Tz. B.; Wolford, M. F. [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375-5346 (United States)

    2016-03-14

    Carbon dioxide is the most important greenhouse gas contributing to global warming. To help mitigate increasing CO{sub 2} concentrations, we investigate a method of carbon dioxide reduction using high-power electron beams, which can be used on an industrial scale. A series of experiments are conducted in which the reduction of CO{sub 2} is measured for different gas compositions and power deposition rates. An electron beam deposition model is applied to compute reduction rates of CO{sub 2} and energy cost for breaking a CO{sub 2} molecule in flue gas and pure carbon dioxide at atmospheric pressure. For flue gas consisting of 82% N{sub 2}, 6% O{sub 2}, and 12% CO{sub 2}, the calculated energy cost is 85 eV per molecule. In order to dissociate 50% of the CO{sub 2} molecules, beam energy density deposition on the order of 20 J/cm{sup 3} is required. Electron beam irradiation of 12.6 liter gas volume containing 90% CO{sub 2} and 10% CH{sub 4} at beam energy density deposition of 4.2 J/cm{sup 3}, accumulated over 43 shots in a 20 min interval, reduced the CO{sub 2} concentration to 78%. Analogous experiments with a gas mixture containing 11.5% CO{sub 2}, 11.5% CH{sub 4}, and balance of Ar, reduced the CO{sub 2} concentration to below 11% with energy deposition 0.71 J/cm{sup 3}, accumulated over 10 shots in a 5 min interval. The experimental data and the theoretical predictions of CO{sub 2} reduction using pulsed electron beams are in agreement within the experimental error. Other techniques to enhance the removal of CO{sub 2} with pulsed electron beams are also explored, yielding new possible avenues of research.

  2. Electron beam induced emission from carbon plasmas

    International Nuclear Information System (INIS)

    Whetstone, S.; Kammash, T.

    1989-01-01

    Plasma use as a lasing medium has many potential advantages over conventional techniques including increased power levels and greater wavelength ranges. The basic concept is to heat and then rapidly cool a plasma forcing inversion through bottleneck creation between the recombination reaction populating a given energy level and the subsequent decay processes. Much effort has been devoted to plasmas heated by lasers and pinch devices. The authors are concerned here with electron beam heated plasmas focusing on the CIV 5g-4f transition occurring at 2530 Angstroms. These studies were initiated to provide theoretical support for experiments being performed at the University of Michigan using the Michigan Electron Long-Pulse Beam Accelerator (MELBA)

  3. Ultrafast Melting of Carbon Induced by Intense Proton Beams

    International Nuclear Information System (INIS)

    Pelka, A.; Guenther, M. M.; Harres, K.; Otten, A.; Roth, M.; Gregori, G.; Gericke, D. O.; Vorberger, J.; Glenzer, S. H.; Kritcher, A. L.; Heathcote, R.; Li, B.; Neely, D.; Kugland, N. L.; Niemann, C.; Makita, M.; Riley, D.; Mithen, J.; Schaumann, G.; Schollmeier, M.

    2010-01-01

    Laser-produced proton beams have been used to achieve ultrafast volumetric heating of carbon samples at solid density. The isochoric melting of carbon was probed by a scattering of x rays from a secondary laser-produced plasma. From the scattering signal, we have deduced the fraction of the material that was melted by the inhomogeneous heating. The results are compared to different theoretical approaches for the equation of state which suggests modifications from standard models.

  4. Bulk Cutting of Carbon Nanotubes Using Electron Beam Irradiation

    Science.gov (United States)

    Ziegler, Kirk J. (Inventor); Rauwald, Urs (Inventor); Hauge, Robert H. (Inventor); Schmidt, Howard K. (Inventor); Smalley, Richard E. (Inventor); Kittrell, W. Carter (Inventor); Gu, Zhenning (Inventor)

    2013-01-01

    According to some embodiments, the present invention provides a method for attaining short carbon nanotubes utilizing electron beam irradiation, for example, of a carbon nanotube sample. The sample may be pretreated, for example by oxonation. The pretreatment may introduce defects to the sidewalls of the nanotubes. The method is shown to produces nanotubes with a distribution of lengths, with the majority of lengths shorter than 100 tun. Further, the median length of the nanotubes is between about 20 nm and about 100 nm.

  5. Synthesis of 'no carrier added' carbon-11 fotemustine

    International Nuclear Information System (INIS)

    Lasne, M.C.; Piarraud, A.; Lalaoui, K.; Barre, L.; Derlon, J.M.; Giroux, B.

    1990-01-01

    Nitrosoureas are commonly used for chemotherapeutic treatment of some tumors and the search for new drugs less toxic amd more selective is always under investigation. Efficacy of fotemustine, a nitrosourea type compound in the treatment of malignant gliomas prompted us to label it with carbon-11 so that its pharmacokinetics and metabolic behavior in human brain tumors could be studied in vivo using PET. The synthetic pathway for labelling with carbon-11 is outlined

  6. Robotic synthesis of [carbon-11]methionine

    International Nuclear Information System (INIS)

    Korsakov, M.V.; Kisselev, M.Y.; Solovyov, D.; Horti, A.G.; Vasilev, A.; Nilsson, L.E.; Ulin, J.

    1992-01-01

    [ 11 C]Methionine was prepared in a fully automated robotic synthesis, using the SCANDITRONIX robotic system starting from [ 11 C]I and homocysteine thiolactone. The product was purified using solid phase extraction on anionic exchange cartridges. The decay corrected yield was 60% based on CH 3 I and 16 min synthesis time. The radiochemical purity was 98-99% and the chemical impurities were: homocysteine 0.05-0.07 mg/ml, homocystine 0.005 mg/ml, 'cold' methionine 0.03-0.05 mg/ml, and homocysteine thiolactone 0.0008-0.002 mg/ml. The total procedure takes 30 min from EOB. (author) 6 figs., 3 tabs

  7. Repair of reinforced concrete beams using carbon fiber reinforced polymer

    Directory of Open Access Journals (Sweden)

    Karzad Abdul Saboor

    2017-01-01

    Full Text Available This research paper is part of an ongoing research on the behaviour of Reinforced Concrete (RC beams retrofitted with Externally Bonded Carbon Fiber Reinforced Polymer (EB-CFRP. A total of 5 large-scale rectangular beams, previously damaged due to shear loading, were repaired and strengthened with EB-CFRP and tested in this study. The major cracks of the damaged beams were injected with epoxy and the beams were wrapped with 2 layers of EB-CFRP discrete strips with 100mm width and 150mm center to center spacing. The beams were instrumented and tested to failure under three points loading in simply supported configuration. The measured test parameters were the beams deflection, maximum load, and the strain in the FRP strips. The failure mode was also observed. The results showed that applying EB-FRP strips increased the shear strength significantly relative to the original shear capacity of the beam. The results demonstrate that the application of EB-FRP strips used in this study is an effective repair method that can be used to repair and strengthen damaged beams.

  8. Application of ion beams for polymeric carbon based biomaterials

    International Nuclear Information System (INIS)

    Evelyn, A.L.

    2001-01-01

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

  9. Carbon-11 labelling of an inhibitor of acetylcholinesterase: [11C]physostigmine

    International Nuclear Information System (INIS)

    Bonnot-Lours, S.; Crouzel, C.; Prenant, C.; Hinnen, F.

    1993-01-01

    Physostigmine, an alkaloid from calabar bean is a strong inhibitor of acetylcholinesterase and has been used clinically in the treatment of glaucoma, atropine intoxication, myasthenia gravis and more recently, in experimental trials in Alzheimer's disease. In order to study the AChE activity in the brain by positron emission tomography, we have undertaken the labelling of physostigmine with carbon-11. The synthesis involves the reaction of [ 11 C]methylisocyanate with eseroline. [ 11 C]Methylisocyanate was obtained by heating [ 11 C]acetylchloride with tetrabutylammonium azide in toluene. The synthesis of [ 11 C]CH 3 COC1 involves the carbonation of methylmagnesium bromide in THF with cyclotron produced [ 11 C]carbon dioxide and the addition of phthaloyl dichloride. The [ 11 C]methylisocyanate is distilled into a solution of eseroline in ether with a small piece of sodium. After 10 minutes at 25 o C, the solution is purified by HPLC and the appropriate fraction collected. Starting with 55.5 GBq (1.5 Ci) of [ 11 C]carbon dioxide, 0.92-1.48 GBq (25-40 mCi) of [ 11 C]Physostigmine are obtained 57 minutes after EOB. (author)

  10. Carbon-11 labelling of an inhibitor of acetylcholinesterase: [[sup 11]C]physostigmine

    Energy Technology Data Exchange (ETDEWEB)

    Bonnot-Lours, S.; Crouzel, C.; Prenant, C.; Hinnen, F. (CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot)

    1993-01-01

    Physostigmine, an alkaloid from calabar bean is a strong inhibitor of acetylcholinesterase and has been used clinically in the treatment of glaucoma, atropine intoxication, myasthenia gravis and more recently, in experimental trials in Alzheimer's disease. In order to study the AChE activity in the brain by positron emission tomography, we have undertaken the labelling of physostigmine with carbon-11. The synthesis involves the reaction of [[sup 11]C]methylisocyanate with eseroline. [[sup 11]C]Methylisocyanate was obtained by heating [[sup 11]C]acetylchloride with tetrabutylammonium azide in toluene. The synthesis of [[sup 11]C]CH[sub 3]COC1 involves the carbonation of methylmagnesium bromide in THF with cyclotron produced [[sup 11]C]carbon dioxide and the addition of phthaloyl dichloride. The [[sup 11]C]methylisocyanate is distilled into a solution of eseroline in ether with a small piece of sodium. After 10 minutes at 25[sup o]C, the solution is purified by HPLC and the appropriate fraction collected. Starting with 55.5 GBq (1.5 Ci) of [[sup 11]C]carbon dioxide, 0.92-1.48 GBq (25-40 mCi) of [[sup 11]C]Physostigmine are obtained 57 minutes after EOB. (author).

  11. 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......-dose curves deviate from predictions in the peak region, most pronounced at the distal edge of the peak. Conclusions: The used model and its implementation show a good overall agreement for quasi mono energetic measurements. Deviations in depth-dose measurements are mainly attributed to uncertainties...

  12. Constructing carbon nanotube junctions by Ar ion beam irradiation

    International Nuclear Information System (INIS)

    Ishaq, Ahmad; Ni Zhichun; Yan Long; Gong Jinlong; Zhu Dezhang

    2010-01-01

    Carbon nanotubes (CNTs) irradiated by Ar ion beams at elevated temperature were studied. The irradiation-induced defects in CNTs are greatly reduced by elevated temperature. Moreover, the two types of CNT junctions, the crossing junction and the parallel junction, were formed. And the CNT networks may be fabricated by the two types of CNT junctions. The formation process and the corresponding mechanism of CNT networks are discussed.

  13. FEM performance of concrete beams reinforced by carbon fiber bars

    Directory of Open Access Journals (Sweden)

    Hasan Hashim

    2018-01-01

    Full Text Available Concrete structures may be vulnerable to harsh environment, reinforcement with Fiber Reinforced Polymer (FRP bars have an increasing acceptance than normal steel. The nature of (FRP bar is (non-corrosive which is very beneficial for increased durability as well as the reinforcement of FRP bar has higher strength than steel bar. FRP usage are being specified more and more by public structural engineers and individual companies as main reinforcement and as strengthening of structures. Steel reinforcement as compared to (FRP reinforcement are decreasingly acceptable for structural concrete reinforcement including precast concrete, cast in place concrete, columns, beams and other components. Carbon Fiber Reinforcement Polymer (CFRP have a very high modulus of elasticity “high modulus” and very high tensile strength. In aerospace industry, CFRP with high modulus are popular among all FRPs because it has a high strength to weight ratio. In this research, a finite element models will be used to represent beams with Carbon Fiber Reinforcement and beams with steel reinforcement. The primary objective of the research is the evaluation of the effect of (CFR on beam reinforcement.

  14. Beams `96. Proceedings of the 11th international conference on high power particle beams. Vol. II

    Energy Technology Data Exchange (ETDEWEB)

    Jungwirth, K.; Ullschmied, J. [eds.

    1997-12-31

    The scientific programme of the conference carved the physics and technology of intense beams of charged particles, from basic experimental and theoretical problems of beam generation, transport and interaction with various media, up to beam and pulsed power applications in science and in industry. The breakdown of the papers by main topical groups is as follows: radiation sources, Z-pinches, accelerate related topics, astrophysics, ICF, ION Beam Physics, ION DIODES, ION RINGS, Beam plasma systems, diagnostic and others. This volumes contains 160 contributions, out which 133 have been input to INIS.

  15. Beams '96. Proceedings of the 11th international conference on high power particle beams. Vol. II

    International Nuclear Information System (INIS)

    Jungwirth, K.; Ullschmied, J.

    1996-01-01

    The scientific programme of the conference carved the physics and technology of intense beams of charged particles, from basic experimental and theoretical problems of beam generation, transport and interaction with various media, up to beam and pulsed power applications in science and in industry. The breakdown of the papers by main topical groups is as follows: radiation sources, Z-pinches, accelerate related topics, astrophysics, ICF, ION Beam Physics, ION DIODES, ION RINGS, Beam plasma systems, diagnostic and others. This volumes contains 160 contributions, out which 133 have been input to INIS

  16. Beams '96. Proceedings of the 11th international conference on high power particle beams. Vol. I

    International Nuclear Information System (INIS)

    Jungwirth, K.; Ullschmied, J.

    1996-01-01

    The Proceedings contain the full texts of 60 orals and 243 poster papers presented at the Conference. The scientific programme of the conference covered the physics and technology of intense beams of charged particles, from basic experimental and theoretical problems of beam generation, transport and interaction with various media, up to beam and pulsed power applications in science and in industry. The breakdown of the papers by main topical groups is as follows: electron beams, beam-plasma systems, high-power microwaves (62), imploding liners, z-pinches, plasma foci (53), pulsed power technology and its applications (53), ion beams and ICF (41), industrial applications of electron and ion beams (36), radiation sources (23), diagnostics (14), and others (21). (J.U.)

  17. Beams `96. Proceedings of the 11th international conference on high power particle beams. Vol. I

    Energy Technology Data Exchange (ETDEWEB)

    Jungwirth, K.; Ullschmied, J. [eds.

    1997-12-31

    The Proceedings contain the full texts of 60 orals and 243 poster papers presented at the Conference. The scientific programme of the conference covered the physics and technology of intense beams of charged particles, from basic experimental and theoretical problems of beam generation, transport and interaction with various media, up to beam and pulsed power applications in science and in industry. The breakdown of the papers by main topical groups is as follows: electron beams, beam-plasma systems, high-power microwaves (62), imploding liners, z-pinches, plasma foci (53), pulsed power technology and its applications (53), ion beams and ICF (41), industrial applications of electron and ion beams (36), radiation sources (23), diagnostics (14), and others (21). (J.U.).

  18. Radiation dose estimates for carbon-11-labelled PET tracers

    International Nuclear Information System (INIS)

    Aart, Jasper van der; Hallett, William A.; Rabiner, Eugenii A.; Passchier, Jan; Comley, Robert A.

    2012-01-01

    Introduction: Carbon-11-labelled positron emission tomography (PET) tracers commonly used in biomedical research expose subjects to ionising radiation. Dosimetry is the measurement of radiation dose, but also commonly refers to the estimation of health risk associated with ionising radiation. This review describes radiation dosimetry of carbon-11-labelled molecules in the context of current PET research and the most widely used regulatory guidelines. Methods: A MEDLINE literature search returned 42 articles; 32 of these were based on human PET data dealing with radiation dosimetry of carbon-11 molecules. Radiation burden expressed as effective dose and maximum absorbed organ dose was compared between tracers. Results: All but one of the carbon-11-labelled PET tracers have an effective dose under 9 μSv/MBq, with a mean of 5.9 μSv/MBq. Data show that serial PET scans in a single subject are feasible for the majority of radiotracers. Conclusion: Although differing in approach, the two most widely used regulatory frameworks (those in the USA and the EU) do not differ substantially with regard to the maximum allowable injected activity per PET study. The predictive validity of animal dosimetry models is critically discussed in relation to human dosimetry. Finally, empirical PET data are related to human dose estimates based on homogenous distribution, generic models and maximum cumulated activities. Despite the contribution of these models to general risk estimation, human dosimetry studies are recommended where continued use of a new PET tracer is foreseen.

  19. One carbon metabolism in SAR11 pelagic marine bacteria.

    Directory of Open Access Journals (Sweden)

    Jing Sun

    Full Text Available The SAR11 Alphaproteobacteria are the most abundant heterotrophs in the oceans and are believed to play a major role in mineralizing marine dissolved organic carbon. Their genomes are among the smallest known for free-living heterotrophic cells, raising questions about how they successfully utilize complex organic matter with a limited metabolic repertoire. Here we show that conserved genes in SAR11 subgroup Ia (Candidatus Pelagibacter ubique genomes encode pathways for the oxidation of a variety of one-carbon compounds and methyl functional groups from methylated compounds. These pathways were predicted to produce energy by tetrahydrofolate (THF-mediated oxidation, but not to support the net assimilation of biomass from C1 compounds. Measurements of cellular ATP content and the oxidation of (14C-labeled compounds to (14CO(2 indicated that methanol, formaldehyde, methylamine, and methyl groups from glycine betaine (GBT, trimethylamine (TMA, trimethylamine N-oxide (TMAO, and dimethylsulfoniopropionate (DMSP were oxidized by axenic cultures of the SAR11 strain Ca. P. ubique HTCC1062. Analyses of metagenomic data showed that genes for C1 metabolism occur at a high frequency in natural SAR11 populations. In short term incubations, natural communities of Sargasso Sea microbial plankton expressed a potential for the oxidation of (14C-labeled formate, formaldehyde, methanol and TMAO that was similar to cultured SAR11 cells and, like cultured SAR11 cells, incorporated a much larger percentage of pyruvate and glucose (27-35% than of C1 compounds (2-6% into biomass. Collectively, these genomic, cellular and environmental data show a surprising capacity for demethylation and C1 oxidation in SAR11 cultures and in natural microbial communities dominated by SAR11, and support the conclusion that C1 oxidation might be a significant conduit by which dissolved organic carbon is recycled to CO(2 in the upper ocean.

  20. Measurement of carbon fixation and allocation using 11C-labeled carbon dioxide

    International Nuclear Information System (INIS)

    Strain, B.R.; Goeschl, J.D.; Jaeger, C.H.; Fares, Y.; Magnuson, C.E.; Nelson, C.E.

    1983-01-01

    This paper describes the use of continuously produced and applied 11 C in measurements of carbon dioxide assimilation and C movement in plant research. This technique differs from the pulsing type 11 C research underway in other laboratories by being continuous and on-line with computer analysis making steady-state measurements of carbon fixation and movement possible. The studies to be described here make clear the advantages of using continuously produced and applied short half-lived isotopes

  1. Imaging for carbon translocation to a fruit of tomato with carbon-11-labeled carbon dioxide and positron emission tomography

    International Nuclear Information System (INIS)

    Kawachi, N.; Suzui, N.; Ishii, S.; Fujimaki, S.; Ishioka, N.; Kikuchi, K.; Watanbe, H.

    2009-01-01

    Carbon kinetics in the fruit is an agricultural issue on the growth and development of the fruit to be harvested. Particularly, photo-assimilate translocation and distribution are important topics for understanding the mechanism. In the present work, carbon-11 ( 11 C) labeled photo-assimilate translocation into fruits of tomato has been imaged using carbon-11-labeled carbon dioxide and the positron emission tomography (PET). Dynamic PET data of gradual increasing of 11 C activity and its distribution is acquired quantitatively in intact plant body. This indicates that the three dimensional photo-assimilate translocation into the fruits is imaged successfully and carbon kinetics is analyzed to understand the plant physiology and nutrition. (authors)

  2. Captive solvent methods for fast, simple carbon-11 radioalkylations

    International Nuclear Information System (INIS)

    Jewett, D.M.; Mangner, T.J.; Watkins, G.L.

    1991-01-01

    Carbon-11 labeled radiopharmaceuticals for receptor studies usually require final purification by high performance liquid chromatography (HPLC). A significant simplification of the apparatus is possible if the radiolabeling reaction can be done directly in the HPLC injection circuit. Captive solvent methods in which the reaction is done in a small volume of solvent absorbed in a porous solid matrix are a general approach to this problem. For N-methylations with [ 11 C] methyl iodide, a basic catalyst may be incorporated in the polymeric or alumina solid phase. Reaction volumes are from 20 to 100 ML. Often no heating or cooling of the reaction column is necessary. The syntheses of [ 11 C]PK11195 and [ 11 C] flumazenil are described to illustrate some of the advantages and limitations of captive solvent methods

  3. Focused Ion Beam Nanopatterning for Carbon Nanotube Ropes Based Sensor

    Directory of Open Access Journals (Sweden)

    Vera LA FERRARA

    2007-11-01

    Full Text Available Focused Ion Beam (FIB technology has been used to realize electrode patterns for contacting Single Walled Carbon Nanotubes (SWCNTs ropes for chemical gas sensor applications. Two types of transducers, based on a single rope and on bundles, have been realized starting from silicon/Si3N4 substrate. Electrical behaviour, at room temperature, in toxic gas environments, has been investigated and compared to evaluate contribution of a single rope based sensor respect to bundles one. For all the devices, upon exposure to NO2 and NH3, the conductance has been found to increase or decrease respectively. Conductance signal is stronger for sensor based on bundles, but it also evident that response time in NO2 is faster for device based on a single rope. FIB technology offers, then, the possibility to contact easily a single sensitive nanowire, as carbon nanotube rope.

  4. Electron beam influence on the carbon contamination of electron irradiated hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Hristu, Radu; Stanciu, Stefan G.; Tranca, Denis E.; Stanciu, George A.

    2015-01-01

    Highlights: • Carbon contamination mechanisms of electron-beam-irradiated hydroxyapatite. • Atomic force microscopy phase imaging used to detect carbon contamination. • Carbon contamination dependence on electron energy, irradiation time, beam current. • Simulation of backscattered electrons confirms the experimental results. - Abstract: Electron beam irradiation which is considered a reliable method for tailoring the surface charge of hydroxyapatite is hindered by carbon contamination. Separating the effects of the carbon contamination from those of irradiation-induced trapped charge is important for a wide range of biological applications. In this work we focus on the understanding of the electron-beam-induced carbon contamination with special emphasis on the influence of the electron irradiation parameters on this phenomenon. Phase imaging in atomic force microscopy is used to evaluate the influence of electron energy, beam current and irradiation time on the shape and size of the resulted contamination patterns. Different processes involved in the carbon contamination of hydroxyapatite are discussed

  5. A simulation study of a C-shaped in-beam PET system for dose verification in carbon ion therapy

    International Nuclear Information System (INIS)

    Jung An, Su; Beak, Cheol-Ha; Lee, Kisung; Hyun Chung, Yong

    2013-01-01

    The application of hadrons such as carbon ions is being developed for the treatment of cancer. The effectiveness of such a technique is due to the eligibility of charged particles in delivering most of their energy near the end of the range, called the Bragg peak. However, accurate verification of dose delivery is required since misalignment of the hadron beam can cause serious damage to normal tissue. PET scanners can be utilized to track the carbon beam to the tumor by imaging the trail of the hadron-induced positron emitters in the irradiated volume. In this study, we designed and evaluated (through Monte Carlo simulations) an in-beam PET scanner for monitoring patient dose in carbon beam therapy. A C-shaped PET and a partial-ring PET were designed to avoid interference between the PET detectors and the therapeutic carbon beam delivery. Their performance was compared with that of a full-ring PET scanner. The C-shaped, partial-ring, and full-ring scanners consisted of 14, 12, and 16 detector modules, respectively, with a 30.2 cm inner diameter for brain imaging. Each detector module was composed of a 13×13 array of 4.0 mm×4.0 mm×20.0 mm LYSO crystals and four round 25.4 mm diameter PMTs. To estimate the production yield of positron emitters such as 10 C, 11 C, and 15 O, a cylindrical PMMA phantom (diameter, 20 cm; thickness, 20 cm) was irradiated with 170, 290, and 350 AMeV 12 C beams using the GATE code. Phantom images of the three types of scanner were evaluated by comparing the longitudinal profile of the positron emitters, measured along the carbon beam as it passed a simulated positron emitter distribution. The results demonstrated that the development of a C-shaped PET scanner to characterize carbon dose distribution for therapy planning is feasible.

  6. Improvement of carbon fibre surface properties using electron beam irradiation

    International Nuclear Information System (INIS)

    Eddy Segura Pino; Luci Diva Brocardo Machado; Claudia Giovedi

    2006-01-01

    Carbon fiber-reinforced advance composites have been used for structural applications, mainly due to their mechanical properties, and additional features such as high strength-to-weight ratio, stiffness-to-weight ratio, corrosion resistance and wear properties. The main factor for a good mechanical performance of carbon fiber-reinforced composite is the interfacial interaction between the components that are fiber and polymeric matrix. The greatest challenge is to improve adhesion between components having elasticity modulus which differ by orders of magnitude and furthermore they are immiscible in each other. Another important factor is the sizing material on the carbon fiber, which protects the carbon fiber filaments and must be compatible with the matrix material in order to improve the adhesion process. The interaction of ionizing radiation from electron beam can induce in the irradiated material the formation of very active centers and free radicals. Further evolution of these active species can significantly modify structure and properties not only in the irradiated polymeric matrix but also on the fiber surface. So that, fiber and matrix play an important role in the production of chemical bonds, which promote better adhesion between both materials improving the composite mechanical performance. The aim of this work was to improve the surface properties of the carbon fiber surface using ionizing radiation from an electron beam in order to obtain improvement of the adhesion properties in the resulted composite. Commercial carbon fiber roving of high tensile strength with 12 000 filaments named 12 k, and sizing material of epoxy resin modified by ester groups was studied. EB irradiation has been carried out at the Institute for Nuclear and Energy Research (IPEN) facilities using a 1.5 MeV 37.5 kW Dynamitron electron accelerator model JOB-188. Rovings of carbon fibers with 1.78 g cm -3 density and 0.13 mm thickness were irradiated with 0.555 MeV, 6.43 mA and

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

    International Nuclear Information System (INIS)

    Uzawa, Akiko; Ando, Koichi; Furusawa, Yoshiya

    2007-01-01

    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)

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

    International Nuclear Information System (INIS)

    Inaji, Motoki; Okauchi, Takashi; Nagai, Yuji; Nojima, Kumie; Suhara, Tetsuya

    2004-01-01

    The present study was designed to make a new Parkinson disease model using carbon ion beam. In this year, we irradiated right middle forebrain bundle of adult 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 which was developed in this year. In 4 weeks after the irradiation, we performed methamphetamine induced rotation test and the autoradiography measurement on dopamine transporter using [ 11 C]PE2I to assess degeneration of dopaminergic neurons in caudate putamen (Cpu). As a result, ipsilateral rotation was observed and the distributions of dopamine transporter in the striatum decreased significantly. These results are similar to those of 6-OHDA lesioned rats, and indicate validity of this model. (author)

  9. Alanine Radiation Detectors in Therapeutic Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo

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

  10. The proliferative response of mouse intestinal crypts during fractionated irradiation of carbon beams

    International Nuclear Information System (INIS)

    Abo, M.; Abe, Y.; Mariya, Y.; Ando, K.

    2000-01-01

    Clonogenic assay of jejunal crypt during carbon beam and X-ray irradiations was performed. Fractionation with top-up dose assay revealed carbon beam irradiations caused more damage than X-ray did. To clarify this problem is urgent. (author)

  11. SU-E-J-144: Low Activity Studies of Carbon 11 Activation Via GATE Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Elmekawy, A; Ewell, L [Hampton University, Hampton, VA (United States); Butuceanu, C; Qu, L [Hampton University Proton Therapy Institute, Hampton, VA (United States)

    2015-06-15

    Purpose: To investigate the behavior of a Monte Carlo simulation code with low levels of activity (∼1,000Bq). Such activity levels are expected from phantoms and patients activated via a proton therapy beam. Methods: Three different ranges for a therapeutic proton radiation beam were examined in a Monte Carlo simulation code: 13.5, 17.0 and 21.0cm. For each range, the decay of an equivalent length{sup 11}C source and additional sources of length plus or minus one cm was studied in a benchmark PET simulation for activities of 1000, 2000 and 3000Bq. The ranges were chosen to coincide with a previous activation study, and the activities were chosen to coincide with the approximate level of isotope creation expected in a phantom or patient irradiated by a therapeutic proton beam. The GATE 7.0 simulation was completed on a cluster node, running Scientific Linux Carbon 6 (Red Hat©). The resulting Monte Carlo data were investigated with the ROOT (CERN) analysis tool. The half-life of{sup 11}C was extracted via a histogram fit to the number of simulated PET events vs. time. Results: The average slope of the deviation of the extracted carbon half life from the expected/nominal value vs. activity showed a generally positive value. This was unexpected, as the deviation should, in principal, decrease with increased activity and lower statistical uncertainty. Conclusion: For activity levels on the order of 1,000Bq, the behavior of a benchmark PET test was somewhat unexpected. It is important to be aware of the limitations of low activity PET images, and low activity Monte Carlo simulations. This work was funded in part by the Philips corporation.

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  13. Ionized carbon investigation (spectroscopic terms, radiative lifetimes) using ion beams

    International Nuclear Information System (INIS)

    Buchet-Poulizac, M.-C.

    1974-01-01

    The spectra of carbon in all its ionization states were studied by the beam-foil technique, from the far ultraviolet (30A) to 6000A. This excitation process gives the spectra of strongly charged ions with great intensity and favours population of the high levels of these ions. It has led to new identifications, mainly in the CIV, CV, and CVI spectra. The results of radiative lifetime measurements are given for many levels of C II, C III, C IV and C V. The chief cause of error on these measurements is the cascade phenomenon. Various methods of decay curve analysis accounting for these processes were examined and showed that lifetime values of precision better than 10% can be obtained. The transition probabilities were estimated from the lifetime measurements whenever possible. The spectra obtained in the laboratory were compared with those observed in the Wolf-Rayet stars of the carbon sequence. The similarities and dissimilarities which appear yield information on the physical conditions prevailing in the atmosphere of these stars [fr

  14. Electron beam irradiation effects on carbon fiber reinforced PEEK composite

    International Nuclear Information System (INIS)

    Sasuga, Tsuneo; Hagiwara, Miyuki; Odajima, Tosikazu; Sakai, Hideo; Nakakura, Toshiyuki; Masutani, Masahiro.

    1987-03-01

    Carbon fiber(CF) reinforced composites, using polyarylether-sulfone (PES) or polyarylether-ether-ketone (PEEK) as matrix material, were prepared and their electron beam irradiation effects were studied on the basis of changes in mechanical and dynamic viscoelastic properties and observation of fracture surfaces. The flexural strength of PES-CF composite decreased to 70 % of the initial strength after the irradiation of 3 MGy and 40 % after 15 MGy. The change in the profile of stress-strain (S-S) curves and fractographic observation by electron microscopy indicated that this composite irradiated with over 3 MGy was fractured by delamination caused by to the degradation of matrix polymer. The mechanical properties of PEEK-CF composite were scarcely decreased even after irradiated up to 180 MGy and this composite showed very high radiation resistance. The change in the profile of S-S curves and fractographic observation showed that this composite fractured due to destruction of fiber in the dose range less than 180 MGy, indicating that PEEK was excellent matrix material used in high radiation field. PEEK-PES-CF composite which was composed of the carbon fibers coated with PES solution showed less radiation resistance compared with PEEK-CF composite; the flexural strength decreased to 85 % of the initial value after the irradiation with 90 MGy. It was revealed from the changes in the profile of S-S curve that the specimen irradiated over 120 MGy was fractured due to not only fiber destruction but delamination. Deterioration mechanism of PEEK-PES-CF composite was studied by dynamic viscoelastic measurements in connection with the damage on matrix-fiber interface. It was suggested that the deterioration in mechanical properties of this composite was caused by the degradation of PES that coated on the surface of the carbon fibers. (author)

  15. CERN Accelerator School: Intensity Limitations in Particle Beams | 2-11 November

    CERN Multimedia

    2015-01-01

    Registration is now open for the CERN Accelerator School’s specialised course on Intensity Limitations in Particle Beams, to be held at CERN between 2 and 11 November 2015.   This course will mainly be of interest to staff in accelerator laboratories, university departments and companies manufacturing accelerator equipment. Many accelerators and storage rings, whether intended for particle physics experiments, synchrotron light sources or industrial applications, require beams of high brightness and the highest possible intensities. A good understanding of the possible limitations is required to achieve the desired performance. The programme for this course will cover the interaction of beams with their surroundings, with other beams and further collective effects. Lectures on the effects and possible mitigations will be complemented by tutorials. Further information can be found at: http://cas.web.cern.ch/cas/Intensity-Limitations-2015/IL-advert.html   http:/...

  16. Optical propagation of the HE11 mode and Gaussian beams in hollow circular waveguides

    International Nuclear Information System (INIS)

    Crenn, J.P.

    1993-05-01

    The propagation of the HE 11 mode and Gaussian beams in hollow oversized circular waveguides is analyzed using optical theories. Different types of waveguides are considered: hollow dielectric or conducting waveguides, dielectric-lined waveguides, corrugated waveguides. General formulas are derived which give the power transmission through these different guides. The best wall materials and structures are determined from a comparison of the waveguide transmissions, at the infrared and millimeter wavelengths. The question of the coupling between the HE 11 mode and Gaussian beams is discussed and from a review of coupling coefficients derived before, an optimum value is pointed out. The problem of matching a Gaussian beam into circular waveguides in order to achieve the maximum power transmission is analyzed

  17. Ethanolic carbon-11 chemistry: The introduction of green radiochemistry

    International Nuclear Information System (INIS)

    Shao, Xia; Fawaz, Maria V.; Jang, Keunsam; Scott, Peter J.H.

    2014-01-01

    The principles of green chemistry have been applied to a radiochemistry setting. Eleven carbon-11 labeled radiopharmaceuticals have been prepared using ethanol as the only organic solvent throughout the entire manufacturing process. The removal of all other organic solvents from the process simplifies production and quality control (QC) testing, moving our PET Center towards the first example of a green radiochemistry laboratory. All radiopharmaceutical doses prepared are suitable for clinical use. - Highlights: • We report application of the principles of green chemistry to a radiochemistry setting. • Radiopharmaceuticals are prepared using ethanol as the only organic solvent. • Green radiochemistry simplifies production and QC in busy clinical production laboratories. • Residual solvent analysis can be relegated to a quarterly or annual QC test

  18. Testing the YerPhI Transimpedance Preamplifier with PPC by the T11 PS Beam

    CERN Document Server

    Parlakian, L K; CERN. Geneva; Martmianov, A N

    1997-01-01

    We report on the test of the preamplifier, described in [1], by the 3 GeV/c positive particle T11 beam of PS/CERN. We have measured the amplitude and time of flight spectrum, the time resolution and detection efficiency. The preamplifier has shown a stable work and hardness to the chamber discharge. The test results are presented.

  19. Conversion of no-carrier-added [11C]carbon dioxide to [11C]carbon monoxide on molybdenum for the synthesis of 11C-labelled aromatic ketones

    International Nuclear Information System (INIS)

    Zeisler, S.K.; Nader, M.; Theobald, A.; Oberdorfer, F.

    1997-01-01

    A new method for the efficient conversion of no-carrier-added [ 11 C]carbon dioxide into [ 11 C]carbon monoxide is described. [ 11 C]Carbon dioxide produced by proton bombardment of ultra high purity nitrogen is pre-concentrated in a cryo trap and then passed through a quartz tube filled with a mesh of thin molybdenum wire heated to 850 o C. [ 11 C]Carbon dioxide readily reacts with molybdenum to form [ 11 C]carbon monoxide and molybdenum(IV) oxide. The latter also reduces carbon dioxide to carbon monoxide and helps improve the performance of the converter. [ 11 C]Carbon monoxide is purified from remaining [ 11 C]carbon dioxide and collected in a small silica trap from which it is eluted into a reaction mixture for the palladium-mediated synthesis of a 11 C-labelled aromatic ketone. Radiochemical yields of up to 81% (decay-corrected) for [ 11 C]carbon monoxide were obtained. Radiochemical purity and specific radioactivity of both [ 11 C]carbon monoxide and the 11 C-labelled ketone are sufficient for nuclear medical studies with PET. (Author)

  20. Analysis of mutagenic effects induced by carbon beams at different LET in a red yeast strain

    International Nuclear Information System (INIS)

    Sun Haining; Wang Jufang; Ma Shuang; Lu Dong; Wu Xin; Li Wenjian

    2011-01-01

    To evaluate inactive and mutagenic effects of carbon beam at different LET, the inactivation cross section and mutation cross section induced by carbon beams of different LET values were investigated in a red yeast strain Rhodotorula glutinis AY 91015. It was found that the maximum inactivation cross section of 4.37μm 2 , which was very close to the average nucleus cross section, was at LET of 120.0 keV/μm. The maximum mutation cross section was at LET of 96.0 keV/μm. Meanwhile, the highest mutagenicity of carbon ion was found around 58.2 keV/μm. It implied that the most efficient LET to induce mutation in survival yeasts was 58.2 keV/μm, which corresponded to energy of 35 MeV/u carbon beam. The most effective carbon beam to induce inactivation and mutation located at different energy region. (authors)

  1. Electron Cloud in Steel Beam Pipe vs Titanium Nitride Coated and Amorphous Carbon Coated Beam Pipes in Fermilab's Main Injector

    Energy Technology Data Exchange (ETDEWEB)

    Backfish, Michael

    2013-04-01

    This paper documents the use of four retarding field analyzers (RFAs) to measure electron cloud signals created in Fermilab’s Main Injector during 120 GeV operations. The first data set was taken from September 11, 2009 to July 4, 2010. This data set is used to compare two different types of beam pipe that were installed in the accelerator. Two RFAs were installed in a normal steel beam pipe like the rest of the Main Injector while another two were installed in a one meter section of beam pipe that was coated on the inside with titanium nitride (TiN). A second data run started on August 23, 2010 and ended on January 10, 2011 when Main Injector beam intensities were reduced thus eliminating the electron cloud. This second run uses the same RFA setup but the TiN coated beam pipe was replaced by a one meter section coated with amorphous carbon (aC). This section of beam pipe was provided by CERN in an effort to better understand how an aC coating will perform over time in an accelerator. The research consists of three basic parts: (a) continuously monitoring the conditioning of the three different types of beam pipe over both time and absorbed electrons (b) measurement of the characteristics of the surrounding magnetic fields in the Main Injector in order to better relate actual data observed in the Main Injector with that of simulations (c) measurement of the energy spectrum of the electron cloud signals using retarding field analyzers in all three types of beam pipe.

  2. Analytical, Numerical and Experimental Examination of Reinforced Composites Beams Covered with Carbon Fiber Reinforced Plastic

    Science.gov (United States)

    Kasimzade, A. A.; Tuhta, S.

    2012-03-01

    In the article, analytical, numerical (Finite Element Method) and experimental investigation results of beam that was strengthened with fiber reinforced plastic-FRP composite has been given as comparative, the effect of FRP wrapping number to the maximum load and moment capacity has been evaluated depending on this results. Carbon FRP qualitative dependences have been occurred between wrapping number and beam load and moment capacity for repair-strengthen the reinforced concrete beams with carbon fiber. Shown possibilities of application traditional known analysis programs, for the analysis of Carbon Fiber Reinforced Plastic (CFRP) strengthened structures.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  4. Interaction of the CERN Large Hadron Collider (LHC) Beam with Carbon Collimators

    CERN Document Server

    Schmidt, R; Hoffmann, Dieter H H; Kadi, Y; Shutov, A; Piriz, AR

    2006-01-01

    The LHC will operate at an energy of 7 TeV with a luminosity of 1034cm-2s-1. This requires two beams, each with 2808 bunches. The energy stored in each beam of 362 MJ. In a previous paper the mechanisms causing equipment damage in case of a failure of the machine protection system was discussed, assuming that the entire beam is deflected into a copper target [1, 2]. Another failure scenario is the deflection of beam into carbon material. Carbon collimators and beam absorbers are installed in many locations around the LHC to diffuse or absorb beam losses. Since the collimator jaws are close to the beam, it is very likely that they are hit first when the beam is accidentally deflected. Here we present the results of two-dimensional hydrodynamic simulations of the heating of a solid carbon cylinder irradiated by the LHC beam with nominal parameters, carried out using the BIG-2 computer code [3] while the energy loss of the 7 TeV protons in carbon is calculated using the well known FLUKA code [4]. Our calculation...

  5. Bright luminance from silicon dioxide film with carbon nanotube electron beam exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Su Woong; Hong, Ji Hwan; Kang, Jung Su; Callixte, Shikili; Park, Kyu Chang, E-mail: kyupark@khu.ac.kr

    2016-02-15

    We observed the bright bluish-white luminescence with naked eye from carbon nanotube electron beam exposed silicon dioxide (SiO{sub 2}) thin film on Si substrate. The luminescence shows a peak intensity at 2.7 eV (460 nm) with wide spread up to 600 nm after the C-beam exposed on SiO{sub 2} thin film. The C-beam exposure system is composed of carbon nanotube emitters as electron beam source. The brightness strongly depend on the exposure condition. Luminescence characteristic was optimized by C-beam adjustment to observe with the naked eye. The cause of luminescence in the C-beam exposed SiO{sub 2} thin film is analyzed by CL microscopy, FT-IR, AFM and ellipsometer. Decrease of Si–O bonding was observed after C-beam exposure, and this reveals that oxygen deficient defects which are irradiation-sensitive cause 2.7 eV peak of luminescence. - Highlights: • We observed bright luminescence for SiO{sub 2} thin film with naked eye by carbon nanotube electron beam (C-beam) exposure technique. • The bright luminance from C-beam exposed SiO{sub 2} film will open novel silicon optoelectronics.

  6. Nuclear reactions with 11C and 14O radioactive ion beams

    International Nuclear Information System (INIS)

    Guo, Fanqing

    2004-01-01

    Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the disappearance of the Z = 8

  7. Carbon-11-methionine positron emission tomography imaging of chordoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong [Department of Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Department of Medical Imaging, Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, 263-8555, Chiba (Japan); Yoshikawa, Kyosan; Tamura, Katsumi; Sagou, Kenji; Kandatsu, Susumu [Clinical Diagnosis Section, National Institute of Radiological Sciences, Chiba (Japan); Tian, Mei; Suhara, Tetsuya; Suzuki, Kazutoshi; Tanada, Shuji [Department of Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Tsujii, Hirohiko [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan)

    2004-09-01

    Chordoma is a rare malignant bone tumor that arises from notochord remnants. This is the first trial to investigate the utility of {sup 11}C-methionine (MET) positron emission tomography (PET) in the imaging of chordoma before and after carbon-ion radiotherapy (CIRT). Fifteen patients with chordoma were investigated with MET-PET before and after CIRT and the findings analyzed visually and quantitatively. Tumor MET uptake was evaluated by tumor-to-nontumor ratio (T/N ratio). In 12 (80%) patients chordoma was clearly visible in the baseline MET-PET study with a mean T/N ratio of 3.3{+-}1.7. The MET uptake decreased significantly to 2.3{+-}1.4 after CIRT (P<0.05). A significant reduction in tumor MET uptake of 24% was observed after CIRT. Fourteen (93%) patients showed no local recurrence after CIRT with a median follow-up time of 20 months. This study has demonstrated that MET-PET is feasible for imaging of chordoma. MET-PET could provide important tumor metabolic information for the therapeutic monitoring of chordoma after CIRT. (orig.)

  8. Carbon-11-methionine positron emission tomography imaging of chordoma

    International Nuclear Information System (INIS)

    Zhang, Hong; Yoshikawa, Kyosan; Tamura, Katsumi; Sagou, Kenji; Kandatsu, Susumu; Tian, Mei; Suhara, Tetsuya; Suzuki, Kazutoshi; Tanada, Shuji; Tsujii, Hirohiko

    2004-01-01

    Chordoma is a rare malignant bone tumor that arises from notochord remnants. This is the first trial to investigate the utility of 11 C-methionine (MET) positron emission tomography (PET) in the imaging of chordoma before and after carbon-ion radiotherapy (CIRT). Fifteen patients with chordoma were investigated with MET-PET before and after CIRT and the findings analyzed visually and quantitatively. Tumor MET uptake was evaluated by tumor-to-nontumor ratio (T/N ratio). In 12 (80%) patients chordoma was clearly visible in the baseline MET-PET study with a mean T/N ratio of 3.3±1.7. The MET uptake decreased significantly to 2.3±1.4 after CIRT (P<0.05). A significant reduction in tumor MET uptake of 24% was observed after CIRT. Fourteen (93%) patients showed no local recurrence after CIRT with a median follow-up time of 20 months. This study has demonstrated that MET-PET is feasible for imaging of chordoma. MET-PET could provide important tumor metabolic information for the therapeutic monitoring of chordoma after CIRT. (orig.)

  9. Comparison of Biological Effectiveness of Carbon-Ion Beams in Japan and Germany

    International Nuclear Information System (INIS)

    Uzawa, Akiko; Ando, Koichi; Koike, Sachiko; Furusawa, Yoshiya; Matsumoto, Yoshitaka; Takai, Nobuhiko; Hirayama, Ryoichi; Watanabe, Masahiko; Scholz, Michael; Elsaesser, Thilo; Peschke, Peter

    2009-01-01

    Purpose: To compare the biological effectiveness of 290 MeV/amu carbon-ion beams in Chiba, Japan and in Darmstadt, Germany, given that different methods for beam delivery are used for each. Methods and Materials: Murine small intestine and human salivary gland tumor (HSG) cells exponentially growing in vitro were irradiated with 6-cm width of spread-out Bragg peaks (SOBPs) adjusted to achieve nearly identical beam depth-dose profiles at the Heavy-Ion Medical Accelerator in Chiba, and the SchwerIonen Synchrotron in Darmstadt. Cell kill efficiencies of carbon ions were measured by colony formation for HSG cells and jejunum crypts survival in mice. Cobalt-60 γ rays were used as the reference radiation. Isoeffective doses at given survivals were used for relative biological effectiveness (RBE) calculations and interinstitutional comparisons. Results: Isoeffective D 10 doses (mean ± standard deviation) of HSG cells ranged from 2.37 ± 0.14 Gy to 3.47 ± 0.19 Gy for Chiba and from 2.31 ± 0.11 Gy to 3.66 ± 0.17 Gy for Darmstadt. Isoeffective D 10 doses of gut crypts after single doses ranged from 8.25 ± 0.17 Gy to 10.32 ± 0.14 Gy for Chiba and from 8.27 ± 0.10 Gy to 10.27 ± 0.27 Gy for Darmstadt, whereas isoeffective D 30 doses after three fractionated doses were 9.89 ± 0.17 Gy through 13.70 ± 0.54 Gy and 10.14 ± 0.20 Gy through 13.30 ± 0.41 Gy for Chiba and Darmstadt, respectively. Overall difference of RBE between the two facilities was 0-5% or 3-7% for gut crypt survival or HSG cell kill, respectively. Conclusion: The carbon-ion beams at the National Institute of Radiological Sciences in Chiba, Japan and the Gesellschaft fuer Schwerionenforschung in Darmstadt, Germany are biologically identical after single and daily fractionated irradiation.

  10. Assessment of adhesive setting time in reinforced concrete beams strengthened with carbon fibre reinforced polymer laminates

    International Nuclear Information System (INIS)

    Fayyadh, Moatasem M.; Abdul Razak, H.

    2012-01-01

    Highlights: ► This study investigated the effect of adhesive setting time on the modal parameters. ► Modal parameters recommend the 18th day as the maturity age of the adhesive. ► Static data recommend 7th day as the maturity age of the adhesive. ► Setting time affects the modal parameters as tool for assessment repaired structures. ► Carrying the modal parameters after 1st day results in 55% loss of the actual improvement. -- Abstract: The strengthened effectiveness and the performance capacity of repaired Reinforced Concrete (RC) structures with Carbon Fibre Reinforced Polymer (CFRP) sheets is dependent on the properties of the adhesive interface layer. Adhesive material requires a specific setting time to achieve the maximum design capacity. Adhesive producer provides technical data which demonstrates the increase with time of the capacity, up to the maximum. The aim of this study is to investigate the effect of the adhesive setting time on the modal parameters as an indication of the effectiveness of CFRP on repaired RC beams. Firstly, datum modal parameters were determined on the undamaged beam and subsequently the parameters were obtained when damaged was induced on the RC beam by application of load until the appearance of the first crack. Finally, the RC beam is repaired with externally bonded CFRP sheets, and modal parameters are once again applied after 0.5, 1, 2, 3, 5, 8, 11, 15 and 18 days. The comparison is made with the data based on half day results in order to monitor the change in the modal parameters corresponding to the adhesive setting time. The modal parameters where used as indicators for the effectiveness of CFRP are affected by the adhesive time as shown in this study. Results are compared with the adhesive technical data provided by the adhesive producer.

  11. The synthesis of no-carrier-added [11C]urea from [11C]carbon dioxide and application to [11C]uracil synthesis

    International Nuclear Information System (INIS)

    Chakraborty, P.K.; Mangner, T.J.; Chugani, H.T.

    1997-01-01

    No-carrier-added [ 11 C]urea has been synthesized by bubbling cyclotron-produced [ 11 C]-carbon dioxide directly into a tetrahydrofuran solution of lithium bis(trimethylsilyl)amide, followed by hydrolysis of the C-11 labeled adduct with aqueous ammonium chloride. Using this simple, one-pot method, [ 11 C]urea was produced in 55-70% radiochemical yield (decay-corrected) in 16 min following end-of-bombardment (or in 10 min following the introduction of the [ 11 C]carbon dioxide. The [ 11 C]urea thus produced was converted to [ 11 C]uracil (carrier-added) in 40-75% decay-corrected radiochemical yield by condensation with diethyl malate in presence of fuming sulfuric acid. (author)

  12. Bending of metal-filled carbon nanotube under electron beam irradiation

    Directory of Open Access Journals (Sweden)

    Abha Misra

    2012-03-01

    Full Text Available Electron beam irradiation induced, bending of Iron filled, multiwalled carbon nanotubes is reported. Bending of both the carbon nanotube and the Iron contained within the core was achieved using two approaches with the aid of a high resolution electron microscope (HRTEM. In the first approach, bending of the nanotube structure results in response to the irradiation of a pristine kink defect site, while in the second approach, disordered sites induce bending by focusing the electron beam on the graphite walls. The HRTEM based in situ observations demonstrate the potential for using electron beam irradiation to investigate and manipulate the physical properties of confined nanoscale structures.

  13. Quantitative evaluation of potential irradiation geometries for carbon-ion beam grid therapy.

    Science.gov (United States)

    Tsubouchi, Toshiro; Henry, Thomas; Ureba, Ana; Valdman, Alexander; Bassler, Niels; Siegbahn, Albert

    2018-03-01

    Radiotherapy using grids containing cm-wide beam elements has been carried out sporadically for more than a century. During the past two decades, preclinical research on radiotherapy with grids containing small beam elements, 25 μm-0.7 mm wide, has been performed. Grid therapy with larger beam elements is technically easier to implement, but the normal tissue tolerance to the treatment is decreasing. In this work, a new approach in grid therapy, based on irradiations with grids containing narrow carbon-ion beam elements was evaluated dosimetrically. The aim formulated for the suggested treatment was to obtain a uniform target dose combined with well-defined grids in the irradiated normal tissue. The gain, obtained by crossfiring the carbon-ion beam grids over a simulated target volume, was quantitatively evaluated. The dose distributions produced by narrow rectangular carbon-ion beams in a water phantom were simulated with the PHITS Monte Carlo code. The beam-element height was set to 2.0 cm in the simulations, while the widths varied from 0.5 to 10.0 mm. A spread-out Bragg peak (SOBP) was then created for each beam element in the grid, to cover the target volume with dose in the depth direction. The dose distributions produced by the beam-grid irradiations were thereafter constructed by adding the dose profiles simulated for single beam elements. The variation of the valley-to-peak dose ratio (VPDR) with depth in water was thereafter evaluated. The separation of the beam elements inside the grids were determined for different irradiation geometries with a selection criterion. The simulated carbon-ion beams remained narrow down to the depths of the Bragg peaks. With the formulated selection criterion, a beam-element separation which was close to the beam-element width was found optimal for grids containing 3.0-mm-wide beam elements, while a separation which was considerably larger than the beam-element width was found advantageous for grids containing 0.5-mm

  14. Multi-pulsed intense electron beam emission from velvet, carbon fibers, carbon nano-tubes and dispenser cathodes

    International Nuclear Information System (INIS)

    Xia Liansheng; Yang Anmin; Chen Yi; Zhang Huang; Liu Xingguang; Li Jin; Jiang Xiaoguo; Zhang Kaizhi; Shi Jinshui; Deng Jianjun; Zhang Linwen

    2010-01-01

    The experimental results of studies of four kinds of cathode emitting intense electron beams are demonstrated under multi-pulsed mode based on an experimental setup including two multi-pulse high voltage sources. The tested cathodes include velvet, carbon fibers, carbon nano-tubes (CNTs) and dispenser cathodes. The results indicate that all four are able to emit multi-pulsed beams. For velvet, carbon fiber and CNTs, the electron induced cathode plasma emission may be the main process and this means that there are differences in beam parameters from pulse to pulse. For dispenser cathodes tested in the experiment, although there is a little difference from pulse to pulse for some reason, thermal-electric field emission may be the main process. (authors)

  15. Determination of biological transport of oxygen-15 and carbon-11 generated in rats

    International Nuclear Information System (INIS)

    Archambeau, B.; Bennett, G.W.; Archambeau, J.O.

    1976-02-01

    The distribution of induced 15 O and 11 C activity in live and dead rats was determined following local irradiation with a 32 MeV proton beam. Results indicate that rapid biological redistribution of some of the induced activity occurs within a minute following irradiation. Sufficient activity remains, bound in the intracellular water, to define the proton beam in tissue. Thus, mapping of the induced 15 O activity proves to be a valid means of beam localization

  16. Enhanced electromagnetic properties of nickel nanoparticiles dispersed carbon fiber via electron beam irradiation

    International Nuclear Information System (INIS)

    Lee, Yeong Ju; Kim, Hyun Bin; Lee, Seung Jun; Kang, Phil Hyun

    2015-01-01

    Carbon fiber has received much attention owing to its properties, including a large surface-to-volume ratio, chemical and thermal stability, high thermal and electrical conductivity, and high mechanical strengths. In particular, magnetic nanopowder dispersed carbon fiber has been attractive in technological applications such as the electrochemical capacitor and electromagnetic wave shielding. In this study, the nickel-oxide-nanoparticle dispersed polyacrylonitrile (PAN) fibers were prepared through an electrospinning method. Electron beam irradiation was carried out with a 2.5 MeV beam energy to stabilize the materials. The samples were then heat treated for stabilization and carbonization. The nanofiber surface was analyzed using a field emission scanning electron microscope (FE-SEM). The crystal structures of the carbon matrix and nickel nanopowders were analysed using X-ray diffraction (XRD). In addition, the magnetic and electrical properties were analyzed using a vibrating sample magnetometer (VSM) and 4 point probe. As the irradiation dose increases, the density of the carbon fiber was increased. In addition, the electrical properties of the carbon fiber improved through electron beam irradiation. This is because the amorphous region of the carbon fiber decreases. This electron beam effect of PAN fibers containing nickel nanoparticles confirmed their potential as a high performance carbon material for various applications

  17. Large flexibility of high aspect ratio carbon nanostructures fabricated by electron-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Beard, J D; Gordeev, S N, E-mail: jdb28@bath.ac.uk [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)

    2010-11-26

    The mechanical properties of free-standing electron beam deposited amorphous carbon structures have been studied using atomic force microscopy. The fabricated carbon blades are found to be extraordinarily flexible, capable of undergoing vertical deflection up to {approx} 75% of their total length without inelastic deformation. The elastic bending modulus of these structures was calculated to be 28 {+-} 10 GPa.

  18. Enhanced electromagnetic properties of nickel nanoparticiles dispersed carbon fiber via electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yeong Ju; Kim, Hyun Bin; Lee, Seung Jun; Kang, Phil Hyun [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2015-02-15

    Carbon fiber has received much attention owing to its properties, including a large surface-to-volume ratio, chemical and thermal stability, high thermal and electrical conductivity, and high mechanical strengths. In particular, magnetic nanopowder dispersed carbon fiber has been attractive in technological applications such as the electrochemical capacitor and electromagnetic wave shielding. In this study, the nickel-oxide-nanoparticle dispersed polyacrylonitrile (PAN) fibers were prepared through an electrospinning method. Electron beam irradiation was carried out with a 2.5 MeV beam energy to stabilize the materials. The samples were then heat treated for stabilization and carbonization. The nanofiber surface was analyzed using a field emission scanning electron microscope (FE-SEM). The crystal structures of the carbon matrix and nickel nanopowders were analysed using X-ray diffraction (XRD). In addition, the magnetic and electrical properties were analyzed using a vibrating sample magnetometer (VSM) and 4 point probe. As the irradiation dose increases, the density of the carbon fiber was increased. In addition, the electrical properties of the carbon fiber improved through electron beam irradiation. This is because the amorphous region of the carbon fiber decreases. This electron beam effect of PAN fibers containing nickel nanoparticles confirmed their potential as a high performance carbon material for various applications.

  19. Modeling the biophysical effects in a carbon beam delivery line by using Monte Carlo simulations

    Science.gov (United States)

    Cho, Ilsung; Yoo, SeungHoon; Cho, Sungho; Kim, Eun Ho; Song, Yongkeun; Shin, Jae-ik; Jung, Won-Gyun

    2016-09-01

    The Relative biological effectiveness (RBE) plays an important role in designing a uniform dose response for ion-beam therapy. In this study, the biological effectiveness of a carbon-ion beam delivery system was investigated using Monte Carlo simulations. A carbon-ion beam delivery line was designed for the Korea Heavy Ion Medical Accelerator (KHIMA) project. The GEANT4 simulation tool kit was used to simulate carbon-ion beam transport into media. An incident energy carbon-ion beam with energy in the range between 220 MeV/u and 290 MeV/u was chosen to generate secondary particles. The microdosimetric-kinetic (MK) model was applied to describe the RBE of 10% survival in human salivary-gland (HSG) cells. The RBE weighted dose was estimated as a function of the penetration depth in the water phantom along the incident beam's direction. A biologically photon-equivalent Spread Out Bragg Peak (SOBP) was designed using the RBE-weighted absorbed dose. Finally, the RBE of mixed beams was predicted as a function of the depth in the water phantom.

  20. Experimental analysis of reinforced concrete beams strengthened in bending with carbon fiber reinforced polymer

    Directory of Open Access Journals (Sweden)

    M. M. VIEIRA

    Full Text Available The use of carbon fiber reinforced polymer (CFRP has been widely used for the reinforcement of concrete structures due to its practicality and versatility in application, low weight, high tensile strength and corrosion resistance. Some construction companies use CFRP in flexural strengthening of reinforced concrete beams, but without anchor systems. Therefore, the aim of this study is analyze, through an experimental program, the structural behavior of reinforced concrete beams flexural strengthened by CFRP without anchor fibers, varying steel reinforcement and the amount of carbon fibers reinforcement layers. Thus, two groups of reinforced concrete beams were produced with the same geometric feature but with different steel reinforcement. Each group had five beams: one that is not reinforced with CFRP (reference and other reinforced with two, three, four and five layers of carbon fibers. Beams were designed using a computational routine developed in MAPLE software and subsequently tested in 4-point points flexural test up to collapse. Experimental tests have confirmed the effectiveness of the reinforcement, ratifying that beams collapse at higher loads and lower deformation as the amount of fibers in the reinforcing layers increased. However, the increase in the number of layers did not provide a significant increase in the performance of strengthened beams, indicating that it was not possible to take full advantage of strengthening applied due to the occurrence of premature failure mode in the strengthened beams for pullout of the cover that could have been avoided through the use of a suitable anchoring system for CFRP.

  1. Fabrication of carbon layer coated FE-nanoparticles using an electron beam irradiation

    Science.gov (United States)

    Kim, Hyun Bin; Jeun, Joon Pyo; Kang, Phil Hyun; Oh, Seung-Hwan

    2016-01-01

    A novel synthesis of carbon encapsulated Fe nanoparticles was developed in this study. Fe chloride (III) and polyacrylonitrile (PAN) were used as precursors. The crosslinking of PAN molecules and the nucleation of Fe nanoparticles were controlled by the electron beam irradiation dose. Stabilization and carbonization processes were carried out using a vacuum furnace at 275 °C and 1000 °C, respectively. Micro structures were evaluated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Fe nanoparticles were formed with diameters of 100 nm, and the Fe nanoparticles were encapsulated by carbon layers. As the electron beam irradiation dose increased, it was observed that the particle sizes decreased.

  2. Stress corrosion cracking tests on electron beam welded carbon steel specimens in carbonate-bicarbonate solution

    International Nuclear Information System (INIS)

    Parkins, R.N.

    1985-04-01

    Stress corrosion cracking tests have been performed on tapered carbon steel test pieces containing electron beam welds with a view to defining susceptibility to such cracking in a carbonate-bicarbonate solution at 90 C and an appropriate electrode potential. The tests involved applying cyclic loads to the specimens and it is shown that the threshold stress for cracking reduces linearly with increase in the magnitude of the cyclic load component. Extrapolation of these trends to zero fluctuating stress indicates static load threshold stresses in the vicinity of the yield stress (i.e. about 300 N/mm 2 for parent plate without a weld, 400 N/mm 2 for specimens with welds on one side only and 600 N/mm 2 for specimens having welds penetrating through the thickness of the specimen). The averages of the maximum crack velocities observed were least for parent plate material and greatest for weld metal, the former being essentially intergranular in morphology and the latter mostly transgranular, with heat affected zone material being intermediate between these extremes. (author)

  3. Inhibition of potential lethal damage repair and related gene expression after carbon-ion beam irradiation to human lung cancer grown in nude mice

    International Nuclear Information System (INIS)

    Yashiro, Tomoyasu; Fujisawa, Takehiko; Koyama-Saegusa, Kumiko; Imai, Takashi; Miyamoto, Tadaaki

    2007-01-01

    Using cultured and nude mouse tumor cells (IA) derived from a human lung cancer, we previously demonstrated their radiosensitivity by focusing attention on the dynamics of tumor clonogens and the early and rapid survival recovery (potential lethal damage repair: PLD repair) occurring after X-ray irradiation. To the authors' knowledge, this is the first study demonstrating gene expression in association with PLD repair after carbon-ion beam or X-ray irradiation to cancer cells. In this study we tried to detect the mechanism of DNA damage and repair of the clonogens after X-ray or carbon-ion beam irradiation. At first, colony assay method was performed after irradiation of 12 Gy of X-ray or 5 Gy of carbon-ion beam to compare the time dependent cell survival of the IA cells after each irradiation pass. Second, to search the genes causing PLD repair after irradiation of X-ray or carbon-ion beam, we evaluated gene expressions by using semi-quantitative RT-PCR with the selected 34 genes reportedly related to DNA repair. The intervals from the irradiation were 0, 6, 12 and 24 hr for colony assay method, and 0, 3, 18 hr for RT-PCR method. From the result of survival assays, significant PLD repair was not observed in carbon-ion beam as compared to X-ray irradiation. The results of RT-PCR were as follows. The gene showing significantly higher expressions after X-ray irradiation than after carbon-ion beam irradiation was PCNA. The genes showing significantly lower expressions after X-ray irradiation rather than after carbon-ion beam irradiation were RAD50, BRCA1, MRE11A, XRCC3, CHEK1, MLH1, CCNB1, CCNB2 and LIG4. We conclude that PCNA could be a likely candidate gene for PLD repair. (author)

  4. The preparation and application of carbon-11 nuclide and its PET imaging agent

    International Nuclear Information System (INIS)

    Wang Mingfang

    2002-01-01

    Carbon-11 is a valuable positron nuclide, for it can be used to replace carbon atom at specific position inside the organic molecules and not change the molecular biochemistry character. Carbon-11 has wide application in the labeling of amino acids, fatty acids, receptor-ligand and neurotransmitter molecular etc, which are used for detecting the blood flow, metabolism, the synthesis of protein and the neurotransmitter function in brain by PET imaging. It is very important in basic science and clinical research to understand and master the preparation of carbon-11 and its labeled compounds

  5. 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

    2010-05-07

    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.

  6. Engineering catalytic activity via ion beam bombardment of catalyst supports for vertically aligned carbon nanotube growth

    Science.gov (United States)

    Islam, A. E.; Nikolaev, P.; Amama, P. B.; Zakharov, D.; Sargent, G.; Saber, S.; Huffman, D.; Erford, M.; Semiatin, S. L.; Stach, E. A.; Maruyama, B.

    2015-09-01

    Carbon nanotube growth depends on the catalytic activity of metal nanoparticles on alumina or silica supports. The control on catalytic activity is generally achieved by variations in water concentration, carbon feed, and sample placement on a few types of alumina or silica catalyst supports obtained via thin film deposition. We have recently expanded the choice of catalyst supports by engineering inactive substrates like c-cut sapphire via ion beam bombardment. The deterministic control on the structure and chemistry of catalyst supports obtained by tuning the degree of beam-induced damage have enabled better regulation of the activity of Fe catalysts only in the ion beam bombarded areas and hence enabled controllable super growth of carbon nanotubes. A wide range of surface characterization techniques were used to monitor the catalytically active surface engineered via ion beam bombardment. The proposed method offers a versatile way to control carbon nanotube growth in patterned areas and also enhances the current understanding of the growth process. With the right choice of water concentration, carbon feed and sample placement, engineered catalyst supports may extend the carbon nanotube growth yield to a level that is even higher than the ones reported here, and thus offers promising applications of carbon nanotubes in electronics, heat exchanger, and energy storage.

  7. Effect of carbon on ion beam mixing of Fe-Ti bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, J.P.; Nastasi, M.; Lappalainen, R.; Sickafus, K. (Los Alamos National Lab., NM (USA); Helsinki Univ. (Finland). Dept. of Physics; Los Alamos National Lab., NM (USA))

    1989-01-01

    The influence of implanted carbon on ion beam mixing of a Fe-Ti system was investigated. Carbon was introduced into bilayer samples by implanting {sup 13}C isotopes. The implantation energies were selected to set the mean range of carbon ions in either the iron or titanium layer. The effect of implanted carbon on 400 keV Ar ion mixing in the temperature range from 0 to 300{degree}C was studied using Rutherford backscattering spectroscopy at the energy of 5 MeV. Changes in carbon concentration profiles were probed utilizing the resonance of the nuclear reaction {sup 13}C(p,{gamma}){sup 14}N at the proton energy of 1.748 MeV. The measurements revealed that mixing was not affected by carbon implanted into the titanium layer. However, carbon in the iron layer remarkably retarded mixing at all temperatures investigated. Significant changes in carbon depth distributions were observed only when the sample with implanted carbon in the iron layer was mixed at 300{degree}C. These results are explained in terms of the enhanced mobility of carbon in an evaporated iron film which allows segregation to the interface. At low temperatures, however, vacancy-carbon interaction in iron may have a contribution to the retarded ion beam mixing. 19 refs., 3 figs.

  8. Precipitation as driver of carbon fluxes in 11 African ecosystems

    NARCIS (Netherlands)

    Merbold, L.; Ardo, J.; Arneth, A.; Scholes, R.J.; Nouvellon, Y.; Grandcourt, de A.; Archibald, S.; Bonnefonds, J.M.; Boulain, N.; Bruemmer, C.; Brueggemann, N.; Cappelaere, B.; Ceschia, E.; El-Khidir, H.A.M.; El-Tahir, B.A.; Falk, U.; Lloyd, J.; Kergoat, L.; Dantec, Le V.; Mougin, E.; Muchinda, M.; Mukelabai, M.M.; Ramier, D.; Roupsard, O.; Timouk, F.; Veenendaal, E.M.; Kutsch, W.L.

    2009-01-01

    This study reports carbon and water fluxes between the land surface and atmosphere in eleven different ecosystems types in Sub-Saharan Africa, as measured using eddy covariance (EC) technology in the first two years of the CarboAfrica network operation. The ecosystems for which data were available

  9. BEAM DYNAMICS STUDIES FOR A COMPACT CARBON ION LINAC FOR THERAPY

    Energy Technology Data Exchange (ETDEWEB)

    Plastun, A.; Mustapha, B.; Nassiri, A.; Ostroumov, P.

    2016-05-01

    Feasibility of an Advanced Compact Carbon Ion Linac (ACCIL) for hadron therapy is being studied at Argonne National Laboratory in collaboration with RadiaBeam Technologies. The 45-meter long linac is designed to deliver 109 carbon ions per second with variable energy from 45 MeV/u to 450 MeV/u. S-band structure provides the acceleration in this range. The carbon beam energy can be adjusted from pulse to pulse, making 3D tumor scanning straightforward and fast. Front end accelerating structures such as RFQ, DTL and coupled DTL are designed to operate at lower frequencies. The design of the linac was accompanied with extensive end-to-end beam dynamics studies which are presented in this paper.

  10. Characterization of electron beam evaporated carbon films and compound formation on titanium and silicon

    International Nuclear Information System (INIS)

    Luthin, J.; Linsmeier, C.

    2001-01-01

    The formation of carbon-based mixed materials is unavoidable on the plasma-facing components (e.g. first wall and divertor) of fusion devices when carbon is used together with other materials. On the surfaces of these components very different conditions with respect to particle and energy impact occur. To predict the mixed material formation under these conditions the precise knowledge of the fundamental mechanisms governing these interactions is essential. In this paper we present the results of carbon interaction with titanium and silicon, as model substances for metallic and covalent carbides, during thermal treatment. To perform basic studies of the reactions of carbon with different elements, thin carbon films are produced by electron beam evaporation on the different substrates under UHV conditions. All measurements for chemical analysis are performed using X-ray photoelectron spectroscopy (XPS). We discuss first the properties of the deposited carbon films. The carbon films are characterized on inert gold surfaces and are compared to bulk graphite. Annealing of the carbon films up to 970 K leads to a transition from a disordered carbon network into a graphitic structure. Preparation of carbon films at room temperature on titanium or silicon leads to a limited carbide formation at the carbon/substrate interface. Carbon deposited in excess of several monolayers is present in elementary form. Annealing of the samples leads to complete carbidization consuming the available carbon in both cases. Titanium reacts to TiC and additional substoichiometric carbide, silicon forms SiC with exact stoichiometry. (orig.)

  11. Effective source size, radial, angular and energy spread of therapeutic 11C positron emitter beams produced by 12C fragmentation

    Science.gov (United States)

    Lazzeroni, Marta; Brahme, Anders

    2014-02-01

    The use of positron emitter light ion beams in combination with PET (Positron Emission Tomography) and PET-CT (Computed Tomography) imaging could significantly improve treatment verification and dose delivery imaging during radiation therapy. The present study is dedicated to the analysis of the beam quality in terms of the effective source size, as well as radial, angular and energy spread of the 11C ion beam produced by projectile fragmentation of a primary point monodirectional and monoenergetic 12C ion beam in a dedicated range shifter of different materials. This study was performed combining analytical methods describing the transport of particles in matter and the Monte Carlo code SHIELD-HIT+. A high brilliance and production yield of 11C fragments with a small effective source size and emittance is best achieved with a decelerator made of two media: a first liquid hydrogen section of about 20 cm followed by a hydrogen rich section of variable length. The calculated intensity of the produced 11C ion beam ranges from about 5% to 8% of the primary 12C beam intensity depending on the exit energy and the acceptance of the beam transport system. The angular spread is lower than 1 degree for all the materials studied, but the brilliance of the beam is the highest with the proposed mixed decelerator.

  12. Phase aberrations and beam cleanup techniques in carbon-dioxide laser fusion systems

    International Nuclear Information System (INIS)

    Viswanathan, V.K.

    1981-01-01

    This paper describes the various carbon dioxide laser fusion systems at Los Alamos from the point of view of an optical designer. The types of phase aberrations present in these systems, as well as the beam cleanup techniques that can be used to improve the beam optical quality, are discussed. As this is a review article, some previously published results are also used where relevant

  13. Research on carbon fiber–reinforced plastic bumper beam subjected to low-velocity frontal impact

    OpenAIRE

    Yefa Hu; Can Liu; Jinguang Zhang; Guoping Ding; Qiong Wu

    2015-01-01

    Lightweight and safety performance of automobiles are two important factors for automobile designs. In this article, a research on lightweight and crashworthiness of automotive bumper has been conducted. The carbon fiber–reinforced plastic bumper beam is considered to replace the traditional high-strength steel one. The low-velocity impact finite element simulations for the above two bumper beams are performed via LS-DYNA. Furthermore, the energy absorption capabilities and dynamic response c...

  14. Characterisation of a ultra-miniature counter for microdosimetric measurements in a therapeutic 400 MeV/A carbon beam

    International Nuclear Information System (INIS)

    Endo, S.; Takada, M.; Ishikawa, M.; Hoshi, M.; Uehara, S.; Yamaguchi, H.; Kanai, T.; Matsufji, N.; Shizuma, K.; Onizuka, Y.

    2002-01-01

    Single event spectra of a clinical carbon beam have been measured by an ultra-miniature tissue-equivalent proportional counter (UMC). In order to cover the energy range of the Bragg peak, the incident energy of the carbon beam was degraded by aluminium plates. Single event spectra for carbon-events incident to the UMC were analysed and selected at several carbon energies using thin scintillation counters. It was found that the dose weighted lineal energy distributions have a doublet peak structure due to incident carbon beam and fragment contributions. (author)

  15. Synthesis of carbon-11 labelled (R)-carnitine

    International Nuclear Information System (INIS)

    Holschbach, M.; Hamkens, W.; Roden, W.; Feinendegen, L.E.

    1991-01-01

    A route to 11 C-labelled (R)-carnitine, based on the methylation of the dimethyl derivative is described. Furthermore, a five-step synthesis for the enantiomerically pure precursor is outlined. (author)

  16. Research on carbon fiber–reinforced plastic bumper beam subjected to low-velocity frontal impact

    Directory of Open Access Journals (Sweden)

    Yefa Hu

    2015-06-01

    Full Text Available Lightweight and safety performance of automobiles are two important factors for automobile designs. In this article, a research on lightweight and crashworthiness of automotive bumper has been conducted. The carbon fiber–reinforced plastic bumper beam is considered to replace the traditional high-strength steel one. The low-velocity impact finite element simulations for the above two bumper beams are performed via LS-DYNA. Furthermore, the energy absorption capabilities and dynamic response characteristics of the carbon fiber–reinforced plastic bumper beam are investigated and compared with the steel one. The results show that the carbon fiber–reinforced plastic bumper beam is of the better energy absorption capabilities and dynamic response characteristics than those of the steel one; the weight has decreased remarkably close to 50%. Meanwhile, the effect of lay-up and wall thickness on the crashworthiness of the carbon fiber–reinforced plastic bumper beam under low-velocity impact is also studied in this article to select appropriate design schemes.

  17. Noninvasive measurement of lung carbon-11-serotonin extraction in man

    International Nuclear Information System (INIS)

    Coates, G.; Firnau, G.; Meyer, G.J.; Gratz, K.F.

    1991-01-01

    The fraction of serotonin extracted on a single passage through the lungs is being used as an early indicator of lung endothelial damage but the existing techniques require multiple arterial blood samples. We have developed a noninvasive technique to measure lung serotonin uptake in man. We utilized the double indicator diffusion principle, a positron camera, 11 C-serotonin as the substrate, and 11 CO-erythrocytes as the vascular marker. From regions of interest around each lung, we recorded time-activity curves in 0.5-sec frames for 30 sec after a bolus injection of first the vascular marker 11 CO-erythrocytes and 10 min later 11 C-serotonin. A second uptake measurement was made after imipramine 25-35 mg was infused intravenously. In three normal volunteers, the single-pass uptake of 11 C-serotonin was 63.9% +/- 3.6%. This decreased in all subjects to a mean of 53.6% +/- 1.4% after imipramine. The rate of lung washout of 11 C was also significantly prolonged after imipramine. This noninvasive technique can be used to measure lung serotonin uptake to detect early changes in a variety of conditions that alter the integrity of the pulmonary endothelium

  18. Precipitation as driver of carbon fluxes in 11 African ecosystems

    Directory of Open Access Journals (Sweden)

    L. Merbold

    2009-06-01

    Full Text Available This study reports carbon and water fluxes between the land surface and atmosphere in eleven different ecosystems types in Sub-Saharan Africa, as measured using eddy covariance (EC technology in the first two years of the CarboAfrica network operation. The ecosystems for which data were available ranged in mean annual rainfall from 320 mm (Sudan to 1150 mm (Republic of Congo and include a spectrum of vegetation types (or land cover (open savannas, woodlands, croplands and grasslands. Given the shortness of the record, the EC data were analysed across the network rather than longitudinally at sites, in order to understand the driving factors for ecosystem respiration and carbon assimilation, and to reveal the different water use strategies in these highly seasonal environments.

    Values for maximum net carbon assimilation rates (photosynthesis ranged from −12.5 μmol CO2 m−2 s−1 in a dry, open Millet cropland (C4-plants up to −48 μmol CO2 m−2 s−1 for a tropical moist grassland. Maximum carbon assimilation rates were highly correlated with mean annual rainfall (r2=0.74. Maximum photosynthetic uptake rates (Fpmax were positively related to satellite-derived fAPAR. Ecosystem respiration was dependent on temperature at all sites, and was additionally dependent on soil water content at sites receiving less than 1000 mm of rain per year. All included ecosystems dominated by C3-plants, showed a strong decrease in 30-min assimilation rates with increasing water vapour pressure deficit above 2.0 kPa.

  19. Analysis of the strength and stiffness of timber beams reinforced with carbon fiber and glass fiber

    Directory of Open Access Journals (Sweden)

    Juliano Fiorelli

    2003-06-01

    Full Text Available An experimental analysis of pinewood beams (Pinus caribea var hondurensis reinforced with glass and/or carbon fibers is discussed. The theoretical model employed to calculate the beam's bending strength takes into account the timber's ultimate limit states of tensile strength and failure by compression, considering a model of fragile elastic tension and plastic elastic compression. The validity of the theoretical model is confirmed by a comparison of the theoretical and experimental results, while the efficiency of the fiber reinforcement is corroborated by the increased strength and stiffness of the reinforced timber beams.

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

    CERN Document Server

    Shornikov, A.

    2016-01-01

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

  1. Role of lattice structure and low temperature resistivity in fast-electron-beam filamentation in carbon

    International Nuclear Information System (INIS)

    Dance, R J; Butler, N M H; Gray, R J; MacLellan, D A; Rusby, D R; Xu, H; Neely, D; McKenna, P; Scott, G G; Robinson, A P L; Zielbauer, B; Bagnoud, V; Desjarlais, M P

    2016-01-01

    The influence of low temperature (eV to tens-of-eV) electrical resistivity on the onset of the filamentation instability in fast-electron transport is investigated in targets comprising of layers of ordered (diamond) and disordered (vitreous) carbon. It is shown experimentally and numerically that the thickness of the disordered carbon layer influences the degree of filamentation of the fast-electron beam. Strong filamentation is produced if the thickness is of the order of 60 μm or greater, for an electron distribution driven by a sub-picosecond, mid-10 20 Wcm −2 laser pulse. It is shown that the position of the vitreous carbon layer relative to the fast-electron source (where the beam current density and background temperature are highest) does not have a strong effect because the resistive filamentation growth rate is high in disordered carbon over a wide range of temperatures up to the Spitzer regime. (paper)

  2. SU-F-BRE-11: Neutron Measurements Around the Varian TrueBeam Linac

    Energy Technology Data Exchange (ETDEWEB)

    Maglieri, R; Seuntjens, J; Kildea, J [McGill University, Montreal, QC (Canada); Liang, L; DeBlois, F [Jewish General Hospital, Montreal, QC (Canada); Evans, M [Montreal General Hospital, Montreal, QC (Canada); Licea, A [Canadian Nuclear Safety Comission, Ottawa, Ontario (Canada); Dubeau, J; Witharana, S [Detec, Gatineau, QC (Canada)

    2014-06-15

    Purpose: With the emergence of flattening filter free (FFF) photon beams, several authors have noted many advantages to their use. One such advantage is the decrease in neutron production by photonuclear reactions in the linac head. In the present work we investigate the reduction in neutrons from a Varian TrueBeam linac using the Nested Neutron Spectrometer (NNS, Detec). The neutron spectrum, total fluence and source strength were measured and compared for 10 MV with and without flattening filter and the effect of moderation by the room and maze was studied for the 15 MV beam. Methods: The NNS, similar to traditional Bonner sphere detectors but operated in current mode, was used to measure the neutron fluence and spectrum. The NNS was validated for use in high dose rate environments using Monte Carlo simulations and calibrated at NIST and NRC Canada. Measurements were performed at several positions within the treatment room and maze with the linac jaws closed to maximize neutron production. Results: The measurements showed a total fluence reduction between 35-40% in the room and maze when the flattening filter was removed. The neutron source strength Qn was calculated from in-room fluence measurements and was found to be 0.042 × 10{sup 2} n/Gy, 0.026 × 10{sup 2} n/Gy and 0.59 × 101{sup 2} n/Gy for the 10 MV, the 10 MV FFF and 15 MV beams, respectively. We measured ambient equivalent doses of 11 mSv/hr, 7 mSv/hr and 218 mSv/hr for the 10 MV, 10 MV FFF and 15 MV by the head. Conclusion: Our measurements revealed a decrease in total fluence, neutron source strength and equivalent dose of approximately 35-40% across the treatment room for the FFF compared to FF modes. This demonstrates, as expected, that the flattening filter is a major component of the neutron production for the TrueBeam. The authors greatly acknowledge support form the Canadian Nuclear Commission and the Natural Sciences and Engineering Research Council of Canada through the CREATE program. Co

  3. Production and beam annealing of damage in carbon implanted silicon

    International Nuclear Information System (INIS)

    Kool, W.H.; Roosendaal, H.E.; Wiggers, L.W.; Saris, F.W.

    1978-01-01

    The annealing of damage introduced by 70 keV C implantation of Si is studied for impact of H + and He + beams in the energy interval 30 to 200 keV. For a good description of the annealing behaviour it is necessary to account for the damage introduction which occurs simultaneously. It turns out that the initial damage annealing rate is proportional to the amount of damage. The proportionality constant is related to a quantity introduced in an earlier paper in order to describe saturation effects in the damage production after H + or He + impact in unimplanted Si. This indicates that the same mechanism governs both processes: beam induced damage annealing and saturation of the damage introduction. (author)

  4. Three-dimensional ultrashort optical Airy beams in an inhomogeneous medium with carbon nanotubes

    Science.gov (United States)

    Zhukov, Alexander V.; Bouffanais, Roland; Belonenko, Mikhail B.; Dvuzhilov, Ilya S.

    2017-03-01

    In this Letter, we consider the problem of the dynamics of propagation of three-dimensional optical pulses (a.k.a. light bullets) with an Airy profile through a heterogeneous environment of carbon nanotubes. We show numerically that such beams exhibit sustained and stable propagation. Moreover, we demonstrate that by varying the density modulation period of the carbon nanotubes one can indirectly control the pulse velocity, which is a particularly valuable feature for the design and manufacturing of novel pulse delay devices.

  5. Ion beam trajectory simulation of carbon isotopes in cyclotron DECY-13

    International Nuclear Information System (INIS)

    Pramudita Anggraita

    2014-01-01

    A simulation on the ion beam trajectories of various carbon isotopes "1"2C, "1"3C, and "1"4C in DECY-13 cyclotron has been carried out using Scilab 5.4.1 software. Calculations in the simulation were carried out in 3 dimensions. The simulation shows trajectory separations, which provide possibility for "1"4C measurement such as in carbon dating at accelerating voltage frequency of about 72 MHz. (author)

  6. Reprint of: Negative carbon cluster ion beams: New evidence for the special nature of C60

    Science.gov (United States)

    Liu, Y.; O'brien, S. C.; Zhang, Q.; Heath, J. R.; Tittel, F. K.; Curl, R. F.; Kroto, H. W.; Smalley, R. E.

    2013-12-01

    Cold carbon cluster negative ions are formed by supersonic expansion of a plasma created at the nozzle of a supersonic cluster beam source by an excimer laser pulse. The observed distribution of mass peaks for the Cn- ions for n > 40 demonstrates that the evidence previously given for the special stability of neutral C60 and the existence of spheroidal carbon shells cannot be an artifact of the ionization conditions.

  7. Synthesis of [(11)C]Am80 via Novel Pd(0)-Mediated Rapid [(11)C]Carbonylation Using Arylboronate and [(11)C]Carbon Monoxide.

    Science.gov (United States)

    Takashima-Hirano, Misato; Ishii, Hideki; Suzuki, Masaaki

    2012-10-11

    (11)C-labeled methylbenzoates [(11)C]4a-d were synthesized using Pd(0)-mediated rapid cross-coupling reactions employing [(11)C]carbon monoxide and arylboronic acid neopentyl glycol esters 3a-d under atmospheric pressure in methanol-dimethylformamide (MeOH-DMF), in radiochemical yields of 12 ± 5-26 ± 13% (decay-corrected based on [(11)C]O). The reaction conditions were highly favorable for the synthesis of [(11)C]Am80 ([(11)C]2) and [(11)C]methyl 4-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)carbamoyl)benzoate ([(11)C]2-Me) using 4-(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)-N-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)benzamide (5), both of which produced a decay-corrected radiochemical yield (RCY) of 26 ± 13%, with >99% radiochemical purity and an average specific radioactivity of 44 GBq/μmol. The yields of [(11)C]4a, [(11)C]2-Me, and [(11)C]2 were improved by the use of a 2-fold excess of the solvents and reagents under the same conditions to give respective yields of 66 ± 8, 65 ± 7, and 48 ± 2%.

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

    International Nuclear Information System (INIS)

    Amin, Munib

    2008-12-01

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

  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. Future carbon beams at SPIRAL1 facility: Which method is the most efficient?

    Science.gov (United States)

    Maunoury, L.; Delahaye, P.; Angot, J.; Dubois, M.; Dupuis, M.; Frigot, R.; Grinyer, J.; Jardin, P.; Leboucher, C.; Lamy, T.

    2014-02-01

    Compared to in-flight facilities, Isotope Separator On-Line ones can in principle produce significantly higher radioactive ion beam intensities. On the other hand, they have to cope with delays for the release and ionization which make the production of short-lived isotopes ion beams of reactive and refractory elements particularly difficult. Many efforts are focused on extending the capabilities of ISOL facilities to those challenging beams. In this context, the development of carbon beams is triggering interest [H. Frånberg, M. Ammann, H. W. Gäggeler, and U. Köster, Rev. Sci. Instrum. 77, 03A708 (2006); M. Kronberger, A. Gottberg, T. M. Mendonca, J. P. Ramos, C. Seiffert, P. Suominen, and T. Stora, in Proceedings of the EMIS 2012 [Nucl. Instrum. Methods Phys. Res. B Production of molecular sideband radioisotope beams at CERN-ISOLDE using a Helicon-type plasma ion source (to be published)]: despite its refractory nature, radioactive carbon beams can be produced from molecules (CO or CO2), which can subsequently be broken up and multi-ionized to the required charge state in charge breeders or ECR sources. This contribution will present results of experiments conducted at LPSC with the Phoenix charge breeder and at GANIL with the Nanogan ECR ion source for the ionization of carbon beams in the frame of the ENSAR and EMILIE projects. Carbon is to date the lightest condensable element charge bred with an ECR ion source. Charge breeding efficiencies will be compared with those obtained using Nanogan ECRIS and charge breeding times will be presented as well.

  11. Digital-image-correlation-based experimental stress analysis of reinforced concrete beams strengthened using carbon composites

    Science.gov (United States)

    Helm, Jeffrey; Kurtz, Stephen

    2005-01-01

    The strengthening of reinforced concrete beams through the use of epoxy-bonded carbon composites has been widely researched in the United States since 1991. Despite the widespread attention of researchers, however, there are no reliable methods of predicting the failure of the repaired and strengthened beams by peeling of the fiber reinforced polymer (FRP) material from the parent concrete. To better understand peeling failure, several investigators have presented analytical work to predict the distribution of stresses along the interface between the FRP and the concrete. Several closed-form solutions can be found in the literature to predict the levels of shear stress present between the bonded composite plate and the parent concrete beam. However, there has been very little experimental verification of these analytical predictions because few experiments on large-scale beams have had sufficient instrumentation to facilitate the comparison. Some experiments have been presented1 in which electrical resistance strain gages were placed along the length of the carbon plate in order to deduce the interfacial shear stress using first differences. This method, though very crude, demonstrated that there are substantial differences between the distributions of interfacial shear stresses in actual repaired beams versus the analytical predictions. This paper presents a new test program in which large-scale carbon-fiber-strengthened reinforced concrete beams are load-tested to failure, while employing digital image correlation (DIC) to record the strains in the carbon fiber plate. Relying on the linear elasticity of carbon fiber, the interfacial shear can be determined and compared with the analytical predictions of the literature. The focus of this paper is the presentation of the experimental shear stress distributions and comparisons of these distributions with previous results available in the literature.

  12. Evaluation of w values for carbon beams in air, using a graphite calorimeter.

    Science.gov (United States)

    Sakama, Makoto; Kanai, Tatsuaki; Fukumura, Akifumi; Abe, Kyoko

    2009-03-07

    Despite recent progress in carbon therapy, accurate values for physical data such as the w value in air or stopping power ratios for ionization chamber dosimetry have not been obtained. The absorbed dose to graphite obtained with the graphite calorimeter was compared with that obtained using the ionization chambers following the IAEA protocol in order to evaluate the w values in air for mono-energetic carbon beams of 135, 290, 400 and 430 MeV/n. Two cylindrical chambers (PTW type 30001 and PTW type 30011, Farmer) and two plane-parallel chambers (PTW type 23343, Markus and PTW type 34001, Roos) calibrated by the absorbed dose to graphite and exposure to the (60)Co photon beam were used. The comparisons to our calorimeter measurements revealed that, using the ionization chambers, the absorbed dose to graphite comes out low by 2-6% in this experimental energy range and with these chamber types and calibration methods. In the therapeutic energy range, the w values in air for carbon beams indicated a slight energy dependence; we, however, assumed these values to be constant for practical use because of the large uncertainty and unknown perturbation factors of the ionization chambers. The w values in air of the carbon beams were evaluated to be 35.72 J C(-1) +/- 1.5% in the energy range used in this study. This value is 3.5% larger than that recommended by the IAEA TRS 398 for heavy-ion beams. Using this evaluated result, the absorbed dose to water in the carbon beams would be increased by the same amount.

  13. Quasi-steady carbon plasma source for neutral beam injector

    International Nuclear Information System (INIS)

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

    2014-01-01

    Carbon plasma is successfully sustained during 1000 s without any carrier gas in the bucket type ionization chamber with cusp magnetic field. Every several seconds, seed plasmas having ∼3 ms duration time are injected into the ionization chamber by a shunting arch plasma gun. The weakly ionized carbon plasma ejected from the shunting arch is also ionized by 2.45 GHz microwave at the electron cyclotron resonance surface and the plasma can be sustained even in the interval of gun discharges. Control of the gun discharge interval allows to keep high pressure and to sustain the plasma for long duration

  14. Quasi-steady carbon plasma source for neutral beam injector.

    Science.gov (United States)

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

    2014-02-01

    Carbon plasma is successfully sustained during 1000 s without any carrier gas in the bucket type ionization chamber with cusp magnetic field. Every several seconds, seed plasmas having ∼3 ms duration time are injected into the ionization chamber by a shunting arch plasma gun. The weakly ionized carbon plasma ejected from the shunting arch is also ionized by 2.45 GHz microwave at the electron cyclotron resonance surface and the plasma can be sustained even in the interval of gun discharges. Control of the gun discharge interval allows to keep high pressure and to sustain the plasma for long duration.

  15. Experiments with the newly available carbon beams at ISOLDE

    CERN Multimedia

    Garcia borge, M J; Koester, U H; Koldste, G T

    2002-01-01

    Recent target-ions-source developments at ISOLDE providing significantly increased yields for carbon isotopes, open up for new and intriguing experiments. We propose to exploit this in two different ways. In particular we wish to do an elastic resonance scattering experiment of $^{9}$C on a proton target to gain information on the particle unbound system $^{10}$N. Furthermore we wish to perform decay experiments of the neutron-rich carbon isotopes, with special focus on $^{17-19}$C but also including a test to see whether the even more neutron-rich isotopes $^{20,22}$C are accessible at ISOLDE.

  16. Effects of ion beam bombardment of carbon thin films deposited onto tungsten carbide and tool steels

    Energy Technology Data Exchange (ETDEWEB)

    Awazu, Kaoru; Yoshida, Hiroyuki [Industrial Research Inst. of Ishikawa (Japan); Watanabe, Hiroshi [Gakushuin Univ., Tokyo (Japan); Iwaki, Masaya; Guzman, L [RIKEN, Saitama (Japan)

    1992-04-15

    A study was made of the effects of argon ion bombardment of carbon thin films deposited onto WC and tool steels. Carbon thin film deposition was performed at various temperatures ranging from 200degC to 350degC, using C{sub 6}H{sub 6} gas. Argon ion beam bombardment of the films was carried out at an energy of 150 keV with a dose of 1x10{sup 16} ions cm{sup -2}. The hardness and adhesion of the films were measured by means of Knoop hardness and scratch tests respectively. The structure of the carbon films was estimated by laser Raman spectroscopy, and the relations were investigated between the mechanical properties and the structure of the films. The hardness of carbon thin films increases as their deposition temperature decreases; this tendency corresponds to the increase in amorphous structure estimated by Raman spectra. Argon ion bombardment results in constant hardness and fraction of amorphous structure. Argon ion beam bombardment of films prior to additional carbon deposition may cause the adhesion of the subsequently deposited films to improve. It is concluded that argon ion beam bombardment is useful for improving the properties of carbon films deposited onto WC and tool steels. (orig.).

  17. Effects of ion beam bombardment of carbon thin films deposited onto tungsten carbide and tool steels

    International Nuclear Information System (INIS)

    Awazu, Kaoru; Yoshida, Hiroyuki; Watanabe, Hiroshi; Iwaki, Masaya; Guzman, L.

    1992-01-01

    A study was made of the effects of argon ion bombardment of carbon thin films deposited onto WC and tool steels. Carbon thin film deposition was performed at various temperatures ranging from 200degC to 350degC, using C 6 H 6 gas. Argon ion beam bombardment of the films was carried out at an energy of 150 keV with a dose of 1x10 16 ions cm -2 . The hardness and adhesion of the films were measured by means of Knoop hardness and scratch tests respectively. The structure of the carbon films was estimated by laser Raman spectroscopy, and the relations were investigated between the mechanical properties and the structure of the films. The hardness of carbon thin films increases as their deposition temperature decreases; this tendency corresponds to the increase in amorphous structure estimated by Raman spectra. Argon ion bombardment results in constant hardness and fraction of amorphous structure. Argon ion beam bombardment of films prior to additional carbon deposition may cause the adhesion of the subsequently deposited films to improve. It is concluded that argon ion beam bombardment is useful for improving the properties of carbon films deposited onto WC and tool steels. (orig.)

  18. DNA damage response signaling in lung adenocarcinoma A549 cells following gamma and carbon beam irradiation.

    Science.gov (United States)

    Ghosh, Somnath; Narang, Himanshi; Sarma, Asitikantha; Krishna, Malini

    2011-11-01

    Carbon beams (5.16MeV/u, LET=290keV/μm) are high linear energy transfer (LET) radiation characterized by higher relative biological effectiveness than low LET radiation. The aim of the current study was to determine the signaling differences between γ-rays and carbon ion-irradiation. A549 cells were irradiated with 1Gy carbon or γ-rays. Carbon beam was found to be three times more cytotoxic than γ-rays despite the fact that the numbers of γ-H2AX foci were same. Percentage of cells showing ATM/ATR foci were more with γ-rays however number of foci per cell were more in case of carbon irradiation. Large BRCA1 foci were found in all carbon irradiated cells unlike γ-rays irradiated cells and prosurvival ERK pathway was activated after γ-rays irradiation but not carbon. The noteworthy finding of this study is the early phase apoptosis induction by carbon ions. In the present study in A549 lung adenocarcinoma, authors conclude that despite activation of same repair molecules such as ATM and BRCA1, differences in low and high LET damage responses might be due to their distinct macromolecular complexes rather than their individual activation and the activation of cytoplasmic pathways such as ERK, whether it applies to all the cell lines need to be further explored. Copyright © 2011 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kupka, Katharina

    2016-08-15

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

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

    International Nuclear Information System (INIS)

    Kupka, Katharina

    2016-08-01

    Amorphous carbon or carbon-based stripper foils are commonly applied in accelerator technology for electron stripping of ions. At the planned facility for antiproton and ion research (FAIR) at the Helmholtzzentrum fuer Schwerionenforschung (GSI), Darmstadt, thin carbon stripper foils provide an option for directly delivering ions of intermediate charge states to the heavy ion synchrotron, SIS 18, in order to mitigate space charge limitations during high-intensity operation. In case of desired high end-energies in the synchrotron, a second stripping process by a thicker carbon foil provides ions of higher charge states for injection into the SIS18. High beam intensities and a pulsed beam structure as foreseen at FAIR pose new challenges to the stripper foils which experience enhanced degradation by radiation damage, thermal effects, and stress waves. In order to ensure reliable accelerator operation, radiation-hard stripper foils are required. This thesis aims to a better understanding of processes leading to degradation of carbon-based thin foils. Special focus is placed on ion-beam induced structure and physical property changes and on the influence of different beam parameters. Irradiation experiments were performed at the M3-beamline of the universal linear accelerator (UNILAC) at GSI, using swift heavy ion beams with different pulse lengths and repetition rates. Tested carbon foils were standard amorphous carbon stripper foils produced by the GSI target laboratory, as well as commercial amorphous and diamond-like carbon foils and buckypaper foils. Microstructural changes were investigated with various methods such as optical microscopy, scanning electron microscopy (SEM), profilometry and chromatic aberration measurements. For the investigation of structural changes X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), in-situ Fourier-transform infrared spectroscopy (FTIR) and small angle X

  1. Reactions of carbon atoms in pulsed molecular beams

    Energy Technology Data Exchange (ETDEWEB)

    Reisler, H. [Univ. of Southern California, Los Angeles (United States)

    1993-12-01

    This research program consists of a broad scope of experiments designed to unravel the chemistry of atomic carbon in its two spin states, P and D, by using well-controlled initial conditions and state-resolved detection of products. Prerequisite to the proposed studies (and the reason why so little is known about carbon atom reactions), is the development of clean sources of carbon atoms. Therefore, in parallel with the studies of its chemistry and reaction dynamics, the authors continuously explore new, state-specific and efficient ways of producing atomic carbon. In the current program, C({sup 3}P) is produced via laser ablation of graphite, and three areas of study are being pursued: (i) exothermic reactions with small inorganic molecules (e.g., O{sub 2}, N{sub 2}O, NO{sub 2}) that can proceed via multiple pathways; (ii) the influence of vibrational and translational energy on endothermic reactions involving H-containing reactants that yield CH products (e.g., H{sub 2}O H{sub 2}CO); (iii) reactions of C({sup 3}P) with free radicals (e.g., HCO, CH{sub 3}O). In addition, the authors plan to develop a source of C({sup 1}D) atoms by exploiting the pyrolysis of diazotetrazole and its salts in the ablation source. Another important goal involves collaboration with theoreticians in order to obtain relevant potential energy surfaces, rationalize the experimental results and predict the roles of translational and vibrational energies.

  2. Free vibrations and buckling analysis of carbon nanotube-reinforced composite Timoshenko beams on elastic foundation

    International Nuclear Information System (INIS)

    Yas, M.H.; Samadi, N.

    2012-01-01

    This study deals with free vibrations and buckling analysis of nanocomposite Timoshenko beams reinforced by single-walled carbon nanotubes (SWCNTs) resting on an elastic foundation. The SWCNTs are assumed to be aligned and straight with a uniform layout. Four different carbon nanotubes (CNTs) distributions including uniform and three types of functionally graded distributions of CNTs through the thickness are considered. The rule of mixture is used to describe the effective material properties of the nanocomposite beams. The governing equations are derived through using Hamilton's principle and then solved by using the generalized differential quadrature method (GDQM). Natural frequencies and critical buckling load are obtained for nanocomposite beams with different boundary conditions. Effects of several parameters, such as nanotube volume fraction, foundation stiffness parameters, slenderness ratios, CNTs distribution and boundary conditions on both natural frequency and critical buckling load are investigated. The results indicate that the above-mentioned parameters play a very important role on the free vibrations and buckling characteristics of the beam. Highlights: ► Beams with FG-X distribution have highest fundamental frequency. ► Beams with FG-X distribution have highest critical buckling load. ► Using elastic foundation, lead to increase the natural frequency. ► Using elastic foundation, lead to increase the critical buckling load. ► Increasing CNT volume fraction, lead to increase the natural frequency.

  3. Microdosimetry for a carbon ion beam using track-etched detectors

    International Nuclear Information System (INIS)

    Ambrozova, I.; Ploc, O.; Davidkova, M.; Vondracek, V.; Sefl, M.; Stepan, V.; Pachnerova Brabcova, K.; Incerti, S.

    2015-01-01

    Track-etched detectors (TED) have been used as linear energy transfer (LET) spectrometers in heavy ion beams for many years. LET spectra and depth -dose distribution of a carbon ion beam were measured behind polymethylmethacrylate degraders at Heavy Ion Medical Accelerator in Chiba, Japan. The measurements were performed along monoenergetic beam with energy 290 MeV u -1 in different positions: (1) at beam extraction area, (2) at beginning, (3) maximum and (4) behind the Bragg peak region (0, 117, 147 and 151 mm of water-equivalent depth, respectively). The LET spectra inside and outside of the primary ion beam have been evaluated. TED record only heavy charged particles with LET above 8 -10 keV μm -1 , while electrons and ions with lower LET are not detected. The Geant4 simulation toolkit version 4.9.6.P01 has been used to estimate the contribution of non-detected particles to absorbed dose. Presented results demonstrate the applicability of TED for microdosimetry measurements in therapeutic carbon ion beams. (authors)

  4. Precipitation as driver of carbon fluxes in 11 African ecosystems

    CSIR Research Space (South Africa)

    Merbold, L

    2009-01-01

    Full Text Available ). Given the shortness of the record, the EC data were analysed across the network rather than longitudinally at sites, in order to under- stand the driving factors for ecosystem respiration and car- bon assimilation, and to reveal the different water... by Schulze et al. (1994) and the thick solid regression line shows the regression for the eleven African sites. (n=11) variability in the global terrestrial cycles of water and car- bon (Williams et al., 2007; Weber et al., 2009). More- over, all African...

  5. Effects of substrate material on carbon films grown by laser molecular beam epitaxy

    International Nuclear Information System (INIS)

    Liu, M.; Xu, X.Y.; Man, B.Y.; Kong, D.M.; Xu, S.C.

    2012-01-01

    Highlights: ► We prepared tri-layers by laser molecular beam epitaxy (LMBE) on sapphire substrate. ► We found that the formation of the graphene film has a strong relation to the structure and properties of the substrate. ► The different carbon film formation mechanism of the buffer layers can affect the morphology of the film. - Abstract: The carbon thin films were grown on different substrates with different buffer layers by laser molecular beam epitaxy (LMBE) with a high purity graphite carbon target. A UV pulsed KrF excimer laser with a wavelength of 248 nm was used as laser source. The structure, surface morphology and other properties of the carbon thin films were characterized by Raman spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED) and atomic force microscopy (AFM). The results show that the properties of the carbon thin films and the formation of the graphene film have a strong relation to the structure and properties of the substrate. The substrate with a hexagonal wurtzite structure which is similar to the hexagonal honeycomb structure of the carbon atoms arranged in the graphene is more beneficial for the formation of the graphene thin film. In our experiment conditions, the carbon films grown on sapphire substrates with different buffer layers have an ordered structure and a smooth surface, and form high quality tri-layer graphene films.

  6. Dibenzodiazepines (clozapine) and analogues were labelled with carrier-free carbon-11 and fluorine-18

    International Nuclear Information System (INIS)

    Bender, D.

    1993-12-01

    Pharmacologically active dibenzodiazepines were labelled with carbon-11 and fluorine-18, in particular the atypical neuroleptic clozapine (8-Cl-11-(4-methyl-1-piperazinyl)-5H-dibenzo[b,e]-[1,4]-diazepine) for pharmakokinetic studies with positron emission tomography (PET). (orig./EF)

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

    International Nuclear Information System (INIS)

    Kupka, K.; Tomut, M.; Simon, P.; Hubert, C.; Romanenko, A.; Lommel, B.; Trautmann, C.

    2015-01-01

    At the future FAIR facility, reliably working solid carbon stripper foils are desired for providing intermediate charge states to SIS18. With the expected high beam intensities, the foils experience enhanced degradation and limited lifetime due to severe radiation damage, stress waves, and thermal effects. This work presents systematic measurements of the temperature of different carbon-based stripper foils (amorphous, diamond-like, and carbon-nanotube based) exposed to 4.8 MeV/u U, Bi, and Au beams of different pulse intensities. Thermal and spectroscopic analyses were performed by means of infrared thermography and Fourier transform infrared spectroscopy. The resulting temperature depends on the foil thickness and strongly increases with increasing pulse intensity and repetition rate. (author)

  8. Experimental study on fatigue crack propagation rate of RC beam strengthened with carbon fiber laminate

    Science.gov (United States)

    Huang, Peiyan; Liu, Guangwan; Guo, Xinyan; Huang, Man

    2008-11-01

    The experimental research on fatigue crack propagation rate of reinforced concrete (RC) beams strengthened with carbon fiber laminate (CFL) is carried out by MTS system in this paper. The experimental results show that, the main crack propagation on strengthened beam can be summarized into three phases: 1) fast propagation phase; 2) steady propagation and rest phase; 3) unsteady propagation phase. The phase 2-i.e. steady propagation and rest stage makes up about 95% of fatigue life of the strengthened beam. The propagation rate of the main crack, da/dN, in phase 2 can be described by Paris formula, and the constant C and m can be confirmed by the fatigue crack propagation experiments of the RC beams strengthened with CFL under three-point bending loads.

  9. Total cyanide mass measurement with micro-ion selective electrode for determination of specific activity of carbon-11 cyanide.

    Science.gov (United States)

    Shea, Colleen; Alexoff, David L; Kim, Dohyun; Hoque, Ruma; Schueller, Michael J; Fowler, Joanna S; Qu, Wenchao

    2015-08-01

    In this research, we aim to directly measure the specific activity (SA) of the carbon-11 cyanide ([(11)C]CN¯) produced by our in-house built automated [(11)C]HCN production system and to identify the major sources of (12)C-cyanide ((12)CN¯). The [(11)C]CN¯ is produced from [(11)C]CO2, which is generated by the (14)N(p,α)(11)C nuclear reaction using a cyclotron. Direct measurement of cyanide concentrations was accomplished using a relatively inexpensive, and easy to use ion selective electrode (ISE) which offered an appropriate range of sensitivity for detecting mass. Multiple components of the [(11)C]HCN production system were isolated in order to determine their relative contributions to (12)CN¯ mass. It was determined that the system gases were responsible for approximately 30% of the mass, and that the molecular sieve/nickel furnace unit contributed approximately 70% of the mass. Beam on target (33µA for 1 and 10min) did not contribute significantly to the mass. Additionally, we compared the SA of our [(11)C]HCN precursor determined using the ISE to the SA of our current [(11)C]CN¯ derived radiotracers determined by HPLC to assure there was no significant difference between the two methods. These results are the first reported use of an ion selective electrode to determine the SA of no-carrier-added cyanide ion, and clearly show that it is a valuable, inexpensive and readily available tool suitable for this purpose. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Development of [11C]/[3H]THK-5351 – A potential novel carbon-11 tau imaging PET radioligand

    International Nuclear Information System (INIS)

    Stepanov, Vladimir; Svedberg, Marie; Jia, Zhisheng; Krasikova, Raisa; Lemoine, Laetitia; Okamura, Nobujuki; Furumoto, Shozo; Mitsios, Nicholas; Mulder, Jan; Långström, Bengt; Nordberg, Agneta; Halldin, Christer

    2017-01-01

    Introduction: Due to the rise in the number of patients with dementia the imperative for finding new diagnostic and treatment options becomes ever more pressing. While significant progress has been made in PET imaging of Aβ aggregates both in vitro and in vivo, options for imaging tau protein aggregates selectively are still limited. Based on the work previously published by researchers from the Tohoku University, Japan, that resulted in the development of [ 18 F]THK-5351, we have undertaken an effort to develop a carbon-11 version of the identical structure - [ 11 C]THK-5351. In parallel, THK-5351 was also labeled with tritium ([ 3 H]THK-5351) for use in in vitro autoradiography (ARG). Methods: The carbon-11 labeling was performed starting with di-protected enantiomeric pure precursor - tert-butyl 5-(6-((2S)-3-fluoro-2-(tetrahydro-2H-pyran-2-yloxy)propoxy)quinolin-2-yl) pyridin-2-yl carbamate, which was reacted with [ 11 C]MeI, using DMF as the solvent and NaH as base, followed by deprotection with trifluoroacetic acid/water mixture, resulting in enantiomerically pure carbon-11 radioligand, [ 11 C]THK-5351 - (S)-1-fluoro-3-(2-(6-([ 11 C]methylamino)pyridin-3-yl)quinolin-6-yloxy) propan-2-ol. Tritium labeling and purification of [ 3 H]THK-5351 were undertaken using similar approach, resulting in [ 3 H]THK-5351 with RCP >99.8% and specific radioactivity of 1.3 GBq/μmol. Results: [ 11 C]THK-5351 was produced in good yield (1900 ± 355 MBq), specific radioactivity (SRA) (361 ± 119 GBq/μmol at EOS + 20 min) and radiochemical purity (RCP) (>99.8%), with enantiomeric purity of 98.7%. [ 3 H]THK-5351 was evaluated for ARG of tau binding in post-mortem human brain tissue using cortical sections from one AD patient and one control subject. [ 3 H]THK-5351 binding density was higher in the AD patient compared to the control subject, the binding was displaced by unlabeled THK-5351 confirming specific [ 3 H]THK-5351 binding.

  11. Synthesis of n. c. a. PET-radiotracers with carbon-11. Zur Synthese traegerarme PET-Radiotracer mit Kohlenstoff-11

    Energy Technology Data Exchange (ETDEWEB)

    Schirbel, A.

    1998-11-01

    Carbon-11 offers the unique possibility of authentic labelling of molecules as radioindicators for non invasive and quantitative determination of physiological functions via positron emission tomography (PET). Therefore, the goal of this thesis was to synthesize of different n.c.a. [sup 11]C-labelled pharmaceuticals for in vivo distribution studies with PET. For the determination of the pharmacokinetics of [1-[sup 11]C]acetate in porcine myocardium during prolonged ischemia, n.c.a. [1-[sup 11]C]acetate was synthesized via carboxylation of methylmagnesium bromide with in target produced n.c.a. [[sup 11]C]CO[sub 2] with a radiochemical yield (RCY) of 68 [+-] 7%. The fast (18 min) and reliable radiosynthesis allowed for repeated tracer administration at short intervals (<20 min). In order to study the pharmacokinetics and metabolism of acetylsalicylic acid (Aspirin[sup R]c) in humans, [1-[sup 11]C]acetylsalicylic acid, acetyl-[carboxy-[sup 11]C]salicylic acid and [carboxy-[sup 11]C]salicylic acid were prepared. N.c.a. [1-[sup 11]C]acetylsalicylic acid was synthesized via the reaction of [1-[sup 11]C]acetylchloride with salicylic acid salts. The use of the silver salt proved to be superior to the sodium salt and resulted in radiochemical yields of 32 [+-] 5%. Base-line (clean) separation of the labelled product was achieved using radio-HPLC. With regard to the preparation of n.c.a. [carboxy-[sup 11]C]salicylic acid, several protected and unprotected phenol derivates were metallated and subsequently carboxylated using n.c.a. [[sup 11]C]CO[sub 2]. Best results (87 [+-] 3% RCY) could be achieved with 2-(methoxymethoxy)-phenylmagnesium iodide as a precursor and subsequent quantitative cleavage of the MOM-group. Acetylation of n.c.a. [carboxy-[sup 11]C]salicylic acid to acetyl-[carboxy-[sup 11]C]salicylic acid was performed using acetylchloride in CH[sub 2]Cl[sub 2] with a radiochemical yield of 65 [+-] 4%. (orig.)

  12. Vacuum performance of a carbon fibre cryosorber for the LHC LSS beam screen

    CERN Document Server

    Anashin, V V; Dostovalov, R V; Korotaeva, Z A; Krasnov, A A; Malyshev, O B; Poluboyarov, V A

    2004-01-01

    A new carbon fibre material was developed at the Institute of Solid State Chemistry and Mechanochemistry at the Siberian Branch of the Russian Academy of Science (SB RAS) to meet the large hadron collider (LHC) vacuum chamber. The material must have a large sorbing capacity, a certain pumping speed, a working temperature range between 5 and 20K, a low activation temperature (below room temperature), a certain size in order to fit into the limited space available and it should be easy to mount. The vacuum parameters of the LHC vacuum chamber prototype with a carbon fibre cryosorber mounted onto the beam screen were studied in the beam screen temperature range from 14 to 25K at the Budker Institute of Nuclear Physics SB RAS. This carbon fibre material has shown sufficient sorption capacity for hydrogen at operational temperatures of the beam screen in the LHC long straight sections. It is also very important that this material does not crumble and makes a convenient fixation onto the beam screen in comparison t...

  13. The influence of lateral beam profile modifications in scanned proton and carbon ion therapy: a Monte Carlo study

    CERN Document Server

    Parodi, K; Kraemer, M; Sommerer, F; Naumann, J; Mairani, A; Brons, S

    2010-01-01

    Scanned ion beam delivery promises superior flexibility and accuracy for highly conformal tumour therapy in comparison to the usage of passive beam shaping systems. The attainable precision demands correct overlapping of the pencil-like beams which build up the entire dose distribution in the treatment field. In particular, improper dose application due to deviations of the lateral beam profiles from the nominal planning conditions must be prevented via appropriate beam monitoring in the beamline, prior to the entrance in the patient. To assess the necessary tolerance thresholds of the beam monitoring system at the Heidelberg Ion Beam Therapy Center, Germany, this study has investigated several worst-case scenarios for a sensitive treatment plan, namely scanned proton and carbon ion delivery to a small target volume at a shallow depth. Deviations from the nominal lateral beam profiles were simulated, which may occur because of misaligned elements or changes of the beam optic in the beamline. Data have been an...

  14. Nanoscale Soldering of Positioned Carbon Nanotubes using Highly Conductive Electron Beam Induced Gold Deposition

    DEFF Research Database (Denmark)

    Madsen, Dorte Nørgaard; Mølhave, Kristian; Mateiu, Ramona Valentina

    2003-01-01

    We have developed an in-situ method for controlled positioning of carbon nanotubes followed by highly conductive contacting of the nanotubes, using electron beam assisted deposition of gold. The positioning and soldering process takes place inside an Environmental Scanning Electron Microscope (E...... in a carbon matrix. Nanoscale soldering of multi-walled carbon nanotubes (MWNT) onto microelectrodes was achieved by deposition of a conducting gold line across a contact point between nanotube and electrode. The solderings were found to be mechanically stronger than the carbon nanotubes. We have positioned...... MWNTs to bridge the gap between two electrodes, and formed soldering bonds between the tube and each of the electrodes. All nanotube bridges showed ohmic resistances in the range 10-30 kΩ. We observed no increase in resistance after exposing the MWNT bridge to air for days....

  15. Flexural Strength of Carbon Fiber Reinforced Polymer Repaired Cracked Rectangular Hollow Section Steel Beams

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2015-01-01

    Full Text Available The flexural behavior of rectangular hollow section (RHS steel beams with initial crack strengthened externally with carbon fiber reinforced polymer (CFRP plates was studied. Eight specimens were tested under three-point loading to failure. The experimental program included three beams as control specimens and five beams strengthened with CFRP plates with or without prestressing. The load deflection curves were graphed and failure patterns were observed. The yield loads and ultimate loads with or without repairing were compared together with the strain distributions of the CFRP plate. It was concluded that yield loads of cracked beams could be enhanced with repairing. Meanwhile, the ultimate loads were increased to some extent. The effect of repair became significant with the increase of the initial crack depth. The failure patterns of the repaired specimens were similar to those of the control ones. Mechanical clamping at the CFRP plate ends was necessary to avoid premature peeling between the CFRP plate and the steel beam. The stress levels in CFRP plates were relatively low during the tests. The use of prestressing could improve the utilization efficiency of CFRP plates. It could be concluded that the patching repair could be used to restore the load bearing capacity of the deficient steel beams.

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

    International Nuclear Information System (INIS)

    Valizadeh, R.; Colligon, J.S.; Katardiev, I.V.; Faunce, C.A.; Donnelly, S.E.

    1998-01-01

    Full text: Carbon nitride films have been deposited on Si (100) by ion beam sputtering a vitreous graphite target with nitrogen and argon ions with and without concurrent N2 ion bombardment at room temperature. The sputtering beam energy was 1000 eV and the assisted beam energy was 300 eV with ion / atom arrival ratio ranging from 0.5 to 5. The carbon nitride films were deposited both as single layer directly on silicon substrate and as multilayer between two layers of stoichiometric amorphous silicon nitride and polycrystalline titanium nitride. The deposited films were implanted ex-situ with 30 keV nitrogen ions with various doses ranging from 1E17 to 4E17 ions.cm -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 C 3 N 4 was achieved by post nitrogen implantation of the multi-layered films. Post bombardment of single layer carbon nitride films lead to reduction in the total nitrogen concentration. Carbon K edge structure obtained from PEELS analysis suggested that the amorphous C 3 N 4 matrix was predominantly sp 2 bonded. This was confirmed by Fourier Transforrn Infra-Red Spectroscopy (FTIR) analysis of the single CN layer which showed the nitrogen was mostly bonded with carbon in nitrile (C≡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

  17. Study of corrosion behavior of carbon steel under seawater film using the wire beam electrode method

    International Nuclear Information System (INIS)

    Liu, Zaijian; Wang, Wei; Wang, Jia; Peng, Xin; Wang, Yanhua; Zhang, Penghui; Wang, Haijie; Gao, Congjie

    2014-01-01

    Corrosion behavior of carbon steel under seawater film with various thickness was investigated by the wire beam electrode (WBE) method. It was found that the corrosion rate of carbon steel increased significantly under thin seawater film than it was immersed in seawater. The current variation under seawater film indicated that the thickness of diffusion layer of oxygen was about 500 μm, and the maximal current appeared around 40 μm, at which corrosion rate transited from cathodic control to anodic control. The results suggest that WBE method is helpful to study the corrosion process under thin electrolyte film

  18. Carbon nitride films synthesized by NH3-ion-beam-assisted deposition

    International Nuclear Information System (INIS)

    Song, H.W.; Cui, F.Z.; He, X.M.; Li, W.Z.; Li, H.D.

    1994-01-01

    Carbon nitride thin film films have been prepared by NH 3 -ion-beam-assisted deposition with bombardment energies of 200-800 eV at room temperature. These films have been characterized by transmission electron microscopy. Auger electron spectroscopy and x-ray photoelectron spectroscopy for chemical analysis. It was found that the structure of the films varied with the bombardment energy. In the case of 400 eV bombardment, the tiny crystallites immersed on an amorphous matrix were identified to be β-C 3 N 4 . X-ray photoelectron spectroscopy indicated that some carbon atoms and nitrogen atoms form unpolarized covalent bonds in these films. (Author)

  19. Preparation of carbon-11 labelled phenylalanine and phenylglycine by a new amino acid synthesis

    International Nuclear Information System (INIS)

    Vaalburg, W.; Beerling-van der Molen, H.D.; Reiffers, S; Rijskamp, A.; Woldring, M.G.; Wynberg, H.

    1976-01-01

    Of the cyclotron-produced short-lived isotopes carbon-11 (tsub(1/2) = 20.4 min;β + ) is one of the most promising as label for radiopharmaceuticals. To prepare 11 C-labelled amino acids for evaluation as pancreas scanning agents a new rapid amino acid synthesis was developed. The method is based on the carboxylation of α-lithioisocyanides with 11 CO 2 , followed by hydrolysis of the intermediate reaction product to the desired amino acid. By this method DL-α-phenylalanine-1- 11 C and DL-α-phenylglycine-1- 11 C were prepared. The precursor 11 CO 2 was produced via the 14 N(p,α) 11 C reaction by bombardment of a flow of nitrogen gas mixed with 0.1% 0 2 with 20 MeV protons. The target system is described. (author)

  20. Monitoring of Carbon Fiber-Reinforced Old Timber Beams via Strain and Multiresonant Acoustic Emission Sensors.

    Science.gov (United States)

    Rescalvo, Francisco J; Valverde-Palacios, Ignacio; Suarez, Elisabet; Roldán, Andrés; Gallego, Antolino

    2018-04-17

    This paper proposes the monitoring of old timber beams with natural defects (knots, grain deviations, fissures and wanes), reinforced using carbon composite materials (CFRP). Reinforcement consisted of the combination of a CFRP laminate strip and a carbon fabric discontinuously wrapping the timber element. Monitoring considered the use and comparison of two types of sensors: strain gauges and multi-resonant acoustic emission (AE) sensors. Results demonstrate that: (1) the mechanical behavior of the beams can be considerably improved by means of the use of CFRP (160% in bending load capacity and 90% in stiffness); (2) Acoustic emission sensors provide comparable information to strain gauges. This fact points to the great potential of AE techniques for in-service damage assessment in real wood structures.

  1. Advanced stabilization of PAN fibers for fabrication of carbon fibers by e-beam irradiation

    International Nuclear Information System (INIS)

    Jeun, Joon Pyo; Kim, Du Young; Shin, Hye Kyoung; Kang, Phil Hyun; Park, Jung Ki

    2012-01-01

    In recent years, the carbon fiber industry has been growing rapidly to meet the demand from efferent industries such as aerospace, military, turbine blades, light weight cylinders and pressure vessels. Generally, carbon fibers are manufactured by a controlled pyrolysis of stabilized precursor fiber such as polyacrylonitrile (PAN). In the stabilization step, the linear PAN molecules are first converted to cyclic structure. However, cyclization is a very complicated process and there are still differences of opinion on the reaction mechanisms. Photo-induced crosslinking and stabilization of PAN via ion beam, X-ray, gamma ray and UV irradiation has been reported in the literature. However, the process required a long stabilization time. In this work, a new and highly effective method of pretreatment PAN precursor fiber was described. The effect of the e-beam on the stabilization process of the fibers was investigated using differential scanning calorimeter (DSC) and X-ray diffraction (XRD) measurement

  2. Monitoring of Carbon Fiber-Reinforced Old Timber Beams via Strain and Multiresonant Acoustic Emission Sensors

    Directory of Open Access Journals (Sweden)

    Francisco J. Rescalvo

    2018-04-01

    Full Text Available This paper proposes the monitoring of old timber beams with natural defects (knots, grain deviations, fissures and wanes, reinforced using carbon composite materials (CFRP. Reinforcement consisted of the combination of a CFRP laminate strip and a carbon fabric discontinuously wrapping the timber element. Monitoring considered the use and comparison of two types of sensors: strain gauges and multi-resonant acoustic emission (AE sensors. Results demonstrate that: (1 the mechanical behavior of the beams can be considerably improved by means of the use of CFRP (160% in bending load capacity and 90% in stiffness; (2 Acoustic emission sensors provide comparable information to strain gauges. This fact points to the great potential of AE techniques for in-service damage assessment in real wood structures.

  3. Tracer kinetics of plants carbon allocation with continuously produced 11CO2

    International Nuclear Information System (INIS)

    Fares, Y.; Goeschl, J.D.; Magnuson, C.E.; Strain, B.R.

    1988-01-01

    Parameters of carbon allocation dynamics in plants were measured using 11 CO 2 and tracer kinetics techniques. Mechanical agitation reduced carbon export rate (CER) by 33% in cotton seedling's leaf, while storage rate and export pool size increased. Carbon storage and export rates of C 4 bunch grasses were higher in the afternoon than in the morning in spite of the decrease in CER. Water stress of cotton seedlings caused reduction in CER, and increase in exportable products concentrations and rate of storage. By the third stress day, measurable decreases in CER, transpiration, export rate and export pool size were recorded. (author) 17 refs.; 8 figs.; 1 tab

  4. Advanced carbon-based material C60 modification using partially ionized cluster and energetic beams

    International Nuclear Information System (INIS)

    Du Yuancheng; Ren Zhongmin; Ning Zhifeng; Xu Ning; Li Fuming

    1997-01-01

    Two processes have been undertaken using Partially ionized cluster deposition (PICBD) and energetic ion bombardment beams deposition (IBD) respectively. C 60 films deposited by PICBD at V=0 and 65 V, which result in highly textured close-packed structure in orientation (110) and being more polycrystalline respectively, the resistance of C 60 films to oxygen diffusion contamination will be improved. In the case of PICBD, the ionized C 60 soccer-balls molecules in the evaporation beams will be fragmented in collision with the substrate under the elevated accelerating fields Va. As a new synthetic IBD processing, two low energy (400 and 1000 eV) nitrogen ion beams have been used to bombard C 60 films to synthesize the carbon nitride films

  5. Synthesis and electrochemical capacitive properties of nitrogen-doped porous carbon micropolyhedra by direct carbonization of zeolitic imidazolate framework-11

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Fei; Li, Li; Zhang, Xiaohua, E-mail: mickyxie@hnu.edu.cn; Chen, Jinhua, E-mail: chenjinhua@hnu.edu.cn

    2015-06-15

    Highlights: • Nitrogen-doped porous carbon micropolyhedra (N-PCMPs) were prepared from ZIF-11. • The activated N-PCMPs with fused KOH (N-PCMPs-A) have high specific surface area. • N-PCMPs-A exhibits high specific capacitance. • N-PCMPs-A reveals good cycling performance even at a high current density. - Abstract: Nitrogen-doped porous carbon micropolyhedra (N-PCMPs) were successfully prepared by direct carbonization of ZIF-11 polyhedra and further activated with fused KOH to obtain N-PCMPs-A. The morphology and microstructure of samples were examined by scanning electron microscopy, X-ray diffraction, and micropore and chemisorption analyzer. Electrochemical properties were characterized by cyclic voltammetry and galvanostatic charge/discharge method in 1.0 M H{sub 2}SO{sub 4} aqueous solution on a standard three-electrode system. Results show that, compared with N-PCMPs, N-PCMPs-A has higher specific surface area (2188 m{sup 2} g{sup −1}) and exhibits improved electrochemical capacitive properties (307 F g{sup −1} at 1.0 A g{sup −1}). The mass specific capacitance of N-PCMPs-A is also higher than that of most MOF-derived carbons, some carbide-derived carbons and carbon aerogel-derived carbons. In addition, the capacitance of the N-PCMPs-A retains 90% after 4000 cycles even at a high current density of 10 A g{sup −1}. These imply that N-PCMPs-A is the promising materials for the construction of a high-performance supercapacitor.

  6. Amorphous track modelling of luminescence detector efficiency in proton and carbon beams

    DEFF Research Database (Denmark)

    Greilich, Steffen; Grzanka, Leszek; Bassler, Niels

    assumptions in a variety of detectors. The library also includes simple particle transportation or can be interfaced to external transport codes. We applied our code to RL and OSL data from fiber-coupled Al2O3:C-detectors in a proton (nominal energies 10 MeV to 60 MeV) and a carbon beam (270 MeV/u). Results...

  7. Delamination of carbon-fiber strengthening layer from concrete beam during deformation (infrared thermography)

    OpenAIRE

    Shardakov, I. N.; Shestakov, A. P.; Bykov, A.A.

    2016-01-01

    Technology of strengthening reinforced concrete structures with composite materials has found wide application. The effectiveness of strengthening of concrete structures with externally bonded reinforcement is supported by a great deal of experimental evidence. However, the problem of serviceability of such structures has not been adequately explored. The present work describes the results of experimental studies on the loadcarrying capacity of concrete beams strengthened with carbon fiber re...

  8. Structural and optical properties of 70-keV carbon ion beam synthesized carbon nanoclusters in thermally grown silicon dioxide

    International Nuclear Information System (INIS)

    Poudel, P.R.; Poudel, P.P.; Paramo, J.A.; Strzhemechny, Y.M.; Rout, B.; McDaniel, F.D.

    2015-01-01

    The structural and optical properties of carbon nanoclusters formed in thermally grown silicon dioxide film via the ion beam synthesis process have been investigated. A low-energy (70 keV) carbon ion beam (C - ) at a fluence of 3 x 10 17 atoms/cm 2 was used for implantation into a thermally grown silicon dioxide layer (500 nm thick) on a Si (100) wafer. Several parts of the implanted samples were subsequently annealed in a gas mixture (4 % H 2 + 96 % Ar) at 900 C for different time periods. The as-implanted and annealed samples were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL). The carbon ion implantation depth profile was simulated using a widely used Monte Carlo-based simulation code SRIM-2012. Additionally, the elemental depth profile of the implanted carbon along with host elements of silicon and oxygen were simulated using a dynamic ion-solid interaction code T-DYN, which incorporates the effects of the surface sputtering and gradual change in the elemental composition in the implanted layers due to high-fluence ion implantation. The elemental depth profile obtained from the XPS measurements matches closely to the T-DYN predictions. Raman measurements indicate the formation of graphitic phases in the annealed samples. The graphitic peak (G-peak) was found to be increased with the annealing time duration. In the sample annealed for 10 min, the sizes of the carbon nanoclusters were found to be 1-4 nm in diameter using TEM. The PL measurements at room temperature using a 325-nm laser show broad-band emissions in the ultraviolet to visible range in the as-implanted sample. Intense narrow bands along with the broad bands were observed in the annealed samples. The defects present in the as-grown samples along with carbon ion-induced defect centers in the as-implanted samples are the main contributors to the observed

  9. Structural and optical properties of 70-keV carbon ion beam synthesized carbon nanoclusters in thermally grown silicon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Poudel, P.R. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States); Intel Corporation, Rio Rancho, NM (United States); Poudel, P.P. [University of Kentucky, Department of Chemistry, Lexington, KY (United States); Paramo, J.A.; Strzhemechny, Y.M. [Texas Christian University, Department of Physics and Astronomy, Fort Worth, TX (United States); Rout, B. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States); University of North Texas, Center for Advanced Research and Technology, Denton, TX (United States); McDaniel, F.D. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States)

    2014-09-18

    The structural and optical properties of carbon nanoclusters formed in thermally grown silicon dioxide film via the ion beam synthesis process have been investigated. A low-energy (70 keV) carbon ion beam (C{sup -}) at a fluence of 3 x 10{sup 17} atoms/cm{sup 2} was used for implantation into a thermally grown silicon dioxide layer (500 nm thick) on a Si (100) wafer. Several parts of the implanted samples were subsequently annealed in a gas mixture (4 % H{sub 2} + 96 % Ar) at 900 C for different time periods. The as-implanted and annealed samples were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL). The carbon ion implantation depth profile was simulated using a widely used Monte Carlo-based simulation code SRIM-2012. Additionally, the elemental depth profile of the implanted carbon along with host elements of silicon and oxygen were simulated using a dynamic ion-solid interaction code T-DYN, which incorporates the effects of the surface sputtering and gradual change in the elemental composition in the implanted layers due to high-fluence ion implantation. The elemental depth profile obtained from the XPS measurements matches closely to the T-DYN predictions. Raman measurements indicate the formation of graphitic phases in the annealed samples. The graphitic peak (G-peak) was found to be increased with the annealing time duration. In the sample annealed for 10 min, the sizes of the carbon nanoclusters were found to be 1-4 nm in diameter using TEM. The PL measurements at room temperature using a 325-nm laser show broad-band emissions in the ultraviolet to visible range in the as-implanted sample. Intense narrow bands along with the broad bands were observed in the annealed samples. The defects present in the as-grown samples along with carbon ion-induced defect centers in the as-implanted samples are the main

  10. Multi-walled carbon nanotube structural instability with/without metal nanoparticles under electron beam irradiation

    Science.gov (United States)

    Khan, Imran; Huang, Shengli; Wu, Chenxu

    2017-12-01

    The structural transformation of multi-walled carbon nanotubes (MWCNT) under electron beam (e-beam) irradiation at room temperature is studied, with respect to a novel passivation effect due to gold nanoparticles (Au NPs). MWCNT structural evolution induced by energetic e-beam irradiation leads to faster shrinkage, as revealed via in situ transmission electron microscopy, while MWCNT surface modification with Au NPs (Au-MWCNT) slows down the shrinkage by impeding the structural evolution process for a prolonged time under the same irradiation conditions. The new relationship between MWCNT and Au-MWCNT shrinking radii and irradiation time illustrates that the MWCNT shrinkage rate is faster than either theoretical predictions or the same process in Au-MWCNTs. As compared with the outer surface energy (positive curvature), the inner surface energy (negative curvature) of the MWCNT contributes more to the athermal evaporation of tube wall atoms, leading to structural instability and shrinkage under e-beam irradiation. Conversely, Au NPs possess only outer surface energy (positive curvature) compared with the MWCNT. Their presence on MWCNT surfaces retards the dynamics of MWCNT structural evolution by slowing down the evaporation process of carbon atoms, thus restricting Au-MWCNT shrinkage. Au NP interaction and growth evolves athermally on MWCNT surfaces, exhibits increase in their size, and indicates the association of this mechanism with the coalescence induced by e-beam activated electronic excitations. Despite their growth, Au NPs show extreme structural stability, and remain crystalline under prolonged irradiation. It is proposed that the surface energy of MWCNTs and Au NPs, together with e-beam activated soft modes or lattice instability effects, predominantly govern all the above varieties of structural evolution.

  11. Mini-TEPC Microdosimetric Study of Carbon Ion Therapeutic Beams at CNAO

    Science.gov (United States)

    Conte, V.; Colautti, P.; Chiriotti, S.; Moros, D.; Ciocca, M.; Mairani, A.

    2017-09-01

    Mono-energetic carbon ion scanning beams of 195.2 MeV/u at the Italian National Centre for Oncological Hadrontherapy (CNAO) have been used to study the microdosimetric features of an "active" carbon ion beam used in hadrontherapy. A 30x30 mm2 area has been scanned by a 6 mm beam with scanning steps of 2 mm. A mini TEPC of 0.57 mm3 has been used to perform measurements in a water phantom at different depths on the beam axis. The detector small size allowed for measuring, with good spatial resolution, also inside the relatively small Bragg peak region and inside the distal edge, where the radiation quality varies quickly. In spite of the high event rate (up to 105 s-1), no pile-up effects were observed. Results showed that the frequency-mean lineal energy scaled well with the absorbed dose. Moreover, the dose-mean lineal energy itself seemed to be a good descriptor of the radiation quality.

  12. Electrochemical impedance spectroscopy on nanostructured carbon electrodes grown by supersonic cluster beam deposition

    International Nuclear Information System (INIS)

    Bettini, Luca Giacomo; Bardizza, Giorgio; Podestà, Alessandro; Milani, Paolo; Piseri, Paolo

    2013-01-01

    Nanostructured porous films of carbon with density of about 0.5 g/cm 3 and 200 nm thickness were deposited at room temperature by supersonic cluster beam deposition (SCBD) from carbon clusters formed in the gas phase. Carbon film surface topography, determined by atomic force microscopy, reveals a surface roughness of 16 nm and a granular morphology arising from the low kinetic energy ballistic deposition regime. The material is characterized by a highly disordered carbon structure with predominant sp2 hybridization as evidenced by Raman spectroscopy. The interface properties of nanostructured carbon electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy employing KOH 1 M solution as aqueous electrolyte. An increase of the double layer capacitance is observed when the electrodes are heat treated in air or when a nanostructured nickel layer deposited by SCBD on top of a sputter deposited film of the same metal is employed as a current collector instead of a plain metallic film. This enhancement is consistent with an improved charge injection in the active material and is ascribed to the modification of the electrical contact at the interface between the carbon and the metal current collector. Specific capacitance values up to 120 F/g have been measured for the electrodes with nanostructured metal/carbon interface.

  13. Electrochemical impedance spectroscopy on nanostructured carbon electrodes grown by supersonic cluster beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bettini, Luca Giacomo; Bardizza, Giorgio; Podesta, Alessandro; Milani, Paolo; Piseri, Paolo, E-mail: piseri@mi.infn.it [Universita degli Studi di Milano, Dipartimento di Fisica and CIMaINa (Italy)

    2013-02-15

    Nanostructured porous films of carbon with density of about 0.5 g/cm{sup 3} and 200 nm thickness were deposited at room temperature by supersonic cluster beam deposition (SCBD) from carbon clusters formed in the gas phase. Carbon film surface topography, determined by atomic force microscopy, reveals a surface roughness of 16 nm and a granular morphology arising from the low kinetic energy ballistic deposition regime. The material is characterized by a highly disordered carbon structure with predominant sp2 hybridization as evidenced by Raman spectroscopy. The interface properties of nanostructured carbon electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy employing KOH 1 M solution as aqueous electrolyte. An increase of the double layer capacitance is observed when the electrodes are heat treated in air or when a nanostructured nickel layer deposited by SCBD on top of a sputter deposited film of the same metal is employed as a current collector instead of a plain metallic film. This enhancement is consistent with an improved charge injection in the active material and is ascribed to the modification of the electrical contact at the interface between the carbon and the metal current collector. Specific capacitance values up to 120 F/g have been measured for the electrodes with nanostructured metal/carbon interface.

  14. Electrochemical impedance spectroscopy on nanostructured carbon electrodes grown by supersonic cluster beam deposition

    Science.gov (United States)

    Bettini, Luca Giacomo; Bardizza, Giorgio; Podestà, Alessandro; Milani, Paolo; Piseri, Paolo

    2013-02-01

    Nanostructured porous films of carbon with density of about 0.5 g/cm3 and 200 nm thickness were deposited at room temperature by supersonic cluster beam deposition (SCBD) from carbon clusters formed in the gas phase. Carbon film surface topography, determined by atomic force microscopy, reveals a surface roughness of 16 nm and a granular morphology arising from the low kinetic energy ballistic deposition regime. The material is characterized by a highly disordered carbon structure with predominant sp2 hybridization as evidenced by Raman spectroscopy. The interface properties of nanostructured carbon electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy employing KOH 1 M solution as aqueous electrolyte. An increase of the double layer capacitance is observed when the electrodes are heat treated in air or when a nanostructured nickel layer deposited by SCBD on top of a sputter deposited film of the same metal is employed as a current collector instead of a plain metallic film. This enhancement is consistent with an improved charge injection in the active material and is ascribed to the modification of the electrical contact at the interface between the carbon and the metal current collector. Specific capacitance values up to 120 F/g have been measured for the electrodes with nanostructured metal/carbon interface.

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

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Shanwei [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhou, Libin, E-mail: libinzhou@impcas.ac.cn [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Li, Wenjian; Du, Yan [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Yu, Lixia; Feng, Hui; Mu, Jinhu [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Yuze [College of Life Science and Technology, Gansu Agricultural University, No. 1 Yingmen Village, Anning District, Lanzhou, Gansu Province 730070 (China)

    2016-09-15

    Carbon ion beam irradiation is a powerful method for creating mutants and has been used in crop breeding more and more. To investigate the effects of carbon ion beams on Lotus japonicus, dry seeds were irradiated by 80 MeV/u carbon ion beam at dosages of 0, 100, 200, 300, 400, 500 and 600 Gy. The germination rate, survival rate and root length of M{sub 1} populations were explored and the dose of 400 Gy was selected as the median lethal dose (LD{sub 50}) for a large-scale mutant screening. Among 2472 M{sub 2} plants, 127 morphological mutants including leaf, stem, flower and fruit phenotypic variation were found, and the mutation frequency was approximately 5.14%. Inter simple sequence repeat (ISSR) assays were utilized to investigate the DNA polymorphism between seven mutants and eight plants without phenotypic variation from M{sub 2} populations. No remarkable differences were detected between these two groups, and the total polymorphic rate was 0.567%.

  16. Control of Pre-treatment for Carbon Nanotube Synthesis Using Proton Ion Beam Irradiation

    International Nuclear Information System (INIS)

    Kim, Y. H.; Kim, D. W.; Lee, S. M.; Kim, W. J.

    2008-04-01

    The carbon nanotubes are the next generation material in fuel storage system, the gas sensor, the life science sensor or the nano-size transistor, the stiffener and the heat dissipation field. For use at appropriate position in various field, it must be developed that control technique makes carbon nanotubes with high performance synthesized at appropriate location. The density of the carbon nanotube is 1 - 2g/cm3 with aluminum (2 - 3g/cm3) to be light, the elastic modulus is the level where as many of as 30 - 50 times of iron's elastic modulus and thermal conductivity is similar to the diamond, electric conductivity is high as well above the metal. Generally, many researchers have tried to synthesize the carbon nanotubes of mm length unit using the hydrogen and porous substrate, which play a role of more activating the catalyst. The proton beam which consist of H+ was able to directly inject the hydrogen into target materials such as Ni, Co, Fe as well as transfer high activation energy to them. so we were able to carry out feasibility of controlling the porosity of thin film and substrate to synthesize carbon nanotubes. The pre-treatment method of existing which is used generally heat treatment and the ammonia controls has generated island of catalyst which has increased the surface to react the hydrocarbon. However, pre-treatment method of existing caused the random nuclear creation so it was hard to control the island size of catalyst. It was not enough to understand the porous effect against synthesis of carbon nanotubes deduced from altering various substrates. In this report, it is possible investigate how hydrogen and the porous effect influence on growth of carbon nanotubes through controlling the nuclear creation of catalysts directly and the porosity of them using proton beam

  17. Synthesis of carbon-11 labeled celecoxib derivatives as new candidate PET radioligands for imaging of inflammation

    International Nuclear Information System (INIS)

    Gao Mingzhang; Wang Min; Miller, Kathy D.; Hutchins, Gary D.; Zheng Qihuang

    2009-01-01

    Cyclooxygenase (prostaglandin endoperoxide synthase or COX) enzyme represents a particularly attractive target in inflammation processes for the development of both therapeutic agents and imaging agents. This study was designed to develop new radioligands for imaging of inflammation using the biomedical imaging technique positron emission tomography (PET). Carbon-11 labeled celecoxib derivatives, [ 11 C]methyl 2-(4-(5-p-tolyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)phenylsulfonamidooxy) acetate ([ 11 C]6e), [ 11 C]methyl 2-methyl-2-(4-(5-p-tolyl-3-(trifluoromethyl)-1H-pyrazol-1-yl) phenylsulfonamidooxy)propanoate ([ 11 C]6f), [ 11 C]methyl 2-(4-(5-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl) phenylsulfonamidooxy)acetate ([ 11 C]6g), and [ 11 C]methyl 2-methyl-2-(4-(5-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl) phenylsulfonamidooxy)propanoate ([ 11 C]6h), were prepared by O-[ 11 C]methylation of their corresponding precursors using [ 11 C]CH 3 OTf under basic condition and isolated by a simplified solid-phase extraction (SPE) method in 50-60% radiochemical yields based on [ 11 C]CO 2 and decay corrected to end of bombardment (EOB). The overall synthesis time from EOB was 15-20 min, the radiochemical purity was >99%, and the specific activity at end of synthesis (EOS) was 111-185 GBq/μmol.

  18. Focused-electron-beam-induced processing (FEBIP) for emerging applications in carbon nanoelectronics

    International Nuclear Information System (INIS)

    Fedorov, Andrei G.; Kim, Songkil; Henry, Mathias; Kulkarni, Dhaval; Tsukruk, Vladimir V.

    2014-01-01

    Focused-electron-beam-induced processing (FEBIP), a resist-free additive nanomanufacturing technique, is an actively researched method for ''direct-write'' processing of a wide range of structural and functional nanomaterials, with high degree of spatial and time-domain control. This article attempts to critically assess the FEBIP capabilities and unique value proposition in the context of processing of electronics materials, with a particular emphasis on emerging carbon (i.e., based on graphene and carbon nanotubes) devices and interconnect structures. One of the major hurdles in advancing the carbon-based electronic materials and device fabrication is a disjoint nature of various processing steps involved in making a functional device from the precursor graphene/CNT materials. Not only this multi-step sequence severely limits the throughput and increases the cost, but also dramatically reduces the processing reproducibility and negatively impacts the quality because of possible between-the-step contamination, especially for impurity-susceptible materials such as graphene. The FEBIP provides a unique opportunity to address many challenges of carbon nanoelectronics, especially when it is employed as part of an integrated processing environment based on multiple ''beams'' of energetic particles, including electrons, photons, and molecules. This avenue is promising from the applications' prospective, as such a multi-functional (electron/photon/molecule beam) enables one to define shapes (patterning), form structures (deposition/etching), and modify (cleaning/doping/annealing) properties with locally resolved control on nanoscale using the same tool without ever changing the processing environment. It thus will have a direct positive impact on enhancing functionality, improving quality and reducing fabrication costs for electronic devices, based on both conventional CMOS and emerging carbon (CNT/graphene) materials. (orig.)

  19. 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

  20. SU-F-J-11: Radiobiologically Optimized Patient Localization During Prostate External Beam Localization

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y; Gardner, S; Liu, C; Zhao, B; Wen, N; Brown, S; Chetty, I [Henry Ford Health System, Detroit, MI (United States)

    2016-06-15

    Purpose: To present a novel positioning strategy which optimizes radiation delivery with radiobiological response knowledge, and to evaluate its application during prostate external beam radiotherapy. Methods: Ten patients with low or intermediate risk prostate cancer were evaluated retrospectively in this IRB-approved study. For each patient, a VMAT plan was generated on the planning CT (PCT) to deliver 78 Gy in 39 fractions with PTV = prostate + 7 mm margin, except for 5mm in the posterior direction. Five representative pretreatment CBCT images were selected for each patient, and prostate, rectum, and bladder were delineated on all CBCT images. Each CBCT was auto-registered to the corresponding PCT. Starting from this auto-matched position (AM-position), a search for optimal treatment position was performed utilizing a score function based on radiobiological and dosimetric indices (D98-DTV, NTCP-rectum, and NTCP-bladder) for the daily target volume (DTV), rectum, and bladder. DTV was defined as prostate + 4 mm margin to account for intra-fraction motion as well as contouring variability on CBCT. We termed the optimal treatment position the radiobiologically optimized couch shift position (ROCS-position). Results: The indices, averaged over the 10 patients’ treatment plans, were (mean±SD): 77.7±0.2 Gy (D98-PTV), 12.3±2.7% (NTCP-rectum), and 53.2±11.2% (NTCP-bladder). The corresponding values calculated on all 50 CBCT images at the AM-positions were 72.9±11.3 Gy (D98-DTV), 15.8±6.4% (NTCP-rectum), and 53.0±21.1% (NTCP-bladder), respectively. In comparison, calculated on CBCT at the ROCS-positions, the indices were 77.0±2.1 Gy (D98-DTV), 12.1±5.7% (NTCP-rectum), and 60.7±16.4% (NTCP-bladder). Compared to autoregistration, ROCS-optimization recovered dose coverage to target volume and lowered the risk to rectum. Moreover, NTCPrectum for one patient remained high after ROCS-optimization and therefore could potentially benefit from adaptive planning

  1. Synthesis of carbon-11 labelled cyclopentyltheophylline: A radioligand for PET studies of adenosine receptors

    International Nuclear Information System (INIS)

    Yorke, J.C.; Prenant, C.; Crouzel, C.

    1990-01-01

    Adenosine is presently considered as a neuromodulator, and an adenosine system has been described including secretory neurons, with a diffused distribution, specific receptors and a re-uptake system distributed heterogeneously in different anatomic areas. In order to localize the adenosine receptors in vivo by PET, the authors have synthesized the carbon-11 labelled 8-cyclopentyltheophylline, a known adenosine antagonist of A 1 receptors

  2. Synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Wolf, A.P.

    1981-01-01

    A number of reviews, many of them recent, have appeared on various aspects of /sup 11/C, /sup 18/F and /sup 13/N-labeled radiotracers. This monograph treats the topic principally from the standpoint of synthetic organic chemistry while keeping in perspective the necessity of integrating the organic chemistry with the design and ultimate application of the radiotracer. Where possible, recent examples from the literature of organic synthesis are introduced to suggest potentially new routes which may be applied to problems in labeling organic molecules with the short-lived positron emitters, carbon-11, fluorine-18, and nitrogen-13. The literature survey of carbon-11, fluorine-18 and nitrogen-13 labeled compounds presented are of particular value to scientists working in this field. Two appendices are also included to provide supplementary general references. A subject index concludes this volume.

  3. Carbon-11 and Fluorine-18 Labeled Amino Acid Tracers for Positron Emission Tomography Imaging of Tumors

    Science.gov (United States)

    Sun, Aixia; Liu, Xiang; Tang, Ganghua

    2017-12-01

    Tumor cells have an increased nutritional demand for amino acids(AAs) to satisfy their rapid proliferation. Positron-emitting nuclide labeled AAs are interesting probes and are of great importance for imaging tumors using positron emission tomography (PET). Carbon-11 and fluorine-18 labeled AAs include the [1-11C] amino acids, labeling alpha-C- amino acids, the branched-chain of amino acids and N-substituted carbon-11 labeled amino acids. These tracers target protein synthesis or amino acid(AA) transport, and their uptake mechanism mainly involves AA transport. AA PET tracers have been widely used in clinical settings to image brain tumors, neuroendocrine tumors, prostate cancer, breast cancer, non–small cell lung cancer (NSCLC) and hepatocellular carcinoma. This review focuses on the fundamental concepts and the uptake mechanism of AAs, AA PET tracers and their clinical applications.

  4. Synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications

    International Nuclear Information System (INIS)

    Fowler, J.S.; Wolf, A.P.

    1981-01-01

    A number of reviews, many of them recent, have appeared on various aspects of 11 C, 18 F and 13 N-labeled radiotracers. This monograph treats the topic principally from the standpoint of synthetic organic chemistry while keeping in perspective the necessity of integrating the organic chemistry with the design and ultimate application of the radiotracer. Where possible, recent examples from the literature of organic synthesis are introduced to suggest potentially new routes which may be applied to problems in labeling organic molecules with the short-lived positron emitters, carbon-11, fluorine-18, and nitrogen-13. The literature survey of carbon-11, fluorine-18 and nitrogen-13 labeled compounds presented are of particular value to scientists working in this field. Two appendices are also included to provide supplementary general references. A subject index concludes this volume

  5. Localized surface grafting reactions on carbon nanofibers induced by gamma and e-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Evora, M.C., E-mail: cecilia@ieav.cta.br [Institute for Advanced Studies-IEAV/DCTA, Av. Cel Jose Alberto Albano do Amarante, 1-Putim, 12228-001 São Jose dos Campos, SP (Brazil); Araujo, J.R., E-mail: jraraujo@inmetro.gov.br [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil); Ferreira, E.H.M. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil); Strohmeier, B.R. [Thermo Fisher Scientific, 5225 Verona Road, Madison, WI 53711 (United States); Silva, L.G.A., E-mail: lgasilva@ipen.br [Institute for Nuclear and Energy Research- IPEN, Av. Prof lineu Prestes, 2242- Cidade Universitaria, 05508-000 SP (Brazil); Achete, C.A. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil)

    2015-04-30

    Graphical abstract: - Highlights: • Methodology for the functionalization of carbon nanofibers was investigated. • Two radiation sources were used to promote grafting reactions: gamma and electron beam. • We report the optimum inhibitor concentration to achieve the functionalization. • Surface of carbon nanofibers showed an increase of oxygen content after irradiation. • The radiation-induced graphitization did not damage the overall sp{sup 2} structure. - Abstract: Electron beam and gamma-ray irradiation have potential application to modify the carbon fiber nanostructures in order to produce useful defects in the graphitic structure and create reactive sites. In this study, the methodology to functionalize carbon nanofiber (CNF), via a radiation process and using acrylic acid as a source of oxygen functional groups, was investigated. The samples were submitted to a direct grafting radiation process with electron beam and gamma-ray source. Several parameters were changed such as: acrylic acid concentration, radiation dose and percentage of inhibitor necessary to achieve functionalization, with higher percentage of oxygen functional groups on CNF surface, and better dispersion. The better results achieved were when mixing CNF in a solution of acrylic acid with 6% of inhibitor (FeSO{sub 4}·7H{sub 2}O) and irradiated at 100 kGy. The samples were characterized by X-ray photoelectron spectroscopy and the surface composition (atomic%) showed a significant increase of oxygen content for the samples after irradiation. Also, the dispersion of the functionalized CNF in water was stable during months which may be a good indication that the functionalization process of CNF via ionizing radiation was successful.

  6. Localized surface grafting reactions on carbon nanofibers induced by gamma and e-beam irradiation

    International Nuclear Information System (INIS)

    Evora, M.C.; Araujo, J.R.; Ferreira, E.H.M.; Strohmeier, B.R.; Silva, L.G.A.; Achete, C.A.

    2015-01-01

    Graphical abstract: - Highlights: • Methodology for the functionalization of carbon nanofibers was investigated. • Two radiation sources were used to promote grafting reactions: gamma and electron beam. • We report the optimum inhibitor concentration to achieve the functionalization. • Surface of carbon nanofibers showed an increase of oxygen content after irradiation. • The radiation-induced graphitization did not damage the overall sp 2 structure. - Abstract: Electron beam and gamma-ray irradiation have potential application to modify the carbon fiber nanostructures in order to produce useful defects in the graphitic structure and create reactive sites. In this study, the methodology to functionalize carbon nanofiber (CNF), via a radiation process and using acrylic acid as a source of oxygen functional groups, was investigated. The samples were submitted to a direct grafting radiation process with electron beam and gamma-ray source. Several parameters were changed such as: acrylic acid concentration, radiation dose and percentage of inhibitor necessary to achieve functionalization, with higher percentage of oxygen functional groups on CNF surface, and better dispersion. The better results achieved were when mixing CNF in a solution of acrylic acid with 6% of inhibitor (FeSO 4 ·7H 2 O) and irradiated at 100 kGy. The samples were characterized by X-ray photoelectron spectroscopy and the surface composition (atomic%) showed a significant increase of oxygen content for the samples after irradiation. Also, the dispersion of the functionalized CNF in water was stable during months which may be a good indication that the functionalization process of CNF via ionizing radiation was successful

  7. Study of the time and space distribution of β+ emitters from 80MeV/u carbon ion beam irradiation on PMMA

    International Nuclear Information System (INIS)

    Agodi, C.; Bellini, F.; 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.

    2012-01-01

    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 and the on-line knowledge of the Bragg peak position is still a matter of research. A possible technique exploits the collinear 511keV photons produced by positrons annihilation from β + emitters created by the beam. This paper reports rate measurements of the 511keV photons emitted after the interactions of a 80MeV/u fully stripped carbon ion beam at the Laboratori Nazionali del Sud (LNS) of INFN, with a poly-methyl methacrylate target. The time evolution of the β + rate was parametrized and the dominance of 11 C emitters over the other species ( 13 N, 15 O, 14 O) was observed, measuring the fraction of carbon ions activating β + emitters to be (10.3±0.7)×10 -3 . The average depth in the PMMA of the positron annihilation from β + emitters was also measured, D β + =5.3±1.1mm, to be compared to the expected Bragg peak depth D Bragg =11.0±0.5mm obtained from simulations.

  8. Synthesis of n.c.a. PET-radiotracers with carbon-11

    International Nuclear Information System (INIS)

    Schirbel, A.

    1998-11-01

    Carbon-11 offers the unique possibility of authentic labelling of molecules as radioindicators for non invasive and quantitative determination of physiological functions via positron emission tomography (PET). Therefore, the goal of this thesis was to synthesize of different n.c.a. 11 C-labelled pharmaceuticals for in vivo distribution studies with PET. For the determination of the pharmacokinetics of [1- 11 C]acetate in porcine myocardium during prolonged ischemia, n.c.a. [1- 11 C]acetate was synthesized via carboxylation of methylmagnesium bromide with in target produced n.c.a. [ 11 C]CO 2 with a radiochemical yield (RCY) of 68 ± 7%. The fast (18 min) and reliable radiosynthesis allowed for repeated tracer administration at short intervals ( R c) in humans, [1- 11 C]acetylsalicylic acid, acetyl-[carboxy- 11 C]salicylic acid and [carboxy- 11 C]salicylic acid were prepared. N.c.a. [1- 11 C]acetylsalicylic acid was synthesized via the reaction of [1- 11 C]acetylchloride with salicylic acid salts. The use of the silver salt proved to be superior to the sodium salt and resulted in radiochemical yields of 32 ± 5%. Base-line (clean) separation of the labelled product was achieved using radio-HPLC. With regard to the preparation of n.c.a. [carboxy- 11 C]salicylic acid, several protected and unprotected phenol derivates were metallated and subsequently carboxylated using n.c.a. [ 11 C]CO 2 . Best results (87 ± 3% RCY) could be achieved with 2-(methoxymethoxy)-phenylmagnesium iodide as a precursor and subsequent quantitative cleavage of the MOM-group. Acetylation of n.c.a. [carboxy- 11 C]salicylic acid to acetyl-[carboxy- 11 C]salicylic acid was performed using acetylchloride in CH 2 Cl 2 with a radiochemical yield of 65 ± 4%. (orig.)

  9. Ohmic contact junction of carbon nanotubes fabricated by in situ electron beam deposition

    International Nuclear Information System (INIS)

    Wang, Y G; Wang, T H; Lin, X W; Dravid, V P

    2006-01-01

    We present experimental evidence of in situ fabrication of multi-walled carbon nanotube junctions via electron beam induced deposition. The tip-to-tip interconnection of the nanotubes involves the alignment of two nanotubes via a piezodriven nanomanipulator and nano-welding by electron beam deposition. Hydrocarbon contamination from the pump oil vapour of the vacuum system of the TEM chamber was used as the solder; this is superior to the already available metallic solders because its composition is identical to the carbon nanotube. The hydrocarbon deposition, with perfect wettability, on the nanotubes establishes strong mechanical binding between the two nanotubes to form an integrated structure. Consequently, the nanotubes cross-linked by the hydrocarbon solder produce good electrical and mechanical connections. The joint dimension was determined by the size of the electron beam, which results in a sound junction with well-defined geometry and the smallest junction size obtained so far. In situ electric measurement showed a linear current-voltage property for the multi-walled nanotube junction

  10. Chromosome aberrations induced by 135 MeV of carbon and neon beams by PRC

    International Nuclear Information System (INIS)

    Ohara, Hiroshi; Minamihisamatu, Masako; Kanai, Tatsuaki; Eguchi-Kasai, Kiyomi; Itsukaichi, Hiromi; Fukutsu, Kumiko; Yatagai, Fumio; Sato, Kohki.

    1993-01-01

    Radiation-induced chromosome aberration can be an indicator of the radiation lesions in irradiated cells. Many studies on chromosome aberration induced by X-ray and γ - ray have indicated that the dose response of the aberration can be fitted to a quadratic equation, Y = αD + βD 2 , and it becomes linear as the LET of beams increases. The main subject of this study was some quantification of chromosomal aberration induced by 135 MeV/n carbon and neon beams produced by the RRC, the operation of which increasingly became useful for the studies on heavy ion biology. The results will meet with some of the radiobiological features connected to the specific action of charged particles. The materials used, the experimental method and the results are reported. Four curves of the dose response for the production of dicentric and ring types of aberration induced by carbon and neon beams and four different dose average LETs are given. Aberration production rate became higher as LET increased. Chromosome aberration can be quantified as an indicator of radiation lesions in the case of high LET particle radiation. (K.I.)

  11. Mechanical Behavior of Steel Fiber-Reinforced Concrete Beams Bonded with External Carbon Fiber Sheets.

    Science.gov (United States)

    Gribniak, Viktor; Tamulenas, Vytautas; Ng, Pui-Lam; Arnautov, Aleksandr K; Gudonis, Eugenijus; Misiunaite, Ieva

    2017-06-17

    This study investigates the mechanical behavior of steel fiber-reinforced concrete (SFRC) beams internally reinforced with steel bars and externally bonded with carbon fiber-reinforced polymer (CFRP) sheets fixed by adhesive and hybrid jointing techniques. In particular, attention is paid to the load resistance and failure modes of composite beams. The steel fibers were used to avoiding the rip-off failure of the concrete cover. The CFRP sheets were fixed to the concrete surface by epoxy adhesive as well as combined with various configurations of small-diameter steel pins for mechanical fastening to form a hybrid connection. Such hybrid jointing techniques were found to be particularly advantageous in avoiding brittle debonding failure, by promoting progressive failure within the hybrid joints. The use of CFRP sheets was also effective in suppressing the localization of the discrete cracks. The development of the crack pattern was monitored using the digital image correlation method. As revealed from the image analyses, with an appropriate layout of the steel pins, brittle failure of the concrete-carbon fiber interface could be effectively prevented. Inverse analysis of the moment-curvature diagrams was conducted, and it was found that a simplified tension-stiffening model with a constant residual stress level at 90% of the strength of the SFRC is adequate for numerically simulating the deformation behavior of beams up to the debonding of the CFRP sheets.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    In this paper we present a method for single track coincidence measurements using two different track detector materials. We employed plastic and fluorescent nuclear track detectors (PNTDs and FNTDs) in the entrance channel of a monoenergetic carbon ion beam covering the therapeutic energy range from 80 to 425 MeV/u. About 99% of all primary particle tracks detected by both detectors were successfully matched, while 1% of the particles were only detected by the FNTDs because of their superior spatial resolution. We conclude that both PNTDs and FNTDs are suitable for clinical carbon beam dosimetry with a detection efficiency of at least 98.82% and 99.83% respectively, if irradiations are performed with low fluence in the entrance channel of the ion beam. The investigated method can be adapted to other nuclear track detectors and offers the possibility to characterize new track detector materials against well-known detectors. Further, by combining two detectors with a restricted working range in the presented way a hybrid-detector system can be created with an extended and optimized working range

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

    Science.gov (United States)

    Markwitz, A.; Kennedy, J.

    2017-10-01

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

  14. Occurrence of particle debris field during focused Ga ion beam milling of glassy carbon

    Energy Technology Data Exchange (ETDEWEB)

    Hu Qin [Centre for Industrial Photonics, Institute for Manufacturing, Department of Engineering, University of Cambridge, Alan Reece Building, 17 Charles Babbage Road, Cambridge, CB3 0FS (United Kingdom); O' Neill, William, E-mail: wo207@eng.cam.ac.uk [Centre for Industrial Photonics, Institute for Manufacturing, Department of Engineering, University of Cambridge, Alan Reece Building, 17 Charles Babbage Road, Cambridge, CB3 0FS (United Kingdom)

    2010-08-01

    To explore the machining characteristics of glassy carbon by focused ion beam (FIB), particles induced by FIB milling on glassy carbon have been studied in the current work. Nano-sized particles in the range of tens of nanometers up to 400 nm can often be found around the area subject to FIB milling. Two ion beam scanning modes - slow single scan and fast repetitive scan - have been tested. Fewer particles are found in single patterns milled in fast repetitive scan mode. For a group of test patterns milled in a sequence, it was found that a greater number of particles were deposited around sites machined early in the sequence. In situ EDX analysis of the particles showed that they were composed of C and Ga. The formation of particles is related to the debris generated at the surrounding areas, the low melting point of gallium used as FIB ion source and the high contact angle of gallium on glassy carbon induces de-wetting of Ga and the subsequent formation of Ga particles. Ultrasonic cleaning can remove over 98% of visible particles. The surface roughness (R{sub a}) of FIB milled areas after cleaning is less than 2 nm.

  15. Occurrence of particle debris field during focused Ga ion beam milling of glassy carbon

    International Nuclear Information System (INIS)

    Hu Qin; O'Neill, William

    2010-01-01

    To explore the machining characteristics of glassy carbon by focused ion beam (FIB), particles induced by FIB milling on glassy carbon have been studied in the current work. Nano-sized particles in the range of tens of nanometers up to 400 nm can often be found around the area subject to FIB milling. Two ion beam scanning modes - slow single scan and fast repetitive scan - have been tested. Fewer particles are found in single patterns milled in fast repetitive scan mode. For a group of test patterns milled in a sequence, it was found that a greater number of particles were deposited around sites machined early in the sequence. In situ EDX analysis of the particles showed that they were composed of C and Ga. The formation of particles is related to the debris generated at the surrounding areas, the low melting point of gallium used as FIB ion source and the high contact angle of gallium on glassy carbon induces de-wetting of Ga and the subsequent formation of Ga particles. Ultrasonic cleaning can remove over 98% of visible particles. The surface roughness (R a ) of FIB milled areas after cleaning is less than 2 nm.

  16. Source brightness and useful beam current of carbon nanotubes and other very small emitters

    International Nuclear Information System (INIS)

    Kruit, P.; Bezuijen, M.; Barth, J.E.

    2006-01-01

    The potential application of carbon nanotubes as electron sources in electron microscopes is analyzed. The resolution and probe current that can be obtained from a carbon nanotube emitter in a low-voltage scanning electron microscope are calculated and compared to the state of the art using Schottky electron sources. Many analytical equations for probe-size versus probe-current relations in different parameter regimes are obtained. It is shown that for most carbon nanotube emitters, the gun lens aberrations are larger than the emitters' virtual source size and thus restrict the microscope's performance. The result is that the advantages of the higher brightness of nanotube emitters are limited unless the angular emission current is increased over present day values or the gun lens aberrations are decreased. For some nanotubes with a closed cap, it is known that the emitted electron beam is coherent over the full emission cone. We argue that for such emitters the parameter ''brightness'' becomes meaningless. The influence of phase variations in the electron wave front emitted from such a nanotube emitter on the focusing of the electron beam is analyzed

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

    Science.gov (United States)

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

    2013-06-01

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

  18. One-nucleon transfer reactions induced by secondary beam of 11Be: study of the nuclear structure of the exotic nuclei 11Be and 10Li

    International Nuclear Information System (INIS)

    Pita, S.

    2000-09-01

    The structure of the neutron rich light nuclei 11 Be and 10 Li has been investigated by means of one nucleon transfer reactions. The experiments have been carried out at GANIL in inverse kinematics using 11 Be secondary beams. The 11 Be(p,d) 10 Be reaction bas been studied at 35.3 MeV/u. The 10 Be ejectiles were analyzed by the spectrometer SPEG, and coincident deuterons were detected in the position sensitive silicon detector CHARISSA. Transfer cross sections to 0 + 1 and 2 + 1 , states in 10 Be were measured up to θ CM = 16 deg. and compared to DWBA and CRC predictions. The effects of neutron-cure couplings on reaction form factors have been studied by solving coupled equations in the framework of a vibrational model. It is shown that the rate of core excitation 10 Be 2+ in the 11 Be gs wave function is overestimated by a standard analysis with form factors given by the usual Separation Energy prescription. The former model predicts a rate of core excitation of 16% and leads to theoretical cross sections which are in good agreement with the experimental data. The aim of the 11 Be(d, 3 He) 10 Li experiment, realized at 37 MeV/u, was to measure the distribution of the 2s neutron strength in the unbound nucleus 10 Li. The energy spectrum was deduced from the 3 He energy and angle measured by the silicon strip detector array MUST. An asymmetric peak is clearly observed near the threshold, with a maximum at -S n = 130 keV. This constitutes a direct proof of the inversion of 2s and 1p 1/2 shells in 10 Li, which was until now a controversial question in spite of many experimental efforts. On the other band the analysis of the 11 Be(d,t) 10 Be reaction studied in the same experiment confirms the results obtained in the 11 Be(p,d) 10 Be reaction concerning the 11 Be gs structure. This work shows the interest and feasibility of studies of the shell properties of exotic nuclei using transfer reactions induced by radioactive beams and constitutes the beginning of a program

  19. Carbon-11-labelling of a novel, trishomocubane-derived, high affinity and selectivity DAT ligand

    International Nuclear Information System (INIS)

    Dolle, F.; Le Helleix, St.; Peyronneau, M.A.; Saba, W.; Tournier, N.; Valette, H.; Banister, S.; Kassiou, M.

    2011-01-01

    Complete text of publication follows: Objectives: Parkinson's disease, schizophrenia, attention deficit disorder and drug abuse are related to abnormalities within the brain's dopaminergic system. The neuronal dopamine transporter (DAT) plays a key role in regulating the synaptic concentration of dopamine and thus dopamine neurotransmission in the brain. Since the DAT can be considered as a marker of the integrity and number of the presynaptic striatal dopamine-producing neurons, considerable efforts have been spent in recent years on the design and development of DAT-selective radioligands for use in Positron Emission Tomography (PET) studies. Notably, the tropane PE2I and its fluorinated analogue LBT-999 were identified as having high affinity and selectivity for the DAT over the norepinephrine transporter (NET) and the serotonin transporter (SERT). Besides tropanes, only a few bicyclic frameworks, e.g. bicyclo[2.2.2]octanes, have delivered compounds with high affinity for the DAT. Recently, novel poly-carbocyclic DAT ligands with selectivity over the NET and the SERT were reported. The lead compound of this series (1, N-methyl-N-(3-fluoro) benzyl-pentacyclo[5.4.0.0 2, 6 .0 3, 10 .0 5, 9 ] undec-8-ylamine, Ki = 1.2 nM, ≥ 8300-fold selectivity over NET and SERT) was selected as a potential candidate for imaging the DAT with PET and isotopically labelled with carbon-11 using [ 11 C]methyl triflate. Methods: The trishomocubane derivatives 1 (reference) and 2 (precursor for labelling with carbon-11) were prepared from commercially available Cookson's diketone in 6 and 7 steps, respectively. Carbon-11 labelling of 1 was performed using a TRACERLab FX-C Pro synthesizer (GEMS) and comprises (1) trapping at -10 C of [ 11 C]MeOTf in acetone (0.4 mL) containing the nor-derivative 2 (0.6-0.9 mg, free base) and aq. 3N NaOH (8 μL); (2) heating at 110 C for 2 min; (3) concentration to dryness and taking up the residue in 1.0 mL of the HPLC mobile phase; (4) purification

  20. Vibration of nonuniform carbon nanotube with attached mass via nonlocal Timoshenko beam theory

    International Nuclear Information System (INIS)

    Tang, Hai Li; Shen, Zhi Bin; Li, Dao Kui

    2014-01-01

    This paper studies the vibrational behavior of nonuniform single-walled carbon nanotube (SWCNT) carrying a nanoparticle. A nonuniform cantilever beam with a concentrated mass at the free end is analyzed according to the nonlocal Timoshenko beam theory. A governing equation of a nonuniform SWCNT with attached mass is established. The transfer function method incorporating with the perturbation method is utilized to obtain the resonant frequencies of a vibrating nonlocal cantilever-mass system. The effects of the nonlocal parameter, taper ratio and attached mass on the natural frequencies and frequency shifts are discussed. Obtained results indicate that the sensitivity of the frequency shifts on the attached mass increases when the length-to-diameter ratio decreases. Tapered SWCNT possesses higher fundamental frequencies if the taper ratio becomes larger.

  1. Carbon filament beam profile monitor for high energy proton-antiproton storage rings

    International Nuclear Information System (INIS)

    Evans, L.R.; Shafer, R.E.

    1979-01-01

    The measurement of the evolution of the transverse profile of the stored beams in high energy proton storage rings such as the p-anti p colliders at CERN and at FNAL is of considerable importance. In the present note, a simple monitor is discussed which will allow almost non-destructive measurement of the profile of each individual proton and antiproton bunch separately. It is based on the flying wire technique first used at CEA and more recently at the CPS. A fine carbon filament is passed quickly through the beam, acting as a target for secondary particle production. The flux of secondary particles is measured by two scintillator telescopes, one for protons and one for antiprotons, having an angular acceptance between 30 and 100 mrad. Measurements of secondary particle production performed at FNAL in this angular range show that a very respectable flux can be expected

  2. Behavior of Insulated Carbon-FRP-Strengthened RC Beams Exposed to Fire

    Science.gov (United States)

    Sayin, B.

    2014-09-01

    There are two main approaches to improving the fire resistance of fiber-reinforced polymer (FRP) systems. While the most common method is to protect or insulate the FRP system, an other way is to use fibers and resins with a better fire performance. This paper presents a numerical investigation into the five protection behavior of insulated carbon-fiber-reinforced-polymer (CFRP)-strengthened reinforced concrete (RC) beams. The effects of external loading and thermal expansion of materials at elevated temperatures are taken into consideration in a finite-element model. The validity of the numerical model is demonstrated with results from an existing experimental study on insulated CFRP-strengthened RC beams. Conclusions of this investigation are employed to predict the structural behavior of CFRP-strengthened concrete structures.

  3. In silico carbon molecular beam epitaxial growth of graphene on the h-BN substrate: carbon source effect on van der Waals epitaxy

    Science.gov (United States)

    Lee, Jonghoon; Varshney, Vikas; Park, Jeongho; Farmer, Barry L.; Roy, Ajit K.

    2016-05-01

    Against the presumption that hexagonal boron-nitride (h-BN) should provide an ideal substrate for van der Waals (vdW) epitaxy to grow high quality graphene films, carbon molecular beam epitaxy (CMBE) techniques using solid carbon sublimation have reported relatively poor quality of the graphene. In this article, the CMBE growth of graphene on the h-BN substrate is numerically studied in order to identify the effect of the carbon source on the quality of the graphene film. The carbon molecular beam generated by the sublimation of solid carbon source materials such as graphite and glassy carbon is mostly composed of atomic carbon, carbon dimers and carbon trimers. Therefore, the graphene film growth becomes a complex process involving various deposition characteristics of a multitude of carbon entities. Based on the study of surface adsorption and film growth characteristics of these three major carbon entities comprising graphite vapour, we report that carbon trimers convey strong traits of vdW epitaxy prone to high quality graphene growth, while atomic carbon deposition is a surface-reaction limited process accompanied by strong chemisorption. The vdW epitaxial behaviour of carbon trimers is found to be substantial enough to nucleate and develop into graphene like planar films within a nanosecond of high flux growth simulation, while reactive atomic carbons tend to impair the structural integrity of the crystalline h-BN substrate upon deposition to form an amorphous interface between the substrate and the growing carbon film. The content of reactive atomic carbons in the molecular beam is suspected to be the primary cause of low quality graphene reported in the literature. A possible optimization of the molecular beam composition towards the synthesis of better quality graphene films is suggested.Against the presumption that hexagonal boron-nitride (h-BN) should provide an ideal substrate for van der Waals (vdW) epitaxy to grow high quality graphene films, carbon

  4. Quantum beats study of the 4He+ beam-carbon foil interaction

    International Nuclear Information System (INIS)

    Denis, A.; Desesquelles, J.

    1979-01-01

    Excitation cross-sections are deduced from the analysis of quantum beats in an electric field for an 4 He + (n=4) ion beam scattering through a thin carbon foil. The population distribution obtained at 1 MeV for 4S, 4P, 4D and 4F levels is in good agreement with a second-order Born approximation calculation of the electronic capture He ++ +C→He + (n=4) + C + . The alignment is found to be negative for P, D and F levels. The coherences Δl=+-1 have been measured, for amplitudes and phases [fr

  5. Noninvasive assessment of canine myocardial oxidative metabolism with carbon-11 acetate and positron emission tomography

    International Nuclear Information System (INIS)

    Brown, M.A.; Myears, D.W.; Bergmann, S.R.

    1988-01-01

    Noninvasive quantification of regional myocardial metabolism would be highly desirable to evaluate pathogenetic mechanisms of heart disease and their response to therapy. It was previously demonstrated that the metabolism of radiolabeled acetate, a readily utilized myocardial substrate predominantly metabolized to carbon dioxide (CO2) by way of the tricarboxylic acid cycle, provides a good index of oxidative metabolism in isolated perfused rabbit hearts because of tight coupling between the tricarboxylic acid cycle and oxidative phosphorylation. In the present study, in a prelude to human studies, the relation between myocardial clearance of carbon-11 (11C)-labeled acetate and myocardial oxygen consumption was characterized in eight intact dogs using positron emission tomography. Anesthetized dogs were studied during baseline conditions and again during either high or low work states induced pharmacologically. High myocardial extraction and rapid blood clearance of tracer yielded myocardial images of excellent quality. The turnover (clearance) of 11C radioactivity from the myocardium was biexponential with the mean half-time of the dominant rapid phase averaging 5.4 +/- 2.2, 2.8 +/- 1.3 and 11.1 +/- 1.3 min in control, high and low work load studies, respectively. No significant difference was found between the rate of clearance of 11C radioactivity from the myocardium measured noninvasively with positron emission tomography and the myocardial efflux of 11CO2 measured directly from the coronary sinus. The rate of clearance of the 11C radioactivity from the heart correlated closely with myocardial oxygen consumption (r = 0.90, p less than 0.001) as well as with the rate-pressure product (r = 0.95, p less than 0.001). Hence, the rate of oxidation of 11C-acetate can be determined noninvasively with positron emission tomography, providing a quantitative index of oxidative metabolism under diverse conditions

  6. Geant4 simulation of clinical proton and carbon ion beams for the treatment of ocular melanomas with the full 3-D pencil beam scanning system

    Energy Technology Data Exchange (ETDEWEB)

    Farina, Edoardo; Riccardi, Cristina; Rimoldi, Adele; Tamborini, Aurora [University of Pavia and the INFN section of Pavia, via Bassi 6, 27100 Pavia (Italy); Piersimoni, Pierluigi [Division of Radiation Research, Loma Linda University, Loma Linda, CA 92354 (United States); Ciocca, Mario [Medical Physics Unit, CNAO Foundation, Strada Campeggi 53, 27100 Pavia (Italy)

    2015-07-01

    This work investigates the possibility to use carbon ion beams delivered with active scanning modality, for the treatment of ocular melanomas at the Centro Nazionale di Adroterapia Oncologica (CNAO) in Pavia. The radiotherapy with carbon ions offers many advantages with respect to the radiotherapy with protons or photons, such as a higher relative radio-biological effectiveness (RBE) and a dose release better localized to the tumor. The Monte Carlo (MC) Geant4 10.00 patch-03 toolkit is used to reproduce the complete CNAO extraction beam line, including all the active and passive components characterizing it. The simulation of proton and carbon ion beams and radiation scanned field is validated against CNAO experimental data. For the irradiation study of the ocular melanoma an eye-detector, representing a model of a human eye, is implemented in the simulation. Each element of the eye is reproduced with its chemical and physical properties. Inside the eye-detector a realistic tumor volume is placed and used as the irradiation target. A comparison between protons and carbon ions eye irradiations allows to study possible treatment benefits if carbon ions are used instead of protons. (authors)

  7. Three-dimensional ultrashort optical Airy beams in an inhomogeneous medium with carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, Alexander V., E-mail: alex.zhukov@outlook.sg [Singapore University of Technology & Design, 8 Somapah Road, 487372 Singapore (Singapore); Bouffanais, Roland [Singapore University of Technology & Design, 8 Somapah Road, 487372 Singapore (Singapore); Belonenko, Mikhail B. [Laboratory of Nanotechnology, Volgograd Institute of Business, 400048 Volgograd (Russian Federation); Volgograd State University, 400062 Volgograd (Russian Federation); Dvuzhilov, Ilya S. [Volgograd State University, 400062 Volgograd (Russian Federation)

    2017-03-11

    In this Letter, we consider the problem of the dynamics of propagation of three-dimensional optical pulses (a.k.a. light bullets) with an Airy profile through a heterogeneous environment of carbon nanotubes. We show numerically that such beams exhibit sustained and stable propagation. Moreover, we demonstrate that by varying the density modulation period of the carbon nanotubes one can indirectly control the pulse velocity, which is a particularly valuable feature for the design and manufacturing of novel pulse delay devices. - Highlights: • Propagation of Airy pulses in CNTs with modulated density. • Light bullets propagate stably. • Influence of Airy parameter is revealed. • Modulation period results in an increase of the pulse velocity.

  8. Treatment of industrial effluents using electron beam accelerator and adsorption with activated carbon. A comparative study

    International Nuclear Information System (INIS)

    Las Casas, Alexandre

    2004-01-01

    Several methods are used In the pollutant removal from Industrial and domestic wastewater. However when the degradation of toxic organic pollutants, mainly the recalcitrant is objectified, the conventional treatments usually do not meet the desirable performance in the elimination or decrease the impact when the effluent are released to the environment what takes to the research of alternative methods that seek the improvement of the efficiency of the wastewater treatment systems jointly employees or separately. This work presents a study of degradation/removal of pollutants organic compounds comparing two methods using radiation from industrial electron beam and granular activated carbon (GAC). The removal efficiency of the pollutants was evaluated and it was verified that the efficiency of adsorption with activated carbon is similar to the radiation method. The obtained results allowed to evaluated the relative costs of these methods. (author)

  9. Field performance of timber bridges. 11, Spearfish Creek stress-laminated box-beam bridge

    Science.gov (United States)

    J. P. Wacker; M. A. Ritter; K. Stanfill-McMillan

    The Spearfish Creek bridge was constructed in 1992 in Spearfish, South Dakota. It is a single-span, stress-laminated, box-beam superstructure. Performance of the bridge is being monitored for 5 years, beginning at installation. This report summarizes results for the first 3-1/2 years of monitoring and includes information on the design, construction, and field...

  10. Study of the time and space distribution of {beta}{sup +} emitters from 80MeV/u carbon ion beam irradiation on PMMA

    Energy Technology Data Exchange (ETDEWEB)

    Agodi, C. [Laboratori Nazionali del Sud dell' INFN, Catania (Italy); Bellini, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Cirrone, G.A.P. [Laboratori Nazionali del Sud dell' INFN, Catania (Italy); Collamati, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Cuttone, G. [Laboratori Nazionali del Sud dell' INFN, Catania (Italy); De Lucia, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); De Napoli, M. [Laboratori Nazionali del Sud dell' INFN, Catania (Italy); Di Domenico, A.; Faccini, R.; Ferroni, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Fiore, S. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); Gauzzi, P. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Iarocci, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Dipartimento di Scienze di Base e Applicate per l' Ingegneria, Sapienza Universita di Roma, Roma (Italy); Marafini, M., E-mail: michela.marafini@roma1.infn.it [Museo Storico della Fisica e Centro Studi e Ricerche ' E. Fermi' , Roma (Italy); Mattei, I. [Dipartimento di Fisica, Roma Tre Universita di Roma, Roma (Italy); Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Paoloni, A. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); and others

    2012-07-15

    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 and the on-line knowledge of the Bragg peak position is still a matter of research. A possible technique exploits the collinear 511keV photons produced by positrons annihilation from {beta}{sup +} emitters created by the beam. This paper reports rate measurements of the 511keV photons emitted after the interactions of a 80MeV/u fully stripped carbon ion beam at the Laboratori Nazionali del Sud (LNS) of INFN, with a poly-methyl methacrylate target. The time evolution of the {beta}{sup +} rate was parametrized and the dominance of {sup 11}C emitters over the other species ({sup 13}N, {sup 15}O, {sup 14}O) was observed, measuring the fraction of carbon ions activating {beta}{sup +} emitters to be (10.3{+-}0.7) Multiplication-Sign 10{sup -3}. The average depth in the PMMA of the positron annihilation from {beta}{sup +} emitters was also measured, D{sub {beta}{sup +}}=5.3{+-}1.1mm, to be compared to the expected Bragg peak depth D{sub Bragg}=11.0{+-}0.5mm obtained from simulations.

  11. The CBS-The Most Cost Effective and High Performance Carbon Beam Source Dedicated for a New Generation Cancer Therapy

    CERN Document Server

    Kumada, Masayuki; Leivichev, E B; Parkhomchuk, Vasily; Podgorny, Fedor; Rastigeev, Sergey; Reva, Vladimir B; Skrinsky, Aleksander Nikolayevich; Vostrikov, Vladimir

    2005-01-01

    A Carbon ion beam is a superior tool to x-rays or a proton beam in both physical and biological doses in treating a cancer. A Carbon beam has an advantage in treating radiation resistant and deep-seated tumors. Its radiological effect is of a mitotic independent nature. These features improve hypofractionation, typically reducing the number of irradiations per patient from 35 to a few. It has been shown that a superior QOL(Quality Of Life) therapy is possible by a carbon beam.The only drawback is its high cost. Nevertheless, tens of Prefectures and organizations are eagerly considering the possibility of having a carbon ion therapy facility in Japan. Germany, Austria, Italy, China, Taiwan and Korea also desire to have one.A carbon beam accelerator of moderate cost is about 100 Million USD. With the "CBS" design philosophy, which will be described in this paper, the cost could be factor of 2 or 3 less, while improving its performance more than standard designs. Novel extraction techniques, a new approach to a ...

  12. Preparation of carbon-11 labelled phenylalanine and phenylglycine by a new amino acid synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Vaalburg, W; Beerling-van der Molen, H D; Reiffers, S; Rijskamp, A; Woldring, M G; Wynberg, H [Academic Hospital, Groningen (Netherlands). Central Isotope Lab.

    1976-03-01

    Of the cyclotron-produced short-lived isotopes carbon-11 (tsub(1/2) = 20.4 min;..beta../sup +/) is one of the most promising as label for radiopharmaceuticals. To prepare /sup 11/C-labelled amino acids for evaluation as pancreas scanning agents a new rapid amino acid synthesis was developed. The method is based on the carboxylation of ..cap alpha..-lithioisocyanides with /sup 11/CO/sub 2/, followed by hydrolysis of the intermediate reaction product to the desired amino acid. By this method DL-..cap alpha..-phenylalanine-1-/sup 11/C and DL-..cap alpha..-phenylglycine-1-/sup 11/C were prepared. The precursor /sup 11/CO/sub 2/ was produced via the /sup 14/N(p,..cap alpha..)/sup 11/C reaction by bombardment of a flow of nitrogen gas mixed with 0.1% 0/sub 2/ with 20 MeV protons. The target system is described.

  13. Isotope separation of relativistic projectile fragments as well as cross section measurements on 8,9,11Li secondary beams

    International Nuclear Information System (INIS)

    Blank, B.

    1991-06-01

    In the framework of this thesis the method of the 'momentum-loss achromate' was for the first time tested at relativistic energies. This experiment is presented in chapter 2 of the thesis. In a second experiment the method was then used, in order to make secondary beams of 8,9,11 Li available. With these secondary beams cross section measurements were performed, from which beside information on the nuclear radii of these nuclei also further information on the internal structure of the lithium isotopes can be derived. This experiment is described in chapter 3 of the thesis. In the framework of these two experiments for the applied heavy ions energy-loss measurements were performed. The results of these measurements are presented in chapter 4. (orig.) [de

  14. Some examples of the use of carbon 11-labelled molecules in medical research

    International Nuclear Information System (INIS)

    Comar, D.; Berger, G.; Mestelan, G.

    1976-01-01

    If a radioelement is to be useful for medical diagnosis it must: be an indicator of a normal or pathological biological process; have a half-life consistent with the duration of the biological phenomenon to be observed; emit a suitable radiation. Carbon 11 is one of the radionuclides which best satisfies these different requirements. It is shown how this radioelement, of 20-minute half-life, may be incorporated into psychotropic drugs and biologically useful molecules with enough speed to have an available radioactivity adequate for diagnostic examinations. Two examples are described, one concerning the metabolism of a neuroleptic, chlorpromazine-11C, the other the passage of methionine- 11 C through the blood brain barrier during a congenital disease, phenylketonuria [fr

  15. Dosimetric properties of Gafchromic (registered) EBT films in medical carbon ion beams

    International Nuclear Information System (INIS)

    MartisIkova, Maria; Jaekel, Oliver

    2010-01-01

    High spatial resolution is desired for dosimetrical verification of patient plans for radiotherapy treatments employing scanned ion beams. This is provided by Gafchromic EBT film, the ancestor of currently available EBT2 films. In this contribution, dosimetric properties of EBT films were investigated. Measurements of depth response were performed for monoenergetic fields (250 MeV/u) for different ion fluences as well as for an energy-modulated spread-out Bragg peak of 5 x 5 x 5 cm 3 in 10 cm depth. The films were positioned perpendicular to the incoming carbon ion beams. The observed quenching of the response relative to the same dose of photons was quantified by the relative efficiency. In monenenergetic beams, a relative efficiency of about 0.73 was found in the plateau, 0.4 in the peak and 0.55 in the tail region. No dependence of the relative efficiency on the ion fluence was observed well beyond the clinically used levels. This gives a constant peak to plateau ratio, which is about 1.8 times lower than that for the delivered dose. In the spread-out Bragg peak, the relative efficiency was found to decrease from 0.64 to 0.54 toward the distal end. Thus when aiming for a prediction of the film response in mixed ion beams, the efficiency of the film has to be parametrized as a function of the ion type and energy over the whole ion spectrum. In addition, the relative water-equivalent range of EBT films was measured here to be 1.291 ± 0.015.

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

    International Nuclear Information System (INIS)

    Chapman, J.D.; Blakely, E.A.; Smith, K.C.; Urtasun, R.C.; Lyman, J.T.; Tobias, C.A.

    1978-01-01

    Chinese hamster (V-79) and human kidney (T-1) cells were irradiated in stirred suspensions placed at various positions in the plateau and extended Bragg peak of a 400-MeV/amu carbon ion beam. The range of the ions was modulated by a lead (translational) ridge filter and a brass (spiral) ridge filter designed to produce extended peaks of approximately 4 and 10 cm, respectively. Stationary-phase and G 1 -phase populations of Chinese hamster cells were found to have different absolute radiosensitivities which, in turn, were different from that of asynchronous human kidney cells. The increase in relative biological effectiveness (RBE) observed as carbon ions were slowed down and stopped in water was similar for the three cell populations at doses greater than 400 rad. At lower doses the RBE was greater for the hamster cell populations than for the human kidney cells. The gain in RBE (at the 50% survival level) between the plateaus and the middle region of the extended peaks was approximately 2.0 and 1.7 for the 4- and 10-cm extended peaks, respectively. Oxygen enhancement ratios (OER) were determined at the 10% survival levels with stationary-phase populations of hamster cells. Values of 2.8, 2.65, and 1.65 were obtained for the OER of 220-kV x rays, plateau carbon, and the middle region of the 4-cm carbon peak, respectively. Across the 10-cm carbon peak the OER was found to vary between values of 2.4 to 1.55 from the proximal to distal positions

  17. 11

    African Journals Online (AJOL)

    a routine working week. Special ... day of the working week and retested after finishing work on ... 4. 3. Med. 11,8. 12. -ye. 0. 5. 5. Med. 27,3. 107. -ye. 2. 6. 6. Med. 17,1. 80. -Ye. 0. 7. 3 .... present hours after first exposure (e.g. at night), it is also.

  18. 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.

  19. Nuclear reactions with 11C and 14O radioactive ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Fanqing [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F

  20. Development of carbon-11 labeled acryl amides for selective PET imaging of active tissue transglutaminase.

    Science.gov (United States)

    van der Wildt, Berend; Wilhelmus, Micha M M; Bijkerk, Jonne; Haveman, Lizeth Y F; Kooijman, Esther J M; Schuit, Robert C; Bol, John G J M; Jongenelen, Cornelis A M; Lammertsma, Adriaan A; Drukarch, Benjamin; Windhorst, Albert D

    2016-04-01

    Tissue transglutaminase (TG2) is a ubiquitously expressed enzyme capable of forming metabolically and mechanically stable crosslinks between the γ-carboxamide of a glutamine acyl-acceptor substrate and the ε-amino functionality of a lysine acyl-donor substrate resulting in protein oligomers. High TG2 crosslinking activity has been implicated in the pathogenesis of various diseases including celiac disease, cancer and fibrotic and neurodegenerative diseases. Development of a PET tracer specific for active TG2 provides a novel tool to further investigate TG2 biology in vivo in disease states. Recently, potent irreversible active site TG2 inhibitors carrying an acrylamide warhead were synthesized and pharmacologically characterized. Three of these inhibitors, compound 1, 2 and 3, were successfully radiolabeled with carbon-11 on the acrylamide carbonyl position using a palladium mediated [(11)C]CO aminocarbonylation reaction. Ex vivo biodistribution and plasma stability were evaluated in healthy Wistar rats. Autoradiography was performed on MDA-MB-231 tumor sections. [(11)C]1, -2 and -3 were obtained in decay corrected radiochemical yields of 38-55%. Biodistribution showed low uptake in peripheral tissues, with the exception of liver and kidney. Low brain uptake of <0.05% ID/g was observed. Blood plasma analysis demonstrated that [(11)C]1 and [(11)C]2 were rapidly metabolized, whereas [(11)C]3 was metabolized at a more moderate rate (63.2 ± 6.8 and 28.7 ± 10.8% intact tracer after 15 and 45 min, respectively). Autoradiography with [(11)C]3 on MDA-MB-231 tumor sections showed selective and specific binding of the radiotracer to the active state of TG2. Taken together, these results identify [(11)C]3 as the most promising of the three compounds tested for development as PET radiotracer for the in vivo investigation of TG2 activity. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Imaging the interphase of carbon fiber composites using transmission electron microscopy: Preparations by focused ion beam, ion beam etching, and ultramicrotomy

    Directory of Open Access Journals (Sweden)

    Wu Qing

    2015-10-01

    Full Text Available Three sample preparation techniques, focused ion beam (FIB, ion beam (IB etching, and ultramicrotomy (UM were used in comparison to analyze the interphase of carbon fiber/epoxy composites using transmission electron microscopy. An intact interphase with a relatively uniform thickness was obtained by FIB, and detailed chemical analysis of the interphase was investigated by electron energy loss spectroscopy. It shows that the interphase region is 200 nm wide with an increasing oxygen-to-carbon ratio from 10% to 19% and an almost constant nitrogen-to-carbon ratio of about 3%. However, gallium implantation of FIB tends to hinder fine structure analysis of the interphase. For IB etching, the interphase region is observed with transition morphology from amorphous resin to nano-crystalline carbon fiber, but the uneven sample thickness brings difficulty for quantitative chemical analysis. Moreover, UM tends to cause damage and/or deformation on the interphase. These results are meaningful for in-depth understanding on the interphase characteristic of carbon fiber composites.

  2. Integration and evaluation of automated Monte Carlo simulations in the clinical practice of scanned proton and carbon ion beam therapy.

    Science.gov (United States)

    Bauer, J; Sommerer, F; Mairani, A; Unholtz, D; Farook, R; Handrack, J; Frey, K; Marcelos, T; Tessonnier, T; Ecker, S; Ackermann, B; Ellerbrock, M; Debus, J; Parodi, K

    2014-08-21

    Monte Carlo (MC) simulations of beam interaction and transport in matter are increasingly considered as essential tools to support several aspects of radiation therapy. Despite the vast application of MC to photon therapy and scattered proton therapy, clinical experience in scanned ion beam therapy is still scarce. This is especially the case for ions heavier than protons, which pose additional issues like nuclear fragmentation and varying biological effectiveness. In this work, we present the evaluation of a dedicated framework which has been developed at the Heidelberg Ion Beam Therapy Center to provide automated FLUKA MC simulations of clinical patient treatments with scanned proton and carbon ion beams. Investigations on the number of transported primaries and the dimension of the geometry and scoring grids have been performed for a representative class of patient cases in order to provide recommendations on the simulation settings, showing that recommendations derived from the experience in proton therapy cannot be directly translated to the case of carbon ion beams. The MC results with the optimized settings have been compared to the calculations of the analytical treatment planning system (TPS), showing that regardless of the consistency of the two systems (in terms of beam model in water and range calculation in different materials) relevant differences can be found in dosimetric quantities and range, especially in the case of heterogeneous and deep seated treatment sites depending on the ion beam species and energies, homogeneity of the traversed tissue and size of the treated volume. The analysis of typical TPS speed-up approximations highlighted effects which deserve accurate treatment, in contrast to adequate beam model simplifications for scanned ion beam therapy. In terms of biological dose calculations, the investigation of the mixed field components in realistic anatomical situations confirmed the findings of previous groups so far reported only in

  3. P-type doping of semipolar GaN(11 anti 22) by plasma-assisted molecular-beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Das, A.; Lahourcade, L. [Equipe Mixte CEA-CNRS, Nanophysique et Semiconducteurs, CEA-Grenoble, INAC/SP2M, Grenoble (France); Pernot, J. [Institut Neel, CNRS et Universite Joseph Fourier, Grenoble (France); Valdueza-Felip, S. [Equipe Mixte CEA-CNRS, Nanophysique et Semiconducteurs, CEA-Grenoble, INAC/SP2M, Grenoble (France); Dept. Electronica, Escuela Politecnica, Universidad de Alcala, Alcala de Henares, Madrid (Spain); Ruterana, P. [CIMAP, UMR6252, CNRS-ENSICAEN-CEA-UCBN, Caen (France); Laufer, A.; Eickhoff, M. [I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen (Germany); Monroy, E.

    2010-07-15

    We report the effect of Mg doping on the growth kinetics of semipolar GaN(11-22) synthesized by plasma-assisted molecular-beam epitaxy. Mg tends to segregate on the surface, inhibiting the formation of the self-regulated Ga film which is used as a surfactant for the growth of undoped and Si-doped GaN(11-22). As a result, the growth widow is reduced for Mg doped layers, and we observe a certain deterioration of the surface morphology. In spite of this difficulties, homogenous Mg incorporation is achieved and layers display p -type conductivity for Mg atomic concentration higher than 7 x 10{sup 18} cm{sup -3}. Microscopy studies show no evidence of the pyramidal defects or polarity inversion domains found in Mg-doped GaN(0001). (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Isochoric PVTx measurements for the carbon dioxide + 1,1-difluoroethane binary system

    OpenAIRE

    Di Nicola, G.; Polonara, F.; Santori, G.; Stryjek, R.

    2007-01-01

    PVTx measurements for carbon dioxide (CO, R744) + 1,1-difluoroethane (CHCHF, R152a) for both the two-phase and the superheated vapor regions are presented. The measurements were taken with a constant volume apparatus at temperatures ranging from (223 to 343) K and pressures from (60 to 3890) kPa along eight isochores. The data obtained in the two-phase region were used to derive vapor-liquid equilibrium (VLB) parameters using a flash method with the Carnahan-Starling-De Santis equation of sta...

  5. Preclinical evaluation of carbon-11 and fluorine-18 sulfonamide derivatives for in vivo radiolabeling of erythrocytes

    OpenAIRE

    Gheysens, Olivier; Akurathi, Vamsidhar; Chekol, Rufael; Dresselaers, Tom; Celen, Sofie; Koole, Michel; Dauwe, Dieter; Cleynhens, Bernard J; Claus, Piet; Janssens, Stefan; Verbruggen, Alfons M; Nuyts, Johan; Himmelreich, Uwe; Bormans, Guy M

    2013-01-01

    Background To date, few PET tracers for in vivo labeling of red blood cells (RBCs) are available. In this study, we report the radiosynthesis and in vitro and in vivo evaluation of 11C and 18F sulfonamide derivatives targeting carbonic anhydrase II (CA II), a metallo-enzyme expressed in RBCs, as potential blood pool tracers. A proof-of-concept in vivo imaging study was performed to demonstrate the feasibility to assess cardiac function and volumes using electrocardiogram (ECG)-gated positron ...

  6. Synthesis of high specific activity carbon-11 labeled tracers for neuroreceptor studies

    International Nuclear Information System (INIS)

    Dannals, R.F.; Ravert, H.T.; Wilson, A.A.; Wagner, H.N. Jr; Johns Hopkins Medical Institutions, Baltimore, MD

    1989-01-01

    The use of short-lived positron-emitting radiotracers together with positron emission tomography (PET) has allowed scientists to acquire previously inaccessible information regarding problems in physiology, biochemistry, and pharmacology in the living human body. In the past five years, successes in the application of PET to the non-invasive determination of the spatial distribution and regional concentration of a variety of neurotransmitter binding sites within the living brain often followed the successful selections and syntheses of appropriately radiolabeled ligands. This presentation concentrates on the synthesis of these high specific activity radiotracers for neuroreceptor PET studies labeled specifically with carbon-11. (author). 15 refs.; 1 fig

  7. Reduced myocardial carbon-11 hydroxyephedrine retention is associated with poor prognosis in chronic heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Pietilae, M.; Ukkonen, H. [Dept. of Medicine, Turku University Central Hospital (Finland); Turku PET Centre, Turku (Finland); Malminiemi, K. [Dept. of Clinical Chemistry, Tampere University Hospital (Finland); Saraste, M. [Dept. of Clinical Physiology, Turku University Central Hospital (Finland); Naagren, K.; Lehikoinen, P. [Turku PET Centre, Turku (Finland); Voipio-Pulkki, L.-M. [Dept. of Medicine, Turku University Central Hospital (Finland); Dept. of Medicine, Helsinki University Central Hospital (Finland)

    2001-03-01

    Abnormalities of the autonomic nervous system are known to be of prognostic significance in chronic heart failure (CHF). The prognostic value of positron emission tomography (PET) imaging of cardiac autonomic innervation in CHF has not been explored previously. We retrospectively studied the survival data of 46 NYHA class II-III CHF patients (mean LVEF 35%{+-}8%) who had undergone carbon-11 hydroxyephedrine ({sup 11}C-HED) studies at the Turku PET Centre between August 1992 and March 1996. The origin of CHF was dilated cardiomyopathy in 13 of the 46 patients and coronary artery disease with at least one prior myocardial infarction in the remaining 33. Data on causes of death and heart transplantation were collected, and the statistically significant predictors of prognosis were analysed using Cox's proportional hazards regression. During the mean follow-up period of 55{+-}19 months, 11 deaths occurred and two patients underwent heart transplantation successfully. Eleven end-points were classified as cardiac (nine sudden cardiac deaths and two deaths due to progressive heart failure) and two as non-cardiac. When divided into two groups based on the median of {sup 11}C-HED retention (mean 0.184{+-}0.061, median 0.183), eight end-points (death or cardiac transplantation) were reached in the group with {sup 11}C-HED retention below the median and three in the group with {sup 11}C-HED retention above the median (P<0.02). In proportional hazards regression analysis, only peak oxygen uptake (peak VO{sub 2}), left ventricular end-diastolic volume and HED retention were found to be statistically significant. It is concluded that {sup 11}C-HED PET provides independent prognostic information in patients with CHF. (orig.)

  8. Reduced myocardial carbon-11 hydroxyephedrine retention is associated with poor prognosis in chronic heart failure

    International Nuclear Information System (INIS)

    Pietilae, M.; Ukkonen, H.; Malminiemi, K.; Saraste, M.; Naagren, K.; Lehikoinen, P.; Voipio-Pulkki, L.-M.

    2001-01-01

    Abnormalities of the autonomic nervous system are known to be of prognostic significance in chronic heart failure (CHF). The prognostic value of positron emission tomography (PET) imaging of cardiac autonomic innervation in CHF has not been explored previously. We retrospectively studied the survival data of 46 NYHA class II-III CHF patients (mean LVEF 35%±8%) who had undergone carbon-11 hydroxyephedrine ( 11 C-HED) studies at the Turku PET Centre between August 1992 and March 1996. The origin of CHF was dilated cardiomyopathy in 13 of the 46 patients and coronary artery disease with at least one prior myocardial infarction in the remaining 33. Data on causes of death and heart transplantation were collected, and the statistically significant predictors of prognosis were analysed using Cox's proportional hazards regression. During the mean follow-up period of 55±19 months, 11 deaths occurred and two patients underwent heart transplantation successfully. Eleven end-points were classified as cardiac (nine sudden cardiac deaths and two deaths due to progressive heart failure) and two as non-cardiac. When divided into two groups based on the median of 11 C-HED retention (mean 0.184±0.061, median 0.183), eight end-points (death or cardiac transplantation) were reached in the group with 11 C-HED retention below the median and three in the group with 11 C-HED retention above the median (P 2 ), left ventricular end-diastolic volume and HED retention were found to be statistically significant. It is concluded that 11 C-HED PET provides independent prognostic information in patients with CHF. (orig.)

  9. Beam Tests of Diamond-Like Carbon Coating for Mitigation of Electron Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey [Fermilab; Backfish, Michael [Fermilab; Kato, Shigeki [KEK, Tsukuba; Tan, Cheng-Yang [Fermilab; Zwaska, Robert [Fermilab

    2017-05-01

    Electron cloud beam instabilities are an important consideration in virtually all high-energy particle accelerators and could pose a formidable challenge to forthcoming high-intensity accelerator upgrades. Our results evaluate the efficacy of a diamond-like carbon (DLC) coating for the mitigation of electron in the Fermilab Main Injector. The interior surface of the beampipe conditions in response to electron bombardment from the electron cloud and we track the change in electron cloud flux over time in the DLC coated beampipe and uncoated stainless steel beampipe. The electron flux is measured by retarding field analyzers placed in a field-free region of the Main Injector. We find the DLC coating reduces the electron cloud signal to roughly 2\\% of that measured in the uncoated stainless steel beampipe.

  10. Beam-foil study of neon in the EUV with foils of carbon, silver and gold

    International Nuclear Information System (INIS)

    Demarest, J.A.; Watson, R.L.; Texas A and M Univ., College Station

    1988-01-01

    A beam-foil study of 40 MeV neon was conducted in the EUV with a 1-meter grazing incidence spectrometer configured with a position sensitive microchannel plate detector. A number of new lines of Ne IX, mainly from transitions to n = 3 levels, were detected in the wavelength region covering 50-350 A. Comparison of the spectra obtained using the different foils revealed that the average charge state of the neon projectiles was nearly one unit higher with carbon than with either of the two metals. Measurements of line intensities versus distance from the foils showed that cascade contributions were greatly reduced for the metals. It was also found that n = 3 states of low l were overpopulated relative to a statistical distribution, irrespective of the foil material. (orig.)

  11. The effect of carbon beam on the survival of hematopoietic stem cells in irradiated mice

    International Nuclear Information System (INIS)

    Tsuboi, Atsushi; Kojima, Eiichi; Tanaka, Kaoru

    1993-01-01

    The new cyclotron for heavy ion radiotherapy will be completed in the very near future at NIRS. High LET radiations having different qualities are known to produce differences in biological effectiveness. It is necessary to determine the biological effectiveness of this new radiation source in both normal and tumor tissues. In this paper, the effects of 200 kVp x-rays and a 135 MeV/u carbon 12 beam on hematopoietic stem cells (CFU-S and GM-CFC) are described. The rationale for this experimental approach is that the sensitivity of hematopoietic stem cells and the committed stem cells to radiation is often the treatment limiting-factor for radiotherapy. (author)

  12. Nuclear micro-beam analysis of deuterium distribution in carbon fibre composites for controlled fusion devices

    International Nuclear Information System (INIS)

    Petersson, P.; Kreter, A.; Possnert, G.; Rubel, M.

    2010-01-01

    Probes made of carbon fibre composite NB41 were exposed to deuterium plasmas in the TEXTOR tokamak and in a simulator of plasma-wall interactions, PISCES. The aim was to assess the deuterium retention and its lateral and depth distribution. The analysis was performed by means of D( 3 He, p) 4 He and 12 C( 3 He, p) 14 N nuclear reactions analysis using a standard (1 mm spot) and micro-beam (20 μm resolution). The measurements have revealed non uniform distribution of deuterium atoms in micro-regions: differences by a factor of 3 between the maximum and minimum deuterium concentrations. The differences were associated with the orientation and type of fibres for samples exposed in PICSES. For surface structure in the erosion zone of samples exposed to a tokamak plasma the micro-regions were more complex. Depth profiling has indicated migration of fuel into the bulk of materials.

  13. Quantification of the Relative Biological Effectiveness for Ion Beam Radiotherapy: Direct Experimental Comparison of Proton and Carbon Ion Beams and a Novel Approach for Treatment Planning

    International Nuclear Information System (INIS)

    Elsaesser, Thilo; Weyrather, Wilma K.; Friedrich, Thomas; Durante, Marco; Iancu, Gheorghe; Kraemer, Michael; Kragl, Gabriele; Brons, Stephan; Winter, Marcus; Weber, Klaus-Josef; Scholz, Michael

    2010-01-01

    Purpose: To present the first direct experimental in vitro comparison of the biological effectiveness of range-equivalent protons and carbon ion beams for Chinese hamster ovary cells exposed in a three-dimensional phantom using a pencil beam scanning technique and to compare the experimental data with a novel biophysical model. Methods and Materials: Cell survival was measured in the phantom after irradiation with two opposing fields, thus mimicking the typical patient treatment scenario. The novel biophysical model represents a substantial extension of the local effect model, previously used for treatment planning in carbon ion therapy for more than 400 patients, and potentially can be used to predict effectiveness of all ion species relevant for radiotherapy. A key feature of the new approach is the more sophisticated consideration of spatially correlated damage induced by ion irradiation. Results: The experimental data obtained for Chinese hamster ovary cells clearly demonstrate that higher cell killing is achieved in the target region with carbon ions as compared with protons when the effects in the entrance channel are comparable. The model predictions demonstrate agreement with these experimental data and with data obtained with helium ions under similar conditions. Good agreement is also achieved with relative biological effectiveness values reported in the literature for other cell lines for monoenergetic proton, helium, and carbon ions. Conclusion: Both the experimental data and the new modeling approach are supportive of the advantages of carbon ions as compared with protons for treatment-like field configurations. Because the model predicts the effectiveness for several ion species with similar accuracy, it represents a powerful tool for further optimization and utilization of the potential of ion beams in tumor therapy.

  14. GPU-accelerated automatic identification of robust beam setups for proton and carbon-ion radiotherapy

    International Nuclear Information System (INIS)

    Ammazzalorso, F; Jelen, U; Bednarz, T

    2014-01-01

    We demonstrate acceleration on graphic processing units (GPU) of automatic identification of robust particle therapy beam setups, minimizing negative dosimetric effects of Bragg peak displacement caused by treatment-time patient positioning errors. Our particle therapy research toolkit, RobuR, was extended with OpenCL support and used to implement calculation on GPU of the Port Homogeneity Index, a metric scoring irradiation port robustness through analysis of tissue density patterns prior to dose optimization and computation. Results were benchmarked against an independent native CPU implementation. Numerical results were in agreement between the GPU implementation and native CPU implementation. For 10 skull base cases, the GPU-accelerated implementation was employed to select beam setups for proton and carbon ion treatment plans, which proved to be dosimetrically robust, when recomputed in presence of various simulated positioning errors. From the point of view of performance, average running time on the GPU decreased by at least one order of magnitude compared to the CPU, rendering the GPU-accelerated analysis a feasible step in a clinical treatment planning interactive session. In conclusion, selection of robust particle therapy beam setups can be effectively accelerated on a GPU and become an unintrusive part of the particle therapy treatment planning workflow. Additionally, the speed gain opens new usage scenarios, like interactive analysis manipulation (e.g. constraining of some setup) and re-execution. Finally, through OpenCL portable parallelism, the new implementation is suitable also for CPU-only use, taking advantage of multiple cores, and can potentially exploit types of accelerators other than GPUs.

  15. GPU-accelerated automatic identification of robust beam setups for proton and carbon-ion radiotherapy

    Science.gov (United States)

    Ammazzalorso, F.; Bednarz, T.; Jelen, U.

    2014-03-01

    We demonstrate acceleration on graphic processing units (GPU) of automatic identification of robust particle therapy beam setups, minimizing negative dosimetric effects of Bragg peak displacement caused by treatment-time patient positioning errors. Our particle therapy research toolkit, RobuR, was extended with OpenCL support and used to implement calculation on GPU of the Port Homogeneity Index, a metric scoring irradiation port robustness through analysis of tissue density patterns prior to dose optimization and computation. Results were benchmarked against an independent native CPU implementation. Numerical results were in agreement between the GPU implementation and native CPU implementation. For 10 skull base cases, the GPU-accelerated implementation was employed to select beam setups for proton and carbon ion treatment plans, which proved to be dosimetrically robust, when recomputed in presence of various simulated positioning errors. From the point of view of performance, average running time on the GPU decreased by at least one order of magnitude compared to the CPU, rendering the GPU-accelerated analysis a feasible step in a clinical treatment planning interactive session. In conclusion, selection of robust particle therapy beam setups can be effectively accelerated on a GPU and become an unintrusive part of the particle therapy treatment planning workflow. Additionally, the speed gain opens new usage scenarios, like interactive analysis manipulation (e.g. constraining of some setup) and re-execution. Finally, through OpenCL portable parallelism, the new implementation is suitable also for CPU-only use, taking advantage of multiple cores, and can potentially exploit types of accelerators other than GPUs.

  16. Role of carbon-11 choline PET/CT in the management of uterine carcinoma. Initial experience

    International Nuclear Information System (INIS)

    Sofue, Keitaro; Sawada, Morio; Arai, Yasuaki; Tateishi, Ukihide; Inoue, Tomio; Maeda, Tetsuo; Sugimura, Kazuro; Terauchi, Takashi; Kano, Daisuke

    2009-01-01

    The present study was conducted to clarify the role of carbon-11 choline ( 11 C-choline) positron emission tomography (PET)/computed tomography (CT) in the management of uterine carcinoma. Twenty-two patients who underwent 11 C-choline PET/CT and pelvic MRI were evaluated retrospectively. The images were reviewed by a board-certified radiologist and a nuclear medicine specialist who were unaware of any clinical information, and a consensus was reached. Diagnostic accuracy of PET/CT was evaluated for staging. The reference standard consisted of histological examination (n=17) and follow-up conventional CT (n=5). In five patients with cervical carcinoma, 11 C-choline PET/CT was performed before and after treatment that consisted of cisplatin infusion and subsequent radiotherapy. Standardized uptake value (SUV) was compared with unidimensional and volumetric measurements that were made on magnetic resonance images (MRI) before and after treatment. Based on PET/CT interpretations, the reviewers correctly classified tumor (T) stage in 8 patients (47%), nodes (N) stage in 21 patients (96%), metastasis (M) stage in 20 patients (91%), and tumor, nodes and metastasis (TNM) stage in 15 patients (88%). Tumor size, volume, and SUV decreased after treatment in five patients with cervical carcinoma. Using the Pearson correlation test, a significant correlation was found between the reduction rate of SUV and reduction rate of tumor volume. 11 C-choline PET/CT is an accurate means for the management of patients with uterine carcinoma. The combination of 11 C-choline PET/CT and MRI increases the accuracy of staging in patients with uterine carcinoma. (author)

  17. Plasma-assisted molecular beam epitaxy of (11-22)-oriented 3-nitrides

    International Nuclear Information System (INIS)

    Lahourcade, L.

    2009-10-01

    This work reports on the molecular-beam epitaxial growth of (1122)-oriented semi-polar nitride semiconductors using m-sapphire substrates. The (1122) crystallographic orientation is predefined by AlN deposition on m-sapphire under N excess. On top of this AlN buffer layer, undoped or Si-doped two-dimensional GaN(1122) films are formed under Ga-rich conditions, with a stabilized Ga-excess ad-layer of about 1.05±0.10 ML. In contrast, Mg tends to segregate on the GaN surface, inhibiting the self-regulated Ga excess film. Nevertheless, uniform Mg incorporation can be obtained, and p-type conductivity was achieved. GaN/AlN quantum wells are synthesized by deposition of the binary compounds under the above-described conditions. In the case of GaN/AlN quantum dots, the three-dimensional transition is induced by a growth interruption under vacuum. The reduction of the internal electric field in GaN/AlN nano-structures is confirmed by the blue shift of the photoluminescence spectrum and by the short photoluminescence decay times measured at low temperature. These results are consistent with theoretical calculations of the electronic structure. (author)

  18. Non-uniform shrinkage of multiple-walled carbon nanotubes under in situ electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lunxiong [South China Normal University, Brain Science Institute, Guangzhou (China); Xiamen University, China-Australia Joint Laboratory for Functional Nanomaterials and Physics Department, Xiamen (China); Su, Jiangbin [Xiamen University, China-Australia Joint Laboratory for Functional Nanomaterials and Physics Department, Xiamen (China); Chang Zhou University, School of Mathematics and Physics, Changzhou (China); Zhu, Xianfang [Xiamen University, China-Australia Joint Laboratory for Functional Nanomaterials and Physics Department, Xiamen (China)

    2016-10-15

    Instability of multiple-walled carbon nanotubes (MWCNTs) was investigated by in situ transmission electron microscopy at room temperature. Specially, the non-uniform shrinkage of tubes was found: The pristine MWCNT shrank preferentially in its axial direction from the most curved free cap end of the tube, but the shrinkage of the tube diameter was offset by the axial shrinkage: For the complex MWCNT, the two inner MWCNTs also preferentially axially shrank from their most curved cap ends and separated from each other. However, for the effect of the radial pressure from the out walls which enveloped the two inner tubes and the tube amorphization, the two inner tubes were extruded to come close to each other and finally touched again. The new ''evaporation'' and ''diffusion'' mechanisms of carbon atoms as driven by the nano-curvature of CNT and the electron beam-induced athermal activation were suggested to explain the above phenomena. (orig.)

  19. Increased Tensile Strength of Carbon Nanotube Yarns and Sheets through Chemical Modification and Electron Beam Irradiation

    Science.gov (United States)

    Miller, Sandi G.; Williams, Tiffany S.; Baker, James S.; Sola, Francisco; Lebron-Colon, Marisabel; McCorkle, Linda S.; Wilmoth, Nathan G.; Gaier, James; Chen, Michelle; Meador, Michael A.

    2014-01-01

    The inherent strength of individual carbon nanotubes offers considerable opportunity for the development of advanced, lightweight composite structures. Recent work in the fabrication and application of carbon nanotube (CNT) forms such as yarns and sheets has addressed early nanocomposite limitations with respect to nanotube dispersion and loading; and has pushed the technology toward structural composite applications. However, the high tensile strength of an individual CNT has not directly translated to macro-scale CNT forms where bulk material strength is limited by inter-tube electrostatic attraction and slippage. The focus of this work was to assess post processing of CNT sheet and yarn to improve the macro-scale strength of these material forms. Both small molecule functionalization and e-beam irradiation was evaluated as a means to enhance tensile strength and Youngs modulus of the bulk CNT material. Mechanical testing results revealed a tensile strength increase in CNT sheets by 57 when functionalized, while an additional 48 increase in tensile strength was observed when functionalized sheets were irradiated; compared to unfunctionalized sheets. Similarly, small molecule functionalization increased yarn tensile strength up to 25, whereas irradiation of the functionalized yarns pushed the tensile strength to 88 beyond that of the baseline yarn.

  20. Measurement of characteristic prompt gamma rays emitted from oxygen and carbon in tissue-equivalent samples during proton beam irradiation.

    Science.gov (United States)

    Polf, Jerimy C; Panthi, Rajesh; Mackin, Dennis S; McCleskey, Matt; Saastamoinen, Antti; Roeder, Brian T; Beddar, Sam

    2013-09-07

    The purpose of this work was to characterize how prompt gamma (PG) emission from tissue changes as a function of carbon and oxygen concentration, and to assess the feasibility of determining elemental concentration in tissues irradiated with proton beams. For this study, four tissue-equivalent water-sucrose samples with differing densities and concentrations of carbon, hydrogen, and oxygen were irradiated with a 48 MeV proton pencil beam. The PG spectrum emitted from each sample was measured using a high-purity germanium detector, and the absolute detection efficiency of the detector, average beam current, and delivered dose distribution were also measured. Changes to the total PG emission from (12)C (4.44 MeV) and (16)O (6.13 MeV) per incident proton and per Gray of absorbed dose were characterized as a function of carbon and oxygen concentration in the sample. The intensity of the 4.44 MeV PG emission per incident proton was found to be nearly constant for all samples regardless of their carbon concentration. However, we found that the 6.13 MeV PG emission increased linearly with the total amount (in grams) of oxygen irradiated in the sample. From the measured PG data, we determined that 1.64 × 10(7) oxygen PGs were emitted per gram of oxygen irradiated per Gray of absorbed dose delivered with a 48 MeV proton beam. These results indicate that the 6.13 MeV PG emission from (16)O is proportional to the concentration of oxygen in tissue irradiated with proton beams, showing that it is possible to determine the concentration of oxygen within tissues irradiated with proton beams by measuring (16)O PG emission.

  1. Conversion from dose-to-graphite to dose-to-water in an 80 MeV/A carbon ion beam.

    Science.gov (United States)

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

    2013-08-21

    Based on experiments and numerical simulations, a study is carried out pertaining to the conversion of dose-to-graphite to dose-to-water in a carbon ion beam. This conversion is needed to establish graphite calorimeters as primary standards of absorbed dose in these beams. It is governed by the water-to-graphite mass collision stopping power ratio and fluence correction factors, which depend on the particle fluence distributions in each of the two media. The paper focuses on the experimental and numerical determination of this fluence correction factor for an 80 MeV/A carbon ion beam. Measurements have been performed in the nuclear physics laboratory INFN-LNS in Catania (Sicily, Italy). The numerical simulations have been made with a Geant4 Monte Carlo code through the GATE simulation platform. The experimental data are in good agreement with the simulated results for the fluence correction factors and are found to be close to unity. The experimental values increase with depth reaching 1.010 before the Bragg peak region. They have been determined with an uncertainty of 0.25%. Different numerical results are obtained depending on the level of approximation made in calculating the fluence correction factors. When considering carbon ions only, the difference between measured and calculated values is maximal just before the Bragg peak, but its value is less than 1.005. The numerical value is close to unity at the surface and increases to 1.005 near the Bragg peak. When the fluence of all charged particles is considered, the fluence correction factors are lower than unity at the surface and increase with depth up to 1.025 before the Bragg peak. Besides carbon ions, secondary particles created due to nuclear interactions have to be included in the analysis: boron ions ((10)B and (11)B), beryllium ions ((7)Be), alpha particles and protons. At the conclusion of this work, we have the conversion of dose-to-graphite to dose-to-water to apply to the response of a graphite

  2. Carbon Incorporation and Anion Dynamics as Synergistic Drivers for Ultrafast Diffusion in Superionic LiCB11H12 and NaCB11H12

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrievska, Mirjana [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Shea, Patrick [Lawrence Livermore National Laboratory; Kweon, Kyoung E. [Lawrence Livermore National Laboratory; Bercx, Marnik [University of Antwerp; Varley, Joel B. [Lawrence Livermore National Laboratory; Tang, Wan Si [National Institute of Standards and Technology; University of Maryland; Skripov, Alexander V. [Ural Division of the Russian Academy of Sciences; Stavila, Vitalie [Sandia National Laboratories; Udovic, Terrence J. [National Institute of Standards and Technology; Wood, Brandon C. [Lawrence Livermore National Laboratory

    2018-02-02

    The disordered phases of LiCB11H12 and NaCB11H12 possess superb superionic conductivities that make them suitable as solid electrolytes. In these materials, cation diffusion correlates with high orientational mobilities of the CB11H12- anions; however, the precise relationship has yet to be demonstrated. In this work, ab initio molecular dynamics and quasielastic neutron scattering are combined to probe anion reorientations and their mechanistic connection to cation mobility over a range of timescales and temperatures. It is found that anions do not rotate freely, but rather transition rapidly between orientations defined by the cation sublattice symmetry. The symmetry-breaking carbon atom in CB11H12- also plays a critical role by perturbing the energy landscape along the instantaneous orientation of the anion dipole, which couples fluctuations in the cation probability density directly to the anion motion. Anion reorientation rates exceed 3 x 1010 s-1, suggesting the underlying energy landscape fluctuates dynamically on diffusion-relevant timescales. Furthermore, carbon is found to modify the orientational preferences of the anions and aid rotational mobility, creating additional symmetry incompatibilities that inhibit ordering. The results suggest that synergy between the anion reorientational dynamics and the carbon-modified cation-anion interaction accounts for the higher ionic conductivity in CB11H12- salts compared with B12H122-.

  3. Analyzing the effect of carbon fiber reinforced polymer on the crashworthiness of aluminum square hollow beam for crash box application

    Science.gov (United States)

    Raman, R.; Jayanth, K.; Sarkar, I.; Ravi, K.

    2017-11-01

    Crashworthiness of a material is a measure of its ability to absorb energy during a crash. A well-designed crash box is instrumental in protecting the costly vehicle components. A square, hollow, hybrid beam of aluminum/CFRP was subjected to dynamic axial load to analyze the effect of five different lay-up sequences on its crashworthiness. The beam was placed between two plates. Boundary conditions were imposed on them to simulate a frontal body crash test model. Modeling and dynamic analysis of composite structures was done on ABAQUS. Different orientation of carbon fibers varies the crashworthiness of the hybrid beam. Addition of CFRP layer showed clear improvement in specific energy absorption and crush force efficiency compared to pure aluminum beam. Two layers of CFRP oriented at 90° on Aluminum showed 52% increase in CFE.

  4. Bending analysis of agglomerated carbon nanotube-reinforced beam resting on two parameters modified Vlasov model foundation

    Science.gov (United States)

    Ghorbanpour Arani, A.; Zamani, M. H.

    2018-06-01

    The present work deals with bending behavior of nanocomposite beam resting on two parameters modified Vlasov model foundation (MVMF), with consideration of agglomeration and distribution of carbon nanotubes (CNTs) in beam matrix. Equivalent fiber based on Eshelby-Mori-Tanaka approach is employed to determine influence of CNTs aggregation on elastic properties of CNT-reinforced beam. The governing equations are deduced using the principle of minimum potential energy under assumption of the Euler-Bernoulli beam theory. The MVMF required the estimation of γ parameter; to this purpose, unique iterative technique based on variational principles is utilized to compute value of the γ and subsequently fourth-order differential equation is solved analytically. Eventually, the transverse displacements and bending stresses are obtained and compared for different agglomeration parameters, various boundary conditions simultaneously and variant elastic foundation without requirement to instate values for foundation parameters.

  5. Prestressing Effects on the Performance of Concrete Beams with Near-surface-mounted Carbon-fiber-reinforced Polymer Bars

    Science.gov (United States)

    Hong, Sungnam; Park, Sun-Kyu

    2016-07-01

    The effects of various prestressing levels on the flexural behavior of concrete beams strengthened with prestressed near-surface-mounted (NSM) carbon-fiber-reinforced polymer (CFRP) bars were investigated in this study. Four-point flexural tests up to failure were performed using a total of six strengthened prestressed and nonprestressed concrete beams. The nonprestressed strengthened beam failed by premature debonding at the interface of concrete and the epoxy adhesive, but the prestressed one failed owing due to rupture of the CFRP bar. As the prestressing level of the CFRP bar increased, the cracking and yield loads of the prestressed beams increased, but its effect on their deflections was insignificant. The ultimate load was constant regardless of prestressing level, but the ultimate deflection was almost inversely proportional to the level.

  6. Carbon-11 labeled diacylglycerol for signal transduction imaging by positron CT. Evaluation of the quality and safety for clinical use

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Ryou [Nishijin Hospital, Kyoto (Japan); Imahori, Yoshio; Ido, Tatsuo [and others

    1995-02-01

    To elucidate the synaptic transmission in the neural system, we have been developing fundamental studies for intracellular signaling. For clinical application of carbon-11 labeled diacylglycerol (1-[1-{sup 11}C]butyryl-2-palmitoyl-rac-glycerol: {sup 11}C-DAG) using positron emission computed tomography (PET), we evaluated the quality and the safety of {sup 11}C-DAG as the solution for injection. As a result, {sup 11}C-DAG was synthesized within 50 minutes, including the preparation step for injection. The half life time and energy spectrum of {sup 11}C-DAG were the same as the physical character of carbon-11, and other radioisotopes were not detected. In the quality control, {sup 11}C-DAG solution was negative in the examination of bacterial contamination and the pyrogen test in three successive synthesis procedures. In the acute toxicity test by administration of {sup 11}C-DAG and 100 {mu}mol/kg of non-radioactive DAG to the rat intravenously, the systemic condition of the rat was not changed and no abnormalities were found in any organ 24 hours after administration. These findings indicated the safety of {sup 11}C-DAG solution. Clinical application of {sup 11}C-DAG using positron emission tomography may be useful to elucidate the dysfunction of intracellular signaling in disorders of higher cortical function such as Alzheimer disease. (author).

  7. THI: goal reached with a carbon beam, and some results of beam tests and theoretical studies related to longitudinal space charge effects

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    During the first semester of this year, two tests were devoted to high intensity beams: 1) trying to reach the ultimate goal with a carbon beam and 2) going further into the study of perturbing phenomena. A 1.3 x 10 13 pps 13 C beam was successfully extracted from SSC2 and sustained for 13 hours with an excellent stability. Then, the current was increased to 2 x 10 13 pps with no major problem. Therefore, it is possible from now on to bombard the 2 kW target which is prepared for the production of helium isotopes and subsequent acceleration in the new cyclotron CIME. Both experimental and simulation studies were carried in parallel, in the frame of the last year expertise, in order to get a better knowledge and control of the effect of longitudinal space charge forces. It appears that these effects affect the beam width mostly in SSC2, while a discrepancy between computer simulations and measurements seems to show up concerning the effect of neighbouring bunches. (author)

  8. Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

    KAUST Repository

    Batra, Nitin M; Patole, Shashikant P.; Abdelkader, Ahmed; Anjum, Dalaver H.; Deepak, Francis L; Da Costa, Pedro M. F. J.

    2015-01-01

    The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode–interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode–nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

  9. Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

    KAUST Repository

    Batra, Nitin M

    2015-10-09

    The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode–interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode–nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

  10. Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices.

    Science.gov (United States)

    Batra, Nitin M; Patole, Shashikant P; Abdelkader, Ahmed; Anjum, Dalaver H; Deepak, Francis L; Costa, Pedro M F J

    2015-11-06

    The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode-interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode-nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

  11. Form of inorganic carbon utilized for photosynthesis in Chlorella vulgaris 11h cells

    International Nuclear Information System (INIS)

    Miyachi, Shigetoh; Shiraiwa, Yoshihiro

    1979-01-01

    The rate of photosynthetic 14 CO 2 fixation in Chlorella vulgaris 11h cells in the presence of 0.55 mM NaH 14 CO 3 at pH 8.0 (20 0 C) was greatly enhanced by the addition of carbonic anhydrase (CA). However, when air containing 400 ppm 14 CO 2 was bubbled through the algal suspension, the rate of 14 CO 2 fixation immediately after the start of the bubbling was suppressed by CA. These effects of CA were observed in cells which had been grown in air containing 2% CO 2 (high-CO 2 cells) as well as those grown in ordinary air (containing 0.04% CO 2 , low-CO 2 cells). We therefore concluded that, irrespective of the CO 2 concentration given to the algal cells during growth, the active species of inorganic carbon absorbed by Chlorella cells is free CO 2 and they cannot utilize bicarbonate. The effects observed in the high-CO 2 cells were much more pronounced than those in the low-CO 2 cells. This difference was accounted for by the difference in the affinity for CO 2 in photosynthesis between the high- and low-CO 2 cells. (author)

  12. Studies of cryocooler based cryosorption pump with activated carbon panels operating at 11K

    International Nuclear Information System (INIS)

    Kasthurirengan, S; Behera, Upendra; Gangradey, Ranjana; Udgata, Swarup; Krishnamoorthy, V

    2012-01-01

    Cryosorption pump is the only solution for pumping helium and hydrogen in fusion reactors. It is chosen because it offers highest pumping speed as well as the only suitable pump for the harsh environments in a tokamak. Towards the development of such cryosorption pumps, the optimal choice of the right activated carbon panels is essential. In order to characterize the performance of the panels with indigenously developed activated carbon, a cryocooler based cryosorption pump with scaled down sizes of panels is experimented. The results are compared with the commercial cryopanel used in a CTI cryosorption (model: Cryotorr 7) pump. The cryopanel is mounted on the cold head of the second stage GM cryocooler which cools the cryopanel down to 11K with first stage reaching about ∼50K. With no heat load, cryopump gives the ultimate vacuum of 2.1E-7 mbar. The pumping speed of different gases such as nitrogen, argon, hydrogen, helium are tested both on indigenous and commercial cryopanel. These studies serve as a bench mark towards the development of better cryopanels to be cooled by liquid helium for use with tokamak.

  13. Tracers development for the PET study of nicotinic receptors: [11C]-mecamylamine and [11C]-SIB 1553A. Tritium and carbon-11 radiolabelling of a serine proteinase inhibitor: the t-PAstop

    International Nuclear Information System (INIS)

    Sobrio, F.

    2002-12-01

    In order to develop radiotracers for the Positron Emission Tomography (PET), we labelled both the mecamylamine and SIB-1553A with carbon-11 to study the nicotinic cholinergic receptors (nAChRs). The radiosynthesis of [ 11 C]-t-PA stop and the labelling with tritium of one analogue were realized for cerebral ischemia PET studies. The [ 11 C]-mecamylamine, a non-competitive and non-selective nAChRs antagonist was synthesized in 45 min via a N-[ 11 C]-methylation reaction. In the rat brain, the ex vivo studies showed no radio-metabolite 45 min after the injection of [ 11 C]-mecamylamine. The uptake kinetics in the rat brain or in vivo by PET in the anesthetized baboon or in the conscious monkey, reached a plateau around 45-50 min after injection. However, the saturation or displacement experiments did not permit to exhibit nor a significant difference of labelling between the different cerebral regions nor a specific uptake. In consequence, the [ 11 C]-mecamylamine was not an appropriate radioligand for nAChRs PET study. The labelling of [ 11 C]-SIB 1553A, a selective agonist for the nicotinic β4 subunit, required the synthesis in 5 steps (56% overall yield) of precursor for the incorporation of carbon-11. The radiosynthesis was performed in 36 min by a N-[ 11 C]-methylation reaction (yield: 75%). The [ 11 C]-t-PA stop was obtained from [ 11 C]-KCN with yields from 80 to 90%. For the first time with carbon-11, the formation of an amidine group was realized from a nitrile group. The labelling by isotopic exchange of hydrogen by tritium of the t-PA stop did not permit to obtain the [ 3 H]-t-PA stop but a tritiated analogue. This compound will be used to study its vectorization by micro-encapsulation. (author)

  14. Facile synthesis of carbon-11-labeled arylpiperazinylthioalkyl derivatives as new PET radioligands for imaging of 5-HT1AR

    International Nuclear Information System (INIS)

    Gao Mingzhang; Wang Min; Zheng Qihuang

    2012-01-01

    Carbon-11-labeled arylpiperazinylthioalkyl derivatives, 2-((4-(4-(2-[ 11 C]methoxyphenyl)piperazin-1-yl)butyl)thio)benzo[d]oxazole ([ 11 C]5a), 2-((4-(4-(2-[ 11 C]methoxyphenyl)piperazin-1-yl)butyl)thio)-5,7-dimethylbenzo [d]oxazole ([ 11 C]5c), 2-((4-(4-(2-[ 11 C]methoxyphenyl)piperazin-1-yl)butyl)thio)benzo[d]thiazole ([ 11 C]5e), 2-((6-(4-(2-[ 11 C]methoxyphenyl)piperazin-1-yl)hexyl)thio)benzo[d]oxazole ([ 11 C]5g), 2-((6-(4-(2-[ 11 C]methoxyphenyl)piperazin-1-yl)hexyl)thio)-5,7-dimethylbenzo [d]oxazole ([ 11 C]5i), and 2-((6-(4-(2-[ 11 C]methoxyphenyl)piperazin-1-yl)hexyl)thio)benzo[d]thiazole ([ 11 C]5k), were prepared from their corresponding phenol precursors with [ 11 C]CH 3 OTf through O-[ 11 C]methylation and isolated by a simplified solid-phase extraction (SPE) method using a Sep-Pak Plus C18 cartridge in 50–60% (n=5) radiochemical yields based on [ 11 C]CO 2 and decay corrected to end of bombardment (EOB). The overall synthesis time from EOB was 23 min, the radiochemical purity was >99%, and the specific activity at end of synthesis (EOS) was 277.5±92.5 GBq/μmol (n=5). - Highlights: ► New arylpiperazinylthioalkyl derivatives were synthesized. ► New carbon-11-labeled arylpiperazinylthioalkyl derivatives were synthesized. ► Simplified solid-phase extraction (SPE) method was employed in radiosynthesis.

  15. Synthesis and positron emission tomography studies of carbon-11-labeled imatinib (Gleevec)

    Energy Technology Data Exchange (ETDEWEB)

    Kil, Kun-Eek [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400 (United States); Ding Yushin [Department of Radiology, Yale University School of Medicine, New Haven, CT 06520-8048 (United States); Lin Kuoshyan [Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Alexoff, David [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Kim, Sung Won [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400 (United States); Shea, Colleen [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Xu Youwen [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Muench, Lisa [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Fowler, Joanna S. [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States) and Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400 (United States)]. E-mail: fowler@bnl.gov

    2007-02-15

    Introduction: Imatinib mesylate (Gleevec) is a well known drug for treating chronic myeloid leukemia and gastrointestinal stromal tumors. Its active ingredient, imatinib ([4-[(4-methyl-1-piperazinyl)methyl]-N-[4-methyl-3-[[4-(3-pyridyl) -2-pyrimidinyl]amino]phenyl]benzamide), blocks the activity of several tyrosine kinases. Here we labeled imatinib with carbon-11 as a tool for determining the drug distribution and pharmacokinetics of imatinib, and we carried out positron emission tomography (PET) studies in baboons. Methods: [N-{sup 11}C-methyl]imatinib was synthesized from [{sup 11}C]methyl iodide and norimatinib was synthesized by the demethylation of imatinib (isolated from Gleevec tablets) according to a patent procedure [Collins JM, Klecker RW Jr, Anderson LW. Imaging of drug accumulation as a guide to antitumor therapy. US Patent 20030198594A1, 2003]. Norimatinib was also synthesized from the corresponding amine and acid. PET studies were carried out in three baboons to measure pharmacokinetics in the brain and peripheral organs and to determine the effect of a therapeutic dose of imatinib. Log D and plasma protein binding were also measured. Results: [N-{sup 11}C-methyl]imatinib uptake in the brain is negligible (consistent with P-glycoprotein-mediated efflux); it peaks and clears rapidly from the heart, lungs and spleen. Peak uptake and clearance occur more slowly in the liver and kidneys, followed by accumulation in the gallbladder and urinary bladder. Pretreatment with imatinib did not change uptake in the heart, lungs, kidneys and spleen, and increased uptake in the liver and gallbladder. Conclusions: [N-{sup 11}C-methyl]imatinib has potential for assessing the regional distribution and kinetics of imatinib in the human body to determine whether the drug targets tumors and to identify other organs to which the drug or its labeled metabolites distribute. Paired with tracers such as 2'deoxy-2'-[{sup 18}F]fluoro-D-glucose ({sup 18}FDG) and 3&apos

  16. Preparation and electrical-property characterization of poly(vinyl chloride)-derived carbon nanosheet by ion beam irradiation-induced carbon clustering and carbonization

    Science.gov (United States)

    Jung, Chan-Hee; Sohn, Joon-Yong; Kim, Hyo-Sub; Hwang, In-Tae; Lee, Hong-Joon; Shin, Junhwa; Choi, Jae-Hak

    2018-05-01

    In this work, we demonstrated that carbon nanosheet (CNS) can easily be produced by a room-temperature, solid-state proton irradiation-induced clustering of poly(vinyl chloride) (PVC) films followed by carbonization. The results of the optical, chemical, and structural analyses revealed that oxidized and sp2-hybridized carbon clusters were effectively created in the PVC thin film by combined dehydrochlorination and inter-coupling reactions during proton irradiation. This was further converted to pseudo-hexagonally-structured nano-crystalline CNS with 2-D symmetry and metallic transporting character by high-temperature treatment. As a result, the CNS exhibited a very high electrical conductivity (587 S/cm) without a significant change in their thickness, a low surface roughness (0.36 nm), and a high work function (5.11 eV). These findings demonstrate that the radiation-based approach opens new avenues for the design and development of 2-D CNS as a graphene allotrope for the application of electronic devices, including field-effect transistors, electric heating devices, biosensors, supercapacitors, and fuel cells.

  17. TU-E-BRA-11: Volume of Interest Cone Beam CT with a Low-Z Linear Accelerator Target: Proof-of-Concept.

    Science.gov (United States)

    Robar, J; Parsons, D; Berman, A; MacDonald, A

    2012-06-01

    This study demonstrates feasibility and advantages of volume of interest (VOI) cone beam CT (CBCT) imaging performed with an x-ray beam generated from 2.35 MeV electrons incident on a carbon linear accelerator target. The electron beam energy was reduced to 2.35 MeV in a Varian 21EX linear accelerator containing a 7.6 mm thick carbon x-ray target. Arbitrary imaging volumes were defined in the planning system to produce dynamic MLC sequences capable of tracking off-axis VOIs in phantoms. To reduce truncation artefacts, missing data in projection images were completed using a priori DRR information from the planning CT set. The feasibility of the approach was shown through imaging of an anthropomorphic phantom and the head-and-neck section of a lamb. TLD800 and EBT2 radiochromic film measurements were used to compare the VOI dose distributions with those for full-field techniques. CNR was measured for VOIs ranging from 4 to 15 cm diameter. The 2.35 MV/Carbon beam provides favorable CNR characteristics, although marked boundary and cupping artefacts arise due to truncation of projection data. These artefacts are largely eliminated using the DRR filling technique. Imaging dose was reduced by 5-10% and 75% inside and outside of the VOI, respectively, compared to full-field imaging for a cranial VOI. For the 2.35 MV/Carbon beam, CNR was shown to be approximately invariant with VOI dimension for bone and lung objects. This indicates that the advantage of the VOI approach with the low-Z target beam is substantial imaging dose reduction, not improvement of image quality. VOI CBCT using a 2.35 MV/Carbon beam is a feasible technique whereby a chosen imaging volume can be defined in the planning system and tracked during acquisition. The novel x-ray beam affords good CNR characteristics while imaging dose is localized to the chosen VOI. Funding for this project has been received from Varian Medical, Incorporated. © 2012 American Association of Physicists in Medicine.

  18. Characterization of nanometer-scale porosity in reservoir carbonate rock by focused ion beam-scanning electron microscopy.

    Science.gov (United States)

    Bera, Bijoyendra; Gunda, Naga Siva Kumar; Mitra, Sushanta K; Vick, Douglas

    2012-02-01

    Sedimentary carbonate rocks are one of the principal porous structures in natural reservoirs of hydrocarbons such as crude oil and natural gas. Efficient hydrocarbon recovery requires an understanding of the carbonate pore structure, but the nature of sedimentary carbonate rock formation and the toughness of the material make proper analysis difficult. In this study, a novel preparation method was used on a dolomitic carbonate sample, and selected regions were then serially sectioned and imaged by focused ion beam-scanning electron microscopy. The resulting series of images were used to construct detailed three-dimensional representations of the microscopic pore spaces and analyze them quantitatively. We show for the first time the presence of nanometer-scale pores (50-300 nm) inside the solid dolomite matrix. We also show the degree of connectivity of these pores with micron-scale pores (2-5 μm) that were observed to further link with bulk pores outside the matrix.

  19. Synthesis of carbon-11-labeled 5-HT6R antagonists as new candidate PET radioligands for imaging of Alzheimer's disease.

    Science.gov (United States)

    Wang, Xiaohong; Dong, Fugui; Miao, Caihong; Li, Wei; Wang, Min; Gao, Mingzhang; Zheng, Qi-Huang; Xu, Zhidong

    2018-06-01

    Carbon-11-labeled serotonin (5-hydroxytryptamine) 6 receptor (5-HT 6 R) antagonists, 1-[(2-bromophenyl)sulfonyl]-5-[ 11 C]methoxy-3-[(4-methyl-1-piperazinyl)methyl]-1H-indole (O-[ 11 C]2a) and 1-[(2-bromophenyl)sulfonyl]-5-methoxy-3-[(4-[ 11 C]methyl-1-piperazinyl)methyl]-1H-indole (N-[ 11 C]2a), 5-[ 11 C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1-(phenylsulfonyl)-1H-indole (O-[ 11 C]2b) and 5-methoxy-3-((4-[ 11 C]methylpiperazin-1-yl)methyl)-1-(phenylsulfonyl)-1H-indole (N-[ 11 C]2b), 1-((4-isopropylphenyl)sulfonyl)-5-[ 11 C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1H-indole (O-[ 11 C]2c) and 1-((4-isopropylphenyl)sulfonyl)-5-methoxy-3-((4-[ 11 C]methylpiperazin-1-yl)methyl)-1H-indole (N-[ 11 C]2c), 1-((4-fluorophenyl)sulfonyl)-5-[ 11 C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1H-indole (O-[ 11 C]2d) and 1-((4-fluorophenyl)sulfonyl)-5-methoxy-3-((4-[ 11 C]methylpiperazin-1-yl)methyl)-1H-indole (N-[ 11 C]2d), were prepared from their O- or N-desmethylated precursors with [ 11 C]CH 3 OTf through O- or N-[ 11 C]methylation and isolated by HPLC combined with SPE in 40-50% radiochemical yield, based on [ 11 C]CO 2 and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the molar activity (MA) at EOB was 370-740 GBq/μmol with a total synthesis time of ∼40-min from EOB. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    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 12 C 6+ ), and mutations in the rpsL gene were analyzed. Mutant frequency increased significantly following irradiation by γ-rays, but not by 320-MeV 12 C 6+ . Mutation spectra showed that both radiations increased the frequency of frameshifts and other mutations, including deletions and insertions, but only γ-rays increased the frequency of total base substitutions. These results suggest that the type of DNA lesions which cause base substitutions were less often induced by 320-MeV 12 C 6+ than by γ-rays in Arabidopsis seedlings. Furthermore, γ-rays never increased the frequencies of G:C to T:A or A:T to C:G transversions, which are caused by oxidized guanine; 320-MeV 12 C 6+ , however, produced a slight increase in both transversions. Instead, γ-rays produced a significant increase in the frequency of G:C to A:T transitions. These results suggest that 8-oxoguanine has little effect on mutagenesis in Arabidopsis cells. (author)

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

    DEFF Research Database (Denmark)

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

    Introduction: Predictions of the radiobiological effectiveness (RBE) play an essential role in treatment planning with heavy charged particles. Amorphous track models ( [1] , [2] , also referred to as track structure models) provide currently the most suitable description of cell survival under i....... Amorphous track modelling of luminescence detector efficiency in proton and carbon beams. 4.Tsuruoka C, Suzuki M, Kanai T, et al. LET and ion species dependence for cell killing in normal human skin fibroblasts. Radiat Res. 2005;163:494-500.......Introduction: Predictions of the radiobiological effectiveness (RBE) play an essential role in treatment planning with heavy charged particles. Amorphous track models ( [1] , [2] , also referred to as track structure models) provide currently the most suitable description of cell survival under ion....... [2] . In addition, a new approach based on microdosimetric distributions is presented and investigated [3] . Material and methods: A suitable software library embrasing the mentioned amorphous track models including numerous submodels with respect to delta-electron range models, radial dose...

  2. Flexural behaviour of partially bonded carbon fibre reinforced polymers strengthened concrete beams: Application to fire protection systems design

    International Nuclear Information System (INIS)

    Firmo, J.P.; Arruda, M.R.T.; Correia, J.R.; Tiago, C.

    2015-01-01

    Highlights: • The mechanical behaviour of partially bonded CFRP strengthened beams was modelled. • Two dimensional non-linear finite element models were developed. • Partially bonded beams can present similar flexural strength to fully bonded ones. • Relations between the bonded length and the strength reduction were proposed. • The proposed relations were used for the design of fire protection systems. - Abstract: Recent fire resistance tests on reinforced concrete (RC) beams strengthened with carbon fibre reinforced polymers (CFRP) laminates showed that it is possible to attain considerable fire endurance provided that thermal insulation is applied at the anchorage zones of the strengthening system. With such protection, although the CFRP laminate prematurely debonds in the central part of the beam, it transforms into a cable fixed at the extremities until one of the anchorage zones loses its bond strength. The main objective of this paper is to propose a simplified methodology for the design of fire protection systems for CFRP strengthened-RC beams, which is based on applying thicker insulation at the anchorage zones (promoting the above mentioned “cable behaviour”) and a thinner one at the current zone (avoiding tensile rupture of the carbon fibres). As a first step towards the validation of this methodology, finite element (FE) models were developed to simulate the flexural behaviour at ambient temperature of full-scale RC beams strengthened with CFRP laminates according to the externally bonded reinforcement (EBR) and near surface mounted (NSM) techniques, in both cases fully or partially bonded (the latter simulating the cable). The FE models were calibrated with results of 4-point bending tests on small-scale beams and then extended for different beam geometries, with spans (L) varying from 2 m to 5 m, in which the influence of the CFRP bonded length (l b ) and the loading type (point or uniformly distributed) on the strength reduction was

  3. Production of 11C by the interaction of 375 MeV/amu Ne10+ ions with carbon

    International Nuclear Information System (INIS)

    Smith, A.R.; Thomas, R.H.

    1975-06-01

    The reaction cross section for production of 11 C from 12 C in a polystyrene target has been measured with incident 375-MeV/amu Ne 10+ ions at the Lawrence Berkeley Laboratory's Bevalac. A broad beam irradiation was used, and both beam profile and absolute particle fluence were determined with LiF thermoluminescent dosimeters, which had been calibrated by track counting in nuclear emulsions; the induced target activity was measured with a NaI(Tl)-crystal, γ-ray spectrometer. The reaction cross section was 75 +- 7 mb. (1 figure, 1 table) (U.S.)

  4. Megavoltage photon beam attenuation by carbon fiber couch tops and its prediction using correction factors

    International Nuclear Information System (INIS)

    Hayashi, Naoki; Shibamoto, Yuta; Obata, Yasunori; Kimura, Takashi; Nakazawa, Hisato; Hagiwara, Masahiro; Hashizume, Chisa I.; Mori, Yoshimasa; Kobayashi, Tatsuya

    2010-01-01

    The purpose of this study was to evaluate the effect of megavoltage photon beam attenuation (PBA) by couch tops and to propose a method for correction of PBA. Four series of phantom measurements were carried out. First, PBA by the exact couch top (ECT, Varian) and Imaging Couch Top (ICT, BrainLAB) was evaluated using a water-equivalent phantom. Second, PBA by Type-S system (Med-Tec), ECT and ICT was compared with a spherical phantom. Third, percentage depth dose (PDD) after passing through ICT was measured to compare with control data of PDD. Forth, the gantry angle dependency of PBA by ICT was evaluated. Then, an equation for PBA correction was elaborated and correction factors for PBA at isocenter were obtained. Finally, this method was applied to a patient with hepatoma. PBA of perpendicular beams by ICT was 4.7% on average. With the increase in field size, the measured values became higher. PBA by ICT was greater than that by Type-S system and ECT. PBA increased significantly as the angle of incidence increased, ranging from 4.3% at 180 deg to 11.2% at 120 deg. Calculated doses obtained by the equation and correction factors agreed quite well with the measured doses between 120 deg and 180 deg of angles of incidence. Also in the patient, PBA by ICT was corrected quite well by the equation and correction factors. In conclusion, PBA and its gantry angle dependency by ICT were observed. This simple method using the equation and correction factors appeared useful to correct the isocenter dose when the PBA effect cannot be corrected by a treatment planning system. (author)

  5. Biodistribution of a positron-emitting suicide inactivator of monoamine oxidase, carbon-11 pargyline, in mice and a rabbit

    International Nuclear Information System (INIS)

    Ishiwata, K.; Ido, T.; Yanai, K.; Kawashima, K.; Miura, Y.; Monma, M.; Watanuki, S.; Takahashi, T.; Iwata, R.

    1985-01-01

    Carbon-11 ( 11 C) pargyline, which is a suicide inactivator of Type B monoamine oxidase (MAO), was synthesized by the reaction of N-demethylpargyline with 11 CH 3 l. Biodistribution was investigated in mice, and positron tomographic images of the heart and lung in a rabbit were obtained. The distribution of 11 C after administration of [ 11 C]pargyline was measured in several organs and blood at various time intervals. After 30 min its concentrations in the organs were constant. Subcellular distribution studies in the brain, lung, liver, and kidney showed that 59-70% of the 11 C became acid-insoluble and 9-33% was present in the crude mitochondrial fraction at 60 min after injection. The uptakes of the 11 C in each organ except for the kidney and spleen seemed to correlate with the in vitro enzymatic activity of Type B MAO. At high loading dose a nonspecific uptake was observed

  6. Radio-metabolite analysis of carbon-11 biochemical partitioning to non-structural carbohydrates for integrated metabolism and transport studies.

    Science.gov (United States)

    Babst, Benjamin A; Karve, Abhijit A; Judt, Tatjana

    2013-06-01

    Metabolism and phloem transport of carbohydrates are interactive processes, yet each is often studied in isolation from the other. Carbon-11 ((11)C) has been successfully used to study transport and allocation processes dynamically over time. There is a need for techniques to determine metabolic partitioning of newly fixed carbon that are compatible with existing non-invasive (11)C-based methodologies for the study of phloem transport. In this report, we present methods using (11)C-labeled CO2 to trace carbon partitioning to the major non-structural carbohydrates in leaves-sucrose, glucose, fructose and starch. High-performance thin-layer chromatography (HPTLC) was adapted to provide multisample throughput, raising the possibility of measuring different tissues of the same individual plant, or for screening multiple plants. An additional advantage of HPTLC was that phosphor plate imaging of radioactivity had a much higher sensitivity and broader range of sensitivity than radio-HPLC detection, allowing measurement of (11)C partitioning to starch, which was previously not possible. Because of the high specific activity of (11)C and high sensitivity of detection, our method may have additional applications in the study of rapid metabolic responses to environmental changes that occur on a time scale of minutes. The use of this method in tandem with other (11)C assays for transport dynamics and whole-plant partitioning makes a powerful combination of tools to study carbohydrate metabolism and whole-plant transport as integrated processes.

  7. Static and free vibration analysis of carbon nano wires based on Timoshenko beam theory using differential quadrature method

    Directory of Open Access Journals (Sweden)

    Maziar Janghorban

    Full Text Available Static and free vibration analysis of carbon nano wires with rectangular cross section based on Timoshenko beam theory is studied in this research. Differential quadrature method (DQM is employed to solve the governing equations. From the knowledge of author, it is the first time that free vibration of nano wires is investigated. It is also the first time that differential quadrature method is used for bending analysis of nano wires.

  8. The erosion and erosion products of tungsten and carbon based materials bombarded by high energy pulse electron beam

    International Nuclear Information System (INIS)

    Liu Xiang; Zhang Fu; Xu Zengyu; Liu Yong; Yoshida, N.; Noda, N.

    2002-01-01

    In this paper, the erosion behaviors and erosion products of tungsten and some carbon based materials, such as graphite, C/C composite and B 4 C/Cu functionally graded material, were investigated by using a pulse electron beam to simulate the vertical displacement events (VDE) process. The authors will focus on the forms and differences of erosion products among these testing materials, and make clear to their erosion mechanisms

  9. Optimizing the e-beam profile of a single carbon nanotube field emission device for electric propulsion systems

    Directory of Open Access Journals (Sweden)

    Juliano Fujioka Mologni

    2010-04-01

    Full Text Available Preliminary studies on field emission (FE arrays comprised of carbon nanotubes (CNT as an electron source for electric propulsion system show remarkably promising results. Design parameters for a carbon nanotube (CNT field-emission device operating on triode configuration were numerically simulated and optimized in order to enhance the e-beam focusing quality. An additional focus gate (FG was integrated to the device to control the profile of the emitted e-beam. An axisymmetric finite element model was developed to calculate the electric field distribution on the vacuum region and a modified Fowler-Nordheim (FN equation was used to evaluate the current density emission and the effective emitter area. Afterward, a FE simulation was employed in order to calculate the trajectory of the emitted electrons and define the electron-optical properties of the e-beam. The integration of the FG was fully investigated via computational intelligence techniques. The best performance device according to our simulations presents a collimated e-beam profile that suits well for field emission displays, magnetic field detection and electron microscopy. The automated computational design tool presented in this study strongly benefits the robust design of integrated electron-optical systems for vacuum field emission applications, including electrodynamic tethering and electric propulsion systems.

  10. Tumor induction in mice after local irradiation with single doses of either carbon-ion beams or gamma rays.

    Science.gov (United States)

    Ando, Koichi; Koike, Sachiko; Ohmachi, Yasushi; Ando, Yutaka; Kobashi, Gen

    2014-12-01

    To determine the dose-dependent relative biological effectiveness (RBE) for tumor prevalence in mice receiving single localized doses to their right leg of either carbon ions (15, 45 or 75 keV/μm) or 137Cs gamma rays. A total of 1647 female C3H mice were irradiated to their hind legs with a localized dose of either reference gamma rays or 15, 45 or 75 keV/μm carbon-ion beams. Irradiated mice were evaluated for tumors twice a month during their three-year life span, and the dimensions of any tumors found were measured with a caliper. The tumor induction frequency was calculated by Kaplan-Meier analysis. The incidence of tumors from 50 Gy of 45 keV/μm carbon ions was marginally higher than those from 50 Gy of gamma rays. However, 60 Gy of 15 keV/μm carbon ions induced significantly fewer tumors than did gamma rays. RBE values of 0.87 + 0.12, 1.29 + 0.08 or 2.06 + 0.39 for lifetime tumorigenesis were calculated for 15, 45 or 75 keV/μm carbon-ion beams, respectively. Fibrosarcoma predominated, with no Linear Energy Transfer (LET)-dependent differences in the tumor histology. Experiments measuring the late effect of leg skin shrinkage suggested that the carcinogenic damage of 15 keV/μm carbon ions would be less than that of gamma rays. We conclude that patients receiving radiation doses to their normal tissues would face less risk of secondary tumor induction by carbon ions of intermediate LET values compared to equivalent doses of photons.

  11. Evaluation of beam delivery and ripple filter design for non-isocentric proton and carbon ion therapy.

    Science.gov (United States)

    Grevillot, L; Stock, M; Vatnitsky, S

    2015-10-21

    This study aims at selecting and evaluating a ripple filter design compatible with non-isocentric proton and carbon ion scanning beam treatment delivery for a compact nozzle. The use of non-isocentric treatments when the patient is shifted as close as possible towards the nozzle exit allows for a reduction in the air gap and thus an improvement in the quality of scanning proton beam treatment delivery. Reducing the air gap is less important for scanning carbon ions, but ripple filters are still necessary for scanning carbon ion beams to reduce the number of energy steps required to deliver homogeneous SOBP. The proper selection of ripple filters also allows a reduction in the possible transverse and depth-dose inhomogeneities that could appear in non-isocentric conditions in particular. A thorough review of existing ripple filter designs over the past 16 years is performed and a design for non-isocentric treatment delivery is presented. A unique ripple filter quality index (QIRiFi) independent of the particle type and energy and representative of the ratio between energy modulation and induced scattering is proposed. The Bragg peak width evaluated at the 80% dose level (BPW80) is proposed to relate the energy modulation of the delivered Bragg peaks and the energy layer step size allowing the production of homogeneous SOBP. Gate/Geant4 Monte Carlo simulations have been validated for carbon ion and ripple filter simulations based on measurements performed at CNAO and subsequently used for a detailed analysis of the proposed ripple filter design. A combination of two ripple filters in a series has been validated for non-isocentric delivery and did not show significant transverse and depth-dose inhomogeneities. Non-isocentric conditions allow a significant reduction in the spot size at the patient entrance (up to 350% and 200% for protons and carbon ions with range shifter, respectively), and therefore in the lateral penumbra in the patients.

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

    International Nuclear Information System (INIS)

    Inaji, Motoki; Okauchi, Takashi; Nagai, Yuji; Nojima, Kumie

    2003-01-01

    The present study was designed to make better Parkinson model animal and evaluate the transplantation treatment with ES cell. In the first year, we irradiated left striatum of adult rats with charged carbon particles (290 MeV/nucleon, 5 mm spread-out Bragg peak, 100 Gy) for purpose of making Parkinson model rats. At 4, 8, 12 weeks after the irradiation, we performed the rotation test to methamphetamine and the autoradiography on dopamine D2 receptor and transporter using 11 C-raclopride and 11 C-PE2I to measure the effects of the irradiation. As a result, the number of rotation increased and the distributions of dopamine D2 receptor and transporter in the striatum decreased during the time after the irradiation. These results suggested that the secondary neural damage due to the vascular degeneration caused the progressive destruction of dopamine system. To make more stable Parkinson model rats, we need to use smaller collimator and develop the accurate stereotactic irradiation system in the further research. (author)

  13. Evaluation of the relative biological effectiveness of carbon ion beams in the cerebellum using the rat organotypic slice culture system

    International Nuclear Information System (INIS)

    Yoshida, Yukari; Katoh, Hiroyuki; Nakano, Takashi; Suzuki, Yoshiyuki; Al-Jahdari, Wael S.; Shirai, Katsuyuki; Hamada, Nobuyuki; Funayama, Tomoo; Sakashita, Tetsuya; Kobayashi, Yasuhiko

    2012-01-01

    The purpose of this study was to clarify the relative biological effectiveness (RBE) values of carbon ion (C) beams in normal brain tissues, a rat organotypic slice culture system was used. The cerebellum was dissected from 10-day-old Wistar rats, cut parasagittally into approximately 600-μm-thick slices and cultivated using a membrane-based culture system with a liquid-air interface. Slices were irradiated with 140 kV X-rays and 18.3 MeV/amu C-beams (linear energy transfer=108 keV/μm). After irradiation, the slices were evaluated histopathologically using hematoxylin and eosin staining, and apoptosis was quantified using the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Disorganization of the external granule cell layer (EGL) and apoptosis of the external granule cells (EGCs) were induced within 24 h after exposure to doses of more than 5 Gy from C-beams and X-rays. In the early postnatal cerebellum, morphological changes following exposure to C-beams were similar to those following exposure to X-rays. The RBEs values of C-beams using the EGL disorganization and the EGC TUNEL index endpoints ranged from 1.4 to 1.5. This system represents a useful model for assaying the biological effects of radiation on the brain, especially physiological and time-dependent phenomena. (author)

  14. Preparation of carbon 11-labelled radiopharmaceuticals by the use of HPLC method

    International Nuclear Information System (INIS)

    Berget, G.; Maziere, M.; Godot, J.M.; Sastre, J.; Prenant, C.; Comar, D.

    1982-06-01

    Various medical examinations and metabolic studies are carried out with carbon 11-labelled radiopharmaceuticals. This radioelement offers a number of advantages: it can be introduced into an organic molecule without changing its properties; the radiation dose delivered to the patient is low (T = 20 mn); since the specific activity obtained is high (0.5 to 2 Ci/μ mole) the injected masses are very small; finally, tomographic images of the distribution of the product in the body may be obtained by the use of positron cameras. However in view of the radioactivities handled on a routine basis the preparations must be carried out without manual intervention, in closed shielded hoods. Synthesis methods and special equipment have been developed. In all cases the reaction mixtures are purified by HPLC, a method chosen for its speed, efficiency, ease of automation and adaptation to any product with a suitable choice of column and eluant. The radiopharmaceuticals are obtained in injectable solution (ethanol-physiological serum, buffered physiological serum) or in a mixture of volatile solvents which are evaporated by nitrogen bubbling and finally sterilised by passage over millipore filter. About ten different radiopharmaceuticals are prepared in this way in the laboratory [fr

  15. Chiral dimethylamine flutamide derivatives-modeling, synthesis, androgen receptor affinities and carbon-11 labeling

    International Nuclear Information System (INIS)

    Jacobson, Orit; Laky, Desideriu; Carlson, Kathryn E.; Elgavish, Sharona; Gozin, Michael; Even-Sapir, Einat; Leibovitc, Ilan; Gutman, Mordechai; Chisin, Roland; Katzenellenbogen, John A.; Mishani, Eyal

    2006-01-01

    Most prostate cancers are androgen dependent upon initial diagnosis. On the other hand, some very aggressive forms of prostate cancer were shown to have lost the expression of the androgen receptor (AR). Although the AR is routinely targeted in endocrine treatment, the clinical outcome remains suboptimal. Therefore, it is crucial to demonstrate the presence and activity of the AR in each case of prostate cancer, before and after treatment. While noninvasive positron emission tomography (PET) has the potential to determine AR expression of tumor cells in vivo, fully optimized PET imaging agents are not yet available. Based on molecular modeling, three novel derivatives of hydroxyflutamide (Compounds 1-3) were designed and synthesized. They contain an electron-rich group (dimethylamine) located on the methyl moiety, which may confer a better stability to the molecule in vivo. Compounds 1-3 have AR binding that is similar or higher than that of the currently used commercial drugs. An automated carbon-11 radiolabeling route was developed, and the compounds were successfully labeled with a 10-15% decay-corrected radiochemical yield, 99% radiochemical purity and a specific activity of 4Ci/μmol end of bombardment (n=15). These labeled biomarkers may facilitate the future quantitative molecular imaging of AR-positive prostate cancer using PET and may also allow for image-guided treatment of prostate cancer

  16. Radiation protection problems in a laboratory for the labelling of molecules with carbon-11

    International Nuclear Information System (INIS)

    Vialettes, H.; Moreau, A.

    1980-03-01

    This paper shows that the qualities of carbon-11, especially its short half-life, which suit it so well for the labelling of radiopharmaceuticals prove to be a great handicap in the preparation of these substances. The operator has to make a fresh preparation for each examination and start with strong radioactivities (200 to 500 mCi) in order to obtain an adequate injected activity at the end of the process, the absorbed dose averaging 1.5 man-rem per manipulation at the fingertips. The development of an automatic preparation method involving as little manual interference as possible has halved the collective dose for twice the dose handled. The labelling of molecules used for diagnosis is now considered to take place under satisfactory radioprotection conditions. The fingertip irradiations are analysed in the light of CIPR recommendations, while regretting that in publication 26 this problem of partial external irradiation of the skin is not dealt with as clearly and precisely as before [fr

  17. Propionyl-l-carnitine: Labelling in the N-methyl position with Carbon-11 and pharmacokinetic studies in rats

    International Nuclear Information System (INIS)

    Davenport, Raymond J.; Law, Marilyn P.; Pike, Victor W.; Osman, Safiye; Poole, Keith G.

    1995-01-01

    The prospective therapeutic, propionyl-l-carnitine, was labelled in the N-methyl position with the positron-emitter, carbon-11 (t (1(2)) = 20.4 min), with a view to studying its pharmacokinetics in humans using PET. Labelling was achieved by methylating nor-propionyl-l-carnitine hydrochloride with no-carrier-added [ 11 C]iodomethane (produced from cyclotron-produced [ 11 C]carbon dioxide) in ethanol in the presence of 1,2,2,6,6,-pentamethylpiperidine. HPLC of the reaction mixture on a strong cation exchange column provided high purity [N-methyl- 11 C]propionyl-l-carnitine in 62% radiochemical yield (decay-corrected from [ 11 C]iodomethane), ready for intravenous administration within 35 min from the end of radionuclide production. [N-methyl- 11 C]Propionyl-l-carnitine, given intravenously to rats, cleared rapidly from plasma. A slow uptake of radioactivity into myocardium and striated muscle was observed. In plasma, unchanged tracer represented 84% of the radioactivity at 2.5 min and 2.5% of the radioactivity at 60 min. In heart, unchanged tracer represented 18% of radioactivity at 2.5 min and 2.4% at 15 min. The remainder of radioactivity detected in plasma and heart was identified as [N-methyl- 11 C]l-carnitine and [N-methyl- 11 C]acetyl-l-carnitine

  18. Regional myocardial oxygen consumption estimated by carbon-11 acetate and positron emission tomography before and after repetitive ischemia

    DEFF Research Database (Denmark)

    Kofoed, K F; Hansen, P R; Holm, S

    2011-01-01

    Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short episodes of acu...

  19. Characterization of a Gas-Purge Method to Access 11C-Carbon-Dioxide Radioactivity in Blood

    International Nuclear Information System (INIS)

    Ng, Y.; Green, M.A.

    2014-01-01

    Carbon-11 (t 1/2 : 20 minutes) labeled radiotracers, such as 11 C-acetate and 11 C-palmitate are widely used in positron emission tomography (PET) for noninvasive evaluation of myocardial metabolism under varied physiological conditions. These tracers are attractive probes of tissue physiology, because they are simply radiolabeled versions of the native biochemical substrates. One of the major metabolites generated by these tracers upon the administration is 11 CO 2 produced via the citric acid cycle. In quantitative modeling of 11 C-acetate and 11 C-palmitate PET data, the fraction of blood 11 C radioactivity present as 11 CO 2 needs to be measured to obtain a correct radiotracer arterial input function. Accordingly, the literature describes a method whereby the total blood 11 C-activity is counted in blood samples treated with base solution, while the fraction of 11 CO 2 is measured after the blood is treated with acid followed by a 10 minutes gas-purge. However, a detailed description of the experimental validation of this method was not provided. The goal of this study was to test the reliability of a 10-minute gas purging method used to assay 11 CO 2 radioactivity in blood. (author)

  20. Synthesis of suicide inhibitors of monoamine oxidase: carbon-11 labeled clorgyline, L-deprenyl and D-deprenyl

    International Nuclear Information System (INIS)

    MacGregor, R.R.; Fowler, J.S.; Wolf, A.P.; Halldin, C.; Langstroem, B.

    1988-01-01

    The suicide inhibitors of monoamine oxidase type A and B, clorgyline and L-deprenyl have been labeled with carbon-11 by [ 11 C]methylation of the norbases with [ 11 C]H 3 I. The less active enantiomer of deprenyl (D-deprenyl) was also labeled using this procedure. The synthesis time was 35 minutes, the radiochemical yield was 25-40% and the specific activity was 0.8-2.0 Ci/μmol (calculated to EOB). Procedures for synthesis of the precursor norbases as well as the synthesis of unlabeled clorgyline, L-deprenyl and D-deprenyl are given. (author)

  1. Positron emission tomography shows high specific uptake of racemic carbon-11 labelled norepinephrine in the primate heart

    International Nuclear Information System (INIS)

    Farde, L.; Halldin, C.; Naagren, K.; Suhara, Tetsuya; Karlsson, P.; Schoeps, K.O.; Swahn, C.G.; Bone, D.

    1994-01-01

    (-)-Norepinephrine is the predominant neurotransmitter of the sympathetic innervation of the heart. Racemic norepinephrine was labelled with carbon-11 and injected i.v. into Cynomolgus monkeys. Five minutes after injection there was a more than tenfold higher radioactivity in the heart than in adjacent tissue. Pretreatment with the norepinephrine reuptake inhibitor desipramine reduced the uptake by more than 80%. The high specific uptake of racemic [ 11 C]norepinephrine indicates that enatiomerically pure(-)-[ 11 C]norepinephrine has promising potential for detailed mapping of the sympathetic innervation of the human myocardium. (orig.)

  2. Positron emission tomography shows high specific uptake of racemic carbon-11 labelled norepinephrine in the primate heart

    Energy Technology Data Exchange (ETDEWEB)

    Farde, L [Dept. of Clinical Neuroscience, Karolinska Inst., Stockholm (Sweden); Halldin, C [Dept. of Clinical Neuroscience, Karolinska Inst., Stockholm (Sweden); Naagren, K [Turku Univ., Cyclotron/PET Center (Finland); Suhara, Tetsuya [Dept. of Clinical Neuroscience, Karolinska Inst., Stockholm (Sweden); Karlsson, P [Dept. of Clinical Neuroscience, Karolinska Inst., Stockholm (Sweden); Schoeps, K O [Dept. of Clinical Neuroscience, Karolinska Inst., Stockholm (Sweden); Swahn, C G [Dept. of Clinical Neuroscience, Karolinska Inst., Stockholm (Sweden); Bone, D [Dept. of Clinical Neuroscience, Karolinska Inst., Stockholm (Sweden)

    1994-04-01

    (-)-Norepinephrine is the predominant neurotransmitter of the sympathetic innervation of the heart. Racemic norepinephrine was labelled with carbon-11 and injected i.v. into Cynomolgus monkeys. Five minutes after injection there was a more than tenfold higher radioactivity in the heart than in adjacent tissue. Pretreatment with the norepinephrine reuptake inhibitor desipramine reduced the uptake by more than 80%. The high specific uptake of racemic [[sup 11]C]norepinephrine indicates that enatiomerically pure(-)-[[sup 11]C]norepinephrine has promising potential for detailed mapping of the sympathetic innervation of the human myocardium. (orig.)

  3. Reinforced concrete T-beams externally prestressed with unbonded carbon fiber-reinforced polymer tendons

    DEFF Research Database (Denmark)

    Bennitz, Anders; Nilimaa, Jonny; Täljsten, Björn

    2012-01-01

    force, and the presence of a deviator were investigated. The results were compared to those observed with analogous beams prestressed with steel tendons, common beam theory, and predictions made using an analytical model adapted from the literature. It was found that steel and CFRP tendons had very...... similar effects on the structural behavior of the strengthened beams; the minor differences that were observed are attributed to the difference between the modulus of elasticity of the CFRP and the steel used in the tests. The models predicted the beams' load-bearing behavior accurately but were less...

  4. Radiosynthesis of [11C]D.P.A.-713, [11C]D.P.A.-715 and [11C]clinme, selected carbon-11-labelled novel potential radioligands for imaging the peripheral benzodiazepine receptors with PET

    International Nuclear Information System (INIS)

    Dolle, F.; Thominiaux, C.; Hinnen, F.; Demphel, S.; Le helleix, S.; Chauveau, F.; Boutin, H.; Herard, A.S.; Hantraye, P.; Tavitian, B.; Kassiou, M.; James, M.; Creelman, A.; Fulton, R.; Kassiou, M.; Katsifis, A.; Greguric, I.; Mattner, F.; Loch, C.; Selleri, S.

    2008-01-01

    11 C P.K.11195 is not only the oldest, but also the most widely used PET radiotracer for in vivo imaging of the peripheral benzodiazepine receptors (P.B.R. or translocator protein (18 kDa, T.S.P.O.). With the aim of developing a new PET imaging probe for the in vivo study of the P.B.R., two pyrazol [1,5-a]pyrimidineacetamides (D.P.A.-713 and D.P.A.-715) and one imidazol[1,2-a]pyridine-acetamide (C.L.I.N.M.E.) were radiolabelled with the positron emitters carbon 11 (half life: 20.38 min) [1-5]. Briefly, C.L.I.N.M.E. (2-[6-chloro-2(4-iodophenyl)-imidazol[1,2-a]pyridin-3-yl] -N-ethyl-N-methyl-acetamide) was labelled at its methyl-acetamide moity chain from the corresponding nor-analogue using[ 11 C]methyl iodide (in D.M.S.O./D.M.F (100/200 μL) containing powdered K.O.H. (3-5 mg) at 110 degrees C for 3 min. D.P.A.-713 (N,N-diethyl-2-[2-(4-methoxy-phenyl)-5,7-dimethyl-pyrazolo[1,5-a]pyrimidin -3-yl]acetamide) and D.P.A.-715 (N,N-diethyl-2-[2-(4-methoxy-phenyl)-5,7-bis-tri-fluoro-methyl-pyrazolo [1,5-a]pyrimidin-3-yl]acetamide) were labelled at their aromatic methoxy groups from the corresponding nor-derivatives using [ 11 C]methyl triflate (in acetone (300μL) containing aq. 3 M NaOH (4μL) at 110 degrees C for 1 min). All radioligands were purified using semi preparative Zorbax reverse phase H.P.L.C., were adequately formulated for in vivo injection within 30 min and were found to be > 95% chemically and radiochemically pure. (N.C.)

  5. Radiosynthesis of [{sup 11}C]D.P.A.-713, [{sup 11}C]D.P.A.-715 and [{sup 11}C]clinme, selected carbon-11-labelled novel potential radioligands for imaging the peripheral benzodiazepine receptors with PET

    Energy Technology Data Exchange (ETDEWEB)

    Dolle, F.; Thominiaux, C.; Hinnen, F.; Demphel, S.; Le helleix, S.; Chauveau, F.; Boutin, H.; Herard, A.S.; Hantraye, P.; Tavitian, B. [Service Hospitalier Frederic Joliot, I2BM/DSV, 91 - Orsay (France); Kassiou, M.; James, M.; Creelman, A.; Fulton, R. [Sydney Univ., Brain and Mind Research Institute, NSW (Australia); Kassiou, M. [Sydney Univ., Discipline of Medical Radiations, Sciences and School of Chemistry, NSW (Australia); Katsifis, A.; Greguric, I.; Mattner, F.; Loch, C. [Radiopharmaceuticals Research Institute, ANSTO, NSW (Australia); Selleri, S. [Degli Studi di Firenze Univ., Dipt. di Scienze Farmaceutiche (Italy)

    2008-02-15

    {sup 11}C P.K.11195 is not only the oldest, but also the most widely used PET radiotracer for in vivo imaging of the peripheral benzodiazepine receptors (P.B.R. or translocator protein (18 kDa, T.S.P.O.). With the aim of developing a new PET imaging probe for the in vivo study of the P.B.R., two pyrazol [1,5-a]pyrimidineacetamides (D.P.A.-713 and D.P.A.-715) and one imidazol[1,2-a]pyridine-acetamide (C.L.I.N.M.E.) were radiolabelled with the positron emitters carbon{sup 11} (half life: 20.38 min) [1-5]. Briefly, C.L.I.N.M.E. (2-[6-chloro-2(4-iodophenyl)-imidazol[1,2-a]pyridin-3-yl] -N-ethyl-N-methyl-acetamide) was labelled at its methyl-acetamide moity chain from the corresponding nor-analogue using[{sup 11}C]methyl iodide (in D.M.S.O./D.M.F (100/200 {mu}L) containing powdered K.O.H. (3-5 mg) at 110 degrees C for 3 min. D.P.A.-713 (N,N-diethyl-2-[2-(4-methoxy-phenyl)-5,7-dimethyl-pyrazolo[1,5-a]pyrimidin -3-yl]acetamide) and D.P.A.-715 (N,N-diethyl-2-[2-(4-methoxy-phenyl)-5,7-bis-tri-fluoro-methyl-pyrazolo [1,5-a]pyrimidin-3-yl]acetamide) were labelled at their aromatic methoxy groups from the corresponding nor-derivatives using [{sup 11}C]methyl triflate (in acetone (300{mu}L) containing aq. 3 M NaOH (4{mu}L) at 110 degrees C for 1 min). All radioligands were purified using semi preparative Zorbax reverse phase H.P.L.C., were adequately formulated for in vivo injection within 30 min and were found to be > 95% chemically and radiochemically pure. (N.C.)

  6. Synthesis and preliminary evaluation of carbon-11-meta-hydroxyephedrine: A false transmitter agent for heart neuronal imaging

    International Nuclear Information System (INIS)

    Rosenspire, K.C.; Haka, M.S.; Van Dort, M.E.; Jewett, D.M.; Gildersleeve, D.L.; Schwaiger, M.; Wieland, D.M.

    1990-01-01

    Carbon-11-meta-hydroxyephedrine is a new radiotracer developed for mapping the sympathetic nerves of the heart. Carbon-11-meta-hydroxyephedrine is synthesized by direct N-methylation of metaraminol with [ 11 C]methyl iodide in dimethyl formamide/dimethyl sulfoxide and purified by semi-preparative reversed-phase HPLC. Total synthesis time is 45 min from end-of-bombardment. Carbon-11-meta-hydroxyephedrine is produced in 40%-50% corrected radiochemical yield with a specific activity of 900 Ci/mmol. Routine radiochemical and chemical purity are 95% and 98%, respectively. Biodistribution studies in rats show high myocardial uptake. Pretreatment with desipramine, a drug known to selectively block neuronal uptake, results in a 92% decrease in tracer accumulation in the myocardium. Metabolic studies in guinea pigs show less than 5% metabolites in heart tissue 30 min after intravenous injection suggesting that [ 11 C]meta-hydroxyephedrine is suitable for kinetic modeling. These preliminary results support this new tracer as a clinical agent for neuronal imaging of the heart

  7. EXPERIMENTAL EVALUATION OF DOSIMETRIC CHARACTERIZATION OF GAFCHROMIC EBT3 AND EBT-XD FILMS FOR CLINICAL CARBON ION BEAMS.

    Science.gov (United States)

    Yonai, Shunsuke; Arai, Chinatsu; Shimoyama, Kaoru; Fournier-Bidoz, Nathalie

    2018-02-03

    Radiochromic film is a very useful tool for 2D dosimetric measurements in radiotherapy because it is self-developing and has very high-spatial resolution. However, considerable care has to be taken in ion beam radiotherapy owing to the quenching effect of high-linear energy transfer (LET) radiation. In this study, the dose responses of GAFchromic EBT3 and EBT-XD films were experimentally investigated using the clinical carbon ion beam at the Heavy Ion Medical Accelerator in Chiba. Results showed that the relations between absorbed dose and net optical density could be expressed well using an equation proposed by Reinhardt (2015). The quenching effect was evaluated by determining their relative efficiencies for photon irradiation as a function of LET. A correction equation derived in this study allowed the absorbed dose to be determined in the small irradiation field used for carbon ion radiotherapy eye treatments. This study contributes to establishing an absolute dosimetry procedure for heavy ion beams using radiochromic film. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. The Properties of SBR/ENR50 Blend Containing Nanoclay/Carbon Black Dual Filler System Cured by Electron Beam

    Directory of Open Access Journals (Sweden)

    Sima Ahmadi-Shooli

    2017-05-01

    Full Text Available Nanocomposites based on an SBR/ENR50 rubber blend with the blend ratio of 50/50 using Cloisite 15A nanoclay (5 and 10 phr and carbon black (20 phr were prepared by melt mixing process. The rubber compounds were crosslinked by electron beam irradiation process at 50 and 100 kGy doses. A reference sample containing carbon black at 35 phr was prepared using a conventional sulphur curing system. The gel content of the samples was specified using gel fraction measurement. The results showed the maximum gel content for the sample having 5 phr nanoclay and 20 phr carbon black. The dynamic mechanical properties, including the storage modulus, loss modulus, and loss factor, of the nanocomposites were evaluated using dynamic mechanical analysis (DMA tests. The results indicated that, in spite of a well dispersed nanoclay in samples containing 10 phr nanoclay and 20 phr carbon black, a minimum loss factor was observed in the sample containing 5 phr nanoclay and 20 phr carbon black at 100 kGy. On the other hand, the storage modulus of the reference sample was found to be higher than that of the sample with 5 phr nanoclay and 20 phr carbon black. The mechanical properties, including the tensile strength, stress at 100%, 200%, and 300% elongation and the percentage of elongation were measured by a tensile machine. The results showed an increase in tensile strength and the stress at different elongations for a sample with 5 phr nanoclay and 20 phr carbon black compared to the reference sample. In the corresponding SEM images of the samples having nanoclay and carbon black irradiated at 100 kGy a significantly higher surface roughness was observed.

  9. Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

    Directory of Open Access Journals (Sweden)

    N. Simos

    2016-11-01

    Full Text Available A comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have been studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences ≥5×10^{20}  p/cm^{2}. The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (∼5×10^{18}

  10. Assessing and ameliorating the influence of the electron beam on carbon nanotube oxidation in environmental transmission electron microscopy

    International Nuclear Information System (INIS)

    Koh, Ai Leen; Sinclair, Robert

    2017-01-01

    In this work, we examine how the imaging electron beam can induce damage in carbon nanotubes (CNTs) at varying oxygen gas pressures and electron dose rates using environmental transmission electron microscopy (ETEM). Our studies show that there is a threshold cumulative electron dose which brings about damage in CNTs in oxygen – through removal of their graphitic walls – which is dependent on O_2 pressure, with a 4–5 fold decrease in total electron dose per decade increase at a lower pressure range (10"−"6 to 10"−"5 mbar) and approximately 1.3 –fold decrease per decade increase at a higher pressure range (10"−"3 to 10"0 mbar). However, at a given pressure, damage in CNTs was found to occur even at the lowest dose rate utilized, suggesting the absence of a lower limit for the latter parameter. This study provides guidelines on the cumulative dose required to damage nanotubes in the 10"−"7 mbar to 10"0 mbar pressure regimes, and discusses the role of electron dose rate and total electron dose on beam-induced CNT degradation experiments. - Highlights: • The electron beam ionizes gas molecules in ETEM and affects experimental outcomes. • Beam-induced damage in CNTs occurs at varying O_2 pressures and electron dose rates. • There is a threshold cumulative dose to damage CNTs which depends on O_2 pressure. • At a given pressure, CNT damage occurs even at the electron dose rate utilized.

  11. In vivo evaluation of carbon-11-labelled non-sarcosine-based glycine transporter 1 inhibitors in mice and conscious monkeys

    Energy Technology Data Exchange (ETDEWEB)

    Toyohara, Jun [Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan 260-8670 (Japan); Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan 173-0022 (Japan); Ishiwata, Kiichi; Sakata, Muneyuki [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan 173-0022 (Japan); Wu, Jin [Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan 260-8670 (Japan); Nishiyama, Shingo; Tsukada, Hideo [Central Research Laboratory, Hamamatsu Photonics K.K., Shizuoka, Japan 434-8601 (Japan); Hashimoto, Kenji, E-mail: hashimoto@faculty.chiba-u.j [Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan 260-8670 (Japan)

    2011-05-15

    Introduction: Glycine transporter 1 (GlyT-1) is an attractive target in positron emission tomography (PET) studies. Here, we report the in vivo evaluation of three carbon-11-labelled non-sarcosine-type GlyT-1 inhibitors - [{sup 11}C]SA1, [{sup 11}C]SA2 and [{sup 11}C]SA3 - as novel PET tracers for GlyT-1. Methods: The regional brain distributions of the three compounds in mice were studied at baseline and under receptor-blockade conditions with co-injection of carrier loading or pretreatment with an excess of selective GlyT-1 inhibitors (ALX-5407 and SSR504734). Metabolic stability was investigated by radio high-performance liquid chromatography. Dynamic PET scans in conscious monkeys were performed with/without selective GlyT-1 inhibitors. Results: The IC{sub 50} values of SA1, SA2 and SA3 were 9.0, 6400 and 39.7 nM, respectively. The regional brain uptakes of [{sup 11}C]SA1 and [{sup 11}C]SA3 in mice were heterogeneous and consistent with the known distribution of GlyT-1. [{sup 11}C]SA2 showed low and homogeneous uptake in the brain. Most radioactivity in the brain was detected in unchanged form, although peripherally these compounds were degraded. Carrier loading decreased the uptake of [{sup 11}C]SA1 in GlyT-1-rich regions. However, similar reductions were not observed with [{sup 11}C]SA3. Pretreatment with ALX-5407 decreased the uptake of [{sup 11}C]SA1 in GlyT-1-rich regions. In the monkey at baseline, regional brain uptake of [{sup 11}C]SA1 was heterogeneous and consistent with the known GlyT-1 distribution. Pretreatment with selective GlyT-1 inhibitors significantly decreased the distribution volume ratio of [{sup 11}C] SA1 in GlyT-1-rich regions. Conclusions: [{sup 11}C]SA1 has the most suitable profile among the three carbon-11-labelled GlyT-1 inhibitors. Lead optimization of [{sup 11}C]SA1 structure will be required to achieve in vivo selective GlyT-1 imaging.

  12. In vivo evaluation of carbon-11-labelled non-sarcosine-based glycine transporter 1 inhibitors in mice and conscious monkeys

    International Nuclear Information System (INIS)

    Toyohara, Jun; Ishiwata, Kiichi; Sakata, Muneyuki; Wu, Jin; Nishiyama, Shingo; Tsukada, Hideo; Hashimoto, Kenji

    2011-01-01

    Introduction: Glycine transporter 1 (GlyT-1) is an attractive target in positron emission tomography (PET) studies. Here, we report the in vivo evaluation of three carbon-11-labelled non-sarcosine-type GlyT-1 inhibitors - [ 11 C]SA1, [ 11 C]SA2 and [ 11 C]SA3 - as novel PET tracers for GlyT-1. Methods: The regional brain distributions of the three compounds in mice were studied at baseline and under receptor-blockade conditions with co-injection of carrier loading or pretreatment with an excess of selective GlyT-1 inhibitors (ALX-5407 and SSR504734). Metabolic stability was investigated by radio high-performance liquid chromatography. Dynamic PET scans in conscious monkeys were performed with/without selective GlyT-1 inhibitors. Results: The IC 50 values of SA1, SA2 and SA3 were 9.0, 6400 and 39.7 nM, respectively. The regional brain uptakes of [ 11 C]SA1 and [ 11 C]SA3 in mice were heterogeneous and consistent with the known distribution of GlyT-1. [ 11 C]SA2 showed low and homogeneous uptake in the brain. Most radioactivity in the brain was detected in unchanged form, although peripherally these compounds were degraded. Carrier loading decreased the uptake of [ 11 C]SA1 in GlyT-1-rich regions. However, similar reductions were not observed with [ 11 C]SA3. Pretreatment with ALX-5407 decreased the uptake of [ 11 C]SA1 in GlyT-1-rich regions. In the monkey at baseline, regional brain uptake of [ 11 C]SA1 was heterogeneous and consistent with the known GlyT-1 distribution. Pretreatment with selective GlyT-1 inhibitors significantly decreased the distribution volume ratio of [ 11 C] SA1 in GlyT-1-rich regions. Conclusions: [ 11 C]SA1 has the most suitable profile among the three carbon-11-labelled GlyT-1 inhibitors. Lead optimization of [ 11 C]SA1 structure will be required to achieve in vivo selective GlyT-1 imaging.

  13. Development of new and improved labelling procedures for introducing isotopic hydrogen and carbon-11 into organic compounds

    International Nuclear Information System (INIS)

    Al-Qahtani, M.H.S.

    1999-10-01

    New and improved methods for introducing radioisotopic hydrogen (tritium) and carbon (positron-emitting short-lived carbon-11, t 1/ 2 = 20.4 min) into organic molecules for application in biological research have been explored. In Chapter 1 the applications of radioactive isotopes in biological and clinical research is surveyed, with particular emphasis on the value of β-emitting tritium and positron-emitting carbon-11. In Chapter 2 we report the use of the non-radioactive hydrogen isotope, deuterium, as a surrogate for tritium in the development of microwave-enhanced labelling procedures, based on catalytic hydrogen transfer to olefins (e.g. styrene, styrene derivatives, cinnamic acid and its derivatives). Hydrogen or deuterium donors (e.g. formate salts) were used alone or in combination with other sources (e.g. D 2 O). The method was found to give fully hydrogenated products using very short microwave irradiation times (∼ 2 min) and was highly reproducible. Importantly, the method is environmentally clean, as when extended to tritiated formates little or no radioactive waste is produced. In Chapter 3 we explored the labelling of CGP 62349 {3-[1-(R)-[3-(4-methoxybenzyl)phosphinyl-2-(S)-hydroxy-propyl- amino]ethyl]benzoic acid}, a γ-aminobutyric acid type B (GABA B ) receptor antagonist, with carbon-11 in order to provide a prospective radioligand for medical imaging with positron emission tomography (PET). Labelling agents, [ 11 C]iodomethane and [ 11 C]methyl triflate, prepared by improved methods, were used in the rapid methylation of desmethyl-CGP 62349. Substantially higher radiochemical yields (78%) of [ 11 C]CGP 62349 were achieved by the new methods compared to that produced in a previously published procedure (9%). In addition, the use of [ 11 C]methyl triflate rather than [ 11 C]iodomethane has the advantage of giving a high radiochemical yield and a lower amount of carrier. In Chapter 4 we report on the use of [ 11 C]carbon monoxide as a labelling

  14. 11 things a geologist thinks an engineer should know about carbonate beaches

    Science.gov (United States)

    Halley, Robert B.; Magoon, Orville T.; Robbins, Lisa L.; Ewing, Lesley

    2002-01-01

    This is a review of the geological aspects of carbonate beaches that a geologist thinks may be useful for an engineer. Classical geologic problems of carbonate beaches, for example how ancient examples are recognized in rock sequences, are of little interest to engineers. Geologists not involved in engineering problems may find it difficult to know what an engineer should understand about carbonate beaches. Nevertheless, there are at least eleven topics that are potentially very useful for engineers to keep in mind. These eleven are chosen with as much thought going into what has been omitted as has been given to the eleven included topics. Some qualifications are in order: First, this paper does not discuss certain kinds of carbonate shorelines that are beyond the scope of engineering issues. For example, this review does not discuss very high-energy carbonate boulder beaches. These beaches are comprised of pieces of carbonate material ganging in size from ten centimeters to meters. Typically, these are high-energy storm deposits formed from pieces of either eroded carbonate rock or other large carbonate pieces such as pieces of large corals. This paper focuses on sand-sized (0.0625–2.0 mm) coastal carbonate deposits. Second, offshore beaches will not be discussed. There are many carbonate beaches that form on banks or shoals exposed at low tide, but our discussion is confined to what most people think of when they go to some tropical island and/or resort and walk out to lay on the beach. Third, this paper does not consider mixed carbonate/quartz sand beaches. While mixed beaches are common, only the end member of purely carbonate sand beaches is considered. Fourth, there will be no order of preference of the eleven topics. And lastly, these eleven topics are not consensus items. These are simply one geologist s thoughts about the aspects of carbonate beaches that would be useful for engineering colleagues to keep in mind. Where possible, general reference is

  15. Determination of the beam-spin asymmetry of deuteron photodisintegration in the energy region Eγ=1.1 -2.3 GeV

    Science.gov (United States)

    Zachariou, N.; Ilieva, Y.; Berman, B. L.; Ivanov, N. Ya.; Sargsian, M. M.; Avakian, R.; Feldman, G.; Nadel-Turonski, P.; Adhikari, K. P.; Adikaram, D.; Anderson, M. D.; Pereira, S. Anefalos; Avakian, H.; Badui, R. A.; Baltzell, N. A.; Battaglieri, M.; Baturin, V.; Bedlinskiy, I.; Biselli, A. S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Cao, T.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dupre, R.; Egiyan, H.; Alaoui, A. El; Fassi, L. El; Elouadrhiri, L.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Forest, T. A.; Fradi, A.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Hafidi, K.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Ho, D.; Holtrop, M.; Hughes, S. M.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jiang, H.; Jo, H. S.; Joo, K.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mattione, P. T.; McKinnon, B.; Mineeva, T.; Mirazita, M.; Mokeeev, V. I.; Montgomery, R. A.; Moutarde, H.; Camacho, C. Munoz; Net, L. A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Phelps, W.; Phillips, J. J.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Senderovich, I.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D.; Wei, X.; Wood, M. H.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

    2015-05-01

    The beam-spin asymmetry, Σ , for the reaction γ d →p n has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, θc .m ., between 25∘ and 160∘. These are the first measurements of beam-spin asymmetries at θc .m .=90∘ for photon-beam energies above 1.6 GeV, and the first measurements for angles other than θc .m .=90∘ . The angular and energy dependence of Σ is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.

  16. Carbon-11 choline or FDG-PET for staging of oesophageal cancer?

    International Nuclear Information System (INIS)

    Jager, P.L.; Que, T.H.; Vaalburg, W.; Pruim, J.; Elsinga, P.; Plukker, J.T.

    2001-01-01

    We investigated the feasibility of using carbon-11 choline (CHOL) positron emission tomography (PET) for the staging of oesophageal cancer, in comparison with fluorine-18 fluorodeoxyglucose (FDG) PET, using histopathological findings as the gold standard. Eighteen patients were studied: 16 patients with cancer of the oesophagus or gastro-oesophageal junction and two with in situ carcinoma/high-grade dysplasia. PET imaging was performed 5 min (CHOL) or 90 min (FDG) after injection of 370 MBq of the tracer. PET images were analysed by two independent and blinded physicians using visual and standardised uptake value (SUV) analysis. PET results were compared with surgical and histopathological findings. FDG-PET was able to detect all (100%) of the 16 malignant primary lesions, while CHOL-PET detected 73%. In situ carcinoma (n=1) and high-grade dysplasia (n=1) were not visualised with either tracer. Diffuse uptake of the tracers was noted in areas of Barrett's oesophagitis. Twelve patients had locoregional metastases (N1) that were not detected with either FDG or CHOL. Six patients had additional distant nodal (M1a) metastases; four of six (66%) were visualised by FDG, and three of five (60%) by CHOL-PET. On a lesion basis, FDG-PET detected 10/12 non-regional metastases (sensitivity 83%), while CHOL-PET detected 5/12 (sensitivity 42%). Haematogenous distant metastases (M1b) were positive on FDG-PET in three of four patients, and on CHOL-PET in two of four. SUV values were significantly higher for FDG (FDG 6.6±3.5, CHOL 5.5±2.5, P=0.04). CHOL-PET is able to visualise oesophageal carcinoma and its metastases, but appears to be inferior to FDG-PET. Presumably this is the result of lower tumoural uptake and considerable non-specific uptake of CHOL in liver, stomach wall, pancreas and small intestine. Further studies are needed to confirm these data. (orig.)

  17. Carbon-11 choline or FDG-PET for staging of oesophageal cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Jager, P.L.; Que, T.H.; Vaalburg, W.; Pruim, J.; Elsinga, P. [PET Centre, Groningen Univ. Hospital (Netherlands); Plukker, J.T. [Dept. of Surgical Oncology, Groningen University Hospital (Netherlands)

    2001-12-01

    We investigated the feasibility of using carbon-11 choline (CHOL) positron emission tomography (PET) for the staging of oesophageal cancer, in comparison with fluorine-18 fluorodeoxyglucose (FDG) PET, using histopathological findings as the gold standard. Eighteen patients were studied: 16 patients with cancer of the oesophagus or gastro-oesophageal junction and two with in situ carcinoma/high-grade dysplasia. PET imaging was performed 5 min (CHOL) or 90 min (FDG) after injection of 370 MBq of the tracer. PET images were analysed by two independent and blinded physicians using visual and standardised uptake value (SUV) analysis. PET results were compared with surgical and histopathological findings. FDG-PET was able to detect all (100%) of the 16 malignant primary lesions, while CHOL-PET detected 73%. In situ carcinoma (n=1) and high-grade dysplasia (n=1) were not visualised with either tracer. Diffuse uptake of the tracers was noted in areas of Barrett's oesophagitis. Twelve patients had locoregional metastases (N1) that were not detected with either FDG or CHOL. Six patients had additional distant nodal (M1a) metastases; four of six (66%) were visualised by FDG, and three of five (60%) by CHOL-PET. On a lesion basis, FDG-PET detected 10/12 non-regional metastases (sensitivity 83%), while CHOL-PET detected 5/12 (sensitivity 42%). Haematogenous distant metastases (M1b) were positive on FDG-PET in three of four patients, and on CHOL-PET in two of four. SUV values were significantly higher for FDG (FDG 6.6{+-}3.5, CHOL 5.5{+-}2.5, P=0.04). CHOL-PET is able to visualise oesophageal carcinoma and its metastases, but appears to be inferior to FDG-PET. Presumably this is the result of lower tumoural uptake and considerable non-specific uptake of CHOL in liver, stomach wall, pancreas and small intestine. Further studies are needed to confirm these data. (orig.)

  18. Regional myocardial oxygen consumption estimated by carbon-11 acetate and positron emission tomography before and after repetitive ischemia

    DEFF Research Database (Denmark)

    Kofoed, K F; Hansen, P R; Holm, S

    2000-01-01

    alternating with 5 minutes of reperfusion. Before and after repetitive coronary occlusions, oxygen 15 water/oxygen 15 carbon monoxide (blood flow), and 11C-acetate (oxygen consumption) PET imaging were performed. Left ventricular regional systolic wall thickening was measured with sonomicrometry. Forty......BACKGROUND: Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short......-five minutes after the ischemic episodes, systolic ventricular wall thickening was decreased by 90%, whereas myocardial blood flow was reduced by 21% compared with baseline values (P consumption was unaltered compared with the baseline level...

  19. Non-detection of HC11N towards TMC-1: constraining the chemistry of large carbon-chain molecules

    Science.gov (United States)

    Loomis, Ryan A.; Shingledecker, Christopher N.; Langston, Glen; McGuire, Brett A.; Dollhopf, Niklaus M.; Burkhardt, Andrew M.; Corby, Joanna; Booth, Shawn T.; Carroll, P. Brandon; Turner, Barry; Remijan, Anthony J.

    2016-12-01

    Bell et al. reported the first detection of the cyanopolyyne HC11N towards the cold dark cloud TMC-1; no subsequent detections have been reported towards any source. Additional observations of cyanopolyynes and other carbon-chain molecules towards TMC-1 have shown a log-linear trend between molecule size and column density, and in an effort to further explore the underlying chemical processes driving this trend, we have analysed Green Bank Telescope observations of HC9N and HC11N towards TMC-1. Although we find an HC9N column density consistent with previous values, HC11N is not detected and we derive an upper limit column density significantly below that reported in Bell et al. Using a state-of-the-art chemical model, we have investigated possible explanations of non-linearity in the column density trend. Despite updating the chemical model to better account for ion-dipole interactions, we are not able to explain the non-detection of HC11N, and we interpret this as evidence of previously unknown carbon-chain chemistry. We propose that cyclization reactions may be responsible for the depleted HC11N abundance, and that products of these cyclization reactions should be investigated as candidate interstellar molecules.

  20. LBA-ECO ND-11 Litter Decomposition, Carbon, and Nitrogen Dynamics in Agroforestry

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the results of an experiment to determine litter decomposition and dynamics of carbon and nitrogen release from plant litter of differing...

  1. LBA-ECO ND-11 Litter Decomposition, Carbon, and Nitrogen Dynamics in Agroforestry

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains the results of an experiment to determine litter decomposition and dynamics of carbon and nitrogen release from plant litter of...

  2. UNUSUAL ENERGY-DEPENDENCE OF THE TOTAL NUCLEAR-REACTION CROSS-SECTION FOR A SECONDARY ISOMERIC NUCLEAR BEAM (F-18(M), J(PI)=5(+), E(X)=1.1 MEV)

    NARCIS (Netherlands)

    ROBERTS, DA; BECCHETTI, FD; BROWN, JA; JANECKE, J; PHAM, K; ODONNELL, TW; WARNER, RE; RONNINGEN, RM; WILSCHUT, HW

    1995-01-01

    A primary O-17 beam has been used to produce a 22.3 MeV/nucleon F-18(m) isomeric secondary beam via a single nucleon transfer reaction on a carbon target. The total nuclear reaction cross sections for F-18(m) and F-18(g.s.) in silicon were measured in a stack of seven silicon solid-state detectors.

  3. Carbon ion beam is more effective to induce cell death in sphere-type A172 human glioblastoma cells compared with X-rays.

    Science.gov (United States)

    Takahashi, Momoko; Hirakawa, Hirokazu; Yajima, Hirohiko; Izumi-Nakajima, Nakako; Okayasu, Ryuichi; Fujimori, Akira

    2014-12-01

    To obtain human glioblastoma cells A172 expressing stem cell-related protein and comparison of radiosensitivity in these cells with X-rays and carbon beam. Human monolayer-type A172 glioblastoma cells were maintained in normal medium with 10% bovine serum. In order to obtain sphere-type A172 cells the medium was replaced with serum-free medium supplemented with growth factors. Both types of A172 cells were irradiated with either X-rays or carbon ion beams and their radiosensitivity was evaluated. Serum-free medium induced expression of stem cell-related proteins in A172 cells along with the neurosphere-like appearance. These sphere-type cells were found resistant to both X-rays and carbon ion beams. Phosphorylation of histone H2A family member X persisted for a longer period in the cells exposed to carbon ion beams than in those exposed to X-rays and it disappeared quicker in the sphere type than in the monolayer type. Relative radioresistance of the sphere type cells was smaller for carbon ion beams than for X-rays. We demonstrated that glioblastoma A172 cells with induced stem cell-related proteins turned resistant to irradiation. Accelerated heavy ion particles may have advantage over X-rays in overcoming the tumor resistance due to cell stemness.

  4. ECG-based 4D-dose reconstruction of cardiac arrhythmia ablation with carbon ion beams: application in a porcine model

    Science.gov (United States)

    Richter, Daniel; Immo Lehmann, H.; Eichhorn, Anna; Constantinescu, Anna M.; Kaderka, Robert; Prall, Matthias; Lugenbiel, Patrick; Takami, Mitsuru; Thomas, Dierk; Bert, Christoph; Durante, Marco; Packer, Douglas L.; Graeff, Christian

    2017-09-01

    Noninvasive ablation of cardiac arrhythmia by scanned particle radiotherapy is highly promising, but especially challenging due to cardiac and respiratory motion. Irradiations for catheter-free ablation in intact pigs were carried out at the GSI Helmholtz Center in Darmstadt using scanned carbon ions. Here, we present real-time electrocardiogram (ECG) data to estimate time-resolved (4D) delivered dose. For 11 animals, surface ECGs and temporal structure of beam delivery were acquired during irradiation. R waves were automatically detected from surface ECGs. Pre-treatment ECG-triggered 4D-CT phases were synchronized to the R-R interval. 4D-dose calculation was performed using GSI’s in-house 4D treatment planning system. Resulting dose distributions were assessed with respect to coverage (D95 and V95), heterogeneity (HI  =  D5-D95) and normal tissue exposure. Final results shown here were performed offline, but first calculations were started shortly after irradiation The D95 for TV and PTV was above 95% for 10 and 8 out of 11 animals, respectively. HI was reduced for PTV versus TV volumes, especially for some of the animals targeted at the atrioventricular junction, indicating residual interplay effects due to cardiac motion. Risk structure exposure was comparable to static and 4D treatment planning simulations. ECG-based 4D-dose reconstruction is technically feasible in a patient treatment-like setting. Further development of the presented approach, such as real-time dose calculation, may contribute to safe, successful treatments using scanned ion beams for cardiac arrhythmia ablation.

  5. Evaluation of the mechanical properties of carbon fiber after electron beam irradiation

    International Nuclear Information System (INIS)

    Giovedi, Claudia; Diva Brocardo Machado, Luci; Augusto, Marcos; Segura Pino, Eddy; Radino, Patricia

    2005-01-01

    Carbon fibers are used as reinforcement material in epoxy matrix in advanced composites. An important aspect of the mechanical properties of composites is associated to the adhesion between the surface of the carbon fiber and the epoxy matrix. This paper aimed to the evaluation of the effects of EB irradiation on the tensile properties of two different carbon fibers prepared as resin-impregnated specimens. The fibers were EB irradiated before the preparation of the resin-impregnated specimens for mechanical tests. Observations of the specimens after breakage have shown that EB irradiation promoted significant changes in the failure mode. Furthermore, the tensile strength data obtained for resin-impregnated specimens prepared with carbons fibers previously irradiated presented a slight tendency to be higher than those obtained from non-irradiated carbon fibers

  6. Rapid synthesis and purification of carbon-11 labelled DOPA: a potential agent for brain studies

    International Nuclear Information System (INIS)

    Reiffers, S.; Beerling-van der Molen, H.D.; Vaalburg, W.; Hoeve, W. ten; Paans, A.M.J.; Korf, J.; Woldring, M.G.; Wynberg, H.

    1977-01-01

    A rapid method for preparation and purification of β-(3,4-dihydroxyphenyl)-D,L-α-alanine-1- 11 C( 11 C-DOPA), using 11 CO 2 as the radioactive precursor is described. Carboxylation of an α-lithioisocyanide, containing protected hydroxylic groups, was followed by a three-step hydrolysis of the intermediate αioscyano carboxylic acid. Preliminary experiments in rats indicate that the compound is preferentially decarboxylated in brain areas rich in dopamine containing neurons. (author)

  7. Chemical investigations of isotope separation on line target units for carbon and nitrogen beams

    CERN Document Server

    Franberg, H; Gäggeler, H W; Köster, U

    2006-01-01

    Radioactive ion beams (RIBs) are of significant interest in a number of applications. Isotope separation on line (ISOL) facilities provide RIB with high beam intensities and good beam quality. An atom that is produced within the ISOL target will first diffuse out from the target material. During the effusion towards the transfer line and into the ion source the many contacts with the surrounding surfaces may cause unacceptable delays in the transport and, hence, losses of the shorter-lived isotopes. We performed systematic chemical investigations of adsorption in a temperature and concentration regime relevant for ISOL targets and ion source units, with regard to CO/sub x/ and NOmaterials are potential construction materials for the above-mentioned areas. Off-line and on-line tests have been performed using a gas thermochromatography setup with radioactive tracers. The experiments were performed at the production of tracers for atmospheric chemistry (PROTRAC) facility at the Paul Schener Institute in Villigen...

  8. A scintillating gas detector for 2D dose measurements in clinical carbon beams.

    Science.gov (United States)

    Seravalli, E; de Boer, M; Geurink, F; Huizenga, J; Kreuger, R; Schippers, J M; van Eijk, C W E; Voss, B

    2008-09-07

    A two-dimensional position sensitive dosimetry system based on a scintillating gas detector has been developed for pre-treatment verification of dose distributions in hadron therapy. The dosimetry system consists of a chamber filled with an Ar/CF4 scintillating gas mixture, inside which two cascaded gas electron multipliers (GEMs) are mounted. A GEM is a thin kapton foil with copper cladding structured with a regular pattern of sub-mm holes. The primary electrons, created in the detector's sensitive volume by the incoming beam, drift in an electric field towards the GEMs and undergo gas multiplication in the GEM holes. During this process, photons are emitted by the excited Ar/CF4 gas molecules and detected by a mirror-lens-CCD camera system. Since the amount of emitted light is proportional to the dose deposited in the sensitive volume of the detector by the incoming beam, the intensity distribution of the measured light spot is proportional to the 2D hadron dose distribution. For a measurement of a 3D dose distribution, the scintillating gas detector is mounted at the beam exit side of a water-bellows phantom, whose thickness can be varied in steps. In this work, the energy dependence of the output signal of the scintillating gas detector has been verified in a 250 MeV/u clinical 12C ion beam by means of a depth-dose curve measurement. The underestimation of the measured signal at the Bragg peak depth is only 9% with respect to an air-filled ionization chamber. This is much smaller than the underestimation found for a scintillating Gd2O2S:Tb ('Lanex') screen under the same measurement conditions (43%). Consequently, the scintillating gas detector is a promising device for verifying dose distributions in high LET beams, for example to check hadron therapy treatment plans which comprise beams with different energies.

  9. Distribution of carbon-11 labeled methamphetamine and the effect of its chronic administration in mice

    International Nuclear Information System (INIS)

    Mizugaki, Michinao; Hishinuma, Takanori; Nakamura, Hitoshi

    1993-01-01

    [ 11 C]Methamphetamine, a psychotropic agent, was synthesized by N-methylation of amphetamine with [ 11 C]CH 3 I in hopes that it could be applied in the near future to assist positron emission tomography (PET) in the imaging of its distribution in the human brain. The regional distribution of [ 11 C]methamphetamine was investigated in the mice brain at various intervals after an intravenous (i.v.) injection. Radioactivity was higher in the hypothalamus, cortex, striatum and hippocampus. Furthermore, in chronically administered mice, the uptake of [ 11 C]methamphetamine was higher in the striatum than those in other regions. The regional differences in the distribution of methamphetamine in the mice brain may enable the imaging of its distribution by PET using [ 11 C]methamphetamine. (Author)

  10. Distribution of carbon-11 labeled methamphetamine and the effect of its chronic administration in mice

    International Nuclear Information System (INIS)

    Mizugaki, Michinao; Hishinuma, Takanori; Nakamura, Hitoshi

    1993-01-01

    [ 11 C]methamphetamine, a psychotropic agent, was synthesized by N-methylation of amphetamine with [ 11 C]CH 3 I in hopes that it could be applied in the near future to assist positron emission tomography (PET) in the imaging of its distribution in the human brain. The regional distribution of [ 11 C]methamphetamine was investigated in the mouse brain at various intervals after an intravenous (i.v.) injection. Radioactivity was higher in the hypothalamus, cortex, striatum and hippocampus. Furthermore, in chronically administered mice, the uptake of [ 11 C]methamphetamine was higher in the striatum than those in other regions. The regional differences in the distribution of methamphetamine in the mice brain may enable the imaging of its distribution by PET using [ 11 C]methamphetamine. (author)

  11. Distribution of carbon-11 labeled methamphetamine and the effect of its chronic administration in mice

    Energy Technology Data Exchange (ETDEWEB)

    Mizugaki, Michinao; Hishinuma, Takanori; Nakamura, Hitoshi (Tohoku University Hospital, Sendai (Japan). Dept. of Pharmaceutical Sciences) (and others)

    1993-05-01

    [[sup 11]C]methamphetamine, a psychotropic agent, was synthesized by N-methylation of amphetamine with [[sup 11]C]CH[sub 3]I in hopes that it could be applied in the near future to assist positron emission tomography (PET) in the imaging of its distribution in the human brain. The regional distribution of [[sup 11]C]methamphetamine was investigated in the mouse brain at various intervals after an intravenous (i.v.) injection. Radioactivity was higher in the hypothalamus, cortex, striatum and hippocampus. Furthermore, in chronically administered mice, the uptake of [[sup 11]C]methamphetamine was higher in the striatum than those in other regions. The regional differences in the distribution of methamphetamine in the mice brain may enable the imaging of its distribution by PET using [[sup 11]C]methamphetamine. (author).

  12. Development of rapid multistep carbon-11 radiosynthesis of the myeloperoxidase inhibitor AZD3241 to assess brain exposure by PET microdosing

    International Nuclear Information System (INIS)

    Johnström, Peter; Bergman, Linda; Varnäs, Katarina; Malmquist, Jonas; Halldin, Christer; Farde, Lars

    2015-01-01

    Introduction: The myeloperoxidase inhibitor AZD3241 has been selected as a candidate drug currently being developed to delay progression in patients with neurodegenerative brain disorders. Part of the decision tree for translation of AZD3241 into clinical studies included the need for assessment of brain exposure in non-human primates by PET microdosing. For that purpose a rapid multistep method for 11 C-labeling of AZD3241 was developed. Methods: AZD3241 was labeled in the thio-carbonyl position starting from [ 11 C]potassium cyanide in a 4-step procedure using microwave assisted heating. In the first step [ 11 C]potassium cyanide was converted to [ 11 C]potassium thiocyanate followed by reaction with benzoyl chloride to yield benzoyl [ 11 C]isothiocyanate. The benzoyl [ 11 C]isothiocyanate was subsequently reacted with the precursor ethyl 3-(2-isopropoxyethylamino)-1H-pyrrole-2-carboxylate and the formed intermediate underwent a base catalyzed cyclization to obtain [ 11 C]AZD3241 in the final step. To assess [ 11 C]AZD3241 brain exposure PET measurements were performed in three cynomolgus monkeys. Results: [ 11 C]AZD3241 was produced in good and reproducible radiochemical yield 710 ± 294 MBq (mean ± SD, n = 7). Total time of synthesis was 60 min from end of bombardment. The specific radioactivity was 9 ± 4 GBq/μmol and the radiochemical purity was > 98%. Following iv administration of [ 11 C]AZD3241 there was a rapid presence of radioactivity in brain in each of the three monkeys. The distribution of [ 11 C]AZD3241 to brain was fast and a C max of 1.9 to 2.6% of the injected radioactivity was observed within 1.5 min. [ 11 C]AZD3241 was homogeneously distributed in brain. Conclusion: The MPO inhibitor AZD3241 was successfully labeled with carbon-11 in a challenging 4-step procedure in good radiochemical yield allowing PET microdosing studies in cynomolgus monkey. [ 11 C]AZD3241 rapidly entered brain and confirmed adequate brain exposure to support translation

  13. Assessing and ameliorating the influence of the electron beam on carbon nanotube oxidation in environmental transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Ai Leen, E-mail: alkoh@stanford.edu [Stanford Nano Shared Facilities, Stanford University, Stanford, CA 94305 (United States); Sinclair, Robert [Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305 (United States)

    2017-05-15

    In this work, we examine how the imaging electron beam can induce damage in carbon nanotubes (CNTs) at varying oxygen gas pressures and electron dose rates using environmental transmission electron microscopy (ETEM). Our studies show that there is a threshold cumulative electron dose which brings about damage in CNTs in oxygen – through removal of their graphitic walls – which is dependent on O{sub 2} pressure, with a 4–5 fold decrease in total electron dose per decade increase at a lower pressure range (10{sup −6} to 10{sup −5} mbar) and approximately 1.3 –fold decrease per decade increase at a higher pressure range (10{sup −3} to 10{sup 0} mbar). However, at a given pressure, damage in CNTs was found to occur even at the lowest dose rate utilized, suggesting the absence of a lower limit for the latter parameter. This study provides guidelines on the cumulative dose required to damage nanotubes in the 10{sup −7} mbar to 10{sup 0} mbar pressure regimes, and discusses the role of electron dose rate and total electron dose on beam-induced CNT degradation experiments. - Highlights: • The electron beam ionizes gas molecules in ETEM and affects experimental outcomes. • Beam-induced damage in CNTs occurs at varying O{sub 2} pressures and electron dose rates. • There is a threshold cumulative dose to damage CNTs which depends on O{sub 2} pressure. • At a given pressure, CNT damage occurs even at the electron dose rate utilized.

  14. Application of carbon-11 labelled nicotine in the measurement of human cerebral blood flow and other physiological parameters

    International Nuclear Information System (INIS)

    Yokoi, Fuji; Hayashi, Tokishi; Iio, Masaaki; Hara, Toshihiko

    1993-01-01

    Using positron emission tomography (PET), we measured the regional cerebral blood flow (rCBF) in five normal human subjects after intravenous injection of carbon-11 labelled (R)nicotine. The rCBF of the same subjects was measured by PET using the C 15 O 2 inhalation steady-state method. The distribution of 11 C activity in the brain after injection of 11 C-(R)nicotine was almost equivalent to the CBF image obtaines with C 15 O 2 inhalation steady-state method. The kinetics of 11 C-(R)nicotine in the brain was analysed using a two-compartment model consisting of vascular and brain tissue compartments. The rCBF values obtained with 11 C-(R)nicotine were higher than with C 15 O 2 gas. It is possible that the relatively long fixed distribution of 11 C-(R)nicotine with a short uptake period allows stimulation studies by measurement of CBF to be performed with better photon flux and a longer imaging time than are possible with H 2 15 O. (orig.)

  15. Carbon Fiber Reinforced Polymer Grids for Shear and End Zone Reinforcement in Bridge Beams

    Science.gov (United States)

    2018-01-01

    Corrosion of reinforcing steel reduces life spans of bridges throughout the United States; therefore, using non-corroding carbon fiber reinforced polymer (CFRP) reinforcement is seen as a way to increase service life. The use of CFRP as the flexural ...

  16. Dynamics of carbon dioxide transport in a multiple sink network (GHGT-11)

    NARCIS (Netherlands)

    Veltin, J.; Belfroid, S.P.C.

    2013-01-01

    As Carbon Capture and Storage slowly gets accepted and integrated as a mean for cleaner utilization of fossil fuels, the integration of capture, transport and storage becomes a key component to properly design a CO2 network. While the boundary conditions set by the capture and storage units have

  17. Fabrication of carbon quantum dots with nano-defined position and pattern in one step via sugar-electron-beam writing.

    Science.gov (United States)

    Weng, Yuyan; Li, Zhiyun; Peng, Lun; Zhang, Weidong; Chen, Gaojian

    2017-12-14

    Quantum dots (QDs) are promising materials in nanophotonics, biological imaging, and even quantum computing. Precise positioning and patterning of QDs is a prerequisite for realizing their actual applications. Contrary to the traditional two discrete steps of fabricating and positioning QDs, herein, a novel sugar-electron-beam writing (SEW) method is reported for producing QDs via electron-beam lithography (EBL) that uses a carefully chosen synthetic resist, poly(2-(methacrylamido)glucopyranose) (PMAG). Carbon QDs (CQDs) could be fabricated in situ through electron beam exposure, and the nanoscale position and luminescence intensity of the produced CQDs could be precisely controlled without the assistance of any other fluorescent matter. We have demonstrated that upon combining an electron beam with a glycopolymer, in situ production of CQDs occurs at the electron beam spot center with nanoscale precision at any place and with any patterns, an advancement that we believe will stimulate innovations in future applications.

  18. Carbon-11 and radioiodinated derivatives of lysergic acid diethylamide: Ligands for the study of serotonin S2 receptors in vivo

    International Nuclear Information System (INIS)

    Lever, J.R.; Hartig, P.R.; Wong, D.F.

    1985-01-01

    2-[ 125 1]-LSD binds selectively and with high affinity to serotonin S2 receptors in vitro. In the present study, the authors prepared 2-[ 123 1]-LSD as well as a carbon-11 labeled analog. They also characterized the in vivo binding of these tracers to receptor sites in mouse brain to assess their potential for tomographic imaging of S2 receptors in man. The temporal distribution of 2-[ 125 1]-LSD paralleled the density of S2 receptors. Regional selectivity was maximal after 15 minutes when tissue to cerebellum ratios were: frontal cortex (2.6), olfactory tubercles (2.4), striatum (2.3), and cortex (2.0). Preinjection of ketanserin, a potent S2 antagonist, inhibited binding. 2-[ 123 1]-LSD, prepared in 20% yield from LSD and electrophilic I-123, gave similar results in vivo and may be useful for SPECT studies. The authors then synthesized N1-([ 11 C]-Me)-2-Br-LSD ( 11 C-MBL) from [ 11 C]-methyl iodide and 2-Br-LSD for PET imaging trials. 11 C-MBL was isolated by HPLC in high chemical and radiochemical purity within 30 minutes from E.O.B. The average radiochemical yield was 20% and the specific activity was determined by U.V. spectroscopy to be up to 1300Ci/mMol (E.O.S.). 11C-MBL showed greater regional selectivity in vivo in mouse brain than 2-[ 125 1]-LSD. After 30 minutes, peak tissue to cerebellum ratios were: frontal cortex (5.4), olfactory tubercles (4.2), striatum (3.0), and cortex (2.8). Preinjection of ketanserin markedly inhibited 11 C-MBL binding. 11 C-MBL is a promising candidate for PET studies of S2 receptors

  19. Gases and carbon in metals - thermodynamics, kinetics, and properties. Pt. 11

    International Nuclear Information System (INIS)

    Jehn, H.; Speck, H.; Fromm, E.; Hoerz, G.

    1980-01-01

    This issue is part of a series of data on Gases and Carbon in Metals which supplements the data compilation in the book Gase and Kohlenstoff in Metallen (Gases and Carbon in Metals), edited by E.Fromm and E.Gebhardt, Springer-Verlag, Berlin 1976. The present survey includes results from papers published after the copy deadline and recommends critically selected data. Furthermore it comprises a bibliography of relevant literature. For each element the information is given in two parts. In a first section data are listed and in a second section the relevant literature is compiled. For each element, firstly data on binary systems are presented, starting with hydrogen and followed by carbon, nitrogen, oxygen, and rare gases. Within one metal-metalloid system the data are listed under topics such as solubility, solubility limit, dissociation pressure of compounds, vapour pressure of volatile oxides, thermodynamic data, diffusion, transport parameters (effective valence, heat of transport), permeation of gases through metals, gas absorption and gas desorption kinetics, compound formation kinetics, precipitation kinetics, and property changes. (orig./GE)

  20. Chemical Investigations of ISOL target units for carbon and nitrogen beams

    CERN Document Server

    Franberg, H; Gäggeler, H W; Köster, U

    2006-01-01

    Radioactive Ion Beams (RIB) are of significant interest in a number of applications. ISOL (Isotope Separation On Line) facilities provide RIB with high beam intensities and good beam quality. An atom that is produced within the ISOL target will first diffuse out from the target material. During the effusion towards the transfer line and into the ion source the many contacts with the surrounding surfaces may cause unacceptable delays in the transport and, hence, losses of the shorter-lived isotopes. We performed systematic chemical investigations of adsorption in a temperature and concentration regime relevant for ISOL targets and ion source units, with regard to COx and NOx on Al2O3 and SiO2. These materials are potential construction materials for the above mentioned areas. Off-line and on-line tests have been performed using a gas thermo-chromatography set-up with radioactive tracers. The experiments were performed at the PROTRAC facility at Paul Scherrer Institute in Villigen, Switzerland.

  1. A Study of Charged Current Single Charged Pion Productions on Carbon in a Few-GeV Neutrino Beam

    Energy Technology Data Exchange (ETDEWEB)

    Hiraide, Katsuki [Kyoto Univ. (Japan)

    2009-01-01

    Understanding single charged pion production via neutrino-nucleus charged current interaction in the neutrino energy region of a few GeV is essential for future neutrino oscillation experiments since this process is a dominant background for vμ → vx oscillation measurements. There are two contributions to this process: single pion production via baryonic resonance (vμN → μ-+) and coherent pion production interacting with the entire nucleus (vμA → μ-+), where N is nucleon in the nucleus and A is the nucleus. The purpose of the study presented in this thesis is a precise measurement of charged current single charged pion productions, resonant and coherent pion productions, with a good final state separation in the neutrino energy region of a few GeV. In this thesis, we focus on the study of charged current coherent pion production from muon neutrinos scattering on carbon, vμ 12C → μ-12+, in the SciBooNE experiment. This is motivated by the fact that without measuring this component first, the precise determination of resonant pion production cross section can not be achieved since the contribution of coherent pion production in the region of small muon scattering angle is not small. Furthermore, the coherent process is particularly interesting because it is deeply rooted in fundamental physics via Adler's partially conserved axial-vector current theorem. We took data from June 2007 until August 2008, in both the neutrino and antineutrino beam. In total, 2.52 x 1020 protons on target were collected. We have performed a search for charged current coherent pion production by using SciBooNE's full neutrino data set, corresponding to 0.99 x 1020 protons on target. No evidence for coherent pion production is observed. We set 90% confidence level upper limits on the cross section ratio

  2. Radiosensitivity of cancer cells against carbon-ion beams in an aspect of the p53 gene status

    International Nuclear Information System (INIS)

    Takahashi, Akihisa; Ohnishi, Takeo; Matsumoto, Hideki

    2004-01-01

    We can easily understand that radiation sensitivities of cancer cells are dependent on the status of cancer-related genes. It is important to clarify which genes affect radiation sensitivity and reflect the effectiveness of radiation therapy for cancer cells. We have studied about the function of a tumor suppressor gene of p53, because p53 controls apoptosis, cell cycle and DNA repair from an aspect of important roles in cell fate. By analysis of function of p53 gene, therefore, we aim to predict the therapeutic effectiveness and to select the modalities of cancer therapies such as radiotherapy, chemotherapy and hyperthermia. As a final goal, we want to accept the most effective therapy, namely tailor-made cancer therapy, for each patient. Here, we introduce that carbon-beam therapy induced the expression of p53-independent apoptosis-related genes and NO radicals in mutated p53 cancer cells. (author)

  3. Structure and properties of steel case-hardened by non-vacuum electron-beam cladding of carbon fibers

    Science.gov (United States)

    Losinskaya, A. A.; Lozhkina, E. A.; Bardin, A. I.

    2017-12-01

    At the present time, the actual problem of materials science is the increase in the steels performance characteristics. In the paper some mechanical properties of the case-hardened materials received by non-vacuum electron-beam cladding of carbon fibers are determined. The depth of the hardened layers varies from 1.5 to 3 mm. The impact strength of the samples exceeds 50 J/cm2. The wear resistance of the coatings obtained exceeds the properties of steel 20 after cementation and quenching with low tempering. The results of a study of the microhardness of the resulting layers and the microstructure are also given. The hardness of the surface layers exceeds 5700 MPa.

  4. Imperfection Sensitivity of Nonlinear Vibration of Curved Single-Walled Carbon Nanotubes Based on Nonlocal Timoshenko Beam Theory

    Directory of Open Access Journals (Sweden)

    Iman Eshraghi

    2016-09-01

    Full Text Available Imperfection sensitivity of large amplitude vibration of curved single-walled carbon nanotubes (SWCNTs is considered in this study. The SWCNT is modeled as a Timoshenko nano-beam and its curved shape is included as an initial geometric imperfection term in the displacement field. Geometric nonlinearities of von Kármán type and nonlocal elasticity theory of Eringen are employed to derive governing equations of motion. Spatial discretization of governing equations and associated boundary conditions is performed using differential quadrature (DQ method and the corresponding nonlinear eigenvalue problem is iteratively solved. Effects of amplitude and location of the geometric imperfection, and the nonlocal small-scale parameter on the nonlinear frequency for various boundary conditions are investigated. The results show that the geometric imperfection and non-locality play a significant role in the nonlinear vibration characteristics of curved SWCNTs.

  5. Preparation of carbon-11 labelled erythromycin A lactobionate for the study of the antibiotic in vivo

    International Nuclear Information System (INIS)

    Palmer, A.J.; Pike, V.W.; Horlock, P.L.; Perun, L.A.; Freiberg, L.A.; Dunnigan, D.A.; Liss, R.H.

    1982-01-01

    Erythromycin A is produced naturally by Streptomyces erythreus and is an important macrolide antibiotic. This paper describes the chemical synthesis of Erythromycin A by the reductive methylation of N-dimethylerythromycin A, and its labelling with 11 C formaldehyde. (U.K.)

  6. Asymmetric Synthesis of Carbon-11 Labelled alpha-Amino Acids for PET

    NARCIS (Netherlands)

    Popkov, Alexander; Elsinga, Philip H.

    2013-01-01

    For PET applications in oncological and neurological diagnostics, amino acids have been studied both clinically and pre-clinically during the last 35 years. Nowadays two applications of labelled amino acids for visualisation of tumours attract the main attention: [C-11] or [F-18]amino acids as

  7. The use of multi-gap resistive plate chambers for in-beam PET in proton and carbon ion therapy

    CERN Document Server

    Watts, David; Sauli, Fabio; Amaldi, Ugo

    2013-01-01

    On-line verification of the delivered dose during proton and carbon ion radiotherapy is currently a very desirable goal for quality assurance of hadron therapy treatment plans. In-beam positron emission tomography (ibPET), which can provide an image of the β+ activity induced in the patient during irradiation, which in turn is correlated to the range of the ion beam, is one of the modalities for achieving this goal. Application to hadron therapy requires that the scanner geometry be modified from that which is used in nuclear medicine. In particular, PET detectors that allow a sub-nanosecond time-of-flight (TOF) registration of the collinear photons have been proposed. Inclusion of the TOF information in PET data leads to more effective PET sensitivity. Considering the challenges inherent in the ibPET technique, namely limited β+ activity and the effect of biological washout due to blood flow, TOF-PET technologies are very attractive. In this context, the TERA Foundation is investigating the use of resistiv...

  8. Microscopical investigation of cellular effects of 135 MeV/amu carbon along the path of the beam

    International Nuclear Information System (INIS)

    Furuse, Masako; Soga, Fuminori; Matsumoto, Shinji

    1993-01-01

    The difference in biological effects are normally described by the concept of RBE. However, the RBE values depend on the LET along a trajectory and also on complicated parameters such as the distribution of the energy deposition due to the difference in the spread of secondary electrons perpendicular to a beam axis. The authors are interested in the use of a biological dosimeter of microorganisms which can directly compare biological effects such as survival level. The survival rate of yeast cells was tested for this purpose with a carbon beam at 135 MeV/amu from the RIKEN ring cyclotron. The haploid cells of a wild type and a radiation sensitive mutant were used. Yeast is a simple eukaryote, and it has been used as the test organism especially for the studies on the relation between DNA double-strand breaks and cell killing. The materials used, the experimental method and the results are reported. The survival data of the wild type and the radiation sensitive mutant at stationary and log phases were obtained, and the values were used for the RBE estimation. The resistance seemed due to the action of enzymatic repair mechanism. (K.I.)

  9. The effects of beam energy and substrate temperature on the tribological properties of hard-carbon films on aluminum

    International Nuclear Information System (INIS)

    Wei, R.; Wilbur, P.J.; Erdemir, A.; Kustas, F.M.

    1992-01-01

    Hard-carbon films were applied on flat 6061-T6 aluminum substrates using a broad-beam ion source operating on methane and producing carbonaceous ions with energies that varied from 250 to 1050 eV. Films were evaluated using a reciprocating alumina ball-on-flat sliding wear tester operating in an ambient air test environment. The films facilitated substantial reductions in friction coefficients to 0.08-0.2 from 0.4-0.7 for uncoated aluminum. At a sufficiently high normal load, the films failed and friction coefficients increased to the higher range. The best film caused this critical normal load to increase from less than 0.1 N for untreated aluminum to greater than 30 N. A near-optimal beam ion energy (450 eV) was identified for good quality films. At lower energies (e.g. 250 eV) films were discontinuous, while at higher energies (e.g. 1050 eV) high sputter rates limited film growth. When an aluminum flat was held at low temperature during processing, the films were smooth and adhered well, but they became rougher and adhered poorly as the temperature was increased above approximately 300degC. (orig.)

  10. Free vibration of a single-walled carbon nanotube containing a fluid flow using the Timoshenko beam model

    International Nuclear Information System (INIS)

    Chang, W.-J.; Lee, H.-L.

    2009-01-01

    The flexural vibration of the fluid-conveying single-walled carbon nanotube (SWCNT) is derived by the Timoshenko beam model, including rotary inertia and transverse shear deformation. The effects of the flow velocity and the aspect ratio of length to diameter on the vibration frequency and mode shape of the SWCNT are analyzed. Results show that the effects of rotary inertia and transverse shear deformation result in a reduction of the vibration frequencies, especially for higher modes of vibration and short nanotubes. The frequency is also compared with the previous study based on Euler beam model. In addition, if the ratio of length to diameter increased to 60, the influence of the shear deformation and rotary inertia on the mode shape and the resonant frequencies can be neglected. However, the influence is very obvious when the ratio decreased to 20. As the flow velocity of the fluid increases in the vicinity of 2π, the SWCNT reveals the divergence instability. It regains stability when the flow velocity reaches about 9. As the velocity increases further, the SWCNT undergoes a coupled-mode flutter and results in a larger amplitude

  11. One-nucleon transfer reactions induced by secondary beam of {sup 11}Be: study of the nuclear structure of the exotic nuclei {sup 11}Be and {sup 10}Li; Reactions de transfert d'un nucleon induites par un faisceau secondaire de {sup 11}Be: etude de la structure des noyaux exotiques {sup 11}Be et {sup 10}Li

    Energy Technology Data Exchange (ETDEWEB)

    Pita, S

    2000-09-01

    The structure of the neutron rich light nuclei {sup 11}Be and {sup 10}Li has been investigated by means of one nucleon transfer reactions. The experiments have been carried out at GANIL in inverse kinematics using {sup 11}Be secondary beams. The {sup 11}Be(p,d){sup 10}Be reaction bas been studied at 35.3 MeV/u. The {sup 10}Be ejectiles were analyzed by the spectrometer SPEG, and coincident deuterons were detected in the position sensitive silicon detector CHARISSA. Transfer cross sections to 0{sup +}{sub 1} and 2{sup +}{sub 1}, states in {sup 10}Be were measured up to {theta}{sub CM} = 16 deg. and compared to DWBA and CRC predictions. The effects of neutron-cure couplings on reaction form factors have been studied by solving coupled equations in the framework of a vibrational model. It is shown that the rate of core excitation {sup 10}Be{sub 2+} in the {sup 11}Be{sub gs} wave function is overestimated by a standard analysis with form factors given by the usual Separation Energy prescription. The former model predicts a rate of core excitation of 16% and leads to theoretical cross sections which are in good agreement with the experimental data. The aim of the {sup 11}Be(d,{sup 3}He){sup 10}Li experiment, realized at 37 MeV/u, was to measure the distribution of the 2s neutron strength in the unbound nucleus {sup 10}Li. The energy spectrum was deduced from the {sup 3}He energy and angle measured by the silicon strip detector array MUST. An asymmetric peak is clearly observed near the threshold, with a maximum at -S{sub n} = 130 keV. This constitutes a direct proof of the inversion of 2s and 1p{sub 1/2} shells in {sup 10}Li, which was until now a controversial question in spite of many experimental efforts. On the other band the analysis of the {sup 11}Be(d,t){sup 10}Be reaction studied in the same experiment confirms the results obtained in the {sup 11}Be(p,d){sup 10}Be reaction concerning the {sup 11}Be{sub gs} structure. This work shows the interest and feasibility

  12. Carbon-11 and fluorine-18 chemistry devoted to molecular probes for imaging the brain with positron emission tomography.

    Science.gov (United States)

    Dollé, Frédéric

    2013-01-01

    Exploration of the living human brain in real-time and in a noninvasive way was for centuries only a dream, made, however, possible today with the remarkable development during the four last decades of powerful molecular imaging techniques, and especially positron emission tomography (PET). Molecular PET imaging relies, from a chemical point of view, on the use and preparation of a positron-emitting radiolabelled probe or radiotracer, notably compounds incorporating one of two short-lived radionuclides fluorine-18 (T1/2 : 109.8 min) and carbon-11 (T1/2 : 20.38 min). The growing availability and interest for the radiohalogen fluorine-18 in radiopharmaceutical chemistry undoubtedly results from its convenient half-life and the successful use in clinical oncology of 2-[(18) F]fluoro-2-deoxy-d-glucose ([(18) F]FDG). The special interest of carbon-11 is not only that carbon is present in virtually all biomolecules and drugs allowing therefore for isotopic labelling of their chemical structures but also that a given molecule could be radiolabelled at different functions or sites, permitting to explore (or to take advantage of) in vivo metabolic pathways. PET chemistry includes production of these short-lived radioactive isotopes via nuclear transmutation reactions using a cyclotron, and is directed towards the development of rapid synthetic methods, at the trace level, for the introduction of these nuclides into a molecule, as well as the use of fast purification, analysis and formulation techniques. PET chemistry is the driving force in molecular PET imaging, and this special issue of the Journal of Labelled Compounds and Radiopharmaceuticals, which is strongly chemistry and radiochemistry-oriented, aims at illustrating, be it in part only, the state-of-the-art arsenal of reactions currently available and its potential for the research and development of specific molecular probes labelled with the positron emitters carbon-11 and fluorine-18, with optimal imaging

  13. Two-dimensional thermal simulations of aluminum and carbon ion strippers for experiments at SPIRAL2 using the highest beam intensities

    International Nuclear Information System (INIS)

    Tahir, N.A.; Kim, V.; Lamour, E.; Lomonosov, I.V.; Piriz, A.R.; Rozet, J.P.; Stöhlker, Th.; Sultanov, V.; Vernhet, D.

    2012-01-01

    In this paper we report on two-dimensional numerical simulations of heating of a rotating, wheel shaped target impacted by the full intensity of the ion beam that will be delivered by the SPIRAL2 facility at Caen, France. The purpose of this work is to study heating of solid targets that will be used to strip the fast ions of SPIRAL2 to the required high charge state for the FISIC (Fast Ion–Slow Ion Collision) experiments. Strippers of aluminum with different emissivities and of carbon are exposed to high beam current of different ion species as oxygen, neon and argon. These studies show that carbon, due to its much higher sublimation temperature and much higher emissivity, is more favorable compared to aluminum. For the highest beam intensities, an aluminum stripper does not survive. However, problem of the induced thermal stresses and long term material fatigue needs to be investigated before a final conclusion can be drawn.

  14. Carbon-11 tyrosine PET for visualization and protein synthesis rate assessment of laryngeal and hypopharyngeal carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Jurjan R. de; Laan, Bernard F.A.M. van der; Albers, Frans W.J. [Department of Otorhinolaryngology and Head and Neck Surgery, Groningen University Hospital, Hanzeplein 1, 9700 RB Groningen (Netherlands); Pruim, Jan; Que, Tjin H.; Willemsen, Antoon T.M.; Vaalburg, Willem [PET Center of Groningen University Hospital, Groningen (Netherlands); Burlage, Fred [Department of Radiotherapy, Groningen University Hospital, Groningen (Netherlands); Krikke, Allard [Department of Radiology, Groningen University Hospital, Groningen (Netherlands); Tiebosch, Anton T.M.G. [Department of Pathology, Groningen University Hospital, Groningen (Netherlands)

    2002-09-01

    Accurate assessment of tumour extent and lymph node involvement in squamous cell carcinomas of the head and neck region is essential for therapy planning. Unfortunately, conventional diagnostic examination and imaging techniques, which monitor tumours on the basis of anatomical parameters, have drawbacks in clinical practice. The aim of this study was to investigate the feasibility of L-[1-{sup 11}C]-tyrosine (TYR) positron emission tomography (PET) for visualisation of squamous cell carcinoma of the larynx and hypopharynx and quantification of tumour activity by assessment of protein synthesis rate (PSR). Dynamic TYR PET was performed on 31 patients with T1-T4 laryngeal or hypopharyngeal carcinoma before therapy. Plasma activity of TYR, {sup 11}CO{sub 2} and {sup 11}C-protein levels were measured, and PSRs were calculated for primary malignancies. All 31 laryngeal and hypopharyngeal tumours were visualised as a hotspot (sensitivity 100%). The median PSR of the tumours (2.06 nmol ml{sup -1} min{sup -1}; range 0.72-6.96) was significantly higher (P<0.001) than that of non-tumour (background) tissue (0.51 nmol ml{sup -1} min{sup -1}; range 0.22-0.89). L-[1-{sup 11}C]-Tyrosine PET appears to be a potential method for visualisation of primary laryngeal and hypopharyngeal tumours. In vivo quantification of tumour activity by assessment of PSR is possible and may have a future role in the therapy planning and therapy evaluation of laryngeal and hypopharyngeal tumours. (orig.)

  15. Carbon-11 labelled ketamine-synthesis, distribution in mice and PET studies in baboons

    International Nuclear Information System (INIS)

    Shiue, C.-Y.; Vallabhahosula, Shankar; Wolf, Alfred P.; Dewey, Stephen L.; Fowler, Joanna S.; Schlyer, David J.; Arnett, Carroll D.; Zhou Yiguo

    1997-01-01

    No-carrier-added (NCA)[ 11 C](±)-ketamine (2a) and its enantiomers (+)-2b and (-)-2c were synthesized by methylation of the corresponding norketamine (1a-c) with [ 11 C]H 3 I in an overall radiochemical yield of 20% (EOB) with specific activities of 0.35-0.45 Ci/μmole at EOB in a synthesis time of 40 min from EOB. Compound 2a was metabolized rapidly in mouse brain and labeled metabolites appeared in baboon plasma. PET studies of compounds 2a-c in a baboon showed that influx of compounds 2a-c into the brain was high for the first few min but radioactivity then declined rapidly. Although the retention of radioactivity in the baboon striatum was not significantly different for 2a-c 20 min post-injection, graphical analysis of time-activity data for each enantiomer and for the racemate in baboon striatum suggested that (+)-ketamine may interact with receptors slightly more effectively than its (-)-enantiomer or racemate. However, due to its rapid metabolism in the brain and a similar uptake in the striatum and cerebellum, [ 11 C]ketamine may not be an ideal tracer for studying NMDA receptor with PET

  16. Carbon-11 labelled ketamine-synthesis, distribution in mice and PET studies in baboons

    Energy Technology Data Exchange (ETDEWEB)

    Shiue, C.-Y.; Vallabhahosula, Shankar; Wolf, Alfred P.; Dewey, Stephen L.; Fowler, Joanna S.; Schlyer, David J.; Arnett, Carroll D.; Zhou Yiguo

    1997-02-01

    No-carrier-added (NCA)[{sup 11}C]({+-})-ketamine (2a) and its enantiomers (+)-2b and (-)-2c were synthesized by methylation of the corresponding norketamine (1a-c) with [{sup 11}C]H{sub 3}I in an overall radiochemical yield of 20% (EOB) with specific activities of 0.35-0.45 Ci/{mu}mole at EOB in a synthesis time of 40 min from EOB. Compound 2a was metabolized rapidly in mouse brain and labeled metabolites appeared in baboon plasma. PET studies of compounds 2a-c in a baboon showed that influx of compounds 2a-c into the brain was high for the first few min but radioactivity then declined rapidly. Although the retention of radioactivity in the baboon striatum was not significantly different for 2a-c 20 min post-injection, graphical analysis of time-activity data for each enantiomer and for the racemate in baboon striatum suggested that (+)-ketamine may interact with receptors slightly more effectively than its (-)-enantiomer or racemate. However, due to its rapid metabolism in the brain and a similar uptake in the striatum and cerebellum, [{sup 11}C]ketamine may not be an ideal tracer for studying NMDA receptor with PET.

  17. Effects of ion beam irradiation on the microstructures and strengths of different carbon fibers

    International Nuclear Information System (INIS)

    Oku, Tatsuo; Kurumada, Akira; Kawamata, Kiyohiro; Inagaki, Michio

    1998-01-01

    The high energy argon ion was irradiated to different carbon fibers with various microstructures. The cross-sectional structures and strengths properties have been evaluated before and after ion irradiation. As a result, the diameter of fibers decreased due to ion irradiation, except for the fiber with dual structure. The tensile strength also decreased due to ion irradiation, except for fibers which were not heat-treated. This suggests that it is necessary to consider not only the defects in the vertical cross-section but also changes in defect structures in the axial direction. The results of computer simulation indicated that argon ion with 175MeV/1μA produced homogeneous defects in the carbon fibers with the diameter of about 20 μm. (author)

  18. Sputtering of carbon using hydrogen ion beams with energies of 60–800 eV

    Energy Technology Data Exchange (ETDEWEB)

    Sidorov, Dmitry S., E-mail: dmitrisidoroff@rambler.ru [Nizhny Novgorod State University, 23 Gagarina Avenue, Nizhny Novgorod, Nizhny Novgorod Region 603950 (Russian Federation); Chkhalo, Nikolay I., E-mail: chkhalo@ipm.sci-nnov.ru [Institute for Physics of Microstructures RAS, Academicheskaya Str. 7, Afonino, Nizhny Novgorod Region, Kstovsky District, Kstovo Region 603087 (Russian Federation); Mikhailenko, Mikhail S.; Pestov, Alexey E.; Polkovnikov, Vladimir N. [Institute for Physics of Microstructures RAS, Academicheskaya Str. 7, Afonino, Nizhny Novgorod Region, Kstovsky District, Kstovo Region 603087 (Russian Federation)

    2016-11-15

    This article presents the result of a study on the sputtering of carbon films by low-energy hydrogen ions. In particular, the etching rate and surface roughness were measured. The range of energies where the sputtering switches from pure chemical to a combination of chemical and physical mechanisms was determined. It is shown that Sigmund’s theory for ion etching does not work well for fields of energy less than 150 eV and that it accurately describes the dependence of a sputtering coefficient on ion energy for energies greater than 300 eV. A strong smoothing effect for the surface of carbon film was also found. This result is interesting in itself and for its significance for the manufacture of super-smooth surfaces for X-ray applications.

  19. Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

    International Nuclear Information System (INIS)

    Wang Jufang; Lu Dong; Wu Xin; Sun Haining; Ma Shuang; Li Renmin; Li Wenjian

    2010-01-01

    To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV μm -1 ) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV μm -1 . The mutation cross section saturated when LET was higher than 58.2 keV μm -1 . Meanwhile, the highest RBE i for inactivation located at 120.0 keV μm -1 and the highest RBE m for mutation was at 58.2 keV μm -1 . The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

  20. Variable electron beam diameter achieved by a titanium oxide/carbon nanotube hetero-structure suitable for nanolithography

    International Nuclear Information System (INIS)

    Abdi, Yaser; Barati, Fatemeh

    2013-01-01

    We report the fabrication of a titanium oxide/carbon nanotube based field emission device suitable for nanolithography and fabrication of transistors. The growth of carbon nanotubes (CNTs) is performed on silicon substrates using a plasma-enhanced chemical vapor deposition method. The vertically grown CNTs are encapsulated by titanium oxide (TiO 2 ) using an atmospheric pressure chemical vapor deposition system. Field emission from the CNTs is realized by mechanical polishing of the prepared structure. Possible applications of such nanostructures as a lithography tool with variable electron beam diameter has been investigated. The obtained results show that a spot size of less than 30 nm can be obtained by applying the proper voltage on TiO 2 surrounding gate. Electrical measurements of the fabricated device confirm the capability of the structure for fabrication of field emission based field effect transistors. By a voltage applied between the gate and the cathode electrode, the emission current from CNTs shows a significant drop, indicating proper control of the gate on the emission current. (paper)

  1. Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

    Science.gov (United States)

    Wang, Jufang; Lu, Dong; Wu, Xin; Sun, Haining; Ma, Shuang; Li, Renmin; Li, Wenjian

    2010-09-01

    To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV μm -1) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV μm -1. The mutation cross section saturated when LET was higher than 58.2 keV μm -1. Meanwhile, the highest RBE i for inactivation located at 120.0 keV μm -1 and the highest RBE m for mutation was at 58.2 keV μm -1. The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

  2. Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jufang, E-mail: jufangwang@impcas.ac.c [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road No. 509, Lanzhou 730000 (China); Lu Dong; Wu Xin; Sun Haining; Ma Shuang; Li Renmin; Li Wenjian [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road No. 509, Lanzhou 730000 (China)

    2010-09-15

    To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV {mu}m{sup -1}) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV {mu}m{sup -1}. The mutation cross section saturated when LET was higher than 58.2 keV {mu}m{sup -1}. Meanwhile, the highest RBE{sub i} for inactivation located at 120.0 keV {mu}m{sup -1} and the highest RBE{sub m} for mutation was at 58.2 keV {mu}m{sup -1}. The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

  3. Flexure Behavior of Hybrid Continuous Deep Beam Strengthened by Carbon Fiber Reinforced Polymer

    Directory of Open Access Journals (Sweden)

    Hayder M.K.Al-Mutairee

    2017-08-01

    Full Text Available This study present an experimental investigation for overall flexure behavior of reinforced concrete continuous deep beams (RCCDB made of hybrid concrete, normal strength concrete (NSC and high strength concrete (HSC at different location and percentage. The experimental work includes testing of sixteen specimens of RCCDB under two points loads. The effects of HSC layer thickness and CFRP on strength of RCCDB had been studied. The experimental results showed that the strengthening of RCCDB by HSC layer from top is better than from bottom, where the increment in the ultimate flexural strength increased by (14,21,27% for top strengthening and (12,15,13% for bottom strengthening for (25,50,75% thickness of total depth of beam respectively. The optimal strengthening of RCCDB by HSC layer at top was of 25%. The results also proved that the strengthening of hybrid RCCDB by (10,15cm CFRP strip at the bottom for flexure gave increment in the ultimate strength by (32, 29% respectively, and the strengthening by CFRP strip for flexure at the bottom is better than at top for hybrid RCCDB. The shear strengthening of hybrid RCCDB increases the ultimate strength by 23.4% and 13.8% if the strengthening has O and U shape respectively

  4. Deposition and properties of Al-containing diamond-like carbon films by a hybrid ion beam sources

    International Nuclear Information System (INIS)

    Dai Wei; Wang Aiying

    2011-01-01

    Research highlights: → Weak carbide former, Al element, was incorporated into DLC films using a hybrid ion beams system comprising an anode-layer ion source and a magnetron sputtering unit. → The structure disorder of the films tended to decrease with Al atoms doping, which resulted in the distinct reduction of the film internal stress and hardness, but the internal stress dropped faster than the hardness. → The DLC films with low internal stress and high hardness can be acquired by Al incorporation. - Abstract: Metal incorporation is one of the most effective methods for relaxing internal stress in diamond-like carbon (DLC) films. It was reported that the chemical state of the incorporated metal atoms has a significant influence on the film internal stress. The doped atoms embedding in the DLC matrix without bonding with C atoms can reduce the structure disorder of the DLC films through bond angle distortion and thus relax the internal stress of the films. In present paper, Al atoms, which are inert to carbon, were incorporated into the DLC films deposited by a hybrid ion beams system comprising an anode-layer ion source and a magnetron sputtering unit. The film composition, microstructure and atomic bond structure were characterized using X-ray photoelectron spectroscopy, transmission electron microscopy and Raman spectroscopy. The internal stress, mechanical properties and tribogoical behavior were studied as a function of Al concentration using a stress-tester, nanoindentation and ball-on-disc tribo-tester, respectively. The results indicated that the incorporated Al atoms were dissolved in the DLC matrix without bonding with C atoms and the films exhibited the feature of amorphous carbon. The structure disorder of the films tended to decrease with Al atoms incorporation. This resulted in the distinct reduction of the internal stress in the films. All Al-DLC films exhibited a lower friction coefficient compared with pure DLC film. The formation of the

  5. Dosimetric variation due to CT inter-slice spacing in four-dimensional carbon beam lung therapy

    International Nuclear Information System (INIS)

    Kumagai, Motoki; Mori, Shinichiro; Kandatsu, Susumu; Baba, Masayuki; Sharp, Gregory C; Asakura, Hiroshi; Endo, Masahiro

    2009-01-01

    When CT data with thick slice thickness are used in treatment planning, geometrical uncertainty may induce dosimetric errors. We evaluated carbon ion dose variations due to different CT slice thicknesses using a four-dimensional (4D) carbon ion beam dose calculation, and compared results between ungated and gated respiratory strategies. Seven lung patients were scanned in 4D mode with a 0.5 mm slice thickness using a 256-multi-slice CT scanner. CT images were averaged with various numbers of images to simulate reconstructed images with various slice thicknesses (0.5-5.0 mm). Two scenarios were studied (respiratory-ungated and -gated strategies). Range compensators were designed for each of the CT volumes with coarse inter-slice spacing to cover the internal target volume (ITV), as defined from 4DCT. Carbon ion dose distribution was computed for each resulting ITV on the 0.5 mm slice 4DCT data. The accumulated dose distribution was then calculated using deformable registration for 4D dose assessment. The magnitude of over- and under-dosage was found to be larger with the use of range compensators designed with a coarser inter-slice spacing than those obtained with a 0.5 mm slice thickness. Although no under-dosage was observed within the clinical target volume (CTV) region, D95 remained at over 97% of the prescribed dose for the ungated strategy and 95% for the gated strategy for all slice thicknesses. An inter-slice spacing of less than 3 mm may be able to minimize dose variation between the ungated and gated strategies. Although volumes with increased inter-slice spacing may reduce geometrical accuracy at a certain respiratory phase, this does not significantly affect delivery of the accumulated dose to the target during the treatment course.

  6. Clinical evaluation of carbon-11-phenylephrine: MAO-sensitive marker of cardiac sympathetic neurons.

    Science.gov (United States)

    Raffel, D M; Corbett, J R; del Rosario, R B; Gildersleeve, D L; Chiao, P C; Schwaiger, M; Wieland, D M

    1996-12-01

    The sympathomimetic drug phenylephrine recently has been labeled with 11C for use in PET studies of cardiac sympathetic innervation. Previous reports using isolated perfused rat heart models indicate that phenylephrine is metabolized by intraneuronal monoamine oxidase (MAO). This report compares the imaging characteristics, neuronal selectivity and kinetics of (-)-[11C]phenylephrine (PHEN) to the structurally similar but MAO-resistant analog (-)-[11C]-meta-hydroxyephedrine (HED), an established heart neuronal marker. Fourteen healthy volunteers were studied with PET and PHEN. Ten had paired studies with HED; four of the 10 were scanned a second time with each tracer after oral administration of desipramine, a selective neuronal transport blocker. Hemodynamic and electrocardiographic responses were monitored. Blood levels of intact radiotracer and radiolabeled metabolites were determined from venous blood samples taken during the PET study. Myocardial retention indices for both tracers were calculated. No hemodynamic or electrocardiographic effects were observed with either tracer. PHEN showed reduced myocardial retention at 50 min compared to HED; however, image quality and uniformity of distribution were comparable. PHEN cleared from myocardium with a mean half-time of 59 +/- 5 min, while myocardial levels of HED remained constant. PHEN metabolites appeared in the blood approximately three times faster than HED metabolites. Desipramine pretreatment markedly reduced (> 60%) myocardial retention of both PHEN and HED. PHEN provides PET images of human heart comparable in quality and uniformity to HED. Like HED, PHEN localizes in the sympathetic nerves of the heart. However, the more rapid efflux of PHEN, that is likely mediated by MAO, may provide information on the functional status of cardiac sympathetic neurons unobtainable with HED.

  7. Properties of Lithium-11 and Carbon-22 at leading order in halo effective field theory

    Directory of Open Access Journals (Sweden)

    Acharya Bijaya

    2016-01-01

    Full Text Available We study the 11Li and 22C nuclei at leading order (LO in halo effective field theory (Halo EFT. Using the value of the 22C rms matter radius deduced in Ref. [1] as an input in a LO calculation, we simultaneously constrain the values of the two-neutron (2n separation energy of 22C and the virtual-state energy of the 20C−neutron system (hereafter denoted 21C. The 1−σ uncertainty of the input rms matter radius datum, along with the theory error estimated from the anticipated size of the higher-order terms in the Halo EFT expansion, gives an upper bound of about 100 keV for the 2n separation energy. We also study the electric dipole excitation of 2n halo nuclei to a continuum state of two neutrons and the core at LO in Halo EFT. We first compare our results with the 11Li data from a Coulomb dissociation experiment and obtain good agreement within the theoretical uncertainty of a LO calculation. We then obtain the low-energy spectrum of B(E1 of this transition at several different values of the 2n separation energy of 22C and the virtual-state energy of 21C. Our predictions can be compared to the outcome of an ongoing experiment on the Coulomb dissociation of 22C to obtain tighter constraints on the two- and three-body energies in the 22C system.

  8. Radiation absorbed dose estimates for [1-carbon-11]-glucose in adults: The effects of hyperinsulinemia

    International Nuclear Information System (INIS)

    Powers, W.J.

    1996-01-01

    As preparation for studies of blood-brain glucose transport in diabetes mellitus, radiation absorbed dose estimates from intravenous administration of [1- 11 C]-glucose for 24 internal organs, lens, blood and total body were calculated for three physiologic conditions: euinsulinemic euglycemia, hyperinsulinemic euglycemia and hyperinsulinemic hyperglycemia. Cumulated activities in blood, insulin-independent and insulin-dependent compartments were calculated from blood time-activity curves in normal human volunteers and macaques. Apportionment of cumulated activity to individual organs in insulin-dependent and insulin-independent compartments was based on previously published data. Absorbed doses were calculated with the computer program MIRDOSE 3 for the 70-kg adult phantom. S for blood was calculated separately. The heart wall, lungs and spleen were the organs receiving the highest dose. The effect of hyperinsulinemia was demonstrated by the increase in adsorbed dose to the muscle, heart and blood with a decrease to other internal organs. This effect was more pronounced during hyperinsulinemic hyperglycemia. Hyperinsulinemia produced a decrease in effective dose due to the decrease in cumulated activity in organs with specified weighting factors greater than 0.05. The effective dose per study for [1- 11 C]-glucose is comparable to that reported for 2-deoxy-[2- 18 F]-glucose. 43 refs., 1 fig., 4 tabs

  9. Effects of ion beam heating on Raman spectra of single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Hulman, Martin; Skakalova, Viera; Krasheninnikov, A. V.; Roth, S.

    2009-01-01

    Free standing films of single-wall carbon nanotubes were irradiated with energetic N + and C 4+ ions. The observed changes in the Raman line shape of the radial breathing mode and the G band of the C 4+ irradiated samples were similar to those found for a thermally annealed sample. We ascribe these changes to thermal desorption of volatile dopants from the initially doped nanotubes. A simple geometry of the experiment allows us to estimate the temperature rise by one-dimensional heat conductance equation. The calculation indicates that irradiation-mediated increase in temperature may account for the observed Raman spectra changes

  10. We keep on truckin': Trends in freight energy use and carbon emissions in 11 IEA countries

    International Nuclear Information System (INIS)

    Eom, Jiyong; Schipper, Lee; Thompson, Lou

    2012-01-01

    Based on detailed national and international data on freight transportation, we analyze trends in freight CO 2 emissions in 11 IEA countries from the earliest year of data availability to 2007–2010. The cross-country comparison of the freight transportation sector indicates that per capita CO 2 emissions span a wide range and are mostly determined by local needs without full knowledge or coordination with policies and practices in other countries. Over the last several decades, while many developed countries have experienced decreased coupling between total freight activity (measured in tonne-km) and income, no major indication of decreased coupling between trucking and income was found. Rather, the coupling has been strengthened in many countries due to a continued increase in the share of trucking in total freight activity. The energy intensity of trucking has exhibited very large variation among the countries, and its recent international trends are mixed, providing greater challenges to reduce freight CO 2 emissions. Modal shift toward rail away from truck presents a sizeable opportunity to reduce freight CO 2 emissions, although the potential gain varies widely among the countries. - Highlights: ► We analyze trends in freight CO 2 emissions in 11 IEA countries. ► Many of them experienced decreased coupling between freight and income. ► No major indication of decoupling was found between trucking and income. ► The energy intensity of trucking exhibited very large variation. ► The trends of trucking energy intensity are mixed. ► There is a huge opportunity of reducing emissions by shifting toward rail.

  11. Histological and elemental changes in the rat brain after local irradiation with carbon ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Sentaro; Sun, Xue-Zhi; Kubota, Yoshihisa; Takai, Nobuhiko; Nojima, Kumie [National Inst. of Radiological Sciences, Chiba (Japan)

    2002-06-01

    The left cerebral hemispheres of adult Sprague-Dawley rat brains were irradiated at doses of 30, 50, or 100 Gy with charged carbon particles (290 MeV/nucleon; 5 mm spread-out Bragg peak). The spread-out Bragg peak used here successfully and satisfactorily retained its high-dose localization in the defined region. A histological examination showed that necrotic tissue damage, hemorrhage in the thalamus, and vasodilatations around the necrotic region were induced at 8 weeks after 100 Gy irradiation. The regions with tissue damage correlated well with those expected from the radiation-dose distribution, indicating an advantage of charged carbon particles for irradiating restricted brain regions. An X-ray fluorescent analysis demonstrated a decrease in the concentrations of K and P, and an increase in the concentrations of Cl, Fe, Zn in the damaged region at 8 weeks post-irradiation, though no significant changes were observed before 4 weeks of post-irradiation. This may indicate that even the very high radiation doses used here did not induce acute and immediate neuronal cell death, in contrast with ischemic brain injury where acute neuronal cell death occurred and the elemental concentrations changed within a day after the induction of ischemia. (author)

  12. Electrochemical Corrosion Behavior of Low Carbon I-Beam Steels In Simulated Yucca Mountain Repository Environment

    Energy Technology Data Exchange (ETDEWEB)

    Arjunan, Venugopal; Lamb, Joshua; Chandra, Dhanesh; Daemen, Jack; Jones, Denny A.; Engelhard, Mark H.; Lea, Alan S.

    2005-04-01

    The electrochemical corrosion behavior of low carbon steel was examined in a simulated Yucca Mountain (YM) ground water by varying the electrolyte concentration and temperature under aerated and deaerated conditions. The results show that in deaerated conditions, the corrosion rate is low in the order of 0.6 to 4.5mpy, between 25 to 85 C, respectively. However, in aerated conditions the measured rates were expectedly very high, in the order of 3-55mpy in the above mentioned temperature levels. The rates initially increased up to 45 C, and a decreasing trend was observed with further increase in temperature from 65 to 85 C. The maximum corrosion rate was occurred at 45 C (54.5mpy). The low corrosion rates observed in all deaerated conditions, and in aerated solutions at higher temperatures were due to the preferential adsorption of Mg-species on the steel surface, as identified by XPS analyses. The results also indicate possible localized corrosion behavior of carbon steel in aerated conditions up to 45 C.

  13. Electrochemical Corrosion Behavior of Low Carbon I-Beam Steels In Simulated Yucca Mountain Repository Environment

    International Nuclear Information System (INIS)

    Arjunan, Venugopal; Lamb, Joshua; Chandra, Dhanesh; Daemen, Jack; Jones, Denny A.; Engelhard, Mark H.; Lea, Alan S.

    2005-01-01

    The electrochemical corrosion behavior of low carbon steel was examined in a simulated Yucca Mountain (YM) ground water by varying the electrolyte concentration and temperature under aerated and deaerated conditions. The results show that in deaerated conditions, the corrosion rate is low in the order of 0.6 to 4.5mpy, between 25 to 85 C, respectively. However, in aerated conditions the measured rates were expectedly very high, in the order of 3-55mpy in the above mentioned temperature levels. The rates initially increased up to 45 C, and a decreasing trend was observed with further increase in temperature from 65 to 85 C. The maximum corrosion rate was occurred at 45 C (54.5mpy). The low corrosion rates observed in all deaerated conditions, and in aerated solutions at higher temperatures were due to the preferential adsorption of Mg-species on the steel surface, as identified by XPS analyses. The results also indicate possible localized corrosion behavior of carbon steel in aerated conditions up to 45 C

  14. Carbon-11 epidepride: a suitable radioligand for PET investigation of striatal and extrastriatal dopamine D{sub 2} receptors

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver; Halldin, Christer E-mail: christer.halldin@neuro.ks.se; Dolle, Frederic; Swahn, Carl-Gunnar; Olsson, Hans; Lundkvist, Per Karlsson; Hall, Haakan; Sandell, Johan; Vaufrey, Camilla; Loc' h, Christian; Franzoise; Crouzel, Christian; Maziere, Bernard; Farde, Lars

    1999-07-01

    Epidepride {l_brace}(S)-(-)-N-([1-ethyl-2-pyrrolidinyl]methyl)-5-iodo-2,3-dimethoxybenzamide= {r_brace} binds with a picomolar affinity (K{sub i}=24 pM) to the dopamine D{sub 2} receptor. Iodine-123-labeled epidepride has been used previously to study striatal and extrastriatal dopamine D{sub 2} receptors with single photon emission computed tomography (SPECT). Our aim was to label epidepride with carbon-11 for comparative quantitative studies between positron emission tomography (PET) and SPECT. Epidepride was synthesized from its bromo-analogue FLB 457 via the corresponding trimethyl-tin derivative. In an alternative synthetic pathway, the corresponding substituted benzoic acid was reacted with the optically pure aminomethylpyrrolidine-derivative. Demethylation of epidepride gave the desmethyl-derivative, which was reacted with [{sup 11}C]methyl triflate. Total radiochemical yield was 40-50% within a total synthesis time of 30 min. The specific radioactivity at the end of synthesis was 37-111 GBq/{mu}mol (1,000-3,000 Ci/mmol). Human postmortem whole-hemisphere autoradiography demonstrated dense binding in the caudate putamen, and also in extrastriatal areas such as the thalamus and the neocortex. The binding was inhibited by unlabeled raclopride. PET studies in a cynomolgus monkey demonstrated high uptake in the striatum and in several extrastriatal regions. At 90 min after injection, uptake in the striatum, thalamus and neocortex was about 11, 4, and 2 times higher than in the cerebellum, respectively. Pretreatment experiment with unlabeled raclopride (1 mg/kg) inhibited 50-70% of [{sup 11}C]epidepride binding. The fraction of unchanged [{sup 11}C]epidepride in monkey plasma determined by a gradient high performance liquid chromatography (HPLC) method was about 30% of the total radioactivity at 30 min after injection of [{sup 11}C]epidepride. The availability of [{sup 11}C]epidepride allows the PET-verification of the data obtained from quantitation studies with

  15. Comparison Between In-Beam and Offline Positron Emission Tomography Imaging of Proton and Carbon Ion Therapeutic Irradiation at Synchrotron- and Cyclotron-Based Facilities

    International Nuclear Information System (INIS)

    Parodi, Katia; Bortfeld, Thomas; Haberer, Thomas

    2008-01-01

    Purpose: The benefit of using dedicated in-beam positron emission tomography (PET) detectors in the treatment room instead of commercial tomographs nearby is an open question. This work quantitatively compares the measurable signal for in-beam and offline PET imaging, taking into account realistic acquisition strategies at different ion beam facilities. Both scenarios of pulsed and continuous irradiation from synchrotron and cyclotron accelerators are considered, because of their widespread use in most carbon ion and proton therapy centers. Methods and Materials: A mathematical framework is introduced to compare the time-dependent amount and spatial distribution of decays from irradiation-induced isotope production. The latter is calculated with Monte Carlo techniques for real proton treatments of head-and-neck and paraspinal tumors. Extrapolation to carbon ion irradiation is based on results of previous phantom experiments. Biologic clearance is modeled taking into account available data from previous animal and clinical studies. Results: Ratios between the amount of physical decays available for in-beam and offline detection range from 40% to 60% for cyclotron-based facilities, to 65% to 110% (carbon ions) and 94% to 166% (protons) at synchrotron-based facilities, and increase when including biologic clearance. Spatial distributions of decays during irradiation exhibit better correlation with the dose delivery and reduced influence of biologic processes. Conclusions: In-beam imaging can be advantageous for synchrotron-based facilities, provided that efficient PET systems enabling detection of isotope decays during beam extraction are implemented. For very short (<2 min) irradiation times at cyclotron-based facilities, a few minutes of acquisition time after the end of irradiation are needed for counting statistics, thus affecting patient throughput

  16. High energy ion beam induced modifications in diamond and diamond like carbon thin films

    International Nuclear Information System (INIS)

    Dilawar, N.; Sah, S.; Mehta, B.R.; Vankar, V.D.

    1996-01-01

    Diamond and DLC films deposited using hot-filament chemical vapour deposition technique at various parameters were irradiated with 50 MeV Si 4+ ions. The resulting microstructural changes were studied using X-ray diffraction and scanning electron microscopy. All the samples showed the development of β-SiC and hexagonal carbon phases at the expense of the diamond/DLC phase. The ERD analysis was carried out to determine the hydrogen concentration and its distribution in DLC films. The absolute hydrogen concentration in DLC samples is of the order of 10 22 atoms/cm 3 which gets depleted on irradiation. The DLC samples show a clear dependence of hydrogen content on the deposition parameters. (author)

  17. Mathematical modeling of enzyme production using Trichoderma harzianum P49P11 and sugarcane bagasse as carbon source.

    Science.gov (United States)

    Gelain, Lucas; da Cruz Pradella, José Geraldo; da Costa, Aline Carvalho

    2015-12-01

    A mathematical model to describe the kinetics of enzyme production by the filamentous fungus Trichoderma harzianum P49P11 was developed using a low cost substrate as main carbon source (pretreated sugarcane bagasse). The model describes the cell growth, variation of substrate concentration and production of three kinds of enzymes (cellulases, beta-glucosidase and xylanase) in different sugarcane bagasse concentrations (5; 10; 20; 30; 40 gL(-1)). The 10 gL(-1) concentration was used to validate the model and the other to parameter estimation. The model for enzyme production has terms implicitly representing induction and repression. Substrate variation was represented by a simple degradation rate. The models seem to represent well the kinetics with a good fit for the majority of the assays. Validation results indicate that the models are adequate to represent the kinetics for a biotechnological process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Taking out one billion tones of carbon: the magic of China's 11thFive-Year Plan

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jiang; Zhou, Nan; Levine, Mark D.; Fridley, David

    2007-05-01

    China's 11th Five-Year Plan (FYP) sets an ambitious targetfor energy-efficiency improvement: energy intensity of the country sgross domestic product (GDP) should be reduced by 20 percent from 2005 to2010 (NDRC, 2006). This is the first time that a quantitative and bindingtarget has been set for energy efficiency, and signals a major shift inChina's strategic thinking about its long-term economic and energydevelopment. The 20 percent energy intensity target also translates intoan annual reduction of over one billion tons of CO2 by 2010, making theChinese effort one of most significant carbon mitigation effort in theworld today. While it is still too early to tell whether China willachieve this target, this paper attempts to understand the trend inenergy intensity in China and to explore a variety of options towardmeeting the 20 percent target using a detailed endues energymodel.

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

    Energy Technology Data Exchange (ETDEWEB)

    Osinga-Blaettermann, Julia-Maria

    2016-12-20

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

  20. Facile synthesis of carbon-11-labeled arylpiperazinylthioalkyl derivatives as new PET radioligands for imaging of 5-HT{sub 1A}R

    Energy Technology Data Exchange (ETDEWEB)

    Gao Mingzhang; Wang Min [Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, L3-208, Indianapolis, IN 46202-2111 (United States); Zheng Qihuang, E-mail: qzheng@iupui.edu [Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, L3-208, Indianapolis, IN 46202-2111 (United States)

    2012-03-15

    Carbon-11-labeled arylpiperazinylthioalkyl derivatives, 2-((4-(4-(2-[{sup 11}C]methoxyphenyl)piperazin-1-yl)butyl)thio)benzo[d]oxazole ([{sup 11}C]5a), 2-((4-(4-(2-[{sup 11}C]methoxyphenyl)piperazin-1-yl)butyl)thio)-5,7-dimethylbenzo [d]oxazole ([{sup 11}C]5c), 2-((4-(4-(2-[{sup 11}C]methoxyphenyl)piperazin-1-yl)butyl)thio)benzo[d]thiazole ([{sup 11}C]5e), 2-((6-(4-(2-[{sup 11}C]methoxyphenyl)piperazin-1-yl)hexyl)thio)benzo[d]oxazole ([{sup 11}C]5g), 2-((6-(4-(2-[{sup 11}C]methoxyphenyl)piperazin-1-yl)hexyl)thio)-5,7-dimethylbenzo [d]oxazole ([{sup 11}C]5i), and 2-((6-(4-(2-[{sup 11}C]methoxyphenyl)piperazin-1-yl)hexyl)thio)benzo[d]thiazole ([{sup 11}C]5k), were prepared from their corresponding phenol precursors with [{sup 11}C]CH{sub 3}OTf through O-[{sup 11}C]methylation and isolated by a simplified solid-phase extraction (SPE) method using a Sep-Pak Plus C18 cartridge in 50-60% (n=5) radiochemical yields based on [{sup 11}C]CO{sub 2} and decay corrected to end of bombardment (EOB). The overall synthesis time from EOB was 23 min, the radiochemical purity was >99%, and the specific activity at end of synthesis (EOS) was 277.5{+-}92.5 GBq/{mu}mol (n=5). - Highlights: Black-Right-Pointing-Pointer New arylpiperazinylthioalkyl derivatives were synthesized. Black-Right-Pointing-Pointer New carbon-11-labeled arylpiperazinylthioalkyl derivatives were synthesized. Black-Right-Pointing-Pointer Simplified solid-phase extraction (SPE) method was employed in radiosynthesis.

  1. Impact of substrate temperature on the incorporation of carbon-related defects and mechanism for semi-insulating behavior in GaN grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Armstrong, A.; Poblenz, C.; Green, D.S.; Mishra, U.K.; Speck, J.S.; Ringel, S.A.

    2006-01-01

    The electrical conductivity and deep level spectrum of GaN grown by molecular beam epitaxy and codoped with carbon and silicon were investigated for substrate temperatures T s of 650 and 720 deg. C as a function relative carbon and silicon doping levels. With sufficiently high carbon doping, semi-insulating behavior was observed for films grown at both temperatures, and growth at T s =720 deg. C enhanced the carbon compensation ratio. Similar carbon-related band gap states were observed via deep level optical spectroscopy for films grown at both substrate temperatures. Due to the semi-insulating nature of the films, a lighted capacitance-voltage technique was required to determine individual deep level concentrations. Carbon-related band gap states underwent substantial redistribution between deep level and shallow acceptor configurations with change in T s . In light of a T s dependence for the preferential site of carbon incorporation, a model of semi-insulating behavior in terms of carbon impurity state incorporation mediated by substrate temperature is proposed

  2. Annealing effects of carbon fiber-reinforced epoxy resin composites irradiated by electron beams

    International Nuclear Information System (INIS)

    Udagawa, Akira; Sasuga, Tuneo; Ito, Hiroshi; Hagiwara, Miyuki

    1987-01-01

    Carbon cloth-reinforced epoxy resin composites were irradiated with 2 MeV electrons at room temperature and then annealed in air for 2 h at temperatures up to 180 deg C. A considerable decrease in the three-point bending strength occurred when the irradiated composites were annealed in the temperature range of 115 - 135 deg C which is below the glass transition temperature T g of the matrix resin, while the bending strength remained unchanged up to 180 deg C for the unirradiated composites. In the dynamic viscoelastic spectra of the irradiated matrix, a new relaxation appeared at the temperature extending from 50 deg C to just below the matrix T g and disappeared on annealing for 2 h at 135 deg C. Annealing also decreased the concentration of free radicals existing stably in the irradiated matrix at room temperature. After annealing, a large amount of clacks and voids were observed in the fractography of the composites by scanning electron microscopy. These results indicate: (1) Annealing brings about rearrangement of the radiation-induced molecular chain scission in the matrix; (2) The bending strength of the irradiated composites decreased owing to the increased brittleness of the matrix by annealing. (author)

  3. Low-dose ion-based transmission radiography and tomography for optimization of carbon ion-beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Magallanes Hernandez, Lorena

    2017-02-21

    In the last few decades, ion-beam radiotherapy has emerged as a highly effective tumor treatment modality. Its success relies on the capability to precisely confine the prescribed dose within the target volume, due to the inverted depth-dose profile and the finite range featured by charged particles. However, to fully exploit the physical and biological advantages of ion-beams, it is necessary to prioritize on innovative imaging techniques to monitor the ion-range inside the patient. Main range uncertainties result from X-ray-based calibration of the ion relative Water Equivalent Path Length (rWEPL) during the planning phase, and patient anatomical or positioning variation during the treatment. In this thesis, low-dose carbon-ion transmissionimaging performed with a Residual Range Detector (RRD) is proposed as imaging strategy for actively scanned beam delivery facilities. It enables the verification of the beam range and the patient positioning with ion-radiographies (iRAD), and ion computed tomographies (iCT) can directly provide the ion stopping-power of the traversed tissue for treatment planning purposes. First experimental investigations aiming to minimize the imaging dose to the object are presented. The performance of the integration-mode multi-channel array of 61 parallel-plate ionization chambers (PPICs), interleaved with 3 mm thickness PMMA slabs, was thoroughly investigated for low-fluence irradiation. This characterization has been pursued in terms of beam-monitoring performance at the Heidelberg Ion-beam Therapy Center (HIT, Heidelberg, Germany), RRD signal-to-noise ratio (SNR), RRD charge-collection efficiency and drift voltage applied to the PPICs. Pixel-wise metrics for signal quality evaluation based on specific channel-charge features have been developed to support the visual assessment of the acquired images. Phantoms of different complexity and tissue-equivalent composition were imaged with high (5000 primaries per raster-scanning point (RP

  4. Low-dose ion-based transmission radiography and tomography for optimization of carbon ion-beam therapy

    International Nuclear Information System (INIS)

    Magallanes Hernandez, Lorena

    2017-01-01

    In the last few decades, ion-beam radiotherapy has emerged as a highly effective tumor treatment modality. Its success relies on the capability to precisely confine the prescribed dose within the target volume, due to the inverted depth-dose profile and the finite range featured by charged particles. However, to fully exploit the physical and biological advantages of ion-beams, it is necessary to prioritize on innovative imaging techniques to monitor the ion-range inside the patient. Main range uncertainties result from X-ray-based calibration of the ion relative Water Equivalent Path Length (rWEPL) during the planning phase, and patient anatomical or positioning variation during the treatment. In this thesis, low-dose carbon-ion transmissionimaging performed with a Residual Range Detector (RRD) is proposed as imaging strategy for actively scanned beam delivery facilities. It enables the verification of the beam range and the patient positioning with ion-radiographies (iRAD), and ion computed tomographies (iCT) can directly provide the ion stopping-power of the traversed tissue for treatment planning purposes. First experimental investigations aiming to minimize the imaging dose to the object are presented. The performance of the integration-mode multi-channel array of 61 parallel-plate ionization chambers (PPICs), interleaved with 3 mm thickness PMMA slabs, was thoroughly investigated for low-fluence irradiation. This characterization has been pursued in terms of beam-monitoring performance at the Heidelberg Ion-beam Therapy Center (HIT, Heidelberg, Germany), RRD signal-to-noise ratio (SNR), RRD charge-collection efficiency and drift voltage applied to the PPICs. Pixel-wise metrics for signal quality evaluation based on specific channel-charge features have been developed to support the visual assessment of the acquired images. Phantoms of different complexity and tissue-equivalent composition were imaged with high (5000 primaries per raster-scanning point (RP

  5. Study of induced reactions by a secondary beam of 11Be in Be, Ti and Au targets

    International Nuclear Information System (INIS)

    Dogny, S.

    1992-01-01

    In the last decade, new phenomena arised from nuclear reaction studies of neutron-rich light nuclei produced by projectile fragmentation. In this work, first we will recall briefly some aspects of these studies, in particular the two-neutron halo for nuclei whose binding energy of the two last neutrons is low. Secondly, we will describe the experiment which aims to study 11 Be reactions on Be, Ti and Be targets. The results of this experiment show the presence of a one-neutron halo, corresponding to a high dissociation cross-section for the three targets. We will show that three mechanisms, Coulomb dissociation for heavy targets, diffraction-and absorption-dissociation for light targets, account satisfactorily for reactions leading to 10 Be

  6. 18 F-FDG PET/CT for planning external beam radiotherapy alters therapy in 11% of 581 patients.

    Science.gov (United States)

    Birk Christensen, Charlotte; Loft-Jakobsen, Annika; Munck Af Rosenschöld, Per; Højgaard, Liselotte; Roed, Henrik; Berthelsen, Anne K

    2018-03-01

    18 F-FDG PET/CT (FDG PET/CT) used in radiotherapy planning for extra-cerebral malignancy may reveal metastases to distant sites that may affect the choice of therapy. To investigate the role of FDG PET/CT on treatment strategy changes induced by the use of PET/CT as part of the radiotherapy planning. 'A major change of treatment strategy' was defined as either including more lesions in the gross tumour volume (GTV) distant from the primary tumour or a change in treatment modalities. The study includes 581 consecutive patients who underwent an FDG PET/CT scan for radiotherapy planning in our institution in the year 2008. All PET/CT scans were performed with the patient in treatment position with the use of immobilization devices according to the intended radiotherapy treatment. All scans were evaluated by a nuclear medicine physician together with a radiologist to delineate PET-positive GTV (GTV-PET). For 63 of the patients (11%), the PET/CT simulation scans resulted in a major change in treatment strategy because of the additional diagnostic information. Changes were most frequently observed in patients with lung cancer (20%) or upper gastrointestinal cancer (12%). In 65% of the patients for whom the PET/CT simulation scan revealed unexpected dissemination, radiotherapy was given - changed (n = 38) or unchanged (n = 13) according to the findings on the FDG PET/CT. Unexpected dissemination on the FDG PET/CT scanning performed for radiotherapy planning caused a change in treatment strategy in 11% of 581 patients. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  7. Test Measurements of a 20 ms-1 Carbon Wire Beam Scanner

    CERN Document Server

    De Freitas, J; Emery, J; Herranz Alvarez, J F; Koujili, M; Ramos, D; Sapinski, M; Ait-Amira, Y; Djerdir, A

    2011-01-01

    This paper pre­sents the de­sign of the ac­tu­a­tor for the fast and high ac­cu­ra­cy Wire Scan­ner sys­tem. The ac­tu­a­tor con­sists of a ro­tary brushless syn­chronous motor with the per­ma­nent mag­net rotor in­stalled in­side the vac­u­um cham­ber and the sta­tor in­stalled out­side. The fork, per­ma­nent mag­net rotor and two an­gu­lar po­si­tion sen­sors are mount­ed on the same axis and lo­cat­ed in­side the beam vac­u­um cham­ber. The system has to re­sist a bake-out tem­per­a­ture of 200 C and ion­iz­ing radi­a­tion up to tenths of kGy/year. Max­i­mum wire trav­el­ling speed of 20 m/s and a po­si­tion mea­sure­ment ac­cu­ra­cy of 4 um is re­quired. Therefore, the sys­tem must avoid gen­er­at­ing vi­bra­tion and electromagnet­ic in­ter­fer­ence. A dig­i­tal feed­back con­troller will allow max­i­mum flex­i­bil­i­ty for the loop pa­ram­e­ters and feeds the 3-phase lin­ear power driv­er. The per­for­mance of the pr...

  8. Irradiation With Carbon Ion Beams Induces Apoptosis, Autophagy, and Cellular Senescence in a Human Glioma-Derived Cell Line

    International Nuclear Information System (INIS)

    Jinno-Oue, Atsushi; Shimizu, Nobuaki; Hamada, Nobuyuki; Wada, Seiichi; Tanaka, Atsushi; Shinagawa, Masahiko; Ohtsuki, Takahiro; Mori, Takahisa; Saha, Manujendra N.; Hoque, Ariful S.; Islam, Salequl; Kogure, Kimitaka; Funayama, Tomoo; Kobayashi, Yasuhiko

    2010-01-01

    Purpose: We examined biological responses of human glioma cells to irradiation with carbon ion beams (C-ions). Methods and Materials: A human glioma-derived cell line, NP-2, was irradiated with C-ions. Apoptotic cell nuclei were stained with Hoechst 33342. Induction of autophagy was examined either by staining cells with monodansylcadaverine (MDC) or by Western blotting to detect conversion of microtuble-associated protein light chain 3 (MAP-LC3) (LC3-I) to the membrane-bound form (LC3-II). Cellular senescence markers including induction of senescence-associated β-galactosidase (SA-β-gal) were examined. The mean telomere length of irradiated cells was determined by Southern blot hybridization. Expression of tumor suppressor p53 and cyclin/cyclin-dependent kinase inhibitor p21 WAF1/CIP1 in the irradiated cells was analyzed by Western blotting. Results: When NP-2 cells were irradiated with C-ions at 6 Gy, the major population of the cells died of apoptosis and autophagy. The residual fraction of attached cells ( WAF1/CIP1 was induced in NP-2 cells after irradiation. Furthermore, we found that irradiation with C-ions induced cellular senescence in a human glioma cell line lacking functional p53. Conclusions: Irradiation with C-ions induced apoptosis, autophagy, and cellular senescence in human glioma cells.

  9. The ''in vivo'' distribution of carbon 11 labeled-nicotine in animals. A method suitable for use in man

    International Nuclear Information System (INIS)

    Maziere, M.; Berger, G.; Plummer, D.; Comar, D.; Masse, R.

    1978-01-01

    A method is described to label nicotine with carbon 11. A hundred millicuries can be obtained, in 45 minutes, with a high specific activity. This labeling of nicotine has allowed an ''in vivo'' study of the distribution of this very toxic drug in animals. Five minutes after injection in rabbits or monkeys, it was shown with a gamma camera or with a positron camera that the radioactivity was very rapidly distributed throughout the tissues especially in brain, lungs and kidneys. 11 C-nicotine readily penetrates the blood-brain barrier and the brain radioactivity decreases very sharply with time. The eyes however retained activity, possibly in the retina. Unfortunately the monkey is not the ideal subject for 11 C-nicotine brain study because: the brain is small, considering the resolution of the cameras and the cerebral lobes are also quite overlaped in this animal; Japanese authors have shown that compared with dogs the nicotine brain uptake is lower, due to the high affinity of nicotine for skeletal muscle which occupies approximately forty to fifty % of the body weight of the monkey. Also in monkeys, the nicotine destruction is faster than in dogs because there is a higher enzyme nicotine metabolizing activity in the liver of this animal. The differences observed between various animals studies using nicotine indicate that we should not draw any firm conclusions about the behaviour of this drug in humans. In order to do so, examinations must be conducted in man and the method described in spite of its limitations provides a means for such a study

  10. Electron beam generation and structure of defects in carbon and boron nitride nano-tubes

    Energy Technology Data Exchange (ETDEWEB)

    Zobelli, A

    2007-10-15

    The nature and role of defects is of primary importance to understand the physical properties of C and BN (boron nitride) single walled nano-tubes (SWNTs). Transmission electron microscopy (TEM) is a well known powerful tool to study the structure of defects in materials. However, in the case of SWNTs, the electron irradiation of the TEM may knock out atoms. This effect may alter the native structure of the tube, and has also been proposed as a potential tool for nano-engineering of nano-tubular structures. Here we develop a theoretical description of the irradiation mechanism. First, the anisotropy of the emission energy threshold is obtained via density functional based calculations. Then, we numerically derive the total Mott cross section for different emission sites of carbon and boron nitride nano-tubes with different chiralities. Using a dedicated STEM (Scanning Transmission Electron Microscope) microscope with experimental conditions optimised on the basis of derived cross-sections, we are able to control the generation of defects in nano-tubular systems. Either point or line defects can be obtained with a spatial resolution of a few nanometers. The structure, energetics and electronics of point and line defects in BN systems have been investigated. Stability of mono- and di- vacancy defects in hexagonal boron nitride layers is investigated, and their activation energies and reaction paths for diffusion have been derived using the nudged elastic band method (NEB) combined with density functional based techniques. We demonstrate that the appearance of extended linear defects under electron irradiation is more favorable than a random distribution of point defects and this is due to the existence of preferential sites for atom emission in the presence of pre-existing defects, rather than thermal vacancy nucleation and migration. (author)

  11. Electron beam generation and structure of defects in carbon and boron nitride nano-tubes

    International Nuclear Information System (INIS)

    Zobelli, A.

    2007-10-01

    The nature and role of defects is of primary importance to understand the physical properties of C and BN (boron nitride) single walled nano-tubes (SWNTs). Transmission electron microscopy (TEM) is a well known powerful tool to study the structure of defects in materials. However, in the case of SWNTs, the electron irradiation of the TEM may knock out atoms. This effect may alter the native structure of the tube, and has also been proposed as a potential tool for nano-engineering of nano-tubular structures. Here we develop a theoretical description of the irradiation mechanism. First, the anisotropy of the emission energy threshold is obtained via density functional based calculations. Then, we numerically derive the total Mott cross section for different emission sites of carbon and boron nitride nano-tubes with different chiralities. Using a dedicated STEM (Scanning Transmission Electron Microscope) microscope with experimental conditions optimised on the basis of derived cross-sections, we are able to control the generation of defects in nano-tubular systems. Either point or line defects can be obtained with a spatial resolution of a few nanometers. The structure, energetics and electronics of point and line defects in BN systems have been investigated. Stability of mono- and di- vacancy defects in hexagonal boron nitride layers is investigated, and their activation energies and reaction paths for diffusion have been derived using the nudged elastic band method (NEB) combined with density functional based techniques. We demonstrate that the appearance of extended linear defects under electron irradiation is more favorable than a random distribution of point defects and this is due to the existence of preferential sites for atom emission in the presence of pre-existing defects, rather than thermal vacancy nucleation and migration. (author)

  12. Effects of radioprotectors on mutation in cultured mammalian cells by carbon beam

    International Nuclear Information System (INIS)

    Waldren, C.A.; Vannais, D.B.; Ueno, A.M.; Tatsumi, K.

    2004-01-01

    The project goal is understand genotoxic effects of high linear energy transfer (LET) radiations, e.g. carbon, 290 MeV/nucleon: LET=100 KeV/μm [C290], and to identify chemicals that can prevent or decrease such pathologies in cultured cells and in exposed humans. We have now quantified effects of C290-induced genotoxicity of several chemicals including WR-1065, cimetidine, lycopene, RibCys [(R, S)-D-ribo(1', 2', 3', 4'-Tetrahydroxybutyl)-thiazolidine-4(R)-ca riboxylic acid, N-acetyl cysteine (NAC), Dimethyl sulfoxide (DMSO) and vitamin C, and combinations of DMSO plus Vitamin C. In vitro, vitamin C showed the most promise. It significantly reduced mutant induction by C290 and also reduced the yield of mutants displaying the cancer-related property of genomic instability even when added after radiation. Unfortunately vitamin C was less effective at doses below 5 mM, which is too high for use in humans. So we are turning to using non-toxic levels of vitamin C in combination with other chemicals. Our recent preliminary results and those of Dr. J. Kumagai indicate that NAC, at doses well tolerated by humans and which scavenge classical hydroxyl radicals, also effectively scavenge mutagenic, long-lived radicals (LLR). We plan, therefore, to evaluate the combined effect of NAC + vitamin C on X-ray mutagenicity (but not initially at Heavy Ion Medical Accelerator in Chiba (HIMAC)). If these experiments look promising we would like to propose experiments with high LET radiation at HIMAC in collaboration with Dr. Kumagai. (author)

  13. Beam-Beam Effects

    International Nuclear Information System (INIS)

    Herr, W; Pieloni, T

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities

  14. Computational modelling of a non-viscous fluid flow in a multi-walled carbon nanotube modelled as a Timoshenko beam

    International Nuclear Information System (INIS)

    Khosravian, N; Rafii-Tabar, H

    2008-01-01

    In the design of nanotube-based fluidic devices, a critical issue is the effect of the induced vibrations in the nanotube arising from the fluid flow, since these vibrations can promote structural instabilities, such as buckling transitions. It is known that the induced resonant frequencies depend on the fluid flow velocity in a significant manner. We have studied, for the first time, the flow of a non-viscous fluid in stubby multi-walled carbon nanotubes, using the Timoshenko classical beam theory to model the nanotubes as a continuum structure. We have obtained the variations of the resonant frequencies with the fluid flow velocity under several experimentally interesting boundary conditions and aspect ratios of the nanotube. The main finding from our work is that, compared to an Euler-Bernoulli classical beam model of a nanotube, the Timoshenko beam predicts the loss of stability at lower fluid flow velocities

  15. Computational modelling of a non-viscous fluid flow in a multi-walled carbon nanotube modelled as a Timoshenko beam

    Energy Technology Data Exchange (ETDEWEB)

    Khosravian, N; Rafii-Tabar, H [Computational Physical Sciences Research Laboratory, Department of Nano-Science, Institute for Research in Fundamental Sciences (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of)], E-mail: rafii-tabar@nano.ipm.ac.ir

    2008-07-09

    In the design of nanotube-based fluidic devices, a critical issue is the effect of the induced vibrations in the nanotube arising from the fluid flow, since these vibrations can promote structural instabilities, such as buckling transitions. It is known that the induced resonant frequencies depend on the fluid flow velocity in a significant manner. We have studied, for the first time, the flow of a non-viscous fluid in stubby multi-walled carbon nanotubes, using the Timoshenko classical beam theory to model the nanotubes as a continuum structure. We have obtained the variations of the resonant frequencies with the fluid flow velocity under several experimentally interesting boundary conditions and aspect ratios of the nanotube. The main finding from our work is that, compared to an Euler-Bernoulli classical beam model of a nanotube, the Timoshenko beam predicts the loss of stability at lower fluid flow velocities.

  16. Synthesis of a sugar-organometallic compound 1,1 Prime -difurfurylferrocene and its microwave preparation of carbon/iron oxide nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Shanyu, E-mail: syzhao65@gmail.com [School of Environmental and Safty Engineering, Changzhou University, Changzhou, Jiangsu 213164 (China); Department of Chemistry, Brown University, Providence, RI 02912-9108 (United States); Cooper, Daniel C. [Department of Chemistry, Brown University, Providence, RI 02912-9108 (United States); Xu, Haixun [Institute of Building Materials, Dalian University of Technology, Dalian, Liaoning 116024 (China); Zhu Pinghua [School of Environmental and Safty Engineering, Changzhou University, Changzhou, Jiangsu 213164 (China); Suggs, J. William, E-mail: j_suggs@brown.edu [Department of Chemistry, Brown University, Providence, RI 02912-9108 (United States)

    2013-01-01

    Graphical abstract: In order to synthesize a carbon-metal or metal oxide combination sphere, carbonaceous resource furfural was introduced, which was nucleophilic treated with 1,1 Prime -dilithioferrocene to form a sugar-organometallic compound: ferrocenyl monosaccharide derivative 1,1 Prime -difurfurylferrocene, which can be hydrothermally treated in a microwave reactor to give 300-500 nm microspheres with the {alpha}-Fe{sub 2}O{sub 3} or Fe{sub 3}O{sub 4} formed on the surface, which may be favorable for new magnetic materials preparation or instead of iron with other metal ions, versatile carbon/metal composites will be possibly synthesized for catalysis, drug delivery and magnetic uses. Highlights: Black-Right-Pointing-Pointer We synthesized 1,1 Prime -difurfurylferrocene by nucleophilic treating furfural with 1,1 Prime -dilithioferrocene. Black-Right-Pointing-Pointer 1,1 Prime -Difurfurylferrocene can be hydrothermally treated by microwave to give microspheres with iron oxides on the surface. Black-Right-Pointing-Pointer 1,1 Prime -Difurfurylferrocene has 2 reactive furanose units, which form carbonspheres and ferrocenyl can give iron oxides. Black-Right-Pointing-Pointer REDOX atmosphere influences the coating structures. - Abstract: In order to synthesize a carbon-metal or metal oxide combination sphere, carbonaceous resource furfural 1 was introduced, which was nucleophilic treated with 1,1 Prime -dilithioferrocene 2 to form a sugar-organometallic compound: ferrocenyl monosaccharide derivative 1,1 Prime -difurfurylferrocene 3. 1,1 Prime -Difurfurylferrocene 3 can be hydrothermally treated in a microwave reactor to give 300-500 nm microspheres with the {alpha}-Fe{sub 2}O{sub 3} or Fe{sub 3}O{sub 4} nanocrystals formed on the surface, which may be favorable for new magnetic materials preparation or instead of iron with other metal ions, versatile carbon/metal composites will be possibly synthesized for catalysis, drug delivery and magnetic uses.

  17. Experimental studies of effect of high current pulse electron and carbon ion beams on high temperature Y-Ba-Cu-O, Bi-Ca-Sr-Cu-O superconductors

    International Nuclear Information System (INIS)

    Korenev, S.A.; Sikolenko, V.V.; Chernakova, A.

    1989-01-01

    This work shows the results of the experiment on the effect of high current electron and carbon ion pulse beams irradiation on High-T c superconductors Y-Ba-Cu-O and Bi-Ca-Cu-O in vacuum (P∼5x10 -5 torr). The parameters of electron beam used in the experiment were: E∼100-300 keV, j e ∼10-1000 A/cm 2 , τ) p ∼300ns. The parameters of carbon ions used in the experiment were: E∼100-300keV j i ∼1-60A/cm, τ p ∼300ns. Experiments had shown the threshold electron beam power density for surface melting in adiabatic heat condition for Y-Ba-Cu-O ceramics up to P 0 >or approx. 10 7 W/cm 2 , and for Bi-Ca-Sr-Cu-O ceramics up to P 0 ∼4x10 6 W/cm 2 . Increasing of critical current in ∼2 times was observed in samples with a melting surface layer. The integral resistance of Y-Ba-Cu-O and Bi-Ca-Sr-Cu-O decreased in ∼2-2.5 times for electron beam irradiated samples and in ∼1.25-1.8 times for ion irradiated samples. Amorphization did not take place and stoichiometry remained after such irradiation. 6 refs.; 2 figs.; 1 tab

  18. Protective Sliding Carbon-Based Nanolayers Prepared by Argon or Nitrogen Ion-Beam Assisted Deposition on Ti6Al4V Alloy

    Directory of Open Access Journals (Sweden)

    Petr Vlcak

    2016-01-01

    Full Text Available The microstructure and the surface properties of samples coated by carbon-based nanolayer were investigated in an effort to increase the surface hardness and reduce the coefficient of friction of the Ti6Al4V alloy. Protective carbon-based nanolayers were fabricated by argon or nitrogen ion-beam assisted deposition at ion energy of 700 eV on Ti6Al4V substrates. The Raman spectra indicated that nanolayers had a diamond-like carbon character with sp2 rich bonds. The TiC and TiN compounds formed in the surface area were detected by X-ray diffraction. Nanoscratch tests showed increased adhesion of a carbon-based nanolayer deposited with ion assistance in comparison with a carbon nanolayer deposited without ion assistance. The results showed that argon ion assistance leads to greater nanohardness than a sample coated by a carbon-based nanolayer with nitrogen ion assistance. A more than twofold increase in nanohardness and a more than fivefold decrease in the coefficient of friction were obtained for samples coated by a carbon-based nanolayer with ion assistance, in comparison with the reference sample.

  19. Comparison of Out-Of-Field Neutron Equivalent Doses in Scanning Carbon and Proton Therapies for Cranial Fields

    DEFF Research Database (Denmark)

    Athar, B.; Henker, K.; Jäkel, O.

    2010-01-01

    Purpose: The purpose of this analysis is to compare the secondary neutron lateral doses from scanning carbon and proton beam therapies. Method and Materials: We simulated secondary neutron doses for out-of-field organs in an 11-year old male patient. Scanned carbon and proton beams were simulated...

  20. Synthesis of carbon-11-labeled imidazopyridine- and purine-thioacetamide derivatives as new potential PET tracers for imaging of nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1).

    Science.gov (United States)

    Gao, Mingzhang; Wang, Min; Zheng, Qi-Huang

    2016-03-01

    The target tracer carbon-11-labeled imidazopyridine- and purine-thioacetamide derivatives, N-(3-[(11)C]methoxy-4-methoxyphenyl)-2-((5-methoxy-3H-imidazo[4,5-b]pyridin-2-yl)thio)acetamide (3-[(11)C]4a) and N-(4-[(11)C]methoxy-3-methoxyphenyl)-2-((5-methoxy-3H-imidazo[4,5-b]pyridin-2-yl)thio)acetamide (4-[(11)C]4a); 2-((6-amino-9H-purin-8-yl)thio)-N-(3-[(11)C]methoxy-4-methoxyphenyl)acetamide (3-[(11)C]8a) and 2-((6-amino-9H-purin-8-yl)thio)-N-(4-[(11)C]methoxy-3-methoxyphenyl)acetamide (4-[(11)C]8a), were prepared by O-[(11)C]methylation of their corresponding precursors with [(11)C]CH3OTf under basic condition (2N NaOH) and isolated by a simplified solid-phase extraction (SPE) method in 50-60% radiochemical yields based on [(11)C]CO2 and decay corrected to end of bombardment (EOB). The overall synthesis time from EOB was 23min, the radiochemical purity was >99%, and the specific activity at end of synthesis (EOS) was 185-555GBq/μmol. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Flexural strength using Steel Plate, Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) on reinforced concrete beam in building technology

    Science.gov (United States)

    Tarigan, Johannes; Patra, Fadel Muhammad; Sitorus, Torang

    2018-03-01

    Reinforced concrete structures are very commonly used in buildings because they are cheaper than the steel structures. But in reality, many concrete structures are damaged, so there are several ways to overcome this problem, by providing reinforcement with Fiber Reinforced Polymer (FRP) and reinforcement with steel plates. Each type of reinforcements has its advantages and disadvantages. In this study, researchers discuss the comparison between flexural strength of reinforced concrete beam using steel plates and Fiber Reinforced Polymer (FRP). In this case, the researchers use Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) as external reinforcements. The dimension of the beams is 15 x 25 cm with the length of 320 cm. Based on the analytical results, the strength of the beam with CFRP is 1.991 times its initial, GFRP is 1.877 times while with the steel plate is 1.646 times. Based on test results, the strength of the beam with CFRP is 1.444 times its initial, GFRP is 1.333 times while the steel plate is 1.167 times. Based on these test results, the authors conclude that beam with CFRP is the best choice for external reinforcement in building technology than the others.

  2. Transfer-free synthesis of graphene-like atomically thin carbon films on SiC by ion beam mixing technique

    Science.gov (United States)

    Zhang, Rui; Chen, Fenghua; Wang, Jinbin; Fu, Dejun

    2018-03-01

    Here we demonstrate the synthesis of graphene directly on SiC substrates at 900 °C using ion beam mixing technique with energetic carbon cluster ions on Ni/SiC structures. The thickness of 7-8 nm Ni films was evaporated on the SiC substrates, followed by C cluster ion bombarding. Carbon cluster ions C4 were bombarded at 16 keV with the dosage of 4 × 1016 atoms/cm2. After thermal annealing process Ni silicides were formed, whereas C atoms either from the decomposition of the SiC substrates or the implanted contributes to the graphene synthesis by segregating and precipitating process. The limited solubility of carbon atoms in silicides, involving SiC, Ni2Si, Ni5Si2, Ni3Si, resulted in diffusion and precipitation of carbon atoms to form graphene on top of Ni and the interface of Ni/SiC. The ion beam mixing technique provides an attractive production method of a transfer-free graphene growth on SiC and be compatible with current device fabrication.

  3. Structural properties and surface wettability of Cu-containing diamond-like carbon films prepared by a hybrid linear ion beam deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Peng; Sun, Lili; Li, Xiaowei [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Xu, Sheng [Gao Hong Coating Technology Co., Ltd, Huzhou 313000 (China); Ke, Peiling [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Aiying, E-mail: aywang@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2015-06-01

    Cu-containing diamond-like carbon (Cu-DLC) films were deposited on Si/glass substrate by a hybrid ion beam deposition system. The Cu concentration (0.1–39.7 at.%) in the film was controlled by varying the sputtering current. The microstructure and composition of Cu-DLC films were investigated systematically. The surface topography, roughness and surface wettability of the films were also studied. Results indicated that with increasing the Cu concentration, the water contact angle of the films changed from 66.8° for pure carbon film to more than 104.4° for Cu-DLC films with Cu concentration larger than 24.4 at.%. In the hydrophilic region, the polar surface energy decreased from 30.54 mJ/m{sup 2} for pure carbon film to 2.48 mJ/m{sup 2} for the film with Cu 7.0 at.%. - Highlights: • Cu-containing diamond-like carbon (DLC) films were deposited by a hybrid ion beam system. • Cu-containing DLC films exhibited a wide range of water contact angle. • The water contact angles vary with the surface energies and surface roughness.

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

    DEFF Research Database (Denmark)

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

    different sets of data obtained for the same cell line and different ions, measured at different laboratories, we have fitted model parameters to a set of carbon-irradiated V79 cells, published by Furusawa et al. (2), and to a set of proton-irradiated V79 cells, published by Wouters et al. (3), separately....... We found that values of model parameters best fitted to the carbon data of Furusawa et al. yielded predictions of V79 survival after proton irradiation which did not match the V79 proton data of Wouters et al. Fitting parameters to both sets combined did not improve the accuracy of model predictions...... carbon irradiation. 1. Katz, R., Track structure in radiobiology and in radiation detection. Nuclear Track Detection 2: 1-28 (1978). 2. Furusawa Y. et al. Inactivation of aerobic and hypoxic cells from three different cell lines by accelerated 3He-, 12C- and 20Ne beams. Radiat Res. 2012 Jan; 177...

  5. Beam generation and planar imaging at energies below 2.40 MeV with carbon and aluminum linear accelerator targets.

    Science.gov (United States)

    Parsons, David; Robar, James L

    2012-07-01

    Recent work has demonstrated improvement of image quality with low-Z linear accelerator targets and energies as low as 3.5 MV. In this paper, the authors lower the incident electron beam energy between 1.90 and 2.35 MeV and assess the improvement of megavoltage planar image quality with the use of carbon and aluminum linear accelerator targets. The bending magnet shunt current was adjusted in a Varian linear accelerator to allow selection of mean electron energy between 1.90 and 2.35 MeV. Linac set points were altered to increase beam current to allow experimental imaging in a practical time frame. Electron energy was determined through comparison of measured and Monte Carlo modeled depth dose curves. Planar image CNR and spatial resolution measurements were performed to quantify the improvement of image quality. Magnitudes of improvement are explained with reference to Monte Carlo generated energy spectra. After modifications to the linac, beam current was increased by a factor greater than four and incident electron energy was determined to have an adjustable range from 1.90 MeV to 2.35 MeV. CNR of cortical bone was increased by a factor ranging from 6.2 to 7.4 and 3.7 to 4.3 for thin and thick phantoms, respectively, compared to a 6 MV therapeutic beam for both aluminum and carbon targets. Spatial resolution was degraded slightly, with a relative change of 3% and 10% at 0.20 lp∕mm and 0.40 lp∕mm, respectively, when reducing energy from 2.35 to 1.90 MV. The percentage of diagnostic x-rays for the beams examined here, ranges from 46% to 54%. It is possible to produce a large fraction of diagnostic energy x-rays by lowering the beam energy below 2.35 MV. By lowering the beam energy to 1.90 MV or 2.35 MV, CNR improves by factors ranging from 3.7 to 7.4 compared to a 6 MV therapy beam, with only a slight degradation of spatial resolution when lowering the energy from 2.35 MV to 1.90 MV.

  6. Simple synthesis of carbon-11-labeled chromen-4-one derivatives as new potential PET agents for imaging of DNA-dependent protein kinase (DNA-PK) in cancer

    International Nuclear Information System (INIS)

    Gao, Mingzhang; Wang, Min; Miller, Kathy D.; Zheng, Qi-Huang

    2012-01-01

    Carbon-11-labeled chromen-4-one derivatives were synthesized as new potential PET agents for imaging of DNA repair enzyme DNA-dependent protein kinase (DNA-PK) in cancer. The target tracers, X-[ 11 C]methoxy-2-morpholino-4H-chromen-4-ones (X=8, 7, 6, 5; [ 11 C]4a–d), were prepared from their corresponding precursors, X-hydroxy-2-morpholino-4H-chromen-4-ones (X=8, 7, 6, 5; 5a–d), with [ 11 C]CH 3 OTf through O-[ 11 C]methylation and isolated by a simplified solid-phase extraction (SPE) method using a C-18 Sep-Pak Plus cartridge. The radiochemical yields decay corrected to end of bombardment (EOB), from [ 11 C]CO 2 , were 40–60%. The specific activity at end of synthesis (EOS) was 185–370 GBq/μmol. - Highlights: ► New chromen-4-one derivatives were synthesized. ► New carbon-11-labeled chromen-4-one derivatives were synthesized. ► Simple solid-phase extraction (SPE) method was employed in radiosynthesis.

  7. Whole-body pharmacokinetics of HDAC inhibitor drugs, butyric acid, valproic acid and 4-phenylbutyric acid measured with carbon-11 labeled analogs by PET

    International Nuclear Information System (INIS)

    Kim, Sung Won; Hooker, Jacob M.; Otto, Nicola; Win, Khaing; Muench, Lisa; Shea, Colleen; Carter, Pauline; King, Payton; Reid, Alicia E.; Volkow, Nora D.; Fowler, Joanna S.

    2013-01-01

    The fatty acids, n-butyric acid (BA), 4-phenylbutyric acid (PBA) and valproic acid (VPA, 2-propylpentanoic acid) have been used for many years in the treatment of a variety of CNS and peripheral organ diseases including cancer. New information that these drugs alter epigenetic processes through their inhibition of histone deacetylases (HDACs) has renewed interest in their biodistribution and pharmacokinetics and the relationship of these properties to their therapeutic and side effect profiles. In order to determine the pharmacokinetics and biodistribution of these drugs in primates, we synthesized their carbon-11 labeled analogues and performed dynamic positron emission tomography (PET) in six female baboons over 90 min. The carbon-11 labeled carboxylic acids were prepared by using 11 CO 2 and the appropriate Grignard reagents. [ 11 C]BA was metabolized rapidly (only 20% of the total carbon-11 in plasma was parent compound at 5 min post injection) whereas for VPA and PBA 98% and 85% of the radioactivity were the unmetabolized compound at 30 min after their administration respectively. The brain uptake of all three carboxylic acids was very low ( VPA > PBA), which is consistent with the need for very high doses for therapeutic efficacy. Most of the radioactivity was excreted through the kidneys and accumulated in the bladder. However, the organ biodistribution between the drugs differed. [ 11 C]BA showed relatively high uptake in spleen and pancreas whereas [ 11 C]PBA showed high uptake in liver and heart. Notably, [ 11 C]VPA showed exceptionally high heart uptake possibly due to its involvement in lipid metabolism. The unique biodistribution of each of these drugs may be of relevance in understanding their therapeutic and side effect profile including their teratogenic effects

  8. The catabolite repressor/activator, Cra, bridges a connection between carbon metabolism and host colonization in the plant drought resistance-promoting bacterium Pantoea alhagi LTYR-11Z.

    Science.gov (United States)

    Zhang, Lei; Li, Muhang; Li, Qiqi; Chen, Chaoqiong; Qu, Meng; Li, Mengyun; Wang, Yao; Shen, Xihui

    2018-04-27

    Efficient root colonization is a prerequisite for application of plant growth promoting (PGP) bacteria in improving health and yield of agricultural crops. We have recently identified an endophytic bacterium Pantoea alhagi LTYR-11Z with multiple PGP properties that effectively colonizes the root system of wheat and improves its growth and drought tolerance. To identify novel regulatory genes required for wheat colonization, we screened a LTYR-11Z transposon (Tn) insertion library and found cra to be a colonization-related gene. By using RNA-seq analysis, we found that transcriptional levels of an eps operon, the ydiV gene encoding an anti-FlhD 4 C 2 factor and the yedQ gene encoding an enzyme for synthesis of cyclic dimeric GMP (c-di-GMP) were significantly downregulated in the mutant Δ cra. Further studies demonstrated that Cra directly binds to the promoters of the eps operon, ydiV and yedQ and activates their expression, thus inhibiting motility and promoting exopolysaccharides (EPS) production and biofilm formation. Consistent with previous findings that Cra plays a role in transcriptional regulation in response to carbon source availability, the activating effects of Cra were much more pronounced when LTYR-11Z was grown within a gluconeogenic environment than when it was grown within a glycolytic environment. We further demonstrate that the ability of LTYR-11Z to colonize wheat roots is modulated by the availability of carbon sources. All together, these results uncover a novel strategy utilized by LTYR-11Z to achieve host colonization in response to carbon nutrition in the environment, in which Cra bridges a connection between carbon metabolism and colonization capacity of LTYR-11Z. IMPORTANCE Rapid and appropriate response to environmental signals is crucial for bacteria to adapt to competitive environments and to establish interactions with their hosts. Efficient colonization and persistence within the host is controlled by various regulatory factors that

  9. Tracers development for the PET study of nicotinic receptors: [{sup 11}C]-mecamylamine and [{sup 11}C]-SIB 1553A. Tritium and carbon-11 radiolabelling of a serine proteinase inhibitor: the t-PA{sub stop}; Developpement de traceurs pour l'etude des recepteurs nicotiniques par TEP: la [{sup 11}C]-mecamylamine et le [{sup 11}C]SIB 1553A. Radiomarquages par le tritium et le carbone-11 d'un inhibiteur d'une serine protease: le t-PA{sub stop}

    Energy Technology Data Exchange (ETDEWEB)

    Sobrio, F.

    2002-12-15

    In order to develop radiotracers for the Positron Emission Tomography (PET), we labelled both the mecamylamine and SIB-1553A with carbon-11 to study the nicotinic cholinergic receptors (nAChRs). The radiosynthesis of [{sup 11}C]-t-PA{sub stop} and the labelling with tritium of one analogue were realized for cerebral ischemia PET studies. The [{sup 11}C]-mecamylamine, a non-competitive and non-selective nAChRs antagonist was synthesized in 45 min via a N-[{sup 11}C]-methylation reaction. In the rat brain, the ex vivo studies showed no radio-metabolite 45 min after the injection of [{sup 11}C]-mecamylamine. The uptake kinetics in the rat brain or in vivo by PET in the anesthetized baboon or in the conscious monkey, reached a plateau around 45-50 min after injection. However, the saturation or displacement experiments did not permit to exhibit nor a significant difference of labelling between the different cerebral regions nor a specific uptake. In consequence, the [{sup 11}C]-mecamylamine was not an appropriate radioligand for nAChRs PET study. The labelling of [{sup 11}C]-SIB 1553A, a selective agonist for the nicotinic {beta}4 subunit, required the synthesis in 5 steps (56% overall yield) of precursor for the incorporation of carbon-11. The radiosynthesis was performed in 36 min by a N-[{sup 11}C]-methylation reaction (yield: 75%). The [{sup 11}C]-t-PA{sub stop} was obtained from [{sup 11}C]-KCN with yields from 80 to 90%. For the first time with carbon-11, the formation of an amidine group was realized from a nitrile group. The labelling by isotopic exchange of hydrogen by tritium of the t-PA{sub stop} did not permit to obtain the [{sup 3}H]-t-PA{sub stop} but a tritiated analogue. This compound will be used to study its vectorization by micro-encapsulation. (author)

  10. Design and Synthesis of 11C-Labelled Compound Libraries for the Molecular Imaging of EGFr, VEGFr-2, AT1 and AT2 Receptors: Transition-Metal Mediated Carbonylations Using [11C]Carbon Monoxide

    International Nuclear Information System (INIS)

    Aaberg, Ola

    2009-01-01

    This work deals with radiochemistry and new approaches to develop novel PET tracers labelled with the radionuclide 11 C. Two methods for the synthesis of 11 C-labelled acrylamides have been explored. First, [1- 11 C]-acrylic acid was obtained from a palladium(0)-mediated 11 C-carboxylation of acetylene with [ 11 C]carbon monoxide; this could be converted to the corresponding acyl chloride and then combined with benzylamine to form N-benzyl[carbonyl- 11 C]acrylamide. In the second method, the palladium(0)-mediated carbonylation of vinyl halides with [ 11 C]carbon monoxide was explored. This latter method, yielded labelled acrylamides in a single step with retention of configuration at the C=C double bond, and required less amine compared to the acetylene method. The vinyl halide method was used to synthesize a library of 11 C-labelled EGFr-inhibitors in 7-61% decay corrected radiochemical yield via a combinatorial approach. The compounds were designed to target either the active or the inactive form of EGFr, following computational docking studies. The rhodium(I)-mediated carbonylative cross-coupling of an azide and an amine was shown to be a very general reaction and was used to synthesize a library of dual VEGFr-2/PDGFrβ inhibitors that were 11 C-labelled at the urea position in 38-78% dc rcy. The angiotensin II AT 1 receptor antagonist eprosartan was 11 C-labelled at one of the carboxyl groups in one step using a palladium(0)-mediated carboxylation. Autoradiography shows specific binding in rat kidney, lung and adrenal cortex, and organ distribution shows a high accumulation in the intestines, kidneys and liver. Specific binding in frozen sections of human adrenal incidentalomas warrants further investigations of this tracer. Three angiotensin II AT 2 ligands were 11 C-labelled at the amide group in a palladium(0)-mediated aminocarbonylation in 16-36% dc rcy. One of the compounds was evaluated using in vitro using autoradiography, and in vivo using organ

  11. Measurement of regional pulmonary function with carbon-11-labeled CO/sub 2/ and CO. Studies of radioactive gas clearance curve

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, K; Rikitake, T; Hasegawa, S [Tsukuba Univ., Sakura, Ibaraki Japan; Matsumoto, T; Tateno, Y

    1979-06-01

    Carbon dioxide and carbon monoxide labelled with carbon-11 have been produced in the remotecontrolled system for a large scale production of short lived radioactive substance with cyclotron in National Institute of Radiological Sciences. The single breath measurement with /sup 11/CO/sub 2/ and /sup 11/CO, using inhalation system and a coincidence positron camera combined with an on-line computer system (TOSBAC 3400 Model 31) has been employed to evaluate regional pulmonary blood flow and diffusing capacity in three normal volunteers and seven patients with chronic obstructive pulmonary disease (COPD), old lung tuberculosis and benign tumor. Regional clearance rate constant (lambda) and distribution index (lambda i/lambda t) were calculated from monoexponential removal curves measured by external counting over the chest in supine position. This process was performed in a short period of breath-holding (10 - 20 sec.) after a single breath of these radioactive gases mixed with room air. These parameters were calculated for each lung fields divided into four zones (bilateral upper and lower lung region). In our method, the activity of the inspired mixture were 5 - 35 mCi/L and each value in lung fields, divided into four zones, can be measured with time interval for one second. While the clearance rate of /sup 11/CO/sub 2/ seemed to be mainly limited by pulmonary blood flow, it was considered that the rate of /sup 11/CO were limited by not only the diffusing capacity but also the perfusion in each lung fields. In normal subjects, the distribution of regional clearance rate was showed approximately even for /sup 11/CO/sub 2/ and /sup 11/CO. It was caused of the measurement in supine position. In contrast, the distribution of these parameter was showed uneven in patients with lung disease, particularly with COPD.

  12. Corrosion resistance of Ultra-Low-Carbon 19% Cr-11% Ni stainless steel for nuclear fuel reprocessing plants in nitric acid

    International Nuclear Information System (INIS)

    Ariga, Tamako; Takagi, Yoshio; Inazumi, Toru; Masamura, Katsumi; Sukekawa, M.

    1995-01-01

    An Ultra-Low-Carbon 19% Cr-11% Ni Stainless Steels used in nuclear fuel reprocessing plants where highly corrosion resistance in nitric acid is required has been developed. This steel has optimized the chemistry composition to decrease inclusions and deformation-induced martensitic transformation. The formation of deformation-induced martensite has the potential danger of accelerating corrosion in nitric acid. In this paper, effects of cold reduction and martensitic transformation on corrosion resistance of Ultra-Low-Carbon Stainless Steels in nitric acid are discussed. The developed steel showed excellent corrosion resistance during long-term exposure to nitric acid. (author)

  13. USGS Arctic Ocean carbon cruise 2011: field activity H-01-11-AR to collect carbon data in the Arctic Ocean, August - September 2011

    Science.gov (United States)

    Robbins, Lisa L.; Yates, Kimberly K.; Knorr, Paul O.; Wynn, Jonathan; Lisle, John; Buczkowski, Brian J.; Moore, Barbara; Mayer, Larry; Armstrong, Andrew; Byrne, Robert H.; Liu, Xuewu

    2013-01-01

    Carbon dioxide (CO2) in the atmosphere is absorbed at the surface of the ocean by reacting with seawater to form a weak, naturally occurring acid called carbonic acid. As atmospheric carbon dioxide increases, the concentration of carbonic acid in seawater also increases, causing a decrease in ocean pH and carbonate mineral saturation states, a process known as ocean acidification. The oceans have absorbed approximately 525 billion tons of carbon dioxide from the atmosphere, or about one-quarter to one-third of the anthropogenic carbon emissions released since the beginning of the Industrial Revolution (Sabine and others, 2004). Global surveys of ocean chemistry have revealed that seawater pH has decreased by about 0.1 units (from a pH of 8.2 to 8.1) since the 1700s due to absorption of carbon dioxide (Caldeira and Wickett, 2003; Orr and others, 2005; Raven and others, 2005). Modeling studies, based on Intergovernmental Panel on Climate Change (IPCC) CO2 emission scenarios, predict that atmospheric carbon dioxide levels could reach more than 500 parts per million (ppm) by the middle of this century and 800 ppm by the year 2100, causing an additional decrease in surface water pH of 0.3 pH units. Ocean acidification is a global threat and is already having profound and deleterious effects on the geology, biology, chemistry, and socioeconomic resources of coastal and marine habitats (Raven and others, 2005; Ruttiman, 2006). The polar and sub-polar seas have been identified as the bellwethers for global ocean acidification.

  14. Synthesis of a sugar-organometallic compound 1,1′-difurfurylferrocene and its microwave preparation of carbon/iron oxide nanocomposite

    International Nuclear Information System (INIS)

    Zhao Shanyu; Cooper, Daniel C.; Xu, Haixun; Zhu Pinghua; Suggs, J. William

    2013-01-01

    Graphical abstract: In order to synthesize a carbon–metal or metal oxide combination sphere, carbonaceous resource furfural was introduced, which was nucleophilic treated with 1,1′-dilithioferrocene to form a sugar-organometallic compound: ferrocenyl monosaccharide derivative 1,1′-difurfurylferrocene, which can be hydrothermally treated in a microwave reactor to give 300–500 nm microspheres with the α-Fe 2 O 3 or Fe 3 O 4 formed on the surface, which may be favorable for new magnetic materials preparation or instead of iron with other metal ions, versatile carbon/metal composites will be possibly synthesized for catalysis, drug delivery and magnetic uses. Highlights: ► We synthesized 1,1′-difurfurylferrocene by nucleophilic treating furfural with 1,1′-dilithioferrocene. ► 1,1′-Difurfurylferrocene can be hydrothermally treated by microwave to give microspheres with iron oxides on the surface. ► 1,1′-Difurfurylferrocene has 2 reactive furanose units, which form carbonspheres and ferrocenyl can give iron oxides. ► REDOX atmosphere influences the coating structures. - Abstract: In order to synthesize a carbon–metal or metal oxide combination sphere, carbonaceous resource furfural 1 was introduced, which was nucleophilic treated with 1,1′-dilithioferrocene 2 to form a sugar-organometallic compound: ferrocenyl monosaccharide derivative 1,1′-difurfurylferrocene 3. 1,1′-Difurfurylferrocene 3 can be hydrothermally treated in a microwave reactor to give 300–500 nm microspheres with the α-Fe 2 O 3 or Fe 3 O 4 nanocrystals formed on the surface, which may be favorable for new magnetic materials preparation or instead of iron with other metal ions, versatile carbon/metal composites will be possibly synthesized for catalysis, drug delivery and magnetic uses.

  15. The potential of carbon-11 and fluorine-18 chemistry: illustration through the development of positron emission tomography radioligands targeting the translocator protein 18 kDa

    International Nuclear Information System (INIS)

    Damont, Annelaure; Roeda, Dirk; Dolle, Frederic

    2013-01-01

    The TSPO (translocator protein), also known as the peripheral benzodiazepine receptor, is up-regulated in the brain of subjects suffering from neuro-degenerative disorders such as Alzheimer's, Parkinson's and Huntington's disease. Moreover, this overexpression has been proved to be linked to micro-glia activation making thus the TSPO a marker of choice of neuro-inflammatory processes and therefore a potential target for the development of radioligands for positron emission tomography imaging. The discovery of selective TSPO ligands and their labelling with the short-lived positron-emitter isotopes carbon-11 and fluorine-18 emerged in the mid-1980's with the preparation of the 3-iso-quinolinecarboxamide [ 11 C]PK11195. To date, an impressive number of promising compounds - [ 11 C]PK11195-challengers - have been developed; some radioligands - for example, [ 11 C]PBR28, [ 11 C]DPA-713, [ 18 F]FEDAA1106 and [ 18 F]DPA-714 - are currently used in clinical trials. As illustrated in this review, the methodologies applied for the preparation of these compounds remain mainly [ 11 C]methylations using [ 11 C]MeI or [ 11 C]MeOTf and SN2- type nucleophilic aliphatic [ 18 F]fluorinations - two processes illustrating the state-of-the-art arsenal of reactions that involves these two short-lived radioisotopes - but alternative processes, such as [ 11 C]carbonylations using [ 11 C]CO and [ 11 C]COCl 2 as well as SNAr-type nucleophilic [ 18 F]fluorinations, have also been reported and as such, reviewed herein. (authors)

  16. Development of digital reconstructed radiography software at new treatment facility for carbon-ion beam scanning of National Institute of Radiological Sciences.

    Science.gov (United States)

    Mori, Shinichiro; Inaniwa, Taku; Kumagai, Motoki; Kuwae, Tsunekazu; Matsuzaki, Yuka; Furukawa, Takuji; Shirai, Toshiyuki; Noda, Koji

    2012-06-01

    To increase the accuracy of carbon ion beam scanning therapy, we have developed a graphical user interface-based digitally-reconstructed radiograph (DRR) software system for use in routine clinical practice at our center. The DRR software is used in particular scenarios in the new treatment facility to achieve the same level of geometrical accuracy at the treatment as at the imaging session. DRR calculation is implemented simply as the summation of CT image voxel values along the X-ray projection ray. Since we implemented graphics processing unit-based computation, the DRR images are calculated with a speed sufficient for the particular clinical practice requirements. Since high spatial resolution flat panel detector (FPD) images should be registered to the reference DRR images in patient setup process in any scenarios, the DRR images also needs higher spatial resolution close to that of FPD images. To overcome the limitation of the CT spatial resolution imposed by the CT voxel size, we applied image processing to improve the calculated DRR spatial resolution. The DRR software introduced here enabled patient positioning with sufficient accuracy for the implementation of carbon-ion beam scanning therapy at our center.

  17. Facile synthesis of new carbon-11 labeled conformationally restricted rivastigmine analogues as potential PET agents for imaging AChE and BChE enzymes

    International Nuclear Information System (INIS)

    Wang Min; Wang Jiquan; Gao Mingzhang; Zheng Qihuang

    2008-01-01

    Rivastigmine is a newer-generation inhibitor with a dual inhibitory action on both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes, and is used for the treatment of AChE- and BChE-related diseases such as brain Alzheimer's disease and cardiovascular disease. New carbon-11 labeled conformationally restricted rivastigmine analogues radiolabeled quaternary ammonium triflate salts, (3aR,9bS)-1-[ 11 C]methyl-1-methyl-6-(methylcarbamoyloxy)-2,3,3a,4,5, 9b-hexahy dro-1H-benzo[g]indolium triflate ([ 11 C]8) and (3aR,9bS)-1-[ 11 C]methyl-1-methyl-6-(heptylcarbamoyloxy)-2,3,3a,4,5, 9b-hexahy dro-1H-benzo[g]indolium triflate ([ 11 C]9), were designed and synthesized as potential positron emission tomography (PET) agents for imaging AChE and BChE enzymes. The appropriate precursors were labeled with [ 11 C]CH 3 OTf through N-[ 11 C]methylation, and the target tracers were isolated by solid-phase extraction (SPE) using a cation-exchange CM Sep-Pak cartridge in 40-50% radiochemical yields decay corrected to end of bombardment (EOB), 15-20 min overall synthesis time, and 148-222 GBq/μmol specific activity at EOB

  18. Nonlinear free vibration analysis of elastically supported carbon nanotube-reinforced composite beam with the thermal environment in non-deterministic framework

    Directory of Open Access Journals (Sweden)

    Chaudhari Virendra Kumar

    2017-01-01

    Full Text Available This paper deals with the investigation of nonlinear free vibration behavior of elastically supported carbon nanotube reinforced composite (CNTRC beam subjected to thermal loading with random system properties. Material properties of each constituent’s material, volume fraction exponent and foundation parameters are considered as uncorrelated Gaussian random input variables. The beam is supported by a Pasternak foundation with Winkler cubic nonlinearity. The higher order shear deformation theory (HSDT with von-Karman non-linearity is used to formulate the governing equation using Hamilton principle. Convergence and validation study is carried out through the comparison with the available results in the literature for authenticity and accuracy of the present approach used in the analysis. First order perturbation technique (FOPT,Second order perturbation technique (SOPT and Monte Carlo simulation (MCS methods are employed to investigate the effect of geometric configuration, volume fraction exponent, foundation parameters, distribution of reinforcement and thermal loading on nonlinear vibration characteristics CNTRC beam.The present work signifies the accurate analysis of vibrational behaviour influences by different random variables. Results are presented in terms of mean, variance (COV and probability density function (PDF for various aforementioned parameters.

  19. Operation of medical accelerator PATRO at Hyogo Ion Beam Medical Center

    International Nuclear Information System (INIS)

    Itano, A.; Akagi, T.; Higashi, A.; Fukushima, S.; Fujita, A.; Honda, Y.; Isa, H.; Nishikigouri, K.

    2004-01-01

    PATRO (Particle Accelerator for Therapy, Radiology and Oncology) is a medical accelerator facility for hadrontherapy of cancer at Hyogo Ion Beam Medical Center (HIBMC). Beam particles are proton (230 MeV) and carbon (320 MeV/u). After the beam commissioning and the tuning of irradiation system in 2000, we performed the clinical trials with proton and carbon beams from May 2001 until July 2002. We operated the accelerator for about 11,000 hours since the beginning of the beam tuning until the end of the clinical trials and for about 5,000 hours during the clinical trials. No serious troubles happened during the clinical trials. The stability and the reproducibility of the beams were well proved. (author)

  20. Carbon Nanodots: Dual‐Color‐Emitting Carbon Nanodots for Multicolor Bioimaging and Optogenetic Control of Ion Channels (Adv. Sci. 11/2017)

    OpenAIRE

    Kim, Hyemin; Park, Yoonsang; Beack, Songeun; Han, Seulgi; Jung, Dooyup; Cha, Hyung Joon; Kwon, Woosung; Hahn, Sei Kwang

    2017-01-01

    Carbon nanodots (CNDs) have been widely investigated for theranostic applications including fluorescence imaging, photoacoustic imaging, photothermal therapy, and photodynamic therapy. In article number 1700325, Sei Kwang Hahn, Woosung Kwon, and co‐workers develop dual‐color‐emitting CNDs uniquely designed by the electronic structure engineering for both futuristic multi‐color bioimaging and optogenetic control of ion channels.

  1. Three-dimensional thermal simulations of thin solid carbon foils for charge stripping of high current uranium ion beams at a proposed new heavy-ion linac at GSI

    Directory of Open Access Journals (Sweden)

    N. A. Tahir

    2014-04-01

    Full Text Available This paper presents an extensive numerical study of heating of thin solid carbon foils by 1.4  MeV/u uranium ion beams to explore the possibility of using such a target as a charge stripper at the proposed new Gesellschaft für Schwerionenforschung high energy heavy–ion linac. These simulations have been carried out using a sophisticated 3D computer code that accounts for physical phenomena that are important in this problem. A variety of beam and target parameters have been considered. The results suggest that within the considered parameter range, the target will be severely damaged by the beam. Thus, a carbon foil stripper does not seem to be a reliable option for the future Gesellschaft für Schwerionenforschung high energy heavy–ion linac, in particular, at FAIR design beam intensities.

  2. Mechanical and thermal measurements on a 11 m long beam screen in the LHC Magnet Test String during RUN 3A

    CERN Document Server

    Artoos, K; Kos, N

    1999-01-01

    Two eleven meter long beam screens were installed in the third dipole of the LHC Magnet Test String. Instrumentation was used to measure the mechanical and thermal behaviour of the screens during thermal transients and quenches. The horizontal deformation, angular displacement, heating of the screen as a result of the quench induced eddy currents and relative longitudinal displacement between beam screen and magnet end were measured.

  3. Modelling, Design, Growth and Characterization of Strain Balanced Quantum Cascade Lasers (3-11mum), grown by Gas Source Molecular Beam Epitaxy

    Science.gov (United States)

    Bandyopadhyay, Neelanjan

    Quantum Cascade Laser (QCL) is a compact room temperature (RT) source of mid-infrared radiation, which can be used for spectroscopic detection of trace amount of chemicals. The mid-infrared spectral range between (3-11 microm), has a dense array of absorption lines of numerous molecules, due to the presence of fundamental vibrational modes. The goal of this thesis can be subdivided into two parts. Firstly, short wavelength QCLs, emitting below 4microm, perform poorly at RT, due to inter-valley Gamma --- L carrier scattering, carrier escape to the continuum, heat removal from the core region at high power density corresponding to short wavelength operation, and large interface scattering due to highly strained materials. Secondly, it is desirable to have a single QCL based source emitting between 6-10microm, which be used to detect multiple molecules having their peak absorptions far apart, inside this spectral range. However, gain bandwidth of a single core QCL is relatively small, so laser emission cannot be tuned over a wide spectral range. This thesis describes the working principle of a QCL based on superlattice transport, rate equations, scattering mechanism, and waveguide design. The choice of the material system for this work and the fundamentals of band structure engineering has been derived. Gas source molecular beam epitaxy - growth optimization and characterization is one of the most important features of this work, especially for short wavelength QCLs, and has been explained in depth. Different strategies for design of active region design of short wavelength QCL and heterogeneous broadband QCL has been explored. The major milestones, of this research was the world's first watt level continuous wave (CW), RT demonstration at 3.76 microm, which was followed by another milestone of the first CW, RT demonstration at 3.39microm and 3.55microm, and finally the elusive result of QCL emitting at CW, RT at a wavelength as short as lambda ~3microm, a record. In

  4. Titanium carbide-carbon porous nanocomposite materials for radioactive ion beam production: processing, sintering and isotope release properties

    CERN Document Server

    AUTHOR|(CDS)2081922; Stora, Thierry

    2017-01-26

    The Isotope Separator OnLine (ISOL) technique is used at the ISOLDE - Isotope Separator OnLine DEvice facility at CERN, to produce radioactive ion beams for physics research. At CERN protons are accelerated to 1.4 GeV and made to collide with one of two targets located at ISOLDE facility. When the protons collide with the target material, nuclear reactions produce isotopes which are thermalized in the bulk of the target material grains. During irradiation the target is kept at high temperatures (up to 2300 °C) to promote diffusion and effusion of the produced isotopes into an ion source, to produce a radioactive ion beam. Ti-foils targets are currently used at ISOLDE to deliver beams of K, Ca and Sc, however they are operated at temperatures close to their melting point which brings target degradation, through sintering and/or melting which reduces the beam intensities over time. For the past 10 years, nanostructured target materials have been developed and have shown improved release rates of the produced i...

  5. Noninvasive determination of myocardial blood flow, oxygen consumption and efficiency in normal humans by carbon-11 acetate positron emission tomography imaging

    International Nuclear Information System (INIS)

    Porenta, G.; Cherry, S.; Czernin, J.; Brunken, R.; Kuhle, W.; Hashimoto, T.; Schelbert, H.R.

    1999-01-01

    The aims of this study were: (1) to measure noninvasively and near simultaneously myocardial blood flow, oxygen consumption, and contractile function and (2) to analyze myocardial energy expenditure and efficiency at rest and during dobutamine stress in normal humans. Dynamic and gated carbon-11 acetate positron emission tomography (PET) imaging was performed in 11 normal subjects. The initial uptake of 11 C-acetate was measured to estimate myocardial blood flow. Oxygen consumption was derived from the monoexponential slope of the 11 C-clearance curve recorded during myocardial washout. ECG-gated systolic and diastolic images were acquired during the peak myocardial 11 C activity to measure left ventricular radius, myocardial wall thickness, and long axis length. Myocardial oxygen consumption and parameters of cardiac geometry were used to determine myocardial energetics and cardiac efficiency by tension-area area analysis. Myocardial blood flow averaged 0.8±0.06 ml min -1 g -1 at rest and 1.48±0.15 ml min -1 g -1 during dobutamine stress. Oxygen delivery and consumption were 151±13 and 88±15 μl O 2 min -1 g -1 at rest and increased to 291±31 and 216±31 μl O 2 min -1 g -1 , respectively, during pharmacological stress (P 11 C acetate imaging provides the unique capability to study noninvasively determinants of myocardial energy delivery, expenditure, and efficiency. (orig.)

  6. Carbon-11 labeled papaverine as a PET tracer for imaging PDE10A: radiosynthesis, in vitro and in vivo evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Tu Zhude [Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)], E-mail: tuz@mir.wustl.edu; Xu Jinbin; Jones, Lynne A.; Li Shihong; Mach, Robert H. [Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)

    2010-05-15

    Papaverine, 1-(3,4-dimethoxybenzyl)-6,7-dimethoxyisoquinoline, a specific inhibitor of phosphodiesterase (PDE) 10A with IC{sub 50} values of 36 nM for PDE10A, 1,300 nM for PDE3A and 320 nM for PDE4D, has served as a useful pharmaceutical tool to study the physiological role of PDE10A. Here, we report the radiosynthesis of [{sup 11}C]papaverine and the in vitro and in vivo evaluation of [{sup 11}C]papaverine as a potential positron emission tomography (PET) radiotracer for imaging PDE10A in the central nervous system (CNS). The radiosynthesis of papaverine with {sup 11}C was achieved by O-methylation of the corresponding des-methyl precursor with [{sup 11}C]methyl iodide. [{sup 11}C]papaverine was obtained with {approx}70% radiochemical yield and a specific activity >10 Ci/{mu}mol. In vitro autoradiography studies of rat and monkey brain sections revealed selective binding of [{sup 11}C]papaverine to PDE10A enriched regions: the striatum of rat brain and the caudate and putamen of rhesus monkey brain. The biodistribution of [{sup 11}C]papaverine in rats at 5 min demonstrated an initially higher accumulation in striatum than in other brain regions, however the washout was rapid. MicroPET imaging studies in rhesus macaques similarly displayed initial specific uptake in the striatum with very rapid clearance of [{sup 11}C]papaverine from brain. Our initial evaluation suggests that despite papaverine's utility for in vitro studies and as a pharmaceutical tool, [{sup 11}C]papaverine is not an ideal radioligand for clinical imaging of PDE10A in the CNS. Analogs of papaverine having a higher potency for inhibiting PDE10A and improved pharmacokinetic properties will be necessary for imaging this enzyme with PET.

  7. Carbon-11 labeled stilbene derivatives from natural products for the imaging of Aβ plaques in the brain

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mengchao; Tang, Ruikun; Li, Zijing; Jia, Hongmei; Liu, Boli [Beijing Normal Univ. (China). Key Laboratory of Radiopharmaceuticals; Zhang, Jinming; Zhang, Xiaojun [Chinese PLA General Hospital, Beijing (China). Dept. of Nuclear Medicine

    2014-04-01

    Four stilbene derivatives from natural products were screened as novel β-amyloid (Aβ) imaging ligands. In vitro binding assay showed that the methylated ligand, (E)-1-methoxy-4-styrylbenzene (8) displayed high binding affinity to Aβ{sub 1-42} aggregates (K{sub i} = 19.5 nM). Moreover, the {sup 11}C-labeled ligand, [{sup 11}C]8 was prepared through an O-methylation reaction using [{sup 11}C]CH{sub 3}OTf. In vitro autoradiography with sections of transgenic mouse brain also confirmed the high and specific binding of [{sup 11}C]8 to Aβ plaques. In vivo biodistribution experiments in normal mice indicated that [{sup 11}C]8 displayed high initial uptake (9.41 ± 0.51% ID/g at 5 min post-injection) into and rapid washout from the brain, with a brain{sub 5} {sub min}/brain{sub 30} {sub min} ratio of 6.63. These preliminary results suggest that [{sup 11}C]8 may be served as a novel Aβ imaging probe for PET. (orig.)

  8. Design and Analysis Methodologies for Inflated Beams

    NARCIS (Netherlands)

    Veldman, S.L.

    2005-01-01

    The central theme of the thesis is bending behaviour of inflated beams. Three different types of beams have been analysed for the bending load case: a straight cylindrical beam made of anisotropic foil material, a conical beam made of an isotropic foil material, and a carbon fibre braided beam. The

  9. Examination of the metastable and stable pitting corrosion of aluminum modified with carbon by ion beam techniques

    International Nuclear Information System (INIS)

    Lensch, O.; Enders, B.; Knecht, J.; Ensinger, W.

    2001-01-01

    It is well known that aluminum and aluminum alloys are sensitive to pitting corrosion when exposed to aqueous solutions containing aggressive anions like halides. The destructive nature of pitting is due to its high local dissolution rates at electrode potentials above the so-called pitting potential U p . Recently, it has been realized that also at potentials below U p , in the passive and cathodic regions and around the free corrosion potential, anodic current transients appear which have been attributed to metastable pitting events. For the purpose of full characterization of the pitting behavior, a program routine has been developed where the occurrence frequency, lifetime and rate of metastable pitting events are extracted from potentiostatic current/time-measurements depending on the electrode potential. The routine has been applied to measurements of carbon modified pure aluminum. Carbon modifications were done with carbon evaporation and carbon sputtering under concurrent argon ion bombardment. The results are discussed in terms of the applied modification technique, their parameters and their effects on the corrosion protection ability of aluminum modified by carbon

  10. Quantum beams

    International Nuclear Information System (INIS)

    Uesaka, Mitsuru

    2003-01-01

    Present state and future prospect are described on quantum beams for medical use. Efforts for compactness of linac for advanced cancer therapy have brought about the production of machines like Accuray's CyberKnife and TOMOTHERAPY (Tomo Therapy Inc.) where the acceleration frequency of X-band (9-11 GHz) is used. For cervical vein angiography by the X-band linac, a compact hard X-ray source is developed which is based on the (reverse) Compton scattering through laser-electron collision. More intense beam and laser are necessary at present. A compact machine generating the particle beam of 10 MeV-1 GeV (laser-plasma accelerator) for cancer therapy is also developed using the recent compression technique (chirped-pulse amplification) to generate laser of >10 TW. Tokyo University is studying for the electron beam with energy of GeV order, for the laser-based synchrotron X-ray, and for imaging by the short pulse ion beam. Development of advanced compact accelerators is globally attempted. In Japan, a virtual laboratory by National Institute of Radiological Sciences (NIRS), a working group of universities and research facilities through the Ministry of Education, Culture, Sports, Science and Technology, started in 2001 for practical manufacturing of the above-mentioned machines for cancer therapy and for angiography. Virtual Factory (Inc.), a business venture, is to be stood in future. (N.I.)

  11. Characterization of carbon, nitrogen, oxygen and refractory metals in binary and ternary silicon-based films using ion beam methods

    International Nuclear Information System (INIS)

    Somatri-Bouamrane, R.

    1996-01-01

    Ion beam methods (non Rutherford backscattering, nuclear reactions) have been carried out in order to characterize silicon-based films. The cross sections for the reactions 12 C(α,α), 14 N(α,α), 16 O(α,α), 28 Si(α,α) and 14 N(α,p) have been measured within 2 and 7 MeV. CVD beta SiC films could be analyzed and the interface between silicon carbide and the (100) silicon substrate was studied. The epitaxial growth of the beta SiC film could be modelled by comparing the results obtained with ion beam analysis, infrared spectroscopy and electron microscopy. Moreover, the stoichiometry of low pressure CVD Me-Si-N (Me=Re, W, Ti, Ta) ternary systems was studied. The evolution of the nitrogen content in W-Si-N systems allowed to study their stability with respect to the annealing conditions. (N.T.)

  12. Electron beam diagnostics study

    International Nuclear Information System (INIS)

    Garganne, P.

    1989-08-01

    This paper summarizes the results of a study on beam diagnostics, using carbon wire scanners and optical transition radiation (DTR) monitors. The main consideration consists in the material selection, taking their thermal properties and their effect on the beam into account [fr

  13. Thickness-modulated tungsten-carbon superconducting nanostructures grown by focused ion beam induced deposition for vortex pinning up to high magnetic fields.

    Science.gov (United States)

    Serrano, Ismael García; Sesé, Javier; Guillamón, Isabel; Suderow, Hermann; Vieira, Sebastián; Ibarra, Manuel Ricardo; De Teresa, José María

    2016-01-01

    We report efficient vortex pinning in thickness-modulated tungsten-carbon-based (W-C) nanostructures grown by focused ion beam induced deposition (FIBID). By using FIBID, W-C superconducting films have been created with thickness modulation properties exhibiting periodicity from 60 to 140 nm, leading to a strong pinning potential for the vortex lattice. This produces local minima in the resistivity up to high magnetic fields (2.2 T) in a broad temperature range due to commensurability effects between the pinning potential and the vortex lattice. The results show that the combination of single-step FIBID fabrication of superconducting nanostructures with built-in artificial pinning landscapes and the small intrinsic random pinning potential of this material produces strong periodic pinning potentials, maximizing the opportunities for the investigation of fundamental aspects in vortex science under changing external stimuli (e.g., temperature, magnetic field, electrical current).

  14. Thick-target neutron, gamma-ray, and radionuclide production for protons below 12 MeV on nickel and carbon beam-stops

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.; Wilson, W.B.

    1998-03-01

    Nuclear model calculations using the GNASH code are described for protons below 12 MeV incident on nickel and carbon isotopes, for beam stop design in the Los Alamos Accelerator Production of Tritium Low Energy Demonstration Accelerator (LEDA) project. The GNASH calculations apply Hauser-Feshbach and preequilibrium reaction theories and can make use of pre-calculated direct reaction cross sections to low-lying residual nucleus states. From calculated thin target cross sections, thick target 6.7 MeV and 12 MeV proton-induced production of neutrons, gamma rays, and radionuclides are determined. Emission spectra of the secondary neutrons and gamma rays are also determined. The model calculations are validated through comparisons with experimental thin- and thick-target measurements. The results of this work are being utilized as source terms in MCNP analyses for LEDA

  15. Comparison of specular H-atomic-beam intensity and C+ secondary-ion yield at thermally activated decrease of a carbon layer on a Ni(110) surface

    International Nuclear Information System (INIS)

    Kaarmann, H.; Hoinkes, H.; Wilsch, H.

    1983-01-01

    The thermally activated disappearance of a carbon layer on a Ni(110) surface was investigated by the scattering of atomic hydrogen and by secondary-ion mass spectrometry. Decreasing C coverage at surface temperatures kept constant in each case at values between 650 and 750 K resulted in an exponential decrease of specular H-beam intensity as well as C + secondary-ion yield. This decrease in both cases fits first-order kinetics (presumable diffusion into the bulk) with an identical rate constant as a function of surface temperature and results finally in a preexponential frequency ν = 10/sup() 10plus-or-minus1/ s -1 and an activation energy E/sub A/ = 1.8 +- 0.2 eV

  16. Effects of carbon and hafnium concentrations in wrought powder-metallurgy superalloys based on nasa 2b-11 alloy

    International Nuclear Information System (INIS)

    Miner, R.V. Jr.

    1976-01-01

    A candidate alloy for advanced-temperature turbine engine disks and four modifications of that alloy with various C and Hf concentrations were produced as cross-rolled disks from prealloyed powder that was hot isostatically compacted. The mechanical properties, microstructures, and phase relations of the alloys are discussed in terms of their C and Hf concentrations. A low-C and high-Hf modification of IIB-11 had the best balance of mechanical properties for service below about 750 C. Because of their finer grain sizes, none of the powder-metallurgy alloys produced had the high-temperature rupture strength of conventionally cast and wrought IIB-11. (Author)

  17. The second advanced ICFA [International Committee for Future Accelerators] beam dynamics workshop, Lugano, Switzerland, April 11-16, 1988: Foreign trip report

    International Nuclear Information System (INIS)

    Ohnuma, Shoroku.

    1988-01-01

    This paper summarizes the trip made by Shoroku Ohnuma to the Second Advanced ICFA Beam Dynamics Workshop in Switzerland. Discussed are the experimental and theoretical studies conducted on aperture- related limitations of storage ring performance. Lepton and hadron storage ring machines are mainly mentioned

  18. The differential role of human macrophage in triggering secondary bystander effects after either gamma-ray or carbon beam irradiation.

    Science.gov (United States)

    Dong, Chen; He, Mingyuan; Tu, Wenzhi; Konishi, Teruaki; Liu, Weili; Xie, Yuexia; Dang, Bingrong; Li, Wenjian; Uchihori, Yukio; Hei, Tom K; Shao, Chunlin

    2015-07-10

    The abscopal effect could be an underlying factor in evaluating prognosis of radiotherapy. This study established an in vitro system to examine whether tumor-generated bystander signals could be transmitted by macrophages to further trigger secondary cellular responses after different irradiations, where human lung cancer NCI-H446 cells were irradiated with either γ-rays or carbon ions and co-cultured with human macrophage U937 cells, then these U937 cells were used as a bystander signal transmitter and co-cultured with human bronchial epithelial cells BEAS-2B. Results showed that U937 cells were only activated by γ-irradiated NCI-H446 cells so that the secondary injuries in BEAS-2B cells under carbon ion irradiation were weaker than γ-rays. Both TNF-α and IL-1α were involved in the γ-irradiation induced secondary bystander effect but only TNF-α contributed to the carbon ion induced response. Further assay disclosed that IL-1α but not TNF-α was largely responsible for the activation of macrophages and the formation of micronucleus in BEAS-2B cells. These data suggest that macrophages could transfer secondary bystander signals and play a key role in the secondary bystander effect of photon irradiation, while carbon ion irradiation has conspicuous advantage due to its reduced secondary injury. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Production of an accelerated oxygen-14 beam

    International Nuclear Information System (INIS)

    Powell, J.; O'Neil, J.P.; Cerny, Joseph

    2003-01-01

    BEARS is an ongoing project to provide a light-ion radioactive-beam capability at the 88-Inch Cyclotron at LBNL. Light radioactive isotopes are produced at a 10 MeV proton medical cyclotron, transported 350 m via a high-speed gas transport capillary, cryogenically separated, and injected into the 88-Inch Cyclotron's ion source. The first radioactive beam successfully accelerated was carbon-11 and beams of intensity more than 10 8 ions/s have been utilized for experiments. Development of oxygen-14 as the second BEARS beam presented considerable technical challenges, both due to its short half-life of 71 s and the radiation chemistry of oxygen in the target. The usual techniques developed for medical uses of oxygen-15 involve the addition of significant amounts of carrier oxygen, something that would overload the ion source. As a solution, oxygen-14 is produced as water in a carrier-free form, and is chemically converted in two steps to carbon dioxide, a form readily usable by the BEARS. This system has been built and is operational, and initial tests of accelerating an oxygen-14 beam have been performed

  20. Measurement of neutron spectra generated by a 62 AMeV carbon-ion beam on a PMMA phantom using extended range Bonner sphere spectrometers

    International Nuclear Information System (INIS)

    Bedogni, R.; Amgarou, K.; Domingo, C.; Russo, S.; Cirrone, G.A.P.; Pelliccioni, M.; Esposito, A.; Pola, A.; Introini, M.V.; Gentile, A.

    2012-01-01

    Neutrons constitute an important component of the radiation environment in hadron therapy accelerators. Their energy distribution may span from thermal up to hundred of MeV. The characterization of these fields in terms of dosimetric or spectrometric quantities is crucial for either the patient protection or the facility design aspects. To date, the Extended Range Bonner Sphere Spectrometer (ERBSS) is the only instrument able to simultaneously determine all spectral components in such workplaces. With the aim of providing useful data to the scientific community involved in neutron measurements at hadron therapy facilities, a measurement campaign was carried out at the Centro di AdroTerapia e Applicazioni Nucleari Avanzate (CATANA) of INFN-LNS (Laboratori Nazionali del Sud), where a 62 AMeV carbon ion is available. The beam was directed towards a PMMA phantom, simulating the patient, and two neutron measurement points were established at 0° and 90° with respect to the beam-line. The ERBSSs of UAB (Universidad Autónoma de Barcelona-Grup de Física de les Radiacions) and INFN (Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati) were used to measure the resulting neutron fields. The two ERBSSs use different detectors and sphere diameters, and have been independently calibrated. The FRUIT code was used to unfold the results.

  1. Measurement of neutron spectra generated by a 62 AMeV carbon-ion beam on a PMMA phantom using extended range Bonner sphere spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Bedogni, R., E-mail: roberto.bedogni@lnf.infn.it [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy); Amgarou, K.; Domingo, C. [Grup de Recerca en Radiacions Ionitzants, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Russo, S.; Cirrone, G.A.P. [Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali dei Sud, Via S. Sofia 62, 95125 Catania (Italy); Pelliccioni, M.; Esposito, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy); Pola, A.; Introini, M.V. [Politecnico di Milano, CESNEF, Dipartimento di Energia, via Ponzio 34/3, 20133 Milano (Italy); Gentile, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy)

    2012-07-21

    Neutrons constitute an important component of the radiation environment in hadron therapy accelerators. Their energy distribution may span from thermal up to hundred of MeV. The characterization of these fields in terms of dosimetric or spectrometric quantities is crucial for either the patient protection or the facility design aspects. To date, the Extended Range Bonner Sphere Spectrometer (ERBSS) is the only instrument able to simultaneously determine all spectral components in such workplaces. With the aim of providing useful data to the scientific community involved in neutron measurements at hadron therapy facilities, a measurement campaign was carried out at the Centro di AdroTerapia e Applicazioni Nucleari Avanzate (CATANA) of INFN-LNS (Laboratori Nazionali del Sud), where a 62 AMeV carbon ion is available. The beam was directed towards a PMMA phantom, simulating the patient, and two neutron measurement points were established at 0 Degree-Sign and 90 Degree-Sign with respect to the beam-line. The ERBSSs of UAB (Universidad Autonoma de Barcelona-Grup de Fisica de les Radiacions) and INFN (Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati) were used to measure the resulting neutron fields. The two ERBSSs use different detectors and sphere diameters, and have been independently calibrated. The FRUIT code was used to unfold the results.

  2. Measurement of neutron spectra generated by a 62 AMeV carbon-ion beam on a PMMA phantom using extended range Bonner sphere spectrometers

    Science.gov (United States)

    Bedogni, R.; Amgarou, K.; Domingo, C.; Russo, S.; Cirrone, G. A. P.; Pelliccioni, M.; Esposito, A.; Pola, A.; Introini, M. V.; Gentile, A.

    2012-07-01

    Neutrons constitute an important component of the radiation environment in hadron therapy accelerators. Their energy distribution may span from thermal up to hundred of MeV. The characterization of these fields in terms of dosimetric or spectrometric quantities is crucial for either the patient protection or the facility design aspects. To date, the Extended Range Bonner Sphere Spectrometer (ERBSS) is the only instrument able to simultaneously determine all spectral components in such workplaces. With the aim of providing useful data to the scientific community involved in neutron measurements at hadron therapy facilities, a measurement campaign was carried out at the Centro di AdroTerapia e Applicazioni Nucleari Avanzate (CATANA) of INFN-LNS (Laboratori Nazionali del Sud), where a 62 AMeV carbon ion is available. The beam was directed towards a PMMA phantom, simulating the patient, and two neutron measurement points were established at 0° and 90° with respect to the beam-line. The ERBSSs of UAB (Universidad Autónoma de Barcelona-Grup de Física de les Radiacions) and INFN (Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati) were used to measure the resulting neutron fields. The two ERBSSs use different detectors and sphere diameters, and have been independently calibrated. The FRUIT code was used to unfold the results.

  3. Thermo-mechanical vibration analysis of a single-walled carbon nanotube embedded in an elastic medium based on higher-order shear deformation beam theory

    International Nuclear Information System (INIS)

    Ebrahimi, Farzad; Salari, Erfan

    2015-01-01

    In this study, the thermal effect on the free vibration characteristics of embedded Single-walled carbon nanotubes (SWCNTs) based on the size-dependent Reddy higher order shear deformation beam theory subjected to in-plane thermal loading is investigated by presenting a Navier-type solution and employing a semi-analytical Differential transform method (DTM) for the first time. In addition, the exact nonlocal Reddy beam theory solution presented here should be useful to engineers designing nanoelectromechanical devices. The small scale effect is considered based on nonlocal elasticity theory of Eringen. The nonlocal equations of motion are derived through Hamilton's principle, and they are solved by applying DTM. Numerical results reveal that the proposed modeling and semi-analytical approach can provide more accurate frequency results of the SWCNTs compared to analytical results and some cases in the literature. The detailed mathematical derivations are presented, and numerical investigations are performed, whereas emphasis is placed on investigating the effect of several parameters such as small-scale effects, boundary conditions, mode number, thickness ratio, temperature change, and Winkler spring modulus on the natural frequencies of the SWCNTs in detail. The vibration behavior of SWCNTs is significantly influenced by these effects. Results indicate that the inclusion of size effect results in a decrease in nanobeam stiffness and leads to a decrease in natural frequency. Numerical results are presented to serve as benchmarks for future analyses of SWCNTs.

  4. Synthesis and preclinical evaluation of carbon-11 labelled N-((5-(4-fluoro-2-[11C]methoxyphenyl)pyridin-3-yl)methyl)cyclopentanamine as a PET tracer for NR2B subunit-containing NMDA receptors

    International Nuclear Information System (INIS)

    Christiaans, Johannes A.M.; Klein, Pieter J.; Metaxas, Athanasios; Kooijman, Esther J.M.; Schuit, Robert C.; Leysen, Josée E.; Lammertsma, Adriaan A.; Berckel, Bart N.M. van; Windhorst, Albert D.

    2014-01-01

    Introduction: The N-methyl-D-Aspartate (NMDA) receptor plays an important role in learning and memory. Overactivation is thought to play an important role in neurodegenerative disorders such as Alzheimer's disease. Currently, it is not possible to assess N-methyl-D-aspartate receptor (NMDAr) bio-availability in vivo. The purpose of this study was to develop a positron emission tomography (PET) ligand for the NR2B binding site of the NMDA receptor. Methods: N-((5-(4-fluoro-2-methoxyphenyl)pyridin-3-yl)methyl)cyclopentanamine was radiolabelled with carbon-11 in the phenyl moiety. Biodistribution and blocking studies were carried out in anaesthetized mice and in non-anaesthetized rats. Results: N-((5-(4-fluoro-2-[ 11 C]methoxyphenyl)pyridin-3-yl)methyl)cyclopentanamine was prepared in 49 ± 3% (decay-corrected) yield, affording 4.1 ± 0.3 GBq of formulated product at the end of synthesis with a radiochemical purity of > 99% and with a specific activity of 78 ± 10 GBq/μmol. Conclusion: A new NR2B PET ligand was developed in high yield. [ 11 C]4 readily enters the brain and binds to the NR2B subunit-containing NMDAr in the rodent brain. High sigma-1 receptor binding may, however, limit its future application as a PET probe for imaging the NR2B subunit-containing NMDAr. Anaesthesia has an effect on NMDAr function and therefore can complicate interpretation of preclinical in vivo results. In addition, effects of endogenous compounds cannot be excluded. Despite these potential limitations, further studies are warranted to investigate the values of [ 11 C]4 as an NR2B PET ligand

  5. Carbon-Based Fe3O4 Nanocomposites Derived from Waste Pomelo Peels for Magnetic Solid-Phase Extraction of 11 Triazole Fungicides in Fruit Samples

    Science.gov (United States)

    Ren, Keyu; Zhang, Wenlin; Cao, Shurui; Wang, Guomin; Zhou, Zhiqin

    2018-01-01

    Carbon-based Fe3O4 nanocomposites (C/Fe3O4 NCs) were synthesized by a simple one-step hydrothermal method using waste pomelo peels as the carbon precursors. The characterization results showed that they had good structures and physicochemical properties. The prepared C/Fe3O4 NCs could be applied as excellent and recyclable adsorbents for magnetic solid phase extraction (MSPE) of 11 triazole fungicides in fruit samples. In the MSPE procedure, several parameters including the amount of adsorbents, extraction time, the type and volume of desorption solvent, and desorption time were optimized in detail. Under the optimized conditions, the good linearity (R2 > 0.9916), the limits of detection (LOD), and quantification (LOQ) were obtained in the range of 1–100, 0.12–0.55, and 0.39–1.85 μg/kg for 11 pesticides, respectively. Lastly, the proposed MSPE method was successfully applied to analyze triazole fungicides in real apple, pear, orange, peach, and banana samples with recoveries in the range of 82.1% to 109.9% and relative standard deviations (RSDs) below 8.4%. Therefore, the C/Fe3O4 NCs based MSPE method has a great potential for isolating and pre-concentrating trace levels of triazole fungicides in fruits. PMID:29734765

  6. Synthesis and biological evaluation of carbon-11- and fluorine-18-labeled 2-oxoquinoline derivatives for type 2 cannabinoid receptor positron emission tomography imaging

    International Nuclear Information System (INIS)

    Evens, Nele; Muccioli, Giulio G.; Houbrechts, Nele; Lambert, Didier M.; Verbruggen, Alfons M.; Van Laere, Koen; Bormans, Guy M.

    2009-01-01

    Introduction: The type 2 cannabinoid (CB 2 ) receptor is part of the endocannabinoid system and has been suggested as a mediator of several central and peripheral inflammatory processes. Imaging of the CB 2 receptor has been unsuccessful so far. We synthesized and evaluated a carbon-11- and a fluorine-18-labeled 2-oxoquinoline derivative as new PET tracers with high specificity and affinity for the CB 2 receptor. Methods: Two 2-oxoquinoline derivatives were synthesized and radiolabeled with either carbon-11 or fluorine-18. Their affinity and selectivity for the human CB 2 receptor were determined. Biological evaluation was done by biodistribution, radiometabolite and autoradiography studies in mice. Results: In vitro studies showed that both compounds are high affinity CB 2 -specific inverse agonists. Biodistribution study of the tracers in mice showed a high in vivo initial brain uptake and fast brain washout, in accordance with the low CB 2 receptor expression levels in normal brain. A persistently high in vivo binding to the spleen was observed, which was inhibited by pretreatment with two structurally unrelated CB 2 selective inverse agonists. In vitro autoradiography studies with the radioligands confirmed CB 2 -specific binding to the mouse spleen. Conclusion: We synthesized two novel CB 2 receptor PET tracers that show high affinity/selectivity for CB 2 receptors. Both tracers show favourable characteristics as radioligands for central and peripheral in vivo visualization of the CB 2 receptor and are promising candidates for primate and human CB 2 PET imaging.

  7. Graphene crystal growth by thermal precipitation of focused ion beam induced deposition of carbon precursor via patterned-iron thin layers

    Directory of Open Access Journals (Sweden)

    Rius Gemma

    2014-01-01

    Full Text Available Recently, relevant advances on graphene as a building block of integrated circuits (ICs have been demonstrated. Graphene growth and device fabrication related processing has been steadily and intensively powered due to commercial interest; however, there are many challenges associated with the incorporation of graphene into commercial applications which includes challenges associated with the synthesis of this material. Specifically, the controlled deposition of single layer large single crystal graphene on arbitrary supports, is particularly challenging. Previously, we have reported the first demonstration of the transformation of focused ion beam induced deposition of carbon (FIBID-C into patterned graphitic layers by metal-assisted thermal treatment (Ni foils. In this present work, we continue exploiting the FIBID-C approach as a route for graphene deposition. Here, thin patterned Fe layers are used for the catalysis of graphenization and graphitization. We demonstrate the formation of high quality single and few layer graphene, which evidences, the possibility of using Fe as a catalyst for graphene deposition. The mechanism is understood as the minute precipitation of atomic carbon after supersaturation of some iron carbides formed under a high temperature treatment. As a consequence of the complete wetting of FIBID-C and patterned Fe layers, which enable graphene growth, the as-deposited patterns do not preserve their original shape after the thermal treatment

  8. Carbon-11 labelling of S38419, a novel alpha-4-beta-2-selective ligand for PET imaging of nicotinic acetylcholine receptors

    International Nuclear Information System (INIS)

    Dolle, F.; Demphel, St.; Saba, W.; Schollhorn-Peyronneau, M.A.; Deverre, J.R.; Bottlaender, M.; Valette, H.; Charton, Y.; Goldstein, S.; Lestage, P.

    2011-01-01

    Complete text of publication follows: Objectives: There is considerable evidence that a variety of functions and disorders (e.g. Alzheimer's and Parkinson's disease) of the CNS is associated with the neuronal nicotinic acetylcholine receptors and particularly with the subtypes containing α4 and β2 subunits (nAChRs). The consistent and severe loss of these receptors in the diseases mentioned above has prompted extensive efforts, over more than two decades now, into the design of PET radioligands for non-invasive in vivo imaging of these receptors and the quantification of their density in the human brain. Not only analogues of the alkaloid epibatidine were labelled with positron-emitters but also series of 3-pyridyl ethers bearing either the traditional nicotinic-like pyrrolidine ring (e.g. [ 11 C]A-84543) or the azetidine motive (e.g. 2-[ 18 F]F-A-85380). Novel structures, still possessing high affinity and selectivity for nAChRs but not displaying any saturated, nitrogen-containing, 5- or 4-membered rings were also reported (e.g. [ 11 C]p-PVPMEMA). Recently, a novel series of highly potent α4β2-selective 3-pyridinamines (exhibiting a cyclopropane ring together with a non-cyclic amino function) has been developed by Servier Laboratories. Within this series, S38419 (1, N-methyl-N-[[1-(methylamino)cyclopropyl]methyl]pyridin-3-amine) was selected on the basis of its pharmacological and biological characteristics as a potent candidate for PET imaging and was isotopically labelled with carbon-11 using [ 11 C]methyl triflate. Methods: Carbon-11 labelling of S38419 (1) was performed using a TRACERLab FX-C Pro synthesizer (GEMS) and comprises (1) trapping at -10 C of [ 11 C]MeOTf in DMF (0.3 mL) containing the nor-derivative (N-demethylated, 1.8-2.0 mg); (2) heating at 120 C for 2 min; (3) taking up the residue in 1.0 mL of the HPLC mobile phase; (4) purification using semi-preparative reversed-phase HPLC (Waters Symmetry R C-18 - eluent: CH 3 CN / H 2 O / TEA: 20 / 80

  9. TU-AB-BRC-11: Moving a GPU-OpenCL-Based Monte Carlo (MC) Dose Engine Towards Routine Clinical Use: Automatic Beam Commissioning and Efficient Source Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Z; Folkerts, M; Jiang, S; Jia, X [UT Southwestern Medical Ctr, Dallas, TX (United States); Li, Y [Beihang University, Beijing (China)

    2016-06-15

    Purpose: We have previously developed a GPU-OpenCL-based MC dose engine named goMC with built-in analytical linac beam model. To move goMC towards routine clinical use, we have developed an automatic beam-commissioning method, and an efficient source sampling strategy to facilitate dose calculations for real treatment plans. Methods: Our commissioning method is to automatically adjust the relative weights among the sub-sources, through an optimization process minimizing the discrepancies between calculated dose and measurements. Six models built for Varian Truebeam linac photon beams (6MV, 10MV, 15MV, 18MV, 6MVFFF, 10MVFFF) were commissioned using measurement data acquired at our institution. To facilitate dose calculations for real treatment plans, we employed inverse sampling method to efficiently incorporate MLC leaf-sequencing into source sampling. Specifically, instead of sampling source particles control-point by control-point and rejecting the particles blocked by MLC, we assigned a control-point index to each sampled source particle, according to MLC leaf-open duration of each control-point at the pixel where the particle intersects the iso-center plane. Results: Our auto-commissioning method decreased distance-to-agreement (DTA) of depth dose at build-up regions by 36.2% averagely, making it within 1mm. Lateral profiles were better matched for all beams, with biggest improvement found at 15MV for which root-mean-square difference was reduced from 1.44% to 0.50%. Maximum differences of output factors were reduced to less than 0.7% for all beams, with largest decrease being from1.70% to 0.37% found at 10FFF. Our new sampling strategy was tested on a Head&Neck VMAT patient case. Achieving clinically acceptable accuracy, the new strategy could reduce the required history number by a factor of ∼2.8 given a statistical uncertainty level and hence achieve a similar speed-up factor. Conclusion: Our studies have demonstrated the feasibility and effectiveness of

  10. Geant4 simulation for a study of a possible use of carbon ions pencil beam for the treatment of ocular melanomas with the active scanning system at CNAO Centre

    International Nuclear Information System (INIS)

    Farina, E.; Piersimoni, P.; Riccardi, C.; Rimoldi, A.; Tamborini, A.; Ciocca, M.

    2015-01-01

    The aim of this work is to validate the Geant4 application reproducing the CNAO (National Centre for Oncological Hadrontherapy) beamline and to study of a possible use of carbon ion pencil beams for the treatment of ocular melanomas at the CNAO Centre. The promising aspect of carbon ions radiotherapy for the treatment of this disease lies in its superior relative radiobiological effectiveness (RBE). The Monte Carlo Geant4 toolkit is used to simulate the complete CNAO extraction beamline, with the active and passive components along it. A human eye modeled detector, including a realistic target tumor volume, is used as target. Cross check with previous studies at CNAO using protons allows comparisons on possible benefits on using such a technique with respect to proton beams. Before the eye-detector irradiation a validation of the Geant4 simulation with CNAO experimental data is carried out with both carbon ions and protons. Important beam parameters such as the transverse FWHM and scanned radiation field 's uniformity are tested within the simulation and compared with experimental measurements at CNAO Centre. The physical processes involved in secondary particles generation by carbon ions and protons in the eye-detector are reproduced to take into account the additional dose to the primary beam given to irradiated eye's tissues. A study of beam shaping is carried out to produce a uniform 3D dose distribution (shaped on the tumor) by the use of a spread out Bragg peak. The eye-detector is then irradiated through a two dimensional transverse beam scan at different depths. In the use case the eye-detector is rotated of an angle of 40 deg. in the vertical direction, in order to mis-align the tumor from healthy tissues in front of it. The treatment uniformity on the tumor in the eye-detector is tested. For a more quantitative description of the deposited dose in the eye-detector and for the evaluation of the ratio between the dose deposited in the tumor and

  11. Geant4 simulation for a study of a possible use of carbon ions pencil beam for the treatment of ocular melanomas with the active scanning system at CNAO Centre

    Energy Technology Data Exchange (ETDEWEB)

    Farina, E. [University of Pavia-Department of Physics, via Bassi 6, 27100 Pavia (Italy); Piersimoni, P. [Division of Radiation Research, Loma Linda University, Loma Linda, CA 92354 (United States); Riccardi, C.; Rimoldi, A.; Tamborini, A. [University of Pavia-Department of Physics, via Bassi 6, 27100 Pavia (Italy); INFN Section of Pavia, via Bassi 6, 27100 Pavia (Italy); Ciocca, M. [Medical Physics Unit, Centro Nazionale di Adroterapia Oncologica - CNAO Foundation, Strada Campeggi 53, 27100 Pavia (Italy)

    2015-07-01

    The aim of this work is to validate the Geant4 application reproducing the CNAO (National Centre for Oncological Hadrontherapy) beamline and to study of a possible use of carbon ion pencil beams for the treatment of ocular melanomas at the CNAO Centre. The promising aspect of carbon ions radiotherapy for the treatment of this disease lies in its superior relative radiobiological effectiveness (RBE). The Monte Carlo Geant4 toolkit is used to simulate the complete CNAO extraction beamline, with the active and passive components along it. A human eye modeled detector, including a realistic target tumor volume, is used as target. Cross check with previous studies at CNAO using protons allows comparisons on possible benefits on using such a technique with respect to proton beams. Before the eye-detector irradiation a validation of the Geant4 simulation with CNAO experimental data is carried out with both carbon ions and protons. Important beam parameters such as the transverse FWHM and scanned radiation field 's uniformity are tested within the simulation and compared with experimental measurements at CNAO Centre. The physical processes involved in secondary particles generation by carbon ions and protons in the eye-detector are reproduced to take into account the additional dose to the primary beam given to irradiated eye's tissues. A study of beam shaping is carried out to produce a uniform 3D dose distribution (shaped on the tumor) by the use of a spread out Bragg peak. The eye-detector is then irradiated through a two dimensional transverse beam scan at different depths. In the use case the eye-detector is rotated of an angle of 40 deg. in the vertical direction, in order to mis-align the tumor from healthy tissues in front of it. The treatment uniformity on the tumor in the eye-detector is tested. For a more quantitative description of the deposited dose in the eye-detector and for the evaluation of the ratio between the dose deposited in the tumor and

  12. Obtention of thermoluminescent efficiencies by means of irradiation of TLD-100 dosemeters with proton beams helium and carbon

    International Nuclear Information System (INIS)

    Avila, O.; Rodriguez V, M.; Aviles, P.; Gamboa de Buen, I.; Buenfil, A.E.; Ruiz T, C.; Brandan, M.E.

    2002-01-01

    In this work, the advances of a serial of measurements of relative efficiency thermoluminescent of heavy charged particles (PCP) with respect to gamma radiation for TLD-100, dosemeters of LiF: Mg,Ti manufactured by the Harshaw-Bicron company are reported. The PCP are essentials in the implementation of dosimetry associated with medical applications. The measurements before gamma radiation were carrying out using the Vickrad irradiator of the National Institute of Nuclear Research at dose of 1.663 Gy. The measures which are reported about protons, helium and carbon were realized using the Pelletron accelerator of the Physics Institute of the UNAM. (Author)

  13. Human dosimetry of carbon-11 labeled N-butan-2-yl-1-(2-chlorophenyl)-N-methylisoquinoline-3-carboxamide extrapolated from whole-body distribution kinetics and radiometabolism in rats

    DEFF Research Database (Denmark)

    Luoto, Pauliina; Laitinen, Iina; Suilamo, Sami

    2010-01-01

    Carbon-11 labeled N-butan-2-yl-1-(2-chlorophenyl)-N-methylisoquinoline-3-carboxamide ([11C]PK11195) is a peripheral benzodiazepine receptor (PBR) antagonist that is used as a positron emission tomography (PET) radiopharmaceutical for neuroinflammatory imaging. This study was designed to investigate...

  14. HIBP primary beam detector

    International Nuclear Information System (INIS)

    Schmidt, T.W.

    1979-01-01

    A position measuring detector was fabricated for the Heavy Ion Beam Probe. The 11 cm by 50 cm detector was a combination of 15 detector wires in one direction and 63 copper bars - .635 cm by 10 cm to measure along an orthogonal axis by means of a current divider circuit. High transmission tungsten meshes provide entrance windows and suppress secondary electrons. The detector dimensions were chosen to resolve the beam position to within one beam diameter

  15. High purity radioactive beams at the bevalac

    International Nuclear Information System (INIS)

    Alonso, J.R.; Chatterjee, A.; Tobias, C.A.

    1979-03-01

    Peripheral nuclear fragmentation reactions of primary Bevalac heavy ion beams are used to produce secondary beams of radioactive nuclei. The large cross section and small deflection of the projectile fragments lead to high production and delivery efficiency for these beams. Dispersive beam transport allows good separation and purification of the desired secondary beams. 11 C and 19 Ne beams of high purity and good intensity (almost 0.2% of the primary beam current) are presently being used for biomedical experiments

  16. Coupling carbon nanotube film microextraction with desorption corona beam ionization for rapid analysis of Sudan dyes (I-IV) and Rhodamine B in chilli oil.

    Science.gov (United States)

    Chen, Di; Huang, Yun-Qing; He, Xiao-Mei; Shi, Zhi-Guo; Feng, Yu-Qi

    2015-03-07

    A rapid analysis method by coupling carbon nanotube film (CNTF) microextraction with desorption corona beam ionization (DCBI) was developed for the determination of Sudan dyes (I-IV) and Rhodamine B in chilli oil samples. Typically, CNTF was immersed into the diluted solution of chilli oil for extraction, which was then placed directly under the visible plasma beam tip of the DCBI source for desorption and ionization. Under optimized conditions, five dyes were simultaneously determined using this method. Results showed that the analytes were enriched by the CNTF through the π-π interactions, and the proposed method could significantly improve the sensitivities of these compounds, compared to the direct analysis by DCBI-MS/MS. The method with a linear range of 0.08-12.8 μg g(-1) and good linear relationships (R(2) > 0.93) in a multiple reaction monitoring (MRM) mode was developed. Satisfactory reproducibility was achieved. Relative standard deviations (RSDs) were less than 20.0%. The recoveries ranged from 80.0 to 110.0%, and the limits of detection (LODs) were in the range of 1.4-21 ng g(-1). Finally, the feasibility of the method was further exhibited by the determination of five illegal dyes in chilli powder. These results demonstrate that the proposed method consumes less time and solvent than conventional HPLC-based methods and avoids the contamination of chromatographic column and ion source from non-volatile oil. With the help of a 72-well shaker, multiple samples could be treated simultaneously, which ensures high throughput for the entire pretreatment process. In conclusion, it provides a rapid and high-throughput approach for the determination of such illicit additions in chilli products.

  17. Beam-beam phenomenology

    International Nuclear Information System (INIS)

    Teng, L.C.

    1980-01-01

    In colliding beam storage rings the beam collision regions are generally so short that the beam-beam interaction can be considered as a series of evenly spaced non-linear kicks superimposed on otherwise stable linear oscillations. Most of the numerical studies on computers were carried out in just this manner. But for some reason this model has not been extensively employed in analytical studies. This is perhaps because all analytical work has so far been done by mathematicians pursuing general transcendental features of non-linear mechanics for whom this specific model of the specific system of colliding beams is too parochial and too repugnantly physical. Be that as it may, this model is of direct interest to accelerator physicists and is amenable to (1) further simplification, (2) physical approximation, and (3) solution by analogy to known phenomena

  18. Margin estimation and disturbances of irradiation field in layer-stacking carbon-ion beams for respiratory moving targets.

    Science.gov (United States)

    Tajiri, Shinya; Tashiro, Mutsumi; Mizukami, Tomohiro; Tsukishima, Chihiro; Torikoshi, Masami; Kanai, Tatsuaki

    2017-11-01

    Carbon-ion therapy by layer-stacking irradiation for static targets has been practised in clinical treatments. In order to apply this technique to a moving target, disturbances of carbon-ion dose distributions due to respiratory motion have been studied based on the measurement using a respiratory motion phantom, and the margin estimation given by the square root of the summation Internal margin2+Setup margin2 has been assessed. We assessed the volume in which the variation in the ratio of the dose for a target moving due to respiration relative to the dose for a static target was within 5%. The margins were insufficient for use with layer-stacking irradiation of a moving target, and an additional margin was required. The lateral movement of a target converts to the range variation, as the thickness of the range compensator changes with the movement of the target. Although the additional margin changes according to the shape of the ridge filter, dose uniformity of 5% can be achieved for a spherical target 93 mm in diameter when the upward range variation is limited to 5 mm and the additional margin of 2.5 mm is applied in case of our ridge filter. Dose uniformity in a clinical target largely depends on the shape of the mini-peak as well as on the bolus shape. We have shown the relationship between range variation and dose uniformity. In actual therapy, the upper limit of target movement should be considered by assessing the bolus shape. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  19. Microstructure and property of diamond-like carbon films with Al and Cr co-doping deposited using a hybrid beams system

    International Nuclear Information System (INIS)

    Dai, Wei; Liu, Jingmao; Geng, Dongsen; Guo, Peng; Zheng, Jun; Wang, Qimin

    2016-01-01

    Highlights: • Diamond-like carbon films with Al and Cr doping were deposited. • Alternate multilayered structure consisted of Al-poor layer and Al-rich layer was formed. • The periodic Al-rich layers can greatly improve the residual stress and elastic resilience of the films. - Abstract: DLC films with weak carbide former Al and carbide former Cr co-doping (Al:Cr-DLC) were deposited by a hybrid beams system comprising an anode-layer linear ion beam source (LIS) and high power impulse magnetron sputtering using a gas mixture of C 2 H 2 and Ar as the precursor. The doped Al and Cr contents were controlled via adjusting the C 2 H 2 fraction in the gas mixture. The composition, microstructure, compressive stress, mechanical properties and tribological behaviors of the Al:Cr-DLC films were researched carefully using X-ray photoelectron spectroscopy, transmission electron microscopy, Raman spectroscopy, stress-tester, nanoindentation and ball-on-plate tribometer as function of the C 2 H 2 fraction. The results show that the Al and Cr contents in the films increased continuously as the C 2 H 2 fraction decreased. The doped Cr atoms preferred to bond with the carbon while the Al atoms mainly existed in metallic state. Structure modulation with alternate multilayer consisted of Al-poor DLC layer and Al-rich DLC layer was found in the films. Those periodic Al-rich DLC layers can effectively release the residual stress of the films. On the other hand, the formation of the carbide component due to Cr incorporation can help to increase the film hardness. Accordingly, the residual stress of the DLC films can be reduced without sacrificing the film hardness though co-doping Al and Cr atoms. Furthermore, it was found that the periodic Al-rich layer can greatly improve the elastic resilience of the DLC films and thus decreases the film friction coefficient and wear rate significantly. However, the existence of the carbide component would cause abrasive wear and thus

  20. The relative biological effectiveness for carbon and oxygen ion beams using the raster-scanning technique in hepatocellular carcinoma cell lines.

    Directory of Open Access Journals (Sweden)

    Daniel Habermehl

    Full Text Available BACKGROUND: Aim of this study was to evaluate the relative biological effectiveness (RBE of carbon (12C and oxygen ion (16O-irradiation applied in the raster-scanning technique at the Heidelberg Ion beam Therapy center (HIT based on clonogenic survival in hepatocellular carcinoma cell lines compared to photon irradiation. METHODS: Four human HCC lines Hep3B, PLC, HepG2 and HUH7 were irradiated with photons, 12C and 16O using a customized experimental setting at HIT for in-vitro trials. Cells were irradiated with increasing physical photon single doses of 0, 2, 4 and 6 Gy and heavy ion-single doses of 0, 0.125, 0.5, 1, 2, 3 Gy (12C and 16O. SOBP-penetration depth and extension was 35 mm +/-4 mm and 36 mm +/-5 mm for carbon ions and oxygen ions respectively. Mean energy level and mean linear energy transfer (LET were 130 MeV/u and 112 keV/um for 12C, and 154 MeV/u and 146 keV/um for 16O. Clonogenic survival was computated and relative biological effectiveness (RBE values were defined. RESULTS: For all cell lines and both particle modalities α- and β-values were determined. As expected, α-values were significantly higher for 12C and 16O than for photons, reflecting a steeper decline of the initial slope of the survival curves for high-LET beams. RBE-values were in the range of 2.1-3.3 and 1.9-3.1 for 12C and 16O, respectively. CONCLUSION: Both irradiation with 12C and 16O using the raster-scanning technique leads to an enhanced RBE in HCC cell lines. No relevant differences between achieved RBE-values for 12C and 16O were found. Results of this work will further influence biological-adapted treatment planning for HCC patients that will undergo particle therapy with 12C or 16O.

  1. Microstructure and property of diamond-like carbon films with Al and Cr co-doping deposited using a hybrid beams system

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Wei, E-mail: popdw@126.com [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Liu, Jingmao; Geng, Dongsen [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Guo, Peng [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zheng, Jun [Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Wang, Qimin, E-mail: qmwang@gdut.edu.cn [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006 (China)

    2016-12-01

    Highlights: • Diamond-like carbon films with Al and Cr doping were deposited. • Alternate multilayered structure consisted of Al-poor layer and Al-rich layer was formed. • The periodic Al-rich layers can greatly improve the residual stress and elastic resilience of the films. - Abstract: DLC films with weak carbide former Al and carbide former Cr co-doping (Al:Cr-DLC) were deposited by a hybrid beams system comprising an anode-layer linear ion beam source (LIS) and high power impulse magnetron sputtering using a gas mixture of C{sub 2}H{sub 2} and Ar as the precursor. The doped Al and Cr contents were controlled via adjusting the C{sub 2}H{sub 2} fraction in the gas mixture. The composition, microstructure, compressive stress, mechanical properties and tribological behaviors of the Al:Cr-DLC films were researched carefully using X-ray photoelectron spectroscopy, transmission electron microscopy, Raman spectroscopy, stress-tester, nanoindentation and ball-on-plate tribometer as function of the C{sub 2}H{sub 2} fraction. The results show that the Al and Cr contents in the films increased continuously as the C{sub 2}H{sub 2} fraction decreased. The doped Cr atoms preferred to bond with the carbon while the Al atoms mainly existed in metallic state. Structure modulation with alternate multilayer consisted of Al-poor DLC layer and Al-rich DLC layer was found in the films. Those periodic Al-rich DLC layers can effectively release the residual stress of the films. On the other hand, the formation of the carbide component due to Cr incorporation can help to increase the film hardness. Accordingly, the residual stress of the DLC films can be reduced without sacrificing the film hardness though co-doping Al and Cr atoms. Furthermore, it was found that the periodic Al-rich layer can greatly improve the elastic resilience of the DLC films and thus decreases the film friction coefficient and wear rate significantly. However, the existence of the carbide component would

  2. Carbonization

    Energy Technology Data Exchange (ETDEWEB)

    Hennebutte, H G; Goutal, E

    1921-07-04

    Materials such as coal, peat, or schist are subjected to a rising temperature in successive stages in apparatus in which the distillation products are withdrawn at each stage. For example in a three-stage process, the acid products of the first or low-temperature stage are fixed in a suitable reagent, the basic products from a second or higher-temperature stage are absorbed in an acid reagent, hydrocarbons being retained by solvents, while the third are subjected to a pyrogenation process carried out in a closed vessel. Wherein the material is subjected in stages to a rising temperature, the gasified products being withdrawn at each stage, and are prevented as far as possible from mixing with the carbonized products.

  3. (Vapor + liquid) equilibrium data for (carbon dioxide + 1,1-difluoroethane) system at temperatures from (258 to 343) K and pressures up to about 8 MPa

    International Nuclear Information System (INIS)

    Madani, Hakim; Valtz, Alain; Coquelet, Christophe; Meniai, Abdeslam Hassen; Richon, Dominique

    2008-01-01

    Accurate thermo-physical data are of utmost interest for the development of new efficient refrigeration systems. Carbon dioxide (R744) and 1,1-difluoroethane (R152a) are addressed here. Isothermal (vapor + liquid) equilibrium data are reported herein for (R744 + R152a) binary system in the (258-343) K temperature range and in the (0.14 to 7.65) MPa pressure range. A reliable 'static-analytic' method taking advantage of two online ROLSI TM micro capillary samplers is used for all thermodynamic measurements. The data are correlated using our in-house ThermoSoft thermodynamic model using the Peng-Robinson equation of state, the Mathias-Copeman alpha function, the Wong-Sandler mixing rules, and the NRTL model

  4. Measurement of intracellular DNA double-strand break induction and rejoining along the track of carbon and neon particle beams in water

    International Nuclear Information System (INIS)

    Heilmann, Johannes; Taucher-Scholz, Gisela; Haberer, Thomas; Scholz, Michael; Kraft, Gerhard

    1996-01-01

    Purpose: The study was aimed at the measurement of effect-depth distributions of intracellularly induced DNA damage in water as tissue equivalent after heavy ion irradiation with therapy particle beams. Methods and Materials: An assay involving embedding of Chinese hamster ovary (CHO-K1) cells in large agarose plugs and electrophoretic elution of radiation induced DNA fragments by constant field gel electrophoresis was developed. Double-strand break production was quantified by densitometric analysis of DNA-fluorescence after staining with ethidium-bromide and determination of the fraction of DNA eluted out of the agarose plugs. Intracellular double-strand break induction and the effect of a 3 h rejoining incubation were investigated following irradiation with 250 kV x-rays and 190 MeV/u carbon- and 295 MeV/u neon-ions. Results and Conclusion: While the DNA damage induced by x-irradiation decreased continuously with penetration depth, a steady increase in the yield of double-strand breaks was observed for particle radiation, reaching distinct maxima at the position of the physical Bragg peaks. Beyond this, the extent of radiation damage dropped drastically. From comparison of DNA damage and calculated dose profiles, relative biological efficiencies (RBEs) for both double-strand break induction and unrejoined strand breaks after 3 h were determined. While RBE for the induction of DNA double-strand breaks decreased continuously with penetration depth, RBE maxima greater than unity were found with carbon- and neon-ions for double-strand break rejoining near the maximum range of the particles. The method presented here allows for a fast and accurate determination of depth profiles of relevant radiobiological effects for mixed particle fields in tissue equivalent

  5. Production of an accelerated oxygen-14 beam

    CERN Document Server

    Powell, J; Cerny, J

    2003-01-01

    BEARS is an ongoing project to provide a light-ion radioactive-beam capability at the 88-Inch Cyclotron at LBNL. Light radioactive isotopes are produced at a 10 MeV proton medical cyclotron, transported 350 m via a high-speed gas transport capillary, cryogenically separated, and injected into the 88-Inch Cyclotron's ion source. The first radioactive beam successfully accelerated was carbon-11 and beams of intensity more than 10 sup 8 ions/s have been utilized for experiments. Development of oxygen-14 as the second BEARS beam presented considerable technical challenges, both due to its short half-life of 71 s and the radiation chemistry of oxygen in the target. The usual techniques developed for medical uses of oxygen-15 involve the addition of significant amounts of carrier oxygen, something that would overload the ion source. As a solution, oxygen-14 is produced as water in a carrier-free form, and is chemically converted in two steps to carbon dioxide, a form readily usable by the BEARS. This system has bee...

  6. Selectivity in catalytic alkyne cyclotrimerization over chromium(VI): kinetic evaluation using the characteristics of radioactive carbon-11 decay for nondisruptive ultrasensitive detection of adsorbed species

    International Nuclear Information System (INIS)

    Ferrieri, R.A.; Wolf, A.P.

    1984-01-01

    The application of carbon-11 to kinetic measurements of molecular sorption is reported using positron annihilation surface detection (PASD). The technique is nondisruptive to dynamic processes and has the sensitivity to detect 10 -8 of a monolayer. In studies of alkyne cyclomerization on silica-alumina-supported Cr(VI), a high selectivity toward p-xylene formation was observed when acetylene-propyne mixtures were cotrimerized at monolayer total alkyne coverages. This selectivity was enhanced to 84% p-xylene, as the partial acetylene coverage was reduced to 1.0% of a monolayer. Competitive sorption studies utilized PASD to measure the surface concentration of [ 11 C]-acetylene coupled with macroscopic sorption measurements of propyne. Surface displacement of sorbed acetylene by propyne was observed with subsequent readsorption. The kinetics of this displacement were evaluated by using PASD in pulse-flow studies with various acetylene and propyne coverages and were modeled to a calculation of the isomeric xylene distribution. A near-identical fit was obtained between experimental and modeled results. This strongly suggested that the observed selectivity for p-xylene formation was due to sorbate interactions resulting in a specific molecular ordering of the alkyne mixture on the catalyst surface

  7. Cross-beam pulsed laser fabrication of Free-Standing Nanostructured Carbon Nanotubes-Pt-Ceria Anode with unprecedented electroactivity and durability for ethanol oxidation

    Science.gov (United States)

    Wang, Youling; Tabet-Aoul, Amel; Gougis, Maxime; Mohamedi, Mohamed

    2015-01-01

    Owing to its inherent properties such as great capacity to store and release oxygen, lattice oxygen that has a key role in removing the CO poisoning effect, non-toxicity, abundance, low cost and low temperature processing, CeO2 is emerging as a unique class of electrode material for low temperature polymer electrolyte fuel cells such as direct ethanol fuel cells (DEFCs). However, the maximal exploitation of its functional properties is strictly reliant on the availability of optimized synthesis routes that allow tailor-designing, architecturing and manipulation of CeO2 in a precise manner when it is combined with other functional materials. Here we use the cross-beam pulsed laser deposition (CBPLD) technique to synthesize free-standing (binderless) Pt-CeO2 nanostructured thin films onto carbon nanotubes as anodes for ethanol oxidation reaction. Further significance of this work is that it establishes the importance in the design of the catalyst layer architecture. Indeed, we demonstrate here that when CeO2 material is beneath or when it is mixed with Pt, the interactions between Pt with CeO2 are not similar leading inevitably to different electrocatalytic performances. Given proper tailoring synthesis conditions, CBPLD-developed Pt-CeO2 thin films are remarkably stable and provide electrochemical performance much greater than the layer onto layer CeO2/Pt architecture.

  8. Site-specific forest-assembly of single-wall carbon nanotubes on electron-beam patterned SiOx/Si substrates

    International Nuclear Information System (INIS)

    Wei Haoyan; Kim, Sang Nyon; Kim, Sejong; Huey, Bryan D.; Papadimitrakopoulos, Fotios; Marcus, Harris L.

    2008-01-01

    Based on electron-beam direct writing on the SiO x /Si substrates, favorable absorption sites for ferric cations (Fe 3+ ions) were created on the surface oxide layer. This allowed Fe 3+ -assisted self-assembled arrays of single-wall carbon nanotube (SWNT) probes to be produced. Auger investigation indicated that the incident energetic electrons depleted oxygen, creating more dangling bonds around Si atoms at the surface of the SiO x layer. This resulted in a distinct difference in the friction forces from unexposed regions as measured by lateral force microscopy (LFM). Atomic force microscopy (AFM) affirmed that the irradiated domains absorbed considerably more Fe 3+ ions upon immersion into pH 2.2 aqueous FeCl 3 solution. This rendered a greater yield of FeO(OH)/FeOCl precipitates, primarily FeO(OH), upon subsequent washing with lightly basic dimethylformamide (DMF) solution. Such selective metal-functionalization established the basis for the subsequent patterned forest-assembly of SWNTs as demonstrated by resonance Raman spectroscopy

  9. 3D assembly of carbon nanotubes for fabrication of field-effect transistors through nanomanipulation and electron-beam-induced deposition

    International Nuclear Information System (INIS)

    Yu, Ning; Shi, Qing; Wang, Huaping; Huang, Qiang; Fukuda, Toshio; Nakajima, Masahiro; Yang, Zhan; Sun, Lining

    2017-01-01

    Three-dimensional carbon nanotube field-effect transistors (3D CNTFETs) possess predictable characteristics that rival those of planar CNTFETs and Si-based MOSFETs. However, due to the lack of a reliable assembly technology, they are rarely reported on, despite the amount of attention they receive. To address this problem, we propose the novel concept of a 3D CNTFET and develop its assembly strategy based on nanomanipulation and the electron-beam-induced deposition (EBID) technique inside a scanning electron microscope (SEM). In particular, the electrodes in our transistor design are three metallic cuboids of the same size, and their front, top and back surfaces are all wrapped up in CNTs. The assembly strategy is employed to build the structure through a repeated basic process of pick-up, placement, fixing and cutting of CNTs. The pick-up and placement is performed through one nanomanipulator with four degrees of freedom. Fixing is carried out through the EBID technique so as to improve the mechanical and electrical characteristics of the CNT/electrodes connection. CNT cutting is undertaken using the typical method of electrical breakdown. Experimental results showed that two CNTs were successfully assembled on the front sides of the cubic electrodes. This validates our assembly method for the 3D CNTFET. Also, when contact resistance was measured, tens of kilohms of resistance was observed at the CNT-EBID deposition-FET electrodes junction.. This manifests the electrical reliability of our assembly strategy. (paper)

  10. PARP-1 is a key player in controlling apoptosis induced by high LET carbon ion beam and low LET gamma radiation in HeLa cells

    International Nuclear Information System (INIS)

    Ghorai, Atanu; Ghosh, Utpal; Bhattacharyya, Nitai P.; Sarma, Asitikantha

    2014-01-01

    PARP-1 inhibitors have long been used as chemo-sensitizer or radio-sensitizer and specific PARP-1 inhibitors are also in clinical trial for the treatment of various cancers. PARP-1 is not only involved in DNA repair but also plays very complex role in induction of apoptosis in postirradiation condition. Our objective is to investigate role of PARP-1 in apoptosis triggered by high LET carbon ion beam (CIB) and low LET gamma. We have treated HeLa and PARP-1 knock down HeLa (Hsil) cells with various doses of CIB and gamma. We measured DNA damage by comet assay and various apoptotic parameters such as nuclear fragmentation, activation of caspase-3,8,9, AIF translocation etc. We observed higher DNA breaks and also higher apoptosis in HsiI cells compared with HeLa cells. Both CIB and gamma treatment results G2/M arrest but unlike gamma CIB makes S-phase delay, implicating that gamma and CIB triggers different pathway after DNA damage. Cell death by CIB or by gamma increased up on knocking down of PARP-1 but increase is higher for high LET CIB compared with low LET gamma. Furthermore, expression level of PARP-1 controls the intensity of overall apoptosis in cells in post-irradiation condition. So, combination of PARP-1 inhibition with high LET CIB could be a promising tool to combat cancer. (author)

  11. Production of radioactive molecular beams for CERN-ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Seiffert, Christoph

    2015-06-15

    ISOLDE, the Isotope Separation On-Line facility, at CERN is a leading facility for the production of beams of exotic radioactive isotopes. Currently over 1000 different isotopes with half lives down to milliseconds can be extracted with beam intensities of up to 10{sup 11} ions per second. However, due to the reactive target environment not all isotopes are extractable in sufficient amounts. In this work the extraction of short lived carbon and boron isotopes is investigated. Therefore a variety of experimental and computational techniques have been used.

  12. Production of radioactive molecular beams for CERN-ISOLDE

    CERN Document Server

    AUTHOR|(SzGeCERN)703149; Kröll, Thorsten

    SOLDE, the Isotope Separation On-Line facility, at CERN is a leading facility for the production of beams of exotic radioactive isotopes. Currently over 1000 different isotopes with half lives down to milliseconds can be extracted with beam intensities of up to 10^11 ions per second. However, due to the reactive target environment not all isotopes are extractable in sufficient amounts. In this work the extraction of short lived carbon and boron isotopes is investigated. Therefore a variety of experimental and computanional techniques have been used.

  13. Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams.

    Science.gov (United States)

    Takano, Nao; Takahashi, Yuko; Yamamoto, Mitsuru; Teranishi, Mika; Yamaguchi, Hiroko; Sakamoto, Ayako N; Hase, Yoshihiro; Fujisawa, Hiroko; Wu, Jianzhong; Matsumoto, Takashi; Toki, Seiichi; Hidema, Jun

    2013-07-01

    UVB radiation suppresses photosynthesis and protein biosynthesis in plants, which in turn decreases growth and productivity. Here, an ultraviolet-B (UVB)-tolerant rice mutant, utr319 (UV Tolerant Rice 319), was isolated from a mutagenized population derived from 2500 M1 seeds (of the UVB-resistant cultivar 'Sasanishiki') that were exposed to carbon ions. The utr319 mutant was more tolerant to UVB than the wild type. Neither the levels of UVB-induced cyclobutane pyrimidine dimers (CPDs) or (6-4) pyrimidine-pyrimidone photodimers [(6-4) photoproducts], nor the repair of CPDs or (6-4) photoproducts, was altered in the utr319 mutant. Thus, the utr319 mutant may be impaired in the production of a previously unidentified factor that confers UVB tolerance. To identify the mutated region in the utr319 mutant, microarray-based comparative genomic hybridization analysis was performed. Two adjacent genes on chromosome 7, Os07g0264900 and Os07g0265100, were predicted to represent the mutant allele. Sequence analysis of the chromosome region in utr319 revealed a deletion of 45 419 bp. RNAi analysis indicated that Os07g0265100 is most likely the mutated gene. Database analysis indicated that the Os07g0265100 gene, UTR319, encodes a putative protein with unknown characteristics or function. In addition, the homologs of UTR319 are conserved only among land plants. Therefore, utr319 is a novel UVB-tolerant rice mutant and UTR319 may be crucial for the determination of UVB sensitivity in rice, although the function of UTR319 has not yet been determined.

  14. Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams

    International Nuclear Information System (INIS)

    Takano, Nao; Takahashi, Yuko; Yamamoto, Mitsuru; Teranishi, Mika; Yamaguchi, Hiroko; Sakamoto, Ayako N.; Hase, Yoshihiro; Fujisawa, Hiroko; Wu, Jianzhong; Matsumoto, Takashi; Toki, Seiichi; Hidema, Jun

    2013-01-01

    UVB radiation suppresses photosynthesis and protein biosynthesis in plants, which in turn decreases growth and productivity. Here, an ultraviolet-B (UVB)-tolerant rice mutant, utr319 (UVTolerantRice319), was isolated from a mutagenized population derived from 2500 M 1 seeds (of the UVB-resistant cultivar ‘Sasanishiki’) that were exposed to carbon ions. The utr319 mutant was more tolerant to UVB than the wild type. Neither the levels of UVB-induced cyclobutane pyrimidine dimers (CPDs) or (6-4) pyrimidine-pyrimidone photodimers [(6-4) photoproducts], nor the repair of CPDs or (6-4) photoproducts, was altered in the utr319 mutant. Thus, the utr319 mutant may be impaired in the production of a previously unidentified factor that confers UVB tolerance. To identify the mutated region in the utr319 mutant, microarray-based comparative genomic hybridization analysis was performed. Two adjacent genes on chromosome 7, Os07g0264900 and Os07g0265100, were predicted to represent the mutant allele. Sequence analysis of the chromosome region in utr319 revealed a deletion of 45 419 bp. RNAi analysis indicated that Os07g0265100 is most likely the mutated gene. Database analysis indicated that the Os07g0265100 gene, UTR319, encodes a putative protein with unknown characteristics or function. In addition, the homologs of UTR319 are conserved only among land plants. Therefore, utr319 is a novel UVB-tolerant rice mutant and UTR319 may be crucial for the determination of UVB sensitivity in rice, although the function of UTR319 has not yet been determined

  15. Carbon supported nanoparticles Pt Ru (Pt Ru/C electrocatalysts) prepared using electron beam irradiation; Preparacao de nanoparticulas de PtRu suportadas em carbono (eletrocatalisadores PtRu/C) utilizando feixe de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F. da; Oliveira Neto, Almir; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Programa de Celulas a Combustivel], e-mail: espinace@ipen.br, e-mail: dfsilva@ipen.br

    2006-07-01

    Carbon-supported Pt Ru (electrocatalysts PtRu/C nanoparticles) were prepared submitting a water/ethylene glycol mixture containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The PtRu/C electrocatalysts were characterized by EDX, XRD and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained PtRu/C electrocatalysts were more active for methanol electro-oxidation than the commercial PtRu/C ETEK electrocatalyst at ambient temperature. (author)

  16. WE-DE-207B-11: Implementation of Size-Specific 3D Beam Modulation Filters On a Dedicated Breast CT Platform Using Breast Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, A [Department of Radiology, Biomedical Engineering Graduate Group, University of California Davis, Sacramento, CA (United States); Boone, J [Departments of Radiology and Biomedical Engineering, University of California Davis, Sacramento, CA (United States)

    2016-06-15

    Purpose: To implement a 3D beam modulation filter (3D-BMF) in dedicated breast CT (bCT) and develop a method for conforming the patient’s breast to a pre-defined shape, optimizing the effects of the filter. This work expands on previous work reporting the methodology for designing a 3D-BMF that can spare unnecessary dose and improve signal equalization at the detector by preferentially filtering the beam in the thinner anterior and peripheral breast regions. Methods: Effective diameter profiles were measured for 219 segmented bCT images, grouped into volume quintiles, and averaged within each group to represent the range of breast sizes found clinically. These profiles were then used to generate five size-specific computational phantoms and fabricate five size-specific UHMW phantoms. Each computational phantom was utilized for designing a size-specific 3D-BMF using previously reported methods. Glandular dose values and projection images were simulated in MCNP6 with and without the 3DBMF using the system specifications of our prototype bCT scanner “Doheny”. Lastly, thermoplastic was molded around each of the five phantom sizes and used to produce a series of breast immobilizers for use in conforming the patient’s breast during bCT acquisition. Results: After incorporating the 3D-BMF, MC simulations estimated an 80% average reduction in the detector dynamic range requirements across all phantom sizes. The glandular dose was reduced on average 57% after normalizing by the number of quanta reaching the detector under the thickest region of the breast. Conclusion: A series of bCT-derived breast phantoms were used to design size-specific 3D-BMFs and breast immobilizers that can be used on the bCT platform to conform the patient’s breast and therefore optimally exploit the benefits of the 3D-BMF. Current efforts are focused on fabricating several prototype 3D-BMFs and performing phantom scans on Doheny for MC simulation validation and image quality analysis

  17. WE-DE-207B-11: Implementation of Size-Specific 3D Beam Modulation Filters On a Dedicated Breast CT Platform Using Breast Immobilization

    International Nuclear Information System (INIS)

    Hernandez, A; Boone, J

    2016-01-01

    Purpose: To implement a 3D beam modulation filter (3D-BMF) in dedicated breast CT (bCT) and develop a method for conforming the patient’s breast to a pre-defined shape, optimizing the effects of the filter. This work expands on previous work reporting the methodology for designing a 3D-BMF that can spare unnecessary dose and improve signal equalization at the detector by preferentially filtering the beam in the thinner anterior and peripheral breast regions. Methods: Effective diameter profiles were measured for 219 segmented bCT images, grouped into volume quintiles, and averaged within each group to represent the range of breast sizes found clinically. These profiles were then used to generate five size-specific computational phantoms and fabricate five size-specific UHMW phantoms. Each computational phantom was utilized for designing a size-specific 3D-BMF using previously reported methods. Glandular dose values and projection images were simulated in MCNP6 with and without the 3DBMF using the system specifications of our prototype bCT scanner “Doheny”. Lastly, thermoplastic was molded around each of the five phantom sizes and used to produce a series of breast immobilizers for use in conforming the patient’s breast during bCT acquisition. Results: After incorporating the 3D-BMF, MC simulations estimated an 80% average reduction in the detector dynamic range requirements across all phantom sizes. The glandular dose was reduced on average 57% after normalizing by the number of quanta reaching the detector under the thickest region of the breast. Conclusion: A series of bCT-derived breast phantoms were used to design size-specific 3D-BMFs and breast immobilizers that can be used on the bCT platform to conform the patient’s breast and therefore optimally exploit the benefits of the 3D-BMF. Current efforts are focused on fabricating several prototype 3D-BMFs and performing phantom scans on Doheny for MC simulation validation and image quality analysis

  18. Particles beams and applications

    International Nuclear Information System (INIS)

    Uzureau, J.L.

    1996-01-01

    This issue of the ''Chocs'' journal is devoted to particles beams used by the D.A.M. (Direction of Military Applications) and to their applications. The concerned beams are limited to those in an energy range from hundred of Kev to several Gev. Light ions (protons, deuterons, alpha) where it is easy to produce neutrons sources and heavy ions (from carbon to gold). (N.C.). 8 refs., 2 figs

  19. Test beam results of the GE1/1 prototype for a future upgrade of the CMS high-$\\eta$ muon system

    CERN Document Server

    Abbaneo, D; Armagnaud, C; Aspell, P; Ban, Y; Bally, S; Benussi, L; Berzano, U; Bianco, S; Bos, J; Bunkowski, K; Cai, J; Chatelain, J P; Christiansen, J; Colafranceschi, S; Colaleo, A; Conde Garcia, A; David, E; de Robertis, G; De Oliveira, R; Duarte Pinto, S; Ferry, S; Formenti, F; Franconi, L; Gnanvo, K; Gutierrez, A; Hohlmann, M; Karchin, P E; Loddo, F; Magazzú, G; Maggi, M; Marchioro, A; Marinov, A; Mehta, K; Merlin, J; Mohapatra, A; Moulik, T; Nemallapudi, M V; Nuzzo, S; Oliveri, E; Piccolo, D; Postema, H; Raffone, G; Rodrigues, A; Ropelewski, L; Saviano, G; Sharma, A; Staib, M J; Teng, H; Tytgat, M; Tupputi, S A; Turini, N; Smilkjovic, N; Villa, M; Zaganidis, N; Zientek, M

    2011-01-01

    Gas Electron Multipliers (GEM) are an interesting technology under consideration for the future upgrade of the forward region of the CMS muon system, specifically in the $1.6<| \\eta |<2.4$ endcap region. With a sufficiently fine segmentation GEMs can provide precision tracking as well as fast trigger information. The main objective is to contribute to the improvement of the CMS muon trigger. The construction of large-area GEM detectors is challenging both from the technological and production aspects. In view of the CMS upgrade we have designed and built the largest full-size Triple-GEM muon detector, which is able to meet the stringent requirements given the hostile environment at the high-luminosity LHC. Measurements were performed during several test beam campaigns at the CERN SPS in 2010 and 2011. The main issues under study are efficiency, spatial resolution and timing performance with different inter-electrode gap configurations and gas mixtures. In this paper results of the performance of the pro...

  20. Effect of beam expansion loss in a carbon nanotube-doped PVA film on passively mode-locked erbium-doped fiber lasers with different feedback ratios

    International Nuclear Information System (INIS)

    Cheng, Kuang-Nan; Chi, Yu-Chieh; Cheng, Chih-Hsien; Lin, Yung-Hsiang; Lo, Jui-Yung; Lin, Gong-Ru

    2014-01-01

    The effect of beam expansion induced divergent loss in a single-wall carbon nanotube (SWCNT) doped polyvinyl alcohol (PVA) based ultrafast saturable absorber (SA) film thickness on the passive mode-locking (PML) performances of erbium-doped fiber lasers are demonstrated. The variation on the PML pulsewidth of the EDFL is discussed by changing the SWCNT-PVA SA film thicknesses, together with adjusting the pumping power and the intra-cavity feedback ratio. An almost 6 dB increment of divergent loss when enlarging the SWCNT-PVA based SA film thickness from 30–130 µm is observed. When shrinking the SA thickness to 30 µm at the largest pumping power of 52.5 mW, the optical spectrum red-shifts to 1558.8 nm with its 3 dB spectral linewidth broadening up to 2.7 nm, while the pulse has already entered the soliton regime with multi-order Kelly sidebands aside the spectral shoulder. The soliton pulsewidth is as short as 790 fs, which is much shorter than those obtained with other thicker SWCNT doped PVA polymer film based SAs; therefore, the peak power from the output of the PML-EDFL is significantly enlarged accompanied by a completely suppressed residual continuous-wave level to achieve the largest on/off extinction ratio. The main mechanism of pulse shortening with reducing thickness of SWCNT doped PVA polymer film based SA is attributed to the limited beam expansion as well as the enlarged modulation depth, which results in shortened soliton pulsewidth with a clean dc background, and broadened spectrum with enriched Kelly sidebands. The increase of total SWCNT amount in the thicker SA inevitably causes a higher linear absorption; hence, the mode-locking threshold also rises accordingly. By enlarging pumping power from 38.5–52.5 mW, the highest ascent on pulse extinction of up to 32 dB is observed among all kinds of feedback conditions. Nevertheless, the enlargement on the extinction slightly decays with increasing the feedback ratio from 30–90

  1. Comparative study of the pharmacokinetics of carbon tetrachloride in the rat following repeated inhalation exposures of 8 and 11.5 hr/day

    International Nuclear Information System (INIS)

    Paustenbach, D.J.; Carlson, G.P.; Christian, J.E.; Born, G.S.

    1986-01-01

    To evaluate whether exposure to inhaled vapors for periods longer than 8 hr/day could affect the rates and routes of elimination, male Sprague-Dawley rats were repeatedly exposed to 100 ppm of radiolabeled carbon tetrachloride ( 14 CCl 4 ) in a closed-loop chamber. One group was exposed for 8 hr/day for 5 days and another group for 11.5 hr/day for 4 days. Two other groups were exposed for either 8 hr/day for 10 of 12 consecutive days or 11.5 hr/day for 7 of 10 days. The elimination of 14 C activity was measured in the expired air, urine, and feces for up to 100 hr following exposure and the pharmacokinetic parameters were determined. Following 2 weeks of exposure to the 8-hr/day schedule, 14 CCl 4 in the breath and 14 C activity in the feces comprised 45 and 48% of the total 14 C excreted, respectively. Following 2 weeks of exposure to the 11.5-hr/day schedule, the values were 32 and 62%, respectively, indicating that repeated exposure to the longer schedule altered the route of elimination of CCl 4 . Regardless of the period of exposure, less than 8% of the inhaled 14 CCl 4 was excreted in the urine and less than 2% was exhaled in the breath as the 14 CO 2 metabolite. Approximately 97-98% of the 14 C activity in the expired air was 14 CCl 4 . The quantities of 14 C noted in the feces and urine suggest that more than 60% of the inhaled CCl 4 was metabolized. Elimination of 14 CCl 4 and 14 CO 2 in the breath followed a two-compartment, first-order pharmacokinetic model (r2 = 0.98). For rats exposed 8 hr/day and 11.5 hr/day for 2 weeks, the average half-lives for elimination of 14 CCl 4 in the breath for the fast (alpha) and slow (beta) phases averaged 96 and 455 min, and 89 and 568 min, respectively. The average alpha and beta half-lives for elimination of 14 CO 2 in the breath

  2. Carbon-11 pb-12: an attempt to visualize the dopamine d{sub 4} receptor in the primate brain with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver E-mail: oliver.langer@psyk.ks.se; Halldin, Christer; Chou Yuanhwa; Sandell, Johan; Swahn, Carl-Gunnar; Naagren, Kjell; Perrone, Roberto; Berardi, Francesco; Leopoldo, Marcello; Farde, Lars

    2000-11-01

    The dopamine D{sub 4} receptor (D{sub 4}R) is expressed in low density in various extrastriatal brain regions. This receptor subtype is discussed in relation to the pathophysiology and treatment of schizophrenia but no selective positron emission tomography (PET) ligand is available to date to study the distribution in vivo. The arylpiperazine derivative N-[2-[4-(4-chlorophenyl)piperazin-1-yl]ethyl]-3-methoxybenzamide (PB-12) is a novel, high-affinity ( K{sub i}=0.040 nM) and selective D{sub 4}R ligand. We radiolabeled PB-12 with carbon-11 (t{sub 1/2} 20.4 min) by O-methylation of the corresponding desmethyl analogue N-[2-[4-(4-chlorophenyl)piperazin-1-yl]ethyl]-3-hydroxybenzamide (LM-190) with [{sup 11}C]methyl triflate. Derivative LM-190 was prepared by condensing 3-hydroxybenzoic acid with the appropriate amine. For the radiolabeling, the incorporation yield was >90% and the total synthesis time including high performance liquid chromatography (HPLC) purification was about 35 min. The specific radioactivity of [{sup 11}C]PB-12 at time of injection was 67-118 GBq{center_dot}{mu}mol{sup -1}. PET studies in a cynomolgus monkey showed a high uptake and widespread distribution of radioactivity in the brain, including the neocortex and thalamus. About 40% of total radioactivity in plasma represented unchanged radioligand at 60 min after injection as determined by HPLC. Pretreatment with the D{sub 4}R ligand 3-{l_brace}[4-(4-chlorophenyl)piperazin-1-yl]methyl{r_brace}-1H-pyrollo[2,3-b]pyridine (L-745,870) prior to radioligand injection failed to demonstrate receptor-specific binding in the monkey brain. Furthermore, the brain radioactivity distribution was left unaffected by pretreating with unlabeled PB-12. This failure to detect a D{sub 4}R-specific signal may be related to a very low density of the D{sub 4}R in primate brain, insufficient binding affinity of the radioligand, and a high background of nonspecific binding. It can be concluded from these findings that

  3. A combined simple bubbling method with high performance liquid chromatography purification strategy, higher radiochemical yield and purity and faster preparation of carbon-11-raclopride.

    Science.gov (United States)

    Huang, Huacheng; Ning, Yanli; Zhang, Bucheng; Lou, Cen

    2015-01-01

    Carbon-11-raclopride (¹¹C-R) is a positron-emitting radiotracer successfully used for the study of cognitive control and widely applied in PET imaging. A simple automated preparation of ¹¹C-R by using the reaction of carbon-(11)-methyl triflate (¹¹C-MeOTF) or ¹¹C-methyl iodide (¹¹C-MeI) with demethylraclopride is described. Specifically we used a simple setup applied an additional "U" reaction vessel for ¹¹C-MeOTf compared with ¹¹C-MeI and assessed the influence of several solvents and of the amount of the percussor for ¹¹C-methylation of demethylraclopride by the bubbling method. The reversal of retention order between product and its precursor has been achieved for ¹¹C-R, enabling collection of the purified ¹¹C-R by using the HPLC column after shorter retention time. By the improved radiosynthesis and purification strategy, ¹¹C-R could be prepared with higher radiochemical yield than that of the previous studies. The yield for ¹¹C-MeOTf was 76% and for ¹¹C-CH3I >26% and with better radiochemical purity (>99% based on both ¹¹C-MeOTf and ¹¹C-MeI) as compared to the previously obtained purity of ¹¹C-R using HPLC method with acetonitrile as a part of mobile phase. Furthermore, by using ethanol as the organic modifier, residual solvent analysis prior to human injection could be avoided and ¹¹C-R could be injected directly following simple dilution and sterile filtration. Improved radiosynthesis and HPLC purification in combination with ethanol containing eluent, extremely shortened the time for preparation of ¹¹C-R, gave a higher radiochemical yield and purity for ¹¹C-R and can be used for multiple and faster synthesis of ¹¹C-R and probably for other ¹¹C-labeled radiopharmaceuticals.

  4. Measurement of activity yields for 12C(#betta#, n)11C, 14N(#betta#, n)13N, and 16O(#betta#, n)15O reactions as a function of electron beam energy and angle from the electron beam using thick target produced bremsstrahlung

    International Nuclear Information System (INIS)

    Piltingsrud, H.V.

    1983-01-01

    The calculation of activity yields from practical photonuclear target systems designed to produce short-lived positron emitting radionuclides for nuclear medicine purposes requires certain basic information. These include a knowledge of the photon source (bremsstrahlung energy spectrum and intensity as a function of angle from the electron beam) and the #betta#, n activation cross section of the secondary target element. A lack of adequate information concerning these parameters motivated the present study in which activity yields for the reactions 12 C(#betta#, n) 11 C, 14 N(#betta#, n) 13 N, and 16 O(#betta#, n) 15 O were measured as a function of energy of and angle from the electron beam between 16 and 30 MeV and 0 0 and 30.5 0 , respectively. The data indicate highly complex relationships between the activity yield and the experimental variables. Also indicated are possible applications of the data to indicate the energy of an electron beam producing a given bremsstrahlung field in which activation measurements are made

  5. Neutron beam experiments using nuclear research reactors: honoring the retirement of professor Bernard W. Wehring -II. 3. Preliminary Experiments to Determine Moisture in Carbon Composites Using PGAA

    International Nuclear Information System (INIS)

    Charlton, W.S.; Dorsey, D.J.

    2001-01-01

    for moisture measurements in composite materials, in addition to numerous other procedures, consists of detailed descriptions of sample-handling requirements. These requirements are in place because of the sensitivity of the gravimetric techniques to any contamination of the sample. The standard also specifies a 15-min restriction on the time allowed for the sample to be outside of its controlled environment for the measurement to be performed. In this study, we performed moisture uptake experiments using a PGAA technique (with the sample enclosed in a helium-filled chamber) to measure the hydrogen content of two carbon composite samples. The samples (which had been soaking in humid air for an undetermined amount of time) were first measured to determine the hydrogen content. Then, one sample was baked in an oven for 10 days at 100 deg. C to remove any moisture in the sample, and the other sample was soaked in 150 ml of de-ionized water for 10 days. Following this, the samples were re-measured to again determine the hydrogen content. The prompt gamma-ray system used in these experiments consisted of a curved neutron guide at beam port 3 of the UT 1-MW TRIGA reactor, a sample positioning system, and a shielded high-purity germanium detector. Lead and Boral shielding surround the detector except for a 2-in.-diam collimated hole focused on the sample and normal to the plane of the neutron guide. The spectra are collected into 16 000 channels using a Canberra DSA-2000 multichannel analyzer system. Figure 1 plots the prompt gamma-ray spectrum acquired during the measurement of one of the samples. As can be seen, the 15-min time frame allotted for the experiment resulted in a clearly discernable hydrogen peak. In fact, the statistical uncertainty of the hydrogen peaks was generally on the order of ±2% using this measurement time. Also, it was determined through these measurements that there was an ∼17% difference between the hydrogen content of the 'soaked' sample and

  6. Automated carbon-11 radiopharmaceutical production

    International Nuclear Information System (INIS)

    Clark, J.C.; Dowsett, K.

    1992-01-01

    The Hammersmith methylation systems are controlled by a TOSHIBA EX40+ programmable controller with an EX40E expansion unit. Programmable controllers were selected for reliability which at present is very good. (author) 7 figs

  7. Potential use of carbon-11 labeled thymidine (TdR) for studying the effect of therapy on prostatic adenocarcinoma in vivo

    International Nuclear Information System (INIS)

    Conti, P.S.; Kleinert, E.L.; Schma, B.; Herr, H.W.; Whitmore, W.F. Jr.

    1984-01-01

    Alterations in tumor growth, such as those which occur during therapeutic manipulation, may be followed by measuring variations in radiolabeled TdR uptake. In order to study such parameters in vivo using external imaging techniques, the authors have synthesized TdR labeled with cyclotron produced carbon-11, a short-lived (T1/2=20.4 min) positron-emitting radionuclide. The Copenhagen rat bearing the transplantable Dunning R3327G prostatic adenocarcinoma can be used as a model for poorly differentiated carcinoma of the prostate in humans. The tissue distribution of C-14 TdR was studied in untreated tumor rats and in tumor rats receiving a combination of difluoromethyl ornithine and methylglyoxal-bis-guanylhydrazone, effective inhibitors of polyamine biosynthesis. The tissue distribution at 45 min post-injection (5 rats/group) was determined by calculating the relative concentration (RC) of radioactivity in blood and tissue samples (RC=dpm found per gm tissue/dpm injected per gm animal mass). The mean RC in untreated tumor was 2.55 +- 0.46, compared to 0.85 +- 0.12 in treated tumor. Tumor/blood, tumor/muscle and tumor/prostate ratios were 3.07, 7.08, and 6.89 in untreated tumor, and 1.23, 3.04, and 2,93 in treated tumor. The differences in RC for the untreated and treated tumors suggest that external imaging with C-11 TdR may be useful for monitoring the effects of therapy on tumors in vivo

  8. Constant infusion of 15O-labeled water and inhalation of 11C-labeled carbon monoxide for the regional determination of pulmonary water by positron emission tomography

    International Nuclear Information System (INIS)

    Meyer, G.J.; Schober, O.; Hundeshagen, H.

    1983-01-01

    A method was developed for the continuous infusion of 15 O-labeled water which allows the tomographic reconstruction of the total lung water (TLW). Subsequent inhalation of 11 C-labeled carbon-monoxide permits the reconstruction of the blood volume (BV). After normalization of intravascular activities the difference of TLW minus BV yields a quantitative value of regional extravascular lung water (rELW). 15 O-O 2 is converted on-line to 15 O-H 2 O and trapped in a 2 ml buffer reservoir which is fed by a pump with 0.9% NaCl. A precision pump is used to withdraw the labeled H 2 O and infuse it at a rate of 6 ml/min. The radioactivity level of the indusate (ca. 3.7 MBq/sec) is controlled and can be kept constant with a deviation of less than 5% over 40 min. The sterility and apyrogenicity of the system effluent is assured by frequent bacteriological, rabbit and limulus tests. A constant radioactivity level in the lung area is reached after 8-10 min. The infusion is continued for the tomographic reconstruction (Positron Camera System 4200, Cyclotron Corp.) which takes 15 min. A fast change of cyclotron parameters (MC-36, Scanditronix) and automated chemistry procedures allow a single breath administration of 11 C-CO (ca. 40 MBq) 15 min after the end of the 15 O-H 2 O infusion. Blood pool equilibrium is reached after 3-4 min, and the blood volume is reconstructed within 15 min also. Intravascular activites as determined from reconstructed slices in the region of the aortic arch correlate linearly with blood sample activities up to 100 kBq/ml. (orig.) [de

  9. Carbon ion beam triggers both caspase-dependent and caspase-independent pathway of apoptosis in HeLa and status of PARP-1 controls intensity of apoptosis.

    Science.gov (United States)

    Ghorai, Atanu; Sarma, Asitikantha; Bhattacharyya, Nitai P; Ghosh, Utpal

    2015-04-01

    High linear energy transfer (LET) carbon ion beam (CIB) is becoming very promising tool for various cancer treatments and is more efficient than conventional low LET gamma or X-rays to kill malignant or radio-resistant cells, although detailed mechanism of cell death is still unknown. Poly (ADP-ribose) polymerase-1 (PARP-1) is a key player in DNA repair and its inhibitors are well-known as radio-sensitizer for low LET radiation. The objective of our study was to find mechanism(s) of induction of apoptosis by CIB and role of PARP-1 in CIB-induced apoptosis. We observed overall higher apoptosis in PARP-1 knocked down HeLa cells (HsiI) compared with negative control H-vector cells after irradiation with CIB (0-4 Gy). CIB activated both intrinsic and extrinsic pathways of apoptosis via caspase-9 and caspase-8 activation respectively, followed by caspase-3 activation, apoptotic body, nucleosomal ladder formation and sub-G1 accumulation. Apoptosis inducing factor translocation into nucleus in H-vector but not in HsiI cells after CIB irradiation contributed caspase-independent apoptosis. Higher p53 expression was observed in HsiI cells compared with H-vector after exposure with CIB. Notably, we observed about 37 % fall of mitochondrial membrane potential, activation of caspase-9 and caspase-3 and mild activation of caspase-8 without any detectable apoptotic body formation in un-irradiated HsiI cells. We conclude that reduction of PARP-1 expression activates apoptotic signals via intrinsic and extrinsic pathways in un-irradiated cells. CIB irradiation further intensified both intrinsic and extrinsic pathways of apoptosis synergistically along with up-regulation of p53 in HsiI cells resulting overall higher apoptosis in HsiI than H-vector.

  10. Beam line to S155

    CERN Multimedia

    1977-01-01

    The experiment S155 was designed by the Orsay (CSNM-CNRS) Collaboration to observe the properties of exotic light nuclei. It was installed in the PS neutrino tunnel. The photo shows a mass spectrometer (in the background) on line with the PS proton beam which arrives (bottom, right) from the fast extraction FE74. Roger Fergeau stands on the left. The alkaline isotopes produced in the carbon-uranium target heated at 2000°C were swiftly extracted, mass separated, and brought to a detector behind the shielding. Sodium 34 (11 protons and 23 neutrons) was observed and its half-life of only 5 ms was measured. The excited levels 2+ of Magnesium 30 and Magnesium 32 (Sodium descendants) were localised, and the magic number 20 was found to vanish. Thus, the discovery made earlier for Sodium 30 and Sodium 32, with the same apparatus, was confirmed. (See also photo 7706511.)

  11. In-beam γ-ray spectroscopy of N=84 nuclei above Gd and the impact of the (πh11/2νh9/2)1+ attraction on their yrast lines

    International Nuclear Information System (INIS)

    Zhang Chengteng.

    1993-12-01

    In in-beam experiments using the γ-spectrometers Nordball at the Niels Bohr Institute and Osiris at the Hahn-Meitner Institute we populated the four N = 84 isotones 151 Ho, 152 Er, 153 Tm and 154 Yb through compound evaporation reactions induced with medium HI beams of masses ranging from 28 to 56. All observed γ-transitions with intensities above 1% (5% in 154 Yb) of the respective exit channel were placed in the level schemes, with spins established up to 10 MeV (8 MeV for 154 Yb) and parties up to between 5 and 7 MeV. We have found that in these N = 84 nuclei the multi-valence particle configurations πh n 11/2 νf 2 7/2 and πh n 11/2 νf 7/2 h 9/2 are strongly populated in the yrast cascades, and we have observed them up to their maximum spins of 43/2 - in Ho (at 4.8 MeV), 24 + in Er (7.5 MeV), 51/2 - in Tm (6.9 MeV), and only up to 24 + in Yb, 0.5 MeV below the fully aligned 26 + state expected at 9.1 MeV. The πh n νf 2 configuration forms smooth sections of the yrast line, while the more irregular yrast line of the πh n νfh character reflects the strong (νfh)8 + two-body attraction which gives rise to pronounced yrast line dips. We have also carried out full shell model calculations of these yrast lines, which are in excellent agreement with the experimental data. Since we take all dynamic input values, i.e. the two-body matrix elements and the single particle energies, from experiment, the calculations are free of any adjusted parameter. An interesting new result is the systematic identification in the πh n 11/2 νfh configuration of yrast states formed by specific proton couplings, where the strongly attractive (πh 11/2 νh 9/2 )1 + interaction is activated. As a consequence these states drop down to the yrast lines and in energy below the maximum aligned state of the next lower proton seniority. These seniority inverted yrast states were systematically identified in the four N = 84 nuclei, including two such states in 153 T, the first N 84

  12. Realization of an apparatus for the synthesis and detection of carbon 11 labelled fatty acids and of a data acquisition system for the study of the myocardial methabolism of radiopharmaceuticals

    International Nuclear Information System (INIS)

    Fressonnet, G.

    1988-01-01

    This thesis describes the study and the realization of an apparatus to synthesize fatty acids labelled with carbon 11, a radioactive isotope with an half-life of 20.38 minutes. A system of gamma-ray detection with data processing designed for the study of the myocardiac metabolism of radiopharmaceuticals using isolated rat hearts as experimental models. The synthesis of carbon 11 labelled fatty acids required a preliminary study of the manufacture of this isotope at the synchrocyclotron of the I.P.N. (Lyon). The method chosen is the nuclear reaction (d,xn) with naturally occurring boron trioxide as the target. The apparatus was designed so as extract carbon 11 from the target in the form of 11 CO 2 which can then be used in the synthesis of carbon 11 labelled hexadecanoique, heptadecanoic and beta-methyl hexadecanoic acids. The time scale of this synthesis must be compatible with the short half-like of the isotope. In order to study these compounds 'in vivo' on the experimental model of isolated rat hearts, a system of detection, which functions either in a simple gamma mode or in a gamma-gamma coincidence mode, was developed. This apparatus can attain a rate of approximately 50 000 counts/sec. per channel, thus it is possible to obtain information about rapid phases of metabolism with a satisfactory statistical precision. Moreover the spectral analysis of the gamma-ray permits the simultaneous detection of different radioisotopes. Hence it was possible to compare the behaviour of carbon 11 labelled fatty acids with homologous molecules marked with iodine 123. The analysis of the experimental results was achieved witha computer based on an I.B.M. compatible PC-XT. The essential parts of this system are a data-acquisition card for the PC, code for the acquisition and the data processing [fr

  13. Coherent beam-beam effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1992-01-01

    There are two physical pictures that describe the beam-beam interaction in a storage ring collider: The weak-strong and the strong-strong pictures. Both pictures play a role in determining the beam-beam behavior. This review addresses only the strong-strong picture. The corresponding beam dynamical effects are referred to as the coherent beam-beam effects. Some basic knowledge of the weak-strong picture is assumed. To be specific, two beams of opposite charges are considered. (orig.)

  14. Ion-beam technologies

    Energy Technology Data Exchange (ETDEWEB)

    Fenske, G.R. [Argonne National Lab., IL (United States)

    1993-01-01

    This compilation of figures and diagrams reviews processes for depositing diamond/diamond-like carbon films. Processes addressed are chemical vapor deposition (HFCVD, PACVD, etc.), plasma vapor deposition (plasma sputtering, ion beam sputtering, evaporation, etc.), low-energy ion implantation, and hybrid processes (biased sputtering, IBAD, biased HFCVD, etc.). The tribological performance of coatings produced by different means is discussed.

  15. Changes in Rectal Dose Due to Alterations in Beam Angles for Setup Uncertainty and Range Uncertainty in Carbon-Ion Radiotherapy for Prostate Cancer.

    Directory of Open Access Journals (Sweden)

    Yoshiki Kubota

    Full Text Available Carbon-ion radiotherapy of prostate cancer is challenging in patients with metal implants in one or both hips. Problems can be circumvented by using fields at oblique angles. To evaluate the influence of setup and range uncertainties accompanying oblique field angles, we calculated rectal dose changes with oblique orthogonal field angles, using a device with fixed fields at 0° and 90° and a rotating patient couch.Dose distributions were calculated at the standard angles of 0° and 90°, and then at 30° and 60°. Setup uncertainty was simulated with changes from -2 mm to +2 mm for fields in the anterior-posterior, left-right, and cranial-caudal directions, and dose changes from range uncertainty were calculated with a 1 mm water-equivalent path length added to the target isocenter in each angle. The dose distributions regarding the passive irradiation method were calculated using the K2 dose algorithm.The rectal volumes with 0°, 30°, 60°, and 90° field angles at 95% of the prescription dose were 3.4±0.9 cm3, 2.8±1.1 cm3, 2.2±0.8 cm3, and 3.8±1.1 cm3, respectively. As compared with 90° fields, 30° and 60° fields had significant advantages regarding setup uncertainty and significant disadvantages regarding range uncertainty, but were not significantly different from the 90° field setup and range uncertainties.The setup and range uncertainties calculated at 30° and 60° field angles were not associated with a significant change in rectal dose relative to those at 90°.

  16. Interaction of the carbon monoxide-releasing molecule Ru(CO)3Cl(glycinate) (CORM-3) with Salmonella enterica serovar Typhimurium: in situ measurements of carbon monoxide binding by integrating cavity dual-beam spectrophotometry.

    Science.gov (United States)

    Rana, Namrata; McLean, Samantha; Mann, Brian E; Poole, Robert K

    2014-12-01

    Carbon monoxide (CO) is a toxic gas that binds to haems, but also plays critical signalling and cytoprotective roles in mammalian systems; despite problems associated with systemic delivery by inhalation of the gas, it may be employed therapeutically. CO delivered to cells and tissues by CO-releasing molecules (CO-RMs) has beneficial and toxic effects not mimicked by CO gas; CO-RMs are also attractive candidates as novel antimicrobial agents. Salmonella enterica serovar Typhimurium is an enteropathogen causing gastroenteritis in humans. Recent studies have implicated haem oxygenase-1 (HO-1), the protein that catalyses the degradation of haem into biliverdin, free iron and CO, in the host immune response to Salmonella infection. In several studies, CO administration via CO-RMs elicited many of the protective roles of HO-1 induction and so we investigated the effects of a well-characterized water-soluble CO-RM, Ru(CO)3Cl(glycinate) (CORM-3), on Salmonella. CORM-3 exhibits toxic effects at concentrations significantly lower than those reported to cause toxicity to RAW 264.7 macrophages. We demonstrated here, through oxyhaemoglobin assays, that CORM-3 did not release CO spontaneously in phosphate buffer, buffered minimal medium or very rich medium. CORM-3 was, however, accumulated to high levels intracellularly (as shown by inductively coupled plasma MS) and released CO inside cells. Using growing Salmonella cultures without prior concentration, we showed for the first time that sensitive dual-beam integrating cavity absorption spectrophotometry can detect directly the CO released from CORM-3 binding in real-time to haems of the bacterial electron transport chain. The toxic effects of CO-RMs suggested potential applications as adjuvants to antibiotics in antimicrobial therapy. © 2014 The Authors.

  17. Neoplastic transformation induced by carbon ions.

    Science.gov (United States)

    Bettega, Daniela; Calzolari, Paola; Hessel, Petra; Stucchi, Claudio G; Weyrather, Wilma K

    2009-03-01

    The objective of this experiment was to compare the oncogenic potential of carbon ion beams and conventional photon beams for use in radiotherapy. The HeLa X human skin fibroblast cell line CGL1 was irradiated with carbon ions of three different energies (270, 100, and 11.4 MeV/u). Inactivation and transformation data were compared with those for 15 MeV photons. Inactivation and transformation frequencies for the 270 MeV/u carbon ions were similar to those for 15-MeV photons. The maximal relative biologic effectiveness (RBE(alpha)) values for 100MeV/u and 11.4 MeV/u carbon ions, respectively, were as follows: inactivation, 1.6 +/- 0.2 and 6.7 +/- 0.7; and transformation per surviving cell, 2.5 +/- 0.6 and 12 +/- 3. The curve for dose-transformation per cell at risk exhibited a maximum that was shifted toward lower doses at lower energies. Transformation induction per cell at risk for carbon ions in the entrance channel was comparable to that for photons, whereas for the lower energies, 100 MeV/u and 11 MeV/u, which are representative of the energies delivered to the tumor margins and volume, respectively, the probability of transformation in a single cell was greater than it was for photons. In addition, at isoeffective doses with respect to cell killing, the 11.4-MeV/u beam was more oncogenic than were photons.

  18. Correlation of stable elevations in striatal mu-opioid receptor availability in detoxified alcoholic patients with alcohol craving: a positron emission tomography study using carbon 11-labeled carfentanil.

    Science.gov (United States)

    Heinz, Andreas; Reimold, Matthias; Wrase, Jana; Hermann, Derik; Croissant, Bernhard; Mundle, Götz; Dohmen, Bernhard M; Braus, Dieter F; Braus, Dieter H; Schumann, Gunter; Machulla, Hans-Jürgen; Bares, Roland; Mann, Karl

    2005-01-01

    The pleasant effects of food and alcohol intake are partially mediated by mu-opiate receptors in the ventral striatum, a central area of the brain reward system. Blockade of mu-opiate receptors with naltrexone reduces the relapse risk among some but not all alcoholic individuals. To test the hypothesis that alcohol craving is pronounced among alcoholic individuals with a high availability of mu-opiate receptors in the brain reward system. Patients and comparison sample. The availability of central mu-opiate receptors was measured in vivo with positron emission tomography (PET) and the radioligand carbon 11-labeled carfentanil in the ventral striatum and compared with the severity of alcohol craving as assessed by the Obsessive Compulsive Drinking Scale (OCDS). Hospitalized care. Volunteer sample of 25 male alcohol-dependent inpatients assessed after detoxification of whom 12 underwent PET again 5 weeks later. Control group of 10 healthy men. After 1 to 3 weeks of abstinence, the availability of mu-opiate receptors in the ventral striatum, including the nucleus accumbens, was significantly elevated in alcoholic patients compared with healthy controls and remained elevated when 12 alcoholic patients had these levels measured 5 weeks later (P<.05 corrected for multiple testing). Higher availability of mu-opiate receptors in this brain area correlated significantly with the intensity of alcohol craving as assessed by the OCDS. Abstinent alcoholic patients displayed an increase in mu-opiate receptors in the ventral striatum, including the nucleus accumbens, which correlated with the severity of alcohol craving. These findings point to a neuronal correlate of alcohol urges.

  19. Evaluation of 11 terrestrial carbon-nitrogen cycle models against observations from two temperate Free-Air CO2 Enrichment studies.

    Science.gov (United States)

    Zaehle, Sönke; Medlyn, Belinda E; De Kauwe, Martin G; Walker, Anthony P; Dietze, Michael C; Hickler, Thomas; Luo, Yiqi; Wang, Ying-Ping; El-Masri, Bassil; Thornton, Peter; Jain, Atul; Wang, Shusen; Warlind, David; Weng, Ensheng; Parton, William; Iversen, Colleen M; Gallet-Budynek, Anne; McCarthy, Heather; Finzi, Adrien; Hanson, Paul J; Prentice, I Colin; Oren, Ram; Norby, Richard J

    2014-05-01

    We analysed the responses of 11 ecosystem models to elevated atmospheric [CO2 ] (eCO2 ) at two temperate forest ecosystems (Duke and Oak Ridge National Laboratory (ORNL) Free-Air CO2 Enrichment (FACE) experiments) to test alternative representations of carbon (C)-nitrogen (N) cycle processes. We decomposed the model responses into component processes affecting the response to eCO2 and confronted these with observations from the FACE experiments. Most of the models reproduced the observed initial enhancement of net primary production (NPP) at both sites, but none was able to simulate both the sustained 10-yr enhancement at Duke and the declining response at ORNL: models generally showed signs of progressive N limitation as a result of lower than observed plant N uptake. Nonetheless, many models showed qualitative agreement with observed component processes. The results suggest that improved representation of above-ground-below-ground interactions and better constraints on plant stoichiometry are important for a predictive understanding of eCO2 effects. Improved accuracy of soil organic matter inventories is pivotal to reduce uncertainty in the observed C-N budgets. The two FACE experiments are insufficient to fully constrain terrestrial responses to eCO2 , given the complexity of factors leading to the observed diverging trends, and the consequential inability of the models to explain these trends. Nevertheless, the ecosystem models were able to capture important features of the experiments, lending some support to their projections. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  20. Secondary beams at GANIL

    International Nuclear Information System (INIS)

    Doubre, H.

    1992-01-01

    GANIL, a user's facility since 1983, can deliver a broad spectrum of heavy-ion beams, from He to U, to well-equipped experimental areas. Their very large intensities are to be exploited to produce secondary beams, either using the fragmentation method (beams at energy per nucleon larger than 30 MeV/u), or the ISOL method. With the latter one, these ions have to be re-accelerated. The project of a cyclotron as a post-accelerator is described. (author) 11 refs.; 7 figs.; 3 tabs

  1. Crossed-beam reaction of carbon atoms with hydrocarbon molecules. IV. Chemical dynamics of methylpropargyl radical formation, C4H5, from reaction of C(3Pj) with propylene, C3H6 (X1A)

    International Nuclear Information System (INIS)

    Kaiser, R.I.; Stranges, D.; Bevsek, H.M.; Lee, Y.T.; Suits, A.G.

    1997-01-01

    The reaction between ground state carbon atoms and propylene, C 3 H 6 , was studied at average collision energies of 23.3 and 45.0 kJmol -1 using the crossed molecular beam technique. Product angular distributions and time-of-flight spectra of C 4 H 5 at m/e=53 were recorded. Forward-convolution fitting of the data yields a maximum energy release as well as angular distributions consistent with the formation of methylpropargyl radicals. Reaction dynamics inferred from the experimental results suggest that the reaction proceeds on the lowest 3 A surface via an initial addition of the carbon atom to the π-orbital to form a triplet methylcyclopropylidene collision complex followed by ring opening to triplet 1,2-butadiene. Within 0.3 endash 0.6 ps, 1,2-butadiene decomposes through carbon endash hydrogen bond rupture to atomic hydrogen and methylpropargyl radicals. The explicit identification of C 4 H 5 under single collision conditions represents a further example of a carbon endash hydrogen exchange in reactions of ground state carbon with unsaturated hydrocarbons. This versatile machine represents an alternative pathway to build up unsaturated hydrocarbon chains in combustion processes, chemical vapor deposition, and in the interstellar medium. copyright 1997 American Institute of Physics

  2. Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Ronald H. Brown Repeat Hydrography Cruise in the Atlantic Ocean: CLIVAR CO2 Section A16S_2005 (11 January - 24 February, 2005)

    Energy Technology Data Exchange (ETDEWEB)

    Kozyr, Alex [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Carbon Dioxide Information Analysis Center

    2006-08-30

    This report presents methods, and analytical and quality control procedures for salinity, oxygen, nutrient, inorganic carbon, organic carbon, chlorofluorocarbon (CFC), and bomb 14C system parameters performed during the A16S_2005 cruise, which took place from January 11 to February 24, 2005, aboard research vessel (R/V) Ronald H. Brown under the auspices of the National Oceanic and Atmospheric Administration (NOAA). The R/V Ronald H. Brown departed Punta Arenas, Chile, on January 11, 2005, and ended its cruise in Fortaleza, Brazil, on February 24, 2005. The research conducted was one of a series of repeat hydrography sections jointly funded by NOAA and the National Science Foundation as part of the CLIVAR/CO2/repeat hydrography/tracer program. Samples were taken from 36 depths at 121 stations. The data presented in this report include the analyses of water samples for total inorganic carbon (TCO2), fugacity of CO2 (fCO2), total alkalinity (TALK), pH, dissolved organic carbon (DOC), CFC, 14C, hydrographic, and other chemical measurements. The R/V Ronald H. Brown A16S_2005 data set is available free of charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center (CDIAC). The NDP consists of the oceanographic data files and this printed documentation, which describes the procedures and methods used to obtain the data.

  3. Formation of tin-tin oxide core–shell nanoparticles in the composite SnO{sub 2−x}/nitrogen-doped carbon nanotubes by pulsed ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Korusenko, P.M., E-mail: korusenko@obisp.oscsbras.ru [Omsk Scientific Center, Siberian Branch of the Russian Academy of Sciences, Karl Marx avenue 15, 644040 Omsk (Russian Federation); Nesov, S.N.; Bolotov, V.V.; Povoroznyuk, S.N. [Omsk Scientific Center, Siberian Branch of the Russian Academy of Sciences, Karl Marx avenue 15, 644040 Omsk (Russian Federation); Pushkarev, A.I. [National Research Tomsk Polytechnic University, Lenin Ave. 2a, 634028 Tomsk (Russian Federation); Ivlev, K.E. [Omsk Scientific Center, Siberian Branch of the Russian Academy of Sciences, Karl Marx avenue 15, 644040 Omsk (Russian Federation); Smirnov, D.A. [St. Petersburg State University, Lieutenant Shmidt Emb. 11, 198504 St. Petersburg (Russian Federation); Institute of Solid State Physics, Dresden University of Technology, D-01069 Dresden (Germany)

    2017-03-01

    Highlights: • Original method the formation of core–shell structures by pulsed ion beam is proposed. • The composite SnO{sub 2−x}/N-MWCNTs was irradiated by pulsed ion beam. • Morphology and electronic structure of the irradiated composite were characterized. • The formation of Sn−SnO{sub x} core–shell nanoparticles after irradiation was observed. - Abstract: The complex methods of transmission electron microscopy, energy dispersive X-ray analysis, and X-ray photoelectron spectroscopy were used to investigate the changes in the morphology, phase composition, and electronic structure of the composite SnO{sub 2−x}/nitrogen-doped multiwalled carbon nanotubes (SnO{sub 2−x}/N-MWCNTs) irradiated with the pulsed ion beam of nanosecond duration. The irradiation of the composite SnO{sub 2−x}/N-MWCNTs leads to the formation of nanoparticles with the core–shell structure on the surface of CNTs with a sharp interfacial boundary. It has been established that the “core” is a metal tin (Sn{sup 0}) with a typical size of 5–35 nm, and the “shell” is a thin amorphous layer (2–6 nm) consisting of nonstoichiometric tin oxide with a low oxygen content. The “core–shell” structure Sn−SnO{sub x} is formed due to the process of heating and evaporation of SnO{sub 2−x} under the effect of the ion beam, followed by vapor deposition on the surface of carbon nanotubes.

  4. Development of a NiO target for the production of {sup 11}C at ISAC/TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Bricault, Pierre G.; Ames, Friedhelm; Dombsky, Marik; Kunz, Peter; Lassen, Jens; Mjøs, Anders; Wong, John

    2016-01-01

    High intensity {sup 11}C beams are necessary for the investigation of the formation of {sup 12}C via the nuclear reaction {sup 11}C(p, γ){sup 12}N → {sup 12}C + e{sup +} + ν. The production of intense carbon beams on-line is quite challenging due to the thermodynamic properties and chemical reactivity of carbon at high temperatures. A previous attempt, using a medical isotope cyclotron production method in batch mode, was not conclusive. The intensity obtained was at least one order of magnitude too low for a direct proton capture experiment using the DRAGON facility at ISAC/TRIUMF. Producing a {sup 11}C beams using the ISOL method requires a target capable of efficiently releasing the carbon isotopes. NiO has been selected as a target material because most of the nickel carbides are not stable at high temperature. The development of carbon beams using a composite NiO/Ni target on-line is described.

  5. Synthesis and carbon-11-labeling of p-MeO-SSR180575, a novel indoleacetamide-based candidate for PET imaging of the peripheral benzodiazepine receptor (TSPO 18 kDa)

    International Nuclear Information System (INIS)

    Damont, A.L.; Le Helleix, St.; Kuhnast, B.; Boisgard, R.; Tavitian, B.; Dolle, F.; Marguet, F.; Puech, F.

    2011-01-01

    Complete text of publication follows: Objectives: The 3-iso-quinolinecarboxamide [ 11 C]PK11195, despite its low brain uptake and high level of nonspecific binding, is still the most widely used PET-radioligand for the in vivo imaging of the peripheral benzodiazepine receptor (PBR or TSPO 18 kDa). Several new PBR radioligands are currently developed to replace [ 11 C]PK11195 [1], e.g the pyrazolo[1, 5-a]pyrimidine-acetamides [ 11 C]DPA-713 and [ 18 F]DPA-714, the imidazo[1, 2-a]pyridine-acetamides [ 11 C]CLINME and [ 18 F]PBR111 and the N-benzyl-N-(2-phenoxy-aryl)- acetamides [ 11 C]PBR28 and [ 18 F]FEDAA1106. Another attractive newly identified chemical class of structures are the indole-acetamides and notably compounds derived from the lead compound SSR180575 [2]. Herein are reported the synthesis and the labelling with the positron-emitter carbon-11 (half-life: 20.38 min) of a novel derivative of SSR180575, bearing a para methoxy function on its phenyl ring. Methods: p-MeO-SSR180575 (1) was synthesized from commercially available 4-chloro-2-nitrotoluene in 10 steps. O-demethylation, performed with a boron tribromide solution in dichloromethane at low temperature, afforded the free phenol derivative 2. Carbon-11 labeling of p-MeO-SSR180575 (1) was performed using a TRACERLab FX-C Pro synthesizer (GEMS) and comprised (1) trapping of [ 11 C]MeOTf at -10 C in acetone (0.3 mL) containing the nor-derivative 2 (O-demethylated, 0.6-0.9 mg) and aq. 3N NaOH (8 μL); (2) heating at 110 C for 2 min; (3) concentration to dryness and taking up the residue in 1.0 mL of the HPLC mobile phase; (4) purification using semi-preparative reversed-phase HPLC (Waters Symmetry R C-18 - eluent: CH 3 CN / H 2 O / TFA: 50 / 50 / 0.1 (v:v:v) - flow rate: 5 mL/min - detection at 254 nm) and (5) SepPak Plus R C-18-based formulation for i.v. injection approach was the pyridazine ring formation reaction that proceeded partially: the maximum conversion of the intermediate diester-indole reacting

  6. Synthesis and carbon-11-labeling of p-MeO-SSR180575, a novel indoleacetamide-based candidate for PET imaging of the peripheral benzodiazepine receptor (TSPO 18 kDa)

    International Nuclear Information System (INIS)

    Damont, A.; Le Helleix, St.; Kuhnast, B.; Boisgard, R.; Tavitian, B.; Dolle, F.; Marguet, F.; Puech, F.

    2011-01-01

    Complete text of publication follows: Objectives: The 3-iso-quinolinecarboxamide [ 11 C]PK11195, despite its low brain uptake and high level of nonspecific binding, is still the most widely used PET-radioligand for the in vivo imaging of the peripheral benzodiazepine receptor (PBR or TSPO 18 kDa). Several new PBR radioligands are currently developed to replace [ 11 C]PK11195, e.g the pyrazolo[1, 5-a]pyrimidine-acetamides [ 11 C]DPA-713 and [ 18 F]DPA-714, the imidazo[1, 2-a]pyridine-acetamides [ 11 C]CLINME and [ 18 F]PBR111 and the N-benzyl-N-(2-phenoxy-aryl)- acetamides [ 11 C]PBR28 and [ 18 F]FEDAA1106. Another attractive newly identified chemical class of structures are the indole-acetamides and notably compounds derived from the lead compound SSR180575. Herein are reported the synthesis and the labelling with the positron-emitter carbon-11 (half-life: 20.38 min) of a novel derivative of SSR180575, bearing a para methoxy function on its phenyl ring. Methods: p-MeO-SSR180575 (1) was synthesized from commercially available 4-chloro-2-nitrotoluene in 10 steps. O-demethylation, performed with a boron tribromide solution in dichloromethane at low temperature, afforded the free phenol derivative 2. Carbon-11 labeling of p-MeO-SSR180575 (1) was performed using a TRACERLab FX-C Pro synthesizer (GEMS) and comprised (1) trapping of [ 11 C]MeOTf at -10 C in acetone (0.3 mL) containing the nor-derivative 2 (O-demethylated, 0.6-0.9 mg) and aq. 3N NaOH (8 μL); (2) heating at 110 C for 2 min; (3) concentration to dryness and taking up the residue in 1.0 mL of the HPLC mobile phase; (4) purification using semi-preparative reversed-phase HPLC (Waters Symmetry C-18 - eluent: CH 3 CN / H 2 O / TFA: 50 / 50 / 0.1 (v:v:v) - flow rate: 5 mL/min - detection at 254 nm) and (5) SepPak R Plus C-18-based formulation for i.v. injection. Results: p-MeO-SSR180575 (1) was obtained in 10% overall yield. The tricky and low-yielding step in our approach was the pyridazine ring formation

  7. Influence of nanosized carbon forms on the properties and susceptibility of energy-saturated cobalt salt to a pulsed electron beam

    Science.gov (United States)

    Savenkov, G. G.; Morozov, V. A.; Ilyushin, M. A.; Os'kin, I. A.; Bragin, V. A.; Kozlov, A. S.

    2017-11-01

    The influence of fullerenes and detonation nanodiamonds on the initiation of complex cobalt perchlorate by a nanosecond pulsed electron beam has been studied. The results on the thermal compatibility of experimental compositions in nonisothermal conditions have been presented.

  8. Treatment of industrial effluents using electron beam accelerator and adsorption with activated carbon. A comparative study; Tratamento de efluentes industriais utilizando a radiacao ionizante de acelerador industrial de eletrons e por adsorcao com carvao ativado. Estudo comparativo

    Energy Technology Data Exchange (ETDEWEB)

    Las Casas, Alexandre

    2004-07-01

    Several methods are used In the pollutant removal from Industrial and domestic wastewater. However when the degradation of toxic organic pollutants, mainly the recalcitrant is objectified, the conventional treatments usually do not meet the desirable performance in the elimination or decrease the impact when the effluent are released to the environment what takes to the research of alternative methods that seek the improvement of the efficiency of the wastewater treatment systems jointly employees or separately. This work presents a study of degradation/removal of pollutants organic compounds comparing two methods using radiation from industrial electron beam and granular activated carbon (GAC). The removal efficiency of the pollutants was evaluated and it was verified that the efficiency of adsorption with activated carbon is similar to the radiation method. The obtained results allowed to evaluated the relative costs of these methods. (author)

  9. Beam loading

    OpenAIRE

    Boussard, Daniel

    1987-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superco...

  10. Molecular beams

    International Nuclear Information System (INIS)

    Pendelbury, J.M.; Smith, K.F.

    1987-01-01

    Studies with directed collision-free beams of particles continue to play an important role in the development of modern physics and chemistry. The deflections suffered by such beams as they pass through electric and magnetic fields or laser radiation provide some of the most direct information about the individual constituents of the beam; the scattering observed when two beams intersect yields important data about the intermolecular forces responsible for the scattering. (author)

  11. Radiolytic synthesis of carbon-supported PtRu nanoparticles using high-energy electron beam: effect of pH control on the PtRu mixing state and the methanol oxidation activity

    International Nuclear Information System (INIS)

    Ohkubo, Yuji; Kageyama, Satoru; Seino, Satoshi; Nakagawa, Takashi; Kugai, Junichiro; Nitani, Hiroaki; Ueno, Koji; Yamamoto, Takao A.

    2013-01-01

    Electrode catalysts composed of carbon-supported PtRu nanoparticles (PtRu/C) for use as a direct methanol fuel cell anode were synthesized by the reduction of precursor ions in an aqueous solution via irradiation with a high-energy electron beam. The effect of pH control in the precursor solution on the PtRu mixing state and the methanol oxidation activity was studied in order to enhance the catalytic activity for methanol oxidation. The PtRu/C structures were characterized by transmission electron microscopy, inductively coupled plasma atomic emission spectrometry, X-ray fluorescence spectrometry, and X-ray diffraction and X-ray absorption fine structure techniques. The methanol oxidation activity was evaluated by linear sweep voltammetry. The initial pH of the precursor solution has little influence on the average grain size for the metal particles (approximately 3.5 nm) on the carbon particle supports, but the dispersibility of the metal particles, PtRu mixing state, and methanol oxidation activity differed. The maintenance of a low pH in the precursor solution gave the best dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles, whereas, a high pH gave the best PtRu mixing state and the highest oxidation current although a low dispersibility of the PtRu